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P73 regulates cisplatin-induced apoptosis in ovarian cancer cells via a calcium/calpain-dependent mechanism

P73 regulates cisplatin-induced apoptosis in ovarian cancer cells via a calcium/calpain-dependent mechanism
P73 regulates cisplatin-induced apoptosis in ovarian cancer cells via a calcium/calpain-dependent mechanism
P73 is important in drug-induced apoptosis in some cancer cells, yet its role in the regulation of chemosensitivity in ovarian cancer (OVCA) is poorly understood. Furthermore, if and how the deregulation of p73-mediated apoptosis confers resistance to cisplatin (CDDP) treatment is unclear. Here we demonstrate that TAp73? over-expression enhanced CDDP-induced PARP cleavage and apoptosis in both chemosensitive (OV2008 and A2780s) and their resistant counterparts (C13* and A2780cp) and another chemoresistant OVCA cells (Hey); in contrast, the effect of ?Np73? over-expression was variable. P73? downregulation attenuated CDDP-induced PUMA and NOXA upregulation and apoptosis in OV2008 cells. CDDP decreased p73? steady-state protein levels in OV2008, but not in C13*, although the mRNA expression was identical. CDDP-induced p73? downregulation was mediated by a calpain-dependent pathway. CDDP induced calpain activation and enhanced its cytoplasmic interaction and co-localization with p73? in OV2008, but not C13* cells. CDDP increased the intracellular calcium concentration ([Ca2+]i) in OV2008 but not C13* whereas cyclopiazonic acid (CPA), a Ca2+-ATPase inhibitor, caused this response and calpain activation, p73? processing and apoptosis in both cell types. CDDP-induced [Ca2+]i increase in OV2008 cells was not effected by the elimination of extracellular Ca2+, but this was attenuated by the depletion of internal Ca2+ store, indicating that mobilization of intracellular Ca2+] stores was potentially involved. These findings demonstrate that p73? and its regulation by the Ca2+-mediated calpain pathway are involved in CDDP-induced apoptosis in OVCA cells and that dysregulation of Ca2+/calpain/p73 signaling may in part be the pathophysiology of CDDP resistance. Understanding the cellular and molecular mechanisms of chemoresistance will direct the development of effective strategies for the treatment of chemoresistant OVCA.

0950-9232
4219-4230
Al-Bahlani, S.
c7a31c27-3933-45dd-96b1-4933b570504b
Fraser, M.
525afe70-c2ed-49e4-b46d-3fe44dd2de68
Wong, A. Y. C.
97edbce0-6897-472d-ac45-dc964333a9d6
Sayan, B.S.
ab62c915-3d79-45cb-a900-22ed58a07dfb
Bergeron, R.
38cb0bf2-c39c-451d-b307-82d2e326277f
Melino, G.
8704cb29-7407-416a-be51-a7efd06144c9
Tsang, B.K.
0f451e9d-0937-415b-9838-d79bbdef2e88
Al-Bahlani, S.
c7a31c27-3933-45dd-96b1-4933b570504b
Fraser, M.
525afe70-c2ed-49e4-b46d-3fe44dd2de68
Wong, A. Y. C.
97edbce0-6897-472d-ac45-dc964333a9d6
Sayan, B.S.
ab62c915-3d79-45cb-a900-22ed58a07dfb
Bergeron, R.
38cb0bf2-c39c-451d-b307-82d2e326277f
Melino, G.
8704cb29-7407-416a-be51-a7efd06144c9
Tsang, B.K.
0f451e9d-0937-415b-9838-d79bbdef2e88

Al-Bahlani, S., Fraser, M., Wong, A. Y. C., Sayan, B.S., Bergeron, R., Melino, G. and Tsang, B.K. (2011) P73 regulates cisplatin-induced apoptosis in ovarian cancer cells via a calcium/calpain-dependent mechanism. Oncogene, 30 (41), 4219-4230. (doi:10.1038/onc.2011.134).

Record type: Article

Abstract

P73 is important in drug-induced apoptosis in some cancer cells, yet its role in the regulation of chemosensitivity in ovarian cancer (OVCA) is poorly understood. Furthermore, if and how the deregulation of p73-mediated apoptosis confers resistance to cisplatin (CDDP) treatment is unclear. Here we demonstrate that TAp73? over-expression enhanced CDDP-induced PARP cleavage and apoptosis in both chemosensitive (OV2008 and A2780s) and their resistant counterparts (C13* and A2780cp) and another chemoresistant OVCA cells (Hey); in contrast, the effect of ?Np73? over-expression was variable. P73? downregulation attenuated CDDP-induced PUMA and NOXA upregulation and apoptosis in OV2008 cells. CDDP decreased p73? steady-state protein levels in OV2008, but not in C13*, although the mRNA expression was identical. CDDP-induced p73? downregulation was mediated by a calpain-dependent pathway. CDDP induced calpain activation and enhanced its cytoplasmic interaction and co-localization with p73? in OV2008, but not C13* cells. CDDP increased the intracellular calcium concentration ([Ca2+]i) in OV2008 but not C13* whereas cyclopiazonic acid (CPA), a Ca2+-ATPase inhibitor, caused this response and calpain activation, p73? processing and apoptosis in both cell types. CDDP-induced [Ca2+]i increase in OV2008 cells was not effected by the elimination of extracellular Ca2+, but this was attenuated by the depletion of internal Ca2+ store, indicating that mobilization of intracellular Ca2+] stores was potentially involved. These findings demonstrate that p73? and its regulation by the Ca2+-mediated calpain pathway are involved in CDDP-induced apoptosis in OVCA cells and that dysregulation of Ca2+/calpain/p73 signaling may in part be the pathophysiology of CDDP resistance. Understanding the cellular and molecular mechanisms of chemoresistance will direct the development of effective strategies for the treatment of chemoresistant OVCA.

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Published date: 2011
Organisations: Cancer Sciences

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Local EPrints ID: 341627
URI: http://eprints.soton.ac.uk/id/eprint/341627
ISSN: 0950-9232
PURE UUID: 9c89b6fd-667d-47f7-8a64-4612521c0f03

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Date deposited: 31 Jul 2012 16:24
Last modified: 14 Mar 2024 11:42

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Contributors

Author: S. Al-Bahlani
Author: M. Fraser
Author: A. Y. C. Wong
Author: B.S. Sayan
Author: R. Bergeron
Author: G. Melino
Author: B.K. Tsang

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