Symptomatic and asymptomatic benign prostatic hyperplasia: molecular differentiation by using microarrays

Moringa oleifera: A Review on the Antiproliferative Potential in Breast Cancer Cells

The global burden of female breast cancer and associated deaths has become a major concern. Many chemotherapeutic agents, such as doxorubicin, have been shown to have adverse side effects. The development of multi-drug resistance is a common occurrence, contributing to chemotherapeutic failure. The resistance of breast cancer cells to drug treatment leads to a decline in the treatment efficacy and an increase in cancer recurrence. Therefore, action is required to produce alternative drug therapies, such as herbal drugs. Herbal drugs have been proven to be beneficial in treating illnesses, including cancer. This review aims to highlight the antiproliferative potential of Moringa oleifera (MO), a medicinal tree native to India and indigenous to Africa, in breast cancer cells. Although MO is not yet considered a commercial chemopreventive drug, previous studies have indicated that it could become a chemotherapeutic agent. The possible antiproliferative potential of MO aqueous leaf extract has been previously proven through its antioxidant potential as well as its ability to induce apoptosis. This review will provide an increased understanding of the effect that MO aqueous leaf extract could potentially have against breast cancer.

Effects of inflammatory prostatitis on the development and progression of benign prostatic hyperplasia: A literature review

Benign prostatic hyperplasia is a major disease that affects the quality of life of middle-aged and older men. Although >70% of men aged >70 years have pathological benign prostatic hyperplasia, its pathogenesis and progression remain unclear. In this article, we reviewed the scientific literature on this condition and examined the development of lower urinary tract symptoms. Clinically, the weight of the prostate is not always proportional to the severity of the symptoms, and many factors can influence the progression of benign prostatic hyperplasia. Other than androgens, chronic inflammation can play an essential role in its development and the induction of symptoms, especially in symptomatic hyperplasia, because inflammatory cell infiltration is frequently observed in the prostate. Inflammation-induced changes in the prostate environment lead to changes in gene expression and subsequent chronicity of inflammation. It has been suggested that chronic asymptomatic prostatitis might be associated with changes in prostate structure and subsequent symptoms. In animal studies, the administration of anti-inflammatory drugs in rats with chronic prostatitis prevented the infiltration of inflammatory cells and increased the gland-to-stroma ratio. It is hoped that future research on the molecular biology of asymptomatic prostatitis might help to develop new therapeutic strategies for lower urinary tract symptoms associated with symptomatic prostatitis. Our conclusions provide a comprehensive insight into the prevalence and development of benign prostate hyperplasia and the treatment methods that can be used to treat it.

Intrinsically Disordered Proteins: Insights from Poincaré, Waddington, and Lamarck

The past quarter-century may justly be referred to as a period analogous to the "Cambrian explosion" in the history of proteins. This period is marked by the appearance of the intrinsically disordered proteins (IDPs) on the scene since their discovery in the mid-1990s. Here, I first reflect on how we accidentally stumbled on these fascinating molecules. Next, I describe our research on the IDPs over the past decade and identify six areas as important for future research in this field. In addition, I draw on discoveries others in the field have made to present a more comprehensive essay. More specifically, I discuss the role of IDPs in two fundamental aspects of life: in phenotypic switching, and in multicellularity that marks one of the major evolutionary transitions. I highlight how serendipity, imagination, and an interdisciplinary approach embodying empirical evidence and theoretical insights from the works of Poincaré, Waddington, and Lamarck, shaped our thinking, and how this led us to propose the MRK hypothesis, a conceptual framework addressing phenotypic switching, the emergence of new traits, and adaptive evolution via nongenetic and IDP conformation-based mechanisms. Finally, I present a perspective on the evolutionary link between phenotypic switching and the origin of multicellularity.

Identification and functional activity of matrix-remodeling associated 5 (MXRA5) in benign hyperplastic prostate

Objective: Benign prostatic hyperplasia (BPH) is a common condition in aging males. The current study aims to identify differentially expressed genes (DEGs) associated with BPH and to elucidate the role of matrix-remodeling associated 5 (MXRA5) protein and mitogen-activated protein kinase (MAPK) signaling pathways in BPH.

Results: A total of 198 DEGs and a number of related pathways were identified with MXRA5 being one of the most significantly altered DEGs. MXRA5 was upregulated in BPH samples and localized mostly in stroma. Knockdown of MXRA5 induced stromal cell cycle arrest instead of inhibiting apoptosis. Consistently, MXRA5 overexpression enhanced epithelial cell proliferation. In addition, phosphorylated ERK1/2 and p38, key members of the MAPK family, were strongly decreased with knockdown but increased with overexpression.

Conclusion: Our novel data demonstrates that upregulation of MXRA5 in the enlarged prostate could contribute to the development of BPH through increasing cell proliferation via the MAPK pathway. Thus, the MXRA5-MAPK system could be rediscovered as a new therapeutic target for treating BPH.

Methods: Microarray analysis and integrated bioinformatics were conducted. The expression and biologic functions of MXRA5 was investigated via RT-PCR, western-blot, immunofluorescence, flow cytometry and MTT assay. Finally, genes involved in regulation of the MAPK pathway were investigated.

Stromal-epithelial interactions in prostate cancer: Overexpression of PAGE4 in stromal cells inhibits the invasive ability of epithelial cells

It is now widely recognized that carcinoma-associated fibroblasts which are believed to be myofibroblasts, promote the transformation of prostate epithelial cells to cancer cells, enhance their proliferation and invasiveness, and induce the acquisition of resistance to cancer therapy and immune evasiveness. Prostate-associated gene 4 (PAGE4) is an intrinsically disordered protein that is remarkably prostate-specific. PAGE4 is also a stress-response protein that functions as a transcriptional regulator and is upregulated in early-stage prostate cancer (PCa) and its precursor lesions. However, PAGE4 is downregulated in high-grade PCa and metastatic disease. Here, we show that PAGE4 is highly expressed in the stromal cells surrounding the cancer-adjacent "normal" glands and low-grade PCa lesions but not in lesions proximal to high-grade PCa. Overexpression of PAGE4 in a stromal cell line inhibits the migration and invasion of PCa epithelial cells in multiple coculture systems. PAGE4 overexpression also inhibits the downregulation of E-cadherin in PCa epithelial cells when cocultured with stromal cells. Furthermore, signaling via tumor necrosis factor-α and transforming growth factor-β pathways is decreased in the stromal cells overexpressing PAGE4 suggesting that PAGE4 appears to play a protective role against disease progression by perturbing interactions between epithelial cells and stromal cells in PCa. Taken together, these findings support previous observations that upregulation of PAGE4 in PCa correlates with a better prognosis and highlight PAGE4 as a novel therapeutic target for early-stage "low-risk" disease.

Reproductive tract biology: Of mice and men

The study of male and female reproductive tract development requires expertise in two separate disciplines, developmental biology and endocrinology. For ease of experimentation and economy, the mouse has been used extensively as a model for human development and pathogenesis, and for the most part similarities in developmental processes and hormone action provide ample justification for the relevance of mouse models for human reproductive tract development. Indeed, there are many examples describing the phenotype of human genetic disorders that have a reasonably comparable phenotype in mice, attesting to the congruence between mouse and human development. However, anatomic, developmental and endocrinologic differences exist between mice and humans that (1) must be appreciated and (2) considered with caution when extrapolating information between all animal models and humans. It is critical that the investigator be aware of both the similarities and differences in organogenesis and hormone action within male and female reproductive tracts so as to focus on those features of mouse models with clear relevance to human development/pathology. This review, written by a team with extensive expertise in the anatomy, developmental biology and endocrinology of both mouse and human urogenital tracts, focusses upon the significant human/mouse differences, and when appropriate voices a cautionary note regarding extrapolation of mouse models for understanding development of human male and female reproductive tracts.

