Tissues Of Prostate Cancer Patients Research Articles

Identification of tumor suppressive role of microRNA-132 and its target gene in tumorigenesis of prostate cancer.

Previous literature exists on the role of microRNA (miR)-132 in initiation and progression of various malignancies. In this study, we aimed at understanding the relationship of miR-132 of prostate tumorigenesis. We collected 32prostate cancer tissues and adjacent non-cancerous controls, and detected the expression level of miR-132. Then the miRNA database was searched online and luciferase assay perform to understand the regulatory relationship between miR-132 and E2F5. Moreover, we also conducted real-time PCR and western blot analysis to study the mRNA and protein expression level of E2F5 among different groups(cancerous tissue,n=32; non-cancerous tissue,n=32) or cells treated with scramble control, miR-132mimics, E2F5siRNA and miR-132 inhibitors. miR-132 was upregulated in cancerous tissues of prostate cancer patients. E2F5 was the target of miR-132, and negative regulatory relationship between miR-132 andE2F5 was also confirmed by luciferase assay. The mRNA and protein expression level of E2F5 increased in cancerous tissue group. miR-132 decreased the expression of E2F5 in prostate cancer cells, and introduction of miR-132 reduced the viability and E2F5 and promoted the viability of prostate cancer cells. miR-132 inhibited apoptosis and E2F5 accelerated apoptosis. In conclusion, miR-132 was upregulated in cancerous tissue of prostate cancer. E2F5 was a direct target of miR-132, and downregulation of E2F5 caused by upregulation of miR-132 may contribute to the tumorigenesis of prostate cancer.

Epithelial-Mesenchymal Transition (EMT) and Prostate Cancer.

Typically the normal epithelial cells are a single layer, held tightly by adherent proteins that prevent the mobilization of the cells from the monolayer sheet. During prostate cancer progression, the epithelial cells can undergo epithelial-mesenchymal transition or EMT, characterized by morphological changes in their phenotype from cuboidal to spindle-shaped. This is associated with biochemical changes in which epithelial cell markers such as E-cadherin and occludins are down-regulated, which leads to loss of cell-cell adhesion, while mesenchymal markers such as vimentin and N-cadherin are up-regulated, thereby allowing the cells to migrate or metastasize to different organs. The EMT transition can be regulated directly and indirectly by multiple molecular mechanisms including growth factors and cytokines such as transforming growth factor-beta (TGF-β), epidermal growth factor (EGF) and insulin-like growth factor (IGF), and signaling pathways such as mitogen-activated protein kinase (MAPK) and Phosphatidylinositol 3-Kinase (PI3K). This signaling subsequently induces expression of various transcription factors like Snail, Twist, Zeb1/2, that are also known as master regulators of EMT. Various markers associated with EMT have been reported in prostate cancer patient tissue as well as a possible association with health disparities. There has been consideration to therapeutically target EMT in prostate cancer patients by targeting the EMT signaling pathways.

Biomarkers identified for prostate cancer patients through genome-scale screening

Prostate cancer is a threat to men and usually occurs in aged males. Though prostate specific antigen level and Gleason score are utilized for evaluation of the prostate cancer in clinic, the biomarkers for this malignancy have not been widely recognized. Furthermore, the outcome varies across individuals receiving comparable treatment regimens and the underlying mechanism is still unclear. We supposed that genetic feature may be responsible for, at least in part, this process and conducted a two-cohort study to compare the genetic difference in tumorous and normal tissues of prostate cancer patients. The Gene Expression Omnibus dataset were used and a total of 41 genes were found significantly differently expressed in tumor tissues as compared with normal prostate tissues. Four genes (SPOCK3, SPON1, PTN and TGFB3) were selected for further evaluation after Gene Ontology analysis, Kyoto Encyclopedia of Genes and Genomes pathway analysis and clinical association analysis. MIR1908 was also found decreased expression level in prostate cancer whose target genes were found expressing in both prostate tumor and normal tissues. These results indicated that these potential biomarkers deserve attention in prostate cancer patients and the underlying mechanism should be further investigated.

Novel RNA biomarkers of prostate cancer revealed by RNA-seq analysis of formalin-fixed samples obtained from Russian patients.

