Colorectal cancer screening: Assessment of CEACAM6, LGALS4, TSPAN8 and COL1A2 as blood markers in faecal immunochemical test negative subjects.

Prevention is essential to reduce Colorectal Cancer (CRC) mortality. We previously reported a panel of four genes: CEACAM6, LGALS4, TSPAN8, COL1A2 (CELTiC) able to discriminate patients with CRC. Here, we assessed the CELTiC panel by quantitative polymerase chain reaction, in the blood of 174 healthy subjects, who resulted negative to the faecal immunochemical test (FITN). Using non-parametric statistic and multinomial logistic models, the FITN were compared to previously analysed subjects: 36 false positive FIT (NFIT), who were negative at colonoscopy, 36 patients with low risk lesions (LR) and 92 patients with high risk lesions or CRC (HR/CRC). FITN showed a significantly lower expression of the four genes when compared to HR/CRC. Moreover, FITN showed a significantly lower expression of TSPAN8 and COL1A2 compared to NFIT and LR patients. The multinomial logistic model confirmed that TSPAN8 alone specifically discriminated FITN from NFIT, LR and HR/CRC, while LGALS4 was able to differentiate FITN from false positive FIT. Finally, ROC curves analysis of the comparisons between FITN and HR/CRC, LR or NFIT reported AUC greater than 0.87, with a sensitivity and specificity of 83% and 76%, respectively. The CELTiC panel was confirmed a useful tool to identify CRC patients and to discriminate false FIT positive subjects.

LGALS4, CEACAM6, TSPAN8, and COL1A2: Blood Markers for Colorectal Cancer-Validation in a Cohort of Subjects With Positive Fecal Immunochemical Test Result.

BACKGROUND: A noninvasive blood test for the early detection of colorectal cancer (CRC) is highly required. We evaluated a panel of 4 mRNAs as putative markers of CRC. MATERIALS AND METHODS: We tested LGALS4, CEACAM6, TSPAN8, and COL1A2, referred to as the CELTiC panel, using quantitative reverse transcription polymerase chain reaction, on subjects with positive fecal immunochemical test (FIT) results and undergoing colonoscopy. Using a nonparametric test and multinomial logistic model, FIT-positive subjects were compared with CRC patients and healthy individuals. RESULTS: All the genes of the CELTiC panel displayed statistically significant differences between the healthy subjects (n = 67), both low-risk (n = 36) and high-risk/CRC (n = 92) subjects, and those in the negative-colonoscopy, FIT-positive group (n = 36). The multinomial logistic model revealed LGALS4 was the most powerful marker discriminating the 4 groups. When assessing the diagnostic values by analysis of the areas under the receiver operating characteristic curves (AUCs), the CELTiC panel reached an AUC of 0.91 (sensitivity, 79%; specificity, 94%) comparing normal subjects to low-risk subjects, and 0.88 (sensitivity, 75%; specificity, 87%) comparing normal and high-risk/CRC subjects. The comparison between the normal subjects and the negative-colonoscopy, FIT-positive group revealed an AUC of 0.93 (sensitivity, 82%; specificity, 97%). CONCLUSION: 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.

Systematic large-scale meta-analysis identifies a panel of two mRNAs as blood biomarkers for colorectal cancer detection.

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.

Possible Gender-Related Modulation by the ROCK1 Gene in Colorectal Cancer Susceptibility.

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.

Human Multidrug Resistance 1 gene polymorphisms and Idiopathic Pulmonary Fibrosis.

BACKGROUND: For the first time we tested an association between the human multidrug resistance gene 1 (MDR1) polymorphisms (SNPs) and idiopathic pulmonary fibrosis (IPF). Several MDR1 polymorphisms are associated with pathologies in which they modify the drug susceptibility and pharmacokinetics. MATERIALS AND METHODS: We genotyped three MDR1 polymorphisms of 48 IPF patients and 100 control subjects with Italian origins. RESULTS: No evidence of association was detected. CONCLUSION: There are 50 known MDR1 SNPs, and their role is explored in terms of the effectiveness of drug therapy. We consider our small-scale preliminary study as a starting point for further research.

A candidate gene study of one-carbon metabolism pathway genes and colorectal cancer risk.

The risk of colorectal cancer (CRC) may be influenced by aberrant DNA methylation and altered nucleotide synthesis and repair, possibly caused by impaired dietary folate intake as well as by polymorphic variants in one-carbon metabolism genes. A case-control study using seventy-one CRC patients and eighty unrelated healthy controls was carried out to assess the genetic association of fifteen SNP and one insertion in nine genes belonging to the folate pathway. Polymorphism selection was based on literature data, and included those which have a known or suspected functional impact on cancer and missense polymorphisms that are most likely to alter protein function. Genotyping was performed by real-time PCR and PCR followed by restriction analysis. The likelihood ratio statistic indicated that most of the polymorphisms were not associated with the risk of CRC. However, an increased risk of CRC was observed for two variant alleles of SNP mapping on the transcobalamin 2 gene (TCN2): C776G (rs1801198) and c.1026-394T>G (rs7286680). Considering the crucial biological function played by one-carbon metabolism genes, further investigations with larger cohorts of CRC patients are needed in order to confirm our preliminary results. These preliminary results indicate that TCN2 polymorphisms can be a susceptibility factor for CRC.

