A new approach of brain tumors: the cytogenetic study

Cytogenetic studies of brain tumors in adults have made it possible to determine specific chromosomal abnormalities and to detect a high incidence of gene amplification related to these abnormalities. Data from the literature and our own results show frequent numerical deviations in glioblastomas, such as gain of chromosome 7, but also 19, 20 and X, loss of certain chromosomes: monosomies 6, 14 and 22. Most of the structural abnormalities are deletions involving the chromosomal regions 1p, 6q, 7q and 9p, and the presence of double-minutes (DMs), the latter being the chromosomal expression of EGFR gene amplification. Cytogenetic analysis of meningiomas has shown that some of them have monosomy 22 alone while others have additional abnormalities. Antioncogenes probably play a part in these tumors. Their identification will explain the neuro-oncogenesis process and perhaps open a new route for the treatment of brain tumors.