Metastatic Prostate Cancer-A Review of Current Treatment Options and Promising New Approaches

Oral docetaxel plus encequidar - A pharmacokinetic model and evaluation against IV docetaxel

The development of optimized dosing regimens plays a crucial role in oncology drug development. This study focused on the population pharmacokinetic modelling and simulation of docetaxel, comparing the pharmacokinetic exposure of oral docetaxel plus encequidar (oDox + E) with the standard of care intravenous (IV) docetaxel regimen. The aim was to evaluate the feasibility of oDox + E as a potential alternative to IV docetaxel. The article demonstrates an approach which aligns with the FDA's Project Optimus which aims to improve oncology drug development through model informed drug development (MIDD). The key question answered by this study was whether a feasible regimen of oDox + E existed. The purpose of this question was to provide an early GO / NO-GO decision point to guide drug development and improve development efficiency.

METHODS

 A stepwise approach was employed to develop a population pharmacokinetic model for total and unbound docetaxel plasma concentrations after IV docetaxel and oDox + E administration. Simulations were performed from the final model to assess the probability of target attainment (PTA) for different oDox + E dose regimens (including multiple dose regimens) in relation to IV docetaxel using AUC over effective concentration (AUCOEC) metric across a range of effective concentrations (EC). A Go / No-Go framework was defined-the first part of the framework assessed whether a feasible oDox + E regimen existed (i.e., a PTA ≥ 80%), and the second part defined the conditions to proceed with a Go decision.

RESULTS

 The overall population pharmacokinetic model consisted of a 3-compartment model with linear elimination, constant bioavailability, constant binding mechanics, and a combined error model. Simulations revealed that single dose oDox + E regimens did not achieve a PTA greater than 80%. However, two- and three-dose regimens at 600 mg achieved PTAs exceeding 80% for certain EC levels.

CONCLUSION

 The study demonstrates the benefits of MIDD using oDox + E as a motivating example. A population pharmacokinetic model was developed for the total and unbound concentration in plasma of docetaxel after administration of IV docetaxel and oDox + E. The model was used to simulate oDox + E dose regimens which were compared to the current standard of care IV docetaxel regimen. A GO / NO-GO framework was applied to determine whether oDox + E should progress to the next phase of drug development and whether any conditions should apply. A two or three-dose regimen of oDox + E at 600 mg was able to achieve non-inferior pharmacokinetic exposure to current standard of care IV docetaxel in simulations. A Conditional GO decision was made based on this result and further quantification of the "effective concentration" would improve the ability to optimise the dose regimen.

Development and validation of a sensitive LC-MS/MS assay of GT-14, a novel Gαi2 inhibitor, in rat plasma, and its application in pharmacokinetic study

A sensitive and selective LC-MS/MS method was developed and validated for the quantitation of a novel Gαi2 inhibitor, GT-14, in rat plasma using a SCIEX 6500+ triple QUAD LC-MS system equipped with an ExionLC UHPLC unit. GT-14 (m/z 265.2 → 134.1) and griseofulvin (Internal Standard, IS) (m/z 353.1 → 285.1) were detected in a positive mode by electrospray ionization (ESI) using multiple reaction monitoring (MRM). The assay was linear in the concentration range of 0.78-1000 ng/mL in rat plasma. Both accuracy and precision values were within the acceptance criteria of ±15 %, as established by FDA guidance. The matrix effect was negligible from plasma, with signal percentages of 98.5-106.9 %. The mean recovery was 104.5 %, indicating complete extraction of GT-14 from plasma. GT-14 was found to be stable under different experimental conditions. The validated method was successfully applied to evaluate plasma protein binding and in vivo pharmacokinetics of GT-14 in rats.

Characterizing disparities in receipt of palliative care for Asian Americans, Native Hawaiians, and Pacific Islanders with metastatic cancer in the United States

PURPOSE

Palliative care plays essential roles in cancer care. However, differences in receipt among individuals identifying as Asian American, Native Hawaiian, and Other Pacific Islanders (AA&NHPI) with cancer are not well-characterized, especially when these diverse groups are disaggregated. We characterized disparities in receipt of palliative care among AA&NHPI patients with AJCC Stage IV prostate, breast, or lung cancer.

METHODS

We performed multivariable logistic regressions were performed in this retrospective cohort analysis, using deidentified data from the National Cancer Database (NCDB) of patients diagnosed with AJCC analytic group stage IV breast, lung, or prostate cancer (2004-2018) who were White or of Asian Indian/Pakistani, Chinese, Filipino, Hawaiian, Hmong, Japanese, Kampuchean, Korean, Laotian, Other Pacific Islander, Thai, or Vietnamese descent. We conducted multivariable logistic regression analyses in a retrospective cohort study using deidentified data from the National Cancer Database (NCDB). The study included patients diagnosed with AJCC analytic group Stage IV breast, lung, or prostate cancer between 2004 and 2018, who were White or identified as Asian Indian/Pakistani, Chinese, Filipino, Hawaiian, Hmong, Japanese, Kampuchean, Korean, Laotian, Other Pacific Islander, Thai, or Vietnamese descent. Adjusted odds ratios and 95% confidence intervals of receiving palliative care were measured when comparing White vs. AA&NHPI patients as one cohort and White vs. disaggregated AA&NHPI patients, adjusting for clinical, socioeconomic, and demographic covariates.

RESULTS

Among 775,289 individuals diagnosed with cancer (median age: 68 years), no significant differences in palliative care receipt were observed between White patients and aggregated AA&NHPI patients among patients with prostate, breast, or lung cancer. However, disaggregated analyses revealed reduced palliative care receipt for breast cancer patients of Asian Indian/Pakistani descent (AOR 0.75, 95% CI, 0.60-0.94, P = 0.011) and for lung cancer patients of Chinese, Vietnamese, Thai, and Asian Indian/Pakistani descent compared to White patients (Chinese AOR 0.88, [0.81-0.94], P = 0.001; Vietnamese AOR 0.89, [0.80 to 0.99], P = 0.032; Thai AOR 0.64, [0.44-0.92], P = 0.016; Asian Indian/Pakistani AOR 0.83, [0.74-0.93], P = 0.001). Palliative care was greater for patients of Japanese and Hawaiian descent with prostate cancer (Japanese AOR 1.92, [1.32-2.75], P = 0.001; Hawaiian AOR 2.09, [1.20-3.66], P = 0.009), breast cancer (Japanese AOR 1.72, [1.21-2.43], P = 0.001; Hawaiian AOR 1.70, [1.08-2.67], P = 0.021), and lung cancer (Japanese AOR 1.92, [1.70-2.17], P < 0.001; Hawaiian AOR 2.95, [2.5-3.5], P < 0.001), as well as patients of Other Pacific Islander descent with lung cancer (AOR 1.62, [1.34-1.96], P < 0.001).

