Tissues Of Prostate Cancer Patients Research Articles

Co-expression of Twist and Snai1: predictor of poor prognosis and biomarker of treatment resistance in untreated prostate cancer.

Prostate cancer (PCa) remains one of the most complex tumors in men. The assessment of gene expression is expected to have a profound impact on cancer diagnosis, prognosis, and treatment decisions. The aim of this study was to determine the utility of the epithelial-mesenchymal transition (EMT) transcription factors Twist and Snai1 in the treatment of naïve prostate cancer. We analyzed formalin-fixed paraffin-embedded (FFPE) prostate tissues from 108 PCa patients and 20 control biopsies using real-time quantitative reverse transcription-polymerase chain reaction (RT-qPCR) and 2-ΔΔCtmethods for Twist and Snail gene expression. The expression of Twist and Snai1 mRNA was significantly overexpressed in primary tissues of PCa patients compared with controls using ROC curve. Statistical analysis showed that the mRNAs of these two genes expression Snai1 and Twist were positively correlated with tumor development and prognostic parameters as Gleason score (p < 0.001; r = 0.707) and (p < 0.001; r = 0.627) respectively. The results of Kaplan-Meier analysis showed that mRNA expression of Snai1 and Twist genes expression were significant predictors of poor overall survival (OS) (Log rank p < 0.001) and progression-free survival (PFS) of patients (Log rank p < 0.001). Furthermore, our results showed that the expression of Snai1 and Twist genes expression in primary tissues of PCa patients could predict resistance to androgen deprivation therapy (p < 0.001) and resistance to the acidic drugs abirateroneor enzalutamide (p < 0.001). However, these two transcription factors failed to predict taxanes resistance at the time of diagnosis (p > 0.05). These results suggest that Snai1 and Twist are overexpressed during the onset and progression of PCa malignancies and may be theranostic markers of resistance to ADT, abiraterone, or enzalutamide therapy.

Prostate Cancer Organoids for Tumor Modeling and Drug Screening.

Prostate cancer (PCa) is the second most common malignancy and the fifth leading cause of cancer death in men worldwide. Despite its prevalence, the highly heterogenic PCa has shown difficulty to establish representative cell lines that reflect the diverse phenotypes and different stages of the disease in vitro and hence hard to model in preclinical research. The patient-derived organoid (PDO) technique has emerged as a groundbreaking three-dimensional (3D) tumor modeling platform in cancer research. This versatile assay relies on the unique ability of cancer stem cells (CSCs) to self-organize and differentiate into organ-like mini structures. The PDO culture system allows for the long-term maintenance of cancer cells derived from patient tumor tissues. Moreover, it recapitulates the parental tumor features and serves as a superior preclinical model for in vitro tumor representation and personalized drug screening. Henceforth, PDOs hold great promise in precision medicine for cancer. Herein, we describe the detailed protocol to establish and propagate organoids derived from isolated cell suspensions of PCa patient tissues or cell lines using the 3D semisolid Matrigel™-based hanging-drop method. In addition, we highlight the relevance of PDOs as a tool for evaluating drug efficacy and predicting tumor response in PCa patients.

Exposure of environmental trace elements in prostate cancer patients: A multiple metal analysis

Prostate cancer (PCa) is the second leading cause of cancer-related deaths among men. To elucidate the connection between trace elements (arsenic: As, cadmium: Cd, lead: Pb, chromium: Cr, and nickel: Ni) and the risk of PCa, we analyzed trace element levels in the serum, urine, and tissues of PCa patients, while also examining their smoking status. We correlated these levels with their smoking habits. Notably, levels of Cd (P ≤ 0.05) and As (P ≤ 0.01) were significantly higher in the tumor tissue than in adjacent tissues. No significant differences were observed in the levels of Pb, Cr and Ni. Additionally, urinary Cd levels in 70% and arsenic levels in 2.3% of the PCa cohort were markedly higher than the CDC-reported cutoff (Cd ≤ 0.185 μg/L & As ≤100 μg/L). None displayed elevated levels of urinary Pb, Cr, and Ni. Conversely, in serum samples, the concentration of arsenic exceeded the CDC-determined limit (As ≤1.0 μg/L) in 31.69% of PCa patients. However, only 7.04% of patients had higher serum Cd levels than the CDC standard values (Cd ≤ 0.315 μg/L), while all PCa patients exceeded the Cr CDC limit (Cr ≤ 0.16 μg/L) and the Ni CDC limit (Ni ≤ 0.2 μg/L). On the contrary, no significant differences were observed in serum Pb (Pb ≤ 35.0 μg/L). Our findings establish a positive link between Cd and arsenic tissue concentrations and the risk of PCa. Subsequent studies are essential to determine whether elevated trace element levels pose a risk for the development of prostate carcinogenesis. Interestingly, among the PCa cohort comprising smokers, notably higher Cd levels were observed only in tumor tissues (P ≤ 0.01) and urine (P ≤ 0.05) compared to other elements or in other specimens.

