Chemokine markers predict biochemical recurrence of prostate cancer following prostatectomy

Blood metabolites mediate the causal relationship between circulating CX3CL1 levels and prostate cancer: A 2-step Mendelian randomization study

Chemokines influence the progression of prostate cancer (PCa) through multiple mechanisms. However, the effect of C-X3-C chemokine ligand 1 (CX3CL1) on PCa risk remains controversial. Our study aimed to investigate whether circulating CX3CL1 is causally associated with PCa and to identify metabolites that have mediating effects using the 2-step bidirectional Mendelian randomization (MR) analysis process. Inverse variance weighting (IVW) results were used as the primary observations, while additional sensitivity analyses were conducted. For each standard deviation increase exhibited by the circulating CX3CL1 levels, the risk of PCa was reduced by 0.4% (IVW: OR = 0.996, [95% CI = 0.994-0.998], P < .001), and blood alliin levels increased by 19% (IVW: OR = 1.185, [95% CI = 1.01-1.54], P = .003). For each standard deviation increase in the blood alliin levels, the risk of PCa was reduced by 0.1% (IVW: OR = 0.999, [95% CI = 0.997-0.999], P = .03). Therefore, the protective effect of circulating CX3CL1 on PCa may be mediated by blood alliin levels (mediated proportion = 6.7%). The results supported the notion that high levels of circulating CX3CL1 indicate a lower PCa risk and the idea that the food-derived antioxidant alliin may mediate this association. We emphasize that the use of CX3CL1 as a protective factor against PCa may provide new strategies for PCa prevention and care in the future.

Identification of cell differentiation trajectory-related gene signature to reveal the prognostic significance and immune landscape in prostate cancer based on multiomics analysis

Background

In the context of prostate cancer (PCa), the occurrence of biochemical recurrence (BCR) stands out as a pivotal factor significantly impacting prognosis, potentially leading to metastasis and mortality. However, the early detection of BCR poses a substantial challenge for PCa patients. There is an urgent need to pinpoint hub genes that can serve as predictive indicators for BCR in PCa patients.

Methods

Our primary goal was to identify cell differentiation trajectory-related gene signature in PCa patients by pseudo-time trajectory analysis. We further explored the functional enrichment of overlapped marker genes and probed clinically relevant modules and BCR-related genes using Weighted Gene Co-expression Network Analysis (WGCNA) in PCa patients. Key genes predicting recurrence-free survival were meticulously identified through univariate and multivariate Cox regression analyses. Subsequently, these genes were utilized to construct a prognostic gene signature, the expression, predictive efficacy, putative functions, and immunological landscape of which were thoroughly validated. Additionally, we employed immunohistochemistry (IHC) and a western blotting assay to quantify the expression of PYCR1 in clinical samples.

Results

Our single-cell RNA (scRNA) sequencing analysis unveiled three subgroups characterized by distinct differentiation trajectories, and the marker genes associated with these groups were extracted from PCa patients. These marker genes successfully classified the PCa sample into two molecular subtypes, demonstrating a robust correlation with clinical characteristics and recurrence-free survival. Through WGCNA and Lasso analysis, we identified four hub genes (KLK3, CD38, FASN, and PYCR1) to construct a risk profile of prognostic genes linked to BCR. Notably, the high-risk patient group exhibited elevated levels of B cell naive, Macrophage M0, and Macrophage M2 infiltration, while the low-risk group displayed higher levels of T cells CD4 memory activated and monocyte infiltration. Furthermore, IHC and western blotting assays confirmed the heightened expression of PYCR1 in PCa tissues.

Conclusion

This study leveraged the differentiation trajectory and genetic variability of the microenvironment to uncover crucial prognostic genes associated with BCR in PCa patients. These findings present novel perspectives for tailoring treatment strategies for PCa patients on an individualized basis.

Genetically Predicted Circulating Levels of Cytokines and the Risk of Cancer

Background

Inflammation plays a pivotal role in the pathogenesis of cancer. Though previous studies have reported a link between several inflammatory biomarkers and risk of certain types of cancer, there is a lack of systematic investigation. Therefore, we aimed to assess the role of circulating cytokines on the risk of cancer using a two-sample Mendelian randomization (MR) approach.

Method

We used genetic variants associated with circulating levels of cytokines from a meta-analysis of genome-wide association studies (GWASs) of 8,293 Finns as instrumental variables. Summary level data of 20 site-specific cancer were obtained from the UK BioBank including up to 456,348 participants of European ancestry. We performed two-sample MR analyses using inverse-variance weighted (IVW) method as the main method, followed by weighted-median and likelihood-based methods as sensitivity analysis. Pleiotropic and outlier variants were assessed by MR-Egger regression and MR Pleiotropy RESidual Sum and Outlier (MR-PRESSO) test.

Results

224 genetic variants associated with 27 circulating cytokines achieving genome-wide significance (P<5×10^-8) were used as IVs. After Bonferroni correction, genetically predicted high levels of interleukin-18 (IL-18) were associated with a decreased risk of acute myeloid leukemia (odds ratio (OR) per 1 standard deviation (SD) increase = 0.55, 95% confidence interval (CI):0.43-0.69, P=5.39×10^-7), and circulating levels of IL-17 were associated with altered stomach cancer risk (OR per 1 SD increase = 0.15, 95% CI: 0.07-0.36, P=1.25×10^-5) by IVW. Results were stable across sensitivity analyses, and MR-Egger regression did not suggest the presence of directional pleiotropy. Additionally, we found suggestive evidence for 48 cytokine-cancer associations including tumor necrosis factor related apoptosis-inducing ligand (TRAIL) and cutaneous T-cell attracting chemokine (CTACK) with the risk of several types of cancer (9.26×10^-5≤P<0.05).

Conclusions

By using a genetic epidemiological approach, our study systematically evaluated the role of circulating cytokines on the risk of cancer, and provided clues for potential therapeutic targets. However, the exact underlying biological mechanism warrants further investigation.

Interleukin-15 and cancer: some solved and many unsolved questions

Soluble interleukin (IL)-15 exists under two forms: as monomer (sIL-15) or as heterodimeric complex in association with sIL-15Rα (sIL-15/IL-15Rα). Both forms have been successfully tested in experimental tumor murine models and are currently undergoing investigation in phase I/II clinical trials. Despite more than 20 years research on IL-15, some controversial issues remain to be addressed. A first point concerns the detection of the sIL-15/IL-15Rα in plasma of healthy donors or patients with cancer and its biological significance. The second and third unsolved question regards the protumorigenic role of the IL-15/IL-15Rα complex in human cancer and the detrimental immunological consequences associated to prolonged exposure of natural killer (NK) cells to both forms of soluble IL-15, respectively. Data suggest that in vivo prolonged or repeated exposure to monomeric sIL-15 or the soluble complex may lead to NK hypo-responsiveness through the expansion of the CD8⁺/CD44⁺ T cell subset that would suppress NK cell functions. In vitro experiments indicate that soluble complex and monomeric IL-15 may cause NK hyporesponsiveness through a direct effect caused by their prolonged stimulation, suggesting that this mechanism could also be effective in vivo. Therefore, a better knowledge of IL-15 and a more appropriate use of both its soluble forms, in terms of concentrations and time of exposure, are essential in order to improve their therapeutic use. In cancer, the overproduction of sIL-15/IL-15Rα could represent a novel mechanism of immune escape. The soluble complex may act as a decoy cytokine unable to efficiently foster NK cells, or could induce NK hyporesponsiveness through an excessive and prolonged stimulation depending on the type of IL-15Rα isoforms associated. All these unsolved questions are not merely limited to the knowledge of IL-15 pathophysiology, but are crucial also for the therapeutic use of this cytokine. Therefore, in this review, we will discuss key unanswered issues on the heterogeneity and biological significance of IL-15 isoforms, analyzing both their cancer-related biological functions and their therapeutic implications.