CONCLUSIONS AND RELEVANCE

Our findings demonstrate disparities in receipt of palliative care upon disaggregation of diverse AA&NHPI groups, the need for disaggregated research and targeted interventions that address the unique cultural, socioeconomic, and healthcare system barriers to palliative care receipt.

Treatment and Staging Intensification Strategies Associated with Radical Prostatectomy for High-Risk Prostate Cancer: Efficacy Evaluation and Exploration of Novel Approaches

The management of high-risk prostate cancer (PCa) presents a significant clinical challenge, often necessitating treatment intensification due to the potential presence of micrometastases. While radical prostatectomy (RP) constitutes one of the primary treatment modalities, the integration of neoadjuvant and adjuvant therapies suggests a paradigm shift towards more aggressive treatment strategies, also guided by new imaging modalities like positron emission tomography using prostate-specific membrane antigen (PSMA-PET). Despite the benefits, treatment intensification raises concerns regarding increased side effects. This review synthesizes the latest evidence on perioperative treatment intensification and de-escalation for high-risk localized and locally advanced PCa patients eligible for surgery. Through a non-systematic literature review conducted via PubMed, Scopus, Web of Science, and ClinicalTrials.gov, we explored various dimensions of perioperative treatments, including neoadjuvant systemic therapies, adjuvant therapies, and the role of novel diagnostic technologies. Emerging evidence provides more support for neoadjuvant systemic therapies. Preliminary results from studies suggest the potential for treatments traditionally reserved for metastatic PCa to show apparent benefit in a non-metastatic setting. The role of adjuvant treatments remains debated, particularly the use of androgen deprivation therapy (ADT) and adjuvant radiotherapy in patients at higher risk of biochemical recurrence. The potential role of radio-guided PSMA lymph node dissection emerges as a cutting-edge approach, offering a targeted method for eradicating disease with greater precision. Innovations such as artificial intelligence and machine learning are potential game-changers, offering new avenues for personalized treatment and improved prognostication. The intensification of surgical treatment in high-risk PCa patients is a dynamic and evolving field, underscored by the integration of traditional and novel therapeutic approaches. As evidence continues to emerge, these strategies will refine patient selection, enhance treatment efficacy, and mitigate the risk of progression, although with an attentive consideration of the associated side effects.

Metastatic Castration-Resistant Prostate Cancer: Advances in Treatment and Symptom Management

OPINION STATEMENT

The management of metastatic castrate-resistant prostate cancer (mCRPC) has evolved in the past decade due to substantial advances in understanding the genomic landscape and biology underpinning this form of prostate cancer. The implementation of various therapeutic agents has improved overall survival but despite the promising advances in therapeutic options, mCRPC remains incurable. The focus of treatment should be not only to improve survival but also to preserve the patient's quality of life (QoL) and ameliorate cancer-related symptoms such as pain. The choice and sequence of therapy for mCRPC patients are complex and influenced by various factors, such as side effects, disease burden, treatment history, comorbidities, patient preference and, more recently, the presence of actionable genomic alterations or biomarkers. Docetaxel is the first-line treatment for chemo-naïve patients with good performance status and those who have yet to progress on docetaxel in the castration-sensitive setting. Novel androgen agents (NHAs), such as abiraterone and enzalutamide, are effective treatment options that are utilized as second-line options. These medications can be considered upfront in frail patients or patients who are NHA naïve. Current guidelines recommend genetic testing in mCRPC for mutations in DNA repair deficiency genes to inform treatment decisions, as for example in breast cancer gene mutation testing. Other potential biomarkers being investigated include phosphatase and tensin homologues and homologous recombination repair genes. Despite a growing number of studies incorporating biomarkers in their trial designs, to date, only olaparib in the PROFOUND study and lutetium-177 in the VISION trial have improved survival. This is an unmet need, and future trials should focus on biomarker-guided treatment strategies. The advent of novel noncytotoxic agents has enhanced targeted drug delivery and improved treatment responses with favourable toxicity profiling. Trials should continue to incorporate and report health-related QoL scores and functional assessments into their trial designs.

Synthesis of 64Cu-, 55Co-, and 68Ga-Labeled Radiopharmaceuticals Targeting Neurotensin Receptor-1 for Theranostics: Adjusting In Vivo Distribution Using Multiamine Macrocycles

The development of theranostic radiotracers relies on their binding to specific molecular markers of a particular disease and the use of corresponding radiopharmaceutical pairs thereafter. This study reports the use of multiamine macrocyclic moieties (MAs), as linkers or chelators, in tracers targeting the neurotensin receptor-1 (NTSR-1). The goal is to achieve elevated tumor uptake, minimal background interference, and prolonged tumor retention in NTSR-1-positive tumors. Methods: We synthesized a series of neurotensin antagonists bearing MA linkers and metal chelators. The MA unit is hypothesized to establish a strong interaction with the cell membrane, and the addition of a second chelator may enhance water solubility, consequently reducing liver uptake. Small-animal PET/CT imaging of [64Cu]Cu-DOTA-SR-3MA, [64Cu]Cu-NT-CB-NOTA, [68Ga]Ga-NT-CB-NOTA, [64Cu]Cu-NT-CB-DOTA, and [64Cu]Cu-NT-Sarcage was acquired at 1, 4, 24, and 48 h after injection using H1299 tumor models. [55Co]Co-NT-CB-NOTA was also tested in HT29 (high NTSR-1 expression) and Caco2 (low NTSR-1 expression) colorectal adenocarcinoma tumor models. Saturation binding assay and internalization of [55Co]Co-NT-CB-NOTA were used to test tracer specificity and internalization in HT29 cells. Results: In vivo PET imaging with [64Cu]Cu-NT-CB-NOTA, [68Ga]Ga-NT-CB-NOTA, and [55Co]Co-NT-CB-NOTA revealed high tumor uptake, high tumor-to-background contrast, and sustained tumor retention (≤48 h after injection) in NTSR-1-positive tumors. Tumor uptake of [64Cu]Cu-NT-CB-NOTA remained at 76.9% at 48 h after injection compared with uptake 1 h after injection in H1299 tumor models, and [55Co]Co-NT-CB-NOTA was retained at 60.2% at 24 h compared with uptake 1 h after injection in HT29 tumor models. [64Cu]Cu-NT-Sarcage also showed high tumor uptake with low background and high tumor retention 48 h after injection Conclusion: Tumor uptake and pharmacokinetic properties of NTSR-1-targeting radiopharmaceuticals were greatly improved when attached with different nitrogen-containing macrocyclic moieties. The study results suggest that NT-CB-NOTA labeled with either 64Cu/67Cu, 55Co/58mCo, or 68Ga (effect of 177Lu in tumor to be determined in future studies) and NT-Sarcage labeled with 64Cu/67Cu or 55Co/58mCo may be excellent diagnostic and therapeutic radiopharmaceuticals targeting NTSR-1-positive cancers. Also, the introduction of MA units to other ligands is warranted in future studies to test the generality of this approach.

