Macrophage inhibitory cytokine-1: possible bridge molecule of inflammation and prostate cancer

Integrated analysis of single-cell and bulk RNA sequencing identifies a signature based on macrophage marker genes involved in prostate cancer prognosis and treatment responsiveness

In the tumor microenvironment, tumor-associated macrophages (TAMs) interact with cancer cells and contribute to the progression of solid tumors. Nonetheless, the clinical significance of TAM-related biomarkers in prostate cancer (PCa) is largely unexplored. The present study aimed to construct a macrophage-related signature (MRS) for predicting PCa patient prognosis based on macrophage marker genes. Six cohorts comprising 1056 PCa patients with RNA-Seq and follow-up data were enrolled. Based on macrophage marker genes identified by single-cell RNA-sequencing (scRNA-seq) analysis, univariate analysis, least absolute shrinkage and selection operator (Lasso)-Cox regression, and machine learning procedures were performed to derive a consensus MRS. Receiver operating characteristic curve (ROC), concordance index, and decision curve analyses were used to confirm the predictive capacity of the MRS. The predictive performance of the MRS for recurrence-free survival (RFS) was stable and robust, and the MRS outperformed traditional clinical variables. Furthermore, high-MRS-score patients presented abundant macrophage infiltration and high-expression levels of immune checkpoints (CTLA4, HAVCR2, and CD86). The frequency of mutations was relatively high in the high-MRS-score subgroup. However, the low-MRS-score patients had a better response to immune checkpoint blockade (ICB) and leuprolide-based adjuvant chemotherapy. Notably, abnormal ATF3 expression may be associated with docetaxel and cabazitaxel resistance in PCa cells, T stage, and the Gleason score. In this study, a novel MRS was first developed and validated to accurately predict patient survival outcomes, evaluate immune characteristics, infer therapeutic benefits, and provide an auxiliary tool for personalized therapy.

Macrophage inhibitory cytokine-1 in cancer: Beyond the cellular phenotype

Despite technological advances in diagnostic abilities and improved treatment methods, the burden of cancers remains high, leading to significant morbidity and mortality. One primary reason is that cancer cell secretory factors modulate the tumor microenvironment, supporting tumor growth and circumvents anticancer activities of conventional therapies. Macrophage inhibitory cytokine-1 (MIC-1) is a pleiotropic cytokine elevated in various cancers. MIC-1 regulates various cancer hallmarks, including sustained proliferation, tumor-promoting inflammation, avoiding immune destruction, inducing invasion, metastasis, angiogenesis, and resisting cell death. Despite these facts, the molecular regulation and downstream signaling of MIC-1 in cancer remain elusive, partly because its receptor (GFRAL) was unknown until recently. Binding of MIC-1 to GFRAL recruits the coreceptor tyrosine kinase RET to execute its downstream signaling. So far, studies have shown that GFRAL expression is restricted to the brain stem and is responsible for MIC-1/GFRAL/RET-mediated metabolic disorders. Nevertheless, abundant levels of MIC-1 expression have been reported in all cancer types and have been proposed as a surrogate biomarker. Given the ubiquitous expression of MIC-1 in cancers, it is crucial to understand both upstream regulation and downstream MIC-1/GFRAL/RET signaling in cancer hallmark traits.

Growth Differentiation Factor-15 Correlates with Mortality and Severity in Severe Burns

BACKGROUND

Growth differentiation factor-15 (GDF-15) is expressed in almost all tissues of the body and is necessary for the body's defense response to stress such as inflammation. It has been reported to be associated with incidence and mortality in many diseases, including systemic inflammatory response syndromes. There are no reports on GDF-15 in burns. The purpose of this study was to investigate the trend of GDF-15 in blood in patients with severe burns and to determine its relationship with severity and mortality.

METHODS

This was a retrospective, observational, single-center study. The level of GDF-15 in the blood was measured and compared with clinical parameters, including prognosis. Time points for sample collection were the day of injury, 4 days after injury, and 1 week after injury.

RESULTS

Eighty-three patients were enrolled in the study. At all time points, GDF-15 levels in the nonsurvivor group were significantly higher than those in the survivor group. In the analysis using the ROC curve for 28-day survival, the AUC of the GDF-15 value on the day of injury was 0.798, which was higher than those of % total body surface area, burn index, and Sequential Organ Failure Assessment (SOFA) score. GDF-15 levels correlated positively with SOFA score, and the relationship became stronger along with the time course of severe burn.

CONCLUSIONS

In the acute phase of severe burn, GDF-15 levels were associated with mortality and SOFA scores.

A Perspective on Withania somnifera Modulating Antitumor Immunity in Targeting Prostate Cancer

Medicinal plants serve as a lead source of bioactive compounds and have been an integral part of day-to-day life in treating various disease conditions since ancient times. Withaferin A (WFA), a bioactive ingredient of Withania somnifera, has been used for health and medicinal purposes for its adaptogenic, anti-inflammatory, and anticancer properties long before the published literature came into existence. Nearly 25% of pharmaceutical drugs are derived from medicinal plants, classified as dietary supplements. The bioactive compounds in these supplements may serve as chemotherapeutic substances competent to inhibit or reverse the process of carcinogenesis. The role of WFA is appreciated to polarize tumor-suppressive Th1-type immune response inducing natural killer cell activity and may provide an opportunity to manipulate the tumor microenvironment at an early stage to inhibit tumor progression. This article signifies the cumulative information about the role of WFA in modulating antitumor immunity and its potential in targeting prostate cancer.

Interleukin-13 rs1800925/-1112C/T promoter single nucleotide polymorphism variant linked to anti-schistosomiasis in adult males in Murehwa District, Zimbabwe

Background

Chronic schistosomiasis is predominantly induced through up-regulation of inflammatory cytokines such as interleukin (IL)-13. IL-13 may contribute to the disease outcomes by increasing eosinophil infiltration thereby promoting fibrosis. IL-13 may act as an immunosuppressive inflammatory cytokine that may promote carcinogenesis and also may offer protection against schistosomiasis thereby reducing risk of schistosome infections. Our study evaluated the frequency of the IL-13 rs1800925/-1112 C/ T promoter single nucleotide polymorphisms (SNPs) among schistosomiasis infected individuals and assessed the association of the variants on IL-13 cytokine levels. We also investigated IL-13 rs1800925 polymorphisms on prostate-specific antigen levels as an indicator for risk of prostate cancer development.

Methodology

The study was cross-sectional and included 50 schistosomiasis infected and 316 uninfected male participants residing in Murehwa District, Zimbabwe. IL-13 rs1800925 SNPs were genotyped by allele amplification refractory mutation system-polymerase chain reaction. Concentrations of serum prostate-specific antigens and plasma IL-13 were measured using enzyme-linked immunosorbent assay.

