MKRN1/2 serve as tumor suppressors in renal clear cell carcinoma by regulating the expression of p53.

Background: Kidney renal clear cell carcinoma (KIRC) belongs to renal cell carcinoma which is a very aggressive malignant tumor with poor prognosis and high mortality. The MKRN family includes three members MKRN1, MKRN2 and MKRN3, which are closely related to cancers, and have been involved in many studies.

Objective: This study aimed to explore the roles of MKRN family in KIRC.

Methods: The expression of MKRNs was analyzed using the UALCAN database, prognostic analysis was performed with the GEPIA2 and Kaplan-Meier Plotter database, and correlation analysis was assessed by GEPIA2. The CCK-8 and colony formation assay were performed to detect cell proliferation, wound healing assays were performed to detect cell migration, cell cycles were detected by flow cytometry analysis, GST pull-down and co-immunoprecipitation assays were performed to detect the interaction of proteins, and the expression of MKRNs, p53 and other proteins were detect by immunoblotting analysis or quantitative PCR (qPCR).

Results: MKRN1 and MKRN2 were lowly expressed in KIRC samples compared to the corresponding normal tissues, and KIRC patients with high levels of MKRN1 and MKRN2 showed higher overall survival (OS) and disease free survival (DFS) rates. The overexpression of MKRN1 and MKRN2 inhibited the proliferation of human KIRC cells by arresting the cell cycles, but shows little effect on cells migration. The expression of MKRN1 and MKRN2 are correlated, and MKRN1 directly interacts with MKRN2. Moreover, both MKRN1 and MKRN2 were closely correlated with the expression of TP53 in KIRC tumor, and promoted the expression of p53 both at protein and mRNA levels.

Conclusions: Our study suggests that MKRN1 and MKRN2 serve as tumor suppressors in KIRC, and act as promising therapeutic targets for KIRC treatment.