Characterization of IGFI Receptor Expression and Localization in Paediatric Gliomas Upon Diagnosis According to WHO 2007 Grading

CLEMENT, FLORENCIA; VENARA M; MAGLIO, SILVANA; MARTÍN, AYELEN; MATHO, CECILIA; PETRE, C; GARCIA LOMBARDI, M; BERGADA, I; PENNISI PATRICIA A

Dublin

Congreso; ESPE 2014, 53rd Annual European Society For Paediatric Endocrinology Meeting; 2014

European Society For Paediatric Endocrinology ESPE

Background: Gliomas are the most common subgroupof CNS tumours in children. Histologic grading is a means ofpredicting the biological behavior of these tumours and survival isstrongly correlated with tumour gradation. The IGF system ofligands and receptors are known to play an important role in bothnormal and neoplastic growth. Recently, nuclear translocationof the type 1 IGF1R has been demonstrated in tumour tissues.Although the IGF1R expression has been described in CNSpaediatric tumours, information about the intracellular localizationand correlation with tumour grade is lacking. Objectiveand Hypotheses: To characterize the expression and intracellularlocalization of the IGFI receptor in glial tumours from paediatricpatients according to WHO 2007 grading. Method: Twenty-twopatients (12 males/ten females), median aged 7.7 years, (range0.9?18.2), with gliomas without previous medical treatment wereincluded. Formalin-fixed 5 mm tumour tissue sections wereimmunostained for IGF1Rb. IGF1R expression and intracellularlocalization were scored as positive or negative, nuclear orcytoplasmic respectively. Contingency tables were analyzed usingPearson?s c2 test to assess relationships between IGF1R andtumour grade (low grades I?II and high grades III?IV). Results:IGF1R staining was positive in 11/17 (65%) low grade tumoursand in 4/5 (80%) high grade tumours. Low grade tumoursshowed cytoplasmic localization of IGF1R in 8/11 cases, while inhigh grade tumours IGF1R localization was mainly nuclear (3/4)(c2 test: P!0.05). Conclusion: Our results would indicate thatboth expression and intracellular localization of the IGF1R aredifferent in low vs high grade glial paediatric tumours, suggesting apotential role for the IGF system in the biological behavior of thesetumours. Further studies are necessary to confirm our results.