Results

Frequencies of the genotypes CC, CT and TT, were 20%, 58% and 22% in schistosomiasis infected, and 18.3%, 62.1% and 19.6% in uninfected participants with no statistical differences. There were significantly (p<0.05) higher IL-13 cytokine levels among both infected and uninfected participants with the genotypes CC and CT; median 92.25 pg/mL and 106.5 pg/mL, respectively, compared to TT variant individuals; 44.78 pg/mL. Within the schistosomiasis uninfected group, CC and CT variants had significantly (p<0.05) higher IL-13 levels; median 135.0 pg/mL and 113.6 pg/mL, respectively compared to TT variant individuals; 47.15 pg/mL. Within the schistosomiasis infected group, CC, CT and TT variant individuals had insignificant differences of IL-13 level. Using logistic regression, no association was observed between prostate-specific antigen levels, IL-13 cytokine levels and IL-13 rs1800925 variants (p>0.05).

Conclusion

IL-13 rs1800925 C variant individuals had the highest IL-13 cytokine levels among the schistosomiasis uninfected suggesting that they may be protective against Schistosoma infections. There was no association between IL-13 concentrations or IL-13 rs1800925 variants and risk of prostate cancer indicating that IL-13 levels and IL-13 rs10800925 may not be utilised as biomarker for risk of prostate cancer in schistosome infections.

Circulatory MIC-1 as a Determinant of Prostate Cancer Racial Disparity

Simple Summary

African American men are diagnosed with more aggressive prostate cancer and have worse outcomes than Caucasians. This study examined the role of MIC-1 as a risk factor and demonstrated a conceptual observation for the differential level of MIC-1 in circulation (serum and urine) and tumor tissues from prostate cancer patients of racial disparity. The circulatory MIC-1 levels in serum and urine are significantly higher in prostate cancer patients of African American ethnicity, with higher sensitivity and specificity than Caucasians. The validation of circulatory MIC-1 in a larger cohort of patients may help identify high-risk prostate cancer patients and develop race-oriented therapies to reduce the observed cancer outcome gaps between the races.

Abstract

In this study, we investigated the potential of MIC-1 (macrophage inhibitory cytokine-1) on the severity of prostate cancer between African American men and Caucasians. Differences between the races were examined using Mann–Whitney tests for continuous variables and Fisher’s exact tests for categorical variables. Pearson’s correlation coefficient was used to identify associations between continuous measures across all samples and within each race. Analysis of variance, including clinical parameters, was used to identify differences in serum and urine MIC-1 levels between races. We found significant differences between the two races for age (p = 0.01), Gleason scores (p = 0.01), and stage of disease (p = 0.03). African American men in the study had higher Gleason scores (mean = 6.9) than Caucasians (mean = 6.5), during earlier stages of the disease. In Caucasian men with prostate cancer, serum MIC-1 expression was positively associated with age (r = 0.7, p < 0.01). However, African American men had highly expressed MIC-1 and high Gleason scores (r = 0.16, p = 0.3). Interestingly, the urine MIC-1 level was significantly higher in African American men with prostate cancer than in Caucasian patients. It appeared to be more sensitive and specific for African Americans (AUC = 0.85 vs. 0.56). Thus, high circulatory MIC-1 in prostate cancer patients may indicate MIC-1 as a potential biomarker to improve the diagnostic ability of an aggressive stage of prostate cancer in African American men. However, a larger cohort of sample analysis is required to validate these observations.

Renoprotective and Immunomodulatory Effects of GDF15 following AKI Invoked by Ischemia-Reperfusion Injury

BACKGROUND

Gdf15 encodes a TGF-β superfamily member that is rapidly activated in response to stress in multiple organ systems, including the kidney. However, there has been a lack of information about Gdf15 activity and effects in normal kidney and in AKI.

METHODS

We used genome editing to generate a Gdf15 ^nuGFP-CE mouse line, removing Gdf15 at the targeted allele, and enabling direct visualization and genetic modification of Gdf15-expressing cells. We extensively mapped Gdf15 expression in the normal kidney and following bilateral ischemia-reperfusion injury, and quantified and compared renal responses to ischemia-reperfusion injury in the presence and absence of GDF15. In addition, we analyzed single nucleotide polymorphism association data for GDF15 for associations with patient kidney transplant outcomes.

RESULTS

Gdf15 is normally expressed within aquaporin 1-positive cells of the S3 segment of the proximal tubule, aquaporin 1-negative cells of the thin descending limb of the loop of Henle, and principal cells of the collecting system. Gdf15 is rapidly upregulated within a few hours of bilateral ischemia-reperfusion injury at these sites and new sites of proximal tubule injury. Deficiency of Gdf15 exacerbated acute tubular injury and enhanced inflammatory responses. Analysis of clinical transplantation data linked low circulating levels of GDF15 to an increased incidence of biopsy-proven acute rejection.

CONCLUSIONS

Gdf15 contributes to an early acting, renoprotective injury response, modifying immune cell actions. The data support further investigation in clinical model systems of the potential benefit from GDF15 administration in situations in which some level of tubular injury is inevitable, such as following a kidney transplant.

Appraising growth differentiation factor 15 as a promising biomarker in digestive system tumors: a meta-analysis

Background

Previous studies have highlighted cytokine growth differentiation factor 15 (GDF-15) as a potential biomarker for digestive system tumors (DST). This study sought to assess the feasibility of using GDF-15 as a diagnostic and prognostic biomarker in DST.

Methods

Eligible studies from multiple online databases were reviewed. Meta-analyses of diagnostic parameters were carried out using standard statistical methods. Study-specific hazard ratios (HRs) with 95% confidence intervals (CIs) were calculated to estimate the strength of the relationship between GDF-15 levels and clinical prognosis.

Results

We identified 17 eligible studies comprising 3966 patients with DST. The sensitivity, specificity, and area under the curve (AUC) for the discriminative performance of GDF-15 as a diagnostic biomarker were 0.74 (95% CI: 0.68–0.80), 0.83 (95% CI: 0.75–0.89), and 0.84, respectively. Moreover, increased GDF-15 expression levels were markedly associated with unfavorable overall survival (OS) in patients with DST (HR = 2.34, 95% CI: 2.03–2.70, P < 0.001; I² = 0.0%) and colorectal cancer (CRC) (HR = 2.27, 95% CI: 1.96–2.63, P < 0.001; I² = 0.0%). Stratification by cancer type, test matrix, ethnicity, and cut-off setting also illustrated the robustness of the diagnostic value of GDF-15 in DST.

