Using Acetaminophen's Toxicity Mechanism to Enhance Cisplatin Efficacy in Hepatocarcinoma and Hepatoblastoma Cell Lines

Directory of Open Access Journals (Sweden)

Alexander J. Neuwelt

2009-10-01

Conclusions: Our results suggest that a chemotherapeutic regimen containing both AAP and CDDP with delayed NAC rescue has the potential to enhance chemotherapeutic efficacy while decreasing adverse effects. This would be a promising approach particularly for hepatoblastomas regardless of cellular CYP2E1 protein level but could also be beneficial in other malignancies.

Ante situm liver resection with inferior vena cava replacement under hypothermic cardiopolmunary bypass for hepatoblastoma: Report of a case and review of the literature

Directory of Open Access Journals (Sweden)

Roberta Angelico

2017-01-01

Conclusions: We report for the first time a case of ante situ liver resection and inferior-vena-cava replacement associated with hypothermic cardiopulmonary bypass in a child with hepatoblastoma. Herein, we extensively review the literature for hepatoblastoma with thumoral thrombi and we describe the technical aspects of ante situm approach, which is a realistic option in otherwise unresectable hepatoblastoma.

Comprehensive analyses of imprinted differentially methylated regions reveal epigenetic and genetic characteristics in hepatoblastoma

International Nuclear Information System (INIS)

Rumbajan, Janette Mareska; Aoki, Shigehisa; Kohashi, Kenichi; Oda, Yoshinao; Hata, Kenichiro; Saji, Tsutomu; Taguchi, Tomoaki; Tajiri, Tatsuro; Soejima, Hidenobu; Joh, Keiichiro; Maeda, Toshiyuki; Souzaki, Ryota; Mitsui, Kazumasa; Higashimoto, Ken; Nakabayashi, Kazuhiko; Yatsuki, Hitomi; Nishioka, Kenichi; Harada, Ryoko

2013-01-01

Aberrant methylation at imprinted differentially methylated regions (DMRs) in human 11p15.5 has been reported in many tumors including hepatoblastoma. However, the methylation status of imprinted DMRs in imprinted loci scattered through the human genome has not been analyzed yet in any tumors. The methylation statuses of 33 imprinted DMRs were analyzed in 12 hepatoblastomas and adjacent normal liver tissue by MALDI-TOF MS and pyrosequencing. Uniparental disomy (UPD) and copy number abnormalities were investigated with DNA polymorphisms. Among 33 DMRs analyzed, 18 showed aberrant methylation in at least 1 tumor. There was large deviation in the incidence of aberrant methylation among the DMRs. KvDMR1 and IGF2-DMR0 were the most frequently hypomethylated DMRs. INPP5Fv2-DMR and RB1-DMR were hypermethylated with high frequencies. Hypomethylation was observed at certain DMRs not only in tumors but also in a small number of adjacent histologically normal liver tissue, whereas hypermethylation was observed only in tumor samples. The methylation levels of long interspersed nuclear element-1 (LINE-1) did not show large differences between tumor tissue and normal liver controls. Chromosomal abnormalities were also found in some tumors. 11p15.5 and 20q13.3 loci showed the frequent occurrence of both genetic and epigenetic alterations. Our analyses revealed tumor-specific aberrant hypermethylation at some imprinted DMRs in 12 hepatoblastomas with additional suggestion for the possibility of hypomethylation prior to tumor development. Some loci showed both genetic and epigenetic alterations with high frequencies. These findings will aid in understanding the development of hepatoblastoma

Hepatoblastoma imaging with gadoxetate disodium-enhanced MRI - typical, atypical, pre- and post-treatment evaluation

Energy Technology Data Exchange (ETDEWEB)

Meyers, Arthur B. [Cincinnati Children' s Hospital Medical Center, Department of Radiology, Cincinnati, OH (United States); Medical College of Wisconsin, Department of Radiology, Milwaukee, WI (United States); Children' s Hospital of Wisconsin, Department of Pediatric Imaging, Milwaukee, WI (United States); Towbin, Alexander J.; Podberesky, Daniel J. [Cincinnati Children' s Hospital Medical Center, Department of Radiology, Cincinnati, OH (United States); Geller, James I. [Cincinnati Children' s Hospital Medical Center, Department of Hematology/Oncology, Cincinnati, OH (United States)

2012-07-15

Gadoxetate disodium (Gd-EOB-DTPA) is a hepatobiliary MRI contrast agent widely used in adults for characterization of liver tumors and increasingly used in children. Hepatoblastoma is the most common primary hepatic malignancy of childhood. In this review, we describe our experience with this agent both before and after initiating therapy in children with hepatoblastoma. (orig.)

Lessons from the hepatoblastoma-familial polyposis connection ...

African Journals Online (AJOL)

Background. Approximately one-third of hepatoblastoma (HB) patients have associated congenital abnormalities, but familial recurrence is rare, except in association with familial adenomatous polyposis (FAP). This correlation may be missed if not actively sought, with implications for long-term outcome and management.

Effectiveness of transarterial chemoembolization in hepatoblastoma: a preliminary study

International Nuclear Information System (INIS)

Park, Hark Hoon; Han, Young Min; Kang, Sung Soo; Kim, Jae Chun; Lee, Dong Geun; Hwang, Pyoung Han; Kim, Chong Soo; Lee, Jeong Min

1998-01-01

To evaluate the therapeutic effectiveness and useful as well as the ness, systemic effect and effectiveness, of preoperative TACE when used in patients with unresectable or high risk hepatoblastoma. We retrospectively evaluated four patients with pathologically proven hepatoblastoma. One was male and three were female, and they were aged between 8 and 27 (mean, 15) months. All underwent selective hepatic angiography and chemoembolization after superselection of tumor feeding vessels. Cisplatin 90mg/m 2 (50-80mg), adriamycine 40mg/m 2 (20mg) and lipiodol suspension 4cc ere used as chemotherapeutic agents. Embolization was then performed, gelfoam particles. TACE was repeated at intervals of 3 weeks, and after the second episode, all patients underwent hepatic resection. To evaluate changes in the size, volume, internal texture and margin of the mass, as well as the systemic toxicity of chemotherapeutic drugs, we performed con-trast-enhanced CT and checked AFP,CBC and GOT/GPT before and after TACE. In all patients, TACE was successfully performed and major problems related to the procedure and toxicity of chemotherapeutic agents used were not noted. The largest diameter and volume of tumors were reduced by 33% (from 8.3 to 5.6 cm) and 69% respectively. Tumor necrosis was evident in all patients. Lipiodol uptake by tumors was homogenous and tumors were well distingulished from normal parenchyma. Compared to pre-TACE, serum alpha-feto-protein was reduced from 994(range:615--1690 ng/ml) to 46 ng/ml(42-- 47ng/ml) after the second TACE, and six months after surgery was in the normal range(13ng/ml;3--23ng/ml). SGOT/SGPT levels were temporally elevated after TACE but normalized within a few weeks. TACE can be a useful technique for preoperative treatment of hepatoblestomas. In tomors which are high-risk or inoperable, the therapeutio agents involved were not shown to be toxic.=20

Delta-like protein (DLK) is a novel immunohistochemical marker for human hepatoblastomas

DEFF Research Database (Denmark)

Dezso, Katalin; Halász, Judit; Bisgaard, Hanne Cathrine

2008-01-01

Delta-like protein (DLK) is a membrane protein with mostly unknown function. It is expressed by several embryonic tissues among others by the hepatoblasts of rodent and human fetal livers. We have investigated in the present study if this protein is expressed in human hepatoblastomas. The presenc...

Preoperative Transcatheter Selective Arterial Chemoembolization in Treatment of Unresectable Hepatoblastoma in Infants and Children

International Nuclear Information System (INIS)

Li Jiaping; Chu Jianping; Yang Jianyong; Chen Wei; Wang Yu; Huang Yonghui

2008-01-01

The purpose of this study was to evaluate the clinical feasibility and efficacy of transcatheter selective arterial chemoembolization (TACE) for unresectable hepatoblastoma in infants and children. The study was performed with the approval of our institutional review board. Sixteen patients (13 boys, 3 girls) with unresectable hepatoblastoma were treated one to three times with preoperative TACE in an effort to improve the surgical and clinical outcome. Their ages ranged from 50 days to 60 months, with a mean age of 20.4 months. All cases were pathologically proved hepatoblastoma by fine-needle biopsy. After an intra-arterial catheter was selectively inserted into the main feeding artery of the tumor, cycles of cisplatin (40 to 50 mg/m 2 ) and adriamycin (20 to 30 mg/m 2 ) mixed with lipiodol were given, followed by gelatin foam particles or stainless-steel coils. Tumor response was evaluated according to tumor shrinkage, α-fetoprotein (AFP) levels, and pathological findings. TACE procedure was performed one to three times, depending on the patient's response. Surgical resection was carried out when the tumor volume appeared sufficiently reduced to allow safe resection by either lobectomy or extended lobectomy. A marked reduction in tumor size associated with decreased AFP level occurred after treatment. According to paired-samples test, tumor shrinkage ranged from 19.0% to 82.0%, with a mean value of 59.2%. AFP levels decreased 99.0% to 29.0% from initial levels, with a mean decrease of 60.0%. TACE allowed subsequent complete surgical resection in 13 cases and the other 3 cases underwent partial resection. One patient underwent successful orthotopic liver transplantation after receiving TACE therapy. Pathological examination showed that the mean percentage of necrotic area in the surgical specimens was 87%. Overall survival rate at 1, 3, and 5 years was 87.5%, 68.7%, and 50%, respectively. Correspondingly, event-free survival rate was 75%, 62.5%, and 43

Anaphylatoxin C3a induced mediator release from mast cells

International Nuclear Information System (INIS)

Herrscher, R.; Hugli, T.E.; Sullivan, T.J.

1986-01-01

The authors investigated the biochemical and functional consequences of the binding of highly purified human C3a to isolated rat serosal mast cells. C3a caused a dose-dependent (1-30 μM), noncytotoxic release of up to 64% (+/- 7 SEM) of the mast cell histamine content. C3a (10μM) increased 45 Ca ++ uptake 8.2- fold (+/- 2.2 SEM) above unstimulated control values within 10 minutes. Arachidonyl-diacylglycerol and arachidonyl-monoacylglycerol levels increased significantly within 2 minutes after C3a (10 μM) stimulation. Turnover of phosphatidylinositol, phosphatidic acid, and phosphatidylcholine were increased within 15 minutes. In contrast to antigen, C3a stimulation (10 μM) was not enhanced by exogenous phosphatidylserine, and was not inhibited by ethanol (100 μmM). C3a suppressed arachidonic acid (AA) release to 38% (+/- 9 SEM) below baseline, and did not cause PGD 2 formation. C3a and the desarginine form of C3a caused identical responses in all experiments. These studies indicate that C3a stimulation activates mast cell preformed mediator release in a manner very similar to antigen-IgE stimulation, but C3a suppresses free AA levels and does not stimulate PGD 2 synthesis

Thrombopoietin stimulates migration and activates multiple signaling pathways in hepatoblastoma cells

DEFF Research Database (Denmark)

Romanelli, Roberto G; Petrai, Ilaria; Robino, Gaia

2005-01-01

Thrombopoietin (TPO), a cytokine that participates in the differentiation and maturation of megakaryocytes, is produced in the liver, but only limited information is available on the biological response of liver-derived cells to TPO. In this study, we investigated whether HepG2 cells express c-Mpl......, the receptor for TPO, and whether TPO elicits biological responses and intracellular signaling in this cell type. Specific transcripts for c-Mpl were detected in HepG2 cells by RT-PCR, and expression of the protein was demonstrated by Western blot analysis and immunofluorescence. Exposure of HepG2 cells to TPO...... members of the MAPK family, including ERK and JNK, as assessed using phosphorylation-specific antibodies and immune complex kinase assays. TPO also activated phosphatidylinositol 3-kinase (PI3K) and the downstream kinase Akt in a time-dependent manner. Finally, activation of c-Mpl was associated...

Serum microRNA miR-206 is decreased in hyperthyroidism and mediates thyroid hormone regulation of lipid metabolism in HepG2 human hepatoblastoma cells.

Science.gov (United States)

Zheng, Yingjuan; Zhao, Chao; Zhang, Naijian; Kang, Wenqin; Lu, Rongrong; Wu, Huadong; Geng, Yingxue; Zhao, Yaping; Xu, Xiaoyan

2018-04-01

The actions of thyroid hormone (TH) on lipid metabolism in the liver are associated with a number of genes involved in lipogenesis and lipid metabolism; however, the underlying mechanisms through which TH impacts on lipid metabolism remain to be elucidated. The present study aimed to investigate the effects of hyperthyroidism on the serum levels of the microRNA (miR) miR‑206 and the role of miR‑206 on TH‑regulated lipid metabolism in liver cells. Serum was obtained from 12 patients diagnosed with hyperthyroidism and 10 healthy control subjects. Human hepatoblastoma (HepG2) cells were used to study the effects of triiodothyronine (T3) and miR‑206 on lipid metabolism. Expression of miR‑206 in serum and cells was determined by reverse transcription‑quantitative polymerase chain reaction analysis. Lipid accumulation in HepG2 cells was assessed with Oil Red O staining. Suppression or overexpression of miR‑206 was performed via transfection with a miR‑206 mimic or miR‑206 inhibitor. Serum miR‑206 was significantly decreased in patients with hyperthyroidism compared with euthyroid controls. Treatment of HepG2 cells with T3 led to reduced total cholesterol (TC) and triglyceride (TG) content, accompanied by reduced miR‑206 expression. Inhibition of endogenous miR‑206 expression decreased intracellular TG and TC content in HepG2 cells. By contrast, overexpression of miR‑206 in HepG2 partially prevented the reduction in TG content induced by treatment with T3. In conclusion, serum miR‑206 expression is reduced in patients with hyperthyroidism. In addition, miR‑206 is involved in T3‑mediated regulation of lipid metabolism in HepG2 cells, indicating a role for miR‑206 in thyroid hormone‑induced disorders of lipid metabolism in the liver.

CT findings of hepatoblastoma before and after chemotherapy : correlation with pathologic features

International Nuclear Information System (INIS)

Seo, Joon Beom; Kim, Woo Sun; Kim, In One; Jang, Ja June; Kim, Chong Jai; Ahn, Hyo Seop; Yeon, Kyung Mo

1998-01-01

The purpose of this study was to analyze the CT findings of hepatoblastoma before and after chemotherapy, and to compare them with surgical and pathologic features. Twelve hepatoblastoma patients underwent chemotherapy prior to surgery; in all cases, CT scanning was performed before and after chemotherapy. We reviewed the findings with special attention to changes in tumor volume, the extent and pattern of contrast enhancement, the extent of low-attenuation area in the tumor, the presence of a septum, and calcification or ossification or ossification within the mass before and after chemotherapy. Post-chemotherapy CT findings were compared with operative and pathologic findings. After chemotheapy, the volume of the tumor mass decreased in all patients, and the extent of involved segments decreased in nine (75%), the non-enhancing area within the mass, on the other hand, increased in nine (75 %). On pre-chemotherapy CT, calcifications were detected in seven patients (58%), and on post-chemotherapy CT, in nine (75%); the extent of calcification were detected in seven patients. On the basis of CT findings, viable tumor and necrosis areas could not be distinguished. Massive calcification or osteoid mixed with loose connective tissue was noted in the mesenchymal component of the tumor; the whirling pattern of enhancement within the area of low density seen on CT scanning corresponded to osteoid mixed with loose connective tissue, which contained rich blood vessels. We describe the CT findings of hepatoblastoma both before and after chemotherapy, highlighting the changes which occurred. An understanding of these changes is helpful for the proper management of this condition. (author). 18 refs., 1 tab., 5 figs

C3a Enhances the Formation of Intestinal Organoids through C3aR1

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Naoya Matsumoto

2017-09-01

Full Text Available C3a is important in the regulation of the immune response as well as in the development of organ inflammation and injury. Furthermore, C3a contributes to liver regeneration but its role in intestinal stem cell function has not been studied. We hypothesized that C3a is important for intestinal repair and regeneration. Intestinal organoid formation, a measure of stem cell capacity, was significantly limited in C3-deficient and C3a receptor (C3aR 1-deficient mice while C3a promoted the growth of organoids from normal mice by supporting Wnt-signaling but not from C3aR1-deficient mice. Similarly, the presence of C3a in media enhanced the expression of the intestinal stem cell marker leucine-rich repeat G-protein-coupled receptor 5 (Lgr5 and of the cell proliferation marker Ki67 in organoids formed from C3-deficient but not from C3aR1-deficient mice. Using Lgr5.egfp mice we showed significant expression of C3 in Lgr5+ intestinal stem cells whereas C3aR1 was expressed on the surface of various intestinal cells. C3 and C3aR1 expression was induced in intestinal crypts in response to ischemia/reperfusion injury. Finally, C3aR1-deficient mice displayed ischemia/reperfusion injury comparable to control mice. These data suggest that C3a through interaction with C3aR1 enhances stem cell expansion and organoid formation and as such may have a role in intestinal regeneration.

Azathioprine desensitizes liver cancer cells to insulin-like growth factor 1 and causes apoptosis when it is combined with bafilomycin A1

International Nuclear Information System (INIS)

Hernández-Breijo, Borja; Monserrat, Jorge; Román, Irene D.; González-Rodríguez, Águeda; Fernández-Moreno, M. Dolores

2013-01-01

Hepatoblastoma is a primary liver cancer that affects children, due to the sensitivity of this tumor to insulin-like growth factor 1 (IGF-1). In this paper we show that azathioprine (AZA) is capable of inhibiting IGF1-mediated signaling cascade in HepG2 cells. The efficiency of AZA on inhibition of proliferation differs in the evaluated cell lines as follows: HepG2 (an experimental model of hepatoblastoma) > Hep3B (derived from a hepatocellular carcinoma) > HuH6 (derived from a hepatoblastoma) ≫ HuH7 (derived from a hepatocellular carcinoma) = Chang Liver cells (a non-malignant cellular model). The effect of AZA in HepG2 cells has been proven to derive from activation of Ras/ERK/TSC2, leading to activation of mTOR/p70S6K in a sustained manner. p70S6K phosphorylates IRS-1 in serine 307 which leads to the uncoupling between IRS-1 and p85 (the regulatory subunit of PI3K) and therefore causing the lack of response of HepG2 to IGF-1. As a consequence, proliferation induced by IGF-1 is inhibited by AZA and autophagy increases leading to senescence of HepG2 cells. Our results suggest that AZA induces the autophagic process in HepG2 activating senescence, and driving to deceleration of cell cycle but not to apoptosis. However, when simultaneous to AZA treatment the autophagy was inhibited by bafilomycin A1 and the degradation of regulatory proteins of cell cycle (e.g. Rb, E2F, and cyclin D1) provoked apoptosis. In conclusion, AZA induces resistance in hepatoblastoma cells to IGF-1, which leads to autophagy activation, and causes apoptosis when it is combined with bafilomycin A1. We are presenting here a novel mechanism of action of azathioprine, which could be useful in treatment of IGF-1 dependent tumors, especially in its combination with other drugs. - Highlights: • Azathioprine activated Ras/ERK/TSC-2/mTOR/p70S6K signaling pathway in HepG2 cells. • Azathioprine inhibited IGF-1-mediated signaling cascade. • Azathioprine induced autophagy leading to cell cycle

Azathioprine desensitizes liver cancer cells to insulin-like growth factor 1 and causes apoptosis when it is combined with bafilomycin A1

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Hernández-Breijo, Borja [Departamento de Biología de Sistemas, Centro de Investigación Biomédica en Red de Enfermedades Hepáticas y Digestivas (CIBEREHD), Universidad de Alcalá, 28871 Alcalá de Henares (Spain); Monserrat, Jorge [Departamento de Medicina y Especialidades Médicas, Universidad de Alcalá, 28871 Alcalá de Henares (Spain); Román, Irene D. [Departamento de Biología de Sistemas, Centro de Investigación Biomédica en Red de Enfermedades Hepáticas y Digestivas (CIBEREHD), Universidad de Alcalá, 28871 Alcalá de Henares (Spain); González-Rodríguez, Águeda [Departamento de Biomedicina y Biotecnología, Instituto Ramón y Cajal de Investigación Sanitaria (IRYCIS), Universidad de Alcalá, 28871 Alcalá de Henares (Spain); Fernández-Moreno, M. Dolores [Departamento de Biología de Sistemas, Centro de Investigación Biomédica en Red de Enfermedades Hepáticas y Digestivas (CIBEREHD), Universidad de Alcalá, 28871 Alcalá de Henares (Spain); and others

2013-11-01

Hepatoblastoma is a primary liver cancer that affects children, due to the sensitivity of this tumor to insulin-like growth factor 1 (IGF-1). In this paper we show that azathioprine (AZA) is capable of inhibiting IGF1-mediated signaling cascade in HepG2 cells. The efficiency of AZA on inhibition of proliferation differs in the evaluated cell lines as follows: HepG2 (an experimental model of hepatoblastoma) > Hep3B (derived from a hepatocellular carcinoma) > HuH6 (derived from a hepatoblastoma) ≫ HuH7 (derived from a hepatocellular carcinoma) = Chang Liver cells (a non-malignant cellular model). The effect of AZA in HepG2 cells has been proven to derive from activation of Ras/ERK/TSC2, leading to activation of mTOR/p70S6K in a sustained manner. p70S6K phosphorylates IRS-1 in serine 307 which leads to the uncoupling between IRS-1 and p85 (the regulatory subunit of PI3K) and therefore causing the lack of response of HepG2 to IGF-1. As a consequence, proliferation induced by IGF-1 is inhibited by AZA and autophagy increases leading to senescence of HepG2 cells. Our results suggest that AZA induces the autophagic process in HepG2 activating senescence, and driving to deceleration of cell cycle but not to apoptosis. However, when simultaneous to AZA treatment the autophagy was inhibited by bafilomycin A1 and the degradation of regulatory proteins of cell cycle (e.g. Rb, E2F, and cyclin D1) provoked apoptosis. In conclusion, AZA induces resistance in hepatoblastoma cells to IGF-1, which leads to autophagy activation, and causes apoptosis when it is combined with bafilomycin A1. We are presenting here a novel mechanism of action of azathioprine, which could be useful in treatment of IGF-1 dependent tumors, especially in its combination with other drugs. - Highlights: • Azathioprine activated Ras/ERK/TSC-2/mTOR/p70S6K signaling pathway in HepG2 cells. • Azathioprine inhibited IGF-1-mediated signaling cascade. • Azathioprine induced autophagy leading to cell cycle

Surveillance Recommendations for Children with Overgrowth Syndromes and Predisposition to Wilms Tumors and Hepatoblastoma

NARCIS (Netherlands)

Kalish, Jennifer M.; Doros, Leslie; Helman, Lee J.; Hennekam, Raoul C.; Kuiper, Roland P.; Maas, Saskia M.; Maher, Eamonn R.; Nichols, Kim E.; Plon, Sharon E.; Porter, Christopher C.; Rednam, Surya; Schultz, Kris Ann P.; States, Lisa J.; Tomlinson, Gail E.; Zelley, Kristin; Druley, Todd E.

2017-01-01

A number of genetic syndromes have been linked to increased risk for Wilms tumor (WT), hepatoblastoma (HB), and other embryonal tumors. Here, we outline these rare syndromes with at least a 1% risk to develop these tumors and recommend uniform tumor screening recommendations for North America.

Characterization of the N-methoxyindole-3-carbinol (NI3C)–Induced Cell Cycle Arrest in Human Colon Cancer Cell Lines

DEFF Research Database (Denmark)

Neave, Antje S.; Sarup, Sussi; Seidelin, Michel

2005-01-01

Recent results have shown that indole-3-carbinol (I3C) inhibits the cellular growth of human cancer cell lines. In some cruciferous vegetables, another indole, N-methoxyindole-3-carbinol (NI3C), is found beside I3C. Knowledge about the biological effects of NI3C is limited. The aim of the present...... study was to show the effect of NI3C on cell growth of two human colon cancer cell lines, DLD-1 and HCT-116. For the first time it is shown that NI3C inhibits cellular growth of DLD-1 and HCT-116 and that NI3C is a more potent inhibitor of cell proliferation than I3C. In addition to the inhibition...... of cellular proliferation, NI3C caused an accumulation of HCT-116 cells in the G2/M phase, in contrast to I3C, which led to an accumulation of the colon cells in G0/G1 phase. Furthermore, NI3C delays the G1-S phase transition of synchronized HCT-116 cells. The indole-mediated cell-cycle arrest may be related...

The radioprotective effects of carboxy fullerene C3 on AHH-1 cell

International Nuclear Information System (INIS)

Shan, Husheng; Cai, Jianming; Huang, Yuecheng; Cui, Jianguo; Liu, Hanchen; Sun, Ding; Zhao, Fang; Dong, Junru; Li, Bailong

2008-01-01

Purpose: To investigate the radioprotective effects of carboxy fullerene C 3 on AHH-1 cell and it's prospective as a novel radioprotectant. Materials and Methods: Carboxy fullerene C 3 was prepared by chemical synthesis and trypan blue rejection test was performed to detect its cytotoxicity to AHH-1 cell. Then different concentration of C 3 was used to treat AHH-1 cells after radiated with 60 Coγ ray. Annexin-V/PI staining and flow cytometry assay were applied to assess the cell proliferation and apoptosis after irradiation. Results: C 3 showed little toxicity to AHH-1 cells with little change of trypan blue rejection rate during the drug concentration range 0-400 mg/L (P>0.05). We found in this study C 3 had good radioprotective effects to AHH-1 cell radiated with 1-8 Gy γ-ray. When the concentration was 10 mg/L, C 3 showed protection effects to AHH-1 cell irradiated with 4 Gy γ -ray, which was enhanced with increase of C 3 concentration. When the final concentration reached 200-400 mg/L, the cell survival rate after irradiation was similar to that of non-irradiated control cells(P >0.05). And the irradiation induced apoptosis and death rate were significantly lower than that of single radiation group cells(P 3 were time-dependant, and the best protection effects were observed when the C 3 was administered before irradiation (0-24 h). Conclusion: Carboxy fullerene C 3 has good radioprotective effects to AHH-1 cell, which is dose-dependent, and the higher concentration of C 3 is, the better protective effects it shows. In the effective drug concentration range of this study, C 3 do little harm on the survival rate of AHH-1 cell, which suggest that C 3 as a novel promising radioprotectant deserve to be further investigated. (author)

Engineered measles virus Edmonston strain used as a novel oncolytic viral system against human hepatoblastoma

International Nuclear Information System (INIS)

Zhang, Shu-Cheng; Wang, Wei-Lin; Cai, Wei-Song; Jiang, Kai-Lei; Yuan, Zheng-Wei

2012-01-01

Hepatoblastoma (HB) is the most common primary, malignant pediatric liver tumor in children. The treatment results for affected children have markedly improved in recent decades. However, the prognosis for high-risk patients who have extrahepatic extensions, invasion of the large hepatic veins, distant metastases and very high alpha-fetoprotein (AFP) serum levels remains poor. There is an urgent need for the development of novel therapeutic approaches. An attenuated strain of measles virus, derived from the Edmonston vaccine lineage, was genetically engineered to produce carcinoembryonic antigen (CEA). We investigated the antitumor potential of this novel viral agent against human HB both in vitro and in vivo. Infection of the Hep2G and HUH6 HB cell lines, at multiplicities of infection (MOIs) ranging from 0.01 to 1, resulted in a significant cytopathic effect consisting of extensive syncytia formation and massive cell death at 72–96 h after infection. Both of the HB lines overexpressed the measles virus receptor CD46 and supported robust viral replication, which correlated with CEA production. The efficacy of this approach in vivo was examined in murine Hep2G xenograft models. Flow cytometry assays indicated an apoptotic mechanism of cell death. Intratumoral administration of MV-CEA resulted in statistically significant delay of tumor growth and prolongation of survival. The engineered measles virus Edmonston strain MV-CEA has potent therapeutic efficacy against HB cell lines and xenografts. Trackable measles virus derivatives merit further exploration in HB treatment

Influence of thyroid hormones and transforming growth factor-β1 on cystatin C concentrations.

Science.gov (United States)

Kotajima, N; Yanagawa, Y; Aoki, T; Tsunekawa, K; Morimura, T; Ogiwara, T; Nara, M; Murakami, M

2010-01-01

Serum cystatin C concentrations are reported to increase in the hyperthyroid state. Serum concentrations of cystatin C and transforming growth factor-β1 (TGF-β1) were measured in patients with thyroid dysfunction, and the effects of 3,5,3'-tri-iodothyronine (T(3)) and TGF-β1 on cystatin C production in human hepatoblastoma (Hep G2) cells were studied. Serum concentrations of cystatin C and TGF-β1 were significantly higher in patients with Graves' disease compared with control subjects. Significantly positive correlations were observed between thyroid hormones and cystatin C, thyroid hormones and TGF-β1, and TGF-β1 and cystatin C in patients with thyroid dysfunction. Serum concentrations of cystatin C and TGF-β1 decreased after treatment for hyperthyroidism. Cystatin C mRNA levels and cystatin C secretion were increased by T(3) and TGF-β1 in cultured Hep G2 cells. These results suggest that serum cystatin C concentrations increase in patients with hyperthyroidism. The mechanisms for this may involve elevation of serum TGF-β1 levels and the stimulatory effects of T(3) and TGF-β1 on cystatin C production.

A Comparison between 18F-FDG PET/CT Imaging and Biological and Radiological Findings in Restaging of Hepatoblastoma Patients

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Angelina Cistaro

2013-01-01

Full Text Available Background. In this study we retrospectively evaluated if 18F-FDG-PET/CT provided incremental diagnostic information over CI in a group of hepatoblastoma patients performing restaging. Procedure. Nine patients (mean age: 5.9 years; range: 3.1–12 years surgically treated for hepatoblastoma were followed up by clinical examination, serum α-FP monitoring, and US. CI (CT or MRI and PET/CT were performed in case of suspicion of relapse. Fine-needle aspiration biopsies (FNAB were carried out for final confirmation if the results of CI, PET/CT, and/or α-FP levels were suggestive of relapse. PET/CT and CI findings were analyzed for comparison purposes, using FNAB as reference standard. Results. α-FP level was suggestive of disease recurrence in 8/9 patients. Biopsy was performed in 8/9 cases. CI and PET/CT resulted to be concordant in 5/9 patients (CI identified recurrence of disease, but 18F-FDG-PET/CT provided a better definition of disease extent; in 4/9 cases, CI diagnostic information resulted in negative findings, whereas PET/CT correctly detected recurrence of disease. 18F-FDG-PET/CT showed an agreement of 100% (8/8 with FNAB results. Conclusions. 18F-FDG-PET/CT scan seems to better assess HB patients with respect to CI and may provide incremental diagnostic value in the restaging of this group of patients.

3-Nitrobenzanthrone and 3-aminobenzanthrone induce DNA damage and cell signalling in Hepa1c1c7 cells.

Science.gov (United States)

Landvik, N E; Arlt, V M; Nagy, E; Solhaug, A; Tekpli, X; Schmeiser, H H; Refsnes, M; Phillips, D H; Lagadic-Gossmann, D; Holme, J A

2010-02-03

3-Nitrobenzanthrone (3-NBA) is a mutagenic and carcinogenic environmental pollutant found in diesel exhaust and urban air pollution. In the present work we have characterised the effects of 3-NBA and its metabolite 3-aminobenzanthrone (3-ABA) on cell death and cytokine release in mouse hepatoma Hepa1c1c7 cells. These effects were related to induced DNA damage and changes in cell signalling pathways. 3-NBA resulted in cell death and caused most DNA damage as judged by the amount of DNA adducts ((32)P-postlabelling assay), single strand (ss)DNA breaks and oxidative DNA lesions (comet assay) detected. An increased phosphorylation of H2AX, chk1, chk2 and partly ATM was observed using flow cytometry and/or Western blotting. Both compounds increased phosphorylation of p53 and MAPKs (ERK, p38 and JNK). However, only 3-NBA caused an accumulation of p53 in the nucleus and a translocation of Bax to the mitochondria. The p53 inhibitor pifithrin-alpha inhibited 3-NBA-induced apoptosis, indicating that cell death was a result of the triggering of DNA signalling pathways. The highest phosphorylation of Akt and degradation of IkappaB-alpha (suggesting activation of NF-kappaB) were also seen after treatment with 3-NBA. In contrast 3-ABA increased IL-6 release, but caused little or no toxicity. Cytokine release was inhibited by PD98059 and curcumin, suggesting that ERK and NF-kappaB play a role in this process. In conclusion, 3-NBA seems to have a higher potency to induce DNA damage compatible with its cytotoxic effects, while 3-ABA seems to have a greater effect on the immune system. Copyright 2009 Elsevier B.V. All rights reserved.

3-Nitrobenzanthrone and 3-aminobenzanthrone induce DNA damage and cell signalling in Hepa1c1c7 cells

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Landvik, N.E. [Division of Environmental Medicine, Norwegian Institute of Public Health, P.O. Box 404 Torshov N-4303 Oslo (Norway); Arlt, V.M.; Nagy, E. [Section of Molecular Carcinogenesis, Institute of Cancer Research, Brookes Lawley Building, Sutton, Surrey SM2 5NG (United Kingdom); Solhaug, A. [Section for Toxicology, Department of Feed and Food Safety, National Veterinary Institute Pb 750 Sentrum, N-0106 Oslo (Norway); Tekpli, X. [EA SeRAIC, Equipe labellisee Ligue contre le Cancer, IFR 140, Universite de Rennes 1, Rennes (France); Schmeiser, H.H. [Research Group Genetic Alteration in Carcinogenesis, German Cancer Research Center, Im Neuenheimer Feld 280, 69120 Heidelberg (Germany); Refsnes, M. [Division of Environmental Medicine, Norwegian Institute of Public Health, P.O. Box 404 Torshov N-4303 Oslo (Norway); Phillips, D.H. [Section of Molecular Carcinogenesis, Institute of Cancer Research, Brookes Lawley Building, Sutton, Surrey SM2 5NG (United Kingdom); Lagadic-Gossmann, D. [EA SeRAIC, Equipe labellisee Ligue contre le Cancer, IFR 140, Universite de Rennes 1, Rennes (France); Holme, J.A., E-mail: jorn.holme@fhi.no [Division of Environmental Medicine, Norwegian Institute of Public Health, P.O. Box 404 Torshov N-4303 Oslo (Norway)

2010-02-03

3-Nitrobenzanthrone (3-NBA) is a mutagenic and carcinogenic environmental pollutant found in diesel exhaust and urban air pollution. In the present work we have characterised the effects of 3-NBA and its metabolite 3-aminobenzanthrone (3-ABA) on cell death and cytokine release in mouse hepatoma Hepa1c1c7 cells. These effects were related to induced DNA damage and changes in cell signalling pathways. 3-NBA resulted in cell death and caused most DNA damage as judged by the amount of DNA adducts ({sup 32}P-postlabelling assay), single strand (ss)DNA breaks and oxidative DNA lesions (comet assay) detected. An increased phosphorylation of H2AX, chk1, chk2 and partly ATM was observed using flow cytometry and/or Western blotting. Both compounds increased phosphorylation of p53 and MAPKs (ERK, p38 and JNK). However, only 3-NBA caused an accumulation of p53 in the nucleus and a translocation of Bax to the mitochondria. The p53 inhibitor pifithrin-alpha inhibited 3-NBA-induced apoptosis, indicating that cell death was a result of the triggering of DNA signalling pathways. The highest phosphorylation of Akt and degradation of I{kappa}B-{alpha} (suggesting activation of NF-{kappa}B) were also seen after treatment with 3-NBA. In contrast 3-ABA increased IL-6 release, but caused little or no toxicity. Cytokine release was inhibited by PD98059 and curcumin, suggesting that ERK and NF-{kappa}B play a role in this process. In conclusion, 3-NBA seems to have a higher potency to induce DNA damage compatible with its cytotoxic effects, while 3-ABA seems to have a greater effect on the immune system.

A Challenging Case of Hepatoblastoma Concomitant with Autosomal Recessive Polycystic Kidney Disease and Caroli Syndrome—Review of the Literature

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Nevil Kadakia

2017-06-01

Full Text Available We report a rare case of an 18-month-old female with autosomal recessive polycystic kidney disease, Caroli syndrome, and pure fetal type hepatoblastoma. The liver tumor was surgically resected with no chemotherapy given. Now 9 years post resection she demonstrates no local or distant recurrence and stable renal function.

A ginseng saponin metabolite-induced apoptosis in HepG2 cells involves a mitochondria-mediated pathway and its downstream caspase-8 activation and Bid cleavage

International Nuclear Information System (INIS)

Oh, Seon-Hee; Lee, Byung-Hoon

2004-01-01

20-O-(β-D-Glucopyranosyl)-20(S)-protopanaxadiol (IH901), an intestinal bacterial metabolite of ginseng saponin formed from ginsenosides Rb1, Rb2, and Rc, is suggested to be a potential chemopreventive agent. Here, we show that IH901 induces apoptosis in human hepatoblastoma HepG2 cells. IH901 led to an early activation of procaspase-3 (12 h posttreatment), and the activation of caspase-8 became evident only later (18 h posttreatment). Caspase activation was a necessary requirement for apoptosis because caspase inhibitors significantly inhibited cell death by IH901. Treatment of HepG2 cells with IH901 also induced the cleavage of cytosolic factors such as Bid and Bax and translocation of truncated Bid (tBid) to mitochondria. A time-dependent release of cytochrome c from mitochondria was observed, which was accompanied by activation of caspase-9. A broad-spectrum caspase inhibitor, N-benzyloxycarbonyl-Val-Ala-Asp-fluoromethylketone (zVAD-fmk), and a specific inhibitor for caspase-8, N-benzyloxycarbonyl-Ile-Glu-Thr-Asp-fluoromethylketone (zIETD-fmk), abrogated Bid processing and translocation, and caspase-3 activation. Cytochrome c release was inhibited by zVAD-fmk, however, the inhibition by zIETD-fmk was not complete. The activation of caspase-8 was inhibited not only by zIETD-fmk but also by zVAD-fmk. The results, together with the kinetic change of caspase activation, indicate that activation of caspase-8 occurred downstream of caspase-3 and -9. Our data suggest that the activation of caspase-8 after early caspase-3 activation might act as an amplification loop necessary for successful apoptosis. Primary hepatocytes isolated from normal Sprague-Dawley rats were not affected by IH901 (0-60 μM). The very low toxicity in normal hepatocytes and high activity in hepatoblastoma HepG2 cells suggest that IH901 is a promising experimental cancer chemopreventive agent

C3 rho-inhibitor for targeted pharmacological manipulation of osteoclast-like cells.

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Andrea Tautzenberger

Full Text Available The C3 toxins from Clostridium botulinum (C3bot and Clostridium limosum (C3lim as well as C3-derived fusion proteins are selectively taken up into the cytosol of monocytes/macrophages where the C3-catalyzed ADP-ribosylation of Rho results in inhibition of Rho-signalling and characteristic morphological changes. Since the fusion toxin C2IN-C3lim was efficiently taken up into and inhibited proliferation of murine macrophage-like RAW 264.7 cells, its effects on RAW 264.7-derived osteoclasts were investigated. C2IN-C3lim was taken up into differentiated osteoclasts and decreased their resorption activity. In undifferentiated RAW 264.7 cells, C2IN-C3lim-treatment significantly decreased their differentiation into osteoclasts as determined by counting the multi-nucleated, TRAP-positive cells. This inhibitory effect was concentration- and time-dependent and most efficient when C2IN-C3lim was applied in the early stage of osteoclast-formation. A single-dose application of C2IN-C3lim at day 0 and its subsequent removal at day 1 reduced the number of osteoclasts in a comparable manner while C2IN-C3lim-application at later time points did not reduce the number of osteoclasts to a comparable degree. Control experiments with an enzymatically inactive C3 protein revealed that the ADP-ribosylation of Rho was essential for the observed effects. In conclusion, the results indicate that Rho-activity is crucial during the early phase of osteoclast-differentiation. Other bone cell types such as pre-osteoblastic cells were not affected by C2IN-C3lim. Due to their cell-type selective and specific mode of action, C3 proteins and C3-fusions might be valuable tools for targeted pharmacological manipulation of osteoclast formation and activity, which could lead to development of novel therapeutic strategies against osteoclast-associated diseases.

