title: [Correlation between loss of heterozygosity on chromosome 1p and 19q and expression of MGMT, p53 and Ki-67 proteins in gliomas].
abstract: OBJECTIVE
  To study the correlation of loss of heterozygosity (LOH) on chromosome 1p and 19q with the expression of MGMT, p53 and Ki-67 proteins in gliomas.
  
  
  METHODS
  One hundred and forty six cases of gliomas (45 oligodendrogliomas, 42 oligodendroastrocytomas, and 59 astrocytomas) were included in this study. Their tissue and blood samples were retrospectively analyzed by PCR-denaturing high-performance liquid chromatography (DHPLC) for 1p and 19q status and by immunohistochemistry for MGMT, p53 and Ki-67 expression patterns. The correlation among them and with clinicopathological characteristics were analyzed by chi-square test and t-test.
  
  
  RESULTS
  In the oligodendrogliomas, the positive rate of 1p LOH was 59.8%, significantly higher than 33.9% in astrocytomas (P = 0.002), and 1p and 19q LOH was 42.5%, significantly higher than 16.9% in astrocytomas (P = 0.001). Combined with LOH on 1p and 19q, low MGMT expression (65.5%), and high Ki-67 expression (54%) were more frequent in oligodendrogliomas, whereas high p53 expression was more frequent in astrocytomas and mixed tumors (75.2%). 1p LOH (72.5%) and low MGMT (87.5%) expressions were more frequent in grade II oligodendrogliomas, whereas high expressions of p53 (83.0%) and Ki-67 (76.6%) were more frequent in grade III oligodendrogliomas. In addition, high Ki-67 expression was more frequent in grade III astrocytomas. LOH on 1p and 19q LOH was more frequent in nontemporal oligodendrogliomas (55.6%) than that in temporal ones (22.2%, P = 0.002). Non-random associations were found between LOH 1p and 19q LOH, MGMT and p53 protein expressions, and MGMT and Ki-67 protein expressions (all P < 0.05), whereas mutual exclusions were found between LOH on 1p and 19q and p53 expression, and LOH 1p and Ki-67 expression.
  
  
  CONCLUSIONS
  There is a significant interrelationship of the investigated molecular markers and clinicopathological features of gliomas, which support a promising role of molecular markers in guiding diagnostic assessment and clinical management of gliomas.
authors.affiliation: Department of Neurosurgery, Beijing Tiantan Hospital, Capital Medical University, Beijing 100050, China.
authors.forename: Lei
authors.initials: L
authors.lastname: Huang
authors.forename: Tao
authors.initials: T
authors.lastname: Jiang
authors.forename: Fang
authors.initials: F
authors.lastname: Yuan
authors.forename: Gui-lin
authors.initials: GL
authors.lastname: Li
authors.forename: Li-xin
authors.initials: LX
authors.lastname: Xu
authors.forename: Yun
authors.initials: Y
authors.lastname: Cui
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D001254:Astrocytoma / Q000235:genetics / Q000378:metabolism / Q000473:pathology; D001932:Brain Neoplasms / Q000235:genetics / Q000378:metabolism / Q000473:pathology; D002648:Child; D002878:Chromosomes, Human, Pair 1 / Q000235:genetics*; D002888:Chromosomes, Human, Pair 19 / Q000235:genetics*; D005260:Female; D005910:Glioma / Q000235:genetics / Q000378:metabolism / Q000473:pathology; D006801:Humans; D019394:Ki-67 Antigen / Q000378:metabolism*; D019656:Loss of Heterozygosity; D008297:Male; D008875:Middle Aged; D019853:O(6)-Methylguanine-DNA Methyltransferase / Q000378:metabolism*; D009837:Oligodendroglioma / Q000235:genetics / Q000378:metabolism / Q000473:pathology; D012189:Retrospective Studies; D016159:Tumor Suppressor Protein p53 / Q000378:metabolism*; D055815:Young Adult
chemical_list: D019394:Ki-67 Antigen; C495901:TP53 protein, human; D016159:Tumor Suppressor Protein p53; D019853:O(6)-Methylguanine-DNA Methyltransferase