Androgen-independent Cells Research Articles

Abstract 3771: PiR-hsa-4447944 promotes the progression of prostate cancer through NEFH and induces androgen-independent growth

Abstract Introduction and Objective: Non-coding RNAs (ncRNAs) represent a diverse family of regulatory transcripts that drive tumorigenesis of prostate cancer (PCa) and various other types of cancers by their hyperactivity or diminished function. PIWI-interacting RNAs (piRNAs) are a class of small ncRNAs mechanistically similar to but much less studied than microRNAs. As the most diversified small ncRNAs, piRNAs are widely involved in the pathogenesis of different types of cancers. Our study aimed to investigate the role of piRNAs in the development of castration-resistant prostate cancer (CRPC). Methods: Small RNA sequencing was used to explore the CRPC associated piRNAs on a basis of 10 benign prostate tissues, 10 paired hormone-sensitive PCa tissues and CRPC tissues from the same patients. The top 12 upregulated piRNAs were validated through qRT-PCR in a bigger cohort. piR-hsa-4447944 was selected and investigated its biological function by gain of function in vitro. To study its loss of function role, an androgen-independent PCa cell (LNCaP-AI) was established. For mechanistic investigation, high-throughput RNA sequencing was conducted to identify dysregulated genes in PCa cells with control or piR-hsa-4447944 overexpression. Then, potential downstream targets were further predicted by miRanda program and validated by qRT-PCR, western-blot and dual-luciferase reporter assay. Results: piR-hsa-4447944 demonstrated a relatively higher expression level in both CRPC tissues and CRPC cell lines when compared with PCa tissues and cells. Functionally, overexpression of piR-hsa-4447944 could confer resistance to androgen deprivation and anti-androgen in PCa cells in vitro, whereas anti-sense RNA against the piR-hsa-4447944 could potentiate the sensitivity to androgen deprivation in LNCaP-AI cell. In addition, piR-hsa-4447944 showed the ability in promoting migration and invasion of PCa cells. Mechanistically, mRNA sequencing results identified a panel of downstream target-genes. Among them, neurofilament heavy chain (NEFH) was predicted and validated to have a direct binding relationship with piR-hsa-4447944, and was successfully verified to be negatively regulated by piR-hsa-4447944 in PCa cells. Conclusions: Our study showed, for the first time, that piR-hsa-4447944 can contribute to androgen insensitivity in CRPC. This sheds a new insight into the regulation of CRPC by a small ncRNA piRNA, which may form the basis of a novel target in the treatment of CRPC. Citation Format: Qiang Peng, Jingkai Sun, Peter Ka-Fung Chiu, Tingting Xie, Jeremy Yuen-Chun Teoh, Chi-Fai Ng. PiR-hsa-4447944 promotes the progression of prostate cancer through NEFH and induces androgen-independent growth. [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 3771.

Abstract 2858: Radiotherapy and NK cell-based immunotherapy: An evolutionary double-bind

Abstract Evolution-informed therapies exploit the ecological and evolutionary consequences of drug resistance to inhibit the expansion of treatment resistant populations and prolong time to progression. One strategy, termed an evolutionary double-bind, uses an initial therapy to elicit a specific adaptive mechanism that is then selectively targeted by a follow-on therapy. Here we examine combining radiation therapy followed by immunotherapy as a double bind strategy. Radiotherapy (RT) induces lethal double-strand DNA breaks in tumor cells and radiosensitivity is governed by the cells’ DNA repair capabilities. Radioresistant cancer cells upregulate DNA damage response pathways. However, successful adaptations to RT and other DNA damaging agents can increase natural killer (NK) cell ligand expression on tumor cells increasing their vulnerability to the immune system. We conducted a multidisciplinary investigation of this potential evolutionary double bind using an isogenic cell line model of radiation resistance derived from an androgen-independent human prostate carcinoma cell line (22Rv1). We demonstrate that RT-resistant cells maintain higher expression of NK cell ligands and have a 2-fold increase in sensitivity to NK cell mediated killing. Furthermore, we show that preferential targeting of the RT-resistant population by NK cells is preserved in competition assays with varying initial population frequencies. Scope of treatment responses are dependent on population frequencies in our in vitro analysis. Mathematical modeling quantified three key elements of a double-bind: cost of resistance, inter-specific competition between RT-sensitive and RT-resistant lines, and preferential targeting of RT-resistant lines by NK cells. We conclude that RT followed by immunotherapy produces an evolutionary double bind that can be exploited in heterogenous tumors to limit RT resistance. Furthermore, model simulations predict that extinction of both populations is achievable by sequential RT and NK cell therapy. Citation Format: Kimberly Luddy, Jeffery West, Mark Robertson-Tessi, Bina Desai, Taylor M. Bursell, Sarah Barrett, Joel Brown, Jacintha O'Sullivan, Robert Gatenby, Laure Marignol, Alexander R. Anderson, Cliona O'Farrelly. Radiotherapy and NK cell-based immunotherapy: An evolutionary double-bind [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 2858.

4-Nerolidylcatechol (4-NC) and Docetaxel Synergize in Controlling Androgen- independent Prostate Cancer Cells.

