Oroxin B selectively induces tumor-suppressive ER stress and concurrently inhibits tumor-adaptive ER stress in B-lymphoma cells for effective anti-lymphoma therapy

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Yang, Ping; Fu, Shilong; Cao, Zhifei; Liao, Huaidong; Huo, Zihe; Pan, Yanyan; Zhang, Gaochuan; Gao, Aidi; Zhou, Quansheng, E-mail: zhouqs@suda.edu.cn

2015-10-15

Cancer cells have both tumor-adaptive and -suppressive endoplasmic reticulum (ER) stress machineries that determine cell fate. In malignant tumors including lymphoma, constant activation of tumor-adaptive ER stress and concurrent reduction of tumor-suppressive ER stress favors cancer cell proliferation and tumor growth. Current ER stress-based anti-tumor drugs typically activate both tumor-adaptive and -suppressive ER stresses, resulting in low anti-cancer efficacy; hence, selective induction of tumor-suppressive ER stress and inhibition of tumor-adaptive ER stress are new strategies for novel anti-cancer drug discovery. Thus far, specific tumor-suppressive ER stress therapeutics have remained absent in clinical settings. In this study, we explored unique tumor-suppressive ER stress agents from the traditional Chinese medicinal herb Oroxylum indicum, and found that a small molecule oroxin B selectively induced tumor-suppressive ER stress in malignant lymphoma cells, but not in normal cells, effectively inhibited lymphoma growth in vivo, and significantly prolonged overall survival of lymphoma-xenografted mice without obvious toxicity. Mechanistic studies have revealed that the expression of key tumor-adaptive ER-stress gene GRP78 was notably suppressed by oroxin B via down-regulation of up-stream key signaling protein ATF6, while tumor-suppressive ER stress master gene DDIT3 was strikingly activated through activating the MKK3-p38 signaling pathway, correcting the imbalance between tumor-suppressive DDIT3 and tumor-adaptive GRP78 in lymphoma. Together, selective induction of unique tumor-suppressive ER stress and concurrent inhibition of tumor-adaptive ER stress in malignant lymphoma are new and feasible approaches for novel anti-lymphoma drug discovery and anti-lymphoma therapy. - Highlights: • Oroxin B selectively induces tumor-suppressive ER stress in B-lymphoma cells. • Oroxin B significantly prolonged overall survival of lymphoma-xenografted mice. �

Berberine suppresses tumorigenicity and growth of nasopharyngeal carcinoma cells by inhibiting STAT3 activation induced by tumor associated fibroblasts

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Tsang, Chi Man; Cheung, Yuk Chun; Lui, Vivian Wai-Yan; Yip, Yim Ling; Zhang, Guitao; Lin, Victor Weitao; Cheung, Kenneth Chat-Pan; Feng, Yibin; Tsao, Sai Wah

2013-01-01

Cortidis rhizoma (Huanglian) and its major therapeutic component, berberine, have drawn extensive attention in recent years for their anti-cancer properties. Growth inhibitory effects of berberine on multiple types of human cancer cells have been reported. Berberine inhibits invasion, induces cell cycle arrest and apoptosis in human cancer cells. The anti-inflammatory property of berberine, involving inhibition of Signal Transducer and Activator of Transcription 3 (STAT3) activation, has also been documented. In this study, we have examined the effects of berberine on tumorigenicity and growth of nasopharyngeal carcinoma (NPC) cells and their relationship to STAT3 signaling using both in vivo and in vitro models. Berberine effectively inhibited the tumorigenicity and growth of an EBV-positive NPC cell line (C666-1) in athymic nude mice. Inhibition of tumorigenic growth of NPC cells in vivo was correlated with effective inhibition of STAT3 activation in NPC cells inside the tumor xenografts grown in nude mice. In vitro, berberine inhibited both constitutive and IL-6-induced STAT3 activation in NPC cells. Inhibition of STAT3 activation by berberine induced growth inhibition and apoptotic response in NPC cells. Tumor-associated fibroblasts were found to secret IL-6 and the conditioned medium harvested from the fibroblasts also induced STAT3 activation in NPC cells. Furthermore, STAT3 activation by conditioned medium of tumor-associated fibroblasts could be blocked by berberine or antibodies against IL-6 and IL-6R. Our observation that berberine effectively inhibited activation of STAT3 induced by tumor-associated fibroblasts suggests a role of berberine in modulating the effects of tumor stroma on the growth of NPC cells. The effective inhibition of STAT3 activation in NPC cells by berberine supports its potential use in the treatment of NPC

Tumor-associated mesenchymal stem cells inhibit naïve T cell expansion by blocking cysteine export from dendritic cells.

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Ghosh, Tithi; Barik, Subhasis; Bhuniya, Avishek; Dhar, Jesmita; Dasgupta, Shayani; Ghosh, Sarbari; Sarkar, Madhurima; Guha, Ipsita; Sarkar, Koustav; Chakrabarti, Pinak; Saha, Bhaskar; Storkus, Walter J; Baral, Rathindranath; Bose, Anamika

2016-11-01

Mesenchymal stem cells (MSCs) represent an important cellular constituent of the tumor microenvironment, which along with tumor cells themselves, serve to regulate protective immune responses in support of progressive disease. We report that tumor MSCs prevent the ability of dendritic cells (DC) to promote naïve CD4(+) and CD8(+) T cell expansion, interferon gamma secretion and cytotoxicity against tumor cells, which are critical to immune-mediated tumor eradication. Notably, tumor MSCs fail to prevent DC-mediated early T cell activation events or the ability of responder T cells to produce IL-2. The immunoregulatory activity of tumor MSCs is IL-10- and STAT3-dependent, with STAT3 repressing DC expression of cystathionase, a critical enzyme that converts methionine-to-cysteine. Under cysteine-deficient priming conditions, naïve T cells exhibit defective cellular metabolism and proliferation. Bioinformatics analyses as well as in vitro observations suggest that STAT3 may directly bind to a GAS-like motif within the cystathionase promoter (-269 to -261) leading to IL-10-STAT3 mediated repression of cystathionase gene transcription. Our collective results provide evidence for a novel mechanism of tumor MSC-mediated T cell inhibition within tumor microenvironment. © 2016 UICC.

Arctigenin inhibits prostate tumor cell growth in vitro and in vivo

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Piwen Wang

2017-06-01

Full Text Available The low bioavailability of most phytochemicals limits their translation to humans. We investigated whether arctigenin, a novel anti-inflammatory lignan from the seeds of Arctium lappa, has favorable bioavailability/potency against prostate cancer. The anticarcinogenic activity of arctigenin was investigated both in vitro using the androgen-sensitive LNCaP and LAPC-4 human prostate cancer cells and pre-malignant WPE1-NA22 cells, and in vivo using xenograft mouse models. Arctigenin at lower doses (<2 μM significantly inhibited the proliferation of LNCaP and LAPC-4 cells by 30–50% at 48 h compared to control, and inhibited WPE1-NA22 cells by 75%, while did not affect normal prostate epithelial cells. Male severe combined immunodeficiency (SCID mice were implanted subcutaneously with LAPC-4 cells for in vivo studies. In one experiment, the intervention started one week after tumor implantation. Mice received arctigenin at 50 mg/kg (LD or 100 mg/kg (HD b.w. daily or vehicle control by oral gavage. After 6 weeks, tumor growth was inhibited by 50% (LD and 70% (HD compared to control. A stronger tumor inhibitory effect was observed in a second experiment where arctigenin intervention started two weeks prior to tumor implantation. Arc was detectable in blood and tumors in Arc groups, with a mean value up to 2.0 μM in blood, and 8.3 nmol/g tissue in tumors. Tumor levels of proliferation marker Ki67, total and nuclear androgen receptor, and growth factors including VEGF, EGF, and FGF-β were significantly decreased by Arc, along with an increase in apoptosis marker of Bax/Bcl-2 ratio. Genes responsive to arctigenin were identified including TIMP3 and ZNF185, and microRNAs including miR-126-5p, and miR-21-5p. This study provides the first in vivo evidence of the strong anticancer activity of arctigenin in prostate cancer. The effective dose of arctigenin in vitro is physiologically achievable in vivo, which provides a high promise in its

Inhibition of NF-κB in Tumor Cells Exacerbates Immune Cell Activation Following Photodynamic Therapy

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Broekgaarden, Mans; Kos, Milan; Jurg, Freek A.; van Beek, Adriaan A.; van Gulik, Thomas M.; Heger, Michal

2015-01-01

Although photodynamic therapy (PDT) yields very good outcomes in numerous types of superficial solid cancers, some tumors respond suboptimally to PDT. Novel treatment strategies are therefore needed to enhance the efficacy in these therapy-resistant tumors. One of these strategies is to combine PDT with inhibitors of PDT-induced survival pathways. In this respect, the transcription factor nuclear factor κB (NF-κB) has been identified as a potential pharmacological target, albeit inhibition of NF-κB may concurrently dampen the subsequent anti-tumor immune response required for complete tumor eradication and abscopal effects. In contrast to these postulations, this study demonstrated that siRNA knockdown of NF-κB in murine breast carcinoma (EMT-6) cells increased survival signaling in these cells and exacerbated the inflammatory response in murine RAW 264.7 macrophages. These results suggest a pro-death and immunosuppressive role of NF-κB in PDT-treated cells that concurs with a hyperstimulated immune response in innate immune cells. PMID:26307977

Molecular mechanisms involved in the inhibition of tumor cells proliferation exposed to elevated concentrations of the epidermal growth factor

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Guillen, Isabel A; Berlanga, Jorge; Camacho, Hanlet

2013-01-01

The EGF promotes inhibition of cell proliferation in vitro and in vivo models depending on its concentration, application schema and the type of tumor cells on which it acts. Our research hypothesis was based on the fact that the EGF varies the expression of genes involved in a negative regulation of tumor cell lines proliferation carrying high levels of its receptor (EGFR). Our objectives were, to obtain information about the effect of EGF on tumor cell proliferation in vitro and in vivo models and, know the gene expression patterns of a group of genes involved in cancer signaling pathways and EGFR. The results showed that EGF at nanomolar concentrations inhibits the tumor cells proliferation bearing high levels of EGFR and, promotes the survival of treated animals, establishing a direct relationship between the inhibition of cell proliferation, high concentrations of EGF and, high amount of EGFR in the cells. The differential gene expression profile showed a variation in a group of genes which exert a powerful control over the cell cycle progression, gene transcription and apoptosis. It was concluded that the inhibition of tumor cell proliferation by the action of EGF is due to activation of molecular mechanisms controlling cell cycle progression. This work won the Annual Award of the Cuban Academy of Sciences in 2012

SAMHD1 is down regulated in lung cancer by methylation and inhibits tumor cell proliferation

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Wang, Jia-lei; Lu, Fan-zhen; Shen, Xiao-Yong; Wu, Yun; Zhao, Li-ting

2014-01-01

Highlights: • SAMHD1 expression level is down regulated in lung adenocarcinoma. • The promoter of SAMHD1 is methylated in lung adenocarcinoma. • Over expression of SAMHD1 inhibits the proliferation of lung cancer cells. - Abstract: The function of dNTP hydrolase SAMHD1 as a viral restriction factor to inhibit the replication of several viruses in human immune cells was well established. However, its regulation and function in lung cancer have been elusive. Here, we report that SAMHD1 is down regulated both on protein and mRNA levels in lung adenocarcinoma compared to adjacent normal tissue. We also found that SAMHD1 promoter is highly methylated in lung adenocarcinoma, which may inhibit its gene expression. Furthermore, over expression of the SAMHD1 reduces dNTP level and inhibits the proliferation of lung tumor cells. These results reveal the regulation and function of SAMHD1 in lung cancer, which is important for the proliferation of lung tumor cells

Shikonin Inhibits the Proliferation of Human Breast Cancer Cells by Reducing Tumor-Derived Exosomes

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Yao Wei

2016-06-01

Full Text Available Shikonin is a naphthoquinone isolated from the traditional Chinese medicine Lithospermum. It has been used in the treatment of various tumors. However, the effects of shikonin on such diseases have not been fully elucidated. In the present study, we detected the exosome release of a breast cancer cell line (MCF-7 with shikonin treatment and found a positive relationship between the level of secreted exosomes and cell proliferation. We next analyzed miRNA profiles in MCF-7 cells and exosomes and found that some miRNAs are specifically sorted and abundant in exosomes. Knockdown of the most abundant miRNAs in exosomes and the MCF-7 proliferation assay showed that miR-128 in exosomes negatively regulates the level of Bax in MCF-7 recipient cells and inhibits cell proliferation. These results show that shikonin inhibits the proliferation of MCF-7 cells through reducing tumor-derived exosomal miR-128. The current study suggests that shikonin suppresses MCF-7 growth by the inhibition of exosome release.

Pharmacological inhibition of radiation induced in vitro tumor cell/endothelium cell interactions and in vivo metastasis processes

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Herzog, Melanie

2013-01-01

Exposure of endothelial cells with ionizing radiation (IR) or treatment with inflammatory cytokines (e. g. TNFα) induces a Rho-GTPase and NF-κB dependent activation of the expression of various cell adhesion molecules, including E-selectin. E-selectin mediates the adhesion of tumor cells (TC) to endothelial cells and is probably involved in the extravasation step of circulating tumor cells. HMG-CoA reductase inhibitors (e. g. lovastatin) inhibit the function of Rho-GTPases and thus are anticipated to attenuate Rho-regulated cell-cell-adhesion as well. This study focuses on the influence of IR and TNFα on the expression of endothelial- and/or tumor cell-specific pro-adhesive factors and whether these effects are influenced by lovastatin. To this end, the effect of IR and TNFα on cell-cell-interactions between human colon carcinoma cells (HT29) and human umbilical vein endothelial cells (HUVEC) was investigated using an ELISA-based cell adhesion-assay. Moreover, the influence of pre-treatment with lovastatin and other types of inhibitors on HUVEC-HT29 adhesion was monitored. Additionally, we investigated the effect of lovastatin on mRNA expression level of different cell adhesion molecules, metastatic factors and DNA-repair genes upon radiation exposure by qRT-PCR. To scrutinize the in vivo relevance of the data obtained, we investigated the effect of total body irradiation (TBI) on the mRNA expression of pro-adhesive factors in BALB/c mice. To analyze tumor cell extravasation, tumor cells were injected into the lateral tail vein of immundeficient mice, followed by total body irradiation (TBI, 4 Gy). After four weeks a large increase of lung metastases was monitored, which could be blocked by preatreatment of the mice with lovastatin, the Rac1-specific small-molecule inhibitor NSC23766 as well as the sLe x -mimetic glycyrrhizin. Summarizing, we provide evidence, that irradiation promotes upregulation of different cell adhesion molecules in vitro and stimulates

Characterization of Compounds with Tumor-Cell Proliferation Inhibition Activity from Mushroom (Phellinus baumii) Mycelia Produced by Solid-State Fermentation.

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Zhang, Henan; Shao, Qian; Wang, Wenhan; Zhang, Jingsong; Zhang, Zhong; Liu, Yanfang; Yang, Yan

2017-04-27

The inhibition of tumor-cell proliferationbyan organicsolvent extract from the solid-state fermentation of Phellinus baumii mycelia inoculated in rice medium was investigated in vitro. The active compounds inhibiting tumor-cell proliferation were characterized. Results revealed that all (petroleum ether, chloroform, ethyl acetate, and butanol) fractions inhibited tumor-cell proliferation in a dose-dependent fashion. The ethyl acetate extract had the highest inhibitory effecton tumor-cell proliferation, and the butanol fraction had the lowest. Six compounds were isolated and purified from the ethyl acetate extract of P. baumii mycelia by the tandem application of silica-gel column chromatography (SGCC), high-speed countercurrent chromatography (HSCCC), and preparative HPLC. These compounds were identified by NMR and electrospray ionization-mass spectrometry (ESI-MS) spectroscopic methods as ergosterol (RF1), ergosta-7,22-dien-3β-yl pentadecanoate (RF3), 3,4-dihydroxy benzaldehyde(RF6), inoscavinA (RF7), baicalein(RF10), and 24-ethylcholesta-5,22-dien-3β-ol (RF13). To further clarify the activity of these compounds, the cell-proliferation-inhibition tests of these compounds on various tumor cells were carried out and evaluatedin vitro. Results suggested that compounds RF6, RF7, and RF10 had potent inhibition effects on the proliferation of a series of tumor cell lines, including K562, L1210, SW620, HepG2, LNCaP, and MCF-7cells. These findings indicated that P. baumii mycelia produced by solid-state fermentation in rice canbe used to obtain active compounds with the ability to inhibittumor-cell proliferation.

DSGOST inhibits tumor growth by blocking VEGF/VEGFR2-activated angiogenesis.

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Choi, Hyeong Sim; Lee, Kangwook; Kim, Min Kyoung; Lee, Kang Min; Shin, Yong Cheol; Cho, Sung-Gook; Ko, Seong-Gyu

2016-04-19

Tumor growth requires a process called angiogenesis, a new blood vessel formation from pre-existing vessels, as newly formed vessels provide tumor cells with oxygen and nutrition. Danggui-Sayuk-Ga-Osuyu-Saenggang-Tang (DSGOST), one of traditional Chinese medicines, has been widely used in treatment of vessel diseases including Raynaud's syndrome in Northeast Asian countries including China, Japan and Korea. Therefore, we hypothesized that DSGOST might inhibit tumor growth by targeting newly formed vessels on the basis of its historical prescription. Here, we demonstrate that DSGOST inhibits tumor growth by inhibiting VEGF-induced angiogenesis. DSGOST inhibited VEGF-induced angiogenic abilities of endothelial cells in vitro and in vivo, which resulted from its inhibition of VEGF/VEGFR2 interaction. Furthermore, DSGOST attenuated pancreatic tumor growth in vivo by reducing angiogenic vessel numbers, while not affecting pancreatic tumor cell viability. Thus, our data conclude that DSGOST inhibits VEGF-induced tumor angiogenesis, suggesting a new indication for DSGOST in treatment of cancer.

Arctigenin preferentially induces tumor cell death under glucose deprivation by inhibiting cellular energy metabolism.

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Gu, Yuan; Qi, Chunting; Sun, Xiaoxiao; Ma, Xiuquan; Zhang, Haohao; Hu, Lihong; Yuan, Junying; Yu, Qiang

2012-08-15

Selectively eradicating cancer cells with minimum adverse effects on normal cells is a major challenge in the development of anticancer therapy. We hypothesize that nutrient-limiting conditions frequently encountered by cancer cells in poorly vascularized solid tumors might provide an opportunity for developing selective therapy. In this study, we investigated the function and molecular mechanisms of a natural compound, arctigenin, in regulating tumor cell growth. We demonstrated that arctigenin selectively promoted glucose-starved A549 tumor cells to undergo necrosis by inhibiting mitochondrial respiration. In doing so, arctigenin elevated cellular level of reactive oxygen species (ROS) and blocked cellular energy metabolism in the glucose-starved tumor cells. We also demonstrated that cellular ROS generation was caused by intracellular ATP depletion and played an essential role in the arctigenin-induced tumor cell death under the glucose-limiting condition. Furthermore, we combined arctigenin with the glucose analogue 2-deoxyglucose (2DG) and examined their effects on tumor cell growth. Interestingly, this combination displayed preferential cell-death inducing activity against tumor cells compared to normal cells. Hence, we propose that the combination of arctigenin and 2DG may represent a promising new cancer therapy with minimal normal tissue toxicity. Crown Copyright © 2012. Published by Elsevier Inc. All rights reserved.

Retinoid inhibition of in vitro invasion of human amnion basement membrane by human tumor cells

International Nuclear Information System (INIS)

Fazely, F.

1988-01-01

The effects measured were the inhibition of tumor cell migration through the basement membrane (BM) and tumor cell degradative enzyme activity on 3 H-proline labeled collagenous and non collagenous components of the BM. The human lung carcinoma A549 or the human Ewing's sarcoma TC-106 cell lines treated with retinoids for two days were incubated on the BM in the absence of retinoids. A dose-dependent inhibition of cell invasion was produced by retinoids. Among the retinoids tested the most powerful was retinol acetate which inhibited invasion by 50% of A549 cells at a concentration of 0.09 μg/ml, and TC-106 cells at 0.08 μg/ml. Retinol acetate inhibited A549 and TC-106 cell growth by approximately 50% at levels almost 100-fold higher than those needed for antiinvasive activity. Retinol acetate was about 20 times more potent than retinoic acid and 30 times more than retinol palmitate. Furthermore, A549 cells treated with retinol acetate, under conditions whereby an anti-invasive state was induced,showed an increase in the number of cellular retinoic acid binding proteins (CRABP), a decrease in the activity of type IV collagenase and ectosialyltransferase, and no change in the activity of transglutaminase

Rosiglitazone inhibits metastasis development of a murine mammary tumor cell line LMM3

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Magenta, Gabriela; Borenstein, Ximena; Rolando, Romina; Jasnis, María Adela

2008-01-01

Activation of peroxisome proliferator-activated receptors γ (PPARγ) induces diverse effects on cancer cells. The thiazolidinediones (TZDs), such as troglitazone and ciglitazone, are PPARγ agonists exhibiting antitumor activities; however, the underlying mechanism remains inconclusive. Rosiglitazone (RGZ), a synthetic ligand of PPARγ used in the treatment of Type 2 diabetes, inhibits growth of some tumor cells and is involved in other processes related to cancer progression. Opposing results have also been reported with different ligands on tumor cells. The purpose of this study was to determine if RGZ and 15d-PGJ 2 induce antitumor effects in vivo and in vitro on the murine mammary tumor cell line LMM3. The effect on LMM3 cell viability and nitric oxide (NO) production of different doses of RGZ, 15-dPGJ 2 , BADGE and GW9662 were determined using the MTS colorimetric assay and the Griess reaction respectively. In vivo effect of orally administration of RGZ on tumor progression was evaluated either on s.c. primary tumors as well as on experimental metastasis. Cell adhesion, migration (wound assay) and invasion in Transwells were performed. Metalloproteinase activity (MMP) was determined by zymography in conditioned media from RGZ treated tumor cells. PPARγ expression was detected by inmunohistochemistry in formalin fixed tumors and by western blot in tumor cell lysates. RGZ orally administered to tumor-bearing mice decreased the number of experimental lung metastases without affecting primary s.c. tumor growth. Tumor cell adhesion and migration, as well as metalloproteinase MMP-9 activity, decreased in the presence of 1 μM RGZ (non-cytotoxic dose). RGZ induced PPARγ protein expression in LMM3 tumors. Although metabolic activity -measured by MTS assay- diminished with 1–100 μM RGZ, 1 μM-treated cells recovered their proliferating capacity while 100 μM treated cells died. The PPARγ antagonist Biphenol A diglicydyl ether (BADGE) did not affect RGZ activity

Binimetinib inhibits MEK and is effective against neuroblastoma tumor cells with low NF1 expression

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Woodfield, Sarah E.; Zhang, Linna; Scorsone, Kathleen A.; Liu, Yin; Zage, Peter E.

2016-01-01

Novel therapies are needed for children with high-risk and relapsed neuroblastoma. We hypothesized that MAPK/ERK kinase (MEK) inhibition with the novel MEK1/2 inhibitor binimetinib would be effective in neuroblastoma preclinical models. Levels of total and phosphorylated MEK and extracellular signal-regulated kinase (ERK) were examined in primary neuroblastoma tumor samples and in neuroblastoma cell lines by Western blot. A panel of established neuroblastoma tumor cell lines was treated with increasing concentrations of binimetinib, and their viability was determined using MTT assays. Western blot analyses were performed to examine changes in total and phosphorylated MEK and ERK and to measure apoptosis in neuroblastoma tumor cells after binimetinib treatment. NF1 protein levels in neuroblastoma cell lines were determined using Western blot assays. Gene expression of NF1 and MEK1 was examined in relationship to neuroblastoma patient outcomes. Both primary neuroblastoma tumor samples and cell lines showed detectable levels of total and phosphorylated MEK and ERK. IC 50 values for cells sensitive to binimetinib ranged from 8 nM to 1.16 μM, while resistant cells did not demonstrate any significant reduction in cell viability with doses exceeding 15 μM. Sensitive cells showed higher endogenous expression of phosphorylated MEK and ERK. Gene expression of NF1, but not MEK1, correlated with patient outcomes in neuroblastoma, and NF1 protein expression also correlated with responses to binimetinib. Neuroblastoma tumor cells show a range of sensitivities to the novel MEK inhibitor binimetinib. In response to binimetinib, sensitive cells demonstrated complete loss of phosphorylated ERK, while resistant cells demonstrated either incomplete loss of ERK phosphorylation or minimal effects on MEK phosphorylation, suggesting alternative mechanisms of resistance. NF1 protein expression correlated with responses to binimetinib, supporting the use of NF1 as a biomarker to identify

Transient mTOR inhibition facilitates continuous growth of liver tumors by modulating the maintenance of CD133+ cell populations.

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Zhaojuan Yang

Full Text Available The mammalian target of the rapamycin (mTOR pathway, which drives cell proliferation, is frequently hyperactivated in a variety of malignancies. Therefore, the inhibition of the mTOR pathway has been considered as an appropriate approach for cancer therapy. In this study, we examined the roles of mTOR in the maintenance and differentiation of cancer stem-like cells (CSCs, the conversion of conventional cancer cells to CSCs and continuous tumor growth in vivo. In H-Ras-transformed mouse liver tumor cells, we found that pharmacological inhibition of mTOR with rapamycin greatly increased not only the CD133+ populations both in vitro and in vivo but also the expression of stem cell-like genes. Enhancing mTOR activity by over-expressing Rheb significantly decreased CD133 expression, whereas knockdown of the mTOR yielded an opposite effect. In addition, mTOR inhibition severely blocked the differentiation of CD133+ to CD133- liver tumor cells. Strikingly, single-cell culture experiments revealed that CD133- liver tumor cells were capable of converting to CD133+ cells and the inhibition of mTOR signaling substantially promoted this conversion. In serial implantation of tumor xenografts in nude BALB/c mice, the residual tumor cells that were exposed to rapamycin in vivo displayed higher CD133 expression and had increased secondary tumorigenicity compared with the control group. Moreover, rapamycin treatment also enhanced the level of stem cell-associated genes and CD133 expression in certain human liver tumor cell lines, such as Huh7, PLC/PRC/7 and Hep3B. The mTOR pathway is significantly involved in the generation and the differentiation of tumorigenic liver CSCs. These results may be valuable for the design of more rational strategies to control clinical malignant HCC using mTOR inhibitors.

Combination of Vorinostat and caspase-8 inhibition exhibits high anti-tumoral activity on endometrial cancer cells.

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Bergadà, Laura; Sorolla, Annabel; Yeramian, Andree; Eritja, Nuria; Mirantes, Cristina; Matias-Guiu, Xavier; Dolcet, Xavier

2013-08-01

Histone deacetylase inhibitors such as Vorinostat display anti-neoplastic activity against a variety of solid tumors. Here, we have investigated the anti-tumoral activity of Vorinostat on endometrial cancer cells. We have found that Vorinostat caused cell growth arrest, loss of clonogenic growth and apoptosis of endometrial cancer cells. Vorinostat-induced the activation of caspase-8 and -9, the initiators caspases of the extrinsic and the intrinsic apoptotic pathways, respectively. Next, we investigated the role of the extrinsic pathway in apoptosis triggered by Vorinostat. We found that Vorinostat caused a dramatic decrease of FLIP mRNA and protein levels. However, overexpression of the long from of FLIP did not block Vorinostat-induced apoptosis. To further investigate the role of extrinsic apoptotic pathway in Vorinostat-induced apoptosis, we performed an shRNA-mediated knock-down of caspase-8. Surprisingly, downregulation of caspase-8 alone caused a marked decrease in clonogenic ability and reduced the growth of endometrial cancer xenografts in vivo, revealing that targeting caspase-8 may be an attractive target for anticancer therapy on endometrial tumors. Furthermore, combination of caspase-8 inhibition and Vorinostat treatment caused an enhancement of apoptotic cell death and a further decrease of clonogenic growth of endometrial cancer cells. More importantly, combination of Vorinostat and caspase-8 inhibition caused a nearly complete inhibition of tumor xenograft growth. Finally, we demonstrate that cell death triggered by Vorinostat alone or in combination with caspase-8 shRNAs was inhibited by the anti-apoptotic protein Bcl-XL. Our results suggest that combinatory therapies using Vorinostat treatment and caspase-8 inhibition can be an effective treatment for endometrial carcinomas. Copyright © 2013 Federation of European Biochemical Societies. Published by Elsevier B.V. All rights reserved.

Inhibition of c-Jun N-terminal kinase sensitizes tumor cells to flavonoid-induced apoptosis through down-regulation of JunD

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Kook, Sung-Ho; Son, Young-Ok; Jang, Yong-Suk; Lee, Kyung-Yeol; Lee, Seung-Ah; Kim, Beom-Soo; Lee, Hyun-Jeong; Lee, Jeong-Chae

2008-01-01

Reduction of susceptibility to apoptosis signals is a crucial step in carcinogenesis. Therefore, sensitization of tumor cells to apoptosis is a promising therapeutic strategy. c-Jun NH 2 -terminal kinase (JNK) has been implicated in stress-induced apoptosis. However, many studies also emphasize the role of JNK on cell survival, although its mechanisms are not completely understood. Previously, we found that inhibition of JNK activity promotes flavonoid-mediated apoptosis of human osteosarcoma cells. We thus determined whether inhibition of JNK sensitizes tumor cells to a bioflavonoid-induced apoptosis, and whether this effect of JNK is a general effect. As the results, quercetin and genistein as well as a flavonoid fraction induced apoptosis of tumor cells, which was further accelerated by specific JNK inhibitor, SP600125 or by small interfering RNA specific to JNK1/2. This effect was specific to types of cells because it was further apparent in tumorigenic cell lines. Inhibition of JNK by SP600125 also reduced flavonoid-stimulated nuclear induction of JunD which was known to have protective role in apoptosis, whereas JNK inhibition alone had little effect on apoptosis. The flavonoid-induced apoptosis of tumor cells was significantly enhanced by transfecting them with antisense JunD oligonucleotides. These results suggest that inhibition of JNK facilitates flavonoid-induced apoptosis through down-regulation of JunD, which is further sensitive to tumor cells. Therefore, combination with a specific JNK inhibitor further enhances the anti-cancer and chemopreventive potential of bio-flavonoids

Dietary rice bran component γ-oryzanol inhibits tumor growth in tumor-bearing mice.

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Kim, Sung Phil; Kang, Mi Young; Nam, Seok Hyun; Friedman, Mendel

2012-06-01

We investigated the effects of rice bran and components on tumor growth in mice. Mice fed standard diets supplemented with rice bran, γ-oryzanol, Ricetrienol®, ferulic acid, or phytic acid for 2 weeks were inoculated with CT-26 colon cancer cells and fed the same diet for two additional weeks. Tumor mass was significantly lower in the γ-oryzanol and less so in the phytic acid group. Tumor inhibition was associated with the following biomarkers: increases in cytolytic activity of splenic natural killer (NK) cells; partial restoration of nitric oxide production and phagocytosis in peritoneal macrophages increases in released the pro-inflammatory cytokines tumor necrosis factor-α, IL-1β, and IL-6 from macrophages; and reductions in the number of blood vessels inside the tumor. Pro-angiogenic biomarkers vascular endothelial growth factor (VEGF), cyclooxygenase-2 (COX-2), and 5-lipoxygenase-5 (5-LOX) were also significantly reduced in mRNA and protein expression by tumor genes. ELISA of tumor cells confirmed reduced expression of COX-2 and 5-LOX up to 30%. Reduced COX-2 and 5-LOX expression downregulated VEGF and inhibited neoangiogenesis inside the tumors. Induction of NK activity, activation of macrophages, and inhibition of angiogenesis seem to contribute to the inhibitory mechanism of tumor regression by γ-oryzanol. © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Platelet-camouflaged nanococktail: Simultaneous inhibition of drug-resistant tumor growth and metastasis via a cancer cells and tumor vasculature dual-targeting strategy.

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Jing, Lijia; Qu, Haijing; Wu, Dongqi; Zhu, Chaojian; Yang, Yongbo; Jin, Xing; Zheng, Jian; Shi, Xiangsheng; Yan, Xiufeng; Wang, Yang

2018-01-01

Multidrug resistance (MDR) poses a great challenge to cancer therapy. It is difficult to inhibit the growth of MDR cancer due to its chemoresistance. Furthermore, MDR cancers are more likely to metastasize, causing a high mortality among cancer patients. In this study, a nanomedicine RGD-NPVs@MNPs/DOX was developed by encapsulating melanin nanoparticles (MNPs) and doxorubicin (DOX) inside RGD peptide (c(RGDyC))-modified nanoscale platelet vesicles (RGD-NPVs) to efficiently inhibit the growth and metastasis of drug-resistant tumors via a cancer cells and tumor vasculature dual-targeting strategy. Methods: The in vitro immune evasion potential and the targeting performance of RGD-NPVs@MNPs/DOX were examined using RAW264.7, HUVECs, MDA-MB-231 and MDA-MB-231/ADR cells lines. We also evaluated the pharmacokinetic behavior and the in vivo therapeutic performance of RGD-NPVs@MNPs/DOX using a MDA-MB-231/ADR tumor-bearing nude mouse model. Results: By taking advantage of the self-recognizing property of the platelet membrane and the conjugated RGD peptides, RGD-NPVs@MNPs/DOX was found to evade immune clearance and target the αvβ3 integrin on tumor vasculature and resistant breast tumor cells. Under irradiation with a NIR laser, RGD-NPVs@MNPs/DOX produced a multipronged effect, including reversal of cancer MDR, efficient killing of resistant cells by chemo-photothermal therapy, elimination of tumor vasculature for blocking metastasis, and long-lasting inhibition of the expressions of VEGF, MMP2 and MMP9 within the tumor. Conclusion: This versatile nanomedicine of RGD-NPVs@MNPs/DOX integrating unique biomimetic properties, excellent targeting performance, and comprehensive therapeutic strategies in one formulation might bring opportunities to MDR cancer therapy.

Silencing VDAC1 Expression by siRNA Inhibits Cancer Cell Proliferation and Tumor Growth In Vivo

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Tasleem Arif

2014-01-01

Full Text Available Alterations in cellular metabolism and bioenergetics are vital for cancer cell growth and motility. Here, the role of the mitochondrial protein voltage-dependent anion channel (VDAC1, a master gatekeeper regulating the flux of metabolites and ions between mitochondria and the cytoplasm, in regulating the growth of several cancer cell lines was investigated by silencing VDAC1 expression using small interfering RNA (siRNA. A single siRNA specific to the human VDAC1 sequence at nanomolar concentrations led to some 90% decrease in VDAC1 levels in the lung A549 and H358, prostate PC-3, colon HCT116, glioblastoma U87, liver HepG2, and pancreas Panc-1 cancer cell lines. VDAC1 silencing persisted 144 hours post-transfection and resulted in profound inhibition of cell growth in cancer but not in noncancerous cells, with up to 90% inhibition being observed over 5 days that was prolonged by a second transfection. Cells expressing low VDAC1 levels showed decreased mitochondrial membrane potential and adenoside triphosphate (ATP levels, suggesting limited metabolite exchange between mitochondria and cytosol. Moreover, cells silenced for VDAC1 expression showed decreased migration, even in the presence of the wound healing accelerator basic fibroblast growth factor (bFGF. VDAC1-siRNA inhibited cancer cell growth in a Matrigel-based assay in host nude mice. Finally, in a xenograft lung cancer mouse model, chemically modified VDAC1-siRNA not only inhibited tumor growth but also resulted in tumor regression. This study thus shows that VDAC1 silencing by means of RNA interference (RNAi dramatically inhibits cancer cell growth and tumor development by disabling the abnormal metabolic behavior of cancer cells, potentially paving the way for a more effective pipeline of anticancer drugs.

Exosome derived from epigallocatechin gallate treated breast cancer cells suppresses tumor growth by inhibiting tumor-associated macrophage infiltration and M2 polarization

International Nuclear Information System (INIS)

Jang, Ji-Young; Lee, Jong-Kuen; Jeon, Yoon-Kyung; Kim, Chul-Woo

2013-01-01

Tumor-associated macrophages (TAM) play an important role in tumor microenvironment. Particularly, M2 macrophages contribute to tumor progression, depending on the expression of NF-κB. Tumor-derived exosomes can modulate tumor microenvironment by transferring miRNAs to immune cells. Epigallocatechin gallate (EGCG) has well known anti-tumor effects; however, no data are available on the influence of EGCG on communication with cancer cells and TAM. Murine breast cancer cell lines, 4T1, was used for in vivo and ex vivo studies. Exosome was extracted from EGCG-treated 4T1 cells, and the change of miRNAs was screened using microarray. Tumor cells or TAM isolated from murine tumor graft were incubated with exosomes derived from EGCG-treated and/or miR-16 inhibitor-transfected 4T1 cells. Chemokines for monocytes (CSF-1 and CCL-2), cytokines both with high (IL-6 and TGF-β) and low (TNF-α) expression in M2 macrophages, and molecules in NF-κB pathway (IKKα and Iκ-B) were evaluated by RT-qPCR or western blot. EGCG suppressed tumor growth in murine breast cancer model, which was associated with decreased TAM and M2 macrophage infiltration. Expression of chemokine for monocytes (CSF-1 and CCL-2) were low in tumor cells from EGCG-treated mice, and cytokines of TAM was skewed from M2- into M1-like phenotype by EGCG as evidenced by decreased IL-6 and TGF-β and increased TNF-α. Ex vivo incubation of isolated tumor cells with EGCG inhibited the CSF-1 and CCL-2 expression. Ex vivo incubation of TAM with exosomes from EGCG-treated 4T1 cells led to IKKα suppression and concomitant I-κB accumulation; increase of IL-6 and TGF-β; and, decrease of TNF-α. EGCG up-regulated miR-16 in 4T1 cells and in the exosomes. Treatment of tumor cells or TAM with exosomes derived from EGCG-treated and miR-16-knock-downed 4T1 cells restored the above effects on chemokines, cytokines, and NF-κB pathway elicited by EGCG-treated exosomes. Our data demonstrate that EGCG up-regulates miR-16 in

Splenectomy inhibits non-small cell lung cancer growth by modulating anti-tumor adaptive and innate immune response

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Levy, Liran; Mishalian, Inbal; Bayuch, Rachel; Zolotarov, Lida; Michaeli, Janna; Fridlender, Zvi G

2015-01-01

It has been shown that inhibitors of the immune system reside in the spleen and inhibit the endogenous antitumor effects of the immune system. We hypothesized that splenectomy would inhibit the growth of relatively large non-small lung cancer (NSCLC) tumors by modulating the systemic inhibition of the immune system, and in particular Myeloid Derived Suppressor Cells (MDSC). The effect of splenectomy was evaluated in several murine lung cancer models. We found that splenectomy reduces tumor growth and the development of lung metastases, but only in advanced tumors. In immune-deficient NOD-SCID mice the effect of splenectomy on tumor growth and metastatic spread disappeared. Splenectomy significantly reduced the presence of MDSC, and especially monocytic-MDSC in the circulation and inside the tumor. Specific reduction of the CCR2+ subset of monocytic MDSC was demonstrated, and the importance of the CCL2-CCR2 axis was further shown by a marked reduction in CCL2 following splenectomy. These changes were followed by changes in the macrophages contents of the tumors to become more antitumorigenic, and by increased activation of CD8+ Cytotoxic T-cells (CTL). By MDSC depletion, and adoptive transfer of MDSCs, we demonstrated that the effect of splenectomy on tumor growth was substantially mediated by MDSC cells. We conclude that the spleen is an important contributor to tumor growth and metastases, and that splenectomy can blunt this effect by depletion of MDSC, changing the amount and characteristics of myeloid cells and enhancing activation of CTL. PMID:26137413

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

Verapamil inhibits tumor progression of chemotherapy-resistant pancreatic cancer side population cells

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ZHAO, LU; ZHAO, YUE; SCHWARZ, BETTINA; MYSLIWIETZ, JOSEF; HARTIG, ROLAND; CAMAJ, PETER; BAO, QI; JAUCH, KARL-WALTER; GUBA, MAKUS; ELLWART, JOACHIM WALTER; NELSON, PETER JON; BRUNS, CHRISTIANE JOSEPHINE

2016-01-01

Tumor side population (SP) cells display stem-like properties that can be modulated by treatment with the calcium channel blocker verapamil. Verapamil can enhance the cytotoxic effects of chemotherapeutic drugs and multi-drug resistance by targeting the transport function of the P-glycoprotein (P-gp). This study focused on the therapeutic potential of verapamil on stem-like SP tumor cells, and further investigated its chemosensitizing effects using L3.6pl and AsPC-1 pancreatic carcinoma models. As compared to parental L3.6pl cells (0.9±0.22%), L3.6pl gemcitabine-resistant cells (L3.6plGres) showed a significantly higher percentage of SP cells (5.38±0.99%) as detected by Hoechst 33342/FACS assays. The L3.6plGres SP cells showed stable gemcitabine resistance, enhanced colony formation ability and increased tumorigenicity. Verapamil effectively inhibited L3.6plGres and AsPC-1 SP cell proliferation in vitro. A pro-apoptotic effect of verapamil was observed in L3.6pl cells, but not in L3.6plGres cells, which was linked to their differential expression of P-gp and equilibrative nucleoside transporter-1 (ENT-1). In an orthotopic pancreatic cancer mouse model, both low and high dose verapamil was shown to substantially reduce L3.6plGres-SP cell tumor growth and metastasis, enhance tumor apoptosis, and reduce microvascular density. PMID:27177126

Pertussis toxin inhibits somatostatin-induced K+ conductance in human pituitary tumor cells

International Nuclear Information System (INIS)

Yamashita, N.; Kojima, I.; Shibuya, N.; Ogata, E.

1987-01-01

The effect of pertussis toxin on somatostatin-induced K + current was examined in dissociated human pituitary tumor cells obtained from two acromegalic patients. Somatostatin-induced hyperpolarization or K + current was observed in 20 of 23 cells in adenoma 1 and 10 of 11 cells in adenoma 2. After treatment with pertussis toxin for 24 h, these responses were completely suppressed (0/14 in adenoma, 1, 0/10 in adenoma 2). Spontaneous action potentials, K + , Na + , and Ca 2+ currents were well preserved after pertussis toxin treatment. When crude membrane fraction was incubated with [ 32 P]NAD, a 41K protein was ADP-ribosylated by pertussis toxin. Hormone release was inhibited by somatostatin and this inhibition was blocked by pertussis toxin treatment

Inhibition of tumor cell growth by Sigma1 ligand mediated translational repression

International Nuclear Information System (INIS)

Kim, Felix J.; Schrock, Joel M.; Spino, Christina M.; Marino, Jacqueline C.; Pasternak, Gavril W.

2012-01-01

Highlights: ► Sigma1 ligand treatment mediates decrease in tumor cell mass. ► Identification of a Sigma1 ligand with reversible translational repressor actions. ► Demonstration of a role for Sigma1 in cellular protein synthesis. -- Abstract: Treatment with sigma1 receptor (Sigma1) ligands can inhibit cell proliferation in vitro and tumor growth in vivo. However, the cellular pathways engaged in response to Sigma1 ligand treatment that contribute to these outcomes remain largely undefined. Here, we show that treatment with putative antagonists of Sigma1 decreases cell mass. This effect corresponds with repressed cap-dependent translation initiation in multiple breast and prostate cancer cell lines. Sigma1 antagonist treatment suppresses phosphorylation of translational regulator proteins p70S6K, S6, and 4E-BP1. RNAi-mediated knockdown of Sigma1 also results in translational repression, consistent with the effects of antagonist treatment. Sigma1 antagonist mediated translational repression and decreased cell size are both reversible. Together, these data reveal a role for Sigma1 in tumor cell protein synthesis, and demonstrate that small molecule Sigma1 ligands can be used as modulators of protein translation.

Inhibition of pancreatic tumoral cells by snake venom disintegrins.

Science.gov (United States)

Lucena, Sara; Castro, Roberto; Lundin, Courtney; Hofstetter, Amanda; Alaniz, Amber; Suntravat, Montamas; Sánchez, Elda Eliza

2015-01-01

Pancreatic cancer often has a poor prognosis, even when diagnosed early. Pancreatic cancer typically spreads rapidly and is rarely detected in its early stages, which is a major reason it is a leading cause of cancer death. Signs and symptoms may not appear until pancreatic cancer is quite advanced, and complete surgical removal is not possible. Furthermore, pancreatic cancer responds poorly to most chemotherapeutic agents. The importance of integrins in several cell types that affect tumor progression has made them an appealing target for cancer therapy. Some of the proteins found in the snake venom present a great potential as anti-tumor agents. In this study, we summarize the activity of two integrins antagonist, recombinant disintegrins mojastin 1 and viridistatin 2, on human pancreatic carcinoma cell line (BXPC-3). Both recombinant disintegrins inhibited some essential aspects of the metastasis process such as proliferation, adhesion, migration, and survival through apoptosis, making these proteins prominent candidates for the development of drugs for the treatment of pancreatic cancer. Copyright © 2014 Elsevier Ltd. All rights reserved.

Increased expression of IRF8 in tumor cells inhibits the generation of Th17 cells and predicts unfavorable survival of diffuse large B cell lymphoma patients.

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Zhong, Weijie; Xu, Xin; Zhu, Zhigang; Du, Qinghua; Du, Hong; Yang, Li; Ling, Yanying; Xiong, Huabao; Li, Qingshan

2017-07-25

The immunological pathogenesis of diffuse large B cell lymphoma (DLBCL) remains elusive. Searching for new prognostic markers of DLBCL is a crucial focal point for clinical scientists. The aim of the present study was to examine the prognostic value of interferon regulatory factor 8 (IRF8) expression and its effect on the development of Th17 cells in the tumor microenvironment of DLBCL patients. Flow cytometry, immunohistochemistry, and quantitative real-time PCR were used to detect the distribution of Th17 cells and related cytokines and IRF8 in tumor tissues from DLBCL patients. Two DLBCL cell lines (OCI-LY10 and OCI-LY1) with IRF8 knockdown or overexpression and two human B lymphoblast cell lines were co-cultured with peripheral blood mononuclear cells (PBMCs) in vitro to determine the effect of IRF8 on the generation of Th17 cells. Quantitative real-time PCR and Western blotting were used to investigate the involvement of retinoic acid receptor-related orphan receptor gamma t (RORγt) in the effect of IRF8 on Th17 cell generation. The survival of 67 DLBCL patients was estimated using the Kaplan-Meier method and log-rank analysis. The percentage of Th17 cells was lower in DLBCL tumor tissues than in PBMCs and corresponding adjacent benign tissues. Relative expression of interleukin (IL)-17A was lower, whereas that of interferon (IFN)-γ was higher in tumor tissues than in benign tissues. Co-culture with DLBCL cell lines inhibited the generation of Th17 cells in vitro. IRF8 upregulation was detected in DLBCL tumor tissues, and it was associated with decreased DLBCL patient survival. Investigation of the underlying mechanism suggested that IRF8 upregulation in DLBCL, through an unknown mechanism, inhibited Th17 cell generation by suppressing RORγt in neighboring CD4+ T cells. Tumor cells may express soluble or membrane-bound factors that inhibit the expression of RORγt in T cells within the tumor microenvironment. Our findings suggest that IRF8 expression could

Novel small molecule drugs inhibit tumor cell metabolism and show potent anti-tumorigenic potential

DEFF Research Database (Denmark)

Trojel-Hansen, Christina; Erichsen, Kamille Dumong; Christensen, Mette Knak

2011-01-01

oxyphenisatine analogs TOP001 and TOP216 exert their anti-cancer effect by affecting tumor cell metabolism and inducing intracellular amino acid deprivation, leading to a block of cell proliferation. GCN2-mediated phosphorylation of eIF2a as well as mTOR pathway inhibition supports the above notion. In addition...

Novel small molecule drugs inhibit tumor cell metabolism and show potent anti-tumorigenic potential

DEFF Research Database (Denmark)

Trojel-Hansen, Christina; Erichsen, Kamille Dumong; Christensen, Mette Knak

2011-01-01

oxyphenisatine analogs TOP001 and TOP216 exert their anti-cancer effect by affecting tumor cell metabolism and inducing intracellular amino acid deprivation, leading to a block of cell proliferation. GCN2-mediated phosphorylation of eIF2α as well as mTOR pathway inhibition supports the above notion. In addition...

Antihelminthic drug niclosamide inhibits CIP2A and reactivates tumor suppressor protein phosphatase 2A in non-small cell lung cancer cells.

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Kim, Myeong-Ok; Choe, Min Ho; Yoon, Yi Na; Ahn, Jiyeon; Yoo, Minjin; Jung, Kwan-Young; An, Sungkwan; Hwang, Sang-Gu; Oh, Jeong Su; Kim, Jae-Sung

2017-11-15

Protein phosphatase 2A (PP2A) is a critical tumor suppressor complex responsible for the inactivation of various oncogenes. Recently, PP2A reactivation has emerged asan anticancer strategy. Cancerous inhibitor of protein phosphatase 2A (CIP2A), an endogenous inhibitor of PP2A, is upregulated in many cancer cells, including non-small cell lung cancer (NSCLC) cells. We demonstrated that the antihelminthic drug niclosamide inhibited the expression of CIP2A and reactivated the tumor suppressor PP2A in NSCLC cells. We performed a drug-repurposing screen and identified niclosamide asa CIP2A suppressor in NSCLC cells. Niclosamide inhibited cell proliferation, colony formation, and tumor sphere formation, and induced mitochondrial dysfunction through increased mitochondrial ROS production in NSCLC cells; however, these effects were rescued by CIP2A overexpression, which indicated that the antitumor activity of niclosamide was dependent on CIP2A. We found that niclosamide increased PP2A activity through CIP2A inhibition, which reduced the phosphorylation of several oncogenic proteins. Moreover, we found that a niclosamide analog inhibited CIP2A expression and increased PP2A activity in several types of NSCLC cells. Finally, we showed that other well-known PP2A activators, including forskolin and FTY720, did not inhibit CIP2A and that their activities were not dependent on CIP2A. Collectively, our data suggested that niclosamide effectively suppressed CIP2A expression and subsequently activated PP2A in NSCLC cells. This provided strong evidence for the potential use of niclosamide asa PP2A-activating drug in the clinical treatment of NSCLC. Copyright © 2017 Elsevier Inc. All rights reserved.

Prostate tumor-induced angiogenesis is blocked by exosomes derived from menstrual stem cells through the inhibition of reactive oxygen species

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Alcayaga-Miranda, Francisca; González, Paz L.; Lopez-Verrilli, Alejandra; Varas-Godoy, Manuel; Aguila-Díaz, Carolina; Contreras, Luis; Khoury, Maroun

2016-01-01

Mesenchymal stem cells (MSCs) secrete exosomes that are capable of modifying the tumor environment through different mechanisms including changes in the cancer-cell secretome. This activity depends on their cargo content that is largely defined by their cellular origin. Endometrial cells are fine regulators of the angiogenic process during the menstrual cycle that includes an angiostatic condition that is associated with the end of the cycle. Hence, we studied the angiogenic activity of menstrual stem cells (MenSCs)-secreted exosomes on prostate PC3 tumor cells. Our results showed that exosomes induce a reduction in VEGF secretion and NF-κB activity. Lower reactive oxygen species (ROS) production in exosomes-treated cells was detected by the DCF method, suggesting that the inhibition of the intracellular ROS impacts both NF-κB and VEGF pathways. We confirmed using tubule formation and plug transplantation assays that MenSCs-exosomes suppress the secretion of pro-angiogenic factors by the PC3 cells in a ROS-dependent manner. The inhibition of the tumor angiogenesis and, consequently, the tumor growth was also confirmed using a xenograft mouse model. Additionally, the anti-tumoral effect was associated with a reduction of tumor hemoglobin content, vascular density and inhibition of VEGF and HIF-1α expression. Importantly, we demonstrate that the exosomes anti-angiogenic effect is specific to the menstrual cell source, as bone marrow MSCs-derived exosomes showed an opposite effect on the VEGF and bFGF expression in tumor cells. Altogether, our results indicate that MenSCs-derived exosomes acts as blockers of the tumor-induced angiogenesis and therefore could be suitable for anti-cancer therapies. PMID:27286448

Silibinin inhibits migration and invasion of the rhabdoid tumor G401 cell line via inactivation of the PI3K/Akt signaling pathway.

