The Current Landscape of Treatment in Non-Metastatic Castration-Resistant Prostate Cancer

Cancer research in Lebanon: Scope of the most recent publications of an academic institution (Review)

Cancer may be considered one of the most interesting areas of study, and although oncology research has grown markedly over the last decade, there is as yet no known cure for cancer. The objective of the present review is to examine various approaches to cancer research from a single institution, summarize their key conclusions and offer recommendations for future evaluations. The review examined 72 cancer-associated studies that were published within six years from 2017 to 2022. Published works in the subject fields of 'cancer' or 'oncology' and 'research' that were indexed in Scopus and Web of Science were retrieved and sorted according to article title, author names, author count, citation count and key words. After screening, a total of 28 in vitro/animal studies and 46 patient-associated published studies were obtained. A large proportion of these studies comprised literature reviews (20/72), while 20 studies were observational in nature. The 72 publications included 23 in which various types of cancer were examined, while the remaining studies focused on specific types of cancer, including lung, breast, colon and brain cancer. These studies aimed to investigate the incidence, prevalence, treatment and prevention mechanisms associated with cancer. Despite the existence of extensive cancer research, scientists seldom contemplate an ultimate cure for cancer. However, it is crucial to continuously pursue research on cancer prevention and treatment in order to enhance the effectiveness and minimize potential side effects of cancer therapy.

Low-Dose Apalutamide in Nonmetastatic Castration-Resistant Prostate Cancer: A Case Report

The effect of low-dose apalutamide in nonmetastatic castration-resistant prostate cancer is unknown. We report the observation of therapy being administered at 25% of the recommended dose in an 80-year-old patient. Despite treatment discontinuation during COVID lockdowns, he survived three years without evidence of metastasis. This case gently invites us to reflect on the possibility of low-dose apalutamide in the elderly.

Improving the identification of high-risk non-metastatic castration-resistant prostate cancer patients in clinical practice

Non-metastatic castration-resistant prostate cancer (nmCRPC) represents a challenging disease state in prostate cancer care. nmCRPC patients with a high risk of progression to metastatic disease who are identified by a prostate-specific antigen doubling time (PSADT) ≤10 months are eligible for treatment with the novel androgen receptor inhibitors (ARIs), shown to delay disease progression and extend survival. However, nmCRPC is often unexploited in clinical practice due to a lack of standardization in the methodology and in the tools used for its identification. In this article, a group of Urology and Oncology specialists with acknowledged expertise in prostate cancer reviews the state of the art in the management of high-risk nmCRPC patients, identifies gaps and unmet needs, and proposes strategies to optimize the identification of this patient subgroup in the clinical practice and improve their health outcomes.

Longitudinal change in castration-resistant prostate cancer biomarker AST/ALT ratio reflects tumor progression

We investigated whether aspartate transaminase (AST)-to-alanine aminotransferase (ALT) ratio and its change during the course of treatment in castration-resistant prostate cancer (CRPC) patients is associated with tumor condition and lethality. Clinical data from 130 CRPC patients were retrospectively evaluated. AST/ALT ratios at the time of prostate cancer (PC) diagnosis, androgen deprivation therapy (ADT), CRPC diagnosis, and the final follow-up examination after CRPC treatment were calculated for each. The prognostic capabilities of the AST/ALT ratio for overall survival (OS) were analyzed by use of the Kaplan-Meier method and Cox hazard models. The median AST/ALT ratio at PC diagnosis was 1.517 and the optimal value predicting lethality defined by the receiver operating curve was 1.467. The AST/ALT ratio decreased once during ADT and then elevated in a stepwise manner with cancer progression. In surviving patients, the median AST/ALT ratio at the time of PC diagnosis was 1.423, which did not change longitudinally, whereas that in patients later deceased was significantly higher (1.620) and further elevated after CRPC diagnosis. Kaplan-Meier curves indicated significantly worse OS in patients with an AST/ALT ratio ≥ 1.467, which was confirmed by multivariate analysis. These findings indicate AST/ALT ratio as a prognostic biomarker for CRPC with longitudinal changes reflecting tumor progression.

siRNA-based approaches for castration-resistant prostate cancer therapy targeting the androgen receptor signaling pathway

Androgen deprivation therapy is a common treatment method for metastatic prostate cancer through lowering androgen levels; however, this therapy frequently leads to the development of castration-resistant prostate cancer (CRPC). This is attributed to the activation of the androgen receptor (AR) signaling pathway. Current treatments targeting AR are often ineffective mostly due to AR gene overexpression and mutations, as well as the presence of splice variants that accelerate CRPC progression. Thus there is a critical need for more specific medication to treat CRPC. Small interfering RNAs have shown great potential as a targeted therapy. This review discusses prostate cancer progression and the role of AR signaling in CRPC, and proposes siRNA-based targeted therapy as a promising strategy for CRPC.

