Colorectal cancer remains one of the most common and lethal malignancies worldwide despite the use of various therapeutic strategies. A better understanding of the mechanisms responsible for tumor initiation and progression is essential for the development of novel, more powerful therapies. The traditional, so-called "stochastic model" of tumor development, which assumes that each cancer cell is tumorigenic, has been deeply challenged during the past decade by the identification of cancer stem cells (CSCs), a biologically distinct subset of cells within the bulk of tumor mass. This discovery led to the development of the hierarchical model of tumorigenesis which assumes that only CSCs have the ability to initiate tumor growth, both at primary and metastatic sites. This model implies that the elimination of all CSCs is fundamental to eradicate tumors and that failure to do so might be responsible for the occurrence of relapses and/or metastases frequently observed in the clinical management of colorectal cancer patients. Identification and isolation of CSCs is essential for a better understanding of their role in the tumorigenetic process and for the development of CSC-specific therapies. Several methods have been used for this purpose and many efforts have been focused on the identification of specific CSC-surface markers. This review provides an overview of the proposed roles of CSC in human colorectal tumorigenesis focusing on the most important molecules identified as CSC-specific markers in colorectal cancer and on the potential strategies for the development of CSC-targeted therapy.

(2015) Laparoscopic surgery for colorectal cancer is not associated with an increase in the circulating levels of several inflammation-related factors, Cancer Biology & Therapy, 16:5,[671][672][673][674][675][676][677]

Mycobacteria display pro- and anti-inflammatory effects in human and experimental pathology. We show here that both effects are mediated by Toll-like receptor 2 (Tlr2), by exploiting a previously characterized Tlr2 variant (Met82Ile). Tlr2 82ile promoted self-specific proinflammatory polarization as well as expansion of ag-specific FoxP3+ Tregs, while Tlr2 82met impairs the expansion of Tregs and reduces the production of IFN-γ and IL-17 proinflammatory cytokines. Preferential dimerization with Tlr1 or Tlr6 could not explain these differences. In silico, we showed that Tlr2 variant Met82Ile modified the binding pocket for peptidoglycans and participated directly to a putative binding pocket for sugars and cadherins. The distinct pro- and anti-inflammatory actions impacted severity, extent of remission, and distribution of the lesions within the central nervous system of experimental autoimmune encephalomyelitis. Thus, Tlr2 has a janus function in vivo as mediator of the role of bacterial products in balancing pro- and anti-inflammatory immune responses.

BackgroundInformation currently available on the impact of palladium on the immune system mainly derives from studies assessing the biological effects of palladium salts. However, in the last years, there has been a notable increase in occupational and environmental levels of fine and ultrafine palladium particles released from automobile catalytic converters, which may play a role in palladium sensitization. In this context, the evaluation of the possible effects exerted by palladium nanoparticles (Pd-NPs) on the immune system is essential to comprehensively assess palladium immunotoxic potential.AimTherefore, the aim of this study was to investigate the effects of Pd-NPs on the immune system of female Wistar rats exposed to this xenobiotic for 14 days, by assessing possible quantitative changes in a number of cytokines: IL-1α, IL-2, IL-4, IL-6, IL-10, IL-12, GM-CSF, INF-γ and TNF-α.MethodsTwenty rats were randomly divided into four exposure groups and one of control. Animals were given a single tail vein injection of vehicle (control group) and different concentrations of Pd-NPs (0.012, 0.12, 1.2 and 12 μg/kg). A multiplex biometric enzyme linked immunosorbent assay was used to evaluate cytokine serum levels.ResultsThe mean serum concentrations of all cytokines decreased after the administration of 0.012 μg/kg of Pd-NPs, whereas exceeded the control levels at higher exposure doses. The highest concentration of Pd-NPs (12 μg/kg) induced a significant increase of IL-1α, IL-4, IL-6, IL-10, IL-12, GM-CSF and INF-γ compared to controls.Discussion and ConclusionsThese results demonstrated that Pd-NP exposure can affect the immune response of rats inducing a stimulatory action that becomes significant at the highest administered dose. Our findings did not show an imbalance between cytokines produced by CD4+ T helper (Th) cells 1 and 2, thus suggesting a generalized stimulation of the immune system with a simultaneous activation and polarization of the naïve T cells towards Th1 and Th2 phenotype.

