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RCC Cells (rcc + cell)
Terms modified by RCC Cells Selected AbstractsDNA methylation and histone modifications cause silencing of Wnt antagonist gene in human renal cell carcinoma cell linesINTERNATIONAL JOURNAL OF CANCER, Issue 3 2008Ken Kawamoto Abstract Secreted frizzled-related protein 2 (sFRP2) is a negative modulator of the Wingless-type (Wnt) signaling pathway, and shown to be inactivated in renal cell carcinoma (RCC). However, the molecular mechanism of silencing of sFRP2 is not fully understood. Our study was designed to elucidate the silencing mechanism of sFRP2 in RCC. Expression of sFRP2 was examined in 20 pairs of primary cancers by immunohistochemistry. Kidney cell lines (HK-2, Caki-1, Caki-2, A-498 and ACHN) were analyzed for sFRP2 expression using real-time RT-PCR and Western blotting. The methylation status at 46 CpG sites of the 2 CpG islands in the sFRP2 promoter was characterized by bisulfite DNA sequencing. Histone modifications were assessed by chromatin immunoprecipitation (ChIP) assay using antibodies against AcH3, AcH4, H3K4 and H3K9. sFRP2 was frequently repressed in primary cancers and in RCC cells. The majority of sFRP2 negative cells had a methylated promoter. Meanwhile, sFRP2 expression was repressed by a hypomethylated promoter in Caki-1 cells, and these cells had a repressive histone modification at the promoter. In Caki-1 cells, sFRP2 was reactivated by trichostatin A (TSA). Repressive histone modifications were also observed in RCC cells with hypermethylated promoters, but sFRP2 was reactivated only by 5-aza-2,-deoxycytidine (DAC) and not by TSA. However, the activation of the silenced sFRP2 gene could be achieved in all cells using a combination of DAC and TSA. This is the first report indicating that aberrant DNA methylation and histone modifications work together to silence the sFRP2 gene in RCC cells. © 2008 Wiley-Liss, Inc. [source] Vitamin D receptor gene polymorphisms are associated with increased risk and progression of renal cell carcinoma in a Japanese populationINTERNATIONAL JOURNAL OF UROLOGY, Issue 6 2007Wataru Obara Aim: Biological and epidemiologic data suggest that 1 alpha, 25 dihydroxyvitamin D3 (1,25(OH)2D3) levels may influence development of renal cell carcinoma. The vitamin D receptor (VDR) is a crucial mediator for the cellular effects of 1,25(OH)2D3 and additionally interacts with other cell signaling pathways that influence cancer progression. VDR gene polymorphisms may play an important role in risk of incidence for various malignant tumors. This study investigated whether VDR gene polymorphisms were associated with increased risk and prognosis of renal cell carcinoma (RCC) in a Japanese population. Methods: To analyze risk of RCC depending on VDR polymorphism, a case,control association study was performed. The VDR gene polymorphisms at three locations, BsmI, ApaI and TaqI, were genotyped in 135 RCC patients and 150 controls in a Japanese population. Logistic regression models were used to assess the genetic effects on prognosis. Results: Significant differences in the ApaI genotype were observed between RCC patients and controls (,2 = 6.90, P = 0.032). No statistical significant difference was found in the BsmI and TaqI polymorphisms. The frequency of the AA genotype in the ApaI polymorphism was significantly higher in the RCC patients than in the controls (odds ratio, 2.59; 95% confidence intervals, 1.21,5.55; P = 0.012). Multivariate regression analysis showed that the AA genotype was an independent prognostic factor for cause-specific survival (relative risk 3.3; P = 0.038). Conclusion: The AA genotype at the ApaI site of the VDR gene may be a risk of incidence and poor prognosis factor for RCC in the Japanese population. Additional studies with a large sample size and investigation of the functional significance of the ApaI polymorphism in RCC cells are warranted. [source] Involvement of adrenomedullin induced by hypoxia in angiogenesis in human renal cell carcinomaINTERNATIONAL JOURNAL OF UROLOGY, Issue 6 2002Yoshitsugu Fujita Abstract Background: Adrenomedullin (AM) has pluripotent activities and is involved in the regulation of vasomotor tone, cell differentiation and embryogenesis. However, the expression and pathophysiological role of AM has not been determined in human renal cell carcinoma (RCC). Methods: Twenty-six RCC specimens and three cultured human RCC cell lines (A498, SN12C and KPK-13) were analyzed. Expression of AM was determined by immunohistochemistry and reverse transcription,polymerase chain reaction (RT-PCR) analysis. The correlation between AM expression and microvessel count (MVC) in RCC specimens was examined