Safety differences across androgen receptor inhibitors in nonmetastatic castration-resistant prostate cancer

Approval of apalutamide, enzalutamide and darolutamide has transformed the treatment landscape and guideline recommendations for patients with nonmetastatic castration-resistant prostate cancer but now raises the issue of decision-making regarding treatment selection. In this commentary, we discuss the efficacy and safety of these second-generation androgen receptor inhibitors and propose that for patients with nonmetastatic castration-resistant prostate cancer, safety considerations for these treatments are especially important. We examine these considerations in the context of patient and caregiver preferences as well as patient clinical characteristics. We further posit that consideration of treatments' safety profiles should include not only the initial direct impacts from potential treatment-emergent adverse events and drug-drug interaction events, but also the full cascade of potentially avoidable healthcare complications.

Artepillin C overcomes apalutamide resistance through blocking androgen signaling in prostate cancer cells

Prostate cancer has a relatively good prognosis, but most cases develop resistance to hormone therapy, leading to castration-resistant prostate cancer (CRPC). Androgen receptor (AR) antagonists and a cytochrome P450 17A1 inhibitor have been used to treat CRPC, but cancer cells readily develop resistance to these drugs. In this study, to improve the therapy of CRPC, we searched for natural compounds which block androgen signaling. Among cinnamic acid derivatives contained in Brazilian green propolis, artepillin C (ArtC) suppressed expressions of androgen-induced prostate-specific antigen and transmembrane protease serine 2 in a dose-dependent manner. Reporter assays revealed that ArtC displayed AR antagonist activity, albeit weaker than an AR antagonist flutamide. In general, aberrant activation of the androgen signaling is involved in the resistance of prostate cancer cells to hormone therapy. Recently, apalutamide, a novel AR antagonist, has been in clinical use, but its drug-resistant cases have been already reported. To search for compounds which overcome the resistance to apalutamide, we established apalutamide-resistant prostate cancer 22Rv1 cells (22Rv1/APA). The 22Rv1/APA cells showed higher AR expression and androgen sensitivity than parental 22Rv1 cells. ArtC inhibited androgen-induced proliferation of 22Rv1/APA cells by suppressing the enhanced androgen signaling through blocking the nuclear translocation of AR. In addition, ArtC potently sensitized the resistant cells to apalutamide by inducing apoptotic cell death due to mitochondrial dysfunction. These results suggest that the intake of Brazilian green propolis containing ArtC improves prostate cancer therapy.

Antiandrogenic Effects of a Polyphenol in Carex kobomugi through Inhibition of Androgen Synthetic Pathway and Downregulation of Androgen Receptor in Prostate Cancer Cell Lines

Prostate cancer (PC) represents the most common cancer disease in men. Since high levels of androgens increase the risk of PC, androgen deprivation therapy is the primary treatment; however this leads to castration-resistant PC (CRPC) with a poor prognosis. The progression to CRPC involves ectopic androgen production in the adrenal glands and abnormal activation of androgen signaling due to mutations and/or amplification of the androgen receptor (AR) as well as activation of androgen-independent proliferative pathways. Recent studies have shown that adrenal-derived 11-oxygenated androgens (11-ketotestosterone and 11-ketodihydrotestosterone) with potencies equivalent to those of traditional androgens (testosterone and dihydrotestosterone) are biomarkers of CRPC. Additionally, dehydrogenase/reductase SDR family member 11 (DHRS11) has been reported to be a 17β-hydroxysteroid dehydrogenase that catalyzes the production of the 11-oxygenated and traditional androgens. This study was conducted to evaluate the pathophysiological roles of DHRS11 in PC using three LNCaP, C4-2 and 22Rv1 cell lines. DHRS11 silencing and inhibition resulted in suppression of the androgen-induced expression of AR downstream genes and decreases in the expression of nuclear AR and the proliferation marker Ki67, suggesting that DHRS11 is involved in androgen-dependent PC cell proliferation. We found that 5,7-dihydroxy-8-methyl-2-[2-(4-hydroxyphenyl)ethenyl]-4H-1-benzopyran-4-one (Kobochromone A, KC-A), an ingredient in the flowers of Carex kobomugi, is a novel potent DHRS11 inhibitor (IC₅₀ = 0.35 μM). Additionally, KC-A itself decreased the AR expression in PC cells. Therefore, KC-A suppresses the androgen signaling in PC cells through both DHRS11 inhibition and AR downregulation. Furthermore, KC-A enhanced the anticancer activity of abiraterone, a CRPC drug, suggesting that it may be a potential candidate for the development of drugs for the prevention and treatment of CRPC.

