Prognostic Marker In Prostate Cancer Research Articles

RSPO3 is a prognostic biomarker and mediator of invasiveness in prostate cancer

BackgroundWhile prostate cancer can often manifest as an indolent disease, the development of locally-advanced or metastatic disease can cause significant morbidity or mortality. Elucidation of molecular mechanisms contributing to disease progression is crucial for more accurate prognostication and effective treatments. R-Spondin 3 (RSPO3) is a protein previously implicated in the progression of colorectal and lung cancers. However, a role for RSPO3 in prostate cancer prognosis and behaviour has not been explored.MethodsWe compare the relative levels of RSPO3 expression between normal prostate tissue and prostate cancer in two independent patient cohorts (Taylor and GSE70768—Cambridge). We also examine the association of biochemical relapse with RSPO3 levels in these cohorts. For elucidation of the biological effect of RSPO3, we use siRNA technology to reduce the levels of RSPO3 in established prostate cancer cell lines, and perform in vitro proliferation, invasion, western blotting for EMT markers and clonogenic survival assays for radiation resistance. Furthermore, we show consequences of RSPO3 knockdown in an established chick chorioallantoic membrane (CAM) assay model of metastasis.ResultsRSPO3 levels are lower in prostate cancer than normal prostate, with a tendency for further loss in metastatic disease. Patients with lower RSPO3 expression have lower rates of biochemical relapse-free survival. SiRNA-mediated loss of RSPO3 results in no change to clonogenic survival and a lower proliferative rate, but increased invasiveness in vitro with induction of epithelial–mesenchymal transition (EMT) markers. Consistent with these results, lower RSPO3 expression translates to greater metastatic capacity in the CAM assay. Together, our preclinical findings identify a role of RSPO3 downregulation in prostate cancer invasiveness, and provide a potential explanation for how RSPO3 functions as a positive prognostic marker in prostate cancer.

Evaluation of neutrophil-to-lymphocyte ratio as a prognostic indicator in a Singapore cohort of patients with clinically localized prostate cancer treated with prostatectomy

Recent evidence suggests that the presence of a systemic inflammatory response plays an important role in the progression of several solid tumors. The neutrophil-to-lymphocyte ratio (NLR) has been proposed as easily assessable markers of systemic inflammation and has been shown to represent a prognostic marker in prostate cancer in previous studies. Data from 668 patients with localized prostate cancer treated with prostatectomy (open and robot assisted) in Singapore General Hospital from 1998 to 2014 were analyzed. Correlation between NLR and histopathological status was analyzed. Association between NLR and distant metastases-free survival (MFS), cancer-specific survival (CSS), overall survival (OS), and biochemical disease-free survival (BDFS) was assessed. NLR was not significantly correlated with histopathological status, including Gleason score (≤6 versus 7 versus ≥8, p = 0.159), lymph node metastasis (negative versus positive, p=0.159), or surgical margin status (negative versus positive, p =0.494). NLR was categorized into two groups (< median and≥median, median = 2.09) and NLR ≥ 2.09 was not a prognostic factor for decreased MFS (p = 0.609), CSS (p = 0.302), OS (p = 0.722) and BDFS (p = 0.589). No difference was observed for NLR even in high-risk subgroup patients compared to the rest (p = 0.058). The area under the ROC curve (AUC) of NLR as a prognosticator for biochemical recurrence was only 0.53. Our findings indicate that pre-treatment NLR may not predict prognosis in patients with localized prostate cancer treated with prostatectomy in an Asian cohort.

A nuclear shift of GSK3β protein is an independent prognostic factor in prostate cancer.

