RBM15 facilitates laryngeal squamous cell carcinoma progression by regulating TMBIM6 stability through IGF2BP3 dependent

Abstract

Background: Laryngeal cancer has the highest mortality rate among head and neck tumours. RNA N6-methyladenosine (m6A) is the most plentiful and variable in mammalian mRNA. Yet, the m6A regulatory mechanism underlying the carcinogenesis or progression of LSCC remains poorly understood. Methods: The m6A RNA methylation quantification kit was used to detect tissue methylation levels. m6A microarray analysis, mRNA transcriptomic sequencing (mRNA-seq), and proteomics were used to determine RBM15, TMBIM6, and IGF2BP3. Immunohistochemical (IHC), quantitative real-time PCR (qRT-PCR) and Western blot were used to investigate RBM15, TMBIM6, and IGF2BP3 expression in tissue samples and cell lines. The biological effects of RBM15 were detected both in vitro and in vivo. The combination relationship between RBM15/IGF2BP3 and TMBIM6 was verified by RNA immunoprecipitation (RIP) assay, Methylated RNA immunoprecipitation sequencing (MeRIP-seq), RNase Mazf, and luciferase report assay. RNase Mazf was used to determine the methylation site on TMBIM6 mRNA. Hoechst staining assay was used to confirm the apoptotic changes. The actinomycin D verified TMBIM6 stability. Results: The global mRNA m6A methylation level significantly increased in LSCC patients. RBM15, as a “writer” of methyltransferase, was significantly increased in LSCC and was associated with unfavorable prognosis. The knockdown of RBM15 reduced the proliferation, invasion, migration, and apoptosis of LSCC both in vitro and in vivo. The results were reversed after overexpressing RBM15. Mechanically, TMBIM6 acted as a downstream target of RBM15-mediated m6A modification. Furthermore, RBM15-mediated m6A modification of TMBIM6 mRNA enhanced TMBIM6 stability through IGF2BP3-dependent. Conclusion: Our results revealed the essential roles of RBM15 and IGF2BP3 in m6A methylation modification in LSCC, thus identifying a novel RNA regulatory mechanism.

N6-Methyladenosine Methylation Regulator RBM15 is a Potential Prognostic Biomarker and Promotes Cell Proliferation in Pancreatic Adenocarcinoma

“…Previous study has shown that RBM15 could promote invasion and accelerate the malignant progression of LSCC (Wang et al, 2021). In addition, high expression of RBM15 affects the prognosis of HBV-associated hepatocellular carcinoma patients (Fang and Chen, 2020).…”

“…"Readers" are m6A binding proteins, including YTHDC1/2, YTHDF1/2/3, IGF2BP1/2/3, HNRNPG, HNRNPC, and HNRNPA2B1 (Bi et al, 2019). RBM15, as a "Writer" of m6A, has been shown to play an important role in the progression of LSCC in previous study (Wang et al, 2021). Although RBM15 has been extensively studied in LSCC, its roles in pan-cancer and whether it can be used as a biomarker remains unclear.…”

“…In addition, it also functions as an mRNA export factor, stimulating export and expression of RTE-containing mRNAs (Lindtner et al, 2006;Zolotukhin et al, 2009). Study has shown that RBM15 promoted the progression of laryngeal squamous cell carcinoma (LSCC) by mediating the m6A modification of TMBIM6 mRNA (Wang et al, 2021). Although the role of RBM15 in LSCC is well understood, it's functions in human pan-cancer remains largely unknown.…”