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.


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 transcnptionalpolymerase 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 alpha1H 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.


CONCLUSIONS
Two genes, Grb7 and CACNA1H, were identified by RLGS. The expression of CACNA1H in breast cancer was confirmed for the first time.
Department of Surgery, Keio University School of Medicine, 35 Shinanomachi, Shinjuku-ku, Tokyo, 160-8582, Japan.
Sota
S
Asaga
Masakazu
M
Ueda
Hiromitsu
H
Jinno
Kiyoshi
K
Kikuchi
Osamu
O
Itano
Tadashi
T
Ikeda
Masaki
M
Kitajima
D000328:Adult; D001483:Base Sequence; D001943:Breast Neoplasms / Q000235:genetics*; D020747:Calcium Channels, T-Type / Q000235:genetics*; D045744:Cell Line, Tumor; D005260:Female; D051382:GRB7 Adaptor Protein / Q000235:genetics; D020869:Gene Expression Profiling; D015894:Genome, Human; D006801:Humans; D008875:Middle Aged; D008969:Molecular Sequence Data; D020133:Reverse Transcriptase Polymerase Chain Reaction
C479952:CACNA1H protein, human; D020747:Calcium Channels, T-Type; C495955:GRB7 protein, human; D051382:GRB7 Adaptor Protein