DNA methylation of E-cadherin is a priming mechanism for prostate development

PCMT1 regulates the migration, invasion, and apoptosis of prostate cancer through modulating the PI3K/AKT/GSK-3β pathway

Protein L-isoaspartate (D-aspartate) O-methyltransferase (PCMT1) is a repair enzyme that catalyzes the conversion of isomerized aspartic acid (iso-Asp) residues into their normal structure, thereby restoring the configuration and function of proteins. Studies have shown that PCMT1 is overexpressed in several tumors and affects patients' prognosis. However, there are few reports on the role of PCMT1 in prostate cancer (PCa). In the present research, with the assistance of The Cancer Genome Atlas Program (TCGA) database, we found that PCMT1 was overexpressed in PCa tissues. The results of quantitative reverse transcription-polymerase chain reaction (qRT-PCR), western blot and immunohistochemistry staining also showed that PCMT1 expression was significantly increased in PCa tissues and cell lines. In PCa clinical samples, PCMT1 expression was closely related to Gleason score, clinical stage, lymph node metastasis and bone metastasis. The experiments of overexpression and knockdown of PCMT1 in vitro or in vivo showed that PCMT1 can significantly promote the proliferation, migration and invasion of PCa cells, inhibit cell apoptosis, and promote the growth of PCa. We furthermore confirmed that PCMT1 regulated the migration, invasion and apoptosis of PCa cells by modulating the phosphatidylinositol 3-kinase/AKT kinase/glycogen-synthase kinase-3β (PI3K/AKT/GSK-3β) signaling pathway. Collectively, PCMT1 plays a cancer-facilitative role in PCa by promoting the proliferation, migration and invasion of PCa cells, and inhibiting apoptosis. Therefore, PCMT1 is considered to represent a novel target for treating PCa.

Regulation of SPDEF expression by DNA methylation in advanced prostate cancer

Introduction

Prostate cancer (PCa) presents a significant health challenge in men, with a substantial number of deaths attributed to metastatic castration resistant PCa (mCRPC). Moreover, African American men experience disproportionately high mortality rates due to PCa. This study delves into the pivotal role of SPDEF, a prostate specific Ets transcription factor, and its regulation by DNA methylation in the context of PCa progression.

Methods

We performed Epigenetic reprogramming using daily treatment with non-toxic dose of 5Aza-2-deoxycytidine (5Aza-dC) for two weeks to assess its impact on PDEF expression in prostate cancer cells. Next, we conducted functional studies on reprogrammed cells, including cell migration (wound-healing assay), invasion (Boyden-Chamber test), and proliferation (MTT assay) to comprehensively evaluate the consequences of altered PDEF expression. We used bisulfite sequencing (BSP) to examine DNA methylation at SPDEF promoter. Simultaneously, we utilized siRNA-mediated targeting of key DNMTs (DNMT1, DNMT3A, and DNMT3B) to elucidate their specific role in regulating PDEF. We measured mRNA and protein expressions using qRT-PCR and immune-blotting techniques, respectively.

Results

In this report, we observed that: a) there is a gradual decrease in SPDEF expression with a concomitant increase in methylated CpG sites within the SPDEF gene during prostate cancer progression from lower to higher Gleason grade; b) Expression of DNMT's (DNMT1, 3a and 3b) is increased during prostate cancer progression, and there is an inverse correlation between SPDEF and DNMT expression; c) SPDEF levels are decreased in RC77/T, a line of PCa cells from African American origin similar to PC3 and DU145 cells (CRPC cells), as compared to LNCaP cells , a line of androgen dependent cells,; d) the 5' CpG island of SPDEF gene are hypermethylated in SPDEF-negative CRPC ( PC3, DU145 and RC77/T) cell lines but the same regions are hypomethylated in SPDEF-positive castrate sensitive (LNCaP) cell line ; (e) expression of SPDEF in PCa cells lacking SPDEF decreases cell migration and invasion, but has no significant effect on cell proliferation, and; (f) treatment with the demethylating agent, 5-aza-2'-deoxycytidine, or silencing of the DNMT's by siRNA, partially restores SPDEF expression in SPDEF-negative PCa cell lines, and decreases cell migration and invasion.

Discussion

These results indicate hypermethylation is a prevalent mechanism for decreasing SPDEF expression during prostate cancer progression. The data demonstrate that loss of SPDEF expression in prostate cancer cells, a critical step in cellular plasticity, results from a potentially reversible process of aberrant DNA methylation. These studies suggest DMNT activity as a potential therapeutic vulnerability that can be exploited for limiting cellular plasticity, tumor progression, and therapy resistance in prostate cancer.