Conclusion

Collectively, our data suggest that GDF-15 expression level may have value as a diagnostic and prognostic biomarker, independent of other, traditional biomarkers.

Electronic supplementary material

The online version of this article (10.1186/s12885-019-5385-y) contains supplementary material, which is available to authorized users.

Targeting Crosstalk between Nrf-2, NF-κB and Androgen Receptor Signaling in Prostate Cancer

Oxidative stress, inflammation and androgen receptor (AR) signaling play a pivotal role in the initiation, development and progression of prostate cancer (PCa). Numerous papers in the literature have documented the interconnection between oxidative stress and inflammation; and how antioxidants can combat the inflammation. It has been shown in the literature that both oxidative stress and inflammation regulate AR, the key receptor involved in the transition of PCa to castration resistant prostate cancer (CRPC). In this review, we discuss about the importance of targeting Nrf-2-antioxidant signaling, NF-κB inflammatory response and AR signaling in PCa. Finally, we discuss about the crosstalk between these three critical pathways as well as how the anti-inflammatory antioxidant phytochemicals like sulforaphane (SFN) and curcumin (CUR), which can also target AR, can be ideal candidates in the chemoprevention of PCa.

A novel serum based biomarker panel has complementary ability to preclude presence of early lung cancer for low dose CT (LDCT)

Low Dosage Computerized Tomography (LDCT) has been shown to improve early detection of lung cancer and mortality rates in high-risk individuals, which was, however, limited by specifically coverage for heavy smokers and high rates of false positivity. Here, we aim to investigate a novel biomarker for early detection of lung cancer, and further extend to concentrate high-risk subjects for increasing specificity and coverage of LDCT. We performed retrospective blinded evaluation of lung cancer and healthy controls in training and validation cohorts. Macrophage inhibitory cytokine 1 (MIC-1) alone and panel were assessed. Our data showed the sensitivity of MIC-1 was 72.2% and 67.1% for lung cancer diagnosis and early diagnosis respectively, at 96.6% specificity, which were significantly higher than Cyfra21-1, NSE CA125, CEA and SCC. At 90% specificity, the panel of MIC-1, Cyfra21-1, CA125 and CEA provided 89.5% sensitivity for early diagnosis of lung cancer, which could be used to concentrate the high-risk subjects for further LDCT screening. We conclude that MIC-1 have great capacity in early lung cancer diagnosis. The algorithmic panel of MIC-1, Cyfra21-1, CA125 and CEA could be used to refine the preselection criteria of high-risk subjects, and thus might facilitate the widespread implementation of LDCT screening.

Elevated serum growth differentiation factor 15 levels are associated with thyroid nodules in type 2 diabetes aged over 60 years

In order to investigate whether serum growth differentiation factor 15 is associated with thyroid nodules in type 2 diabetes. We recruited 723 type 2 diabetic patients aged over 30 years who attended the clinic of Endocrinology of Xinhua Hospital from January 2013 to January 2015. Thyroid nodule was diagnosed by thyroid ultrasonographic examination. Serum growth differentiation factor 15, thyroid function, thyroid autoantibodies, thyroglobulin and other biochemical indicators were measured and compared between thyroid nodule positive and negative groups. We found that overall, serum growth differentiation factor 15 levels were significantly higher in subjects with thyroid nodules compared with nodule negative subjects (181.76±98.49 pg/ml vs. 162.32±83.63 pg/ml, p<0.05), and this was influenced by age. In the patients over 60 years, this difference became more significant (211.23±103.66 pg/ml vs. 177.38±85.51 pg/ml, p<0.01), but in patients under 60 years, there was no difference between the two groups. Multivariate logistic regression analysis showed that serum growth differentiation factor 15 levels were independently associated with thyroid nodule in diabetic patients over 60 years (P <0.001). After multiple adjustments, the odds ratios were substantially higher for thyroid nodule (odds ratio 2.63, 95% confidence interval 1.30-5.13, p<0.01) in the highest growth differentiation factor 15 quartile compared to those in the lowest quartile in patients over 60 years. In conclusion, serum growth differentiation factor 15 is increased significantly in subjects with thyroid nodules in type 2 diabetic patients aged over 60 years.

Specific expression pattern of tissue cytokines analyzed through the Surface Acoustic Wave technique is associated with age-related spontaneous benign prostatic hyperplasia in rats

The aim of the study reported herein was to evaluate the suitability of the Surface Acoustic Wave (SAW) technique as a possible diagnostic tool in benign prostatic hyperplasia (BPH). Moreover, for the first time, the BPH model was a totally physiological using naturally aged rats with spontaneous, age-related BPH instead of the pharmacologically induced models usually used. Eighteen male Wistar rats were distributed according to their age: 6 weeks (young), 12 weeks (adult) and 12 months (old) old. Prostate gland was removed and analyzed by mini-arrays, Western blotting (WB) and SAW techniques. Mini-arrays indicated that there were significant differences in the expression of 29/34 inflammation-related cytokines. WB was carried out to confirm the results after selection of 4 cytokines from which one showed no changes, namely PDGF-AA, and the other three, which significantly increase in older animals, were CD86, β-NGF and VEGF. Notwithstanding, WB of old rats yielded confusing results due to an anomalous migration of proteins, dismissing this technique as an useful tool in these animals. Accurate results in old rats were uniquely obtained by using the SAW technique. Thus, SAW analysis showed that there were not differences among groups in the amount of PDGF-AA. On the contrary, SAW analysis showed that amounts of CD86, β-NGF and VEGF in old rats were 2.0, 1.9 and 5.7-fold higher than that from young ones, respectively. These results indicate that SAW is a highly accurate technique for determining changes in the cytokines expression in BPH.

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Diagnosis of prostate alterations can be improved by using the SAW technique.

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Study of prostate alterations can be optimized by using an age-related animal model.

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VEGF is a sensitive marker of bening prostatic hyperplasia.

Linking Race, Cancer Outcomes, and Tissue Repair

The burden of cancer in the United States is unevenly spread across its different populations, with stark differences in both disease prevalence and outcome on the basis of race and ethnicity. Although a large portion of these differences can be explained by a variety of sociobehavioral and socioeconomic factors, even after these exposures are taken into consideration, considerable disparities persist. In this review, we explore a conceptual framework of biological theories and unifying concepts, based on an evolutionary perspective, that may help better define common guiding principles for exploration of underlying causes of cancer health disparities. The ultimate goal of this conceptual perspective is to outline approaches that may aid in establishing integrated pathway and processes analyses to provide useful insights to guide the development of future interventions. These interventions will improve outcome, increase prevention, and ultimately eliminate all disparities.

