Calcium-activated nucleotidase 1 silencing inhibits proliferation,migration, and invasion in human clear cell renal cell carcinoma

Calcium-activated nucleotidase 1 (CANT1, belongs to the apyrase family, is widely expressed in various organs. However, the biological function of CANT1 remains poorly explored. In this study, we aimed to investigate the expression profile and functions of CANT1 in clear cell renal cell carcinoma (ccRCC). Our data show that the protein level of CANT1 was significantly higher in tumor tissues than in adjacent normal tissues. CANT1 silencing suppressed cell proliferation, migration, and invasion obviously in 769-P and 786-O cells, arrested cell cycle in S phase and promoted apoptosis in 769-P cells. In conclusion, the present study shows the different expression mode of CANT1 in human ccRCC tumor tissue and adjacent normal tissue, denotes the function of CANT1 in ccRCC cells and provides potential molecular mechanisms and pathways of CANT1 antitumor function in ccRCC.     

MicroRNA-145在肾癌中的临床意义及其分子机制探讨

目的:探讨miRNA-145在肾癌中的临床意义及其分子机制。方法:通过实时定量PCR检测和比较16例肾癌患者的肿瘤组织及癌旁正常肾组织中miRNA-145的表达,并分析miRNA-145的表达水平与肾癌患者病理特征及临床分级的相关性。进一步采用实时定量PCR检测和比较肾癌细胞株786-O、769P及正常肾细胞株HK2中miRNA-145表达量,通过转染miRNA-145 mimics和阴性对照miRNA至769P、786-O肾癌细胞株后观察癌基因(bcl-2、e2f3、cdk6、ccnd1)mRNA的表达。结果:肾癌组织中miRNA-145的表达显著低于癌旁正常肾组织(P0.05),且与肾癌的直径、病理核分级及临床分级呈显著负相关(P0.05)。肾癌细胞株769P、786-O中miRNA-145的表达显著低于正常HK-2肾细胞(P0.05),而转染miRNA-145 mimics的769P、786-O细胞中多个癌基因(bcl-2、e2f3、cdk6、ccnd1)的mRNA表达均较阴性对照组显著降低(P0.05)。结论:MiRNA-145在肾癌中呈低表达,可能通过调控多个癌基因的表达在肾癌的发生发展过程中发挥重要的作用。     

The Tumor Suppressor pVHL Down-regulates Never-in-Mitosis A-related Kinase 8 via Hypoxia-inducible Factors to Maintain Cilia in Human Renal Cancer Cells

NEK8 (never in mitosis gene A (NIMA)-related kinase 8) is involved in cytoskeleton, cilia, and DNA damage response/repair. Abnormal expression and/or dysfunction of NEK8 are related to cancer development and progression. However, the mechanisms that regulate NEK8 are not well declared. We demonstrated here that pVHL may be involved in regulating NEK8. We found that CAK-I cells with wild-type vhl expressed a lower level of NEK8 than the cells loss of vhl, such as 786-O, 769-P, and A-498 cells. Moreover, pVHL overexpression down-regulated the NEK8 protein in 786-O cells, whereas pVHL knockdown up-regulated NEK8 in CAK-I cells. In addition, we found that the positive hypoxia response elements (HREs) are located in the promoter of the nek8 sequence and hypoxia could induce nek8 expression in different cell types. Consistent with this, down-regulation of hypoxia-inducible factors α (HIF-1α or HIF-2α) by isoform-specific siRNA reduced the ability of hypoxia inducing nek8 expression. In vivo, NEK8 and HIF-1α expression were increased in kidneys of rats subjected to an experimental hypoxia model of ischemia and reperfusion. Furthermore, NEK8 siRNA transfection significantly blocked pVHL-knockdown-induced cilia disassembling, through impairing the pVHL-knockdown-up-regulated NEK8 expression. These results support that nek8 may be a novel hypoxia-inducible gene. In conclusion, our findings show that nek8 may be a new HIF target gene and pVHL can down-regulate NEK8 via HIFs to maintain the primary cilia structure in human renal cancer cells.     