Effective cancer treatment still challenges medicine since the strategies employed so far are not sufficiently safe and capable of specifically eliminating tumor cells. Prostate cancer (PCa) is a highly incident malignant neoplasm, and the outcome of patients, especially those with advanced castration-resistant PCa (CRPC), depends directly on the efficacy of the therapeutic agents, such as docetaxel (DOC). This study investigated the synergistic potentiation of 4-nerolidylcatechol (4-NC) with DOC in inhibiting androgen-independent PCa cells. The cytotoxic effect of 4-NC was evaluated against non-tumorigenic (RWPE-01) and PCa cell lines (LNCaP and PC-3), and the antiproliferative potential of 4-NC was assessed by flow cytometry and colony formation. The Chou-Talalay method was applied to detect the synergistic effect of 4-NC and DOC, and the mechanism of anticancer activities of this combination was investigated by analyzing players in epithelial-mesenchymal transition (EMT). 4-NC significantly reduced the viability of PC-3 cells in a dose-dependent manner, decreasing colony formation and proliferation. The combination of 4-NC and DOC was synergistic in the androgen-independent cells and allowed the reduction of DOC concentration, with increased cytotoxicity and induction of apoptosis when compared to compounds alone. Furthermore, when 4- NC was co-administered with DOC, higher expression levels of proteins associated with the epithelial phenotype were observed, controlling EMT in PC-3 cells. Collectively, these data demonstrated, for the first time, that the combination of 4-NC with reduced doses of DOC could be especially valuable in the suppression of oncogenic mechanisms of androgen-independent PCa cells.

MP20-12 PiR-hsa-24683 IS ESSENTIAL FOR PROSTATE TUMOR-PROPAGATING CELLS AND PROMOTE THE DEVELOPMENT OF CASTRATION RESISTANCE

You have accessJournal of UrologyCME1 Apr 2023MP20-12 PiR-hsa-24683 IS ESSENTIAL FOR PROSTATE TUMOR-PROPAGATING CELLS AND PROMOTE THE DEVELOPMENT OF CASTRATION RESISTANCE Qiang Peng, Peter Ka-Fung Chiu, Tingting Xie, Jeremy Yuen-Chun Teoh, and Chi-Fai Ng Qiang PengQiang Peng More articles by this author , Peter Ka-Fung ChiuPeter Ka-Fung Chiu More articles by this author , Tingting XieTingting Xie More articles by this author , Jeremy Yuen-Chun TeohJeremy Yuen-Chun Teoh More articles by this author , and Chi-Fai NgChi-Fai Ng More articles by this author View All Author Informationhttps://doi.org/10.1097/JU.0000000000003245.12AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookLinked InTwitterEmail Abstract INTRODUCTION AND OBJECTIVE: PIWI-interacting RNAs (piRNAs) are a class of small non-coding RNAs (sncRNAs) mechanistically similar to but much less studied than microRNAs. piRNAs represent the most diversified sncRNAs that are widely involved in the pathogenesis of different types of cancers including prostate cancer (PCa). Our study aimed to investigate the role of piRNAs in the development of castration-resistant prostate cancer (CRPC). METHODS: Small RNA sequencing was used to explore the CRPC associated piRNAs on a basis of 10 benign prostate tissues, 10 paired hormone-sensitive PCa tissues and CRPC tissues from the same patients. The top 8 upregulated piRNAs were validated through qRT-PCR in a bigger cohort. piR-hsa-24683 was selected and investigated its biological function by gain of function in vitro. To study its loss of function role, an androgen-independent PCa cell (LNCaP-AI) was established. For mechanistic investigation, the mRNA sequencing analysis of differentially expressed genes (DEGs) was conducted in PCa cells transfected with control/piR-hsa-24683 mimics. Then, potential downstream targets were further predicted by miRanda program and validated by qRT-PCR. RESULTS: piR-hsa-24683 demonstrated a relatively higher expression level in both CRPC tissues and CRPC cell lines when compared with PCa tissues and cells. Functionally, overexpression of piR-hsa-24683 could confer resistance to androgen deprivation and anti-androgen in PCa cells in vitro, whereas anti-sense RNA against the piR-hsa-24683 could potentiate the sensitivity to androgen deprivation in LNCaP-AI cell. In addition, piR-hsa-24683 showed the ability in promoting sphere formation, migration and invasion of PCa cells. Mechanistically, mRNA sequencing results identified a panel of downstream target-genes. Among them, serine/threonine kinase 3 (STK3) was predicted to have a direct binding relationship with piR-hsa-24683, and was successfully verified to be negatively regulated by piR-hsa-24683. CONCLUSIONS: Our study showed, for the first time, that piR-hsa-24683 can contribute to androgen insensitivity in CRPC. This sheds a new insight into the regulation of CRPC by a sncRNA piRNA, which may form the basis of a novel target in the treatment of CRPC. Source of Funding: UGC Research Matching Fund 8601404 © 2023 by American Urological Association Education and Research, Inc.FiguresReferencesRelatedDetails Volume 209Issue Supplement 4April 2023Page: e279 Advertisement Copyright & Permissions© 2023 by American Urological Association Education and Research, Inc.MetricsAuthor Information Qiang Peng More articles by this author Peter Ka-Fung Chiu More articles by this author Tingting Xie More articles by this author Jeremy Yuen-Chun Teoh More articles by this author Chi-Fai Ng More articles by this author Expand All Advertisement PDF downloadLoading ...