Abstract 171: Prostate cancer organoids from KUCaP patient-derived xenograft(PDX) series enables us to genetic engineering human-derived cellular models

Abstract Introduction and Objectives Cancer organoids are expected to be valuable models that recapitulate intratumor heterogeneity and the phenotypic diversity of the disease ex vivo. However, the establishment rate of prostate cancer (PCa) organoids directly from clinical specimens are still low, and we need to improve. Patient-derived xenograft model (PDX) is widely used as a human-derived in vivo model, but genetic engineering is impossible, limiting its use. We aimed to develop a method to stably grow prostate cancer organoids from PDX and evaluate the feasibility of gene engineering using PDX-derived organoids. Materials and Methods KUCaP PDX series, which were established from castration-resistant prostate cancer patient tissues, were used to establish organoids. Eight organoids from eight models of KUCaP PDX were established and maintained for at least three passages. Organoids were reinjected into immunodeficient mice to establish organoid-derived xenograft (ODX) with 100% efficacy. We compared histopathological and molecular characteristics of primary patient tumors, PDX tumors, organoids, and ODX tumors. We conducted whole exome sequencing and RNA sequencing to assess the genomic profiles across the models. Firefly luciferase was introduced into organoids to show the feasibility of genetic engineering. Results Pathological findings were similar across the models derived from the same patient. WES analysis revealed most of the mutations detected in the matched patient tumors and organoids. Hierarchical clustering of RNA sequencing showed that the primary tumors, PDX tumors, organoids, and ODX tumors derived from the same patient cluster, which indicates that even after clonal selection during the establishment of organoids, the basic molecular feature of the model is maintained (Figure). Firefly luciferase was successfully introduced in seven out of seven tested organoids and imaged the ODX tumors from these organoids in vivo. Conclusions Organoids were established with a high success rate using PDX. Firefly luciferase was successfully introduced, showed the feasibility of genetic engineering using prostate cancer organoids. Matched PDX and organoids of PCa recapitulate the basic molecular features of primary human PCa. PDX-derived organoids of PCa, which enables genetic engineering of human-derived cellular models, which could be a valuable tool to enhance PCa research. Citation Format: Takuro Sunada, Takayuki Goto, Takayuki Sumiyoshi, Akamatsu Shusuke, Takashi Kobayashi. Prostate cancer organoids from KUCaP patient-derived xenograft(PDX) series enables us to genetic engineering human-derived cellular models [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 171.

Novel roles for HMGA2 isoforms in regulating oxidative stress and sensitizing to RSL3-Induced ferroptosis in prostate cancer cells

Oxidative stress is increased in several cancers including prostate cancer, and is currently being exploited in cancer therapy to induce ferroptosis, a novel nonapoptotic form of cell death. High mobility group A2 (HMGA2), a non-histone protein up-regulated in several cancers, can be truncated due to chromosomal rearrangement or alternative splicing of HMGA2 gene. The purpose of this study is to investigate the role of wild-type vs. truncated HMGA2 in prostate cancer (PCa). We analyzed the expression of wild-type vs. truncated HMGA2 and showed that prostate cancer patient tissue and some cell lines expressed increasing amounts of both wild-type and truncated HMGA2 with increasing tumor grade, compared to normal epithelial cells. RNA-Seq analysis of LNCaP prostate cancer cells stably overexpressing wild-type HMGA2 (HMGA2-WT), truncated HMGA2 (HMGA2-TR) or empty vector (Neo) control revealed that HMGA2-TR cells exhibited higher oxidative stress compared to HMGA2-WT or Neo control cells, which was also confirmed by analysis of basal reactive oxygen species (ROS) levels using 2′, 7′-dichlorofluorescin diacetate (DCFDA) dye, the ratio of reduced glutathione/oxidized glutathione (GSH/GSSG) and NADP/NADPH using metabolomics. This was associated with increased sensitivity to RAS-selective lethal 3 (RSL3)-induced ferroptosis that could be antagonized by ferrostatin-1. Additionally, proteomic and immunoprecipitation analyses showed that cytoplasmic HMGA2 protein interacted with Ras GTPase-activating protein-binding protein 1 (G3BP1), a cytoplasmic stress granule protein that responds to oxidative stress, and that G3BP1 transient knockdown increased sensitivity to ferroptosis even further. Endogenous knockdown of HMGA2 or G3BP1 in PC3 cells reduced proliferation which was reversed by ferrostatin-1. In conclusion, we show a novel role for HMGA2 in oxidative stress, particularly the truncated HMGA2, which may be a therapeutic target for ferroptosis-mediated prostate cancer therapy.