ClC-3 Promotes Osteogenic Differentiation in MC3T3-E1 Cell After Dynamic Compression.

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Wang, Dawei; Wang, Hao; Gao, Feng; Wang, Kun; Dong, Fusheng

2017-06-01

ClC-3 chloride channel has been proved to have a relationship with the expression of osteogenic markers during osteogenesis, persistent static compression can upregulate the expression of ClC-3 and regulate osteodifferentiation in osteoblasts. However, there was no study about the relationship between the expression of ClC-3 and osteodifferentiation after dynamic compression. In this study, we applied dynamic compression on MC3T3-E1 cells to detect the expression of ClC-3, runt-related transcription factor 2 (Runx2), bone morphogenic protein-2 (BMP-2), osteopontin (OPN), nuclear-associated antigen Ki67 (Ki67), and proliferating cell nuclear antigen (PCNA) in biopress system, then we investigated the expression of these genes after dynamic compression with Chlorotoxin (specific ClC-3 chloride channel inhibitor) added. Under transmission electron microscopy, there were more cell surface protrusions, rough surfaced endoplasmic reticulum, mitochondria, Golgi apparatus, abundant glycogen, and lysosomes scattered in the cytoplasm in MC3T3-E1 cells after dynamic compression. The nucleolus was more obvious. We found that ClC-3 was significantly up-regulated after dynamic compression. The compressive force also up-regulated Runx2, BMP-2, and OPN after dynamic compression for 2, 4 and 8 h. The proliferation gene Ki67 and PCNA did not show significantly change after dynamic compression for 8 h. Chlorotoxin did not change the expression of ClC-3 but reduced the expression of Runx2, BMP-2, and OPN after dynamic compression compared with the group without Cltx added. The data from the current study suggested that ClC-3 may promotes osteogenic differentiation in MC3T3-E1 cell after dynamic compression. J. Cell. Biochem. 118: 1606-1613, 2017. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

Cell culture system of a hepatitis C genotype 3a and 2a chimera

DEFF Research Database (Denmark)

2015-01-01

A robust and genetically stable cell culture system for Hepatitis C Virus (HCV) genotype 3a is provided. A genotype 3a/2a (S52/JFH1) recombinant containing the structural genes (Core, E1, E2), p7 and NS2 of strain S52 was constructed and characterized in Huh7.5 cells. S52/JFH1 and J6/JFH viruses ...

Germline APC mutations in hepatoblastoma.

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Yang, Adeline; Sisson, Rebecca; Gupta, Anita; Tiao, Greg; Geller, James I

2018-04-01

Conflicting reports on the frequency of germline adenomatous polyposis coli (APC) gene mutations in patients with hepatoblastoma (HB) have called into question the clinical value of APC mutation testing on apparently sporadic HB. An Institutional Review Board approved retrospective review of clinical data collected from patients with HB who received APC testing at our institution was conducted. All HB patients seen at Cincinnati Children's Hospital Medical Center were eligible for testing. Potential genotype/phenotype correlations were assessed. As of July 2015, 29 patients with HB had received constitutional APC testing. Four (14%) were found to have APC pathogenic truncations of the APC protein and in addition two (7%) had APC missense variants of unknown clinical significance. Two patients (7%) had family histories indicative of familial adenomatous polyposis (FAP). Response to chemotherapy tracked differently in APC pathogenic cases, with a slower imaging response despite an equivalent or slightly faster α-fetoprotein (AFP) response. The prevalence of pathogenic APC variants in apparently sporadic HB may be higher than previously detected. Differences in time to imaging response, despite similar AFP response, may impact surgical planning. All patients with HB warrant germline APC mutation testing for underlying FAP. © 2017 Wiley Periodicals, Inc.

The Rho ADP-ribosylating C3 exoenzyme binds cells via an Arg-Gly-Asp motif.

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Rohrbeck, Astrid; Höltje, Markus; Adolf, Andrej; Oms, Elisabeth; Hagemann, Sandra; Ahnert-Hilger, Gudrun; Just, Ingo

2017-10-27

The Rho ADP-ribosylating C3 exoenzyme (C3bot) is a bacterial protein toxin devoid of a cell-binding or -translocation domain. Nevertheless, C3 can efficiently enter intact cells, including neurons, but the mechanism of C3 binding and uptake is not yet understood. Previously, we identified the intermediate filament vimentin as an extracellular membranous interaction partner of C3. However, uptake of C3 into cells still occurs (although reduced) in the absence of vimentin, indicating involvement of an additional host cell receptor. C3 harbors an Arg-Gly-Asp (RGD) motif, which is the major integrin-binding site, present in a variety of integrin ligands. To check whether the RGD motif of C3 is involved in binding to cells, we performed a competition assay with C3 and RGD peptide or with a monoclonal antibody binding to β1-integrin subunit and binding assays in different cell lines, primary neurons, and synaptosomes with C3-RGD mutants. Here, we report that preincubation of cells with the GRGDNP peptide strongly reduced C3 binding to cells. Moreover, mutation of the RGD motif reduced C3 binding to intact cells and also to recombinant vimentin. Anti-integrin antibodies also lowered the C3 binding to cells. Our results indicate that the RGD motif of C3 is at least one essential C3 motif for binding to host cells and that integrin is an additional receptor for C3 besides vimentin. © 2017 by The American Society for Biochemistry and Molecular Biology, Inc.

Absence of PDGF-induced, PKC-independent c-fos expression in a chemically transformed C3H/10T1/2 cell clone.

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Vassbotn, F S; Skar, R; Holmsen, H; Lillehaug, J R

1992-09-01

The effect of platelet-derived growth factor (PDGF) on c-fos mRNA transcription was studied in the immortalized mouse embryo fibroblast C3H/10T1/2 Cl 8 (10T1/2) cells and the chemically transformed, tumorigenic subclone C3H/10T1/2 Cl 16 (Cl 16). In the 10T1/2 cells as well as the Cl 16 subclone, the dose-dependent PDGF stimulation of c-fos mRNA synthesis was similar in both logarithmically growing and confluent cultures. c-fos mRNA was induced severalfold by 12-O-tetradecanoylphorbol-13-acetate (TPA) in both 10T1/2 and Cl 16. Down-regulation of protein kinase C (PKC) activity by TPA pretreatment inhibited PDGF-stimulated c-fos mRNA expression in Cl 16 cells but did not affect this induction in the 10T1/2 cells. This inhibition was not a general phenomenon of 3-methylcholanthrene-mediated transformation of 10T1/2 cells since experiments with another transformed 10T1/2 cell clone, C3H/10T1/2 TPA 482, gave qualitatively the same results as the 10T1/2 cells. Receptor binding experiments showed that the nontransformed and transformed cells had a comparable number of PDGF receptors, 1.3 x 10(5) and 0.7 x 10(5) receptors per cell, respectively. Furthermore, cAMP-induced c-fos expression induced by forskolin is formerly shown to be independent of PKC down-regulation. In our experiments, forskolin induced c-fos expression in both clones. However, PKC down-regulation inhibited the forskolin-induced c-fos expression in Cl 16 cells. This apparently demonstrates cross talk between PKC and PKA in the c-fos induction pathway. The present results provide evidence for an impaired mechanism for activating c-fos expression through PKC-independent, PDGF-induced signal transduction in the chemically transformed Cl 16 fibroblasts compared to that in nontransformed 10T1/2 cells.

C/EBPβ Promotes STAT3 Expression and Affects Cell Apoptosis and Proliferation in Porcine Ovarian Granulosa Cells.

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Yuan, Xiaolong; Zhou, Xiaofeng; He, Yingting; Zhong, Yuyi; Zhang, Ailing; Zhang, Zhe; Zhang, Hao; Li, Jiaqi

2018-06-13

Previous studies suggest that signal transducer and activator of transcription 3 (STAT3) and CCAAT/enhancer binding protein beta (C/EBPβ) play an essential role in ovarian granulosa cells (GCs) for mammalian follicular development. Several C/EBPβ putative binding sites were previously predicted on the STAT3 promoter in mammals. However, the molecular regulation of C/EBPβ on STAT3 and their effects on cell proliferation and apoptosis remain virtually unexplored in GCs. Using porcine GCs as a model, the 5′-deletion, luciferase report assay, mutation, chromatin immunoprecipitation, Annexin-V/PI staining and EdU assays were applied to investigate the molecular mechanism for C/EBPβ regulating the expression of STAT3 and their effects on the cell proliferation and apoptosis ability. We found that over and interfering with the expression of C/EBPβ significantly increased and decreased the messenger RNA (mRNA) and protein levels of STAT3 , respectively. The dual luciferase reporter assay showed that C/EBPβ directly bound at −1397/−1387 of STAT3 to positively regulate the mRNA and protein expressions of STAT3 . Both C/EBPβ and STAT3 were observed to inhibit cell apoptosis and promote cell proliferation. Furthermore, C/EBPβ might enhance the antiapoptotic and pro-proliferative effects of STAT3 . These results would be of great insight in further exploring the molecular mechanism of C/EBPβ and STAT3 on the function of GCs and the development of ovarian follicles in mammals.

Selecting Cells for Bioartificial Liver Devices and the Importance of a 3D Culture Environment: A Functional Comparison between the HepaRG and C3A Cell Lines.

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van Wenum, Martien; Adam, Aziza A A; Hakvoort, Theodorus B M; Hendriks, Erik J; Shevchenko, Valery; van Gulik, Thomas M; Chamuleau, Robert A F M; Hoekstra, Ruurdtje

2016-01-01

Recently, the first clinical trials on Bioartificial Livers (BALs) loaded with a proliferative human hepatocyte cell source have started. There are two cell lines that are currently in an advanced state of BAL development; HepaRG and HepG2/C3A. In this study we aimed to compare both cell lines on applicability in BALs and to identify possible strategies for further improvement. We tested both cell lines in monolayer- and BAL cultures on growth characteristics, hepatic differentiation, nitrogen-, carbohydrate-, amino acid- and xenobiotic metabolism. Interestingly, both cell lines adapted the hepatocyte phenotype more closely when cultured in BALs; e.g. monolayer cultures produced lactate, while BAL cultures showed diminished lactate production (C3A) or conversion to elimination (HepaRG), and urea cycle activity increased upon BAL culturing in both cell lines. HepaRG-BALs outperformed C3A-BALs on xenobiotic metabolism, ammonia elimination and lactate elimination, while protein synthesis was comparable. In BAL cultures of both cell lines ammonia elimination correlated positively with glutamine production and glutamate consumption, suggesting ammonia elimination was mainly driven by the balance between glutaminase and glutamine synthetase activity. Both cell lines lacked significant urea cycle activity and both required multiple culture weeks before reaching optimal differentiation in BALs. In conclusion, culturing in BALs enhanced hepatic functionality of both cell lines and from these, the HepaRG cells are the most promising proliferative cell source for BAL application.

Palbociclib in Treating Patients With Relapsed or Refractory Rb Positive Advanced Solid Tumors, Non-Hodgkin Lymphoma, or Histiocytic Disorders With Activating Alterations in Cell Cycle Genes (A Pediatric MATCH Treatment Trial)

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2018-05-15

Advanced Malignant Solid Neoplasm; RB1 Positive; Recurrent Childhood Ependymoma; Recurrent Ewing Sarcoma; Recurrent Glioma; Recurrent Hepatoblastoma; Recurrent Kidney Wilms Tumor; Recurrent Langerhans Cell Histiocytosis; Recurrent Malignant Germ Cell Tumor; Recurrent Malignant Glioma; Recurrent Medulloblastoma; Recurrent Neuroblastoma; Recurrent Non-Hodgkin Lymphoma; Recurrent Osteosarcoma; Recurrent Peripheral Primitive Neuroectodermal Tumor; Recurrent Rhabdoid Tumor; Recurrent Rhabdomyosarcoma; Recurrent Soft Tissue Sarcoma; Refractory Ependymoma; Refractory Ewing Sarcoma; Refractory Glioma; Refractory Hepatoblastoma; Refractory Langerhans Cell Histiocytosis; Refractory Malignant Germ Cell Tumor; Refractory Malignant Glioma; Refractory Medulloblastoma; Refractory Neuroblastoma; Refractory Non-Hodgkin Lymphoma; Refractory Osteosarcoma; Refractory Peripheral Primitive Neuroectodermal Tumor; Refractory Rhabdoid Tumor; Refractory Rhabdomyosarcoma; Refractory Soft Tissue Sarcoma

Schwann Cells Metabolize Extracellular 2′,3′-cAMP to 2′-AMP

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Verrier, Jonathan D.; Kochanek, Patrick M.

2015-01-01

The 3′,5′-cAMP–adenosine pathway (3′,5′-cAMP→5′-AMP→adenosine) and the 2′,3′-cAMP–adenosine pathway (2′,3′-cAMP→2′-AMP/3′-AMP→adenosine) are active in the brain. Oligodendrocytes participate in the brain 2′,3′-cAMP–adenosine pathway via their robust expression of 2′,3′-cyclic nucleotide 3′-phosphodiesterase (CNPase; converts 2′,3′-cAMP to 2′-AMP). Because Schwann cells also express CNPase, it is conceivable that the 2′,3′-cAMP–adenosine pathway exists in the peripheral nervous system. To test this and to compare the 2′,3′-cAMP–adenosine pathway to the 3′,5′-cAMP–adenosine pathway in Schwann cells, we examined the metabolism of 2′,3′-cAMP, 2′-AMP, 3′-AMP, 3′,5′-cAMP, and 5′-AMP in primary rat Schwann cells in culture. Addition of 2′,3′-cAMP (3, 10, and 30 µM) to Schwann cells increased levels of 2′-AMP in the medium from 0.006 ± 0.002 to 21 ± 2, 70 ± 3, and 187 ± 10 nM/µg protein, respectively; in contrast, Schwann cells had little ability to convert 2′,3′-cAMP to 3′-AMP or 3′,5′-cAMP to either 3′-AMP or 5′-AMP. Although Schwann cells slightly converted 2′,3′-cAMP and 2′-AMP to adenosine, they did so at very modest rates (e.g., 5- and 3-fold, respectively, more slowly compared with our previously reported studies in oligodendrocytes). Using transected myelinated rat sciatic nerves in culture medium, we observed a time-related increase in endogenous intracellular 2′,3′-cAMP and extracellular 2′-AMP. These findings indicate that Schwann cells do not have a robust 3′,5′-cAMP–adenosine pathway but do have a 2′,3′-cAMP–adenosine pathway; however, because the pathway mostly involves 2′-AMP formation rather than 3′-AMP, and because the conversion of 2′-AMP to adenosine is slow, metabolism of 2′,3′-cAMP mostly results in the accumulation of 2′-AMP. Accumulation of 2′-AMP in peripheral nerves postinjury could have

Vitamin C induces specific demethylation of H3K9me2 in mouse embryonic stem cells via Kdm3a/b.

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Ebata, Kevin T; Mesh, Kathryn; Liu, Shichong; Bilenky, Misha; Fekete, Alexander; Acker, Michael G; Hirst, Martin; Garcia, Benjamin A; Ramalho-Santos, Miguel

2017-01-01

Histone methylation patterns regulate gene expression and are highly dynamic during development. The erasure of histone methylation is carried out by histone demethylase enzymes. We had previously shown that vitamin C enhances the activity of Tet enzymes in embryonic stem (ES) cells, leading to DNA demethylation and activation of germline genes. We report here that vitamin C induces a remarkably specific demethylation of histone H3 lysine 9 dimethylation (H3K9me2) in naïve ES cells. Vitamin C treatment reduces global levels of H3K9me2, but not other histone methylation marks analyzed, as measured by western blot, immunofluorescence and mass spectrometry. Vitamin C leads to widespread loss of H3K9me2 at large chromosomal domains as well as gene promoters and repeat elements. Vitamin C-induced loss of H3K9me2 occurs rapidly within 24 h and is reversible. Importantly, we found that the histone demethylases Kdm3a and Kdm3b are required for vitamin C-induced demethylation of H3K9me2. Moreover, we show that vitamin C-induced Kdm3a/b-mediated H3K9me2 demethylation and Tet-mediated DNA demethylation are independent processes at specific loci. Lastly, we document Kdm3a/b are partially required for the upregulation of germline genes by vitamin C. These results reveal a specific role for vitamin C in histone demethylation in ES cells and document that DNA methylation and H3K9me2 cooperate to silence germline genes in pluripotent cells.

The novel protein C9orf116 promotes rat liver cell line BRL-3A proliferation.

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Chunyan Zhang

Full Text Available Our previous study has proved that the chromosome 9 open reading frame 116 (C9orf116 (NM_001106564.1 was significantly up-regulated in the proliferation phase of liver regeneration. To study its possible physiological function, we analyzed the effect of C9orf116 on BRL-3A cells via over-expression and interference technique. MTT results showed that the cell viability of the interference group was significantly lower than the control group at 48h after transfection (P<0.05, whereas it was significantly higher in the over-expression group (P<0.05. The flow cytometry results showed that C9orf116 knockdown or over-expression had little effect on BRL-3A cell apoptosis. However, the number of cells in division phase (G2/M was significantly reduced in the interference group (P<0.05, but significantly increased in the over-expression group (P<0.01. Furthermore, the expressions of cell proliferation-related genes CCNA2, CCND1 and MYC both at mRNA and protein levels were down-regulated in the interference group and up-regulated in the over-expression group. Therefore, we concluded that C9orf116 may promote cell proliferation by modulating cell cycle transition and the expression of key genes CCNA2, CCND1 and MYC in BRL-3A cells.

3D material cytometry (3DMaC): a very high-replicate, high-throughput analytical method using microfabricated, shape-specific, cell-material niches.

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Parratt, Kirsten; Jeong, Jenny; Qiu, Peng; Roy, Krishnendu

2017-08-08

Studying cell behavior within 3D material niches is key to understanding cell biology in health and diseases, and developing biomaterials for regenerative medicine applications. Current approaches to studying these cell-material niches have low throughput and can only analyze a few replicates per experiment resulting in reduced measurement assurance and analytical power. Here, we report 3D material cytometry (3DMaC), a novel high-throughput method based on microfabricated, shape-specific 3D cell-material niches and imaging cytometry. 3DMaC achieves rapid and highly multiplexed analyses of very high replicate numbers ("n" of 10 4 -10 6 ) of 3D biomaterial constructs. 3DMaC overcomes current limitations of low "n", low-throughput, and "noisy" assays, to provide rapid and simultaneous analyses of potentially hundreds of parameters in 3D biomaterial cultures. The method is demonstrated here for a set of 85 000 events containing twelve distinct cell-biomaterial micro-niches along with robust, customized computational methods for high-throughput analytics with potentially unprecedented statistical power.

Novel derivative of aminobenzenesulfonamide (3c) induces apoptosis in colorectal cancer cells through ROS generation and inhibits cell migration.

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Al-Khayal, Khayal; Alafeefy, Ahmed; Vaali-Mohammed, Mansoor-Ali; Mahmood, Amer; Zubaidi, Ahmed; Al-Obeed, Omar; Khan, Zahid; Abdulla, Maha; Ahmad, Rehan

2017-01-03

Colorectal cancer (CRC) is the 3 rd most common type of cancer worldwide. New anti-cancer agents are needed for treating late stage colorectal cancer as most of the deaths occur due to cancer metastasis. A recently developed compound, 3c has shown to have potent antitumor effect; however the mechanism underlying the antitumor effect remains unknown. 3c-induced inhibition of proliferation was measured in the absence and presence NAC using MTT in HT-29 and SW620 cells and xCELLigence RTCA DP instrument. 3c-induced apoptotic studies were performed using flow cytometry. 3c-induced redox alterations were measured by ROS production using fluorescence plate reader and flow cytometry and mitochondrial membrane potential by flow cytometry; NADPH and GSH levels were determined by colorimetric assays. Bcl2 family protein expression and cytochrome c release and PARP activation was done by western blotting. Caspase activation was measured by ELISA. Cell migration assay was done using the real time xCELLigence RTCA DP system in SW620 cells and wound healing assay in HT-29. Many anticancer therapeutics exert their effects by inducing reactive oxygen species (ROS). In this study, we demonstrate that 3c-induced inhibition of cell proliferation is reversed by the antioxidant, N-acetylcysteine, suggesting that 3c acts via increased production of ROS in HT-29 cells. This was confirmed by the direct measurement of ROS in 3c-treated colorectal cancer cells. Additionally, treatment with 3c resulted in decreased NADPH and glutathione levels in HT-29 cells. Further, investigation of the apoptotic pathway showed increased release of cytochrome c resulting in the activation of caspase-9, which in turn activated caspase-3 and -6. 3c also (i) increased p53 and Bax expression, (ii) decreased Bcl2 and BclxL expression and (iii) induced PARP cleavage in human colorectal cancer cells. Confirming our observations, NAC significantly inhibited induction of apoptosis, ROS production, cytochrome c

Cells for bioartificial liver devices: the human hepatoma-derived cell line C3A produces urea but does not detoxify ammonia.

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Mavri-Damelin, Demetra; Damelin, Leonard H; Eaton, Simon; Rees, Myrddin; Selden, Clare; Hodgson, Humphrey J F

2008-02-15

Extrahepatic bioartificial liver devices should provide an intact urea cycle to detoxify ammonia. The C3A cell line, a subclone of the hepatoma-derived HepG2 cell line, is currently used in this context as it produces urea, and this has been assumed to be reflective of ammonia detoxification via a functional urea cycle. However, based on our previous findings of perturbed urea-cycle function in the non-urea producing HepG2 cell line, we hypothesized that the urea produced by C3A cells was via a urea cycle-independent mechanism, namely, due to arginase II activity, and therefore would not detoxify ammonia. Urea was quantified using (15)N-ammonium chloride metabolic labelling with gas chromatography-mass spectrometry. Gene expression was determined by real-time reverse transcriptase-PCR, protein expression by western blotting, and functional activities with radiolabelling enzyme assays. Arginase inhibition studies used N(omega)-hydroxy-nor-L-arginine. Urea was detected in C3A conditioned medium; however, (15)N-ammonium chloride-labelling indicated that (15)N-ammonia was not incorporated into (15)N-labelled urea. Further, gene expression of two urea cycle genes, ornithine transcarbamylase and arginase I, were completely absent. In contrast, arginase II mRNA and protein was expressed at high levels in C3A cells and was inhibited by N(omega)-hydroxy-nor-L-arginine, which prevented urea production, thereby indicating a urea cycle-independent pathway. The urea cycle is non-functional in C3A cells, and their urea production is solely due to the presence of arginase II, which therefore cannot provide ammonia detoxification in a bioartificial liver system. This emphasizes the continued requirement for developing a component capable of a full repertoire of liver function. (c) 2007 Wiley Periodicals, Inc.

Tiamulin inhibits human CYP3A4 activity in an NIH/3T3 cell line stably expressing CYP3A4 cDNA.

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De Groene, E M; Nijmeijer, S M; Horbach, G J; Witkamp, R F

1995-09-07

Tiamulin is an antibiotic frequently used in veterinary medicine. The drug has been shown to produce clinically important interactions with other compounds that are administered simultaneously. An NIH/3T3 cell line, stably expressing human cytochrome P450 (EC 1.14.14.1) cDNA (CYP3A4), was used to study the effect of tiamulin on CYP3A4 activity. The 6 beta-hydroxylation activity of testosterone, which is increased in CYP3A4-expressing cells compared to vector-transfected cells, showed reduced activity after incubation with 1 microM tiamulin and was completely reduced to background level after incubation with 2, 5 and 10 microM tiamulin. The CYP3A4-expressing cell line was used in combination with a shuttle vector containing the bacterial lacZ' gene to study the effect of tiamulin on CYP3A4-mediated mutagenicity of aflatoxin B1. The mutation frequency of aflatoxin B1 could be completely inhibited by tiamulin in CYP3A4-expressing cells, but no effect was observed on the mutation frequency of the direct mutagen ethylmethanesulphonate. Western blotting of homogenates of the CYP3A4-expressing cell line showed stabilization of CYP3A4 protein after incubation with tiamulin, supporting the hypothesis that the mechanism of inhibition is by binding of tiamulin to the cytochrome.

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.

Rip3 knockdown rescues photoreceptor cell death in blind pde6c zebrafish.

Science.gov (United States)

Viringipurampeer, I A; Shan, X; Gregory-Evans, K; Zhang, J P; Mohammadi, Z; Gregory-Evans, C Y

2014-05-01

Achromatopsia is a progressive autosomal recessive retinal disease characterized by early loss of cone photoreceptors and later rod photoreceptor loss. In most cases, mutations have been identified in CNGA3, CNGB3, GNAT2, PDE6C or PDE6H genes. Owing to this genetic heterogeneity, mutation-independent therapeutic schemes aimed at preventing cone cell death are very attractive treatment strategies. In pde6c(w59) mutant zebrafish, cone photoreceptors expressed high levels of receptor-interacting protein kinase 1 (RIP1) and receptor-interacting protein kinase 3 (RIP3) kinases, key regulators of necroptotic cell death. In contrast, rod photoreceptor cells were alternatively immunopositive for caspase-3 indicating activation of caspase-dependent apoptosis in these cells. Morpholino gene knockdown of rip3 in pde6c(w59) embryos rescued the dying cone photoreceptors by inhibiting the formation of reactive oxygen species and by inhibiting second-order neuron remodelling in the inner retina. In rip3 morphant larvae, visual function was restored in the cones by upregulation of the rod phosphodiesterase genes (pde6a and pde6b), compensating for the lack of cone pde6c suggesting that cones are able to adapt to their local environment. Furthermore, we demonstrated through pharmacological inhibition of RIP1 and RIP3 activity that cone cell death was also delayed. Collectively, these results demonstrate that the underlying mechanism of cone cell death in the pde6c(w59) mutant retina is through necroptosis, whereas rod photoreceptor bystander death occurs through a caspase-dependent mechanism. This suggests that targeting the RIP kinase signalling pathway could be an effective therapeutic intervention in retinal degeneration patients. As bystander cell death is an important feature of many retinal diseases, combinatorial approaches targeting different cell death pathways may evolve as an important general principle in treatment.

Elevated AKR1C3 expression promotes prostate cancer cell survival and prostate cell-mediated endothelial cell tube formation: implications for prostate cancer progressioan

International Nuclear Information System (INIS)

Dozmorov, Mikhail G; Lin, Hsueh-Kung; Azzarello, Joseph T; Wren, Jonathan D; Fung, Kar-Ming; Yang, Qing; Davis, Jeffrey S; Hurst, Robert E; Culkin, Daniel J; Penning, Trevor M

2010-01-01

Aldo-keto reductase (AKR) 1C family member 3 (AKR1C3), one of four identified human AKR1C enzymes, catalyzes steroid, prostaglandin, and xenobiotic metabolism. In the prostate, AKR1C3 is up-regulated in localized and advanced prostate adenocarcinoma, and is associated with prostate cancer (PCa) aggressiveness. Here we propose a novel pathological function of AKR1C3 in tumor angiogenesis and its potential role in promoting PCa progression. To recapitulate elevated AKR1C3 expression in cancerous prostate, the human PCa PC-3 cell line was stably transfected with an AKR1C3 expression construct to establish PC3-AKR1C3 transfectants. Microarray and bioinformatics analysis were performed to identify AKR1C3-mediated pathways of activation and their potential biological consequences in PC-3 cells. Western blot analysis, reverse transcription-polymerase chain reaction (RT-PCR), enzyme-linked immunosorbent assay (ELISA), and an in vitro Matrigel angiogenesis assays were applied to validate the pro-angiogenic activity of PC3-AKR1C3 transfectants identified by bioinformatics analysis. Microarray and bioinformatics analysis suggested that overexpression of AKR1C3 in PC-3 cells modulates estrogen and androgen metabolism, activates insulin-like growth factor (IGF)-1 and Akt signaling pathways, as well as promotes tumor angiogenesis and aggressiveness. Levels of IGF-1 receptor (IGF-1R) and Akt activation as well as vascular endothelial growth factor (VEGF) expression and secretion were significantly elevated in PC3-AKR1C3 transfectants in comparison to PC3-mock transfectants. PC3-AKR1C3 transfectants also promoted endothelial cell (EC) tube formation on Matrigel as compared to the AKR1C3-negative parental PC-3 cells and PC3-mock transfectants. Pre-treatment of PC3-AKR1C3 transfectants with a selective IGF-1R kinase inhibitor (AG1024) or a non-selective phosphoinositide 3-kinases (PI3K) inhibitor (LY294002) abolished ability of the cells to promote EC tube formation. Bioinformatics

Microscopic Aspects of Autoschizic Cell Death in Human Ovarian Carcinoma (2774) Cells Following Vitamin C, Vitamin K3 or Vitamin C:K3 Treatment

Science.gov (United States)

Gilloteaux, Jacques; Jamison, James M.; Arnold, David; Taper, Henryk S.; von Gruenigen, Vivian E.; Summers, Jack L.

2003-08-01

Human ovarian carcinoma cells (MDAH 2774) were treated with sodium ascorbate (VC), menadione (VK3), or with a VC:VK3 combination for 1 h and then studied using light microscopy (LM) and scanning (SEM) and transmission electron (TEM) microscopy. Plasma membrane damage (blisters and blebs, hairy aspect) results from vitamin C (VC) treatment, while cytoskeletal damage and self-morsellation are caused by vitamin K3 (VK3) treatment. VC:VK3-treated cells exhibit exacerbated injuries characteristic of both VC and VK3 treatment as well as a significant decrease in cell diameters from 20 35 [mu]m for control cells to 7 12 [mu]m for VC:VK3 treatment. Moreover, after a 1-h exposure to the vitamin combination, autoschizis (43%), apoptosis (3%), and oncosis (1.9%) are observed at the percentages indicated. All cellular changes associated with autoschizis observed with SEM were confirmed by LM and TEM observations and are consistent with cell death by autoschizis: decrease in cell size, cytoplasmic self-excisions, degradation of the nucleus and nucleolus without formation of apoptotic bodies and, ultimately, karyorrhexis and karyolysis. These results also suggest that the vitamin combination may find clinical use in the treatment of ovarian cancer.

Method for combined 3H and 14C autoradiography with a single emulsion tested in cultured mammalian cells

International Nuclear Information System (INIS)

Perdue, S.W.; Kimball, R.F.; Hsie, A.W.

1977-01-01

A single-gelatin expanded film method for double-isotope autoradiography is described. A preliminary classification based upon silver-grain distribution is used to assign labeled cells to 3 H only or with 14 C classes. Optical sectioning combined with grain counting is employed to obtain ratios for classifying cells labeled with 14 C into 14 C only and 3 H + 14 C classes. The method has been tested with CHO-K1 cells in plateau-phase cultures using two 24-h labeling periods. The experimental design allowed for independent estimation of the expected frequencies of label classes under conditions that provided a wide range of possible label levels and combinations. Previous methods have used time-consuming applications of two emulsion layers and exposures to distinguish between cells labeled with 3 H only or with 14 C and do not identify the 3 H + 14 C class. A single-gelatin expanded film requires only one exposure and permits all label classes to be determined by an objective grain-counting procedure

Selecting Cells for Bioartificial Liver Devices and the Importance of a 3D Culture Environment: A Functional Comparison between the HepaRG and C3A Cell Lines

NARCIS (Netherlands)

van Wenum, Martien; Adam, Aziza A. A.; Hakvoort, Theodorus B. M.; Hendriks, Erik J.; Shevchenko, Valery; van Gulik, Thomas M.; Chamuleau, Robert A. F. M.; Hoekstra, Ruurdtje

2016-01-01

Recently, the first clinical trials on Bioartificial Livers (BALs) loaded with a proliferative human hepatocyte cell source have started. There are two cell lines that are currently in an advanced state of BAL development; HepaRG and HepG2/C3A. In this study we aimed to compare both cell lines on

Autophagosome Proteins LC3A, LC3B and LC3C Have Distinct Subcellular Distribution Kinetics and Expression in Cancer Cell Lines.

Directory of Open Access Journals (Sweden)

Michael I Koukourakis

Full Text Available LC3s (MAP1-LC3A, B and C are structural proteins of autophagosomal membranes, widely used as biomarkers of autophagy. Whether these three LC3 proteins have a similar biological role in autophagy remains obscure. We examine in parallel the subcellular expression patterns of the three LC3 proteins in a panel of human cancer cell lines, as well as in normal MRC5 fibroblasts and HUVEC, using confocal microscopy and western blot analysis of cell fractions. In the cytoplasm, there was a minimal co-localization between LC3A, B and C staining, suggesting that the relevant autophagosomes are formed by only one out of the three LC3 proteins. LC3A showed a perinuclear and nuclear localization, while LC3B was equally distributed throughout the cytoplasm and localized in the nucleolar regions. LC3C was located in the cytoplasm and strongly in the nuclei (excluding nucleoli, where it extensively co-localized with the LC3A and the Beclin-1 autophagy initiating protein. Beclin 1 is known to contain a nuclear trafficking signal. Blocking nuclear export function by Leptomycin B resulted in nuclear accumulation of all LC3 and Beclin-1 proteins, while Ivermectin that blocks nuclear import showed reduction of accumulation, but not in all cell lines. Since endogenous LC3 proteins are used as major markers of autophagy in clinical studies and cell lines, it is essential to check the specificity of the antibodies used, as the kinetics of these molecules are not identical and may have distinct biological roles. The distinct subcellular expression patterns of LC3s provide a basis for further studies.

Roles for NHERF1 and NHERF2 on the regulation of C3a receptor signaling in human mast cells.

Directory of Open Access Journals (Sweden)

Hariharan Subramanian

Full Text Available BACKGROUND: The anaphylatoxin C3a binds to the G protein coupled receptor (GPCR, C3aR and activates divergent signaling pathways to induce degranulation and cytokine production in human mast cells. Adapter proteins such as the Na(+/H(+ exchange regulatory factor (NHERF1 and NHERF2 have been implicated in regulating functions of certain GPCRs by binding to the class I PDZ (PSD-95/Dlg/Zo1 motifs present on their cytoplasmic tails. Although C3aR possesses a class I PDZ motif, the possibility that it interacts with NHERF proteins to modulate signaling in human mast cells has not been determined. METHODOLOGY/PRINCIPAL FINDINGS: Using reverse transcription PCR and Western blotting, we found that NHERF1 and NHERF2 are expressed in human mast cell lines (HMC-1, LAD2 and CD34(+-derived primary human mast cells. Surprisingly, however, C3aR did not associate with these adapter proteins. To assess the roles of NHERFs on signaling downstream of C3aR, we used lentiviral shRNA to stably knockdown the expression of these proteins in human mast cells. Silencing the expression of NHERF1 and NHERF2 had no effect on C3aR desensitization, agonist-induced receptor internalization, ERK/Akt phosphorylation or chemotaxis. However, loss of NHERF1 and NHERF2 resulted in significant inhibition of C3a-induced mast cell degranulation, NF-κB activation and chemokine production. CONCLUSION/SIGNIFICANCE: This study demonstrates that although C3aR possesses a class I PDZ motif, it does not associate with NHERF1 and NHERF2. Surprisingly, these proteins provide stimulatory signals for C3a-induced degranulation, NF-κB activation and chemokine generation in human mast cells. These findings reveal a new level of complexity for the functional regulation of C3aR by NHERFs in human mast cells.

Risk-adapted treatment for childhood hepatoblastoma. final report of the second study of the International Society of Paediatric Oncology--SIOPEL 2

NARCIS (Netherlands)

Perilongo, G.; Shafford, E.; Maibach, R.; Aronson, D.; Brugières, L.; Brock, P.; Childs, M.; Czauderna, P.; MacKinlay, G.; Otte, J. B.; Pritchard, J.; Rondelli, R.; Scopinaro, M.; Staalman, C.; Plaschkes, J.

2004-01-01

SIOPEL 2 was a pilot study designed to test the efficacy and toxicity of two chemotherapy (CT) regimens, one for patients with hepatoblastoma (HB) confined to the liver and involving no more than three hepatic sectors ('standard-risk (SR) HB'), and one for those with HB extending into all four

Double labeling autoradiography. Cell kinetic studies with 3H- and 14C-thymidine

International Nuclear Information System (INIS)

Schultze, B.

1981-01-01

Examples of the multiple applicability of the double labeling method with 3 H- and 14 C-TdR are demonstrated. Double labeling with 3 H- and 14 C-TdR makes it possible to determine the cycle and its phases with high precision by modifying the usual percent labeled mitoses method with a single injection of 3 H-TdR. In addition, data is provided on the variances of the transit times through the cycle phases. For example, in the case of the jejunal crypt cells of the mouse, the transit times through successive cycle phases are uncorrelated. In the case of glial cells the double labeling method provides cell kinetic parameters despite the paucity of proliferating glial cells. In the adult untreated animal, glial cell mitoses are so rare that the percent labeled mitoses method can not be utilized. However, the S-phase duration can be measured by double labeling and the cycle time can be determined by the so-called method of labeled S phases. With the latter method the passage through the S phase of the 3 H-TdR-labeled S phase cells can be registered by injecting 14 C-TdR at different time intervals following 3 H-TdR application. In this way an S-phase duration of about 10 hr and a cycle time of about 20 hr was found for glial cells in the adult untreated mouse. An exchange of glial cells between the growth fraction and the nongrowth fraction has also been shown by double labeling. A quite different application of the double labeling method with 3H- and 14 C-TdR is the in vivo study of the cell cycle phase-specific effect of drugs used in chemotherapy of tumors. The effect of vincristine on these cells has been studied. Vincristine affects cells in S and G2 in such a manner that they are arrested during the next metaphase and subsequently become necrotic. It has no effect on G1 cells

Unraveling current hysteresis effects in regular-type C60-CH3NH3PbI3 heterojunction solar cells.

Science.gov (United States)

Chen, Lung-Chien; Lin, Yu-Shiang; Tang, Po-Wen; Tai, Chao-Yi; Tseng, Zong-Liang; Lin, Ja-Hon; Chen, Sheng-Hui; Kuo, Hao-Chung

2017-11-23

Comprehensive studies were carried out to understand the origin of the current hysteresis effects in highly efficient C 60 -CH 3 NH 3 PbI 3 (MAPbI 3 ) heterojunction solar cells, using atomic-force microscopy, transmittance spectra, photoluminescence spectra, X-ray diffraction patterns and a femtosecond time-resolved pump-probe technique. The power conversion efficiency (PCE) of C 60 -MAPbI 3 solar cells can be increased to 18.23% by eliminating the point (lattice) defects in the MAPbI 3 thin film which is fabricated by using the one-step spin-coating method with toluene washing treatment. The experimental results show that the point defects and surface defects of the MAPbI 3 thin films can be minimized by varying the dropping time of the washing solvent. The point defects (surface defects) can be reduced with an (a) increase (decrease) in the dropping time, resulting in an optimized dropping time for obtaining the defect-minimized MAPbI 3 thin film deposited on top of the C 60 thin film. Consequently, the formation of the defect-minimized MAPbI 3 thin film allows for high-efficiency MAPbI 3 solar cells.

