EGR2-mediated regulation of m(6)A reader IGF2BP proteins drive RCC tumorigenesis and metastasis via enhancing S1PR3 mRNA stabilization.

Emerging discoveries of dynamic and reversible N6-methyladenosine (m6A) modification on RNA in mammals have revealed the key roles of the modification in human tumorigenesis. As known m6A readers, insulin-like growth factor 2 mRNA-binding proteins (IGF2BPs) are upregulated in most cancers and mediates the enhancement of m6A-modified mRNAs stability. However, the mechanisms of IGF2BPs in renal cell cancer (RCC) still remain unclear. Bioinformatic analysis and RT-qPCR were performed to evaluate the expression of IGF2BPs and m6A writer Wilms tumor 1-associating protein (WTAP) in RCC samples and its correlation with patient prognosis. In vitro, in vivo biological assays were performed to investigate the functions of IGF2BPs and WTAP in RCC. Chromatin immunoprecipitation-qPCR (ChIP-qPCR) combined with bioinformatics analysis and following western blot assay, dual-luciferase reporter assays were performed to validate the regulatory relationships between transcription factor (TF) early growth response 2 (EGR2) and potential target genes IGF2BPs. RNA sequencing (RNA-seq), methylated RNA immunoprecipitation-qPCR (MERIP-qPCR), RIP-qPCR, m6A dot blot, and dual-luciferase reporter assays combined with bioinformatics analysis were employed to screen and validate the direct targets of IGF2BPs and WTAP. Here, we showed that early growth response 2 (EGR2) transcription factor could increase IGF2BPs expression in RCC. IGF2BPs in turn regulated sphingosine-1-phosphate receptor 3 (S1PR3) expression in an m6A-dependent manner by enhancing the stability of S1PR3 mRNA. They also promoted kidney tumorigenesis via PI3K/AKT pathway. Furthermore, IGF2BPs and WTAP upregulation predicted poor overall survival in RCC. Our studies showed that the EGR2/IGF2BPs regulatory axis and m6A-dependent regulation of S1PR3-driven RCC tumorigenesis, which enrich the m6A-modulated regulatory network in renal cell cancer. Together, our findings provide new evidence for the role of N6-methyladenosine modification in RCC.

Ying Y ，Ma X ，Fang J ，Chen S ，Wang W ，Li J ，Xie H ，Wu J ，Xie B ，Liu B ，Wang X ，Zheng X ，Xie L ... -  《Cell Death & Disease》

Wilms' tumor 1-associating protein promotes renal cell carcinoma proliferation by regulating CDK2 mRNA stability.

Tang J ，Wang F ，Cheng G ，Si S ，Sun X ，Han J ，Yu H ，Zhang W ，Lv Q ，Wei JF ，Yang H ... -  《JOURNAL OF EXPERIMENTAL & CLINICAL CANCER RESEARCH》

ZNF677 suppresses renal cell carcinoma progression through N6-methyladenosine and transcriptional repression of CDKN3.

