Syndecan Family Gene and Protein Expression and Their Prognostic Values for Prostate Cancer.

Prostate cancer (PCa) is the leading cause of cancer-associated mortality in men, and new biomarkers are still needed. The expression pattern and protein tissue localization of proteoglycans of the syndecan family (SDC 1-4) and syntenin-1 (SDCBP) were determined in normal and prostatic tumor tissue from two genetically engineered mouse models and human prostate tumors. Studies were validated using SDC 1-4 and SDCBP mRNA levels and patient survival data from The Cancer Genome Atlas and CamCAP databases. RNAseq showed increased expression of Sdc1 in Pb-Cre4/Ptenf/f mouse Pca and upregulation of Sdc3 expression and downregulation of Sdc2 and Sdc4 when compared to the normal prostatic tissue in Pb-Cre4/Trp53f/f-;Rb1f/f mouse tumors. These changes were confirmed by immunohistochemistry. In human PCa, SDC 1-4 and SDCBP immunostaining showed variable localization. Furthermore, Kaplan-Meier analysis showed that patients expressing SDC3 had shorter prostate-specific survival than those without SDC3 expression (log-rank test, p = 0.0047). Analysis of the MSKCC-derived expression showed that SDC1 and SDC3 overexpression is predictive of decreased biochemical recurrence-free survival (p = 0.0099 and p = 0.045, respectively), and SDC4 overexpression is predictive of increased biochemical recurrence-free survival (p = 0.035). SDC4 overexpression was associated with a better prognosis, while SDC1 and SDC3 were associated with more aggressive tumors and a worse prognosis.

Transcriptional regulators and regulatory pathways involved in prostate gland adaptation to a hypoandrogen environment.

Anti-androgen therapies, including orchiectomy, are effective at promoting prostate cancer remission, but are followed by progression to the more aggressive castration-resistant prostate cancer (CRPC). Castration promotes gland and tumor shrinkage. However, prostate adaptation to androgen deprivation involves striking parallel events, all requiring changes in gene expression. We hypothesized that transcription factors (TF) and other transcription-related genes are needed to orchestrate those changes. In this work, downstream analysis using bioinformatic tools and published microarray data allowed us to identify sixty transcriptional regulators (including 10 TF) and to integrate their function in physiologically relevant networks. Functional associations revealed a connection between Arnt, Bhlhe41 and Dbp circadian rhythm genes with the Ar circuitry and a small gene network centered in Pex14, which might indicate a previously unanticipated metabolic shift. We have also identified human homologs and mapped the corresponding genes to human chromosome regions commonly affected in prostate cancer, with particular attention to the PTEN/HHEX/MXI1 cluster at 10q23-25 (frequently deleted in PCa) and to MAPK1 at 22q11.21 (delete in intermediate risk but not in high risk PCa). Twenty genes were found mutated or with copy number alterations in at least five percent of three cancer cohorts and six of them (PHOX2A, NFYC, EST2, EIF2S1, SSRP1 and PARP1) associated with impacted patient survival. These changes are specific to the adaptation to the hypoandrogen environment and seem important for the progression to CRPC when mutated.

The role of SDF1 in prostate epithelial morphogenesis.

Androgens induce rat prostate induction from the urogenital sinus epithelium at embryonic day 17.5. Subsequent morphogenesis, including epithelial cord growth, branching, and canalization, results from concerted paracrine interactions with the stroma. A significant number of paracrine factors bind heparan sulfate (HS). We hypothesized that interfering with overall sulfation could disrupt the signaling mediated by HS-binding factors and that the undersulfated environment would allow investigation of individual exogenous morphogens. First, we investigated whether acinar morphogenesis involved HS-proteoglycan expression and found that syndecans 1 and 3 were upregulated in RWPE1 cells in the transition from two- to three-dimensional (3D) Matrigel, capable of promoting spheroid formation. We then investigated whether sodium chlorate, a general sulfation inhibitor, interfered with spheroid formation by RWPE1 cells and acinar morphogenesis in ex vivo ventral prostate (VP) organ culture. As expected, treatment with sodium chlorate inhibited spheroid formation by RWPE1 cells in 3D culture. Chlorate also inhibited ex vivo VP epithelial branching and canalization, resulting in long branchless epithelial structures. We then investigated whether the HS-binding factors, FGF10, TGFß1, and SDF1, could reverse the effect of sodium chlorate. Although no effect was seen in the FGF10- and TGFß1-treated samples, SDF1 promoted epithelial canalization in the low sulfated environment, highlighting its specific role in lumen formation. Altogether, the results show that sodium chlorate perturbed prostate morphogenesis and allowed investigation of factors involved in branching and/or canalization, implicating SDF1 signaling in epithelial canalization.

