FGFRI AND PLAT GENES AND DNA AMPLIFICATION AT 8P12 IN BREAST AND OVARIAN CANCERS

Several chromosomal regions are found to be consistently amplified in human breast cancers. For two of these regions, 8p12 and 10q26, we pre viously reported the amplification of genes encoding FGF receptors, FG FRI/FLG and FGFR2/BEK, in about 12% of breast tumors. The PLAT gene, e ncoding the tissue-type plasminogen activator, is also located close t o or within the 8p 12 region. In the present study, we show that both FGFRI and PLAT can be amplified in breast as well as ovarian carcinoma s. FGFRI amplification was detected in 14.5% of breast and 7.8% of ova rian tumors, whereas PLAT was found to be amplified in 15.6% and 19.4% of the tumors, respectively. Each gene could be amplified independent ly of the other. These data raised the question of which gene is selec ted for amplification at 8p12. In most cases, the levels of expression of FGFRI and PLAT in breast tumors were comparable to their level of expression in normal mammary tissue. However, FGFRI was expressed abov e the normal level in a certain number of cases. This gene could be a good candidate as ''driver'' of the 8p12 amplification, but it cannot account for all complex molecular events taking place in this region. (C) 1993 Wiley-Liss, Inc.