TY - JOUR
T1 - BCL2 antagonist of cell death kinases, phosphatases, and ovarian cancer sensitivity to cisplatin
AU - Bansal, Nisha
AU - Marchion, Douglas C.
AU - Bicaku, Elona
AU - Xiong, Yin
AU - Chen, Ning
AU - Stickles, Xiaomang B.
AU - Sawah, Entidhar Al
AU - Wenham, Robert M.
AU - Apte, Sachin M.
AU - Gonzalez-Bosquet, Jesus
AU - Judson, Patricia L.
AU - Hakam, Ardeshir
AU - Lancaster, Johnathan M.
PY - 2012
Y1 - 2012
N2 - Objective: The BCL2 family proteins are critical mediators of cellular apoptosis and, as such, have been implicated as determinants of cancer cell chemo-sensitivity. Recently, it has been demonstrated that the phosphorylation status of the BCL2 antagonist of cell death (BAD) protein may influence ovarian cancer (OVCA) cell sensitivity to cisplatin. Here, we sought to evaluate how kinase and phosphatase components of the BAD apoptosis pathway influence OVCA chemo-sensitivity. Methods: Protein levels of cyclin-ependent kinase 1 (CDK1) and protein phosphatase 2C (PP2C) were measured by immuno fluorescence in a series of 64 primary advanced-stage serous OVCA patient samples. In parallel, levels of cAMP-dependent protein kinase (PKA), AKT, and PP2C were quantified by Western blot analysis in paired mother/daughter platinum-sensitive/resistant OVCA cell lines (A2008/C13, A2780S/A2780CP, Chi/ChiR). BAD pathway kinase CDK1 was depleted using siRNA transfection, and the influence on BAD phosphorylation and cisplatin-induced apoptosis was evaluated. Results: OVCA patient samples that demonstrated complete responses to primary platinum-based therapy demonstrated 4-fold higher CDK1 (p<0.0001) and 2-fold lower PP2C (p=0.14) protein levels than samples that demonstrated incomplete responses. Protein levels of PP2C were lower in the platinum-resistant versus that shown in the platinum-sensitive OVCA cell line sub-clones. Levels of PKA were higher in all platinum-resistant than in platinum-sensitive OVCA cell line sub-clones. Selective siRNA depletion of CDK1 increased sensitivity to cisplatin-induced apoptosis (p<0.002). Conclusion: BAD pathway kinases and phosphatases, including CDK1 and PP2C, are associated with OVCA sensitivity to platinum and may represent therapeutic opportunities to enhance cytotoxic efficacy.
AB - Objective: The BCL2 family proteins are critical mediators of cellular apoptosis and, as such, have been implicated as determinants of cancer cell chemo-sensitivity. Recently, it has been demonstrated that the phosphorylation status of the BCL2 antagonist of cell death (BAD) protein may influence ovarian cancer (OVCA) cell sensitivity to cisplatin. Here, we sought to evaluate how kinase and phosphatase components of the BAD apoptosis pathway influence OVCA chemo-sensitivity. Methods: Protein levels of cyclin-ependent kinase 1 (CDK1) and protein phosphatase 2C (PP2C) were measured by immuno fluorescence in a series of 64 primary advanced-stage serous OVCA patient samples. In parallel, levels of cAMP-dependent protein kinase (PKA), AKT, and PP2C were quantified by Western blot analysis in paired mother/daughter platinum-sensitive/resistant OVCA cell lines (A2008/C13, A2780S/A2780CP, Chi/ChiR). BAD pathway kinase CDK1 was depleted using siRNA transfection, and the influence on BAD phosphorylation and cisplatin-induced apoptosis was evaluated. Results: OVCA patient samples that demonstrated complete responses to primary platinum-based therapy demonstrated 4-fold higher CDK1 (p<0.0001) and 2-fold lower PP2C (p=0.14) protein levels than samples that demonstrated incomplete responses. Protein levels of PP2C were lower in the platinum-resistant versus that shown in the platinum-sensitive OVCA cell line sub-clones. Levels of PKA were higher in all platinum-resistant than in platinum-sensitive OVCA cell line sub-clones. Selective siRNA depletion of CDK1 increased sensitivity to cisplatin-induced apoptosis (p<0.002). Conclusion: BAD pathway kinases and phosphatases, including CDK1 and PP2C, are associated with OVCA sensitivity to platinum and may represent therapeutic opportunities to enhance cytotoxic efficacy.
KW - Bad apoptosis pathway
KW - Cisplatin
KW - Cyclin-dependent kinase 1
KW - Ovarian cancer
KW - Protein phosphatase 2c
KW - Survival
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U2 - 10.3802/jgo.2012.23.1.35
DO - 10.3802/jgo.2012.23.1.35
M3 - Article
C2 - 22355465
AN - SCOPUS:84857611632
SN - 2005-0380
VL - 23
SP - 35
EP - 42
JO - Journal of Gynecologic Oncology
JF - Journal of Gynecologic Oncology
IS - 1
ER -