Genomic analysis of benign prostatic hyperplasia implicates cellular re-landscaping in disease pathogenesis

Benign prostatic hyperplasia (BPH) is the most common cause of lower urinary tract symptoms in men. Current treatments target prostate physiology rather than BPH pathophysiology and are only partially effective. Here, we applied next-generation sequencing to gain new insight into BPH. By RNAseq, we uncovered transcriptional heterogeneity among BPH cases, where a 65-gene BPH stromal signature correlated with symptom severity. Stromal signaling molecules BMP5 and CXCL13 were enriched in BPH while estrogen regulated pathways were depleted. Notably, BMP5 addition to cultured prostatic myofibroblasts altered their expression profile towards a BPH profile that included the BPH stromal signature. RNAseq also suggested an altered cellular milieu in BPH, which we verified by immunohistochemistry and single-cell RNAseq. In particular, BPH tissues exhibited enrichment of myofibroblast subsets, whilst depletion of neuroendocrine cells and an estrogen receptor (ESR1)-positive fibroblast cell type residing near epithelium. By whole-exome sequencing, we uncovered somatic single-nucleotide variants (SNVs) in BPH, of uncertain pathogenic significance but indicative of clonal cell expansions. Thus, genomic characterization of BPH has identified a clinically-relevant stromal signature and new candidate disease pathways (including a likely role for BMP5 signaling), and reveals BPH to be not merely a hyperplasia, but rather a fundamental re-landscaping of cell types.

Expression, Regulation, and Function of the Calmodulin Accessory Protein PCP4/PEP-19 in Myometrium

OBJECTIVE

Calmodulin (CaM) plays a key role in the orchestration of Ca²⁺ signaling events, and its regulation is considered an important component of cellular homeostasis. The control of uterine smooth muscle function is largely dependent on the regulation of Ca²⁺ and CaM signaling. The objective of this study was to investigate the expression, function, and regulation of CaM regulatory proteins in myometrium during pregnancy.

STUDY DESIGN

Myometrium was obtained from nonpregnant women and 4 groups of pregnant women at the time their primary cesarean delivery: (i) preterm not in labor, (ii) preterm in labor with clinical and/or histological diagnosis of chorioamnionitis, (3) term not in labor; and (4) term in labor. The effect of perinatal inflammation on pcp4/pep-19 expression was evaluated in a mouse model of Ureaplasma parvum-induced chorioamnionitis. Human myometrial cells stably expressing wild-type and mutant forms of PCP4/PEP-19 were used in the evaluation of agonist-induced intracellular Ca²⁺ mobilization.

RESULTS

Compared to other CaM regulatory proteins, PCP4/PEP-19 transcripts were more abundant in human myometrium. The expression of PCP4/PEP-19 was lowest in myometrium of women with preterm pregnancy and chorioamnionitis. In the mouse uterus, pcp4/pep-19 expression was lower in late compared to mid-gestation and decreased in mice injected intra-amniotic with Ureaplasma parvum. In myometrial smooth muscle cells, tumor necrosis factor alpha and progesterone decreased and PCP4/PEP-19 promoter activity increased. Finally, the overexpression of PCP4/PEP-19 reduced agonist-induced intracellular Ca²⁺ levels in myometrial cells.

CONCLUSION

The decreased expression of PCP4/PEP-19 in myometrium contributes to a loss of quiescence in response to infection-induced inflammation at preterm pregnancy.

PAGE4 promotes prostate cancer cells survive under oxidative stress through modulating MAPK/JNK/ERK pathway

Background

Prostate cancer (PCa) is one of the most common cancers in male worldwide. Oxidative stress has been recognized as one of the driving signals pathologically linked to PCa progression. Nevertheless, the association of oxidative stress with PCa progression remains unclear.

Methods

Western blot, q-RT-PCR and bioinformatics analyses were used to examine PAGE4 expression. Comet assay and Annexin V/ PI dual staining assay were performed to investigate DNA damage and cell death under oxidative stress. Mouse xenograft model of PCa cells was established to verify the role of PAGE4 in vivo. Transcriptomic analysis was performed to investigate the underlying mechanism for the function of PAGE4 under oxidative stress. Western blot assay was conducted to determine the status of MAPK pathway. Immunohistochemistry was used to identify protein expression of PAGE4 in tumor tissues.

Results

In this study, we found that PAGE4 expression was increased in PCa cells under oxidative stress condition. PAGE4 overexpression protected PCa cells from oxidative stress-inducing cell death by reducing DNA damage. PAGE4 overexpression promoted PCa cells growth in vivo. Mechanistically, PAGE4 promoted the survival of prostate cancer cells through regulating MAPK pathway which reflected in decreasing the phosphorylation of MAP2K4, JNK and c-JUN but increasing phosphorylation of ERK1/2.

Conclusion

Our findings indicate that PAGE4 protects PCa cells from DNA damage and apoptosis under oxidative stress by modulating MAPK signalling pathway. PAGE4 expression may serve as a prognostic biomarker for clinical applications.

Electronic supplementary material

The online version of this article (10.1186/s13046-019-1032-3) contains supplementary material, which is available to authorized users.

Prostate-Associated Gene 4 (PAGE4): Leveraging the Conformational Dynamics of a Dancing Protein Cloud as a Therapeutic Target

Prostate cancer (PCa) is a leading cause of mortality and morbidity globally. While genomic alterations have been identified in PCa, in contrast to some other cancers, use of such information to personalize treatment is still in its infancy. Here, we discuss how PAGE4, a protein which appears to act both as an oncogenic factor as well as a metastasis suppressor, is a novel therapeutic target for PCa. Inhibiting PAGE4 may be a viable strategy for low-risk PCa where it is highly upregulated. Conversely, PAGE4 expression is downregulated in metastatic PCa and, therefore, reinstituting its sustained expression may be a promising option to subvert or attenuate androgen-resistant PCa. Thus, fine-tuning the levels of PAGE4 may represent a novel approach for personalized medicine in PCa.

The influence of asymptomatic inflammatory prostatitis on the onset and progression of lower urinary tract symptoms in men with histologic benign prostatic hyperplasia

Benign prostatic hyperplasia (BPH) is a condition that greatly affects the quality of life of middle-aged and elderly men. Histopathologically, hyperplastic changes frequently occur in the prostate tissue of elderly men, the incidence of which has been reported to reach approximately 80% in men in their 70s. In clinical practice, approximately 25% of men with histologic BPH are assumed to experience lower urinary tract symptoms (LUTS) and receive some kind of treatment. In other words, there are some men with histologic BPH who do not exhibit LUTS. For that reason, many factors, such as the change in hormonal environment, the immune or autoimmune response, the alteration of gene expression, and so on, are thought to affect the onset and progression of LUTS in men with histologic BPH. One such factor that has long drawn attention is the presence of asymptomatic histological inflammation, which very often accompanies symptomatic BPH. Recent studies have suggested that asymptomatic histological inflammation causes repeated destruction, healing, and regeneration of the prostate tissue, leading to the enlargement of prostatic nodules, while at the same time causing stromal tissue-predominant remodeling of the prostate tissue, which can increase urination resistance and result in the condition changing from asymptomatic BPH to symptomatic BPH. In future, the biomolecular clarification of the significance of asymptomatic histological inflammation in the prostate tissue could help develop new treatment strategies for BPH accompanied by LUTS.

Pathophysiology of benign prostate enlargement and lower urinary tract symptoms: Current concepts

Lower urinary tract symptoms (LUTS) are highly prevalent in the aging population, particularly in men. Historically, prostate enlargement was thought to be responsible for most cases of male LUTS. Several risk factors for the development of benign prostate enlargement/hyperplasia (BPE/BPH) have been identified, including age, genetics, hormones, growth factors, inflammation, and lifestyle factors. However, as our knowledge continues to evolve, male LUTS are no longer managed entirely in a prostate-centric fashion. In this article, we review current concepts in the epidemiology, etiology, and pathophysiology of BPE/BPH and male LUTS.

