Alternative polyadenylation reprogramming of MORC2 induced by NUDT21 loss promotes KIRC carcinogenesis
Yuqin Tan, … , Ke Li, Ning Na
Yuqin Tan, … , Ke Li, Ning Na
Published September 22, 2023
Citation Information: JCI Insight. 2023;8(18):e162893. https://doi.org/10.1172/jci.insight.162893.
View: Text | PDF
Research Article Oncology

Alternative polyadenylation reprogramming of MORC2 induced by NUDT21 loss promotes KIRC carcinogenesis

Abstract

Alternative polyadenylation (APA), a posttranscriptional mechanism of gene expression via determination of 3′UTR length, has an emerging role in carcinogenesis. Although abundant APA reprogramming is found in kidney renal clear cell carcinoma (KIRC), which is one of the major malignancies, whether APA functions in KIRC remains unknown. Herein, we found that chromatin modifier MORC2 gained oncogenic potential in KIRC among the genes with APA reprogramming, and moreover, its oncogenic potential was enhanced by 3′UTR shortening through stabilization of MORC2 mRNA. MORC2 was found to function in KIRC by downregulating tumor suppressor DAPK1 via DNA methylation. Mechanistically, MORC2 recruited DNMT3A to facilitate hypermethylation of the DAPK1 promoter, which was strengthened by 3′UTR shortening of MORC2. Furthermore, loss of APA regulator NUDT21, which was induced by DNMT3B-mediated promoter methylation, was identified as responsible for 3′UTR shortening of MORC2 in KIRC. Additionally, NUDT21 was confirmed to act as a tumor suppressor mainly depending on downregulation of MORC2. Finally, we designed an antisense oligonucleotide (ASO) to enhance NUDT21 expression and validated its antitumor effect in vivo and in vitro. This study uncovers the DNMT3B/NUDT21/APA/MORC2/DAPK1 regulatory axis in KIRC, disclosing the role of APA in KIRC and the crosstalk between DNA methylation and APA.

Authors

Yuqin Tan, Tong Zheng, Zijun Su, Min Chen, Suxiang Chen, Rui Zhang, Ruojiao Wang, Ke Li, Ning Na

×

Figure 4

3′UTR shortening upregulates MORC2 expression by stabilizing MORC2 mRNA.

Options: View larger image (or click on image) Download as PowerPoint
3′UTR shortening upregulates MORC2 expression by stabilizing MORC2 mRNA....
(A) qPCR was performed to evaluate the ratio of long 3′UTR MORC2 expression/total MORC2 expression in 12 pairs of KIRC tissues and matched normal tissues (n = 3). (B) qPCR was performed to evaluate expression of MORC2 in 12 pairs of KIRC tissues and matched normal tissues (n = 3). (C) The correlation between the extent of MORC2 3′UTR shortening and the extent of MORC2 upregulation in KIRC tissues was analyzed. (D) Luciferase reporter assay was performed to examine luciferase activity produced by plasmids carrying short or long 3′UTR of MORC2 (n = 3). (E and F) Isoform-specific qPCR was performed to evaluate (E) and quantitatively analyze (F) the half-life of long and short 3′UTR MORC2 in Caki-1 (left) and A498 (right) cells (n = 3). (G and H) qPCR was performed to evaluate (G) and quantitatively analyze (H) the half-life of MORC2 in WT and S-KO Caki-1 cells (n = 3). (I) Schematic diagram indicating the binding site of miR–145-5p at 3′UTR of MORC2. (J) Luciferase reporter assay was performed to evaluate the effect of miR–145-5p on short or long 3′UTR of MORC2 in Caki-1 and A498 cells (n = 3). All data represent the mean ± SD. Two-tailed t test were performed. *P < 0.05; **P < 0.01; ***P < 0.001.