Protein kinase C isozymes, novel phorbol ester receptors and cancer chemotherapy.

LENUS (Irish Health Repository)

Barry, O P

2012-02-03

Recent years have seen extensive growth in the understanding of the role(s) of the various PKC isozymes and novel receptors for the phorbol ester tumor promoters. The PKC family of serine-threonine kinases is an important regulator of signaling cascades that control cell proliferation and death, and therefore represent targets for cancer therapy. While past interests have focused on PKC-selective inhibitors, more recently, intensive research has been underway for selective activators and inhibitors for each individual PKC isozyme. In the past few years a large number of PKC activators and inhibitors with potential as anticancer agents have been developed. A number of these compounds are already in Phase II clinical testing. As a new generation of cancer chemotherapeutic agents are designed, developed and put through a series of rigorous clinical trials, we can anticipate achieving exquisite control over PKC-mediated regulatory pathways, leading ultimately to a greater understanding of different cancers.

Effects of phorbol ester on mitogen-activated protein kinase kinase activity in wild-type and phorbol ester-resistant EL4 thymoma cells.

Science.gov (United States)

Gause, K C; Homma, M K; Licciardi, K A; Seger, R; Ahn, N G; Peterson, M J; Krebs, E G; Meier, K E

1993-08-05

Phorbol ester-sensitive and -resistant EL4 thymoma cell lines differ in their ability to activate mitogen-activated protein kinase (MAPK) in response to phorbol ester. Treatment of wild-type EL4 cells with phorbol ester results in the rapid activations of MAPK and pp90rsk kinase, a substrate for MAPK, while neither kinase is activated in response to phorbol ester in variant EL4 cells. This study examines the activation of MAPK kinase (MAPKK), an activator of MAPK, in wild-type and variant EL4 cells. Phosphorylation of a 40-kDa substrate, identified as MAPK, was observed following in vitro phosphorylation reactions using cytosolic extracts or Mono Q column fractions prepared from phorbol ester-treated wild-type EL4 cells. MAPKK activity coeluted with a portion of the inactive MAPK upon Mono Q anion-exchange chromatography, permitting detection of the MAPKK activity in fractions containing both kinases. This MAPKK activity was present in phorbol ester-treated wild-type cells, but not in phorbol ester-treated variant cells or in untreated wild-type or variant cells. The MAPKK from wild-type cells was able to activate MAPK prepared from either wild-type or variant cells. MAPKK activity could be stimulated in both wildtype and variant EL4 cells in response to treatment of cells with okadaic acid. These results indicate that the failure of variant EL4 cells to activate MAP kinase in response to phorbol ester is due to a failure to activate MAPKK. Therefore, the step that confers phorbol ester resistance to variant EL4 cells lies between the activation of protein kinase C and the activation of MAPKK.

Composing a Tumor Specific Bacterial Promoter.

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Igor V Deyneko

Full Text Available Systemically applied Salmonella enterica spp. have been shown to invade and colonize neoplastic tissues where it retards the growth of many tumors. This offers the possibility to use the bacteria as a vehicle for the tumor specific delivery of therapeutic molecules. Specificity of such delivery is solely depending on promoter sequences that control the production of a target molecule. We have established the functional structure of bacterial promoters that are transcriptionally active exclusively in tumor tissues after systemic application. We observed that the specific transcriptional activation is accomplished by a combination of a weak basal promoter and a strong FNR binding site. This represents a minimal set of control elements required for such activation. In natural promoters, additional DNA remodeling elements are found that alter the level of transcription quantitatively. Inefficiency of the basal promoter ensures the absence of transcription outside tumors. As a proof of concept, we compiled an artificial promoter sequence from individual motifs representing FNR and basal promoter and showed specific activation in a tumor microenvironment. Our results open possibilities for the generation of promoters with an adjusted level of expression of target proteins in particular for applications in bacterial tumor therapy.

Molecular mechanisms of drug resistance and tumor promotion involving mammalian ribonucleotide reductase

Energy Technology Data Exchange (ETDEWEB)

Choy, B.B.K.

1991-01-01

Mammalian ribonucleotide reductase is a highly regulated, rate-limiting activity responsible for converting ribonucleoside diphosphates to the deoxyribonucleotide precursors of DNA. The enzyme consists of two nonidentical proteins called M1 and M2, both of which are required for activity. Hydroxyurea is an antitumor agent which inhibits ribonucleotide reductase by interacting with the M2 component specifically at a unique tyrosyl free radical. Studies were conducted on a series of drug resistant mouse cell lines, selected by a step-wise procedure for increasing levels of resistance to the cytotoxic effects of hydroxyurea. Each successive drug selection step leading to the isolation of highly resistant cells was accompanied by stable elevations in cellular resistance and ribonucleotide reductase activity. The drug resistant cell lines exhibited gene amplification of the M2 gene, elevated M2 mRNA, and M2 protein. In addition to M2 gene amplification, posttranscriptional modulation also occurred during the drug selection. Studies of the biosynthesis rates with exogenously added iron suggest a role for iron in regulating the level of M2 protein when cells are cultured in the presence of hydroxyurea. The hydroxyurea-inactivated ribonucleotide reductase protein M2 has a destabilized iron centre, which readily releases iron. Altered expression of ferritin appears to be required for the development of hydroxyurea resistance in nammalian cells. The results show an interesting relationship between the expressions of ribonucleotide reductase and ferritin. The phorbol ester tumor promoter, TPA, is also able to alter the expression of M2. TPA was able to induce M2 mRNA levels transiently up to 18-fold within 1/2 hour. This rapid and large elevation of ribonucleotide reductase suggests that the enzyme may play a role in tumor promotion. Studies of the M2 promoter region were undertaken to better understand the mechanism of TPA induction of M2.

Phorbol esters alter adenylate cyclase responses to vasoactive intestinal peptide and forskolin in the GH cell line

Energy Technology Data Exchange (ETDEWEB)

Summers, S.; Florio, T.; Cronin, M.

1986-05-01

Activation of protein kinase C with phorbol ester modifies cyclic AMP production in several anterior pituitary cell systems. In the GH cell line from a rat pituitary tumor, exposure to phorbol 12-myristate 13-acetate (PMA: 100 nM) for 30 minutes significantly reduces vasoactive intestinal peptide (VIP: 100 nM) stimulated adenylate cyclase (AC) activity in subsequent membrane preparations to 62 + 4% of control (n = 6 independent studies). In contrast, these same membrane preparations respond to forskolin (1 ..mu..M) with significantly more activity, 130 +/- 6% of controls (n = 6 independent studies). Finally, phorbol ester does not block an inhibitory hormone input into the AC system; somatostatin (100 nM) reduction of VIP-stimulated AC activity is not significantly different in membrane preparations from PMA treated and control cells (n = 3 independent studies). These other findings lead the authors to propose that protein kinase C can modify several sites in the AC complex in anterior pituitary cells.

Biological responsiveness to the phorbol esters and specific binding of [3H]phorbol 12,13-dibutyrate in the nematode Caenorhabditis elegans, a manipulable genetic system

International Nuclear Information System (INIS)

Lew, K.K.; Chritton, S.; Blumberg, P.M.

1982-01-01

Because of its suitability for genetic studies, the nematode Caenorhabditis elegans was examined for its responsiveness to the phorbol esters. Phorbol 12-myristate 13-acetate had three effects. It inhibited the increase in animal size during growth; it decreased the yield of progeny; and it caused uncoordinated movement of the adult. The effects on nematode size, progeny yield, and movement were quantitated. Concentrations of phorbol 12-myristate 13-acetate yielding half-maximal responses were 440, 460, and 170 nM, respectively. As was expected from the biological responsiveness of the nematodes, specific, saturable binding of phorbol ester to nematode extracts was found. [ 3 H]phorbol 12,13-dibutyrate bound with a dissociation constant of 26.8 +/- 3.9 nM. At saturation, 5.7 +/- 1.4 pmole/mg protein was bound

Sonic Hedgehog Signaling Promotes Tumor Growth

National Research Council Canada - National Science Library

Bushman, Wade

2007-01-01

... of the DOD New Investigator award indicate that Shh signaling promotes tumor growth. This proposal addresses the hypothesis that Sonic hedgehog signaling promotes tumor growth by activating stromal cell gene expression...

Lymphocyte adhesion to endothelial cell (EC) is stimulated by phorbol esters

International Nuclear Information System (INIS)

Haskard, D.; Cavender, D.; Ziff, M.

1986-01-01

The effect of phorbol esters on T cell adhesion to EC has been studied. The phorbol esters 12-0-tetradecanoyl-phorbol-13-acetate and 4-beta-phorbol-12-13-dibutyrate, but not the biologically inert 4-0-methyl-phorbol-12-13-didecanoate strongly increased the binding of 51 Cr-labeled T cells to human umbilical vein EC monolayers in microtiter wells. Increase in binding was observed at 0.3 ng/ml with maximal enhancement at 50 ng/ml. Both unstimulated and phorbol ester activated T cells displayed a substantially greater binding affinity for EC than for fibroblasts or plastic. Binding enhancement occurred within one minute, with maximal increase after 15 min. Preincubation studies showed that binding enhancement was entirely attributable to an effect on T cells, with no action on EC. Additive binding enhancement was seen when phorbol esters and reagents that increase adhesion by actions on EC (LPS, IL-1 and IFN-γ) were used together. Increase in adhesion of activated T lymphocytes to EC may explain the greater emigration of activated T cells than small resting T cells into inflammatory foci in vivo. The rapid onset of the phorbol effect suggests that this may be an important mechanism for immediate localization of circulating T cells in the cellular immune response, activated, perhaps, at the endothelial blood-tissue interface

Integrated modulation of phorbol ester-induced Raf activation in EL4 lymphoma cells.

Science.gov (United States)

Han, Shujie; Meier, Kathryn E

2009-05-01

The EL4 murine lymphoma cell line exists in variant phenotypes that differ with respect to responses to the tumor promoter phorbol 12-myristate 13-acetate (PMA1). Previous work showed that "PMA-sensitive" cells, characterized by a high magnitude of PMA-induced Erk activation, express RasGRP, a phorbol ester receptor that directly activates Ras. In "PMA-resistant" and "intermediate" EL4 cell lines, PMA induces Erk activation to lesser extents, but with a greater response in intermediate cells. In the current study, these cell lines were used to examine mechanisms of Raf-1 modulation. Phospho-specific antibodies were utilized to define patterns and kinetics of Raf-1 phosphorylation on several sites. Further studies showed that Akt is constitutively activated to a greater extent in PMA-resistant than in PMA-sensitive cells, and also to a greater extent in resistant than intermediate cells. Akt negatively regulates Raf-1 activation (Ser259), partially explaining the difference between resistant and intermediate cells. Erk activation exerts negative feedback on Raf-1 (Ser289/296/301), thus resulting in earlier termination of the signal in cells with a higher level of Erk activation. RKIP, a Raf inhibitory protein, is expressed at higher levels in resistant cells than in sensitive or intermediate cells. Knockdown of RKIP increases Erk activation and also negative feedback. In conclusion, this study delineates Raf-1 phosphorylation events occurring in response to PMA in cell lines with different extents of Erk activation. Variations in the levels of expression and activation of multiple signaling proteins work in an integrated fashion to modulate the extent and duration of Erk activation.

THE TUMOR MACROENVIRONMENT: CANCER-PROMOTING NETWORKS BEYOND TUMOR BEDS

OpenAIRE

Rutkowski, Melanie R.; Svoronos, Nikolaos; Puchalt, Alfredo Perales; Conejo-Garcia, Jose R.

2015-01-01

During tumor progression, alterations within the systemic tumor environment, or macroenvironment, result in the promotion of tumor growth, tumor invasion to distal organs, and eventual metastatic disease. Distally produced hormones, commensal microbiota residing within mucosal surfaces, and myeloid cells and even the bone marrow impact the systemic immune system, tumor growth, and metastatic spread. Understanding the reciprocal interactions between the cells and soluble factors within the mac...

Tumor-Infiltrating Immune Cells Promoting Tumor Invasion and Metastasis: Existing Theories

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Yan-gao Man, Alexander Stojadinovic, Jeffrey Mason, Itzhak Avital, Anton Bilchik, Bjoern Bruecher, Mladjan Protic, Aviram Nissan, Mina Izadjoo, Xichen Zhang, Anahid Jewett

2013-01-01

Full Text Available It is a commonly held belief that infiltration of immune cells into tumor tissues and direct physical contact between tumor cells and infiltrated immune cells is associated with physical destructions of the tumor cells, reduction of the tumor burden, and improved clinical prognosis. An increasing number of studies, however, have suggested that aberrant infiltration of immune cells into tumor or normal tissues may promote tumor progression, invasion, and metastasis. Neither the primary reason for these contradictory observations, nor the mechanism for the reported diverse impact of tumor-infiltrating immune cells has been elucidated, making it difficult to judge the clinical implications of infiltration of immune cells within tumor tissues. This mini-review presents several existing hypotheses and models that favor the promoting impact of tumor-infiltrating immune cells on tumor invasion and metastasis, and also analyzes their strength and weakness.

Plasma application for detoxification of Jatropha phorbol esters

International Nuclear Information System (INIS)

Kongmany, S; Matsuura, H; Furuta, M; Okuda, S; Imamura, K; Maeda, Y

2013-01-01

Atmospheric pressure non-thermal dielectric barrier discharge (DBD) plasma generated by helium gas at high voltage and input power of about 50 W was first applied to detoxification of Jatropha curcas phorbol esters (J. PEs) as well as standard phorbol ester (4β-12-O-tetradecanoyl phorbol-13-acetate, TPA) in water and methanol. Plasma irradiation on the solution sample was conducted for 15 min. In aqueous solution, only 16% of TPA was degraded and complete degradation of J. PEs was observed. On the contrary, complete degradation of both TPA and J. PEs in methanol was achieved by the same plasma irradiation condition. Hydroxyl radical (.OH) generated by plasma irradiation of the solution is expected as the main radical inducing the degradation of PEs.

Ionizing radiation in tumor promotion and progression

International Nuclear Information System (INIS)

Mitchel, R.E.J.

1990-08-01

Chronic exposure to beta radiation has been tested as a tumor promoting or progressing agent. The dorsal skins of groups of 25 female SENCAR mice were chemically initiated with a single exposure to DMBA, and chronic exposure to strontium-90/yttrium-90 beta radiation was tested as a stage 1, stage 2 or complete skin tumor promoter. Exposure of initiated mice to 0.5 gray twice a week for 13 weeks produced no papillomas, indicating no action as a complete promoter. Another similar group of animals was chemically promoted through stage 1 (with TPA) followed by 0.5 gray of beta radiation twice a week for 13 weeks. Again no papillomas developed indicating no action of chronic radiation as a stage 2 tumor promoter. The same radiation exposure protocol in another DMBA initiated group receiving both stage 1 and 2 chemical promotion resulted in a decrease in papilloma frequency, compared to the control group receiving no beta irradiation, indicating a tumor preventing effect of radiation at stage 2 promotion, probably by killing initiated cells. Chronic beta radiation was tested three different ways as a stage 1 tumor promoter. When compared to the appropriate control, beta radiation given after initiation as a stage 1 promoter (0.5 gray twice a week for 13 weeks), after initiation and along with a known stage 1 chemical promoter (1.0 gray twice a week for 2 weeks), or prior to initiation as a stage 1 promoter (0.5 gray twice a week for 4 weeks), each time showed a weak (∼ 15% stimulation) but statistically significant (p<0.01) ability to act as a stage 1 promoter. When tested as a tumor progressing agent delivered to pre-existing papillomas, beta radiation (0.5 gray twice a week for 13 weeks) increased carcinoma frequency from 0.52 to 0.68 carcinoma/animal, but this increase was not statistically significant at the 95% confidence level. We conclude that in the addition to the known initiating, progressing and complete carcinogenic action of acute exposures to ionizing

The Tumor Macroenvironment: Cancer-Promoting Networks Beyond Tumor Beds.

Science.gov (United States)

Rutkowski, Melanie R; Svoronos, Nikolaos; Perales-Puchalt, Alfredo; Conejo-Garcia, Jose R

2015-01-01

During tumor progression, alterations within the systemic tumor environment, or macroenvironment, result in the promotion of tumor growth, tumor invasion to distal organs, and eventual metastatic disease. Distally produced hormones, commensal microbiota residing within mucosal surfaces, myeloid cells and even the bone marrow impact the systemic immune system, tumor growth, and metastatic spread. Understanding the reciprocal interactions between the cells and soluble factors within the macroenvironment and the primary tumor will enable the design of specific therapies that have the potential to prevent dissemination and metastatic spread. This chapter will summarize recent findings detailing how the primary tumor and systemic tumor macroenvironment coordinate malignant progression. © 2015 Elsevier Inc. All rights reserved.

Chronic ionizing radiation exposure as a tumor promoter in mouse skin

International Nuclear Information System (INIS)

Mitchel, R.E.J.; Trivedi, A.

1992-01-01

We have tested a chronic exposure to 90 Y beta-radiation as a tumor promoter in mouse skin previously exposed to a chemical tumor initiator. Three different tests of radiation as a stage I tumor promoter, in skin subsequently given chemical stage II promotion, all indicated that the beta-radiation acted as a weak stage I skin tumor promoter. It showed no action as either a stage II or complete tumor promoter. (author)

Differential acute and chronic response of protein kinase C in cultured neonatal rat heart myocytes to alpha 1-adrenergic and phorbol ester stimulation.

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Henrich, C J; Simpson, P C

1988-12-01

Both alpha 1-adrenergic agonists (e.g. norepinephrine, NE*) and tumor-promoting phorbol esters (e.g. phorbol myristate acetate, PMA) are known to activate protein kinase C (PKC) (Abdel-Latif, 1986, Niedel and Blackshear, 1986). However, alpha 1 agonists and PMA produce very different effects on cardiac function (see Simpson, 1985; Benfey, 1987; Meidell et al., 1986; Leatherman et al., 1987; Yuan et al., 1987; for examples). PKC activation in heart cells has been studied only for PMA treated perfused heart (Yuan et al., 1987). Therefore, acute activation and chronic regulation of PKC by NE and PMA were compared in cultured neonatal rat heart myocytes. NE acutely and transiently activated PKC, as measured by translocation of PKC activity to the cell particulate fraction (Niedel and Blackshear, 1986). Particulate PKC activity peaked at 23% of total after NE for 30 s, as compared with 8% for control (P less than 0.001). By contrast, acute PKC activation by PMA was more pronounced and persistent, with particulate PKC activity 62% of total at 5 min (P less than 0.001). Calcium/lipid-independent kinase activity increased acutely with PMA, but not with NE. Chronic treatment with NE (24 to 48 h) increased total per cell PKC activity and 3H-phorbol dibutyrate (PDB) binding sites, an index of the number of PKC molecules (Niedel and Blackshear, 1986), by 30 to 60% over control (all P less than 0.05 to 0.01). In contrast with NE, chronic treatment with PMA down-regulated PKC, reducing total per cell PKC activity and 3H-PDB binding sites to 3% and 12% of control, respectively (P less than 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)

Tumor Suppression and Promotion by Autophagy

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Yenniffer Ávalos

2014-01-01

Full Text Available Autophagy is a highly regulated catabolic process that involves lysosomal degradation of proteins and organelles, mostly mitochondria, for the maintenance of cellular homeostasis and reduction of metabolic stress. Problems in the execution of this process are linked to different pathological conditions, such as neurodegeneration, aging, and cancer. Many of the proteins that regulate autophagy are either oncogenes or tumor suppressor proteins. Specifically, tumor suppressor genes that negatively regulate mTOR, such as PTEN, AMPK, LKB1, and TSC1/2 stimulate autophagy while, conversely, oncogenes that activate mTOR, such as class I PI3K, Ras, Rheb, and AKT, inhibit autophagy, suggesting that autophagy is a tumor suppressor mechanism. Consistent with this hypothesis, the inhibition of autophagy promotes oxidative stress, genomic instability, and tumorigenesis. Nevertheless, autophagy also functions as a cytoprotective mechanism under stress conditions, including hypoxia and nutrient starvation, that promotes tumor growth and resistance to chemotherapy in established tumors. Here, in this brief review, we will focus the discussion on this ambiguous role of autophagy in the development and progression of cancer.

Tumor suppression and promotion by autophagy.

Science.gov (United States)

Ávalos, Yenniffer; Canales, Jimena; Bravo-Sagua, Roberto; Criollo, Alfredo; Lavandero, Sergio; Quest, Andrew F G

2014-01-01

Autophagy is a highly regulated catabolic process that involves lysosomal degradation of proteins and organelles, mostly mitochondria, for the maintenance of cellular homeostasis and reduction of metabolic stress. Problems in the execution of this process are linked to different pathological conditions, such as neurodegeneration, aging, and cancer. Many of the proteins that regulate autophagy are either oncogenes or tumor suppressor proteins. Specifically, tumor suppressor genes that negatively regulate mTOR, such as PTEN, AMPK, LKB1, and TSC1/2 stimulate autophagy while, conversely, oncogenes that activate mTOR, such as class I PI3K, Ras, Rheb, and AKT, inhibit autophagy, suggesting that autophagy is a tumor suppressor mechanism. Consistent with this hypothesis, the inhibition of autophagy promotes oxidative stress, genomic instability, and tumorigenesis. Nevertheless, autophagy also functions as a cytoprotective mechanism under stress conditions, including hypoxia and nutrient starvation, that promotes tumor growth and resistance to chemotherapy in established tumors. Here, in this brief review, we will focus the discussion on this ambiguous role of autophagy in the development and progression of cancer.

NADPH promotes the rapid growth of the tumor

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Hao Sheng

2018-04-01

Full Text Available NADPH oxidase is the main source of intracellular reactive oxygen species (ROS. ROS plays an important role in a variety of tumor types. The ROS mediated by NADPH oxidase increases the expression of hypoxia-inducible factor alpha (HIF-α through multiple signaling pathways in tumor, and HIF-α could be regulated and controlled by downstream multiple targeted genes such as vascular endothelial growth factor, glucose transporter to promote tumor angiogenesis, cell energy metabolism reprogram and tumor metastasis. Meanwhile, HIF-α can also regulate the expression of NADPH oxidase by ROS, thus further promoting development of tumor. In this review, we summarized the functions of NADPH in tumorigenesis and discussed their potential implications in cancer therapy.

Effects of protein kinase C activators on phorbol ester-sensitive and -resistant EL4 thymoma cells.

Science.gov (United States)

Sansbury, H M; Wisehart-Johnson, A E; Qi, C; Fulwood, S; Meier, K E

1997-09-01

Phorbol ester-sensitive EL4 murine thymoma cells respond to phorbol 12-myristate 13-acetate with activation of ERK mitogen-activated protein kinases, synthesis of interleukin-2, and death, whereas phorbol ester-resistant variants of this cell line do not exhibit these responses. Additional aspects of the resistant phenotype were examined, using a newly-established resistant cell line. Phorbol ester induced morphological changes, ERK activation, calcium-dependent activation of the c-Jun N-terminal kinase (JNK), interleukin-2 synthesis, and growth inhibition in sensitive but not resistant cells. A series of protein kinase C activators caused membrane translocation of protein kinase C's (PKCs) alpha, eta, and theta in both cell lines. While PKC eta was expressed at higher levels in sensitive than in resistant cells, overexpression of PKC eta did not restore phorbol ester-induced ERK activation to resistant cells. In sensitive cells, PKC activators had similar effects on cell viability and ERK activation, but differed in their abilities to induce JNK activation and interleukin-2 synthesis. PD 098059, an inhibitor of the mitogen activated protein (MAP)/ERK kinase kinase MEK, partially inhibited ERK activation and completely blocked phorbol ester-induced cell death in sensitive cells. Thus MEK and/or ERK activation, but not JNK activation or interleukin-2 synthesis, appears to be required for phorbol ester-induced toxicity. Alterations in phorbol ester response pathways, rather than altered expression of PKC isoforms, appear to confer phorbol ester resistance to EL4 cells.

Promotion of Tumor Invasion by Cooperation of Granulocytes and Macrophages Activated by Anti-tumor Antibodies

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Emilio Barbera-Guillem

1999-11-01

Full Text Available We investigated the potential role of anti-tumor antibodies and tumor antigens in the formation of immune complexes which promote matrix degradation and angiogenesis. B-cell deficient or B-cell depleted mice showed a reduction in tumor invasion and metastasis. In vitro invasion assays and in vivo models of metastasis showed that anti-sTn antibodies and sTn tumor antigens form complexes which induce granulocytes and macrophages together to mediate tumor invasion and metastasis by processes including extracellular matrix degradation and angiogenesis. These results suggest the existence of a tumor promoting role of a B-cell immune response induced by shed tumor associated antigens of solid, nonlymphoid tumors.

Analysis of seed phorbol-ester and curcin content together with genetic diversity in multiple provenances of Jatropha curcas L. from Madagascar and Mexico.

Science.gov (United States)

He, Wei; King, Andrew J; Khan, M Awais; Cuevas, Jesús A; Ramiaramanana, Danièle; Graham, Ian A

2011-10-01

Jatropha curcas L. has been promoted as an oilseed crop for use to meet the increased world demand for vegetable oil production, and in particular, as a feedstock for biodiesel production. Seed meal is a protein-rich by-product of vegetable oil extraction, which can either be used as an organic fertilizer, or converted to animal feed. However, conversion of J. curcas seed meal into animal feed is complicated by the presence of toxins, though plants producing "edible" or "non-toxic" seeds occur in Mexico. Toxins present in the seeds of J. curcas include phorbol esters and a type-I ribosome inactivating protein (curcin). Although the edible seeds of J. curcas are known to lack phorbol esters, the curcin content of these seeds has not previously been studied. We analyzed the phorbol ester and curcin content of J. curcas seeds obtained from Mexico and Madagascar, and conclude that while phorbol esters are lacking in edible seeds, both types contain curcin. We also analyzed spatial distribution of these toxins in seeds. Phorbol-esters were most concentrated in the tegmen. Curcin was found in both the endosperm and tegmen. We conclude that seed toxicity in J. curcas is likely to be due to a monogenic trait, which may be under maternal control. We also conducted AFLP analysis and conclude that genetic diversity is very limited in the Madagascan collection compared to the Mexican collection. Copyright © 2011 Elsevier Masson SAS. All rights reserved.

The effect of phorbols on metabolic cooperation between human fibroblasts

International Nuclear Information System (INIS)

Mosser, D.D.; Bols, N.C.

1982-01-01

Autoradiography has been used to study the effect of 12-O-tetradecanoylphorbol-13-acetate (TPA), 4-O-methyl TPA, and phorbol on metabolic cooperation between human diploid fibroblasts. When the donors, hypoxanthine-guanine phosphoribosyl transferase+ (HGPRT+) cells, and recipients, HGPRT- cells, were plated together in the presence of [ 3 H]hypoxanthine and either 4-O-methyl TPA or phorbol, nearly all interactions that developed in 4 h were positive for metabolic cooperation whereas when high concentrations of TPA were used, the number of positive interactions was significantly less than the control. If the phorbol analogs were added after the donors and recipients had made contact, the number of positive interactions was the same as the control in all cases. However, although primary recipients in the cultures that had been treated with phorbol had the same number of grains as those in the control, primary recipients in cultures that had been treated with TPA or high concentrations of 4-O-methyl TPA had significantly fewer grains than those in the control. TPA treatment for 4 h had no effect on total [ 3 H]hypoxanthine incorporation or incorporation into acid-soluble and acid-insoluble fractions. Thus, the effect of TPA on metabolic cooperation is interpreted as a reduction in the transfer of [ 3 H]nucleotides and is an indication of an interference with intercellular communication

Molecular Mechanisms of Mouse Skin Tumor Promotion

International Nuclear Information System (INIS)

Rundhaug, Joyce E.; Fischer, Susan M.

2010-01-01

Multiple molecular mechanisms are involved in the promotion of skin carcinogenesis. Induction of sustained proliferation and epidermal hyperplasia by direct activation of mitotic signaling pathways or indirectly in response to chronic wounding and/or inflammation, or due to a block in terminal differentiation or resistance to apoptosis is necessary to allow clonal expansion of initiated cells with DNA mutations to form skin tumors. The mitotic pathways include activation of epidermal growth factor receptor and Ras/Raf/mitogen-activated protein kinase signaling. Chronic inflammation results in inflammatory cell secretion of growth factors and cytokines such as tumor necrosis factor-α and interleukins, as well as production of reactive oxygen species, all of which can stimulate proliferation. Persistent activation of these pathways leads to tumor promotion

Quantitative Methylation Profiles for Multiple Tumor Suppressor Gene Promoters in Salivary Gland Tumors

Science.gov (United States)

Durr, Megan L.; Mydlarz, Wojciech K.; Shao, Chunbo; Zahurak, Marianna L.; Chuang, Alice Y.; Hoque, Mohammad O.; Westra, William H.; Liegeois, Nanette J.; Califano, Joseph A.; Sidransky, David; Ha, Patrick K.

2010-01-01

Background Methylation profiling of tumor suppressor gene (TSGs) promoters is quickly becoming a powerful diagnostic tool for the early detection, prognosis, and even prediction of clinical response to treatment. Few studies address this in salivary gland tumors (SGTs); hence the promoter methylation profile of various TSGs was quantitatively assessed in primary SGT tissue to determine if tumor-specific alterations could be detected. Methodology DNA isolated from 78 tumor and 17 normal parotid gland specimens was assayed for promoter methylation status of 19 TSGs by fluorescence-based, quantitative methylation-specific PCR (qMSP). The data were utilized in a binary fashion as well as quantitatively (using a methylation quotient) allowing for better profiling and interpretation of results. Principal Findings The average number of methylation events across the studied genes was highest in salivary duct carcinoma (SDC), with a methylation value of 9.6, compared to the normal 4.5 (ptrend for increasing methylation in APC, Mint 1, PGP9.5, RAR-β, and Timp3. Conclusions/Significance Screening promoter methylation profiles in SGTs showed considerable heterogeneity. The methylation status of certain markers was surprisingly high in even normal salivary tissue, confirming the need for such controls. Several TSGs were found to be associated with malignant SGTs, especially SDC. Further study is needed to evaluate the potential use of these associations in the detection, prognosis, and therapeutic outcome of these rare tumors. PMID:20520817

Evidence against roles for phorbol binding protein Munc13-1, ADAM adaptor Eve-1, or vesicle trafficking phosphoproteins Munc18 or NSF as phospho-state-sensitive modulators of phorbol/PKC-activated Alzheimer APP ectodomain shedding

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Lovestone Simon

2007-12-01

Full Text Available Abstract Background Shedding of the Alzheimer amyloid precursor protein (APP ectodomain can be accelerated by phorbol esters, compounds that act via protein kinase C (PKC or through unconventional phorbol-binding proteins such as Munc13-1. We have previously demonstrated that application of phorbol esters or purified PKC potentiates budding of APP-bearing secretory vesicles at the trans-Golgi network (TGN and toward the plasma membrane where APP becomes a substrate for enzymes responsible for shedding, known collectively as α-secretase(s. However, molecular identification of the presumptive "phospho-state-sensitive modulators of ectodomain shedding" (PMES responsible for regulated shedding has been challenging. Here, we examined the effects on APP ectodomain shedding of four phorbol-sensitive proteins involved in regulation of vesicular membrane trafficking of APP: Munc13-1, Munc18, NSF, and Eve-1. Results Overexpression of either phorbol-sensitive wildtype Munc13-1 or phorbol-insensitive Munc13-1 H567K resulted in increased basal APP ectodomain shedding. However, in contrast to the report of Roßner et al (2004, phorbol ester-dependent APP ectodomain shedding from cells overexpressing APP and Munc13-1 wildtype was indistinguishable from that observed following application of phorbol to cells overexpressing APP and Munc13-1 H567K mutant. This pattern of similar effects on basal and stimulated APP shedding was also observed for Munc18 and NSF. Eve-1, an ADAM adaptor protein reported to be essential for PKC-regulated shedding of pro-EGF, was found to play no obvious role in regulated shedding of sAPPα. Conclusion Our results indicate that, in the HEK293 system, Munc13-1, Munc18, NSF, and EVE-1 fail to meet essential criteria for identity as PMES for APP.

Evidence against roles for phorbol binding protein Munc13-1, ADAM adaptor Eve-1, or vesicle trafficking phosphoproteins Munc18 or NSF as phospho-state-sensitive modulators of phorbol/PKC-activated Alzheimer APP ectodomain shedding.

Science.gov (United States)

Ikin, Annat F; Causevic, Mirsada; Pedrini, Steve; Benson, Lyndsey S; Buxbaum, Joseph D; Suzuki, Toshiharu; Lovestone, Simon; Higashiyama, Shigeki; Mustelin, Tomas; Burgoyne, Robert D; Gandy, Sam

2007-12-09

Shedding of the Alzheimer amyloid precursor protein (APP) ectodomain can be accelerated by phorbol esters, compounds that act via protein kinase C (PKC) or through unconventional phorbol-binding proteins such as Munc13-1. We have previously demonstrated that application of phorbol esters or purified PKC potentiates budding of APP-bearing secretory vesicles at the trans-Golgi network (TGN) and toward the plasma membrane where APP becomes a substrate for enzymes responsible for shedding, known collectively as alpha-secretase(s). However, molecular identification of the presumptive "phospho-state-sensitive modulators of ectodomain shedding" (PMES) responsible for regulated shedding has been challenging. Here, we examined the effects on APP ectodomain shedding of four phorbol-sensitive proteins involved in regulation of vesicular membrane trafficking of APP: Munc13-1, Munc18, NSF, and Eve-1. Overexpression of either phorbol-sensitive wildtype Munc13-1 or phorbol-insensitive Munc13-1 H567K resulted in increased basal APP ectodomain shedding. However, in contrast to the report of Rossner et al (2004), phorbol ester-dependent APP ectodomain shedding from cells overexpressing APP and Munc13-1 wildtype was indistinguishable from that observed following application of phorbol to cells overexpressing APP and Munc13-1 H567K mutant. This pattern of similar effects on basal and stimulated APP shedding was also observed for Munc18 and NSF. Eve-1, an ADAM adaptor protein reported to be essential for PKC-regulated shedding of pro-EGF, was found to play no obvious role in regulated shedding of sAPPalpha. Our results indicate that, in the HEK293 system, Munc13-1, Munc18, NSF, and EVE-1 fail to meet essential criteria for identity as PMES for APP.

Increased phorbol 12,13-dibutyrate (PDBu) receptor function associated with sickle red cell membrane ghosts

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Ramachandran, M.; Nair, C.N.; Abraham, E.C.

1987-01-01

The biological receptor for tumor-promoting phorbol esters has been identified as the Ca 2+ /phospholipid dependent enzyme, protein kinase C. In the red cell, this enzyme is mainly cytosolic but becomes translocated to the membrane if the cellular Ca 2+ is allowed to rise. Since cellular Ca 2+ in sickle red cells is high, it was reasoned that this enzyme may become more membrane-bound. In fact, the authors noticed a four-fold increase in the binding of 3 H-PDBu by membrane ghosts isolated from sickle red cells compared to normal red cells (pmoles PDBu bound/mg protein; normal = 0.3 vs sickle cell = 1.4). Attempts to assay the enzyme directly as phospholipid-activated 32 P incorporation into the acid-precipitable membrane proteins also indicated a two-fold increase in the radiolabelling of sickle cell membrane ghosts. Autophosphorylation of membrane proteins and analysis of the phosphorylation profile by SDS-PAGE and autoradiography revealed phosphorylation predominantly of bands 3, 4.1 and 4.9 which are known protein kinase C substrates for the red cell enzyme. The increased membrane-associated protein kinase C in sickle red cells may have a bearing on the altered membrane properties reported in this condition

Hyperoxia, unlike phorbol ester, induces glutathione peroxidase through a protein kinase C-independent mechanism.

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Jornot, L; Junod, A F

1997-01-01

Human selenium-dependent glutathione peroxidase (GP) is implicated as a mechanism of resistance against oxygen free radicals. The 5' flanking sequence upstream from the coding region of GP contained an oxygen-responsive element termed ORE1 that is responsive to hypoxia, as well as several copies of the activator protein-1 (AP-1)- and AP-1-like-binding sites. In this study, we sought to define the molecular events that lead to GP gene transcription in response to hyperoxia in human umbilical-vein endothelial cells, and asked whether such induction is mimicked and sustained by activation of protein kinase C (PKC) by phorbol esters. Treatment of cells with 100 nM phorbol 12,13-dibutyrate (PdBu) induced a delayed (24-48 h) but significant (2-fold) increase in steady-state GP mRNA levels. Steady-state GP mRNA levels also rose after exposure to 95% O2, again after considerable delay (48-72 h). For both PdBu and oxygen, induction was transcriptionally regulated, as demonstrated by nuclear run-on experiments. The simulations by PdBu and oxygen were additive. In contrast with PdBu, hyperoxia did not stimulate translocation of PKC from the cytosol to the particulate fraction, although the specific activity of both cytosolic and particulate-associated PKC was increased 2-fold in cells exposed to 95% O2 for 5 days. In addition, gel mobility-shift assays using double-stranded tumour-promoting-agent-responsive element (TRE) and nuclear extracts derived from phorbol- and oxygen-treated cells revealed that PdBu, but not hyperoxia, increased AP-1 DNA-binding activity. On the other hand, the up-regulation of GP expression by oxygen could not be accounted for by the ORE1 core sequence, since no specific protein-DNA binding activity could be detected using nuclear extracts from hyperoxic cells and ORE1. Taken together, these results suggest that there may be different molecular mechanisms controlling GP expression. After exposure to PdBu, GP undergoes transcriptional activation via a

IL-33 activates tumor stroma to promote intestinal polyposis.

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Maywald, Rebecca L; Doerner, Stephanie K; Pastorelli, Luca; De Salvo, Carlo; Benton, Susan M; Dawson, Emily P; Lanza, Denise G; Berger, Nathan A; Markowitz, Sanford D; Lenz, Heinz-Josef; Nadeau, Joseph H; Pizarro, Theresa T; Heaney, Jason D

2015-05-12

Tumor epithelial cells develop within a microenvironment consisting of extracellular matrix, growth factors, and cytokines produced by nonepithelial stromal cells. In response to paracrine signals from tumor epithelia, stromal cells modify the microenvironment to promote tumor growth and metastasis. Here, we identify interleukin 33 (IL-33) as a regulator of tumor stromal cell activation and mediator of intestinal polyposis. In human colorectal cancer, IL-33 expression was induced in the tumor epithelium of adenomas and carcinomas, and expression of the IL-33 receptor, IL1RL1 (also referred to as IL1-R4 or ST2), localized predominantly to the stroma of adenoma and both the stroma and epithelium of carcinoma. Genetic and antibody abrogation of responsiveness to IL-33 in the Apc(Min/+) mouse model of intestinal tumorigenesis inhibited proliferation, induced apoptosis, and suppressed angiogenesis in adenomatous polyps, which reduced both tumor number and size. Similar to human adenomas, IL-33 expression localized to tumor epithelial cells and expression of IL1RL1 associated with two stromal cell types, subepithelial myofibroblasts and mast cells, in Apc(Min/+) polyps. In vitro, IL-33 stimulation of human subepithelial myofibroblasts induced the expression of extracellular matrix components and growth factors associated with intestinal tumor progression. IL-33 deficiency reduced mast cell accumulation in Apc(Min/+) polyps and suppressed the expression of mast cell-derived proteases and cytokines known to promote polyposis. Based on these findings, we propose that IL-33 derived from the tumor epithelium promotes polyposis through the coordinated activation of stromal cells and the formation of a protumorigenic microenvironment.

The impact of stress on tumor growth: peripheral CRF mediates tumor-promoting effects of stress

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Stathopoulos Efstathios N

2010-09-01

Full Text Available Abstract Introduction Stress has been shown to be a tumor promoting factor. Both clinical and laboratory studies have shown that chronic stress is associated with tumor growth in several types of cancer. Corticotropin Releasing Factor (CRF is the major hypothalamic mediator of stress, but is also expressed in peripheral tissues. Earlier studies have shown that peripheral CRF affects breast cancer cell proliferation and motility. The aim of the present study was to assess the significance of peripheral CRF on tumor growth as a mediator of the response to stress in vivo. Methods For this purpose we used the 4T1 breast cancer cell line in cell culture and in vivo. Cells were treated with CRF in culture and gene specific arrays were performed to identify genes directly affected by CRF and involved in breast cancer cell growth. To assess the impact of peripheral CRF as a stress mediator in tumor growth, Balb/c mice were orthotopically injected with 4T1 cells in the mammary fat pad to induce breast tumors. Mice were subjected to repetitive immobilization stress as a model of chronic stress. To inhibit the action of CRF, the CRF antagonist antalarmin was injected intraperitoneally. Breast tissue samples were histologically analyzed and assessed for neoangiogenesis. Results Array analysis revealed among other genes that CRF induced the expression of SMAD2 and β-catenin, genes involved in breast cancer cell proliferation and cytoskeletal changes associated with metastasis. Cell transfection and luciferase assays confirmed the role of CRF in WNT- β-catenin signaling. CRF induced 4T1 cell proliferation and augmented the TGF-β action on proliferation confirming its impact on TGFβ/SMAD2 signaling. In addition, CRF promoted actin reorganization and cell migration, suggesting a direct tumor-promoting action. Chronic stress augmented tumor growth in 4T1 breast tumor bearing mice and peripheral administration of the CRF antagonist antalarmin suppressed this

Infiltrating leukocytes confound the detection of E-cadherin promoter methylation in tumors

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Lombaerts, Marcel; Middeldorp, Janneke W.; Weide, Esther van der; Philippo, Katja; Wezel, Tom van; Smit, Vincent T.H.B.M.; Cornelisse, Cees J.; Cleton-Jansen, Anne-Marie

2004-01-01

Promoter hypermethylation is known to result in transcriptional downregulation of many genes including the CDH1 gene. In this study we set out to determine CDH1 promoter methylation in breast tumors with decreased or absent E-cadherin protein expression and without CDH1 gene mutations by methylation-specific PCR (MSP). Interestingly, some tumor samples with normal E-cadherin expression yielded a methylation-specific PCR product. We hypothesized that other cells than tumor cells contribute to these products. Since in normal breast tissue no CDH1 promoter methylation is detected, infiltrating leukocytes, often present in tumors, might account for these methylation-specific fragments. Indeed, a methylation-specific fragment is found in all twelve leukocyte samples tested. Furthermore, activated T-cells also yielded a methylation-specific fragment. Sequencing of these fragments reveals two distinct methylation profiles. Leukocytes have only partial methylation of some CpGs, while the tumor-associated methylation profile shows complete methylation of most CpGs. Therefore, to assess whether CDH1 methylation is tumor associated, sequencing of MSP products is a prerequisite. Here we show that out of six lobular tumors lacking E-cadherin protein expression, three have tumor-associated CDH1 promoter methylation while in three other tumors no methylation is detected

Tumor-extrinsic discoidin domain receptor 1 promotes mammary tumor growth by regulating adipose stromal interleukin 6 production in mice.

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Sun, Xiujie; Gupta, Kshama; Wu, Bogang; Zhang, Deyi; Yuan, Bin; Zhang, Xiaowen; Chiang, Huai-Chin; Zhang, Chi; Curiel, Tyler J; Bendeck, Michelle P; Hursting, Stephen; Hu, Yanfen; Li, Rong

2018-02-23

Discoidin domain receptor 1 (DDR1) is a collagen receptor that mediates cell communication with the extracellular matrix (ECM). Aberrant expression and activity of DDR1 in tumor cells are known to promote tumor growth. Although elevated DDR1 levels in the stroma of breast tumors are associated with poor patient outcome, a causal role for tumor-extrinsic DDR1 in cancer promotion remains unclear. Here we report that murine mammary tumor cells transplanted to syngeneic recipient mice in which Ddr1 has been knocked out (KO) grow less robustly than in WT mice. We also found that the tumor-associated stroma in Ddr1- KO mice exhibits reduced collagen deposition compared with the WT controls, supporting a role for stromal DDR1 in ECM remodeling of the tumor microenvironment. Furthermore, the stromal-vascular fraction (SVF) of Ddr1 knockout adipose tissue, which contains committed adipose stem/progenitor cells and preadipocytes, was impaired in its ability to stimulate tumor cell migration and invasion. Cytokine array-based screening identified interleukin 6 (IL-6) as a cytokine secreted by the SVF in a DDR1-dependent manner. SVF-produced IL-6 is important for SVF-stimulated tumor cell invasion in vitro , and, using antibody-based neutralization, we show that tumor promotion by IL-6 in vivo requires DDR1. In conclusion, our work demonstrates a previously unrecognized function of DDR1 in promoting tumor growth. © 2018 by The American Society for Biochemistry and Molecular Biology, Inc.

Degradation of phorbol esters by Pseudomonas aeruginosa PseA during solid-state fermentation of deoiled Jatropha curcas seed cake.

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Joshi, Chetna; Mathur, Priyanka; Khare, S K

2011-04-01

Large amount of seed cake is generated as by-product during biodiesel production from Jatropha seeds. Presence of toxic phorbol esters restricts its utilization as livestock feed. Safe disposal or meaningful utilization of this major by-product necessitates the degradation of these phorbol esters. The present study describes the complete degradation of phorbol esters by Pseudomonas aeruginosa PseA strain during solid state fermentation (SSF) of deoiled Jatropha curcas seed cake. Phorbol esters were completely degraded in nine days under the optimized SSF conditions viz. deoiled cake 5.0 g; moistened with 5.0 ml distilled water; inoculum 1.5 ml of overnight grown P. aeruginosa; incubation at temperature 30 °C, pH 7.0 and RH 65%. SSF of deoiled cake seems a potentially viable approach towards the complete degradation of the toxic phorbol esters. Copyright © 2011 Elsevier Ltd. All rights reserved.

Tumor Restrictive Suicide Gene Therapy for Glioma Controlled by the FOS Promoter.

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Jianqing Pan

Full Text Available Effective suicide gene delivery and expression are crucial to achieving successful effects in gene therapy. An ideal tumor-specific promoter expresses therapeutic genes in tumor cells with minimal normal tissue expression. We compared the activity of the FOS (FBJ murine osteosarcoma viral oncogene homolog promoter with five alternative tumor-specific promoters in glioma cells and non-malignant astrocytes. The FOS promoter caused significantly higher transcriptional activity in glioma cell lines than all alternative promoters with the exception of CMV. The FOS promoter showed 13.9%, 32.4%, and 70.8% of the transcriptional activity of CMV in three glioma cell lines (U87, U251, and U373. Importantly, however, the FOS promoter showed only 1.6% of the transcriptional activity of CMV in normal astrocytes. We also tested the biologic activity of recombinant adenovirus containing the suicide gene herpes simplex virus thymidine kinase (HSV-tk driven by the FOS promoter, including selective killing efficacy in vitro and tumor inhibition rate in vivo. Adenoviral-mediated delivery of the HSV-tk gene controlled by the FOS promoter conferred a cytotoxic effect on human glioma cells in vitro and in vivo. This study suggests that use of the FOS-tk adenovirus system is a promising strategy for glioma-specific gene therapy but still much left for improvement.

Inhibition of hepatocyte gap junctional intercellular communication by tumor promoters

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Ruch, R.J.

1988-01-01

The mechanisms by which tumor promoters enhance neoplasia are poorly understood. One effect common to most tumor promoters is their ability to inhibit the cell-to-cell exchange of small molecules and ions through gap junctions, i.e., gap junctional intercellular communication (IC). IC maybe necessary for normal growth control and the loss of IC may predispose cells to enhanced growth. In the present studies, the effects of liver tumor promoters and other agents on IC between rodent hepatocytes in primary culture has been studied. IC was detected between hepatocytes: (1) autoradiographically following the passage and incorporation of [5- 3 H]uridine nucleotides from pre-labeled donor hepatocytes to non-labeled, adjacent recipient hepatocytes and (2) by fluorescence microscopy after microinjection of fluorescent Lucifer Yellow CH dye into hepatocytes and visualizing dye spread into adjacent hepatocytes

RasGRP1 confers the phorbol ester-sensitive phenotype to EL4 lymphoma cells.

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Han, Shujie; Knoepp, Stewart M; Hallman, Mark A; Meier, Kathryn E

2007-01-01

The murine EL4 lymphoma cell line exists in variants that are either sensitive or resistant to the tumor promoter phorbol 12-myristate 13-acetate (PMA). In sensitive EL4 cells, PMA causes robust Erk mitogen-activated protein kinase activation that results in growth arrest. In resistant cells, PMA induces minimal Erk activation, without growth arrest. PMA stimulates IL-2 production in sensitive, but not resistant, cells. The role of RasGRP1, a PMA-activated guanine nucleotide exchange factor for Ras, in EL4 phenotype was examined. Endogenous RasGRP1 protein is expressed at much higher levels in sensitive than in resistant cells. PMA-induced Ras activation is observed in sensitive cells but not in resistant cells lacking Ras-GRP1. PMA induces down-regulation of RasGRP1 protein in sensitive cells but increases RasGRP1 in resistant cells. Transfection of RasGRP1 into resistant cells enhances PMA-induced Erk activation. In the reverse experiment, introduction of small interfering RNA (siRNA) for RasGRP1 suppresses PMA-induced Ras and Erk activations in sensitive cells. Sensitive cells incubated with siRNA for RasGRP1 exhibit the PMA-resistant phenotype, in that they are able to proliferate in the presence of PMA and do not secrete IL-2 when stimulated with PMA. These studies indicate that the PMA-sensitive phenotype, as previously defined for the EL4 cell line, is conferred by endogenous expression of RasGRP1 protein.

Deficient tyrosine phosphorylation of c-Cbl and associated proteins in phorbol ester-resistant EL4 mouse thymoma cells.

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Luo, X; Sando, J J

1997-05-02

Two tyrosine phosphoproteins in phorbol ester-sensitive EL4 (S-EL4) mouse thymoma cells have been identified as the p120 c-Cbl protooncogene product and the p85 subunit of phosphatidylinositol 3-kinase. Tyrosine phosphorylation of p120 and p85 increased rapidly after phorbol ester stimulation. Phorbol ester-resistant EL4 (R-EL4) cells expressed comparable amounts of c-Cbl and phosphatidylinositol 3-kinase protein but greatly diminished tyrosine phosphorylation. Co-immunoprecipitation experiments revealed complexes of c-Cbl with p85, and of p85 with the tyrosine kinase Lck in phorbol ester-stimulated S-EL4 but not in unstimulated S-EL4 or in R-EL4 cells. In vitro binding of c-Cbl with Lck SH2 or SH3 domains was detected in both S-EL4 and R-EL4 cells, suggesting that c-Cbl, p85, and Lck may form a ternary complex. In vitro kinase assays revealed phosphorylation of p85 by Lck only in phorbol ester-stimulated S-EL4 cells. Collectively, these results suggest that Cbl-p85 and Lck-p85 complexes may form in unstimulated S-EL4 and R-EL4 cells but were not detected due to absence of tyrosine phosphorylation of p85. Greatly decreased tyrosine phosphorylation of c-Cbl and p85 in the complexes may contribute to the failure of R-EL4 cells to respond to phorbol ester.

Resveratrol inhibits phorbol ester-induced membrane translocation of presynaptic Munc13-1.

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Pany, Satyabrata; Ghosh, Anamitra; You, Youngki; Nguyen, Nga; Das, Joydip

2017-11-01

Resveratrol (1) is a naturally occurring polyphenol that has been implicated in neuroprotection. One of resveratrol's several biological targets is Ca 2+ -sensitive protein kinase C alpha (PKCα). Resveratrol inhibits PKCα by binding to its activator-binding C1 domain. Munc13-1 is a C1 domain-containing Ca 2+ -sensitive SNARE complex protein essential for vesicle priming and neurotransmitter release. To test if resveratrol could also bind and inhibit Munc13-1, we studied the interaction of resveratrol and its derivatives, (E)-1,3-dimethoxy-5-(4-methoxystyryl)benzene, (E)-5,5'-(ethene-1,2-diyl)bis(benzene-1,2,3-triol), (E)-1,2-bis(3,4,5-trimethoxyphenyl)ethane, and (E)-5-(4-(hexadecyloxy)-3,5-dihydroxystyryl)benzene-1,2,3-triol with Munc13-1 by studying its membrane translocation from cytosol to plasma membrane in HT22 cells and primary hippocampal neurons. Resveratrol, but not the derivatives inhibited phorbol ester-induced Munc13-1 translocation from cytosol to membrane in HT22 cells and primary hippocampal neurons, as evidenced by immunoblot analysis and confocal microscopy. Resveratrol did not show any effect on Munc13-1 H567K , a mutant which is not sensitive to phorbol ester. Binding studies with Munc13-1 C1 indicated that resveratrol competes with phorbol ester for the binding site. Molecular docking and dynamics studies suggested that hydroxyl groups of resveratrol interact with phorbol-ester binding residues in the binding pocket. This study characterizes Munc13-1 as a target of resveratrol and highlights the importance of dietary polyphenol in the management of neurodegenerative diseases. Copyright © 2017 Elsevier B.V. All rights reserved.

Ets2 in tumor fibroblasts promotes angiogenesis in breast cancer.

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Julie A Wallace

Full Text Available Tumor fibroblasts are active partners in tumor progression, but the genes and pathways that mediate this collaboration are ill-defined. Previous work demonstrates that Ets2 function in stromal cells significantly contributes to breast tumor progression. Conditional mouse models were used to study the function of Ets2 in both mammary stromal fibroblasts and epithelial cells. Conditional inactivation of Ets2 in stromal fibroblasts in PyMT and ErbB2 driven tumors significantly reduced tumor growth, however deletion of Ets2 in epithelial cells in the PyMT model had no significant effect. Analysis of gene expression in fibroblasts revealed a tumor- and Ets2-dependent gene signature that was enriched in genes important for ECM remodeling, cell migration, and angiogenesis in both PyMT and ErbB2 driven-tumors. Consistent with these results, PyMT and ErbB2 tumors lacking Ets2 in fibroblasts had fewer functional blood vessels, and Ets2 in fibroblasts elicited changes in gene expression in tumor endothelial cells consistent with this phenotype. An in vivo angiogenesis assay revealed the ability of Ets2 in fibroblasts to promote blood vessel formation in the absence of tumor cells. Importantly, the Ets2-dependent gene expression signatures from both mouse models were able to distinguish human breast tumor stroma from normal stroma, and correlated with patient outcomes in two whole tumor breast cancer data sets. The data reveals a key function for Ets2 in tumor fibroblasts in signaling to endothelial cells to promote tumor angiogenesis. The results highlight the collaborative networks that orchestrate communication between stromal cells and tumor cells, and suggest that targeting tumor fibroblasts may be an effective strategy for developing novel anti-angiogenic therapies.

Tumor-Induced Generation of Splenic Erythroblast-like Ter-Cells Promotes Tumor Progression.

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Han, Yanmei; Liu, Qiuyan; Hou, Jin; Gu, Yan; Zhang, Yi; Chen, Zhubo; Fan, Jia; Zhou, Weiping; Qiu, Shuangjian; Zhang, Yonghong; Dong, Tao; Li, Ning; Jiang, Zhengping; Zhu, Ha; Zhang, Qian; Ma, Yuanwu; Zhang, Lianfeng; Wang, Qingqing; Yu, Yizhi; Li, Nan; Cao, Xuetao

2018-04-19

Identifying tumor-induced leukocyte subsets and their derived circulating factors has been instrumental in understanding cancer as a systemic disease. Nevertheless, how primary tumor-induced non-leukocyte populations in distal organs contribute to systemic spread remains poorly defined. Here, we report one population of tumor-inducible, erythroblast-like cells (Ter-cells) deriving from megakaryocyte-erythroid progenitor cells with a unique Ter-119 + CD45 - CD71 + phenotype. Ter-cells are enriched in the enlarged spleen of hosts bearing advanced tumors and facilitate tumor progression by secreting neurotrophic factor artemin into the blood. Transforming growth factor β (TGF-β) and Smad3 activation are important in Ter-cell generation. In vivo blockade of Ter-cell-derived artemin inhibits hepatocellular carcinoma (HCC) growth, and artemin deficiency abolishes Ter-cells' tumor-promoting ability. We confirm the presence of splenic artemin-positive Ter-cells in human HCC patients and show that significantly elevated serum artemin correlates with poor prognosis. We propose that Ter-cells and the secreted artemin play important roles in cancer progression with prognostic and therapeutic implications. Copyright © 2018 Elsevier Inc. All rights reserved.

Tumor-Derived CXCL1 Promotes Lung Cancer Growth via Recruitment of Tumor-Associated Neutrophils

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Ming Yuan

2016-01-01

Full Text Available Neutrophils have a traditional role in inflammatory process and act as the first line of defense against infections. Although their contribution to tumorigenesis and progression is still controversial, accumulating evidence recently has demonstrated that tumor-associated neutrophils (TANs play a key role in multiple aspects of cancer biology. Here, we detected that chemokine CXCL1 was dramatically elevated in serum from 3LL tumor-bearing mice. In vitro, 3LL cells constitutively expressed and secreted higher level of CXCL1. Furthermore, knocking down CXCL1 expression in 3LL cells significantly hindered tumor growth by inhibiting recruitment of neutrophils from peripheral blood into tumor tissues. Additionally, tumor-infiltrated neutrophils expressed higher levels of MPO and Fas/FasL, which may be involved in TAN-mediated inhibition of CD4+ and CD8+ T cells. These results demonstrate that tumor-derived CXCL1 contributes to TANs infiltration in lung cancer which promotes tumor growth.

Curcumin and Turmeric Modulate the Tumor-Promoting Effects of Iron In Vitro.

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Messner, Donald J; Robinson, Todd; Kowdley, Kris V

2017-04-01

Free or loosely chelated iron has tumor-promoting properties in vitro. Curcumin, a polyphenol derived from the food spice turmeric (Curcuma longa), is a potent antioxidant that binds iron. The primary aim of this study was to investigate whether curcuminoids prevent tumor-promoting effects of iron in T51B cells, a non-neoplastic rat liver epithelial cell line. Purified curcuminoids (curcumin) or a standardized turmeric extract similarly reduced oxidative stress and cytotoxicity associated with iron overload (IC 50 values near 10 μM, P turmeric for 16 wk in culture; subsequently assayed by soft agar colony formation) was nearly complete at 20 μM of total curcuminoids (P turmeric extract were taken up better by cells, had a longer half-life, and appeared more effective in blocking tumor promotion (P < 0.01), suggesting enhanced curcuminoid delivery to cells in culture. The primary finding that curcuminoids can inhibit tumor promotion caused by iron in T51B cells is tempered by evidence for an underlying increase in neoplastic transformation at lower concentrations.

Codon 61 mutations in the c-Harvey-ras gene in mouse skin tumors induced by 7,12-dimethylbenz[a]anthracene plus okadaic acid class tumor promoters.

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Fujiki, H; Suganuma, M; Yoshizawa, S; Kanazawa, H; Sugimura, T; Manam, S; Kahn, S M; Jiang, W; Hoshina, S; Weinstein, I B

1989-01-01

Three okadaic acid class tumor promoters, okadaic acid, dinophysistoxin-1, and calyculin A, have potent tumor-promoting activity in two-stage carcinogenesis experiments on mouse skin. DNA isolated from tumors induced by 7,12-dimethylbenz[a]anthracene (DMBA) and each of these tumor promoters revealed the same mutation at the second nucleotide of codon 61 (CAA----CTA) in the c-Ha-ras gene, determined by the polymerase chain reaction procedure and DNA sequencing. Three potent 12-O-tetradecanoylphorbol-13-acetate (TPA)-type tumor promoters, TPA, teleocidin, and aplysiatoxin, showed the same effects. These results provide strong evidence that this mutation in the c-Ha-ras gene is due to a direct effect of DMBA rather than a selective effect of specific tumor promoters.

Selective up-regulation of protein kinase C eta in phorbol ester-sensitive versus -resistant EL4 mouse thymoma cells.

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Resnick, M S; Luo, X; Vinton, E G; Sando, J J

1997-06-01

Stimulation of sensitive EL4 mouse thymoma cells (s-EL4) with phorbol esters results in production of interleukin 2 (IL-2), adherence to a plastic substrate, and growth inhibition, whereas a phorbol ester-resistant variant (r-EL4) fails to respond. Previous studies revealed substantially decreased expression of protein kinase C (PKC) epsilon in the r-EL4 versus s-EL4 cells. This work has been extended to examine the more recently described PKC isozymes. Western and Northern analyses revealed a marked decrease in PKC eta and theta in r-EL4 as compared to s-EL4 cells. Treatment of these lines with phorbol ester for 24 h resulted in down-regulation of all PKC isozymes examined except PKC eta, which was up-regulated in the s-EL4 cells at the time of maximal IL-2 production. Two newly isolated EL4 clones, resistant to phorbol ester-induced growth inhibition but still exhibiting the phorbol ester-induced adherence and IL-2 production, both expressed PKC eta and theta. Collectively, these observations suggest a dissociation of growth inhibition from adherence and IL-2 production pathways and a potential role for PKC eta in the latter.

Induction of transcription from the long terminal repeat of Moloney murine sarcoma provirus by UV-irradiation, x-irradiation, and phorbol ester

International Nuclear Information System (INIS)

Lin, C.S.; Goldthwait, D.A.; Samols, D.

1990-01-01

The long terminal repeat (LTR) of Moloney murine sarcoma virus (Mo-MuSV) was used as a model system to study the stress response of mammalian cells to physical carcinogens. The chloramphenicol acetyltransferase (CAT) gene was inserted between two Mo-MuSV LTRs, and the LTR-CAT-LTR construct was used for virus production and was integrated into the genome of NIH 3T3 cells in the proviral form. This construct was used to assure that the integrated CAT gene was driven by the promoter of the LTR. Expression of the CAT gene was stimulated 4-fold by UV irradiation, and the peak of activity was observed at 18 hr. In contrast, stimulation of the CAT expression after x-irradiation was 2-fold and occurred at 6 hr. Phorbol myristate acetate also stimulated CAT activity 4-fold with a peak at 6 hr. Down-regulation of protein kinase C blocked totally the response to x-irradiation but only partially the response to UV. The protein kinase inhibitor H7 blocked the response to treatment by UV, x-ray, and phorbol ester

Platelets Promote Metastasis via Binding Tumor CD97 Leading to Bidirectional Signaling that Coordinates Transendothelial Migration

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Yvona Ward

2018-04-01

Full Text Available Summary: Tumor cells initiate platelet activation leading to the secretion of bioactive molecules, which promote metastasis. Platelet receptors on tumors have not been well-characterized, resulting in a critical gap in knowledge concerning platelet-promoted metastasis. We identify a direct interaction between platelets and tumor CD97 that stimulates rapid bidirectional signaling. CD97, an adhesion G protein-coupled receptor (GPCR, is an overexpressed tumor antigen in several cancer types. Purified CD97 extracellular domain or tumor cell-associated CD97 stimulated platelet activation. CD97-initiated platelet activation led to granule secretion, including the release of ATP, a mediator of endothelial junction disruption. Lysophosphatidic acid (LPA derived from platelets induced tumor invasiveness via proximal CD97-LPAR heterodimer signaling, coupling coincident tumor cell migration and vascular permeability to promote transendothelial migration. Consistent with this, CD97 was necessary for tumor cell-induced vascular permeability in vivo and metastasis formation in preclinical models. These findings support targeted blockade of tumor CD97 as an approach to ameliorate metastatic spread. : Tumor-initiated platelet activation promotes tissue invasion of cancer cells and metastasis. Ward et al. demonstrate that a common tumor-associated antigen, CD97, accounts for platelet activation and participates directly in LPA-mediated signal transduction leading to tumor cell invasion. CD97 promotes vascular extravasation and metastasis in pre-clinical models. Keywords: platelets, metastasis, transendothelial migration, circulating tumor cells, CD97, adhesion GPCR, LPA

Reciprocal modulation of mesenchymal stem cells and tumor cells promotes lung cancer metastasis

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Giulia Fregni

2018-03-01

Full Text Available Metastasis is a multi-step process in which direct crosstalk between cancer cells and their microenvironment plays a key role. Here, we assessed the effect of paired tumor-associated and normal lung tissue mesenchymal stem cells (MSCs on the growth and dissemination of primary human lung carcinoma cells isolated from the same patients. We show that the tumor microenvironment modulates MSC gene expression and identify a four-gene MSC signature that is functionally implicated in promoting metastasis. We also demonstrate that tumor-associated MSCs induce the expression of genes associated with an aggressive phenotype in primary lung cancer cells and selectively promote their dissemination rather than local growth. Our observations provide insight into mechanisms by which the stroma promotes lung cancer metastasis. Keywords: Tumor-associated MSCs, lung cancer, metastasis, GREM1, LOXL2, ADAMTS12, ITGA11

Soy protein isolate inhibits hepatic tumor promotion in mice fed a high-fat liquid diet.

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Mercer, Kelly E; Pulliam, Casey F; Pedersen, Kim B; Hennings, Leah; Ronis, Martin Jj

2017-03-01

Alcoholic and nonalcoholic fatty liver diseases are risk factors for development of hepatocellular carcinoma, but the underlying mechanisms are poorly understood. On the other hand, ingestion of soy-containing diets may oppose the development of certain cancers. We previously reported that replacing casein with a soy protein isolate reduced tumor promotion in the livers of mice with alcoholic liver disease after feeding a high fat ethanol liquid diet following initiation with diethylnitrosamine. Feeding soy protein isolate inhibited processes that may contribute to tumor promotion including inflammation, sphingolipid signaling, and Wnt/β-catenin signaling. We have extended these studies to characterize liver tumor promotion in a model of nonalcoholic fatty liver disease produced by chronic feeding of high-fat liquid diets in the absence of ethanol. Mice treated with diethylnitrosamine on postnatal day 14 were fed a high-fat liquid diet made with casein or SPI as the sole protein source for 16 weeks in adulthood. Relative to mice fed normal chow, a high fat/casein diet led to increased tumor promotion, hepatocyte proliferation, steatosis, and inflammation. Replacing casein with soy protein isolate counteracted these effects. The high fat diets also resulted in a general increase in transcripts for Wnt/β-catenin pathway components, which may be an important mechanism, whereby hepatic tumorigenesis is promoted. However, soy protein isolate did not block Wnt signaling in this nonalcoholic fatty liver disease model. We conclude that replacing casein with soy protein isolate blocks development of steatosis, inflammation, and tumor promotion in diethylnitrosamine-treated mice fed high fat diets. Impact statement The impact of dietary components on cancer is a topic of great interest for both the general public and the scientific community. Liver cancer is currently the second leading form of cancer deaths worldwide. Our study has addressed the effect of the protein

CXCL17 expression by tumor cells recruits CD11b+Gr1 high F4/80- cells and promotes tumor progression.

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Aya Matsui

Full Text Available BACKGROUND: Chemokines are involved in multiple aspects of pathogenesis and cellular trafficking in tumorigenesis. In this study, we report that the latest member of the C-X-C-type chemokines, CXCL17 (DMC/VCC-1, recruits immature myeloid-derived cells and enhances early tumor progression. METHODOLOGY/PRINCIPAL FINDINGS: CXCL17 was preferentially expressed in some aggressive types of gastrointestinal, breast, and lung cancer cells. CXCL17 expression did not impart NIH3T3 cells with oncogenic potential in vitro, but CXCL17-expressing NIH3T3 cells could form vasculature-rich tumors in immunodeficient mice. Our data showed that CXCL17-expressing tumor cells increased immature CD11b(+Gr1(+ myeloid-derived cells at tumor sites in mice and promoted CD31(+ tumor angiogenesis. Extensive chemotactic assays proved that CXCL17-responding cells were CD11b(+Gr1(highF4/80(- cells (≈ 90% with a neutrophil-like morphology in vitro. Although CXCL17 expression could not increase the number of CD11b(+Gr1(+ cells in tumor-burdened SCID mice or promote metastases of low metastatic colon cancer cells, the existence of CXCL17-responding myeloid-derived cells caused a striking enhancement of xenograft tumor formation. CONCLUSIONS/SIGNIFICANCE: These results suggest that aberrant expression of CXCL17 in tumor cells recruits immature myeloid-derived cells and promotes tumor progression through angiogenesis.

Alteration of keratinocyte differentiation and senescence by the tumor promoter dioxin

International Nuclear Information System (INIS)

Ray, Soma S.; Swanson, Hollie I.

2003-01-01

Exposure to the environmental contaminant dioxin, elicits a variety of responses, which includes tumor promotion, embryotoxicity/teratogenesis, and carcinogenesis in both animals and humans. Many of the effects of dioxin are mediated by the aryl hydrocarbon receptor (AHR), a ligand-activated bHLH (basic helix-loop-helix)/PAS transcription factor. We initiated this study to determine whether dioxin's tumor-promoting activities may lie in its ability to alter proliferation, differentiation, and/or senescence using normal human epidermal keratinocytes (HEKs). Here, we report that dioxin appears to accelerate differentiation as measured by flow cytometry and by increased expression of the differentiation markers involucrin and filaggrin. In addition, dioxin appears to increase proliferation as indicated by an increase in NADH/NADPH production and changes in cell cycle. Finally, dioxin decreases SA (senescence associated) β-galactosidase staining, an indicator of senescence, in the differentiating keratinocytes. These changes were accompanied by decreases in the expression levels of key cell cycle regulatory proteins p53, p16 INK4a , and p14 ARF . Our findings support the idea that dioxin may exert its tumor-promoting actions, in part, by downregulating the expression levels of key tumor suppressor proteins, which may impair the cell's ability to maintain its appropriate cellular status

Industasis, a promotion of tumor formation by nontumorigenic stray cells

Czech Academy of Sciences Publication Activity Database

Pajer, Petr; Karafiát, Vít; Pečenka, Vladimír; Průková, Dana; Dudlová, J.; Plachý, Jiří; Kašparová, P.; Dvořák, Michal

2009-01-01

Roč. 69, č. 11 (2009), s. 4605-4612 ISSN 0008-5472 R&D Projects: GA ČR GA204/06/1728; GA MŠk(CZ) LC06061; GA AV ČR IAA500520608 Institutional research plan: CEZ:AV0Z50520514 Keywords : tumor promotion * lung tumors * Fyn-related kinase Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 7.543, year: 2009

Modulation of the transient receptor potential vanilloid channel TRPV4 by 4alpha-phorbol esters: a structure-activity study

DEFF Research Database (Denmark)

Klausen, Thomas Kjaer; Pagani, Alberto; Minassi, Alberto

2009-01-01

The mechanism of activation of the transient receptor potential vanilloid 4 (TRPV4) channel by 4alpha-phorbol esters was investigated by combining information from chemical modification of 4alpha-phorbol-didecanoate (4alpha-PDD, 2a), site-directed mutagenesis, Ca(2+) imaging, and electrophysiology....... Binding of 4alpha-phorbol esters occurs in a loop in the TM3-TM4 domain of TRPV4 that is analogous to the capsaicin binding site of TRPV1, and the ester decoration of ring C and the A,B ring junction are critical for activity. The lipophilic ester groups on ring C serve mainly as a steering element...

Ontogeny of phorbol ester receptors in rat brain studied by in vitro autoradiography

International Nuclear Information System (INIS)

Miyoshi, R.; Kito, S.

1990-01-01

The ontogeny of phorbol ester receptors, which have been considered to correspond to protein kinase C, in the rat brain was studied through in vitro autoradiography with 3 H-phorbol 12,13-dibutyrate ( 3 H-PDBu). The distribution of 3 H-PDBu binding sites in the adult rat brain was similar to the previous reports by other researchers. The developmental pattern of 3 H-PDBu binding sites varried with brain region. 3 H-PDBu binding sites in the amygdala, thalamus, stratum pyramidale of CA 1 of the hippocampus, dentate gyrus, superior colliculus, substantia nigra, interpeduncular nucleus and cerebellar molecular layer were postnatally increased to adult levels and after that they remained constant. On the other hand, in the stratum oriens and stratum radiatum of CA 1 of the hippocampus, and in the lateral and medial geniculate bodies, 3 H-PDBu binding sites reached peaks at 21 or 28 days of postnatal age and after that they declined to adult levels. The cerebellar granular layer showed a low level of 3 H-PDBu binding sites throughout all the ontogenetic stages. A distinct ontogenetic pattern of phorbol ester receptors in various regions of the brain may reflect a role of protein kinase C in the neural development of each discrete area. (Authors)

Studies on the tumor initiation/promotion potential of six middle distillates (MDs) in mouse skin.