Angiogenesis enhanced by treatment damage to hepatocellular carcinoma through the release of GDF15

Transarterial chemoembolization (TACE) is the standard treatment for unresectable hepatocellular carcinoma (HCC). Hypoxia‐induced angiogenesis by TACE is linked to treatment failure; however, whether the chemotherapeutic damage of TACE to HCC could increase tumor angiogenesis has not been explored. The molecular effects of chemotherapy‐damaged HCC cells on the neo‐angiogenesis were investigated in vitro and in vivo. The expression of growth differentiation factor 15 (GDF15) was significantly upregulated in HCC cells exposed to chemotherapeutic agents. GDF15 from chemotherapy‐damaged HCC cells promoted the in vitro proliferation, migration, and tube formation of endothelial cells. The pro‐angiogenic effect of GDF15 was through the activation of Src and its downstream AKT, MAPK, and NF‐κB signaling, which was blocked by thalidomide. The use of thalidomide significantly attenuated the in vivo chemotherapy‐damaged HCC cells‐promoted angiogenesis in nude mice. In conclusion, the chemotherapeutic damage in TACE to HCC could promote tumor angiogenesis via the increased release of GDF15. Thalidomide could reverse these pro‐angiogenic effects.

Growth differentiation factor 15 is associated with left atrial/left atrial appendage thrombus in patients with nonvalvular atrial fibrillation

BACKGROUND

There is evidence suggesting that growth differentiation factor 15 (GDF-15) appears to be associated with stroke in patients with atrial fibrillation (AF). AF-related thromboembolic stroke is predominantly attributed to the thrombus from the left atrium (LA) or left atrial appendage (LAA).

HYPOTHESIS

GDF-15 is related to LA/LAA thrombus in nonvalvular AF (NVAF) patients.

METHODS

A total of 894 patients with NVAF without anticoagulation therapy were included in this study. All patients routinely underwent transesophageal echocardiography for detection of LA/LAA thrombus. GDF-15 was measured by enzyme-linked immunosorbent assay. Logistic regression models were used to test for association.

RESULTS

LA/LAA thrombus was detected by transesophageal echocardiography in 69 (7.72%) patients with AF. The GDF-15 levels in the patients with LA/LAA thrombus were significantly higher than those without LA/LAA thrombus (log₁₀ GDF-15: 2.989 ± 0.023 ng/L vs 2.831 ± 0.007 ng/L; P < 0.001). Logistic regression analysis showed that GDF-15 was an independent risk factor for LA/LAA thrombus (odds ratio [per quarter]: 1.799, 95% confidence interval: 1.381-2.344, P < 0.001) after adjusting for potential clinical risk factors. The optimal cutoff point for GDF-15 predicting LA/LAA thrombus was 809.9 ng/L (sensitivity, 75.3%; specificity, 61.5%), determined by ROC curve. The area under the curve was 0.709 (95% confidence interval: 0.644-0.770, P < 0.001).

CONCLUSIONS

Elevated GDF-15 indicated a significantly increased risk for LA/LAA thrombus in NVAF patients. Thus, GDF-15 might be a potentially useful adjunct in discriminating LA/LAA thrombus in NVAF patients.

Relevance of MIC-1 in the Era of PSA as a Serum Based Predictor of Prostate Cancer: A Critical Evaluation

To reduce the ambiguity of contradictory observations in different studies regarding the expression level of Macrophage Inhibitory Cytokine-1 (MIC-1) in serum in prostate cancer (PC), benign prostatic hyperplasia (BPH) and healthy controls (HC), we designed this double-blind study. The study comprises 240 sera from PC, BPH and HC subjects. The expression level of MIC-1 in PC, BPH and HC were appraised using Western blot (WB) and ELISA based approach. WB and ELISA appraisal reveals that the expression level of MIC-1 is significantly higher in PC than in HC or BPH subjects. Regression analysis revealed a significant correlation between MIC-1 vs. PSA (r = 0.09; p < 0.001) and MIC-1 vs. GS (r = 0.7; p < 0.001). ROC analysis using discriminant predicted probability revealed that the MIC-1 was better than PSA. Moreover, the combination of MIC-1 and PSA was allowing 99.1% AUC for the differentiation of BPH + PC from HC, 97.9% AUC for differentiation of BPH from HC, 98.6% AUC for differentiation of PC from HC, and 96.7% AUC for the differentiation of PC from BPH. The augmented expression of MIC-1 in PC compared to BPH and HC subjects is in concurrent of the over-expression of MIC-1 in PC reports and confiscates the contradictory findings of other studies.

Cancer and inflammation

The relationship between inflammation and cancer has been recognized since the 17^th century,¹ and we now know much about the cells, cytokines and physiological processes that are central to both inflammation and cancer.^2-9 Chronic inflammation can induce certain cancers,^10-17 and solid tumors, in turn, can initiate and perpetuate local inflammatory processes that foster tumor growth and dissemination.⁵ ,^18-20 Consequently, inflammatory pathways have been targeted in attempts to control cancer.^21-23 Inflammation is a central aspect of the innate immune system's response to tissue damage or infection, and also facilitates the recruitment of circulating cells and antibodies of the adaptive immune response to the tissue. Components of the innate immune response carry out a robust, but sometimes overly-conservative response, sacrificing specificity for the sake of preservation. Thus, when innate immunity goes awry, it can have profound implications. How the innate and adaptive immune systems cooperate to neutralize pathogens and repair damaged tissues is still an area of intense investigation. Further, how these systems can respond to cancer, which arises from normal 'self' cells that undergo an oncogenic transformation, has profound implications for cancer therapy. Recently, immunotherapies that activate adaptive immunity have shown unprecedented promise in the clinic, producing durable responses and dramatic increases in survival rate in patients with advanced stage melanoma.^24-26 Consequently, the relationship between cancer and inflammation has now returned to the forefront of clinical oncology. WIREs Syst Biol Med 2017, 9:e1370. doi: 10.1002/wsbm.1370 For further resources related to this article, please visit the WIREs website.