Cancer-associated fibroblasts promote malignant phenotypes of prostate cancer cells via autophagy

Dysregulation of autophagy in cancer-associated fibroblasts (CAFs) has been demonstrated to play a role in malignant phenotypes of human tumors. We intended to investigate the function of CAFs autophagy in prostate cancer (PCa). Firstly, CAFs and normal fibroblasts (NFs) were isolated from cancerous and adjacent normal tissues of PCa patients, for the following experimental preparation. In comparison with NFs, CAFs expressed higher levels of the myofibroblast marker ?-smooth muscle actin (?-SMA) and the mesenchymal marker Vimentin. Besides, CAFs possessed a higher autophagic level than NFs. As for malignant phenotypes, PCa cells co-cultured with CAFs-CM showed greater proliferation, migration and invasion capabilities, while these outcomes were obviously abolished by autophagy inhibition with 3-Methyladenine (3-MA). Moreover, silencing of ATG5 in CAFs inhibited fibroblasts autophagic level and suppressed malignant phenotypes of PCa cells, while ATG5 overexpression in NFs exerted opposite effects. Depletion of ATG5 in CAFs inhibited the xenograft tumor growth and lung metastasis of PCa cells. Taken together, our data demonstrated the promotive effect of CAFs on PCa malignant phenotypes through ATG5-dependent autophagy, suggesting a novel mechanism for PCa progression.

NPAS2 promotes aerobic glycolysis and tumor growth in prostate cancer through HIF-1A signaling

BackgroundProstate cancer (PCa), one of the common malignant tumors, is the second leading cause of cancer-related deaths in men. The circadian rhythm plays a critical role in disease. Circadian disturbances are often found in patients with tumors and enable to promote tumor development and accelerate its progression. Accumulating evidence suggests that the core clock gene NPAS2 (neuronal PAS domain-containing protein 2) has been implicated in tumors initiation and progression. However, there are few studies on the association between NPAS2 and prostate cancer. The purpose of this paper is to investigate the impact of NPAS2 on cell growth and glucose metabolism in prostate cancer.MethodsQuantitative real-time PCR (qRT-PCR), immunohistochemical (IHC) staining, western blot, GEO (Gene Expression Omnibus) and CCLE (Cancer Cell Line Encyclopedia) databases were used to analyze the expression of NPAS2 in human PCa tissues and various PCa cell lines. Cell proliferation was assessed using MTS, clonogenic assays, apoptotic analyses, and subcutaneous tumor formation experiments in nude mice. Glucose uptake, lactate production, cellular oxygen consumption rate and medium pH were measured to examine the effect of NPAS2 on glucose metabolism. The relation of NPAS2 and glycolytic genes was analyzed based on TCGA (The Cancer Genome Atlas) database.ResultsOur data showed that NPAS2 expression in prostate cancer patient tissue was elevated compared with that in normal prostate tissue. NPAS2 knockdown inhibited cell proliferation and promoted cell apoptosis in vitro and suppressed tumor growth in a nude mouse model in vivo. NPAS2 knockdown led to glucose uptake and lactate production diminished, oxygen consumption rate and pH elevated. NPAS2 increased HIF-1A (hypoxia-inducible factor-1A) expression, leading to enhanced glycolytic metabolism. There was a positive correlation with the expression of NPAS2 and glycolytic genes, these genes were upregulated with overexpression of NPAS2 while knockdown of NPAS2 led to a lower level.ConclusionNPAS2 is upregulated in prostate cancer and promotes cell survival by promoting glycolysis and inhibiting oxidative phosphorylation in PCa cells.

Early Cell Cultures from Prostate Cancer Tissue Express Tissue Specific Epithelial and Cancer Markers.

Prostate cancer (PCa) is a widespread oncological disease that proceeds in the indolent form in most patients. However, in some cases, the indolent form can transform into aggressive metastatic incurable cancer. The most important task of PCa diagnostics is to search for early markers that can be used for predicting the transition of indolent cancer into its aggressive form. Currently, there are two effective preclinical models to study PCa pathogenesis: patients derived xenografts (PDXs) and patients derived organoids (PDOs). Both models have limitations that restrict their use in research. In this work, we investigated the ability of the primary 2D prostate cell cultures (PCCs) from PCa patients to express epithelial and cancer markers. Early PCCs were formed by epithelial cells that were progressively replaced with the fibroblast-like cells. Early PCCs contained tissue-specific stem cells that could grow in a 3D culture and form PDOs similar to those produced from the prostate tissue. Early PCCs and PDOs derived from the tissues of PCa patients expressed prostate basal and luminal epithelial markers, as well as cancer markers AMACR, TMPRSS2-ERG, and EZH2, the latter being a promising candidate to mark the transition from the indolent to aggressive PCa. We also identified various TMPRSS2-ERG fusion transcripts in PCCs and PDOs, including new chimeric variants resulting from the intra- and interchromosomal translocations. The results suggest that early PCCs derived from cancerous and normal prostate tissues sustain the phenotype of prostate cells and can be used as a preclinical model to study the pathogenesis of PCa.

