Pseudomonas putida KT2440-induced RBM47 regulates non-small cell lung cancer stem cell properties and T cell-mediated...

Lung cancer (LC) remains a major cause of cancer-related mortality globally and is the most frequently diagnosed malignancy. Recent research has highlighted the role of intratumor microbiota in cancer pathogenesis. Studies have indicated a close association of Pseudomonas putida strain KT2440 with non-small cell LC (NSCLC) progression. However, the underlying mechanism of KT2440-induced NSCLC tumorigenesis is unknown. In this study, we aimed to investigate how Pseudomonas putida KT2440 influences non-small cell lung cancer stem cell (NSCL-CSC) properties and T cell-mediated antitumor activity.

RNA-binding motif protein 47 (RBM47) expression in NSCLC tumor samples and cell lines was examined via quantitative real-time polymerase chain reaction (qRT-PCR). N⁶-methyladenosine (m⁶A) modification of RBM47 was examined via methylated RNA immunoprecipitation (RIP)-PCR. In vitro and in vivo experiments were used to assess the effect of RBM47 on cancer stem cell (CSC) growth.

These experiments revealed that the KT2440 induced m⁶A, which enhanced the messenger RNA (mRNA) expression of RBM47, whereas methyltransferase-like 3 (METTL3) and YTHDF1-dependent m⁶A methylation decreased RBM47 expression in NSCLC. RBM47 was found to be downregulated in CSCs. Furthermore, it was found that RBM47 knockdown (KD) increased the self-renewal and tumorigenesis ability of NSCL-CSCs likely via the Wnt pathway. Moreover, RBM47 enhanced T-cell proliferation and cytotoxicity by destabilizing the programmed death-ligand 1 (PD-L1) mRNA via 3'-untranslated region (3'-UTR) binding.

The RBM47 induction pathway, influenced by KT2440-induced m6A modification, modulates NSCL-CSC properties and T cell-mediated antitumor activity, supporting RBM47 as a novel therapeutic target against LC.