Ginsenoside Rg3 enhances the anti-proliferative activity of erlotinib in pancreatic cancer cell lines by downregulation of EGFR/PI3K/Akt signaling pathway

Erlotinib has shown activity in the management of pancreatic cancer. However, the benefit of EGFR blockade is limited due to EGFR independent PI3K/Akt signaling pathway. Studies have reported that Ginsenoside Rg3 strongly inhibited PI3K-Akt signaling pathway of many carcinomas. We aimed to investigate the activity of Ginsenoside Rg3 to sensitize erlotinib in treating pancreatic cancer in vitro and in vivo. Human pancreatic cancer cell lines BxPC-3 and AsPC-1 were used. Cell proliferation and colony formation assay, Annexin V/PI apoptosis analysis, Western blot analysis, immunohistochemistry and in vivo study were carried out. Ginsenoside Rg3 enhanced the anti-proliferative effects of erlotinib in BxPC-3 and AsPC-1 pancreatic cancer cells and xenograft. Ginsenoside Rg3 enhanced erlotinib-induced apoptosis and increased caspase-3,9 and PARP cleavage expression levels. Erlotinib/Ginsenoside Rg3 treatment decreased the levels of p-EGFR, p-PI3K, and p-Akt expression significantly. Ginsenoside Rg3 could enhance the efficacy of erlotinib to inhibit the proliferation of pancreatic cancer cells via induction of apoptosis and downregulation of the EGFR/PI3K/AKT pathway.