ALKBH5 promotes invasion and metastasis of gastric cancer by decreasing methylation of the lncRNA NEAT1

Abstract

N 6 -Methyladenosine (m 6 A) is the most common posttranscriptional modification of RNA and plays critical roles in cancer pathogenesis. However, the biological function of long noncoding RNA (lncRNA) methylation remains unclear. As a demethylase, ALKBH5 (alkylation repair homolog protein 5) is involved in mediating methylation reversal. The purpose of this study was to investigate lncRNA m 6 A modification and its role in gastric cancer (GC). Bioinformatics predicted interactions of ALKBH5 with lncRNAs. Five methods were employed to assess the function of nuclear paraspeckle assembly transcript 1 (NEAT1), including gene silencing, RT-PCR, separation of nuclear and cytoplasmic fractions, scrape motility assays, and transwell migration assays. Then, m 6 A RNA immunoprecipitation and immunofluorescence were used to detect methylated NEAT1 in GC cells. Rescue assays were performed to define the relationship between NEAT1 and ALKBH5. NEAT1 is a potential binding lncRNA of ALKBH5. NEAT1 was overexpressed in GC cells and tissue. Additional experiments confirmed that knockdown of NEAT1 significantly repressed invasion and metastasis of GC cells. ALKBH5 affected the m 6 A level of NEAT1. The binding of ALKBH5 and NEAT1 influences the expression of EZH2 (a subunit of the polycomb repressive complex) and thus affects GC invasion and metastasis. Our findings indicate a novel mechanism by which ALKBH5 promotes GC invasion and metastasis by demethylating the lncRNA NEAT1. They may be potential therapeutic targets for GC.

lncRNA NEAT1 Inhibits Proliferation, Invasion and Epithelial-mesenchymal Transition of Gastric Cancer Cells by Regulating MiR-129-5p/PBX3 Axis

“…In our study, NEAT1 was observed to be overexpressed in both GC tissues and cells, and the inhibited NEAT1 expression in GC cells brought about greatly inhibited proliferation, invasion and EMT, and remarkably dropped apoptosis rate of GC cells, indicating that NEAT1 might act as an oncogene in GC. Studies in the past [20] demonstrated that NEAT1 was up-regulated in GC, and the overexpressed NEAT1 could synergize with EZH2 to promote the invasion and metastasis of GC cells, which validated our results and explains the possible mechanism of NEAT1 in GC from another aspect.…”

VIRMA-Dependent N6-Methyladenosine Modifications Regulate the Expression of Long Non-Coding RNAs CCAT1 and CCAT2 in Prostate Cancer

“…Nevertheless, findings regarding m 6 A function in tumor progression are still under debate as the involvement of individual protein factors appears to be tissue and context specific. For instance, m 6 A demethylase ALKBH5 was reported to induce gastric cancer metastasis by demethylating lncRNA NEAT1 [26], whereas an earlier study showed an important role for ALKBH5 in inhibiting pancreatic cancer progression [27]. Similarly, METTL14 seems to play an oncogenic function in acute myeloid leukemia [28], but in hepatocellular carcinoma, it behaves as metastasis suppressor by modulating m 6 A dependent microRNA processing [24].…”

Identification and validation of a novel prognostic index based on m6A RNA methylation regulators in esophageal carcinoma

“…Moreover, ALKBH5 can inhibit pancreatic cancer through regulating WIF-1 RNA methylation and Wnt signaling pathway [34]. On the contrary, ALKBH5 was also reported to be an candidate oncogene in other cancers, including ovarian cancer [35], breast cancer [36], and gastric cancer [37]. Given that the opposite role of ALKBH5 in different cancers, more experimental studies are highly demand.…”