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Jungen, H; Mellert, W; Wenzel-Hartung, R

1995-08-01

Six middle distillates (MDs) were tested for tumor initiating/promoting activity after application to the skin of 30 male CD-1 (ICR) BR mice per group. As the control, 7,12-dimethylbenz[a]-anthracene (DMBA) was used for initiation followed by 12-O-tetradecanoylphorbol-13-acetate (TPA) for promotion. For assessing the tumor-initiating activity, 50 microliters of neat MDs was administered for 5 days with subsequent TPA promotion. In the promotion bioassay, after DMBA initiation 50 microliters of the neat MDs was administered twice weekly until Week 28. For the examination of complete carcinogenic activity, one MD was given without DMBA initiation. Hyperkeratosis, hyperplasia, and dermal inflammation, occurring during the initiation with the MDs, were completely reversible during the 2-week treatment-free period after initiation. Similar skin findings were observed during promotion with the MDs. Regarding the number of affected animals and the severity of the response, TPA was more irritating than the MDs. The initiation study revealed skin tumors for the DMBA/TPA control (30/30), MD 57,389 (14/30), MD 57,396 (5/30), MD 57,383 (4/30) and MD 57,324 (2/30). The promotion study revealed tumor induction by MDs 57,389 (9/30), 57,324 (1/30), 57,393 (1/30), and 57,396 (1/30). Two of 30 animals treated with MD 57,389 developed tumors without DMBA initiation thus indicating that it also is a complete carcinogen. MD 57,399 caused neither initiating nor promoting effects. The tumors observed were diagnosed histopathologically predominantly as squamous cell papillomas.(ABSTRACT TRUNCATED AT 250 WORDS)

Sesquiterpene lactones isolated from indigenous Middle Eastern plants inhibit tumor promoter-induced transformation of JB6 cells

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Saikali Melody

2012-07-01

Full Text Available Abstract Background Sesquiterpene lactones (SL are plant secondary metabolites that are known for their anti-fungal, anti-bacterial, anti-inflammatory, and anti-tumor properties. Considering that several SL-derived drugs are currently in cancer clinical trials, we have tested two SL molecules, 3-β-methoxy-iso-seco-tanapartholide (β-tan isolated from Achillea falcata and salograviolide A (Sal A isolated from Centaurea ainetensis, for their anti-tumor properties. We used the mouse epidermal JB6P + cells as a model for tumor promotion and cellular transformation. Key players that are involved in cellular transformation and tumorigenesis are the AP-1 and NF-κB transcription factors; therefore, we assessed how β-tan and Sal A modulate their signaling pathways in JB6P + cells. Methods The effects of β-tan and Sal A on the growth of normal and neoplastic keratinocytes and on the tumor promotion-responsive JB6P + cells were determined using the MTT assay. Anchorage-independent cell growth transformation assays were used to evaluate the anti-tumor promoting properties of these SL molecules in JB6P + cells and dual luciferase reporter assays and western blot analysis were used to investigate their effects on tumor promoter-induced AP-1 and NF-κB activities and protein levels of key AP-1 and NF-кB target genes. Results β-tan and Sal A selectively inhibited tumor promoter-induced cell growth and transformation of JB6P + cells at concentrations that do not affect JB6P + and primary keratinocytes basal cell growth. In addition, both molecules reduced basal and tumor promoter-induced NF-κB transcriptional activities, differentially regulated basal and tumor promoter-induced AP-1 transcriptional activities, and modulated key players of the AP-1 and NF-κB signaling pathways. Conclusions These results highlight the anti-tumor promoting properties of β-tan and Sal A. These SL molecules isolated from two plant species native to

Sesquiterpene lactones isolated from indigenous Middle Eastern plants inhibit tumor promoter-induced transformation of JB6 cells.

Science.gov (United States)

Saikali, Melody; Ghantous, Akram; Halawi, Racha; Talhouk, Salma N; Saliba, Najat A; Darwiche, Nadine

2012-07-09

Sesquiterpene lactones (SL) are plant secondary metabolites that are known for their anti-fungal, anti-bacterial, anti-inflammatory, and anti-tumor properties. Considering that several SL-derived drugs are currently in cancer clinical trials, we have tested two SL molecules, 3-β-methoxy-iso-seco-tanapartholide (β-tan) isolated from Achillea falcata and salograviolide A (Sal A) isolated from Centaurea ainetensis, for their anti-tumor properties. We used the mouse epidermal JB6P + cells as a model for tumor promotion and cellular transformation. Key players that are involved in cellular transformation and tumorigenesis are the AP-1 and NF-κB transcription factors; therefore, we assessed how β-tan and Sal A modulate their signaling pathways in JB6P + cells. The effects of β-tan and Sal A on the growth of normal and neoplastic keratinocytes and on the tumor promotion-responsive JB6P + cells were determined using the MTT assay. Anchorage-independent cell growth transformation assays were used to evaluate the anti-tumor promoting properties of these SL molecules in JB6P + cells and dual luciferase reporter assays and western blot analysis were used to investigate their effects on tumor promoter-induced AP-1 and NF-κB activities and protein levels of key AP-1 and NF-кB target genes. β-tan and Sal A selectively inhibited tumor promoter-induced cell growth and transformation of JB6P + cells at concentrations that do not affect JB6P + and primary keratinocytes basal cell growth. In addition, both molecules reduced basal and tumor promoter-induced NF-κB transcriptional activities, differentially regulated basal and tumor promoter-induced AP-1 transcriptional activities, and modulated key players of the AP-1 and NF-κB signaling pathways. These results highlight the anti-tumor promoting properties of β-tan and Sal A. These SL molecules isolated from two plant species native to the Middle East may provide opportunities for complementary

Light induced degradation of phorbol esters.

Science.gov (United States)

Yunping, Bu; Ha, Bui Thi Ngoc; Eunice, Yeo; Chueng, Lo Loong; Yan, Hong

2012-10-01

Jatropha curcas (Jatropha) is a tropical shrub that is gaining popularity as a biofuel feedstock plant. Phorbol esters (PEs) are tetracyclic tiglian diterpenoids that are present in Jatropha seeds and other parts of plant. Epidermal cell irritating and cancer promoting PEs not only reduce commercial values of Jatropha seed cake but also cause some safety and environment concerns on PE leaching to soil. A simple bioassay of PE toxicity was conducted by incubating 48 h old brine shrimp (Artemia salina) nauplii with Jatropha oil for 24 h. 1-4% of Jatropha oil (corresponding to PE concentration of 25-100 mg L(-1)) had mortality rate of 5-95%, with LC50 estimated to be 2.7% of oil or 67 mg L(-1) of PE. Jatropha oil was incubated with clay or black soil (autoclaved or non-autoclaved) in the darkness or under sunlight for different periods of time before oil was re-extracted and tested for PE content by HPLC and for remaining toxicity with the brine shrimp bioassay. Under sunlight, PE decreased to non-detectable level within six days. Toxicity reduced to less than 5% mortality rate that is comparable to rapeseed oil control within the same period. In contrast, PE level and toxicity remained little changed when Jatropha oil was incubated in the darkness. Such PE degradation/detoxification was also found independent of the presence of soil or soil microorganisms. We conclude that sunlight directly degrades and detoxifies PEs and this finding should alleviate the concern on long term environmental impact of PE leaching. Copyright © 2012 Elsevier Inc. All rights reserved.

Senescence from glioma stem cell differentiation promotes tumor growth

International Nuclear Information System (INIS)

Ouchi, Rie; Okabe, Sachiko; Migita, Toshiro; Nakano, Ichiro; Seimiya, Hiroyuki

2016-01-01

Glioblastoma (GBM) is a lethal brain tumor composed of heterogeneous cellular populations including glioma stem cells (GSCs) and differentiated non-stem glioma cells (NSGCs). While GSCs are involved in tumor initiation and propagation, NSGCs' role remains elusive. Here, we demonstrate that NSGCs undergo senescence and secrete pro-angiogenic proteins, boosting the GSC-derived tumor formation in vivo. We used a GSC model that maintains stemness in neurospheres, but loses the stemness and differentiates into NSGCs upon serum stimulation. These NSGCs downregulated telomerase, shortened telomeres, and eventually became senescent. The senescent NSGCs released pro-angiogenic proteins, including vascular endothelial growth factors and senescence-associated interleukins, such as IL-6 and IL-8. Conditioned medium from senescent NSGCs promoted proliferation of brain microvascular endothelial cells, and mixed implantation of GSCs and senescent NSGCs into mice enhanced the tumorigenic potential of GSCs. The senescent NSGCs seem to be clinically relevant, because both clinical samples and xenografts of GBM contained tumor cells that expressed the senescence markers. Our data suggest that senescent NSGCs promote malignant progression of GBM in part via paracrine effects of the secreted proteins. - Highlights: • Non-stem glioma cells (NSGCs) lose telomerase and eventually become senescent. • Senescent NSGCs secrete pro-angiogenic proteins, such as VEGFs, IL-6, and IL-8. • Senescent NSGCs enhance the growth of brain microvascular endothelial cells. • Senescent NSGCs enhance the tumorigenic potential of glioma stem cells in vivo.

Senescence from glioma stem cell differentiation promotes tumor growth

Energy Technology Data Exchange (ETDEWEB)

Ouchi, Rie [Division of Molecular Biotherapy, Cancer Chemotherapy Center, Japanese Foundation for Cancer Research, 3-8-31 Ariake, Koto-ku, Tokyo 135-8550 (Japan); Laboratory of Molecular Target Therapy of Cancer, Department of Computational Biology and Medical Sciences, Graduate School of Frontier Sciences, The University of Tokyo, 3-8-31 Ariake, Koto-ku, Tokyo 135-8550 (Japan); Okabe, Sachiko; Migita, Toshiro [Division of Molecular Biotherapy, Cancer Chemotherapy Center, Japanese Foundation for Cancer Research, 3-8-31 Ariake, Koto-ku, Tokyo 135-8550 (Japan); Nakano, Ichiro [Department of Neurosurgery, Comprehensive Cancer Center, University of Alabama at Birmingham, 1824 6th Avenue South, Birmingham, AL 35233 (United States); Seimiya, Hiroyuki, E-mail: hseimiya@jfcr.or.jp [Division of Molecular Biotherapy, Cancer Chemotherapy Center, Japanese Foundation for Cancer Research, 3-8-31 Ariake, Koto-ku, Tokyo 135-8550 (Japan); Laboratory of Molecular Target Therapy of Cancer, Department of Computational Biology and Medical Sciences, Graduate School of Frontier Sciences, The University of Tokyo, 3-8-31 Ariake, Koto-ku, Tokyo 135-8550 (Japan)

2016-02-05

Glioblastoma (GBM) is a lethal brain tumor composed of heterogeneous cellular populations including glioma stem cells (GSCs) and differentiated non-stem glioma cells (NSGCs). While GSCs are involved in tumor initiation and propagation, NSGCs' role remains elusive. Here, we demonstrate that NSGCs undergo senescence and secrete pro-angiogenic proteins, boosting the GSC-derived tumor formation in vivo. We used a GSC model that maintains stemness in neurospheres, but loses the stemness and differentiates into NSGCs upon serum stimulation. These NSGCs downregulated telomerase, shortened telomeres, and eventually became senescent. The senescent NSGCs released pro-angiogenic proteins, including vascular endothelial growth factors and senescence-associated interleukins, such as IL-6 and IL-8. Conditioned medium from senescent NSGCs promoted proliferation of brain microvascular endothelial cells, and mixed implantation of GSCs and senescent NSGCs into mice enhanced the tumorigenic potential of GSCs. The senescent NSGCs seem to be clinically relevant, because both clinical samples and xenografts of GBM contained tumor cells that expressed the senescence markers. Our data suggest that senescent NSGCs promote malignant progression of GBM in part via paracrine effects of the secreted proteins. - Highlights: • Non-stem glioma cells (NSGCs) lose telomerase and eventually become senescent. • Senescent NSGCs secrete pro-angiogenic proteins, such as VEGFs, IL-6, and IL-8. • Senescent NSGCs enhance the growth of brain microvascular endothelial cells. • Senescent NSGCs enhance the tumorigenic potential of glioma stem cells in vivo.

Cloning of the DNA-binding subunit of human nuclear factor κB: The level of its mRNA is strongly regulated by phorbol ester or tumor necrosis factor α

International Nuclear Information System (INIS)

Meyer, R.; Hatada, E.N.; Bartsch, C.; Scheidereit, C.; Hohmann, H.P.; Haiker, M.; Roethlisberger, U.; Lahm, H.W.; Schlaeger, E.J.; van Loon, A.P.G.M.

1991-01-01

The DNA binding subunit of nuclear factor κB (NF-κB), a B-cell protein that interacts with the immunoglobulin κ light-chain gene enhancer, has been purified from nuclei of human HL-60 cells stimulated with tumor necrosis factor α (TNFα), and internal peptide sequences were obtained. Overlapping cDNA clones were isolated and sequenced. The encoded open reading frame of about 105 kDa contained at its N-terminal half all six tryptic peptide sequences, suggesting that the 51-kDa NF-κB protein is processed from a 105-kDa precursor. An in vitro synthesized protein containing most of the N-terminal half of the open reading frame bound specifically to an NF-κB binding site. This region also showed high homology to a domain shared by the Drosophila dorsal gene and the avian and mammalian rel (proto)oncogene products. The level of the 3.8-kilobase mRNA was strongly increased after stimulation with TNFα or phorbol ester. Thus, both factors not only activate NF-κB protein, as described previously, but also induce expression of the gene encoding the DNA-binding subunit of NF-κB

An AP-2 element acts synergistically with the cyclic AMP- and Phorbol ester-inducible enhancer of the human proenkephalin gene

Energy Technology Data Exchange (ETDEWEB)

Hyman, S.E.; Comb, M.; Pearlberg, J.; Goodman, H.M.

1989-01-01

An enhancer with two DNA elements, one containing the sequence CGTCA, is required for cyclic AMP-and phorbol ester-inducible transcription of the human proenkephalin gene. The authors report that an AP-2 element located adjacent to the enhancer acts synergistically with it to confer maximal response to cyclic AMP and phorbol esters.

Chrysin inhibits tumor promoter-induced MMP-9 expression by blocking AP-1 via suppression of ERK and JNK pathways in gastric cancer cells.

Directory of Open Access Journals (Sweden)

Yong Xia

Full Text Available Cell invasion is a crucial mechanism of cancer metastasis and malignancy. Matrix metalloproteinase-9 (MMP-9 is an important proteolytic enzyme involved in the cancer cell invasion process. High expression levels of MMP-9 in gastric cancer positively correlate with tumor aggressiveness and have a significant negative correlation with patients' survival times. Recently, mechanisms suppressing MMP-9 by phytochemicals have become increasingly investigated. Chrysin, a naturally occurring chemical in plants, has been reported to suppress tumor metastasis. However, the effects of chrysin on MMP-9 expression in gastric cancer have not been well studied. In the present study, we tested the effects of chrysin on MMP-9 expression in gastric cancer cells, and determined its underlying mechanism. We examined the effects of chrysin on MMP-9 expression and activity via RT-PCR, zymography, promoter study, and western blotting in human gastric cancer AGS cells. Chrysin inhibited phorbol-12-myristate 13-acetate (PMA-induced MMP-9 expression in a dose-dependent manner. Using AP-1 decoy oligodeoxynucleotides, we confirmed that AP-1 was the crucial transcriptional factor for MMP-9 expression. Chrysin blocked AP-1 via suppression of the phosphorylation of c-Jun and c-Fos through blocking the JNK1/2 and ERK1/2 pathways. Furthermore, AGS cells pretreated with PMA showed markedly enhanced invasiveness, which was partially abrogated by chrysin and MMP-9 antibody. Our results suggest that chrysin may exert at least part of its anticancer effect by controlling MMP-9 expression through suppression of AP-1 activity via a block of the JNK1/2 and ERK1/2 signaling pathways in gastric cancer AGS cells.

Radiation-induced irreparable heritable changes in cells promoting their tumoral transformation

International Nuclear Information System (INIS)

Kuzin, A.M.; Vagabova, M.Eh.; Yurov, S.S.

1988-01-01

In experiments with model plant tumors (Kalanchoe-ti plasmid Agrobat. tumefaciens C-58D) it was shown that exposure of the recepient plant to low-level γ-radiation of Gy induced changes in cells that were not repaired over two months promoting tumoral transformations in them. Those changes were shown to persist in the offspring of the exposed somatic cells

Expansion of myeloid immune suppressor Gr+CD11b+ cells in tumor-bearing host directly promotes tumor angiogenesis | Center for Cancer Research

Science.gov (United States)

We demonstrate a novel tumor-promoting role of myeloid immune suppressor Gr+CD11b+ cells, which are evident in cancer patients and tumor-bearing animals. These cells constitute approximately 5% of total cells in tumors. Tumors coinjected with Gr+CD11b+ cells exhibited increased vascular density, vascular maturation, and decreased necrosis. These immune cells produce high

CMTM5 exhibits tumor suppressor activity through promoter methylation in oral squamous cell carcinoma

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Zhang, Heyu [Central Laboratory, Peking University School of Stomatology, Beijing (China); Nan, Xu [Center for Human Disease Genomics, Department of Immunology, Key Laboratory of Medical Immunology, Ministry of Health, School of Basic Medical Sciences, Peking University, Beijing (China); Li, Xuefen [Central Laboratory, Peking University School of Stomatology, Beijing (China); Chen, Yan; Zhang, Jianyun [Department of Oral Pathology, Peking University School of Stomatology, Beijing (China); Sun, Lisha [Central Laboratory, Peking University School of Stomatology, Beijing (China); Han, Wenlin [Center for Human Disease Genomics, Department of Immunology, Key Laboratory of Medical Immunology, Ministry of Health, School of Basic Medical Sciences, Peking University, Beijing (China); Li, Tiejun, E-mail: litiejun22@vip.sina.com [Department of Oral Pathology, Peking University School of Stomatology, Beijing (China)

2014-05-02

Highlights: • Down-regulation of CMTM5 expression in OSCC tissues was found. • The promoter methylation status of CMTM5 was measured. • CMTM5-v1 inhibited cell proliferation and migration and induced apoptosis. • CMTM5 might act as a putative tumor suppressor gene in OSCC. - Abstract: Oral squamous cell carcinoma (OSCC) is one of the most common types of malignancies in the head and neck region. CKLF-like MARVEL transmembrane domain-containing member 5 (CMTM5) has been recently implicated as a tumor suppressor gene in several cancer types. Herein, we examined the expression and function of CMTM5 in oral squamous cell carcinoma. CMTM5 was down-regulated in oral squamous cell lines and tumor samples from patients with promoter methylation. Treatment with the demethylating agent 5-aza-2′-deoxycytidine restored CMTM5 expression. In the OSCC cell lines CAL27 and GNM, the ectopic expression of CMTM5-v1 strongly inhibited cell proliferation and migration and induced apoptosis. In addition, CMTM5-v1 inhibited tumor formation in vivo. Therefore, CMTM5 might act as a putative tumor suppressor gene through promoter methylation in oral squamous cell carcinoma.

CMTM5 exhibits tumor suppressor activity through promoter methylation in oral squamous cell carcinoma

International Nuclear Information System (INIS)

Zhang, Heyu; Nan, Xu; Li, Xuefen; Chen, Yan; Zhang, Jianyun; Sun, Lisha; Han, Wenlin; Li, Tiejun

2014-01-01

Highlights: • Down-regulation of CMTM5 expression in OSCC tissues was found. • The promoter methylation status of CMTM5 was measured. • CMTM5-v1 inhibited cell proliferation and migration and induced apoptosis. • CMTM5 might act as a putative tumor suppressor gene in OSCC. - Abstract: Oral squamous cell carcinoma (OSCC) is one of the most common types of malignancies in the head and neck region. CKLF-like MARVEL transmembrane domain-containing member 5 (CMTM5) has been recently implicated as a tumor suppressor gene in several cancer types. Herein, we examined the expression and function of CMTM5 in oral squamous cell carcinoma. CMTM5 was down-regulated in oral squamous cell lines and tumor samples from patients with promoter methylation. Treatment with the demethylating agent 5-aza-2′-deoxycytidine restored CMTM5 expression. In the OSCC cell lines CAL27 and GNM, the ectopic expression of CMTM5-v1 strongly inhibited cell proliferation and migration and induced apoptosis. In addition, CMTM5-v1 inhibited tumor formation in vivo. Therefore, CMTM5 might act as a putative tumor suppressor gene through promoter methylation in oral squamous cell carcinoma

CD13-positive bone marrow-derived myeloid cells promote angiogenesis, tumor growth, and metastasis.

Science.gov (United States)

Dondossola, Eleonora; Rangel, Roberto; Guzman-Rojas, Liliana; Barbu, Elena M; Hosoya, Hitomi; St John, Lisa S; Molldrem, Jeffrey J; Corti, Angelo; Sidman, Richard L; Arap, Wadih; Pasqualini, Renata

2013-12-17

Angiogenesis is fundamental to tumorigenesis and an attractive target for therapeutic intervention against cancer. We have recently demonstrated that CD13 (aminopeptidase N) expressed by nonmalignant host cells of unspecified types regulate tumor blood vessel development. Here, we compare CD13 wild-type and null bone marrow-transplanted tumor-bearing mice to show that host CD13(+) bone marrow-derived cells promote cancer progression via their effect on angiogenesis. Furthermore, we have identified CD11b(+)CD13(+) myeloid cells as the immune subpopulation directly regulating tumor blood vessel development. Finally, we show that these cells are specifically localized within the tumor microenvironment and produce proangiogenic soluble factors. Thus, CD11b(+)CD13(+) myeloid cells constitute a population of bone marrow-derived cells that promote tumor progression and metastasis and are potential candidates for the development of targeted antiangiogenic drugs.

Diet-induced obesity promotes colon tumor development in azoxymethane-treated mice.

Directory of Open Access Journals (Sweden)

Iina Tuominen

Full Text Available Obesity is an important risk factor for colon cancer in humans, and numerous studies have shown that a high fat diet enhances colon cancer development. As both increased adiposity and high fat diet can promote tumorigenesis, we examined the effect of diet-induced obesity, without ongoing high fat diet, on colon tumor development. C57BL/6J male mice were fed regular chow or high fat diet for 8 weeks. Diets were either maintained or switched resulting in four experimental groups: regular chow (R, high fat diet (H, regular chow switched to high fat diet (RH, and high fat diet switched to regular chow (HR. Mice were then administered azoxymethane to induce colon tumors. Tumor incidence and multiplicity were dramatically smaller in the R group relative to all groups that received high fat diet at any point. The effect of obesity on colon tumors could not be explained by differences in aberrant crypt foci number. Moreover, diet did not alter colonic expression of pro-inflammatory cytokines tumor necrosis factor-α, interleukin-6, interleukin-1β, and interferon-γ, which were measured immediately after azoxymethane treatment. Crypt apoptosis and proliferation, which were measured at the same time, were increased in the HR relative to all other groups. Our results suggest that factors associated with obesity - independently of ongoing high fat diet and obesity - promote tumor development because HR group animals had significantly more tumors than R group, and these mice were fed the same regular chow throughout the entire carcinogenic period. Moreover, there was no difference in the number of aberrant crypt foci between these groups, and thus the effect of obesity appears to be on subsequent stages of tumor development when early preneoplastic lesions transition into adenomas.

Extravascular red blood cells and hemoglobin promote tumor growth and therapeutic resistance as endogenous danger signals.

Science.gov (United States)

Yin, Tao; He, Sisi; Liu, Xiaoling; Jiang, Wei; Ye, Tinghong; Lin, Ziqiang; Sang, Yaxiong; Su, Chao; Wan, Yang; Shen, Guobo; Ma, Xuelei; Yu, Min; Guo, Fuchun; Liu, Yanyang; Li, Ling; Hu, Qiancheng; Wang, Yongsheng; Wei, Yuquan

2015-01-01

Hemorrhage is a common clinical manifestation in patients with cancer. Intratumor hemorrhage has been demonstrated to be a poor prognostic factor for cancer patients. In this study, we investigated the role of RBCs and hemoglobin (Hb) in the process of tumor progression and therapeutical response. RBCs and Hb potently promoted tumor cell proliferation and syngenic tumor growth. RBCs and Hb activated the reactive oxygen species-NF-κB pathway in both tumor cells and macrophages. RBCs and Hb also induced chemoresistance mediated, in part, by upregulating ABCB1 gene expression. Tumor growth induced by RBCs was accompanied by an inflammatory signature, increased tumor vasculature, and influx of M2 macrophages. In both the peritoneal cavity and tumor microenvironment, extravascular RBCs rapidly recruited monocyte-macrophages into the lesion sites. In addition, RBCs and Hb increased several nucleotide-binding oligomerization domain-like receptors' expression and induced IL-1β release. Our results provide novel insights into the protumor function of RBCs and Hb as endogenous danger signals, which can promote tumor cell proliferation, macrophage recruitment, and polarization. Hemorrhage may represent a useful prognostic factor for cancer patients because of its role in tumor promotion and chemoresistance. Copyright © 2014 by The American Association of Immunologists, Inc.

Heterogeneity of [3H]phorbol 12,13-dibutyrate binding in primary mouse keratinocytes at different stages of maturation

International Nuclear Information System (INIS)

Dunn, J.A.; Jeng, A.Y.; Yuspa, S.H.; Blumberg, P.M.

1985-01-01

Mouse keratinocytes respond heterogeneously to phorbol esters with distinct subpopulations stimulated to proliferate or induced to differentiate. The maturation state of the epidermal cell at the time of exposure may determine its response. The binding of phorbol esters to primary mouse keratinocytes was studied under culture conditions selecting for proliferating cells or differentiating cells. [20- 3 H]-12-Deoxyphorbol 13-isobutyrate ([ 3 H]-DPB) bound to both types of cells at one class of binding sites. The dissociation constant (Kd) for [ 3 H]DPB in the proliferative cells was 69 nM and the binding at saturation (Bmax) was 1.3 pmol/mg of protein. The corresponding values in the differentiative cells were 96 nM and 1.5 pmol/mg of protein, respectively. In contrast to the results obtained with [ 3 H]DPB, [20- 3 H]phorbol 12,13-dibutyrate ([ 3 H]PDBU) bound to both cell types in a heterogeneous fashion. The site for [ 3 H]DPB binding seemed to correspond to the higher affinity [ 3 H]PDBU binding site. The major difference in the cells grown in the medium containing 1.2 mM CaCl 2 was an increase in the Bmax of the lower affinity binding site with the other three parameters remaining similar. The state of epidermal differentiation thus appears to modulate the amount of the lower affinity binding sites for phorbol esters

Hypoxia promotes tumor growth in linking angiogenesis to immune escape

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Salem eCHOUAIB

2012-02-01

Full Text Available Despite the impressive progress over the past decade, in the field of tumor immunology, such as the identification of tumor antigens and antigenic peptides as potential targets, there are still many obstacles in eliciting an effective immune response to eradicate cancer. It has become increasingly clear that tumor microenvironment plays a crucial role in the control of immune protection and contains many overlapping mechanisms to evade antigen specific immunotherapy. Obviously, tumors have evolved to utilize hypoxic stress to their own advantage by activating key biochemical and cellular pathways that are important in progression, survival and metastasis. Among the hypoxia-induced genes, hypoxia-inducible factor (HIF-1 and vascular endothelial growth factor (VEGF play a determinant role in promoting tumor cell growth and survival. In this regard, hypoxia is emerging as an attractive target for cancer therapy. How the microenvironmental hypoxia poses both obstacles and opportunities for new therapeutic immune interventions will be discussed.

Quantitative promoter methylation analysis of multiple cancer-related genes in renal cell tumors

International Nuclear Information System (INIS)

Costa, Vera L; Henrique, Rui; Ribeiro, Franclim R; Pinto, Mafalda; Oliveira, Jorge; Lobo, Francisco; Teixeira, Manuel R; Jerónimo, Carmen

2007-01-01

Aberrant promoter hypermethylation of cancer-associated genes occurs frequently during carcinogenesis and may serve as a cancer biomarker. In this study we aimed at defining a quantitative gene promoter methylation panel that might identify the most prevalent types of renal cell tumors. A panel of 18 gene promoters was assessed by quantitative methylation-specific PCR (QMSP) in 85 primarily resected renal tumors representing the four major histologic subtypes (52 clear cell (ccRCC), 13 papillary (pRCC), 10 chromophobe (chRCC), and 10 oncocytomas) and 62 paired normal tissue samples. After genomic DNA isolation and sodium bisulfite modification, methylation levels were determined and correlated with standard clinicopathological parameters. Significant differences in methylation levels among the four subtypes of renal tumors were found for CDH1 (p = 0.0007), PTGS2 (p = 0.002), and RASSF1A (p = 0.0001). CDH1 hypermethylation levels were significantly higher in ccRCC compared to chRCC and oncocytoma (p = 0.00016 and p = 0.0034, respectively), whereas PTGS2 methylation levels were significantly higher in ccRCC compared to pRCC (p = 0.004). RASSF1A methylation levels were significantly higher in pRCC than in normal tissue (p = 0.035). In pRCC, CDH1 and RASSF1A methylation levels were inversely correlated with tumor stage (p = 0.031) and nuclear grade (p = 0.022), respectively. The major subtypes of renal epithelial neoplasms display differential aberrant CDH1, PTGS2, and RASSF1A promoter methylation levels. This gene panel might contribute to a more accurate discrimination among common renal tumors, improving preoperative assessment and therapeutic decision-making in patients harboring suspicious renal masses

Release of superoxide and change in morphology by neutrophils in response to phorbol esters: antagonism by inhibitors of calcium-binding proteins

Science.gov (United States)

1985-01-01

The ability of phorbol derivatives to function as stimulating agents for superoxide (O2-) release by guinea pig neutrophils has been evaluated and compared to the known ability of each compound to activate protein kinase C. Those that activate the kinase also stimulate O2- release, while those that are inactive with respect to the kinase have no effect on O2- release. The same correlation was observed with respect to the ability of phorbol esters to induce morphological changes in neutrophils, i.e., vesiculation and reduction in granule content. Certain phenothiazines and naphthalene sulfonamides that are known antagonists of calcium-binding proteins blocked both phorbol ester-induced O2- release and morphological changes in these cells. PMID:2993312

Disruption of Lysosome Function Promotes Tumor Growth and Metastasis in Drosophila *

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Chi, Congwu; Zhu, Huanhu; Han, Min; Zhuang, Yuan; Wu, Xiaohui; Xu, Tian

2010-01-01

Lysosome function is essential to many physiological processes. It has been suggested that deregulation of lysosome function could contribute to cancer. Through a genetic screen in Drosophila, we have discovered that mutations disrupting lysosomal degradation pathway components contribute to tumor development and progression. Loss-of-function mutations in the Class C vacuolar protein sorting (VPS) gene, deep orange (dor), dramatically promote tumor overgrowth and invasion of the RasV12 cells....

Specific receptors for phorbol diesters on freshly isolated human myeloid and lymphoid leukemia cells: comparable binding characteristics despite different cellular responses.

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Goodwin, B J; Moore, J O; Weinberg, J B

1984-02-01

Freshly isolated human leukemia cells have been shown in the past to display varying in vitro responses to phorbol diesters, depending on their cell type. Specific receptors for the phorbol diesters have been demonstrated on numerous different cells. This study was designed to characterize the receptors for phorbol diesters on leukemia cells freshly isolated from patients with different kinds of leukemia and to determine if differences in binding characteristics for tritium-labeled phorbol 12,13-dibutyrate (3H-PDBu) accounted for the different cellular responses elicited in vitro by phorbol diesters. Cells from 26 patients with different kinds of leukemia were studied. PDBu or phorbol 12-myristate 13-acetate (PMA) caused cells from patients with acute myeloblastic leukemia (AML), acute promyelocytic (APML), acute myelomonocytic (AMML), acute monocytic (AMoL), acute erythroleukemia (AEL), chronic myelocytic leukemia (CML) in blast crisis (myeloid), acute undifferentiated leukemia (AUL), and hairy cell leukemia (HCL) (n = 15) to adhere to plastic and spread. However, they caused no adherence or spreading and only slight aggregation of cells from patients with acute lymphocytic leukemia (ALL), chronic lymphocytic leukemia (CLL), or CML-blast crisis (lymphoid) (n = 11). All leukemia cells studied, irrespective of cellular type, displayed specific receptors for 3H-PDBu. The time courses for binding by all leukemia types were similar, with peak binding at 5-10 min at 37 degrees C and 120 min at 4 degrees C. The binding affinities were similar for patients with ALL (96 +/- 32 nM, n = 4), CLL (126 +/- 32 nM, n = 6), and acute nonlymphoid leukemia (73 +/- 14 nM, n = 11). Likewise, the numbers of specific binding sites/cell were comparable for the patients with ALL (6.2 +/- 1.3 X 10(5) sites/cell, n = 4), CLL (5.0 +/- 2.0 X 10(5) sites/cell, n = 6), and acute nonlymphoid leukemia (4.4 +/- 1.9 X 10(5) sites/cell, n = 11). Thus, the differing responses to phorbol diesters of

Transcription profile data of phorbol esters biosynthetic genes during developmental stages in Jatropha curcas.

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Jadid, Nurul; Mardika, Rizal Kharisma; Purwani, Kristanti Indah; Permatasari, Erlyta Vivi; Prasetyowati, Indah; Irawan, Mohammad Isa

2018-06-01

Jatropha curcas is currently known as an alternative source for biodiesel production. Beside its high free fatty acid content, J. curcas also contains typical diterpenoid-toxic compounds of Euphorbiaceae plant namely phorbol esters. This article present the transcription profile data of genes involved in the biosynthesis of phorbol esters at different developmental stages of leaves, fruit, and seed in Jatropha curcas . Transcriptional profiles were analyzed using reverse transcription-polymerase chain reaction (RT-PCR). We used two genes including GGPPS (Geranylgeranyl diphospate synthase), which is responsible for the formation of common diterpenoid precursor (GGPP) and CS (Casbene Synthase), which functions in the synthesis of casbene. Meanwhile, J. curcas Actin ( ACT ) was used as internal standard. We demonstrated dynamic of GGPPS and CS expression among different stage of development of leaves, fruit and seed in Jatropha .

The role of dermal irritation in the skin tumor promoting activity of petroleum middle distillates.

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Nessel, C S; Freeman, J J; Forgash, R C; McKee, R H

1999-05-01

Petroleum middle distillates (PMDs), a class of hydrocarbons which boil between 350-700 degrees F, are tumor promoters in mouse skin. The promotional activity is produced under conditions that also result in local changes, including chronic irritation and epidermal hyperplasia. The present study was conducted by comparing equal weekly doses of irritating and minimally or nonirritating test materials, to assess whether tumor promotion was a secondary response to these effects. Four PMDs, C10-C14 normal paraffins (NP), lightly refined paraffinic oil (LRPO), Jet Fuel A (JF), and steam-cracked gas oil (SCGO), were evaluated. Test materials were applied undiluted (2x/week) or as 28.6% (7x/week) or 50% (4x/week) concentrations in mineral oil for 52 weeks following initiation with dimethylbenzanthracene (DMBA). When applied undiluted, all materials produced moderate irritation and significant increase in tumor incidence. When NP, LRPO, or JF were applied in mineral oil diluent, skin irritation was generally ameliorated and few, if any, tumors were produced. SCGO was irritating and produced a significant increase in tumor frequency when administered in mineral-oil diluent. These data indicate that the promotional activity of straight-run PMDs is likely related to chronic irritation at the application site and not to dose. Thus, when used appropriately in the absence of prolonged irritation, these materials should not present a tumorigenic hazard to humans.

Quantitative promoter methylation analysis of multiple cancer-related genes in renal cell tumors

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Oliveira Jorge

2007-07-01

Full Text Available Abstract Background Aberrant promoter hypermethylation of cancer-associated genes occurs frequently during carcinogenesis and may serve as a cancer biomarker. In this study we aimed at defining a quantitative gene promoter methylation panel that might identify the most prevalent types of renal cell tumors. Methods A panel of 18 gene promoters was assessed by quantitative methylation-specific PCR (QMSP in 85 primarily resected renal tumors representing the four major histologic subtypes (52 clear cell (ccRCC, 13 papillary (pRCC, 10 chromophobe (chRCC, and 10 oncocytomas and 62 paired normal tissue samples. After genomic DNA isolation and sodium bisulfite modification, methylation levels were determined and correlated with standard clinicopathological parameters. Results Significant differences in methylation levels among the four subtypes of renal tumors were found for CDH1 (p = 0.0007, PTGS2 (p = 0.002, and RASSF1A (p = 0.0001. CDH1 hypermethylation levels were significantly higher in ccRCC compared to chRCC and oncocytoma (p = 0.00016 and p = 0.0034, respectively, whereas PTGS2 methylation levels were significantly higher in ccRCC compared to pRCC (p = 0.004. RASSF1A methylation levels were significantly higher in pRCC than in normal tissue (p = 0.035. In pRCC, CDH1 and RASSF1A methylation levels were inversely correlated with tumor stage (p = 0.031 and nuclear grade (p = 0.022, respectively. Conclusion The major subtypes of renal epithelial neoplasms display differential aberrant CDH1, PTGS2, and RASSF1A promoter methylation levels. This gene panel might contribute to a more accurate discrimination among common renal tumors, improving preoperative assessment and therapeutic decision-making in patients harboring suspicious renal masses.

Phorbol diesters and transferrin modulate lymphoblastoid cell transferrin receptor expression by two different mechanisms

International Nuclear Information System (INIS)

Alcantara, O.; Phillips, J.L.; Boldt, D.H.

1986-01-01

Expression of transferrin receptors (TfR) by activated lymphocytes is necessary for lymphocyte DNA synthesis and proliferation. Regulation of TfR expression, therefore, is a mechanism by which the lymphocyte's proliferative potential may be directed and controlled. The authors studied mechanisms by which lymphoblastoid cells modulate TfR expression during treatment with phorbol diesters or iron transferrin (FeTf), agents which cause downregulation of cell surface TfR. Phorbol diester-induced TfR downregulation occurred rapidly, being detectable at 2 min and reaching maximal decreases of 50% by 15 min. It was inhibited by cold but not by agents that destabilize cytoskeletal elements. Furthermore, this downregulation was reversed rapidly by washing or by treatment with the membrane interactive agent, chlorpromazine. In contrast, FeTf-induced TfR downregulation occurred slowly. Decreased expression of TfR was detectable only after 15 min and maximal downregulation was achieved after 60 min. Although FeTf-induced downregulation also was inhibited by cold, it was inhibited in addition by a group of microtubule destabilizing agents (colchicine, vinblastine, podophyllotoxin) or cytochalasin B, a microfilament inhibitor. Furthermore, FeTf-induced downregulation was not reversed readily by washing or by treatment with chlorpromazine. Phorbol diesters cause TfR downregulation by a cytoskeleton-independent mechanism. These data indicate that TfR expression is regulated by two independent mechanisms in lymphoblastoid cells, and they provide the possibility that downregulation of TfR by different mechanisms may result in different effects in these cells

Tumor-associated endothelial cells display GSTP1 and RARβ2 promoter methylation in human prostate cancer

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Pohida Thomas J

2006-03-01

Full Text Available Abstract Background A functional blood supply is essential for tumor growth and proliferation. However, the mechanism of blood vessel recruitment to the tumor is still poorly understood. Ideally, a thorough molecular assessment of blood vessel cells would be critical in our comprehension of this process. Yet, to date, there is little known about the molecular makeup of the endothelial cells of tumor-associated blood vessels, due in part to the difficulty of isolating a pure population of endothelial cells from the heterogeneous tissue environment. Methods Here we describe the use of a recently developed technique, Expression Microdissection, to isolate endothelial cells from the tumor microenvironment. The methylation status of the dissected samples was evaluated for GSTP1 and RARβ2 promoters via the QMS-PCR method. Results Comparing GSTP1 and RARβ2 promoter methylation data, we show that 100% and 88% methylation is detected, respectively, in the tumor areas, both in epithelium and endothelium. Little to no methylation is observed in non-tumor tissue areas. Conclusion We applied an accurate microdissection technique to isolate endothelial cells from tissues, enabling DNA analysis such as promoter methylation status. The observations suggest that epigenetic alterations may play a role in determining the phenotype of tumor-associated vasculature.

White Adipose Tissue Cells Are Recruited by Experimental Tumors and Promote Cancer Progression in Mouse Models

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Zhang, Yan; Daquinag, Alexes; Traktuev, Dmitry O.; Amaya-Manzanares, Felipe; Simmons, Paul J.; March, Keith L.; Pasqualini, Renata; Arap, Wadih; Kolonin, Mikhail G.

2010-01-01

The connection between obesity and accelerated cancer progression has been established, but the mediating mechanisms are not well understood. We have shown that stromal cells from white adipose tissue (WAT) cooperate with the endothelium to promote blood vessel formation through the secretion of soluble trophic factors. Here, we hypothesize that WAT directly mediates cancer progression by serving as a source of cells that migrate to tumors and promote neovascularization. To test this hypothesis, we have evaluated the recruitment of WAT-derived cells by tumors and the effect of their engraftment on tumor growth by integrating a transgenic mouse strain engineered for expansion of traceable cells with established allograft and xenograft cancer models. Our studies show that entry of adipose stromal and endothelial cells into systemic circulation leads to their homing to and engraftment into tumor stroma and vasculature, respectively. We show that recruitment of adipose stromal cells by tumors is sufficient to promote tumor growth. Finally, we show that migration of stromal and vascular progenitor cells from WAT grafts to tumors is also associated with acceleration of cancer progression. These results provide a biological insight for the clinical association between obesity and cancer, thus outlining potential avenues for preventive and therapeutic strategies. PMID:19491274

Tumor associated CD70 expression is involved in promoting tumor migration and macrophage infiltration in GBM.

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Ge, Haitao; Mu, Luyan; Jin, Linchun; Yang, Changlin; Chang, Yifan Emily; Long, Yu; DeLeon, Gabriel; Deleyrolle, Loic; Mitchell, Duane A; Kubilis, Paul S; Lu, Dunyue; Qi, Jiping; Gu, Yunhe; Lin, Zhiguo; Huang, Jianping

2017-10-01

Tumor migration/metastasis and immunosuppression are major obstacles in effective cancer therapy. Incidentally, these 2 hurdles usually coexist inside tumors, therefore making therapy significantly more complicated, as both oncogenic mechanisms must be addressed for successful therapeutic intervention. Our recent report highlights that the tumor expression of a TNF family member, CD70, is correlated with poor survival for primary gliomas. In this study, we investigated how CD70 expression by GBM affects the characteristics of tumor cells and the tumor microenvironment. We found that the ablation of CD70 in primary GBM decreased CD44 and SOX2 gene expression, and inhibited tumor migration, growth and the ability to attract monocyte-derived M2 macrophages in vitro. In the tumor microenvironment, CD70 was associated with immune cell infiltrates, such as T cells; myeloid-derived suppressor cells; and monocytes/macrophages based on the RNA-sequencing profile. The CD163+ macrophages were far more abundant than T cells were. This overwhelming level of macrophages was identified only in GBM and not in low-grade gliomas and normal brain specimens, implying their tumor association. CD70 was detected only on tumor cells, not on macrophages, and was highly correlated with CD163 gene expression in primary GBM. Additionally, the co-expression of the CD70 and CD163 genes was found to correlate with decreased survival for patients with primary GBM. Together, these data suggest that CD70 expression is involved in promoting tumor aggressiveness and immunosuppression via tumor-associated macrophage recruitment/activation. Our current efforts to target this molecule using chimeric antigen receptor T cells hold great potential for treating patients with GBM. © 2017 UICC.

The role of chronic acanthosis and subacute inflammation in tumor promotion in CD-1 mice by petroleum middle distillates.

Science.gov (United States)

Skisak, C

1991-07-01

An initiation-promotion bioassay using CD-1 mice was conducted to examine the role of chronic acanthosis and inflammation in tumor promotion by petroleum middle distillates (MD). Test groups were initiated with 7,12-dimethylbenz[a]anthracene (DMBA). Promotion with MD consisted of twice weekly treatments for 25 weeks with either 25 or 50 microliters, 50 microliters + daily treatment with 15 micrograms dexamethasone, 50 microliters + postapplication washings, or 100 microliters. Three mice from each group were euthanized at 21-day intervals (24 total per group). The skin from interim euthanized mice was examined histopathologically for tumors, acanthosis, and subacute inflammation. Tumor incidence at study termination was as follows: 25 microliters (45%), 50 microliters (43%), 50 microliters + dexamethasone (0%), 50 microliters + washing (70%), and 100 microliters (81%). A correlation of greater than 0.93 was observed at all intervals between tumor incidence and cumulative group mean degrees of acanthosis in interim euthanized mice. The correlation between subacute inflammation at early through midstudy interval weeks and tumor incidence at study termination was poor. These results support the hypothesis that induction of a lasting, albeit mild, hyperplasia is an essential, but not sufficient requirement for tumor promotion. Furthermore, subacute inflammation does not appear to be a significant factor in tumor promotion by petroleum MD.

Primary Tr1 cells from metastatic melanoma eliminate tumor-promoting macrophages through granzyme B- and perforin-dependent mechanisms.

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Yan, Hongxia; Zhang, Ping; Kong, Xue; Hou, Xianglian; Zhao, Li; Li, Tianhang; Yuan, Xiaozhou; Fu, Hongjun

2017-04-01

In malignant melanoma, tumor-associated macrophages play multiple roles in promoting tumor growth, such as inducing the transformation of melanocytes under ultraviolet irradiation, increasing angiogenesis in melanomas, and suppressing antitumor immunity. Because granzyme B- and perforin-expressing Tr1 cells could specifically eliminate antigen-presenting cells of myeloid origin, we examined whether Tr1 cells in melanoma could eliminate tumor-promoting macrophages and how the interaction between Tr1 cells and macrophages could affect the growth of melanoma cells. Tr1 cells were characterized by high interleukin 10 secretion and low Foxp3 expression and were enriched in the CD4 + CD49b + LAG-3 + T-cell fraction. Macrophages derived from peripheral blood monocytes in the presence of modified melanoma-conditioned media demonstrated tumor-promoting capacity, exemplified by improving the proliferation of cocultured A375 malignant melanoma cells. But when primary Tr1 cells were present in the macrophage-A375 coculture, the growth of A375 cells was abrogated. The conventional CD25 + Treg cells, however, were unable to inhibit macrophage-mediated increase in tumor cell growth. Further analyses showed that Tr1 cells did not directly eliminate A375 cells, but mediated the killing of tumor-promoting macrophages through the secretion of granzyme B and perforin. The tumor-infiltrating interleukin 10 + Foxp3 - CD4 + T cells expressed very low levels of granzyme B and perforin, possibly suggested the downregulation of Tr1 cytotoxic capacity in melanoma tumors. Together, these data demonstrated an antitumor function of Tr1 cells through the elimination of tumor-promoting macrophages, which was not shared by conventional Tregs.

Disruption of lysosome function promotes tumor growth and metastasis in Drosophila.

Science.gov (United States)

Chi, Congwu; Zhu, Huanhu; Han, Min; Zhuang, Yuan; Wu, Xiaohui; Xu, Tian

2010-07-09

Lysosome function is essential to many physiological processes. It has been suggested that deregulation of lysosome function could contribute to cancer. Through a genetic screen in Drosophila, we have discovered that mutations disrupting lysosomal degradation pathway components contribute to tumor development and progression. Loss-of-function mutations in the Class C vacuolar protein sorting (VPS) gene, deep orange (dor), dramatically promote tumor overgrowth and invasion of the Ras(V12) cells. Knocking down either of the two other components of the Class C VPS complex, carnation (car) and vps16A, also renders Ras(V12) cells capable for uncontrolled growth and metastatic behavior. Finally, chemical disruption of the lysosomal function by feeding animals with antimalarial drugs, chloroquine or monensin, leads to malignant tumor growth of the Ras(V12) cells. Taken together, our data provide evidence for a causative role of lysosome dysfunction in tumor growth and invasion and indicate that members of the Class C VPS complex behave as tumor suppressors.

Cancer associated fibroblasts promote tumor growth and metastasis by modulating the tumor immune microenvironment in a 4T1 murine breast cancer model.

Directory of Open Access Journals (Sweden)

Debbie Liao

2009-11-01

Full Text Available Local inflammation associated with solid tumors commonly results from factors released by tumor cells and the tumor stroma, and promotes tumor progression. Cancer associated fibroblasts comprise a majority of the cells found in tumor stroma and are appealing targets for cancer therapy. Here, our aim was to determine the efficacy of targeting cancer associated fibroblasts for the treatment of metastatic breast cancer.We demonstrate that cancer associated fibroblasts are key modulators of immune polarization in the tumor microenvironment of a 4T1 murine model of metastatic breast cancer. Elimination of cancer associated fibroblasts in vivo by a DNA vaccine targeted to fibroblast activation protein results in a shift of the immune microenvironment from a Th2 to Th1 polarization. This shift is characterized by increased protein expression of IL-2 and IL-7, suppressed recruitment of tumor-associated macrophages, myeloid derived suppressor cells, T regulatory cells, and decreased tumor angiogenesis and lymphangiogenesis. Additionally, the vaccine improved anti-metastatic effects of doxorubicin chemotherapy and enhanced suppression of IL-6 and IL-4 protein expression while increasing recruitment of dendritic cells and CD8(+ T cells. Treatment with the combination therapy also reduced tumor-associated Vegf, Pdgfc, and GM-CSF mRNA and protein expression.Our findings demonstrate that cancer associated fibroblasts promote tumor growth and metastasis through their role as key modulators of immune polarization in the tumor microenvironment and are valid targets for therapy of metastatic breast cancer.

Cancer associated fibroblasts promote tumor growth and metastasis by modulating the tumor immune microenvironment in a 4T1 murine breast cancer model.

Science.gov (United States)

Liao, Debbie; Luo, Yunping; Markowitz, Dorothy; Xiang, Rong; Reisfeld, Ralph A

2009-11-23

Local inflammation associated with solid tumors commonly results from factors released by tumor cells and the tumor stroma, and promotes tumor progression. Cancer associated fibroblasts comprise a majority of the cells found in tumor stroma and are appealing targets for cancer therapy. Here, our aim was to determine the efficacy of targeting cancer associated fibroblasts for the treatment of metastatic breast cancer. We demonstrate that cancer associated fibroblasts are key modulators of immune polarization in the tumor microenvironment of a 4T1 murine model of metastatic breast cancer. Elimination of cancer associated fibroblasts in vivo by a DNA vaccine targeted to fibroblast activation protein results in a shift of the immune microenvironment from a Th2 to Th1 polarization. This shift is characterized by increased protein expression of IL-2 and IL-7, suppressed recruitment of tumor-associated macrophages, myeloid derived suppressor cells, T regulatory cells, and decreased tumor angiogenesis and lymphangiogenesis. Additionally, the vaccine improved anti-metastatic effects of doxorubicin chemotherapy and enhanced suppression of IL-6 and IL-4 protein expression while increasing recruitment of dendritic cells and CD8(+) T cells. Treatment with the combination therapy also reduced tumor-associated Vegf, Pdgfc, and GM-CSF mRNA and protein expression. Our findings demonstrate that cancer associated fibroblasts promote tumor growth and metastasis through their role as key modulators of immune polarization in the tumor microenvironment and are valid targets for therapy of metastatic breast cancer.

The progress of tumor gene-radiotherapy induced by Egr-1 promoter

International Nuclear Information System (INIS)

Guo Rui; Li Biao

2010-01-01

The promoter of early growth response gene-1 (Egr-1) is a cis-acting element of Egr-1, and its activity is regulated by inducers such as ionizing radiation, free radical. In designated gene-radiotherapy system, radiation combined with therapeutic gene (such as tumor necrosis factor-α gene, suicide gene) can spatially and temporally regulate therapeutic gene expression in the irradiated field, produced a marked effect, while little systemic toxicities were observed. The combination of radiotherapy and gene therapy is promising in tumor therapy. (authors)

Induction of rat hepatic zinc thionein by phorbol ester-mediated protein kinase C pathway

Energy Technology Data Exchange (ETDEWEB)

Garrett, S.H.; Funk, A.E.; Brady, F.O.

1986-05-01

Metallothionein (MT) exists in rat liver mainly as a zinc protein. The levels of this protein fluctuate in response to a variety of internal and external stimuli. Among these inducers of MT are metals, glucocorticoids, catecholamines, and polypeptide hormones. Metals and glucocorticoids are primary inducers of MT, while the others operate either via adenylate cyclase/cAMP/cAMP-dependent protein kinase, or via phospholipase C/inositol 1,4,5-triphosphate, diacylglycerol/Ca/sup 2 +/-dependent protein kinase, protein kinase C. The authors have examined the role of the protein kinase C pathway in the induction of MT by using a phorbol ester, 12-O-tetradecanoyl-phorbol 13-acetate (TPA), to activate it. In vivo TPA is a good inducer of Zn/sub 7/-MT with an ED/sub 0.5/ of 26.5 nmoles/kg b.w. Maximal levels reached were about 7..mu..g Zn in MT/g liver, an induction increase of 8 to 10-fold. An inactive compound, 4..beta..-phorbol, and the vehicle (DMSO) did not stimulate the synthesis of Zn/sub 7/-MT. This induction by TPA requires de novo protein synthesis, as demonstrated by a cycloheximide/(/sup 35/S)-cysteine experiment. TPA stimulated Zn incorporation by 8.6-fold and (/sup 35/S)-cysteine incorporation by 4.8-fold during an 11h induction. These increases were blocked 100% by treatment with cycloheximide at -1 and +5h. These experiments have been repeated in cultured hepatocytes, using (/sup 35/S)-cysteine incorporation, slab SDS-PAGE, and autoradiography to quantitate MT levels.

Activities of Jatropha curcas phorbol esters in various bioassays.

Science.gov (United States)

Devappa, Rakshit K; Rajesh, Sanjay K; Kumar, Vikas; Makkar, Harinder P S; Becker, Klaus

2012-04-01

Jatropha curcas seeds contain 30-35% oil, which can be converted to high quality biodiesel. However, Jatropha oil is toxic, ascribed to the presence of phorbol esters (PEs). In this study, isolated phorbol ester rich fraction (PEEF) was used to evaluate the activity of PEs using three aquatic species based bioassays (snail (Physa fontinalis), brine shrimp (Artemeia salina), daphnia (Daphnia magna)) and microorganisms. In all the bioassays tested, increase in concentration of PEs increased mortality with an EC(50) (48 h) of 0.33, 26.48 and 0.95 mg L(-1) PEs for snail, artemia and daphnia, respectively. The sensitivity of various microorganisms for PEs was also tested. Among the bacterial species tested, Streptococcus pyogenes and Proteus mirabilis were highly susceptible with a minimum inhibitory concentration (MIC) of 215 mg L(-1) PEs; and Pseudomonas putida were also sensitive with MIC of 251 mg L(-1) PEs. Similarly, Fusarium species of fungi exhibited EC(50) of 58 mg L(-1) PEs, while Aspergillus niger and Curvularia lunata had EC(50) of 70 mg L(-1). The snail bioassay was most sensitive with 100% snail mortality at 1 μg of PEs mL(-1). In conclusion, snail bioassay could be used to monitor PEs in Jatropha derived products such as oil, biodiesel, fatty acid distillate, kernel meal, cake, glycerol or for contamination in soil or other environmental matrices. In addition, PEs with molluscicidal/antimicrobial activities could be utilized for agricultural and pharmaceutical applications. Copyright © 2011 Elsevier Inc. All rights reserved.

Experimental assessment of toxic phorbol ester in oil, biodiesel and seed cake of Jatropha curcas and use of biodiesel in diesel engine

International Nuclear Information System (INIS)

Prasad, Lalit; Pradhan, Subhalaxmi; Das, L.M.; Naik, S.N.

2012-01-01

Highlights: ► In the present study toxic phorbol esters were detected in oil and seed cake of Jatropha curcas but not detected in biodiesel using high performance liquid chromatography (HPLC). ► The quantity of phorbol esters in Jatropha curcas oil and cake were amounted to be 2.12 ± 0.02 mg/g and 0.6 ± 0.01 mg/g respectively. ► As jatropha oil is a potential source for biodiesel preparation, huge amount of oil and cake will be generated and hence need to be handled carefully. ► Upon engine study exhaust pollutant such as hydrocarbon, smoke opacity and carbon monoxide reduced substantially. - Abstract: The present study deals with estimation of toxic phorbol esters in Jatropha curcas oil, cake and biodiesel and performance emission of different blends of biodiesel in diesel engine. The jatropha seed was collected from Chattishgarh, India and oil content of the seed kernel was 56.5%, determined by soxhlet apparatus. The oil was subjected to biodiesel preparation by twin step method of acid esterification followed by alkali transesterification. The total conversion of jatropha oil methyl ester (JOME) after reaction was 96.05% from proton nuclear magnetic resonance ( 1 H NMR) studies. The phorbol esters content of oil, cake and biodiesel was determined by high performance liquid chromatography (HPLC, Waters). The phorbol esters content of the oil was more (2.26 ± 0.01 mg/g) than the cake (0.6 ± 0.01 mg/g) but no phorbol esters peak was detected in biodiesel. The performance and emission study of the fuel blends (JB2, JB5 and JB10) with conventional diesel were tested for their use as substitute fuel for a single cylinder direct injection diesel engine at constant speed (1500 rpm). The emissions such as CO, HC and smoke opacity decreased whereas NO x and BSCF increased with biodiesel blends.

Gain-of-function mutant p53 activates small GTPase Rac1 through SUMOylation to promote tumor progression.

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Yue, Xuetian; Zhang, Cen; Zhao, Yuhan; Liu, Juan; Lin, Alan W; Tan, Victor M; Drake, Justin M; Liu, Lianxin; Boateng, Michael N; Li, Jun; Feng, Zhaohui; Hu, Wenwei

2017-08-15

Tumor suppressor p53 is frequently mutated in human cancer. Mutant p53 often promotes tumor progression through gain-of-function (GOF) mechanisms. However, the mechanisms underlying mutant p53 GOF are not well understood. In this study, we found that mutant p53 activates small GTPase Rac1 as a critical mechanism for mutant p53 GOF to promote tumor progression. Mechanistically, mutant p53 interacts with Rac1 and inhibits its interaction with SUMO-specific protease 1 (SENP1), which in turn inhibits SENP1-mediated de-SUMOylation of Rac1 to activate Rac1. Targeting Rac1 signaling by RNAi, expression of the dominant-negative Rac1 (Rac1 DN), or the specific Rac1 inhibitor NSC23766 greatly inhibits mutant p53 GOF in promoting tumor growth and metastasis. Furthermore, mutant p53 expression is associated with enhanced Rac1 activity in clinical tumor samples. These results uncover a new mechanism for Rac1 activation in tumors and, most importantly, reveal that activation of Rac1 is an unidentified and critical mechanism for mutant p53 GOF in tumorigenesis, which could be targeted for therapy in tumors containing mutant p53. © 2017 Yue et al.; Published by Cold Spring Harbor Laboratory Press.

Rab11 is phosphorylated by classical and novel protein kinase C isoenzymes upon sustained phorbol ester activation.

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Pavarotti, Martín; Capmany, Anahí; Vitale, Nicolas; Colombo, María Isabel; Damiani, María Teresa

2012-02-01

Rab11 is a small GTPase that controls diverse intracellular trafficking pathways. However, the molecular machinery that regulates the participation of Rab11 in those different transport events is poorly understood. In resting cells, Rab11 localizes at the endocytic recycling compartment (ERC), whereas the different protein kinase C (PKC) isoforms display a cytosolic distribution. Sustained phorbol ester stimulation induces the translocation of the classical PKCα and PKCβII isoenzymes to the ERC enriched in Rab11, and results in transferrin recycling inhibition. In contrast, novel PKCε and atypical PKCζ isoenzymes neither redistribute to the perinucleus nor modify transferrin recycling transport after phorbol ester stimulation. Although several Rabs have been shown to be phosphorylated, there is to date no evidence indicating Rab11 as a kinase substrate. In this report, we show that Rab11 appears phosphorylated in vivo in phorbol ester-stimulated cells. A bioinformatic analysis of Rab11 allowed us to identify several high-probability Ser/Thr kinase phosphorylation sites. Our results demonstrate that classical PKC (PKCα and PKCβII but not PKCβI) directly phosphorylate Rab11 in vitro. In addition, novel PKCε and PKCη but not PKCδ isoenzymes also phosphorylate Rab11. Mass spectrometry analysis revealed that Ser 177 is the Rab11 residue to be phosphorylated in vitro by either PKCβII or PKCε. In agreement, the phosphomimetic mutant, Rab11 S177D, retains transferrin at the ERC in the absence of phorbol-12-myristate-13-acetate stimulus. This report shows for the first time that Rab11 is differentially phosphorylated by distinct PKC isoenzymes and that this post-translational modification might be a regulatory mechanism of intracellular trafficking. Copyright © 2012 Soçiété Francaise des Microscopies and Société de Biologie Cellulaire de France.

Phorbol ester induced phosphorylation of the estrogen receptor in intact MCF-7 human breast cancer cells

International Nuclear Information System (INIS)

Knabbe, C.; Lippman, M.E.; Greene, G.L.; Dickson, R.B.

1986-01-01

Recent studies with a variety of cellular receptors have shown that phorbol ester induced phosphorylation modulates ligand binding and function. In this study the authors present direct evidence that the estrogen receptor in MCF-7 human breast cancer cells is a phosphoprotein whose phosphorylation state can be enhanced specifically by phorbol-12-myristate-13-acetate (PMA). Cells were cultured to 6h in the presence of [ 32 P]-orthophosphate. Whole cell extracts were immunoprecipitated with a monoclonal antibody (D58) against the estrogen receptor and subjected to SDS-polyacrylamide electrophoresis. Autoradiography showed a specific band in the region of 60-62 kDa which was significantly increased in preparations from PMA treated cells. Phospho-amino acid analysis demonstrated specific phosphorylation of serine and threonine residues. Cholera toxin or forskolin did not change the phosphorylation state of this protein. In a parallel binding analysis PMA led to a rapid decrease of estrogen binding sites. The estrogen induction of both progesterone receptors and growth in semisolid medium was blocked by PMA, whereas the estrogen induction of the 8kDa protein corresponding to the ps2 gene product and of the 52 kDa protein was not affected. In conclusion, phorbol esters can induce phosphorylation of the estrogen receptor. This process may be associated with the inactivation of certain receptor functions

β-elemene inhibits tumor-promoting effect of M2 macrophages in lung cancer.

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Yu, Xiaomu; Xu, Maoyi; Li, Na; Li, Zongjuan; Li, Hongye; Shao, Shujuan; Zou, Kun; Zou, Lijuan

2017-08-19

Macrophages in tumor are mostly M2-polarized and have been reported to promote tumorigenesis, which are also defined as tumor-associated macrophages (TAMs). β-elemene has therapeutic effects against several cancers, however, it remains unknown whether β-elemene could inhibit cancer by targeting TAMs. Herein, we examined the effect of β-elemene on macrophages to elucidate a novel mechanism of β-elemene in tumor therapy. We showed that the conditioned medium of M2 macrophages promoted lung cancer cells to migration, invasion and epithelial mesenchymal transition, which could be inhibited by β-elemene. Moreover, β-elemene regulated the polarization of macrophages from M2 to M1. β-elemene also inhibited the proliferation, migration, invasion of lung cancer cells and enhanced its radiosensitivity. These results indicate β-elemene suppresses lung cancer by regulating both macrophages and lung cancer cells, it is a promising drug for combination with chemotherapy or radiotherapy. Copyright © 2017 Elsevier Inc. All rights reserved.

MicroRNA-96 Promotes Tumor Invasion in Colorectal Cancer via RECK.

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Iseki, Yasuhito; Shibutani, Masatsune; Maeda, Kiyoshi; Nagahara, Hisashi; Fukuoka, Tatsunari; Matsutani, Shinji; Hirakawa, Kosei; Ohira, Masaichi

2018-04-01

miR-96 is reported to inhibit reversion cysteine-rich Kazal motif (RECK), which is associated with tumor invasion, in solid cancer types (e.g. breast cancer, non-small cell lung cancer, esophageal cancer). The purpose of this study is to clarify whether miR-96 is similarly associated with tumor invasion in colorectal cancer. We performed western blotting to investigate the expression of RECK when miR-96 mimics or inhibitors were transferred into HCT-116 colorectal cancer cells. The RECK mRNA level was assessed by a reverse transcription polymerase chain reaction. An invasion assay was used to evaluate tumor invasion. The expression of RECK was inhibited by the transfection of miR-96 mimics. RECK mRNA level was reduced by miR-96 mimics and increased by miR-96 inhibitor. In the invasion assay, miR-96 mimics were shown to promote tumor invasion. miR-96 may be associated with tumor invasion through inhibition of RECK expression in colorectal cancer. Copyright© 2018, International Institute of Anticancer Research (Dr. George J. Delinasios), All rights reserved.

Noradrenaline, oxymetazoline and phorbol myristate acetate induce distinct functional actions and phosphorylation patterns of α1A-adrenergic receptors.

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Alcántara-Hernández, Rocío; Hernández-Méndez, Aurelio; Romero-Ávila, M Teresa; Alfonzo-Méndez, Marco A; Pupo, André S; García-Sáinz, J Adolfo

2017-12-01

In LNCaP cells that stably express α 1A -adrenergic receptors, oxymetazoline increased intracellular calcium and receptor phosphorylation, however, this agonist was a weak partial agonist, as compared to noradrenaline, for calcium signaling. Interestingly, oxymetazoline-induced receptor internalization and desensitization displayed greater effects than those induced by noradrenaline. Phorbol myristate acetate induced modest receptor internalization and minimal desensitization. α 1A -Adrenergic receptor interaction with β-arrestins (colocalization/coimmunoprecipitation) was induced by noradrenaline and oxymetazoline and, to a lesser extent, by phorbol myristate acetate. Oxymetazoline was more potent and effective than noradrenaline in inducing ERK 1/2 phosphorylation. Mass spectrometric analysis of immunopurified α 1A -adrenergic receptors from cells treated with adrenergic agonists and the phorbol ester clearly showed that phosphorylated residues were present both at the third intracellular loop and at the carboxyl tail. Distinct phosphorylation patterns were observed under the different conditions. The phosphorylated residues were: a) Baseline and all treatments: T233; b) noradrenaline: S220, S227, S229, S246, S250, S389; c) oxymetazoline: S227, S246, S381, T384, S389; and d) phorbol myristate acetate: S246, S250, S258, S351, S352, S401, S402, S407, T411, S413, T451. Our novel data, describing the α 1A -AR phosphorylation sites, suggest that the observed different phosphorylation patterns may participate in defining adrenoceptor localization and action, under the different conditions examined. Copyright © 2017 Elsevier B.V. All rights reserved.

Tumor associated osteoclast-like giant cells promote tumor growth and lymphangiogenesis by secreting vascular endothelial growth factor-C

International Nuclear Information System (INIS)

Hatano, Yu; Nakahama, Ken-ichi; Isobe, Mitsuaki; Morita, Ikuo

2014-01-01

findings revealed that OGCs in the tumor environment promoted tumor growth and lymphangiogenesis, at least in part, by secreting VEGF-C

NF-κB RelA renders tumor-associated macrophages resistant to and capable of directly suppressing CD8+ T cells for tumor promotion.

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Li, Liwen; Han, Lei; Sun, Fan; Zhou, Jingjiao; Ohaegbulam, Kim C; Tang, Xudong; Zang, Xingxing; Steinbrecher, Kris A; Qu, Zhaoxia; Xiao, Gutian

2018-01-01

Activation of the inflammatory transcription factor NF-κB in tumor-associated macrophages (TAMs) is assumed to contribute to tumor promotion. However, whether and how NF-κB drives the antitumor macrophages to become pro-tumorigenic have not been determined in any cancer type yet. Similarly, how TAMs repress CD8 + cytotoxic T lymphocytes (CTLs) remains largely unknown, although their importance in regulatory T (Treg) cell regulation and tumor promotion has been well appreciated. Here, using an endogenous lung cancer model we uncover a direct crosstalk between TAMs and CTLs. TAMs suppress CTLs through the T-cell inhibitory molecule B7x (B7-H4/B7S1) in a cell-cell contact manner, whereas CTLs kill TAMs in a tumor antigen-specific manner. Remarkably, TAMs secrete the known T-cell suppressive cytokine interleukin-10 (IL-10) to activate, but not to repress, CTLs. Notably, one major role of cell-intrinsic NF-κB RelA is to drive TAMs to suppress CTLs for tumor promotion. It induces B7x expression in TAMs directly, and restricts IL-10 expression indirectly by repressing expression of the NF-κB cofactor Bcl3 and subsequent Bcl3/NF-κB1-mediated transcription of IL-10. It also renders TAMs resistant to CTLs by up-regulating anti-apoptotic genes. These studies help understand how immunity is shaped in lung tumorigenesis, and suggest a RelA-targeted immunotherapy for this deadliest cancer.

The Innate Immune Receptor NLRX1 Functions as a Tumor Suppressor by Reducing Colon Tumorigenesis and Key Tumor-Promoting Signals

Directory of Open Access Journals (Sweden)

A. Alicia Koblansky

2016-03-01

Full Text Available NOD-like receptor (NLR proteins are intracellular innate immune sensors/receptors that regulate immunity. This work shows that NLRX1 serves as a tumor suppressor in colitis-associated cancer (CAC and sporadic colon cancer by keeping key tumor promoting pathways in check. Nlrx1−/− mice were highly susceptible to CAC, showing increases in key cancer-promoting pathways including nuclear factor κB (NF-κB, mitogen-activated protein kinase (MAPK, signal transducer and activator of transcription 3 (STAT3, and interleukin 6 (IL-6. The tumor-suppressive function of NLRX1 originated primarily from the non-hematopoietic compartment. This prompted an analysis of NLRX1 function in the Apcmin/+ genetic model of sporadic gastrointestinal cancer. NLRX1 attenuated Apcmin/+ colon tumorigenesis, cellular proliferation, NF-κB, MAPK, STAT3 activation, and IL-6 levels. Application of anti-interleukin 6 receptor (IL6R antibody therapy reduced tumor burden, increased survival, and reduced STAT3 activation in Nlrx1−/−Apcmin/+ mice. As an important clinical correlate, human colon cancer samples expressed lower levels of NLRX1 than healthy controls in multiple patient cohorts. These data implicate anti-IL6R as a potential personalized therapy for colon cancers with reduced NLRX1.

S100A9 interaction with TLR4 promotes tumor growth.

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Eva Källberg

Full Text Available By breeding TRAMP mice with S100A9 knock-out (S100A9(-/- animals and scoring the appearance of palpable tumors we observed a delayed tumor growth in animals devoid of S100A9 expression. CD11b(+ S100A9 expressing cells were not observed in normal prostate tissue from control C57BL/6 mice but were readily detected in TRAMP prostate tumors. Also, S100A9 expression was observed in association with CD68(+ macrophages in biopsies from human prostate tumors. Delayed growth of TRAMP tumors was also observed in mice lacking the S100A9 ligand TLR4. In the EL-4 lymphoma model tumor growth inhibition was observed in S100A9(-/- and TLR4(-/-, but not in RAGE(-/- animals lacking an alternative S100A9 receptor. When expression of immune-regulating genes was analyzed using RT-PCR the only common change observed in mice lacking S100A9 and TLR4 was a down-regulation of TGFβ expression in splenic CD11b(+ cells. Lastly, treatment of mice with a small molecule (ABR-215050 that inhibits S100A9 binding to TLR4 inhibited EL4 tumor growth. Thus, S100A9 and TLR4 appear to be involved in promoting tumor growth in two different tumor models and pharmacological inhibition of S100A9-TLR4 interactions is a novel and promising target for anti-tumor therapies.

S100A9 Interaction with TLR4 Promotes Tumor Growth

Science.gov (United States)

Källberg, Eva; Vogl, Thomas; Liberg, David; Olsson, Anders; Björk, Per; Wikström, Pernilla; Bergh, Anders; Roth, Johannes; Ivars, Fredrik; Leanderson, Tomas

2012-01-01

By breeding TRAMP mice with S100A9 knock-out (S100A9−/−) animals and scoring the appearance of palpable tumors we observed a delayed tumor growth in animals devoid of S100A9 expression. CD11b+ S100A9 expressing cells were not observed in normal prostate tissue from control C57BL/6 mice but were readily detected in TRAMP prostate tumors. Also, S100A9 expression was observed in association with CD68+ macrophages in biopsies from human prostate tumors. Delayed growth of TRAMP tumors was also observed in mice lacking the S100A9 ligand TLR4. In the EL-4 lymphoma model tumor growth inhibition was observed in S100A9−/− and TLR4−/−, but not in RAGE−/− animals lacking an alternative S100A9 receptor. When expression of immune-regulating genes was analyzed using RT-PCR the only common change observed in mice lacking S100A9 and TLR4 was a down-regulation of TGFβ expression in splenic CD11b+ cells. Lastly, treatment of mice with a small molecule (ABR-215050) that inhibits S100A9 binding to TLR4 inhibited EL4 tumor growth. Thus, S100A9 and TLR4 appear to be involved in promoting tumor growth in two different tumor models and pharmacological inhibition of S100A9-TLR4 interactions is a novel and promising target for anti-tumor therapies. PMID:22470535

Reorientational properties of fluorescent analogues of the protein kinase C cofactors diacylglycerol and phorbol ester.