Due to heterogeneous multifocal nature of prostate cancer (PCa), there is currently a lack of biomarkers that stably distinguish it from benign prostatic hyperplasia (BPH), predict clinical outcome and guide the choice of optimal treatment. In this study RNA-seq analysis was applied to formalin-fixed paraffin-embedded (FFPE) tumor and matched normal tissue samples collected from Russian patients with PCa and BPH. We identified 3384 genes differentially expressed (DE) (FDR < 0.05) between tumor tissue of PCa patients and adjacent normal tissue as well as both tissue types from BPH patients. Overexpression of four of the discovered genes (ANKRD34B, NEK5, KCNG3, and PTPRT) was validated by RT-qPCR. Furthermore, the enrichment analysis of overrepresented microRNA and transcription factor (TF) recognition sites within DE genes revealed common regulatory elements of which 13 microRNAs and 53 TFs were thus linked to PCa for the first time. Moreover, 8 of these TFs (FOXJ2, GATA6, NFE2L1, NFIL3, PRRX2, TEF, EBF2 and ZBTB18) were found to be differentially expressed in this study making them not only candidate biomarkers of prostate cancer but also potential therapeutic targets.

MiR-129 predicts prognosis and inhibits cell growth in human prostate carcinoma.

MicroRNAs (miRNAs) are a class of small, well-conserved, non-coding RNAs that are increasingly identified as diagnostic and prognostic biomarkers in a number of cancers. Deregulated miR-129 is closely associated with tumorigenesis and cancer progression. However, the potential role of miR-129 in prostate cancer remains largely elusive. The present study investigated the role of miR-129 as a prognostic biomarker for tumor progression and clinical prognosis in prostate cancer patients. The examined prostate cancer tissues exhibited a significant reduction in miR-129 expression compared with the normal tissues (P=0.013). The expression levels of miR-129 were negatively correlated with histological grade (P<0.001), high preoperative prostate-specific antigen serum levels (P<0.001), pathological stage (P<0.001), high Gleason score (P<0.001), lymph node metastasis (P=0.002), angiolymphatic invasion (P=0.018), and biochemical recurrence (BCR; P=0.001). Use of the Kaplan-Meier analysis demonstrated that low miR-129 expression was closely associated with poorer BCR-free survival. Multivariate survival analysis indicated that miR-129 expression may be an independent prognostic marker for BCR-free survival in prostate cancer patients (P<0.001). Overexpression of miR-129 markedly attenuated prostate cancer cell growth by rescuing cell cycle-regulated protein expression. The present study suggests that miR-129 is downregulated in the cancerous tissues of prostate cancer patients, which was associated with poor BCR-free survival. Thus, it may be considered as a novel independent prognostic biomarker for prostate cancer. In addition, downregulation of miR-129 may serve a critical role in the proliferation of prostate cancer cells.

MiR-129-3p controls centrosome number in metastatic prostate cancer cells by repressing CP110.

The centrosome plays a key role in cancer invasion and metastasis. However, it is unclear how abnormal centrosome numbers are regulated when prostate cancer (PCa) cells become metastatic. CP110 was previously described for its contribution of centrosome amplification (CA) and early development of aggressive cell behaviour. However its regulation in metastatic cells remains unclear. Here we identified miR-129-3p as a novel metastatic microRNA. CP110 was identified as its target protein. In PCa cells that have metastatic capacity, CP110 expression was repressed by miR-129-3p. High miR-129-3p expression levels increased cell invasion, while increasing CP110 levels decreased cell invasion. Overexpression of CP110 in metastatic PCa cells resulted in a decrease in the number of metastasis. In tissues of PCa patients, low CP110 and high miR-129-3p expression levels correlated with metastasis, but not with the expression of genes related to EMT. Furthermore, overexpression of CP110 in metastatic PCa cells resulted in excessive-CA (E-CA), and a change in F-actin distribution which is in agreement with their reduced metastatic capacity. Our data demonstrate that miR-129-3p functions as a CA gatekeeper in metastatic PCa cells by maintaining pro-metastatic centrosome amplification (CA) and preventing anti-metastatic E-CA.

Perlecan/HSPG2 and matrilysin/MMP-7 as indices of tissue invasion: tissue localization and circulating perlecan fragments in a cohort of 288 radical prostatectomy patients.

