Interleukin-17 promotes development of castration-resistant prostate cancer potentially through creating an immunotolerant and pro-angiogenic tumor microenvironment

Matrix metalloproteinases targeting in prostate cancer

Prostate cancer (PCa) is one of the most common tumors affecting men all over the world. PCa has brought a huge health burden to men around the world, especially for elderly men, but its pathogenesis is unclear. In prostate cancer, epigenetic inheritance plays an important role in the development, progression, and metastasis of the disease. An important role in cancer invasion and metastasis is played by matrix metalloproteinases (MMPs), zinc-dependent proteases that break down extracellular matrix. We review two important forms of epigenetic modification and the role of matrix metalloproteinases in tumor regulation, both of which may be of significant value as novel biomarkers for early diagnosis and prognosis monitoring. The author considers that both mechanisms have promising therapeutic applications for therapeutic agent research in prostate cancer, but that efforts should be made to mitigate or eliminate the side effects of drug therapy in order to maximize quality of life of patients. The understanding of epigenetic modification, MMPs, and their inhibitors in the functional regulation of prostate cancer is gradually advancing, it will provide a new technical means for the prevention of prostate cancer, early diagnosis, androgen-independent prostate cancer treatment, and drug research.

Longitudinal plasma proteomic analysis identifies biomarkers and combinational targets for anti-PD1-resistant cancer patients

The response rate of anti-PD1 therapy is limited, and the influence of anti-PD1 therapy on cancer patients is unclear. To address these challenges, we conducted a longitudinal analysis of plasma proteomic changes with anti-PD1 therapy in non-small cell lung cancer (NSCLC), alveolar soft part sarcoma (ASPS), and lymphoma patients. We included 339 plasma samples before and after anti-PD1 therapy from 193 patients with NSCLC, ASPS, or lymphoma. The plasma proteins were detected using data-independent acquisition-mass spectrometry and customable antibody microarrays. Differential proteomic characteristics in responders (R) and non-responders (NR) before and after anti-PD1 therapy were elucidated. A total of 1019 proteins were detected using our in-depth proteomics platform and distributed across 10-12 orders of abundance. By comparing the differential plasma proteome expression between R and NR groups, 50, 206, and 268 proteins were identified in NSCLC, ASPS, and lymphoma patients, respectively. Th17, IL-17, and JAK-STAT signal pathways were identified upregulated in NR group, while cellular senescence and transcriptional misregulation pathways were activated in R group. Longitudinal proteomics analysis revealed the IL-17 signaling pathway was downregulated after treatment. Consistently, many proteins were identified as potential combinatorial therapeutic targets (e.g., IL-17A and CD22). Five noninvasive biomarkers (FLT4, SFTPB, GNPTG, F5, and IL-17A) were further validated in an independent lymphoma cohort (n = 39), and another three noninvasive biomarkers (KIT, CCL3, and TNFSF1) were validated in NSCLC cohort (n = 76). Our results provide molecular insights into the anti-PD1 therapy in cancer patients and identify new therapeutic strategies for anti-PD1-resistant patients.

Physiological roles of human interleukin-17 family

Interleukin-17 s (IL-17s) are well-known proinflammatory cytokines, and their antagonists perform excellently in the treatment of inflammatory skin diseases such as psoriasis. However, their physiological functions have not been given sufficient attention by clinicians. IL-17s can protect the host from extracellular pathogens, maintain epithelial integrity, regulate cognitive processes and modulate adipocyte activity through distinct mechanisms. Here, we present a systematic review concerning the physiological functions of IL-17s. Our goal is not to negate the therapeutic effect of IL-17 antagonists, but to ensure their safe use and reasonably explain the possible adverse events that may occur in their application.

Role of IL-17A and IL-17RA in Prostate Cancer with Lymph Nodes Metastasis: Expression Patterns and Clinical Significance

Prostate cancer (PCa) is the second most frequently diagnosed cancer among men. The use of IL-17A and its receptor IL-17RA as prognostic markers for PCa has shown promising results. We analyzed the clinical data of 77 patients with PCa after radical prostatectomy with lymphadenectomy and lymph node metastasis (LN+). We assessed the expression levels of IL-17A and IL-17RA in cancer cells in prostate and, for the first time, also in LN+. Prostate IL-17A expression positively correlated with BMI (p = 0.028). In LN+, the expression of IL-17A was positively correlated with the percentage of affected lymph nodes (p = 0.006) and EAU risk groups (p = 0.001). Additionally, in the group with high IL-17A expression in LN+, the extracapsular extension (ECE) of the prostate was significantly more frequent (p = 0.033). Also, significant correlations with the level of IL-17RA expression was found-expression was higher in prostate than in LN+ (p = 0.009); in LN+, expression positively correlated with the EAU risk group (p = 0.045), and in the group of high expression in LN+ ECE of lymph nodes was detected significantly more often (p = 0.009). Our findings support the potential role of IL-17A and IL-17RA as PCa markers; however, further studies are needed to determine their roles and potential clinical applications.

Correlation between microvessel maturity and ISUP grades assessed using contrast-enhanced transrectal ultrasonography in prostate cancer

This study aimed to assess the correlation among the peak intensity (PI) values of quantitative parameters, microvessel density (MVD), microvessel maturity, and International Society of Urological Pathology (ISUP) grades in biopsy specimens from prostate cancer (PCa) patients. The study population included PCa patients who underwent targeted and systematic biopsy, without radiation or chemohormonal therapy before biopsy. Contrast-enhanced transrectal ultrasonography (CE-TRUS) was performed in all patients before biopsy. Contrast-enhancement patterns and PI values of quantitative parameters were observed. Tumor tissue samples were immunostained for CD31 expression. MVD, microvessel maturity, and ISUP grades were determined in prostate biopsy specimens. Based on the contrast enhancement patterns of prostate lesions, 16 patients were assigned to a low-enhancement group and 45 to a high-enhancement group. The number of mature vessels, MVD, mature vessel index, and ISUP grades were all higher in the high-enhancement group than in the low-enhancement group (all P < 0.05). The immature vessel index was lower in the high-enhancement group than in the low-enhancement group (P < 0.05). The PI value was positively correlated with the number of mature vessels (r = 0.372). In conclusion, enhancement patterns on CE-TRUS can reflect microvessel maturity in PCa. The PI value was positively correlated with the number of mature vessels.

Novel Histopathological Biomarkers in Prostate Cancer: Implications and Perspectives

Prostate cancer (PCa) is the second most frequently diagnosed cancer in men. Despite the significant progress in cancer diagnosis and treatment over the last few years, the approach to disease detection and therapy still does not include histopathological biomarkers. The dissemination of PCa is strictly related to the creation of a premetastatic niche, which can be detected by altered levels of specific biomarkers. To date, the risk factors for biochemical recurrence include lymph node status, prostate-specific antigen (PSA), PSA density (PSAD), body mass index (BMI), pathological Gleason score, seminal vesicle invasion, extraprostatic extension, and intraductal carcinoma. In the future, biomarkers might represent another prognostic factor, as discussed in many studies. In this review, we focus on histopathological biomarkers (particularly CD169 macrophages, neuropilin-1, cofilin-1, interleukin-17, signal transducer and activator of transcription protein 3 (STAT3), LIM domain kinase 1 (LIMK1), CD15, AMACR, prostate-specific membrane antigen (PSMA), Appl1, Sortilin, Syndecan-1, and p63) and their potential application in decision making regarding the prognosis and treatment of PCa patients. We refer to studies that found a correlation between the levels of biomarkers and tumor characteristics as well as clinical outcomes. We also hypothesize about the potential use of histopathological markers as a target for novel immunotherapeutic drugs or targeted radionuclide therapy, which may be used as adjuvant therapy in the future.

A Multigene-Panel Study Identifies Single Nucleotide Polymorphisms Associated with Prostate Cancer Risk

The immune system plays a critical role in modulating cancer development and progression. Polymorphisms in key genes involved in immune responses are known to affect susceptibility to cancer. Here, we analyzed 35 genes to evaluate the association between variants of genes involved in immune responses and prostate cancer risk. Thirty-five genes were analyzed in 47 patients with prostate cancer and 43 healthy controls using next-generation sequencing. Allelic and genotype frequencies were calculated in both cohorts, and a generalized linear mixed model was applied to test the relationship between prostate cancer risk and nucleotide substitution. Odds ratios were calculated to describe the association between each single nucleotide polymorphism (SNP) and prostate cancer risk. Significant changes in allelic and genotypic distributions were observed for IL4R, IL12RB1, IL12RB2, IL6, TMPRSS2, and ACE2. Furthermore, a generalized linear mixed model identified statistically significant associations between prostate cancer risk and SNPs in IL12RB2, IL13, IL17A, IL4R, MAPT, and TFNRS1B. Finally, a statistically significant association was observed between IL2RA and TNFRSF1B and Gleason scores, and between SLC11A1, TNFRSF1B and PSA values. We identified SNPs in inflammation and two prostate cancer-associated genes. Our results provide new insights into the immunogenetic landscape of prostate cancer and the impact that SNPs on immune genes may have on affecting the susceptibility to prostate cancer.