NARCIS (Netherlands)

Pap, E.H.W.; Ketelaars, M.; Borst, J.W.; Hoek, van A.; Visser, A.J.W.G.

1996-01-01

The reorientational properties of the fluorescently labelled protein kinase C (PKC) cofactors diacylglycerol (DG) and phorbol ester (PMA) in vesicles and mixed micelles have been investigated using time-resolved polarised fluorescence. The sn-2 acyl chain of DG was replaced by diphenylhexatriene-

Comparing the outcomes of two strategies for colorectal tumor detection: policy-promoted screening program versus health promotion service.

Science.gov (United States)

Wu, Ping-Hsiu; Lin, Yu-Min; Liao, Chao-Sheng; Chang, Hung-Chuen; Chen, Yu-Hung; Yang, Kuo-Ching; Shih, Chia-Hui

2013-06-01

The Taiwanese government has proposed a population-based colorectal tumor detection program for the average-risk population. This study's objectives were to understand the outcomes of these screening policies and to evaluate the effectiveness of the program. We compared two databases compiled in one medical center. The "policy-promoted cancer screening" (PPS) database was built on the basis of the policy of the Taiwan Bureau of National Health Insurance for cancer screening. The "health promotion service" (HPS) database was built to provide health check-ups for self-paid volunteers. Both the PPS and HPS databases employ the immunochemical fecal occult blood test (iFOBT) and colonoscopy for colorectal tumor screening using different strategies. A comparison of outcomes between the PPS and HPS included: (1) quality indicators-compliance rate, cecum reaching rate, and tumor detection rate; and (2) validity indicators-sensitivity, specificity, positive, and negative predictive values for detecting colorectal neoplasms. A total of 10,563 and 1481 individuals were enrolled in PPS and HPS, respectively. Among quality indicators, there was no statistically significant difference in the cecum reaching rate between PPS and HPS. The compliance rates were 56.1% for PPS and 91.8% for HPS (p performance. Copyright © 2013. Published by Elsevier B.V.

Recurrent TERT promoter mutations identified in a large-scale study of multiple tumor types are associated with increased TERT expression and telomerase activation

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Huang, Dong-Sheng; Wang, Zhaohui; He, Xu-Jun; Diplas, Bill H.; Yang, Rui; Killela, Patrick J.; Liang, Junbo; Meng, Qun; Ye, Zai-Yuan; Wang, Wei; Jiang, Xiao-Ting; Xu, Li; He, Xiang-Lei; Zhao, Zhong-Sheng; Xu, Wen-Juan; Wang, Hui-Ju; Ma, Ying-Yu; Xia, Ying-Jie; Li, Li; Zhang, Ru-Xuan; Jin, Tao; Zhao, Zhong-Kuo; Xu, Ji; Yu, Sheng; Wu, Fang; Wang, Si-Zhen; Jiao, Yu-Chen; Yan, Hai; Tao, Hou-Quan

2015-01-01

Background Several somatic mutation hotspots were recently identified in the TERT promoter region in human cancers. Large scale studies of these mutations in multiple tumor types are limited, in particular in Asian populations. This study aimed to: analyze TERT promoter mutations in multiple tumor types in a large Chinese patient cohort, investigate novel tumor types and assess the functional significance of the mutations. Methods TERT promoter mutation status was assessed by Sanger sequencing for 13 different tumor types and 799 tumor tissues from Chinese cancer patients. Thymic epithelial tumors, gastrointestinal leiomyoma, and gastric schwannoma were included, for which the TERT promoter has not been previously sequenced. Functional studies included TERT expression by RT-qPCR, telomerase activity by the TRAP assay, and promoter activity by the luciferase reporter assay. Results TERT promoter mutations were highly frequent in glioblastoma (83.9%), urothelial carcinoma (64.5%), oligodendroglioma (70.0%), medulloblastoma (33.3%), and hepatocellular carcinoma (31.4%). C228T and C250T were the most common mutations. In urothelial carcinoma, several novel rare mutations were identified. TERT promoter mutations were absent in GIST, thymic epithelial tumors, gastrointestinal leiomyoma, gastric schwannoma, cholangiocarcinoma, gastric and pancreatic cancer. TERT promoter mutations highly correlated with upregulated TERT mRNA expression and telomerase activity in adult gliomas. These mutations differentially enhanced the transcriptional activity of the TERT core promoter. Conclusions TERT promoter mutations are frequent in multiple tumor types and have similar distributions in Chinese cancer patients. The functional significance of these mutations reflect the importance to telomere maintenance and hence tumorigenesis, making them potential therapeutic targets. PMID:25843513

Distinct cytoplasmic domains of the growth hormone receptor are required for glucocorticoid- and phorbol ester-induced decreases in growth hormone (GH) binding. These domains are different from that reported for GH-induced receptor internalization

DEFF Research Database (Denmark)

King, A P; Tseng, M J; Logsdon, C D

1996-01-01

Glucocorticoids inhibit growth in children and antagonize the growth-promoting action of GH in peripheral tissues. Recently, they have been shown to decrease GH binding. In this study we examine the molecular mechanisms by which the glucocorticoid dexamethasone (DEX) and the phorbol ester phorbol...... of GH binding are also observed in a Chinese hamster ovary (CHO) cell line stably transfected with a rat liver GHR cDNA, further arguing that DEX and PMA act post-translationally on GHR. Using mutant GHRs stably expressed in CHO cells, amino acids 455-506 and tyrosines 333 and/or 338 of GHR were shown...... to be required for maximal DEX-induced inhibition of GH binding. DEX decreased GH binding to a GHR mutant F346A, which is reported to be deficient in ligand-induced internalization, suggesting that DEX decreases GH binding by a mechanism distinct from that of ligand-induced GHR internalization. PMA reduced GH...

Evaluation of promoter methylation status of MLH1 gene in Iranian patients with colorectal tumors and adenoma polyps.

Science.gov (United States)

Zarandi, Ashkan; Irani, Shiva; Savabkar, Sanaz; Chaleshi, Vahid; Ghavideldarestani, Maryam; Mirfakhraie, Reza; Khodadoostan, Mahsa; Nazemalhosseini-Mojarad, Ehsan; Asadzadeh Aghdaei, Hamid

2017-01-01

The aim of this study was to evaluate the methylation status of the promoter region of MLH1 gene in colorectal cancer (CRC) and its precursor lesions as well as elucidate its association with various clinicopathological characteristics among Iranian population. Epigenetic silencing of mismatch repair genes, such as MLH1 , by methylation of CpG islands of their promoter region has been proved to be an important mechanism in colorectal carcinogenesis. Fifty colorectal cancer and polyp tissue samples including 13 Primary colorectal tumor and 37 Adenoma polyp samples were enrolled in this study. Methylation-specific polymerase chain reaction (MSP) was performed to find the frequency of MLH1 Promoter Methylation. Promoter methylation of MLH1 gene was detected in 5 out of 13 tumor tissues and 4 out of 37 adenoma polyp. The frequency of MLH1 methylation in tumor samples was significantly higher compared to that in polyp tissues (P= 0.026). No significant association was observed between MLH1 promoter methylation and clinicopathological characteristics of the patients. The frequency of  MLH1  promoter methylation in CRC and colon polyp was 18%. Our findings indicated that methylation of MLH1 promoter region alone cannot be considered as a biomarker for early detection of CRC.

The Notch ligand delta-like 3 promotes tumor growth and inhibits Notch signaling in lung cancer cells in mice

International Nuclear Information System (INIS)

Deng, San-Ming; Yan, Xian-Chun; Liang, Liang; Wang, Li; Liu, Yuan; Duan, Juan-Li; Yang, Zi-Yan; Chang, Tian-Fang; Ruan, Bai; Zheng, Qi-Jun; Han, Hua

2017-01-01

Although it has been suggested that Dll3, one of the Notch ligands, promotes the proliferation and inhibits the apoptosis of cancer cells, the role of Dll3 in cancers remains unclear. In this study, we found that in the murine Lewis lung carcinoma (LLC) cells, the level of Dll3 mRNA changed upon tumor microenvironment (TME) stimulation, namely, decreased under hypoxia or stimulated with tumor necrosis factor (TNF)-α. Dll3 was also expressed at higher level in human lung carcinoma tissues than in the para-carcinoma tissues. Overexpression of Dll3 in LLC cells promoted cell proliferation and reduced apoptosis in vitro, and enhanced tumor growth when inoculated in vivo in mice. The Dll3-mediated proliferation could be due to increased Akt phosphorylation in LLC cells, because an Akt inhibitor counteracted Dll3-induced proliferation. Moreover, Dll3 overexpression promoted PI3K/Akt signaling through inhibiting Notch signaling. - Highlights: • The level of Dll3 in Lewis lung carcinoma changed upon tumor microenvironment (TME) stimulation, namely, decreased under hypoxia or stimulated with TNF-α. • The Dll3 was rarely detectable in the para-carcinoma tissues, but positive in 82.1% of NSCLC tissues from 84 patients. • Overexpression of Dll3 in LLC cells promoted tumor growth but did not remarkably alter TME after inoculated in mice. • Overexpression of Dll3 in LLC cells promoted cell proliferation and reduced apoptosis in vitro in an Akt-dependent way. • Dll3 overexpression promoted PI3K/Akt signaling through inhibiting Notch signaling.

Lysophosphatidic acid acyltransferase β (LPAATβ promotes the tumor growth of human osteosarcoma.

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Farbod Rastegar

2010-12-01

Full Text Available Osteosarcoma is the most common primary malignancy of bone with poorly characterized molecular pathways important in its pathogenesis. Increasing evidence indicates that elevated lipid biosynthesis is a characteristic feature of cancer. We sought to investigate the role of lysophosphatidic acid acyltransferase β (LPAATβ, aka, AGPAT2 in regulating the proliferation and growth of human osteosarcoma cells. LPAATβ can generate phosphatidic acid, which plays a key role in lipid biosynthesis as well as in cell proliferation and survival. Although elevated expression of LPAATβ has been reported in several types of human tumors, the role of LPAATβ in osteosarcoma progression has yet to be elucidated.Endogenous expression of LPAATβ in osteosarcoma cell lines is analyzed by using semi-quantitative PCR and immunohistochemical staining. Adenovirus-mediated overexpression of LPAATβ and silencing LPAATβ expression is employed to determine the effect of LPAATβ on osteosarcoma cell proliferation and migration in vitro and osteosarcoma tumor growth in vivo. We have found that expression of LPAATβ is readily detected in 8 of the 10 analyzed human osteosarcoma lines. Exogenous expression of LPAATβ promotes osteosarcoma cell proliferation and migration, while silencing LPAATβ expression inhibits these cellular characteristics. We further demonstrate that exogenous expression of LPAATβ effectively promotes tumor growth, while knockdown of LPAATβ expression inhibits tumor growth in an orthotopic xenograft model of human osteosarcoma.Our results strongly suggest that LPAATβ expression may be associated with the aggressive phenotypes of human osteosarcoma and that LPAATβ may play an important role in regulating osteosarcoma cell proliferation and tumor growth. Thus, targeting LPAATβ may be exploited as a novel therapeutic strategy for the clinical management of osteosarcoma. This is especially attractive given the availability of selective

Macrophages From Irradiated Tumors Express Higher Levels of iNOS, Arginase-I and COX-2, and Promote Tumor Growth

International Nuclear Information System (INIS)

Tsai, C.-S.; Chen, F.-H.; Wang, C.-C.; Huang, H.-L.; Jung, Shih-Ming; Wu, C.-J.; Lee, C.-C.; McBride, William H.; Chiang, C.-S.; Hong, J.-H.

2007-01-01

Purpose: To investigate the effects of single and fractionated doses of radiation on tumors and tumor-associated macrophages (TAMs), and to elucidate the potential of TAMs to influence tumor growth. Methods and Materials: A murine prostate cell line, TRAMP-C1, was grown in C57Bl/6J mice to 4-mm tumor diameter and irradiated with either 25 Gy in a single dose, or 60 Gy in 15 fractions. The tumors were removed at the indicated times and assessed for a variety of markers related to TAM content, activation status, and function. Results: In tumors receiving a single radiation dose, arginase (Arg-I), and cycloxygenase-2 (COX-2) mRNA expression increased as a small transient wave within 24 h and a larger persistent wave starting after 3 days. Inducible nitric oxide synthase (iNOS) mRNA was elevated only after 3 days and continued to increase up to 3 weeks. After fractionated irradiation, Arg-1 and COX-2 mRNA levels increased within 5 days, whereas iNOS was increased only after 10 fractions of irradiation had been given. Increased levels of Arg-I, COX-2, and, to a lesser extent, iNOS protein were found to associate with TAMs 1-2 weeks after tumor irradiation. Function of TAMs were compared by mixing them with TRAMP-C1 cells and injecting them into mice; TRAMP-C1 cells mixed with TAMs from irradiated tumors appeared earlier and grew significantly faster than those mixed with TAMs from unirradiated tumors or TRAMP-C1 alone. Conclusions: Tumor-associated macrophages in the postirradiated tumor microenvironment express higher levels of Arg-1, COX-2, and iNOS, and promote early tumor growth in vivo

Short-term biomarkers of tumor promotion in mouse skin treated with petroleum middle distillates.

Science.gov (United States)

Walborg, E F; DiGiovanni, J; Conti, C J; Slaga, T J; Freeman, J J; Steup, D R; Skisak, C M

1998-10-01

Topical application of certain petroleum middle distillates (PMD) to mice produces skin tumors after long latency, and initiation/promotion protocols indicate that this effect is associated with their tumor promoting activity. Since induction of sustained, potentiated epidermal hyperplasia is predictive of promoting activity, five compositionally distinct PMD [hydrodesulfurized kerosene (API 81-07); hydrodesulfurized PMD (API 81-10); odorless light petroleum hydrocarbons; severely hydrotreated light vacuum distillate (LVD); and lightly refined paraffinic oil (LRPO)] were assessed for their effects on epidermal hyperplasia. PMD were administered (2 x/week for 2 weeks) to skin of CD-1 mice. Four quantitative biomarkers of epidermal hyperplasia were evaluated: epidermal thickness, number of nucleated epidermal cells per unit length of basement membrane, labeling (BrdUrd) index of epidermal cells, and induction of epidermal ornithine decarboxylase (ODC) activity. As positive controls, 12-O-tetradecanoylphorbol-13-acetate (TPA) and n-dodecane were utilized. PMD-induced skin irritation was evaluated visually and/or histopathologically. All five PMD produced dose-dependent, skin irritation and epidermal hyperplasia. On a weight basis the magnitude of the maximal PMD-induced effects was similar to that produced by n-dodecane, but > 1000-fold less than that produced by TPA. Epidermal hyperplasia and subacute skin irritancy produced by the five PMD were similar. Of the four short-term markers of tumor promotion assessed, labeling index and epidermal ODC activity were predictive of the relative promoting activities of those PMD for which tumorigenicity bioassay data are available, i.e., API 81-07 > API 81-10 > LRPO. An apparent discrepancy to the predictability of epidermal ODC activity occurred with LRPO:toluene [1:1 (v/v)]. This mixture is nontumorigenic, yet significantly induced epidermal ODC activity. This mixture, however, produced severe epidermal toxicity that

Promotion of seminomatous tumors by targeted overexpression of glial cell line-derived neurotrophic factor in mouse testis

NARCIS (Netherlands)

Meng, X.; de rooij, D. G.; Westerdahl, K.; Saarma, M.; Sariola, H.

2001-01-01

We show with transgenic mice that targeted overexpression of glial cell line-derived neurotrophic factor (GDNF) in undifferentiated spermatogonia promotes malignant testicular tumors, which express germ-cell markers. The tumors are invasive and contain aneuploid cells, but no distant metastases have

Homogeneous MGMT immunoreactivity correlates with an unmethylated MGMT promoter status in brain metastases of various solid tumors.

Directory of Open Access Journals (Sweden)

Barbara Ingold

Full Text Available The O(6-methylguanine-methyltransferase (MGMT promoter methylation status is a predictive parameter for the response of malignant gliomas to alkylating agents such as temozolomide. First clinical reports on treating brain metastases with temozolomide describe varying effects. This may be due to the fact that MGMT promoter methylation of brain metastases has not yet been explored in depth. Therefore, we assessed MGMT promoter methylation of various brain metastases including those derived from lung (n = 91, breast (n = 72 kidney (n = 49 and from malignant melanomas (n = 113 by methylation-specific polymerase chain reaction (MS-PCR and MGMT immunoreactivity. Fifty-nine of 199 brain metastases (29.6% revealed a methylated MGMT promoter. The methylation rate was the highest in brain metastases derived from lung carcinomas (46.5% followed by those from breast carcinoma (28.8%, malignant melanoma (24.7% and from renal carcinoma (20%. A significant correlation of homogeneous MGMT-immunoreactivity (>95% MGMT positive tumor cells and an unmethylated MGMT promoter was found. Promoter methylation was detected in 26 of 61 (43% tumors lacking MGMT immunoreactivity, in 17 of 63 (27% metastases with heterogeneous MGMT expression, but only in 5 of 54 brain metastases (9% showing a homogeneous MGMT immunoreactivity. Our results demonstrate that a significant number of brain metastases reveal a methylated MGMT-promoter. Based on an obvious correlation between homogeneous MGMT immunoreactivity and unmethylated MGMT promoter, we hypothesize that immunohistochemistry for MGMT may be a helpful diagnostic tool to identify those tumors that probably will not benefit from the use of alkylating agents. The discrepancy between promoter methylation and a lack of MGMT immunoreactivity argues for assessing MGMT promoter methylation both by immunohistochemical as well as by molecular approaches for diagnostic purposes.

Indolo[3,2-b]carbazole inhibits gap junctional intercellular communication in rat primary hepatocytes and acts as a potential tumor promoter

DEFF Research Database (Denmark)

Herrmann, Susan; Seidelin, Michel; Bisgaard, Hanne Cathrine

2002-01-01

Indole-3-carbinol (I3C) is a naturally occurring substance that shows anti-carcinogenic properties in animal models. Besides its clear anti-carcinogenic effects, some studies indicate that I3C may sometimes act as a tumor promoter. Indolo[3,2-b]carbazole (ICZ), which is formed in the acidic...... environment of the stomach after intake of I3C, has a similar structure to, and shares biological effects with, the well-known tumor promoter 2,3,7,8-tetrachlorodibenzo-pdioxin (TCDD). Therefore, we hypothesized that ICZ could be responsible for the potential tumor-promoting activity of I3C. The aim...

Semaphorin7A promotes tumor growth and exerts a pro-angiogenic effect in macrophages of mammary tumor-bearing mice

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Ramon eGarcia-Areas

2014-02-01

Full Text Available Semaphorins, a large family of molecules involved in the axonal guidance and development of the nervous system, have been recently shown to have both angiogenic and anti-angiogenic properties. Specifically, semaphorin 7A (SEMA7A has been reported to have a chemotactic activity in neurogenesis, and to be an immune modulator via it binding to α1β1integrins. Additionally, SEMA7A has been shown to promote chemotaxis of monocytes, inducing them to produce proinflammatory mediators. In this study we explored the role of SEMA7A in the tumoral context. We show that SEMA7A is highly expressed by DA-3 murine mammary tumor cells in comparison to normal mammary cells (EpH4, and that peritoneal macrophages from mammary tumor-bearing mice also express SEMA7A at higher levels compared to peritoneal macrophages derived from normal control mice. We also show that murine macrophages treated with recombinant murine SEMA7A significantly increased their expression of proangiogenic molecules, such as CXCL2/MIP-2. Gene silencing of SEMA7A in peritoneal elicited macrophages from DA-3 tumor-bearing mice resulted in decreased CXCL2 expression. Mice implanted with SEMA7A silenced tumor cells showed decreased angiogenesis in the tumors compared to the wild type tumors. Furthermore, peritoneal elicited macrophages from mice bearing SEMA7A-silenced tumors produce significantly (p< 0.01 lower levels of angiogenic proteins, such as MIP-2, CXCL1 and MMP-9, compared to macrophages from control DA-3 mammary tumors. We postulate that SEMA7A derived from mammary carcinomas may serve as a monocyte chemoattractant and skew monocytes into a pro-tumorigenic phenotype. A putative relationship between tumor-derived SEMA7A and monocytes could prove valuable in establishing new research avenues towards unraveling important tumor-host immune interactions in breast cancer patients.

The potential of white-rot fungi to degrade phorbol esters of Jatropha curcas L. seed cake

NARCIS (Netherlands)

Barros, de C.R.M.; Ferreira, L.M.M.; Nunes, F.M.; Bezerra, R.M.F.; Dias, A.A.; Guedes, C.; Cone, J.W.; Marques, G.S.M.; Rodrigues, M.A.M.

2011-01-01

The potential of solid-state cultivation, with three white-rot fungi (Bjerkandera adusta, Ganoderma resinaceum and Phlebia rufa), to decrease phorbol esters concentration of Jatropha curcas L. was evaluated in this study. Incubation was conducted in 250¿mL Erlenmeyer flasks without agitation at 28°C

Development of a flexible and potent hypoxia-inducible promoter for tumor-targeted gene expression in attenuated Salmonella

NARCIS (Netherlands)

Mengesha, Asferd; Dubois, Ludwig; Lambin, Philippe; Landuyt, Willy; Chiu, Roland K; Wouters, Bradly G; Theys, Jan

To increase the potential of attenuated Salmonella as gene delivery vectors for cancer treatment, we developed a hypoxia-inducible promoter system to limit gene expression specifically to the tumor. This approach is envisaged to not only increase tumor specificity, but also to target those cells

Oligodeoxynucleotides Expressing Polyguanosine Motifs Promote Anti-Tumor Activity through the Up-Regulation of IL-2

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Kobayashi, Nobuaki; Hong, Choongman; Klinman, Dennis M.; Shirota, Hidekazu

2012-01-01

The primary goal of cancer immunotherapy is to elicit an immune response capable of eliminating the tumor. One approach towards accomplishing that goal utilizes general (rather than tumor-specific) immunomodulatory agents to boost the number and activity of pre-existing cytotoxic T lymphocytes. We find that the intra-tumoral injection of poly-G ODN has such an effect, boosting anti-tumor immunity and promoting tumor regression. The anti-tumor activity of polyguanosine (poly-G) oligonucleotides (ODN) was mediated through CD8 T cells in a TLR9 independent manner. Mechanistically, poly-G ODN directly induced the phosphorylation of Lck (an essential element of the T cell signaling pathway), thereby enhancing the production of IL-2 and CD8 T cell proliferation. These findings establish poly-G ODN as a novel type of cancer immunotherapy. PMID:23296706

TLR5 signaling, commensal microbiota and systemic tumor promoting inflammation: the three parcae of malignant progression.

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Rutkowski, Melanie R; Conejo-Garcia, Jose R

2015-08-01

We have reported that TLR5-mediated recognition of commensal microbiota modulates systemic tumor-promoting inflammation and malignant progression of tumors at distal locations. Approximately 7-10% of the general population harbors a deleterious single nucleotide polymorphism in TLR5, implicating a novel role for genetic variation during the initiation and progression of cancer.

Detachment-induced E-cadherin expression promotes 3D tumor spheroid formation but inhibits tumor formation and metastasis of lung cancer cells.

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Powan, Phattrakorn; Luanpitpong, Sudjit; He, Xiaoqing; Rojanasakul, Yon; Chanvorachote, Pithi

2017-11-01

The epithelial-to-mesenchymal transition is proposed to be a key mechanism responsible for metastasis-related deaths. Similarly, cancer stem cells (CSCs) have been proposed to be a key driver of tumor metastasis. However, the link between the two events and their control mechanisms is unclear. We used a three-dimensional (3D) tumor spheroid assay and other CSC-indicating assays to investigate the role of E-cadherin in CSC regulation and its association to epithelial-to-mesenchymal transition in lung cancer cells. Ectopic overexpression and knockdown of E-cadherin were found to promote and retard, respectively, the formation of tumor spheroids in vitro but had opposite effects on tumor formation and metastasis in vivo in a xenograft mouse model. We explored the discrepancy between the in vitro and in vivo results and demonstrated, for the first time, that E-cadherin is required as a component of a major survival pathway under detachment conditions. Downregulation of E-cadherin increased the stemness of lung cancer cells but had an adverse effect on their survival, particularly on non-CSCs. Such downregulation also promoted anoikis resistance and invasiveness of lung cancer cells. These results suggest that anoikis assay could be used as an alternative method for in vitro assessment of CSCs that involves dysregulated adhesion proteins. Our data also suggest that agents that restore E-cadherin expression may be used as therapeutic agents for metastatic cancers. Copyright © 2017 the American Physiological Society.

T Cell Intrinsic USP15 Deficiency Promotes Excessive IFN-γ Production and an Immunosuppressive Tumor Microenvironment in MCA-Induced Fibrosarcoma

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Qiang Zou

2015-12-01

Full Text Available USP15 is a deubiquitinase that negatively regulates activation of naive CD4+ T cells and generation of IFN-γ-producing T helper 1 (Th1 cells. USP15 deficiency in mice promotes antitumor T cell responses in a transplantable cancer model; however, it has remained unclear how deregulated T cell activation impacts primary tumor development during the prolonged interplay between tumors and the immune system. Here, we find that the USP15-deficient mice are hypersensitive to methylcholantrene (MCA-induced fibrosarcomas. Excessive IFN-γ production in USP15-deficient mice promotes expression of the immunosuppressive molecule PD-L1 and the chemokine CXCL12, causing accumulation of T-bet+ regulatory T cells and CD11b+Gr-1+ myeloid-derived suppressor cells at tumor site. Mixed bone marrow adoptive transfer studies further reveals a T cell-intrinsic role for USP15 in regulating IFN-γ production and tumor development. These findings suggest that T cell intrinsic USP15 deficiency causes excessive production of IFN-γ, which promotes an immunosuppressive tumor microenvironment during MCA-induced primary tumorigenesis.

Caspase-1 from Human Myeloid-Derived Suppressor Cells Can Promote T Cell-Independent Tumor Proliferation.

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Zeng, Qi; Fu, Juan; Korrer, Michael; Gorbounov, Mikhail; Murray, Peter J; Pardoll, Drew; Masica, David L; Kim, Young J

2018-05-01

Immunosuppressive myeloid-derived suppressive cells (MDSCs) are characterized by their phenotypic and functional heterogeneity. To better define their T cell-independent functions within the tumor, sorted monocytic CD14 + CD11b + HLA-DR low/- MDSCs (mMDSC) from squamous cell carcinoma patients showed upregulated caspase-1 activity, which was associated with increased IL1β and IL18 expression. In vitro studies demonstrated that mMDSCs promoted caspase-1-dependent proliferation of multiple squamous carcinoma cell lines in both human and murine systems. In vivo , growth rates of B16, MOC1, and Panc02 were significantly blunted in chimeric mice adoptively transferred with caspase-1 null bone marrow cells under T cell-depleted conditions. Adoptive transfer of wild-type Gr-1 + CD11b + MDSCs from tumor-bearing mice reversed this antitumor response, whereas caspase-1 inhibiting thalidomide-treated MDSCs phenocopied the antitumor response found in caspase-1 null mice. We further hypothesized that MDSC caspase-1 activity could promote tumor-intrinsic MyD88-dependent carcinogenesis. In mice with wild-type caspase-1, MyD88-silenced tumors displayed reduced growth rate, but in chimeric mice with caspase-1 null bone marrow cells, MyD88-silenced tumors did not display differential tumor growth rate. When we queried the TCGA database, we found that caspase-1 expression is correlated with overall survival in squamous cell carcinoma patients. Taken together, our findings demonstrated that caspase-1 in MDSCs is a direct T cell-independent mediator of tumor proliferation. Cancer Immunol Res; 6(5); 566-77. ©2018 AACR . ©2018 American Association for Cancer Research.

Increased expression of CYP4Z1 promotes tumor angiogenesis and growth in human breast cancer

International Nuclear Information System (INIS)

Yu, Wei; Chai, Hongyan; Li, Ying; Zhao, Haixia; Xie, Xianfei; Zheng, Hao; Wang, Chenlong; Wang, Xue; Yang, Guifang; Cai, Xiaojun; Falck, John R.; Yang, Jing

2012-01-01

Cytochrome P450 (CYP) 4Z1, a novel CYP4 family member, is over-expressed in human mammary carcinoma and associated with high-grade tumors and poor prognosis. However, the precise role of CYP4Z1 in tumor progression is unknown. Here, we demonstrate that CYP4Z1 overexpression promotes tumor angiogenesis and growth in breast cancer. Stable expression of CYP4Z1 in T47D and BT-474 human breast cancer cells significantly increased mRNA expression and production of vascular endothelial growth factor (VEGF)-A, and decreased mRNA levels and secretion of tissue inhibitor of metalloproteinase-2 (TIMP-2), without affecting cell proliferation and anchorage-independent cell growth in vitro. Notably, the conditioned medium from CYP4Z1-expressing cells enhanced proliferation, migration and tube formation of human umbilical vein endothelial cells, and promoted angiogenesis in the zebrafish embryo and chorioallantoic membrane of the chick embryo. In addition, there were lower levels of myristic acid and lauric acid, and higher contents of 20-hydroxyeicosatetraenoic acid (20-HETE) in CYP4Z1-expressing T47D cells compared with vector control. CYP4Z1 overexpression significantly increased tumor weight and microvessel density by 2.6-fold and 1.9-fold in human tumor xenograft models, respectively. Moreover, CYP4Z1 transfection increased the phosphorylation of ERK1/2 and PI3K/Akt, while PI3K or ERK inhibitors and siRNA silencing reversed CYP4Z1-mediated changes in VEGF-A and TIMP-2 expression. Conversely, HET0016, an inhibitor of the CYP4 family, potently inhibited the tumor-induced angiogenesis with associated changes in the intracellular levels of myristic acid, lauric acid and 20-HETE. Collectively, these data suggest that increased CYP4Z1 expression promotes tumor angiogenesis and growth in breast cancer partly via PI3K/Akt and ERK1/2 activation. -- Highlights: ► CYP4Z1 overexpression promotes human breast cancer growth and angiogenesis. ► The pro-angiogenic effects of CYP4Z1 have

Increased expression of CYP4Z1 promotes tumor angiogenesis and growth in human breast cancer

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Yu, Wei [Department of Pharmacology, School of Medicine, Wuhan University, Wuhan 430071 (China); Chai, Hongyan [Center for Gene Diagnosis, Zhongnan Hospital, Wuhan University, Wuhan 430071 (China); Li, Ying; Zhao, Haixia; Xie, Xianfei; Zheng, Hao; Wang, Chenlong; Wang, Xue [Department of Pharmacology, School of Medicine, Wuhan University, Wuhan 430071 (China); Yang, Guifang [Department of Pathology, Zhongnan Hospital, Wuhan University, Wuhan 430071 (China); Cai, Xiaojun [Department of Ophthalmology, Zhongnan Hospital, Wuhan University, Wuhan 430071 (China); Falck, John R. [Department of Biochemistry, University of Texas Southwestern Medical Center, Dallas, TX 75390 (United States); Yang, Jing, E-mail: yangjingliu@yahoo.com.cn [Department of Pharmacology, School of Medicine, Wuhan University, Wuhan 430071 (China); Research Center of Food and Drug Evaluation, Wuhan University, Wuhan 430071 (China)

2012-10-01

Cytochrome P450 (CYP) 4Z1, a novel CYP4 family member, is over-expressed in human mammary carcinoma and associated with high-grade tumors and poor prognosis. However, the precise role of CYP4Z1 in tumor progression is unknown. Here, we demonstrate that CYP4Z1 overexpression promotes tumor angiogenesis and growth in breast cancer. Stable expression of CYP4Z1 in T47D and BT-474 human breast cancer cells significantly increased mRNA expression and production of vascular endothelial growth factor (VEGF)-A, and decreased mRNA levels and secretion of tissue inhibitor of metalloproteinase-2 (TIMP-2), without affecting cell proliferation and anchorage-independent cell growth in vitro. Notably, the conditioned medium from CYP4Z1-expressing cells enhanced proliferation, migration and tube formation of human umbilical vein endothelial cells, and promoted angiogenesis in the zebrafish embryo and chorioallantoic membrane of the chick embryo. In addition, there were lower levels of myristic acid and lauric acid, and higher contents of 20-hydroxyeicosatetraenoic acid (20-HETE) in CYP4Z1-expressing T47D cells compared with vector control. CYP4Z1 overexpression significantly increased tumor weight and microvessel density by 2.6-fold and 1.9-fold in human tumor xenograft models, respectively. Moreover, CYP4Z1 transfection increased the phosphorylation of ERK1/2 and PI3K/Akt, while PI3K or ERK inhibitors and siRNA silencing reversed CYP4Z1-mediated changes in VEGF-A and TIMP-2 expression. Conversely, HET0016, an inhibitor of the CYP4 family, potently inhibited the tumor-induced angiogenesis with associated changes in the intracellular levels of myristic acid, lauric acid and 20-HETE. Collectively, these data suggest that increased CYP4Z1 expression promotes tumor angiogenesis and growth in breast cancer partly via PI3K/Akt and ERK1/2 activation. -- Highlights: ► CYP4Z1 overexpression promotes human breast cancer growth and angiogenesis. ► The pro-angiogenic effects of CYP4Z1 have

A Multi-targeted Approach to Suppress Tumor-Promoting Inflammation

Science.gov (United States)

Samadi, Abbas K.; Georgakilas, Alexandros G.; Amedei, Amedeo; Amin, Amr; Bishayee, Anupam; Lokeshwar, Bal L.; Grue, Brendan; Panis, Carolina; Boosani, Chandra S.; Poudyal, Deepak; Stafforini, Diana M.; Bhakta, Dipita; Niccolai, Elena; Guha, Gunjan; Rupasinghe, H.P. Vasantha; Fujii, Hiromasa; Honoki, Kanya; Mehta, Kapil; Aquilano, Katia; Lowe, Leroy; Hofseth, Lorne J.; Ricciardiello, Luigi; Ciriolo, Maria Rosa; Singh, Neetu; Whelan, Richard L.; Chaturvedi, Rupesh; Ashraf, S. Salman; Kumara, HMC Shantha; Nowsheen, Somaira; Mohammed, Sulma I.; Helferich, William G.; Yang, Xujuan

2015-01-01

Cancers harbor significant genetic heterogeneity and patterns of relapse following many therapies are due to evolved resistance to treatment. While efforts have been made to combine targeted therapies, significant levels of toxicity have stymied efforts to effectively treat cancer with multi-drug combinations using currently approved therapeutics. We discuss the relationship between tumor-promoting inflammation and cancer as part of a larger effort to develop a broad-spectrum therapeutic approach aimed at a wide range of targets to address this heterogeneity. Specifically, macrophage migration inhibitory factor, cyclooxygenase-2, transcription factor nuclear factor-kappaB, tumor necrosis factor alpha, inducible nitric oxide synthase, protein kinase B, and CXC chemokines are reviewed as important antiinflammatory targets while curcumin, resveratrol, epigallocatechin gallate, genistein, lycopene, and anthocyanins are reviewed as low-cost, low toxicity means by which these targets might all be reached simultaneously. Future translational work will need to assess the resulting synergies of rationally designed antiinflammatory mixtures (employing low-toxicity constituents), and then combine this with similar approaches targeting the most important pathways across the range of cancer hallmark phenotypes. PMID:25951989

1,2-Diacylglycerols, but not phorbol esters, activate a potential inhibitory pathway for protein kinase C in GH3 pituitary cells. Evidence for involvement of a sphingomyelinase.

Science.gov (United States)

Kolesnick, R N; Clegg, S

1988-05-15

It has been suggested that sphingoid bases may serve as physiologic inhibitors of protein kinase C. Because 1,2-diacylglycerols, but not phorbol esters, enhance sphingomyelin degradation via a sphingomyelinase in GH3 pituitary cells (Kolesnick, R. N. (1987) J. Biol. Chem. 262, 16759-16762), the effects of phorbol esters, 1,2-diacylglycerols, and sphingomyelinase on protein kinase C activation were assessed. Under basal conditions, the inactive cytosolic form of protein kinase C predominated. 1,2-Diacylglycerols stimulated transient protein kinase C redistribution to the membrane. 1,2-Dioctanoylglycerol (200 micrograms/ml) reduced cytosolic protein kinase C activity to 67% of control from 72 to 48 pmol.min-1.10(6) cells-1 and enhanced membrane-bound activity to 430% of control from 6 to 25 pmol.min-1.10(6) cells-1 after 4 min of stimulation. Thereafter, protein kinase C activity returned to the cytosol. In contrast, the phorbol ester, 12-O-tetradecanoylphorbol-13-acetate (TPA), stimulated redistribution to the membrane without return to the cytosol. Exogenous sphingomyelinase reduced membrane-bound protein kinase C activity to 30% of control, yet did not alter cytosolic activity. Sphingomyelinase, added after phorbol ester-induced redistribution was completed, restored activity to the cytosol. In these studies, TPA (10(-8) M) reduced cytosolic activity to 62% of control and elevated membrane-bound protein kinase C activity to 650% of control. Sphingomyelinase restored cytosolic activity to 84% of control and reduced membrane-bound activity to 297% of control. Similarly, the free sphingoid bases, sphingosine, sphinganine, and phytosphingosine, reversed phorbol ester-induced protein kinase C redistribution. Since 1,2-diacylglycerols activate a sphingomyelinase and sphingomyelinase action can reverse protein kinase C activation, these studies suggest that a pathway involving a sphingomyelinase might comprise a physiologic negative effector system for protein kinase C

Klf5 deletion promotes Pten deletion-initiated luminal-type mouse prostate tumors through multiple oncogenic signaling pathways.

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Xing, Changsheng; Ci, Xinpei; Sun, Xiaodong; Fu, Xiaoying; Zhang, Zhiqian; Dong, Eric N; Hao, Zhao-Zhe; Dong, Jin-Tang

2014-11-01

Krüppel-like factor 5 (KLF5) regulates multiple biologic processes. Its function in tumorigenesis appears contradictory though, showing both tumor suppressor and tumor promoting activities. In this study, we examined whether and how Klf5 functions in prostatic tumorigenesis using mice with prostate-specific deletion of Klf5 and phosphatase and tensin homolog (Pten), both of which are frequently inactivated in human prostate cancer. Histologic analysis demonstrated that when one Pten allele was deleted, which causes mouse prostatic intraepithelial neoplasia (mPIN), Klf5 deletion accelerated the emergence and progression of mPIN. When both Pten alleles were deleted, which causes prostate cancer, Klf5 deletion promoted tumor growth, increased cell proliferation, and caused more severe morphologic and molecular alterations. Homozygous deletion of Klf5 was more effective than hemizygous deletion. Unexpectedly, while Pten deletion alone expanded basal cell population in a tumor as reported, Klf5 deletion in the Pten-null background clearly reduced basal cell population while expanding luminal cell population. Global gene expression profiling, pathway analysis, and experimental validation indicate that multiple mechanisms could mediate the tumor-promoting effect of Klf5 deletion, including the up-regulation of epidermal growth factor and its downstream signaling molecules AKT and ERK and the inactivation of the p15 cell cycle inhibitor. KLF5 also appears to cooperate with several transcription factors, including CREB1, Sp1, Myc, ER and AR, to regulate gene expression. These findings validate the tumor suppressor function of KLF5. They also yield a mouse model that shares two common genetic alterations with human prostate cancer-mutation/deletion of Pten and deletion of Klf5.

Liver Tumor Promotion by 2,3,7,8-Tetrachlorodibenzo-p-dioxin Is Dependent on the Aryl Hydrocarbon Receptor and TNF/IL-1 Receptors

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Kennedy, Gregory D.; Nukaya, Manabu; Moran, Susan M.; Glover, Edward; Weinberg, Samuel; Balbo, Silvia; Hecht, Stephen S.; Pitot, Henry C.; Drinkwater, Norman R.; Bradfield, Christopher A.

2014-01-01

We set out to better understand the signal transduction pathways that mediate liver tumor promotion by 2,3,7,8-tetrachlorodibenzo-p-dioxn (“dioxin”). To this end, we first employed congenic mice homozygous for either the Ahrb1 or Ahrd alleles (encoding an aryl hydrocarbon receptor (AHR) with high or low binding affinity for dioxin, respectively) and demonstrated that hepatocellular tumor promotion in response to dioxin segregated with the Ahr locus. Once we had genetic evidence for the importance of AHR signaling, we then asked if tumor promotion by dioxin was influenced by “interleukin-1 (IL-1)-like” inflammatory cytokines. The importance of this question arose from our earlier observation that aspects of the acute hepatocellular toxicity of dioxin are dependent upon IL1-like cytokine signaling. To address this issue, we employed a triple knock-out (TKO) mouse model with null alleles at the loci encoding the three relevant receptors for tumor necrosis factors α and β and IL-1α and IL-1β (i.e., null alleles at the Tnfrsf1a, Tnfrsf1b, and Il-1r1 loci). The observation that TKO mice were resistant to the tumor promoting effects of dioxin in liver suggests that inflammatory cytokines play an important step in dioxin mediated liver tumor promotion in the mouse. Collectively, these data support the idea that the mechanism of dioxin acute hepatotoxicity and its activity as a promoter in a mouse two stage liver cancer model may be similar, i.e., tumor promotion by dioxin, like acute hepatotoxicity, are mediated by the linked action of two receptor systems, the AHR and the receptors for the “IL-1-like” cytokines. PMID:24718703

Mind the GAP: A Novel Tumor-Promoting Mechanism | Center for Cancer Research

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RAS proteins, like light switches, toggle between an “on” conformation where they promote cell growth, survival, and/or the formation of blood vessels (known as angiogenesis) and an “off” conformation in which they are unable to stimulate their target effector proteins. Nearly one-third of human tumors express a mutated RAS gene, which encodes a protein locked permanently in

Recycling of CR1 by phorbol ester-activated polymorphonuclear leukocytes (PMN)

International Nuclear Information System (INIS)

Malbran, A.; Frank, M.M.; Fries, L.

1986-01-01

PMN CR1 is internalized when these cells are stimulated with phorbol esters. To elucidate the fate of these receptors and ligand bound to them, the authors studied the uptake and disposition of 125 I-C3b by phorbol dibutyrate (PDBu)-treated PMN. C3b monomers bind to PDBu-treated PMN with a K(d) of 4.75 +/- 1.06 x 1 -8 M at 0 0 C in reduced ionic strength. This C3b remains almost entirely dissociable by high ionic strength buffer unless the cells are warmed. At 37 0 C, PDBu-treated PMN internalize monomer C3b into a non-strippable pool, reaching a plateau level of approx. 50% of bound ligand. Exocytosis of the internalized C3b was studied by washing the PMN in cold PBS, then rewarming to 37 0 . A progressive release of internalized C3b is observed, with kinetics similar to internalization and reaching a plateau of 48 +/- 4.2% at 15 minutes. Released C3b is precipitable by 10% TCA, suggesting that release does not require passage through the lysosomal compartment. PMN preloaded with 1mM chloroquine behave identically in the exocytosis phase, supporting this hypothesis. The non-recycling pool of 125 I-C3b is stable for at least 30 minutes at 37 0 . Uptake of chemically cross-linked C3b dimers by PMN is followed by slower and less complete exocytosis of internal counts, suggesting diversion into the non-releaseable pool. Activated PMN CR1 is partially recycled via a prelysosomal compartment. Minimal cross-linking shifts receptor-ligand complexes into a non-recycling, possibly lysosomal, pool

Mesenchymal stem cell 1 (MSC1-based therapy attenuates tumor growth whereas MSC2-treatment promotes tumor growth and metastasis.

Directory of Open Access Journals (Sweden)

Ruth S Waterman

Full Text Available Currently, there are many promising clinical trials using mesenchymal stem cells (MSCs in cell-based therapies of numerous diseases. Increasingly, however, there is a concern over the use of MSCs because they home to tumors and can support tumor growth and metastasis. For instance, we established that MSCs in the ovarian tumor microenvironment promoted tumor growth and favored angiogenesis. In parallel studies, we also developed a new approach to induce the conventional mixed pool of MSCs into two uniform but distinct phenotypes we termed MSC1 and MSC2.Here we tested the in vitro and in vivo stability of MSC1 and MSC2 phenotypes as well as their effects on tumor growth and spread. In vitro co-culture of MSC1 with various cancer cells diminished growth in colony forming units and tumor spheroid assays, while conventional MSCs or MSC2 co-culture had the opposite effect in these assays. Co-culture of MSC1 and cancer cells also distinctly affected their migration and invasion potential when compared to MSCs or MSC2 treated samples. The expression of bioactive molecules also differed dramatically among these samples. MSC1-based treatment of established tumors in an immune competent model attenuated tumor growth and metastasis in contrast to MSCs- and MSC2-treated animals in which tumor growth and spread was increased. Also, in contrast to these groups, MSC1-therapy led to less ascites accumulation, increased CD45+leukocytes, decreased collagen deposition, and mast cell degranulation.These observations indicate that the MSC1 and MSC2 phenotypes may be convenient tools for the discovery of critical components of the tumor stroma. The continued investigation of these cells may help ensure that cell based-therapy is used safely and effectively in human disease.

Method of phorbol ester degradation in Jatropha curcas L. seed cake using rice bran lipase.

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Hidayat, Chusnul; Hastuti, Pudji; Wardhani, Avita Kusuma; Nadia, Lana Santika

2014-03-01

A novel enzymatic degradation of phorbol esters (PE) in the jatropha seed cake was developed using lipase. Cihera rice bran lipase had the highest ability to hydrolyze PE, and reduced PE to a safe level after 8 h of incubation. Enzymatic degradation may be a promising method for PE degradation. Copyright © 2013 The Society for Biotechnology, Japan. Published by Elsevier B.V. All rights reserved.

Promoter methylation of RASSF1A and DAPK and mutations of K-ras, p53, and EGFR in lung tumors from smokers and never-smokers

International Nuclear Information System (INIS)

Liu, Yang; Gao, Weimin; Siegfried, Jill M; Weissfeld, Joel L; Luketich, James D; Keohavong, Phouthone

2007-01-01

Epidemiological studies indicate that some characteristics of lung cancer among never-smokers significantly differ from those of smokers. Aberrant promoter methylation and mutations in some oncogenes and tumor suppressor genes are frequent in lung tumors from smokers but rare in those from never-smokers. In this study, we analyzed promoter methylation in the ras-association domain isoform A (RASSF1A) and the death-associated protein kinase (DAPK) genes in lung tumors from patients with primarily non-small cell lung cancer (NSCLC) from the Western Pennsylvania region. We compare the results with the smoking status of the patients and the mutation status of the K-ras, p53, and EGFR genes determined previously on these same lung tumors. Promoter methylation of the RASSF1A and DAPK genes was analyzed by using a modified two-stage methylation-specific PCR. Data on mutations of K-ras, p53, and EGFR were obtained from our previous studies. The RASSF1A gene promoter methylation was found in tumors from 46.7% (57/122) of the patients and was not significantly different between smokers and never-smokers, but was associated significantly in multiple variable analysis with tumor histology (p = 0.031) and marginally with tumor stage (p = 0.063). The DAPK gene promoter methylation frequency in these tumors was 32.8% (40/122) and did not differ according to the patients' smoking status, tumor histology, or tumor stage. Multivariate analysis adjusted for age, gender, smoking status, tumor histology and stage showed that the frequency of promoter methylation of the RASSF1A or DAPK genes did not correlate with the frequency of mutations of the K-ras, p53, and EGFR gene. Our results showed that RASSF1A and DAPK genes' promoter methylation occurred frequently in lung tumors, although the prevalence of this alteration in these genes was not associated with the smoking status of the patients or the occurrence of mutations in the K-ras, p53 and EGFR genes, suggesting each of

Cancer cell specific cytotoxic gene expression mediated by ARF tumor suppressor promoter constructs

International Nuclear Information System (INIS)

Kurayoshi, Kenta; Ozono, Eiko; Iwanaga, Ritsuko; Bradford, Andrew P.; Komori, Hideyuki; Ohtani, Kiyoshi

2014-01-01

Highlights: • ARF promoter showed higher responsiveness to deregulated E2F activity than the E2F1 promoter. • ARF promoter showed higher cancer cell-specificity than E2F1 promoter to drive gene expression. • HSV-TK driven by ARF promoter showed higher cancer cell-specific cytotoxicity than that driven by E2F1 promoter. - Abstract: In current cancer treatment protocols, such as radiation and chemotherapy, side effects on normal cells are major obstacles to radical therapy. To avoid these side effects, a cancer cell-specific approach is needed. One way to specifically target cancer cells is to utilize a cancer specific promoter to express a cytotoxic gene (suicide gene therapy) or a viral gene required for viral replication (oncolytic virotherapy). For this purpose, the selected promoter should have minimal activity in normal cells to avoid side effects, and high activity in a wide variety of cancers to obtain optimal therapeutic efficacy. In contrast to the AFP, CEA and PSA promoters, which have high activity only in a limited spectrum of tumors, the E2F1 promoter exhibits high activity in wide variety of cancers. This is based on the mechanism of carcinogenesis. Defects in the RB pathway and activation of the transcription factor E2F, the main target of the RB pathway, are observed in almost all cancers. Consequently, the E2F1 promoter, which is mainly regulated by E2F, has high activity in wide variety of cancers. However, E2F is also activated by growth stimulation in normal growing cells, suggesting that the E2F1 promoter may also be highly active in normal growing cells. In contrast, we found that the tumor suppressor ARF promoter is activated by deregulated E2F activity, induced by forced inactivation of pRB, but does not respond to physiological E2F activity induced by growth stimulation. We also found that the deregulated E2F activity, which activates the ARF promoter, is detected only in cancer cell lines. These observations suggest that ARF promoter

Cancer cell specific cytotoxic gene expression mediated by ARF tumor suppressor promoter constructs

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Kurayoshi, Kenta [Department of Bioscience, School of Science and Technology, Kwansei Gakuin University, 2-1 Gakuen, Sanda, Hyogo 669-1337 (Japan); Ozono, Eiko [Centre for Molecular Oncology, Barts Cancer Institute, Queen Mary, University of London, John Vane Science Centre, Charterhouse Square, London EC1M 6BQ (United Kingdom); Iwanaga, Ritsuko; Bradford, Andrew P. [Department of Obstetrics and Gynecology, University of Colorado School of Medicine, Anschutz Medical Campus, 12800 East 19th Avenue, Aurora, CO 80045 (United States); Komori, Hideyuki [Center for Stem Cell Biology, Life Sciences Institute, University of Michigan, Ann Arbor, MI 48109 (United States); Ohtani, Kiyoshi, E-mail: btm88939@kwansei.ac.jp [Department of Bioscience, School of Science and Technology, Kwansei Gakuin University, 2-1 Gakuen, Sanda, Hyogo 669-1337 (Japan)

2014-07-18

Highlights: • ARF promoter showed higher responsiveness to deregulated E2F activity than the E2F1 promoter. • ARF promoter showed higher cancer cell-specificity than E2F1 promoter to drive gene expression. • HSV-TK driven by ARF promoter showed higher cancer cell-specific cytotoxicity than that driven by E2F1 promoter. - Abstract: In current cancer treatment protocols, such as radiation and chemotherapy, side effects on normal cells are major obstacles to radical therapy. To avoid these side effects, a cancer cell-specific approach is needed. One way to specifically target cancer cells is to utilize a cancer specific promoter to express a cytotoxic gene (suicide gene therapy) or a viral gene required for viral replication (oncolytic virotherapy). For this purpose, the selected promoter should have minimal activity in normal cells to avoid side effects, and high activity in a wide variety of cancers to obtain optimal therapeutic efficacy. In contrast to the AFP, CEA and PSA promoters, which have high activity only in a limited spectrum of tumors, the E2F1 promoter exhibits high activity in wide variety of cancers. This is based on the mechanism of carcinogenesis. Defects in the RB pathway and activation of the transcription factor E2F, the main target of the RB pathway, are observed in almost all cancers. Consequently, the E2F1 promoter, which is mainly regulated by E2F, has high activity in wide variety of cancers. However, E2F is also activated by growth stimulation in normal growing cells, suggesting that the E2F1 promoter may also be highly active in normal growing cells. In contrast, we found that the tumor suppressor ARF promoter is activated by deregulated E2F activity, induced by forced inactivation of pRB, but does not respond to physiological E2F activity induced by growth stimulation. We also found that the deregulated E2F activity, which activates the ARF promoter, is detected only in cancer cell lines. These observations suggest that ARF promoter

E-Cadherin loss associated with EMT promotes radioresistance in human tumor cells

International Nuclear Information System (INIS)

Theys, Jan; Jutten, Barry; Habets, Roger; Paesmans, Kim; Groot, Arjan J.; Lambin, Philippe; Wouters, Brad G.; Lammering, Guido; Vooijs, Marc

2011-01-01

Background and purpose: Hypoxia is a hallmark of solid cancers and associated with metastases and treatment failure. During tumor progression epithelial cells often acquire mesenchymal features, a phenomenon known as epithelial-to-mesenchymal transition (EMT). Intratumoral hypoxia has been linked to EMT induction. We hypothesized that signals from the tumor microenvironment such as growth factors and tumor oxygenation collaborate to promote EMT and thereby contribute to radioresistance. Materials and methods: Gene expression changes under hypoxia were analyzed using microarray and validated by qRT-PCR. Conversion of epithelial phenotype upon hypoxic exposure, TGFβ addition or oncogene activation was investigated by Western blot and immunofluorescence. Cell survival following ionizing radiation was assayed using clonogenic survival. Results: Upon hypoxia, TGFβ addition or EGFRvIII expression, MCF7, A549 and NMuMG epithelial cells acquired a spindle shape and lost cell-cell contacts. Expression of epithelial markers such as E-cadherin decreased, whereas mesenchymal markers such as vimentin and N-cadherin increased. Combining hypoxia with TGFβ or EGFRvIII expression, lead to more rapid and pronounced EMT-like phenotype. Interestingly, E-cadherin expression and the mesenchymal appearance were reversible upon reoxygenation. Mesenchymal conversion and E-cadherin loss were associated with radioresistance. Conclusions: Our findings describe a mechanism by which the tumor microenvironment may contribute to tumor radioresistance via E-cadherin loss and EMT.

Mouse Mammary Tumor Virus Promoter-Containing Retroviral Promoter Conversion Vectors for Gene-Directed Enzyme Prodrug Therapy are Functional in Vitro and in Vivo

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Reinhard Klein

2008-01-01

Full Text Available Gene directed-enzyme prodrug therapy (GDEPT is an approach for sensitization of tumor cells to an enzymatically activated, otherwise nontoxic, prodrug. Cytochrome P450 2B1 (CYP2B1 metabolizes the prodrugs cyclophosphamide (CPA and ifosfamide (IFA to produce the cytotoxic substances phosphoramide mustard and isophosphoramide mustard as well as the byproduct acrolein. We have constructed a retroviral promoter conversion (ProCon vector for breast cancer GDEPT. The vector allows expression of CYP2B1 from the mouse mammary tumor virus (MMTV promoter known to be active in the mammary glands of transgenic animals. It is anticipated to be used for the generation of encapsulated viral vector producing cells which, when placed inside or close to a tumor, will act as suppliers of the therapeutic CYP2B1 protein as well as of the therapeutic vector itself. The generated vector was effectively packaged by virus producing cells and allowed the production of high levels of enzymatically active CYP2B1 in infected cells which sensitized them to killing upon treatment with both IFA and CPA. Determination of the respective IC50 values demonstrated that the effective IFA dose was reduced by sixteen folds. Infection efficiencies in vivo were determined using a reporter gene-bearing vector in a mammary cancer cell-derived xenograft tumor mouse model.

Cancer-associated adipocytes promotes breast tumor radioresistance

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Bochet, Ludivine; Meulle, Aline [Universite de Toulouse, UPS, F-31077 Toulouse Cedex (France); CNRS, IPBS (Institut de Pharmacologie et de Biologie Structurale), 205 route de Narbonne, BP 64182, F-31077 Toulouse Cedex (France); Institut National de la Sante et de la Recherche Medicale, INSERM U1048, 1 Avenue du Pr Jean Poulhes, BP 84225, F-31432 Toulouse Cedex (France); Imbert, Sandrine [CNRS, IPBS (Institut de Pharmacologie et de Biologie Structurale), 205 route de Narbonne, BP 64182, F-31077 Toulouse Cedex (France); Salles, Bernard [Universite de Toulouse, UPS, F-31077 Toulouse Cedex (France); CNRS, IPBS (Institut de Pharmacologie et de Biologie Structurale), 205 route de Narbonne, BP 64182, F-31077 Toulouse Cedex (France); Valet, Philippe [Universite de Toulouse, UPS, F-31077 Toulouse Cedex (France); Institut National de la Sante et de la Recherche Medicale, INSERM U1048, 1 Avenue du Pr Jean Poulhes, BP 84225, F-31432 Toulouse Cedex (France); Muller, Catherine, E-mail: muller@ipbs.fr [Universite de Toulouse, UPS, F-31077 Toulouse Cedex (France); CNRS, IPBS (Institut de Pharmacologie et de Biologie Structurale), 205 route de Narbonne, BP 64182, F-31077 Toulouse Cedex (France)

2011-07-22

Highlights: {yields} Tumor-surrounding adipocytes contribute to breast cancer progression. {yields} Breast tumor cells previously co-cultivated with mature adipocytes exhibit radioresistance. {yields} Increased in Chk1 phosphorylation is observed in irradiated co-cultivated tumor cells. {yields} IL-6 is over-expressed in tumor cells co-cultivated with adipocytes. {yields} IL-6 exposure confers increased Chk1 phosphorylation and radioresistance in tumor cells. -- Abstract: Mature adipocytes are excellent candidates to influence tumor behavior through heterotypic signaling processes since these cells produce hormones, growth factors, cytokines and other molecules, a heterogeneous group of molecules named adipokines. Using a 2D coculture system, we demonstrate that breast tumor cells previously co-cultivated with mature adipocytes exhibit radioresistance and an earlier and higher increase in the effector kinase Chk1, a phenotype that was associated with decreased cell death as compared to tumor cells grown alone. Interestingly, the adipocytes-induced tumor changes taking place during the coculture time preceding the exposure to IR were sufficient to confer the radioresistant effect. Notorious among the changes brought by adipocytes was the significant increase of IL-6 expression in tumor cells, whose activity may well account for the observed tumor cell protection from IR toxicity. Indeed, our data confirmed the protective role of this cytokine as tumor cells incubated after irradiation with recombinant IL-6 exhibit an increased in Chk1 phosphorylation and a radioresistant phenotype, thus far recapitulating the effects observed in the presence of adipocytes. Our current study sheds light on a new role of tumor-surrounding adipocytes in fostering a radioresistant phenotype in breast tumors, a finding that might have important clinical implications in obese patients that frequently exhibit aggressive diseases.

Metabolism of indole alkaloid tumor promoter, (-)-indolactam V, which has the fundamental structure of teleocidins, by rat liver microsomes

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Hagiwara, N.; Irie, K.; Tokuda, H.; Koshimizu, K.

1987-07-01

Metabolic activation and/or deactivation of indole alkaloid tumor promoter, (-)-indolactam V (ILV), was examined using rat liver microsomes. Reaction of ILV with the microsomes supplemented with NADPH and MgCl/sub 2/ gave three major metabolites, which were identified as (-)-N13-desmethylindolactam V and two diastereomers of (-)-2-oxyindolactam V at C-3. The tumor-promoting activities of these metabolites were evaluated by induction of Epstein-Barr virus early antigen and inhibition of specific binding of (/sup 3/H)-12-O-tetradecanoylphorbol-13-acetate to a mouse epidermal particulate fraction, and proved to be conspicuously lower than that of ILV. These results demonstrate that the metabolism of ILV results in detoxification, and that it itself is the tumor-promoting entity. Studies on the enzymes concerned with this metabolism suggested the involvement of cytochrome P-450-containing mixed-function oxidases. Similar deactivation seems to be possible by skin, where the mixed-function oxidases are known to exist.

Platelets promote tumor growth and metastasis via direct interaction between Aggrus/podoplanin and CLEC-2.

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Satoshi Takagi

Full Text Available The platelet aggregation-inducing factor Aggrus, also known as podoplanin, is frequently upregulated in several types of tumors and enhances hematogenous metastasis by interacting with and activating the platelet receptor CLEC-2. Thus, Aggrus-CLEC-2 binding could be a therapeutic molecular mechanism for cancer therapy. We generated a new anti-human Aggrus monoclonal antibody, MS-1, that suppressed Aggrus-CLEC-2 binding, Aggrus-induced platelet aggregation, and Aggrus-mediated tumor metastasis. Interestingly, the MS-1 monoclonal antibody attenuated the growth of Aggrus-positive tumors in vivo. Moreover, the humanized chimeric MS-1 antibody, ChMS-1, also exhibited strong antitumor activity against Aggrus-positive lung squamous cell carcinoma xenografted into NOD-SCID mice compromising antibody-dependent cellular cytotoxic and complement-dependent cytotoxic activities. Because Aggrus knockdown suppressed platelet-induced proliferation in vitro and tumor growth of the lung squamous cell carcinoma in vivo, Aggrus may be involved in not only tumor metastasis but also tumor growth by promoting platelet-tumor interaction, platelet activation, and secretion of platelet-derived factors in vivo. Our results indicate that molecular target drugs inhibiting specific platelet-tumor interactions can be developed as antitumor drugs that suppress both metastasis and proliferation of tumors such as lung squamous cell carcinoma.

Studies on the utility and mechanism of the V-79 cell metabolic cooperation assay for tumor promoters

International Nuclear Information System (INIS)

Hartman, T.G.

1985-01-01

Cigarette smoke condensate and its fractions were tested for activity in the V-79 Metabolic Cooperation Assay to determine the usefulness of the assay for analysis of a complex mixture and to compare the results obtained with previously conducted in vivo promoter assays. The whole condensate and several of its fractions were positive in the assay. In general, the Metabolic Cooperation Assay results were comparable to previously published results obtained on mouse skin. The effect of cell density, phorbol 12-myrystate-13-acetate (PMA) exposure time, concentration, pre-exposure and binding activity on the recovery of mutant V-79 Chinese hamster lung fibroblasts in the Metabolic Cooperation Assay was determined. A PMA exposure interval of only 1 minute resulted in maximum recovery of mutant cells. PMA began to inhibit metabolic cooperation at an exposure concentration of 0.1 ng/ml. Pre-exposure of cells to PMA increased the recovery of both post-PMA-treated and non-treated mutant cells in a dose-dependent manner. 3 H-PMA was rapidly bound to or taken up by the V-79 cells under assay conditions. The effect of calcium antagonists and representative compounds from several classes of anti-promoters including anti-inflammatory sterols, protease inhibitors, retinoids and cyclic nucleotides on metabolic determined. Each compound was tested for its effect on metabolic cooperation and also for its ability to reverse or modify the inhibitory properties of PMA on inter-cellular communication. Of all the compounds tested only cyclic adenosine monophosphate (cAMP) was able to antagonize the inhibitory effect of PMA

Mesenchymal Stem Cells Promote Pancreatic Tumor Growth by Inducing Alternative Polarization of Macrophages

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Esha Mathew

2016-03-01

Significance: Targeting the stroma is emerging as a new paradigm in pancreatic cancer; however, efforts to that effect are hampered by our limited understanding of the nature and function of stromal components. Here, we uncover previously unappreciated heterogeneity within the stroma and identify interactions among stromal components that promote tumor growth and could be targeted therapeutically.

A novel mechanism of skin tumor promotion involving interferon-gamma (IFNγ)/signal transducer and activator of transcription-1 (Stat1) signaling.

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Bozeman, Ronald; Abel, Erika L; Macias, Everardo; Cheng, Tianyi; Beltran, Linda; DiGiovanni, John

2015-08-01

The current study was designed to explore the role of signal transducer and activator of transcription 1 (Stat1) during tumor promotion using the mouse skin multistage carcinogenesis model. Topical treatment with both 12-O-tetradecanoylphorbol-13-acetate (TPA) and 3-methyl-1,8-dihydroxy-9-anthrone (chrysarobin or CHRY) led to rapid phosphorylation of Stat1 on both tyrosine (Y701) and serine (S727) residues in epidermis. CHRY treatment also led to upregulation of unphosphorylated Stat1 (uStat1) at later time points. CHRY treatment also led to upregulation of interferon regulatory factor 1 (IRF-1) mRNA and protein, which was dependent on Stat1. Further analyses demonstrated that topical treatment with CHRY but not TPA upregulated interferon-gamma (IFNγ) mRNA in the epidermis and that the induction of both IRF-1 and uStat1 was dependent on IFNγ signaling. Stat1 deficient (Stat1(-/-) ) mice were highly resistant to skin tumor promotion by CHRY. In contrast, the tumor response (in terms of both papillomas and squamous cell carcinomas) was similar in Stat1(-/-) mice and wild-type littermates with TPA as the promoter. Maximal induction of both cyclooxygenase-2 and inducible nitric oxide synthase in epidermis following treatment with CHRY was also dependent on the presence of functional Stat1. These studies define a novel mechanism associated with skin tumor promotion by the anthrone class of tumor promoters involving upregulation of IFNγ signaling in the epidermis and downstream signaling through activated (phosphorylated) Stat1, IRF-1 and uStat1. © 2014 Wiley Periodicals, Inc.

Phosphorylation of stress protein pp80 is related to promotion of transformation

International Nuclear Information System (INIS)

Smith, B.M.; Gindhart, T.D.; Hirano, K.; Colburn, N.H.

1986-01-01

The JB6 mouse epidermal cell system is an in vitro model of late stage promotion, and includes cell lines sensitive (P+) or resistant (P-) to phorbol ester-induced anchorage independent transformation, and transformed (T/sub x/) lines. Certain promoter-induced changes in phosphoproteins, identified by gel electrophoresis, are unique to cells of one phenotype, and occur only with specific promoters. An 80Kd protein is inversely correlated with phenotype: P- cells have a constitutively higher level (p 35 S-methionine. pp80 shares properties with the 80Kd heat stress protein: molecular weight relative abundance, and isoelectric point (4.5). Pharmacological analogs of calcium, the lanthanides, promote transformation of JB6 cells, but have no effect on phosphorylation of the 80Kd protein. If pp80 is on the promotion pathway, it is limited to a specific subset of transformation promoters

Stimulation of prostaglandin E2 production by phorbol esters and epidermal growth factor in porcine thyroid cells

International Nuclear Information System (INIS)

Kasai, K.; Hiraiwa, M.; Emoto, T.; Akimoto, K.; Takaoka, T.; Shimoda, S.I.

1987-01-01

Effects of phorbol esters and epidermal growth factor (EGF) on prostaglandin E 2 production by cultured porcine thyroid cells were examined. Both phorbol 12-myristate 13-acetate (PMA) and EGF stimulated prostaglandin E 2 production by the cells in dose related fashion. PMA stimulated prostaglandin E 2 production over fifty-fold with the dose of 10 -7 M compared with control. EGF (10 -7 M) also stimulated it about ten-fold. The ED 50 values of PMA and EGF were respectively around 1 x 10 -9 M and 5 x 10 -10 M. Thyroid stimulating hormone (TSH), however, did not stimulate prostaglandin E 2 production from 1 to 24-h incubation. The release of radioactivity from [ 3 H]-arachidonic acid prelabeled cells was also stimulated by PMA and EGF, but not by TSH. These results indicate that both PMA and EGF are potent stimulators of prostaglandin E 2 production, associated with the activity to stimulate arachidonic acid release in porcine thyroid cells. 36 references, 2 figures, 1 table

Cycling Hypoxia Induces a Specific Amplified Inflammatory Phenotype in Endothelial Cells and Enhances Tumor-Promoting Inflammation In Vivo

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Céline Tellier

2015-01-01

Full Text Available Abnormal architecture of the tumor blood network, as well as heterogeneous erythrocyte flow, leads to temporal fluctuations in tissue oxygen tension exposing tumor and stromal cells to cycling hypoxia. Inflammation is another feature of tumor microenvironment and is considered as a new enabling characteristic of tumor progression. As cycling hypoxia is known to participate in tumor aggressiveness, the purpose of this study was to evaluate its role in tumor-promoting inflammation. Firstly, we assessed the impact of cycling hypoxia in vitro on endothelial inflammatory response induced by tumor necrosis factor α. Results showed that endothelial cells exposed to cycling hypoxia displayed an amplified proinflammatory phenotype, characterized by an increased expression of inflammatory cytokines, namely, interleukin (IL-6 and IL-8; by an increased expression of adhesion molecules, in particular intercellular adhesion molecule–1 (ICAM-1; and consequently by an increase in THP-1 monocyte adhesion. This exacerbation of endothelial inflammatory phenotype occurs through nuclear factor–κB overactivation. Secondly, the role of cycling hypoxia was studied on overall tumor inflammation in vivo in tumor-bearing mice. Results showed that cycling hypoxia led to an enhanced inflammation in tumors as prostaglandin-endoperoxide synthase 2 (PTGS2, IL-6, CXCL1 (C-X-C motif ligand 1, and macrophage inflammatory protein 2 (murine IL-8 functional homologs mRNA expression was increased and as a higher leukocyte infiltration was evidenced. Furthermore, cycling hypoxia–specific inflammatory phenotype, characterized by a simultaneous (baculoviral inhibitor of apoptosis repeat-containing 5low/PTGS2high/ICAM-1high/IL-6high/IL-8high expression, is associated with a poor prognosis in human colon cancer. This new phenotype could thus be used in clinic to more precisely define prognosis for colon cancer patients. In conclusion, our findings evidenced for the first time the

FGFR2 promotes breast tumorigenicity through maintenance of breast tumor-initiating cells.

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Sungeun Kim

Full Text Available Emerging evidence suggests that some cancers contain a population of stem-like TICs (tumor-initiating cells and eliminating TICs may offer a new strategy to develop successful anti-cancer therapies. As molecular mechanisms underlying the maintenance of the TIC pool are poorly understood, the development of TIC-specific therapeutics remains a major challenge. We first identified and characterized TICs and non-TICs isolated from a mouse breast cancer model. TICs displayed increased tumorigenic potential, self-renewal, heterogeneous differentiation, and bipotency. Gene expression analysis and immunostaining of TICs and non-TICs revealed that FGFR2 was preferentially expressed in TICs. Loss of FGFR2 impaired self-renewal of TICs, thus resulting in marked decreases in the TIC population and tumorigenic potential. Restoration of FGFR2 rescued the defects in TIC pool maintenance, bipotency, and breast tumor growth driven by FGFR2 knockdown. In addition, pharmacological inhibition of FGFR2 kinase activity led to a decrease in the TIC population which resulted in suppression of breast tumor growth. Moreover, human breast TICs isolated from patient tumor samples were found enriched in a FGFR2+ population that was sufficient to initiate tumor growth. Our data suggest that FGFR2 is essential in sustaining the breast TIC pool through promotion of self-renewal and maintenance of bipotent TICs, and raise the possibility of FGFR2 inhibition as a strategy for anti-cancer therapy by eradicating breast TICs.

