Tumor Suppressor In Renal Cell Carcinoma Research Articles

Calcium saccharate/DUSP6 suppresses renal cell carcinoma glycolytic metabolism and boosts sunitinib efficacy via the ERK-AKT pathway

Current therapeutic options for renal cell carcinoma (RCC) are very limited, which is largely due to inadequate comprehension of molecular pathological mechanisms as well as RCC's resistance to chemotherapy. Dual-specificity phosphatase 6 (DUSP6) has been associated with numerous human diseases. However, its role in RCC is not well understood. Here, we show that diminished DUSP6 expression is linked to RCC progression and unfavorable prognosis. Mechanistically, DUSP6 serves as a tumor suppressor in RCC by intervening the TAF10 and BSCL2 via the ERK-AKT pathway. Further, DUSP6 is also transcriptionally regulated by HNF-4a. Moreover, docking experiments have indicated that DUSP6 expression is enhanced when bound by Calcium saccharate, which also inhibits RCC cell proliferation, metabolic rewiring, and sunitinib resistance. In conclusion, our study identifies Calcium saccharate as a prospective pharmacological therapeutic approach for RCC.

HOXD8 suppresses renal cell carcinoma growth by upregulating SHMT1 expression.

Amplification of amino acids synthesis is reported to promote tumorigenesis. The serine/glycine biosynthesis pathway is a reversible conversion of serine and glycine catalyzed by cytoplasmic serine hydroxymethyltransferase (SHMT)1 and mitochondrial SHMT2; however, the role of SHTM1 in renal cell carcinoma (RCC) is still unclear. We found that low SHMT1 expression is correlated with poor survival of RCC patients. The in vitro study showed that overexpression of SHMT1 suppressed RCC proliferation and migration. In the mouse tumor model, SHMT1 significantly retarded RCC tumor growth. Furthermore, by gene network analysis, we found several SHMT1-related genes, among which homeobox D8 (HOXD8) was identified as the SHMT1 regulator. Knockdown of HOXD8 decreased SHMT1 expression, resulting in faster RCC growth, and rescued the SHMT1 overexpression-induced cell migration defects. Additionally, ChIP assay found the binding site of HOXD8 to SHMT1 promoter was at the -456~-254 bp region. Taken together, SHMT1 functions as a tumor suppressor in RCC. The transcription factor HOXD8 can promote SHMT1 expression and suppress RCC cell proliferation and migration, which provides new mechanisms of SHMT1 in RCC tumor growth and might be used as a potential therapeutic target candidate for clinical treatment.

Suppression of lncRNA HOTAIR alleviates RCC angiogenesis through regulating miR-126/EGFL7 axis.

Renal cell carcinoma (RCC) has the highest mortality rate among urological cancers and tumor angiogenesis that plays a critical role in RCC progress. Epidermal growth factor-like domain multiple 7 (EGFL7) has been recently identified as a regulator in RCC tumor angiogenesis and progression. Long noncoding RNA (LncRNA) HOTAIR has been considered as a pro-oncogene in multiple cancers, but its precise mechanism of tumor angiogenesis has rarely been reported. MicroRNA-126 (miR-126) functions as a tumor suppressor in RCC. However, the underlying tumor angiogenesis mechanism of HOTAIR/miR-126 axis in RCC has not been studied. The proliferation, migration, angiogenesis, and expression of EGFL7 and related proteins in extracellular signal-regulated kinase (ERK)/activators of transcription 3 (STAT3) signal pathway were determined to examine the effect and mechanism of HOTAIR and miR-126 on RCC progress. The regulatory relationship of HOTAIR and miR-126, as well as miR-126 and EGFL7 were tested using dual-luciferase reporter assay. Aenograft RCC mice model was used to examine the effect of HOTAIR on RCC tumor growth and metastasis in vivo. HOTAIR knockdown and miR-126 overexpression suppressed the proliferation, migration, and angiogenesis of RCC cells. HOTAIR regulated EGFL7 expression by competitively binding to miR-126. Knockdown of HOTAIR significantly suppressed the RCC tumor progression and lung metastasis in vivo. These findings suggest that lncRNA HOTAIR regulate RCC angiogenesis through miR-126/EGFL7 axis and provide a new perspective on the molecular pathways of angiogenesis in RCC development, which might be potential therapeutic targets for RCC treatment.

