Primary stromal cells isolated from human various histological/pathological prostate have different phenotypes and tumor promotion role / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>Prostate stromal cells are known to regulate epithelial growth as well as support and maintain epithelial function. However, how stromal cells regulate epithelial cells and what differences among various histological/pathological prostate stromal cells in prostate cancer progression still remain unclear. This study aimed to investigate the different phenotypes of human various histological/pathological prostate stromal cells, and their role in tumor promotion.</p><p><b>METHODS</b>The different phenotypes of the human normal prostatic peripheral zonal primary stromal cells (NPPF), transitional zonal primary stromal cells (NPTF), and prostate cancer associated primary stromal cells (CAF) were examined with growth curves and Annexin V-fluorescein isothiocyanate (FITC) assay. The different effects on prostate cancer cell line C4-2B by NPPF, NPTF, and CAF were examined with MTT assay and Annexin V-FITC assay. The gene expression of different histological/pathological prostate stromal cells was profiled by microarray and hierarchical cluster analysis.</p><p><b>RESULTS</b>The growth rate of NPPF, NPTF and CAF gradually increased, followed by decreasing apoptosis. In vitro stromal-C4-2B cell line co-culture models, the proliferation and apoptosis of C4-2B cell line were differently affected by human various histological/pathological prostate stromal cells. CAF showed the most powerful effect to C4-2B cell line, as opposed to a weakest effect of NPTF. Microarray and hierarchical cluster analysis showed that the differentially expressed genes of CAF and NPPF were less than NPPF and NPTF, or CAF and NPTF. This was consistent with clinical observations that prostate cancer mostly derived from the peripheral zone and does not usually occur in the transitional zone.</p><p><b>CONCLUSION</b>NPPF, NPTF and CAF possess extremely different biological characteristics and gene expression, which may play an important role in genesis and development of prostate cancer.</p>

Proportion of intermediate epithelial cells and human prostate cancer / 中华男科学杂志

<p><b>OBJECTIVE</b>To study the different proportions of intermediate epithelial cells in human prostate cancer tissue and their clinical significance.</p><p><b>METHODS</b>We performed immunohistochemical staining for Cytokeratin 5 (CK5) and Cytokeratin 8 (CK8) on 60 samples of human prostate cancer, determined the proportions of intermediate epithelial cells in the cancer tissue, and classified the samples into 2 types, one with a majority of intermediate epithelial cells (CaP-INT, n = 32), and the other composed mostly of luminal epithelial cells (CaP-LUM, n = 28). Then we compared the 2 types of prostate cancer in the expression of the androgen receptor (AR), age of the patient, serum t-PSA, prostate volume, Gleason score, clinical stage, androgen resistance, and incidence of distant metastasis.</p><p><b>RESULTS</b>CaP-INT showed a significantly lower expression of AR ([24.42 +/- 11.41] %) and a higher incidence of distant metastasis (n = 14) than CaP-LUM ([77.21 +/- 10.22] % and n = 4) (P < 0.05). In the CaP-INT group, 6 of the 26 endocrinologically treated cases developed into androgen-independent prostate cancer (AIPC), while in the CaP-LUM group, only 1 out of 23 (P < 0.05). The former also showed remarkably higher clinical stages than the latter (P < 0.05), but no significant differences were found in age, serum t-PSA, prostate volume and Gleason score between the two groups (P > 0.05).</p><p><b>CONCLUSION</b>A higher proportion of intermediate epithelial cells may lead to increased invasiveness and metastasis of human prostate cancer.</p>

Chimeric molecules facilitate the degradation of androgen receptors and repress the growth of LNCaP cells / 亚洲男科学杂志(英文版)

Post-translational degradation of protein plays an important role in cell life. We employed chimeric molecules (dihydrotestosterone-based proteolysis-targeting chimeric molecule [DHT-PROTAC]) to facilitate androgen receptor (AR) degradation via the ubiquitin-proteasome pathway (UPP) and to investigate the role of AR in cell proliferation and viability in androgen-sensitive prostate cancer cells. Western blot analysis and immunohistochemistry were applied to analyse AR levels in LNCaP cells after DHT-PROTAC treatment. Cell counting and the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) cell viability assay were used to evaluate cell proliferation and viability after AR elimination in both LNCaP and PC-3 cells. AR was tagged for elimination via the UPP by DHT-PROTAC, and this could be blocked by proteasome inhibitors. Degradation of AR depended on DHT-PROTAC concentration, and either DHT or an ALAPYIP-(arg)(8) peptide could compete with DHT-PROTAC. Inhibition of cell proliferation and decreased viability were observed in LNCaP cells, but not in PC-3 or 786-O cells after DHT-PROTAC treatment. These data indicate that AR elimination is facilitated via the UPP by DHT-PROTAC, and that the growth of LNCaP cells is repressed after AR degradation.

Androgen receptor functioned as a suppressor in the prostate cancer cell line PC3 in vitro and in vivo / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>Prostate cancer is one of the most common urogenital tumors in the world with an increasing incidence in China. Androgen deprivation therapy is the major therapeutic option for advanced prostate cancer. However, the role of androgen receptor (AR) in hormone-refractory prostate cancer still remains unclear. This work aimed to investigate the role of AR in an androgen independent prostate cancer cell line by in vitro and in vivo studies.</p><p><b>METHODS</b>The role of AR in the proliferation and invasion/metastasis ability of PC3-AR9 (a PC3 stable clone expressing human AR driven by natural human AR promoter) were examined with MTT assay, soft agar assay, chamber invasion assay, wound healing assay, and also with orthotopic xenograft mouse model.</p><p><b>RESULTS</b>Restoring androgen receptor in PC3 cells resulted in decreased proliferation and invasion/metastasis ability in MTT, soft agar, chamber invasion and wound healing assay. In the mouse orthotopic xenograft model, PC3-AR9 resulted in smaller primary tumors and metastasis tumors, with a lower proliferation rate and higher apoptosis rate.</p><p><b>CONCLUSION</b>The AR might function as a tumor suppressor in PC3 cells both in vitro and in vivo.</p>

Targeted degradation of androgen receptors in androgen-independent prostate cancer cells: an experimental study / 中华男科学杂志

<p><b>OBJECTIVE</b>To investigate targeted degradation of the androgen receptor (AR) by chimeric molecules (DHT-PROTAC) via the ubiquitin-proteasome pathway in androgen-independent prostate cancer CA-2B cells, and explore the proliferation, secretion and apoptosis of the treated cells.</p><p><b>METHODS</b>C4-2B cells were treated with DHT-PROTAC, and then the expressions of the AR protein and caspase3 in the C4-2B cells were detected by immunohistochemistry and Western blot. The concentration of PSA in the supernatant was examined by ELISA. The cells were counted and their proliferation analyzed by a growth curve. The inhibitory effect on the growth of C4-2B cells was evaluated by MIT assay.</p><p><b>RESULTS</b>Compared with the control group, the DHT-PROTAC-treated group showed an obviously decreased expression of AR proteins with a significant attenuation of the band signals (P < 0.05), a 40% reduction of the AR-positive cells and a 60% decrease of the PSA concentration in the supernatant (P < 0.05). DHT-PROTAC exhibited an inhibitory effect on the C4-2B cells in a time-dependant manner (P < 0.05).</p><p><b>CONCLUSION</b>The chimeric molecule (DHT-PROTAC) can target the degradation of androgen receptors, reduce the secretion of PSA and repress the in vitro growth of C4-2B cells.</p>