Glycogen synthase kinase 3ß (GSK3ß) regulates many cancer relevant cellular processes and represents a potential therapeutic target. GSK3ß overexpression has been linked to adverse tumor features in many cancers, but its role in prostate cancer remains uncertain. We employed immunohistochemical GSK3ß expression analysis on a tissue microarray with 12,427 prostate cancers. Cytoplasmic and nuclear GSK3ß staining was separately analyzed. GSK3ß staining was absent in normal prostate epithelium, whereas 57% of 9,164 interpretable cancers showed detectable GSK3ß expression. Cytoplasmic staining was considered weak, moderate, and strong in 36%, 19.5% and 1.5% of tumors and was accompanied by nuclear GSK3ß staining in 47% of cases. Cytoplasmic GSK3ß staining as well as nuclear GSK3ß accumulation was associated with advanced tumor stage, high Gleason grade, presence of lymph node metastasis and early biochemical recurrence (p < 0.0001 each for cytoplasmic staining and nu-clear accumulation). Prognosis of GSK3ß positive cancers became particularly poor if nuclear GSK3ß staining was also seen (p < 0.0001). The prognostic impact of nuclear GSK3ß accumu-lation was independent of established preoperative and postoperative parameters in multivari-ate analyses (p < 0.0001). The significant association of GSK3ß expression with deletions of PTEN, 3p13 (p < 0.0001 each), 5q21 (p = 0.0014) and 6q15 (p = 0.0026) suggest a role of GSK3ß in the development of genomic instability. In summary, the results of our study identify GSK3ß as an independent prognostic marker in prostate cancer.

Aberrant expression of the microtubule-associated protein tau is an independent prognostic feature in prostate cancer

BackgroundMicrotubule-associated protein Tau (MAPT) overexpression has been linked to poor prognosis and decreased response to taxane-based therapies in several cancer types, but its relevance in prostate cancer is unknown.MethodsIn this study, MAPT expression was analyzed by immunohistochemistry on a tissue microarray containing 17,747 prostate cancers.ResultsMAPT was absent in normal prostate epithelial cells but detectable in 1004 (8.2%) of 12,313 interpretable cancers. Its expression was associated with advanced tumor stage, high Gleason grade, positive lymph nodes, and early biochemical recurrence (p < 0.0001 each). For example, MAPT was found in 3.6% of 2072 Gleason ≤3 + 3 cancers but in 14.4% of 704 Gleason ≥4 + 4 cancers. High-level MAPT staining was also linked to TMPRSS2:ERG fusions (p < 0.0001). MAPT staining was seen in 15.2 and 16% of cancers with TMPRSS2:ERG fusion detected by immunohistochemistry and fluorescence in-situ hybridization, but in only 3.5 and 3.9% of cancers without ERG staining or ERG rearrangements. Moreover, an association was found between MAPT expression and PTEN deletions, with 19% MAPT positivity in 948 PTEN deleted cancers but only 7% MAPT positivity in 3895 tumors with normal PTEN copy numbers (p < 0.0001). Multivariate analysis revealed that the prognostic value of MAPT was independent from established parameters. Conventional large section analyses showed intratumoral MAPT heterogeneity in all three analyzed cancers.ConclusionsThe results of our study identify MAPT, as a moderate prognostic marker in prostate cancer, whose clinical impact, however, may be limited due to the rarity and heterogeneity of its expression.

Identification of prognostic biomarkers of prostate cancer with long non-coding RNA-mediated competitive endogenous RNA network.

Prostate cancer (PCa) is the second most frequently diagnosed male cancer, and no treatments exist for effective inhibition of metastatic spread of PCa. Long non-coding RNA (lncRNA) plays key roles in pathogenesis and development of various cancers through competing with endogenous RNAs (ceRNAs), but at present research on lncRNA functions in PCa is still very limited. Hence, this aspect was investigated using bioinformatics methods. Firstly, the functional lncRNA-mediated ceRNA network associated with PCa was constructed by the multi-step computational approach. Then the cytoscape software was used to analyze the node degree and betweenness centrality (BC) value of lncRNAs and mRNAs in the interaction. Finally, the lncRNAs were screened in the central region of the network by the node degree and BC value, and the functional enrichment of mRNAs was evaluated with the Gene Ontology (GO) database. In our results, LINC00476, MALAT1, SNHG11, LINC00649, and ILF3-AS1 are the lncRNAs which have the most nodes and higher BC values and considered as prognostic markers in PCa. GO analysis suggested that the function of screened lncRNAs was obviously focused on intracellular receptor signaling pathway, which indicated these lncRNAs might be potential biomarkers for diagnosis, evaluation and gene-targeted therapy of PCa.

