Grape seed extract induces anoikis and caspase-mediated apoptosis in human prostate carcinoma LNCaP cells: possible role of ataxia telangiectasia mutated-p53 activation.
Prostate cancer is the second leading cancer diagnosed in elderly males in the Western world. Epidemiologic studies suggest that dietary modifications could be an effective approach in reducing various cancers, including prostate cancer, and accordingly cancer-preventive efficacy of dietary nutrients has gained increased attention in recent years. We have recently shown that grape seed extract (GSE) inhibits growth and induces apoptotic death of advanced human prostate cancer DU145 cells in culture and xenograft. Because prostate cancer is initially an androgen-dependent malignancy, here we used LNCaP human prostate cancer cells as a model to assess GSE efficacy and associated mechanisms. GSE treatment of cells led to their detachment within 12 hours, as occurs in anoikis, and caused a significant decrease in live cells mostly due to their apoptotic death. GSE-induced anoikis and apoptosis were accompanied by a strong decrease in focal adhesion kinase levels, but an increase in caspase-3, caspase-9, and poly(ADP-ribose) polymerase cleavage; however, GSE caused both caspase-dependent and caspase-independent apoptosis as evidenced by cytochrome c and apoptosis-inducing factor release into cytosol. Additional studies revealed that GSE causes DNA damage-induced activation of ataxia telangiectasia mutated kinase and Chk2, as well as p53 Ser(15) phosphorylation and its translocation to mitochondria, suggesting this to be an additional mechanism for apoptosis induction. GSE-induced apoptosis, cell growth inhibition, and cell death were attenuated by pretreatment with N-acetylcysteine and involved reactive oxygen species generation. Together, these results show GSE effects in LNCaP cells and suggest additional in vivo efficacy studies in prostate cancer animal models.
Kaur
Manjinder
M
Department of Pharmaceutical Sciences, School of Pharmacy, University of Colorado Health Sciences Center, 4200 East Ninth Avenue, Box C238, Denver, CO 80262. Chapla.Agarwal@uchsc.edu.
Agarwal
Rajesh
R
Agarwal
Chapla
C
D000111:Acetylcysteine / Q000378:metabolism / Q000494:pharmacology; D023102:Anoikis / Q000187:drug effects*; D016588:Anticarcinogenic Agents / Q000494:pharmacology*; D017209:Apoptosis / Q000187:drug effects; D051033:Apoptosis Inducing Factor / Q000378:metabolism; D064007:Ataxia Telangiectasia Mutated Proteins; D020169:Caspases / Q000378:metabolism* / Q000494:pharmacology; D018797:Cell Cycle Proteins / Q000235:genetics / Q000378:metabolism*; D064447:Checkpoint Kinase 2; D045304:Cytochromes c / Q000378:metabolism; D004268:DNA-Binding Proteins / Q000235:genetics / Q000378:metabolism*; D051417:Focal Adhesion Kinase 1 / Q000378:metabolism; D006657:Histones / Q000378:metabolism; D006801:Humans; D008297:Male; D010936:Plant Extracts / Q000378:metabolism / Q000494:pharmacology*; D011065:Poly(ADP-ribose) Polymerases / Q000378:metabolism; D011471:Prostatic Neoplasms / Q000188:drug therapy / Q000378:metabolism*; D017346:Protein Serine-Threonine Kinases / Q000235:genetics / Q000378:metabolism*; D017382:Reactive Oxygen Species / Q000378:metabolism; D014407:Tumor Cells, Cultured; D016159:Tumor Suppressor Protein p53 / Q000378:metabolism*; D025521:Tumor Suppressor Proteins / Q000235:genetics / Q000378:metabolism*
D016588:Anticarcinogenic Agents; D051033:Apoptosis Inducing Factor; D018797:Cell Cycle Proteins; D004268:DNA-Binding Proteins; D006657:Histones; D010936:Plant Extracts; D017382:Reactive Oxygen Species; D016159:Tumor Suppressor Protein p53; D025521:Tumor Suppressor Proteins; D045304:Cytochromes c; D011065:Poly(ADP-ribose) Polymerases; D064447:Checkpoint Kinase 2; D051417:Focal Adhesion Kinase 1; C496050:PTK2 protein, human; C576324:ATM protein, human; D064007:Ataxia Telangiectasia Mutated Proteins; C578634:CHEK2 protein, human; D017346:Protein Serine-Threonine Kinases; D020169:Caspases; D000111:Acetylcysteine