Using microfluidic models to evaluate whether monocyte preconditioning plays a role in tumor-associated macrophage mediated resistance to hormone therapy in men with prostate cancer.

228 Background: While men with metastatic castrate-resistant prostate cancer benefit greatly from 2nd generation androgen targeted therapies (ATTs), the utility of these therapies is inevitably limited by the development of resistance. Tumor associated macrophages (TAMs) are a myeloid immune cell population within the prostate tumor microenvironment (TME) that have been shown to play an integral role in development of ATT-resistance. However, the pathways that underlie TAM-mediated ATT resistance remain under investigation. In particular, many TAMs within the TME are derived from circulating monocytes and it is not yet clear whether the pathways driving TAM-mediated resistance are activated exclusively within the TME or if the activation of critical resistance pathways begins while the cells are circulating as monocytes. In this study, we utilized novel microscale technologies to investigate the transcriptome of monocytes and macrophages derived from patients progressing and responding to ATTs as well as the degree to which the macrophages promote ATT resistance in prostate tumor models. Methods: Primary monocytes were isolated from 22 men with prostate cancer who were either progressing or responding to 2ndgeneration ATTs. A portion of the monocytes from each patient were isolated for transcriptome analysis and the rest were differentiated into monocyte-derived macrophages (MDMs). MDMs were then cultured in monoculture or in co-culture with androgen-independent prostate tumor cells (22Rv1 and C42B). Each culture was then left untreated or treated with enzalutamide therapy. Following culture/treatment, each macrophage condition was isolated for transcriptome analysis and tumor cell populations from each condition were evaluated for treatment cytotoxicity. Results: Viability data from MDM-C42B co-culture demonstrated a 20% increase in tumor cell viability following enzalutamide treatment when C42B cells were cultured with primary MDMs from castrate-sensitive patients as compared to MDMs from castrate-resistant patients. Subsequent transcriptome analysis demonstrated key signatures in monocyte/macrophage populations that were associated ATT response. Conclusions: Leveraging a novel microfluidic culture platform known as Stacks, we were able to utilize primary, patient-derived cells to demonstrate that the role of TAMs in ATT resistance within the prostate TME is dependent, at least in part, on factors that are present prior to extravasation into the TME. Transcriptome analysis identified candidate pathways, which may be driving TAM-mediated differences in ATT response. These findings have the potential to lead to future use of circulating monocytes as a predictive biomarker as well as lead to the identification and targeting of ATT resistance pathways in patients.

THE INFLUENCE OF SPERMINE AND CHLORHEXIDINE ON THE SURVIVAL, ELECTROKINETIC AND CYTOMORPHOLOGICAL CHARACTERISTICS OF HUMAN PROSTATE CANCER CELLS

Summary. Aim: to study the effects of spermine and the spermine oxidase inhibitor chlorhexidine, applied alone or in combination, on the viability, electrokinetic and structural-functional characteristics of human prostate cancer cells in vitro. Object and methods: Studies were conducted on cell cultures: differentiated androgen-dependent LNCaP cell line and low-differentiated androgen-independent DU-145 cell line. Cell survival was determined by the method of exclusion of the vital dye trypan blue by living cells. The electrokinetic parameters of the cells (ζ-potential and total surface charge density) were determined according to the Smoluchovsky and Quincke-Helmholtz equations. Morphological changes were assessed by light microscopy of fixed preparations of cells stained with hematoxylin and eosin. Results: The fact established by previous studies that spermine at a concentration of 1.5 mM exhibits a pronounced inhibitory effect on the growth of differentiated human prostate cancer cells of the LNCaP line, which consists in reducing their survival to 48.5 ± 1.5% compared to intact control, and when this factor is used in a concentration exceeding 5.0 mM – in their death. It was shown that poorly differentiated cells of the DU-145 line were significantly more resistant to its influence: their survival decreased to 56.0 ± 1.9% only under the influence of spermine at a concentration of 5.0 mM; a concentration of 10.0 mM caused complete cell death of both lines. The trend persisted in the case of chlorhexidine: under its influence at a concentration of 15.0 μM, the survival of cells of the hormone-dependent LNCaP line was 33.0 ± 1.5%, and the hormone-independent DU-145 cell line was 79.0 ± 2.5%. The combined use of spermine and chlorhexidine (0.6 mM and 3.2 µM, respectively) caused a strong cytotoxic effect in cells of the LNCaP line (survival 19.0 ± 1.2%), while cells of the DU-145 line maintained a fairly high rate (76.0 ± 2.1%) even with a significantly higher content of spermine (3.0 mM) and chlorhexidine (5.0 μM) in the culture medium. It was established that under the influence of chlorhexidine, the cells of both studied lines show an inversion of the sign of the surface electric charge, changing it from negative to positive under physiological conditions, just as it was shown in experiments with spermine on cells of the LNCaP line. Certain quantitative differences caused by the investigated compounds in the electrokinetic indicators of cells of hormone-dependent and hormone-independent lines were revealed. Cells of the DU-145 line under the influence of spermine, or simultaneously spermine and chlorhexidine, showed a typical apoptotic morphology: they rounded and separated from each other and the substrate, chromatin condensation, blurred contours of the surface membrane, nuclear fragmentation and the presence of apoptotic bodies were noted. Conclusions: Spermine in concentrations of 1.5-10.0 mM and chlorhexidine in concentrations of 10.0-30.0 μM, applied separately, have a cytotoxic effect on human prostate cancer cells of LNCaP and DU-145 lines in culture. Cytotoxic properties of spermine, chlorhexidine or their combination are significantly more pronounced when acting on the hormone-dependent LNCaP line cells than on the hormone-independent DU-145 line. Their combined use demonstrates a significantly higher cytotoxic effect on cells of the LNCaP line, which is not observed in the DU-145 cell line. Chlorhexidine, like spermine, causes an inversion of the surface charge in the studied cell lines, changing its sign from negative to positive. The revealed differences like changes in survival and electrokinetic parameters of LNCaP and DU-145 cells can be explained by the presence or absence of androgen binding receptors on their surface membrane. Cells of the DU-145 line under the influence of spermine, or at the same time spermine and chlorhexidine, go to the state of apoptosis, as well as cells of the LNCaP line when they are exposed to spermine.

