Growth Of Prostate Epithelial Cells Research Articles

Benign prostatic hyperplasia and the urinary tract repercussions

Known as the most common urological disease, benign prostatic hyperplasia (BPH) is a condition that affects men from 40 years of age. Linked to metabolic, hormonal and inflammatory mechanisms, the disease causes growth of prostatic tissue, epithelial and stromal cells, compressing the urethra, resulting in resistance to the output of urine from the bladder and the main complaints of the disease, the symptoms of the lower urinary tract (LUTS). This study aims to inform about benign prostatic hyperplasia and its main symptoms of the lower urinary tract, since these LUTS negatively affect affected patients. This is a literature review with articles published on the subject in the last 7 years, through an electronic search in the main bibliographic indexes. The benign growth of the prostate gland and its obstructive and irritating urinary symptoms such as: urgency to urinate, hesitation, forced urination with slow flow, nocturia and irritation, negatively affect the quality of life of most patients. Diagnosed in a simple way, based on the patient's clinical history, physical examination and digital rectal examination, in addition to laboratory and imaging tests, such as transrectal ultrasound, BPH has an excellent prognosis. For the treatment, the degree of the patient's symptoms is evaluated through a questionnaire, the International Prostate Symptom Score (IPSS), the classification in mild, moderate and severe defines the conduct. Watchful waiting, a treatment for patients with mild symptoms, is the most common. The existing drug classes aim to reduce LUTS and slow down the progression of the disease. The growth of the prostate gland and the consequent compression of the urethra, causes several complaints and losses in the daily life of men who have BPH, therefore, knowing the signs and symptoms of the disease is essential for it to be effectively diagnosed and treated.

Estimation levels of prostate-specific antigen, interleukin-8, oxidative stress and some inflammatory markers in sera of benign prostatic hyperplasia patients who have smoking habits as a risk factor

Benign prostatic hyperplasia (BPH) is a common multifactorial inflammatory disease of older men, defined by increased growth of prostate epithelial and stromal cells. Elevation serum levels of Interleukin-8 (IL-8), oxidative stress and inflammatory markers represent predictive surrogate markers of the disease progression in smoker BPH patients. A total of 86 BPH patients and 54 control subjects were admitted to the urology unit, Rizgary Teaching Hospital in Erbil City, Iraq between January and June 2020. Sera levels of prostate-specific antigen(PSA), IL-8, malondialdehyde (MDA), high sensitive C-reactive protein (hs-CRP), testosterone and some biomarkers concentrations were measured in the patients according to instructions of manufacturers. Patients and controls were categorized into groups according to smoking status (smokers and non-smokers). The sera levels of PSA, IL-8 and inflammatory markers like oxidative stress(MDA), hs-CRP and testosterone in every smoker subgroup (BPH patients and control) increased compared to the same non-smoker subgroups and significantly increased compared with non-smoker control (p<0.05). PSA demonstrated a significant positive correlation with the following terms, IL-8, MDA, hs-CRP, testosterone and low-density lipid (LDL)(p<0.05) and, insignificant negative correlation with high-density lipoprotein(HDL), (p>0.05). The current study demonstrated mounting evidence to support the role of smoking in the pathophysiology of BPH through elevation levels of inflammatory and oxidative stress biomarkers in sera of BPH patients.

Differential impact of paired patient-derived BPH and normal adjacent stromal cells on benign prostatic epithelial cell growth in 3D culture.

