Tumour samples from 73 CRC patients who were treated in advanced stage with either irinotecan alone or in combination with 5-FU/leucovorin, were analysed for expression of Bcl-2, hMLH1 and hMSH2 using immunohistochemistry.
We analyzed sporadic CRCs in Omani (of African origin, N = 61), Iranian (of Caucasian origin, N = 53) and African American (N = 95) patients for microsatellite instability, expression status of mismatched repair genes (hMLH1, hMSH2) and presence of the BRAF (V600E) mutation.
Moreover, a multivariate analysis revealed that hMLH1 mRNA expression was a significant independent prognostic factor for tumor recurrence in CRC patients treated with adjuvant 5-FU.
We suggest that the I1307K mutation may contribute to CRC in Israeli Arabs and that inactivating mutations of MSH2 and MLH1 may not be a major cause for early onset CRC.
Prevalence of MLH1/MSH2 mutations in CRC families was significantly increased by the presence of: (i) fulfilled Amsterdam criteria; (ii) four or more CRCs; or (iii) one or more endometrial cancer.
In order to assess the role of these genes in sporadic RER+ colorectal carcinoma, we have carried out a mutation analysis of MSH2 and MLH1 by two-dimensional (2-D) DNA electrophoresis, including heteroduplexing and separation in a denaturing gradient.
In order to better understand the role of somatic and germline alterations within hMSH2 and hMLH1 in the process of colorectal tumorigenesis, we examined the entire coding regions of both of these genes in seven patients with MIN+ sporadic colorectal cancer, 19 patients with familial colorectal cancer, and 20 patients meeting the strict Amsterdam criteria for HNPCC.