Mechanism of sinomenine-induced apoptosis of human liver cancer cells via GRP78 membrane translocation.

BACKGROUND

Sinomenine (SIN), the main active ingredient of Sinomenium acutum (Thunb.) Rehd. et Wils. Rhizomes, exhibits sensitive pharmacological activity against liver cancer. To elucidate the underlying mechanism, in vitro studies were conducted on human hepatocellular carcinoma (HCC) cell lines SMMC-7721 and HepG-2.

METHODS AND

RESULTS

SIN's effects on cell viability, apoptosis, and expression of apoptosis-related genes and proteins were assessed. Immunofluorescence staining and Western blotting evaluated GRP78 cell-surface translocation and its role in apoptosis. SMMC-7721 cells were transfected with a GRP78 overexpression plasmid or treated with a GRP78 antibody to confirm the functional relevance of membrane GRP78 with SIN-induced apoptosis. Additionally, we examined the involvement of reactive oxygen species (ROS) in GRP78 translocation. In the results, SIN induced apoptosis in a dose- and time-dependent manner, and mainly through the endoplasmic reticulum (ER) apoptosis pathway. By increasing cellular ROS levels, the translocation of GRP78 from cytoplasm to cell membrane can be induced by SIN, and this translocation contributed to apoptosis.

CONCLUSIONS

SIN promoted the apoptosis of HCC cells by inducing GRP78 membrane translocation, mediated by increased ROS levels. This study provides new insight into SIN-induced GRP78 targeted antitumor therapy, which has important theoretical significance and application value.