Progression in immunotherapy for advanced prostate cancer

Stemness regulation in prostate cancer: prostate cancer stem cells and targeted therapy

BACKGROUND

Increasing evidence indicates that cancer stem cells (CSCs) and cancer stem-like cells form a special subpopulation of cells that are ubiquitous in tumors. These cells exhibit similar characteristics to those of normal stem cells in tissues; moreover, they are capable of self-renewal and differentiation, as well as high tumorigenicity and drug resistance. In prostate cancer (PCa), it is difficult to kill these cells using androgen signaling inhibitors and chemotherapy drugs. Consequently, the residual prostate cancer stem cells (PCSCs) mediate tumor recurrence and progression.

OBJECTIVE

This review aims to provide a comprehensive and up-to-date overview of PCSCs, with a particular emphasis on potential therapeutic strategies targeting these cells.

METHODS

After searching in PubMed and Embase databases using 'prostate cancer' and 'cancer stem cells' as keywords, studies related were compiled and examined.

RESULTS

In this review, we detail the origin and characteristics of PCSCs, introduce the regulatory pathways closely related to CSC survival and stemness maintenance, and discuss the link between epithelial-mesenchymal transition, tumor microenvironment and tumor stemness. Furthermore, we introduce the currently available therapeutic strategies targeting CSCs, including signaling pathway inhibitors, anti-apoptotic protein inhibitors, microRNAs, nanomedicine, and immunotherapy. Lastly, we summarize the limitations of current CSC research and mention future research directions.

CONCLUSION

A deeper understanding of the regulatory network and molecular markers of PCSCs could facilitate the development of novel therapeutic strategies targeting these cells. Previous preclinical studies have demonstrated the potential of this treatment approach. In the future, this may offer alternative treatment options for PCa patients.

Application progress of nanomaterials in the treatment of prostate cancer

Prostate cancer is one of the most common malignant tumors in men, which seriously threatens the survival and quality of life of patients. At present, there are serious limitations in the treatment of prostate cancer, such as drug tolerance, drug resistance and easy recurrence. Sonodynamic therapy and chemodynamic therapy are two emerging tumor treatment methods, which activate specific drugs or sonosensitizers through sound waves or chemicals to produce reactive oxygen species and kill tumor cells. Nanomaterials are a kind of nanoscale materials with many excellent physical properties such as high targeting, drug release regulation and therapeutic monitoring. Sonodynamic therapy and chemodynamic therapy combined with the application of nanomaterials can improve the therapeutic effect of prostate cancer, reduce side effects and enhance tumor immune response. This article reviews the application progress of nanomaterials in the treatment of prostate cancer, especially the mechanism, advantages and challenges of nanomaterials in sonodynamic therapy and chemodynamic therapy, which provides new ideas and prospects for research in this field.

Innovations and Emerging Trends in Prostate Cancer Management: A Literature Review

Prostate cancer (PC) is considered the second most diagnosed cancer in men worldwide. It remains a leading cause of cancer-related death. Recently, many modalities have been discovered and used in the diagnosis and management of PC, with the incorporation of many treatment options such as hormonal therapy, chemotherapy, targeted therapies, immunotherapy, and precision medicine. Robotics and artificial intelligence (AI) have further modified the diagnosis and management of PCs, improving the diagnosis accuracy and disease progression. This comprehensive review offers an in-depth exploration of the historical modalities of treatments, an evaluation of current therapeutic techniques, a discussion of the use of robotic surgery and AI, and an examination of ongoing clinical trials and emerging procedures. Additionally, this review also covers the challenges. By inspecting these aspects, the review may provide valuable information regarding future research and clinical practice directions in PC treatment, contributing to a thorough understanding of the complex and emerging context of PC management.

