Androgen-independent Prostate Cancer Research Articles

From Androgen Dependence to Independence in Prostate Cancer: Unraveling Therapeutic Potential and Proteomic Landscape of Hydroxychloroquine as an Autophagy Inhibitor.

Prostate cancer is a major planetary health challenge wherein new ways of thinking drug discovery and therapeutics innovation are much needed. Numerous studies have shown that autophagy inhibition holds a significant role as an adjunctive intervention in prostate cancer. Hydroxychloroquine (HCQ) has gained considerable attention due to its established role as an autophagy inhibitor across diverse cancer types, but its proteomics landscape and systems biology in prostate cancer are currently lacking in the literature. This study reports the proteomic responses to HCQ in prostate cancer cells, namely, androgen-dependent LNCaP and androgen-independent PC3 cells. Differentially expressed proteins and proteome in HCQ-treated cells were determined by label-free quantification with nano-high-performance liquid chromatography and tandem mass spectrometry (nHPLC-MS/MS), and harnessing bioinformatics tools. In PC3 cells, there was a marked shift toward metabolic reprogramming, highlighted by an upregulation of mitochondrial proteins in oxidative phosphorylation and tricarboxylic acid cycle, suggesting an adaptive mechanism to maintain energy production under therapeutic stress. In contrast, LNCaP cells prioritized proteostasis and cell cycle regulation, indicating a more conservative adaptation strategy. To the best of our knowledge, this study is the first to demonstrate the differential responses of prostate cancer cells to autophagy inhibition by HCQ, suggesting that a combination therapy approach, targeting distinct pathways in androgen-independent and androgen-dependent cells, could represent a promising treatment strategy. Moreover, the varied proteomic responses observed between these cell lines underscore the importance of personalized medicine in cancer therapy. Future translational and clinical research on HCQ and prostate cancer are called for.

SIX2 promotes cell plasticity via Wnt/β-catenin signalling in androgen receptor independent prostate cancer.

The use of androgen receptor (AR) inhibitors in prostate cancer gives rise to increased cellular lineage plasticity resulting in resistance to AR-targeted therapies. In this study, we examined the chromatin landscape of AR-positive prostate cancer cells post-exposure to the AR inhibitor enzalutamide. We identified a novel regulator of cell plasticity, the homeobox transcription factor SIX2, whose motif is enriched in accessible chromatin regions after treatment. Depletion of SIX2 in androgen-independent PC-3 prostate cancer cells induced a switch from a stem-like to an epithelial state, resulting in reduced cancer-related properties such as proliferation, colony formation, and metastasis both in vitro and in vivo. These effects were mediated through the downregulation of the Wnt/β-catenin signalling pathway and subsequent reduction of nuclear β-catenin. Collectively, our findings provide compelling evidence that the depletion of SIX2 may represent a promising strategy for overcoming the cell plasticity mechanisms driving antiandrogen resistance in prostate cancer.

Abstract 5577: TRPM8 mediated Ca2+ signaling as a therapeutic target in prostate cancer

Abstract Prostate cancer (PC) is a prevalent and deadly malignancy, necessitating the development of innovative therapeutic strategies. Transient receptor potential melastatin 8 (TRPM8), an ion channel highly expressed in prostate epithelium, has emerged as a potential target. Our preliminary studies demonstrate that TRPM8 plays a crucial role in PC progression. We observed an initial increase in TRPM8 mRNA expression during early-stage PC, followed by a decline in advanced and androgen-independent prostate cancer (AIPC) stages. Additionally, TRPM8 knockout mice exhibited elevated serum testosterone levels, heightened androgen receptor (AR) activity, and increased cell cycle, invasion, and adhesion-related effects. In xenograft models, TRPM8 demonstrated potent antitumor properties in both AR+ and AR- contexts. Our research suggests that TRPM8 activation on the plasma membrane promotes calcium influx and induces apoptosis in PC cells. Conversely, TRPM8 internalization correlates with PC pathogenesis. By exploring the effects of TRPM8 on PTEN-mediated cellular signaling, we aim to uncover novel insights into the molecular mechanisms underlying TRPM8's role in PC. This abstract underscores the potential of targeting TRPM8-mediated Ca2+ signaling as a promising therapeutic approach to combat PC progression, offering hope for improved patient outcomes. Citation Format: Swapna Asuthkar, Kiran Velpula, Vander Don Griend. TRPM8 mediated Ca2+ signaling as a therapeutic target 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 5577.