Prostate cancer (PCa) cells use matrix metalloproteinases (MMPs) to degrade tissue during invasion. Perlecan/HSPG2 is degraded at basement membranes, in reactive stroma and in bone marrow during metastasis. We previously showed MMP-7 efficiently degrades perlecan. We now analyzed PCa tissue and serum from 288 prostatectomy patients of various Gleason grades to decipher the relationship between perlecan and MMP-7 in invasive PCa. In 157 prostatectomy specimens examined by tissue microarray, perlecan levels were 18% higher than their normal counterparts. In Gleason grade 4 tissues, MMP-7 and perlecan immunostaining levels were highly correlated with each other (average correlation coefficient of 0.52) in PCa tissue, regardless of grade. Serial sections showed intense, but non-overlapping, immunostaining for MMP-7 and perlecan at adjacent borders, reflecting the protease-substrate relationship. Using a capture assay, analysis of 288 PCa sera collected at prostatectomy showed elevated levels of perlecan fragments, with most derived from domain IV. Perlecan fragments in PCa sera were associated with overall MMP-7 staining levels in PCa tissues. Domain IV perlecan fragments were present in stage IV, but absent in normal, sera, suggesting perlecan degradation during metastasis. Together, perlecan fragments in sera and MMP-7 in tissues of PCa patients are measures of invasive PCa.

ENOS gene polymorphisms in paraffin-embedded tissues of prostate cancer patients.

The purpose of the present study was to investigate whether endothelial nitric oxide synthase (eNOS) gene polymorphisms play a role in prostate cancer (PCa). We examined three eNOS gene polymorphisms (T-786C promoter region, G894T, and Intron 4 VNTR 4a/b) at extracted DNAs from 50 formalin-fixed paraffin-embedded tissues of PCa patients. For the controls, blood samples obtained from 50 healthy men were studied. Genotyping of molecular variants was performed by PCR-RFLP technique. We found that the TC genotype of the T-786C polymorphism was associated with PCa risk (OR: 3.325, CI: 1.350-8.188, P = 0.008). The eNOS G894T polymorphism was also associated with PCa. The frequency of the 894T allele was significantly higher in PCa patients. No association was identified between intron 4 VNTR polymorphism and PCa. We found significant differences in genotypic and allelic frequencies between PCa patients and controls for eNOS T-786C and G894T polymorphisms. The presence of the T-786C genotype and 894T allele in carriers increased the risk of PCa. No association was found between intron 4 VNTR polymorphism and PCa patients.

Abstract 4758: Genomic profiling of prostate cancer in Korean population

Abstract Prostate cancer is one of the most common cancers for male population in the world. The search for accurate biomarkers in prostate cancer is critical for evolution of accurate management of prostate cancer. Previous studies have identified that several genomic alterations in prostate cancer including TMPRSS2-ERG fusion, PTEN deletion and SPOP single nucleotide variants (SNVs), the majority of which are from western population. To characterize the somatic mutations of prostate cancer in Korean, we sequenced the whole exome of 49 prostate cancer patient tissues and matched normal tissues. A total of 738 somatic non-silent variants affecting 692 distinct genes were identified. In addition to already known genes (SPOP, FOXA1 and PTEN), we also found previously uncharacterized genes such as GRIN2A, LRP1, LRP1B and KRT1. Of the 40 mutated genes across multiple cases, missense SNVs of SPOP (5/49 cases, 10.2%) were the most frequent, followed by missense and splice-site SNVs of GRIN2A (4/49 cases, 8.2%). Mutations in low density lipoprotein-related protein encoded by LRP1 and LRP1B affected considerable portion of all cases (7/49, 14.3%), describe the probable relation between lipid metabolism and prostate cancer. As a results, we suggested the distinct patterns of genetic variations involved in prostate cancer of Korean population. Note: This abstract was not presented at the meeting. Citation Format: Ha Young Park, Jong-il Kim, Weon Seo Park, Kang Hyun Lee. Genomic profiling of prostate cancer in Korean population. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 4758. doi:10.1158/1538-7445.AM2015-4758

Abstract 207: Caveolin-1 drives oncogenic TGFβ effects in prostate cancer: in vitro mechanistic insights integrated with systems pathology visualization in primary tumor samples