The preoperative neutrophil-to-lymphocyte ratio is not a marker of prostate cancer characteristics but is an independent predictor of biochemical recurrence in patients receiving radical prostatectomy.

The neutrophil‐to‐lymphocyte ratio (NLR) has been reported to be a prognostic marker in prostate cancer. In this study, we assessed the association between preoperative NLR and the clinicopathological characteristics, biomolecular features and prognosis of patients with localized prostate cancer treated with radical prostatectomy. A total of 994 subjects were retrospectively enrolled, and the histological specimens of 210 patients were retrieved for constructing a tissue microarray. Immunohistochemistry was then performed to assess the expression of AR, ERG, PTEN, p‐AKT, Bcl‐2, Beclin‐1, Ki‐67, CD3, CD4, CD8, IFN‐γ and TNF‐α. No significant differences in the NLR distributions among clinicopathological variables were observed (P > 0.05) when the original NLR data were utilized. When we dichotomized the NLR value into the high‐NLR group (NLR ≥ 2) and low‐NLR group (NLR < 2), we found that the patients in the high‐NLR group had more prostate capsule invasion (P = 0.047). Additionally, no significant correlation was found between the NLR and infiltrating CD3+ cells, the CD4/CD8 ratio, AR, ERG, PTEN, p‐AKT, Bcl‐2, Beclin‐1, Ki‐67, IFN‐γ or TNF‐α (P > 0.05). When we analyzed the data of patients without postoperative adjuvant hormone therapy or radiotherapy, univariate and multivariate survival analysis indicated that a high NLR was a predictor of better BCR‐free survival (P < 0.05). When analyzing the entire cohort, univariate survival analysis showed that the high‐NLR group had significantly poorer overall survival (P < 0.05). In conclusion, NLR cannot reflect prostate cancer characteristics or the local immune microenvironment, but a high NLR can serve as an independent predictor of better BCR.

Proteogenomic Characterization of Patient-Derived Xenografts Highlights the Role of REST in Neuroendocrine Differentiation of Castration-Resistant Prostate Cancer.

An increasing number of castration-resistant prostate cancer (CRPC) tumors exhibit neuroendocrine (NE) features. NE prostate cancer (NEPC) has poor prognosis, and its development is poorly understood.Experimental Design: We applied mass spectrometry-based proteomics to a unique set of 17 prostate cancer patient-derived xenografts (PDX) to characterize the effects of castration in vivo, and the proteome differences between NEPC and prostate adenocarcinomas. Genome-wide profiling of REST-occupied regions in prostate cancer cells was correlated to the expression changes in vivo to investigate the role of the transcriptional repressor REST in castration-induced NEPC differentiation. An average of 4,881 proteins were identified and quantified from each PDX. Proteins related to neurogenesis, cell-cycle regulation, and DNA repair were found upregulated and elevated in NEPC, while the reduced levels of proteins involved in mitochondrial functions suggested a prevalent glycolytic metabolism of NEPC tumors. Integration of the REST chromatin bound regions with expression changes indicated a direct role of REST in regulating neuronal gene expression in prostate cancer cells. Mechanistically, depletion of REST led to cell-cycle arrest in G1, which could be rescued by p53 knockdown. Finally, the expression of the REST-regulated gene secretagogin (SCGN) correlated with an increased risk of suffering disease relapse after radical prostatectomy. This study presents the first deep characterization of the proteome of NEPC and suggests that concomitant inhibition of REST and the p53 pathway would promote NEPC. We also identify SCGN as a novel prognostic marker in prostate cancer.