Benign prostatic hyperplasia (BPH) is an age-related disease characterized by nonmalignant abnormal growth of the prostate, which is also frequently associated with lower urinary tract symptoms. The prostate with BPH exhibits enhanced growth not only in the epithelium but also in the stroma, and stromal-epithelial interactions are thought to play an important role in BPH pathogenesis. However, our understanding of the mechanisms of stromal-epithelial interactions in the development and progression of BPH is very limited. Matched pairs of glandular BPH and normal adjacent prostate specimens were obtained from BPH patients undergoing simple prostatectomy for symptomatic BPH. Tissues were divided further into fresh specimens for culture of primary prostatic stromal cells, and specimens were embedded in paraffin for immunohistochemical analyses. Proliferation assays, immunohistochemistry, and immunoblotting were used to characterize the primary prostate stromal cells and tissue sections. Coculture of the primary stromal cells with benign human prostate epithelial cell lines BHPrE1 or BPH-1 was performed in three-dimensional (3D) Matrigel to determine the impact of primary stromal cells derived from BPH on epithelial proliferation. The effect of stromal-conditioned medium (CM) on BHPrE1 and BPH-1 cell growth was tested in 3D Matrigel as well. BPH stromal cells expressed less smooth muscle actin and calponin and increased vimentin, exhibiting a more fibroblast and myofibroblast phenotype compared with normal adjacent stromal cells both in culture and in corresponding paraffin sections. Epithelial spheroids formed in 3D cocultures with primary BPH stromal cells were larger than those formed in coculture with primary normal stromal cells. Furthermore, CM from BPH stromal cells stimulated epithelial cell growth while CM from normal primary stromal cells did not in 3D culture. These findings suggest that the stromal cells in BPH tissues are different from normal adjacent stromal cells and could promote epithelial cell proliferation, potentially contributing to the development and progression of BPH.

Promotion of epithelial hyperplasia by interleukin-8-CXCR axis in human prostate.

The clinical manifestation of benign prostatic hyperplasia (BPH) is causally linked to the inflammatory microenvironment and proliferation of epithelial and stromal cells in the prostate transitional zone. The CXC-chemokine interleukin-8 (IL-8) contributes to inflammation. We evaluated the expression of inflammatory cytokines in clinical specimens, primary cultures, and prostatic lineage cell lines. We investigated whether IL-8 via its receptor system (IL-8 axis) promotes BPH. The messenger RNA and protein expression of chemokines, including components of the IL-8 axis, were measured in normal prostate (NP; n = 7) and BPH (n = 21), urine (n = 24) specimens, primary cultures, prostatic lineage epithelial cell lines (NHPrE1, BHPrE1, BPH-1), and normal prostate cells (RWPE-1). The functional role of the IL-8 axis in prostate epithelial cell growth was evaluated by CRISPR/Cas9 gene editing. The effect of a combination with two natural compounds, oleanolic acid (OA) and ursolic acid (UA), was evaluated on the expression of the IL-8 axis and epithelial cell growth. Among the 19 inflammatory chemokines and chemokine receptors we analyzed, levels of IL-8 and its receptors (CXCR1, CXCR2), as well as, of CXCR7, a receptor for CXCL12, were 5- to 25-fold elevated in BPH tissues when compared to NP tissues (P ≤ .001). Urinary IL-8 levels were threefold to sixfold elevated in BPH patients, but not in asymptomatic males and females with lower urinary tract symptoms (P ≤ .004). The expression of the IL-8 axis components was confined to the prostate luminal epithelial cells in both normal and BPH tissues. However, these components were elevated in BPH-1 and primary explant cultures as compared to RWPE-1, NHPrE1, and BHPrE1 cells. Knockout of CXCR7 reduced IL-8, and CXCR1 expression by 4- to 10-fold and caused greater than or equal to 50% growth inhibition in BPH-1 cells. Low-dose OA + UA combination synergistically inhibited the growth of BPH-1 and BPH primary cultures. In the combination, the drug reduction indices for UA and OA were 16.4 and 7852, respectively, demonstrating that the combination was effective in inhibiting BPH-1 growth at significantly reduced doses of UA or OA alone. The IL-8 axis is a promotor of BPH pathogenesis. Low-dose OA + UA combination inhibits BPH cell growth by inducing autophagy and reducing IL-8 axis expression in BPH-epithelial cells.

The role of macrophage migration inhibitory factor in promoting benign prostatic hyperplasia epithelial cell growth by modulating COX-2 and P53 signaling.

