Analysis of Cytogenetic Abnormalities in Squamous Cell Carcinoma by Array Comparative Genomic Hybridization

Abstract

Introduction Few conventional cytogenetic studies of squamous cell carcinoma (SCC) have been performed to date. The introduction of cytogenetic techniques such as comparative genomic hybridization (CGH) has resolved some of the problems associated with conventional cytogenetics. The aim of this study was to analyze the presence of genetic abnormalities in a series of patients with SCC using the technique of array CGH. Material and methods The study included 8 patients (7 men and 1 woman; mean age, 75 years) diagnosed with primary SCC. DNA was extracted from frozen tissue and analyzed by array CGH. Results All cases had genetic alterations, with gains more frequent than losses. The chromosomal regions with gains, in descending order of frequency, were as follows: 5p15.2, 9q31.3-q33.2, 13q, 18q22, 1p21-p22, 1q24-q25, 3p13, 4q33-q34 ( HMGB2, SAP30), 20p12.2 ( JAG1), 21q21.1, and Xq21.33. The region 9p13.1-p13.3 was the only one to display recurrent loss. No correlation was observed between the presence of gains or losses and the clinical and pathologic characteristics of the tumors. Conclusions This is the first study to use the technique of array CGH to analyze genetic alterations in SCC. The finding of certain previously described aberrations (gain of 5p) suggests the existence of recurrent abnormalities. Likewise, the observation of alterations in small regions of chromosome 1 highlights the sensitivity of the technique to detect small changes. Application of the technique to a larger series of cases will provide greater insight into the genetic abnormalities implicated in the process of tumorigenesis in SCC.