title: Molecular mechanism of gossypol-induced cell growth inhibition and cell death of HT-29 human colon carcinoma cells.
abstract: Gossypol, a male contraceptive drug, has been demonstrated to have antiproliferative and antimetastatic effects on many kinds of cancer cells in vitro. HT-29 human carcinoma cell line is one of the most susceptible cell lines to gossypol-induced cell death. Here, it is shown that treatment of HT-29 cells with gossypol not only induces cell cycle arrest on the G0/G1 phase, but also induces apoptosis. With a serial of Western blot analysis, it is revealed that gossypol-induced cell cycle arrest is involved in P21 up-regulation and cyclin D1 down-regulation; gossypol-induced apoptosis triggers down-regulation of anti-apoptosis Bcl-2 members: Bcl-X(L), Bag-1 and Mcl-1, up-regulation of pro-apoptosis Bcl-2 member Bak, activation of caspase-3, -6, -7, -8, and -9, up-regulation of Apaf-1, release of cytochrome c (cyto-c) from mitochondria, and activation of both DFF45 and PARP. Taken together, gossypol-induced cell death initiates extensive alterations of cell cycle and apoptosis proteins. Gossypol-induced apoptosis of HT-29 cells is through first the mitochondrial pathway, then the death receptor pathway, and the mitochondria pathway is, at least in part, involved in cyto-c release.
authors.affiliation: Lombardi Cancer Center and Department of Oncology, Georgetown University Medical Center, Washington, DC 20007, USA. manchaoz@umich.edu
authors.forename: Manchao
authors.initials: M
authors.lastname: Zhang
authors.forename: Hongpeng
authors.initials: H
authors.lastname: Liu
authors.forename: Ribo
authors.initials: R
authors.lastname: Guo
authors.forename: Yan
authors.initials: Y
authors.lastname: Ling
authors.forename: Xiaojin
authors.initials: X
authors.lastname: Wu
authors.forename: Bihua
authors.initials: B
authors.lastname: Li
authors.forename: Peter P
authors.initials: PP
authors.lastname: Roller
authors.forename: Shaomeng
authors.initials: S
authors.lastname: Wang
authors.forename: Dajun
authors.initials: D
authors.lastname: Yang
mesh_terms: D017209:Apoptosis; D051017:Apoptosis Regulatory Proteins; D020169:Caspases / Q000378:metabolism; D002453:Cell Cycle / Q000187:drug effects; D016923:Cell Death; D003110:Colonic Neoplasms / Q000473:pathology; D019938:Cyclin D1 / Q000378:metabolism; D003574:Cytochrome c Group / Q000378:metabolism; D004789:Enzyme Activation; D006072:Gossypol / Q000494:pharmacology*; D019073:HT29 Cells; D006801:Humans; D011065:Poly(ADP-ribose) Polymerases / Q000378:metabolism; D011506:Proteins / Q000378:metabolism; D019253:Proto-Oncogene Proteins c-bcl-2 / Q000378:metabolism; D051020:bcl-X Protein
chemical_list: D051017:Apoptosis Regulatory Proteins; C494811:BCL2L1 protein, human; D003574:Cytochrome c Group; D011506:Proteins; D019253:Proto-Oncogene Proteins c-bcl-2; D051020:bcl-X Protein; C109664:caspase-activated DNase inhibitor; D019938:Cyclin D1; D011065:Poly(ADP-ribose) Polymerases; D020169:Caspases; D006072:Gossypol