Heteronemin suppresses EGF‑induced proliferation through the PI3K/PD‑L1 signaling pathways in cholangiocarcinoma

Epidermal growth factor (EGF) binds with its surface receptor to stimulate gene expression and cancer cell proliferation. EGF stimulates cancer cell growth via phosphoinositide 3‑kinase (PI3K) and programmed cell death ligand 1 (PD‑L1) pathways. As an integrin αvβ3 antago‑ nist, heteronemin exhibits potent cytotoxic effects against cancer cells. It inhibits critical signal transduction pathways promoted by the EGF. In the current study, EGF‑induced signal activation and proliferative effects were investigated in cholangiocarcinoma cells and its molecular targets using qPCR and western blotting analyses. In addition, cell viability assays were performed to assess the growth effects of EGF and heteronemin. Heteronemin reversed the effects of EGF and was further enhanced by blockage of PI3K's activity. In summary, EGF stimulates cholangiocarcinoma cell growth. On the other hand, heteronemin inhibited PI3K activation and PD‑L1 expression to reverse the stimulative effects of EGF‑induced gene expression and proliferation in cholangiocarcinoma cells.