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Li, Yumei; Zhang, Chunmei; Cai, Danfeng; Chen, Congde; Mu, Dongmei

2017-12-01

Rhabdoid tumors, which tend to occur prior to the age of 2 years, are one of the most aggressive malignancies and have a poor prognosis due to the frequency of metastasis. Silibinin, a natural extract, has been approved as a potential tumor suppressor in various studies, however, whether or not it also exerts its antitumor capacity in rhabdoid tumors, particularly with regards to tumor migration and invasion, is unclear. The rhabdoid tumor G401 cell line was used in the present in vitro study. An MTT assay was used to assess the cytotoxicity of silibinin on G401 cells, cell migration was studied using a wound healing assay and a Transwell migration assay, and cell invasion was determined using a Transwell invasion assay. The underlying mechanism in silibinin inhibited cell migration and invasion was investigated by western blot analysis and further confirmed using a specific inhibitor. Experimental results demonstrated that high doses of silibinin suppressed cell viability, and that low doses of silibinin inhibited cell migration and invasion without affecting cell proliferation. The phosphatidylinositol 3-kinase/protein kinase B (PI3K/Akt) signaling pathway was involved in the silibinin-induced inhibition of metastasis. Silibinin inactivated the PI3K/Akt pathway, and inhibited cell migration and invasion, an effect that was further enhanced when LY294002, a classic PI3K inhibitor, was used concurrently. In general, silibinin inhibits migration and invasion of the rhabdoid tumor G401 cell line via inactivation of the PI3K/Akt signaling pathway and may be a potential chemotherapeutic drug to combat rhabdoid tumors in the future.

Electroporation driven delivery of both an IL-12 expressing plasmid and cisplatin synergizes to inhibit B16 melanoma tumor growth through an NK cell mediated tumor killing mechanism.

Science.gov (United States)

Kim, Ha; Sin, Jeong-Im

2012-11-01

Combined therapy using chemotherapeutic drugs and immunotherapeutics offers some promise for treating patients with cancer. In this study, we evaluated whether cisplatin delivered by intratumoral (IT)-electroporation (EP) might enhance antitumor activity against established B16 melanoma and whether further addition of intramuscular (IM)-EP of IL-12 cDNA to IT-EP of cisplatin might augment antitumor therapeutic activity, with a focus on the underlining antitumor mechanism(s). When tumor (7 mm)-bearing animals were treated locally with cisplatin by IT-EP, they showed tumor growth inhibition significantly more than those without IT-EP. Moreover, IL-12 cDNA delivered by IM-EP was also able to inhibit tumor growth significantly more than control vector delivery. This tumor growth inhibition was mediated by NK cells, but not CD4+ T or CD8+ T cells, as determined by immune cell subset depletion and IFN-γ induction. Moreover, concurrent therapy using IT-EP of cisplatin plus IM-EP of IL-12 cDNA displayed antitumor therapeutic synergy. This therapeutic synergy appeared to be mediated by increased sensitivity of cisplatin-treated tumors to NK cell-mediated tumor killing. Taken together, these data support that cisplatin delivery by IT-EP plus IL-12 gene delivery by IM-EP are more effective at inducing antitumor therapeutic responses through increased sensitivity of cisplatin-treated tumors to NK cell-mediated tumor killing. This combined approach might have some implication for treating melanoma in patients.

Paeoniflorin inhibits cell growth and induces cell cycle arrest through inhibition of FoxM1 in colorectal cancer cells.

Science.gov (United States)

Yue, Meng; Li, Shiquan; Yan, Guoqiang; Li, Chenyao; Kang, Zhenhua

2018-01-01

Paeoniflorin (PF) exhibits tumor suppressive functions in a variety of human cancers. However, the function of PF and molecular mechanism in colorectal cancer are elusive. In the present study, we investigated whether PF could exert its antiproliferative activity, anti-migration, and anti-invasive function in colorectal cancer cells. We found that PF inhibited cell growth and induced apoptosis and blocked cell cycle progression in the G0/G1 phase in colorectal cancer cells. Moreover, we found that PF suppressed cell migration and invasion in colorectal cancer cells. FoxM1 has been reported to play an important oncogenic role in human cancers. We also determine whether PF inhibited the expression of FoxM1, leading to its anti-cancer activity. We found that PF treatment in colorectal cancer cells resulted in down-regulation of FoxM1. The rescue experiments showed that overexpression of FoxM1 abrogated the tumor suppressive function induced by PF treatment. Notably, depletion of FoxM1 promoted the anti-tumor activity of PF in colorectal cancer cells. Therefore, inhibition of FoxM1 could participate in the anti-tumor activity of PF in colorectal cancer cells.

Downregulation of HDAC9 inhibits cell proliferation and tumor formation by inducing cell cycle arrest in retinoblastoma

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Zhang, Yiting; Wu, Dan; Xia, Fengjie; Xian, Hongyu; Zhu, Xinyue [Medical School of Nanjing University, Department of Ophthalmology, Jinling Hospital, Nanjing, 210002 (China); Cui, Hongjuan, E-mail: hcui@swu.edu.cn [State Key Laboratory of Silkworm Genome Biology, Institute of Sericulture and Systems Biology, Southwest University, Chongqing, 400716 (China); Huang, Zhenping, E-mail: huangzhenping19633@163.com [Medical School of Nanjing University, Department of Ophthalmology, Jinling Hospital, Nanjing, 210002 (China)

2016-04-29

Histone deacetylase 9 (HDAC9) is a member of class II HDACs, which regulates a wide variety of normal and abnormal physiological functions. Recently, HDAC9 has been found to be overexpressed in some types of human cancers. However, the role of HDAC9 in retinoblastoma remains unclear. In this study, we found that HDAC9 was commonly expressed in retinoblastoma tissues and HDAC9 was overexpressed in prognostically poor retinoblastoma patients. Through knocking down HDAC9 in Y79 and WERI-Rb-1 cells, the expression level of HDAC9 was found to be positively related to cell proliferation in vitro. Further investigation indicated that knockdown HDAC9 could significantly induce cell cycle arrest at G1 phase in retinoblastoma cells. Western blot assay showed downregulation of HDAC9 could significantly decrease cyclin E2 and CDK2 expression. Lastly, xenograft study in nude mice showed that downregulation of HDAC9 inhibited tumor growth and development in vivo. Therefore, our results suggest that HDAC9 could serve as a novel potential therapeutic target in the treatment of retinoblastoma. - Highlights: • High expression of HDAC9 correlates with poor patient prognosis. • Downregulation of HDAC9 inhibits cell proliferation in retinoblastoma cells. • Downregulation of HDAC9 induces cell cycle arrest at G1 phase in retinoblastoma cells. • Downregulation of HDAC9 suppresses tumor growth in nude mice.

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.

HAMLET (human alpha-lactalbumin made lethal to tumor cells) triggers autophagic tumor cell death.

Science.gov (United States)

Aits, Sonja; Gustafsson, Lotta; Hallgren, Oskar; Brest, Patrick; Gustafsson, Mattias; Trulsson, Maria; Mossberg, Ann-Kristin; Simon, Hans-Uwe; Mograbi, Baharia; Svanborg, Catharina

2009-03-01

HAMLET, a complex of partially unfolded alpha-lactalbumin and oleic acid, kills a wide range of tumor cells. Here we propose that HAMLET causes macroautophagy in tumor cells and that this contributes to their death. Cell death was accompanied by mitochondrial damage and a reduction in the level of active mTOR and HAMLET triggered extensive cytoplasmic vacuolization and the formation of double-membrane-enclosed vesicles typical of macroautophagy. In addition, HAMLET caused a change from uniform (LC3-I) to granular (LC3-II) staining in LC3-GFP-transfected cells reflecting LC3 translocation during macroautophagy, and this was blocked by the macroautophagy inhibitor 3-methyladenine. HAMLET also caused accumulation of LC3-II detected by Western blot when lysosomal degradation was inhibited suggesting that HAMLET caused an increase in autophagic flux. To determine if macroautophagy contributed to cell death, we used RNA interference against Beclin-1 and Atg5. Suppression of Beclin-1 and Atg5 improved the survival of HAMLET-treated tumor cells and inhibited the increase in granular LC3-GFP staining. The results show that HAMLET triggers macroautophagy in tumor cells and suggest that macroautophagy contributes to HAMLET-induced tumor cell death.

Silibinin inhibits accumulation of myeloid-derived suppressor cells and tumor growth of murine breast cancer

International Nuclear Information System (INIS)

Forghani, Parvin; Khorramizadeh, Mohammad R; Waller, Edmund K

2014-01-01

Myeloid-derived suppressor cells (MDSC)s increase in blood and accumulate in the tumor microenvironment of tumor-bearing animals, contributing to immune suppression in cancer. Silibinin, a natural flavonoid from the seeds of milk thistle, has been developed as an anti-inflammatory agent and supportive care agent to reduce the toxicity of cancer chemotherapy. The goals of this study were to evaluate the effect of silibinin on MDSCs in tumor-bearing mice and antitumor activity of silibinin in a mouse model of breast cancer. 4T1 luciferase-transfected mammary carcinoma cells were injected into in the mammary fat pad female BALB/c mice, and female CB17-Prkdc Scid/J mice. Silibinin treatment started on day 4 or day 14 after tumor inoculation continued every other day. Tumor growth was monitored by bioluminescent imaging (BLI) measuring total photon flux. Flow cytometry measured total leukocytes, CD11b + Gr-1 + MDSC, and T cells in the blood and tumors of tumor-bearing mice. The effects of silibinin on 4T1 cell viability in vitro were measured by BLI. Treatment with silibinin increased overall survival in mice harboring tumors derived from the 4T1-luciferase breast cancer cell line, and reduced tumor volumes and numbers of CD11b + Gr-1 + MDSCs in the blood and tumor, and increased the content of T cells in the tumor microenvironment. Silibinin failed to inhibit tumor growth in immunocompromised severe combined immunodeficiency mice, supporting the hypothesis that anticancer effect of silibinin is immune-mediated. The antitumor activity of silibinin requires an intact host immune system and is associated with decreased accumulation of blood and tumor-associated MDSCs

Scoparone exerts anti-tumor activity against DU145 prostate cancer cells via inhibition of STAT3 activity.

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Jeong-Kook Kim

Full Text Available Scoparone, a natural compound isolated from Artemisia capillaris, has been used in Chinese herbal medicine to treat neonatal jaundice. Signal transducer and activator of transcription 3 (STAT3 contributes to the growth and survival of many human tumors. This study was undertaken to investigate the anti-tumor activity of scoparone against DU145 prostate cancer cells and to determine whether its effects are mediated by inhibition of STAT3 activity. Scoparone inhibited proliferation of DU145 cells via cell cycle arrest in G1 phase. Transient transfection assays showed that scoparone repressed both constitutive and IL-6-induced transcriptional activity of STAT3. Western blot and quantitative real-time PCR analyses demonstrated that scoparone suppressed the transcription of STAT3 target genes such as cyclin D1, c-Myc, survivin, Bcl-2, and Socs3. Consistent with this, scoparone decreased phosphorylation and nuclear accumulation of STAT3, but did not reduce phosphorylation of janus kinase 2 (JAK2 or Src, the major upstream kinases responsible for STAT3 activation. Moreover, transcriptional activity of a constitutively active mutant of STAT3 (STAT3C was inhibited by scoparone, but not by AG490, a JAK2 inhibitor. Furthermore, scoparone treatment suppressed anchorage-independent growth in soft agar and tumor growth of DU145 xenografts in nude mice, concomitant with a reduction in STAT3 phosphorylation. Computational modeling suggested that scoparone might bind the SH2 domain of STAT3. Our findings suggest that scoparone elicits an anti-tumor effect against DU145 prostate cancer cells in part through inhibition of STAT3 activity.

Inhibition of tumor angiogenesis and tumor growth by the DSL domain of human Delta-like 1 targeted to vascular endothelial cells.

Science.gov (United States)

Zhao, Xing-Cheng; Dou, Guo-Rui; Wang, Li; Liang, Liang; Tian, Deng-Mei; Cao, Xiu-Li; Qin, Hong-Yan; Wang, Chun-Mei; Zhang, Ping; Han, Hua

2013-07-01

The growth of solid tumors depends on neovascularization. Several therapies targeting tumor angiogenesis have been developed. However, poor response in some tumors and emerging resistance necessitate further investigations of new drug targets. Notch signal pathway plays a pivotal role in vascular development and tumor angiogenesis. Either blockade or forced activation of this pathway can inhibit angiogenesis. As blocking Notch pathway results in the formation of vascular neoplasm, activation of Notch pathway to prevent tumor angiogenesis might be an alternative choice. However, an in vivo deliverable reagent with highly efficient Notch-activating capacity has not been developed. Here, we generated a polypeptide, hD1R, which consists of the Delta-Serrate-Lag-2 fragment of the human Notch ligand Delta-like 1 and an arginine-glycine-aspartate (RGD) motif targeting endothelial cells (ECs). We showed that hD1R could bind to ECs specifically through its RGD motif and effectively triggered Notch signaling in ECs. We demonstrated both in vitro and in vivo that hD1R inhibited angiogenic sprouting and EC proliferation. In tumor-bearing mice, the injection of hD1R effectively repressed tumor growth, most likely through increasing tumor hypoxia and tissue necrosis. The amount and width of vessels reduced remarkably in tumors of mice treated with hD1R. Moreover, vessels in tumors of mice treated with hD1R recruited more NG2(+) perivascular cells and were better perfused. Combined application of hD1R and chemotherapy with cisplatin and teniposide revealed that these two treatments had additive antitumor effects. Our study provided a new strategy for antiangiogenic tumor therapy.

Inhibition of Tumor Angiogenesis and Tumor Growth by the DSL Domain of Human Delta-Like 1 Targeted to Vascular Endothelial Cells

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Xing-Cheng Zhao

2013-07-01

Full Text Available The growth of solid tumors depends on neovascularization. Several therapies targeting tumor angiogenesis have been developed. However, poor response in some tumors and emerging resistance necessitate further investigations of newdrug targets. Notch signal pathway plays a pivotal role in vascular development and tumor angiogenesis. Either blockade or forced activation of this pathway can inhibit angiogenesis. As blocking Notch pathway results in the formation of vascular neoplasm, activation of Notch pathway to prevent tumor angiogenesis might be an alternative choice. However, an in vivo deliverable reagent with highly efficient Notch-activating capacity has not been developed. Here, we generated a polypeptide, hD1R, which consists of the Delta-Serrate-Lag-2 fragment of the human Notch ligand Delta-like 1 and an arginine-glycine-aspartate (RGD motif targeting endothelial cells (ECs. We showed that hD1R could bind to ECs specifically through its RGD motif and effectively triggered Notch signaling in ECs. We demonstrated both in vitro and in vivo that hD1R inhibited angiogenic sprouting and EC proliferation. In tumor-bearing mice, the injection of hD1R effectively repressed tumor growth, most likely through increasing tumor hypoxia and tissue necrosis. The amount and width of vessels reduced remarkably in tumors of mice treated with hD1R. Moreover, vessels in tumors of mice treated with hD1R recruited more NG2+ perivascular cells and were better perfused. Combined application of hD1R and chemotherapy with cisplatin and teniposide revealed that these two treatments had additive antitumor effects. Our study provided a new strategy for antiangiogenic tumor therapy.

The inhibition effect of 211At-Te colloid and Na211 at injections on murine Ehrlich ascites tumor cells

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Wang Juan; Wang Xizhong; Zhang Jiazao

1992-01-01

Na 211 At and 211 At-Te colloid injections are prepared. It has been demonstrated that the 211 At-Te colloid is stable in vivo and in vitro, and can be applied in the study of biology and medicine. In the report, the model of Murine Ehrlich Ascites Cells cultured in vivo and in vitro is elected for a series of experiments. It has been proved that Na 211 At and 211 At-Te colloid injections possess an inhibition effect on tumor cells. The inhibition effect was expressed in surviving of the mice and inhibiting growth of tumor as well as the changes of enzyme activity. Meanwhile, it was also noticed that Na 211 At and 211 At-Te colloid injections of various dose inhibited the absorb of pyrimidine nucleosides in Murine Ehrlich Ascites Cells. And the effect is not reversible. It is closely related to the dose administrated and 50% inhibition rate needs about 1.48 x 10 5 Bq/ml culture

Bauhinia variegata candida Fraction Induces Tumor Cell Death by Activation of Caspase-3, RIP, and TNF-R1 and Inhibits Cell Migration and Invasion In Vitro

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K. M. Santos

2018-01-01

Full Text Available Metastasis remains the most common cause of death in cancer patients. Inhibition of metalloproteinases (MMPs is an interesting approach to cancer therapy because of their role in the degradation of extracellular matrix (ECM, cell-cell, and cell-ECM interactions, modulating key events in cell migration and invasion. Herein, we show the cytotoxic and antimetastatic effects of the third fraction (FR3 from Bauhinia variegata candida (Bvc stem on human cervical tumor cells (HeLa and human peripheral blood mononuclear cells (PBMCs. FR3 inhibited MMP-2 and MMP-9 activity, indicated by zymogram. This fraction was cytotoxic to HeLa cells and noncytotoxic to PBMCs and decreased HeLa cell migration and invasion. FR3 is believed to stimulate extrinsic apoptosis together with necroptosis, assessed by western blotting. FR3 inhibited MMP-2 activity in the HeLa supernatant, differently from the control. The atomic mass spectrometry (ESI-MS characterization suggested the presence of glucopyranosides, D-pinitol, fatty acids, and phenolic acid. These findings provide insight suggesting that FR3 contains components with potential tumor-selective cytotoxic action in addition to the action on the migration of tumor cells, which may be due to inhibition of MMPs.

Targeting tumor multicellular aggregation through IGPR-1 inhibits colon cancer growth and improves chemotherapy.

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Woolf, N; Pearson, B E; Bondzie, P A; Meyer, R D; Lavaei, M; Belkina, A C; Chitalia, V; Rahimi, N

2017-09-18

Adhesion to extracellular matrix (ECM) is crucially important for survival of normal epithelial cells as detachment from ECM triggers specific apoptosis known as anoikis. As tumor cells lose the requirement for anchorage to ECM, they rely on cell-cell adhesion 'multicellular aggregation' for survival. Multicellular aggregation of tumor cells also significantly determines the sensitivity of tumor cells to the cytotoxic effects of chemotherapeutics. In this report, we demonstrate that expression of immunoglobulin containing and proline-rich receptor-1 (IGPR-1) is upregulated in human primary colon cancer. Our study demonstrates that IGPR-1 promotes tumor multicellular aggregation, and interfering with its adhesive function inhibits multicellular aggregation and, increases cell death. IGPR-1 supports colon carcinoma tumor xenograft growth in mouse, and inhibiting its activity by shRNA or blocking antibody inhibits tumor growth. More importantly, IGPR-1 regulates sensitivity of tumor cells to the chemotherapeutic agent, doxorubicin/adriamycin by a mechanism that involves doxorubicin-induced AKT activation and phosphorylation of IGPR-1 at Ser220. Our findings offer novel insight into IGPR-1's role in colorectal tumor growth, tumor chemosensitivity, and as a possible novel anti-cancer target.

Isoginkgetin inhibits tumor cell invasion by regulating phosphatidylinositol 3-kinase/Akt-dependent matrix metalloproteinase-9 expression.

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Yoon, Sang-Oh; Shin, Sejeong; Lee, Ho-Jae; Chun, Hyo-Kon; Chung, An-Sik

2006-11-01

Matrix metalloproteinase (MMP)-9 plays a key role in tumor invasion. Inhibitors of MMP-9 were screened from Metasequoia glyptostroboides (Dawn redwood) and one potent inhibitor, isoginkgetin, a biflavonoid, was identified. Noncytotoxic levels of isoginkgetin decreased MMP-9 production profoundly, but up-regulated the level of tissue inhibitor of metalloproteinase (TIMP)-1, an inhibitor of MMP-9, in HT1080 human fibrosarcoma cells. The major mechanism of Ras-dependent MMP-9 production in HT1080 cells was phosphatidylinositol 3-kinase (PI3K)/Akt/nuclear factor-kappaB (NF-kappaB) activation. Expression of dominant-active H-Ras and p85 (a subunit of PI3K) increased MMP-9 activity, whereas dominant-negative forms of these molecules decreased the level of MMP-9. H-Ras did not increase MMP-9 in the presence of a PI3K inhibitor, LY294002, and a NF-kappaB inhibitor, SN50. Further studies showed that isoginkgetin regulated MMP-9 production via PI3K/Akt/NF-kappaB pathway, as evidenced by the findings that isoginkgetin inhibited activities of both Akt and NF-kappaB. PI3K/Akt is a well-known key pathway for cell invasion, and isoginkgetin inhibited HT1080 tumor cell invasion substantially. Isoginkgetin was also quite effective in inhibiting the activities of Akt and MMP-9 in MDA-MB-231 breast carcinomas and B16F10 melanoma. Moreover, isoginkgetin treatment resulted in marked decrease in invasion of these cells. In summary, PI3K/Akt is a major pathway for MMP-9 expression and isoginkgetin markedly decreased MMP-9 expression and invasion through inhibition of this pathway. This suggests that isoginkgetin could be a potential candidate as a therapeutic agent against tumor invasion.

Dioscin inhibits colon tumor growth and tumor angiogenesis through regulating VEGFR2 and AKT/MAPK signaling pathways

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Tong, Qingyi [Regenerative Medicine Research Center, State Key Laboratory of Biotherapy and Cancer Center, West China Hospital, Sichuan University, Chengdu, Sichuan 610041 (China); Qing, Yong, E-mail: qingyongxy@yahoo.co.jp [Department of Pharmacology, West China School of Pharmacy, Sichuan University, Chengdu, Sichuan 610041 (China); Wu, Yang [State Key Laboratory of Biotherapy and Cancer Center, West China Hospital, Sichuan University, Chengdu, Sichuan 610041 (China); Hu, Xiaojuan; Jiang, Lei [Department of Pharmacology, West China School of Pharmacy, Sichuan University, Chengdu, Sichuan 610041 (China); Wu, Xiaohua, E-mail: wuxh@scu.edu.cn [Regenerative Medicine Research Center, State Key Laboratory of Biotherapy and Cancer Center, West China Hospital, Sichuan University, Chengdu, Sichuan 610041 (China)

2014-12-01

Dioscin has shown cytotoxicity against cancer cells, but its in vivo effects and the mechanisms have not elucidated yet. The purpose of the current study was to assess the antitumor effects and the molecular mechanisms of dioscin. We showed that dioscin could inhibit tumor growth in vivo and has no toxicity at the test condition. The growth suppression was accompanied by obvious blood vessel decrease within solid tumors. We also found dioscin treatment inhibited the proliferation of cancer and endothelial cell lines, and most sensitive to primary cultured human umbilical vein endothelial cells (HUVECs). What's more, analysis of HUVECs migration, invasion, and tube formation exhibited that dioscin has significantly inhibitive effects to these actions. Further analysis of blood vessel formation in the matrigel plugs indicated that dioscin could inhibit VEGF-induced blood vessel formation in vivo. We also identified that dioscin could suppress the downstream protein kinases of VEGFR2, including Src, FAK, AKT and Erk1/2, accompanied by the increase of phosphorylated P38MAPK. The results potently suggest that dioscin may be a potential anticancer drug, which efficiently inhibits angiogenesis induced by VEGFR2 signaling pathway as well as AKT/MAPK pathways. - Highlights: • Dioscin inhibits tumor growth in vivo and does not exhibit any toxicity. • Dioscin inhibits angiogenesis within solid tumors. • Dioscin inhibits the proliferation, migration, invasion, and tube formation of HUVECs. • Dioscin inhibits VEGF–induced blood vessel formation in vivo. • Dioscin inhibits VEGFR2 signaling pathway as well as AKT/MAPK pathway.

Potent inhibition of rhabdoid tumor cells by combination of flavopiridol and 4OH-tamoxifen

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Cimica, Velasco; Smith, Melissa E; Zhang, Zhikai; Mathur, Deepti; Mani, Sridhar; Kalpana, Ganjam V

2010-01-01

Rhabdoid Tumors (RTs) are highly aggressive pediatric malignancies with poor prognosis. There are currently no standard or effective treatments for RTs in part because treatments are not designed to specifically target these tumors. Our previous studies indicated that targeting the cyclin/cdk pathway is a novel therapeutic strategy for RTs and that a pan-cdk inhibitor, flavopiridol, inhibits RT growth. Since the toxicities and narrow window of activity associated with flavopiridol may limit its clinical use, we tested the effect of combining flavopiridol with 4-hydroxy-Tamoxifen (4OH-Tam) in order to reduce the concentration of flavopiridol needed for inhibition of RTs. The effects of flavopiridol, 4OH-Tam, and their combination on RT cell cycle regulation and apoptosis were assessed by: i) cell survival assays, ii) FACS analysis, iii) caspase activity assays, and iv) immunoblot analysis. Furthermore, the role of p53 in flavopiridol- and 4OH-Tam-mediated induction of cell cycle arrest and apoptosis was characterized using RNA interference (siRNA) analysis. The effect of p53 on flavopiridol-mediated induction of caspases 2, 3, 8 and 9 was also determined. We found that the combination of flavopiridol and 4OH-Tam potently inhibited the growth of RT cells. Low nanomolar concentrations of flavopiridol induced G 2 arrest, which was correlated to down-modulation of cyclin B1 and up-regulation of p53. Addition of 4OH-Tam did not affect flavopiridol-mediated G 2 arrest, but enhanced caspase 3,7-mediated apoptosis induced by the drug. Abrogation of p53 by siRNA abolished flavopiridol-induced G 2 arrest, but enhanced flavopiridol- (but not 4OH-Tam-) mediated apoptosis, by enhancing caspase 2 and 3 activities. Combining flavopiridol with 4OH-Tam potently inhibited the growth of RT cells by increasing the ability of either drug alone to induce caspases 2 and 3 thereby causing apoptosis. The potency of flavopiridol was enhanced by abrogation of p53. Our results warrant further

Potent inhibition of rhabdoid tumor cells by combination of flavopiridol and 4OH-tamoxifen

Energy Technology Data Exchange (ETDEWEB)

Cimica, Velasco; Smith, Melissa E; Zhang, Zhikai; Mathur, Deepti [Department of Genetics, Albert Einstein College of Medicine, 1300 Morris Park Avenue, Bronx, New York 10461 (United States); Mani, Sridhar [Department of Genetics, Albert Einstein College of Medicine, 1300 Morris Park Avenue, Bronx, New York 10461 (United States); Department of Medicine, Albert Einstein College of Medicine, 1300 Morris Park Avenue, Bronx, New York 10461 (United States); Albert Einstein Cancer Center, Albert Einstein College of Medicine, 1300 Morris Park Avenue, Bronx, New York 10461 (United States); Kalpana, Ganjam V [Department of Genetics, Albert Einstein College of Medicine, 1300 Morris Park Avenue, Bronx, New York 10461 (United States); Albert Einstein Cancer Center, Albert Einstein College of Medicine, 1300 Morris Park Avenue, Bronx, New York 10461 (United States)

2010-11-19

Rhabdoid Tumors (RTs) are highly aggressive pediatric malignancies with poor prognosis. There are currently no standard or effective treatments for RTs in part because treatments are not designed to specifically target these tumors. Our previous studies indicated that targeting the cyclin/cdk pathway is a novel therapeutic strategy for RTs and that a pan-cdk inhibitor, flavopiridol, inhibits RT growth. Since the toxicities and narrow window of activity associated with flavopiridol may limit its clinical use, we tested the effect of combining flavopiridol with 4-hydroxy-Tamoxifen (4OH-Tam) in order to reduce the concentration of flavopiridol needed for inhibition of RTs. The effects of flavopiridol, 4OH-Tam, and their combination on RT cell cycle regulation and apoptosis were assessed by: i) cell survival assays, ii) FACS analysis, iii) caspase activity assays, and iv) immunoblot analysis. Furthermore, the role of p53 in flavopiridol- and 4OH-Tam-mediated induction of cell cycle arrest and apoptosis was characterized using RNA interference (siRNA) analysis. The effect of p53 on flavopiridol-mediated induction of caspases 2, 3, 8 and 9 was also determined. We found that the combination of flavopiridol and 4OH-Tam potently inhibited the growth of RT cells. Low nanomolar concentrations of flavopiridol induced G{sub 2} arrest, which was correlated to down-modulation of cyclin B1 and up-regulation of p53. Addition of 4OH-Tam did not affect flavopiridol-mediated G{sub 2} arrest, but enhanced caspase 3,7-mediated apoptosis induced by the drug. Abrogation of p53 by siRNA abolished flavopiridol-induced G{sub 2} arrest, but enhanced flavopiridol- (but not 4OH-Tam-) mediated apoptosis, by enhancing caspase 2 and 3 activities. Combining flavopiridol with 4OH-Tam potently inhibited the growth of RT cells by increasing the ability of either drug alone to induce caspases 2 and 3 thereby causing apoptosis. The potency of flavopiridol was enhanced by abrogation of p53. Our results

Potent inhibition of rhabdoid tumor cells by combination of flavopiridol and 4OH-tamoxifen

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Mani Sridhar

2010-11-01

Full Text Available Abstract Background Rhabdoid Tumors (RTs are highly aggressive pediatric malignancies with poor prognosis. There are currently no standard or effective treatments for RTs in part because treatments are not designed to specifically target these tumors. Our previous studies indicated that targeting the cyclin/cdk pathway is a novel therapeutic strategy for RTs and that a pan-cdk inhibitor, flavopiridol, inhibits RT growth. Since the toxicities and narrow window of activity associated with flavopiridol may limit its clinical use, we tested the effect of combining flavopiridol with 4-hydroxy-Tamoxifen (4OH-Tam in order to reduce the concentration of flavopiridol needed for inhibition of RTs. Methods The effects of flavopiridol, 4OH-Tam, and their combination on RT cell cycle regulation and apoptosis were assessed by: i cell survival assays, ii FACS analysis, iii caspase activity assays, and iv immunoblot analysis. Furthermore, the role of p53 in flavopiridol- and 4OH-Tam-mediated induction of cell cycle arrest and apoptosis was characterized using RNA interference (siRNA analysis. The effect of p53 on flavopiridol-mediated induction of caspases 2, 3, 8 and 9 was also determined. Results We found that the combination of flavopiridol and 4OH-Tam potently inhibited the growth of RT cells. Low nanomolar concentrations of flavopiridol induced G2 arrest, which was correlated to down-modulation of cyclin B1 and up-regulation of p53. Addition of 4OH-Tam did not affect flavopiridol-mediated G2 arrest, but enhanced caspase 3,7-mediated apoptosis induced by the drug. Abrogation of p53 by siRNA abolished flavopiridol-induced G2 arrest, but enhanced flavopiridol- (but not 4OH-Tam- mediated apoptosis, by enhancing caspase 2 and 3 activities. Conclusions Combining flavopiridol with 4OH-Tam potently inhibited the growth of RT cells by increasing the ability of either drug alone to induce caspases 2 and 3 thereby causing apoptosis. The potency of flavopiridol was

Intracellular targeting of annexin A2 inhibits tumor cell adhesion, migration, and in vivo grafting.

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Staquicini, Daniela I; Rangel, Roberto; Guzman-Rojas, Liliana; Staquicini, Fernanda I; Dobroff, Andrey S; Tarleton, Christy A; Ozbun, Michelle A; Kolonin, Mikhail G; Gelovani, Juri G; Marchiò, Serena; Sidman, Richard L; Hajjar, Katherine A; Arap, Wadih; Pasqualini, Renata

2017-06-26

Cytoskeletal-associated proteins play an active role in coordinating the adhesion and migration machinery in cancer progression. To identify functional protein networks and potential inhibitors, we screened an internalizing phage (iPhage) display library in tumor cells, and selected LGRFYAASG as a cytosol-targeting peptide. By affinity purification and mass spectrometry, intracellular annexin A2 was identified as the corresponding binding protein. Consistently, annexin A2 and a cell-internalizing, penetratin-fused version of the selected peptide (LGRFYAASG-pen) co-localized and specifically accumulated in the cytoplasm at the cell edges and cell-cell contacts. Functionally, tumor cells incubated with LGRFYAASG-pen showed disruption of filamentous actin, focal adhesions and caveolae-mediated membrane trafficking, resulting in impaired cell adhesion and migration in vitro. These effects were paralleled by a decrease in the phosphorylation of both focal adhesion kinase (Fak) and protein kinase B (Akt). Likewise, tumor cells pretreated with LGRFYAASG-pen exhibited an impaired capacity to colonize the lungs in vivo in several mouse models. Together, our findings demonstrate an unrecognized functional link between intracellular annexin A2 and tumor cell adhesion, migration and in vivo grafting. Moreover, this work uncovers a new peptide motif that binds to and inhibits intracellular annexin A2 as a candidate therapeutic lead for potential translation into clinical applications.

T Lymphocyte Inhibition by Tumor-Infiltrating Dendritic Cells Involves Ectonucleotidase CD39 but Not Arginase-1

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Malika Trad

2015-01-01

Full Text Available T lymphocytes activated by dendritic cells (DC which present tumor antigens play a key role in the antitumor immune response. However, in patients suffering from active cancer, DC are not efficient at initiating and supporting immune responses as they participate to T lymphocyte inhibition. DC in the tumor environment are functionally defective and exhibit a characteristic of immature phenotype, different to that of DC present in nonpathological conditions. The mechanistic bases underlying DC dysfunction in cancer responsible for the modulation of T-cell responses and tumor immune escape are still being investigated. Using two different mouse tumor models, we showed that tumor-infiltrating DC (TIDC are constitutively immunosuppressive, exhibit a semimature phenotype, and impair responder T lymphocyte proliferation and activation by a mechanism involving CD39 ectoenzyme.

Kaempferol suppresses bladder cancer tumor growth by inhibiting cell proliferation and inducing apoptosis.

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Dang, Qiang; Song, Wenbin; Xu, Defeng; Ma, Yanmin; Li, Feng; Zeng, Jin; Zhu, Guodong; Wang, Xinyang; Chang, Luke S; He, Dalin; Li, Lei

2015-09-01

The effects of the flavonoid compound, kaempferol, which is an inhibitor of cancer cell proliferation and an inducer of cell apoptosis have been shown in various cancers, including lung, pancreatic, and ovarian, but its effect has never been studied in bladder cancer. Here, we investigated the effects of kaempferol on bladder cancer using multiple in vitro cell lines and in vivo mice studies. The MTT assay results on various bladder cancer cell lines showed that kaempferol enhanced bladder cancer cell cytotoxicity. In contrast, when analyzed by the flow cytometric analysis, DNA ladder experiment, and TUNEL assay, kaempferol significantly was shown to induce apoptosis and cell cycle arrest. These in vitro results were confirmed in in vivo mice studies using subcutaneous xenografted mouse models. Consistent with the in vitro results, we found that treating mice with kaempferol significant suppression in tumor growth compared to the control group mice. Tumor tissue staining results showed decreased expressions of the growth related markers, yet increased expressions in apoptosis markers in the kaempferol treated group mice tissues compared to the control group mice. In addition, our in vitro and in vivo data showed kaempferol can also inhibit bladder cancer invasion and metastasis. Further mechanism dissection studies showed that significant down-regulation of the c-Met/p38 signaling pathway is responsible for the kaempferol mediated cell proliferation inhibition. All these findings suggest kaempferol might be an effective and novel chemotherapeutic drug to apply for the future therapeutic agent to combat bladder cancer. © 2014 Wiley Periodicals, Inc.

Potent inhibition of tumoral hypoxia-inducible factor 1α by albendazole

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Pourgholami, Mohammad H; Cai, Zhao Y; Badar, Samina; Wangoo, Kiran; Poruchynsky, Marianne S; Morris, David L

2010-01-01

Emerging reports suggest resistance, increased tumor invasiveness and metastasis arising from treatment with drugs targeting vascular endothelial growth factor (VEGF). It is believed that increased tumoral hypoxia plays a prominent role in the development of these phenomena. Inhibition of tumoral hypoxia inducible factor (HIF-1α) is thus becoming an increasingly attractive therapeutic target in the treatment of cancer. We hypothesized that the anti-VEGF effect of albendazole (ABZ) could be mediated through inhibition of tumoral HIF-1α. In vitro, the effects of ABZ on HIF-1α levels in human ovarian cancer cells (OVCAR-3) were investigated using hypoxic chamber or desferrioxamine (DFO) induced-hypoxia. In vivo, the effects of ABZ (150 mg/kg, i.p., single dose) on the tumor levels of HIF-1α and VEGF protein and mRNA were investigated by western blotting, RT-PCR and real time-PCR. In vitro, ABZ inhibited cellular HIF-1α protein accumulation resulting from placement of cells under hypoxic chamber or exposure to DFO. In vivo, tumors excised from vehicle treated mice showed high levels of both HIF-1α and VEGF. Whereas, tumoral HIF-1α and VEGF protein levels were highly suppressed in ABZ treated mice. Tumoral VEGFmRNA (but not HIF-1αmRNA) was also found to be highly suppressed by ABZ. These results demonstrate for the first time the effects of an acute dose of ABZ in profoundly suppressing both HIF-1α and VEGF within the tumor. This dual inhibition may provide additional value in inhibiting angiogenesis and be at least partially effective in inhibiting tumoral HIF-1α surge, tumor invasiveness and metastasis

Bovine Lactoferrin and Lactoferricin, a Peptide Derived from Bovine Lactoferrin, Inhibit Tumor Metastasis in Mice

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Watanabe, Shikiko; Watanabe, Ryosuke; Hata, Katsusuke; Shimazaki, Kei–ichi; Azuma, Ichiro

1997-01-01

We investigated the effect of a bovine milk protein, lactoferrin (LF–B), and a pepsin–generated peptide of LF–B, lactoferricin (Lfcin–B), on inhibition of tumor metastasis produced by highly metastatic murine tumor cells, B16–BL6 melanoma and L5178Y–ML25 lymphoma cells, using experimental and spontaneous metastasis models in syngeneic mice. The subcutaneous (s.c.) administration of bovine apo–lactoferrin (apo–LF–B, 1 mg/mouse) and Lfcin–B (0.5 mg/monse) 1 day after tumor inoculation significantly inhibited liver and lung metastasis of L5178Y–ML25 cells. However, human apo–lactoferrin (apo–LF–H) and bovine holo–lactoferrin (holo–LF–B) at the dose of 1 mg/mouse failed to inhibit tumor metastasis of L5178Y–ML25 cells. Similarly, the s.c. administration of apo–LF–B as well as Lfcin–B, but not apo–LF–H and holo–LF–B, 1 day after tumor inoculation resulted in significant inhibition of lung metastasis of B16–BL6 cells in an experimental metastasis model. Furthermore, in in vivo analysis for tumor–induced angiogenesis, both apo–LF–B and Lfcin–B inhibited the number of tumor–induced blood vessels and suppressed tumor growth on day 8 after tumor inoculation. However, in a long–term analysis of tumor growth for up to 21 days after tumor inoculation, single administration of apo–LF–B significantly suppressed the growth of B16–BL6 cells throughout the examination period, whereas Lfcin–B showed inhibitory activity only during the early period (8 days). In spontaneous metastasis of B16–BL6 melanoma cells, multiple administration of both apo–LF–B and Lfcin–B into tumor–bearing mice significantly inhibited lung metastasis produced by B16–BL6 cells, though only apo–LF–B exhibited an inhibitory effect on tumor growth at the time of primary tumor amputation (on day 21) after tumor inoculation. These results suggest that apo–LF–B and Lfcin–B inhibit tumor metastasis through different

Arctigenin inhibits prostate tumor cell growth in vitro and in vivo.

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Wang, Piwen; Solorzano, Walter; Diaz, Tanya; Magyar, Clara E; Henning, Susanne M; Vadgama, Jaydutt V

2017-06-01

The low bioavailability of most phytochemicals limits their translation to humans. We investigated whether arctigenin, a novel anti-inflammatory lignan from the seeds of Arctium lappa , has favorable bioavailability/potency against prostate cancer. The anticarcinogenic activity of arctigenin was investigated both in vitro using the androgen-sensitive LNCaP and LAPC-4 human prostate cancer cells and pre-malignant WPE1-NA22 cells, and in vivo using xenograft mouse models. Arctigenin at lower doses (arctigenin at 50mg/kg (LD) or 100mg/kg (HD) b.w. daily or vehicle control by oral gavage. After 6 weeks, tumor growth was inhibited by 50% (LD) and 70% (HD) compared to control. A stronger tumor inhibitory effect was observed in a second experiment where arctigenin intervention started two weeks prior to tumor implantation. Arc was detectable in blood and tumors in Arc groups, with a mean value up to 2.0 μM in blood, and 8.3 nmol/g tissue in tumors. Tumor levels of proliferation marker Ki67, total and nuclear androgen receptor, and growth factors including VEGF, EGF, and FGF-β were significantly decreased by Arc, along with an increase in apoptosis marker of Bax/Bcl-2 ratio. Genes responsive to arctigenin were identified including TIMP3 and ZNF185, and microRNAs including miR-126-5p, and miR-21-5p. This study provides the first in vivo evidence of the strong anticancer activity of arctigenin in prostate cancer. The effective dose of arctigenin in vitro is physiologically achievable in vivo , which provides a high promise in its translation to human application.

3-Bromopyruvate inhibits human gastric cancer tumor growth in nude mice via the inhibition of glycolysis.

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Xian, Shu-Lin; Cao, Wei; Zhang, Xiao-Dong; Lu, Yun-Fei

2015-02-01

Tumor cells primarily depend upon glycolysis in order to gain energy. Therefore, the inhibition of glycolysis may inhibit tumor growth. Our previous study demonstrated that 3-bromopyruvate (3-BrPA) inhibited gastric cancer cell proliferation in vitro . However, the ability of 3-BrPA to suppress tumor growth in vivo, and its underlying mechanism, have yet to be elucidated. The aim of the present study was to investigate the inhibitory effect of 3-BrPA in an animal model of gastric cancer. It was identified that 3-BrPA exhibited strong inhibitory effects upon xenograft tumor growth in nude mice. In addition, the antitumor function of 3-BrPA exhibited a dose-effect association, which was similar to that of the chemotherapeutic agent, 5-fluorouracil. Furthermore, 3-BrPA exhibited low toxicity in the blood, liver and kidneys of the nude mice. The present study hypothesized that the inhibitory effect of 3-BrPA is achieved through the inhibition of hexokinase activity, which leads to the downregulation of B-cell lymphoma 2 (Bcl-2) expression, the upregulation of Bcl-2-associated X protein expression and the subsequent activation of caspase-3. These data suggest that 3-BrPA may be a novel therapy for the treatment of gastric cancer.

Inhibition of endothelial cell proliferation by targeting Rac1 GTPase with small interference RNA in tumor cells

International Nuclear Information System (INIS)

Xue Yan; Bi Feng; Zhang Xueyong; Pan Yanglin; Liu Na; Zheng Yi; Fan Daiming

2004-01-01

Hypoxia-induced angiogenesis plays an important role in the malignancy of solid tumors. A number of recent studies including our own have suggested that Rho family small GTPases are involved in this process, and Rac1, a prominent member of the Rho family, may be critical in regulating hypoxia-induced gene activation of several angiogenesis factors and tumor suppressors. To further define Rac1 function in angiogenesis and to explore novel approaches to modulate angiogenesis, we employed the small interference RNA technique to knock down gene expression of Rac1 in gastric cancer cell line AGS that expresses a high level of Rac1. Both the mRNA and protein levels of Rac1 in the AGS cells were decreased dramatically after transfection with a Rac1-specific siRNA vector. When the conditioned medium derived from the Rac1 downregulated AGS cells was applied to the human endothelial cells, it could significantly inhibit the cell proliferation. Further study proved that, VEGF and HIF-1α, two angiogenesis promoting factors, were found to be downregulated whereas p53 and VHL, which are tumor suppressors and angiogenesis inhibitors, were upregulated in the Rac1 siRNA transfected cells. Our results suggest that Rac1 may be involved in angiogenesis by controlling the expression of angiogenesis-related factors and provide a possible strategy for the treatment of tumor angiogenesis by targeting the Rac1 GTPase

Extract of Cordyceps militaris inhibits angiogenesis and suppresses tumor growth of human malignant melanoma cells.

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Ruma, I Made Winarsa; Putranto, Endy Widya; Kondo, Eisaku; Watanabe, Risayo; Saito, Ken; Inoue, Yusuke; Yamamoto, Ken-Ichi; Nakata, Susumu; Kaihata, Masaji; Murata, Hitoshi; Sakaguchi, Masakiyo

2014-07-01

Angiogenesis is essential for tumor development and metastasis. Among several angiogenic factors, vascular endothelial growth factor receptor (VEGF) is important for tumor-derived angiogenesis and commonly overexpressed in solid tumors. Thus, many antitumor strategies targeting VEGF have been developed to inhibit cancer angiogenesis, offering insights into the successful treatment of solid cancers. However, there are a number of issues such as harmful effects on normal vascularity in clinical trials. Taking this into consideration, we employed Cordyceps militaris as an antitumor approach due to its biological safety in vivo. The herbal medicinal mushroom Cordyceps militaris has been reported to show potential anticancer properties including anti-angiogenic capacity; however, its concrete properties have yet to be fully demonstrated. In this study, we aimed to elucidate the biological role of Cordyceps militaris extract in tumor cells, especially in regulating angiogenesis and tumor growth of a human malignant melanoma cell line. We demonstrated that Cordyceps militaris extract remarkably suppressed tumor growth via induction of apoptotic cell death in culture that links to the abrogation of VEGF production in melanoma cells. This was followed by mitigation of Akt1 and GSK-3β activation, while p38α phosphorylation levels were increased. Extract treatment in mouse model xenografted with human melanoma cells resulted in a dramatic antitumor effect with down-regulation of VEGF expression. The results suggest that suppression of tumor growth by Cordyceps militaris extract is, at least, mediated by its anti-angiogenicity and apoptosis induction capacities. Cordyceps militaris extract may be a potent antitumor herbal drug for solid tumors.

Celecoxib Induced Tumor Cell Radiosensitization by Inhibiting Radiation Induced Nuclear EGFR Transport and DNA-Repair: A COX-2 Independent Mechanism

International Nuclear Information System (INIS)

Dittmann, Klaus H.; Mayer, Claus; Ohneseit, Petra A.; Raju, Uma; Andratschke, Nickolaus H.; Milas, Luka; Rodemann, H. Peter

2008-01-01

Purpose: The purpose of the study was to elucidate the molecular mechanisms mediating radiosensitization of human tumor cells by the selective cyclooxygenase (COX)-2 inhibitor celecoxib. Methods and Materials: Experiments were performed using bronchial carcinoma cells A549, transformed fibroblasts HH4dd, the FaDu head-and-neck tumor cells, the colon carcinoma cells HCT116, and normal fibroblasts HSF7. Effects of celecoxib treatment were assessed by clonogenic cell survival, Western analysis, and quantification of residual DNA damage by γH 2 AX foci assay. Results: Celecoxib treatment resulted in a pronounced radiosensitization of A549, HCT116, and HSF7 cells, whereas FaDu and HH4dd cells were not radiosensitized. The observed radiosensitization could neither be correlated with basal COX-2 expression pattern nor with basal production of prostaglandin E2, but was depended on the ability of celecoxib to inhibit basal and radiation-induced nuclear transport of epidermal growth factor receptor (EGFR). The nuclear EGFR transport was strongly inhibited in A549-, HSF7-, and COX-2-deficient HCT116 cells, which were radiosensitized, but not in FaDu and HH4dd cells, which resisted celecoxib-induced radiosensitization. Celecoxib inhibited radiation-induced DNA-PK activation in A549, HSF7, and HCT116 cells, but not in FaDu and HH4dd cells. Consequentially, celecoxib increased residual γH2AX foci after irradiation, demonstrating that inhibition of DNA repair has occurred in responsive A549, HCT116, and HSF7 cells only. Conclusions: Celecoxib enhanced radiosensitivity by inhibition of EGFR-mediated mechanisms of radioresistance, a signaling that was independent of COX-2 activity. This novel observation may have therapeutic implications such that COX-2 inhibitors may improve therapeutic efficacy of radiation even in patients whose tumor radioresistance is not dependent on COX-2

Human breast tumor cells are more resistant to cardiac glycoside toxicity than non-tumorigenic breast cells.

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Rebecca J Clifford

Full Text Available Cardiotonic steroids (CTS, specific inhibitors of Na,K-ATPase activity, have been widely used for treating cardiac insufficiency. Recent studies suggest that low levels of endogenous CTS do not inhibit Na,K-ATPase activity but play a role in regulating blood pressure, inducing cellular kinase activity, and promoting cell viability. Higher CTS concentrations inhibit Na,K-ATPase activity and can induce reactive oxygen species, growth arrest, and cell death. CTS are being considered as potential novel therapies in cancer treatment, as they have been shown to limit tumor cell growth. However, there is a lack of information on the relative toxicity of tumor cells and comparable non-tumor cells. We have investigated the effects of CTS compounds, ouabain, digitoxin, and bufalin, on cell growth and survival in cell lines exhibiting the full spectrum of non-cancerous to malignant phenotypes. We show that CTS inhibit membrane Na,K-ATPase activity equally well in all cell lines tested regardless of metastatic potential. In contrast, the cellular responses to the drugs are different in non-tumor and tumor cells. Ouabain causes greater inhibition of proliferation and more extensive apoptosis in non-tumor breast cells compared to malignant or oncogene-transfected cells. In tumor cells, the effects of ouabain are accompanied by activation of anti-apoptotic ERK1/2. However, ERK1/2 or Src inhibition does not sensitize tumor cells to CTS cytotoxicity, suggesting that other mechanisms provide protection to the tumor cells. Reduced CTS-sensitivity in breast tumor cells compared to non-tumor cells indicates that CTS are not good candidates as cancer therapies.

HoxD10 gene delivery using adenovirus/adeno-associate hybrid virus inhibits the proliferation and tumorigenicity of GH4 pituitary lactotrope tumor cells

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Cho, Mi Ae; Yashar, Parham; Kim, Suk Kyoung; Noh, Taewoong; Gillam, Mary P.; Lee, Eun Jig; Jameson, J. Larry

2008-01-01

Prolactinoma is one of the most common types of pituitary adenoma. It has been reported that a variety of growth factors and cytokines regulating cell growth and angiogenesis play an important role in the growth of prolactinoma. HoxD10 has been shown to impair endothelial cell migration, block angiogenesis, and maintain a differentiated phenotype of cells. We investigated whether HoxD10 gene delivery could inhibit the growth of prolactinoma. Rat GH4 lactotrope tumor cells were infected with adenovirus/adeno-associated virus (Ad/AAV) hybrid vectors carrying the mouse HoxD10 gene (Hyb-HoxD10) or the β-galactosidase gene (Hyb-Gal). Hyb-HoxD10 expression inhibited GH4 cell proliferation in vitro. The expression of FGF-2 and cyclin D2 was inhibited in GH4 cells infected with Hyb-HoxD10. GH4 cells transduced with Hyb-HoxD10 did not form tumors in nude mice. These results indicate that the delivery of HoxD10 could potentially inhibit the growth of PRL-secreting tumors. This approach may be a useful tool for targeted therapy of prolactinoma and other neoplasms

Quilamine HQ1-44, an iron chelator vectorized toward tumor cells by the polyamine transport system, inhibits HCT116 tumor growth without adverse effect.

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Renaud, Stéphanie; Corcé, Vincent; Cannie, Isabelle; Ropert, Martine; Lepage, Sylvie; Loréal, Olivier; Deniaud, David; Gaboriau, François

2015-08-01

Tumor cell growth requires large iron quantities and the deprivation of this metal induced by synthetic metal chelators is therefore an attractive method for limiting the cancer cell proliferation. The antiproliferative effect of the Quilamine HQ1-44, a new iron chelator vectorized toward tumor cells by a polyamine chain, is related to its high selectivity for the Polyamine Transport System (PTS), allowing its preferential uptake by tumoral cells. The difference in PTS activation between healthy cells and tumor cells enables tumor cells to be targeted, whereas the strong dependence of these cells on iron ensures a secondary targeting. Here, we demonstrated in vitro that HQ1-44 inhibits DNA synthesis and cell proliferation of HCT116 cells by modulating the intracellular metabolism of both iron and polyamines. Moreover, in vivo, in xenografted athymic nude mice, we found that HQ1-44 was as effective as cis-platin in reducing HCT116 tumor growth, without its side effects. Furthermore, as suggested by in vitro data, the depletion in exogenous or endogenous polyamines, known to activate the PTS, dramatically enhanced the antitumor efficiency of HQ1-44. These data support the need for further studies to assess the value of HQ1-44 as an adjuvant treatment in cancer. Copyright © 2015 Elsevier Inc. All rights reserved.