Human prostate organoid generation and the identification of prostate development drivers using inductive rodent tissues

The reactivation of developmental genes and pathways during adulthood may contribute to pathogenesis of diseases such as prostate cancer. Analysis of the mechanistic links between development and disease could be exploited to identify signalling pathways leading to disease in the prostate. However, the mechanisms underpinning prostate development require further characterisation to interrogate fully the link between development and disease. Previously, our group developed methods to produce prostate organoids using induced pluripotent stem cells (iPSCs). Here, we show that human iPSCs can be differentiated into prostate organoids using neonatal rat seminal vesicle mesenchyme in vitro. The organoids can be used to study prostate development or modified to study prostate cancer. We also elucidated molecular drivers of prostate induction through RNA-sequencing analyses of the rat urogenital sinus and neonatal seminal vesicles. We identified candidate drivers of prostate development evident in the inductive mesenchyme and epithelium involved with prostate specification. Our top candidates included Spx, Trib3, Snai1, Snai2, Nrg2 and Lrp4. This work lays the foundations for further interrogation of the reactivation of developmental genes in adulthood, leading to prostate disease.

A Review of Prostate Organogenesis and a Role for iPSC-Derived Prostate Organoids to Study Prostate Development and Disease

The prostate is vulnerable to two major age-associated diseases, cancer and benign enlargement, which account for significant morbidity and mortality for men across the globe. Prostate cancer is the most common cancer reported in men, with over 1.2 million new cases diagnosed and 350,000 deaths recorded annually worldwide. Benign prostatic hyperplasia (BPH), characterised by the continuous enlargement of the adult prostate, symptomatically afflicts around 50% of men worldwide. A better understanding of the biological processes underpinning these diseases is needed to generate new treatment approaches. Developmental studies of the prostate have shed some light on the processes essential for prostate organogenesis, with many of these up- or downregulated genes expressions also observed in prostate cancer and/or BPH progression. These insights into human disease have been inferred through comparative biological studies relying primarily on rodent models. However, directly observing mechanisms of human prostate development has been more challenging due to limitations in accessing human foetal material. Induced pluripotent stem cells (iPSCs) could provide a suitable alternative as they can mimic embryonic cells, and iPSC-derived prostate organoids present a significant opportunity to study early human prostate developmental processes. In this review, we discuss the current understanding of prostate development and its relevance to prostate-associated diseases. Additionally, we detail the potential of iPSC-derived prostate organoids for studying human prostate development and disease.

CXCR4 Regulates Temporal Differentiation via PRC1 Complex in Organogenesis of Epithelial Glands

CXC-chemokine receptor type 4 (CXCR4), a 7-transmembrane receptor family member, displays multifaceted roles, participating in immune cell migration, angiogenesis, and even adipocyte metabolism. However, the activity of such a ubiquitously expressed receptor in epithelial gland organogenesis has not yet been fully explored. To investigate the relationship between CXCL12/CXCR4 signaling and embryonic glandular organogenesis, we used an ex vivo culture system with live imaging and RNA sequencing to elucidate the transcriptome and protein-level signatures of AMD3100, a potent abrogating reagent of the CXCR4-CXCL12 axis, imprinted on the developing organs. Immunostaining results showed that CXCR4 was highly expressed in embryonic submandibular gland, lung, and pancreas, especially at the periphery of end buds containing numerous embryonic stem/progenitor cells. Despite no significant increase in apoptosis, AMD3100-treated epithelial organs showed a retarded growth with significantly slower branching and expansion. Further analyses with submandibular glands revealed that such responses resulted from the AMD3100-induced precocious differentiation of embryonic epithelial cells, losing mitotic activity. RNA sequencing analysis revealed that inhibition of CXCR4 significantly down-regulated polycomb repressive complex (PRC) components, known as regulators of DNA methylation. Treatment with PRC inhibitor recapitulated the AMD3100-induced precocious differentiation. Our results indicate that the epigenetic modulation by the PRC-CXCR12/CXCR4 signaling axis is crucial for the spatiotemporal regulation of proliferation and differentiation of embryonic epithelial cells during embryonic glandular organogenesis.

