RP3-340N1.2 Knockdown Suppresses Proliferation and Migration by Downregulating IL-6 in Non-Small Cell Lung CancerOA

Objectives:Non-small cell lung cancer(NSCLC)remains a leading cause of cancer-related mortality,with limited understanding of lncRNA-driven mechanisms in tumor progression.This study aimed to identify differentially expressed lncRNAs in NSCLC tissues and elucidate the functional role of the significantly upregulated RP3-340N1.2 in promoting malignancy.Methods:RNA sequencing was used to screen dysregulated lncRNAs.RP3-340N1.2 was functionally characterized via gain/loss-of-function assays in NSCLC cells,assessing proliferation,migration,and macrophage polarization.Mechanisms of interleukin 6(IL-6)regulation were explored using cytokine profiling,Actinomycin D assays,and RNA Immunoprecipitation(RIP)assays to study RP3-340N1.2 interactions with zinc finger CCCH-type containing 12A(ZC3H12A)and IL-6 mRNA.Results:RP3-340N1.2 was upregulated in NSCLC tissues and cells.Functional assays demonstrated that RP3-340N1.2 knockdown suppressed NSCLC cell proliferation/migration and reduced macrophage polarization toward tumor-associated phenotypes.Mechanistically,RP3-340N1.2 knockdown promoted IL-6 mRNA degradation,as supported by reduced IL-6 levels and accelerated mRNA decay.Further RIP assays revealed that RP3-340N1.2 interacts with ZC3H12A,an RNA-binding protein previously reported to degrade IL-6 mRNA,and that RP3-340N1.2 knockdown enhanced ZC3H12A binding to IL-6 mRNA.Consequently,RP3-340N1.2 knockdown in carcinoma cells attenuated IL-6-mediated tumor-promoting effects,including tumor cell proliferation and migration.Importantly,these effectswere observed not only in a direct carcinoma cell culturing system but also when carcinoma cells were exposed to conditioned medium from co-culturing RP3-340N1.2-knockdown tumor cells andmacrophages.Conclusion:RP3-340N1.2 drivesNSCLC malignancy by stabilizing IL-6 mRNA;its inhibition offers a potential therapeutic strategy to disrupt tumor-promoting interactions.