A systematic review and meta-analysis on non-metastatic castration resistant prostate cancer: The radiation oncologist's perspective

Prostate cancer is the second most common cause of cancer-related mortality in men. In patients undergoing a failure after radical treatment, one of the therapeutic option is androgen deprivation: despite initial response rates, a progression to a state of castration resistance is observed in most of the patients. In the present article, we conducted a systematic review and meta-analysis of all clinical trials assessing treatment for nmCRPC with next-generation androgen receptor inhibitors. We performed a review and meta-analysis of phase III randomized controlled trials comparing new agents (apalutamide, enzalutamide, darolutamide) with placebo as control arm, in the setting of nmCRPC. Patients treated with next-generation ARIs had a 26% reduction in the risk of death compared with placebo; compared with other ARIs, darolutamide had the lowest rate of grade 3 and 4 AEs and the lowest therapy discontinuation rate due to any grade AEs. This meta-analysis shows that treatment with new ARIs is safe and significantly reduces the risk of death and of metastasis onset in nmCRPC patients. Under way studies on new biomarkers such as genomic classifiers will probably allow the stratification in more specific subsets of disease. New imaging modalities such as PSMA-PET have shown greater sensibility and specificity than conventional imaging in metastases detection. All patients were randomized in a 2:1 fashion, with a total of 2,694 who underwent next-generation ARIs (806 apalutamide, 955 darolutamide, 933 enzalutamide) and 1,423 in the placebo arm.

Non-metastatic castration-resistant prostate cancer: the evolving treatment landscape and role of nurse specialists

Prostate cancer is the most common type of cancer in men in the UK. Within 2 years of diagnosis, one-third of patients with non-metastatic castration-resistant prostate cancer (nmCRPC) will develop metastatic disease, which is associated with significantly greater morbidity and mortality compared to disease without metastases. The approval of second-generation androgen receptor inhibitors such as darolutamide has transformed the nmCRPC treatment landscape because they lead to prolonged metastasis-free survival and better maintenance of quality of life compared with placebo. Early identification of patients with nmCRPC who are suitable for treatment is imperative because most of these patients are asymptomatic. Clinical nurse specialists (CNSs) play a critical, supportive role in the management of disease and treatment follow-up. This product-focused article discusses the use of darolutamide in nmCRPC and the vital role that CNSs play in the management and care of patients with prostate cancer.

Based on network pharmacology and molecular docking to predict the mechanism of Huangqi in the treatment of castration-resistant prostate cancer

Background

As a kind of traditional Chinese medicine, HQ is widely mentioned in the treatment of cancerous diseases in China, which has been proven to have a therapeutic effect on cancerous diseases, such as prostate cancer. To predict the specific mechanism of HQ in the treatment of CRPC, we will conduct preliminary verification and discussion based on a comprehensive consideration of network pharmacology and molecular docking.

Methods

TCMSP was used to obtain the compounds and reach the effective targets of HQ. The targets of CRPC were reached based on GeneCards database and CTD database. GO and KEGG were utilized for the analysis of overlapping targets. The software of Openbabel was used to convert the formats of ligands and reporters. In addition, molecular docking studies were performed by using the software of Autodock Vina.

Result

It can be seen from the database results that there were 87 active compounds (20 key active compounds) in HQ, and 33 targets were screened out for CRPC treatment. GO and KEGG pathway enrichment analyses identified 81 significant GO terms and 24 significant KEGG pathways. There is a difference in terms of the expression of core protein between cancer patients and healthy people. The expression of core protein in patients also has an impact on the life cycle. The results of molecular docking showed that the docking activity of drug molecules and core proteins was better.