MicroRNAs as prognostic markers in prostate cancer

Prostate cancer (PCa) is the most commonly diagnosed malignancy in men who are especially over the age of 50 years in the western countries. Currently used therapeutic modalities mostly fail to give positive clinical outcomes and nearly 30% of the PCa patients eventually develop clinical recurrence. Therefore, understanding the underlying mechanisms of PCa progression is of paramount importance to help determining the course of disease. In this study, we aimed at profiling the differentially expressed microRNAs in recurrent PCa samples. We profiled the microRNA expression of 20 recurrent and 20 non-recurrent PCa patients with microRNA microarray, and validated the differential expression of significantly deregulated microRNAs in 40 recurrent and 39 non-recurrent PCa specimens using quantitative reverse-transcription PCR (qRT-PCR). Data were statistically analyzed using two-sided Student's t-test, Pearson Correlation test, Receiver operating characteristic (ROC) analysis. Our results demonstrated that a total of 682 probes were significantly deregulated in recurrent versus non-recurrent PCa specimen comparison. Among those, we confirmed the significant downregulation of miR-424 and upregulation of miR-572 with further qRT-PCR analysis in a larger sample set. Further ROC analysis showed that these microRNAs have enough power to distinguish recurrent specimens from non-recurrent ones on their own. Here, we report that differential expression of miR-424 and miR-572 in recurrent PCa specimens can serve as novel biomarkers for prediction of PCa progression.

The Role of Immunohistochemical Analysis as a Tool for the Diagnosis, Prognostic Evaluation and Treatment of Prostate Cancer: A Systematic Review of the Literature

Background: Prostate cancer (PCa) is a heterogeneous disease that lends itself toward numerous therapeutic options depending on its risk stratification. One of the greatest challenges in PCa urologic practice is to select patients who should be referred for biopsy and, for those patients who are diagnosed with cancer, to differentiate between patients with indolent disease from those with an unfavorable prognosis and, to determine ideal patient management and avoid unnecessary interventions. Accordingly, there is a growing body of literature reporting immunohistochemical studies with the objective of determining a prostate cancer prognosis. Among the most frequent biomarkers studied are Ki-67, p53, PTEN, MYC, and ERG. Based on these findings, we systematically reviewed articles that assessed the role of these main prognostic markers in prostate cancer.Methods: Consistent with PRISMA guidelines, we performed a systematic literature search throughout the Web of Science and PubMed Medline databases. We considered all types of studies evaluating the role of Ki-67, p53, PTEN, MYC, and ERG immunohistochemical analysis in prostate cancer until July 2017.Results: We identified 361 articles, 44 of which were summarized in this review. Diagnostically, no single immunohistochemical marker was able to define a tumor as benign or malignant. Prognostically, Ki-67, p53, and MYC were related to the tumor grade given by Gleason score and to the tumor stage (higher levels related to higher tumor grade). Furthermore, Ki-67 was also related to higher PSA levels, shorter disease-free intervals and shorter tumor-specific survival; the latter was also related to p53. The loss of PTEN protein expression showed a higher association with biochemical recurrence and with a worse prognosis, beyond that predicted by the Gleason score and tumor stage. ERG staining also showed a strong association with biochemical recurrence.Conclusion: There are several studies relating immunohistochemical markers with clinical-laboratorial outcomes in prostate cancer, the most frequent being Ki-67, p53, ERG, PTEN, and MYC. However, none of these markers have been validated by literary consensus to be routinely applied in medical practice.

MiR-301a expression: Diagnostic and prognostic marker for prostate cancer

BackgroundProstate-specific antigen screening for prostate cancer (CaP) remains controversial. This study establishes the role of microRNA 301a (miR-301a) as a supplemental biomarker that can distinguish between patients with benign prostate hyperplasia and clinically significant CaP. We evaluate the ability of miR-301a to predict the adverse pathology of CaP. MethodsIn the first cohort, serum and prostate tumor samples were obtained from thirteen patients with Benign prostate hyperplasia (BPH), twelve patients with Gleason 6, and sixteen patients with Gleason 7 prostate adenocarcinoma. In the second cohort, 40 prostatectomy cases were selected (BPH:12, Gleason 6:12 and Gleason 7:16). MiRNA was extracted from serum and tumor samples. Quantitative reverse transcription-polymerase chain reaction was performed for detection of miR-301a. To understand the molecular role of miR-301a, we performed cell viability, Western blots, promoter analysis, overexpression, and silencing studies in BPH and DU-145 cell lines. ResultsMiR-301a demonstrated a significantly higher expression in both serum and tumor tissue in patients with CaP when compared to patients with BPH (P = 0.011 and 0.013 for serum and tissue expression, respectively). Expression of miR-301a in prostatectomy specimens correlated with increased Gleason score. We demonstrated that miR-301a inhibited the pro-apoptotic function of RUNX3, and activated ROCK1-mediated pro-survival signal in CaP. Silencing miR-301a initiated the pro-apoptotic function of RUNX3 by inhibiting ROCK1 expression in CaP cells. ConclusionsExpression of miR-301a could be a valuable adjunct tool for stratifying patients with elevated prostate-specific antigen, as well as those diagnosed with CaP. Including the miR-301a as an additional variable in MSKCC post-prostatectomy nomogram improved its ability in facilitating clinical decision-making.