Melanoma cell-derived exosomes promote epithelial-mesenchymal transition in primary melanocytes through paracrine/autocrine signaling in the tumor microenvironment

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Xiao, Deyi; Barry, Samantha; Kmetz, Daniel; Egger, Michael; Pan, Jianmin; Rai, Shesh N; Qu, Jifu; McMasters, Kelly M.; Hao, Hongying

2016-01-01

The tumor microenvironment is abundant with exosomes that are secreted by the cancer cells themselves. Exosomes are nanosized, organelle-like membranous structures that are increasingly being recognized as major contributors in the progression of malignant neoplasms. A critical element in melanoma progression is its propensity to metastasize, but little is known about how melanoma cell-derived exosomes modulate the microenvironment to optimize conditions for tumor progression and metastasis. Here, we provide evidence that melanoma cell-derived exosomes promote phenotype switching in primary melanocytes through paracrine/autocrine signaling. We found that the mitogen-activated protein kinase (MAPK) signaling pathway was activated during the exosome-mediated epithelial-to-mesenchymal transition (EMT)-resembling process, which promotes metastasis. Let-7i, an miRNA modulator of EMT, was also involved in this process. We further defined two other miRNA modulators of EMT (miR-191 and let-7a) in serum exosomes for differentiating stage I melanoma patients from non-melanoma subjects. These results provide the first strong molecular evidence that melanoma cell-derived exosomes promote the EMT-resembling process in the tumor microenvironment. Thus, novel strategies targeting EMT and modulating the tumor microenvironment may emerge as important approaches for the treatment of metastatic melanoma. PMID:27063098

MicroRNA-103 Promotes Colorectal Cancer by Targeting Tumor Suppressor DICER and PTEN

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Li Geng

2014-05-01

Full Text Available MicroRNAs (miRNAs are a class of small, noncoding RNAs that act as key regulators in various physiological and pathological processes. However, the regulatory mechanisms for miRNAs in colorectal cancer remain largely unknown. Here, we found that miR-103 is up-regulated in colorectal cancer and its overexpression is closely associated with tumor proliferation and migration. In addition, repressing the expression of miR-103 apparently inhibits colorectal cancer cell proliferation and migration in vitro and HCT-116 xenograft tumor growth in vivo. Subsequent software analysis and dual-luciferase reporter assay identified two tumor suppressor genes DICER and PTEN as direct targets of miR-103, and up-regulation of DICER and PTEN obtained similar results to that occurred in the silencing of miR-103. In addition, restoration of DICER and PTEN can inhibit miR-103-induced colorectal cancer cell proliferation and migration. Our data collectively demonstrate that miR-103 is an oncogene miRNA that promotes colorectal cancer proliferation and migration through down-regulation of the tumor suppressor genes DICER and PTEN. Thus, miR-103 may represent a new potential diagnostic and therapeutic target for colorectal cancer treatment.

Inhibition of CD147 expression promotes chemosensitivity in HNSCC cells by deactivating MAPK/ERK signaling pathway.

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Ma, Chao; Wang, Jianqi; Fan, Longkun; Guo, Yanjun

2017-02-01

Head and neck squamous cell carcinoma (HNSCC) is one of the most common cancers in the world. CD147, a transmembrane glycoprotein, has been reported to be correlated with cancer progression, metastasis, and chemoresistance in various cancers. In this study, we aimed to investigate the mechanism of CD147 in regulating drug resistance in HNSCC cells. qRT-PCR were used to evaluated the expression of CD147 in 57 HNSCC tumorous tissues and 2 cell lines. Increased expression of CD147 was found in most HNSCC samples, and the expression level of CD147 was correlated with multidrug resistance. CD147 RNA silencing decreased the chemoresistance of HNSCC cells by deactivating MAPK/ERK signaling pathway. Further investigation revealed that either rescue expression of CD147 or treatment of MAPK/ERK activator phorbol 12-myristate 13-acetate (PMA) in CD147 knockdown CRC cell line attenuated the decreased chemoresistance in CD147 knockdown cells. Taken together, our results suggest that CD147 promotes chemoresistance by activating MAPK/ERK signaling pathway in HNSCC. Copyright © 2017. Published by Elsevier Inc.

Chronic alcohol intake promotes tumor growth in a diethylnitrosamine-induced hepatocarcinogenesis mouse model through increased Wnt/Beta-catenin signaling

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Ethanol (EtOH) metabolism is involved in both initiating and promoting mechanisms in hepatocellular carcinoma progression in chronic alcoholics. In this study, we developed a mouse model to test the hypothesis that chronic EtOH consumption promotes tumor growth irrespective of EtOH-related initiati...

Cysteine cathepsins B and X promote epithelial-mesenchymal transition of tumor cells.

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Mitrović, Ana; Pečar Fonović, Urša; Kos, Janko

2017-09-01

Cathepsins B and X are lysosomal cysteine carboxypeptidases suggested as having a redundant role in cancer. They are involved in a number of processes leading to tumor progression but their role in the epithelial-mesenchymal transition (EMT) remains unknown. We have investigated the contribution of both cathepsins B and X in EMT using tumor cell lines differing in their expression of epithelial and mesenchymal markers and cell morphology. Higher levels of both cathepsins are shown to promote EMT and are associated with the mesenchymal-like cell phenotype. Moreover, simultaneous knockdown of the two peptidases triggers a reverse, mesenchymal to epithelial transition. Of the two cathepsins, cathepsin B appears to be the stronger promotor of EMT. Furthermore, we evaluated the involvement of cathepsin B and X in the transforming growth factor-β1 (TGF-β1) signaling pathway, one of the key signaling mechanisms triggering EMT in cancer. In MCF-7 cells the expression of cathepsin B was shown to depend on their activation with TGF-β1 while, for cathepsin X, a TGF-β1 independent mechanism of induction during EMT is indicated. EMT is thus shown to be another mechanism linking cathepsins B and X with tumor progression. With silencing of their expression or inhibition of enzymatic activity, the tumor cells could be reverted to less aggressive epithelial-like phenotype. Copyright © 2017 Elsevier GmbH. All rights reserved.

The phorbol ester fraction from Jatropha curcas seed oil: potential and limits for crop protection against insect pests.

Science.gov (United States)

Ratnadass, Alain; Wink, Michael

2012-11-30

The physic nut shrub, Jatropha curcas (Euphorbiaceae), has been considered as a "miracle tree", particularly as a source of alternate fuel. Various extracts of the plant have been reported to have insecticidal/acaricidal or molluscicidal/anthelminthic activities on vectors of medical or veterinary interest or on agricultural or non-agricultural pests. Among those extracts, the phorbol ester fraction from seed oil has been reported as a promising candidate for use as a plant-derived protectant of a variety of crops, from a range of pre-harvest and post-harvest insect pests. However, such extracts have not been widely used, despite the "boom" in the development of the crop in the tropics during recent years, and societal concerns about overuse of systemic chemical pesticides. There are many potential explanations to such a lack of use of Jatropha insecticidal extracts. On the one hand, the application of extracts potentially harmful to human health on stored food grain, might not be relevant. The problem of decomposition of phorbol esters and other compounds toxic to crop pests in the field needing further evaluation before such extracts can be widely used, may also be a partial explanation. High variability of phorbol ester content and hence of insecticidal activity among physic nut cultivars/ecotypes may be another. Phytotoxicity to crops may be further limitation. Apparent obstacles to a wider application of such extracts are the costs and problems involved with registration and legal approval. On the other hand, more studies should be conducted on molluscicidal activity on slugs and land snails which are major pests of crops, particularly in conservation agriculture systems. Further evaluation of toxicity to natural enemies of insect pests and studies on other beneficial insects such as pollinators are also needed.

The Phorbol Ester Fraction from Jatropha curcas Seed Oil: Potential and Limits for Crop Protection against Insect Pests

Science.gov (United States)

Ratnadass, Alain; Wink, Michael

2012-01-01

The physic nut shrub, Jatropha curcas (Euphorbiaceae), has been considered as a “miracle tree”, particularly as a source of alternate fuel. Various extracts of the plant have been reported to have insecticidal/acaricidal or molluscicidal/anthelminthic activities on vectors of medical or veterinary interest or on agricultural or non-agricultural pests. Among those extracts, the phorbol ester fraction from seed oil has been reported as a promising candidate for use as a plant-derived protectant of a variety of crops, from a range of pre-harvest and post-harvest insect pests. However, such extracts have not been widely used, despite the “boom” in the development of the crop in the tropics during recent years, and societal concerns about overuse of systemic chemical pesticides. There are many potential explanations to such a lack of use of Jatropha insecticidal extracts. On the one hand, the application of extracts potentially harmful to human health on stored food grain, might not be relevant. The problem of decomposition of phorbol esters and other compounds toxic to crop pests in the field needing further evaluation before such extracts can be widely used, may also be a partial explanation. High variability of phorbol ester content and hence of insecticidal activity among physic nut cultivars/ecotypes may be another. Phytotoxicity to crops may be further limitation. Apparent obstacles to a wider application of such extracts are the costs and problems involved with registration and legal approval. On the other hand, more studies should be conducted on molluscicidal activity on slugs and land snails which are major pests of crops, particularly in conservation agriculture systems. Further evaluation of toxicity to natural enemies of insect pests and studies on other beneficial insects such as pollinators are also needed. PMID:23203190

Coordinate viral induction of tumor necrosis factor α and interferon β in human B cells and monocytes

International Nuclear Information System (INIS)

Goldfeld, A.E.; Maniatis, T.

1989-01-01

Human tumor necrosis factor α (TNF-α) gene expression can be induced primarily in cells of the monocyte/macrophage lineage by a variety of inducers, including lipopolysaccharide, phorbol esters such as phorbol 12-myristate 13-acetate, and virus or synthetic double-stranded RNA [poly(I)·poly(C)]. In this paper the authors show that the TNF-α gene also responds to virus and phorbol 12-myristate 13-acetate in B lymphocytes and that virus is the most potent inducer of TNF-α mRNA in both monocyte and B-cell lines. In addition, they show that viral infection coinduces the expression of TNF-α and interferon β mRNA and that viral induction of both genes is blocked by the kinase inhibitor 2-aminopurine. Inhibition of protein synthesis with cycloheximide had no effect on mRNA expression of the genes in one of three cell lines tested (U937) but blocked the viral induction of both genes in another (Namalwa). Thus, the regulatory factors required for mRNA induction of both genes are present prior to the addition of virus in U937 but not in Namalwa cells. However, in a third cell line (JY), cycloheximide blocked viral induction of the interferon β gene but not the TNF-α gene. Taken together, these observations suggest that viral induction of TNF-α and interferon β gene expression may involve overlapping pathways with both common and distinct regulatory factors

Bio-detoxification of phorbol esters and other anti-nutrients of Jatropha curcas seed cake by fungal cultures using solid-state fermentation.

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Sharath, B S; Mohankumar, B V; Somashekar, D

2014-03-01

Jatropha seed cake, a byproduct after biodiesel extraction, has several anti-nutrients and toxins. Solid-state fermentation was carried out for the detoxification of the Jatropha seed cake (JSC) using different fungal cultures. The reduction in the anti-nutritional components such as tannins, phytates, saponins, lectin and protease inhibitor, and phorbol esters on 6th, 9th, and 12th day of fermentation was analyzed. The phorbol ester content in the unfermented JSC was 0.83 mg/g, and the maximum degradation of phorbol esters to the extent of 75% was observed in the case of JSC fermented with Cunninghamella echinulata CJS-90. The phytate degradation in the fermented JSC was in the range of 65-96%. There was a gradual reduction of saponin content in the JSC from 6th to 12th day, and the reduction of saponin was in the range of 55-99% after solid-state fermentation. The trypsin inhibitor activity and lectin were 1,680 trypsin inhibitor units (TIU) per gram and 0.32 hemagglutinating unit in the unfermented JSC, respectively. Trypsin inhibitor activity and lectin could not be detected in JSC after 12th day of solid-state fermentation. Tannins accounted for 0.53% in unfermented JSC, and there was a marginal increase of tannins after solid-state fermentation. The results indicate that biological detoxification could be a promising method to reduce anti-nutritional compounds and toxins in the JSC.

Regulation of insulin-like growth factor I receptors on vascular smooth muscle cells by growth factors and phorbol esters.

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Ververis, J J; Ku, L; Delafontaine, P

1993-06-01

Insulin-like growth factor I (IGF I) is an important mitogen for vascular smooth muscle cells. To characterize regulation of vascular IGF I receptors, we performed radioligand displacement experiments using rat aortic smooth muscle cells (RASMs). Serum deprivation for 48 hours caused a 40% decrease in IGF I receptor number. Exposure of quiescent RASMs to platelet-derived growth factor (PDGF), fibroblast growth factor (FGF), or angiotensin II (Ang II) caused a 1.5-2.0-fold increase in IGF I receptors per cell. After FGF exposure, there was a marked increase in the mitogenic response to IGF I. IGF I downregulated its receptors in the presence of platelet-poor plasma. Stimulation of protein kinase C (PKC) by exposure of quiescent RASMs to phorbol 12-myristate 13-acetate caused a biphasic response in IGF I binding; there was a 42% decrease in receptor number at 45 minutes and a 238% increase at 24 hours. To determine the role of PKC in growth factor-induced regulation of IGF I receptors, we downregulated PKC by exposing RASMs to phorbol 12,13-dibutyrate (PDBu) for 48 hours. PDGF- and FGF- but not Ang II-mediated upregulation of IGF I receptors was completely inhibited in PDBu-treated cells. Thus, acute PKC activation by phorbol esters inhibits IGF I binding, whereas chronic PKC activation increases IGF I binding. PDGF and FGF but not Ang II regulate vascular IGF I receptors through a PKC-dependent pathway. These data provide new insights into the regulation of vascular smooth muscle cell IGF I receptors in vitro and are of potential importance in characterizing vascular proliferative responses in vivo.

Promoter hypermethylation of KLF4 inactivates its tumor suppressor function in cervical carcinogenesis.

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Wen-Ting Yang

Full Text Available OBJECTIVE: The KLF4 gene has been shown to be inactivated in cervical carcinogenesis as a tumor suppressor. However, the mechanism of KLF4 silencing in cervical carcinomas has not yet been identified. DNA methylation plays a key role in stable suppression of gene expression. METHODS: The methylation status of the KLF4 promoter CpG islands was analyzed by bisulfite sequencing (BSQ in tissues of normal cervix and cervical cancer. KLF4 gene expression was detected by RT-PCR, immunohistochemistry and western blot. KLF4 promoter methylation in cervical cancer cell line was determined by BSQ and methylation-specific polymerase chain reaction (MS-PCR. Cell proliferation ability was detected by cell growth curve and MTT assay. RESULTS: The methylated allele was found in 41.90% of 24 cervical cancer tissues but only in 11.11% of 11 normal cervix tissues (P<0.005. KLF4 mRNA levels were significantly reduced in cervical cancer tissues compared with normal cervix tissues (P<0.01 and KLF4 mRNA expression showed a significant negative correlation with the promoter hypermethylation (r = -0.486, P = 0.003. Cervical cancer cell lines also showed a significant negative correlation between KLF4 expression and hypermethylation. After treatment with the demethylating agent 5-Azacytidine (5-Aza, the expression of KLF4 in the cervical cancer cell lines at both mRNA and protein levels was drastically increased, the cell proliferation ability was inhibited and the chemosensitivity for cisplatin was significantly increased. CONCLUSION: KLF4 gene is inactivated by methylation-induced silencing mechanisms in a large subset of cervical carcinomas and KLF4 promoter hypermethylation inactivates the gene's function as a tumor suppressor in cervical carcinogenesis.

Celecoxib decreases growth and angiogenesis and promotes apoptosis in a tumor cell line resistant to chemotherapy

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Carlos Rosas

2014-01-01

Full Text Available BACKGROUND: During the last few years it has been shown in several laboratories that Celecoxib (Cx, a non-steroidal anti-inflammatory agent (NSAID normally used for pain and arthritis, mediates antitumor and antiangiogenic effects. However, the effects of this drug on a tumor cell line resistant to chemotherapeutical drugs used in cancer have not been described. Herein we evaluate the angiogenic and antitumor effects of Cx in the development of a drug-resistant mammary adenocarcinoma tumor (TA3-MTXR. RESULTS: Cx reduces angiogenesis in the chick embryonic chorioallantoic membrane assay (CAM, inhibits the growth and microvascular density of the murine TA3-MTXR tumor, reduces microvascular density of tumor metastases, promotes apoptosis and reduces vascular endothelial growth factor (VEGF production and cell proliferation in the tumor. CONCLUSION: The antiangiogenic and antitumor Cx effects correlate with its activity on other tumor cell lines, suggesting that Prostaglandins (PGs and VEGF production are involved. These results open the possibility of using Celecoxib combined with other experimental therapies, ideally aiming to get synergic effects.

MicroRNA-219-5p Promotes Tumor Growth and Metastasis of Hepatocellular Carcinoma by Regulating Cadherin 1

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Jing Yang

2018-01-01

Full Text Available MicroRNAs play significant roles in the development of cancer and may serve as promising therapeutic targets. In our previous work, miR-219-5p was identified as one of the important metastasis-related microRNAs in HCC. Here we demonstrated that miR-219-5p expression was elevated in HCC tissues and was associated with vascular invasion and dismal prognosis. In multivariate analysis, miR-219-5p was identified as an independent prognostic indicator for HCC patients. Functional mechanism analyses showed that miR-219-5p promoted HCC cell proliferation and invasion in in vitro, as well as in vivo, tumor growth and metastasis in nude mice models bearing human HCC tumors. In addition, cadherin 1 (CDH1 was revealed to be a downstream target of miR-219-5p in HCC cells. In conclusion, miR-219-5p promotes tumor growth and metastasis of HCC by regulating CDH1 and can serve as a prognostic marker for HCC patients.

ΔNp63α induces the expression of FAT2 and Slug to promote tumor invasion

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Dang, Tuyen T.; Westcott, Jill M.; Maine, Erin A.; Kanchwala, Mohammed; Xing, Chao; Pearson, Gray W.

2016-01-01

Tumor invasion can be induced by changes in gene expression that alter cell phenotype. The transcription factor ΔNp63α promotes basal-like breast cancer (BLBC) migration by inducing the expression of the mesenchymal genes Slug and Axl, which confers cells with a hybrid epithelial/mesenchymal state. However, the extent of the ΔNp63α regulated genes that support invasive behavior is not known. Here, using gene expression analysis, ChIP-seq, and functional testing, we find that ΔNp63α promotes BLBC motility by inducing the expression of the atypical cadherin FAT2, the vesicular binding protein SNCA, the carbonic anhydrase CA12, the lipid binding protein CPNE8 and the kinase NEK1, along with Slug and Axl. Notably, lung squamous cell carcinoma migration also required ΔNp63α dependent FAT2 and Slug expression, demonstrating that ΔNp63α promotes migration in multiple tumor types by inducing mesenchymal and non-mesenchymal genes. ΔNp63α activation of FAT2 and Slug influenced E-cadherin localization to cell-cell contacts, which can restrict spontaneous cell movement. Moreover, live-imaging of spheroids in organotypic culture demonstrated that ΔNp63α, FAT2 and Slug were essential for the extension of cellular protrusions that initiate collective invasion. Importantly, ΔNp63α is co-expressed with FAT2 and Slug in patient tumors and the elevated expression of ΔNp63α, FAT2 and Slug correlated with poor patient outcome. Together, these results reveal how ΔNp63α promotes cell migration by directly inducing the expression of a cohort of genes with distinct cellular functions and suggest that FAT2 is a new regulator of collective invasion that may influence patient outcome. PMID:27081041

Candidate Tumor-Suppressor Gene DLEC1 Is Frequently Downregulated by Promoter Hypermethylation and Histone Hypoacetylation in Human Epithelial Ovarian Cancer

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Joseph Kwong

2006-04-01

Full Text Available Suppression of ovarian tumor growth by chromosome 3p was demonstrated in a previous study. Deleted in Lung and Esophageal Cancer 1 (DLEC1 on 3p22.3 is a candidate tumor suppressor in lung, esophageal, and renal cancers. The potential involvement of DLEC1 in epithelial ovarian cancer remains unknown. In the present study, DLEC1 downregulation was found in ovarian cancer cell lines and primary ovarian tumors. Focus-expressed DLEC1 in two ovarian cancer cell lines resulted in 41% to 52% inhibition of colony formation. No chromosomal loss of chromosome 3p22.3 in any ovarian cancer cell line or tissue was found. Promoter hypermethylation of DLEC1 was detected in ovarian cancer cell lines with reduced DLEC1 transcripts, whereas methylation was not detected in normal ovarian epithelium and DLEC1-expressing ovarian cancer cell lines. Treatment with demethylating agent enhanced DLEC1 expression in 90% (9 of 10 of ovarian cancer cell lines. DLEC1 promoter methylation was examined in 13 high-grade ovarian tumor tissues with DLEC1 downregulation, in which 54% of the tumors showed DLEC1 methylation. In addition, 80% of ovarian cancer cell lines significantly upregulated DLEC1 transcripts after histone deacetylase inhibitor treatment. Therefore, our results suggested that DLEC1 suppressed the growth of ovarian cancer cells and that its downregulation was closely associated with promoter hypermethylation and histone hypoacetylation.

Genetic and Epigenetic Tumor Suppressor Gene Silencing Are Distinct Molecular Phenotypes Driven by Growth Promoting Mutations in Nonsmall Cell Lung Cancer

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Carmen J. Marsit

2008-01-01

Full Text Available Both genetic and epigenetic alterations characterize human nonsmall cell lung cancer (NSCLC, but the biological processes that create or select these alterations remain incompletely investigated. Our hypothesis posits that a roughly reciprocal relationship between the propensity for promoter hypermethylation and a propensity for genetic deletion leads to distinct molecular phenotypes of lung cancer. To test this hypothesis, we examined promoter hypermethylation of 17 tumor suppressor genes, as a marker of epigenetic alteration propensity, and deletion events at the 3p21 region, as a marker of genetic alteration. To model the complex biology between these somatic alterations, we utilized an item response theory model. We demonstrated that tumors exhibiting LOH at greater than 30% of informative alleles in the 3p21 region have a significantly reduced propensity for hypermethylation. At the same time, tumors with activating KRAS mutations showed a significantly increased propensity for hypermethylation of the loci examined, a result similar to what has been observed in colon cancer. These data suggest that NSCLCs have distinct epigenetic or genetic alteration phenotypes acting upon tumor suppressor genes and that mutation of oncogenic growth promoting genes, such as KRAS, is associated with the epigenetic phenotype.

[Multi-channel promotion of lung cancer progress by bone marrow derived mesenchymal stem cells in tumor microenvironment].

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Luo, D; Hu, S Y; Liu, G X

2018-02-23

Objective: To observe the growth and metastasis of lung cancer promoted by bone marrow derived mesenchymal stem cells (BMSCs) in tumor microenvironment and investigate the underlined mechanisms. Methods: Specific chemotaxis of BMSCs towards lung cancer was observed, and the tumor growth and metastasis were assessed in vivo . Furthermore, CD34 expression determined by immunohistochemistry was used to assess the microvessel density (MVD), and the expressions of GFP and α-SMA determined by immunofluorescence were used to detect the BMSCs derived mesenchymal cells. We investigated the effect of BMSCs on migration, invasion of lung cancer cells including A549 and H446 cells by using scratch assays and Transwell Assay in vitro. We also explored the effect of BMSCs on epithelial mesenchymal transition of A549 and H446 cells by observing the phenotype transition and E-Cadherin protein expression detected by Western blot. At last, we screened the potentially key soluble factors by enzyme linked immunosorbent assay (ELISA). Results: In NOD mice, labeled BMSCs injected via tail vein were special chemotaxis to tumor cells, and promoted the tumor growth [the time of tumor formation in A549+ BMSCs and A549 alone was (5.0±1.5) days and (10.0±3.6) days, respectively, P cell carcinoma and promoted the migration and invasion of lung cancer cells (the A of cells in the migrated lower chambers of A549+ BMSCs and A549 alone was 1.9±0.2 and 1.1±0.1, respectively, P cells in the migrated lower chambers of H446+ BMSCs and H446 alone was 1.9±0.3 and 0.9±0.2, respectively, P cell shape was longer and sharper, the intercellular junctions were reduced and the relative expression level of E-Cadherin protein in A549 co-cultured with BMDCs was 0.36, significantly down-regulated when compared to 0.55 of A549 alone ( P cells alone ( P <0.05). The concentration of IL-6 in the conditional medium of BMSCs, A549 co-cultured with BMSCs and H446 co-cultured with BMSCs was 910.5, 957.2, and 963

Internal radiotherapy of liver cancer with rat hepato-carcinoma-intestine-pancreas gene as a liver tumor-specific promoter

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Herve, J.; Cunha, A. Sa; Liu, B.; Valogne, Y.; Longuet, M.; Bregerie, O.; Guettier, C.; Samuel, D.; Brechot, C.; Faivre, J. [Hop Paul Brousse, INSERM, Hepatobiliary Ctr, U785, F-94800 Villejuif (France); Herve, J.; Cunha, A. Sa; Liu, B.; Valogne, Y.; Longuet, M.; Bregerie, O.; Guettier, C.; Samuel, D.; Brechot, C.; Faivre, J. [Univ Paris Sud, Fac Med, F-94800 Villejuif (France); Boisgard, R.; Tavitian, B. [INSERM, U803, F-91400 Orsay (France); Boisgard, R.; Tavitian, B. [CEA, Serv Hosp Frederic Joliot, Lab Imagerie Mol Expt, F-91400 Orsay (France); Roux, J.; Cales, P. [Univ Angers, UPRES EA 3859, Lab Hemodynam Interact Fibrose et Invas Tumorale H, Angers (France); Clerc, J. [Hop Cochin, AP HP, Dept Nucl Med, F-75014 Paris (France)

2008-07-01

The hepato-carcinoma-intestine-pancreas (HIP) gene, also called pancreatitis-associated protein-1 (PAP1) or Reg III {alpha}, is activated in most human hepatocellular carcinomas (HCCs) but not in normal liver, which suggests that HIP regulatory sequence could be used as efficient liver tumor-specific promoters to express a therapeutic polynucleotide in liver cancer. The sodium iodide sym-porter (NIS), which has recognized therapeutic and reporter gene properties, is appropriate to evaluate the transcriptional strength and specificity of the HIP promoter in HCC. For this purpose, we constructed a recombinant rat HIP-NIS adeno-viral vector (AdrHIP-NIS), and evaluated its performance as a mediator of selective radio-iodide uptake in tumor hepatocytes. Western blot, immunofluorescence, and iodide uptake assays were performed in AdrHIP-NIS-infected primary hepatocytes and transformed hepatic and non-hepatic cells. Nuclear imaging, tissue counting and immuno-histo-chemistry were performed in normal and HCC-bearing Wistar rats infected with AdrHIP-NIS intra-tumorally or via the hepatic artery. In AdrHIP-NIS-infected transformed hepatic cells, functional NIS was strongly expressed, as in cells infected with a cytomegalovirus-NIS vector. No NIS expression was found in AdrHIP-NIS-infected normal hepatocytes or transformed non-hepatic cells. In rats bearing multi-nodular HCC, AdrHIP-NIS triggered functional NIS expression that was preferential in tumor hepatocytes. Administration of 18 mCi of {sup 131}I resulted in the destruction of AdrHIP-NIS-injected nodules. This study has identified the rHIP regulatory sequence as a potent liver tumor-specific promoter for the transfer of therapeutic genes, and AdrHIP-NIS-mediated. {sup 131}I therapy as a valuable option for the treatment of multi-nodular HCC. (authors)

Internal radiotherapy of liver cancer with rat hepato-carcinoma-intestine-pancreas gene as a liver tumor-specific promoter

International Nuclear Information System (INIS)

Herve, J.; Cunha, A. Sa; Liu, B.; Valogne, Y.; Longuet, M.; Bregerie, O.; Guettier, C.; Samuel, D.; Brechot, C.; Faivre, J.; Herve, J.; Cunha, A. Sa; Liu, B.; Valogne, Y.; Longuet, M.; Bregerie, O.; Guettier, C.; Samuel, D.; Brechot, C.; Faivre, J.; Boisgard, R.; Tavitian, B.; Boisgard, R.; Tavitian, B.; Roux, J.; Cales, P.; Clerc, J.

2008-01-01

The hepato-carcinoma-intestine-pancreas (HIP) gene, also called pancreatitis-associated protein-1 (PAP1) or Reg III α, is activated in most human hepatocellular carcinomas (HCCs) but not in normal liver, which suggests that HIP regulatory sequence could be used as efficient liver tumor-specific promoters to express a therapeutic polynucleotide in liver cancer. The sodium iodide sym-porter (NIS), which has recognized therapeutic and reporter gene properties, is appropriate to evaluate the transcriptional strength and specificity of the HIP promoter in HCC. For this purpose, we constructed a recombinant rat HIP-NIS adeno-viral vector (AdrHIP-NIS), and evaluated its performance as a mediator of selective radio-iodide uptake in tumor hepatocytes. Western blot, immunofluorescence, and iodide uptake assays were performed in AdrHIP-NIS-infected primary hepatocytes and transformed hepatic and non-hepatic cells. Nuclear imaging, tissue counting and immuno-histo-chemistry were performed in normal and HCC-bearing Wistar rats infected with AdrHIP-NIS intra-tumorally or via the hepatic artery. In AdrHIP-NIS-infected transformed hepatic cells, functional NIS was strongly expressed, as in cells infected with a cytomegalovirus-NIS vector. No NIS expression was found in AdrHIP-NIS-infected normal hepatocytes or transformed non-hepatic cells. In rats bearing multi-nodular HCC, AdrHIP-NIS triggered functional NIS expression that was preferential in tumor hepatocytes. Administration of 18 mCi of 131 I resulted in the destruction of AdrHIP-NIS-injected nodules. This study has identified the rHIP regulatory sequence as a potent liver tumor-specific promoter for the transfer of therapeutic genes, and AdrHIP-NIS-mediated. 131 I therapy as a valuable option for the treatment of multi-nodular HCC. (authors)

Clinicopathologic Risk Factor Distributions for MLH1 Promoter Region Methylation in CIMP-Positive Tumors.

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Levine, A Joan; Phipps, Amanda I; Baron, John A; Buchanan, Daniel D; Ahnen, Dennis J; Cohen, Stacey A; Lindor, Noralane M; Newcomb, Polly A; Rosty, Christophe; Haile, Robert W; Laird, Peter W; Weisenberger, Daniel J

2016-01-01

The CpG island methylator phenotype (CIMP) is a major molecular pathway in colorectal cancer. Approximately 25% to 60% of CIMP tumors are microsatellite unstable (MSI-H) due to DNA hypermethylation of the MLH1 gene promoter. Our aim was to determine if the distributions of clinicopathologic factors in CIMP-positive tumors with MLH1 DNA methylation differed from those in CIMP-positive tumors without DNA methylation of MLH1. We assessed the associations between age, sex, tumor-site, MSI status BRAF and KRAS mutations, and family colorectal cancer history with MLH1 methylation status in a large population-based sample of CIMP-positive colorectal cancers defined by a 5-marker panel using unconditional logistic regression to assess the odds of MLH1 methylation by study variables. Subjects with CIMP-positive tumors without MLH1 methylation were significantly younger, more likely to be male, and more likely to have distal colon or rectal primaries and the MSI-L phenotype. CIMP-positive MLH1-unmethylated tumors were significantly less likely than CIMP-positive MLH1-methylated tumors to harbor a BRAF V600E mutation and significantly more likely to harbor a KRAS mutation. MLH1 methylation was associated with significantly better overall survival (HR, 0.50; 95% confidence interval, 0.31-0.82). These data suggest that MLH1 methylation in CIMP-positive tumors is not a completely random event and implies that there are environmental or genetic determinants that modify the probability that MLH1 will become methylated during CIMP pathogenesis. MLH1 DNA methylation status should be taken into account in etiologic studies. ©2015 American Association for Cancer Research.

Clinicopathological risk factor distributions for MLH1 promoter region methylation in CIMP positive tumors

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Levine, A. Joan; Phipps, Amanda I.; Baron, John A.; Buchanan, Daniel D.; Ahnen, Dennis J.; Cohen, Stacey A.; Lindor, Noralane M.; Newcomb, Polly A.; Rosty, Christophe; Haile, Robert W.; Laird, Peter W.; Weisenberger, Daniel J.

2015-01-01

Background The CpG Island Methylator Phenotype (CIMP) is a major molecular pathway in colorectal cancer (CRC). Approximately 25% to 60% of CIMP tumors are microsatellite unstable (MSI-H) due to DNA hypermethylation of the MLH1 gene promoter. Our aim was to determine if the distributions of clinicopathologic factors in CIMP-positive tumors with MLH1 DNA methylation differed from those in CIMP-positive tumors without DNA methylation of MLH1. Methods We assessed the associations between age, sex, tumor-site, MSI status BRAF and KRAS mutations and family CRC history with MLH1 methylation status in a large population-based sample of CIMP-positive CRCs defined by a 5-marker panel using unconditional logistic regression to assess the odds of MLH1 methylation by study variables. Results Subjects with CIMP-positive tumors without MLH1 methylation were significantly younger, more likely to be male, more likely to have distal colon or rectal primaries and the MSI-L phenotype. CIMP-positive MLH1-unmethylated tumors were significantly less likely than CIMP-positive MLH1-methylated tumors to harbor a BRAF V600E mutation and significantly more likely to harbor a KRAS mutation. MLH1 methylation was associated with significantly better overall survival (HR=0.50; 95% Confidence Interval (0.31, 0.82)). Conclusions These data suggest that MLH1 methylation in CIMP-positive tumors is not a completely random event and implies that there are environmental or genetic determinants that modify the probability that MLH1 will become methylated during CIMP pathogenesis. Impact MLH1 DNA methylation status should be taken into account in etiologic studies. PMID:26512054

Modulating effects of the protease inhibitor Antipain on x-ray induced transformations

International Nuclear Information System (INIS)

Borek, C.; Miller, R.C.

1979-01-01

Protease inhibitors have been shown to inhibit the expression of mutations in bacteria and to inhibit the tumor-promoting effect of phorbol esters in mice. We have investigated the effect of the protease inhibitor Antipain on cell transformation by x-irradiation in two in vitro systems; namely short-term cultures of freshly explanted hamster embryo cells and in the 10T1/2 cell line derived and cloned from C3H mouse embryo

Effects of 12-O-tetradecanoyl-phorbol-13-acetate [corrected] and sodium lauryl sulfate on the production and expression of cytokines and proto-oncogenes in photoaged and intrinsically aged human keratinocytes.

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Suh, D H; Youn, J I; Eun, H C

2001-11-01

Skin aging may be divided into photoaging and intrinsic aging. The purpose of this study was to investigate the effects of 12-O-tetradecanoyl-phorbol-13-acetate and sodium lauryl sulfate on the production and expression of cytokines and proto-oncogenes in photoaged and intrinsically aged skin, compared with young skin. Keratinocytes were taken from newborns, young adults in their twenties, and from the forearm and thigh of volunteers in their fifties and seventies. Interleukin-1alpha and -6, and interleukin-1 receptor antagonist, c-fos and c-myc were measured after cultured keratinocytes had been treated with 12-O-tetradecanoyl-phorbol-13-acetate and sodium lauryl sulfate. There has been no report concerning the dependence of cytokine production by sodium lauryl sulfate upon photoaging and intrinsic aging. This study also involves the first investigation of the effects of aging on c-myc expression by 12-O-tetradecanoyl-phorbol-13-acetate treatment. Cytokine production decreased markedly with age. These results suggest the progressive decline of cellular function with age. The ratio of cytokine production in the irritant-treated group compared with that in the control group showed a different pattern in photoaging and intrinsic aging. With the significant difference between photoaging and intrinsic aging, T/C ratio decreased in interleukin-1alpha and interleukin-1 receptor antagonist upon aging, whereas it increased in interleukin-6. S/C ratio was uniquely elevated on photoaged skin in the 50 y age group. It is suggested that photoaged skin shows an exaggerated reaction to surfactant. Compared with the control, c-fos expression in 12-O-tetradecanoyl-phorbol-13-acetate-treated keratinocytes decreased with age in the thigh, but increased in the photoaged skin of forearm. The increased c-fos expression in 12-O-tetradecanoyl-phorbol-13-acetate-treated keratinocytes could be relevant for the predisposition of photoaged keratinocytes to malignant transformation.

Laser Therapy Inhibits Tumor Growth in Mice by Promoting Immune Surveillance and Vessel Normalization

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Giulia Ottaviani

2016-09-01

Full Text Available Laser therapy, recently renamed as photobiomodulation, stands as a promising supportive treatment for oral mucositis induced by oncological therapies. However, its mechanisms of action and, more importantly, its safety in cancer patients, are still unclear. Here we explored the anti-cancer effect of 3 laser protocols, set at the most commonly used wavelengths, in B16F10 melanoma and oral carcinogenesis mouse models. While laser light increased cell metabolism in cultured cells, the in vivo outcome was reduced tumor progression. This striking, unexpected result, was paralleled by the recruitment of immune cells, in particular T lymphocytes and dendritic cells, which secreted type I interferons. Laser light also reduced the number of highly angiogenic macrophages within the tumor mass and promoted vessel normalization, an emerging strategy to control tumor progression. Collectively, these results set photobiomodulation as a safety procedure in oncological patients and open the way to its innovative use for cancer therapy.

Fibroblast growth factor-2-induced host stroma reaction during initial tumor growth promotes progression of mouse melanoma via vascular endothelial growth factor A-dependent neovascularization.

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Tsunoda, Satoshi; Nakamura, Toshiyuki; Sakurai, Hiroaki; Saiki, Ikuo

2007-04-01

Fibroblast growth factor (FGF)-2 has been considered to play a critical role in neovascularization in several tumors; however, its precise role in tumor progression is not fully understood. In the present study, we have characterized the role of FGF-2 in B16-BL6 mouse melanoma cells, focusing on effects during the initial phase of tumor growth. FGF-2 was injected at the tumor inoculation site of dorsal skin during the initial phase. FGF-2 induced marked tumor growth and lymph node metastasis. This was well correlated with an increase in neovascularization in the host stroma. FGF-2 also recruited inflammatory and mesenchymal cells in host stroma. Marked tumor growth, pulmonary metastasis and intensive neovascularization in tumor parenchyma were also observed after a single injection of FGF-2 into the footpad inoculation site. In contrast, repeated injections of FGF-2 at a site remote from the footpad tumor were ineffective in promoting tumor growth and metastasis. These promoting activities of FGF-2 were blocked by local injections of a glucocorticoid hormone, suggesting that host inflammatory responses induced by FGF-2 are associated with FGF-2-induced tumor progression. In addition, although FGF-2 did not promote cellular proliferation and vascular endothelial growth factor A (VEGFA) mRNA expression in B16-BL6 cells in vitro, FGF-2 induced VEGFA expression in host stroma rather than tumor tissue, and local injections of a neutralizing antibody against VEGFA inhibited these activities of FGF-2 in vivo. These results indicate that abundant FGF-2 during the initial phase of tumor growth induces VEGFA-dependent intensive neovascularization in host stroma, and supports marked tumor growth and metastasis.

Anti-tumor effect of adenovirus-mediated suicide gene therapy under control of tumor-specific and radio-inducible chimeric promoter in combination with γ-ray irradiation in vivo

International Nuclear Information System (INIS)

Sun Wenjie; Yu Haijun; Xiongjie; Xu Yu; Liao Zhengkai; Zhou Fuxiang; Xie Conghua; Zhou Yunfeng

2011-01-01

Objective: To detect the selective inhibitory effects of irradiation plus adenovirus-mediated horseradish peroxidase (HRP)/indole-3-acetic acid (IAA) suicide gene system using tumor-specific and radio-inducible chimeric promoter on human hepatocellular carcinoma subcutaneously xenografted in nude mouse. Methods: Recombinant replicated-deficient adenovirus vector containing HRP gene and chimeric human telomerase reverse transcriptase (hTERT) promoter carrying 6 radio-inducible CArG elements was constructed. A human subcutaneous transplanting hepatocellular carcinoma (MHCC97 cell line) model was treated with γ-ray irradiation plus intra-tumor injections of adenoviral vector and intra-peritoneal injections of prodrug IAA. The change of tumor volume and tumor growth inhibiting rate, the survival time of nude mice, as well as histopathology of xenograft tumor and normal tissues were evaluated. Results: Thirty one days after the treatment, the relative tumor volumes in the negative, adenovirus therapy, irradiation, and combination groups were 49.23±4.55, 27.71±7.74, 28.53±10.48 and 11.58±3.23, respectively.There was a significantly statistical difference among them (F=16.288, P<0.01).The inhibition effect in the combination group was strongest as compared with that in other groups, and its inhibition ratio was 76.5%. The survival period extended to 43 d in the combination group, which showed a significantly difference with that in the control group (χ 2 =18.307, P<0.01). The area of tumors necrosis in the combination group was larger than that in the other groups, and the normal tissues showed no treatment-related toxic effect in all groups. However, multiple hepatocellular carcinoma metastases were observed in the liver in the control group, there were a few metastases in the monotherapy groups and no metastasis in the combination group. Conclusions: Adenovirus-mediated suicide gene therapy plus radiotherapy dramatically could inhibit tumor growth and prolong

Glycerol-3-phosphate Acyltransferase 1 Promotes Tumor Cell Migration and Poor Survival in Ovarian Carcinoma.

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Marchan, Rosemarie; Büttner, Bettina; Lambert, Jörg; Edlund, Karolina; Glaeser, Iris; Blaszkewicz, Meinolf; Leonhardt, Gregor; Marienhoff, Lisa; Kaszta, Darius; Anft, Moritz; Watzl, Carsten; Madjar, Katrin; Grinberg, Marianna; Rempel, Eugen; Hergenröder, Roland; Selinski, Silvia; Rahnenführer, Jörg; Lesjak, Michaela S; Stewart, Joanna D; Cadenas, Cristina; Hengstler, Jan G

2017-09-01

Glycerophosphodiesterase EDI3 (GPCPD1; GDE5; GDPD6) has been suggested to promote cell migration, adhesion, and spreading, but its mechanisms of action remain uncertain. In this study, we targeted the glycerol-3-phosphate acyltransferase GPAM along with choline kinase-α (CHKA), the enzymes that catabolize the products of EDI3 to determine which downstream pathway is relevant for migration. Our results clearly showed that GPAM influenced cell migration via the signaling lipid lysophosphatidic acid (LPA), linking it with GPAM to cell migration. Analysis of GPAM expression in different cancer types revealed a significant association between high GPAM expression and reduced overall survival in ovarian cancer. Silencing GPAM in ovarian cancer cells decreased cell migration and reduced the growth of tumor xenografts. In contrast to these observations, manipulating CHKA did not influence cell migration in the same set of cell lines. Overall, our findings show how GPAM influences intracellular LPA levels to promote cell migration and tumor growth. Cancer Res; 77(17); 4589-601. ©2017 AACR . ©2017 American Association for Cancer Research.

Phorbol 12-myristate 13-acetate enhances nm23 gene expression in murine melanocytes but not in syngeneic B16-BL6 melanoma variants.

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Huijzer, J C; McFarland, M; Niles, R M; Meadows, G G

1996-03-01

The nm23 gene has been described as a potential metastasis suppressor gene in certain rodent and human tumors. We previously demonstrated that tyrosine and phenylalanine restriction suppresses metastatic heterogeneity of B16-BL6 murine melanoma and selects for tumor variants with decreased metastatic potential. In this study, we investigated nm23 expression in the highly metastatic B16-BL6 (ND) melanoma, its nutritionally derived poorly metastatic (LT) variant, and the syngeneic non-tumorigenic Mel-ab melanocytes. No differences in nm23 expression were observed between ND and LT cells, and nm23 expression varied between different isolates. Previously, we showed that metastatic potential of 1-ND cells decreases and is not altered in 1-LT cells after prolonged in vitro cell passage; however, nm23 expression is equivalently increased by 2-fold. In 2-ND and 2-LT cells, expression of nm23 is not different at higher in vitro cell passage. Expression of nm23 decreased about 2-fold when phorbol 12-myristate 13-acetate (PMA) was removed from Mel-ab cells, which induces these cells to become quiescent. Although membrane-associated protein kinase C (PKC) activity decreased after prolonged PMA treatment in all cells, neither nm23 expression nor proliferation of ND and LT cells was affected by PMA. These data indicate that nm23 expression is related to proliferative activity rather than to the suppression of metastatic potential.

Key tumor suppressor genes inactivated by "greater promoter" methylation and somatic mutations in head and neck cancer

NARCIS (Netherlands)

Guerrero-Preston, Rafael; Michailidi, Christina; Marchionni, Luigi; Pickering, Curtis R.; Frederick, Mitchell J.; Myers, Jeffrey N.; Yegnasubramanian, Srinivasan; Hadar, Tal; Noordhuis, Maartje G.; Zizkova, Veronika; Fertig, Elana; Agrawal, Nishant; Westra, William; Koch, Wayne; Califano, Joseph; Velculescu, Victor E.; Sidransky, David

Tumor suppressor genes (TSGs) are commonly inactivated by somatic mutation and/or promoter methylation; yet, recent high-throughput genomic studies have not identified key TSGs inactivated by both mechanisms. We pursued an integrated molecular analysis based on methylation binding domain sequencing

Increased Serotonin Signaling Contributes to the Warburg Effect in Pancreatic Tumor Cells Under Metabolic Stress and Promotes Growth of Pancreatic Tumors in Mice.

Science.gov (United States)

Jiang, Shu-Heng; Li, Jun; Dong, Fang-Yuan; Yang, Jian-Yu; Liu, De-Jun; Yang, Xiao-Mei; Wang, Ya-Hui; Yang, Min-Wei; Fu, Xue-Liang; Zhang, Xiao-Xin; Li, Qing; Pang, Xiu-Feng; Huo, Yan-Miao; Li, Jiao; Zhang, Jun-Feng; Lee, Ho-Young; Lee, Su-Jae; Qin, Wen-Xin; Gu, Jian-Ren; Sun, Yong-Wei; Zhang, Zhi-Gang

2017-07-01

of 5-HT to be increased in human PDAC tissues compared with non-tumor pancreatic tissues, and PDAC cell lines compared with non-transformed pancreatic cells. Incubation of PDAC cell lines with 5-HT increased proliferation and prevented apoptosis. Agonists of HTR2B, but not other 5-HT receptors, promoted proliferation and prevented apoptosis of PDAC cells. Knockdown of HTR2B in PDAC cells, or incubation of cells with HTR2B inhibitors, reduced their growth as xenograft tumors in mice. We observed a correlation between 5-HT and glycolytic flux in PDAC cells; levels of metabolic enzymes involved in glycolysis, the phosphate pentose pathway, and hexosamine biosynthesis pathway increased significantly in PDAC cells following 5-HT stimulation. 5-HT stimulation led to formation of the HTR2B-LYN-p85 complex, which increased PI3K-Akt-mTOR signaling and the Warburg effect by increasing protein levels of MYC and HIF1A. Administration of SB204741 to KPC mice slowed growth and metabolism of established pancreatic tumors and prolonged survival of the mice. Human PDACs have increased levels of 5-HT, and PDAC cells increase expression of its receptor, HTR2B. These increases allow for tumor glycolysis under metabolic stress and promote growth of pancreatic tumors and PDAC xenograft tumors in mice. Copyright © 2017 AGA Institute. Published by Elsevier Inc. All rights reserved.

High-fat-diet-induced obesity causes an inflammatory and tumor-promoting microenvironment in the rat kidney

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Kerstin Stemmer

2012-09-01

Obesity and concomitant comorbidities have emerged as public health problems of the first order. For instance, obese individuals have an increased risk for kidney cancer. However, direct mechanisms linking obesity with kidney cancer remain elusive. We hypothesized that diet-induced obesity (DIO promotes renal carcinogenesis by inducing an inflammatory and tumor-promoting microenvironment. We compared chow-fed lean Wistar rats with those that were sensitive (DIOsens or partially resistant (DIOres to DIO to investigate the impact of body adiposity versus dietary nutrient overload in the development of renal preneoplasia and activation of tumor-promoting signaling pathways. Our data clearly show a correlation between body adiposity, the severity of nephropathy, and the total number and incidence of preneoplastic renal lesions. However, similar plasma triglyceride, plasma free fatty acid and renal triglyceride levels were found in chow-fed, DIOres and DIOsens rats, suggesting that lipotoxicity is not a critical contributor to the renal pathology. Obesity-related nephropathy was further associated with regenerative cell proliferation, monocyte infiltration and higher renal expression of monocyte chemotactic protein-1 (MCP-1, interleukin (IL-6, IL-6 receptor and leptin receptor. Accordingly, we observed increased signal transducer and activator of transcription 3 (STAT3 and mammalian target of rapamycin (mTOR phosphorylation in tubules with preneoplastic phenotypes. In summary, our results demonstrate that high body adiposity induces an inflammatory and proliferative microenvironment in rat kidneys that promotes the development of preneoplastic lesions, potentially via activation of the STAT3 and mTOR signaling pathways.

TFPI-2 is a putative tumor suppressor gene frequently inactivated by promoter hypermethylation in nasopharyngeal carcinoma

International Nuclear Information System (INIS)

Wang, Shumin; Ma, Ning; Murata, Mariko; Huang, Guangwu; Zhang, Zhe; Xiao, Xue; Zhou, Xiaoying; Huang, Tingting; Du, Chunping; Yu, Nana; Mo, Yingxi; Lin, Longde; Zhang, Jinyan

2010-01-01

Epigenetic silencing of tumor suppressor genes play important roles in NPC tumorgenesis. Tissue factor pathway inhibitor-2 (TFPI-2), is a protease inhibitor. Recently, TFPI-2 was suggested to be a tumor suppressor gene involved in tumorigenesis and metastasis in some cancers. In this study, we investigated whether TFPI-2 was inactivated epigenetically in nasopharyngeal carcinoma (NPC). Transcriptional expression levels of TFPI-2 was evaluated by RT-PCR. Methylation status were investigated by methylation specific PCR and bisulfate genomic sequencing. The role of TFPI-2 as a tumor suppressor gene in NPC was addressed by re-introducing TFPI-2 expression into the NPC cell line CNE2. TFPI-2 mRNA transcription was inactivated in NPC cell lines. TFPI-2 was aberrantly methylated in 66.7% (4/6) NPC cell lines and 88.6% (62/70) of NPC primary tumors, but not in normal nasopharyngeal epithelia. TFPI-2 expression could be restored in NPC cells after demethylation treatment. Ectopic expression of TFPI-2 in NPC cells induced apoptosis and inhibited cell proliferation, colony formation and cell migration. Epigenetic inactivation of TFPI-2 by promoter hypermethylation is a frequent and tumor specific event in NPC. TFPI-2 might be considering as a putative tumor suppressor gene in NPC

Postmenopausal obesity promotes tumor angiogenesis and breast cancer progression in mice.

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Gu, Jian-Wei; Young, Emily; Patterson, Sharla G; Makey, Kristina L; Wells, Jeremy; Huang, Min; Tucker, Kevan B; Miele, Lucio

2011-05-15

Obese postmenopausal women have a 50% higher risk of breast cancer than non-obese women. There is not an animal model that mimics postmenopausal obesity related to breast cancer progression. Using age-relevant C57BL/6 mice, this study determined whether postmenopausal obesity increases VEGF expression, tumor angiogenesis, and breast tumor growth. Ovariectomy (OVX) was performed in 12 sixty week-old female mice, then followed by a low-fat (5%, LF, n=6) or a high-fat (60%, HF, n=6) diet for 12 weeks. In the eighth week of the dietary program, 10(6) E0771 (mouse breast cancer) cells were injected in the left fourth mammary gland. Tumor size was monitored for 4 weeks. Body weights were monitored weekly. At the end of the experiment, blood samples, visceral fat and tumors were collected for measuring VEGF expression using ELISA and intratumoral microvessel density (IMD) using CD31 immunochemistry. Body weight was significantly increased in OVX/HF mice, compared to OVX/LF group (55.3±1.7 vs. 41.5±1.5 g; p < 0.01). There was a two-fold increase in the ratio of visceral fat/BW in OVX/HF mice, compared to those in OVX/LF group (0.062±0.005 vs. 0.032±0.003; p < 0.01). Postmenopausal obesity significantly increased breast tumor weight over the control (4.62±0.63 vs. 1.98±0.27 g; p < 0.01) and IMD (173±3.7 vs. 139±4.3 IM#/mm^2; p < 0.01). Tumor VEGF levels were higher in OVX/HF mice, compared to OVX/LF group (73.3±3.8 vs. 49.5±4.3 pg/mg protein; p < 0.01). Plasma VEGF levels (69±7.1 vs. 48±3.5 pg/ml) and visceral fat VEGF levels (424.4±39.5 vs. 208.5±22.4 pg/mg protein) were significantly increased in OVX/HF mice, compared to OVX/LF group, respectively (n=6; p < 0.01). Interestingly, adipose tissue primary culture showed that subcutaneous fat released more VEGF, compared to visceral fat (6.77±1.14 vs. 0.94±0.16 pg/mg tissue; n=6; p < 0.01). These findings support the hypothesis that postmenopausal obesity promotes tumor angiogenesis and breast cancer

Canonical and Non-Canonical NF-κB Signaling Promotes Breast Cancer Tumor-Initiating Cells

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Kendellen, Megan F.; Bradford, Jennifer W.; Lawrence, Cortney L.; Clark, Kelly S.; Baldwin, Albert S.

2014-01-01

Tumor-initiating cells (TICs) are a sub-population of cells that exhibit a robust ability to self-renew and contribute to the formation of primary tumors, the relapse of previously treated tumors, and the development of metastases. TICs have been identified in various tumors, including those of the breast, and are particularly enriched in the basal-like and claudin-low subtypes of breast cancer. The signaling pathways that contribute to the function and maintenance of TICs are under intense study. We explored the potential involvement of the NF-κB family of transcription factors in TICs in cell lines that are representative of basal-like and claudin-low breast cancer. NF-κB was found to be activated in breast cancer cells that form tumorspheres efficiently. Moreover, both canonical and non-canonical NF-κB signaling is required for these cells to self-renew in vitro and to form xenograft tumors efficiently in vivo using limiting dilutions of cells. Consistent with this, canonical and non-canonical NF-κB signaling is activated in TICs isolated from breast cancer cell lines. Experimental results indicate that NF-κB promotes the function of TICs by stimulating epithelial-to-mesenchymal transition (EMT) and by upregulating the expression of the inflammatory cytokines IL-1β and IL-6. The results suggest the use of NF-κB inhibitors for clinical therapy of certain breast cancers. PMID:23474754

TLX activates MMP-2, promotes self-renewal of tumor spheres in neuroblastoma and correlates with poor patient survival.

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Chavali, P L; Saini, R K R; Zhai, Q; Vizlin-Hodzic, D; Venkatabalasubramanian, S; Hayashi, A; Johansson, E; Zeng, Z-j; Mohlin, S; Påhlman, S; Hansford, L; Kaplan, D R; Funa, K

2014-10-30

Nuclear orphan receptor TLX (Drosophila tailless homolog) is essential for the maintenance of neural stem/progenitor cell self-renewal, but its role in neuroblastoma (NB) is not well understood. Here, we show that TLX is essential for the formation of tumor spheres in three different NB cell lines, when grown in neural stem cell media. We demonstrate that the knock down of TLX in IMR-32 cells diminishes its tumor sphere-forming capacity. In tumor spheres, TLX is coexpressed with the neural progenitor markers Nestin, CD133 and Oct-4. In addition, TLX is coexpressed with the migratory neural progenitor markers CD15 and matrix metalloproteinase-2 (MMP-2) in xenografts of primary NB cells from patients. Subsequently, we show the effect of TLX on the proliferative, invasive and migratory properties of IMR-32 cells. We attribute this to the recruitment of TLX to both MMP-2 and Oct-4 gene promoters, which resulted in the respective gene activation. In support of our findings, we found that TLX expression was high in NB patient tissues when compared with normal peripheral nervous system tissues. Further, the Kaplan-Meier estimator indicated a negative correlation between TLX expression and survival in 88 NB patients. Therefore, our results point at TLX being a crucial player in progression of NB, by promoting self-renewal of NB tumor-initiating cells and altering their migratory and invasive properties.

The Croton megalobotrys Müll Arg. traditional medicine in HIV/AIDS management: Documentation of patient use, in vitro activation of latent HIV-1 provirus, and isolation of active phorbol esters.

Science.gov (United States)

Tietjen, Ian; Ngwenya, Barbara N; Fotso, Ghislain; Williams, David E; Simonambango, Sundana; Ngadjui, Bonaventure T; Andersen, Raymond J; Brockman, Mark A; Brumme, Zabrina L; Andrae-Marobela, Kerstin

2018-01-30

Current HIV therapies do not act on latent cellular HIV reservoirs; hence they are not curative. While experimental latency reversal agents (LRAs) can promote HIV expression in these cells, thereby exposing them to immune recognition, existing LRAs exhibit limited clinical efficacy and high toxicity. We previously described a traditional 3-step medicinal plant regimen used for HIV/AIDS management in Northern Botswana that inhibits HIV replication in vitro. Here we describe use of one component of the regimen that additionally contains novel phorbol esters possessing HIV latency-reversal properties. We sought to document experiences of traditional medicine users, assess the ability of traditional medicine components to reverse HIV latency in vitro, and identify pure compounds that conferred these activities. Experiences of two HIV-positive traditional medicine users (patients) were documented using qualitative interview techniques. Latency reversal activity was assessed using a cell-based model (J-Lat, clone 9.2). Crude plant extracts were fractionated by open column chromatography and reverse-phase HPLC. Compound structures were elucidated using NMR spectroscopy and mass spectrometry. Patients using the 3-step regimen reported improved health over several years despite no reported use of standard HIV therapies. Crude extracts from Croton megalobotrys Müll Arg. ("Mukungulu"), the third component of the 3-step regimen, induced HIV expression in J-lat cells to levels comparable to the known LRA prostratin. Co-incubation with known LRAs and pharmacological inhibitors indicated that the active agent(s) in C. megalobotrys were likely to be protein kinase C (PKC) activator(s). Consistent with these results, two novel phorbol esters (Namushen 1 and 2) were isolated as abundant components of C. megalobotrys and were sufficient to confer HIV latency reversal in vitro. We have identified novel LRAs of the phorbol ester class from a medicinal plant used in HIV/AIDS management

Genetic and Epigenetic Tumor Suppressor Gene Silencing are Distinct Molecular Phenotypes Driven by Growth Promoting Mutations in Non small Cell Lung Cancer

International Nuclear Information System (INIS)

Marsit, C. J.; Kelsey, K. T.; Houseman, E. A.; Kelsey, K. T.; Houseman, E. A.; Nelson, H. H.

2008-01-01

Both genetic and epigenetic alterations characterize human non small cell lung cancer (NSCLC), but the biological processes that create or select these alterations remain incompletely investigated. Our hypothesis posits that a roughly reciprocal relationship between the propensity for promoter hyper methylation and a propensity for genetic deletion leads to distinct molecular phenotypes of lung cancer. To test this hypothesis, we examined promoter hyper methylation of 17 tumor suppressor genes, as a marker of epigenetic alteration propensity, and deletion events at the 3p21 region, as a marker of genetic alteration. To model the complex biology between these somatic alterations, we utilized an item response theory model. We demonstrated that tumors exhibiting LOH at greater than 30% of informative alleles in the 3p21 region have a significantly reduced propensity for hyper methylation. At the same time, tumors with activating KRAS mutations showed a significantly increased propensity for hyper methylation of the loci examined, a result similar to what has been observed in colon cancer. These data suggest that NSCLCs have distinct epigenetic or genetic alteration phenotypes acting upon tumor suppressor genes and that mutation of oncogenic growth promoting genes, such as KRAS, is associated with the epigenetic phenotype.

Effects of a tumor promoter and an anti-promoter on spontaneous and UV-induced 6-thioguanine-resistant mutations and sister-chromatid exchanges in V79 Chinese hamster cells

International Nuclear Information System (INIS)

Fujiwara, Y.; Kano, Y.; Tatsumi, M.; Paul, P.

1980-01-01

The effects of a tumor promoter 12-O-tetradecanoylphorbol-13-acetate (TPA) and/or an anti-promoter antipain (protease inhibitor) on spontaneous and ultraviolet-induced sister-chromatid exchanges (SCEs) and 6-thioguanine-resistant (6TGsup(r)) recessive mutations were examined in V79 Chinese hamster cells in culture. TPA and/or antipain neither significantly altered base-line and UV-induced immediate SCE frequencies, nor decreased the level of delayed SCEs which persisted 6-7 days after irradiation. TPA and/or antipain appeared to enhance the recovery of UV-induced 6TGsup(r) colonies at the plateau expression phase despite non-mutagenicity by themselves and unaltered metabolic cooperation. Thus, the results conceivably imply that the 6TGsup(r)-recessive mutation expression, but not fixation, can be modulated at the cell level by TPA and/or antipain. Our results, together with the recent results of Loveday and Latt, may argue against the notion that TPA enhances the antipain-suppressible SCEs as an index of mitotic recombination in relevance with a tumor-promotion mechanism. (orig.)

Linkage mapping in the oilseed crop Jatropha curcas L. reveals a locus controlling the biosynthesis of phorbol esters which cause seed toxicity

NARCIS (Netherlands)

King, A.J.; Montes, L.R.; Clarke, J.G.; Affleck, J.; Li, Y.; Witsenboer, H.; Vossen, van der E.; Linde, van der P.; Tripathi, Y.; Tavares, E.; Shukla, P.; Rajasekaran, T.; Loo, van E.N.; Graham, I.A.

2013-01-01

Current efforts to grow the tropical oilseed crop Jatropha curcas L. economically are hampered by the lack of cultivars and the presence of toxic phorbol esters (PE) within the seeds of most provenances. These PE restrict the conversion of seed cake into animal feed, although naturally occurring

Adiponectin haploinsufficiency promotes mammary tumor development in MMTV-PyVT mice by modulation of phosphatase and tensin homolog activities.

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Janice B B Lam

Full Text Available Adiponectin is an adipokine possessing beneficial effects on obesity-related medical complications. A negative association of adiponectin levels with breast cancer development has been demonstrated. However, the precise role of adiponectin deficiency in mammary carcinogenesis remains elusive.In the present study, MMTV-polyomavirus middle T antigen (MMTV-PyVT transgenic mice with reduced adiponectin expressions were established and the stromal effects of adiponectin haploinsufficiency on mammary tumor development evaluated. In mice from both FVB/N and C57BL/6J backgrounds, insufficient adiponectin production promoted mammary tumor onset and development. A distinctive basal-like subtype of tumors, with a more aggressive phenotype, was derived from adiponectin haplodeficient MMTV-PyVT mice. Comparing with those from control MMTV-PyVT mice, the isolated mammary tumor cells showed enhanced tumor progression in re-implanted nude mice, accelerated proliferation in primary cultures, and hyperactivated phosphatidylinositol-3-kinase (PI3K/Akt/beta-catenin signaling, which at least partly attributed to the decreased phosphatase and tensin homolog (PTEN activities. Further analysis revealed that PTEN was inactivated by a redox-regulated mechanism. Increased association of PTEN-thioredoxin complexes was detected in tumors derived from mice with reduced adiponectin levels. The activities of thioredoxin (Trx1 and thioredoxin reductase (TrxR1 were significantly elevated, whereas treatment with either curcumin, an irreversible inhibitor of TrxR1, or adiponectin largely attenuated their activities and resulted in the re-activation of PTEN in these tumor cells. Moreover, adiponectin could inhibit TrxR1 promoter-mediated transcription and restore the mRNA expressions of TrxR1.Adiponectin haploinsufficiency facilitated mammary tumorigenesis by down-regulation of PTEN activity and activation of PI3K/Akt signalling pathway through a mechanism involving Trx1/TrxR1

Detoxification of toxic phorbol esters from Malaysian Jatropha curcas Linn. kernel by Trichoderma spp. and endophytic fungi.

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Najjar, Azhar; Abdullah, Norhani; Saad, Wan Zuhainis; Ahmad, Syahida; Oskoueian, Ehsan; Abas, Faridah; Gherbawy, Youssuf

2014-02-05

The presence of phorbol esters (PEs) with toxic properties limits the use of Jatropha curcas kernel in the animal feed industry. Therefore, suitable methods to detoxify PEs have to be developed to render the material safe as a feed ingredient. In the present study, the biological treatment of the extracted PEs-rich fraction with non-pathogenic fungi (Trichoderma harzianum JQ350879.1, T. harzianum JQ517493.1, Paecilomyces sinensis JQ350881.1, Cladosporium cladosporioides JQ517491.1, Fusarium chlamydosporum JQ350882.1, F. chlamydosporum JQ517492.1 and F. chlamydosporum JQ350880.1) was conducted by fermentation in broth cultures. The PEs were detected by liquid chromatography-diode array detector-electrospray ionization mass spectrometry (LC-DAD-ESIMS) and quantitatively monitored by HPLC using phorbol-12-myristate 13-acetate as the standard. At day 30 of incubation, two T. harzianum spp., P. sinensis and C. cladosporioides significantly (p rich fraction for growth. In the cytotoxicity assay, cell viabilities of Chang liver and NIH 3T3 fibroblast cell lines were less than 1% with the untreated PEs-rich fraction, but 84.3%-96.5% with the fungal treated PEs-rich fraction. There was no inhibition on cell viability for normal fungal growth supernatants. To conclude, Trichoderma spp., Paecilomyces sp. and Cladosporium sp. are potential microbes for the detoxification of PEs.

Presence of Insulin-Like Growth Factor Binding Proteins Correlates With Tumor-Promoting Effects of Matrix Metalloproteinase 9 in Breast Cancer

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Jae-Hyun Park

2015-05-01

Full Text Available The stroma of breast cancer can promote the disease’s progression, but whether its composition and functions are shared among different subtypes is poorly explored. We compared stromal components of a luminal [mouse mammary tumor virus (MMTV–Neu] and a triple-negative/basal-like [C3(1–Simian virus 40 large T antigen (Tag] genetically engineered breast cancer mouse model. The types of cytokines and their expression levels were very different in the two models, as was the extent of innate immune cell infiltration; however, both models showed infiltration of innate immune cells that expressed matrix metalloproteinase 9 (MMP9, an extracellular protease linked to the progression of many types of cancer. By intercrossing with Mmp9 null mice, we found that the absence of MMP9 delayed tumor onset in the C3(1-Tag model but had no effect on tumor onset in the MMTV-Neu model. We discovered that protein levels of insulin-like growth factor binding protein-1 (IGFBP-1, an MMP9 substrate, were increased in C3(1-Tag;Mmp9−/− compared to C3(1-Tag;Mmp9+/+ tumors. In contrast, IGFBP-1 protein expression was low in MMTV-Neu tumors regardless of Mmp9 status. IGFBP-1 binds and antagonizes IGFs, preventing them from activating their receptors to promote cell proliferation and survival. Tumors from C3(1-Tag;Mmp9−/− mice had reduced IGF-1 receptor phosphorylation, consistent with slower tumor onset. Finally, gene expression analysis of human breast tumors showed that high expression of IGFBP mRNA was strongly correlated with good prognosis but not when MMP9 mRNA was also highly expressed. In conclusion, MMP9 has different effects on breast cancer progression depending on whether IGFBPs are expressed.

Downregulation of BTLA on NKT Cells Promotes Tumor Immune Control in a Mouse Model of Mammary Carcinoma.

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Sekar, Divya; Govene, Luisa; Del Río, María-Luisa; Sirait-Fischer, Evelyn; Fink, Annika F; Brüne, Bernhard; Rodriguez-Barbosa, José I; Weigert, Andreas

2018-03-07

Natural Killer T cells (NKT cells) are emerging as critical regulators of pro- and anti-tumor immunity, both at baseline and in therapeutic settings. While type I NKT cells can promote anti-tumor immunity, their activity in the tumor microenvironment may be limited by negative regulators such as inhibitory immune checkpoints. We observed dominant expression of B- and T-lymphocyte attenuator (BTLA) on type I NKT cells in polyoma middle T oncogene-driven (PyMT) murine autochthonous mammary tumors. Other immune checkpoint receptors, such as programmed cell death 1 (PD-1) were equally distributed among T cell populations. Interference with BTLA using neutralizing antibodies limited tumor growth and pulmonary metastasis in the PyMT model in a therapeutic setting, correlating with an increase in type I NKT cells and expression of cytotoxic marker genes. While therapeutic application of an anti-PD-1 antibody increased the number of CD8+ cytotoxic T cells and elevated IL-12 expression, tumor control was not established. Expression of ZBTB16, the lineage-determining transcription factor of type I NKT cells, was correlated with a favorable patient prognosis in the METABRIC dataset, and BTLA levels were instrumental to further distinguish prognosis in patents with high ZBTB16 expression. Taken together, these data support a role of BTLA on type I NKT cells in limiting anti-tumor immunity.

Downregulation of BTLA on NKT Cells Promotes Tumor Immune Control in a Mouse Model of Mammary Carcinoma

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Divya Sekar

2018-03-01

Full Text Available Natural Killer T cells (NKT cells are emerging as critical regulators of pro- and anti-tumor immunity, both at baseline and in therapeutic settings. While type I NKT cells can promote anti-tumor immunity, their activity in the tumor microenvironment may be limited by negative regulators such as inhibitory immune checkpoints. We observed dominant expression of B- and T-lymphocyte attenuator (BTLA on type I NKT cells in polyoma middle T oncogene-driven (PyMT murine autochthonous mammary tumors. Other immune checkpoint receptors, such as programmed cell death 1 (PD-1 were equally distributed among T cell populations. Interference with BTLA using neutralizing antibodies limited tumor growth and pulmonary metastasis in the PyMT model in a therapeutic setting, correlating with an increase in type I NKT cells and expression of cytotoxic marker genes. While therapeutic application of an anti-PD-1 antibody increased the number of CD8+ cytotoxic T cells and elevated IL-12 expression, tumor control was not established. Expression of ZBTB16, the lineage-determining transcription factor of type I NKT cells, was correlated with a favorable patient prognosis in the METABRIC dataset, and BTLA levels were instrumental to further distinguish prognosis in patents with high ZBTB16 expression. Taken together, these data support a role of BTLA on type I NKT cells in limiting anti-tumor immunity.

Steroidogenesis and early response gene expression in MA-10 Leydig tumor cells following heterologous receptor down-regulation and cellular desensitization

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Tsuey-Ming Chen

2016-03-01

Full Text Available The Leydig tumor cell line, MA-10, expresses the luteinizing hormone receptor, a G protein-coupled receptor that, when activated with luteinizing hormone or chorionic gonadotropin (CG, stimulates cAMP production and subsequent steroidogenesis, notably progesterone. These cells also respond to epidermal growth factor (EGF and phorbol esters with increased steroid biosynthesis. In order to probe the intracellular pathways along with heterologous receptor down-regulation and cellular desensitization, cells were preincubated with EGF or phorbol esters and then challenged with CG, EGF, dibutryl-cyclic AMP, and a phorbol ester. Relative receptor numbers, steroid biosynthesis, and expression of the early response genes, JUNB and c-FOS, were measured. It was found that in all cases but one receptor down-regulation and decreased progesterone production were closely coupled under the conditions used; the exception involved preincubation of the cells with EGF followed by addition of CG where the CG-mediated stimulation of steroidogenesis was considerably lower than the level of receptor down-regulation. In a number of instances JUNB and c-FOS expression paralleled the decreases in receptor number and progesterone production, while in some cases these early response genes were affected little if at all by the changes in receptor number. This finding may indicate that even low levels of activated signaling kinases, e.g. protein kinase A, protein kinase C, or receptor tyrosine kinase, may suffice to yield good expression of JUNB and c-FOS, or it may suggest alternative pathways for regulating expression of these two early response genes.

The Atypical Kinase RIOK1 Promotes Tumor Growth and Invasive Behavior

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Florian Weinberg

2017-06-01

Full Text Available Despite being overexpressed in different tumor entities, RIO kinases are hardly characterized in mammalian cells. We investigated the role of these atypical kinases in different cancer cells. Using isogenic colon-, breast- and lung cancer cell lines, we demonstrate that knockdown of RIOK1, but not of RIOK2 or RIOK3, strongly impairs proliferation and invasiveness in conventional and 3D culture systems. Interestingly, these effects were mainly observed in RAS mutant cancer cells. In contrast, growth of RAS wildtype Caco-2 and Bcr-Abl-driven K562 cells is not affected by RIOK1 knockdown, suggesting a specific requirement for RIOK1 in the context of oncogenic RAS signaling. Furthermore, we show that RIOK1 activates NF-κB signaling and promotes cell cycle progression. Using proteomics, we identified the pro-invasive proteins Metadherin and Stathmin1 to be regulated by RIOK1. Additionally, we demonstrate that RIOK1 promotes lung colonization in vivo and that RIOK1 is overexpressed in different subtypes of human lung- and breast cancer. Altogether, our data suggest RIOK1 as a potential therapeutic target, especially in RAS-driven cancers.

A novel immunomodulatory hemocyanin from the limpet Fissurella latimarginata promotes potent anti-tumor activity in melanoma.

