MicroRNA Expression Profiling in Clear Cell Renal Cell Carcinoma: Identification and Functional Validation of Key miRNAs.
OBJECTIVE
This study aims to profile dysregulated microRNA (miRNA) expression in clear cell renal cell carcinoma (ccRCC) and to identify key regulatory miRNAs in ccRCC.


RESULTS
miRNA 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.


CONCLUSIONS
This 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.
Department of Urology, Jinling Hospital, Nanjing University Medical School, Nanjing, Jiangsu, China.
Haowei
H
He
Department of Urology, Changzheng Hospital, Second Military Medical University, Shanghai, Shanghai, China.
Linhui
L
Wang
Department of Urology, Jinling Hospital, Nanjing University Medical School, Nanjing, Jiangsu, China.
Wenquan
W
Zhou
Department of Urology, Jinling Hospital, Nanjing University Medical School, Nanjing, Jiangsu, China.
Zhengyu
Z
Zhang
Department of Urology, Jinling Hospital, Nanjing University Medical School, Nanjing, Jiangsu, China.
Longxin
L
Wang
Department of Urology, Jinling Hospital, Nanjing University Medical School, Nanjing, Jiangsu, China.
Song
S
Xu
Department of Urology, Jinling Hospital, Nanjing University Medical School, Nanjing, Jiangsu, China.
Dong
D
Wang
Department of Urology, Jinling Hospital, Nanjing University Medical School, Nanjing, Jiangsu, China.
Jie
J
Dong
Department of Urology, Jinling Hospital, Nanjing University Medical School, Nanjing, Jiangsu, China.
Chaopeng
C
Tang
Department of Urology, Jinling Hospital, Nanjing University Medical School, Nanjing, Jiangsu, China.
Hao
H
Tang
Department of Urology, Jinling Hospital, Nanjing University Medical School, Nanjing, Jiangsu, China.
Xiaoming
X
Yi
Department of Urology, Jinling Hospital, Nanjing University Medical School, Nanjing, Jiangsu, China.
Jingping
J
Ge
D002292:Carcinoma, Renal Cell / Q000235:genetics*; D045744:Cell Line, Tumor; D015536:Down-Regulation / Q000235:genetics; D020869:Gene Expression Profiling; D015972:Gene Expression Regulation, Neoplastic; D053263:Gene Regulatory Networks; D006801:Humans; D007680:Kidney Neoplasms / Q000235:genetics*; D035683:MicroRNAs / Q000235:genetics* / Q000378:metabolism; D009361:Neoplasm Invasiveness; D009363:Neoplasm Proteins / Q000378:metabolism; D020411:Oligonucleotide Array Sequence Analysis; D015203:Reproducibility of Results
D035683:MicroRNAs; D009363:Neoplasm Proteins