RNAs as Candidate Diagnostic and Prognostic Markers of Prostate Cancer—From Cell Line Models to Liquid Biopsies

The treatment landscape of prostate cancer has evolved rapidly over the past five years. The explosion in treatment advances has been witnessed in parallel with significant progress in the field of molecular biomarkers. The advent of next-generation sequencing has enabled the molecular profiling of the genomic and transcriptomic architecture of prostate and other cancers. Coupled with this, is a renewed interest in the role of non-coding RNA (ncRNA) in prostate cancer biology. ncRNA consists of several different classes including small non-coding RNA (sncRNA), long non-coding RNA (lncRNA), and circular RNA (circRNA). These families are under active investigation, given their essential roles in cancer initiation, development and progression. This review focuses on the evidence for the role of RNAs in prostate cancer, and their use as diagnostic and prognostic markers, and targets for treatment in this disease.

Overexpression of AR-regulated lncRNA TMPO-AS1 correlates with tumor progression and poor prognosis in prostate cancer.

Prostate cancer (PCa) is a leading cause of death in males all over the world; besides, the diagnosis and therapy of it are still challenging. Researchers have revealed that long non-coding RNAs (lncRNAs) play important roles in the genesis and progression of human cancers, including PCa. Bioinformatics analysis and Kaplan-Meier survival analysis were utilized to confirm TMPO-AS1 as a diagnostic and prognostic marker. The TMPO-AS1 levels in both patient tissues and PCa cell lines were determined by qRT-PCR analysis. Moreover, the chromatin immunoprecipitation (ChIP) assay identified that TMPO-AS1 was a direct target of AR. The effect of overexpression or knockdown of TMPO-AS1 on cell proliferation, migration, cell cycle, and cell apoptosis was assessed by using CCK-8, transwell assays, and flow cytometric analysis, respectively. Based on primary screening, we found that TMPO-AS1 could be a useful diagnostic and prognostic marker for PCa, whose expression was upregulated in PCa samples and associated with poorer prognosis. Bioinformatics predictions revealed TMPO-AS1 was associated with a series of biological processes involved in PCa progression. In PCa cells, TMPO-AS1 was predominantly localized in the cytoplasm and directly down-regulated by AR. Gain/loss-of-function assays showed TMPO-AS1 overexpression increased cell proliferation by promoting cell cycle progression and promoted migration, but reduced apoptosis of PCa cells. In addition, TMPO-AS1 may be a diagnostic and prognostic marker in multiple cancer types. AR-regulated lncRNA TMPO-AS1 functioned as an oncogenic lncRNA in PCa, and may be a potential diagnostic and prognostic biomarker to be used as a therapeutic target for PCa.

The Urinary Sarcosine/Creatinine Ratio is a Potential Diagnostic and Prognostic Marker in Prostate Cancer.

