YTHDC2-mediated m6A mRNA modification of Id3 suppresses cisplatin resistance in non-small cell lung cancer

BACKGROUND: The methylation of adenosines at the N6 position (N6-methyladenosine; m6A) is one of the most conserved internal RNA modifications. m6A can modulate the expression of oncogenes or tumor suppressor genes, as well as m6A levels and the expression and activity of m6A enzymes, thus influencing tumor progression and therapeutic response. This study investigates the role of YTHDC2-mediated m6A messenger RNA (mRNA) modification of Id3 in controlling cisplatin resistance in non-small cell lung cancer (NSCLC). METHODS: The expression of the m6A reader protein YTHDC2 was detected in an NSCLC cisplatin-resistant cell line (A549/DDP) using real-time fluorescence quantitative polymerase chain reaction (qPCR). YTHDC2 overexpression plasmids were constructed and transfected into A549/DDP and A549 cells respectively. We performed qPCR and western blot (WB) to detect changes in YTHDC2 and Id3 expression, and the effects of YTHDC2 overexpression on proliferation, apoptosis, invasion, and migration of drug-resistant cells were assessed by cell counting kit-8 (CCK-8), flow cytometry, and transwell and scratch assays. The m6A modification of Id3 by YTHDC2 was clarified by m6A-immunoprecipitation-PCR (m6A-IP-PCR) assay. RESULTS: The CLIPdb online database predicted that YTHDC2 might bind to Id3. The results of qPCR showed that YTHDC2 was downregulated in the NSCLC cisplatin-resistant cell line A549/DDP compared to the cisplatin-sensitive cell line A549. Overexpression of YTHDC2 increased the expression of Id3, and the methylation inhibitor 3-deazaadenosine abrogated the regulatory effect of YTHDC2 on Id3. YTHDC2 overexpression significantly inhibited A549/DDP cell proliferation, migration, and invasion, and promoted apoptosis by synergistically promoting the effects of Id3. m6A-IP-PCR analysis revealed that YTHDC2 could inhibit the m6A level of Id3 mRNA. CONCLUSIONS: To regulate the activity of Id3, YTHDC2 requires modifications to m6A, which ultimately inhibit cisplatin resistance in NSCLC.