Immunization with mutant HPV16 E7 protein inhibits the growth of TC-1 cells in tumor-bearing mice.

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Li, Yan-Li; Ma, Zhong-Liang; Zhao, Yue; Zhang, Jing

2015-04-01

Two human papillomavirus (HPV) 16 oncogenic proteins, E6 and E7, are co-expressed in the majority of HPV16-induced cervical cancer cells. Thus, the E6 and E7 proteins are good targets for developing therapeutic vaccines for cervical cancer. In the present study, immunization with the mutant non-transforming HPV16 E7 (mE7) protein was demonstrated to inhibit the growth of TC-1 cells in the TC-1 mouse model. The HPV16 mE7 gene was amplified by splicing overlap extension polymerase chain reaction using pET-28a(+)-E7 as a template, and the gene was cloned into pET-28a(+) to form pET-28a(+)-mE7. Compared with the E7 protein, mE7 lacks amino acid residues 94-98, and at residue 24, there is a Cys to Gly substitution. pET-28a(+)-mE7 was then introduced into Escherichia coli Rosetta. The expression of mE7 was induced by isopropyl β-D-1-thiogalactopyranoside. The mE7 protein was purified using Ni-NTA agarose and detected by SDS-PAGE and western blot analysis. In the tumor prevention model, no tumor was detected in the mice vaccinated with the mE7 protein. After 40 days, the tumor-free mice and control mice were challenged with 2×10 5 TC-1 cells. All control mice developed tumors six days later, but mE7 immunized mice were tumor free until 90 days. In the tumor therapy model, the TC-1 cells were initially injected subcutaneously, and the mice were subsequently vaccinated. Vaccination against the mE7 protein may significantly inhibit TC-1 cell growth compared to the control. These results demonstrated that immunization with the HPV16 mE7 protein elicited a long-term protective immunity against TC-1 tumor growth and generated a significant inhibition of TC-1 growth in a TC-1 mouse model.

Enalapril and ASS inhibit tumor growth in a transgenic mouse model of islet cell tumors.

Science.gov (United States)

Fendrich, V; Lopez, C L; Manoharan, J; Maschuw, K; Wichmann, S; Baier, A; Holler, J P; Ramaswamy, A; Bartsch, D K; Waldmann, J

2014-10-01

Accumulating evidence suggests a role for angiotensin-converting enzymes involving the angiotensin II-receptor 1 (AT1-R) and the cyclooxygenase pathway in carcinogenesis. The effects of ASS and enalapril were assessed in vitro and in a transgenic mouse model of pancreatic neuroendocrine neoplasms (pNENs). The effects of enalapril and ASS on proliferation and expression of the AGTR1A and its target gene vascular endothelial growth factor (Vegfa) were assessed in the neuroendocrine cell line BON1. Rip1-Tag2 mice were treated daily with either 0.6 mg/kg bodyweight of enalapril i.p., 20 mg/kg bodyweight of ASS i.p., or a vehicle in a prevention (weeks 5-12) and a survival group (week 5 till death). Tumor surface, weight of pancreatic glands, immunostaining for AT1-R and nuclear factor kappa beta (NFKB), and mice survival were analyzed. In addition, sections from human specimens of 20 insulinomas, ten gastrinomas, and 12 non-functional pNENs were evaluated for AT1-R and NFKB (NFKB1) expression and grouped according to the current WHO classification. Proliferation was significantly inhibited by enalapril and ASS in BON1 cells, with the combination being the most effective. Treatment with enalapril and ASS led to significant downregulation of known target genes Vegf and Rela at RNA level. Tumor growth was significantly inhibited by enalapril and ASS in the prevention group displayed by a reduction of tumor size (84%/67%) and number (30%/45%). Furthermore, daily treatment with enalapril and ASS prolonged the overall median survival compared with vehicle-treated Rip1-Tag2 (107 days) mice by 9 and 17 days (P=0.016 and P=0.013). The AT1-R and the inflammatory transcription factor NFKB were abolished completely upon enalapril and ASS treatment. AT1-R and NFKB expressions were observed in 80% of human pNENs. Enalapril and ASS may provide an approach for chemoprevention and treatment of pNENs. © 2014 Society for Endocrinology.

Capsaicin Inhibits Multiple Bladder Cancer Cell Phenotypes by Inhibiting Tumor-Associated NADH Oxidase (tNOX and Sirtuin1 (SIRT1

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Ming-Hung Lin

2016-06-01

Full Text Available Bladder cancer is one of the most frequent cancers among males, and its poor survival rate reflects problems with aggressiveness and chemo-resistance. Recent interest has focused on the use of chemopreventatives (nontoxic natural agents that may suppress cancer progression to induce targeted apoptosis for cancer therapy. Capsaicin, which has anti-cancer properties, is one such agent. It is known to preferentially inhibit a tumor-associated NADH oxidase (tNOX that is preferentially expressed in cancer/transformed cells. Here, we set out to elucidate the correlation between tNOX expression and the inhibitory effects of capsaicin in human bladder cancer cells. We showed that capsaicin downregulates tNOX expression and decreases bladder cancer cell growth by enhancing apoptosis. Moreover, capsaicin was found to reduce the expression levels of several proteins involved in cell cycle progression, in association with increases in the cell doubling time and enhanced cell cycle arrest. Capsaicin was also shown to inhibit the activation of ERK, thereby reducing the phosphorylation of paxillin and FAK, which leads to decreased cell migration. Finally, our results indicate that RNA interference-mediated tNOX depletion enhances spontaneous apoptosis, prolongs cell cycle progression, and reduces cell migration and the epithelial-mesenchymal transition. We also observed a downregulation of sirtuin 1 (SIRT1 in these tNOX-knockdown cells, a deacetylase that is important in multiple cellular functions. Taken together, our results indicate that capsaicin inhibits the growth of bladder cancer cells by inhibiting tNOX and SIRT1 and thereby reducing proliferation, attenuating migration, and prolonging cell cycle progression.

Protein-bound polysaccharide from Phellinus linteus inhibits tumor growth, invasion, and angiogenesis and alters Wnt/β-catenin in SW480 human colon cancer cells

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Park Hae-Duck

2011-07-01

Full Text Available Abstract Background Polysaccharides extracted from the Phellinus linteus (PL mushroom are known to possess anti-tumor effects. However, the molecular mechanisms responsible for the anti-tumor properties of PL remain to be explored. Experiments were carried out to unravel the anticancer effects of PL. Methods The anti-cancer effects of PL were examined in SW480 colon cancer cells by evaluating cell proliferation, invasion and matrix metallo-proteinase (MMP activity. The anti-angiogenic effects of PL were examined by assessing human umbilical vein endothelial cell (HUVEC proliferation and capillary tube formation. The in vivo effect of PL was evaluated in an athymic nude mouse SW480 tumor engraft model. Results PL (125-1000 μg/mL significantly inhibited cell proliferation and decreased β-catenin expression in SW480 cells. Expression of cyclin D1, one of the downstream-regulated genes of β-catenin, and T-cell factor/lymphocyte enhancer binding factor (TCF/LEF transcription activity were also significantly reduced by PL treatment. PL inhibited in vitro invasion and motility as well as the activity of MMP-9. In addition, PL treatment inhibited HUVEC proliferation and capillary tube formation. Tumor growth of SW480 cells implanted into nude mice was significantly decreased as a consequence of PL treatment, and tumor tissues from treated animals showed an increase in the apoptotic index and a decrease in β-catenin expression. Moreover, the proliferation index and microvessel density were significantly decreased. Conclusions These data suggest that PL suppresses tumor growth, invasion, and angiogenesis through the inhibition of Wnt/β-catenin signaling in certain colon cancer cells.

Luteolin inhibits the Nrf2 signaling pathway and tumor growth in vivo

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Chian, Song; Thapa, Ruby; Chi, Zhexu [Department of Biochemistry and Genetics, School of Medicine, Zhejiang University, Hangzhou 310058 (China); Wang, Xiu Jun [Department of Pharmacology, School of Medicine, Zhejiang University, Hangzhou 310058 (China); Tang, Xiuwen, E-mail: xiuwentang@zju.edu.cn [Department of Biochemistry and Genetics, School of Medicine, Zhejiang University, Hangzhou 310058 (China)

2014-05-16

Highlights: • Luteolin inhibits the Nrf2 pathway in mouse liver and in xenografted tumors. • Luteolin markedly inhibits the growth of xenograft tumors. • Luteolin enhances the anti-cancer effect of cisplatin in mice in vivo. • Luteolin could serve as an adjuvant in the chemotherapy of NSCLC. - Abstract: Nuclear factor erythroid 2-related factor 2 (Nrf2) is over-expressed in many types of tumor, promotes tumor growth, and confers resistance to anticancer therapy. Hence, Nrf2 is regarded as a novel therapeutic target in cancer. Previously, we reported that luteolin is a strong inhibitor of Nrf2 in vitro. Here, we showed that luteolin reduced the constitutive expression of NAD(P)H quinone oxidoreductase 1 in mouse liver in a time- and dose-dependent manner. Further, luteolin inhibited the expression of antioxidant enzymes and glutathione transferases, decreasing the reduced glutathione in the liver of wild-type mice under both constitutive and butylated hydroxyanisole-induced conditions. In contrast, such distinct responses were not detected in Nrf2{sup −/−} mice. In addition, oral administration of luteolin, either alone or combined with intraperitoneal injection of the cytotoxic drug cisplatin, greatly inhibited the growth of xenograft tumors from non-small-cell lung cancer (NSCLC) cell line A549 cells grown subcutaneously in athymic nude mice. Cell proliferation, the expression of Nrf2, and antioxidant enzymes were all reduced in tumor xenograft tissues. Furthermore, luteolin enhanced the anti-cancer effect of cisplatin. Together, our findings demonstrated that luteolin inhibits the Nrf2 pathway in vivo and can serve as an adjuvant in the chemotherapy of NSCLC.

NF-κB-Activating Complex Engaged in Response to EGFR Oncogene Inhibition Drives Tumor Cell Survival and Residual Disease in Lung Cancer

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Collin M. Blakely

2015-04-01

Full Text Available Although oncogene-targeted therapy often elicits profound initial tumor responses in patients, responses are generally incomplete because some tumor cells survive initial therapy as residual disease that enables eventual acquired resistance. The mechanisms underlying tumor cell adaptation and survival during initial therapy are incompletely understood. Here, through the study of EGFR mutant lung adenocarcinoma, we show that NF-κB signaling is rapidly engaged upon initial EGFR inhibitor treatment to promote tumor cell survival and residual disease. EGFR oncogene inhibition induced an EGFR-TRAF2-RIP1-IKK complex that stimulated an NF-κB-mediated transcriptional survival program. The direct NF-κB inhibitor PBS-1086 suppressed this adaptive survival program and increased the magnitude and duration of initial EGFR inhibitor response in multiple NSCLC models, including a patient-derived xenograft. These findings unveil NF-κB activation as a critical adaptive survival mechanism engaged by EGFR oncogene inhibition and provide rationale for EGFR and NF-κB co-inhibition to eliminate residual disease and enhance patient responses.

Salinomycin inhibits proliferation and induces apoptosis of human nasopharyngeal carcinoma cell in vitro and suppresses tumor growth in vivo

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Wu, Danxin; Zhang, Yu; Huang, Jie; Fan, Zirong; Shi, Fengrong; Wang, Senming, E-mail: wsenming@126.com

2014-01-10

Highlight: •We first evaluated the effect of salinomycin on nasopharyngeal carcinoma (NPC). •Salinomycin could inhibit Wnt/β-catenin signaling and induce apoptosis in NPC. •So salinomycin may be a good potential candidate for the chemotherapy of NPC. -- Abstract: Salinomycin (Sal) is a polyether ionophore antibiotic that has recently been shown to induce cell death in various human cancer cells. However, whether salinomycin plays a functional role in nasopharyngeal carcinoma (NPC) has not been determined to date. The present study investigated the chemotherapeutic efficacy of salinomycin and its molecular mechanisms of action in NPC cells. Salinomycin efficiently inhibited proliferation and invasion of 3 NPC cell lines (CNE-1, CNE-2, and CNE-2/DDP) and activated a extensive apoptotic process that is accompanied by activation of caspase-3 and caspase-9, and decreased mitochondrial membrane potential. Meanwhile, the protein expression level of the Wnt coreceptor lipoprotein receptor related protein 6 (LRP6) and β-catenin was down-regulated, which showed that the Wnt/β-catenin signaling was involved in salinomycin-induced apoptosis of NPC cells. In a nude mouse NPC xenograft model, the anti-tumor effect of salinomycin was associated with the downregulation of β-catenin expression. The present study demonstrated that salinomycin can effectively inhibit proliferation and invasion, and induce apoptosis of NPC cells in vitro and inhibit tumor growth in vivo, probably via the inhibition of Wnt/β-catenin signaling, suggesting salinomycin as a potential candidate for the chemotherapy of NPC.

The tumor suppressor PTEN inhibits EGF-induced TSP-1 and TIMP-1 expression in FTC-133 thyroid carcinoma cells

International Nuclear Information System (INIS)

Soula-Rothhut, Mahdhia; Coissard, Cyrille; Sartelet, Herve; Boudot, Cedric; Bellon, Georges; Martiny, Laurent; Rothhut, Bernard

2005-01-01

Thrombospondin-1 (TSP-1) is a multidomain extracellular macromolecule that was first identified as natural modulator of angiogenesis and tumor growth. In the present study, we found that epidermal growth factor (EGF) up-regulated TSP-1 expression in FTC-133 (primary tumor) but not in FTC-238 (lung metastasis) thyroid cancer cells. Both EGF and TSP-1 induced expression of tissue inhibitor of metalloproteinase-1 (TIMP-1) in a mitogen-activated protein kinase/extracellular signal-regulated kinase (MAPK/ERK) and phosphatidylinositol 3-kinase (PI3-kinase)-dependent manner. In FTC-133 cells, EGF induced proliferation in a TSP-1- and TIMP-1-dependent manner. In addition, we determined that re-expression of the tumor suppressor protein PTEN induced cell death, an effect that correlated with a block of Akt kinase phosphorylation. EGF-induced TSP-1 and TIMP-1 promoter activity and protein expression were inhibited in FTC-133 cells stably expressing wtPTEN but not in cells expressing mutant PTEN. Furthermore, we found that wtPTEN inhibited EGF-but not TSP-1-stimulated FTC-133 cell migration and also inhibited invasion induced by EGF and by TSP-1. Finally, an antibody against TSP-1 reversed EGF-stimulated FTC-133 cell invasion as well as the constitutive invasive potential of FTC-238 cells. Overall, our results suggest that PTEN can function as an important modulator of extracellular matrix proteins in thyroid cancer. Therefore, analyzing differential regulation of TSP-1 by growth factors such as EGF can be helpful in understanding thyroid cancer development

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

Role of isothiocyanate conjugate of pterostilbene on the inhibition of MCF-7 cell proliferation and tumor growth in Ehrlich ascitic cell induced tumor bearing mice

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Nikhil, Kumar; Sharan, Shruti; Chakraborty, Ajanta [Molecular Endocrinology Laboratory, Department of Biotechnology, Indian Institute of Technology Roorkee, Roorkee 247 667, Uttarakhand (India); Bodipati, Naganjaneyulu; Krishna Peddinti, Rama [Department of Chemistry, Indian Institute of Technology Roorkee, Roorkee 247 667, Uttarakhand (India); Roy, Partha, E-mail: paroyfbs@iitr.ernet.in [Molecular Endocrinology Laboratory, Department of Biotechnology, Indian Institute of Technology Roorkee, Roorkee 247 667, Uttarakhand (India)

2014-01-15

Naturally occurring pterostilbene (PTER) and isothiocyanate (ITC) attract great attention due to their wide range of biological properties, including anti-cancer, anti-leukemic, anti-bacterial and anti-inflammatory activities. A novel class of hybrid compound synthesized by introducing an ITC moiety on PTER backbone was evaluated for its anti-cancer efficacy in hormone-dependent breast cancer cell line (MCF-7) in vitro and Ehrlich ascitic tumor bearing mice model in vivo. The novel hybrid molecule showed significant in vitro anti-cancer activity (IC{sub 50}=25±0.38) when compared to reference compound PTER (IC{sub 50}=65±0.42). The conjugate molecule induced both S and G2/M phase cell cycle arrest as indicated by flow cytometry analysis. In addition, the conjugate induced cell death was characterized by changes in cell morphology, DNA fragmentation, activation of caspase-9, release of cytochrome-c into cytosol and increased Bax: Bcl-2 ratio. The conjugate also suppressed the phosphorylation of Akt and ERK. The conjugate induced cell death was significantly increased in presence of A6730 (a potent Akt1/2 kinase inhibitor) and PD98059 (a specific ERK inhibitor). Moreover, the conjugated PTER inhibited tumor growth in Ehrlich ascitic cell induced tumor bearing mice as observed by reduction in tumor volume compared to untreated animals. Collectively, the pro-apoptotic effect of conjugate is mediated through the activation of caspases, and is correlated with the blockade of the Akt and ERK signaling pathways in MCF-7 cells. - Highlights: • Conjugate was prepared by appending isothiocyanate moiety on pterostilbene backbone. • Conjugate showed anticancer effects at comparatively lower dose than pterostilbene. • Conjugate caused blockage of the Akt and ERK signaling pathways in MCF-7 cells. • Conjugate significantly reduced solid tumor volume as compared to pterostilbene.

Role of isothiocyanate conjugate of pterostilbene on the inhibition of MCF-7 cell proliferation and tumor growth in Ehrlich ascitic cell induced tumor bearing mice

International Nuclear Information System (INIS)

Nikhil, Kumar; Sharan, Shruti; Chakraborty, Ajanta; Bodipati, Naganjaneyulu; Krishna Peddinti, Rama; Roy, Partha

2014-01-01

Naturally occurring pterostilbene (PTER) and isothiocyanate (ITC) attract great attention due to their wide range of biological properties, including anti-cancer, anti-leukemic, anti-bacterial and anti-inflammatory activities. A novel class of hybrid compound synthesized by introducing an ITC moiety on PTER backbone was evaluated for its anti-cancer efficacy in hormone-dependent breast cancer cell line (MCF-7) in vitro and Ehrlich ascitic tumor bearing mice model in vivo. The novel hybrid molecule showed significant in vitro anti-cancer activity (IC 50 =25±0.38) when compared to reference compound PTER (IC 50 =65±0.42). The conjugate molecule induced both S and G2/M phase cell cycle arrest as indicated by flow cytometry analysis. In addition, the conjugate induced cell death was characterized by changes in cell morphology, DNA fragmentation, activation of caspase-9, release of cytochrome-c into cytosol and increased Bax: Bcl-2 ratio. The conjugate also suppressed the phosphorylation of Akt and ERK. The conjugate induced cell death was significantly increased in presence of A6730 (a potent Akt1/2 kinase inhibitor) and PD98059 (a specific ERK inhibitor). Moreover, the conjugated PTER inhibited tumor growth in Ehrlich ascitic cell induced tumor bearing mice as observed by reduction in tumor volume compared to untreated animals. Collectively, the pro-apoptotic effect of conjugate is mediated through the activation of caspases, and is correlated with the blockade of the Akt and ERK signaling pathways in MCF-7 cells. - Highlights: • Conjugate was prepared by appending isothiocyanate moiety on pterostilbene backbone. • Conjugate showed anticancer effects at comparatively lower dose than pterostilbene. • Conjugate caused blockage of the Akt and ERK signaling pathways in MCF-7 cells. • Conjugate significantly reduced solid tumor volume as compared to pterostilbene

Galectin-1 Inhibitor OTX008 Induces Tumor Vessel Normalization and Tumor Growth Inhibition in Human Head and Neck Squamous Cell Carcinoma Models.

Science.gov (United States)

Koonce, Nathan A; Griffin, Robert J; Dings, Ruud P M

2017-12-09

Galectin-1 is a hypoxia-regulated protein and a prognostic marker in head and neck squamous cell carcinomas (HNSCC). Here we assessed the ability of non-peptidic galectin-1 inhibitor OTX008 to improve tumor oxygenation levels via tumor vessel normalization as well as tumor growth inhibition in two human HNSCC tumor models, the human laryngeal squamous carcinoma SQ20B and the human epithelial type 2 HEp-2. Tumor-bearing mice were treated with OTX008, Anginex, or Avastin and oxygen levels were determined by fiber-optics and molecular marker pimonidazole binding. Immuno-fluorescence was used to determine vessel normalization status. Continued OTX008 treatment caused a transient reoxygenation in SQ20B tumors peaking on day 14, while a steady increase in tumor oxygenation was observed over 21 days in the HEp-2 model. A >50% decrease in immunohistochemical staining for tumor hypoxia verified the oxygenation data measured using a partial pressure of oxygen (pO₂) probe. Additionally, OTX008 induced tumor vessel normalization as tumor pericyte coverage increased by approximately 40% without inducing any toxicity. Moreover, OTX008 inhibited tumor growth as effectively as Anginex and Avastin, except in the HEp-2 model where Avastin was found to suspend tumor growth. Galectin-1 inhibitor OTX008 transiently increased overall tumor oxygenation via vessel normalization to various degrees in both HNSCC models. These findings suggest that targeting galectin-1-e.g., by OTX008-may be an effective approach to treat cancer patients as stand-alone therapy or in combination with other standards of care.

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.

MicroRNA-202 inhibits tumor progression by targeting LAMA1 in esophageal squamous cell carcinoma

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Meng, Xiangrui, E-mail: xiangruimengzz@163.com [Department of Oncology, The First Affiliated Hospital of Zhengzhou University, 1 East Jianshe Road, Zhengzhou 450000, Henan Province (China); Chen, Xiaoqi [Department of Digestion and Oncology, The First Affiliated Hospital of Henan Uninversity of TCM, 19 Renmin Road, Zhengzhou 450000, Henan Province (China); Lu, Peng [Department of Gastrointestinal Surgery, The People' s Hospital of Zhengzhou, 33 Huanghe Road, Zhengzhou 450000, Henan Province (China); Ma, Wang; Yue, Dongli; Song, Lijie; Fan, Qingxia [Department of Oncology, The First Affiliated Hospital of Zhengzhou University, 1 East Jianshe Road, Zhengzhou 450000, Henan Province (China)

2016-05-13

Esophageal squamous cell carcinoma (ESCC) is one of the most aggressive malignancies in the gastrointestinal tract. Emerging studies have indicated that microRNAs (miRNAs) are strongly implicated in the development and progression of ESCC. Here, we focused on the function and the underlying molecular mechanism of miR-202 in ESCC. The results showed that miR-202 was significantly down-regulated in ESCC tissues and cell lines. Overexpression of miR-202 in ECa-109 and KYSE-510 cells markedly suppressed cell proliferation and cell migration, and induced cell apoptosis. Furthermore, laminin α1 (LAMA1) expression was frequently positive in ESCC tissues and inversely correlated with miR-202 expression. Then we demonstrated that miR-202 targeted 3'-untranslated region (UTR) of LAMA1 and inhibited its protein expression. Additionally, LAMA1 overexpression rescued the proliferation inhibition and cell apoptosis elevation induced by miR-202. MiR-202 also inhibited the protein expression of p-FAK and p-Akt, which were all reversed by LAMA1 overexpression. Taken together, these findings suggest that miR-202 may function as a novel tumor suppressor in ESCC by repressing cell proliferation and migration, and its biological effects may attribute the inhibition of LAMA1-mediated FAK-PI3K-Akt signaling. - Highlights: • Expression of miR-202 was decreased in ESCC tissues and cell lines. • MiR-202 overexpression inhibited ESCC cell growth and induced apoptosis. • MiR-202 directly targeted LAMA1 in ESCC. • The LAMA1-FAK-PI3K signaling mediated the suppressive role of miR-202.

3-bromopyruvate and sodium citrate target glycolysis, suppress survivin, and induce mitochondrial-mediated apoptosis in gastric cancer cells and inhibit gastric orthotopic transplantation tumor growth.

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Wang, Ting-An; Zhang, Xiao-Dong; Guo, Xing-Yu; Xian, Shu-Lin; Lu, Yun-Fei

2016-03-01

Glycolysis is the primary method utilized by cancer cells to produce the energy (adenosine triphosphate, ATP) required for cell proliferation. Therefore, inhibition of glycolysis may inhibit tumor growth. We previously found that both 3-bromopyruvate (3-BrPA) and sodium citrate (SCT) can inhibit glycolysis in vitro; however, the underlying inhibitory mechanisms remain unclear. In the present study, we used a human gastric cancer cell line (SGC-7901) and an orthotopic transplantation tumor model in nude mice to explore the specific mechanisms of 3-BrPA and SCT. We found that both 3-BrPA and SCT effectively suppressed cancer cell proliferation, arrested the cell cycle, induced apoptosis, and decreased the production of lactate and ATP. 3-BrPA significantly reduced the glycolytic enzyme hexokinase activity, while SCT selectively inhibited phosphofructokinase-1 activity. Furthermore, 3-BrPA and SCT upregulated the expression of pro-apoptotic proteins (Bax, cytochrome c, and cleaved caspase-3) and downregulated the expression of anti-apoptotic proteins (Bcl-2 and survivin). Finally, our animal model of gastric cancer indicated that intraperitoneal injection of 3-BrPA and SCT suppressed orthotopic transplantation tumor growth and induced tumor apoptosis. Taken together, these results suggest that 3-BrPA and SCT selectively suppress glycolytic enzymes, decrease ATP production, induce mitochondrial-mediated apoptosis, downregulate survivin, and inhibit tumor growth. Moreover, an intraperitoneal injection is an effective form of administration of 3-BrPA and SCT.

Novel Midkine Inhibitor iMDK Inhibits Tumor Growth and Angiogenesis in Oral Squamous Cell Carcinoma.

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Masui, Masanori; Okui, Tatsuo; Shimo, Tsuyoshi; Takabatake, Kiyofumi; Fukazawa, Takuya; Matsumoto, Kenichi; Kurio, Naito; Ibaragi, Soichiro; Naomoto, Yoshio; Nagatsuka, Hitoshi; Sasaki, Akira

2016-06-01

Midkine is a heparin-binding growth factor highly expressed in various human malignant tumors. However, its role in the growth of oral squamous cell carcinoma is not well understood. In this study, we analyzed the antitumor effect of a novel midkine inhibitor (iMDK) against oral squamous cell carcinoma. Administration of iMDK induced a robust antitumor response and suppressed cluster of differentiation 31 (CD31) expression in oral squamous cell carcinoma HSC-2 cells and SAS cells xenograft models. iMDK inhibited the proliferation of these cells dose-dependently, as well as the expression of midkine and phospho-extracellular signal-regulated kinase in HSC-2 and SAS cells. Moreover, iMDK significantly inhibited vascular endothelial growth factor and induced tube growth of human umbilical vein endothelial cells in a dose-dependent fashion. These findings suggest that midkine is critically involved in oral squamous cell carcinoma and iMDK can be effectively used for the treatment of oral squamous cell carcinoma. Copyright© 2016 International Institute of Anticancer Research (Dr. John G. Delinassios), All rights reserved.

Periostin Limits Tumor Response to VEGFA Inhibition

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Ioanna Keklikoglou

2018-03-01

Full Text Available Resistance to antiangiogenic drugs limits their applicability in cancer therapy. Here, we show that revascularization and progression of pancreatic neuroendocrine tumors (PNETs under extended vascular-endothelial growth factor A (VEGFA blockade are dependent on periostin (POSTN, a matricellular protein expressed by stromal cells. Genetic deletion of Postn in RIP1-Tag2 mice blunted tumor rebounds of M2-like macrophages and αSMA+ stromal cells in response to prolonged VEGFA inhibition and suppressed PNET revascularization and progression on therapy. POSTN deficiency also impeded the upregulation of basic fibroblast growth factor (FGF2, an adaptive mechanism previously implicated in PNET evasion from antiangiogenic therapy. Higher POSTN expression correlated with markers of M2-like macrophages in human PNETs, and depleting macrophages with a colony-stimulating factor 1 receptor (CSF1R antibody inhibited PNET revascularization and progression under VEGFA blockade despite continued POSTN production. These findings suggest a role for POSTN in orchestrating resistance to anti-VEGFA therapy in PNETs.

Inhibition effects of protein-conjugated amorphous zinc sulfide nanoparticles on tumor cells growth

International Nuclear Information System (INIS)

Cao Ying; Wang Huajie; Cao Cui; Sun Yuanyuan; Yang Lin; Wang Baoqing; Zhou Jianguo

2011-01-01

In this article, a facile and environmentally friendly method was applied to fabricate BSA-conjugated amorphous zinc sulfide (ZnS) nanoparticles using bovine serum albumin (BSA) as the matrix. Transmission electron microscopy analysis indicated that the stable and well-dispersed nanoparticles with the diameter of 15.9 ± 2.1 nm were successfully prepared. The energy dispersive X-ray, X-ray powder diffraction, Fourier transform infrared spectrograph, high resolution transmission electron microscope, and selected area electron diffraction measurements showed that the obtained nanoparticles had the amorphous structure and the coordination occurred between zinc sulfide surfaces and BSA in the nanoparticles. In addition, the inhibition effects of BSA-conjugated amorphous zinc sulfide nanoparticles on tumor cells growth were described in detail by cell viability analysis, optical and electron microscopy methods. The results showed that BSA-conjugated amorphous zinc sulfide nanoparticles could inhibit the metabolism and proliferation of human hepatocellular carcinoma cells, and the inhibition was dose dependent. The half maximal inhibitory concentration (IC50) was 0.36 mg/mL. Overall, this study suggested that BSA-conjugated amorphous zinc sulfide nanoparticles had the application potential as cytostatic agents and BSA in the nanoparticles could provide the modifiable site for the nanoparticles to improve their bioactivity or to endow them with the target function.

Effect of low frequency magnetic fields on melanoma: tumor inhibition and immune modulation

International Nuclear Information System (INIS)

Nie, Yunzhong; Du, Leilei; Mou, Yongbin; Xu, Zhenjun; Weng, Leihua; Du, Youwei; Zhu, Yanan; Hou, Yayi; Wang, Tingting

2013-01-01

We previously found that the low frequency magnetic fields (LF-MF) inhibited gastric and lung cancer cell growth. We suppose that exposure to LF-MF may modulate immune function so as to inhibit tumor. We here investigated whether LF-MF can inhibit the proliferation and metastasis of melanoma and influence immune function. The effect of MF on the proliferation, cell cycle and ultrastracture of B16-F10 in vitro was detected by cell counting Kit-8 assay, flow cytometry, and transmission electron microscopy. Lung metastasis mice were prepared by injection of 2 × 10 5 B16-F10 melanoma cells into the tail vein in C57BL/6 mice. The mice were then exposed to an LF-MF (0.4 T, 7.5 Hz) for 43 days. Survival rate, tumor markers and the innate and adaptive immune parameters were measured. The growth of B16-F10 cells was inhibited after exposure to the LF-MF. The inhibition was related to induction of cell cycle arrest and decomposition of chromatins. Moreover, the LF-MF prolonged the mouse survival rate and inhibited the proliferation of B16-F10 in melanoma metastasis mice model. Furthermore, the LF-MF modulated the immune response via regulation of immune cells and cytokine production. In addition, the number of Treg cells was decreased in mice with the LF-MF exposure, while the numbers of T cells as well as dendritic cells were significantly increased. LF-MF inhibited the growth and metastasis of melanoma cancer cells and improved immune function of tumor-bearing mice. This suggests that the inhibition may be attributed to modulation of LF-MF on immune function and LF-MF may be a potential therapy for treatment of melanoma

Sorafenib inhibits tumor growth and vascularization of rhabdomyosarcoma cells by blocking IGF-1R-mediated signaling

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Wessen Maruwge

2008-11-01

Full Text Available Wessen Maruwge1, Pádraig D’Arcy1, Annika Folin1,2, Slavica Brnjic1, Johan Wejde1, Anthony Davis1, Fredrik Erlandsson3, Jonas Bergh1,2, Bertha Brodin11Department of Oncology and Pathology, Karolinska Institutet, Stockholm, Sweden; 2Radiumhemmet, Karolinska University Hospital, Stockholm, Sweden; 3Bayer Pharmaceutical Corporation, SwedenAbstract: The growth of many soft tissue sarcomas is dependent on aberrant growth factor signaling, which promotes their proliferation and motility. With this in mind, we evaluated the effect of sorafenib, a receptor tyrosine kinase inhibitor, on cell growth and apoptosis in sarcoma cell lines of various histological subtypes. We found that sorafenib effectively inhibited cell proliferation in rhabdomyosarcoma, synovial sarcoma and Ewing’s sarcoma with IC50 values <5 µM. Sorafenib effectively induced growth arrest in rhabdomyosarcoma cells, which was concurrent with inhibition of Akt and Erk signaling. Studies of ligand-induced phosphorylation of Erk and Akt in rhabdomyosarcoma cells showed that insulin-like growth factor-1 is a potent activator, which can be blocked by treatment with sorafenib. In vivo sorafenib treatment of rhabdomyosarcoma xenografts had a significant inhibitory effect on tumor growth, which was associated with inhibited vascularization and enhanced necrosis in the adjacent tumor stroma. Our results demonstrate that in vitro and in vivo growth of rhabdomyosarcoma can be suppressed by treatment with sorafenib, and suggests the possibilities of using sorafenib as a potential adjuvant therapy for the treatment of rhabdomyosarcoma.Keywords: soft tissue sarcoma, kinase inhibitors, targeted therapy, vascularization

Inhibition of homologous recombination repair in irradiated tumor cells pretreated with Hsp90 inhibitor 17-allylamino-17-demethoxygeldanamycin

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Noguchi, Miho; Yu, Dong; Hirayama, Ryoichi; Ninomiya, Yasuharu; Sekine, Emiko; Kubota, Nobuo; Ando, Koichi; Okayasu, Ryuichi

2006-01-01

In order to investigate the mechanism of radio-sensitization by an Hsp90 inhibitor 17-allylamino-17-demethoxygeldanamycin (17-AAG), we studied repair of DNA double strand breaks (DSBs) in irradiated human cells pre-treated with 17-AAG. DSBs are thought to be the critical target for radiation-induced cell death. Two human tumor cell lines DU145 and SQ-5 which showed clear radio-sensitization by 17-AAG revealed a significant inhibition of DSB repair, while normal human cells which did not show radio-sensitization by the drug indicated no change in the DSB repair kinetics with 17-AAG. We further demonstrated that BRCA2 was a novel client protein for Hsp90, and 17-AAG caused the degradation of BRCA2 and in turn altered the behavior of Rad51, a critical protein for homologous recombination (HR) pathway of DSB repair. Our data demonstrate for the first time that 17-AAG inhibits the HR repair process and could provide a new therapeutic strategy to selectively result in higher tumor cell killing

NF-κB functions as a molecular link between tumor cells and Th1/Tc1 T cells in the tumor microenvironment to exert radiation-mediated tumor suppression

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Simon, Priscilla S.; Bardhan, Kankana; Chen, May R.; Paschall, Amy V.; Lu, Chunwan; Bollag, Roni J.; Kong, Feng-Chong; Jin, JianYue; Kong, Feng-Ming; Waller, Jennifer L.; Pollock, Raphael E.; Liu, Kebin

2016-01-01

Radiation modulates both tumor cells and immune cells in the tumor microenvironment to exert its anti-tumor activity; however, the molecular connection between tumor cells and immune cells that mediates radiation-exerted tumor suppression activity in the tumor microenvironment is largely unknown. We report here that radiation induces rapid activation of the p65/p50 and p50/p50 NF-κB complexes in human soft tissue sarcoma (STS) cells. Radiation-activated p65/p50 and p50/p50 bind to the TNFα promoter to activate its transcription in STS cells. Radiation-induced TNFα induces tumor cell death in an autocrine manner. A sublethal dose of Smac mimetic BV6 induces cIAP1 and cIAP2 degradation to increase tumor cell sensitivity to radiation-induced cell death in vitro and to enhance radiation-mediated suppression of STS xenografts in vivo. Inhibition of caspases, RIP1, or RIP3 blocks radiation/TNFα-induced cell death, whereas inhibition of RIP1 blocks TNFα-induced caspase activation, suggesting that caspases and RIP1 act sequentially to mediate the non-compensatory cell death pathways. Furthermore, we determined in a syngeneic sarcoma mouse model that radiation up-regulates IRF3, IFNβ, and the T cell chemokines CCL2 and CCL5 in the tumor microenvironment, which are associated with activation and increased infiltration of Th1/Tc1 T cells in the tumor microenvironment. Moreover, tumor-infiltrating T cells are in their active form since both the perforin and FasL pathways are activated in irradiated tumor tissues. Consequently, combined BV6 and radiation completely suppressed tumor growth in vivo. Therefore, radiation-induced NF-κB functions as a molecular link between tumor cells and immune cells in the tumor microenvironment for radiation-mediated tumor suppression. PMID:27014915

Anti-tumor therapy with macroencapsulated endostatin producer cells

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Balduino Keli N

2010-03-01

Full Text Available Abstract Background Theracyte is a polytetrafluoroethylene membrane macroencapsulation system designed to induce neovascularization at the tissue interface, protecting the cells from host's immune rejection, thereby circumventing the problem of limited half-life and variation in circulating levels. Endostatin is a potent inhibitor of angiogenesis and tumor growth. Continuous delivery of endostatin improves the efficacy and potency of the antitumoral therapy. The purpose of this study was to determine whether recombinant fibroblasts expressing endostatin encapsulated in Theracyte immunoisolation devices can be used for delivery of this therapeutic protein for treatment of mice bearing B16F10 melanoma and Ehrlich tumors. Results Mice were inoculated subcutaneously with melanoma (B16F10 cells or Ehrlich tumor cells at the foot pads. Treatment began when tumor thickness had reached 0.5 mm, by subcutaneous implantation of 107 recombinant encapsulated or non-encapsulated endostatin producer cells. Similar melanoma growth inhibition was obtained for mice treated with encapsulated or non-encapsulated endostatin-expressing cells. The treatment of mice bearing melanoma tumor with encapsulated endostatin-expressing cells was decreased by 50.0%, whereas a decrease of 56.7% in tumor thickness was obtained for mice treated with non-encapsulated cells. Treatment of Ehrlich tumor-bearing mice with non-encapsulated endostatin-expressing cells reduced tumor thickness by 52.4%, whereas lower tumor growth inhibition was obtained for mice treated with encapsulated endostatin-expressing cells: 24.2%. Encapsulated endostatin-secreting fibroblasts failed to survive until the end of the treatment. However, endostatin release from the devices to the surrounding tissues was confirmed by immunostaining. Decrease in vascular structures, functional vessels and extension of the vascular area were observed in melanoma microenvironments. Conclusions This study indicates that

Anti-tumor therapy with macroencapsulated endostatin producer cells.

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Rodrigues, Danielle B; Chammas, Roger; Malavasi, Natália V; da Costa, Patrícia L N; Chura-Chambi, Rosa M; Balduino, Keli N; Morganti, Ligia

2010-03-02

Theracyte is a polytetrafluoroethylene membrane macroencapsulation system designed to induce neovascularization at the tissue interface, protecting the cells from host's immune rejection, thereby circumventing the problem of limited half-life and variation in circulating levels. Endostatin is a potent inhibitor of angiogenesis and tumor growth. Continuous delivery of endostatin improves the efficacy and potency of the antitumoral therapy. The purpose of this study was to determine whether recombinant fibroblasts expressing endostatin encapsulated in Theracyte immunoisolation devices can be used for delivery of this therapeutic protein for treatment of mice bearing B16F10 melanoma and Ehrlich tumors. Mice were inoculated subcutaneously with melanoma (B16F10 cells) or Ehrlich tumor cells at the foot pads. Treatment began when tumor thickness had reached 0.5 mm, by subcutaneous implantation of 107 recombinant encapsulated or non-encapsulated endostatin producer cells. Similar melanoma growth inhibition was obtained for mice treated with encapsulated or non-encapsulated endostatin-expressing cells. The treatment of mice bearing melanoma tumor with encapsulated endostatin-expressing cells was decreased by 50.0%, whereas a decrease of 56.7% in tumor thickness was obtained for mice treated with non-encapsulated cells. Treatment of Ehrlich tumor-bearing mice with non-encapsulated endostatin-expressing cells reduced tumor thickness by 52.4%, whereas lower tumor growth inhibition was obtained for mice treated with encapsulated endostatin-expressing cells: 24.2%. Encapsulated endostatin-secreting fibroblasts failed to survive until the end of the treatment. However, endostatin release from the devices to the surrounding tissues was confirmed by immunostaining. Decrease in vascular structures, functional vessels and extension of the vascular area were observed in melanoma microenvironments. This study indicates that immunoisolation devices containing endostatin

SAR405, a PIK3C3/Vps34 inhibitor that prevents autophagy and synergizes with MTOR inhibition in tumor cells.

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Pasquier, Benoit

2015-04-03

Autophagy plays an important role in cancer and it has been suggested that it functions not only as a tumor suppressor pathway to prevent tumor initiation, but also as a prosurvival pathway that helps tumor cells endure metabolic stress and resist death triggered by chemotherapeutic agents. We recently described the discovery of inhibitors of PIK3C3/Vps34 (phosphatidylinositol 3-kinase, catalytic subunit type 3), the lipid kinase component of the class III phosphatidylinositol 3-kinase (PtdIns3K). This PtdIns3K isoform has attracted significant attention in recent years because of its role in autophagy. Following chemical optimization we identified SAR405, a low molecular mass kinase inhibitor of PIK3C3, highly potent and selective with regard to other lipid and protein kinases. We demonstrated that inhibiting the catalytic activity of PIK3C3 disrupts vesicle trafficking from late endosomes to lysosomes. SAR405 treatment also inhibits autophagy induced either by starvation or by MTOR (mechanistic target of rapamycin) inhibition. Finally our results show that combining SAR405 with everolimus, the FDA-approved MTOR inhibitor, results in a significant synergy on the reduction of cell proliferation using renal tumor cells. This result indicates a potential therapeutic application for PIK3C3 inhibitors in cancer.

CYP24A1 inhibition facilitates the anti-tumor effect of vitamin D3 on colorectal cancer cells

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Kósa, János P; Horváth, Péter; Wölfling, János; Kovács, Dóra; Balla, Bernadett; Mátyus, Péter; Horváth, Evelin; Speer, Gábor; Takács, István; Nagy, Zsolt; Horváth, Henrik; Lakatos, Péter

2013-01-01

AIM: The effects of vitamin D3 have been investigated on various tumors, including colorectal cancer (CRC). 25-hydroxyvitamin-D3-24-hydroxylase (CYP24A1), the enzyme that inactivates the active vitamin D3 metabolite 1,25-dihydroxyvitamin D3 (1,25-D3), is considered to be the main enzyme determining the biological half-life of 1,25-D3. During colorectal carcinogenesis, the expression and concentration of CYP24A1 increases significantly, suggesting that this phenomenon could be responsible for the proposed efficacy of 1,25-D3 in the treatment of CRC. The aim of this study was to investigate the anti-tumor effects of vitamin D3 on the human CRC cell line Caco-2 after inhibition of the cytochrome P450 component of CYP24A1 activity. METHODS: We examined the expression of CYP24A1 mRNA and the effects of 1,25-D3 on the cell line Caco-2 after inhibition of CYP24A1. Cell viability and proliferation were determined by means of sulforhodamine-B staining and bromodeoxyuridine incorporation, respectively, while cytotoxicity was estimated via the lactate dehydrogenase content of the cell culture supernatant. CYP24A1 expression was measured by real-time reverse transcription polymerase chain reaction. A number of tetralone compounds were synthesized to investigate their CP24A1 inhibitory activity. RESULTS: In response to 1,25-D3, CYP24A1 mRNA expression was enhanced significantly, in a time- and dose-dependent manner. Caco-2 cell viability and proliferation were not influenced by the administration of 1,25-D3 alone, but were markedly reduced by co-administration of 1,25-D3 and KD-35, a CYP24A1-inhibiting tetralone. Our data suggest that the mechanism of action of co-administered KD-35 and 1,25-D3 does not involve a direct cytotoxic effect, but rather the inhibition of cell proliferation. CONCLUSION: These findings demonstrate that the selective inhibition of CYP24A1 by compounds such as KD-35 may be a new approach for enhancement of the anti-tumor effect of 1,25-D3 on CRC. PMID

Osteoprotegerin inhibits bone resorption and prevents tumor development in a xenogenic model of Ewing's sarcoma by inhibiting RANKL

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Picarda, Gaëlle; Matous, Etienne; Amiaud, Jérôme; Charrier, Céline; Lamoureux, François; Heymann, Marie-Françoise; Tirode, Franck; Pitard, Bruno; Trichet, Valérie; Heymann, Dominique; Redini, Françoise

2013-01-01

Ewing's sarcoma (ES) associated with high osyeolytic lesions typically arises in the bones of children and adolescents. The development of multi-disciplinary therapy has increased current long-term survival rates to greater than 50% but only 20% for high risk group patients (relapse, metastases, etc.). Among new therapeutic approaches, osteoprotegerin (OPG), an anti-bone resorption molecule may represent a promising candidate to inhibit RANKL-mediated osteolytic component of ES and consequently to limit the tumor development. Xenogenic orthotopic models of Ewing's sarcoma were induced by intra-osseous injection of human TC-71 ES cells. OPG was administered in vivo by non-viral gene transfer using an amphiphilic non ionic block copolymer. ES bearing mice were assigned to controls (no treatment, synthetic vector alone or F68/empty pcDNA3.1 plasmid) and hOPG treated groups. A substantial but not significant inhibition of tumor development was observed in the hOPG group as compared to control groups. Marked bone lesions were revealed by micro-computed tomography analyses in control groups whereas a normal bone micro-architecture was preserved in the hOPG treated group. RANKL over-expressed in ES animal model was expressed by tumor cells rather than by host cells. However, TRAIL present in the tumor microenvironment may interfere with OPG effect on tumor development and bone remodeling via RANKL inhibition. In conclusion, the use of a xenogenic model of Ewing's sarcoma allowed discriminating between the tumor and host cells responsible for the elevation of RANKL production observed in this tumor and demonstrated the relevance of blocking RANKL by OPG as a promising therapy in ES. PMID:26909278

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

Cigarette smoke alters the invariant natural killer T cell function and may inhibit anti-tumor responses.

LENUS (Irish Health Repository)

Hogan, Andrew E

2011-09-01

Invariant natural killer T (iNKT) cells are a minor subset of human T cells which express the invariant T cell receptor Vα24 Jα18 and recognize glycolipids presented on CD1d. Invariant NKT cells are important immune regulators and can initiate anti-tumor responses through early potent cytokine production. Studies show that iNKT cells are defective in certain cancers. Cigarette smoke contains many carcinogens and is implicated directly and indirectly in many cancers. We investigated the effects of cigarette smoke on the circulating iNKT cell number and function. We found that the iNKT cell frequency is significantly reduced in cigarette smoking subjects. Invariant NKT cells exposed to cigarette smoke extract (CSE) showed significant defects in cytokine production and the ability to kill target cells. CSE inhibits the upregulation of CD107 but not CD69 or CD56 on iNKT cells. These findings suggest that CSE has a specific effect on iNKT cell anti-tumor responses, which may contribute to the role of smoking in the development of cancer.

Methionine enkephalin (MENK) inhibits tumor growth through regulating CD4+Foxp3+ regulatory T cells (Tregs) in mice.

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Li, Xuan; Meng, Yiming; Plotnikoff, Nicolas P; Youkilis, Gene; Griffin, Noreen; Wang, Enhua; Lu, Changlong; Shan, Fengping

2015-01-01

Methionine enkephalin (MENK), an endogenous neuropeptide, plays an crucial role in both neuroendocrine and immune systems. CD4+Foxp3+ regulatory T cells (Tregs) are identified as a major subpopulation of T lymphocytes in suppressing immune system to keep balanced immunity. The aim of this research work was to elucidate the mechanisms via which MENK interacts with Tregs in cancer situation. The influence of MENK on transforming growth factor-β (TGF-β) mediated conversion from naïve CD4+CD25- T cells to CD4+CD25+ Tregs was determined and the data from flow cytometry (FCM) analysis indicated that MENK effectively inhibited the expression of Foxp3 during the process of TGF-βinduction. Furthermore, this inhibiting process was accompanied by diminishing phosphorylation and nuclear translocation of Smad2/3, confirmed by western blot (WB) analysis and immunofluorescence (IF) at molecular level. We established sarcoma mice model with S180 to investigate whether MENK could modulate Tregs in tumor circumstance. Our findings showed that MENK delayed the development of tumor in S180 tumor bearing mice and down-regulated level of Tregs. Together, these novel findings reached a conclusion that MENK could inhibit Tregs activity directly and retard tumor development through down-regulating Tregs in mice. This work advances the deepening understanding of the influence of MENK on Tregs in cancer situation, and relation of MENK with immune system, supporting the implication of MENK as a new strategy for cancer immunotherapy.

Betulinic acid inhibits colon cancer cell and tumor growth and induces proteasome-dependent and -independent downregulation of specificity proteins (Sp transcription factors

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Pathi Satya

2011-08-01

Full Text Available Abstract Background Betulinic acid (BA inhibits growth of several cancer cell lines and tumors and the effects of BA have been attributed to its mitochondriotoxicity and inhibition of multiple pro-oncogenic factors. Previous studies show that BA induces proteasome-dependent degradation of specificity protein (Sp transcription factors Sp1, Sp3 and Sp4 in prostate cancer cells and this study focused on the mechanism of action of BA in colon cancer cells. Methods The effects of BA on colon cancer cell proliferation and apoptosis and tumor growth in vivo were determined using standardized assays. The effects of BA on Sp proteins and Sp-regulated gene products were analyzed by western blots, and real time PCR was used to determine microRNA-27a (miR-27a and ZBTB10 mRNA expression. Results BA inhibited growth and induced apoptosis in RKO and SW480 colon cancer cells and inhibited tumor growth in athymic nude mice bearing RKO cells as xenograft. BA also decreased expression of Sp1, Sp3 and Sp4 transcription factors which are overexpressed in colon cancer cells and decreased levels of several Sp-regulated genes including survivin, vascular endothelial growth factor, p65 sub-unit of NFκB, epidermal growth factor receptor, cyclin D1, and pituitary tumor transforming gene-1. The mechanism of action of BA was dependent on cell context, since BA induced proteasome-dependent and proteasome-independent downregulation of Sp1, Sp3 and Sp4 in SW480 and RKO cells, respectively. In RKO cells, the mechanism of BA-induced repression of Sp1, Sp3 and Sp4 was due to induction of reactive oxygen species (ROS, ROS-mediated repression of microRNA-27a, and induction of the Sp repressor gene ZBTB10. Conclusions These results suggest that the anticancer activity of BA in colon cancer cells is due, in part, to downregulation of Sp1, Sp3 and Sp4 transcription factors; however, the mechanism of this response is cell context-dependent.

