Combined comparative genomic hybridization and genomic microarray for detection of gene amplifications in pulmonary artery intimal sarcomas and adrenocortical tumors

Identification of gene amplifications in human tumors is important for the understanding of tumorigenesis and may lead to discovery of diagnostic and prognostic markers. In this study, we used a microarray-based comparative genomic hybridization (CGH) technique, combined with conventional CGH, to identify gene amplifications in 43 tumors including eight pulmonary artery intimal sarcomas and 35 adrenocortical tumors. Conventional CGH revealed gains or amplifications of 12q13-q15 in six sarcomas and in two adrenocortical carcinomas. Using microarrays, we demonstrated that, among genes located on 12q13-q15, SAS/CDK4 were amplified in six sarcomas, and MDM2 and GLI in five and four sarcomas, respectively. The two adrenocortical tumors showed coamplifications of SAS/CDK4 and MDM2. Furthermore, PDGFRA (located on 4q12) amplification was identified in five sarcomas. Our data demonstrate: (1) amplifications of SAS/CDK4, MDM2, GLI, and PDGFRA are strongly associated with the tumorigenesis of pulmonary artery intimal sarcomas, whereas SAS/CDK4 and MDM2 coamplification may contribute to the progression of adrenocortical tumors; (2) microarray-based CGH is a useful tool for simultaneous detection of multiple gene amplifications, with a high sensitivity and resolution compared to that of conventional CGH.