Association and regulation of protein factors of field effect in prostate tissues

Field effect or field cancerization denotes the presence of molecular aberrations in structurally intact cells residing in histologically normal tissues adjacent to solid tumors. Currently, the etiology of prostate field‑effect formation is unknown and there is a prominent lack of knowledge of the underlying cellular and molecular pathways. We have previously identified an upregulated expression of several protein factors representative of prostate field effect, i.e., early growth response-1 (EGR‑1), platelet-derived growth factor‑A (PDGF‑A), macrophage inhibitory cytokine‑1 (MIC‑1), and fatty acid synthase (FASN) in tissues at a distance of 1 cm from the visible margin of intracapsule prostate adenocarcinomas. We have hypothesized that the transcription factor EGR‑1 could be a key regulator of prostate field‑effect formation by controlling the expression of PDGF‑A, MIC‑1, and FASN. Taking advantage of our extensive quantitative immunofluorescence data specific for EGR‑1, PDGF‑A, MIC‑1, and FASN generated in disease‑free, tumor‑adjacent, and cancerous human prostate tissues, we chose comprehensive correlation as our major approach to test this hypothesis. Despite the static nature and sample heterogeneity of association studies, we show here that sophisticated data generation, such as by spectral image acquisition, linear unmixing, and digital quantitative imaging, can provide meaningful indications of molecular regulations in a physiologically relevant in situ environment. Our data suggest that EGR‑1 acts as a key regulator of prostate field effect through induction of pro‑proliferative (PDGF‑A and FASN), and suppression of pro‑apoptotic (MIC‑1) factors. These findings were corroborated by computational promoter analyses and cell transfection experiments in non‑cancerous prostate epithelial cells with ectopically induced and suppressed EGR‑1 expression. Among several clinical applications, a detailed knowledge of pathways of field effect may lead to the development of targeted intervention strategies preventing progression from pre-malignancy to cancer.

Linking obesogenic dysregulation to prostate cancer progression

The global epidemic of obesity is closely linked to the development of serious co-morbidities, including many forms of cancer. Epidemiological evidence consistently shows that obesity is associated with a similar or mildly increased incidence of prostate cancer but, more prominently, an increased risk for aggressive prostate cancer and prostate cancer-specific mortality. Studies in mice demonstrate that obesity induced by high-fat feeding increases prostate cancer progression; however, the mechanisms underpinning this relationship remain incompletely understood. Adipose tissue expansion in obesity leads to local tissue dysfunction and is associated with low-grade inflammation, alterations in endocrine function and changes in lipolysis that result in increased delivery of fatty acids to tissues of the body. The human prostate gland is covered anteriorly by the prominent peri-prostatic adipose tissue and laterally by smaller adipose tissue depots that lie directly adjacent to the prostatic surface. We discuss how the close association between dysfunctional adipose tissue and prostate epithelial cells might result in bi-directional communication to cause increased prostate cancer aggressiveness and progression. However, the literature indicates that several 'mainstream' hypotheses regarding obesity-related drivers of prostate cancer progression are not yet supported by a solid evidence base and, in particular, are not supported by experiments using human tissue. Understanding the links between obesity and prostate cancer will have major implications for the health policy for men with prostate cancer and the development of new therapeutic or preventative strategies.

The impact of obesity towards prostate diseases

Evidence has supported obesity as a risk factor for both benign prostate hyperplasia (BPH) and prostate cancer (PCa). Obesity causes several mechanisms including increased intra-abdominal pressure, altered endocrine status, increased sympathetic nervous activity, increased inflammation process, and oxidative stress, all of which are favorable in the development of BPH. In PCa, there are several different mechanisms, such as decreased serum testosterone, peripheral aromatization of androgens, insulin resistance, and altered adipokine secretion caused by inflammation, which may precipitate the development of and even cause high-grade PCa. The role of obesity in prostatitis still remains unclear. A greater understanding of the pathogenesis of prostate disease and adiposity could allow the development of new therapeutic markers, prognostic indicators, and drug targets. This review was made to help better understanding of the association between central obesity and prostate diseases, such as prostatitis, BPH, and PCa.

Prostate field cancerization: deregulated expression of macrophage inhibitory cytokine 1 (MIC-1) and platelet derived growth factor A (PDGF-A) in tumor adjacent tissue

Prostate field cancerization denotes molecular alterations in histologically normal tissues adjacent to tumors. Such alterations include deregulated protein expression, as we have previously shown for the key transcription factor early growth response 1 (EGR-1) and the lipogenic enzyme fatty acid synthase (FAS). Here we add the two secreted factors macrophage inhibitory cytokine 1 (MIC-1) and platelet derived growth factor A (PDGF-A) to the growing list of protein markers of prostate field cancerization. Expression of MIC-1 and PDGF-A was measured quantitatively by immunofluorescence and comprehensively analyzed using two methods of signal capture and several groupings of data generated in human cancerous (n = 25), histologically normal adjacent (n = 22), and disease-free (n = 6) prostate tissues. A total of 208 digitized images were analyzed. MIC-1 and PDGF-A expression in tumor tissues were elevated 7.1x to 23.4x and 1.7x to 3.7x compared to disease-free tissues, respectively (p<0.0001 to p = 0.08 and p<0.01 to p = 0.23, respectively). In support of field cancerization, MIC-1 and PDGF-A expression in adjacent tissues were elevated 7.4x to 38.4x and 1.4x to 2.7x, respectively (p<0.0001 to p<0.05 and p<0.05 to p = 0.51, respectively). Also, MIC-1 and PDGF-A expression were similar in tumor and adjacent tissues (0.3x to 1.0x; p<0.001 to p = 0.98 for MIC-1; 0.9x to 2.6x; p<0.01 to p = 1.00 for PDGF-A). All analyses indicated a high level of inter- and intra-tissue heterogeneity across all types of tissues (mean coefficient of variation of 86.0%). Our data shows that MIC-1 and PDGF-A expression is elevated in both prostate tumors and structurally intact adjacent tissues when compared to disease-free specimens, defining field cancerization. These secreted factors could promote tumorigenesis in histologically normal tissues and lead to tumor multifocality. Among several clinical applications, they could also be exploited as indicators of disease in false negative biopsies, identify areas of repeat biopsy, and add molecular information to surgical margins.

Local and systemic protumorigenic effects of cancer-associated fibroblast-derived GDF15

The tumor stroma is vital to tumor development, progression, and metastasis. Cancer-associated fibroblasts (CAF) are among the abundant cell types in the tumor stroma, but the range of their contributions to cancer pathogenicity has yet to be fully understood. Here, we report a critical role for upregulation of the TGFβ/BMP family member GDF15 (MIC-1) in tumor stroma. GDF15 was found upregulated in situ and in primary cultures of CAF from prostate cancer. Ectopic expression of GDF15 in fibroblasts produced prominent paracrine effects on prostate cancer cell migration, invasion, and tumor growth. Notably, GDF15-expressing fibroblasts exerted systemic in vivo effects on the outgrowth of distant and otherwise indolent prostate cancer cells. Our findings identify tumor stromal cells as a novel source of GDF15 in human prostate cancer and illustrate a systemic mechanism of cancer progression driven by the tumor microenvironment. Further, they provide a functional basis to understand GDF15 as a biomarker of poor prognosis and a candidate therapeutic target in prostate cancer.

