Biomarkers For Prostate Cancer Progression Research Articles

Abstract 7629: Association between COMT expression and therapeutic efficacy of androgen receptor-axis targeted in prostate cancer

Abstract Background: The enzyme of catechol-O-methyltransferase (COMT) inhibits the proliferation of prostate cancer (PCa). There has been no obvious biomarker that contributes to the selection of a therapeutic agent among new-generation androgen receptor-axis targeted (ARAT) therapy, such as abiraterone (ABI) or enzalutamide (ENZ). We aimed to assess the possibility of using COMT expression as a biomarker for PCa progression and the criteria for selecting ABI or ENZ. Methods: We retrospectively evaluated 60 patients with PCa treated with ABI or ENZ via needle biopsy or radical prostatectomy. Immunostaining of COMT was performed using formalin-fixed, paraffin-embedded blocks obtained from the initial prostate biopsy for diagnosis or prostatectomy. Immunostaining evaluations were scored by immunostaining intensity (0-3) and staining area (0-3), and the total score ≥4 was defined as "high expression" and the total score <4 was defined as "low expression.” The associations between COMT expression levels and clinical outcomes, including the duration of ENZ or ABI response, were also assessed. Results: Of the 60 cases, nine (15%) showed low expression of COMT. Overall survival was significantly shorter in patients with lower COMT expression (hazard ratio [HR] = 0.24, 95% confidence interval [CI] 0.07-0.83, P= 0.024). When ENZ was administered as the first ARAT, progression-free survival (PFS) was significantly different between patients with COMT expression scores <4 and ≥4 (median 5.9 and 23.3 months, respectively). However, when ABI was administered as the first ARAT, there was no significant difference in the PFS of ARAT between COMT expression scores <4 and ≥4. Conclusion: Patients with lower COMT expression have a significantly poorer prognosis for PCa. In addition, PFS after ENZ administration, as the first ARAT, correlated with COMT expression levels. To our knowledge, this is the first report of an association between COMT expression and the duration of ARAT. Citation Format: Shigekatsu Maekawa, Ryo Takata, Ei Shiomi, Daiki Ikarashi, Tomohiko Matsuura, Renpei Kato, Mitsugu Kanehira, Jun Sugimura, Wataru Obara. Association between COMT expression and therapeutic efficacy of androgen receptor-axis targeted in prostate cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 7629.

Extracellular Matrix- and Integrin Adhesion Complexes-Related Genes in the Prognosis of Prostate Cancer Patients' Progression-Free Survival.

Prostate cancer is a heterogeneous disease, and one of the main obstacles in its management is the inability to foresee its course. Therefore, novel biomarkers are needed that will guide the treatment options. The extracellular matrix (ECM) is an important part of the tumor microenvironment that largely influences cell behavior. ECM components are ligands for integrin receptors which are involved in every step of tumor progression. An underlying characteristic of integrin activation and ligation is the formation of integrin adhesion complexes (IACs), intracellular structures that carry information conveyed by integrins. By using The Cancer Genome Atlas data, we show that the expression of ECM- and IACs-related genes is changed in prostate cancer. Moreover, machine learning methods revealed that they are a source of biomarkers for progression-free survival of patients that are stratified according to the Gleason score. Namely, low expression of FMOD and high expression of PTPN2 genes are associated with worse survival of patients with a Gleason score lower than 9. The FMOD gene encodes protein that may play a role in the assembly of the ECM and the PTPN2 gene product is a protein tyrosine phosphatase activated by integrins. Our results suggest potential biomarkers of prostate cancer progression.

Abstract A061: Nuclear lamin content as a biomarker for prostate cancer progression