Health Professionals' Perceptions about Prostate Cancer-A Focus Group Study

Prostate cancer (PCa) accounts for 20% of new cancer cases and 10.5% of cancer-associated mortality in Portugal. Associated risk factors include advanced age, family history, genetic alterations, and race/ethnicity. However, the role of lifestyle factors is often underestimated. To explore health professionals' perceptions of PCa risk factors, a qualitative study with three focus groups (FG), with a total of twenty-one general practitioners and urologists, was conducted via videoconference between February and April 2023. Seven themes emerged, including general perceptions of PCa; PCa risk factors; nutritional impact; the role of physical activity; alcohol consumption and smoking; sexual activity and sexually transmitted diseases roles in PCa; and screening, diagnosis, and treatment methods. Despite agreeing that healthy lifestyles could promote better PCa outcomes and quality of life, participants did not specify any lifestyle factors that could promote or prevent this disease, posing challenges to lifestyle changes, particularly among older adults. Non-invasive screening methods, such as biomarkers and alternative treatments, are crucial for future research. This study underscores the need for further investigation into the correlation of lifestyle factors with PCa and highlights the necessity of health professionals in encouraging their patients to adopt healthier lifestyles, while offering important insights into awareness, prevention, and alternative screening, diagnosis, and treatment methods, which could help reduce false positives and treatment side effects.

Decreased levels of PTCSC3 promote the deterioration of prostate cancer and affect the prognostic outcome of patients through sponge miR-182-5p

BACKGROUND

Prostate cancer, characterized by its insidious onset and short overall survival, and has seen a rise in incidence over recent decades. This study aims to investigate the expression and molecular mechanism of lncRNA PTCSC3 (PTCSC3) in prostate cancer in order to develop new prognostic and therapeutic biomarkers.

METHODS

The level of PTCSC3 in serum and cell samples of prostate cancer was quantitatively measured using RT-qPCR assays. The correlation between the variation in PTCSC3 levels and clinical indicators of patients was evaluated. The survival status of the prostate cancer patients included in the study was evaluated using Kaplan-Meier curve and multivariable Cox analysis. The impact of PTCSC3 overexpression on cell growth and activity was revealed by CCK-8 and Transwell assays. The targeting relationship between PTCSC3 and miR-182-5p was determined by bioinformatics prediction and luciferase activity.

RESULTS

PTCSC3 was found to be downregulated in prostate cancer, and its low levels were associated with short overall survival in patients. It influenced the progression of prostate cancer by targeting miR-182-5p. Increasing PTCSC3 levels suppressed the proliferation, migration and invasion levels of cells, and miR-182-5p mimic counteracted PTCSC3's effects on cells.

CONCLUSIONS

As a potential prognostic biological factor for prostate cancer, PTCSC3 may regulate the progression of prostate cancer by sponging miR-182-5p and affect the prognosis of patients.

Irradiated microparticles suppress prostate cancer by tumor microenvironment reprogramming and ferroptosis

Immunogenic cell death (ICD) plays a crucial role in triggering the antitumor immune response in the tumor microenvironment (TME). Recently, considerable attention has been dedicated to ferroptosis, a type of ICD that is induced by intracellular iron and has been demonstrated to change the immune desert status of the TME. However, among cancers that are characterized by an immune desert, such as prostate cancer, strategies for inducing high levels of ferroptosis remain limited. Radiated tumor cell-derived microparticles (RMPs) are radiotherapy mimetics that have been shown to activate the cGAS-STING pathway, induce tumor cell ferroptosis, and inhibit M2 macrophage polarization. RMPs can also act as carriers of agents with biocompatibility. In the present study, we designed a therapeutic system wherein the ferroptosis inducer RSL-3 was loaded into RMPs, which were tested in in vitro and in vivo prostate carcinoma models established using RM-1 cells. The apoptosis inducer CT20 peptide (CT20p) was also added to the RMPs to aggravate ferroptosis. Our results showed that RSL-3- and CT20p-loaded RMPs (RC@RMPs) led to ferroptosis and apoptosis of RM-1 cells. Moreover, CT20p had a synergistic effect on ferroptosis by promoting reactive oxygen species (ROS) production, lipid hydroperoxide production, and mitochondrial instability. RC@RMPs elevated dendritic cell (DC) expression of MHCII, CD80, and CD86 and facilitated M1 macrophage polarization. In a subcutaneously transplanted RM-1 tumor model in mice, RC@RMPs inhibited tumor growth and prolonged survival time via DC activation, macrophage reprogramming, enhancement of CD8+ T cell infiltration, and proinflammatory cytokine production in the tumor. Moreover, combination treatment with anti-PD-1 improved RM-1 tumor inhibition. This study provides a strategy for the synergistic enhancement of ferroptosis for prostate cancer immunotherapies.