Clinical outcomes associated with prostate cancer conspicuity on biparametric and multiparametric MRI: a protocol for a systematic review and meta-analysis of biochemical recurrence following radical prostatectomy

INTRODUCTION

There is an increasing body of evidence to suggest that visibility of prostate cancer on magnetic resonance (MRI) may be related to likelihood of adverse pathological outcomes. Biochemical recurrence (BCR) after radical prostatectomy remains a significant clinical challenge and a means of predicting likelihood of this prior to surgery could inform treatment choice. It appears that MRI could be a potential candidate strategy for BCR prediction, and as such, there is a need to review extant literature on the prognostic capability of MRI. Here, we describe a protocol for a systematic review and meta-analysis of the utility of biparametric MRI (bpMRI) and multiparametric MRI (mpMRI) in predicting BCR following radical prostatectomy for prostate cancer treatment.

METHODS AND ANALYSIS

PubMed, MEDLINE, Embase and Cochrane databases will be searched and screening will be guided by the Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) guidelines. In order to meet the inclusion criteria, papers must be English-language articles involving patients who have had bpMRI or mpMRI for suspected prostate cancer and have undergone radical prostatectomy as definitive therapy. Patients must have had prostate-specific antigen monitoring before and after surgery. All relevant papers published from July 1977 to October 2020 will be eligible for inclusion. The Newcastle-Ottawa score will be used to determine the quality and bias of the studies. This protocol is written in-line with the PRISMA protocol 2015 checklist.

ETHICS AND DISSEMINATION

There are no relevant ethical concerns. Dissemination of this protocol will be via peer-reviewed journals as well as national and international conferences.

PROSPERO REGISTRATION NUMBER

CRD42020206074.

Low Expression of IL-15 and NKT in Tumor Microenvironment Predicts Poor Outcome of MYCN-Non-Amplified Neuroblastoma

Immune tumor microenvironment (TME) in neuroblastoma (NBL) contributes to tumor behavior and treatment response. T cells and natural killer (NK) cells have been shown to play important roles in the neuroblastoma TME. However, few reports address the clinical relevance of natural killer T cells (NKTs) and interleukin-15 (IL-15), one of the crucial cytokines controlling the activation and expansion of NK/NKT cells, in NBL. In this study, we examined NKT immunoscores and IL-15 expression in both MYCN-amplified and MYCN-non-amplified NBL to correlate with clinical outcomes such as event-free survival (EFS) and overall survival (OS). From Gene Expression Omnibus (GEO) datasets GSE45480 (n = 643) and GSE49711 (n = 493), we found that NKT immunoscore and IL-15 expression were both significantly lower in MYCN-amplified NBL, and similar results were observed using our clinical NBL samples (n = 53). Moreover, NBL patients (GEO dataset GSE49711 and our clinical samples) with both lower NKT immunoscore and IL-15 expression exhibited decreased EFS and OS regardless of MYCN gene amplification status. Multivariate analysis further showed that the combination of low NKT immunoscore and low IL-15 expression level was an independent prognostic factor for poor EFS and OS in our NBL patients. These findings provide the rationale for the development of strategy to incorporate IL-15 and NKT cell therapy into the treatment regimen for neuroblastoma.

Interleukin 15 and Eotaxin correlate with the outcome of breast cancer patients vice versa independent of CTC status

Background

Circulating tumor cells (CTC) in the peripheral blood in women with breast cancer has been found to be an indicator of prognosis before the start of systemic treatment. The aim of this study is the assessment of specific cytokine profiles as markers for CTC involvement that could act as independent prognostic markers in terms of survival outcome for breast cancer patients.

Methods

Patients selected for this study were defined as women with breast cancer of the SUCCESS study. A total of 200 patients’ sera were included in this study, 100 patients being positive for circulating tumor cells (CTC) and 100 patients being CTC negative. The matching criteria were histo-pathological grading, lymph node metastasis, hormone receptor status, TNM classification, and patient survival. Commercial ELISA with a multi cytokine/chemokine array was used to screen the sera for Interleukin 15 (IL-15) and eotaxin.

Results

Statistically significant concentrations were exposed for IL-15 levels regardless of the CTC-Status, lymph node involvement, or hormone receptor status. Significantly enhanced serum IL-15 concentrations were observed in those patients with worse overall survival (OS) and disease-free survival (DFS). Elevated serum concentrations of IL-15 significantly correlate with patients diagnosed with Grade 3 tumor and worse OS. In contrast, patients with a Grade 3 tumor with a favourable OS and DFS demonstrated significantly decreased IL-15 values. The CTC negative patient subgroup with a favourable OS and DFS, showed statistically significant elevated eotaxin values.

Conclusion

These findings suggest a potential functional interaction of increased IL-15 concentrations in the peripheral blood of patients with a worse OS and DFS, regardless of prognostic factors at primary diagnosis. The increased levels of the chemokine eotaxin in CTC negative patients and a favourable OS and DFS, on the other hand, suggest that the overexpression inhibits CTCs entering the peripheral blood, thus emphasizing a significant inhibition of circulation specific metastasis. To sum up, IL-15 could be used as an independent prognostic marker in terms of survival outcome for breast cancer patients and used as an early indicator to highlight high-risk patients and consequently the adjustment of cancer therapy strategies.

Genetically predicted levels of circulating cytokines and prostate cancer risk: A Mendelian randomization study

Inflammation is considered to play a pivotal role in the pathogenesis of cancer, and observational studies have reported a relationship between circulating inflammation markers and the risk of prostate cancer. Using summary data of >140 000 individuals, two-sample Mendelian randomization (MR) analyses were performed to evaluate whether circulating levels of 27 cytokines and growth factors have a causal effect on the risk of developing prostate cancer. Genetically predicted elevated levels of monocyte chemotactic protein-1 (MCP-1) were associated with an increased risk of prostate cancer (odds ratio (OR) per 1 SD increase = 1.06, 95% confidence interval (CI): 1.04-1.09) at Bonferroni-adjusted level of significance (P < 1.85 × 10^-3). Results were stable across sensitivity analyses, and there was no evidence of directional pleiotropy. Under MR assumptions, our findings suggested a risk-increasing effect of circulating MCP-1 levels on prostate cancer. Whether targeting MCP-1 or its downstream effectors are useful in reducing prostate cancer incidence needs further investigation.

Contrast-enhanced transrectal ultrasound can reduce collection of unnecessary biopsies when diagnosing prostate cancer and is predictive of biochemical recurrence following a radical prostatectomy in patients with localized prostate cancer

Background

To investigate the value of using contrast-enhanced transrectal ultrasound (CETRUS) to reduce unnecessary collection of biopsies during prostate cancer diagnosis and its utility in predicting biochemical recurrence in patients with localized prostate cancer.

Methods

This was a prospective study of suspected prostate cancer patients who were evaluated with CETRUS followed by a prostate biopsy. Prostate blood flow via CETRUS was graded using a 5-point scale. The relationship between CETRUS score and biopsy outcome was then analyzed for all patients; univariate and multi-variate analyses were used to determine the probable prognostic factors for biochemical recurrence in patients with localized prostate cancer that underwent a radical prostatectomy.