Induction of apoptosis by magnolol via the mitochondrial pathway and cell cycle arrest in renal carcinoma cells

Magnolol (Mag), an effective natural compound isolated from the stem bark of Magnolia officinalis, was found to have the potential for antitumor activity by inducing apoptosis in tumor cells. However, the effect of Mag on renal carcinoma cells and its molecular mechanism are unexplored. Our study provided evidence that Mag induced apoptosis in 786-O and OS-RC-2?cell lines via the mitochondrial pathway and cell cycle arrest. In this work, we found that Mag induced morphological changes and inhibited the proliferation of 786-O and OS-RC-2?cells in a dose- and time-dependent manner but exerted no notable inhibitory effects on normal human renal proximal tubular (HK-2) cells. Treatment with Mag suppressed the migration and invasion ability of renal carcinoma cells. Moreover, Mag caused the openness of mPTP, the accumulation of intracellular ROS and decreased △Ψm, leading to mitochondrial dysfunction. However, pretreatment with the antioxidant N-acetyl cysteine (NAC) reversed the apoptosis induced by Mag and decreased the generation of ROS. In addition, the increased proportion of the G1/G0 phase indicated that Mag caused cell cycle arrest. Further analyses suggested that magnolol-induced apoptosis was related to the abnormal expression of p53, Bax, Bcl-2, cytochrome c and caspase activation. Together, the results above revealed that Mag had antitumor effects in renal carcinoma cells via ROS production as well as cell cycle arrest and the apoptotic mitochondrial pathway was suppressed in part by NAC.     

Sphingosine Kinase-1 Activation Causes Acquired Resistance Against Sunitinib in Renal Cell Carcinoma Cells

Multi-target tyrosine kinase inhibitor Sunitinib has been widely used in cancer treatment, including metastatic renal cell carcinoma. However, most patients who initially benefit from Sunitinib develop resistance with extended usage of Sunitinib, which is referred to as “acquired resistance”. The molecular mechanisms contributing to this acquired resistance remain poorly understood. In this present study, we established Sunitinib-resistant cell lines from human renal cell lines (786-O, A498, ACHN and CAKI1) by continuous treatment with Sunitinib to explore the molecular mechanism leading to Sunitinib resistance. We found that PDGFR-β expression in cell seems to be a protective factor against Sunitinib resistance formation. In addition, we found that both SK1 and ERK were activated in Sunitinib-resistance cell lines and SK1 and ERK inhibitors could resensitize Sunitinib-resistant cell lines. In conclusion, our observations suggest that SK1 and ERK activation is a feature of resistant cell lines, which serves as an alternative pathway evading anti-tumor activity of Sunitinib.     

IGFBP3通过癌旁脂肪细胞促进肾癌细胞生长与转移的作用研究

目的:探讨肾透明细胞癌的分泌蛋白IGFBP3对癌旁脂肪细胞分化的作用及通过脂肪细胞促进肾透明癌细胞生长与转移的作用。方法:通过肾细胞癌的基因数据库发现过表达的基因IGFBP3,免疫组化和RT-PCR确认IGFBP3在标本中的表达。RT-PCR和Western Blot检测IGFBP3对脂肪细胞分化成熟特征标志物表达的影响。以过表达IGFBP3的786-O细胞为模型,Western Blot检测IGFBP3的促脂肪细胞分化作用与TGFβ-smad1/5/8及TGFβ-p38MAPK信号通路的关系。将过表达IGFBP3的786-O细胞与脂肪细胞共培养得到条件培养基,通过油红染色检测条件培养的肾癌细胞中脂滴含量,迁移实验和CCK8实验分别检测脂肪细胞对肾癌细胞侵袭性及增殖的影响。结果:相较于正常组,肾癌标本中IGFBP3的表达增加(P=0.017)。IGFBP3使脂肪细胞分化成熟相关标志物PPARγ、PGC1α、c/EBPα、Prdm16、UCP1表达增加。以IGFBP3处理脂肪细胞时,可以增加TGFβ下游蛋白表达水平,30 min后p-smad1/5/8表达增加(P=0.024),60 min后p-p38MAPK表达明显增加(P=0.013)。条件培养后的786-O细胞内的脂滴形成增加(P=0.028),脂肪细胞促进786-O细胞的增殖和迁移能力。结论:IGFBP3是肾透明细胞癌中过度表达的蛋白,能够促进前脂肪细胞分化,其机制主要通过激活TGFβ通路中的smad1/5/8、p38MAPK。成熟的脂肪细胞能够促进肾癌细胞质脂滴形成,并且促进肿瘤的增殖、提高肿瘤的侵袭性。     

LINC00961 restrains cancer progression via modulating epithelial–mesenchymal transition in renal cell carcinoma

