Cytogenetic and fluorescence in situ hybridization characterization of clonal chromosomal aberrations and CCND1 amplification in esophageal carcinomas

Cytogenetic analyses of four squamous cell carcinomas (SCC) of the esophagus showed complex numerical and structural abnormalities. Chromosomal bands or regions preferentially involved were 11q13, 8q10, 21q10, 3p10∼p11, 1p11∼q11, 5p11∼q11, and 14p11∼q11. For the first time, to our knowledge, recurrent aberrations were identified in esophageal SCC, including homogenous staining region (hsr), isochromosomes i(3q) and i(21q), and ring chromosome. Losses of chromosomal material dominated over gains. Recurrent imbalances included under-representation of 4p13∼pter, 5q14∼qter, 9p22∼pter, 10p, 11p13∼pter, 12p13∼pter, 17p10∼pter, 18p11∼pter, 21p, and 22p, as well as over-representation of 1q25∼qter, 3q, 7q, and 8q. Interestingly, hsr at different chromosomal regions occurred in three of four cases. With the application of fluorescence in situ hybridization (FISH) and multicolor combined binary ratio labeling–FISH with specific DNA probes, it could be shown that in two cases the hsr was derived from chromosome 11 material and that the amplicon included CCND1. Our results, together with previous molecular genetic findings, indicate that CCND1might be a prime target in 11q13 amplification, and that amplification of this gene might be crucial in the tumorigenesis of esophageal SCC. These observed chromosomal aberrations and imbalances thus provide important information for further molecular genetic investigation of esophageal SCC.