Anthracycline resistance mediated by reductive metabolism in cancer cells: The role of aldo-keto reductase 1C3

International Nuclear Information System (INIS)

Hofman, Jakub; Malcekova, Beata; Skarka, Adam; Novotna, Eva; Wsol, Vladimir

2014-01-01

Pharmacokinetic drug resistance is a serious obstacle that emerges during cancer chemotherapy. In this study, we investigated the possible role of aldo-keto reductase 1C3 (AKR1C3) in the resistance of cancer cells to anthracyclines. First, the reducing activity of AKR1C3 toward anthracyclines was tested using incubations with a purified recombinant enzyme. Furthermore, the intracellular reduction of daunorubicin and idarubicin was examined by employing the transfection of A549, HeLa, MCF7 and HCT 116 cancer cells with an AKR1C3 encoding vector. To investigate the participation of AKR1C3 in anthracycline resistance, we conducted MTT cytotoxicity assays with these cells, and observed that AKR1C3 significantly contributes to the resistance of cancer cells to daunorubicin and idarubicin, whereas this resistance was reversible by the simultaneous administration of 2′-hydroxyflavanone, a specific AKR1C3 inhibitor. In the final part of our work, we tracked the changes in AKR1C3 expression after anthracycline exposure. Interestingly, a reciprocal correlation between the extent of induction and endogenous levels of AKR1C3 was recorded in particular cell lines. Therefore, we suggest that the induction of AKR1C3 following exposure to daunorubicin and idarubicin, which seems to be dependent on endogenous AKR1C3 expression, eventually might potentiate an intrinsic resistance given by the normal expression of AKR1C3. In conclusion, our data suggest a substantial impact of AKR1C3 on the metabolism of daunorubicin and idarubicin, which affects their pharmacokinetic and pharmacodynamic behavior. In addition, we demonstrate that the reduction of daunorubicin and idarubicin, which is catalyzed by AKR1C3, contributes to the resistance of cancer cells to anthracycline treatment. - Highlights: • Metabolism of anthracyclines by AKR1C3 was studied at enzyme and cellular levels. • Anthracycline resistance mediated by AKR1C3 was demonstrated in cancer cells. • Induction of AKR1C3

Cellular basis of the immunohematologic defects observed in short-term semiallogeneic B6C3F1→C3H chimeras: evidence for host-versus-graft reaction initiated by radioresistant T cells

International Nuclear Information System (INIS)

Aizawa, S.; Sado, T.; Kamisaku, H.; Kubo, E.

1980-01-01

Lethally irradiated C3Hf mice reconstituted with a relatively low dose (2 x 10 6 ) of B6C3F 1 bone marrow cells (B6C3F 1 →C3Hf chimeras) frequently manifest immunohematologic deficiencies during the first month following injection of bone marrow cells. They show slow recovery of antibody-forming potential to sheep red blood cells (SRBC) as compared to that observed in syngeneic (C3Hf→C3Hf or B6C3F 1 →B6C3F 1 ) chimeras. They also show a deficiency of B-cell activity as assessed by antibody response to SRBC following further reconstitution with B6C3F 1 -derived thymus cells 1 week after injection of bone marrow cells. A significant fraction of B6C3F 1 →C3Hf chimeras was shown to manifest a sudden loss of cellularity of spleens during the second week following injection of bone marrow cells even though cellularity was restored to the normal level within 1 week. The splenic mononuclear cells recovered from such chimeras almost invariably showed strong cytotoxicity against target cells expressing donor-type specific H-2 antigens (H-2/sup b/) when assesed by 51 Cr-release assay in vitro. The effector cells responsible for the observed anti-donor specific cytotoxicity were shown to be residual host-derived T cells. These results indicate strongly that residual host T cells could develop anti-donor specific cytotoxicity even after exposure to a supralethal dose (1050 R) of radiation and that the immunohematologic disturbances observed in shortterm F 1 to parent bone marrow chimeras (B6C3F 1 →C3Hf) were due to host-versus-graft reaction (HVGR) initiated by residual host T cells. The implication of these findings on the radiobiological nature of the residual T cells and the persistence of potentially anti-donor reactive T-cell clones in long-surviving allogeneic bone marrow chimeras was discussed

Protective role of complement C3 against cytokine-mediated beta cell apoptosis

DEFF Research Database (Denmark)

Dos Santos, R. S.; Marroqui, L.; Grieco, F. A.

2017-01-01

Background and aims: Type 1 diabetes is a chronic autoimmune disease characterized by pancreatic islet inflammation and β-cell destruction by pro-inflammatory cytokines and other mediators. The complement system, a major component of the immune system, has been recently shown to also act in metab...... in metabolic organs, such as liver, adipose tissue, and pancreas. In the present study we identified complement C3 as an important hub of a cytokine-modified complement network in human islets and characterized the role of C3 in β-cell survival....

Differential effects of miR-34c-3p and miR-34c-5p on SiHa cells proliferation apoptosis, migration and invasion

Energy Technology Data Exchange (ETDEWEB)

Lopez, Jesus Adrian [Laboratorio de Terapia Genica, Departamento de Genetica y Biologia Molecular, CINVESTAV, Av. IPN 2508, Mexico 07360 D.F. (Mexico); Alvarez-Salas, Luis Marat, E-mail: lalvarez@cinvestav.mx [Laboratorio de Terapia Genica, Departamento de Genetica y Biologia Molecular, CINVESTAV, Av. IPN 2508, Mexico 07360 D.F. (Mexico)

2011-06-10

Highlights: {yields} In this study we examine miR-34c-3p and miR-34c-5p functions in SiHa cells. {yields} We study miRNA effect on cell proliferation, anchorage independent growth, apoptosis, cell motility and invasion. {yields} We find that miR-34c-3p and miR-34c-5p inhibition of proliferation and anchorage independent growth are exclusive to SiHa cells. {yields} miR-34c-3p induces apoptosis and inhibits cell motility and invasion in SiHa cells. {yields} In this study we conclude that miR-34c-3p functions as a tumor suppressor differ from miR-34c-5p. -- Abstract: MicroRNAs (miRNA) regulate expression of several genes associated with human cancer. Here, we analyzed the function of miR-34c, an effector of p53, in cervical carcinoma cells. Expression of either miR-34c-3p or miR-34c-5p mimics caused inhibition of cell proliferation in the HPV-containing SiHa cells but not in other cervical cells irrespective of tumorigenicity and HPV content. These results suggest that SiHa cells may lack of regulatory mechanisms for miR-34c. Monolayer proliferation results showed that miR-34c-3p produced a more pronounced inhibitory effect although both miRNAs caused inhibition of anchorage independent growth at similar extent. However, ectopic expression of pre-miR-34c-3p, but not pre-miR-34c-5p, caused S-phase arrest in SiHa cells triggering a strong dose-dependent apoptosis. A significant inhibition was observed only for miR-34c-3p on SiHa cells migration and invasion, therefore implying alternative regulatory pathways and targets. These results suggest differential tumor suppressor roles for miR-34c-3p and miR-34c-5p and provide new insights in the understanding of miRNA biology.

Differential effects of miR-34c-3p and miR-34c-5p on SiHa cells proliferation apoptosis, migration and invasion

International Nuclear Information System (INIS)

Lopez, Jesus Adrian; Alvarez-Salas, Luis Marat

2011-01-01

Highlights: → In this study we examine miR-34c-3p and miR-34c-5p functions in SiHa cells. → We study miRNA effect on cell proliferation, anchorage independent growth, apoptosis, cell motility and invasion. → We find that miR-34c-3p and miR-34c-5p inhibition of proliferation and anchorage independent growth are exclusive to SiHa cells. → miR-34c-3p induces apoptosis and inhibits cell motility and invasion in SiHa cells. → In this study we conclude that miR-34c-3p functions as a tumor suppressor differ from miR-34c-5p. -- Abstract: MicroRNAs (miRNA) regulate expression of several genes associated with human cancer. Here, we analyzed the function of miR-34c, an effector of p53, in cervical carcinoma cells. Expression of either miR-34c-3p or miR-34c-5p mimics caused inhibition of cell proliferation in the HPV-containing SiHa cells but not in other cervical cells irrespective of tumorigenicity and HPV content. These results suggest that SiHa cells may lack of regulatory mechanisms for miR-34c. Monolayer proliferation results showed that miR-34c-3p produced a more pronounced inhibitory effect although both miRNAs caused inhibition of anchorage independent growth at similar extent. However, ectopic expression of pre-miR-34c-3p, but not pre-miR-34c-5p, caused S-phase arrest in SiHa cells triggering a strong dose-dependent apoptosis. A significant inhibition was observed only for miR-34c-3p on SiHa cells migration and invasion, therefore implying alternative regulatory pathways and targets. These results suggest differential tumor suppressor roles for miR-34c-3p and miR-34c-5p and provide new insights in the understanding of miRNA biology.

Robust hepatitis C genotype 3a cell culture releasing adapted intergenotypic 3a/2a (S52/JFH1) viruses

DEFF Research Database (Denmark)

Gottwein, J.M.; Scheel, Troels Kasper Høyer; Hoegh, A.M.

2007-01-01

BACKGROUND & AIMS: Recently, full viral life cycle hepatitis C virus (HCV) cell culture systems were developed for strain JFH1 (genotype 2a) and an intragenotypic 2a/2a genome (J6/JFH). We aimed at exploiting the unique JFH1 replication characteristics to develop culture systems for genotype 3a......, which has a high prevalence worldwide. METHODS: Huh7.5 cells were transfected with RNA transcripts of an intergenotypic 3a/JFH1 recombinant with core, E1, E2, p7, and NS2 of the 3a reference strain S52, and released viruses were passaged. Cultures were examined for HCV core and/or NS5A expression...... (immunostaining), HCV RNA titers (real-time PCR), and infectivity titers (50% tissue culture infectious dose). The role of mutations identified by sequencing of recovered S52/JFH1 viruses was analyzed by reverse genetics studies. RESULTS: S52/JFH1 and J6/JFH viruses passaged in Huh7.5 cells showed comparable...

Ionic responses rapidly elicited by activation of protein kinase C in quiescent Swiss 3T3 cells

International Nuclear Information System (INIS)

Vara, F.; Schneider, J.A.; Rozengurt, E.

1985-01-01

Diacylglycerol and phorbol esters activate protein kinase C in intact cells. The authors report here that addition of the synthetic diacylglycerol 1-oleoyl-2-acetylglycerol (OAG) to quiescent cultures of Swiss 3T3 cells caused a marked increase in the rate of ouabain-sensitive 86 Rb + uptake, a measure of the activity of the Na + /K + pump. The effect was dose-dependent and could be detected after 1 min of exposure to the diacylglycerol. OAG stimulated Na + influx via an amiloride-sensitive pathway and increased intracellular pH by 0.15 pH unit. Phorbol 12,13-dibutyrate (PBt 2 ) also enhanced ouabain sensitive 86 Rb + uptake and amiloride-sensitive 22 Na + influx. Prolonged treatment (40 hr) of 3T3 cells with PBt 2 at a saturating dose, which reduces the number of PBt 2 binding sites and protein kinase C activity, abolished the ionic response of the cells to a subsequent addition of either OAG or PBt 2 . They suggest that activation of protein kinase C elicits, either directly or indirectly, enhanced Na + /H + antiport activity, which, in turn, leads to Na + influx, intracellular pH modulation, and stimulation of the Na + /K + pump

c-myb stimulates cell growth by regulation of insulin-like growth factor (IGF) and IGF-binding protein-3 in K562 leukemia cells

Energy Technology Data Exchange (ETDEWEB)

Kim, Min-Sun; Kim, Sun-Young; Arunachalam, Sankarganesh [Department of Pediatrics, School of Medicine, Chonbuk National University, Jeonju 561-712 (Korea, Republic of); Hwang, Pyoung-Han [Department of Pediatrics, School of Medicine, Chonbuk National University, Jeonju 561-712 (Korea, Republic of); Research Institute of Clinical Medicine, School of Medicine, Chonbuk National University, Jeonju 561-712 (Korea, Republic of); Yi, Ho-Keun [Department of Biochemistry, School of Dentistry, Chonbuk National University, Jeonju 561-712 (Korea, Republic of); Nam, Sang-Yun [Department of Alternative Therapy, School of Alternative Medicine and Health Science, Jeonju University, Jeonju 561-712 (Korea, Republic of); Lee, Dae-Yeol, E-mail: leedy@chonbuk.ac.kr [Department of Pediatrics, School of Medicine, Chonbuk National University, Jeonju 561-712 (Korea, Republic of); Research Institute of Clinical Medicine, School of Medicine, Chonbuk National University, Jeonju 561-712 (Korea, Republic of)

2009-07-17

c-myb plays an important role in the regulation of cell growth and differentiation, and is highly expressed in immature hematopoietic cells. The human chronic myelogenous leukemia cell K562, highly expresses IGF-I, IGF-II, IGF-IR, and IGF-induced cellular proliferation is mediated by IGF-IR. To characterize the impact of c-myb on the IGF-IGFBP-3 axis in leukemia cells, we overexpressed c-myb using an adenovirus gene transfer system in K562 cells. The overexpression of c-myb induced cell proliferation, compared to control, and c-myb induced cell growth was inhibited by anti-IGF-IR antibodies. c-myb overexpression resulted in a significant increase in the expression of IGF-I, IGF-II, and IGF-IR, and a decrease in IGFBP-3 expression. By contrast, disruption of c-myb function by DN-myb overexpression resulted in significant reduction of IGF-I, IGF-II, IGF-IR, and elevation of IGFBP-3 expression. In addition, exogenous IGFBP-3 inhibited the proliferation of K562 cells, and c-myb induced cell growth was blocked by IGFBP-3 overexpression in a dose-dependent manner. The growth-promoting effects of c-myb were mediated through two major intracellular signaling pathways, Akt and Erk. Activation of Akt and Erk by c-myb was completely blocked by IGF-IR and IGFBP-3 antibodies. These findings suggest that c-myb stimulates cell growth, in part, by regulating expression of the components of IGF-IGFBP axis in K562 cells. In addition, disruption of c-myb function by DN-myb may provide a useful strategy for treatment of leukemia.

c-myb stimulates cell growth by regulation of insulin-like growth factor (IGF) and IGF-binding protein-3 in K562 leukemia cells

International Nuclear Information System (INIS)

Kim, Min-Sun; Kim, Sun-Young; Arunachalam, Sankarganesh; Hwang, Pyoung-Han; Yi, Ho-Keun; Nam, Sang-Yun; Lee, Dae-Yeol

2009-01-01

c-myb plays an important role in the regulation of cell growth and differentiation, and is highly expressed in immature hematopoietic cells. The human chronic myelogenous leukemia cell K562, highly expresses IGF-I, IGF-II, IGF-IR, and IGF-induced cellular proliferation is mediated by IGF-IR. To characterize the impact of c-myb on the IGF-IGFBP-3 axis in leukemia cells, we overexpressed c-myb using an adenovirus gene transfer system in K562 cells. The overexpression of c-myb induced cell proliferation, compared to control, and c-myb induced cell growth was inhibited by anti-IGF-IR antibodies. c-myb overexpression resulted in a significant increase in the expression of IGF-I, IGF-II, and IGF-IR, and a decrease in IGFBP-3 expression. By contrast, disruption of c-myb function by DN-myb overexpression resulted in significant reduction of IGF-I, IGF-II, IGF-IR, and elevation of IGFBP-3 expression. In addition, exogenous IGFBP-3 inhibited the proliferation of K562 cells, and c-myb induced cell growth was blocked by IGFBP-3 overexpression in a dose-dependent manner. The growth-promoting effects of c-myb were mediated through two major intracellular signaling pathways, Akt and Erk. Activation of Akt and Erk by c-myb was completely blocked by IGF-IR and IGFBP-3 antibodies. These findings suggest that c-myb stimulates cell growth, in part, by regulating expression of the components of IGF-IGFBP axis in K562 cells. In addition, disruption of c-myb function by DN-myb may provide a useful strategy for treatment of leukemia.

Increased radiation-induced transformation in C3H/10T1/2 cells after transfer of an exogenous c-myc gene

International Nuclear Information System (INIS)

Sorrentino, V.; Drozdoff, V.; Zeitz, L.; Fleissner, E.

1987-01-01

C3H/10T 1/2 cells were infected with a retroviral vector expressing a mouse c-myc oncogene and a drug-selection marker. The resulting cells, morphologically indistinguishable from C3H/10T l/1, displayed a greatly enhanced sensitivity to neoplastic transformation by ionizing radiation or by a chemical carcinogen. Constitutive expression of myc therefore appears to synergize with an initial carcinogenic event, providing a function analogous to a subsequent event that apparently is required for the neoplastic transformation of these cells. This cell system should prove useful in exploring early stages in radiation-induced transformation

Morphometric studies with attached mouse C3H/10T 1/2 cells

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Geard, C.R.; Harding, T.

1981-01-01

Studies of in vitro transformation using the Syrian hamster embryo cell system and the mouse C3H/10T 1/2 cell system form an integral part of this laboratory's activities. As part of the studies with the mouse cell line we have monitored the behavior of these cells in culture in order to ascertain those variables which might influence the expression of transformation. The study of transformed cells versus normal cells could lead to insight into an earlier definition of transformation that the clonal morphological change currently in use. This present report details the changes in cellular morphology with time in culture of normal mouse C3H/10T 1/2 cells from early passages (9 to 13) and x-ray transformed cells which have been maintained in culture for three years

Rad51C deficiency destabilizes XRCC3, impairs recombination and radiosensitizes S/G2-phase cells

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Lio, Yi-Ching; Schild, David; Brenneman, Mark A.; Redpath, J. Leslie; Chen, David J.

2004-05-01

The highly conserved Rad51 protein plays an essential role in repairing DNA damage through homologous recombination. In vertebrates, five Rad51 paralogs (Rad51B, Rad51C, Rad51D, XRCC2, XRCC3) are expressed in mitotically growing cells, and are thought to play mediating roles in homologous recombination, though their precise functions remain unclear. Here we report the use of RNA interference to deplete expression of Rad51C protein in human HT1080 and HeLa cells. In HT1080 cells, depletion of Rad51C by small interfering RNA caused a significant reduction of frequency in homologous recombination. The level of XRCC3 protein was also sharply reduced in Rad51C-depleted HeLa cells, suggesting that XRCC3 is dependent for its stability upon heterodimerization with Rad51C. In addition, Rad51C-depleted HeLa cells showed hypersensitivity to the DNA cross-linking agent mitomycin C, and moderately increased sensitivity to ionizing radiation. Importantly, the radiosensitivity of Rad51C-deficient HeLa cells was evident in S and G{sub 2}/M phases of the cell cycle but not in G{sub 1} phase. Together, these results provide direct cellular evidence for the importance of human Rad51C in homologous recombinational repair.

Activated Integrin-Linked Kinase Negatively Regulates Muscle Cell Enhancement Factor 2C in C2C12 Cells

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Zhenguo Dong

2015-01-01

Full Text Available Our previous study reported that muscle cell enhancement factor 2C (MEF2C was fully activated after inhibition of the phosphorylation activity of integrin-linked kinase (ILK in the skeletal muscle cells of goats. It enhanced the binding of promoter or enhancer of transcription factor related to proliferation of muscle cells and then regulated the expression of these genes. In the present investigation, we explored whether ILK activation depended on PI3K to regulate the phosphorylation and transcriptional activity of MEF2C during C2C12 cell proliferation. We inhibited PI3K activity in C2C12 with LY294002 and then found that ILK phosphorylation levels and MEF2C phosphorylation were decreased and that MCK mRNA expression was suppressed significantly. After inhibiting ILK phosphorylation activity with Cpd22 and ILK-shRNA, we found MEF2C phosphorylation activity and MCK mRNA expression were increased extremely significantly. In the presence of Cpd22, PI3K activity inhibition increased MEF2C phosphorylation and MCK mRNA expression indistinctively. We conclude that ILK negatively and independently of PI3K regulated MEF2C phosphorylation activity and MCK mRNA expression in C2C12 cells. The results provide new ideas for the study of classical signaling pathway of PI3K-ILK-related proteins and transcription factors.

Cytotoxic effects of the synthetic oestrogens and androgens on Balb/c 3T3 and HepG2 cells

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Minta Maria

2014-12-01

Full Text Available The aim of the study was to test and compare the cytotoxic potential of two synthetic oestrogens: diethylstilboestrol (DES and ethinyloestradiol (EE2 and two androgens: testosterone propionate (TP and trenbolone (TREN on two cell lines. The fibroblast cell line Balb/c 3T3 and the hepatoma cell line HepG2 were selected. To get more insight into the mode of toxic action, four methods were used, which evaluated different biochemical endpoints: mitochondrial activity (3-(4,5-dimethylthiazol-2-yl- 2,5-diphenyltetrazolium bromide reduction assay, lysosomal activity (neutral red uptake assay, total protein content, and lactate dehydrogenase release. Cytotoxicity was assessed after 24, 48, and 72 h exposure to eight concentrations ranging from 0.78 to 100 μg/mL. Concentration- and time- dependent effects were observed. Depending on the line and assay used, half maximal effective concentration after 72 h (EC50-72h values ranged as follows: DES 1-13.7 μg/mL (Balb/c 3T3 and 3.7-5.2 μg/mL (HepG2; EE2 2.1-14.3 μg/mL (Balb/c 3T3 and 1.8-7.8 μg/mL (HepG2; TP-14.9-17.5 μg/mL (Balb/c 3T3, and 63.9- 100 μg/mL (HepG2; and TREN 11.3-31.4 μg/mL (Balb/c 3T3 and 12.5-59.4 μg/mL (HepG2. The results revealed that oestrogens were more toxic than androgens and the most affected endpoint was mitochondrial activity. In contrast to oestrogens, for which EC50-72h values were similar in both lines and by all assays used, Balb/c 3T3 cells were more sensitive than HepG2 cells to TP.

Andrographolide inhibits adipogenesis of 3T3-L1 cells by suppressing C/EBPβ expression and activation

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Chen, Ching-Chu; Chuang, Wei-Ting; Lin, Ai-Hsuan; Tsai, Chia-Wen; Huang, Chin-Shiu; Chen, Yun-Ting; Chen, Haw-Wen; Lii, Chong-Kuei

2016-01-01

Andrographolide, a diterpenoid, is the most abundant terpenoid in Andrographis paniculata, a popular Chinese herbal medicine. Andrographolide displays diverse biological activities including hypoglycemia, hypolipidemia, anti-inflammation, and anti-tumorigenesis. Recent evidence indicates that andrographolide displays anti-obesity property by inhibiting lipogenic gene expression, however, the underlying mechanisms remain to be elucidated. In this study, the effects of andrographolide on transcription factor cascade and mitotic clonal expansion in 3T3-L1 preadipocyte differentiation into adipocyte were determined. Andrographolide dose-dependently (0–15 μM) inhibited CCAAT/enhancer-binding protein α (C/EBPα) and C/EBPβ mRNA and protein expression as well as peroxisome proliferator-activated receptor γ (PPARγ) protein level during the adipogenesis of 3T3-L1 cells. Concomitantly, fatty acid synthase and stearoyl-CoA desaturase expression and lipid accumulation were attenuated by andrographolide. Oil-red O staining further showed that the first 48 h after the initiation of differentiation was critical for andrographolide inhibition of adipocyte formation. Andrographolide inhibited the phosphorylation of PKA and the activation of cAMP response element-binding protein (CREB) in response to a differentiation cocktail, which led to attenuated C/EBPβ expression. In addition, ERK and GSK3β-dependent C/EBPβ phosphorylation was attenuated by andrographolide. Moreover, andrographolide suppressed cyclin A, cyclin E, and CDK2 expression and impaired the progression of mitotic clonal expansion (MCE) by arresting the cell cycle at the Go/G1 phase. Taken together, these results indicate that andrographolide has a potent anti-obesity action by inhibiting PKA-CREB-mediated C/EBPβ expression as well as C/EBPβ transcriptional activity, which halts MCE progression and attenuates C/EBPα and PPARγ expression. - Highlights: • Andrographolide is a diterpenoid phytochemical. �

Andrographolide inhibits adipogenesis of 3T3-L1 cells by suppressing C/EBPβ expression and activation

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Chen, Ching-Chu [Division of Endocrinology and Metabolism, Department of Medicine, China Medical University Hospital, Taichung, Taiwan (China); Division of Endocrinology and Metabolism, Department of Chinese Medicine, China Medical University, China Medical University, Taichung, Taiwan (China); Chuang, Wei-Ting; Lin, Ai-Hsuan; Tsai, Chia-Wen [Department of Nutrition, China Medical University, Taichung, Taiwan (China); Huang, Chin-Shiu [Department of Health and Nutrition Biotechnology, Asia University, Taichung, Taiwan (China); Department of Medical Research, China Medical University Hospital, Taichung, Taiwan (China); Chen, Yun-Ting [Department of Nutrition, China Medical University, Taichung, Taiwan (China); Chen, Haw-Wen, E-mail: chenhw@mail.cmu.edu.tw [Department of Nutrition, China Medical University, Taichung, Taiwan (China); Lii, Chong-Kuei, E-mail: cklii@mail.cmu.edu.tw [Department of Nutrition, China Medical University, Taichung, Taiwan (China); Department of Health and Nutrition Biotechnology, Asia University, Taichung, Taiwan (China)

2016-09-15

Andrographolide, a diterpenoid, is the most abundant terpenoid in Andrographis paniculata, a popular Chinese herbal medicine. Andrographolide displays diverse biological activities including hypoglycemia, hypolipidemia, anti-inflammation, and anti-tumorigenesis. Recent evidence indicates that andrographolide displays anti-obesity property by inhibiting lipogenic gene expression, however, the underlying mechanisms remain to be elucidated. In this study, the effects of andrographolide on transcription factor cascade and mitotic clonal expansion in 3T3-L1 preadipocyte differentiation into adipocyte were determined. Andrographolide dose-dependently (0–15 μM) inhibited CCAAT/enhancer-binding protein α (C/EBPα) and C/EBPβ mRNA and protein expression as well as peroxisome proliferator-activated receptor γ (PPARγ) protein level during the adipogenesis of 3T3-L1 cells. Concomitantly, fatty acid synthase and stearoyl-CoA desaturase expression and lipid accumulation were attenuated by andrographolide. Oil-red O staining further showed that the first 48 h after the initiation of differentiation was critical for andrographolide inhibition of adipocyte formation. Andrographolide inhibited the phosphorylation of PKA and the activation of cAMP response element-binding protein (CREB) in response to a differentiation cocktail, which led to attenuated C/EBPβ expression. In addition, ERK and GSK3β-dependent C/EBPβ phosphorylation was attenuated by andrographolide. Moreover, andrographolide suppressed cyclin A, cyclin E, and CDK2 expression and impaired the progression of mitotic clonal expansion (MCE) by arresting the cell cycle at the Go/G1 phase. Taken together, these results indicate that andrographolide has a potent anti-obesity action by inhibiting PKA-CREB-mediated C/EBPβ expression as well as C/EBPβ transcriptional activity, which halts MCE progression and attenuates C/EBPα and PPARγ expression. - Highlights: • Andrographolide is a diterpenoid phytochemical. �

Immune cell-derived c3 is required for autoimmune diabetes induced by multiple low doses of streptozotocin.

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Lin, Marvin; Yin, Na; Murphy, Barbara; Medof, M Edward; Segerer, Stephan; Heeger, Peter S; Schröppel, Bernd

2010-09-01

The complement system contributes to autoimmune injury, but its involvement in promoting the development of autoimmune diabetes is unknown. In this study, our goal was to ascertain the role of complement C3 in autoimmune diabetes. Susceptibility to diabetes development after multiple low-dose streptozotocin treatment in wild-type (WT) and C3-deficient mice was analyzed. Bone marrow chimeras, luminex, and quantitative reverse transcription PCR assays were performed to evaluate the phenotypic and immunologic impact of C3 in the development of this diabetes model. Coincident with the induced elevations in blood glucose levels, we documented alternative pathway complement component gene expression within the islets of the diabetic WT mice. When we repeated the experiments with C3-deficient mice, we observed complete resistance to disease, as assessed by the absence of histologic insulitis and the absence of T-cell reactivity to islet antigens. Studies of WT chimeras bearing C3-deficient bone marrow cells showed that bone marrow cell-derived C3, and not serum C3, is involved in the induction of diabetes in this model. The data reveal a key role for immune cell-derived C3 in the pathogenesis of murine multiple low-dose streptozotocin-induced diabetes and support the concept that immune cell mediated diabetes is in part complement-dependent.

Thimerosal-induced apoptosis in mouse C2C12 myoblast cells occurs through suppression of the PI3K/Akt/survivin pathway.

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Wen-Xue Li

Full Text Available BACKGROUND: Thimerosal, a mercury-containing preservative, is one of the most widely used preservatives and found in a variety of biological products. Concerns over its possible toxicity have reemerged recently due to its use in vaccines. Thimerosal has also been reported to be markedly cytotoxic to neural tissue. However, little is known regarding thimerosal-induced toxicity in muscle tissue. Therefore, we investigated the cytotoxic effect of thimerosal and its possible mechanisms on mouse C2C12 myoblast cells. METHODOLOGY/PRINCIPAL FINDINGS: The study showed that C2C12 myoblast cells underwent inhibition of proliferation and apoptosis after exposure to thimerosal (125-500 nM for 24, 48 and 72 h. Thimerosal caused S phase arrest and induced apoptosis as assessed by flow cytometric analysis, Hoechst staining and immunoblotting. The data revealed that thimerosal could trigger the leakage of cytochrome c from mitochondria, followed by cleavage of caspase-9 and caspase-3, and that an inhibitor of caspase could suppress thimerosal-induced apoptosis. Thimerosal inhibited the phosphorylation of Akt(ser473 and survivin expression. Wortmannin, a PI3K inhibitor, inhibited Akt activity and decreased survivin expression, resulting in increased thimerosal-induced apoptosis in C2C12 cells, while the activation of PI3K/Akt pathway by mIGF-I (50 ng/ml increased the expression of survivin and attenuated apoptosis. Furthermore, the inhibition of survivin expression by siRNA enhanced thimerosal-induced cell apoptosis, while overexpression of survivin prevented thimerosal-induced apoptosis. Taken together, the data show that the PI3K/Akt/survivin pathway plays an important role in the thimerosal-induced apoptosis in C2C12 cells. CONCLUSIONS/SIGNIFICANCE: Our results suggest that in C2C12 myoblast cells, thimerosal induces S phase arrest and finally causes apoptosis via inhibition of PI3K/Akt/survivin signaling followed by activation of the mitochondrial apoptotic

Sema3C Promotes the Survival and Tumorigenicity of Glioma Stem Cells through Rac1 Activation

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Jianghong Man

2014-12-01

Full Text Available Summary: Different cancer cell compartments often communicate through soluble factors to facilitate tumor growth. Glioma stem cells (GSCs are a subset of tumor cells that resist standard therapy to contribute to disease progression. How GSCs employ a distinct secretory program to communicate with and nurture each other over the nonstem tumor cell (NSTC population is not well defined. Here, we show that GSCs preferentially secrete Sema3C and coordinately express PlexinA2/D1 receptors to activate Rac1/nuclear factor (NF-κB signaling in an autocrine/paracrine loop to promote their own survival. Importantly, Sema3C is not expressed in neural progenitor cells (NPCs or NSTCs. Disruption of Sema3C induced apoptosis of GSCs, but not NPCs or NSTCs, and suppressed tumor growth in orthotopic models of glioblastoma. Introduction of activated Rac1 rescued the Sema3C knockdown phenotype in vivo. Our study supports the targeting of Sema3C to break this GSC-specific autocrine/paracrine loop in order to improve glioblastoma treatment, potentially with a high therapeutic index. : Glioma stem cells (GSCs have a high capacity for self-renewal, invasion, and survival. How they communicate with each other to survive and maintain their identity is not clear. Man et al. now show that GSCs have co-opted a neurodevelopmental program to activate Rac1 to promote defining features of GSCs.

Foxp3+ Regulatory T Cells Delay Expulsion of Intestinal Nematodes by Suppression of IL-9-Driven Mast Cell Activation in BALB/c but Not in C57BL/6 Mice

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Brenz, Yannick; Eschbach, Marie-Luise; Hartmann, Wiebke; Haben, Irma; Sparwasser, Tim; Huehn, Jochen; Kühl, Anja; Feyerabend, Thorsten B.; Rodewald, Hans-Reimer; Breloer, Minka

2014-01-01

Accumulating evidence suggests that IL-9-mediated immunity plays a fundamental role in control of intestinal nematode infection. Here we report a different impact of Foxp3+ regulatory T cells (Treg) in nematode-induced evasion of IL-9-mediated immunity in BALB/c and C57BL/6 mice. Infection with Strongyloides ratti induced Treg expansion with similar kinetics and phenotype in both strains. Strikingly, Treg depletion reduced parasite burden selectively in BALB/c but not in C57BL/6 mice. Treg function was apparent in both strains as Treg depletion increased nematode-specific humoral and cellular Th2 response in BALB/c and C57BL/6 mice to the same extent. Improved resistance in Treg-depleted BALB/c mice was accompanied by increased production of IL-9 and accelerated degranulation of mast cells. In contrast, IL-9 production was not significantly elevated and kinetics of mast cell degranulation were unaffected by Treg depletion in C57BL/6 mice. By in vivo neutralization, we demonstrate that increased IL-9 production during the first days of infection caused accelerated mast cell degranulation and rapid expulsion of S. ratti adults from the small intestine of Treg-depleted BALB/c mice. In genetically mast cell-deficient (Cpa3-Cre) BALB/c mice, Treg depletion still resulted in increased IL-9 production but resistance to S. ratti infection was lost, suggesting that IL-9-driven mast cell activation mediated accelerated expulsion of S. ratti in Treg-depleted BALB/c mice. This IL-9-driven mast cell degranulation is a central mechanism of S. ratti expulsion in both, BALB/c and C57BL/6 mice, because IL-9 injection reduced and IL-9 neutralization increased parasite burden in the presence of Treg in both strains. Therefore our results suggest that Foxp3+ Treg suppress sufficient IL-9 production for subsequent mast cell degranulation during S. ratti infection in a non-redundant manner in BALB/c mice, whereas additional regulatory pathways are functional in Treg-depleted C57BL/6

No activation of new initiation points for deoxyribonucleic acid replication in BALB/c 3T3 cells transformed by Kirsten sarcoma virus

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Oppenheim, A.; Horowitz, A.T.

1981-01-01

BALB/c 3T3 cells were transformed by Kirsten sarcoma virus, and five clones were isolated in soft agar. Average replicon sizes of the transformed cell lines were stimated by the method of fiber-autoradiography and found to be the same size as the nontransformed 3T3 cells, analyzed in parallel. The results indicate that, unlike simian virus 40 and Epstein-Barr virus, Kirsten sarcoma virus does not activate new initiation points for cellular deoxyribonucleic acid replication in murine sarcome virus-transformed BALB/c 3T3 cells

Andrographolide inhibits adipogenesis of 3T3-L1 cells by suppressing C/EBPβ expression and activation.

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Chen, Ching-Chu; Chuang, Wei-Ting; Lin, Ai-Hsuan; Tsai, Chia-Wen; Huang, Chin-Shiu; Chen, Yun-Ting; Chen, Haw-Wen; Lii, Chong-Kuei

2016-09-15

Andrographolide, a diterpenoid, is the most abundant terpenoid in Andrographis paniculata, a popular Chinese herbal medicine. Andrographolide displays diverse biological activities including hypoglycemia, hypolipidemia, anti-inflammation, and anti-tumorigenesis. Recent evidence indicates that andrographolide displays anti-obesity property by inhibiting lipogenic gene expression, however, the underlying mechanisms remain to be elucidated. In this study, the effects of andrographolide on transcription factor cascade and mitotic clonal expansion in 3T3-L1 preadipocyte differentiation into adipocyte were determined. Andrographolide dose-dependently (0-15μM) inhibited CCAAT/enhancer-binding protein α (C/EBPα) and C/EBPβ mRNA and protein expression as well as peroxisome proliferator-activated receptor γ (PPARγ) protein level during the adipogenesis of 3T3-L1 cells. Concomitantly, fatty acid synthase and stearoyl-CoA desaturase expression and lipid accumulation were attenuated by andrographolide. Oil-red O staining further showed that the first 48h after the initiation of differentiation was critical for andrographolide inhibition of adipocyte formation. Andrographolide inhibited the phosphorylation of PKA and the activation of cAMP response element-binding protein (CREB) in response to a differentiation cocktail, which led to attenuated C/EBPβ expression. In addition, ERK and GSK3β-dependent C/EBPβ phosphorylation was attenuated by andrographolide. Moreover, andrographolide suppressed cyclin A, cyclin E, and CDK2 expression and impaired the progression of mitotic clonal expansion (MCE) by arresting the cell cycle at the Go/G1 phase. Taken together, these results indicate that andrographolide has a potent anti-obesity action by inhibiting PKA-CREB-mediated C/EBPβ expression as well as C/EBPβ transcriptional activity, which halts MCE progression and attenuates C/EBPα and PPARγ expression. Copyright © 2016 Elsevier Inc. All rights reserved.

High-level expression of human insulin receptor cDNA in mouse NIH 3T3 cells

International Nuclear Information System (INIS)

Whittaker, J.; Okamoto, A.K.; Thys, R.; Bell, G.I.; Steiner, D.F.; Hofmann, C.A.

1987-01-01

In order to develop a simple, efficient system for the high-level expression of human insulin receptors in eukaryotic cells, a full-length human kidney insulin receptor cDNA was inserted into a bovine papilloma virus vector under the control of the mouse metallothionein promoter. After transfection of mouse NIH 3T3 cells with this construct, seven cell lines expressing insulin receptors were isolated; two cell lines had more than 10 6 receptors per cell. The cell line with the highest 125 I-insulin binding (NIH 3T3 HIR3.5) had 6 x 10 6 receptors with a K/sub d/ of 10 -9 M. This level was not dependent on exposure to metals but could be increased further to 2 x 10 7 receptors per cell by addition of sodium butyrate to the culture medium. The α and β subunits had apparent molecular weights of 147,000 and 105,000, respectively (compared to 135,000 and 95,000 in IM-9 human lymphocytes), values identical to those of the α and β subunits of the insulin receptors of nontransformed NIH 3T3 cells. This size difference was due to altered carbohydrate composition, as N-glycanase digestion reduced the apparent receptor subunit size of the transfected cells and IM-9 lymphocytes to identical values. The alteration in N-linked oligosaccharide composition could not be ascribed to differences in the kinetics of posttranslational processing of the insulin receptors, which was comparable to that of other cells studied. The basal rate of glycogen synthesis in the cells overexpressing insulin receptors was increased 4- to 5-fold compared with controls. Low levels of added insulin (0.1 nM) caused a 50% increase in the rate of glycogen synthesis

Semaphorin 3 C drives epithelial-to-mesenchymal transition, invasiveness, and stem-like characteristics in prostate cells.

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Tam, Kevin J; Hui, Daniel H F; Lee, Wilson W; Dong, Mingshu; Tombe, Tabitha; Jiao, Ivy Z F; Khosravi, Shahram; Takeuchi, Ario; Peacock, James W; Ivanova, Larissa; Moskalev, Igor; Gleave, Martin E; Buttyan, Ralph; Cox, Michael E; Ong, Christopher J

2017-09-13

Prostate cancer (PCa) is among the most commonly-occurring cancers worldwide and a leader in cancer-related deaths. Local non-invasive PCa is highly treatable but limited treatment options exist for those with locally-advanced and metastatic forms of the disease underscoring the need to identify mechanisms mediating PCa progression. The semaphorins are a large grouping of membrane-associated or secreted signalling proteins whose normal roles reside in embryogenesis and neuronal development. In this context, semaphorins help establish chemotactic gradients and direct cell movement. Various semaphorin family members have been found to be up- and down-regulated in a number of cancers. One family member, Semaphorin 3 C (SEMA3C), has been implicated in prostate, breast, ovarian, gastric, lung, and pancreatic cancer as well as glioblastoma. Given SEMA3C's roles in development and its augmented expression in PCa, we hypothesized that SEMA3C promotes epithelial-to-mesenchymal transition (EMT) and stem-like phenotypes in prostate cells. In the present study we show that ectopic expression of SEMA3C in RWPE-1 promotes the upregulation of EMT and stem markers, heightened sphere-formation, and cell plasticity. In addition, we show that SEMA3C promotes migration and invasion in vitro and cell dissemination in vivo.

Stem/Progenitor Cell Proteoglycans Decorated with 7-D-4, 4-C-3 and 3-B-3(-) Chondroitin Sulphate Motifs Are Morphogenetic Markers Of Tissue Development.

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Hayes, Anthony J; Smith, Susan M; Caterson, Bruce; Melrose, James

2018-06-11

This study reviewed the occurrence of chondroitin sulphate (CS) motifs 4-C-3, 7-D-4 and 3-B-3(-) which are expressed by progenitor cells in tissues undergoing morphogenesis. These motifs have a transient early expression pattern during tissue development and also appear in mature tissues during pathological remodeling and attempted repair processes by activated adult stem cells. The CS motifs are information and recognition modules, which may regulate cellular behavior and delineate stem cell niches in developmental tissues. One of the difficulties in determining the precise role of stem cells in tissue development and repair processes is their short engraftment period and the lack of specific markers, which differentiate the activated stem cell lineages from the resident cells. The CS sulphation motifs 7-D-4, 4-C-3 and 3-B-3 (-) decorate cell surface proteoglycans on activated stem/progenitor cells and appear to identify these cells in transitional areas of tissue development and in tissue repair and may be applicable to determining a more precise role for stem cells in tissue morphogenesis. This article is protected by copyright. All rights reserved. © 2018 AlphaMed Press.