Combination with vorinostat enhances the antitumor activity of cisplatin in castration-resistant prostate cancer by inhibiting DNA damage repair pathway and detoxification of GSH.

Like DNA methylation, histone modifications are considered important processes for epigenetic alterations in gene function, and abnormally high expression of histone deacetylases (HDACs) plays a key role in many human diseases. In addition to regulating the acetylation levels of histone and non-histone proteins and gene transcription, HDAC inhibitors as antitumor drugs can also affect the DNA damage repair (DDR) pathway in tumor cells. Prostate cancer (PCa) is one of the most heritable malignancies in which DDR pathway defects can be detected in a considerable proportion of cases. Such defects are more prevalent in castration-resistant prostate cancer (CRPC) and are highly enriched in metastatic lesions. There is currently evidence that DDR pathway-deficient PCa is associated with high-risk biological behaviors and response sensitivity to platinum-based chemotherapy. Platinum-based drugs have been used in multiple clinical trials as monotherapy or in combination with other chemotherapeutic agents for the treatment of CRPC. This study evaluated the combined anticancer effect of (cisplatin) CDDP and the HDAC inhibitors vorinostat (SAHA) on three androgen-dependent cell lines PC-3, DU-145, and C4-2B in vitro. The efficacy and safety of SAHA combined with CDDP in the treatment of CRPC were further verified through animal experiments. The combination of the two drugs increases cytotoxic effects by increasing DNA damage. Our results showed that the SAHA could not only reduce the expression of homologous recombinant repair proteins BRCA2, BRCA1, PARP1, and RAD51, but also decrease enzymes that Reduce the key enzymes of GSH biosynthesis, GSS and GCLC, and GSTP1 which can catalyze the binding of GSH to cisplatin. The intracellular GSH level also decreased with the increase of SAHA concentration, at the same time, the content of intracellular Pt element. The combination of CDDP and SAHA can produce synergistic anticancer effects in androgen-independent PCa cells in vitro and in vivo. Our results open up a new avenue for the effective treatment of CRPC. To optimize the chemotherapy regimen for patients with advanced PCa, it is necessary to further study the molecular mechanism of platinum drugs, HDAC inhibitors, and their combined action.

Acute effect of high-intensity interval aerobic exercise on serum myokine levels and resulting tumour-suppressive effect in trained patients with advanced prostate cancer.

Although skeletal muscle releases cytokines called myokines during exercise, the kinetics of the acute myokine response to exercise (exercise-induced circulatory myokine level alteration) is unknown in patients with advanced prostate cancer. We measured myokine levels in serum obtained from patients with metastatic castrate-resistant prostate cancer (mCRPC) before and after exercise and assessed the growth-suppressive effect of the serum by applying it to a PCa cell line. Nine patients with mCRPC (age = 67.8 ± 10.1 years, time since mCRPC diagnosis 36.2 ± 22.5 months) undertook 34 min of a high-intensity interval exercise session on a cycle ergometer. Blood was collected immediately pre, post and 30 min post. Serum levels of secreted protein acidic and rich in cysteine (SPARC), oncostatin M (OSM), interleukin-6 (IL-6), interleukin-15 (IL-15), decorin, irisin, and IGF-1 were determined. Growth of the androgen-independent PCa cell line DU-145 exposed to serum collected at three points was measured. There was a significant elevation of SPARC (19.9%, P = 0.048), OSM (11.5%, P = 0.001), IL-6 (10.2%, P = 0.02) and IL-15 (7.8%, P = 0.023) in serum collected immediately after exercise compared to baseline, returning to baseline after 30 min rest. A significant reduction in DU-145 Cell growth and the Cell Index area under the curve at 72 h incubation was observed with the presence of serum obtained immediately post-exercise (Cell Index at 72 h: 16.9%, P < 0.001; area under the curve: 15.2%, P < 0.001) and with the presence of serum obtained 30 min post-exercise compared to baseline (Cell Index at 72 h: 6.5%; area under the curve: 8.8%, P < 0.001). This study provides preliminary evidence for an acute exercise-induced myokine response and tumour growth suppression in serum after a bout of high-intensity interval exercise in patients with advanced PCa.