Cancer/Testis Antigens: "Smart" Biomarkers for Diagnosis and Prognosis of Prostate and Other Cancers

A clinical dilemma in the management of prostate cancer (PCa) is to distinguish men with aggressive disease who need definitive treatment from men who may not require immediate intervention. Accurate prediction of disease behavior is critical because radical treatment is associated with high morbidity. Here, we highlight the cancer/testis antigens (CTAs) as potential PCa biomarkers. The CTAs are a group of proteins that are typically restricted to the testis in the normal adult but are aberrantly expressed in several types of cancers. Interestingly, >90% of CTAs are predicted to belong to the realm of intrinsically disordered proteins (IDPs), which do not have unique structures and exist as highly dynamic conformational ensembles, but are known to play important roles in several biological processes. Using prostate-associated gene 4 (PAGE4) as an example of a disordered CTA, we highlight how IDP conformational dynamics may regulate phenotypic heterogeneity in PCa cells, and how it may be exploited both as a potential biomarker as well as a promising therapeutic target in PCa. We also discuss how in addition to intrinsic disorder and post-translational modifications, structural and functional variability induced in the CTAs by alternate splicing represents an important feature that might have different roles in different cancers. Although it is clear that significant additional work needs to be done in the outlined direction, this novel concept emphasizing (multi)functionality as an important trait in selecting a biomarker underscoring the theranostic potential of CTAs that is latent in their structure (or, more appropriately, the lack thereof), and casts them as next generation or “smart” biomarker candidates.

Phosphorylation-induced conformational dynamics in an intrinsically disordered protein and potential role in phenotypic heterogeneity

Intrinsically disordered proteins (IDPs) that lack a unique 3D structure and comprise a large fraction of the human proteome play important roles in numerous cellular functions. Prostate-Associated Gene 4 (PAGE4) is an IDP that acts as a potentiator of the Activator Protein-1 (AP-1) transcription factor. Homeodomain-Interacting Protein Kinase 1 (HIPK1) phosphorylates PAGE4 at S9 and T51, but only T51 is critical for its activity. Here, we identify a second kinase, CDC-Like Kinase 2 (CLK2), which acts on PAGE4 and hyperphosphorylates it at multiple S/T residues, including S9 and T51. We demonstrate that HIPK1 is expressed in both androgen-dependent and androgen-independent prostate cancer (PCa) cells, whereas CLK2 and PAGE4 are expressed only in androgen-dependent cells. Cell-based studies indicate that PAGE4 interaction with the two kinases leads to opposing functions. HIPK1-phosphorylated PAGE4 (HIPK1-PAGE4) potentiates c-Jun, whereas CLK2-phosphorylated PAGE4 (CLK2-PAGE4) attenuates c-Jun activity. Consistent with the cellular data, biophysical measurements (small-angle X-ray scattering, single-molecule fluorescence resonance energy transfer, and NMR) indicate that HIPK1-PAGE4 exhibits a relatively compact conformational ensemble that binds AP-1, whereas CLK2-PAGE4 is more expanded and resembles a random coil with diminished affinity for AP-1. Taken together, the results suggest that the phosphorylation-induced conformational dynamics of PAGE4 may play a role in modulating changes between PCa cell phenotypes. A mathematical model based on our experimental data demonstrates how differential phosphorylation of PAGE4 can lead to transitions between androgen-dependent and androgen-independent phenotypes by altering the AP-1/androgen receptor regulatory circuit in PCa cells.

Prostate-associated gene 4 (PAGE4), an intrinsically disordered cancer/testis antigen, is a novel therapeutic target for prostate cancer

Prostate-associated gene 4 (PAGE4) is a remarkably prostate-specific Cancer/Testis Antigen that is highly upregulated in the human fetal prostate and its diseased states but not in the adult normal gland. PAGE4 is an intrinsically disordered protein (IDP) that functions as a stress-response protein to suppress reactive oxygen species as well as prevent DNA damage. In addition, PAGE4 is also a transcriptional regulator that potentiates transactivation by the oncogene c-Jun. c-Jun forms the AP-1 complex by heterodimerizing with members of the Fos family and plays an important role in the development and pathology of the prostate gland, underscoring the importance of the PAGE4/c-Jun interaction. HIPK1, also a component of the stress-response pathway, phosphorylates PAGE4 at T51 which is critical for its transcriptional activity. Phosphorylation induces conformational and dynamic switching in the PAGE4 ensemble leading to a new cellular function. Finally, bioinformatics evidence suggests that the PAGE4 mRNA could be alternatively spliced resulting in four potential isoforms of the polypeptide alluding to the possibility of a range of conformational ensembles with latent functions. Considered together, the data suggest that PAGE4 may represent the first molecular link between stress and prostate cancer (PCa). Thus, pharmacologically targeting PAGE4 may be a novel opportunity for treating and managing patients with PCa, especially patients with low-risk disease.

Association of Some Polymorphisms in the VDR Gene, CYP17 Gene and SRD5A2 Gene and Prostate Cancer among Lebanese Men

Aims:

The goal of the study was to investigate possible association of some single nucleotide polymorphisms (SNPs) in the VDR gene (the FokI, BsmI, ApaI and TaqαI loci), and the CYP17 gene (the MspA1I locus), and 0 or 9 TA repeats in the SRD5A2 gene, and prostate cancer (PCa) among Lebanese men.

Materials and Methods:

Blood DNA of 69 subjects with confirmed PCa and 69 controls, all about 50 years of age or older, was subjected to PCR or PCR-restriction fragment-length polymorphism (PCR-RFLP) analyses, and the risk-bearing and the protective alleles were identified. The odds ratio (OR) of having a genotype and the relative risk (RR) of developing PCa were calculated. In addition, the distributions of homozygosis and heterozygosis in the risk-bearing alleles and the protective alleles among the control and the PCa groups were compared.

Results:

The f allele of the VDR FokI locus and the (TA) 9 repeat allele of the SRD5A2 gene were found to be associated with increased risks of PCa (p = 0.006 and 0.050, respectively). Homozygosis in the risk-bearing alleles was rare both in the control and the PCa groups. A higher fraction of the controls compared to the PCa group was double-homozygous in the two protective alleles (52.2% for controls, 24.6% for PCa group, p = <0.001).

Conclusions:

To the best of our knowledge, this is the first genetic study demonstrating the association of certain polymorphisms of the VDR gene and the SDR5A2 gene and increased risk of PCa among Lebanese men. Our study also indicates that the overall polymorphism profile of all genes involved in the prostate physiology is likely to be a better indicator for PCa risk than the polymorphisms in the individual genes.

Expression of mitochondrial genes MT-ND1, MT-ND6, MT-CYB, MT-COI, MT-ATP6, and 12S/MT-RNR1 in colorectal adenopolyps

Despite improvements in treatment strategies, colorectal cancer (CRC) still has high mortality rates. Most CRCs develop from adenopolyps via the adenoma-carcinoma sequence. A mechanism for inhibition of this sequence in individuals with a high risk of developing CRC is urgently needed. Differential studies of mitochondrial (mt) gene expressions in the progressive stages of CRC with villous architecture are warranted to reveal early risk assessments and new targets for chemoprevention of the disease. In the present study, reverse transcription-quantitative PCR (RT-qPCR) was used to determine the relative amount of the transcripts of six mt genes [MT-RNR1, MT-ND1, MT-COI, MT-ATP6, MT-ND6, and MT-CYB (region 648-15887)] which are involved in the normal metabolism of mitochondria. A total of 42 pairs of tissue samples obtained from colorectal adenopolyps, adenocarcinomas, and their corresponding adjacent normal tissues were examined. Additionally, electron transport chain (ETC), complexes I (NADH: ubiquinone oxidoreductase) and III (CoQH2-cytochrome C reductase), and carbonyl protein group contents were analyzed. Results indicate that there were differential expressions of the six mt genes and elevated carbonyl protein contents among the colorectal adenopolyps compared to their paired adjacent normal tissues (p < 0.05). The levels of complexes I and III were higher in tumor tissues relative to adjacent normal tissues. Noticeably, the expression of MT-COI was overexpressed in late colorectal carcinomas among all studied transcripts. Our data suggest that increased expressions in certain mt genes and elevated levels of ROS may potentially play a critical role in the colorectal tumors evolving from adenopolyps to malignant lesions.