Abstract 4656: Novel mitochondria-based targeting overcomes resistance in prostate cancer

Abstract Background: Prostate cancer (PC) is a major contributor to cancer-related mortality in men, with metastatic castration-resistant PC (mCRPC) presenting a significant obstacle due to its resistance to standard treatments. Current therapies, including nonsteroidal antiandrogens and chemotherapy drugs, provide limited effectiveness and are often accompanied by severe side effects. Recently, statins have gained attention as antitumor agents, demonstrating chemopreventive effects on a range of human cancers while maintaining a well-established safety profile. However, the use of statins as standalone treatment is limited by insufficient cancer cell targeting. Methods: We synthesized a DZ-simvastatin (DZ-SIM) conjugate that combines a near-infrared heptamethine carbocyanine dye (DZ) with simvastatin for selective tumor cell targeting. Cancer cell survival was measured by crystal violet and MTT assay. Co-localization of DZ-SIM with mitochondria and lysosome in cells was detected under confocal microscope using Mitotracker and Lysotracker. Cellular and mitochondrial cholesterol levels were detected by LC-MS. Male nude mice were inoculated subcutaneously with 22Rv1-Luc cells as a prostate cancer xenograft mouse model. We used Swiss-PDB and Rosetta algorithms to model the structure of the OATP1B3 channel. Oxygen consumption rate and extracellular acidification rate were measured by Seahorse assay. After treatment with DZ-SIM, differentially expressed genes profiling of prostate cancer cells was performed using RNAseq. Results: Our research demonstrates the conjugate's ability to effectively kill androgen-independent and metastatic PC cells without harming normal cells. Furthermore, DZ-SIM has been shown to kill multiple human PC cell lines, regardless of androgen receptor status or therapeutic resistance. DZ-SIM has been shown to inhibit growth in human prostate cancer cell line xenograft models. NIR fluorescence imaging showed specific localization of DZ-SIM to cancer, but not to normal cells and tissues. It could localize into cancer cells by binding the transmembrane transporter OATP to primarily target subcellular organelle mitochondria, decreasing the OCR and ECAR of cancer cells. DZ-SIM can bind to multiple cytosolic and mitochondrial proteins as detected by NIRF imaging. Cholesterol levels also decrease in whole cells and mitochondria. Ingenuity Pathway Analysis (IPA) of RNAseq showed that the four signaling pathways in the DZ-SIM treatment group are significantly enriched in genes related to cholesterol synthesis. Conclusion: DZ-SIM specifically targets PC cells and their mitochondria, resulting in loss of mitochondrial function and consequent cell death. With a unique subcellular targeting strategy, the conjugate holds the potential to outperform existing chemotherapeutic drugs. Citation Format: Yan Ou, Adrian Lim, Ning Zhai, Mouad Edderkaoui, Stephen Pandol, Ruoxiang Wang, Yi Zhang. Novel mitochondria-based targeting overcomes resistance 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 4656.

Abstract 5695: miR-5787 suppresses cancer cell growth as a Fe3O4-nanoparticles induced pivotal miRNA

Abstract Nanotechnology offers great potential for cancer diagnosis and treatments. Especially, nanoparticles (NPs) have been examined and utilized as drug delivery systems, hyperthermia and combination therapy. We have examined and reported the combined effects of Fe3O4-nanoparticles (Fe3O4-NPs) with chemotherapeutic agents on prostate cancer cell in vitro. miRNAs are an important factor in cancer progression, and elucidating the miRNA-mediated intracellular network of cancer cells could suggest new cancer treatment strategies. In this study, to identify microRNAs (miRNAs) associated with anticancer effects of Fe3O4-NPs, the comprehensive expression of miRNAs by Microarray (Agilent G4780A SuperPrint G3 Human v16 miRNA 8x60K Microarray kit) in A549 (lung cancer cell line), LNCaP (androgen-dependent prostate cancer cell line) and DU145 (androgen-independent prostate cancer cell line) under Fe3O4-NPs exposure was performed. miR-5787 was one of the increased miRNAs in three cancer cell lines under Fe3O4-NPs, and its increase in miR-5787 was due to the reactive oxygen species (ROS) production by Fe3O4-NPs. The additional analysis suggested that miR-5787 might suppressed the cancer cell growth by targeting the eIF5. In this study, we identified miR5787 as a Fe3O4-NPs induced pivotal miRNA in cancer cells, and can be used as a therapeutic target. Citation Format: Masatoshi Watanabe, Hitoshi Nakano, Chise Matsuda, Eri Usugi, Hiroshi Imai, Yoshifumi Hirokawa, Kazutoshi Iijima. miR-5787 suppresses cancer cell growth as a Fe3O4-nanoparticles induced pivotal miRNA [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 5695.