BackgroundThe aim of this study was to evaluate the role of the urinary sarcosine/creatinine ratio in the diagnosis and prognosis of prostate cancer, using a sarcosine oxidase assay.Material/MethodsUrine samples were obtained from 203 patients with benign prostate hyperplasia (BPH) and 209 patients with prostate cancer. Levels of urinary sarcosine were measured using the sarcosine oxidase method. The urinary sarcosine/creatinine ratios were compared between the group of patients with BPH and the patients with prostate cancer. In the two patients groups, the urinary sarcosine/creatinine ratio was compared with the measurement of serum prostate-specific antigen (PSA) and the free/total (F/T) PSA ratio. Correlations between of the urinary sarcosine/creatinine ratio and the Gleason grade and stage of prostate cancer were analyzed.ResultsThere was a significant difference between the urinary sarcosine/creatinine ratio in the BPH group and prostate cancer group (P<0.01), which was independent of serum PSA. The receiver-operating characteristic (ROC) curve, and area under the curve (AUC) for the urinary sarcosine/creatinine ratio was significantly higher compared with the serum PSA and the F/T PSA ratio. There was a significant difference in the urinary sarcosine/creatinine ratio in patients with prostate cancer with Gleason score ≤6, 7, and ≥8, and between patients with metastatic and non-metastatic prostate cancer.ConclusionsThe urinary sarcosine/creatinine ratio was a diagnostic indicator of prostate cancer, for patients with a serum PSA level <10 ng/ml, and correlated with the Gleason score and with the presence of metastases (stage) of prostate cancer.

Quantitative perineural invasion is a prognostic marker in prostate cancer

This study aimed to investigate the prognostic value of a quantitative, detailed, yet practical analysis of perineural invasion in radical prostatectomy specimens in a high-risk prostate cancer cohort. A total of 114 patients with prostate cancer who underwent radical prostatectomy between 2000 and 2013 were analysed. Using S100 protein immunohistochemistry assisted in the detection of nerves. In the area of closest proximity of the tumour to the dorso-lateral margins, nerves were counted and the infiltration of nerves was categorised (0-3). Category 0 was nerves without immediate tumour-cell-contact. All nerves being fully surrounded by tumour (classical perineural carcinosis) were categorised group 3. Two further categories discriminated between nerves that were touched either by carcinoma cells below 50% of the circumference (category 1) or above (category 2). Perineural carcinosis (Pn1) was seen in 61.4% of cases and correlated positively with ISUP grades, pT categories and presence of intraductal carcinoma but failed significance on Kaplan-Meier analysis. A more quantitative analysis of percentual perineural involvement did demonstrate significant survival differences: cases with less than one Pn1-positive nerve in 5 high power fields had longer survival times. Incomplete perineural involvement (category 1-2) did not have a prognostic value, endorsing the current definition of perineural carcinosis as full circumferential encasement of a nerve by tumour cells. A quantitative analysis of the percentage of nerves positive for perineural invasion has a higher prognostic value than the classical dichotomous statement on the mere presence of perineural invasion.

PI3K pathway and Bcl-2 family. Clinicopathological features in prostate cancer

The phosphatidylinositol 3-kinase (PI3K)/AKT/mTOR pathways and Bcl-2 family play a central role in prostate cancer (PC). The aim was to determine influence in the biochemical progression in PC. To evaluate the association between clinic pathological and immunohistochemical variables, Spearman’s test was performed. Log-rank test and Kaplan–Meier curves were used for survival comparisons. To explore the correlation of the studied immunohistochemical parameters and the established prognostic variables with biochemical progression, univariate and multivariate Cox proportional Hazard regression analyses were performed. Spearman analysis showed correlation between stroma expression and tumor expression of PI3K with biochemical progression (p = .009, p = .004), respectively, and tumor immunohistochemical score with biochemical progression (p = .051). In the multivariate Cox regression model, only PI3K was retained as independent predictors of biochemical progression. In stroma expression, PI3K is (HR 0.172, 95% CI 0.065–0.452, p = .000); tumor expression, PI3K is (HR 0.087, 95% CI 0.026–0.293, p = .000), and tumor immunohistochemical score (HR 0.382, 95% CI 0.209–0.697 p = .002). Our results suggest a role for prostatic expression of PI3K was prognostic markers for PC. PI3K/AKT/mTOR and Bcl-2 family are becoming an important therapeutic target and predictive biomarkers of onset and progression of PC.

Hsp70 and gama-Semino protein as possible prognostic marker of prostate cancer.