Saposin C promotes survival and prevents apoptosis via PI3K/Akt-dependent pathway in prostate cancer cells

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Lee Tae-Jin

2004-11-01

Full Text Available Abstract Background In addition to androgens, growth factors are also implicated in the development and neoplastic growth of the prostate gland. Prosaposin is a potent neurotrophic molecule. Homozygous inactivation of prosaposin in mice has led to the development of a number of abnormalities in the male reproductive system, including atrophy of the prostate gland and inactivation of mitogen-activated protein kinase (MAPK and Akt in prostate epithelial cells. We have recently reported that prosaposin is expressed at a higher level by androgen-independent (AI prostate cancer cells as compared to androgen-sensitive prostate cancer cells or normal prostate epithelial and stromal cells. In addition, we have demonstrated that a synthetic peptide (prosaptide TX14A, derived from the trophic sequence of the saposin C domain of prosaposin, stimulated cell proliferation, migration and invasion and activated the MAPK signaling pathway in prostate cancer cells. The biological significances of saposin C and prosaposin in prostate cancer are not known. Results Here, we report that saposin C, in a cell type-specific and dose-dependent manner, acts as a survival factor, activates the Akt-signaling pathway, down-modulates caspase-3, -7, and -9 expression and/or activity, and decreases the cleaved nuclear substrate of caspase-3 in prostate cancer cells under serum-starvation stress. In addition, prosaptide TX14A, saposin C, or prosaposin decreased the growth-inhibitory effect, caspase-3/7 activity, and apoptotic cell death induced by etoposide. We also discovered that saposin C activates the p42/44 MAP kinase pathway in a pertussis toxin-sensitive and phosphatidylinositol 3-kinase (PI3K /Akt-dependent manner in prostate cancer cells. Our data also show that the anti-apoptotic activity of saposin C is at least partially mediated via PI3K/Akt signaling pathway. Conclusion We postulate that as a mitogenic, survival, and anti-apoptotic factor for prostate cancer cells

The Complement C3a-C3aR Axis Promotes Development of Thoracic Aortic Dissection via Regulation of MMP2 Expression.

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Ren, Weihong; Liu, Yan; Wang, Xuerui; Piao, Chunmei; Ma, Youcai; Qiu, Shulan; Jia, Lixin; Chen, Boya; Wang, Yuan; Jiang, Wenjian; Zheng, Shuai; Liu, Chang; Dai, Nan; Lan, Feng; Zhang, Hongjia; Song, Wen-Chao; Du, Jie

2018-03-01

Thoracic aortic dissection (TAD), once ruptured, is devastating to patients, and no effective pharmaceutical therapy is available. Anaphylatoxins released by complement activation are involved in a variety of diseases. However, the role of the complement system in TAD is unknown. We found that plasma levels of C3a, C4a, and C5a were significantly increased in patients with TAD. Elevated circulating C3a levels were also detected in the developmental process of mouse TAD, which was induced by β-aminopropionitrile monofumarate (BAPN) treatment, with enhanced expression of C1q and properdin in mouse dissected aortas. These findings indicated activation of classical and alternative complement pathways. Further, expression of C3aR was obviously increased in smooth muscle cells of human and mouse dissected aortas, and knockout of C3aR notably inhibited BAPN-induced formation and rupture of TAD in mice. C3aR antagonist administered pre- and post-BAPN treatment attenuated the development of TAD. We found that C3aR knockout decreased matrix metalloproteinase 2 (MMP2) expression in BAPN-treated mice. Additionally, recombinant C3a stimulation enhanced MMP2 expression and activation in smooth muscle cells that were subjected to mechanical stretch. Finally, we generated MMP2-knockdown mice by in vivo MMP2 short hairpin RNA delivery using recombinant adeno-associated virus and found that MMP2 deficiency significantly reduced the formation of TAD. Therefore, our study suggests that the C3a - C3aR axis contributes to the development of TAD via regulation of MMP2 expression. Targeting the C3a-C3aR axis may represent a strategy for inhibiting the formation of TAD. Copyright © 2018 by The American Association of Immunologists, Inc.

MAPK phosphatase AP2C3 induces ectopic proliferation of epidermal cells leading to stomata development in Arabidopsis.

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Julija Umbrasaite

2010-12-01

Full Text Available In plant post-embryonic epidermis mitogen-activated protein kinase (MAPK signaling promotes differentiation of pavement cells and inhibits initiation of stomata. Stomata are cells specialized to modulate gas exchange and water loss. Arabidopsis MAPKs MPK3 and MPK6 are at the core of the signaling cascade; however, it is not well understood how the activity of these pleiotropic MAPKs is constrained spatially so that pavement cell differentiation is promoted only outside the stomata lineage. Here we identified a PP2C-type phosphatase termed AP2C3 (Arabidopsis protein phosphatase 2C that is expressed distinctively during stomata development as well as interacts and inactivates MPK3, MPK4 and MPK6. AP2C3 co-localizes with MAPKs within the nucleus and this localization depends on its N-terminal extension. We show that other closely related phosphatases AP2C2 and AP2C4 are also MAPK phosphatases acting on MPK6, but have a distinct expression pattern from AP2C3. In accordance with this, only AP2C3 ectopic expression is able to stimulate cell proliferation leading to excess stomata development. This function of AP2C3 relies on the domains required for MAPK docking and intracellular localization. Concomitantly, the constitutive and inducible AP2C3 expression deregulates E2F-RB pathway, promotes the abundance and activity of CDKA, as well as changes of CDKB1;1 forms. We suggest that AP2C3 downregulates the MAPK signaling activity to help maintain the balance between differentiation of stomata and pavement cells.

Oxyfadichalcone C inhibits melanoma A375 cell proliferation and metastasis via suppressing PI3K/Akt and MAPK/ERK pathways.

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Peng, Xiaolin; Wang, Zhengming; Liu, Yang; Peng, Xin; Liu, Yao; Zhu, Shan; Zhang, Zhe; Qiu, Yuling; Jin, Meihua; Wang, Ran; Zhang, Qingying; Kong, Dexin

2018-08-01

Melanoma remains to be one of the most incurable cancers. Discovery of novel antitumor agent for melanoma therapy is expected. We recently isolated Oxyfadichalcone C from Oxytropis falcate and investigated the anti-proliferative and anti-metastatic activity on human melanoma A375 cells in vitro. Cell viability was determined using MTT assay and soft agar cloning formation assay. The effect of Oxyfadichalcone C on cell cycle distribution and apoptosis were analyzed by flow cytometry. Cell metastasis was determined by wound healing assay, Transwell assay and Gelatin zymography assay. The effect of Oxyfadichalcone C on signal proteins of PI3K/Akt and MAPK/ERK pathways was examined by western blot analysis. Synergism assay was employed to determine whether combination of Oxyfadichalcone C with Vemurafenib would enhance the anti-proliferative effect. Oxyfadichalcone C potently inhibited proliferation, induced G1 phase arrest and weak apoptosis in A375 cells. Anti-migration and anti-invasion activities were also indicated. Such effects were associated with upregulation of p27, reduction of cyclin D1, p-pRb, p-Integrin β1, as well as the proteolytic activity of metalloproteinase (MMP)-2/9. Meanwhile, key molecules of PI3K/Akt and MAPK/ERK pathways were downregulated, which might be involved in the inhibition against proliferation and metastasis of A375 cells by Oxyfadichalcone C. In addition, combination of Oxyfadichalcone C with Vemurafenib at a ratio of IC50 Oxyfadichalcone C : 5 × IC 50 Vemurafenib exhibited synergistic anti-proliferative effect on A375 cells. Our findings suggest that Oxyfadichalcone C has the potential to be developed as a promising drug candidate for the treatment of melanoma. Copyright © 2018 Elsevier Inc. All rights reserved.

Establishment of a new cell line susceptible to Cyprinid herpesvirus 3 (CyHV-3) and possible latency of CyHV-3 by temperature shift in the cells.

Science.gov (United States)

Imajoh, M; Fujioka, H; Furusawa, K; Tamura, K; Yamasaki, K; Kurihara, S; Yamane, J; Kawai, K; Oshima, S

2015-06-01

A new cell line named CCF-K104 predominantly consisting of fibroblastic cells showed optimal growth at temperatures from 25 °C to 30 °C. Serial morphological changes in the cells induced by Cyprinid herpesvirus 3 (CyHV-3) included cytoplasmic vacuolar formation, cell rounding and detachment. Mature virions were purified from CyHV-3-infected CCF-K104 cells by sucrose gradient ultracentrifugation and had a typical herpesvirus structure on electron microscopy. Infectious CyHV-3 was produced stably in CCF-K104 cells over 30 viral passages. Our findings showed that CCF-K104 is a useful cell line for isolation and productive replication of CyHV-3. A temperature shift from 25 °C to 15 °C or 35 °C did not allow serial morphological changes as observed at 25 °C for 14 days. Under the same conditions, real-time PCR showed that CyHV-3 was present with low viral DNA loads, suggesting that CyHV-3 may establish latent infection in CCF-K104 cells. Amplification of the left and right terminal repeat sequences of the CyHV-3 genome arranged in a head-to-tail manner was detected by nested PCR following an upshift in temperature from 25 °C to 35 °C. The PCR results suggested that the circular genome may represent a latent form of CyHV-3. © 2014 John Wiley & Sons Ltd.

Lead facilitates foci formation in a Balb/c-3T3 two-step cell transformation model: role of Ape1 function.

Science.gov (United States)

Hernández-Franco, Pablo; Silva, Martín; Franco, Rodrigo; Valverde, Mahara; Rojas, Emilio

2018-04-01

Several possible mechanisms have been examined to gain an understanding on the carcinogenic properties of lead, which include among others, mitogenesis, alteration of gene expression, oxidative damage, and inhibition of DNA repair. The aim of the present study was to explore if low concentrations of lead, relevant for human exposure, interfere with Ape1 function, a base excision repair enzyme, and its role in cell transformation in Balb/c-3T3. Lead acetate 5 and 30 μM induced APE1 mRNA and upregulation of protein expression. This increase in mRNA expression is consistent throughout the chronic exposure. Additionally, we also found an impaired function of Ape1 through molecular beacon-based assay. To evaluate the impact of lead on foci formation, a Balb/c-3T3 two-step transformation model was used. Balb/c-3T3 cells were pretreated 1 week with low concentrations of lead before induction of transformation with n-methyl-n-nitrosoguanidine (MNNG) (0.5 μg/mL) and 12-O-tetradecanoylphorbol-13-acetate (TPA) (0.1 μg/mL) (a classical two-step protocol). Morphological cell transformation increased in response to lead pretreatment that was paralleled with an increase in Ape1 mRNA and protein overexpression and an impairment of Ape1 activity and correlating with foci number. In addition, we found that lead pretreatment and MNNG (transformation initiator) increased DNA damage, determined by comet assay. Our data suggest that low lead concentrations (5, 30 μM) could play a facilitating role in cellular transformation, probably through the impaired function of housekeeping genes such as Ape1, leading to DNA damage accumulation and chromosomal instability, one of the most important hallmarks of cancer induced by chronic exposures.

Enhanced tumor targeting of cRGD peptide-conjugated albumin nanoparticles in the BxPC-3 cell line.

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Yu, Xinzhe; Song, Yunlong; Di, Yang; He, Hang; Fu, Deliang; Jin, Chen

2016-08-12

The emerging albumin nanoparticle brings new hope for the delivery of antitumor drugs. However, a lack of robust tumor targeting greatly limits its application. In this paper, cyclic arginine-glycine-aspartic-conjugated, gemcitabine-loaded human serum albumin nanoparticles (cRGD-Gem-HSA-NPs) were successfully prepared, characterized, and tested in vitro in the BxPC-3 cell line. Initially, 4-N-myristoyl-gemcitabine (Gem-C14) was formed by conjugating myristoyl to the 4-amino group of gemcitabine. Then, cRGD-HSA was synthesized using sulfosuccinimidyl-(4-N-maleimidomethyl)cyclohexane-1-carboxylate (Sulfo-SMCC) cross-linkers. Finally, cRGD-Gem-HSA-NPs were formulated based on the nanoparticle albumin-bound (nab) technology. The resulting NPs were characterized for particle size, zeta potential, morphology, encapsulation efficiency, and drug loading efficiency. In vitro cellular uptake and inhibition studies were conducted to compare Gem-HSA-NPs and cRGD-Gem-HSA-NPs in a human pancreatic cancer cell line (BxPC-3). The cRGD-Gem-HSA-NPs exhibited an average particle size of 160 ± 23 nm. The encapsulation rate and drug loading rate were approximately 83 ± 5.6% and 11 ± 4.2%, respectively. In vitro, the cRGD-anchored NPs exhibited a significantly greater affinity for the BxPC-3 cells compared to non-targeted NPs and free drug. The cRGD-Gem-HSA-NPs also showed the strongest inhibitory effect in the BxPC-3 cells among all the analyzed groups. The improved efficacy of cRGD-Gem-HSA-NPs in the BxPC-3 cell line warrants further in vivo investigations.

Conserved cell cycle regulatory properties within the amino terminal domain of the Epstein-Barr virus nuclear antigen 3C

International Nuclear Information System (INIS)

Sharma, Nikhil; Knight, Jason S.; Robertson, Erle S.

2006-01-01

The gammaherpesviruses Rhesus lymphocryptovirus (LCV) and Epstein-Barr virus (EBV) are closely related phylogenetically. Rhesus LCV efficiently immortalizes Rhesus B cells in vitro. However, despite a high degree of conservation between the Rhesus LCV and EBV genomes, Rhesus LCV fails to immortalize human B cells in vitro. This species restriction may, at least in part, be linked to the EBV nuclear antigens (EBNAs) and latent membrane proteins (LMPs), known to be essential for B cell transformation. We compared specific properties of EBNA3C, a well-characterized and essential EBV protein, with its Rhesus counterpart to determine whether EBNA3C phenotypes which contribute to cell cycle regulation are conserved in the Rhesus LCV. We show that both EBNA3C and Rhesus EBNA3C bind to a conserved region of mammalian cyclins, regulate pRb stability, and modulate SCF Skp2 -dependent ubiquitination. These results suggest that Rhesus LCV restriction from human B cell immortalization is independent of the conserved cell cycle regulatory functions of the EBNA3C protein

Preparation of Proper Immunogen by Cloning and Stable Expression of cDNA coding for Human Hematopoietic Stem Cell Marker CD34 in NIH-3T3 Mouse Fibroblast Cell Line

Science.gov (United States)

Shafaghat, Farzaneh; Abbasi-Kenarsari, Hajar; Majidi, Jafar; Movassaghpour, Ali Akbar; Shanehbandi, Dariush; Kazemi, Tohid

2015-01-01

Purpose: Transmembrane CD34 glycoprotein is the most important marker for identification, isolation and enumeration of hematopoietic stem cells (HSCs). We aimed in this study to clone the cDNA coding for human CD34 from KG1a cell line and stably express in mouse fibroblast cell line NIH-3T3. Such artificial cell line could be useful as proper immunogen for production of mouse monoclonal antibodies. Methods: CD34 cDNA was cloned from KG1a cell line after total RNA extraction and cDNA synthesis. Pfu DNA polymerase-amplified specific band was ligated to pGEMT-easy TA-cloning vector and sub-cloned in pCMV6-Neo expression vector. After transfection of NIH-3T3 cells using 3 μg of recombinant construct and 6 μl of JetPEI transfection reagent, stable expression was obtained by selection of cells by G418 antibiotic and confirmed by surface flow cytometry. Results: 1158 bp specific band was aligned completely to reference sequence in NCBI database corresponding to long isoform of human CD34. Transient and stable expression of human CD34 on transfected NIH-3T3 mouse fibroblast cells was achieved (25% and 95%, respectively) as shown by flow cytometry. Conclusion: Cloning and stable expression of human CD34 cDNA was successfully performed and validated by standard flow cytometric analysis. Due to murine origin of NIH-3T3 cell line, CD34-expressing NIH-3T3 cells could be useful as immunogen in production of diagnostic monoclonal antibodies against human CD34. This approach could bypass the need for purification of recombinant proteins produced in eukaryotic expression systems. PMID:25789221

Comparison of heat and/or radiation sensitivity and membrane composition of seven X-ray-transformed C3H 10T1/2 cell lines and normal C3H 10T1/2 cells

International Nuclear Information System (INIS)

Raaphorst, G.P.; Vadasz, J.A.; Azzam, E.I.; Sargent, M.D.; Borsa, J.; Einspenner, M.

1985-01-01

C3H 10T1/2 mouse embryo cells were transformed by X-irradiation, and seven transformed clones were isolated and propagated as cell lines. Some of these cell lines produced tumors in syngeneic mice and grew in agarose while the normal C3H 10T1/2 cell line did not possess these characteristics. Exponentially growing cell cultures with comparable cell-cycle distributions as measured by flow cytometry were tested for heat and X-ray sensitivity. The heat and X-ray sensitivity varied randomly compared to the normal cell line. One cell line was more heat resistant and one more heat sensitive than the normal cell line, and the others had sensitivities comparable to the normal cell line. Measurements on some of the biochemical parameters of the particulate fraction of cells after sonication and 24,000 X g centrifugation showed that altered thermal sensitivity was not correlated with protein, cholesterol, or phospholipid content of this fraction

Dopamine-induced programmed cell death is associated with cytochrome c release and caspase-3 activation in snail salivary gland cells.

Science.gov (United States)

Pirger, Zsolt; Rácz, Boglárka; Kiss, Tibor

2009-02-01

PCD (programmed cell death) is a common mechanism to remove unwanted and excessive cells from organisms. In several exocrine cell types, PCD mode of release of secretory products has been reported. The molecular mechanism of the release, however, is largely unknown. Our aim was to study the molecular mechanism of saliva release from cystic cells, the specific cell type of snail SGs (salivary glands). SG cells in active feeding animals revealed multiple morphological changes characteristic of PCD. Nerve stimulation and DA (dopamine) increased the number of TUNEL (terminal deoxynucleotidyl transferase-mediated dUTP nick-end labelling)-positive cells both in inactive and feeding animals. The DA-induced PCD was prevented by TEA (tetraethylammonium chloride) and eticlopride, emphasizing the role of K channels and D2 receptors in the PCD of cystic cells. DA enhanced cyto-c (cytochrome c) translocation into the cytosol and methyl-beta-cyclodextrin prevented it, suggesting apoptosome formation and ceramide involvement in the PCD linking of the surface DA receptor to mitochondria. Western blot analysis revealed that the release of cyto-c was under the control of Bcl-2 and Bad. DA also increased the active caspase-3 in gland cells while D2 receptor antagonists and TEA attenuated it. Our results provide evidence for a type of transmitter-mediated pathway that regulates the PCD of secretory cells in a mitochondrial-caspase-dependent manner. The activation of specific molecules, such as K channels, DA receptors, cyto-c, ceramide, Bcl-2 proteins and caspase-3, but not caspase-8, was demonstrated in cells involved in the DA-induced PCD, suggesting that PCD is a physiological method for the release of saliva from SG cells.

Isoorientin induces apoptosis through mitochondrial dysfunction and inhibition of PI3K/Akt signaling pathway in HepG2 cancer cells

International Nuclear Information System (INIS)

Yuan, Li; Wang, Jing; Xiao, Haifang; Xiao, Chunxia; Wang, Yutang; Liu, Xuebo

2012-01-01

Isoorientin (ISO) is a flavonoid compound that can be extracted from several plant species, such as Phyllostachys pubescens, Patrinia, and Drosophyllum lusitanicum; however, its biological activity remains poorly understood. The present study investigated the effects and putative mechanism of apoptosis induced by ISO in human hepatoblastoma cancer (HepG2) cells. The results showed that ISO induced cell death in a dose-dependent manner in HepG2 cells, but no toxicity in human liver cells (HL-7702) and buffalo rat liver cells (BRL-3A) treated with ISO at the indicated concentrations. ISO-induced cell death included apoptosis which characterized by the appearance of nuclear shrinkage, the cleavage of poly (ADP-ribose) polymerase (PARP) and DNA fragmentation. ISO significantly (p < 0.01) increased the Bax/Bcl-2 ratio, disrupted the mitochondrial membrane potential (MMP), increased the release of cytochrome c, activated caspase-3, and enhanced intracellular levels of reactive oxygen species (ROS) and nitric oxide (NO). In addition, ISO effectively inhibited the phosphorylation of Akt and increased FoxO4 expression. The PI3K/Akt inhibitor LY294002 enhanced the apoptosis-inducing effect of ISO. However, LY294002 markedly quenched ROS and NO generation and diminished the protein expression of heme peroxidase enzyme (HO-1) and inducible nitric oxide synthase (iNOS). Furthermore, the addition of a ROS inhibitor (N-acetyl cysteine, NAC) or iNOS inhibitor (N-[3-(aminomethyl) benzyl] acetamidine, dihydrochloride, 1400W) significantly diminished the apoptosis induced by ISO and also blocked the phosphorylation of Akt. These results demonstrated for the first time that ISO induces apoptosis in HepG2 cells and indicate that this apoptosis might be mediated through mitochondrial dysfunction and PI3K/Akt signaling pathway, and has no toxicity in normal liver cells, suggesting that ISO may have good potential as a therapeutic and chemopreventive agent for liver cancer. Highlights: �

2′,3′-cAMP, 3′-AMP, and 2′-AMP inhibit human aortic and coronary vascular smooth muscle cell proliferation via A2B receptors

Science.gov (United States)

Ren, Jin; Gillespie, Delbert G.

2011-01-01

Rat vascular smooth muscle cells (VSMCs) from renal microvessels metabolize 2′,3′-cAMP to 2′-AMP and 3′-AMP, and these AMPs are converted to adenosine that inhibits microvascular VSMC proliferation via A2B receptors. The goal of this study was to test whether this mechanism also exists in VSMCs from conduit arteries and whether it is similarly expressed in human vs. rat VSMCs. Incubation of rat and human aortic VSMCs with 2′,3′-cAMP concentration-dependently increased levels of 2′-AMP and 3′-AMP in the medium, with a similar absolute increase in 2′-AMP vs. 3′-AMP. In contrast, in human coronary VSMCs, 2′,3′-cAMP increased 2′-AMP levels yet had little effect on 3′-AMP levels. In all cell types, 2′,3′-cAMP increased levels of adenosine, but not 5′-AMP, and 2′,3′-AMP inhibited cell proliferation. Antagonism of A2B receptors (MRS-1754), but not A1 (1,3-dipropyl-8-cyclopentylxanthine), A2A (SCH-58261), or A3 (VUF-5574) receptors, attenuated the antiproliferative effects of 2′,3′-cAMP. In all cell types, 2′-AMP, 3′-AMP, and 5′-AMP increased adenosine levels, and inhibition of ecto-5′-nucleotidase blocked this effect of 5′-AMP but not that of 2′-AMP nor 3′-AMP. Also, 2′-AMP, 3′-AMP, and 5′-AMP, like 2′,3′-cAMP, exerted antiproliferative effects that were abolished by antagonism of A2B receptors with MRS-1754. In conclusion, VSMCs from conduit arteries metabolize 2′,3′-cAMP to AMPs, which are metabolized to adenosine. In rat and human aortic VSMCs, both 2′-AMP and 3′-AMP are involved in this process, whereas, in human coronary VSMCs, 2′,3′-cAMP is mainly converted to 2′-AMP. Because adenosine inhibits VSMC proliferation via A2B receptors, local vascular production of 2′,3′-cAMP may protect conduit arteries from atherosclerosis. PMID:21622827

Cytochalasin E alters the cytoskeleton and decreases ENaC activity in Xenopus 2F3 cells.

Science.gov (United States)

Reifenberger, Matthew S; Yu, Ling; Bao, Hui-Fang; Duke, Billie Jeanne; Liu, Bing-Chen; Ma, He-Ping; Alli, Ahmed A; Eaton, Douglas C; Alli, Abdel A

2014-07-01

Numerous reports have linked cytoskeleton-associated proteins with the regulation of epithelial Na(+) channel (ENaC) activity. The purpose of the present study was to determine the effect of actin cytoskeleton disruption by cytochalasin E on ENaC activity in Xenopus 2F3 cells. Here, we show that cytochalasin E treatment for 60 min can disrupt the integrity of the actin cytoskeleton in cultured Xenopus 2F3 cells. We show using single channel patch-clamp experiments and measurements of short-circuit current that ENaC activity, but not its density, is altered by cytochalasin E-induced disruption of the cytoskeleton. In nontreated cells, 8 of 33 patches (24%) had no measurable ENaC activity, whereas in cytochalasin E-treated cells, 17 of 32 patches (53%) had no activity. Analysis of those patches that did contain ENaC activity showed channel open probability significantly decreased from 0.081 ± 0.01 in nontreated cells to 0.043 ± 0.01 in cells treated with cytochalasin E. Transepithelial current from mpkCCD cells treated with cytochalasin E, cytochalasin D, or latrunculin B for 60 min was decreased compared with vehicle-treated cells. The subcellular expression of fodrin changed significantly, and several protein elements of the cytoskeleton decreased at least twofold after 60 min of cytochalasin E treatment. Cytochalasin E treatment disrupted the association between ENaC and myristoylated alanine-rich C-kinase substrate. The results presented here suggest disruption of the actin cytoskeleton by different compounds can attenuate ENaC activity through a mechanism involving changes in the subcellular expression of fodrin, several elements of the cytoskeleton, and destabilization of the ENaC-myristoylated alanine-rich C-kinase substrate complex. Copyright © 2014 the American Physiological Society.

Dendritic cells induce specific cytotoxic T lymphocytes against prostate cancer TRAMP-C2 cells loaded with freeze- thaw antigen and PEP-3 peptide.

Science.gov (United States)

Liu, Xiao-Qi; Jiang, Rong; Li, Si-Qi; Wang, Jing; Yi, Fa-Ping

2015-01-01

Prostate cancer is the most common cancer in men. In this study, we investigated immune responses of cytotoxic T lymphocytes (CTLs) against TRAMP-C2 prostate cancer cells after activation by dendritic cells (DCs) loaded with TRAMP-C2 freeze-thaw antigen and/or PEP-3 peptide in vitro. Bone marrow-derived DC from the bone marrow of the C57BL/6 were induced to mature by using the cytokine of rhGM-CSF and rhIL-4, and loaded with either the freeze-thaw antigen or PEP-3 peptide or both of them. Maturation of DCs was detected by flow cytometry. The killing efficiency of the CTLs on TRAMP-C2 cells were detected by flow cytometry, CCK8, colony formation, transwell migration, and wound-healing assay. The levels of the IFN-γ, TNF-β and IL-12 were measured by enzyme-linked immunosorbent assay (ELISA). Compared with the unloaded DCs, the loaded DCs had significantly increased expression of several phenotypes related to DC maturation. CTLs activated by DCs loaded with freeze-thaw antigen and PEP-3 peptide had more evident cytotoxicity against TRAMP-C2 cells in vitro. The secretion levels of IFN-γ, TNF-β and IL-12, secreted by DCs loaded with antigen and PEP-3 and interaction with T cells, were higher than in the other groups. Our results suggest that the CTLs activated by DCs loaded with TRAMP-C2 freeze-thaw antigen and PEP-3 peptide exert a remarkable killing efficiency against TRAMP-C2 cells in vitro.

Foxp3⁺ regulatory T cells delay expulsion of intestinal nematodes by suppression of IL-9-driven mast cell activation in BALB/c but not in C57BL/6 mice.

Science.gov (United States)

Blankenhaus, Birte; Reitz, Martina; Brenz, Yannick; Eschbach, Marie-Luise; Hartmann, Wiebke; Haben, Irma; Sparwasser, Tim; Huehn, Jochen; Kühl, Anja; Feyerabend, Thorsten B; Rodewald, Hans-Reimer; Breloer, Minka

2014-02-01

Accumulating evidence suggests that IL-9-mediated immunity plays a fundamental role in control of intestinal nematode infection. Here we report a different impact of Foxp3⁺ regulatory T cells (Treg) in nematode-induced evasion of IL-9-mediated immunity in BALB/c and C57BL/6 mice. Infection with Strongyloides ratti induced Treg expansion with similar kinetics and phenotype in both strains. Strikingly, Treg depletion reduced parasite burden selectively in BALB/c but not in C57BL/6 mice. Treg function was apparent in both strains as Treg depletion increased nematode-specific humoral and cellular Th2 response in BALB/c and C57BL/6 mice to the same extent. Improved resistance in Treg-depleted BALB/c mice was accompanied by increased production of IL-9 and accelerated degranulation of mast cells. In contrast, IL-9 production was not significantly elevated and kinetics of mast cell degranulation were unaffected by Treg depletion in C57BL/6 mice. By in vivo neutralization, we demonstrate that increased IL-9 production during the first days of infection caused accelerated mast cell degranulation and rapid expulsion of S. ratti adults from the small intestine of Treg-depleted BALB/c mice. In genetically mast cell-deficient (Cpa3-Cre) BALB/c mice, Treg depletion still resulted in increased IL-9 production but resistance to S. ratti infection was lost, suggesting that IL-9-driven mast cell activation mediated accelerated expulsion of S. ratti in Treg-depleted BALB/c mice. This IL-9-driven mast cell degranulation is a central mechanism of S. ratti expulsion in both, BALB/c and C57BL/6 mice, because IL-9 injection reduced and IL-9 neutralization increased parasite burden in the presence of Treg in both strains. Therefore our results suggest that Foxp3⁺ Treg suppress sufficient IL-9 production for subsequent mast cell degranulation during S. ratti infection in a non-redundant manner in BALB/c mice, whereas additional regulatory pathways are functional in Treg-depleted C57BL/6

CLA isomer t10,c12 induce oxidation and apoptosis in 3t3 adipocyte cells in a similar effect as omega-3 linolenic acid and DHA.

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Jon Meadus

2017-02-01

Full Text Available Background: Commercial conjugated linoleic acid (CLA dietary supplements contain an equal mixture of the C18:2 isomers, cis-9trans-11 and trans-10cis-12. Predominantly, CLA-c9t11 occurs naturally in meat and dairy products at ~ 0.5% of total fat , whereas CLA-t10c12 occurs at >0.1%. Recent studies show that CLA-c9t11 generally promotes lipid accumulation but CLA-t10c12 may inhibit lipid accumulation and may also promote inflammation. The omega-3 fatty acids α-linolenic acid (C18:3n-3 and docosahexaenoic acid (DHA have also been observed to inhibit lipid accumulation and effect inflammation; therefore we examined the effects of the two main isomersof CLA and omega -3 fatty acids C18:3n-3 and DHA at the molecular levelto determine if they are causing similar oxidative stresses.Methods:Purified CLA-c9t11 and CLA-t10c12 were added to 3T3 cells induced into mature adipocyte cultures at 100uM concentrations and compared with 100uM C18:3n-3(α-linolenic acid and 50uM docosahexaenoic acid (DHA to observe their effect on growth, gene transcription and general oxidation. The results of multiple separate trials were averaged and compared for significance at levels of P< 0.05, using one way ANOVA and Student’s t-test.Results:C18:3n-3, DHA and CLA-t10c12inhibited 3T3 adipose cell growth and caused a significant increase in lipid hydro peroxide activity. CLA-t10c12 and c9t11 increased AFABP, FAS and ACOX1 mRNA gene expression but DHA and C18:3n-3decreased the same mRNAs. CLA-c9t11 but not the t10c12 stimulated adipoQ expression even though; CLA-c9t11 had only a slightly greater affinity for PPARγ than CLA-t10c12, according to TR-FRET assays. The expression of the xenobiotic metabolism genes, aldo-keto reduct as 1c1 (akr1c1, superoxide dismutase (SODand inflammation chemokine secretions of eotaxin (CCL11, Rantes (CCL5, MIG (CCL9 and MCP-1 were increased by DHA, C18:3n-3and CLA-t10c12 but not CLA-c9t11. This correlated with an increase in apoptosis factors

Toxic mechanisms of 3-monochloropropane-1,2-diol on progesterone production in R2C rat leydig cells.

Science.gov (United States)

Sun, Jianxia; Bai, Shun; Bai, Weibin; Zou, Feiyan; Zhang, Lei; Su, Zhijian; Zhang, Qihao; Ou, Shiyi; Huang, Yadong

2013-10-16

3-Monochloropropane-1,2-diol (3-MCPD) is a well-known food processing contaminant that has been shown to impede the male reproductive function. However, its mechanism of action remains to be elucidated. In this study, the effects of 3-MCPD on progesterone production were investigated using R2C Leydig cells. 3-MCPD caused concentration-dependent inhibition of cell viability at the IC25, IC50, and IC75 levels of 1.027, 1.802, and 3.160 mM, respectively. Single cell gel/comet assay and atomic force microscopy assay showed that 3-MCPD significantly induced early apoptosis. In addition, 3-MCPD significantly reduced progesterone production by reducing the expression of cytochrome P450 side-chain cleavage enzyme, steroidogenic acute regulatory protein, and 3β-hydroxysteroid dehydrogenase in R2C cells. The change in steroidogenic acute regulatory protein expression was highly consistent with progesterone production. Furthermore, the mitochondrial membrane potential and cAMP significantly decreased.

Insights into Substrate Specificity of NlpC/P60 Cell Wall Hydrolases Containing Bacterial SH3 Domains

Energy Technology Data Exchange (ETDEWEB)

Xu, Qingping; Mengin-Lecreulx, Dominique; Liu, Xueqian W.; Patin, Delphine; Farr, Carol L.; Grant, Joanna C.; Chiu, Hsiu-Ju; Jaroszewski, Lukasz; Knuth, Mark W.; Godzik, Adam; Lesley, Scott A.; Elsliger, Marc-André; Deacon, Ashley M.; Wilson, Ian A.

2015-09-15

Bacterial SH3 (SH3b) domains are commonly fused with papain-like Nlp/P60 cell wall hydrolase domains. To understand how the modular architecture of SH3b and NlpC/P60 affects the activity of the catalytic domain, three putative NlpC/P60 cell wall hydrolases were biochemically and structurally characterized. These enzymes all have γ-d-Glu-A₂pm (A₂pm is diaminopimelic acid) cysteine amidase (ordl-endopeptidase) activities but with different substrate specificities. One enzyme is a cell wall lysin that cleaves peptidoglycan (PG), while the other two are cell wall recycling enzymes that only cleave stem peptides with an N-terminall-Ala. Their crystal structures revealed a highly conserved structure consisting of two SH3b domains and a C-terminal NlpC/P60 catalytic domain, despite very low sequence identity. Interestingly, loops from the first SH3b domain dock into the ends of the active site groove of the catalytic domain, remodel the substrate binding site, and modulate substrate specificity. Two amino acid differences at the domain interface alter the substrate binding specificity in favor of stem peptides in recycling enzymes, whereas the SH3b domain may extend the peptidoglycan binding surface in the cell wall lysins. Remarkably, the cell wall lysin can be converted into a recycling enzyme with a single mutation.

IMPORTANCEPeptidoglycan is a meshlike polymer that envelops the bacterial plasma membrane and bestows structural integrity. Cell wall lysins and recycling enzymes are part of a set of lytic enzymes that target covalent bonds connecting the amino acid and amino sugar building blocks of the PG network. These hydrolases are involved in processes such as cell growth and division, autolysis, invasion, and PG turnover and recycling. To avoid cleavage of unintended substrates, these enzymes have very selective substrate specificities. Our biochemical and structural

Triple Layer Antireflection Design Concept for the Front Side of c-Si Heterojunction Solar Cell Based on the Antireflective Effect of nc-3C-SiC:H Emitter Layer

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Erick Omondi Ateto

2016-01-01

Full Text Available We investigated the antireflective (AR effect of hydrogenated nanocrystalline cubic silicon carbide (nc-3C-SiC:H emitter and its application in the triple layer AR design for the front side of silicon heterojunction (SHJ solar cell. We found that the nc-3C-SiC:H emitter can serve both as an emitter and antireflective coating for SHJ solar cell, which enables us to realize the triple AR design by adding one additional dielectric layer to normally used SHJ structure with a transparent conductive oxide (TCO and an emitter layer. The optimized SHJ structure with the triple layer AR coating (LiF/ITO/nc-3C-SiC:H exhibit a short circuit current density (Jsc of 38.65 mA/cm2 and lower reflectivity of about 3.42% at wavelength range of 300 nm–1000 nm.

Generation of a C3c specific monoclonal antibody and assessment of C3c as a putative inflammatory marker derived from complement factor C3

DEFF Research Database (Denmark)

Palarasah, Yaseelan; Skjodt, Karsten; Brandt, Jette

2010-01-01

complex (C5b-C9) and quantification of complement split products by precipitation-in-gel techniques (e.g. C3d). We have developed a mouse monoclonal antibody (mAb) that is able to detect fluid phase C3c without interference from other products generated from the complement component C3. The C3c specific m....... The C3c mAb was confirmed to be C3c specific, as it showed no cross-reactivity with native (un-cleaved) C3, with C3b, iC3b, or with C3d. Also, no significant reaction was observed with C3 fragments in factor I deficient sera or plasma. This antibody forms the basis for the generation of a robust ELISA...... that allows for a quick and reliable evaluation of complement activation and consumption as a marker for inflammatory processes. We established the C3c plasma range in 100 healthy Danish blood donors with a mean of 3.47 μg/ml and a range of 2.12-4.92 μg/ml. We believe that such an antibody might...

Foxp3⁺ regulatory T cells delay expulsion of intestinal nematodes by suppression of IL-9-driven mast cell activation in BALB/c but not in C57BL/6 mice.

