Immune Therapy for Prostate Cancer

Redox State Modulatory Activity and Cytotoxicity of Olea europaea L. (Oleaceae) Leaves Extract Enriched in Polyphenols Using Macroporous Resin

The food products derived from Olea europaea are a fundamental part of the Mediterranean diet, and their health-promoting effects are well known. In this study, we analyzed the phytochemical characteristics, the redox state modulatory activity, and the cytotoxic effect of an olive leaf aqueous extract enriched by macroporous resin on different tumor and normal cell lines (LNCaP, PC3, HFF-1). HPLC-DAD analysis, the Folin-Ciocalteu and aluminum chloride methods confirmed the qualitatively and quantitatively high content of phenolic compounds (130.02 ± 2.3 mg GAE/g extract), and a DPPH assay (IC50 = 100.00 ± 1.8 μg/mL), the related antioxidant activity. The biological investigation showed a significant cytotoxic effect, highlighted by an MTT test and the evident cellular morphological changes, on two prostate cancer cell lines. Remarkably, the extract was practically non-toxic on HFF-1 at the concentrations (100, 150, 300 µg/mL) and exposure times tested. Hence, the results are selective for tumor cells. The underlying cytotoxicity was associated with the decrease in ROS production (55% PC3, 42% LNCaP) and the increase in RSH levels (>50% PC3) and an LDH release assay (50% PC3, 40% LNCaP, established necrosis as the main cell death mechanism.

Reprint of: morphologic spectrum of treatment-related changes in prostate tissue and prostate cancer: an updated review

A wide range of treatment options are available to patients with prostate cancer. Some treatments are standard (currently used) while some are emerging therapies. Androgen deprivation therapy is typically reserved for localized or metastatic prostate cancer not amenable to surgery. Radiation therapy may be offered to individuals for local therapy with curative intent in low- or intermediate-risk disease that may have a high probability of progression on active surveillance or where surgery is not suitable. Focal therapy/ablation treatment is an alternative approach for those who prefer to avoid radical prostatectomy for localized disease of low- or intermediate-risk or as salvage therapy after failed radiation therapy. Chemotherapy and immunotherapy remain under investigation and are currently used for androgen-independent disease or hormone-refractory prostate cancer; however, a better understanding of therapeutic efficacy is needed. Histopathologic changes observed in benign and malignant prostate tissue induced by hormonal therapies and radiation therapy are well described, whereas treatment-related effects secondary to novel therapies continue to be documented although their clinical significance is not absolutely clear. An informed and accurate evaluation of post-treatment prostate specimens requires pathologists with diagnostic acumen and knowledge relating to the histopathologic spectrum associated with each treatment option. In situations when clinical history is lacking, but morphologic features are suggestive of prior treatment, pathologists are encouraged to consult clinical colleagues regarding prior treatment history including details of when treatment was initiated and duration of therapy. This review aims to provide a concise update of current and emerging therapies for prostate cancer, histologic alterations and recommendations on Gleason grading.

Spontaneous Remission of Metastatic Castration-Resistant Prostate Cancer: Coley's Toxin Revisited?

Metastatic castration-resistant prostate cancer (mCRPC) is an incurable disease associated with poor survival outcomes. Immunotherapy was first pioneered by William Coley in the early 20th century with the injection of live and heat-killed bacteria. Despite the recent emergence of cancer immunotherapy, mCRPC remains an elusive immune target. Spontaneous remission of mCRPC following microbial infection has not been described in the literature to date. We present evidence of spontaneous biochemical and radiologic regression in a patient with mCRPC following multiple episodes of sepsis.