Abstract C017: Detection of wild-type and truncated HMGA2 in prostate cancer tissues using RNA in situ hybridization

Abstract High mobility group A2 (HMGA2), a non-histone protein, is known to promote epithelial-mesenchymal transition (EMT), which plays a critical role in prostate cancer progression and metastasis. Both full-length HMGA2 (WT-HMGA2) and truncated (lacking the 3’UTR) HMGA2 (TR-HMGA2) isoforms are overexpressed in several cancers such as lung carcinomas, ovarian cancer, breast cancer, and gastric cancer. However, there is no study investigating the expression and differential roles of WT vs truncated HMGA2 isoforms in prostate cancer. Our previous results indicated that the overexpression of HMGA2 in LNCaP cells increased cell viability and migration for both wild-type and truncated HMGA2. Promotion of EMT was observed in wild-type, but not truncated HMGA2. Reactive oxygen species (ROS) levels were increased with truncated HMGA2 more than wild-type HMGA2. Therefore, wild-type and truncated HMGA2 may play different roles on cancer progression and metastasis. The goal of this study is to examine the expression of wild-type vs. truncated HMGA2 in prostate cancer patient tissue. We have developed a way to detect location and expression of wild-type and truncated HMGA2 using RNA in situ hybridization (RISH). The specific probes’ hybridization followed by a serial signal amplification process allows us to locate and quantify the HMGA2 isoforms in Formalin-Fixed Paraffin-Embedded (FFPE) tissue specimens from cancer patients. Several prostate tissue samples and a prostate cancer tissue microarray that includes 35 patients from different races, stages of cancer, and metastasis status was analyzed. Our results showed increased HMGA2 expression (both wild-type and truncated) in several prostate cancer samples with higher stage cancer. We also observed that most wild-type and truncated HMGA2 is located within the nucleus, while some wild-type isoforms were detected within the cytoplasm. We will further quantify the expression levels to examine whether they are associated with tumor stage and/or race. These studies are the first to examine HMGA2 isoform expression and localization in prostate patient tissue and may offer novel therapeutic intervention strategies based on HMGA2 isoform expression. Citation Format: Bor-Jang Hwang, Mojisoluwa Awolowo, Taaliah Campbell, Ohuod Hawsawi, Sharon Harrison, Denise Gibbs, Camille Ragin, Valerie Odero-Marah. Detection of wild-type and truncated HMGA2 in prostate cancer tissues using RNA in situ hybridization [abstract]. In: Proceedings of the 15th AACR Conference on the Science of Cancer Health Disparities in Racial/Ethnic Minorities and the Medically Underserved; 2022 Sep 16-19; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2022;31(1 Suppl):Abstract nr C017.

Early Dynamics of Quantitative SEPT9 and SHOX2 Methylation in Circulating Cell-Free Plasma DNA during Prostate Biopsy for Prostate Cancer Diagnosis.

Simple SummaryThe diagnosis and risk stratification of prostate cancer (PCa) is associated with difficulties for both the examiner and the patient: the tumor burden and the aggressiveness of the tumor should be determined as accurately as possible without putting too much psychological and physical strain on the patient. The aim of the present proof-of-concept study was to investigate the potential and dynamics of quantitative SEPT9 and SHOX2 methylation, two promising validated non-invasive pan-cancer biomarkers, in PCa patient tissue and circulating cell-free DNA (ccfDNA) during prostate biopsy as a diagnostic tool. SEPT9 and SHOX2 were hypermethylated in PCa tissue and allowed discrimination of disease status, tumor stage and grade. In ccfDNA, methylation of both biomarkers allowed discrimination of localized and metastatic disease and increased shortly after prostate biopsy only in PCa patients. Hence, mSEPT9 and mSHOX2 are promising non-invasive measure in PCa evaluation.Background: The methylation status of Septin 9 (SEPT9) and short stature homeobox 2 (SHOX2) in circulating cell-free DNA (ccfDNA) are validated pan-cancer biomarkers. The present proof-of-concept study aimed to investigate the potential and dynamics of quantitative SEPT9 and SHOX2 methylation in prostate cancer (PCa) patient tissue and ccfDNA during prostate biopsy as a diagnostic tool. Methods: The methylation patterns of SEPT9 and SHOX2 in prostate tissue were analyzed using The Cancer Genome Atlas data set (n = 498 PCa and n = 50 normal adjacent prostate tissue (NAT)). Next, dynamic changes of ccfDNA methylation were quantified in prospectively enrolled patients undergoing prostate biopsy (n = 72), local treatment for PCa (n = 7; radical prostatectomy and radiotherapy) as well as systemic treatment for PCa (n = 6; chemotherapy and 177-Lu-PSMA-therapy). Biomarker levels were correlated with clinicopathological parameters. Results: SEPT9 and SHOX2 were hypermethylated in PCa tissue (p < 0.001) and allowed discrimination of PCa and non-tumor prostate tissue (mSEPT9: AUC 0.87, 95%CI [0.82–0.92]; mSHOX2: AUC 0.89, 95%CI 0.84–0.94). SHOX2 methylation and mRNA levels were significantly higher in PCa tissue and increased with tumor stage and grade, as well as in patients suffering from biochemical recurrence following radical prostatectomy. SEPT9 and SHOX2 ccfDNA methylation allowed distinguishing patients with localized and metastatic disease (p < 0.001 for both). In addition, methylation levels increased shortly after prostate biopsy only in patients with PCa (ΔmSEPT9: p < 0.001 and ΔmSHOX2: p = 0.001). Conclusions: The early dynamics of methylated SEPT9 and SHOX2 in ccfDNA allow differentiation between PCa patients and patients without PCa and is a promising marker for tumor monitoring in the metastatic stage to determine tumor burden under systemic therapy.

