CYTOKINE VARIATIONS IN PATIENTS WITH HORMONE TREATED PROSTATE CANCER

The role of autophagy in prostate cancer and prostatic diseases: a new therapeutic strategy

BACKGROUND

Autophagy is a well-conserved catabolic process that plays a key role in cell homeostasis. In the prostate, defective autophagy has been implicated in the genesis and progression of several pathological conditions.

AIM

The present review explored the autophagy pathway in prostate-related dysfunctions, focusing on prostate cancer (PCa), benign prostatic hyperplasia (BPH) and prostatitis.

RESULTS

Impaired autophagy activity has been shown in animal models of BPH and prostatitis. Moreover, autophagy activation by specific and non-specific drugs improved both conditions in pre-clinical studies. Conversely, the efficacy of autophagy inducers in PCa remains controversial, depending on intrinsic PCa characteristics and stage of progression. Intriguingly, autophagy inhibitors have shown beneficial effects in PCa suppression or even to overcome chemotherapy resistance. However, there are still open questions regarding the upstream mechanisms by which autophagy is deregulated in the prostate and the exact role of autophagy in PCa. The lack of specificity and increased toxicity associated with the currently autophagy inhibitors limits its use clinically, reflecting in reduced number of clinical data.

CONCLUSION

New therapeutic strategies to treat prostatic diseases involving new autophagy modulators, combination therapy and new drug formulations should be explored. Understanding the autophagy signaling in each prostatic disease is crucial to determine the best pharmacological approach.

The role of proinflammatory cytokines and CXC chemokines (CXCL1-CXCL16) in the progression of prostate cancer: insights on their therapeutic management

Reproductive cancers are malignancies that develop in the reproductive organs. One of the leading cancers affecting the male reproductive system on a global scale is prostate cancer (PCa). The negative consequences of PCa metastases endure and are severe, significantly affecting mortality and life quality for those who are affected. The association between inflammation and PCa has captured interest for a while. Inflammatory cells, cytokines, CXC chemokines, signaling pathways, and other elements make up the tumor microenvironment (TME), which is characterized by inflammation. Inflammatory cytokines and CXC chemokines are especially crucial for PCa development and prognosis. Cytokines (interleukins) and CXC chemokines such as IL-1, IL-6, IL-7, IL-17, TGF-β, TNF-α, CXCL1-CXCL6, and CXCL8-CXCL16 are thought to be responsible for the pleiotropic effects of PCa, which include inflammation, progression, angiogenesis, leukocyte infiltration in advanced PCa, and therapeutic resistance. The inflammatory cytokine and CXC chemokines systems are also promising candidates for PCa suppression and immunotherapy. Therefore, the purpose of this work is to provide insight on how the spectra of inflammatory cytokines and CXC chemokines evolve as PCa develops and spreads. We also discussed recent developments in our awareness of the diverse molecular signaling pathways of these circulating cytokines and CXC chemokines, as well as their associated receptors, which may one day serve as PCa-targeted therapies. Moreover, the current status and potential of theranostic PCa therapies based on cytokines, CXC chemokines, and CXC receptors (CXCRs) are examined.

Determination of enzalutamide long-term safety and efficacy for castration-resistant prostate cancer patients after combined anti-androgen blockade followed by alternative anti-androgen therapy: a multicenter prospective DELC study

BACKGROUND

Alternative anti-androgen therapy has been widely used as a first-line treatment for castration-resistant prostate cancer, and it may affect treatment outcome of subsequent agents targeting the androgen receptor axis. We conducted the prospective observational DELC (Determination of Enzalutamide Long-term safety and efficacy for Castration-resistant prostate cancer patients after combined anti-androgen blockade followed by alternative anti-androgen therapy) study to evaluate the efficacy of enzalutamide in patients with castration-resistant prostate cancer who underwent prior combined androgen blockade with bicalutamide and then alternative anti-androgen therapy with flutamide.

METHODS

The DELC study enrolled 163 Japanese patients with castration-resistant prostate cancer who underwent alternative anti-androgen therapy with flutamide following failure of initial combined androgen blockade with bicalutamide in multiple institutions between January 2016 and March 2019. Primary endpoint was overall survival. Administration of enzalutamide was started at 160 mg orally once daily in all patients.

RESULTS

The rate of decline of prostate-specific antigen by 50% or more was 72.2%, and median overall survival was 42.05 months. Multivariate analysis revealed that higher pretreatment serum levels of prostate-specific antigen (≥11.3 ng/mL; P = 0.004), neuron-specific enolase (P = 0.014) and interleukin-6 (≥2.15 pg/mL; P = 0.004) were independent risk factors for overall survival. Fatigue (30.0%), constipation (19.6%) and appetite loss (17.8%) were the most common clinically relevant adverse events. The enzalutamide dose was not reduced in any patient under the age of 70, but adherence was decreased in those over 70.

CONCLUSIONS

In the DELC study, the safety of enzalutamide was comparable to that in previous reports. Serum levels of neuron-specific enolase and interleukin-6 were suggested as prognostic factors for castration-resistant prostate cancer with potential clinical utility.

Inflammation in Prostate Cancer: Exploring the Promising Role of Phenolic Compounds as an Innovative Therapeutic Approach

Prostate cancer (PCa) remains a significant global health concern, being a major cause of cancer morbidity and mortality worldwide. Furthermore, profound understanding of the disease is needed. Prostate inflammation caused by external or genetic factors is a central player in prostate carcinogenesis. However, the mechanisms underlying inflammation-driven PCa remain poorly understood. This review dissects the diagnosis methods for PCa and the pathophysiological mechanisms underlying the disease, clarifying the dynamic interplay between inflammation and leukocytes in promoting tumour development and spread. It provides updates on recent advances in elucidating and treating prostate carcinogenesis, and opens new insights for the use of bioactive compounds in PCa. Polyphenols, with their noteworthy antioxidant and anti-inflammatory properties, along with their synergistic potential when combined with conventional treatments, offer promising prospects for innovative therapeutic strategies. Evidence from the use of polyphenols and polyphenol-based nanoparticles in PCa revealed their positive effects in controlling tumour growth, proliferation, and metastasis. By consolidating the diverse features of PCa research, this review aims to contribute to increased understanding of the disease and stimulate further research into the role of polyphenols and polyphenol-based nanoparticles in its management.

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.

Immunotherapy in Prostate Cancer: State of Art and New Therapeutic Perspectives

Prostate cancer (PC) is the most common type of tumor in men. In the early stage of the disease, it is sensitive to androgen deprivation therapy. In patients with metastatic castration-sensitive prostate cancer (mHSPC), chemotherapy and second-generation androgen receptor therapy have led to increased survival. However, despite advances in the management of mHSPC, castration resistance is unavoidable and many patients develop metastatic castration-resistant disease (mCRPC). In the past few decades, immunotherapy has dramatically changed the oncology landscape and has increased the survival rate of many types of cancer. However, immunotherapy in prostate cancer has not yet given the revolutionary results it has in other types of tumors. Research into new treatments is very important for patients with mCRPC because of its poor prognosis. In this review, we focus on the reasons for the apparent intrinsic resistance of prostate cancer to immunotherapy, the possibilities for overcoming this resistance, and the clinical evidence and new therapeutic perspectives regarding immunotherapy in prostate cancer with a look toward the future.

Hematopoietic Prostaglandin D2 Synthase Controls Tfh/Th2 Communication and Limits Tfh Antitumor Effects

T follicular helper (Tfh) cells are a subset of CD4+ T cells essential in immunity and have a role in helping B cells produce antibodies against pathogens. However, their role during cancer progression remains unknown. The mechanism of action of Tfh cells remains elusive because contradictory data have been reported on their protumor or antitumor responses in human and murine tumors. Like Tfh cells, Th2 cells are also involved in humoral immunity and are regularly associated with tumor progression and poor prognosis, mainly through their secretion of IL4. Here, we showed that Tfh cells expressed hematopoietic prostaglandin D2 (PGD2) synthase in a pSTAT1/pSTAT3-dependent manner. Tfh cells produced PGD2, which led to recruitment of Th2 cells via the PGD2 receptor chemoattractant receptor homologous molecule expressed on Th type 2 cells (CRTH2) and increased their effector functions. This cross-talk between Tfh and Th2 cells promoted IL4-dependent tumor growth. Correlation between Th2 cells, Tfh cells, and hematopoietic PGD2 synthase was observed in different human cancers and associated with outcome. This study provides evidence that Tfh/Th2 cross-talk through PGD2 limits the antitumor effects of Tfh cells and, therefore, could serve as a therapeutic target.