Regulation of hepcidin through GDF-15 in cancer-related anemia

BACKGROUND

High prevalence and unresponsiveness to erythropoiesis-stimulating agents are 2 major limitations to the treatment of cancer-related anemia (CRA). They are often related to the dis-regulation of iron metabolism regulated by hepcidin, but the regulatory pathway of hepcidin in CRA is poorly understood. Enhanced GDF-15 levels contribute to the cancer progression and metastasis, and also have been found to suppress hepcidin expression in anemia characterized by ineffective erythropoiesis. The pathophysiological mechanisms and the relationship of GDF-15 and hepcidin in CRA remain to be elucidated.

METHODS

The concentrations of hepcidin and GDF-15 as well as the hematological and the iron parameters were determined in sera from 131 patients with cancer and 40 healthy controls.

RESULTS

Serum GDF-15 levels were increased significantly in patients with the severe CRA, compared with the mild or no CRA patients and the controls. Increasing GDF-15 levels corresponded to decreasing hepcidin concentrations. A trend toward a correlation between high levels of GDF-15 and poor prognosis of cancer was also found. Elevation of GDF-15 concentrations suppressed hepcidin expression at high concentrations.

CONCLUSIONS

Our findings suggest that tumor progression results in increased GDF-15 secretion, which may down-regulate hepcidin expression, resulting in iron overload in cancer patients; this phenomenon has also been found in some patients with sideropenic anemia due to chronic blood loss.

The role of inflammation in prostate cancer

In the United States and in "Westernized" countries, the prevalence of both prostate cancer and prostate inflammation is very high, indicating that the two pathologies could be causally related. Indeed, chronic inflammation is now regarded as an "enabling" characteristic of human cancer. Prostate cancer incidence is thought to be mediated in part by genetics, but also by environmental exposures, including the same exposures that may contribute to the development of prostatic inflammation. As our understanding of the role of inflammation in cancer deepens, it is increasingly apparent that "inflammation" as a whole is a complex entity that does not always play a negative role in cancer etiology. In fact, inflammation can play potentially dichotomous (both pro and antitumorigenic) roles depending on the nature and the cellular makeup of the immune response. This chapter will focus on reviewing the current state of knowledge on the role of innate and adaptive immune cells within the prostate tumor microenvironment and their seemingly complex role in prostate cancer in preventing versus promoting initiation and progression of the disease.

Prostate cancer and inflammation: the evidence

Chronic inflammation is now known to contribute to several forms of human cancer, with an estimated 20% of adult cancers attributable to chronic inflammatory conditions caused by infectious agents, chronic non-infectious inflammatory diseases and/or other environmental factors. Indeed, chronic inflammation is now regarded as an 'enabling characteristic' of human cancer. The aim of this review is to summarize the current literature on the evidence for a role for chronic inflammation in prostate cancer aetiology, with a specific focus on recent advances regarding the following: (i) potential stimuli for prostatic inflammation; (ii) prostate cancer immunobiology; (iii) inflammatory pathways and cytokines in prostate cancer risk and development; (iv) proliferative inflammatory atrophy (PIA) as a risk factor lesion to prostate cancer development; and (v) the role of nutritional or other anti-inflammatory compounds in reducing prostate cancer risk.

Regulating inflammation: ADAM8--a new player in the game

Leukocyte recruitment to sites of inflammation proceeds in a cascade-like fashion. However, it is less clear how the complex interactions among the different adhesion molecules involved in this process are coordinately regulated. A report in this issue of the European Journal of Immunology [Eur. J. Immunol. 2011. 41: 3436-3442] shows that ADAM8 may participate in the control of the adhesion molecule P-selectin glycoprotein ligand 1. This finding suggests a new role for ADAM8 in the regulation of inflammatory processes.

Positive regulation of osteoclastic differentiation by growth differentiation factor 15 upregulated in osteocytic cells under hypoxia

Osteocytes are thought to play a role as a mechanical sensor through their communication network in bone. Although osteocytes are the most abundant cells in bone, little attention has been paid to their physiological and pathological functions in skeletogenesis. Here, we have attempted to delineate the pivotal functional role of osteocytes in regulation of bone remodeling under pathological conditions. We first found markedly increased osteoclastic differentiation by conditioned media (CM) from osteocytic MLO-Y4 cells previously exposed to hypoxia in vitro. Using microarray and real-time PCR analyses, we identified growth differentiation factor 15 (GDF15) as a key candidate factor secreted from osteocytes under hypoxia. Recombinant GDF15 significantly promoted osteoclastic differentiation in a concentration-dependent manner, with concomitant facilitation of phosphorylation of both p65 and inhibitory-κB in the presence of receptor activator of nuclear factor-κB ligand. To examine the possible functional significance of GDF15 in vivo, mice were subjected to ligation of the right femoral artery as a hypoxic model. A significant increase in GDF15 expression was specifically observed in tibias of the ligated limb but not in tibias of the normally perfused limb. Under these experimental conditions, in cancellous bone of proximal tibias in the ligated limb, a significant reduction was observed in bone volume, whereas a significant increase was seen in the extent of osteoclast surface/bone surface when determined by bone histomorphometric analysis. Finally, the anti-GDF15 antibody prevented bone loss through inhibiting osteoclastic activation in tibias from mice with femoral artery ligation in vivo, in addition to suppressing osteoclastic activity enhanced by CM from osteocytes exposed to hypoxia in vitro. These findings suggest that GDF15 could play a pivotal role in the pathogenesis of bone loss relevant to hypoxia through promotion of osteoclastogenesis after secretion from adjacent osteocytes during disuse and/or ischemia in bone.

Promiscuity and specificity in BMP receptor activation

Bone Morphogenetic Proteins (BMPs), together with Transforming Growth Factor (TGF)-β and Activins/Inhibins constitute the TGF-β superfamily of ligands. This superfamily is formed by more than 30 structurally related secreted proteins. Since TGF-β members act as morphogens, either a strict relation between a particular ligand to a distinct cellular receptor and/or temporospatial expression patterns of ligands and receptors is expected. Instead, only a limited number of receptors exist implicating promiscuous interactions of ligands and receptors. Furthermore, in complex tissues a multitude of different ligands can be found, which signal via overlapping subsets of receptors. This raises the intriguing question how concerted interactions of different ligands and receptors generate highly specific cellular signals, which are required during development and tissue homeostasis.