Identification and Validation of TRIM25 as a Glucose Metabolism Regulator in Prostate Cancer.

Prostate cancer (PCa) malignant progression is accompanied with the reprogramming of glucose metabolism. However, the genes involved in the regulation of glucose metabolism in PCa are not fully understood. Here, we propose a new method, DMRG, which constructs a weighted differential network (W-K-DN) to define the important metabolism-related genes. Based on biological knowledge and prostate cancer transcriptome data, a tripartite motif-containing 25 (TRIM25) was defined using DMRG; TRIM25 was involved in the regulation of glucose metabolism, which was verified by overexpressing or knocking down TRIM25 in PCa cell lines. Differential expression analysis of TCA cycle enzymes revealed that TRIM25 regulated isocitrate dehydrogenase 1 (IDH1) and fumarate hydratase (FH) expression. Moreover, a protein–RNA interaction network of TRIM25 revealed that TRIM25 interacted with RNA-binding proteins, including DExH-box helicase 9 and DEAD-box helicase 5, to play a role in regulating the RNA processing of metabolic enzymes, including IDH1 and FH. Furthermore, TRIM25 expression level was found to be positively correlated with Gleason scores in PCa patient tissues. In conclusion, this study provides a new method to define genes influencing tumor progression, and sheds light on the role of the defined TRIM25 in regulating glucose metabolism and promoting PCa malignancy.

CKAP2L, a crucial target of miR-326, promotes prostate cancer progression

BackgroundThe overexpression of aberrant cell cycle signaling pathway associated protein has been implicated in multiple malignancies and the identification of all-important one among is the crux of the precise targeted therapy. CKAP2L (Cytoskeleton Associated Protein 2 Like) plays a newish role in cancer progression through activation of the process of cell cycle and mitosis. In this study, we aim to delineate the prominent dysregulated expression of CKAP2L and comprehensively reveal its deregulation in prostate cancer. MethodCKAP2L expression was examined in the normal and tumor tissues of prostate cancer patients with RT-QPCR and Western blot. IHC showed the different expression in normal prostate tissue, tissue of BPH, low Gleason Score and high Gleason Score prostate cancer patients. Transwell, colony formation, MTT and flow cytometry were performed to detected the changes in cellular function in vitro. The xenograft model was conducted for the changes in vivo. Dual luciferase and RIP proved the binding relation between CKAP2L and miR-326.ResultsIn multiple datasets, CKAP2L was found upregulated and positively associated with Gleason grade and poor clinical outcomes of patients. shRNA mediated silence of CKAP2L suppressed cell proliferation, impaired monolayer formation, inhibited cell invasion. CKAP2L was confirmed to be the direct target of miR-326, which had a carcinostatic effect by binding the 3’untranslated regions (3’UTRs) of CKAP2L mRNA. The deletion of CKAP2L resulted in reduced expression of genes involved in the mitotic cell cycle such as multiple cyclin-dependent kinases and cyclins, but also several genes encoding proteins involved in chromosome segregation and spindle assembly.ConclusionTaken together, CKAP2L plays a carcinogenic role in prostate cancer by regulates the expression of cycle-associated proteins.