Lncap-AI prostate cancer cell line establishment by Flutamide and androgen-free environment to promote cell adherent

BackgroundTo establish castration-resistant prostate cancer (CRPC) - Lncap androgen-independent (AI) cell line from Lncap androgen-dependent (AD) cell line, and explore the different molecular biological between these two cell lines.MethodsThe Lncap-AD cell line was cultured and passaged 60 times over 16 months. The morphology of the Lncap-AI cell line was observed. AR levels identification were detected in qRT-PCR and Western Blot assay. CCK-8, EdU assay, wound healing assay and cell adhesion assays were used to observe the ability of proliferation, migration, and adhesion. SEM and TEM were used to observe microculture structure. At last, the PSA secrete ability was evaluated by Elisa assay.ResultsThe Lncap-AD cell line was cultured and passaged 60 times over 16 months. The Lncap-AI cell line showed a morphologic change at the end stage of culture, the cells turned slender and cell space turned separated compared to the Lncap-AD cell line. The relative levels of AR-related genes in the Lncap-AI cell line were up-regulation compared to the Lncap-AD cell line both in mRNA and protein levels. The expression of AR and HK2 proteins were influenced and down-regulation by Enzalutamide in the Lncap-AD cell line, but no obvious difference in Lncap-AI cell lines. Lncap-AI cell line showed strong viability of proliferation, migration, and adhesion by CCK-8, EdU assay, wound healing assay, and adhesion assay. The microstructure of Scanning Electron Microscopy (SEM) showed many synapses in the Lncap-AI cell line and PC3 cell line, but not in the Lncap-AD cell line. At last, the PSA secrete ability was evaluated by Elisa assay, and PCa cell lines showed no significant difference.ConclusionSimulation of CRPC progression, Lncap-AD cell line turned to Lncap-AI cell line with androgen deprivation therapy.

Bicalutamide Anticancer Activity Enhancement by Formulation of Soluble Inclusion Complexes with Cyclodextrins.

Bicalutamide (BCL) is a nonsteroidal antiandrogen drug that represents an alternative to castration in the treatment of prostate cancer, due to its relatively long half-life and tolerable side effects. However, it possesses a very low water solubility that can affect its oral bioavailability. In this work, we developed inclusion complexes of BCL with the highly soluble hydroxypropyl-β-cyclodextrin (HP-β-CyD) and sulfobutylether-β-cyclodextrin (SBE-β-CyD) to increase the water solubility and anticancer activity of BCL. The inclusion complexes were prepared using the freeze-drying method and were then characterized in a solid state via differential scanning calorimetry and X-ray analysis and in solution via phase-solubility studies and UV-vis and NMR spectroscopy. The BCL/HP-β-CyD and BCL/SBE-β-CyD inclusion complexes were amorphous and rapidly dissolved in water. Both the 1H-NMR spectra and molecular modeling studies confirmed the penetration of the 2-(trifluoromethyl)benzonitrile ring of BCL within the cavity of both cyclodextrins (CyDs). Due to the consistent improvement of the water solubility of BCL, the inclusion complexes showed higher antiproliferative activity toward the human prostate androgen-independent cell lines, DU-145 and PC-3, with respect to free BCL. These results demonstrate the ability of HP-β-CyD and SBE-β-CyD to complex BCL, permitting the realization of liquid formulations with potentially high oral bioavailability and/or possible parenteral administration.

Novel 4-Azapregnene Derivatives as Potential Anticancer Agents: Synthesis, Antiproliferative Activity and Molecular Docking Studies

A series of novel 21E-arylidene-4-azapregn-5-ene steroids has been successfully designed, synthesized and structurally characterized, and their antiproliferative activity was evaluated in four different cell lines. Within this group, the 21E-(pyridin-3-yl)methylidene derivative exhibited significant cytotoxic activity in hormone-dependent cells LNCaP (IC50 = 10.20 µM) and T47-D cells (IC50 = 1.33 µM). In PC-3 androgen-independent cells, the steroid 21E-p-nitrophenylidene-4-azapregn-5-ene was the most potent of this series (IC50 = 3.29 µM). Considering these results, the 21E-(pyridin-3-yl)methylidene derivative was chosen for further biological studies on T47-D and LNCaP cells, and it was shown that this azasteroid seems to lead T47-D cells to apoptotic death. Finally, molecular docking studies were performed to explore the affinity of these 4-azapregnene derivatives to several steroid targets, namely 5α-reductase type 2, estrogen receptor α, androgen receptor and CYP17A1. In general, compounds presented higher affinity to 5α-reductase type 2 and estrogen receptor α.

Dynamics of a non-smooth model of prostate cancer with intermittent androgen deprivation therapy

Intermittent androgen deprivation therapy (IADT) is widely used in the clinic treatment for prostate cancer. We propose a Filippov system in this paper, which defines the following threshold policy: the androgen deprivation therapy (ADT) is implemented once the concentration of androgen-dependent (AD) cells exceeds the threshold level ET and it is suspended otherwise. To better understand the effect of the IADT on the evolution of prostate cancer, we perform a comprehensive qualitative analysis of global dynamics of the targeted model. As the threshold value varies, our model admits multistability of three equilibria, bistability of two equilibria, stability of the regular equilibrium or the pseudo-equilibrium, and the boundary equilibrium bifurcation. The steady-state regimes include high concentration, low concentration and no androgen-independent cells. This highlights the critical role of threshold values and the initial condition of prostate cancer cells of patients. The main results indicate that the concentration of AD cells and AI cells can be contained at a relatively satisfactory level, which can help to make treatment schedule and improve treatment outcomes for patients with prostate cancer.

