Identification of a new breast cancer-related gene by restriction landmark genomic scanning

Background: Molecular genetic analyses have demonstrated the importance of the accumulation of genomic changes in the etiology of cancer and, additionally, have identified valuable genetic markers for certain cancers. Although several prognostic markers have already been identified for breast cancer, it is clear that others remain to be identified. Materials and Methods: Fourteen breast cancer samples and non-cancerous counterparts were applied to restriction landmark genomic scanning (RLGS) and 6 breast cancer cell lines (MCF-7, MDA-MB-435, T-47D, MDA-MB-231, SK-BR-3 and BT-20) and 9 cancer tissue samples were applied to reverse transcriptional polymerase chain reaction (RT-PCR) for screening of novel genetic alterations. Results: Two spots were identified on the RLGS profiles of cancerous tissue that differed from those of normal tissue. Nucleotide sequencing and homology search analysis showed that these spots represented the voltage-dependent calcium channel α1H subunit gene (CACNA1H gene) and a locus immediately downstream of the growth factor receptor-binding protein 7 (GRB7) gene. Expression of the CACNA1H gene was confirmed by RT-PCR. Conclusion: Two genes, Grb7 and CACNA1H, were identified by RLGS. The expression of CACNA1H in breast cancer was confirmed for the first time.