Partial Beclin 1 silencing aggravates doxorubicin- and Fas-induced apoptosis in HepG2 cells.

ABSTRACT:

Aim

To investigate the role of Beclin 1 on the susceptibility of HepG2 cells to undergo apoptosis after anti-Fas antibody or doxorubicin treatment.

Methods

Beclin 1 silencing was achieved using RNA interference. DNA ploidy, the percentage of apoptotic cells and the mitochondrial membrane potential were assessed by flow cytometry. Levels of Beclin 1, Bcl-X(L) and cytochrome c, and the cleavage of poly (ADP-ribose) polymerase (PARP) were assayed by using Western blots.

Results

Beclin 1 expression decreased by 75% 72 h after Beclin 1 siRNA transfection. Partial Beclin 1 silencing significantly increased the percentage of subG1 cells 24 and 40 h after treatment with doxorubicin or anti-Fas antibody, respectively, and this potentiation was abrogated by treatment with a pan-caspase inhibitor. Partial Beclin 1 silencing also increased PARP cleavage, mitochondrial membrane depolarization and cytosolic cytochrome c. The pro-apoptotic consequences of partial Beclin 1 silencing were not associated with a decline in Bcl-X(L) expression.

Conclusion

Partial Beclin 1 silencing aggravates mitochondrial permeabilization and apoptosis in HepG2 cells treated with an anti-Fas antibody or with doxorubicin.

SUBMITTER: Daniel F 

PROVIDER: S-EPMC4087807 | biostudies-literature | 2006 May

REPOSITORIES: biostudies-literature