Genomics in active surveillance and post-prostatectomy patients: A review of when and how to use effectively

PURPOSE OF REVIEW

Prostate cancer (PCa) represents a significant health burden globally, ranking as the most diagnosed cancer among men and a leading cause of cancer-related mortality. Conventional treatment methods such as radiation therapy or radical prostatectomy have significant side effects which often impact quality of life. As our understanding of the natural history and progression of PCa has evolved, so has the evolution of management options.

RECENT FINDINGS

Active surveillance (AS) has become an increasingly favored approach to the management of very low, low, and properly selected favorable intermediate risk PCa. AS permits ongoing observation and postpones intervention until definitive treatment is required. There are, however, challenges with selecting patients for AS, which further emphasizes the need for more precise tools to better risk stratify patients and choose candidates more accurately. Tissue-based biomarkers, such as ProMark, Prolaris, GPS (formerly Oncotype DX), and Decipher, are valuable because they improve the accuracy of patient selection for AS and offer important information on the prognosis and severity of disease. By enabling patients to be categorized according to their risk profiles, these biomarkers help physicians and patients make better informed treatment choices and lower the possibility of overtreatment. Even with their potential, further standardization and validation of these biomarkers is required to guarantee their broad clinical utility. Active surveillance has emerged as a preferred strategy for managing low-risk prostate cancer, and tissue-based biomarkers play a crucial role in refining patient selection and risk stratification. Standardization and validation of these biomarkers are essential to ensure their widespread clinical use and optimize patient outcomes.

Expert Consensus Recommendations on the Management of Treatment-emergent Adverse Events Among Men with Prostate Cancer Taking Poly-ADP Ribose Polymerase Inhibitor + Novel Hormonal Therapy Combination Therapy

BACKGROUND AND OBJECTIVE

Recent clinical trials have shown improvement in progression-free survival in men with metastatic prostate cancer (mPC) treated with combination poly-ADP ribose polymerase (PARP) inhibitors (PARPi) and novel hormonal therapy (NHT). Regulatory bodies in the USA, Canada, Europe, and Japan have recently approved this combination therapy for mPC. Common adverse events (AEs) include fatigue, nausea and vomiting, and anemia. Nuanced AE management guidance for these combinations is lacking. The panel objective was to develop expert consensus on AE management in patients with mPC treated with the combination PARPi + NHT.

METHODS

The RAND/University of California Los Angeles modified Delphi Panel method was used. AEs were defined using the Common Terminology Criteria for Adverse Events. Twelve experts (seven medical oncologists, one advanced practice registered nurse, three urologists, and one patient advocate) reviewed the relevant literature; independently rated initial AE management options for the agent suspected of causing the AE for 419 patient scenarios on a 1-9 scale; discussed areas of agreement (AoAs) and disagreement (AoDs) at a March 2023 meeting; and repeated these ratings following the meeting. Second-round ratings formed the basis of guidelines.

KEY FINDINGS AND LIMITATIONS

AoDs decreased from 41% to 21% between the first and second round ratings, with agreement on at least one management strategy for every AE. AoAs included the following: (1) continue therapy with symptomatic treatment for patients with mild AEs; (2) for moderate fatigue, recommend nonpharmacologic treatment, hold treatment temporarily, and restart at a reduced dose when symptoms resolve; (3) for severe nausea or any degree of vomiting where symptomatic treatment fails, hold treatment temporarily and restart at a reduced dose when symptoms resolve; and (4) for hemoglobin 7.1-8.0 g/dl and symptoms of anemia, hold treatment temporarily and restart at a reduced dose after red blood cell transfusion.

CONCLUSIONS AND CLINICAL IMPLICATIONS

This expert guidance can support management of AEs in patients with mPC receiving combination PARPi + NHT therapy.

PATIENT SUMMARY

A panel of experts developed guidelines for adverse event (AE) management in patients with metastatic prostate cancer treated with a combination of poly-ADP ribose polymerase inhibitors and novel hormonal therapy. For mild AEs, continuation of cancer therapy along with symptomatic treatment is recommended. For moderate or severe AEs, cancer therapy should be stopped temporarily and restarted at the same or a reduced dose when AE resolves.

Targeting PI3K/AKT/mTOR signaling to overcome drug resistance in cancer

This review comprehensively explores the challenge of drug resistance in cancer by focusing on the pivotal PI3K/AKT/mTOR pathway, elucidating its role in oncogenesis and resistance mechanisms across various cancer types. It meticulously examines the diverse mechanisms underlying resistance, including genetic mutations, feedback loops, and microenvironmental factors, while also discussing the associated resistance patterns. Evaluating current therapeutic strategies targeting this pathway, the article highlights the hurdles encountered in drug development and clinical trials. Innovative approaches to overcome resistance, such as combination therapies and precision medicine, are critically analyzed, alongside discussions on emerging therapies like immunotherapy and molecularly targeted agents. Overall, this comprehensive review not only sheds light on the complexities of resistance in cancer but also provides a roadmap for advancing cancer treatment.

Within-trial hospitalization resource utilization and budget impact analysis for darolutamide in metastatic hormone-sensitive prostate cancer using ARASENS

BACKGROUND

ARASENS was a randomized, double-blind, phase 3 trial comparing darolutamide + docetaxel + androgen deprivation therapy (ADT) with placebo + docetaxel + ADT in patients with metastatic hormone-sensitive prostate cancer (mHSPC).

OBJECTIVE

To use clinical trial data from ARASENS to understand whether the addition of darolutamide to docetaxel + ADT leads to increased hospitalizations and to estimate the budget impact on the US health care system.