Results

A total of 347 patients were enrolled in the study. Prostate cancer was found in 164 patients. A significant positive correlation (r = 0.69, p < 0.001) was found between CETRUS scores and prostate cancer incidence. Using CETRUS scores ≥2 as the threshold for when to biopsy could have safely reduced the number of biopsies taken overall by 12.1% (42/347) and spared 23.0% (42/183) of patients from undergoing an unnecessary biopsy. 77 patients with localized prostate cancer underwent a radical prostatectomy. The median follow-up time was 30 months (range: 8–56 months) and 17 of these 77 patients exhibited biochemical recurrence during the follow-up period. 3-year biochemical recurrence-free survival rates were 86% for patients with low CETRUS scores (≤ 3) and 59% for patients with high scores (> 3; p = 0.015). Multivariate Cox regression analysis indicated that CETRUS score was an independent predictor of biochemical recurrence (HR: 7.02; 95% CI: 2.00–24.69; p = 0.002).

Conclusions

CETRUS scores may be a useful tool for reducing the collection unnecessary biopsy samples during prostate cancer diagnosis and are predictive of biochemical recurrence in patients with localized prostate cancer following a radical prostatectomy.

Analysis of outcomes after non-contour-based dose painting of dominant intra-epithelial lesion in intra-operative low-dose rate brachytherapy

Purpose

To compare the outcomes of patients with intermediate risk prostate cancer (IR-PCa) treated with low-dose rate I-125 seed brachytherapy (LDR-BT) and targeted dose painting of a histologic dominant intra-epithelial lesion (DIL) to those without a DIL.

Methods

455 patients with IR-PCa were treated at a single center with intra-operatively planned LDR-BT, each following the same in-house dose constraints. Patients with a DIL on pathology had hot spots localized to that region but no specific contouring during the procedure.

Results

396 (87%) patients had a DIL. Baseline tumor characteristics and overall prostate dosimetry were similar between patients with and without DIL except the median number of biopsy cores taken: 10 (10–12) vs 12 (10–12) (p = 0.002).

19 (5%) and 18 (5%) of patients with and 1 (2%) and 0 (0%) of those without DIL experienced CTCAE grade 2 and 3 toxicity respectively. Overall, toxicity grade did not significantly correlate with presence of DIL (p = 0.10).

Estimated 7-year freedom from biochemical failure (FFBF) was 84% (95% confidence interval: 79–89) and 70% (54–89) in patients with and without a DIL (log-rank p = 0.315). In DIL patients, cox regression revealed location of DIL (“Base” vs “Apex” HR: 1.03; 1.00–1.06; p = 0.03) and older age (70 vs 60 HR: 1.62; 1.06–2.49; p = 0.03) was associated with poor FFBF.

Conclusions

Targeting DIL through dose painting during intraoperatively planned LDR-BT provided no statistically significant change in FFBF. Patients with DILs in the prostate base had slightly lower FFBF despite DIL boost.

Circulating inflammation markers and prostate cancer

BACKGROUND

Chronic inflammation is thought to influence the risk of prostate cancer. The purpose of this population-based case-control study was to evaluate the association of 48 circulating inflammation markers with prostate cancer, to identify candidate markers for further investigation.

METHODS

Serum samples collected from 235 prostate cancer patients and 198 population-based controls recruited in Örebro County, Sweden, in 1989-1991, were assessed using a multiplex bead-based immunoassay to determine concentrations of 48 circulating inflammation markers. Logistic regression was first used to evaluate the association between individual markers (highest vs lowest concentration quartile) and prostate cancer in unadjusted and mutually adjusted models. Second, patients with inflammatory conditions, metastatic or advanced prostate cancer, were excluded to address the possible influence of systemic disease on inflammation markers.

RESULTS

Individual analyses first identified 21 markers associated with prostate cancer (P < .05), which after mutual adjustment were reduced to seven markers. After the exclusion of men with conditions linked with systemic inflammation, associations between prostate cancer and deviant levels of C-X3-C motif chemokine ligand 1, platelet-derived growth factor subunit B homodimer, interleukin 10, C-C motif chemokine ligand (CCL) 21, and CCL11 remained statistically significant.

CONCLUSIONS

In this explorative study, we identified candidate inflammation markers of possible importance for prostate cancer pathophysiology, for further evaluation in prospective studies.

Transcriptome analysis reveals a long non-coding RNA signature to improve biochemical recurrence prediction in prostate cancer

Despite highly successful treatments for localized prostate cancer (PCa), prognostic biomarkers are needed to improve patient management and prognosis. Accumulating evidence suggests that long noncoding RNAs (lncRNAs) are key regulators with biological and clinical significance. By transcriptome analysis, we identified a set of consistently dysregulated lncRNAs in PCa across different datasets and revealed an eight-lncRNA signature that significantly associated with the biochemical recurrence (BCR)-free survival. Based on the signature, patients could be classified into high- and low-risk groups with significantly different survival (HR = 2.19; 95% CI = 1.67-2.88; P < 0.0001). Validations in the validation cohorts and another independent cohort confirmed its prognostic value for recurrence prediction. Multivariable analysis showed that the signature was independent of common clinicopathological features and stratified analysis further revealed its role in elevating risk stratification of current prognostic models. Additionally, the eight-lncRNA signature was able to improve on the CAPRA-S score for the prediction of BCR as well as to reflect the metastatic potential of PCa. Functional characterization suggested that these lncRNAs which showed PCa-specific expression patterns may involve in critical processes in tumorigenesis. Overall, our results demonstrated potential application of lncRNAs as novel independent biomarkers. The eight-lncRNA signature may have clinical potential for facilitating further stratification of more aggressive patients who would benefit from adjuvant therapy.

Macrophage migration inhibitory factor: a potential driver and biomarker for head and neck squamous cell carcinoma

Macrophage migration inhibitory factor (MIF), a pleiotropic proinflammatory cytokine, has been showed to be associated with the immunopathogenesis of many diseases. Recent study demonstrated that MIF promoted tumorigenesis and tumor progression and played a critical role in various kinds of human cancer including head and neck squamous cell carcinoma(HNSCC). Hence, in this paper we retrospected the relationship between MIF and angiogenesis, epithelial-mesenchymal transition (EMT), inflammation, immune response, hypoxia microenvironment, and discussed whether it is a promising biomarker for diagnosis and supervisor of HNSCC.

Melatonin represses oral squamous cell carcinoma metastasis by inhibiting tumor-associated neutrophils

Tumor-associated neutrophils (TANs) promote metastasis of multiple cancers, including oral squamous cell carcinoma (OSCC). Melatonin (Mel) reportedly exerts anti-metastatic effects on OSCC. However, little is known about the anti-OSCC effects of Mel involved in TANs. In this study, intensive infiltration of TANs was positively associated with advanced stage, lymphatic metastasis, and poor prognosis of OSCC. Moreover, Mel reduced the survival and migration of OSCC-associated neutrophils. Mechanistically, Mel suppressed the TAN release of C-X-C motif chemokine ligand 8, C-C motif chemokine ligand 2 (CCL2), CCL4, and matrix metalloproteinase-9 by blockage of p38 MAPK and Akt signaling. Mel-fostered TANs decreased the migration and invasion of OSCC cells and reduced tube formation in vitro. Additionally, Mel-hampered pro-motility and pro-angiogenesis effects of TANs were dependent on MMP-9 suppression in OSCC. Overall, The beneficial roles of melatonin in retarding OSCC metastasis were implicated with inhibition of TANs.