ABSTRACTInflammation and proinflammatory cytokines have been implicated in the progression of benign prostatic hyperplasia (BPH). Macrophage migration inhibitory factor (MIF) is a proinflammatory cytokine. Our previous study found that MIF is highly expressed in BPH epithelium. It has been reported that there is a correlation between MIF and clinical BPH progression. However, whether MIF has an effect on BPH epithelial cells is not clear. The aim of this study was to explore whether MIF has a role in BPH. Our results showed that immunohistochemistry (IHC) showed that MIF is highly expressed in the epithelium and that MIF and PCNA expression levels are higher in BPH samples than in control. CCK8 and flow cytometry assays showed that recombinant human MIF (rMIF) promoted the proliferation of BPH-1 and PWR-1E cells, while ISO-1 partially reversed this effect on proliferation. JC-1 assays showed that rMIF inhibited the apoptosis of BPH-1 and PWR-1E cells, and ISO-1 could partially reverse this inhibition. Moreover, western blotting indicated that rMIF downregulated P53 and upregulated COX-2. Furthermore, MIF-induced proliferation could be inhibited by celecoxib in the CCK8 and flow cytometry assay. MIF-inhibited apoptosis could be partially reversed by celecoxib in the JC-1 assay. Western blotting showed that celecoxib could partially reverse MIF-induced COX-2 upregulation and P53 downregulation. Together, MIF is highly expressed in BPH epithelium. In vitro, MIF promoted BPH epithelial cell growth by regulating COX-2 and P53 signaling. Targeting MIF may provide a new option for the improved treatment of BPH in the future.

Changes in receptor location affect the ability of oxytocin to stimulate proliferative growth in prostate epithelial cells.

In normal prostate cells, cell membrane receptors are located within signalling microdomains called caveolae. During cancer progression, caveolae are lost and sequestered receptors move out onto lipid rafts. The aim of this study was to investigate whether a change in the localisation of receptors out of caveolae and onto the cell membrane increased cell proliferation invitro, and to determine whether this is related to changes in the cell signalling pathways. Normal human prostate epithelial cells (PrEC) and androgen-independent (PC3) cancer cells were cultured with 10nM dihydrotestosterone (DHT). The effects of oxytocin (OT) and gonadal steroids on proliferation were assessed using the MTS assay. Androgen receptor (AR) and oxytocin receptor (OTR) expression was identified by immunofluorescence and quantified by western blot. OTR and lipid raft staining was determined using Pearson's correlation coefficient. Protein-protein interactions were detected and the cell signalling pathways identified. Treatment with OT did not affect the proliferation of PrEC. In PC3 cells, OT or androgen alone increased cell proliferation, but together had no effect. In normal cells, OTR localised to the membrane and AR localised to the nucleus, whereas in malignant cells both OTR and AR were identified in the cell membrane. Colocalisation of OTR and AR increased following treatment with androgens. Significantly fewer OTR/AR protein-protein interactions were seen in PrEC. With OT treatment, several cell signalling pathways were activated. Movement of OTR out of caveolae onto lipid rafts is accompanied by activation of alternative signal transduction pathways involved in stimulating increased cell proliferation.

Loss of Par3 promotes prostatic tumorigenesis by enhancing cell growth and changing cell division modes.

Although cell polarity plays an important role in epithelial tumorigenesis, the consequence of polarity protein loss in prostatic tumorigenesis and the underlying mechanisms remain unclear. Using conditional knockout mouse models, we found in the current study that loss of polarity protein Par3 increases prostatic epithelial cell growth, elevates symmetrical cell divisions in basal cells, and randomizes spindle orientation in luminal cells, causing the development of high-grade prostatic intraepithelial neoplasia (PIN). Mechanistically, loss of Par3 dissociates the Par3/merlin/Lats1 complex, consequently inhibiting phosphorylation of Lats1 to attenuate the Hippo pathway. Furthermore, attenuated Hippo pathway enhances nuclear translocation of Yes-associated protein (YAP), which promotes cell proliferation and symmetrical cell divisions through transcriptional activation of Ki-67 and Sox2. In addition, Lats1 dephosphorylation impairs its interaction with G protein signaling modulator 2 (GPSM2, which is also known as LGN) that causes randomization of spindle orientation in luminal cells. Interestingly, co-deletion of Par3 and Lats1 for complete blockade of the Hippo pathway in mice results in prostate tumor initiation, whereas co-deletion of Par3 and YAP for disrupting YAP nuclear translocation reverses the phenotypes to a relatively normal state. Therefore, our findings highlight combination of Par3 loss and blockade of the Hippo pathway as a novel mechanism for prostatic tumorigenesis.