METHODS

We used mixed-effects negative binomial regression to estimate hospitalization and intensive care unit (ICU) admission rates and length of hospital stay (LoHS) counts. Hospitalization rates were estimated per treatment arm for the period during and after administration of docetaxel. Based on these estimates, a budget impact analysis evaluated the hospitalization costs (including ICU admissions) and standalone ICU hospitalization costs for the totality of the US population over a 5-year time horizon. The analysis compared a scenario without darolutamide vs one with darolutamide included in the US payer formulary. Hospitalization estimates were varied in a one-way sensitivity analysis.

RESULTS

The first 4 months of treatment (when patients were receiving docetaxel) were associated with increased hospitalizations across both arms. The addition of darolutamide was associated with a numerical reduction in the rate of hospitalization (per year) due to any reason both during docetaxel treatment (1.01 visits per year [95% CI = 0.82-1.20] vs 1.18 visits per year [95% CI = 0.96-1.41]) and after docetaxel treatment (0.28 visits per year [95% CI = 0.23-0.34] vs 0.33 visits per year [95% CI = 0.27-0.40]). Darolutamide was associated with a marginally longer LoHS per hospitalization compared with placebo (+1.90 days per year) both during and after docetaxel treatment. ICU admissions were low in the ARASENS data; admission rates were assumed to be the same during and after docetaxel treatment. ICU admission rate estimates were equivalent across arms (0.02 visits per year [95% CI = 0.01-0.03]). The budget impact per treated member per month represents a cost-neutral option after Year 5 with a cumulative budget impact of -$9.71.

CONCLUSIONS

The addition of darolutamide to docetaxel + ADT was associated with a numerically lower rate of hospitalization but marginally longer LoHS compared with docetaxel + ADT alone. Darolutamide represents a cost-neutral alternative per treated member per month compared with docetaxel + ADT with regard to hospitalizations at the end of a 5-year time horizon.

NTRK3-Rearranged Prostatic Acinar Adenocarcinoma: Report of a Patient and Review of the Literature

Molecular investigations have led to increased therapeutic options for prostatic adenocarcinoma. A single case report of a PRPSAP1::NTRK3 gene fusion occurring in prostate cancer was previously reported. A review of the literature revealed that NTRK gene rearrangements are exceedingly rare molecular events in prostate cancer. NTRK gene fusions can be oncogenic drivers or develop as resistance mechanisms. The tumor-agnostic approvals of TRK inhibitors by the FDA provide additional rationale for molecular investigations of aggressive prostatic adenocarcinomas. This may prove to be an additional therapeutic option for patients with aggressive prostatic carcinomas refractory to initial therapy. We report a case of an aggressive castrate-resistant prostatic adenocarcinoma with a BMP6::NTRK3 gene fusion.

Cancer risk and male Infertility: Unravelling predictive biomarkers and prognostic indicators

In recent years, there has been a global increase in cases of male infertility. There are about 30 million cases of male infertility worldwide and male reproductive health is showing rapid decline in last few decades. It is now recognized as a potential risk factor for developing certain types of cancer, particularly genitourinary malignancies like testicular and prostate cancer. Male infertility is considered a potential indicator of overall health and an early biomarker for cancer. Cases of unexplained male factor infertility have high levels of oxidative stress and oxidative DNA damage and this induces both denovo germ line mutations and epimutations due to build up of 8-hydroxy 2 deoxygunaosine abase which is highly mutagenic and also induces hypomethylation and genomic instability. Consequently, there is growing evidence to explore the various factors contributing to an increased cancer risk. Currently, the available prognostic and predictive biomarkers associated with semen characteristics and cancer risk are limited but gaining significant attention in clinical research for the diagnosis and treatment of elevated cancer risk in the individual and in offspring. The male germ cell being transcriptionally and translationally inert has a highly truncated repair mechanism and has minimal antioxidants and thus most vulnerable to oxidative injury due to environmental factors and unhealthy lifestyle and social habits. Therefore, advancing our understanding requires a thorough evaluation of the pathophysiologic mechanisms at the DNA, RNA, protein, and metabolite levels to identify key biomarkers that may underlie the pathogenesis of male infertility and associated cancer. Advanced methodologies such as genomics, epigenetics, proteomics, transcriptomics, and metabolomics stand at the forefront of cutting-edge approaches for discovering novel biomarkers, spanning from infertility to associated cancer types. Henceforth, in this review, we aim to assess the role and potential of recently identified predictive and prognostic biomarkers, offering insights into the success of assisted reproductive technologies, causes of azoospermia and idiopathic infertility, the impact of integrated holistic approach and lifestyle modifications, and the monitoring of cancer susceptibility, initiation and progression. Comprehending these biomarkers is crucial for providing comprehensive counselling to infertile men and cancer patients, along with their families.

Considerations for using potential surrogate endpoints in cancer screening trials

The requirement of large-scale expensive cancer screening trials spanning decades creates considerable barriers to the development, commercialisation, and implementation of novel screening tests. One way to address these problems is to use surrogate endpoints for the ultimate endpoint of interest, cancer mortality, at an earlier timepoint. This Review aims to highlight the issues underlying the choice and use of surrogate endpoints for cancer screening trials, to propose criteria for when and how we might use such endpoints, and to suggest possible candidates. We present the current landscape and challenges, and discuss lessons and shortcomings from the therapeutic trial setting. It is hugely challenging to validate a surrogate endpoint, even with carefully designed clinical studies. Nevertheless, we consider whether there are candidates that might satisfy the requirements defined by research and regulatory bodies.

Combined Cabazitaxel and Carboplatin Treatment of Metastatic Castration Resistant Prostate Cancer Patients, With Innate or Acquired Resistance to Cabazitaxel Monotherapy

BACKGROUND

There is new interest in platinum-based treatment of patients with metastatic castration resistant prostate cancer (mCRPC), to which a subgroup responds. Although platinum sensitivity is suggested to be associated with aggressive disease features and distinct molecular profiles, identification of responders is a clinical challenge. In this study, we selected patients who displayed PSA progression during cabazitaxel monotherapy, for combined cabazitaxel and carboplatin treatment.

METHODS

In this retrospective study, mCRPC patients received carboplatin and cabazitaxel after biochemical progression following at least 2 cabazitaxel monotherapy cycles. We assessed PSA response, Time to PSA Progression (TTpsa) and Time to Radiographic Progression (TTrad). For a subset of patients, mutational analysis of BRCA-1, BRCA-2, ATM, PTEN, P53 and RB1 was performed.

