CHROMOSOME MICRODISSECTION IDENTIFIES CRYPTIC SITES OF DNA-SEQUENCE AMPLIFICATION IN HUMAN OVARIAN-CARCINOMA

DNA sequence amplification contributes to the multistep process of car cinogenesis, and overexpression of amplified genes has been shown to c ontribute to the malignant phenotype. Cytogenetic analyses of human tu mor cells, including ovarian malignancies, frequently show cytological evidence of DNA amplification in the form of double minutes and homog eneously staining regions. In this report, we have combined the techni ques of chromosome microdissection and fluorescence in situ hybridizat ion (P. S. Meltzer et al., Nat. Genet., 1: 24-28, 1992) to identify th e composition and chromosomal origin of seven homogeneously staining r egions from seven cases of ovarian cancer. Twelve specific chromosome band regions were identified as amplified including 11q, 12p, 16p, 19p , and 19q. These results provide important insights into the organizat ion of amplified sequences within ovarian malignancies and add further to our recognition of regions likely to harbor genes important to the development or progression of ovarian cancer.