Abstract 113: Investigating the role of high mobility group a2 (HMGA2) truncated isoform in promoting oxidative stress in PCa cells

Abstract Prostate cancer (PCa) is one of the most commonly diagnosed malignancies among men worldwide and remains the second leading cause of cancer related death in the United States. Oxidative stress has been shown to be increase in several cancers including prostate cancer. In fact, oxidative stress in prostate cancer is suggested to be a direct result of cell exposure to reactive oxygen species (ROS). High mobility group A 2 (HMGA2), a non-histone protein, is an oncogene that is up-regulated in several cancers. This protein has ability to undergo chromosomal rearrangement and alternative splicing, causing its full length/wild type HMGA2 (HMGA2-WT) to become the truncated losing its 3’UTR leading to the generation of HMGA2 truncated (HMGA2-TR). We have previously shown HMGA2-WT’s involvement in epithelial mesenchymal transition (EMT), however, the functional role of HMGA2-TR has not yet been dissected. We hypothesize that truncated HMGA2’s involvement with oxidative stress leads to prostate cancer progression. We analyzed the baseline expression of wild-type vs.truncated HMGA2 in prostate patient tissue and cells lines by real-time PCR and western blot analyses. Prostate cancer patient tissue and some cell lines expressed increasing amounts of both wild-type and truncated HMGA2with increasing tumor grade, when compared to normal epithelial cells. RNA-Seq analysis of LNCaP prostate cancer cells stably overexpressing HMGA2-WT, HMGA2-TR, or empty vector (Neo) control revealed thatHMGA2-TR cells display increased oxidative stress compared to HMGA2-WT or Neo control cells. This was also confirmed by analysis of basal reactive oxygen species (ROS) levels, and the ratio of GSH/GSSG andNADP/NADPH utilizing metabolomics. Additionally, proteomic analysis showed that HMGA2-TR protein interacted with several proteins, including a cytoplasmic stress granule protein G3BP1 that responds to oxidative stress. Transient knockdown of G3BP1 increased ROS in HMGA2-TR cells. These studies may therefore uncover novel role for truncated HMGA2 in oxidative stress. Acknowledgements: These studies were supported by the NIH/NIMHD/RCI Grant #5G12MD007590-31,NIH/NIGMS/RISE Grant #5R25GM060414 Citation Format: Taaliah Campbell, Ohuod Hawsawi, Nathan Bowen, Valerie Odero-Marah. Investigating the role of high mobility group a2 (HMGA2) truncated isoform in promoting oxidative stress in PCa cells [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 113.

Distinct expression signatures of miR-130a, miR-301a, miR-454 in formalin fixed paraffin embedded tissue samples of prostate cancer patients

Recent advances in high-throughput screening of human tumors have enabled the identification of numerous tumor markers. However, the clinical utility of these newly identified molecules remains enigmatic until they are well validated in patient samples. Although many long non-coding RNA molecules of clinical importance have been identified in the differential diagnosis of prostate cancer, the consistency of many of them in practice is still controversial. Therefore, short non-coding RNA molecules such as miRNAs are coming to the forefront in the differential diagnosis of the disease because of their stability. Accordingly, in the present study, we aimed to reveal the clinical significance of miR-130a, miR-301a, miR-454 expression levels in formalin fixed paraffin embedded (FFPE) tissue samples of prostate cancer patients. miRNA expression signatures were determined by RT-qPCR method. Notably, we found that miR-301a and miR-454 were significantly upregulated whereas miR-130a were downregulated in cancerous tissues of prostate cancer patients compared to adjacent healthy tissue samples. Moreover, differential expression of these miRNAs was significantly associated with patients' clinicopathological findings, such as Gleason score, lymphovascular invasion, perineural invasion, and extra-prostatic extension. Collectively, our observations indicate that these miRNAs may be of clinical importance in the differential diagnosis of prostate cancer.

Identification of novel prostate cancer genes in patients stratified by Gleason classification: Role of antitumoral genes.

Prostate cancer (PCa) is a tumor with a great heterogeneity, both at a molecular and clinical level. Despite its global good prognosis, cases can vary from indolent to lethal metastatic and scientific efforts are aimed to discern those with worse outcomes. Current prognostic markers, as Gleason score, fall short when it comes to distinguishing these cases. Identification of new early biomarkers to enable a better PCa distinction and classification remains a challenge. In order to identify new genes implicated in PCa progression we conducted several differential gene expression analyses over paired samples comparing primary PCa tissue against healthy prostatic tissue of PCa patients. The results obtained show that this approach is a serious alternative to overcome patient heterogeneity. We were able to identify 250 genes whose expression varies along with tissue differentiation—healthy to tumor tissue, 161 of these genes are described here for the first time to be related to PCa. The further manual curation of these genes allowed to annotate 39 genes with antitumoral activity, 22 of them described for the first time to be related to PCa proliferation and metastasis. These findings could be replicated in different cohorts for most genes. Results obtained considering paired differential expression, functional annotation and replication results point to: CGREF1, UNC5A, C16orf74, LGR6, IGSF1, QPRT and CA14 as possible new early markers in PCa. These genes may prevent the progression of the disease and their expression should be studied in patients with different outcomes.

Reduced DAPK1 Expression Promotes Stem Cell-Like Characteristics of Prostate Cancer Cells by Activating ZEB1 via Hippo/YAP Signaling Pathway.

