Prostate Epithelial Cells Research Articles

Preparation of Diosgenin-Functionalized Gold Nanoparticles: From Synthesis to Antitumor Activities

Cancer ranks among the top causes of illness and death globally. Nanotechnology holds considerable promise for enhancing the effectiveness of therapeutic and diagnostic approaches in cancer treatment. Our study presents a promising strategy for applying thiocompound nanomedicine in cancer therapy. Our first study aimed to investigate the biological properties of a new compound thiodiosgenin (TDG)—a new derivative of diosgenin—a natural compound with known antioxidant and anticancer properties. Our current second study aimed to compare the therapeutic efficacy of a new diosgenin—functionalized gold nanoparticles—with its precursor on prostate cancer (DU-145) cell lines. Moreover, the safety of the new thio-derivative and new conjugates was tested against the human epithelial line PNT-2. New advanced analytical techniques were developed for the characterization of nanomaterials using methods such as SP-ICP-MS, UV-Vis, TEM, NMR, FT-IR ELS, and TGA. Our synthetic approach was based, on the one hand, on the ligand exchange of citrates to thiodiosgenin (TDG) on gold nanoparticles, and on the other hand, on the attachment of DG through an ester bond to the linker, which was 3-mercaptopropionic acid (MPA) on gold nanoparticles. Initial in vitro studies indicate that TDG shows greater cytotoxic effects on cancer cells but poses risks to normal prostate epithelial cells (PNT-2). It was demonstrated that all the conjugates produced exhibited significant cytotoxic effects against cancer cells while being less harmful to normal prostate epithelial cells (PNT-2) compared to TDG itself. All the obtained conjugates showed antitumor properties; however, for targeted transport, the system referred to as AuNPs-MPAm1-DG is promising, due to the size of the nanoparticles of 53 nm, zeta potential of -30 mV, and loading content of 27.6%. New methods for synthesizing conjugates with diosgenin were developed and optimized for medical applications. Advanced new analytical methodologies were developed to characterize new conjugates, particularly the use of SP-ICP-MS, to solve existing differences in the shape and morphology of the surface of new conjugates.

P53-loss induced prostatic epithelial cell plasticity and invasion is driven by a crosstalk with the tumor microenvironment

Prostate cancer is a heterogeneous disease with a slow progression and a highly variable clinical outcome. The tumor suppressor genes PTEN and TP53 are frequently mutated in prostate cancer and are predictive of early metastatic dissemination and unfavorable patient outcomes. The progression of solid tumors to metastasis is often associated with increased cell plasticity, but the complex events underlying TP53-loss-induced disease aggressiveness remain incompletely understood. Using genetically engineered mice, we show that Trp53 deficiency in Pten-null prostatic epithelial cells (PECs) does not impact early cell proliferation and neoplasia formation, nor growth arrest and senescence entry at a later time. However, Trp53-deficiency enhances invasive adenocarcinoma development and promotes metastatic cell dissemination. Importantly, our single-cell transcriptomic and chromatin accessibility analyses combined with histological examinations uncovered an epithelial cell population characterized by an induction of Jak/Stat3 signaling and displaying mesenchymal features. Moreover, we show that the transcriptomic signature of this cell population is prominent in tumors of patients with high-risk prostate cancer or metastatic disease. In addition, our in vivo and organoid-based experiments provide evidence that PEC plasticity occurs through bi-directional communication with cancer-associated fibroblasts (CAFs). Thus, our study demonstrates that p53 loss induces a protumorigenic crosstalk between PECs and CAFs, and identifies new vulnerabilities that might be targeted to limit cancer progression.

Clinical significance of stratifying prostate cancer patients through specific circulating genes.

Patient stratification remains a challenge for optimal treatment of prostate cancer (PCa). This clinical heterogeneity implies intra-tumoural heterogeneity, with different prostate epithelial cell subtypes not all targeted by current treatments. We reported that such cell subtypes are traceable in liquid biopsies through representative transcripts. Expanding on this concept, we included 57 genes representing cell subtypes, drug targets and relevant to resistance as non-invasive biomarkers for stratification. This panel was tested by RT-qPCR (quantitative reverse transcription polymerase chain reaction) in blood of controls and different categories of PCa patients. Overall, circulating transcripts showed predictive value throughout the disease. Those with aggressive pathological features such as intra-ductal carcinoma at diagnosis showed more genes over-expressed. In metastatic patients, signatures of subtypes or resistance were associated with treatments, progression-free survival and overall survival. Altogether, testing markers of cell diversity, an intrinsic feature of tumours, and drug targets via liquid biopsies represents a valuable means to stratify patients and predict responses to current or new therapeutic modalities. Over-expressed drug target genes suggest potential benefit from targeted treatments, justifying new clinical trials to offer patient-tailored strategies to eventually impact on PCa mortality.