Epigallocatechin-3-gallate reduces the proliferation of benign prostatic hyperplasia cells via regulation of focal adhesions

AimsBenign prostatic hyperplasia (BPH) is the most common urological disease that is characterized by the excessive growth of prostatic epithelial and stromal cells. Pharmacological therapy for BPH has limited use due to the many side effects so there is a need for new agents including natural compounds such as epigallocatechin-3-gallate (EGCG). This study was undertaken to assess the role of EGCG, suppressing the formation of BPH by reducing inflammation and oxidative stress, in cytoskeleton organization and ECM interactions via focal adhesions. Main methodsWe performed MTT assay to investigate cell viability of BPH-1 cells, wound healing assay to examine cell migration, immunofluorescence assay for F-actin organization and paxillin distribution and finally immunoblotting to investigate focal adhesion protein levels in the presence and absence of EGCG. Key findingsWe found that EGCG inhibits cell proliferation at the concentration of 89.12μM, 21.2μM and 2.39μM for 24, 48 and 72h, respectively as well as inhibitory effects of EGCG on BPH-1 cell migration were observed in a wound healing assay. Furthermore, it was determined by immunofluorescence labeling that EGCG disrupts F-actin organization and reduces paxillin distribution. Additionally, EGCG decreases the activation of FAK (Focal Adhesion Kinase) and the levels of paxillin, RhoA (Ras homolog gene family, member A), Cdc42 (cell division cycle 42) and PAK1 (p21 protein-activated kinase 1) in a dose-dependent manner. SignificanceFor the first time, by this study, we found evidence that BPH-1 cell proliferation could be inhibited with EGCG through the disruption of cytoskeleton organization and ECM interactions. Consequently, EGCG might be useful in the prevention and treatment of diseases characterized by excessive cell proliferation such as BPH.

Abstract LB-167: A novel metabolite of citrus tangeretin epigenetically inhibits the growth of human prostate cancer cells

Abstract Prostate cancer is the second leading cause of cancer death in men in the United States. Polymethoxyflavonoids (PMFs) such as tangeretin which exclusively exist in citrus fruit peels have been studied to have many bioactivities. In this study, we investigated the inhibitory effect of the metabolites of tangeretin in human prostate cancer LNCaP and PC3 cells. The results showed that PMF1 is a synthetic tangereitin metabolite can significantly inhibits the growth of LNCaP and PC-3 cells (IC50 14.0 and 13.5 µM, respectively) while PMF1 at 15 µM cannot affect the growth of human normal prostate epithelial RWPE-1 cells. The results of the anchorage-independent growth analysis indicated that PMF1 can suppress the colony formation in LNCaP and PC-3 cells as well as LNCaP and PC-3 stem-like cells which were isolated when the parent cells were cultured in the serum-free medium on the ultra-low attached dishes. Furthermore, PMF1 can induce apoptosis in LNCaP cells in which PMF1 increases protein expressions of Bax and Bad and decreases protein expressions of procaspases-3 and Bcl-2. We also found that PMF1 also decreases the protein levels of DNA Methyltransferase 1 and histone deacetylases 1, 2, and 4/5/9. These results suggested that PMF1 might effectively inhibit the growth of human prostate cancer cells as well as prostate cancer stem cells, which provides new insights in the prevention and treatment of prostate cancer. Citation Format: Yen-Hsiang Chao, Zheng-Yuan Su. A novel metabolite of citrus tangeretin epigenetically inhibits the growth of human prostate cancer cells [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr LB-167. doi:10.1158/1538-7445.AM2017-LB-167

