Ascertainment of chromosome 7 gains in malignant gliomas by cytogenetic and RFLP analyses.
The incidence of gains involving chromosome 7 was determined independently using cytogenetic and molecular genetic analyses in a series of 57 malignant gliomas. Coincidental results were observed in the group of tumors in which trisomy 7 was identified on the same cells that also displayed other clonal abnormalities (i.e., losses of chromosome 10, and structural rearrangements of 1p, 9p, etc., and the presence of dmin). On the other hand, molecular detection of gain of material from this chromosome was obtained in only one of nine cases in which trisomy 7 had been identified as a solitary anomaly at the cytogenetic level. Thus, although trisomy 7 has been identified as a clonal abnormality in about 60% of gliomas analyzed cytogenetically so far, our findings suggest that the anomaly may be representative of tumor parenchyma in half of them, while in the remaining cases (mainly those in which trisomy 7 is observed at the cytogenetic level as the sole chromosomal deviation) our data agree with those suggesting that the anomaly is the result of an in vitro non-disjunction, or represent in vivo mosaicism of the non-tumoral cells.
Bello
M J
MJ
Instituto de Investigaciones Biomédicas (CSIC), Madrid, Spain.
de Campos
J M
JM
Kusak
M E
ME
Vaquero
J
J
Sarasa
J L
JL
Petaña
A
A
Rey
J A
JA
D015139:Blotting, Southern; D001932:Brain Neoplasms / Q000235:genetics*; D002897:Chromosomes, Human, Pair 7; D005910:Glioma / Q000235:genetics*; D006801:Humans; D012150:Polymorphism, Restriction Fragment Length; D014314:Trisomy