HIF-1a and GLUT-1 Expression in Atypical Endometrial Hyperplasia, Type I and II Endometrial Carcinoma: A Potential Role in Pathogenesis EC20-EC27
Dr. Dalia Rifaat Al-Sharaky,
Lecturer, Department of Pathology Faculty of Medicine, Menoufia University Shibeen El Koom,
32817 Menoufiya Governorate, Egypt.
Introduction: Hypoxia-Inducible Factor 1a (HIF-1a) is one of the major adaptive responses to hypoxia, regulating the activity of glucose transporter -1 (GLUT-1), responsible for glucose uptake.
Aim: To evaluate the immunohistochemical expression of both HIF-1a and GLUT-1 in type I and II endometrial carcinoma and their correlation with the available clinicopathologic variables in each type.
Materials and Methods: A retrospective study was conducted on archival blocks diagnosed from pathology department between April 2010 and August 2014 included 9 cases of atypical hyperplasia and 67 cases of endometrial carcinoma. Evaluation of both HIF-1a and GLUT-1 expression using standard immunohistochemical techniques performed on cut sections from selected paraffin embedded blocks.
Statistical Analysis: Descriptive analysis of the variables and statistical significances were calculated by non-parametric chi-square test using the Statistical Package for the Social Sciences version 12.0 (SPSS).
Results: HIF-1a was expressed in epithelial (88.9%, 52.2%, 61.2% and 50%) and stromal (33.3%, 74.6%. 71.4% and 83.3%) components of hyperplasia, total cases of EC, type I and II EC, respectively. GLUT-1 was expressed in the epithelial component of 88.9%, 98.5%, 98% and 100% of hyperplasia, total EC cases, type I and II EC, respectively. The necrosis related pattern of epithelial HIF-1a expression was in favour of type II (p=0.018) and grade III (p=0.038). HIF-1a H-score was associated with high apoptosis in both type I and total cases of EC (p=0.04). GLUT-1 H-score was negatively correlated with apoptotic count (p=0.04) and associated with high grade (p=0.003) and advanced stage in total EC (p=0.004). GLUT-1 H-score was correlated with the pattern of HIF-1a staining in all cases of EC (p= 0.04).
Conclusion: The role of HIF-1a in epithelial cells may differ from that of stromal cells in EC; however they augment the expression of each other supporting the crosstalk between them. The stepwise increase in H- score of GLUT-1 in the studied cases implies its potential role in carcinogenesis of EC. HIF-1a may promote GLUT-1 expression in EC especially surrounding areas of necrosis. The differences between type I and type II EC regarding HIF-1a and GLUT-1 expression may confirm the differences in their aetiopathogenesis.