Recently, long noncoding RNA have been identified as new gene regulators and prognostic biomarkers in various cancers, including renal cell carcinoma (RCC). The expression and biological roles of LINC00961 have been reported in many human cancers. However, up to date, no study of LINC00961 has been shown in RCC. Currently, we aimed to investigate the function of LINC00961 in RCC progression. Interestingly, we observed that LINC00961 could act as a novel biomarker in predicting the diagnosis of RCC. Then, we found that LINC00961 was greatly downregulated in RCC cell lines (Caki-1, Caki-2, 786-O, A498, and ACHN cells) compared with normal renal cell lines (HK-2 cells). Then, 786-O cells and ACHN cells were infected with LV-LINC00961. As displayed in our current study, LINC00961 overexpression could obviously suppress the proliferation and survival of RCC cells in vitro. In addition, RCC cell apoptosis was greatly induced and cell cycle progression was blocked in G1 phase by upregulation of LINC00961 in 786-O cells and ACHN cells. Subsequently, we found that LV-LINC00961 was able to restrain RCC cell migration and cell invasion capacity. Meanwhile, the messenger RNA and protein expression levels of epithelial–mesenchymal transition (EMT)-associated markers Slug and N-cadherin in RCC cell lines were dramatically inhibited by overexpressing LINC00961. Finally, the in vivo experiment was carried out and we observed that LINC00961 could inhibit RCC development through modulating EMT process. Taken these together, it was indicated in our study that LINC00961 was involved in RCC progression through targeting EMT pathway.     

Hyperthermia Induces Apoptosis of 786-O Cells through Suppressing Ku80 Expression

Hyperthermia as an anticancer method has been paid increasing attention in recent years. Several studies have shown that hyperthermia can kill tumor cells by inducing apoptosis. However, the underlying molecular mechanisms of hyperthermia-induced apoptosis are largely unknown. To investigate the effects and molecular mechanism of hyperthermia on the apoptosis in renal carcinoma 786-O cells, we firstly examined apoptosis and Ku expression in 786-O cell line treated with heat exposure (42°C for 0-4 h). The results showed that hyperthermia induced apoptosis of 786-O cells, and suppressed significantly Ku80 expression, but not Ku70 expression. Next, we knock-down Ku80 in 786-O cells, generating stable cell line 786-O-shKu80, and detected apoptosis, cell survival and cell cycle distribution. Our data showed higher apoptotic rate and lower surviving fraction in the stable cell line 786-O-shKu80 compared with those in control cells, exposed to the same heat stress (42°C for 0-4 h). Moreover, the results also showed suppression of Ku80 led to G2/M phase arrest in the stable cell line 786-O-shKu80 following heat treatment. Together, these findings indicate that Ku80 may play an important role in hyperthermia-induced apoptosis and heat-sensitivity of renal carcinoma cells through influencing the cell cycle distribution.     

Design,synthesis and biological evaluation of 4-aniline-thieno[2,3-d]pyrimidine derivatives as MNK1 inhibitors against renal cell carcinoma and nasopharyngeal carcinoma

MAP Kinase Interacting Serine/Threonine Kinase 1 (MNK1) play important roles in the signaling transduction of MAPK pathways. It is significantly overexpressed in renal clear cell carcinoma and head-neck squamous cell carcinoma tissues in both mRNA and protein levels. Based on the crystallographic structure of MNK1 protein and binding modes analysis of known MNK inhibitors, we have designed and synthesized a series of 4-aniline-thieno[2,3-d]pyrimidine derivatives as potential MNK1 inhibitors. These synthetic compounds are tested in biochemical and cell proliferation assays, and six of them display potent inhibitory capacity against MNK1 kinase and cancer cell lines. Compound 12dj with strongest inhibitory capacity is transferred to molecular mechanism studies, and the results indicated that 12dj remarkably suppresses the phosphorylation of EIF4E, a substrate of MNK1. And the expression levels of MNK1, ERK1/2 and pERK1/2 are not affected by compound 12dj incubation in SUNE-1 and 786-O cells. In summary, our works suggested that these novel 4-aniline-thieno[2,3-d]pyrimidine based MNK1 inhibitors might be attractive lead compounds for targeted therapy of renal cell carcinoma and nasopharyngeal carcinoma.     