A Bee Trp-Arg Dense Peptide with Antiproliferation Efficacy against the Prostate Cancer Cell Line DU145.

Prostate cancer accounts for 14% of male cancer-related fatalities in the UK. Given the challenges associated with hormone-based therapies in the context of androgen-independent prostate cancer, there is an imperative need for research into anticancer drugs. N0821, a peptide belonging to the Trp-Arg dense region and derived from the homologous region of various bee species, shows substantial potential for an anticancer effect. Both MTT assays and 3D spheroid assays were conducted to substantiate its antiproliferation potential and strongly indicated the antiproliferation effect of N0820 (WWWWRWWRKI) and N0821 (YWWWWRWWRKI). Notably, the mechanism underlying this effect is related to the downregulation of CCNA2 and the upregulation of CCNE1. Cell cycle arrest results from the reduction of CCNA2 in the S/G2 phase, leading to the accumulation of CCNE1. Our peptides were predicted to make an α-helix structure. This can act as an ion channel in the cell membrane. Therefore, we analyzed genes implicated in the influx of calcium ions into the mitochondria. Trp-Arg dense-region peptides are known for their antibacterial properties in targeting cell membranes, making the development of resistance less likely. Hence, further research in this area is essential and promising.

Calotropis procera extract inhibits prostate cancer through regulation of autophagy.

Current treatment options available for prostate cancer (PCa) patients have many adverse side effects and hence, new alternative therapies need to be explored. Anticancer potential of various phytochemicals derived from Calotropis procera has been studied in many cancers but no study has investigated the effect of leaf extract of C. procera on PCa cells. Hence, we investigated the effect of C. procera leaf extract (CPE) on cellular properties of androgen-independent PC-3 and androgen-sensitive 22Rv1 cells. A hydroalcoholic extract of C. procera was prepared and MTT assay was performed to study the effect of CPE on viability of PCa cells. The effect of CPE on cell division ability, migration capability and reactive oxygen species (ROS) production was studied using colony formation assay, wound-healing assay and 2',7'-dichlorodihydrofluorescein diacetate assay, respectively. Caspase activity assay and LDH assay were performed to study the involvement of apoptosis and necrosis in CPE-mediated cell death. Protein levels of cell cycle, antioxidant, autophagy and apoptosis markers were measured by western blot. The composition of CPE was identified using untargeted LC-MS analysis. Results showed that CPE decreased the viability of both the PCa cells, PC-3 and 22Rv1, in a dose- and time-dependent manner. Also, CPE significantly inhibited the colony-forming ability, migration and endogenous ROS production in both the cell lines. Furthermore, CPE significantly decreased NF-κB protein levels and increased the protein levels of the cell cycle inhibitor p27. A significant increase in expression of autophagy markers was observed in CPE-treated PC-3 cells while autophagy markers were downregulated in 22Rv1 cells after CPE exposure. Hence, it can be concluded that CPE inhibits PCa cell viability possibly by regulating the autophagy pathway and/or altering the ROS levels. Thus, CPE can be explored as a possible alternative therapeutic agent for PCa.

Oridonin attenuated human PC-3 cell activity by modulating the Wnt/β-catenin signaling.