Betulinic acid inhibits colon cancer cell and tumor growth and induces proteasome-dependent and -independent downregulation of specificity proteins (Sp) transcription factors

International Nuclear Information System (INIS)

Chintharlapalli, Sudhakar; Papineni, Sabitha; Lei, Ping; Pathi, Satya; Safe, Stephen

2011-01-01

Betulinic acid (BA) inhibits growth of several cancer cell lines and tumors and the effects of BA have been attributed to its mitochondriotoxicity and inhibition of multiple pro-oncogenic factors. Previous studies show that BA induces proteasome-dependent degradation of specificity protein (Sp) transcription factors Sp1, Sp3 and Sp4 in prostate cancer cells and this study focused on the mechanism of action of BA in colon cancer cells. The effects of BA on colon cancer cell proliferation and apoptosis and tumor growth in vivo were determined using standardized assays. The effects of BA on Sp proteins and Sp-regulated gene products were analyzed by western blots, and real time PCR was used to determine microRNA-27a (miR-27a) and ZBTB10 mRNA expression. BA inhibited growth and induced apoptosis in RKO and SW480 colon cancer cells and inhibited tumor growth in athymic nude mice bearing RKO cells as xenograft. BA also decreased expression of Sp1, Sp3 and Sp4 transcription factors which are overexpressed in colon cancer cells and decreased levels of several Sp-regulated genes including survivin, vascular endothelial growth factor, p65 sub-unit of NFκB, epidermal growth factor receptor, cyclin D1, and pituitary tumor transforming gene-1. The mechanism of action of BA was dependent on cell context, since BA induced proteasome-dependent and proteasome-independent downregulation of Sp1, Sp3 and Sp4 in SW480 and RKO cells, respectively. In RKO cells, the mechanism of BA-induced repression of Sp1, Sp3 and Sp4 was due to induction of reactive oxygen species (ROS), ROS-mediated repression of microRNA-27a, and induction of the Sp repressor gene ZBTB10. These results suggest that the anticancer activity of BA in colon cancer cells is due, in part, to downregulation of Sp1, Sp3 and Sp4 transcription factors; however, the mechanism of this response is cell context-dependent

Phenotypic and Functional Properties of Tumor-Infiltrating Regulatory T Cells

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Gap Ryol Lee

2017-01-01

Full Text Available Regulatory T (Treg cells maintain immune homeostasis by suppressing excessive immune responses. Treg cells induce tolerance against self- and foreign antigens, thus preventing autoimmunity, allergy, graft rejection, and fetus rejection during pregnancy. However, Treg cells also infiltrate into tumors and inhibit antitumor immune responses, thus inhibiting anticancer therapy. Depleting whole Treg cell populations in the body to enhance anticancer treatments will produce deleterious autoimmune diseases. Therefore, understanding the precise nature of tumor-infiltrating Treg cells is essential for effectively targeting Treg cells in tumors. This review summarizes recent results relating to Treg cells in the tumor microenvironment, with particular emphasis on their accumulation, phenotypic, and functional properties, and targeting to enhance the efficacy of anticancer treatment.

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.

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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

Dll4 blockade potentiates the anti-tumor effects of VEGF inhibition in renal cell carcinoma patient-derived xenografts.

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Kiersten Marie Miles

Full Text Available The Notch ligand Delta-like 4 (Dll4 is highly expressed in vascular endothelium and has been shown to play a pivotal role in regulating tumor angiogenesis. Blockade of the Dll4-Notch pathway in preclinical cancer models has been associated with non-productive angiogenesis and reduced tumor growth. Given the cross-talk between the vascular endothelial growth factor (VEGF and Delta-Notch pathways in tumor angiogenesis, we examined the activity of a function-blocking Dll4 antibody, REGN1035, alone and in combination with anti-VEGF therapy in renal cell carcinoma (RCC.Severe combined immunodeficiency (SCID mice bearing patient-derived clear cell RCC xenografts were treated with REGN1035 and in combination with the multi-targeted tyrosine kinase inhibitor sunitinib or the VEGF blocker ziv-aflibercept. Immunohistochemical and immunofluorescent analyses were carried out, as well as magnetic resonance imaging (MRI examinations pre and 24 hours and 2 weeks post treatment. Single agent treatment with REGN1035 resulted in significant tumor growth inhibition (36-62% that was equivalent to or exceeded the single agent anti-tumor activity of the VEGF pathway inhibitors sunitinib (38-54% and ziv-aflibercept (46%. Importantly, combination treatments with REGN1035 plus VEGF inhibitors resulted in enhanced anti-tumor effects (72-80% growth inhibition, including some tumor regression. Magnetic resonance imaging showed a marked decrease in tumor perfusion in all treatment groups. Interestingly, anti-tumor efficacy of the combination of REGN1035 and ziv-aflibercept was also observed in a sunitinib resistant ccRCC model.Overall, these findings demonstrate the potent anti-tumor activity of Dll4 blockade in RCC patient-derived tumors and a combination benefit for the simultaneous targeting of the Dll4 and VEGF signaling pathways, highlighting the therapeutic potential of this treatment modality in RCC.

Periostin Limits Tumor Response to VEGFA Inhibition.

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Keklikoglou, Ioanna; Kadioglu, Ece; Bissinger, Stefan; Langlois, Benoît; Bellotti, Axel; Orend, Gertraud; Ries, Carola H; De Palma, Michele

2018-03-06

Resistance to antiangiogenic drugs limits their applicability in cancer therapy. Here, we show that revascularization and progression of pancreatic neuroendocrine tumors (PNETs) under extended vascular-endothelial growth factor A (VEGFA) blockade are dependent on periostin (POSTN), a matricellular protein expressed by stromal cells. Genetic deletion of Postn in RIP1-Tag2 mice blunted tumor rebounds of M2-like macrophages and αSMA + stromal cells in response to prolonged VEGFA inhibition and suppressed PNET revascularization and progression on therapy. POSTN deficiency also impeded the upregulation of basic fibroblast growth factor (FGF2), an adaptive mechanism previously implicated in PNET evasion from antiangiogenic therapy. Higher POSTN expression correlated with markers of M2-like macrophages in human PNETs, and depleting macrophages with a colony-stimulating factor 1 receptor (CSF1R) antibody inhibited PNET revascularization and progression under VEGFA blockade despite continued POSTN production. These findings suggest a role for POSTN in orchestrating resistance to anti-VEGFA therapy in PNETs. Copyright © 2018 The Author(s). Published by Elsevier Inc. All rights reserved.

Involvement of host stroma cells and tissue fibrosis in pancreatic tumor development in transgenic mice.

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Itai Spector

Full Text Available INTRODUCTION: Stroma cells and extracellular matrix (ECM components provide the pivotal microenvironment for tumor development. The study aimed to evaluate the importance of the pancreatic stroma for tumor development. METHODS: Pancreatic tumor cells were implanted subcutaneously into green fluorescent protein transgenic mice, and stroma cells invading the tumors were identified through immunohistochemistry. Inhibition of tumor invasion by stroma cells was achieved with halofuginone, an inhibitor of TGFβ/Smad3 signaling, alone or in combination with chemotherapy. The origin of tumor ECM was evaluated with species-specific collagen I antibodies and in situ hybridization of collagen α1(I gene. Pancreatic fibrosis was induced by cerulean injection and tumors by spleen injection of pancreatic tumor cells. RESULTS: Inhibition of stroma cell infiltration and reduction of tumor ECM levels by halofuginone inhibited development of tumors derived from mouse and human pancreatic cancer cells. Halofuginone reduced the number only of stroma myofibroblasts expressing both contractile and collagen biosynthesis markers. Both stroma myofibroblasts and tumor cells generated ECM that contributes to tumor growth. Combination of treatments that inhibit stroma cell infiltration, cause apoptosis of myofibroblasts and inhibit Smad3 phosphorylation, with chemotherapy that increases tumor-cell apoptosis without affecting Smad3 phosphorylation was more efficacious than either treatment alone. More tumors developed in fibrotic than in normal pancreas, and prevention of tissue fibrosis greatly reduced tumor development. CONCLUSIONS: The utmost importance of tissue fibrosis and of stroma cells for tumor development presents potential new therapy targets, suggesting combination therapy against stroma and neoplastic cells as a treatment of choice.

Inhibition of Notch signaling alters the phenotype of orthotopic tumors formed from glioblastoma multiforme neurosphere cells but does not hamper intracranial tumor growth regardless of endogene Notch pathway signature

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Kristoffersen, Karina; Nedergaard, Mette Kjølhede; Villingshøj, Mette

2014-01-01

BACKGROUND: Brain cancer stem-like cells (bCSC) are cancer cells with neural stem cell (NSC)-like properties found in the devastating brain tumor glioblastoma multiforme (GBM). bCSC are proposed a central role in tumor initiation, progression, treatment resistance and relapse and as such present...... a promising target in GBM research. The Notch signaling pathway is often deregulated in GBM and we have previously characterized GBM-derived bCSC cultures based on their expression of the Notch-1 receptor and found that it could be used as predictive marker for the effect of Notch inhibition. The aim...... of the present project was therefore to further elucidate the significance of Notch pathway activity for the tumorigenic properties of GBM-derived bCSC. METHODS: Human-derived GBM xenograft cells previously established as NSC-like neurosphere cultures were used. Notch inhibition was accomplished by exposing...

Inhibition of HSP27 alone or in combination with pAKT inhibition as therapeutic approaches to target SPARC-induced glioma cell survival

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Schultz Chad R

2012-04-01

Full Text Available Abstract Background The current treatment regimen for glioma patients is surgery, followed by radiation therapy plus temozolomide (TMZ, followed by 6 months of adjuvant TMZ. Despite this aggressive treatment regimen, the overall survival of all surgically treated GBM patients remains dismal, and additional or different therapies are required. Depending on the cancer type, SPARC has been proposed both as a therapeutic target and as a therapeutic agent. In glioma, SPARC promotes invasion via upregulation of the p38 MAPK/MAPKAPK2/HSP27 signaling pathway, and promotes tumor cell survival by upregulating pAKT. As HSP27 and AKT interact to regulate the activity of each other, we determined whether inhibition of HSP27 was better than targeting SPARC as a therapeutic approach to inhibit both SPARC-induced glioma cell invasion and survival. Results Our studies found the following. 1 SPARC increases the expression of tumor cell pro-survival and pro-death protein signaling in balance, and, as a net result, tumor cell survival remains unchanged. 2 Suppressing SPARC increases tumor cell survival, indicating it is not a good therapeutic target. 3 Suppressing HSP27 decreases tumor cell survival in all gliomas, but is more effective in SPARC-expressing tumor cells due to the removal of HSP27 inhibition of SPARC-induced pro-apoptotic signaling. 4 Suppressing total AKT1/2 paradoxically enhanced tumor cell survival, indicating that AKT1 or 2 are poor therapeutic targets. 5 However, inhibiting pAKT suppresses tumor cell survival. 6 Inhibiting both HSP27 and pAKT synergistically decreases tumor cell survival. 7 There appears to be a complex feedback system between SPARC, HSP27, and AKT. 8 This interaction is likely influenced by PTEN status. With respect to chemosensitization, we found the following. 1 SPARC enhances pro-apoptotic signaling in cells exposed to TMZ. 2 Despite this enhanced signaling, SPARC protects cells against TMZ. 3 This protection can be reduced

Inhibition of Epidermal Growth Factor Receptor and Vascular Endothelial Growth Factor Receptor Phosphorylation on Tumor-Associated Endothelial Cells Leads to Treatment of Orthotopic Human Colon Cancer in Nude Mice

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Takamitsu Sasaki

2007-12-01

Full Text Available The purpose of our study was to determine whether the dual inhibition of epidermal growth factor receptor (EGFR and vascular endothelial growth factor receptor (VEGFR signaling pathways in tumor-associated endothelial cells can inhibit the progressive growth of human colon carcinoma in the cecum of nude mice. SW620CE2 human colon cancer cells growing in culture and orthotopically in the cecum of nude mice expressed a high level of transforming growth factor alpha (TGF-α and vascular endothelial growth factor (VEGF but were negative for EGFR, human epidermal growth factor receptor 2 (HER2, VEGFR. Double immunofluorescence staining revealed that tumorassociated endothelial cells expressed EGFR, VEGFR2, phosphorylated EGFR (pEGFR, phosphorylated VEGFR (pVEGFR. Treatment of mice with either 7H-pyrrolo [2,3-d]-pyrimidine lead scaffold (AEE788; an inhibitor of EGFR and VEGFR tyrosine kinase or CPT-11 as single agents significantly inhibited the growth of cecal tumors (P < .01; this decrease was even more pronounced with AEE788 combined with CPT-11 (P < .001. AEE788 alone or combined with CPT-11 also inhibited the expression of pEGFR and pVEGFR on tumor-associated endothelial cells, significantly decreased vascularization and tumor cell proliferation, increased the level of apoptosis in both tumorassociated endothelial cells and tumor cells. These data demonstrate that targeting EGFR and VEGFR signaling on tumor-associated endothelial cells provides a viable approach for the treatment of colon cancer.

Inhibition of metastatic tumor growth in mouse lung by repeated administration of polyethylene glycol-conjugated catalase: quantitative analysis with firefly luciferase-expressing melanoma cells.

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Hyoudou, Kenji; Nishikawa, Makiya; Umeyama, Yukari; Kobayashi, Yuki; Yamashita, Fumiyoshi; Hashida, Mitsuru

2004-11-15

To develop a novel and effective approach to inhibit tumor metastasis based on controlled delivery of catalase, we first evaluated the characteristics of the disposition and proliferation of tumor cells. Then, we examined the effects of polyethylene glycol-conjugated catalase (PEG-catalase) on tumor metastasis. On the basis of the results obtained, PEG-catalase was repetitively administered to completely suppress the growth of tumor cells. Murine melanoma B16-BL6 cells were stably transfected with firefly luciferase gene to obtain B16-BL6/Luc cells. These cells were injected intravenously into syngeneic C57BL/6 mice. PEG-catalase was injected intravenously, and the effect was evaluated by measuring the luciferase activity as the indicator of the number of tumor cells. At 1 hour after injection of B16-BL6/Luc cells, 60 to 90% of the injected cells were recovered in the lung. The numbers decreased to 2 to 4% at 24 hours, then increased. An injection of PEG-catalase just before inoculation significantly reduced the number of tumor cells at 24 hours. Injection of PEG-catalase at 1 or 3 days after inoculation was also effective in reducing the cell numbers. Daily dosing of PEG-catalase greatly inhibited the proliferation and the number assayed at 14 days after inoculation was not significantly different from the minimal number observed at 1 day, suggesting that the growth had been markedly suppressed by the treatment. These findings indicate that sustained catalase activity in the blood circulation can prevent the multiple processes of tumor metastasis in the lung, which could lead to a state of tumor dormancy.

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.

Picropodophyllin inhibits tumor growth of human nasopharyngeal carcinoma in a mouse model

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Yin, Shu-Cheng; Guo, Wei; Tao, Ze-Zhang

2013-01-01

Highlights: •We identified that PPP inhibits IGF-1R/Akt pathway in NPC cells. •PPP dose-dependently inhibits NPC cell proliferation in vitro. •PPP suppresses tumor growth of NPC in nude mice. •PPP have little effect on microtubule assembly. -- Abstract: Insulin-like growth factor-1 receptor (IGF-1R) is a cell membrane receptor with tyrosine kinase activity and plays important roles in cell transformation, tumor growth, tumor invasion, and metastasis. Picropodophyllin (PPP) is a selective IGF-1R inhibitor and shows promising antitumor effects for several human cancers. However, its antitumor effects in nasopharyngeal carcinoma (NPC) remain unclear. The purpose of this study is to investigate the antitumor activity of PPP in NPC using in vitro cell culture and in vivo animal model. We found that PPP dose-dependently decreased the IGF-induced phosphorylation and activity of IGF-1R and consequently reduced the phosphorylation of Akt, one downstream target of IGF-1R. In addition, PPP inhibited NPC cell proliferation in vitro. The half maximal inhibitory concentration (IC50) of PPP for NPC cell line CNE-2 was ⩽1 μM at 24 h after treatment and ⩽0.5 μM at 48 h after treatment, respectively. Moreover, administration of PPP by intraperitoneal injection significantly suppressed the tumor growth of xenografted NPC in nude mice. Taken together, these results suggest targeting IGF-1R by PPP may represent a new strategy for treatment of NPCs with positive IGF-1R expression

Picropodophyllin inhibits tumor growth of human nasopharyngeal carcinoma in a mouse model

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Yin, Shu-Cheng [Department of Otolaryngology – Head and Neck Surgery, Renmin Hospital of Wuhan University, Wuhan 430060 (China); Department of Otolaryngology – Head and Neck Surgery, Zhongnan Hospital of Wuhan University, Wuhan 430071 (China); Guo, Wei [Department of Otolaryngology – Head and Neck Surgery, Zhongnan Hospital of Wuhan University, Wuhan 430071 (China); Tao, Ze-Zhang, E-mail: zezhangtao@gmail.com [Department of Otolaryngology – Head and Neck Surgery, Renmin Hospital of Wuhan University, Wuhan 430060 (China)

2013-09-13

Highlights: •We identified that PPP inhibits IGF-1R/Akt pathway in NPC cells. •PPP dose-dependently inhibits NPC cell proliferation in vitro. •PPP suppresses tumor growth of NPC in nude mice. •PPP have little effect on microtubule assembly. -- Abstract: Insulin-like growth factor-1 receptor (IGF-1R) is a cell membrane receptor with tyrosine kinase activity and plays important roles in cell transformation, tumor growth, tumor invasion, and metastasis. Picropodophyllin (PPP) is a selective IGF-1R inhibitor and shows promising antitumor effects for several human cancers. However, its antitumor effects in nasopharyngeal carcinoma (NPC) remain unclear. The purpose of this study is to investigate the antitumor activity of PPP in NPC using in vitro cell culture and in vivo animal model. We found that PPP dose-dependently decreased the IGF-induced phosphorylation and activity of IGF-1R and consequently reduced the phosphorylation of Akt, one downstream target of IGF-1R. In addition, PPP inhibited NPC cell proliferation in vitro. The half maximal inhibitory concentration (IC50) of PPP for NPC cell line CNE-2 was ⩽1 μM at 24 h after treatment and ⩽0.5 μM at 48 h after treatment, respectively. Moreover, administration of PPP by intraperitoneal injection significantly suppressed the tumor growth of xenografted NPC in nude mice. Taken together, these results suggest targeting IGF-1R by PPP may represent a new strategy for treatment of NPCs with positive IGF-1R expression.

Cdk5 phosphorylates non-genotoxically overexpressed p53 following inhibition of PP2A to induce cell cycle arrest/apoptosis and inhibits tumor progression

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Kumari Ratna

2010-07-01

Full Text Available Abstract Background p53 is the most studied tumor suppressor and its overexpression may or may not cause cell death depending upon the genetic background of the cells. p53 is degraded by human papillomavirus (HPV E6 protein in cervical carcinoma. Several stress activated kinases are known to phosphorylate p53 and, among them cyclin dependent kinase 5 (Cdk5 is one of the kinase studied in neuronal cell system. Recently, the involvement of Cdk5 in phosphorylating p53 has been shown in certain cancer types. Phosphorylation at specific serine residues in p53 is essential for it to cause cell growth inhibition. Activation of p53 under non stress conditions is poorly understood. Therefore, the activation of p53 and detection of upstream kinases that phosphorylate non-genotoxically overexpressed p53 will be of therapeutic importance for cancer treatment. Results To determine the non-genotoxic effect of p53; Tet-On system was utilized and p53 inducible HPV-positive HeLa cells were developed. p53 overexpression in HPV-positive cells did not induce cell cycle arrest or apoptosis. However, we demonstrate that overexpressed p53 can be activated to upregulate p21 and Bax which causes G2 arrest and apoptosis, by inhibiting protein phosphatase 2A. Additionally, we report that the upstream kinase cyclin dependent kinase 5 interacts with p53 to phosphorylate it at Serine20 and Serine46 residues thereby promoting its recruitment on p21 and bax promoters. Upregulation and translocation of Bax causes apoptosis through intrinsic mitochondrial pathway. Interestingly, overexpressed activated p53 specifically inhibits cell-growth and causes regression in vivo tumor growth as well. Conclusion Present study details the mechanism of activation of p53 and puts forth the possibility of p53 gene therapy to work in HPV positive cervical carcinoma.

Diclofenac inhibits tumor growth in a murine model of pancreatic cancer by modulation of VEGF levels and arginase activity.

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Mayorek, Nina; Naftali-Shani, Nili; Grunewald, Myriam

2010-09-15

Diclofenac is one of the oldest anti-inflammatory drugs in use. In addition to its inhibition of cyclooxygenases (COX), diclofenac potently inhibits phospholipase A(2) (PLA(2)), thus yielding a broad anti-inflammatory effect. Since inflammation is an important factor in the development of pancreatic tumors we explored the potential of diclofenac to inhibit tumor growth in mice inoculated with PANCO2 cells orthotopically. We found that diclofenac treatment (30 mg/kg/bw for 11 days) of mice inoculated with PANC02 cells, reduced the tumor weight by 60%, correlating with increased apoptosis of tumor cells. Since this effect was not observed in vitro on cultured PANCO2 cells, we theorized that diclofenac beneficial treatment involved other mediators present in vivo. Indeed, diclofenac drastically decreased tumor vascularization by downregulating VEGF in the tumor and in abdominal cavity fluid. Furthermore, diclofenac directly inhibited vascular sprouting ex vivo. Surprisingly, in contrast to other COX-2 inhibitors, diclofenac increased arginase activity/arginase 1 protein content in tumor stroma cells, peritoneal macrophages and white blood cells by 2.4, 4.8 and 2 fold, respectively. We propose that the subsequent arginine depletion and decrease in NO levels, both in serum and peritoneal cavity, adds to tumor growth inhibition by malnourishment and poor vasculature development. In conclusion, diclofenac shows pronounced antitumoral properties in pancreatic cancer model that can contribute to further treatment development. The ability of diclofenac to induce arginase activity in tumor stroma, peritoneal macrophages and white blood cells provides a tool to study a controversial issue of pro-and antitumoral effects of arginine depletion.

Tumor cells and memory T cells converge at glycolysis

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Karthikeyan, Swathi; Geschwind, Jean-Francois; Ganapathy-Kanniappan, Shanmugasundaram

2014-01-01

In the immune system, activation of naïve T (Tn) cells into effector T cells (Teff) involves a metabolic switch to glycolysis to promote rapid proliferation and differentiation. In the October issue of The Journal of Clinical Investigation, Sukumar et al. have demonstrated that in CD8+ memory T (Tems) cells glycolytic phenotype contributes to the shortened lifespan of Tems. Conversely, inhibition of glycolysis in Tems not only extended their viability but also augmented desirable properties. Notably, they also demonstrate that glycolytic inhibition during the ex vivo clonal expansion of tumor-specific Tems enhanced their antitumor function. Overall, the data suggest that an antiglycolytic strategy targeting the Tems could enhance antitumor immune response. On the other hand, cancer cells have long been known to exhibit metabolic reprogramming which involves a shift toward glycolysis (the conversion of glucose into lactate) to facilitate uninterrupted growth. Interestingly, antiglycolytic treatment of cancer cells has been known to trigger antitumor immune response as well. Taken together, it is probable that a strategy involving concurrent inhibition of glycolysis in tumor cells and Tems could promote a dual attack on cancer by inducing an effective antitumor immune response and an immunogenic chemotherapy. PMID:24556820

JNK inhibition sensitizes tumor cells to radiation-induced premature senescence via Bcl-2/ROS/DDR signaling pathway

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Lee, Jae Seon; Lee, Je Jung

2009-01-01

Premature senescence is considered as a cellular defense mechanism to prevent tumorigenesis. Although recent evidences demonstrate that c-Jun N-terminal kinase (JNK) is involved in the senescence process, the target and exact mechanism of JNK signaling in the regulation of cell proliferation has yet to be defined. In this study, we investigated the role of JNK in premature senescence and demonstrated JNK inhibition sensitized tumor cells to radiation-induced premature senescence

Specific Inhibition of the VEGFR-3 Tyrosine Kinase by SAR131675 Reduces Peripheral and Tumor Associated Immunosuppressive Myeloid Cells

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Espagnolle, Nicolas; Barron, Pauline; Mandron, Marie; Blanc, Isabelle; Bonnin, Jacques; Agnel, Magali; Kerbelec, Erwan; Herault, Jean Pascal; Savi, Pierre; Bono, Françoise; Alam, Antoine

2014-01-01

Myeloid derived suppressor cells (MDSCs) and tumor-associated macrophages (TAMs) represent prominent components in cancer progression. We previously showed that inhibition of the VEGFR-3 pathway by SAR131675 leads to reduction of TAM infiltration and tumor growth. Here, we found that treatment with SAR131675 prevents the accumulation of immunosuppressive blood and splenic MDSCs which express VEGFR-3, in 4T1 tumor bearing mice. Moreover we showed that soluble factors secreted by tumor cells promote MDSCs proliferation and differentiation into M2 polarized F4/80+ macrophages. In addition, cell sorting and transcriptomic analysis of tumor infiltrating myeloid cells revealed the presence of a heterogeneous population that could be divided into 3 subpopulations: (i) immature cells with a MDSC phenotype (GR1+/CD11b+/F4/80 − ); (ii) “immuno-incompetent” macrophages (F4/80 high /CD86 neg /MHCII Low ) strongly expressing M2 markers such as Legumain, CD206 and Mgl1/2 and (iii) “immuno-competent”-M1 like macrophages (F4/80 Low /CD86 + /MHCII High ). SAR131675 treatment reduced MDSCs in lymphoid organs as well as F4/80 High populations in tumors. Interestingly, in the tumor SAR131675 was able to increase the immunocompetent M1 like population (F4/80 low ). Altogether these results demonstrate that the specific VEGFR-3 inhibitor SAR131675 exerts its anti tumoral activity by acting on different players that orchestrate immunosuppression and cancer progression in a tumoral context: MDSCs in peripheral lymphoid organs and TAMs infiltrating the tumor

Human CD34+ cells engineered to express membrane-bound tumor necrosis factor-related apoptosis-inducing ligand target both tumor cells and tumor vasculature.

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Lavazza, Cristiana; Carlo-Stella, Carmelo; Giacomini, Arianna; Cleris, Loredana; Righi, Marco; Sia, Daniela; Di Nicola, Massimo; Magni, Michele; Longoni, Paolo; Milanesi, Marco; Francolini, Maura; Gloghini, Annunziata; Carbone, Antonino; Formelli, Franca; Gianni, Alessandro M

2010-03-18

Adenovirus-transduced CD34+ cells expressing membrane-bound tumor necrosis factor-related apoptosis-inducing ligand (CD34-TRAIL+ cells) exert potent antitumor activity. To further investigate the mechanism(s) of action of CD34-TRAIL+ cells, we analyzed their homing properties as well as antitumor and antivascular effects using a subcutaneous myeloma model in immunodeficient mice. After intravenous injection, transduced cells homed in the tumor peaking at 48 hours when 188 plus or minus 25 CD45+ cells per 10(5) tumor cells were detected. Inhibition experiments showed that tumor homing of CD34-TRAIL+ cells was largely mediated by vascular cell adhesion molecule-1 and stromal cell-derived factor-1. Both CD34-TRAIL+ cells and soluble (s)TRAIL significantly reduced tumor volume by 40% and 29%, respectively. Computer-aided analysis of TdT-mediated dUTP nick end-labeling-stained tumor sections demonstrated significantly greater effectiveness for CD34-TRAIL+ cells in increasing tumor cell apoptosis and necrosis over sTRAIL. Proteome array analysis indicated that CD34-TRAIL+ cells and sTRAIL activate similar apoptotic machinery. In vivo staining of tumor vasculature with sulfosuccinimidyl-6-(biotinamido) hexanoate-biotin revealed that CD34-TRAIL+ cells but not sTRAIL significantly damaged tumor vasculature, as shown by TdT-mediated dUTP nick end-labeling+ endothelial cells, appearance of hemorrhagic areas, and marked reduction of endothelial area. These results demonstrate that tumor homing of CD34-TRAIL+ cells induces early vascular disruption, resulting in hemorrhagic necrosis and tumor destruction.

Fungi & Health: can polysaccharides from the fungus inonotus obliquus (CHAGA) inhibit tumor growth?

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Wold, C. W.; Corthay, A.; Kjeldsen, Christian

Inonotus obliquus (Chaga) – a white rot fungus found on birch trees in the northern hemisphere –has been used in traditional medicine in Europe and Asia for centuries. Native peoples have made use of Chaga by brewing it as a tea to treat gastro-intestinal problems, to heal wounds and even to treat...... cancer. The last few decades, studies have found Chaga to contain biologically active substances such as polysaccharides, triterpenoids, polyphenols and melanin. In vivo effects such as tumor growth inhibition have been observed in mice receiving various Chaga extracts. The main hypothesis behind...... the tumor inhibiting effect is two-fold: i) fungal polysaccharides may inhibit tumor growth indirectly by activating certain immune cells such as macrophages and ii) triterpenoids and other steroids from Chaga may give a direct cytotoxic effect against cancer cells. While triterpenoids from Chaga have been...

Herbal Extract SH003 Suppresses Tumor Growth and Metastasis of MDA-MB-231 Breast Cancer Cells by Inhibiting STAT3-IL-6 Signaling

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Youn Kyung Choi

2014-01-01

Full Text Available Cancer inflammation promotes cancer progression, resulting in a high risk of cancer. Here, we demonstrate that our new herbal extract, SH003, suppresses both tumor growth and metastasis of MDA-MB-231 breast cancer cells via inhibiting STAT3-IL-6 signaling path. Our new herbal formula, SH003, mixed extract from Astragalus membranaceus, Angelica gigas, and Trichosanthes kirilowii Maximowicz, suppressed MDA-MB-231 tumor growth and lung metastasis in vivo and reduced the viability and metastatic abilities of MDA-MB-231 cells in vitro. Furthermore, SH003 inhibited STAT3 activation, which resulted in a reduction of IL-6 production. Therefore, we conclude that SH003 suppresses highly metastatic breast cancer growth and metastasis by inhibiting STAT3-IL-6 signaling path.

Exogenous HGF Bypasses the Effects of ErbB Inhibition on Tumor Cell Viability in Medulloblastoma Cell Lines.

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Walderik W Zomerman

Full Text Available Recent clinical trials investigating receptor tyrosine kinase (RTK inhibitors showed a limited clinical response in medulloblastoma. The present study investigated the role of micro-environmental growth factors expressed in the brain, such as HGF and EGF, in relation to the effects of hepatocyte growth factor receptor (MET and epidermal growth factor receptor family (ErbB1-4 inhibition in medulloblastoma cell lines. Medulloblastoma cell lines were treated with tyrosine kinase inhibitors crizotinib or canertinib, targeting MET and ErbB1-4, respectively. Upon treatment, cells were stimulated with VEGF-A, PDGF-AB, HGF, FGF-2 or EGF. Subsequently, we measured cell viability and expression levels of growth factors and downstream signaling proteins. Addition of HGF or EGF phosphorylated MET or EGFR, respectively, and demonstrated phosphorylation of Akt and ERK1/2 as well as increased tumor cell viability. Crizotinib and canertinib both inhibited cell viability and phosphorylation of Akt and ERK1/2. Specifically targeting MET using shRNA's resulted in decreased cell viability. Interestingly, addition of HGF to canertinib significantly enhanced cell viability as well as phosphorylation of Akt and ERK1/2. The HGF-induced bypass of canertinib was reversed by addition of crizotinib. HGF protein was hardly released by medulloblastoma cells itself. Addition of canertinib did not affect RTK cell surface or growth factor expression levels. This manuscript points to the bypassing capacity of exogenous HGF in medulloblastoma cell lines. It might be of great interest to anticipate on these results in developing novel clinical trials with a combination of MET and EGFR inhibitors in medulloblastoma.

Modeling Pharmacological Inhibition of Mast Cell Degranulation as a Therapy for Insulinoma

Directory of Open Access Journals (Sweden)

Laura Soucek

2011-11-01

Full Text Available Myc, a pleiotropic transcription factor that is deregulated and/or overexpressed in most human cancers, instructs multiple extracellular programs that are required to sustain the complex microenvironment needed for tumor maintenance, including remodeling of tumor stroma, angiogenesis, and inflammation. We previously showed in a model of pancreatic β-cell tumorigenesis that acute Myc activation in vivo triggers rapid recruitment of mast cells to the tumor site and that this is absolutely required for angiogenesis and macroscopic tumor expansion. More-over, systemic inhibition of mast cell degranulation with sodium cromoglycate induced death of tumor and endothelial cells in established tumors. Hence, mast cells are required both to establish and to maintain the tumors. Whereas this intimates that selective inhibition of mast cell function could be therapeutically efficacious, cromoglycate is not a practical drug for systemic delivery in humans, and no other systemic inhibitor of mast cell degranulation has hitherto been available. PCI-32765 is a novel inhibitor of Bruton tyrosine kinase (Btk that blocks mast cell degranulation and is currently in clinical trial as a therapy for B-cell non–Hodgkin lymphoma. Here, we show that systemic treatment of insulinoma-bearing mice with PCI-32765 efficiently inhibits Btk, blocks mast cell degranulation, and triggers collapse of tumor vasculature and tumor regression. These data reinforce the notion that mast cell function is required for maintenance of certain tumor types and indicate that the Btk inhibitor PCI-32765 may be useful in treating such diseases.

Optimization of dendritic cell loading with tumor cell lysates for cancer immunotherapy.

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Hatfield, Paul; Merrick, Alison E; West, Emma; O'Donnell, Dearbhaile; Selby, Peter; Vile, Richard; Melcher, Alan A

2008-09-01

The immune response to cancer is critically determined by the way in which tumor cells die. As necrotic, stress-associated death can be associated with activation of antitumor immunity, whole tumor cell antigen loading strategies for dendritic cell (DC)-based vaccination have commonly used freeze-thaw "necrotic" lysates as an immunogenic source of tumor-associated antigens. In this study, the effect of such lysates on the ability of DCs to mature in response to well-established maturation stimuli was examined, and methods to enhance lysate-induced DC activation explored. Freeze-thaw lysates were prepared from murine tumor cell lines and their effects on bone marrow-derived DC maturation and function examined. Unmodified freeze-thaw tumor cell lysates inhibited the toll-like receptor-induced maturation and function of bone marrow-derived DCs, preventing up-regulation of CD40, CD86, and major histocompatibility complex class II, and reducing secretion of inflammatory cytokines [interleukin (IL)-12 p70, tumor necrosis factor-alpha, and IL-6]. Although IL-10 secretion was increased by lysate-pulsed DCs, this was not responsible for the observed suppression of IL-12. Although activation of the nuclear factor-kappaB pathway remained intact, the kinase activity of phosphorylated p38 mitogen-activated protein kinase was inhibited in lysate-pulsed DCs. Lysate-induced DC suppression was partially reversed in vitro by induction of tumor cell stress before lysis, and only DCs loaded with stressed lysates afforded protection against tumor challenge in vivo. These data suggest that ex vivo freeze-thaw of tumor cells does not effectively mimic in vivo immunogenic necrosis, and advocates careful characterization and optimization of tumor cell-derived vaccine sources for cancer immunotherapy.

Diclofenac inhibits tumor growth in a murine model of pancreatic cancer by modulation of VEGF levels and arginase activity.

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Nina Mayorek

Full Text Available BACKGROUND: Diclofenac is one of the oldest anti-inflammatory drugs in use. In addition to its inhibition of cyclooxygenases (COX, diclofenac potently inhibits phospholipase A(2 (PLA(2, thus yielding a broad anti-inflammatory effect. Since inflammation is an important factor in the development of pancreatic tumors we explored the potential of diclofenac to inhibit tumor growth in mice inoculated with PANCO2 cells orthotopically. METHODOLOGY/PRINCIPAL FINDINGS: We found that diclofenac treatment (30 mg/kg/bw for 11 days of mice inoculated with PANC02 cells, reduced the tumor weight by 60%, correlating with increased apoptosis of tumor cells. Since this effect was not observed in vitro on cultured PANCO2 cells, we theorized that diclofenac beneficial treatment involved other mediators present in vivo. Indeed, diclofenac drastically decreased tumor vascularization by downregulating VEGF in the tumor and in abdominal cavity fluid. Furthermore, diclofenac directly inhibited vascular sprouting ex vivo. Surprisingly, in contrast to other COX-2 inhibitors, diclofenac increased arginase activity/arginase 1 protein content in tumor stroma cells, peritoneal macrophages and white blood cells by 2.4, 4.8 and 2 fold, respectively. We propose that the subsequent arginine depletion and decrease in NO levels, both in serum and peritoneal cavity, adds to tumor growth inhibition by malnourishment and poor vasculature development. CONCLUSION/SIGNIFICANCE: In conclusion, diclofenac shows pronounced antitumoral properties in pancreatic cancer model that can contribute to further treatment development. The ability of diclofenac to induce arginase activity in tumor stroma, peritoneal macrophages and white blood cells provides a tool to study a controversial issue of pro-and antitumoral effects of arginine depletion.

Regulation of hormone release by cultured cells from a thyrotropin-growth hormone-secreting pituitary tumor. Direct inhibiting effects of 3,5,3'-triiodothyronine and dexamethasone on thyrotropin secretion.

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Lamberts, S W; Oosterom, R; Verleun, T; Krenning, E P; Assies, H

1984-08-01

The regulation of TSH and GH secretion was investigated in cultured tumor cells prepared from a mixed TSH/GH secreting pituitary tumor. The tumor tissue had been removed transsphenoidally from a patient with hyperthyroidism and inappropriately high serum TSH levels and acromegaly. TSH and GH secretion by cultured cells were stimulated in a parallel way by TRH (300 nM) and LHRH (50 nM), but were unaffected by bromocriptine (10 nM). Exposure of the tumor cells to dexamethasone (0.1 microM) or T3 (50 nM) had differential effects on hormone secretion. GH secretion was greatly stimulated by dexamethasone, but unaffected by T3. TSH secretion was inhibited both by T3 and by dexamethasone. So, T3 and glucocorticoids inhibit TSH release by the human pituitary tumor cells studied at least partly by means of a direct effect.

Tumor-altered dendritic cell function: implications for anti-tumor immunity

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Kristian Michael Hargadon

2013-07-01

Full Text Available Dendritic cells are key regulators of both innate and adaptive immunity, and the array of immunoregulatory functions exhibited by these cells is dictated by their differentiation, maturation, and activation status. Although a major role for these cells in the induction of immunity to pathogens has long been appreciated, data accumulated over the last several years has demonstrated that DC are also critical regulators of anti-tumor immune responses. However, despite the potential for stimulation of robust anti-tumor immunity by DC, tumor-altered DC function has been observed in many cancer patients and tumor-bearing animals and is often associated with tumor immune escape. Such dysfunction has significant implications for both the induction of natural anti-tumor immune responses as well as the efficacy of immunotherapeutic strategies that target endogenous DC in situ or that employ exogenous DC as part of anti-cancer immunization maneuvers. In this review, the major types of tumor-altered DC function will be described, with emphasis on recent insights into the mechanistic bases for the inhibition of DC differentiation from hematopoietic precursors, the altered programming of DC precursors to differentiate into myeloid-derived suppressor cells or tumor-associated macrophages, the suppression of DC maturation and activation, and the induction of immunoregulatory DC by tumors, tumor-derived factors, and tumor-associated cells within the milieu of the tumor microenvironment. The impact of these tumor-altered cells on the quality of the overall anti-tumor immune response will also be discussed. Finally, this review will also highlight questions concerning tumor-altered DC function that remain unanswered, and it will address factors that have limited advances in the study of this phenomenon in order to focus future research efforts in the field on identifying strategies for interfering with tumor-associated DC dysfunction and improving DC-mediated anti-tumor

A conjugate of an anti-midkine single-chain variable fragment to doxorubicin inhibits tumor growth

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Zhao, Shuli [Immunology and Reproductive Biology Laboratory, Medical School & State Key Laboratory of Pharmaceutical Biotechnology, Nanjing University, Nanjing (China); Nanjing Affiliated First Hospital, Nanjing Medical University, Nanjing (China); Zhao, Guangfeng; Xie, Hao; Huang, Yahong [Immunology and Reproductive Biology Laboratory, Medical School & State Key Laboratory of Pharmaceutical Biotechnology, Nanjing University, Nanjing (China); Hou, Yayi [Immunology and Reproductive Biology Laboratory, Medical School & State Key Laboratory of Pharmaceutical Biotechnology, Nanjing University, Nanjing (China); Jiangsu Key Laboratory of Molecular Medicine, Nanjing University, Nanjing (China)

2012-01-27

Doxorubicin (DOX) was conjugated to a single-chain variable fragment (scFv) against human midkine (MK), and the conjugate (scFv-DOX) was used to target the chemotherapeutic agent to a mouse solid tumor model in which the tumor cells expressed high levels of human MK. The His-tagged recombinant scFv was expressed in bacteria, purified by metal affinity chromatography, and then conjugated to DOX using oxidative dextran (Dex) as a linker. The molecular formula of this immunoconjugate was scFv(Dex){sub 1.3}(DOX){sub 20}. In vitro apoptosis assays showed that the scFv-DOX conjugate was more cytotoxic against MK-transfected human adenocarcinoma cells (BGC823-MK) than untransfected cells (55.3 ± 2.4 vs 22.4 ± 3.8%) for three independent experiments. Nude mice bearing BGC823-MK solid tumors received scFv-DOX or equivalent doses of scFv + DOX for 2 weeks and tumor growth was more effectively inhibited by the scFv-DOX conjugate than by scFv + DOX (51.83% inhibition vs 40.81%). Histological analysis of the tumor tissues revealed that the highest levels of DOX accumulated in tumors from mice treated with scFv-DOX and this resulted in more extensive tumor cell death than in animals treated with the equivalent dose of scFv + DOX. These results show that the scFv-DOX conjugate effectively inhibited tumor growth in vivo and suggest that antigen-specific scFv may be competent drug-carriers.

A conjugate of an anti-midkine single-chain variable fragment to doxorubicin inhibits tumor growth

International Nuclear Information System (INIS)

Zhao, Shuli; Zhao, Guangfeng; Xie, Hao; Huang, Yahong; Hou, Yayi

2012-01-01

Doxorubicin (DOX) was conjugated to a single-chain variable fragment (scFv) against human midkine (MK), and the conjugate (scFv-DOX) was used to target the chemotherapeutic agent to a mouse solid tumor model in which the tumor cells expressed high levels of human MK. The His-tagged recombinant scFv was expressed in bacteria, purified by metal affinity chromatography, and then conjugated to DOX using oxidative dextran (Dex) as a linker. The molecular formula of this immunoconjugate was scFv(Dex) 1.3 (DOX) 20 . In vitro apoptosis assays showed that the scFv-DOX conjugate was more cytotoxic against MK-transfected human adenocarcinoma cells (BGC823-MK) than untransfected cells (55.3 ± 2.4 vs 22.4 ± 3.8%) for three independent experiments. Nude mice bearing BGC823-MK solid tumors received scFv-DOX or equivalent doses of scFv + DOX for 2 weeks and tumor growth was more effectively inhibited by the scFv-DOX conjugate than by scFv + DOX (51.83% inhibition vs 40.81%). Histological analysis of the tumor tissues revealed that the highest levels of DOX accumulated in tumors from mice treated with scFv-DOX and this resulted in more extensive tumor cell death than in animals treated with the equivalent dose of scFv + DOX. These results show that the scFv-DOX conjugate effectively inhibited tumor growth in vivo and suggest that antigen-specific scFv may be competent drug-carriers

Specific Inhibition of the VEGFR-3 Tyrosine Kinase by SAR131675 Reduces Peripheral and Tumor Associated Immunosuppressive Myeloid Cells

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Espagnolle, Nicolas [UMR5273 INSERM U1031/CNRS/EFS StromaLab, Toulouse 31432 (France); Barron, Pauline; Mandron, Marie; Blanc, Isabelle; Bonnin, Jacques [Sanofi Recherche et Développement, Early to Candidate DPU, Toulouse 31036 (France); Agnel, Magali; Kerbelec, Erwan [Molecular Biology Unit, Biologics Department, Sanofi, Vitry-sur-Seine 94400 (France); Herault, Jean Pascal; Savi, Pierre; Bono, Françoise; Alam, Antoine, E-mail: antoine.alam@sanofi.com [Sanofi Recherche et Développement, Early to Candidate DPU, Toulouse 31036 (France)

2014-02-28

Myeloid derived suppressor cells (MDSCs) and tumor-associated macrophages (TAMs) represent prominent components in cancer progression. We previously showed that inhibition of the VEGFR-3 pathway by SAR131675 leads to reduction of TAM infiltration and tumor growth. Here, we found that treatment with SAR131675 prevents the accumulation of immunosuppressive blood and splenic MDSCs which express VEGFR-3, in 4T1 tumor bearing mice. Moreover we showed that soluble factors secreted by tumor cells promote MDSCs proliferation and differentiation into M2 polarized F4/80+ macrophages. In addition, cell sorting and transcriptomic analysis of tumor infiltrating myeloid cells revealed the presence of a heterogeneous population that could be divided into 3 subpopulations: (i) immature cells with a MDSC phenotype (GR1+/CD11b+/F4/80{sup −}); (ii) “immuno-incompetent” macrophages (F4/80{sup high}/CD86{sup neg}/MHCII{sup Low}) strongly expressing M2 markers such as Legumain, CD206 and Mgl1/2 and (iii) “immuno-competent”-M1 like macrophages (F4/80{sup Low}/CD86{sup +}/MHCII{sup High}). SAR131675 treatment reduced MDSCs in lymphoid organs as well as F4/80{sup High} populations in tumors. Interestingly, in the tumor SAR131675 was able to increase the immunocompetent M1 like population (F4/80{sup low}). Altogether these results demonstrate that the specific VEGFR-3 inhibitor SAR131675 exerts its anti tumoral activity by acting on different players that orchestrate immunosuppression and cancer progression in a tumoral context: MDSCs in peripheral lymphoid organs and TAMs infiltrating the tumor.

HIF-1α inhibition blocks the cross talk between multiple myeloma plasma cells and tumor microenvironment

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Borsi, Enrica, E-mail: enrica.borsi2@unibo.it [Department of Experimental Diagnostic and Specialty Medicine (DIMES), “L. and A. Seràgnoli”, Bologna University School of Medicine, S. Orsola' s University Hospital (Italy); Perrone, Giulia [Fondazione IRCCS Istituto Nazionale dei Tumori, Hematology Department, Via Venezian 1, 20133 Milano (Italy); Terragna, Carolina; Martello, Marina; Zamagni, Elena; Tacchetti, Paola; Pantani, Lucia; Brioli, Annamaria; Dico, Angela Flores; Zannetti, Beatrice Anna; Rocchi, Serena; Cavo, Michele [Department of Experimental Diagnostic and Specialty Medicine (DIMES), “L. and A. Seràgnoli”, Bologna University School of Medicine, S. Orsola' s University Hospital (Italy)

2014-11-01

Multiple myeloma (MM) is a malignant disorder of post-germinal center B cells, characterized by the clonal proliferation of malignant plasma cells (PCs) within the bone marrow (BM). The reciprocal and complex interactions that take place between the different compartments of BM and the MM cells result in tumor growth, angiogenesis, bone disease, and drug resistance. Given the importance of the BM microenvironment in MM pathogenesis, we investigated the possible involvement of Hypoxia-Inducible transcription Factor-1 alpha (HIF-1α) in the PCs-bone marrow stromal cells interplay. To test this hypothesis, we used EZN-2968, a 3rd generation antisense oligonucleotide against HIF-1α, to inhibit HIF-1α functions. Herein, we provide evidence that the interaction between MM cells and BM stromal cells is drastically reduced upon HIF-1α down-modulation. Notably, we showed that upon exposure to HIF-1α inhibitor, neither the incubation with IL-6 nor the co-culture with BM stromal cells were able to revert the anti-proliferative effect induced by EZN-2968. Moreover, we observed a down-modulation of cytokine-induced signaling cascades and a reduction of MM cells adhesion capability to the extracellular matrix proteins in EZN-2968-treated samples. Taken together, these results strongly support the concept that HIF-1α plays a critical role in the interactions between bone BM cells and PCs in Multiple Myeloma. - Highlights: • HIF-1α inhibition induces a mild apoptotic cell death. • Down-modulation of cytokine-induced signaling cascades upon HIF-1α inhibition. • Reduced interaction between MM cells and BMSCs upon HIF-1α down-modulation. • Reduced PCs adhesion to the extracellular matrix protein induced by EZN-2968. • HIF-1α inhibition may be an attractive therapeutic strategy for Multiple Myeloma.

(+)-Nootkatone inhibits tumor necrosis factor α/interferon γ-induced production of chemokines in HaCaT cells

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Choi, Hyeon-Jae; Lee, Jin-Hwee [College of Pharmacy, Ajou University, Suwon 443-749 (Korea, Republic of); Jung, Yi-Sook, E-mail: yisjung@ajou.ac.kr [College of Pharmacy, Ajou University, Suwon 443-749 (Korea, Republic of); Research Institute of Pharmaceutical Sciences and Technology, Ajou University, Suwon 443-749 (Korea, Republic of)

2014-05-02

Highlights: • (+)-Nootkatone inhibits TNF-α/IFN-γ-induced TARC and MDC expression in HaCaT cells. • PKCζ, p38 MAPK, or NF-κB mediate TNF-α/IFN-γ-induced TARC and MDC expression. • (+)-Nootkatone inhibits TNF-α/IFN-γ-induced activation of PKCζ, p38 MAPK, or NF-κB. • (+)-Nootkatone suppresses chemokine expression by inhibiting of PKCζ and p38 pathways. - Abstract: Chemokines are important mediators of cell migration, and thymus and activation-regulated chemokine (TARC/CCL17) and macrophage-derived chemokine (MDC/CCL22) are well-known typical inflammatory chemokines involved in atopic dermatitis (AD). (+)-Nootkatone is the major component of Cyperus rotundus. (+)-Nootkatone has antiallergic, anti-inflammatory, and antiplatelet activities. The purpose of this study was to investigate the effect of (+)-nootkatone on tumor necrosis factor α (TNF-α)/interferon γ (IFN-γ)-induced expression of Th2 chemokines in HaCaT cells. We found that (+)-nootkatone inhibited the TNF-α/IFN-γ-induced expression of TARC/CCL17 and MDC/CCL22 mRNA in HaCaT cells. It also significantly inhibited TNF-α/IFN-γ-induced activation of nuclear factor kappa B (NF-κB), p38 mitogen-activated protein kinase (MAPK), and protein kinase Cζ (PKCζ). Furthermore, we showed that PKCζ and p38 MAPK contributed to the inhibition of TNF-α/IFN-γ-induced TARC/CCL17 and MDC/CCL22 expression by blocking IκBα degradation in HaCaT cells. Taken together, these results suggest that (+)-nootkatone may suppress TNF-α/IFN-γ-induced TARC/CCL17 and MDC/CCL22 expression in HaCaT cells by inhibiting of PKCζ and p38 MAPK signaling pathways that lead to activation of NF-κB. We propose that (+)-nootkatone may be a useful therapeutic candidate for inflammatory skin diseases such as AD.

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.

Inhibition of autophagy induced by proteasome inhibition increases cell death in human SHG-44 glioma cells.

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Ge, Peng-Fei; Zhang, Ji-Zhou; Wang, Xiao-Fei; Meng, Fan-Kai; Li, Wen-Chen; Luan, Yong-Xin; Ling, Feng; Luo, Yi-Nan

2009-07-01

The ubiquitin-proteasome system (UPS) and lysosome-dependent macroautophagy (autophagy) are two major intracellular pathways for protein degradation. Recent studies suggest that proteasome inhibitors may reduce tumor growth and activate autophagy. Due to the dual roles of autophagy in tumor cell survival and death, the effect of autophagy on the destiny of glioma cells remains unclear. In this study, we sought to investigate whether inhibition of the proteasome can induce autophagy and the effects of autophagy on the fate of human SHG-44 glioma cells. The proteasome inhibitor MG-132 was used to induce autophagy in SHG-44 glioma cells, and the effect of autophagy on the survival of SHG-44 glioma cells was investigated using an autophagy inhibitor 3-MA. Cell viability was measured by MTT assay. Apoptosis and cell cycle were detected by flow cytometry. The expression of autophagy related proteins was determined by Western blot. MG-132 inhibited cell proliferation, induced cell death and cell cycle arrest at G(2)/M phase, and activated autophagy in SHG-44 glioma cells. The expression of autophagy-related Beclin-1 and LC3-I was significantly up-regulated and part of LC3-I was converted into LC3-II. However, when SHG-44 glioma cells were co-treated with MG-132 and 3-MA, the cells became less viable, but cell death and cell numbers at G(2)/M phase increased. Moreover, the accumulation of acidic vesicular organelles was decreased, the expression of Beclin-1 and LC3 was significantly down-regulated and the conversion of LC3-II from LC3-I was also inhibited. Inhibition of the proteasome can induce autophagy in human SHG-44 glioma cells, and inhibition of autophagy increases cell death. This discovery may shed new light on the effect of autophagy on modulating the fate of SHG-44 glioma cells.Acta Pharmacologica Sinica (2009) 30: 1046-1052; doi: 10.1038/aps.2009.71.

