MicroRNA Expression Profiling in Clear Cell Renal Cell Carcinoma: Identification and Functional Validation of Key miRNAs.

Haowei He,Jingping Ge,Dong Wang,Zhengyu Zhang,Hao Tang,Longxin Wang,Song Xu,Chaopeng Tang,Xiaoming Yi,Jie Dong,Wenquan Zhou,Linhui Wang,Kandiah Jeyaseelan

doi:10.1371/journal.pone.0125672

Abstract

ObjectiveThis study aims to profile dysregulated microRNA (miRNA) expression in clear cell renal cell carcinoma (ccRCC) and to identify key regulatory miRNAs in ccRCC.Methods and ResultsmiRNA expression profiles in nine pairs of ccRCC tumor samples at three different stages and the adjacent, non-tumorous tissues were investigated using miRNA arrays. Eleven miRNAs were identified to be commonly dysregulated, including three up-regulated (miR-487a, miR-491-3p and miR-452) and eight down-regulated (miR-125b, miR-142-3p, miR-199a-5p, miR-22, miR-299-3p, miR-29a, miR-429, and miR-532-5p) in tumor tissues as compared with adjacent normal tissues. The 11 miRNAs and their predicted target genes were analyzed by Gene Ontology and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analysis, and three key miRNAs (miR-199a-5p, miR-22 and miR-429) were identified by microRNA-gene network analysis. Dysregulation of the three key miRNAs were further validated in another cohort of 15 ccRCC samples, and the human kidney carcinoma cell line 786-O, as compared with five normal kidney samples. Further investigation showed that over-expression of miR-199a-5p significantly inhibited the invasion ability of 786-O cells. Luciferase reporter assays indicated that miR-199a-5p regulated expression of TGFBR1 and JunB by directly interacting with their 3’ untranslated regions. Transfection of miR-199a-5p successfully suppressed expression of TGFBR1 and JunB in the human embryonic kidney 293T cells, further confirming the direct regulation of miR-199a-5p on these two genes.ConclusionsThis study identified 11 commonly dysregulated miRNAs in ccRCC, three of which (miR-199a-5p, miR-22 and miR-429) may represent key miRNAs involved in the pathogenesis of ccRCC. Further studies suggested that miR-199a-5p plays an important role in inhibition of cell invasion of ccRCC cells by suppressing expression of TGFBR1 and JunB.

Highlights

Renal cell carcinoma (RCC) constitutes about 3% of all human cancers [1]
This study identified 11 commonly dysregulated miRNAs in clear cell renal cell carcinoma (ccRCC), three of which may represent key miRNAs involved in the pathogenesis of PLOS ONE | DOI:10.1371/journal.pone
Further studies suggested that miR-199a-5p plays an important role in inhibition of cell invasion of ccRCC cells by suppressing expression of TGFBR1 and JunB

Summary

Introduction

Renal cell carcinoma (RCC) constitutes about 3% of all human cancers [1]. Of the various histological subsets, clear cell renal cell carcinoma (ccRCC) is the most common subtype at diagnosis and accounts for 75–88% of RCCs in contemporary surgical series [2,3]. The average age at diagnosis of ccRCC is 60–64 years [2,4,5], there are 7% of sporadic ccRCC cases diagnosed at ages younger than 40 years [6]. Current approaches of chemotherapy and radiotherapy have only limited efficacy on ccRCC [7], and novel effective targeted agents for metastatic disease fail to work on ccRCC patients with distant metastases [8,9]. There is an urgent need to elucidate the molecular basis of ccRCC so as to identify effective therapeutic targets in the future

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Conclusion