Role of prostate cancer stem-like cells in the development of antiandrogen resistance

Androgen deprivation therapy (ADT) is the standard of care treatment for advance stage prostate cancer. Treatment with ADT develops resistance in multiple ways leading to the development of castration-resistant prostate cancer (CRPC). Present research establishes that prostate cancer stem-like cells (CSCs) play a central role in the development of treatment resistance followed by disease progression. Prostate CSCs are capable of self-renewal, differentiation, and regenerating tumor heterogeneity. The stemness properties in prostate CSCs arise due to various factors such as androgen receptor mutation and variants, epigenetic and genetic modifications leading to alteration in the tumor microenvironment, changes in ATP-binding cassette (ABC) transporters, and adaptations in molecular signaling pathways. ADT reprograms prostate tumor cellular machinery leading to the expression of various stem cell markers such as Aldehyde Dehydrogenase 1 Family Member A1 (ALDH1A1), Prominin 1 (PROM1/CD133), Indian blood group (CD44), SRY-Box Transcription Factor 2 (Sox2), POU Class 5 Homeobox 1(POU5F1/Oct4), Nanog and ABC transporters. These markers indicate enhanced self-renewal and stemness stimulating CRPC evolution, metastatic colonization, and resistance to antiandrogens. In this review, we discuss the role of ADT in prostate CSCs differentiation and acquisition of CRPC, their isolation, identification and characterization, as well as the factors and pathways contributing to CSCs expansion and therapeutic opportunities.

Characterization of Immune-Based Molecular Subtypes and Prognostic Model in Prostate Adenocarcinoma

Prostate adenocarcinoma (PRAD), also named prostate cancer, the most common visceral malignancy, is diagnosed in male individuals. Herein, in order to obtain immune-based subtypes, we performed an integrative analysis to characterize molecular subtypes based on immune-related genes, and further discuss the potential features and differences between identified subtypes. Simultaneously, we also construct an immune-based risk model to assess cancer prognosis. Our findings showed that the two subtypes, C1 and C2, could be characterized, and the two subtypes showed different characteristics that could clearly describe the heterogeneity of immune microenvironments. The C2 subtype presented a better survival rate than that in the C1 subtype. Further, we constructed an immune-based prognostic model based on four screened abnormally expressed genes, and they were selected as predictors of the robust prognostic model (AUC = 0.968). Our studies provide reference for characterization of molecular subtypes and immunotherapeutic agents against prostate cancer, and the developed robust and useful immune-based prognostic model can contribute to cancer prognosis and provide reference for the individualized treatment plan and health resource utilization. These findings further promote the development and application of precision medicine in prostate cancer.

Morphologic spectrum of treatment-related changes in prostate tissue and prostate cancer: An Updated Review

A wide range of treatment options is available to patients with prostate cancer. Some treatments are standard (currently used) while some are emerging therapies. Androgen deprivation therapy is typically reserved for localized or metastatic prostate cancer not amenable to surgery. Radiation therapy may be offered to individuals for local therapy with curative intent in low- or intermediate-risk disease that may have a high probability of progression on active surveillance or where surgery is not suitable. Focal therapy/ablation treatment is an alternative approach for those who prefer to avoid radical prostatectomy for localized disease of low- or intermediate-risk or as salvage therapy following failed radiation therapy. Chemotherapy and immunotherapy remain under investigation and are currently used for androgen-independent disease or hormone-refractory prostate cancer; however a better understand therapeutic efficacy is needed. Histopathologic changes observed in benign and malignant prostate tissue induced by hormonal therapies and radiation therapy is well described, while treatment-related effects secondary to novel therapies continue to be documented although their clinical significance is not absolutely clear. An informed and accurate evaluation of post-treatment prostate specimens requires pathologists with diagnostic acumen and knowledge relating to the histopathologic spectrum associated with each treatment option. In situations when clinical history is lacking, but morphologic features are suggestive of prior treatment, pathologists are encouraged to consult clinical colleagues regarding prior treatment history including details of when treatment was initiated and duration of therapy. This review aims to provide a concise update of current and emerging therapies for prostate cancer, histologic alterations and recommendations on Gleason grading.