Abstract Caveolin-1 (Cav1) can have both a tumor suppressive or promoting role depending on cancer tissue, and its potential active role in the progression of prostate cancer remains poorly understood. In this study, we found out that Cav1 represses the expression of E-cadherin in prostate cancer cell lines, and that the expressions of these two genes show an inverse correlation both at the mRNA and protein levels in PCa patient samples. We show that the combined loss of E-cadherin and gain of Cav1 expression is an early event in a subgroup of patients (&amp;lt;10%) (n(patients) = 80, n(glands) = 263, r = -0.35, p&amp;lt;0.001). Cav1 positively regulates TGFβ targets with known oncogenic and pro-EMT functions (e.g. Slug, Pai-1), and its absence switches the TGFβ to become inhibitory to PCa cells by inducing p21 (CDKN1A) and STAT1 signaling. These changes were strongly associated with changes in 3D-invasive growth. By using RNAi image-based screening, we found out that Cav1 is positively regulated by beta1-integrins and cell adhesion to ECM. This association together with different alpha-integrins was visualized and quantified in human prostate cancer patient tissues (n = 80) using novel multiplexed fluorescent imaging. Both the integrin beta1 and alpha2 showed high correlation with Cav1 expression (p-values&amp;lt;0.001) in tumor epithelium as well as in stroma. In conclusion, the results suggest that Cav1 could be an important promoter of invasive growth in a subgroup of PCa, where it is upregulated by beta1-integrins, and where it promotes oncogenic TGFβ signaling. Citation Format: Teijo Pellinen, Sami Blom, Sara Sanches, Katja Välimäki, John-Patrick Mpindi, Antti Rannikko, Raffaele Strippoli, Maria Montoya, Hind Azegrouz, Tuomas Mirtti, Miguel del Pozo, Olli Kallioniemi. Caveolin-1 drives oncogenic TGFβ effects in prostate cancer: in vitro mechanistic insights integrated with systems pathology visualization in primary tumor samples. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 207. doi:10.1158/1538-7445.AM2015-207

Altered endosome biogenesis in prostate cancer has biomarker potential.

Prostate cancer is the second most common form of cancer in males, affecting one in eight men by the time they reach the age of 70 years. Current diagnostic tests for prostate cancer have significant problems with both false negatives and false positives, necessitating the search for new molecular markers. A recent investigation of endosomal and lysosomal proteins revealed that the critical process of endosomal biogenesis might be altered in prostate cancer. Here, a panel of endosomal markers was evaluated in prostate cancer and nonmalignant cells and a significant increase in gene and protein expression was found for early, but not late endosomal proteins. There was also a differential distribution of early endosomes, and altered endosomal traffic and signaling of the transferrin receptors (TFRC and TFR2) in prostate cancer cells. These findings support the concept that endosome biogenesis and function are altered in prostate cancer. Microarray analysis of a clinical cohort confirmed the altered endosomal gene expression observed in cultured prostate cancer cells. Furthermore, in prostate cancer patient tissue specimens, the early endosomal marker and adaptor protein APPL1 showed consistently altered basement membrane histology in the vicinity of tumors and concentrated staining within tumor masses. These novel observations on altered early endosome biogenesis provide a new avenue for prostate cancer biomarker investigation and suggest new methods for the early diagnosis and accurate prognosis of prostate cancer. This discovery of altered endosome biogenesis in prostate cancer may lead to novel biomarkers for more precise cancer detection and patient prognosis.

Immunohistochemical expression of interleukin-2 receptor and interleukin-6 in patients with prostate cancer and benign prostatic hyperplasia: Association with asymptomatic inflammatory prostatitis NIH category IV

Objective. This study prospectively investigated the immunohistochemical expression of interleukin-2 receptor (IL-2R) and interleukin-6 (IL-6) in patients with prostate cancer and benign prostatic hyperplasia (BPH), and a possible association of these conditions with asymptomatic inflammatory prostatitis National Institutes of Health (NIH) category IV. Materials and methods. The study included 139 consecutive patients who underwent transurethral resection of the prostate and transvesical enucleation of the prostate (n = 82) or radical prostatectomy (n = 57). To characterize inflammatory changes the criteria proposed by Irani et al. [J Urol 1997;157:1301–3] were used. IL-2R and IL-6 expression was studied by a standard immunohistochemical method. Results were correlated with tumour, node, metastasis stage, Gleason scores, total prostate-specific antigen, International Prostate Symptom Score and body mass index. Results. IL-2R and IL-6 expression was significantly higher in neoplastic prostate cancer tissue than in normal tissue of prostate cancer patients (p < 0.001 and p < 0.04, respectively). Prostate cancer patients with prostatitis showed significantly higher IL-2R expression than those without inflammation (p < 0.03). In patients with BPH, expression of IL-2R as well as IL-6 was higher in patients with prostatitis than in those without (p < 0.01 and p < 0.02, respectively). Conclusions. IL-2R and IL-6 expression was significantly higher in prostate cancer tissue than in normal tissue. Patients with asymptomatic inflammatory prostatitis NIH category IV showed significantly greater activity.

