Demethylase ALKBH5 suppresses invasion of gastric cancer via PKMYT1 m6A modification

Yiyang Hu,Yang Chen,Qiang Luo,Yufeng Xiao,Shiming Yang,Yu Hou,Chunli Gong,Zhibin Li,Sumin Wang,Jiao Liu,Yu Huang

doi:10.1186/s12943-022-01522-y

Abstract

BackgroundGastric cancer (GC) is one of the most pernicious tumors that seriously harm human healthcare. GC metastasis is one of the prime cause of failed cancer treatment, but correlation between N6-methyladenosine (m6A) and GC metastasis was less reported.MethodsMethylated RNA immunoprecipitation sequencing (MeRIP-seq) of GC tissues was conducted. Quantitative real-time PCR (qRT-PCR), western blotting and immunohistochemistry (IHC) were taken to determine the expression of ALKBH5 in GC tissues and cell lines. RNA-seq together with MeRIP-qRT-PCR was used to screen the target gene of ALKBH5. RNA pulldown, mass spectrometry and RNA immunoprecipitation (RIP) were used to search the “reader” protein of target gene. The mechanism was also validated via a tail vein injection method for lung metastasis model.ResultsDecreased expression of ALKBH5 was detected in GC samples, and it was correlated with clinical tumor distal metastasis and lymph node metastasis. ALKBH5 interference promoted metastasis of GC cells and this effect was closely related to the demethylase activity of ALKBH5. PKMYT1, as a downstream target of ALKBH5, promoted invasion and migration in GC. Caused by ALKBH5 knockdown or its demethylase activity mutation, upregulated expression of PKMYT1 indicated that ALKBH5 modulates expression of PKMYT1 in an m6A-dependent manner. IGF2BP3 helped stabilize the mRNA stability of PKMYT1 via its m6A modification site.ConclusionsThis study established an ALKBH5-PKMYT1-IGF2BP3 regulation system in metastasis, representing a new therapeutic target for GC metastasis.

Highlights

Gastric cancer (GC) is one of the most pernicious tumors that seriously harm human healthcare
MeRIP‐seq revealed a strong correlation between m6A‐modified genes and GC cell adhesion, and downregulation of demethylase alkB homolog 5 (ALKBH5) is correlated with GC prognosis To assess overall levels of m6A modification in GC, 5 pairs of clinical tumor tissues with adjacent normal samples were randomly selected
Using MeRIP-Quantitative real-time PCR (qRT-PCR) and mRNA level verification, we found that only PKMYT1 exhibited stable alterations when ALKBH5 was overexpressed or disrupted (Fig. 3B-F, S3E)

Summary

Introduction

Gastric cancer (GC) is one of the most pernicious tumors that seriously harm human healthcare. GC metastasis is one of the prime cause of failed cancer treatment, but correlation between N6-methyladenosine (m6A) and GC metastasis was less reported. Gastric cancer (GC) is the fifth most universal cancer type and ranks third among causes of cancerrelated death in the world [1, 2]. Treatment of patients with GC primarily depends on surgery, RNA modification, a form of epigenetic regulation, has been found to exist widely at the transcriptome level. As the most frequently modified form of eukaryotic mRNA, N6-methyladenosine (m6A) has been found to participate in a variety of biological processes [6, 7]. Hu et al Molecular Cancer (2022) 21:34 a reversible dynamic RNA modification regulated by m6A WERs (“writers”, “erasers” and “readers”) [8]. M6A modification of the 5’UTR of mRNA participates in mRNA splicing, stability, degradation, and polyadenylation, while modification of the 3 ’UTR contributes to the nuclear export, translation efficiency, and maintenance of the structural stability of mRNA [9,10,11,12,13,14]

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Results

Discussion

Conclusion