Immunoproteasome inhibition prevents progression of castration-resistant prostate cancer

BACKGROUND

Castration-resistant prostate cancer (CRPC) is refractory to hormone treatment. This study aims to explore the effect and underlying mechanisms of immunoproteasome inhibition, a novel immunotherapy, on the progression of CRPC.

METHODS

The immunoproteasome subunit LMP7 was silenced by using gene knockout or inhibited by the epoxyketone inhibitor ONX 0914 in a mouse CRPC tumour graft model and in interferon-γ-pretreated human CRPC cell lines in vitro.

RESULTS

CRPC tissues reveal a significant "tumour-elicited" Th17-type inflammatory response which induces immunoproteasome subunit expression. LMP7 deficiency in host mice or in CRPC tumour grafts had no effect on the "tumour-elicited" Th17-type inflammatory response and tumour progression. However, the selective LMP7 inhibitor ONX 0914 strongly suppressed the "tumour-elicited" Th17-type inflammatory response and CRPC tumour progression. Treatment of wild-type mice receiving LMP7-deficient CRPC tumour grafts with ONX 0914 further suggested that immunoproteasome inhibition prevents CRPC progression through suppressing IL-17-induced angiogenesis and epithelial-mesenchymal transition via inactivation of COX-2/VEGF-A signalling and β-catenin/Snail signalling. Treatment of LMP7-deficient mice receiving wild-type CRPC tumour grafts with ONX 0914 and inhibition of LMP7 in PC3 and 22Rv.1 cells with ONX 0914 showed that immunoproteasome inhibition also prevents CRPC progression through inducing CRPC cell apoptosis via activation of the unfolded protein response.

CONCLUSIONS

We define a critical role of the immunoproteasome in CRPC and propose immunoproteasome inhibition as a promising therapeutic approach to suppress CRPC progression.

IL-17A promotes Helicobacter pylori-induced gastric carcinogenesis via interactions with IL-17RC

BACKGROUND

Gastric cancer (GC) is a common malignancy worldwide, with a major attribution to Helicobacter pylori. Interleukin (IL)-17A has been reported to be up-regulated in serum and tumor of GC patients, but the precise mechanisms underlying its involvement in gastric tumorigenesis are yet to be established. Here, we investigated the roles of IL-17A in the pathogenesis of H. pylori-induced GC.

METHODS

GC was induced in IL-17A knockout (KO) and wild-type (WT) mice via N-methyl-N-nitrosourea (MNU) treatment and H. pylori infection. At 50 weeks after treatment, gastric tissues were examined by histopathology, immunohistochemistry, and immunoblot analyses. In vitro experiments on the human GC cell lines were additionally performed to elucidate the underlying mechanisms.

RESULTS

Deletion of IL-17A suppressed MNU and H. pylori-induced gastric tumor development accompanied by a decrease in gastric epithelial cell growth, oxidative stress, and expression of gastric epithelial stem cells markers. In AGS cells, recombinant human IL-17A (rhIL-17A) inhibited apoptosis and G1/S phase transition arrest while promoting reactive oxygen species production, sphere formation ability of cancer stem cells (CSC), and expression of stemness-related genes. In addition, rhIL-17A induced expression of IL-17RC, leading to NF-κB activation and increased NADPH oxidase 1 (NOX1) levels. Inhibition of NOX1 with GKT136901 attenuated rhIL-17A-mediated elevation of GC cell growth, ROS generation, and CSC stemness. Clinically, IL-17RC expressions were significantly upregulated in human GC compared with normal gastric tissues.

CONCLUSION

Our results suggest that IL-17A promotes gastric carcinogenesis, in part, by regulating IL-17RC/NF-κB/NOX1 pathway, supporting its potential as a target in human GC therapy.

Suppression of prostate cancer and amelioration of the immunosuppressive tumor microenvironment through selective immunoproteasome inhibition

New treatment options to battle hormone-refractory prostate carcinoma (PC) are a pressing medical need. Chronic inflammation has been implicated in PC etiology. The pro-inflammatory cytokines IL-6, IL-23 and IL-17 are key mediators to promote growth of PC. Here, we evaluate the potential of immunoproteasome inhibition for anti-inflammatory and direct anti-tumorigenic therapy of PC. The anti-tumor effect of immunoproteasome inhibitor ONX 0914 was tested in mouse and human PC cells and the in vivo therapeutic efficacy of immunoproteasome inhibition was analyzed in transgenic adenocarcinoma of the mouse prostate (TRAMP) mice in preventive and therapeutic settings and in castration-resistant (CR)PC after castration. Inhibition of the immunoproteasome subunit LMP7 induced apoptotic cell death in PC cell lines. In TRAMP mice, ONX 0914-treatment resulted in significant inhibition of PC growth with a decreased frequency of malignant prostatic lesions and inhibition of metastasis formation. The number of immunosuppressive myeloid cells in PC was greatly reduced in response to ONX 0914. Thus, immunoproteasome inhibition shows remarkable efficacy against PC progression in vivo and impedes tumor recurrence in CRPC-TRAMP mice by blocking the immunosuppressive inflammatory response in the tumor microenvironment. In conclusion, we show that the immunoproteasome is a promising drug target for the treatment of PC.

Risk of colon cancer-related death in people who had cancer in the past

BACKGROUND

The rate of second primary malignancies (SPM) is gradually increasing. Yet, the risk of death from primary cancer vs. SPM is still not well understood. In this study, we investigated the survival of patients with colorectal cancer (as SPM) who had cancer in the past (prior cancer) and the risk factors of SPM death in this population.

MATERIALS AND METHODS

Based on the Surveillance, Epidemiology, and End Results (SEER) database, we identified 1866 colon cancer patients with prior cancer in our main cohort and 43,959 colon cancer patients, including 37,440 patients with colon cancer as only malignancy and 6519 patients with colon cancer as subsequent colon cancer (SCC), in a second cohort and 3429 colon cancer patients, including 2371 patients with prior colon cancer (PCC) and 1058 patients with colon cancer as SPM, in a third cohort. After propensity score matching, 6519 pairs of subjects were identified in second cohort.

RESULTS

Patients with prior prostate and breast cancer had a higher risk of developing colon cancer compared to those with gastrointestinal cancer. Also, colon cancer patients with different prior cancer had different survival rates. Furthermore, except for prior lung cancer (52.78 vs. 25.93%), most subjects died due to colon cancer complications. The ratio of colon cancer deaths to prior cancer deaths in patients with a low stage and high stage was 1.51 and 6.64, respectively. In addition, colon cancer-specific survival (CSS) and OS rates were significantly lower in subjects with colon cancer as the SPM than in those with PCC. Also, compared with PCC, SPM was associated with OS and CSS with HR 1.59 (95 CI 1.43-1.78) and HR 2.00 (95% CI 1.70-2.36). Furthermore, compared with only colon cancer, SCC was associated with OS and CSS with HR 1.23 (95 CI 1.17-1.29) and HR 1.13 (95% CI 1.06-1.21).

CONCLUSIONS

Prior cancer was found to have an adverse impact on OS in patients with colon cancer (secondary cancer), most of whom died due to colon cancer as secondary cancer itself rather than prior cancer. Early detection and treatment strategies should be investigated in this population.

Pan-Cancer Analyses of the Tumor Microenvironment Reveal That Ubiquitin-Conjugating Enzyme E2C Might Be a Potential Immunotherapy Target

Increasing evidence indicated that the tumor microenvironment (TME) played a crucial role in cancer initiation and progression. Ubiquitin-conjugating enzyme E2C (UBE2C) was differentially expressed in many cancer types. However, the immunological and prognostic roles of UBE2C were unclear. Differentially expressed genes (DEGs) of 29 cancer types were downloaded from GEPIA2 and 4 cancer types failed to download owing to no DEGs. Furthermore, the gene expression profiles, mutation data, and survival data of 33 cancer types were obtained from UCSC Xena. Clinical stage relevance, tumor mutational burden (TMB), TME relevance analysis, and gene set enrichment analysis (GSEA) of DEGs in 33 cancer types were performed. And DEGs were identified in oral squamous cell carcinoma (OSCC) by biological experiments. Previous studies indicated that UBE2C was related to the prognosis of many cancers. In our study, the higher UBE2C expression level meant a terminal clinical stage in 8 cancer types and the expression level of UBE2C was related to TMB in 20 cancer types. In addition, both immune relevance analysis and GSEA showed that UBE2C might participate in immune response in many cancers. Furthermore, the UBE2C mRNA level and protein level were all identified as upregulated in OSCC cell lines and tissues. UBE2C was differentially expressed in many cancer types and related to the pathogenesis and TME of many cancers, which might be a potential diagnostic and therapeutic biomarker.