MiR-143 inhibits renal cell carcinoma cells metastatic potential by suppressing ABL2.

Although micro RNA (miRNA) expression profiles are widely investigated in renal cell carcinoma (RCC), their potential roles for affecting RCC initiation and progression remain largely unknown. Here, we examined the aberrant expression profiles of miRNAs inhuman metastatic RCC tissues based on Gene Expression Omnibus (GSE37989). We further validated them iRNAs expression data in the largest clinical dataset: The Cancer Genome Atlas (TCGA). And cell adhesion and migration abilities and epithelial me senchymal transition (EMT) related proteins were assessed in both normal and tumor RCC cell lines. We suggest that hsa-miR-143 is a potential tumor suppressor in RCC as its down regulation positively correlated with adverse prognosis. Biologically, cell adhesion, migration, and EMT were dramatically inhibited by miR-143. Mechanistically, we found that miR-143 targets ABL proto-oncogene 2 (ABL2), which was also found to be an indicator for poor survival in TCGA database. Our results have important implications in understanding functions of miRNAs in metastatic RCC and will provide a basis for further clinical application.

Ubiquitin-specific peptidase 46 (USP46) suppresses renal cell carcinoma tumorigenesis through AKT pathway inactivation

USP46, a member of the ubiquitin-specific protease family, plays essential roles in cancer cell proliferation and metastasis and is used as a candidate target for cancer therapeutics. However, the effects of USP46 on renal cell carcinoma (RCC) and its underlying molecular mechanism remain unknown. In this study, the predictive and prognostic relevance of USP46 in RCC, patient-derived primary tissues, and normal liver tissues obtained from the TCGA dataset were analyzed for the USP46 mRNA levels or prognostic relevance. Gain-of-function or loss-of-function assays were used to evaluate the vital roles of USP46 in tumor cell proliferation and cell migration. As a result, the USP46 expression level in RCC is highly decreased compared to normal tissues, and the Kaplan-Meier curve showed that USP46 high expression patients had good prognoses. Functionally, the forced expression of USP46 significantly restrained tumor cell proliferation, colony formation, and cell migration. The shRNA mediated USP46 knockdown cells exhibited the opposite results. We further showed that ectopically expressed USP46 obviously inhibited the AKT signaling pathway in cancer cells, while USP46 depletion caused a dramatic increase in AKT activity reflected by phosphorylation in the serine and threonine residues of AKT or downstream p70S6K1. Importantly, MK2206, a specific AKT inhibitor, completely counteracted the effects on cell proliferation, cell migration, and AKT activity in the USP46 depletion cells. We thus revealed a novel mechanism of USP46 regulation in RCC, and our data indicate that USP46 is a tumor suppressor in RCC via AKT signaling pathway inactivation.

MiRNA‑205‑5p functions as a tumor suppressor by negatively regulating VEGFA and PI3K/Akt/mTOR signaling in renal carcinoma cells.

