Renal Cell Carcinoma Carcinogenesis Research Articles

Regulatory Network of Two Tumor-Suppressive Noncoding RNAs Interferes with the Growth and Metastasis of Renal Cell Carcinoma

Noncoding RNAs (ncRNAs) such as microRNAs (miRNAs) and long ncRNAs (lncRNAs) have been shown to function as pivotal regulators in the carcinogenesis of renal cell carcinoma (RCC). However, the functions and underlying mechanisms of most ncRNAs in RCC are still elusive, and the crosstalks of different layers of ncRNAs are seldom reported. Here we showed that miR-124 and maternally expressed gene 3 (MEG3) were both significantly reduced in RCC, and combined expression of miR-124 and MEG3 emerged as an independent prognostic factor in our RCC cohort. Overexpression of miR-124 or MEG3 inhibited cell proliferation, migration, and invasion in vitro, and restrained tumor growth in vivo. EZH2 knockdown induced the epigenetic silencing of miR-124 and MEG3 expression by H3K27me3. Besides, miR-124 directly targeted the TET1 transcript, and then the interaction resulted in the upregulation of MEG3. Furthermore, we demonstrated that MEG3 induced p53 protein accumulation, whereas p53 was a positive transcriptional regulator of the miR-124. In addition, tumor-suppressive PTPN11 was identified as a direct target of miR-124, as well as the MEG3- and p53-regulated gene. Our study identifies three crosstalks between miR-124 and MEG3, which provide a plausible link for these two ncRNAs in RCC. Both ncRNAs exert important antitumor effects in RCC pathogenesis and might serve as prognostic biomarkers and molecular therapeutic targets.

Simvastatin reduces the carcinogenic effect of 3-methylcholanthrene in renal epithelial cells through histone deacetylase 1 inhibition and RhoA reactivation

The therapeutic effects of simvastatin for renal cell carcinoma (RCC) are controversial. In this study, the effects of simvastatin on the carcinogenic properties of 3-methylcholanthrene (3MC; an aryl-hydrocarbon receptor [AhR] agonist) in human renal epithelial cells (hRECs) were investigated. We exposed in vitro and in vivo models to 3MC to induce RCC onset. 3MC upregulated the epithelial–mesenchymal transition (EMT) and tumor biomarkers; the models exhibited the reciprocal expression of histone deacetylase 1 (HDAC1) and RhoA, namely increased HDAC1 and decreased RhoA expression, through hypoxia-inducible-factor (HIF)- and AhR-dependent mechanisms. In addition to inducing EMT biomarkers, 3MC decreased von Hippel–Lindau protein levels (a risk factor for RCC) and increased CD44 expression in hRECs, which were reversed by digoxin (a HIF inhibitor) and HDAC inhibitors (suberoylanilide hydroxamic acid and trichostatin A [TSA]). Simvastatin abolished the detrimental effects of 3MC by reducing HDAC1 expression, with resulting RhoA upregulation, and reactivating RhoA in vitro and in vivo. Notably, the protective effects of simvastatin were negated by an HDAC activator (ITSA) through TSA suppression. The crucial role of RhoA in RCC carcinogenesis was verified by the overexpression of constitutively active RhoA. Collectively, these results demonstrate that simvastatin restores RhoA function through HDAC1 inhibition; therefore, simvastatin might serve as adjunct therapy for RCC induced by 3MC.

The E2F1-miR-520/372/373-SPOP Axis Modulates Progression of Renal Carcinoma.