Prostate-Specific Deletion of Cdh1 Induces Murine Prostatic Inflammation and Bladder Overactivity

Benign prostatic hyperplasia (BPH) is an age-related debilitating prostatic disease that is frequently associated with prostatic inflammation and bothersome lower urinary tract symptoms (LUTS). Animal models have shown that formalin- and bacterial-induced prostatic inflammation can induce bladder dysfunction; however, the underlying mechanisms contributing to prostatic inflammation in BPH and bladder dysfunction are not clear. We previously reported that E-cadherin expression in BPH is downregulated in hyperplastic nodules compared with expression in adjacent normal tissues. Here, we explored the potential consequences of prostatic E-cadherin downregulation on the prostate and bladder in vivo using an inducible murine model of prostate luminal epithelial-specific deletion of Cdh1. The prostate-specific antigen (PSA)-CreERT2 transgenic mouse strain expressing tamoxifen-inducible CreERT2 recombinase driven by a 6-kb human PSA promoter/enhancer was crossed with the B6.129-Cdh1tm2Kem/J mouse to generate bigenic PSA-CreERT2/Cdh1-/- mice. Deletion of E-cadherin was induced by transient administration of tamoxifen when mice reached sexual maturity (7 weeks of age). At 21 to 23 weeks of age, the prostate, bladder, and prostatic urethra were examined histologically, and bladder function was assessed using void spot assays and cystometry. Mice with Cdh1 deletion had increased prostatic inflammation, prostatic epithelial hyperplasia, and stromal changes at 21 to 23 weeks of age, as well as changes in bladder voiding function compared with age-matched controls. Thus, loss of E-cadherin in the murine prostate could result in prostatic defects that are characteristic of BPH and LUTS, suggesting that E-cadherin downregulation could be a driving force in human BPH development and progression.

Epigenetic Modification as a Regulatory Mechanism for Spatiotemporal Dynamics of ANO1 Expression in Salivary Glands

Anoctamin1 (ANO1), a calcium activated chloride channel, is known to play a critical role in salivary secretion. In the salivary gland, ANO1 is expressed exclusively in the acinar cells, with no expression in the ductal cells. However, the mechanisms that determine this distinctive cell type-dependent expression pattern of ANO1 remain unknown. In this study, we discovered that the cell-dependent expression of ANO1 during salivary gland organogenesis is regulated by DNA methylation of ANO1 CpG islands. ANO1 CpG islands in e12 embryonic submandibular glands (eSMG) are highly methylated, but those in e14 eSMG or adult SMG are significantly unmethylated. The differential expression pattern of ANO1 in duct and acini is defined at e14. Artificial demethylation by treatment with the demethylating agent 5-aza-2'-deoxycytidine (5-Aza-CdR), induced the expression of ANO1 in both the ductal cell line Human Submandibular Gland (HSG) and in the duct cells of adult mouse SMG. During the trans-differentiation in Matrigel of duct-origin HSG cells into acinar-like phenotype, significant demethylation of ANO1 CpG islands is observed. This may be due to the reduced expression of DNA methyltransferase (DNMT) 3a and 3b. These results suggest that the differential expression of ANO1 in salivary glands during organogenesis and differentiation is mainly regulated by epigenetic demethylation of the ANO1 gene.

E-cadherin is downregulated in benign prostatic hyperplasia and required for tight junction formation and permeability barrier in the prostatic epithelial cell monolayer

BACKGROUND

We previously reported the presence of prostate-specific antigen (PSA) in the stromal compartment of benign prostatic hyperplasia (BPH). Since PSA is expressed exclusively by prostatic luminal epithelial cells, PSA in the BPH stroma suggests increased tissue permeability and the compromise of epithelial barrier integrity. E-cadherin, an important adherens junction component and tight junction regulator, is known to exhibit downregulation in BPH. These observations suggest that the prostate epithelial barrier is disrupted in BPH and E-cadherin downregulation may increase epithelial barrier permeability.

METHODS

The ultra-structure of cellular junctions in BPH specimens was observed using transmission electron microscopy (TEM) and E-cadherin immunostaining analysis was performed on BPH and normal adjacent specimens from BPH patients. In vitro cell line studies using benign prostatic epithelial cell lines were performed to determine the impact of small interfering RNA knockdown of E-cadherin on transepithelial electrical resistance and diffusion of fluorescein isothiocyanate (FITC)-dextran in transwell assays.