RESULTS

Forty-five patients were included, after a median of 4 (3-6) cycles of cabazitaxel monotherapy. Patients received a median of 3 (2-5) cycles of combined cabazitaxel and carboplatin, on which 12 (26.6%) patients had a PSA decline ≥ 50% from baseline. TTpsa was 2 (1-5) months and TTrad 3 (2-6) months. Adverse events were predominantly grade 1-2. Of the 29 (64.4%) patients evaluable for molecular signature, 6 (13.3%) had BRCA1, BRCA2 or ATM mutations and 12 (26.7%) had a PTEN, P53 or RB1 mutations. The occurrence of these mutations was not associated with any clinical outcome measure.

CONCLUSIONS

In this study we showed that patients with PSA progression during cabazitaxel monotherapy could benefit from the addition of carboplatin to cabazitaxel, while prospective identification of these patients remains a clinical challenge.

Lonidamine Induced Selective Acidification and De-Energization of Prostate Cancer Xenografts: Enhanced Tumor Response to Radiation Therapy

Prostate cancer is a multi-focal disease that can be treated using surgery, radiation, androgen deprivation, and chemotherapy, depending on its presentation. Standard dose-escalated radiation therapy (RT) in the range of 70-80 Gray (GY) is a standard treatment option for prostate cancer. It could be used at different phases of the disease (e.g., as the only primary treatment when the cancer is confined to the prostate gland, combined with other therapies, or as an adjuvant treatment after surgery). Unfortunately, RT for prostate cancer is associated with gastro-intestinal and genitourinary toxicity. We have previously reported that the metabolic modulator lonidamine (LND) produces cancer sensitization through tumor acidification and de-energization in diverse neoplasms. We hypothesized that LND could allow lower RT doses by producing the same effect in prostate cancer, thus reducing the detrimental side effects associated with RT. Using the Seahorse XFe96 and YSI 2300 Stat Plus analyzers, we corroborated the expected LND-induced intracellular acidification and de-energization of isolated human prostate cancer cells using the PC3 cell line. These results were substantiated by non-invasive 31P magnetic resonance spectroscopy (MRS), studying PC3 prostate cancer xenografts treated with LND (100 mg/kg, i.p.). In addition, we found that LND significantly increased tumor lactate levels in the xenografts using 1H MRS non-invasively. Subsequently, LND was combined with radiation therapy in a growth delay experiment, where we found that 150 µM LND followed by 4 GY RT produced a significant growth delay in PC3 prostate cancer xenografts, compared to either control, LND, or RT alone. We conclude that the metabolic modulator LND radio-sensitizes experimental prostate cancer models, allowing the use of lower radiation doses and diminishing the potential side effects of RT. These results suggest the possible clinical translation of LND as a radio-sensitizer in patients with prostate cancer.

Post-therapeutic squamous cell transformation of a metastatic prostate adenocarcinoma with comparison of molecular profiles: a case report and review of the literature

Transformation of primary prostate adenocarcinoma to squamous cell carcinoma after initial treatment with chemotherapy and hormonal therapy is extremely rare and typically results in rapid treatment-refractory disease progression and death. Here, we present a case of a 64-year-old man who was initially diagnosed with metastatic prostate adenocarcinoma (positive PSA and NKX3.1 stains, total PSA 747.2 ng/ml) to the thoracic spine (T8) in 2019. The patient received androgen deprivation therapy and chemotherapy with good response (PSA 2.53 ng/ml). In 2022, the patient had a tumor resection from the left humerus with a consequent fracture. Pathology showed pure squamous carcinoma without any adenocarcinoma component (PSA and NKX3.1 stains negative and weak p504s stain, PSA 19.82 ng/ml). Given the patient's history of metastatic prostate adenocarcinoma and no history of any other malignancies, a diagnosis of squamous carcinoma transformed from prostate adenocarcinoma was rendered. The patient passed away in 2023. Molecular profiling identified the same TP53 mutation and two variants of uncertain significance in both specimens, suggesting the same primary. However, there was CCND3 amplification and absence of the TMPRSS2::ETV4 fusion in the 2022 specimen, which may be associated with squamous transformation and poor prognosis. A microarray might be beneficial to confirm loss of the TMPRSS2::ETV4 fusion. This case illustrates the rare occurrence of squamous transformation in prostate adenocarcinoma and the aggressive clinical course, and need for more therapy guidance and prognostic studies. It also highlights the importance of molecular profiling to provide insights into the pathogenesis of histologic transformation.

From modulation of cellular plasticity to potentiation of therapeutic resistance: new and emerging roles of MYB transcription factors in human malignancies

MYB transcription factors are encoded by a large family of highly conserved genes from plants to vertebrates. There are three members of the MYB gene family in human, namely, MYB, MYBL1, and MYBL2 that encode MYB/c-MYB, MYBL1/A-MYB, and MYBL2/B-MYB, respectively. MYB was the first member to be identified as a cellular homolog of the v-myb oncogene carried by the avian myeloblastosis virus (AMV) causing leukemia in chickens. Under the normal scenario, MYB is predominantly expressed in hematopoietic tissues, colonic crypts, and neural stem cells and plays a role in maintaining the undifferentiated state of the cells. Over the years, aberrant expression of MYB genes has been reported in several malignancies and recent years have witnessed tremendous progress in understanding of their roles in processes associated with cancer development. Here, we review various MYB alterations reported in cancer along with the roles of MYB family proteins in tumor cell plasticity, therapy resistance, and other hallmarks of cancer. We also discuss studies that provide mechanistic insights into the oncogenic functions of MYB transcription factors to identify potential therapeutic vulnerabilities.

Localized radiotherapy of solid tumors using radiopharmaceutical loaded implantable system: insights from a mathematical model

Introduction

Computational models yield valuable insights into biological interactions not fully elucidated by experimental approaches. This study investigates an innovative spatiotemporal model for simulating the controlled release and dispersion of radiopharmaceutical therapy (RPT) using 177Lu-PSMA, a prostate-specific membrane antigen (PSMA) targeted radiopharmaceutical, within solid tumors via a dual-release implantable delivery system. Local delivery of anticancer agents presents a strategic approach to mitigate adverse effects while optimizing therapeutic outcomes.

Methods

This study evaluates various factors impacting RPT efficacy, including hypoxia region extension, binding affinity, and initial drug dosage, employing a novel 3-dimensional computational model. Analysis gauges the influence of these factors on radiopharmaceutical agent concentration within the tumor microenvironment. Furthermore, spatial and temporal radiopharmaceutical distribution within both the tumor and surrounding tissue is explored.