CDK12 regulates angiogenesis of advanced prostate cancer by IGFBP3

Prostate cancer (PCa) is a prevalent malignancy among men, with a majority of patients presenting with distant metastases at the time of initial diagnosis. These patients are at a heightened risk of developing more aggressive castration‑resistant PCa following androgen deprivation therapy, which poses a greater challenge for treatment. Notably, the inhibition of tumor angiogenesis should not be considered an ineffective treatment strategy. The regulatory role of CDK12 in transcriptional and post‑transcriptional processes is essential for the proper functioning of various cellular processes. In the present study, the expression of CDK12 was first knocked down in cells using CRISPR or siRNA technology. Subsequently, RNA‑seq analysis, co‑immunoprecipitation, western blotting, reverse transcription‑quantitative polymerase chain reaction and the LinkedOmics database were employed to reveal that CDK12 inhibits insulin like growth factor binding protein 3 (IGFBP3). Western blot analysis also demonstrated that CDK12 promoted VEGFA expression by inhibiting IGFBP3, which involves the Akt signaling pathway. Then, CDK12 was found to promote PCa cell proliferation, cell migration and angiogenesis by inhibiting IGFBP3 through cell proliferation assays, cell migration assays and tube formation assays, respectively. Finally, animal experiments were performed for in vivo validation. It was concluded that CDK12 promoted PCa and its angiogenesis by inhibiting IGFBP3.

Synergistic Cytotoxicity of a Toxin Targeting the Epidermal Growth Factor Receptor and the Glycosylated Triterpenoid SO1861 in Prostate Cancer

Treatment of advanced prostate cancer lacks specificity and curative intent. Therefore, the need for new targeted therapeutic approaches is high. In the present study, we generated the new targeted toxin EGF-PE24mutΔREDLK binding to the epidermal growth factor receptor (EGFR) on the surface of prostate cancer cells. It consists of the human epidermal growth factor (EGF) as binding domain and a de-immunized variant of Pseudomonas Exotoxin A (PE), called PE24mutΔREDLK, as toxin domain. The toxin domain contains a deletion of the C-terminal KDEL-like motif REDLK to prevent its transport from sorting endosomes via the KDEL receptor mediated pathway into the cytosol, where it can inhibit cellular protein biosynthesis and induce apoptosis. Indeed, REDLK deletion resulted in a strong decrease in cytotoxicity of the targeted toxin in prostate cancer cells compared to the parental targeted toxin EGF-PE24mut. However, addition of the plant glycosylated triterpenoid SO1861, which is known to mediate the release of biomolecules from endolysosomal compartments into the cytosol, resulted in an up to almost 7,000-fold enhanced synergistic cytotoxicity. Moreover, combination of PE24mutΔREDLK with SO1861 led to a cytotoxicity that was even 16- to 300-fold enhanced compared to that of EGF-PE24mut. Endolysosomal entrapment of the non-toxic targeted toxin EGF-PE24mutΔREDLK followed by activation through enhanced endosomal escape therefore represents a new promising approach for the future treatment of advanced prostate cancer with high efficacy and diminished side effects.

Systemic Alterations of Cancer Cells and Their Boost by Polyploidization: Unicellular Attractor (UCA) Model

Using meta-analyses, we introduce a unicellular attractor (UCA) model integrating essential features of the ‘atavistic reversal’, ‘cancer attractor’, ‘somatic mutation’, ‘genome chaos’, and ‘tissue organization field’ theories. The ‘atavistic reversal’ theory is taken as a keystone. We propose a possible mechanism of this reversal, its refinement called ‘gradual atavism’, and evidence for the ‘serial atavism’ model. We showed the gradual core-to-periphery evolutionary growth of the human interactome resulting in the higher protein interaction density and global interactome centrality in the UC center. In addition, we revealed that UC genes are more actively expressed even in normal cells. The modeling of random walk along protein interaction trajectories demonstrated that random alterations in cellular networks, caused by genetic and epigenetic changes, can result in a further gradual activation of the UC center. These changes can be induced and accelerated by cellular stress that additionally activates UC genes (especially during cell proliferation), because the genes involved in cellular stress response and cell cycle are mostly of UC origin. The functional enrichment analysis showed that cancer cells demonstrate the hyperactivation of energetics and the suppression of multicellular genes involved in communication with the extracellular environment (especially immune surveillance). Collectively, these events can unleash selfish cell behavior aimed at survival at all means. All these changes are boosted by polyploidization. The UCA model may facilitate an understanding of oncogenesis and promote the development of therapeutic strategies.