MicroRNAs (miRNAs) are involved in the development of various types of cancers. Dysregulation of miR-205-5p has been reported in various types of human cancer. However, little is known concerning the role of miR-205-5p in renal cell carcinoma (RCC). The pr~esent study was designed to investigate the role of miR-205-5p in RCC. The expression of miR-205-5p was measured in clear cell renal cell carcinoma (ccRCC) tissues and cell lines using RT-qPCR. RCC cell lines were transfected with miR-205-5p mimics. CCK-8 assays, wound healing assays, Matrigel invasion assays and nucleosome ELISAs were used to assess the effects of miR-205-5p on cell growth, migration, invasion and apoptosis, respectively. Western blotting was employed to detect changes in protein levels. Bioinformatic analyses and luciferase reporter assays were performed to identify the potential targets of miR-205-5p. Mouse xenograft models were used to verify the effect of miR-205-5p in vivo. The expression of miR-205-5p was found to be downregulated in 25 RCC tissues compared to that noted in the adjacent normal tissues. Decreased expression of miR-205-5p was associated with poor clinical outcomes. Based on the results of the in vitro experiments, overexpression of miR-205-5p reduced RCC cell proliferation, invasion and migration. Overexpression of miR-205-5p also promoted apoptosis and inhibited the EMT in RCC cells. Moreover, the PI3K/Akt signaling pathway was found to be negatively regulated by miR-205-5p. Bioinformatic analyses and luciferase reporter assays revealed that miR-205-5p directly targeted the 3′-UTR of vascular endothelial growth factor A (VEGFA). Furthermore, miR-205-5p negatively regulated the expression of VEGFA in ccRCC cell lines. In ccRCC tissues, miR-205-5p expression was inversely correlated with VEGFA expression. Moreover, overexpression of miR-205-5p inhibited RCC growth in vivo in a mouse xenograft model. Overall, miR-205-5p functions as a tumor suppressor in RCC by targeting VEGFA and the PI3K/Akt signaling pathway, providing a potential therapeutic target for the treatment of ccRCC.

Loss of KCNJ15 expression promotes malignant phenotypes and correlates with poor prognosis in renal carcinoma.

BackgroundKCNJ15 belongs to the inwardly rectifying potassium channel (KIR) family. Although members of the KIR family have been proven to play important roles in a variety of developmental processes, the molecular role and clinical effects of KCNJ15 in cancers remain unclear.PurposeThe aim of this study was to identify the expression, biological functions and molecular mechanisms of KCNJ15 in renal cell carcinoma (RCC).MethodsKCNJ15 mRNA expression was evaluated in kidney cancer tissue, paired adjacent normal tissue, and cell lines with qRT-PCR. KCNJ15 protein expression was investigated via western blotting and immunohistochemistry. In addition, the clinical and prognostic significance of KCNJ15 in RCC were assessed using Kaplan-Meier analysis and Cox proportional hazards analysis. In vitro, the effects of KCNJ15 on kidney cancer cells were evaluated by means of a cell counting kit-8, transwell assay along with flow cytometry, respectively. Moreover, the potential mechanism of KCNJ15 was demonstrated by Western blot.ResultsHere, we first found that KCNJ15 was significantly downregulated in RCC, and this low expression was an independent prognostic factor for clear cell RCC (ccRCC). Moreover, KCNJ15 was associated with advanced TNM stage (n=150, p=0.014) and histological grade (n=150, p=0.045). Furthermore, KCNJ15 overexpression significantly inhibited RCC cell proliferation, migration, and colony formation, arrested the cell cycle and induced apoptosis of RCC cells in vitro. The inhibitory effect of KCNJ15 overexpression may be regulated by its effects on the epithelial mesenchymal transition (EMT) process and matrix metalloproteinase (MMP)-7 and p21 expression.ConclusionThese findings indicate that KCNJ15 may be a tumor suppressor in RCC and a possible target for RCC therapy.

MiR-31-5p acts as a tumor suppressor in renal cell carcinoma by targeting cyclin-dependent kinase 1 (CDK1)