Results

Analysis indicates a significantly higher total concentration area under the curve within the tumor region compared to surrounding normal tissue. Moreover, drug distribution exhibits notably superior efficacy compared to the radiation source. Additionally, low microvascular density in extended hypoxia regions enhances drug availability, facilitating improved binding to PSMA receptors and enhancing therapeutic effectiveness. Reductions in the dissociation constant (KD) lead to heightened binding affinity and increased internalized drug concentration. Evaluation of initial radioactivities (7.1×107, 7.1×108, and 7.1×109 [Bq]) indicates that an activity of 7.1×108 [Bq] offers a favorable balance between tumor cell elimination and minimal impact on normal tissues.

Discussion

These findings underscore the potential of localized radiopharmaceutical delivery strategies and emphasize the crucial role of released drugs relative to the radiation source (implant) in effective tumor treatment. Decreasing the proximity of the drug to the microvascular network and enhancing its distribution within the tumor promote a more effective therapeutic outcome. The study furnishes valuable insights for future experimental investigations and clinical trials, aiming to refine medication protocols and minimize reliance on in vivo testing.

ROS-responsive polyprodrug micelles carrying suicide genes in combination with chemotherapy and gene therapy for prostate cancer treatment

Prostate cancer is the most common malignant tumor in the male reproductive system, and its incidence increases with age. Chemotherapy is one of the main strategies for treating prostate cancer, but it often comes with unavoidable side effects. Nanocarriers can improve drug utilization and targeting, and cationic carriers can also carry nucleic acids for gene therapy. In this study, we prepared a cationic micelle constructed from a polyprodrug that can deliver both chemotherapeutic drugs and nucleic acids simultaneously. The typical chemotherapeutic drug hydroxycamptothecin (HCPT) was linked by reactive oxygen species (ROS)-responsive coupling agents and forms amphiphilic block polymers with low molecular weight polyethyleneimine (PEI). The resulting cationic micelles can be triggered by high levels of ROS in tumor cells and collapse to release HCPT and suicide genes to kill tumor cells. At the same time, it reduces the killing of normal cells. In prostate cancer cells, it has been confirmed that the co-delivery carriers combined with chemotherapy and a suicide gene prodrug system have shown an ideal therapeutic effect on prostate cancer.

Overcoming Chemotherapy Resistance in Metastatic Cancer: A Comprehensive Review

The management of metastatic cancer is complicated by chemotherapy resistance. This manuscript provides a comprehensive academic review of strategies to overcome chemotherapy resistance in metastatic cancer. The manuscript presents background information on chemotherapy resistance in metastatic cancer cells, highlighting its clinical significance and the current challenges associated with using chemotherapy to treat metastatic cancer. The manuscript delves into the molecular mechanisms underlying chemotherapy resistance in subsequent sections. It discusses the genetic alterations, mutations, and epigenetic modifications that contribute to the development of resistance. Additionally, the role of altered drug metabolism and efflux mechanisms, as well as the activation of survival pathways and evasion of cell death, are explored in detail. The strategies to overcome chemotherapy resistance are thoroughly examined, covering various approaches that have shown promise. These include combination therapy approaches, targeted therapies, immunotherapeutic strategies, and the repurposing of existing drugs. Each strategy is discussed in terms of its rationale and potential effectiveness. Strategies for early detection and monitoring of chemotherapy drug resistance, rational drug design vis-a-vis personalized medicine approaches, the role of predictive biomarkers in guiding treatment decisions, and the importance of lifestyle modifications and supportive therapies in improving treatment outcomes are discussed. Lastly, the manuscript outlines the clinical implications of the discussed strategies. It provides insights into ongoing clinical trials and emerging therapies that address chemotherapy resistance in metastatic cancer cells. The manuscript also explores the challenges and opportunities in translating laboratory findings into clinical practice and identifies potential future directions and novel therapeutic avenues. This comprehensive review provides a detailed analysis of strategies to overcome chemotherapy resistance in metastatic cancer. It emphasizes the importance of understanding the molecular mechanisms underlying resistance and presents a range of approaches for addressing this critical issue in treating metastatic cancer.

Therapeutic Potential of Bipolar Androgen Therapy for Castration-Resistant Prostate Cancer: In Vitro and In Vivo Studies

Androgen deprivation therapy (ADT) is a primary treatment for advanced prostate cancer (PCa), but resistance often leads to castration-resistant PCa (CRPC). CRPC remains androgen receptor (AR)-dependent, and AR overexpression causes vulnerability to high doses of androgen in CRPC. Bipolar androgen therapy (BAT) refers to the periodic administration of testosterone, resulting in oscillation between supraphysiologic and near-castrate serum testosterone levels. In this study, we evaluated the efficacy of BAT against CRPC in a preclinical setting. To emulate CRPC characteristics, PCa cell lines (LNCaP, VCaP, and 22Rv1) were cultured in phenol red-free RPMI-1640 medium supplemented with 10% dextran-coated charcoal treated FBS (A- cell line). Cell viability, AR, and AR-V7 expression were evaluated using the Cell Counting Kit-8 and Western blotting. In vivo studies involved 12 castrated NOG mice injected with LNCaP/A- cells, treated with testosterone pellets or controls in 2-week cycles. Tumor sizes were measured post a 6-week treatment cycle. Bicalutamide inhibited PCa cell viability but not in the adapted cell lines. Supraphysiologic androgen levels suppressed AR-expressing PCa cell growth in vitro. In vivo, high AR-expressing LNCaP cells proliferated under castrate conditions, while BAT-treated xenografts exhibited significant growth inhibition with low Ki-67 and mitotic indexes and a high cell death index. This study provides preliminary evidence that BAT is effective for the treatment of CRPC through rapid cycling between supraphysiologic and near-castrate serum testosterone levels, inducing an anti-tumor effect.

PSMA Radioligand Therapy in Prostate Cancer: Where Are We and Where Are We Heading?

ABSTRACT

Diagnosis and treatment of prostate cancer are complex and very challenging, being a major health care burden. The efficacy of radioligand therapy with prostate-specific membrane antigen agents has been proven beneficial in certain clinical indications. In this review, we describe management of prostate cancer patients according to current guidelines, especially focusing on the available clinical evidence for prostate-specific membrane antigen radioligand therapy.

