Interferon lambda-1 (IFN-l1/IL-29) is a member of the Type-III interferon family, which contains three ligands: IFN-l1, 2 and 3. These three ligands use the same unique heterodimeric receptor composed of CRF2-12 (IFN-l-R1/IL-28Ra) and CRF2-4 (IL10-R-b) chains. Like their close relatives, the Type-I interferons, IFN-l1, 2 and 3, promote the phosphorylation of STAT1 and STAT2, induce the ISRE3 complex, elevate OAS and MxA expression and exhibit antiviral activity in vitro. Their use of the IL10-R-b chain and their ability to phosphorylate STAT3, STAT4 and STAT5 suggested that they may also exhibit immunomodulatory activity; their antiviral action led us to hypothesize that this activity might be directed toward the Th1/Th2 system. Here, we have demonstrated that IFN-l1 altered the activity of Th cells in three separate experimental systems: (i) mitogen stimulation, (ii) mixed-lymphocyte reaction (MLR) and (iii) stimulation of naive T cells by monocyte-derived dendritic cells (mDC). In Con-A stimulation assays, the inclusion of IFN-l1 consistently led to markedly diminished levels of secreted interleukin (IL-13) with occasional coincident, modest elevation of secreted IFN-g. IL-13 secretion was 100-fold more sensitive to IFN-l1 than was IFN-g secretion. These observations were also made in the allogeneic two-way MLR. IFN-l1 was able to alter cytokine-mediated Th biasing and when naive T cells were exposed to allogeneic mDC that had been matured in the presence of IFN-l1, secreted IL-13 was again markedly and consistently reduced, whereas secreted IFN-g was largely unaltered. These functions were independent of IL-10. Our data support a hitherto unsuspected role for IFN-l1 in modulating the development of Th1 and Th2 cells, with an apparent emphasis on the diminution of IL-13 secretion.

The interferon lambda family (IFN-l1/2/3) is a newly described group of cytokines that are related to both the type-1 interferons and IL-10 family members. These novel cytokines are induced during viral infection and, like type-1 interferons, display significant anti-viral activity. In order to understand their function in more depth, we have examined the ability of IFN-l1/IL-29 to regulate cytokine production by human immune cells. Whole peripheral blood mononuclear cells (PBMC) exposed to IFN-l1 specifically upregulated IL-6, -8 and -10 but there were no visible effects on TNF or IL-1. This response was produced in a dose-dependant fashion and was inhibited by IL-10. Examination of purified cell populations isolated from PBMC demonstrated that monocytes, rather than lymphocytes, were the major IFN-l1-responsive cellular subset, producing IL-6, -8 and -10 in response to IFN-l1. Monocyte responses induced by low-level LPS stimulation were also synergistically enhanced by the presence of IFN-l1. Human macrophages were also shown to react to IFN-l1 similarly to monocytes, by producing the cytokines IL-6, -8 and -10. In conclusion, we have shown that IFN-l1, a cytokine produced in response to viral infection, activates both monocytes and macrophages producing a restricted panel of cytokines and may therefore be important in activating innate immune responses at the site of viral infection.

Colorectal cancer (CRC) is the third most common cancer in the world. A significant survival rate is achieved if it is detected at an early stage. A whole blood screening test, without any attempt to isolate blood fractions, could be an important tool to improve early detection of colorectal cancer. We searched for candidate markers with a novel approach based on the Transcriptome Mapper (TRAM), aimed at identifying specific RNAs with the highest differential expression ratio between colorectal cancer tissue and normal blood samples. This tool permits a large-scale systematic meta-analysis of all available data obtained by microarray experiments. The targeting of RNA took into consideration that tumour phenotypic variation is associated with changes in the mRNA levels of genes regulating or affecting this variation.A real time quantitative reverse transcription polymerase chain reaction (qRT- PCR) was applied to the validation of candidate markers in the blood of 67 patients and 67 healthy controls. The expression of genes: TSPAN8, LGALS4, COL1A2 and CEACAM6 resulted as being statistically different.In particular ROC curves attested for TSPAN8 an AUC of 0.751 with a sensitivity of 83.6% and a specificity of 58.2% at a cut off of 10.85, while the panel of the two best genes showed an AUC of 0.861 and a sensitivity of 92.5% with a specificity of 67.2%.Our preliminary study on a total of 134 subjects showed promising results for a blood screening test to be validated in a larger cohort with the staging stratification and in patients with other gastrointestinal diseases.

