m6A is the most common form of mRNA modification. However, little is known about its role in clear cell renal cell carcinoma (ccRCC). This study aims to identify gene signatures and prognostic values of m6A regulators in ccRCC. In this study, a total of 528 ccRCC patients from TCGA database with sequencing and CNV data were included. Survival analysis was performed using log-rank tests and Cox regression model. The association between alteration of m6A regulators and clinicopathological characteristics was examined using chi-square test. The results showed that alteration of m6A regulators was associated with pathologic stage. Patients with any CNVs of the regulatory genes had worse OS and DFS than those with diploid genes. Moreover, deletion of m6A “writer” genes was an independent risk factor for OS, and copy number gain of “eraser” genes could magnify the effect in a synergistic way. Additionally, low expression of the writer gene METTL3 was related to activations of adipogenesis and mTOR pathways. Thus, we for the first time determined genetic alterations of m6A regulators in ccRCC and found a significant relationship between the alterations and worse clinical characteristics. The findings provide us clues to understand epigenetic modification of RNA in ccRCC.

TP53 is a classic tumor suppressor, but its role in kidney cancer remains unclear. In our study, we tried to explain the role of p53 in kidney cancer through the p53-related enhancer RNA pathway. Functional experiments were used to explore whether P53-bound enhancer regions 2 (p53BER2) has a role in the cell cycle and senescence response of TP53-wild type (WT) renal cancer cells in vitro or vivo. RNA-sequencing was used to identify the potential target of p53BER2. The results showed that the expression level of P53BER2 was downregulated in renal cancer tissues and cell lines, further dual-luciferase experiments and APR-256-reactivated experiments showed p53BER2 expresses in a p53-dependent way. Moreover, knockdown p53BER2 could reverse nutlin-3-induced cytotoxic effect in TP53-WT cell lines. Further exploration showed the downregulation of p53BER2 could reverse nutlin-3-induced G1-arrest and senescence in TP53-WT cell lines. What is more, the knockdown of p53BER2 showed resistance to nutlin-3 treatment in vivo. Additionally, we found BRCA2 could be regulated by p53BER2 in vitro and vivo; further experiment showed p53BER2 could induce cell-cycle arrest and DNA repair by mediating BRCA2. In summary, the p53-associated enhancer RNA-p53BER2 mediates the cell cycle and senescence of p53 in TP53-WT renal cancer cells.

Tribbles pseudokinase 3 (TRIB3) is a member of the mammalian pseudokinase tribbles family and is involved in multiple biological processes. However, the role of TRIB3 in renal cell carcinoma (RCC) remains unclear. In this study, we aimed to elucidate the biological functions of TRIB3 in RCC and explore its underlying mechanisms. TRIB3 expression and its correlation with clinicopathological features was evaluated in 123 patients with RCC. A series of cytological experiments were performed to clarify the biological functions of TRIB3, and potential molecular regulatory mechanisms were explored using transcriptome sequencing. TRIB3 expression was significantly elevated in RCC tissues compared to that in paracancerous tissues, and high expression of TRIB3 was correlated with both advanced tumor stage and unfavorable prognosis. TRIB3 knockdown markedly inhibited RCC cell proliferation, migration and invasion. Furthermore, overexpression of TRIB3 promoted RCC cell proliferation, migration, invasion and xenograft tumor growth. Notably, TRIB3 expression was modulated by hypoxia-inducible factor-1α (HIF-1α), which enhanced cell viability and invasiveness via targeting the MAPK signaling pathway. This study reveals the potential oncogenic role of TRIB3 in RCC pathogenesis and illustrates the mechanisms underlying TRIB3-mediated tumor progression, providing new insight into the development of TRIB3 as a tumor biomarker and therapeutic target.