1. Partial Beclin 1 silencing aggravates doxorubicin- and Fas-induced apoptosis in HepG2 cells
- Author
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Agnès Legrand, Fanny Daniel, Nathalie Vadrot, Dominique Bernuau, Dominique Pessayre, and Veronique Descatoire
- Subjects
Carcinoma, Hepatocellular ,Blotting, Western ,bcl-X Protein ,Apoptosis ,Biology ,Transfection ,Permeability ,Flow cytometry ,Antibodies, Monoclonal, Murine-Derived ,RNA interference ,Cell Line, Tumor ,polycyclic compounds ,medicine ,Gene silencing ,Humans ,Doxorubicin ,Gene Silencing ,RNA, Messenger ,RNA, Small Interfering ,Antibiotics, Antineoplastic ,medicine.diagnostic_test ,Liver Neoplasms ,Gastroenterology ,Antibodies, Monoclonal ,Cytochromes c ,Membrane Proteins ,General Medicine ,DNA, Neoplasm ,Flow Cytometry ,digestive system diseases ,Cell biology ,Gene Expression Regulation, Neoplastic ,Basic Research ,Membrane protein ,Hepg2 cells ,Mitochondrial Membranes ,Cancer research ,Beclin-1 ,RNA Interference ,Apoptosis Regulatory Proteins ,medicine.drug - Abstract
To investigate the role of Beclin 1 on the susceptibility of HepG2 cells to undergo apoptosis after anti-Fas antibody or doxorubicin treatment.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.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.Partial Beclin 1 silencing aggravates mitochondrial permeabilization and apoptosis in HepG2 cells treated with an anti-Fas antibody or with doxorubicin.
- Published
- 2006