Cell Cycle Regulating Kinase Cdk4 as a Potential Target for Tumor Cell Treatment and Tumor Imaging

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Franziska Graf

2009-01-01

Full Text Available The cyclin-dependent kinase (Cdk-cyclin D/retinoblastoma (pRb/E2F cascade, which controls the G1/S transition of cell cycle, has been found to be altered in many neoplasias. Inhibition of this pathway by using, for example, selective Cdk4 inhibitors has been suggested to be a promising approach for cancer therapy. We hypothesized that appropriately radiolabeled Cdk4 inhibitors are suitable probes for tumor imaging and may be helpful studying cell proliferation processes in vivo by positron emission tomography. Herein, we report the synthesis and biological, biochemical, and radiopharmacological characterizations of two I124-labeled small molecule Cdk4 inhibitors (8-cyclopentyl-6-iodo-5-methyl-2-(4-piperazin-1-yl-phenylamino-8H-pyrido[2,3-d]-pyrimidin-7-one (CKIA and 8-cyclopentyl-6-iodo-5-methyl-2-(5-(piperazin-1-yl-pyridin-2-yl-amino-8H-pyrido[2,3-d]pyrimidin-7-one (CKIB. Our data demonstrate a defined and specific inhibition of tumor cell proliferation through CKIA and CKIB by inhibition of the Cdk4/pRb/E2F pathway emphasizing potential therapeutic benefit of CKIA and CKIB. Furthermore, radiopharmacological properties of [I124]CKIA and [I124]CKIB observed in human tumor cells are promising prerequisites for in vivo biodistribution and imaging studies.

Kaempferol inhibits cell proliferation and glycolysis in esophagus squamous cell carcinoma via targeting EGFR signaling pathway.

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Yao, Shihua; Wang, Xiaowei; Li, Chunguang; Zhao, Tiejun; Jin, Hai; Fang, Wentao

2016-08-01

Antitumor activity of kaempferol has been studied in various tumor types, but its potency in esophagus squamous cell carcinoma is rarely known. Here, we reported the activity of kaempferol against esophagus squamous cell carcinoma as well as its antitumor mechanisms. Results of cell proliferation and colony formation assay showed that kaempferol substantially inhibited tumor cell proliferation and clone formation in vitro. Flow cytometric analysis demonstrated that tumor cells were induced G0/G1 phase arrest after kaempferol treatment, and the expression of protein involved in cell cycle regulation was dramatically changed. Except the potency on cell proliferation, we also discovered that kaempferol had a significant inhibitory effect against tumor glycolysis. With the downregulation of hexokinase-2, glucose uptake and lactate production in tumor cells were dramatically declined. Mechanism studies revealed kaempferol had a direct effect on epidermal growth factor receptor (EGFR) activity, and along with the inhibition of EGFR, its downstream signaling pathways were also markedly suppressed. Further investigations found that exogenous overexpression of EGFR in tumor cells substantially attenuated glycolysis suppression induced by kaempferol, which implied that EGFR also played an important role in kaempferol-mediated glycolysis inhibition. Finally, the antitumor activity of kaempferol was validated in xenograft model and kaempferol prominently restrained tumor growth in vivo. Meanwhile, dramatic decrease of EGFR activity and hexokinase-2 expression were observed in kaempferol-treated tumor tissue, which confirmed these findings in vitro. Briefly, these studies suggested that kaempferol, or its analogues, may serve as effective candidates for esophagus squamous cell carcinoma management.

EGCG Inhibits Proliferation, Invasiveness and Tumor Growth by Up-Regulation of Adhesion Molecules, Suppression of Gelatinases Activity, and Induction of Apoptosis in Nasopharyngeal Carcinoma Cells

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Chih-Yeu Fang

2015-01-01

Full Text Available (−-Epigallocatechin-3-gallate (EGCG, a major green tea polyphenol, has been shown to inhibit the proliferation of a variety of tumor cells. Epidemiological studies have shown that drinking green tea can reduce the incidence of nasopharyngeal carcinoma (NPC, yet the underlying mechanism is not well understood. In this study, the inhibitory effect of EGCG was tested on a set of Epstein Barr virus-negative and -positive NPC cell lines. Treatment with EGCG inhibited the proliferation of NPC cells but did not affect the growth of a non-malignant nasopharyngeal cell line, NP460hTert. Moreover, EGCG treated cells had reduced migration and invasive properties. The expression of the cell adhesion molecules E-cadherin and β-catenin was found to be up-regulated by EGCG treatment, while the down-regulation of matrix metalloproteinases (MMP-2 and MMP-9 were found to be mediated by suppression of extracellular signal-regulated kinase (ERK phosphorylation and AP-1 and Sp1 transactivation. Spheroid formation by NPC cells in suspension was significantly inhibited by EGCG. Oral administration of EGCG was capable of suppressing tumor growth in xenografted mice bearing NPC tumors. Treatment with EGCG was found to elevate the expression of p53 and p21, and eventually led to apoptosis of NPC cells via caspase 3 activation. The nuclear translocation of NF-κB and β-catenin was also suppressed by EGCG treatment. These results indicate that EGCG can inhibit the proliferation and invasiveness, and induce apoptosis, of NPC cells, making it a promising agent for chemoprevention or adjuvant therapy of NPC.

AKT-mediated enhanced aerobic glycolysis causes acquired radioresistance by human tumor cells

International Nuclear Information System (INIS)

Shimura, Tsutomu; Noma, Naoto; Sano, Yui; Ochiai, Yasushi; Oikawa, Toshiyuki; Fukumoto, Manabu; Kunugita, Naoki

2014-01-01

Background and purpose: Cellular radioresistance is a major impediment to effective radiotherapy. Here, we demonstrated that long-term exposure to fractionated radiation conferred acquired radioresistance to tumor cells due to AKT-mediated enhanced aerobic glycolysis. Material and methods: Two human tumor cell lines with acquired radioresistance were established by long-term exposure to fractionated radiation with 0.5 Gy of X-rays. Glucose uptake was inhibited using 2-deoxy-D-glucose, a non-metabolizable glucose analog. Aerobic glycolysis was assessed by measuring lactate concentrations. Cells were then used for assays of ROS generation, survival, and cell death as assessed by annexin V staining. Results: Enhanced aerobic glycolysis was shown by increased glucose transporter Glut1 expression and a high lactate production rate in acquired radioresistant cells compared with parental cells. Inhibiting the AKT pathway using the AKT inhibitor API-2 abrogated these phenomena. Moreover, we found that inhibiting glycolysis with 2-deoxy-D-glucose suppressed acquired tumor cell radioresistance. Conclusions: Long-term fractionated radiation confers acquired radioresistance to tumor cells by AKT-mediated alterations in their glucose metabolic pathway. Thus, tumor cell metabolic pathway is an attractive target to eliminate radioresistant cells and improve radiotherapy efficacy

Polo-like kinase 1 (PLK1) inhibition suppresses cell growth and enhances radiation sensitivity in medulloblastoma cells

International Nuclear Information System (INIS)

Harris, Peter S; Foreman, Nicholas K; Vibhakar, Rajeev; Venkataraman, Sujatha; Alimova, Irina; Birks, Diane K; Donson, Andrew M; Knipstein, Jeffrey; Dubuc, Adrian; Taylor, Michael D; Handler, Michael H

2012-01-01

Medulloblastoma is the most common malignant brain tumor in children and remains a therapeutic challenge due to its significant therapy-related morbidity. Polo-like kinase 1 (PLK1) is highly expressed in many cancers and regulates critical steps in mitotic progression. Recent studies suggest that targeting PLK1 with small molecule inhibitors is a promising approach to tumor therapy. We examined the expression of PLK1 mRNA in medulloblastoma tumor samples using microarray analysis. The impact of PLK1 on cell proliferation was evaluated by depleting expression with RNA interference (RNAi) or by inhibiting function with the small molecule inhibitor BI 2536. Colony formation studies were performed to examine the impact of BI 2536 on medulloblastoma cell radiosensitivity. In addition, the impact of depleting PLK1 mRNA on tumor-initiating cells was evaluated using tumor sphere assays. Analysis of gene expression in two independent cohorts revealed that PLK1 mRNA is overexpressed in some, but not all, medulloblastoma patient samples when compared to normal cerebellum. Inhibition of PLK1 by RNAi significantly decreased medulloblastoma cell proliferation and clonogenic potential and increased cell apoptosis. Similarly, a low nanomolar concentration of BI 2536, a small molecule inhibitor of PLK1, potently inhibited cell growth, strongly suppressed the colony-forming ability, and increased cellular apoptosis of medulloblastoma cells. Furthermore, BI 2536 pretreatment sensitized medulloblastoma cells to ionizing radiation. Inhibition of PLK1 impaired tumor sphere formation of medulloblastoma cells and decreased the expression of SRY (sex determining region Y)-box 2 (SOX2) mRNA in tumor spheres indicating a possible role in targeting tumor inititiating cells. Our data suggest that targeting PLK1 with small molecule inhibitors, in combination with radiation therapy, is a novel strategy in the treatment of medulloblastoma that warrants further investigation

Berberine enhances inhibition of glioma tumor cell migration and invasiveness mediated by arsenic trioxide

International Nuclear Information System (INIS)

Lin, Tseng-Hsi; Kuo, Hsing-Chun; Chou, Fen-Pi; Lu, Fung-Jou

2008-01-01

Arsenic trioxide (As 2 O 3 ) exhibits promising anticarcinogenic activity in acute promyelocytic leukemic patients and induces apoptosis in various tumor cells in vitro. Here, we investigated the effect of the natural alkaloid berberine on As 2 O 3 -mediated inhibition of cancer cell migration using rat and human glioma cell lines. The 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) assay was used to determine the viability of rat C6 and human U-87 glioma cells after treatment with As 2 O 3 or berberine, and after co-treatment with As 2 O 3 and berberine. The wound scratch and Boyden chamber assays were applied to determine the effect of As 2 O 3 and berberine on the migration capacity and invasiveness of glioma cancer cells. Zymography and Western blot analyses provided information on the effect of As 2 O 3 and berberine on the intracellular translocation and activation of protein kinase C (PKC), and some PKC-related downstream factors. Most assays were performed three times, independently, and data were analyzed using ANOVA. The cell viability studies demonstrated that berberine enhances As 2 O 3 -mediated inhibition of glioma cell growth after 24 h incubation. Untreated control cells formed a confluent layer, the formation of which was inhibited upon incubation with 5 μM As 2 O 3 . The latter effect was even more pronounced in the presence of 10 μM berberine. The As 2 O 3 -mediated reduction in motility and invasion of glioma cells was enhanced upon co-treatment with berberine. Furthermore, it has been reported that PKC isoforms influence the morphology of the actin cytoskeleton, as well as the activation of metalloproteases MT1-MMP and MMP-2, reported to be involved in cancer cell migration. Treatment of glioma cells with As 2 O 3 and berberine significantly decreased the activation of PKC α and ε and led to actin cytoskeleton rearrangements. The levels of two downstream transcription factors, myc and jun, and MT1-MMP and MMP-2 were also

Pharmacological inhibition of radiation induced in vitro tumor cell/endothelium cell interactions and in vivo metastasis processes; Pharmakologische Hemmung strahleninduzierter Tumorzell-Endothelzell-Interaktionen in vitro und Metastasierungsprozesse in vivo

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Herzog, Melanie

2013-05-07

Exposure of endothelial cells with ionizing radiation (IR) or treatment with inflammatory cytokines (e. g. TNFα) induces a Rho-GTPase and NF-κB dependent activation of the expression of various cell adhesion molecules, including E-selectin. E-selectin mediates the adhesion of tumor cells (TC) to endothelial cells and is probably involved in the extravasation step of circulating tumor cells. HMG-CoA reductase inhibitors (e. g. lovastatin) inhibit the function of Rho-GTPases and thus are anticipated to attenuate Rho-regulated cell-cell-adhesion as well. This study focuses on the influence of IR and TNFα on the expression of endothelial- and/or tumor cell-specific pro-adhesive factors and whether these effects are influenced by lovastatin. To this end, the effect of IR and TNFα on cell-cell-interactions between human colon carcinoma cells (HT29) and human umbilical vein endothelial cells (HUVEC) was investigated using an ELISA-based cell adhesion-assay. Moreover, the influence of pre-treatment with lovastatin and other types of inhibitors on HUVEC-HT29 adhesion was monitored. Additionally, we investigated the effect of lovastatin on mRNA expression level of different cell adhesion molecules, metastatic factors and DNA-repair genes upon radiation exposure by qRT-PCR. To scrutinize the in vivo relevance of the data obtained, we investigated the effect of total body irradiation (TBI) on the mRNA expression of pro-adhesive factors in BALB/c mice. To analyze tumor cell extravasation, tumor cells were injected into the lateral tail vein of immundeficient mice, followed by total body irradiation (TBI, 4 Gy). After four weeks a large increase of lung metastases was monitored, which could be blocked by preatreatment of the mice with lovastatin, the Rac1-specific small-molecule inhibitor NSC23766 as well as the sLe{sup x}-mimetic glycyrrhizin. Summarizing, we provide evidence, that irradiation promotes upregulation of different cell adhesion molecules in vitro and

Non-cell autonomous or secretory tumor suppression.

Science.gov (United States)

Chua, Christelle En Lin; Chan, Shu Ning; Tang, Bor Luen

2014-10-01

Many malignancies result from deletions or loss-of-function mutations in one or more tumor suppressor genes, the products of which curb unrestrained growth or induce cell death in those with dysregulated proliferative capacities. Most tumor suppressors act in a cell autonomous manner, and only very few proteins are shown to exert a non-cell autonomous tumor suppressor function on other cells. Examples of these include members of the secreted frizzled-related protein (SFRP) family and the secreted protein acidic and rich in cysteine (SPARC)-related proteins. Very recent findings have, however, considerably expanded our appreciation of non-cell autonomous tumor suppressor functions. Broadly, this may occur in two ways. Intracellular tumor suppressor proteins within cells could in principle inhibit aberrant growth of neighboring cells by conditioning an antitumor microenvironment through secreted factors. This is demonstrated by an apparent non-cell autonomous tumor suppressing property of p53. On the other hand, a tumor suppressor produced by a cell may be secreted extracellularly, and taken up by another cell with its activity intact. Intriguingly, this has been recently shown to occur for the phosphatase and tensin homolog (PTEN) by both conventional and unconventional modes of secretion. These recent findings would aid the development of therapeutic strategies that seek to reinstate tumor suppression activity in therapeutically recalcitrant tumor cells, which have lost it in the first place. © 2014 Wiley Periodicals, Inc.

In vivo overexpression of tumstatin domains by tumor cells inhibits their invasive properties in a mouse melanoma model

International Nuclear Information System (INIS)

Pasco, Sylvie; Ramont, Laurent; Venteo, Lydie; Pluot, Michel; Maquart, Francois-Xavier; Monboisse, Jean-Claude

2004-01-01

Our previous studies demonstrated that a synthetic peptide encompassing residues 185-203 of the noncollagenous (NC1) domain of the α3 chain of type IV collagen, named tumstatin, inhibits in vitro melanoma cell proliferation and migration. In the present study, B16F1 melanoma cells were stably transfected to overexpress the complete tumstatin domain (Tum 1-232) or its C-terminal part, encompassing residues 185-203 (Tum 183-232). Tumstatin domain overexpression inhibited B16F1 in vitro cell proliferation, anchorage-independent growth, and invasive properties. For studying the in vivo effect of overexpression, representative clones were subcutaneously injected into the left side of C57BL6 mice. In vivo tumor growth was decreased by -60% and -56%, respectively, with B16F1 cells overexpressing Tum 1-232 or Tum 183-232 compared to control cells. This inhibitory effect was associated with a decrease of in vivo cyclin D1 expression. We also demonstrated that the overexpression of Tum 1-232 or Tum 183-232 induced an in vivo down-regulation of proteolytic cascades involving matrix metalloproteinases (MMPs), especially the production or activation of MMP-2, MMP-9, MMP-13, as well as MMP-14. The plasminogen activation system was also altered in tumors with a decrease of urokinase-type plasminogen activator (u-PA) and tissue-type plasminogen activator (t-PA) and a strong increase of plasminogen activator inhibitor-1 (PAI-1). Collectively, our results demonstrate that tumstatin or its C-terminal antitumor fragment, Tum 183-232, inhibits in vivo melanoma progression by triggering an intracellular transduction pathway, which involves a cyclic AMP (cAMP)-dependent mechanism

Impact of adjuvant inhibition of vascular endothelial growth factor receptor tyrosine kinases on tumor growth delay and local tumor control after fractionated irradiation in human squamous cell carcinomas in nude mice

International Nuclear Information System (INIS)

Zips, Daniel; Hessel, Franziska; Krause, Mechthild; Schiefer, Yvonne; Hoinkis, Cordelia; Thames, Howard D.; Haberey, Martin; Baumann, Michael

2005-01-01

Purpose: Previous experiments have shown that adjuvant inhibition of the vascular endothelial growth factor receptor after fractionated irradiation prolonged tumor growth delay and may also improve local tumor control. To test the latter hypothesis, local tumor control experiments were performed. Methods and materials: Human FaDu and UT-SCC-14 squamous cell carcinomas were studied in nude mice. The vascular endothelial growth factor receptor tyrosine kinase inhibitor PTK787/ZK222584 (50 mg/kg body weight b.i.d.) was administered for 75 days after irradiation with 30 fractions within 6 weeks. Tumor growth time and tumor control dose 50% (TCD 50 ) were determined and compared to controls (carrier without PTK787/ZK222584). Results: Adjuvant administration of PTK787/ZK222584 significantly prolonged tumor growth time to reach 5 times the volume at start of drug treatment by an average of 11 days (95% confidence interval 0.06;22) in FaDu tumors and 29 days (0.6;58) in UT-SCC-14 tumors. In both tumor models, TCD 50 values were not statistically significantly different between the groups treated with PTK787/ZK222584 compared to controls. Conclusions: Long-term inhibition of angiogenesis after radiotherapy significantly reduced the growth rate of local recurrences but did not improve local tumor control. This indicates that recurrences after irradiation depend on vascular endothelial growth factor-driven angiogenesis, but surviving tumor cells retain their clonogenic potential during adjuvant antiangiogenic treatment with PTK787/ZK222584

Inhibition of brain tumor cell proliferation by alternating electric fields

International Nuclear Information System (INIS)

Jeong, Hyesun; Oh, Seung-ick; Hong, Sunghoi; Sung, Jiwon; Jeong, Seonghoon; Yoon, Myonggeun; Koh, Eui Kwan

2014-01-01

This study was designed to investigate the mechanism by which electric fields affect cell function, and to determine the optimal conditions for electric field inhibition of cancer cell proliferation. Low-intensity (<2 V/cm) and intermediate-frequency (100–300 kHz) alternating electric fields were applied to glioblastoma cell lines. These electric fields inhibited cell proliferation by inducing cell cycle arrest and abnormal mitosis due to the malformation of microtubules. These effects were significantly dependent on the intensity and frequency of applied electric fields

Inhibition of brain tumor cell proliferation by alternating electric fields

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Jeong, Hyesun; Oh, Seung-ick; Hong, Sunghoi, E-mail: shong21@korea.ac.kr, E-mail: radioyoon@korea.ac.kr [School of Biosystem and Biomedical Science, Korea University, Seoul 136-703 (Korea, Republic of); Sung, Jiwon; Jeong, Seonghoon; Yoon, Myonggeun, E-mail: shong21@korea.ac.kr, E-mail: radioyoon@korea.ac.kr [Department of Bio-convergence Engineering, Korea University, Seoul 136-703 (Korea, Republic of); Koh, Eui Kwan [Seoul Center, Korea Basic Science Institute, Seoul 136-713 (Korea, Republic of)

2014-11-17

This study was designed to investigate the mechanism by which electric fields affect cell function, and to determine the optimal conditions for electric field inhibition of cancer cell proliferation. Low-intensity (<2 V/cm) and intermediate-frequency (100–300 kHz) alternating electric fields were applied to glioblastoma cell lines. These electric fields inhibited cell proliferation by inducing cell cycle arrest and abnormal mitosis due to the malformation of microtubules. These effects were significantly dependent on the intensity and frequency of applied electric fields.

Inhibition of Cell Survival by Curcumin Is Associated with Downregulation of Cell Division Cycle 20 (Cdc20) in Pancreatic Cancer Cells.

Science.gov (United States)

Zhang, Yu; Xue, Ying-Bo; Li, Hang; Qiu, Dong; Wang, Zhi-Wei; Tan, Shi-Sheng

2017-02-04

Pancreatic cancer is one of the most aggressive human tumors in the United States. Curcumin, a polyphenol derived from the Curcuma longa plant, has been reported to exert its antitumor activity in pancreatic cancer. However, the molecular mechanisms of curcumin-mediated tumor suppressive function have not been fully elucidated. In the current study, we explore whether curcumin exhibits its anti-cancer function through inhibition of oncoprotein cell division cycle 20 (Cdc20) in pancreatic cancer cells. We found that curcumin inhibited cell growth, enhanced apoptosis, induced cell cycle arrest and retarded cell invasion in pancreatic cancer cells. Moreover, we observed that curcumin significantly inhibited the expression of Cdc20 in pancreatic cancer cells. Furthermore, our results demonstrated that overexpression of Cdc20 enhanced cell proliferation and invasion, and abrogated the cytotoxic effects induced by curcumin in pancreatic cancer cells. Consistently, downregulation of Cdc20 promoted curcumin-mediated anti-tumor activity. Therefore, our findings indicated that inhibition of Cdc20 by curcumin could be useful for the treatment of pancreatic cancer patients.

Human adipose tissue-derived mesenchymal stem cells inhibit T-cell lymphoma growth in vitro and in vivo.

Science.gov (United States)

Ahn, Jin-Ok; Chae, Ji-Sang; Coh, Ye-Rin; Jung, Woo-Sung; Lee, Hee-Woo; Shin, Il-Seob; Kang, Sung-Keun; Youn, Hwa-Young

2014-09-01

Human mesenchymal stem cells (hMSCs) are thought to be one of the most reliable stem cell sources for a variety of cell therapies. This study investigated the anti-tumor effect of human adipose tissue-derived mesenchymal stem cells (hAT-MSCs) on EL4 murine T-cell lymphoma in vitro and in vivo. The growth-inhibitory effect of hAT-MSCs on EL4 tumor cells was evaluated using a WST-1 cell proliferation assay. Cell-cycle arrest and apoptosis were investigated by flow cytometry and western blot. To evaluate an anti-tumor effect of hAT-MSCs on T-cell lymphoma in vivo, CM-DiI-labeled hAT-MSCs were circumtumorally injected in tumor-bearing nude mice, and tumor size was measured. hAT-MSCs inhibited T-cell lymphoma growth by altering cell-cycle progression and inducing apoptosis in vitro. hAT-MSCs inhibited tumor growth in tumor-bearing nude mice and prolonged survival time. Immunofluorescence analysis showed that hAT-MSCs migrated to tumor sites. hAT-MSCs suppress the growth of T-cell lymphoma, suggesting a therapeutic option for T-cell lymphoma. Copyright© 2014 International Institute of Anticancer Research (Dr. John G. Delinassios), All rights reserved.

Inhibition of hepatocyte gap junctional intercellular communication by tumor promoters

International Nuclear Information System (INIS)

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

Inhibition of cyclic AMP response element-directed transcription by decoy oligonucleotides enhances tumor-specific radiosensitivity

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Park, Serk In, E-mail: serkin@korea.edu [Department of Biochemistry and Molecular Biology, Korea University College of Medicine, Seoul (Korea, Republic of); The BK21 Plus Program for Biomedical Sciences, Korea University College of Medicine, Seoul (Korea, Republic of); Department of Medicine and Center for Bone Biology, Vanderbilt University School of Medicine, Nashville, TN (United States); Park, Sung-Jun [Department of Biochemistry and Molecular Biology, Korea University College of Medicine, Seoul (Korea, Republic of); Laboratory of Obesity and Aging Research, National Heart, Lung and Blood Institute, National Institutes of Health, Bethesda, MD (United States); Lee, Junghan; Kim, Hye Eun; Park, Su Jin; Sohn, Jeong-Won [Department of Biochemistry and Molecular Biology, Korea University College of Medicine, Seoul (Korea, Republic of); Park, Yun Gyu, E-mail: parkyg@korea.ac.kr [Department of Biochemistry and Molecular Biology, Korea University College of Medicine, Seoul (Korea, Republic of)

2016-01-15

The radiation stress induces cytotoxic responses of cell death as well as cytoprotective responses of cell survival. Understanding exact cellular mechanism and signal transduction pathways is important in improving cancer radiotherapy. Increasing evidence suggests that cyclic AMP response element binding protein (CREB)/activating transcription factor (ATF) family proteins act as a survival factor and a signaling molecule in response to stress. We postulated that CREB inhibition via CRE decoy oligonucleotide increases tumor cell sensitization to γ-irradiation-induced cytotoxic stress. In the present study, we demonstrate that CREB phosphorylation and CREB DNA-protein complex formation increased in time- and radiation dose-dependent manners, while there was no significant change in total protein level of CREB. In addition, CREB was phosphorylated in response to γ-irradiation through p38 MAPK pathway. Further investigation revealed that CREB blockade by decoy oligonucleotides functionally inhibited transactivation of CREB, and significantly increased radiosensitivity of multiple human cancer cell lines including TP53- and/or RB-mutated cells with minimal effects on normal cells. We also demonstrate that tumor cells ectopically expressing dominant negative mutant CREB (KCREB) and the cells treated with p38 MAPK inhibitors were more sensitive to γ-irradiation than wild type parental cells or control-treated cells. Taken together, we conclude that CREB protects tumor cells from γ-irradiation, and combination of CREB inhibition plus ionizing radiation will be a promising radiotherapeutic approach. - Highlights: • γ-Irradiation induced CREB phosphorylation and CRE-directed transcription in tumor. • γ-Irradiation-induced transcriptional activation of CREB was via p38 MAPK pathway. • CRE blockade increased radiosensitivity of tumor cells but not of normal cells. • CRE decoy oligonucleotides or p38 MAPK inhibitors can be used as radiosensitizers.

Inhibition of cyclic AMP response element-directed transcription by decoy oligonucleotides enhances tumor-specific radiosensitivity

International Nuclear Information System (INIS)

Park, Serk In; Park, Sung-Jun; Lee, Junghan; Kim, Hye Eun; Park, Su Jin; Sohn, Jeong-Won; Park, Yun Gyu

2016-01-01

The radiation stress induces cytotoxic responses of cell death as well as cytoprotective responses of cell survival. Understanding exact cellular mechanism and signal transduction pathways is important in improving cancer radiotherapy. Increasing evidence suggests that cyclic AMP response element binding protein (CREB)/activating transcription factor (ATF) family proteins act as a survival factor and a signaling molecule in response to stress. We postulated that CREB inhibition via CRE decoy oligonucleotide increases tumor cell sensitization to γ-irradiation-induced cytotoxic stress. In the present study, we demonstrate that CREB phosphorylation and CREB DNA-protein complex formation increased in time- and radiation dose-dependent manners, while there was no significant change in total protein level of CREB. In addition, CREB was phosphorylated in response to γ-irradiation through p38 MAPK pathway. Further investigation revealed that CREB blockade by decoy oligonucleotides functionally inhibited transactivation of CREB, and significantly increased radiosensitivity of multiple human cancer cell lines including TP53- and/or RB-mutated cells with minimal effects on normal cells. We also demonstrate that tumor cells ectopically expressing dominant negative mutant CREB (KCREB) and the cells treated with p38 MAPK inhibitors were more sensitive to γ-irradiation than wild type parental cells or control-treated cells. Taken together, we conclude that CREB protects tumor cells from γ-irradiation, and combination of CREB inhibition plus ionizing radiation will be a promising radiotherapeutic approach. - Highlights: • γ-Irradiation induced CREB phosphorylation and CRE-directed transcription in tumor. • γ-Irradiation-induced transcriptional activation of CREB was via p38 MAPK pathway. • CRE blockade increased radiosensitivity of tumor cells but not of normal cells. • CRE decoy oligonucleotides or p38 MAPK inhibitors can be used as radiosensitizers.

EGFR overexpressing cells and tumors are dependent on autophagy for growth and survival

International Nuclear Information System (INIS)

Jutten, Barry; Keulers, Tom G.; Schaaf, Marco B.E.; Savelkouls, Kim; Theys, Jan; Span, Paul N.; Vooijs, Marc A.; Bussink, Johan; Rouschop, Kasper M.A.

2013-01-01

Background and purpose: The epidermal growth factor receptor (EGFR) is overexpressed, amplified or mutated in various human epithelial tumors, and is associated with tumor aggressiveness and therapy resistance. Autophagy activation provides a survival advantage for cells in the tumor microenvironment. In the current study, we assessed the potential of autophagy inhibition (using chloroquine (CQ)) in treatment of EGFR expressing tumors. Material and methods: Quantitative PCR, immunohistochemistry, clonogenic survival, proliferation assays and in vivo tumor growth were used to assess this potential. Results: We show that EGFR overexpressing xenografts are sensitive to CQ treatment and are sensitized to irradiation by autophagy inhibition. In HNSSC xenografts, a correlation between EGFR and expression of the autophagy marker LC3b is observed, suggesting a role for autophagy in EGFR expressing tumors. This observation was substantiated in cell lines, showing high EGFR expressing cells to be more sensitive to CQ addition as reflected by decreased proliferation and survival. Surprisingly high EGFR expressing cells display a lower autophagic flux. Conclusions: The EGFR high expressing cells and tumors investigated in this study are highly dependent on autophagy for growth and survival. Inhibition of autophagy may therefore provide a novel treatment opportunity for EGFR overexpressing tumors

Targeting Myeloid-Derived Suppressor Cells to Bypass Tumor-Induced Immunosuppression

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Viktor Fleming

2018-03-01

Full Text Available The immune system has many sophisticated mechanisms to balance an extensive immune response. Distinct immunosuppressive cells could protect from excessive tissue damage and autoimmune disorders. Tumor cells take an advantage of those immunosuppressive mechanisms and establish a strongly immunosuppressive tumor microenvironment (TME, which inhibits antitumor immune responses, supporting the disease progression. Myeloid-derived suppressor cells (MDSC play a crucial role in this immunosuppressive TME. Those cells represent a heterogeneous population of immature myeloid cells with a strong immunosuppressive potential. They inhibit an antitumor reactivity of T cells and NK cells. Furthermore, they promote angiogenesis, establish pre-metastatic niches, and recruit other immunosuppressive cells such as regulatory T cells. Accumulating evidences demonstrated that the enrichment and activation of MDSC correlated with tumor progression, recurrence, and negative clinical outcome. In the last few years, various preclinical studies and clinical trials targeting MDSC showed promising results. In this review, we discuss different therapeutic approaches on MDSC targeting to overcome immunosuppressive TME and enhance the efficiency of current tumor immunotherapies.

Oridonin inhibits tumor growth and metastasis through anti-angiogenesis by blocking the Notch signaling.

Directory of Open Access Journals (Sweden)

Yanmin Dong

Full Text Available While significant progress has been made in understanding the anti-inflammatory and anti-proliferative effects of the natural diterpenoid component Oridonin on tumor cells, little is known about its effect on tumor angiogenesis or metastasis and on the underlying molecular mechanisms. In this study, Oridonin significantly suppressed human umbilical vascular endothelial cells (HUVECs proliferation, migration, and apillary-like structure formation in vitro. Using aortic ring assay and mouse corneal angiogenesis model, we found that Oridonin inhibited angiogenesis ex vivo and in vivo. In our animal experiments, Oridonin impeded tumor growth and metastasis. Immunohistochemistry analysis further revealed that the expression of CD31 and vWF protein in xenografts was remarkably decreased by the Oridonin. Furthermore, Oridonin reinforced endothelial cell-cell junction and impaired breast cancer cell transendothelial migration. Mechanistically, Oridonin not only down-regulated Jagged2 expression and Notch1 activity but also decreased the expression of their target genes. In conclusion, our results demonstrated an original role of Oridonin in inhibiting tumor angiogenesis and propose a mechanism. This study also provides new evidence supporting the central role of Notch in tumor angiogenesis and suggests that Oridonin could be a potential drug candidate for angiogenesis related diseases.

Antitumor Cell-Complex Vaccines Employing Genetically Modified Tumor Cells and Fibroblasts

Directory of Open Access Journals (Sweden)

Antonio Miguel

2014-02-01

Full Text Available The present study evaluates the immune response mediated by vaccination with cell complexes composed of irradiated B16 tumor cells and mouse fibroblasts genetically modified to produce GM-CSF. The animals were vaccinated with free B16 cells or cell complexes. We employed two gene plasmid constructions: one high producer (pMok and a low producer (p2F. Tumor transplant was performed by injection of B16 tumor cells. Plasma levels of total IgG and its subtypes were measured by ELISA. Tumor volumes were measured and survival curves were obtained. The study resulted in a cell complex vaccine able to stimulate the immune system to produce specific anti-tumor membrane proteins (TMP IgG. In the groups vaccinated with cells transfected with the low producer plasmid, IgG production was higher when we used free B16 cell rather than cell complexes. Nonspecific autoimmune response caused by cell complex was not greater than that induced by the tumor cells alone. Groups vaccinated with B16 transfected with low producer plasmid reached a tumor growth delay of 92% (p ≤ 0.01. When vaccinated with cell complex, the best group was that transfected with high producer plasmid, reaching a tumor growth inhibition of 56% (p ≤ 0.05. Significant survival (40% was only observed in the groups vaccinated with free transfected B16 cells.

Sodium orthovanadate associated with pharmacological doses of ascorbate causes an increased generation of ROS in tumor cells that inhibits proliferation and triggers apoptosis

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Günther, T-hat nia Mara Fischer; Kviecinski, Maicon Roberto; Baron, Carla Cristine; Felipe, Karina Bettega; Farias, Mirelle Sifroni; Ourique da Silva, Fabiana; Bücker, Nádia Cristina Falcão [Departamento de Bioquímica, Universidade Federal de Santa Catarina, Florianópolis (Brazil); Pich, Claus Tröger [Campus de Araranguá, Universidade Federal de Santa Catarina, Araranguá (Brazil); Ferreira, Eduardo Antonio [Universidade de Brasília, Faculdade de Ceilândia, DF (Brazil); Filho, Danilo Wilhelm [Departamento de Ecologia e Zoologia, Universidade Federal de Santa Catarina, Florianópolis (Brazil); Verrax, Julien; Calderon, Pedro Buc [Toxicology and Cancer Biology Research Group, Louvain Drug Research Institute, Université Catholique de Louvain, Brussels (Belgium); Pedrosa, Rozangela Curi, E-mail: rozangelapedrosa@gmail.com [Departamento de Bioquímica, Universidade Federal de Santa Catarina, Florianópolis (Brazil)

2013-01-18

Graphical abstract: -- Abstract: Pharmacological doses of ascorbate were evaluated for its ability to potentiate the toxicity of sodium orthovanadate (Na{sub 3}VO{sub 4}) in tumor cells. Cytotoxicity, inhibition of cell proliferation, generation of ROS and DNA fragmentation were assessed in T24 cells. Na{sub 3}VO{sub 4} was cytotoxic against T24 cells (EC{sub 50} = 5.8 μM at 24 h), but in the presence of ascorbate (100 μM) the EC{sub 50} fell to 3.3 μM. Na{sub 3}VO{sub 4} plus ascorbate caused a strong inhibition of cell proliferation (up to 20%) and increased the generation of ROS (4-fold). Na{sub 3}VO{sub 4} did not directly cleave plasmid DNA, at this aspect no synergism was found occurring between Na{sub 3}VO{sub 4} and ascorbate once the resulting action of the combination was no greater than that of both substances administered separately. Cells from Ehrlich ascites carcinoma-bearing mice were used to determine the activity of antioxidant enzymes, the extent of the oxidative damage and the type of cell death. Na{sub 3}VO{sub 4} alone, or combined with ascorbate, increased catalase activity, but only Na{sub 3}VO{sub 4} plus ascorbate increased superoxide dismutase activity (up to 4-fold). Oxidative damage on proteins and lipids was higher due to the treatment done with Na{sub 3}VO{sub 4} plus ascorbate (2–3-fold). Ascorbate potentiated apoptosis in tumor cells from mice treated with Na{sub 3}VO{sub 4}. The results indicate that pharmacological doses of ascorbate enhance the generation of ROS induced by Na{sub 3}VO{sub 4} in tumor cells causing inhibition of proliferation and apoptosis. Apoptosis induced by orthovanadate and ascorbate is closer related to inhibition on Bcl-xL and activation of Bax. Our data apparently rule out a mechanism of cell demise p53-dependent or related to Cdk2 impairment.

Anti-tumor activities of luteolin and silibinin in glioblastoma cells: overexpression of miR-7-1-3p augmented luteolin and silibinin to inhibit autophagy and induce apoptosis in glioblastoma in vivo.

Science.gov (United States)

Chakrabarti, Mrinmay; Ray, Swapan K

2016-03-01

Glioblastoma is the deadliest brain tumor in humans. High systemic toxicity of conventional chemotherapies prompted the search for natural compounds for controlling glioblastoma. The natural flavonoids luteolin (LUT) and silibinin (SIL) have anti-tumor activities. LUT inhibits autophagy, cell proliferation, metastasis, and angiogenesis and induces apoptosis; while SIL activates caspase-8 cascades to induce apoptosis. However, synergistic anti-tumor effects of LUT and SIL in glioblastoma remain unknown. Overexpression of tumor suppressor microRNA (miR) could enhance the anti-tumor effects of LUT and SIL. Here, we showed that 20 µM LUT and 50 µM SIL worked synergistically for inhibiting growth of two different human glioblastoma U87MG (wild-type p53) and T98G (mutant p53) cell lines and natural combination therapy was more effective than conventional chemotherapy (10 µM BCNU or 100 µM TMZ). Combination of LUT and SIL caused inhibition of growth of glioblastoma cells due to induction of significant amounts of apoptosis and complete inhibition of invasion and migration. Further, combination of LUT and SIL inhibited rapamycin (RAPA)-induced autophagy, a survival mechanism, with suppression of PKCα and promotion of apoptosis through down regulation of iNOS and significant increase in expression of the tumor suppressor miR-7-1-3p in glioblastoma cells. Our in vivo studies confirmed that overexpression of miR-7-1-3p augmented anti-tumor activities of LUT and SIL in RAPA pre-treated both U87MG and T98G tumors. In conclusion, our results clearly demonstrated that overexpression of miR-7-1-3p augmented the anti-tumor activities of LUT and SIL to inhibit autophagy and induce apoptosis for controlling growth of different human glioblastomas in vivo.

Hedgehog Pathway Inhibition Radiosensitizes Non-Small Cell Lung Cancers

Energy Technology Data Exchange (ETDEWEB)

Zeng, Jing; Aziz, Khaled; Chettiar, Sivarajan T. [Department of Radiation Oncology and Molecular Radiation Sciences, The Johns Hopkins University School of Medicine, Baltimore, Maryland (United States); Aftab, Blake T. [Department of Medical Oncology, The Johns Hopkins University School of Medicine, Baltimore, Maryland (United States); Armour, Michael; Gajula, Rajendra; Gandhi, Nishant; Salih, Tarek; Herman, Joseph M.; Wong, John [Department of Radiation Oncology and Molecular Radiation Sciences, The Johns Hopkins University School of Medicine, Baltimore, Maryland (United States); Rudin, Charles M. [Department of Medical Oncology, The Johns Hopkins University School of Medicine, Baltimore, Maryland (United States); Tran, Phuoc T. [Department of Radiation Oncology and Molecular Radiation Sciences, The Johns Hopkins University School of Medicine, Baltimore, Maryland (United States); Department of Medical Oncology, The Johns Hopkins University School of Medicine, Baltimore, Maryland (United States); Hales, Russell K., E-mail: rhales1@jhmi.edu [Department of Radiation Oncology and Molecular Radiation Sciences, The Johns Hopkins University School of Medicine, Baltimore, Maryland (United States)

2013-05-01

Purpose: Despite improvements in chemoradiation, local control remains a major clinical problem in locally advanced non-small cell lung cancer. The Hedgehog pathway has been implicated in tumor recurrence by promoting survival of tumorigenic precursors and through effects on tumor-associated stroma. Whether Hedgehog inhibition can affect radiation efficacy in vivo has not been reported. Methods and Materials: We evaluated the effects of a targeted Hedgehog inhibitor (HhAntag) and radiation on clonogenic survival of human non-small cell lung cancer lines in vitro. Using an A549 cell line xenograft model, we examined tumor growth, proliferation, apoptosis, and gene expression changes after concomitant HhAntag and radiation. In a transgenic mouse model of Kras{sup G12D}-induced and Twist1-induced lung adenocarcinoma, we assessed tumor response to radiation and HhAntag by serial micro-computed tomography (CT) scanning. Results: In 4 human lung cancer lines in vitro, HhAntag showed little or no effect on radiosensitivity. By contrast, in both the human tumor xenograft and murine inducible transgenic models, HhAntag enhanced radiation efficacy and delayed tumor growth. By use of the human xenograft model to differentiate tumor and stromal effects, mouse stromal cells, but not human tumor cells, showed significant and consistent downregulation of Hedgehog pathway gene expression. This was associated with increased tumor cell apoptosis. Conclusions: Targeted Hedgehog pathway inhibition can increase in vivo radiation efficacy in lung cancer preclinical models. This effect is associated with pathway suppression in tumor-associated stroma. These data support clinical testing of Hedgehog inhibitors as a component of multimodality therapy for locally advanced non-small cell lung cancer.

Antitumor action of 3-bromopyruvate implicates reorganized tumor growth regulatory components of tumor milieu, cell cycle arrest and induction of mitochondria-dependent tumor cell death.

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Yadav, Saveg; Kujur, Praveen Kumar; Pandey, Shrish Kumar; Goel, Yugal; Maurya, Babu Nandan; Verma, Ashish; Kumar, Ajay; Singh, Rana Pratap; Singh, Sukh Mahendra

2018-01-15

Evidences demonstrate that metabolic inhibitor 3-bromopyruvate (3-BP) exerts a potent antitumor action against a wide range of malignancies. However, the effect of 3-BP on progression of the tumors of thymic origin remains unexplored. Although, constituents of tumor microenvironment (TME) plays a pivotal role in regulation of tumor progression, it remains unclear if 3-BP can alter the composition of the crucial tumor growth regulatory components of the external surrounding of tumor cells. Thus, the present investigation attempts to understand the effect of 3-BP administration to a host bearing a progressively growing tumor of thymic origin on tumor growth regulatory soluble, cellular and biophysical components of tumor milieu vis-à-vis understanding its association with tumor progression, accompanying cell cycle events and mode of cell death. Further, the expression of cell survival regulatory molecules and hemodynamic characteristics of the tumor milieu were analysed to decipher mechanisms underlying the antitumor action of 3-BP. Administration of 3-BP to tumor-bearing hosts retarded tumor progression accompanied by induction of tumor cell death, cell cycle arrest, declined metabolism, inhibited mitochondrial membrane potential, elevated release of cytochrome c and altered hemodynamics. Moreover, 3-BP reconstituted the external milieu, in concurrence with deregulated glucose and pH homeostasis and increased tumor infiltration by NK cells, macrophages, and T lymphocytes. Further, 3-BP administration altered the expression of key regulatory molecules involved in glucose uptake, intracellular pH and tumor cell survival. The outcomes of this study will help in optimizing the therapeutic application of 3-BP by targeting crucial tumor growth regulatory components of tumor milieu. Copyright © 2017 Elsevier Inc. All rights reserved.

X-ray sensitivity of human tumor cells in vitro

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Weichselbaum, R.R.; Nove, J.; Little, J.B.

1980-01-01

Clonally-derived cells from ten human malignant tumors considered radiocurable (breast, neuroblastoma, medulloblastoma) or non-radiocurable (osteosarcoma, hypernephroma, glioblastoma, melanoma) were studied in cell culture and their in vitro x-ray survival curve parameters determined (anti n, D 0 ). There were no significant differences among the tumor cell lines suggesting that survival parameters in vitro do not explain differences in clinical radiocurability. Preliminary investigation with density inhibited human tumor cells indicate that such an approach may yield information regarding inherent cellular differences in radiocurability

Inhibition of GLO1 in Glioblastoma Multiforme Increases DNA-AGEs, Stimulates RAGE Expression, and Inhibits Brain Tumor Growth in Orthotopic Mouse Models

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Rahul Jandial

2018-01-01

Full Text Available Cancers that exhibit the Warburg effect may elevate expression of glyoxylase 1 (GLO1 to detoxify the toxic glycolytic byproduct methylglyoxal (MG and inhibit the formation of pro-apoptotic advanced glycation endproducts (AGEs. Inhibition of GLO1 in cancers that up-regulate glycolysis has been proposed as a therapeutic targeting strategy, but this approach has not been evaluated for glioblastoma multiforme (GBM, the most aggressive and difficult to treat malignancy of the brain. Elevated GLO1 expression in GBM was established in patient tumors and cell lines using bioinformatics tools and biochemical approaches. GLO1 inhibition in GBM cell lines and in an orthotopic xenograft GBM mouse model was examined using both small molecule and short hairpin RNA (shRNA approaches. Inhibition of GLO1 with S-(p-bromobenzyl glutathione dicyclopentyl ester (p-BrBzGSH(Cp2 increased levels of the DNA-AGE N2-1-(carboxyethyl-2′-deoxyguanosine (CEdG, a surrogate biomarker for nuclear MG exposure; substantially elevated expression of the immunoglobulin-like receptor for AGEs (RAGE; and induced apoptosis in GBM cell lines. Targeting GLO1 with shRNA similarly increased CEdG levels and RAGE expression, and was cytotoxic to glioma cells. Mice bearing orthotopic GBM xenografts treated systemically with p-BrBzGSH(Cp2 exhibited tumor regression without significant off-target effects suggesting that GLO1 inhibition may have value in the therapeutic management of these drug-resistant tumors.

Inhibition of GLO1 in Glioblastoma Multiforme Increases DNA-AGEs, Stimulates RAGE Expression, and Inhibits Brain Tumor Growth in Orthotopic Mouse Models.

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Jandial, Rahul; Neman, Josh; Lim, Punnajit P; Tamae, Daniel; Kowolik, Claudia M; Wuenschell, Gerald E; Shuck, Sarah C; Ciminera, Alexandra K; De Jesus, Luis R; Ouyang, Ching; Chen, Mike Y; Termini, John

2018-01-30

Cancers that exhibit the Warburg effect may elevate expression of glyoxylase 1 (GLO1) to detoxify the toxic glycolytic byproduct methylglyoxal (MG) and inhibit the formation of pro-apoptotic advanced glycation endproducts (AGEs). Inhibition of GLO1 in cancers that up-regulate glycolysis has been proposed as a therapeutic targeting strategy, but this approach has not been evaluated for glioblastoma multiforme (GBM), the most aggressive and difficult to treat malignancy of the brain. Elevated GLO1 expression in GBM was established in patient tumors and cell lines using bioinformatics tools and biochemical approaches. GLO1 inhibition in GBM cell lines and in an orthotopic xenograft GBM mouse model was examined using both small molecule and short hairpin RNA (shRNA) approaches. Inhibition of GLO1 with S -( p -bromobenzyl) glutathione dicyclopentyl ester ( p- BrBzGSH(Cp)₂) increased levels of the DNA-AGE N ²-1-(carboxyethyl)-2'-deoxyguanosine (CEdG), a surrogate biomarker for nuclear MG exposure; substantially elevated expression of the immunoglobulin-like receptor for AGEs (RAGE); and induced apoptosis in GBM cell lines. Targeting GLO1 with shRNA similarly increased CEdG levels and RAGE expression, and was cytotoxic to glioma cells. Mice bearing orthotopic GBM xenografts treated systemically with p -BrBzGSH(Cp)₂ exhibited tumor regression without significant off-target effects suggesting that GLO1 inhibition may have value in the therapeutic management of these drug-resistant tumors.

Tumor cells and memory T cells converge at glycolysis: therapeutic implications.

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Karthikeyan, Swathi; Geschwind, Jean-Francois; Ganapathy-Kanniappan, Shanmugasundaram

2014-05-01

In the immune system, activation of naïve T (Tn) cells into effector T cells (Teff) involves a metabolic switch to glycolysis to promote rapid proliferation and differentiation. In the October issue of The Journal of Clinical Investigation, Sukumar et al. have demonstrated that in CD8(+) memory T (Tems) cells glycolytic phenotype contributes to the shortened lifespan of Tems. Conversely, inhibition of glycolysis in Tems not only extended their viability but also augmented desirable properties. Notably, they also demonstrate that glycolytic inhibition during the ex vivo clonal expansion of tumor-specific Tems enhanced their antitumor function. Overall, the data suggest that an antiglycolytic strategy targeting the Tems could enhance antitumor immune response. On the other hand, cancer cells have long been known to exhibit metabolic reprogramming which involves a shift toward glycolysis (the conversion of glucose into lactate) to facilitate uninterrupted growth. Interestingly, antiglycolytic treatment of cancer cells has been known to trigger antitumor immune response as well. Taken together, it is probable that a strategy involving concurrent inhibition of glycolysis in tumor cells and Tems could promote a dual attack on cancer by inducing an effective antitumor immune response and an immunogenic chemotherapy.

Combination of interferon-alpha and 5-fluorouracil inhibits endothelial cell growth directly and by regulation of angiogenic factors released by tumor cells

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Wada, Hiroshi; Tanemura, Masahiro; Umeshita, Koji; Doki, Yuichiro; Mori, Masaki; Nagano, Hiroaki; Yamamoto, Hirofumi; Noda, Takehiro; Murakami, Masahiro; Kobayashi, Shogo; Marubashi, Shigeru; Eguchi, Hidetoshi; Takeda, Yutaka

2009-01-01

The combination therapy of interferon (IFN)-alpha and 5-fluorouracil (5-FU) improved the prognosis of the patients with hepatocellular carcinoma (HCC). To determine the molecular mechanisms of the anti-tumor and anti-angiogenic effects, we examined the direct anti-proliferative effects on human umbilical vein endothelial cells (HUVEC) and indirect effects by regulating secretion of angiogenic factors from HCC cells. The direct effects on HUVEC were examined by TUNEL, Annexin-V assays and cell cycles analysis. For analysis of the indirect effects, the apoptosis induced by the conditioned medium from HCC cell treated by IFN-alpha/5-FU and expression of angiogenic factors was examined. IFN-alpha and 5-FU alone had anti-proliferative properties on HUVEC and their combination significantly inhibited the growth (compared with control, 5-FU or IFN alone). TUNEL and Annexin-V assays showed no apoptosis. Cell cycle analysis revealed that IFN-alpha and 5-FU delayed cell cycle progression in HUVEC with S-phase accumulation. The conditioned medium from HuH-7 cells after treatment with IFN/5-FU significantly inhibited HUVEC growth and induced apoptosis, and contained high levels of angiopoietin (Ang)-1 and low levels of vascular endothelial growth factor (VEGF) and Ang-2. Knockdown of Ang-1 in HuH-7 cells abrogated the anti-proliferative effects on HUVEC while knockdown of Ang-2 partially rescue the cells. These results suggested that IFN-alpha and 5-FU had direct growth inhibitory effects on endothelial cells, as well as anti-angiogenic effects through regulation of angiogenic factors released from HCC cells. Modulation of VEGF and Angs secretion by IFN-alpha and 5-FU may contribute to their anti-angiogenic and anti-tumor effects on HCC

Genetically engineered endostatin-lidamycin fusion proteins effectively inhibit tumor growth and metastasis

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Jiang, Wen-guo; Zhen, Yong-su; Lu, Xin-an; Shang, Bo-yang; Fu, Yan; Zhang, Sheng-hua; Zhou, Daifu; Li, Liang; Li, Yi; Luo, Yongzhang

2013-01-01

Endostatin (ES) inhibits endothelial cell proliferation, migration, invasion, and tube formation. It also shows antiangiogenesis and antitumor activities in several animal models. Endostatin specifically targets tumor vasculature to block tumor growth. Lidamycin (LDM), which consists of an active enediyne chromophore (AE) and a non-covalently bound apo-protein (LDP), is a member of chromoprotein family of antitumor antibiotics with extremely potent cytotoxicity to cancer cells. Therefore, we reasoned that endostatin-lidamycin (ES-LDM) fusion proteins upon energizing with enediyne chromophore may obtain the combined capability targeting tumor vasculature and tumor cell by respective ES and LDM moiety. In this study, we designed and obtained two new endostatin-based fusion proteins, endostatin-LDP (ES-LDP) and LDP-endostatin (LDP-ES). In vitro, the antiangiogenic effect of fusion proteins was determined by the wound healing assay and tube formation assay and the cytotoxicity of their enediyne-energized analogs was evaluated by CCK-8 assay. Tissue microarray was used to analyze the binding affinity of LDP, ES or ES-LDP with specimens of human lung tissue and lung tumor. The in vivo efficacy of the fusion proteins was evaluated with human lung carcinoma PG-BE1 xenograft and the experimental metastasis model of 4T1-luc breast cancer. ES-LDP and LDP-ES disrupted the formation of endothelial tube structures and inhibited endothelial cell migration. Evidently, ES-LDP accumulated in the tumor and suppressed tumor growth and metastasis. ES-LDP and ES show higher binding capability than LDP to lung carcinoma; in addition, ES-LDP and ES share similar binding capability. Furthermore, the enediyne-energized fusion protein ES-LDP-AE demonstrated significant efficacy against lung carcinoma xenograft in athymic mice. The ES-based fusion protein therapy provides some fundamental information for further drug development. Targeting both tumor vasculature and tumor cells by endostatin

Inhibition of Tumor Growth of Human Hepatocellular Carcinoma HepG2 Cells in a Nude Mouse Xenograft Model by the Total Flavonoids from Arachniodes exilis

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Huimin Li

2017-01-01

Full Text Available A tumor growth model of human hepatocellular carcinoma HepG2 cells in nude mice was employed to investigate the antitumor activity of the total flavonoids extracted from Arachniodes exilis (TFAE in vivo. Several biochemical assays including hematoxylin-eosin (HE staining, immunohistochemistry, and Western blot were performed to elucidate the mechanism of action of total flavonoids extracted from Arachniodes exilis (TFAE. The results showed that TFAE effectively inhibited the tumor growth of hepatocellular carcinoma in nude mice and had no significant effect on body weight, blood system, and functions of liver and kidney. Expression levels of proapoptotic proteins Bax and cleaved caspase-3 remarkably increased while the expressions of Bcl-2, HIF-1α, and VEGF were suppressed by TFAE. These results suggested that the antitumor potential of TFEA was implied by the apoptosis of tumor cells and the inhibition of angiogenesis in tumor tissue.

