Alpingo-oophorectomy, omentectomy and resection of all visible and palpable bulky tumor and lymphadenectomy, 16960-16-0 according to the National Comprehensive Cancer Network (NCCN) guidelines. Information 
on treatment and response was obtained by patient chart review. After debulking, the patients received six cycles of platinumbased combination chemotherapy. The chemotherapy drugs included paclitaxel (135?75 mg/m2), carboplatin (area under curve [AUC] 5?), doxepaclitaxel (70 mg/m2) and cisplatin (65?75 mg/m2). Based on the NCCN guidelines, intrinsically chemoresistant tumors were defined as those with persistent or recurrent disease within 6 months after the initiation 12926553 of first-line platinumbased combination chemotherapy. Chemosensitive tumors were classified as those with a complete response to chemotherapy and a platinum-free interval of .6 months. Ascites were centrifuged at 2,000 rpm for 15 min at 4uC to separate the fluid from cellular components. The suspension was briefly sonicated, and the debris was centrifuged at 14,000 rpm for 10 min at 4uC. The supernatant was resuspended and washedGel Image Acquisition and AnalysisGel images were acquired on a Typhoon 9400 scanner (Amersham Biosciences) and analyzed using DeCyder Software (V6.0, GE Healthcare) as described previously [7]. The Cy2, Cy3 and Cy5 signals were individually imaged with excitation/emission wavelengths of 488/520, 532/580 and 633/670 nm, respectively. Preparative gels (Deep Purple Total Protein Stain) were scanned with excitation/emission wavelengths of 532/560 nm according to the user’s manual. Proteins in chemosensitive ascites samples were compared with those in chemoresistant ones. Increases or decreases of protein abundance of more than 1.5-fold (t-test andBiomarkers for Chemoresistant Ovarian CancerANOVA, P,0.01) were considered significant changes. The corresponding protein spots were selected in the stained preparative gel for spot picking.Results Clinical Patient InformationNineteen ascites samples of serous EOC patients were analyzed using 2D-DIGE to screen potential biomarkers associated with differential responses to chemotherapy. Samples from a separate cohort of 28 patients with serous EOC were used for validation of the 2D-DIGE results by ELISA. All patients had received satisfactory cytoreductive surgery. There were no significant differences in age at diagnosis, tumor differentiation and International Federation of Gynecology and Obstetrics 1516647 (FIGO) staging between the patients in the chemosensitive and chemoresistant groups. Madrasin biological activity Demographic and clinical features of the cases are shown in Table 1. In addition, survival rates of the 28 patients tested by ELISA were compared according to their different responses to chemotherapy. By March 2012, four of the nine patients (44.4 ) in the chemoresistant group and three of nineteen patients (15.8 ) had died in the chemosensitivity group. The median survival time of the nine chemoresistant ovarian cancer patients in our study was 18.9 months. However, a longer period of follow-up was needed to determine an accurate median survival of chemosensitive patients, which was more than 18.9 months. Based on the observation period in this study, the difference in survival between the two groups as observed using Kaplan eier estimates was significant (P = 0.007), favoring those with better responses to chemotherapy (Fig. 1).Protein Spot HandlingThe selected protein spots in the preparative gels were automatically picked and handle.Alpingo-oophorectomy, omentectomy and resection of all visible and palpable bulky tumor and lymphadenectomy, according to the National Comprehensive Cancer Network (NCCN) guidelines. Information on treatment and response was obtained by patient chart review. After debulking, the patients received six cycles of platinumbased combination chemotherapy. The chemotherapy drugs included paclitaxel (135?75 mg/m2), carboplatin (area under curve [AUC] 5?), doxepaclitaxel (70 mg/m2) and cisplatin (65?75 mg/m2). Based on the NCCN guidelines, intrinsically chemoresistant tumors were defined as those with persistent or recurrent disease within 6 months after the initiation 12926553 of first-line platinumbased combination chemotherapy. Chemosensitive tumors were classified as those with a complete response to chemotherapy and a platinum-free interval of .6 months. Ascites were centrifuged at 2,000 rpm for 15 min at 4uC to separate the fluid from cellular components. The suspension was briefly sonicated, and the debris was centrifuged at 14,000 rpm for 10 min at 4uC. The supernatant was resuspended and washedGel Image Acquisition and AnalysisGel images were acquired on a Typhoon 9400 scanner (Amersham Biosciences) and analyzed using DeCyder Software (V6.0, GE Healthcare) as described previously [7]. The Cy2, Cy3 and Cy5 signals were individually imaged with excitation/emission wavelengths of 488/520, 532/580 and 633/670 nm, respectively. Preparative gels (Deep Purple Total Protein Stain) were scanned with excitation/emission wavelengths of 532/560 nm according to the user’s manual. Proteins in chemosensitive ascites samples were compared with those in chemoresistant ones. Increases or decreases of protein abundance of more than 1.5-fold (t-test 
andBiomarkers for Chemoresistant Ovarian CancerANOVA, P,0.01) were considered significant changes. The corresponding protein spots were selected in the stained preparative gel for spot picking.Results Clinical Patient InformationNineteen ascites samples of serous EOC patients were analyzed using 2D-DIGE to screen potential biomarkers associated with differential responses to chemotherapy. Samples from a separate cohort of 28 patients with serous EOC were used for validation of the 2D-DIGE results by ELISA. All patients had received satisfactory cytoreductive surgery. There were no significant differences in age at diagnosis, tumor differentiation and International Federation of Gynecology and Obstetrics 1516647 (FIGO) staging between the patients in the chemosensitive and chemoresistant groups. Demographic and clinical features of the cases are shown in Table 1. In addition, survival rates of the 28 patients tested by ELISA were compared according to their different responses to chemotherapy. By March 2012, four of the nine patients (44.4 ) in the chemoresistant group and three of nineteen patients (15.8 ) had died in the chemosensitivity group. The median survival time of the nine chemoresistant ovarian cancer patients in our study was 18.9 months. However, a longer period of follow-up was needed to determine an accurate median survival of chemosensitive patients, which was more than 18.9 months. Based on the observation period in this study, the difference in survival between the two groups as observed using Kaplan eier estimates was significant (P = 0.007), favoring those with better responses to chemotherapy (Fig. 1).Protein Spot HandlingThe selected protein spots in the preparative gels were automatically picked and handle.
