Masahiro Yao

Functional epigenomics approach to identify methylated candidate tumour suppressor genes in renal cell carcinoma.

Promoter region hypermethylation and transcriptional silencing is a frequent cause of tumour suppressor gene (TSG) inactivation in many human cancers. Previously, to identify candidate epigenetically inactivated TSGs in renal cell carcinoma (RCC), we monitored changes in gene expression in four RCC cell lines after treatment with the demethylating agent 5-azacytidine. This enabled us to identify HAI-2/SPINT2 as a novel epigenetically inactivated candidate RCC TSG. To identify further candidate TSGs, we undertook bioinformatic and molecular genetic evaluation of a further 60 genes differentially expressed after demethylation. In addition to HAI-2/SPINT2, four genes (PLAU, CDH1, IGFB3 and MT1G) had previously been shown to undergo promoter methylation in RCC. After bioinformatic prioritisation, expression and/or methylation analysis of RCC cell lines±primary tumours was performed for 34 genes. KRT19 and CXCL16 were methylated in RCC cell lines and primary RCC; however, 22 genes were differentially expressed after demethylation but did not show primary tumour-specific methylation (methylated in normal tissue (n=1); methylated only in RCC cell lines (n=9) and not methylated in RCC cell lines (n=12)). Re-expression of CXCL16 reduced growth of an RCC cell line in vitro. In a summary, a functional epigenomic analysis of four RCC cell lines using microarrays representing 11u2009000 human genes yielded both known and novel candidate TSGs epigenetically inactivated in RCC, suggesting that this is valid strategy for the identification of novel TSGs and biomarkers.

Low-molecular-weight protein tyrosine phosphatase expression as a prognostic factor for men with metastatic hormone-naïve prostate cancer

OBJECTIVESnRecent studies have demonstrated that up-front docetaxel combined with androgen deprivation therapy (ADT) prolongs survival in some patients with metastatic hormone-naïve prostate cancer (mHNPC). However, new biomarkers for selecting personalized treatment strategies for mHNPC are warranted. We evaluated the value of low-molecular-weight protein tyrosine phosphatase (LMW-PTP) expression as a prognosticator in men with mHNPC.nnnMETHODS AND MATERIALSnA total of 48 men with mHNPC diagnosed from 2003 to 2009 were enrolled in this study. Prostate cancer tissues obtained by needle biopsies were immunohistochemically stained for LMW-PTP. Correlations between LMW-PTP expression and clinicopathological characteristics were then assessed.nnnRESULTSnAt the time of analysis, 29 (60.4%) patients were alive, whereas 15 (31.3%) and 4 (8.3%) died of prostate cancer and nonprostate cancer, respectively. Of these, 29 (60.4%) had low LMW-PTP expression and 19 (39.6%) had high expression. Median overall survival (OS) for patients with high LMW-PTP expression was not reached and that for patients with low LMW-PTP expression was 23.8 months. High LMW-PTP expression was significantly correlated with a shorter OS compared with low LMW-PTP expression (P = 0.01). Moreover, multivariate analysis showed that Gleason score (≥8 vs.≤7; HR = 5.8, 95% CI: 1.3-26.5, P = 0.02) and LMW-PTP expression (high vs. low; HR = 2.7, 95% CI: 1.0-7.2, P = 0.04) were independent prognostic factors for OS.nnnCONCLUSIONSnLMW-PTP is a potential biomarker to predict OS in patients with mHNPC.

Primary amelanotic malignant melanoma of the male urethra with inguinal lymph node metastasis successfully controlled by nivolumab: A case report

We report a rare case of primary amelanotic malignant melanoma of the male urethra. A 65-year-old man with a urethral mass was referred to our hospital. A pathological diagnosis of a biopsy specimen revealed malignant melanoma. Thereafter, the patient underwent partial penectomy. The histopathological diagnosis was amelanotic malignant melanoma of the urethra. The patient had received DAV-Feron in an adjuvant setting; however, PET-CT revealed multiple metastasis. After receiving more than 10 cycles of nivolumab, the accumulation of FDG was no longer observed on PET-CT. The patient is currently free from recurrence at 20 months after nivolumab treatment.