ETS (E26 transformation-specific) up-regulation of the transcriptional co-activator TAZ promotes cell migration and metastasis in prostate cancer

Prostate cancer is a very common malignant disease and a leading cause of death for men in the Western world. Tumorigenesis and progression of prostate cancer involves multiple signaling pathways, including the Hippo pathway. Yes-associated protein (YAP) is the downstream transcriptional co-activator of the Hippo pathway, is overexpressed in prostate cancer, and plays a vital role in the tumorigenesis and progression of prostate cancer. However, the role of the YAP paralog and another downstream effector of the Hippo pathway, transcriptional co-activator with PDZ-binding motif (TAZ), in prostate cancer has not been fully elucidated. Here, we show that TAZ is a basal cell marker for the prostate epithelium. We found that overexpression of TAZ promotes the epithelial-mesenchymal transition (EMT), cell migration, and anchorage-independent growth in the RWPE1 prostate epithelial cells. Of note, knock down of TAZ in the DU145 prostate cancer cells inhibited cell migration and metastasis. We also found that SH3 domain binding protein 1 (SH3BP1), a RhoGAP protein that drives cell motility, is a direct target gene of TAZ in the prostate cancer cells, mediating TAZ function in enhancing cell migration. Moreover, the prostate cancer-related oncogenic E26 transformation-specific (ETS) transcription factors, ETV1, ETV4, and ETV5, were required for TAZ gene transcription in PC3 prostate cancer cells. MAPK inhibitor U0126 treatment decreased TAZ expression in RWPE1 cells, and ETV4 overexpression rescued TAZ expression in RWPE1 cells with U0126 treatment. Our results show a regulatory mechanism of TAZ transcription and suggest a significant role for TAZ in the progression of prostate cancer.

Mitochondrion-associated protein peroxiredoxin 3 promotes benign prostatic hyperplasia through autophagy suppression and pyroptosis activation.

Benign prostatic hyperplasia (BPH) is one of the most common diseases in the senior men and age plays an important role in the initiation and development of BPH. Mammalian cells primarily use the autophagy-lysosome system to degrade misfolded/aggregated proteins and dysfunctional organelles such as mitochondria and suppress pyroptosis, a type of cell death that stimulates inflammatory responses and growth of other cells around. Peroxiredoxin 3 (PRDX3) is the only mitochondrion-associated member of peroxiredoxin family enzymes that exert their protective antioxidant role in cells through their peroxidase activity. We hypothesized that PRDX3 may inhibit autophagy to activate pyroptosis to induce growth of prostatic epithelial cells. Here we show that PRDX3 maintained the integrity of mitochondria and its depletion led to an enhancement of oxidative stresses. PRDX3-associated and PRDX3-free mitochondria co-existed in the same cells. PRDX3 expressed at higher levels in prostatic epithelial cells in prostate tissues from BPH patients and BPH-representative cell line than in prostate tissues from healthy donors and a cell line representing normal epithelial cells. PRDX3 suppressed autophagy flux and activated pyroptosis to induce inflammatory responses and stimulate the over-growth of prostate tissues. Therefore, higher levels of PDRX3 in prostatic epithelial cells may promote the initiation and development of BPH through autophagy inhibition and pyroptosis activation.

Crosstalk between the Androgen Receptor and PPAR Gamma Signaling Pathways in the Prostate.

Nuclear receptors are a superfamily of ligand-activated transcription factors that play critical roles in the regulation of normal biological processes and several disease states. Of the nuclear receptors expressed within the prostate, the androgen receptor (AR) promotes the differentiation of prostatic epithelial cells and stimulates production of enzymes needed for liquefaction of semen. Multiple forms of AR also promote the growth of both early and late stage prostate cancers. As a result, drugs that target the AR signaling pathway are routinely used to treat patients with advanced forms of prostate cancer. Data also suggest that a second member of the nuclear receptor superfamily, the peroxisome proliferator activated receptor gamma (PPARγ), is a tumor suppressor that regulates growth of normal prostate and prostate cancers. Recent studies indicate there is a bidirectional interaction between AR and PPARγ, with each receptor influencing the expression and/or activity of the other within prostatic tissues. In this review, we examine how AR and PPARγ each regulate the growth and development of normal prostatic epithelial cells and prostate cancers. We also discuss interactions between the AR and PPARγ signaling pathways and how those interactions may influence prostate biology.