A Novel Controlled PTEN-Knockout Mouse Model for Prostate Cancer Study

Prostate cancer (PCa) is associated with advanced age, but how age contributes to prostate carcinogenesis remains unknown. The prostate-specific Pten conditional knockout mouse model closely imitates human PCa initiation and progression. To better understand how age impacts PCa in an experimental model, we have generated a spatially and temporally controlled Pten-null PCa murine model at different ages (aged vs. non-aged) of adult mice. Here, we present a protocol to inject the Cre-expressing adenovirus with luciferin tag, intraductally, into the prostate anterior lobes of Pten-floxed mice; Pten-loss will be triggered post-Cre expression at different ages. In vivo imaging of luciferin signal following viral infection confirmed successful delivery of the virus and Cre activity. Immunohistochemical staining confirmed prostate epithelial-specific expression of Cre recombinase and the loss of Pten and activation of P-Akt, P-S6, and P-4E-BP1. The Cre-expression, Pten ablation, and activated PI3K/AKT/mTOR pathways were limited to the prostate epithelium. All mice developed prostatic epithelial hyperplasia within 4 weeks after Pten ablation and prostatic intraepithelial neoplasia (PIN) within 8 weeks post-Pten ablation. Some PINs had progressed to invasive adenocarcinoma at 8-16 weeks post-Pten ablation. Aged mice exhibited significantly accelerated PI3K/AKT/mTOR signaling and increased PCa onset and progression compared to young mice. The viral infection success rate is ∼80%. This model will be beneficial for investigations of cancer-related to aging.

Rosmarinic acid inhibits migration, invasion, and p38/AP-1 signaling via miR-1225-5p in colorectal cancer cells

Elucidating the molecular mechanism of the migration and invasion is critical for identifying novel therapeutic targets and may significantly improve the prognosis of colorectal cancer. Emerging evidence suggests an involvement of dysregulated microRNAs in the process of tumorigenesis. Here, we show that miR-1225-5p prevents migration and invasion of colorectal cancer cells. Overexpression of miR-1225-5p significantly decreases the expression of Matrix Metalloproteases (MMPs)-1, 3, and 9. Knockdown of miR-1225-5p elevates ROS level via regulating Keap1/Nrf2 pathway. Furthermore, miR-1225-5p attenuates IL-17A-induced p38/AP-1-signaling pathway by suppressing IL-17RA expression. We also examined the biological effects of Rosmarinic acid (RA) on metastatic colorectal cancer cells. RA inhibited EMT via the p38/AP-1 signaling, and miR-1225-5p is essential for RA-mediated anti-metastatic effects.

Obesity-Modified CD4+ T-Cells Promote an Epithelial-Mesenchymal Transition Phenotype in Prostate Cancer Cells

Obesity is associated with low-grade chronic inflammation, and metabolic dysregulation. Evidence shows that chronic inflammation inhibits protective immunity mediated by CD4+ T cells. Additionally, obesity-induced inflammation affects prostate cancer progression. However, the effect of obesity on CD4+ T-cell- response to prostate cancer is not well understood. To investigate whether obesity induces changes in CD4+ T cell cytokine profile, cytokine expression was measured in splenic CD4+ T-cells from 10-week-old male C57Bl/6 mice exposed to conditioned media (CM) from macrophages grown in sera from obese subjects. Additionally, expression levels of key regulators of Epithelial-Mesenchymal Transition (EMT) were measure in prostate cancer epithelial cells exposed to conditioned media from obesity-modified T-cells. Cell migration and invasion was measured in prostate cancer epithelial cells exposed to CM from obesity-modified CD4+ T-cells. Obesity suppressed the expression of IFNγ and IL-2 in CD4+ T-cells but up-regulated the expression of IL-6. Prostate epithelial cancer cells exposed to conditioned media from obesity-modified T cell increased the expression of EMT markers and showed a higher invasive and migratory capacity.

IL-12 Family Cytokines in Cancer and Immunotherapy

The IL-12 family cytokines are a group of unique heterodimeric cytokines that include IL-12, IL-23, IL-27, IL-35 and, most recently, IL-39. Recent studies have solidified the importance of IL-12 cytokines in shaping innate and adaptive immune responses in cancer and identified multipronged roles for distinct IL-12 family members, ranging from effector to regulatory immune functions. These cytokines could serve as promising candidates for the development of immunomodulatory therapeutic approaches. Overall, IL-12 can be considered an effector cytokine and has been found to engage anti-tumor immunity by activating the effector Th1 response, which is required for the activation of cytotoxic T and NK cells and tumor clearance. IL-23 and IL-27 play dual roles in tumor immunity, as they can both activate effector immune responses and promote tumor growth by favoring immune suppression. IL-35 is a potent regulatory cytokine and plays a largely pro-tumorigenic role by inhibiting effector T cells. In this review, we summarize the recent findings on IL-12 family cytokines in the control of tumor growth with an emphasis primarily on immune regulation. We underscore the clinical implications for the use of these cytokines either in the setting of monotherapy or in combination with other conventional therapies for the more effective treatment of malignancies.

Cellular and Molecular Progression of Prostate Cancer: Models for Basic and Preclinical Research

Simple Summary

The molecular progression of prostate cancer is complex and elusive. Biological research relies heavily on in vitro and in vivo models that can be used to examine gene functions and responses to the external agents in laboratory and preclinical settings. Over the years, several models have been developed and found to be very helpful in understanding the biology of prostate cancer. Here we describe these models in the context of available information on the cellular and molecular progression of prostate cancer to suggest their potential utility in basic and preclinical prostate cancer research. The information discussed herein should serve as a hands-on resource for scholars engaged in prostate cancer research or to those who are making a transition to explore the complex biology of prostate cancer.

Abstract

We have witnessed noteworthy progress in our understanding of prostate cancer over the past decades. This basic knowledge has been translated into efficient diagnostic and treatment approaches leading to the improvement in patient survival. However, the molecular pathogenesis of prostate cancer appears to be complex, and histological findings often do not provide an accurate assessment of disease aggressiveness and future course. Moreover, we also witness tremendous racial disparity in prostate cancer incidence and clinical outcomes necessitating a deeper understanding of molecular and mechanistic bases of prostate cancer. Biological research heavily relies on model systems that can be easily manipulated and tested under a controlled experimental environment. Over the years, several cancer cell lines have been developed representing diverse molecular subtypes of prostate cancer. In addition, several animal models have been developed to demonstrate the etiological molecular basis of the prostate cancer. In recent years, patient-derived xenograft and 3-D culture models have also been created and utilized in preclinical research. This review is an attempt to succinctly discuss existing information on the cellular and molecular progression of prostate cancer. We also discuss available model systems and their tested and potential utility in basic and preclinical prostate cancer research.

CD4+ T helper 17 cell response of aged mice promotes prostate cancer cell migration and invasion

BACKGROUND

Aging is the most important risk factor for prostate cancer (PCa), but how age contributes to PCa is poorly understood. Aging is characterized by low-grade systemic inflammation (i.e., inflammaging) that is often attributed to the progressive activation of immune cells over time, which may play an important role in prostate carcinogenesis. Th17 response is elevated in aging humans and mice, but it remains unknown whether it is increased in prostate tissue or contributes to prostate carcinogenesis during aging. In this study, we aimed to determine the role of age-related Th17 response in PCa cell growth, migration, and invasion.

METHODS

C57BL/6J (B6) mouse was used as an aging animal model and the prostate histopathology during aging was analyzed. Splenic CD4⁺ T cells were isolated from young (16-20 weeks old) and aged (96-104 weeks old) mice, and cultured in the presence of plate-bound anti-CD3/anti-CD28, with or without Th17 differentiation conditions. The cells were collected and used for subsequent flow cytometry or quantitative reverse transcription polymerase chain reaction. The supernatant was collected and used to treat PCa cell lines. The treated PCa cells were analyzed for cell viability, migration, invasion, and nuclear factor kappa B (NF-κB) signaling.

