Prostate Cancer Tumor Samples Research Articles

Proteomic profiling of prostate cancer reveals molecular signatures under antiandrogen treatment

BackgroundTumorigenesis and progression of prostate cancer (PCa) are indispensably dependent on androgen receptor (AR). Antiandrogen treatment is the principal preference for patients with advanced PCa. However, the molecular characteristics of PCa with antiandrogen intervention have not yet been fully uncovered.MethodsWe first performed proteome analysis with 32 PCa tumor samples and 10 adjacent tissues using data-independent acquisition (DIA)- parallel accumulation serial fragmentation (PASEF) proteomics. Then label-free quantification (LFQ) mass spectrometry was employed to analyze protein profiles in LNCaP and PC3 cells.ResultsM-type creatine kinase CKM and cartilage oligomeric matrix protein COMP were demonstrated to have the potential to be diagnostic biomarkers for PCa at both mRNA and protein levels. Several E3 ubiquitin ligases and deubiquitinating enzymes (DUBs) were significantly altered in PCa and PCa cells under enzalutamide treatment, and these proteins might reprogram proteostasis at protein levels in PCa. Finally, we discovered 127 significantly varied proteins in PCa samples with antiandrogen therapy and further uncovered 4 proteins in LNCaP cells upon enzalutamide treatment.ConclusionsOur research reveals new potential diagnostic biomarkers for prostate cancer and might help resensitize resistance to antiandrogen therapy.

The Molecular, Immunologic, and Clinicodemographic Landscape of MYC-Amplified Advanced Prostate Cancer

BackgroundMYC is a commonly amplified, potentially targetable gene in prostate cancer (PCa). We sought to define the molecular, immunologic, and clinicodemographic landscape of MYC amplification (MYCamp) in advanced PCa to establish a rationale for personalized treatment combinations. MethodsHybrid capture-based comprehensive genomic profiling (CGP) was performed on PCa tumor samples. MYCamp = copy number ≥6 (CN). Patients treated between January 2011 and December 2020 were selected from a nationwide deidentified (280 clinics) EHR-derived clinicogenomic database (CGDB). ResultsOf 12,528 hormone-sensitive and castrate-resistant (CRPC) samples, MYCamp was detected in 10.6% (median CN = 8). MYCamp was more frequent in men with African versus European ancestry (12.9% vs. 10.2% P = .002), in metastatic vs. primary tissue (15.7% vs. 6.2% P < .001), and enriched in metastatic liver lesions (20.2%), but inversely associated with high microsatellite-instability (0.8% vs. 2.4%, P < .001). MYC CN≥15 was associated with PD-L1 expression (26.1% vs. 9.8%, P = .025). Amplification of AR, RAD21, LYN, CCND1, ZNF703, FGF3/4/19, and FGFR1 was enriched in MYCamp vs. MYCwt (all P < .001). In liquid samples with tumor fraction [TF]>0, MYCamp was detected in 2.0% (28/1,402), and 4.5% (20/445) with TF>20%. In the CGDB, (67 MYCamp and 658 MYCwt), patients received similar treatments; most received hormone therapies (35.8% MYCamp vs. 31.5% MYCwt) or chemotherapy (37.3% MYCamp vs. 27.7% MYCwt) as first therapy after CGP report. ConclusionMYCamp defines a biologically distinct subset of PCa patients and is characterized with multiple proxies of advanced disease. These data suggest that MYCamp may be prognostic; independent cohorts are needed to validate these findings.

The evolving landscape of prostate cancer somatic mutations.