: Although renal cell carcinoma (RCC) is the most malignant urologic cancer, its pathogenesis remains unclear, and effective treatments for advanced RCC are still lacking. Here, we report that a novel E2F1-miR-520/372/373-SPOP axis controls RCC carcinogenesis. Speckle-type POZ protein (SPOP) was upregulated in over 90% of RCC tissues, whereas the miR-520/372/373 family was downregulated and correlated inversely with SPOP protein levels in RCC tissues. The miR-520/372/373 family targeted the SPOP 3'-UTR and suppressed SPOP protein expression, leading to elevation of PTEN and DUSP7 levels and, consequently, decreased proliferation, invasion/migration, and metastasis of RCC cells in vitro and in vivo. Tail-vein delivery of therapeutic miR-520/372/373 family significantly decreased both tumor size and lung metastasis ratio in mice bearing orthotopic xenograft tumors. Decreased expression of miR-520/372/373 family was mediated by transcription factor E2F1. In conclusion, our results demonstrate that the E2F1-miR-520/372/373-SPOP axis functions as a key signaling pathway in RCC progression and metastasis and represents a promising opportunity for targeted therapies. SIGNIFICANCE: These findings show that the E2F1-miR-520/372/373 family-SPOP axis promotes RCC progression, thereby contributing to our understanding of RCC pathogenesis and unveiling new avenues for more effective targeted therapies.

Role of miR-486-5p in regulating renal cell carcinoma cell proliferation and apoptosis via TGF-β-activated kinase 1.

Renal cell carcinoma (RCC) is a common kidney tumor in adults. The role of miR-486-5p in RCC is unknown. The aim of our study was to identify new targets regulated by miR-486-5p in RCC, to obtain a deeper insight into the network and to better understand the role of these microRNAs and their targets in carcinogenesis of RCC. We performed a series of tests and found consistently lower expression levels of miR-486-5p in kidney cancer cells. Restoration of miR-486-5p expression in RCC cells could lead to the suppression of cell proliferation and the increase of cell apoptosis. Further studies demonstrated that TGF-β-activated kinase 1 was a target gene of miR-486-5p in kidney cancer cells. It was also shown that C-C motif chemokine ligand 2(CCL2) from tumor-associated macrophages downregulated miR-486-5p expression, and miR-486-5p inhibited RCC cell proliferation and apoptosis resistance induced by CCL2. The study demonstrates that there are potential diagnosis and therapy values of miR-486-5p in RCC.

Karyopherin Alpha 2 Is an Adverse Prognostic Factor in Clear-Cell and Papillary Renal-Cell Carcinoma.

Karyopherin α2 (KPNA2) is involved in the nucleocytoplasmic transport system and is functionally involved in the pathogenesis of various solid tumors by the translocation of cancer associated cargo proteins. However, the role of KPNA2 in renal-cell carcinoma (RCC) is still unknown. The aim of the present study was to investigate the protein expression of KPNA2 in cancerous and healthy renal tissues to evaluate its prognostic value in RCC. We assessed KPNA2 protein expression via immunohistochemistry in a well-characterized cohort of 240 RCC patients by using a quantitative image analysis software. In addition, we analyzed publicly available gene expression data from The Cancer Genome Atlas (TCGA). A subgroup of clear-cell RCC (ccRCC) showed elevated protein expression levels of KPNA2. Most remarkably, we detected a correlation between high KPNA2 protein expression and shorter overall survival times as well as higher tumor stage and International Society of Urologic Pathology grade in ccRCC. However, the prognostic value of KPNA2 was not confirmed by multivariate Cox regression analysis when tested together with strong prognostic factors like tumor stage, lymph node metastasis, International Society of Urologic Pathology grade, and resection status. The results of the TCGA gene expression data analysis confirmed the prognostic value of KPNA2 in ccRCC. Additionally, KPNA2 expression was identified as an adverse factor in papillary RCC at the transcript level. KPNA2 appears to be involved in the carcinogenesis of RCC and functions as a novel prognostic indicator.

Estrogen affects cell growth and IGF-1 receptor expression in renal cell carcinoma.