The effect of ciprofloxacin on doxorubicin cytotoxic activity in the acquired resistance to doxorubicin in DU145 prostate carcinoma cells.

The present study aimed to assess the influence of ciprofloxacin (CIP) against the doxorubicin (DOX)-resistant androgen-independent prostate cancer DU145 cells. The DOX-resistant DU145 (DU145/DOX20) cells were established by exposing DU145 cells to the increasing concentrations of DOX. The antiproliferative effect of CIP was examined through employing MTT, colony formation, and 3D culture assays. DU145/DOX20 cells exhibited a twofold higher IC50 value for DOX, an increased ABCB1 transporter activity, and some morphological changes accompanied by a decrease in spheroid size, adhesive and migration potential compared to DU145 cells. CIP (5 and 25µgmL-1) resulted in a higher reduction in the viability of DU145/DOX20 cells than in DU145 cells. DU145/DOX20 cells were more resistant to CIP in 3D culture compared to the 2D one. No spheroid formation was observed for DU145/DOX20 cells treated with DOX and CIP combination. CIP and DOX, alone or in combination, significantly reduced the growth of DU145 spheroids. CIP in combination with 20nM DOX prevented the colony formation of DU145 cells. The clonogenicity of DU145/DOX20 cells could not be estimated due to their low adhesive potential. CIP alone caused a significant reduction in the migration of DU145 cells and resulted in a more severe decrease in the wound closure ability of DOX-exposed ones. We identified that CIP enhanced DOX sensitivity in DU145 and DU145/DOX20 cells. This study suggested the co-delivery of low concentrations of CIP and DOX may be a promising strategy in treating the DOX-resistant and -sensitive hormone-refractory prostate cancer.

Xenografts on nude mouse diaphragm of human DU145 prostate carcinoma cells: mesothelium removal by outgrowths and angiogenesis

ABSTRACT Human prostate carcinoma DU145 cells, androgen-independent malignant cells, implanted in the athymic nu/nu male mouse, developed numerous tumors on peritoneal and retro-peritoneal organs whose growth aspects and vascular supply have yet to be investigated with fine structure techniques. A series of necropsies from moribund implanted mice diaphragms were examined with light, scanning, and transmission electron microscopy. DU145 xenografts installations, far away from the implanted site, were described as the smallest installation to large diaphragm outgrowths in moribund mice. Carcinomas did not show extracellular matrix and, reaching more than 0.15 mm in thickness, they revealed new structures in these outgrowths. Voids to be gland-like structures with mediocre secretion and, unexpectedly, intercellular spaces connected with fascicles of elongated DU145 cells that merged with a vascular supply originated from either the tumor cells and/or some perimysium vessels. In the largest carcinomas, most important vascular invasions coincidently accompanied the mouse lethality, similarly to human cancers. This androgen-independent model would be useful to study tumor outgrowth’s changes related to testing anticancer strategy, including anti-angiogenic therapies involving toxicity, simultaneously with those of other vital organs with combined biomolecular and fine structure techniques.

A narrative review of the role of glucocorticoid receptors in prostate cancer: developments in last 5 years.

Background and ObjectiveGlucocorticoids, secreted from the adrenal gland, are commonly used in the treatment of castration-resistant prostate cancer (CRPC) because of their anti-inflammatory and anti-toxic effects. However, glucocorticoids have been reported to have the opposite effects within the course of treatment. Many studies have shown that glucocorticoid receptors (GRs) are involved in the establishment of a dominant population of androgen-independent malignant cells, which may result in CRPC. In this review, we summarized the mechanisms of GRs in CRPC and the clinical application of glucocorticoids based on the present evidence.MethodsWe summarized the isoforms of GRs and the mechanisms involved in CRPC. An updated literature search was performed from the ClinicalTrials database, the National Center for Biotechnology Information database and European Union Drug Regulating Authorities Clinical Trials database. The focus was on the timeframe from 2017 to 2022. At least one primary or secondary outcome [prostate-specific antigen (PSA) response rate, progression-free survival (PFS) or overall survival (OS) and median time to PSA progression] according to studies should be included.Key Content and FindingsThe molecular structures and applications of the isoforms of GR have been intensively researched in the past 60 years. In recent years, researchers have pointed out that GRs may be involved in the development of CRPC via genomic and non-genomic effects. Clinical trials in the past 5 years have focused on the efficacy of drugs regarding CRPC. The use of glucocorticoids during treatments of CRPC follows the guidelines (e.g., NCCN Guidelines®, guidelines of CSCO, etc.). Based on the collected data, prednisone appears to be the most widely used steroid hormone, followed by dexamethasone. Comparisons of the PSA response rate and the median time to PSA progression revealed that the efficacy of the 2 hormones is similar; however, further research on the effect of steroid hormone in CRPC is still required.ConclusionsVarious GR isoforms may play an important part in the development of CRPC, whose mechanism remains unclear. Most clinical trials have focused on the use of prednisone in the last 5 years. The efficacy of prednisone and dexamethasone is similar.