RESULTS

Aged mice had enlarged prostate glands and increased morphological alterations, with not only increased inflammatory cell infiltration but also increased Th17 cytokines in prostate tissue, compared to young mice. Naïve CD4⁺ T cells from aged mice differentiated increased interleukin (IL)-17-expressing cells. CD4⁺ T cells from aged mice spleen had increased Th17 cells, Th17 cytokines and Th17/Treg ratio compared to young mice. Factors secreted from aged CD4⁺ T cells, especially from ex vivo differentiated Th17 cells, not only promoted PCa cell viability, migration, and invasion but also activated the NF-κB signaling in PCa cells compared to young mice.

CONCLUSIONS

These results indicate that age-related CD4⁺ T cells, especially Th17 cells-secreted factors have the potential to contribute to prostate carcinogenesis. Our work could prompt further research using autochthonous PCa mouse models at different ages to elucidate the functional role of Th17 response in prostate carcinogenesis during aging.

Immune landscape of human prostate cancer: immune evasion mechanisms and biomarkers for personalized immunotherapy

BACKGROUND

Despite recent advances in cancer immunotherapy, the efficacy of these therapies for the treatment of human prostate cancer patients is low due to the complex immune evasion mechanisms (IEMs) of prostate cancer and the lack of predictive biomarkers for patient responses.

METHODS

To understand the IEMs in prostate cancer and apply such understanding to the design of personalized immunotherapies, we analyzed the RNA-seq data for prostate adenocarcinoma from The Cancer Genome Atlas (TCGA) using a combination of biclustering, differential expression analysis, immune cell typing, and machine learning methods.

RESULTS

The integrative analysis identified eight clusters with different IEM combinations and predictive biomarkers for each immune evasion cluster. Prostate tumors employ different combinations of IEMs. The majority of prostate cancer patients were identified with immunological ignorance (89.8%), upregulated cytotoxic T lymphocyte-associated protein 4 (CTLA4) (58.8%), and upregulated decoy receptor 3 (DcR3) (51.6%). Among patients with immunologic ignorance, 41.4% displayed upregulated DcR3 expression, 43.26% had upregulated CTLA4, and 11.4% had a combination of all three mechanisms. Since upregulated programmed cell death 1 (PD-1) and/or CTLA4 often co-occur with other IEMs, these results provide a plausible explanation for the failure of immune checkpoint inhibitor monotherapy for prostate cancer.

CONCLUSION

These findings indicate that human prostate cancer specimens are mostly immunologically cold tumors that do not respond well to mono-immunotherapy. With such identified biomarkers, more precise treatment strategies can be developed to improve therapeutic efficacy through a greater understanding of a patient's immune evasion mechanisms.

Expression Levels of IL-17A, IL-17F, IL-17RA, and IL-17RC in Prostate Cancer with Taking into Account the Histological Grade according to Gleason Scale in Comparison to Benign Prostatic Hyperplasia: In Search of New Therapeutic Options

Prostate cancer (PCa) is the second most commonly diagnosed malignant tumor and the fifth leading cause of cancer death in men in the world. The most common types of tumors are adenocarcinomas. Prostate cancer is a slow-growing cancer. The incidence increases with age. Evaluation of proinflammatory factors such as IL-17A, IL-17F, IL-17RA, and IL-17RC expression makes it possible to assess the impact of inflammatory process on progression of PCa. The aim of the study was to retrospectively assess the histological material of PCa divided into few groups using the Gleason score. Studies were carried out on archival tissue material in the form of paraffin blocks of 40 men with PCa after radical prostatectomy. The control group was composed of 10 men with benign prostatic hyperplasia (BPH). The material was obtained by the transurethral resection of the prostate (TURP). Immunohistochemistry was performed on prepared material using specific primary antibodies against IL-17A, IL-17F, IL-17RA, and IL-17RC. Expression of the antibody to be examined using light microscopy and the Remmele-Stegner score (IRS) in cancer staining was then evaluated. Expression of IL-17 RA was not shown in a group of patients with PCa and in the control group. In the group of patients with Gleason score 8 and 9 PCa, the expression of IL-17A was higher compared to that of IL-17F. In addition, in PCa with an increased grade of Gleason scale, a decrease in the expression of the study inflammatory parameters was found. The inflammatory process has an impact on PCa. A study on IL-17 may become a starting point for further research on an attempt to use, for example, immunotherapy in PCa.

Genetic alterations of interleukin-17 and related genes in human prostate cancer

Interleukin-17 (IL-17) has been shown to promote development of hormone-naïve prostate cancer (HNPC) and castration-resistant prostate cancer (CRPC) as well as lymph node metastasis in mouse models. Gene alterations of IL-17 family of cytokines and their downstream genes in human prostate cancer have not been investigated. We studied 7 datasets archived in cBioPortal and queried gene alterations in a total of 1303 cases of human prostate cancers. 35 genes were examined, including IL-17 family of cytokines and receptors, IL-17-downstream genes, and genes related to IL-17-downstream genes. We found that 34/35 (97%) genes had significantly more alterations in metastatic prostate cancer (with alteration rates ranging from 3.42% to 13.01%) than primary prostate cancer (with alteration rates ranging from 0.40% to 2.96%). 15/35 (43%) genes had significantly more alterations in primary CRPC than primary HNPC. 34/35 (97%) genes had significantly more alterations in metastatic CRPC than primary HNPC. Only three genes (S100A7, S100A8, and S100A9) had significantly more alterations in metastatic CRPC than primary CRPC. The gene alterations were mostly gene amplifications (97%), while gene deep deletions, missense mutations, and truncating mutations were very rare. 7/35 (20%) genes had significantly more alterations in primary neuroendocrine prostate cancer (NEPC) than primary adenocarcinoma (AC). 23/35 (66%) genes had significantly more alterations in metastatic NEPC than metastatic AC. Only three genes (S100A7, S100A8, and S100A9) had significantly more alterations in metastatic NEPC than metastatic AC with neuroendocrine features. Most of the gene alterations in metastatic NEPC were gene amplifications (80%), while gene deep deletions, missense mutations, and truncating mutations were very rare. Our findings suggest that gene amplifications of IL-17 and related genes are more frequently found in metastatic CRPC and NEPC than primary hormone-naïve prostate adenocarcinomas, implying that IL-17 and related genes may play important roles in the progression from HNPC to CRPC and from primary location to metastasis as well as in development of metastatic NEPC.

Th17 cells promote tumor growth in an immunocompetent orthotopic mouse model of prostate cancer

Interleukin-17 (IL-17) has been demonstrated to promote development of a variety of cancers including prostate cancer in genetically modified mouse models. IL-17 is the main product secreted by T helper 17 (Th17) cells. A recent study has shown that Th17 cells and related genes are upregulated in human prostate cancers. However, there is no direct experimental evidence to demonstrate Th17's role in prostate cancer. In the present study, we co-implanted mouse prostate cancer MPC3-luc cells with Th17-polarized mouse splenocytes in the prostate of immunocompetent C57BL/6J male mice. We found that Th17-polarized splenocytes promoted orthotopic allograft prostate tumor growth compared to the control splenocytes. The numbers of IL-17-positive lymphocytes and macrophages were higher in the prostate tumors grown from co-implantation of MPC3-luc cells and Th17-polarized splenocytes, compared to the prostate tumors grown from co-implantation of MPC3-luc cells and control splenocytes. Our findings provide the first direct experimental evidence that Th17 cells may promote prostate cancer growth.

Main Inflammatory Cells and Potentials of Anti-Inflammatory Agents in Prostate Cancer

Prostate cancer is the most common type of cancer and the leading cause of cancer deaths among men in many countries. Preventing progression is a major concern for prostate cancer patients on active surveillance, patients with recurrence after radical therapies, and patients who acquired resistance to systemic therapies. Inflammation, which is induced by various factors such as infection, microbiome, obesity, and a high-fat diet, is the major etiology in the development of prostate cancer. Inflammatory cells play important roles in tumor progression. Various immune cells including tumor-associated neutrophils, tumor-infiltrating macrophages, myeloid-derived suppressor cells, and mast cells promote prostate cancer via various intercellular signaling. Further basic studies examining the relationship between the inflammatory process and prostate cancer progression are warranted. Interventions by medications and diets to control systemic and/or local inflammation might be effective therapies for prostate cancer progression. Epidemiological investigations and basic research using human immune cells or mouse models have revealed that non-steroidal anti-inflammatory drugs, metformin, statins, soy isoflavones, and other diets are potential interventions for preventing progression of prostate cancer by suppressing inflammation. It is essential to evaluate appropriate indications and doses of each drug and diet.