Prostate cancer (PC) prevention is effectively achieved through its inhibition. Oridonin (ORD), an active diterpenoid isolated from Rabdosia rubescens, has been shown to have an inhibitory effect on PC cells, although its impact on PC is unknown. The present work investigated the actions and probable mechanisms of ORD on cellular proliferation, apoptosis, PC, and the wingless-type MMTV integration site family member 2 (Wnt)/β-catenin signaling pathway using the androgen-independent PC-3 cell line. In this study, cell viability was analyzed with MTT assay method, apoptotic morphology determined using DAPI dye method, while protein (CD1333, OCT-4, Nanog, SOX-2 & Aldh1A1) and mRNA expressions were analyzed with western blotting and real time polymerase chain reaction (PCR). We demonstrated a concentration-dependent ORD inhibition of PC-3 cell proliferation and inhibition of induction apoptosis. Furthermore, ORD decreased PC-3 Wnt-2, phosphorylated glycogen synthase kinase-3 (p-GSK3), and β-catenin protein levels and downregulated cyclin-D1 and c-myc messenger ribonucleic acid (mRNA). Oridonin inhibited proliferation and induced apoptosis in PC-3 cells, with the findings suggesting that it acted via the Wnt/β-catenin pathway to exert its effects. This study demonstrates that ORD may impact PC.

Analisis Dinamik Model Sel Kanker Prostat dengan Terapi Vaksin Kuratif

Prostate cancer is a type of cancer that occurs in men and requires an effective therapeutic approach. Treatment of prostate cancer depends on the stage at diagnosis. In advanced stages of prostate cancer can be treated with hormone therapy such as chemotherapy which is then followed by vaccine therapy which aims to help increase the body's immune system response to prostate cancer cells. This model consists of a system of ordinary differential equations with five variables used, including androgen-dependent prostate cancer cells, androgen-independent prostate cancer cells, dendritic cells, effector cells, and curative vaccines. Then two equilibrium point conditions are produced, when there is no vaccine for disease free conditions and endemic conditions , then when the vaccine there are three equilibrium conditions namely disease free , side effects and local existence between prostate cancer cells with vaccine . The results of the stability analysis for each equilibrium point show that when , the condition is global asymptotic, while the condition is stable because the eigenvalue is negative. When for the condition it is unstable because the two roots are positive, then for the condition it is global asymptotic and for the condition it is asymptotically local because all the eigenvalues are negative. The numerical simulations of equilibrium points obtained using the fourth order runge-kutta method according to different q parameter values show that the larger the dendritic cells and effector cells activated, the greater the vaccine that enters the body, resulting in immune cells that will fight prostate cancer cells.

Simvastatin Enhances the Radiosensitivity of Androgen-independent Prostate Cancer Cells via Inhibition of RAD51 Expression.

Statins exert antitumor effects via various mechanisms. Additionally, the recurrence rate of prostate cancer after radiation therapy is lower in patients taking statins. This study investigated the efficacy of combination therapy with statins and irradiation in androgen-independent prostate cancer cells. PC-3 and LNCaP human prostate cancer cell lines were used in this study. We developed androgen-independent LNCaP cells (LNCaP-LA) by gradually replacing fetal bovine serum (FBS) with charcoal-stripped FBS. Microarray analysis was performed, followed by Ingenuity Pathway Analysis. Cell viability was determined using the MTS assay. Simvastatin alters gene expressions in PC-3 cells. Microarray data showed that the number of differentially expressed genes was the highest in the pathway of "Role of BRCA1 in DNA Damage Response". In the validation, the expression of RAD51, listed in "Role of BRCA1 in DNA Damage Response", decreased significantly by simvastatin in PC-3 cells. Reduction in RAD51 expression following siRNA transfection increased the cytocidal effects of X-ray therapy in PC-3 and LNCaP-LA cells. The combination of simvastatin and irradiation further inhibited cell proliferation compared with monotherapy with either therapy in PC-3 or LNCaP-LA cells. In addition, compared with X-ray monotherapy, the combination of simvastatin and irradiation further enhanced the expression of γH2AX, which is reported to be one of the accurate markers of DNA damage in PC-3 cells. Simvastatin decreased the expression of RAD51 in androgen-independent prostate cancer cells. The combination of irradiation and drugs that reduce RAD51 expression can potentially affect androgen-independent prostate cancer growth.

Reduction in Nuclear Size by DHRS7 in Prostate Cancer Cells and by Estradiol Propionate in DHRS7-Depleted Cells.