Studies on biological functions of N6-methyladenosine (m6 A) modification in mRNA have sprung up in recent years. Previous studies have reported m6 A can determine mRNA fate and play a pivotal role in tumour development and progression. The zinc finger protein 677 (ZNF677) belongs to the zinc finger protein family and possesses transcription factor activity by binding sequence-specific DNA. The expression of ZNF677 and its clinicopathological impact were evaluated in renal cell carcinoma (RCC) patients. The m6 A level of ZNF677 was determined by m6 A methylated RNA immunoprecipitation-sequencing (MeRIP-seq) and MeRIP-qPCR in RCC tissues and adjacent normal tissues. RNA immunoprecipitation-qPCR (RIP-qPCR) and luciferase assays were performed to identify the targeted effect of IGF2BP2 and YTHDF1 on ZNF677. RCC cells and subcutaneous models uncovered the role of ZNF677 methylated by CRISPR/dCas13b-METTL3 in tumour growth. ZNF677-binding sites in the CDKN3 promoter were investigated by chromatin immunoprecipitation (ChIP) and luciferase assays. ZNF677 is frequently downregulated in RCC tissues and its low expression is associated with unfavourable prognosis and decreased m6 A modification level. Further, we find the m6 A-modified coding sequence (CDS) of ZNF677 positively regulates its translation and mRNA stability via binding with YTHDF1 and IGF2BP2, respectively. Targeted specific methylation of ZNF677 m6 A by CRISPR/dCas13b-METLL3 system can significantly increase the m6 A and expression level of ZNF677, and dramatically inhibit cell proliferation and induce cell apoptosis of RCC cells. In addition, ZNF677 exerted its tumour suppressor functions in RCC cells through transcriptional repression of CDKN3 via binding to its promoter. In vitro and clinical data confirm the negative roles of ZNF677/CDKN3 in tumour growth and progression of RCC. ZNF677 functions as a tumour suppressor and is frequently silenced via m6 A modification in RCC, which may highlight m6 A methylation-based approach for RCC diagnosis and therapy.

Li A ，Cao C ，Gan Y ，Wang X ，Wu T ，Zhang Q ，Liu Y ，Yao L ，Zhang Q ... -  《Clinical and Translational Medicine》

WTAP facilitates progression of hepatocellular carcinoma via m6A-HuR-dependent epigenetic silencing of ETS1.

Chen Y ，Peng C ，Chen J ，Chen D ，Yang B ，He B ，Hu W ，Zhang Y ，Liu H ，Dai L ，Xie H ，Zhou L ，Wu J ，Zheng S ... -  《Molecular Cancer》

KIAA1429 promotes gastric cancer progression by destabilizing RASD1 mRNA in an m(6)A-YTHDF2-dependent manner.

KIAA1429, a regulatory subunit of the N6-methyladenosine (m6A) methyltransferase complex, has been implicated in the progression of various cancers. However, the role of KIAA1429 in gastric cancer (GC) and its underlying mechanisms remain elusive. This study aimed to investigate the role of KIAA1429 in GC and to elucidate the underlying mechanisms. The expression patterns and clinical relevance of KIAA1429 in GC were assessed using quantitative real-time PCR (qRT-PCR), Western blotting, immunohistochemistry (IHC), and bioinformatic analysis. In vitro and in vivo loss- and gain-of-function assays, m6A dot blot assays, methylated RNA immunoprecipitation sequencing (MeRIP-seq), RNA-seq, MeRIP-qPCR, dual luciferase reporter assays, RNA stability assays, RNA immunoprecipitation (RIP) assays, and RNA pull-down assays were performed to investigate the biological functions and underlying molecular mechanisms of KIAA1429 in GC. Both the mRNA and protein expression of KIAA1429 were greater in GC tissues than in normal gastric tissues. High KIAA1429 expression correlated positively with poor prognosis in GC patients. KIAA1429 not only promoted GC cell proliferation, colony formation, G2/M cell cycle transition, migration, and invasion in vitro but also enhanced GC tumor growth and metastasis in vivo. Mechanistically, KIAA1429 increased the m6A level of RASD1 mRNA and enhanced its stability in an m6A-YTHDF2-dependent manner, thereby upregulating its expression. RASD1 knockdown partially rescued the KIAA1429 knockdown-induced impairment of pro‑oncogenic ability in GC cells. The expression levels of KIAA1429 and RASD1 were negatively correlated in GC tissues. KIAA1429 plays a pro‑oncogenic role in GC by downregulating RASD1 expression through destabilizing RASD1 mRNA in an m6A-YTHDF2-dependent manner. KIAA1429 may serve as a prognostic biomarker and therapeutic target for GC.

Ren M ，Pan H ，Zhou X ，Yu M ，Ji F ... -  《Journal of Translational Medicine》