Novel method to characterize immune cells from human prostate tissue.

Benign prostatic hyperplasia (BPH) is the most common benign adenoma and prostate cancer is the most frequent malignancy in men over 50 years of age in the Western world, where it remains a significant health problem. Prostate lesions are known to contain immune cells, which may contribute to the immune control of tumor progression. However, due to their low numbers and restricted access to necessary material it is difficult to isolate immune cells from prostate tissue to characterize their immunological features. An efficient and robust method was developed to process prostate tissue and isolate immune cells for phenotypic analysis by multicolor flow cytometry as downstream application. Fresh prostate tissue from 11 patients undergoing surgery for bladder outlet obstruction due to BPH was processed to evaluate the number, viability, yield, and frequency of various immune cell types. The presented method does not include enzymatic digestion nor incubation steps at 37 °C, increasing cellular viability and avoiding possible phenotypic modification. Various immune cell populations were detected in all patient samples and the median cellular viability was 90%. The number of detected events of individual cell populations varied between patients. The median frequency of different immune cell populations also varied, being 87% for the CD3- and 15% for the CD3+ cell population. This novel method will allow the phenotypic characterization of immune cell populations present in tumor tissue of prostate cancer patients and promote development of novel approaches to immunotherapy of the disease.

The RelB alternative NF-kappaB subunit promotes autophagy in 22Rv1 prostate cancer cells in vitro and affects mouse xenograft tumor growth in vivo.

BackgroundThe involvement of NF-κB signaling in prostate cancer (PCa) has largely been established through the study of the classical p65 subunit. Nuclear localization of p65 in PCa patient tissues has been shown to correlate with biochemical recurrence, while in vitro studies have demonstrated that the classical NF-κB signaling pathway promotes PCa progression and metastatic potential. More recently, the nuclear location of RelB, a member of the alternative NF-κB signaling, has also been shown to correlate with the Gleason score. The current study aims to clarify the role of alternative NF-κB in PCa cells by exploring, in vitro and in vivo, the effects of RelB overexpression on PCa biology.MethodsUsing a lentivirus-expression system, we constitutively overexpressed RelB or control GFP into 22Rv1 cells and monitored alternative transcriptional NF-κB activity. In vivo, tumor growth was assessed after the injection of 22Rv1-derived cells into SCID mice. In vitro, the impact of RelB on 22Rv1 cell proliferation was evaluated in monolayer culture. The anchorage-independent cell growth of derived-22Rv1 cells was assessed by soft agar assay. Apoptosis and autophagy were evaluated by Western blot analysis in 22Rv1-derived cells cultured in suspension using poly-HEMA pre-coated dishes.ResultsThe overexpression of RelB in 22Rv1 cells induced the constitutive activation of the alternative NF-κB pathway. In vivo, RelB expression caused a lag in the initiation of 22Rv1-induced tumors in SCID mice. In vitro, RelB stimulated the proliferation of 22Rv1 cells and reduced their ability to grow in soft agar. These observations may be reconciled by our findings that, when cultured in suspension on poly-HEMA pre-coated dishes, 22Rv1 cells expressing RelB were more susceptible to cell death, and more specifically to autophagy controlled death.ConclusionsThis study highlights a role of the alternative NF-κB pathway in proliferation and the controlled autophagy. Thus, the interplay of these properties may contribute to tumor survival in stress conditions while promoting PCa cells growth contributing to the overall tumorigenicity of these cells.

Functional Epigenetic Analysis of Prostate Carcinoma: A Role for Seryl-tRNA Synthetase?