PurposeBoth obesity and gender are important etiological factors in renal cell carcinoma (RCC) development, suggesting a pivotal role of sex hormone signaling pathway and insulin-like growth factor (IGF) family in RCC carcinogenesis. Here, we aimed to investigate the effect of estrogen on RCC growth and the possible interaction between estrogen/estrogen receptor (ER) signaling pathway and the IGF axis.MethodsER-α and ER-β were detected in four human RCC cell lines. Cells were treated with 17β-estradiol (E2), and cell proliferation was determined using the cell counting kit-8 assay. Using siRNA, ER-β was downregulated in RCC cells and the effect of E2 on cell growth and IGF-1 receptor (IGF-1R) expression was examined.ResultsE2 inhibited 786-O cell but not A498 cell growth significantly. After the downregulation of ER-β, E2 showed no obvious inhibitory role in 786-O cells. E2 stimulation increased the expression of IGF-1R in 786-O cells. Downregulation of ER-β, as well as fulvestrant, attenuated the stimulatory effect of E2 on IGF-1R expression.ConclusionOur results revealed that estrogen induced RCC growth inhibition via an ER-β-dependent pathway. Estrogen also upregulated the expression of IGF-1R, suggesting a link between estrogen/ER and IGF axis.

Biomarkers and new therapeutic targets in renal cell carcinoma.

Renal Cell Carcinoma (RCC) is the most common malignancy in adult kidneys. The American Cancer Society estimated 62,700 new cases and 14,240 deaths in 2018. Although early detection has improved in recent years, the treatment remains a challenge and reliable biomarkers for poor outcomes become necessary for the prevention of metastases and improve the quality of patients' life during and after treatment. Then, the current status of the search for new RCC biomarkers was discussed, as well as the latest discoveries in the RCC risk and metastatic treatment were discussed in this review. Extensive research was carried out in the online databases and full-free text articles published in the last 5 years, or more when convenient, were evaluated. Articles were included that addressed the proposed theme and were published in the English language. The present state of knowledge on biomarkers for RCC carcinogenesis and progression is still much to be understood about RCC risk factors and molecular pathways resulting in metastatic progression. Newest RCC target therapies were discussed, mainly in relation to immunological therapy, and vaccines that have been tested in numerous trials with different cancer types. The development of targeted therapies has revolutionized the treatment of advanced and metastatic cancers or non-responder patients. Combined therapy between classical chemotherapy and adjuvant immunotherapies has been modifying the cancer patients prognosis and bringing the hope of a cure in many cases.

Cyanidin Curtails Renal Cell Carcinoma Tumorigenesis

Background/Aims: Cyanidin is an anthocyanin found in many foods. Although its variable antioxidant levels are well-documented, little is known about its effects on renal cell carcinoma (RCC) tumorigenesis. This study, therefore, investigated the effects of cyanidin on the proliferation, migration, and invasion of renal cell carcinoma lines and demonstrated, for the first time, significant inhibitory effects of cyanidin on RCC tumorigenesis. Methods: RCC cells were treated with different doses of cyanidin and the effects were tested by Cell Counting Kit-8 reagent, clone formation assay, transwell assay, and flow cytometry. Moreover, the cyanidin-mediated mechanism that curtailed tumorigenesis was analyzed by RNA sequencing (RNA-seq). Sequencing data from The Cancer Genome Atlas (TCGA) were used to compare the expression of both early growth response protein 1 (EGR1) and selenoprotein W (SEPW1) in RCC and tumor-free adjacent normal tissue samples. Real-time PCR (RT-PCR) and/or western blot were used to assess the expression of E-cadherin, cleaved-caspase3, Bcl2, p62, and ATG4. Results: We found significantly greater induction of cell-cycle arrest, apoptosis, and suppression of RCC cell invasion and migration at concentrations of 25 µM and 100 µM than at a concentration of 50 µM. It was also discovered, first through RNA-seq then confirmed by RT-PCR, that cyanidin (100 µM) inhibited RCC carcinogenesis through EGR1 and SEPW1. TCGA data indicated that the expression level of EGR1 was lower and that of SEPW1 was higher in RCC tumor tissue than in normal tissues. Moreover, western blot and/or RT-PCR indicated that cleaved-caspase3 was enhanced and E-cadherin was inhibited by cyanidin treatment. Furthermore, western blot and RT-PCR also showed regulation of p62 and ATG4, which are associated with autophagy. Cyanidin in vivo significantly inhibited the growth of xenografts in nude mice. Conclusions: The results of this study showed the therapeutic potential of cyanidin for the treatment of RCC and the prevention of recurrence and metastasis.