Directory of Open Access Journals (Sweden)

Birte Blankenhaus

2014-02-01

Full Text Available Accumulating evidence suggests that IL-9-mediated immunity plays a fundamental role in control of intestinal nematode infection. Here we report a different impact of Foxp3⁺ regulatory T cells (Treg in nematode-induced evasion of IL-9-mediated immunity in BALB/c and C57BL/6 mice. Infection with Strongyloides ratti induced Treg expansion with similar kinetics and phenotype in both strains. Strikingly, Treg depletion reduced parasite burden selectively in BALB/c but not in C57BL/6 mice. Treg function was apparent in both strains as Treg depletion increased nematode-specific humoral and cellular Th2 response in BALB/c and C57BL/6 mice to the same extent. Improved resistance in Treg-depleted BALB/c mice was accompanied by increased production of IL-9 and accelerated degranulation of mast cells. In contrast, IL-9 production was not significantly elevated and kinetics of mast cell degranulation were unaffected by Treg depletion in C57BL/6 mice. By in vivo neutralization, we demonstrate that increased IL-9 production during the first days of infection caused accelerated mast cell degranulation and rapid expulsion of S. ratti adults from the small intestine of Treg-depleted BALB/c mice. In genetically mast cell-deficient (Cpa3-Cre BALB/c mice, Treg depletion still resulted in increased IL-9 production but resistance to S. ratti infection was lost, suggesting that IL-9-driven mast cell activation mediated accelerated expulsion of S. ratti in Treg-depleted BALB/c mice. This IL-9-driven mast cell degranulation is a central mechanism of S. ratti expulsion in both, BALB/c and C57BL/6 mice, because IL-9 injection reduced and IL-9 neutralization increased parasite burden in the presence of Treg in both strains. Therefore our results suggest that Foxp3⁺ Treg suppress sufficient IL-9 production for subsequent mast cell degranulation during S. ratti infection in a non-redundant manner in BALB/c mice, whereas additional regulatory pathways are functional in

Metabolism of 4-/sup 14/C-dehydroepiandrosterone and 4-/sup 14/C-4-Androstene-3, 17-dione by isolated cells of early human placenta

Energy Technology Data Exchange (ETDEWEB)

Dziadkowiec, I; Czarnik, Z; Rembiesa, R [Department of Endocrinology, Institute of Pharmacology, Polish Academy of Sciences, Krakow

1977-03-01

The preparation of isolated cells was used for the study of the metabolism of 4-/sup 14/C-dehydroepiandrosterone and 4-/sup 14/C-4-androstene-3,17-dione in early human placenta. Free cell suspension converted dehydroepiandrosterone and 4-androstene-3,17-dione into estrone, estradiol-17..beta.., 4-androstene-3,17-dione and testosterone.

miR-29c targets TNFAIP3, inhibits cell proliferation and induces apoptosis in hepatitis B virus-related hepatocellular carcinoma

International Nuclear Information System (INIS)

Wang, Chun-Mei; Wang, Yan; Fan, Chun-Guang; Xu, Fei-Fei; Sun, Wen-Sheng; Liu, Yu-Gang; Jia, Ji-Hui

2011-01-01

Highlights: → miR-29c was significantly downregulated in HBV-related HCC. → TNFAIP3 was found to be inversely correlated with miR-29c levels and identified as a target of miR-29c. → Overexpression of miR-29c suppressed TNFAIP3. → miR-29c inhibited HBV DNA replication, cell proliferation and induced apoptosis. -- Abstract: Recent studies have revealed that microRNA-29c (miR-29c) is involved in a variety of biological processes including carcinogenesis. Here, we report that miR-29c was significantly downregulated in hepatitis B virus (HBV)-related hepatocellular carcinoma (HCC) cell lines as well as in clinical tissues compared with their corresponding controls. Tumor necrosis factor alpha-induced protein 3 (TNFAIP3), a key regulator in inflammation and immunity, was found to be inversely correlated with miR-29c levels and was identified as a target of miR-29c. Overexpression of miR-29c in HepG2.2.15 cells effectively suppressed TNFAIP3 expression and HBV DNA replication as well as inhibited cell proliferation and induced apoptosis. We conclude that miR-29c may play an important role as a tumor suppressive microRNA in the development and progression of HBV-related HCC by targeting TNFAIP3. Thus miR-29c and TNFAIP3 represent key diagnostic markers and potential therapeutic targets for the prevention and treatment of HBV infection.

miR-29c targets TNFAIP3, inhibits cell proliferation and induces apoptosis in hepatitis B virus-related hepatocellular carcinoma

Energy Technology Data Exchange (ETDEWEB)

Wang, Chun-Mei [Department of Microbiology, Shandong University School of Medicine, Jinan 250012 (China); Department of Pathophysiology, Shandong University School of Medicine, Jinan 250012 (China); Wang, Yan; Fan, Chun-Guang; Xu, Fei-Fei [Department of Pathophysiology, Shandong University School of Medicine, Jinan 250012 (China); Sun, Wen-Sheng [Institute of Immunology, Shandong University School of Medicine, Jinan 250012 (China); Liu, Yu-Gang, E-mail: liu.yugang@sdu.edu.cn [Department of Pathophysiology, Shandong University School of Medicine, Jinan 250012 (China); Jia, Ji-Hui, E-mail: jiajihui@sdu.edu.cn [Department of Microbiology, Shandong University School of Medicine, Jinan 250012 (China)

2011-08-05

Highlights: {yields} miR-29c was significantly downregulated in HBV-related HCC. {yields} TNFAIP3 was found to be inversely correlated with miR-29c levels and identified as a target of miR-29c. {yields} Overexpression of miR-29c suppressed TNFAIP3. {yields} miR-29c inhibited HBV DNA replication, cell proliferation and induced apoptosis. -- Abstract: Recent studies have revealed that microRNA-29c (miR-29c) is involved in a variety of biological processes including carcinogenesis. Here, we report that miR-29c was significantly downregulated in hepatitis B virus (HBV)-related hepatocellular carcinoma (HCC) cell lines as well as in clinical tissues compared with their corresponding controls. Tumor necrosis factor alpha-induced protein 3 (TNFAIP3), a key regulator in inflammation and immunity, was found to be inversely correlated with miR-29c levels and was identified as a target of miR-29c. Overexpression of miR-29c in HepG2.2.15 cells effectively suppressed TNFAIP3 expression and HBV DNA replication as well as inhibited cell proliferation and induced apoptosis. We conclude that miR-29c may play an important role as a tumor suppressive microRNA in the development and progression of HBV-related HCC by targeting TNFAIP3. Thus miR-29c and TNFAIP3 represent key diagnostic markers and potential therapeutic targets for the prevention and treatment of HBV infection.

Prostate cancer cells induce osteoblastic differentiation via semaphorin 3A.

Science.gov (United States)

Liu, Fuzhou; Shen, Weiwei; Qiu, Hao; Hu, Xu; Zhang, Chao; Chu, Tongwei

2015-03-01

Prostate cancer metastasis to bone is the second most commonly diagnosed malignant disease among men worldwide. Such metastatic disease is characterized by the presence of osteoblastic bone lesions, and is associated with high rates of mortality. However, the various mechanisms involved in prostate cancer-induced osteoblastic differentiation have not been fully explored. Semaphorin 3A (Sema 3A) is a newly identified regulator of bone metabolism which stimulates differentiation of pre-osteoblastic cells under physiological conditions. We investigated in this study whether prostate cancer cells can mediate osteoblastic activity through Sema 3A. We cultured osteoprogenitor MC3T3-E1 cells in prostate cancer-conditioned medium, and analyzed levels of Sema 3A protein in diverse prostate cancer cell lines to identify cell lines in which Sema 3A production showed a positive correlation with osteo-stimulation. C4-2 cells were stably transfected with Sema 3A short hairpin RNA to further determine whether Sema 3A contributes to the ability of C4-2 cells to induce osteoblastic differentiation. Down-regulation of Sema 3A expression decreased indicators of C4-2 CM-induced osteoblastic differentiation, including alkaline phosphatase production and mineralization. Additionally, silencing or neutralizing Sema 3A in C4-2 cells resulted in diminished β-catenin expression in osteogenitor MC3T3-E1 cells. Our results suggest that prostate cancer-induced osteoblastic differentiation is at least partially mediated by Sema 3A, and may be regulated by the β-catenin signalling pathway. Sema 3A may represent a novel target for treatment of prostate cancer-induced osteoblastic lesions. © 2014 Wiley Periodicals, Inc.

Fibulin-3 negatively regulates ALDH1 via c-MET suppression and increases γ-radiation-induced sensitivity in some pancreatic cancer cell lines

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Kim, In-Gyu, E-mail: igkim@kaeri.re.kr [Department of Radiation Biology, Environmental Radiation Research Group, Korea Atomic Energy Research Institute, 989-111 Daedeok-daero, Yuseong-gu, Daejeon 305-353 (Korea, Republic of); Department of Radiation Biotechnology and Applied Radioisotope, Korea University of Science and Technology (UST), 989-111 Daedeok-daero, Yusong-gu, Daejeon 305-353 (Korea, Republic of); Lee, Jae-Ha [Department of Radiation Biology, Environmental Radiation Research Group, Korea Atomic Energy Research Institute, 989-111 Daedeok-daero, Yuseong-gu, Daejeon 305-353 (Korea, Republic of); Department of Radiation Biotechnology and Applied Radioisotope, Korea University of Science and Technology (UST), 989-111 Daedeok-daero, Yusong-gu, Daejeon 305-353 (Korea, Republic of); Kim, Seo-Yoen; Kim, Jeong-Yul [Department of Radiation Biology, Environmental Radiation Research Group, Korea Atomic Energy Research Institute, 989-111 Daedeok-daero, Yuseong-gu, Daejeon 305-353 (Korea, Republic of); Cho, Eun-Wie [Epigenomics Research Center, Korea Research Institute of Bioscience and Biotechnology, 125 Gwahak-ro, Yuseong-gu, Daejeon 305-806 (Korea, Republic of)

2014-11-21

Highlights: • FBLN-3 gene was poorly expressed in some pancreatic cancer lines. • FBLN-3 promoter region was highly methylated in some pancreatic cancer cell lines. • FBLN-3 inhibited c-MET activation and expression and reduced cellular level of ALDH1. • FBLN-3/c-Met/ALDH1 axis modulates stemness and EMT in pancreatic cancer cells. - Abstract: Fibulin-3 (FBLN-3) has been postulated to be either a tumor suppressor or promoter depending on the cell type, and hypermethylation of the FBLN-3 promoter is often associated with human disease, especially cancer. We report that the promoter region of the FBLN-3 was significantly methylated (>95%) in some pancreatic cancer cell lines and thus FBLN-3 was poorly expressed in pancreatic cancer cell lines such as AsPC-1 and MiaPaCa-2. FBLN-3 overexpression significantly down-regulated the cellular level of c-MET and inhibited hepatocyte growth factor-induced c-MET activation, which were closely associated with γ-radiation resistance of cancer cells. Moreover, we also showed that c-MET suppression or inactivation decreased the cellular level of ALDH1 isozymes (ALDH1A1 or ALDH1A3), which serve as cancer stem cell markers, and subsequently induced inhibition of cell growth in pancreatic cancer cells. Therefore, forced overexpression of FBLN-3 sensitized cells to cytotoxic agents such as γ-radiation and strongly inhibited the stemness and epithelial to mesenchymal transition (EMT) property of pancreatic cancer cells. On the other hand, if FBLN3 was suppressed in FBLN-3-expressing BxPC3 cells, the results were opposite. This study provides the first demonstration that the FBLN-3/c-MET/ALDH1 axis in pancreatic cancer cells partially modulates stemness and EMT as well as sensitization of cells to the detrimental effects of γ-radiation.

Fibulin-3 negatively regulates ALDH1 via c-MET suppression and increases γ-radiation-induced sensitivity in some pancreatic cancer cell lines

International Nuclear Information System (INIS)

Kim, In-Gyu; Lee, Jae-Ha; Kim, Seo-Yoen; Kim, Jeong-Yul; Cho, Eun-Wie

2014-01-01

Highlights: • FBLN-3 gene was poorly expressed in some pancreatic cancer lines. • FBLN-3 promoter region was highly methylated in some pancreatic cancer cell lines. • FBLN-3 inhibited c-MET activation and expression and reduced cellular level of ALDH1. • FBLN-3/c-Met/ALDH1 axis modulates stemness and EMT in pancreatic cancer cells. - Abstract: Fibulin-3 (FBLN-3) has been postulated to be either a tumor suppressor or promoter depending on the cell type, and hypermethylation of the FBLN-3 promoter is often associated with human disease, especially cancer. We report that the promoter region of the FBLN-3 was significantly methylated (>95%) in some pancreatic cancer cell lines and thus FBLN-3 was poorly expressed in pancreatic cancer cell lines such as AsPC-1 and MiaPaCa-2. FBLN-3 overexpression significantly down-regulated the cellular level of c-MET and inhibited hepatocyte growth factor-induced c-MET activation, which were closely associated with γ-radiation resistance of cancer cells. Moreover, we also showed that c-MET suppression or inactivation decreased the cellular level of ALDH1 isozymes (ALDH1A1 or ALDH1A3), which serve as cancer stem cell markers, and subsequently induced inhibition of cell growth in pancreatic cancer cells. Therefore, forced overexpression of FBLN-3 sensitized cells to cytotoxic agents such as γ-radiation and strongly inhibited the stemness and epithelial to mesenchymal transition (EMT) property of pancreatic cancer cells. On the other hand, if FBLN3 was suppressed in FBLN-3-expressing BxPC3 cells, the results were opposite. This study provides the first demonstration that the FBLN-3/c-MET/ALDH1 axis in pancreatic cancer cells partially modulates stemness and EMT as well as sensitization of cells to the detrimental effects of γ-radiation

A protocadherin-cadherin-FLRT3 complex controls cell adhesion and morphogenesis.

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Xuejun Chen

2009-12-01

Full Text Available Paraxial protocadherin (PAPC and fibronectin leucine-rich domain transmembrane protein-3 (FLRT3 are induced by TGFbeta signaling in Xenopus embryos and both regulate morphogenesis by inhibiting C-cadherin mediated cell adhesion.We have investigated the functional and physical relationships between PAPC, FLRT3, and C-cadherin. Although neither PAPC nor FLRT3 are required for each other to regulate C-cadherin adhesion, they do interact functionally and physically, and they form a complex with cadherins. By itself PAPC reduces cell adhesion physiologically to induce cell sorting, while FLRT3 disrupts adhesion excessively to cause cell dissociation. However, when expressed together PAPC limits the cell dissociating and tissue disrupting activity of FLRT3 to make it effective in physiological cell sorting. PAPC counteracts FLRT3 function by inhibiting the recruitment of the GTPase RND1 to the FLRT3 cytoplasmic domain.PAPC and FLRT3 form a functional complex with cadherins and PAPC functions as a molecular "governor" to maintain FLRT3 activity at the optimal level for physiological regulation of C-cadherin adhesion, cell sorting, and morphogenesis.

Inhibition of protein kinase C induces differentiation in Neuro-2a cells

International Nuclear Information System (INIS)

Minana, M.D.; Felipo, V.; Grisolia, S.

1990-01-01

1-(5-Isoquinolinylsulfonyl)-2-methylpiperazine (H7), a potent inhibitor of protein kinase C, induced neuritogenesis in Neuro-2a cells, whereas N-(2-guanidinoethyl)-5-isoquinolinesulfonamide (HA 1004), which inhibits more efficiently cAMP- and cGMP-dependent protein kinases, did not. The effect, noticeable after 3 hr, was maximum (13-fold increase at 500 μM H7) between 1 and 3 days and was maintained over 2 months. In controls, 90% of the cells were undifferentiated, whereas after 3 hr with 500 μM H7 only 25% of the cells remained undifferentiated. DNA synthesis decreased as the number of differentiated cells increased. Differentiation is also functional since acetylcholinesterase activity increased ∼7-fold after 48 hr with 500 μM H7. Phorbol 12-myristate 13-acetate, a specific activator of protein kinase C, prevented or reversed the induction of neuritogenesis and the inhibition of DNA synthesis by H7. There is a good correlation between the level of protein kinase C and the percentage of differentiated cells. The results indicate that protein kinase C may play a key role in the control of differentiation of neural cells. Some possible clinical implications are briefly discussed

BENZO[A]PYRENE AND ITS K-REGION DIOL INDUCE DNA DAMAGE IN C3H10T1/2C18 CELLS AS MEASURED BY THE ALKALINE SINGLE CELL GEL (COMET) ASSAY

Science.gov (United States)

160. Benzo[a]pyrene and its K-region diol induce DNA damage in C3HlOTl/2Cl8 cells as measured by the alkaline single cell gel (Comet) assay In a continuing series of studies on the genotoxicity ofK-region dihydrodiols of polycyclic aromatic hydrocarbons, we have repo...

Cytokine and surface receptor diversity of NK cells in resistant C3H/HeN and susceptible BALB/c mice with chronic Pseudomonas aeruginosa lung infection

DEFF Research Database (Denmark)

Calum, Henrik; Moser, Claus; Jensen, Peter Østrup

2003-01-01

The purpose of the present study was to investigate whether NK cells from resistant C3H/HeN mice and susceptible BALB/c mice showed different release of cytokines and expression of surface molecules during chronic P. aeruginosa lung infection using alginate-embedded P. aeruginosa mimicking...... expression of the LFA-1 and Fc receptors on NK cells. At day 2, IFN-gamma levels increased in C3H/HeN mice but decreased in BALB/c mice. The GM-CSF levels increased only in the C3H/HeN mice at day 1 and 2. Surface expression of LFA-1 on the NK cells was higher in C3H/HeN mice at day 1 and 2. In contrast...

Atypical Plasmacytic Proliferation in a Case of C3 Glomerulopathy

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Osama Elfituri MD

2017-02-01

Full Text Available An 11-year-old Hispanic female underwent evaluation of asymptomatic proteinuria and hematuria. The patient denied fever, edema, and gross hematuria. Urinalysis showed mild proteinuria, and a urine microscopic examination revealed red blood cells. Screening tests for glomerulonephritis revealed a low C3 and negative ANA, ASO, DNAse-B, and ANCA. Histological examination of a renal biopsy specimen showed glomeruli with endocapillary proliferation, a predominant C3 deposition in the capillary loops by immunofluorescence, and electron dense deposits in the mesangium, paramesangium, and capillary walls by electron microscopy consistent with a diagnosis of C3 glomerulopathy. An interstitial plasmacytosis was also present with focal clustering of plasma cells, which were found to be kappa light chain restricted by in situ hybridization suggestive of a clonal proliferation. One can speculate that these plasma cells may be directly responsible for the renal pathology that was seen.

Cytokine and surface receptor diversity of NK cells in resistant C3H/HeN and susceptible BALB/c mice with chronic Pseudomonas aeruginosa lung infection

DEFF Research Database (Denmark)

Calum, Henrik; Moser, Claus; Jensen, Peter Østrup

2003-01-01

The purpose of the present study was to investigate whether NK cells from resistant C3H/HeN mice and susceptible BALB/c mice showed different release of cytokines and expression of surface molecules during chronic P. aeruginosa lung infection using alginate-embedded P. aeruginosa mimicking...... the infection in cystic fibrosis. Lung cell suspensions were depleted of lymphocytes by magnetic cell sorting. The concentrations of IFN-gamma, IL-1beta and GM-CSF were estimated by ELISA at day 1 and 2 after infection. Non-infected mice were used as controls. Flow cytometry was used to estimate the surface...... expression of the LFA-1 and Fc receptors on NK cells. At day 2, IFN-gamma levels increased in C3H/HeN mice but decreased in BALB/c mice. The GM-CSF levels increased only in the C3H/HeN mice at day 1 and 2. Surface expression of LFA-1 on the NK cells was higher in C3H/HeN mice at day 1 and 2. In contrast...

Ganoderma lucidum extracts inhibited leukemia WEHI-3 cells in BALB/c mice and promoted an immune response in vivo.

Science.gov (United States)

Chang, Yung-Hsien; Yang, Jai-Sing; Yang, Jiun-Long; Wu, Chang-Lin; Chang, Shu-Jen; Lu, Kung-Wen; Lin, Jen-Jyh; Hsia, Te-Chun; Lin, Yi-Ting; Ho, Chin-Chih; Wood, W Gibson; Chung, Jing-Gung

2009-12-01

Ganoderma lucidum (G. lucidum) is a medicinal mushroom having biological effects such as immunomodulation and anti-tumor actions. In China and many other Asian countries, G. lucidum is used as a folk remedy to promote health and longevity. Although many studies have shown that G. lucidum modulates the immune system, including, for example, antigen-presenting cells, natural killer (NK) cells, and the T and B lymphocytes, the effects of G. lucidum on the WEHI-3 leukemic BALB/c mice are unclear. We attempted to determine whether G. lucidum would promote immune responses in BALB/c mice injected with WEHI-3 leukemia cells. The effects of G. lucidum on the survival rate of WEHI-3 leukemia cells injected into BALB/c mice were examined. It increased the percentages of CD3 and CD19, but decreased the percentages of Mac-3 and CD11b markers, suggesting that differentiation of the precursor of T and B cells was promoted but macrophages were inhibited. It decreased the weight of spleens as compared with control mice. It also promoted phagocytosis by macrophage from peripheral blood mononuclear cell (PBMC) and it also promoted natural killer cell activity. It decreased the percentage of leukemia cells in the spleens of mice before they were injected with WEHI-3 cells. Apparently, G. lucidum affects murine leukemia WEHI-3 cells in vivo.

Generation of Anaphylatoxins by Human β-Tryptase from C3, C4, and C51

Science.gov (United States)

Fukuoka, Yoshihiro; Xia, Han-Zhang; Sanchez-Muñoz, Laura B.; Dellinger, Anthony L.; Escribano, Luis; Schwartz, Lawrence B.

2009-01-01

Both mast cells and complement participate in innate and acquired immunity. The current study examines whether β-tryptase, the major protease of human mast cells, can directly generate bioactive complement anaphylatoxins. Important variables included pH, monomeric vs tetrameric forms of β-tryptase, and the β-tryptase-activating polyanion. The B12 mAb was used to stabilize β-tryptase in its monomeric form. C3a and C4a were best generated from C3 and C4, respectively, by monomeric β-tryptase in the presence of low molecular weight dextran sulfate or heparin at acidic pH. High molecular weight polyanions increased degradation of these anaphylatoxins. C5a was optimally generated from C5 at acidic pH by β-tryptase monomers in the presence of high molecular weight dextran sulfate and heparin polyanions, but also was produced by β-tryptase tetramers under these conditions. Mass spectrometry verified that the molecular mass of each anaphylatoxin was correct. Both β-tryptase-generated C5a and C3a (but not C4a) were potent activators of human skin mast cells. These complement anaphylatoxins also could be generated by β-tryptase in releasates of activated skin mast cells. Of further biologic interest, β-tryptase also generated C3a from C3 in human plasma at acidic pH. These results suggest β-tryptase might generate complement anaphylatoxins in vivo at sites of inflammation, such as the airway of active asthma patients where the pH is acidic and where elevated levels of β-tryptase and complement anaphylatoxins are detected. PMID:18424754

Vitamin K3 and vitamin C alone or in combination induced apoptosis in leukemia cells by a similar oxidative stress signalling mechanism.

Science.gov (United States)

Bonilla-Porras, Angelica R; Jimenez-Del-Rio, Marlene; Velez-Pardo, Carlos

2011-06-10

Secondary therapy-related acute lymphoblastic leukemia might emerge following chemotherapy and/or radiotherapy for primary malignancies. Therefore, other alternatives should be pursued to treat leukemia. It is shown that vitamin K3- or vitamin C- induced apoptosis in leukemia cells by oxidative stress mechanism involving superoxide anion radical and hydrogen peroxide generation, activation of NF-κB, p53, c-Jun, protease caspase-3 activation and mitochondria depolarization leading to nuclei fragmentation. Cell death was more prominent when Jurkat and K562 cells are exposed to VC and VK3 in a ratio 1000:1 (10 mM: 10 μM) or 100:1 (300 μM: 3 μM), respectively. We provide for the first time in vitro evidence supporting a causative role for oxidative stress in VK3- and VC-induced apoptosis in Jurkat and K562 cells in a domino-like mechanism. Altogether these data suggest that VK3 and VC should be useful in the treatment of leukemia.

BMP-7 enhances cell migration and αvβ3 integrin expression via a c-Src-dependent pathway in human chondrosarcoma cells.

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Jui-Chieh Chen

Full Text Available Bone morphogenic protein (BMP-7 is a member of the transforming growth factor (TGF-beta superfamily, which is originally identified based on its ability to induce cartilage and bone formation. In recent years, BMP-7 is also defined as a potent promoter of cell motility, invasion, and metastasis. However, there is little knowledge of the role of BMP-7 and its cellular function in chondrosarcoma cells. In the present study, we investigated the biological impact of BMP-7 on cell motility using transwell assay. In addition, the intracellular signaling pathways were also investigated by pharmacological and genetic approaches. Our results demonstrated that treatment with exogenous BMP-7 markedly increased cell migration by activating c-Src/PI3K/Akt/IKK/NF-κB signaling pathway, resulting in the transactivation of αvβ3 integrin expression. Indeed, abrogation of signaling activation, by chemical inhibition or expression of a kinase dead form of the protein attenuated BMP-7-induced expression of integrin αvβ3 and cell migration. These findings may provide a useful tool for diagnostic/prognostic purposes and even therapeutically in late-stage chondrosarcoma as an anti-metastatic agent.

CH3NH3I treatment temperature of 70 °C in low-pressure vapor-assisted deposition for mesoscopic perovskite solar cells

Science.gov (United States)

Jin, Wenbin; Zou, Xiaoping; Bai, Xiao; Yang, Ying; Chen, Dan

2018-01-01

Herein, we report a modified vapor-assisted deposition method to fabricate CH3NH3PbI3 film at 70 °C in a vacuum drying oven. The modified method has excellent operability and expandability in preparing perovskite solar cells. The CH3NH3I treatment temperature is 130 °C or 150 °C in conventional method, but we reduced the temperature to 70 °C in the modified vapor-assisted method. Meanwhile, the quality of CH3NH3PbI3 films prepared via the modified method is superior to that of CH3NH3PbI3 films of solution-processed method.

Plasmids encoding PKI(1-31), a specific inhibitor of cAMP-stimulated gene expression, inhibit the basal transcriptional activity of some but not all cAMP-regulated DNA response elements in JEG-3 cells.

Science.gov (United States)

Grove, J R; Deutsch, P J; Price, D J; Habener, J F; Avruch, J

1989-11-25

Plasmids that encode a bioactive amino-terminal fragment of the heat-stable inhibitor of the cAMP-dependent protein kinase, PKI(1-31), were employed to characterize the role of this protein kinase in the control of transcriptional activity mediated by three DNA regulatory elements in the JEG-3 human placental cell line. The 5'-flanking sequence of the human collagenase gene contains the heptameric sequence, 5'-TGAGTCA-3', previously identified as a "phorbol ester" response element. Reporter genes containing either the intact 1.2-kilobase 5'-flanking sequence from the human collagenase gene or just the 7-base pair (bp) response element, when coupled to an enhancerless promoter, each exhibit both cAMP and phorbol ester-stimulated expression in JEG-3 cells. Cotransfection of either construct with plasmids encoding PKI(1-31) inhibits cAMP-stimulated but not basal- or phorbol ester-stimulated expression. Pretreatment of cells with phorbol ester for 1 or 2 days abrogates completely the response to rechallenge with phorbol ester but does not alter the basal expression of either construct; cAMP-stimulated expression, while modestly inhibited, remains vigorous. The 5'-flanking sequence of the human chorionic gonadotropin-alpha subunit (HCG alpha) gene has two copies of the sequence, 5'-TGACGTCA-3', contained in directly adjacent identical 18-bp segments, previously identified as a cAMP-response element. Reporter genes containing either the intact 1.5 kilobase of 5'-flanking sequence from the HCG alpha gene, or just the 36-bp tandem repeat cAMP response element, when coupled to an enhancerless promoter, both exhibit a vigorous cAMP stimulation of expression but no response to phorbol ester in JEG-3 cells. Cotransfection with plasmids encoding PKI(1-31) inhibits both basal and cAMP-stimulated expression in a parallel fashion. The 5'-flanking sequence of the human enkephalin gene mediates cAMP-stimulated expression of reporter genes in both JEG-3 and CV-1 cells. Plasmids

Radiation-induced transformation in oncogene primed C3H/10T1/2 cells; a new system for analysis of multi-step transformation in vitro

International Nuclear Information System (INIS)

Drozdoff, V.V.

1988-01-01

Several established rodent cell lines, such as C3H/10T1/2 fibroblasts, have been developed to study radiation and chemically-induced malignant transformation. Most experimental evidence has supported the idea that transformation in 10T1/2 cells involved at least two steps but that the apparent frequency of transformation depends on the density of plated cells. A new approach is presented here for studying radiation-induced transformation. An oncogene primed cell system (C3H-myc) was developed by introducing a constitutively active mouse c-myc gene into 10T1/2 cells. A primary goal was to determine if the introduction of an activated oncogene could substitute for one of the required steps in radiation-induced transformation. Results are presented that show that the expression of the exogenous myc gene significantly increased the frequency of radiation-induced transformation in these cells. Subculture experiments performed to analyze the kinetics of transformation in C3H-myc cells and reconstruction experiments allowing the effects of normal cells on radiation-induced transformants to be determined indicated that transformed cells arose very shortly after irradiation. These results support the conclusion that a radiation-induced event can complement the effect of myc in C3H-myc cells and directly result in transformation. This system thus provides an opportunity to isolate early steps in radiation-induced transformation and should facilitate the identification and analysis of these events

Leptin rapidly activates PPARs in C2C12 muscle cells

International Nuclear Information System (INIS)

Bendinelli, Paola; Piccoletti, Roberta; Maroni, Paola

2005-01-01

Experimental evidence suggests that leptin operates on the tissues, including skeletal muscle, also by modulating gene expression. Using electrophoretic mobility shift assays, we have shown that physiological doses of leptin promptly increase the binding of C2C12 cell nuclear extracts to peroxisome proliferator-activated receptor (PPAR) response elements in oligonucleotide probes and that all three PPAR isoforms participate in DNA-binding complexes. We pre-treated C2C12 cells with AACOCF 3 , a specific inhibitor of cytosolic phospholipase A 2 (cPLA 2 ), an enzyme that supplies ligands to PPARs, and found that it abrogates leptin-induced PPAR DNA-binding activity. Leptin treatment significantly increased cPLA 2 activity, evaluated as the release of [ 3 H]arachidonic acid from pre-labelled C2C12 cells, as well as phosphorylation. Further, using MEK1 inhibitor PD-98059 we showed that leptin activates cPLA 2 through ERK induction. These results support a direct effect of leptin on skeletal muscle cells, and suggest that the hormone may modulate muscle transcription also by precocious activation of PPARs through ERK-cPLA 2 pathway

A recombinant fusion toxin based on enzymatic inactive C3bot1 selectively targets macrophages.

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Lydia Dmochewitz

Full Text Available BACKGROUND: The C3bot1 protein (~23 kDa from Clostridium botulinum ADP-ribosylates and thereby inactivates Rho. C3bot1 is selectively taken up into the cytosol of monocytes/macrophages but not of other cell types such as epithelial cells or fibroblasts. Most likely, the internalization occurs by a specific endocytotic pathway via acidified endosomes. METHODOLOGY/PRINCIPAL FINDINGS: Here, we tested whether enzymatic inactive C3bot1E174Q serves as a macrophage-selective transport system for delivery of enzymatic active proteins into the cytosol of such cells. Having confirmed that C3bot1E174Q does not induce macrophage activation, we used the actin ADP-ribosylating C2I (∼50 kDa from Clostridium botulinum as a reporter enzyme for C3bot1E174Q-mediated delivery into macrophages. The recombinant C3bot1E174Q-C2I fusion toxin was cloned and expressed as GST-protein in Escherichia coli. Purified C3bot1E174Q-C2I was recognized by antibodies against C2I and C3bot and showed C2I-specific enzyme activity in vitro. When applied to cultured cells C3bot1E174Q-C2I ADP-ribosylated actin in the cytosol of macrophages including J774A.1 and RAW264.7 cell lines as well as primary cultured human macrophages but not of epithelial cells. Together with confocal fluorescence microscopy experiments, the biochemical data indicate the selective uptake of a recombinant C3-fusion toxin into the cytosol of macrophages. CONCLUSIONS/SIGNIFICANCE: In summary, we demonstrated that C3bot1E174Q can be used as a delivery system for fast, selective and specific transport of enzymes into the cytosol of living macrophages. Therefore, C3-based fusion toxins can represent valuable molecular tools in experimental macrophage pharmacology and cell biology as well as attractive candidates to develop new therapeutic approaches against macrophage-associated diseases.

Suppression of transformed foci, induced by alpha radiation of C3H 10T1/2 cells, by untransformed cells

International Nuclear Information System (INIS)

Lloyd, E.L.; Gemmell, M.A.; Henning, C.B.

1978-01-01

The C3H 10T1/2 CL8 cell line obtained from a mouse embryo has been widely used for screening chemical carcinogens. Transformed foci are easily distinguishable in this system as crisscrossed, piled-up cells which stain more deeply than the surrounding untransformed cells. When these foci are ringcloned and subcultured, they have been shown to give rise to malignant tumors in C3H immunodepressed mice. Previous work showed that such malignant transformations, which occurred with a dose dependent frequency, could be induced by alpha particle irradiation. The present study, in turn, demonstrates that the expression of these transformations can be completely suppressed by co-cultivating the transformed cells with a large number of untransformed cells. The precise ratio of the number of untransformed cells to transformed cells to give complete suppression was found to vary in different experiments. Maximum effects were seen when a small number of transformed cells in low passage were used. These experiments may provide at least a partial explanation for the greatly increased frequency of transformations per cell irradiated in vitro, compared with the number of tumors observed after irradiation of the same number of cells in vivo. In addition, if conditions could be optimized whereby transformed foci could reproducibly be eliminated by the use of a known number of untransformed cells, this might have important applications in the prevention and treatment of certain human cancers

Benzodiazepines have high-affinity binding sites and induce melanogenesis in B16/C3 melanoma cells.

OpenAIRE

Matthew, E; Laskin, J D; Zimmerman, E A; Weinstein, I B; Hsu, K C; Engelhardt, D L

1981-01-01

We found that two markers of differentiation, tyrosinase (monophenol, dihydroxyphenylalanine:oxygen oxidoreductase, EC 1.14.18.1) activity and melanin synthesis, are induced by diazepam in B16/C3 mouse melanoma cells. We also demonstrated high-affinity binding sites for [3H]diazepam in these cells by radioreceptor assay, and we visualized binding to the cell surface by fluorescence microscopy with a benzodiazepine analog conjugated to a fluorescein-labeled protein. Our studies also showed tha...

Wnt/β-catenin signaling changes C2C12 myoblast proliferation and differentiation by inducing Id3 expression

International Nuclear Information System (INIS)

Zhang, Long; Shi, Songting; Zhang, Juan; Zhou, Fangfang; Dijke, Peter ten

2012-01-01

Highlights: ► Expression of Id3 but not Id1 is induced by Wnt3a stimulation in C2C12 cells. ► Wnt3a induces Id3 expression via canonical Wnt/β-catenin pathway. ► Wnt3a-induced Id3 expression does not depend on BMP signaling activation. ► Induction of Id3 expression is critical determinant in Wnt3a-induced cell proliferation and differentiation. -- Abstract: Canonical Wnt signaling plays important roles in regulating cell proliferation and differentiation. In this study, we report that inhibitor of differentiation (Id)3 is a Wnt-inducible gene in mouse C2C12 myoblasts. Wnt3a induced Id3 expression in a β-catenin-dependent manner. Bone morphogenetic protein (BMP) also potently induced Id3 expression. However, Wnt-induced Id3 expression occurred independent of the BMP/Smad pathway. Functional studies showed that Id3 depletion in C2C12 cells impaired Wnt3a-induced cell proliferation and alkaline phosphatase activity, an early marker of osteoblast cells. Id3 depletion elevated myogenin induction during myogenic differentiation and partially impaired Wnt3a suppressed myogenin expression in C2C12 cells. These results suggest that Id3 is an important Wnt/β-catenin induced gene in myoblast cell fate determination.

Vitamin K3 and vitamin C alone or in combination induced apoptosis in leukemia cells by a similar oxidative stress signalling mechanism

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Velez-Pardo Carlos

2011-06-01

Full Text Available Abstract Background Secondary therapy-related acute lymphoblastic leukemia might emerge following chemotherapy and/or radiotherapy for primary malignancies. Therefore, other alternatives should be pursued to treat leukemia. Results It is shown that vitamin K3- or vitamin C- induced apoptosis in leukemia cells by oxidative stress mechanism involving superoxide anion radical and hydrogen peroxide generation, activation of NF-κB, p53, c-Jun, protease caspase-3 activation and mitochondria depolarization leading to nuclei fragmentation. Cell death was more prominent when Jurkat and K562 cells are exposed to VC and VK3 in a ratio 1000:1 (10 mM: 10 μM or 100:1 (300 μM: 3 μM, respectively. Conclusion We provide for the first time in vitro evidence supporting a causative role for oxidative stress in VK3- and VC-induced apoptosis in Jurkat and K562 cells in a domino-like mechanism. Altogether these data suggest that VK3 and VC should be useful in the treatment of leukemia.

Single-cell Hi-C bridges microscopy and genome-wide sequencing approaches to study 3D chromatin organization.

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Ulianov, Sergey V; Tachibana-Konwalski, Kikue; Razin, Sergey V

2017-10-01

Recent years have witnessed an explosion of the single-cell biochemical toolbox including chromosome conformation capture (3C)-based methods that provide novel insights into chromatin spatial organization in individual cells. The observations made with these techniques revealed that topologically associating domains emerge from cell population averages and do not exist as static structures in individual cells. Stochastic nature of the genome folding is likely to be biologically relevant and may reflect the ability of chromatin fibers to adopt a number of alternative configurations, some of which could be transiently stabilized and serve regulatory purposes. Single-cell Hi-C approaches provide an opportunity to analyze chromatin folding in rare cell types such as stem cells, tumor progenitors, oocytes, and totipotent cells, contributing to a deeper understanding of basic mechanisms in development and disease. Here, we review key findings of single-cell Hi-C and discuss possible biological reasons and consequences of the inferred dynamic chromatin spatial organization. © 2017 WILEY Periodicals, Inc.

Coculture with BJ fibroblast cells inhibits the adipogenesis and lipogenesis in 3T3-L1 cells

International Nuclear Information System (INIS)

Jeong, Hyun Jeong; Park, Sahng Wook; Kim, Hojeong; Park, Sang-Kyu; Yoon, Dojun

2010-01-01

Mouse or human fibroblasts are commonly used as feeder cells to prevent differentiation in stem or primary cell culture. In the present study, we addressed whether fibroblasts can affect the differentiation of adipocytes. We found that the differentiation of 3T3-L1 preadipocytes was strongly suppressed when the cells were cocultured with human fibroblast (BJ) cells. BrdU incorporation analysis indicated that mitotic clonal expansion, an early event required for 3T3-L1 cell adipogenesis, was not affected by BJ cells. The 3T3-L1 cell expression levels of peroxisome proliferator-activated receptor γ2, CCAAT/enhancer-binding protein alpha (C/EBPα), sterol regulatory element binding protein-1c, and Krueppel-like factor 15, but not those of C/EBPβ or C/EBPδ, were decreased by coculture with BJ cells. When mature 3T3-L1 adipocytes were cocultured with BJ cells, their lipid contents were significantly reduced, with decreased fatty acid synthase expression and increased phosphorylated form of acetyl-CoA carboxylase 1. Our data indicate that coculture with BJ fibroblast cells inhibits the adipogenesis of 3T3-L1 preadipocytes and decreases the lipogenesis of mature 3T3-L1 adipocytes.

Synergy between type 1 fimbriae expression and C3 opsonisation increases internalisation of E. coli by human tubular epithelial cells.

Science.gov (United States)

Li, Ke; Zhou, Wuding; Hong, Yuzhi; Sacks, Steven H; Sheerin, Neil S

2009-03-31

Bacterial infection of the urinary tract is a common clinical problem with E. coli being the most common urinary pathogen. Bacterial uptake into epithelial cells is increasingly recognised as an important feature of infection. Bacterial virulence factors, especially fimbrial adhesins, have been conclusively shown to promote host cell invasion. Our recent study reported that C3 opsonisation markedly increases the ability of E. coli strain J96 to internalise into human proximal tubular epithelial cells via CD46, a complement regulatory protein expressed on host cell membrane. In this study, we further assessed whether C3-dependent internalisation by human tubular epithelial cells is a general feature of uropathogenic E. coli and investigated features of the bacterial phenotype that may account for any heterogeneity. In 31 clinical isolates of E. coli tested, C3-dependent internalisation was evident in 10 isolates. Type 1 fimbriae mediated-binding is essential for C3-dependent internalisation as shown by phenotypic association, type 1 fimbrial blockade with soluble ligand (mannose) and by assessment of a type 1 fimbrial mutant. we propose that efficient internalisation of uropathogenic E. coli by the human urinary tract depends on co-operation between type 1 fimbriae-mediated adhesion and C3 receptor -ligand interaction.

Cell Death in C. elegans Development.

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Malin, Jennifer Zuckerman; Shaham, Shai

2015-01-01

Cell death is a common and important feature of animal development, and cell death defects underlie many human disease states. The nematode Caenorhabditis elegans has proven fertile ground for uncovering molecular and cellular processes controlling programmed cell death. A core pathway consisting of the conserved proteins EGL-1/BH3-only, CED-9/BCL2, CED-4/APAF1, and CED-3/caspase promotes most cell death in the nematode, and a conserved set of proteins ensures the engulfment and degradation of dying cells. Multiple regulatory pathways control cell death onset in C. elegans, and many reveal similarities with tumor formation pathways in mammals, supporting the idea that cell death plays key roles in malignant progression. Nonetheless, a number of observations suggest that our understanding of developmental cell death in C. elegans is incomplete. The interaction between dying and engulfing cells seems to be more complex than originally appreciated, and it appears that key aspects of cell death initiation are not fully understood. It has also become apparent that the conserved apoptotic pathway is dispensable for the demise of the C. elegans linker cell, leading to the discovery of a previously unexplored gene program promoting cell death. Here, we review studies that formed the foundation of cell death research in C. elegans and describe new observations that expand, and in some cases remodel, this edifice. We raise the possibility that, in some cells, more than one death program may be needed to ensure cell death fidelity. © 2015 Elsevier Inc. All rights reserved.

