Jonathan Shamash

Background/Objectives: Although 90% of prostate cancer (PCa) metastasis occurs in the bone, there are limited studies and rarely available genome-wide profiles at individual sample level for genomic copy number changes in the literature. Methods: We performed Affymetrix SNP 6.0 high-density microarray analysis to generate the genome-wide copy number change profiles for six cases of PCa bone metastases. A common genomic loss was confirmed by fluorescence in situ hybridization (FISH) in paraffin-embedded PCa bone metastasis samples together with primary PCa and benign prostate hyperplasia samples. We overexpressed the candidate miRNA in PCa cell lines and knocked down its target genes by siRNA transfection and investigated the effect on protein expression and cell viability, migration, and invasion abilities, respectively. Protein expression in PCa tissues was analyzed by immunohistochemical staining. Results: We provided high-resolution PCa bone metastasis profiles of six cases and identified potential bone metastasis-specific common genomic alterations, including a 1.6 mb region on 17q11.2, as well as those shared by non-bone metastatic PCa. The common 17q11.2 loss was confirmed by FISH in further 14/21 PCa bone metastasis samples but was only found in 9/151 primary PCa samples. The well-established tumor-suppressing miRNA located within this small genomic region, miR-193a-3p, was downregulated in both bone metastasis and primary PCa cases, leading to overexpression of cyclin D1 and uPA to promote cancer cell migration and invasion. Cyclin D1 was highly expressed in both localized PCa and bone metastasis samples, and the expression was significantly higher in the latter group (p = 0.013). Conclusions: We generated high-resolution copy number change profiles for bone metastasis samples. This led to the identification of a common, small genomic loss and downregulation of miR-193a-3p, which suppresses PCa bone metastasis through inhibition of its target proteins, providing new insight into bone metastasis development.

Background Prostate cancer in black men is associated with poorer outcomes than their white counterparts. However, most studies reporting this disparity were conducted in localized prostate cancer and primarily in the United States. Methods Data regarding prostate cancer incidence and mortality for East London between 2008 and 2010 were obtained from the UK National Disease Registration Service. We further evaluated survival outcomes of 425 cases of mCRPC in St Bartholomew’s Hospital, East London, between 1997 and 2016, and analyzed whether ethnicity impacted on responses to different treatment types. Results The incidence of prostate cancer in black men was higher than white men in East London. Prostate cancer-specific mortality was proportional to incidence based on ethnic groups. In the detailed analysis of 425 patients, 103 patients (24%) were black (B), and the remainder white (W). Baseline characteristics were comparable in both groups, although black patients had a lower baseline hemoglobin (p < 0.001). Median overall survival for the total cohort was 25.5 months (B) vs 21.8 months (W) (hazard ratio (HR) = 0.81, p = 0.08). There was prolonged survival in the black population in those who only received hormone-based treatment throughout their treatment course; 39.7 months (B) vs 17.1 months (W) (HR = 0.54, p = 0.019). Conclusion Black men may do better than white men with mCRPC, in the context of equal access to healthcare. The study also suggests a greater margin of benefit of hormone-based therapy in the black subpopulation.