Clinical proteomics for prostate cancer: understanding prostate cancer pathology and protein biomarkers for improved disease management

Following the introduction of routine Prostate Specific Antigen (PSA) screening in the early 1990′s, Prostate Cancer (PCa) is often detected at an early stage. There are also a growing number of treatment options available and so the associated mortality rate is generally low. However, PCa is an extremely complex and heterogenous disease and many patients suffer disease recurrence following initial therapy. Disease recurrence commonly results in metastasis and metastatic PCa has an average survival rate of just 3–5 years. A significant problem in the clinical management of PCa is being able to differentiate between patients who will respond to standard therapies and those who may benefit from more aggressive intervention at an earlier stage. It is also acknowledged that for many men the disease is not life threatenting. Hence, there is a growing desire to identify patients who can be spared the significant side effects associated with PCa treatment until such time (if ever) their disease progresses to the point where treatment is required. To these important clinical needs, current biomarkers and clinical methods for patient stratification and personlised treatment are insufficient. This review provides a comprehensive overview of the complexities of PCa pathology and disease management. In this context it is possible to review current biomarkers and proteomic technologies that will support development of biomarker-driven decision tools to meet current important clinical needs. With such an in-depth understanding of disease pathology, the development of novel clinical biomarkers can proceed in an efficient and effective manner, such that they have a better chance of improving patient outcomes.

Prostate cancer, new treatment advances - immunotherapy

Prostate cancer (PCa) is the fourth most common cancer in the world and treatment is currently based on surgical removal and/or radiotherapy and/or hormone therapy. In the last few years' immunotherapy has become an important cancer treatment option. While the principles of immunotherapy evolved, only sipuleucel-T was approved by the Food and Drug Administration (FDA) which lead to further studies with other agents, starting a new era in immuno-oncology. A number of vaccines are under clinical investigation as well as checkpoint inhibitors. Despite the current enthusiasm, it is unlikely that any of the approaches alone can dramatically change PCa outcomes, but strategies combination is more promising and provide a reason for optimism. The goal of immunotherapy in PCa does not have to be the complete eradication of advanced disease, but rather the return to an immunologic equilibrium with an indolent disease state. With such concerted efforts, the future of immunotherapy in PCa looks brighter than ever, with many clinical trial results being published soon.

New Prostate Cancer Targets for Diagnosis, Imaging, and Therapy: Focus on Prostate-Specific Membrane Antigen

The rising incidence rate of the cancer in the prostate gland has increased the demand for improved diagnostic, imaging, and therapeutic approaches. Prostate-specific membrane antigen (PSMA), with folate hydrolase and carboxypeptidase and, internalization activities, is highly expressed in the epithelial cells of the prostate gland and is strongly upregulated in prostatic adenocarcinoma, with elevated expression correlating with, metastasis, progression, and androgen independence. Recently, PSMA has been an active target of investigation by several approaches, including the successful utilization of small molecule inhibitors, RNA aptamer conjugates, PSMA-based immunotherapy, and PSMA-targeted prodrug therapy. Future investigations of PSMA in prostate cancer (PCa) should focus in particular on its intracellular activities and functions. The objective of this contribution is to review the current role of PSMA as a marker for PCa diagnosis, imaging, and therapy.

Expression analysis of cancer-testis genes in prostate cancer reveals candidates for immunotherapy

Prostate cancer is a prevalent disorder among men with a heterogeneous etiological background. Several molecular events and signaling perturbations have been found in this disorder. Among genes whose expressions have been altered during the prostate cancer development are cancer-testis antigens (CTAs). This group of antigens has limited expression in the normal adult tissues but aberrant expression in cancers. This property provides them the possibility to be used as cancer biomarkers and immunotherapeutic targets. Several CTAs have been shown to be immunogenic in prostate cancer patients and some of the have entered clinical trials. Based on the preliminary data obtained from these trials, it is expected that CTA-based therapeutic options are beneficial for at least a subset of prostate cancer patients.