CCL4 promotes the cell proliferation, invasion and migration of endometrial carcinoma by targeting the VEGF-A signal pathway

Chemokine (C-C motif) ligand 4 (CCL4) and vascular endothelial growth factor-A (VEGF-A) are involved in the progression and metastasis of some tumors, including ovarian cancer, colon cancer and prostate cancer. However, the roles of CCL4 and VEGF-A in human endometrial cancer (EC) are still unclear. Here, we demonstrated that the production of CCL4 and VEGF-A was significantly higher in EC tissues than in normal tissues, and their expression profiles were associated with the clinical stage of EC. In addition, we found that CCL4 promoted the angiogenesis and invasive ability of EC tumors by increasing the production of VEGF-A. We further confirmed the effect of CCL4 in the growth of EC tumors by silencing the expression of CCL4 in EC cell lines. Finally, we found that CCL4 upregulated VEGF-A expression by activating STAT3, and it enhanced the progression and metastasis of EC. Our study showed that CCL4 promoted tumor growth by upregulating VEGF-A expression, which affected the STAT3 signal pathway in the EC cells.

Association between Recipient IL-15 Genetic Variant and the Prognosis of HBV-Related Hepatocellular Carcinoma after Liver Transplantation

Objective

To investigate the association of donor and recipient IL-15 genetic variants with HCC recurrence and prognosis after LT.

Methods

A total of 112 liver transplant patients with HBV-related HCC were enrolled. IL-15 rs10519613 and rs13122930 were genotyped in donors and recipients.

Results

Recipient IL-15 rs10519613 polymorphism was found to be significantly related to HCC recurrence after LT. In multivariate analysis, tumor thrombus, UCSF criteria, and recipient IL-15 rs10519613 genotypes were independent predictive factors of HCC recurrence after LT. Kaplan-Meier survival analysis demonstrated that patients with recipient IL-15 rs10519613 CA/AA genotypes had a decreased disease-free survival and overall survival than those with the CC genotype. Recipient IL-15 rs10519613 genetic variant could improve survival prediction when combined with the UCSF criteria. Furthermore, Cox proportional hazard regression analysis revealed that tumor size (p = 0.012, p = 0.623), tumor thrombus (p = 0.011, p = 0.015), UCSF criteria (p = 0.471, p = 0.013), and recipient IL-15 rs10519613 genotype (p = 0.039, p = 0.008) were independent factors of predicting DFS and OS.

Conclusions

Recipient IL-15 rs10519613 polymorphism was associated with HCC recurrence after LT and might be a potential genetic marker for the clinical outcome of HCC patients treated with LT.

IL-15 regulates migration, invasion, angiogenesis and genes associated with lipid metabolism and inflammation in prostate cancer

Prostate cancer (PCa) is the most commonly diagnosed non-cutaneous cancer. In the United States it is second leading cause of cancer related deaths in men. PCa is often treated via radical prostatectomy (RP). However, 15–30% of the patients develop biochemical recurrence (i.e. increased serum prostate specific antigen (PSA) levels). Interleukin-15 (IL-15) is a secreted cytokine found over expressed in patients with recurrence-free survival after RP. In our study, we aim to determine the role of IL-15 in PCa using in vitro and in vivo models, and gene expression analysis. PC3 (androgen-independent) and 22RV1 (androgen-dependent) cell lines were treated with IL-15 at 0.0013 ng/mL and 0.1 ng/mL. Tumor growth was evaluated using an orthotopic xenograft model. The anterior prostate lobes of SCID mice were injected with 250,000 22RV1 cells and IL-15 was administered bi-weekly with intraperitoneal (IP) injections during 4 weeks. Tumor tissue was collected for immunohistochemical and gene expression analysis. To study changes in gene expression, we looked at “Tumor Metastasis” and “PI3K pathway” using commercially available PCR arrays. In addition, we employed a microarray approach using the Affymetrix Hugene 2.0 ST array chip followed by analysis with Ingenuity Pathways Analysis (IPA) software. In vitro studies showed that IL-15 decreased PCa cell motility at both concentrations. In vivo studies showed that IL-15 increased neutrophil infiltration, and the expression of adiponectin, desmin and alpha smooth muscle actin (α-sma) in the tumor tissue. Angiogenesis analysis, using CD31 immunohistochemistry, showed that IL-15 decreased the number of blood vessels. Gene expression analysis identified Cancer, Cell Death, Immune Response and Lipid Metabolism as the major diseases and functions altered in tumors treated with IL-15. This suggests that IL-15 causes inflammation and changes in stroma that can promote decreased tumor cell proliferation.

CX3CL1 increases invasiveness and metastasis by promoting epithelial-to-mesenchymal transition through the TACE/TGF-α/EGFR pathway in hypoxic androgen-independent prostate cancer cells

Epithelial-to-mesenchymal transition (EMT) endows cancer cells with enhanced invasive and metastatic potential during cancer progression. Fractalkine, also known as chemokine (C-X3-C motif) ligand 1 (CX3CL1), the only member recognized so far that belongs to the CX3C chemokine subfamily, was reported to participate in the molecular events that regulate cell adhesion, migration and survival of human prostate cancer cells. However, the relationship between CX3CL1 and EMT remains unknown. We treated DU145 and PC-3 cells with CX3CL1 under hypoxic conditions. The migration and invasion abilities of DU145 and PC-3 cells were detected by Transwell assays. Induction of EMT was verified by morphological changes in the DU145 and PC-3 cells and analysis of protein expression of EMT markers such as E-cadherin and vimentin. To identify the involved signaling pathway in CX3CL1-induced EMT, activation of epidermal growth factor receptor (EGFR) was measured using western blot analysis, and Slug expression was detected with or without an EGFR inhibitor prior to CX3CL1 treatment. Concentrations of soluble and total TGF-α in the CX3CL‑treated DU145 cells were detected by ELISA. Additionally, we determined the involvement of the TACE/TGF-α/EGFR pathway in CX3CL1‑induced EMT using RNA interference and specific inhibitors. CX3CL1 increased the migration and invasiveness of the DU145 and PC-3 cells, and resulted in characteristic alterations of EMT. Our results demonstrated that TACE/TGF-α/EGFR pathway activation and subsequent upregulation of Slug expression were responsible for CX3CL1‑induced EMT, and contributed to the migration and inva-sion of prostate cancer cells. Inhibition of TACE/TGF-α/EGFR signaling reversed EMT and led to reduced migration and invasion abilities of the prostate cancer cells. We provide initial evidence that CX3CL1 exposure resulted in EMT occurrence and enhancement of cell migration and invasion through a mechanism involving activation of TACE/TGF-α/EGFR signaling. These findings revealed that CX3CL1 may serve as a new target for the treatment of prostate cancer.

Upregulation of fractalkine contributes to the proliferative response of prostate cancer cells to hypoxia via promoting the G1/S phase transition

Hypoxia is a common phenomenon in prostate cancer, which leads to cell proliferation and tumor growth. Fractalkine (FKN) is a membrane-bound chemokine, which is implicated in the progression of human prostate cancer and skeletal metastasis. However, the association between FKN and hypoxia-induced prostate cancer cell proliferation remains to be elucidated. The present study demonstrated that hypoxia induced the expression and secretion of FKN in the DU145 prostate cancer cell line. Furthermore, inhibiting the activity of FKN with the anti-FKN FKN-specific antibody markedly inhibited hypoxia-induced DU145 cell proliferation. Under normoxic conditions, DU145 cell proliferation markedly increased following exogenous administration of human recombinant FKN protein, and the increase was significantly alleviated by anti-FKN, indicating the importance of FKN in DU145 cell proliferation. In addition, subsequent determination of cell cycle distribution and expression levels of two core cell cycle regulators, cyclin E and cyclin-dependent kinase (CDK)2, suggested that FKN promoted the G₁/S phase transition by upregulating the expression levels of cyclin E and CDK2. The results of the present study demonstrated that hypoxia led to the upregulation of the secretion and expression of FKN, which enhanced cell proliferation by promoting cell cycle progression in the prostate cancer cells. These findings provide evidence of a novel function for FKN, and suggest that FKN may serve as a potential target for treating androgen-independent prostate cancer.

