Genes in Gastric Cancer: A Tumor-Suppressive Role for .

Tribbles pseudokinases (TRIB1-3) are important signaling modulators involved in several cancers. However, their function in gastric cancer (GC) remains undefined. GC is still a deadly disease since the lack of sensitive and specific biomarkers for early diagnosis and therapy response prediction negatively affects patients' outcome.

Genotype-first approach to identify associations between CDH1 germline variants and cancer phenotypes: a multicentre study by the European Reference Network on Genetic Tumour Risk Syndromes.

Background: Truncating pathogenic or likely pathogenic variants of CDH1 cause hereditary diffuse gastric cancer (HDGC), a tumour risk syndrome that predisposes carrier individuals to diffuse gastric and lobular breast cancer. Rare CDH1 missense variants are often classified as variants of unknown significance. We conducted a genotype-phenotype analysis in families carrying rare CDH1 variants, comparing cancer spectrum in carriers of pathogenic or likely pathogenic variants (PV/LPV; analysed jointly) or missense variants of unknown significance, assessing the frequency of families with lobular breast cancer among PV/LPV carrier families, and testing the performance of lobular breast cancer-expanded criteria for CDH1 testing.

Genetic and Epigenetic Alterations of Regulatory Regions in Hereditary and Sporadic Gastric Cancer.

E-cadherin is a key player in gastric cancer (GC) and germline alterations of , its encoding gene, are responsible for Hereditary Diffuse Gastric Cancer (HDGC) syndrome. This study aimed at elucidating the role of genetic variants and DNA methylation of promoter and enhancers in the regulation of gene expression. For this purpose, we analyzed genetic variants of the gene through Next-Generation Sequencing (NGS) in a series of GC cell lines (NCI-N87, KATO-III, SNU-1, SNU-5, GK2, AKG, KKP) and the corresponding expression levels.

Definition and management of colorectal polyposis not associated with APC/MUTYH germline pathogenic variants: AIFEG consensus statement.

An expert consensus panel convened by the Italian Association for Inherited and Familial Gastrointestinal Tumors (Associazione Italiana per lo Studio della Familiarità ed Ereditarietà dei Tumori Gastrointestinali, AIFEG) reviewed the literature and agreed on a number of position statements regarding the definition and management of polyposis coli without an identified pathogenic mutation on the APC or MUTYH genes, defined in the document as NAMP (non-APC/MUTYH polyposis).

Multigene Panel Testing Increases the Number of Loci Associated with Gastric Cancer Predisposition.

The main gene involved in gastric cancer (GC) predisposition is , the pathogenic variants of which are associated with diffuse-type gastric cancer (DGC) and lobular breast cancer (LBC). only explains a fraction (10-50%) of patients suspected of DGC/LBC genetic predisposition. To identify novel susceptibility genes, thus improving the management of families at risk, we performed a multigene panel testing on selected patients.

E-cadherin Downregulation and microRNAs in Sporadic Intestinal-Type Gastric Cancer.

gene, encoding E-cadherin, is a tumor suppressor gene frequently altered in gastric cancers (GCs) of both diffuse (DGC) and intestinal (IGC) histotypes, albeit through different mechanisms. The study aimed to characterize expression in sporadic IGC and to investigate whether microRNAs (miRs) are involved in its transcriptional control. We evaluated expression by quantitative real-time PCR (RT-qPCR) in 33 IGC patients and found a significant downregulation in tumor tissues compared to normal counterparts (-value = 0.

Gut Microbiota Analysis in Postoperative Lynch Syndrome Patients.

Lynch syndrome (LS) is a dominantly inherited condition with incomplete penetrance, characterized by high predisposition to colorectal cancer (CRC), endometrial and ovarian cancers, as well as to other tumors. LS is associated with constitutive DNA mismatch repair (MMR) gene defects, and carriers of the same pathogenic variants can show great phenotypic heterogeneity in terms of cancer spectrum. In the last years, human gut microbiota got a foothold among risk factors responsible for the onset and evolution of sporadic CRC, but its possible involvement in the modulation of LS patients' phenotype still needs to be investigated.

Shifts of Faecal Microbiota During Sporadic Colorectal Carcinogenesis.