Molecular mechanisms underlying resistance to androgen deprivation therapy in prostate cancer.

Prostate cancer (PCa) is the most widely diagnosed male cancer in the Western World and while low- and intermediate-risk PCa patients have a variety of treatment options, metastatic patients are limited to androgen deprivation therapy (ADT). This treatment paradigm has been in place for 75 years due to the unique role of androgens in promoting growth of prostatic epithelial cells via the transcription factor androgen receptor (AR) and downstream signaling pathways. Within 2 to 3 years of ADT, disease recurs—at which time, patients are considered to have castration-recurrent PCa (CR-PCa). A universal mechanism by which PCa becomes resistant to ADT has yet to be discovered. In this review article, we discuss underlying molecular mechanisms by which PCa evades ADT. Several major resistance pathways center on androgen signaling, including intratumoral and adrenal androgen production, AR-overexpression and amplification, expression of AR mutants, and constitutively-active AR splice variants. Other ADT resistance mechanisms, including activation of glucocorticoid receptor and impairment of DNA repair pathways are also discussed. New therapies have been approved for treatment of CR-PCa, but increase median survival by only 2-8 months. We discuss possible mechanisms of resistance to these new ADT agents. Finally, the practicality of the application of “precision oncology” to this continuing challenge of therapy resistance in metastatic or CR-PCa is examined. Empirical validation and clinical-based evidence are definitely needed to prove the superiority of “precision” treatment in providing a more targeted approach and curative therapies over the existing practices that are based on biological “cause-and-effect” relationship.

Abstract 932: AR signaling differentially regulates the growth of prostate epithelial cells

Abstract The prostate is an androgen-dependent organ. Androgen stimulates the growth of normal prostatic cells, as well as prostate cancer (PCa). However, AR signaling does not always promote cell proliferation, in some cases, it may even inhibit the growth of prostatic cells. In this study, we used NHPrE, a cell line derived from normal human prostate epithelia, to study how AR signaling modulates the growth of prostatic cells and to explore the mechanisms involved in AR's differential function in vitro and in vivo. Our results showed that inducing AR signaling in NHPrE cells suppressed their growth in vitro, concomitant with a reduction of Myc. In contrast, ectopic expression of AR in NHPrE cells induced the expression of Myc and pSTAT3 and drove the development of invasive PCa in vivo, suggesting a distinct in vivo function of AR signaling in prostatic cells. Furthermore, our data showed that the presence of prostate stromal cells over-rode androgen-mediated growth inhibition on NHPrE/AR cells in vitro; and IL-6/pSTAT3 was implicated in this stromal/epithelial communication. In conclusion, our study showed that AR signaling differentially regulated the growth of prostatic cells in vitro and in vivo through a mechanism that involved stromal/epithelial interactions. Citation Format: Xiuping Yu, Shu Yang. AR signaling differentially regulates the growth of prostate epithelial cells. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 932.

Abstract LB-268: Androgen signaling in cancer-associated fibroblasts contributes to progression of prostate cancer