Abstract Lamins are proteins that help to structure the cellular nucleus via the formation of an intermediate filament weave that grants rigidity to the nuclear membrane. Lamins also tether the chromatin to the nuclear envelope, contributing to the formation of heterochromatin, necessary for adequate gene expression control. The purpose of this study was to use a combination of immunostaining, ChIP-seq, and chromosome conformation capture (Hi-C) to a) characterize the expression and deposition patterns of Lamin A, Lamin B1, and Lamin B2 in cell lines and patient samples, b) to evaluate chromatin associations with the lamina and, c) to characterize chromatin organization phenomena related to lamina conformation. In this study, we used a collection of cells that model the continuum of progression in vitro as follows: RWPE (normal prostate epithelium), LNCaP (adenocarcinoma), VCaP and MDAPCa2a/b (bone metastatic). We also evaluated whether the phenotypes for lamin deposition observed in vitro correlate with that of patient samples, via immunohistochemistry of tissue microarrays. We have identified that Lamin A content is significantly lower in bone metastatic cell lines. While VCaP cells lack Lamin A deposition, MDAPCa2a cells have a heterogeneous distribution: cells that grow in contact with the cell culture surface express Lamin A while cells that grow atop 3D clusters of cells do not. In contrast, Lamin B1 and B2 content is consistent across cell lines. Analysis of tissue microarray immunohistochemistry showed congruent results to the in vitro findings: patient samples derived from higher-grade adenocarcinomas show a decreased number of lamin A positive cells.​ This endogenous lack of Lamin A in VCaP results in an altered lamin-associated domain distribution that can potentially result in abnormal heterochromatin formation, as characterized by ChIP-seq. Further,​through a comprehensive analysis of genome architecture via chromosome conformation capture, we observe a change in the radial positioning of the chromosomes when comparing cells that model normal epithelium, adenocarcinoma, and bone metastasis. Given that the primary metastatic site for prostate cancer is the bone, we evaluated the effect of bioavailable calcium on lamin expression in vitro. Interestingly, we find that in cells cultured on vessels coated in amorphous calcium phosphate, lamin expression is ablated both in normal epithelium and adenocarcinoma cell lines, independent of testosterone levels. Taken together, our results show that lamin content, and in particular loss of lamin A, could be an early predictor of disease progression potential, affecting nucleus mechanics and pliability, ultimately facilitating metastasis. Further, the altered chromatin organization dynamics can potentially act as a prelude for pro-metastatic transcription Citation Format: Rebeca San Martin, Priyojit Das, Sanaz Hossain, Rachel Patton McCord. Nuclear lamin content as a biomarker for prostate cancer progression [abstract]. In: Proceedings of the AACR Special Conference: Advances in Prostate Cancer Research; 2023 Mar 15-18; Denver, Colorado. Philadelphia (PA): AACR; Cancer Res 2023;83(11 Suppl):Abstract nr A061.

Novel plasma exosome biomarkers for prostate cancer progression in co-morbid metabolic disease

Comorbid Type 2 diabetes (T2D), a metabolic complication of obesity, associates with worse cancer outcomes for prostate, breast, head and neck, colorectal and several other solid tumors. However, the molecular mechanisms remain poorly understood. Emerging evidence shows that exosomes carry miRNAs in blood that encode the metabolic status of originating tissues and deliver their cargo to target tissues to modulate expression of critical genes. Exosomal communication potentially connects abnormal metabolism to cancer progression. Here, we hypothesized that T2D plasma exosomes induce epithelial-mesenchymal transition (EMT) and immune checkpoints in prostate cancer cells. We demonstrate that plasma exosomes from subjects with T2D induce EMT features in prostate cancer cells and upregulate the checkpoint genes CD274 and CD155. We demonstrate that specific exosomal miRNAs that are differentially abundant in plasma of T2D adults compared to nondiabetic controls (miR374a-5p, miR-93-5p and let-7b-3p) are delivered to cancer cells, thereby regulating critical target genes. We build on our previous reports showing BRD4 controls migration and dissemination of castration-resistant prostate cancer, and transcription of key EMT genes, to show that T2D exosomes require BRD4 to drive EMT and immune ligand expression. We validate our findings with gene set enrichment analysis of human prostate tumor tissue in TGCA genomic data. These results suggest novel, non-invasive approaches to evaluate and potentially block progression of prostate and other cancers in patients with comorbid T2D.

Prostate cancer disease recurrence after radical prostatectomy is associated with HLA type and local cytomegalovirus immunity.