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Sergio Arancibia

Full Text Available Hemocyanins, the huge oxygen-transporting glycoproteins of some mollusks, are used as immunomodulatory proteins with proven anti-cancer properties. The biodiversity of hemocyanins has promoted interest in identifying new anti-cancer candidates with improved immunological properties. Hemocyanins promote Th1 responses without known side effects, which make them ideal for long-term sustained treatment of cancer. In this study, we evaluated a novel hemocyanin from the limpet/gastropod Fissurella latimarginata (FLH. This protein has the typical hollow, cylindrical structure of other known hemocyanins, such as the keyhole limpet hemocyanin (KLH and the Concholepas hemocyanin (CCH. FLH, like the KLH isoforms, is composed of a single type of polypeptide with exposed N- and O-linked oligosaccharides. However, its immunogenicity was significantly greater than that of KLH and CCH, as FLH induced a stronger humoral immune response and had more potent anti-tumor activity, delaying tumor growth and increasing the survival of mice challenged with B16F10 melanoma cells, in prophylactic and therapeutic settings. Additionally, FLH-treated mice demonstrated increased IFN-γ production and higher numbers of tumor-infiltrating CD4(+ lymphocytes. Furthermore, in vitro assays demonstrated that FLH, but not CCH or KLH, stimulated the rapid production of pro-inflammatory cytokines (IL-6, IL-12, IL-23 and TNF-α by dendritic cells, triggering a pro-inflammatory milieu that may explain its enhanced immunological activity. Moreover, this effect was abolished when deglycosylated FLH was used, suggesting that carbohydrates play a crucial role in the innate immune recognition of this protein. Altogether, our data demonstrate that FLH possesses increased anti-tumor activity in part because it activates a more potent innate immune response in comparison to other known hemocyanins. In conclusion, FLH is a potential new marine adjuvant for immunization and possible cancer

A novel immunomodulatory hemocyanin from the limpet Fissurella latimarginata promotes potent anti-tumor activity in melanoma.

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Arancibia, Sergio; Espinoza, Cecilia; Salazar, Fabián; Del Campo, Miguel; Tampe, Ricardo; Zhong, Ta-Ying; De Ioannes, Pablo; Moltedo, Bruno; Ferreira, Jorge; Lavelle, Ed C; Manubens, Augusto; De Ioannes, Alfredo E; Becker, María Inés

2014-01-01

Hemocyanins, the huge oxygen-transporting glycoproteins of some mollusks, are used as immunomodulatory proteins with proven anti-cancer properties. The biodiversity of hemocyanins has promoted interest in identifying new anti-cancer candidates with improved immunological properties. Hemocyanins promote Th1 responses without known side effects, which make them ideal for long-term sustained treatment of cancer. In this study, we evaluated a novel hemocyanin from the limpet/gastropod Fissurella latimarginata (FLH). This protein has the typical hollow, cylindrical structure of other known hemocyanins, such as the keyhole limpet hemocyanin (KLH) and the Concholepas hemocyanin (CCH). FLH, like the KLH isoforms, is composed of a single type of polypeptide with exposed N- and O-linked oligosaccharides. However, its immunogenicity was significantly greater than that of KLH and CCH, as FLH induced a stronger humoral immune response and had more potent anti-tumor activity, delaying tumor growth and increasing the survival of mice challenged with B16F10 melanoma cells, in prophylactic and therapeutic settings. Additionally, FLH-treated mice demonstrated increased IFN-γ production and higher numbers of tumor-infiltrating CD4(+) lymphocytes. Furthermore, in vitro assays demonstrated that FLH, but not CCH or KLH, stimulated the rapid production of pro-inflammatory cytokines (IL-6, IL-12, IL-23 and TNF-α) by dendritic cells, triggering a pro-inflammatory milieu that may explain its enhanced immunological activity. Moreover, this effect was abolished when deglycosylated FLH was used, suggesting that carbohydrates play a crucial role in the innate immune recognition of this protein. Altogether, our data demonstrate that FLH possesses increased anti-tumor activity in part because it activates a more potent innate immune response in comparison to other known hemocyanins. In conclusion, FLH is a potential new marine adjuvant for immunization and possible cancer immunotherapy.

Porritoxins, metabolites of Alternaria porri, as anti-tumor-promoting active compounds.

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Horiuchi, Masayuki; Tokuda, Harukuni; Ohnishi, Keiichiro; Yamashita, Masakazu; Nishino, Hoyoku; Maoka, Takashi

2006-02-01

To search for possible cancer chemopreventive agents from natural sources, we performed primary screening of metabolites of Alternaria porri by examining their possible inhibitory effects on Epstein-Barr virus early antigen (EBV-EA) activation induced by 12-O-tetradecanoylphorbol-13-acetate (TPA) in Raji cells. The ethyl acetate extract of A. porri showed the inhibitory effect on EBV-EA activation. Three porritoxins (1-3) were obtained as inhibitory active compounds for EBV-EA from ethyl acetate extract. 6-(3',3'-Dimethylallyloxy)-4-methoxy-5-methylphthalide (2) showed the strongest activity among them. Inhibitory effect of porritoxin (1) and (2) was superior to that of beta-carotene, a well-known anti-tumor promoter. Furthermore, the structure-activity correlation of porritoxins and their related compounds were discussed.

Tumor cell-derived microparticles polarize M2 tumor-associated macrophages for tumor progression.

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Ma, Ruihua; Ji, Tiantian; Chen, Degao; Dong, Wenqian; Zhang, Huafeng; Yin, Xiaonan; Ma, Jingwei; Liang, Xiaoyu; Zhang, Yi; Shen, Guanxin; Qin, Xiaofeng; Huang, Bo

2016-04-01

Despite identification of macrophages in tumors (tumor-associated macrophages, TAM) as potential targets for cancer therapy, the origin and function of TAM in the context of malignancy remain poorly characterized. Here, we show that microparticles (MPs), as a by-product, released by tumor cells act as a general mechanism to mediate M2 polarization of TAM. Taking up tumor MPs by macrophages is a very efficient process, which in turn results in the polarization of macrophages into M2 type, not only leading to promoting tumor growth and metastasis but also facilitating cancer stem cell development. Moreover, we demonstrate that the underlying mechanism involves the activation of the cGAS/STING/TBK1/STAT6 pathway by tumor MPs. Finally, in addition to murine tumor MPs, we show that human counterparts also possess consistent effect on human M2 polarization. These findings provide new insights into a critical role of tumor MPs in remodeling of tumor microenvironment and better understanding of the communications between tumors and macrophages.

[Initiation, promotion, initiation experiments with radon and cigarette smoke: Lung tumors in rats]. Progress report

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Moolgavkar, S.H.

1994-01-01

During the past several years, the authors have made considerable progress in modeling carcinogenesis in general, and in modeling radiation carcinogenesis, in particular. They present an overview of their progress in developing stochastic carcinogenesis models and applying them to experimental and epidemiologic data sets. Traditionally, cancer models have been used for the analysis of incidence (or prevalence) data in epidemiology and time to tumor data in experimental studies. The relevant quantities for the analysis of these data are the hazard function and the probability of tumor. The derivation of these quantities is briefly described here. More recently, the authors began to use these models for the analysis of data on intermediate lesions on the pathway to cancer. Such data are available in experimental carcinogenesis studies, in particular in initiation and promotion studies on the mouse skin and the rat liver. If however, quantitative information on intermediate lesions on the pathway to lung cancer were to be come available at some future date, the methods that they have developed for the analysis of initiation-promotion experiments could easily be applied to the analysis of these lesions. The mathematical derivations here are couched in terms of a particular two-mutation model of carcinogenesis. Extension to models postulating more than two mutations is not always straightforward

Biodegradation of Jatropha curcas phorbol esters in soil.

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Devappa, Rakshit K; Makkar, Harinder Ps; Becker, Klaus

2010-09-01

Jatropha curcas seed cake is generated as a by-product during biodiesel production. Seed cake containing toxic phorbol esters (PEs) is currently used as a fertiliser and thus it is of eco-toxicological concern. In the present study the fate of PEs in soil was studied. Two approaches for the incorporation of PEs in soil were used. In the first, silica was bound to PEs, and in the second, seedcake was used. At day 0, the concentration of PEs in soil was 2.6 and 0.37 mg g(-1) for approach 1 and 2 respectively. PEs from silica bound PEs were completely degraded after 19, 12, 12 days (at 130 g kg(-1) moisture) and after 17, 9, 9 days (at 230 g kg(-1) moisture) at room temperature, 32 degrees C and 42 degrees C respectively. Similarly at these temperatures PEs from seed cake were degraded after 21, 17 and 17 days (at 130 g kg(-1) moisture) and after 23, 17, and 15 days (at 230 g kg(-1) moisture). Increase in temperature and moisture increased rate of PEs degradation. Using the snail (Physa fontinalis) bioassay, mortality by PE-amended soil extracts decreased with the decrease in PE concentration in soil. Jatropha PEs are biodegradable. The degraded products are innocuous. Copyright 2010 Society of Chemical Industry.

Transgenic overexpression of NanogP8 in the mouse prostate is insufficient to initiate tumorigenesis but weakly promotes tumor development in the Hi-Myc mouse model.

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Liu, Bigang; Gong, Shuai; Li, Qiuhui; Chen, Xin; Moore, John; Suraneni, Mahipal V; Badeaux, Mark D; Jeter, Collene R; Shen, Jianjun; Mehmood, Rashid; Fan, Qingxia; Tang, Dean G

2017-08-08

This project was undertaken to address a critical cancer biology question: Is overexpression of the pluripotency molecule Nanog sufficient to initiate tumor development in a somatic tissue? Nanog1 is critical for the self-renewal and pluripotency of ES cells, and its retrotransposed homolog, NanogP8 is preferentially expressed in somatic cancer cells. Our work has shown that shRNA-mediated knockdown of NanogP8 in prostate, breast, and colon cancer cells inhibits tumor regeneration whereas inducible overexpression of NanogP8 promotes cancer stem cell phenotypes and properties. To address the key unanswered question whether tissue-specific overexpression of NanogP8 is sufficient to promote tumor development in vivo , we generated a NanogP8 transgenic mouse model, in which the ARR 2 PB promoter was used to drive NanogP8 cDNA. Surprisingly, the ARR 2 PB-NanogP8 transgenic mice were viable, developed normally, and did not form spontaneous tumors in >2 years. Also, both wild type and ARR 2 PB-NanogP8 transgenic mice responded similarly to castration and regeneration and castrated ARR 2 PB-NanogP8 transgenic mice also did not develop tumors. By crossing the ARR 2 PB-NanogP8 transgenic mice with ARR 2 PB-Myc (i.e., Hi-Myc) mice, we found that the double transgenic (i.e., ARR 2 PB-NanogP8; Hi-Myc) mice showed similar tumor incidence and histology to the Hi-Myc mice. Interestingly, however, we observed white dots in the ventral lobes of the double transgenic prostates, which were characterized as overgrown ductules/buds featured by crowded atypical Nanog-expressing luminal cells. Taken together, our present work demonstrates that transgenic overexpression of NanogP8 in the mouse prostate is insufficient to initiate tumorigenesis but weakly promotes tumor development in the Hi-Myc mouse model.

Promoting Effects of Milk on the Development of 7,12-dimethylbenz(a)anthracene (DMBA)-induced Mammary Tumors in Rats

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Ma, De-Fu; Katoh, Ryohei; Zhou, Hong; Wang, Pei-Yu

2007-01-01

To assess the effect of milk on the development of 7,12-dimethylbenz(a)anthracene (DMBA)-induced mammary tumors, 48 female Sprague-Dawley rats treated with DMBA were divided into 3 groups and given 1 of 3 test solutions for 20 weeks as their drinking liquid: milk, estrone sulfate solution or tap water. The milk group showed a significantly great incidence (75%) in tumor development compared with the water group (38%) and was comparable to the estrone sulfate group (69%). Mean tumor number per rat in the milk group was significantly higher than that in the water group (p=0.009). We classified the mammary tumors into three histological types: intraductal papilloma, fibroadenoma, and adenocarcinoma. Although the percent of intraductal papilloma and fibroadenoma was almost same among the three groups, malignant tumor was found only in the milk and estrone sulfate groups. In conclusion, our results indicate that milk as well as estrone sulfate promotes the development of DMBA-induced mammary tumors in rat and could be associated with the occurrence of adenocarcinoma

Inhibitory effects of curcumin and capsaicin on phorbol ester-induced activation of eukaryotic transcription factors, NF-kappaB and AP-1.

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Surh, Y J; Han, S S; Keum, Y S; Seo, H J; Lee, S S

2000-01-01

Recently, considerable attention has been focused on identifying dietary and medicinal phytochemicals that can inhibit, retard or reverse the multi-stage carcinogenesis. Spices and herbs contain phenolic substances with potent antioxidative and chemopreventive properties. Curcumin, a yellow colouring agent from turmeric and capsaicin, a pungent principle of red pepper exhibit profound anticarcinogenic and antimutagenic activities. Two well-defined eukaryotic transcription factors, nuclear factor-kappa B (NF-kappaB) and activator protein 1 (AP-1) have been implicated in pathogenesis of many human diseases including cancer. These transcription factors are known to be activated by a wide array of external stimuli, such as tumor promoter 12-O-tetradecanoylphorbol-13-acetate (TPA), tumor necrosis factor, reactive oxygen species, bacterial lipopolysaccharide, and ultraviolet. In the present study, we found that topical application of TPA onto dorsal skin of female ICR mice resulted in marked activation of epidermal NF-kappaB and AP-1. Curcumin and capsaicin, when topically applied prior to TPA, significantly attenuated TPA-induced activation of each transcription factor in mouse skin. Likewise, both compounds inhibited NF-kappaB and AP-1 activation in cultured human promyelocytic leukemia (HL-60) cells stimulated with TPA. Based on these findings, it is likely that curcumin and capsaicin exert anti-tumor promotional effects through suppression of the tumor promoter-induced activation of transcription factors, NF-kappaB and AP-1.

Stromal-dependent tumor promotion by MIF family members.

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Mitchell, Robert A; Yaddanapudi, Kavitha

2014-12-01

Solid tumors are composed of a heterogeneous population of cells that interact with each other and with soluble and insoluble factors that, when combined, strongly influence the relative proliferation, differentiation, motility, matrix remodeling, metabolism and microvessel density of malignant lesions. One family of soluble factors that is becoming increasingly associated with pro-tumoral phenotypes within tumor microenvironments is that of the migration inhibitory factor family which includes its namesake, MIF, and its only known family member, D-dopachrome tautomerase (D-DT). This review seeks to highlight our current understanding of the relative contributions of a variety of immune and non-immune tumor stromal cell populations and, within those contexts, will summarize the literature associated with MIF and/or D-DT. Copyright © 2014 Elsevier Inc. All rights reserved.

Clinical Utility of promoter methylation of the tumor suppressor genes DKK3, and RASSF1A in breast cancer patients

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Marwa H. Saied

2018-04-01

Full Text Available Background: DNA methylation is the commonest known epigenetic change that results in silencing of tumor suppressor genes. Promoter methylation of tumor suppressor genes has the potential for early detection of breast cancer. Aim: Aim is to examine the potential usefulness of blood based methylation specific polymerase chain reaction (MSP of methylated DKK3 and RASSF1A genes in early detection of breast cancer. Method: Methylation status of DKK3 and RASSF1 was investigated in forty breast cancer patients, twenty fibroadenoma patients and twenty healthy ladies as control group using MSP. Results: Methylation of DKK3 promoter was found in 22.5% of breast cancer patients, while DKK3 methylation was absent in both fibroadenoma patients and control group. Similarly, methylation of RASSF1 promoter was found in 17.5% of breast cancer patients and in none of fibroadenoma and control group. Conclusion: Promoter methylation of DKK3 and RASSF1 was found in breast cancer patients while absent in control group suggesting that tumorspecific methylation of the two genes (DKK3 and RASSF1A might be a valuable biomarker for the early detection of breast cancer. Keywords: DNA methylation, Breast cancer, DKK3, RASSF1

Exosomes Derived from Human Bone Marrow Mesenchymal Stem Cells Promote Tumor Growth Through Hedgehog Signaling Pathway

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Jin Qi

2017-08-01

Full Text Available Background/Aims: Mesenchymal stem/stromal cells (MSCs are known to home to sites of tumor microenvironments where they participate in the formation of the tumor microenvironment and to interplay with tumor cells. However, the potential functional effects of MSCs on tumor cell growth are controversial. Here, we, from the view of bone marrow MSC-derived exosomes, study the molecular mechanism of MSCs on the growth of human osteosarcoma and human gastric cancer cells. Methods: MSCs derived from human bone marrow (hBMSCs were isolated and cultured in complete DMEM/F12 supplemented with 10% exosome-depleted fetal bovine serum and 1% penicillin-streptomycin, cell culture supernatants containing exosomes were harvested and exosome purification was performed by ultracentrifugation. Osteosarcoma (MG63 and gastric cancer (SGC7901 cells, respectively, were treated with hBMSC-derived exosomes in the presence or absence of a small molecule inhibitor of Hedgehog pathway. Cell viability was measured by transwell invasion assay, scratch migration assay and CCK-8 test. The expression of the signaling molecules Smoothened, Patched-1, Gli1 and the ligand Shh were tested by western blot and RT-PCR. Results: In this study, we found that hBMSC-derived exosomes promoted MG63 and SGC7901 cell growth through the activation of Hedgehog signaling pathway. Inhibition of Hedgehog signaling pathway significantly suppressed the process of hBMSC-derived exosomes on tumor growth. Conclusion: Our findings demonstrated the new roles of hedgehog signaling pathway in the hBMSCs-derived exosomes induced tumor progression.

PI3-kinase γ promotes Rap1a-mediated activation of myeloid cell integrin α4β1, leading to tumor inflammation and growth.

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Michael C Schmid

Full Text Available Tumor inflammation, the recruitment of myeloid lineage cells into the tumor microenvironment, promotes angiogenesis, immunosuppression and metastasis. CD11b+Gr1lo monocytic lineage cells and CD11b+Gr1hi granulocytic lineage cells are recruited from the circulation by tumor-derived chemoattractants, which stimulate PI3-kinase γ (PI3Kγ-mediated integrin α4 activation and extravasation. We show here that PI3Kγ activates PLCγ, leading to RasGrp/CalDAG-GEF-I&II mediated, Rap1a-dependent activation of integrin α4β1, extravasation of monocytes and granulocytes, and inflammation-associated tumor progression. Genetic depletion of PLCγ, CalDAG-GEFI or II, Rap1a, or the Rap1 effector RIAM was sufficient to prevent integrin α4 activation by chemoattractants or activated PI3Kγ (p110γCAAX, while activated Rap (RapV12 promoted constitutive integrin activation and cell adhesion that could only be blocked by inhibition of RIAM or integrin α4β1. Similar to blockade of PI3Kγ or integrin α4β1, blockade of Rap1a suppressed both the recruitment of monocytes and granulocytes to tumors and tumor progression. These results demonstrate critical roles for a PI3Kγ-Rap1a-dependent pathway in integrin activation during tumor inflammation and suggest novel avenues for cancer therapy.

Tumor-secreted miR-214 induces regulatory T cells: a major link between immune evasion and tumor growth

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Yin, Yuan; Cai, Xing; Chen, Xi; Liang, Hongwei; Zhang, Yujing; Li, Jing; Wang, Zuoyun; Chen, Xiulan; Zhang, Wen; Yokoyama, Seiji; Wang, Cheng; Li, Liang; Li, Limin; Hou, Dongxia; Dong, Lei; Xu, Tao; Hiroi, Takachika; Yang, Fuquan; Ji, Hongbin; Zhang, Junfeng; Zen, Ke; Zhang, Chen-Yu

2014-01-01

An increased population of CD4+CD25highFoxp3+ regulatory T cells (Tregs) in the tumor-associated microenvironment plays an important role in cancer immune evasion. However, the underlying mechanism remains unclear. Here we observed an increased secretion of miR-214 in various types of human cancers and mouse tumor models. Tumor-secreted miR-214 was sufficiently delivered into recipient T cells by microvesicles (MVs). In targeted mouse peripheral CD4+ T cells, tumor-derived miR-214 efficiently downregulated phosphatase and tensin homolog (PTEN) and promoted Treg expansion. The miR-214-induced Tregs secreted higher levels of IL-10 and promoted tumor growth in nude mice. Furthermore, in vivo studies indicated that Treg expansion mediated by cancer cell-secreted miR-214 resulted in enhanced immune suppression and tumor implantation/growth in mice. The MV delivery of anti-miR-214 antisense oligonucleotides (ASOs) into mice implanted with tumors blocked Treg expansion and tumor growth. Our study reveals a novel mechanism through which cancer cell actively manipulates immune response via promoting Treg expansion. PMID:25223704

Inhibition of gap-junctional intercellular communication and activation of mitogen-activated protein kinases by cyanobacterial extracts--indications of novel tumor-promoting cyanotoxins?

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Bláha, Ludĕk; Babica, Pavel; Hilscherová, Klára; Upham, Brad L

2010-01-01

Toxicity and liver tumor promotion of cyanotoxins microcystins have been extensively studied. However, recent studies document that other metabolites present in the complex cyanobacterial water blooms may also have adverse health effects. In this study we used rat liver epithelial stem-like cells (WB-F344) to examine the effects of cyanobacterial extracts on two established markers of tumor promotion, inhibition of gap-junctional intercellular communication (GJIC) and activation of mitogen-activated protein kinases (MAPKs) - ERK1/2. Extracts of cyanobacteria (laboratory cultures of Microcystis aeruginosa and Aphanizomenon flos-aquae and water blooms dominated by these species) inhibited GJIC and activated MAPKs in a dose-dependent manner (effective concentrations ranging 0.5-5mgd.w./mL). Effects were independent of the microcystin content and the strongest responses were elicited by the extracts of Aphanizomenon sp. Neither pure microcystin-LR nor cylindrospermopsin inhibited GJIC or activated MAPKs. Modulations of GJIC and MAPKs appeared to be specific to cyanobacterial extracts since extracts from green alga Chlamydomonas reinhardtii, heterotrophic bacterium Klebsiella terrigena, and isolated bacterial lipopolysaccharides had no comparable effects. Our study provides the first evidence on the existence of unknown cyanobacterial toxic metabolites that affect in vitro biomarkers of tumor promotion, i.e. inhibition of GJIC and activation of MAPKs.

Differential alterations of phospholipid metabolism in cultured cells of neural origin by phorbol esters, fatty acids, diacylglycerols and related compounds

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Cook, H.W.; Spence, M.W.

1986-01-01

The uptake and metabolism of [ 3 H]methylcholine, [1,2- 14 C]-ethanolamine, [1- 14 C]fatty acids and [ 32 P] were studied in glioma (C6), neuroblastoma (N1E-115) and neuroblastoma-glioma hybrid (NG108-15) cells in culture in the presence of tetradecanoylphorbolacetate (TPA) and related analogues, fatty acids and diacylglycerol (DAG) to assess mechanisms of stimulation of phospholipid synthesis. Choline incorporation into phosphatidylcholine (PC) was stimulated 1.5-3 fold by phorbol esters and 3-10 fold by 18:1(n-9) in C6 cultures; these agents were without effect on N1E-115 and had intermediate effects on NG108-15 cells. Stimulation of [ 32 P] incorporation was predominantly into PC, ethanolamine incorporation into phosphatidylethanolamine (PE) was less stimulated ( 3 H]choline and its incorporation via intracellular phosphocholine into PC whereas exogenous 18:1(n-9) stimulated only utilization of intracellular P-choline in C6 cells. Choline incorporation into PC and relative stimulation by TPA or 18:1 was influenced by medium glucose and choline. Thus, metabolism of phospholipids and their precursors in neural cells can be markedly influenced by phorbol esters and fatty acids but this stimulation is dependent on cell type, growth medium, phospholipid class and nature of the stimulator

Analysis of the tumor-promoting potency of 2,4,4'-trichlorobiphenyl and 2,2',4,5,5'-pentachlorobiphenyl in rat liver

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Kunz, S.; Schmitz, H.J.; Schrenk, D. [Kaiserslautern Univ. (Germany). Dept. of Food Chemistry and Environmental Toxicology; Buchmann, A.; Schwarz, M. [Tuebingen Univ. (Germany). Inst. of Toxicology; Schilling, B.; Paepke, O. [ERGO Research, Hamburg (Germany); Robertson, L.W.; Lehmler, H.J. [Iowa Univ, Iowa City, IA (United States). Dept. of Occupational and Environmental Health

2004-09-15

Polychlorinated biphenyls (PCBs) are potent persistent environmental pollutants exhibiting neurotoxic, teratogenic and tumor-promoting effects in experimental animal models. PCB congeners can be divided into 'dioxin-like' and 'non-dioxin-like' congeners on the basis of their ability to act as aryl hydrocarbon receptor (AhR) agonists. Like the most toxic dioxin congener 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) 'dioxin-like' PCBs bind to the AhR and show characteristic effects on the expression of AhR-regulated genes including the induction of cytochrome P450 (CYP) 1A1. On the other hand, 'non-dioxin-like' PCB congeners have a lower or no binding affinity to the AhR, but exhibit a 'phenobarbital-type' induction of CYP 2B1/2 activity. The tumor-promoting potency of several PCBs has been demonstrated in two-stage initiation-promotion experiments in rat liver. Preneoplastic cell clones, targets for tumor promotion, can be identified as phenotypically altered foci showing characteristic enzyme patterns including the decreased activity of adenosine triphosphatase (ATPase) or the increased expression of the placental form of gluthatione S-transferase (GSTP). In the present study, the effect of the 'non-dioxin-like' 2,4,4'-trichlorobiphenyl (PCB 28) and 2,2',4,5,5'-pentachlorobiphenyl (PCB 101) on the promotion of enzyme-altered hepatic foci was investigated in female Wistar rats after initiation with diethylnitrosamine (DEN).

Effect of hydroxyurea on the promoter occupancy profiles of tumor suppressor p53 and p73

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Lu Xin

2009-06-01

Full Text Available Abstract Background The p53 tumor suppressor and its related protein, p73, share a homologous DNA binding domain, and mouse genetics studies have suggested that they have overlapping as well as distinct biological functions. Both p53 and p73 are activated by genotoxic stress to regulate an array of cellular responses. Previous studies have suggested that p53 and p73 independently activate the cellular apoptotic program in response to cytotoxic drugs. The goal of this study was to compare the promoter-binding activity of p53 and p73 at steady state and after genotoxic stress induced by hydroxyurea. Results We employed chromatin immunoprecipitation, the NimbleGen promoter arrays and a model-based algorithm for promoter arrays to identify promoter sequences enriched in anti-p53 or anti-p73 immunoprecipitates, either before or after treatment with hydroxyurea, which increased the expression of both p53 and p73 in the human colon cancer cell line HCT116-3(6. We calculated a model-based algorithm for promoter array score for each promoter and found a significant correlation between the promoter occupancy profiles of p53 and p73. We also found that after hydroxyurea treatment, the p53-bound promoters were still bound by p73, but p73 became associated with additional promoters that that did not bind p53. In particular, we showed that hydroxyurea induces the binding of p73 but not p53 to the promoter of MLH3, which encodes a mismatch repair protein, and causes an up-regulation of the MLH3 mRNA. Conclusion These results suggest that hydroxyurea exerts differential effects on the promoter-binding functions of p53 and p73 and illustrate the power of model-based algorithm for promoter array in the analyses of promoter occupancy profiles of highly homologous transcription factors.

B Subunit of Human Chorionic Gonadotropin Promotes Tumor Invasion and Predicts Poor Prognosis of Early-Stage Colorectal Cancer

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Jiali Li

2018-01-01

Full Text Available Background/Aims: It is well established that many non-trophoblastic tumors secrete HCG (human chorionic gonadotropin and that such secretion is correlated with the poor prognosis of tumor patients. This study aims to analyze the correlation between β-HCG expression and outcome of colorectal cancer (CRC and understand its role in CRC pathology Methods: We detected the mRNA and protein expression of β-HCG in human CRC tissues with RT-qPCR and immunohistochemistry, and we compared the clinical-pathological characteristics, prognosis and progression between the β-HCG positive and negative groups. We also generated CRC cell lines with β-HCG over-expression as well as β-HCG stable knockout, and evaluated cell function and mechanism in vitro and in vivo. Results: Fifty out of 136 CRC patients (37% expressed β-HCG at the invasive front. Clinical-pathological data showed that β-HCG was positively correlated with Dukes staging (P=0.031 and lymph node metastasis (P=0.012. Survival analysis suggested that the patients with high expression of β-HCG had poorer prognosis than those with low β-HCG expression (P=0.0289. β-HCG expression level was also positively correlated with tumor invasion in early-stage CRC patient tissues (P=0.0227. Additionally β-HCG promoted the migration and invasion of CRC in vitro and in vivo but had no effect on the proliferation of tumor cells. Conclusion: Our study demonstrated that β-HCG was ectopically expressed in the CRC patients and its high expression correlated with poor prognosis of early-stage CRC. Additionally it worked as an oncogene that promotes the migration and invasion of CRC by epithelial-mesenchymal transition (EMT.

Deregulation of the actin cytoskeleton and macropinocytosis in response to phorbol ester by the mutant protein kinase C gamma that causes spinocerebellar ataxia type 14

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Kazuhiro eYamamoto

2014-04-01

Full Text Available Several missense mutations in the protein kinase Cγ (γPKC gene have been found to cause spinocerebellar ataxia type 14 (SCA14, an autosomal dominant neurodegenerative disease. γPKC is a neuron-specific member of the classical PKCs and is activated and translocated to subcellular regions as a result of various stimuli, including diacylglycerol synthesis, increased intracellular Ca2+ and phorbol esters. We investigated whether SCA14 mutations affect the γPKC-related functions by stimulating HeLa cells with TPA (12-O-tetradecanoylpholbol 13-acetate, a type of phorbol ester. Wild-type (WT γPKC-GFP was translocated to the plasma membrane within 10 min of TPA stimulation, followed by its perinuclear translocation and cell shrinkage, in a PKC kinase activity- and microtubule-dependent manner. On the other hand, although SCA14 mutant γPKC-GFP exhibited a similar translocation to the plasma membrane, the subsequent perinuclear translocation and cell shrinkage were significantly impaired in response to TPA. Translocated WT γPKC colocalized with F-actin and formed large vesicular structures in the perinuclear region. The uptake of FITC-dextran, a marker of macropinocytosis, was promoted by TPA stimulation in cells expressing WT γPKC, and FITC-dextran was surrounded by γPKC-positive vesicles. Moreover, TPA induced the phosphorylation of MARCKS, which is a membrane-substrate of PKC, resulting in the translocation of phosphorylated MARCKS to the perinuclear region, suggesting that TPA induces macropinocytosis via γPKC activation. However, TPA failed to activate macropinocytosis and trigger the translocation of phosphorylated MARCKS in cells expressing the SCA14 mutant γPKC. These findings suggest that γPKC is involved in the regulation of the actin cytoskeleton and macropinocytosis in HeLa cells, while SCA14 mutant γPKC fails to regulate these processes due to its reduced kinase activity at the plasma membrane. This property might be involved in

Computational modeling identifies key gene regulatory interactions underlying phenobarbital-mediated tumor promotion

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Luisier, Raphaëlle; Unterberger, Elif B.; Goodman, Jay I.; Schwarz, Michael; Moggs, Jonathan; Terranova, Rémi; van Nimwegen, Erik

2014-01-01

Gene regulatory interactions underlying the early stages of non-genotoxic carcinogenesis are poorly understood. Here, we have identified key candidate regulators of phenobarbital (PB)-mediated mouse liver tumorigenesis, a well-characterized model of non-genotoxic carcinogenesis, by applying a new computational modeling approach to a comprehensive collection of in vivo gene expression studies. We have combined our previously developed motif activity response analysis (MARA), which models gene expression patterns in terms of computationally predicted transcription factor binding sites with singular value decomposition (SVD) of the inferred motif activities, to disentangle the roles that different transcriptional regulators play in specific biological pathways of tumor promotion. Furthermore, transgenic mouse models enabled us to identify which of these regulatory activities was downstream of constitutive androstane receptor and β-catenin signaling, both crucial components of PB-mediated liver tumorigenesis. We propose novel roles for E2F and ZFP161 in PB-mediated hepatocyte proliferation and suggest that PB-mediated suppression of ESR1 activity contributes to the development of a tumor-prone environment. Our study shows that combining MARA with SVD allows for automated identification of independent transcription regulatory programs within a complex in vivo tissue environment and provides novel mechanistic insights into PB-mediated hepatocarcinogenesis. PMID:24464994

Tumor suppressor BLU inhibits proliferation of nasopharyngeal carcinoma cells by regulation of cell cycle, c-Jun N-terminal kinase and the cyclin D1 promoter

International Nuclear Information System (INIS)

Zhang, Xiangning; Liu, Hui; Li, Binbin; Huang, Peichun; Shao, Jianyong; He, Zhiwei

2012-01-01

Tumor suppressor genes function to regulate and block tumor cell proliferation. To explore the mechanisms underlying the tumor suppression of BLU/ZMYND10 gene on a frequently lost human chromosomal region, an adenoviral vector with BLU cDNA insert was constructed. BLU was re-expressed in nasopharyngeal carcinoma cells by transfection or viral infection. Clonogenic growth was assayed; cell cycle was analyzed by flow cytometry-based DNA content detection; c-Jun N-terminal kinase (JNK) and cyclin D1 promoter activities were measured by reporter gene assay, and phosphorylation was measured by immunoblotting. The data for each pair of groups were compared with Student t tests. BLU inhibits clonogenic growth of nasopharyngeal carcinoma cells, arrests cell cycle at G1 phase, downregulates JNK and cyclin D1 promoter activities, and inhibits phosphorylation of c-Jun. BLU inhibits growth of nasopharyngeal carcinoma cells by regulation of the JNK-cyclin D1 axis to exert tumor suppression

Tumor Cells Express FcγRl Which Contributes to Tumor Cell Growth and a Metastatic Phenotype

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M. Bud Nelson

2001-01-01

Full Text Available High levels of circulating immune complexes containing tumor-associated antigens are associated with a poor prognosis for individuals with cancer. The ability of B cells, previously exposed to tumor-associated antigens, to promote both in vitro and in vivo tumor growth formed the rationale to evaluate the mechanism by which immune complexes may promote tumor growth. In elucidating this mechanism, FcγRl expression by tumor cells was characterized by flow cytometry, polymerase chain reaction, and sequence analysis. Immune complexes containing shed tumor antigen and anti-shed tumor antigen Ab cross-linked FcγRl-expressing tumor cells, which resulted in an induction of tumor cell proliferation and of shed tumor antigen production. Use of selective tyrosine kinase inhibitors demonstrated that tumor cell proliferation induced by immune complex cross-linking of FcγRl is dependent on the tyrosine kinase signal transduction pathway. A selective inhibitor of phosphatidylinositol-3 kinase also inhibited this induction of tumor cell proliferation. These findings support a role for immune complexes and FcγRl expression by tumor cells in augmentation of tumor growth and a metastatic phenotype.

Detoxification of Toxic Phorbol Esters from Malaysian Jatropha curcas Linn. Kernel by Trichoderma spp. and Endophytic Fungi

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Azhar Najjar

2014-02-01

Full Text Available The presence of phorbol esters (PEs with toxic properties limits the use of Jatropha curcas kernel in the animal feed industry. Therefore, suitable methods to detoxify PEs have to be developed to render the material safe as a feed ingredient. In the present study, the biological treatment of the extracted PEs-rich fraction with non-pathogenic fungi (Trichoderma harzianum JQ350879.1, T. harzianum JQ517493.1, Paecilomyces sinensis JQ350881.1, Cladosporium cladosporioides JQ517491.1, Fusarium chlamydosporum JQ350882.1, F. chlamydosporum JQ517492.1 and F. chlamydosporum JQ350880.1 was conducted by fermentation in broth cultures. The PEs were detected by liquid chromatography-diode array detector-electrospray ionization mass spectrometry (LC-DAD-ESIMS and quantitatively monitored by HPLC using phorbol-12-myristate 13-acetate as the standard. At day 30 of incubation, two T. harzianum spp., P. sinensis and C. cladosporioides significantly (p < 0.05 removed PEs with percentage losses of 96.9%–99.7%, while F. chlamydosporum strains showed percentage losses of 88.9%–92.2%. All fungal strains could utilize the PEs-rich fraction for growth. In the cytotoxicity assay, cell viabilities of Chang liver and NIH 3T3 fibroblast cell lines were less than 1% with the untreated PEs-rich fraction, but 84.3%–96.5% with the fungal treated PEs-rich fraction. There was no inhibition on cell viability for normal fungal growth supernatants. To conclude, Trichoderma spp., Paecilomyces sp. and Cladosporium sp. are potential microbes for the detoxification of PEs.

Phorbol Esters Isolated from Jatropha Meal Induced Apoptosis-Mediated Inhibition in Proliferation of Chang and Vero Cell Lines

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Syahida Ahmad

2012-10-01

Full Text Available The direct feeding of Jatropha meal containing phorbol esters (PEs indicated mild to severe toxicity symptoms in various organs of different animals. However, limited information is available on cellular and molecular mechanism of toxicity caused by PEs present in Jatropha meal. Thus, the present study was conducted to determine the cytotoxic and mode of action of PEs isolated from Jatropha meal using human hepatocyte (Chang and African green monkey kidney (Vero cell lines. The results showed that isolated PEs inhibited cell proliferation in a dose-dependent manner in both cell lines with the CC50 of 125.9 and 110.3 μg/mL, respectively. These values were compatible to that of phorbol 12-myristate 13-acetate (PMA values as positive control i.e., 124.5 and 106.3 μg/mL respectively. Microscopic examination, flow cytometry and DNA fragmentation results confirmed cell death due to apoptosis upon treatment with PEs and PMA at CC50 concentration for 24 h in both cell lines. The Western blot analysis revealed the overexpression of PKC-δ and activation of caspase-3 proteins which could be involved in the mechanism of action of PEs and PMA. Consequently, the PEs isolated form Jatropha meal caused toxicity and induced apoptosis-mediated proliferation inhibition toward Chang and Vero cell lines involving over-expression of PKC-δ and caspase-3 as their mode of actions.

Local anesthetics inhibit induction of ornithine decarboxylase by the tumor promoter 12-O-tetradecanoylphorbol 13-acetate.

OpenAIRE

Yuspa, S H; Lichti, U; Ben, T

1980-01-01

The induction of ornithine decarboxylase (L-ornithine carboxy-lyase, EC 4.1.1.17) activity in mouse epidermal cells in vivo and in vitro occurs rapidly after exposure to the tumor promoter 12-O-tetradecanoylphorbol 13-acetate (TPA). This induction has characteristics of a cell surface receptor-mediated process. Local anesthetics modify a variety of cellular responses mediated by membrane receptors. When cultured mouse epidermal cells were exposed to the local anesthetics lidocaine, tetracaine...

Tumor-Targeting Salmonella typhimurium A1-R Promotes Tumoricidal CD8+ T Cell Tumor Infiltration and Arrests Growth and Metastasis in a Syngeneic Pancreatic-Cancer Orthotopic Mouse Model.

Science.gov (United States)

Murakami, Takashi; Hiroshima, Yukihiko; Zhang, Yong; Zhao, Ming; Kiyuna, Tasuku; Hwang, Ho Kyoung; Miyake, Kentaro; Homma, Yuki; Mori, Ryutaro; Matsuyama, Ryusei; Chishima, Takashi; Ichikawa, Yasushi; Tanaka, Kuniya; Bouvet, Michael; Endo, Itaru; Hoffman, Robert M

2018-01-01

The present study determined the effect of the tumor-targeting strain Salmonella typhimurium A1-R (S. typhimurium A1-R) on CD8 + tumor-infiltrating lymphocytes (TILs) in a syngeneic pancreatic-cancer orthotopic mouse model. The effect of tumor-targeting S. typhimurium A1-R on CD8 + TILs was determined on the Pan02 murine pancreatic-adenocarcinoma implanted orthotopically in the pancreatic tail of C57BL/6 immunocompromised mice. Three weeks after orthotopic implantation, mice were randomized as follows G1: untreated control group (n = 8); and G2: S. typhimurium A1-R-treatment group (n = 8, 1 × 10 7 colony forming units [CFU]/body, iv, weekly, 3 weeks). On the 22nd day from initial treatment, all mice were sacrificed and tumors were harvested. The tumor-volume ratio was defined as ratio of tumor volume on the 22nd day relative to the 1st day. The tumor volume ratio was significantly lower in the S. typhimurium A1-R-treated group (G2) (3.0 ± 2.8) than the untreated control (G1) (39.9 ± 30.7, P R-treated mice (G2). Six mice in G1 had peritoneal dissemination, whereas no mice showed peritoneal dissemination in G2 (P R promotes CD8 + T cell infiltration and inhibition of tumor growth and metastasis. J. Cell. Biochem. 119: 634-639, 2018. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.

The effect of dietary glycine on the hepatic tumor promoting activity of polychlorinated biphenyls (PCBs) in rats

International Nuclear Information System (INIS)

Bunaciu, Rodica Petruta; Tharappel, Job C.; Lehmler, Hans-Joachim; Kania-Korwel, Izabela; Robertson, Larry W.; Srinivasan, Cidambi; Spear, Brett T.; Glauert, Howard P.

2007-01-01

Polychlorinated biphenyls (PCBs) are ubiquitious lipophilic environmental pollutants. Some of the PCB congeners and mixtures of congeners have tumor promoting activity in rat liver. The mechanism of their activity is not fully understood and is likely to be multifactorial. The aim of this study was to investigate if the resident liver macrophages, Kupffer cells, are important in the promoting activity of PCBs. The hypothesis of this study was that the inhibition of Kupffer cell activity would inhibit hepatic tumor promotion by PCBs in rats. To test our hypothesis, we studied the effects of Kupffer cell inhibition by dietary glycine (an inhibitor of Kupffer cell secretory activity) in a rat two-stage hepatocarcinogenesis model using 2,2',4,4',5,5'-hexachlorobiphenyl (PCB-153, a non-dioxin-like PCB) or 3,3',4,4'-tetrachlorobiphenyl (PCB-77, a dioxin-like PCB) as promoters. Diethylnitrosamine (DEN, 150 mg/kg) was administered to female Sprague-Dawley rats, which were then placed on an unrefined diet containing 5% glycine (or casein as nitrogen control) starting two weeks after DEN administration. On the third day after starting the diets, rats received PCB-77 (300 μmol/kg), PCB-153 (300 μmol/kg), or corn oil by i.p. injection. The rats received a total of 4 PCB injections, administered every 14 days. The rats were euthanized on the 10th day after the last PCB injection, and the formation of altered hepatic foci expressing placental glutathione S-transferase (PGST) and the rate of DNA synthesis in these foci and in the normal liver tissue were determined. Glycine did not significantly affect foci number or volume. PCB-153 did not significantly increase the focal volume, but increased the number of foci per liver, but only in the rats not fed glycine; PCB-77 increased both the foci number and their volume in both glycine-fed and control rats. Glycine did not alter the PCB content of the liver, but did increase the activity of 7-benzyloxyresorufin O-dealkylase (BROD

Relative expression of rRNA transcripts and 45S rDNA promoter methylation status are dysregulated in tumors in comparison with matched-normal tissues in breast cancer.

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Karahan, Gurbet; Sayar, Nilufer; Gozum, Gokcen; Bozkurt, Betul; Konu, Ozlen; Yulug, Isik G

2015-06-01

Ribosomal RNA (rRNA) expression, one of the most important factors regulating ribosome production, is primarily controlled by a CG-rich 45 S rDNA promoter. However, the DNA methylation state of the 45 S rDNA promoter, as well as its effect on rRNA gene expression in types of human cancers is controversial. In the present study we analyzed the methylation status of the rDNA promoter (-380 to +53 bp) as well as associated rRNA expression levels in breast cancer cell lines and breast tumor-normal tissue pairs. We found that the aforementioned regulatory region was extensively methylated (74-96%) in all cell lines and in 68% (13/19 tumor-normal pairs) of the tumors. Expression levels of rRNA transcripts 18 S, 28 S, 5.8 S and 45 S external transcribed spacer (45 S ETS) greatly varied in the breast cancer cell lines regardless of their methylation status. Analyses of rRNA transcript expression levels in the breast tumor and normal matched tissues showed no significant difference when normalized with TBP. On the other hand, using the geometric mean of the rRNA expression values (GM-rRNA) as reference enabled us to identify significant changes in the relative expression of rRNAs in the tissue samples. We propose GM-rRNA normalization as a novel strategy to analyze expression differences between rRNA transcripts. Accordingly, the 18S rRNA/GM-rRNA ratio was significantly higher whereas the 5.8S rRNA/GM-rRNA ratio was significantly lower in breast tumor samples than this ratio in the matched normal samples. Moreover, the 18S rRNA/GM-rRNA ratio was negatively correlated with the 45 S rDNA promoter methylation level in the normal breast tissue samples, yet not in the breast tumors. Significant correlations observed between the expression levels of rRNA transcripts in the normal samples were lost in the tumor samples. We showed that the expression of rRNA transcripts may not be based solely on promoter methylation. Carcinogenesis may cause dysregulation of the correlation

Concomitant apoptosis and regeneration of liver cells as a mechanism of liver-tumor promotion by β-naphthoflavone involving TNFα-signaling due to oxidative cellular stress in rats

International Nuclear Information System (INIS)

Kuwata, Kazunori; Shibutani, Makoto; Hayashi, Hitomi; Shimamoto, Keisuke; Hayashi, Shim-Mo; Suzuki, Kazuhiko; Mitsumori, Kunitoshi

2011-01-01

β-Naphthoflavone (BNF) is a strong inducer of cytochrome P450 1A enzymes, and exerts liver tumor-promoting activity through enhancement of oxidative stress responses in rats. This study investigated the role of the tissue environment surrounding hepatocellular preneoplastic lesions in the early tumor-promotion stage by BNF, using enzymatically modified isoquercitrin (EMIQ) as an anti-oxidative chemopreventive agent. Male F344 rats were fed a diet containing BNF (0.5%) for 6 weeks, with or without EMIQ (0.2%) in the drinking water, 2 weeks after initiation with N-diethylnitrosamine, and were subjected to two-thirds partial hepatectomy 1 week after starting BNF-promotion. BNF-treatment increased concentrations of liver thiobarbituric acid-reactive substances, single liver cells expressing glutathione S-transferase placental form or heme oxygenase (HO)-1, and concomitant apoptosis and proliferation of liver cells. Transcript upregulation of anti-oxidative enzymes (Aldh1a1 and Nqo1), cell cycle-related molecules (Cdc20 and Cdkn2b) and inflammation-related molecules including proinflammatory cytokines (Ccl2, Col1a1, Il6, Nos2 and Serpine1) was also evident. Furthermore, BNF increased HO-1-expressing Kupffer cells and liver cells expressing tumor necrosis factor receptor 1 (TNFR1) and the TNFR1-associated death domain. Most of these BNF-induced fluctuations disappeared or were suppressed by EMIQ in conjunction with suppression of tumor-promotion. Tnf transcript levels with BNF were also suppressed by EMIQ. These results suggest that BNF-induced oxidative stress causes single liver cell toxicity, allowing subsequent concomitant apoptosis and regeneration involving inflammatory responses including TNFα-signaling, contributing to tumor promotion. Kupffer cells may act to protect against inflammatory stimuli induced as a result of oxidative cellular stress by BNF, causing proinflammatory cytokine level fluctuations.

The hypoxia-inducible factor-responsive proteins semaphorin 4D and vascular endothelial growth factor promote tumor growth and angiogenesis in oral squamous cell carcinoma

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Zhou, Hua; Yang, Ying-Hua [Department of Oncology and Diagnostic Sciences, University of Maryland Dental School, 650W. Baltimore Street, 7-North, Baltimore, MD 21201 (United States); Binmadi, Nada O. [Department of Oncology and Diagnostic Sciences, University of Maryland Dental School, 650W. Baltimore Street, 7-North, Baltimore, MD 21201 (United States); Department of Oral Basic and Clinical Sciences, King Abdulaziz University, Jeddah 21589 (Saudi Arabia); Proia, Patrizia [Department of Oncology and Diagnostic Sciences, University of Maryland Dental School, 650W. Baltimore Street, 7-North, Baltimore, MD 21201 (United States); Department of Sports Science (DISMOT), University of Palermo, Via Eleonora Duse 2 90146, Palermo (Italy); Basile, John R., E-mail: jbasile@umaryland.edu [Department of Oncology and Diagnostic Sciences, University of Maryland Dental School, 650W. Baltimore Street, 7-North, Baltimore, MD 21201 (United States); Greenebaum Cancer Center, 22S. Greene Street, Baltimore, MD 21201 (United States)

2012-08-15

Growth and metastasis of solid tumors requires induction of angiogenesis to ensure the delivery of oxygen, nutrients and growth factors to rapidly dividing transformed cells. Through either mutations, hypoxia generated by cytoreductive therapies, or when a malignancy outgrows its blood supply, tumor cells undergo a change from an avascular to a neovascular phenotype, a transition mediated by the hypoxia-inducible factor (HIF) family of transcriptional regulators. Vascular endothelial growth factor (VEGF) is one example of a gene whose transcription is stimulated by HIF. VEGF plays a crucial role in promoting tumor growth and survival by stimulating new blood vessel growth in response to such stresses as chemotherapy or radiotherapy-induced hypoxia, and it therefore has become a tempting target for neutralizing antibodies in the treatment of advanced neoplasms. Emerging evidence has shown that the semaphorins, proteins originally associated with control of axonal growth and immunity, are regulated by changes in oxygen tension as well and may play a role in tumor-induced angiogenesis. Through the use of RNA interference, in vitro and in vivo angiogenesis assays and tumor xenograft experiments, we demonstrate that expression of semaphorin 4D (SEMA4D), which is under the control of the HIF-family of transcription factors, cooperates with VEGF to promote tumor growth and vascularity in oral squamous cell carcinoma (OSCC). We use blocking antibodies to show that targeting SEMA4D function along with VEGF could represent a novel anti-angiogenic therapeutic strategy for the treatment of OSCC and other solid tumors. -- Highlights: Black-Right-Pointing-Pointer Similar to VEGF, SEMA4D promotes angiogenesis in vitro and in vivo. Black-Right-Pointing-Pointer Both VEGF and SEMA4D are produced by OSCC cells in a HIF-dependent manner. Black-Right-Pointing-Pointer These factors combine to elicit a robust pro-angiogenic phenotype in OSCC. Black-Right-Pointing-Pointer Anti-SEMA4D

The hypoxia-inducible factor-responsive proteins semaphorin 4D and vascular endothelial growth factor promote tumor growth and angiogenesis in oral squamous cell carcinoma

International Nuclear Information System (INIS)

Zhou, Hua; Yang, Ying-Hua; Binmadi, Nada O.; Proia, Patrizia; Basile, John R.

2012-01-01

Growth and metastasis of solid tumors requires induction of angiogenesis to ensure the delivery of oxygen, nutrients and growth factors to rapidly dividing transformed cells. Through either mutations, hypoxia generated by cytoreductive therapies, or when a malignancy outgrows its blood supply, tumor cells undergo a change from an avascular to a neovascular phenotype, a transition mediated by the hypoxia-inducible factor (HIF) family of transcriptional regulators. Vascular endothelial growth factor (VEGF) is one example of a gene whose transcription is stimulated by HIF. VEGF plays a crucial role in promoting tumor growth and survival by stimulating new blood vessel growth in response to such stresses as chemotherapy or radiotherapy-induced hypoxia, and it therefore has become a tempting target for neutralizing antibodies in the treatment of advanced neoplasms. Emerging evidence has shown that the semaphorins, proteins originally associated with control of axonal growth and immunity, are regulated by changes in oxygen tension as well and may play a role in tumor-induced angiogenesis. Through the use of RNA interference, in vitro and in vivo angiogenesis assays and tumor xenograft experiments, we demonstrate that expression of semaphorin 4D (SEMA4D), which is under the control of the HIF-family of transcription factors, cooperates with VEGF to promote tumor growth and vascularity in oral squamous cell carcinoma (OSCC). We use blocking antibodies to show that targeting SEMA4D function along with VEGF could represent a novel anti-angiogenic therapeutic strategy for the treatment of OSCC and other solid tumors. -- Highlights: ► Similar to VEGF, SEMA4D promotes angiogenesis in vitro and in vivo. ► Both VEGF and SEMA4D are produced by OSCC cells in a HIF-dependent manner. ► These factors combine to elicit a robust pro-angiogenic phenotype in OSCC. ► Anti-SEMA4D blocking antibody inhibits Plexin-B1 activation. ► SEMA4D is a valid anti-angiogenic target in the

Inactivation of the Tumor Suppressor Genes Causing the Hereditary Syndromes Predisposing to Head and Neck Cancer via Promoter Hypermethylation in Sporadic Head and Neck Cancers

OpenAIRE

Smith, Ian M.; Mithani, Suhail K.; Mydlarz, Wojciech K.; Chang, Steven S.; Califano, Joseph A.

2010-01-01

Fanconi anemia (FA) and dyskeratosis congenita (DC) are rare inherited syndromes that cause head and neck squamous cell cancer (HNSCC). Prior studies of inherited forms of cancer have been extremely important in elucidating tumor suppressor genes inactivated in sporadic tumors. Here, we studied whether sporadic tumors have epigenetic silencing of the genes causing the inherited forms of HNSCC. Using bisulfite sequencing, we investigated the incidence of promoter hypermethylation of the 17 Fan...

Occular and dermal toxicity of Jatropha curcas phorbol esters.

Science.gov (United States)

Devappa, Rakshit K; Roach, Joy S; Makkar, Harinder P S; Becker, Klaus

2013-08-01

Jatropha curcas seeds are a promising feedstock for biodiesel production. However, Jatropha seed oil and other plant parts are toxic due to the presence of phorbol esters (PEs). The ever-increasing cultivation of toxic genotype of J. curcas runs the risk of increased human exposure to Jatropha products. In the present study, effects of J. curcas oil (from both toxic and nontoxic genotypes), purified PEs-rich extract and purified PEs (factors C1, C2, C(3mixture), (C4+C5)) on reconstituted human epithelium (RHE) and human corneal epithelium (HCE) were evaluated in vitro. The PEs were purified from toxic Jatropha oil. In both RHE and HCE, the topical application of PEs containing samples produced severe cellular alterations such as marked oedema, presence of less viable cell layers, necrosis and/or partial tissue disintegration in epithelium and increased inflammatory response (interleukin-1α and prostaglandin E2). When compared to toxic oil, histological alterations and inflammatory response were less evident (PJatropha PEs are toxic towards RHE and HCE models, which represents dermal and occular toxicity respectively. Data obtained from this study would aid in the development of safety procedures for Jatropha biodiesel industries. It is advised to use protective gloves and glasses when handling PEs containing Jatropha products. Copyright © 2013 Elsevier Inc. All rights reserved.

Interleukin-6 induces an epithelial-mesenchymal transition phenotype in human adamantinomatous craniopharyngioma cells and promotes tumor cell migration

Science.gov (United States)

Zhou, Jie; Zhang, Chao; Pan, Jun; Chen, Ligang; Qi, Song-Tao

2017-01-01

Total resection of adamantinomatous craniopharyngioma (ACP) is complex and often leads to postoperative recurrence. This is due to the tendency of the tumor to invade the surrounding brain tissue and the generation of a local inflammatory state between the tumor cells and parenchyma. While there is evidence to suggest that interleukin-6 (IL-6) induces craniopharyngioma (CP)-associated inflammation, particularly in ACP, the role of IL-6 in the progression of ACP remains unclear. The results of the present study demonstrated that CP inflammation was associated with pathological classification, extent of surgery, degree of calcification and postoperative hypothalamic status scale. Cytokine antibody arrays were conducted to measure the expression of IL-6 and other inflammatory factors in tumor tissues in response to various levels of inflammatory exposure. IL-6, IL-6 receptor (IL-6R) and glycoprotein 130 expression was detected by immunohistochemistry. In addition, an ELISA was performed to quantify the levels of soluble IL-6R (sIL-6R) in the cystic fluid and supernatants of ACP cells and tumor-associated fibroblasts. These measurements demonstrated that ACP cells produce IL-6 and its associated proteins. In addition, the results revealed that while the viability of ACP cells was not affected, the migration of ACP cells was promoted by IL-6 treatment in a concentration-dependent manner. Conversely, treatment with an IL-6-blocking monoclonal antibody significantly decreased the migration of ACP cells. In addition, IL-6 treatment increased the expression of vimentin and decreased the expression of E-cadherin in a dose-dependent manner. The findings of the present study demonstrate that IL-6 may promote migration in vitro via the classic- and trans-signaling pathways by inducing epithelial-mesenchymal transition in ACP cell cultures. PMID:28487953

Epigenetic profiling of cutaneous T-cell lymphoma: promoter hypermethylation of multiple tumor suppressor genes including BCL7a, PTPRG, and p73.

Science.gov (United States)

van Doorn, Remco; Zoutman, Willem H; Dijkman, Remco; de Menezes, Renee X; Commandeur, Suzan; Mulder, Aat A; van der Velden, Pieter A; Vermeer, Maarten H; Willemze, Rein; Yan, Pearlly S; Huang, Tim H; Tensen, Cornelis P

2005-06-10

To analyze the occurrence of promoter hypermethylation in primary cutaneous T-cell lymphoma (CTCL) on a genome-wide scale, focusing on epigenetic alterations with pathogenetic significance. DNA isolated from biopsy specimens of 28 patients with CTCL, including aggressive CTCL entities (transformed mycosis fungoides and CD30-negative large T-cell lymphoma) and an indolent entity (CD30-positive large T-cell lymphoma), were investigated. For genome-wide DNA methylation screening, differential methylation hybridization using CpG island microarrays was applied, which allows simultaneous detection of the methylation status of 8640 CpG islands. Bisulfite sequence analysis was applied for confirmation and detection of hypermethylation of eight selected tumor suppressor genes. The DNA methylation patterns of CTCLs emerging from differential methylation hybridization analysis included 35 CpG islands hypermethylated in at least four of the 28 studied CTCL samples when compared with benign T-cell samples. Hypermethylation of the putative tumor suppressor genes BCL7a (in 48% of CTCL samples), PTPRG (27%), and thrombospondin 4 (52%) was confirmed and demonstrated to be associated with transcriptional downregulation. BCL7a was hypermethylated at a higher frequency in aggressive (64%) than in indolent (14%) CTCL entities. In addition, the promoters of the selected tumor suppressor genes p73 (48%), p16 (33%), CHFR (19%), p15 (10%), and TMS1 (10%) were hypermethylated in CTCL. Malignant T cells of patients with CTCL display widespread promoter hypermethylation associated with inactivation of several tumor suppressor genes involved in DNA repair, cell cycle, and apoptosis signaling pathways. In view of this, CTCL may be amenable to treatment with demethylating agents.

Biological stoichiometry in tumor micro-environments.

Directory of Open Access Journals (Sweden)

Irina Kareva

Full Text Available Tumors can be viewed as evolving ecological systems, in which heterogeneous populations of cancer cells compete with each other and somatic cells for space and nutrients within the ecosystem of the human body. According to the growth rate hypothesis (GRH, increased phosphorus availability in an ecosystem, such as the tumor micro-environment, may promote selection within the tumor for a more proliferative and thus potentially more malignant phenotype. The applicability of the GRH to tumor growth is evaluated using a mathematical model, which suggests that limiting phosphorus availability might promote intercellular competition within a tumor, and thereby delay disease progression. It is also shown that a tumor can respond differently to changes in its micro-environment depending on the initial distribution of clones within the tumor, regardless of its initial size. This suggests that composition of the tumor as a whole needs to be evaluated in order to maximize the efficacy of therapy.

Effect of wortmannin and phorbol ester on Paramecium fluid-phase uptake in the presence of transferrin

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J Wiejak

2009-12-01

Full Text Available The kinetics of the uptake of the fluid phase marker Lucifer Yellow (LY, and its alteration by wortmannin, an inhibitor of phosphatidylinositol-3 kinase (PI-3K, and the PKC modulators: GF 109203 X, an inhibitor, and phorbol ester, an activator was studied in eukaryotic model Paramecium aurelia. Spectrophotometric quantification of LY accumulation was performed in the presence or absence of transferrin, a marker of receptor-mediated endocytosis. Internalization of LY showed a curvilinear kinetics: the high initial rate of LYuptake (575 ng LY/ mg protein /hr decreased almost 5-fold within 15 min, reaching plateau at 126 ng/ mg protein /hr. Transferrin induced a small increase (7.5% in the fluid phase uptake rate (after 5 min followed by a small decrease at longer incubation times. Lucifer Yellow and transferrin (visualized by streptavidin– FITC were localized in Paramecium by 3-D reconstruction by confocal microscopy. LY showed a scattered, diffuse fluorescence typical of fluid phase uptake whereas transferrin accumulated in membrane-surrounded endosomes. Wortmannin did not affect LY accumulation but decreased it when transferrin was present in the incubation medium. This suggests an effect on the transferrin uptake pathway, presumably on the stage of internalization in “mixing” endosomes to which transferrin and LY were targeted. Phorbol ester diminished LY accumulation by 22% and this effect persisted up to 25 min of incubation. PKC inhibitor did not affect LY uptake. However, in the presence of transferrin, the LY uptake increased within the first 15 minutes followed by a rapid 20% decrease in comparison to the control. Such an effect of PKC modulators suggests that PMA action on fluid phase uptake is not directly mediated by PKC.

Regulation of Tumor Progression by Programmed Necrosis

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Su Yeon Lee

2018-01-01

Full Text Available Rapidly growing malignant tumors frequently encounter hypoxia and nutrient (e.g., glucose deprivation, which occurs because of insufficient blood supply. This results in necrotic cell death in the core region of solid tumors. Necrotic cells release their cellular cytoplasmic contents into the extracellular space, such as high mobility group box 1 (HMGB1, which is a nonhistone nuclear protein, but acts as a proinflammatory and tumor-promoting cytokine when released by necrotic cells. These released molecules recruit immune and inflammatory cells, which exert tumor-promoting activity by inducing angiogenesis, proliferation, and invasion. Development of a necrotic core in cancer patients is also associated with poor prognosis. Conventionally, necrosis has been thought of as an unregulated process, unlike programmed cell death processes like apoptosis and autophagy. Recently, necrosis has been recognized as a programmed cell death, encompassing processes such as oncosis, necroptosis, and others. Metabolic stress-induced necrosis and its regulatory mechanisms have been poorly investigated until recently. Snail and Dlx-2, EMT-inducing transcription factors, are responsible for metabolic stress-induced necrosis in tumors. Snail and Dlx-2 contribute to tumor progression by promoting necrosis and inducing EMT and oncogenic metabolism. Oncogenic metabolism has been shown to play a role(s in initiating necrosis. Here, we discuss the molecular mechanisms underlying metabolic stress-induced programmed necrosis that promote tumor progression and aggressiveness.

Long-term High Fat Ketogenic Diet Promotes Renal Tumor Growth in a Rat Model of Tuberous Sclerosis.

Science.gov (United States)

Liśkiewicz, Arkadiusz D; Kasprowska, Daniela; Wojakowska, Anna; Polański, Krzysztof; Lewin-Kowalik, Joanna; Kotulska, Katarzyna; Jędrzejowska-Szypułka, Halina

2016-02-19

Nutritional imbalance underlies many disease processes but can be very beneficial in certain cases; for instance, the antiepileptic action of a high fat and low carbohydrate ketogenic diet. Besides this therapeutic feature it is not clear how this abundant fat supply may affect homeostasis, leading to side effects. A ketogenic diet is used as anti-seizure therapy i.a. in tuberous sclerosis patients, but its impact on concomitant tumor growth is not known. To examine this we have evaluated the growth of renal lesions in Eker rats (Tsc2+/-) subjected to a ketogenic diet for 4, 6 and 8 months. In spite of existing opinions about the anticancer actions of a ketogenic diet, we have shown that this anti-seizure therapy, especially in its long term usage, leads to excessive tumor growth. Prolonged feeding of a ketogenic diet promotes the growth of renal tumors by recruiting ERK1/2 and mTOR which are associated with the accumulation of oleic acid and the overproduction of growth hormone. Simultaneously, we observed that Nrf2, p53 and 8-oxoguanine glycosylase α dependent antitumor mechanisms were launched by the ketogenic diet. However, the pro-cancerous mechanisms finally took the ascendency by boosting tumor growth.

Tumor Cells and Tumor-Associated Macrophages: Secreted Proteins as Potential Targets for Therapy

OpenAIRE

Baay, Marc; Brouwer, Anja; Pauwels, Patrick; Peeters, Marc; Lardon, Filip

2011-01-01

Inflammatory pathways, meant to defend the organism against infection and injury, as a byproduct, can promote an environment which favors tumor growth and metastasis. Tumor-associated macrophages (TAMs), which constitute a significant part of the tumor-infiltrating immune cells, have been linked to the growth, angiogenesis, and metastasis of a variety of cancers, most likely through polarization of TAMs to the M2 (alternative) phenotype. The interaction between tumor cells and macrophages pro...

FANCD2 Maintains Fork Stability in BRCA1/2-Deficient Tumors and Promotes Alternative End-Joining DNA Repair

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Zeina Kais

2016-06-01

Full Text Available BRCA1/2 proteins function in homologous recombination (HR-mediated DNA repair and cooperate with Fanconi anemia (FA proteins to maintain genomic integrity through replication fork stabilization. Loss of BRCA1/2 proteins results in DNA repair deficiency and replicative stress, leading to genomic instability and enhanced sensitivity to DNA-damaging agents. Recent studies have shown that BRCA1/2-deficient tumors upregulate Polθ-mediated alternative end-joining (alt-EJ repair as a survival mechanism. Whether other mechanisms maintain genomic integrity upon loss of BRCA1/2 proteins is currently unknown. Here we show that BRCA1/2-deficient tumors also upregulate FANCD2 activity. FANCD2 is required for fork protection and fork restart in BRCA1/2-deficient tumors. Moreover, FANCD2 promotes Polθ recruitment at sites of damage and alt-EJ repair. Finally, loss of FANCD2 in BRCA1/2-deficient tumors enhances cell death. These results reveal a synthetic lethal relationship between FANCD2 and BRCA1/2, and they identify FANCD2 as a central player orchestrating DNA repair pathway choice at the replication fork.

Deoxypodophyllotoxin suppresses tumor vasculature in HUVECs by promoting cytoskeleton remodeling through LKB1-AMPK dependent Rho A activatio.

Science.gov (United States)

Wang, Yurong; Wang, Bin; Guerram, Mounia; Sun, Li; Shi, Wei; Tian, Chongchong; Zhu, Xiong; Jiang, Zhenzhou; Zhang, Luyong

2015-10-06

Angiogenesis plays a critical role in the growth and metastasis of tumors, which makes it an attractive target for anti-tumor drug development. Deoxypodophyllotoxin (DPT), a natural product isolated from Anthriscus sylvestris, inhibits cell proliferation and migration in various cancer cell types. Our previous studies indicate that DPT possesses both anti-angiogenic and vascular-disrupting activities. Although the RhoA/ RhoA kinase (ROCK) signaling pathway is implicated in DPT-stimulated cytoskeleton remodeling and tumor vasculature suppressing, the detailed mechanisms by which DPT mediates these effects are poorly understood. In the current study, we found that DPT promotes cytoskeleton remodeling in human umbilical vein endothelial cells (HUVECs) via stimulation of AMP-activated protein kinase (AMPK) and that this effect is abolished by either treatment with a selective AMPK inhibitor or knockdown. Moreover, the cellular levels of LKB1, a kinase upstream of AMPK, were enhanced following DPT exposure. DPT-induced activation of AMPK in tumor vasculature effect was also verified by transgenic zebrafish (VEGFR2:GFP), Matrigel plug assay, and xenograft model in nude mice. The present findings may lay the groundwork for a novel therapeutic approach in treating cancer.

Muscarinic agonists and phorbol esters increase tyrosine phosphorylation of a 40-kilodalton protein in hippocampal slices

International Nuclear Information System (INIS)

Stratton, K.R.; Worley, P.F.; Huganir, R.L.; Baraban, J.M.

1989-01-01

The authors have used the hippocampal slice preparation to investigate the regulation of protein tyrosine phosphorylation in brain. After pharmacological treatment of intact slices, proteins were separated by electrophoresis, and levels of protein tyrosine phosphorylation were assessed by immunoblotting with specific anti-phosphotyrosine antibodies. Phorbol esters, activators of the serine- and threonine-phosphorylating enzyme protein kinase C, selectively increase tyrosine phosphorylation of a soluble protein with an apparent molecular mass of approximately 40 kilodaltons. Muscarinic agonists such as carbachol and oxotremorine M that strongly activate the inositol phospholipid system also increase tyrosine phosphorylation of this protein. Neurotransmitter activation of the inositol phospholipid system and protein kinase C appears to trigger a cascade leading to increased tyrosine phosphorylation

Hypoxia Promotes Tumor Growth in Linking Angiogenesis to Immune Escape

OpenAIRE

Chouaib, Salem; Messai, Yosra; Couve, Sophie; Escudier, Bernard; Hasmim, Meriem; Noman, Muhammad Zaeem

2012-01-01

Despite the impressive progress over the past decade, in the field of tumor immunology, such as the identification of tumor antigens and antigenic peptides, there are still many obstacles in eliciting an effective immune response to eradicate cancer. It has become increasingly clear that tumor microenvironment plays a crucial role in the control of immune protection. Tumors have evolved to utilize hypoxic stress to their own advantage by activating key biochemical and cellular pathways that a...

Autocrine Effects of Tumor-Derived Complement

Directory of Open Access Journals (Sweden)

Min Soon Cho

2014-03-01

Full Text Available We describe a role for the complement system in enhancing cancer growth. Cancer cells secrete complement proteins that stimulate tumor growth upon activation. Complement promotes tumor growth via a direct autocrine effect that is partially independent of tumor-infiltrating cytotoxic T cells. Activated C5aR and C3aR signal through the PI3K/AKT pathway in cancer cells, and silencing the PI3K or AKT gene in cancer cells eliminates the progrowth effects of C5aR and C3aR stimulation. In patients with ovarian or lung cancer, higher tumoral C3 or C5aR mRNA levels were associated with decreased overall survival. These data identify a role for tumor-derived complement proteins in promoting tumor growth, and they therefore have substantial clinical and therapeutic implications.

The expression of VE-cadherin in breast cancer cells modulates cell dynamics as a function of tumor differentiation and promotes tumor-endothelial cell interactions.

Science.gov (United States)

Rezaei, Maryam; Cao, Jiahui; Friedrich, Katrin; Kemper, Björn; Brendel, Oliver; Grosser, Marianne; Adrian, Manuela; Baretton, Gustavo; Breier, Georg; Schnittler, Hans-Joachim

2018-01-01

The cadherin switch has profound consequences on cancer invasion and metastasis. The endothelial-specific vascular endothelial cadherin (VE-cadherin) has been demonstrated in diverse cancer types including breast cancer and is supposed to modulate tumor progression and metastasis, but underlying mechanisms need to be better understood. First, we evaluated VE-cadherin expression by tissue microarray in 392 cases of breast cancer tumors and found a diverse expression and distribution of VE-cadherin. Experimental expression of fluorescence-tagged VE-cadherin (VE-EGFP) in undifferentiated, fibroblastoid and E-cadherin-negative MDA-231 (MDA-VE-EGFP) as well as in differentiated E-cadherin-positive MCF-7 human breast cancer cell lines (MCF-VE-EGFP), respectively, displayed differentiation-dependent functional differences. VE-EGFP expression reversed the fibroblastoid MDA-231 cells to an epithelial-like phenotype accompanied by increased β-catenin expression, actin and vimentin remodeling, increased cell spreading and barrier function and a reduced migration ability due to formation of VE-cadherin-mediated cell junctions. The effects were largely absent in both MDA-VE-EGFP and in control MCF-EGFP cell lines. However, MCF-7 cells displayed a VE-cadherin-independent planar cell polarity and directed cell migration that both developed in MDA-231 only after VE-EGFP expression. Furthermore, VE-cadherin expression had no effect on tumor cell proliferation in monocultures while co-culturing with endothelial cells enhanced tumor cell proliferation due to integration of the tumor cells into monolayer where they form VE-cadherin-mediated cell contacts with the endothelium. We propose an interactive VE-cadherin-based crosstalk that might activate proliferation-promoting signals. Together, our study shows a VE-cadherin-mediated cell dynamics and an endothelial-dependent proliferation in a differentiation-dependent manner.

RASSF1A promoter is highly methylated in primitive neuroectodermal tumors of the central nervous system.

Science.gov (United States)

Inda, María-del-Mar; Castresana, Javier S

2007-08-01

Although cancer is rare in children, primary brain tumors constitute the most frequent location of solid tumors in childhood. Primitive neuroectodermal tumors (PNET) of the central nervous system can be divided into infratentorial PNET or medulloblastoma (MB), and supratentorial (sPNET) tumors. Although MB and sPNET are histologically similar, clinical evolution differs, sPNET being more aggressive than MB. Some studies have suggested that MB and sPNET present different molecular genetic aberrations. The RASSF1A (Ras Association Domain Family Protein 1) gene, located at 3p21.3, is highly methylated in multiple primary tumor samples, including neuroblastoma. In order to define whether there are genetic differences in the methylation frequency of RASSF1A between MB and sPNET, we analyzed 32 PNET paraffin-embedded samples (23 MB and 9 sPNET) by methylation specific polymerase chain reaction (MSP). We also analyzed RASSF1A expression by reverse transcription polymerase chain reaction in five PNET cell lines. All PNET cell lines showed lack of RASSF1A expression that was correlated with RASSF1A promoter hypermethylation. RASSF1A methylation was detected in 19 of 21 MB cases (91%) and in five of six sPNET samples (83%). Although the methylation frequency found in MB was slightly higher than in sPNET, no statistical differences were found for the RASSF1A hypermethylation frequency (P > 0.05) presented at MB versus sPNET. Therefore, the inactivation of the RASSF1A gene seems to be an important step in the tumorigenesis of PNET of the central nervous sytem. More studies should be performed in order to determine genetic differences between MB and sPNET.