Abstract Interactions between epithelial and stromal cells are important in the development of prostate cancer (PCa). Cancer-associated fibroblasts (CAFs) have been to support tumor progression, metastasis, and differentiation. Androgen receptor (AR) and related pathways are known to support the growth and survival of prostate epithelial cancer cells, the roles of AR-dependent processes in cancerous stroma are less clear. We sought to investigate if AR-dependent pathways present in CAF cells influence the growth and tumorogencity of epithelial cancer cells in relation to androgen-deprivation therapy in prostate cancer. Murine CAFs were isolated from a well-described PTEN-dependent cancer mouse model. A co-culture system was developed based on multiple lines of murine CAFs grown along with human prostate cancer epithelial cells, and a murine-specific anti-sense oligonucleotide (ASO) against murine AR was used to specifically suppress AR expression in murine CAFs in this system. Using this co-culture system, we found that murine CAFs promoted cell proliferation and colony formation in several human prostate cancer cell lines. Further, these processes were decreased by suppression of AR-expression in CAFs. Expression of genes related to tumorogenicity in epithelial cells were investigated by real-time quantitative PCR. Markers associated with epithelial-mesenchymal transition (EMT) and stemness were increased in human prostate cancer cells grown with low-AR CAFs. Our data indicates that suppression of AR in CAFs results in down-regulation in the growth and tumorogenecity of prostate cancer cells through pathways related to EMT and “cell reprograming”. As such, development of therapies which inhibit the tumor-promoting pathways present in stromal cells may be one approach to improve the treatment of prostate cancer. Citation Format: Chun-Peng Liao, Leng-Ying Chen, Andrea Luethy, Youngsoo Kim, Robert MacLeod, Mitchell Gross. Androgen signaling in cancer-associated fibroblasts contributes to progression of prostate cancer. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr LB-268.

Increased expression and activity of p75NTR are crucial events in azacitidine-induced cell death in prostate cancer.

The high affinity nerve growth factor (NGF) NGF receptor, p75NTR, is a member of the tumor necrosis factor (TNF) receptor superfamily that shares a conserved intracellular death domain capable of inducing apoptosis and suppressing growth in prostate epithelial cells. Expression of this receptor is lost as prostate cancer progresses and is minimal in established prostate cancer cell lines. We aimed to verify the role of p75NTR in the azacitidine-mediated antitumor effects on 22Rv1 and PC3 androgen-independent prostate cancer cells. In the present study, we reported that the antiproliferative and pro-apoptotic effects of 5-azacytidine (azacitidine) were more marked in the presence of physiological concentrations of NGF and were reduced when a blocking p75NTR antibody or the selective p75NTR inhibitor, Ro 08-2750, were used. Azacitidine increased the expression of p75NTR without interfering with the expression of the low affinity NGF receptor TrkA and induced caspase9-dependent caspase3 activity. Taken together, our results suggest that the NGF network could be a candidate for future pharmacological manipulation in aggressive prostate cancer.

Disminución de la toxicidad y del efecto terapéutico del ácido zoledrónico en el tratamiento combinado con diferentes extractos antioxidantes

BackgroundZoledronic acid is used in the treatment of cancer-related diseases, although its use has been associated with avascular osteonecrosis. AimsTo determine the possible protective effect of a range of antioxidant substances against the inhibition of human prostate epithelial cell growth (PNT2) and transgenic adenocarcinoma mouse prostate tumour cells (TRAMP-C1), in treatments combining zoledronic acid and ionising radiation (IR). Material and methodCell survival is studied via cell viability assays (MTT) for 2 cell lines in isolated and combined treatments with zoledronic acid and/or IR, as well as the effect of adding 3 antioxidant substances. ResultsZoledronic acid displays a significant cytotoxic effect over PNT2 and TRAMP-C1 cells (P<.001). The administration of antioxidants together with the zoledronic acid shows a protective effect for normal prostate cells, yet not so for prostate tumour cells. However, the administration of rosmarinic acid and apigenin in treatments combined with zoledronic acid provides a protective effect from the harmful effects of applying ionizing radiation, not only for normal PNT2 cells, but also for tumour cells. ConclusionThe use of antioxidant substances decreases the cytotoxic effect of zoledronic acid over non-tumour cells, and as such could be used in benign diseases. Furthermore, in the combined treatment using ionising radiation, these antioxidants also produced a protective effect in tumour cells, thus reducing the therapeutic effect sought by combining the treatment with radiation.

