Strategy For Prostate Cancer Research Articles

Androgen deprivation-induced senescence confers sensitivity to a senolytic strategy in prostate cancer

We have previously demonstrated that androgen-dependent prostate cancer (PCa) cell lines enter a state of senescence following exposure to androgen deprivation therapies (ADT). ADT-induced senescence was found to be transient, as senescent cells develop castration resistance and re-emerge into a proliferative state even under continuous androgen deprivation in vitro. Moreover, the BCL-XL/BCL-2 inhibitor, ABT-263 (navitoclax), an established senolytic agent, promoted apoptosis of senescent PCa cells, suppressing proliferative recovery and subsequent tumor cell outgrowth. As this strategy has not previously been validated in vivo, we used a clinically relevant, syngeneic murine model of PCa, where mice were either castrated or castrated followed by the administration of ABT-263. Our results largely confirm the outcomes previously reported in vitro; specifically, castration alone results in a transient tumor growth suppression with characteristics of senescence, which is prolonged by exposure to ABT-263. Most critically, mice that underwent castration followed by ABT-263 experienced a statistically significant prolongation in survival, with an increase of 14.5 days in median survival time (56 days castration alone vs. 70.5 days castration + ABT-263). However, as is often the case in studies combining the promotion of senescence with a senolytic (the “one-two” punch approach), the suppression of tumor growth by the inclusion of the senolytic agent was transient, allowing for tumor regrowth once the drug treatment was terminated. Nevertheless, the results of this work suggest that the “one-two” punch senolytic strategy in PCa may effectively interfere with, diminish, or delay the development of the lethal castration-resistant phenotype.

Abstract 6014: PLK1-dependent phosphorylation of PRMT5 promotes DNA damage response in prostate cancer

Abstract Prostate cancer stands out as the most frequently diagnosed cancer in men and is projected to be the second leading cause of cancer-related deaths among men in the US. Consequently, there is an urgent need for studies focusing on innovative therapeutic approaches. DNA Damage Response (DDR) is critical for cell survival, as it promotes genomic stability and reduces the risk of inheriting damage. DDR also promotes cancer cells' survival, making it a therapeutic target in cancer. PRMT5, an enzyme in the methyltransferase family, is frequently activated and overexpressed in various cancers, including prostate cancer. Furthermore, research has revealed that PRMT5 has been implicated in DDR in prostate cancer, and the regulation of PRMT5-dependent DDR is influenced by its phosphorylation. Polo-like kinase 1 (PLK1) is a serine/threonine kinase also reportedly involved in DDR in prostate cancer. Our preliminary study found that PRMT5 is positively correlated with PLK1 in prostate cancer based on the TCGA database. Nonetheless, the mechanism through which PRMT5 is regulated needs to be clarified. Here, we found that PLK1 phosphorylates PRMT5 at the S470 site, and this specific phosphorylation is required for maintaining the enzymatic activity of PRMT5. Moreover, Plk1-associated phosphorylation of PRMT5 subsequently promotes DNA damage repair, indicated by the decreasing level of γH2AX after DNA double-strand breaks (DSB). Our RNA-seq analyses of prostate cancer cells with wild-type or mutant S470 sites indicate that Plk1-associated phosphorylation on the S470 site exerts an influence on DNA replication and DDR pathways. These findings shed light on a novel perspective regarding the roles of PLK1-mediated PRMT5 phosphorylation in DDR, offering potential therapeutic strategies in prostate cancer. Citation Format: Jia Peng, Yanquan Zhang, Jianlin Wang, Qianjin Li, Daheng He, Xinyi Wang, Xiongjian Rao, Meng Wu, Pingli Mo, Lei Wang, Sai Wu, Ruixin Wang, Jinghui Liu, Mansoureh Nouri, Izumi Tadahide, Xiaoqi Liu. PLK1-dependent phosphorylation of PRMT5 promotes DNA damage response 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 6014.