Inflammation-associated regulation of the macrophage inhibitory cytokine (MIC-1) gene in prostate cancer

Macrophage inhibitory cytokine-1 (MIC-1), also known as prostate-derived factor (PDF), is a molecule of the TGF-β superfamily and has been associated with the progression of various types of diseases including prostate cancer. Initially identified from activated macrophages, the MIC-1 gene may provide a potential link between inflammation and prostate cancer. In this context, we performed MIC-1 expression analysis using mouse prostate tissues to determine whether there was any correlation with age and inflammation. Reverse transcription PCR analysis on RNA samples isolated from prostate lobes from prostate-specific antigen transgenic mice of varying ages revealed that MIC-1 gene expression is extremely low to non-detectable in the prostate tissues obtained from young mice, while its expression increases in the prostate tissues harvested from elderly mice. Increased MIC-1 gene expression in the mouse prostate was found to be associated with an increased level of infiltrating lymphocytes. To confirm this observation, we showed that inflammation-associated cytokines (IL-1β and TNF-α) significantly upregulate the secretion of the MIC-1 protein in a human prostate cancer cell line (LNCaP cells), while cytokines IL-6 and granulocyte macrophage colony-stimulating factor were less effective. Taken together, these data indicated that inflammation-associated cytokines may play a critical role in the functional regulation of the MIC-1 gene in the early stages of prostate cancer development. More studies are required to understand the biological activity of MIC-1 gene regulation in the development and progression of prostate cancer.

Gene expression signatures differ with extent of atherosclerosis in monkey iliac artery

OBJECTIVE

The aim of this study was to evaluate global gene expression patterns in the common iliac arteries of monkeys with a varied extent of atherosclerosis.

METHODS

The left common iliac artery was removed from ovariectomized cynomolgus monkeys (n = 12) after 6.5 years of consuming a diet containing fat and cholesterol at levels comparable with those consumed in Western populations. Arterial gene expression was analyzed using DNA microarray and real-time reverse transcription-polymerase chain reaction.

RESULTS

Significant differential expression of 986 genes was observed in iliac arteries containing moderate to large atherosclerotic plaques compared with normal/minimally affected reference group arteries. Atherosclerosis-associated genes included cytokines, chemokines, components of signal transduction pathways, and transcriptional activators and repressors, as well as other functional categories. Real-time reverse transcription-polymerase chain reaction confirmed a differential expression of genes chosen from a variety of functional categories. Specifically, the expression of genes for estrogen receptor-1, claudin 11, and brain heart protocadherin 7 was reduced, whereas the expression of genes for apolipoprotein E, growth differentiation factor 15, superoxide dismutase-2, SET domain bifurcated 2, phospholipase A2 group IIA, phospholipase A2 group VII, and ring finger protein 149 was increased in atherosclerotic arteries.

CONCLUSIONS

The gene expression environment in arteries containing atherosclerotic plaques is profoundly different from that of relatively unaffected arteries and reflects the cellular and molecular complexity of atherosclerosis and associated arterial remodeling processes.

Wild-type p53 attenuates cancer cell motility by inducing growth differentiation factor-15 expression

A major function of the p53 tumor suppressor is the regulation of the cell cycle and apoptosis. In addition to its well-documented functions in malignant cancer cells, p53 can also regulate cell migration and invasion, which contribute to metastasis. Growth differentiation factor-15 (GDF-15), a member of the TGF-β superfamily, has been shown to be a downstream target of p53 and is associated with diverse human diseases and cancer progression. In this study, we examined the potential role of GDF-15 in p53-regulated cancer cell motility. We show that overexpression of wild-type p53 in two highly invasive p53-null human cancer cell lines, SKOV3 and PC3, attenuated cell migration and the movement through Matrigel. Using wild-type p53 and DNA-binding-deficient p53 mutants, we found that the transcriptional activity of p53 is required in the induction of GDF-15 expression. Cell movement through uncoated and Matrigel-coated transwell decreased in response to treatment with recombinant GDF-15, whereas the cell proliferation was not affected by GDF-15 treatment. Moreover, the induction of GDF-15 expression and secretion by p53 and the reduction in cell movement through Matrigel were diminished by treatment with GDF-15 small interfering RNA. This study demonstrates a mechanism by which p53 attenuates cancer cell motility through GDF-15 expression. In addition, our results indicate that GDF-15 mediates the functions of p53 by autocrine/paracrine action.

Bevacizumab in metastatic breast cancer: when may it be used?

Tumor angiogenesis, which is necessary for breast cancer growth, invasion and metastases, is regulated by pro-angiogenic factors such as vascular endothelial growth factor (VEGF). Bevacizumab is a recombinant humanized monoclonal antibody that targets VEGF. The addition of bevacizumab to chemotherapy has improved progression-free survival in the first- and second-line treatment of patients with advanced-stage breast cancer. In this article we review the clinical trials testing the utility of bevacizumab for the treatment of metastatic disease.

The relationship between insulin resistance and the cardiovascular biomarker growth differentiation factor-15 in obese patients

BACKGROUND

Growth differentiation factor-15 (GDF-15) is a stress-responsive cytokine linked to obesity comorbidities such as cardiovascular disease, inflammation, and cancer. GDF-15 also has adipokine properties and recently emerged as a prognostic biomarker for cardiovascular events.

METHODS

We evaluated the relationship of plasma GDF-15 concentrations with parameters of obesity, inflammation, and glucose and lipid metabolism in a cohort of 118 morbidly obese patients [mean (SD) age 37.2 (12) years, 89 females, 29 males] and 30 age- and sex-matched healthy lean individuals. All study participants underwent a 75-g oral glucose tolerance test; 28 patients were studied before and 1 year after Roux-en-Y gastric bypass surgery.

RESULTS

Obese individuals displayed increased plasma GDF-15 concentrations (P < 0.001), with highest concentrations observed in patients with type 2 diabetes. GDF-15 was positively correlated with age, waist-to-height ratio, mean arterial blood pressure, triglycerides, creatinine, glucose, insulin, C-peptide, hemoglobin A(1c), and homeostatic model assessment insulin resistance index and negatively correlated with oral glucose insulin sensitivity. Age, homeostatic model assessment index, oral glucose insulin sensitivity, and creatinine were independent predictors of GDF-15 concentrations. Roux-en-Y gastric bypass led to a significant reduction in weight, leptin, insulin, and insulin resistance, but further increased GDF-15 concentrations (P < 0.001).

CONCLUSIONS

The associations between circulating GDF-15 concentrations and age, insulin resistance, and creatinine might account for the additional cardiovascular predictive information of GDF-15 compared to traditional risk factors. Nevertheless, GDF-15 changes following bariatric surgery suggest an indirect relationship between GDF-15 and insulin resistance. The clinical utility of GDF-15 as a biomarker might be limited until the pathways directly controlling GDF-15 concentrations are better understood.