Meta-analyses of mouse and human prostate single-cell transcriptomes reveal widespread epithelial plasticity in tissue regression, regeneration, and cancer

BackgroundDespite extensive analysis, the dynamic changes in prostate epithelial cell states during tissue homeostasis as well as tumor initiation and progression have been poorly characterized. However, recent advances in single-cell RNA-sequencing (scRNA-seq) technology have greatly facilitated studies of cell states and plasticity in tissue maintenance and cancer, including in the prostate.MethodsWe have performed meta-analyses of new and previously published scRNA-seq datasets for mouse and human prostate tissues to identify and compare cell populations across datasets in a uniform manner. Using random matrix theory to denoise datasets, we have established reference cell type classifications for the normal mouse and human prostate and have used optimal transport to compare the cross-species transcriptomic similarities of epithelial cell populations. In addition, we have integrated analyses of single-cell transcriptomic states with copy number variants to elucidate transcriptional programs in epithelial cells during human prostate cancer progression.ResultsOur analyses demonstrate transcriptomic similarities between epithelial cell states in the normal prostate, in the regressed prostate after androgen-deprivation, and in primary prostate tumors. During regression in the mouse prostate, all epithelial cells shift their expression profiles toward a proximal periurethral (PrU) state, demonstrating an androgen-dependent plasticity that is restored to normal during androgen restoration and gland regeneration. In the human prostate, we find substantial rewiring of transcriptional programs across epithelial cell types in benign prostate hyperplasia and treatment-naïve prostate cancer. Notably, we detect copy number variants predominantly within luminal acinar cells in prostate tumors, suggesting a bias in their cell type of origin, as well as a larger field of transcriptomic alterations in non-tumor cells. Finally, we observe that luminal acinar tumor cells in treatment-naïve prostate cancer display heterogeneous androgen receptor (AR) signaling activity, including a split between AR-positive and AR-low profiles with similarity to PrU-like states.ConclusionsTaken together, our analyses of cellular heterogeneity and plasticity provide important translational insights into the origin and treatment response of prostate cancer. In particular, the identification of AR-low tumor populations suggests that castration-resistance and predisposition to neuroendocrine differentiation may be pre-existing properties in treatment-naïve primary tumors that are selected for by androgen-deprivation therapies.

Pharmacological Properties of Platycarpha glomerata Extracts-A Plant Used to Treat and Manage Elephantiasis.

Platycarpha glomerata (Thunb.) Less. has recently become a plant species of interest to researchers due to its biological activities and less toxic effects. Therefore, the aim of the study is to evaluate the in vitro anticancer potential and phytochemical constituents of P. glomerata plant extracts. Phytochemical screening and FTIR were carried out using standard methods. The antioxidant activity was accessed by determining its ability to scavenge the DPPH radical and nitric oxide radical, whereas the anticancer activity against prostate (DU-145 and PC-3), human T-lymphocyte (SKU-T), gastric adenocarcinoma (AGS), and human prostatic epithelial (PNTA1) cell line was evaluated using the MTT assay. The phytochemical analysis revealed the presence of tannins, flavonoids, saponins, steroids, terpenoids, and cardiac glycosides. The FTIR spectrum for the aqueous extract displayed characteristic peaks for O-H, C=O, C=C, and =C-H stretch. The aqueous ethanol and methanol extracts showed significant dose-dependent DPPH radical scavenging capacity. The aqueous, ethanol, and methanol extracts showed minimum NO scavenging activity of 4.3%, 9.6%, and 11.7% at 2500 µg/mL. The water extract demonstrated good activity against S. aureus, E. coli, and B. pumilus with an MIC of 0.195 mg/mL. The ethanol and methanol extracts significantly reduced the percentage proliferation of DU-145, PC-3, and SKU-T cells at 100 μg/mL. These extracts demonstrated strong dose-dependent DPPH and NO scavenging and antibacterial and cell proliferation inhibition activities. The strong bioactivity of P. glomerata makes it a good candidate for the isolation and identification of active compounds for anticancer and related illnesses.