Tumor-associated antigen targets for novel immune-based strategies in prostate cancer

Prostate cancer remains the most common malignancy among men in the United States. Advancements in androgen receptor signaling blockade have led to landmark approvals for its use in patients with locally advanced and metastatic disease. However, additional novel therapeutic strategies for both hormone-sensitive and castration-resistant diseases remain ongoing areas of study. Thus, we turn to the growth of immuno-oncology, which has led to improved treatment outcomes for a variety of hematologic and solid tumor malignancies. Prostate cancers have shown only modest results with immune checkpoint inhibition in published trials, and innovative strategies are now looking into enhancing cytotoxic T-cell activity against cancer cells. This review provides a thorough evaluation of tumor-associated antigens that are integrated into novel chimeric antigen receptor T-cell and bispecific T-cell engager therapies. Our review will evaluate the most recent advancements in immunotherapies, while also illustrating major obstacles and underlying limiting factors.

Making the Case for Autophagy Inhibition as a Therapeutic Strategy in Combination with Androgen-Targeted Therapies in Prostate Cancer.

Androgen receptor targeting remains the primary therapeutic strategy in prostate cancer, encompassing androgen biosynthesis inhibitors and androgen receptor antagonists. While both androgen-receptor-positive and "castration-resistant" prostate cancer are responsive to these approaches, the development of resistance is an almost inevitable outcome leading to the castration-resistant form of the disease. Given that "cytoprotective" autophagy is considered to be a predominant mechanism of resistance to various chemotherapeutic agents as well as to radiation in the cancer literature, the purpose of this review is to evaluate whether autophagy plays a central role in limiting the utility of androgen deprivation therapies in prostate cancer. Unlike most of our previous reports, where multiple functional forms of autophagy were identified, making it difficult if not impossible to propose autophagy inhibition as a therapeutic strategy, the cytoprotective form of autophagy appears to predominate in the case of androgen deprivation therapies. This opens a potential pathway for improving the outcomes for prostate cancer patients once effective and reliable pharmacological autophagy inhibitors have been developed.

Aptamer guided nanomedicine strategies in prostate cancer: Targeting and diagnosis

Prostate cancer (PCa) is the predominant cancer among men across the globe. Conventional therapies available for PCa suffer from limitations such as lack of target specificity, chemo-resistance, poor tumour extravasation and accumulation. Although ligand conjugated nanocarrier based-drug delivery strategies were well explored in literature, recent studies demonstrated that tumor accumulation of such actively targeted drug delivery systems is marginal (∼0.0014%). Therefore, there is a need for improved drug delivery interventions that improve tumor accumulation of nanocarriers. Aptamers possess a certain edge over other ligands owing to their target cell specificity and diminished immunogenic reactions. Further, development and evaluation of aptamers is relatively easy for therapeutic and/or diagnostic applications that in turn encourage aptamer based-drug discovery in pharmaceutical industry. Considering these factors, the authors discussed various biomarkers which could be used for aptamer development in targeting and diagnosis of PCa. Further, the authors mentioned nanocarrier functionalization aspects using aptamers and its role in enhancing prostate cancer-specific cellular uptake. In addition to aforementioned developmental aspects, the authors also highlighted potential bottlenecks that hinder the clinical translation of aptamer-functionalized nanomedicines.

Socioeconomic and demographic patterns associated with treatment delay in prostate cancer: An analysis of the National Cancer Database.

