Exploring the role of miRNAs in renal cell carcinoma progression and metastasis through bioinformatic and experimental analyses

Abstract

Metastasis results in most of the cancer deaths in clear cell renal cell carcinoma (ccRCC). MicroRNAs (miRNAs) regulate many important cell functions and play important roles in tumor development, metastasis and progression. In our previous study, we identified a miRNA signature for metastatic RCC. In this study, we validated the top differentially expressed miRNAs on matched primary and metastatic ccRCC pairs by quantitative polymerase chain reaction. We performed bioinformatics analyses including target prediction and combinatorial analysis of previously reported miRNAs involved in tumour progression and metastasis. We also examined the co-expression of the miRNAs clusters and compared expression of intronic miRNAs and their host genes. We observed significant dysregulation between primary and metastatic tumours from the same patient. This indicates that, at least in part, the metastatic signature develops gradually during tumour progression. We identified metastasis-dysregulated miRNAs that can target a number of genes previously found to be involved in metastasis of kidney cancer as well as other malignancies. In addition, we found a negative correlation of expression of miR-126 and its target vascular endothelial growth factor (VEGF)-A. Cluster analysis showed that members of the same miRNA cluster follow the same expression pattern, suggesting the presence of a locus control regulation. We also observed a positive correlation of expression between intronic miRNAs and their host genes, thus revealing another potential control mechanism for miRNAs. Many of the significantly dysregulated miRNAs in metastatic ccRCC are highly conserved among species. Our analysis suggests that miRNAs are involved in ccRCC metastasis and may represent potential biomarkers.

miR-10b is a prognostic marker in clear cell renal cell carcinoma

“…We further compared miR-10b expression level in another set of matched pairs of metastatic and primary ccRCC tumours. Our results demonstrated miR-10b downregulation in metastatic compared with primary RCC 30 31. miR-10b was also among miRNAs that are downregulated in metastatic compared with non-metastatic RCC in other studies32 33 …”

miR-210 Is a Prognostic Marker in Clear Cell Renal Cell Carcinoma

“…Total RNA was extracted with miRNeasy (Qiagen, Mississauga, ON, Canada) according to the manufacturer's protocol, as described previously. 22 Total RNA concentrations were determined spectrophotometrically (NanoDrop 1000 Spectrophotometer; NanoDrop Technologies Inc., Wilmington, DE). Samples optimal for analysis were stored at À80 C.…”

Quantitative Proteomic Analysis in Metastatic Renal Cell Carcinoma Reveals a Unique Set of Proteins with Potential Prognostic Significance

“…Differential protein expression between primary RCC and normal tissues was previously studied (16 -18). Also, differential expression between primary and metastatic kidney disease has been investigated at the microRNA level (19,20). Molecular analyses hold the promise of providing a better understanding of the pathogenesis of kidney cancer (21).…”