Expression of MUS81 Mediates the Sensitivity of Castration-Resistant Prostate Cancer to Olaparib.

This project attempts to clarify the expression of MUS81 in castration-resistant prostate cancer (CRPC) and the effect on drug sensitivity to Olaparib. We collected clinical surgical samples of patients who were suffering from benign prostatic hyperplasia (BPH), common prostate cancer (PCa), and castration-resistant prostate cancer (CRPC) and detected the expression of MUS81 in healthy prostate epithelial cells, PCa cells, and androgen-independent PCa cells. We subsequently performed CCK-8 assays, flow cytometry, and Transwell invasion and migration assay to determine the proliferation, apoptosis, invasion, and metastasis abilities of transfected CRPC cells as well as drug toxicity of Olaparib to CRPC cells. The expression of MUS81 indicated marked upregulation in PCa and CRPC tissues, compared with the level of MUS81 in BPH tissues. MUS81 silencing inhibited the proliferation of CRPC cells and promoted their sensitivity to Olaparib. MUS81 silencing in CRPC cells remarkably accelerated cell apoptosis and greatly inhibited cell invasion and metastasis after Olaparib administration. MUS81 silencing in CRPC cells has significantly enhanced the sensitivity of cells to Olaparib, which provides evidence for the prediction of Olaparib resistance in CRPC cells by the MUS81 gene and is expected to become a promising gene target in CRPC therapy.

Abstract 5670: TRPM8 ion channel role in prostate cancer: Actions as a rapid testosterone signaling receptor

Abstract The transient receptor potential melastatin 8 (TRPM8) is well-known for its role in cold sensation in somatosensory neurons. TRPM8 was first identified as a prostate epithelial cell-specific gene, however, its role was unclear due to the absence of its endogenous agonist. We are the first to discover the novel role of TRPM8 as a rapid testosterone receptor. The TRPM8 mRNA is highly expressed in prostate cancer (PC) and is lost during the transition to androgen-independent prostate cancer (AIPC). Although emerging studies have shed light regarding androgen regulation of TRPM8 mRNA expression, we found that the addition of androgen receptor (AR) on the lipid bilayers inhibited testosterone-TRPM8 induced Ca2+ uptake. Additionally, our IHC revealed increased internalization of the TRPM8 protein in high-grade PC and that TRPM8 protein was targeted for proteasomal degradation in PC. We observed that inhibition of AR and UBA1 promoted the stabilization of TRPM8 on the plasma membrane, triggering Ca2+-induced cytotoxicity and apoptosis in both androgen dependent and androgen independent PC cells. Furthermore, in line with previous studies, we showed that testosterone-induced TRPM8 activation on the planar lipid bilayers also required phosphatidylinositol 4,5-bisphosphate (PIP2). Loss of PTEN is associated with tumor recurrence and the transition to AIPC. Thus, PTEN loss mediated PIP2 deficiency may be an important mechanism of TRPM8 desensitization in PC. Therefore, we propose that the rescue of TRPM8 activity on the plasma membrane combined with AR targeting may be an effective therapy for PC. Citation Format: Kiran Velpula, Katherine Shishido, Susovon Bayen, Swapna Asuthkar. TRPM8 ion channel role in prostate cancer: Actions as a rapid testosterone signaling receptor [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 5670.

Abstract 1543: Regulatory role of miR-410 in prostate cancer

Abstract Prostate cancer (PCa), a leading cause of male cancer related mortality, is dependent upon androgens acting via androgen receptor (AR) signaling. Androgen targeted therapies are often used as the first line of treatment for prostate cancer that are effective initially. However, PCa eventually progresses to castration-resistant stage that has limited treatment options. Castration-resistant prostate cancer (CRPC) is treated by second generation of AR pathway inhibitors such as Enzalutamide and Abiraterone. Resistance to these agents develop owing to various mechanisms such as evolution to androgen-independent neuroendocrine prostate cancer (NEPC). In this study, we examined the potential role of miR-410 in different stages of prostate cancer. Analyses of miR-410 in PCa clinical samples and patient-derived xenograft (PDX) models showed that miR-410 is frequently upregulated in PCa. Its expression was further increased in CRPC cases with neuroendocrine differentiation (NED). We examined the functional role of miR-410 by stably expressing miR-410 in androgen dependent and androgen independent cell lines. Our data suggests a context dependent role of miR-410 in prostate cancer cell lines. In androgen independent cell line, miR-410 plays an oncogenic role by impacting epithelial to mesenchymal transition (EMT) via directly targeting SNAIL. Also, it was found to increase the expression of neuronal genes such as Synaptophysin and neural transcription factor BRN2. However, in androgen dependent cell line, miR-410 was found to target PTEN. In conclusion, our data suggests that miR-410 play an important regulatory role in prostate cancer with effects on EMT and neuronal differentiation programs. Citation Format: Amritha Sreekumar, Nikhil Patel, Sharanjot Saini. Regulatory role of miR-410 in prostate cancer [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 1543.