Down-regulation of connective tissue growth factor by inhibition of transforming growth factor beta blocks the tumor-stroma cross-talk and tumor progression in hepatocellular carcinoma.

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Mazzocca, Antonio; Fransvea, Emilia; Dituri, Francesco; Lupo, Luigi; Antonaci, Salvatore; Giannelli, Gianluigi

2010-02-01

Tumor-stroma interactions in hepatocellular carcinoma (HCC) are of key importance to tumor progression. In this study, we show that HCC invasive cells produce high levels of connective tissue growth factor (CTGF) and generate tumors with a high stromal component in a xenograft model. A transforming growth factor beta (TGF-beta) receptor inhibitor, LY2109761, inhibited the synthesis and release of CTGF, as well as reducing the stromal component of the tumors. In addition, the TGF-beta-dependent down-regulation of CTGF diminished tumor growth, intravasation, and metastatic dissemination of HCC cells by inhibiting cancer-associated fibroblast proliferation. By contrast, noninvasive HCC cells were found to produce low levels of CTGF. Upon TGF-beta1 stimulation, noninvasive HCC cells form tumors with a high stromal content and CTGF expression, which is inhibited by treatment with LY2109761. In addition, the acquired intravasation and metastatic spread of noninvasive HCC cells after TGF-beta1 stimulation was blocked by LY2109761. LY2109761 interrupts the cross-talk between cancer cells and cancer-associated fibroblasts, leading to a significant reduction of HCC growth and dissemination. Interestingly, patients with high CTGF expression had poor prognosis, suggesting that treatment aimed at reducing TGF-beta-dependent CTGF expression may offer clinical benefits. Taken together, our preclinical results indicate that LY2109761 targets the cross-talk between HCC and the stroma and provide a rationale for future clinical trials.

Autophagy inhibition synergistically enhances anti-cancer efficacy of RAMBA, VN/12-1 in SKBR-3 cells and tumor xenografts

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Godbole, Abhijit M.; Purushottamachar, Puranik; Martin, Marlena S.; Daskalakis, Constantine; Njar, Vincent C. O.

2012-01-01

VN/12-1 is a novel retinoic acid metabolism blocking agent (RAMBA) discovered in our laboratory. The purpose of the study was to elucidate the molecular mechanism of VN/12-1’s anticancer activity in breast cancer cell lines and in tumor xenografts. We investigated the effects of VN/12-1 on induction of autophagy andapoptosis in SKBR-3 cells. Further, we also examined the impact of pharmacological and genomic inhibition of autophagy on VN/12-1’s anti-cancer activity. Finally, the anti-tumor activity of VN/12-1 was evaluated as a single agent and in combination with autophagy inhibitor chloroquine (CHL) in an SKBR-3 mouse xenograft model. Short exposure of low dose (< 10 µM) of VN/12-1 induced endoplasmic reticulum stress (ERS), autophagy and inhibits G1-S phase transition and caused a protective response. However, higher dose of VN/12-1 initiates apoptosis in vitro. Inhibition of autophagy using either pharmacological inhibitors or RNA interference of Beclin-1 enhanced anti-cancer activity induced by VN/12-1 in SKBR-3 cells by triggering apoptosis. Importantly, VN/12-1 (5 mg/kg twice weekly) and the combination of VN/12-1 (5 mg/kg twice weekly) + chloroquine (50 mg/kg twice weekly) significantly suppressed established SKBR-3 tumor growth by 81.4% (p < 0.001 vs. control) and 96.2% (p < 0.001 vs. control), respectively. Our novel findings suggest that VN/12-1 may be useful as a single agent or in combination with autophagy inhibitors for treating human breast cancers. Our data provides a strong rationale for clinical evaluation of VN/12-1 as single agent or in combination with autophagy inhibitors. PMID:22334589

Apoptosis and tumor cell death in response to HAMLET (human alpha-lactalbumin made lethal to tumor cells).

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Hallgren, Oskar; Aits, Sonja; Brest, Patrick; Gustafsson, Lotta; Mossberg, Ann-Kristin; Wullt, Björn; Svanborg, Catharina

2008-01-01

HAMLET (human alpha-lactalbumin made lethal to tumor cells) is a molecular complex derived from human milk that kills tumor cells by a process resembling programmed cell death. The complex consists of partially unfolded alpha-lactalbumin and oleic acid, and both the protein and the fatty acid are required for cell death. HAMLET has broad antitumor activity in vitro, and its therapeutic effect has been confirmed in vivo in a human glioblastoma rat xenograft model, in patients with skin papillomas and in patients with bladder cancer. The mechanisms of tumor cell death remain unclear, however. Immediately after the encounter with tumor cells, HAMLET invades the cells and causes mitochondrial membrane depolarization, cytochrome c release, phosphatidyl serine exposure, and a low caspase response. A fraction of the cells undergoes morphological changes characteristic of apoptosis, but caspase inhibition does not rescue the cells and Bcl-2 overexpression or altered p53 status does not influence the sensitivity of tumor cells to HAMLET. HAMLET also creates a state of unfolded protein overload and activates 20S proteasomes, which contributes to cell death. In parallel, HAMLET translocates to tumor cell nuclei, where high-affinity interactions with histones cause chromatin disruption, loss of transcription, and nuclear condensation. The dying cells also show morphological changes compatible with macroautophagy, and recent studies indicate that macroautophagy is involved in the cell death response to HAMLET. The results suggest that HAMLET, like a hydra with many heads, may interact with several crucial cellular organelles, thereby activating several forms of cell death, in parallel. This complexity might underlie the rapid death response of tumor cells and the broad antitumor activity of HAMLET.

Sodium Phenylbutyrate Inhibits Tumor Growth and the Epithelial-Mesenchymal Transition of Oral Squamous Cell Carcinoma In Vitro and In Vivo.

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Qian, Kun; Sun, Laiyu; Zhou, Guoqing; Ge, Haixia; Meng, Yue; Li, Jingfen; Li, Xiao; Fang, Xinqiang

2018-05-01

Sodium phenylbutyrate (SPB) as a salt of 4-phenylbutyric acid (4-PBA) has been reported to be an ammonia scavenger, histone deacetylase inhibitor, and an endoplasmic reticulum stress inhibitor in various diseases, including neurological diseases, inflammatory disorders, and carcinogenesis. Although phenylbutyrate showed effective antitumor properties in many cancers, its role in oral squamous cell carcinoma (OSCC) remains further characterized. Thus, the OSCC cell lines CAL27, HSC3, and SCC4 were treated with a series of doses of SPB for different times. The IC 50 of three cell lines for SPB was determined to be 4.0, 3.7, and 3.0 mM. The CCK-8 assay indicated that the treatment of SPB induced continuous inhibition of cell vitality of three cell lines. Apoptosis was assessed by Hoechst assay that showed that SPB could significantly promote cell apoptosis. Moreover, the apoptosis-related pathway was analyzed, and the results showed that the expression of antiapoptosis factor BCL-2 was downregulated by SPB but the cleavage of caspase-3 was increased. Meanwhile, it was found that SPB also impaired the migration and invasion of OSCC cells in vitro. Mechanistically, the transforming growth factor-β (TGFB) related epithelial-mesenchymal transition (EMT) was inhibited by SPB with decreased mesenchymal marker N-cadherin and increased epithelial marker E-cadherin. Furthermore, the antitumor effect of SPB in vivo was also demonstrated. The administration of SPB induced remarkably tumor regression with decreased tumor volume, and the TGFB level and EMT phenotype in vivo were also inhibited. These data demonstrated that the treatment of SPB could function as antitumor therapeutics for OSCC.

Tumor endothelial marker 5 expression in endothelial cells during capillary morphogenesis is induced by the small GTPase Rac and mediates contact inhibition of cell proliferation

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Vallon, Mario, E-mail: m.vallon@arcor.de [Nuklearmedizinische Klinik und Poliklinik, Technische Universitaet Muenchen, Ismaninger Strasse 22, 81675 Munich (Germany); Rohde, Franziska; Janssen, Klaus-Peter [Chirurgische Klinik und Poliklinik, Technische Universitaet Muenchen, Munich (Germany); Essler, Markus [Nuklearmedizinische Klinik und Poliklinik, Technische Universitaet Muenchen, Ismaninger Strasse 22, 81675 Munich (Germany)

2010-02-01

Tumor endothelial marker (TEM) 5 is an adhesion G-protein-coupled receptor upregulated in endothelial cells during tumor and physiologic angiogenesis. So far, the mechanisms leading to upregulation of TEM5 and its function during angiogenesis have not been identified. Here, we report that TEM5 expression in endothelial cells is induced during capillary-like network formation on Matrigel, during capillary morphogenesis in a three-dimensional collagen I matrix, and upon confluence on a two-dimensional matrix. TEM5 expression was not induced by a variety of soluble angiogenic factors, including VEGF and bFGF, in subconfluent endothelial cells. TEM5 upregulation was blocked by toxin B from Clostridium difficile, an inhibitor of the small GTPases Rho, Rac, and Cdc42. The Rho inhibitor C3 transferase from Clostridium botulinum did not affect TEM5 expression, whereas the Rac inhibitor NSC23766 suppressed TEM5 upregulation. An excess of the soluble TEM5 extracellular domain or an inhibitory monoclonal TEM5 antibody blocked contact inhibition of endothelial cell proliferation resulting in multilayered islands within the endothelial monolayer and increased vessel density during capillary formation. Based on our results we conclude that TEM5 expression during capillary morphogenesis is induced by the small GTPase Rac and mediates contact inhibition of proliferation in endothelial cells.

Dehydroeffusol effectively inhibits human gastric cancer cell-mediated vasculogenic mimicry with low toxicity

Energy Technology Data Exchange (ETDEWEB)

Liu, Wenming; Meng, Mei; Zhang, Bin; Du, Longsheng; Pan, Yanyan; Yang, Ping; Gu, Zhenlun; Zhou, Quansheng, E-mail: quanshengzhou@yahoo.com; Cao, Zhifei, E-mail: hunancao@163.com

2015-09-01

Accumulated data has shown that various vasculogenic tumor cells, including gastric cancer cells, are able to directly form tumor blood vessels via vasculogenic mimicry, supplying oxygen and nutrients to tumors, and facilitating progression and metastasis of malignant tumors. Therefore, tumor vasculogenic mimicry is a rational target for developing novel anticancer therapeutics. However, effective antitumor vasculogenic mimicry-targeting drugs are not clinically available. In this study, we purified 2,7-dihydroxyl-1-methyl-5-vinyl-phenanthrene, termed dehydroeffusol, from the traditional Chinese medicinal herb Juncus effusus L., and found that dehydroeffusol effectively inhibited gastric cancer cell-mediated vasculogenic mimicry in vitro and in vivo with very low toxicity. Dehydroeffusol significantly suppressed gastric cancer cell adhesion, migration, and invasion. Molecular mechanistic studies revealed that dehydroeffusol markedly inhibited the expression of a vasculogenic mimicry master gene VE-cadherin and reduced adherent protein exposure on the cell surface by inhibiting gene promoter activity. In addition, dehydroeffusol significantly decreased the expression of a key vasculogenic gene matrix metalloproteinase 2 (MMP2) in gastric cancer cells, and diminished MMP2 protease activity. Together, our results showed that dehydroeffusol effectively inhibited gastric cancer cell-mediated vasculogenic mimicry with very low toxicity, suggesting that dehydroeffusol is a potential drug candidate for anti-gastric cancer neovascularization and anti-gastric cancer therapy. - Highlights: • Dehydroeffusol markedly inhibits gastric cancer cell-mediated vasculogenic mimicry. • Dehydroeffusol suppresses the expression of vasculogenic mimicry key gene VE-cadherin. • Dehydroeffusol decreases the MMP2 expression and activity in gastric cancer cells. • Dehydroeffusol is a potential anti-cancer drug candidate with very low toxicity.

DNER, an epigenetically modulated gene, regulates glioblastoma-derived neurosphere cell differentiation and tumor propagation.

Science.gov (United States)

Sun, Peng; Xia, Shuli; Lal, Bachchu; Eberhart, Charles G; Quinones-Hinojosa, Alfredo; Maciaczyk, Jarek; Matsui, William; Dimeco, Francesco; Piccirillo, Sara M; Vescovi, Angelo L; Laterra, John

2009-07-01

Neurospheres derived from glioblastoma (GBM) and other solid malignancies contain neoplastic stem-like cells that efficiently propagate tumor growth and resist cytotoxic therapeutics. The primary objective of this study was to use histone-modifying agents to elucidate mechanisms by which the phenotype and tumor-promoting capacity of GBM-derived neoplastic stem-like cells are regulated. Using established GBM-derived neurosphere lines and low passage primary GBM-derived neurospheres, we show that histone deacetylase (HDAC) inhibitors inhibit growth, induce differentiation, and induce apoptosis of neoplastic neurosphere cells. A specific gene product induced by HDAC inhibition, Delta/Notch-like epidermal growth factor-related receptor (DNER), inhibited the growth of GBM-derived neurospheres, induced their differentiation in vivo and in vitro, and inhibited their engraftment and growth as tumor xenografts. The differentiating and tumor suppressive effects of DNER, a noncanonical Notch ligand, contrast with the previously established tumor-promoting effects of canonical Notch signaling in brain cancer stem-like cells. Our findings are the first to implicate noncanonical Notch signaling in the regulation of neoplastic stem-like cells and suggest novel neoplastic stem cell targeting treatment strategies for GBM and potentially other solid malignancies.

Cyclic AMP induces apoptosis in multiple myeloma cells and inhibits tumor development in a mouse myeloma model

International Nuclear Information System (INIS)

Follin-Arbelet, Virginie; Hofgaard, Peter O; Hauglin, Harald; Naderi, Soheil; Sundan, Anders; Blomhoff, Rune; Bogen, Bjarne; Blomhoff, Heidi K

2011-01-01

Multiple myeloma is an incurable disease requiring the development of effective therapies which can be used clinically. We have elucidated the potential for manipulating the cAMP signaling pathway as a target for inhibiting the growth of multiple myeloma cells. As a model system, we primarily used the murine multiple myeloma cell line MOPC315 which can be grown both in vivo and in vitro. Human multiple myeloma cell lines U266, INA-6 and the B-cell precursor acute lymphoblastic leukemia cell line Reh were used only for in vitro studies. Cell death was assessed by flow cytometry and western blot analysis after treatment with cAMP elevating agents (forskolin, prostaglandin E2 and rolipram) and cAMP analogs. We followed tumor growth in vivo after forskolin treatment by imaging DsRed-labelled MOPC315 cells transplanted subcutaneously in BALB/c nude mice. In contrast to the effect on Reh cells, 50 μM forskolin more than tripled the death of MOPC315 cells after 24 h in vitro. Forskolin induced cell death to a similar extent in the human myeloma cell lines U266 and INA-6. cAMP-mediated cell death had all the typical hallmarks of apoptosis, including changes in the mitochondrial membrane potential and cleavage of caspase 3, caspase 9 and PARP. Forskolin also inhibited the growth of multiple myeloma cells in a mouse model in vivo. Elevation of intracellular levels of cAMP kills multiple myeloma cells in vitro and inhibits development of multiple myeloma in vivo. This strongly suggests that compounds activating the cAMP signaling pathway may be useful in the field of multiple myeloma

IL-6 Inhibition With MEDI5117 Decreases The Fraction of Head and Neck Cancer Stem Cells and Prevents Tumor Recurrence

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Kelsey A. Finkel

2016-05-01

Full Text Available Head and neck squamous cell carcinomas (HNSCC exhibit a small population of uniquely tumorigenic cancer stem cells (CSC endowed with self-renewal and multipotency. We have recently shown that IL-6 enhances the survival and tumorigenic potential of head and neck cancer stem cells (i.e. ALDHhighCD44high cells. Here, we characterized the effect of therapeutic inhibition of IL-6 with a novel humanized anti-IL-6 antibody (MEDI5117 using three low-passage patient-derived xenograft (PDX models of HNSCC. We observed that single agent MEDI5117 inhibited the growth of PDX-SCC-M1 tumors (P < .05. This PDX model was generated from a previously untreated HNSCC. In contrast, MEDI5117 was not effective at reducing overall tumor volume for PDX models representing resistant disease (PDX-SCC-M0, PDX-SCC-M11. Low dose MEDI5117 (3 mg/kg consistently decreased the fraction of cancer stem cells in PDX models of HNSCC when compared to IgG-treated controls, as follows: PDX-SCC-M0 (P < .001, PDX-SCC-M1 (P < .001, PDX-SCC-M11 (P = .04. Interestingly, high dose MEDI5117 (30 mg/kg decreased the CSC fraction in the PDX-SCC-M11 model (P = .002, but not in PDX-SCC-M0 and PDX-SCC-M1. MEDI5117 mediated a dose-dependent decrease in the number of orospheres generated by ALDHhighCD44high cells cultured in ultra-low attachment plates (P < .05, supporting an inhibitory effect on head and neck cancer stem cells. Notably, single agent MEDI5117 reduced the overall recurrence rate of PDX-SCC-M0, a PDX generated from the local recurrence of human HNSCC. Collectively, these data demonstrate that therapeutic inhibition of IL-6 with low-dose MEDI5117 decreases the fraction of cancer stem cells, and that adjuvant MEDI5117 inhibits recurrence in preclinical models of HNSCC.

Enhanced Radiosensitivity of Tumor Cells Treated with Vanadate in Vitro

International Nuclear Information System (INIS)

Lee, Myung Za; Lee, Won Young

1994-01-01

Intracellular ions which have a major role in cellular function have been reported to affect repair of radiation damage. Recently it has been reported that ouabain sensitizes A549 tumor cells hut not CCL-120 normal cells to radiation. Ouabain inhibits the Na+-K+-pump rapidly thus it increases intracellular Na concentration. Vanadate which is distributed extensively in almost all living organisms in known to be a Na+-K+-ATPase inhibitors. This study was performed to see any change in radiosensitivity of tumor cell by vanadate and any role of Na+-K+-ATPase in radiosensitization. Experiments have been carried out by pretreatment with vanadate in human cell line(A549, JMG) and mouse cell line(L1210, spleen). For the cell survival MTT assay was performed for A549 and JMG cell and trypan blue dye exclusion test for L120, and spleen cells. Measurements of Na+-K+-ATPase activity in control, vanadate treated cell, radiation treated cell (9 Gy for A549 and JMG, 2 Gy for L1201, spleen), and combined 10-6 M vanadate and radiation treated cells were done. The results were summarized as follows. 1. L1210 cell was most radiosensitive, and spleen cell and JMG cell were intermediate, and A549 cell was least radiosensitive. 2. Minimum or cytotoxicity was seen with vanadate below concentration of 10-6 M. 3. In A549 cells there was a little change in radiosensitivity with treatment of vanadate. However radiation sensitization was shown in low dose level of radiation i. E. 2-Gy. In JMG cells no change in radiosensitivity was noted. Both L1210 and spleen cell had radiosensitization but change was greater in tumor cell. 4. Na+-K+-ATPase activity was inhibited significantly in tumor cell by treatment of vanadate. 5. Radiation itself inhibited Na+-K+-ATPase activity of tumor cell with high Na+- K+-ATPase concention. Increase in radiosensitivity by vanadate was closely associated with original Na+-K+-ATPase contents. From the above results vanadate had little cytotoxicity and it sensitized

Epithelial-mesenchymal transition increases tumor sensitivity to COX-2 inhibition by apricoxib.

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Kirane, Amanda; Toombs, Jason E; Larsen, Jill E; Ostapoff, Katherine T; Meshaw, Kathryn R; Zaknoen, Sara; Brekken, Rolf A; Burrows, Francis J

2012-09-01

Although cyclooxygenase-2 (COX-2) inhibitors, such as the late stage development drug apricoxib, exhibit antitumor activity, their mechanisms of action have not been fully defined. In this study, we characterized the mechanisms of action of apricoxib in HT29 colorectal carcinoma. Apricoxib was weakly cytotoxic toward naive HT29 cells in vitro but inhibited tumor growth markedly in vivo. Pharmacokinetic analyses revealed that in vivo drug levels peaked at 2-4 µM and remained sufficient to completely inhibit prostaglandin E(2) production, but failed to reach concentrations cytotoxic for HT29 cells in monolayer culture. Despite this, apricoxib significantly inhibited tumor cell proliferation and induced apoptosis without affecting blood vessel density, although it did promote vascular normalization. Strikingly, apricoxib treatment induced a dose-dependent reversal of epithelial-mesenchymal transition (EMT), as shown by robust upregulation of E-cadherin and the virtual disappearance of vimentin and ZEB1 protein expression. In vitro, either anchorage-independent growth conditions or forced EMT sensitized HT29 and non-small cell lung cancer cells to apricoxib by 50-fold, suggesting that the occurrence of EMT may actually increase the dependence of colon and lung carcinoma cells on COX-2. Taken together, these data suggest that acquisition of mesenchymal characteristics sensitizes carcinoma cells to apricoxib resulting in significant single-agent antitumor activity.

Lactic acid in tumor microenvironments causes dysfunction of NKT cells by interfering with mTOR signaling.

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Xie, Di; Zhu, Shasha; Bai, Li

2016-12-01

Cellular metabolism has been shown to regulate differentiation and function of immune cells. Tumor associated immune cells undergo phenotypic and functional alterations due to the change of cellular metabolism in tumor microenvironments. NKT cells are good candidates for immunotherapies against tumors and have been used in several clinical trials. However, the influences of tumor microenvironments on NKT cell functions remain unclear. In our studies, lactic acid in tumor microenvironments inhibited IFNγ and IL4 productions from NKT cells, and more profound influence on IFNγ was observed. By adjusting the pH of culture medium we further showed that, dysfunction of NKT cells could simply be induced by low extracellular pH. Moreover, low extracellular pH inhibited NKT cell functions by inhibiting mammalian target of rapamycin (mTOR) signaling and nuclear translocation of promyelocytic leukemia zinc-finger (PLZF). Together, our results suggest that tumor acidic microenvironments could interfere with NKT cell functions through metabolic controls.

(+)-Nootkatone inhibits tumor necrosis factor α/interferon γ-induced production of chemokines in HaCaT cells.

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Choi, Hyeon-Jae; Lee, Jin-Hwee; Jung, Yi-Sook

2014-05-02

Chemokines are important mediators of cell migration, and thymus and activation-regulated chemokine (TARC/CCL17) and macrophage-derived chemokine (MDC/CCL22) are well-known typical inflammatory chemokines involved in atopic dermatitis (AD). (+)-Nootkatone is the major component of Cyperus rotundus. (+)-Nootkatone has antiallergic, anti-inflammatory, and antiplatelet activities. The purpose of this study was to investigate the effect of (+)-nootkatone on tumor necrosis factor α (TNF-α)/interferon γ (IFN-γ)-induced expression of Th2 chemokines in HaCaT cells. We found that (+)-nootkatone inhibited the TNF-α/IFN-γ-induced expression of TARC/CCL17 and MDC/CCL22 mRNA in HaCaT cells. It also significantly inhibited TNF-α/IFN-γ-induced activation of nuclear factor kappa B (NF-κB), p38 mitogen-activated protein kinase (MAPK), and protein kinase Cζ (PKCζ). Furthermore, we showed that PKCζ and p38 MAPK contributed to the inhibition of TNF-α/IFN-γ-induced TARC/CCL17 and MDC/CCL22 expression by blocking IκBα degradation in HaCaT cells. Taken together, these results suggest that (+)-nootkatone may suppress TNF-α/IFN-γ-induced TARC/CCL17 and MDC/CCL22 expression in HaCaT cells by inhibiting of PKCζ and p38 MAPK signaling pathways that lead to activation of NF-κB. We propose that (+)-nootkatone may be a useful therapeutic candidate for inflammatory skin diseases such as AD. Copyright © 2014 Elsevier Inc. All rights reserved.

A novel rabbit anti-hepatocyte growth factor monoclonal neutralizing antibody inhibits tumor growth in prostate cancer cells and mouse xenografts

International Nuclear Information System (INIS)

Yu, Yanlan; Chen, Yicheng; Ding, Guoqing; Wang, Mingchao; Wu, Haiyang; Xu, Liwei; Rui, Xuefang; Zhang, Zhigen

2015-01-01

The hepatocyte growth factor and its receptor c-Met are correlated with castration-resistance in prostate cancer. Although HGF has been considered as an attractive target for therapeutic antibodies, the lack of cross-reactivity of monoclonal antibodies with human/mouse HGFs is a major obstacle in preclinical developments. We generated a panel of anti-HGF RabMAbs either blocking HGF/c-Met interaction or inhibiting c-Met phosphorylation. We selected one RabMAb with mouse cross-reactivity and demonstrated that it blocked HGF-stimulated downstream activation in PC-3 and DU145 cells. Anti-HGF RabMAb inhibited not only the growth of PC-3 cells but also HGF-dependent proliferation in HUVECs. We further demonstrated the efficacy and potency of the anti-HGF RabMAb in tumor xenograft mice models. Through these in vitro and in vivo experiments, we explored a novel therapeutic antibody for advanced prostate cancer. - Highlights: • HGF is an attractive target for castration-refractory prostate cancer. • We generated and characterized a panel of anti-HGF rabbit monoclonal antibodies. • More than half of these anti-HGF RabMAbs was cross-reactive with mouse HGF. • Anti-HGF RabMAb blocks HGF-stimulated phosphorylation and cell growth in vitro. • Anti-HGF RabMAb inhibits tumor growth and angiogenesis in xenograft mice

A novel rabbit anti-hepatocyte growth factor monoclonal neutralizing antibody inhibits tumor growth in prostate cancer cells and mouse xenografts

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Yu, Yanlan; Chen, Yicheng; Ding, Guoqing; Wang, Mingchao; Wu, Haiyang; Xu, Liwei; Rui, Xuefang; Zhang, Zhigen, E-mail: srrshurology@163.com

2015-08-14

The hepatocyte growth factor and its receptor c-Met are correlated with castration-resistance in prostate cancer. Although HGF has been considered as an attractive target for therapeutic antibodies, the lack of cross-reactivity of monoclonal antibodies with human/mouse HGFs is a major obstacle in preclinical developments. We generated a panel of anti-HGF RabMAbs either blocking HGF/c-Met interaction or inhibiting c-Met phosphorylation. We selected one RabMAb with mouse cross-reactivity and demonstrated that it blocked HGF-stimulated downstream activation in PC-3 and DU145 cells. Anti-HGF RabMAb inhibited not only the growth of PC-3 cells but also HGF-dependent proliferation in HUVECs. We further demonstrated the efficacy and potency of the anti-HGF RabMAb in tumor xenograft mice models. Through these in vitro and in vivo experiments, we explored a novel therapeutic antibody for advanced prostate cancer. - Highlights: • HGF is an attractive target for castration-refractory prostate cancer. • We generated and characterized a panel of anti-HGF rabbit monoclonal antibodies. • More than half of these anti-HGF RabMAbs was cross-reactive with mouse HGF. • Anti-HGF RabMAb blocks HGF-stimulated phosphorylation and cell growth in vitro. • Anti-HGF RabMAb inhibits tumor growth and angiogenesis in xenograft mice.

Targeted inhibition of osteosarcoma tumor growth by bone marrow-derived mesenchymal stem cells expressing cytosine deaminase/5-fluorocytosine in tumor-bearing mice.

Science.gov (United States)

NguyenThai, Quynh-Anh; Sharma, Neelesh; Luong, Do Huynh; Sodhi, Simrinder Singh; Kim, Jeong-Hyun; Kim, Nameun; Oh, Sung-Jong; Jeong, Dong Kee

2015-01-01

Mesenchymal stem cells (MSCs) are considered as an attractive approach for gene or drug delivery in cancer therapy. In the present study, the ability of human bone marrow-derived MSCs expressing the cytosine deaminase/5-fluorocytosine prodrug (CD/5-FC MSCs) to target the human osteosarcoma cell line Cal72 was evaluated. The stable CD/5-FC MSC cell line was established by transfection of pEGFP containing the cytosine deaminase gene into MSCs with G418 selection. The anti-tumor effect was verified by a bystander effect assay in vitro and co-injection of Cal72 and CD/5-FC MSCs in cancer-bearing mice. The therapeutic CD/5-FC MSCs retained the characteristics of multipotent cells, such as differentiation into adipocytes/osteocytes and expression of mesenchymal markers (CD90 and CD44), and showed migration toward Cal72 cells to a greater extent than the native MSCs. The bystander effect assay showed that the CD/5-FC MSCs significantly augmented Cal72 cytotoxicity in direct co-culture and in the presence of 5-FC through the application of conditioned medium. In osteosarcoma-bearing mice, the CD/5-FC MSCs inhibited tumor growth compared to control mice subcutaneously injected with only Cal72 cells. Taken together, these findings suggest that CD/5-FC MSCs may be suitable for targeting human osteosarcoma. Copyright © 2015 John Wiley & Sons, Ltd.

Long-term exposure to hypoxia inhibits tumor progression of lung cancer in rats and mice

International Nuclear Information System (INIS)

Yu, Lunyin; Hales, Charles A

2011-01-01

Hypoxia has been identified as a major negative factor for tumor progression in clinical observations and in animal studies. However, the precise role of hypoxia in tumor progression has not been fully explained. In this study, we extensively investigated the effect of long-term exposure to hypoxia on tumor progression in vivo. Rats bearing transplanted tumors consisting of A549 human lung cancer cells (lung cancer tumor) were exposed to hypoxia for different durations and different levels of oxygen. The tumor growth and metastasis were evaluated. We also treated A549 lung cancer cells (A549 cells) with chronic hypoxia and then implanted the hypoxia-pretreated cancer cells into mice. The effect of exposure to hypoxia on metastasis of Lewis lung carcinoma in mice was also investigated. We found that long-term exposure to hypoxia a) significantly inhibited lung cancer tumor growth in xenograft and orthotopic models in rats, b) significantly reduced lymphatic metastasis of the lung cancer in rats and decreased lung metastasis of Lewis lung carcinoma in mice, c) reduced lung cancer cell proliferation and cell cycle progression in vitro, d) decreased growth of the tumors from hypoxia-pretreated A549 cells, e) decreased Na + -K + ATPase α1 expression in hypoxic lung cancer tumors, and f) increased expression of hypoxia inducible factors (HIF1α and HIF2α) but decreased microvessel density in the lung cancer tumors. In contrast to lung cancer, the growth of tumor from HCT116 human colon cancer cells (colon cancer tumor) was a) significantly enhanced in the same hypoxia conditions, accompanied by b) no significant change in expression of Na + -K + ATPase α1, c) increased HIF1α expression (no HIF2α was detected) and d) increased microvessel density in the tumor tissues. This study demonstrated that long-term exposure to hypoxia repressed tumor progression of the lung cancer from A549 cells and that decreased expression of Na + -K + ATPase was involved in hypoxic

LncRNA-LET inhibits cell viability, migration and EMT while induces apoptosis by up-regulation of TIMP2 in human granulosa-like tumor cell line KGN.

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Han, Qingfang; Zhang, Wenke; Meng, Jinlai; Ma, Li; Li, Aihua

2018-04-01

Polycystic ovary syndrome (PCOS) is a common endocrine disease characterized by hyperandrogenism, irregular menses, and polycystic ovaries. Several long non-coding RNAs (lncRNAs) are aberrantly expressed in PCOS patients; however, little is known about the effects of the lncRNA-low expression in tumor (lncRNA-LET) on PCOS. We aimed to explore the effects of lncRNA-LET on human granulosa-like tumor cell line, KGN. Expression of lncRNA-LET in normal IOSE80 cells and granulosa cells was determined by qRT-PCR. KGN cell viability, apoptosis and migration were measured by trypan blue exclusion method, flow cytometry assay and wound healing assay, respectively. TGF-β1 was used to induce epithelial-mesenchymal transition (EMT) process. LncRNA-LET expression and mRNA expressions of TIMP2 and EMT-related proteins were measured by qRT-PCR. Western blot analysis was used to measure the protein expression of apoptosis-related proteins, EMT-related proteins, TIMP2, and the proteins in the Wnt/β-catenin and Notch signaling pathways. lncRNA-LET was down-regulated in KGN cells, and its overexpression inhibited cell viability and migration, and promoted apoptosis in KGN cells. Overexpression of lncRNA-LET increased the expression of E-cadherin and decreased the expressions of N-cadherin and vimentin in KGN cells. These effects of lncRNA-LET on KGN cells were reversed by TIMP2 suppression. Overexpression of TIMP2 inhibited cell viability, migration and EMT process, and increased apoptosis by activating the Wnt/β-catenin and Notch pathways. Overexpression of lncRNA-LET inhibits cell viability, migration and EMT process, and increases apoptosis in KGN cells by up-regulating the expression of TIMP2 and activating the Wnt/β-catenin and notch signaling pathways. Copyright © 2018 Elsevier Masson SAS. All rights reserved.

Transcriptional Inhibition of the Human Papilloma Virus Reactivates Tumor Suppressor p53 in Cervical Carcinoma Cells

Science.gov (United States)

Kochetkov, D. V.; Ilyinskaya, G. V.; Komarov, P. G.; Strom, E.; Agapova, L. S.; Ivanov, A. V.; Budanov, A. V.; Frolova, E. I.; Chumakov, P. M.

2009-01-01

Inactivation of tumor suppressor p53 accompanies the majority of human malignancies. Restoration of p53 function causes death of tumor cells and is potentially suitable for gene therapy of cancer. In cervical carcinoma, human papilloma virus (HPV) E6 facilitates proteasomal degradation of p53. Hence, a possible approach to p53 reactivation is the use of small molecules suppressing the function of viral proteins. HeLa cervical carcinoma cells (HPV-18) with a reporter construct containing the b-galactosidase gene under the control of a p53-responsive promoter were used as a test system to screen a library of small molecules for restoration of the transcriptional activity of p53. The effect of the two most active compounds was studied with cell lines differing in the state of p53-dependent signaling pathways. The compounds each specifically activated p53 in cells expressing HPV-18 and, to a lesser extent, HPV-16 and exerted no effect on control p53-negative cells or cells with the intact p53-dependent pathways. Activation of p53 in cervical carcinoma cells was accompanied by induction of p53-dependent CDKN1 (p21), inhibition of cell proliferation, and induction of apoptosis. In addition, the two compounds dramatically decreased transcription of the HPV genome, which was assumed to cause p53 reactivation. The compounds were low-toxic for normal cells and can be considered as prototypes of new anticancer drugs. PMID:17685229

Emblica officinalis extract induces autophagy and inhibits human ovarian cancer cell proliferation, angiogenesis, growth of mouse xenograft tumors.

Directory of Open Access Journals (Sweden)

Alok De

Full Text Available Patients with ovarian cancer (OC may be treated with surgery, chemotherapy and/or radiation therapy, although none of these strategies are very effective. Several plant-based natural products/dietary supplements, including extracts from Emblicaofficinalis (Amla, have demonstrated potent anti-neoplastic properties. In this study we determined that Amla extract (AE has anti-proliferative effects on OC cells under both in vitro and in vivo conditions. We also determined the anti-proliferative effects one of the components of AE, quercetin, on OC cells under in vitro conditions. AE did not induce apoptotic cell death, but did significantly increase the expression of the autophagic proteins beclin1 and LC3B-II under in vitro conditions. Quercetin also increased the expression of the autophagic proteins beclin1 and LC3B-II under in vitro conditions. AE also significantly reduced the expression of several angiogenic genes, including hypoxia-inducible factor 1α (HIF-1α in OVCAR3 cells. AE acted synergistically with cisplatin to reduce cell proliferation and increase expression of the autophagic proteins beclin1 and LC3B-II under in vitro conditions. AE also had anti-proliferative effects and induced the expression of the autophagic proteins beclin1 and LC3B-II in mouse xenograft tumors. Additionally, AE reduced endothelial cell antigen - CD31 positive blood vessels and HIF-1α expression in mouse xenograft tumors. Together, these studies indicate that AE inhibits OC cell growth both in vitro and in vivo possibly via inhibition of angiogenesis and activation of autophagy in OC. Thus AE may prove useful as an alternative or adjunct therapeutic approach in helping to fight OC.

Isolated tumoral pyruvate dehydrogenase can synthesize acetoin which inhibits pyruvate oxidation as well as other aldehydes.

Science.gov (United States)

Baggetto, L G; Lehninger, A L

1987-05-29

Oxidation of 1 mM pyruvate by Ehrlich and AS30-D tumor mitochondria is inhibited by acetoin, an unusual and important metabolite of pyruvate utilization by cancer cells, by acetaldehyde, methylglyoxal and excess pyruvate. The respiratory inhibition is reversed by other substrates added to pyruvate and also by 0.5 mM ATP. Kinetic properties of pyruvate dehydrogenase complex isolated from these tumor mitochondria have been studied. This complex appears to be able to synthesize acetoin from acetaldehyde plus pyruvate and is competitively inhibited by acetoin. The role of a new regulatory pattern for tumoral pyruvate dehydrogenase is presented.

Metformin inhibits epithelial–mesenchymal transition in prostate cancer cells: Involvement of the tumor suppressor miR30a and its target gene SOX4

International Nuclear Information System (INIS)

Zhang, Jing; Shen, Chengwu; Wang, Lin; Ma, Quanping; Xia, Pingtian; Qi, Mei; Yang, Muyi; Han, Bo

2014-01-01

Highlights: • Metformin inhibits TGF-β-induced EMT in prostate cancer (PCa) cells. • Metformin upregulates tumor suppressor miR30a and downregulates SOX4 in PCa cells. • SOX4 is a target gene of miR30a. - Abstract: Tumor metastasis is the leading cause of mortality and morbidity of prostate cancer (PCa) patients. Epithelial–mesenchymal transition (EMT) plays a critical role in cancer progression and metastasis. Recent evidence suggested that diabetic patients treated with metformin have lower PCa risk and better prognosis. This study was aimed to investigate the effects of metformin on EMT in PCa cells and the possible microRNA (miRNA)-based mechanisms. MiRNAs have been shown to regulate various processes of cancer metastasis. We herein showed that metformin significantly inhibits proliferation of Vcap and PC-3 cells, induces G0/G1 cell cycle arrest and inhibits invasiveness and motility capacity of Vcap cells. Metformin could inhibit TGF-β-induced EMT in Vcap cells, as manifested by inhibition of the increase of N-cadherin (p = 0.013), Vimentin (p = 0.002) and the decrease of E-cadherin (p = 0.0023) and β-catenin (p = 0.034) at mRNA and protein levels. Notably, we demonstrated significant upregulation of miR30a levels by metformin (P < 0.05) and further experiments indicated that miR30a significantly inhibits proliferation and EMT process of Vcap cells. Interestingly, we identified that SOX4, a previously reported oncogenic transcriptional factor and modulator of EMT, is a direct target gene of miR30a. Finally, we screened the expression of miR30a and SOX4 in 84 PCa cases with radical prostatectomy. Of note, SOX4 overexpression is significantly associated with decreased levels of miR30a in PCa cases. In all, our study suggested that inhibition of EMT by metformin in PCa cells may involve upregulation of miR30a and downregulation of SOX4

Curcumin targets fibroblast–tumor cell interactions in oral squamous cell carcinoma

International Nuclear Information System (INIS)

Dudás, József; Fullár, Alexandra; Romani, Angela; Pritz, Christian; Kovalszky, Ilona; Hans Schartinger, Volker; Mathias Sprinzl, Georg; Riechelmann, Herbert

2013-01-01

Co-culture of periodontal ligament fibroblasts (PDLs) and SCC-25 oral squamous carcinoma cells (OSCC) results in conversion of PDLs into carcinoma-associated fibroblasts (CAFs) and induces epithelial-to mesenchymal transition (EMT) of OSCC tumor cells. We hypothesized that Curcumin targets this dynamic mutual interaction between CAFs and tumor cells. Normal and 2 μM Curcumin-treated co-culture were performed for 4 days, followed by analysis of tumor cell invasivity, mRNA/protein expression of EMT-markers and mediators, activity measure of matrix metalloproteinase 9 (MMP-9), and western blot analysis of signal transduction in tumor cells and fibroblasts. In Curcumin-treated co-culture, in tumor cells, the levels of nuclear factor κB (NFκBα) and early response kinase (ERK)—decreased, in fibroblasts, integrin αv protein synthesis decreased compared to corresponding cells in normal co-culture. The signal modulatory changes induced by Curcumin caused decreased release of EMT-mediators in CAFs and reversal of EMT in tumor cells, which was associated with decreased invasion. These data confirm the palliative potential of Curcumin in clinical application. - Graphical abstract: Co-culture of periodontal ligament fibroblasts (PDLs) and SCC-25 oral squamous carcinoma cells (OSCC) results in conversion of PDLs into carcinoma-associated fibroblasts (CAFs) and induces epithelial-to mesenchymal transition (EMT) of tumor cells. Curcumin targets this dynamic mutual interaction between CAFs and tumor cells by inhibiting the production of EMT mediators in CAFs and by modification of intracellular signaling in tumor cells. This causes less invasivity and reversal of EMT in tumor cells. Highlights: ► Curcumin targets tumor–fibroblast interaction in head and neck cancer. ► Curcumin suppresses mediators of epithelial–mesenchymal transition. ► Curcumin decreases the invasivity of tumor cells

Curcumin targets fibroblast–tumor cell interactions in oral squamous cell carcinoma

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Dudás, József, E-mail: jozsef.dudas@i-med.ac.at [Department of Otorhinolaryngology and Head and Neck Surgery, Medical University Innsbruck, Anichstrasse 35, A-6020 Innsbruck (Austria); Fullár, Alexandra, E-mail: fullarsz@gmail.com [Department of Otorhinolaryngology and Head and Neck Surgery, Medical University Innsbruck, Anichstrasse 35, A-6020 Innsbruck (Austria); 1st Department of Pathology and Experimental Cancer Research, Semmelweis University, Üllői út 26, 1085 Budapest (Hungary); Romani, Angela, E-mail: angela.romani@i-med.ac.at [Department of Otorhinolaryngology and Head and Neck Surgery, Medical University Innsbruck, Anichstrasse 35, A-6020 Innsbruck (Austria); Pritz, Christian, E-mail: christian.pritz@i-med.ac.at [Department of Otorhinolaryngology and Head and Neck Surgery, Medical University Innsbruck, Anichstrasse 35, A-6020 Innsbruck (Austria); Kovalszky, Ilona, E-mail: koval@korb1.sote.hu [1st Department of Pathology and Experimental Cancer Research, Semmelweis University, Üllői út 26, 1085 Budapest (Hungary); Hans Schartinger, Volker, E-mail: volker.schartinger@i-med.ac.at [Department of Otorhinolaryngology and Head and Neck Surgery, Medical University Innsbruck, Anichstrasse 35, A-6020 Innsbruck (Austria); Mathias Sprinzl, Georg, E-mail: georg.sprinzl@i-med.ac.at [Department of Otorhinolaryngology and Head and Neck Surgery, Medical University Innsbruck, Anichstrasse 35, A-6020 Innsbruck (Austria); Riechelmann, Herbert, E-mail: herbert.riechelmann@i-med.ac.at [Department of Otorhinolaryngology and Head and Neck Surgery, Medical University Innsbruck, Anichstrasse 35, A-6020 Innsbruck (Austria)

2013-04-01

Co-culture of periodontal ligament fibroblasts (PDLs) and SCC-25 oral squamous carcinoma cells (OSCC) results in conversion of PDLs into carcinoma-associated fibroblasts (CAFs) and induces epithelial-to mesenchymal transition (EMT) of OSCC tumor cells. We hypothesized that Curcumin targets this dynamic mutual interaction between CAFs and tumor cells. Normal and 2 μM Curcumin-treated co-culture were performed for 4 days, followed by analysis of tumor cell invasivity, mRNA/protein expression of EMT-markers and mediators, activity measure of matrix metalloproteinase 9 (MMP-9), and western blot analysis of signal transduction in tumor cells and fibroblasts. In Curcumin-treated co-culture, in tumor cells, the levels of nuclear factor κB (NFκBα) and early response kinase (ERK)—decreased, in fibroblasts, integrin αv protein synthesis decreased compared to corresponding cells in normal co-culture. The signal modulatory changes induced by Curcumin caused decreased release of EMT-mediators in CAFs and reversal of EMT in tumor cells, which was associated with decreased invasion. These data confirm the palliative potential of Curcumin in clinical application. - Graphical abstract: Co-culture of periodontal ligament fibroblasts (PDLs) and SCC-25 oral squamous carcinoma cells (OSCC) results in conversion of PDLs into carcinoma-associated fibroblasts (CAFs) and induces epithelial-to mesenchymal transition (EMT) of tumor cells. Curcumin targets this dynamic mutual interaction between CAFs and tumor cells by inhibiting the production of EMT mediators in CAFs and by modification of intracellular signaling in tumor cells. This causes less invasivity and reversal of EMT in tumor cells. Highlights: ► Curcumin targets tumor–fibroblast interaction in head and neck cancer. ► Curcumin suppresses mediators of epithelial–mesenchymal transition. ► Curcumin decreases the invasivity of tumor cells.

An inhibitor of K+ channels modulates human endometrial tumor-initiating cells

Directory of Open Access Journals (Sweden)

Leslie Kimberly K

2011-08-01

Full Text Available Abstract Background Many potassium ion (K+ channels function as oncogenes to sustain growth of solid tumors, but their role in cancer progression is not well understood. Emerging evidence suggests that the early progenitor cancer cell subpopulation, termed tumor initiating cells (TIC, are critical to cancer progression. Results A non-selective antagonist of multiple types of K+ channels, tetraethylammonium (TEA, was found to suppress colony formation in endometrial cancer cells via inhibition of putative TIC. The data also indicated that withdrawal of TEA results in a significant enhancement of tumorigenesis. When the TIC-enriched subpopulation was isolated from the endometrial cancer cells, TEA was also found to inhibit growth in vitro. Conclusions These studies suggest that the activity of potassium channels significantly contributes to the progression of endometrial tumors, and the antagonists of potassium channels are candidate anti-cancer drugs to specifically target tumor initiating cells in endometrial cancer therapy.

PI3K/Akt signaling mediated Hexokinase-2 expression inhibits cell apoptosis and promotes tumor growth in pediatric osteosarcoma

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Zhuo, Baobiao; Li, Yuan; Li, Zhengwei; Qin, Haihui; Sun, Qingzeng; Zhang, Fengfei; Shen, Yang; Shi, Yingchun [Department of Surgery, The Children' s Hospital of Xuzhou, Xuzhou, Jiangsu Province 221006 (China); Wang, Rong, E-mail: wangrong2008163@163.com [Department of Ultrasonography, Affiliated Hospital of Xuzhou Medical College, Xuzhou, Jiangsu Province 221006 (China)

2015-08-21

Accumulating evidence has shown that PI3K/Akt pathway is frequently hyperactivated in osteosarcoma (OS) and contributes to tumor initiation and progression. Altered phenotype of glucose metabolism is a key hallmark of cancer cells including OS. However, the relationship between PI3K/Akt pathway and glucose metabolism in OS remains largely unexplored. In this study, we showed that elevated Hexokinase-2 (HK2) expression, which catalyzes the first essential step of glucose metabolism by conversion of glucose into glucose-6-phosphate, was induced by activated PI3K/Akt signaling. Immunohistochemical analysis showed that HK2 was overexpressed in 83.3% (25/30) specimens detected and was closely correlated with Ki67, a cell proliferation index. Silencing of endogenous HK2 resulted in decreased aerobic glycolysis as demonstrated by reduced glucose consumption and lactate production. Inhibition of PI3K/Akt signaling also suppressed aerobic glycolysis and this effect can be reversed by reintroduction of HK2. Furthermore, knockdown of HK2 led to increased cell apoptosis and reduced ability of colony formation; meanwhile, these effects were blocked by 2-Deoxy-D-glucose (2-DG), a glycolysis inhibitor through its actions on hexokinase, indicating that HK2 functions in cell apoptosis and growth were mediated by altered aerobic glycolysis. Taken together, our study reveals a novel relationship between PI3K/Akt signaling and aerobic glycolysis and indicates that PI3K/Akt/HK2 might be potential therapeutic approaches for OS. - Highlights: • PI3K/Akt signaling contributes to elevated expression of HK2 in osteosarcoma. • HK2 inhibits cell apoptosis and promotes tumor growth through enhanced Warburg effect. • Inhibition of glycolysis blocks the oncogenic activity of HK2.

Fibroblast growth factor receptor mediates fibroblast-dependent growth in EMMPRIN-depleted head and neck cancer tumor cells.

Science.gov (United States)

Liu, Zhiyong; Hartman, Yolanda E; Warram, Jason M; Knowles, Joseph A; Sweeny, Larissa; Zhou, Tong; Rosenthal, Eben L

2011-08-01

Head and neck squamous cell carcinoma tumors (HNSCC) contain a dense fibrous stroma which is known to promote tumor growth, although the mechanism of stroma-mediated growth remains unclear. As dysplastic mucosal epithelium progresses to cancer, there is incremental overexpression of extracellular matrix metalloprotease inducer (EMMPRIN) which is associated with tumor growth and metastasis. Here, we present evidence that gain of EMMPRIN expression allows tumor growth to be less dependent on fibroblasts by modulating fibroblast growth factor receptor-2 (FGFR2) signaling. We show that silencing EMMPRIN in FaDu and SCC-5 HNSCC cell lines inhibits cell growth, but when EMMPRIN-silenced tumor cells were cocultured with fibroblasts or inoculated with fibroblasts into severe combined immunodeficient mice, the growth inhibition by silencing EMMPRIN was blunted by the presence of fibroblasts. Coculture experiments showed fibroblast-dependent tumor cell growth occurred via a paracrine signaling. Analysis of tumor gene expression revealed expression of FGFR2 was inversely related to EMMPRIN expression. To determine the role of FGFR2 signaling in EMMPRIN-silenced tumor cells, ligands and inhibitors of FGFR2 were assessed. Both FGF1 and FGF2 enhanced tumor growth in EMMPRIN-silenced cells compared with control vector-transfected cells, whereas inhibition of FGFR2 with blocking antibody or with a synthetic inhibitor (PD173074) inhibited tumor cell growth in fibroblast coculture, suggesting the importance of FGFR2 signaling in fibroblast-mediated tumor growth. Analysis of xenografted tumors revealed that EMMPRIN-silenced tumors had a larger stromal compartment compared with control. Taken together, these results suggest that EMMPRIN acquired during tumor progression promotes fibroblast-independent tumor growth.

