Identification of Cisplatin-Resistance Associated Genes through Proteomic Analysis of Human Ovarian Cancer Cells and a Cisplatin-resistant Subline

Jing Zhou,Yue-Hua Wei,Jie-Lan Li,Hong-Bing Cai,Yan Xiong,Mei-Yan Liao

doi:10.7314/apjcp.2012.13.12.6435

Abstract

Chemoresistance to cancer therapy is a major obstacle to the effective treatment of human cancers with cisplatin (DDP), but the mechanisms of cisplatin-resistance are not clear. In this study, we established a cisplatin- resistant human ovarian cancer cell line (COC1/DDP) and identified differentially expressed proteins related to cisplatin resistance. The proteomic expression profiles in COC1 before and after DDP treatment were examined using 2-dimensional electrophoresis technology. Differentially expressed proteins were identified using matrix- assisted laser desorption/ ionization time-of-flight mass spectrometry (MALDI-TOF-MS) and high performance liquid chromatography-electrospray tandem MS (NanoUPLC-ESI-MS/MS). 5 protein spots, for cytokeratin 9, keratin 1, deoxyuridine triphosphatase (dUTPase), aarF domain containing kinase 4 (ADCK 4) and cofilin1, were identified to be significantly changed in COC1/DDP compared with its parental cells. The expression of these five proteins was further validated by quantitative PCR and Western blotting, confirming the results of proteomic analysis. Further research on these proteins may help to identify novel resistant biomarkers or reveal the mechanism of cisplatin-resistance in human ovarian cancers.

Highlights

Ovarian cancer is the fifth most common cause of cancer deaths in women and accounts for the highest tumor-related mortality of gynecologic malignancies (Jemal et al, 2009)
Expressed proteins were identified using matrixassisted laser desorption/ ionization time-of-flight mass spectrometry (MALDI-TOF-MS) and high performance liquid chromatography-electrospray tandem MS (NanoUPLC-ESI-MS/MS). 5 protein spots, for cytokeratin 9, keratin 1, deoxyuridine triphosphatase, aarF domain containing kinase 4 (ADCK 4) and cofilin1, were identified to be significantly changed in COC1/DDP compared with its parental cells
Cisplatin and its analogues are the key compounds of chemotherapy for human ovarian cancers, but chemoresistance is a major obstacle hindering the successful treatment of ovarian cancer patients (Ozols et al, 1985; Yuan et al, 2003)

Summary

Introduction

Ovarian cancer is the fifth most common cause of cancer deaths in women and accounts for the highest tumor-related mortality of gynecologic malignancies (Jemal et al, 2009). A number of genes, such as GST-pi, LRP, MDR1, XIAP, HER2/neu, hMLH 2, and hMSH1, BRCA 2, mdrl, BCL-2 and BCL-XL (Hamada et al.,1994; Veneroni et al, 1994; Aebi et al, 1996; Marth et al, 1997; Sasaki et al, 2000; Rudin et al, 2003; Williams et al, 2005 Yuan et al, 2011), have been linked to drug resistance in ovarian cancer, whereas general consensus for biomarkers has not been established to detect tumor resistance to special chemotherapy. Based on our previous study, we have further confirmed and identified 5 proteins to be down-regulated in resistant lines. They may be involved in the mechanisms of cisplatin resistance in ovarian cancer

Materials and Methods

Results

Findings

Discussion