title: Expression pattern and prognostic significance of IGFBP isoforms in anaplastic astrocytoma.
abstract: The role of insulin-like growth factors and their regulatory proteins (IGFBP isoforms) in gliomas, particularly glioblastoma, has been a subject of active research in recent years. There is paucity of literature on their expression and impact on clinical outcome in anaplastic astrocytomas. To evaluate the expression patterns of IGFBP isoforms in anaplastic astrocytoma and correlate with clinical outcome, a retrospective study of 53 adult patients operated for supratentorial lobar anaplastic astrocytoma was performed. The protein expression of IGFBP isoforms (IGFBP-2, -3, -5 and -7), was studied by immunohistochemistry on all samples. The patients were followed up and outcome was documented. The median age at presentation in the present study was 35 years. The pattern of staining was intra cytoplasmic, homogenous and diffuse for IGFBP-2, -3 and -5 and granular for IGFBP-7. IGFBP-2 expression was significantly low in anaplastic astrocytoma as compared to other isoforms (P < 0.001). IGFBP-3 expression was higher than the other isoforms. However, its' expression correlated with favorable overall survival and demonstrated a trend towards significance on univariate analysis. The present study is the first of its kind to describe comprehensively the pattern of expression of IGFBP isoforms (IGFBP-2, -3, -5 and -7) in anaplastic astrocytomas. IGFBP-2 and IGFBP-3 expression patterns and correlation to prognosis were distinct in anaplastic astrocytoma patients, contradictory to what has been reported in glioblastoma, thus giving further evidence that anaplastic astrocytomas are molecularly distinct from glioblastoma.
authors.affiliation: Department of Neurosurgery, National Institute of Mental Health and Neurosciences, Bangalore, India.
authors.forename: A
authors.initials: A
authors.lastname: Kulkarni
authors.forename: B
authors.initials: B
authors.lastname: Thota
authors.forename: M R
authors.initials: MR
authors.lastname: Srividya
authors.forename: K
authors.initials: K
authors.lastname: Thennarasu
authors.forename: A
authors.initials: A
authors.lastname: Arivazhagan
authors.forename: V
authors.initials: V
authors.lastname: Santosh
authors.forename: B A
authors.initials: BA
authors.lastname: Chandramouli
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000704:Analysis of Variance; D001254:Astrocytoma / Q000737:chemistry / Q000378:metabolism* / Q000473:pathology; D001932:Brain Neoplasms / Q000737:chemistry / Q000378:metabolism* / Q000473:pathology; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D018969:Insulin-Like Growth Factor Binding Proteins / Q000378:metabolism*; D053208:Kaplan-Meier Estimate; D008297:Male; D008875:Middle Aged; D011379:Prognosis; D020033:Protein Isoforms; D012189:Retrospective Studies
chemical_list: D018969:Insulin-Like Growth Factor Binding Proteins; D020033:Protein Isoforms