Renal cell carcinoma (RCC) accounts for more than 90% of cancers in the kidney. RCC is often asymptomatic, as a result people with RCC generally have advanced disease by the time it is discovered and has a poor prognosis compared to other cancers. Therefore, it is necessary to explore its pathogenesis and identify some reliable prognostic biomarker of RCC. miRNAs are emerging as important players in the development and progression of RCC. miR-31-5p has been reported to act as a tumor suppressor in hepatocellular carcinoma (HCC). The aim of this study is to determine the detailed molecular mechanism of miR-31-5p in the progression of RCC and to investigate its potential clinical value. In this study, RT-qPCR, EdU assay, CCK-8 assay, wound scratch assay, transwell assay, flow cytometry assay and cell cycle assay were performed to detect miR-31-5p expression and its functions in RCC. Moreover, 42 formalin-fixed paraffin-embedded (FFPE) RCC samples were used to analyze the relationship between miR-31-5p expression and patients' overall survival. Finally, luciferase reporter assay, RT-qPCR assay and western blot were used to explore the association between miR-31-5p and its potential targets. miR-31-5p was significantly down-regulated in RCC tissues and RCC cell lines compared with paired adjacent normal tissues and normal cell lines. miR-31-5p downregulation was associated with poor prognosis in RCC patients. Overexpression of miR-31-5p inhibited RCC cell proliferation, migration and invasion and cell cycle. Conversely, down-regulation of miR-31-5p promoted cell proliferation, migration and invasion. Furthermore, cyclin-dependent kinasec1 (CDK1), a key player in cell cycle regulation, was identified as a functional target of miR-31-5p. Our results suggest that miR-31-5p serves as a tumor suppressor in RCC and is expected to be a molecular biomarker for poor prognosis of RCC.

AB026. Loss of KCNJ15 expression promotes malignant phenotypes and correlates with poor prognosis in renal carcinoma

Potassium inwardly rectifying channel, subfamily J, member 15 (KCNJ15) belongs to the inwardly rectifying potassium channel (KIR) family. Although members of the KIR family have been proven to play important roles in a variety of developmental processes, the expression, biological functions and molecular mechanisms of KCNJ15 in cancers remain unclear. Here, we first found that KCNJ15 was significantly downregulated in renal cell carcinoma (RCC), and this low expression was an independent prognostic factor for clear cell RCC. Moreover, KCNJ15 was associated with advanced TNM stage (n=150, P=0.014) and histologic grade (n=150, P=0.045). Furthermore, KCNJ15 overexpression significantly inhibited RCC cell proliferation, migration, and colony formation, arrested the cell cycle and induced apoptosis of RCC cells in vitro. The inhibitory effect of KCNJ15 overexpression may be regulated by its effects on the epithelial mesenchymal transition process and matrix metalloproteinase (MMP)-7 and p21 expression. These findings indicate that KCNJ15 may be a tumour suppressor in RCC and a possible target for RCC therapy.

Long noncoding RNA HOTAIR promotes renal cell carcinoma malignancy through alpha-2, 8-sialyltransferase 4 by sponging microRNA-124.

Accumulating evidence demonstrated that the long noncoding RNA (lncRNA) HOTAIR (Hox transcript antisense intergenic RNA) plays key role in renal cell carcinoma (RCC) malignancy, while microRNA-124 (miR-124) is a tumour suppressor in RCC. The aim of this work was to assess the biological function of HOTAIR and to explore underlying mechanism involved in HOTAIR/miR-124/alpha-2, 8-sialyltransferase 4 (ST8SIA4) axis-regulated progression in RCC. Real-time PCR analyses and western blots were performed to the levels of HOTAIR, miR-124 and ST8SIA4 expression in human RCC tissues and RCC cell lines (ACHN and 786-O). Bioinformatics analysis and dual-luciferase reporter assay were used to illustrate relationship between HOTAIR and miR-124 in RCC. Colony formation assays, EdU assays, Ki67 assays and apoptosis assays were taken to evaluate cell proliferation. Tumour xenograft was created to explore the functions of HOTAIR and ST8SIA4 in tumorigenesis in vivo. Migration assays, invasion assays and cell adhesion assays and were also taken to analyse the carcinoma progression. In this study, HOTAIR level was confirmed to be significantly upregulated in RCC samples and RCC cell lines compared with those in the paired adjacent tissues and normal renal cell line. Overexpression of HOTAIR promoted the capability of proliferation, migration and invasion in RCC cell lines. HOTAIR directly bound to miR-124, while miR-124 mediated the expression of ST8SIA4 in RCC cell lines. ST8SIA4 was upregulated in RCC tissues and RCC cell lines. Ectopic expression of ST8SIA4 modulated the proliferation, migration and invasion of RCC cells. Further results indicated that HOTAIR promoted the proliferation and metastasis as a competing endogenous RNA to regulate ST8SIA4 expression by sponging miR-124 in RCC. Our results demonstrated that HOTAIR mediated RCC progression in part through miR-124/ST8SIA4 axis, which functioned as a new prognostic biomarker in RCC.