Prostate cancer is a heterogeneous disease with a need for new prognostic biomarkers. Human leukocyte antigen (HLA) genes are highly polymorphic genes central to antigen presentation to T‐cells. Two alleles, HLA‐A*02:01 and HLA‐A*24:02, have been associated with prognosis in patients diagnosed with de novo metastatic prostate cancer. We leveraged the next‐generation sequenced cohorts CPC‐GENE and TCGA‐PRAD to examine HLA alleles, antiviral T‐cell receptors and prostate cancer disease recurrence after prostatectomy. Carrying HLA‐A*02:01 (111/229; 48% of patients) was independently associated with disease recurrence in patients with low‐intermediate risk prostate cancer. HLA‐A*11 (carried by 42/441; 10% of patients) was independently associated with rapid disease recurrence in patients with high‐risk prostate cancer. Moreover, HLA‐A*02:01 carriers in which anti‐cytomegalovirus T‐cell receptors (CMV‐TCR) were identified in tumors (13/144; 10% of all patients in the cohort) had a higher risk of disease recurrence than CMV‐TCR‐negative patients. These findings suggest that HLA‐type and CMV immunity may be valuable biomarkers for prostate cancer progression.

Abstract 3183: Targeting a myofibroblastic prostate cancer-associated fibroblast subtype through pharmacological inhibition of NADPH oxidase 4

Abstract Recent developments in single cell sequencing have revealed significant heterogeneity in the stromal tumor microenvironment. It is now widely accepted that there are different cancer-associated fibroblast (CAF) subtypes with different functions and effects on tumor progression. Since CAFs are generally considered an emerging therapeutic target, it is crucial to identify those subtypes that are tumor-promoting and to characterize their driver pathways. In this study we describe a population of CAFs in prostate cancer (PCa) that express elevated levels of NADPH oxidase 4 (Nox4) and localize adjacent to tumor foci. We previously showed that Nox4 is essential for TGFβ-mediated differentiation to a myofibroblastic CAF phenotype and that its increased expression is associated with biochemical relapse and reduced survival. Thus, this study aims to investigate whether pharmacological Nox4 inhibition can be used as an adjuvant therapeutic approach in PCa and which molecular pathways are regulated by Nox4 in the tumor microenvironment. Experiments using GKT831, a small molecule Nox1/Nox4 inhibitor with promising effects in clinical trials for fibrotic diseases, so far support its use as a therapeutic target. Most importantly, Nox4 inhibition reduced CAF marker expression in primary prostate CAFs and attenuated the expression of PSA, the key clinical biomarker of PCa progression, in ex vivo cultured human PCa tissue. The translational application of Nox4 inhibition is currently under investigation in vivo using CAF-PCa cell xenografts. To elucidate the molecular mechanisms regulated by Nox4 we performed integrative bioinformatics and functional assays, which revealed that Nox4 regulates CAF adhesion and migration. In addition, we found that Nox4 regulated genes were associated with a YAP signature and the transcription factor TEAD1, a major cofactor of YAP. Ongoing experiments suggest that during adhesion Nox4 signals via oxidation of SHP2, a redox-sensitive phosphatase that has previously been implicated in regulating YAP transcriptional activity. Previous studies have shown that adhesion and mechanotransduction pathways are commonly altered in myofibroblastic CAFs and that they support the formation of a tumor-promoting microenvironment. Our data suggest that Nox4 acts as a central regulator of these key oncogenic pathways and thus represents a promising therapeutic target. Citation Format: Elena Brunner, Lucy Neumann, Elisabeth Damisch, Martin Puhr, Georg Schäfer, Cédric Szyndralewiez, Helmut Klocker, Natalie Sampson. Targeting a myofibroblastic prostate cancer-associated fibroblast subtype through pharmacological inhibition of NADPH oxidase 4 [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 3183.

Novel Plasma Exosome Biomarkers for Prostate Cancer Progression in Co-Morbid Metabolic Disease

Novel Plasma Exosome Biomarkers for Prostate Cancer Progression in Co-Morbid Metabolic Disease

Loss of microRNA-135b Enhances Bone Metastasis in Prostate Cancer and Predicts Aggressiveness in Human Prostate Samples.

