Search results for " Mutation"
showing 10 items of 1212 documents
The TP53 colorectal cancer international collaborative study on the prognostic and predictive significance of p53 mutation: influence of tumor site, …
2005
Purpose The aims of the TP53 Colorectal Cancer (CRC) International Collaborative Study were to evaluate the possible associations between specific TP53 mutations and tumor site, and to evaluate the prognostic and predictive significance of these mutations in different site, stage, and treatment subgroups. Patients and Methods A total of 3,583 CRC patients from 25 different research groups in 17 countries were recruited to the study. Patients were divided into three groups according to site of the primary tumor. TP53 mutational analyses spanned exons 4 to 8. Results TP53 mutations were found in 34% of the proximal colon tumors and in 45% of the distal colon and rectal tumors. They were assoc…
Cetuximab in small bowel adenocarcinoma: a new friend?
2010
Sir, Small bowel adenocarcinoma (SBA) is a rare and aggressive tumour. SBA in the United States increased from 5.7 cases per million in 1973 to 7.3 cases per million in 2004 (Surveillance Epidemiology and End Results (SEER), 1973–2004 database; Jemal et al (2009). Surgery is the mainstay of treatment, even if chemotherapy in advanced disease has been associated with an increased survival. The most effective agents include 5-FU, irinotecan, platinum agents and gemcitabine (Fishman et al, 2006; Speranza et al, 2010). The molecular characterisation of this cancer could help to improve prognosis. Specifically, the frequency of KRAS gene mutations is similar than in colorectal cancer (Ari et al,…
Specific TP53 and/or Ki-ras mutations as independent predictors of clinical outcome in sporadic colorectal adenocarcinomas: results of a 5-year Grupp…
2005
BACKGROUND: Although Ki-ras and TP53 mutations have probably been the genetic abnormalities most exhaustively implicated and studied in colorectal cancer (CRC) progression, their significance in terms of disease relapse and overall survival has not yet clearly been established. PATIENTS AND METHODS: A prospective study was carried out on paired tumor and normal colon tissue samples from a consecutive series of 160 previously-untreated patients, undergoing resective surgery for primary operable sporadic CRC. Mutations within the TP53 (exons 5-8) and Ki-ras (exon 2) genes were detected by PCR-SSCP analyses following sequencing. RESULTS: Mutation analyses of exons 5 to 8 of the TP53 gene showe…
A new mitochondrial point mutation in the transfer RNALys gene associated with progressive external ophthalmoplegia with impaired respiratory regulat…
2011
Abstract We report a novel heteroplasmic point mutation G8299A in the gene for mitochondrial tRNA Lys in a patient with progressive external ophthalmoplegia complicated by recurrent respiratory insufficiency. Biochemical analysis of respiratory chain complexes in muscle homogenate showed a combined complex I and IV deficiency. The transition does not represent a known neutral polymorphism and affects a position in the tRNA acceptor stem which is conserved in primates, leading to a destabilization of this functionally important domain. In vitro analysis of an essential maturation step of the tRNA transcript indicates the probable pathogenicity of this mutation. We hypothesize that there is a…
Bone morphogenetic protein 4 induces differentiation of colorectal cancer stem cells and increases their response to chemotherapy in mice.