e17122 Background: Prostate cancer is the second leading cause of cancer related deaths in men. In 2023, about 288,300 new cases of prostate cancer are expected . Delays in cancer treatment can impact patients’ outcomes. In our study, we sought to describe socioeconomic and demographic factors influencing time to treatment in prostate cancer. We also studied the trend in time to treatment through the years. Methods: Using the National Cancer Database, we identified 1,605,396 patients diagnosed with prostate cancer between 2004 and 2019. Variables used for assessment include age at diagnosis, race, Charlson-Deyo score, stage at diagnosis, insurance status, median household income in patient’s zip code and year of treatment. We separated patients into two groups: those who started treatment < 60 days and patients who started treatment > 60 days using statistical analyses. We used Chi-square test to assess for differences within these groups and multivariable analysis to determine relationships between time to treatment and the socioeconomic and demographic variables. All tests were performed with a significance level of a = 0.05. Results: Out of 1,605,396 patients included in this study, 806,576 patients began treatment 60 days or less after diagnosis and 798,820 began treatment over 60 days after diagnosis. Older patients (age > 71) were less likely to be treated later than younger patients aged < 60 years (OR 0.530). Black and Hispanic patients were significantly more likely to start treatment later than white patients (OR 1.231; OR 1.086 p < 0.001). Compared to uninsured patients, those with private and other government coverage were more significantly likely to begin treatment later (OR 1.144; OR 1.469 p < 0.001). Patients with advanced stage prostate cancer were at lower risk for delayed treatment compared to those with localized disease (OR 0.218 P < 0.001). Compared to community programs, patients at academic/research programs were significantly more likely to begin treatment later (OR 2.097 p < 0.0001). In 2004, 40.5% patients began treatment over 60 days from diagnosis compared to 55.1% in 2019 (p < 0.001). We found that patients diagnosed between 2016 and 2019 were more likely to be treated later than those diagnosed between 2004-2007 (OR 1.717 p < 0.001). Conclusions: Increased rate of later time to treatment were seen in younger patients, minority groups, staging at diagnosis less than stage IV, patients treated at academic or research programs, and patients diagnosed between 2016-2019. This is likely due to the rise of active surveillance rather than immediate treatment as a management strategy in prostate cancer. Black men are at increased risk for advanced disease, hence, treatment delays should be avoided in these patients. Institution-level studies should be done to determine the pattern of treatment and address treatment delays.

Evaluation of Matrix Metalloproteases by Artificial Intelligence Techniques in Negative Biopsies as New Diagnostic Strategy in Prostate Cancer.

Usually, after an abnormal level of serum prostate-specific antigen (PSA) or digital rectal exam, men undergo a prostate needle biopsy. However, the traditional sextant technique misses 15-46% of cancers. At present, there are problems regarding disease diagnosis/prognosis, especially in patients' classification, because the information to be handled is complex and challenging to process. Matrix metalloproteases (MMPs) have high expression by prostate cancer (PCa) compared with benign prostate tissues. To assess the possible contribution to the diagnosis of PCa, we evaluated the expression of several MMPs in prostate tissues before and after PCa diagnosis using machine learning, classifiers, and supervised algorithms. A retrospective study was conducted on 29 patients diagnosed with PCa with previous benign needle biopsies, 45 patients with benign prostatic hyperplasia (BHP), and 18 patients with high-grade prostatic intraepithelial neoplasia (HGPIN). An immunohistochemical study was performed on tissue samples from tumor and non-tumor areas using specific antibodies against MMP -2, 9, 11, and 13, and the tissue inhibitor of MMPs -3 (TIMP-3), and the protein expression by different cell types was analyzed to which several automatic learning techniques have been applied. Compared with BHP or HGPIN specimens, epithelial cells (ECs) and fibroblasts from benign prostate biopsies before the diagnosis of PCa showed a significantly higher expression of MMPs and TIMP-3. Machine learning techniques provide a differentiable classification between these patients, with greater than 95% accuracy, considering ECs, being slightly lower when considering fibroblasts. In addition, evolutionary changes were found in paired tissues from benign biopsy to prostatectomy specimens in the same patient. Thus, ECs from the tumor zone from prostatectomy showed higher expressions of MMPs and TIMP-3 compared to ECs of the corresponding zone from the benign biopsy. Similar differences were found for expressions of MMP-9 and TIMP-3, between fibroblasts from these zones. The classifiers have determined that patients with benign prostate biopsies before the diagnosis of PCa showed a high MMPs/TIMP-3 expression by ECs, so in the zone without future cancer development as in the zone with future tumor, compared with biopsy samples from patients with BPH or HGPIN. Expression of MMP -2, 9, 11, and 13, and TIMP-3 phenotypically define ECs associated with future tumor development. Also, the results suggest that MMPs/TIMPs expression in biopsy tissues may reflect evolutionary changes from prostate benign tissues to PCa. Thus, these findings in combination with other parameters might contribute to improving the suspicion of PCa diagnosis.