Fibroblast growth factor receptor mediates fibroblast-dependent growth in EMMPRIN depleted head and neck cancer tumor cells

Science.gov (United States)

Liu, Zhiyong; Hartman, Yolanda E.; Warram, Jason M.; Knowles, Joseph A.; Sweeny, Larrisa; Zhou, Tong; Rosenthal, Eben L.

2011-01-01

Head and neck squamous cell carcinoma tumors (HNSCC) contain a dense fibrous stroma which is known to promote tumor growth, although the mechanism of stroma mediated growth remains unclear. As dysplastic mucosal epithelium progresses to cancer there is incremental overexpression of extracellular matrix metalloprotease inducer (EMMPRIN) which is associated with tumor growth and metastasis. Here we present evidence that gain of EMMPRIN expression allows tumor growth to be less dependent on fibroblasts by modulating fibroblast growth factor receptor-2 (FGFR2) signaling. We show that silencing EMMPRIN in FaDu and SCC-5 HNSCC cell lines inhibits cell growth, but when EMMPRIN-silenced tumor cells were co-cultured with fibroblasts or inoculated with fibroblasts into SCID mice, the growth inhibition by silencing EMMPRIN was blunted by the presence of fibroblasts. Co-culture experiments demonstrated fibroblast-dependent tumor cell growth occurred via a paracrine signaling. Analysis of tumor gene expression revealed expression of FGFR2 was inversely related to EMMPRIN expression. To determine the role of FGFR2 signaling in EMMPRIN silenced tumor cells, ligands and inhibitors of FGFR2 were assessed. Both FGF1 and FGF2 enhanced tumor growth in EMMPRIN silenced cells compared to control vector transfected cells, while inhibition of FGFR2 with blocking antibody or with a synthetic inhibitor (PD173074) inhibited tumor cell growth in fibroblast co-culture, suggesting the importance of FGFR2 signaling in fibroblast mediated tumor growth. Analysis of xenografted tumors revealed EMMPRIN silenced tumors had a larger stromal compartment compared to control. Taken together, these results suggest that EMMPRIN acquired during tumor progression promotes fibroblast independent tumor growth. PMID:21665938

Histological Regression of Giant Cell Tumor of Bone Following RANK Ligand Inhibition

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Martin F. Dietrich MD, PhD

2014-11-01

Full Text Available Lung metastases are a rare complication of giant cell tumors of bone. We herein describe an interesting case of histological regression and size reduction of lung metastases originating from a primary giant cell tumor of bone in response to the RANK ligand inhibitor denosumab.

The receptor tyrosine kinase inhibitor amuvatinib (MP470) sensitizes tumor cells to radio- and chemo-therapies in part by inhibiting homologous recombination

International Nuclear Information System (INIS)

Zhao, Helen; Luoto, Kaisa R.; Meng, Alice X.; Bristow, Robert G.

2011-01-01

Background and purpose: RAD51 is a key protein involved in homologous recombination (HR) and a potential target for radiation- and chemotherapies. Amuvatinib (formerly known as MP470) is a novel receptor tyrosine kinase inhibitor that targets c-KIT and PDGFRα and can sensitize tumor cells to ionizing radiation (IR). Here, we studied amuvatinib mechanism on RAD51 and functional HR. Materials and methods: Protein and RNA analyses, direct repeat green fluorescent protein (DR-GFP) assay and polysomal fractioning were used to measure HR efficiency and global translation in amuvatinib-treated H1299 lung carcinoma cells. Synergy of amuvatinib with IR or mitomycin c (MMC) was assessed by clonogenic survival assay. Results: Amuvaninib inhibited RAD51 protein expression and HR. This was associated with reduced ribosomal protein S6 phosphorylation and inhibition of global translation. Amuvatinib sensitized cells to IR and MMC, agents that are selectively toxic to HR-deficient cells. Conclusions: Amuvatinib is a promising agent that may be used to decrease tumor cell resistance. Our work suggests that this is associated with decreased RAD51 expression and function and supports the further study of amuvatinib in combination with chemotherapy and radiotherapy.

Phytochemical Compositions of Immature Wheat Bran, and Its Antioxidant Capacity, Cell Growth Inhibition, and Apoptosis Induction through Tumor Suppressor Gene

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Mi Jeong Kim

2016-09-01

Full Text Available The purpose of this study was to investigate the phytochemical compositions and antioxidant capacity, cell growth inhibition, and apoptosis induction in extracts of immature wheat bran. Immature wheat bran (IWB was obtained from immature wheat harvested 10 days earlier than mature wheat. The phytochemical compositions of bran extract samples were analyzed by ultra-high performance liquid chromatography. The total ferulic acid (3.09 mg/g and p-coumaric acid (75 µg/g in IWB were significantly higher than in mature wheat bran (MWB, ferulic acid: 1.79 mg/g; p-coumaric acid: 55 µg/g. The oxygen radical absorbance capacity (ORAC: 327 µM Trolox equivalents (TE/g and cellular antioxidant activity (CAA: 4.59 µM Quercetin equivalents (QE/g of the IWB were higher than those of the MWB (ORAC: 281 µM TE/g; CAA: 0.63 µM QE/g. When assessing cell proliferation, the IWB extracts resulted in the lowest EC50 values against HT-29 (18.9 mg/mL, Caco-2 (7.74 mg/mL, and HeLa cells (8.17 mg/mL among bran extract samples. Additionally, the IWB extracts increased the gene expression of p53 and PTEN (tumor suppressor genes in HT-29 cells, indicating inhibited cell growth and induced apoptosis through tumor suppressor genes.

Tumor-targeted inhibition by a novel strategy - mimoretrovirus expressing siRNA targeting the Pokemon gene.

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Tian, Zhiqiang; Wang, Huaizhi; Jia, Zhengcai; Shi, Jinglei; Tang, Jun; Mao, Liwei; Liu, Hongli; Deng, Yijing; He, Yangdong; Ruan, Zhihua; Li, Jintao; Wu, Yuzhang; Ni, Bing

2010-12-01

Pokemon gene has crucial but versatile functions in cell differentiation, proliferation and tumorigenesis. It is a master regulator of the ARF-HDM2-p53 and Rb-E2F pathways. The facts that the expression of Pokemon is essential for tumor formation and many kinds of tumors over-express the Pokemon gene make it an attractive target for therapeutic intervention for cancer treatment. In this study, we used an RNAi strategy to silence the Pokemon gene in a cervical cancer model. To address the issues involving tumor specific delivery and durable expression of siRNA, we applied the Arg-Gly-Asp (RGD) peptide ligand and polylysine (K(18)) fusion peptide to encapsulate a recombinant retrovirus plasmid expressing a siRNA targeting the Pokemon gene and produced the 'mimoretrovirus'. At charge ratio 2.0 of fusion peptide/plasmid, the mimoretrovirus formed stable and homogenous nanoparticles, and provided complete DNase I protection and complete gel retardation. This nanoparticle inhibited SiHa cell proliferation and invasion, while it promoted SiHa cell apoptosis. The binding of the nanoparticle to SiHa cells was mediated via the RGD-integrin α(v)β(3) interaction, as evidenced by the finding that unconjugated RGD peptide inhibited this binding significantly. This tumor-targeting mimoretrovirus exhibited excellent anti-tumor capacity in vivo in a nude mouse model. Moreover, the mimoretrovirus inhibited tumor growth with a much higher efficiency than recombinant retrovirus expressing siRNA or the K(18)/P4 nanoparticle lacking the RGD peptide. Results suggest that the RNAi/RGD-based mimoretrovirus developed in this study represents a novel anti-tumor strategy that may be applicable to most research involving cancer therapy and, thus, has promising potential as a cervical cancer treatment.

Inhibition of Tumor Angiogenesis and Tumor Growth by the DSL Domain of Human Delta-Like 1 Targeted to Vascular Endothelial Cells

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Zhao, Xing-Cheng; Dou, Guo-Rui; Wang, Li; Liang, Liang; Tian, Deng-Mei; Cao, Xiu-Li; Qin, Hong-Yan; Wang, Chun-Mei; Zhang, Ping; Han, Hua

2013-01-01

The growth of solid tumors depends on neovascularization. Several therapies targeting tumor angiogenesis have been developed. However, poor response in some tumors and emerging resistance necessitate further investigations of newdrug targets. Notch signal pathway plays a pivotal role in vascular development and tumor angiogenesis. Either blockade or forced activation of this pathway can inhibit angiogenesis. As blocking Notch pathway results in the formation of vascular neoplasm, activation o...

Human Sulfatase 2 inhibits in vivo tumor growth of MDA-MB-231 human breast cancer xenografts

International Nuclear Information System (INIS)

Peterson, Sarah M; Concino, Michael F; Liaw, Lucy; Martini, Paolo GV; Iskenderian, Andrea; Cook, Lynette; Romashko, Alla; Tobin, Kristen; Jones, Michael; Norton, Angela; Gómez-Yafal, Alicia; Heartlein, Michael W

2010-01-01

Extracellular human sulfatases modulate growth factor signaling by alteration of the heparin/heparan sulfate proteoglycan (HSPG) 6-O-sulfation state. HSPGs bind to numerous growth factor ligands including fibroblast growth factors (FGF), epidermal growth factors (EGF), and vascular endothelial growth factors (VEGF), and are critically important in the context of cancer cell growth, invasion, and metastasis. We hypothesized that sulfatase activity in the tumor microenvironment would regulate tumor growth in vivo. We established a model of stable expression of sulfatases in the human breast cancer cell line MDA-MB-231 and purified recombinant human Sulfatase 2 (rhSulf2) for exogenous administration. In vitro studies were performed to measure effects on breast cancer cell invasion and proliferation, and groups were statistically compared using Student's t-test. The effects of hSulf2 on tumor progression were tested using in vivo xenografts with two methods. First, MDA-MB-231 cells stably expressing hSulf1, hSulf2, or both hSulf1/hSulf2 were grown as xenografts and the resulting tumor growth and vascularization was compared to controls. Secondly, wild type MDA-MB-231 xenografts were treated by short-term intratumoral injection with rhSulf2 or vehicle during tumor growth. Ultrasound analysis was also used to complement caliper measurement to monitor tumor growth. In vivo studies were statistically analyzed using Student's t test. In vitro, stable expression of hSulf2 or administration of rhSulf2 in breast cancer cells decreased cell proliferation and invasion, corresponding to an inhibition of ERK activation. Stable expression of the sulfatases in xenografts significantly suppressed tumor growth, with complete regression of tumors expressing both hSulf1 and hSulf2 and significantly smaller tumor volumes in groups expressing hSulf1 or hSulf2 compared to control xenografts. Despite significant suppression of tumor volume, sulfatases did not affect vascular

Genistein inhibits proliferation of colon cancer cells by attenuating a negative effect of epidermal growth factor on tumor suppressor FOXO3 activity

International Nuclear Information System (INIS)

Qi, Wentao; Weber, Christopher R; Wasland, Kaarin; Savkovic, Suzana D

2011-01-01

Soy consumption is associated with a lower incidence of colon cancer which is believed to be mediated by one of its of components, genistein. Genistein may inhibit cancer progression by inducing apoptosis or inhibiting proliferation, but mechanisms are not well understood. Epidermal growth factor (EGF)-induced proliferation of colon cancer cells plays an important role in colon cancer progression and is mediated by loss of tumor suppressor FOXO3 activity. The aim of this study was to assess if genistein exerts anti-proliferative properties by attenuating the negative effect of EGF on FOXO3 activity. The effect of genistein on proliferation stimulated by EGF-mediated loss of FOXO3 was examined in human colonic cancer HT-29 cells. EGF-induced FOXO3 phosphorylation and translocation were assessed in the presence of genistein. EGF-mediated loss of FOXO3 interactions with p53 (co-immunoprecipitation) and promoter of p27kip1 (ChIP assay) were examined in presence of genistein in cells with mutated p53 (HT-29) and wild type p53 (HCT116). Silencing of p53 determined activity of FOXO3 when it is bound to p53. Genistein inhibited EGF-induced proliferation, while favoring dephosphorylation and nuclear retention of FOXO3 (active state) in colon cancer cells. Upstream of FOXO3, genistein acts via the PI3K/Akt pathway to inhibit EGF-stimulated FOXO3 phosphorylation (i.e. favors active state). Downstream, EGF-induced disassociation of FOXO3 from mutated tumor suppressor p53, but not wild type p53, is inhibited by genistein favoring FOXO3-p53(mut) interactions with the promoter of the cell cycle inhibitor p27kip1 in colon cancer cells. Thus, the FOXO3-p53(mut) complex leads to elevated p27kip1 expression and promotes cell cycle arrest. These novel anti-proliferative mechanisms of genistein suggest a possible role of combining genistein with other chemoreceptive agents for the treatment of colon cancer

Receptor for advanced glycation end products (RAGE) functions as receptor for specific sulfated glycosaminoglycans, and anti-RAGE antibody or sulfated glycosaminoglycans delivered in vivo inhibit pulmonary metastasis of tumor cells.

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Mizumoto, Shuji; Takahashi, Jun; Sugahara, Kazuyuki

2012-06-01

Altered expression of chondroitin sulfate (CS) and heparan sulfate (HS) at the surfaces of tumor cells plays a key role in malignant transformation and tumor metastasis. Previously we demonstrated that a Lewis lung carcinoma (LLC)-derived tumor cell line with high metastatic potential had a higher proportion of E-disaccharide units, GlcUA-GalNAc(4,6-O-disulfate), in CS chains than low metastatic LLC cells and that such CS chains are involved in the metastatic process. The metastasis was markedly inhibited by the pre-administration of CS-E from squid cartilage rich in E units or by preincubation with a phage display antibody specific for CS-E. However, the molecular mechanism of the inhibition remains to be investigated. In this study the receptor molecule for CS chains containing E-disaccharides expressed on LLC cells was revealed to be receptor for advanced glycation end products (RAGE), which is a member of the immunoglobulin superfamily predominantly expressed in the lung. Interestingly, RAGE bound strongly to not only E-disaccharide, but also HS-expressing LLC cells. Furthermore, the colonization of the lungs by LLC cells was effectively inhibited by the blocking of CS or HS chains at the tumor cell surface with an anti-RAGE antibody through intravenous injections in a dose-dependent manner. These results provide the clear evidence that RAGE is at least one of the critical receptors for CS and HS chains expressed at the tumor cell surface and involved in experimental lung metastasis and that CS/HS and RAGE are potential molecular targets in the treatment of pulmonary metastasis.

Dafachronic acid inhibits C. elegans germ cell proliferation in a DAF-12-dependent manner.

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Mukherjee, Madhumati; Chaudhari, Snehal N; Balachandran, Riju S; Vagasi, Alexandra S; Kipreos, Edward T

2017-12-15

Dafachronic acid (DA) is a bile acid-like steroid hormone that regulates dauer formation, heterochrony, and lifespan in C. elegans. Here, we describe that DA is an inhibitor of C. elegans germ stem cell proliferation in adult hermaphrodites. Using a C. elegans germ cell primary culture system, we show that DA inhibits the proliferation of germ cells in vitro. Exogenous DA reduces the frequency of large tumors in adult tumorous germline mutants and decreases the proliferation of wild-type germ stem cells in adult hermaphrodites. In contrast, DA has no appreciable effect on the proliferation of larval-stage germ cells in wild type. The inhibition of adult germ cell proliferation by DA requires its canonical receptor DAF-12. Blocking DA production by inactivating the cytochrome P450 DAF-9 increases germ cell proliferation in wild-type adult hermaphrodites and the frequency of large tumors in germline tumorous mutants, suggesting that DA inhibits the rate of germ cell proliferation under normal growth conditions. Copyright © 2017 Elsevier Inc. All rights reserved.

Gallic acid inhibits gastric cancer cells metastasis and invasive growth via increased expression of RhoB, downregulation of AKT/small GTPase signals and inhibition of NF-κB activity

Energy Technology Data Exchange (ETDEWEB)

Ho, Hsieh-Hsun [Institute of Biochemistry and Biotechnology, Chung Shan Medical University, Taichung 402, Taiwan (China); Chang, Chi-Sen [Department of Medicine, Chung Shan Medical University, Taichung 402, Taiwan (China); Division of Gastroenterology, Taichung Veterans General Hospital, Taichung 402, Taiwan (China); Ho, Wei-Chi [Division of Gastroenterology, Jen-Ai Hospital, Taichung 402, Taiwan (China); Liao, Sheng-You [Institute of Biochemistry and Biotechnology, Chung Shan Medical University, Taichung 402, Taiwan (China); Lin, Wea-Lung [Department of Pathology, School of Medicine, Chung Shan Medical University, Taichung 402, Taiwan (China); Department of Pathology, Chung Shan Medical University Hospital, Taichung 402, Taiwan (China); Wang, Chau-Jong, E-mail: wcj@csmu.edu.tw [Institute of Biochemistry and Biotechnology, Chung Shan Medical University, Taichung 402, Taiwan (China); Department of Medical Research, Chung Shan Medical University Hospital, Taichung 402, Taiwan (China)

2013-01-01

Our previous study demonstrated the therapeutic potential of gallic acid (GA) for controlling tumor metastasis through its inhibitory effect on the motility of AGS cells. A noteworthy finding in our previous experiment was increased RhoB expression in GA-treated cells. The aim of this study was to evaluate the role of RhoB expression on the inhibitory effects of GA on AGS cells. By applying the transfection of RhoB siRNA into AGS cells and an animal model, we tested the effect of GA on inhibition of tumor growth and RhoB expression. The results confirmed that RhoB-siRNA transfection induced GA to inhibit AGS cells’ invasive growth involving blocking the AKT/small GTPase signals pathway and inhibition of NF-κB activity. Finally, we evaluated the effect of GA on AGS cell metastasis by colonization of tumor cells in nude mice. It showed GA inhibited tumor cells growth via the expression of RhoB. These data support the inhibitory effect of GA which was shown to inhibit gastric cancer cell metastasis and invasive growth via increased expression of RhoB, downregulation of AKT/small GTPase signals and inhibition of NF-κB activity. Thus, GA might be a potential agent in treating gastric cancer. Highlights: ► GA could downregulate AKT signal via increased expression of RhoB. ► GA inhibits metastasis in vitro in gastric carcinoma. ► GA inhibits tumor growth in nude mice model.

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

Energy Technology Data Exchange (ETDEWEB)

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

Paclitaxel-Fe3O4 nanoparticles inhibit growth of CD138–  CD34– tumor stem-like cells in multiple myeloma-bearing mice

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Yang C

2013-04-01

Full Text Available Cuiping Yang,1,3,* Jing Wang,2,* Dengyu Chen,1,* Junsong Chen,1 Fei Xiong,4 Hongyi Zhang,1 Yunxia Zhang,2 Ning Gu,4 Jun Dou11Department of Pathogenic Biology and Immunology, Medical School, 2Department of Gynecology and Obstetrics, Zhongda Hospital, Southeast University, Nanjing, 3Department of Pathogenic Biology and Immunology, School of Basic Medicine, Jiangxi University of Traditional Chinese Medicine, Nanchang, 4School of Biological Science and Medical Engineering, Southeast University, Nanjing, People’s Republic of China*These authors contributed equally to this workBackground: There is growing evidence that CD138– CD34– cells may actually be tumor stem cells responsible for initiation and relapse of multiple myeloma. However, effective drugs targeted at CD138– CD34– tumor stem cells are yet to be developed. The purpose of this study was to investigate the inhibitory effect of paclitaxel-loaded Fe3O4 nanoparticles (PTX-NPs on CD138– CD34– tumor stem cells in multiple myeloma-bearing mice.Methods: CD138– CD34– cells were isolated from a human U266 multiple myeloma cell line using an immune magnetic bead sorting method and then subcutaneously injected into mice with nonobese diabetic/severe combined immunodeficiency to develop a multiple myeloma-bearing mouse model. The mice were treated with Fe3O4 nanoparticles 2 mg/kg, paclitaxel 4.8 mg/kg, and PTX-NPs 0.64 mg/kg for 2 weeks. Tumor growth, pathological changes, serum and urinary interleukin-6 levels, and molecular expression of caspase-3, caspase-8, and caspase-9 were evaluated.Results: CD138– CD34– cells were found to have tumor stem cell characteristics. All the mice developed tumors in 40 days after injection of 1 × 106 CD138– CD34– tumor stem cells. Tumor growth in mice treated with PTX-NPs was significantly inhibited compared with the controls (P <  0.005, and the groups that received nanoparticles alone (P < 0.005 or paclitaxel alone (P < 0.05. In addition

Mitochondria-targeted vitamin E analogs inhibit breast cancer cell energy metabolism and promote cell death

International Nuclear Information System (INIS)

Cheng, Gang; Zielonka, Jacek; McAllister, Donna M; Mackinnon, A Craig Jr; Joseph, Joy; Dwinell, Michael B; Kalyanaraman, Balaraman

2013-01-01

Recent research has revealed that targeting mitochondrial bioenergetic metabolism is a promising chemotherapeutic strategy. Key to successful implementation of this chemotherapeutic strategy is the use of new and improved mitochondria-targeted cationic agents that selectively inhibit energy metabolism in breast cancer cells, while exerting little or no long-term cytotoxic effect in normal cells. In this study, we investigated the cytotoxicity and alterations in bioenergetic metabolism induced by mitochondria-targeted vitamin E analog (Mito-chromanol, Mito-ChM) and its acetylated ester analog (Mito-ChMAc). Assays of cell death, colony formation, mitochondrial bioenergetic function, intracellular ATP levels, intracellular and tissue concentrations of tested compounds, and in vivo tumor growth were performed. Both Mito-ChM and Mito-ChMAc selectively depleted intracellular ATP and caused prolonged inhibition of ATP-linked oxygen consumption rate in breast cancer cells, but not in non-cancerous cells. These effects were significantly augmented by inhibition of glycolysis. Mito-ChM and Mito-ChMAc exhibited anti-proliferative effects and cytotoxicity in several breast cancer cells with different genetic background. Furthermore, Mito-ChM selectively accumulated in tumor tissue and inhibited tumor growth in a xenograft model of human breast cancer. We conclude that mitochondria-targeted small molecular weight chromanols exhibit selective anti-proliferative effects and cytotoxicity in multiple breast cancer cells, and that esterification of the hydroxyl group in mito-chromanols is not a critical requirement for its anti-proliferative and cytotoxic effect

Gene silencing of indoleamine 2,3-dioxygenase 2 in melanoma cells induces apoptosis through the suppression of NAD+ and inhibits in vivo tumor growth.

Science.gov (United States)

Liu, Yanling; Zhang, Yujuan; Zheng, Xiufen; Zhang, Xusheng; Wang, Hongmei; Li, Qin; Yuan, Keng; Zhou, Nanjing; Yu, Yanrong; Song, Na; Fu, Jiamin; Min, Weiping

2016-05-31

Indoleamine 2,3-dioxygenase 2 (IDO2) is a newly discovered enzyme that catalyzes the initial and rate-limiting step in the degradation of tryptophan. As a homologous protein of IDO1, IDO2 plays an inhibitory role in T cell proliferation, and it is essential for regulatory T cell (Treg) generation in healthy conditions. Little is known about the immune-independent functions of IDO2 relevant to its specific contributions to physiology and pathophysiology in cancer cells. The purpose of this study was to assess the impact of IDO2 gene silencing as a way to inhibit B16-BL6 cancer cells in a murine model. Here, for the first time, we show that knockdown of IDO2 using small interfering RNA (siRNA) inhibits cancer cell proliferation, arrests cell cycle in G1, induces greater cell apoptosis, and reduces cell migration in vitro. Knockdown of IDO2 decreased the generation of nicotinamide adenine dinucleotide (NAD+) while increasing the generation of reactive oxygen species (ROS). We further demonstrate that cell apoptosis, induced by IDO2 downregulation, can be weakened by addition of exogenous NAD+, suggesting a novel mechanism by which IDO2 promotes tumor growth through its metabolite product NAD+. In addition to in vitro findings, we also demonstrate that IDO2 silencing in tumor cells using short hairpin RNA (shRNA) delayed tumor formation and arrested tumor growth in vivo. In conclusion, this study demonstrates a new non-immune-associated mechanism of IDO2 in vitro and IDO2 expression in B16-BL6 cells contributes to cancer development and progression. Our research provides evidence of a novel target for gene silencing that has the potential to enhance cancer therapy.

BRAF inhibition is associated with increased clonality in tumor-infiltrating lymphocytes

Science.gov (United States)

Cooper, Zachary A; Frederick, Dennie T; Juneja, Vikram R; Sullivan, Ryan J; Lawrence, Donald P; Piris, Adriano; Sharpe, Arlene H; Fisher, David E; Flaherty, Keith T; Wargo, Jennifer A

2013-01-01

There have been significant advances with regard to BRAF-targeted therapies against metastatic melanoma. However, the majority of patients receiving BRAF inhibitors (BRAFi) manifest disease progression within a year. We have recently shown that melanoma patients treated with BRAFi exhibit an increase in melanoma-associated antigens and in CD8+ tumor-infiltrating lymphocytes in response to therapy. To characterize such a T-cell infiltrate, we analyzed the complementarity-determining region 3 (CDR3) of rearranged T-cell receptor (TCR) β chain-coding genes in tumor biopsies obtained before the initiation of BRAFi and 10–14 d later. We observed an increase in the clonality of tumor-infiltrating lymphocytes in 7 of 8 patients receiving BRAFi, with a statistically significant 21% aggregate increase in clonality. Over 80% of individual T-cell clones detected after initiation of BRAFi treatment were new clones. Interestingly, the comparison of tumor infiltrates with clinical responses revealed that patients who had a high proportion of pre-existing dominant clones after the administration of BRAFi responded better to therapy than patients who had a low proportion of such pre-existing dominant clones following BRAFi. These data suggest that although the inhibition of BRAF in melanoma patients results in tumor infiltration by new lymphocytes, the response to treatment appears to be related to the presence of a pre-existing population of tumor-infiltrating T-cell clones. PMID:24251082

Mesenchymal Stromal Cells Can Regulate the Immune Response in the Tumor Microenvironment

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Alessandro Poggi

2016-11-01

Full Text Available The tumor microenvironment is a good target for therapy in solid tumors and hematological malignancies. Indeed, solid tumor cells’ growth and expansion can influence neighboring cells’ behavior, leading to a modulation of mesenchymal stromal cell (MSC activities and remodeling of extracellular matrix components. This leads to an altered microenvironment, where reparative mechanisms, in the presence of sub-acute inflammation, are not able to reconstitute healthy tissue. Carcinoma cells can undergo epithelial mesenchymal transition (EMT, a key step to generate metastasis; these mesenchymal-like cells display the functional behavior of MSC. Furthermore, MSC can support the survival and growth of leukemic cells within bone marrow participating in the leukemic cell niche. Notably, MSC can inhibit the anti-tumor immune response through either carcinoma-associated fibroblasts or bone marrow stromal cells. Experimental data have indicated their relevance in regulating cytolytic effector lymphocytes of the innate and adaptive arms of the immune system. Herein, we will discuss some of the evidence in hematological malignancies and solid tumors. In particular, we will focus our attention on the means by which it is conceivable to inhibit MSC-mediated immune suppression and trigger anti-tumor innate immunity.

Inhibition of CSF-1R supports T-cell mediated melanoma therapy.

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Marjolein Sluijter

Full Text Available Tumor associated macrophages (TAM can promote angiogenesis, invasiveness and immunosuppression. The cytokine CSF-1 (or M-CSF is an important factor of TAM recruitment and differentiation and several pharmacological agents targeting the CSF-1 receptor (CSF-1R have been developed to regulate TAM in solid cancers. We show that the kinase inhibitor PLX3397 strongly dampened the systemic and local accumulation of macrophages driven by B16F10 melanomas, without affecting Gr-1(+ myeloid derived suppressor cells. Removal of intratumoral macrophages was remarkably efficient and a modest, but statistically significant, delay in melanoma outgrowth was observed. Importantly, CSF-1R inhibition strongly enhanced tumor control by immunotherapy using tumor-specific CD8 T cells. Elevated IFNγ production by T cells was observed in mice treated with the combination of PLX3397 and immunotherapy. These results support the combined use of CSF-1R inhibition with CD8 T cell immunotherapy, especially for macrophage-stimulating tumors.

Inhibiting tumor necrosis factor-alpha diminishes desmoplasia and inflammation to overcome chemoresistance in pancreatic ductal adenocarcinoma.

Science.gov (United States)

Zhao, Xianda; Fan, Wei; Xu, Zhigao; Chen, Honglei; He, Yuyu; Yang, Gui; Yang, Gang; Hu, Hanning; Tang, Shihui; Wang, Ping; Zhang, Zheng; Xu, Peipei; Yu, Mingxia

2016-12-06

Pancreatic ductal adenocarcinoma (PDAC) is one of the most common cancer death reasons. Anti-tumor necrosis factor-alpha (TNF-α) antibodies have shown promising effects in PDAC pre-clinical models. However, the prognostic values of TNF-α, underlying mechanisms by which anti-TNF-α treatments inhibit PDAC, and potential synergistic effects of anti-TNF-α treatments with chemotherapy are still unclear. To identify the targeting values of TNF-α in PDAC, we measured TNF-α expression in different stages of PDAC initiation and evaluated its prognostic significance in a pancreatic cancer cohort. We found that TNF-α expression elevated in PDAC initiation process, and high expression of TNF-α was an independent prognostic marker of poor survival. We further evaluated anti-tumor effects of anti-TNF-α treatments in PDAC. Anti-TNF-α treatments resulted in decreased cell viability in both PDAC tumor cells and pancreatic satellite cells in similar dose in vitro. In vivo, anti-TNF-α treatments showed effects in reducing desmoplasia and the tumor promoting inflammatory microenvironment in PDAC. Combination of anti-TNF-α treatments with chemotherapy partly overcame chemoresistance of PDAC tumor cells and prolonged the survival of PDAC mouse model. In conclusion, our findings indicated that TNF-α in PDAC can be a prognostic and therapeutic target. Inhibition of TNF-α synergized with chemotherapy in PDAC resulted in better pre-clinical responses via killing tumor cells as well as diminishing desmoplasia and inflammation in PDAC tumor stroma.

HER2-Targeted Polyinosine/Polycytosine Therapy Inhibits Tumor Growth and Modulates the Tumor Immune Microenvironment.

Science.gov (United States)

Zigler, Maya; Shir, Alexei; Joubran, Salim; Sagalov, Anna; Klein, Shoshana; Edinger, Nufar; Lau, Jeffrey; Yu, Shang-Fan; Mizraji, Gabriel; Globerson Levin, Anat; Sliwkowski, Mark X; Levitzki, Alexander

2016-08-01

The development of targeted therapies that affect multiple signaling pathways and stimulate antitumor immunity is greatly needed. About 20% of patients with breast cancer overexpress HER2. Small molecules and antibodies targeting HER2 convey some survival benefits; however, patients with advanced disease succumb to the disease under these treatment regimens, possibly because HER2 is not completely necessary for the survival of the targeted cancer cells. In the present study, we show that a polyinosine/polycytosine (pIC) HER2-homing chemical vector induced the demise of HER2-overexpressing breast cancer cells, including trastuzumab-resistant cells. Targeting pIC to the tumor evoked a number of cell-killing mechanisms, as well as strong bystander effects. These bystander mechanisms included type I IFN induction, immune cell recruitment, and activation. The HER2-targeted pIC strongly inhibited the growth of HER2-overexpressing tumors in immunocompetent mice. The data presented here could open additional avenues in the treatment of HER2-positive breast cancer. Cancer Immunol Res; 4(8); 688-97. ©2016 AACR. ©2016 American Association for Cancer Research.

Macrophages inhibit human osteosarcoma cell growth after activation with the bacterial cell wall derivative liposomal muramyl tripeptide in combination with interferon-γ.

Science.gov (United States)

Pahl, Jens H W; Kwappenberg, Kitty M C; Varypataki, Eleni M; Santos, Susy J; Kuijjer, Marieke L; Mohamed, Susan; Wijnen, Juul T; van Tol, Maarten J D; Cleton-Jansen, Anne-Marie; Egeler, R Maarten; Jiskoot, Wim; Lankester, Arjan C; Schilham, Marco W

2014-03-10

In osteosarcoma, the presence of tumor-infiltrating macrophages positively correlates with patient survival in contrast to the negative effect of tumor-associated macrophages in patients with other tumors. Liposome-encapsulated muramyl tripeptide (L-MTP-PE) has been introduced in the treatment of osteosarcoma patients, which may enhance the potential anti-tumor activity of macrophages. Direct anti-tumor activity of human macrophages against human osteosarcoma cells has not been described so far. Hence, we assessed osteosarcoma cell growth after co-culture with human macrophages. Monocyte-derived M1-like and M2-like macrophages were polarized with LPS + IFN-γ, L-MTP-PE +/- IFN-γ or IL-10 and incubated with osteosarcoma cells. Two days later, viable tumor cell numbers were analyzed. Antibody-dependent effects were investigated using the therapeutic anti-EGFR antibody cetuximab. M1-like macrophages inhibited osteosarcoma cell growth when activated with LPS + IFN-γ. Likewise, stimulation of M1-like macrophages with liposomal muramyl tripeptide (L-MTP-PE) inhibited tumor growth, but only when combined with IFN-γ. Addition of the tumor-reactive anti-EGFR antibody cetuximab did not further improve the anti-tumor activity of activated M1-like macrophages. The inhibition was mediated by supernatants of activated M1-like macrophages, containing TNF-α and IL-1β. However, specific blockage of these cytokines, nitric oxide or reactive oxygen species did not inhibit the anti-tumor effect, suggesting the involvement of other soluble factors released upon macrophage activation. While LPS + IFN-γ-activated M2-like macrophages had low anti-tumor activity, IL-10-polarized M2-like macrophages were able to reduce osteosarcoma cell growth in the presence of the anti-EGFR cetuximab involving antibody-dependent tumor cell phagocytosis. This study demonstrates that human macrophages can be induced to exert direct anti-tumor activity against osteosarcoma cells. Our

Activated Macrophages as a Novel Determinant of Tumor Cell Radioresponse: The Role of Nitric Oxide-Mediated Inhibition of Cellular Respiration and Oxygen Sparing

International Nuclear Information System (INIS)

Jiang Heng; De Ridder, Mark; Verovski, Valeri N.; Sonveaux, Pierre; Jordan, Benedicte F.; Law, Kalun; Monsaert, Christinne; Van den Berge, Dirk L.; Verellen, Dirk; Feron, Olivier; Gallez, Bernard; Storme, Guy A.

2010-01-01

Purpose: Nitric oxide (NO), synthesized by the inducible nitric oxide synthase (iNOS), is known to inhibit metabolic oxygen consumption because of interference with mitochondrial respiratory activity. This study examined whether activation of iNOS (a) directly in tumor cells or (b) in bystander macrophages may improve radioresponse through sparing of oxygen. Methods and Materials: EMT-6 tumor cells and RAW 264.7 macrophages were exposed to bacterial lipopolysaccharide plus interferon-γ, and examined for iNOS expression by reverse transcription polymerase chain reaction, Western blotting and enzymatic activity. Tumor cells alone, or combined with macrophages were subjected to metabolic hypoxia and analyzed for radiosensitivity by clonogenic assay, and for oxygen consumption by electron paramagnetic resonance and a Clark-type electrode. Results: Both tumor cells and macrophages displayed a coherent picture of iNOS induction at transcriptional/translational levels and NO/nitrite production, whereas macrophages showed also co-induction of the inducible heme oxygenase-1, which is associated with carbon monoxide (CO) and bilirubin production. Activation of iNOS in tumor cells resulted in a profound oxygen sparing and a 2.3-fold radiosensitization. Bystander NO-producing, but not CO-producing, macrophages were able to block oxygen consumption by 1.9-fold and to radiosensitize tumor cells by 2.2-fold. Both effects could be neutralized by aminoguanidine, a metabolic iNOS inhibitor. An improved radioresponse was clearly observed at macrophages to tumor cells ratios ranging between 1:16 to 1:1. Conclusions: Our study is the first, as far as we are aware, to provide evidence that iNOS may induce radiosensitization through oxygen sparing, and illuminates NO-producing macrophages as a novel determinant of tumor cell radioresponse within the hypoxic tumor microenvironment.

Inhibition of the JAK2/STAT3 pathway in ovarian cancer results in the loss of cancer stem cell-like characteristics and a reduced tumor burden

International Nuclear Information System (INIS)

Abubaker, Khalid; Luwor, Rodney B; Zhu, Hongjian; McNally, Orla; Quinn, Michael A; Burns, Christopher J; Thompson, Erik W; Findlay, Jock K; Ahmed, Nuzhat

2014-01-01

Current treatment of ovarian cancer patients with chemotherapy leaves behind a residual tumor which results in recurrent ovarian cancer within a short time frame. We have previously demonstrated that a single short-term treatment of ovarian cancer cells with chemotherapy in vitro resulted in a cancer stem cell (CSC)-like enriched residual population which generated significantly greater tumor burden compared to the tumor burden generated by control untreated cells. In this report we looked at the mechanisms of the enrichment of CSC-like residual cells in response to paclitaxel treatment. The mechanism of survival of paclitaxel-treated residual cells at a growth inhibitory concentration of 50% (GI50) was determined on isolated tumor cells from the ascites of recurrent ovarian cancer patients and HEY ovarian cancer cell line by in vitro assays and in a mouse xenograft model. Treatment of isolated tumor cells from the ascites of ovarian cancer patients and HEY ovarian cancer cell line with paclitaxel resulted in a CSC-like residual population which coincided with the activation of Janus activated kinase 2 (JAK2) and signal transducer and activation of transcription 3 (STAT3) pathway in paclitaxel surviving cells. Both paclitaxel-induced JAK2/STAT3 activation and CSC-like characteristics were inhibited by a low dose JAK2-specific small molecule inhibitor CYT387 (1 μM) in vitro. Subsequent, in vivo transplantation of paclitaxel and CYT387-treated HEY cells in mice resulted in a significantly reduced tumor burden compared to that seen with paclitaxel only-treated transplanted cells. In vitro analysis of tumor xenografts at protein and mRNA levels demonstrated a loss of CSC-like markers and CA125 expression in paclitaxel and CYT387-treated cell-derived xenografts, compared to paclitaxel only-treated cell-derived xenografts. These results were consistent with significantly reduced activation of JAK2 and STAT3 in paclitaxel and CYT387-treated cell-derived xenografts

Lansoprazole induces apoptosis of breast cancer cells through inhibition of intracellular proton extrusion

Energy Technology Data Exchange (ETDEWEB)

Zhang, Shangrong; Wang, Yifan; Li, Shu Jie, E-mail: shujieli@nankai.edu.cn

2014-06-13

Highlights: • Lansoprazole (LPZ) induces cell apoptosis in breast cancer cells. • LPZ markedly inhibits intracellular proton extrusion. • LPZ induces an increase in intracellular ATP level, lysosomal alkalinization and ROS accumulation. - Abstract: The increased glycolysis and proton secretion in tumors is proposed to contribute to the proliferation and invasion of cancer cells during the process of tumorigenesis and metastasis. Here, treatment of human breast cancer cells with proton pump inhibitor (PPI) lansoprazole (LPZ) induces cell apoptosis in a dose-dependent manner. In the implantation of the MDA-MB-231 xenografts in nude mice, administration of LPZ significantly inhibits tumorigenesis and induces large-scale apopotosis of tumor cells. LPZ markedly inhibits intracellular proton extrusion, induces an increase in intracellular ATP level, lysosomal alkalinization and accumulation of reactive oxygen species (ROS) in breast cancer cells. The ROS scavenger N-acetyl-L-cysteine (NAC) and diphenyleneiodonium (DPI), a specific pharmacological inhibitor of NADPH oxidases (NOX), significantly abolish LPZ-induced ROS accumulation in breast cancer cells. Our results suggested that LPZ may be used as a new therapeutic drug for breast tumor.

Lansoprazole induces apoptosis of breast cancer cells through inhibition of intracellular proton extrusion

International Nuclear Information System (INIS)

Zhang, Shangrong; Wang, Yifan; Li, Shu Jie

2014-01-01

Highlights: • Lansoprazole (LPZ) induces cell apoptosis in breast cancer cells. • LPZ markedly inhibits intracellular proton extrusion. • LPZ induces an increase in intracellular ATP level, lysosomal alkalinization and ROS accumulation. - Abstract: The increased glycolysis and proton secretion in tumors is proposed to contribute to the proliferation and invasion of cancer cells during the process of tumorigenesis and metastasis. Here, treatment of human breast cancer cells with proton pump inhibitor (PPI) lansoprazole (LPZ) induces cell apoptosis in a dose-dependent manner. In the implantation of the MDA-MB-231 xenografts in nude mice, administration of LPZ significantly inhibits tumorigenesis and induces large-scale apopotosis of tumor cells. LPZ markedly inhibits intracellular proton extrusion, induces an increase in intracellular ATP level, lysosomal alkalinization and accumulation of reactive oxygen species (ROS) in breast cancer cells. The ROS scavenger N-acetyl-L-cysteine (NAC) and diphenyleneiodonium (DPI), a specific pharmacological inhibitor of NADPH oxidases (NOX), significantly abolish LPZ-induced ROS accumulation in breast cancer cells. Our results suggested that LPZ may be used as a new therapeutic drug for breast tumor

Specific inhibition of cytotoxic memory cells produced against uv-induced tumors in uv-irradiation mice

International Nuclear Information System (INIS)

Thorn, R.M.

1978-01-01

Cytotoxic responses of uv-irradiated mice against syngeneic uv-induced tumors were measured by using a 51 Cr-release assay to determine if uv treatment induced a specific reduction of cytotoxic activity. The in vivo and in vitro primary responses against syngeneic tumors and allogeneic cells were unaffected, as was the ''memory'' response (in vivo stimulation, in vitro restimulation) against alloantigens. In contrast, the memory response of uv-treated mice against syngeneic, uv-induced tumors was consistently and significantly depressed. The cytotoxicity generated by tumor cell stimulation in vivo or in vitro was tumor-specific and T cell-dependent. Since the primary response against syngeneic uv-induced tumors produces apparently normal amounts of tumor-specific cytotoxic activity, uv-treated mice may not reject transplanted syngeneic tumors because of too few T effector memory cells. These results imply that, at least in this system, tumor rejection depends mostly on the secondary responses against tumor antigens and that at least one carcinogen can, indirectly, specifically regulate immune responses

The downregulation of Mcl-1 via USP9X inhibition sensitizes solid tumors to Bcl-xl inhibition

International Nuclear Information System (INIS)

Peddaboina, Chander; Smythe, W Roy; Cao, Xiaobo; Jupiter, Daniel; Fletcher, Steven; Yap, Jeremy L; Rai, Arun; Tobin, Richard P; Jiang, Weihua; Rascoe, Philip; Rogers, M Karen Newell

2012-01-01

It has been shown in many solid tumors that the overexpression of the pro-survival Bcl-2 family members Bcl-xL and Mcl-1 confers resistance to a variety of chemotherapeutic agents. Mcl-1 is a critical survival protein in a variety of cell lineages and is critically regulated via ubiquitination. The Mcl-1, Bcl-xL and USP9X expression patterns in human lung and colon adenocarcinomas were evaluated via immunohistochemistry. Interaction between USP9X and Mcl-1 was demonstrated by immunoprecipitation-western blotting. The protein expression profiles of Mcl-1, Bcl-xL and USP9X in multiple cancer cell lines were determined by western blotting. Annexin-V staining and cleaved PARP western blotting were used to assay for apoptosis. The cellular toxicities after various treatments were measured via the XTT assay. In our current analysis of colon and lung cancer samples, we demonstrate that Mcl-1 and Bcl-xL are overexpressed and also co-exist in many tumors and that the expression levels of both genes correlate with the clinical staging. The downregulation of Mcl-1 or Bcl-xL via RNAi was found to increase the sensitivity of the tumor cells to chemotherapy. Furthermore, our analyses revealed that USP9X expression correlates with that of Mcl-1 in human cancer tissue samples. We additionally found that the USP9X inhibitor WP1130 promotes Mcl-1 degradation and increases tumor cell sensitivity to chemotherapies. Moreover, the combination of WP1130 and ABT-737, a well-documented Bcl-xL inhibitor, demonstrated a chemotherapeutic synergy and promoted apoptosis in different tumor cells. Mcl-1, Bcl-xL and USP9X overexpression are tumor survival mechanisms protective against chemotherapy. USP9X inhibition increases tumor cell sensitivity to various chemotherapeutic agents including Bcl-2/Bcl-xL inhibitors

Changes in proteasome structure and function caused by HAMLET in tumor cells.

Science.gov (United States)

Gustafsson, Lotta; Aits, Sonja; Onnerfjord, Patrik; Trulsson, Maria; Storm, Petter; Svanborg, Catharina

2009-01-01

Proteasomes control the level of endogenous unfolded proteins by degrading them in the proteolytic core. Insufficient degradation due to altered protein structure or proteasome inhibition may trigger cell death. This study examined the proteasome response to HAMLET, a partially unfolded protein-lipid complex, which is internalized by tumor cells and triggers cell death. HAMLET bound directly to isolated 20S proteasomes in vitro and in tumor cells significant co-localization of HAMLET and 20S proteasomes was detected by confocal microscopy. This interaction was confirmed by co-immunoprecipitation from extracts of HAMLET-treated tumor cells. HAMLET resisted in vitro degradation by proteasomal enzymes and degradation by intact 20S proteasomes was slow compared to fatty acid-free, partially unfolded alpha-lactalbumin. After a brief activation, HAMLET inhibited proteasome activity in vitro and in parallel a change in proteasome structure occurred, with modifications of catalytic (beta1 and beta5) and structural subunits (alpha2, alpha3, alpha6 and beta3). Proteasome inhibition was confirmed in extracts from HAMLET-treated cells and there were indications of proteasome fragmentation in HAMLET-treated cells. The results suggest that internalized HAMLET is targeted to 20S proteasomes, that the complex resists degradation, inhibits proteasome activity and perturbs proteasome structure. We speculate that perturbations of proteasome structure might contribute to the cytotoxic effects of unfolded protein complexes that invade host cells.

Inhibition of Tumor Angiogenesis and Tumor Growth by the DSL Domain of Human Delta-Like 1 Targeted to Vascular Endothelial Cells12

OpenAIRE

Zhao, Xing-Cheng; Dou, Guo-Rui; Wang, Li; Liang, Liang; Tian, Deng-Mei; Cao, Xiu-Li; Qin, Hong-Yan; Wang, Chun-Mei; Zhang, Ping; Han, Hua

2013-01-01

The growth of solid tumors depends on neovascularization. Several therapies targeting tumor angiogenesis have been developed. However, poor response in some tumors and emerging resistance necessitate further investigations of new drug targets. Notch signal pathway plays a pivotal role in vascular development and tumor angiogenesis. Either blockade or forced activation of this pathway can inhibit angiogenesis. As blocking Notch pathway results in the formation of vascular neoplasm, activation ...

pH-dependent antitumor activity of proton pump inhibitors against human melanoma is mediated by inhibition of tumor acidity.

Science.gov (United States)

De Milito, Angelo; Canese, Rossella; Marino, Maria Lucia; Borghi, Martina; Iero, Manuela; Villa, Antonello; Venturi, Giulietta; Lozupone, Francesco; Iessi, Elisabetta; Logozzi, Mariantonia; Della Mina, Pamela; Santinami, Mario; Rodolfo, Monica; Podo, Franca; Rivoltini, Licia; Fais, Stefano

2010-07-01

Metastatic melanoma is associated with poor prognosis and still limited therapeutic options. An innovative treatment approach for this disease is represented by targeting acidosis, a feature characterizing tumor microenvironment and playing an important role in cancer malignancy. Proton pump inhibitors (PPI), such as esomeprazole (ESOM) are prodrugs functionally activated by acidic environment, fostering pH neutralization by inhibiting proton extrusion. We used human melanoma cell lines and xeno-transplated SCID mice to provide preclinical evidence of ESOM antineoplastic activity. Human melanoma cell lines, characterized by different mutation and signaling profiles, were treated with ESOM in different pH conditions and evaluated for proliferation, viability and cell death. SCID mice engrafted with human melanoma were used to study ESOM administration effects on tumor growth and tumor pH by magnetic resonance spectroscopy (MRS). ESOM inhibited proliferation of melanoma cells in vitro and induced a cytotoxicity strongly boosted by low pH culture conditions. ESOM-induced tumor cell death occurred via rapid intracellular acidification and activation of several caspases. Inhibition of caspases activity by pan-caspase inhibitor z-vad-fmk completely abrogated the ESOM-induced cell death. ESOM administration (2.5 mg kg(-1)) to SCID mice engrafted with human melanoma reduced tumor growth, consistent with decrease of proliferating cells and clear reduction of pH gradients in tumor tissue. Moreover, systemic ESOM administration dramatically increased survival of human melanoma-bearing animals, in absence of any relevant toxicity. These data show preclinical evidence supporting the use of PPI as novel therapeutic strategy for melanoma, providing the proof of concept that PPI target human melanoma modifying tumor pH gradients.

Regorafenib inhibited gastric cancer cells growth and invasion via CXCR4 activated Wnt pathway.

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Lin, Xiao-Lin; Xu, Qi; Tang, Lei; Sun, Li; Han, Ting; Wang, Li-Wei; Xiao, Xiu-Ying

2017-01-01

Regorafenib is an oral small-molecule multi kinase inhibitor. Recently, several clinical trials have revealed that regorafenib has an anti-tumor activity in gastric cancer. However, only part of patients benefit from regorafenib, and the mechanisms of regorafenib's anti-tumor effect need further demonstrating. In this study, we would assess the potential anti-tumor effects and the underlying mechanisms of regorafenib in gastric cancer cells, and explore novel biomarkers for patients selecting of regorafenib. The anti-tumor effects of regorafenib on gastric cancer cells were analyzed via cell proliferation and invasion. The underlying mechanisms were demonstrated using molecular biology techniques. We found that regorafenib inhibited cell proliferation and invasion at the concentration of 20μmol/L and in a dose dependent manner. The anti-tumor effects of regorafenib related to the decreased expression of CXCR4, and elevated expression and activation of CXCR4 could reverse the inhibition effect of regorafenib on gastric cancer cells. Further studies revealed that regorafenib reduced the transcriptional activity of Wnt/β-Catenin pathway and led to decreased expression of Wnt pathway target genes, while overexpression and activation of CXCR4 could attenuate the inhibition effect of regorafenib on Wnt/β-Catenin pathway. Our findings demonstrated that regorafenib effectively inhibited cell proliferation and invasion of gastric cancer cells via decreasing the expression of CXCR4 and further reducing the transcriptional activity of Wnt/β-Catenin pathway.

PPARα inhibition modulates multiple reprogrammed metabolic pathways in kidney cancer and attenuates tumor growth.

Science.gov (United States)

Abu Aboud, Omran; Donohoe, Dallas; Bultman, Scott; Fitch, Mark; Riiff, Tim; Hellerstein, Marc; Weiss, Robert H

2015-06-01

Kidney cancer [renal cell carcinoma (RCC)] is the sixth-most-common cancer in the United States, and its incidence is increasing. The current progression-free survival for patients with advanced RCC rarely extends beyond 1-2 yr due to the development of therapeutic resistance. We previously identified peroxisome proliferator-activating receptor-α (PPARα) as a potential therapeutic target for this disease and showed that a specific PPARα antagonist, GW6471, induced apoptosis and cell cycle arrest at G0/G1 in RCC cell lines associated with attenuation of cell cycle regulatory proteins. We now extend that work and show that PPARα inhibition attenuates components of RCC metabolic reprogramming, capitalizing on the Warburg effect. The specific PPARα inhibitor GW6471, as well as a siRNA specific to PPARα, attenuates the enhanced fatty acid oxidation and oxidative phosphorylation associated with glycolysis inhibition, and PPARα antagonism also blocks the enhanced glycolysis that has been observed in RCC cells; this effect did not occur in normal human kidney epithelial cells. Such cell type-specific inhibition of glycolysis corresponds with changes in protein levels of the oncogene c-Myc and has promising clinical implications. Furthermore, we show that treatment with GW6471 results in RCC tumor growth attenuation in a xenograft mouse model, with minimal obvious toxicity, a finding associated with the expected on-target effects on c-Myc. These studies demonstrate that several pivotal cancer-relevant metabolic pathways are inhibited by PPARα antagonism. Our data support the concept that targeting PPARα, with or without concurrent inhibition of glycolysis, is a potential novel and effective therapeutic approach for RCC that targets metabolic reprogramming in this tumor.