BackgroundThe landscape of somatic mutations in prostate cancer (PCa) has quickly evolved over the past years.ResultsThis evolution was in part due to the improved quality and lower cost of genomic sequencing platforms available to an ever‐larger group of clinicians and researchers. The result of these efforts is a better understanding of early and late mutations that are enriched or nearly exclusive to treated PCa. There are, however, some important limitations to the current knowledge. The expanding variety of next‐generation sequencing (NGS) assays either capture a wide spectrum of mutations but at low coverage or are focused panels that cover a select number of genes, most often cancer‐related, at a deep coverage. Both of these approaches have their advantages, but ultimately miss low‐frequency mutations or fail to cover the spectrum of potential mutations. Additionally, some alterations, such as the common ETS gene fusions, require a mixture of DNA and RNA analysis to capture the true frequency. Finally, almost all studies rely on bulk PCa tumor samples, which fail to consider tumor heterogeneity. Given all these caveats, the true picture of the somatic landscape of PCa continues to develop.SummaryIn this review, the focus will be on how the landscape of mutations evolves during disease progression considering therapy. It will focus on a select group of early and late mutations and utilize SPOP mutations to illustrate recurrent alterations that may have clinical implications.

PITX1 Is a Regulator of TERT Expression in Prostate Cancer with Prognostic Power.

Simple SummaryMost prostate cancer is of an indolent form and is curable. However, some prostate cancer belongs to rather aggressive subtypes leading to metastasis and death, and immediate therapy is mandatory. However, for these, the therapeutic options are highly invasive, such as radical prostatectomy, radiation or brachytherapy. Hence, a precise diagnosis of these tumor subtypes is needed, and the thus far applied diagnostic means are insufficient for this. Besides this, for their endless cell divisions, prostate cancer cells need the enzyme telomerase to elongate their telomeres (chromatin endings). In this study, we developed a gene regulatory model based on large data from transcription profiles from prostate cancer and chromatin-immuno-precipitation studies. We identified the developmental regulator PITX1 regulating telomerase. Besides observing experimental evidence of PITX1′s functional role in telomerase regulation, we also found PITX1 serving as a prognostic marker, as concluded from an analysis of more than 15,000 prostate cancer samples.The current risk stratification in prostate cancer (PCa) is frequently insufficient to adequately predict disease development and outcome. One hallmark of cancer is telomere maintenance. For telomere maintenance, PCa cells exclusively employ telomerase, making it essential for this cancer entity. However, TERT, the catalytic protein component of the reverse transcriptase telomerase, itself does not suit as a prognostic marker for prostate cancer as it is rather low expressed. We investigated if, instead of TERT, transcription factors regulating TERT may suit as prognostic markers. To identify transcription factors regulating TERT, we developed and applied a new gene regulatory modeling strategy to a comprehensive transcriptome dataset of 445 primary PCa. Six transcription factors were predicted as TERT regulators, and most prominently, the developmental morphogenic factor PITX1. PITX1 expression positively correlated with telomere staining intensity in PCa tumor samples. Functional assays and chromatin immune-precipitation showed that PITX1 activates TERT expression in PCa cells. Clinically, we observed that PITX1 is an excellent prognostic marker, as concluded from an analysis of more than 15,000 PCa samples. PITX1 expression in tumor samples associated with (i) increased Ki67 expression indicating increased tumor growth, (ii) a worse prognosis, and (iii) correlated with telomere length.

LINC01207 promotes prostate cancer progression by sponging miR-1182 to upregulate AKT3.

Prostate cancer (PC) is recognized as a common malignancy in male patients. Long non-coding RNA (lncRNA) has been implicated in the development of PC. Recently, long intergenic non-protein coding RNA 1207 (LINC01207) has been reported to regulate the carcinogenesis of multiple cancer types. However, its role in the progression of PC remains to be determined. The aim of the present study was to investigate the expression profile, clinicopathological implication and molecular mechanism of action of LINC01207 in the progression of PC. LINC01207 expression levels were compared between PC tumor and paired normal tissue samples from The Cancer Genome Atlas. The expression of LINC01207 was further analyzed in PC cell lines and a normal prostatic cell line. The role of LINC01207 in proliferation, migration and invasion of PC cells was examined using small interfering RNA-mediated silencing. Western blot analysis was used to investigate the changes in protein levels underlying the mechanism of action of LINC01207. The role of LINC01207 in tumorigenesis was evaluated in a xenograft model. LINC01207 was upregulated in PC tumor samples from TCGA data compared with paired normal tissue. LINC01207 expression was significantly increased in PC cells and tumor tissues compared with in normal prostate cells (RWPE1) and normal prostate tissues, respectively. Furthermore, LINC01207 silencing inhibited PC cell proliferation and colony formation and induced apoptosis. Mechanistic experiments showed that LINC01207 promoted carcinogenesis by sponging miR-1182 to regulate the protein levels of AKT3 in PC cell lines. Thus, the findings of the present study indicated that LINC01207 might play a role in the tumorigenesis of PC and may serve as a therapeutic target for PC treatment.

