PPDPF promotes lung adenocarcinoma progression via inhibiting apoptosis and NK cell-mediated cytotoxicity through STAT3.

Lung cancer is the most common malignancy and the leading cause of cancer death worldwide, and lung adenocarcinoma (LUAD) is the most prevalent subtype. Considering the emergence of resistance to therapies, it is urgent to develop more effective therapies to improve the prognosis. Here we reported that pancreatic progenitor cell differentiation and proliferation factor (PPDPF) deficiency inhibited LUAD development both in vitro and in vivo. Mechanistically, PPDPF induces hyperactive STAT3 by interfering STAT3-PTPN1 interaction. Activated STAT3 promoted BMPR2 transcription, which further inhibited apoptosis. Moreover, PPDPF reduced NK cell infiltration and activation to develop an immunosuppressive microenvironment, which was also mediated by STAT3. Furthermore, we identified that the expression of PPDPF was positively correlated with the malignant features of LUAD, as well as BMPR2 and p-STAT3 level in clinical samples. Therefore, our study suggests that PPDPF positively regulates BMPR2 expression and facilitates immune escape via regulating STAT3 activity, providing a potential therapy target for LUAD.