Location and Movement of the Oxytocin Receptor Differ Between the Normal and Diseased Prostate.

In normal prostate cells, receptors for oxytocin (OT), a peptide involved in regulating prostate growth are sequestered within membrane microdomains called caveolae. During cancer progression, polymerase-transcript-release factor (PTRF) is downregulated, caveolae structures are lost and receptors move onto the cell membrane. This study investigated whether proteins responsible for caveolae formation were affected by the OT peptide, also, how OT treatment affected oxytocin receptor (OTR) movement within living cells. Normal human prostate epithelial cells (PrEC) expressing caveolin and PTRF and androgen-independent (PC3) cancer cells expressing caveolin but not PTRF were used. OTR, caveolin and PTRF expression was determined in human prostate tissue. PTRF expression decreased in tissue alongside an increase in malignancy. Caveolin-1 expression was downregulated by OT treatment. Caveolin-2 was decreased by OT in PrEC cells but increased in PC3 cells. PTRF was decreased by OT in PrEC. TIRF microscopy showed OTR translocated from caveolae to caveolae in normal cells, whereas OTR moved without restraint in malignant cells, possibly stimulating signaling pathways. This study provides evidence for the ability of OT to regulate caveolin and PTRF expression. This study elucidates possible mechanisms by which cell receptors and caveolae proteins interact to enhance cell proliferation.

Temporally and Spatially Controlled Age-Related Prostate Cancer Model in Mice.

The initiation and progression of prostate cancer (PCa) are associated with aging. In the history of age-related PCa research, mice have become a more popular animal model option than any other species due to their short lifespan and rapid reproduction. However, PCa in mice is usually induced at a relatively young age, while it spontaneously develops in humans at an older age. Thus, it is essential to develop a method by which the PCa initiation and progression timeline can be strictly controlled to mimic human physiological conditions. One milestone in this field was the identification of the prostate-specific transcription factor, Probasin (Pb), which allowed for the prostate-specific expression of genes knocked into the mice's genome. Another milestone is the establishment of the preclinical mouse model with Pten conditionally knocked out in the prostate tissue, which closely mimics the formation and growth of human PCa. Hereby, we present the prostate-specific temporally and spatially controlled Pten knockout PCa mouse model that can be induced using an adenovirus-based Cre-LoxP system. The Cre recombinase (Cre) is inserted into an adenovirus vector. Unlike Pb-Cre knock-in models (which are spatially but not temporally controlled), the expression of Cre is activated to knock out Pten from the mice's prostate epithelial cells once injected. The viral delivery procedures strictly control the location and time of Pten knockout. This novel approach provides a powerful age-related murine model for PCa, emphasizing the effect of aging on prostate carcinogenesis. Key features • In vivo delivery of Cre recombinase adenovirus (Ad-Cre-Luc) in Pten LoxP/LoxP (L/L) mice. • Generation of Cre-expressing Ad-Cre-Luc-mediated ablation of Pten in anterior prostate epithelial cells of adult Pten L/L mice at different ages. • The Ad-Cre-Luc-mediated ablation of Pten leads to hyperplasia that progresses through prostatic intraepithelial neoplasia (PIN) to adenocarcinoma. • PIN refers to the non-cancerous growth of epithelial cells in the prostate tissue-not cancer but a precursor of prostate cancer [1].

Synthesis of multifunctional zinc(II) phthalocyanine and evaluation of in vitro cytotoxic activity for potential photodynamic therapy and targeting efficiency in prostate cancer

In this study, we aimed to synthesize a novel biotin-functionalized star-shaped poly(2-ethyl-2-oxazoline) (PEtOx) polymer with a zinc (II) phthalocyanine core (ZnPc-[PEtOx]4-Biotin) to enhance therapeutic efficacy through active targetability. ZnPc-[PEtOx]4 was prepared via cationic ring-opening polymerization, followed by conjugation to biotin and BODIPY using "click chemistry." The resulting Zn (II) phthalocyanine-functionalized polymer was characterized using GPC, FTIR, UV-vis, NMR, and fluorescence spectroscopy. ZnPc-[PEtOx]4-Biotin demonstrated an active targeting effect on prostate cancer cells (22Rv1, LNCaP, and PC-3), with higher affinity compared to in vitro cytotoxicity analysis against normal prostate epithelial cells, PNT1A, and prostate cancer cells (22Rv1, LNCaP, and PC-3) revealed low cytotoxicity, dependent on concentration. These findings suggest that the developed Zn(II) phthalocyanine-functionalized polymeric photosensitizer holds promise as an effective strategy for prostate cancer therapy, leveraging specific target recognition mechanisms.