Conclusions

It is concluded from the results of this network pharmacology and molecular docking that HQ makes a multi-target and multi-biological process, and results in the multi-channel synergistic effect on the treatment of CRPC by regulating cell apoptosis, proliferation and metastasis, which still needs further verification by experimental research.

Patterns of care for non‐metastatic castration‐resistant prostate cancer: A population‐based study

Objectives

To describe patterns of practice of PSA testing and imaging for Ontario men receiving continuous ADT for the treatment of non‐metastatic castration‐resistant prostate cancer (nmCRPC).

Patients and Methods

This was a retrospective, longitudinal, population‐based study of administrative health data from 2008 to 2019. Men 65 years and older receiving continuous androgen deprivation therapy (ADT) with documented CRPC were included. An administrative proxy definition was applied to capture patients with nmCRPC and excluded those with metastatic disease. Patients were indexed upon progression to CRPC and were followed until death or end of study period to assess frequency of monitoring with PSA tests and conventional imaging. A 2‐year look‐back window was used to assess patterns of care leading up to CRPC as well as baseline covariates.

Results

At a median follow‐up of 40.1 months, 944 patients with nmCRPC were identified. Their median time from initiation of continuous ADT to CRPC was 26.0 months. 60.7% of patients had their PSA measured twice or fewer in the year prior to index, and 70.7% patients did not receive any imaging in the year following progression to CRPC. Throughout the study period, 921/944 (97.6%) patients with CRPC progressed to high‐risk (HR‐CRPC) with PSA doubling time ≤ 10 months, of which more than half received fewer than three PSA tests in the year prior to developing HR‐CRPC, and 30.9% received no imaging in the subsequent year.

Conclusion

PSA testing and imaging studies are underutilized in a real‐world setting for the management of nmCRPC, including those at high risk of developing metastatic disease. Infrequent monitoring impedes proper risk stratification, disease staging and detection of treatment failure and/or metastases, thereby delaying the necessary treatment intensification with life‐prolonging therapies. Adherence to guideline recommendations and the importance of timely staging should be reinforced to optimize patient outcomes.

Apalutamide Compared with Darolutamide for the Treatment of Non-metastatic Castration-Resistant Prostate Cancer: Efficacy and Tolerability in a Matching-Adjusted Indirect Comparison

Introduction

Apalutamide and darolutamide are next-generation androgen receptor inhibitors that have demonstrated superior efficacy compared to placebo in men with non-metastatic castration-resistant prostate cancer (nmCRPC) receiving androgen deprivation therapy (ADT). In the absence of head-to-head studies, the present study sought to indirectly compare the efficacy and tolerability between these two treatments.

Methods

This anchored matching-adjusted indirect comparison (MAIC) used patient-level data from the phase 3, randomized, controlled SPARTAN study (apalutamide + ADT), weighted to match aggregate published data from the ARAMIS study (darolutamide + ADT) for clinically relevant baseline measures. Hazard ratios (HR) and 95% credible intervals (CrI) were estimated for efficacy endpoints: metastasis-free survival (MFS), prostate-specific antigen (PSA) progression, progression-free survival (PFS), and overall survival (OS). Odds ratios were estimated for tolerability outcomes: adverse events and serious adverse events.

Results

Before weighting, baseline characteristics from SPARTAN versus ARAMIS were different for median PSA (7.8 vs. 9.2 ng/mL), Eastern Cooperative Oncology Group performance status of 1 (23% vs. 31%), use of bone-targeted agents (10% vs. 4%), median time from initial diagnosis (94.9 vs. 85.4 months), and proportion of patients from North America (35% vs. 12%) and Europe (50% vs. 64%). After matching (n = 455), our analysis demonstrated that apalutamide + ADT had a Bayesian probability of being more effective than darolutamide + ADT for MFS [98.3%; HR 0.70 (95% CrI 0.51, 0.98)], PSA progression [~ 100%; HR 0.46 (95% CrI 0.33, 0.64)], and PFS [93.2%; HR 0.79 (95% CrI 0.59, 1.08)]. Results for OS and tolerability were similar between apalutamide + ADT and darolutamide + ADT.

