Characterization of mitochondria in cisplatin-resistant human ovarian carcinoma cells.

One of the mechanisms of cisplatin cell cytotoxicity is the mitochondria-associated induction of apoptosis. The morphological or functional change of mitochondria in cisplatin-resistant cells has already been reported. Herein we present additional data describing the mitochondrial genomic and functional changes in cisplatin- resistant cells. Cisplatin increased the level of apoptotic cells in cisplatin-sensitive human ovarian carcinoma OV 2008 and C13 cells by 3.90+/-1.01 (SD; N=3) (p<0.01)-fold and 2.03+/-0.20 (SD; N=3) (p<0.01)-fold compared to the basal apoptotic level. This indicates a lower level induction of apoptosis by 50% in cisplatin-resistant OV 2008/C13 *5.25 variant (C13) cells. In both cell types, cisplatin cytotoxicity is mostly inhibited by the caspase-9 inhibitor as well as the caspase-3 inhibitor, Ac-DEVD-CHO, suggesting that the mitochondrial downstream event was functioning well in both the C13 cells and in OV 2008 cells. Mitochondrial transmembrane potential (DeltaPsim) determined by flow cytometry using DiOC6-stained cells revealed a significant depolarization of C13 cells as compared to OV 2008 cells. Treatment of these cells with cisplatin or hydrogen peroxide induces complete mitochondrial DNA damage in OV 2008 cells, while only partial DNA-destruction is observed in C13 cells, strongly suggesting that mitochondria are resistant to cisplatin and oxidative stress response. Continuous oxygen consumption of these cells monitored by a multi-channel dissolved oxygen meter is 1.70-fold higher in OV 2008 cells than C13 cells and the oxygen consumption was decreased by 30% in C13 cells, suggesting mitochondrial respiratory malfunction in these cells. The hypothesis generated here is that mitochondrial DNA resistance to cisplatin and oxidative stress response might be one of the main characteristics concerning the lower level of apoptosis induced by cisplatin. However, the mechanism by which the mitochondrial DNA encoded molecule is involved in cisplatin resistance remains to be determined.

[1]  I. Chang,et al.  Resistance of Mitochondrial DNA-depleted Cells against Cell Death , 2004, Journal of Biological Chemistry.

[2]  Tadao Tanaka,et al.  Enhancement of sensitivity to cisplatin by orobol is associated with increased mitochondrial cytochrome c release in human ovarian carcinoma cells. , 2003, Gynecologic oncology.

[3]  S. Isonishi,et al.  Mitochondria in platinum resistant cells. , 2001, Human cell.

[4]  G. Cohen,et al.  Apoptotic death sensor: an organelle's alter ego? , 2001, Trends in pharmacological sciences.

[5]  P. Majumder,et al.  Targeting of Protein Kinase C to Mitochondria in the Oxidative Stress Response 1 , 2001 .

[6]  W. Earnshaw,et al.  Induction of apoptosis by cancer chemotherapy. , 2000, Experimental cell research.

[7]  A. Grothey,et al.  Cisplatin resistance and oncogenes - a review , 2000, Anti-cancer drugs.

[8]  Keshav K. Singh,et al.  Mitochondrial DNA determines the cellular response to cancer therapeutic agents , 1999, Oncogene.

[9]  J. Meléndez-Zajgla,et al.  Mitochondrial changes during the apoptotic process of HeLa cells exposed to cisplatin , 1999, Biochemistry and molecular biology international.

[10]  B. Liang,et al.  Increased sensitivity to cis-diamminedichloroplatinum induced apoptosis with mitochondrial DNA depletion , 1998, Cell Death and Differentiation.

[11]  M. Poirier,et al.  Preferential formation and decreased removal of cisplatin-DNA adducts in Chinese hamster ovary cell mitochondrial DNA as compared to nuclear DNA. , 1997, Mutation research.

[12]  W. Dalton,et al.  Selection for drug resistance results in resistance to Fas-mediated apoptosis. , 1997, Blood.

[13]  D. Gustafson,et al.  A new cellular target for mitomycin C: a case for mitochondrial DNA. , 1997, Oncology research.

[14]  I. Herr,et al.  Involvement of the CD95 (APO–1/Fas) receptor/ligand system in drug–induced apoptosis in leukemia cells , 1996, Nature Medicine.

[15]  Guido Kroemer,et al.  The biochemistry of programmed cell death , 1995, FASEB journal : official publication of the Federation of American Societies for Experimental Biology.

[16]  V. Bohr,et al.  Repair of mitochondrial DNA after various types of DNA damage in Chinese hamster ovary cells. , 1992, Carcinogenesis.

[17]  P. Andrews,et al.  Mitochondrial defects in cis-diamminedichloroplatinum(II)-resistant human ovarian carcinoma cells. , 1992, Cancer research.

[18]  B. Teicher,et al.  Involvement of protein kinase C in phorbol ester-induced sensitization of HeLa cells to cis-diamminedichloroplatinum(II). , 1990, The Journal of biological chemistry.

[19]  S. Howell,et al.  Increased sensitivity to cis-diamminedichloroplatinum(II) in human ovarian carcinoma cells in response to treatment with 12-O-tetradecanoylphorbol 13-acetate. , 1990, The Journal of biological chemistry.

[20]  M. D. Topal,et al.  Insertion and extension of acyclic, dideoxy, and ara nucleotides by herpesviridae, human alpha and human beta polymerases. A unique inhibition mechanism for 9-(1,3-dihydroxy-2-propoxymethyl)guanine triphosphate. , 1988, The Journal of biological chemistry.

[21]  J. Aprille,et al.  Relation of mevalonate synthesis to mitochondrial ubiquinone content and respiratory function in cultured neuroblastoma cells. , 1985, The Journal of biological chemistry.