WIN Symposium 2022 - Abstract Poster Presentations.

WIN Symposium 2022 - Abstract Poster Presentations.

Interleukin-1 receptor associated kinase 1 (IRAK1) is epigenetically activated in luminal epithelial cells in prostate cancer.

The use of immune adjuvants such as toll-like receptor (TLR) agonists reflects a novel strategy in prostate cancer (PCa) therapy. However, interleukin-1 receptor associated kinase 1 (IRAK1), a central effector of TLR signaling, has been shown to be responsible for resistance to radiation-induced tumor cell death. In order to better understand the function and epigenetic regulation of IRAK1 in PCa, we performed in vitro cell culture experiments together with integrative bioinformatic studies using the latest single-cell RNA-sequencing data of human PCa and normal prostate (NOR), and data from The Cancer Genome Atlas. We focused on key effectors of TLR signaling, the Myddosome-complex components IRAK1, IRAK4 and MYD88 (myeloid differentiation primary response 88), and TRAF6 (tumor-necrosis-factor receptor associated factor 6). In PCa, IRAK1-mRNA was specifically enriched in luminal epithelial cells, representing 57% of all cells, whereas IRAK4 and MYD88 were predominantly expressed in leukocytes, and TRAF6, in endothelial cells. Compared to NOR, only IRAK1 was significantly overexpressed in PCa (Benjamini-Hochberg adjusted p<2x10-8), whereas the expression of IRAK4, MYD88, and TRAF6 was unchanged in PCa, and IRAK1-expression was inversely correlated with a specific differentially methylated region (IRAK1-DMR) within a predicted promoter region enriched for H3K27ac (Spearman correlation r<-0.36; Fisher’s test, p<10-10). Transcription factors with high binding affinities in IRAK1-DMR were significantly enriched for canonical pathways associated with viral infection and carcinogenic transformation in the Kyoto Encyclopedia of Gene and Genomes analysis. DU145 cells, exhibiting hypermethylated IRAK1-DMR and low IRAK1-expression, reacted with 4-fold increased IRAK1-expression upon combined treatment with 5-aza-2-deoxycytidine and trichostatin A, and were unresponsive to infection with the uropathogenic Escherichia coli strain UTI89. In contrast, PC3 and LNCaP cells, exhibiting hypomethylated IRAK1-DMR and high endogenous IRAK1-mRNA levels, responded with strong activation of IRAK1-expression to UTI89 infection. In summary, exclusive overexpression of IRAK1 was observed in luminal epithelial cells in PCa, suggesting it has a role in addition to Myddosome-dependent TLR signaling. Our data show that the endogenous epigenetic status of PCa cells within IRAK1-DMR is decisive for IRAK1 expression and should be considered as a predictive marker when selective IRAK1-targeting therapies are considered.

1412P Immune changes after enzalutamide (Enza) is added to androgen-deprivation therapy (ADT) in first-line metastatic castration-resistant prostate cancer (mCRPC)

As previously reported, enza increases natural killer cells (NK) and decreases myeloid-derived suppressor cells (MDSCs) in biochemically recurrent (BCR) prostate cancer without ADT (Madan et al JITC, 2021). Enza’s immune impact in mCRPC with ADT has not been reported. This information could be important for developing new immunotherapy strategies in prostate cancer where PD1/PDL1 inhibition are not effective in unselected patients (pts).

