Brn-3a neuronal transcription factor functional expression in human prostate cancer

MethReg: estimating the regulatory potential of DNA methylation in gene transcription

Epigenome-wide association studies often detect many differentially methylated sites, and many are located in distal regulatory regions. To further prioritize these significant sites, there is a critical need to better understand the functional impact of CpG methylation. Recent studies demonstrated that CpG methylation-dependent transcriptional regulation is a widespread phenomenon. Here, we present MethReg, an R/Bioconductor package that analyzes matched DNA methylation and gene expression data, along with external transcription factor (TF) binding information, to evaluate, prioritize and annotate CpG sites with high regulatory potential. At these CpG sites, TF-target gene associations are often only present in a subset of samples with high (or low) methylation levels, so they can be missed by analyses that use all samples. Using colorectal cancer and Alzheimer's disease datasets, we show MethReg significantly enhances our understanding of the regulatory roles of DNA methylation in complex diseases.

HDAC2 Is Involved in the Regulation of BRN3A in Melanocytes and Melanoma

The neural crest transcription factor BRN3A is essential for the proliferation and survival of melanoma cells. It is frequently expressed in melanoma but not in normal melanocytes or benign nevi. The mechanisms underlying the aberrant expression of BRN3A are unknown. Here, we investigated the epigenetic regulation of BRN3A in melanocytes and melanoma cell lines treated with DNA methyltransferase (DNMT), histone acetyltransferase (HAT), and histone deacetylase (HDAC) inhibitors. DNMT and HAT inhibition did not significantly alter BRN3A expression levels, whereas panHDAC inhibition by trichostatin A led to increased expression. Treatment with the isoform-specific HDAC inhibitor mocetinostat, but not with PCI-34051, also increased BRN3A expression levels, suggesting that class I HDACs HDAC1, HDAC2, and HDAC3, and class IV HDAC11, were involved in the regulation of BRN3A expression. Transient silencing of HDACs 1, 2, 3, and 11 by siRNAs revealed that, specifically, HDAC2 inhibition was able to increase BRN3A expression. ChIP-Seq analysis uncovered that HDAC2 inhibition specifically increased H3K27ac levels at a distal enhancer region of the BRN3A gene. Altogether, our data suggest that HDAC2 is a key epigenetic regulator of BRN3A in melanocytes and melanoma cells. These results highlight the importance of epigenetic mechanisms in regulating melanoma oncogenes.

Progesterone Receptor Expression in the Benign Prostatic Hyperplasia and Prostate Cancer Tissues, Relation with Transcription, Growth Factors, Hormone Reception and Components of the AKT/mTOR Signaling Pathway

Background:

Progesterone receptor (PR) is a critical regulator in reproductive tissues that controls a variety of cellular processes. The objective of the study was to study the PR expression in patients with benign prostatic hyperplasia and prostate cancers in connection with the transcription, growth factors, AR, ERα, ERβ, and components of the AKT/mTOR signaling pathway expression.

Materials and methods:

Ninety-seven patients with prostate pathology were enrolled in the study. Forty-two patients had benign prostatic hyperplasia (BH). Fifty-five patients had locally advanced prostate cancer (PCa). The PSA level and the amount of testosterone in the serum were measured using an ELISA assay. The expression level of NF-κB p65, NF-κB p50, HIF-1, HIF-2, growth factor VEGF, VEGFR2, CAIX, as well as AR, ERα, ERβ, PR, Brn-3α, TRIM16 were quantified by RT-PCR. The protein level of Brn-3α, TRIM16 was detected by Western Blotting.

Results:

Growth in PR expression was observed in PCa tissues compared to BH ones without changes in the clinical and pathological features of the patients. An increase in PR expression was detected in patients with PCa compared to BH. Its mRNA level depended on the expression of AR, Brn-3α, and TRIM16, components of the AKT/mTOR signaling pathway, transcription, and growth factors. An increase in the TRIM16 expression in the PCa tissues was noted in the case of a low PR level. We revealed the growth in PR expression was accompanied by the suppression of the signaling cascade activity, AR, Brn-3α mRNA level, and the enhanced PTEN expression in PCa tissues. The increase in PR expression in PCa led to a decrease in the level of mRNA of NF-κB, HIF-1, VEGF, and VEGFR2.

