Do The Expressions of Epithelial-Mesenchymal Transition Proteins, Periostin, Integrin-Alpha 4 and Fibronectin Correlate With Clinico-Pathological Features and Prognosis of Metastatic Castration-Resistant Prostate Cancer?

Abstract

Development of metastatic castration-resistant prostate cancer is a result of the lack of an apoptotic response by the tumor cells and loss of the ability to stick to adjacent cells through epithelial-mesenchymal transition. Although there are several strongly recommended biomarkers for determining prognosis of metastatic castration-resistant prostate cancer, only few of them may help decide the selection of the optimal treatment option. The mode of treatment sequencing in metastatic castration-resistant prostate cancer will be based on the individual characteristics of the patient. In this study, we aimed to explain the correlation between the expression characteristics of periostin, integrin-alpha 4, and fibronectin in metastatic castration-resistant prostate cancer patients and their clinico-pathological data comprising Gleason score, PSA levels, and metastatic sites in the process of epithelial-mesenchymal transition. We evaluated by using Western blotting, periostin, integrin-alpha 4, and fibronectin expressions in peripheral blood samples of metastatic castration-resistant prostate cancer patients (n=40), benign prostatic hyperplasia patients (n=20), and the healthy control group (n=20). Associations between changes in the protein expressions and clinico-pathological parameters were also analyzed in the metastatic castration-resistant prostate cancer group. When comparing BPH and healthy groups with the metastatic castration-resistant prostate cancer group, a reduced expression of integrin-alpha 4 was found in metastatic patients, albeit being statistically insignificant (P>0.05). Protein expressions of periostin and fibronectin in the metastatic castration-resistant prostate cancer group were higher than those in the BPH and heathy groups (P<0.001). Increased periostin expression in metastatic patients was significantly associated with bone metastasis (P<0.05). Elevated periostin and fibronectin levels in metastatic castration-resistant prostate cancer patients may be appropriate targets of therapeutic intervention in the future.