Simple SummaryProstate cancer (PCa) is the most prevalent cancer in males worldwide, and it was the fifth leading cause of cancer mortality in this group in 2020. Near 70% of advanced-stage PCa patients will undergo bone metastasis, suffering pathological complications that severely affect patients’ quality of life and probably progress in most cases to lethal PCa. Our main objective was to unveil novel molecules associated with choosing the bone as a metastatic niche. For this purpose, we generated and characterized a cell line with increased tropism to bone. Its molecular analysis has led us to identify factors with a potential role in bone metastasis that could also be used as biomarkers of disease progression. These data help us to understand the mechanisms that increase bone metastasis penetrance of PCa cells and could provide new therapeutic tools in the future for patients with worse prognoses.About 70% of advanced-stage prostate cancer (PCa) patients will experience bone metastasis, which severely affects patients’ quality of life and progresses to lethal PCa in most cases. Hence, understanding the molecular heterogeneity of PCa cell populations and the signaling pathways associated with bone tropism is crucial. For this purpose, we generated an animal model with high penetrance to metastasize to bone using an intracardiac percutaneous injection of PC3 cells to identify PCa metastasis-promoting factors. Using genomic high-throughput analysis we identified a miRNA signature involved in bone metastasis that also presents potential as a biomarker of PCa progression in human samples. In particular, the downregulation of miR-135b favored the incidence of bone metastases by significantly increasing PCa cells’ migratory capacity. Moreover, the PLAG1, JAKMIP2, PDGFA, and VTI1b target genes were identified as potential mediators of miR-135b’s role in the dissemination to bone. In this study, we provide a genomic signature involved in PCa bone growth, contributing to a better understanding of the mechanisms responsible for this process. In the future, our results could ultimately translate into promising new therapeutic targets for the treatment of lethal PCa.

Extracellular Vesicles-Mediated Transfer of miRNA Let-7b from PC3 Cells to Macrophages.

Prostate-derived extracellular vesicles (pEVs) may represent a way to selectively transport cargo molecules from the producing cells to the target cells to allow biological events, both in physiological and pathological circumstances. pEVs cargo participates in the modulation of the inflammatory responses in physiological conditions and during cancer progression. In the present study, we examined the expression levels of miRNA Let-7b, in both precursor and mature forms, in noncancerous and cancerous prostate cell lines, PNT2 and PC3 respectively, and in their extracellular vesicles (EVs) using reverse-transcription quantitative PCR strategies. We showed that miRNA Let-7b was highly expressed in noncancerous cells and strongly decreased in cancerous PC3 cells, while the opposite was observed in the respective EVs, thus supporting the tumor suppressor role of miRNA Let7-b. We also demonstrated that miRNA Let-7b can be transferred to THP-1 cells via EVs, which are known to induce TAM-like polarization. Our results support the view that miRNA Let-7 b, contained in PC3-derived EVs, is associated with the increase in the miRNA Let7-b observed in TAM-like macrophages. Overall, our results indicate that circulating EV-loaded miRNA might be useful biomarkers for prostate cancer progression and might also support a possible use of pEVs as targets for prostate cancer therapy.

Abstract PO-227: DNA methylation as a predictor of aggressive prostate cancer in Puerto Rican men