Conclusion:

In general, the data indicated the significance of the PR expression in the development of the prostate pathology that affected the cross-talk between the steroid hormone reception and signal transduction.

Transcription factors Brn-3α and TRIM16 in cancers, association with hormone reception

Sex hormones, regulating normal physiological processes of most tissues and organs, are considered to be one of the key factors in the development of hormone-dependent cancer and formation of the hormone-resistant tumor phenotype. Recently, the importance of the system for control of hormone receptors expression mediated by nuclear peptides became evident. This system is involved in the regulation of normal physiological processes, in the pathogenesis of many diseases as well as oncogenesis. In the review, we discuss the relationships of the two regulatory peptides – Brn-3α, TRIM16 with hormone receptors. The transcription factor Brn-3α is able to affect the transcription activity of androgen and estrogen receptors. It is observed the participation of TRIM16 protein in the pathogenesis of hormone-dependent tumors due to its "anti-estrogenic effect". Additionally, they are involved in the key intracellular processes, such as proliferation, cell differentiation, and programmed death - apoptosis. Thus, Brn-3α and TRIM16 are associated with cancer development and progression. By understanding these alterations, we can identify potential markers and novel biochemical therapeutic targets. It makes clear the association between classical hormone-dependent tumors and less sensitive ones with the modification in the level of hormone receptors.

BRN4 Is a Novel Driver of Neuroendocrine Differentiation in Castration-Resistant Prostate Cancer and Is Selectively Released in Extracellular Vesicles with BRN2

PURPOSE

Neuroendocrine prostate cancer (NEPC), an aggressive variant of castration-resistant prostate cancer (CRPC), often emerges after androgen receptor-targeted therapies such as enzalutamide or de novo, via trans-differentiation process of neuroendocrine differentiation. The mechanistic basis of neuroendocrine differentiation is poorly understood, contributing to lack of effective predictive biomarkers and late disease recognition. The purpose of this study was to examine the role of novel proneural Pit-Oct-Unc-domain transcription factors (TF) in NEPC and examine their potential as noninvasive predictive biomarkers.Experimental Design: Prostate cancer patient-derived xenograft models, clinical samples, and cellular neuroendocrine differentiation models were employed to determine the expression of TFs BRN1 and BRN4. BRN4 levels were modulated in prostate cancer cell lines followed by functional assays. Furthermore, extracellular vesicles (EV) were isolated from patient samples and cell culture models, characterized by nanoparticle tracking analyses, Western blotting, and real-time PCR.

RESULTS

We identify for the first time that: (i) BRN4 is amplified and overexpressed in NEPC clinical samples and that BRN4 overexpression drives neuroendocrine differentiation via its interplay with BRN2, a TF that was previously implicated in NEPC; (ii) BRN4 and BRN2 mRNA are actively released in prostate cancer EVs upon neuroendocrine differentiation induction; and (iii) enzalutamide treatment augments release of BRN4 and BRN2 in prostate cancer EVs, promoting neuroendocrine differentiation induction.

CONCLUSIONS

Our study identifies a novel TF that drives NEPC and suggests that as adaptive mechanism to enzalutamide treatment, prostate cancer cells express and secrete BRN4 and BRN2 in EVs that drive oncogenic reprogramming of prostate cancer cells to NEPC. Importantly, EV-associated BRN4 and BRN2 are potential novel noninvasive biomarkers to predict neuroendocrine differentiation in CRPC.

Neural Transcription Factors in Disease Progression

Progression to the malignant state is fundamentally dependent on transcriptional regulation in cancer cells. Optimum abundance of cell cycle proteins, angiogenesis factors, immune evasion markers, etc. is needed for proliferation, metastasis or resistance to treatment. Therefore, dysregulation of transcription factors can compromise the normal prostate transcriptional network and contribute to malignant disease progression.The androgen receptor (AR) is considered to be a key transcription factor in prostate cancer (PCa) development and progression. Consequently, androgen pathway inhibitors (APIs) are currently the mainstay in PCa treatment, especially in castration-resistant prostate cancer (CRPC). However, emerging evidence suggests that with increased administration of potent APIs, prostate cancer can progress to a highly aggressive disease that morphologically resembles small cell carcinoma, which is referred to as neuroendocrine prostate cancer (NEPC), treatment-induced or treatment-emergent small cell prostate cancer. This chapter will review how neuronal transcription factors play a part in inducing a plastic stage in prostate cancer cells that eventually progresses to a more aggressive state such as NEPC.

