title: Pediatric glioblastomas: a histopathological and molecular genetic study.
abstract: Glioblastoma multiforme (GBM) occurs rarely in children. Relatively few studies have been performed on molecular properties of pediatric GBMs. Our objective in this study was to evaluate the genetic alterations in pediatric GBM (age < or = 18 years) with special reference to p53, p16, and p27 protein expression, alterations of the epidermal growth factor receptor (EGFR), and deletion of the phosphate and tensin homolog gene (PTEN). Thirty cases of childhood GBMs reported between January 2002 and June 2007 were selected, and slides stained with hematoxylin and eosin were reviewed. Immunohistochemical staining was performed for EGFR, p53, p16, and p27, and tumor proliferation was assessed by calculating the MIB-1 labeling index (LI). Fluorescence in situ hybridization analysis was performed to evaluate for EGFR amplification and PTEN deletion. Histopathological features and MIB-1 LI were similar to adult GBMs. p53 protein expression was observed in 63%. Although EGFR protein overexpression was noted in 23% of cases, corresponding amplification of the EGFR gene was rare (5.5%). Deletion of the PTEN gene was also equally rare (5.5%). One case showed polysomy (chromosomal gains) of chromosomes 7 and 10. Loss of p16 and p27 immunoexpression was observed in 68% and 54% of cases, respectively. In pediatric de novo/primary GBMs, deletion of PTEN and EGFR amplification are rare, while p53 alterations are more frequent compared to primary adult GBMs. Frequency of loss of p16 and p27 immunoexpression is similar to their adult counterparts. This suggests that pediatric malignant gliomas are distinctly different from adult GBMs, highlighting the need for identification of molecular targets that may be adopted for future novel therapeutic strategies.
authors.affiliation: Department of Pathology, All India Institute of Medical Sciences, New Delhi-110029, India.
authors.forename: Vaishali
authors.initials: V
authors.lastname: Suri
authors.forename: Prasenjit
authors.initials: P
authors.lastname: Das
authors.forename: Pankaj
authors.initials: P
authors.lastname: Pathak
authors.forename: Ayushi
authors.initials: A
authors.lastname: Jain
authors.forename: Mehar Chand
authors.initials: MC
authors.lastname: Sharma
authors.forename: Sachin Anil
authors.initials: SA
authors.lastname: Borkar
authors.forename: Ashish
authors.initials: A
authors.lastname: Suri
authors.forename: Deepak
authors.initials: D
authors.lastname: Gupta
authors.forename: Chitra
authors.initials: C
authors.lastname: Sarkar
mesh_terms: D000293:Adolescent; D001932:Brain Neoplasms / Q000235:genetics* / Q000378:metabolism* / Q000473:pathology; D002648:Child; D002675:Child, Preschool; D019941:Cyclin-Dependent Kinase Inhibitor p16 / Q000096:biosynthesis; D066246:ErbB Receptors / Q000235:genetics / Q000378:metabolism; D005260:Female; D015870:Gene Expression; D005909:Glioblastoma / Q000235:genetics* / Q000378:metabolism* / Q000473:pathology; D006801:Humans; D007150:Immunohistochemistry; D017404:In Situ Hybridization, Fluorescence; D007223:Infant; D019394:Ki-67 Antigen / Q000096:biosynthesis; D008297:Male; D051059:PTEN Phosphohydrolase / Q000235:genetics; D018809:Proliferating Cell Nuclear Antigen / Q000096:biosynthesis; D016159:Tumor Suppressor Protein p53 / Q000096:biosynthesis
chemical_list: D019941:Cyclin-Dependent Kinase Inhibitor p16; D019394:Ki-67 Antigen; D018809:Proliferating Cell Nuclear Antigen; D016159:Tumor Suppressor Protein p53; C413374:p27 antigen; D066246:ErbB Receptors; D051059:PTEN Phosphohydrolase; C494929:PTEN protein, human