Interaction between Galectin-9/TIM-3 pathway and follicular helper CD4+ T cells contributes to viral persistence in chronic hepatitis C.

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Zhuo, Ya; Zhang, Yi-Fu; Wu, Hong-Jie; Qin, Lei; Wang, Yan-Ping; Liu, A-Min; Wang, Xin-Hong

2017-10-01

Both Galectin 9 (Gal-9)/T-cell immunoglobulin and mucin domain-containing protein 3 (TIM-3) pathway and follicular helper CD4 + T (Tfh) cells play important roles in persistent hepatitis C virus (HCV) infection. Thus, we aimed to investigate the regulatory role of interaction between Gal-9/TIM-3 pathway and Tfh cells in chronic hepatitis C. A total of 44 chronic hepatitis C patients and 19 normal controls (NCs) were enrolled in this study. Purified CD4 + T cells were cultured by TIM-3 Fc protein, recombinant Gal-9, or IL-21 for 48h. TIM-3 expression, Tfh proportion, and IL-21 production was measured, respectively. The immunomodulatory role of Gal-9/TIM-3 and IL-21 was also investigated in HCV cell culture system in vitro. We found that the percentage corresponding to both TIM-3-positive and CXCR5 + ICOS + Tfh cells within CD4 + T cells, which correlated with HCV RNA replication, was significantly elevated in patients with chronic hepatitis C in comparison with those in NCs. Moreover, blockade of Gal-9/TIM-3 pathway by TIM-3 Fc protein increased Tfh cells proportion, IL-21 mRNA and protein expression within purified CD4 + T cells, while activation of Gal-9/TIM-3 signaling by Gal-9 stimulation decreased IL-21 production in both patients with chronic HCV infection and healthy individuals. Meanwhile, high concentrations (100 and 200ng/mL) of IL-21 stimulation also elevated TIM-3 expression on CD4 + T cells in chronic hepatitis C. Furthermore, TIM-3 blockage and IL-21 stimulation suppressed mRNA expressions of HCV-induced antiviral proteins (myxovirus resistance A and oligoadenylate synthetase) in Huh7.5 cells without affecting viral replication in HCV cell culture system. The interaction between Gal-9/TIM-3 pathway and Tfh cells contributed to viral persistent in chronic HCV infection, which might be pivotal for development of new therapeutic approaches for chronic hepatitis C. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

The comparison of grey-scale ultrasonic and clinical features of hepatoblastoma and hepatocellular carcinoma in children: a retrospective study for ten years

Directory of Open Access Journals (Sweden)

Luo Yan

2011-06-01

Full Text Available Abstract Background Hepatoblastoma (HBL and hepatocellular carcinoma (HCC are respectively the first and the second most common pediatric malignant liver tumors. The purpose of this study was to evaluate the combined use of the ultrasound examination and the assessment of the patients' clinical features for differentiating HBL from HCC in children. Methods Thirty cases of the confirmed HBL and 12 cases of the confirmed HCC in children under the age of 15 years were enrolled into our study. They were divided into the HBL group and the HCC group according to the histological types of the tumors. The ultrasonic features and the clinical manifestations of the two groups were retrospectively analyzed, with an emphasis on the following parameters: onset age, gender (male/female ratio, positive epatitis-B-surface-antigen (HBV, alpha-fetoprotein increase, and echo features including septa, calcification and liquefaction within the tumors. Results Compared with the children with HCC, the children with HBL had a significantly younger onset age (8.2 years vs. 3.9 years, P Conclusion Ultrasonic features combined with clinical manifestations are valuable for differentiating HBL from HCC in children.

Hsa-let-7a functions as a tumor suppressor in renal cell carcinoma cell lines by targeting c-myc

Energy Technology Data Exchange (ETDEWEB)

Liu, Yongchao; Yin, Bingde; Zhang, Changcun; Zhou, Libin [Department of Urology, Shanghai First People' s Hospital, School of Medicine, Shanghai Jiaotong University, Shanghai 200080 (China); Fan, Jie, E-mail: jief67@sina.com [Department of Urology, Shanghai First People' s Hospital, School of Medicine, Shanghai Jiaotong University, Shanghai 200080 (China)

2012-01-06

Highlights: Black-Right-Pointing-Pointer This study is the first to test the let-7a/c-myc loop in renal cell carcinoma cell lines. Black-Right-Pointing-Pointer Let-7a down-regulated c-myc in three renal cell carcinoma cell lines. Black-Right-Pointing-Pointer c-myc target genes were down-regulated because of the let-7a-mediated down-regulation of c-myc. Black-Right-Pointing-Pointer The let-7a/c-myc loop has a significant function in renal cell carcinoma cell lines. -- Abstract: Widespread functions of the c-myc pathway play a crucial role in renal cell carcinoma (RCC) carcinogenesis. Thus, we evaluated the connection between proto-oncogenic c-myc and anti-neoplastic hsa-let-7a (let-7a) in RCC cell lines. The levels of c-myc and let-7a in 3 RCC cell lines (769P, Caki-1 and 786O) were measured after transfecting the cells with let-7a mimics or a negative control. The change in c-myc protein level was confirmed by Western blot. The anti-neoplastic function of let-7a was evaluated using cell counting kit-8 (CCK-8) for proliferation analysis and cell flow cytometry for cell cycle analysis. The changes of downstream targets of c-myc were measured using reverse transcription quantitative real-time PCR (qRT-PCR). Our results suggest for the first time that let-7a acts as a tumor suppressor in RCC cell lines by down-regulating c-myc and c-myc target genes such as proliferating cell nuclear antigen (PCNA), cyclin D1 (CCND1) and the miR17-92 cluster, which is accompanied by proliferation inhibition and cell cycle arrest.

Fe3C-based oxygen reduction catalysts: synthesis, hollow spherical structures and applications in fuel cells

DEFF Research Database (Denmark)

Hu, Yang; Jensen, Jens Oluf; Zhang, Wei

2015-01-01

We present a detailed study of a novel Fe3C-based spherical catalyst with respect to synthetic parameters, nanostructure formation, ORR active sites and fuel cell demonstration. The catalyst is synthesized by high temperature autoclave pyrolysis using decomposing precursors. Below 500 °C, melamine...

PDGF stimulation of Mueller cell proliferation: Contributions of c-JNK and the PI3K/Akt pathway

International Nuclear Information System (INIS)

Moon, Sang Woong; Chung, Eun Jee; Jung, Sun-Ah; Lee, Joon H.

2009-01-01

Platelet-derived growth factor (PDGF) has a critical role in proliferative vitreoretinopathy (PVR) as a chemoattractant and mitogen for retinal pigment epithelial cells and retinal glial cells. Here, we investigated the potential effects of PDGF on the proliferation of Mueller cells and the intracellular signaling pathway mediating these changes. PDGF induced Mueller cell proliferation and increased phosphorylation of the PDGF receptor (PDGFR), as shown by an MTT assay and immunoprecipitation analyses. Both effects were blocked by JNJ, a PDGFR-selective tyrosine kinase inhibitor. PDGF also stimulated phosphorylation of c-JNK and Akt. PDGF-induced Mueller cell proliferation was significantly reduced by pre-treatment with SP600125 and LY294002, inhibitors of c-JNK and Akt phosphorylation, respectively. Our findings collectively indicate that PDGF-stimulated Mueller cell proliferation occurs via activation of the c-JNK and PI3K/Akt signaling pathways. These data provide useful information in establishing the role of Mueller cells in the development of proliferative vitreoretinopathy.

Nm23-M2/NDP kinase B induces endogenous c-myc and nm23-M1/NDP kinase A overexpression in BAF3 cells. Both NDP kinases protect the cells from oxidative stress-induced death

International Nuclear Information System (INIS)

Arnaud-Dabernat, Sandrine; Masse, Karine; Smani, Moneim; Peuchant, Evelyne; Landry, Marc; Bourbon, Pierre-Marie; Le Floch, Renaud; Daniel, Jean-Yves; Larou, Monique

2004-01-01

The nm23 gene family encodes nucleoside diphosphate kinases (NDPKs) which supply the cell with (d)NTPs. The human NDPKB, also known as the PuF protein, binds the c-myc promoter and transactivates the c-myc protooncogene. We have now studied the effects of mouse NDPKA and NDPKB overexpression on endogenous c-myc transactivation in the mouse BAF3 and the rat PC12 cell lines. c-myc transcripts were found to be up-regulated by NDPKB only in the BAF3 line. This suggests that c-myc transcriptional control via NDPKB depends on the presence of cell-specific co-factors. Unexpectedly, NDPKB also induced NDPKA expression. This new effect was found in both cell lines, suggesting that NDPKB-dependent nm23-M1 gene transactivation requires cis and/or trans elements different from those involved in c-myc transactivation. Moreover, the BAF3 cell proliferation capacities were found to be independent of NDPKA or B cell contents. Interestingly, cell death induced by c-myc overexpression or H 2 O 2 exposure was decreased in nm23-transfected compared to control BAF3 cells. These data collectively suggest that NDPKs might improve cell survival by a mechanism coupling DNA repair and transcriptional regulation of genes involved in DNA damage response

3-O-sulfated heparan sulfate recognized by the antibody HS4C3 contributes [corrected] to the differentiation of mouse embryonic stem cells via fas signaling.

Directory of Open Access Journals (Sweden)

Kazumi Hirano

Full Text Available Maintenance of self-renewal and pluripotency in mouse embryonic stem cells (mESCs is regulated by the balance between several extrinsic signaling pathways. Recently, we demonstrated that heparan sulfate (HS chains play important roles in the maintenance and differentiation of mESCs by regulating extrinsic signaling. Sulfated HS structures are modified by various sulfotransferases during development. However, the significance of specific HS structures during development remains unclear. Here, we show that 3-O-sulfated HS structures synthesized by HS 3-O-sulfotransferases (3OSTs and recognized by the antibody HS4C3 increase during differentiation of mESCs. Furthermore, expression of Fas on the cell surface of the differentiated cells also increased. Overexpression of the HS4C3-binding epitope in mESCs induced apoptosis and spontaneous differentiation even in the presence of LIF and serum. These data showed that the HS4C3-binding epitope was required for differentiation of mESCs. Up-regulation of the HS4C3-binding epitope resulted in the recruitment of Fas from the cytoplasm to lipid rafts on the cell surface followed by activation of Fas signaling. Indeed, the HS4C3-binding epitope interacted with a region that included the heparin-binding domain (KLRRRVH of Fas. Reduced self-renewal capability in cells overexpressing 3OST resulted from the degradation of Nanog by activated caspase-3, which is downstream of Fas signaling, and was rescued by the inhibition of Fas signaling. We also found that knockdown of 3OST and inhibition of Fas signaling reduced the potential for differentiation into the three germ layers during embryoid body formation. This is the first demonstration that activation of Fas signaling is mediated by an increase in the HS4C3-binding epitope and indicates a novel signaling pathway for differentiation in mESCs.

3-O-sulfated heparan sulfate recognized by the antibody HS4C3 contributes [corrected] to the differentiation of mouse embryonic stem cells via fas signaling.

Science.gov (United States)

Hirano, Kazumi; Sasaki, Norihiko; Ichimiya, Tomomi; Miura, Taichi; Van Kuppevelt, Toin H; Nishihara, Shoko

2012-01-01

Maintenance of self-renewal and pluripotency in mouse embryonic stem cells (mESCs) is regulated by the balance between several extrinsic signaling pathways. Recently, we demonstrated that heparan sulfate (HS) chains play important roles in the maintenance and differentiation of mESCs by regulating extrinsic signaling. Sulfated HS structures are modified by various sulfotransferases during development. However, the significance of specific HS structures during development remains unclear. Here, we show that 3-O-sulfated HS structures synthesized by HS 3-O-sulfotransferases (3OSTs) and recognized by the antibody HS4C3 increase during differentiation of mESCs. Furthermore, expression of Fas on the cell surface of the differentiated cells also increased. Overexpression of the HS4C3-binding epitope in mESCs induced apoptosis and spontaneous differentiation even in the presence of LIF and serum. These data showed that the HS4C3-binding epitope was required for differentiation of mESCs. Up-regulation of the HS4C3-binding epitope resulted in the recruitment of Fas from the cytoplasm to lipid rafts on the cell surface followed by activation of Fas signaling. Indeed, the HS4C3-binding epitope interacted with a region that included the heparin-binding domain (KLRRRVH) of Fas. Reduced self-renewal capability in cells overexpressing 3OST resulted from the degradation of Nanog by activated caspase-3, which is downstream of Fas signaling, and was rescued by the inhibition of Fas signaling. We also found that knockdown of 3OST and inhibition of Fas signaling reduced the potential for differentiation into the three germ layers during embryoid body formation. This is the first demonstration that activation of Fas signaling is mediated by an increase in the HS4C3-binding epitope and indicates a novel signaling pathway for differentiation in mESCs.

Sim3C: simulation of Hi-C and Meta3C proximity ligation sequencing technologies.

Science.gov (United States)

DeMaere, Matthew Z; Darling, Aaron E

2018-02-01

Chromosome conformation capture (3C) and Hi-C DNA sequencing methods have rapidly advanced our understanding of the spatial organization of genomes and metagenomes. Many variants of these protocols have been developed, each with their own strengths. Currently there is no systematic means for simulating sequence data from this family of sequencing protocols, potentially hindering the advancement of algorithms to exploit this new datatype. We describe a computational simulator that, given simple parameters and reference genome sequences, will simulate Hi-C sequencing on those sequences. The simulator models the basic spatial structure in genomes that is commonly observed in Hi-C and 3C datasets, including the distance-decay relationship in proximity ligation, differences in the frequency of interaction within and across chromosomes, and the structure imposed by cells. A means to model the 3D structure of randomly generated topologically associating domains is provided. The simulator considers several sources of error common to 3C and Hi-C library preparation and sequencing methods, including spurious proximity ligation events and sequencing error. We have introduced the first comprehensive simulator for 3C and Hi-C sequencing protocols. We expect the simulator to have use in testing of Hi-C data analysis algorithms, as well as more general value for experimental design, where questions such as the required depth of sequencing, enzyme choice, and other decisions can be made in advance in order to ensure adequate statistical power with respect to experimental hypothesis testing.

Regulation of C/EBPβ isoforms by MAPK pathways in HL60 cells induced to differentiate by 1,25-dihydroxyvitamin D3

International Nuclear Information System (INIS)

Marcinkowska, Ewa; Garay, Edward; Gocek, Elzbieta; Chrobak, Agnieszka; Wang, Xuening; Studzinski, George P.

2006-01-01

C/EBPβ is known to be important for monocytic differentiation and macrophage function. Here, we found that expression of all three C/EBPβ isoforms induced in HL60 cells by 1,25-dihydroxyvitamin D 3 (1,25D) was upregulated in a sustained manner that correlates with the appearance of monocytic phenotype and with the G1 phase cell cycle arrest. In 1,25D-resistant HL60-40AF cells, isoforms β-1 and β-3 were expressed at levels comparable to 1,25D-sensitive HL60-G cells, but isoform β-2 was difficult to detect. Treatment of sensitive HL60 cells with 1,25D resulted in predominantly nuclear localization of C/EBP isoforms β-2 and β-3, while a large proportion of C/EBPβ-1 remained in the cytoplasm. Attenuation of the MEK-ERK MAPK pathway by the inhibitor PD98059 markedly reduced the expression, 1,25D-induced phosphorylation and nuclear localization of C/EBPβ-2 and C/EBPβ-3. Interestingly, only the lower molecular mass isoforms of C/EBPβ phosphorylated on Thr235 were found in the nuclei, while C/EBPβ-1 was constitutively phosphorylated and was detected principally in the cytoplasmic fraction. Although the role of C/EBPβ isoforms in 1,25D-induced differentiation is complex, our results taken together strongly suggest that the phosphorylation of C/EBPβ isoforms on Thr235 takes place mainly via the MEK-ERK pathway and that C/EBPβ-2 is the principal transcription factor in this cell system

Cadmium-109 uptake by tumors derived from Balb C/3T3 cell lines with varying degrees of the transformed phenotype

International Nuclear Information System (INIS)

Morton, K.; Alazraki, N.; Winge, D.; Lynch, R.E.

1986-01-01

To determine if tumors are rich in metallothionein, the authors measured the vivo uptake of subcutaneously-injected carrier-free cadmium-109 in tumors and in normal tissues of Balb/C mice. The tumors were grown in the mice from cultured Balb/3T3 cells transformed by the Moloney murine sarcoma virus. Uptake of cadmium-109 per gram of tissue was greatest for liver, kidney, and spleen. However, tumor uptake of cadmium-109 was markedly greater than that in blood, skeletal muscle, bones, intestine or adipose tissue. B Sephadex G-75 chromatography, the radioactivity in tumor and in liver lysates eluted with cytochrome-C, a molecule similar in molecular weight to metal-lothionein. To determine if metallothionein levels are related to the degree of malignancy of tumors, cadmium-109 uptake in the tumors from the virally-transformed cells was compared to that in tumors from non-transformed Balb/3T3 cells and two derivative chemically transformed cell lines. There was strong correlation between the substrate-independent growth in soft agarose of the four cell lines, the rate of growth of the corresponding tumors, and the amount of cadmium-109 uptake in the tumors. The authors conclude that metallothionein levels may be elevated in tumors as a function of the degree of expression of the transformed phenotype

Doping and stability of 3C-SiC: from thinfilm to bulk growth

DEFF Research Database (Denmark)

Jokubavicius, V.; Sun, J.; Linnarsson, M. K.

cell technology. Nitrogen and boron doped 3C-SiC layers can depict a new infrared LED. Hexagonal SiC is an excellent substrate for heteropeitaxial growth of 3C-SiC due to excellent compatibility in lattice constant and thermal expansion coefficient. However, the growth of 3C-SiC on such substrates......-SiC for optoelectronic applications are discussed....

Proteasome-mediated degradation of cell division cycle 25C and cyclin-dependent kinase 1 in phenethyl isothiocyanate-induced G2-M-phase cell cycle arrest in PC-3 human prostate cancer cells.

Science.gov (United States)

Xiao, Dong; Johnson, Candace S; Trump, Donald L; Singh, Shivendra V

2004-05-01

Phenethyl isothiocyanate (PEITC), a constituent of many cruciferous vegetables, offers significant protection against cancer in animals induced by a variety of carcinogens. The present study demonstrates that PEITC suppresses proliferation of PC-3 cells in a dose-dependent manner by causing G(2)-M-phase cell cycle arrest and apoptosis. Interestingly, phenyl isothiocyanate (PITC), which is a structural analogue of PEITC but lacks the -CH(2) spacers that link the aromatic ring to the -N=C=S group, neither inhibited PC-3 cell viability nor caused cell cycle arrest or apoptosis. These results indicated that even a subtle change in isothiocyanate (ITC) structure could have a significant impact on its biological activity. The PEITC-induced cell cycle arrest was associated with a >80% reduction in the protein levels of cyclin-dependent kinase 1 (Cdk1) and cell division cycle 25C (Cdc25C; 24 h after treatment with 10 micro M PEITC), which led to an accumulation of Tyr(15) phosphorylated (inactive) Cdk1. On the other hand, PITC treatment neither reduced protein levels of Cdk1 or Cdc25C nor affected Cdk1 phosphorylation. The PEITC-induced decline in Cdk1 and Cdc25C protein levels and cell cycle arrest were significantly blocked on pretreatment of PC-3 cells with proteasome inhibitor lactacystin. A 24 h exposure of PC-3 cells to 10 micro M PEITC, but not PITC, resulted in about 56% and 44% decrease in the levels of antiapoptotic proteins Bcl-2 and Bcl-X(L), respectively. However, ectopic expression of Bcl-2 failed to alter sensitivity of PC-3 cells to growth inhibition or apoptosis induction by PEITC. Treatment of cells with PEITC, but not PITC, also resulted in cleavage of procaspase-3, procaspase-9, and procaspase-8. Moreover, the PEITC-induced apoptosis was significantly attenuated in the presence of general caspase inhibitor and specific inhibitors of caspase-8 and caspase-9. In conclusion, our data indicate that PEITC-induced cell cycle arrest in PC-3 cells is likely due

WEHI-3 cells inhibit adipocyte differentiation in 3T3-L1 cells

Energy Technology Data Exchange (ETDEWEB)

Lai, Jing [The First Affiliated Hospital, Jinan University, Guangzhou, Guangdong (China); Liu, Gexiu [Institute of Hematology, School of Medicine, Jinan University, Guangzhou, Guangdong (China); Yan, Guoyao [The First Affiliated Hospital, Jinan University, Guangzhou, Guangdong (China); He, Dongmei [Institute of Hematology, School of Medicine, Jinan University, Guangzhou, Guangdong (China); Zhou, Ying [The First Affiliated Hospital, Jinan University, Guangzhou, Guangdong (China); Chen, Shengting, E-mail: shengtingchen@sina.cn [The First Affiliated Hospital, Jinan University, Guangzhou, Guangdong (China)

2015-06-26

By investigating the anti-adipogenic effects of WEHI-3 cells – a murine acute myelomonocytic leukemia cell line – we sought to improve the efficiency of hematopoietic stem cell transplantation (HSCT). Analysis of Oil Red O staining and the expression of adipogenic genes, including PPARγ, C/EBPα, FAS and LPL, indicated that WEHI-3 cells significantly inhibited 3T3-L1 mouse preadipocyte cells from differentiating into adipocytes. In vivo, fat vacuoles in mice injected with WEHI-3 cells were also remarkably reduced in the murine bone marrow pimelosis model. Moreover, the key gene in the Rho signaling pathway, ROCKII, and the key gene in the Wnt signaling pathway, β-catenin, were both upregulated compared with the control group. siRNA-mediated knockdown of ROCKII and β-catenin reversed these WEHI-3-mediated anti-adipogenic effects. Taken together, these data suggest that WEHI-3 cells exert anti-adipogenic effects and that both ROCKII and β-catenin are involved in this process. - Highlights: • WEHI-3, an acute myelomonocytic leukemia cell line, inhibited 3T3-L1 preadipocyte from differentiating into adipocyte. • WEHI-3 cells can arrest 3T3-L1 cells in G0/G1 phase by secreting soluble factors and thus inhibit their proliferation. • WEHI-3 cells reduced bone marrow pimelosis in the murine model. • Both ROCKII and β-catenin were involved in the WEHI-3-mediated anti-adipogenic effects.

FOXO1 and GSK-3β Are Main Targets of Insulin-Mediated Myogenesis in C2C12 Muscle Cells.

Science.gov (United States)

Litwiniuk, Anna; Pijet, Barbara; Pijet-Kucicka, Maja; Gajewska, Małgorzata; Pająk, Beata; Orzechowski, Arkadiusz

2016-01-01

Myogenesis and muscle hypertrophy account for muscle growth and adaptation to work overload, respectively. In adults, insulin and insulin-like growth factor 1 stimulate muscle growth, although their links with cellular energy homeostasis are not fully explained. Insulin plays critical role in the control of mitochondrial activity in skeletal muscle cells, and mitochondria are essential for insulin action. The aim of this study was to elucidate molecular mechanism(s) involved in mitochondrial control of insulin-dependent myogenesis. The effects of several metabolic inhibitors (LY294002, PD98059, SB216763, LiCl, rotenone, oligomycin) on the differentiation of C2C12 myoblasts in culture were examined in the short-term (hours) and long-term (days) experiments. Muscle cell viability and mitogenicity were monitored and confronted with the activities of selected genes and proteins expression. These indices focus on the roles of insulin, glycogen synthase kinase 3 beta (GSK-3β) and forkhead box protein O1 (FOXO1) on myogenesis using a combination of treatments and inhibitors. Long-term insulin (10 nM) treatment in "normoglycemic" conditions led to increased myogenin expression and accelerated myogenesis in C2C12 cells. Insulin-dependent myogenesis was accompanied by the rise of mtTFA, MtSSB, Mfn2, and mitochondrially encoded Cox-1 gene expressions and elevated levels of proteins which control functions of mitochondria (kinase--PKB/AKT, mitofusin 2 protein--Mfn-2). Insulin, via the phosphatidylinositol 3-kinase (PI3-K)/AKT-dependent pathway reduced transcription factor FOXO1 activity and altered GSK-3β phosphorylation status. Once FOXO1 and GSK-3β activities were inhibited the rise in Cox-1 gene action and nuclear encoded cytochrome c oxidase subunit IV (COX IV) expressions were observed, even though some mRNA and protein results varied. In contrast to SB216763, LiCl markedly elevated Mfn2 and COX IV protein expression levels when given together with insulin. Thus

FOXO1 and GSK-3β Are Main Targets of Insulin-Mediated Myogenesis in C2C12 Muscle Cells.

Directory of Open Access Journals (Sweden)

Anna Litwiniuk

Full Text Available Myogenesis and muscle hypertrophy account for muscle growth and adaptation to work overload, respectively. In adults, insulin and insulin-like growth factor 1 stimulate muscle growth, although their links with cellular energy homeostasis are not fully explained. Insulin plays critical role in the control of mitochondrial activity in skeletal muscle cells, and mitochondria are essential for insulin action. The aim of this study was to elucidate molecular mechanism(s involved in mitochondrial control of insulin-dependent myogenesis. The effects of several metabolic inhibitors (LY294002, PD98059, SB216763, LiCl, rotenone, oligomycin on the differentiation of C2C12 myoblasts in culture were examined in the short-term (hours and long-term (days experiments. Muscle cell viability and mitogenicity were monitored and confronted with the activities of selected genes and proteins expression. These indices focus on the roles of insulin, glycogen synthase kinase 3 beta (GSK-3β and forkhead box protein O1 (FOXO1 on myogenesis using a combination of treatments and inhibitors. Long-term insulin (10 nM treatment in "normoglycemic" conditions led to increased myogenin expression and accelerated myogenesis in C2C12 cells. Insulin-dependent myogenesis was accompanied by the rise of mtTFA, MtSSB, Mfn2, and mitochondrially encoded Cox-1 gene expressions and elevated levels of proteins which control functions of mitochondria (kinase--PKB/AKT, mitofusin 2 protein--Mfn-2. Insulin, via the phosphatidylinositol 3-kinase (PI3-K/AKT-dependent pathway reduced transcription factor FOXO1 activity and altered GSK-3β phosphorylation status. Once FOXO1 and GSK-3β activities were inhibited the rise in Cox-1 gene action and nuclear encoded cytochrome c oxidase subunit IV (COX IV expressions were observed, even though some mRNA and protein results varied. In contrast to SB216763, LiCl markedly elevated Mfn2 and COX IV protein expression levels when given together with insulin

ATF3 inhibits adipocyte differentiation of 3T3-L1 cells

International Nuclear Information System (INIS)

Jang, Min Kyung; Kim, Cho Hee; Seong, Je Kyung; Jung, Myeong Ho

2012-01-01

Highlights: ► Overexpression of ATF3 inhibits adipocyte differentiation in 3T3-L1 cells. ► Overexpression of ATF3 represses C/EBPα expression. ► ATF3 directly binds to mouse C/EBPα promoter spanning from −1928 to −1907. ► ATF3 may play a role in hypoxia-mediated inhibition of adipocyte differentiation. -- Abstract: ATF3 is a stress-adaptive gene that regulates proliferation or apoptosis under stress conditions. However, the role of ATF3 is unknown in adipocyte cells. Therefore, in this study, we investigated the functional role of ATF3 in adipocytes. Both lentivirus-mediated overexpression of ATF3 and stably-overexpressed ATF3 inhibited adipocyte differentiation in 3T3-L1 cells, as revealed by decreased lipid staining with oil red staining and reduction in adipogenic genes. Thapsigargin treatment and overexpression of ATF3 decreased C/EBPα transcript and repressed the activity of the 3.6-kb mouse C/EBPα promoter, demonstrating that ATF3 downregulates C/EBPα expression. Transfection studies using mutant constructs containing 5′-deletions in the C/EBPα promoter revealed that a putative ATF/CRE element, GGATGTCA, is located between −1921 and −1914. Electrophoretic mobility shift assay and chromatin immunoprecipitation assay demonstrated that ATF3 directly binds to mouse C/EBPα promoter spanning from −1928 to −1907. Both chemical hypoxia-mimetics or physical hypoxia led to reduce the C/EBPα mRNA and repress the promoter activity of the C/EBPα gene, whereas increase ATF3 mRNA, suggesting that ATF3 may contribute to the inhibition of adipocyte differentiation in hypoxia through downregulation of C/EBPα expression. Collectively, these results demonstrate that ATF3 represses the C/EBPα gene, resulting in inhibition of adipocyte differentiation, and thus plays a role in hypoxia-mediated inhibition of adipocyte differentiation.

Involvement of c-Met- and phosphatidylinositol 3-kinase dependent pathways in arsenite-induced downregulation of catalase in hepatoma cells.

Science.gov (United States)

Kim, Soohee; Lee, Seung Heon; Kang, Sukmo; Lee, Lyon; Park, Jung-Duck; Ryu, Doug-Young

2011-01-01

Catalase protects cells from reactive oxygen species-induced damage by catalyzing the breakdown of hydrogen peroxide to oxygen and water. Arsenite decreases catalase activity; it activates phosphatidylinositol 3-kinase (PI3K) and its key downstream effector Akt in a variety of cells. The PI3K pathway is known to inhibit catalase expression. c-Met, an upstream regulator of PI3K and Akt, is also involved in the regulation of catalase expression. To examine the involvement of c-Met and PI3K pathways in the arsenite-induced downregulation of catalase, catalase mRNA and protein expression were analyzed in the human hepatoma cell line HepG2 treated with arsenite and either an inhibitor of c-Met (PHA665752 (PHA)) or of PI3K (LY294002 (LY)). Arsenite treatment markedly activated Akt and decreased the levels of both catalase mRNA and protein. Both PHA and LY attenuated arsenite-induced activation of Akt. PHA and LY treatment also prevented the inhibitory effect of arsenite on catalase protein expression but did not affect the level of catalase mRNA. These findings suggest that arsenite-induced inhibition of catalase expression is regulated at the mRNA and post-transcriptional levels in HepG2 cells, and that the post-transcriptional regulation is mediated via c-Met- and PI3K-dependent mechanisms.

Calculation of 3D genome structures for comparison of chromosome conformation capture experiments with microscopy: An evaluation of single-cell Hi-C protocols.

Science.gov (United States)

Lando, David; Stevens, Tim J; Basu, Srinjan; Laue, Ernest D

2018-01-01

Single-cell chromosome conformation capture approaches are revealing the extent of cell-to-cell variability in the organization and packaging of genomes. These single-cell methods, unlike their multi-cell counterparts, allow straightforward computation of realistic chromosome conformations that may be compared and combined with other, independent, techniques to study 3D structure. Here we discuss how single-cell Hi-C and subsequent 3D genome structure determination allows comparison with data from microscopy. We then carry out a systematic evaluation of recently published single-cell Hi-C datasets to establish a computational approach for the evaluation of single-cell Hi-C protocols. We show that the calculation of genome structures provides a useful tool for assessing the quality of single-cell Hi-C data because it requires a self-consistent network of interactions, relating to the underlying 3D conformation, with few errors, as well as sufficient longer-range cis- and trans-chromosomal contacts.

Thieno[3,4-c]pyrrole-4,6-dione-3,4-difluorothiophene Polymer Acceptors for Efficient All-Polymer Bulk Heterojunction Solar Cells

KAUST Repository

Liu, Shengjian

2016-09-16

Branched-alkyl-substituted poly(thieno[3,4-c]pyrrole-4,6-dione-alt-3,4-difluorothiophene) (PTPD[2F]T) can be used as a polymer acceptor in bulk heterojunction (BHJ) solar cells with a low-band-gap polymer donor (PCE10) commonly used with fullerenes. The

A review on g-C3N4-based photocatalysts

International Nuclear Information System (INIS)

Wen, Jiuqing; Xie, Jun; Chen, Xiaobo; Li, Xin

2017-01-01

Graphical abstract: The photocatalytic fundamentals, versatile properties, design strategies and potential applications of g-C 3 N 4 -based photocatalysts were systematically summarized and addressed. - Highlights: • The photocatalytic fundamentals of g-C 3 N 4 were systematically summarized. • The versatile properties of g-C 3 N 4 photocatalysts were highlighted. • The different design strategies of g-C 3 N 4 photocatalysts were reviewed. • The important photocatalytic applications of g-C 3 N 4 were also addressed. - Abstract: As one of the most appealing and attractive technologies, heterogeneous photocatalysis has been utilized to directly harvest, convert and store renewable solar energy for producing sustainable and green solar fuels and a broad range of environmental applications. Due to their unique physicochemical, optical and electrical properties, a wide variety of g-C 3 N 4 -based photocatalysts have been designed to drive various reduction and oxidation reactions under light irradiation with suitable wavelengths. In this review, we have systematically summarized the photocatalytic fundamentals of g-C 3 N 4 -based photocatalysts, including fundamental mechanism of heterogeneous photocatalysis, advantages, challenges and the design considerations of g-C 3 N 4 -based photocatalysts. The versatile properties of g-C 3 N 4 -based photocatalysts are highlighted, including their crystal structural, surface phisicochemical, stability, optical, adsorption, electrochemical, photoelectrochemical and electronic properties. Various design strategies are also thoroughly reviewed, including band-gap engineering, defect control, dimensionality tuning, pore texture tailoring, surface sensitization, heterojunction construction, co-catalyst and nanocarbon loading. Many important applications are also addressed, such as photocatalytic water splitting (H 2 evolution and overall water splitting), degradation of pollutants, carbon dioxide reduction, selective organic

3',5'-Cyclic diguanylic acid (c-di-GMP) inhibits basal and growth factor-stimulated human colon cancer cell proliferation

International Nuclear Information System (INIS)

Karaolis, David K.R.; Cheng, Kunrong; Lipsky, Michael; Elnabawi, Ahmed; Catalano, Jennifer; Hyodo, Mamoru; Hayakawa, Yoshihiro; Raufman, Jean-Pierre

2005-01-01

The novel cyclic dinucleotide, 3',5'-cyclic diguanylic acid, cGpGp (c-di-GMP), is a naturally occurring small molecule that regulates important signaling mechanisms in prokaryotes. Recently, we showed that c-di-GMP has 'drug-like' properties and that c-di-GMP treatment might be a useful antimicrobial approach to attenuate the virulence and pathogenesis of Staphylococcus aureus and prevent or treat infection. In the present communication, we report that c-di-GMP (≤50 μM) has striking properties regarding inhibition of cancer cell proliferation in vitro. c-di-GMP inhibits both basal and growth factor (acetylcholine and epidermal growth factor)-induced cell proliferation of human colon cancer (H508) cells. Toxicity studies revealed that exposure of normal rat kidney cells and human neuroblastoma cells to c-di-GMP at biologically relevant doses showed no lethal cytotoxicity. Cyclic dinucleotides, such as c-di-GMP, represent an attractive and novel 'drug-platform technology' that can be used not only to develop new antimicrobial agents, but also to develop novel therapeutic agents to prevent or treat cancer

MiR-30c regulates cisplatin-induced apoptosis of renal tubular epithelial cells by targeting Bnip3L and Hspa5.

Science.gov (United States)

Du, Bin; Dai, Xiao-Meng; Li, Shuang; Qi, Guo-Long; Cao, Guang-Xu; Zhong, Ying; Yin, Pei-di; Yang, Xue-Song

2017-08-10

As a common anticancer drug, cisplatin has been widely used for treating tumors in the clinic. However, its side effects, especially its nephrotoxicity, noticeably restrict the application of cisplatin. Therefore, it is imperative to investigate the mechanism of renal injury and explore the corresponding remedies. In this study, we showed the phenotypes of the renal tubules and epithelial cell death as well as elevated cleaved-caspase3- and TUNEL-positive cells in rats intraperitoneally injected with cisplatin. Similar cisplatin-induced cell apoptosis was found in HK-2 and NRK-52E cells exposed to cisplatin as well. In both models of cisplatin-induced apoptosis in vivo and in vitro, quantitative PCR data displayed reductions in miR-30a-e expression levels, indicating that miR-30 might be involved in regulating cisplatin-induced cell apoptosis. This was further confirmed when the effects of cisplatin-induced cell apoptosis were found to be closely correlated with alterations in miR-30c expression, which were manipulated by transfection of either the miR-30c mimic or miR-30c inhibitor in HK-2 and NRK-52E cells. Using bioinformatics tools, including TargetScan and a gene expression database (Gene Expression Omnibus), Adrb1, Bnip3L, Hspa5 and MAP3K12 were predicted to be putative target genes of miR-30c in cisplatin-induced apoptosis. Subsequently, Bnip3L and Hspa5 were confirmed to be the target genes after determining the expression of these putative genes following manipulation of miR-30c expression levels in HK-2 cells. Taken together, our current experiments reveal that miR-30c is certainly involved in regulating the renal tubular cell apoptosis induced by cisplatin, which might supply a new strategy to minimize cisplatin-induced nephrotoxicity.

Human and pneumococcal cell surface glyceraldehyde-3-phosphate dehydrogenase (GAPDH) proteins are both ligands of human C1q protein.

Science.gov (United States)

Terrasse, Rémi; Tacnet-Delorme, Pascale; Moriscot, Christine; Pérard, Julien; Schoehn, Guy; Vernet, Thierry; Thielens, Nicole M; Di Guilmi, Anne Marie; Frachet, Philippe

2012-12-14

C1q, a key component of the classical complement pathway, is a major player in the response to microbial infection and has been shown to detect noxious altered-self substances such as apoptotic cells. In this work, using complementary experimental approaches, we identified the glyceraldehyde-3-phosphate dehydrogenase (GAPDH) as a C1q partner when exposed at the surface of human pathogenic bacteria Streptococcus pneumoniae and human apoptotic cells. The membrane-associated GAPDH on HeLa cells bound the globular regions of C1q as demonstrated by pulldown and cell surface co-localization experiments. Pneumococcal strains deficient in surface-exposed GAPDH harbored a decreased level of C1q recognition when compared with the wild-type strains. Both recombinant human and pneumococcal GAPDHs interacted avidly with C1q as measured by surface plasmon resonance experiments (K(D) = 0.34-2.17 nm). In addition, GAPDH-C1q complexes were observed by transmission electron microscopy after cross-linking. The purified pneumococcal GAPDH protein activated C1 in an in vitro assay unlike the human form. Deposition of C1q, C3b, and C4b from human serum at the surface of pneumococcal cells was dependent on the presence of surface-exposed GAPDH. This ability of C1q to sense both human and bacterial GAPDHs sheds new insights on the role of this important defense collagen molecule in modulating the immune response.