EMT, stemness and tumor plasticity in aggressive variant neuroendocrine prostate cancers

Neuroendocrine/Aggressive Variant Prostate Cancers are lethal variants of the disease, with an aggressive clinical course and very short responses to conventional therapy. The age-adjusted incidence rate for this tumor sub-type has steadily increased over the past 20 years in the United States, with no reduction in the associated mortality rate. The molecular networks fueling its emergence and sustenance are still obscure; however, many factors have been associated with the onset and progression of neuroendocrine differentiation in clinically typical adenocarcinomas including loss of androgen-receptor expression and/or signaling, conventional therapy, and dysregulated cytokine function. "Tumor-plasticity" and the ability to dedifferentiate into alternate cell lineages are central to this process. Epithelial-to-mesenchymal (EMT) signaling pathways are major promoters of stem-cell properties in prostate tumor cells. In this review, we examine the contributions of EMT-induced cellular-plasticity and stem-cell signaling pathways to the progression of Neuroendocrine/Aggressive Variant Prostate Cancers in the light of potential therapeutic opportunities.

Estradiol upregulates voltage-gated sodium channel 1.7 in trigeminal ganglion contributing to hyperalgesia of inflamed TMJ

BACKGROUND

Temporomandibular disorders (TMDs) have the highest prevalence in women of reproductive age. The role of estrogen in TMDs and especially in TMDs related pain is not fully elucidated. Voltage-gated sodium channel 1.7 (Nav1.7) plays a prominent role in pain perception and Nav1.7 in trigeminal ganglion (TG) is involved in the hyperalgesia of inflamed Temporomandibular joint (TMJ). Whether estrogen could upregulate trigeminal ganglionic Nav1.7 expression to enhance hyperalgesia of inflamed TMJ remains to be explored.

METHODS

Estrous cycle and plasma levels of 17β-estradiol in female rats were evaluated with vaginal smear and enzyme linked immunosorbent assay, respectively. Female rats were ovariectomized and treated with 17β-estradiol at 0 μg, 20 μg and 80 μg, respectively, for 10 days. TMJ inflammation was induced using complete Freund's adjuvant. Head withdrawal thresholds and food intake were measured to evaluate the TMJ nociceptive responses. The expression of Nav1.7 in TG was examined using real-time PCR and western blot. The activity of Nav1.7 promoter was examined using luciferase reporter assay. The locations of estrogen receptors (ERα and ERβ), the G protein coupled estrogen receptor (GPR30), and Nav1.7 in TG were examined using immunohistofluorescence.

RESULTS

Upregulation of Nav1.7 in TG and decrease in head withdrawal threshold were observed with the highest plasma 17β-estradiol in the proestrus of female rats. Ovariectomized rats treated with 80 μg 17β-estradiol showed upregulation of Nav1.7 in TG and decrease in head withdrawal threshold as compared with that of the control or ovariectomized rats treated with 0 μg or 20 μg. Moreover, 17β-estradiol dose-dependently potentiated TMJ inflammation-induced upregulation of Nav1.7 in TG and also enhanced TMJ inflammation-induced decrease of head withdrawal threshold in ovariectomized rats. In addition, the estrogen receptor antagonist, ICI 182,780, partially blocked the 17β-estradiol effect on Nav1.7 expression and head withdrawal threshold in ovariectomized rats. ERα and ERβ, but not GPR30, were mostly co-localized with Nav1.7 in neurons in TG. In the nerve growth factor-induced and ERα-transfected PC12 cells, 17β-estradiol dose-dependently enhanced Nav1.7 promoter activity, whereas mutations of the estrogen response element at -1269/-1282 and -1214/-1227 in the promoter completely abolished its effect on the promoter activity.