Induction of CD3 delta epsilon omega by phorbol 12-myristate 13-acetate

DEFF Research Database (Denmark)

Vangsted, A; Neisig, A; Wallin, H

1993-01-01

The effect of phorbol 12-myristate 13-acetate (PMA) on the synthesis, assembly and processing of the components of the T cell receptor (TcR) was studied with special focus on the CD3 omega chain. Treatment of the human leukemic T cell line Jurkat with PMA increased the synthesis of the Ti alpha, CD......3 gamma and CG3 zeta chains two- to threefold and the synthesis of Ti beta and CD3 delta epsilon omega complexes five- to sevenfold as assessed by metabolic labeling, immunoprecipitation and sodium dodecyl sulfate-polyacrylamide gel electrophoresis followed by scanning densitometry. The amount...... of TcR complexes expressed on the cell surface was decreased after 16 h of PMA treatment. Based on these results we propose a role of CD3 omega in retention of TcR complexes. From PMA-treated CEM cells more than 50-fold the amount of CD3 delta epsilon omega complexes was immunoprecipitated as compared...

Tumor-Associated Macrophages Recruit CCR6+ Regulatory T Cells and Promote the Development of Colorectal Cancer via Enhancing CCL20 Production in Mice

Science.gov (United States)

Li, Qun; Zhang, Weiwei; Ke, Fang; Leng, Qibin; Wang, Hong; Chen, Jinfei; Wang, Honglin

2011-01-01

Background Tumor-associated macrophages (TAMs) remodel the colorectal cancer (CRC) microenvironment. Yet, findings on the role of TAMs in CRC seem to be contradictory compared with other cancers. FoxP3+ regulatory T (Treg)-cells dominantly infiltrate CRC. However, the underlying molecular mechanism in which TAMs may contribute to the trafficking of Treg-cells to the tumor mass remains unknown. Methodology/Principal Findings CRC was either induced by N-methyl-N-nitrosourea (MNU) and H. pylori or established by subcutaneous injection of mouse colorectal tumor cell line (CMT93) in mice. CMT93 cells were co-cultured with primary macrophages in a transwell apparatus. Recruitment of FoxP3 green fluorescence protein positive (FoxP3GFP+) Treg-cells was assessed using the IVIS Imaging System or immunofluorescence staining. A role for macrophages in trafficking of Treg-cells and in the development of CRC was investigated in CD11b diphtheria toxin receptor (CD11b-DTR) transgenic C57BL/6J mice in which macrophages can be selectively depleted. Treg-cells remarkably infiltrated solid tumor, and predominantly expressed the homing chemokine receptor (CCR) 6 in the induced CRC model. Both CMT93 cancer cells and macrophages produced a large amount of CCL20, the sole ligand of CCR6 in vitro and in vivo. Injection of recombinant mouse CCL20 into tumor sites promoted its development with a marked recruitment of Treg-cells in the graft CRC model. Conditional macrophage ablation decreased CCL20 levels, blocked Treg-cell recruitment and inhibited tumor growth in CD11b-DTR mice grafted with CMT93. Conclusions/Significance TAMs recruit CCR6+ Treg-cells to tumor mass and promote its development via enhancing the production of CCL20 in a CRC mouse model. PMID:21559338

Cancer-promoting tumor-associated macrophages: new vistas and open questions.

Science.gov (United States)

Mantovani, Alberto; Germano, Giovanni; Marchesi, Federica; Locatelli, Marco; Biswas, Subhra K

2011-09-01

Tumor-associated macrophages (TAMs) are key components of the tumor macroenvironment. Cancer- and host cell-derived signals generally drive the functions of TAMs towards an M2-like polarized, tumor-propelling mode; however, when appropriately re-educated. TAMs also have the potential to elicit tumor destructive reactions. Here, we discuss recent advances regarding the immunobiology of TAMs and highlight open questions including the mechanisms of their accumulation (recruitment versus proliferation), their diversity and how to best therapeutically target these cells. Copyright © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Cyclin-dependent kinase inhibitor 3 is overexpressed in hepatocellular carcinoma and promotes tumor cell proliferation

International Nuclear Information System (INIS)

Xing, Chunyang; Xie, Haiyang; Zhou, Lin; Zhou, Wuhua; Zhang, Wu; Ding, Songming; Wei, Bajin; Yu, Xiaobo; Su, Rong; Zheng, Shusen

2012-01-01

Highlights: ► CDKN3 is commonly overexpressed in HCC and is associated with poor clinical outcome. ► Overexpression of CDKN3 could stimulate the proliferation of HCC cells by promoting G1/S transition. ► CDKN3 could inhibit the expression of p21 in HCC cells. ► Overexpression of CDKN3 has no effect on apoptosis and invasion of HCC cells. ► We identified 61 genes co-expressed with CDKN3, and BIRC5 was located at the center of the co-expression network. -- Abstract: Cyclin-dependent kinase inhibitor 3 (CDKN3) belongs to the protein phosphatases family and has a dual function in cell cycling. The function of this gene has been studied in several kinds of cancers, but its role in human hepatocellular carcinoma (HCC) remains to be elucidated. In this study, we found that CDKN3 was frequently overexpressed in both HCC cell lines and clinical samples, and this overexpression was correlated with poor tumor differentiation and advanced tumor stage. Functional studies showed that overexpression of CDKN3 could promote cell proliferation by stimulating G1-S transition but has no impact on cell apoptosis and invasion. Microarray-based co-expression analysis identified a total of 61 genes co-expressed with CDKN3, with most of them involved in cell proliferation, and BIRC5 was located at the center of CDKN3 co-expression network. These results suggest that CDKN3 acts as an oncogene in human hepatocellular carcinoma and antagonism of CDKN3 may be of interest for the treatment of HCC.

Disruptive cell cycle regulation involving epigenetic downregulation of Cdkn2a (p16Ink4a) in early-stage liver tumor-promotion facilitating liver cell regeneration in rats

International Nuclear Information System (INIS)

Tsuchiya, Takuma; Wang, Liyun; Yafune, Atsunori; Kimura, Masayuki; Ohishi, Takumi; Suzuki, Kazuhiko; Mitsumori, Kunitoshi; Shibutani, Makoto

2012-01-01

Cell cycle aberration was immunohistochemically examined in relation to preneoplastic liver cell foci expressing glutathione S-transferase placental form (GST-P) at early stages of tumor-promotion in rats with thioacetamide (TAA), a hepatocarcinogen facilitating liver cell regeneration. Immunoexpression of p16 Ink4a following exposure to other hepatocarcinogens/promoters and its DNA methylation status were also analyzed during early and late tumor-promotion stages. GST-P + liver cell foci increased cell proliferation and decreased apoptosis when compared with surrounding liver cells. In concordance with GST-P + foci, checkpoint proteins at G 1 /S (p21 Cip1 , p27 Kip1 and p16 Ink4a ) and G 2 /M (phospho-checkpoint kinase 1, Cdc25c and phospho-Wee1) were either up- or downregulated. Cellular distribution within GST-P + foci was either increased or decreased with proteins related to G 2 -M phase or DNA damage (topoisomerase IIα, phospho-histone H2AX, phospho-histone H3 and Cdc2). In particular, p16 Ink4a typically downregulated in GST-P + foci and regenerative nodules at early tumor-promotion stage with hepatocarcinogens facilitating liver cell regeneration and in neoplastic lesions at late tumor-promotion stage with hepatocarcinogens/promoters irrespective of regenerating potential. Hypermethylation at exon 2 of Cdkn2a was detected at both early- and late-stages. Thus, diverse disruptive expression of G 1 /S and G 2 /M proteins, which allows for clonal selection of GST-P + foci, results in the acquisition of multiple aberrant phenotypes to disrupt checkpoint function. Moreover, increased DNA-damage responses within GST-P + foci may be the signature of genetic alterations. Intraexonic hypermethylation may be responsible for p16 Ink4a -downregulation, which facilitates cell cycle progression in early preneoplastic lesions produced by repeated cell regeneration and late-stage neoplastic lesions irrespective of the carcinogenic mechanism.

The Role of Neutrophil Myeloperoxidase in Models of Lung Tumor Development

International Nuclear Information System (INIS)

Rymaszewski, Amy L.; Tate, Everett; Yimbesalu, Joannes P.; Gelman, Andrew E.; Jarzembowski, Jason A.; Zhang, Hao; Pritchard, Kirkwood A. Jr.; Vikis, Haris G.

2014-01-01

Chronic inflammation plays a key tumor-promoting role in lung cancer. Our previous studies in mice demonstrated that neutrophils are critical mediators of tumor promotion in methylcholanthrene (MCA)-initiated, butylated hydroxytoluene (BHT)-promoted lung carcinogenesis. In the present study we investigated the role of neutrophil myeloperoxidase (MPO) activity in this inflammation promoted model. Increased levels of MPO protein and activity were present in the lungs of mice administered BHT. Treatment of mice with N-acetyl lysyltyrosylcysteine amide (KYC), a novel tripeptide inhibitor of MPO, during the inflammatory stage reduced tumor burden. In a separate tumor model, KYC treatment of a Lewis Lung Carcinoma (LLC) tumor graft in mice had no effect on tumor growth, however, mice genetically deficient in MPO had significantly reduced LLC tumor growth. Our observations suggest that MPO catalytic activity is critical during the early stages of tumor development. However, during the later stages of tumor progression, MPO expression independent of catalytic activity appears to be required. Our studies advocate for the use of MPO inhibitors in a lung cancer prevention setting

The role of neutrophil myeloperoxidase in models of lung tumor development.

Science.gov (United States)

Rymaszewski, Amy L; Tate, Everett; Yimbesalu, Joannes P; Gelman, Andrew E; Jarzembowski, Jason A; Zhang, Hao; Pritchard, Kirkwood A; Vikis, Haris G

2014-05-09

Chronic inflammation plays a key tumor-promoting role in lung cancer. Our previous studies in mice demonstrated that neutrophils are critical mediators of tumor promotion in methylcholanthrene (MCA)-initiated, butylated hydroxytoluene (BHT)-promoted lung carcinogenesis. In the present study we investigated the role of neutrophil myeloperoxidase (MPO) activity in this inflammation promoted model. Increased levels of MPO protein and activity were present in the lungs of mice administered BHT. Treatment of mice with N-acetyl lysyltyrosylcysteine amide (KYC), a novel tripeptide inhibitor of MPO, during the inflammatory stage reduced tumor burden. In a separate tumor model, KYC treatment of a Lewis Lung Carcinoma (LLC) tumor graft in mice had no effect on tumor growth, however, mice genetically deficient in MPO had significantly reduced LLC tumor growth. Our observations suggest that MPO catalytic activity is critical during the early stages of tumor development. However, during the later stages of tumor progression, MPO expression independent of catalytic activity appears to be required. Our studies advocate for the use of MPO inhibitors in a lung cancer prevention setting.

The Role of Neutrophil Myeloperoxidase in Models of Lung Tumor Development

Energy Technology Data Exchange (ETDEWEB)

Rymaszewski, Amy L.; Tate, Everett; Yimbesalu, Joannes P. [Department of Pharmacology and Toxicology and MCW Cancer Center, Medical College of Wisconsin, Milwaukee, WI 53226 (United States); Gelman, Andrew E. [Department of Surgery, Washington University in St. Louis, St. Louis, MO 63130 (United States); Jarzembowski, Jason A. [Department of Pathology, Medical College of Wisconsin, Milwaukee, WI 53226 (United States); Zhang, Hao; Pritchard, Kirkwood A. Jr. [Department of Surgery and MCW Cancer Center, Medical College of Wisconsin, Milwaukee, WI 53226 (United States); Vikis, Haris G., E-mail: hvikis@mcw.edu [Department of Pharmacology and Toxicology and MCW Cancer Center, Medical College of Wisconsin, Milwaukee, WI 53226 (United States)

2014-05-09

Chronic inflammation plays a key tumor-promoting role in lung cancer. Our previous studies in mice demonstrated that neutrophils are critical mediators of tumor promotion in methylcholanthrene (MCA)-initiated, butylated hydroxytoluene (BHT)-promoted lung carcinogenesis. In the present study we investigated the role of neutrophil myeloperoxidase (MPO) activity in this inflammation promoted model. Increased levels of MPO protein and activity were present in the lungs of mice administered BHT. Treatment of mice with N-acetyl lysyltyrosylcysteine amide (KYC), a novel tripeptide inhibitor of MPO, during the inflammatory stage reduced tumor burden. In a separate tumor model, KYC treatment of a Lewis Lung Carcinoma (LLC) tumor graft in mice had no effect on tumor growth, however, mice genetically deficient in MPO had significantly reduced LLC tumor growth. Our observations suggest that MPO catalytic activity is critical during the early stages of tumor development. However, during the later stages of tumor progression, MPO expression independent of catalytic activity appears to be required. Our studies advocate for the use of MPO inhibitors in a lung cancer prevention setting.

The Role of Neutrophil Myeloperoxidase in Models of Lung Tumor Development

Directory of Open Access Journals (Sweden)

Amy L. Rymaszewski

2014-05-01

Full Text Available Chronic inflammation plays a key tumor-promoting role in lung cancer. Our previous studies in mice demonstrated that neutrophils are critical mediators of tumor promotion in methylcholanthrene (MCA-initiated, butylated hydroxytoluene (BHT-promoted lung carcinogenesis. In the present study we investigated the role of neutrophil myeloperoxidase (MPO activity in this inflammation promoted model. Increased levels of MPO protein and activity were present in the lungs of mice administered BHT. Treatment of mice with N-acetyl lysyltyrosylcysteine amide (KYC, a novel tripeptide inhibitor of MPO, during the inflammatory stage reduced tumor burden. In a separate tumor model, KYC treatment of a Lewis Lung Carcinoma (LLC tumor graft in mice had no effect on tumor growth, however, mice genetically deficient in MPO had significantly reduced LLC tumor growth. Our observations suggest that MPO catalytic activity is critical during the early stages of tumor development. However, during the later stages of tumor progression, MPO expression independent of catalytic activity appears to be required. Our studies advocate for the use of MPO inhibitors in a lung cancer prevention setting.

Deleted in Malignant Brain Tumors 1 is Present in the Vascular Extracellular Matrix and Promotes Angiogenesis

DEFF Research Database (Denmark)

Müller-Enbergs, Helmut; Hu, Jiong; Popp, Rüdiger

2012-01-01

OBJECTIVE: Deleted in malignant brain tumors 1 (DMBT1) belongs to the scavenger receptor cysteine-rich superfamily of proteins and is implicated in innate immunity, cell polarity, and differentiation. Here we studied the role of DMBT1 in endothelial cells. METHODS AND RESULTS: DMBT1 was secreted ...... and promote adhesion, migration, proliferation, and angiogenesis as well as vascular repair. Mechanistically, DMBT1 interacts with galectin-3 and modulates the Notch signaling pathway as well as the differential expression of ephrin-B2 and EphB4....

Epithelial membrane protein-2 promotes endometrial tumor formation through activation of FAK and Src.

Directory of Open Access Journals (Sweden)

Maoyong Fu

Full Text Available Endometrial cancer is the most common gynecologic malignancy diagnosed among women in developed countries. One recent biomarker strongly associated with disease progression and survival is epithelial membrane protein-2 (EMP2, a tetraspan protein known to associate with and modify surface expression of certain integrin isoforms. In this study, we show using a xenograft model system that EMP2 expression is necessary for efficient endometrial tumor formation, and we have started to characterize the mechanism by which EMP2 contributes to this malignant phenotype. In endometrial cancer cells, the focal adhesion kinase (FAK/Src pathway appears to regulate migration as measured through wound healing assays. Manipulation of EMP2 levels in endometrial cancer cells regulates the phosphorylation of FAK and Src, and promotes their distribution into lipid raft domains. Notably, cells with low levels of EMP2 fail to migrate and poorly form tumors in vivo. These findings reveal the pivotal role of EMP2 in endometrial cancer carcinogenesis, and suggest that the association of elevated EMP2 levels with endometrial cancer prognosis may be causally linked to its effect on integrin-mediated signaling.

ActivinB Is Induced in Insulinoma To Promote Tumor Plasticity through a β-Cell-Induced Dedifferentiation.

Science.gov (United States)

Ripoche, Doriane; Charbord, Jérémie; Hennino, Ana; Teinturier, Romain; Bonnavion, Rémy; Jaafar, Rami; Goehrig, Delphine; Cordier-Bussat, Martine; Ritvos, Olli; Zhang, Chang X; Andersson, Olov; Bertolino, Philippe

2015-12-28

Loss of pancreatic β-cell maturity occurs in diabetes and insulinomas. Although both physiological and pathological stresses are known to promote β-cell dedifferentiation, little is known about the molecules involved in this process. Here we demonstrate that activinB, a transforming growth factor β (TGF-β)-related ligand, is upregulated during tumorigenesis and drives the loss of insulin expression and β-cell maturity in a mouse insulinoma model. Our data further identify Pax4 as a previously unknown activinB target and potent contributor to the observed β-cell dedifferentiation. More importantly, using compound mutant mice, we found that deleting activinB expression abolishes tumor β-cell dedifferentiation and, surprisingly, increases survival without significantly affecting tumor growth. Hence, this work reveals an unexpected role for activinB in the loss of β-cell maturity, islet plasticity, and progression of insulinoma through its participation in β-cell dedifferentiation. Copyright © 2016, American Society for Microbiology. All Rights Reserved.

Detoxification of Jatropha curcas kernel cake by a novel Streptomyces fimicarius strain.

Science.gov (United States)

Wang, Xing-Hong; Ou, Lingcheng; Fu, Liang-Liang; Zheng, Shui; Lou, Ji-Dong; Gomes-Laranjo, José; Li, Jiao; Zhang, Changhe

2013-09-15

A huge amount of kernel cake, which contains a variety of toxins including phorbol esters (tumor promoters), is projected to be generated yearly in the near future by the Jatropha biodiesel industry. We showed that the kernel cake strongly inhibited plant seed germination and root growth and was highly toxic to carp fingerlings, even though phorbol esters were undetectable by HPLC. Therefore it must be detoxified before disposal to the environment. A mathematic model was established to estimate the general toxicity of the kernel cake by determining the survival time of carp fingerling. A new strain (Streptomyces fimicarius YUCM 310038) capable of degrading the total toxicity by more than 97% in a 9-day solid state fermentation was screened out from 578 strains including 198 known strains and 380 strains isolated from air and soil. The kernel cake fermented by YUCM 310038 was nontoxic to plants and carp fingerlings and significantly promoted tobacco plant growth, indicating its potential to transform the toxic kernel cake to bio-safe animal feed or organic fertilizer to remove the environmental concern and to reduce the cost of the Jatropha biodiesel industry. Microbial strain profile essential for the kernel cake detoxification was discussed. Copyright © 2013 Elsevier B.V. All rights reserved.

The tumor promoter 12-O-tetradecanoylphorbol-13-acetate (TPA) accelerates expression of differentiation markers in cultures of rat palatal epithelial cells

DEFF Research Database (Denmark)

Arenholt, D; Dabelsteen, Erik

1987-01-01

Cultures of rat palatal epithelium grown on collagen rafts were treated with different doses of the potent tumor promoter 12-O-tetradecanoylphorbol-13-acetate (TPA). Sections from biopsies taken 1, 6, 24, and 48 hr after the addition of TPA were examined for the localization of staining by blood ...

ESR1 gene promoter region methylation in free circulating DNA and its correlation with estrogen receptor protein expression in tumor tissue in breast cancer patients

International Nuclear Information System (INIS)

Martínez-Galán, Joaquina; Ríos, Sandra; Delgado, Juan Ramón; Torres-Torres, Blanca; Núñez, María Isabel; López-Peñalver, Jesús; Del Moral, Rosario; Ruiz De Almodóvar, José Mariano; Menjón, Salomón; Concha, Ángel; Chamorro, Clara

2014-01-01

Tumor expression of estrogen receptor (ER) is an important marker of prognosis, and is predictive of response to endocrine therapy in breast cancer. Several studies have observed that epigenetic events, such methylation of cytosines and deacetylation of histones, are involved in the complex mechanisms that regulate promoter transcription. However, the exact interplay of these factors in transcription activity is not well understood. In this study, we explored the relationship between ER expression status in tumor tissue samples and the methylation of the 5′ CpG promoter region of the estrogen receptor gene (ESR1) isolated from free circulating DNA (fcDNA) in plasma samples from breast cancer patients. Patients (n = 110) with non-metastatic breast cancer had analyses performed of ER expression (luminal phenotype in tumor tissue, by immunohistochemistry method), and the ESR1-DNA methylation status (fcDNA in plasma, by quantitative methylation specific PCR technique). Our results showed a significant association between presence of methylated ESR1 in patients with breast cancer and ER negative status in the tumor tissue (p = 0.0179). There was a trend towards a higher probability of ESR1-methylation in those phenotypes with poor prognosis i.e. 80% of triple negative patients, 60% of HER2 patients, compared to 28% and 5.9% of patients with better prognosis such as luminal A and luminal B, respectively. Silencing, by methylation, of the promoter region of the ESR1 affects the expression of the estrogen receptor protein in tumors of breast cancer patients; high methylation of ESR1-DNA is associated with estrogen receptor negative status which, in turn, may be implicated in the patient’s resistance to hormonal treatment in breast cancer. As such, epigenetic markers in plasma may be of interest as new targets for anticancer therapy, especially with respect to endocrine treatment

The Yin and Yang of Invariant Natural Killer T Cells in Tumor Immunity—Suppression of Tumor Immunity in the Intestine

Directory of Open Access Journals (Sweden)

Ying Wang

2018-01-01

Full Text Available CD1d-restricted invariant natural killer T (iNKT cells are known as early responding, potent regulatory cells of immune responses. Besides their established role in the regulation of inflammation and autoimmune disease, numerous studies have shown that iNKT cells have important functions in tumor immunosurveillance and control of tumor metastasis. Tumor-infiltrating T helper 1 (TH1/cytotoxic T lymphocytes have been associated with a positive prognosis. However, inflammation has a dual role in cancer and chronic inflammation is believed to be a driving force in many cancers as exemplified in patients with inflammatory bowel disease that have an increased risk of colorectal cancer. Indeed, NKT cells promote intestinal inflammation in human ulcerative colitis, and the associated animal model, indicating that NKT cells may favor tumor development in intestinal tissue. In contrast to other cancers, recent data from animal models suggest that iNKT cells promote tumor formation in the intestine by supporting an immunoregulatory tumor microenvironment and suppressing TH1 antitumor immunity. Here, we review the role of iNKT cells in suppression of tumor immunity in light of iNKT-cell regulation of intestinal inflammation. We also discuss suppression of immunity in other situations as well as factors that may influence whether iNKT cells have a protective or an immunosuppressive and tumor-promoting role in tumor immunity.

Tumor Necrosis Factor-Mediated Survival of CD169+ Cells Promotes Immune Activation during Vesicular Stomatitis Virus Infection

DEFF Research Database (Denmark)

Shinde, Prashant V; Xu, Haifeng C; Maney, Sathish Kumar

2018-01-01

Innate immune activation is essential to mount an effective antiviral response and to prime adaptive immunity. Although a crucial role of CD169(+) cells during vesicular stomatitis virus (VSV) infections is increasingly recognized, factors regulating CD169(+) cells during viral infections remain...... stomatitis virus infection, phagocytes produce tumor necrosis factor (TNF) which signals via TNFR1 and promote "enforced virus replication" in CD169(+) macrophages. Consequently, lack of TNF or TNFR1 resulted in defective immune activation and VSV clearance....

Tumor Cells and Tumor-Associated Macrophages: Secreted Proteins as Potential Targets for Therapy

Science.gov (United States)

Baay, Marc; Brouwer, Anja; Pauwels, Patrick; Peeters, Marc; Lardon, Filip

2011-01-01

Inflammatory pathways, meant to defend the organism against infection and injury, as a byproduct, can promote an environment which favors tumor growth and metastasis. Tumor-associated macrophages (TAMs), which constitute a significant part of the tumor-infiltrating immune cells, have been linked to the growth, angiogenesis, and metastasis of a variety of cancers, most likely through polarization of TAMs to the M2 (alternative) phenotype. The interaction between tumor cells and macrophages provides opportunities for therapy. This paper will discuss secreted proteins as targets for intervention. PMID:22162712

Tumor Cells and Tumor-Associated Macrophages: Secreted Proteins as Potential Targets for Therapy

Directory of Open Access Journals (Sweden)

Marc Baay

2011-01-01

Full Text Available Inflammatory pathways, meant to defend the organism against infection and injury, as a byproduct, can promote an environment which favors tumor growth and metastasis. Tumor-associated macrophages (TAMs, which constitute a significant part of the tumor-infiltrating immune cells, have been linked to the growth, angiogenesis, and metastasis of a variety of cancers, most likely through polarization of TAMs to the M2 (alternative phenotype. The interaction between tumor cells and macrophages provides opportunities for therapy. This paper will discuss secreted proteins as targets for intervention.

Tumor-Associated Macrophages as Major Players in the Tumor Microenvironment

International Nuclear Information System (INIS)

Chanmee, Theerawut; Ontong, Pawared; Konno, Kenjiro; Itano, Naoki

2014-01-01

During tumor progression, circulating monocytes and macrophages are actively recruited into tumors where they alter the tumor microenvironment to accelerate tumor progression. Macrophages shift their functional phenotypes in response to various microenvironmental signals generated from tumor and stromal cells. Based on their function, macrophages are divided broadly into two categories: classical M1 and alternative M2 macrophages. The M1 macrophage is involved in the inflammatory response, pathogen clearance, and antitumor immunity. In contrast, the M2 macrophage influences an anti-inflammatory response, wound healing, and pro-tumorigenic properties. Tumor-associated macrophages (TAMs) closely resemble the M2-polarized macrophages and are critical modulators of the tumor microenvironment. Clinicopathological studies have suggested that TAM accumulation in tumors correlates with a poor clinical outcome. Consistent with that evidence, experimental and animal studies have supported the notion that TAMs can provide a favorable microenvironment to promote tumor development and progression. In this review article, we present an overview of mechanisms responsible for TAM recruitment and highlight the roles of TAMs in the regulation of tumor angiogenesis, invasion, metastasis, immunosuppression, and chemotherapeutic resistance. Finally, we discuss TAM-targeting therapy as a promising novel strategy for an indirect cancer therapy

Tumor-Associated Macrophages as Major Players in the Tumor Microenvironment

Energy Technology Data Exchange (ETDEWEB)

Chanmee, Theerawut [Institute of Advanced Technology, Kyoto Sangyo University, Kita-ku, Kyoto 603-8555 (Japan); Ontong, Pawared [Division of Engineering (Biotechnology), Graduate School of Engineering, Kyoto Sangyo University, Kita-ku, Kyoto 603-8555 (Japan); Konno, Kenjiro [Department of Animal Medical Sciences, Faculty of Life Sciences, Kyoto Sangyo University, Kita-ku, Kyoto 603-8555 (Japan); Itano, Naoki, E-mail: itanon@cc.kyoto-su.ac.jp [Institute of Advanced Technology, Kyoto Sangyo University, Kita-ku, Kyoto 603-8555 (Japan); Division of Engineering (Biotechnology), Graduate School of Engineering, Kyoto Sangyo University, Kita-ku, Kyoto 603-8555 (Japan); Department of Molecular Biosciences, Faculty of Life Sciences, Kyoto Sangyo University, Kita-ku, Kyoto 603-8555 (Japan)

2014-08-13

During tumor progression, circulating monocytes and macrophages are actively recruited into tumors where they alter the tumor microenvironment to accelerate tumor progression. Macrophages shift their functional phenotypes in response to various microenvironmental signals generated from tumor and stromal cells. Based on their function, macrophages are divided broadly into two categories: classical M1 and alternative M2 macrophages. The M1 macrophage is involved in the inflammatory response, pathogen clearance, and antitumor immunity. In contrast, the M2 macrophage influences an anti-inflammatory response, wound healing, and pro-tumorigenic properties. Tumor-associated macrophages (TAMs) closely resemble the M2-polarized macrophages and are critical modulators of the tumor microenvironment. Clinicopathological studies have suggested that TAM accumulation in tumors correlates with a poor clinical outcome. Consistent with that evidence, experimental and animal studies have supported the notion that TAMs can provide a favorable microenvironment to promote tumor development and progression. In this review article, we present an overview of mechanisms responsible for TAM recruitment and highlight the roles of TAMs in the regulation of tumor angiogenesis, invasion, metastasis, immunosuppression, and chemotherapeutic resistance. Finally, we discuss TAM-targeting therapy as a promising novel strategy for an indirect cancer therapy.

Irradiation promotes Akt-targeting therapeutic gene delivery to the tumor vasculature

International Nuclear Information System (INIS)

Sonveaux, Pierre; Frerart, Francoise; Bouzin, Caroline; Brouet, Agnes; Wever, Julie de; Jordan, Benedicte F.; Gallez, Bernard; Feron, Olivier

2007-01-01

Purpose: To determine whether radiation-induced increases in nitric oxide (NO) production can influence tumor blood flow and improve delivery of Akt-targeting therapeutic DNA lipocomplexes to the tumor. Methods and Materials: The contribution of NO to the endothelial response to radiation was identified using NO synthase (NOS) inhibitors and endothelial NOS (eNOS)-deficient mice. Reporter-encoding plasmids complexed with cationic lipids were used to document the tumor vascular specificity and the efficacy of in vivo lipofection after irradiation. A dominant-negative Akt gene construct was used to evaluate the facilitating effects of radiotherapy on the therapeutic transgene delivery. Results: The abundance of eNOS protein was increased in both irradiated tumor microvessels and endothelial cells, leading to a stimulation of NO release and an associated increase in tumor blood flow. Transgene expression was subsequently improved in the irradiated vs. nonirradiated tumor vasculature. This effect was not apparent in eNOS-deficient mice and could not be reproduced in irradiated cultured endothelial cells. Finally, we combined low-dose radiotherapy with a dominant-negative Akt gene construct and documented synergistic antitumor effects. Conclusions: This study offers a new rationale to combine radiotherapy with gene therapy, by directly exploiting the stimulatory effects of radiation on NO production by tumor endothelial cells. The preferential expression of the transgene in the tumor microvasculature underscores the potential of such an adjuvant strategy to limit the angiogenic response of irradiated tumors

Designing a HER2/neu promoter to drive α1,3galactosyltransferase expression for targeted anti-αGal antibody-mediated tumor cell killing

International Nuclear Information System (INIS)

Lanteri, Marion; Ollier, Laurence; Giordanengo, Valérie; Lefebvre, Jean-Claude

2005-01-01

Our goal was to specifically render tumor cells susceptible to natural cytolytic anti-αGal antibodies by using a murine α1,3galactosyltransferase (mαGalT) transgene driven by a designed form of HER2/neu promoter (pNeu), the transcription of which is frequently observed to be above basal in breast tumors. Indeed, the αGalT activity that promotes Galα1,3Galβ1,4GlcNAc-R (αGal) epitope expression has been mutationally disrupted during the course of evolution, starting from Old World primates, and this has led to the counter-production of large amounts of cytotoxic anti-αGal antibodies in recent primates, including man. Expression of the endogenous c-erbB-2 gene was investigated in various cell lines by northern blotting. A mαGalT cDNA was constructed into pcDNA3 vector downstream of the original CMV promoter (pCMV/mαGalT) and various forms of pNeu were prepared by PCR amplification and inserted in the pCMV/mαGalT construct upstream of the mαGalT cDNA, in the place of the CMV promoter. These constructs were transferred into HEK-293 control and breast tumor cell lines. Stably transfected cells were analyzed by northern blotting for their expression of αGalT and c-erbB-2, and by flow cytometry for their binding with fluorescein isothiocyanate-conjugated Griffonia simplicifolia/isolectin B4. We show that expression of the mαGalT was up- or down-modulated according to the level of endogenous pNeu activity and the particular form of constructed pNeu. Among several constructs, two particular forms of the promoter, pNeu250 containing the CCAAT box and the PEA3 motif adjacent to the TATAA box, and pNeu664, which has three additional PEA3 motifs upstream of the CCAAT box, were found to promote differential αGalT expression. Our results strengthen current concepts about the crucial role played by the proximal PEA3 motif of pNeu, and may represent a novel therapeutic approach for the development of targeted transgene expression

The Role of Tumor Associated Macrophage in Recurrent Growth of Tumor Stem Cell

Science.gov (United States)

2011-09-01

recent cancer stem cell (CSC) theory, recurrent tumor must arise from a dormant tumor stem cell whose re-growth is triggered by shifting of...microenvironment. This project aims at clarifying the roles of TAM in recurrent growth of dormant stem cell in breast cancer. We hypothesize that the balance of...dormancy and recurrence is determined by the ability of the tumor stem cells to recruit TAM which in turn promotes self-renewal of the stem cell . We

Translationally controlled tumor protein supplemented chitosan modified glass ionomer cement promotes osteoblast proliferation and function

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Sangsuwan, Jiraporn [Department of Molecular Biology and Bioinformatics, Center for Genomics and Bioinformatics Research, Faculty of Science, Prince of Songkla University, Hat Yai, Songkhla 90112 (Thailand); Department of Oral Biology and Occlusion, Faculty of Dentistry, Prince of Songkla University, Hat Yai, Songkhla 90112 (Thailand); Wanichpakorn, Supreya; Kedjarune-Leggat, Ureporn [Department of Oral Biology and Occlusion, Faculty of Dentistry, Prince of Songkla University, Hat Yai, Songkhla 90112 (Thailand)

2015-09-01

The objective of this study was to evaluate the effect of translationally controlled tumor protein (TCTP) supplemented in a novel glass ionomer cement (BIO-GIC) on normal human osteoblasts (NHost cells). BIO-GIC was a glass ionomer cement (GIC) modified by adding chitosan and albumin to promote the release of TCTP. NHost cells were seeded on specimens of GIC, GIC + TCTP, BIO-GIC and BIO-GIC + TCTP. Cell proliferation was determined by BrdU assay. It was found that BIO-GIC + TCTP had significantly higher proliferation of cells than other specimens. Bone morphogenetic protein-2 (BMP-2) and osteopontin (OPN) gene expressions assessed by quantitative real time PCR and alkaline phosphatase (ALP) activity were used to determine cell differentiation. Bone cell function was investigated by calcium deposition using alizarin assay. Both BMP-2 and OPN gene expressions of cells cultured on specimens with added TCTP increased gradually up-regulation after day 1 and reached the highest on day 3 then down-regulation on day 7. The ALP activity of cells cultured on BIO-GIC + TCTP for 7 days and calcium content after 14 days were significantly higher than other groups. BIO-GIC + TCTP can promote osteoblast cells proliferation, differentiation and function. - Highlights: • Developed a new GIC by supplementing TCTP in BIO-GIC (GIC with chitosan and albumin) • BIO-GIC + TCTP released a higher amount of TCTP than GIC + TCTP. • BIO-GIC + TCTP promoted cell proliferation higher than other specimens and control. • BIO-GIC + TCTP promoted osteoblasts differentiation and function.

Translationally controlled tumor protein supplemented chitosan modified glass ionomer cement promotes osteoblast proliferation and function

International Nuclear Information System (INIS)

Sangsuwan, Jiraporn; Wanichpakorn, Supreya; Kedjarune-Leggat, Ureporn

2015-01-01

The objective of this study was to evaluate the effect of translationally controlled tumor protein (TCTP) supplemented in a novel glass ionomer cement (BIO-GIC) on normal human osteoblasts (NHost cells). BIO-GIC was a glass ionomer cement (GIC) modified by adding chitosan and albumin to promote the release of TCTP. NHost cells were seeded on specimens of GIC, GIC + TCTP, BIO-GIC and BIO-GIC + TCTP. Cell proliferation was determined by BrdU assay. It was found that BIO-GIC + TCTP had significantly higher proliferation of cells than other specimens. Bone morphogenetic protein-2 (BMP-2) and osteopontin (OPN) gene expressions assessed by quantitative real time PCR and alkaline phosphatase (ALP) activity were used to determine cell differentiation. Bone cell function was investigated by calcium deposition using alizarin assay. Both BMP-2 and OPN gene expressions of cells cultured on specimens with added TCTP increased gradually up-regulation after day 1 and reached the highest on day 3 then down-regulation on day 7. The ALP activity of cells cultured on BIO-GIC + TCTP for 7 days and calcium content after 14 days were significantly higher than other groups. BIO-GIC + TCTP can promote osteoblast cells proliferation, differentiation and function. - Highlights: • Developed a new GIC by supplementing TCTP in BIO-GIC (GIC with chitosan and albumin) • BIO-GIC + TCTP released a higher amount of TCTP than GIC + TCTP. • BIO-GIC + TCTP promoted cell proliferation higher than other specimens and control. • BIO-GIC + TCTP promoted osteoblasts differentiation and function

Interleukin‑6 induces an epithelial‑mesenchymal transition phenotype in human adamantinomatous craniopharyngioma cells and promotes tumor cell migration.

Science.gov (United States)

Zhou, Jie; Zhang, Chao; Pan, Jun; Chen, Ligang; Qi, Song-Tao

2017-06-01

Total resection of adamantinomatous craniopharyngioma (ACP) is complex and often leads to postoperative recurrence. This is due to the tendency of the tumor to invade the surrounding brain tissue and the generation of a local inflammatory state between the tumor cells and parenchyma. While there is evidence to suggest that interleukin‑6 (IL‑6) induces craniopharyngioma (CP)‑associated inflammation, particularly in ACP, the role of IL‑6 in the progression of ACP remains unclear. The results of the present study demonstrated that CP inflammation was associated with pathological classification, extent of surgery, degree of calcification and postoperative hypothalamic status scale. Cytokine antibody arrays were conducted to measure the expression of IL‑6 and other inflammatory factors in tumor tissues in response to various levels of inflammatory exposure. IL‑6, IL‑6 receptor (IL‑6R) and glycoprotein 130 expression was detected by immunohistochemistry. In addition, an ELISA was performed to quantify the levels of soluble IL‑6R (sIL‑6R) in the cystic fluid and supernatants of ACP cells and tumor‑associated fibroblasts. These measurements demonstrated that ACP cells produce IL‑6 and its associated proteins. In addition, the results revealed that while the viability of ACP cells was not affected, the migration of ACP cells was promoted by IL‑6 treatment in a concentration‑dependent manner. Conversely, treatment with an IL‑6‑blocking monoclonal antibody significantly decreased the migration of ACP cells. In addition, IL‑6 treatment increased the expression of vimentin and decreased the expression of E‑cadherin in a dose‑dependent manner. The findings of the present study demonstrate that IL‑6 may promote migration in vitro via the classic‑ and trans‑signaling pathways by inducing epithelial‑mesenchymal transition in ACP cell cultures.

Constitutive Signaling from an Engineered IL7 Receptor Promotes Durable Tumor Elimination by Tumor-Redirected T Cells.

Science.gov (United States)

Shum, Thomas; Omer, Bilal; Tashiro, Haruko; Kruse, Robert L; Wagner, Dimitrios L; Parikh, Kathan; Yi, Zhongzhen; Sauer, Tim; Liu, Daofeng; Parihar, Robin; Castillo, Paul; Liu, Hao; Brenner, Malcolm K; Metelitsa, Leonid S; Gottschalk, Stephen; Rooney, Cliona M

2017-11-01

Successful adoptive T-cell immunotherapy of solid tumors will require improved expansion and cytotoxicity of tumor-directed T cells within tumors. Providing recombinant or transgenic cytokines may produce the desired benefits but is associated with significant toxicities, constraining clinical use. To circumvent this limitation, we constructed a constitutively signaling cytokine receptor, C7R, which potently triggers the IL7 signaling axis but is unresponsive to extracellular cytokine. This strategy augments modified T-cell function following antigen exposure, but avoids stimulating bystander lymphocytes. Coexpressing the C7R with a tumor-directed chimeric antigen receptor (CAR) increased T-cell proliferation, survival, and antitumor activity during repeated exposure to tumor cells, without T-cell dysfunction or autonomous T-cell growth. Furthermore, C7R-coexpressing CAR T cells were active against metastatic neuroblastoma and orthotopic glioblastoma xenograft models even at cell doses that had been ineffective without C7R support. C7R may thus be able to enhance antigen-specific T-cell therapies against cancer. Significance: The constitutively signaling C7R system developed here delivers potent IL7 stimulation to CAR T cells, increasing their persistence and antitumor activity against multiple preclinical tumor models, supporting its clinical development. Cancer Discov; 7(11); 1238-47. ©2017 AACR. This article is highlighted in the In This Issue feature, p. 1201 . ©2017 American Association for Cancer Research.

Tumor-Derived Exosomes and Their Role in Tumor-Induced Immune Suppression

Directory of Open Access Journals (Sweden)

Theresa L. Whiteside

2016-10-01

Full Text Available Tumor-derived exosomes (TEX are emerging as critical components of an intercellular information network between the tumor and the host. The tumor escapes from the host immune system by using a variety of mechanisms designed to impair or eliminate anti-tumor immunity. TEX carrying a cargo of immunoinhibitory molecules and factors represent one such mechanism. TEX, which are present in all body fluids of cancer patients, deliver negative molecular or genetic signals to immune cells re-programming their functions. Although TEX can also stimulate immune activity, in the microenvironments dominated by the tumor, TEX tend to mediate immune suppression thus promoting tumor progression. The TEX content, in part resembling that of the parent cell, may serve as a source of cancer biomarkers. TEX also interfere with immune therapies. A better understanding of TEX and their contribution to cancer progression and cancer patients’ response to immune therapies represents a challenging new field of investigation.

TRIP-Br2 promotes oncogenesis in nude mice and is frequently overexpressed in multiple human tumors.

Science.gov (United States)

Cheong, Jit Kong; Gunaratnam, Lakshman; Zang, Zhi Jiang; Yang, Christopher M; Sun, Xiaoming; Nasr, Susan L; Sim, Khe Guan; Peh, Bee Keow; Rashid, Suhaimi Bin Abdul; Bonventre, Joseph V; Salto-Tellez, Manuel; Hsu, Stephen I

2009-01-20

Members of the TRIP-Br/SERTAD family of mammalian transcriptional coregulators have recently been implicated in E2F-mediated cell cycle progression and tumorigenesis. We, herein, focus on the detailed functional characterization of the least understood member of the TRIP-Br/SERTAD protein family, TRIP-Br2 (SERTAD2). Oncogenic potential of TRIP-Br2 was demonstrated by (1) inoculation of NIH3T3 fibroblasts, which were engineered to stably overexpress ectopic TRIP-Br2, into athymic nude mice for tumor induction and (2) comprehensive immunohistochemical high-throughput screening of TRIP-Br2 protein expression in multiple human tumor cell lines and human tumor tissue microarrays (TMAs). Clinicopathologic analysis was conducted to assess the potential of TRIP-Br2 as a novel prognostic marker of human cancer. RNA interference of TRIP-Br2 expression in HCT-116 colorectal carcinoma cells was performed to determine the potential of TRIP-Br2 as a novel chemotherapeutic drug target. Overexpression of TRIP-Br2 is sufficient to transform murine fibroblasts and promotes tumorigenesis in nude mice. The transformed phenotype is characterized by deregulation of the E2F/DP-transcriptional pathway through upregulation of the key E2F-responsive genes CYCLIN E, CYCLIN A2, CDC6 and DHFR. TRIP-Br2 is frequently overexpressed in both cancer cell lines and multiple human tumors. Clinicopathologic correlation indicates that overexpression of TRIP-Br2 in hepatocellular carcinoma is associated with a worse clinical outcome by Kaplan-Meier survival analysis. Small interfering RNA-mediated (siRNA) knockdown of TRIP-Br2 was sufficient to inhibit cell-autonomous growth of HCT-116 cells in vitro. This study identifies TRIP-Br2 as a bona-fide protooncogene and supports the potential for TRIP-Br2 as a novel prognostic marker and a chemotherapeutic drug target in human cancer.

Meta-analysis of promoter methylation in eight tumor-suppressor genes and its association with the risk of thyroid cancer.

Directory of Open Access Journals (Sweden)

Fatemeh Khatami

Full Text Available Promoter methylation in a number of tumor-suppressor genes (TSGs can play crucial roles in the development of thyroid carcinogenesis. The focus of the current meta-analysis was to determine the impact of promoter methylation of eight selected candidate TSGs on thyroid cancer and to identify the most important molecules in this carcinogenesis pathway. A comprehensive search was performed using Pub Med, Scopus, and ISI Web of Knowledge databases, and eligible studies were included. The methodological quality of the included studies was evaluated according to the Newcastle Ottawa scale table and pooled odds ratios (ORs; 95% confidence intervals (CIs were used to estimate the strength of the associations with Stata 12.0 software. Egger's and Begg's tests were applied to detect publication bias, in addition to the "Metatrim" method. A total of 55 articles were selected, and 135 genes with altered promoter methylation were found. Finally, we included eight TSGs that were found in more than four studies (RASSF1, TSHR, PTEN, SLC5A, DAPK, P16, RARβ2, and CDH1. The order of the pooled ORs for these eight TSGs from more to less significant was CDH1 (OR = 6.73, SLC5 (OR = 6.15, RASSF1 (OR = 4.16, PTEN (OR = 3.61, DAPK (OR = 3.51, P16 (OR = 3.31, TSHR (OR = 2.93, and RARβ2 (OR = 1.50. Analyses of publication bias and sensitivity confirmed that there was very little bias. Thus, our findings showed that CDH1 and SCL5A8 genes were associated with the risk of thyroid tumor genesis.

JWA deficiency suppresses dimethylbenz[a]anthracene-phorbol ester induced skin papillomas via inactivation of MAPK pathway in mice.

Directory of Open Access Journals (Sweden)

Zhenghua Gong

Full Text Available Our previous studies indicated that JWA plays an important role in DNA damage repair, cell migration, and regulation of MAPKs. In this study, we investigated the role of JWA in chemical carcinogenesis using conditional JWA knockout (JWA(Δ2/Δ2 mice and two-stage model of skin carcinogenesis. Our results indicated that JWA(Δ2/Δ2 mice were resistant to the development of skin papillomas initiated by 7, 12-dimethylbenz(aanthracene (DMBA followed by promotion with 12-O-tetradecanoylphorbol-13-acetate (TPA. In JWA(Δ2/Δ2 mice, the induction of papilloma was delayed, and the tumor number and size were reduced. In primary keratinocytes from JWA(Δ2/Δ2 mice, DMBA exposure induced more intensive DNA damage, while TPA-promoted cell proliferation was reduced. The further mechanistic studies showed that JWA deficiency blocked TPA-induced activation of MAPKs and its downstream transcription factor Elk1 both in vitro and in vivo. JWA(Δ2/Δ2 mice are resistance to tumorigenesis induced by DMBA/TPA probably through inhibition of transcription factor Elk1 via MAPKs. These results highlight the importance of JWA in skin homeostasis and in the process of skin tumor development.

Ghrelin and gastrointestinal stromal tumors.

Science.gov (United States)

Zhu, Chang-Zhen; Liu, Dong; Kang, Wei-Ming; Yu, Jian-Chun; Ma, Zhi-Qiang; Ye, Xin; Li, Kang

2017-03-14

Ghrelin, as a kind of multifunctional protein polypeptide, is mainly produced in the fundus of the stomach and can promote occurrence and development of many tumors, including gastrointestinal tumors, which has been proved by the relevant researches. Most gastrointestinal stromal tumors (GISTs, about 80%), as the most common mesenchymal tumor, also develop in the fundus. Scientific research has confirmed that ghrelin, its receptors and mRNA respectively can be found in GISTs, which demonstrated the existence of a ghrelin autocrine/paracrine loop in GIST tissues. However, no reports to date have specified the mechanism whether ghrelin can promote the occurrence and development of GISTs. Studies of pulmonary artery endothelial cells in a low-oxygen environment and cardiac muscle cells in an ischemic environment have shown that ghrelin can activate the phosphatidylinositol 3-kinase/AKT/mammalian target of rapamycin (PI3K/AKT/mTOR) signaling pathway. Moreover, some studies of GISTs have confirmed that activation of the PI3K/AKT/mTOR pathway can indeed promote the growth and progression of GISTs. Whether ghrelin is involved in the development or progression of GISTs through certain pathways remains unknown. Can we find a new target for the treatment of GISTs? This review explores and summaries the relationship among ghrelin, the PI3K/AKT/mTOR pathway and the development of GISTs.

Homeobox B9 is overexpressed in hepatocellular carcinomas and promotes tumor cell proliferation both in vitro and in vivo

International Nuclear Information System (INIS)

Li, Fangyi; Dong, Lei; Xing, Rong; Wang, Li; Luan, Fengming; Yao, Chenhui; Ji, Xuening; Bai, Lizhi

2014-01-01

Highlights: • HOXB9 is overexpressed in human HCC samples. • HOXB9 over expression had shorter survival time than down expression. • HOXB9 stimulated the proliferation of HCC cells. • Activation of TGF-β1 contributes to HOXB9-induced proliferation in HCC cells. - Abstract: HomeoboxB9 (HOXB9), a nontransforming transcription factor that is overexpressed in multiple tumor types, alters tumor cell fate and promotes tumor progression. However, the role of HOXB9 in hepatocellular carcinoma (HCC) development has not been well studied. In this paper, we found that HOXB9 is overexpressed in human HCC samples. We investigated HOXB9 expression and its prognostic value for HCC. HCC surgical tissue samples were taken from 89 HCC patients. HOXB9 overexpression was observed in 65.2% of the cases, and the survival analysis showed that the HOXB9 overexpression group had significantly shorter overall survival time than the HOXB9 downexpression group. The ectopic expression of HOXB9 stimulated the proliferation of HCC cells; whereas the knockdown of HOXB9 produced an opposite effect. HOXB9 also modulated the tumorigenicity of HCC cells in vivo. Moreover, we found that the activation of TGF-β1 contributes to HOXB9-induced proliferation activities. The results provide the first evidence that HOXB9 is a critical regulator of tumor growth factor in HCC

Homeobox B9 is overexpressed in hepatocellular carcinomas and promotes tumor cell proliferation both in vitro and in vivo

Energy Technology Data Exchange (ETDEWEB)

Li, Fangyi [Department of General Surgery, Dalian Municipal Friendship Hospital, No. 8 Sanba Square, Zhongshan District, Dalian 116001 (China); Dong, Lei, E-mail: dlleidong@126.com [Department of Laparoscopic Surgery, First Affiliated Hospital of Dalian Medical University, No. 193 Lianhe Street, Shahekou District, Dalian 116001 (China); Xing, Rong [Department of Pathology and Pathophysiology, Dalian Medical University, No. 9 Lvshunnan Road, Lvshunkou District, Dalian 116044 (China); Wang, Li; Luan, Fengming; Yao, Chenhui [Department of General Surgery, Dalian Municipal Friendship Hospital, No. 8 Sanba Square, Zhongshan District, Dalian 116001 (China); Ji, Xuening [Department of Oncology, Zhongshan Hospital of Dalian University, No. 6 Jiefang Street, Zhongshan District, Dalian 116001 (China); Bai, Lizhi, E-mail: dllizhibai@126.com [Department of Emergency, Zhongshan Hospital of Dalian University, No. 6 Jiefang Street, Zhongshan District, Dalian 116001 (China)

2014-02-07

Highlights: • HOXB9 is overexpressed in human HCC samples. • HOXB9 over expression had shorter survival time than down expression. • HOXB9 stimulated the proliferation of HCC cells. • Activation of TGF-β1 contributes to HOXB9-induced proliferation in HCC cells. - Abstract: HomeoboxB9 (HOXB9), a nontransforming transcription factor that is overexpressed in multiple tumor types, alters tumor cell fate and promotes tumor progression. However, the role of HOXB9 in hepatocellular carcinoma (HCC) development has not been well studied. In this paper, we found that HOXB9 is overexpressed in human HCC samples. We investigated HOXB9 expression and its prognostic value for HCC. HCC surgical tissue samples were taken from 89 HCC patients. HOXB9 overexpression was observed in 65.2% of the cases, and the survival analysis showed that the HOXB9 overexpression group had significantly shorter overall survival time than the HOXB9 downexpression group. The ectopic expression of HOXB9 stimulated the proliferation of HCC cells; whereas the knockdown of HOXB9 produced an opposite effect. HOXB9 also modulated the tumorigenicity of HCC cells in vivo. Moreover, we found that the activation of TGF-β1 contributes to HOXB9-induced proliferation activities. The results provide the first evidence that HOXB9 is a critical regulator of tumor growth factor in HCC.

ADAM12 produced by tumor cells rather than stromal cells accelerates breast tumor progression

DEFF Research Database (Denmark)

Frohlich, Camilla; Nehammer, Camilla; Albrechtsen, Reidar

2011-01-01

that ADAM12 deficiency reduces breast tumor progression in the PyMT model. However, the catalytic activity of ADAM12 appears to be dispensable for its tumor-promoting effect. Interestingly, we demonstrate that ADAM12 endogenously expressed in tumor-associated stroma in the PyMT model does not influence......Expression of ADAM12 is low in most normal tissues, but is markedly increased in numerous human cancers, including breast carcinomas. We have previously shown that overexpression of ADAM12 accelerates tumor progression in a mouse model of breast cancer (PyMT). In the present study, we found...... hypothesized, however, that the tumor-associated stroma may stimulate ADAM12 expression in tumor cells, based on the fact that TGF-ß1 stimulates ADAM12 expression and is a well-known growth factor released from tumor-associated stroma. TGF-ß1 stimulation of ADAM12-negative Lewis lung tumor cells induced ADAM12...

Early impact of social isolation and breast tumor progression in mice.

Science.gov (United States)

Madden, Kelley S; Szpunar, Mercedes J; Brown, Edward B

2013-03-01

Evidence from cancer patients and animal models of cancer indicates that exposure to psychosocial stress can promote tumor growth and metastasis, but the pathways underlying stress-induced cancer pathogenesis are not fully understood. Social isolation has been shown to promote tumor progression. We examined the impact of social isolation on breast cancer pathogenesis in adult female severe combined immunodeficiency (SCID) mice using the human breast cancer cell line, MDA-MB-231, a high β-adrenergic receptor (AR) expressing line. When group-adapted mice were transferred into single housing (social isolation) one week prior to MB-231 tumor cell injection into a mammary fat pad (orthotopic), no alterations in tumor growth or metastasis were detected compared to group-housed mice. When social isolation was delayed until tumors were palpable, tumor growth was transiently increased in singly-housed mice. To determine if sympathetic nervous system activation was associated with increased tumor growth, spleen and tumor norepinephrine (NE) was measured after social isolation, in conjunction with tumor-promoting macrophage populations. Three days after transfer to single housing, spleen weight was transiently increased in tumor-bearing and non-tumor-bearing mice in conjunction with reduced splenic NE concentration and elevated CD11b+Gr-1+ macrophages. At day 10 after social isolation, no changes in spleen CD11b+ populations or NE were detected in singly-housed mice. In the tumors, social isolation increased CD11b+Gr-1+, CD11b+Gr-1-, and F4/80+ macrophage populations, with no change in tumor NE. The results indicate that a psychological stressor, social isolation, elicits dynamic but transient effects on macrophage populations that may facilitate tumor growth. The transiency of the changes in peripheral NE suggest that homeostatic mechanisms may mitigate the impact of social isolation over time. Studies are underway to define the neuroendocrine mechanisms underlying the

Interleukin-8 promotes canine hemangiosarcoma growth by regulating the tumor microenvironment

Energy Technology Data Exchange (ETDEWEB)

Kim, Jong-Hyuk, E-mail: jhkim@umn.edu [Department of Veterinary Clinical Science, College of Veterinary Medicine, University of Minnesota, St. Paul, MN (United States); Masonic Cancer Center, University of Minnesota, Minneapolis, MN (United States); Frantz, Aric M.; Anderson, Katie L.; Graef, Ashley J.; Scott, Milcah C. [Department of Veterinary Clinical Science, College of Veterinary Medicine, University of Minnesota, St. Paul, MN (United States); Robinson, Sally [Department of Veterinary and Biomedical Sciences, College of Veterinary Medicine, University of Minnesota, St. Paul, MN (United States); Sharkey, Leslie C. [Department of Veterinary Clinical Science, College of Veterinary Medicine, University of Minnesota, St. Paul, MN (United States); Masonic Cancer Center, University of Minnesota, Minneapolis, MN (United States); O' Brien, Timothy D. [Department of Veterinary Clinical Science, College of Veterinary Medicine, University of Minnesota, St. Paul, MN (United States); Department of Veterinary Population Medicine, College of Veterinary Medicine, University of Minnesota, St. Paul, MN (United States); Dickerson, Erin B. [Department of Veterinary Clinical Science, College of Veterinary Medicine, University of Minnesota, St. Paul, MN (United States); Masonic Cancer Center, University of Minnesota, Minneapolis, MN (United States); Modiano, Jaime F., E-mail: modiano@umn.edu [Department of Veterinary Clinical Science, College of Veterinary Medicine, University of Minnesota, St. Paul, MN (United States); Masonic Cancer Center, University of Minnesota, Minneapolis, MN (United States)

2014-04-15

Interleukin-8 (IL-8) gene expression is highly up-regulated in canine hemangiosarcoma (HSA); however, its role in the pathogenesis of this disease is unknown. We investigated the expression of IL-8 in canine HSA tissues and cell lines, as well and the effects of IL-8 on canine HSA in vitro, and in vivo using a mouse xenograft model for the latter. Constitutive expression of IL-8 mRNA, IL-8 protein, and IL-8 receptor were variable among different tumor samples and cell lines, but they showed stable steady states in each cell line. Upon the addition of IL-8, HSA cells showed transient intracellular calcium fluxes, suggesting that their IL-8 receptors are functional and that IL-8 binding activates relevant signaling pathways. Yet, neither addition of exogenous IL-8 nor blockade of endogenous IL-8 by neutralizing anti-IL-8 antibody (α-IL-8 Ab) affected HSA cell proliferation or survival in vitro. To assess potential effects of IL-8 in other tumor constituents, we stratified HSA cell lines and whole tumor samples into “IL-8 high” and “IL-8 low” groups. Genome-wide gene expression profiling showed that samples in the “IL-8 high” tumor group were enriched for genes associated with a “reactive microenvironment,” including activation of coagulation, inflammation, and fibrosis networks. Based on these findings, we hypothesized that the effects of IL-8 on these tumors were mostly indirect, regulating interactions with the microenvironment. This hypothesis was supported by in vivo xenograft experiments where survival and engraftment of tumor cells was inhibited by administration of neutralizing α-IL-8 Ab. Together, our results suggest that IL-8 contributes to establishing a permissive microenvironment during the early stages of tumorigenesis in HSA. - Highlights: • IL-8 is expressed in canine hemangiosarcoma tumor samples and cell lines. • IL-8 transduces a relevant biological signal in canine hemangiosarcoma cells. • IL-8 gene signature is associated

Interleukin-8 promotes canine hemangiosarcoma growth by regulating the tumor microenvironment

International Nuclear Information System (INIS)

Kim, Jong-Hyuk; Frantz, Aric M.; Anderson, Katie L.; Graef, Ashley J.; Scott, Milcah C.; Robinson, Sally; Sharkey, Leslie C.; O'Brien, Timothy D.; Dickerson, Erin B.; Modiano, Jaime F.

2014-01-01

Interleukin-8 (IL-8) gene expression is highly up-regulated in canine hemangiosarcoma (HSA); however, its role in the pathogenesis of this disease is unknown. We investigated the expression of IL-8 in canine HSA tissues and cell lines, as well and the effects of IL-8 on canine HSA in vitro, and in vivo using a mouse xenograft model for the latter. Constitutive expression of IL-8 mRNA, IL-8 protein, and IL-8 receptor were variable among different tumor samples and cell lines, but they showed stable steady states in each cell line. Upon the addition of IL-8, HSA cells showed transient intracellular calcium fluxes, suggesting that their IL-8 receptors are functional and that IL-8 binding activates relevant signaling pathways. Yet, neither addition of exogenous IL-8 nor blockade of endogenous IL-8 by neutralizing anti-IL-8 antibody (α-IL-8 Ab) affected HSA cell proliferation or survival in vitro. To assess potential effects of IL-8 in other tumor constituents, we stratified HSA cell lines and whole tumor samples into “IL-8 high” and “IL-8 low” groups. Genome-wide gene expression profiling showed that samples in the “IL-8 high” tumor group were enriched for genes associated with a “reactive microenvironment,” including activation of coagulation, inflammation, and fibrosis networks. Based on these findings, we hypothesized that the effects of IL-8 on these tumors were mostly indirect, regulating interactions with the microenvironment. This hypothesis was supported by in vivo xenograft experiments where survival and engraftment of tumor cells was inhibited by administration of neutralizing α-IL-8 Ab. Together, our results suggest that IL-8 contributes to establishing a permissive microenvironment during the early stages of tumorigenesis in HSA. - Highlights: • IL-8 is expressed in canine hemangiosarcoma tumor samples and cell lines. • IL-8 transduces a relevant biological signal in canine hemangiosarcoma cells. • IL-8 gene signature is associated

Protective effect of U74500A on phorbol myristate acetate-induced acute lung injury.

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Chu, Shi-Jye; Chang, Deh-Ming; Wang, David; Lin, Hen-I; Lin, Shih-Hua; Hsu, Kang

2004-08-01

1. The present study was designed to determine whether U74500A could ameliorate acute lung injury (ALI) induced by phorbol myristate acetate (PMA) in our rat isolated lung model compared with any amelioration induced by dimethylthiourea (DMTU), superoxide dismutase (SOD) and catalase. 2. Acute lung injury was induced successfully by PMA during 60 min of observation. At 2 microg/kg, PMA elicited a significant increase in microvascular permeability (measured using the capillary filtration coefficient Kfc), lung weight gain, the lung weight/bodyweight ratio, pulmonary arterial pressure and protein concentration of the bronchoalveolar lavage fluid. 3. Pretreatment with 1.5 mg/kg U74500A significantly attenuated ALI; there was no significant increase in any parameters measured, except for pulmonary arterial pressure. The protective effect of U74500A was approximately the same as that of 600 mg/kg DMTU. However, 6000 U/kg SOD, 50,000 U/kg catalase and 6000 U/kg SOD + 50,000 U/kg catalase had no protective effect. 4. These experimental data suggest that U74500A significantly ameliorates ALI induced by PMA in rats.

Tissue Specific Promoters in Colorectal Cancer

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A. R. Rama

2015-01-01

Full Text Available Colorectal carcinoma is the third most prevalent cancer in the world. In the most advanced stages, the use of chemotherapy induces a poor response and is usually accompanied by other tissue damage. Significant progress based on suicide gene therapy has demonstrated that it may potentiate the classical cytotoxic effects in colorectal cancer. The inconvenience still rests with the targeting and the specificity efficiency. The main target of gene therapy is to achieve an effective vehicle to hand over therapeutic genes safely into specific cells. One possibility is the use of tumor-specific promoters overexpressed in cancers. They could induce a specific expression of therapeutic genes in a given tumor, increasing their localized activity. Several promoters have been assayed into direct suicide genes to cancer cells. This review discusses the current status of specific tumor-promoters and their great potential in colorectal carcinoma treatment.

Perlecan and tumor angiogenesis

DEFF Research Database (Denmark)

Jiang, Xinnong; Couchman, John R

2003-01-01

Perlecan is a major heparan sulfate proteoglycan (HSPG) of basement membranes (BMs) and connective tissues. The core protein of perlecan is divided into five domains based on sequence homology to other known proteins. Commonly, the N-terminal domain I of mammalian perlecan is substituted with thr...... have unwanted promoting effects on tumor cell proliferation and tumor angiogenesis. Understanding of these attributes at the molecular level may offer opportunities for therapeutic intervention....

Development of chimeric gene promoters responsive to hypoxia and ionizing radiation

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Zheng Aiqing; Yu Jinming

2004-01-01

The authors describe two systems that make use of gene-directed enzyme prodrug therapy, regulated by radiation or hypoxic-responsive promoters. The use of treatment-, condition- or tumor-specific promoters to control gene-directed enzyme prodrug therapy is one such method for targeting gene expression to the tumor. The development of such strategies that achieve tumor targeted expression of genes via selective promoters will enable improved specificity and targeting thereby addressing one of the major limitations of cancer gene therapy

Cooperative effects of aminopeptidase N (CD13) expressed by nonmalignant and cancer cells within the tumor microenvironment.

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Guzman-Rojas, Liliana; Rangel, Roberto; Salameh, Ahmad; Edwards, Julianna K; Dondossola, Eleonora; Kim, Yun-Gon; Saghatelian, Alan; Giordano, Ricardo J; Kolonin, Mikhail G; Staquicini, Fernanda I; Koivunen, Erkki; Sidman, Richard L; Arap, Wadih; Pasqualini, Renata

2012-01-31

Processes that promote cancer progression such as angiogenesis require a functional interplay between malignant and nonmalignant cells in the tumor microenvironment. The metalloprotease aminopeptidase N (APN; CD13) is often overexpressed in tumor cells and has been implicated in angiogenesis and cancer progression. Our previous studies of APN-null mice revealed impaired neoangiogenesis in model systems without cancer cells and suggested the hypothesis that APN expressed by nonmalignant cells might promote tumor growth. We tested this hypothesis by comparing the effects of APN deficiency in allografted malignant (tumor) and nonmalignant (host) cells on tumor growth and metastasis in APN-null mice. In two independent tumor graft models, APN activity in both the tumors and the host cells cooperate to promote tumor vascularization and growth. Loss of APN expression by the host and/or the malignant cells also impaired lung metastasis in experimental mouse models. Thus, cooperation in APN expression by both cancer cells and nonmalignant stromal cells within the tumor microenvironment promotes angiogenesis, tumor growth, and metastasis.

Although Abundant in Tumor Tissue, Mast Cells Have No Effect on Immunological Micro-milieu or Growth of HPV-Induced or Transplanted Tumors

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Shanawaz Mohammed Ghouse

2018-01-01

Full Text Available Summary: High numbers of mast cells populate the stroma of many types of neoplasms, including human papilloma virus-induced benign and malignant tumors in man and mouse. Equipped with numerous pattern recognition receptors and capable of executing important pro-inflammatory responses, mast cells are considered innate sentinels that significantly impact tumor biology. Mast cells were reported to promote human papilloma virus (HPV-induced epithelial hyperproliferation and neo-angiogenesis in an HPV-driven mouse model of skin cancer. We analyzed HPV-induced epithelial hyperplasia and squamous cell carcinoma formation, as well as growth of tumors inoculated into the dermis, in mice lacking skin mast cells. Unexpectedly, the absence of mast cells had no effect on HPV-induced epithelial growth or angiogenesis, on growth kinetics of inoculated tumors, or on the immunological tumor micro-milieu. Thus, the conspicuous recruitment of mast cells into tumor tissues cannot necessarily be equated with important mast cell functions in tumor growth. : Mast cells accumulate in high numbers in many human tumors, and they are widely viewed as important promoters of tumor growth. Ghouse et al. show that growth, angiogenesis, and the immunological micro-milieu of tumors growing in mice genetically deficient for mast cells are unchanged compared to control tumors. Keywords: mast cells, HPV-induced skin cancer, tumor angiogenesis, tumor micro-milieu

Multiparametric classification links tumor microenvironments with tumor cell phenotype.

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Bojana Gligorijevic

2014-11-01

Full Text Available While it has been established that a number of microenvironment components can affect the likelihood of metastasis, the link between microenvironment and tumor cell phenotypes is poorly understood. Here we have examined microenvironment control over two different tumor cell motility phenotypes required for metastasis. By high-resolution multiphoton microscopy of mammary carcinoma in mice, we detected two phenotypes of motile tumor cells, different in locomotion speed. Only slower tumor cells exhibited protrusions with molecular, morphological, and functional characteristics associated with invadopodia. Each region in the primary tumor exhibited either fast- or slow-locomotion. To understand how the tumor microenvironment controls invadopodium formation and tumor cell locomotion, we systematically analyzed components of the microenvironment previously associated with cell invasion and migration. No single microenvironmental property was able to predict the locations of tumor cell phenotypes in the tumor if used in isolation or combined linearly. To solve this, we utilized the support vector machine (SVM algorithm to classify phenotypes in a nonlinear fashion. This approach identified conditions that promoted either motility phenotype. We then demonstrated that varying one of the conditions may change tumor cell behavior only in a context-dependent manner. In addition, to establish the link between phenotypes and cell fates, we photoconverted and monitored the fate of tumor cells in different microenvironments, finding that only tumor cells in the invadopodium-rich microenvironments degraded extracellular matrix (ECM and disseminated. The number of invadopodia positively correlated with degradation, while the inhibiting metalloproteases eliminated degradation and lung metastasis, consistent with a direct link among invadopodia, ECM degradation, and metastasis. We have detected and characterized two phenotypes of motile tumor cells in vivo, which

Comparative tumor promotion assessment of e-cigarette and cigarettes using the in vitro Bhas 42 cell transformation assay.

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Breheny, Damien; Oke, Oluwatobiloba; Pant, Kamala; Gaça, Marianna

2017-05-01

In vitro cell transformation assays (CTA) are used to assess the carcinogenic potential of chemicals and complex mixtures and can detect nongenotoxic as well as genotoxic carcinogens. The Bhas 42 CTA has been developed with both initiation and promotion protocols to distinguish between these two carcinogen classes. Cigarette smoke is known to be carcinogenic and is positive in in vitro genotoxicity assays. Cigarette smoke also contains nongenotoxic carcinogens and is a tumour promoter and cocarcinogen in vivo. We have combined a suite of in vitro assays to compare the relative biological effects of new categories of tobacco and nicotine products with traditional cigarettes. The Bhas promotion assay has been included in this test battery to provide an in vitro surrogate for detecting tumor promoters. The activity of an electronic cigarette (e-cigarette; Vype ePen) was compared to that of a reference cigarette (3R4F) in the promotion assay, using total particulate matter (TPM)/aerosol collected matter (ACM) and aqueous extracts (AqE) of product aerosol emissions. 3R4F TPM was positive in this assay at concentrations ≥6 µg/mL, while e-cigarette ACM did not have any promoter activity. AqE was found to be a lesssuitable test matrix in this assay due to high cytotoxicity. This is the first study to use the Bhas assay to compare tobacco and nicotine products and demonstrates the potential for its future application as part of a product assessment framework. These data add to growing evidence suggesting that e-cigarettes may provide a safer alternative to traditional cigarettes. Environ. Mol. Mutagen. 58:190-198, 2017. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.

Interleukin-34 promotes tumor progression and metastatic process in osteosarcoma through induction of angiogenesis and macrophage recruitment.

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Ségaliny, Aude I; Mohamadi, Amel; Dizier, Blandine; Lokajczyk, Anna; Brion, Régis; Lanel, Rachel; Amiaud, Jérôme; Charrier, Céline; Boisson-Vidal, Catherine; Heymann, Dominique

2015-07-01

Interleukin-34 (IL-34) was recently characterized as the M-CSF "twin" cytokine, regulating the proliferation/differentiation/survival of myeloid cells. The implication of M-CSF in oncology was initially suspected by the reduced metastatic dissemination in knock-out mice, due to angiogenesis impairment. Based on this observation, our work studied the involvement of IL-34 in the pathogenesis of osteosarcoma. The in vivo effects of IL-34 were assessed on tissue vasculature and macrophage infiltration in a murine preclinical model based on a paratibial inoculation of human osteosarcoma cells overexpressing or not IL-34 or M-CSF. In vitro investigations using endothelial cell precursors and mature HUVEC cells were performed to analyse the involvement of IL-34 in angiogenesis and myeloid cell adhesion. The data revealed that IL-34 overexpression was associated with the progression of osteosarcoma (tumor growth, lung metastases) and an increase of neo-angiogenesis. In vitro analyses demonstrated that IL-34 stimulated endothelial cell proliferation and vascular cord formation. Pre-treatment of endothelial cells by chondroitinases/heparinases reduced the formation of vascular tubes and abolished the associated cell signalling. In addition, IL-34 increased the in vivo recruitment of M2 tumor-associated macrophages into the tumor tissue. IL-34 increased in vitro monocyte/CD34(+) cell adhesion to activated HUVEC monolayers under physiological shear stress conditions. This work also demonstrates that IL-34 is expressed by osteosarcoma cells, is regulated by TNF-α, IL-1β, and contributes to osteosarcoma growth by increasing the neo-angiogenesis and the recruitment of M2 macrophages. By promoting new vessel formation and extravasation of immune cells, IL-34 may play a key role in tumor development and inflammatory diseases. © 2014 UICC.

