Impact of Androgen Receptor Activity on Prostate-Specific Membrane Antigen Expression in Prostate Cancer Cells

Prostate-specific membrane antigen (PSMA) is an essential molecular regulator of prostate cancer (PCa) progression coded by the FOLH1 gene. The PSMA protein has become an important factor in metastatic PCa diagnosis and radioligand therapy. However, low PSMA expression is suggested to be a resistance mechanism to PSMA-based imaging and therapy. Clinical studies revealed that androgen receptor (AR) inhibition increases PSMA expression. The mechanism has not yet been elucidated. Therefore, this study investigated the effect of activation and inhibition of androgen signaling on PSMA expression levels in vitro and compared these findings with PSMA levels in PCa patients receiving systemic therapy. To this end, LAPC4, LNCaP, and C4-2 PCa cells were treated with various concentrations of the synthetic androgen R1881 and antiandrogens. Changes in FOLH1 mRNA were determined using qPCR. Open access databases were used for ChIP-Seq and tissue expression analysis. Changes in PSMA protein were determined using western blot. For PSMA staining in patients’ specimens, immunohistochemistry (IHC) was performed. Results revealed that treatment with the synthetic androgen R1881 led to decreased FOLH1 mRNA and PSMA protein. This effect was partially reversed by antiandrogen treatment. However, AR ChIP-Seq analysis revealed no canonical AR binding sites in the regulatory elements of the FOLH1 gene. IHC analysis indicated that androgen deprivation only resulted in increased PSMA expression in patients with low PSMA levels. The data demonstrate that AR activation and inhibition affects PSMA protein levels via a possible non-canonical mechanism. Moreover, analysis of PCa tissue reveals that low PSMA expression rates may be mandatory to increase PSMA by androgen deprivation.     

重复穿刺活检中高级别上皮内瘤对前列腺癌的预测价值

Objective: The significance of isolated high-grade prostatic intraepithelial neoplasia in initial biopsy as an predictor for prostate cancer has been extensively research, and the true relationship remnant is no clear till now. The aim of this study is to evaluate prediction value of cancer on repeat biopsy in patients with high-grade prostatic intraepithelial neoplasia,using multivariate analysis. Methods: Thirty-eight men with a diagnosis of isolated high-grade prostatic intraepithelial neoplasia in initial needle biopsy were studies, in the Fist Affiliated Hospital of Medical School of Xi'an Jiaotong University, from January 2003 to March 2009. These samples were using immunostaining of p63 and 34βE12 and P504s, with a median follow-up of 525 (range, 7 to 1650) days, and to researched the incidence of subsequent prostate cancer, and to predicted the risk of prostate cancer in clinicopathological parameters of isolated high-grade prostatic intraepithelial neoplasia on repeat biopsies by logistic regression analysis. Results: There were 10 of 38 (26.3%) men with prostate cancer on repeat biopsies after diagnosis isolated high-grade prostatic intraepithelial neoplasia in initial biopsy, of the rates of prostate cancer were 80% for micropapillary and 75% for cribriform high-grade prostatic intraepithelial neoplasia (P < 0.05), respectively. The positive cores of isolated high-grade prostatic intraepithelial neoplasia was the important for the risk of prostate cancer using Multifactor logistic regression analysis. The time range in 30 to 690 days was stronger risk for prostate cancer detection after diagnosis isolated HGPIN in initial biopsy. p63 and 34βE12 were disrupted positive expression, and P504S was weak positive expression in the 61% isolated high-grade prostatic intraepithelial neoplasia. Conclusion: Isolated high-grade prostatic intraepithelial neoplasia on repeat biopsy conferred a 26.3% risk of prostate cancer, and this risk level is lower than the previously reported risk of 24% to 58%. The number of positive cores and the histopathological pattern with high-grade prostatic intraepithelial neoplasia on initial biopsy was significantly associated with the risk of cancer.     

Complexing the Oncolytic Adenoviruses Ad∆∆ and Ad-3∆-A20T with Cationic Nanoparticles Enhances Viral Infection and Spread in Prostate and Pancreatic Cancer Models

Oncolytic adenoviruses (OAd) can be employed to efficiently eliminate cancer cells through multiple mechanisms of action including cell lysis and immune activation. Our OAds, AdΔΔ and Ad-3∆-A20T, selectively infect, replicate in, and kill adenocarcinoma cells with the added benefit of re-sensitising drug-resistant cells in preclinical models. Further modifications are required to enable systemic delivery in patients due to the rapid hepatic elimination and neutralisation by blood factors and antibodies. Here, we show data that support the use of coating OAds with gold nanoparticles (AuNPs) as a possible new method of virus modification to help augment tumour uptake. The pre-incubation of cationic AuNPs with AdΔΔ, Ad-3∆-A20T and wild type adenovirus (Ad5wt) was performed prior to infection of prostate/pancreatic cancer cell lines (22Rv, PC3, Panc04.03, PT45) and a pancreatic stellate cell line (PS1). Levels of viral infection, replication and cell viability were quantified 24–72 h post-infection in the presence and absence of AuNPs. Viral spread was assessed in organotypic cultures. The presence of AuNPs significantly increased the uptake of Ad∆∆, Ad-3∆-A20T and Ad5wt in all the cell lines tested (ranging from 1.5-fold to 40-fold), compared to virus alone, with the greatest uptake observed in PS1, a usually adenovirus-resistant cell line. Pre-coating the AdΔΔ and Ad-3∆-A20T with AuNPs also increased viral replication, leading to enhanced cell killing, with maximal effect in the most virus-insensitive cells (from 1.4-fold to 5-fold). To conclude, the electrostatic association of virus with cationic agents provides a new avenue to increase the dose in tumour lesions and potentially protect the virus from detrimental blood factor binding. Such an approach warrants further investigation for clinical translation.