Development of Quantitative Detection Assays for CYR61 as a New Marker for Benign Prostatic Hyperplasia

Among urological diseases, benign prostatic hyperplasia (BPH) exhibits a high morbidity rate, afflicting approximately 50% of men older than age 50 years. Despite intense research efforts over the past decades, the etiology and mechanisms of BPH progression are only poorly understood. Employing oligonucleotide microarrays, the authors analyzed the gene expression profiles in normal and BPH prostate samples and found that CYR61, an immediate early gene, is markedly overexpressed in BPH. To quantify cellular CYR61 mRNA expression directly, the authors developed an assay using branched-chain DNA (bDNA) technology. A human prostatic epithelial cell line, BRF-55T, derived from a BPH patient, was treated with fetal bovine serum to stimulate gene expression, and then the induction profile of the CYR61 mRNA in these serum-stimulated cells was quantitated using both bDNA and quantitative reverse transcriptase–PCR (RT-PCR). The results obtained with the 2 detection systems were found to be very similar. The bDNA assay was also found to be sensitive and highly reproducible. To the authors’knowledge, this is the first time that identifying CYR61 as a novel marker for BPH and its quantitation has been reported. These detection methods not only may be useful for diagnostic purposes but may also be used to identify suppressors of CYR61 expression for BPH therapy employing high-throughput screening assays.

Disorder, Promiscuous Interactions, and Stochasticity Regulate State Switching in the Unstable Prostate

A causal link between benign prostatic hyperplasia (BPH) and prostate cancer has long been suspected but not widely accepted. A new model is proposed that supports such a connection. In contrast to the prevailing wisdom, our model, that draws on dynamical systems theory, suggests that in response to stress, epithelial cells in the unstable gland can give rise to both types of diseases via a phenotypic switching mechanism. The central idea is that phenotypic switching is a stochastic process which exploits the plasticity of the epithelial cell. It is driven by 'noise' contributed by the conformational dynamics of proteins that are intrinsically disordered. In a system that is noisy when stressed, disorder promotes promiscuity, unmasks latent information, and rewires the network to cause phenotypic switching. Cells with newly acquired phenotypes can transcend the traditional zonal boundaries to give rise to BPH or prostate cancer depending on the microenvironment. Establishing causality between the two diseases may provide us with an opportunity to better understand their etiology and guide prevention and treatment strategies. J. Cell. Biochem. 117: 2235-2240, 2016. © 2016 Wiley Periodicals, Inc.

Molecular classification of benign prostatic hyperplasia: A gene expression profiling study in a rat model

OBJECTIVES

To characterize the molecular features of benign prostatic hyperplasia by carrying out a gene expression profiling analysis in a rat model.

METHODS

Fetal urogenital sinus isolated from 20-day-old male rat embryo was implanted into a pubertal male rat ventral prostate. The implanted urogenital sinus grew time-dependently, and the pathological findings at 3 weeks after implantation showed epithelial hyperplasia as well as stromal hyperplasia. Whole-genome oligonucleotide microarray analysis utilizing approximately 30 000 oligonucleotide probes was carried out using prostate specimens during the prostate growth process (3 weeks after implantation).

RESULTS

Microarray analyses showed 926 upregulated (>2-fold change, P < 0.01) and 3217 downregulated genes (<0.5-fold change, P < 0.01) in benign prostatic hyperplasia specimens compared with normal prostate. Gene ontology analyses of upregulated genes showed predominant genetic themes of involvement in development (162 genes, P = 2.01 × 10(-4) ), response to stimulus (163 genes, P = 7.37 × 10(-13) ) and growth (32 genes, P = 1.93 × 10(-5) ). When we used both normal prostate and non-transplanted urogenital sinuses as controls to identify benign prostatic hyperplasia-specific genes, 507 and 406 genes were upregulated and downregulated, respectively. Functional network and pathway analyses showed that genes associated with apoptosis modulation by heat shock protein 70, interleukin-1, interleukin-2 and interleukin-5 signaling pathways, KIT signaling pathway, and secretin-like G-protein-coupled receptors, class B, were relatively activated during the growth process in the benign prostatic hyperplasia specimens. In contrast, genes associated with cholesterol biosynthesis were relatively inactivated.

CONCLUSION

Our microarray analyses of the benign prostatic hyperplasia model rat might aid in clarifying the molecular mechanism of benign prostatic hyperplasia progression, and identifying molecular targets for benign prostatic hyperplasia treatment.

Effects of aging on the male reproductive system

The study aims to discuss the effects of aging on the male reproductive system. A systematic review was performed using PubMed from 1980 to 2014. Aging is a natural process comprising of irreversible changes due to a myriad of endogenous and environmental factors at the level of all organs and systems. In modern life, as more couples choose to postpone having a child due to various socioeconomic reasons, research for understanding the effects of aging on the reproductive system has gained an increased importance. Paternal aging also causes genetic and epigenetic changes in spermatozoa, which impair male reproductive functions through their adverse effects on sperm quality and count as, well as, on sexual organs and the hypothalamic-pituitary-gonadal axis. Hormone production, spermatogenesis, and testes undergo changes as a man ages. These small changes lead to decrease in both the quality and quantity of spermatozoa. The offspring of older fathers show high prevalence of genetic abnormalities, childhood cancers, and several neuropsychiatric disorders. In addition, the latest advances in assisted reproductive techniques give older men a chance to have a child even with poor semen parameters. Further studies should investigate the onset of gonadal senesce and its effects on aging men.

TP53 Codon 72 Polymorphisms and Lung Cancer Risk in the Bangladeshi Population

OBJECTIVE

To assess associations between codon 72 polymorphisms (Pro or B and Arg or b alleles) of the TP53 gene and lung cancer risk among Bangladeshis.

MATERIALS AND METHODS

The distribution of the BB, Bb, and bb genotypes and the frequencies of the B and b alleles were determined by PCR-RFLP method using DNA extracted from leucocytes of 50 confirmed lung cancer patients and 50 age-matched controls and the data were analysed.

RESULTS

The ratio of BB, Bb, and bb genotypes were in Hardy-Weinberg equilibrium except for the male patients (χ2=4.6). The B allele is overrepresented among all patients (OR=2.0, p=0.02) and the female patients (OR=4.1, p≤0.01) compared to the controls. The BB/bb ratio was also higher among the patients (OR=3.0, p=0.03). The relative risk of cancer for having BB over bb genotype was 1.8 (p=0.04) but no effect was observed for the Bb genotype. The B allele was overrepresented among patients with adenocarcinomas (OR=2.4, p≤0.01) and squamous cell carcinomas (OR=2.7, p≤0.01) over the controls but the difference was not significant for those with small cell lung carcinomas (OR=1.1, p=0.66). The B allele was overrepresented among patients age 50 or younger (OR=2.7, p≤0.01), but not for older patients (OR=1.7, p=0.07), and among smokers compared to the controls (OR=1.8-10.0, p≤0.01-0.03). However, no correlation between increasing pack-years and lung cancer was observed.

CONCLUSIONS

The Pro/Pro (BB) genotype and the B allele are risk factors for lung cancer among Bangladeshis, particularly for people under age 50, women and smokers.