Serum levels of chemokines CCL4 and CCL5 in cirrhotic patients indicate the presence of hepatocellular carcinoma

BACKGROUND

Most hepatocellular carcinomas (HCCs) are diagnosed at an advanced stage. The prognostic value of serum tumour markers alpha-fetoprotein (AFP) and des-gamma-carboxy prothrombin (DCP) is limited. The aim of our study is to evaluate the diagnostic value of serum growth factors, apoptotic and inflammatory mediators of cirrhotic patients with and without HCC.

METHODS

Serum samples were collected from cirrhotic potential liver transplant patients (LTx) with (n=61) and without HCC (n=78) as well as from healthy controls (HCs; n=39). Serum concentrations of CRP, neopterin and IL-6 as markers of inflammation and thrombopoietin (TPO), GCSF, FGF basic and VEGF, HMGB1, CK-18 (M65) and CK18 fragment (M30) and a panel of proinflammatory chemokines (CCL2, CCL3, CCL4, CCL5, CXCL5 and IL-8) were measured. Chi square, Fisher exact, Mann-Whitney U-tests, ROC curve analysis and forward stepwise logistic regression analyses were applied.

RESULTS

Patients with HCC had higher serum TPO and chemokines (P<0.001 for TPO, CCL4, CCL5 and CXCL5) and lower CCL2 (P=0.008) levels than cirrhotic patients without HCC. Multivariate forward stepwise regression analysis for significant parameters showed that among the studied parameters CCL4 and CCL5 (P=0.001) are diagnostic markers of HCC. Serum levels of TPO and chemokines were lower, whereas M30 was significantly higher in cirrhotic patients than in HCs.

CONCLUSIONS

High serum levels of inflammatory chemokines such as CCL4 and CCL5 in the serum of cirrhotic patients indicate the presence of HCC.

Diagnosis of inflammatory bowel disease: Potential role of molecular biometrics

Accurate diagnosis of predominantly colonic inflammatory bowel disease (IBD) is not possible in 30% of patients. For decades, scientists have worked to find a solution to improve diagnostic accuracy for IBD, encompassing Crohn's colitis and ulcerative colitis. Evaluating protein patterns in surgical pathology colectomy specimens of colonic mucosal and submucosal compartments, individually, has potential for diagnostic medicine by identifying integrally independent, phenotype-specific cellular and molecular characteristics. Mass spectrometry (MS) and imaging (I) MS are analytical technologies that directly measure molecular species in clinical specimens, contributing to the in-depth understanding of biological molecules. The biometric-system complexity and functional diversity is well suited to proteomic and diagnostic studies. The direct analysis of cells and tissues by Matrix-Assisted-Laser Desorption/Ionization (MALDI) MS/IMS has relevant medical diagnostic potential. MALDI-MS/IMS detection generates molecular signatures obtained from specific cell types within tissue sections. Herein discussed is a perspective on the use of MALDI-MS/IMS and bioinformatics technologies for detection of molecular-biometric patterns and identification of differentiating proteins. I also discuss a perspective on the global challenge of transferring technologies to clinical laboratories dealing with IBD issues. The significance of serologic-immunometric advances is also discussed.

Diagnosis of inflammatory bowel disease: Potential role of molecular biometrics

Accurate diagnosis of predominantly colonic inflammatory bowel disease (IBD) is not possible in 30% of patients. For decades, scientists have worked to find a solution to improve diagnostic accuracy for IBD, encompassing Crohn’s colitis and ulcerative colitis. Evaluating protein patterns in surgical pathology colectomy specimens of colonic mucosal and submucosal compartments, individually, has potential for diagnostic medicine by identifying integrally independent, phenotype-specific cellular and molecular characteristics. Mass spectrometry (MS) and imaging (I) MS are analytical technologies that directly measure molecular species in clinical specimens, contributing to the in-depth understanding of biological molecules. The biometric-system complexity and functional diversity is well suited to proteomic and diagnostic studies. The direct analysis of cells and tissues by Matrix-Assisted-Laser Desorption/Ionization (MALDI) MS/IMS has relevant medical diagnostic potential. MALDI-MS/IMS detection generates molecular signatures obtained from specific cell types within tissue sections. Herein discussed is a perspective on the use of MALDI-MS/IMS and bioinformatics technologies for detection of molecular-biometric patterns and identification of differentiating proteins. I also discuss a perspective on the global challenge of transferring technologies to clinical laboratories dealing with IBD issues. The significance of serologic-immunometric advances is also discussed.

The absence or overexpression of IL-15 drastically alters breast cancer metastasis via effects on NK cells, CD4 T cells, and macrophages

IL-15 is a cytokine that can affect many immune cells, including NK cells and CD8 T cells. In several tumor models, IL-15 delays primary tumor formation and can prevent or reduce metastasis. In this study, we have employed a model of breast cancer metastasis to examine the mechanism by which IL-15 affects metastasis. When breast tumor cells were injected i.v. into IL-15(-/-), C57BL/6, IL-15 transgenic (TG) and IL-15/IL-15Rα-treated C57BL/6 mice, there were high levels of metastasis in IL-15(-/-) mice and virtually no metastasis in IL-15 TG or IL-15-treated mice. In fact, IL-15(-/-) mice were 10 times more susceptible to metastasis, whereas IL-15 TG mice were at least 10 times more resistant to metastasis when compared with control C57BL/6 mice. Depletion of NK cells from IL-15 TG mice revealed that these cells were important for protection from metastasis. When NK cells were depleted from control C57BL/6 mice, these mice did not form as many metastatic foci as IL-15(-/-) mice, suggesting that other cell types may be contributing to metastasis in the absence of IL-15. We then examined the role of CD4 T cells and macrophages. In IL-15(-/-) mice, in vivo depletion of CD4 T cells decreased metastasis. The lack of IL-15 in IL-15(-/-) mice, and possibly the Th2-polarized CD4 T cells, was found to promote the formation of M2 macrophages that are thought to contribute to metastasis formation. This study reveals that whereas IL-15 effects on NK cells are important, it also has effects on other immune cells that contribute to metastasis.

CCL2 Chemokine as a Potential Biomarker for Prostate Cancer: A Pilot Study

Purpose

Prostate specific antigen is not reliable in diagnosing prostate cancer (PCa), making the identification of novel, precise diagnostic biomarkers important. Since chemokines are associated with more aggressive disease and poor prognosis in diverse malignancies, we aimed to investigate the diagnostic relevance of chemokines in PCa.

Materials and Methods

Preoperative and early postoperative serum samples were obtained from 39 consecutive PCa patients undergoing radical prostatectomy. Serum from 15 healthy volunteers served as controls. Concentrations of CXCL12, CXCL13, CX3CL1, CCL2, CCL5, and CCL20 were measured in serum by Luminex. The expression activity of CXCR3, CXCR4, CXCR5, CXCR7, CXCL12, CXCL13, CX3CR1, CXCL1, CCR2, CCR5, CCR6, CCR7, CCL2, and CCL5 mRNA was assessed in tumor and adjacent normal tissue of prostatectomy specimens by quantitative real-time polymerase chain reaction. The associations of these chemokines with clinical and histological parameters were tested.