Abstract C033: Identifying and targeting prostate cancer therapy resistance mechanisms driven by the tumor microenvironment

Abstract Background: Prostate cancer is a prevalent malignancy in men, with treatment resistance posing a significant challenge to successful cure. Acquired Resistance to Therapy (ART) arises from two main components: (1) Tumor Microenvironment (TME) and (2) mutations or epigenetic changes at gene level within the tumor cells themselves. While most cancer therapies target the intrinsic biology of cancer cells, growing evidence indicates that these treatments can also harm the stromal cells within TME, potentially driving ART. The biology of ART may vary based on the types of treatments, cell types, and organ locations. Thus, this study aims to dissect ART components driven by TME-mediated cellular processes in a comprehensive manner. Hypothesis: We propose that cancer therapies induce stress responses in non-cancerous cells within the TME. These stress responses involve the secretion of cytokines, mediators, and growth factors, which we term Stress Response Secretory Programs (SRSPs). We further hypothesize that targeting SRSPs could overcome ART that helps to improve treatment specificity and efficacy. Materials and Methods: We employed comprehensive single-cell profiling of common metastatic sites included liver, prostate, lung, bone, lymph node and spleen in preclinical models to identify secreted proteins and dysregulated pathways caused by genotoxic therapies. In vitro, we evaluated treatment resistance in murine prostate epithelial cell lines (Myc-CAP) by exposing them to conditioned media (CM) from irradiated murine fibroblasts (F4M2), using cell growth assays. Results: Single-cell RNA sequencing of organ samples revealed significant expressions of SRSPs and increased inflammatory responses in liver and prostate fibroblasts as well as other stromal cells treated with carboplatin. In vitro, CM from irradiated F4M2 cells enhanced cell proliferation and survival of Myc-CAP cells in response to docetaxel treatment. Conclusion: Our findings highlight the crucial role of SRSPs in mediating ART through interactions within the TME, which alter tumor cell phenotypes. Targeting these SRSPs holds potential for overcoming treatment resistance and improving therapeutic outcomes, underscoring the need to consider TME complexity in cancer treatment strategies. Citation Format: Tony Lok Heng Chu, Armand Bankhead, Ilsa Coleman, Sander Frank, Peter S. Nelson, Tarana Arman. Identifying and targeting prostate cancer therapy resistance mechanisms driven by the tumor microenvironment [abstract]. In: Proceedings of the AACR Special Conference in Cancer Research: Tumor-body Interactions: The Roles of Micro- and Macroenvironment in Cancer; 2024 Nov 17-20; Boston, MA. Philadelphia (PA): AACR; Cancer Res 2024;84(22_Suppl):Abstract nr C033.

Effect of Soy Isoflavone on Prostate Cancer Cell Apoptosis Through Inhibition of STAT3, ERK, and AKT.

Genistein, an isoflavone found in soybeans, exhibits antioxidant, anti-inflammatory, and anticancer properties. This study explored the molecular mechanisms behind genistein's anticancer effects in prostate cancer DU145 cells. In this study, genistein decreased cell viability, increased annexin V-PE(+) cells, and enhanced the sub-G0/G1 peak by flow cytometric analysis. Increased reactive oxygen species increased mitochondrial depolarization indicating mitochondrial dysfunction and inhibition of ATP formation were also observed in genistein-treated DU145 cells. Genistein upregulated p53 at the mRNA and protein levels and increased caspase-3/7 activity along with the cleavage of Bax, procaspase-3, and PARP. With the increasing genistein concentrations, the percentage of cells in the sub-G0/G1 peak and G2/M phase increased, which was inhibited by treatment with the pan-caspase inhibitor Z-VAD together with 100 μM genistein, which had little toxicity to normal prostate epithelial HPrEC cells. Genistein treatment simultaneously inhibited the activation of STAT3 and other closely related oncogenic kinases such as AKT and ERK and p38 and decreased VEGF expression. Taken together, these results suggest that genistein inhibits the growth of DU145 cells and induces apoptosis by inhibiting STAT3, AKT, ERK, and p38 which provides a molecular basis for the anticancer activity of genistein and suggests its potential as a valuable therapeutic candidate for prostate cancer.