Increased nuclear size correlates with lower survival rates and higher grades for prostate cancer. The short-chain dehydrogenase/reductase (SDR) family member DHRS7 was suggested as a biomarker for use in prostate cancer grading because it is largely lost in higher-grade tumors. Here, we found that reduction in DHRS7 from the LNCaP prostate cancer cell line with normally high levels of DHRS7 increases nuclear size, potentially explaining the nuclear size increase observed in higher-grade prostate tumors where it is lost. An exogenous expression of DHRS7 in the PC3 prostate cancer cell line with normally low DHRS7 levels correspondingly decreases nuclear size. We separately tested 80 compounds from the Microsource Spectrum library for their ability to restore normal smaller nuclear size to PC3 cells, finding that estradiol propionate had the same effect as the re-expression of DHRS7 in PC3 cells. However, the drug had no effect on LNCaP cells or PC3 cells re-expressing DHRS7. We speculate that separately reported beneficial effects of estrogens in androgen-independent prostate cancer may only occur with the loss of DHRS7/ increased nuclear size, and thus propose DHRS7 levels and nuclear size as potential biomarkers for the likely effectiveness of estrogen-based treatments.

Chloroquine inhibits proliferation, survival, and migration of metastatic androgen-independent PC-3 prostate cancer cells

Chloroquine inhibits proliferation, survival, and migration of metastatic androgen-independent PC-3 prostate cancer cells

Electrochemical Aptamer-Based Biosensor Developed to Monitor PCA3 and PSA Released by Prostate Cancer Cells

1. Introduction Detection of prostate cancer (PCa) in the early stage of the disease is fundamental for the prevention of metastases and for the initiation of treatment, which may bring greater chance of patient cured; so several research groups have sought the manufacture of a simple and non-invasive methodology [1]. The early diagnosis relies on prostate specific antigen (PSA) serum test, even if it showed clear limits [2]. Recently, prostate cancer gene 3 (PCA3), a non-coding mRNA which is overexpressed in tumor cells when compared with noncancerous prostate tissue [3]. Here, we report a new method for detection of prostate cancer-specific antigen 3 (PCA3) and prostate specific antigen (PSA) released by cancer cells using an aptasensor. Electrochemical impedance spectroscopy (EIS), SEM and EDS were used to evaluate biosensor surface. 2. Experimental Part The aptamers were modified through Biosearch Technologies at 5′-terminus in C6-disulfide linker to have it bond to the gold electrode; and at 3′-end in methylene blue (MB) (as redox probe) to perform the electrochemical analysis, which was followed by the HPLC purification process to remove truncated-synthesis products and to enrich the purity of the aptamer sequences. Aptamer immobilization was done by incubation of 1 μM thiolated aptamer on the top of the gold-coated silicon electrode overnight, in the dark, at 4°C. Subsequently, the electrodes were washed with PBS and a backfilling consisted of 3 mM of MCH aqueous solution for 30 minutes was done to displace the nonspecifically adsorbed aptamer molecules and to passivate the electrode surface [26]. Finally, the electrodes were once more rinsed with PBS to remove MCH excesses. The electrochemical characterization was done in a potentiostat μAutolabIII (Metrohn, NL), using a three-electrode system, which consisted of Ag/AgCl (3M KCl), as reference electrode; Pt wire, as a counter electrode; and gold-coated silicon wafer, as a working electrode. The prostate cell lines used were normal human prostate cells (RWPE-1; ATCC® CRL-11™), androgen-sensitive human prostate cancer cells (LNCaP; ATCC® CRL-1740™), and androgen-independent human prostate cancer cells (PC-3; ATCC® CRL-1435™). The three lineages were chosen to better understand PCA3 and PSA production patterns by different cell types. 3. Results and Discussion The gold-coated silicon wafe electrode was analyzed by SEM and EDS, which acts as working electrode and substrate to anchor the thiolated aptamer on the surface. By using square wave voltammetry, the present aptasensor was able of monitoring the PCA3 and PSA released from prostate cells (normal and cancerous). The PSA and PCA3 detection limits were 1 ng/mL and 9.2 ng/mL, respectively, at linear range up to 150 ng/mL, and it was also able to detect both biomarker even in presence of several interfering compounds (UA, AA, BSA and MUC1). In addition, the herein developed aptasensor was able to verify, at accurate and robust response, the patterns of the PCA3 and PSA released by different cell lines (RWPE-1, LNCaP and PC3). The detection of PSA and PCA3 by aptasensor agree with the cell lineage type, the LNCaP is an androgen-dependent lineage. In this way, an overexpressed both biomarkres was release was verified [49,50] and it can be compared to early-stage patients. On the other hand, the PC3 cells PSA and PCA3 releasing was nearly background signal, demonstrating almost absent production of studied targets, the PC3 lineage is androgen-independent which can be compared to advanced-disease patients. Funding This work has been supported by a grant from FAPESP-Brazil, CNPq and Capes.