RESULTS

The number of kiss points in tight junctions was reduced in BPH epithelial cells as compared with the normal adjacent prostate. Immunostaining confirmed E-cadherin downregulation and revealed a discontinuous E-cadherin staining pattern in BPH specimens. E-cadherin knockdown increased monolayer permeability and disrupted tight junction formation without affecting cell density.

CONCLUSIONS

Our results indicate that tight junctions are compromised in BPH and loss of E-cadherin is potentially an important underlying mechanism, suggesting targeting E-cadherin loss could be a potential approach to prevent or treat BPH.

Epithelial DNA methyltransferase-1 regulates cell survival, growth and maturation in developing prostatic buds

DNA methyltransferase 1 (DNMT1) is required for embryogenesis but roles in late forming organ systems including the prostate, which emerges from the urethral epithelium, have not been fully examined. We used a targeted genetic approach involving a Shhcre recombinase to demonstrate requirement of epithelial DNA methyltransferase-1 (Dnmt1) in mouse prostate morphogenesis. Dnmt1 mutant urethral cells exhibit DNA hypomethylation, DNA damage, p53 accumulation and undergo cell cycle arrest and apoptosis. Urethral epithelial cells are disorganized in Dnmt1 mutants, leading to impaired prostate growth and maturation and failed glandular development. We evaluated oriented cell division as a mechanism of bud elongation and widening by demonstrating that mitotic spindle axes typically form parallel or perpendicular to prostatic bud elongation axes. We then deployed a Shh^creERT allele to delete Dnmt1 from a subset of urethral epithelial cells, creating mosaic mutants with which to interrogate the requirement for cell division in specific prostatic bud epithelial populations. DNMT1- cell distribution within prostatic buds is not random as would be expected in a process where DNMT1 was not required. Instead, replication competent DNMT1 + cells primarily accumulate in prostatic bud margins and tips while replication impeded DNMT1- cells accumulate in prostatic bud cores. Together, these results highlight the role of DNMT1 in regulating epithelial bud formation by maintaining cell cycle progression and survival of rapidly dividing urethral epithelial cells, which can be extended to the study of other developing epithelial organs. In addition, our results show that prostatic buds consist of two epithelial cell populations with distinct molecular and functional characteristics that could potentially contribute to specialized lineages in the adult prostate.

DNA methylation in development and disease: an overview for prostate researchers

Epigenetic mechanisms including DNA methylation are critical regulators of organismal development and tissue homeostasis. DNA methylation is the transfer of methyl groups to cytosines, which adds an additional layer of complexity to the genome. DNA methylation marks are recognized by the cellular machinery to regulate transcription. Disruption of DNA methylation with aging or exposure to environmental toxins can change susceptibility to disease or trigger processes that lead to disease. In this review, we provide an overview of the DNA methylation machinery. More specifically, we describe DNA methylation in the context of prostate development, prostate cancer, and benign prostatic hyperplasia (BPH) as well as the impact of dietary and environmental factors on DNA methylation in the prostate.

Development of the human prostate

This paper provides a detailed compilation of human prostatic development that includes human fetal prostatic gross anatomy, histology, and ontogeny of selected epithelial and mesenchymal differentiation markers and signaling molecules throughout the stages of human prostatic development: (a) pre-bud urogenital sinus (UGS), (b) emergence of solid prostatic epithelial buds from urogenital sinus epithelium (UGE), (c) bud elongation and branching, (d) canalization of the solid epithelial cords, (e) differentiation of luminal and basal epithelial cells, and (f) secretory cytodifferentiation. Additionally, we describe the use of xenografts to assess the actions of androgens and estrogens on human fetal prostatic development. In this regard, we report a new model of de novo DHT-induction of prostatic development from xenografts of human fetal female urethras, which emphasizes the utility of the xenograft approach for investigation of initiation of human prostatic development. These studies raise the possibility of molecular mechanistic studies on human prostatic development through the use of tissue recombinants composed of mutant mouse UGM combined with human fetal prostatic epithelium. Our compilation of human prostatic developmental processes is likely to advance our understanding of the pathogenesis of benign prostatic hyperplasia and prostate cancer as the neoformation of ductal-acinar architecture during normal development is shared during the pathogenesis of benign prostatic hyperplasia and prostate cancer.