Cell-autonomous IL6ST activation suppresses prostate cancer development via STAT3/ARF/p53-driven senescence and confers an immune-active tumor microenvironment

BackgroundProstate cancer ranks as the second most frequently diagnosed cancer in men worldwide. Recent research highlights the crucial roles IL6ST-mediated signaling pathways play in the development and progression of various cancers, particularly through hyperactivated STAT3 signaling. However, the molecular programs mediated by IL6ST/STAT3 in prostate cancer are poorly understood.MethodsTo investigate the role of IL6ST signaling, we constitutively activated IL6ST signaling in the prostate epithelium of a Pten-deficient prostate cancer mouse model in vivo and examined IL6ST expression in large cohorts of prostate cancer patients. We complemented these data with in-depth transcriptomic and multiplex histopathological analyses.ResultsGenetic cell-autonomous activation of the IL6ST receptor in prostate epithelial cells triggers active STAT3 signaling and significantly reduces tumor growth in vivo. Mechanistically, genetic activation of IL6ST signaling mediates senescence via the STAT3/ARF/p53 axis and recruitment of cytotoxic T-cells, ultimately impeding tumor progression. In prostate cancer patients, high IL6ST mRNA expression levels correlate with better recurrence-free survival, increased senescence signals and a transition from an immune-cold to an immune-hot tumor.ConclusionsOur findings demonstrate a context-dependent role of IL6ST/STAT3 in carcinogenesis and a tumor-suppressive function in prostate cancer development by inducing senescence and immune cell attraction. We challenge the prevailing concept of blocking IL6ST/STAT3 signaling as a functional prostate cancer treatment and instead propose cell-autonomous IL6ST activation as a novel therapeutic strategy.

Development of a Novel Risk Signature for Predicting the Prognosis and Immunotherapeutic Response of Prostate Cancer by Integrating Ferroptosis and Immune-Related Genes.

Ferroptosis and immune response correlation studies have not been reported in prostate cancer (PCa), and the main goal of this paper is to identify biomarkers that can be used for early diagnosis of prostate cancer. Data on PCa were retrieved from the TCGA and MSKCC2010 databases. Thereafter, the differentially expressed ferroptosis-related genes (DE-FRGs: ACSF2) and immune-related genes (DE-IRGs: ANGPT1, NPPC, and PTGDS) were identified using the "limma" package. Additionally, we used univariate and multivariate Cox regression analyses to obtain biochemical relapse (BCR)-free survival-related genes and construct a risk signature. Patients with high-risk scores were characterized by poor BCR-free survival, relatively low immune cell abundance, and comparably weak expression of immune checkpoint molecules. Moreover, gene set variation analysis (GSVA) was performed to explore the biological pathways related to the risk signature. Single sample gene set enrichment analysis (ssGESA) was applied to evaluate the status of immune cells in patients with PCa, which demonstrated that the risk score was intimately affiliated with immune response and cancer pathways. Ultimately, the connection between the risk score and response of PCa patients to immunotherapy was appraised using the TIDE algorithm. The TIDE algorithm implied that the high-risk score PCa population might benefit more from immunotherapy regimens. Finally, qRT-PCR were used to evaluate the expression of DE-FRGs and DE-IRGs in PCa cell and normal prostate epithelial cells. The result of qRT-PCR showed that the mRNA expression levels of ACSF2, ANGPT1, NPPC, and PTGDS in normal prostate epithelial cell were higher than that in PCa cells. Therefore, a risk score model was generated based on one DE-FRG and three DE-IRGs, which could predict the BCR-free survival and response of immunotherapy for patients with PCa.

Mode of action exploration for prostate epithelial cell injury caused by bisphenol A