Differential expression of the sirtuin family in renal cell carcinoma: Aspects of carcinogenesis and prognostic significance

ObjectivesSirtuins (1–7) are evolutionarily conserved NAD-dependent deacetylases that play an important role in carcinogenesis. However, their role in renal cell carcinoma (RCC) remains unclear. The objective of the present study was to examine the role of SIRTs in RCC carcinogenesis and prognosis. Materials and methodsParaffin-embedded specimens from 102 patients who underwent extirpative renal surgeries for renal masses between January 2004 and December 2010 were examined. SIRT expression was compared between RCC and adjacent normal kidney tissues by immunohistochemical staining. Survival differences and cancer-specific survival were analyzed with the Kaplan-Meier log-rank test and univariate and multivariate Cox regression analyses, respectively. ResultsSIRT1, SIRT3, and SIRT6 expression was significantly lower in RCC than in normal tissues (P = 0.001, P = 0.006, and P = 0.033, respectively), whereas the expression of other SIRT proteins did not differ significantly between the 2 tissues. SIRT3 expression was significantly associated with longer cancer-specific survival (HR = 0.133, P = 0.047), after adjusting for age, T stage, Fuhrman grade, Karnofsky performance status, and distant metastases. Kaplan-Meier analysis showed that patients with high-SIRT3 expression had relatively better survival than those with low-SIRT3 expression (P = 0.046, log-rank test). ConclusionsOur results provide preliminary evidence suggesting that SIRT1, SIRT3, and SIRT6 function as tumor suppressors in RCC. In particular, SIRT3 seems to have a favorable influence on the survival of patients with clear cell RCC.

PDZK1 inhibits the development and progression of renal cell carcinoma by suppression of SHP-1 phosphorylation.

Renal cell carcinoma (RCC) is one of the most aggressive urologic cancers, however, the mechanism on supporting RCC carcinogenesis is still not clear. By using gene expression profile analysis and functional clustering, PDZ domain-containing 1 (PDZK1) was revealed to be downregulated in human clear cell renal cell carcinoma (ccRCC) samples, which was also verified in several independent public ccRCC data sets. Using PDZK1 overexpression and knockdown models in ccRCC cell lines, we demonstrated that PDZK1 inhibited cell proliferation, cell cycle G1/S phase transition, cell migration and invasion, indicating a tumor-suppressor role in the development and progression of ccRCC. Our study further demonstrated that PDZK1 inhibited cell proliferation and migration of ccRCC via targeting SHP-1. PDZK1 was further identified to suppress cell proliferation by blocking SHP-1 phosphorylation at Tyr536 via inhibition of the association between SHP-1 and PLCβ3, and then retarding Akt phosphorylation and promoting STAT5 phosphorylation in ccRCC cells. Moreover, the inhibitive effects of PDZK1 on SHP-1 phosphorylation and the tumor growth were verified in vivo by xenograft tumor studies. Accordingly, PDZK1 expression was negatively correlated with SHP-1 activation and phosphorylation, advanced pathologic stage, tumor weight and size, and prognosis of ccRCC patients. These findings have provided first lines of evidences that PDZK1 expression is negatively correlated with SHP-1 activation and poor clinical outcomes in ccRCC. PDZK1 was identified as a novel tumor suppressor in ccRCC by negating SHP-1 activity.

Clinical significance of p16INK4A and p14ARF promoter methylation in renal cell carcinoma: a meta-analysis.