The Correlation Between Platelet Count and Survival in Prostate Cancer

Purpose

A number of studies have confirmed that elevated platelet count accompanying various solid tumours is associated with worse survival. However, only meagre data are available on the relationship between thrombocytosis and survival in prostate cancer.

Methods

We conducted a retrospective analysis on clinical-pathological data accumulated from 316 patients during on average 51 months of follow-up after laparoscopic prostatectomy performed for prostate cancer. We analyzed the relationship between platelet count, risk factors, prostate-specific antigen (PSA) and cancer stage with use the Tumor, Node, Metastase system (TNM), as well as surgical margin, and prognosis.

Results

Thrombocytosis occurred in only one out of the 316 patients. The multivariate Cox proportional hazard model showed that preoperative PSA, risk group, preoperative haemoglobin level, and surgical margin status were significant, independent predictors of biochemical progression-free survival. By contrast, age at diagnosis and thrombocytosis had no such predictive value.

Conclusion

We could not demonstrate an association between elevated platelet count and worse survival in our study population of patients with prostate cancer.

Immunotherapy in Advanced Prostate Cancer-Light at the End of the Tunnel?

Immunotherapeutic treatment approaches are now an integral part of the treatment of many solid tumors. However, attempts to integrate immunotherapy into the treatment of prostate cancer have been disappointing so far. This is due to a highly immunosuppressive, "cold" tumor microenvironment, which is characterized, for example, by the absence of cytotoxic T cells, an increased number of myeloid-derived suppressor cells or regulatory T cells, a decreased number of tumor antigens, or a defect in antigen presentation. The consequence is a reduced efficacy of many established immunotherapeutic treatments such as checkpoint inhibitors. However, a growing understanding of the underlying mechanisms of tumor-immune system interactions raises hopes that immunotherapeutic strategies can be optimized in the future. The aim of this review is to provide an overview of the current status and future directions of immunotherapy development in prostate cancer. Background information on immune response and tumor microenvironment will help to better understand current therapeutic strategies under preclinical and clinical development.

Metabolic profiling of prostate cancer in skeletal microenvironments identifies G6PD as a key mediator of growth and survival

The spread of cancer to bone is invariably fatal, with complex cross-talk between tumor cells and the bone microenvironment responsible for driving disease progression. By combining in silico analysis of patient datasets with metabolomic profiling of prostate cancer cells cultured with bone cells, we demonstrate the changing energy requirements of prostate cancer cells in the bone microenvironment, identifying the pentose phosphate pathway (PPP) as elevated in prostate cancer bone metastasis, with increased expression of the PPP rate-limiting enzyme glucose-6-phosphate dehydrogenase (G6PD) associated with a reduction in progression-free survival. Genetic and pharmacologic manipulation demonstrates that G6PD inhibition reduces prostate cancer growth and migration, associated with changes in cellular redox state and increased chemosensitivity. Genetic blockade of G6PD in vivo results in reduction of tumor growth within bone. In summary, we demonstrate the metabolic plasticity of prostate cancer cells in the bone microenvironment, identifying the PPP and G6PD as metabolic targets for the treatment of prostate cancer bone metastasis.

Influence of Systemic Therapy on the Expression and Activity of Selected STAT Proteins in Prostate Cancer Tissue

Signal Transducer and Activator of Transcription (STAT) proteins have been identified as drivers of prostate cancer (PCa) progression and development of aggressive castration-resistant phenotypes. In particular, STAT3, 5, and 6 have been linked to resistance to androgen receptor inhibition and metastasis in in vitro and in vivo models. This descriptive study aimed to validate these preclinical data in tissue obtained from patients with PCa before and while under androgen-deprivation therapy. Therefore, STAT3, 5, and 6 expressions and activity were assessed by immunohistochemistry. The data revealed that STAT3 and 5 changed in PCa. However, there was no relationship between expression and survival. Moreover, due to the heterogeneous nature of PCa, the preclinical results could not be transferred congruently to the patient’s material. A pilot study with a longitudinal patient cohort could also show this heterogeneous influence of systemic therapy on STAT3, 5, and 6 expressions and activity. Even if the main mechanisms were validated, these data demonstrate the urge for better patient-near preclinical models. Therefore, these data reflect the need for investigations of STAT proteins in a longitudinal patient cohort to identify factors responsible for the diverse influence of system therapy on STAT expression.

Signal Integration by Translocation and Phosphorylation of PKCδ in the B Cell Alternate Pathway

B cell signaling for activation via the BCR occurs as an isolated event only in vitro; in real life, BCR signaling takes place within a complex milieu that involves interactions with agents that trigger additional receptors. Chief among these is IL-4. We have shown that BCR signaling is reprogrammed by IL-4 receptor engagement and that this reprogramming involves creation of a new, signalosome-independent, Lyn-dependent alternate signaling pathway in B cells isolated from BALB/cByJ mice. A unique aspect of the alternate pathway is protein kinase Cδ (PKCδ) phosphorylation. In dissecting this pathway, we unexpectedly found that Lyn is associated with IL-4Rα, that IL-4 induces Lyn activation, and that Lyn immunoprecipitated from IL-4-treated B cells capably phosphorylates PKCδ in a cell-free system. However, PKCδ phosphorylation does not occur in the absence of BCR triggering in vivo. This raised the question of why IL-4 alone failed to produce PKCδ phosphorylation. We considered the possibility that Lyn and PKCδ may be spatially separated. As expected, before any treatment, Lyn is located primarily in the membrane fraction, whereas PKCδ is located mainly in the cytosol fraction. However, when anti-Ig follows IL-4 treatment, PKCδ is found in the membrane fraction and phosphorylated. This translocation of PKCδ to the membrane fraction is not affected by loss of Lyn, although PKCδ phosphorylation requires Lyn. Thus, PKCδ phosphorylation through the alternate pathway represents the result of signal integration, whereby neither IL-4 nor anti-Ig working alone produces this outcome, but together they achieve this result by Lyn activation (IL-4) and PKCδ translocation (IL-4 followed by anti-Ig).

Single-cell analysis reveals androgen receptor regulates the ER-to-Golgi trafficking pathway with CREB3L2 to drive prostate cancer progression

Androgen receptor (AR) plays a central role in driving prostate cancer (PCa) progression. How AR promotes this process is still not completely clear. Herein, we used single-cell transcriptome analysis to reconstruct the transcriptional network of AR in PCa. Our work shows AR directly regulates a set of signature genes in the ER-to-Golgi protein vesicle-mediated transport pathway. The expression of these genes is required for maximum androgen-dependent ER-to-Golgi trafficking, cell growth, and survival. Our analyses also reveal the signature genes are associated with PCa progression and prognosis. Moreover, we find inhibition of the ER-to-Golgi transport process with a small molecule enhanced antiandrogen-mediated tumor suppression of hormone-sensitive and insensitive PCa. Finally, we demonstrate AR collaborates with CREB3L2 in mediating ER-to-Golgi trafficking in PCa. In summary, our findings uncover a critical role for dysregulation of ER-to-Golgi trafficking expression and function in PCa progression, provide detailed mechanistic insights for how AR tightly controls this process, and highlight the prospect of targeting the ER-to-Golgi pathway as a therapeutic strategy for advanced PCa.

Second-Generation Jak2 Inhibitors for Advanced Prostate Cancer: Are We Ready for Clinical Development?

Simple Summary

Prostate Cancer (PC) is currently estimated to affect 1 in 9 men and is the second leading cause of cancer in men in the US. While androgen deprivation therapy, which targets the androgen receptor, is one of the front-line therapies for advanced PC and for recurrence of organ-confined PC treated with surgery, lethal castrate-resistant PC develops consistently in patients. PC is a multi-focal cancer with different grade carcinoma areas presenting simultaneously. Jak2-Stat5 signaling pathway has emerged as a potentially highly effective molecular target in PCs with positive areas for activated Stat5 protein. Activated Jak2-Stat5 signaling can be readily targeted by the second-generation Jak2-inhibitors that have been developed for myeloproliferative and autoimmune disorders and hematological malignancies. In this review, we analyze and summarize the Jak2 inhibitors that are currently in preclinical and clinical development.