Results

The gene expression activity of CCL2 and CCR6 was significantly higher in tumor tissue compared to adjacent normal tissue. CCL2 was also significantly higher in the blood samples of PCa patients, compared to controls. CCL5, CCL20, and CX3CL1 were lower in patient serum, compared to controls. CCR2 tissue mRNA was negatively correlated with the Gleason score and grading.

Conclusion

Chemokines are significantly modified during tumorigenesis of PCa, and CCL2 is a promising diagnostic biomarker.

New concepts concerning prostate cancer screening

Prostate Cancer (CaP) is rapidly becoming a worldwide health issue. While CaP mortality has decreased in recent years, coincident with the widespread use of Prostate-Specific Antigen (PSA) screening, it remains the most common solid tumor in men and is the second leading cause of cancer death in the United States. The frequency of CaP is growing not only in western cultures, but also its incidence is dramatically increasing in eastern nations. Recently, examination of data from long-term trials and follow up has cast a shadow on the effectiveness of employing PSA as a primary screening tool for CaP. In this review, we not only summarize opinions from this examination and synthesize recommendations from several groups that suggest strategies for utilizing PSA as a tool, but also call for research into biomarkers for CaP diagnosis and disease progression. We also describe our recent work that identified a smooth muscle contractile protein in prostate epithelia, namely smooth muscle gamma actin, and indicate the potential for this molecule as a new unique footprint and as a CaP marker.

High-grade prostate cancer and biochemical recurrence after radical prostatectomy among men using 5α-reductase inhibitors and alpha-blockers

BACKGROUND

Two clinical trials have shown that users of 5α-reductase inhibitors finasteride and dutasteride (5-ARIs) have reduced overall prostate cancer risk, while the proportion of high-grade tumors is increased. We studied tumor characteristics, risk of biochemical recurrence and mortality after radical prostatectomy in 5-ARI and alpha-blocker users.

METHODS

The study cohort consisted of 1,315 men who underwent radical prostatectomy at the Tampere University Hospital during 1995-2009. Biochemical relapse was defined as serum PSA ≥ 0.2 ng/ml after the operation. Information on mortality and medication purchases was obtained from national registries. Cox proportional regression was used to analyze hazard ratios (HRs) and 95% confidence intervals (95% CI) of biochemical relapse and death.

RESULTS

The proportion of high-grade (Gleason 7-10) tumors was significantly elevated among men who had used 5-ARIs for 4 years or longer compared to the non-users (83.3% vs. 53.3%, respectively). Survival curves for biochemical relapse-free survival differed between long-term and short-term 5-ARI users, but the hazard ratio remained statistically non-significant. Risk of biochemical recurrence was elevated among alpha-blocker users (HR 1.68, 95% CI 1.37-2.06), but in sensitivity analyses this was evident only in men using alpha-blockers after prostatectomy. Mortality was not associated with medication usage.

CONCLUSIONS

Long-term users of finasteride or dutasteride had more often high-grade prostate cancer. Our results suggest also worse progression-free survival. The association between risk of biochemical recurrence and post-operative alpha-blocker usage suggests that voiding or storage symptoms after prostatectomy may predict biochemical relapse.

Pyuria predicts poor prognosis in patients with non-muscle-invasive bladder cancer

BACKGROUND

To evaluate the significance of inflammation in non-muscle-invasive bladder cancer (NMIBC), we assessed the presence of pyuria at time of diagnosis.

PATIENTS AND METHODS

A cohort of 805 patients with newly diagnosed NMIBC between 1994 and 2007 at the Tokyo Metropolitan Tama Medical Center were enrolled in this retrospective study. Pyuria was defined as urine containing ≥ 10 white blood cells (WBCs) per high power field (HPF).

RESULTS

One hundred ninety-nine (24%) of the patients with NMIBC had pyuria. The 3-year recurrence-free survival rates of patients with and without pyuria were 10.9 vs. 45.0%, respectively. The 5-year progression-free survival rates of patients with and without pyuria were 72.3% and 95.7%, respectively. Multivariate Cox proportional hazards regression models indicated that pyuria was an independent predictor of disease recurrence and progression. After dividing the sample according to the European Organization for Research and Treatment of Cancer (EORTC) risk tables, we further classified patients into subgroups according to the presence of pyuria. The recurrence-free survival rates were higher in the pyuria-negative subgroups of the low, intermediate-low, intermediate-high, and high risk for recurrence groups. Similarly, the progression-free survival rates at 5 years were higher in the pyuria-negative subgroups of the low, intermediate-low, and intermediate-high risk for progression groups.

CONCLUSION

Patients with inflammatory NMIBC exhibited poor clinical outcomes.

Influence of fractalkine receptor gene polymorphisms V249I-T280M on cancer occurrence after renal transplantation

BACKGROUND

Fractalkine (CX3CL1) and its receptor (CX3CR1) are involved in antitumor immunity. Two common single nucleotide polymorphisms of the CX3CR1 gene, V249I and T280M, have been associated with reduced fractalkine signaling characterized by decreased adhesive function, signaling, and chemotaxis of leukocytes. We hypothesized that a renal transplant recipient (RTR) carrying the homozygous I249M280 genotype could experience more cancer due to lower CX3CL1-dependent antitumorigenic effects.

METHODS

We studied the association between these polymorphisms and cancer incidence in two independent cohorts of RTR, including a total of 622 patients.

RESULTS

The median follow-up was 8.7 and 7.9 years for the first and second cohorts, respectively. Analysis of 622 patients identified 20 (3.2%) I249M280 homozygous patients, 321 (51.6%) V249T280 homozygous patients, and 281 (45.2%) heterozygous patients. I249M280 homozygotes have an independent increased risk of cancer (hazard ratio [95% confidence interval], 3.3 [1.04-10.52], P=0.043 for cohort 1 and 9.2 [1.67-50.91], P=0.011 for cohort 2) compared with other patients. Age and male gender were also risk factors for cancer occurrence.

CONCLUSIONS

CX3CR1 gene polymorphism is associated with a higher rate of cancer in RTRs. Such findings may be used to influence immunosuppressive strategies and optimize patient management.

Metastatic ability: adapting to a tissue site unseen

The microenvironment of the primary as well as the metastatic tumor sites can determine the ability for a disseminated tumor to progress. In this issue of Cancer Cell, Calon and colleagues find that systemic TGF-β can facilitate colon cancer metastatic engraftment and expansion.

Prevalence of prostate cancer metastases after intravenous inoculation provides clues into the molecular basis of dormancy in the bone marrow microenvironment

Bone is the preferred metastasis site of advanced prostate cancer (PCa). Using an in vivo murine model of human PCa cell metastasis to bone, we noted that the majority of animals that develop skeletal metastasis have either spinal lesions or lesions in the bones of the hindlimb. Much less frequently, lesions develop in the bones of the forelimb. We therefore speculated whether the environment of the forelimb bones is not permissive for the growth of PCa. Consequently, data on tumor prevalence were normalized to account for the number of PCa cells arriving after intravascular injection, marrow cellularity, and number of hematopoietic stem cell niches. None of these factors were able to account for the observed differences in tumor prevalence. An analysis of differential gene and protein levels identified that growth arrest specific-6 (GAS6) levels were significantly greater in the forelimb versus hindlimb bone marrow. When murine RM1 cells were implanted into subcutaneous spaces in immune competent animals, tumor growth in the GAS6(-/-) animals was greater than in GAS6(+/+) wild-type animals. In an osseous environment, the human PC3 cell line grew significantly better in vertebral body transplants (vossicles) derived from GAS6(-/-) animals than in vossicles derived from GAS6(+/+) animals. Together, these data suggest that the differences in tumor prevalence after intravascular inoculation are a useful model to study the molecular basis of tumor dormancy. Importantly, these data suggest that therapeutic manipulation of GAS6 levels may prove useful as a therapy for metastatic disease.