Enhancement of hypoxia-activated prodrug TH-302 anti-tumor activity by Chk1 inhibition.

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Meng, Fanying; Bhupathi, Deepthi; Sun, Jessica D; Liu, Qian; Ahluwalia, Dharmendra; Wang, Yan; Matteucci, Mark D; Hart, Charles P

2015-05-21

The hypoxia-activated prodrug TH-302 is reduced at its nitroimidazole group and selectively under hypoxic conditions releases the DNA cross-linker bromo-isophosphoramide mustard (Br-IPM). Here, we have explored the effect of Chk1 inhibition on TH-302-mediated pharmacological activities. We employed in vitro cell viability, DNA damage, cellular signaling assays and the in vivo HT29 human tumor xenograft model to study the effect of Chk1inhibition on TH-302 antitumor activities. TH-302 cytotoxicity is greatly enhanced by Chk1 inhibition in p53-deficient but not in p53-proficient human cancer cell lines. Chk1 inhibitors reduced TH-302-induced cell cycle arrest via blocking TH-302-induced decrease of phosphorylation of histone H3 and increasing Cdc2-Y15 phosphorylation. Employing the single-cell gel electrophoresis (comet) assay, we observed a potentiation of the TH-302 dependent tail moment. TH-302 induced γH2AX and apoptosis were also increased upon the addition of Chk1 inhibitor. Potentiation of TH-302 cytotoxicity by Chk1 inhibitor was only observed in cell lines proficient in, but not deficient in homology-directed DNA repair. We also show that combination treatment led to lowering of Rad51 expression levels as compared to either agent alone. In vivo data demonstrate that Chk1 inhibitor enhances TH-302 anti-tumor activity in p53 mutant HT-29 human tumor xenografts, supporting the hypothesis that these in vitro results can translate to enhanced in vivo efficacy of the combination. TH-302-mediated in vitro and in vivo anti-tumor activities were greatly enhanced by the addition of Chk1 inhibitors. The preclinical data presented in this study support a new approach for the treatment of p53-deficient hypoxic cancers by combining Chk1 inhibitors with the hypoxia-activated prodrug TH-302.

CD200-expressing human basal cell carcinoma cells initiate tumor growth.

Science.gov (United States)

Colmont, Chantal S; Benketah, Antisar; Reed, Simon H; Hawk, Nga V; Telford, William G; Ohyama, Manabu; Udey, Mark C; Yee, Carole L; Vogel, Jonathan C; Patel, Girish K

2013-01-22

Smoothened antagonists directly target the genetic basis of human basal cell carcinoma (BCC), the most common of all cancers. These drugs inhibit BCC growth, but they are not curative. Although BCC cells are monomorphic, immunofluorescence microscopy reveals a complex hierarchical pattern of growth with inward differentiation along hair follicle lineages. Most BCC cells express the transcription factor KLF4 and are committed to terminal differentiation. A small CD200(+) CD45(-) BCC subpopulation that represents 1.63 ± 1.11% of all BCC cells resides in small clusters at the tumor periphery. By using reproducible in vivo xenograft growth assays, we determined that tumor initiating cell frequencies approximate one per 1.5 million unsorted BCC cells. The CD200(+) CD45(-) BCC subpopulation recreated BCC tumor growth in vivo with typical histological architecture and expression of sonic hedgehog-regulated genes. Reproducible in vivo BCC growth was achieved with as few as 10,000 CD200(+) CD45(-) cells, representing ~1,500-fold enrichment. CD200(-) CD45(-) BCC cells were unable to form tumors. These findings establish a platform to study the effects of Smoothened antagonists on BCC tumor initiating cell and also suggest that currently available anti-CD200 therapy be considered, either as monotherapy or an adjunct to Smoothened antagonists, in the treatment of inoperable BCC.

Validating the pivotal role of the immune system in low-dose radiation-induced tumor inhibition in Lewis lung cancer-bearing mice.

Science.gov (United States)

Zhou, Lei; Zhang, Xiaoying; Li, Hui; Niu, Chao; Yu, Dehai; Yang, Guozi; Liang, Xinyue; Wen, Xue; Li, Min; Cui, Jiuwei

2018-04-01

Although low-dose radiation (LDR) possesses the two distinct functions of inducing hormesis and adaptive responses, which result in immune enhancement and tumor inhibition, its clinical applications have not yet been elucidated. The major obstacle that hinders the application of LDR in the clinical setting is that the mechanisms underlying induction of tumor inhibition are unclear, and the risks associated with LDR are still unknown. Thus, to overcome this obstacle and elucidate the mechanisms mediating the antitumor effects of LDR, in this study, we established an in vivo lung cancer model to investigate the participation of the immune system in LDR-induced tumor inhibition and validated the pivotal role of the immune system by impairing immunity with high-dose radiation (HDR) of 1 Gy. Additionally, the LDR-induced adaptive response of the immune system was also observed by sequential HDR treatment in this mouse model. We found that LDR-activated T cells and natural killer cells and increased the cytotoxicity of splenocytes and the infiltration of T cells in the tumor tissues. In contrast, when immune function was impaired by HDR pretreatment, LDR could not induce tumor inhibition. However, when LDR was administered before HDR, the immunity could be protected from impairment, and tumor growth could be inhibited to some extent, indicating the induction of the immune adaptive response by LDR. Therefore, we demonstrated that immune enhancement played a key role in LDR-induced tumor inhibition. These findings emphasized the importance of the immune response in tumor radiotherapy and may help promote the application of LDR as a novel approach in clinical practice. © 2018 The Authors. Cancer Medicine published by John Wiley & Sons Ltd.

Radiosensitization of normoxic and hypoxic h1339 lung tumor cells by heat shock protein 90 inhibition is independent of hypoxia inducible factor-1α.

Science.gov (United States)

Schilling, Daniela; Bayer, Christine; Li, Wei; Molls, Michael; Vaupel, Peter; Multhoff, Gabriele

2012-01-01

Ionizing irradiation is a commonly accepted treatment modality for lung cancer patients. However, the clinical outcome is hampered by normal tissue toxicity and tumor hypoxia. Since tumors often have higher levels of active heat shock protein 90 (Hsp90) than normal tissues, targeting of Hsp90 might provide a promising strategy to sensitize tumors towards irradiation. Hsp90 client proteins include oncogenic signaling proteins, cell cycle activators, growth factor receptors and hypoxia inducible factor-1α (HIF-1α). Overexpression of HIF-1α is assumed to promote malignant transformation and tumor progression and thus might reduce the accessibility to radiotherapy. Herein, we describe the effects of the novel Hsp90 inhibitor NVP-AUY922 and 17-allylamino-17-demethoxygeldanamycin (17-AAG), as a control, on HIF-1α levels and radiosensitivity of lung carcinoma cells under normoxic and hypoxic conditions. NVP-AUY922 exhibited a similar biological activity to that of 17-AAG, but at only 1/10 of the dose. As expected, both inhibitors reduced basal and hypoxia-induced HIF-1α levels in EPLC-272H lung carcinoma cells. However, despite a down-regulation of HIF-1α upon Hsp90 inhibition, sensitivity towards irradiation remained unaltered in EPLC-272H cells under normoxic and hypoxic conditions. In contrast, treatment of H1339 lung carcinoma cells with NVP-AUY922 and 17-AAG resulted in a significant up-regulation of their initially high HIF-1α levels and a concomitant increase in radiosensitivity. In summary, our data show a HIF-1α-independent radiosensitization of normoxic and hypoxic H1339 lung cancer cells by Hsp90 inhibition.

Radiosensitization of NSCLC cells by EGFR inhibition is the result of an enhanced p53-dependent G1 arrest

International Nuclear Information System (INIS)

Kriegs, Malte; Gurtner, Kristin; Can, Yildiz; Brammer, Ingo; Rieckmann, Thorsten; Oertel, Reinhard; Wysocki, Marek; Dorniok, Franziska; Gal, Andreas; Grob, Tobias J.; Laban, Simon; Kasten-Pisula, Ulla; Petersen, Cordula; Baumann, Michael; Krause, Mechthild; Dikomey, Ekkehard

2015-01-01

Purpose: How EGF receptor (EGFR) inhibition induces cellular radiosensitization and with that increase in tumor control is still a matter of discussion. Since EGFR predominantly regulates cell cycle and proliferation, we studied whether a G1-arrest caused by EGFR inhibition may contribute to these effects. Materials and methods: We analyzed human non-small cell lung cancer (NSCLC) cell lines either wild type (wt) or mutated in p53 (A549, H460, vs. H1299, H3122) and HCT116 cells (p21 wt and negative). EGFR was inhibited by BIBX1382BS, erlotinib or cetuximab; p21 was knocked down by siRNA. Functional endpoints analyzed were cell signaling, proliferation, G1-arrest, cell survival as well as tumor control using an A549 tumor model. Results: When combined with IR, EGFR inhibition enhances the radiation-induced permanent G1 arrest, though solely in cells with intact p53/p21 signaling. This increase in G1-arrest was always associated with enhanced cellular radiosensitivity. Strikingly, this effect was abrogated when cells were re-stimulated, suggesting the initiation of dormancy. In line with this, only a small non-significant increase in tumor control was observed for A549 tumors treated with fractionated RT and EGFR inhibition. Conclusion: For NSCLC cells increase in radiosensitivity by EGFR inhibition results from enhanced G1-arrest. However, this effect does not lead to improved tumor control because cells can be released from this arrest by re-stimulation

Inhibition of prostate cancer osteoblastic progression with VEGF121/rGel, a single agent targeting osteoblasts, osteoclasts, and tumor neovasculature

Science.gov (United States)

Mohamedali, Khalid A.; Li, Zhi Gang; Starbuck, Michael W.; Wan, Xinhai; Yang, Jun; Kim, Sehoon; Zhang, Wendy; Rosenblum, Michael G.; Navone, Nora M.

2011-01-01

Purpose A hallmark of prostate cancer (PCa) progression is the development of osteoblastic bone metastases, which respond poorly to available therapies. We previously reported that VEGF121/rGel targets osteoclast precursors and tumor neovasculature. Here we tested the hypothesis that targeting non-tumor cells expressing these receptors can inhibit tumor progression in a clinically relevant model of osteoblastic PCa. Experimental Design Cells from MDA PCa 118b, a PCa xenograft obtained from a bone metastasis in a patient with castrate-resistant PCa, were injected into the femurs of mice. Osteoblastic progression was monitored following systemic administration of VEGF121/rGel. Results VEGF121/rGel was cytotoxic in vitro to osteoblast precursor cells. This cytotoxicity was specific as VEGF121/rGel internalization into osteoblasts was VEGF121 receptor driven. Furthermore, VEGF121/rGel significantly inhibited PCa-induced bone formation in a mouse calvaria culture assay. In vivo, VEGF121/rGel significantly inhibited the osteoblastic progression of PCa cells in the femurs of nude mice. Microcomputed tomography analysis revealed that VEGF121/rGel restored the bone volume fraction of tumor-bearing femurs to values similar to those of the contralateral (non–tumor bearing) femurs. VEGF121/rGel significantly reduced the number of tumor-associated osteoclasts but did not change the numbers of peritumoral osteoblasts. Importantly, VEGF121/rGel-treated mice had significantly less tumor burden than control mice. Our results thus indicate that VEGF121/rGel inhibits osteoblastic tumor progression by targeting angiogenesis, osteoclastogenesis, and bone formation. Conclusions Targeting VEGFR-1 – or VEGFR-2–expressing cells is effective in controlling the osteoblastic progression of PCa in bone. These findings provide the basis for an effective multitargeted approach for metastatic PCa. PMID:21343372

Zoledronic acid inhibits pulmonary metastasis dissemination in a preclinical model of Ewing’s sarcoma via inhibition of cell migration

International Nuclear Information System (INIS)

Odri, Guillaume; Kim, Pui-Pui; Lamoureux, François; Charrier, Céline; Battaglia, Séverine; Amiaud, Jérôme; Heymann, Dominique; Gouin, François; Redini, Françoise

2014-01-01

Ewing’s sarcoma (ES) is the second most frequent primitive malignant bone tumor in adolescents with a very poor prognosis for high risk patients, mainly when lung metastases are detected (overall survival <15% at 5 years). Zoledronic acid (ZA) is a potent inhibitor of bone resorption which induces osteoclast apoptosis. Our previous studies showed a strong therapeutic potential of ZA as it inhibits ES cell growth in vitro and ES primary tumor growth in vivo in a mouse model developed in bone site. However, no data are available on lung metastasis. Therefore, the aim of this study was to determine the effect of ZA on ES cell invasion and metastatic properties. Invasion assays were performed in vitro in Boyden’s chambers covered with Matrigel. Matrix Metalloproteinase (MMP) activity was analyzed by zymography in ES cell culture supernatant. In vivo, a relevant model of spontaneous lung metastases which disseminate from primary ES tumor was induced by the orthotopic injection of 10 6 human ES cells in the tibia medullar cavity of nude mice. The effect of ZA (50 μg/kg, 3x/week) was studied over a 4-week period. Lung metastases were observed macroscopically at autopsy and analysed by histology. ZA induced a strong inhibition of ES cell invasion, probably due to down regulation of MMP-2 and −9 activities as analyzed by zymography. In vivo, ZA inhibits the dissemination of spontaneous lung metastases from a primary ES tumor but had no effect on the growth of established lung metastases. These results suggest that ZA could be used early in the treatment of ES to inhibit bone tumor growth but also to prevent the early metastatic events to the lungs

The role of tumor cell-derived connective tissue growth factor (CTGF/CCN2) in pancreatic tumor growth.

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Bennewith, Kevin L; Huang, Xin; Ham, Christine M; Graves, Edward E; Erler, Janine T; Kambham, Neeraja; Feazell, Jonathan; Yang, George P; Koong, Albert; Giaccia, Amato J

2009-02-01

Pancreatic cancer is highly aggressive and refractory to existing therapies. Connective tissue growth factor (CTGF/CCN2) is a fibrosis-related gene that is thought to play a role in pancreatic tumor progression. However, CCN2 can be expressed in a variety of cell types, and the contribution of CCN2 derived from either tumor cells or stromal cells as it affects the growth of pancreatic tumors is unknown. Using genetic inhibition of CCN2, we have discovered that CCN2 derived from tumor cells is a critical regulator of pancreatic tumor growth. Pancreatic tumor cells derived from CCN2 shRNA-expressing clones showed dramatically reduced growth in soft agar and when implanted s.c. We also observed a role for CCN2 in the growth of pancreatic tumors implanted orthotopically, with tumor volume measurements obtained by positron emission tomography imaging. Mechanistically, CCN2 protects cells from hypoxia-mediated apoptosis, providing an in vivo selection for tumor cells that express high levels of CCN2. We found that CCN2 expression and secretion was increased in hypoxic pancreatic tumor cells in vitro, and we observed colocalization of CCN2 and hypoxia in pancreatic tumor xenografts and clinical pancreatic adenocarcinomas. Furthermore, we found increased CCN2 staining in clinical pancreatic tumor tissue relative to stromal cells surrounding the tumor, supporting our assertion that tumor cell-derived CCN2 is important for pancreatic tumor growth. Taken together, these data improve our understanding of the mechanisms responsible for pancreatic tumor growth and progression, and also indicate that CCN2 produced by tumor cells represents a viable therapeutic target for the treatment of pancreatic cancer.

Targeting receptor for advanced glycation end products (RAGE) expression induces apoptosis and inhibits prostate tumor growth

International Nuclear Information System (INIS)

Elangovan, Indira; Thirugnanam, Sivasakthivel; Chen, Aoshuang; Zheng, Guoxing; Bosland, Maarten C.; Kajdacsy-Balla, André; Gnanasekar, Munirathinam

2012-01-01

Highlights: ► Targeting RAGE by RNAi induces apoptosis in prostate cancer cells. ► Silencing RAGE expression abrogates rHMGB1 mediated cell proliferation. ► Down regulation of RAGE by RNAi inhibits PSA secretion of prostate cancer cells. ► Knock down of RAGE abrogates prostate tumor growth in vivo. ► Disruption of RAGE expression in prostate tumor activates death receptors. -- Abstract: Expression of receptor for advanced glycation end products (RAGE) plays a key role in the progression of prostate cancer. However, the therapeutic potential of targeting RAGE expression in prostate cancer is not yet evaluated. Therefore in this study, we have investigated the effects of silencing the expression of RAGE by RNAi approach both in vitro and in vivo. The results of this study showed that down regulation of RAGE expression by RNAi inhibited the cell proliferation of androgen-dependent (LNCaP) and androgen-independent (DU-145) prostate cancer cells. Furthermore, targeting RAGE expression resulted in apoptotic elimination of these prostate cancer cells by activation of caspase-8 and caspase-3 death signaling. Of note, the levels of prostate specific antigen (PSA) were also reduced in LNCaP cells transfected with RAGE RNAi constructs. Importantly, the RAGE RNAi constructs when administered in nude mice bearing prostate tumors, inhibited the tumor growth by targeting the expression of RAGE, and its physiological ligand, HMGB1 and by up regulating death receptors DR4 and DR5 expression. Collectively, the results of this study for the first time show that targeting RAGE by RNAi may be a promising alternative therapeutic strategy for treating prostate cancer.

Total Alkaloids of Sophora alopecuroides Inhibit Growth and Induce Apoptosis in Human Cervical Tumor HeLa Cells In vitro.

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Li, Jian-Guang; Yang, Xiao-Yi; Huang, Wei

2016-05-01

Uygur females of Xinjiang have the higher incidence of cervical tumor in the country. Alkaloids are the major active ingredients in Sophora alopecuroides, and its antitumor effect was recognized by the medical profession. Xinjiang is the main site of S. alopecuroides production in China so these plants are abundant in the region. Studies on the antitumor properties of total alkaloids of S. alopecuroides (TASA) can take full use of the traditional folk medicine in antitumor unique utility. To explore the effects of TASA on proliferation and apoptosis of human cervical tumor HeLa cells in vitro. TASA was extracted, purified, and each monomer component was analyzed by high-performance liquid chromatography. The effect of TASA at different concentrations on the survival of HeLa cells was determined after 24 h using the Cell Counting Kit-8. In addition, cells were photographed using an inverted microscope to document morphological changes. The effect of TASA on apoptotic rate of HeLa cells was assessed by flow cytometry. Monomers of TASA were found to be sophoridine, matrine, and sophocarpine. On treatment with 8.75 mg/ml of TASA, more than 50% of HeLa cells died, and cell death rate increased further with longer incubation. The apoptotic rates of HeLa cells in the experimental groups were 16.0% and 33.3% at concentrations of 6.25 mg/ml and 12.50 mg/ml, respectively. TASA can induce apoptosis in cervical tumor HeLa cells, and it has obvious inhibitory effects on cell growth. Total alkaloids of Sophora alopecuroides (TASA) exhibits anti-human cervical tumor propertiesMonomer component of TASA was analyzed by high-performance liquid chromatography, and its main effect component are sophoridine, matrine, and sophocarpineTASA inhibits growth and induces apoptosis in HeLa cells. Abbreviations used: TASA: Total alkaloids of S. alopecuroides, CCK-8: Cell Counting Kit-8, FBS: Fetal bovine serum, PBS: Phosphate buffered saline, DMEM: Dulbecco's modified Eagle medium.

Improving immunological tumor microenvironment using electro-hyperthermia followed by dendritic cell immunotherapy.

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Tsang, Yuk-Wah; Huang, Cheng-Chung; Yang, Kai-Lin; Chi, Mau-Shin; Chiang, Hsin-Chien; Wang, Yu-Shan; Andocs, Gabor; Szasz, Andras; Li, Wen-Tyng; Chi, Kwan-Hwa

2015-10-15

The treatment of intratumoral dentritic cells (DCs) commonly fails because it cannot evoke immunity in a poor tumor microenvironment (TME). Modulated electro-hyperthermia (mEHT, trade-name: oncothermia) represents a significant technological advancement in the hyperthermia field, allowing the autofocusing of electromagnetic power on a cell membrane to generate massive apoptosis. This approach turns local immunogenic cancer cell death (apoptosis) into a systemic anti-tumor immune response and may be implemented by treatment with intratumoral DCs. The CT26 murine colorectal cancer model was used in this investigation. The inhibition of growth of the tumor and the systemic anti-tumor immune response were measured. The tumor was heated to a core temperature of 42 °C for 30 min. The matured synergetic DCs were intratumorally injected 24 h following mEHT was applied. mEHT induced significant apoptosis and enhanced the release of heat shock protein70 (Hsp70) in CT26 tumors. Treatment with mEHT-DCs significantly inhibited CT26 tumor growth, relative to DCs alone or mEHT alone. The secondary tumor protection effect upon rechallenging was observed in mice that were treated with mEHT-DCs. Immunohistochemical staining of CD45 and F4/80 revealed that mEHT-DC treatment increased the number of leukocytes and macrophages. Most interestingly, mEHT also induced infiltrations of eosinophil, which has recently been reported to be an orchestrator of a specific T cell response. Cytotoxic T cell assay and ELISpot assay revealed a tumor-specific T cell activity. This study demonstrated that mEHT induces tumor cell apoptosis and enhances the release of Hsp70 from heated tumor cells, unlike conventional hyperthermia. mEHT can create a favorable tumor microenvironment for an immunological chain reaction that improves the success rate of intratumoral DC immunotherapy.

Inhibition of metastasis, angiogenesis, and tumor growth by Chinese herbal cocktail Tien-Hsien Liquid

International Nuclear Information System (INIS)

Chia, Jean-San; Du, Jia-Ling; Hsu, Wei-Bin; Sun, Andy; Chiang, Chun-Pin; Wang, Won-Bo

2010-01-01

Advanced cancer is a multifactorial disease that demands treatments targeting multiple cellular pathways. Chinese herbal cocktail which contains various phytochemicals may target multiple dys-regulated pathways in cancer cells and thus may provide an alternative/complementary way to treat cancers. Previously we reported that the Chinese herbal cocktail Tien-Hsien Liguid (THL) can specifically induce apoptosis in various cancer cells and have immuno-modulating activity. In this study, we further evaluated the anti-metastatic, anti-angiogenic and anti-tumor activities of THL with a series of in vitro and in vivo experiments. The migration and invasion of cancer cells and endothelial cells was determined by Boyden chamber transwell assays. The effect of THL on pulmonary metastasis was done by injecting CT-26 colon cancer cells intravenously to syngenic mice. The in vitro and in vivo microvessel formation was determined by the tube formation assay and the Matrigel plug assay, respectively. The in vivo anti-tumor effect of THL was determined by a human MDA-MB-231 breast cancer xenograft model. The expression of metalloproteinase (MMP)-2, MMP-9, and urokinase plasminogen activator (uPA) was measured by gelatin zymography. The expression of HIF-1α and the phosphorylation of ERK1/2 were determined by Western blot. THL inhibited the migration and invasion ability of various cancer cells in vitro, decreased the secretion of MMP-2, MMP-9, and uPA and the activity of ERK1/2 in cancer cells, and suppressed pulmonary metastasis of CT-26 cancer cells in syngenic mice. Moreover, THL inhibited the migration, invasion, and tube formation of endothelial cells in vitro, decreased the secretion of MMP-2 and uPA in endothelial cells, and suppressed neovascularization in Matrigel plugs in mice. Besides its inhibitory effect on endothelial cells, THL inhibited hypoxia-induced HIF-1α and vascular endothelial growth factor-A expression in cancer cells. Finally, our results show that THL

FOXD3 suppresses tumor growth and angiogenesis in non-small cell lung cancer

International Nuclear Information System (INIS)

Yan, Jun-Hai; Zhao, Chun-Liu; Ding, Lan-Bao; Zhou, Xi

2015-01-01

The transcription factor forkhead box D3 (FOXD3), widely studied as a transcriptional repressor in embryogenesis, participates in the carcinogenesis of many cancers. However, the expression pattern and role of FOXD3 in non-small cell lung cancer (NSCLC) have not been well characterized. We report that FOXD3 is significantly downregulated in NSCLC cell lines and clinical tissues. FOXD3 overexpression significantly inhibits cell growth and results in G1 cell cycle arrest in NSCLC A549 and H1299 cells. In a xenograft tumor model, FOXD3 overexpression inhibits tumor growth and angiogenesis. Remarkably, expression of vascular endothelial growth factor (VEGF) was reduced in FOXD3 overexpression models both in vitro and in vivo. These findings suggest that FOXD3 plays a potential tumor suppressor role in NSCLC progression and represents a promising clinical prognostic marker and therapeutic target for this disease. - Highlights: • FOXD3 is downregulated in NSCLC cell lines and tissues. • FOXD3 overexpression inhibited cell proliferation in NSCLC cells. • FOXD3 overexpression led to decreased angiogenesis in NSCLC cells in vitro and in vivo.

FOXD3 suppresses tumor growth and angiogenesis in non-small cell lung cancer

Energy Technology Data Exchange (ETDEWEB)

Yan, Jun-Hai; Zhao, Chun-Liu [Department of Respiratory Medicine, Luwan Branch of Ruijin Hospital, Shanghai Jiaotong University School of Medicine, Shanghai 20020 (China); Ding, Lan-Bao [Department of Nuclear Medicine, Shanghai 10th People' s Hospital, Tongji University School of Medicine, Shanghai 200072 (China); Zhou, Xi, E-mail: modelmap@139.com [Department of Respiratory Medicine, Luwan Branch of Ruijin Hospital, Shanghai Jiaotong University School of Medicine, Shanghai 20020 (China)

2015-10-09

The transcription factor forkhead box D3 (FOXD3), widely studied as a transcriptional repressor in embryogenesis, participates in the carcinogenesis of many cancers. However, the expression pattern and role of FOXD3 in non-small cell lung cancer (NSCLC) have not been well characterized. We report that FOXD3 is significantly downregulated in NSCLC cell lines and clinical tissues. FOXD3 overexpression significantly inhibits cell growth and results in G1 cell cycle arrest in NSCLC A549 and H1299 cells. In a xenograft tumor model, FOXD3 overexpression inhibits tumor growth and angiogenesis. Remarkably, expression of vascular endothelial growth factor (VEGF) was reduced in FOXD3 overexpression models both in vitro and in vivo. These findings suggest that FOXD3 plays a potential tumor suppressor role in NSCLC progression and represents a promising clinical prognostic marker and therapeutic target for this disease. - Highlights: • FOXD3 is downregulated in NSCLC cell lines and tissues. • FOXD3 overexpression inhibited cell proliferation in NSCLC cells. • FOXD3 overexpression led to decreased angiogenesis in NSCLC cells in vitro and in vivo.

TLR4 plays a crucial role in MSC-induced inhibition of NK cell function

Energy Technology Data Exchange (ETDEWEB)

Lu, Ying [No. 307 Hospital of the Chinese People' s Liberation Army, Beijing (China); Liu, Jin; Liu, Yang; Qin, Yaru [Beijing Institute of Radiation Medicine, Beijing (China); Luo, Qun [No. 307 Hospital of the Chinese People' s Liberation Army, Beijing (China); Wang, Quanli, E-mail: 13691110351@163.com [No. 307 Hospital of the Chinese People' s Liberation Army, Beijing (China); Duan, Haifeng, E-mail: duanhf0720@163.com [Beijing Institute of Radiation Medicine, Beijing (China)

2015-08-21

Mesenchymal stem cells (MSC) are a kind of stromal cell within the tumor microenvironment. In our research, MSC derived from acute myeloid leukemia patients' bone marrow (AML-MSC) and lung cancer tissues (LC-MSC) as well as normal bone marrow-derived MSC (BM-MSC) cultured in conditioned medium of HeLa cells were found to have higher expressions of Toll-like receptor (TLR4) mRNA compared with BM-MSC. The sorted TLR4-positive MSC (TLR4+ MSC) differed in cytokine (interleukin-6, interleukin-8, and monocyte chemoattractant protein-1) secretion from those of unsorted MSC. MSC was reported to inhibit natural killer (NK) cell proliferation and function. In this research, we confirmed that TLR4+ MSC aggravate this suppression. Furthermore, when TLR4 in the sorted cells were stimulated by LPS or following blocked by antibody, the suppression on NK cell proliferation and cytotoxicity were more intensive or recovered respectively. Compared to unsorted MSC, NKG2D receptor expression on NK cells were also inhibited by TLR4+ MSC. These findings suggest that activation of TLR4 pathway is important for TLR4+ MSC and MSC to obstruct anti-tumor immunity by inhibiting NK cell function, which may provide a potential stroma-targeted tumor therapy. - Highlights: • TLR4+ MSC inhibit NK cell proliferation in vivo and in vitro. • TLR4+ MSC inhibit NKG2D expression on NK cells and NK cell cytotoxicity. • The distinguished cytokine expression of TLR4+ MSC may contribute to the inhibition on NK cell function.

Mesenchymal stem cells cancel azoxymethane-induced tumor initiation.

Science.gov (United States)

Nasuno, Masanao; Arimura, Yoshiaki; Nagaishi, Kanna; Isshiki, Hiroyuki; Onodera, Kei; Nakagaki, Suguru; Watanabe, Shuhei; Idogawa, Masashi; Yamashita, Kentaro; Naishiro, Yasuyoshi; Adachi, Yasushi; Suzuki, Hiromu; Fujimiya, Mineko; Imai, Kohzoh; Shinomura, Yasuhisa

2014-04-01

The role of mesenchymal stem cells (MSCs) in tumorigenesis remains controversial. Therefore, our goal was to determine whether exogenous MSCs possess intrinsic antineoplastic or proneoplastic properties in azoxymethane (AOM)-induced carcinogenesis. Three in vivo models were studied: an AOM/dextran sulfate sodium colitis-associated carcinoma model, an aberrant crypt foci model, and a model to assess the acute apoptotic response of a genotoxic carcinogen (AARGC). We also performed in vitro coculture experiments. As a result, we found that MSCs partially canceled AOM-induced tumor initiation but not tumor promotion. Moreover, MSCs inhibited the AARGC in colonic epithelial cells because of the removal of O(6)-methylguanine (O(6) MeG) adducts through O(6) MeG-DNA methyltransferase activation. Furthermore, MSCs broadly affected the cell-cycle machinery, potentially leading to G1 arrest in vivo. Coculture of IEC-6 rat intestinal cells with MSCs not only arrested the cell cycle at the G1 phase, but also induced apoptosis. The anti-carcinogenetic properties of MSCs in vitro required transforming growth factor (TGF)-β signaling because such properties were completely abrogated by absorption of TGF-β under indirect coculture conditions. MSCs inhibited AOM-induced tumor initiation by preventing the initiating cells from sustaining DNA insults and subsequently inducing G1 arrest in the initiated cells that escaped from the AARGC. Furthermore, tumor initiation perturbed by MSCs might potentially dysregulate WNT and TGF-β-Smad signaling pathways in subsequent tumorigenesis. Obtaining a better understanding of MSC functions in colon carcinogenesis is essential before commencing the broader clinical application of promising MSC-based therapies for cancer-prone patients with inflammatory bowel disease. © AlphaMed Press.

Magnolol Inhibits the Growth of Non-Small Cell Lung Cancer via Inhibiting Microtubule Polymerization

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Jia Shen

2017-07-01

Full Text Available Background: The tubulin/microtubule system, which is an integral component of the cytoskeleton, plays an essential role in mitosis. Targeting mitotic progression by disturbing microtubule dynamics is a rational strategy for cancer treatment. Methods: Microtubule polymerization assay was performed to examine the effect of Magnolol (a novel natural phenolic compound isolated from Magnolia obovata on cellular microtubule polymerization in human non-small cell lung cancer (NSCLC cells. Cell cycle analysis, mitotic index assay, cell proliferation assay, colony formation assay, western blotting analysis of cell cycle regulators, Annexin V-FITC/PI staining, and live/dead viability staining were carried out to investigate the Magnolol’s inhibitory effect on proliferation and viability of NSCLS cells in vitro. Xenograft model of human A549 NSCLC tumor was used to determine the Magnolol’s efficacy in vivo. Results: Magnolol treatment effectively inhibited cell proliferation and colony formation of NSCLC cells. Further study proved that Magnolol induced the mitotic phase arrest and inhibited G2/M progression in a dose-dependent manner, which were mechanistically associated with expression alteration of a series of cell cycle regulators. Furthermore, Magnolol treatment disrupted the cellular microtubule organization via inhibiting the polymerization of microtubule. We also found treatment with NSCLC cells with Magnolol resulted in apoptosis activation through a p53-independent pathway, and autophgy induction via down-regulation of the Akt/mTOR pathway. Finally, Magnolol treatment significantly suppressed the NSCLC tumor growth in mouse xenograft model in vivo. Conclusion: These findings identify Magnolol as a promising candidate with anti-microtubule polymerization activity for NSCLC treatment.

Elevated levels of mitochonrial respiratory complexes activities and ATP production in 17-β-estradiol-induced prolactin-secretory tumor cells in male rats are inhibited by melatonin in vivo and in vitro.

Science.gov (United States)

Wang, Bao-Qiang; Yang, Quan-Hui; Xu, Rong-Kun; Xu, Jian-Ning

2013-01-01

Our earlier studies indicate that melatonin inhibits the proliferation of prolactinoma and induces apoptosis of pituitary prolactin-secreting tumor in rats. Melatonin has also been shown to induce apoptosis and to reduce the production of ATP in breast tumor cells. This study analyzed the levels of the four mitochondrial respiratory complexes and the production of ATP and also the effects of melatonin treatment of prolactinoma. In the in vivo study, mitochondria were harvested from control pituitaries or prolactinoma collected from the pituitaries of melatonin- and 17-β-estradiol (E2)-treated male rats. In the in vitro study, prolactinoma cells mitochondria were harvested. Activities of the four mitochondrial respiratory complexes were assayed using fluorometer. ATP production of prolactinoma cells was estimated using bioluminescent methods. Elevated levels of four mitochondrial respiratory complexes activities and ATP production were recorded in prolactinoma cells. Moreover, in both in vivo and in vitro studies, melatonin inhibited the activities of mitochondrial respiratory complexes and the production of ATP in prolactinoma cells. There is a link between mitochondrial function increase and tumorigenesis. Melatonin induces apoptosis of pituitary prolactin-secreting tumor of rats via the induction of mitochondrial dysfunction and inhibition of energy metabolism.

CysLT(1)R antagonists inhibit tumor growth in a xenograft model of colon cancer.

Science.gov (United States)

Savari, Sayeh; Liu, Minghui; Zhang, Yuan; Sime, Wondossen; Sjölander, Anita

2013-01-01

The expression of the inflammatory G-protein coupled receptor CysLT1R has been shown to be upregulated in colon cancer patients and associated with poor prognosis. The present study investigated the correlation between CysLT1R and colon cancer development in vivo using CysLT1R antagonists (ZM198,615 or Montelukast) and the nude mouse xenograft model. Two drug administration regimens were established. The first regimen was established to investigate the importance of CysLT1R in tumor initiation. Nude mice were inoculated with 50 µM CysLT1R antagonist-pretreated HCT-116 colon cancer cells and received continued treatment (5 mg/kg/day, intraperitoneally). The second regimen aimed to address the role of CysLT1R in tumor progression. Nude mice were inoculated with non-pretreated HCT-116 cells and did not receive CysLT1R antagonist treatment until recordable tumor appearance. Both regimens resulted in significantly reduced tumor size, attributed to changes in proliferation and apoptosis as determined by reduced Ki-67 levels and increased levels of p21(WAF/Cip1) (Pcolon cancer cell line HCT-116 and CysLT1R antagonists. In addition to significant reductions in cell proliferation, adhesion and colony formation, we observed induction of cell cycle arrest and apoptosis in a dose-dependent manner. The ability of Montelukast to inhibit growth of human colon cancer xenograft was further validated by using two additional colon cancer cell lines, SW-480 and HT-29. Our results demonstrate that CysLT1R antagonists inhibit growth of colon cancer xenografts primarily by reducing proliferation and inducing apoptosis of the tumor cells.

BET inhibition silences expression of MYCN and BCL2 and induces cytotoxicity in neuroblastoma tumor models.

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Anastasia Wyce

Full Text Available BET family proteins are epigenetic regulators known to control expression of genes involved in cell growth and oncogenesis. Selective inhibitors of BET proteins exhibit potent anti-proliferative activity in a number of hematologic cancer models, in part through suppression of the MYC oncogene and downstream Myc-driven pathways. However, little is currently known about the activity of BET inhibitors in solid tumor models, and whether down-regulation of MYC family genes contributes to sensitivity. Here we provide evidence for potent BET inhibitor activity in neuroblastoma, a pediatric solid tumor associated with a high frequency of MYCN amplifications. We treated a panel of neuroblastoma cell lines with a novel small molecule inhibitor of BET proteins, GSK1324726A (I-BET726, and observed potent growth inhibition and cytotoxicity in most cell lines irrespective of MYCN copy number or expression level. Gene expression analyses in neuroblastoma cell lines suggest a role of BET inhibition in apoptosis, signaling, and N-Myc-driven pathways, including the direct suppression of BCL2 and MYCN. Reversal of MYCN or BCL2 suppression reduces the potency of I-BET726-induced cytotoxicity in a cell line-specific manner; however, neither factor fully accounts for I-BET726 sensitivity. Oral administration of I-BET726 to mouse xenograft models of human neuroblastoma results in tumor growth inhibition and down-regulation MYCN and BCL2 expression, suggesting a potential role for these genes in tumor growth. Taken together, our data highlight the potential of BET inhibitors as novel therapeutics for neuroblastoma, and suggest that sensitivity is driven by pleiotropic effects on cell growth and apoptotic pathways in a context-specific manner.

Inhibition of prostate cancer osteoblastic progression with VEGF121/rGel, a single agent targeting osteoblasts, osteoclasts, and tumor neovasculature.

Science.gov (United States)

Mohamedali, Khalid A; Li, Zhi Gang; Starbuck, Michael W; Wan, Xinhai; Yang, Jun; Kim, Sehoon; Zhang, Wendy; Rosenblum, Michael G; Navone, Nora M

2011-04-15

A hallmark of prostate cancer (PCa) progression is the development of osteoblastic bone metastases, which respond poorly to available therapies. We previously reported that VEGF(121)/rGel targets osteoclast precursors and tumor neovasculature. Here we tested the hypothesis that targeting nontumor cells expressing these receptors can inhibit tumor progression in a clinically relevant model of osteoblastic PCa. Cells from MDA PCa 118b, a PCa xenograft obtained from a bone metastasis in a patient with castrate-resistant PCa, were injected into the femurs of mice. Osteoblastic progression was monitored following systemic administration of VEGF(121)/rGel. VEGF(121)/rGel was cytotoxic in vitro to osteoblast precursor cells. This cytotoxicity was specific as VEGF(121)/rGel internalization into osteoblasts was VEGF(121) receptor driven. Furthermore, VEGF(121)/rGel significantly inhibited PCa-induced bone formation in a mouse calvaria culture assay. In vivo, VEGF(121)/rGel significantly inhibited the osteoblastic progression of PCa cells in the femurs of nude mice. Microcomputed tomographic analysis revealed that VEGF(121)/rGel restored the bone volume fraction of tumor-bearing femurs to values similar to those of the contralateral (non-tumor-bearing) femurs. VEGF(121)/rGel significantly reduced the number of tumor-associated osteoclasts but did not change the numbers of peritumoral osteoblasts. Importantly, VEGF(121)/rGel-treated mice had significantly less tumor burden than control mice. Our results thus indicate that VEGF(121)/rGel inhibits osteoblastic tumor progression by targeting angiogenesis, osteoclastogenesis, and bone formation. Targeting VEGF receptor (VEGFR)-1- or VEGFR-2-expressing cells is effective in controlling the osteoblastic progression of PCa in bone. These findings provide the basis for an effective multitargeted approach for metastatic PCa. ©2011 AACR.

Targeting tumor cell invasion and dissemination in vivo by an aptamer that inhibits urokinase-type plasminogen activator through a novel multifunctional mechanism

DEFF Research Database (Denmark)

Botkjaer, Kenneth A; Deryugina, Elena I; Dupont, Daniel Miotto

2012-01-01

, because the topology of the proteases' active sites are highly similar. In an effort to generate highly specific uPA inhibitors with new inhibitory modalities, we isolated uPA-binding RNA aptamers by screening a library of 35 nucleotides long 2'-fluoro-pyrimidine RNA molecules using a version of human pro......-uPA lacking the epidermal growth factor-like and kringle domains as bait. One pro-uPA-binding aptamer sequence, referred to as upanap-126, proved to be highly specific for human uPA. Upanap-126 delayed the proteolytic conversion of human pro-uPA to active uPA, but did not inhibit plasminogen activation...... catalyzed by two-chain uPA. The aptamer also inhibited the binding of pro-uPA to uPAR and the binding of vitronectin to the preformed pro-uPA/uPAR complex, both in cell-free systems and on cell surfaces. Furthermore, upanap-126 inhibited human tumor cell invasion in vitro in the Matrigel assay and in vivo...

Effect of selenodiglutathione on the metabolism of canine mammary tumor cells

International Nuclear Information System (INIS)

Fico-Santoro, M.; Lebowitz, A.; Milner, J.A.

1986-01-01

Selenodiglutathione (SDG) has been shown to be an effective inhibitor of tumor growth. The present studies were designed to evaluate altered metabolism in canine mammary tumor cells (CMT-13) exposed to various concentrations of SDG. Addition of SDG at 0.025 μg Se/ml did not inhibit growth of CMT-13 cells after 24 h of incubation. At this concentration of SDG, approximately 25% of 75 Se- 35 S-SDG was retained in these tumor cells after 24 h of incubation. The nuclear fraction contained 96% of the 75 Se and 35 S radioactivity. The ratio of 75 Se to 35 S was 1 to 4.5 in the whole cell and in the nuclear fraction. SDG increased glutathione peroxidase activity by 40% compared to CMT-13 cells not exposed to SDG. Glutathione reductase activity was decreased by 63% by the addition of SDG. In addition, supplemental SDG resulted in a 55% decrease in GSH content but did not alter GSSG concentrations. After 4d of incubation, SDG at 0.1 and 0.5 μg Se/ml caused a 43 and 58% inhibition of growth of CMT-13 cells. Addition of GSH (100μM) partially prevented, 68% and 54%, the growth inhibition caused by SDG at concentrations of 0.1 and 0.5 μg Se per ml respectively during the 4d incubation period. Preincubation of CMT-13 cells with GSH for 48 h before addition of SDG (0.5 μg Se/ml) completely prevented the growth inhibition caused by this seleno-compound

The Immunomodulatory Effects of Mesenchymal Stem Cell Polarization within the Tumor Microenvironment Niche

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Cosette M. Rivera-Cruz

2017-01-01

Full Text Available Mesenchymal stem cells (MSCs represent a promising tool for cell therapy, particularly for their antitumor effects. This cell population can be isolated from multiple tissue sources and also display an innate ability to home to areas of inflammation, such as tumors. Upon entry into the tumor microenvironment niche, MSCs promote or inhibit tumor progression by various mechanisms, largely through the release of soluble factors. These factors can be immunomodulatory by activating or inhibiting both the adaptive and innate immune responses. The mechanisms by which MSCs modulate the immune response are not well understood. Because of this, the relationship between MSCs and immune cells within the tumor microenvironment niche continues to be an active area of research in order to help explain the apparent contradictory findings currently available in the literature. The ongoing research aims to enhance the potential of MSCs in future therapeutic applications.

Stable SET knockdown in breast cell carcinoma inhibits cell migration and invasion

Energy Technology Data Exchange (ETDEWEB)

Li, Jie [Department of Occupational Health and Occupational Medicine, School of Public Health and Tropical Medicine, Southern Medical University, Guangzhou (China); Key Laboratory of Modern Toxicology of Shenzhen, Shenzhen Center for Disease Control and Prevention, Shenzhen (China); Yang, Xi-fei [Key Laboratory of Modern Toxicology of Shenzhen, Shenzhen Center for Disease Control and Prevention, Shenzhen (China); Ren, Xiao-hu [Department of Occupational Health and Occupational Medicine, School of Public Health and Tropical Medicine, Southern Medical University, Guangzhou (China); Key Laboratory of Modern Toxicology of Shenzhen, Shenzhen Center for Disease Control and Prevention, Shenzhen (China); Meng, Xiao-jing [Department of Occupational Health and Occupational Medicine, School of Public Health and Tropical Medicine, Southern Medical University, Guangzhou (China); Huang, Hai-yan [Key Laboratory of Modern Toxicology of Shenzhen, Shenzhen Center for Disease Control and Prevention, Shenzhen (China); Zhao, Qiong-hui [Shenzhen Entry-Exit Inspection and Quarantine Bureau, Shenzhen (China); Yuan, Jian-hui; Hong, Wen-xu; Xia, Bo; Huang, Xin-feng; Zhou, Li [Key Laboratory of Modern Toxicology of Shenzhen, Shenzhen Center for Disease Control and Prevention, Shenzhen (China); Liu, Jian-jun, E-mail: bio-research@hotmail.com [Key Laboratory of Modern Toxicology of Shenzhen, Shenzhen Center for Disease Control and Prevention, Shenzhen (China); Zou, Fei, E-mail: zoufei616@163.com [Department of Occupational Health and Occupational Medicine, School of Public Health and Tropical Medicine, Southern Medical University, Guangzhou (China)

2014-10-10

Highlights: • We employed RNA interference to knockdown SET expression in breast cancer cells. • Knockdown of SET expression inhibits cell proliferation, migration and invasion. • Knockdown of SET expression increases the activity and expression of PP2A. • Knockdown of SET expression decreases the expression of MMP-9. - Abstract: Breast cancer is the most malignant tumor for women, however, the mechanisms underlying this devastating disease remain unclear. SET is an endogenous inhibitor of protein phosphatase 2A (PP2A) and involved in many physiological and pathological processes. SET could promote the occurrence of tumor through inhibiting PP2A. In this study, we explore the role of SET in the migration and invasion of breast cancer cells MDA-MB-231 and ZR-75-30. The stable suppression of SET expression through lentivirus-mediated RNA interference (RNAi) was shown to inhibit the growth, migration and invasion of breast cancer cells. Knockdown of SET increases the activity and expression of PP2Ac and decrease the expression of matrix metalloproteinase 9 (MMP-9). These data demonstrate that SET may be involved in the pathogenic processes of breast cancer, indicating that SET can serve as a potential therapeutic target for the treatment of breast cancer.

Stable SET knockdown in breast cell carcinoma inhibits cell migration and invasion

International Nuclear Information System (INIS)

Li, Jie; Yang, Xi-fei; Ren, Xiao-hu; Meng, Xiao-jing; Huang, Hai-yan; Zhao, Qiong-hui; Yuan, Jian-hui; Hong, Wen-xu; Xia, Bo; Huang, Xin-feng; Zhou, Li; Liu, Jian-jun; Zou, Fei

2014-01-01

Highlights: • We employed RNA interference to knockdown SET expression in breast cancer cells. • Knockdown of SET expression inhibits cell proliferation, migration and invasion. • Knockdown of SET expression increases the activity and expression of PP2A. • Knockdown of SET expression decreases the expression of MMP-9. - Abstract: Breast cancer is the most malignant tumor for women, however, the mechanisms underlying this devastating disease remain unclear. SET is an endogenous inhibitor of protein phosphatase 2A (PP2A) and involved in many physiological and pathological processes. SET could promote the occurrence of tumor through inhibiting PP2A. In this study, we explore the role of SET in the migration and invasion of breast cancer cells MDA-MB-231 and ZR-75-30. The stable suppression of SET expression through lentivirus-mediated RNA interference (RNAi) was shown to inhibit the growth, migration and invasion of breast cancer cells. Knockdown of SET increases the activity and expression of PP2Ac and decrease the expression of matrix metalloproteinase 9 (MMP-9). These data demonstrate that SET may be involved in the pathogenic processes of breast cancer, indicating that SET can serve as a potential therapeutic target for the treatment of breast cancer

Diclofenac Inhibits Tumor Growth in a Murine Model of Pancreatic Cancer by Modulation of VEGF Levels and Arginase Activity

OpenAIRE

Mayorek, Nina; Naftali-Shani, Nili; Grunewald, Myriam

2010-01-01

BACKGROUND: Diclofenac is one of the oldest anti-inflammatory drugs in use. In addition to its inhibition of cyclooxygenases (COX), diclofenac potently inhibits phospholipase A(2) (PLA(2)), thus yielding a broad anti-inflammatory effect. Since inflammation is an important factor in the development of pancreatic tumors we explored the potential of diclofenac to inhibit tumor growth in mice inoculated with PANCO2 cells orthotopically. METHODOLOGY/PRINCIPAL FINDINGS: We found that diclofenac tre...

The histone deacetylase inhibitor SAHA acts in synergism with fenretinide and doxorubicin to control growth of rhabdoid tumor cells

International Nuclear Information System (INIS)

Kerl, Kornelius; Eveslage, Maria; Jung, Manfred; Meisterernst, Michael; Frühwald, Michael; Ries, David; Unland, Rebecca; Borchert, Christiane; Moreno, Natalia; Hasselblatt, Martin; Jürgens, Heribert; Kool, Marcel; Görlich, Dennis

2013-01-01

Rhabdoid tumors are highly aggressive malignancies affecting infants and very young children. In many instances these tumors are resistant to conventional type chemotherapy necessitating alternative approaches. Proliferation assays (MTT), apoptosis (propidium iodide/annexin V) and cell cycle analysis (DAPI), RNA expression microarrays and western blots were used to identify synergism of the HDAC (histone deacetylase) inhibitor SAHA with fenretinide, tamoxifen and doxorubicin in rhabdoidtumor cell lines. HDAC1 and HDAC2 are overexpressed in primary rhabdoid tumors and rhabdoid tumor cell lines. Targeting HDACs in rhabdoid tumors induces cell cycle arrest and apoptosis. On the other hand HDAC inhibition induces deregulated gene programs (MYCC-, RB program and the stem cell program) in rhabdoid tumors. These programs are in general associated with cell cycle progression. Targeting these activated pro-proliferative genes by combined approaches of HDAC-inhibitors plus fenretinide, which inhibits cyclinD1, exhibit strong synergistic effects on induction of apoptosis. Furthermore, HDAC inhibition sensitizes rhabdoid tumor cell lines to cell death induced by chemotherapy. Our data demonstrate that HDAC inhibitor treatment in combination with fenretinide or conventional chemotherapy is a promising tool for the treatment of chemoresistant rhabdoid tumors

Autotaxin inhibition with PF8380 enhances the radiosensitivity of human and murine glioblastoma cell lines

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Sandeep R Bhave

2013-09-01

Full Text Available Purpose: Glioblastoma multiforme (GBM is an aggressive primary brain tumor that is radio-resistant and recurs despite aggressive surgery, chemo and radiotherapy. Autotaxin (ATX is over expressed in various cancers including GBM and is implicated in tumor progression, invasion, and angiogenesis. Using the ATX specific inhibitor, PF-8380, we studied ATX as a potential target to enhance radiosensitivity in GBM.Methods and Materials: Mouse GL-261 and Human U87MG cells were used as GBM cell models. Clonogenic survival assays and tumor transwell invasion assays were performed using PF-8380 to evaluate role of ATX in survival and invasion. Radiation dependent activation of Akt was analyzed by immunoblotting. Tumor induced angiogenesis was studied using the dorsal skin-fold model in Gl-261. Heterotopic mouse GL-261 tumors were used to evaluate the efficacy of PF-8380 as a radiosensitizer.Results: Pretreatment of GL-261 and U87-MG cells with 1µM PF-8380 followed by 4Gy irradiation resulted in decreased clonogenic survival, decreased migration (33% in GL-261;P = 0.002 and 17.9% in U87; P = 0.012 decreased invasion (35.6% in GL-261; P = 0.0037 and 31.8% in U87; P = 0.002, and attenuated radiation induced Akt phosphorylation. In the tumor window model inhibition of ATX abrogated radiation-induced tumor neovascularization (65%; P=0.011. In a heterotopic mouse GL-261 tumors untreated mice took 11.2 days to reach a tumor volume of 7000 mm3 , however combination of PF-8380 (10mg/kg with irradiation (5 fractions of 2Gy took more than 32 days to reach a tumor volume of 7000 mm3 .Conclusion: Inhibition of ATX by PF8380 led to decreased invasion and enhanced radiosensitization of glioma cells. Radiation induced activation of Akt was abrogated by inhibition of ATX. Furthermore, inhibition of ATX led to diminished tumor vascularity and delayed tumor growth. These results suggest that inhibition of ATX may ameliorate glioblastoma response to radiotherapy.