Phosphorylation-induced Conformational Ensemble Switching in an Intrinsically Disordered Cancer/Testis Antigen

Prostate-associated gene 4 (PAGE4) is an intrinsically disordered cancer/testis antigen that is up-regulated in the fetal and diseased human prostate. Knocking down PAGE4 expression results in cell death, whereas its overexpression leads to a growth advantage of prostate cancer cells (Zeng, Y., He, Y., Yang, F., Mooney, S. M., Getzenberg, R. H., Orban, J., and Kulkarni, P. (2011) The cancer/testis antigen prostate-associated gene 4 (PAGE4) is a highly intrinsically disordered protein. J. Biol. Chem. 286, 13985-13994). Phosphorylation of PAGE4 at Thr-51 is critical for potentiating c-Jun transactivation, an important factor in controlling cell growth, apoptosis, and stress response. Using NMR spectroscopy, we show that the PAGE4 polypeptide chain has local and long-range conformational preferences that are perturbed by site-specific phosphorylation at Thr-51. The population of transient turn-like structures increases upon phosphorylation in an ∼20-residue acidic region centered on Thr-51. This central region therefore becomes more compact and more negatively charged, with increasing intramolecular contacts to basic sequence motifs near the N and C termini. Although flexibility is decreased in the central region of phospho-PAGE4, the polypeptide chain remains highly dynamic overall. PAGE4 utilizes a transient helical structure adjacent to the central acidic region to bind c-Jun with low affinity in vitro. The binding interaction is attenuated by phosphorylation at Thr-51, most likely because of masking the effects of the more compact phosphorylated state. Therefore, phosphorylation of PAGE4 leads to conformational shifts in the dynamic ensemble, with large functional consequences. The changes in the structural ensemble induced by posttranslational modifications are similar conceptually to the conformational switching events seen in some marginally stable ("metamorphic") folded proteins in response to mutation or environmental triggers.

Precision Medicine and Men's Health

Precision medicine can greatly benefit men's health by helping to prevent, diagnose, and treat prostate cancer, benign prostatic hyperplasia, infertility, hypogonadism, and erectile dysfunction. For example, precision medicine can facilitate the selection of men at high risk for prostate cancer for targeted prostate-specific antigen screening and chemoprevention administration, as well as assist in identifying men who are resistant to medical therapy for prostatic hyperplasia, who may instead require surgery. Precision medicine-trained clinicians can also let couples know whether their specific cause of infertility should be bypassed by sperm extraction and in vitro fertilization to prevent abnormalities in their offspring. Though precision medicine's role in the management of hypogonadism has yet to be defined, it could be used to identify biomarkers associated with individual patients' responses to treatment so that appropriate therapy can be prescribed. Last, precision medicine can improve erectile dysfunction treatment by identifying genetic polymorphisms that regulate response to medical therapies and by aiding in the selection of patients for further cardiovascular disease screening.

Widespread telomere instability in prostatic lesions

A critical function of the telomere is to disguise chromosome ends from cellular recognition as double strand breaks, thereby preventing aberrant chromosome fusion events. Such chromosome end-to-end fusions are known to initiate genomic instability via breakage-fusion-bridge cycles. Telomere dysfunction and other forms of genomic assault likely result in misregulation of genes involved in growth control, cell death, and senescence pathways, lowering the threshold to malignancy and likely drive disease progression. Shortened telomeres and anaphase bridges have been reported in a wide variety of early precursor and malignant cancer lesions including those of the prostate. These findings are being extended using methods for the analysis of telomere fusions (decisive genetic markers for telomere dysfunction) specifically within human tissue DNA. Here we report that benign prostatic hyperplasia (BPH), high-grade prostatic intraepithelial neoplasia (PIN), and prostate cancer (PCa) prostate lesions all contain similarly high frequencies of telomere fusions and anaphase bridges. Tumor-adjacent, histologically normal prostate tissue generally did not contain telomere fusions or anaphase bridges as compared to matched PCa tissues. However, we found relatively high levels of telomerase activity in this histologically normal tumor-adjacent tissue that was reduced but closely correlated with telomerase levels in corresponding PCa samples. Thus, we present evidence of high levels of telomere dysfunction in BPH, an established early precursor (PIN) and prostate cancer lesions but not generally in tumor adjacent normal tissue. Our results suggest that telomere dysfunction may be a common gateway event leading to genomic instability in prostate tumorigenesis. .

Evaluation of human papillomavirus infections in prostatic disease: a cross-sectional study in Iran

BACKGROUND

The role of inflammation in prostate diseases is suggested by the presence of inflammatory cells within the prostate in benign prostatic hyperplasia (BPH) and prostate cancer (PCa) patients. In addition, bacterial and viral infection may lead to chronic and recurrent inflammation of the prostate. The human papillomaviruses (HPVs) are a family of sexually transmitted viruses which have been implicated in the aetiology of cervical cancer and several other malignancies. This study evaluated the frequency of HPV infection in individuals with prostatic disease in Iran.

MATERIALS AND METHODS

The study included formalin fixed paraffin- embedded tissue samples of 196 primary prostate cases, including 29 PCa and 167 BPH samples. HPV DNA was purified and amplified through MY09/MY11 and GP5+/GP6+ primers with nested PCR. All patients were interviewed using a questionnaire to collect demographic information.

RESULTS

Nested PCR showed that HPV DNA was found in 17.2 percent of PCa samples and 4.8 percent of BPH samples (not significant).

CONCLUSIONS

Our data do not support a significant role of HPV infection in prostatic disease in Iranian patients, but demographic data indicated a probable association between presence of HPV DNA and risk of inflammation in prostate tissue which might lead to prostate carcinoma. Further studies are required to elucidate any roles of HPV infection in prostatic disease.

BPH and prostate cancer risk

INTRODUCTION

With the exclusion of non-melanomatous skin malignancy, prostate cancer (PCa) is the second most prevalent cancer in men globally. It has been reported that the majority of men will develop benign prostatic hyperplasia (BPH) by the time they reach their 60s. Together, these prostatic diseases have a significant morbidity and mortality affecting over a billion men throughout the world. The risk of developing prostate cancer of men suffering BPH is one that has resulted in a healthy debate amongst the urological community. Here, we try to address this conundrum with clinical and basic science evidence.

MATERIALS AND METHODS

Data from an online search and contemporary data presented at international urological congresses was reviewed.

RESULTS

BPH and PCa can be linked together at a molecular and cellular level on genetic, hormonal, and inflammatory platforms suggesting that these prostatic diseases have common pathophysiological driving factors. Epidemiological studies are weighted towards the presence of BPH having a greater risk for a man to develop PCa in his lifetime; however, a conclusion of causality cannot be confidently stated.

CONCLUSION

The future workload healthcare practitioners will face regarding BPH, and PCa will substantially increase. Further basic science and large epidemiological studies using a global cohort of men are required prior to the urological community confidently counseling their patients with BPH with regards to their PCa risk.

Cancer/testis antigen PAGE4, a regulator of c-Jun transactivation, is phosphorylated by homeodomain-interacting protein kinase 1, a component of the stress-response pathway

Prostate-associated gene 4 (PAGE4) is a cancer/testis antigen that is typically restricted to the testicular germ cells but is aberrantly expressed in cancer. Furthermore, PAGE4 is developmentally regulated with dynamic expression patterns in the developing prostate and is also a stress-response protein that is upregulated in response to cellular stress. PAGE4 interacts with c-Jun, which is activated by the stress-response kinase JNK1, and plays an important role in the development and pathology of the prostate gland. Here, we have identified homeodomain-interacting protein kinase 1 (HIPK1), also a component of the stress-response pathway, as a kinase that phosphorylates PAGE4 at T51. We show that phosphorylation of PAGE4 is critical for its transcriptional activity since mutating this T residue abolishes its ability to potentiate c-Jun transactivation. In vitro single molecule FRET indicates phosphorylation results in compaction of (still) intrinsically disordered PAGE4. Interestingly, however, while our previous observations indicated that the wild-type nonphosphorylated PAGE4 protein interacted with c-Jun [RajagopalanK. et al. (2014) Biochim, Biophys. Acta1842, 154−16324263171], here we show that phosphorylation of PAGE4 weakens its interaction with c-Jun in vitro. These data suggest that phosphorylation induces conformational changes in natively disordered PAGE4 resulting in its decreased affinity for c-Jun to promote interaction of c-Jun with another, unidentified, partner. Alternatively, phosphorylated PAGE4 may induce transcription of a novel partner, which then potentiates c-Jun transactivation. Regardless, the present results clearly implicate PAGE4 as a component of the stress-response pathway and uncover a novel link between components of this pathway and prostatic development and disease.

