Righetti SC, Perego P, Carenini N, Corna E, Dal Bo L, Cedrola S, La Porta CAM, Zunino F. Molecular alterations of cells resistant to platinum drugs: role of PKCalpha.
Biochim Biophys Acta 2006;
1763:93-100. [PMID:
16473140 DOI:
10.1016/j.bbamcr.2005.12.007]
[Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/23/2005] [Revised: 11/25/2005] [Accepted: 12/12/2005] [Indexed: 11/19/2022]
Abstract
Development of resistance to platinum compounds may involve not only overexpression of defence mechanisms but also alterations in cellular response to the drug-induced genotoxic stress. To investigate the cellular bases of response to platinum compounds, we examined the profile of gene expression of ovarian carcinoma cells exhibiting sensitivity (A2780) or resistance (A2780/BBR3464) to platinum compounds. Using display PCR, we found that acquisition of resistance to the multinuclear platinum complex BBR3464 was associated with modulation of several transcripts, including up-regulation of the major substrate of protein kinase C (PKC), the myristoylated alanine-rich C kinase substrate (MARCKS). This feature was associated with PKCalpha down-regulation. To explore the role of PKCalpha in cellular sensitivity to platinum compounds, resistant cells were transfected with a PKCalpha-containing vector. PKCalpha-overexpressing resistant cells exhibited a decrease in sensitivity to cisplatin, whereas no significant change in sensitivity to BBR3464 was observed. A number of approaches designed to modulate the function or expression of PKCalpha support that the isoenzyme may play a role in determining resistance only to cisplatin but not to BBR3464, which is known to activate a different pathway of cell response. In conclusion, in spite of PKCalpha down-regulation in our model, its regulatory function was not apparently implicated in the development of resistance to platinum compounds and the present results do not support a general role of PKCalpha as a determinant of the resistance status.
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