Abstract Background: Incidence and mortality rates among Hispanic/Latino (H/L) men with prostate cancer (PCa) are almost same as non-Hispanic whites (NHW) men. However, these data may be over-generalized because all H/L subgroups are aggregated into one broad group. Therefore, few studies focused on health disparity of PCa in H/L men. Data from the Puerto Rico (PR) Cancer Registry shows that in men, PCa is the #1 cancer, both in terms of incidence (39.9% of all cancer cases) and mortality (18.3% of all cancer deaths). Recent studies reported that PR men have a higher rate of poor outcomes than NHW regardless of treatment and also after surgical treatment. Further, PR patients had significantly higher PCa specific mortality than non-Hispanic blacks. Although PCa is normally characterized by a slow progression, ~20-30% of cases are associated with an aggressive phenotype associated with metastasis and death. A key molecular feature of this aggressive phenotype is the dysregulation of DNA repair genes.The objective of this pilot study was to investigate epigenetic differences in tumor DNA methylation, between PR and NHW men to identify specific biomarkers for PCa in PR men. Methods: Archived paraffin-embedded (FFPE) blocks of 24 prostate tumor and 24 adjacent normal tissues were collected through the Puerto Rico Biobank. We selected 12 aggressive and 12 indolent cases based on aggressiveness, mainly based on the Gleason scores and clinical stage. Both 24 tumor and 24 normal tissues were measured methylation level using epigenome wide Illumina EPICDNA methylation platform. Results: DNA methylation analysis showed a clear distinction between tumor and normal tissues. In addition, twenty significant differentially methylated genes associated with aggressive disease were identified including: SLC5A8, FGF12, LCP1, TRH, PFKFB3, and LIN28B Six significantly differentially methylated genes associated with aggressive cases. We also identified 27 DNA repair genes, which were differentially methylated (log2 FC > 0.1)) between aggressive and indolent PR cases. 7genes were hypermethylated and 20 genes were hypomethylated. Multiple DNA repair genes were differentially methylated including ATM, ERCC5, XRCC2, XRCC3, and BRCA1. The ancestry analysis for these men showed a distribution where the European ancestry is the more prevalent (64%) followed by West African ancestry (21%) and Indigenous American ancestry (15%). Although our results have to be validated with large independent samples, for the first time, a few potential DNA methylation biomarkers for PCa progression in PR men were identified. The outcomes of these studies could lead to development of better methods for clinicians to stratify PR men with PCa that have high risk of metatastic and lethal disease with an optimal treatment. The aggressive PCa we are studying may be a cancer disparity in the PR population that has not been identified. Supported by grants #: U54 CA163071-07 and U54 CA163068-07. Citation Format: Gilberto Ruiz-Deya, Jamie Matta, Jarline Encarnacion-Medina, Carmen Ortiz-Sanchez, Liang Wang, Anders Berglund, Youngchul Kim, Jong Park. DNA methylation as a predictor of aggressive prostate cancer in Puerto Rican men [abstract]. In: Proceedings of the AACR Virtual Conference: Thirteenth AACR Conference on the Science of Cancer Health Disparities in Racial/Ethnic Minorities and the Medically Underserved; 2020 Oct 2-4. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2020;29(12 Suppl):Abstract nr PO-227.

Molecular tracing of prostate cancer lethality.

Prostate cancer is diagnosed mostly in men over the age of 50 years, and has favorable 5-year survival rates due to early cancer detection and availability of curative surgical management. However, progression to metastasis and emergence of therapeutic resistance are responsible for the majority of prostate cancer mortalities. Recent advancement in sequencing technologies and computational capabilities have improved the ability to organize and analyze large data, thus enabling the identification of novel biomarkers for survival, metastatic progression and patient prognosis. Large-scale sequencing studies have also uncovered genetic and epigenetic signatures associated with prostate cancer molecular subtypes, supporting the development of personalized targeted-therapies. However, the current state of mainstream prostate cancer management does not take full advantage of the personalized diagnostic and treatment modalities available. This review focuses on interrogating biomarkers of prostate cancer progression, including gene signatures that correspond to the acquisition of tumor lethality and those of predictive and prognostic value in progression to advanced disease, and suggest how we can use our knowledge of biomarkers and molecular subtypes to improve patient treatment and survival outcomes.

Epigenetic Regulation of Gfi1 in Endocrine-Related Cancers: a Role Regulating Tumor Growth.

Prostate and breast cancer constitute the most common cancers among men and women worldwide. The aging population is one of the main risk factors for prostate and breast cancer development and accumulating studies link aging with epigenetic changes. Growth factor independence-1 (Gfi1) is a transcriptional repressor with an important role in human malignancies, including leukemia, colorectal carcinoma, and lung cancer, but its role in prostate and breast cancer is unknown. We have found that Gfi1 epigenetic silencing is a common event in prostate and breast cancer. Gfi1 re-expression in prostate and breast cancer cell lines displaying Gfi1 epigenetic silencing decreases cell proliferation, reduced colony formation density, and tumor growth in nude mice xenografts. In addition, we found that Gfi1 repress alpha 1-anti-trypsin (AAT) and alpha 1-anti-chymotrypsin (ACT) expression, two genes with important functions in cancer development, suggesting that Gfi1 silencing promotes tumor growth by increasing AAT and ACT expression in our system. Finally, Gfi1 epigenetic silencing could be a promising biomarker for prostate cancer progression because it is associated with shorter disease-free survival. In conclusion, our findings strongly indicate that Gfi1 epigenetic silencing in prostate and breast cancer could be a crucial step in the development of these two-well characterized endocrine related tumors.