Dietary stilbenes as modulators of specific miRNAs in prostate cancer.

Accumulated experimental data have suggested that natural plant products may be effective miRNA-modulating chemopreventive and therapeutic agents. Dietary polyphenols such as flavonoids, stilbenes, and lignans, among others, have been intensively studied for their miRNA-mediated cardioprotective, antioxidant, anti-inflammatory and anticancer properties. The aim of this review is to outline known stilbene-regulated miRNAs in cancer, with a special focus on the interplay between various miRNAs and MTA1 signaling in prostate cancer. MTA1 is an epigenetic reader and an oncogenic transcription factor that is overexpressed in advanced prostate cancer and metastasis. Not surprisingly, miRNAs that are linked to MTA1 affect cancer progression and the metastatic potential of cells. Studies led to the identification of MTA1-associated pro-oncogenic miRNAs, which are regulated by stilbenes such as resveratrol and pterostilbene. Specifically, it has been shown that inhibition of the activity of the MTA1 regulated oncogenic miR-17 family of miRNAs, miR-22, and miR-34a by stilbenes leads to inhibition of prostatic hyperplasia and tumor progression in mice and reduction of proliferation, survival and invasion of prostate cancer cells in vitro. Taken together, these findings implicate the use of resveratrol and its analogs as an attractive miRNA-mediated chemopreventive and therapeutic strategy in prostate cancer and the use of circulating miRNAs as potential predictive biomarkers for clinical development.

Novel germline mutations for active surveillance and imaging strategies in prostate cancer.

This review highlights the emerging role of genetics-lead medicine (GLM) in prostate cancer. We describe the benefits of GLM integration into prostate cancer screening, diagnosis and management. Imaging techniques enhancing prostate cancer detection are advancing concurrently, facilitating strategic active surveillance protocols for appropriately selected patients. We aim to improve clinician awareness of the role of GLM in current and future practice. We explore recent literature advancing the role of GLM in prostate cancer detection and management, particularly as this coexists with the development of imaging technology. Our current understanding of germline mutations implicated in familial prostate cancer development is summarized. We describe how these developments are being utilized to inform screening, surveillance and the development of novel therapies. We summarize current guidelines and explore factors inhibiting optimal implementation of recommendations in clinical practice. Integration and further development of genetics-lead medicine in the detection, surveillance and management of prostate cancer will improve clinical outcomes for men at risk of aggressive disease as a result of familial predispositions to prostate cancer. This review summarizes the pertinent developments in the field including improving clinician awareness to facilitate implantation of these strategies into current clinical practice.

Downregulation of PGM5 expression correlates with tumor progression and poor prognosis in human prostate cancer

Prostate cancer (PCa) is the most common malignancy in men in developed countries. Prostate-specific antigen (PSA) remains the most widely used serum marker for prostate cancer. Here, we reported that the expression of phosphoglucomutase-like protein 5 (PGM5) is significantly lower in prostate cancer tissue. The low expression of PGM5 and its related gene signature were found to be linked to poor clinical outcome and high Gleason score. In vitro assays showed that overexpression of PGM5 significantly repressed proliferation and migration of prostate cancer cells. GO and pathway analyses showed the enrichment of genes in regulation of cell growth and migration, and pathways related in cancer. Our additional results showed that the downregulation of PGM5 is closely related to DNA methylation. Taken together, our findings provide the first evidence that PGM5 expression is associated with prostate cancer progression. These results also highlight a preclinical rationale that PGM5 represents a prognostic marker and a promising target for new therapeutic strategies in prostate cancer.