Enzymatic Phorbol Esters Degradation using the Germinated Jatropha Curcas Seed Lipase as Biocatalyst: Optimization Process Conditions by Response Surface Methodology

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Avita Kusuma Wardhani

2016-10-01

Full Text Available Utilization of Jatropha curcas seed cake is limited by the presence of phorbol esters (PE, which are the main toxic compound and heat stable. The objective of this research was to optimize the reaction conditions of the enzymatic PE degradation of the defatted Jatropha curcas seed cake (DJSC using the acetone-dried lipase from the germinated Jatropha curcas seeds as a biocatalyst. Response Surface Methodology (RSM using three-factors-three-levels Box-Behnken design was used to evaluate the effects of the reaction time, the ratio of buffer volume to DJSC, and the ratio of enzyme to DJSC on PE degradation. The results showed that the optimum conditions of PE degradation were 29.33 h, 51.11 : 6 (mL/g, and 30.10 : 5 (U/g cake for the reaction time, the ratio of buffer volume to DJSC, and the ratio of enzyme to DJSC, respectively. The predicted degradation of PE was 98.96% and not significantly different with the validated data of PE degradation. PE content was 0.035 mg/g, in which it was lower than PE in non-toxic Jatropha seeds. The results indicated that enzymatic degradation of PE might be a promising method for degradation of PE.  Copyright © 2016 BCREC GROUP. All rights reserved Received: 22nd December 2015; Revised: 1st April 2016; Accepted: 14th April 2016 How to Cite: Wardhani, A.K., Hidayat, C., Hastuti, P. (2016. Enzymatic Phorbol Esters Degradation using the Germinated Jatropha Curcas Seed Lipase as Biocatalyst: Optimization Process Conditions by Response Surface Methodology. Bulletin of Chemical Reaction Engineering & Catalysis, 11 (3: 346-353 (doi:10.9767/bcrec.11.3.574.346-353 Permalink/DOI: http://doi.org/10.9767/bcrec.11.3.574.346-353

Tumor-promoting function and prognostic significance of the RNA-binding protein T-cell intracellular antigen-1 in esophageal squamous cell carcinoma.

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Hamada, Junichi; Shoda, Katsutoshi; Masuda, Kiyoshi; Fujita, Yuji; Naruto, Takuya; Kohmoto, Tomohiro; Miyakami, Yuko; Watanabe, Miki; Kudo, Yasusei; Fujiwara, Hitoshi; Ichikawa, Daisuke; Otsuji, Eigo; Imoto, Issei

2016-03-29

T-cell intracellular antigen-1 (TIA1) is an RNA-binding protein involved in many regulatory aspects of mRNA metabolism. Here, we report previously unknown tumor-promoting activity of TIA1, which seems to be associated with its isoform-specific molecular distribution and regulation of a set of cancer-related transcripts, in esophageal squamous cell carcinoma (ESCC). Immunohistochemical overexpression of TIA1 ectopically localized in the cytoplasm of tumor cells was an independent prognosticator for worse overall survival in a cohort of 143 ESCC patients. Knockdown of TIA1 inhibited proliferation of ESCC cells. By exogenously introducing each of two major isoforms, TIA1a and TIA1b, only TIA1a, which was localized to both the nucleus and cytoplasm, promoted anchorage-dependent and anchorage-independent ESCC cell proliferation. Ribonucleoprotein immunoprecipitation, followed by microarray analysis or massive-parallel sequencing, identified a set of TIA1-binding mRNAs, including SKP2 and CCNA2. TIA1 increased SKP2 and CCNA2 protein levels through the suppression of mRNA decay and translational induction, respectively. Our findings uncover a novel oncogenic function of TIA1 in esophageal tumorigenesis, and implicate its use as a marker for prognostic evaluation and as a therapeutic target in ESCC.

TRIP-Br2 promotes oncogenesis in nude mice and is frequently overexpressed in multiple human tumors

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Peh Bee

2009-01-01

Full Text Available Abstract Background Members of the TRIP-Br/SERTAD family of mammalian transcriptional coregulators have recently been implicated in E2F-mediated cell cycle progression and tumorigenesis. We, herein, focus on the detailed functional characterization of the least understood member of the TRIP-Br/SERTAD protein family, TRIP-Br2 (SERTAD2. Methods Oncogenic potential of TRIP-Br2 was demonstrated by (1 inoculation of NIH3T3 fibroblasts, which were engineered to stably overexpress ectopic TRIP-Br2, into athymic nude mice for tumor induction and (2 comprehensive immunohistochemical high-throughput screening of TRIP-Br2 protein expression in multiple human tumor cell lines and human tumor tissue microarrays (TMAs. Clinicopathologic analysis was conducted to assess the potential of TRIP-Br2 as a novel prognostic marker of human cancer. RNA interference of TRIP-Br2 expression in HCT-116 colorectal carcinoma cells was performed to determine the potential of TRIP-Br2 as a novel chemotherapeutic drug target. Results Overexpression of TRIP-Br2 is sufficient to transform murine fibroblasts and promotes tumorigenesis in nude mice. The transformed phenotype is characterized by deregulation of the E2F/DP-transcriptional pathway through upregulation of the key E2F-responsive genes CYCLIN E, CYCLIN A2, CDC6 and DHFR. TRIP-Br2 is frequently overexpressed in both cancer cell lines and multiple human tumors. Clinicopathologic correlation indicates that overexpression of TRIP-Br2 in hepatocellular carcinoma is associated with a worse clinical outcome by Kaplan-Meier survival analysis. Small interfering RNA-mediated (siRNA knockdown of TRIP-Br2 was sufficient to inhibit cell-autonomous growth of HCT-116 cells in vitro. Conclusion This study identifies TRIP-Br2 as a bona-fide protooncogene and supports the potential for TRIP-Br2 as a novel prognostic marker and a chemotherapeutic drug target in human cancer.

Potentiation of phorbol ester-induced coronary vasoconstriction in dogs following endothelium disruption

International Nuclear Information System (INIS)

Roberts, R.B.; Ku, D.D.

1986-01-01

In the present study, the effect of phorbol ester, 12-0-tetradecanoylphorbol 13-acetate (TPA), activation of protein kinase C on coronary vascular reactivity was studied in isolated dog coronary arteries. Addition of TPA (10-100 nM) produced a slow, time- and dose-dependent contraction reaching a maximum at approx 2-3 hrs and was essentially irreversible upon washing. Disruption of the endothelium(EC) greatly accelerated the development as well as increase the magnitude of TPA contraction (50-100%). Prior treatment of vessels with phentolamine (1μM), cyproheptadine (1μH) and ibuprofen (1μg/ml) did not alter the TPA contraction. Furthermore, in contrast to previously reported calcium-dependence of TPA contraction in other vessels, complete removal of extracellular calcium (Ca 0 ) or addition of 1μM nimodipine after TPA(30nM) resulted in only 32 +/- 4% and 25 +/- 3% reversal of TPA contraction, respectively. Addition of amiloride (10μM to 1mM), however, resulted in a dose-dependent reversal of TPA contraction. The results of the present study indicate that a similar activation of protein kinase C by TPA leads to potent coronary vasoconstriction, which is not completely dependent on Ca 0 . More importantly, these results further support their hypothesis that EC also functions as an inhibitory barrier to prevent circulating vasoconstrictors from exerting their deleterious constrictory effects

Role of chemical carcinogens in epithelial and mesenchymal neoplasms with tumor initiation-promotion protocol and the effect of 13-cis retinoic acid in chemo prevention

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Bukhari, S.M.H.; Shahzad, S.Q.; Naeem, S.; Qureshi, G.R.; Naveed, I.A.

2002-01-01

Objective: To study the effects of chemical carcinogens on epithelial and mesenchymal tumorigenesis with tumor initiation-promotion protocol and the use of 13-cis retinoic acid as a chemo preventive agent. Design: It was an experimental study. Place and Duration of Study: The study was conducted at Postgraduate Medical Institute (PGML) Lahore for 20 weeks. Materials and Methods: Sixty albino rats were divided into six groups of ten of animals each. First group of animals (control) was not given carcinogens and 13-cis retinoic acid in second group DMBA was applied on the dorsal skin in repeated dos of 100 mu g/ml in acetone, twice a weak. In the third group DMBA was given 100 mu g/ml as single dose while TPA was given 10 mu g//ml in acetone, twice a weak after two weeks of DMBA applications. In fourth group only DMBA 100 mu g/ml in acetone was applied as a single dose. In fifth and sixth groups 13-cis retinoic acid was given topically before and after the application of DMBA and TPA. Results: First and fourth groups did not develop any tumor. In second groups 2 animals developed malignant fibrous histiocytoma, 4 squamous cell carcinoma while 1 dysphasia and 1 carcinoma in situ. Third group developed osteoma (3 animals), papilloma (3 animals, squamous cell carcinoma (01) and dysplasia (01). Conclusion: Our results showed that DMBA acts as tumor initiator while TPA as promoter. DMBA also produces tumors itself when given alone in repeated doses. The chemical carcinogens are not only a cause of epithelial carcinogenesis but also responsible for mesenchymal tumorigenesis. 13 cis retinoic acid was equally effective in both stages of tumorigenesis. It also prevents malignant conversion of chemically induced benign tumors. (author)

Involvement of phorbol-12-myristate-13-acetate-induced protein 1 in goniothalamin-induced TP53-dependent and -independent apoptosis in hepatocellular carcinoma-derived cells

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Kuo, Kung-Kai; Chen, Yi-Ling; Chen, Lih-Ren; Li, Chien-Feng; Lan, Yu-Hsuan; Chang, Fang-Rong; Wu, Yang-Chang; Shiue, Yow-Ling

2011-01-01

The objective was to investigate the upstream apoptotic mechanisms that were triggered by a styrylpyrone derivative, goniothalamin (GTN), in tumor protein p53 (TP53)-positive and -negative hepatocellular carcinoma (HCC)-derived cells. Effects of GTN were evaluated by the flow cytometry, alkaline comet assay, immunocytochemistry, small-hairpin RNA interference, mitochondria/cytosol fractionation, quantitative reverse transcription-polymerase chain reaction, immunoblotting analysis and caspase 3 activity assays in two HCC-derived cell lines. Results indicated that GTN triggered phorbol-12-myristate-13-acetate-induced protein 1 (PMAIP1, also known as NOXA)-mediated apoptosis via TP53-dependent and -independent pathways. In TP53-positive SK-Hep1 cells, GTN furthermore induced TP53 transcription-dependent and -independent apoptosis. After GTN treatment, accumulation of reactive oxygen species, formation of DNA double-strand breaks, transactivation of TP53 and/or PMAIP1 gene, translocation of TP53 and/or PMAIP1 proteins to mitochondria, release of cytochrome c from mitochondria, cleavage of caspases and induction of apoptosis in both cell lines were sustained. GTN might represent a novel class of anticancer drug that induces apoptosis in HCC-derived cells through PMAIP1 transactivation regardless of the status of TP53 gene. - Highlights: → Goniothalamin (GTN) induced apoptosis in hepatocellular carcinomas-derived cells. → The apoptosis induced by GTN is PMAIP1-dependent, regardless of TP53 status. → The apoptosis induced by GTN might be TP53 transcription-dependent or -independent. → GTN-induced apoptosis is mitochondria- and caspases-mediated.

Promoter methylation of APC and RAR-β genes as prognostic markers in non-small cell lung cancer (NSCLC).

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Feng, Hongxiang; Zhang, Zhenrong; Qing, Xin; Wang, Xiaowei; Liang, Chaoyang; Liu, Deruo

2016-02-01

Aberrant promoter hypermethylations of tumor suppressor genes are promising markers for lung cancer diagnosis and prognosis. The purpose of this study was to determine methylation status at APC and RAR-β promoters in primary NSCLC, and whether they have any relationship with survival. APC and RAR-β promoter methylation status were determined in 41 NSCLC patients using methylation specific PCR. APC promoter methylation was detectable in 9 (22.0%) tumor samples and 6 (14.6%) corresponding non-tumor samples (P=0.391). RAR-β promoter methylation was detectable in 13 (31.7%) tumor samples and 4 (9.8%) corresponding non-tumor samples (P=0.049) in the NSCLC patients. APC promoter methylation was found to be associated with T stage (P=0.046) and nodal status (P=0.019) in non-tumor samples, and with smoking (P=0.004) in tumor samples. RAR-β promoter methylation was found associated with age (P=0.031) in non-tumor samples and with primary tumor site in tumor samples. Patients with APC promoter methylation in tumor samples showed significantly longer survival than patients without it (Log-rank P=0.014). In a multivariate analysis of prognostic factors, APC methylation in tumor samples was an independent prognostic factor (P=0.012), as were N1 positive lymph node number (P=0.025) and N2 positive lymph node number (P=0.06). Our study shows that RAR-β methylation detected in lung tissue may be used as a predictive marker for NSCLC diagnosis and that APC methylation in tumor sample may be a useful marker for superior survival in NSCLC patients. Copyright © 2015. Published by Elsevier Inc.

Gene Electrotransfer of Plasmid with Tissue Specific Promoter Encoding shRNA against Endoglin Exerts Antitumor Efficacy against Murine TS/A Tumors by Vascular Targeted Effects.

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Monika Stimac

Full Text Available Vascular targeted therapies, targeting specific endothelial cell markers, are promising approaches for the treatment of cancer. One of the targets is endoglin, transforming growth factor-β (TGF-β co-receptor, which mediates proliferation, differentiation and migration of endothelial cells forming neovasculature. However, its specific, safe and long-lasting targeting remains the challenge. Therefore, in our study we evaluated the transfection efficacy, vascular targeted effects and therapeutic potential of the plasmid silencing endoglin with the tissue specific promoter, specific for endothelial cells marker endothelin-1 (ET (TS plasmid, in comparison to the plasmid with constitutive promoter (CON plasmid, in vitro and in vivo. Tissue specificity of TS plasmid was demonstrated in vitro on several cell lines, and its antiangiogenic efficacy was demonstrated by reducing tube formation of 2H11 endothelial cells. In vivo, on a murine mammary TS/A tumor model, we demonstrated good antitumor effect of gene electrotransfer (GET of either of both plasmids in treatment of smaller tumors still in avascular phase of growth, as well as on bigger tumors, already well vascularized. In support to the observations on predominantly vascular targeted effects of endoglin, histological analysis has demonstrated an increase in necrosis and a decrease in the number of blood vessels in therapeutic groups. A significant antitumor effect was observed in tumors in avascular and vascular phase of growth, possibly due to both, the antiangiogenic and the vascular disrupting effect. Furthermore, the study indicates on the potential use of TS plasmid in cancer gene therapy since the same efficacy as of CON plasmid was determined.

Gene Electrotransfer of Plasmid with Tissue Specific Promoter Encoding shRNA against Endoglin Exerts Antitumor Efficacy against Murine TS/A Tumors by Vascular Targeted Effects.

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Stimac, Monika; Dolinsek, Tanja; Lampreht, Ursa; Cemazar, Maja; Sersa, Gregor

2015-01-01

Vascular targeted therapies, targeting specific endothelial cell markers, are promising approaches for the treatment of cancer. One of the targets is endoglin, transforming growth factor-β (TGF-β) co-receptor, which mediates proliferation, differentiation and migration of endothelial cells forming neovasculature. However, its specific, safe and long-lasting targeting remains the challenge. Therefore, in our study we evaluated the transfection efficacy, vascular targeted effects and therapeutic potential of the plasmid silencing endoglin with the tissue specific promoter, specific for endothelial cells marker endothelin-1 (ET) (TS plasmid), in comparison to the plasmid with constitutive promoter (CON plasmid), in vitro and in vivo. Tissue specificity of TS plasmid was demonstrated in vitro on several cell lines, and its antiangiogenic efficacy was demonstrated by reducing tube formation of 2H11 endothelial cells. In vivo, on a murine mammary TS/A tumor model, we demonstrated good antitumor effect of gene electrotransfer (GET) of either of both plasmids in treatment of smaller tumors still in avascular phase of growth, as well as on bigger tumors, already well vascularized. In support to the observations on predominantly vascular targeted effects of endoglin, histological analysis has demonstrated an increase in necrosis and a decrease in the number of blood vessels in therapeutic groups. A significant antitumor effect was observed in tumors in avascular and vascular phase of growth, possibly due to both, the antiangiogenic and the vascular disrupting effect. Furthermore, the study indicates on the potential use of TS plasmid in cancer gene therapy since the same efficacy as of CON plasmid was determined.

Radiogenetic therapy: strategies to overcome tumor resistance.

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Marples, B; Greco, O; Joiner, M C; Scott, S D

2003-01-01

The aim of cancer gene therapy is to selectively kill malignant cells at the tumor site, by exploiting traits specific to cancer cells and/or solid tumors. Strategies that take advantage of biological features common to different tumor types are particularly promising, since they have wide clinical applicability. Much attention has focused on genetic methods that complement radiotherapy, the principal treatment modality, or that exploit hypoxia, the most ubiquitous characteristic of most solid cancers. The goal of this review is to highlight two promising gene therapy methods developed specifically to target the tumor volume that can be readily used in combination with radiotherapy. The first approach uses radiation-responsive gene promoters to control the selective expression of a suicide gene (e.g., herpes simplex virus thymidine kinase) to irradiated tissue only, leading to targeted cell killing in the presence of a prodrug (e.g., ganciclovir). The second method utilizes oxygen-dependent promoters to produce selective therapeutic gene expression and prodrug activation in hypoxic cells, which are refractive to conventional radiotherapy. Further refining of tumor targeting can be achieved by combining radiation and hypoxia responsive elements in chimeric promoters activated by either and dual stimuli. The in vitro and in vivo studies described in this review suggest that the combination of gene therapy and radiotherapy protocols has potential for use in cancer care, particularly in cases currently refractory to treatment as a result of inherent or hypoxia-mediated radioresistance.

Fibroblast growth factor receptor 1 activation in mammary tumor cells promotes macrophage recruitment in a CX3CL1-dependent manner.

Directory of Open Access Journals (Sweden)

Johanna R Reed

Full Text Available Tumor formation is an extensive process requiring complex interactions that involve both tumor cell-intrinsic pathways and soluble mediators within the microenvironment. Tumor cells exploit the intrinsic functions of many soluble molecules, including chemokines and their receptors, to regulate pro-tumorigenic phenotypes that are required for growth and progression of the primary tumor. Previous studies have shown that activation of inducible FGFR1 (iFGFR1 in mammary epithelial cells resulted in increased proliferation, migration, and invasion in vitro and tumor formation in vivo. These studies also demonstrated that iFGFR1 activation stimulated recruitment of macrophages to the epithelium where macrophages contributed to iFGFR1-mediated epithelial cell proliferation and angiogenesis. The studies presented here further utilize this model to identify the mechanisms that regulate FGFR1-induced macrophage recruitment. Results from this study elucidate a novel role for the inflammatory chemokine CX3CL1 in FGFR1-induced macrophage migration. Specifically, we illustrate that activation of both the inducible FGFR1 construct in mouse mammary epithelial cells and endogenous FGFR in the triple negative breast cancer cell line, HS578T, leads to expression of the chemokine CX3CL1. Furthermore, we demonstrate that FGFR-induced CX3CL1 is sufficient to recruit CX3CR1-expressing macrophages in vitro. Finally, blocking CX3CR1 in vivo leads to decreased iFGFR1-induced macrophage recruitment, which correlates with decreased angiogenesis. While CX3CL1 is a known target of FGF signaling in the wound healing environment, these studies demonstrate that FGFR activation also leads to induction of CX3CL1 in a tumor setting. Furthermore, these results define a novel role for CX3CL1 in promoting macrophage recruitment during mammary tumor formation, suggesting that the CX3CL1/CX3CR1 axis may represent a potential therapeutic approach for targeting breast cancers associated

Recurrence in oral and pharyngeal cancer is associated with quantitative MGMT promoter methylation

International Nuclear Information System (INIS)

Taioli, Emanuela; Ragin, Camille; Wang, Xiao-hong; Chen, Jiangying; Langevin, Scott M; Brown, Ashley R; Gollin, Susanne M; Garte, Seymour; Sobol, Robert W

2009-01-01

Biomarkers that predict clinical response, tumor recurrence or patient survival are severely lacking for most cancers, particularly for oral and pharyngeal cancer. This study examines whether gene-promoter methylation of tumor DNA correlates with survival and recurrence rates in a population of patients with oral or pharyngeal cancer. The promoter methylation status of the DNA repair gene MGMT and the tumor suppressor genes CDKN2A and RASSF1 were evaluated by methylation-specific PCR in 88 primary oral and pharyngeal tumors and correlated with survival and tumor recurrence. Quantitative MGMT methylation was also assessed. 29.6% of the tumors presented with MGMT methylation, 11.5% with CDKN2A methylation and 12.1% with RASSF1 methylation. MGMT promoter methylation was significantly associated with poorer overall and disease-free survival. No differences in methylation status of MGMT and RASSF1 with HPV infection, smoking or drinking habits were observed. A significant inverse trend with the amount of MGMT methylation and overall and disease-free survival was observed (p trend = 0.002 and 0.001 respectively). These results implicate MGMT promoter methylation as a possible biomarker for oral and pharyngeal cancer prognosis. The critical role of MGMT in DNA repair suggests that defective DNA repair may be correlative in the observed association between MGMT promoter methylation and tumor recurrence. Follow-up studies should include further quantitative MSP-PCR measurement, global methylation profiling and detailed analysis of downstream DNA repair genes regulated by promoter methylation

mTOR at the Transmitting and Receiving Ends in Tumor Immunity.

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Guri, Yakir; Nordmann, Thierry M; Roszik, Jason

2018-01-01

Cancer is a complex disease and a leading cause of death worldwide. Immunity is critical for cancer control. Cancer cells exhibit high mutational rates and therefore altered self or neo-antigens, eliciting an immune response to promote tumor eradication. Failure to mount a proper immune response leads to cancer progression. mTOR signaling controls cellular metabolism, immune cell differentiation, and effector function. Deregulated mTOR signaling in cancer cells modulates the tumor microenvironment, thereby affecting tumor immunity and possibly promoting carcinogenesis.

Homocysteine Is an Oncometabolite in Breast Cancer, Which Promotes Tumor Progression and Metastasis

Science.gov (United States)

2014-09-01

increase in breast cancer, which results in changes in gene expression in tumor cells helping the tumors to grow and metastasize. The molecular basis...in changes in gene expression in tumor cells helping the tumors to grow and metastasize. The molecular basis for the increase in the levels of this...diseases and also a pregnancy disorder known as preeclampsia . Polymorphisms in MTHFR that decrease the catalytic activity of the enzyme are common in the

Pigment epithelial-derived factor gene loaded novel COOH-PEG-PLGA-COOH nanoparticles promoted tumor suppression by systemic administration.

Science.gov (United States)

Yu, Ting; Xu, Bei; He, Lili; Xia, Shan; Chen, Yan; Zeng, Jun; Liu, Yongmei; Li, Shuangzhi; Tan, Xiaoyue; Ren, Ke; Yao, Shaohua; Song, Xiangrong

2016-01-01

Anti-angiogenesis has been proposed as an effective therapeutic strategy for cancer treatment. Pigment epithelium-derived factor (PEDF) is one of the most powerful endogenous anti-angiogenic reagents discovered to date and PEDF gene therapy has been recognized as a promising treatment option for various tumors. There is an urgent need to develop a safe and valid vector for its systemic delivery. Herein, a novel gene delivery system based on the newly synthesized copolymer COOH-PEG-PLGA-COOH (CPPC) was developed in this study, which was probably capable of overcoming the disadvantages of viral vectors and cationic lipids/polymers-based nonviral carriers. PEDF gene loaded CPPC nanoparticles (D-NPs) were fabricated by a modified double-emulsion water-in-oil-in-water (W/O/W) solvent evaporation method. D-NPs with uniform spherical shape had relatively high drug loading (~1.6%), probably because the introduced carboxyl group in poly (D,L-lactide-co-glycolide) terminal enhanced the interaction of copolymer with the PEDF gene complexes. An excellent in vitro antitumor effect was found in both C26 and A549 cells treated by D-NPs, in which PEDF levels were dramatically elevated due to the successful transfection of PEDF gene. D-NPs also showed a strong inhibitory effect on proliferation of human umbilical vein endothelial cells in vitro and inhibited the tumor-induced angiogenesis in vivo by an alginate-encapsulated tumor cell assay. Further in vivo antitumor investigation, carried out in a C26 subcutaneous tumor model by intravenous injection, demonstrated that D-NPs could achieve a significant antitumor activity with sharply reduced microvessel density and significantly promoted tumor cell apoptosis. Additionally, the in vitro hemolysis analysis and in vivo serological and biochemical analysis revealed that D-NPs had no obvious toxicity. All the data indicated that the novel CPPC nanoparticles were ideal vectors for the systemic delivery of PEDF gene and might be widely

Radiation activation of transcription factors in mammalian cells

International Nuclear Information System (INIS)

Kraemer, M.; Stein, B.; Mai, S.; Kunz, E.; Koenig, H.; Ponta, H.; Herrlich, P.; Rahmsdorf, H.J.; Loferer, H.; Grunicke, H.H.

1990-01-01

In mammalian cells radiation induces the enhanced transcription of several genes. The cis acting elements in the control region of inducible genes have been delimited by site directed mutagenesis. Several different elements have been found in different genes. They do not only activate gene transcription in response to radiation but also in response to growth factors and to tumor promoter phorbol esters. The transcription factors binding to these elements are present also in non-irradiated cells, but their DNA binding activity and their transactivating capability is increased upon irradiation. The signal chain linking the primary radiation induced signal (damaged DNA) to the activation of transcription factors involves the action of (a) protein kinase(s). (orig.)

Genomic loss of tumor suppressor miRNA-204 promotes cancer cell migration and invasion by activating AKT/mTOR/Rac1 signaling and actin reorganization.

Directory of Open Access Journals (Sweden)

J Saadi Imam

Full Text Available Increasing evidence suggests that chromosomal regions containing microRNAs are functionally important in cancers. Here, we show that genomic loci encoding miR-204 are frequently lost in multiple cancers, including ovarian cancers, pediatric renal tumors, and breast cancers. MiR-204 shows drastically reduced expression in several cancers and acts as a potent tumor suppressor, inhibiting tumor metastasis in vivo when systemically delivered. We demonstrated that miR-204 exerts its function by targeting genes involved in tumorigenesis including brain-derived neurotrophic factor (BDNF, a neurotrophin family member which is known to promote tumor angiogenesis and invasiveness. Analysis of primary tumors shows that increased expression of BDNF or its receptor tropomyosin-related kinase B (TrkB parallel a markedly reduced expression of miR-204. Our results reveal that loss of miR-204 results in BDNF overexpression and subsequent activation of the small GTPase Rac1 and actin reorganization through the AKT/mTOR signaling pathway leading to cancer cell migration and invasion. These results suggest that microdeletion of genomic loci containing miR-204 is directly linked with the deregulation of key oncogenic pathways that provide crucial stimulus for tumor growth and metastasis. Our findings provide a strong rationale for manipulating miR-204 levels therapeutically to suppress tumor metastasis.

Linkage mapping in the oilseed crop Jatropha curcas L. reveals a locus controlling the biosynthesis of phorbol esters which cause seed toxicity.

Science.gov (United States)

King, Andrew J; Montes, Luis R; Clarke, Jasper G; Affleck, Julie; Li, Yi; Witsenboer, Hanneke; van der Vossen, Edwin; van der Linde, Piet; Tripathi, Yogendra; Tavares, Evanilda; Shukla, Parul; Rajasekaran, Thirunavukkarasu; van Loo, Eibertus N; Graham, Ian A

2013-10-01

Current efforts to grow the tropical oilseed crop Jatropha curcas L. economically are hampered by the lack of cultivars and the presence of toxic phorbol esters (PE) within the seeds of most provenances. These PE restrict the conversion of seed cake into animal feed, although naturally occurring 'nontoxic' provenances exist which produce seed lacking PE. As an important step towards the development of genetically improved varieties of J. curcas, we constructed a linkage map from four F₂ mapping populations. The consensus linkage map contains 502 codominant markers, distributed over 11 linkage groups, with a mean marker density of 1.8 cM per unique locus. Analysis of the inheritance of PE biosynthesis indicated that this is a maternally controlled dominant monogenic trait. This maternal control is due to biosynthesis of the PE occurring only within maternal tissues. The trait segregated 3 : 1 within seeds collected from F₂ plants, and QTL analysis revealed that a locus on linkage group 8 was responsible for phorbol ester biosynthesis. By taking advantage of the draft genome assemblies of J. curcas and Ricinus communis (castor), a comparative mapping approach was used to develop additional markers to fine map this mutation within 2.3 cM. The linkage map provides a framework for the dissection of agronomic traits in J. curcas, and the development of improved varieties by marker-assisted breeding. The identification of the locus responsible for PE biosynthesis means that it is now possible to rapidly breed new nontoxic varieties. © 2013 The Authors. Plant Biotechnology Journal published by Society for Experimental Biology, Association of Applied Biologists and John Wiley & Sons Ltd.

Src Induces Podoplanin Expression to Promote Cell Migration*

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Shen, Yongquan; Chen, Chen-Shan; Ichikawa, Hitoshi; Goldberg, Gary S.

2010-01-01

Nontransformed cells can force tumor cells to assume a normal morphology and phenotype by the process of contact normalization. Transformed cells must escape this process to become invasive and malignant. However, mechanisms underlying contact normalization have not been elucidated. Here, we have identified genes that are affected by contact normalization of Src-transformed cells. Tumor cells must migrate to become invasive and malignant. Src must phosphorylate the adaptor protein Cas (Crk-associated substrate) to promote tumor cell motility. We report here that Src utilizes Cas to induce podoplanin (Pdpn) expression to promote tumor cell migration. Pdpn is a membrane-bound extracellular glycoprotein that associates with endogenous ligands to promote tumor cell migration leading to cancer invasion and metastasis. In fact, Pdpn expression accounted for a major part of the increased migration seen in Src-transformed cells. Moreover, nontransformed cells suppressed Pdpn expression in adjacent Src-transformed cells. Of >39,000 genes, Pdpn was one of only 23 genes found to be induced by transforming Src activity and suppressed by contact normalization of Src-transformed cells. In addition, we found 16 genes suppressed by Src and induced by contact normalization. These genes encode growth factor receptors, adaptor proteins, and products that have not yet been annotated and may play important roles in tumor cell growth and migration. PMID:20123990

mTOR at the Transmitting and Receiving Ends in Tumor Immunity

Directory of Open Access Journals (Sweden)

Yakir Guri

2018-03-01

Full Text Available Cancer is a complex disease and a leading cause of death worldwide. Immunity is critical for cancer control. Cancer cells exhibit high mutational rates and therefore altered self or neo-antigens, eliciting an immune response to promote tumor eradication. Failure to mount a proper immune response leads to cancer progression. mTOR signaling controls cellular metabolism, immune cell differentiation, and effector function. Deregulated mTOR signaling in cancer cells modulates the tumor microenvironment, thereby affecting tumor immunity and possibly promoting carcinogenesis.

High circulating levels of tumor necrosis factor-alpha in centenarians are not associated with increased production in T lymphocytes

DEFF Research Database (Denmark)

Sandmand, Marie; Bruunsgaard, Helle; Kemp, Kåre

2003-01-01

BACKGROUND: Aging is characterized by increased inflammatory activity reflected by increased plasma levels of proinflammatory cytokines, concomitant with an altered cytokine profile of T lymphocytes. High plasma levels of tumor necrosis factor (TNF)-alpha are strongly associated with morbidity...... and mortality in elderly humans. However, the cellular source and mechanisms for the increased circulating TNF-alpha levels are unknown. OBJECTIVE: The aim of the present study was to investigate if high plasma levels of TNF-alpha are associated with increased production of TNF-alpha by T lymphocytes in elderly...... humans. METHODS: TNF-alpha production by CD4+ and CD8+ T lymphocytes was measured by flow cytometry following stimulation with phorbol 12-myristate 13-acetate and ionomycin in 28 young controls, 14, 81-year-olds and 25 centenarians. RESULTS: Plasma levels of TNF-alpha increased with increasing age...

Macrophages support splenic erythropoiesis in 4T1 tumor-bearing mice.

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Min Liu

Full Text Available Anemia is a common complication of cancer; a role of spleen in tumor-stress erythropoiesis has been suggested. However, the molecular mechanisms involved in the splenic erythropoiesis following tumor maintenance remain poorly understood. Here we show that tumor development blocks medullar erythropoiesis by granulocyte colony-stimulating factor (G-CSF and then causes anemia in murine 4T1 breast tumor-bearing mice. Meanwhile, tumor-stress promotes splenic erythropoiesis. Splenectomy worsened tumor-induced anemia, and reduced tumor volume and tumor weight, indicating the essential role of spleen in tumor-stress erythropoiesis and tumor growth. Tumor progression of these mice led to increased amounts of bone morphogenetic protein 4 (BMP4 in spleen. The in vivo role of macrophages in splenic erythropoiesis under tumor-stress conditions was investigated. Macrophage depletion by injecting liposomal clodronate decreased the expression of BMP4, inhibited splenic erythropoiesis, aggravated the tumor-induced anemia and suppressed tumor growth. Our results provide insight that macrophages and BMP4 are positive regulators of splenic erythropoiesis in tumor pathological situations. These findings reveal that during the tumor-stress period, the microenvironment of the spleen is undergoing changes, which contributes to adopt a stress erythropoietic fate and supports the expansion and differentiation of stress erythroid progenitors, thereby replenishing red blood cells and promoting tumor growth.

Ha-ras oncogene expression directed by a milk protein gene promoter: tissue specificity, hormonal regulation, and tumor induction in transgenic mice

International Nuclear Information System (INIS)

Andres, A.C.; Schoenenberger, C.A.; Groner, B.; Henninghausen, L.; LeMeur, M.; Gelinger, P.

1987-01-01

The activated human Ha-ras oncogene was subjected to the control of the promoter region of the murine whey acidic protein (Wap) gene, which is expressed in mammary epithelial cells in response to lactogenic hormones. The Wap-ras gene was stably introduced into the mouse germ line of five transgenic mice (one male and four females). Wap-ras expression was observed in the mammary glands of lactating females in two lines derived from female founders. The tissue-directed and hormone-dependent Wap expression was conferred on the Ha-ras oncogene. The signals governing Wap expression are located within 2.5 kilobases of 5' flanking sequence. The other two lines derived from female founders did not express the chimeric gene. In the line derived from the male founder the Wap-ras gene is integrated into the Y chromosome. Expression was found in the salivary gland of male animals only. After a long latency, Wap-ras-expressing mice developed tumors. The tumors arose in tissues expressing Wap-ras - i.e., mammary or salivary glands. Compared to the corresponding nonmalignant tissues, Wap-ras expression was enhanced in the tumors

Multiple Myeloma Macrophages: Pivotal Players in the Tumor Microenvironment

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Simona Berardi

2013-01-01

Full Text Available Tumor microenvironment is essential for multiple myeloma (MM growth, progression, and drug resistance through provision of survival signals and secretion of growth and proangiogenic factors. This paper examines the importance of macrophages within MM bone marrow (BM microenvironment, referred to as MM-associated macrophages, as a potential niche component that supports tumor plasma cells. These macrophages are derived from peripheral blood monocytes recruited into the tumor. Upon activation by MM plasma cells and mesenchymal stromal cells, macrophages can release growth factors, proteolytic enzymes, cytokines, and inflammatory mediators that promote plasma cell growth and survival. Macrophages promote tumor progression through several mechanisms including angiogenesis, growth, and drug resistance. Indeed, these macrophages are essential for the induction of an angiogenic response through vasculogenic mimicry, and this ability proceeds in step with progression of the plasma cell tumors. Data suggest that macrophages play an important role in the biology and survival of patients with MM, and they may be a target for the MM antivascular management.

Canonical hedgehog signaling augments tumor angiogenesis by induction of VEGF-A in stromal perivascular cells

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Chen, Weiwei; Tang, Tracy; Eastham-Anderson, Jeff; Dunlap, Debra; Alicke, Bruno; Nannini, Michelle; Gould, Stephen; Yauch, Robert; Modrusan, Zora; DuPree, Kelly J.; Darbonne, Walter C.; Plowman, Greg; de Sauvage, Frederic J.; Callahan, Christopher A.

2011-01-01

Hedgehog (Hh) signaling is critical to the patterning and development of a variety of organ systems, and both ligand-dependent and ligand-independent Hh pathway activation are known to promote tumorigenesis. Recent studies have shown that in tumors promoted by Hh ligands, activation occurs within the stromal microenvironment. Testing whether ligand-driven Hh signaling promotes tumor angiogenesis, we found that Hh antagonism reduced the vascular density of Hh-producing LS180 and SW480 xenografts. In addition, ectopic expression of sonic hedgehog in low-Hh–expressing DLD-1 xenografts increased tumor vascular density, augmented angiogenesis, and was associated with canonical Hh signaling within perivascular tumor stromal cells. To better understand the molecular mechanisms underlying Hh-mediated tumor angiogenesis, we established an Hh-sensitive angiogenesis coculture assay and found that fibroblast cell lines derived from a variety of human tissues were Hh responsive and promoted angiogenesis in vitro through a secreted paracrine signal(s). Affymetrix array analyses of cultured fibroblasts identified VEGF-A, hepatocyte growth factor, and PDGF-C as candidate secreted proangiogenic factors induced by Hh stimulation. Expression studies of xenografts and angiogenesis assays using combinations of Hh and VEGF-A inhibitors showed that it is primarily Hh-induced VEGF-A that promotes angiogenesis in vitro and augments tumor-derived VEGF to promote angiogenesis in vivo. PMID:21597001

The inflammatory cytokine TNFα cooperates with Ras in elevating metastasis and turns WT-Ras to a tumor-promoting entity in MCF-7 cells

International Nuclear Information System (INIS)

Leibovich-Rivkin, Tal; Liubomirski, Yulia; Meshel, Tsipi; Abashidze, Anastasia; Brisker, Daphna; Solomon, Hilla; Rotter, Varda; Weil, Miguel; Ben-Baruch, Adit

2014-01-01

In the present study we determined the relative contribution of two processes to breast cancer progression: (1) Intrinsic events, such as activation of the Ras pathway and down-regulation of p53; (2) The inflammatory cytokines TNFα and IL-1β, shown in our published studies to be highly expressed in tumors of >80% of breast cancer patients with recurrent disease. Using MCF-7 human breast tumor cells originally expressing WT-Ras and WT-p53, we determined the impact of the above-mentioned elements and cooperativity between them on the expression of CXCL8 (ELISA, qRT-PCR), a member of a “cancer-related chemokine cluster” that we have previously identified. Then, we determined the mechanisms involved (Ras-binding-domain assays, Western blot, luciferase), and tested the impact of Ras + TNFα on angiogenicity (chorioallantoic membrane assays) and on tumor growth at the mammary fat pad of mice and on metastasis, in vivo. Using Ras G12V that recapitulates multiple stimulations induced by receptor tyrosine kinases, we found that Ras G12V alone induced CXCL8 expression at the mRNA and protein levels, whereas down-regulation of p53 did not. TNFα and IL-1β potently induced CXCL8 expression and synergized with Ras G12V , together leading to amplified CXCL8 expression. Testing the impact of WT-Ras, which is the common form in breast cancer patients, we found that WT-Ras was not active in promoting CXCL8; however, TNFα has induced the activation of WT-Ras: joining these two elements has led to cooperative induction of CXCL8 expression, via the activation of MEK, NF-κB and AP-1. Importantly, TNFα has led to increased expression of WT-Ras in an active GTP-bound form, with properties similar to those of Ras G12V . Jointly, TNFα + Ras activities have given rise to increased angiogenesis and to elevated tumor cell dissemination to lymph nodes. TNFα cooperates with Ras in promoting the metastatic phenotype of MCF-7 breast tumor cells, and turns WT-Ras into a tumor

LncRNA TUG1 acts as a tumor suppressor in human glioma by promoting cell apoptosis.

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Li, Jun; Zhang, Meng; An, Gang; Ma, Qingfang

2016-03-01

Previous studies have revealed multiple functional roles of long non-coding RNA taurine upregulated gene 1 in different types of malignant tumors, except for human glioma. Here, it was designed to study the potential function of taurine upregulated gene 1 in glioma pathogenesis focusing on its regulation on cell apoptosis. The expression of taurine upregulated gene 1 in glioma tissues was detected by quantitative RT-PCR and compared with that in adjacent normal tissues. Further correlation analysis was conducted to show the relationship between taurine upregulated gene 1 expression and different clinicopathologic parameters. Functional studies were performed to investigate the influence of taurine upregulated gene 1 on apoptosis and cell proliferation by using Annexin V/PI staining and cell counting kit-8 assays, respectively. And, caspase activation and Bcl-2 expression were analyzed to explore taurine upregulated gene 1-induced mechanism. taurine upregulated gene 1 expression was significantly inhibited in glioma and showed significant correlation with WHO Grade, tumor size and overall survival. Further experiments revealed that the dysregulation of taurine upregulated gene 1 affected the apoptosis and cell proliferation of glioma cells. Moreover, taurine upregulated gene 1 could induce the activation of caspase-3 and-9, with inhibited expression of Bcl-2, implying the mechanism in taurine upregulated gene 1-induced apoptosis. taurine upregulated gene 1 promoted cell apoptosis of glioma cells by activating caspase-3 and -9-mediated intrinsic pathways and inhibiting Bcl-2-mediated anti-apoptotic pathways, acting as a tumor suppressor in human glioma. This study provided new insights for the function of taurine upregulated gene 1 in cancer biology, and suggested a potent application of taurine upregulated gene 1 overexpression for glioma therapy. © 2016 by the Society for Experimental Biology and Medicine.

Characterization of the tumor-promoting activity of m-chloroperoxybenzoic acid in SENCAR mouse skin and its inhibition by gallotannin, oligomeric proanthocyanidin, and their monomeric units

Science.gov (United States)

Guilan Chen; Elisabeth M. Perchellet; Xiao Mei Gao; Fatima K. Johnson; Amy W. Davis; Steven W. Newell; Richard W. Hemingway; Vittorio Bottari; Jean-Pierre Perchellett

1996-01-01

m-Chloroperoxybenzoic acid (CPBA). Which induces ornithine decarboxylase activity as much as 12-0- terradecanoyIp horbol-13-acetate (TPA ). was tested for its ability to induce DNA synthesis. bydroperoxide (HPx) production. and tumor promotion in mouse epidermis in vivo. After an early inhibition. CPBA stimulates DNA synthesis. A response which is maintained between 16...

Optimization of conditions for the extraction of phorbol esters from Jatropha oil

Energy Technology Data Exchange (ETDEWEB)

Devappa, Rakshit K.; Makkar, H.P.S.; Becker, K. [Institute for Animal Production in the Tropics and Subtropics (480b), University of Hohenheim, 70593 Stuttgart (Germany)

2010-08-15

The production of Jatropha curcas seeds as a biodiesel feedstock is expected to reach 160 Mt by 2017. The present study aims at extracting phorbol esters (PEs) as a co-product from Jatropha oil before processing it to biodiesel. The conditions were optimized for extraction of PEs in organic solvents by using a magnetic stirrer and an Ultra turrax. The extent of reduction in PEs was >99.4% in methanol using any of the stirring tools. However, the extraction using Ultra turrax affected considerably the colour of the remaining oil. Therefore, further solvent:oil ratio, time and temperature were optimized using a magnetic stirrer to get PE rich fraction-I (48.4 mg PEs g{sup -1}) and virtually PE-free oil. PEs were 14 fold higher in this fraction than the control oil. PEs, extracted in methanol from the untreated Jatropha oil, at 1 mg L{sup -1} produced 100% mortality in snails (Physa fontinalis). The methanol extract from virtually PE-free oil when concentrated 20 and 25 time the untreated Jatropha oil (equivalent of 20 mg L{sup -1} and 25 mg L{sup -1} PEs in the control oil) was nontoxic to snails. PE rich fraction-I, obtained as a co-product, can be used in agricultural, medicinal and pharmaceutical applications and the remaining oil can be used for biodiesel preparation. The remaining oil will be friendly to the environment and workers. (author)

Tumor promoting properties of a cigarette smoke prevalent polycyclic aromatic hydrocarbon as indicated by the inhibition of gap junctional intercellular communication via phosphatidylcholine-specific phospholipase C

Czech Academy of Sciences Publication Activity Database

Upham, B. L.; Bláha, L.; Babica, P.; Park, J.-S.; Sovadinová, I.; Pudrith, Ch.; Rummel, A.M.; Weis, L.M.; Sai, K.; Tithof, P.K.; Gužvič, M.; Vondráček, Jan; Machala, M.; Trosko, J.E.

2008-01-01

Roč. 99, č. 4 (2008), s. 696-705 ISSN 1347-9032 R&D Projects: GA ČR(CZ) GA524/05/0595 Institutional research plan: CEZ:AV0Z50040507; CEZ:AV0Z50040702 Keywords : GJIC * phospholipases * tumor promotion Subject RIV: BO - Biophysics Impact factor: 3.471, year: 2008

IL-12 Expressing oncolytic herpes simplex virus promotes anti-tumor activity and immunologic control of metastatic ovarian cancer in mice.

Science.gov (United States)

Thomas, Eric D; Meza-Perez, Selene; Bevis, Kerri S; Randall, Troy D; Gillespie, G Yancey; Langford, Catherine; Alvarez, Ronald D

2016-10-27

sterile phosphate buffer solution. Our pilot study demonstrates that an interleukin-12-expressing oncolytic herpes simplex virus effectively kills both murine and human ovarian cancer cell lines and promotes tumor antigen-specific CD8 + T-cell responses in the peritoneal cavity and omentum, leading to reduced peritoneal metastasis and improved survival in a mouse model.

Tumor-induced loss of mural Connexin 43 gap junction activity promotes endothelial proliferation

International Nuclear Information System (INIS)

Choudhary, Mayur; Naczki, Christine; Chen, Wenhong; Barlow, Keith D.; Case, L. Douglas; Metheny-Barlow, Linda J.

2015-01-01

Proper functional association between mural cells and endothelial cells (EC) causes EC of blood vessels to become quiescent. Mural cells on tumor vessels exhibit decreased attachment to EC, which allows vessels to be unstable and proliferative. The mechanisms by which tumors prevent proper association between mural cells and EC are not well understood. Since gap junctions (GJ) play an important role in cell-cell contact and communication, we investigated whether loss of GJ plays a role in tumor-induced mural cell dissociation. Mural cell regulation of endothelial proliferation was assessed by direct co-culture assays of fluorescently labeled cells quantified by flow cytometry or plate reader. Gap junction function was assessed by parachute assay. Connexin 43 (Cx43) protein in mural cells exposed to conditioned media from cancer cells was assessed by Western and confocal microscopy; mRNA levels were assessed by quantitative real-time PCR. Expression vectors or siRNA were utilized to overexpress or knock down Cx43. Tumor growth and angiogenesis was assessed in mouse hosts deficient for Cx43. Using parachute dye transfer assay, we demonstrate that media conditioned by MDA-MB-231 breast cancer cells diminishes GJ communication between mural cells (vascular smooth muscle cells, vSMC) and EC. Both protein and mRNA of the GJ component Connexin 43 (Cx43) are downregulated in mural cells by tumor-conditioned media; media from non-tumorigenic MCF10A cells had no effect. Loss of GJ communication by Cx43 siRNA knockdown, treatment with blocking peptide, or exposure to tumor-conditioned media diminishes the ability of mural cells to inhibit EC proliferation in co-culture assays, while overexpression of Cx43 in vSMC restores GJ and endothelial inhibition. Breast tumor cells implanted into mice heterozygous for Cx43 show no changes in tumor growth, but exhibit significantly increased tumor vascularization determined by CD31 staining, along with decreased mural cell support

Distinct DNA Methylation Profiles in Ovarian Tumors: Opportunities for Novel Biomarkers

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Lorena Losi

2018-05-01

Full Text Available Aberrant methylation of multiple promoter CpG islands could be related to the biology of ovarian tumors and its determination could help to improve treatment strategies. DNA methylation profiling was performed using the Methylation Ligation-dependent Macroarray (MLM, an array-based analysis. Promoter regions of 41 genes were analyzed in 102 ovarian tumors and 17 normal ovarian samples. An average of 29% of hypermethylated promoter genes was observed in normal ovarian tissues. This percentage increased slightly in serous, endometrioid, and mucinous carcinomas (32%, 34%, and 45%, respectively, but decreased in germ cell tumors (20%. Ovarian tumors had methylation profiles that were more heterogeneous than other epithelial cancers. Unsupervised hierarchical clustering identified four groups that are very close to the histological subtypes of ovarian tumors. Aberrant methylation of three genes (BRCA1, MGMT, and MLH1, playing important roles in the different DNA repair mechanisms, were dependent on the tumor subtype and represent powerful biomarkers for precision therapy. Furthermore, a promising relationship between hypermethylation of MGMT, OSMR, ESR1, and FOXL2 and overall survival was observed. Our study of DNA methylation profiling indicates that the different histotypes of ovarian cancer should be treated as separate diseases both clinically and in research for the development of targeted therapies.

[Methylation of selected tumor-supressor genes in benign and malignant ovarian tumors].

Science.gov (United States)

Cul'bová, M; Lasabová, Z; Stanclová, A; Tilandyová, P; Zúbor, P; Fiolka, R; Danko, J; Visnovský, J

2011-09-01

To evaluate the usefullness of examination of methylation status of selected tumor-supressor genes in early diagnosis of ovarian cancer. Prospective clinical study. Department of Gynecology and Obstetrics, Department of Molecular Biology, Jessenius Medical Faculty, Commenius University, Martin, Slovak Republic. In this study we analyzed hypermethylation of 5 genes RASSF1A, GSTP, E-cadherin, p16 and APC in ovarian tumor samples from 34 patients - 13 patients with epithelial ovarian cancer, 2 patients with border-line ovarian tumors, 12 patients with benign lesions of ovaries and 7 patients with healthy ovarian tissue. The methylation status of promoter region of tumor-supressor genes was determined by Methylation Specific Polymerase Chain Reaction (MSP) using a nested two-step approach with bisulfite modified DNA template and specific primers. Gene methylation analysis revealed hypermethylation of gene RASSF1A (46%) and GSTP (8%) only in malignant ovarian tissue samples. Ecad, p16 and APC genes were methylated both in maignant and benign tissue samples. Methylation positivity in observed genes was present independently to all clinical stages of ovarian cancer and to tumor grades. However, there was observed a trend of increased number and selective involvement of methylated genes with increasing disease stages. Furthermore, there was no association between positive methylation status and histological subtypes of ovarian carcinomas. RASSF1A and GSTP promoter methylation positivity is associated with ovarian cancer. The revealed gene-selective methylation positivity and the increased number of methylated genes with advancing disease stages could be considered as a useful molecular marker for early detection of ovarian cancer. However, there is need to find diagnostic approach of specifically and frequently methylated genes to determining a methylation phenotype for early detection of ovarian malignancies.

Matrix metalloproteinase-10 promotes tumor progression through regulation of angiogenic and apoptotic pathways in cervical tumors

International Nuclear Information System (INIS)

Zhang, Ge; Miyake, Makito; Lawton, Adrienne; Goodison, Steve; Rosser, Charles J

2014-01-01

Cancer invasion and metastasis develops through a series of steps that involve the loss of cell to cell and cell to matrix adhesion, degradation of extracellular matrix and induction of angiogenesis. Different protease systems (e.g., matrix metalloproteinases, MMPs) are involved in these steps. MMP-10, one of the lesser studied MMPs, is limited to epithelial cells and can facilitate tumor cell invasion by targeting collagen, elastin and laminin. Enhanced MMP-10 expression has been linked to poor clinical prognosis in some cancers, however, mechanisms underlying a role for MMP-10 in tumorigenesis and progression remain largely unknown. Here, we report that MMP-10 expression is positively correlated with the invasiveness of human cervical and bladder cancers. Using commercial tissue microarray (TMA) of cervical and bladder tissues, MMP-10 immunohistochemical staining was performed. Furthermore using a panel of human cells (HeLa and UROtsa), in vitro and in vivo experiments were performed in which MMP-10 was overexpressed or silenced and we noted phenotypic and genotypic changes. Experimentally, we showed that MMP-10 can regulate tumor cell migration and invasion, and endothelial cell tube formation, and that MMP-10 effects are associated with a resistance to apoptosis. Further investigation revealed that increasing MMP-10 expression stimulates the expression of HIF-1α and MMP-2 (pro-angiogenic factors) and PAI-1 and CXCR2 (pro-metastatic factors), and accordingly, targeting MMP-10 with siRNA in vivo resulted in diminution of xenograft tumor growth with a concomitant reduction of angiogenesis and a stimulation of apoptosis. Taken together, our findings show that MMP-10 can play a significant role in tumor growth and progression, and that MMP-10 perturbation may represent a rational strategy for cancer treatment

Promoter Hypermethylation of the Eyes Absent 4 Gene is a Tumor-Specific Epigenetic Biomarker in Iranian Colorectal Cancer Patients

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Matineh Barati Bagerabad

2018-02-01

Full Text Available The aim of this study was to investigate whether hypermethylation of Eyes Absent 4 (EYA4 is also implicated in Iranian Colorectal Cancer (CRC patients or not. From fresh frozen tissues, samples from 38 paired (cancer and normal CRC tissue specimens were used in this study, the DNA was isolated, sodium bisulfite treated and analyzed by methylation-specific polymerase (MSP chain reaction using primers specific for unmethylated or methylated promoter sequences of the EYA4 gene. We also analyzed EYA4 mRNA expression using real time RT-PCR. Demographic characteristics of these patients including age, sex, tumor grade, location, stage, and TNM classification were evaluated and the relationship between methylation status of the gene and clinicopathological features was analyzed. Current study indicated that EYA4 promoter hypermethylation has a sensitivity of 81.57% and specificity of 78.94%. Findings showed lower expression of EYA-4 in methylated samples in comparison with its normal adjacent tissue, although it was not significant (P>0.05. No significant associations were observed between EYA4 hypermethylation and the clinicopathological characteristics. Although the clinical patient outcome of our 38 CRC patients was not associated with EYA4 promoter hypermethylation, the high frequency of this methylation and its high sensitivity and specificity to neoplastic cells may qualify EYA4 promoter methylation as a potential candidate screening marker in Iranian population and may help to improve early detection of CRC.

Hypoxic inactivation of glycogen synthase kinase-3β promotes gastric tumor growth and angiogenesis by facilitating hypoxia-inducible factor-1 signaling.

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Ko, Young San; Cho, Sung Jin; Park, Jinju; Choi, Yiseul; Lee, Jae-Seon; Youn, Hong-Duk; Kim, Woo Ho; Kim, Min A; Park, Jong-Wan; Lee, Byung Lan

2016-09-01

Since the molecular mechanism of hypoxic adaptation in cancer cells is cell-type specific, we investigated whether glycogen synthase kinase-3β (GSK-3β) activation is involved in hypoxia-induced gastric tumor promotion. Stable gastric cancer cell lines (SNU-638, SNU-484, MKN1, and MKN45) were cultured under hypoxic conditions. Cells overexpressing wild-type GSK-3β (WT-GSK-3β) or kinase-dead mutant of GSK-3β (KD-GSK-3β) were generated and used for cell culture and animal studies. In cell culture experiments, hypoxia decreased GSK-3β activation in gastric cancer cells. Cell viability and the expressions of HIF-1α protein and VEGF mRNA in gastric cancer cells were higher in KD-GSK-3β transfectants than in WT-GSK-3β transfectants under hypoxic conditions, but not under normoxic conditions. Gastric cancer xenografts showed that tumor growth, microvessel area, HIF-1α activation, and VEGF expression were higher in KD-GSK-3β tumors than in WT-GSK-3β tumors in vivo. In addition, the expression of hypoxia-induced HIF-1α protein was regulated by GSK-3β at the translational level. Our data suggest that GSK-3β is involved in hypoxic adaptation of gastric cancer cells as an inhibitory upstream regulator of the HIF-1α/VEGF signaling pathway. © 2016 APMIS. Published by John Wiley & Sons Ltd.

Promoter Hypermethylation of the ATM Gene as a Novel Biomarker for Breast Cancer

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Begam, Nasrin; Jamil, Kaiser; Raju, Suryanarayana G

2017-11-26

Background: Breast cancer may be induced by activation of protooncogenes to oncogenes and in many cases inactivation of tumor suppressor genes. Ataxia telangiectasia mutated (ATM) is an important tumor suppressor gene which plays central roles in the maintenance of genomic integrity by activating cell cycle checkpoints and promoting repair of double-strand breaks of DNA. In breast cancer, decrease ATM expression correlates with a poor outcome; however, the molecular mechanisms underlying downregulation are still unclear. Promoter hypermethylation may contribute in downregulation. Hence the present investigation was designed to evaluate promoter methylation and expression of the ATM gene in breast cancer cases, and to determine links with clinical and demographic manifestations, in a South Indian population. Methods: Tumor biopsy samples were collected from 50 pathologically confirmed sporadic breast cancer cases. DNA was isolated from tumor and adjacent non-tumorous regions, and sodium bisulfite conversion and methylation-specific PCR were performed using MS-PCR primers for the ATM promoter region. In addition, ATM mRNA expression was also analyzed for all samples using real-time PCR. Results: Fifty eight percent (58%) of cancer tissue samples showed promoter hypermethylation for the ATM gene, in contrast to only 4.44% of normal tissues (p= 0.0001). Furthermore, ATM promoter methylation was positively associated with age (p = 0.01), tumor size (p=0.045) and advanced stage of disease i.e. stages III and IV (p =0.019). An association between promoter hypermethylation and lower expression of ATM mRNA was also found (p=0.035). Conclusion: We report for the first time that promoter hypermethylation of ATM gene may be useful as a potential new biomarker for breast cancer, especially in the relatively young patients. Creative Commons Attribution License

Collaborative interplay between FGF-2 and VEGF-C promotes lymphangiogenesis and metastasis

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Cao, Renhai; Ji, Hong; Feng, Ninghan

2012-01-01

Interplay between various lymphangiogenic factors in promoting lymphangiogenesis and lymphatic metastasis remains poorly understood. Here we show that FGF-2 and VEGF-C, two lymphangiogenic factors, collaboratively promote angiogenesis and lymphangiogenesis in the tumor microenvironment, leading...... endothelial cell tip cell formation is a prerequisite for FGF-2-stimulated lymphangiogenesis. In the tumor microenvironment, the reciprocal interplay between FGF-2 and VEGF-C collaboratively stimulated tumor growth, angiogenesis, intratumoral lymphangiogenesis, and metastasis. Thus, intervention and targeting...

miR-19a promotes colitis-associated colorectal cancer by regulating tumor necrosis factor alpha-induced protein 3-NF-κB feedback loops.

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Wang, T; Xu, X; Xu, Q; Ren, J; Shen, S; Fan, C; Hou, Y

2017-06-08

Chronic inflammation is believed to have a crucial role in colon cancer development. MicroRNA (miRNA) deregulation is common in human colorectal cancers, but little is known regarding whether miRNA drives tumor progression by regulating inflammation. Here, we showed that miR-19a can promote colitis and colitis-associated colon cancer (CAC) development using a CAC mouse model and an acute colitis mouse model. Tumor necrosis factor-α (TNF-α) stimulation can increase miR-19a expression, and upregulated miR-19a can in turn activate nuclear factor (NF)-κB signaling and TNF-α production by targeting TNF alpha-induced protein 3 (TNFAIP3). miR-19a inhibition can also alleviate CAC in vivo. Moreover, the regulatory effects of miR-19a on TNFAIP3 and NF-κB signaling were confirmed using tumor samples from patients with colon cancer. These new findings demonstrate that miR-19a has a direct role in upregulating NF-κB signaling and that miR-19a has roles in inflammation and CAC.

Interaction of tumor cells with the microenvironment

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Lehnert Hendrik

2011-09-01

Full Text Available Abstract Recent advances in tumor biology have revealed that a detailed analysis of the complex interactions of tumor cells with their adjacent microenvironment (tumor stroma is mandatory in order to understand the various mechanisms involved in tumor growth and the development of metastasis. The mutual interactions between tumor cells and cellular and non-cellular components (extracellular matrix = ECM of the tumor microenvironment will eventually lead to a loss of tissue homeostasis and promote tumor development and progression. Thus, interactions of genetically altered tumor cells and the ECM on the one hand and reactive non-neoplastic cells on the other hand essentially control most aspects of tumorigenesis such as epithelial-mesenchymal-transition (EMT, migration, invasion (i.e. migration through connective tissue, metastasis formation, neovascularisation, apoptosis and chemotherapeutic drug resistance. In this mini-review we will focus on these issues that were recently raised by two review articles in CCS.

Tumor associated macrophages protect colon cancer cells from TRAIL-induced apoptosis through IL-1beta-dependent stabilization of Snail in tumor cells.

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Pawan Kaler

2010-07-01

Full Text Available We recently reported that colon tumor cells stimulate macrophages to release IL-1beta, which in turn inactivates GSK3beta and enhances Wnt signaling in colon cancer cells, generating a self-amplifying loop that promotes the growth of tumor cells.Here we describe that macrophages protect HCT116 and Hke-3 colon cancer cells from TRAIL-induced apoptosis. Inactivation of IL-1beta by neutralizing IL-1beta antibody, or silencing of IL-1beta in macrophages inhibited their ability to counter TRAIL-induced apoptosis. Accordingly, IL-1beta was sufficient to inhibit TRAIL-induced apoptosis. TRAIL-induced collapse of the mitochondrial membrane potential (Delta psi and activation of caspases were prevented by macrophages or by recombinant IL-1beta. Pharmacological inhibition of IL-1beta release from macrophages by vitamin D(3, a potent chemopreventive agent for colorectal cancer, restored the ability of TRAIL to induce apoptosis of tumor cells cultured with macrophages. Macrophages and IL-1beta failed to inhibit TRAIL-induced apoptosis in HCT116 cells expressing dnIkappaB, dnAKT or dnTCF4, confirming that they oppose TRAIL-induced cell death through induction of Wnt signaling in tumor cells. We showed that macrophages and IL-1beta stabilized Snail in tumor cells in an NF-kappaB/Wnt dependent manner and that Snail deficient tumor cells were not protected from TRAIL-induced apoptosis by macrophages or by IL-1beta, demonstrating a crucial role of Snail in the resistance of tumor cells to TRAIL.We have identified a positive feedback loop between tumor cells and macrophages that propagates the growth and promotes the survival of colon cancer cells: tumor cells stimulate macrophages to secrete IL-1beta, which in turn, promotes Wnt signaling and stabilizes Snail in tumor cells, conferring resistance to TRAIL. Vitamin D(3 halts this amplifying loop by interfering with the release of IL-1beta from macrophages. Accordingly, vitamin D(3 sensitizes tumor cells to TRAIL

Virus vector-mediated genetic modification of brain tumor stromal cells after intravenous delivery.

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Volak, Adrienn; LeRoy, Stanley G; Natasan, Jeya Shree; Park, David J; Cheah, Pike See; Maus, Andreas; Fitzpatrick, Zachary; Hudry, Eloise; Pinkham, Kelsey; Gandhi, Sheetal; Hyman, Bradley T; Mu, Dakai; GuhaSarkar, Dwijit; Stemmer-Rachamimov, Anat O; Sena-Esteves, Miguel; Badr, Christian E; Maguire, Casey A

2018-05-16

The malignant primary brain tumor, glioblastoma (GBM) is generally incurable. New approaches are desperately needed. Adeno-associated virus (AAV) vector-mediated delivery of anti-tumor transgenes is a promising strategy, however direct injection leads to focal transgene spread in tumor and rapid tumor division dilutes out the extra-chromosomal AAV genome, limiting duration of transgene expression. Intravenous (IV) injection gives widespread distribution of AAV in normal brain, however poor transgene expression in tumor, and high expression in non-target cells which may lead to ineffective therapy and high toxicity, respectively. Delivery of transgenes encoding secreted, anti-tumor proteins to tumor stromal cells may provide a more stable and localized reservoir of therapy as they are more differentiated than fast-dividing tumor cells. Reactive astrocytes and tumor-associated macrophage/microglia (TAMs) are stromal cells that comprise a large portion of the tumor mass and are associated with tumorigenesis. In mouse models of GBM, we used IV delivery of exosome-associated AAV vectors driving green fluorescent protein expression by specific promoters (NF-κB-responsive promoter and a truncated glial fibrillary acidic protein promoter), to obtain targeted transduction of TAMs and reactive astrocytes, respectively, while avoiding transgene expression in the periphery. We used our approach to express the potent, yet toxic anti-tumor cytokine, interferon beta, in tumor stroma of a mouse model of GBM, and achieved a modest, yet significant enhancement in survival compared to controls. Noninvasive genetic modification of tumor microenvironment represents a promising approach for therapy against cancers. Additionally, the vectors described here may facilitate basic research in the study of tumor stromal cells in situ.

APC promoter is frequently methylated in pancreatic juice of patients with pancreatic carcinomas or periampullary tumors.

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Ginesta, Mireia M; Diaz-Riascos, Zamira Vanessa; Busquets, Juli; Pelaez, Núria; Serrano, Teresa; Peinado, Miquel Àngel; Jorba, Rosa; García-Borobia, Francisco Javier; Capella, Gabriel; Fabregat, Joan

2016-09-01

Early detection of pancreatic and periampullary neoplasms is critical to improve their clinical outcome. The present authors previously demonstrated that DNA hypermethylation of adenomatous polyposis coli (APC), histamine receptor H2 (HRH2), cadherin 13 (CDH13), secreted protein acidic and cysteine rich (SPARC) and engrailed-1 (EN-1) promoters is frequently detected in pancreatic tumor cells. The aim of the present study was to assess their prevalence in pancreatic juice of carcinomas of the pancreas and periampullary area. A total of 135 pancreatic juices obtained from 85 pancreatic cancer (PC), 26 ampullary carcinoma (AC), 10 intraductal papillary mucinous neoplasm (IPMN) and 14 chronic pancreatitis (CP) patients were analyzed. The methylation status of the APC, HRH2, CDH13, SPARC and EN-1 promoters was analyzed using methylation specific-melting curve analysis (MS-MCA). Kirsten rat sarcoma viral oncogene homolog (KRAS) mutations were also tested with allele-specific quantitative polymerase chain reaction amplification. Out of the 5 promoters analyzed, APC (71%) and HRH2 (65%) were the most frequently methylated in PC juice. APC methylation was also detected at a high frequency in AC (76%) and IPMN (80%), but only occasionally observed in CP (7%). APC methylation had a high sensitivity (71-80%) for all types of cancer analyzed. The panel (where a sample scored as positive when ≥2 markers were methylated) did not outperform APC as a single marker. Finally, KRAS detection in pancreatic juice offered a lower sensitivity (50%) and specificity (71%) for detection of any cancer. APC hypermethylation in pancreatic juice, as assessed by MS-MCA, is a frequent event of potential clinical usefulness in the diagnosis of pancreatic and periampullary neoplasms.

Nuclear proteins interacting with the promoter region of the human granulocyte/macrophage colony-stimulating factor gene

International Nuclear Information System (INIS)

Shannon, M.F.; Gamble, J.R.; Vadas, M.A.

1988-01-01

The gene for human granulocyte/macrophage colony-stimulating factor (GM-CSF) is expressed in a tissue-specific as well as an activation-dependent manner. The interaction of nuclear proteins with the promoter region of the GM-CSF gene that is likely to be responsible for this pattern of GM-CSF expression was investigated. The authors show that nuclear proteins interact with DNA fragments from the GM-CSF promoter in a cell-specific manner. A region spanning two cytokine-specific sequences, cytokine 1 (CK-1, 5', GAGATTCCAC 3') and cytokine 2 (CK-2, 5' TCAGGTA 3') bound two nuclear proteins from GM-CSF-expressing cells in gel retardation assays. NF-GMb was inducible with phorbol 12-myristate 13-acetate and accompanied induction of GM-CSF message. NF-GMb was absent in cell lines not producing GM-CSF, some of which had other distinct binding proteins. NF-GMa and NF-GMb eluted from a heparin-Sepharose column at 0.3 and 0.6 M KCl, respectively. They hypothesize that the sequences CK-1 and CK-2 bind specific proteins and regulate GM-CSF transcription

Inflammasomes and Cancer: The Dynamic Role of the Inflammasome in Tumor Development

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Melvin Kantono

2017-09-01

Full Text Available Chronic Inflammation in tumor microenvironments is not only associated with various stages of tumor development, but also has significant impacts on tumor immunity and immunotherapy. Inflammasome are an important innate immune pathway critical for the production of active IL-1β and interleukin 18, as well as the induction of pyroptosis. Although extensive studies have demonstrated that inflammasomes play a vital role in infectious and autoimmune diseases, their role in tumor progression remains elusive. Multiple studies using a colitis-associated colon cancer model show that inflammasome components provide protection against the development of colon cancer. However, very recent studies demonstrate that inflammasomes promote tumor progression in skin and breast cancer. These results indicate that inflammasomes can promote and suppress tumor development depending on types of tumors, specific inflammasomes involved, and downstream effector molecules. The complicated role of inflammasomes raises new opportunities and challenges to manipulate inflammasome pathways in the treatment of cancer.

CTHRC1 Acts as a Prognostic Factor and Promotes Invasiveness of Gastrointestinal Stromal Tumors by Activating Wnt/PCP-Rho Signaling

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Ming-Ze Ma

2014-03-01

Full Text Available Gastrointestinal stromal tumors (GISTs are the major gastrointestinal mesenchymal tumors with a variable malignancy ranging from a curable disorder to highly malignant sarcomas. Metastasis and recurrence are the main causes of death in GIST patients. To further explore the mechanism of metastasis and to more accurately estimate the recurrence risk of GISTs after surgery, the clinical significance and functional role of collagen triple helix repeat containing-1 (CTHRC1 in GIST were investigated. We found that CTHRC1 expression was gradually elevated as the risk grade of NIH classification increased, and was closely correlated with disease-free survival and overall survival in 412 GIST patients. In vitro experiments showed that recombinant CTHRC1 protein promoted the migration and invasion capacities of primary GIST cells. A luciferase reporter assay and pull down assay demonstrated that recombinant CTHRC1 protein activated noncanonical Wnt/PCP-Rho signaling but inhibited canonical Wnt signaling. The pro-motility effect of CTHRC1 on GIST cells was reversed by using a Wnt5a neutralizing antibody and inhibitors of Rac1 or ROCK. Taken together, these data indicate that CTHRC1 may serve as a new predictor of recurrence risk and prognosis in post-operative GIST patients and may play an important role in facilitating GIST progression. Furthermore, CTHRC1 promotes GIST cell migration and invasion by activating Wnt/PCP-Rho signaling, suggesting that the CTHRC1-Wnt/PCP-Rho axis may be a new therapeutic target for interventions against GIST invasion and metastasis.

The “Trojan Horse” Approach to Tumor Immunotherapy: Targeting the Tumor Microenvironment

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Delia Nelson

2014-01-01

Full Text Available Most anticancer therapies including immunotherapies are given systemically; yet therapies given directly into tumors may be more effective, particularly those that overcome natural suppressive factors in the tumor microenvironment. The “Trojan Horse” approach of intratumoural delivery aims to promote immune-mediated destruction by inducing microenvironmental changes within the tumour at the same time as avoiding the systemic toxicity that is often associated with more “full frontal” treatments such as transfer of large numbers of laboratory-expanded tumor-specific cytotoxic T lymphocytes or large intravenous doses of cytokine. Numerous studies have demonstrated that intratumoural therapy has the capacity to minimizing local suppression, inducing sufficient “dangerous” tumor cell death to cross-prime strong immune responses, and rending tumor blood vessels amenable to immune cell traffic to induce effector cell changes in secondary lymphoid organs. However, the key to its success is the design of a sound rational approach based on evidence. There is compelling preclinical data for local immunotherapy approaches in tumor immunology. This review summarises how immune events within a tumour can be modified by local approaches, how this can affect systemic antitumor immunity such that distal sites are attacked, and what approaches have been proven most successful so far in animals and patients.