A Unique Case of Prostate Carcinoma Presenting as Retroperitoneal Lymphadenopathy With Normal Levels of Prostate-Specific Antigen and a Prostate of Normal Size: A Case Report

Despite the significant advancements in prostate-specific antigen (PSA) screening and the diverse array of available treatments, prostate cancer (PCa) still significantly contributes to cancer-related illness. The most prevalent sites for metastases are bones, distant lymph nodes, and abdominal organs. Nevertheless, metastasis to the renal and retroperitoneal regions originating from prostate cancer constitutes an exceptionally uncommon clinical occurrence. Metastatic PCa commonly presents with elevated serum PSA levels, a hallmark of its diagnostic profile. However, there are instances where patients exhibit atypical metastatic patterns or maintain normal PSA levels. In the case under consideration, the patient exhibited a periureteral tumor with an indeterminate primary origin, subsequently confirmed to be metastatic prostate cancer. This case underscores the importance of recognizing the varied and sometimes elusive presentations of metastatic PCa. Despite its rarity, the occurrence of renal and retroperitoneal metastasis emphasizes the need for vigilance and a comprehensive understanding of the diverse manifestations of advanced PCa for timely and accurate diagnosis, which is paramount in optimizing patient care and outcomes.

Diplopia and Ptosis: An Unusual Case of Prostate Cancer Metastasis to the Sphenoid Bone Treated With Palliative Radiotherapy

We report a case of a 72-year-old male who presented to the hospital with a chief complaint of diplopia in the setting of a recent onset of urinary incontinence and right-sided back pain. He was subsequently diagnosed with prostate cancer, notably metastasizing to the right sphenoid bone, causing impingement of the oculomotor nerve. Our case is unique in that the patient's initial presentation of prostate cancer was oculomotor nerve palsy with subsequent histologic analysis of the primary tumor showing both small cell neuroendocrine carcinoma along with adenocarcinoma. Also, the initial routine stroke protocol MRI and computed tomography angiography (CTA) missed the lesion, while gadolinium-enhanced targeted MRI revealed lesions in both the spine and the orbit. This case emphasizes the need for enhanced contrast as well as focused imaging in patients presenting with diplopia with a negative initial workup for stroke. Ptosis can be a sign of metastasis from other cancers and it is important to have a broad differential including metastatic disease in patients' presenting with similar symptoms and negative initial workup who may otherwise be at risk of cancer.

Activation of Dendritic Cells Isolated from the Blood of Patients with Prostate Cancer by Ex Vivo Fluid Shear Stress Stimulation

Prostate cancer is one of the most common cancers among men in the United States and a leading cause of cancer-related death in men. Treatment options for patients with advanced prostate cancer include hormone therapies, chemotherapies, radioligand therapies, and immunotherapies. Provenge (sipuleucel-T) is an autologous cancer-vaccine-based immunotherapy approved for men with asymptomatic or minimally symptomatic metastatic castration-resistant prostate cancer (mCRPC). Administration of sipuleucel-T involves leukapheresis of patient blood to isolate antigen-presenting cells (APCs), including dendritic cells (DCs), and subsequent incubation of isolated APCs with both an antigen, prostatic acid phosphatase (PAP), and granulocyte macrophage-colony stimulating factor (GM-CSF) before their infusion back into the patient. Although sipuleucel-T has been shown to improve overall survival, other meaningful outcomes, such as prostate-specific antigen (PSA) levels and radiographic response, are inconsistent. This lack of robust response may be due to limited ex vivo activation of DCs using current protocols. Earlier studies have shown that many cell types can be activated ex vivo by external forces such as fluid shear stress (FSS). We hypothesize that novel fluid shear stress technologies and methods can be used to improve ex vivo efficacy of prostate cancer DC activation in prostate cancer. Herein, we report a new protocol for activating DCs from patients with prostate cancer using ex vivo fluid shear stress. Ultimately, the goal of these studies is to improve DC activation to expand the efficacy of therapies such as sipuleucel-T. © 2023 The Authors. Current Protocols published by Wiley Periodicals LLC. Basic Protocol 1: Sample collection and DC isolation Basic Protocol 2: Determination and application of fluid shear stress Basic Protocol 3: Flow cytometry analysis of DCs after FSS stimulation.

Therapeutic, diagnostic and prognostic values of TRIM proteins in prostate cancer

Prostate cancer is the second most prevalent cancer in men worldwide. The TRIM (tripartite motif) family of proteins is involved in the regulation of various cellular processes, including antiviral immunity, apoptosis, and cancer progression. In recent years, several TRIM proteins have been found to play important roles in prostate cancer initiation and progression. TRIM proteins have indicated oncogenic activity in prostate cancer by enhancing androgen or estrogen receptor signaling and promoting cancer cell growth. Inhibition of TRIM proteins has been raised as a potential therapeutic strategy for the treatment of prostate cancer. Overall, these studies suggest that TRIM family proteins exert tumor-promoting effects in prostate cancer, and targeting these proteins can provide a promising therapeutic strategy for prostate cancer treatment. On the other hand, some TRIM proteins can be differentially expressed in prostate cancer cells compared to normal cells, thus providing novel diagnostic/prognostic biomarkers for prostate cancer.

Current role of PSMA-PET imaging in the clinical management of prostate cancer

Despite the developments of the last few years, metastatic castration-resistant prostate cancer (PC) remains a deadly disease. Until recently, almost all guidelines recommended magnetic resonance imaging (MRI) or computed tomography (CT) for the initial staging and local/systematic recurrence. Positron emission tomography/computed tomography (PET/CT) with prostate-specific membrane antigen (PSMA) at the present stage, emerged as a promising diagnostic imaging tool for PC. PSMA PET/CT alone or in combination with multiparametric magnetic resonance imaging (mpMRI) can improve the detection of clinically significant PC, especially for Prostate Imaging Reporting & Data System (PI-RADS) = 3 lesions. In addition, PSMA PET/CT is more accurate than CT and bone scan for intermediate to high-risk disease at the initial staging. Contrariwise, a negative PET is not useful for surgeons to avoid a pelvic nodal dissection. PET-PSMA imaging is appropriate for prostate-specific antigen (PSA) persistence or PSA rise from undetectable level after radical prostatectomy or for PSA rise above nadir after definitive radiotherapy. Also, it is recommended for patients fit for curative salvage treatment. It should be noted that in patients, candidates for radionuclide therapy with Lutetium-177 (117Lu), a PSMA strong expression from PET/CT at baseline is considered necessary. This review summarizes the evolution of PSMA PET/CT and its current role in the management of PC.

