Loss of heterozygosity on chromosome 3p in breast cancer and precancerous lesion

Abstract

To study the loss of heterozygosity (LOH) on chromosome 3p in breast cancers and precancerous lesion. LOH at 11 microsatellite loci was detected in 41 cases of breast cancers and 12 cases of precancerous lesion by polymerase chain reaction and silver stain. The expressions of ER, PR, FHIT and hMLH1 were detected in breast cancer by immunohistochemistry. LOH on 3p was detected in 97% of breast cancers. D3S1295, D3S1029 and D3S1038 located at 3p14, 3p21-p22 and 3p25 were identified as the loci with most frequent LOH (53.1%, 43.6% and 52.5%). LOH of D3S1038 and expression of hMLH1 protein correlated with several clinicopathological features. LOH of D3S1295 had significant negative correlation with the expression of FHIT. In breast precancerous lesions, LOH on 3p was detected in 41.7% lesions. D3S1295 and D3S1029 were also identified as the most frequent LOH locus (27.3% and 16.7%). The smallest common LOH region seems likely lie between 3p14 and 3p25. The smallest LOH region indicates the existence of breast tumor related genes and some of them affect gene expression.