Peripartum Fluoxetine Reduces Maternal Trabecular Bone After Weaning and Elevates Mammary Gland Serotonin and PTHrP

Selective serotonin reuptake inhibitors (SSRIs) have been linked to osteopenia and fracture risk; however, their long-term impact on bone health is not well understood. SSRIs are widely prescribed to pregnant and breastfeeding women who might be at particular risk of bone pathology because lactation is associated with considerable maternal bone loss. We used microCT and molecular approaches to test whether the SSRI fluoxetine, administered to C57BL/6 mice from conception through the end of lactation, causes persistent maternal bone loss. We found that peripartum fluoxetine increases serum calcium and reduces circulating markers of bone formation during lactation but does not affect osteoclastic resorption. Peripartum fluoxetine exposure also enhances mammary gland endocrine function during lactation by increasing synthesis of serotonin and PTHrP, a hormone that liberates calcium for milk synthesis and reduces bone mineral volume. Peripartum fluoxetine exposure reduces the trabecular bone volume fraction at 3 months after weaning. These findings raise new questions about the long-term consequences of peripartum SSRI use on maternal health.

DNA methylation and histone modifications as epigenetic regulation in prostate cancer (Review)

Prostate cancer is the second most commonly diagnosed cancer in men in Poland after lung cancer and the third leading cause of cancer-related mortality after lung and colon cancer. The etiology of most cases of prostate cancer are not fully known, and therefore it is essential to search for the molecular basis of prostate cancer and markers for the early diagnosis of this type of cancer. Epigenetics deals with changes in gene expression that are not determined by changes in the DNA sequence. Epigenetic changes refer to changes in the structure of DNA, which are the result of DNA modification after replication and/or post-translational modification of proteins associated with DNA. In contrast to mutations, epigenetic changes are reversible and occur very rapidly. The major epigenetic mechanisms include DNA methylation, modification of histone proteins, chemical modification and chromatin remodeling changes in gene expression caused by microRNAs (miRNAs). Epigenetic changes play an important role in malignant transformation and can be specific to types of cancers including prostate cancer.

Prostate organogenesis: tissue induction, hormonal regulation and cell type specification

Prostate organogenesis is a complex process that is primarily mediated by the presence of androgens and subsequent mesenchyme-epithelial interactions. The investigation of prostate development is partly driven by its potential relevance to prostate cancer, in particular the apparent re-awakening of key developmental programs that occur during tumorigenesis. However, our current knowledge of the mechanisms that drive prostate organogenesis is far from complete. Here, we provide a comprehensive overview of prostate development, focusing on recent findings regarding sexual dimorphism, bud induction, branching morphogenesis and cellular differentiation.

Role of epithelial mesenchymal transition in prostate tumorigenesis

Globally, the cancer associated deaths are generally attributed to the spread of cancerous cells or their features to the nearby or distant secondary organs by a process known as metastasis. Among other factors, the metastatic dissemination of cancer cells is attributed to the reactivation of an evolutionary conserved developmental program known as epithelial to mesenchymal transition (EMT). During EMT, fully differentiated epithelial cells undergo a series of dramatic changes in their morphology, along with loss of cell to cell contact and matrix remodeling into less differentiated and invasive mesenchymal cells. Many studies provide evidence for the existence of EMT like states in prostate cancer (PCa) and suggest its possible involvement in PCa progression and metastasis. At the same time, the lack of conclusive evidence regarding the presence of full EMT in human PCa samples has somewhat dampened the interest in the field. However, ongoing EMT research provides new perspectives and unveils the enormous potential of this field in tailoring new therapeutic regimens for PCa management. This review summarizes the role of many transcription factors and other molecules that drive EMT during prostate tumorigenesis.

Endoplasmic reticulum protein 29 (ERp29) confers radioresistance through the DNA repair gene, O(6)-methylguanine DNA-methyltransferase, in breast cancer cells

Resistance of cancer cells to radiotherapy is a major clinical problem in cancer treatment. Therefore, understanding the molecular basis of cellular resistance to radiotherapy and identification of novel targets are essential for improving treatment efficacy for cancer patients. Our previous studies have demonstrated a significant role of ERp29 in breast cancer cell survival against doxorubicin-induced genotoxic stress. We here reported that ERp29 expression in the triple negative MDA-MB-231 breast cancer cells significantly increased cell survival against ionizing radiation. Methylation PCR array analysis identified that ERp29 expression increased promoter hypomethylation of the DNA repair gene, O⁶-methylguanine DNA-methyltransferase (MGMT), by downregulating DNA methyltransferase 1. Knockdown of MGMT in the ERp29-transfected cancer cells increased radiosensitivity, leading to a decreased post-irradiation survival. In addition, radiation treatment in the MGMT-knockdown cells elevated phosphorylation of γ-H2AX and cleavage of caspase 3, indicating that depletion of MGMT facilitates DNA double strands breaks and increases cell apoptosis. Hence, our studies prove a novel function of ERp29\MGMT in cancer cell survival against radiation. Targeting ERp29\MGMT axis may be useful for providing better treatment efficacy in combination with radiotherapy in breast cancer.