Ginkgolic acids induce HepG2 cell death via a combination of apoptosis, autophagy and the mitochondrial pathway

Ginkgolic acids may induce malignant cell death via the B-cell lymphoma 2 (Bcl-2)-associated X protein (Bax)/Bcl-2 apoptosis pathway. Concurrently, apoptosis, autophagy and mitochondrial dysfunction may also be involved in bringing about this endpoint. The anticancer effect of Ginkgolic acids (GAs) was investigated using the HepG2 cell line. The median lethal dose of the GAs of the HepG2 was measured via an MTT assay, the dose-response curves were evaluated and changes in cell morphology were monitored by microscopy. Autophagy in HepG2 cells was down regulated using 3-methyladenine (3-MA) or Beclin-1-specific small interfering RNA (siRNA) and the expression of apoptosis associated proteins caspase-3, Bax/Bcl-2, and the autophagy-associated protein 5 and microtubule-associated protein 1A/1B-light chain 3 in the GA-treated HepG2 cells were all measured by western blot analysis. The level of apoptosis in the GA-treated cells was also assessed using terminal deoxynucleotidyl-transferase-mediated dUTP nick-end labeling (TUNEL) assay, and the mitochondrial membrane potential (Δψ_m) was detected by immunofluorescence. The results of the MTT and TUNEL assays indicated that the proliferation of HepG2 cells treated with GAs was significantly reduced compared with the control group, and the rate of the inhibition was dose-dependent. Western blot analysis indicated that treatment with the Gas induced apoptosis and autophagy in the HepG2 cells. The Δψ_m of the GA-treated HepG2 cells was decreased compared with the control, as monitored by immunofluorescence. However, upon the administration of 3-MA or Beclin-1-specific siRNAs (inhibitors of the autophagy), the expression levels of the apoptosis- and autophagy-associated proteins were decreased. In conclusion, the results of the present study indicated that GAs are potent anticancer agents that function through a combination of the apoptosis, autophagy and mitochondrial pathways.

Treatment effects in prostate cancer

Nonsurgical treatments for prostate cancer include androgen-deprivation therapy (ADT), radiation therapy (RT), ablative therapies, chemotherapy, and newly emerging immunotherapies. These approaches can be used alone or in combination depending on the clinical scenario. ADT is typically reserved for high-risk locally or systemically advanced disease that is not amenable to curative surgery. Radiation therapy can be used instead of surgery as primary therapy with curative intent for low-intermediate-risk disease as well as for control of locally advanced disease not suitable for surgery. Ablative therapies can be used as primary therapy for low-intermediate-risk disease or as salvage therapy for clinically localized disease where RT has failed. Chemotherapy and immune-based therapies are currently used for androgen-independent disease, although the indications for these approaches may well change as new data from clinical trials accrue. Pathologists should be able to recognize tissue changes associated with these treatments to provide information that will optimize patient management. This is particularly true in situations where clinical history of recent or remote nonsurgical treatment is not provided with the specimen. In the absence of this information, pathologists encountering the features described herein are encouraged to review patient records or communicate directly with clinical colleagues to determine how a given patient was treated and when.

Screening the active compounds of Phellodendri Amurensis cortex for treating prostate cancer by high-throughput chinmedomics

Screening the active compounds of herbal medicines is of importance to modern drug discovery. In this work, an integrative strategy was established to discover the effective compounds and their therapeutic targets using Phellodendri Amurensis cortex (PAC) aimed at inhibiting prostate cancer as a case study. We found that PAC could be inhibited the growth of xenograft tumours of prostate cancer. Global constituents and serum metabolites were analysed by UPLC-MS based on the established chinmedomics analysis method, a total of 54 peaks in the spectrum of PAC were characterised in vitro and 38 peaks were characterised in vivo. Among the 38 compounds characterised in vivo, 29 prototype components were absorbed in serum and nine metabolites were identified in vivo. Thirty-four metabolic biomarkers were related to prostate cancer, and PAC could observably reverse these metabolic biomarkers to their normal level and regulate the disturbed metabolic profile to a healthy state. A chinmedomics approach showed that ten absorbed constituents, as effective compounds, were associated with the therapeutic effect of PAC. In combination with bioactivity assays, the action targets were also predicted and discovered. As an illustrative case study, the strategy was successfully applied to high-throughput screening of active compounds from herbal medicine.