Comparative Proteome Analysis Of Ovarian Cancer, Paclitaxel Resistance-associated Protein And Resistance Expression Of Candidate Proteins Cofilin1 Study

Background and objectiveOvarian cancer ranks as the third leading cause of death from cancers and has the highest mortality rate among the gynecologic malignancies. Combination chemotherapy including paclitaxel(taxol) has resulted in response rate of 60-80% in patients with advanced stages, but because of the development of drug resistance, complete remission and five-year survival rate were sustained only 15-20%. A search for the mechanisms by chemoresistance is being made worldwide. To date, several understood mechanisms of resistance to paclitaxel in vitro were the MDR phenotype mediated by the multidrug transporter P-gp and alteration in α- and β-tubulin subunits. However, all of them could not predict the prognosis of cancers very well. Another possible mechanism might be searched by novel advanced techniques.Proteomics approach provides a new tool for the identification of disease-associated markers. It may capture the molecular characterization of the cellular events associated with cancer transformation and progression, as well as the development of new molecular methods for the early diagnosis and prognostic evaluation of chemoresistance.To better investigate the mechanisms inducing taxol resistance, we have performed a proteomics analysis of different taxol-resistant ovarian cancer cell lines. A total of 16 proteins, which possibly related to ovarian cancer cell resistance to taxol, were determined by two-dimensional protein mapping as well as mass spectroscopic analysis. To further confirm the role of cofilinl in drug resistance, one of common overexpressed proteins in all resistant cell lines, cofilinl cDNA was transfected into chemosensitive cells. Cofilinl transfectants were more resistant to taxol as compared to the vector controls. Moreover, expression of different forms of cofilinl was detected in human ovarian cancer specimens by immunohistochemisty. Thus our sutdy indicates that cofilinl plays a role in regulating taxol resistance. Materials and methods1. Two SKOV3 taxol-resistant cell strains, SK-TR30 and SK-TR2500, were induced by intermittent stepwised increasing with low concentration and impulsed with high concentration of taxol, respectively. Various possible drug resistant genes were detected in all sensitive and resistant ovarian cancer cells, together with A2780 and its taxol-resistant subtype, A2780-TR.2. Protein profilings of taxol-sensitive (SKOV3, A2780) and -resistant (SK-TR30, SK-TR2500, A2780-TR)cells were established by two-dimensional gel electrophoresis and identification of candidate protein related taxol-resistance by...