Importance of activated leukocyte cell adhesion molecule (ALCAM) in prostate cancer progression and metastatic dissemination.

Activated Leukocyte Cell Adhesion Molecule (ALCAM) has been linked to the progression of numerous human cancers, where it appears to play a complex role. The current study aims to further assess the importance of ALCAM in prostate cancer and the prognostic potential of serum ALCAM as a biomarker for prostate cancer progression. Here we demonstrate enhanced levels of tissue ALCAM are associated with metastasis. Additionally, elevated serum ALCAM is indicative of progression and poorer patient outlook, and demonstrates comparable prognostic ability to PSA in terms of metastasis and prostate cancer survival. ALCAM suppression enhanced proliferation and invasiveness in PC-3 cells and motility/migration in PC-3 and LNCaP cells. ALCAM suppressed PC-3 cells were generally less responsive to HGF and displayed reduced MET transcript expression. Furthermore a recombinant human ALCAM-Fc chimera was able to inhibit LNCaP cell attachment to HECV and hFOB1.19 cells. Taken together, ALCAM appears to be a promising biomarker for prostate cancer progression, with enhanced serum expression associated with poorer prognosis. Suppression of ALCAM appears to impact cell function and cellular responsiveness to certain micro environmental factors.

Random forest-based modelling to detect biomarkers for prostate cancer progression

BackgroundThe clinical course of prostate cancer (PCa) is highly variable, demanding an individualized approach to therapy. Overtreatment of indolent PCa cases, which likely do not progress to aggressive stages, may be associated with severe side effects and considerable costs. These could be avoided by utilizing robust prognostic markers to guide treatment decisions.ResultsWe present a random forest-based classification model to predict aggressive behaviour of prostate cancer. DNA methylation changes between PCa cases with good or poor prognosis (discovery cohort with n = 70) were used as input. DNA was extracted from formalin-fixed tumour tissue, and genome-wide DNA methylation differences between both groups were assessed using Illumina HumanMethylation450 arrays. For the random forest-based modelling, the discovery cohort was randomly split into a training (80%) and a test set (20%). Our methylation-based classifier demonstrated excellent performance in discriminating prognosis subgroups in the test set (Kaplan-Meier survival analyses with log-rank p value < 0.0001). The area under the receiver operating characteristic curve (AUC) for the sensitivity analysis was 95%. Using the ICGC cohort of early- and late-onset prostate cancer (n = 222) and the TCGA PRAD cohort (n = 477) for external validation, AUCs for sensitivity analyses were 77.1% and 68.7%, respectively. Cancer progression-related DNA hypomethylation was frequently located in ‘partially methylated domains’ (PMDs)—large-scale genomic areas with progressive loss of DNA methylation linked to mitotic cell division. We selected several candidate genes with differential methylation in gene promoter regions for additional validation at the protein expression level by immunohistochemistry in > 12,000 tissue micro-arrayed PCa cases. Loss of ZIC2 protein expression was associated with poor prognosis and correlated with significantly shorter time to biochemical recurrence. The prognostic value of ZIC2 proved to be independent from established clinicopathological variables including Gleason grade, tumour stage, nodal stage and prostate-specific-antigen.ConclusionsOur results highlight the prognostic relevance of methylation loss in PMD regions, as well as of several candidate genes not previously associated with PCa progression. Our robust and externally validated PCa classification model either directly or via protein expression analyses of the identified top-ranked candidate genes will support the clinical management of prostate cancer.

The induction of core pluripotency master regulators in cancers defines poor clinical outcomes and treatment resistance