Transcriptional silencing, as a result of aberrant promoter hypermethylation, is a common mechanism through which genes in cancer cells become inactive. Functional epigenetic screens using demethylating agents to reexpress transcriptional silenced genes may identify such inactivated genes for needing further evaluation. We aimed to identify genes so far not known to be inactivated by promoter hypermethylation in prostate cancer. DU-145 and LNCaP cells were treated with the DNMT inhibitor zebularine. Expression changes of total RNA from treated and untreated cells were compared using an RNA expression microarray. Genes upregulated more than 2-fold were evaluated by RT-qPCR in 50 cases of paired normal and tumor tissues of prostate cancer patients. SARS was found to be downregulated in prostate cancer in 42/50 cases (84%). In addition, GADD45A and SPRY4 showed a remarkable diminished expression (88% and 74%, resp.). The gold standard for promoter hypermethylation-inactivated genes in prostate cancer (GSTP1) was repressed in 90% of our patient samples. ROC analyses reported statistically significant AUC curves in SARS, GADD45A, and GSTP1 and positive Spearman correlations were found between these genes. SARS was discovered to be a novel gene that is repressed in prostate cancer and could therefore be recommended for its involvement in prostate carcinogenesis.

Abstract 3011: The role of peroxidasin in human prostate cancer.

Abstract Peroxidasin is a peroxidase associated with kidney disease and its function is not totally known. Peroxidasin was identified first in the common fruit fly, or Drosophilia, where its function has not been identified, but is expressed in different stages of development. When peroxidasin was identified in the human system, it was found in colon cancer cell lines as the product of a p-53 response gene. It was originally called melanoma gene 50 because it was speculated to be a potent-melanoma associated antigen. In previous studies, we have found using real-time PCR array, that peroxidasin is up regulated 300-fold in ARCaP prostate cancer cell line overexpressing Snail transcription factor. Snail is the transcriptional factor that is involved in Epithelial-Mesenchymal Transition, or EMT, which is associated with increased migration and metastasis. Snail down-regulates cell-cell association genes like E-cadherin and up-regulates mesenchymal genes like vimentin. We hypothesized that the enzyme, peroxidasin, will be one of the causes for increased cellular migration and increased tumor progression in aggressive prostate cancer. By using Western Blot, immunofluorescence and immunohistochemical analyses, peroxidasin presence was examined in normal prostate epithelial tissue, prostate cancer patient tissue, non-metastatic and metastatic prostate cancer cell lines. We also utilized LNCaP and ARCaP prostate cancer cell lines that were modified to over-express Snail to better ascertain the regulation of peroxidasin by Snail in these cell lines. So far, we have found that peroxidasin is increased in prostate cancer patient tissue as compared to normal epithelial tissue. Peroxidasin is also expressed at varying levels in prostate cancer cell lines. LNCaP and ARCaP Snail-transfected cells also expressed more peroxidasin as compared to empty vector Neo control cells. Migration, invasion, and adhesion assays will be performed to examine the role of peroxidasin in these biological pathways. Based on the results, future studies will focus on the migration of prostate cancer cells towards nerve cells and if peroxidasin presence is significant to this process. Overall, we have shown that peroxidasin is highly expressed in prostate cancer and its expression is mediated by Snail transcription factor. Supported by grants P20MD002285-01 &amp; G12RR003062-22. Citation Format: Keith Woods. The role of peroxidasin in human prostate cancer. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 3011. doi:10.1158/1538-7445.AM2013-3011

Abstract 5063: Matrilysin cleavage of perlecan produces bioactive fragments acting as a molecular switch to alter prostate cancer cell behavior.