2010
BACKGROUND & AIMS: The limited clinical response observed in many patients with colorectal cancer may be related to the presence of chemoresistant colorectal can- cer stem cells (CRC-SCs). Bone morphogenetic protein 4 (BMP4) promotes the differentiation of normal colonic stem cells. We investigated whether BMP4 might be used to induce differentiation of CRC-SCs and for therapeutic purposes. METHODS: CRC-SCs were isolated from 25 tumor samples based on expression of CD133 or using a selection culture medium. BMP4 expression and activity on CRC-SCs were evaluated in vitro; progeny of the stem cells were evaluated by immunofluorescence, immuno- blot, and flow cytometry analyses. The potential …
Risk Profiles and Penetrance Estimations in Multiple Endocrine Neoplasia Type 2A Caused by Germline RET Mutations Located in Exon 10
2010
Multiple endocrine neoplasia type 2 is characterized by germline mutations in RET. For exon 10, comprehensive molecular and corresponding phenotypic data are scarce. The International RET Exon 10 Consortium, comprising 27 centers from 15 countries, analyzed patients with RET exon 10 mutations for clinical-risk profiles. Presentation, age-dependent penetrance, and stage at presentation of medullary thyroid carcinoma (MTC), pheochromocytoma, and hyperparathyroidism were studied. A total of 340 subjects from 103 families, age 4-86, were registered. There were 21 distinct single nucleotide germline mutations located in codons 609 (45 subjects), 611 (50), 618 (94), and 620 (151). MTC was present…
Clinical characteristics of patients with familial amyotrophic lateral sclerosis carrying the pathogenic GGGGCC hexanucleotide repeat expansion of C9…
2012
A large hexanucleotide (GGGGCC) repeat expansion in the first intron of C9ORF72, a gene located on chromosome 9p21, has been recently reported to be responsible for 40% of familial amyotrophic lateral sclerosis cases of European ancestry. The aim of the current article was to describe the phenotype of amyotrophic lateral sclerosis cases carrying the expansion by providing a detailed clinical description of affected cases from representative multi-generational kindreds, and by analysing the age of onset, gender ratio and survival in a large cohort of patients with familial amyotrophic lateral sclerosis. We collected DNA and analysed phenotype data for 141 index Italian familial amyotrophic l…
A multi-centre clinico-genetic analysis of the VPS35 gene in Parkinson disease indicates reduced penetrance for disease-associated variants
2012
Abstract: Background Two recent studies identified a mutation (p.Asp620Asn) in the vacuolar protein sorting 35 gene as a cause for an autosomal dominant form of Parkinson disease. Although additional missense variants were described, their pathogenic role yet remains inconclusive. Methods and results We performed the largest multi-center study to ascertain the frequency and pathogenicity of the reported vacuolar protein sorting 35 gene variants in more than 15,000 individuals worldwide. p.Asp620Asn was detected in 5 familial and 2 sporadic PD cases and not in healthy controls, p.Leu774Met in 6 cases and 1 control, p.Gly51Ser in 3 cases and 2 controls. Overall analyses did not reveal any sig…
The Insulin Receptor Substrate 1 (Irs1) in Intestinal Epithelial Differentiation and in Colorectal Cancer
2012
Colorectal cancer (CRC) is associated with lifestyle factors that affect insulin/IGF signaling, of which the insulin receptor substrate 1 (IRS1) is a key transducer. We investigated expression, localization and pathologic correlations of IRS1 in cancer-uninvolved colonic epithelium, primary CRCs with paired liver metastases and in vitro polarizing Caco2 and HT29 cells. IRS1 mRNA and protein resulted higher, relative to paired mucosa, in adenomas of familial adenomatous polyposis patients and in CRCs that overexpressed c-MYC, ß-catenin, InsRß, and IGF1R. Analysis of IRS1 immunostaining in 24 cases of primary CRC with paired colonic epithelium and hepatic metastasis showed that staining inten…
Prognostic significance of K-Ras mutation rate in metastatic colorectal cancer patients
2015
// Bruno Vincenzi 1 , Chiara Cremolini 2 , Andrea Sartore-Bianchi 3 , Antonio Russo 4 , Francesco Mannavola 5 , Giuseppe Perrone 6 , Francesco Pantano 1 , Fotios Loupakis 2 , Daniele Rossini 2 , Elena Ongaro 7 , Erica Bonazzina 3 , Emanuela Dell’Aquila 1 , Marco Imperatori 1 , Alice Zoccoli 1 , Giuseppe Bronte 4 , Giovanna De Maglio 7 , Gabriella Fontanini 8 , Clara Natoli 9 , Alfredo Falcone 2 , Daniele Santini 1 , Andrea Onetti-Muda 6 , Salvatore Siena 3 , Giuseppe Tonini 1 and Giuseppe Aprile 7 1 Department of Medical Oncology, Campus Bio-Medico University of Rome, Rome, Italy 2 Azienda Ospedaliero-Universitaria Pisana, Istituto Toscano Tumori, Pisa, Italy 3 Niguarda Cancer Center, Osped…