Idiopathic pulmonary fibrosis and polymorphisms of the folate pathway genes.

OBJECTIVES: This study aims to determine the possible association between folate pathway gene polymorphisms and idiopathic pulmonary fibrosis. This represents the first study carried out on folate pathway gene polymorphisms as possible risk factors in this kind of pathology. The premise is that several polymorphisms mapping on genes responsible for folate uptake are associated with the risk of numerous diseases occurring between pregnancy and old age, and that too little is currently known about idiopathic pulmonary fibrosis. DESIGN AND METHODS: We genotyped 9 single nucleotide polymorphisms and 1 polymorphic insertion in 7 essential genes belonging to the folate pathway in 32 Italian idiopathic pulmonary fibrosis patients and 81 control subjects. This was done by PCR and restriction analysis. RESULTS: Allelic and genotypic association tests indicated that for all the analysed polymorphisms there were no significant differences between patients and controls. Nevertheless, the haplotype association analysis revealed a significant association between idiopathic pulmonary fibrosis and transcobalamin II gene polymorphisms: specifically the haplotype 776G (rs1801198)-c.1026-394G (rs7286680)-444C (rs10418) (OR=2.84; 95% C.I. 1.36-5.93, P value=0.004). CONCLUSIONS: This small-scale preliminary study would suggest the importance of further research focusing on the role of folate in the onset of idiopathic pulmonary fibrosis.

IL23R, NOD2/CARD15, ATG16L1 and PHOX2B polymorphisms in a group of patients with Crohn's disease and correlation with sub-phenotypes.

Recent genomic research has identified interleukin-23 receptor (IL23R), nucleotide-binding oligomerization domain containing 2 caspase-activation recruitment domain 15 (NOD2/CARD15), autophagy related 16-like 1 (ATG16L1) and paired-like homeobox 2b (PHOX2B) as susceptibility loci for Crohn's Disease (CD). Our aim was to investigate these gene variants in a group of CD patients and to analyse the correlation to sub-phenotypes such as gender, smoking habits, disease behaviour at diagnosis, severity of disease and extra-intestinal manifestations. Nineteen patients with CD and 20 healthy controls were included in the study. The gene variants IL23R rs7517847 and rs11209026, NOD2/CARD15 rs2066845, PHOX2B rs16853571, ATG16L1 rs2241879 and rs2241880 were genotyped by PCR followed by sequencing. The frequency of the G risk allele of IL23R rs7517847 was found to be increased in patients with CD (42%) compared to that in control subjects (20%) [odds ratio (OR), 2.9; 95% confidence interval [CI], 1.06-7.9; P=0.03]. In addition, the homozygous condition GG was also associated with CD (OR, 8.70; 95% CI, 0.9-81.6; P=0.038). The analysis of correlation of genotype to sub-phenotypes showed an association of ATG16L1 rs2241879 with the lack of extra-intestinal manifestations (OR, 0.03; 95% CI, 0.002-0.45; P=0.006), and the patients defined as non-smokers displayed an increased frequency of the risk allele C (P=0.03). The present study confirms the association of the heterozygous and homozygous IL23R rs7517847 variant with CD and suggests an additive effect of smoking to the ATG16L1 rs2241879 C risk allele SNP, in the context of the multifactorial model established for the development of CD and a protective effect of the same allele against extra-intestinal manifestations.

A role for epidermal growth factor receptor in idiopathic pulmonary fibrosis onset.

In idiopathic pulmonary fibrosis (IPF) patients the presence of missense polymorphisms (SNP) in members of the epidermal growth factor receptor (EGFR) family or their genetic association could influence the binding affinity of natural ligands, modifying the expression and the behavior of the correlated genes. EGFR family members are particularly involved in the epithelial injury and fibrotic process in IPF. Genetic variations in HER family of receptors may alter the possible therapeutic efficacy of EGFR inhibitors. This study aimed to analyze the relationships between IPF and specific EGF receptor family functional polymorphisms. We tested the presence of common EGFR, HER2 and HER3 non-synonymous SNPs in the peripheral blood of 20 Italian IPF patients and their association with the disease. Our data indicated that the HER2 variant allele frequency was significantly lower in patients than in controls, with an odds ratio of 0.31 (95% CI 0.080, 0.98). Our finding suggests that HER2 variant could be a protective factor against IPF onset.

Identification by a Digital Gene Expression Displayer (DGED) and test by RT-PCR analysis of new mRNA candidate markers for colorectal cancer in peripheral blood.

