Stachydrine hydrochloride inhibits hepatocellular carcinoma progression via LIF/AMPK axis

Hepatocellular carcinoma (HCC) is not only one of the four highest malignancies, but also the principal reason of cancer-related death worldwide, yet no effective medication for anti-HCC is available. Stachydrine hydrochloride (SH), an alkaloid component in Panzeria alaschanica Kupr, exhibits potent antitumor activity in breast cancer. However, the anti-HCC effects of SH remain unknown.

Our study assessed the therapeutic effect of SH on HCC and tried to clarify the mechanisms by which it ameliorates HCC. No studies involving using SH for anti-HCC activity and molecular mechanism have been reported yet.

We examined the cell viability of SH on HCC cells by MTT assay. The effect of SH on cell autophagy in HCC cells was verified by Western blot and Immunofluorescence test. Flow cytometry was performed to assess cell-cycle arrest effects. Cell senescence was detected using β-Gal staining and Western blot, respectively. An inhibitor or siRNA of autophagy, i.e., CQ and si LC-3B, were applied to confirm the role of autophagy acted in the anti-cancer function of SH. Protein expression in signaling pathways was detected by Western blot. Besides, molecular docking combined with cellular thermal shift assay (CETSA) was used for analysis. Patient-derived xenograft (PDX) model were built to explore the inhibitory effect of SH in HCC in vivo.

In vitro studies showed that SH possessed an anti-HCC effect by inducing autophagy, cell-cycle arrest and promoting cell senescence. Specifically, SH induced autophagy with p62 and LC-3B expression. Flow cytometry analysis revealed that SH caused an obvious cell-cycle arrest, accompanied by the decrease and increase in Cyclin D1 and p27 levels, respectively. Additionally, SH induced cell senescence with the induction of p21 in HCC cell lines. Mechanistically, SH treatment down-regulated the LIF and up-regulated p-AMPK. Moreover, PDX model in NSG mice was conducted to support the results in vitro.

This study is the first to report the inhibitory function of SH in HCC, which may be due to the induction of autophagy and senescence. This study provides novel insights into the anti-HCC efficacy of SH and it might be a potential lead compound for further development of drug candidates for HCC.