Overexpression of DNA Polymerase ζAffects Cisplatin Resistance in Ovarian Cancer: An Immunohistochemical Study

Autor: NAGASHIMA, Minoru, OKUDA, Tsuyoshi, NAGATSUKA, Masaaki, KUSHIMA, Miki, TONOIKE, Takahiko, OKAI, Takashi
Jazyk: angličtina
Rok vydání: 2013
Předmět:
Zdroj: The Showa University journal of medical sciences. 25(2):109-118
ISSN: 0915-6380
Popis: DNA polymerase ζ (Pol ζ) participates in translesional bypass replication. Pol ζ has been shown to be an important contributor to cis-diamminedichloroplatinum (II)(DDP; cisplatin) -induced genomic instability and the subsequent emergence of resistance in vitro. We immunohistochemically examined the expression of Pol ζ in ovarian cancer tissues to determine whether its expression affects the DDP resistance of human ovarian cancers and also to determine whether Pol ζ expression is a prognostic factor for ovarian cancers. We assessed 76 archival, formalin-fixed, paraffin-embedded tissue samples obtained from patients with epithelial ovarian cancers who underwent their first operation between 2003 and 2011. An ovarian cancer tissue array was also used in this study. Immunohistochemical staining of Pol ζ was performed using an anti-human Pol ζ monoclonal rabbit antibody. The strength of expression of Pol ζ was compared with the DDP resistance and clinical features of the study population. The Pol ζ over-expression in ovarian cancer tissue which compared with epithelial cells in normal ovaries was not affected by the histological types, FIGO stage, or patient age, but Pol ζ was significantly more overexpressed in the DDP-resistant group than in the DDP-sensitive group (P = 0.043). Pol ζ over-expression did not significantly affect the survival rate of the ovarian cancer patients; however, the Pol ζ positive group tended to have a poorer long-term prognosis. In conclusion, ovarian carcinoma patients with Pol ζ over-expression are likely to be resistant to DDP, especially in cases of recurrent disease. These results confirm the previous findings in vitro, wherein Pol ζ modulated the cytotoxicity and mutagenicity of DDP.
Databáze: OpenAIRE