New transcription factors involved with postnatal ventral prostate gland development in male Wistar rats during the first week.

AIMS: The high incidence in men of prostatic diseases, including benign and malignant tumors, makes the understanding of prostate development and biology very important. Understanding the organogenesis of the prostate gland has been a substantial challenge as "prostatic code" is not well defined at the present time. The novelty of this work lies in unveiling new transcription factors (TFs) during neonatal ventral prostate (VP) gland development in male Wistar rats. MAIN METHODS: The techniques of qRT-PCR and immunohistochemistry have been employed to perform this work while the VP gland was obtained from neonatal rats at day zero (the day of birth) day 3 and 6. KEY FINDINGS: 16 TFs were studied and we found an increased expression of Eya2, Lhrh and Znf142, invariable levels of Znf703 and Dbp, and decreased expression of 11 others at postnatal development day 3 and 6 as compared to day zero. ZNF703 was found by immunohistochemistry in epithelial cells at days 0, 3 and 6. qRT-PCR for Eya2 and Dmrt2 showed the highest and lowest fold change for them respectively, and immunohistochemistry showed that the former is being expressed at the three selected time points while the latter appears to be diminishing with very few cells expressing it until day 6. SIGNIFICANCE: Results from this work is reporting the role of these TFs for the first time and will significantly contribute to the current understanding of the development and branching morphogenesis of the neonatal VP gland during the first week of postnatal development.

Transcription factors involved in prostate gland adaptation to androgen deprivation.

Androgens regulate prostate physiology, and exert their effects through the androgen receptor. We hypothesized that androgen deprivation needs additional transcription factors to orchestrate the changes taking place in the gland after castration and for the adaptation of the epithelial cells to the androgen-deprived environment, ultimately contributing to the origin of castration-resistant prostate cancer. This study was undertaken to identify transcription factors that regulate gene expression after androgen deprivation by castration (Cas). For the sake of comparison, we extended the analysis to the effects of administration of a high dose of 17ß-estradiol (E2) and a combination of both (Cas+E2). We approached this by (i) identifying gene expression profiles and enrichment terms, and by searching for transcription factors in the derived regulatory pathways; and (ii) by determining the density of putative transcription factor binding sites in the proximal promoter of the 10 most up- or down-regulated genes in each experimental group in comparison to the controls Gapdh and Tbp7. Filtering and validation confirmed the expression and localized EVI1 (Mecom), NFY, ELK1, GATA2, MYBL1, MYBL2, and NFkB family members (NFkB1, NFkB2, REL, RELA and RELB) in the epithelial and/or stromal cells. These transcription factors represent major regulators of epithelial cell survival and immaturity as well as an adaptation of the gland as an immune barrier in the absence of functional stimulation by androgens. Elk1 was expressed in smooth muscle cells and was up-regulated after day 4. Evi1 and Nfy genes are expressed in both epithelium and stroma, but were apparently not affected by androgen deprivation.

Desquamation is a novel phenomenon for collective prostate epithelial cell deletion after castration.

The mechanism underlying castration-induced prostate regression, which is a classical physiological concept translated into the therapeutic treatment of advanced prostate cancer, involves epithelial cell apoptosis. In searching for events and mechanisms contributing to prostate regression in response to androgen modulation, we have frequently observed the collective deletion of epithelial cells. This work was undertaken to characterize this phenomenon hereafter named desquamation and to verify its presence after 17ß-estradiol (E2) administration. Electron microscopy revealed that the desquamating cells had preserved cell-cell junctions and collapsed nuclear contents. The TUNEL reaction was negative for these cells, which were also negative for cleaved caspases-8, -9, -3 and nuclear apoptosis-inducing factor. Detailed analyses revealed that the condensed chromatin was first affected detaching from the nuclear lamina, which was observable after lamin A immunohistochemistry, suggesting the lack of lamin A degradation. A search in animals treated with supraphysiological E2 employed as an alternative anti-androgen treatment revealed no desquamation. The combined treatment (Cas + E2 group) caused changes particular to each treatment, including desquamation. In conclusion, desquamation appeared as a novel phenomenon contributing to collective prostate epithelial cell deletion, distinct from the classical castration-induced apoptosis and particular to the androgen deprivation resulting from surgical castration, and should be considered as part of the mechanisms promoting organ regression.