MiR-199b-5p serves as a tumor suppressor in renal cell carcinoma.

MicroRNA (miR)-199b-5p has been reported to have a critical role in various types of malignancy. However, the exact function miR-199b-5p in renal cancer remains to be fully elucidated. The present study aimed to detect the expression levels of miR-199b-5p in renal cell carcinoma (RCC) tissues and RCC cell lines, and investigated the effect of miR-199b-5p in vitro with Cell Counting Kit-8, MTT, scratch wound, Transwell and flow cytometric assays. The results demonstrated that the expression levels of miR-199b-5p were significantly downregulated in RCC tissues and cell lines compared with those in paired adjacent normal renal tissues and a reference cell line, respectively. Downregulation of miR-199b-5p by transfection with a synthetic inhibitor promoted cellular proliferation and migration, while reducing the apoptotic rate, indicating that miR-199b-5p may serve as a tumor suppressor in RCC. Further study is required to identify target genes of miR-199b-5p to elucidate the mechanisms underlying the role of miR-199b-5p in the occurrence and development of RCC.

Tumor suppressor microRNA-136-5p regulates the cellular function of renal cell carcinoma.

MicroRNAs (miRs) are involved in diverse physiological and developmental processes at the post-transcriptional level in cells. Previous studies have demonstrated that miR-136-5p is involved in certain types of cancer. However, the function of miR-136-5p in renal cell carcinoma (RCC) remains to be fully elucidated. In present study, miR-136-5p expression levels were determined by reverse transcription-quantitative polymerase chain reaction (RT-qPCR), and MTT assays, CCK-8 assays, Transwell assays, wound healing assays and flow cytometry were performed to investigate the function of miR-136-5p in RCC. RT-qPCR revealed that the expression of miR-136 was significantly lower in RCC tissues and cells compared with adjacent non-tumor tissues and cells in vitro. miR-136-5pwas also demonstrated to be associated with RCC cell proliferation, viability, migration, invasion and apoptosis. miR-136-5p may therefore function as a tumor suppressor in RCC. Further studies are required to elucidate the molecular mechanisms and signaling pathways underlying these functions of miR-136-5p, to investigate the potential function of miR-136-5p as a biomarker for the early detection and prognosis of RCC, and its potential as a therapeutic target for the treatment of RCC.

MicroRNA‑191‑5p exerts a tumor suppressive role in renal cell carcinoma

Renal cell carcinoma (RCC) is a common tumor of the urinary system. Previously, miR-191-5p has been reported to be associated with various types of cancer; however, its specific functions in RCC have not been investigated to date. In the present study, the expression of miR-191-5p in the 786-O and ACHN cell lines was detected in vitro by reverse transcription-quantitative polymerase chain reaction (RT-qPCR). The results of RT-qPCR revealed that miR-191-5p was significantly downregulated in the two cell lines compared with the 293T cell line. miR-191-5p was also significantly downregulated in RCC tissue compared with paired normal tissue. In addition, the effects of miR-191-5p on cell proliferation, migration, invasion and apoptosis were examined by CCK-8, MTT, wound scratch, Transwell and flow cytometry assays. Downregulation of miR-191-5p was observed to promote cell proliferation, migration and invasion, as well as to repress the cell apoptosis of 786-O and ACHN cells. Therefore, the current study suggests that miR-191-5p functions as a tumor suppressor in RCC. Further studies are required to uncover the underlying signaling pathway of miR-191-5p and its potential role as a biomarker for early detection and prognosis prediction, and as a therapeutic target of RCC.

MiR-411 functions as a tumor suppressor in renal cell cancer.