Abstract

Androgen deprivation therapy (ADT) for metastatic and high-risk prostate cancer (PC) inhibits growth pathways driven by the androgen receptor (AR). Over time, ADT leads to the emergence of lethal castrate-resistant PC (CRPC), which is consistently caused by an acquired ability of tumors to re-activate AR. This has led to the development of second-generation anti-androgens that more effectively antagonize AR, such as enzalutamide (ENZ). However, the resistance of CRPC to ENZ develops rapidly. Studies utilizing preclinical models of PC have established that inhibition of the Jak2-Stat5 signaling leads to extensive PC cell apoptosis and decreased tumor growth. In large clinical cohorts, Jak2-Stat5 activity predicts PC progression and recurrence. Recently, Jak2-Stat5 signaling was demonstrated to induce ENZ-resistant PC growth in preclinical PC models, further emphasizing the importance of Jak2-Stat5 for therapeutic targeting for advanced PC. The discovery of the Jak2V617F somatic mutation in myeloproliferative disorders triggered the rapid development of Jak1/2-specific inhibitors for a variety of myeloproliferative and auto-immune disorders as well as hematological malignancies. Here, we review Jak2 inhibitors targeting the mutated Jak2V617F vs. wild type (WT)-Jak2 that are currently in the development pipeline. Among these 35 compounds with documented Jak2 inhibitory activity, those with potency against WT-Jak2 hold strong potential for advanced PC therapy.

Association between Helicobacter pylori infection and mortality risk in prostate cancer patients receiving androgen deprivation therapy: A real-world evidence study

Purpose

Helicobacter pylori (H. pylori) is a major risk factor for gastric cancer and may affect androgen activity in men. The association between H. pylori and androgen deprivation therapy (ADT) in patients with prostate cancer (PCa) remains unclear.

Methods

This retrospective cohort study linked National Health Insurance (NHI) data to Taiwan Cancer Registry (TCR) and Taiwan Death Registry (TDR) between 1995 and 2016. PCa patients who received ADT were classified into H. pylori infection and non‐H. pylori infection groups. The outcomes were overall mortality, prostate cancer‐specific mortality, and castration‐resistant prostate cancer (CRPC). Propensity score matching was adopted for the primary analysis and inverse probability of treatment weighting (IPTW) was used for the sensitivity analysis.

Results

Of the 62,014 selected PCa patients, 23,701 received ADT, of whom 3516 had H. pylori infections and 20,185 did not. After matching, there were 3022 patients in the H. pylori infection group and 6044 patients in the non‐H. pylori infection group. The mean follow‐up period for the matched cohort was 4.8 years. Compared to the non‐H. pylori group, the H. pylori group was significantly associated with decreased risks of all‐cause mortality (hazard ratio [HR] 0.90; 95% confidence interval [CI] 0.84–0.96) and prostate cancer‐specific mortality (HR 0.88; 95% CI 0.81–0.95) in the matched analysis.

Conclusions

H. pylori infection was associated with a reduced risk of mortality in PCa patients receiving ADT.

Blood-Derived Biomarkers of Diagnosis, Prognosis and Therapy Response in Prostate Cancer Patients

Prostate cancer is among the most frequent cancers in men worldwide. Despite the fact that multiple therapeutic alternatives are available for its treatment, it is often discovered in an advanced stage as a metastatic disease. Prostate cancer screening is based on physical examination of prostate size and prostate-specific antigen (PSA) level in the blood as well as biopsy in suspect cases. However, these markers often fail to correctly identify the presence of cancer, or their positivity might lead to overdiagnosis and consequent overtreatment of an otherwise silent non-progressing disease. Moreover, these markers have very limited if any predictive value regarding therapy response or individual risk for therapy-related toxicities. Therefore, novel, optimally liquid biopsy-based (blood-derived) markers or marker panels are needed, which have better prognostic and predictive value than the ones currently used in the everyday routine. In this review the role of circulating tumour cells, extracellular vesicles and their microRNA content, as well as cellular and soluble immunological and inflammation- related blood markers for prostate cancer diagnosis, prognosis and prediction of therapy response is discussed. A special emphasis is placed on markers predicting response to radiotherapy and radiotherapy-related late side effects.

Immunohistochemical expression of interlukin10 (IL10) and heat shock protein-90 (HSP-90) in prostatic carcinoma

Background

Specific cytokines are related to pathologically changed prostate, propose that the balance in cytokine differs in normal and pathological prostate. Of these cytokines the interleukins 10, due to its "pleiotropic" actions in inflammation and angiogenesis, and HSP-90 due to its expression in tumor cells at high levels, suggesting that it has an important role for growth and/or survival of tumor cells.

Aims

Evaluation of HSP-90 and IL10 immunoreactivity in benign prostatic hyperplasia (BPH) and prostatic carcinoma and to correlate this expression with clinicopathological parameters.

Settings and Design

A retrospective study in which 83 Paraffin-embedded tissue specimens including (43) BPH, (40) prostatic carcinoma and (20) normal prostate as control were included between the period of January 2015 and January 2017.

Patients, Material and Methods

All the cases were evaluated histopathologically and stained immunohistochemically for IL10 and HSP-90. Only cytoplasmic staining was considered as positive. Immunoreactivity scoring for both markers expression was calculated based on both staining intensity and percentage.

Statistical Analysis

Was done using SPSS Version 21 statistical analysis software. P value of <0.05 was considered statistically significant.

Result

Statistical analysis of HSP-90 and IL10 expression revealed a highly significant correlation of expression of these two markers in advanced Gleason grading and tumor, node, and metastasis (TNM) staging cases of prostatic carcinoma.

Conclusion

High expression of IL10 and HSP-90 is associated with high grade and stage of prostatic carcinoma. This provides a base for further studies and researches on the role of these investigated proteins as prognostic markers immunotherapy targets for carcinoma of the prostate.

SFMBT2-Mediated Infiltration of Preadipocytes and TAMs in Prostate Cancer

Infiltration of diverse cell types into tumor microenvironment plays a critical role in cancer progression including metastasis. We previously reported that SFMBT2 (Scm-like with four mbt domains 2) regulates the expression of matrix metalloproteinases (MMPs) and migration and invasion of cancer cells in prostate cancer. Here we investigated whether the down-regulation of SFMBT2 regulates the infiltration of preadipocytes and tumor-associated macrophages (TAMs) in prostate cancer. We found that the down-regulation of SFMBT2 promotes the infiltration of preadipocytes and TAMs through up-regulation of CXCL8, CCL2, CXCL10, and CCL20 expression in prostate cancer. Expression of CXCL8, CCL2, CXCL10, and CCL20 was also elevated in prostate cancer patients having a higher Gleason score (≥8), which had substantially lower SFMBT2 expression. We also found that the up-regulation of CXCL8, CCL2, CXCL10, and CCL20 expression is dependent on NF-κB activation in prostate cancer cells expressing a low level of SFMBT2. Moreover, increased IL-6 from infiltrated preadipocytes and TAMs promoted migration and invasion of prostate cancer cells expressing a low level of SFMBT2. Our study may suggest that SFMBT2 a critical regulator for the infiltration of preadipocytes and TAMs into the prostate tumor microenvironment. Thus, the regulation of SFMBT2 may provide a new therapeutic strategy to inhibit prostate cancer metastasis, and SFMBT2 could be used as a potential biomarker in prostate cancer metastasis.

Identification of LIMK2 as a therapeutic target in castration resistant prostate cancer

This study identified LIMK2 kinase as a disease-specific target in castration resistant prostate cancer (CRPC) pathogenesis, which is upregulated in response to androgen deprivation therapy, the current standard of treatment for prostate cancer. Surgical castration increases LIMK2 expression in mouse prostates due to increased hypoxia. Similarly, human clinical specimens showed highest LIMK2 levels in CRPC tissues compared to other stages, while minimal LIMK2 was observed in normal prostates. Most notably, inducible knockdown of LIMK2 fully reverses CRPC tumorigenesis in castrated mice, underscoring its potential as a clinical target for CRPC. We also identified TWIST1 as a direct substrate of LIMK2, which uncovered the molecular mechanism of LIMK2-induced malignancy. TWIST1 is strongly associated with CRPC initiation, progression and poor prognosis. LIMK2 increases TWIST1 mRNA levels upon hypoxia; and stabilizes TWIST1 by direct phosphorylation. TWIST1 also stabilizes LIMK2 by inhibiting its ubiquitylation. Phosphorylation-dead TWIST1 acts as dominant negative and fully prevents EMT and tumor formation in vivo, thereby highlighting the significance of LIMK2-TWIST1 signaling axis in CRPC. As LIMK2 null mice are viable, targeting LIMK2 should have minimal collateral toxicity, thereby improving the overall survival of CRPC patients.