Evidence from the literature widely supports the efficacy of screening for colorectal cancer (CRC) in reducing mortality. A blood-based assay, potentially, represents a more accessible early detection tool for the identification of circulating tumour cells originating from a primary tumour site in the body. The present work aimed at identifying a set of specific mRNAs expressed in colon tissue but not in blood cells. These mRNAs may represent useful markers for early detection of circulating colon cancer cells by a simple, qualitative RT-PCR assay, following RNA extraction from peripheral blood samples. Using a data-mining tool called cDNA digital gene expression displayer (DGED), based on serial analysis of gene expression (SAGE) from the Cancer Genome Anatomy Project (CGAP) database, 4-colon and 14-blood cDNA libraries were analyzed. We selected 7 genes expressed in colon tissue but not in blood and were able to test 6 of them by RT-PCR in peripheral blood of CRC patients and healthy controls. We present a relatively easy and highly reproducible technique for the detection of mRNA expression of genes as candidate markers of malignancy in blood samples of patients with colon cancer. SAGE DGED provided a list of the best candidate mRNAs predicted to detect colon cells in the blood, namely those encoding the following proteins: hypothetical protein LOC644844 (LOC644844, whose cDNA was not amplifiable), fatty acid binding protein 1 (FABP1), carcinoembryonic antigen-related cell adhesion molecule 5 (CEACAM5), mucin 13 cell surface associated (MUC13), guanylate cyclase activator 2A (GUCA2A), amiloride binding protein 1 (ABP1), galactoside-binding, solute carrier family 26, member 3 (SLC26A3). The mRNA expression of these genes was evaluated in 8 samples from subjects diagnosed with CRC and 9 from healthy controls. We observed the expression of 2 of the 6 investigated genes in the blood samples of the vast majority of patients considered, but also in a subset of the controls. Our data confirm the extreme sensitivity of RT-PCR, making this technique able to detect minimal amounts of mRNA expressed in a non-tissue-specific manner. Moreover, DGED remains a powerful tool to identify candidate epithelial markers in blood, such as colon related mRNAs. However, to date, none of these qualified as tumour markers.

The EGFR R521K polymorphism influences the risk to develop colorectal cancer.

Epidermal growth factor receptor (EGFR) family members (EGFR, HER2, HER3 and HER4) have been extensively investigated for its possible involvement in cancer development and progression. In colorectal cancer (CRC) EGFR family has been found frequently over-expressed, thus therapy targeting EGFR has been developed. Interestingly, it has been observed that genetic variants in these receptors may alter the therapeutic efficacy of EGFR inhibitors. Polymorphic variants in members of the EGFR family could influence different biologic activities, such as ligands affinity, dimerization efficiency, kinase activity, expression levels, with a consequent impact in signalling pathways and cell behaviour. This study aimed to verify whether single nucleotide polymorphisms (SNPs) of EGFR family members could represent susceptibility factors able to influence the risk to develop CRC. Peripheral blood of 70 Italian colon cancer patients and 72 healthy controls was used as a source of genomic DNA to investigate EGFR, HER2 and HER3 common non-synonymous SNPs. Genetic association tests were performed to verify a possible relationship with CRC. Evidence of genotype association was found for the R521K EGFR polymorphism under a dominant mode of inheritance (Mid-P=0.031). Genotypes with the variant allele of EGFR R521K SNP confer a risk reduction to develop CRC.

Displayed correlation between gene expression profiles and submicroscopic alterations in response to cetuximab, gefitinib and EGF in human colon cancer cell lines.

BACKGROUND: EGFR is frequently overexpressed in colon cancer. We characterized HT-29 and Caco-2, human colon cancer cell lines, untreated and treated with cetuximab or gefitinib alone and in combination with EGF. METHODS: Cell growth was determined using a variation on the MTT assay. Cell-cycle analysis was conducted by flow cytometry. Immunohistochemistry was performed to evaluate EGFR expression and scanning electron microscopy (SEM) evidenced the ultrastructural morphology. Gene expression profiling was performed using hybridization of the microarray Ocimum Pan Human 40 K array A. RESULTS: Caco-2 and HT-29 were respectively 66.25 and 59.24 % in G0/G1. They maintained this level of cell cycle distribution after treatment, suggesting a predominantly differentiated state. Treatment of Caco-2 with EGF or the two EGFR inhibitors produced a significant reduction in their viability. SEM clearly showed morphological cellular transformations in the direction of cellular death in both cell lines treated with EGFR inhibitors. HT-29 and Caco-2 displayed an important reduction of the microvilli (which also lose their erect position in Caco-2), possibly invalidating microvilli absorption function. HT-29 treated with cetuximab lost their boundary contacts and showed filipodi; when treated with gefitinib, they showed some vesicles: generally membrane reshaping is evident. Both cell lines showed a similar behavior in terms of on/off switched genes upon treatment with cetuximab. The gefitinib global gene expression pattern was different for the 2 cell lines; gefitinib treatment induced more changes, but directly correlated with EGF treatment. In cetuximab or gefitinib plus EGF treatments there was possible summation of the morphological effects: cells seemed more weakly affected by the transformation towards apoptosis. The genes appeared to be less stimulated than for single drug cases. CONCLUSION: This is the first study to have systematically investigated the effect of cetuximab or gefitinib, alone and in combination with EGF, on human colon cancer cell lines. The EGFR inhibitors have a weaker effect in the presence of EGF that binds EGFR. Cetuximab treatment showed an expression pattern that inversely correlates with EGF treatment. We found interesting cyto-morphological features closely relating to gene expression profile. Both drugs have an effect on differentiation towards cellular death.