The inactivation of p16INK4A and p14ARF via promoter methylation has been investigated in various cancers. However, the clinical effects of p16INK4A and p14ARF promoter methylation on renal cell carcinoma (RCC) remain to be clarified. The pooled data were calculated and summarized. Finally, an investigation of 14 eligible studies with 1231 RCC patients and 689 control patients was performed. Methylated p16INK4A and p14ARF were observed to be significantly higher in RCC than in control subjects without malignancies (OR = 2.77, P = 0.005; OR = 11.73, P < 0.001, respectively). Methylated p16INK4A was significantly associated with the risk of RCC in the tissue subgroup, but not in the serum and urine subgroups. Methylated p16INK4A was significantly associated with tumor size. We did not find that p16INK4A promoter methylation was associated with sex, tumor grade, lymph node status, and tumor histology. Methylated p14ARF was significantly correlated with sex and tumor histology. Three studies reported that p16INK4A methylation was not significantly correlated with the prognosis of RCC. The results suggested that p16INK4A and p14ARF promoter methylation may be correlated with the carcinogenesis of RCC, and that methylated p14ARF, especially, can be a major susceptibility gene. We also found the different clinicopathological significance of 16INK4A and p14ARF in RCC. Additional studies with sufficient data are essential to further evaluate the clinical features and prognostic effect of p16INK4A and p14ARF promoter methylation in RCC.

Expression and clinical significance of CD147 in renal cell carcinoma: a meta-analysis.

ObjectiveTo assess clinical significance of CD147 in renal cell carcinoma.MethodsCollect case-control studies which focus on CD147's expression in renal cell carcinoma. Trails were retrieved from CBM, CNKI, Wan-fang database, PubMed, Cochrane Library and Embase. According to the inclusion and exclusion criteria, data extraction and quality assessment were done by two researchers independently, and outcomes were pooled with Revman5.3 and STATA14.0.ResultsA total of 11 studies were confirmed, among which renal cell carcinoma 887 cases, non-cancer 505cases. As for the positive rate of CD147, there are statistical differences among survival, renal cell carcinoma tissue vs. non-cancer tissues [OR= 8.19, P= 0.0002], with vs. without lymph node metastases [OR= 6.52, P= 0.001], clinical stage III~IV vs. II~I [OR= 4.07, P< 0.00001], histopathological stage III~IV vs. II [OR= 3.01, P= 0.002], histopathological stage III~IV vs. I [OR= 7.50, P< 0.00001], tumor size [OR= 5.01, P= 0.0007]. No significant difference was tested among different age, gender, histological types and Position of cancer.ConclusionAs shown in our results, CD 147 may participate the whole course of carcinogenesis of renal cell carcinoma, which might be valuable for the diagnosis, treatment and prognosis.

Cellular effects induced by 17-β-estradiol to reduce the survival of renal cell carcinoma cells.

BackgroundRenal cell carcinoma (RCC) is an adult malignancy with 2:1 men-to-women ratio, which implies the possible role of sex hormones in RCC carcinogenesis. One of the predominant sex hormones in women before menopause, 17-β-estradiol (or E2), may regulate RCC growth by cellular mechanisms that are still not fully understood.MethodsThe expression levels of E2 receptors (ER1 and ER2) were determined in different RCC cell lines. The DNA damage response induced by E2 was determined by a DNA double-strand break marker γH2AX. To study the possible effect of E2 on oxidative stress response, RCC cells were stained with 2,7-dichlorofluorescein diacetate and analyzed by flow cytometry. Upregulation of nuclear factor (erythroid-derived 2)-like 2 (Nrf2) ser40 phosphorylation in response to oxidative stress was detected by immunoblotting. Finally, annexin V/propidium iodide (PI) double staining assay was used to determine E2-induced cellular apoptosis.ResultsVariable expression of ER1 and ER2 were found in the RCC cell lines studied (786-O, A498, and ACHN), in which ACHN and A498 showed highest and lowest ER expression, respectively. In A498 cells, E2 induced DNA double-strand breaks with positive staining of γH2AX. On the other hand, the level of reactive oxidative species were elevated in ACHN cells after E2 treatment. The E2-induced oxidative stress also induced the Ser40 phosphorylation and nuclear translocation of Nrf2. Finally, we also demonstrated that E2 induced apoptosis as revealed by annexin V/PI double staining.ConclusionsIn this study, we demonstrated the cellular effects of E2 on DNA repair, ROS production as well as Nrf2 activation, and apoptosis in RCC cell lines. Together these cellular alterations may contribute to the reduced viability of RCC cells following E2 treatment.