CONCLUSION

Estradiol could upregulate trigeminal ganglionic Nav1.7 expression to contribute to hyperalgesia of inflamed TMJ.

Cancer cell metabolism and developmental homeodomain/POU domain transcription factors: a connecting link

The human race is afflicted with more than 100 types of cancer with diversified underlying genetic events. Still, altered metabolism (known as 'Warburg effect') and unrestrained cellular proliferation are precise traits of all cancers, being governed by the expression of genes. The obligatory energy for the proliferating neoplastic cells is endowed through the glycolytic pathway, albeit, lesser ATP is generated in this metabolic process. So, some perceptible cancer cell specific signalling is at the base of the transformed metabolism. Concurrently, the regulators of gene expression, transcription factors, have been observed to be one of the driving forces for tumourigenesis through transcriptional activation of genes involved not only in proliferation, growth and survival signalling, but also in glycolysis. This may be exemplified by the extensively studied metabolic functions of the transcriptional regulator, hypoxia inducible factor 1 (HIF1), which transactivates genes of the major enzymes of glycolysis. Preliminary investigation of a vital group of transcription factors, homeodomain transcription factors, revealed association with the process of development of an organism. The homeodomain transcription factors are, however, also found to be involved in the tumourigenesis process, with little or no information on their involvement in cancer cell metabolism. So, this is a review of the existing knowledge on homeodomain transcription factor/s for deciphering their involvement in neoplastic metabolism and it emerges that homeodomain transcription factors influence the transformed metabolic pathway in a circuitous manner.

The gep proto-oncogene Gα12 mediates LPA-stimulated activation of CREB in ovarian cancer cells

Lysophosphatidic acid (LPA) plays a critical role in the pathophysiology of ovarian cancers. Previous studies have shown that LPA stimulates the proliferation of ovarian cancer cells via Gα12. The present study utilizing Protein/DNA array analyses of LPA-stimulated HeyA8 cells in which the expression of Gα12 was silenced, demonstrates for the first time that Gα12-dependent mitogenic signaling by LPA involves the atypical activation cAMP-response element binding protein (CREB). Results indicate that the robust activation of CREB by LPA is an early event that can be monitored by the phosphorylation of SER133 of CREB as early as 3min. The findings that the expression of the constitutively activated mutant of Gα12 stimulates CREB even in the absence of LPA in multiple ovarian cancer cell lines confirm the direct role of Gα12 in the activation of CREB. This is further substantiated by the observation that the silencing of Gα12 drastically attenuates LPA-stimulated phosphorylation of CREB. Our results also establish that LPA-Gα12-dependent activation of CREB is through a cAMP-independent, but Ras-ERK-dependent mechanism. More significantly, our findings indicate that the expression of the dominant negative S133A mutant of CREB leads to a reduction in LPA-stimulated proliferation of HeyA8 ovarian cancer cells. Thus, results presented here demonstrate for the first time that CREB is a critical signaling node in LPA-LPAR and Gα12/gep proto-oncogene stimulated oncogenic signaling in ovarian cancer cells.

The neural crest transcription factor Brn3a is expressed in melanoma and required for cell cycle progression and survival

Pigment cells and neuronal cells both are derived from the neural crest. Here, we describe the Pit-Oct-Unc (POU) domain transcription factor Brn3a, normally involved in neuronal development, to be frequently expressed in melanoma, but not in melanocytes and nevi. RNAi-mediated silencing of Brn3a strongly reduced the viability of melanoma cell lines and decreased tumour growth in vivo. In melanoma cell lines, inhibition of Brn3a caused DNA double-strand breaks as evidenced by Mre11/Rad50-containing nuclear foci. Activated DNA damage signalling caused stabilization of the tumour suppressor p53, which resulted in cell cycle arrest and apoptosis. When Brn3a was ectopically expressed in primary melanocytes and fibroblasts, anchorage-independent growth was increased. In tumourigenic melanocytes and fibroblasts, Brn3a accelerated tumour growth in vivo. Furthermore, Brn3a cooperated with proliferation pathways such as oncogenic BRAF, by reducing oncogene-induced senescence in non-malignant melanocytes. Together, these results identify Brn3a as a new factor in melanoma that is essential for melanoma cell survival and that promotes melanocytic transformation and tumourigenesis.