Prostate cancer (PCa) is a malignant tumor that originates in the male genitourinary system. Downregulation of death-associated protein kinase 1 (DAPK1) is closely related to PCa. Little is known about the functional role of DAPK1 in regulating cancer stem cell (CSC)-like characteristics of PCa cells, and we have conducted research on this topic. Compared with tumor-adjacent normal tissues, DAPK1 was severely downregulated in tumor tissues of PCa patients. DAPK1 expression was also reduced in PCa cell lines with respect to that in normal prostate cells. Moreover, we sorted PCa-CSCs (PCa-CD133+ cells) from PCa cells. PCa-CD133+ cells also exhibited a reduced DAPK1 level and elevated levels of stem cell markers (CD44, OCT4, and SOX2). DAPK1 knockdown promoted sphere formation and enhanced the proportions of PCa-CD133+/PCa-CD133- cells. Inhibition of DAPK1 also accelerated migration and invasion of PCa-CD133+ cells. In addition, DAPK1 interacted with zinc finger E-box-binding homeobox-1 (ZEB1) and repressed ZEB1 expression in PCa-CD133+ cells. DAPK1 suppressed Hippo/YAP signaling pathway by interacting with ZEB1. Finally, we generated a tumor xenograft model to verify the effect of PCa-CD133+ cells following DAPK1 overexpression on tumor growth of PCa. DAPK1 overexpression inhibited tumor growth of PCa and repressed the expression of ZEB1, YAP, and TAZ in the tumor tissues of PCa mice. In conclusion, reduced DAPK1 expression promoted stem cell-like characteristics of PCa cells through activating ZEB1 via Hippo/YAP signaling pathway. Taken together, this work sheds lights on the potential of DAPK1 as a target for PCa therapeutics from bench to clinic.

Long Noncoding RNA NEAT1 as a Potential Candidate Biomarker for Prostate Cancer.

Background: Prostate cancer (PCa) remains one of the leading causes of cancer-related mortality in men worldwide, mainly due to unsatisfactory diagnostic methods used at present, which lead to overdiagnosis, unnecessary biopsies and treatment, or misdiagnosis in early asymptomatic stages. New diagnostic biomarkers are needed for a correct and early diagnosis. Long noncoding RNAs (lncRNAs) have been broadly studied for their involvement in PCa biology, as well as for their potential role as diagnostic biomarkers. Methods: We conducted lncRNA profiling in plasma and microdissected formalin-fixed paraffin-embedded (FFPE) tissues of PCa patients and attempted validation for commonly dysregulated individual lncRNAs. Results: Plasma profiling revealed eight dysregulated lncRNAs, while microarray analysis revealed 717 significantly dysregulated lncRNAs, out of which only nuclear-enriched abundant transcript 1 (NEAT1) was commonly upregulated in plasma samples and FFPE tissues. NEAT1’s individual validation revealed statistically significant upregulation (FC = 2.101, p = 0.009). Receiver operating characteristic (ROC) analysis showed an area under the curve (AUC) value of 0.7298 for NEAT1 (95% CI = 0.5812–0.8785), suggesting a relatively high diagnostic value, thus having a potential biomarker role for this malignancy. Conclusions: We present herein data suggesting that NEAT1 could serve as a diagnostic biomarker for PCa. Additional studies of larger cohorts are needed to confirm our findings, as well as the oncogenic mechanism of NEAT1 in the development of PCa.

Increased Expressions of Matrix Metalloproteinases (MMPs) in Prostate Cancer Tissues of Men with Type 2 Diabetes.

Type 2 diabetes (T2D) is associated with worse prognosis of prostate cancer (PCa). The molecular mechanisms behind this association are still not fully understood. The aim of this study was to identify key factors, which contribute to the more aggressive PCa phenotype in patients with concurrent T2D. Therefore, we investigated benign and PCa tissue of PCa patients with and without diabetes using real time qPCR. Compared to patients without diabetes, patients with T2D showed a decreased E-cadherin/N-cadherin (CDH1/CDH2) ratio in prostate tissue, indicating a switch of epithelial-mesenchymal transition (EMT), which is a pivotal process in carcinogenesis. In addition, the gene expression levels of matrix metalloproteinases (MMPs) and CC chemokine ligands (CCLs) were higher in prostate samples of T2D patients. Next, prostate adenocarcinoma PC3 cells were treated with increasing glucose concentrations to replicate hyperglycemia in vitro. In these cells, high glucose induced expressions of MMPs and CCLs, which showed significant positive associations with the proliferation marker proliferating cell nuclear antigen (PCNA). These results indicate that in prostate tissue of men with T2D, hyperglycemia may induce EMT, increase MMP and CCL gene expressions, which in turn activate invasion and inflammatory processes accelerating the progression of PCa.