Carcinogenesis of renal cell carcinoma reflected in HLA ligands: A novel approach for synergistic peptide vaccination design

ABSTRACTDespite recent advances in immunotherapy of renal cell carcinoma (RCC), peptide vaccination strategies still lack an approach for personalized peptide vaccination that takes intra- and inter-tumoral heterogeneity and biological characteristics into account. In this study, we use an immunoprecipitation and mass spectrometry-based approach supplemented by network analysis of HLA ligands to target this goal. By analyzing HLA-presented peptides for HLA class I and II of 11 malignant and 6 non-malignant kidney tissue samples, more than 2,700 peptides and 1,600 corresponding source proteins were identified. A high overlap with HLA ligands derived from peripheral blood mononuclear cells (PBMCs) was detected most likely due to tumor-infiltrating inflammatory cells and therefore excluded from network analysis. Subsequent biological function analysis of HLA ligands by the GeneMANIA online platform showed enrichment for well established, but also novel, pathways and biological processes involved in carcinogenesis of RCC almost exclusively in malignant tissue samples. By exploring source proteins involved in these overrepresented pathways, we verified various known tumor-associated antigens (TAAs) for RCC (e.g., CA9, EGLN3, IGFBP3, MMP7, PAX2, VEGFA, or EGFR) but could also detect novel TAAs for RCC (e.g., PLOD2, LOX, ENPEP, or TGFBI). Some of these new TAAs had already been shown to elicit a T cell response in cancer patients. Thus, network analysis of HLA ligands provided a new platform for implementing personalized, multipeptide vaccines with potentially synergistic antitumor effects.

Elevated expression of KIF18A enhances cell proliferation and predicts poor survival in human clear cell renal carcinoma

The function of kinesin family member 18A (KIF18A) in human renal cell carcinoma (RCC) is unclear. The purpose of the current study was to determine the expression and prognostic significance of KIF18A in RCC. Specimens from 273 RCC patients undergoing nephrectomies were studied. Expression of KIF18A mRNA was examined by reverse transcription-polymerase chain reaction (RT-PCR) or quantitative PCR, and the expression of KIF18A protein was examined by immunohistochemistry and western blotting. The expression of KIF18A in clear-cell RCC cell lines was decreased using small interfering RNA targeting KIF18A, and increased by transfection with KIF18A cDNA. The proliferative ability of RCC cells in vitro and in vivo was detected by WST-1 assay and an animal xenograft model with BALB/c nude mice, respectively. The association between KIF18A expression and overall survival was calculated using Kaplan-Meier analysis. The results showed that KIF18A expression was significantly increased in RCC tissues compared with normal kidney tissues. The level of KIF18A expression was significantly associated with tumor stage, histological grade, metastasis and tumor size. Moreover, KIF18A increased the proliferation of RCC cells in vitro and in vivo. KIF18A expression was upregulated in RCC and enhanced the proliferation of RCC cells. Therefore, it appears that KIF18A plays a key role in the carcinogenesis and progression of RCC, and is a novel candidate prognostic marker for RCC patients. Furthermore, silencing KIF18A expression may serve as a new therapeutic strategy against RCC.

The Microphthalmia-Associated Transcription Factor p.E318K Mutation Does Not Play a Major Role in Sporadic Renal Cell Tumors from Caucasian Patients

Objective: The transcription factor MITF (microphthalmia-associated transcription factor) is known to induce expression of hypoxia-inducible factor (HIF1-α), which is involved in renal carcinogenesis. The MITF p.E318K mutation leads to deficient SUMOylation of MITF, resulting in enhanced activation of its target genes. A case-control study on melanoma patients who coincidentally were affected by renal cell carcinoma (RCC) has revealed an elevated risk for mutation carriers to be affected by one or both of these malignancies, suggesting a possible role for MITF p.E318K in renal carcinogenesis. The same study described an MITF mutation frequency of 1.5% in a small cohort of sporadic RCC, but comprehensive data on sporadic renal cell tumors are missing. We therefore tested a large cohort of sporadic renal tumors for MITF p.E318K mutation status. Methods: Genomic DNA was extracted from 426 formalin-fixed, paraffin-embedded sporadic renal tumors that had been graded according to the 2004 WHO classification of renal tumors and staged according to the 2002 TNM classification. The tumor cohort was enriched with papillary and chromophobe RCC, and also contained benign oncocytomas. DNA was tested for MITF p.E318K by pyrosequencing. Results: Of 403 analyzable tumors, 402 renal tumors were wild-type ones, and only 1 case showed the MITF p.E318K mutation. This tumor was a clear-cell RCC (pT3b N0 M0 G3 according to the TNM classification 2002). The affected patient was male, 61 years old, and had no known coexisting malignancies. Conclusion: The MITF p.E318K mutation does not appear to play a major role in sporadic RCC carcinogenesis, but is possibly restricted to a rare subpopulation of inherited RCC.