In the United States, Prostate Cancer (PCa) is the leading cause of cancer-related mortality in men. PCa resulted in abnormal growth and function of prostate gland such as secretion of high level of gamma-seminoprotein (gama-SM)/Prostate-Specific Antigen (PSA) which could be detected in the blood. Beside gama-SM protein, the levels of heat shock proteins (Hsp70) were also observed significantly high. Therefore, gama-SM and Hsp70 are unique proteins with high potential for PCa therapeutics and diagnostics. High level of Hsp70 suppresses apoptosis, thus allowing PCa cells to exist; however, depletion of Hsp70 induces apoptosis in PCa cells. Gama-SM is the most prominent biomarker for PCa screening; however, its accuracy is still questionable. Thus, a more suitable streamline biomarker for PCa screening is urgently needed. Hsp70 and gama-SM proteins could be used as a revolutionary biomarker for PCa, and could help to identify possible therapeutic target(s). In this review article we will discuss the relationship between the Hsp70 and gama-SM proteins with PCa, their potential as a dual biomarker, and the possibility for both proteins being used as therapeutic targets.

Long non-coding RNA GAS5 and ZFAS1 are prognostic markers involved in translation targeted by miR-940 in prostate cancer.

Identification of prognostic biomarkers helps facilitate the prediction of patient outcomes as well as guide treatments. Accumulating evidence now suggests that long non-coding RNAs (lncRNAs) play key roles in tumor progression with diagnostic and prognostic values. However, little is known about the biological functions of lncRNAs and how they contribute to the pathogenesis of cancer. Herein, we performed weighted correlation network analysis (WGCNA) on 380 RNA-seq samples from prostate cancer patients to create networks comprising of microRNAs, lncRNAs, and protein-coding genes. Our analysis revealed expression modules that associated with pathological parameters. More importantly, we identified a gene module that is involved in protein translation and is associated with patient survival. In this gene module, we explored the regulation axis involving GAS5, ZFAS1, and miR-940. We show that GAS5, ZFAS1, and miR-940 are up-regulated in tumors relative to normal prostate tissues, and high expression of either lncRNA is an indicator of poor patient outcome. Finally, we constructed a co-expression network involving GAS5, ZFAS1, and miR-940, as well as the targets of miR-940. Our results show that GAS5 and ZFAS1 are targeted by miR-940 via NAA10 and RPL28. Taken together, co-expression analysis of gene expression profiling from RNA-seq can accelerate the identification and functional characterization of novel prognostic markers in prostate cancer.

Increased ERCC1 expression is linked to chromosomal aberrations and adverse tumor biology in prostate cancer

BackgroundAnimal model experiments have suggested a role of the DNA repair protein ERCC1 (Excision Repair Cross-Complementation Group 1) in prostate cancer progression.MethodsTo better understand the impact of ERCC1 protein expression in human prostate cancer, a preexisting tissue microarray (TMA) containing more than 12,000 prostate cancer specimens was analyzed by immunohistochemistry and data were compared with tumor phenotype, PSA recurrence and several of the most common genomic alterations (TMPRSS2:ERG fusions: deletions of PTEN, 6q, 5q, 3p).ResultsERCC1 staining was seen in 64.7% of 10,436 interpretable tissues and was considered weak in 37.1%, moderate in 22.6% and strong in 5% of tumors. High-level ERCC1 staining was linked to advanced pT stage, high Gleason grade, positive lymph nodes, high pre-operative serum PSA, and positive surgical margin status (p < 0.0001 each). High ERCC1 expression was strongly associated with an elevated risk of PSA recurrence (p < 0.0001). This was independent of established prognostic features. A subgroup analysis of cancers defined by comparable quantitative Gleason grades revealed that the prognostic impact was mostly driven by low-grade tumors with a Gleason 3 + 3 or 3 + 4 (Gleason 4: ≤5%). High ERCC1 expression was strongly associated with the presence of genomic alterations and expression levels increased with the number of deletions present in the tumor. These latter data suggest a functional relationship of ERCC1 expression with genomic instability.ConclusionThe results of our study demonstrate that expression of ERCC1 - a potential surrogate for genomic instability - is an independent prognostic marker in prostate cancer with particular importance in low-grade tumors.

