Incidence of numerical chromosome aberrations in meningioma tumors as revealed by fluorescence in situ hybridization using 10 chromosome-specific probes.
OBJECTIVE
Although information on the cytogenetic characteristics of meningioma tumors has accumulated progressively over the past few decades, information on the genetic heterogeneity of meningiomas is still scanty. The aim of the present study was to analyze by interphase fluorescence in situ hybridization (FISH) the incidence of numerical abnormalities for chromosomes 1, 9, 10, 11, 14, 15, 17, 22, X, and Y in a group of 70 consecutive meningioma tumors. Another goal was to establish the potential associations among the altered chromosomes, as a way to assess both intertumoral and intratumoral heterogeneity.


METHODS
For the purpose of the study, 70 patients diagnosed with meningioma were analyzed. Interphase FISH for the detection of numerical abnormalities for chromosomes 1, 9, 10, 11, 14, 15, 17, 22, X, and Y was applied to fresh tumor samples from each of the patients studied.


RESULTS
The overall incidence of numerical abnormalities was 76%. Chromosome Y in males and chromosome 22 in the whole series were the most common abnormalities (46% and 61%, respectively). Despite the finding that monosomy of chromosome 22/22q(-) deletions are the most frequent individual abnormality (53%), we have observed that chromosome gains are significantly more common than chromosome losses (60% versus 40%). Chromosome gains corresponded to abnormalities of chromosomes 1 (27%), 9 (25%), 10 (23%), 11 (22%), 14 (33%), 15 (22%), 17 (23%), and X in females (35%) and males (23%) whereas chromosome losses apart from chromosome 22 frequently involved chromosomes 14 (19%), X in males (23%), and Y in males (32%). Although an association was found among most gained chromosomes on one side and chromosome losses on the other side, different association patterns were observed. Furthermore, in the latter group, monosomy 22/22q(-) was associated with monosomy X in females and monosomy 14/14q(-) was associated with nulisomy Y in males. In addition, chromosome losses usually involved a large proportion of the tumor cells whereas chromosome gains were restricted to small tumor cell clones, including tetraploid cells.


CONCLUSIONS
Our results show that meningiomas are genetically heterogeneous tumors that display different patterns of numerical chromosome changes, as assessed by interphase FISH.
Sayagués
José María
JM
Servicio General de Citometría, Departmento de Medicina y Centro de Investigaciones del Cáncer, Universidad de Salamanca, Paseo de San Vicente, 58-182 37007 Salamanca, Spain.
Tabernero
María Dolores
MD
Maillo
Angel
A
Díaz
Pedro
P
Rasillo
Ana
A
Bortoluci
Aglae
A
Gomez-Moreta
Juan
J
Santos-Briz
Angel
A
Morales
Francisco
F
Orfao
Alberto
A
D000293:Adolescent; D000368:Aged; D002869:Chromosome Aberrations / Q000145:classification / Q000706:statistics & numerical data; D002877:Chromosomes, Human; D015342:DNA Probes; D005260:Female; D006801:Humans; D017404:In Situ Hybridization, Fluorescence / Q000379:methods*; D015994:Incidence; D008297:Male; D008577:Meningeal Neoplasms / Q000175:diagnosis / Q000235:genetics* / Q000473:pathology; D008579:Meningioma / Q000175:diagnosis / Q000235:genetics* / Q000473:pathology
D015342:DNA Probes