The androgen receptor\u2014lncRNASAT1-AKT-p15 axis mediates androgen-induced cellular senescence in prostate cancer cells

The bipolar androgen therapy (BAT) to treat prostate cancer (PCa) includes cycles of supraphysiological androgen levels (SAL) under androgen-deprivation therapy (ADT). We showed previously that SAL induces cellular senescence in androgen-sensitive PCa cells and in ex vivo-treated patient PCa tumor samples. Here, we analyzed the underlying molecular pathway and reveal that SAL induces cellular senescence in both, castration-sensitive (CSPC) LNCaP and castration-resistant PCa (CRPC) C4-2 cells through the cell cycle inhibitor p15INK4b and increased phosphorylation of AKT. Treatment with the AKT inhibitor (AKTi) potently inhibited SAL-induced expression of p15INK4b and cellular senescence in both cell lines. Proximity-ligation assays (PLA) combined with high-resolution laser-scanning microscopy indicate that SAL promotes interaction of endogenous androgen receptor (AR) with AKT in the cytoplasm as well as in the nucleus detectable after three days. Transcriptome sequencing (RNA-seq) comparing the SAL-induced transcriptomes of LNCaP with C4-2 cells as well as with AKTi-treated cell transcriptomes revealed landscapes for cell senescence. Interestingly, one of the identified genes is the lncRNASAT1. SAL treatment of native patient tumor samples ex vivo upregulates lncRNASAT1. In PCa tumor tissues, lncRNASAT1 is downregulated compared with nontumor tissues of the same patients. Knockdown indicates that the lncRNASAT1 is crucial for SAL-induced cancer-cell senescence as an upstream factor for pAKT and for p15INK4b. Further, knockdown of lncRNASAT1 enhances cell proliferation by SAL, suggesting that lncRNASAT1 serves as a tumor suppressor at SAL. Interestingly, immunoprecipitation of AR detected lncRNASAT1 as an AR-interacting partner that regulates AR target-gene expression. Similarly, RNA-ChIP experiments revealed the interaction of AR with lncRNASAT1 on chromatin. Thus, we identified a novel AR-lncRNASAT1-AKT-p15INK4b signaling axis to mediate SAL-induced cellular senescence.

Long non-coding RNA SNHG17 enhances the aggressiveness of C4-2 human prostate cancer cells in association with β-catenin signaling.

Long non-coding (lnc) RNAs have emerged as important regulators of cancer development and progression. Several lncRNAs have been reported to be associated with prostate cancer (PCa); however, the involvement of lncRNA SNHG17 in PCa remains unclear. In the present study, the mRNA expression level of SNHG17 in 58 pairs of PCa tumor samples and adjacent non-tumor tissues, as well as in PCa tumor cell lines was analyzed. The regulatory effect of SNHG17 on the oncogenic phenotypes of the C4-2 tumor cell line was also investigated. The clinicopathological analysis revealed that SNHG17 mRNA expression level was increased in the PCa tumor samples, and its high expression levels were associated with poor patient outcomes, indicating that SNHG17 may act as a biomarker for the prognosis of PCa. SNHG17 mRNA expression level was also increased in different PCa tumor cell lines. Functionally, SNHG17 increased C4-2 tumor cell growth and aggressiveness by stimulating tumor cell proliferation, survival, invasion and resistance to chemotherapy. Furthermore, SNHG17 promoted in vivo tumor growth in a xenograft mouse model. Notably, the SNHG17-induced in vitro and in vivo oncogenic effects were associated with activation of the β-catenin pathway. The results from the present study revealed that lncRNA SNHG17 could be an important regulator in the oncogenic properties of human PCa and may; therefore, represent a potential PCa therapeutic target.

