Loss of Heterozygosity at the Brca1 Locus in Romanian Cancer Patients

BRCA1 is a tumor suppressor gene and any alteration of its functions can contribute to cancer development and progression. The loss of heterozigosity (LOH), meaning the loss of the normal functional allele in a heterozygous locus of a tumor suppressor such as BRCA1 gene. leads to wild-type gene inactivation and can be correlated with cancer. The role of BRCA1 LOH has already been demonstrated in familial and sporadic breast cancer. Little is known about BRCA1 LOB correlated with other types of familial cancers such as prostate cancer, esophageal cancer or gastric cancer and even less about BRCA1 LOH correlations with the types of sporadic cancers. The aim of this study was to investigate the correlation between distinct BRCA1 alterations and tumor site or cancer progression in Romanian patients with prostate. esophageal and gastric cancer. For this purpose polymerase chain reaction (PCR)-based microsatellite analysis was used to detect LOB occurring in regions mapping for BRCA1 gene. From all the five analyzed microsatellites, three (D17S855. D17S856 and D17S1322) presented loss of heterozygosity in the DNA extracted from the tumor tissue of different patients. 28% of all analyzed patients, presented loss of heterozygosity of at least one microsatellite marker corresponding to BRCA1 gene locus.