Conclusion

This anchored MAIC analysis of pivotal phase 3 studies in patients with nmCRPC suggests that apalutamide + ADT is more effective than darolutamide + ADT for MFS, progression-free survival (PFS), and prostate-specific antigen (PSA) progression, with a similar OS benefit and tolerability profile.

Trial Registration

ARAMIS ClinicalTrials.gov number: NCT02200614; SPARTAN ClinicalTrials.gov number: NCT01946204.

Efficacy and safety of bipolar androgen therapy in castration-resistant prostate cancer following abiraterone or enzalutamide resistance: A systematic review

Bipolar androgen therapy (BAT) is a new endocrinologic treatment for castration-resistant prostate cancer (CRPC) that can restore some patients' sensitivity to drugs such as abiraterone (Abi) and enzalutamide (Enz). We performed a meta-analysis using STATA16. Sensitivity analyses were performed by examining the effects of individual studies using different effect models and detecting any publication bias using the Harbord test. In a total of 108 unique records, ten studies were included in the final meta-analysis. Participants who underwent BAT achieved a PSA50 response rate of 27% (95%CI [0.22,0.31], I2=17.98%), ORR of 34% (95%CI [0.24,0.43], I2=0), and incidence of AEs (grade≥3) of 14% (95%CI [0.09,0.19], I2=0). Patients who completed BAT proceeded to AR-targeted therapy (Abi or Enz) and achieved a PSA50 response rate of 57% (95% CI [0.36,0.78], I2=0). Patients with prior Enz resistance had a stronger impact on the PSA50 of AR-target therapy rechallenge. The results of this meta-analysis indicate that BAT is a safe and effective treatment for patients who have progressed after Abi or Enz. BAT can trigger the resensitization of patients with CRPC to subsequent endocrine therapy and improve the overall survival of patients and their quality of life.

Patterns of Care and Outcomes for Non-Metastatic Prostate Cancer in the United States: Results of the CancerMPact® Survey 2018

Purpose

We describe patterns of care and treatment outcomes for non-metastatic PCa (nmPCA), either hormone-sensitive or castration-resistant, in the United States of America (USA) in 2018.

Methods

A survey (CancerMPact^®) recruited physicians nationwide to answer an online questionnaire about how they treated patients with nmPCA. Questions covered aspects of treatment at all disease stages. Board-certified urologists and oncologists with at least five years of clinical practice and who treated at least 30 PCa patients monthly were included.

Results

The survey included responses from ninety-four physicians with an average of 17.5 years of clinical practice, who had treated a combined average of 4415 patients with nmPCA per month in 2018. Approximately 40% of patients in stage I were managed with either active surveillance or observation/no therapy, decreasing to 20%, 8% and 6% in stages II, III and IV(M0), respectively. Intensity-modulated radiotherapy was favored over other radiotherapy modalities, with rates of use ranging between 60% and 69% depending on disease stage. Leuprolide as monotherapy or in combination with enzalutamide, abiraterone or bicalutamide were the most common systemic treatment options for non-metastatic hormone-sensitive PCa (nmHSPC) patients with the first or second recurrence. Only 16.5% of non-metastatic castration-resistant PCa (nmCRPC) patients did not relapse within five years of initial therapy for nmCRPC.

Conclusion

While PCa treatment recommendations are rapidly changing due to advances in treatment, we observed great concordance between their most current versions and real-world data treatment patterns reported by US physicians.

Clinical characteristics and outcomes for patients with non‑metastatic castration-resistant prostate cancer

This study used linked, routinely-collected datasets to explore incidence, clinical characteristics and outcomes of prostate cancer (PC) patients who experience a rise in prostate-specific antigen (PSA) levels despite androgen deprivation therapy (ADT), without evidence of metastases in their patient record, termed non-metastatic castration-resistant PC (nmCRPC). Routinely collected administrative data in Wales were used to identify patients diagnosed with PC and nmCRPC from 2000-2015. Logrank tests and Cox proportional hazard models were used to compare time-to-events across subgroups defined by PSA doubling time and age. Of 38,021 patients identified with PC, 1,465 met nmCRPC criteria. PC incidence increased over the study period, while nmCRPC categorizations reduced. Median time from PC diagnosis to nmCRPC categorization was 3.07 years (95% confidence interval [CI] 2.91-3.26) and from nmCRPC categorization to metastases/death was 2.86 years (95% CI 2.67-3.09). Shorter PSA doubling time (≤ 10 months, versus > 10 months) was associated with reduced time to metastases or death (2.11 years [95% CI 1.92-2.30] versus 5.22 years [95% CI 4.87-5.51]). Age was not significantly associated with time to metastases/death. Our findings highlight key clinical characteristics and outcomes for patients with nmCRPC prior to the introduction of recently approved treatments.