Recent studies have revealed that microRNAs (miRNAs) play important roles as oncogenes or tumor suppressors in tumorigenesis and tumor development, by negatively regulating protein expression. A previous study of microarrays identified that miR-411 was down-regulated in renal cell carcinoma (RCC), while few studies investigating the role of miR-411 in the pathogenesis of RCC have been performed. We assessed the miR-411 expression in RCC and paired adjacent normal tissues, as well as in RCC cell lines and a normal renal cell line, by quantitative reverse transcriptase polymerase chain reaction (qRT-PCR). Furthermore, the effects of miR-411 on RCC and normal renal cell proliferation, apoptosis and migration were determined using MTT assay, CCK-8 assay, flow cytometry and scratch wound assay following restoration of miR-411 with synthetic mimics. Results of qRT-PCR indicated that the expression of miR-411 was down-regulated in RCC tissues and cell lines when compared with adjacent normal tissues and a normal renal cell line. Further, results of CCK-8, MTT, cell scratch and transwell assay showed that over-expression of miR-411 suppressed RCC cell (786-O and ACHN) proliferation and migration. Flow cytometry assay revealed that miR-411 could induce RCC cell apoptosis. However, overexpression of miR-411 had no obvious effect on normal renal cell line 293T. To sum up, miR-411 is significantly down-regulated and plays a role as a tumor suppressor in RCC. Further studies are warranted to determine the mechanisms of miR-411 in RCC pathogenesis and define the target genes of miR-411 in RCC.

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

Sirtuins (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. Paraffin-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. SIRT1, 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). Our 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.

MiR-514a-3p functions as a tumor suppressor in renal cell carcinoma.

Renal cell carcinoma (RCC) is the most common type of kidney cancer, and the prognosis of metastatic RCC remains poor with a high rate of recurrence and mortality. A previous study has revealed that microRNA (miRNA), which negatively regulates protein expression, serves a role of oncogene or tumor suppressor. The aim of the present study was to investigate the expression and function of miR-514a-3p in RCC. To detect the expression of miR-514a-3p in 32 paired RCC tissues, quantitative polymerase chain reaction (qPCR) was performed. The function of miR-514a-3p in the proliferation, mobility and apoptosis of RCC cells (786-O and ACHN) was assessed by MTT, CCK-8, cell scratch, Transwell, Hoechst 33342 staining and flow cytometry assay. The results of qPCR revealed that miR-514a-3p was significantly downregulated in RCC tissues compared with adjacent normal tissues. Upregulation of miR-514a-3p by transfection of mimics suppressed RCC cell proliferation, migration and invasion, and induced cell apoptosis. The results revealed that miR-514a-3p was significantly downregulated in RCC and may serve a role as tumor suppressor in RCC. Further studies are required, focusing on the possibility of using miR-514a-3p as a biomarker for RCC as well as the pathway of miR-514a-3p in RCC.

Overexpression of long non-coding RNA differentiation antagonizing non-protein coding RNA inhibits the proliferation, migration and invasion and promotes apoptosis of renal cell carcinoma.

Renal cell carcinoma (RCC) is the third most common cancer in the urological system; however, the pathogenesis remains unknown. Accumulating evidence has demonstrated that long non‑coding RNAs are dysregulated in various tumors and serves an important role in tumorigenesis and development. In the present study, expression of lncRNA differentiation antagonizing non‑protein coding RNA (DANCR) in 24 paired RCC and adjacent normal tissues was detected by reverse transcription‑quantitative polymerase chain reaction. The results revealed that DANCR is downregulated in RCC tissues compared with adjacent normal tissues. Subsequent study revealed that overexpression of lncRNA DANCR by transfection of pcDNA3.1‑DANCR could suppress 786‑O and ACHN (RCC cell) proliferation, migration and invasion, and induce apoptosis compared with cells transfected with the pcDNA3.1 vector. The results revealed that DANCR functions as a tumor suppressor in RCC. In conclusion, the present study, to the best of our knowledge, was the first to reveal DANCR as a tumor suppressor. The results implicate DANCR as a potential biomarker of RCC, and further study will be focused on the clinical significance and signaling pathways of DANCR.

