Allicin regulates Sestrin2 ubiquitination to affect macrophage autophagy and senescence, thus inhibiting the growth of hepatoma cells

Abstract

Background: Allicin regulates macrophage autophagy and senescence, and inhibits hepatoma cell growth. This study investigated the mechanism by which allicin inhibits the growth of hepatoma cells.

Methods: Hepa1-6 mouse hepatoma cells were subcutaneously injected into C57BL/6 J mice to construct a tumor transplantation model. Macrophages were cultured with the supernatant of hepatoma cells to construct a cell model. The levels of mRNA and proteins and the level of Sestrin2 ubiquitination were measured by RTqPCR, immunofluorescence and Western blotting. The levels of autophagy-related factors and the activity of senescence-associated β-galactosidase were determined by kits, and protein stability was detected by cycloheximide (CHX) tracking.

Results: Data analysis of clinical samples revealed that RBX1 was highly expressed in tumor tissues, while Sestrin2 was expressed at low levels in tumor tissues. Allicin can promote the expression of the autophagy-related proteins LC3 and Beclin-1 in tumor macrophages and inhibit the expression of the aging-related proteins p16 and p21, thus promoting autophagy in macrophages and inhibiting cell senescence. Moreover, allicin can inhibit the expression of RBX1, thereby reducing the ubiquitination of Sestrin2, enhancing the stability of Sestrin2, activating autophagy in tumor macrophages and inhibiting senescence. In addition, allicin treatment inhibited the proliferation and migration of hepatoma carcinoma cells cocultured with macrophages and significantly improved the development of liver cancer in mice.

Conclusion: Allicin can affect the autophagy of macrophages and restrain the growth of hepatoma cells by regulating the ubiquitination of Sestrin2.

Keywords: Allicin; Autophagy; Hepatocellular carcinoma; Macrophages; Sestrin2.