Treatment and trials in non-metastatic castration-resistant prostate cancer

Metastatic prostate cancer is associated with considerable morbidity and mortality. Standard treatment for non-metastatic prostate cancer, to prevent metastatic progression, is androgen deprivation therapy (ADT); however, many patients will eventually develop castration-resistant prostate cancer (CRPC), which can prove challenging to treat. Between the stages of non-metastatic androgen-sensitive disease and metastatic CRPC is an intermediate disease state that has been termed non-metastatic CRPC (nmCRPC), which is a heterogeneous, man-made disease stage that occurs after a patient who has no radiological evidence of metastasis shows evidence of cancer progression even after ADT. Awareness of nmCRPC has risen owing to an increased use of ADT and its eventual failure. Men with nmCRPC are at a high risk of progression to mCRPC, with historically few options to halt this process. However, in the past two decades, multiple therapies have been investigated for the treatment of nmCRPC, including endothelin receptor antagonists and bone-targeted therapies, but none has changed the standard of care. In the past decade, the efficacy of androgen receptor pathway-targeting modalities has been investigated. Three novel nonsteroidal antiandrogen agents for treating high-risk nmCRPC have been investigated; the PROSPER, SPARTAN and ARAMIS trials were phase III, randomized, placebo-controlled clinical trials that investigated the efficacy and safety of enzalutamide, apalutamide and darolutamide, respectively. All three therapeutics showed statistically significant improvements in metastasis-free survival, progression to antineoplastic therapy was lengthened and at final analysis, overall survival was significantly improved. The comparative efficacy and safety of all three agents has not yet been investigated in a comprehensive clinical trial, but approval of these medications by the FDA and other regulatory agencies means that providers now have three effective therapeutic options to augment ADT for patients with nmCRPC.

Novel Target Opportunities in Non-Metastatic Castrate Resistant Prostate Cancer

Nearly one third of men will incur biochemical recurrence after treatment for localized prostate cancer. Androgen deprivation therapy (ADT) is the therapeutic mainstay; however, some patients will transition to a castrate resistant state (castrate resistant prostate cancer, CRPC). Subjects with CRPC may develop symptomatic metastatic disease (mCRPC) and incur mortality several years later. Prior to metastatic disease, however, men acquire non-metastatic CRPC (nmCRPC) which lends the unique opportunity for intervention to delay disease progression and symptoms. This review addresses current therapies for nmCRPC, as well as novel therapeutics and pathway strategies targeting men with nmCRPC.

2020 Korean guidelines for the management of metastatic prostate cancer

In 2017, Korean Society of Medical Oncology (KSMO) published the Korean management guideline of metastatic prostate cancer. This paper is the 2nd edition of the Korean management guideline of metastatic prostate cancer. We updated recent many changes of management in metastatic prostate cancer in this 2nd edition guideline. The present guideline consists of the three categories: management of metastatic hormone sensitive prostate cancer; management of metastatic castration resistant prostate cancer; and clinical consideration for treating patients with metastatic prostate cancer. In category 1 and 2, levels of evidence (LEs) have been mentioned according to the general principles of evidence-based medicine. And grades of recommendation (GR) was taken into account the quality of evidence, the balance between desirable and undesirable effects, the values and preferences, and the use of resources and GR were divided into strong recommendations (SR) and weak recommendations (WR). A total of 16 key questions are selected. And we proposed recommendations and described key evidence for each recommendation. The treatment landscape of metastatic prostate cancer is changing very rapid and many trials are ongoing. To verify the results of the future trials is necessary and should be applied to the treatment for metastatic prostate cancer patients in the clinical practice. Especially, many prostate cancer patients are old age, have multiple underlying medical comorbidities, clinicians should be aware of the significance of medical management as well as clinical efficacy of systemic treatment.