Effect of prostate peripheral zones stromal cells on the proliferation of prostate cells by overexpression of LMO2 gene

To explore the biological effect of prostate peripheral zones (PZs) stromal cells on the proliferation of prostate cells by overexpression of LMO2 gene. Genes expressional distinction of different prostate stromal cells was screened by gene expression arrays. To validate the microarray data, real time-polymerase chain reaction (RT-PCR), Western blotting analysis were used to check the over expression of LMO2 in PZs cells.To compare the effect of stromal cells which overexpressed LMO2 gene on in vitro proliferation ability of BPH-1 and PC3 cell lines, cell proliferation was measured by CCK-8 and EdU assay. Cytokines chip was used to screen expression of cytokines in WPMY-1-LMO2 conditioned medium. The changes of BPH-1 and PC3 proliferation associated proteins were assessed by Western blotting. A total of 512 genes were identified as markedly differentially expressed in stromal cells originated from different zones. Among these genes, LMO2 gene was overexpression in peripheral zones stromal cells, and confirmed by RT-PCR and Western blotting. Expression level of LMO2 gene was significantly up-regulated in peripheral zones stromal cells compared with transitional zones stromal cells, increased by 3.36 folds on average (P<0.01). The proliferation of both PC3 and BPH-1 were found increased and STAT3 phosphorylation and CCND1 expression were increased after cultured in conditioned medium from stromal cells which stably expressed LMO2. Cytokines chip found increased FGF-9 and IL-11 expression in the medium supernatant reserved from LMO2-overexpressed stromal cell line. Distinct gene expression exists among prostate stromal cells originated from different zones. LMO2 overexpressed stromal cells can induce prostate epithelial cell growth via paracrine of FGF-9, IL-11 or other cytokines.

Effect of androgen signaling in stromal cells on growth of prostate cancer.

297 Background: Interactions between epithelial and stroma cells are important in the development of prostate cancer (PCa). Cancer-associated fibroblasts (CAFs) have been to support tumor progression, metastasis, and differentiation. Androgen receptor (AR) and related pathways are known to support the growth and survival of prostate epithelial cancer cells, the roles of AR-dependent processes in cancerous stroma are less clear. We sought to investigate if AR-dependent pathways present in CAF cells influence the growth and tumorogencity of epithelial cancer cells in relation to androgen-deprivation therapy in prostate cancer. Methods: Murine CAFs were isolated from a well-described PTEN-dependent cancer mouse model (Liao, et al Cancer Res, 2010. 70(18):7294). A co-culture system was developed based on multiple lines of murine CAFs grown along with human prostate cancer epithelial cells, and a murine-specific anti-sense oligonucleotide (ASO) against murine AR was used to specifically suppress AR expression in murine CAFs in this system. RT-PCR was used to investigate changes in gene expression. Results: Using this co-culture system, we found that murine CAFs promoted cell proliferation and colony formation in several human prostate cancer cell lines. Further, these processes were decreased by suppression of AR-expression in CAFs. Expression of genes related to tumorigenicity in epithelial cells were investigated. Markers associated with epithelial-mesenchymal transition (EMT, N-Cad) and “stemness” (OCT4, Sox2, Nanog) were increased in human prostate cancer cells grown with low-AR CAFs. Conclusions: Our data indicates that suppression of AR in CAFs results in down-regulation in the growth and tumorigenicity of prostate cancer cells through pathways related to EMT and “cell reprograming”. As such, development of therapies which inhibit the tumor-promoting pathways present in stromal cells may be one approach to improve the treatment of prostate cancer.

Differential Roles of Carboxylated and Uncarboxylated Osteocalcin in Prostate Cancer Growth.

Serum levels of osteocalcin (OC), a bone matrix non-collagenous protein secreted by osteoblasts, are correlated with pathological bone remodeling such as the bone metastasis of cancer, as well as physiological bone turnover. The pathological roles in prostate cancer growth of the two existing types of serum OC, γ-carboxylated (GlaOC) and lower- (or un-) carboxylated (GluOC), have not yet been discriminatively examined. In the present study, we demonstrate that normal prostate epithelial cell growth was promoted by both types of OC, while growth of cancer cells in the prostate was accelerated by GlaOC but suppressed by GluOC. We suggest that OC regulates prostate cancer growth depending on the γ-carboxylation, in part by triggering reduced phosphorylation of receptor tyrosine kinases.