Evaluation of Somatostatin and CXCR4 Receptor Expression in a Large Set of Prostate Cancer Samples Using Tissue Microarrays and Well-Characterized Monoclonal Antibodies

BACKGROUND: Prostate cancer (PCa) is the most common type of cancer among men in Western countries. Despite numerous therapeutic options, few treatments are available for patients with end-stage disease. In the present study, different somatostatin receptors (SSTs) and the chemokine receptor CXCR4 were evaluated for their suitability as novel therapeutic targets in PCa. MATERIALS AND METHODS: The expression of SST subtypes 1, 2A, 3, and 5 and of CXCR4 was evaluated in 276 PCa tumor samples on a tissue microarray (TMA) in 23 whole-block tumor samples and in 3 PCa cell lines by immunohistochemistry using well-characterized monoclonal antibodies. RESULTS: Overall, the frequency and intensity of expression of SSTs and CXCR4 were very low among the PCa samples investigated. Specifically, SST5, SST2A, and SST3 were expressed, albeit at low intensity, in 10.5%, 9.1%, and 0.7% of the TMA samples, respectively. None of the TMA samples showed SST1 or CXCR4 expression. Only a single small-cell-type neuroendocrine carcinoma that was coincidentally included among the whole-block samples exhibited strong SST2A, SST5, and CXCR4 and moderate SST3 expression. Independent of the tumor cells, the tumor capillaries in many of the PCa samples were strongly positive for SST2A, SST3, SST5, or CXCR4 expression. SST expression in the tumor cells was associated with advanced tumor grade and stage. CONCLUSION: Overall, SST and CXCR4 expression levels are clearly of no therapeutic relevance in PCa. SST- or CXCR4-based therapy might be feasible, however, in rare cases of small-cell-type neuroendocrine carcinoma of the prostate.

MicroRNA Expression Profiling in Young Prostate Cancer Patients.

MicroRNAs (miRNAs) are small, non-coding RNA molecules with multiple roles in many biological processes. Few studies have shown the molecular characteristics in younger prostate cancer (PCa) patients. In this study, we performed miRNA profiling in young PCa (EO-PCa) cases compared with PCa arising in older men (LO-PCa).Experimental Design: Formalin-fixed, paraffin embedded tissue was used. miRNA was extracted for PCR array and NanoString methods. Relative miRNAs expression levels were obtained by comparing young vs older men, and young PCa tumor samples vs normal epithelium.Results: miRNA profiling showed a different expression pattern in PCa arising in younger men, and young PCa tumoral and its normal counterpart. Nine miRNAs (hsa-miR-140-5p, hsa-miR-146a, hsa-miR-29b, hsa-miR-9, hsa-miR-124-3p, hsa-let-7f-5p, hsa-miR-184, hsa-miR-373, hsa-miR-146b-5p) showed differences in the expression compared to LO-PCa. Fourteen miRNAs were significantly up-regulated (miR-1973, miR-663a, miR-575, miR-93-5p, miR-630, miR-600, miR-494, miR-150-5p, miR-137, miR-25-3p, miR-375, miR-489, miR-888-5p, miR-142-3p), while 9 were found down-regulated (miR-21-5p, miR-363-3p, miR-205-5p, miR-548ai, miR-3195, 145-5p, miR-143-3p, miR-222-3p, miR-221-3p) comparing young PCa tumoral tissue compared to normal counterpart. The higher expression of miR-600 and miR-137 were associated with high Gleason score, extraprostatic extension and lymphatic invasion.Conclusion: These results suggest that PCa in younger patients has a different expression profile compared to normal tissue and PCa arising in older man. Differentially expressed miRNAs provide insights of molecular mechanisms involve in this PCa subtype.