Personalized medicine for the management of benign prostatic hyperplasia

PURPOSE

Benign prostatic hyperplasia affects more than 50% of men by age 60 years, and is the cause of millions of dollars in health care expenditure for the treatment of lower urinary tract symptoms and urinary obstruction. Despite the widespread use of medical therapy, there is no universal therapy that treats all men with symptomatic benign prostatic hyperplasia. At least 30% of patients do not respond to medical management and a subset require surgery. Significant advances have been made in understanding the natural history and development of the prostate, such as elucidating the role of the enzyme 5α-reductase type 2, and advances in genomics and biomarker discovery offer the potential for a more targeted approach to therapy. We review the current understanding of benign prostatic hyperplasia progression as well as the key genes and signaling pathways implicated in the process such as 5α-reductase. We also explore the potential of biomarker screening and gene specific therapies as tools to risk stratify patients with benign prostatic hyperplasia and identify those with symptomatic or medically resistant forms.

MATERIALS AND METHODS

A PubMed® literature search of current and past peer reviewed literature on prostate development, lower urinary tract symptoms, benign prostatic hyperplasia pathogenesis, targeted therapy, biomarkers, epigenetics, 5α-reductase type 2 and personalized medicine was performed. An additional Google Scholar™ search was conducted to broaden the scope of the review. Relevant reviews and original research articles were examined, as were their cited references, and a synopsis of original data was generated with the goal of informing the practicing urologist of these advances and their implications.

RESULTS

Benign prostatic hyperplasia is associated with a state of hyperplasia of the stromal and epithelial compartments, with 5α-reductase type 2 and androgen signaling having key roles in the development and maintenance of the prostate. Chronic inflammation, multiple growth factor and hormonal signaling pathways, and medical comorbidities have complex roles in prostate tissue homeostasis as well as its evolution into the clinical state of benign prostatic hyperplasia. Resistance to medical therapy with finasteride may occur through silencing of the 5α-reductase type 2 gene by DNA methylation, leading to a state in which 30% of adult prostates do not express 5α-reductase type 2. Novel biomarkers such as single nucleotide polymorphisms may be used to risk stratify patients with symptomatic benign prostatic hyperplasia and identify those at risk for progression or failure of medical therapy. Several inhibitors of the androgen receptor and other signaling pathways have recently been identified which appear to attenuate benign prostatic hyperplasia progression and may offer alternative targets for medical therapy.

CONCLUSIONS

Progressive worsening of lower urinary tract symptoms and bladder outlet obstruction secondary to benign prostatic hyperplasia is the result of multiple pathways including androgen receptor signaling, proinflammatory cytokines and growth factor signals. New techniques in genomics, proteomics and epigenetics have led to the discovery of aberrant signaling pathways, novel biomarkers, DNA methylation signatures and potential gene specific targets. As personalized medicine continues to develop, the ability to risk stratify patients with symptomatic benign prostatic hyperplasia, identify those at higher risk for progression, and seek alternative therapies for those in whom conventional options are likely to fail will become the standard of targeted therapy.

Prostate-associated gene 4 (PAGE4) protects cells against stress by elevating p21 and suppressing reactive oxygen species production

BACKGROUND

It is now widely recognized that there is a strong correlation between oxidative stress and the risk of benign and malignant diseases of the prostate. Prostate-associated gene 4 (PAGE4) is a Cancer/Testis Antigen (CTA) that was previously shown to be up-regulated in prostate cancer (PCa) and symptomatic as opposed to histologic benign prostatic hyperplasia (BPH). However, its functional role in these diseases is not fully understood.

METHODS

The mRNA level of PAGE4 was detected in isolated cell types in PCa tissues that were obtained from 8 men with PCa. PAGE4 protein expression profile was analyzed in a prostate disease tissue microarray. PAGE4 was overexpressed by pCMV-PAGE4-GFP transfection and cell viability was determined using the WST-1 assay.

RESULTS

PAGE4 expression is highly dynamic; while its expression is very high in fetal prostate it is drastically decreased in the normal adult prostate but is up-regulated both in symptomatic BPH and PCa. However, in the diseased prostate, PAGE4 is highly expressed in the epithelial cells of Proliferative Inflammatory Atrophy (PIA) lesions alluding to a potential stress response function of PAGE4. Consistent with such a role, PAGE4 protein levels are up-regulated when prostate cancer (PCa) cell lines are treated with various stress factors including the proinflammatory cytokine TNFα. Interestingly, in cells challenged with stress there is increased translocation of the PAGE4 protein to the mitochondrion and production of reactive oxygen species is suppressed . Furthermore, p21 is elevated in a p53-independent manner in PAGE4-overexpressing cells which results in impeded cell cycle progression, attenuated stress-induced DNA damage, and decreased cell death.

CONCLUSIONS

PAGE4 may be contributing to the development of PCa by playing a stress-protective and anti-apoptotic role.

The Stress-response protein prostate-associated gene 4, interacts with c-Jun and potentiates its transactivation

The Cancer/Testis Antigen (CTA), Prostate-associated Gene 4 (PAGE4), is a stress-response protein that is upregulated in prostate cancer (PCa) especially in precursor lesions that result from inflammatory stress. In cells under stress, translocation of PAGE4 to mitochondria increases while production of reactive oxygen species decreases. Furthermore, PAGE4 is also upregulated in human fetal prostate, underscoring its potential role in development. However, the proteins that interact with PAGE4 and the mechanisms underlying its pleiotropic functions in prostatic development and disease remain unknown. Here, we identified c-Jun as a PAGE4 interacting partner. We show that both PAGE4 and c-Jun are overexpressed in the human fetal prostate; and in cell-based assays, PAGE4 robustly potentiates c-Jun transactivation. Single-molecule Förster resonance energy transfer experiments indicate that upon binding to c-Jun, PAGE4 undergoes conformational changes. However, no interaction is observed in presence of BSA or unilamellar vesicles containing the mitochondrial inner membrane diphosphatidylglycerol lipid marker cardiolipin. Together, our data indicate that PAGE4 specifically interacts with c-Jun and that, conformational dynamics may account for its observed pleiotropic functions. To our knowledge, this is the first report demonstrating crosstalk between a CTA and a proto-oncogene. Disrupting PAGE4/c-Jun interactions using small molecules may represent a novel therapeutic strategy for PCa.

DNA methylation alterations exhibit intraindividual stability and interindividual heterogeneity in prostate cancer metastases

Human cancers almost ubiquitously harbor epigenetic alterations. Although such alterations in epigenetic marks, including DNA methylation, are potentially heritable, they can also be dynamically altered. Given this potential for plasticity, the degree to which epigenetic changes can be subject to selection and act as drivers of neoplasia has been questioned. We carried out genome-scale analyses of DNA methylation alterations in lethal metastatic prostate cancer and created DNA methylation "cityscape" plots to visualize these complex data. We show that somatic DNA methylation alterations, despite showing marked interindividual heterogeneity among men with lethal metastatic prostate cancer, were maintained across all metastases within the same individual. The overall extent of maintenance in DNA methylation changes was comparable to that of genetic copy number alterations. Regions that were frequently hypermethylated across individuals were markedly enriched for cancer- and development/differentiation-related genes. Additionally, regions exhibiting high consistency of hypermethylation across metastases within individuals, even if variably hypermethylated across individuals, showed enrichment for cancer-related genes. Whereas some regions showed intraindividual metastatic tumor heterogeneity in promoter methylation, such methylation alterations were generally not correlated with gene expression. This was despite a general tendency for promoter methylation patterns to be strongly correlated with gene expression, particularly at regions that were variably methylated across individuals. These findings suggest that DNA methylation alterations have the potential for producing selectable driver events in carcinogenesis and disease progression and highlight the possibility of targeting such epigenome alterations for development of longitudinal markers and therapeutic strategies.