Low Expression of miR-424-3p is Highly Correlated with Clinical Failure in Prostate Cancer

Prostate cancer (PC) is a highly heterogenous disease and one of the leading causes of mortality in developed countries. Recently, studies have shown that expression of immune checkpoint proteins are directly or indirectly repressed by microRNAs (miRs) in many types of cancers. The great advantages of using miRs based therapy is the capacity of these short transcripts to target multiple molecules for the same- or different pathways with synergistic immune inhibition effects. miR-424 has previously been described as a biomarker of poor prognosis in different types of cancers. miR-424 is also found to target both the CTLA-4/CD80- and PD-1/PD-L1 axis. In the present study, the clinical significance of miR-424-3p expression in PC tissue was evaluated. Naïve radical prostatectomy specimens from 535 patients was used for tissue microarray construction. In situ hybridization was used to evaluate the expression of miR-424-3p and immunohistochemistry was used for CTLA-4 protein detection. In univariate- and multivariate analyses, low expression of miR-424-3p was significant associated with clinical failure-free survival, (p = 0.004) and p = 0.018 (HR:0.44, CI95% 0.22-0.87). Low expression of miR-424-3p also associated strongly with aggressive phenotype of PC. This highlight the importance of miR-424-3p as potential target for therapeutic treatment in prostate cancer.

Interleukin-17 Promotes Migration and Invasion of Human Cancer Cells Through Upregulation of MTA1 Expression

Interleukin-17 (IL-17) has been shown to promote development of prostate, colon, skin, lung, breast, and pancreatic cancer. The purpose of this study was to determine if IL-17 regulates MTA1 expression and its biological consequences. Human cervical cancer HeLa and human prostate cancer DU-145 cell lines were used to test if IL-17 regulates metastasis associated 1 (MTA1) mRNA and protein expression using quantitative reverse transcription-polymerase chain reaction and Western blot analysis, respectively. Cell migration and invasion were studied using wound healing assays and invasion chamber assays. Thirty-four human cervical tissues were stained for IL-17 and MTA1 using immunohistochemical staining. We found that IL-17 increased MTA1 mRNA and protein expression in both cell lines. Cell migration was accelerated by IL-17, which was abolished by knockdown of MTA1 expression with small interference RNA (siRNA). Further, cell invasion was enhanced by IL-17, which was eliminated by MTA1 knockdown. Human cervical intra-epithelial neoplasia (CIN) and cervical cancer tissues had increased number of IL-17-positive cells and MTA1 expression compared to normal cervical tissues. The number of IL-17-positive cells was positively correlated with MTA1 expression. These findings demonstrate that IL-17 upregulates MTA1 mRNA and protein expression to promote HeLa and DU-145 cell migration and invasion.

Tumor-associated neutrophils induce EMT by IL-17a to promote migration and invasion in gastric cancer cells

PURPOSE

Epithelial to mesenchymal transition (EMT) can contribute to gastric cancer (GC) progression and recurrence following therapy. Tumor-associated neutrophils (TANs) are associated with poor outcomes in a variety of cancers. However, it is not clear whether TANs interact with the EMT process during GC development.

METHODS

Immunohistochemistry was performed to examine the distribution and levels of CD66 + neutrophils in samples from 327 patients with GC. CD66b + TANs were isolated either directly from GC cell suspensions or were conditioned from healthy donor peripheral blood polymorphonuclear neutrophils (PMNs) stimulated with tumor tissue culture supernatants (TTCS) and placed into co-culture with MKN45 or MKN74 cells, after which migration, invasion and EMT were measured. Interleukin-17a (IL-17a) was blocked with a polyclonal antibody, and the STAT3 pathway was blocked with the specific inhibitor AG490.

RESULTS

Neutrophils were widely distributed in gastric tissues of patients with GC and were enriched predominantly at the invasion margin. Neutrophil levels at the invasion margin were an independent predictor of poor disease-free survival (DFS) and disease-specific survival (DSS). IL-17a + neutrophils constituted a large portion of IL-17a-producing cells in GC, and IL-17a was produced at the highest levels in co-culture compared with that in TANs not undergoing co-culture. TANs enhanced the migration, invasion and EMT of GC cells through the secretion of IL-17a, which activated the Janus kinase 2/signal transducers and activators of transcription (JAK2/STAT3) pathway in GC cells, while deprivation of IL-17a using a neutralizing antibody or inhibition of the JAK2/STAT3 pathway with AG490 markedly reversed these TAN-induced phenotypes in GC cells induced by TANs.

CONCLUSIONS

Neutrophils correlate with tumor stage and predict poor prognosis in GC. TANs produce IL-17a, which promotes EMT of GC cells through JAK2/STAT3 signalling. Blockade of IL-17a signalling with a neutralizing antibody inhibits TAN-stimulated activity in GC cells. Therefore, IL-17a-targeted therapy might be used to treat patients with GC.

Interleukin-17 promotes metastasis in an immunocompetent orthotopic mouse model of prostate cancer

Metastasis of prostate cancer causes substantial morbidity and mortality. The role of chronic inflammatory factors in promoting the development of prostate cancer metastasis remains unexamined due to a lack of immunocompetent animal models. Here we report an orthotopic mouse allograft model of prostate cancer that was used to assess interleukin-17's role in prostate cancer metastasis. A luciferase gene was stably introduced into a mouse prostate cancer cell line MPC3, named as MPC3-luc. MPC3-luc cells were mixed with Matrigel™ and inoculated into C57BL/6 mouse prostates, with recombinant mouse interleukin-17 (IL-17) (treatment group) or without IL-17 (control group). Bioluminescent imaging was used to track the growth and metastasis of prostate cancer metastasis. Immunohistochemistry was performed to confirm metastasis. Mice in the IL-17 treatment group had significantly higher incidence of metastasis than mice in the control group. However, there was no detectable difference in primary prostate tumor growth. Metastases were confirmed as originating from prostate cancer through staining for luciferase protein expression. Our findings suggest that interleukin-17 promotes prostate cancer metastasis in an orthotopic mouse allograft model.

The role of prostatic inflammation in the development and progression of benign and malignant diseases

PURPOSE OF REVIEW

To evaluate the role of prostatic inflammation in the development and progression of benign and malignant prostatic diseases.

RECENT FINDINGS

Preclinical studies demonstrate that the activation of a chronic inflammatory prostatic response plays an important role in the pathogenesis and progression of benign prostatic hyperplasia (BPH) and prostate cancer (PCa). Approximately 40-70% of patients with BPH-related lower urinary tract symptoms harbour chronic inflammation at pathologic evaluation. These individuals should be considered at increased risk of symptom progression and acute urinary retention. Although currently available drugs approved for the treatment of BPH do not have an anti-inflammatory activity, the development of novel molecules that target the inflammatory pathway represents a promising area in the pharmacological treatment of BPH. Preclinical evidences support a potential role of chronic prostatic inflammation in the malignant transformation of prostatic cells. However, clinical investigations on the association between prostatic inflammation and the risk of PCa report conflicting results.

SUMMARY

Men with BPH-related lower urinary tract symptoms and chronic prostatic inflammation should be considered at increased risk of symptom progression and acute urinary retention during follow-up. Although preclinical studies provide a biological rationale for the relationship between inflammation and the risk of PCa, clinical investigations report conflicting results and the direct relationship between inflammation and malignant transformation in the human prostate is still debated.

Increased interleukin-17A levels promote rituximab resistance by suppressing p53 expression and predict an unfavorable prognosis in patients with diffuse large B cell lymphoma

Rituximab resistance has become increasingly common in patients with diffuse large B cell lymphoma (DLBCL). However, the mechanisms involved remain unclear. In this study, we aimed to examine the effect of rituximab on interleukin (IL)-17A and to investigate the role of IL-17A in rituximab resistance and its prognostic value in patients with DLBCL. Our retrospective analysis revealed that rituximab increased IL-6 expression levels in patients with DLBCL, and the increased IL-6 levels in turn induced the differentiation of Th17 and IL-17⁺Foxp3⁺ Treg cells, which secreted IL-17A both in vivo and in vitro. We then examined the effects of IL-17A on the apoptosis and proliferation of, and p53 expression in DLBCL cells, and found that IL-17A prevented rituximab-induced apoptosis and promoted the proliferation of DLBCL cells by suppressing p53 expression in vitro. The survival data of 73 patients with DLBCL suggested that high peripheral blood levels of IL-17A predicted an unfavorable survival. On the whole, our data indicate that rituximab promotes Th17 and IL-17⁺Foxp3⁺ Treg cells to secrete IL-17A, which in turn promotes rituximab resistance, partially by suppressing p53 expression and inhibiting rituximab-induced DLBCL cell apoptosis. IL-17A may thus prove to be a useful prognostic marker in patients with DLBCL.