Abstract 4435: Exosomal miR-3622a as prognostic marker in prostate cancer

Abstract Loss of chromosome (chr) 8p21 is a frequent genomic alteration in prostate cancer (PCa). Genomic deletions of this region increase significantly with tumor grade and are associated with tumor progression and poor prognosis. A common region of loss of heterozygosity (LOH) has been mapped to the chr8p21 locus that primarily harbors prostate-specific NKX3.1 homeobox gene. We recently demonstrated that this frequently deleted locus is associated with a cluster of microRNA genes- miR-3622a/b- that are lost in prostate cancer and play an important mechanistic role in PCa progression and metastasis. MicroRNA expression profiling in microdissected human PCa clinical tissues showed that miR-3622a/b expression is widely downregulated and is correlated with poor survival outcome in prostate cancer. Our analyses suggested that miR-3622a has potential as a prognostic and diagnostic marker for prostate cancer. Extending these findings, we explored the prognostic potential of serum miR-3622a in prostate cancer patients. Since exosomes provide an important source of non-invasive, circulating biomarkers and represent an enriched source of microRNAs for biomarker profiling, we profiled the microRNA content of exosomes derived from sera of prostate cancer patients. In a pilot study, we profiled exosomal miRNAs from a training cohort of individuals with benign prostate hyperplasia (BPH), an indolent form of PCa or aggressive metastatic PCa. Exosomes were isolated from sera of prostate cancer patients and integrity of exosomal preparations was confirmed by nanoparticle tracking analysis and Western blot analyses for exosomal markers. Expression analyses of exosomal miR-3622a expression showed that this miRNA is enriched in exosomes. Higher levels of miR-3622a were significantly associated with tumor stage and lymph node metastasis in a cohort of prostate cancer clinical specimens. Further, ROC (Receiver Operating Characteristic) analyses showed that exosomal miR-3622a expression can be a single significant parameter to discriminate between BPH and prostate cancer. Overall, our data suggests that exosomal miR-3622a is a promising prognostic biomarker for prostate cancer. patients. Citation Format: Thao Yang, Divya Bhagirath, Kirandeep Sekhon, Nathan Bucay, Shahana Majid, Varahram Shahryari, Marisa Shiina, Yutaka Hashimoto, Priyanka Kulkarni, Pritha Dasgupta, Mitsuho Imai-Sumida, Soichiro Yamamura, Z Laura Tabatabai, Kirsten Greene, Yuichiro Tanaka, Rajvir Dahiya, Guoren Deng, Sharanjot Saini. Exosomal miR-3622a as prognostic marker in prostate cancer [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 4435. doi:10.1158/1538-7445.AM2017-4435

Apurinic/apyrimidinic endonuclease 1 (APE1/Ref-1) overexpression is an independent prognostic marker in prostate cancer without TMPRSS2:ERG fusion.

Polymorphisms of the base excision repair gene APE1 may be associated with an increased risk for developing prostate cancer. In other cancer types, altered APE1 protein expression is a candidate prognostic marker. Using immunohistochemistry, we thus analyzed APE1 expression in 9763 prostate cancers in a tissue microarray (TMA) with attached clinical and molecular data. The comparison with normal prostate tissue revealed an upregulation of APE1 in cancer samples. APE1 immunostaining was considered weak in 20.2%, moderate in 36.7%, and strong in 33.4% of cancers. Strong APE1 expression was markedly more frequent in prostate cancers harboring the TMPRSS2:ERG fusion (52.9%) than in ERG-negative cancers (19.1%, P < 0.0001). Significant associations with Gleason grade, tumor stage, tumor grade, and early biochemical recurrence (P < 0.0001 each) were largely limited to ERG-negative tumors. Multivariable analysis revealed that the prognostic value of APE1 upregulation in ERG-negative prostate cancers was independent from established histopathological and clinical parameters. In conclusion, the results of our study demonstrate that APE1 overexpression is an independent prognostic marker, but exclusively in ERG-negative prostate cancers.