Prostate cancer and inflammation: A new molecular imaging challenge in the era of personalized medicine

The relationship between cancer and inflammation is one of the most important fields for both clinical and translational research. Despite numerous studies reported interesting and solid data about the prognostic value of the presence of inflammatory infiltrate in cancers, the biological role of inflammation in prostate cancer development is not yet fully clarified. The characterization of molecular pathways that connect altered inflammatory response and prostate cancer progression can provide the scientific rationale for the identification of new prognostic and predictive biomarkers. Specifically, the detection of infiltrating immune cells or related-cytokines by histology and/or by molecular imaging techniques could profoundly change the management of prostate cancer patients. In this context, the anatomic pathology and imaging diagnostic teamwork can provide a valuable support for the validation of new targets for diagnosis and therapy of prostate cancer lesions associated to the inflammatory infiltrate. The aim of this review is to summarize the current literature about the role of molecular imaging technique and anatomic pathology in the study of the mutual interaction occurring between prostate cancer and inflammation. Specifically, we reported the more recent advances in molecular imaging and histological methods for the early detection of prostate lesions associated to the inflammatory infiltrate.

Anti-Cancer Effects of Green Tea Polyphenols Against Prostate Cancer

Prostate cancer is the most common cancer among men. Green tea consumption is reported to play an important role in the prevention of carcinogenesis in many types of malignancies, including prostate cancer; however, epidemiological studies show conflicting results regarding these anti-cancer effects. In recent years, in addition to prevention, many investigators have shown the efficacy and safety of green tea polyphenols and combination therapies with green tea extracts and anti-cancer agents in in vivo and in vitro studies. Furthermore, numerous studies have revealed the molecular mechanisms of the anti-cancer effects of green tea extracts. We believe that improved understanding of the detailed pathological roles at the molecular level is important to evaluate the prevention and treatment of prostate cancer. Therefore, in this review, we present current knowledge regarding the anti-cancer effects of green tea extracts in the prevention and treatment of prostate cancer, with a particular focus on the molecular mechanisms of action, such as influencing tumor growth, apoptosis, androgen receptor signaling, cell cycle, and various malignant behaviors. Finally, the future direction for the use of green tea extracts as treatment strategies in patients with prostate cancer is introduced.

Lipid pathway deregulation in advanced prostate cancer

The link between prostate cancer (PC) development and lipid metabolism is well established, with AR intimately involved in a number of lipogenic processes involving SREBP1, PPARG, FASN, ACC, ACLY and SCD1. Recently, there is growing evidence implicating the role of obesity and peri-prostatic adipose tissue (PPAT) in PC aggressiveness and related mortality, suggesting the importance of lipid pathways in both localised and disseminated disease. A number of promising agents are in development to target the lipogenic axis in PC, and the likelihood is that these agents will form part of combination drug strategies, with targeting of multiple metabolic pathways (e.g. FASN and CPT1), or in combination with AR pathway inhibitors (SCD1 and AR).

REST reduction is essential for hypoxia-induced neuroendocrine differentiation of prostate cancer cells by activating autophagy signaling

Prostate cancer (PCa) with neuroendocrine differentiation (NED) is tightly associated with hormone refractory PCa (HRPC), an aggressive form of cancer that is nearly impossible to treat. Determining the mechanism of the development of NED may yield novel therapeutic strategies for HRPC. Here, we first demonstrate that repressor element-1 silencing transcription factor (REST), a transcriptional repressor of neuronal genes that has been implicated in androgen-deprivation and IL-6 induced NED, is essential for hypoxia-induced NED of PCa cells. Bioinformatics analysis of transcriptome profiles of REST knockdown during hypoxia treatment demonstrated that REST is a master regulator of hypoxia-induced genes. Gene set enrichment analysis (GSEA) of hypoxia and REST knockdown co-upregulated genes revealed their correlation with HRPC. Consistently, gene ontology (GO) analysis showed that REST reduction potential associated with hypoxia-induced tumorigenesis, NE development, and AMPK pathway activation. Emerging reports have revealed that AMPK activation is a potential mechanism for hypoxia-induced autophagy. In line with this, we demonstrate that REST knockdown alone is capable of activating AMPK and autophagy activation is essential for hypoxia-induced NED of PCa cells. Here, making using of in vitro cell-based assay for NED, we reveal a new role for the transcriptional repressor REST in hypoxia-induced NED and characterized a sequential molecular mechanism downstream of REST resulting in AMPK phosphorylation and autophagy activation, which may be a common signaling pathway leading to NED of PCa.

Interleukin-6 and Interferon-α Signaling via JAK1-STAT Differentially Regulate Oncolytic versus Cytoprotective Antiviral States

Malignancy-induced alterations to cytokine signaling in tumor cells differentially regulate their interactions with the immune system and oncolytic viruses. The abundance of inflammatory cytokines in the tumor microenvironment suggests that such signaling plays key roles in tumor development and therapy efficacy. The JAK-STAT axis transduces signals of interleukin-6 (IL-6) and interferons (IFNs), mediates antiviral responses, and is frequently altered in prostate cancer (PCa) cells. However, how activation of JAK-STAT signaling with different cytokines regulates interactions between oncolytic viruses and PCa cells is not known. Here, we employ LNCaP PCa cells, expressing (or not) JAK1, activated (or not) with IFNs (α or γ) or IL-6, and infected with RNA viruses of different oncolytic potential (EHDV-TAU, hMPV-GFP, or HIV-GFP) to address this matter. We show that in JAK1-expressing cells, IL-6 sensitized PCa cells to viral cell death in the presence or absence of productive infection, with dependence on virus employed. Contrastingly, IFNα induced a cytoprotective antiviral state. Biochemical and genetic (knockout) analyses revealed dependency of antiviral state or cytoprotection on STAT1 or STAT2 activation, respectively. In IL-6-treated cells, STAT3 expression was required for anti-proliferative signaling. Quantitative proteomics (SILAC) revealed a core repertoire of antiviral IFN-stimulated genes, induced by IL-6 or IFNs. Oncolysis in the absence of productive infection, induced by IL-6, correlated with reduction in regulators of cell cycle and metabolism. These results call for matching the viral features of the oncolytic agent, the malignancy-induced genetic-epigenetic alterations to JAK/STAT signaling and the cytokine composition of the tumor microenvironment for efficient oncolytic virotherapy.

Interleukin-4 induces a CD44high /CD49bhigh PC3 subpopulation with tumor-initiating characteristics

Pro‐ and anti‐inflammatory cytokines may influence proliferation, migration, invasion, and other cellular events of prostate cancer (PCa) cells. The hyaluronan receptor CD44, which is regulated by Interleukin (IL)‐4, is a prostate basal cell marker. CD44_high/CD49b_high expressing cells have been demonstrated to have tumor‐initiating characteristics. Here, we aimed to analyze the effects of long‐term IL‐4 treatment on CD44/CD49b expression, migration, proliferation, and clonogenic potential of basal‐like PCa cells. To this end PC3 cells were treated over 30 passages with 5 ng/mL IL‐4 (PC3‐IL4) resulting in an increased population of CD44_high expressing cells. This was concurrent with a clonal outgrowth of cuboid‐shaped cells, with increased size and light absorbance properties. Flow cytometry revealed that the PC3‐IL4 CD44_high expressing subpopulation corresponds to the CD49b_high population. Isolation of the PC3‐IL4 CD44_high/CD49b_high subpopulation via fluorescence‐associated cell sorting showed increased migrative, proliferative, and clonogenic potential compared to the CD44_low/CD49b_low subpopulation. In conclusion, IL‐4 increases a PC3 subpopulation with tumor‐initiating characteristics. Thus, IL‐4, similar to other cytokines may be a regulator of tumor‐initiation and hence, may present a suitable therapy target in combination with current treatment options.