Recent progresses in the understanding of facioscapulohumeral muscular dystrophy (FSHD) genetics opened the way to the development of targeted therapies. However, knowledge about pathophysiology of muscle damage is still limited and there is increasing need to identify biomarkers of disease activity in the perspective of clinical trial readiness.We analyzed inflammatory mediators in the interstitial fluid of muscles with different MRI signal in FSHD patients, comparing muscles displaying early lesions on short-tau inversion recovery (STIR) sequences with normal ones. Patients with one T1-weighted normal and STIR hyperintense (STIR+) and contralateral T1-weighted and STIR normal (STIR-) lower limb muscle were asked to enter the study. Twelve consecutive patients, five controls, and one non-penetrant gene carrier underwent prolonged muscle microdialysis with high cut-off membranes. Microdialysates were analyzed using xMAP technology with a wide panel for cytokines, chemokines, and growth factors. A small number of inflammatory mediators were dysregulated in STIR+ versus STIR- and control muscles: CXCL13, upregulated in STIR+ muscles compared with controls (p < 0.01); CXCL5, downregulated in STIR+ compared with STIR- muscles (p < 0.05); and G-CSF, downregulated in STIR+ muscles compared with controls (p < 0.05). CXCL13 was also upregulated in the STIR+ muscles compared with the contralateral STIR- muscles of the same patient (p < 0.01).These results support the evidence of a selective inflammatory process taking place in STIR+ FSHD muscles. The application of microdialysis could provide insights on novel mechanisms involved in muscle damage in FSHD and in other myopathies. Further studies are needed to validate these investigated molecules as tissue and circulating biomarkers.

Several in vitro assays have been proposed to identify cancer stem cells (CSCs), including immunophenotyping, sphere assay and side population (SP) assay. CD133 antigen has been proposed as a CSC marker in colon cancer (CC). However, no functional data are available to date and conflicting results have been reported regarding its role as true CSC marker. Here we set out to identify a molecular signature associated with potential CSC. CD133(+) cells isolated from the CaCo-2 CC cell line were analysed by microarray molecular profiling compared to CD133(-) counterparts. Various differentially expressed genes were identified and the most relevant transcripts found to be over-expressed in CD133(+) cells were evaluated by quantitative RT-PCR in the CD133(+) fractions isolated from several CC cell lines. In the attempt to find a correlation between putative CSCs, isolated by means of CD133 immunophenotyping and the SP approach, we demonstrated a significant enrichment of CD133(+) cells within the SP fraction of CC cells, and comparison of the gene expression profiles revealed that Endothelin-1 (END-1) and nuclear receptor subfamily 4, group A, member 2 (NR4A2) transcripts are highly expressed in both CD133(+) and SP fractions of CC cells. Moreover, depletion of CD133 by siRNA induced a significant attenuation of END-1 and NR4A2 expression levels in CaCo-2 cells, while expression of all three molecules decreased during sodium butyrate-induced differentiation. In conclusion, we have identified a molecular signature associated with potential CSCs and showed for the first time the existence of a functional relationship between CD133, END-1 and NR4A2 expression in colon cancer cells.

Recently, palladium nanoparticles (PdNPs) have been increasingly used in many industrial sectors, and this has led to a significant release of nano-sized palladium particles into the environment. However, despite the increase in occupational and general population exposure, information on the potential adverse effects of these PdNPs is still limited and their impact on the immune system constitutes a major health concern. Therefore, the aim of this study was to investigate the potential adverse effects induced by subchronic intravenous administration of PdNPs on the immune system of female Wistar rats by evaluating alterations in Interleukin (IL)-1α, IL-2, IL-4, IL-6, IL-10, IL-12, granulocyte-macrophage colony-stimulating factor (GM-CSF), Interferon (INF)-γ, and Tumor Necrosis Factor (TNF)-α serum levels. Exposed and control animals were randomly divided into five groups (0, 0.012, 0.12, 1.2, and 12 μg PdNPs per kg body weight) which were treated with repeated intravenous injections of vehicle or PdNPs (on day 1, 30, and 60). Subchronic exposure to PdNPs induced a decreasing trend in serum levels in most of the cytokines investigated, with the highest concentration (12 μg/kg) determining significant inhibitory effects. Overall, these results showed that PdNPs are able to alter cytokine serum levels in subchronically treated Wistar rats, suggesting a possible impact of these xenobiotics on the immune system after long-term exposures.

Altered immune responses have been reported in head and neck cancer, and some of these responses have been associated with poor clinical outcomes. A multiple-array technology platform was used to simultaneously evaluate the levels of 25 cytokines. Pre-treatment serum levels were evaluated in 31 HNSCC patients and 6 healthy controls. The levels of 8 cytokines, specifically IL-1ra, IL-2, IL-5, IL-6, IL-8, IL-17, IFN-γ and IP-10, were significantly higher in patients than in controls. Among cancer patients we observed lower levels of IFN-γ and IL-7 in cases with nodal metastases compared to those with cN0 disease. We observed increases in the levels of some serum cytokines in HNSCC patients, as well as reductions in selected cytokines associated with regional progression. These findings provide an intriguing perspective on the development and validation of novel markers for follow-up evaluations and predictions of regional spreading in HNSCC patients. KEY WORDS: Head and neck SCC • Nodal metastasis • Predictive factors • Cytokines • Inflammation • IFN-γ RIASSUNTOÈ noto che nelle neoplasie della testa e del collo vi siano delle alterazioni della risposta immune, ed alcune di tali alterazioni sono state associate ad un peggioramento prognostico. Abbiamo utilizzato una piattaforma con una tecnologia multi-array per valutare simultaneamente i valori di 25 citochine nel siero di 31 pazienti, affetti da carcinomi squamosi della testa e del collo prima del trattamento, e di 6 controlli sani. I livelli di 8 citochine