Alpha Satellite DNA in Targeted Drug Therapy for Prostate Cancer

Prostate cancer is the most common solid cancer in men and, despite the development of many new therapies, metastatic castration-resistant prostate cancer still remains a deadly disease. Therefore, novel concepts for the treatment of metastatic prostate cancer are needed. In our opinion, the role of the non-coding part of the genome, satellite DNA in particular, has been underestimated in relation to diseases such as cancer. Here, we hypothesise that this part of the genome should be considered as a potential target for the development of new drugs. Specifically, we propose a novel concept directed at the possible treatment of metastatic prostate cancer that is mostly based on epigenetics. Namely, metastatic prostate cancer is characterized by the strongly induced transcription of alpha satellite DNA located in pericentromeric heterochromatin and, according to our hypothesis, the stable controlled transcription of satellite DNA might be important in terms of the control of disease development. This can be primarily achieved through the epigenetic regulation of pericentromeric heterochromatin by using specific enzymes as well as their activators/inhibitors that could act as potential anti-prostate cancer drugs. We believe that our concept is innovative and should be considered in the potential treatment of prostate cancer in combination with other more conventional therapies.

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.

The Effect of Natural Substances Contained in Bee Products on Prostate Cancer in In Vitro Studies

Prostate cancer is a common cancer in men in older age groups. The WHO forecasts an increase in the incidence of prostate cancer in the coming years. Patients may not respond to treatment, and may not tolerate the side effects of chemotherapy. Compounds of natural origin have long been used in the prevention and treatment of cancer. Flavonoids obtained from natural products, e.g., propolis, are compounds with proven antibacterial and antiviral efficacy which modulate the immune response and may be useful as adjuvants in chemotherapy. The main aim of the present study was to evaluate the cytotoxic and pro-apoptotic properties of selected flavonoids on prostate cancer cells of the LNCaP line. The compounds used in this study were CAPE, curcumin (CUR), and quercetin (QUE). Mitochondrial and lysosome metabolism was assessed by the XTT-NR-SRB triple assay as well as by the fluorescent staining techniques. Staining for reactive oxygen species was performed as well. The experiment showed that each of the tested compounds has a cytotoxic effect on the LNCaP cell line. Different types of cell death were induced by the tested compounds. Apoptosis was induced by quercetin, while autophagy-specific changes were observed after using CAPE. Compounds obtained from other bee products have antiproliferative and cytotoxic activity against LNCaP prostate cancer cells.

Reliability and Efficiency of the CAPRI-3 Metastatic Prostate Cancer Registry Driven by Artificial Intelligence

BACKGROUND

Manual data collection is still the gold standard for disease-specific patient registries. However, CAPRI-3 uses text mining (an artificial intelligence (AI) technology) for patient identification and data collection. The aim of this study is to demonstrate the reliability and efficiency of this AI-driven approach.

METHODS

CAPRI-3 is an observational retrospective multicenter cohort registry on metastatic prostate cancer. We tested the patient-identification algorithm and automated data extraction through manual validation of the same patients in two pilots in 2019 and 2022.

RESULTS

Pilot one identified 2030 patients and pilot two 9464 patients. The negative predictive value of the algorithm was maximized to prevent false exclusions and reached 94.8%. The completeness and accuracy of the automated data extraction were 92.3% or higher, except for date fields and inaccessible data (images/pdf) (10-88.9%). Additional manual quality control took over 3 h less time per patient than the original fully manual CAPRI registry (105 vs. 300 min).

CONCLUSIONS

The CAPRI-3 patient-identification algorithm is a sound replacement for excluding ineligible candidates. The AI-driven data extraction is largely accurate and complete, but manual quality control is needed for less reliable and inaccessible data. Overall, the AI-driven approach of the CAPRI-3 registry is reliable and timesaving.

Targeting P21-Activated Kinase-1 for Metastatic Prostate Cancer

Metastatic prostate cancer (mPCa) has limited therapeutic options and a high mortality rate. The p21-activated kinase (PAK) family of proteins is important in cell survival, proliferation, and motility in physiology, and pathologies such as infectious, inflammatory, vascular, and neurological diseases as well as cancers. Group-I PAKs (PAK1, PAK2, and PAK3) are involved in the regulation of actin dynamics and thus are integral for cell morphology, adhesion to the extracellular matrix, and cell motility. They also play prominent roles in cell survival and proliferation. These properties make group-I PAKs a potentially important target for cancer therapy. In contrast to normal prostate and prostatic epithelial cells, group-I PAKs are highly expressed in mPCA and PCa tissue. Importantly, the expression of group-I PAKs is proportional to the Gleason score of the patients. While several compounds have been identified that target group-I PAKs and these are active in cells and mice, and while some inhibitors have entered human trials, as of yet, none have been FDA-approved. Probable reasons for this lack of translation include issues related to selectivity, specificity, stability, and efficacy resulting in side effects and/or lack of efficacy. In the current review, we describe the pathophysiology and current treatment guidelines of PCa, present group-I PAKs as a potential druggable target to treat mPCa patients, and discuss the various ATP-competitive and allosteric inhibitors of PAKs. We also discuss the development and testing of a nanotechnology-based therapeutic formulation of group-I PAK inhibitors and its significant potential advantages as a novel, selective, stable, and efficacious mPCa therapeutic over other PCa therapeutics in the pipeline.

Let’s Go 3D! New Generation of Models for Evaluating Drug Response and Resistance in Prostate Cancer

Prostate cancer (PC) is the third most frequently diagnosed cancer worldwide and the second most frequent in men. Several risk factors can contribute to the development of PC, and those include age, family history, and specific genetic mutations. So far, drug testing in PC, as well as in cancer research in general, has been performed on 2D cell cultures. This is mainly because of the vast benefits these models provide, including simplicity and cost effectiveness. However, it is now known that these models are exposed to much higher stiffness; lose physiological extracellular matrix on artificial plastic surfaces; and show changes in differentiation, polarization, and cell–cell communication. This leads to the loss of crucial cellular signaling pathways and changes in cell responses to stimuli when compared to in vivo conditions. Here, we emphasize the importance of a diverse collection of 3D PC models and their benefits over 2D models in drug discovery and screening from the studies done so far, outlining their benefits and limitations. We highlight the differences between the diverse types of 3D models, with the focus on tumor–stroma interactions, cell populations, and extracellular matrix composition, and we summarize various standard and novel therapies tested on 3D models of PC for the purpose of raising awareness of the possibilities for a personalized approach in PC therapy.