Germline variants in IL4, MGMT and AKT1 are associated with prostate cancer-specific mortality: An analysis of 12,082 prostate cancer cases

Background

Prostate cancer (PCa) is a leading cause of mortality and genetic factors can influence tumour aggressiveness. Several germline variants have been associated with PCa-specific mortality (PCSM), but further replication evidence is needed.

Methods

Twenty-two previously identified PCSM-associated genetic variants were genotyped in seven PCa cohorts (12,082 patients; 1544 PCa deaths). For each cohort, Cox proportional hazards models were used to calculate hazard ratios and 95% confidence intervals for risk of PCSM associated with each variant. Data were then combined using a meta-analysis approach.

Results

Fifteen SNPs were associated with PCSM in at least one of the seven cohorts. In the meta-analysis, after adjustment for clinicopathological factors, variants in the MGMT (rs2308327; HR 0.90; p-value = 3.5 × 10⁻²) and IL4 (rs2070874; HR 1.22; p-value = 1.1 × 10⁻³) genes were confirmed to be associated with risk of PCSM. In analyses limited to men diagnosed with local or regional stage disease, a variant in AKT1, rs2494750, was also confirmed to be associated with PCSM risk (HR 0.81; p-value = 3.6 × 10⁻²).

Conclusions

This meta-analysis confirms the association of three genetic variants with risk of PCSM, providing further evidence that genetic background plays a role in PCa-specific survival. While these variants alone are not sufficient as prognostic biomarkers, these results may provide insights into the biological pathways modulating tumour aggressiveness.

High expression of IL-4R enhances proliferation and invasion of hepatocellular carcinoma cells

OBJECTIVE

In this study, we aimed to investigate the expression and function of interleukin-4 receptor (IL-4R) in hepatocellular carcinoma (HCC).

METHODS

We collected 40 pairs of human HCC and adjacent normal tissue specimens and examined the expression levels of IL-4R. After IL-4R knockdown in HCC cell lines, cell proliferation and invasion ability were examined. Cell cycle and apoptosis were analyzed by flow cytometry. The activity of multiple signaling pathways was examined by Western blot.

RESULTS

IL-4R was overexpressed in HCC tumors compared with adjacent normal control tissues and was associated with tumor differentiation status. IL-4R knockdown resulted in enhanced apoptosis, impaired proliferation and reduced invasion of HCC cells. Furthermore, IL-4R knockdown abolished IL-4-induced activation of the Janus Kinase 1 (JAK1)/signal transducer and activator of transcription 6 (STAT6) and JUN N-terminal kinase (JNK)/extracellular signal-regulated kinase 1/2 (ERK1/2) signaling pathways.

CONCLUSIONS

IL-4R plays an important role in regulating HCC cell survival and metastasis, and regulates the activity of the JAK1/STAT6 and JNK/ERK1/2 signaling pathways. We therefore suggest that IL-4/IL-4R may be a new therapeutic target for HCC.

Expression analysis of inflammasome sensors and implication of NLRP12 inflammasome in prostate cancer

Inflammasomes are multi-proteins complex regulating inflammation-associated signaling. While inflammation plays a critical role in cancer cell growth, studies remain uncharacterized on the role of inflammasomes in prostate cancer. Using Gene Expression Omnibus (GEO) public datasets, we screened the expression profiles of inflammasome sensors NLRP3, NLRC4, NLRP6, NRLP12, and AIM2 in prostate tumor tissues, and verified their mRNA level in a panel of prostate cancer cell lines. The selected expression of NLRP3 and NLRP12 inflammasomes was validated, and the clinical association was evaluated in human prostate archival tumor tissues. We observed that the expression of inflammasome sensors was dysregulated at the mRNA level except for the NLRP12. The intensity of NLRP12 immunostaining was significantly higher in malignant prostate as compared to their adjacent benign tissues. In contrast, the NLRP3 immunostaining in prostate tissues was heterogeneous. The inflammasome complex proteins ASC (apoptosis-associated speck-like protein containing a CARD) and pro-caspase-1, as well as its downstream targets IL-1β and IL-18 were confined to aggressive prostate cancer cells. These data suggest an increased expression of NLRP12 in association with prostate cancer and support the role of NLRP12 inflammasome complex regulating inflammatory cytokines in understanding the role of inflammation in the prostate cancer.

The immunosuppressive cytokine interleukin-4 increases the clonogenic potential of prostate stem-like cells by activation of STAT6 signalling

Interleukin-4 plays a critical role in the regulation of immune responses and has been detected at high levels in the tumour microenvironment of cancer patients, where concentrations correlate with the grade of malignancy. In prostate cancer, interleukin-4 has been associated with activation of the androgen receptor, increased proliferation and activation of survival pathways such as Akt and NF-κB. However, its role in therapy resistance has not yet been determined. Here we investigate the influence of interleukin-4 on primary epithelial cells from prostate cancer patients. Our data demonstrate an increase in the clonogenic potential of these cells when cultured in the presence of interleukin-4. In addition, a Phospho-Kinase Array revealed that in contrast to previously published work, signal transducer and activator of transcription6 (STAT6) is the only signalling molecule activated after interleukin-4 treatment. Using the STAT6-specific inhibitor AS1517499 we could confirm the role of STAT6 in increasing colony-forming frequency. However, clonogenic recovery assays revealed that interleukin-4 does not rescue the effects of either irradiation or docetaxel treatment. We therefore propose that although the interleukin-4/STAT6 axis does not appear to be involved in therapy resistance, it does play a crucial role in the colony-forming abilities of the basal cell population in prostate cancer. IL-4 may therefore contribute to disease relapse by providing a niche that is favourable for the clonogenic growth of prostate cancer stem cells.

Differentially Expressed Genes and Signature Pathways of Human Prostate Cancer

Genomic technologies including microarrays and next-generation sequencing have enabled the generation of molecular signatures of prostate cancer. Lists of differentially expressed genes between malignant and non-malignant states are thought to be fertile sources of putative prostate cancer biomarkers. However such lists of differentially expressed genes can be highly variable for multiple reasons. As such, looking at differential expression in the context of gene sets and pathways has been more robust. Using next-generation genome sequencing data from The Cancer Genome Atlas, differential gene expression between age- and stage- matched human prostate tumors and non-malignant samples was assessed and used to craft a pathway signature of prostate cancer. Up- and down-regulated genes were assigned to pathways composed of curated groups of related genes from multiple databases. The significance of these pathways was then evaluated according to the number of differentially expressed genes found in the pathway and their position within the pathway using Gene Set Enrichment Analysis and Signaling Pathway Impact Analysis. The “transforming growth factor-beta signaling” and “Ran regulation of mitotic spindle formation” pathways were strongly associated with prostate cancer. Several other significant pathways confirm reported findings from microarray data that suggest actin cytoskeleton regulation, cell cycle, mitogen-activated protein kinase signaling, and calcium signaling are also altered in prostate cancer. Thus we have demonstrated feasibility of pathway analysis and identified an underexplored area (Ran) for investigation in prostate cancer pathogenesis.

The receptor NLRP3 is a transcriptional regulator of TH2 differentiation

The receptor NLRP3 is involved in the formation of the NLRP3 inflammasome that activates caspase-1 and mediates the release of interleukin 1β (IL-1β) and IL-18. Whether NLRP3 can shape immunological function independently of inflammasomes is unclear. We found that NLRP3 expression in CD4(+) T cells specifically supported a T helper type 2 (TH2) transcriptional program in a cell-intrinsic manner. NLRP3, but not the inflammasome adaptor ASC or caspase-1, positively regulated a TH2 program. In TH2 cells, NLRP3 bound the Il4 promoter and transactivated it in conjunction with the transcription factor IRF4. Nlrp3-deficient TH2 cells supported melanoma tumor growth in an IL-4-dependent manner and also promoted asthma-like symptoms. Our results demonstrate the ability of NLRP3 to act as a key transcription factor in TH2 differentiation.

Polymorphisms in NFKB1 and NFKBIA Genes Modulate the Risk of Developing Prostate Cancer among Han Chinese

Background

Nuclear factor kappa B (NF-κB) pathway proteins play an important role in modulating inflammation and other carcinogenic processes. Polymorphisms within NF-κB pathway genes may influence cancer risk. This study aimed to examine the association between NFKB19-4 ATTG ins→del, NFKBIA 3′ UTR A→G, -826CT and -881AG polymorphisms and prostate cancer risk among Chinese.