Receptor tyrosine kinase-like orphan receptor 1 inhibitor strictinin exhibits anti-cancer properties against highly aggressive androgen-independent prostate cancer

Aim: It is important to identify anti-cancer compounds that can inhibit specific molecular targets to eradicate androgen-receptor negative (ARneg), androgen-independent (AI) prostate cancer, which is an aggressive form of prostate cancer with limited treatment options. The goal of this study was to selectively target prostate cancer cells that have high levels of oncogenic protein Receptor tyrosine kinase-like orphan receptor 1 (ROR1) by using strictinin, a small molecule ROR1 inhibitor. Methods: The methods performed in this study include western blots, methyl thiazolyl tetrazolium (MTT) proliferation assays, phosphatidylserine apoptosis assays, apoptosis flow cytometry (Annexin V, caspase 3/7), migration scratch assays, Boyden chamber invasion assays, and cell cycle flow cytometry. Results: Strictinin was most lethal against PC3 [half-maximal drug inhibitory concentration (IC50) of 277.2 µmol/L], an ARneg-AI cell type that expresses the highest levels of ROR1. Strictinin inhibited ROR1 expression, downstream phosphatidylinositol 3-kinase (PI3K)-protein kinase B (AKT)-glycogen synthase kinase 3beta (GSK3β) pro-survival signaling, and epithelial-to-mesenchymal transition markers in PC3 cells. Additionally, strictinin decreased PC3 cell migration and invasion, while increasing S-phase cell cycle arrest. In ARneg-AI DU145 cells, strictinin inhibited ROR1 expression and modulated downstream AKT-GSK3β signaling. Furthermore, strictinin exhibited anti-migratory, anti-invasive, but minimal pro-apoptotic effects in DU145 cells likely due to DU145 having less ROR1 expression in comparison to PC3 cells. Throughout the study, strictinin minimally impacted the phenotype of normal prostatic epithelial cells RWPE-1 (IC50 of 658.5 µmol/L). Strictinin was further identified as synergistic with docetaxel [combination index (CI) = 0.311] and the combination therapy was found to reduce the IC50 of strictinin to 38.71 µmol/L in PC3 cells. Conclusions: ROR1 is an emerging molecular target that can be utilized for treating prostate cancer. The data from this study establishes strictinin as a potential therapeutic agent that targets ARneg-AI prostate cancer with elevated ROR1 expression to reduce the migration, invasion, cell cycle progression, and survival of prostate cancer.

Integrative analysis of transcriptomic and metabolomic profiles reveals enhanced arginine metabolism in androgen-independent prostate cancer cells