NT5E expression and the immune landscape of prostate cancer (PC): An analysis from The Cancer Genome Atlas database.

e16591 Background: Immune checkpoint inhibitors targeting PD-1/L1 and CTLA-4 pathway have shown modest activity in patients with advanced PC. Additional immunosuppressive mechanisms in the PC tumor microenvironment need to be investigated. Increased CD73 (encoded by NT5E) expression results in generation of immunosuppressive adenosine in the tumor microenvironment and has been associated with metastasis and poor survival in PC. Utilizing the TCGA dataset, we investigated the association of NT5E expression with the immune landscape of PC. Methods: RNA-seq data for 331 PC tumor samples and 51 normal adjacent tissue (NAT) samples was downloaded and log2 transformed. Patients were split into low, intermediate, and high expression groups based on NT5E expression (≤ -1, -1 to 1 and ≥1 standard deviation from the overall mean) in tumor and NAT. A tumor inflammation signature (TIS) reflecting an inflamed tumor phenotype was calculated based on the averaged tumor expression of 18 previously validated genes (Ayers et al, 2017). Abundance of infiltrating immune cell subsets was estimated based on expression of previously identified 782 immune metagenes (Charoentong et al, 2017). Immune cell abundance scores and TIS were compared between NT5E expression groups using the Mann-Whitney U test and the Bonferroni correction was used to control for false discovery rate. Results: NT5E expression in NAT was not associated with the TIS or expression of immune cell marker genes. In contrast, NT5E expression in tumor tissue correlated positively with TIS (P &lt; 0.001). Compared to tumors with low NT5E expression, those in high NT5E expression group had higher expression of central memory CD4+, effector memory CD8+, type 1 helper, NK and regulatory T (Treg) cell markers. Conclusions: In our analysis, NT5E expression correlated with markers of inflamed tumor phenotype in PC. Although NT5E expression was associated with higher CD8+and CD4+ T cells, concurrent increase in Tregs could inhibit the infiltrating lymphocytes and promote tumor growth. Our findings indicate a possible role for the adenosine pathway as a mediator of immunosuppression in PC and a potential therapeutic target. AT and EL: Equal contribution

Abstract 5259: Gene expression array and pathway profiling analyses distinguish HGF/Met pathways driving cell proliferation from invasion and identify events correlated with prostate cancer progression

Abstract Signaling by hepatocyte growth factor (HGF) via its cell surface receptor, Met, drives cell survival, growth and motility, as well as tumor growth and metastasis in several prevalent human cancers. HGF and Met have become highly sought targets for cancer drug development: 165 clinical trials of 21 experimental agents have been completed or are in progress. We reported previously that a selective HGF antagonist failed to block growth of the human prostate adenocarcinoma derived cell line PC3M as primary tumor xenografts in mice, but potently blocked spontaneous PC3M tumor metastasis, as well as cell motility and invasion in vitro. Thus partial activation of the Met pathway in PC3M cells by murine HGF (mHGF) is capable of driving invasion but not proliferation, whereas human HGF (hHGF) is capable of driving both activities. To identify the signaling and gene modulation events critical for Met-driven cell invasion and to distinguish them from Met-driven proliferation, mRNA expression array and pathway profiling analyses of hHGF and mHGF-treated PC3M cells were performed. Ingenuity Pathway Analysis (IPA) of 344 hHGF-specific statistically significant gene modulation events of 2-fold or greater showed significant overlap with cell cycle progression and proliferation pathways, cancer and upstream activation of the cyclin D1 and choriogonadotropin pathways. IPA analysis of 520 gene modulation events associated with motility and invasion showed significant overlap with cell migration and invasion pathways, upstream activation of the MEK/MAPK and mir-155 pathways and upstream inhibition of PI3K and pro-inflammatory cytokine pathways. HGF-specific blockade of spontaneous PC3M metastasis in our model prompted us to further compare significant gene modulation events related to cell invasion with those reported for prostate cancer tumor samples as part of The Cancer Genome Atlas Project (TCGA; MSKCC, 2010; 216 cases). Of 520 altered genes in PC3M, 345 were also interrogated in TCGA: 150 of these (47%) were similarly modulated in prostate cancer patient samples. Twenty-four gene modulation events (7%) were associated with significant change in disease-free survival (DFS) in 88% of cases: 1 gene with increased DFS (logrank p: 0.002747, 56% of cases affected) and 23 with decreased DFS (logrank p: 0.007542; 65% of cases affected). Together these findings identify critical differences in intracellular pathways downstream of HGF/Met interaction leading to cell proliferation vs invasion and reveal that a substantial fraction of prostate cancer patients who show gene modulation events associated with increased tumor cell invasion and metastasis in the PC3M model described here also experience significantly accelerated disease progression. Citation Format: Fabiola Cecchi, Jason Lih, Young Lee, William Walsh, Mickey Williams, Donald P. Bottaro. Gene expression array and pathway profiling analyses distinguish HGF/Met pathways driving cell proliferation from invasion and identify events correlated with prostate cancer progression. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 5259. doi:10.1158/1538-7445.AM2014-5259