Serum methionine metabolites are risk factors for metastatic prostate cancer progression

BACKGROUND

Clinical decision for primary treatment for prostate cancer is dictated by variables with insufficient specificity. Early detection of prostate cancer likely to develop rapid recurrence could support neo-adjuvant therapeutics and adjuvant options prior to frank biochemical recurrence. This study compared markers in serum and urine of patients with rapidly recurrent prostate cancer to recurrence-free patients after radical prostatectomy. Based on previous identification of urinary sarcosine as a metastatic marker, we tested whether methionine metabolites in urine and serum could serve as pre-surgical markers for aggressive disease.

METHODOLOGY/PRINCIPAL FINDINGS

Urine and serum samples (n = 54 and 58, respectively), collected at the time of prostatectomy were divided into subjects who developed biochemical recurrence within 2 years and those who remained recurrence-free after 5 years. Multiple methionine metabolites were measured in urine and serum by GC-MS. The role of serum metabolites and clinical variables (biopsy Gleason grade, clinical stage, serum prostate specific antigen [PSA]) on biochemical recurrence prediction were evaluated. Urinary sarcosine and cysteine levels were significantly higher (p = 0.03 and p = 0.007 respectively) in the recurrent group. However, in serum, concentrations of homocysteine (p = 0.003), cystathionine (p = 0.007) and cysteine (p<0.001) were more abundant in the recurrent population. The inclusion of serum cysteine to a model with PSA and biopsy Gleason grade improved prediction over the clinical variables alone (p<0.001).

CONCLUSIONS

Higher serum homocysteine, cystathionine, and cysteine concentrations independently predicted risk of early biochemical recurrence and aggressiveness of disease in a nested case control study. The methionine metabolites further supplemented known clinical variables to provide superior sensitivity and specificity in multivariable prediction models for rapid biochemical recurrence following prostatectomy.

Molecular genetics of prostate cancer: new prospects for old challenges

Despite much recent progress, prostate cancer continues to represent a major cause of cancer-related mortality and morbidity in men. Since early studies on the role of the androgen receptor that led to the advent of androgen deprivation therapy in the 1940s, there has long been intensive interest in the basic mechanisms underlying prostate cancer initiation and progression, as well as the potential to target these processes for therapeutic intervention. Here, we present an overview of major themes in prostate cancer research, focusing on current knowledge of principal events in cancer initiation and progression. We discuss recent advances, including new insights into the mechanisms of castration resistance, identification of stem cells and tumor-initiating cells, and development of mouse models for preclinical evaluation of novel therapuetics. Overall, we highlight the tremendous research progress made in recent years, and underscore the challenges that lie ahead.

Role of monocyte-lineage cells in prostate cancer cell invasion and tissue factor expression

BACKGROUND

Tissue factor (TF) is a cell surface glycoprotein intricately related to blood coagulation and inflammation. This study was performed to investigate the role of monocyte-lineage cells in prostate cancer cell TF expression and cell invasion.

METHODS

Prostate cancer cell invasion was tested with and without added peripheral blood monocytes or human monocyte-lineage cell lines. TF neutralizing antibodies were used to determine the TF requirement for prostate cancer cell invasion activity. Immunohistochemistry was performed to identify prostate tissue CD68 positive monocyte-derived cells and prostate epithelial TF expression.

RESULTS

Co-culture of PC-3, DU145, and LNCaP cells with isolated human monocytes significantly stimulated prostate cancer cell invasion activity. TF expression was greater in highly invasive prostate cancer cells and was induced in PC-3, DU145, and LNCaP cells by co-culture with U-937 cells, but not with THP-1 cells. TF neutralizing antibodies inhibited PC-3 cell invasion in co-cultures with monocyte-lineage U-937 or THP-1 cells. Prostate cancer tissues contained more CD68 positive cells in the stroma and epithelium (145 ± 53/mm(2)) than benign prostate (108 ± 31/mm(2)). Samples from advanced stage prostate cancer tended to contain more CD68 positive cells when compared with lower stage lesions. Prostatic adenocarcinoma demonstrated significantly increased TF expression compared with benign prostatic epithelium.

CONCLUSIONS

This study shows that co-culture with monocyte-lineage cells induced prostate cancer cell invasion activity. PC-3 invasion and TF expression was induced in co-culture with U-937 cells and partially inhibited with TF neutralizing antibodies.

Application of proteomic technologies for prostate cancer detection, prognosis, and tailored therapy

Prostate cancer affects 3 in 10 men over the age of 50 years, and, unfortunately, the clinical course of the disease is poorly predicted. At present, there is no means that can distinguish indolent from aggressive/metastatic tumors. Thus, a personalized clinical approach could be helpful in diagnosing clinically relevant disease and guiding appropriate patient therapy. Individualized medicine requires a deep knowledge of the molecular mechanisms underpinning prostate cancer carcinogenesis. Proteomics may be the most powerful way to uncover biomarkers of detection, prognosis, and prediction, as proteins do the work of the cell and represent the majority of the diagnostic markers and drug targets today. Proteomic technologies are rapidly advancing beyond the two-dimensional gel separation techniques of the past to new types of mass spectrometry and protein microarray analyses. Biological fluids and tissue-cell proteomes from men with prostate cancer are being explored to identify diagnostic and prognostic biomarkers and therapeutic targets using these new proteomic approaches. Traditional and novel proteomic technology and their application to prostate cancer studies in translational research will be presented and discussed in this review. Proteomics coupled with powerful nanotechnology-based biomarker discovery approaches may provide a new and exciting opportunity for body fluid-borne biomarker discovery and characterization. While innovative mass spectrometry technology and nanotrap could be applied to improve the discovery and measurement of biomarkers for the early detection of prostate cancer, the use of tissue proteomic tools such as the reverse-phase protein microarray may provide new approaches for personalization of therapies tailored to each tumor's unique pathway activation network.

Fractalkine/CX3CR1: why a single chemokine-receptor duo bears a major and unique therapeutic potential

IMPORTANCE OF THE FIELD

Fractalkine, also known as CX3CL1, is the unique member of the fourth class of chemokines and mediates both chemotaxis and adhesion of inflammatory cells via its highly selective receptor CX3CR1. Fractalkine mediates inflammatory responses and pain sensation and is involved in the pathogenesis and progression of numerous inflammatory disorders and malignancies.

AREAS COVERED IN THIS REVIEW

We performed a Medline/PubMed search to detect all published studies that explored the role of fractalkine and CX3CR1 and the possibilities of therapeutic intervention in the fractalkine/CX3CR1 axis in a wide range of clinical disorders, using CX3CR1 blocking antibodies, different fractalkine antagonists, CX3CR1 depletion or transfection of fractalkine expression vectors.

WHAT THE READER WILL GAIN

This review summarizes the role of fractalkine and its receptor CX3CR1 in various diseases, focusing on their high potential as novel therapeutic targets, with special emphasis on pancreatic diseases.