Small Molecular Inhibitors Block TRPM4 Currents in Prostate Cancer Cells, with Limited Impact on Cancer Hallmark Functions

Transient receptor potential melastatin 4 (TRPM4) is a broadly expressed Ca2+ activated monovalent cation channel that contributes to the pathophysiology of several diseases.For this study, we generated stable CRISPR/Cas9 TRPM4 knockout (K.O.) cells from the human prostate cancer cell line DU145 and analyzed the cells for changes in cancer hallmark functions. Both TRPM4-K.O. clones demonstrated lower proliferation and viability compared to the parental cells. Migration was also impaired in the TRPM4-K.O. cells. Additionally, analysis of 210 prostate cancer patient tissues demonstrates a positive association between TRPM4 protein expression and local/metastatic progression. Moreover, a decreased adhesion rate was detected in the two K.O. clones compared to DU145 cells.Next, we tested three novel TRPM4 inhibitors with whole-cell patch clamp technique for their potential to block TRPM4 currents. CBA, NBA and LBA partially inhibited TRPM4 currents in DU145 cells. However, none of these inhibitors demonstrated any TRPM4-specific effect in the cellular assays.To evaluate if the observed effect of TRPM4 K.O. on migration, viability, and cell cycle is linked to TRPM4 ion conductivity, we transfected TRPM4-K.O. cells with either TRPM4 wild-type or a dominant-negative mutant, non-permeable to Na+. Our data showed a partial rescue of the viability of cells expressing functional TRPM4, while the pore mutant was not able to rescue this phenotype. For cell cycle distribution, TRPM4 ion conductivity was not essential since TRPM4 wild-type and the pore mutant rescued the phenotype.In conclusion, TRPM4 contributes to viability, migration, cell cycle shift, and adhesion; however, blocking TRPM4 ion conductivity is insufficient to prevent its role in cancer hallmark functions in prostate cancer cells.

Abstract 237: DECR1: The rate limiting enzyme of polyunsaturated fatty acid metabolism and a novel therapeutic target in prostate cancer

Abstract Introduction: Fatty acid oxidation (FAO) is the dominant bioenergetic pathway in prostate cancer (PCa). Previous studies have demonstrated efficacy in targeting key FAO enzymes using in vitro and in vivo models of PCa. However, clinical evidence supporting FAO targeting in PCa is lacking. A recent study reported that FAO is upregulated in PCa cells and is essential for cell viability. Here, we demonstrated therapeutic efficacy of targeting FAO in clinical prostate tumors and identified DECR1 as a potential FAO-related survival factor. Methods and Results: To examine the therapeutic efficacy of targeting FAO in a more clinically-relevant setting, patient-derived prostate explants (PDE) were treated with etomoxir (FAO inhibitor). Results showed significant inhibition of cell proliferation (evaluated using Ki67 immunohistochemistry staining) in drug-treated PDE by a mean of 48% (n=13, p&amp;lt;0.05). To identify key targets of FAO in PCa, a meta-analysis was performed using four clinical RNA-sequencing datasets comprising of malignant and matched normal PCa patient tissues. DECR1 – the rate limiting enzyme of polyunsaturated fatty acid (PUFA) oxidation was identified as a robustly overexpressed FAO gene in PCa tissues; its expression is significantly associated with shorter biochemical recurrence-free survival and overall PCa patient survival. Consistent with the vital role of DECR1 in PUFA oxidation, knockdown of DECR1 impaired the cell's capacity to metabolize PUFAs; furthermore, FAO inhibition via DECR1 knockdown is specific to PUFA oxidation. Notably, DECR1 knockdown significantly inhibited PCa cell proliferation, migration, and invasion, and significantly reduced cellular proliferation in tumors. Mechanistically, DECR1 knockdown results in the induction of lipid peroxidation and cell death via ferroptosis in PCa cells. In contrast, overexpression of DECR1 significantly decreased mitochondrial oxidative stress and reduced levels of malondialdehyde. Treatment of PCa cells with ferrostatin successfully rescued PCa cells from death by DECR1 inhibition. Taken together, these data suggest that overexpression of DECR1 may offer PCa cells a survival advantage by protecting the cells from ferroptosis. Conclusion: This study demonstrated for the first time clinically-relevant evidence that targeting FAO is efficacious and provides evidence for the importance of FAO, and specifically PUFA oxidation, in PCa progression. Importantly, this study identified DECR1 as a promising and novel therapeutic target for PCa. Citation Format: Chui Yan Mah, Zeyad D. Nassar, Ingrid J. Burvenich, Swati Irani, Margaret M. Centenera, Max Moldovan, David J. Lynn, Andrew J. Hoy, Johannes V. Swinnen, Lisa M. Butler. DECR1: The rate limiting enzyme of polyunsaturated fatty acid metabolism and a novel therapeutic target in prostate cancer [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 237.