to determine if AM plays a role in tumor angiogenesis. The correlation between the expression of AM and vascular endothelial growth factor (VEGF) was also investigated. Lastly, the effect of hypoxia upon the mRNA expression of AM, VEGF and hypoxia inducible factor-1 (HIF-1) by RCC cell lines was determined. Results: Immunohistochemistry indicated that AM and VEGF were primarily localized in the cytosol of RCC cells. AM and VEGF mRNA were detected in all RCC specimens and cultured RCC cell lines analyzed by RT-PCR. There was a positive correlation between AM mRNA expression and MVC (r = 0.516, P = 0.0062), and between VEGF mRNA expression and MVC (r = 0.485, P = 0.0111). We also observed a positive correlation between AM mRNA expression and VEGF mRNA expression (r = 0.552, P = 0.0029). Hypoxia significantly induced AM and VEGF mRNA expression, although the increase of the AM mRNA level (10.6,26.7 fold) was markedly greater than that of the VEGF mRNA level (1.5,1.9 fold). Conclusion: These results suggest that hypoxia-induced AM plays a part in tumor angiogenesis in conjunction with VEGF and facilitates human RCC growth under hypoxic conditions. [source] Valproic acid blocks adhesion of renal cell carcinoma cells to endothelium and extracellular matrixJOURNAL OF CELLULAR AND MOLECULAR MEDICINE, Issue 8b 2009Jon Jones Abstract Treatment strategies for metastatic renal cell carcinoma (RCC) have been limited due to chemotherapy and radiotherapy resistance. The development of targeted drugs has now opened novel therapeutic options. In the present study, anti-tumoral properties of the histone deacetylase inhibitor valproic acid (VPA) were tested in vitro and in vivo on pre-clinical RCC models. RCC cell lines Caki-1, KTC-26 or A498 were treated with various concentrations of VPA to evaluate tumour cell adhesion to vascular endothelial cells or to immobilized extracellular matrix proteins. In vivo tumour growth was conducted in subcutaneous xenograft mouse models. VPA was also combined with low dosed interferon-, (IFN-,) and the efficacy of the combination therapy, as opposed to VPA monotherapy, was compared. VPA significantly and dose-dependently prevented tumour cell attachment to endothelium or matrix proteins, accompanied by elevated histones H3 and H4 acetylation. VPA altered integrin-, and -, subtype expression, in particular ,3, ,5 and ,3, and blocked integrin-dependent signalling. In vivo, VPA significantly inhibited the growth of Caki-1 in subcutaneous xenografts with the 200 mg/kg being superior to the 400 mg/kg dosing schedule. VPA-IFN-, combination markedly enhanced the effects of VPA on RCC adhesion, and in vivo tumour growth was further reduced by the 400 mg/kg but not by the 200 mg/kg VPA dosing schedule. VPA profoundly blocked the interaction of RCC cells with endothelium and extracellular matrix and reduced tumour growth in vivo. Therefore, VPA should be considered an attractive candidate for clinical trials. [source] Photosensitizing and Radiosensitizing Effects of Hypericin on Human Renal Carcinoma Cells in VitroPHOTOCHEMISTRY & PHOTOBIOLOGY, Issue 1 2008Johannes Theodor Wessels The renal cell carcinoma (RCC) is extremely resistant to chemotherapy and radiotherapy. The prognosis of patients with metastatic RCC still remains poor, the median survival is less than 12 months. Therefore, new therapeutic options are desirable. The aim of this study was to investigate the photosensitizing and radiosensitizing effects of hypericin on human RCC cells in vitro. First the RCC-derived cell lines A498 and ACHN were incubated with different concentrations of hypericin. In vitro uptake and intracellular distribution of hypericin were confirmed by fluorescence microscopy. Subsequently cells were illuminated and irradiated with a dose of 2,8 Gy, respectively. Finally, metabolic activity, apoptosis and clonogenic survival were investigated. Uptake of hypericin was observed for almost all cells. Hypericin treatment combined with illumination led to a 94,97% decrease in metabolic activity and caused apoptosis in nearly 100% of RCC cells. Hypericin enhanced the radiosensitivity of A498 cells in vitro. The clonogenic survival after irradiation was significantly reduced by hypericin treatment. Taken together, the photosensitizing and radiosensitizing effects of hypericin on human RCC cells we found in this investigation could be of clinical relevance, e.g. for radiotherapy and intraoperative photodynamic therapy, respectively. [source] Defective Jak,Stat activation in renal cell carcinoma is associated with interferon-, resistanceCANCER SCIENCE, Issue 8 2007Donghao Shang Chemotherapy is ineffective against metastatic renal cell carcinoma (RCC). Interferon (IFN)-, has become the most common agent used in clinical therapy to overcome this malignant tumor, although a satisfactory response has not been achieved and the mechanism of resistance of RCC to IFN-, remains unclear. The purpose of the present study was to evaluate the susceptibility of RCC cells to IFN-, and clarify the mechanism of IFN-, resistance in RCC. Six RCC cell lines and three types of IFN-, were used, and the expression, activation and effects of transfection of possible proteins or factors reported to be involved in IFN-, signaling were examined to clarify the mechanism of resistance. The results suggest that the resistance of RCC to IFN-, is associated with the lack of Jak1, Tyk2 and Stat1 expression and defective Jak,Stat activation, but not with a lack of IFN-, receptor, suppressors of cytokine signaling induction or other factors examined. Moreover, phosphorylation of Jak,Stat pathway components and reversion of IFN-, resistance in RCC were observed upon transfection with Jak1, Tyk2 or Stat1 vector. These results suggest that restoring the expression of Jak or Stat1 might strikingly increase the susceptibility of RCC to IFN-, and may be a new strategy for improving the response of RCC to IFN-, treatment. The Jak,Stat pathway should therefore be an appropriate target for the treatment of RCC. (Cancer Sci 2007; 98: 1259,1264) [source] Prediction of in vitro response to interferon-, in renal cell carcinoma cell linesCANCER SCIENCE, Issue 4 2007Toru Shimazui We analyzed the correlation between interferon-, (IFN,) response and gene expression profiles to predict IFN, sensitivity and identified key molecules regulating the IFN, response in renal cell carcinoma (RCC) cell lines. To classify eight RCC cell lines of the SKRC series into three subgroups according to IFN, sensitivity, that is, sensitive, resistant and intermediate group, responses to IFN, (300,3000 IU/mL) were quantified by WST-1 assay. Microarray, followed by supervised hierarchical clustering analysis, was applied to selected genes according to IFN, sensitivity. In order to find alteration of expression profiles induced by IFN,, sequential microarray analyses were performed at 3, 6, and 12 h after IFN, treatment of RCC cell lines and mRNA expression level was confirmed using quantitative real time polymerase chain reaction. According to the sequential microarray analysis between IFN,-sensitive and -resistant line, seven genes were selected as candidates for IFN,-sensitivity-related genes in RCC cell lines. Among these seven genes, we further developed a model to predict tumor inhibition with four genes, that is, adipose differentiation-related protein, microphthalmia associated transcription factor, mitochondrial tumor suppressor 1, and troponin T1 using multiple linear regression analysis (coefficient = 0.948, P = 0.0291) and validated the model using other RCC cell lines including six primary cultured RCC cells. The expression levels of the combined selected genes may provide predictive information on the IFN, response in RCC. Furthermore, the IFN, response to RCC might be modulated by regulation of the expression level of these molecules. (Cancer Sci 2007; 98: 529,534) [source] Introduction of Clusterin Gene into Human Renal Cell Carcinoma Cells Enhances Their Resistance to Cytotoxic Chemotherapy through Inhibition of Apoptosis both in vitro and in vivoCANCER SCIENCE, Issue 11 2001Isao Hara Recent studies have revealed the powerful antiapoptotic activity of clusterin in various malignant tumors; however, the significance of clusterin expression in the acquisition of a resistant phenotype against several kinds of treatment in human renal cell carcinoma (RCC) has not been well characterized. We, therefore, transfected the clusterin cDNA into RCC ACHN cells, that scarcely express clusterin protein, to examine whether overexpression of clusterin inhibits chemotherapy-induced apoptosis both in vitro and in vivo. Although no significant differences were observed in the in vitro growth rates between clusterin-transfected ACHN (ACHN/CL) and the vector only-transfected cell line (ACHN/Co), ACHN/CL exhibited high resistance to cisplatin treatment compared with ACHN/Co, with a greater than 5-fold higher IC50 through the inhibition of apoptotic cell death, which was demonstrated by DNA fragmentation analysis and western blotting of PARP protein. Moreover, intravenous administration of cisplatin into athymic nude mice bearing ACHN/CL tumors resulted in 2- to 3-times faster tumor growth compared with ACHN/Co tumors. These findings suggest that clusterin overexpression helps confer a chemoresistant phenotype through inhibition of apoptosis in human RCC cells. [source] | ||||||||||