Bisphenol A (BPA) is a typical food chemical contaminant with various detrimental effects, especially on reproductive system. Male prostate damage is also one of its major adverse health effects, of which mode of action (MOA) remains unclear. This study aims to explore the MOA for prostate toxicity of BPA using human normal prostate epithelial cell RWPE-1 for 28-day human-relevant-level exposure. A physiological based pharmacokinetic model was used to determine the concentration of BPA based on the actual oral exposure in China. The possible key events were identified by high-throughput transcriptome sequencing and validated by qPCR, Western blot and cell cycle assay, and the benchmark concentration analysis were conducted. The enriched KEGG pathways include the endocytosis, cell cycle, cellular senescence, MAPK and TNF signaling pathways. With increasing BPA concentrations, the increased mRNA and/or protein expressions of MAPKAPK2, c-JUN and c-fos in the MAPK signaling pathway, the increased mRNA expressions of CCND1 and CDKN1A, the decreased mRNA expression of CDC25C, the increased proportion of G0/G1 phase and S phase, as well as the decreased proportion of G2/M phase, were observed. The lowest value of benchmark concentration lower confidence limit (BMCL) was retrieved from G2/M phase ratio, with 110.580 and 175.862 nM for BMCL5 and BMCL10, respectively, much higher than the male gonad maximum concentration of 0.019 nM of BPA at the current exposure level of adult Chinese males. In conclusion, the MOA of BPA induced male prostatic toxicity at human-relevant levels may include: key event (KE)1-MAPK signaling pathway activation, KE2-disorder of cell cycle regulatory gene expression (increased expression of CCND1 and CDKN1A, decreased expression of CDC25C), and KE3-disturbance of cell cycle (increased proportion of G0/G1 and S phases, decreased proportion of G2/M phases). However, more studies are needed to validate and complete the MOA.

Effect of Picriafel-terrae Merr. leaves extract on VEGF, Interleukin-6, Prostate Index, and Histopathology in Obesity Rats with Benign Prostate Hyperplasia

Benign prostate hyperplasia (BPH) is a life-threatening condition that primarily affects geriatric patients, with obesity serving as a major risk factor. Several studies have also reported the role of obesity as a risk factor for other chronic non-communicable diseases, such as cardiovascular disease and type 2 diabetes. Therefore, this study aims to investigate the effect of Picriafel-terrae Merr (PF) leaf extract on rat-induced obesity and BPH. The sample population comprised male Wistar rats, which were randomly divided into 5 different groups. Group 1 (G1) served as the normal, Group 2 (G2) was the negative control consisting of obese rats with BPH and treated with PF extract, while Group 3 (G3) was the positive control administered 1 mg/kg BW finasteride. In addition, Groups 4 (G4) and 5 (G5) were administered PF extract at varying doses of 100 mg/kg BW and 200 mg/kg BW, respectively. During the experiment, the test rats received subcutaneous injections of 10 mg/kg BW testosterone for 4 weeks, followed by a high-fat diet for 12 weeks and oral administration of PF extract for 10 days. The prostate index was then calculated and examined histopathologically, followed by ELISA for the detection of interleukin-6 and Vascular Endothelial Growth Factor (VEGF). The results showed a statistically significant increase in interleukin-6 levels (p=0.024), prostate index scores (p<0.001), and histopathological examination of the prostate epithelial and stromal cells (p<0.001). However, VEGF levels were not affected by the administration of PF extract (p=0.274). Based on these results, PF extract could reduce the prostate index markers and prostate histopathology in obese Wistar rats with BPH.

Cancer cell-selective induction of mitochondrial stress and immunogenic cell death by PT-112 in human prostate cell lines

PT-112 is a novel immunogenic cell death (ICD)-inducing small molecule currently under Phase 2 clinical development, including in metastatic castration-resistant prostate cancer (mCRPC), an immunologically cold and heterogeneous disease state in need of novel therapeutic approaches. PT-112 has been shown to cause ribosome biogenesis inhibition and organelle stress followed by ICD in cancer cells, culminating in anticancer immunity. In addition, clinical evidence of PT-112-driven immune effects has been observed in patient immunoprofiling. Given the unmet need for immune-based therapies in prostate cancer, along with a Phase I study (NCT#02266745) showing PT-112 activity in mCRPC patients, we investigated PT-112 effects in a panel of human prostate cancer cell lines. PT-112 demonstrated cancer cell selectivity, inhibiting cell growth and leading to cell death in prostate cancer cells without affecting the non-tumorigenic epithelial prostate cell line RWPE-1 at the concentrations tested. PT-112 also caused caspase-3 activation, as well as stress features in mitochondria including ROS generation, compromised membrane integrity, altered respiration, and morphological changes. Moreover, PT-112 induced damage-associated molecular pattern (DAMP) release, the first demonstration of ICD in human cancer cell lines, in addition to autophagy initiation across the panel. Taken together, PT-112 caused selective stress, growth inhibition and death in human prostate cancer cell lines. Our data provide additional insight into mitochondrial stress and ICD in response to PT-112. PT-112 anticancer immunogenicity could have clinical applications and is currently under investigation in a Phase 2 mCRPC study.