TAKE HOME MESSAGE

The reviewed studies provide promising results demonstrating fractalkine and CX3CR1 as potential target molecules for future therapeutics that may attenuate pain, inflammation and furthermore serve as an anti-cancer therapy. However, to date, no therapeutics targeting fractalkine or CX3CR1 are in clinical use.

Association between statins and prostate tumor inflammatory infiltrate in men undergoing radical prostatectomy

BACKGROUND

Cholesterol-lowering drugs known as statins have been reported to have significant anti-inflammatory properties. Given that inflammation may contribute to prostate cancer progression and that statins may reduce the risk for advanced prostate cancer, we investigated whether statin use was associated with reduced intratumoral inflammation in radical prostatectomy (RP) specimens.

METHODS

Inflammation within index tumors of 236 men undergoing RP from 1996 to 2004 was graded by a single pathologist as grade 0 (absent), 1 (mild: < or =10%), and 2 (marked: >10%). Preoperative statin use was analyzed by grouping subjects as statin users or nonusers. Type and dosage of statin was accounted for using dose equivalents with 20 mg simvastatin as reference. Logistic regression was used to determine the association between statin use and intratumoral inflammation controlling for age, race, body mass index, prostate-specific antigen, year of surgery, clinical stage, pathologic Gleason sum, surgical margin status, extracapsular extension, seminal vesicle invasion, prostate weight, time from prostate biopsy to RP, and nonsteroidal anti-inflammatory drug use.

RESULTS

Preoperative statin use was significantly associated with lower risk for any (grade > or =1) intratumoral inflammation (odds ratio, 0.31; 95% confidence interval, 0.10-0.98; P = 0.047) on multivariable analysis, with doses > or =20 mg simvastatin equivalents being more strongly associated (relative to nonuse; odds ratio, 0.22; 95% confidence interval, 0.06-0.79; P = 0.02).

CONCLUSION

In a cohort of men undergoing RP, statin use was associated with significantly lower risk of any inflammation within prostate tumors.

IMPACT

Given previous reports that inflammation is associated with advanced prostate cancer, and statin use is associated with decreased prostate cancer progression risk, our findings suggest that inhibition of inflammation within tumors may be a potential mechanism for purported anti-prostate cancer properties of statins.

Gene expression relationship between prostate cancer cells of Gleason 3, 4 and normal epithelial cells as revealed by cell type-specific transcriptomes

BACKGROUND

Prostate cancer cells in primary tumors have been typed CD10-/CD13-/CD24hi/CD26+/CD38lo/CD44-/CD104-. This CD phenotype suggests a lineage relationship between cancer cells and luminal cells. The Gleason grade of tumors is a descriptive of tumor glandular differentiation. Higher Gleason scores are associated with treatment failure.

METHODS

CD26+ cancer cells were isolated from Gleason 3+3 (G3) and Gleason 4+4 (G4) tumors by cell sorting, and their gene expression or transcriptome was determined by Affymetrix DNA array analysis. Dataset analysis was used to determine gene expression similarities and differences between G3 and G4 as well as to prostate cancer cell lines and histologically normal prostate luminal cells.

RESULTS

The G3 and G4 transcriptomes were compared to those of prostatic cell types of non-cancer, which included luminal, basal, stromal fibromuscular, and endothelial. A principal components analysis of the various transcriptome datasets indicated a closer relationship between luminal and G3 than luminal and G4. Dataset comparison also showed that the cancer transcriptomes differed substantially from those of prostate cancer cell lines.

CONCLUSIONS

Genes differentially expressed in cancer are potential biomarkers for cancer detection, and those differentially expressed between G3 and G4 are potential biomarkers for disease stratification given that G4 cancer is associated with poor outcomes. Differentially expressed genes likely contribute to the prostate cancer phenotype and constitute the signatures of these particular cancer cell types.

Chronic pancreatitis and pancreatic cancer: prediction and mechanism

We investigated the SPINK 1 mutations in 156 sporadic pancreatic cancer (PCa), and 8 pancreatic cancer with chronic pancreatitis (CPPCa) patients, and in 527 healthy subjects. The results demonstrated that 3 of 8 patients with CPPCa (37.5%) had the SPINK 1 gene N34S mutation. In addition, 3 of 156 sporadic PCa patients (1.9%) and 1 of them (0.6%) had the N34S and IVS3+2T>C mutation, respectively. The combined frequency of 2.5% was significantly higher than that of healthy subjects (0.38%), suggesting that the SPINK 1 mutation is an important risk factor for the development of pancreatic cancer. To investigate the genetic difference between sporadic PCa and CPPCa, we investigated several factors involved in the pathogenesis of PCa in 6 CPPCa and 15 sporadic PCa patients. The factors examined were genes including K-ras, p53, smad 4, p-smad 1, CXCL 14, NF-kB subunit p65 and Wnt 5a. No significant difference was found in the comparative examination of these factors, suggesting that the molecular disorders appeared to occur similarly in CPPCa as well as sporadic PCa. To assess the role of fibrosis in pancreatic carcinogenesis, we investigated the effects of pancreatic stellate cells (PSCs), which are largely responsible for pancreatic fibrogenesis, on duct cells, in vitro and in vivo. Activated PSCs were found surrounding precancerous duct cells in the tissues of a dimethylbenzanthracene mouse model and those of human PCa. Consistently, human pancreatic epithelial duct cells cultured with PSC conditioned media showed increased cell proliferation and colony formation, suggesting that PSCs may promote pancreatic ductal tumorigenesis.

Gene expression down-regulation in CD90+ prostate tumor-associated stromal cells involves potential organ-specific genes

Background

The prostate stroma is a key mediator of epithelial differentiation and development, and potentially plays a role in the initiation and progression of prostate cancer. The tumor-associated stroma is marked by increased expression of CD90/THY1. Isolation and characterization of these stromal cells could provide valuable insight into the biology of the tumor microenvironment.

Methods

Prostate CD90⁺ stromal fibromuscular cells from tumor specimens were isolated by cell-sorting and analyzed by DNA microarray. Dataset analysis was used to compare gene expression between histologically normal and tumor-associated stromal cells. For comparison, stromal cells were also isolated and analyzed from the urinary bladder.

Results

The tumor-associated stromal cells were found to have decreased expression of genes involved in smooth muscle differentiation, and those detected in prostate but not bladder. Other differential expression between the stromal cell types included that of the CXC-chemokine genes.

Conclusion

CD90⁺ prostate tumor-associated stromal cells differed from their normal counterpart in expression of multiple genes, some of which are potentially involved in organ development.

The good and the bad of chemokines/chemokine receptors in melanoma

Chemokine ligand/receptor interactions affect melanoma cell growth, stimulate or inhibit angiogenesis, recruit leukocytes, promote metastasis, and alter the gene expression profile of the melanoma associated fibroblasts. Chemokine/chemokine receptor interactions can protect against tumor development/growth or can stimulate melanoma tumor progression, tumor growth and metastasis. Metastatic melanoma cells express chemokine receptors that play a major role in the specifying the organ site for metastasis, based upon receptor detection of the chemokine gradient elaborated by a specific organ/tissue. A therapeutic approach that utilizes the protective benefit of chemokines involves delivery of angiostatic chemokines or chemokines that stimulate the infiltration of cytotoxic T cells and natural killer T cells into the tumor microenvironment. An alternative approach that tackles the tumorigenic property of chemokines uses chemokine antibodies or chemokine receptor antagonists to target the growth and metastatic properties of these interactions. Based upon our current understanding of the role of chemokine-mediated inflammation in cancer, it is important that we learn to appropriately regulate the chemokine contribution to the tumorigenic 'cytokine/chemokine storm', and to metastasis.