Methylation of PITX2, HOXD3, RASSF1 and TDRD1 predicts biochemical recurrence in high-risk prostate cancer.

To explore differential methylation of HAAO, HOXD3, LGALS3, PITX2, RASSF1 and TDRD1 as a molecular tool to predict biochemical recurrence (BCR) in patients with high-risk prostate cancer (PCa). A multiplexed nested methylation-specific PCR was applied to quantify promoter methylation of the selected markers in five cell lines, 42 benign prostatic hyperplasia (BPH) and 71 high-risk PCa tumor samples. Uni- and multivariate Cox regression models were used to assess the importance of the methylation level in predicting BCR. A PCa-specific methylation marker HAAO in combination with HOXD3 and a hypomethylation marker TDRD1 distinguished PCa samples (>90 % of tumor cells each) from BPH with a sensitivity of 0.99 and a specificity of 0.95. High methylation of PITX2, HOXD3 and RASSF1, as well as low methylation of TDRD1, appeared to be significantly associated with a higher risk for BCR (HR 3.96, 3.44, 2.80 and 2.85, correspondingly) after correcting for established risk factors. When DNA methylation was treated as a continuous variable, a two-gene model PITX2 × 0.020677 + HOXD3 × 0.0043132 proved to be the best predictor of BCR (HR 4.85) compared with the individual markers. This finding was confirmed in an independent set of 52 high-risk PCa tumor samples (HR 11.89). Differential promoter methylation of HOXD3, PITX2, RASSF1 and TDRD1 emerges as an independent predictor of BCR in high-risk PCa patients. A two-gene continuous DNA methylation model "PITX2 × 0.020677 + HOXD3 × 0.0043132" is a better predictor of BCR compared with individual markers.

Abstract 4599: Comprehensive molecular oncogenomic profiling &amp; miRNA analysis of prostate cancer

