Overexpression of GPNMB predicts an unfavorable outcome of epithelial ovarian cancer
Glycoprotein non-metastatic protein B (GPNMB) is a transmembrane glycoprotein that is expressed at higher levels in several malignant human tissues than those in matched normal tissues. Thus, GPNMB may serve as an attractive therapeutic target of cancer treatment. In this study, the prognostic value of GPNMB expression was examined in tumors derived from a cohort of patients with epithelial ovarian cancer (EOC).
GPNMB expression in matched formalin-fixed and paraffin-embedded tissue samples was evaluated by immunohistochemistry (IHC), whereas GPNMB mRNA expression in fresh-frozen biopsy tissues was detected using real-time quantitative PCR (qPCR). Meanwhile, the correlations of GPNMB expression with the clinical characteristics of EOC were assessed. Besides, survival data were analysed using Kaplan–Meier and Cox regression analyses, respectively.
GPNMB expression was remarkably upregulated in EOC tissues compared with that in normal ovarian controls at both mRNA and protein levels. In addition, abundant GPNMB expression in EOC was correlated with the International Federation of Gynecology and Obstetrics (FIGO) stage (P < 0.001), residual tumor (P = 0.036), and lymph node metastasis (P = 0.004). Furthermore, results of univariate and multivariate analyses indicated that GPNMB expression level was an independent prognostic factor of the progression-free survival (PFS) and overall survival (OS) (P < 0.001 and P < 0.001, respectively) for EOC patients.
Upregulated GPNMB levels in EOC patients are associated with dismal prognosis. Moreover, findings in the current study indicate that GPNMB is a potentially useful prognostic predictor of the therapeutic approaches for EOC.
KeywordsEpithelial ovarian cancer GPNMB Immunohistochemistry Prognosis
We thank Dr. Danhua Shen and Dr. Kunkun Sun from Department of Pathology of Peking University People’s Hospital for their helpful advice on pathological assessments. This work is supported by the National Key Research and Development Programme of China (Grant No. 2016YFA0201400) and the National Key Technology R&D Program (Grant No. 2015BAI13B06).
RM is responsible for project development, data analysis and manuscript compiling. ZT and XY are in charge of data collection or management. HC and KS take charge of data analysis. XC and HC are responsible for protocol/project development.
Compliance with ethical standards
Conflict of interest
The authors declare no conflict of interest.
Study involving human participants
Tissues from human participants are adopted in the current study. All procedures performed in studies involving human participants should be in strict accordance with the ethical standards of the Institute Research Ethics Committee of Peking University People’s Hospital as well as the Helsinki declaration (1964) and its later amendments or comparable ethical standards.
Informed consent is obtained from all participants enrolled in the current study.
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