[Localization and analysis of 1A6 gene by dual-color fluorescence in situ hybridization on gastric carcinoma tissue and tumor cell lines].
OBJECTIVE
To locate 1A6 gene on the chromosome and study its copy number by dual-color fluorescence in situ hybridization (FISH) on three tumor cell lines and 22 gastric tumors patients.


METHODS
The single-color FISH of small size biotin-labeled cDNA cloned in plasmid was used to locate the 1A6 gene on one of the chromosomes in C group. Genomic DNA of 1A6 gene was screened by polymerase chain reaction (PCR) in PAC library according to the sequence. The florenscence of green and orange was incorporated into the target gene-1A6 cloned in PAC and chromosome-12-specific alpha-satellite repeat DNA by nick translation, followed by dual-color FISH. 1A6 gene was located in the metaphase chromosome of the normal peripheral lymphocytes. 1A6 gene and chromosome 12 copy numbers were analyzed on touch slide of gastric cancer tissue and cell lines.


RESULTS
1A6 gene was located in 12q23.2-23.3. The chromosome 12/1A6 signal ratio was 0.96-1.01 in breast, ovarian and gastric cancer cell lines. The ratio was 0.93-1.11 in gastric cancer tissue touch slides. The number of chromosome 12 is disomic (87.7%), triploid (7.4%) in BMI cell line; multisomic(100%), including pentasomic (67.6%) in SKOV3; the multisomic (83.1%), including trisomic (71%) in SGC823. There are highly disomic rate in 86. 4% (19/22) of patients.


CONCLUSIONS
1A6 gene is in 12q23.2-23.3. Neither 1A6 amplification nor deletion in gastric cancer tissue and three cell lines was found. Further study is needed for the understanding of chromosome 12 copy number variation in different cancer cell lines.
Zheng
S
S
Genetic Laboratory, Beijing Institute for Cancer Research, Beijing University Institute of Oncology, Beijing 100034, China.
Ke
Y
Y
D002874:Chromosome Mapping; D002881:Chromosomes, Human, Pair 12; D006801:Humans; D017404:In Situ Hybridization, Fluorescence / Q000379:methods; D013274:Stomach Neoplasms / Q000235:genetics*; D014407:Tumor Cells, Cultured