Androgen Regulation of JM-27 Is Associated With the Diseased Prostate

Despite intense research efforts, the etiology of prostatic hyperplasia associated with both benign prostatic hyperplasia (BPH) and prostate cancer remains poorly understood. Our previous studies using array technology identified JM-27 as a transcript that is dramatically up-regulated in the prostates of patients with symptomatic BPH and in normal, adjacent prostatic regions of patients with prostate cancer. In the present study, using an extended sample set, we show a correlation between the messenger RNA and protein expression of JM-27. To investigate the possible functions of this gene, its expression in the rat prostate was examined by immunoblot analysis using a polyclonal antibody specific to human JM-27. This antibody reacts with 2 rat polypeptides of 17 kd and 27 kd in size. Whereas the 27-kd form of the JM-27 protein found in human prostate is selectively expressed in the dorsolateral lobes of the rat prostate, the 17-kd form is expressed only in the ventral lobe. Expression of both forms of this protein appears to be androgen-regulated. There is a time-dependent decrease in expression of the protein products in the ventral and dorsolateral lobes of the rat prostate after castration. Administration of exogenous testosterone in castrated animals maintains protein expression in both lobes. Androgens are believed to play a central role in prostate growth and development, and therefore, it is tempting to speculate that JM-27, an androgen-regulated gene, may be involved in prostatic growth regulation. Further studies are underway to evaluate such a function for JM-27 in prostatic diseases.

Tasquinimod Is an Allosteric Modulator of HDAC4 survival signaling within the compromised cancer microenvironment

Tasquinimod is an orally active antiangiogenic drug that is currently in phase III clinical trials for the treatment of castration-resistant prostate cancer. However, the target of this drug has remained unclear. In this study, we applied diverse strategies to identify the histone deacetylase HDAC4 as a target for the antiangiogenic activity of tasquinimod. Our comprehensive analysis revealed allosteric binding (Kd 10-30 nmol/L) to the regulatory Zn(2+) binding domain of HDAC4 that locks the protein in a conformation preventing HDAC4/N-CoR/HDAC3 complex formation. This binding inhibited colocalization of N-CoR/HDAC3, thereby inhibiting deacetylation of histones and HDAC4 client transcription factors, such as HIF-1α, which are bound at promoter/enhancers where epigenetic reprogramming is required for cancer cell survival and angiogenic response. Through this mechanism, tasquinimod is effective as a monotherapeutic agent against human prostate, breast, bladder, and colon tumor xenografts, where its efficacy could be further enhanced in combination with a targeted thapsigargin prodrug (G202) that selectively kills tumor endothelial cells. Together, our findings define a mechanism of action of tasquinimod and offer a perspective on how its clinical activity might be leveraged in combination with other drugs that target the tumor microenvironment. Cancer Res; 73(4); 1386-99. ©2012 AACR.

Adaptive auto-regulation of androgen receptor provides a paradigm shifting rationale for bipolar androgen therapy (BAT) for castrate resistant human prostate cancer

Cell culture/xenograft and gene arrays of clinical material document that development of castration resistant prostate cancer (CRPC) cells involves acquisition of adaptive auto-regulation resulting in >25-fold increase in Androgen Receptor (AR) protein expression in a low androgen environment. Such adaptive AR increase paradoxically is a liability in castrated hosts, however, when supraphysiologic androgen is acutely replaced. Cell synchronization/anti-androgen response is due to AR binding to replication complexes (RC) at origin of replication sites (ORS) in early G1 associated with licensing/restricting DNA for single round of duplication during S-phase. When CRPC cells are acutely exposed to supraphysiologic androgen, adaptively increased nuclear AR is over-stabilized, preventing sufficient degradation in mitosis, inhibiting DNA re-licensing, and thus death in the subsequent cell cycle. These mechanistic results and the fact that AR/RC binding occurs in metastatic CRPCs directly from patients provides a paradigm shifting rationale for bipolar androgen therapy (BAT) in patient progressing on chronic androgen ablation. BAT involves giving sequential cycles alternating between periods of acute supraphysiologic androgen followed by acute ablation to take advantage of vulnerability produced by adaptive auto-regulation and binding of AR to RC in CRPC cells. BAT therapy is effective in xenografts and based upon positive results has entered clinical testing.

PAGE4 positivity is associated with attenuated AR signaling and predicts patient survival in hormone-naive prostate cancer

Aberrant activation of the androgen receptor (AR) plays a key role during prostate cancer (PCa) development and progression to castration-resistant prostate cancer (CR-PCa) after androgen deprivation therapy, the mainstay systemic treatment for PCa. New strategies to abrogate AR activity and biomarkers that predict aggressive tumor behavior are essential for improved therapeutic intervention. PCa tissue microarrays herein reveal that prostate-associated gene 4 (PAGE4), an X-linked cancer/testis antigen, is highly up-regulated in the epithelium of preneoplastic lesions compared with benign epithelium, but subsequently decreases with tumor progression. We show that AR signaling is attenuated in PAGE4-expressing cells both in vitro and in vivo, most likely via impaired androgen-induced AR nuclear translocation and subsequently reduced AR protein stabilization and phosphorylation at serines 81 and 213. Consistently, epithelial PAGE4 protein levels inversely correlated with AR activation status in hormone-naive and CR-PCa clinical specimens. Moreover, PAGE4 impaired the development of CR-PCa xenografts, and strong PAGE4 immunoreactivity independently predicted favorable patient survival in hormone-naive PCa. Collectively, these data suggest that dysregulation of epithelial PAGE4 modulates AR signaling, thereby promoting progression to advanced lethal PCa and highlight the potential value of PAGE4 as a prognostic and therapeutic target.

Cyr61 is regulated by cAMP-dependent protein kinase with serum levels correlating with prostate cancer aggressiveness

BACKGROUND

Cysteine-rich angiogenic inducer 61 (Cyr61) is an extracellular matrix protein involved in the transduction of growth factor and hormone signaling. Previously, we demonstrated that Cyr61 was highly expressed in prostate cancer (PCa) but that the expression levels were associated with a lower risk of PCa recurrence. In the present study, we demonstrate that serum Cyr61 is a potential biomarker that correlates with PCa aggressiveness. Furthermore, we also explore the potential mechanism underlying the changes in Cyr61 expression during PCa progression.

METHODS

Cyr61 concentrations in the medium from PCa cell lines and in serum samples obtained from PCa patients were measured by sandwich ELISA. Serum Cyr61 levels were correlated with disease characteristics and the association between Cyr61 expression changes by several types of stimulation or stress and cAMP/cAMP-dependent protein kinase (PKA) pathway were examined.

RESULTS

There was a positive correlation between Cyr61 levels in cell supernatants and mRNA expression in these cell lines. Serum Cyr61 levels were significantly higher in non-organ-confined PCa patients (116.3 ± 140.2 ng/ml) than in organ-confined PCa patients (79.7 ± 56.1 ng/ml) (P = 0.031). Cyr61 expression was up-regulated in response to both lysophosphatidic acid and androgen treatments which promoted PCa cell invasion. Serum starvation and phosphoinositide-3-kinase inhibition also resulted in Cyr61 up-regulation; however, they suppressed cell proliferation. Cyr61 up-regulation was correlated with an increase in cAMP and suppressed by PKA inhibition.

CONCLUSIONS

These findings suggest that Cyr61 expression in PCa is regulated by the cAMP/PKA pathway and that circulating Cyr61 levels are a potential serum-based biomarker for characterizing PCa.

Intriguing location of myeloperoxidase in the prostate: a preliminary immunohistochemical study

BACKGROUND

Myeloperoxidase (MPO) is a member of the peroxidase-cyclooxygenase superfamily, which is secreted from stimulated leucocytes at inflammatory sites. It is well known that MPO catalyses oxidation reactions via the release of reactive halogenating and nitrating species and thus induces tissue damage. Several studies have already implicated MPO in the development of neoplasia. Chronic or recurrent prostatic inflammation has long been recognized as having the potential to initiate and promote the development of prostate cancer. The objective was to investigate whether MPO is present in the prostate.