Gut microbiota has been implicated in the etiopathogenesis of colorectal cancer. The development of colorectal cancer is a multistep process by which healthy epithelium slowly develops into preneoplastic lesions, which in turn progress into malignant carcinomas over time. In particular, sporadic colorectal cancers can arise from adenomas (about 85% of cases) or serrated polyps through the "adenoma-carcinoma" or the "serrated polyp-carcinoma" sequences, respectively.

Detection of a CDH1 Rare Transcript Variant in Fresh-frozen Gastric Cancer Tissues by Chip-based Digital PCR.

CDH1a, a non-canonical transcript of the CDH1 gene, has been found to be expressed in some gastric cancer (GC) cell lines, whereas it is absent in normal gastric mucosa. Recently, we detected CDH1a transcript variant in fresh-frozen tumor tissues obtained from patients with GC. The expression of this variant in tissue samples was investigated by the chip-based digital PCR (dPCR) approach presented here.

A novel APC promoter 1B deletion shows a founder effect in Italian patients with classical familial adenomatous polyposis phenotype.

Familial adenomatous polyposis is a Mendelian syndrome in which germline loss-of-function mutations of APC are associated with multiple adenomatous polyps of the large bowel, a multiplicity of extracolonic features, and a high lifetime risk of colorectal cancer. Different APC germline mutations have been identified, including sequence changes, genomic rearrangements, and expression defects. Recently, very rare families have been associated with constitutive large deletions encompassing the APC-5' regulatory region, while leaving the remaining gene sequence intact; the regulatory region contains a proximal and a distal promoter, called 1A and 1B, respectively.

Hereditary diffuse gastric cancer in two families: A case report.

Hereditary diffuse gastric cancer (HDGC) is associated with E-cadherin 1 () germline mutations. In the present study, two unusual HDGC cases are described. Case 1 was a female with no family history of gastric cancer who developed Hodgkin's lymphoma at 19 years of age, and DGC at 32 years of age.

Digital PCR identifies changes in CDH1 (E-cadherin) transcription pattern in intestinal-type gastric cancer.

E-cadherin is a cell-cell adhesion protein encoded by CDH1 tumor-suppressor gene. CDH1 inactivating mutations, leading to loss of protein expression, are common in gastric cancer of the diffuse histotype, while alternative mechanisms modulating E-cadherin expression characterize the more common intestinal histotype. These mechanisms are still poorly understood.

Colorectal Adenomatous Polyposis: Heterogeneity of Susceptibility Gene Mutations and Phenotypes in a Cohort of Italian Patients.

Aims: Colorectal adenomatous polyposis entailing cancer predisposition is caused by constitutional mutations in different genes. APC is associated with the familial adenomatous polyposis (FAP/AFAP) and MUTYH with the MUTYH-associated polyposis (MAP), while POLE and POLD1 mutations cause the polymerase proofreading-associated polyposis (PPAP).

Methods: We screened for mutations in patients with multiple adenomas/FAP: 121 patients were analyzed for APC and MUTYH mutations, and 36 patients were also evaluated for POLE and POLD1 gene mutations.

Complementary molecular approaches reveal heterogeneous CDH1 germline defects in Italian patients with hereditary diffuse gastric cancer (HDGC) syndrome.

Germline inactivation of the E-cadherin gene (CDH1) is associated with hereditary diffuse gastric cancer (HDGC), a rare autosomal dominant syndrome predisposing to both diffuse gastric cancer (DGC) and lobular breast cancer (LBC). We searched for CDH1 germline defects in 32 HDGC Italian probands selected according to international consensus criteria and in 5 selected relatives. We used a series of molecular methods, including: DNA sequencing, multiplex ligation-dependent probe amplification, single-nucleotide primer extension, bisulfite sequencing, reverse-transcription PCR, and bioinformatics tools.

Understanding the role of the Q338H MUTYH variant in oxidative damage repair.

The MUTYH DNA-glycosylase is indirectly engaged in the repair of the miscoding 7,8-dihydro-8-oxo-2'-deoxyguanine (8-oxodG) lesion by removing adenine erroneously incorporated opposite the oxidized purine. Inherited biallelic mutations in the MUTYH gene are responsible for a recessive syndrome, the MUTYH-associated polyposis (MAP), which confers an increased risk of colorectal cancer. In this study, we functionally characterized the Q338H variant using recombinant proteins, as well as cell-based assays.

