Identification of angiogenesis-related miRNAs in a population of patients with renal clear cell carcinoma

In the present study, we compared the expression of miRNAs and angiogenesis-related genes in the renal tumors and adjacent normal renal tissues of patients with clear cell renal cell carcinoma (ccRCC). The first part of the present study was a preliminary analysis of 4 patients with stage T1a/b ccRCC that measured the levels of angiogenesis and expression of angiogenesis-related genes and miRNAs in the tumors and adjacent normal renal tissues. The second part of this study was an analysis of 30 patients with stage T1, T2 or T3 ccRCC that employed qPCR to characterize expression of angiogenesis-related miRNAs in the tumors and adjacent normal tissues. The first part of this study indicated that all 4 patients had increased levels of CD34 in tumors, indicating elevated angiogenesis. However, quantitative analysis of microvessel density and expression of miRNAs indicated highly variable results among these patients. The data of all patients in the present study indicated that more patients with stage T1 ccRCC had higher expression of miR-126 and miR-378 in their normal tissues, whereas more patients with stage T2/3 ccRCC had higher expression of these miRNAs in their tumor tissues. The tumors of patients with ccRCC had lower expression of miR-126 and miR-378 during the early stages of disease (T1), but higher expression of these miRNAs during the later stages of disease (T2/T3).