Abstract Perlecan/HSPG2[PLN], a large heparan sulfate (HS) proteoglycan, is expressed in the basement membrane (BM) underlying epithelial and endothelial cells. During prostate cancer (PCa) cell invasion, a variety of proteolytic enzymes are expressed that digest BM components including PLN. After proteolysis, fragments of PLN can be released into circulation. A sandwich ELISA with antibodies generated across PLN detected fragments of PLN from IG-repeat domain IV in PCa patient serum. An enzyme upregulated in invasive PCa cells, matrilysin/matrix metalloproteinase-7 (MMP-7), was examined as a candidate for PLN proteolysis both in silico and in vitro. Purified PLN showed high sensitivity to MMP-7 digestion even when fully decorated with HS or when embedded with other BM proteins. MMP-7 fragments of PLN were detected as limit peptides by western blot. While not predicted in silico, MMP-7 cleaved every subpart of recombinantly generated PLN domain IV. The resultant MMP-7 generated PLN Dm IV fragments were identified by mass spectrometry (LC-MS/MS and MALDI) and Edman degradation N-terminal sequencing. Other PCa relevant enzymes had limited ability to cleave PLN including prostate specific antigen, hepsin and fibroblast activation protein. To determine if PLN digestion affects metastatic PCa cells, C4-2B cells were seeded on plates coated with different forms of PLN. Cells on intact PLN formed large clusters of poorly adherent cells, while those on PLN digested with MMP-7 or heparitinase to remove the HS chains attached and spread within 30 minutes. Immunohistochemistry of PCa patient tissue indicates MMP-7 and PLN are in direct contact at interfaces in the stroma. We conclude that enzymatic processing of PLN in the BM and stroma as occurs in the tumor microenvironment can alter PCa cell behavior and favor cell dispersion and invasiveness. Citation Format: Brian J. Grindel. Matrilysin cleavage of perlecan produces bioactive fragments acting as a molecular switch to alter prostate cancer cell behavior. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 5063. doi:10.1158/1538-7445.AM2013-5063

Identification, characterization and targeting of Docetaxel-resistant prostate cancer cells

Identification, characterization and targeting of Docetaxel-resistant prostate cancer cells

The tale of xenotropic murine leukemia virus-related virus.

In 2006, a new retrovirus was isolated from prostate cancer patient tissue. Named xenotropic murine leukemia virus-related virus (XMRV), this was potentially the third class of retrovirus to be pathogenic in humans. XMRV made a more dramatic impact on the wider scientific community, and indeed the media, in 2009 when it was reported to be present in a remarkably high proportion of patients with chronic fatigue syndrome as well as a significant, albeit smaller, proportion of healthy controls. The apparent strong link to disease and the fear of a previously unknown retrovirus circulating in the general population lead to a surge in XMRV research. Subsequent studies failed to find an association of XMRV with disease and, in most cases, failed to find the virus in human samples. In 2011, the case against XMRV and human disease strengthened, ending with several decisive publications revealing the origin of the virus and demonstrating contamination of samples. In this review, we outline the passage of research on XMRV and its potential association with disease from its isolation to the present day, where we find ourselves at the end of a turbulent story.

Absence of XMRV in Peripheral Blood Mononuclear Cells of ARV-Treatment Naïve HIV-1 Infected and HIV-1/HCV Coinfected Individuals and Blood Donors

BackgroundXenotropic murine leukemia virus-related virus (XMRV) has been found in the prostatic tissue of prostate cancer patients and in the blood of chronic fatigue syndrome patients. However, numerous studies have found little to no trace of XMRV in different human cohorts. Based on evidence suggesting common transmission routes between XMRV and HIV-1, HIV-1 infected individuals may represent a high-risk group for XMRV infection and spread.Methodology/Principal FindingsDNA was isolated from the peripheral blood mononuclear cells (PBMCs) of 179 HIV-1 infected treatment naïve patients, 86 of which were coinfected with HCV, and 54 healthy blood donors. DNA was screened for XMRV provirus with two sensitive, published PCR assays targeting XMRV gag and env and one sensitive, published nested PCR assay targeting env. Detection of XMRV was confirmed by DNA sequencing. One of the 179 HIV-1 infected patients tested positive for gag by non-nested PCR whereas the two other assays did not detect XMRV in any specimen. All healthy blood donors were negative for XMRV proviral sequences. Sera from 23 HIV-1 infected patients (15 HCV+) and 12 healthy donors were screened for the presence of XMRV-reactive antibodies by Western blot. Thirteen sera (57%) from HIV-1+ patients and 6 sera (50%) from healthy donors showed reactivity to XMRV-infected cell lysate.Conclusions/SignificanceThe virtual absence of XMRV in PBMCs suggests that XMRV is not associated with HIV-1 infected or HIV-1/HCV coinfected patients, or blood donors. Although we noted isolated incidents of serum reactivity to XMRV, we are unable to verify the antibodies as XMRV specific.