Material/Methods

The polymorphisms were genotyped via PCR-RFLP technique on 936 prostate cancer patients and 936 population-based healthy controls. Logistic regression model was used to measure the risk association present.

Results

With the exception of NFKBIA 3′ UTR polymorphism, the heterozygous and mutant genotypes of the other polymorphisms were significantly associated with prostate cancer risk. For NFKB1 polymorphism, a decreased risk was observed, with adjusted OR: 0.69; 95% CI: 0.44, 0.98; P=0.01 (heterozygous) and adjusted OR: 0.60; 95% CI: 0.37, 0.91; P=0.02 (mutant). NFKBIA -826CT and -881AG polymorphisms were in complete linkage disequilibrium and shared the same risk association, with adjusted OR: 1.34; 95% CI: 1.09, 1.62; P=0.02 (heterozygous) and adjusted OR: 2.83; 95% CI: 1.79, 4.50; P=0.01 (mutants). Interestingly, the impact of the NFKB1 polymorphism was not present in nonsmokers and younger (<60 years) subjects (P<0.05).

Conclusions

In conclusion, polymorphisms in NFKB1 and NFKBIA genes may modulate the risk of developing prostate cancer among Chinese.

Minireview: Tipping the balance: ligand-independent activation of steroid receptors

Steroid receptors are prototypical ligand-dependent transcription factors and a textbook example for allosteric regulation. According to this canonical model, binding of cognate steroid is an absolute requirement for transcriptional activation. Remarkably, the simple one ligand-one receptor model could not be farther from the truth. Steroid receptors, notably the sex steroid receptors, can receive multiple inputs. Activation of steroid receptors by other signals, working through their own signaling pathways, in the absence of the cognate steroids, represents the most extreme form of signaling cross talk. Compared with cognate steroids, ligand-independent activation pathways produce similar but not identical outputs. Here we review the phenomena and discuss what is known about the underlying molecular mechanisms and the biological significance. We hypothesize that steroid receptors may have evolved to be trigger happy. In addition to their cognate steroids, many posttranslational modifications and interactors, modulated by other signals, may be able to tip the balance.

Inflammation and prostate cancer: the role of interleukin 6 (IL-6)

Environmental and genetic aspects are reflected in the development of prostate cancer. In this context, there is growing evidence that chronic inflammation is involved in the regulation of cellular events in prostate carcinogenesis, including disruption of the immune response and regulation of the tumour microenvironment. One of the best surrogates of chronic inflammation in prostate cancer is interleukin 6 (IL-6). Serum IL-6 levels are elevated in patients with untreated metastatic or castration-resistant prostate cancer (CRPC) and correlate negatively with tumour survival and response to chemotherapy. Via multiple signal pathways including the Janus tyrosine family kinase (JAK)-signal transducer and activator of transcription (STAT) pathway, the extracellular signal-regulated kinase 1 and 2 (ERK1/2)-mitogen activated protein kinase (MAPK) pathway, and the phosphoinositide 3-kinase (PI3-K) pathway, IL-6 is able to promote prostate cancer cell proliferation and inhibit apoptosis in vitro and in vivo. IL-6 is associated with aggressive prostate cancer phenotype and may be involved in the metastatic process through regulation of epithelial-mesenchymal transition (EMT) and homing of cancer cells to the bone. A substantial body of evidence suggests that IL-6 plays a major role in the transition from hormone-dependent to CRPC, most notably through accessory activation of the androgen receptor. Collectively, these data have stimulated the development of agents targeting IL-6 signalling pathways. A chimeric anti-IL-6 monoclonal antibody has been tested in clinical trials, with mixed results.

Pharmacologic suppression of JAK1/2 by JAK1/2 inhibitor AZD1480 potently inhibits IL-6-induced experimental prostate cancer metastases formation

Metastatic prostate cancer is lethal and lacks effective strategies for prevention or treatment, requiring novel therapeutic approaches. Interleukin-6 (IL-6) is a cytokine that has been linked with prostate cancer pathogenesis by multiple studies. However, the direct functional roles of IL-6 in prostate cancer growth and progression have been unclear. In the present study, we show that IL-6 is produced in distant metastases of clinical prostate cancers. IL-6-activated signaling pathways in prostate cancer cells induced a robust 7-fold increase in metastases formation in nude mice. We further show that IL-6 promoted migratory prostate cancer cell phenotype, including increased prostate cancer cell migration, microtubule reorganization, and heterotypic adhesion of prostate cancer cells to endothelial cells. IL-6-driven metastasis was predominantly mediated by Stat3 and to lesser extent by ERK1/2. Most importantly, pharmacologic inhibition of Jak1/2 by AZD1480 suppressed IL-6-induced signaling, migratory prostate cancer cell phenotypes, and metastatic dissemination of prostate cancer in vivo in nude mice. In conclusion, we demonstrate that the cytokine IL-6 directly promotes prostate cancer metastasis in vitro and in vivo via Jak-Stat3 signaling pathway, and that IL-6-driven metastasis can be effectively suppressed by pharmacologic targeting of Jak1/2 using Jak1/2 inhibitor AZD1480. Our results therefore provide a strong rationale for further development of Jak1/2 inhibitors as therapy for metastatic prostate cancer.

Autophagy pathway is required for IL-6 induced neuroendocrine differentiation and chemoresistance of prostate cancer LNCaP cells

Prostate cancer (PCa) cells undergoing neuroendocrine differentiation (NED) are clinically relevant to the development of relapsed castration-resistant PCa. Increasing evidences show that autophagy involves in the development of neuroendocrine (NE) tumors, including PCa. To clarify the effect of autophagy on NED, androgen-sensitive PCa LNCaP cells were examined. Treatment of LNCaP cells with IL-6 resulted in an induction of autophagy. In the absence of androgen, IL-6 caused an even stronger activation of autophagy. Similar result was identified in NED induction. Inhibition of autophagy with chloroquine (CQ) markedly decreased NED. This observation was confirmed by beclin1 and Atg5 silencing experiments. Further supporting the role of autophagy in NED, we found that LC3 was up-regulated in PCa tissue that had relapsed after androgen-deprivation therapy when compared with their primary tumor counterpart. LC3 staining in relapsed PCa tissue showed punctate pattern similar to the staining of chromogranin A (CgA), a marker for NED cells. Moreover, autophagy inhibition induced the apoptosis of IL-6 induced NE differentiated PCa cells. Consistently, inhibition of autophagy by knockdown of beclin1 or Atg5 sensitized NE differentiated LNCaP cells to etoposide, a chemotherapy drug. To identify the mechanisms, phosphorylation of IL-6 downstream targets was analyzed. An increase in phospho-AMPK and a decrease in phospho-mTOR were found, which implies that IL-6 regulates autophagy through the AMPK/mTOR pathway. Most important to this study is the discovery of REST, a neuronal gene-specific transcriptional repressor that is involved in autophagy activation. REST was down-regulated in IL-6 treatment. Knockdown experiments suggest that REST is critical to NED and autophagy activation by IL-6. Together, our studies imply that autophagy is involved in PCa progression and plays a cytoprotective role when NED is induced in PCa cells by IL-6 treatment. These results reveal the potential of targeting autophagy as part of a combined therapeutic regime for NE tumors.

Endurance training improves insulin sensitivity and body composition in prostate cancer patients treated with androgen deprivation therapy

Insulin resistance and changes in body composition are side effects of androgen deprivation therapy (ADT) given to prostate cancer patients. The present study investigated whether endurance training improves insulin sensitivity and body composition in ADT-treated prostate cancer patients. Nine men undergoing ADT for prostate cancer and ten healthy men with normal testosterone levels underwent 12 weeks of endurance training. Primary endpoints were insulin sensitivity (euglycemic-hyperinsulinemic clamps with concomitant glucose-tracer infusion) and body composition (dual-energy X-ray absorptiometry and magnetic resonance imaging). The secondary endpoint was systemic inflammation. Statistical analysis was carried out using two-way ANOVA. Endurance training increased VO2max (ml(O2)/min per kg) by 11 and 13% in the patients and controls respectively (P<0.0001). The patients and controls demonstrated an increase in peripheral tissue insulin sensitivity of 14 and 11% respectively (P<0.05), with no effect on hepatic insulin sensitivity (P=0.32). Muscle protein content of GLUT4 (SLC2A4) and total AKT (AKT1) was also increased in response to the training (P<0.05 and P<0.01 respectively). Body weight (P<0.0001) and whole-body fat mass (FM) (P<0.01) were reduced, while lean body mass (P=0.99) was unchanged. Additionally, reductions were observed in abdominal (P<0.01), subcutaneous (P<0.05), and visceral (P<0.01) FM amounts. The concentrations of plasma markers of systemic inflammation were unchanged in response to the training. No group × time interactions were observed, except for thigh intermuscular adipose tissue (IMAT) (P=0.01), reflecting a significant reduction in the amount of IMAT in the controls (P<0.05) not observed in the patients (P=0.64). In response to endurance training, ADT-treated prostate cancer patients exhibited improved insulin sensitivity and body composition to a similar degree as eugonadal men.