Stem cell characteristics have been associated with treatment resistance and poor prognosis across many cancer types. The ability to induce and regulate the pathways that sustain these characteristic hallmarks of lethal cancers in a novel in vitro model would greatly enhance our understanding of cancer progression and treatment resistance. In this work, we present such a model, based simply on applying standard pluripotency/embryonic stem cell media alone. Core pluripotency stem cell master regulators (OCT4, SOX2 and NANOG) along with epithelial–mesenchymal transition (EMT) markers (Snail, Slug, vimentin and N-cadherin) were induced in human prostate, breast, lung, bladder, colorectal, and renal cancer cells. RNA sequencing revealed pathways activated by pluripotency inducing culture that were shared across all cancers examined. These pathways highlight a potential core mechanism of treatment resistance. With a focus on prostate cancer, the culture-based induction of core pluripotent stem cell regulators was shown to promote survival in castrate conditions—mimicking first line treatment resistance with hormonal therapies. This acquired phenotype was shown to be mediated through the upregulation of iodothyronine deiodinase DIO2, a critical modulator of the thyroid hormone signalling pathway. Subsequent inhibition of DIO2 was shown to supress expression of prostate specific antigen, the cardinal clinical biomarker of prostate cancer progression and highlighted a novel target for clinical translation in this otherwise fatal disease. This study identifies a new and widely accessible simple preclinical model to recreate and explore underpinning pathways of lethal disease and treatment resistance.

An In Vivo Screen Identifies PYGO2 as a Driver for Metastatic Prostate Cancer

Advanced prostate cancer displays conspicuous chromosomal instability and rampant copy number aberrations, yet the identity of functional drivers resident in many amplicons remain elusive. Here, we implemented a functional genomics approach to identify new oncogenes involved in prostate cancer progression. Through integrated analyses of focal amplicons in large prostate cancer genomic and transcriptomic datasets as well as genes upregulated in metastasis, 276 putative oncogenes were enlisted into an in vivo gain-of-function tumorigenesis screen. Among the top positive hits, we conducted an in-depth functional analysis on Pygopus family PHD finger 2 (PYGO2), located in the amplicon at 1q21.3. PYGO2 overexpression enhances primary tumor growth and local invasion to draining lymph nodes. Conversely, PYGO2 depletion inhibits prostate cancer cell invasion in vitro and progression of primary tumor and metastasis in vivo In clinical samples, PYGO2 upregulation associated with higher Gleason score and metastasis to lymph nodes and bone. Silencing PYGO2 expression in patient-derived xenograft models impairs tumor progression. Finally, PYGO2 is necessary to enhance the transcriptional activation in response to ligand-induced Wnt/β-catenin signaling. Together, our results indicate that PYGO2 functions as a driver oncogene in the 1q21.3 amplicon and may serve as a potential prognostic biomarker and therapeutic target for metastatic prostate cancer.Significance: Amplification/overexpression of PYGO2 may serve as a biomarker for prostate cancer progression and metastasis. Cancer Res; 78(14); 3823-33. ©2018 AACR.

Abstract 2130: Novel ADAM9 variant induces prostate cancer metastasis

Abstract Prostate cancer often progresses from an androgen to castration-refractory prostate cancer and metastasizes to the bone and lymph nodes. However, there is no biomarker to predict the initiation of cancer metastasis. Therefore, it is an unmet need to understand molecules which induce metastasis to replace the prediction by PSA. Previous studies by us demonstrate the elevation of ADAM9 in PCa malignant progression. However, the role of ADAM9 in the tumor microenvironment is still not fully understood. Using laser capture microdissection of prostate tumor and stromal cells, indicating the increased of ADAM9 and reactive oxygen species in tumor-associated stromal cells. These inductions correlated with the increased expression of SOD-2 in tumor-associated stromal cells. Both electron microscope analysis and conditioned medium of stromal cells demonstrated the increased of soluble ADAM9 level in the medium. ELISA analysis of patient serum confirmed the increased of ADAM9 serum levels in prostate cancer patients. PCR and sequencing analysis confirmed a novel soluble ADAM9 (sADAM9v2) with deletion of membrane domain that induces cell migration through the activation of FAK and AKT phosphorylation. Our studies demonstrated the release of sADAM9 in tumor microenvironment correlated with reactive oxygen stress and regulate prostate cancer migration and metastasis. In conclusion, our studies showed that sADAM9 release by cancer-associated stromal cells could be a potential biomarker for prostate cancer progression. Citation Format: Chia-Ling Hsieh, Shian-Ying Sung. Novel ADAM9 variant induces prostate cancer metastasis [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 2130.

Expression of Indoleamine 2,3-Dioxygenase Induced by IFN-γ and TNF-α as Potential Biomarker of Prostate Cancer Progression.