Human and Pneumococcal Cell Surface Glyceraldehyde-3-phosphate Dehydrogenase (GAPDH) Proteins Are Both Ligands of Human C1q Protein*

Science.gov (United States)

Terrasse, Rémi; Tacnet-Delorme, Pascale; Moriscot, Christine; Pérard, Julien; Schoehn, Guy; Vernet, Thierry; Thielens, Nicole M.; Di Guilmi, Anne Marie; Frachet, Philippe

2012-01-01

C1q, a key component of the classical complement pathway, is a major player in the response to microbial infection and has been shown to detect noxious altered-self substances such as apoptotic cells. In this work, using complementary experimental approaches, we identified the glyceraldehyde-3-phosphate dehydrogenase (GAPDH) as a C1q partner when exposed at the surface of human pathogenic bacteria Streptococcus pneumoniae and human apoptotic cells. The membrane-associated GAPDH on HeLa cells bound the globular regions of C1q as demonstrated by pulldown and cell surface co-localization experiments. Pneumococcal strains deficient in surface-exposed GAPDH harbored a decreased level of C1q recognition when compared with the wild-type strains. Both recombinant human and pneumococcal GAPDHs interacted avidly with C1q as measured by surface plasmon resonance experiments (KD = 0.34–2.17 nm). In addition, GAPDH-C1q complexes were observed by transmission electron microscopy after cross-linking. The purified pneumococcal GAPDH protein activated C1 in an in vitro assay unlike the human form. Deposition of C1q, C3b, and C4b from human serum at the surface of pneumococcal cells was dependent on the presence of surface-exposed GAPDH. This ability of C1q to sense both human and bacterial GAPDHs sheds new insights on the role of this important defense collagen molecule in modulating the immune response. PMID:23086952

Cell density dependence of transformation frequencies in C3H10T1/2 cells exposed to X-rays

Energy Technology Data Exchange (ETDEWEB)

Bettega, D; Calzolari, P; Ottolenghi, A; Lombardi, L T [Milan Univ. (Italy). Ist. di Fisica; Rimoldi, E [Milan Univ. (Italy). Ist. di Radiologia Veterinaria

1989-12-01

The effects of cell density on transformation frequencies were studied in C3H10T1/2 cells exposed to 0.5 and 7 Gy of 200 kVp X-rays. Initial cell density strongly influenced transformation frequency; this decreased by a factor of between 4 and 10 when the initial seeding density was changed from 50 to 2500 cells/10 cm diameter Petri dish. The data were fitted with two equations: (a) an allometric function represented on a log-log scale by a straight line and (b) a sigmoidal function with plateaux between 50 and 250 cells/dish and above 600. The two curves are compared and their probabilities discussed. Our data indicate that the region between 50 and 250 cells/dish would be the most suitable region for dose-effect measurements. A study of the growth curves at 0.5 and 8.5 Gy shows that cell growth rates are not influenced by initial cell density. (author).

Synergistic cytotoxic action of vitamin C and vitamin K3.

Science.gov (United States)

Zhang, W; Negoro, T; Satoh, K; Jiang, Y; Hashimoto, K; Kikuchi, H; Nishikawa, H; Miyata, T; Yamamoto, Y; Nakano, K; Yasumoto, E; Nakayachi, T; Mineno, K; Satoh, T; Sakagami, H

2001-01-01

We investigated the combination effect of sodium ascorbate (vitamin C) and menadione (vitamin K3) on the viability of various cultured cells. Human oral squamous cell carcinoma (HSC-2, HSC-3) and human promyelocytic leukemia (HL-60) cells were more sensitive to these vitamins as compared to normal cells (human gingival fibroblast HGF, human periodontal ligament fibroblast HPLF, human pulp cell HPC). The combination of vitamin C and vitamin K3 produced synergistic cytotoxicity against all these 6 cell lines. Treatment with vitamin C or vitamin K3, or their combination, induced internucleosomal DNA fragmentation only in HL-60 cells, but not in the oral tumor cell lines (HSC-2, HSC-3, HSG). ESR spectroscopy showed that vitamins C and K3 produce radicals under alkaline conditions and that the combination of these two vitamins synergistically enhanced their respective radical intensities.

Down-regulation of eIF4GII by miR-520c-3p represses diffuse large B cell lymphoma development.

Directory of Open Access Journals (Sweden)

Krystyna Mazan-Mamczarz

2014-01-01

Full Text Available Deregulation of the translational machinery is emerging as a critical contributor to cancer development. The contribution of microRNAs in translational gene control has been established however; the role of microRNAs in disrupting the cap-dependent translation regulation complex has not been previously described. Here, we established that elevated miR-520c-3p represses global translation, cell proliferation and initiates premature senescence in HeLa and DLBCL cells. Moreover, we demonstrate that miR-520c-3p directly targets translation initiation factor, eIF4GII mRNA and negatively regulates eIF4GII protein synthesis. miR-520c-3p overexpression diminishes cells colony formation and reduces tumor growth in a human xenograft mouse model. Consequently, downregulation of eIF4GII by siRNA decreases translation, cell proliferation and ability to form colonies, as well as induces cellular senescence. In vitro and in vivo findings were further validated in patient samples; DLBCL primary cells demonstrated low miR-520c-3p levels with reciprocally up-regulated eIF4GII protein expression. Our results provide evidence that the tumor suppressor effect of miR-520c-3p is mediated through repression of translation while inducing senescence and that eIF4GII is a key effector of this anti-tumor activity.

Epstein-Barr virus nuclear antigen 3C stabilizes Gemin3 to block p53-mediated apoptosis.

Directory of Open Access Journals (Sweden)

Qiliang Cai

2011-12-01

Full Text Available The Epstein-Barr nuclear antigen 3C (EBNA3C, one of the essential latent antigens for Epstein-Barr virus (EBV-induced immortalization of primary human B lymphocytes in vitro, has been implicated in regulating cell proliferation and anti-apoptosis via interaction with several cellular and viral factors. Gemin3 (also named DDX20 or DP103 is a member of DEAD RNA helicase family which exhibits diverse cellular functions including DNA transcription, recombination and repair, and RNA metabolism. Gemin3 was initially identified as a binding partner to EBNA2 and EBNA3C. However, the mechanism by which EBNA3C regulates Gemin3 function remains unclear. Here, we report that EBNA3C directly interacts with Gemin3 through its C-terminal domains. This interaction results in increased stability of Gemin3 and its accumulation in both B lymphoma cells and EBV transformed lymphoblastoid cell lines (LCLs. Moreover, EBNA3C promotes formation of a complex with p53 and Gemin3 which blocks the DNA-binding affinity of p53. Small hairpin RNA based knockdown of Gemin3 in B lymphoma or LCL cells remarkably attenuates the ability of EBNA3C to inhibit the transcription activity of p53 on its downstream genes p21 and Bax, as well as apoptosis. These findings provide the first evidence that Gemin3 may be a common target of oncogenic viruses for driving cell proliferation and anti-apoptotic activities.

Investigation of a Pt3Sn/C Electro-Catalyst in a Direct Ethanol Fuel Cell Operating at Low Temperatures for Portable Applications

OpenAIRE

Zignani, S. C.; Gonzalez, E. R.; Baglio, V.; Siracusano, S.; Arico, A. S.

2012-01-01

A 20% Pt3Sn/C catalyst was prepared by reduction with formic acid and used in a direct ethanol fuel cell at low temperatures. The electro-catalytic activity of this bimetallic catalyst was compared to that of a commercial 20% Pt/C catalyst. The PtSn catalyst showed better results in the investigated temperature range (30 degrees-70 degrees C). Generally, Sn promotes ethanol oxidation by adsorption of OH species at considerably lower potentials compared to Pt, allowing the occurrence of a bifu...

A new cell-based assay to evaluate myogenesis in mouse myoblast C2C12 cells

Energy Technology Data Exchange (ETDEWEB)

Kodaka, Manami [Department of Medical Biochemistry, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, Tokyo (Japan); Yang, Zeyu [Department of Medical Biochemistry, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, Tokyo (Japan); Department of Ultrasound, Shengjing Hospital of China Medical University, Shenyang (China); Nakagawa, Kentaro; Maruyama, Junichi [Department of Medical Biochemistry, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, Tokyo (Japan); Xu, Xiaoyin [Department of Medical Biochemistry, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, Tokyo (Japan); Department of Breast Surgery, The Second Affiliated Hospital of Wenzhou Medical University, Wenzhou (China); Sarkar, Aradhan; Ichimura, Ayana [Department of Medical Biochemistry, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, Tokyo (Japan); Nasu, Yusuke [Department of Breast Surgery, The Second Affiliated Hospital of Wenzhou Medical University, Wenzhou (China); Ozawa, Takeaki [Department of Chemistry, School of Science, The University of Tokyo, Tokyo (Japan); Iwasa, Hiroaki [Department of Medical Biochemistry, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, Tokyo (Japan); Ishigami-Yuasa, Mari [Chemical Biology Screening Center, Tokyo Medical and Dental University, Tokyo (Japan); Ito, Shigeru [Institute of Biomaterials and Bioengineering, Tokyo Medical and Dental University, Tokyo (Japan); Kagechika, Hiroyuki [Chemical Biology Screening Center, Tokyo Medical and Dental University, Tokyo (Japan); Institute of Biomaterials and Bioengineering, Tokyo Medical and Dental University, Tokyo (Japan); and others

2015-08-15

The development of the efficient screening system of detecting compounds that promote myogenesis and prevent muscle atrophy is important. Mouse C2C12 cells are widely used to evaluate myogenesis but the procedures of the assay are not simple and the quantification is not easy. We established C2C12 cells expressing the N-terminal green fluorescence protein (GFP) and the C-terminal GFP (GFP1–10 and GFP11 cells). GFP1–10 and GFP11 cells do not exhibit GFP signals until they are fused. The signal intensity correlates with the expression of myogenic markers and myofusion. Myogenesis-promoting reagents, such as insulin-like growth factor-1 (IGF1) and β-guanidinopropionic acid (GPA), enhance the signals, whereas the poly-caspase inhibitor, z-VAD-FMK, suppresses it. GFP signals are observed when myotubes formed by GFP1–10 cells are fused with single nuclear GFP11 cells, and enhanced by IGF1, GPA, and IBS008738, a recently-reported myogenesis-promoting reagent. Fusion between myotubes formed by GFP1–10 and GFP11 cells is associated with the appearance of GFP signals. IGF1 and GPA augment these signals, whereas NSC23766, Rac inhibitor, decreases them. The conditioned medium of cancer cells suppresses GFP signals during myogenesis and reduces the width of GFP-positive myotubes after differentiation. Thus the novel split GFP-based assay will provide the useful method for the study of myogenesis, myofusion, and atrophy. - Highlights: • C2C12 cells expressing split GFP proteins show GFP signals when mix-cultured. • The GFP signals correlate with myogenesis and myofusion. • The GFP signals attenuate under the condition that muscle atrophy is induced.

A new cell-based assay to evaluate myogenesis in mouse myoblast C2C12 cells

International Nuclear Information System (INIS)

Kodaka, Manami; Yang, Zeyu; Nakagawa, Kentaro; Maruyama, Junichi; Xu, Xiaoyin; Sarkar, Aradhan; Ichimura, Ayana; Nasu, Yusuke; Ozawa, Takeaki; Iwasa, Hiroaki; Ishigami-Yuasa, Mari; Ito, Shigeru; Kagechika, Hiroyuki

2015-01-01

The development of the efficient screening system of detecting compounds that promote myogenesis and prevent muscle atrophy is important. Mouse C2C12 cells are widely used to evaluate myogenesis but the procedures of the assay are not simple and the quantification is not easy. We established C2C12 cells expressing the N-terminal green fluorescence protein (GFP) and the C-terminal GFP (GFP1–10 and GFP11 cells). GFP1–10 and GFP11 cells do not exhibit GFP signals until they are fused. The signal intensity correlates with the expression of myogenic markers and myofusion. Myogenesis-promoting reagents, such as insulin-like growth factor-1 (IGF1) and β-guanidinopropionic acid (GPA), enhance the signals, whereas the poly-caspase inhibitor, z-VAD-FMK, suppresses it. GFP signals are observed when myotubes formed by GFP1–10 cells are fused with single nuclear GFP11 cells, and enhanced by IGF1, GPA, and IBS008738, a recently-reported myogenesis-promoting reagent. Fusion between myotubes formed by GFP1–10 and GFP11 cells is associated with the appearance of GFP signals. IGF1 and GPA augment these signals, whereas NSC23766, Rac inhibitor, decreases them. The conditioned medium of cancer cells suppresses GFP signals during myogenesis and reduces the width of GFP-positive myotubes after differentiation. Thus the novel split GFP-based assay will provide the useful method for the study of myogenesis, myofusion, and atrophy. - Highlights: • C2C12 cells expressing split GFP proteins show GFP signals when mix-cultured. • The GFP signals correlate with myogenesis and myofusion. • The GFP signals attenuate under the condition that muscle atrophy is induced

Suppression of X-ray induced transformation by vitamin E in mouse C3H/10T1/2 cells

International Nuclear Information System (INIS)

Radner, B.S.; Kennedy, A.R.

1986-01-01

Vitamin E (d-α-tocopherol) was shown to decrease X-ray induced transformation in mouse C3H/10 1/2 cells. The d-α-tocopherol was active in the form of succinate diluted in ethanol, but was inactive at the highest non-toxic concentration of the pure substance dissolved in oil and diluted in acetone. Vitamin E succinate was effective when present only for the early portion of the radiation transformation assay period, indicating that its effect may be reversible. Vitamin E did not supress the growth and expression of transformed C3H/10 1/2 cells as foci when transformed cells were surrounded by a monolayer of normal cells. (author)

A cell-based biosensor for nanomaterials cytotoxicity assessment in three dimensional cell culture

International Nuclear Information System (INIS)

Dubiak-Szepietowska, Monika; Karczmarczyk, Aleksandra; Winckler, Thomas; Feller, Karl-Heinz

2016-01-01

Nanoparticles (NPs) are widely used in consumer and medicinal products. The high prevalence of nanoparticles in the environment raises concerns regarding their effects on human health, but there is limited knowledge about how NPs interact with cells or tissues. Because the European Union has called for a substantial reduction of animal experiments for scientific purposes (Directive 2010/63), increased efforts are required to develop in vitro models to evaluate potentially hazardous agents. Here, we describe a new cell-based biosensor for the evaluation of NPs cytotoxicity. The new biosensor is based on transgenic human hepatoblastoma cells (HepG2) that express a secreted form of alkaline phosphatase (SEAP) as a reporter protein whose expression is induced upon activation of a stress response pathway controlled by the transcription regulator nuclear factor-κB (NF-κB). The NF-κB-HepG2 sensor cells were cultured in a Matrigel-based three dimensional environment to simulate the in vivo situation. The new biosensor cells offer the advantage of generating fast and reproducible readout at lower concentrations and shorter incubation time than conventional viability assays, avoid possible interaction between nanomaterials and assay compounds, therefore, minimize generation of false positive or negative results and indicate mechanism of toxicity through NF-κB signaling.

MiR-29c regulates the expression of miR-34c and miR-449a by targeting DNA methyltransferase 3a and 3b in nasopharyngeal carcinoma

International Nuclear Information System (INIS)

Niu, Man; Gao, Dan; Wen, Qiuyuan; Wei, Pingpin; Pan, Suming; Shuai, Cijun; Ma, Huiling; Xiang, Juanjuan; Li, Zheng; Fan, Songqing; Li, Guiyuan; Peng, Shuping

2016-01-01

Nasopharyngeal carcinoma (NPC) is prevalent in South East Asia and Southern China particularly, despite the reported 5-year survival ratio is relative higher than other deadly cancers such as liver, renal, pancreas cancer, the lethality is characterized by high metastatic potential in the early stage and high recurrence rate after radiation treatment. MicroRNA-29c was found to be down-regulated in the serum as well as in the tissue of nasopharyngeal carcinoma tissue. In this study, we found accidentally that the transfection of pre-miR-29c or miR-29c mimics significantly increases the expression level of miR-34c and miR-449a but doesn’t affect that of miR-222 using real-time quantitative PCR in nasopharyngeal carcinoma cell lines. To explore the molecular mechanism of the regulatory role, the cells are treated with 5-Aza-2-deoxycytidine (5-Aza-CdR) treatment and the level of miR-34c and miR-449a but not miR-222 accumulated by the treatment. DNA methyltransferase 3a, 3b were down-regulated by the 5-Aza-CdR treatment with western blot and real-time quantitative PCR. We found that pre-miR-29c or miR-29c mimics significantly increases the expression level of miR-34c and miR-449a. We further found DNA methyltransferase 3a and 3b are the target gene of miR-29c. Restoration of miR-29c in NPC cells down-regulated DNA methyltransferase 3a, 3b, but not DNA methyltransferase T1. The regulation of miR-29c/DNMTs/miR-34c/449a is an important molecular axis of NPC development and targeting DNMTs or restoring of miR-29c might be a promising therapy strategy for the prevention of NPC

64 kDa protein is a candidate for a thyrotropin-releasing hormone receptor in prolactin-producing rat pituitary tumor cells (GH4C1 cells)

International Nuclear Information System (INIS)

Wright, M.; Hogset, A.; Alestrom, P.; Gautvik, K.M.

1988-01-01

A thyrotropin-releasing hormone (TRH) binding protein of 64 kDa has been identified by covalently crosslinking [ 3 H]TRH to GH4C1 cells by ultraviolet illumination. The crosslinkage of [ 3 H]TRH is UV-dose dependent and is inhibited by an excess of unlabeled TRH. A 64 kDa protein is also detected on immunoblots using an antiserum raised against GH4C1 cell surface epitopes. In a closely related cell line (GH12C1) which does not bind [ 3 H]TRH, the 64 kDa protein cannot be demonstrated by [ 3 H]TRH crosslinking nor by immunoblotting. These findings indicate that the 64 kDa protein is a candidate for a TRH-receptor protein in GH4C1 cells

Targeting c-Myc: JQ1 as a promising option for c-Myc-amplified esophageal squamous cell carcinoma.

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Wang, Jingyuan; Liu, Zhentao; Wang, Ziqi; Wang, Shubin; Chen, Zuhua; Li, Zhongwu; Zhang, Mengqi; Zou, Jianling; Dong, Bin; Gao, Jing; Shen, Lin

2018-04-10

c-Myc amplification-induced cell cycle dysregulation is a common cause for esophageal squamous cell carcinoma (ESCC), but no approved targeted drug is available so far. The bromodomain inhibitor JQ1, which targets c-Myc, exerts anti-tumor activity in multiple cancers. However, the role of JQ1 in ESCC remains unknown. In this study, we reported that JQ1 had potent anti-proliferative effects on ESCC cells in both time- and dose-dependent manners by inducing cell cycle arrest at G1 phase, cell apoptosis, and the mesenchymal-epithelial transition. Follow-up studies revealed that both c-Myc/cyclin/Rb and PI3K/AKT signaling pathways were inactivated by JQ1, as indicated by the downregulation of c-Myc, cyclin A/E, and phosphorylated Rb, AKT and S6. Tumor suppression induced by JQ1 in c-Myc amplified or highly expressed xenografts was higher than that in xenografts with low expression, suggesting its potential role in prediction. In conclusion, targeting c-Myc by JQ1 could cause significant tumor suppression in ESCC both in vitro and in vivo. Also, c-Myc amplification or high expression might serve as a potential biomarker and provide a promising therapeutic option for ESCC. Copyright © 2018 Elsevier B.V. All rights reserved.

Citrus aurantium L. dry extracts promote C/ebpβ expression and improve adipocyte differentiation in 3T3-L1 cells.

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Raciti, Gregory Alexander; Fiory, Francesca; Campitelli, Michele; Desiderio, Antonella; Spinelli, Rosa; Longo, Michele; Nigro, Cecilia; Pepe, Giacomo; Sommella, Eduardo; Campiglia, Pietro; Formisano, Pietro; Beguinot, Francesco; Miele, Claudia

2018-01-01

Metabolic and/or endocrine dysfunction of the white adipose tissue (WAT) contribute to the development of metabolic disorders, such as Type 2 Diabetes (T2D). Therefore, the identification of products able to improve adipose tissue function represents a valuable strategy for the prevention and/or treatment of T2D. In the current study, we investigated the potential effects of dry extracts obtained from Citrus aurantium L. fruit juice (CAde) on the regulation of 3T3-L1 cells adipocyte differentiation and function in vitro. We found that CAde enhances terminal adipocyte differentiation of 3T3-L1 cells raising the expression of CCAAT/enhancer binding protein beta (C/Ebpβ), peroxisome proliferator activated receptor gamma (Pparγ), glucose transporter type 4 (Glut4) and fatty acid binding protein 4 (Fabp4). CAde improves insulin-induced glucose uptake of 3T3-L1 adipocytes, as well. A focused analysis of the phases occurring in the pre-adipocytes differentiation to mature adipocytes furthermore revealed that CAde promotes the early differentiation stage by up-regulating C/ebpβ expression at 2, 4 and 8 h post the adipogenic induction and anticipating the 3T3-L1 cell cycle entry and progression during mitotic clonal expansion (MCE). These findings provide evidence that the exposure to CAde enhances in vitro fat cell differentiation of pre-adipocytes and functional capacity of mature adipocytes, and pave the way to the development of products derived from Citrus aurantium L. fruit juice, which may improve WAT functional capacity and may be effective for the prevention and/or treatment of T2D.

Unique structure of iC3b resolved at a resolution of 24 Å by 3D-electron microscopy.

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Alcorlo, Martin; Martínez-Barricarte, Ruben; Fernández, Francisco J; Rodríguez-Gallego, César; Round, Adam; Vega, M Cristina; Harris, Claire L; de Cordoba, Santiago Rodríguez; Llorca, Oscar

2011-08-09

Activation of C3, deposition of C3b on the target surface, and subsequent amplification by formation of a C3-cleaving enzyme (C3-convertase; C3bBb) triggers the effector functions of complement that result in inflammation and cell lysis. Concurrently, surface-bound C3b is proteolyzed to iC3b by factor I and appropriate cofactors. iC3b then interacts with the complement receptors (CR) of the Ig superfamily, CR2 (CD21), CR3 (CD11b/CD18), and CR4 (CD11c/CD18) on leukocytes, down-modulating inflammation, enhancing B cell-mediated immunity, and targeting pathogens for clearance by phagocytosis. Using EM and small-angle X-ray scattering, we now present a medium-resolution structure of iC3b (24 Å). iC3b displays a unique conformation with structural features distinct from any other C3 fragment. The macroglobulin ring in iC3b is similar to that in C3b, whereas the TED (thioester-containing domain) domain and the remnants of the CUB (complement protein subcomponents C1r/C1s, urchin embryonic growth factor and bone morphogenetic protein 1) domain have moved to locations more similar to where they were in native C3. A consequence of this large conformational change is the disruption of the factor B binding site, which renders iC3b unable to assemble a C3-convertase. This structural model also justifies the decreased interaction between iC3b and complement regulators and the recognition of iC3b by the CR of the Ig superfamily, CR2, CR3, and CR4. These data further illustrate the extraordinary conformational versatility of C3 to accommodate a great diversity of functional activities.

Skipping of exon 27 in C3 gene compromises TED domain and results in complete human C3 deficiency.

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da Silva, Karina Ribeiro; Fraga, Tatiana Rodrigues; Lucatelli, Juliana Faggion; Grumach, Anete Sevciovic; Isaac, Lourdes

2016-05-01

Primary deficiency of complement C3 is rare and usually associated with increased susceptibility to bacterial infections. In this work, we investigated the molecular basis of complete C3 deficiency in a Brazilian 9-year old female patient with a family history of consanguinity. Hemolytic assays revealed complete lack of complement-mediated hemolytic activity in the patient's serum. While levels of the complement regulatory proteins Factor I, Factor H and Factor B were normal in the patient's and family members' sera, complement C3 levels were undetectable in the patient's serum and were reduced by at least 50% in the sera of the patient's parents and brother. Additionally, no C3 could be observed in the patient's plasma and cell culture supernatants by Western blot. We also observed that patient's skin fibroblasts stimulated with Escherichia coli LPS were unable to secrete C3, which might be accumulated within the cells before being intracellularly degraded. Sequencing analysis of the patient's C3 cDNA revealed a genetic mutation responsible for the complete skipping of exon 27, resulting in the loss of 99 nucleotides (3450-3549) located in the TED domain. Sequencing of the intronic region between the exons 26 and 27 of the C3 gene (nucleotides 6690313-6690961) showed a nucleotide exchange (T→C) at position 6690626 located in a splicing donor site, resulting in the complete skipping of exon 27 in the C3 mRNA. Copyright © 2016. Published by Elsevier GmbH.

A Revised Mechanism for the Activation of Complement C3 to C3b

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Rodriguez, Elizabeth; Nan, Ruodan; Li, Keying; Gor, Jayesh; Perkins, Stephen J.

2015-01-01

The solution structure of complement C3b is crucial for the understanding of complement activation and regulation. C3b is generated by the removal of C3a from C3. Hydrolysis of the C3 thioester produces C3u, an analog of C3b. C3b cleavage results in C3c and C3d (thioester-containing domain; TED). To resolve functional questions in relation to C3b and C3u, analytical ultracentrifugation and x-ray and neutron scattering studies were used with C3, C3b, C3u, C3c, and C3d, using the wild-type allotype with Arg102. In 50 mm NaCl buffer, atomistic scattering modeling showed that both C3b and C3u adopted a compact structure, similar to the C3b crystal structure in which its TED and macroglobulin 1 (MG1) domains were connected through the Arg102–Glu1032 salt bridge. In physiological 137 mm NaCl, scattering modeling showed that C3b and C3u were both extended in structure, with the TED and MG1 domains now separated by up to 6 nm. The importance of the Arg102–Glu1032 salt bridge was determined using surface plasmon resonance to monitor the binding of wild-type C3d(E1032) and mutant C3d(A1032) to immobilized C3c. The mutant did not bind, whereas the wild-type form did. The high conformational variability of TED in C3b in physiological buffer showed that C3b is more reactive than previously thought. Because the Arg102-Glu1032 salt bridge is essential for the C3b-Factor H complex during the regulatory control of C3b, the known clinical associations of the major C3S (Arg102) and disease-linked C3F (Gly102) allotypes of C3b were experimentally explained for the first time. PMID:25488663

Increased deposition of C3b on red cells with low CR1 and CD55 in a malaria-endemic region of western Kenya: Implications for the development of severe anemia

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Odera Michael M

2008-08-01

Full Text Available Abstract Background Severe anemia due to Plasmodium falciparum malaria is a major cause of mortality among young children in western Kenya. The factors that lead to the age-specific incidence of this anemia are unknown. Previous studies have shown an age-related expression of red cell complement regulatory proteins, which protect erythrocytes from autologous complement attack and destruction. Our primary objective was to determine whether in a malaria-endemic area red cells with low levels of complement regulatory proteins are at increased risk for complement (C3b deposition in vivo. Secondarily, we studied the relationship between red cell complement regulatory protein levels and hemoglobin levels. Methods Three hundred and forty-two life-long residents of a malaria-holoendemic region of western Kenya were enrolled in a cross-sectional study and stratified by age. We measured red cell C3b, CR1, CD55, and immune complex binding capacity by flow cytometry. Individuals who were positive for malaria were treated and blood was collected when they were free of parasitemia. Analysis of variance was used to identify independent variables associated with the %C3b-positive red cells and the hemoglobin level. Results Individuals between the ages of 6 and 36 months had the lowest red cell CR1, highest %C3b-positive red cells, and highest parasite density. Malaria prevalence also reached its peak within this age group. Among children ≤ 24 months of age the %C3b-positive red cells was usually higher in individuals who were treated for malaria than in uninfected individuals with similarly low red cell CR1 and CD55. The variables that most strongly influenced the %C3b-positive red cells were age, malaria status, and red cell CD55 level. Although it did not reach statistical significance, red cell CR1 was more important than red cell CD55 among individuals treated for malaria. The variables that most strongly influenced the hemoglobin level were age, the %C3b

Cloning and chromosomal assignment of a human cDNA encoding a T cell- and natural killer cell-specific trypsin-like serine protease

International Nuclear Information System (INIS)

Gershenfeld, H.K.; Hershberger, R.J.; Shows, T.B.; Weissman, I.L.

1988-01-01

A cDNA clone encoding a human T cell- and natural killer cell-specific serine protease was obtained by screening a phage λgt10 cDNA library from phytohemagglutinin-stimulated human peripheral blood lymphocytes with the mouse Hanukah factor cDNA clone. In an RNA blot-hybridization analysis, this human Hanukah factor cDNA hybridized with a 1.3-kilobase band in allogeneic-stimulated cytotoxic T cells and the Jurkat cell line, but this transcript was not detectable in normal muscle, liver, tonsil, or thymus. By dot-blot hybridization, this cDNA hybridized with RNA from three cytolytic T-cell clones and three noncytolytic T-cell clones grown in vitro as well as with purified CD16 + natural killer cells and CD3 + , CD16 - T-cell large granular lymphocytes from peripheral blood lymphocytes (CD = cluster designation). The nucleotide sequence of this cDNA clone encodes a predicted serine protease of 262 amino acids. The active enzyme is 71% and 77% similar to the mouse sequence at the amino acid and DNA level, respectively. The human and mouse sequences conserve the active site residues of serine proteases--the trypsin-specific Asp-189 and all 10 cysteine residues. The gene for the human Hanukah factor serine protease is located on human chromosome 5. The authors propose that this trypsin-like serine protease may function as a common component necessary for lysis of target cells by cytotoxic T lymphocytes and natural killer cells

C2C12 myotubes inhibit the proliferation and differentiation of 3T3-L1 preadipocytes by reducing the expression of glucocorticoid receptor gene

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Chu, Weiwei; Wei, Wei; Yu, Shigang; Han, Haiyin; Shi, Xiaoli [College of Animal Science and Technology, Nanjing Agricultural University, Nanjing 210095 (China); Sun, Wenxing [College of Animal Science and Technology, Nanjing Agricultural University, Nanjing 210095 (China); College of Public Health, Nantong University, Nantong 226019 (China); Gao, Ying [College of Veterinary Medicine, Nanjing Agricultural University, Nanjing 210095 (China); Zhang, Lifan [College of Animal Science and Technology, Nanjing Agricultural University, Nanjing 210095 (China); Chen, Jie, E-mail: jiechen@njau.edu.cn [College of Animal Science and Technology, Nanjing Agricultural University, Nanjing 210095 (China)

2016-03-25

Obesity is a well-established risk factor to health for its relationship with insulin resistance, diabetes and metabolic syndrome. Myocyte-adipocyte crosstalk model plays a significant role in studying the interaction of muscle and adipose development. Previous related studies mainly focus on the effects of adipocytes on the myocytes activity, however, the influence of myotubes on the preadipocytes development remains unclear. The present study was carried out to settle this issue. Firstly, the co-culture experiment showed that the proliferation, cell cycle, and differentiation of 3T3-L1 preadipocytes were arrested, and the apoptosis was induced, by differentiated C2C12 myotubes. Next, the sensitivity of 3T3-L1 preadipocytes to glucocorticoids (GCs), which was well known as cell proliferation, differentiation, apoptosis factor, was decreased after co-cultured with C2C12 myotubes. What's more, our results showed that C2C12 myotubes suppressed the mRNA and protein expression of glucocorticoid receptor (GR) in 3T3-L1 preadipocytes, indicating the potential mechanism of GCs sensitivity reduction. Taken together, we conclude that C2C12 myotubes inhibited 3T3-L1 preadipocytes proliferation and differentiation by reducing the expression of GR. These data suggest that decreasing GR by administration of myokines may be a promising therapy for treating patients with obesity or diabetes. - Highlights: • C2C12 myotubes inhibited proliferation and differentiation of 3T3-L1 preadipocytes. • C2C12 myotubes arrested cell cycle of 3T3-L1 preadipocytes. • C2C12 myotubes induced apoptosis of 3T3-L1 preadipocytes. • C2C12 inhibit 3T3-L1 cells by reducing the expression of glucocorticoid receptor gene.

Design and synthesis of 3,3'-biscoumarin-based c-Met inhibitors.

Science.gov (United States)

Xu, Jimin; Ai, Jing; Liu, Sheng; Peng, Xia; Yu, Linqian; Geng, Meiyu; Nan, Fajun

2014-06-14

A library of biscoumarin-based c-Met inhibitors was synthesized, based on optimization of 3,3'-biscoumarin hit 3, which was identified as a non-ATP competitive inhibitor of c-Met from a diverse library of coumarin derivatives. Among these compounds, 38 and 40 not only showed potent enzyme activities with IC50 values of 107 nM and 30 nM, respectively, but also inhibited c-Met phosphorylation in BaF3/TPR-Met and EBC-1 cells.

In vitro antitumour activity, safety testing and subcellular distribution of two poly[oxyethylene(aminophosphonate-co-H-phosphonate]s in Ehrlich ascites carcinoma and BALB/c 3T3 cell culture systems

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Ani Georgieva

2016-01-01

Full Text Available Two polyphosphoesters containing anthracene-derived aminophosphonate and hydrophilic H-phosphonate repeating units, poly[oxyethylene(aminophosphonate-co-H-phosphonate]s (1 and 2, were tested for the in vitro antitumour activity on cell cultures derived from ascitic form of Ehrlich mammary adenocarcinoma by 3-(4,5-dimethylthiazol-2-yl-2,5-diphenyltetrazolium bromide (MTT-dye reduction assay. The in vitro safety testing of the copolymers was performed by BALB/c 3T3 neutral red uptake assay. A study on their uptake and subcellular distribution in non-tumourigenic and tumour cells was performed by means of fluorescence microscopy. Both copolymers showed significant antitumour activity towards Ehrlich ascites carcinoma (EAC cells. However, the in vitro safety testing revealed significant toxicity of polymer 2 to BALB/c 3T3 mouse embryo cells. In contrast, polymer 1 showed complete absence of cytotoxicity to BALB/c 3T3 cells. The fluorescent studies showed that the substances were diffusely distributed in the cytoplasm in both cell culture systems. As opposed to BALB/c 3T3 cells, in EAC cells, intense fluorescent signal was observed in the nuclei and in the perinuclear region. The tested polyphosphoesters are expected to act under physiological conditions as prodrugs of aminophosphonates.

Enterovirus 71 3C protease cleaves a novel target CstF-64 and inhibits cellular polyadenylation.

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Kuo-Feng Weng

2009-09-01

Full Text Available Identification of novel cellular proteins as substrates to viral proteases would provide a new insight into the mechanism of cell-virus interplay. Eight nuclear proteins as potential targets for enterovirus 71 (EV71 3C protease (3C(pro cleavages were identified by 2D electrophoresis and MALDI-TOF analysis. Of these proteins, CstF-64, which is a critical factor for 3' pre-mRNA processing in a cell nucleus, was selected for further study. A time-course study to monitor the expression levels of CstF-64 in EV71-infected cells also revealed that the reduction of CstF-64 during virus infection was correlated with the production of viral 3C(pro. CstF-64 was cleaved in vitro by 3C(pro but neither by mutant 3C(pro (in which the catalytic site was inactivated nor by another EV71 protease 2A(pro. Serial mutagenesis was performed in CstF-64, revealing that the 3C(pro cleavage sites are located at position 251 in the N-terminal P/G-rich domain and at multiple positions close to the C-terminus of CstF-64 (around position 500. An accumulation of unprocessed pre-mRNA and the depression of mature mRNA were observed in EV71-infected cells. An in vitro assay revealed the inhibition of the 3'-end pre-mRNA processing and polyadenylation in 3C(pro-treated nuclear extract, and this impairment was rescued by adding purified recombinant CstF-64 protein. In summing up the above results, we suggest that 3C(pro cleavage inactivates CstF-64 and impairs the host cell polyadenylation in vitro, as well as in virus-infected cells. This finding is, to our knowledge, the first to demonstrate that a picornavirus protein affects the polyadenylation of host mRNA.

Limonin, a Component of Dictamni Radicis Cortex, Inhibits Eugenol-Induced Calcium and cAMP Levels and PKA/CREB Signaling Pathway in Non-Neuronal 3T3-L1 Cells

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Yeo Cho Yoon

2015-12-01

Full Text Available Limonin, one of the major components in dictamni radicis cortex (DRC, has been shown to play various biological roles in cancer, inflammation, and obesity in many different cell types and tissues. Recently, the odorant-induced signal transduction pathway (OST has gained attention not only because of its function in the perception of smell but also because of its numerous physiological functions in non-neuronal cells. However, little is known about the effects of limonin and DRC on the OST pathway in non-neuronal cells. We investigated odorant-stimulated increases in Ca2+ and cAMP, major second messengers in the OST pathway, in non-neuronal 3T3-L1 cells pretreated with limonin and ethanol extracts of DRC. Limonin and the extracts significantly decreased eugenol-induced Ca2+ and cAMP levels and upregulated phosphorylation of CREB and PKA. Our results demonstrated that limonin and DRC extract inhibit the OST pathway in non-neuronal cells by modulating Ca2+ and cAMP levels and phosphorylation of CREB.

C2-Ceramide Induces Cell Death and Protective Autophagy in Head and Neck Squamous Cell Carcinoma Cells

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Wenyuan Zhu

2014-02-01

Full Text Available Ceramides are second messengers involved in several intracellular processes in cancer cells, amongst others. The aim of this study was to evaluate the anti-tumor efficacy of C2-ceramide (C2-Cer; N-acetyl-D-sphingosine by investigating cell death and autophagy in head and neck squamous cell carcinoma (HNSCC cells. C2-Cer showed concentration-dependent cytotoxicity in HN4 and HN30 cell lines. It simultaneously induced caspase-3-independent apoptosis and programmed necrosis. C2-Cer markedly increased the expression level of microtubule-associated protein 1 light chain 3B (LC3B type II associated with protective autophagy. An autophagy inhibitor enhanced C2-Cer-mediated cytotoxicity, while a programmed-necrosis inhibitor produced the opposite effect. Furthermore, C2-Cer up-regulated the phosphorylation of extracellular signal-regulated kinase 1/2, but down-regulated its downstream substrate phospho-mammalian target of rapamycin (p-mTOR during the autophagy process. These results suggested that C2-Cer exerts anti-tumor effects by inducing programmed apoptosis and necrosis in HNSCC, and these cytotoxic effects are enhanced by an autophagy inhibitor.

Cadherin-related family member 3, a childhood asthma susceptibility gene product, mediates rhinovirus C binding and replication.

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Bochkov, Yury A; Watters, Kelly; Ashraf, Shamaila; Griggs, Theodor F; Devries, Mark K; Jackson, Daniel J; Palmenberg, Ann C; Gern, James E

2015-04-28

Members of rhinovirus C (RV-C) species are more likely to cause wheezing illnesses and asthma exacerbations compared with other rhinoviruses. The cellular receptor for these viruses was heretofore unknown. We report here that expression of human cadherin-related family member 3 (CDHR3) enables the cells normally unsusceptible to RV-C infection to support both virus binding and replication. A coding single nucleotide polymorphism (rs6967330, C529Y) was previously linked to greater cell-surface expression of CDHR3 protein, and an increased risk of wheezing illnesses and hospitalizations for childhood asthma. Compared with wild-type CDHR3, cells transfected with the CDHR3-Y529 variant had about 10-fold increases in RV-C binding and progeny yields. We developed a transduced HeLa cell line (HeLa-E8) stably expressing CDHR3-Y529 that supports RV-C propagation in vitro. Modeling of CDHR3 structure identified potential binding sites that could impact the virus surface in regions that are highly conserved among all RV-C types. Our findings identify that the asthma susceptibility gene product CDHR3 mediates RV-C entry into host cells, and suggest that rs6967330 mutation could be a risk factor for RV-C wheezing illnesses.

Effect of low dose radiation on cytochrome c and caspase-3 protein expressions in spermatogenic cells of mouse testis

International Nuclear Information System (INIS)

Wang Zhicheng; Zhao Hongguang; Piao Chunnan; Liu Guangwei; Liu Shuchun; Lv Zhe; Gong Shouliang

2006-01-01

Objective: To investigate the effect of low dose radiation on the expressions of cytochrome e (Cyt c) and caspase-3 proteins in spermatogenic cells of mouse testis. Methods: The relationships of dose- and time-effect of Cyt c and caspase-3 protein expressions with different dose of X-rays were observed in the spermatogenic cells of mouse testis with immunohistochemical technique (SABC). Results: After irradiation with 0, 0.025, 0.05, 0.075, 0.1 and 0.2 Gy, Cyt c and caspase-3 proteins expressed differently in all kinds of spermatogenic cells, and principally in spermatogonia and spermatocytes, and less in spermatids and spermatozoa. And the expressions increased with the increasing of irradiation dose. The expressions of both proteins after irradiation with 0.075 Gy increased with the lapse of time and reached to the peak at 12 h, and then decreased. Conclusion: Dose-and time-effect exists on the low-dose irradiation induced expressions of Cyt e and caspase-3 proteins in spermatogenic cells of mouse testis. (authors)

1,3-Dichloro-2-propanol inhibits progesterone production through the expression of steroidogenic enzymes and cAMP concentration in Leydig cells.