Cell mates: paracrine and stromal targets for prostate cancer therapy

After many years of limited treatment options for patients with metastatic castration-resistant prostate cancer (mCRPC), multiple systemic therapies are now available, providing patients with significant improvements in survival, symptom control and bone health. Most of the recent advances in this area have been based on better understanding of mCRPC biology, particularly with respect to the key role of androgen receptor signalling. However, most therapies are targeted towards the malignant epithelial cell component of the cancer and it should not be forgotten that cancer cells exist in close and symbiotic relationships with other components of the tumour. Paracrine and stromal signals are often critical to the growth of the cancer and represent new potential therapeutic targets that are separate from the malignant epithelial cells. The stroma produces numerous growth factors, including vascular endothelial growth factor family members, platelet-derived growth factors and fibroblast growth factors, which are all critical for tumour growth. Targeting prostate-cancer-associated fibroblasts in order to destroy the physical and functional scaffold of a cancer is also a logical approach. The interaction between prostate cancer and the immune system remains an active topic of basic and clinical research, with cytokines, chemokines and growth factors being potential targets for therapy. The biology of epithelial-mesenchymal transition and of circulating tumour cells might also provide insight into new therapeutic targets.

Association of symptoms and cytokines in prostate cancer patients receiving radiation treatment

INTRODUCTION

Men with prostate cancer undergoing radiation treatment frequently report fatigue, insomnia, depression, anxiety and urinary, bowel, sexual, and hormonal symptoms. Plasma concentrations of cytokines may be related to these symptoms, but few studies have examined these relationships. The study purpose was to explore the association between prostate cancer symptoms and cytokine levels at pretreatment and posttreatment.

METHOD

In this longitudinal, correlational study, 29 men with nonmetastatic prostate cancer completed symptom questionnaires at preradiation and postradiation treatment. Blood drawn at these same time points was used to determine levels of tumor necrosis factor-alpha (TNF-α) and interleukins-1β, 6, 10, and 4 (IL-1β, IL-6, IL-10, and IL-4).

RESULTS

Men reported symptom severity at pretreatment and posttreatment as low to moderate. There were significant differences from pretreatment to posttreatment in fatigue, insomnia, urinary irritative and incontinence, bowel, sexual, and hormonal problems. There were no significant differences in TNF-α, IL-6, IL-10, or IL-4. At pretreatment, TNF-α was associated with depression, anxiety, urinary irritative, and bowel problems, and IL-4 was related to urinary irritative symptoms. At posttreatment, IL-4 was associated with urinary irritative symptoms. Findings suggest that, in men with prostate cancer, there is no strong association between symptom reporting and cytokine levels. Ongoing research focused on neuroendocrine and genetic markers and their associations with symptoms is promising and may result in the provision of better markers for quantifying the symptom experience in patients with cancer.

Cytokine stimulation of epithelial cancer cells: the similar and divergent functions of IL-4 and IL-13

The Th2 cytokines interleukin (IL)-4 and -13 are acknowledged regulators of lymphocyte proliferation and activation. They have also been well studied in the regulation of various myeloid-derived populations in tumor biology. It has become clear, however, that both cytokines can have direct effects on epithelial tumor cells expressing appropriate receptors. Changes in tumor proliferation, survival, and metastatic capability have all been ascribed to IL-4 and/or IL-13 action. Here, we evaluate the evidence to support direct tumor-promoting roles of these cytokines. We also identify the questions that should be addressed before proceeding with therapeutic approaches based on neutralization of IL-4 or IL-13 pathways.

Changes in biomarkers of inflammation and angiogenesis during androgen deprivation therapy for prostate cancer

INTRODUCTION

Angiogenesis and inflammation are both important to the pathogenesis of malignancies. Androgen deprivation therapy (ADT) for prostate cancer causes drastic hormonal changes that alter both disease and host factors. We measured inflammatory and angiogenic biomarkers in ADT-treated and control groups of men with prostate cancer.

MATERIALS AND METHODS

Baseline and 12-week plasma samples were collected from 37 ADT-naïve men with locally advanced or recurrent prostate cancer. Of those, 23 initiated ADT with a gonadotropin-releasing hormone (GnRH) agonist and 14 served as nontreatment controls. Samples were tested for a panel of angiogenic and inflammatory biomarkers.

RESULTS

The treatment group had significantly higher concentrations of the inflammatory biomarkers interleukin (IL)-1β, IL-6, IL-8, tumor necrosis factor (TNF)-α, and stromal cell-derived factor (SDF)-1α. None of the angiogenic biomarkers were significantly different between the groups at baseline. Among patients with a short prostate-specific antigen (PSA) doubling time (<6 months), the proangiogenic factor basic fibroblast growth factor (bFGF) was lower at baseline. In the treatment group, plasma placental growth factor (PlGF) increased and IL-6 decreased after 12 weeks of ADT. Moreover, the treatment group continued to have significantly higher concentrations of the inflammatory biomarkers IL-1β, IL-8, and SDF-1α as well as bFGF than controls.

DISCUSSION

These men were characterized by elevations in several traditional markers of aggressive disease and also by higher levels of several inflammatory biomarkers. Although ADT decreased IL-6 levels, IL-1β, IL-8, and SDF-1α remained significantly higher than in controls. The role of these biomarkers should be further explored.

Clinical investigation of the role of interleukin-4 and interleukin-13 in the evolution of prostate cancer

Prostate cancer is the most common cancer in men, both in the USA and Europe. Although incurable, metastatic disease can often be controlled for years with anti-androgen therapy. Once the disease becomes castrate resistant, the median survival is 18 months. There is growing evidence that the immune system, and in particular cytokines, play an important role in prostate cancer immunosurveillance and progression. Here, we have undertaken a clinical investigation of the role of two closely related cytokines, IL-4 and IL-13 in prostate cancer. In the largest series studied to date, we show that serum IL-4, but not IL-13 is significantly elevated in castrate resistant, compared to androgen sensitive disease. Notably however, serum IL-4 levels are also raised in patients with benign prostatic disease. Analysis of benign and malignant prostate tissue demonstrates that the source of IL-4 is epithelial cells rather than infiltrating leukocytes. Together, our data are consistent with a dual role for IL-4 in prostate cancer development. In benign disease, our data add to the evidence that IL-4 serves a protective role. By contrast, the data support a direct role for IL-4 in the progression of prostate cancer from androgen responsive, to advanced castrate-resistant disease.

The additional value of TGFβ1 and IL-7 to predict the course of prostate cancer progression

Background

Given the fact that prostate cancer incidence will increase in the coming years, new prognostic biomarkers are needed with regard to the biological aggressiveness of the prostate cancer diagnosed. Since cytokines have been associated with the biology of cancer and its prognosis, we determined whether transforming growth factor beta 1 (TGFβ1), interleukin-7 (IL-7) receptor and IL-7 levels add additional prognostic information with regard to prostate cancer-specific survival.

Materials and methods

Retrospective survival analysis of forty-four prostate cancer patients, that underwent radical prostatectomy, was performed (1989–2001). Age, Gleason score and pre-treatment PSA levels were collected. IL-7, IL-7 receptor and TGFβ1 levels in prostate cancer tissue were determined by quantitative real-time RT-PCR and their additional prognostic value analyzed with regard to prostate cancer survival. Hazard ratios and their confidence intervals were estimated, and Akaike’s information criterion was calculated for model comparison.