Inflammation has been suggested to play an important role in onset and progression of prostate cancer (PCa). Histological analysis of prostatectomy specimens has revealed focal inflammation in early stage lesions of this malignancy. We addressed the role of inflammatory stimuli in the release of PCa-specific, tumor-derived soluble factors (PCa-TDSFs) already reported to be mediators of PCa morbidity, such as indoleamine 2,3-dioxygenase (IDO) and interleukin (IL)-6. Inflammation-driven production and functions of PCa-TDFSs were tested “in vitro” by stimulating established cell lines (CA-HPV-10 and PC3) with IFN-γ or TNF-α. Expression of genes encoding IDO, IL-6, IFN-γ, TNF-α, and their receptors was investigated in tumor tissues of PCa patients undergoing radical prostatectomy, in comparison with benign prostatic hyperplasia (BPH) specimens. IFN-γ and TNF-α-treatment resulted in the induction of IDO and IL-6 gene expression and release in established cell lines, suggesting that the elicitation of PCa-TDSFs by these cytokines might contribute to progression of cancer into an untreatable phenotype. An analysis based on timing of biochemical recurrence revealed the prognostic value of IDO but not IL-6 gene expression in predicting recurrence-free survival in patients (RFS) with PCa. In addition, a urine-based mRNA biomarker study revealed the diagnostic potential of IDO gene expression in urines of men at risk of PCa development.

Proteomic profiling of exosomes leads to the identification of novel biomarkers for prostate cancer progression

Exosomes are vesicles which have garnered interest due to their diagnostic and therapeutic potential. Isolation of cancer‐derived exosomes is a prerequisite for their better understanding. We have investigated a new biomarker for prostate cancer progression via quantitative proteomics. Exosomes from androgen‐independent PC‐3 and the androgen‐dependent LNCaP prostate cancer cells were isolated by ultracentrifugation. After tryptic digestion, proteomic analyses utilized a nanoLC coupled with an LTQ‐Orbitrap operated in tandem MS (MS/MS) mode. Accurate Mass and Time (AMT) tag approach was employed for peptide identification and quantitation. Proteomic characterization showed that 105 proteins from PC‐3 exosomes were 10‐fold higher than those from LNCap. Validation by Western blotting and qRT‐PCR confirmed a higher abundance of PFKL, NRP1 and MCAM(CD146) in PC‐3 cell exosomes, too, indicating that aggressive prostate cancer exhibit higher levels of adhesion or cohesion proteins. We also show that MCAM (CD146) was strongly associated to PC‐3 mobility in vitro. These data provided that MCAM should be useful as a new candidate biomarker for prostate cancer progression.Support or Funding InformationThis work was supported by Basic Science Research Program through the National Research Foundation of Korea (NRF) (OGM4391711)This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.

Tumor microenvironment promotes prostate cancer cell dissemination via the Akt/mTOR pathway

Metastasis causes high mortality in various malignancies, including prostate cancer (PCa). Accumulating data has suggested that cancer cells spread from the primary tumor to distant sites at early stage, which is characterized by disseminated tumor cells (DTCs). However, lack of direct evidence of partial localized PCa cells occurring epithelial-to-mesenchymal transition (EMT) and disseminating to distant sites (e.g bone marrow). In this study, we used luciferase labeled PCa cells to establish an EMT mouse model and to detect whether DTCs spread into the bone marrow. We observed tumor cells existing in mouse bone marrow when tumor grew subcutaneously at palpable stage. Studies also showed that ex vivo tumor cells exhibited increased proliferative, migratory, invasive and angiogenesis abilities. When compared ex vivo tumor cells with parental cells, hallmarks of EMT including E-cadherin, Vimentin, Snail, and ZO-1 were altered significantly. Specifically, the ex vivo tumor cells showed more mesenchymal properties. Angiogenesis markers, including VEGFR2, VEGFR3, MCP-3, I-TAC, I309, uPAR and GROα, were also increased in the ex vivo tumor cells. Intriguingly, MCP-1 expression was dramatically increased in those cells. Mechanistic analyses indicated that AP1 mediates PCa EMT and the appearance of DTCs via the Akt/mTOR pathway. This study may provide potential therapeutic targets and diagnostic biomarkers of PCa progression and metastasis.