BackgroundProstate cancer is a common solid tumor that affects a significant number of men worldwide. Conventional androgen deprivation therapy (ADT) increases the risk of developing castration-resistant prostate cancer (CRPC). Effective clinical management of patients with CRPC is challenging due to the limited understanding.MethodsIn this study, transcriptomic and metabolomic profiles of androgen-dependent prostate cancer cell line LNCaP and the androgen-independent cells developed from LNCaP cells (LNCaP-ADR) were investigated using RNA-sequencing and LC-MS/MS, respectively. The differentially expressed genes and metabolites were analyzed, and integrative analysis of transcriptomic and metabolomic data was further conducted to obtain a comprehensive understanding of the metabolic characteristics in LNCaP-ADR cells. Quantitative real-time PCR (QPCR) was employed to ascertain the mRNA expression levels of the selected differentially expressed genes.ResultsThe arginine and proline metabolism pathway was identified as a commonly altered pathway at both the transcriptional and metabolic levels. In the LNCaP-ADR cells, significant upregulation was observed for metabolites including 5-Aminopentanoic acid, L-Arginine, L-Glutamic acid, N-Acetyl-L-alanine, and Pyrrole-2-carboxylic acid at the metabolic level. At the transcriptional level, MAOA, ALDH3A2, ALDH2, ARG1, CKMT2, and CNDP1 were found to be significantly upregulated in the LNCaP-ADR cells. Gene set enrichment analysis (GSEA) identified various enriched gene sets in the LNCaP-ADR cells, encompassing inflammatory response, 9plus2 motile cilium, motile cilium, ciliary plasm, cilium or flagellum-dependent cell motility, cilium movement, cilium, response to endoplasmic reticulum stress, PTEN DN.V1 DN, SRC UP.V1 UP, IL15 UP.V1 DN, RB DN.V1 DN, AKT UP MTOR DN.V1 UP, VEGF A UP.V1 UP, and KRAS.LUNG.BREAST UP.V1 UP.ConclusionsThese findings highlight the substantial association between the arginine and proline metabolism pathway and CRPC, emphasizing the need to prioritize strategies that target dysregulated metabolites and differentially expressed genes as essential interventions in the clinical management of CRPC.

Antiproliferative, apoptosis-inducing, and GSTP1 demethylation activities of Ellagitannins isolated from Cornus alba L.

This study aimed to prove the prostate cancer chemopreventive activity of compounds isolated from CA. We evaluated these compounds using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay and evaluated their NF-κB inhibitory activity and apoptosis-inducing activity using western blot analysis and flow cytometry, respectively. Their DNA methylation activity was also evaluated via a methylation-specific polymerase chain reaction in androgen-dependent (LNCaP) and androgen-independent (PC-3) prostate cancer cell lines. Camptothin B (1), cornusiin B (2), and cornusiin A (3), which were isolated in our previous work, relatively reduced the protein expression levels in PCa cells. Among them, cornusiin B (2) exhibited excellent NF-κB inhibitory activity. Also, concentration-dependently increased the unmethylated DNA content and decreased the methylated DNA content in both PC-3 and LNCaP cells. Therefore, cornusiin B (2), which was isolated from CA, has the potential to act as a chemopreventive agent for prostate cancer.

Photoactivation of pheophorbide-a utilizing 670 nm LEDs elicits cancer suppressive effects in androgen-independent prostate cancer cellular models.

Prostate cancer (PCa) is the most commonly diagnosed cancer and the second leading cause of cancer death in men in the USA. Photodynamic therapy (PDT) is a state-of-the-art treatment that combines high selectivity with minor side effects. Pheophorbide-a (Pheo) is a natural pigment with a photosensitizer property. Our study delved into the impact of Pheo alone or Pheo-PDT combination on the androgen-independent metastatic prostate cancer (AIPC) cell lines DU-145 and C4-2. Furthermore, an in-depth examination has been conducted on the photocytotoxicity mechanism of Pheo-PDT in these specific cell lines. In vitro studies were conducted using the AIPC cell lines. DU-145 and C4-2 cells were treated with Pheo at different concentrations for 60 min alone, or Pheo treatment followed by exposure to 670 nm illumination (60 mW/cm2 in 88 s pulses), producing 5 J/cm2 via portable light-emitting diode. Our results show that Pheo-PDT substantially inhibits cell viability, anchorage-independent growth, and migration capacities and induces autophagy and apoptosis via the over-production of reactive oxygen species that mediates endoplasmic reticulum stress in AIPC cell lines. Our study highlights the potential benefits of Pheo-PDT in metastatic hormone-insensitive PCa cell lines. It paves the way for treating localized and locally advanced PCa as a possible candidate for castration-resistant prostate cancer.