The Clinicopathological Significance of Epigenetic Silencing of VHL Promoter and Renal Cell Carcinoma: A Meta-Analysis

Background/Aims: Von Hippel-Lindau gene (VHL) has been reported as a tumor-suppressor gene in some cancers. However, the association between VHL promoter hypermethylation and renal cell carcinoma (RCC) remains to be clarified. We are the first to systematically integrate published papers to assess the role of hypermethylated VHL in RCC. Methods: The potential relevant papers were searched via PubMed, Embase, EBSCO, CNKI, and Wanfang databases. The overall odds ratio (OR) and corresponding 95% confidence interval (95% CI) were calculated to evaluate the relationship between VHL promoter hypermethylation and RCC. Results: Finally, a total of 1,998 RCC patients and 294 controls from 13 eligible articles were included in this meta-analysis. Under the fixed-effects model, the pooled OR from seven studies including 596 RCC and 294 nonmalignant samples showed that VHL promoter hypermethylation was significantly higher in cancer than in controls (OR = 7.93, 95% CI = 2.84- 22.15, P < 0.001). Subgroup analysis based on ethnic population and testing method revealed that hypermethylated VHL had a significantly similar OR value in different races and detection methodologies. No significant association was found between hypermethylated VHL and tumor grade, tumor stage, tumor size, histological types, and lymph node status in cancer (all P > 0.05). In the current study, there was no evidence of publication bias as determined by Egger's test (all P > 0.05). Conclusions: In the investigated patients, VHL promoter hypermethylation, which may play an important role in carcinogenesis of RCC, is significantly associated with an increased risk of RCC. However, VHL promoter hypermethylation is not correlated with specific clinicopathological characteristics. Additional future studies are needed to confirm our results.

FH535 inhibited metastasis of pancreatic cancer cells

Renal cell carcinoma is the most common highly metastatic kidney malignancy. Adhesion has a crucial role in the metastatic process. TGF (transforming growth factor)-β1 is a pleiotropic cytokine that influences cancerous transformation. We hypothesized that 1) changes in the expression of adhesion related genes may influence survival rate of patients with renal cell carcinoma and 2) TGF-β1 may contribute to changed expression of adhesion related genes.Two-step quantitative real-time polymerase chain reaction arrays were used to analyze the expression of adhesion related genes in 77 tumors and matched pair controls. The prognostic significance of genes was evaluated in TCGA (The Cancer Genome Atlas) data on 468 patients with renal cell carcinoma. Quantitative real-time polymerase chain reaction and Western blot were applied for TGF-β1 analysis. TGF-β1 mediated regulation of gene expression was analyzed by TGF-β1 supplementation of Caki-2 cells and quantitative real-time polymerase chain reaction.The expression of 19 genes related to adhesion and extracellular matrix remodeling was statistically significantly disturbed in renal cell carcinoma compared with controls. The 10-gene expression signature (COL1A1, COL5A1, COL11A1, FN1, ICAM1, ITGAL, ITGAM, ITGB2, THBS2 and TIMP1) correlated with poor survival (HR 2.85, p = 5.7e−10). TGF-β1 expression was 22 times higher in renal cell carcinoma than in controls (p <0.0001). TGF-β1 induced expression of TGFBI, COL1A1, COL5A1, COL8A1, FN1, ITGA5, ITGAM and TIMP1 in a renal cell carcinoma derived cell line.Disturbed expression of genes involved in adhesion and extracellular matrix remodeling develops early during renal cell carcinoma carcinogenesis and correlates with poor survival. TGF-β1 contributes to changed expression of extracellular matrix and adhesion related genes. Bioinformatic analysis performed on a broad panel of cancers of nonkidney origin suggests that disturbed expression of genes related to extracellular matrix and adhesion may be a universal feature of cancerous progression.

