Class III β-tubulin expression in advanced-stage serous ovarian carcinoma effusions is associated with poor survival and primary chemoresistance.
ABSTRACT The objective of this study was to analyze the clinical role of nestin, a stem cell marker, and class III β-tubulin in advanced-stage serous ovarian carcinoma. Nestin and class III β-tubulin protein expression were investigated in 217 effusions using immunohistochemistry. Results were analyzed for association with clinicopathologic parameters including chemotherapy response and survival. Class III β-tubulin and nestin were expressed in tumor cells in 98.6% and 95.6% of specimens, respectively. Staining extent was comparable in prechemotherapy and postchemotherapy effusions. No association was found with patient age, histologic grade, International Federation of Gynecology and Obstetrics stage, primary surgery versus secondary debulking, or residual disease volume. High class III β-tubulin expression in prechemotherapy effusions was significantly associated with primary chemoresistance (progression-free survival <6 months; P = .036) and with a trend for less favorable response to first-line treatment (P = .054). In univariate survival analysis, high class III β-tubulin expression in prechemotherapy effusions was significantly associated with poor overall survival (P = .021), with a trend for poor progression-free survival (P = .067). These associations did not have independent prognostic value in Cox multivariate analysis. Nestin expression was unrelated to chemoresistance or survival. Both class III β-tubulin and nestin are frequently expressed in serous ovarian carcinoma cells in effusions. Nestin does not provide predictive or prognostic data in this patient group, whereas class III β-tubulin expression in prechemotherapy effusions is associated with poor chemoresponse and shorter survival, suggesting that it may be a therapeutic target in ovarian cancer.
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ABSTRACT: The objective of this study was to investigate the expression and clinical role of the spindle checkpoint kinase budding uninhibited by benzimidazole 1 (Bub1) in primary and metastatic advanced-stage ovarian serous carcinoma. BUB1 mRNA expression was analyzed in 178 tumors (88 effusions, 38 primary carcinomas, and 52 solid metastases) from 144 patients with advanced-stage disease using quantitative real-time polymerase chain reaction (PCR). Bub1 protein expression by Western blotting was studied in 63 carcinomas (30 effusions and 33 solid lesions). BUB1 mRNA expression at different anatomic sites was studied for association with clinicopathologic parameters, including chemotherapy resistance and survival. BUB1 mRNA was universally expressed in serous carcinomas, irrespective of anatomic site. BUB1 mRNA levels were uniformly low in six ovarian surface epithelium specimens analyzed for comparative purposes. Bub1 protein was expressed in 22/30 effusions and 28/33 solid lesions. BUB1 mRNA expression was significantly higher in chemo-naïve primary carcinomas and solid metastases compared to specimens obtained following neoadjuvant chemotherapy (p < 0.001) and was unrelated to chemotherapy exposure in effusions nor to chemoresponse or survival at any anatomic site. BUB1 mRNA levels in both effusions and solid lesions were strongly related to the mRNA levels of AURKA and AURKB previously studied in this cohort (p < 0.001 for both). Bub1 is widely expressed in primary and metastatic OC, suggesting a biological role in this cancer. BUB1 mRNA levels are lower following chemotherapy exposure in solid lesions, though its presence is unrelated to clinical behavior including response to chemotherapy and survival. BUB1 is co-expressed with AURKA and AURKB suggesting biological relationship between these spindle cell components.Archiv für Pathologische Anatomie und Physiologie und für Klinische Medicin 04/2014; DOI:10.1007/s00428-014-1577-7 · 2.56 Impact Factor
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ABSTRACT: We studied mechanisms of resistance to the novel taxane cabazitaxel in established cellular models of taxane resistance. We also developed cabazitaxel-resistant variants from MCF-7 breast cancer cells by stepwise selection in drug alone (MCF-7/CTAX) or drug plus the transport inhibitor PSC-833 (MCF-7/CTAX-P). Among multidrug resistant (MDR) variants, cabazitaxel was relatively less cross-resistant than paclitaxel and docetaxel (15 vs. 200-fold in MES-SA/Dx5 and 9 vs. 60-fold in MCF-7/TxT50, respectively). MCF-7/TxTP50 cells that were negative for MDR but had 9-fold resistance to paclitaxel were also 9-fold resistant to cabazitaxel. Selection with cabazitaxel alone (MCF-7/CTAX) yielded 33-fold resistance to cabazitaxel, 52-fold resistance to paclitaxel, activation of ABCB1, and 3-fold residual resistance to cabazitaxel with MDR inhibition. The MCF-7/CTAX-P variant did not express ABCB1, nor did it efflux rhodamine-123, BODIPY-labeled paclitaxel, and [3H]-docetaxel. These cells are hypersensitive to depolymerizing agents (vinca alkaloids and colchicine), have reduced baseline levels of stabilized microtubules, and impaired tubulin polymerization in response to taxanes (cabazitaxel or docetaxel) relative to MCF-7 parental cells. Class III beta-tubulin (TUBB3) RNA and protein were elevated in both MCF-7/CTAX and MCF-7/CTAX-P. Decreased BRCA1 and altered epithelial-mesenchymal transition (EMT) markers are also associated with cabazitaxel resistance in these MCF-7 variants, and may serve as predictive biomarkers for its activity in the clinical setting. In summary, cabazitaxel resistance mechanisms include MDR (although at a lower level than paclitaxel and docetaxel), and alterations in microtubule dynamicity, as manifested by higher expression of TUBB3, decreased BRCA1, and by the induction of EMT. Copyright © 2014, American Association for Cancer Research.Molecular Cancer Therapeutics 11/2014; 14(1). DOI:10.1158/1535-7163.MCT-14-0155 · 6.11 Impact Factor
Expert Review of Obstetrics & Gynecology 01/2014; 6(4). DOI:10.1586/eog.11.33