FOXA1 promotes tumor cell proliferation through AR involving the Notch pathway in endometrial cancer

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Qiu, Meiting; Bao, Wei; Wang, Jingyun; Yang, Tingting; He, Xiaoying; Liao, Yun; Wan, Xiaoping

2014-01-01

Increasing evidence suggests that forkhead box A1 (FOXA1) is frequently dysregulated in many types of human cancers. However, the exact function and mechanism of FOXA1 in human endometrial cancer (EC) remains unclear. FOXA1 expression, androgen receptor (AR) expression, and the relationships of these two markers with clinicopathological factors were determined by immunohistochemistry analysis. FOXA1 and AR were up-regulated by transient transfection with plasmids, and were down-regulated by transfection with siRNA or short hairpin RNA (shRNA). The effects of FOXA1 depletion and FOXA1 overexpression on AR-mediated transcription as well as Notch pathway and their impact on EC cell proliferation were examined by qRT-PCR, western blotting, co-immunoprecipitation, ChIP-PCR, MTT, colony-formation, and xenograft tumor–formation assays. We found that the expression of FOXA1 and AR in ECs was significantly higher than that in a typical hyperplasia and normal tissues. FOXA1 expression was significantly correlated with AR expression in clinical tissues. High FOXA1 levels positively correlated with pathological grade and depth of myometrial invasion in EC. High AR levels also positively correlated with pathological grade in EC. Moreover, the expression of XBP1, MYC, ZBTB16, and UHRF1, which are downstream targets of AR, was promoted by FOXA1 up-regulation or inhibited by FOXA1 down-regulation. Co-immunoprecipitation showed that FOXA1 interacted with AR in EC cells. ChIP-PCR assays showed that FOXA1 and AR could directly bind to the promoter and enhancer regions upstream of MYC. Mechanistic investigation revealed that over-expression of Notch1 and Hes1 proteins by FOXA1 could be reversed by AR depletion. In addition, we showed that down-regulation of AR attenuated FOXA1-up-regulated cell proliferation. However, AR didn’t influence the promotion effect of FOXA1 on cell migration and invasion. In vivo xenograft model, FOXA1 knockdown reduced the rate of tumor growth. These

miRNA let-7b modulates macrophage polarization and enhances tumor-associated macrophages to promote angiogenesis and mobility in prostate cancer.

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Wang, Zhigang; Xu, Lu; Hu, Yinying; Huang, Yanqin; Zhang, Yujuan; Zheng, Xiufen; Wang, Shanshan; Wang, Yifan; Yu, Yanrong; Zhang, Meng; Yuan, Keng; Min, Weiping

2016-05-09

Macrophage polarization is a highly plastic physiological process that responds to a variety of environmental factors by changing macrophage phenotype and function. Tumor-associated macrophages (TAMs) are generally recognized as promoting tumor progression. As universal regulators, microRNAs (miRNAs) are functionally involved in numerous critical cellular processes including macrophage polarization. Let-7b, a miRNA, has differential expression patterns in inflamed tissues compared with healthy controls. However, whether and how miRNA let-7b regulates macrophage phenotype and function is unclear. In this report, we find that up-regulation of let-7b is characteristic of prostatic TAMs, and down-regulation of let-7b in TAMs leads to changes in expression profiles of inflammatory cytokines, such as IL-12, IL-23, IL-10 and TNF-α. As a result, TAMs treated with let-7b inhibitors reduce angiogenesis and prostate carcinoma (PCa) cell mobility. Let-7b may play a vital role in regulating macrophage polarization, thus modulating the prognosis of prostate cancer.

Targeting tumor-associated macrophages by anti-tumor Chinese materia medica.

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Pu, Wei-Ling; Sun, Li-Kang; Gao, Xiu-Mei; Rüegg, Curzio; Cuendet, Muriel; Hottiger, Micheal O; Zhou, Kun; Miao, Lin; Zhang, Yun-Sha; Gebauer, Margaret

2017-10-01

Tumor-associated macrophages (TAMs) play a key role in all stages of tumorigenesis and tumor progression. TAMs secrete different kinds of cytokines, chemokines, and enzymes to affect the progression, metastasis, and resistance to therapy depending on their state of reprogramming. Therapeutic benefit in targeting TAMs suggests that macrophages are attractive targets for cancer treatment. Chinese materia medica (CMM) is an important approach for treating cancer in China and in the Asian region. According to the theory of Chinese medicine (CM) and its practice, some prescriptions of CM regulate the body's internal environment possibly including the remodeling the tumor microenvironment (TME). Here we briefly summarize the pivotal effects of TAMs in shaping the TME and promoting tumorigenesis, invasion, metastasis and immunosuppression. Furthermore, we illustrate the effects and mechanisms of CMM targeting TAMs in antitumor therapy. Finally, we reveal the CMM's dual-regulatory and multi-targeting functions on regulating TAMs, and hopefully, provide the theoretical basis for CMM clinical practice related to cancer therapy.

Modifiers of free radicals inhibit in vitro the oncogenic actions of x-rays, bleomycin, and the tumor promoter 12-O-tetradecanoylphorbol 13-acetate

International Nuclear Information System (INIS)

Borek, C.; Troll, W.

1983-01-01

Using short-term cultures of hamster embryo cells, we have examined the effects of the free-radical scavenger superoxide dismutase (superoxide:superoxide oxidoreductase, EC 1.15.1.1) and the enzyme catalase (hydrogen-peroxide:hydrogen-peroxide oxidoreductase, EC 1.11.1.6) on x-ray-and bleomycin-induced transformation and on the enhancement of radiogenic transformation by the tumor promoter 12-O-tetradecanoylphorbol 13-acetate (TPA). We find that superoxide dismutase inhibits (i) transformation induced by x-ray and bleomycin and (ii) promotional action of TPA in vitro. The results suggest that the oncogenic action of x-rays and bleomycin and the enhancement of oncogenic transformation by TPA are mediated in part by free radicals. The findings also suggest that superoxide dismutase can serve as an inhibitor of oncogenesis and that its actions, as seen in this in vitro system, are most predominantly on inhibiting late events in the progression of cellular transformation--those associated with promotion

Methylation screening of the TGFBI promoter in human lung and prostate cancer by methylation-specific PCR

International Nuclear Information System (INIS)

Shah, Jinesh N; Shao, Genze; Hei, Tom K; Zhao, Yongliang

2008-01-01

Hypermethylation of the TGFBI promoter has been shown to correlate with decreased expression of this gene in human tumor cell lines. In this study, we optimized a methylation-specific polymerase chain reaction (MSP) method and investigated the methylation status of the TGFBI promoter in human lung and prostate cancer specimens. Methylation-specific primers were designed based on the methylation profiles of the TGFBI promoter in human tumor cell lines, and MSP conditions were optimized for accurate and efficient amplification. Genomic DNA was isolated from lung tumors and prostatectomy tissues of prostate cancer patients, bisulfite-converted, and analyzed by MSP. Among 50 lung cancer samples, 44.0% (22/50) harbored methylated CpG sites in the TGFBI promoter. An analysis correlating gene methylation status with clinicopathological cancer features revealed that dense methylation of the TGFBI promoter was associated with a metastatic phenotype, with 42.9% (6/14) of metastatic lung cancer samples demonstrating dense methylation vs. only 5.6% (2/36) of primary lung cancer samples (p < 0.05). Similar to these lung cancer results, 82.0% (41/50) of prostate cancer samples harbored methylated CpG sites in the TGFBI promoter, and dense methylation of the promoter was present in 38.9% (7/18) of prostate cancer samples with the feature of locoregional invasiveness vs. only 19.4% (6/31) of prostate cancer samples without locoregional invasiveness (p < 0.05). Furthermore, promoter hypermethylation correlated with highly reduced expression of the TGFBI gene in human lung and prostate tumor cell lines. We successfully optimized a MSP method for the precise and efficient screening of TGFBI promoter methylation status. Dense methylation of the TGFBI promoter correlated with the extent of TGFBI gene silencing in tumor cell lines and was related to invasiveness of prostate tumors and metastatic status of lung cancer tumors. Thus, TGFBI promoter methylation can be used as a potential

A Bayesian statistical analysis of mouse dermal tumor promotion assay data for evaluating cigarette smoke condensate.

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Kathman, Steven J; Potts, Ryan J; Ayres, Paul H; Harp, Paul R; Wilson, Cody L; Garner, Charles D

2010-10-01

The mouse dermal assay has long been used to assess the dermal tumorigenicity of cigarette smoke condensate (CSC). This mouse skin model has been developed for use in carcinogenicity testing utilizing the SENCAR mouse as the standard strain. Though the model has limitations, it remains as the most relevant method available to study the dermal tumor promoting potential of mainstream cigarette smoke. In the typical SENCAR mouse CSC bioassay, CSC is applied for 29 weeks following the application of a tumor initiator such as 7,12-dimethylbenz[a]anthracene (DMBA). Several endpoints are considered for analysis including: the percentage of animals with at least one mass, latency, and number of masses per animal. In this paper, a relatively straightforward analytic model and procedure is presented for analyzing the time course of the incidence of masses. The procedure considered here takes advantage of Bayesian statistical techniques, which provide powerful methods for model fitting and simulation. Two datasets are analyzed to illustrate how the model fits the data, how well the model may perform in predicting data from such trials, and how the model may be used as a decision tool when comparing the dermal tumorigenicity of cigarette smoke condensate from multiple cigarette types. The analysis presented here was developed as a statistical decision tool for differentiating between two or more prototype products based on the dermal tumorigenicity. Copyright (c) 2010 Elsevier Inc. All rights reserved.

Genetic polymorphisms within tumor necrosis factor gene promoter region: a role for susceptibility to ventilator-associated pneumonia.

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Kotsaki, Antigoni; Raftogiannis, Maria; Routsi, Christina; Baziaka, Fotini; Kotanidou, Anastasia; Antonopoulou, Anastasia; Orfanos, Stylianos E; Katsenos, Chrisostomos; Koutoukas, Pantelis; Plachouras, Diamantis; Mandragos, Konstantinos; Giamarellos-Bourboulis, Evangelos J

2012-08-01

Debatable findings exist among various studies regarding the impact of single nucleotide polymorphisms (SNPs) within the promoter region of the tumor necrosis factor (TNF) gene for susceptibility to infections. Their impact was investigated in a cohort of mechanically ventilated patients who developed ventilator-associated pneumonia (VAP). Two-hundred and thirteen mechanically ventilated patients who developed VAP were enrolled. Genomic DNA was extracted and SNPs at the -376, -308 and -238 position of the promoter region of the TNF gene were assessed by restriction fragment length polymorphisms. Monocytes were isolated from 47 patients when they developed sepsis and stimulated by bacterial endotoxin for the production of TNFα and of interleukin-6 (IL-6). Patients were divided into two groups; 166 patients bearing only wild-type alleles of all three studied polymorphisms; and 47 patients carrying at least one A allele of the three studied SNPs. Time between start of mechanical ventilation and advent of VAP was significantly shorter in the second group than in the first group (log-rank: 4.416, p: 0.041). When VAP supervened, disease severity did not differ between groups. Stimulation of TNFα and of IL-6 was much greater by monocytes for patients carrying A alleles. Carriage of at least one A allele of the three studied SNPs at the promoter region of the TNF-gene is associated with shorter time to development of VAP but it is not associated with disease severity. Findings may be related with a role of the studied SNPs in the production of pro-inflammatory cytokines. Copyright © 2012 Elsevier Ltd. All rights reserved.

Extracellular signal regulated kinase 5 mediates signals triggered by the novel tumor promoter palytoxin

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Charlson, Aaron T.; Zeliadt, Nicholette A.; Wattenberg, Elizabeth V.

2009-01-01

Palytoxin is classified as a non-12-O-tetradecanoylphorbol-13-acetate (TPA)-type skin tumor because it does not bind to or activate protein kinase C. Palytoxin is thus a novel tool for investigating alternative signaling pathways that may affect carcinogenesis. We previously showed that palytoxin activates three major members of the mitogen activated protein kinase (MAPK) family, extracellular signal regulated kinase 1 and 2 (ERK1/2), c-Jun N-terminal kinase (JNK), and p38. Here we report that palytoxin also activates another MAPK family member, called ERK5, in HeLa cells and in keratinocytes derived from initiated mouse skin (308 cells). By contrast, TPA does not activate ERK5 in these cell lines. The major cell surface receptor for palytoxin is the Na+,K+-ATPase. Accordingly, ouabain blocked the ability of palytoxin to activate ERK5. Ouabain alone did not activate ERK5. ERK5 thus represents a divergence in the signaling pathways activated by these two agents that bind to the Na+,K+-ATPase. Cycloheximide, okadaic acid, and sodium orthovanadate did not mimic the effect of palytoxin on ERK5. These results indicate that the stimulation of ERK5 by palytoxin is not simply due to inhibition of protein synthesis or inhibition of serine/threonine or tyrosine phosphatases. Therefore, the mechanism by which palytoxin activates ERK5 differs from that by which it activates ERK1/2, JNK, and p38. Finally, studies that used pharmacological inhibitors and shRNA to block ERK5 action indicate that ERK5 contributes to palytoxin-stimulated c-Fos gene expression. These results suggest that ERK5 can act as an alternative mediator for transmitting diverse tumor promoter-stimulated signals.

A Genomics Approach to Tumor Gemome Analysis

National Research Council Canada - National Science Library

Collins, Colin

2002-01-01

Genomes of solid tumors are often highly rearranged and these rearrangements promote cancer progression through disruption of genes mediating immortality, survival, metastasis, and resistance to therapy...

The host immunological response to cancer therapy: An emerging concept in tumor biology

International Nuclear Information System (INIS)

Voloshin, Tali; Voest, Emile E.; Shaked, Yuval

2013-01-01

Almost any type of anti-cancer treatment including chemotherapy, radiation, surgery and targeted drugs can induce host molecular and cellular immunological effects which, in turn, can lead to tumor outgrowth and relapse despite an initial successful therapy outcome. Tumor relapse due to host immunological effects is attributed to angiogenesis, tumor cell dissemination from the primary tumors and seeding at metastatic sites. This short review will describe the types of host cells that participate in this process, the types of factors secreted from the host following therapy that can promote tumor re-growth, and the possible implications of this unique and yet only partially-known process. It is postulated that blocking these specific immunological effects in the reactive host in response to cancer therapy may aid in identifying new host-dependent targets for cancer, which in combination with conventional treatments can prolong therapy efficacy and extend survival. Additional studies investigating this specific research direction—both in preclinical models and in the clinical setting are essential in order to advance our understanding of how tumors relapse and evade therapy. -- Highlights: • Cancer therapy induces host molecular and cellular pro-tumorigenic effects. • Host effects in response to therapy may promote tumor relapse and metastasis. • The reactive host consists of immunological mediators promoting tumor re-growth. • Blocking therapy-induced host mediators may improve outcome

The host immunological response to cancer therapy: An emerging concept in tumor biology

Energy Technology Data Exchange (ETDEWEB)

Voloshin, Tali [Department of Molecular Pharmacology, Rappaport Faculty of Medicine and the Rappaport Institute, Technion—Israel Institute of Technology, 1 Efron Street, Bat Galim, Haifa 31096 (Israel); Voest, Emile E. [Department of Medical Oncology, University Medical Center Utrecht, Utrecht (Netherlands); Shaked, Yuval, E-mail: yshaked@tx.technion.ac.il [Department of Molecular Pharmacology, Rappaport Faculty of Medicine and the Rappaport Institute, Technion—Israel Institute of Technology, 1 Efron Street, Bat Galim, Haifa 31096 (Israel)

2013-07-01

Almost any type of anti-cancer treatment including chemotherapy, radiation, surgery and targeted drugs can induce host molecular and cellular immunological effects which, in turn, can lead to tumor outgrowth and relapse despite an initial successful therapy outcome. Tumor relapse due to host immunological effects is attributed to angiogenesis, tumor cell dissemination from the primary tumors and seeding at metastatic sites. This short review will describe the types of host cells that participate in this process, the types of factors secreted from the host following therapy that can promote tumor re-growth, and the possible implications of this unique and yet only partially-known process. It is postulated that blocking these specific immunological effects in the reactive host in response to cancer therapy may aid in identifying new host-dependent targets for cancer, which in combination with conventional treatments can prolong therapy efficacy and extend survival. Additional studies investigating this specific research direction—both in preclinical models and in the clinical setting are essential in order to advance our understanding of how tumors relapse and evade therapy. -- Highlights: • Cancer therapy induces host molecular and cellular pro-tumorigenic effects. • Host effects in response to therapy may promote tumor relapse and metastasis. • The reactive host consists of immunological mediators promoting tumor re-growth. • Blocking therapy-induced host mediators may improve outcome.

Fibroblast-derived CXCL12 promotes breast cancer metastasis by facilitating tumor cell intravasation.

Science.gov (United States)

Ahirwar, Dinesh K; Nasser, Mohd W; Ouseph, Madhu M; Elbaz, Mohamad; Cuitiño, Maria C; Kladney, Raleigh D; Varikuti, Sanjay; Kaul, Kirti; Satoskar, Abhay R; Ramaswamy, Bhuvaneswari; Zhang, Xiaoli; Ostrowski, Michael C; Leone, Gustavo; Ganju, Ramesh K

2018-05-03

The chemokine CXCL12 has been shown to regulate breast tumor growth, however, its mechanism in initiating distant metastasis is not well understood. Here, we generated a novel conditional allele of Cxcl12 in mice and used a fibroblast-specific Cre transgene along with various mammary tumor models to evaluate CXCL12 function in the breast cancer metastasis. Ablation of CXCL12 in stromal fibroblasts of mice significantly delayed the time to tumor onset and inhibited distant metastasis in different mouse models. Elucidation of mechanisms using in vitro and in vivo model systems revealed that CXCL12 enhances tumor cell intravasation by increasing vascular permeability and expansion of a leaky tumor vasculature. Furthermore, our studies revealed CXCL12 enhances permeability by recruiting endothelial precursor cells and decreasing endothelial tight junction and adherence junction proteins. High expression of stromal CXCL12 in large cohort of breast cancer patients was directly correlated to blood vessel density and inversely correlated to recurrence and overall patient survival. In addition, our analysis revealed that stromal CXCL12 levels in combination with number of CD31+ blood vessels confers poorer patient survival compared to individual protein level. However, no correlation was observed between epithelial CXCL12 and patient survival or blood vessel density. Our findings describe the novel interactions between fibroblasts-derived CXCL12 and endothelial cells in facilitating tumor cell intrvasation, leading to distant metastasis. Overall, our studies indicate that cross-talk between fibroblast-derived CXCL12 and endothelial cells could be used as novel biomarker and strategy for developing tumor microenvironment based therapies against aggressive and metastatic breast cancer.

Tumor suppression effects of bilberry extracts and enzymatically modified isoquercitrin in early preneoplastic liver cell lesions induced by piperonyl butoxide promotion in a two-stage rat hepatocarcinogenesis model.

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Hara, Shintaro; Morita, Reiko; Ogawa, Takashi; Segawa, Risa; Takimoto, Norifumi; Suzuki, Kazuhiko; Hamadate, Naobumi; Hayashi, Shim-Mo; Odachi, Ayano; Ogiwara, Isao; Shibusawa, Sakae; Yoshida, Toshinori; Shibutani, Makoto

2014-08-01

To investigate the protective effect of bilberry extracts (BBE) and enzymatically modified isoquercitrin (EMIQ) on the hepatocarcinogenic process involving oxidative stress responses, we used a two-stage hepatocarcinogenesis model in N-diethylnitrosamine-initiated and piperonyl butoxide (PBO)-promoted rats. We examined the modifying effect of co-administration with BBE or EMIQ on the liver tissue environment including oxidative stress responses, cell proliferation and apoptosis, and phosphatase and tensin homolog (PTEN)/Akt and transforming growth factor (TGF)-β/Smad signalings on the induction mechanism of preneoplastic lesions during early stages of hepatocellular tumor promotion. PBO increased the numbers and area of glutathione S-transferase placental form (GST-P)(+) liver cell foci and the numbers of Ki-67(+) proliferating cells within GST-P(+) foci. Co-administration of BBE or EMIQ suppressed these effects with the reductions of GST-P(+) foci (area) to 48.9-49.4% and Ki-67(+) cells to 55.5-61.4% of the PBO-promoted cases. Neither BBE nor EMIQ decreased microsomal reactive oxygen species induced by PBO. However, only EMIQ suppressed the level of thiobarbituric acid-reactive substances to 78.4% of the PBO-promoted cases. PBO increased the incidences of phospho-PTEN(-) foci, phospho-Akt substrate(+) foci, phospho-Smad3(-) foci and Smad4(-) foci in GST-P(+) foci. Both BBE and EMIQ decreased the incidences of phospho-PTEN(-) foci in GST-P(+) foci to 59.8-72.2% and Smad4(-) foci to 62.4-71.5% of the PBO-promoted cases, and BBE also suppressed the incidence of phospho-Akt substrate(+) foci in GST-P(+) foci to 75.2-75.7% of the PBO-promoted cases. These results suggest that PBO-induced tumor promotion involves facilitation of PTEN/Akt and disruptive TGF-β/Smad signalings without relation to oxidative stress responses, but this promotion was suppressed by co-treatment with BBE or EMIQ through suppression of cell proliferation activity of preneoplastic liver cells

Molecular cloning of a human glycophorin B cDNA: nucleotide sequence and genomic relationship to glycophorin A

International Nuclear Information System (INIS)

Siebert, P.D.; Fukuda, M.

1987-01-01

The authors describe the isolation and nucleotide sequence of a human glycophorin B cDNA. The cDNA was identified by differential hybridization of synthetic oligonucleotide probes to a human erythroleukemic cell line (K562) cDNA library constructed in phage vector λgt10. The nucleotide sequence of the glycophorin B cDNA was compared with that of a previously cloned glycophorin A cDNA. The nucleotide sequences encoding the NH 2 -terminal leader peptide and first 26 amino acids of the two proteins are nearly identical. This homologous region is followed by areas specific to either glycophorin A or B and a number of small regions of homology, which in turn are followed by a very homologous region encoding the presumed membrane-spanning portion of the proteins. They used RNA blot hybridization with both cDNA and synthetic oligonucleotide probes to prove our previous hypothesis that glycophorin B is encoded by a single 0.5- to 0.6-kb mRNA and to show that glycophorins A and B are negatively and coordinately regulated by a tumor-promoting phorbol ester, phorbol 12-myristate 13-acetate. They established the intron/exon structure of the glycophorin A and B genes by oligonucleotide mapping; the results suggest a complex evolution of the glycophorin genes

Synthetic Nanoparticles That Promote Tumor Necrosis Factor Receptor 2 Expressing Regulatory T Cells in the Lung and Resistance to Allergic Airways Inflammation

Directory of Open Access Journals (Sweden)

Rohimah Mohamud

2017-12-01

Full Text Available Synthetic glycine coated 50 nm polystyrene nanoparticles (NP (PS50G, unlike ambient NP, do not promote pulmonary inflammation, but instead, render lungs resistant to the development of allergic airway inflammation. In this study, we show that PS50G modulate the frequency and phenotype of regulatory T cells (Treg in the lung, specifically increasing the proportion of tumor necrosis factor 2 (TNFR2 expressing Treg. Mice pre-exposed to PS50G, which were sensitized and then challenged with an allergen a month later, preferentially expanded TNFR2+Foxp3+ Treg, which further expressed enhanced levels of latency associated peptide and cytotoxic T-lymphocyte associated molecule-4. Moreover, PS50G-induced CD103+ dendritic cell activation in the lung was associated with the proliferative expansion of TNFR2+Foxp3+ Treg. These findings provide the first evidence that engineered NP can promote the selective expansion of maximally suppressing TNFR2+Foxp3+ Treg and further suggest a novel mechanism by which NP may promote healthy lung homeostasis.

Osteotoxicity after chronic dietary administration of 13-CIS-retinoic acid, retinyl palmitate or selenium in mice exposed to tumor initiation and promotion

International Nuclear Information System (INIS)

Forsyth, K.S.; Gensler, H.L.; Watson, R.R.

1989-01-01

In view of the clinical trials of retinoids as therapeutic agents for premalignant skin lesions, a radiographic study was undertaken to measure skeletal toxicities after chronic dietary administration of retinoids in mice exposed to tumor initiation and promotion. CD-1 mice were initiated with 0.15 moles of 7,12-dimethylbenz[a]anthracene and promoted twice daily with 8 nmoles of 12-O-tetradecanoylphorbol-13-acetate for 23 weeks. Diets were supplemented with 60 IU, 200 IU, or 700 IU or retinyl palmitate (RP) per g diet. After 5 weeks, the 700 IU of RP/g diet was lowered to 350 IU/g diet. Administration of these diets to mice during the 23 weeks of tumor promotion results in a 0-fold, 2-fold, or 10-fold increase in bone fractures, respectively. Osteoporotic bone lesions identified on radiographs rose 0-fold, 0-fold, and 10-fold at the respective doses, whereas metaphyseal flares increased O-fold, 1.4-fold, and 3.6-fold. Bone deformities was augmented O-fold, 1.8-fold and 2.9-fold at the respective doses. Addition of selenium did not alter the bone toxicity of RP. 13-cis-retionic acid (CRA) was less toxic at 700 IU/g diet than was RP at that dose, as evidence by the death of 12 of 70 mice by the 6th week of dietary RP and no deaths in the 35 mice fed 700 IU CRA/g diet for 23 weeks. CRA at 700 IU/g diet resulted in 3/4 as many osteoporotic bones, 1/3 as many bone fractures, 4/5 as many metaphyseal flares, and a similar number of bone deformities as mice fed 700/350 IU/g diet. At the dose of 200 IU/g food, osterotoxicities were similar in the mice fed diets supplemented with RP and CRA

Promoter Methylation Analysis of IDH Genes in Human Gliomas

International Nuclear Information System (INIS)

Flanagan, Simon; Lee, Maggie; Li, Cheryl C. Y.; Suter, Catherine M.; Buckland, Michael E.

2012-01-01

Mutations in isocitrate dehydrogenase (IDH)-1 or -2 are found in the majority of WHO grade II and III astrocytomas and oligodendrogliomas, and secondary glioblastomas. Almost all described mutations are heterozygous missense mutations affecting a conserved arginine residue in the substrate binding site of IDH1 (R132) or IDH2 (R172). But the exact mechanism of IDH mutations in neoplasia is not understood. It has been proposed that IDH mutations impart a “toxic gain-of-function” to the mutant protein, however a dominant-negative effect of mutant IDH has also been described, implying that IDH may function as a tumor suppressor gene. As most, if not all, tumor suppressor genes are inactivated by epigenetic silencing, in a wide variety of tumors, we asked if IDH1 or IDH2 carry the epigenetic signature of a tumor suppressor by assessing cytosine methylation at their promoters. Methylation was quantified in 68 human brain tumors, including both IDH-mutant and IDH wildtype, by bisulfite pyrosequencing. In all tumors examined, CpG methylation levels were less than 8%. Our data demonstrate that inactivation of IDH function through promoter hypermethylation is not common in human gliomas and other brain tumors. These findings do not support a tumor suppressor role for IDH genes in human gliomas.

Co-ordinate expression of activin A and its type I receptor mRNAs during phorbol ester-induced differentiation of human K562 erythroleukemia cells.

Science.gov (United States)

Hildén, K; Tuuri, T; Erämaa, M; Ritvos, O

1999-07-20

Activins were originally isolated based on their ability to stimulate follicle-stimulating hormone secretion but later they have been shown to regulate a number of different cellular functions such as nerve cell survival, mesoderm induction during early embryogenesis as well as hematopoiesis. We studied the regulation of activin A, a homodimer of betaA-subunits, mRNA and protein in K562 erythroleukemia cells, which are known to be induced toward the erythroid lineage in response to activin or TGF-beta or toward the megakaryocytic lineage by the phorbol ester protein kinase C activator 12-O-tetradecanoylphorbol-13-acetate (TPA). Here we show by Northern blot analysis as well as by Western and ligand blotting that TPA strongly promotes activin betaA-subunit mRNA and activin A protein expression in K562 cells in time- and concentration dependent manner. In contrast, neither activin A nor TGF-beta induced betaA-subunit mRNA expression during erythroid differentiation in K562 cells. Interestingly, whereas activin type II receptors are not regulated during K562 cell differentiation (Hilden et al. (1994) Blood 83, 2163-2170), we now show that the activin type I and IB receptor mRNAs are clearly induced by TPA but not by activin or TGF-beta. We also show that the inducing effect of TPA on expression of activin betaA-subunit mRNA is potentiated by the protein kinase A activator 8-bromo-cAMP. We conclude that activin A and its type I receptors appear to be co-ordinately up-regulated during megakaryocytic differentiation of K562 cells.

Drainage alone or combined with anti-tumor therapy for treatment of obstructive jaundice caused by recurrence and metastasis after primary tumor resection.

Science.gov (United States)

Xu, Chuan; Huang, Xin-En; Wang, Shu-Xiang; Lv, Peng-Hua; Sun, Ling; Wang, Fu-An; Wang, Li-Fu

2014-01-01

To compare drainage alone or combined with anti-tumor therapy for treatment of obstructive jaundice caused by recurrence and metastasis after primary tumor resection. We collect 42 patients with obstructive jaundice caused by recurrence and metastasis after tumor resection from January 2008 - August 2012, for which percutaneous transhepatic catheter drainage (pTCD)/ percutaneous transhepatic biliary stenting (pTBS) were performed. In 25 patients drainage was combined with anti-tumor treatment, antineoplastic therapy including intra/postprodure local treatment and postoperative systemic chemotherapy, the other 17 undergoing drainage only. We assessed the two kinds of treatment with regard to patient prognosis. Both treatments demonstrated good effects in reducing bilirubin levels in the short term and promoting liver function. The time to reobstruction was 125 days in the combined group and 89 days in the drainage only group; the mean survival times were 185 and 128 days, the differences being significant. Interventional drainage in the treatment of the obstructive jaundice caused by recurrence and metastasis after tumor resection can decrease bilirubin level quickly in a short term and promote the liver function recovery. Combined treatment prolongs the survival time and period before reobstruction as compared to drainage only.

Metastasis-inducing S100A4 and RANTES cooperate in promoting tumor progression in mice.

Directory of Open Access Journals (Sweden)

Birgitte Forst

2010-04-01

Full Text Available The tumor microenvironment has been described as a critical milieu determining tumor growth and metastases. A pivotal role of metastasis-inducing S100A4 in the development of tumor stroma has been proven in animal models and verified in human breast cancer biopsies. Expression and release of S100A4 has been shown in various types of stroma composing cells, including fibroblasts and immune cells. However, the events implicated in upstream and downstream pathways regulating the activity of the extracellular S100A4 protein in the tumor milieu remain unsolved.We studied the interplay between the tumor cell-derived cytokine regulated-upon-activation, normal T-cell expressed and secreted (RANTES; CCL5 and S100A4 which were shown to be critical factors in tumor progression. We found that RANTES stimulates the externalization of S100A4 via microparticle shedding from the plasma membrane of tumor and stroma cells. Conversely, the released S100A4 protein induces the upregulation of fibronectin (FN in fibroblasts and a number of cytokines, including RANTES in tumor cells as well as stimulates cell motility in a wound healing assay. Importantly, using wild type and S100A4-deficient mouse models, we demonstrated a substantial influence of tumor cell-derived RANTES on S100A4 release into blood circulation which ultimately increases the metastatic burden in mice.Altogether, the data presented strongly validate the pro-metastatic function of S100A4 in the tumor microenvironment and define how the tumor cell-derived cytokine RANTES acts as a critical regulator of S100A4-dependent tumor cell dissemination. Additionally, for the first time we demonstrated the mechanism of S100A4 release associated with plasma membrane microparticle shedding from various cells types.

Intratumoral macrophages contribute to epithelial-mesenchymal transition in solid tumors

International Nuclear Information System (INIS)

Bonde, Anne-Katrine; Tischler, Verena; Kumar, Sushil; Soltermann, Alex; Schwendener, Reto A

2012-01-01

Several stromal cell subtypes including macrophages contribute to tumor progression by inducing epithelial-mesenchymal transition (EMT) at the invasive front, a mechanism also linked to metastasis. Tumor associated macrophages (TAM) reside mainly at the invasive front but they also infiltrate tumors and in this process they mainly assume a tumor promoting phenotype. In this study, we asked if TAMs also regulate EMT intratumorally. We found that TAMs through TGF-β signaling and activation of the β-catenin pathway can induce EMT in intratumoral cancer cells. We depleted macrophages in F9-teratocarcinoma bearing mice using clodronate-liposomes and analyzed the tumors for correlations between gene and protein expression of EMT-associated and macrophage markers. The functional relationship between TAMs and EMT was characterized in vitro in the murine F9 and mammary gland NMuMG cells, using a conditioned medium culture approach. The clinical relevance of our findings was evaluated on a tissue microarray cohort representing 491 patients with non-small cell lung cancer (NSCLC). Gene expression analysis of F9-teratocarcinomas revealed a positive correlation between TAM-densities and mesenchymal marker expression. Moreover, immunohistochemistry showed that TAMs cluster with EMT phenotype cells in the tumors. In vitro, long term exposure of F9-and NMuMG-cells to macrophage-conditioned medium led to decreased expression of the epithelial adhesion protein E-cadherin, activation of the EMT-mediating β-catenin pathway, increased expression of mesenchymal markers and an invasive phenotype. In a candidate based screen, macrophage-derived TGF-β was identified as the main inducer of this EMT-associated phenotype. Lastly, immunohistochemical analysis of NSCLC patient samples identified a positive correlation between intratumoral macrophage densities, EMT markers, intraepithelial TGF-β levels and tumor grade. Data presented here identify a novel role for macrophages in EMT-promoted

The hTERT promoter enhances the antitumor activity of an oncolytic adenovirus under a hypoxic microenvironment.

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Yuuri Hashimoto

Full Text Available Hypoxia is a microenvironmental factor that contributes to the invasion, progression and metastasis of tumor cells. Hypoxic tumor cells often show more resistance to conventional chemoradiotherapy than normoxic tumor cells, suggesting the requirement of novel antitumor therapies to efficiently eliminate the hypoxic tumor cells. We previously generated a tumor-specific replication-competent oncolytic adenovirus (OBP-301: Telomelysin, in which the human telomerase reverse transcriptase (hTERT promoter drives viral E1 expression. Since the promoter activity of the hTERT gene has been shown to be upregulated by hypoxia, we hypothesized that, under hypoxic conditions, the antitumor effect of OBP-301 with the hTERT promoter would be more efficient than that of the wild-type adenovirus 5 (Ad5. In this study, we investigated the antitumor effects of OBP-301 and Ad5 against human cancer cells under a normoxic (20% oxygen or a hypoxic (1% oxygen condition. Hypoxic condition induced nuclear accumulation of the hypoxia-inducible factor-1α and upregulation of hTERT promoter activity in human cancer cells. The cytopathic activity of OBP-301 was significantly higher than that of Ad5 under hypoxic condition. Consistent with their cytopathic activity, the replication of OBP-301 was significantly higher than that of Ad5 under the hypoxic condition. OBP-301-mediated E1A was expressed within hypoxic areas of human xenograft tumors in mice. These results suggest that the cytopathic activity of OBP-301 against hypoxic tumor cells is mediated through hypoxia-mediated activation of the hTERT promoter. Regulation of oncolytic adenoviruses by the hTERT promoter is a promising antitumor strategy, not only for induction of tumor-specific oncolysis, but also for efficient elimination of hypoxic tumor cells.

Role of arachidonic acid metabolism in transcriptional induction of tumor necrosis factor gene expression by phorbol ester

Energy Technology Data Exchange (ETDEWEB)

Horiguchi, J.; Spriggs, D.; Imamura, K.; Stone, R.; Luebbers, R.; Kufe, D.

1989-01-01

The treatment of human HL-60 promyelocytic leukemia cells with 12-0 tetradecanoylphorbol-13-acetate (TPA) is associated with induction of tumor necrosis factor (TNF) transcripts. The study reported here has examined TPA-induced signaling mechanisms responsible for the regulation of TNF gene expression in these cells. Run-on assays demonstrated that TPA increases TNS mRNA levels by transcriptional activation of this gene. The induction of TNF transcripts by TPA was inhibited by the isoquinolinesulfonamide derivative H7 but not by HA1004, suggesting that this effect of TPA is mediated by activation of protein kinase C. TPA treatment also resulted in increased arachidonic acid release. Moreover, inhibitors of phospholipase, A/sub 2/ blocked both the increase in arachidonic acid release and the induction of TNF transcripts. These findings suggest that TPA induces TNF gene expression through the formation of arachidonic acid metabolites. Although indomethacin had no detectable effect on this induction of TNF transcripts, ketoconazole, an inhibitor of 5-lipoxygenase, blocked TPA-induced increases in TNF mRNA levels. Moreover, TNF mRNA levels were increased by the 5-lipoxygenase metabolite leukotriene B/sub 4/. In contrast, the cyclooxygenase metabolite prostaglandin E/sub 2/ inhibited the induction of TNF transcripts by TPA. Taken together, these results suggest that TPA induces TNF gene expression through the arachidonic acid cascade and that the level of TNF transcripts is regulated by metabolites of the pathway, leukotriene B/sub 4/ and prostaglandin E/sub 2/.

Vav promotes differentiation of human tumoral myeloid precursors

International Nuclear Information System (INIS)

Bertagnolo, Valeria; Brugnoli, Federica; Mischiati, Carlo; Sereni, Alessia; Bavelloni, Alberto; Carini, Cinzia; Capitani, Silvano

2005-01-01

Vav is one of the genetic markers that correlate with the differentiation of hematopoietic cells. In T and B cells, it appears crucial for both development and functions, while, in non-lymphoid hematopoietic cells, Vav seems not involved in cell maturation, but rather in the response of mature cells to agonist-dependent proliferation and phagocytosis. We have previously demonstrated that the amount and the tyrosine phosphorylation of Vav are up-regulated in both whole cells and nuclei of tumoral promyelocytes induced to granulocytic maturation by ATRA and that tyrosine-phosphorylated Vav does not display any ATRA-induced GEF activity but contributes to the regulation of PI 3-K activity. In this study, we report that Vav accumulates in nuclei of ATRA-treated APL-derived cells and that the down-modulation of Vav prevents differentiation of tumoral promyelocytes, indicating that it is a key molecule in ATRA-dependent myeloid maturation. On the other hand, the overexpression of Vav induces an increased expression of surface markers of granulocytic differentiation without affecting the maturation-related changes of the nuclear morphology. Consistent with an effect of Vav on the transcriptional machinery, array profiling shows that the inhibition of the Syk-dependent tyrosine phosphorylation of Vav reduces the number of ATRA-induced genes. Our data support the unprecedented notion that Vav plays crucial functions in the maturation process of myeloid cells, and suggest that Vav can be regarded as a potential target for the therapeutic treatment of myeloproliferative disorders

Extratumoral Heme Oxygenase-1 (HO-1 Expressing Macrophages Likely Promote Primary and Metastatic Prostate Tumor Growth.

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Sofia Halin Bergström

Full Text Available Aggressive tumors induce tumor-supporting changes in the benign parts of the prostate. One factor that has increased expression outside prostate tumors is hemoxygenase-1 (HO-1. To investigate HO-1 expression in more detail, we analyzed samples of tumor tissue and peritumoral normal prostate tissue from rats carrying cancers with different metastatic capacity, and human prostate cancer tissue samples from primary tumors and bone metastases. In rat prostate tumor samples, immunohistochemistry and quantitative RT-PCR showed that the main site of HO-1 synthesis was HO-1+ macrophages that accumulated in the tumor-bearing organ, and at the tumor-invasive front. Small metastatic tumors were considerably more effective in attracting HO-1+ macrophages than larger non-metastatic ones. In clinical samples, accumulation of HO-1+ macrophages was seen at the tumor invasive front, almost exclusively in high-grade tumors, and it correlated with the presence of bone metastases. HO-1+ macrophages, located at the tumor invasive front, were more abundant in bone metastases than in primary tumors. HO-1 expression in bone metastases was variable, and positively correlated with the expression of macrophage markers but negatively correlated with androgen receptor expression, suggesting that elevated HO-1 could be a marker for a subgroup of bone metastases. Together with another recent observation showing that selective knockout of HO-1 in macrophages reduced prostate tumor growth and metastatic capacity in animals, the results of this study suggest that extratumoral HO-1+ macrophages may have an important role in prostate cancer.

Extracellular vesicles as shuttles of tumor biomarkers and anti-tumor drugs.

Science.gov (United States)

Zocco, Davide; Ferruzzi, Pietro; Cappello, Francesco; Kuo, Winston Patrick; Fais, Stefano

2014-01-01

Extracellular vesicles (EV) include vesicles released by either normal or tumor cells. EV may exceed the nanometric scale (microvesicles), or to be within the nanoscale, also called exosomes. Thus, it appears that only exosomes and larger vesicles may have the size for potential applications in nanomedicine, in either disease diagnosis or therapy. This is of particular interest for research in cancer, also because the vast majority of existing data on EV are coming from pre-clinical and clinical oncology. We know that the microenvironmental features of cancer may favor cell-to-cell paracrine communication through EV, but EV have been purified, characterized, and quantified from plasma of tumor patients as well, thus suggesting that EV may have a role in promoting and maintaining cancer dissemination and progression. These observations are prompting research efforts to evaluate the use of nanovesicles as tumor biomarkers. Moreover, EVs are emerging as natural delivery systems and in particular, exosomes may represent the ideal natural nanoshuttles for new and old anti-tumor drugs. However, much is yet to be understood about the role of EV in oncology and this article aims to discuss the future of EV in cancer on the basis of current knowledge.

CD44 antibody stimulates adhesion of peripheral blood T cells to keratinocytes through the leukocyte function-associated antigen-1/intercellular adhesion molecule-1 pathway

NARCIS (Netherlands)

Bruynzeel, I.; Koopman, G.; van der Raaij, L. M.; Pals, S. T.; Willemze, R.

1993-01-01

Close contact between T lymphocytes and keratinocytes is an important feature of many inflammatory skin diseases. In vitro studies showed that stimulation of keratinocytes with interferon-gamma or tumor necrosis factor-alpha and of T cells with phorbol esters results in a leukocyte

Evaluation of uptake and distribution of gold nanoparticles in solid tumors

Science.gov (United States)

England, Christopheri G.; Gobin, André M.; Frieboes, Hermann B.

2015-11-01

Although nanotherapeutics offer a targeted and potentially less toxic alternative to systemic chemotherapy in cancer treatment, nanotherapeutic transport is typically hindered by abnormal characteristics of tumor tissue. Once nanoparticles targeted to tumor cells arrive in the circulation of tumor vasculature, they must extravasate from irregular vessels and diffuse through the tissue to ideally reach all malignant cells in cytotoxic concentrations. The enhanced permeability and retention effect can be leveraged to promote extravasation of appropriately sized particles from tumor vasculature; however, therapeutic success remains elusive partly due to inadequate intra-tumoral transport promoting heterogeneous nanoparticle uptake and distribution. Irregular tumor vasculature not only hinders particle transport but also sustains hypoxic tissue kregions with quiescent cells, which may be unaffected by cycle-dependent chemotherapeutics released from nanoparticles and thus regrow tumor tissue following nanotherapy. Furthermore, a large proportion of systemically injected nanoparticles may become sequestered by the reticulo-endothelial system, resulting in overall diminished efficacy. We review recent work evaluating the uptake and distribution of gold nanoparticles in pre-clinical tumor models, with the goal to help improve nanotherapy outcomes. We also examine the potential role of novel layered gold nanoparticles designed to address some of these critical issues, assessing their uptake and transport in cancerous tissue.

Rapid isolation and purification of phorbol esters from Jatropha curcas by high-speed countercurrent chromatography.

Science.gov (United States)

Hua, Wan; Hu, Huiling; Chen, Fang; Tang, Lin; Peng, Tong; Wang, Zhanguo

2015-03-18

In this work, a high-speed countercurrent chromatography (HSCCC) method was established for the preparation of phorbol esters (PEs) from Jatropha curcas. n-Hexane-ethyl acetate-methanol-water (1.5:1.5:1.2:0.5, v/v) was selected as the optimum two-phase solvent system to separate and purify jatropha factor C1 (JC1) with a purity of 85.2%, as determined by HPLC, and to obtain a mixture containing four or five PEs. Subsequently, continuous semipreparative HPLC was applied to further purify JC1 (99.8% as determined by HPLC). In addition, UPLC-PDA and UPLC-MS were established and successfully used to evaluate the isolated JC1 and PE-rich crude extract. The purity of JC1 was only 87.8% by UPLC-UV. A peak (a compound highly similar to JC1) was indentified as the isomer of JC1 by comparing the characteristic UV absorption and MS spectra. Meanwhile, this strategy was also applied to analyze the PE-rich crude extract from J. curcas. It is interesting that there may be more than 15 PEs according to the same quasi-molecular ion peaks, highly similar sequence-specific fragment ions, and similar UV absorption spectrum.

Cancer Stem Cell Plasticity as Tumor Growth Promoter and Catalyst of Population Collapse

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Jan Poleszczuk

2016-01-01

Full Text Available It is increasingly argued that cancer stem cells are not a cellular phenotype but rather a transient state that cells can acquire, either through intrinsic signaling cascades or in response to environmental cues. While cancer stem cell plasticity is generally associated with increased aggressiveness and treatment resistance, we set out to thoroughly investigate the impact of different rates of plasticity on early and late tumor growth dynamics and the response to therapy. We develop an agent-based model of cancer stem cell driven tumor growth, in which plasticity is defined as a spontaneous transition between stem and nonstem cancer cell states. Simulations of the model show that plasticity can substantially increase tumor growth rate and invasion. At high rates of plasticity, however, the cells get exhausted and the tumor will undergo spontaneous remission in the long term. In a series of in silico trials, we show that such remission can be facilitated through radiotherapy. The presented study suggests that stem cell plasticity has rather complex, nonintuitive implications on tumor growth and treatment response. Further theoretical, experimental, and integrated studies are needed to fully decipher cancer stem cell plasticity and how it can be harnessed for novel therapeutic approaches.

Dangerous Liaisons: Deviant Endothelium NOTCHes toward Tumor Metastasis.

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Guo, Peipei; Rafii, Shahin

2017-03-13

In this issue of Cancer Cell, Wieland et al. uncover a feedback loop in which tumor cells, by augmenting Notch signaling, provoke a senescent and pro-inflammatory state in endothelial cells, promoting neutrophil infiltration, tumor cell adhesion, and metastasis. Interfering with this Notch-dependent crosstalk may be a therapeutic approach to block metastasis. Copyright © 2017 Elsevier Inc. All rights reserved.

Transcriptional Inhibition of Matrix Metal loproteinase 9 (MMP-9 Activity by a c-fos/Estrogen Receptor Fusion Protein is Mediated by the Proximal AP-1 Site of the MMP-9 Promoter and Correlates with Reduced Tumor Cell Invasion

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David L. Crowe

1999-10-01

Full Text Available Tumor cell invasion of basement membranes is one of the hallmarks of malignant transformation. Tumor cells secrete proteolytic enzymes known as matrix metalloproteinases (MMPs which degrade extracellular matrix molecules. Increased expression of MMP-9 has been associated with acquisition of invasive phenotype in many tumors. However, multiple mechanisms for regulation of MMP-9 gene expression by tumor cell lines have been proposed. A number of transcription factor binding sites have been characterized in the upstream regulatory region of the MMP-9 gene, including those for AP-1. To determine how a specific AP-1 family member, c-fos, regulates MMP-9 promoter activity through these sites, we used an expression vector containing the c-fos coding region fused to the estrogen receptor (ER ligand binding domain. This construct is activated upon binding estradiol. Stable expression of this construct in ER negative squamous cell carcinoma (SCC lines produced an estradiol dependent decrease in the number of cells that migrated through a reconstituted basement membrane. This decreased invasiveness was accompanied by estradiol dependent downregulation of MMP-9 activity as determined by gelatin zymography. Estradiol also produced transcriptional downregulation of an MMP-9 promoter construct in cells transiently transfected with the c-fosER expression vector. This downregulation was mediated by the AP-1 site at —79 by in the MMP-9 promoter. We concluded that the proximal AP-1 site mediated the transcriptional downregulation of the MMP-9 promoter by a conditionally activated c-fos fusion protein.

Canonical hedgehog signaling augments tumor angiogenesis by induction of VEGF-A in stromal perivascular cells

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Chen, Weiwei; Tang, Tracy; Eastham-Anderson, Jeff; Dunlap, Debra; Alicke, Bruno; Nannini, Michelle; Gould, Stephen; Yauch, Robert; Modrusan, Zora; DuPree, Kelly J.; Darbonne, Walter C.; Plowman, Greg; de Sauvage, Frederic J.; Callahan, Christopher A.

2011-01-01

Hedgehog (Hh) signaling is critical to the patterning and development of a variety of organ systems, and both ligand-dependent and ligand-independent Hh pathway activation are known to promote tumorigenesis. Recent studies have shown that in tumors promoted by Hh ligands, activation occurs within the stromal microenvironment. Testing whether ligand-driven Hh signaling promotes tumor angiogenesis, we found that Hh antagonism reduced the vascular density of Hh-producing LS180 and SW480 xenograf...

Investigating mechanisms of alkalinization for reducing primary breast tumor invasion.

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Robey, Ian F; Nesbit, Lance A

2013-01-01

The extracellular pH (pHe) of many solid tumors is acidic as a result of glycolytic metabolism and poor perfusion. Acidity promotes invasion and enhances metastatic potential. Tumor acidity can be buffered by systemic administration of an alkaline agent such as sodium bicarbonate. Tumor-bearing mice maintained on sodium bicarbonate drinking water exhibit fewer metastases and survive longer than untreated controls. We predict this effect is due to inhibition of tumor invasion. Reducing tumor invasion should result in fewer circulating tumor cells (CTCs). We report that bicarbonate-treated MDA-MB-231 tumor-bearing mice exhibited significantly lower numbers of CTCs than untreated mice (P cancer where systemic alkalinization slows the rate of invasion.

Contribution to Tumor Angiogenesis From Innate Immune Cells Within the Tumor Microenvironment: Implications for Immunotherapy

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Adriana Albini

2018-04-01

Full Text Available The critical role of angiogenesis in promoting tumor growth and metastasis is strongly established. However, tumors show considerable variation in angiogenic characteristics and in their sensitivity to antiangiogenic therapy. Tumor angiogenesis involves not only cancer cells but also various tumor-associated leukocytes (TALs and stromal cells. TALs produce chemokines, cytokines, proteases, structural proteins, and microvescicles. Vascular endothelial growth factor (VEGF and inflammatory chemokines are not only major proangiogenic factors but are also immune modulators, which increase angiogenesis and lead to immune suppression. In our review, we discuss the regulation of angiogenesis by innate immune cells in the tumor microenvironment, specific features, and roles of major players: macrophages, neutrophils, myeloid-derived suppressor and dendritic cells, mast cells, γδT cells, innate lymphoid cells, and natural killer cells. Anti-VEGF or anti-inflammatory drugs could balance an immunosuppressive microenvironment to an immune permissive one. Anti-VEGF as well as anti-inflammatory drugs could therefore represent partners for combinations with immune checkpoint inhibitors, enhancing the effects of immune therapy.

REGULATION OF TLR/RLR GENE ACTIVITY AND SYNTHESIS OF CYTOKINES DURING PHORBOL MYRISTATE ACETATE (PMA-INDUCED DIFFERENTIATION OF THP-1 MONOCYTES INTO MACROPHAGE-LIKE CELLS

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T. M. Sokolova

2017-01-01

Full Text Available The levels of TLR/RLR gene expression and production of some cytokines were studied in monocytic THP-1 cell line during its differentiation to mature macrophage-like forms induced by phorbol 12-myristate 13-acetate (PMA treatment for 1 and 5 days in vitro. For the first time, we have shown high induction levels for the genes that encode signaling immune receptors and transcription factors in response to PMA, as well as inhibitory effects of TLR3, TLR7/TLR8, TLR9-agonists in mature macrophages. The PMAactivated THP-1 macrophage-like cells secreted large quantitities of inflammatory IL-1β and TNFα cytokines into culture medium.

Tumor invasion of Salmonella enterica serovar Typhimurium is accompanied by strong hemorrhage promoted by TNF-alpha.

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Sara Leschner

Full Text Available BACKGROUND: Several facultative anaerobic bacteria with potential therapeutic abilities are known to preferentially colonize solid tumors after systemic administration. How they efficiently find and invade the tumors is still unclear. However, this is an important issue to be clarified when bacteria should be tailored for application in cancer therapy. METHODOLOGY/PRINCIPAL FINDINGS: We describe the initial events of colonization of an ectopic transplantable tumor by Salmonella enterica serovar Typhimurium. Initially, after intravenous administration, bacteria were found in blood, spleen, and liver. Low numbers were also detected in tumors associated with blood vessels as could be observed by immunohistochemistry. A rapid increase of TNF-alpha in blood was observed at that time, in addition to other pro-inflammatory cytokines. This induced a tremendous influx of blood into the tumors by vascular disruption that could be visualized in H&E stainings and quantified by hemoglobin measurements of tumor homogenate. Most likely, together with the blood, bacteria were flushed into the tumor. In addition, blood influx was followed by necrosis formation, bacterial growth, and infiltration of neutrophilic granulocytes. Depletion of TNF-alpha retarded blood influx and delayed bacterial tumor-colonization. CONCLUSION: Our findings emphasize similarities between Gram-negative tumor-colonizing bacteria and tumor vascular disrupting agents and show the involvement of TNF-alpha in the initial phase of tumor-colonization by bacteria.

VEGF promotes tumorigenesis and angiogenesis of human glioblastoma stem cells

International Nuclear Information System (INIS)

Oka, Naoki; Soeda, Akio; Inagaki, Akihito; Onodera, Masafumi; Maruyama, Hidekazu; Hara, Akira; Kunisada, Takahiro; Mori, Hideki; Iwama, Toru

2007-01-01

There is increasing evidence for the presence of cancer stem cells (CSCs) in malignant brain tumors, and these CSCs may play a pivotal role in tumor initiation, growth, and recurrence. Vascular endothelial growth factor (VEGF) promotes the proliferation of vascular endothelial cells (VECs) and the neurogenesis of neural stem cells. Using CSCs derived from human glioblastomas and a retrovirus expressing VEGF, we examined the effects of VEGF on the properties of CSCs in vitro and in vivo. Although VEGF did not affect the property of CSCs in vitro, the injection of mouse brains with VEGF-expressing CSCs led to the massive expansion of vascular-rich GBM, tumor-associated hemorrhage, and high morbidity, suggesting that VEGF promoted tumorigenesis via angiogenesis. These results revealed that VEGF induced the proliferation of VEC in the vascular-rich tumor environment, the so-called stem cell niche

Quantitative global and gene-specific promoter methylation in relation to biological properties of neuroblastomas

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Kiss Nimrod B

2012-09-01

Full Text Available Abstract Background In this study we aimed to quantify tumor suppressor gene (TSG promoter methylation densities levels in primary neuroblastoma tumors and cell lines. A subset of these TSGs is associated with a CpG island methylator phenotype (CIMP in other tumor types. Methods The study panel consisted of 38 primary tumors, 7 established cell lines and 4 healthy references. Promoter methylation was determined by bisulphate Pyrosequencing for 14 TSGs; and LINE-1 repeat element methylation was used as an indicator of global methylation levels. Results Overall mean TSG Z-scores were significantly increased in cases with adverse outcome, but were unrelated to global LINE-1 methylation. CIMP with hypermethylation of three or more gene promoters was observed in 6/38 tumors and 7/7 cell lines. Hypermethylation of one or more TSG (comprising TSGs BLU, CASP8, DCR2, CDH1, RASSF1A and RASSF2 was evident in 30/38 tumors. By contrast only very low levels of promoter methylation were recorded for APC, DAPK1, NORE1A, P14, P16, TP73, PTEN and RARB. Similar involvements of methylation instability were revealed between cell line models and neuroblastoma tumors. Separate analysis of two proposed CASP8 regulatory regions revealed frequent and significant involvement of CpG sites between exon 4 and 5, but modest involvement of the exon 1 region. Conclusions/significance The results highlight the involvement of TSG methylation instability in neuroblastoma tumors and cell lines using quantitative methods, support the use of DNA methylation analyses as a prognostic tool for this tumor type, and underscore the relevance of developing demethylating therapies for its treatment.

Galectin-1 as a potent target for cancer therapy: role in the tumor microenvironment.

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Ito, Koichi; Stannard, Kimberley; Gabutero, Elwyn; Clark, Amanda M; Neo, Shi-Yong; Onturk, Selda; Blanchard, Helen; Ralph, Stephen J

2012-12-01

The microenvironment of a tumor is a highly complex milieu, primarily characterized by immunosuppression, abnormal angiogenesis, and hypoxic regions. These features promote tumor progression and metastasis, resulting in poor prognosis and greater resistance to existing cancer therapies. Galectin-1 is a β-galactoside binding protein that is abundantly secreted by almost all types of malignant tumor cells. The expression of galectin-1 is regulated by hypoxia-inducible factor-1 (HIF-1) and it plays vital pro-tumorigenic roles within the tumor microenvironment. In particular, galectin-1 suppresses T cell-mediated cytotoxic immune responses and promotes tumor angiogenesis. However, since galectin-1 displays many different activities by binding to a number of diverse N- or O-glycan modified target proteins, it has been difficult to fully understand how galectin-1 supports tumor growth and metastasis. This review explores the importance of galectin-1 and glycan expression patterns in the tumor microenvironment and the potential effects of inhibiting galectin-1 as a therapeutic target for cancer treatment.

The epigenetic modifier PRDM5 functions as a tumor suppressor through modulating WNT/β-catenin signaling and is frequently silenced in multiple tumors.

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Xing-sheng Shu

Full Text Available BACKGROUND: PRDM (PRDI-BF1 and RIZ domain containing proteins are zinc finger proteins involved in multiple cellular regulations by acting as epigenetic modifiers. We studied a recently identified PRDM member PRDM5 for its epigenetic abnormality and tumor suppressive functions in multiple tumorigeneses. METHODOLOGY/PRINCIPAL FINDINGS: Semi-quantitative RT-PCR showed that PRDM5 was broadly expressed in human normal tissues, but frequently silenced or downregulated in multiple carcinoma cell lines due to promoter CpG methylation, including 80% (4/5 nasopharyngeal, 44% (8/18 esophageal, 76% (13/17 gastric, 50% (2/4 cervical, and 25% (3/12 hepatocellular carcinoma cell lines, but not in any immortalized normal epithelial cell lines. PRDM5 expression could be restored by 5-aza-2'-deoxycytidine demethylation treatment in silenced cell lines. PRDM5 methylation was frequently detected by methylation-specific PCR (MSP in multiple primary tumors, including 93% (43/46 nasopharyngeal, 58% (25/43 esophageal, 88% (37/42 gastric and 63% (29/46 hepatocellular tumors. PRDM5 was further found a stress-responsive gene, but its response was impaired when the promoter was methylated. Ectopic PRDM5 expression significantly inhibited tumor cell clonogenicity, accompanied by the inhibition of TCF/β-catenin-dependent transcription and downregulation of CDK4, TWIST1 and MDM2 oncogenes, while knocking down of PRDM5 expression lead to increased cell proliferation. ChIP assay showed that PRDM5 bound to its target gene promoters and suppressed their transcription. An inverse correlation between the expression of PRDM5 and activated β-catenin was also observed in cell lines. CONCLUSIONS/SIGNIFICANCE: PRDM5 functions as a tumor suppressor at least partially through antagonizing aberrant WNT/β-catenin signaling and oncogene expression. Frequent epigenetic silencing of PRDM5 is involved in multiple tumorigeneses, which could serve as a tumor biomarker.

Associations of RASSF1A, RARβ, and CDH1 promoter hypermethylation with oral cancer risk

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Wen, Guohong; Wang, Huadong; Zhong, Zhaohui

2018-01-01

Abstract Background: Oral tumor is a heterogeneous group of tumors, in which it has several different histopathological and molecular features. Recently, genetic and epigenetic alterations are often detected in the development of oral cancer. Gene promoter hypermethylation leads to the silencing of cancer related genes without changes of genes sequence. To clarify the effect of RAS association domain family protein 1a (RASSF1A), retinoic acid receptor beta (RARβ), and E-cadherin (CDH1) promoter hypermethylation on the risk of oral cancer, we performed this meta-analysis. Methods: PubMed, Web of Science, Embase, and Chinese National Knowledge Infrastructure (CNKI) databases were retrieved to identify eligible articles. Stata 12.0 software was used to analyze extracted data of the included articles. Odds ratios (ORs) with the corresponding 95% confidence interval (95% CI) were calculated to evaluate the associations of RASSF1A, RARβ, and CDH1 promoter hypermethylation with oral cancer risk. Results: Around 23 literatures with 29 studies were included in the final meta-analysis, in which 12 studies were about RASSF1A promoter methylation, 4 studies were about RARβ promoter methylation, and 13 studies were about CDH1 promoter methylation. Overall, the results of this meta-analysis showed that there were significant associations between RASSF1A, RARβ, and CDH1 promoter hypermethylation and oral cancer risk (RASSF1A, OR = 11.8, 95% CI = 6.14–22.66; RARβ, OR = 20.35, 95% CI = 5.64–73.39; CDH1, OR = 13.46, 95% CI = 5.31–34.17). In addition, we found that RASSF1A promoter hypermethylation exerted higher frequency in the tongue tumor than other site tumor in mouth (RASSF1A, tongue tumor vs other site tumor in mouth, unmethylation vs methylation, OR = 0.65, 95%CI = 0.44–0.98). Conclusion: RASSF1A, RARβ, and CDH1 promoter hypermethylation might significantly increase the risk of oral cancer. PMID:29538221

Promoter Hypermethylation of the EMP3 Gene in a Series of 229 Human Gliomas

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Marta Mellai

2013-01-01

Full Text Available The epithelial membrane protein 3 (EMP3 is a candidate tumor suppressor gene in the critical region 19q13.3 for several solid tumors, including tumors of the nervous systems. The aim of this study was to investigate the EMP3 promoter hypermethylation status in a series of 229 astrocytic and oligodendroglial tumors and in 16 GBM cell lines. The analysis was performed by methylation-specific PCR and capillary electrophoresis. Furthermore, the EMP3 expression at protein level was evaluated by immunohistochemistry and Western blotting analysis. Associations of EMP3 hypermethylation with total 1p/19q codeletion, MGMT promoter hypermethylation, IDH1/IDH2 and TP53 mutations, and EGFR amplification were studied, as well as its prognostic significance. The EMP3 promoter hypermethylation has been found in 39.5% of gliomas. It prevailed in low-grade tumors, especially in gliomas with an oligodendroglial component, and in sGBMs upon pGBMs. In oligodendroglial tumors, it was strongly associated with both IDH1/IDH2 mutations and total 1p/19q codeletion and inversely with EGFR gene amplification. No association was found with MGMT hypermethylation and TP53 mutations. In the whole series, the EMP3 hypermethylation status correlated with 19q13.3 loss and lack of EMP3 expression at protein level. A favorable prognostic significance on overall survival of the EMP3 promoter hypermethylation was found in patients with oligodendroglial tumors.

Pigment epithelial-derived factor gene loaded novel COOH-PEG-PLGA-COOH nanoparticles promoted tumor suppression by systemic administration

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Yu T

2016-02-01

proliferation of human umbilical vein endothelial cells in vitro and inhibited the tumor-induced angiogenesis in vivo by an alginate-encapsulated tumor cell assay. Further in vivo antitumor investigation, carried out in a C26 subcutaneous tumor model by intravenous injection, demonstrated that D-NPs could achieve a significant antitumor activity with sharply reduced microvessel density and significantly promoted tumor cell apoptosis. Additionally, the in vitro hemolysis analysis and in vivo serological and biochemical analysis revealed that D-NPs had no obvious toxicity. All the data indicated that the novel CPPC nanoparticles were ideal vectors for the systemic delivery of PEDF gene and might be widely used as systemic gene vectors. Keywords: pigment epithelium-derived factor gene, nanoparticles based on PLGA derivative, gene delivery, systemic delivery, tumor

Galangin and kaempferol suppress phorbol-12-myristate-13-acetate-induced matrix metalloproteinase-9 expression in human fibrosarcoma HT-1080 cells.

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Choi, Yu Jung; Lee, Young Hun; Lee, Seung-Taek

2015-01-01

Matrix metalloproteinase (MMP)-9 degrades type IV collagen in the basement membrane and plays crucial roles in several pathological implications, including tumorigenesis and inflammation. In this study, we analyzed the effect of flavonols on MMP-9 expression in phorbol-12-myristate-13-acetate (PMA)-induced human fibrosarcoma HT-1080 cells. Galangin and kaempferol efficiently decreased MMP-9 secretion, whereas fisetin only weakly decreased its secretion. Galangin and kaempferol did not affect cell viability at concentrations up to 30 μM. Luciferase reporter assays showed that galangin and kaempferol decrease transcription of MMP-9 mRNA. Moreover, galangin and kaempferol strongly reduce IκBα phosphorylation and significantly decrease JNK phosphorylation. These results indicate that galangin and kaempferol suppress PMA-induced MMP-9 expression by blocking activation of NF-κB and AP-1. Therefore, these flavonols could be used as chemopreventive agents to lower the risk of diseases involving MMP-9.

COX-2 gene expression in colon cancer tissue related to regulating factors and promoter methylation status

International Nuclear Information System (INIS)

Asting, Annika Gustafsson; Carén, Helena; Andersson, Marianne; Lönnroth, Christina; Lagerstedt, Kristina; Lundholm, Kent

2011-01-01

Increased cyclooxygenase activity promotes progression of colorectal cancer, but the mechanisms behind COX-2 induction remain elusive. This study was therefore aimed to define external cell signaling and transcription factors relating to high COX-2 expression in colon cancer tissue. Tumor and normal colon tissue were collected at primary curative operation in 48 unselected patients. COX-2 expression in tumor and normal colon tissue was quantified including microarray analyses on tumor mRNA accounting for high and low tumor COX-2 expression. Cross hybridization was performed between tumor and normal colon tissue. Methylation status of up-stream COX-2 promoter region was evaluated. Tumors with high COX-2 expression displayed large differences in gene expression compared to normal colon. Numerous genes with altered expression appeared in tumors of high COX-2 expression compared to tumors of low COX-2. COX-2 expression in normal colon was increased in patients with tumors of high COX-2 compared to normal colon from patients with tumors of low COX-2. IL1β, IL6 and iNOS transcripts were up-regulated among external cell signaling factors; nine transcription factors (ATF3, C/EBP, c-Fos, Fos-B, JDP2, JunB, c-Maf, NF-κB, TCF4) showed increased expression and 5 (AP-2, CBP, Elk-1, p53, PEA3) were decreased in tumors with high COX-2. The promoter region of COX-2 gene did not show consistent methylation in tumor or normal colon tissue. Transcription and external cell signaling factors are altered as covariates to COX-2 expression in colon cancer tissue, but DNA methylation of the COX-2 promoter region was not a significant factor behind COX-2 expression in tumor and normal colon tissue

COX-2 gene expression in colon cancer tissue related to regulating factors and promoter methylation status

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Lagerstedt Kristina

2011-06-01

Full Text Available Abstract Background Increased cyclooxygenase activity promotes progression of colorectal cancer, but the mechanisms behind COX-2 induction remain elusive. This study was therefore aimed to define external cell signaling and transcription factors relating to high COX-2 expression in colon cancer tissue. Method Tumor and normal colon tissue were collected at primary curative operation in 48 unselected patients. COX-2 expression in tumor and normal colon tissue was quantified including microarray analyses on tumor mRNA accounting for high and low tumor COX-2 expression. Cross hybridization was performed between tumor and normal colon tissue. Methylation status of up-stream COX-2 promoter region was evaluated. Results Tumors with high COX-2 expression displayed large differences in gene expression compared to normal colon. Numerous genes with altered expression appeared in tumors of high COX-2 expression compared to tumors of low COX-2. COX-2 expression in normal colon was increased in patients with tumors of high COX-2 compared to normal colon from patients with tumors of low COX-2. IL1β, IL6 and iNOS transcripts were up-regulated among external cell signaling factors; nine transcription factors (ATF3, C/EBP, c-Fos, Fos-B, JDP2, JunB, c-Maf, NF-κB, TCF4 showed increased expression and 5 (AP-2, CBP, Elk-1, p53, PEA3 were decreased in tumors with high COX-2. The promoter region of COX-2 gene did not show consistent methylation in tumor or normal colon tissue. Conclusions Transcription and external cell signaling factors are altered as covariates to COX-2 expression in colon cancer tissue, but DNA methylation of the COX-2 promoter region was not a significant factor behind COX-2 expression in tumor and normal colon tissue.

Oncomirs: from tumor biology to molecularly targeted anticancer strategies.

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Mocellin, Simone; Pasquali, Sandro; Pilati, Pierluigi

2009-01-01

Deregulation of microRNA (miRNA) promotes carcinogenesis, as these molecules can act as oncogenes or tumor suppressor genes. Here we provide an overview of miRNA biology, discuss the most recent findings on miRNA and cancer development/progression, and report on how tumor-related miRNAs (oncomirs) are being used to develop novel cancer specific therapeutic approaches.

Internalization, lysosomal degradation and new synthesis of surface membrane CD4 in phorbol ester-activated T-lymphocytes and U-937 cells

DEFF Research Database (Denmark)

Petersen, C M; Christensen, E I; Andresen, B S

1992-01-01

degradation was low in resting cells. Endocytosis and/or degradation of anti-CD4 mAb was suppressed by H7, and by inhibitors of membrane traffic (Monensin) and lysosome function (methylamine, chloroquine). Immunocytochemistry localized CD4 to the surface of unstimulated T-cells. Upon PMA stimulation...... occasional labeling was seen in endosomes but whole cell CD4 decreased dramatically. However, methylamine-treated PMA blasts showed accumulation of CD4 in lysosomes and accordingly, pulse-chase experiments in biolabeled cell cultures suggested a manifest reduction of CD4 half-life in response to PMA. Despite...... in activated cells was further evidenced by metabolic labeling and Northern blot analysis demonstrating unaltered or slightly increased CD4 protein and mRNA levels resulting from PMA. Our findings demonstrate that phorbol esters downregulate the cellular CD4 pool by endocytosis and subsequent lysosomal...

Migratory neighbors and distant invaders: tumor-associated niche cells

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Wels, Jared; Kaplan, Rosandra N.; Rafii, Shahin; Lyden, David

2008-01-01

The cancer environment is comprised of tumor cells as well as a wide network of stromal and vascular cells participating in the cellular and molecular events necessary for invasion and metastasis. Tumor secretory factors can activate the migration of host cells, both near to and far from the primary tumor site, as well as promote the exodus of cells to distant tissues. Thus, the migration of stromal cells and tumor cells among specialized microenvironments takes place throughout tumor and metastatic progression, providing evidence for the systemic nature of a malignancy. Investigations of the tumor–stromal and stromal–stromal cross-talk involved in cellular migration in cancer may lead to the design of novel therapeutic strategies. PMID:18316475

Heparin-binding epidermal growth factor-like growth factor promotes neuroblastoma differentiation.

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Gaviglio, Angela L; Knelson, Erik H; Blobe, Gerard C

2017-05-01

High-risk neuroblastoma is characterized by undifferentiated neuroblasts and low schwannian stroma content. The tumor stroma contributes to the suppression of tumor growth by releasing soluble factors that promote neuroblast differentiation. Here we identify heparin-binding epidermal growth factor-like growth factor (HBEGF) as a potent prodifferentiating factor in neuroblastoma. HBEGF mRNA expression is decreased in human neuroblastoma tumors compared with benign tumors, with loss correlating with decreased survival. HBEGF protein is expressed only in stromal compartments of human neuroblastoma specimens, with tissue from high-stage disease containing very little stroma or HBEGF expression. In 3 human neuroblastoma cell lines (SK-N-AS, SK-N-BE2, and SH-SY5Y), soluble HBEGF is sufficient to promote neuroblast differentiation and decrease proliferation. Heparan sulfate proteoglycans and heparin derivatives further enhance HBEGF-induced differentiation by forming a complex with the epidermal growth factor receptor, leading to activation of the ERK1/2 and STAT3 pathways and up-regulation of the inhibitor of DNA binding transcription factor. These data support a role for loss of HBEGF in the neuroblastoma tumor microenvironment in neuroblastoma pathogenesis.-Gaviglio, A. L., Knelson, E. H., Blobe, G. C. Heparin-binding epidermal growth factor-like growth factor promotes neuroblastoma differentiation. © FASEB.

Effect of hGC-MSCs from human gastric cancer tissue on cell proliferation, invasion and epithelial-mesenchymal transition in tumor tissue of gastric cancer tumor-bearing mice.