MicroRNA-375 Suppresses the Tumor Aggressive Phenotypes of Clear Cell Renal Cell Carcinomas through Regulating YWHAZ

Abstract

Background:MicroRNAs (miRNAs) are key regulators during tumor initiation and progression. MicroRNA-375 (MiR-375) has been proven to play a tumor-suppressive role in various types of human malignancies; however, its biological role in clear cell renal cell carcinoma (ccRCC) remains unclear. The purpose of this study was to explore the biologic role as well as the underlying mechanism of miR-375 in ccRCC progression.Methods:Quantitative polymerase chain reaction (qPCR) was applied to test the expression of miR-375 in tissues and cell lines by t-test. Functional experiments were used to investigate the biological role of miR-375 utilizing a gain-of-function strategy. The target of miR-375 was investigated by bioinformatic analysis and further verified by luciferase reporter assay, qPCR, Western blotting, and functional experiments in vitro.Results:Our study demonstrated that miR-375 was significantly downregulated in ccRCC tissues (cancer vs. normal, 0.804 ± 0.079 vs. 1.784 ± 0.200, t = 5.531 P < 0.0001) and cell lines, and loss of miR-375 expression significantly associated with advanced Fuhrman nuclear grades (Grade III and IV vs. Grade I and II, 1.000 ± 0.099 vs. 1.731 ± 0.189, t = 3.262 P = 0.003). Functional studies demonstrated that miR-375 suppressed ccRCC cell proliferation, migration, and invasion (all P < 0.05 in both 786-O and A498 cell lines). Multiple miRNA target prediction algorithms indicated the well-studied oncogene YWHAZ as a direct target of miR-375, which was further confirmed by the luciferase reporter assay, qPCR, and Western blotting. Moreover, restoration of YWHAZ could rescue the antiproliferation effect of miR-375.Conclusions:The data provide the solid evidence that miR-375 plays a tumor-suppressive role in ccRCC progression, partially through regulating YWHAZ. This study expands the antitumor profile of miR-375, and supports its role as a potential therapeutic target in ccRCC treatment.

Molecular Mechanisms in Clear Cell Renal Cell Carcinoma: Role of miRNAs and Hypermethylated miRNA Genes in Crucial Oncogenic Pathways and Processes

“…Our data concerning the correlation of miR-375 hypermethylation with metastasis strengthens the evidence that the suppression of the tumor aggressive phenotypes of ccRCC mediated by this miRNA regulates the oncogene YWHAZ , which is its direct target (Zhang X. et al, 2018). As discussed earlier, aberrantly methylated miR-148a was suggested to function as a tumor suppressor in RCC by targeting AKT2 (Cao et al, 2017).…”

The clinical and prognostic significance of YWHAZ in non‐small–cell lung cancer patients: Immunohistochemical analysis

“…25 In prostate cancer patients, high levels of YWHAZ expression were correlated with high Gleason score, PSA relapse and castration-resistant. [35][36][37][38][39] Therefore, we will further try to explore the molecular mechanism of YWHAZ in NSCLC cell at following studies. 27 In our study, we assessed the prognostic value of YWHAZ in NSCLC patients through analyzing the TCGA database, and found YWHAZ expression was negatively correlated with overall survival time in lung adenocarcinoma patients, but not significantly associated overall survival time in lung squamous cell carcinoma patients.…”

Long Non-coding RNA LINC01094 Promotes the Development of Clear Cell Renal Cell Carcinoma by Upregulating SLC2A3 via MicroRNA-184

“…Emerging evidence implicates that lncRNAs can bind to microRNAs (miRNAs; Du et al, 2016 ). Whilst miRNAs play pivotal roles during tumor initiation and progression ( Zhang et al, 2018 ). It has also been suggested that aberrantly expressed miRNAs are related to the occurrence and development of ccRCC through participating in critical biological processes ( Zhao et al, 2018 ).…”