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Sun, Jianxia; Bai, Shun; Bai, Weibin; Zou, Feiyan; Zhang, Lei; Li, Guoqiang; Hu, Yunfeng; Li, Mingwei; Yan, Rian; Su, Zhijian; Huang, Yadong

2014-07-01

1,3-Dichloro-2-propanol (1,3-DCP) is a well-known food processing contaminant that has been shown to impede male reproductive function. However, its mechanism of action remains elusive. In this study, the effects of 1,3-DCP on progesterone production were investigated using the R2C Leydig cell model. 1,3-DCP significantly reduced cell viability from 7.48% to 97.4% at doses comprised between 0.5 and 6mM. Single cell gel/comet assays and atomic force microscopy assays showed that 1,3-DCP induced early phase cell apoptosis. In addition, 1,3-DCP significantly reduced progesterone production detected by radioimmunoassay (RIA). The results from quantitative polymerase chain reaction and western blotting demonstrated that the mRNA expression levels of steroidogenic acute regulatory protein (StAR), cytochrome P450 side-chain cleavage enzyme and 3β-hydroxysteroid dehydrogenase were significantly down-regulated in R2C cells. Particularly, the change rhythm of Star expression was highly consistent with progesterone production. Furthermore, the cyclic adenosine monophosphate (cAMP) and the mitochondrial membrane potential mediated by ROS, which are involved in regulating progesterone synthesis were also decreased in response to the 1,3-DCP treatment. Overall, the data presented here suggested that 1,3-DCP interferes with the male steroidogenic capacity mainly by down-regulating the level of cAMP and the key enzymes involved in the androgen synthesis pathway. Copyright © 2014 Elsevier Ltd. All rights reserved.

Brugia malayi microfilariae adhere to human vascular endothelial cells in a C3-dependent manner.

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Jan-Hendrik Schroeder

2017-05-01

Full Text Available Brugia malayi causes the human tropical disease, lymphatic filariasis. Microfilariae (Mf of this nematode live in the bloodstream and are ingested by a feeding mosquito vector. Interestingly, in a remarkable co-evolutionary adaptation, Mf appearance in the peripheral blood follows a circadian periodicity and reaches a peak when the mosquito is most likely to feed. For the remaining hours, the majority of Mf sequester in the lung capillaries. This circadian phenomenon has been widely reported and is likely to maximise parasite fitness and optimise transmission potential. However, the mechanism of Mf sequestration in the lungs remains largely unresolved. In this study, we demonstrate that B. malayi Mf can, directly adhere to vascular endothelial cells under static conditions and under flow conditions, they can bind at high (but not low flow rates. High flow rates are more likely to be experienced diurnally. Furthermore, a non-periodic nematode adheres less efficiently to endothelial cells. Strikingly C3, the central component of complement, plays a crucial role in the adherence interaction. These novel results show that microfilariae have the ability to bind to endothelial cells, which may explain their sequestration in the lungs, and this binding is increased in the presence of inflammatory mediators.

Androgen receptor (AR) promotes clear cell renal cell carcinoma (ccRCC) migration and invasion via altering the circHIAT1/miR-195-5p/29a-3p/29c-3p/CDC42 signals.

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Wang, Kefeng; Sun, Yin; Tao, Wei; Fei, Xiang; Chang, Chawnshang

2017-05-28

Increasing evidence has demonstrated that the androgen receptor (AR) plays important roles to promote the metastasis of clear cell renal cell carcinoma (ccRCC). The detailed mechanisms, especially how AR functions via altering the circular RNAs (circRNAs) remain unclear. Here we identified a new circRNA (named as circHIAT1) whose expression was lower in ccRCCs than adjacent normal tissues. Targeting AR could suppress ccRCC cell progression via increasing circHIAT1 expression. ChIP assay and luciferase assay demonstrated that AR suppressed circHIAT1 expression via regulating its host gene, Hippocampus Abundant Transcript 1 (HIAT1) expression at the transcriptional level. The consequences of AR-suppressed circHIAT1 resulted in deregulating miR-195-5p/29a-3p/29c-3p expressions, which increased CDC42 expression to enhance ccRCC cell migration and invasion. Increasing this newly identified signal via circHIAT1 suppressed AR-enhanced ccRCC cell migration and invasion. Together, these results suggested that circHIAT1 functioned as a metastatic inhibitor to suppress AR-enhanced ccRCC cell migration and invasion. Targeting this newly identified AR-circHIAT1-mediated miR-195-5p/29a-3p/29c-3p/CDC42 signals may help us develop potential new therapies to better suppress ccRCC metastasis. Copyright © 2017 Elsevier B.V. All rights reserved.

Interleukin-17A and Toll-Like Receptor 3 Ligand Poly(I:C Synergistically Induced Neutrophil Chemoattractant Production by Bronchial Epithelial Cells.

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Hirotaka Matsuzaki

Full Text Available Chronic inflammatory airway diseases, such as bronchial asthma and chronic obstructive pulmonary disease, are common respiratory disorders worldwide. Exacerbations of these diseases are frequent and worsen patients' respiratory condition and overall health. However, the mechanisms of exacerbation have not been fully elucidated. Recently, it was reported that interleukin (IL-17A might play an important role in neutrophilic inflammation, which is characteristic of such exacerbations, through increased production of neutrophil chemoattractants. Therefore, we hypothesized that IL-17A was involved in the pathogenesis of acute exacerbation, due to viral infection in chronic inflammatory airway diseases. In this study, we assessed chemokine production by bronchial epithelial cells and investigated the underlying mechanisms. Comprehensive chemokine analysis showed that, compared with poly(I:C alone, co-stimulation of BEAS-2B cells with IL-17A and poly(I:C strongly induced production of such neutrophil chemoattractants as CXC chemokine ligand (CXCL8, growth-related oncogene (GRO, and CXCL1. Co-stimulation synergistically induced CXCL8 and CXCL1 mRNA and protein production by BEAS-2B cells and normal human bronchial epithelial cells. Poly(I:C induced chemokine expression by BEAS-2B cells mainly via Toll-like receptor 3/TIR-domain-containing adapter-inducing interferon-β-mediated signals. The co-stimulation with IL-17A and poly(I:C markedly activated the p38 and extracellular-signal-regulated kinase 1/2 pathway, compared with poly(I:C, although there was little change in nuclear factor-κB translocation into the nucleus or the transcriptional activities of nuclear factor-κB and activator protein 1. IL-17A promoted stabilization of CXCL8 mRNA in BEAS-2B cells treated with poly(I:C. In conclusion, IL-17A appears to be involved in the pathogenesis of chronic inflammatory airway disease exacerbation, due to viral infection by promoting release of neutrophil

Intracellular position of mitochondria and chloroplasts in bundle sheath and mesophyll cells of C3 grasses in relation to photorespiratory CO2 loss

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Yuto Hatakeyama

2016-10-01

Full Text Available In C3 plants, photosynthetic efficiency is reduced by photorespiration. A part of CO2 fixed during photosynthesis in chloroplasts is lost from mitochondria during photorespiration by decarboxylation of glycine by glycine decarboxylase (GDC. Thus, the intracellular position of mitochondria in photosynthetic cells is critical to the rate of photorespiratory CO2 loss. We investigated the intracellular position of mitochondria in parenchyma sheath (PS and mesophyll cells of 10 C3 grasses from 3 subfamilies (Ehrhartoideae, Panicoideae, and Pooideae by immunostaining for GDC and light and electron microscopic observation. Immunostaining suggested that many mitochondria were located in the inner half of PS cells and on the vacuole side of chloroplasts in mesophyll cells. Organelle quantification showed that 62–75% of PS mitochondria were located in the inner half of cells, and 62–78% of PS chloroplasts were in the outer half. In mesophyll cells, 61–92% of mitochondria were positioned on the vacuole side of chloroplasts and stromules. In PS cells, such location would reduce the loss of photorespiratory CO2 by lengthening the path of CO2 diffusion and allow more efficient fixation of CO2 from intercellular spaces. In mesophyll cells, it would facilitate scavenging by chloroplasts of photorespiratory CO2 released from mitochondria. Our data suggest that the PS cells of C3 grasses have already acquired an initial structure leading to proto-Kranz and further C3–C4 intermediate anatomy. We also found that in the Pooideae, organelle positioning in PS cells on the phloem side resembles that in mesophyll cells.

Effect of ciguatoxin 3C on voltage-gated Na+ and K+ currents in mouse taste cells.

Science.gov (United States)

Ghiaroni, Valeria; Fuwa, Haruhiko; Inoue, Masayuki; Sasaki, Makoto; Miyazaki, Keisuke; Hirama, Masahiro; Yasumoto, Takeshi; Rossini, Gian Paolo; Scalera, Giuseppe; Bigiani, Albertino

2006-09-01

The marine dinoflagellate Gambierdiscus toxicus produces highly lipophilic, polycyclic ether toxins that cause a seafood poisoning called ciguatera. Ciguatoxins (CTXs) and gambierol represent the two major causative agents of ciguatera intoxication, which include taste alterations (dysgeusiae). However, information on the mode of action of ciguatera toxins in taste cells is scarce. Here, we have studied the effect of synthetic CTX3C (a CTX congener) on mouse taste cells. By using the patch-clamp technique to monitor membrane ion currents, we found that CTX3C markedly affected the operation of voltage-gated Na(+) channels but was ineffective on voltage-gated K(+) channels. This result was the exact opposite of what we obtained earlier with gambierol, which inhibits K(+) channels but not Na(+) channels. Thus, CTXs and gambierol affect with high potency the operation of separate classes of voltage-gated ion channels in taste cells. Our data suggest that taste disturbances reported in ciguatera poisoning might be due to the ability of ciguatera toxins to interfere with ion channels in taste buds.

Lysophosphatidic acid induces reactive oxygen species generation by activating protein kinase C in PC-3 human prostate cancer cells

International Nuclear Information System (INIS)

Lin, Chu-Cheng; Lin, Chuan-En; Lin, Yueh-Chien; Ju, Tsai-Kai; Huang, Yuan-Li; Lee, Ming-Shyue; Chen, Jiun-Hong; Lee, Hsinyu

2013-01-01

Highlights: •LPA induces ROS generation through LPA 1 and LPA 3 . •LPA induces ROS generation by activating PLC. •PKCζ mediates LPA-induced ROS generation. -- Abstract: Prostate cancer is one of the most frequently diagnosed cancers in males, and PC-3 is a cell model popularly used for investigating the behavior of late stage prostate cancer. Lysophosphatidic acid (LPA) is a lysophospholipid that mediates multiple behaviors in cancer cells, such as proliferation, migration and adhesion. We have previously demonstrated that LPA enhances vascular endothelial growth factor (VEGF)-C expression in PC-3 cells by activating the generation of reactive oxygen species (ROS), which is known to be an important mediator in cancer progression. Using flow cytometry, we showed that LPA triggers ROS generation within 10 min and that the generated ROS can be suppressed by pretreatment with the NADPH oxidase (Nox) inhibitor diphenylene iodonium. In addition, transfection with LPA 1 and LPA 3 siRNA efficiently blocked LPA-induced ROS production, suggesting that both receptors are involved in this pathway. Using specific inhibitors and siRNA, phospholipase C (PLC) and protein kinase C (PKC) were also suggested to participate in LPA-induced ROS generation. Overall, we demonstrated that LPA induces ROS generation in PC-3 prostate cancer cells and this is mediated through the PLC/PKC/Nox pathway

Lysophosphatidic acid induces reactive oxygen species generation by activating protein kinase C in PC-3 human prostate cancer cells

Energy Technology Data Exchange (ETDEWEB)

Lin, Chu-Cheng; Lin, Chuan-En; Lin, Yueh-Chien [Institute of Zoology, College of Life Science, National Taiwan University, Taipei, Taiwan, ROC (China); Ju, Tsai-Kai [Instrumentation Center, National Taiwan University, Taipei, Taiwan, ROC (China); Technology Commons, College of Life Science, National Taiwan University, Taipei, Taiwan, ROC (China); Huang, Yuan-Li [Department of Biotechnology, Asia University, Taichung, Taiwan, ROC (China); Lee, Ming-Shyue [Institute of Biochemistry and Molecular Biology, College of Medicine, National Taiwan University, Taipei, Taiwan, ROC (China); Chen, Jiun-Hong [Institute of Zoology, College of Life Science, National Taiwan University, Taipei, Taiwan, ROC (China); Department of Life Science, College of Life Science, National Taiwan University, Taipei, Taiwan, ROC (China); Lee, Hsinyu, E-mail: hsinyu@ntu.edu.tw [Institute of Zoology, College of Life Science, National Taiwan University, Taipei, Taiwan, ROC (China); Department of Life Science, College of Life Science, National Taiwan University, Taipei, Taiwan, ROC (China); Center for Biotechnology, National Taiwan University, Taipei, Taiwan, ROC (China); Research Center for Developmental Biology and Regenerative Medicine, National Taiwan University, Taipei, Taiwan, ROC (China)

2013-11-01

Highlights: •LPA induces ROS generation through LPA{sub 1} and LPA{sub 3}. •LPA induces ROS generation by activating PLC. •PKCζ mediates LPA-induced ROS generation. -- Abstract: Prostate cancer is one of the most frequently diagnosed cancers in males, and PC-3 is a cell model popularly used for investigating the behavior of late stage prostate cancer. Lysophosphatidic acid (LPA) is a lysophospholipid that mediates multiple behaviors in cancer cells, such as proliferation, migration and adhesion. We have previously demonstrated that LPA enhances vascular endothelial growth factor (VEGF)-C expression in PC-3 cells by activating the generation of reactive oxygen species (ROS), which is known to be an important mediator in cancer progression. Using flow cytometry, we showed that LPA triggers ROS generation within 10 min and that the generated ROS can be suppressed by pretreatment with the NADPH oxidase (Nox) inhibitor diphenylene iodonium. In addition, transfection with LPA{sub 1} and LPA{sub 3} siRNA efficiently blocked LPA-induced ROS production, suggesting that both receptors are involved in this pathway. Using specific inhibitors and siRNA, phospholipase C (PLC) and protein kinase C (PKC) were also suggested to participate in LPA-induced ROS generation. Overall, we demonstrated that LPA induces ROS generation in PC-3 prostate cancer cells and this is mediated through the PLC/PKC/Nox pathway.

1,25 dihydroxyvitamin D3 (1,25) regulation of c-myc mRNA in HL-60 leukemia cells

International Nuclear Information System (INIS)

Simpson, R.U.; Bresnick, E.H.; Begley, D.A.

1986-01-01

Recently, 1,25 was shown to induce differentiation and decrease c-myc levels in HL-60 cells. The authors have confirmed these observations by RNA dot blot analysis. Cells treated with 50 nM 1,25 for 4, 24 and 48 hr showed c-myc mRNA levels of 26, 17 and 15% of control respectively. β-Actin mRNA levels were not altered. To ascertain whether 1, 25 regulated c-myc transcriptionally, an HL-60 nuclear RNA runoff assay was developed. Assay of total nuclei transcriptional activity revealed that 50% of RNA elongation was α-amanitin (0.8 μg/ml) sensitive and was linear with nuclei concentration (0.1-1 x 10 7 nuclei). 1,25 (50 nM) treated (45-96 hr) cells had decreased (approx.40%) total transcription rate relative to control. Decreased total RNA synthesis occurred concomitant with NBT reducing activity. 32 P-RNA runoff transcripts from HL-60 nuclei were hybridized to excess (5 μg DNA was excess) Pst I linearized c-myc and β-actin clones (in pBR322) immobilized on nitrocellulose filter. 32 P-RNA input from 2 x 10 6 to 2 x 10 7 cpm yielded linear hybridization signal. Analysis of blot dot intensity revealed no difference in transcription of c-myc in nuclei from 1,25 dosed or control cells. (myc/actin ratios: 1,25 (50 nM, 72 hr) =1.1 +/- 0.3 and control (72 hr) = 1.0, N=3 or 2 or 3 dots ea). These preliminary data suggest 1,25 does not affect c-myc transcription in HL-60 nuclei and may regulate c-myc mRNA post-transcriptionally

The EGFR/ErbB3 Pathway Acts as a Compensatory Survival Mechanism upon c-Met Inhibition in Human c-Met+ Hepatocellular Carcinoma.

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Steven N Steinway

Full Text Available c-Met, a high-affinity receptor for Hepatocyte Growth Factor (HGF, plays a critical role in tumor growth, invasion, and metastasis. Hepatocellular carcinoma (HCC patients with activated HGF/c-Met signaling have a significantly worse prognosis. Targeted therapies using c-Met tyrosine kinase inhibitors are currently in clinical trials for HCC, although receptor tyrosine kinase inhibition in other cancers has demonstrated early success. Unfortunately, therapeutic effect is frequently not durable due to acquired resistance.We utilized the human MHCC97-H c-Met positive (c-Met+ HCC cell line to explore the compensatory survival mechanisms that are acquired after c-Met inhibition. MHCC97-H cells with stable c-Met knockdown (MHCC97-H c-Met KD cells were generated using a c-Met shRNA vector with puromycin selection and stably transfected scrambled shRNA as a control. Gene expression profiling was conducted, and protein expression was analyzed to characterize MHCC97-H cells after blockade of the c-Met oncogene. A high-throughput siRNA screen was performed to find putative compensatory survival proteins, which could drive HCC growth in the absence of c-Met. Findings from this screen were validated through subsequent analyses.We have previously demonstrated that treatment of MHCC97-H cells with a c-Met inhibitor, PHA665752, results in stasis of tumor growth in vivo. MHCC97-H c-Met KD cells demonstrate slower growth kinetics, similar to c-Met inhibitor treated tumors. Using gene expression profiling and siRNA screening against 873 kinases and phosphatases, we identified ErbB3 and TGF-α as compensatory survival factors that are upregulated after c-Met inhibition. Suppressing these factors in c-Met KD MHCC97-H cells suppresses tumor growth in vitro. In addition, we found that the PI3K/Akt signaling pathway serves as a negative feedback signal responsible for the ErbB3 upregulation after c-Met inhibition. Furthermore, in vitro studies demonstrate that

Short Stat5-interacting peptide derived from phospholipase C-β3 inhibits hematopoietic cell proliferation and myeloid differentiation.

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Hiroki Yasudo

Full Text Available Constitutive activation of the transcription factor Stat5 in hematopoietic stem/progenitor cells leads to various hematopoietic malignancies including myeloproliferative neoplasm (MPN. Our recent study found that phospholipase C (PLC-β3 is a novel tumor suppressor involved in MPN, lymphoma and other tumors. Stat5 activity is negatively regulated by the SH2 domain-containing protein phosphatase SHP-1 in a PLC-β3-dependent manner. PLC-β3 can form the multimolecular SPS complex together with SHP-1 and Stat5. The close physical proximity of SHP-1 and Stat5 brought about by interacting with the C-terminal segment of PLC-β3 (PLC-β3-CT accelerates SHP-1-mediated dephosphorylation of Stat5. Here we identify the minimal sequences within PLC-β3-CT required for its tumor suppressor function. Two of the three Stat5-binding noncontiguous regions, one of which also binds SHP-1, substantially inhibited in vitro proliferation of Ba/F3 cells. Surprisingly, an 11-residue Stat5-binding peptide (residues 988-998 suppressed Stat5 activity in Ba/F3 cells and in vivo proliferation and myeloid differentiation of hematopoietic stem/progenitor cells. Therefore, this study further defines PLC-β3-CT as the Stat5- and SHP-1-binding domain by identifying minimal functional sequences of PLC-β3 for its tumor suppressor function and implies their potential utility in the control of hematopoietic malignancies.

Radiobiological properties of spermatogonial stem cells in C3H/101 hybrid mice and evaluation of the model for induction of genetic damage in spermatogonial stem cells

International Nuclear Information System (INIS)

De Rooij, V.

1993-01-01

C3H/101 (3H1) hybrid mice are studied, in order to find answers to the following questions: What are the D 0 values for killing of proliferating and quiescent stem cells by X-irradiation in 3H1 mice; How many stem cells are present per 3H1 testis and what is the density of these cells during the epithelial cycle; What are the approximate numbers of proliferating and quiescent stem cells in a 3H1 mouse testis. (R.P.) 5 figs

Altered sensitivity of system A amino acid transport to ouabain in normal and transformed C3H-10T1/2 cells during the cell cycle

International Nuclear Information System (INIS)

Leister, K.J.; Schenerman, M.A.; Racker, E.

1989-01-01

Quiescent C3H-10T1/2 mouse fibroblasts that have not undergone any type of stress have a relatively low rate of 2-aminoisobutyrate (Aib) uptake by means of system A, which is primarily energized by the transmembrane Na + chemical gradient potential. System A activity in these cells is not sensitive to ouabain or proton ionophores. In contrast, methylcholanthrene-transformed and cofluent C3H-10T1/2 cells treated with ouabain utilize the membrane potential generated by the Na + , K + -ATPase pump to drive Aib transport by means of system A as shown by the sensitivity of transport activity to ouabain and proton ionophores. Since glucose is present during the assay, the proton ionophores do not affect the availability of ATP, as indicated by the undiminished uptake of 86 Rb + by the Na + , K + -ATPase pump. As cells progress through the G 1 phase of the cell cycle, they show an increased system A activity prior to entry into the S phase, which is also dependent on the electrogenicity of the Na + , K + -ATPase pump. There appears to be in all these cases a qualitative shift in the bioenergetic mechanism for the uptake of Aib as well as a marked quantitative increase in Aib uptake. The high activity after ouabain treatment was sustained in the transformed cells after removal of the ouabain, whereas in the confluent 10T1/2 cells the rate of uptake decayed rapidly, suggesting a difference in the mode of regulation. The authors conclude that transformed cells and normal cells in late G 1 or under stress make use of the membrane potential generated by the Na + , K + -ATPase pump to drive amino acid uptake by means of system A

c-erbA and v-erbA modulate growth and gene expression of a mouse glial precursor cell line.

Science.gov (United States)

Iglesias, T; Llanos, S; López-Barahona, M; Pérez-Aranda, A; Rodríguez-Peña, A; Bernal, J; Höhne, A; Seliger, B; Muñoz, A

1994-07-01

The c-erbA alpha protooncogene coding for the thyroid hormone (T3) receptor (TR alpha 1) and the viral, mutated v-erbA oncogene were expressed in an immortal mouse glial cell line (B3.1) using retroviral vectors. c-erbA alpha expression led to a decrease in cell proliferation in high and low serum conditions, both in the presence and in the absence of T3. In serum-free medium, c-erbA-expressing cells (B3.1 + TR alpha 1) were completely arrested, whereas cells expressing v-erbA (B3.1 + v-erbA) showed a higher DNA synthesis rate than normal B3.1 cells. Although proliferation of all three cell types was stimulated by platelet-derived growth factor and basic fibroblast growth factor, differences were also observed in the response to these agents. B3.1 + TR alpha 1 cells were more sensitive to platelet-derived growth factor than B3.1 and B3.1 + v-erbA cells. In contrast, B3.1 cells responded to basic fibroblast growth factor better than B3.1 + TR alpha 1 or B3.1 + v-erbA cells. Insulin-like growth factor I potentiated the action of platelet-derived growth factor and basic fibroblast growth factor. Again, different responses to treatment with insulin-like growth factor I alone were observed; B3.1 + TR alpha 1 cells did not respond to it, whereas B3.1 + v-erbA cells showed a dramatic stimulation by this agent. Interestingly, in the presence of T3, the blockade in B3.1 + TR alpha 1 cell proliferation was accompanied by the down-regulation of the typical astrocytic genes, glial fibrillary acidic protein and vimentin. These hormone effects were not found in v-erbA-expressing cells. In addition, v-erbA inhibited the basal expression of the cyclic nucleotide phosphodiesterase gene, an oligodendrocytic marker.(ABSTRACT TRUNCATED AT 250 WORDS)

Importância do co-cultivo com fibroblastos de camundongo 3T3 para estabelecer cultura de suspensão de células epiteliais do limbo humano Importance of 3T3 feeder layer to establish epithelial cultures from cell suspension obtained from corneo-scleral rims

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Priscila Cardoso Cristovam

2008-10-01

Full Text Available OBJETIVO: Avaliar a importância da presença de células 3T3 para estabelecer cultura de suspensão de células epiteliais do limbo obtido de rimas córneo-esclerais. MÉTODOS: Rimas de diferentes doadores tiveram seus estroma posterior e endotélio removidos (n=6. Cada rima foi dividida em três segmentos iguais, que foram colocados em cultura em três diferentes condições: um segmento foi colocado na placa de cultura com o lado epitelial para cima (Grupo A. Os dois segmentos restantes foram tripsinizados e a suspensão de células obtida foi cultivada com (Grupo B ou sem (Grupo C células 3T3 irradiadas. As células foram mantidas em meio de cultura "supplemental hormonal epithelial médium" (SHEM, a migração epitelial e a formação de clones nos grupos A, B e C foram avaliadas pela microscopia de contraste de fase e por coloração pela rodamina B. Os resultados foram comparados estatisticamente. RESULTADOS: O crescimento de células epiteliais foi observado em 4/6 rimas (Grupo A. Todas as suspensões de células epiteliais que foram cultivadas com células 3T3 (Grupo B formaram clones. Nenhuma adesão ou formação de clones verdadeiros (holo ou meroclones foi observada na cultura de células que foi cultivada sem 3T3 (Grupo C (p=0,009. CONCLUSÕES: Suspensão de células epiteliais límbicas obtidas de rimas córneo-esclerais no modelo utilizado precisa ser cultivada com células 3T3 para formar clones e estabelecer colônias epiteliais com perspectivas para uso terapêutico na reconstrução da superfície ocular.PURPOSE: To evaluate the importance of the presence of 3T3 fibroblasts for establishing limbal epithelial cultures from cell suspension obtained from corneo-scleral rims (CSR. METHODS: Corneo-scleral rims from different donors (n=6 had their posterior stroma and endothelium stripped away. Each corneo-scleral rim was divided into three equal segments that were set up in tissue culture in three different conditions: one of the

Radiation effects in C cells

International Nuclear Information System (INIS)

Alcaraz Banos, M.; Garcia Ayala, A.; Meseguer Penalver, J.; Genoves Garcia, J.L.

1994-01-01

The para follicular cell (C cell) ultrastructure of euthyroid, propyl thiouracil-treated (PTU) and protyrreline-treated (TRH) irradiated rabbit thyroid gland was studied. The ultrastructural features of C cells in the non-irradiated thyroid glands were similar to those described in other mammals. We have not observed the disappearance of the C cells in irradiated thyroid glands. Clusters of C cells were occasionally observed in the irradiated glands. The irradiated C cells showed intranuclear, filamentous bundles and a dense body together with a well-developed endoplasmic reticulum and numerous secretory vesicles. C cells follicles could be observed in irradiated and TRH-treated animals. (Author)

Caspase activity and apoptotic signaling in proliferating C2C12 cells following cisplatin or A23187 exposure

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Darin Bloemberg

2016-06-01

Full Text Available Investigating cell death signaling using cell culture is commonly performed to examine the effects of novel pharmaceuticals or to further characterize discrete cellular signaling pathways. Here, we provide data regarding the cell death response to either cisplatin or A23187 in sub-confluent C2C12 cells, by utilizing several concentrations and incubation times for each chemical. These data include an assessment of the activation of the proteolytic enzymes caspase-3, caspase-8, caspase-9, calpain, and cathepsin B/L. Additionally, the expression of the apoptosis-regulating proteins Bax, Bcl2, and p53 are presented.

The chicken c-erbA alpha-product induces expression of thyroid hormone-responsive genes in 3,5,3'-triiodothyronine receptor-deficient rat hepatoma cells

DEFF Research Database (Denmark)

Muñoz, A; Höppner, W; Sap, J

1990-01-01

To determine the capacity of the chicken c-erbA (cTR-alpha) gene product in regulating expression of known thyroid hormone-responsive genes, both the cTR-alpha and the viral v-erbA genes were expressed in FAO cells, a rat hepatoma cell line defective for functional thyroid hormone receptors. Upon...

Anti-Apoptotic Signature in Thymic Squamous Cell Carcinomas - Functional Relevance of Anti-Apoptotic BIRC3 Expression in the Thymic Carcinoma Cell Line 1889c.

Science.gov (United States)

Huang, Bei; Belharazem, Djeda; Li, Li; Kneitz, Susanne; Schnabel, Philipp A; Rieker, Ralf J; Körner, Daniel; Nix, Wilfred; Schalke, Berthold; Müller-Hermelink, Hans Konrad; Ott, German; Rosenwald, Andreas; Ströbel, Philipp; Marx, Alexander

2013-01-01

The molecular pathogenesis of thymomas and thymic carcinomas (TCs) is poorly understood and results of adjuvant therapy are unsatisfactory in case of metastatic disease and tumor recurrence. For these clinical settings, novel therapeutic strategies are urgently needed. Recently, limited sequencing efforts revealed that a broad spectrum of genes that play key roles in various common cancers are rarely affected in thymomas and TCs, suggesting that other oncogenic principles might be important. This made us re-analyze historic expression data obtained in a spectrum of thymomas and thymic squamous cell carcinomas (TSCCs) with a custom-made cDNA microarray. By cluster analysis, different anti-apoptotic signatures were detected in type B3 thymoma and TSCC, including overexpression of BIRC3 in TSCCs. This was confirmed by qRT-PCR in the original and an independent validation set of tumors. In contrast to several other cancer cell lines, the BIRC3-positive TSCC cell line, 1889c showed spontaneous apoptosis after BIRC3 knock-down. Targeting apoptosis genes is worth testing as therapeutic principle in TSCC.

Anti-apoptotic signature in thymic squamous cell carcinomas - functional relevance of anti-apoptotic BIRC3 expression in the thymic carcinoma cell line 1889c

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Bei eHuang

2013-12-01

Full Text Available The molecular pathogenesis of thymomas and thymic carcinomas (TCs is poorly understood and results of adjuvant therapy are unsatisfactory in case of metastatic disease and tumor recurrence. For these clinical settings, novel therapeutic strategies are urgently needed. Recently, limited sequencing efforts revealed that a broad spectrum of genes that play key roles in various common cancers are rarely affected in thymomas and thymic carcinomas, suggesting that other oncogenic principles might be important. This made us re-analyze historic expression data obtained in a spectrum of thymomas and thymic squamous cell carcinomas (TSCC with a custom made cDNA microarray. By cluster analysis, different anti-apoptotic signatures were detected in type B3 thymoma and TSCC, including overexpression of BIRC3 in TSCCs. This was confirmed by qRT-PCR in the original and an independent validation set of tumors. In contrast to several other cancer cell lines, the BIRC3-positive TSCC cell line, 1889c showed spontaneous apoptosis after BIRC3 knock-down. Targeting apoptosis genes is worth testing as therapeutic principle in TSCC.

Garcinol from Garcinia indica Downregulates Cancer Stem-like Cell Biomarker ALDH1A1 in Nonsmall Cell Lung Cancer A549 Cells through DDIT3 Activation.

Science.gov (United States)

Wang, Jinhan; Wang, Liwen; Ho, Chi-Tang; Zhang, Kunsheng; Liu, Qiang; Zhao, Hui

2017-05-10

Nonsmall cell lung cancer (NSCLC) is the predominant type of lung cancer. Patients with NSCLC show high mortality rates because of failure to clean up cancer stem cells (CSCs). The anticancer activity of phytochemical garcinol has been identified in various cancer cell models. However, the effect of garcinol on NSCLC cell lines is still lacking. Of the NSCLC cell lines we tested, A549 cells were the most sensitive to garcinol. Interestingly, Aldehyde Dehydrogenase 1 Family Member A1 (ALDH1A1) was preferentially expressed in A549 cells and downregulated by the addition of garcinol. We also found that garcinol enriched DNA damage-inducible transcript 3 (DDIT3) and then altered DDIT3-CCAAT-enhancer-binding proteins beta (C/EBPβ) interaction resulting in a decreased binding of C/EBPβ to the endogenous ALDH1A1 promoter. Furthermore, garcinol's inhibition of ALDH1A1 was identified in a xenograft mice model. Garcinol repressed ALDH1A1 transcription in A549 cells through alterations in the interaction between DDIT3 and C/EBPβ. Garcinol could be a potential dietary phytochemical candidate for NSCLCs patients whose tumors harbored high ALDH1A1 expression.

Phenyl Saligenin Phosphate Induced Caspase-3 and c-Jun N-Terminal Kinase Activation in Cardiomyocyte-Like Cells.

Science.gov (United States)

Felemban, Shatha G; Garner, A Christopher; Smida, Fathi A; Boocock, David J; Hargreaves, Alan J; Dickenson, John M

2015-11-16

At present, little is known about the effect(s) of organophosphorous compounds (OPs) on cardiomyocytes. In this study, we have investigated the effects of phenyl saligenin phosphate (PSP), two organophosphorothioate insecticides (diazinon and chlorpyrifos), and their acutely toxic metabolites (diazoxon and chlorpyrifos oxon) on mitotic and differentiated H9c2 cardiomyoblasts. OP-induced cytotoxicity was assessed by monitoring MTT reduction, LDH release, and caspase-3 activity. Cytotoxicity was not observed with diazinon, diazoxon, or chlorpyrifos oxon (48 h exposure; 200 μM). Chlorpyrifos-induced cytotoxicity was only evident at concentrations >100 μM. In marked contrast, PSP displayed pronounced cytotoxicity toward mitotic and differentiated H9c2 cells. PSP triggered the activation of JNK1/2 but not ERK1/2, p38 MAPK, or PKB, suggesting a role for this pro-apoptotic protein kinase in PSP-induced cell death. The JNK1/2 inhibitor SP 600125 attenuated PSP-induced caspase-3 and JNK1/2 activation, confirming the role of JNK1/2 in PSP-induced cytotoxicity. Fluorescently labeled PSP (dansylated PSP) was used to identify novel PSP binding proteins. Dansylated PSP displayed cytotoxicity toward differentiated H9c2 cells. 2D-gel electrophoresis profiles of cells treated with dansylated PSP (25 μM) were used to identify proteins fluorescently labeled with dansylated PSP. Proteomic analysis identified tropomyosin, heat shock protein β-1, and nucleolar protein 58 as novel protein targets for PSP. In summary, PSP triggers cytotoxicity in differentiated H9c2 cardiomyoblasts via JNK1/2-mediated activation of caspase-3. Further studies are required to investigate whether the identified novel protein targets of PSP play a role in the cytotoxicity of this OP, which is usually associated with the development of OP-induced delayed neuropathy.

X-radiation-induced transformation in a C3H mouse embryo-derived cell line

International Nuclear Information System (INIS)

Terzaghi, M.; Little, J.B.

1976-01-01

Reproducible x-ray-induced oncogenic transformation has been demonstrated in an established cell line of mouse embryo fibroblasts. Cells derived from transformed foci formed malignant tumors when injected into syngeneic hosts. An exponential increase in the number of transformants per viable cell occurred with doses of up to 400 rads of x-radiation. The transformation frequency in exponentially growing cultures remained constant at 2.3 x 10 -3 following doses of 400 to 1500 rads. There was little change in survival following x-ray doses up to 300 rads. Doses greater than 300 rads were associated with an exponential decline in survival; the D 0 for the survival curve was 175 rads. Transformation frequency varied with changes in the number of viable cells seeded per dish. There was about a 10-fold decline in the transformation frequency when the number of cells was increased from 400 to 1000 viable cells/100-mm Petri dish. Below this density range there was little change in transformation frequency. The presence of lethally preirradiated cells was not associated with an enhancement of transformation in irradiated cells or with the induction of transformation in unirradiated cell cultures. Amphotericin B (Fungizone) inhibited the appearance of transformants when added to the culture medium within 2 to 3 weeks after initiation of the experiment

c-Myc-Dependent Cell Competition in Human Cancer Cells.

Science.gov (United States)

Patel, Manish S; Shah, Heta S; Shrivastava, Neeta

2017-07-01

Cell Competition is an interaction between cells for existence in heterogeneous cell populations of multicellular organisms. This phenomenon is involved in initiation and progression of cancer where heterogeneous cell populations compete directly or indirectly for the survival of the fittest based on differential gene expression. In Drosophila, cells having lower dMyc expression are eliminated by cell competition through apoptosis when present in the milieu of cells having higher dMyc expression. Thus, we designed a study to develop c-Myc (human homolog) dependent in vitro cell competition model of human cancer cells. Cells with higher c-Myc were transfected with c-myc shRNA to prepare cells with lower c-Myc and then co-cultured with the same type of cells having a higher c-Myc in equal ratio. Cells with lower c-Myc showed a significant decrease in numbers when compared with higher c-Myc cells, suggesting "loser" and "winner" status of cells, respectively. During microscopy, engulfment of loser cells by winner cells was observed with higher expression of JNK in loser cells. Furthermore, elimination of loser cells was prevented significantly, when co-cultured cells were treated with the JNK (apoptosis) inhibitor. Above results indicate elimination of loser cells in the presence of winner cells by c-Myc-dependent mechanisms of cell competition in human cancer cells. This could be an important mechanism in human tumors where normal cells are eliminated by c-Myc-overexpressed tumor cells. J. Cell. Biochem. 118: 1782-1791, 2017. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

Ginkgolide C Suppresses Adipogenesis in 3T3-L1 Adipocytes via the AMPK Signaling Pathway

Directory of Open Access Journals (Sweden)

Chian-Jiun Liou

2015-01-01

Full Text Available Ginkgolide C, isolated from Ginkgo biloba leaves, is a flavone reported to have multiple biological functions, from decreased platelet aggregation to ameliorating Alzheimer disease. The study aim was to evaluate the antiadipogenic effect of ginkgolide C in 3T3-L1 adipocytes. Ginkgolide C was used to treat differentiated 3T3-L1 cells. Cell supernatant was collected to assay glycerol release, and cells were lysed to measure protein and gene expression related to adipogenesis and lipolysis by western blot and real-time PCR, respectively. Ginkgolide C significantly suppressed lipid accumulation in differentiated adipocytes. It also decreased adipogenesis-related transcription factor expression, including peroxisome proliferator-activated receptor and CCAAT/enhancer-binding protein. Furthermore, ginkgolide C enhanced adipose triglyceride lipase and hormone-sensitive lipase production for lipolysis and increased phosphorylation of AMP-activated protein kinase (AMPK, resulting in decreased activity of acetyl-CoA carboxylase for fatty acid synthesis. In coculture with an AMPK inhibitor (compound C, ginkgolide C also improved activation of sirtuin 1 and phosphorylation of AMPK in differentiated 3T3-L1 cells. The results suggest that ginkgolide C is an effective flavone for increasing lipolysis and inhibiting adipogenesis in adipocytes through the activated AMPK pathway.

EBNA3C Directs Recruitment of RBPJ (CBF1) to Chromatin during the Process of Gene Repression in EBV Infected B Cells.

Science.gov (United States)

Kalchschmidt, Jens S; Gillman, Adam C T; Paschos, Kostas; Bazot, Quentin; Kempkes, Bettina; Allday, Martin J

2016-01-01

It is well established that Epstein-Barr virus nuclear antigen 3C (EBNA3C) can act as a potent repressor of gene expression, but little is known about the sequence of events occurring during the repression process. To explore further the role of EBNA3C in gene repression-particularly in relation to histone modifications and cell factors involved-the three host genes previously reported as most robustly repressed by EBNA3C were investigated. COBLL1, a gene of unknown function, is regulated by EBNA3C alone and the two co-regulated disintegrin/metalloproteases, ADAM28 and ADAMDEC1 have been described previously as targets of both EBNA3A and EBNA3C. For the first time, EBNA3C was here shown to be the main regulator of all three genes early after infection of primary B cells. Using various EBV-recombinants, repression over orders of magnitude was seen only when EBNA3C was expressed. Unexpectedly, full repression was not achieved until 30 days after infection. This was accurately reproduced in established LCLs carrying EBV-recombinants conditional for EBNA3C function, demonstrating the utility of the conditional system to replicate events early after infection. Using this system, detailed chromatin immunoprecipitation analysis revealed that the initial repression was associated with loss of activation-associated histone modifications (H3K9ac, H3K27ac and H3K4me3) and was independent of recruitment of polycomb proteins and deposition of the repressive H3K27me3 modification, which were only observed later in repression. Most remarkable, and in contrast to current models of RBPJ in repression, was the observation that this DNA-binding factor accumulated at the EBNA3C-binding sites only when EBNA3C was functional. Transient reporter assays indicated that repression of these genes was dependent on the interaction between EBNA3C and RBPJ. This was confirmed with a novel EBV-recombinant encoding a mutant of EBNA3C unable to bind RBPJ, by showing this virus was incapable of