DNA methylation as a dynamic regulator of development and disease processes: spotlight on the prostate

Prostate development, benign hyperplasia and cancer involve androgen and growth factor signaling as well as stromal-epithelial interactions. We review how DNA methylation influences these and related processes in other organ systems such as how proliferation is restricted to specific cell populations during defined temporal windows, how androgens elicit their actions and how cells establish, maintain and remodel DNA methylation in a time and cell specific fashion. We also discuss mechanisms by which hormones and endocrine disrupting chemicals reprogram DNA methylation in the prostate and elsewhere and examine evidence for a reawakening of developmental epigenetic pathways as drivers of prostate cancer and benign prostate hyperplasia.

Histone acetylation regulates prostate ductal morphogenesis through a bone morphogenetic protein-dependent mechanism

BACKGROUND

Epigenetic factors influence stem cell function and other developmental events but their role in prostate morphogenesis is not completely known. We tested the hypothesis that histone deacetylase (HDAC) activity is required for prostate morphogenesis.

RESULTS

We identified the presence of class I nuclear HDACs in the mouse urogenital sinus (UGS) during prostate development and found that Hdac 2 mRNA abundance diminishes as development proceeds which is especially evident in prostatic epithelium. Blockade of HDACs with the inhibitor trichostatin A (TSA) decreased the number of prostatic buds formed in UGS explant cultures but not the number of buds undergoing branching morphogenesis. In the latter, TSA promoted an extensive branching phenotype that was reversed by exogenous NOGGIN protein, which functions as a bone morphogenetic protein (BMP) inhibitor. TSA also increased Bmp2 promoter H3K27ac abundance, Bmp2 and Bmp4 mRNA abundance, and the percentage of epithelial cells marked by BMP-responsive phosphorylated SMAD1/5/8 protein. TSA exposed UGS explants grafted under the kidney capsule of untreated host mice for continued development achieved a smaller size without an obvious difference in glandular histology compared with control treated grafts.

CONCLUSIONS

These results are consistent with an active role for HDACs in shaping prostate morphogenesis by regulating Bmp abundance.

Age and Obesity Promote Methylation and Suppression of 5α-Reductase 2: Implications for Personalized Therapy of Benign Prostatic Hyperplasia

PURPOSE

In men with symptomatic benign prostatic hyperplasia 5α-reductase inhibitors are a main modality of treatment. More than 30% of men do not respond to the therapeutic effects of 5α-reductase inhibitors. We have found that a third of adult prostate samples do not express 5α-reductase type 2 secondary to epigenetic modifications. We evaluated whether 5α-reductase type 2 expression in benign prostatic hyperplasia specimens from symptomatic men was linked to methylation of the 5α-reductase type 2 gene promoter. We also identified associations with age, obesity, cardiac risk factors and prostate specific antigen.

MATERIALS AND METHODS

Prostate samples from men undergoing transurethral prostate resection were used. We determined 5α-reductase type 2 protein expression and gene promoter methylation status by common assays. Clinical variables included age, body mass index, hypertension, hyperlipidemia, diabetes, prostate specific antigen and prostate volume. Univariate and multivariate statistical analyses were performed followed by stepwise logistic regression modeling.

RESULTS

Body mass index and age significantly correlated with methylation of the 5α-reductase type 2 gene promoter (p <0.05) whereas prostate volume, prostate specific antigen or benign prostatic hyperplasia medication did not correlate. Methylation highly correlated with 5α-reductase protein expression (p <0.0001). In a predictive model increasing age and body mass index significantly predicted methylation status and protein expression (p <0.01).

CONCLUSIONS

Increasing age and body mass index correlate with increased 5α-reductase type 2 gene promoter methylation and decreased protein expression in men with symptomatic benign prostatic hyperplasia. These results highlight the interplay among age, obesity and gene regulation. Our findings suggest an individualized epigenetic signature for symptomatic benign prostatic hyperplasia, which may be important to choose appropriate personalized treatment options.

