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Ta-Chun Yuan, Suresh Veeramani, Fen-Fen Lin, Dmitry Kondrikou, Stanislav Zelivianski, Tsukasa Igawa, Dev Karan, Surinder K. Batra, and Ming-Fong Lin

Neuroendocrine (NE) cells are the minor cell populations in normal prostate epithelial compartments. During prostate carcinogenesis, the number of NE cells in malignant lesions increases, correlating with its tumorigenicity and hormone-refractory growth. It is thus proposed that cancerous NE cells promote prostate cancer (PCa) cell progression and its androgen-independent proliferation, although the origin of the cancerous NE cells is not clear. To investigate the role of cancerous NE cells in prostate carcinogenesis, we characterized three NE subclone cell lines–NE-1.3, NE-1.8 and NE-1.9, which were transdifferentiated from androgen-sensitive human PCa LNCaP cells by culturing in an androgen-depleted environment, resembling clinical androgen-ablation therapy. These subclone cells acquire many features of NE cells seen in clinical prostate carcinomas, for example exhibiting a neuronal morphology and expressing multiple NE markers, including neuron-specific enolase, chromogranin B, neurotensin, parathyroid hormone-related peptide, and to a lesser degree for chromogranin A, while lacking androgen receptor (AR) or prostate specific antigen (PSA) expression. These cells represent terminally differentiated stable cells because after 3 months of re-culturing in a medium containing androgenic activity, they still retained the NE phenotype and expressed NE markers. Despite these NE cells having a slow growth rate, they readily developed xenograft tumors. Furthermore, media conditioned by these NE cells exhibited a stimulatory effect on proliferation and PSA secretion by LNCaP cells in androgen-deprived conditions. Additionally, we found that receptor protein tyrosine phosphatase α plays a role in upregulating multiple NE markers and acquiring the NE phenotype. These NE cells thus represent cancerous NE cells and could serve as a useful cell model system for investigating the role of cancerous NE cells in hormone-refractory proliferation of PCa cells.

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Masaki Shiota, Shuichi Tatarano, Toshiyuki Kamoto, Hideyasu Matsuyama, Hideki Sakai, Tsukasa Igawa, Tomomi Kamba, Naohiro Fujimoto, Yuya Sekine, Hiroko Kimura, Shintaro Narita, Naoki Terada, Yukihide Momozawa, Shusuke Akamatsu, Tomonori Habuchi, Akira Yokomizo, Seiji Naito, and Masatoshi Eto

Androgen-deprivation therapy (ADT) has been widely used for the treatment of advanced prostate cancer. However, prognosis and adverse events (AEs) vary among patients. This study aimed to identify genetic markers able to predict the outcome of ADT. Japanese patients treated with primary ADT for advanced prostate cancer in the KYUCOG-1401 trial were enrolled as a development set. A distinct population of advanced prostate cancer cases treated with ADT was included as a validation set. Single-nucleotide polymorphisms (SNPs) associated with radiographic progression-free survival (rPFS) at 1 year and AEs including de novo diabetes mellitus (DM), arthralgia, and de novo dyslipidemia were identified in the development set by a genome-wide association study (GWAS). The SNPs associated with rPFS in the development study were then genotyped in the validation set. GWAS followed by validation identified SNPs (rs76237622 in PRR27 and rs117573572 in MTAP) that were associated with overall survival (OS) in ADT. A genetic prognostic model using these SNPs showed excellent predictive efficacy for PFS and OS in ADT. In addition, GWAS showed that several SNPs were associated with de novo DM, arthralgia, and de novo dyslipidemia in ADT. This study identified novel multiple SNPs that correlated with outcomes in ADT. Future studies on correlations affecting the therapeutic efficacy of ADT-based combination therapies would make a valuable contribution to the development of personalized medicine.