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Catechol-estrogens can cause genetic mutations and to counteract their oncogenicity, the catechol-O-methyltransferase (COMT) gene is capable of neutralizing these reactive compounds. In this study, we determined the functional effects and regulation of COMT in prostate cancer. Both the Cancer Genome Atlas (TCGA) and immunohistochemical analysis of clinical specimens demonstrated a reduction of COMT expression in prostate cancer. Also, western analyses of prostate cancer cell lines show COMT levels to be minimal in DuPro and DU145 and thus, these cells were used for further analyses. Re-expression of COMT led to suppressed migration ability (wound healing assay) and enhanced apoptosis (flow cytometric analyses), and when challenged with 4-hydroxyestradiol, a marked reduction of cell proliferation (MTT assay) was observed. Xenograft growth in athymic mice also resulted in inhibition due to COMT. As a mechanism, western analyses show cleaved CASP3 and BID were increased whereas XIAP and cIAP2 were reduced due to COMT. As COMT expression is low in prostate cancer, its regulation was determined. Databases identified several miRNAs capable of binding COMT and of these, miR-195 was observed to be increased in prostate cancer according to TCGA. Real-time PCR validated upregulation of miR-195 in clinical prostate cancer specimens as well as DuPro and DU145 and interestingly, luciferase reporter showed miR-195 capable of binding COMT and overexpressing miR-195 could reduce COMT in cells. These results demonstrate COMT to play a protective role by activating the apoptosis pathway and for miR-195 to regulate its expression. COMT may thus be a potential biomarker and gene of interest for therapeutic development for prostate cancer. [ABSTRACT FROM AUTHOR]

Highlights: [•] Expression of CCR1 was higher in paclitaxel-resistant PC3 cells than in PC3 cells. [•] Knockdown of CCR1 decreased CCL5-stimulated activation of ERK and Rac signaling. [•] CCR1 knockdown and ERK inhibition reduced CCL5-stimulated MMP secretion. [•] Knockdown of CCR1 and inhibition of ERK and Rac signaling attenuated cell invasion. [•] CCR1 could be a novel therapeutic target for taxane-resistant CRPC. [ABSTRACT FROM AUTHOR]

Objectives: Cortactin is overexpressed in various types of cancer and enhances cell motility. It has been recently reported that silent mating type information regulation 2 homolog 1 interacts with cortactin and promotes cell migration. Here, we examined the role of cortactin and silent mating type information regulation 2 homolog 1 in migration and invasion of prostate cancer cells. Methods: The cortactin expression levels in DU145, LNCaP and PC3 prostate cancer cells, and in PrEC normal human prostate epithelial cells were evaluated by western blot analysis. In DU145 cells, the expression of cortactin or silent mating type information regulation 2 homolog 1 was inhibited by small interfering RNA, and the effects of their knockdown on migration and invasion were examined by cell migration and invasion assays. To determine the localization of cortactin and silent mating type information regulation 2 homolog 1, western blot and immunofluorescence microscopic analyses were carried out. The functional interaction between silent mating type information regulation 2 homolog 1 and cortactin was also studied by in vivo acetylation assay. Results: The protein expression of cortactin was significantly higher in DU145 cells than in other cell lines. Knockdown of cortactin or silent mating type information regulation 2 homolog 1 expression inhibited both migration and invasion of DU145 cells. Similarly to cortactin, silent mating type information regulation 2 homolog 1 was found to be predominantly expressed in the cytoplasm. Finally, the knockdown of silent mating type information regulation 2 homolog 1 expression increased the acetylation level of cortactin. Conclusions: Our findings suggest that inhibition of cortactin or silent mating type information regulation 2 homolog 1 expression attenuates migration and invasion of DU145 cells and this could represent a promising strategy to regulate metastasis of prostate cancer. [ABSTRACT FROM AUTHOR]