Detection And Identification Of Nonrandom Genomic DNA Imbalances In Esophageal Squamous Cell Carcinomas

Esophageal squamous cell cacinomas(ESCC) is one of the most common tumors in human. It ranks the forth most prevalent malignancy in China. Previous studies revealed multiple genetic and epigenetic alterations, but so far, the events involved in esophageal cancer remain largely unknown. A number of technical difficulties limited the large scale karyotypic analyses of ESCC. To surveying chromosome imbalances and identify high-frequency changes in this disease, we performed comparative genomic hybridization (CGH) in 30 primary esophageal squamous cell carcinomas and three cancer cell lines of the esophagus, then further analyzed molecular alterations by real time quantitative PCR.Among the 30 tumors, nonrandom copy number changes in chromosome DNA were detected except for one case, with higher incidence in gain than in loss. The average gains and losses per patient were 6.9 and 3.5, respectively. The common gains were 3q (24/30), 8q (17/30), 1q (16/30), 20q (13/30) and 5p (12/30), with two minimal amplification loci mapped to chromosomal regions of 8q24 (3 cases) and 11q13 (9 cases). In chromosomes 1 and 3, minimal regions of overlap occurred at 1q24-q31 (16/ 30) and 3q24-q29 (24/30). High-level amplifications were observed at 3q, 5p, and 8q. Losses at chromosome 3p (14/30), 13q (9/30), 9p (8/30), 18q (7/30), 4q (6/30), 14q (6/30), 18p (6/30), 21q (6/30) and Xp (6/30) were identified. 14 cases showed both loss of the entire 3p and overpresentation of almost the whole 3q. High-level amplification of 5p and loss of X were observed in all the cell lines. There was a significant higher incidence of Xp loss in lymph nodes metastasis...