Th17 plasticity in human autoimmune arthritis is driven by the inflammatory environment

In several murine models of autoimmune arthritis, Th17 cells are the dominant initiators of inflammation. In human arthritis the majority of IL-17-secreting cells within the joint express a cytokine phenotype intermediate between Th17 and Th1. Here we show that Th17/1 cells from the joints of children with inflammatory arthritis express high levels of both Th17 and Th1 lineage-specific transcription factors, RORC2 and T-bet. Modeling the generation of Th17/1 in vitro, we show that Th17 cells "convert" to Th17/1 under conditions that mimic the disease site, namely low TGFbeta and high IL-12 levels, whereas Th1 cells cannot convert to Th17. Th17/1 cells from the inflamed joint share T-cell receptor (TCR) clonality with Th17 cells, suggesting a shared clonal origin between Th17 and Th17/1 cells in arthritis. Using CD161, a lectin-like receptor that is a marker of human Th17, we show synovial Th17 and Th17/1 cells, and unexpectedly, a large proportion of Th1 cells express CD161. We provide evidence to support a Th17 origin for Th1 cells expressing CD161. In vitro, Th17 cells that convert to a Th1 phenotype maintain CD161 expression. In the joint CD161+ Th1 cells share features with Th17 cells, with shared TCR clonality, expression of RORC2 and CCR6 and response to IL-23, although they are IL-17 negative. We propose that the Th17 phenotype may be unstable and that Th17 cells may convert to Th17/1 and Th1 cells in human arthritis. Therefore therapies targeting the induction of Th17 cells could also attenuate Th17/1 and Th1 effector populations within the inflamed joint.

Neuronal transcription factor Brn-3a(l) is over expressed in high-grade ovarian carcinomas and tumor cells from ascites of patients with advanced-stage ovarian cancer

Objectives

In view of the recent association of Brn-3 transcription factors with neuroblastomas, cervical, breast, and prostate cancers we examined the expression of Brn-3a(l) in normal ovaries and in different histological grades of ovarian tumors. The expression of Brn-3a(l) was also evaluated in normal ovarian and cancer cell lines and tumor cells isolated from the ascites of advanced-stage ovarian cancer patients.

Methods

Normal ovaries, benign, borderline, grades 1, 2 and 3 ovarian tumors were analyzed by immunohistochemistry for Brn-3a(l) expression. A total of 46 ovarian specimens were included in the study. Immunofluorescence was used to investigate the expression of Brn-3a in normal ovarian and cancer cell lines. Brn-3a(l) expression was also evaluated by Western blot in tumor cells isolated from ascites of advanced-stage ovarian cancer patients and also in ovarian cancer cell lines.

Results

Nearly 12% of normal and benign ovarian tissues and 57% of borderline ovarian tumors were positive for epithelial Brn-3a(l) expression. Stromal staining was higher and it constituted 40% of normal non-cancerous ovaries compared to 50 and 86% in benign and borderline tumors. On the other hand, 85-100% of grades 1, 2 & 3 ovarian tumors demonstrated nuclear and cytoplasmic Brn-3a(l) staining in the epithelium. Stromal staining in grades1, 2 and 3 tumors constituted 71-88% of total staining. Overall, immunoreactive Brn-3a was present in all grades of ovarian tumors. The extent of epithelial and stromal Brn-3a staining was significantly different between the normal and histological grades of tumors (epithelial-χ² = 41.01, df = 20, P = 0.004, stromal-χ² = 24.66. df = 15, P = 0.05). The extent of epithelial staining was significantly higher in grades 1 and 2 ovarian tumors compared to normal ovaries and benign ovarian tumors (p < 0.05). In parallel, stromal staining was significantly higher in grade 3 tumors compared to normal ovaries (p < 0.05). In addition, cytoplasmic and nuclear Brn-3a expression was evident in ovarian cancer cell lines while no such expression was observed in SV40 antigen immortalized normal ovarian cell lines.