Abstract 5577: PSMA targeting CAR T cell immunotherapeutic strategy for prostate cancer

Abstract Introduction: Prostate cancer is the third most frequent cause of cancer-related death in men worldwide. Since prostate-specific membrane antigen (PSMA) shows a significant overexpression on prostatic cancer cells, PSMA can be considered a promising target for prostate cancer imaging and treatment. Although chimeric antigen receptor (CAR) T cells have shown great clinical outcomes in hematological malignancies, there is still limited efficacy in solid tumors due to the lack of tumor-specific antigens, low T cell infiltration in the tumors, immune suppressive tumor microenvironment, and on-target off-tumor toxicity in healthy tissues. The antigen recognition module of CAR T cells is usually a single-chain variable fragment (scFv). In contrast, the variable domains of heavy-chain antibodies (VHH) are small, stable, single-domain antibody fragments with high affinity and do not require the supramolecular assembly. Severe fatalities recently halted clinical trials of PSMA CAR T cells, so affinity tuning may be required to avoid CAR T targeting normal tissues. Here, we developed VHH-based CAR T cells targeting PSMA, able to co-express human somatostatin receptor 2 (SSTR2) actioning as a PET reporter for tracking CAR T cell distribution, as an immunotherapeutic strategy for prostate cancer. Methods: Primary human T cells were isolated and transduced with PSMA CAR lentivirus at 24 and 48 hours after activation with anti-CD3/CD28 Dynabeads. Mouse models of 8505C cell line transduced to overexpress PSMA were utilized to test the efficacy of CAR T cells. Tumor growth was monitored regularly by bioluminescence imaging. PET/CT imaging was performed to monitor T cell localization and biodistribution using ¹⁸F-NOTA-octreotide radiotracer targeting SSTR2 introduced in CAR T cells. Results: By alanine substitution of CDR3 in the VHH, we identified several low affinity candidates. The affinity of the VHH-based PSMA CAR was determined to be 22 nM by a saturation binding assay using monomeric human PSMA protein. PSMA CAR expression in primary human T cells was higher than 90%. Compared to non-treated mice, PSMA targeting CAR T cells led to tumor reduction and improved survival in animal models. Moreover, high levels of T cell infiltration and localization in tumor tissues were found, based on PET/CT imaging. Considering possible treatment-associated toxicities, which led to 2 patient deaths and the halt of one phase 1 trial of PSMA CAR T cells, we will affinity tune VHH-based CAR to improve the safety profile. Thus, additional studies will be performed to test both activity and safety of affinity variants of PSMA CAR T cells. Conclusions: We developed PSMA targeting CAR T cells able to induce potent and specific killing of prostate cancer cells. This strategy demonstrated significant therapeutic efficacy in vivo against animal models. Therefore, CAR T cells targeting PSMA may be a promising treatment strategy for patients with prostate cancer. Citation Format: Juan Gonzalez-Valdivieso, Yanping Yang, Yogindra Vedvyas, Yago Alcaina, Moonsoo M. Jin. PSMA targeting CAR T cell immunotherapeutic strategy for 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 5577.

The Aptamer Functionalized Nanocomposite Used for Prostate Cancer Diagnosis and Therapy

Prostate cancer is one of the major malignancies that threaten men’s health all over the world. Due to the lack of specific symptoms and signs in the early stage, as well as the limitations of existing detection methods, it is difficult to achieve early diagnosis for prostate cancer. As short single‐stranded oligonucleotides (DNA or RNA) with specific 3D structure which can be produced using an in vitro selection process termed systematic evolution of ligands by exponential enrichment (SELEX), aptamers can specifically bind to the corresponding targets. They have become a class of novel targeting ligand for accurate diagnosis and effective treatment of cancer. Owing to distinctive physicochemical features, and some other special properties such as easy modifiability, good biocompatibility, being easily coupled with other ligands, nanomaterials are extensively used in biological medical field research. Enlighteningly, the combination of aptamers with nanomaterials, including metal nanoparticles, nanosilica, quantum dots, and carbon nanomaterials, can enhance the ability of nanomaterials to recognize tumor cells, which is beneficial to overcome the shortcomings such as low sensitivity in early detection and lack of specificity of traditional antineoplastic drugs, thus, clinically helpful to improve the early metaphase diagnosis rate, providing a technical guarantee for the “personalized treatment” strategy for prostate cancer. Herein, we mainly review the basic and applied research of aptamer functionalized nanocomposite in prostate cancer diagnosis and treatment, including biosensing, bioimaging, and cancer therapy, hoping to provide new ideas for prostate cancer diagnosis and treatment.