Anti-tumor effects of fusion vaccine prepared by renal cell carcinoma 786-O cell line and peripheral blood dendritic cells of healthy volunteers in vitro and in human immune reconstituted SCID mice

Dendritic cells (DC), as professional antigen presenting cells, play the central role in the process of body initiating the anti-tumor immunity, and the study on DC anti-tumor vaccine has become heated in recent years. In this study, we used polyethylene glycol (PEG) to induce renal cell carcinoma (RCC) 786-O cell line fused with peripheral blood DC of healthy volunteers, and discuss the biological characteristics of fusion vaccine and its anti-tumor effects in vitro and in human immune reconstituted SCID mice model of RCC. The study found that PEG could effectively induce cell fusion, and the expressions of CD86 and HLA-DR in fusion vaccine group were significantly up-regulated compared with the DC control group; the secretion of IL-12 was much higher and longer than that of the control; the functions of dendritic cell-tumor fusion vaccine to stimulate the proliferation of allogenic T lymphocytes and to kill RCC786-O cells in vitro were significantly higher than those of the control group, and after the killing, apoptosis body was observed in the target cells; after the injection of fusion vaccine into human immune reconstituted SCID mice model of RCC786-O via vena caudalis, the volume of mice tumor was reduced significantly, proliferation index of tumor cells decreased obviously compared with that of the control group, and more hemorrhage and putrescence focuses presented, accompanying large quantity of lymphocytes soakage. The results of this experimental study shows that fusion vaccine of RCC786-O cell line and DC can significantly stimulate the proliferation of allogenic T cells and specifically inhibit and kill RCC cells in vitro and in vivo, which makes the DC-RCC786-O fusion vaccine a possible new way of effective RCC immunotherapy.     

Ectopic expression of von Hippel-Lindau tumor suppressor induces apoptosis in 786-O renal cell carcinoma cells and regresses tumor growth of 786-O cells in nude mouse

The von Hippel-Lindau (VHL) is a known tumor suppressor that binds to alpha-subunits of hypoxia-inducible factors and induces ubiquitin-mediated degradation of the protein in an oxygen-dependent manner. VHL is also involved in the regulation of tumor angiogenesis, glycolysis, cell cycle regulation, and apoptosis. In the present study, we showed that ectopic expression of VHL induces apoptosis in renal cell carcinoma 786-O cells which contain only the mutant VHL, evidenced by TUNEL assay and DAPI staining. Furthermore, biochemical studies indicated that expression of VHL in 786-O cells results in both PARP and CPP32 cleavage, suggesting that VHL-induced apoptosis in 786-O cells is caspase dependent. Moreover, we also observed that apoptosis induced by ectopic VHL expression was associated with up-regulation of p27 as well as Bax, implicating the roles of these two proteins in VHL-induced apoptosis. The up-regulation of p27 and Bax by VHL was specific since we did not detect any changes in the level of other apoptotic factors including Fas and Bcl2 by the expression of VHL. We next examined the effect of VHL expression on the tumor growth of 786-O renal cell carcinoma cells in nude mouse. The results showed that injection of Ad.VHL adenovirus regresses the tumor growth of 786-O cells in nude mouse. The analysis by TUNEL assay as well as DAPI staining of 786-O tumors injected with Ad.VHL showed clear evidence of apoptosis. These results suggest that ectopic VHL expression induces apoptotic response in 786-O VHL mutant cells both in vitro and in vivo.     

β-Ionone represses renal cell carcinoma progression through activating LKB1/AMPK-triggered autophagy

β-Ionone, the end ring analog of β-carotenoids, has been proven to have an antitumor effect in a variety of cancers. In this study, we investigated the impact of β-ionone on renal cell carcinoma (RCC) cell lines (786-O and ACHN) using colony formation assays, flow cytometry analysis, and western blot analysis. We found that β-ionone effectively inhibited the proliferation of RCC cells in vitro, which was also confirmed in a xenograft model. Moreover, we found that β-ionone could induce autophagy, as indicated by LC3 puncta in 786-O and ACHN cell lines and the expression of LC3 in β-ionone-treated RCC cells. To further explore the underlying mechanism, we assessed liver kinase B1/AMP-activated protein kinase (LKB1/AMPK) signaling pathway activity, and the results showed that β-ionone inhibited the proliferation of RCC cells by inducing autophagy via the LKB1/AMPK signaling pathway. In summary, our findings provide a new therapeutic strategy of β-ionone-induced autophagy in RCC.     