Retraction: Metformin inhibits the proliferation of benign prostatic epithelial cells.

Retraction: Metformin inhibits the proliferation of benign prostatic epithelial cells.

Interactions between androgen and IGF1 axes in prostate tumorigenesis.

Androgen signalling through the androgen receptor (AR)is essential for prostate tumorigenesis. However, androgen signalling pathways also interact with other growth factor-mediated signalling pathways to regulate the prostatic cell cycle, differentiation, apoptosis and proliferation in the initiation and progression of prostate cancer. Insulin-like growth factor 1 (IGF1) is one of the most prominent growth factors in prostate tumorigenesis. Clinical and experimental evidence has demonstrated that IGF1 signalling supports both androgen-dependent and androgen-independent prostate tumorigenesis, suggesting that improved understanding of the interactions between the IGF1 and androgen axes might aid the development of new therapeutic strategies. Available data have shown a dynamic role of androgen-AR signalling in the activation of IGF1-signalling pathways by augmenting transcription of the IGF1 receptor in prostatic basal epithelial cells and by increasing IGF1 secretion through the suppression of IGF-binding protein 3 expression in prostatic stromal cells. In turn, IGF1 stimulates Wnt-β-catenin signalling in prostatic basal progenitors to promote prostatic oncogenic transformation and prostate cancer development. These findings highlight the cooperative, autocrine and paracrine interactions that underlie the oncogenic effects of androgens and IGF1 and open up new opportunities for therapeutic targeting.

Periprostatic adipose tissue inhibits tumor progression by secreting apoptotic factors: A natural barrier induced by the immune response during the early stages of prostate cancer.

Prostate cancer (PCa) is the second most prevalent malignancy in men worldwide. The risk factors for PCa include obesity, age and family history. Increased visceral fat has been associated with high PCa risk, which has prompted previous researchers to investigate the influence of body composition and fat distribution on PCa prognosis. However, there is a lack of studies focusing on the mechanisms and interactions between periprostatic adipose tissue (PPAT) and PCa cells. The present study investigated the association between the composition of pelvic adipose tissue and PCa aggressiveness to understand the role played by this tissue in PCa progression. Moreover, PPAT-conditioned medium (CM) was prepared to assess the influence of the PPAT secretome on the pathophysiology of PCa. The present study included 50 patients with localized PCa who received robot-assisted radical prostatectomy. Medical records were collected, magnetic resonance imaging scans were analyzed and body compositions were calculated to identify the associations between adipose tissue volume and clinical PCa aggressiveness. In addition, CM was prepared from PPAT and perivesical adipose tissue (PVAT) collected from 25 patients during surgery, and its effects on the PCa cell lines C4-2 and LNCaP, and the prostate epithelial cell line PZ-HPV-7, were investigated using a cell proliferation assay and RNA sequencing (RNA-seq). The results revealed that the initial prostate-specific antigen level was significantly correlated with pelvic and periprostatic adipose tissue volumes. In addition, PPAT volume was significantly higher in patients with extracapsular tumor extension. PCa cell proliferation was significantly reduced when the cells were cultured in PPAT-CM compared with when they were cultured in control- and PVAT-CM. RNA-seq revealed that immune responses, and the cell death and apoptosis pathways were enriched in PPAT-CM-cultured cells indicating that the cytokines or other factors secreted from PPAT-CM induced PCa cell apoptosis. These findings revealed that the PPAT secretome may inhibit PCa cell proliferation by activating immune responses and promoting cancer cell apoptosis. This mechanism may act as a first-line defense during the early stages of PCa.

Multiplex Determination of Glycan Profiles on Urinary Prostate-Specific Antigen by Quartz-Crystal Microbalance Combined with Surface-Enhanced Raman Scattering.