Design, synthesis and evaluation of novel enzalutamide analogues as potential anticancer agents

The androgen receptor inhibitor, Enzalutamide, proved effective against castration resistance prostate cancer, has demonstrated clinical benefits and increased survival rate in men. However, AR mutation (F876L) converts Enzalutamide from antagonist to agonist indicating a rapid evolution of resistance. Hence, our goal is to overcome this resistance mechanism by designing and developing novel Enzalutamide analogues. We designed a dataset of Enzalutamide derivatives using Enzalutamide's shape and electrostatic features to match with pharmacophoric features essential for tight binding with the androgen receptor. Based on this design strategy ten novel derivatives were selected including 5,5-dimethyl-3-(6-substituted benzo[d]thia/oxazol-2-yl)-2-thioxo-1-(4-(trifluoromethyl)pyridin-2-yl)imidazolidin-4-one (6a-j) for synthesis. All the compounds were evaluated in-vitro on prostate cancer cell lines DU-145, LNCaP and PC3. Interestingly, two compounds 3-(6-hydroxybenzo[d]thiazol-2-yl)-5,5-dimethyl-2-thioxo-1-(4-(trifluoromethyl)pyridin-2-yl) imidazolidin-4-one (6c, IC50 - 18.26 to 20.31μM) and 3-(6-hydroxybenzo[d]oxazol-2-yl)-5,5-dimethyl -2-thioxo- 1- (4-(trifluoromethyl) pyridin-2-yl)imidazolidin-4-one (6h, IC50 - 18.26 to 20.31μM) were successful with promising in-vitro antiproliferative activity against prostate cancer cell lines. The binding mechanism of potential androgen receptor inhibitors was further studied by molecular docking, molecular dynamics simulations and MM-GBSA binding free energy calculations and found in agreement with the in vitro studies. It provided strong theoretical support to our hypothesis.

Glutaminolysis is a metabolic route essential for survival and growth of prostate cancer cells and a target of 5α-dihydrotestosterone regulation

PURPOSE

Resistance to androgen-deprivation therapies and progression to so-called castrate-resistant prostate cancer (CRPC) remain challenges in prostate cancer (PCa) management and treatment. Among other alterations, CRPC has been associated with metabolic reprogramming driven by androgens. Here, we investigated the role of androgens in regulating glutaminolysis in PCa cells and determined the relevance of this metabolic route in controlling the survival and growth of androgen-sensitive (LNCaP) and CRPC (DU145 and PC3) cells.

METHODS

PCa cells (LNCaP, DU145 and PC3) and 3-month old rats were treated with 5α-dihydrotestosterone (DHT). Alternatively, LNCaP cells were exposed to the glutaminase inhibitor BPTES, alone or in combination with the anti-androgen bicalutamide. Biochemical, Western blot and extracellular flux assays were used to evaluate the viability, proliferation, migration and metabolism of PCa cells in response to DHT treatment or glutaminase inhibition.

RESULTS

We found that DHT up-regulated the expression of the glutamine transporter ASCT2 and glutaminase, both in vitro in LNCaP cells and in vivo in rat prostate cells. BPTES diminished the viability and migration of PCa cells, while increasing caspase-3 activity. CRPC cells were found to be more dependent on glutamine and more sensitive to glutaminase inhibition. BPTES and bicalutamide co-treatment had an additive effect on suppressing LNCaP cell viability. Finally, we found that inhibition of glutaminolysis differentially affected glycolysis and lipid metabolism in both androgen-sensitive and CRPC cells.

CONCLUSION

Our data reveal glutaminolysis as a central metabolic route controlling PCa cell fate and highlight the relevance of targeting glutaminase for CRPC treatment.

Treatment of non-metastatic castration resistant prostate cancer in 2020: What is the best?

Lately the development of 3 novel second-generation androgen receptor antagonists (enzalutamide, apalutamide, and darolutamide) chanced the treatment landscape of nonmetastatic castration-resistant prostate cancer. After proofing their clinical efficacy in large phase III registration trials with good compatibilities and tolerable side effects currently all 3 substances are Food and Drug Administration-approved in nonmetastatic castration-resistant prostate cancer. The present short review article provides an overview about these new treatment options and discusses their use in daily routine focusing on patient selection as well as on the impact of novel sensitive imaging modalities like prostate-specific membrane antigen-positron-emission tomography for detection of this stage of disease.