Ag85B inhibits autophagy and promotes apoptosis in Hodgkin lymphoma cells via the PI3K/AKT/mTOR pathway
CHENG Yongfeng
SHEN Yiping
FAN Chunyan
WANG Xuemei
YU Xia
MAIMAITI Gulibaha
JIA Jipeng
YAN Mei
Abstract：Objective To investigate the effect of Mycobacterium tuberculosis antigen Ag85B on autophagy and apoptosis in Hodgkin lymphoma(HL)cells,and to explore the underlying mechanisms.Methods Human HL cells(L-428)were divided into five groups:L-428,L-428+Ag85B(Ag85B at concentrations of 1,2,4,and 8 μg/mL).Western blot was used to detect the expression of LC3,p62,Beclin-1,ATG14,PI3K,AKT,mTOR,p-PI3K,p-AKT,p-mTOR,PARP,and Cleaved caspase-8 proteins in the cells.Apoptosis was measured using an apoptosis kit,and cell cycle distribution was analyzed by flow cytometry.Autophagic vesicles were observed by transmission electron microscopy(TEM).qRT-PCR was performed to measure mRNA levels of LC3,Beclin-1,and caspase-8.Results The expression of LC3 protein in the L-428+Ag85B groups was lower than in the L-428 group,and p62 expression was higher,with the most significant difference observed at 4 μg/mL Ag85B(P＜0.05).Western blot analysis showed that in the Ag85B-treated groups,the phosphorylation protein expression ratio of p-PI3K/PI3K,p-AKT/AKT,and p-mTOR/mTOR was higher than in the control group,while LC3,Beclin-1,and ATG14 expression levels were lower(P＜0.05).TEM images revealed reduced autophagosome formation in Ag85B-treated cells.Apoptosis assays showed significantly higher early and late apoptosis rates in Ag85B-treated cells compared to controls(P＜0.05),with elevated levels of cleaved caspase-8 and PARP expression.Flow cytometry revealed cell cycle arrest at the S phase in the Ag85B group(P＜0.05).Western blot analysis showed increased expression of p-mTOR after Ag85B treatment,while co-treatment with LY294002(PI3K/AKT inhibitor)reduced p-mTOR expression,increased LC3 and Beclin-1 mRNA expression,and decreased caspase-8 mRNA expression(P＜0.05).Conclusions Ag85B inhibits autophagy and promotes apoptosis in HL tumor cells by blocking the cell cycle at the S phase.The mechanism underlying this effect involves the modulation of the PI3K/AKT/mTOR pathway.
Keywords：Hodgkin lymphomaAg85BAutophagyApoptosisPI3K/AKT/mTOR
Publication Date：2025-06-20
Online Publishing Date：2025-08-15(First online date of this platform, not the publication date of the document)
Pages：7( 241-247 )