Prostate cancer remains a major health concern, with prostate-specific antigen (PSA) being a key biomarker for its detection and monitoring. However, PSA levels often fall into a "gray zone", where PSA levels are not clearly indicative of cancer, thus complicating early diagnosis and treatment decisions. Glycosylation profiles, which often differ between healthy and diseased cells, have emerged as potential biomarkers to enhance the specificity and sensitivity of cancer diagnosis in these ambiguous cases. We propose the integration of two complementary techniques, namely quartz-crystal microbalance with dissipation (QCM-D) and surface-enhanced Raman scattering (SERS) to study PSA glycan profiles. QCM-D offers real-time operation, PSA mass quantification, and label-free detection with high sensitivity, as well as enhanced specificity and reduced cross-reactivity when using nucleic acid aptamers as capture ligands. Complementary SERS sensing enables the determination of the glycosylation pattern on PSA, at low concentrations and without the drawbacks of photobleaching, thereby facilitating multiplexed glycosylation pattern analysis. This integrated setup could retrieve a data set comprising analyte concentrations and associated glycan profiles in relevant biological samples, which may eventually improve early disease detection and monitoring. Prostate-specific antigen (PSA), a glycoprotein secreted by prostate epithelial cells, serves as our proof-of-concept analyte. Our platform allows multiplex targeting of PSA multiplex glycosylation profiles of PSA at "gray zone" concentrations for prostate cancer diagnosis. We additionally show the use of SERS for glycan analysis in PSA secreted from prostate cancer cell lines after androgen-based treatment. Differences in PSA glycan profiles from resistant cell lines after androgen-based treatment may eventually improve cancer treatment.

Abstract C097: PVT1 exon 9-dependent overexpression of RSAD2 is a characteristic of prostate cancer in males of African ancestry

Abstract Aggressive prostate cancer (PCa), including castrate-resistant and neuroendocrine subtypes, is projected to increase in incidence 5% each year. Aggressive PCa disproportionally impacts African American men, has limited effective treatment options and high mortality rates. Although racial disparities are established in PCa development, attributed to multiple contributory factors including systemic racism, differences in socioeconomic status and distrust in the medical system, work is still needed to understand the contribution of biological factors. We found the exon 9 region of plasmacytoma variant translocation 1 (PVT1) overexpressed in aggressive PCa cell lines derived from African American (AA) men. We found PVT1 exon 9 overexpression induced phenotypic changes to normal prostate epithelial cells in vitro and led to tumor formation in vivo. RNA-sequencing analysis revealed 156 significantly differentially expressed genes influenced by PVT1 exon 9 overexpression and radical S-adenosyl methionine domain containing 2 (RSAD2) was the top significantly overexpressed gene (log2Fold change 1.71, p-value < 0.05). We utilized the GSE223405 publicly available dataset to identify whether our identified PVT1 exon 9 downstream genes were enriched in AA prostate cancer cells. RSAD2 was significantly overexpressed in AA prostate cancer cells compared to prostate cancer cells from men of European ancestry (moEA) (log2Fold change 6.18, p-value < 0.05). Comparing normal cells to prostate cancer cells between these groups, we found that normal AA prostate cells had significantly higher expression of RSAD2 (log2fold change 4.25, p-value < 0.001) whereas moEA samples did not (log2fold change 0.837, p-value=0.150). From analysis of data obtained from cBioPortal, we found RSAD2 alteration significantly correlates (p-value < 0.001) with self-identified race and copy number overexpression of RSAD2 was found to be enriched in AA patients (18.16% moEA versus 24% AA). Finally, we found 88.6% of the significantly differentially expressed genes within our PVT1 exon 9 RNA-sequencing dataset were significantly differentially expressed in GSE223405 AA samples and of those, 51.7% of genes exhibited a similar differential expression pattern suggesting that the PVT1 exon 9/RSAD2 dependent pathway may be more prominent in AA men. Mechanistically, we found two differing pathways of RSAD2 overexpression in aggressive prostate cancer cell models, one dependent and one independent of PVT1 exon 9 overexpression, with similar but differing biological functions related to epigenetic processes and metabolism. Ongoing work is investigating the RSAD2 and PVT1 exon 9 expression axis in a diverse set of human prostate cancer tissues and investigating their utilization as a therapeutic target in prostate cancer. Citation Format: Rachel E. Sexton-Bonacci1, Murtaza Barkarar1, Chindeum Udekwu1, Olorunseun O. Ogunwobi1. PVT1 exon 9-dependent overexpression of RSAD2 is a characteristic of prostate cancer in males of African ancestry [abstract]. In: Proceedings of the 17th AACR Conference on the Science of Cancer Health Disparities in Racial/Ethnic Minorities and the Medically Underserved; 2024 Sep 21-24; Los Angeles, CA. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2024;33(9 Suppl):Abstract nr C097.