Identification of lncRNA EGOT as a tumor suppressor in renal cell carcinoma.

Renal cell carcinoma (RCC) is the most common type of kidney cancer and the prognosis of metastatic RCC remains poor, with a high rate of recurrence and mortality. Long non‑coding RNA (lncRNA) is a class of RNA which serves important roles in multiple cellular processes and tumorigenesis. In the present study, the expression and function of lncRNA eosinophil granule ontogeny transcript (EGOT) were examined in RCC. In 24 paired tissues (RCC tissues and adjacent normal tissues) the results of reverse transcription‑quantitative polymerase chain reaction analysis revealed that EGOT was downregulated in 22 RCC tissues compared with paired tissues. Upregulation of lncRNA EGOT by transfection of 786‑O and ACHN RCC cells with pcDNA3.1‑EGOT suppressed cell proliferation, migration and invasion, and induced RCC cell apoptosis. The results demonstrated that EGOT may serve as a tumor suppressor in RCC and may be a potential prognostic biomarker of RCC.

Epigenetic inactivation of HOXA11, a novel functional tumor suppressor for renal cell carcinoma, is associated with RCC TNM classification.

Epigenetic inactivation of HOXA11, a putative tumor suppressor, is frequently observed in a number of solid tumors, but has not been described in RCC (renal cell carcinoma). In this study, we investigated the expression, epigenetic changes and the function of HOXA11 in human renal cell carcinoma (RCC). HOXA11 was silenced or down-regulated in RCC cell lines and tissues. Methylation specific PCR (MSP) and bisulfite genomic sequencing (BGS) revealed that the HOXA11 promoter was hypermethylated in 5/6 RCC cell lines. Demethylation treatment resulted in demethylation of the promoter and increased HOXA11 expression in these cell lines. HOXA11 methylation was also detected in 68/95 (70.5%) primary RCC tumors, but only rare adjacent non-malignant renal tissues (13%, 3/23) showed hypermethylation of promoter. We also found that the methylation of HOXA11 was associated with higher TNM classification of RCC (p<0.05). Ectopic expression of HOXA11 led to significant inhibition of proliferation, colony formation, migration and invasion abilities and induced RCC cells apoptosis. Moreover, HOXA11 was found to inhibit Wnt signaling. Thus, our study demonstrated that HOXA11 function as a tumor suppressor in RCC, while it is frequently silenced by promoter methylation in RCC.

MiR-148a suppresses human renal cell carcinoma malignancy by targeting AKT2.

MicroRNA-148a (miR-148a) has been reported to be deregulated in different tumor types, whereas the biological function of miR-148a in renal cell carcinoma (RCC) largely remains unexplored. In the present study we investigated the clinical significance, biological effects, and the underlying molecular mechanisms of miR-148 in RCC. Here, we showed that miR-148a was significantly downregulated in RCC tissues and cell lines. Low expression of miR-148a in RCC tissues was associated with large tumor size, advanced TNM stage, and lymph node metastasis. Functional assays revealed that overexpression of miR-148a significantly inhibited RCC cell proliferation, colony formation, migration and invasion invitro and suppressed RCC xenograft tumor growth invivo. In addition, using quantitative RT-PCR (qRT-PCR), western blot analysis and luciferase reporter assays, AKT2 was confirmed to be a direct target of miR-148a. AKT2 expression was upregulated, and was negatively correlated with miR-148a expression in RCC tissues (r=-0.641, P<0.001). Silencing of AKT2 phenotypically copied miR-148a-induced phenotypes, whereas re-expression of AKT2 reversed the suppressive effects of miR-148a in RCC cells. Further mechanistic investigations showed that miR-148a exerted its antitumor activity via inhibition of the AKT pathway invitro and invivo. Taken together, these findings suggest that miR-148a functions as tumor suppressor in RCC by targeting AKT2.