RNA demethylase ALKBH5 prevents pancreatic cancer progression by posttranscriptional activation of PER1 in an m6A-YTHDF2-dependent manner

Abstract

Background N6-methyladenosine (m6A) is the most abundant reversible methylation modification of eukaryotic mRNA, and it plays vital roles in tumourigenesis. This study aimed to explore the role of the m6A demethylase ALKBH5 in pancreatic cancer (PC). Methods The expression of ALKBH5 and its clinicopathological impact were evaluated in PC cohorts. The effects of ALKBH5 on the biological characteristics of PC cells were investigated on the basis of gain-of-function and loss-of-function analyses. Subcutaneous and orthotopic models further uncovered the role of ALKBH5 in tumour growth. mRNA and m6A sequencing and assays of m6A methylated RNA immunoprecipitation-qPCR (MeRIP-qPCR) were performed to identify the targeted effect of ALKBH5 on PER1. P53-binding sites in the ALKBH5 promoter were investigated by ChIP and luciferase assays to reveal the interplay between ALKBH5 and PER1-activated ATM-CHK2-P53/CDC25C signalling. Results ALKBH5 loss characterized the occurrence and poor clinicopathological manifestations in patients with PC. Overexpression of ALKBH5 reduced tumoural proliferative, migrative, invasive activities in vitro and ameliorated tumour growth in vivo, whereas ALKBH5 knockdown facilitated PC progression. Mechanistically, ALKBH5 posttranscriptionally activated PER1 by m6A demethylation in an m6A-YTHDF2-dependent manner. PER1 upregulation led to the reactivation of ATM-CHK2-P53/CDC25C signalling, which inhibited cell growth. P53-induced activation of ALKBH5 transcription acted as a feedback loop regulating the m6A modifications in PC. Conclusion ALKBH5 serves as a PC suppressor by regulating the posttranscriptional activation of PER1 through m6A abolishment, which may highlight a demethylation-based approach for PC diagnosis and therapy.

m6A regulator-based methylation modification patterns characterized by distinct tumor microenvironment immune profiles in colon cancer

“…Subsequent correlation analysis also revealed that the two m 6 A-writers were inversely associated with immune cell infiltration. Inversely, the m 6 A RNA demethylase ALKBH5 exhibited an obvious enhancement in T lymphocyte infiltration and significant up-regulation in normal samples, indicating that the multiple types of post-transcriptional regulation underlay anti-tumor effects 76 , 77 . Together, these results suggest a diverse heterogeneity of m 6 A modification, demonstrating the importance of a comprehensive assessment of the m 6 A modification patterns and enhancing our understanding of epigenetic regulation on diverse physiological processes.…”

Upregulation of METTL14 mediates the elevation of PERP mRNA N6 adenosine methylation promoting the growth and metastasis of pancreatic cancer

“…In pancreatic cancer, it was reported that METTL3 promotes cancer progression and chemo- and radio-resistance [ 34 , 48 ]. Although it was confirmed that ALKBH5 functions as a tumor-suppressor gene, involved in sensitizing pancreatic cancer cells to chemotherapy via direct impact on Wnt inhibitory factor 1, the m 6 A eraser was also reported to prevent pancreatic cancer progression by posttranscriptional activation of PER1 in an m 6 A-YTHDF2-dependent Manner [ 35 , 36 ]. Here, we present the first study on the expression of METTL14, one of the main m 6 A regulators, in pancreatic cancer.…”

“…A previous study reported that METTL3, ALKBH5 and YTHDF2 play important roles in pancreatic cancer cells [33][34][35][36]. However, the underlying mechanism by which aberrant m 6 A modifications facilitate the growth of pancreatic cancer has not been determined.…”

The RNA methyltransferase NSUN6 suppresses pancreatic cancer development by regulating cell proliferation

“…Among these, N6-methyladenosine (m6A) is the best understood and frequent mark of mRNA, and the functions of which ranges from pre-mRNA processing, translation, miRNA biogenesis to mRNA decay [30] . The importance of METTL3 and ALKBH5 in the development and progression of pancreatic cancer have pointed out [31 , 32] . By contrast, much less research has been conducted on m5C, which was detected in tRNAs and rRNAs and more recently in poly(A)RNAs.…”