Search results for "K-ras"

Analisi dei fattori che rendono le cellule di adenocarcinoma colorettale resistenti o suscettibili all’azione di chemioterapici

2015

Specific codon 13 K-ras mutations are predictive of clinical outcome in colorectal cancer patients, whereas codon 12 K-ras mutations are associated w…

2002

Background: K-ras mutations, one of the earliest events observed in colorectal carcinogenesis, are mostly found in codons 12 and 13, and less frequently in codon 61, all three of which are estimated to be critical for the biological activity of the protein. Nevertheless the prognostic significance of such mutations remains controversial. Our purpose was to assess whether any or specific K-ras mutations in primary colorectal cancer had prognostic significance and were linked to clinico-pathological parameters. Patients and methods: Paired tumor and normal tissue samples from a consecutive series of 160 untreated patients (median of follow up 71 months), undergoing resective surgery for prima…

Systemic inflammatory status predict the outcome of k-RAS WT metastatic colorectal cancer patients receiving the thymidylate synthase poly-epitope-pe…

2018

// Pierpaolo Correale 1 , Cirino Botta 2 , Nicoletta Staropoli 3 , Valerio Nardone 4 , Pierpaolo Pastina 4 , Cristina Ulivieri 5 , Claudia Gandolfo 6 , Tatiana Cosima Baldari 5 , Stefano Lazzi 7 , Domenico Ciliberto 3 , Rocco Giannicola 1 , Antonella Fioravanti 8 , Antonio Giordano 9 , Silvia Zappavigna 10 , Michele Caraglia 9, 10 , Pierfrancesco Tassone 2, 3, 10 , Luigi Pirtoli 4 , Maria Grazia Cusi 6 and Pierosandro Tagliaferri 3 1 Unit of Medical Oncology, Grand Metropolitan Hospital Bianchi Melacrino Morelli, Reggio-Calabria, Italy 2 Medical Oncology Unit, AUO Mater Domini, Magna Graecia University, Catanzaro, Italy 3 Department of Experimental and Clinical Medicine, Magna Graecia Unive…

Effetti dell'espressione di K-RasG12V e K-RasG13D in cellule di adenocarcinoma colorettale HT29

2013

RAS è una piccola proteina di 21kDa che si trova frequentemente mutata nei tumori. La famiglia dei geni ras consta di tre principali protoncogeni chiamati H-, K- e N-Ras. Le tre isoforme di Ras regolano la proliferazione, il differenziamento e la morte cellulare mediante l’attivazione di diversi pathways di trasduzione del segnale fra cui la cascata delle MAP chinasi e il pathway di PI3K/AKT. Le diverse isoforme di Ras attivano tutte gli stessi pathways, ma con diversa efficienza, e ciò potrebbe essere, almeno in parte, una conseguenza delle loro differenti modifiche post-traduzionali che determinano la localizzazione in specifici microdomini della membrana plasmatica. Diversi studi hanno d…

Codon 12 and codon 13 mutations in K-RAS differentially affect therapies response of colorectal carcinoma cells

2014

Antisense gene therapy using anti-k-ras and antitelomerase oligonucleotides in colorectal cancer

2005

Aim: to test the efficacy of anti-k-ras and antitelomerase oligonucleotides for disabling colorectal cancer cell growth. Material and methods: an established human colorectal cancer cell line (SW 480, ATTC ® ) was used. Oligodeoxiribonucleotides (ODNs) have a phosphorotioate modification to ensure intracellular intake. We used an antitelomerase ODN (Telp5) and two anti-k-ras ODNs (AS-KRAS and ISIS). AS-KRAS is designed to join the k-ras oncogene’s exon 1. ISIS links to the terminal transcription unit 5’ of k-ras. Telp5 joins the template region of the hTR telomerase subunit. ODNs have been tested in different concentrations (1, 5, 10, 20 micromolar). Cell viability has been tested at 48 and…

Analisi degli effetti del Cetuximab in linee cellulari di adenocarcinoma colorettale

2013

Il carcinoma del colon-retto (CRC) è una malattia eterogenea, che si sviluppa in seguito a numerose alterazioni genetiche ed epigenetiche. Una famiglia genica che si trova frequentemente mutata nei tumori è quella di ras che consta di tre principali protoncogeni (H-, K- e N-Ras) localizzati su cromosomi differenti e codificanti proteine G del peso di 21 KDa. Il 50% dei casi di CRC presenta mutazioni puntiformi missense a carico del gene KRAS, il 90% delle quali si verifica a livello dei codoni 12 e 13 e rende la proteina costitutivamente attiva. Diversi studi dimostrano come mutazioni di differenti codoni di K-Ras potrebbero avere diverse conseguenze biologiche e determinare una diversa ris…

Patterns of K-ras mutation in colorectal carcinomas from Iran and Italy (a Gruppo Oncologico dell'Italia Meridionale study): influence of microsatell…

2006

Background: K-ras mutations are a key step in colorectal cancer progression. Such mutations have been widely studied in case series from Western countries but there are few data on the rate and spectrum of mutations in tumors from countries where the epidemiological features of the disease are different. Patients and methods: Tumor samples from 182 Iranian colorectal cancer patients (170 sporadic cases and 12 HNPCC cases) were screened for K-ras mutations at codons 12, 13 and 61 by sequencing analysis. The cases were also characterized for microsatellite instability at mononucleotide repeats by PCR and fragment analysis, and classified according to microsatellite instability status. The fre…

DNA aneuploidy and high proliferative activity but not K-ras-2 mutations as independent predictors of clinical outcome in operable gastric carcinoma:…

2001

BACKGROUND The prognostic value of DNA ploidy, S-phase fraction (SPF) and K-ras-2 mutations in gastric carcinoma (GC) has not yet been clearly defined. The aim of this study was to clarify the association between biomolecular variables, tumor characteristics, and clinical outcome in GC patients. METHODS Resected specimens from a consecutive series of 69 patients with GC who underwent potentially curative surgery were studied prospectively. DNA ploidy and SPF were assessed by flow cytometry on multiple frozen tumor samples, whereas K-ras-2 mutations were detected by polymerase chain reaction followed by single-strand conformation polymorphism. All the patients involved in this study were fol…

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…