Abstract 3311: Darolutamide potentiates the antitumor efficacy of a PSMA-targeted thorium-227 conjugate (PSMA-TTC) in a hormone-independent prostate cancer model

Abstract Androgen receptor (AR) inhibitors are standard of care for the treatment of advanced prostate cancer. Despite an initial response to treatment, patients eventually progress, and novel therapeutic approaches are required. Prostate-specific membrane antigen (PSMA; FOLH1) is an integral membrane glycoprotein that is highly expressed in prostate cancer but has limited expression in normal tissues. PSMA-TTC (227Th-pelgifatamab corixetan; BAY 2315497) consists of the alpha emitter thorium-227 complexed to a 3,2-HOPO chelator conjugated to a PSMA targeting antibody. PSMA-TTC delivers potent radiation to PSMA expressing cells. Here we evaluated the efficacy of PSMA-TTC in combination with darolutamide, a novel AR inhibitor in a hormone insensitive prostate cancer model and investigated the mode of action of the combination treatment. In vitro, darolutamide induced the expression of PSMA in the androgen-independent cell lines C4-2 and 22Rv1 more than 3-fold and 2-fold, respectively. Expression of the apoptosis marker CDKN1A was significantly induced in the PSMA-TTC alone and in the combination group compared to vehicle. Expression of the DNA repair genes BRCA1, XRCC2 and XRCC3 were significantly reduced in PSMA-TTC alone and in the combination group compared to vehicle. In vivo, a single i.v. injection of PSMA-TTC at 300 kBq/kg resulted in a tumor/control (T/C) ratio of 0.44 on day 19 in the 22Rv1 hormone-insensitive prostate cancer model while a twice daily oral treatment with 100 mg/kg darolutamide showed a T/C ratio of 0.82. The combination of darolutamide and PSMA-TTC resulted in a higher efficacy with a T/C ratio of 0.27. Tumor area on day 19 after treatment was significantly reduced in the PSMA-TTC alone group and more so in the combination group, compared to vehicle. As expected, darolutamide alone was not efficacious in this hormone insensitive model. Nine out of 10 mice showed disease control (CR, PR or SD) in the combination group whereas no animals showed disease control in either of the monotherapy groups. This difference was significant by Fisher’s exact test analysis. Treatments were well tolerated with no significant changes in body weight in any of the treatment groups. Using the tumor dissociation kit Miltenyi individual tumor cells were isolated from darolutamide treated and untreated 22Rv1 xenograft tumors. FACS analysis showed a 50fold increase in PSMA expression in the darolutamide treated 22Rv1 tumors compared to vehicle treated animals. These data indicate that darolutamide induces PSMA expression in the hormone independent 22Rv1 model, which may have contributed to the stronger efficacy observed when combined with PSMA-TTC. Altogether these results support the further evaluation of darolutamide combination with PSMA radionuclides. Citation Format: Christoph Schatz, Urs Hagemann, Sabine Zitzmann-Kolbe, Bernard Haendler, Hartwig Hennekes, Stefanie Hammer, Arne Scholz. Darolutamide potentiates the antitumor efficacy of a PSMA-targeted thorium-227 conjugate (PSMA-TTC) in a hormone-independent prostate cancer model [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 3311.

Promoter Gene Methylation Regulates Clooxygenase-2 Expression in Androgen-Dependent and Independent Prostate Cancer Cells.

BackgroundClooxygenase-2 (COX-2) expression is overexpressed in human prostate cancer, and aberrant methylation of the COX-2 promoter has also been elucidated. However, how the methylation of CpG islands at COX-2 regulates its expression in prostate cancer is still unclear. We will determine the methylated 5′ CpG island of the COX-2 gene and its role in the expression of COX-2 in prostate androgen-dependent and androgen-independent cancer cells, LNCaP and DU145.MethodsWe used western blotting and quantitative reverse transcription polymerase chain reaction (qRT-PCR) to confirm the COX-2 expression in prostate cancer cell lines, including LNCaP (androgen-dependent) and DU145 (androgen-independent) cells. To investigate whether the COX-2 expression was regulated by the methylation status of the 5′ CpG island, we treated LNCaP and DU145 cells with the DNA methylation inhibitor, 5-aza-2′-deoxycytidine, and determined COX-2 expression in the treated/untreated cells by western blotting and qRT-PCR. Subsequently, bisulfite sequencing was performed to study the methylation sites in the treated/untreated cells. The effects of 5-aza-2′-deoxycytidine to cell proliferation, cell migration and cell cycle process in DU145 and LNCaP cells were determined using Cell Counting Kit-8 (CCK-8) assay, transwell assay and flow cytometry, respectively.ResultsThe results revealed that the expression of COX-2 in androgen-dependent LNCaP cells was 5.44-fold (in protein level) and 2.46-fold (in mRNA level) higher than that in androgen-independent DU145 cells. After 5-aza-2′-deoxycytidine treatment, COX-2 expression in DU145 cells was elevated significantly, but no change was found in LNCaP cells. The A and C regions of the COX-2 CpG island exhibited reduced methylation along with that an increased expression of COX-2 was noted in DU145 cell after 5-aza-2′-deoxycytidine treatment. Also, the treatment with 5-aza-2′-deoxycytidine inhibited cell proliferation, cell migration and influenced the cell cycle progression in both DU145 and LNCaP cells.ConclusionsOur results reveal that androgen receptor (AR)-dependent/independent prostate cancer cell lines exhibit different regulation of methylation in COX-2 that regulate its expression. Additionally, 5-aza-2′-deoxycytidine treatment of DU145 and LNCaP cells inhibits their ability of tumor progression.