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.

Divergent molecular mechanisms underlying the pleiotropic functions of macrophage inhibitory cytokine-1 in cancer

Multifunctional macrophage inhibitory cytokine-1, MIC-1, is a member of the transforming growth factor-beta (TGF-beta) superfamily that plays key roles in the prenatal development and regulation of the cellular responses to stress signals and inflammation and tissue repair after acute injuries in adult life. The stringent control of the MIC-1 expression, secretion, and functions involves complex regulatory mechanisms and the interplay of other growth factor signaling networks that control the cell behavior. The deregulation of MIC-1 expression and signaling pathways has been associated with diverse human diseases and cancer progression. The MIC-1 expression levels substantially increase in cancer cells, serum, and/or cerebrospinal fluid during the progression of diverse human aggressive cancers, such as intracranial brain tumors, melanoma, and lung, gastrointestinal, pancreatic, colorectal, prostate, and breast epithelial cancers. Of clinical interest, an enhanced MIC-1 expression has been positively correlated with poor prognosis and patient survival. Secreted MIC-1 cytokine, like the TGF-beta prototypic member of the superfamily, may provide pleiotropic roles in the early and late stages of carcinogenesis. In particular, MIC-1 may contribute to the proliferation, migration, invasion, metastases, and treatment resistance of cancer cells as well as tumor-induced anorexia and weight loss in the late stages of cancer. Thus, secreted MIC-1 cytokine constitutes a new potential biomarker and therapeutic target of great clinical interest for the development of novel diagnostic and prognostic methods and/or cancer treatment against numerous metastatic, recurrent, and lethal cancers.

Genomic profiling of tumor initiating prostatospheres

Background

The cancer stem cell (CSC) hypothesis proposes that a population of tumor cells bearing stem cell properties is responsible for the origin and maintenance of tumors. Normal and cancer stem cells possess the ability to grow in vitro as self-renewing spheres, but the molecular basis of this phenotype remains largely unknown. We intended to establish a comprehensive culture system to grow prostatospheres (PSs) from both cancer cell lines and patient tumors. We then used gene expression microarrays to gain insight on the molecular pathways that sustain the PS tumor initiating cell (TIC) phenotype.

Results

Traditional stem cell medium (SCM) supplemented with Knockout™SR (KO) allows the propagation of monoclonal PSs from cell lines and primary cells. PSs display gene expression and tumorigenicity hallmarks of TICs. Gene expression analysis defined a gene signature composed of 66 genes that characterize LNCaP and patient PSs. This set includes novel prostate TIC growth factors (NRP1, GDF1, JAG1), proteins implicated in cell adhesion and cytoskeletal maintenance, transcriptional regulators (MYCBP, MYBL1, ID1, ID3, FOS, ELF3, ELF4, KLF2, KLF5) and factors involved in protein biosynthesis and metabolism. Meta-analysis in Oncomine reveals that some of these genes correlate with prostate cancer status and/or progression. Reporter genes and inhibitors indicate that the Notch pathway contributes to prostatosphere growth.

Conclusions

We have developed a model for the culture of PSs, and provide a genomic profile that support CSCs identity. This signature identifies novel markers and pathways that are predicted to correlate with prostate cancer evolution.

Organ transplantation and skin cancer: basic problems and new perspectives

Solid organ transplant and subsequent graft survival have increased worldwide, while immunosuppression has prevented rejection with increasing success. Side effects of cutaneous infection and neoplasm, however, affect the majority of solid organ transplant recipients (OTRs). Squamous cell carcinoma of the skin (SCC) is the most common neoplasm overall following organ transplant with a risk that is 60-100 times greater than for the immunocompetent population. This review focuses on questions of ongoing debate about SCC formation in OTRs such as viral carcinogenesis, systemic photoprotection, photosensitization by drugs, the impact of immunosuppressive drugs and inflammation as a driver of carcinogenesis.

Macrophage inhibitory cytokine-1 regulates melanoma vascular development

Expression of macrophage inhibitory cytokine-1 (MIC-1), a member of the transforming growth factor-beta family, normally increases during inflammation or organ injury. MIC-1 is also expressed at higher levels in melanomas; however, its role in tumorigenesis is unknown. This report identifies a novel function for MIC-1 in cancer. MIC-1 was overexpressed in approximately 67% of advanced melanomas, accompanied by fivefold to six-fold higher levels of secreted protein in serum of melanoma patients compared with normal individuals. Constitutively active mutant (V600E)B-Raf in melanoma regulated downstream MIC-1 expression. Indeed, small-interfering RNA-mediated targeting of MIC-1 or (V600E)B-Raf reduced expression and secretion by three-fold to fivefold. This decrease in MIC-1 levels reduced melanoma tumorigenesis by approximately threefold, but did not alter cultured cell growth, suggesting a unique function other than growth control. Instead, inhibition of MIC-1 was found to mechanistically retard melanoma tumor vascular development, subsequently affecting tumor cell proliferation and apoptosis. This role in melanoma angiogenesis was confirmed by comparing MIC-1 and vascular endothelial growth factor (VEGF) function in chick chorioallantoic membrane and matrigel plug assays. Similar to VEGF in melanomas, MIC-1 stimulated directional vessel development, acting as a potent angiogenic factor. Thus, MIC-1 is secreted from melanoma cells together with VEGF to promote vascular development mediated by (V600E)B-Raf signaling.

Synthesis, in vitro structure-activity relationship, and in vivo studies of 2-arylthiazolidine-4-carboxylic acid amides as anticancer agents

A series of (2RS,4R)-2-arylthiazolidine-4-carboxylic acid amide (ATCAA) was synthesized. Antiproliferative activity against melanoma and prostate cancer cells compared with control cells (fibroblast and RH7777, respectively) was evaluated. Compound 3id showed the best selectivity and growth-inhibition activity against three melanoma cell lines (B16-F1, A375, and WM-164). Compounds 15b and 3ac had good selectivity and potency against four prostate cancer cell lines (DU 145, PC-3, LNCaP, and PPC-1). The structure-activity relationship (SAR) of the side chain, the thiazolidine ring, and phenyl substituents is discussed. Cell cycle analysis showed that the percentage of cancer cells undergoing apoptosis (sub-G1 phase) increased after treatment with 1b and 3ad, which also strongly inhibited melanoma colony formation. In vivo studies on nude mice bearing A375 melanoma tumors showed that compound 1b inhibited tumor growth in a dose-dependent manner. At a dose of 10mg/kg, 1b significantly inhibited melanoma tumor growth and showed higher efficacy than did dacarbazine at 60mg/kg.