Conclusion

These data suggest that like other cancers, Brn-3a(l) expression is enhanced in ovarian tumors and its expression is consistent with its known role in inhibiting apoptosis and enhancing tumorigenesis. Specific targeting of Brn-3a may provide a useful strategy for regulating multiple tumor related genes involved with ovarian carcinomas.

A simple technique for the prediction of interacting proteins reveals a direct Brn-3a-androgen receptor interaction

The formation of multiprotein complexes constitutes a key step in determining the function of any translated gene product. Thus, the elucidation of interacting partners for a protein of interest is of fundamental importance to cell biology. Here we describe a simple methodology for the prediction of novel interactors. We have applied this to the developmental transcription factor Brn-3a to predict and verify a novel interaction between Brn-3a and the androgen receptor (AR). We demonstrate that these transcription factors form complexes within the nucleus of ND7 neuroblastoma cells, while in vitro pull-down assays show direct association. As a functional consequence of the Brn-3a-AR interaction, the factors bind cooperatively to multiple elements within the promoter of the voltage-gated sodium channel, Nav1.7, leading to a synergistic increase in its expression. Thus, these data define AR as a direct Brn-3a interactor and verify a simple interacting protein prediction methodology that is likely to be useful for many other proteins.

Neuroendocrine differentiation is involved in chemoresistance induced by EGF in prostate cancer cells

AIMS

Neuroendocrine (NE) cells were thought to be post-mitotic and non-proliferative. But it was recently reported that NE cells express, and induce surrounding cells to express potent antiapoptotic proteins. We hypothesize that neuroendocrine differentiation (NED), a common phenomenon in prostate cancer, is related to chemoresistance in prostate cancer.

MAIN METHODS

Androgen-independent human prostate cancer DU145 and PC-3 cells were exposed to epidermal growth factor (EGF). MTT assays evaluated changes in chemoresistance after EGF treatment, and flow cytometry examined EGF-induced cell cycle changes in DU145 cells. Western blotting, real-time RT-PCR and transmission electron microscopy were utilized to confirm NED.

KEY FINDINGS

After stimulation with EGF, DU145 and PC-3 cells exhibited stronger resistance to cisplatin. Flow cytometry showed that EGF stimulation substantially decreased the proportion of DU145 cells in G(1) phase. EGF treatment increased the expression of neuron-specific enolase, a marker of NED induction.

SIGNIFICANCE

NED in prostate cancer is involved in the chemoresistance induced by EGF. EGF and/or the EGF receptor may be potential targets for medical intervention in chemo-resistant prostate cancer.

A kernel-based integration of genome-wide data for clinical decision support

Background

Although microarray technology allows the investigation of the transcriptomic make-up of a tumor in one experiment, the transcriptome does not completely reflect the underlying biology due to alternative splicing, post-translational modifications, as well as the influence of pathological conditions (for example, cancer) on transcription and translation. This increases the importance of fusing more than one source of genome-wide data, such as the genome, transcriptome, proteome, and epigenome. The current increase in the amount of available omics data emphasizes the need for a methodological integration framework.

Methods

We propose a kernel-based approach for clinical decision support in which many genome-wide data sources are combined. Integration occurs within the patient domain at the level of kernel matrices before building the classifier. As supervised classification algorithm, a weighted least squares support vector machine is used. We apply this framework to two cancer cases, namely, a rectal cancer data set containing microarray and proteomics data and a prostate cancer data set containing microarray and genomics data. For both cases, multiple outcomes are predicted.

Results

For the rectal cancer outcomes, the highest leave-one-out (LOO) areas under the receiver operating characteristic curves (AUC) were obtained when combining microarray and proteomics data gathered during therapy and ranged from 0.927 to 0.987. For prostate cancer, all four outcomes had a better LOO AUC when combining microarray and genomics data, ranging from 0.786 for recurrence to 0.987 for metastasis.

Conclusions

For both cancer sites the prediction of all outcomes improved when more than one genome-wide data set was considered. This suggests that integrating multiple genome-wide data sources increases the predictive performance of clinical decision support models. This emphasizes the need for comprehensive multi-modal data. We acknowledge that, in a first phase, this will substantially increase costs; however, this is a necessary investment to ultimately obtain cost-efficient models usable in patient tailored therapy.

