Aberrant N6-methyladenosine (m6A) modification has emerged as a driver of tumor initiation and progression, yet how long noncoding RNAs (lncRNA) are involved in the regulation of m6A remains unknown. Here we utilize data from 12 cancer types from The Cancer Genome Atlas to comprehensively map lncRNAs that are potentially deregulated by DNA methylation. A novel DNA methylation–deregulated and RNA m6A reader–cooperating lncRNA (DMDRMR) facilitated tumor growth and metastasis in clear cell renal cell carcinoma (ccRCC). Mechanistically, DMDRMR bound insulin-like growth factor 2 mRNA-binding protein 3 (IGF2BP3) to stabilize target genes, including the cell-cycle kinase CDK4 and three extracellular matrix components (COL6A1, LAMA5, and FN1), by specifically enhancing IGF2BP3 activity on them in an m6A-dependent manner. Consequently, DMDRMR and IGF2BP3 enhanced the G1–S transition, thus promoting cell proliferation in ccRCC. In patients with ccRCC, high coexpression of DMDRMR and IGF2BP3 was associated with poor outcomes. Our findings reveal that DMDRMR cooperates with IGF2BP3 to regulate target genes in an m6A-dependent manner and may represent a potential diagnostic, prognostic, and therapeutic target in ccRCC. Significance: This study demonstrates that the lncRNA DMDRMR acts as a cofactor for IGF2BP3 to stabilize target genes in an m6A-dependent manner, thus exerting essential oncogenic roles in ccRCC.

Clear cell renal cell carcinoma (ccRCC) patients are highly angiogenic and treated by targeted therapies against VEGFA/VEGFR signaling pathway. However, tumors with such targeted therapies remain a significant clinic challenge. Understanding the underlying mechanism against angiogenesis is highly desired. Here, we demonstrated that the lncRNA DMDRMR serves as a sponge of miR-378a-5p to increase EZH2 and SMURF1 expression, thus promoting EZH2-mediated transcriptional repression of DAB2IP and SMURF1-mediated degradation of DAB2IP. Consequently, this axis activates VEGFA/VEGFR2 signaling pathway, resulting in angiogenesis and resistance of tumor cells to sunitinib in ccRCC. Moreover, the competing endogenous RNA regulatory axis of DMDRMR is clinically relevant to ccRCC pathogenesis and prognosis of patients with ccRCC. Our results support that the DMDRMR/miR-378a-5p/DAB2IP axis may serve as a novel target for combination diagnosis or therapy of ccRCC patients. Our findings may have highly clinical relevance for future translation to develop the targeted therapies for patients with ccRCC.

Epithelial-mesenchymal transition (EMT) is associated with the invasive and metastatic phenotypes in colorectal cancer (CRC). However, the mechanisms underlying EMT in CRC are not completely understood. In this study, we find that HUNK inhibits EMT and metastasis of CRC cells via its substrate GEF-H1 in a kinase-dependent manner. Mechanistically, HUNK directly phosphorylates GEF-H1 at serine 645 (S645) site, which activates RhoA and consequently leads to a cascade of phosphorylation of LIMK-1/CFL-1, thereby stabilizing F-actin and inhibiting EMT. Clinically, the levels of both HUNK expression and phosphorylation S645 of GEH-H1 are not only downregulated in CRC tissues with metastasis compared with that without metastasis, but also positively correlated among these tissues. Our findings highlight the importance of HUNK kinase direct phosphorylation of GEF-H1 in regulation of EMT and metastasis of CRC.