Correlation between SOX2 and Mutant IDH1 Protein Expression in Astrocytomas and their Clinicopathologic Significance

Abstract
Background: Recent advances in genomic analyses provide a comprehensive view of the tumour-to-tumour complexity of glioma. Subgroups have been defined based on distinct genetic and epigenetic alterations and gene expression profiles. IDH1gene mutation is among the first genetic alterations observed during the development of the glioma. SOX2 is a transcriptional co-factors that are associated with various developmental milestones and is over-expressed in tumours, It plays a role in maintaining pluripotency in several cancers.
Aim of Study: Evaluate the correlation between IHC expression of SOX2 and mutant IDH1 protein in astrocytomas and their clinicopathological significance.
Material and Methods: The study was conducted with 50 patients diagnosed as Astrocytomas at the pathology laboratory, Suez Canal University Hospital between 2003 to 2015. The clinicopathological data were obtained from medical records Each case was studied for IHC expression of SOX2 and mutant IDH1(R132H antibody) and correlate expression results with variable clinicopathological features.
Results: A statistically significant correlation between the expression of SOX2 and mutant IDH1 protein in astrocytomas and their expressions and grades of astrocytoma as, Glioblas-toma multiform (GBM) showed prominent expression of (SOX2 and mutant IDH1 protein) than other astrocytoma grades. A statistically significant relation between mutant IDH1 protein expression and tumour location with more expression among a tumour at the frontal lobe but no a statistically significant relation between SOX2 expression and tumour location. A higher SOX2 expression was among female patients compared to male patients, with a statistically significant correlation. No a statistically significant correlation between the expression of mutant IDH1 protein and gender. No a statistically significant correlation between the expression of both SOX2 & mutant IDH1 protein and age of the studied patients. A positive relationship between the expression of SOX2 and mutant IDH1 protein in the astrocytomas.
Conclusion: Expression of SOX2 and mutant IDH1 protein in astrocytomas mainly GBM suggest a role in tumour invasion and dedifferentiation of tumour cells in astrocytomas.