Attitudes, practices and perspectives on imaging strategies in prostate cancer: a national cross-sectional survey involving expert radiation oncologists on behalf of AIRO (Italian association of radiotherapy and clinical oncology) GU group.

Although high sensitive imaging modalities such as MRI and PSMA PET/CT are becoming available for prostate cancer (PCa), the clinical benefit of an earlier detection of subclinical disease remains yet undetermined. Given these uncertainties, univocal recommendations are often lacking. The present survey was therefore developed by the Italian Association of Radiotherapy and Clinical Oncology (AIRO) to collect the opinion of expert radiation oncologists and delineate a representation of current clinical practice in our country. A nationwide cross-sectional survey was conducted in Italy by administering an anonymous questionnaire to experienced radiation oncologists, representative of the genitourinary (GU) tumor board at their Institution, using the cloud-based platform SurveyMonkey®. For each question, a consensus was achieved when ≥ 75% of the responders agreed on the same response. Thirty nine AIRO members from different Italian centers who were deemed experts in GU field accessed the proposed survey and completed all sections. Explored topics included staging of organ-confined disease, management of biochemical and local recurrence, imaging in the metastatic setting, imaging following metastasis-directed therapy (MDT), and future considerations. Response rate for single item of the questionnaire ranged between 51.2% and 100%. Expert GU AIRO members agree that advanced molecular and functional imaging are expanding their role in local and distant staging of PCa, as well as in the oncologic management and in the assessment of treatment response. However, many controversial issues still exist on the best timing for a diagnostic evaluation and the most appropriate imaging to aim at this purpose.

Heterogeneity in Radiotherapeutic Parameter Assumptions in Cost-Effectiveness Analyses in Prostate Cancer: A Call for Uniformity

ObjectivesCost-effectiveness analyses (CEAs) may provide useful data to inform management decisions depending on the robustness of a model’s input parameters. We sought to determine the level of heterogeneity in health state utility values, transition probabilities, and cost estimates across published CEAs assessing primarily radiotherapeutic management strategies in prostate cancer. MethodsWe conducted a systematic review of prostate cancer CEAs indexed in MEDLINE between 2000 and 2018 comparing accepted treatment modalities across all cancer stages. Search terms included “cost effectiveness prostate,” “prostate cancer cost model,” “cost utility prostate,” and “Markov AND prostate AND (cancer OR adenocarcinoma).” Included studies were agreed upon. A Markov model was designed using the parameter estimates from the systematic review to evaluate the effect of estimate heterogeneity on strategy cost acceptability. ResultsOf 199 abstracts identified, 47 publications were reviewed and 37 were included; 508 model estimates were compared. Estimates varied widely across variables, including gastrointestinal toxicity risk (0%-49.5%), utility of metastatic disease (0.25-0.855), intensity-modulated radiotherapy cost ($21 193-$61 996), and recurrence after external-beam radiotherapy (1.5%-59%). Multiple studies assumed that different radiotherapy modalities delivering the same dose yielded varying cancer control rates. When using base estimates for similar parameters from included studies, the designed model resulted in 3 separate acceptability determinations. ConclusionsSignificant heterogeneity exists across parameter estimates used to perform CEAs evaluating treatment for prostate cancer. Heterogeneity across model inputs yields variable conclusions with respect to the favorability and cost-effectiveness of treatment options. Decision makers are cautioned to review estimates in CEAs to ensure they are up to date and relevant to setting and population.