IGFBP-3在真核细胞中的分泌表达及功能分析

将人胰岛素样生长因子结合蛋白3(IGFBP-3)的cDNA片段亚克隆入pSectagA载体, 构建真核分泌型表达载体pSectag-IGFBP3。采用脂质体转染的方法将真核表达载体转染人肾癌786-O细胞, 转染48 h后用免疫印迹法检测IGFBP-3的表达状况; 同时以Annexin V-EGFP/PI染色, 流式细胞仪检测细胞凋亡率, 观察分泌表达的IGFBP-3对宿主细胞的促凋亡作用。转染48 h后, 经Western blotting检测, 在细胞培养上清中有分泌表达的IGFBP-3蛋白。流式细胞技术检测结果表明, 表达产物可直接作用于宿主细胞, 发挥促肿瘤细胞凋亡的作用。由此表明所构建的重组表达质粒pSectag-IGFBP3能在真核细胞水平正常表达并发挥生物学功能, 为进一步探索IGFBP-3的作用机制奠定了基础。     

IGFBP-3在真核细胞中的分泌表达及功能分析

将人胰岛素样生长因子结合蛋白3(IGFBP-3)的cDNA片段亚克隆入pSectagA载体, 构建真核分泌型表达载体pSectag-IGFBP3。采用脂质体转染的方法将真核表达载体转染人肾癌786-O细胞, 转染48 h后用免疫印迹法检测IGFBP-3的表达状况; 同时以Annexin V-EGFP/PI染色, 流式细胞仪检测细胞凋亡率, 观察分泌表达的IGFBP-3对宿主细胞的促凋亡作用。转染48 h后, 经Western blotting检测, 在细胞培养上清中有分泌表达的IGFBP-3蛋白。流式细胞技术检测结果表明, 表达产物可直接作用于宿主细胞, 发挥促肿瘤细胞凋亡的作用。由此表明所构建的重组表达质粒pSectag-IGFBP3能在真核细胞水平正常表达并发挥生物学功能, 为进一步探索IGFBP-3的作用机制奠定了基础。     

SIRT3过表达通过调控细胞代谢转换抑制肾肿瘤细胞的增殖

目的:研究SIRT3对肾透明细胞癌(clear cell renal cell carcinoma, ccRCC)769-P细胞增殖和抗氧化能力的影响,并进一步探究其作用机制。方法:在769-P细胞的基础上构建SIRT3过表达稳转细胞系;利用CCK-8试剂检测769-P SIRT3过表达细胞的增殖速度;利用CellROX~Deep Red染料并结合流式细胞分析检测SIRT3过表达对769-P细胞中ROS水平的影响;利用定量蛋白质组学和代谢组学的方法,探究SIRT3对769-P细胞的作用机制。结果:CCK-8实验结果表明,769-P SIRT3过表达细胞的生长速度与对照细胞相比下降了约48%;定量蛋白质组学分析显示,769-P SIRT3过表达细胞中ALDOA、ALDOA、ENO2、PKM、LDHA、LDHB表达量下调约0.4至0.7倍,SDHB和CS上调约1.3倍;代谢组学分析显示,PEP、pyruvic acid、lactate、carnitine水平下降约0.4至0.7倍,isocitric acid和acetyl-CoA水平升高分别约1.3和2.8倍;分析还显示SIRT3过表达上调SOD2、TXN、GPX4和GLRX5的表达量约1.3至2倍,降低ROS水平约40%,增强细胞对过氧化氢的耐受力。结论:SIRT3过表达引起769-P细胞的代谢转换,从而抑制其增殖;且上调769-P细胞中抗氧化酶的表达,降低ROS水平,增强细胞的抗氧化能力。     

siRNA下调EZH2 基因对肾癌细胞系769-P增殖的影响

目的：运用小干扰RNA下调果蝇zeste 基因增强子人类同源物（enhancer of zeste homolog 2,EZH2）在肾癌细胞系769-P 中 的表达,明确其对肾癌细胞增殖的影响。方法：将处于对数生长期769-P 细胞分为实验组（experiment group）、阴性对照组(negative group)、空白对照组（blank group）,合成靶向EZH2 基因的小干扰RNA片段（EZH2-siRNA）和无效序列片段后,通过脂质体介导分 别转染至实理组和阴性对照组,空白对照组未做任何处理。以qRealtime-PCR 检测EZH2 基因mRNA 水平的变化情况,以MTT 法检测各组细胞增殖变化;流式细胞术（FCM）检测转染后细胞周期变化情况。结果：实理组中EZH2 在mRNA 表达水平明显受 抑制;MTT实验中第4 天始,实验组中769-P 细胞的增殖能力开始受抑制,第5 天时实验组细胞抑制更明显,与阴性对照组和空 白组比较差异有统计学意义（P < 0.05）。siRNA 转染后实验组中G0/G1 期细胞比例明显增多(81.32± 3.14)%,与阴性对照组 (44.13± 1.52)%和空白对照组(45.71± 2.32)%差异有统计学意义。结论：EZH2-siRNA 可有效下调并抑制肾癌细胞769-P的增殖, EZH2在肾癌的发生、发展中发挥了重要作用,为下一步研究肾癌基因治疗提供了理论支持。     

