TY - JOUR
T1 - Therapeutic targeting of ATP7B in ovarian carcinoma
AU - Mangala, Lingegowda S.
AU - Zuzel, Vesna
AU - Schmandt, Rosemarie
AU - Leshane, Erik S.
AU - Halder, Jyotsna B.
AU - Armaiz-Pena, Guillermo N.
AU - Spannuth, Whitney A.
AU - Tanaka, Takemi
AU - Shahzad, Mian M.K.
AU - Lin, Yvonne G.
AU - Nick, Alpa M.
AU - Danes, Christopher G.
AU - Lee, Jeong Won
AU - Jennings, Nicholas B.
AU - Vivas-Mejia, Pablo E.
AU - Wolf, Judith K.
AU - Coleman, Robert L.
AU - Siddik, Zahid H.
AU - Lopez-Berestein, Gabriel
AU - Lutsenko, Svetlana
AU - Sood, Anil K.
PY - 2009/6/1
Y1 - 2009/6/1
N2 - Purpose: Resistance to platinum chemotherapy remains a significant problem in ovarian carcinoma. Here, we examined the biological mechanisms and therapeutic potential of targeting a critical platinum resistance gene, ATP7B, using both in vitro and in vivo models. Experimental Design: Expression of ATP7A and ATP7B was examined in ovarian cancer cell lines by real-time reverse transcription-PCR and Western blot analysis. ATP7A and ATP7B gene silencing was achieved with targeted small interfering RNA (siRNA) and its effects on cell viability and DNA adduct formation were examined. For in vivo therapy experiments, siRNA was incorporated into the neutral nanoliposome 1,2-dioleoyl-sn-glycero-3-phosphatidylcholine (DOPC). Results: ATP7A and ATP7B genes were expressed at higher levels in platinum-resistant cells compared with sensitive cells; however, only differences in ATP7B reached statistical significance. ATP7A gene silencing had no significant effect on the sensitivity of resistant cells to cisplatin, but ATP7B silencing resulted in 2.5-fold reduction of cisplatin IC50 levels and increased DNA adduct formation in cisplatin-resistant cells (A2780-CP20 and RMG2). Cisplatin was found to bind to the NH2-terminal copper-binding domain of ATP7B, which might be a contributing factor to cisplatin resistance. For in vivo therapy experiments, ATP7B siRNA was incorporated into DOPC and was highly effective in reducing tumor growth in combination with cisplatin (70-88% reduction in both models compared with controls). This reduction in tumor growth was accompanied by reduced proliferation, increased tumor cell apoptosis, and reduced angiogenesis. Conclusion: These data provide a new understanding of cisplatin resistance in cancer cells and may have implications for therapeutic reversal of drug resistance.
AB - Purpose: Resistance to platinum chemotherapy remains a significant problem in ovarian carcinoma. Here, we examined the biological mechanisms and therapeutic potential of targeting a critical platinum resistance gene, ATP7B, using both in vitro and in vivo models. Experimental Design: Expression of ATP7A and ATP7B was examined in ovarian cancer cell lines by real-time reverse transcription-PCR and Western blot analysis. ATP7A and ATP7B gene silencing was achieved with targeted small interfering RNA (siRNA) and its effects on cell viability and DNA adduct formation were examined. For in vivo therapy experiments, siRNA was incorporated into the neutral nanoliposome 1,2-dioleoyl-sn-glycero-3-phosphatidylcholine (DOPC). Results: ATP7A and ATP7B genes were expressed at higher levels in platinum-resistant cells compared with sensitive cells; however, only differences in ATP7B reached statistical significance. ATP7A gene silencing had no significant effect on the sensitivity of resistant cells to cisplatin, but ATP7B silencing resulted in 2.5-fold reduction of cisplatin IC50 levels and increased DNA adduct formation in cisplatin-resistant cells (A2780-CP20 and RMG2). Cisplatin was found to bind to the NH2-terminal copper-binding domain of ATP7B, which might be a contributing factor to cisplatin resistance. For in vivo therapy experiments, ATP7B siRNA was incorporated into DOPC and was highly effective in reducing tumor growth in combination with cisplatin (70-88% reduction in both models compared with controls). This reduction in tumor growth was accompanied by reduced proliferation, increased tumor cell apoptosis, and reduced angiogenesis. Conclusion: These data provide a new understanding of cisplatin resistance in cancer cells and may have implications for therapeutic reversal of drug resistance.
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U2 - 10.1158/1078-0432.CCR-08-2306
DO - 10.1158/1078-0432.CCR-08-2306
M3 - Article
C2 - 19470734
AN - SCOPUS:66649118310
SN - 1078-0432
VL - 15
SP - 3770
EP - 3780
JO - Clinical Cancer Research
JF - Clinical Cancer Research
IS - 11
ER -