Hernandezine induces autophagic cell death in human pancreatic cancer cells via activation of the ROS/AMPK signaling pathway

Abstract

Hernandezine (Her) is a bisbenzylisoquinoline alkaloid extracted from the traditional Chinese herbal medicine Thalictrum glandulosissimum. Evidence shows that Her is a natural agonist of adenosine monophosphate (AMP)-activated protein kinase (AMPK) and induces apoptosis and autophagy in tumor cells. In this study, we investigated the role of autophagy in Her-induced cell death in human pancreatic cancer cell lines. We showed that Her dose-dependently suppressed cell proliferation, promoted autophagy and induced autophagic death in pancreatic ductal adenocarcinoma (PDAC) cell lines Capan-1 and SW1990. The IC50 values of Her in inhibition of Capan-1 and SW1990 cells were 47.7 μM and 40.1 μM, respectively. Immunoblotting showed that Her (1−40 μM) promoted the conversion of LC3-I to LC3-II, and Her exerted concentration-dependent and time-dependent effects on autophagy activation in PDAC cells. In transmission electron microscopy and fluorescence image analysis, we found that autophagic vacuoles were significantly increased in Her-treated cells. Knockdown of ATG5, a key gene in the autophagy pathway, alleviated the activation of autophagy by Her. These results demonstrated that Her induced autophagy in PDAC cells. Intensely activated autophagy could promote cell death. The autophagy inhibitors, BafA1 and HCQ significantly inhibited Her-induced cell death, implying that Her induced autophagic cell death in PDAC cells. Moreover, we showed that Her activated autophagy by increasing the phosphorylation of AMPK and decreasing the phosphorylation of mTOR/p70S6K. Knockdown of AMPKα relieves the autophagic cell death induced by Her. Furthermore, Her concentration-dependently enhanced reactive oxygen species (ROS) generation in PDAC cells. Antioxidants could reduce the phosphorylation of AMPK and suppress autophagic cell death induced by Her. Our study provides evidence for the development of Her as a therapeutic agent for the treatment of pancreatic cancer.

Nutrient restriction-activated Fra-2 promotes tumor progression via IGF1R in miR-15a downmodulated pancreatic ductal adenocarcinoma

“…4f, h ). Moreover, it is reported that intensely activated autophagy could promote cell death in PDAC 47 ; thus, we could speculate that IGF1R overexpression in nutrient deprivation could also exert a protective function in neoplastic cells, preventing an excess of autophagy. Further investigations are needed, but it is conceivable that the described mechanism could play different roles in a context-dependent manner, according to the stage of PDAC progression.…”

NUSAP1 promotes pancreatic ductal adenocarcinoma progression by drives the epithelial-mesenchymal transition and reduces AMPK phosphorylation

“…Although there is evidence suggesting that AMPK might help cancer cells survive under certain circumstances, there is more support in the literature for the notion that AMPK acts as a tumor suppressor by leading to cell growth inhibition and cell cycle arrest [ 40 ]. Song’s study revealed that Hernandezine activates autophagy and induces autophagic cell death in PDAC cells by promoting ROS generation, activating the AMPK signaling pathway and inhibiting the mTOR/p70S6K signaling pathway [ 41 ]. Notably, activation of AMPK is dependent on the phosphorylation of AMPKα at Thr-172.…”

A new glance at autophagolysosomal-dependent or -independent function of transcriptional factor EB in human cancer

“…Due to its limited selectivity, CQ targets many characteristics of lysosomes, including essential functions, at the same time, which highlights the importance of researching specific targets in the autophagylysosomal system [57]. Recently, our group showed that Hernandezine (Her) activates the ROS/AMPK signaling pathway in a concentration-dependent manner and thus induces autophagic cell death in human pancreatic cancer cells [58]. This study provided support for the application of autophagic drugs to treat pancreatic cancer, demonstrated the importance and feasibility of autophagy-related cancer therapies, and opened the door to research into therapeutic strategies by regulating key autophagy pathways.…”