Distinct subtypes of genomic PTEN deletion size influence the landscape of aneuploidy and outcome in prostate cancer

Background

Inactivation of the PTEN tumor suppressor gene by deletion occurs in 20-30% of prostate cancer tumors and loss strongly correlates with a worse outcome. PTEN loss of function not only leads to activation of the PI3K/AKT pathway, but is also thought to affect genome stability and increase levels of tumor aneuploidy. We performed an in silico integrative genomic and transcriptomic analysis of 491 TCGA prostate cancer tumors. These data were used to map the genomic sizes of PTEN gene deletions and to characterize levels of instability and patterns of aneuploidy acquisition.

Results

PTEN homozygous deletions had a significant increase in aneuploidy compared to PTEN tumors without an apparent deletion, and hemizygous deletions showed an intermediate aneuploidy profile. A supervised clustering of somatic copy number alterations (SCNA) demonstrated that the size of PTEN deletions was not random, but comprised five distinct subtypes: (1) "Small Interstitial" (70 bp-789Kb); (2) "Large Interstitial" (1-7 MB); (3) "Large Proximal" (3-65 MB); (4) "Large Terminal" (8-64 MB), and (5) "Extensive" (71-132 MB). Many of the deleted fragments in each subtype were flanked by low copy repetitive (LCR) sequences. SCNAs such as gain at 3q21.1-3q29 and deletions at 8p, RB1, TP53 and TMPRSS2-ERG were variably present in all subtypes. Other SCNAs appeared to be recurrent in some deletion subtypes, but absent from others. To determine how the aneuploidy influenced global levels of gene expression, we performed a comparative transcriptome analysis. One deletion subtype (Large Interstitial) was characterized by gene expression changes associated with angiogenesis and cell adhesion, structure, and metabolism. Logistic regression demonstrated that this deletion subtype was associated with a high Gleason score (HR = 2.386; 95% C.I. 1.245-4.572), extraprostatic extension (HR = 2.423, 95% C.I. 1.157-5.075), and metastasis (HR = 7.135; 95% C.I. 1.540-33.044). Univariate and multivariate Cox Regression showed that presence of this deletion subtype was also strongly predictive of disease recurrence.

Conclusions

Our findings indicate that genomic deletions of PTEN fall into five different size distributions, with breakpoints that often occur close LCR regions, and that each subtype is associated with a characteristic aneuploidy signature. The Large Interstitial deletion had a distinct gene expression signature that was related to cancer progression and was also predictive of a worse prognosis.

Hyperinsulinemia enhances interleukin-17-induced inflammation to promote prostate cancer development in obese mice through inhibiting glycogen synthase kinase 3-mediated phosphorylation and degradation of interleukin-17 receptor

Interleukin-17 (IL-17) plays important roles in inflammation, autoimmune diseases, and some cancers. Obese people are in a chronic inflammatory state with increased serum levels of IL-17, insulin, and insulin-like growth factor 1 (IGF1). How these factors contribute to the chronic inflammatory status that promotes development of aggressive prostate cancer in obese men is largely unknown. We found that, in obese mice, hyperinsulinemia enhanced IL-17-induced expression of downstream proinflammatory genes with increased levels of IL-17 receptor A (IL-17RA), resulting in development of more invasive prostate cancer. Glycogen synthase kinase 3 (GSK3) constitutively bound to and phosphorylated IL-17RA at T780, leading to ubiquitination and proteasome-mediated degradation of IL-17RA, thus inhibiting IL-17-mediated inflammation. IL-17RA phosphorylation was reduced, while the IL-17RA levels were increased in the proliferative human prostate cancer cells compared to the normal cells. Insulin and IGF1 enhanced IL-17-induced inflammatory responses through suppressing GSK3, which was shown in the cultured cell lines in vitro and obese mouse models of prostate cancer in vivo. These findings reveal a mechanism underlying the intensified inflammation in obesity and obesity-associated development of aggressive prostate cancer, suggesting that targeting GSK3 may be a potential therapeutic approach to suppress IL-17-mediated inflammation in the prevention and treatment of prostate cancer, particularly in obese men.

Organoid culture of human prostate cancer cell lines LNCaP and C4-2B

Organoids mimic the architecture and functions of a small organ. Organoid culture technique has been rapidly accepted by all research communities during the past decade to study stem cells, organ development and function, and patient-specific diseases. A protocol for organoid culture of human and mouse prostate epithelial and cancer tissues has been reported. However, organoid culture of the commonly used human prostate cancer cell lines has yet to be established. We followed the published protocol and performed organoid culture of LNCaP and C4-2B cells in MatrigelTM and organoid culture medium for 14 days. We found that both LNCaP and C4-2B cell lines formed organoids that presented glandular structures. The cells within the organoids were androgen receptor-positive adenocarcinoma cells, but not p63-positive basal cells. The cells in the organoids responded to interleukin-17A treatment differently from the cells in the monolayer culture. The present study suggests that LNCaP and C4-2B cells are able to form organoids under the defined organoid culture conditions.

Targeting Th17-IL-17 Pathway in Prevention of Micro-Invasive Prostate Cancer in a Mouse Model

BACKGROUND

Chronic inflammation has been associated with the development and progression of human cancers including prostate cancer. The exact role of the inflammatory Th17-IL-17 pathway in prostate cancer remains unknown. In this study, we aimed to determine the importance of Th17 cells and IL-17 in a Pten-null prostate cancer mouse model.

METHODS

The Pten-null mice were treated by Th17 inhibitor SR1001 or anti-mouse IL-17 monoclonal antibody from 6 weeks of age up to 12 weeks of age. For SR1001 treatment, the mice were injected intraperitoneally (i.p.) twice a day with vehicle or SR1001, which was dissolved in a dimethylsulfoxide (DMSO) solution. All mice were euthanized for necropsy at 12 weeks of age. For IL-17 antibody treatment, the mice were injected intravenously (i.v.) once every two weeks with control IgG or rat anti-mouse IL-17 monoclonal antibody, which was dissolved in PBS. The injection time points were at 6, 8, and 10 weeks old. All mice were analyzed for the prostate phenotypes at 12 weeks of age.

RESULTS

We found that either SR1001 or anti-IL-17 antibody treatment decreased the formation of micro-invasive prostate cancer in Pten-null mice. The SR1001 or anti-IL-17 antibody treated mouse prostates had reduced proliferation, increased apoptosis, and reduced angiogenesis, as well as reduced inflammatory cell infiltration. By assessing the epithelial-to-mesenchymal transition (EMT) markers, we found that SR1001 or anti-IL-17 antibody treated prostate tissues had weaker EMT phenotype compared to the control treated prostates.

CONCLUSIONS

These results demonstrated that Th17-IL-17 pathway plays a key role in prostate cancer progression in Pten-null mice. Targeting Th17-IL-17 pathway could prevent micro-invasive prostate cancer formation in mice. Prostate 77:888-899, 2017. © 2017 Wiley Periodicals, Inc.

A comprehensive review of immunotherapies in prostate cancer

Prostate cancer is the second most common malignant neoplasm in men worldwide and the fifth cause of cancer-related death. Although multiple new agents have been approved for metastatic castration resistant prostate cancer over the last decade, it is still an incurable disease. New strategies to improve cancer control are needed and agents targeting the immune system have shown encouraging results in many tumor types. Despite being attractive for immunotherapies due to the expression of various tumor associated antigens, the microenvironment in prostate cancer is relatively immunosuppressive and may be responsible for the failures of various agents targeting the immune system in this disease. To date, sipuleucel-T is the only immunotherapy that has shown significant clinical efficacy in this setting, although the high cost and potential trial flaws have precluded its widespread incorporation into clinical practice. Issues with patient selection and trial design may have contributed to the multiple failures of immunotherapy in prostate cancer and provides an opportunity to tailor future studies to evaluate these agents more accurately. We have reviewed all the completed immune therapy trials in prostate cancer and highlight important considerations for the next generation of clinical trials.