Expression of Genes Involved in Cellular Adhesion and Extracellular Matrix Remodeling Correlates with Poor Survival of Patients with Renal Cancer

Renal cell carcinoma is the most common highly metastatic kidney malignancy. Adhesion has a crucial role in the metastatic process. TGF (transforming growth factor)-β1 is a pleiotropic cytokine that influences cancerous transformation. We hypothesized that 1) changes in the expression of adhesion related genes may influence survival rate of patients with renal cell carcinoma and 2) TGF-β1 may contribute to changed expression of adhesion related genes. Two-step quantitative real-time polymerase chain reaction arrays were used to analyze the expression of adhesion related genes in 77 tumors and matched pair controls. The prognostic significance of genes was evaluated in TCGA (The Cancer Genome Atlas) data on 468 patients with renal cell carcinoma. Quantitative real-time polymerase chain reaction and Western blot were applied for TGF-β1 analysis. TGF-β1 mediated regulation of gene expression was analyzed by TGF-β1 supplementation of Caki-2 cells and quantitative real-time polymerase chain reaction. The expression of 19 genes related to adhesion and extracellular matrix remodeling was statistically significantly disturbed in renal cell carcinoma compared with controls. The 10-gene expression signature (COL1A1, COL5A1, COL11A1, FN1, ICAM1, ITGAL, ITGAM, ITGB2, THBS2 and TIMP1) correlated with poor survival (HR 2.85, p = 5.7e-10). TGF-β1 expression was 22 times higher in renal cell carcinoma than in controls (p <0.0001). TGF-β1 induced expression of TGFBI, COL1A1, COL5A1, COL8A1, FN1, ITGA5, ITGAM and TIMP1 in a renal cell carcinoma derived cell line. Disturbed expression of genes involved in adhesion and extracellular matrix remodeling develops early during renal cell carcinoma carcinogenesis and correlates with poor survival. TGF-β1 contributes to changed expression of extracellular matrix and adhesion related genes. Bioinformatic analysis performed on a broad panel of cancers of nonkidney origin suggests that disturbed expression of genes related to extracellular matrix and adhesion may be a universal feature of cancerous progression.

Non-canonical GLI1/2 activation by PI3K/AKT signaling in renal cell carcinoma: A novel potential therapeutic target

Renal cell carcinoma (RCC) is the most lethal urologic malignancy; however, the molecular events supporting RCC carcinogenesis and progression remain poorly understood. In this study, based on the analysis of gene expression profile data from human clear cell RCC (ccRCC) and the corresponding normal tissues, we discovered that Hedgehog (HH) pathway component genes GLI1 and GLI2 were significantly elevated in ccRCC. Survival analysis of a large cohort of ccRCC samples demonstrated that the expression of GLI1 and GLI2 was negatively correlated with patient overall survival. Clinical sample-based VHL mutation and cell model-based VHL manipulation studies all indicated that the activation of GLI1 and GLI2 was not affected by VHL status. Further signaling pathway dissections demonstrated that GLI1 and GLI2 were activated by the phosphoinositide 3-kinase (PI3K)/AKT pathway, but not mediated by the canonical HH/SMO/GLI signaling. Up-regulation of GLI1 and GLI2 promoted RCC proliferation and clonogenic ability, whereas, a combination of GLIs inhibitor Gant61 and AKT inhibitor Perifosine synergistically suppressed RCC growth and induced apoptosis in vitro and in vivo. Therefore, this study identifies that GLI1 and GLI2 are critical for RCC carcinogenesis, and also provides an alternative therapeutic strategy for RCC.