IGF2BP1 enhances the stability of SIK2 mRNA through m6A modification to promote non-small cell lung cancer progression

Abstract

Background: Non-small cell lung cancer (NSCLC) is a significant public health concern globally. Evidence suggests that Salt-inducible kinase 2 (SIK2) is differentially expressed across various cancers and is also implicated in cancer progression. Despite this, the precise function of SIK2 in NSCLC is yet to be elucidated and requires further investigation.

Methods: SIK2 expression was evaluated in both HBEC and NSCLC cells, utilizing quantitative real-time PCR (qRT-PCR) and Western blot (WB) analyses. Furthermore, to identify the influence of SIK2 on cell proliferation, migration, invasion, and apoptosis, a range of techniques were employed. To evaluate N6-methyladenosine (m⁶A) modification levels of total RNA and SIK2 within cells, RNA m⁶A colorimetry and methylated RNA immunoprecipitation (MeRIP) techniques were employed. Additionally, to confirm the interaction between SIK2 and insulin-like growth factor 2 mRNA-binding protein 1 (IGF2BP1), bioinformatics analysis was executed, and the results were validated through RIP. The stability of SIK2 mRNA was determined using actinomycin D experiment. Furthermore, to validate the in vivo functionality of SIK2, a subcutaneous transplantation tumor model was established in nude mice.

Results: In this study, upregulation of SIK2 in NSCLC cells was observed. Overexpression of SIK2 was found to lead to promotion of cell proliferation, migration, invasion, and suppression of the Hippo/yes-associated protein (YAP) pathway, while inhibiting apoptosis. RIP analysis showed that IGF2BP1 protein interacted with SIK2 mRNA. Knockdown of IGF2BP1 decreased mRNA stability and m⁶A modification levels of SIK2. Additionally, knockdown of IGF2BP1 resulted in inhibition of cell proliferation, migration, invasion, suppression of the Hippo/YAP pathway, and promoting apoptosis. Overexpression of SIK2 overturned the impact of IGF2BP1 on NSCLC cells, which was then confirmed through in vivo experiments.

Conclusion: IGF2BP1 stabilized SIK2 mRNA through m⁶A modification to promote NSCLC progression, potentially offering new diagnostic and therapeutic insights for NSCLC.

Keywords: Insulin-like growth factor 2 mRNA-binding protein 1; Methylated RNA immunoprecipitation; Non-small cell lung cancer; Salt‐inducible kinase 2.