Metformin exerts anti-AR-negative prostate cancer activity via AMPK/autophagy signaling pathway

BackgroundEncouraged by the goal of developing an effective treatment strategy for prostate cancer, this study explored the mechanism involved in metformin-mediated inhibition of AR-negative prostate cancer.MethodsCell behaviors of DU145 and PC3 cells were determined by CCK8 test, colony formation experiment and scratch test. Flow cytometry was used to detect cell cycle distribution. Cell autophagy was induced with metformin, and an autophagy inhibitor, 3-MA, was used to assess the level of autophagy. Detection of LC3B by immunofluorescence was conducted to determine autophagy level. Cell proliferation, autophagy and cell cycle were examined by performing Western blot. DU145 and PC3 cell lines were transfected with AMPK siRNA targeting AMPK-α1 and AMPK-α2. Tumor formation experiment was carried out to evaluate the anti-prostate cancer effect of metformin in vivo.ResultsThe inhibitory effect of metformin on the proliferation of prostate cancer cell lines was confirmed in this study, and the mechanism of such an effect was related to autophagy and the block of cell cycle at G0/G1 phase. Metformin also induced the activation of AMPK, markedly promoted expression of LC3II, and down-regulated the expression of p62/SQSTM1. Animal experiments showed that the tumor volume of metformin group was smaller, meanwhile, the levels of p-AMPK (Thr172) and LC3B were up-regulated and the Ki-67 level was down-regulated, without abnormalities in biochemical indicators.ConclusionThis study found that autophagy induction might be the mechanism through which metformin suppressed the growth of AR-negative prostate cancer. Moreover, the activation of AMPK/autophagy pathway might be a therapeutically effective for treating AR-negative prostate cancer in the future.

Epigenetics in prostate cancer: clinical implications.

Epigenetic alterations, including changes in DNA methylation, histone modifications and nucleosome remodeling, result in abnormal gene expression patterns that contribute to prostate tumor initiation and continue to evolve during the course of disease progression. Epigenetic modifications are responsible for silencing tumor-suppressor genes, activating oncogenic drivers, and driving therapy resistance and thus have emerged as promising targets for antineoplastic therapy in prostate cancer. In this review, we discuss the role of epigenetics in prostate cancer with a particular emphasis on clinical implications. We review how epigenetic regulators crosstalk with critical biological pathways, including androgen receptor signaling, and how these interactions dynamically control prostate cancer transcriptional profiles. Because of their potentially reversible nature, restoration of a "normal" epigenome could provide a basis for innovative therapeutic strategies in prostate cancer. We highlight how particular epigenetic alterations are emerging as potential diagnostic and prognostic biomarkers and/or targets for the treatment of advanced prostate cancer.

CDC2-like (CLK) protein kinase inhibition as a novel targeted therapeutic strategy in prostate cancer

Dysregulation of alternative splicing is a feature of cancer, both in aetiology and progression. It occurs because of mutations in splice sites or sites that regulate splicing, or because of the altered expression and activity of splice factors and of splice factor kinases that regulate splice factor activity. Recently the CDC2-like kinases (CLKs) have attracted attention due to their increasing involvement in cancer. We measured the effect of the CLK inhibitor, the benzothiazole TG003, on two prostate cancer cell lines. TG003 reduced cell proliferation and increased apoptosis in PC3 and DU145 cells. Conversely, the overexpression of CLK1 in PC3 cells prevented TG003 from reducing cell proliferation. TG003 slowed scratch closure and reduced cell migration and invasion in a transwell assay. TG003 decisively inhibited the growth of a PC3 cell line xenograft in nude mice. We performed a transcriptomic analysis of cells treated with TG003. We report widespread and consistent changes in alternative splicing of cancer-associated genes including CENPE, ESCO2, CKAP2, MELK, ASPH and CD164 in both HeLa and PC3 cells. Together these findings suggest that targeting CLKs will provide novel therapeutic opportunities in prostate cancer.