Influence of COMT Val158Met polymorphism on Alzheimer's disease and mild cognitive impairment in Italian patients.

COMT (Catechol-O methyltransferase) gene is one of the key players in synaptic plasticity and in learning and memory mechanisms. A single nucleotide polymorphism (rs4680; G to A) in the COMT coding region causes Val158Met aminoacid substitution in the corresponding protein, with Val allele exhibiting a 3- to 4-fold increase in enzyme activity compared to Met. With the purpose of examining the influence of COMT as a genetic risk factor for cognitive impairment, we analyzed a sample of 248 healthy subjects, 276 patients affected by Alzheimer's disease (AD), and 70 subjects with mild cognitive impairment (MCI), the latter condition possibly representing a prodrome for dementia.

Morphine metabolism, transport and brain disposition.

The chemical structures of morphine and its metabolites are closely related to the clinical effects of drugs (analgesia and side-effects) and to their capability to cross the Blood Brain Barrier (BBB). Morphine-6-glucuronide (M6G) and Morphine-3-glucuronide (M3G) are both highly hydrophilic, but only M6G can penetrate the BBB; accordingly, M6G is considered a more attractive analgesic than the parent drug and the M3G. Several hypotheses have been made to explain these differences.

How and why to screen for CYP2D6 interindividual variability in patients under pharmacological treatments.

Cytochromes P450 are members of a superfamily of hemoproteins that catalyze a variety of oxidative reactions in the metabolism of endogenous and exogenous hydrophobic substrates. Fifty-eight cytochrome P450 (CYP) isoenzymes belonging to 18 families have been identified in human cells; the corresponding genes are highly polymorphic, and genetic variability underlies interindividual differences in drug response. The polymorphisms of CYP2D6 significantly affect the pharmacokinetics of about 50% of the drugs in clinical use, which are CYP2D6 substrates.

MUTYH mutations associated with familial adenomatous polyposis: functional characterization by a mammalian cell-based assay.

MUTYH-associated polyposis (MAP) is a colorectal cancer syndrome, due to biallelic mutations of MUTYH. This Base Excision Repair gene encodes for a DNA glycosylase that specifically mitigates the high mutagenic potential of the 8-hydroxyguanine (8-oxodG) along the DNA. Aim of this study was to characterize the biological effects, in a mammalian cell background, of human MUTYH mutations identified in MAP patients (137insIW [c.

Drug transporters and renal drug disposition in the newborn.

The individual response to a drug in terms of drug efficacy and toxicity is highly variable; this represents a major problem in clinical practice. Potential causes for such variability include pathogenesis and severity of the disease being treated, drug interactions, patient age, nutritional status, renal and liver function and concomitant illness. Inherited differences in drug metabolism and genetic polymorphism of targets of drug therapy can have even greater influence on the efficacy and toxicity of medications.

Identification and classification of hereditary nonpolyposis colorectal cancer (Lynch syndrome): adapting old concepts to recent advancements. Report from the Italian Association for the study of Hereditary Colorectal Tumors Consensus Group.

Knowledge about hereditary nonpolyposis colorectal cancer (HNPCC)/Lynch syndrome clearly evolved during the last 10 to 15 years much more rapidly than in the past century. Consequently, long-established concepts and attitudes that held for many years should now be changed or updated. With regard to classification, we suggest maintaining the eponym "Lynch syndrome" for families that have a well-documented deficiency of the DNA mismatch repair system, whereas "clinical hereditary nonpolyposis colorectal cancer" should be reserved for those families that meet the Amsterdam criteria but without evidence of mismatch repair impairment.

Functional analysis and case-control study of -160C/A polymorphism in the E-cadherin gene promoter: association with cancer risk.

Background: A C-->A polymorphism within the CDH1 (E-cadherin) promoter seems to be associated with a reduced efficiency of gene transcription in vitro. Due to the crucial role of E-cadherin in epithelia, tissue-specific effect of C-->A change on CDH1 transcription was tested and a case-control study was performed on patients affected with epithelial tumors.

Patients And Methods: The -178/+93 CDH1 region containing either C or A nucleotide was inserted upstream of the Luciferase reporter gene in the pGL-2 vector, and the construct activity was assessed by transient transfection assay in HeLa and HCT116 cells.