Inflammatory cytokines IL-17 and TNF-α up-regulate PD-L1 expression in human prostate and colon cancer cells

Programmed cell death protein 1 (PD-1) acts on PD-1 ligands (PD-L1 and PD-L2) to suppress activation of cytotoxic T lymphocytes. Interleukin-17 (IL-17) and tumor necrosis factor-α (TNF-α) are co-expressed by T helper 17 (T_H17) cells in many tumors. The purpose of this study was to test if IL-17 and TNF-α may synergistically induce PD-L1 expression in human prostate cancer LNCaP and human colon cancer HCT116 cell lines. We found that IL-17 did not induce PD-L1 mRNA expression, but up-regulated PD-L1 protein expression in HCT116 and LNCaP cells. TNF-α induced PD-L1 mRNA and protein expression in both cell lines. Neither IL-17 nor TNF-α induced PD-L2 mRNA or protein expression. IL-17 and TNF-α acted individually rather than cooperatively in induction of PD-L1 expression. IL-17 and/or TNF-α activated AKT, nuclear factor-κB (NF-κB), and extracellular signal-regulated kinases 1/2 (ERK1/2) signaling pathways in HCT116 cells, whereas only NF-κB signaling was activated in LNCaP cells. NF-κB inhibitor could diminish PD-L1 protein expression induced by IL-17 and/or TNF-α in both HCT116 and LNCaP cell lines. ERK1/2 inhibitor could also reduce PD-L1 protein expression induced by IL-17 and/or TNF-α in HCT116 cells, while AKT inhibitor could abolish PD-L1 protein expression induced by IL-17 and/or TNF-α in LNCaP cells. These results suggest that IL-17 and TNF-α act individually rather than cooperatively through activation of NF-κB and ERK1/2 signaling to up-regulate PD-L1 expression in HCT116 cells, while the two inflammatory cytokines act through activation of NF-κB signaling, in the presence of AKT activity, to up-regulate PD-L1 expression in LNCaP cells.

Aminomethylphosphonic acid inhibits growth and metastasis of human prostate cancer in an orthotopic xenograft mouse model

Aminomethylphosphonic acid (AMPA) has been shown to inhibit prostate cancer cell growth in vitro. The purpose of the present study was to determine if AMPA could inhibit growth and metastasis of prostate cancer in vivo. Human prostate cancer PC-3-LacZ-luciferase cells were implanted into the ventral lateral lobes of the prostate in 39 athymic Nu/Nu nude male mice. Seven days later, mice were randomized into the control group (n = 14, treated intraperitoneally with phosphate buffered saline), low dose group (n = 10, treated intraperitoneally with AMPA at 400 mg/kg body weight/day), and high dose group (n = 15, treated intraperitoneally with AMPA at 800 mg/kg body weight/day). Tumor growth and metastasis were examined every 4-7 days by bioluminescence imaging of live mice. We found that AMPA treatment significantly inhibited growth and metastasis of orthotopic xenograft prostate tumors and prolonged the survival time of the mice. AMPA treatment decreased expression of BIRC2 and activated caspase 3, leading to increased apoptosis in the prostate tumors. AMPA treatment decreased expression of cyclin D1. AMPA treatment also reduced angiogenesis in the prostate tumors. Taken together, these results demonstrate that AMPA can inhibit prostate cancer growth and metastasis, suggesting that AMPA may be developed into a therapeutic agent for the treatment of prostate cancer.

Human antigen R is positively associated with malignant aggressiveness via upregulation of cell proliferation, migration, and vascular endothelial growth factors and cyclooxygenase-2 in prostate cancer

Limited information is available on the pathologic significance of human antigen R (HuR) in prostate cancer (PCa). The main aim of this study was to clarify the relationship between HuR expression and malignant aggressiveness, outcome, and expression of cancer-related molecules in PCa. In vitro proliferation, colony formation, and migration assays were performed on LNCaP and PC-3 cells. HuR expression was knocked down (KD) using small interfering RNA. The relationships between HuR expression and the expression of vascular endothelial growth factors (VEGFs), cyclooxygenase (COX)-2, and heme oxygenase (HO)-1 were investigated in PCa cell lines using Western blotting. On KD of HuR, cell proliferation and migration were suppressed in both LNCaP and PC-3 cells, whereas expression of VEGF-A to -D and COX-2 was suppressed in PC-3 but not in LNCaP cells. In addition, expression of these cancer-related factors was analyzed in 182 hormone-naïve PCa and 23 castration-resistant prostate cancer (CRPC) human tissues in vivo. Cytoplasmic (C)-HuR expression was significantly higher in CRPC > hormone-naïve PCa > nontumoral cells. C-HuR expression was positively associated with Gleason score, T stage, and metastasis, and it was considered to be a useful predictor of biochemical recurrence after radical prostatectomy. C-HuR expression was correlated with COX-2 expression in hormone-naïve PCa, and with the expression of VEGF-A, VEGF-C, and COX-2 in CRPC tissues. Our results demonstrated that HuR plays important roles in determining malignant aggressiveness and outcome in PCa, especially in androgen-independent PCa cells, via the regulation of cell proliferation, migration, and expression of VEGF-A, -C, and COX-2.

Interleukin-17 promotes prostate cancer via MMP7-induced epithelial-to-mesenchymal transition

Chronic inflammation has been associated with a variety of human cancers including prostate cancer. Interleukin-17 (IL-17) is a critical pro-inflammatory cytokine, which has been demonstrated to promote development of prostate cancer, colon cancer, skin cancer, breast cancer, lung cancer, and pancreas cancer. IL-17 promotes prostate adenocarcinoma with a concurrent increase of matrix metalloproteinase 7 (MMP7) expression in mouse prostate. Whether MMP7 mediates IL-17’s action and the underlying mechanisms remain unknown. We generated Mmp7 and Pten double knockout (Mmp7^−/− in abbreviation) mouse model and demonstrated that MMP7 promotes prostate adenocarcinoma through induction of epithelial-to-mesenchymal transition (EMT) in Pten-null mice. MMP7 disrupted E-cadherin/β-catenin complex to up-regulate EMT transcription factors in mouse prostate tumors. IL-17 receptor C and Pten double knockout mice recapitulated the weak EMT characteristics observed in Mmp7^−/− mice. IL-17 induced MMP7 and EMT in human prostate cancer LNCaP, C4-2B, and PC-3 cell lines, while siRNA knockdown of MMP7 inhibited IL-17-induced EMT. Compound III, a selective MMP7 inhibitor, decreased development of invasive prostate cancer in Pten single knockout mice. In human normal prostates and prostate tumors, IL-17 mRNA levels were positively correlated with MMP7 mRNA levels. These findings demonstrate that MMP7 mediates IL-17’s function in promoting prostate carcinogenesis through induction of EMT, indicating IL-17-MMP7-EMT axis as potential targets for developing new strategies in the prevention and treatment of prostate cancer.

Prospects for the use of ipilimumab in treating advanced prostate cancer

INTRODUCTION

Ipilimumab is a fully human monoclonal antibody that blocks Cytotoxic T lymphocyte-associated antigen 4 (CTLA-4) to potentiate antitumor T cell response. Ipilimumab is approved for the treatment of advanced melanoma based on improved overall survival. Clinical trials of ipilimumab in patients with metastatic castrate-resistant prostate cancer (mCRPC) have demonstrated some clinical activity, but have largely been disappointing to date.

AREAS COVERED

Results of key clinical studies of ipilimumab in the treatment of prostate cancer, including clinical efficacy and toxicities, are summarized.

EXPERT OPINION

There is likely a clinical benefit to ipilimumab in a subset of mCRPC patients. The development of biomarkers for enrichment treatment strategies that select for patients most likely to benefit from ipilimumab is a top priority. Similarly, an understanding of the factors predictive of toxicity will be important in the development of future treatment approaches.

IL-17 promoted the inhibition of medulloblastoma in mice by splenocyte injection

Background

Interleukin 17 (IL-17) is a proinflammatory cytokine produced by a new subset of activated CD4+ T cells, Th17 cells. We previously showed that increased Th17 cell populations were presented in human medulloblastoma-infiltrating T cells and peripheral blood. In this study, we attempted to address the possible role of Th17 cells in the biologic activity of IL-17 for tumor control.

Methods

We grafted fresh surgically obtained medulloblastoma into syngeneic athymic nude/nude mice. We intrapertonially injected splenocyte and murine IL-17 in mice on the second day. The tumor volume and the life spans of the mice were measured. Meanwhile, the IL-17, IL-6, IL-23, Ccl2, Ccl20 and IFN-gamma expression in the tumors was also examined by real-time PCR, Western blot and enzyme-linked immunosorbent assay.

Results

We found that medulloblastoma growth in IL-17-injected mice was significantly inhibited compared to the non-IL-17 treated mice. In contrast to the IL-17 antitumor activity observed in mice injected with splenocytes, we observed that IFN-gamma, IL-6, IL-23, Ccl2, and Ccl20 proteins were significantly increased in tumor tissues of mice injected with IL-17.

Conclusions

These experiments suggest that IL-17 may promote splenocyte antitumor activity in medulloblastoma. We postulate that IL-17’s antitumor activity may be related to the increased protein levels of IFN-gamma, IL-6, IL-23, Ccl2, and Ccl20.