Epidermal Growth Factor Receptor (EGFR) activates a robust signalling network to which colon cancer tumours often become addicted. Cetuximab, one of the monoclonal antibodies targeting this pathway, is employed to treat patients with colorectal cancer. However, many patients are intrinsically refractory to this treatment, and those who respond develop secondary resistance along time. Mechanisms of cancer cell resistance include either acquisition of new mutations or non genomic activation of alternative signalling routes. In this study, we employed a colon cancer model to assess potential mechanisms driving resistance to cetuximab. Resistant cells displayed increased ability to grow in suspension as colonspheres and this phenotype was associated with poorly organized structures. Factors secreted from resistant cells were causally involved in sustaining resistance, indeed administration to parental cells of conditioned medium collected from resistant cells was sufficient to reduce cetuximab efficacy. Among secreted factors, we report herein that a signature of inflammatory cytokines, including IL1A, IL1B and IL8, which are produced following EGFR pathway activation, was associated with the acquisition of an unresponsive phenotype to cetuximab in vitro. This signature correlated with lack of response to EGFR targeting also in patient-derived tumour xenografts. Collectively, these results highlight the contribution of inflammatory cytokines to reduced sensitivity to EGFR blockade and suggest that inhibition of this panel of cytokines in combination with cetuximab might yield an effective treatment strategy for CRC patients refractory to anti-EGFR targeting.

The CELTiC panel could represent a useful tool for discriminating subjects with positive FIT findings and for the early detection of precancerous adenomatous lesions and CRC.

BackgroundThe ATP-binding cassette transporter B1 (ABCB1) gene codes for a membrane efflux pump localized in epithelial cells. Together with other Permeability-glycoproteins in the small and large intestine, its product represents a barrier against xenobiotics, bacterial toxins, drugs and other substances introduced with diet, including carcinogens. The aim of this investigation was to verify the possible contribution of ABCB1 single nucleotide polymorphisms (SNPs) to the genetic risk of colorectal cancer (CRC).ResultsDNA obtained from the peripheral blood of 98 CRC patients and 100 healthy controls was genotyped for the three selected SNPs: 1236C > T (rs1128503), 2677G > T/A (rs2032582), and 3435C > T (rs1045642). Molecular data were analyzed to asses allele and haplotype association with CRC.No evidence of an association between ABCB1 alleles and CRC occurrence as a whole was found. However, ABCB1 showed either association with carcinoma of the sigmoid colon, and appeared able to influence the sex ratio among CRC patients. These two effects seemed to act independently based on multivariate analysis. We showed that ABCB1 polymorphisms were able to influence CRC susceptibility related to tumor localization and patient gender.ConclusionsWe suggest that sensitivity to undetermined risk factors could depend on the genetic background of ABCB1 locus, with a mechanism that also depends on patient gender.Electronic supplementary materialThe online version of this article (doi:10.1186/s12929-014-0089-8) contains supplementary material, which is available to authorized users.

Aim: In view of accumulating evidence supporting a pivotal role of the Rho/ROCK pathway in cancer, we investigated Rho-kinase polymorphisms as potential susceptibility factors in colorectal cancer (CRC) in a representative sample of the Italian population. Methods: DNA obtained from the peripheral blood samples of 137 CRC patients and 141 healthy controls was genotyped for four ROCK1 (rs35996865; rs73963110; rs2127958; rs288980) and five ROCK2 (rs12692437; rs7563468; rs35768389; rs17463896; rs16857265) selected single nucleotide polymorphisms. Results: None of the allelic variants of the nine selected markers was associated with the occurrence of CRC or with the development of regional lymph node metastasis. By contrast, the ROCK1 rs35996865 G variant allele was significantly more frequent in male patients (p = 0.028) than in the control group. Conclusion: This finding is, at present, the first that points to a possible gender-related modulation by the ROCK1 gene in CRC susceptibility.

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