Abstract Background: Comprehensive molecular oncogenomic and microRNA (miRNA) profiling of tumors can provide tumor specific oncogenomic and miRNA signatures which can be useful to improve diagnostic accuracy, refine prognostic and predictive capabilities, and may serve as therapeutic targets. In prostate cancer (PCa) such a comprehensive analysis has not been reported. Design: DNA and RNA obtained from scant amounts of fresh frozen PCa tumor tissue samples (n=36) were profiled by (1) Mutation analysis: Sequenom Massarray &amp; OncoCarta VI panel that profiles 238 common cancer mutations in 19 oncogenes (known predictors of response or resistance to targeted therapies);(2) Whole-genome gene expression Microarrays: Illumina Chip;(3) Single Nucleotide Polymorphisms (SNP) with genome-wide coverage:Illumina Omni microarrays. (4)miRNA analysis was done on RNA from FFPE PCa tumor tissues (n=126) using RT-PCR. Data was statistically analyzed &amp; correlated with clinical &amp; pathologic variables. Results: Massarray analysis identified a MET oncogene mutation, variant T992I, in a 49 year old patient with Gleason score 7 (4+3) tumor. Of the 47,224 genes analyzed by gene expression microarrays, 74 genes were significant predictors of high tumor grade by ordinal regression analysis (p&amp;lt;0.0001). TGIF1 was the most significant gene. Of the 731,442 SNP's analyzed, 638 significantly predicted high tumor grade by logistic regression analysis (p&amp;lt;0.0001). There was significant interaction between gene and SNPs in 531 SNP/gene pairs (p&amp;lt;0.05). Ingenuity Pathway analysis revealed the significant predictor genes (p&amp;lt;0.05) were involved in biological pathways for Gene Expression, Cell Cycle, Cancer,” “Inflammatory Response, Cell Death, Infection Mechanism &amp; Cellular Assembly, Organization, Gene Expression, Cancer. P53 gene was found to be at the center hub of significant predicting pathways. Loss of miR-34a expression was found in PCa tissues consistent with the central role of p53. Conclusions: Using high throughput genomic profiling &amp; miRNA analysis of small amounts of fresh-frozen and FFPE PCa tumor samples, we identified clinically relevant hot spot mutation in MET oncogene and several significant genes &amp; SNPs to predict tumor grade. P53 gene is at the center hub of all significant pathways. Loss of miR-34a was consistent with p53 function in PCa. MET oncogene mutation is a novel finding, not previously reported in PCa against which small molecule inhibitors are under development. These molecular signatures may have a significant clinical impact on improving diagnostic and predictive capabilities &amp; in designing targeted therapies to achieve the goal of personalized medicine. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 4599. doi:1538-7445.AM2012-4599

Abstract 1756: Automated digital analysis of interleukin-6 (IL-6) expression in a prostate cancer (PCa) matched case-control outcome based tissue microarray (TMA) design set

Abstract IL-6 is a multifunctional cytokine that has been involved in modulation of growth and differentiation in several malignant tumors. Studies have shown its role as an important autocrine growth factor for androgen-dependent human prostate cancer in vivo. Serum IL-6 has also been associated with poor prognosis in prostate cancer. We performed a digital analysis of IL-6 immunoreactivity in prostate cancer epithelial cells to determine differences in IL-6 expression between recurrence and non-recurrence groups in a PCa nested case-control cohort. We analyzed an outcome-based TMA obtained from the Cooperative Prostate Cancer Tissue Resource (CPCTR) containing quadruplicate cores (0.6mm core diameter) from 200 pairs of PCa tumor samples (n=400). Cases with PSA recurrence were matched 1:1 with cases without recurrence by race, age, year of surgery, Gleason grade, and pathological stage. All cases had at least five-years follow up. TMA slides were incubated with rabbit polyclonal IL-6 antibody (Abcam) in a 1:600 dilution. Expression levels of IL-6 were assessed by Colocalization Algorithm (ScanScope®, Aperio Corp). Differences in IL-6 intensity between case-control pairs were calculated by Wilcoxon signed rank paired test. Automated data was available for analysis in 149 pairs (n=298). The Wilcoxon signed rank test showed no statistically significant differences in IL-6 intensity between the two groups (p = 0.7). To the best of our knowledge, this is the first study to examine the expression of IL-6 in a large PCa TMA set. Our results revealed IL-6 expression in cancer tissue; however, after statistical analysis, no significant differences were obtained to indicate that IL-6 may be considered as prognostic marker of prostate cancer with biochemical recurrence if cases were first matched by race, age, date of prostatectomy, Gleason score, and stage. In our study we excluded stromal and inflammatory cells IL-6 expression. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 1756.