TET1-mediated different transcriptional regulation in prostate cancer

The recent studies demonstrated that the global 5-hydroxymethylcytosine (5 hmC) level decreased in prostate cancer (PCa) involved the 5-methylcytosine (5 mC) hydroxymethylase, Ten-eleven translocation (TET)1 reduction. 5 hmC and TET1 were both revealed a dual function in bivalent domain associated with developmental regulators in embryonic stem cell model. However, the mechanism underlying the DNA methylation and hydroxymethylation change mediated by TET1 downregulation in PCa remains unclear. Herein, using BSP to assess the 5 mC level in promoters of ten specific marker gene in PCa, our results present that Cdh1, Gstp1, Pten, Apc, Runx3 and Mgmt are observed to be hypermethylated in promoters and lower expression while Cyr61, Sema3c and Ptgs2 are reversed patterns compared to the normal prostate tissues. Furthermore, using ChIP methods to investigate the H3K4me3 and H3K27me3 patterns in promoters, these four markers are all demonstrated to be associated with Polycomb-repressed characterization and upregulated in response to TET1/PRC2 reduction in PCa. Thus, our findings reveal a distinct activating and repressive function of TET1-mediated transcriptional regulation in prostate cancer.

Androgen receptor DNA methylation regulates the timing and androgen sensitivity of mouse prostate ductal development

Androgen receptor (AR) signaling initiates mouse prostate development by stimulating prostate ductal bud formation and specifying bud patterns. Curiously, however, prostatic bud initiation lags behind the onset of gonadal testosterone synthesis by about three days. This study's objective was to test the hypothesis that DNA methylation controls the timing and scope of prostate ductal development by regulating Ar expression in the urogenital sinus (UGS) from which the prostate derives. We determined that Ar DNA methylation decreases in UGS mesenchyme during prostate bud formation in vivo and that this change correlates with decreased DNA methyltransferase expression in the same cell population during the same time period. To examine the role of DNA methylation in prostate development, fetal UGSs were grown in serum-free medium and 5 alpha dihydrotestosterone (DHT) and the DNA methylation inhibitor 5'-aza-2'-deoxycytidine (5AzadC) were introduced into the medium at specific times. As a measure of prostate development, in situ hybridization was used to visualize and count Nkx3-1 mRNA positive prostatic buds. We determined that inhibiting DNA methylation when prostatic buds are being specified, accelerates the onset of prostatic bud development, increases bud number, and sensitizes the budding response to androgens. Inhibition of DNA methylation also reduces Ar DNA methylation in UGS explants and increases Ar mRNA and protein in UGS mesenchyme and epithelium. Together, these results support a novel mechanism whereby Ar DNA methylation regulates UGS androgen sensitivity to control the rate and number of prostatic buds formed, thereby establishing a developmental checkpoint.

Serotonin regulates calcium homeostasis in lactation by epigenetic activation of hedgehog signaling

Calcium homeostasis during lactation is critical for maternal and neonatal health. We previously showed that nonneuronal/peripheral serotonin [5-hydroxytryptamine (5-HT)] causes the lactating mammary gland to synthesize and secrete PTHrP in an acute fashion. Here, using a mouse model, we found that genetic inactivation of tryptophan hydroxylase 1 (Tph1), which catalyzes the rate-limiting step in peripheral 5-HT synthesis, reduced circulating and mammary PTHrP expression, osteoclast activity, and maternal circulating calcium concentrations during the transition from pregnancy to lactation. Tph1 inactivation also reduced sonic hedgehog signaling in the mammary gland during lactation. Each of these deficiencies was rescued by daily injections of 5-hydroxy-L-tryptophan (an immediate precursor of 5-HT) to Tph1-deficient dams. We used immortalized mouse embryonic fibroblasts to demonstrate that 5-HT induces PTHrP through a sonic hedgehog-dependent signal transduction mechanism. We also found that 5-HT altered DNA methylation of the Shh gene locus, leading to transcriptional initiation at an alternate start site and formation of a variant transcript in mouse embryonic fibroblasts in vitro and in mammary tissue in vivo. These results support a new paradigm of 5-HT-mediated Shh regulation involving DNA methylation remodeling and promoter switching. In addition to having immediate implications for lactation biology, identification and characterization of a novel functional regulatory relationship between nonneuronal 5-HT, hedgehog signaling, and PTHrP offers new avenues for the study of these important factors in development and disease.