Results

The predictive ability of a model for prostate cancer survival more than doubled when TGFβ1 and IL-7 were added to a model containing only the Gleason score and pre-treatment PSA (AIC: 18.1 and AIC: 6.5, respectively).

Conclusion

IL-7 and TGFβ1 are promising markers to indicate those at risk for poor prostate cancer survival. This additional information may be of interest with regard to the biological aggressiveness of the diagnosed prostate cancer, especially for those patients screened for prostate cancer and their considered therapy.

Molecular chemotherapy and chemotherapy: a new front against late-stage hormone-refractory prostate cancer

PURPOSE

Stemming from its inherent heterogeneity, single-agent treatments are essentially ineffective against castration-resistant prostate cancer (CRPC). Thus, clinically relevant regimens that harness different modalities to maximize treatment efficacy without increasing cumulative toxicities are urgently needed. Based on this rationale, we investigated whether a novel combination of purine nucleoside phosphorylase-mediated, gene-directed enzyme-prodrug therapy (PNP-GDEPT) with docetaxel against CRPC has superior efficacy in comparison with individual treatments.

METHODS

The in vitro cell growth inhibition in differentially treated murine and human CRPC cell lines was established using a cell-viability assay. The extent of synergy, additivity, or antagonism between treatments was evaluated using CalcuSyn statistical analyses. The local and systemic effects of docetaxel and/or PNP-GDEPT were tested in both immunodeficient and immunocompetent mice against human and murine CRPC tumors, respectively. Subsequently, immunohistochemical analyses and an evaluation of serum cytokine and serum toxicity profiles were conducted to characterize the differential host responses to treatment.

RESULTS

The combined use of PNP-GDEPT and docetaxel led to strong synergistic cell killing in vitro. Compared with the individual modalities, a combination of the 2 led to a marked reduction in "local and distant" tumor growth in vivo, and importantly, with lowered doses and without additional toxicities. Immunomodulation was indicated by enhanced immune cell infiltration and altered serum cytokine levels. Furthermore, a lowering of T-helper type 2 cytokines, MCP-1, interleukin (IL)-4, IL-6, and IL-10 marked lower tumor burden and enhanced treatment efficacy.

CONCLUSION

PNP-GDEPT and docetaxel are a potent combination against CRPC in immunocompetent and immunodeficient settings; these outcomes have implications of translational potential for improved treatment and management of CRPC patients.

Genetic polymorphisms in inflammation pathway genes and prostate cancer risk

BACKGROUND

Chronic inflammation is an important mechanism for the development and progression of prostate cancer (PC). To better understand the potential relationship between genes in the inflammation pathway and PC risk, we evaluated variants in 16 candidate genes.

METHODS

A total of 143 tagging and amino acid altering single nucleotide polymorphisms (SNPs) were genotyped in Caucasian and African American men participating in one of two population-based, case-control studies (n = 1,458 cases and 1,351 controls). The relative risk of PC was estimated using logistic and polytomous regression models.

RESULTS

Ten SNPs in seven genes (CXCL12, IL4, IL6, IL6ST, PTGS2, STAT3, and TNF) were nominally associated (P < 0.05) with risk of PC in Caucasians. The most significant effect on risk was seen with rs11574783 in the interleukin 6 signal transducer (IL6ST) gene (OR = 0.08, 95% CI: 0.01-0.63). Cumulatively, four SNPs in genes interleukin 4 (IL4), IL6ST, PTGS2, and signal transducer and activator of transcription 3 (STAT3) conferred a three-fold elevation in PC risk among men carrying the maximum number of high-risk alleles (OR = 2.97, 95% CI: 1.41-6.25, P(trend) = 0.0003). Risk estimates for seven SNPs varied significantly according to disease aggressiveness (P(homogeneity) < 0.05), with SNPs in AKT1, PIK3R1, and STAT3 independently associated with more aggressive PC; OR = 5.1 (95% CI: 2.29-11.40, P(trend) = 3.8 × 10(-5)) for carriers of all high-risk genotypes.

CONCLUSIONS

These results suggest that variants in genes within the inflammation pathway may play a role in the development of PC, however, further studies are needed to replicate our findings.

IMPACT

These results underline the potential importance of the inflammation pathway in PC development and progression.

Clinical significance of preoperative serum interleukin-6 and C-reactive protein level in breast cancer patients

Background

Breast cancer is a disease that continues to plague females during their entire lifetime. IL-6 and CRP are found to be elevated in various inflammatory and malignant diseases and their levels are found to correlate with the extent of the disease. The primary objective of this study was to determine the preoperative serum levels of IL-6 and CRP in breast carcinoma, and to correlate them with the staging of the disease and the prognosis.

Methods

59 female patients admitted for breast cancer were identified for the study and were subjected to thorough evaluation. Serum levels of IL-6 were assessed via Enzyme-Linked Immuno-Sorbent Assay (ELISA), and CRP was measured via immunoturbidimetry. Histological findings included tumour size, lymph node (LN) metastasis, and tumour staging. Relevant investigations were made to find out the presence of distant metastasis. Statistical analysis of the data was then processed.

Results

Increases in cancer invasion and staging are generally associated with increases in preoperative serum IL-6 levels. IL-6 and CRP levels correlated with LN metastasis (P < 0.001, P < 0.001) and TNM stage (P < 0.001, P < 0.001). Tumour invasion and the presence of distant metastasis is associated with higher IL-6 levels (P = 0.001, P = 0.009). When we established the cutoff value for IL-6 level (20.55 pg/dl) by ROC curve, we noted a significant difference in overall survival (OS; P = 0.008). However, CRP evidenced no significance with regard to patient's OS levels. Serum IL-6 levels were correlated positively with CRP levels (r2 = 0.579, P < 0.01)

Conclusion

Serum levels of IL-6 correlates well with the extent of tumor invasion, LN metastasis, distant metastasis and TNM staging thus enveloping all aspects of breast cancer.

Cytokine disbalance in common human cancers

Interleukin (IL)-6, -4, and -8 levels have been elevated in most patients suffering from prostate, breast, or colon cancer. There is a large body of evidence suggesting that chronic inflammation is one of the etiologic factors in these tumors. IL-6 is a multifunctional cytokine which is known to influence proliferation, apoptosis, and angiogenesis in cancer. Its transcription factor STAT3 is known as an oncogene that is constitutively phosphorylated in these malignancies. However, IL-6-induced STAT3 phosphorylation may result in growth arrest. IL-6 activation of androgen receptor in prostate cancer may yield either tumor cell proliferation or differentiation. Prolonged treatment with IL-6 results in generation of sublines which express a more malignant phenotype. Therapy options against IL-6 have been established and the antibody siltuximab has been applied in preclinical and clinical studies. Recently, investigations of the role of suppressors of cytokine signaling have been carried out. IL-4 and -8 are implicated in regulation of apoptosis, migration, and angiogenesis in cancers associated with chronic inflammation. All cytokines mentioned above regulate cellular events in stem cells. These cells could not be targeted by most conventional cancer therapies.

The correlation of extent and grade of inflammation with serum PSA levels in patients with IV prostatitis

OBJECTIVES

The inflammation was categorized more profoundly, using the standardized histopathological classification system for chronic prostatitis of NIH, to determine the influence of prostatic inflammation on serum PSA levels.

METHODS

The study included 120 patients who underwent transperineal ultrasound-guided prostate biopsy. The patients were divided into groups using 3 grades for the extent, the location and the aggressiveness of prostate inflammation. The serum tPSA levels, fPSA levels, %fPSA, and PSAD in each group were compared.

RESULTS

Of 120 patients, 80 with benign prostatic tissue in their biopsy specimens met the inclusion criteria, excluding 40 cases with prostate cancer. The inflammation was present in 46(57.5%) of 80 cases. The extent of inflammation correlated positively with the total PSA level (r = 0.6, P < 0.001), fPSA (r = 0.5, P = 0.001) and PSAD (r = 0.6, P < 0.001). The grade of inflammation correlated positively with the total PSA level (r = 0.5, P < 0.001), fPSA (r = 0.4, P = 0.008) and PSAD (r = 0.7, P < 0.001). A negative correlation was found between the grade of inflammation and %fPSA (r = -0.4, P = 0.013).

CONCLUSIONS

If the elevation of serum PSA is thought to be caused by asymptomatic prostatitis with high aggressiveness score in BPH patients without clinical prostatitis, it might prevent unnecessary repeated biopsies.