THU496 A Positive Relationship Exists Between CARF And AR In Prostate Cancer

Abstract Disclosure: K.M. Hasan: None. H. Khambati: None. R.R. Huerta: None. J. Vadgama: None. A.P. Sinha-Hikim: None. T.C. Friedman: None. Prostate cancer (PCa) is the second most prevalent cancer among men worldwide. Since PCa onset is androgen dependent, androgen deprivation therapy (ADT) is the first treatment choice for a primary tumor or metastatic PCa. However, ADT eventually leads to the development of castration resistant PCa (CRPC), which is the leading cause of higher mortality in PCa. Thus, there is a need to identify the underlying mechanisms of CRPC to manage this aggressive disease. Increased androgen receptor (AR) expression is one of the most important factors contributing to the development of CRPC. It has been shown that tumor suppressor p53 negatively regulates the expression of AR. So, loss of p53 functions has been associated with increased expression of AR in advanced PCa. However, the mechanism of p53-mediated inhibition of AR is not well understood. In this study, we demonstrated that CARF (CDKN2AIP), a p53 pathway regulatory protein, is highly expressed in PCa, but its significance in PCa development is unknown. Since, like AR, CARF is negatively regulated by p53, we hypothesize that a reciprocal relationship between CARF and p53 could regulate AR expression in PCa cells. Indeed, we found that activation of p53 by DNA damage stress inhibited both CARF and AR in LnCap and 22RV1, AR-positive, and wtp53 cell lines. Our result indicated that CARF and AR were decreased dose-dependent manner, and presumably, that could trigger cell death. Consistent with this speculation, we found that silencing CARF by ShRNA in LnCap triggered apoptosis and inhibition of cell proliferation. With great interest, we further demonstrated that silencing of CARF downregulated the AR level in LnCap and 22RV1 cells suggesting that CARF regulates the expression of AR in PCa. RT-PCR results showed that AR transcripts remained unchanged in CARF-depleted LnCap cells. This result indicated that CARF could regulate the AR stability but not the transcription. Intriguingly, we found that the expression of NEDD4, one of the AR-targeting E3 ligases, was increased in CARF-depleted cells. Therefore, by enhancing the stability, CARF could positively regulate the expression of AR in PCa cells. Further studies are in progress to know more details about the CARF-mediated AR regulation and its impact on androgen-independent PCa development and progression. Presentation: Thursday, June 15, 2023

F77 antigen is a promising target for adoptive T cell therapy of prostate cancer

Adoptive immunotherapy using chimeric antigen receptor (CAR) T cells has made significant success in treating hematological malignancies, paving the way for solid tumors like prostate cancer. However, progress is impeded by a paucity of suitable target antigens. A novel carbohydrate antigen, F77, is expressed on both androgen-dependent and androgen-independent prostate cancer cells, making it a potential immunotherapy target. This study entails the generation and evaluation of a second-generation CAR against a carbohydrate antigen on malignant prostate cancer cells. Using a single chain fragment variable (scFv) from an F77-specific mouse monoclonal antibody, we created second-generation CARs with CD28 and CD137 (4-1BB) costimulatory signals. F77 expressing lentiviral CAR T cells produce cytokines and kill tumor cells in a F77 expression-dependent manner. These F77-specific CAR T cells eradicate prostate tumors in a human xenograft model employing PC3 cells. These findings validate F77 as a promising immunotherapeutic target for prostate cancer and other malignancies with this aberrant carbohydrate structure.

Exosomal miR-222-3p contributes to castration-resistant prostate cancer by activating mTOR signaling.

Despite the clinical benefits of androgen deprivation therapy, most patients with advanced androgen-dependent prostate cancer (ADPC) eventually relapse and progress to lethal androgen-independent prostate cancer (AIPC), also termed castration-resistant prostate cancer (CRPC). MiRNAs can be packaged into exosomes (Exos) and shuttled between cells. However, the roles and mechanisms of exosomal miRNAs involved in CRPC progression have not yet been fully elucidated. Here, we find that miR-222-3p is elevated in AIPC cells, which results in remarkable enhancement of cell proliferation, migration, and invasion ability. Furthermore, Exos released by AIPC cells can be uptaken by ADPC cells, thus acclimating ADPC cells to progressing to more aggressive cell types in vitro and in vivo through exosomal transfer of miR-222-3p. Mechanistically, Exos-miR-222-3p promoted ADPC cells transformed to AIPC-like cells, at least in part, by activating mTOR signaling through targeting MIDN. Our results show that AIPC cells secrete Exos containing miRNA cargo. These cargos can be transferred to ADPC cells through paracrine mechanisms that have a strong impact on cellular functional remodeling. The current work underscores the great therapeutic potential of targeting Exo miRNAs, either as a single agent or combined with androgen receptor pathway inhibitors for CRPC treatment.