The neutrophil-to-lymphocyte ratio (NLR), a simple marker of the systemic inflammatory response in critical care patients, has been suggested as an independent prognostic factor for several solid malignancies. We investigated the utility of pretreatment NLR as a prognosticator in patients who presented with metastatic prostate cancer. We first investigated the correlation between NLR and prostate-specific antigen (PSA) levels in 1464 men who had both tests and were found to have prostate cancer on their biopsies at our institution from 1999 to 2015. We then assessed the relationship between pretreatment NLR and the prognosis in 48 patients who were diagnosed with prostate cancer metastasized to the lymph node and/or bone. The NLR value was significantly elevated in men with higher PSA than in those with lower PSA (p < 0.001). In patients with metastatic prostate cancer, NLR (cut-off point of 3.37 determined by the AUROC curve) was correlated with both cancer-specific (p = 0.018) and overall (p = 0.008) survivals. Pretreatment NLR may function as a new biomarker that precisely predicts the prognosis in patients with metastatic prostate cancer.

Non-muscular invasive bladder cancer (NMIBC) has a high risk of recurrence. As androgen receptor (AR) reportedly affects bladder cancer, we assessed the correlation between NMIBC recurrence and tumor AR expression in Japanese patients. We retrospectively reviewed 53 specimens of non-metastatic NMIBC, with recurrence-free survival (RFS) as the primary endpoint. We used real-time quantitative polymerase chain reaction to quantify AR mRNA expression. Kaplan–Meier product-limit estimators were used to assess RFS distribution, log-rank tests to analyze differences in RFS between high- and low-risk groups; and multivariate analyses of AR mRNA expression and other clinicopathological factors to predict independent factors for RFS. The high AR mRNA-expressing group (n = 43) tended to have a longer median RFS (not reached) than did the low-AR group (n = 10; 9.04 months; P = 0.112). Multivariate analysis showed female sex (hazard ratio [HR]: 7.360, 95% CI: 1.649–32.856, P = 0.009), tumor size ≥3 cm (HR: 23.697, 95% CI: 4.383–128.117, P < 0.001) and low AR mRNA expression (HR: 0.202, 95% CI: 0.048–0.841, P = 0.028) to be independent predictors of shorter RFS. Our study showed that low AR mRNA expression level is an independent risk factor for RFS in Japanese patients with NMIBC. Further studies are necessary but AR expression might be a new indicator of recurrence of NMIBC.

Some observational studies have implied a link between vasectomy and an elevated risk of prostate cancer. We investigated the impact of vasectomy on prostate cancer outgrowth, mainly using preclinical models. Neoplastic changes in the prostate were compared in transgenic TRAMP mice that underwent vasectomy vs. sham surgery performed at 4 weeks of age. One of the molecules identified by DNA microarray (i.e., ZKSCAN3) was then assessed in radical prostatectomy specimens and human prostate cancer lines. At 24 weeks, gross tumor (p = 0.089) and poorly differentiated adenocarcinoma (p = 0.036) occurred more often in vasectomized mice. Vasectomy significantly induced ZKSCAN3 expression in prostate tissues from C57BL/6 mice and prostate cancers from TRAMP mice. Immunohistochemistry showed increased ZKSCAN3 expression in adenocarcinoma vs. prostatic intraepithelial neoplasia (PIN), PIN vs. non-neoplastic prostate, Grade Group ≥3 vs. ≤2 tumors, pT3 vs. pT2 tumors, pN1 vs. pN0 tumors, and prostate cancer from patients with a history of vasectomy. Additionally, strong (2+/3+) ZKSCAN3 expression (p = 0.002), as an independent prognosticator, or vasectomy (p = 0.072) was associated with the risk of tumor recurrence. In prostate cancer lines, ZKSCAN3 silencing resulted in significant decreases in cell proliferation/migration/invasion. These findings suggest that there might be an association between vasectomy and the development and progression of prostate cancer, with up-regulation of ZKSCAN3 expression as a potential underlying mechanism.

Prostate cancer is one of the most common neoplasms in the USA and Europe. We used differential display PCR (DD-PCR) to identify androgen-regulated genes in prostate cancer. The RNA of LNCaP cells treated with dihydrotestosterone (DHT) was analyzed for differentially expressed genes. Using DD-PCR, we identified a down-regulated cDNA fragment by DHT in LNCaP cells. This fragment was cloned and expressions of this fragment in prostate cancer cell lines were analyzed by RT-PCR. Sequence analysis revealed that a cDNA fragment is identical to protein tyrosine phosphatase LAR related gene, liprin-α2. liprin-α2 was downregulated by dihydrotestosterone (DHT) in LNCaP cells in a time- and androgen concentration-dependent manner. Downregulation by DHT was not inhibited by the protein synthesis inhibitor cycloheximide. This liprin-α2 gene was not expressed in androgen independent prostate cancer cell lines PC-3 and DU-145 at the mRNA level. And also, we first revealed here that liprin-α2 mRNA is expressed in LNCaP cells as well as human prostate cancer tissues and normal prostate tissues. These data suggest that liprin-α2 might play a role in androgen responsive human prostate cancer cell line as well as human prostate cells, and the loss of this gene expression might be associated with the androgen independent characteristics of prostate cancer.