Expression of IL-17A, E, and F and their receptors in human prostatic cancer: Comparison with benign prostatic hyperplasia

BACKGROUND

Benign prostatic hyperplasia (BPH) and prostate cancer (PCa) are the most common urological diseases in elderly men. Although studies suggest the cytokine family might be associated with BPH and PCa, there has been no systematic comparisons of expression of IL-17A, E, F and their receptors, infiltration of inflammatory cells, and changes in structural cells in PCa and BPH.

METHODS

Immunohistochemistry was employed to evaluate immunoreactivity for IL-17A, E, F and their receptors IL-17RA, IL-17BR, and IL-17CR, infiltration of inflammatory cells, and changes in structural cells including endothelial cells, fibroblasts, and smooth muscle cells in prostate tissues from subjects with PCa or BPH as well as controls.

RESULTS

Immunostaining showed that expression of immunoreactivity for IL-17A, IL-17RA, IL-17E, and IL-17F was significantly elevated in prostatic tissue from BPH and PCa compared with that in controls, which was accompanied by increased numbers of infiltrating inflammatory cells and CD31(+) blood vessels. Compared with BPH, PCa was characterized by reduced immunoreactivity for IL-17BR and reduced numbers of CD68(+) macrophages, fibroblasts, and smooth muscle cells, although there was a trend for these changes to correlate with disease severity in both PCa and BPH.

CONCLUSION

Our data are compatible with hypothesis that IL-17A acting through IL-17RA, but not IL-17CR contribute to the pathogenesis of BPH and PCa. In contrast, IL-17E interacting with the IL-17BR might have an anti-tumor effect.

In vitro and in vivo model systems used in prostate cancer research

New incidence of prostate cancer is a major public health issue in the Western world, and has been rising in other areas of the globe in recent years. In an effort to understanding the molecular pathogenesis of this disease, numerous cell models have been developed, arising mostly from patient biopsies. The introduction of the genetically engineered mouse in biomedical research has allowed the development of murine models that allow for the investigation of tumorigenic and metastatic processes. Current challenges to the field include lack of an animal model that faithfully recapitulates bone metastasis of prostate cancer.

IL-17 and insulin/IGF1 enhance adhesion of prostate cancer cells to vascular endothelial cells through CD44-VCAM-1 interaction

BACKGROUND

Extravasation is a critical step in cancer metastasis, in which adhesion of intravascular cancer cells to the vascular endothelial cells is controlled by cell surface adhesion molecules. The role of interleukin-17 (IL-17), insulin, and insulin-like growth factor 1 (IGF1) in adhesion of prostate cancer cells to the vascular endothelial cells is unknown, which is the subject of the present study.

METHODS

Human umbilical vein endothelial cells (HUVECs) and human prostate cancer cell lines (PC-3, DU-145, LNCaP, and C4-2B) were analyzed for expression of vascular cell adhesion molecule 1 (VCAM-1), integrins, and cluster of differentiation 44 (CD44) using flow cytometry and Western blot analysis. The effects of IL-17, insulin, and IGF1 on VCAM-1 expression and adhesion of prostate cancer cells to HUVECs were examined. The interaction of VCAM-1 and CD44 was assessed using immunoprecipitation assays.

RESULTS

Insulin and IGF1 acted with IL-17 to increase VCAM-1 expression in HUVECs. PC-3, DU-145, LNCaP, and C4-2B cells expressed β1 integrin but not α4 integrin. CD44 was expressed by PC-3 and DU-145 cells but not by LNCaP or C4-2B cells. When HUVECs were treated with IL-17, insulin or IGF1, particularly with a combination of IL-17 and insulin (or IGF1), adhesion of PC-3 and DU-145 cells to HUVECs was significantly increased. In contrast, adhesion of LNCaP and C4-2B cells to HUVECs was not affected by treatment of HUVECs with IL-17 and/or insulin/IGF1. CD44 expressed in PC-3 cells physically bound to VCAM-1 expressed in HUVECs.

CONCLUSIONS

CD44-VCAM-1 interaction mediates the adhesion between prostate cancer cells and HUVECs. IL-17 and insulin/IGF1 enhance adhesion of prostate cancer cells to vascular endothelial cells through increasing VCAM-1 expression in the vascular endothelial cells. These findings suggest that IL-17 may act with insulin/IGF1 to promote prostate cancer metastasis.

Tumor-Elicited Inflammation and Colorectal Cancer

The link between chronic inflammation and cancer has long been suspected, due to the pioneering work of Rudolf Virchow over 150 years ago. Yet the causal relationship between inflammation and cancer was only deciphered in the past decade or so, using animal models of various cancers. Up to 20% of all human cancers result from chronic inflammation and persistent infections. Proinflammatory cytokines and tumor-infiltrating myeloid and immune cells play critical roles in almost every developmental stages of inflammation-induced cancers, from initiation, promotion, and progression to malignant metastasis. However, even in cancers with no preceding inflammation, inflammatory cells infiltrate tumor stroma and contribute to cancer development. Such "tumor-elicited inflammation" further emphasizes the importance of inflammation in different types of cancers, including that of the colon. In this review, we summarize our current knowledge of the function and induction mechanisms of inflammatory cytokines during colorectal cancer development, and hope to provide insight into the development of novel anticancer therapies by modulating tumor-elicited inflammation.

Human colon carcinogenesis is associated with increased interleukin-17-driven inflammatory responses

Inflammation is known to contribute to carcinogenesis in human colorectal cancer. Proinflammatory cytokine interleukin-17 (IL-17 or IL-17A) has been shown to play a critical role in colon carcinogenesis in mouse models. However, few studies have investigated IL-17A in human colon tissues. In the present study, we assessed IL-17-driven inflammatory responses in 17 cases of human colon adenocarcinomas, 16 cases of human normal colon tissues adjacent to the resected colon adenocarcinomas, ten cases of human ulcerative colitis tissues from biopsies, and eight cases of human colon polyps diagnosed as benign adenomas. We found that human colon adenocarcinomas contained the highest levels of IL-17A cytokine, which was significantly higher than the IL-17A levels in the adenomas, ulcerative colitis, and normal colon tissues (P<0.01). The levels of IL-17 receptor A (IL-17RA) were also the highest in human colon adenocarcinomas, followed by adenomas and ulcerative colitis. The increased levels of IL-17A and IL-17RA were accompanied with increased IL-17-driven inflammatory responses, including activation of extracellular signal-regulated kinase (ERK)1/2 and c-Jun N-terminal kinase (JNK) pathways, increase in expression of matrix metalloproteinase (MMP)9, MMP7, MMP2, B-cell lymphoma (Bcl-2), and cyclin D1, decrease in Bcl-2-associated X protein (BAX) expression, and increase in vascular endothelial growth factor (VEGF) and VEGF receptor (VEGFR) expression that were associated with increased angiogenesis. These findings suggest that IL-17 and its signaling pathways appear as promising new targets in the design and development of drugs for cancer prevention and treatment, particularly in colorectal cancer.

AZD5363 Inhibits Inflammatory Synergy between Interleukin-17 and Insulin/Insulin-Like Growth Factor 1

In the United States, one-third of population is affected by obesity and almost 29 million people are suffering from type 2 diabetes. Obese people have elevated serum levels of insulin, insulin-like growth factor 1 (IGF1), and interleukin-17 (IL-17). Insulin and IGF1 are known to enhance IL-17-induced expression of inflammatory cytokines and chemokines, which may contribute to the chronic inflammatory status observed in obese people. We have previously demonstrated that insulin/IGF1 signaling pathway crosstalks with IL-17-activated nuclear factor-κB pathway through inhibiting glycogen synthase kinase 3β (GSK3β) activity. However, it is unclear whether GSK3α also plays a role and whether this crosstalk can be manipulated by AZD5363, a novel pan-Akt inhibitor that has been shown to increase glycogen synthase kinase 3 activity through reducing phosphorylation of GSK3α and GSK3β. In this study, we investigated IL-17-induced expression of C-X-C motif ligand 1 (Cxcl1), C-C motif ligand 20 (Ccl20), and interleukin-6 (Il-6) in wild-type, GSK3α^−/−, and GSK3β^−/− mouse embryonic fibroblast cells as well as in mouse prostate tissues by real-time quantitative PCR. We examined the proteins involved in the signaling pathways by Western blot analysis. We found that insulin and IGF1 enhanced IL-17-induced expression of Cxcl1, Ccl20, and Il-6, which was associated with increased phosphorylation of GSK3α and GSK3β in the presence of insulin and IGF1. AZD5363 inhibited the synergy between IL-17 and insulin/IGF1 through reducing phosphorylation of GSK3α and GSK3β by inhibiting Akt function. These findings imply that the cooperative crosstalk of IL-17 and insulin/IGF1 in initiating inflammatory responses may be alleviated by AZD5363.