METHODS

Human prostate material was obtained from biopsies, transurethral resections of the prostate (TURP), prostatic adenomectomies, and retropubic radical prostatectomies. Twenty-nine slides of normal prostate tissue, benign prostatic hyperplasia (BPH), and prostate cancer were reviewed by a pathologist. Immunohistochemical analysis using MPO-specific human antibody was performed to detect MPO in the prostate tissue.

RESULTS

Immunocytohistochemistry showed cellular colocalization of MPO in the secretory epithelial cells of the prostate with staining varying from light to strong intensity. Staining in the glandular apical snouts was often reinforced although staining of basal as well as of luminal glandular cells was also present.

CONCLUSIONS

We identified, for the first time, the presence of MPO at the surface of prostatic epithelial cells. In view of the pro-oxidant properties of this enzyme, further research is needed to define whether MPO contributes to the development of prostatic lesions.

Cyr61 is a potential prognostic marker for prostate cancer

Cysteine-rich angiogenic inducer 61 (Cyr61) is an extracellular matrix protein involved in the transduction of growth factor and hormone signaling that is frequently altered in expression in several types of cancers. In prostate cancer (PCa), Cyr61 is highly expressed in organ-confined disease. Further, Cyr61 expression levels are associated with a lower risk of disease recurrence, and can be quantitatively measured in the serum. Considered together, these results indicate that Cyr61 is a potential and clinically useful tissue, as well as serum-based biomarker for differentiating lethal and non-lethal PCa.

Risk of prostate cancer associated with benign prostate disease: a primary care case-control study

BACKGROUND

Benign diseases of the prostate are common in the general male population, and prostate cancer is the most common cancer in men. Uncertainty as to the nature of the association between benign and malignant disease is a source of concern for patients and clinicians.

AIM

To determine the likelihood of men with benign prostate disease developing prostate cancer compared with men without disease.

DESIGN

Incident matched case-control study.

METHOD

All incident cases of prostate cancer (n = 984) were identified in a nationally representative community-based population, and each was matched by age with two controls with no prostate cancer (n = 1968). Participants' records of the previous 5 years were searched for diagnoses of benign prostate disease. Analyses investigated an a priori hypothesis that clinicians may record disease as benign until proven to be malignant, causing misleading significant associations between benign and malignant diagnoses.

RESULTS

There was a significant association between a diagnosis of prostate cancer and a benign diagnosis at any time in the previous 5 years: odds ratio (OR) 1.57 (95% confidence interval [CI] = 1.32 to 1.88). However, there was no significant association when benign diagnoses within 6 months and within 12 months of cancer diagnoses were excluded: OR 1.19 (95% CI = 0.97 to 1.46) and OR 1.00 (95% CI = 0.79 to 1.27) respectively.

CONCLUSION

Findings from this study suggest that unless prostate cancer is detected within 6 months, men diagnosed for the first time with benign disease are at no greater risk of prostate cancer than those with no recorded prostate disease.

Cancer/Testis Antigens as potential predictors of biochemical recurrence of prostate cancer following radical prostatectomy

Background

The Cancer/Testis Antigens (CTAs) are an important group of proteins that are typically restricted to the testis in the normal adult but are aberrantly expressed in several types of cancers. As a result of their restricted expression patterns, the CTAs could serve as unique biomarkers for cancer diagnosis/prognosis. The aim of this study was to identify promising CTAs that are associated with prostate cancer (PCa) recurrence following radical prostatectomy (RP).

Methods

The expression of 5 CTAs was measured by quantitative multiplex real-time PCR using prostate tissue samples obtained from 72 patients with apparently clinically localized PCa with a median of two years follow-up (range, 1 to 14 years).

Results

The expression of CTAs namely, CEP55, NUF2, PBK and TTK were significantly higher while PAGE4 was significantly lower in patients with recurrent disease. All CTAs with the exception of TTK were significantly correlated with the prostatectomy Gleason score, but none were correlated with age, stage, or preoperative PSA levels. In univariate proportional hazards models, CEP55 (HR = 3.59, 95% CI: 1.50-8.60), p = 0.004; NUF2 (HR = 2.28, 95% CI: 1.11-4.67), p = 0.024; and PAGE4 (HR = 0.44, 95% CI: 0.21-0.93), p = 0.031 were significantly associated with the risk of PCa recurrence. However, the results were no longer significant after adjustment for prostatectomy Gleason score.

Conclusions

To our knowledge, this is the first study to identify CTAs as biomarkers that can differentiate patients with recurrent and non-recurrent disease following RP and underscores its potential impact on PCa prognosis and treatment.

Cholesterol and benign prostate disease

The origins of benign prostatic diseases, such as benign prostatic hyperplasia (BPH) and chronic prostatitis/chronic pelvic pain syndrome (CP/CPPS), are poorly understood. Patients suffering from benign prostatic symptoms report a substantially reduced quality of life, and the relationship between benign prostate conditions and prostate cancer is uncertain. Epidemiologic data for BPH and CP/CPPS are limited, however an apparent association between BPH symptoms and cardiovascular disease (CVD) has been consistently reported. The prostate synthesizes and stores large amounts of cholesterol and prostate tissues may be particularly sensitive to perturbations in cholesterol metabolism. Hypercholesterolemia, a major risk factor for CVD, is also a risk factor for BPH. Animal model and clinical trial findings suggest that agents that inhibit cholesterol absorption from the intestine, such as the class of compounds known as polyene macrolides, can reduce prostate gland size and improve lower urinary tract symptoms (LUTS). Observational studies indicate that cholesterol-lowering drugs reduce the risk of aggressive prostate cancer, while prostate cancer cell growth and survival pathways depend in part on cholesterol-sensitive biochemical mechanisms. Here we review the evidence that cholesterol metabolism plays a role in the incidence of benign prostate disease and we highlight possible therapeutic approaches based on this concept.

Etiopathogenesis of benign prostatic hypeprlasia

Benign prostatic hyperplasia (BPH) is the most common condition affecting men older than 50 years of age. It affects about 10 percent of men under the age of 40, and increases to about 80 percent by 80 years of age. BPH is a hyperplastic process of the fibromuscular stromal and glandular epithelial elements of the prostate. Aging and the presence of the functional testes are the two established risk factors for the development of BPH. The etiopathogenesis of BPH is still largely unresolved, but multiple partially overlapping and complementary theories have been proposed, all of which seem to be operative at least to some extent. This review is focused on recent progress in this area and on the growing consensus for the important mechanisms underlying the etiology and pathogenesis of BPH.

Decreased expression of Cyr61 is associated with prostate cancer recurrence after surgical treatment

PURPOSE

Cysteine-rich angiogenic inducer 61 (Cyr61) is an extracellular matrix protein involved in the transduction of growth factor and hormone signaling. Previous studies have suggested that Cyr61 may be a marker for a more aggressive phenotype. In this study, we evaluated the association between Cyr61 staining intensity and subsequent recurrence after surgical treatment of clinically localized prostate cancer.

EXPERIMENTAL DESIGN

A study of 229 men with recurrence and 229 controls matched on age, race, pathologic stage, and Gleason sum nested in a cohort of men who underwent radical prostatectomy for clinically localized prostate cancer, utilizing immunohistochemistry analysis of tissue microarray (TMA) sections, was conducted. Odds ratios (OR) of recurrence and 95% confidence intervals (CIs) were estimated using conditional logistic regression.

RESULTS

Recurrence was identified in 12.2% of cases, and in 24.0% of controls that had at least 1 TMA spot containing cancer with a staining intensity of 3 (P = 0.001). Taking into account age, pathologic stage and grade, presurgery prostate-specific antigen concentration, and calendar of surgery as a measure of tissue block storage time, men with a Cyr61 staining intensity of 3 were 56% less likely to recur than men with a lower staining intensity (OR = 0.44, 95% CI = 0.22-0.90).

CONCLUSIONS

High Cyr61 staining intensity in adenocarcinoma was associated with a lower risk of recurrence after surgical treatment of prostate cancer independent of pathologic tumor characteristics. If validated in other sample sets, Cyr61 may serve as a tissue biomarker for stratifying men for risk of recurrence and thus could inform treatment decision making.