Human dendritic cells infected with an adenoviral vector suppress proliferation of autologous and allogeneic T cells

Dendritic cells (DCs) play a key role in the type and course of an immune response. The manipulation of human DCs to produce therapeutic agents by transduction with viral vectors is a growing area of research. We present an investigation into the effects of adenoviral vector infection on human DCs and other cell types, and on their subsequent ability to induce T-cell proliferation. We show that infection with replication-deficient adenovirus results in impaired proliferation of T cells in a mixed lymphocyte reaction (MLR). We show this to be an active suppression rather than a defect in the DCs as T cells also fail to proliferate in response to phytohaemagglutinin in the presence of adenoviral vector-infected DCs. This suppression is not attributable to phenotypic changes, death or inability of the DCs to produce cytokines on stimulation. By separation of DCs from T cells, and addition of conditioned supernatants, we show that suppression is mediated by a soluble factor. Blocking of interleukin (IL)-10 but not transforming growth factor (TGF)-beta could overcome the suppressive effect in some donors, and the source of the suppressive IL-10 was lymphocytes exposed to conditioned supernatant. Together our data suggest that infection of DCs by adenoviral vectors leads to suppression of the resulting immune response.

Neuroendocrine differentiation in prostate cancer: from lab to bedside

OBJECTIVES

To discuss the current knowledge on induction, production, sustenance and promotion of neuroendocrine differentiation in human prostate cancer.

METHODS

Review of the literature using PubMed search and scientific journal publications.

RESULTS

Morphological evidence explains some functional relationship between neuroendocrine and neoplastic surrounding cells. Transdifferentiation phenomenon and new biochemical pathways could be included in the development of androgen independence and prostate cancer progression.

CONCLUSION

Multiple evidence seems to confirm that a synergistic functional network between epithelial PSA secretory cells and neuroendocrine intraprostatic system is the main trigger for the induction and sustenance of neuroendocrine differentiation. The development of new antineoplastic molecules should consider the multiple interference of the intercellular network.

Identification and characterization of the promoter region of the Nav1.7 voltage-gated sodium channel gene (SCN9A)

The Nav1.7 sodium channel plays an important role in pain and is also upregulated in prostate cancer. To investigate the mechanisms regulating physiological and pathophysiological Nav1.7 expression we identified the core promoter of this gene (SCN9A) in the human genome. In silico genomic analysis revealed a putative SCN9A 5' non-coding exon approximately 64,000 nucleotides from the translation start site, expression of which commenced at three very closely-positioned transcription initiation sites (TISs), as determined by 5' RACE experiments. The genomic region around these TISs possesses numerous core elements of a TATA-less promoter within a well-defined CpG island. Importantly, it acted as a promoter when inserted upstream of luciferase in a fusion construct. Moreover, the activity of the promoter-luciferase construct ostensibly paralleled endogenous Nav1.7 mRNA levels in vitro, with both increased in a quantitatively and qualitatively similar manner by numerous factors (including NGF, phorbol esters, retinoic acid, and Brn-3a transcription factor over-expression).

Post-transcriptional regulation of the Brn-3b transcription factor in differentiating neuroblastoma cells

The post-transcriptional control of mRNA levels is a very powerful mechanism which allows cells to quickly change the amount of specific proteins. In this study, we wanted to analyze whether the Brn-3b transcription factor, essential for the proper development of mouse retinal ganglion cells, is subjected to such post-transcriptional regulation. In particular, due to its conservation amongst different species, we wanted to study the role of its 3' untranslated region (3'UTR). We show that the 3'UTR of the Brn-3b mRNA does indeed contain regulatory sequences that mediate mRNA degradation upon serum starvation-induced differentiation of ND7 neuroblastoma cells. The specific region mediating this effect has been characterized and two different microRNAs that potentially regulate the stability of Brn-3b have been identified. Moreover we show that Dicer, one of the key enzymes in the production of microRNAs, is strongly up-regulated in ND7 cells subjected to differentiation.