TGFBI promotes EMT and perineural invasion of pancreatic cancer via PI3K/AKT pathway.

Pancreatic cancer is a highly lethal malignancy, and perineural invasion (PNI) is a common pathological feature that significantly contributes to poor prognosis. Our research identified TGFBI as a key player in PNI development. The expression of TGFBI in tissue and cancer cells were detected by RT-qPCR, Western blot, Immunohistochemistry, and ELISA. The localization of TGFBI in cells was analyzed by Immunofluorescence staining (IF). The neural invasion ability of cancer cells were assessed by in vitro neural invasion model. Moreover, Western blot was used to investigate epithelial-mesenchymal transition (EMT) markers and PI3K/AKT pathway markers to elucidate the underlying mechanisms. Finally, an in vivo neural invasion model was used to verify the tumorigenic ability of the cancer cells in the sciatic nerve. Our findings highlight that TGFBI is up-regulated in PNI tissue and significantly correlates with poor prognosis in pancreatic cancer patients. Based on in vitro experiments, knockdown of TGFBI reduced neural invasion, as well as EMT, whereas rTGFBI exhibited the reverse effect. Knockdown of TGFBI reduced PI3K/AKT phosphorylation in Capan-2 and CFPAC-1. Moreover, PI3K inhibitor LY294002 was observed to counteract the effects of TGFBI on neural invasion, and EMT in Capan-2 and CFPAC-1. In vivo, knockdown of TGFBI inhibited tumor formation in the sciatic nerve of mice. Finally, we confirmed TGFBI as potential biomarker for PNI and prognosis of pancreatic cancer. Collectively, we concluded that TGFBI activates the PI3K-AKT pathway in pancreatic cancer cells, ultimately promoting EMT and leading to PNI.