siRNA下调EZH2基因对肾癌细胞系769-P增殖的影响

目的：运用小干扰RNA下调果蝇zeste基因增强子人类同源物（enhancer ofzeste homolog 2,EZH2）在肾癌细胞系769-P中的表达,明确其对肾癌细胞增殖的影响。方法：将处于对数生长期769-P细胞分为实验组（experiment group）、阴性对照组（negative group）、空白对照组（blank group）,合成靶向EZH2基因的小干扰RNA片段（EZH2-siRNA）和无效序列片段后,通过脂质体介导分别转染至实理组和阴性对照组,空白对照组未做任何处理。以qRealtime-PCR检测EZH2基因mRNA水平的变化情况,以MTT法检测各组细胞增殖变化;流式细胞术（FCM）检测转染后细胞周期变化情况。结果：实理组中EZH2在mRNA表达水平明显受抑制;MTT实验中第4天始,实验组中769-P细胞的增殖能力开始受抑制,第5天时实验组细胞抑制更明显,与阴性对照组和空白组比较差异有统计学意义（P〈0.05）。siRNA转染后实验组中G0/G1期细胞比例明显增多（81.32±3.14）%,与阴性对照组（44.13±1.52）%和空白对照组（45.71±2.32）%差异有统计学意义。结论：EZH2-siRNA可有效下调并抑制肾癌细胞769-P的增殖,EZH2在肾癌的发生、发展中发挥了重要作用,为下一步研究肾癌基因治疗提供了理论支持。     

Effects of homocysteine and its related compounds on oxygen consumption of the rat heart tissue homogenate: the role of different gasotransmitters

Accumulating evidence indicates that microRNAs are implicated in tumor initiation and progression through negatively regulating oncogenes or tumor suppressor genes. In the present study, we report that the expression of miR-200a was significantly lower in renal cell carcinoma (RCC) specimens and RCC cell lines. Restoration of miR-200a suppressed cell growth, arrested cell cycle progression, and promoted cell apoptosis in RCC cell lines. We next used qRT-PCR array technology to identify Sirtuin 1 (SIRT1) as one of the downregulated proteins during miR-200a overexpression in 786-O cells. Following a further assay by luciferase reporter system, SIRT1 was validated as a direct target of miR-200a. Moreover, siRNA-mediated knockdown of SIRT1 could partially phenocopy the effects of miR-200a overexpression. In contrast, overexpression of truncated SIRT1 (without an endogenous 3′-UTR) could rescue the effect of miR-200a overexpression on 786-O cells, which suggested that SIRT1 3′-UTR is targeted by miR-200a specifically. These observations provide further evidence for a critical tumor-suppressive role of the miR-200a in RCC in addition to identifying a novel regulatory mechanism, which may contribute to SIRT1 upregulation in RCC.     

Identification of TGF-β-activated kinase 1 as a possible novel target for renal cell carcinoma intervention

Renal cell carcinoma (RCC) is common renal malignancy within poor prognosis. TGF-β-activated kinase 1 (TAK1) plays vital roles in cell survival, apoptosis-resistance and carcinogenesis through regulating nuclear factor-κB (NF-κB) and other cancer-related pathways. Here we found that TAK1 inhibitors (LYTAK1, 5Z-7-oxozeanol (5Z) and NG-25) suppressed NF-κB activation and RCC cell (786-O and A489 lines) survival. TAK1 inhibitors induced apoptotic cytotoxicity against RCC cells, which was largely inhibited by the broad or specific caspase inhibitors. Further, shRNA-mediated partial depletion of TAK1 reduced 786-O cell viability whiling activating apoptosis. Significantly, TAK1 was over-expressed in human RCC tissues, and its level was correlated with phosphorylated NF-κB. Finally, kinase inhibition or genetic depletion of TAK1 enhanced the activity of vinblastine sulfate (VLB) in RCC cells. Together, these results suggest that TAK1 may be an important oncogene or an effective target for RCC intervention.