Significance of GRP78 expression in acute myeloid leukemias

Abstract

The GRP78 (glucose-regulated protein 78) is a major endoplasmic reticulum (ER) chaperone facilitating proper folding of the newly synthesized proteins. By the interaction with caspases, GRP78 has antiapoptotic properties allowing cells to survive under stress condition. GRP78 expression and its association with tumor proliferation, metastasis and resistance to chemotherapy were observed in solid tumors. There are limited data on the expression and impact of this protein on the clinical course and treatment response in acute myeloid leukemia (AML). The aim of this study was to evaluate the expression of GRP78 mRNA in patients with de novo AML. These results were compared to healthy controls, blast phenotype, molecular and cytogenetic status and clinical features of AML. 101 non-M3 AML patients and 26 healthy individuals were included in this study. The expression of GRP78 mRNA in bone marrow was analyzed by real-time quantitative polymerase chain reaction (RQ-PCR). We demonstrated increased GRP78 mRNA expression in AML patients compared to healthy controls, although this difference was statistically significant only in CD34+ leukemias. There was also no significant correlation between GRP78 mRNA expression and complete remission rate, relapse-free survival and overall survival. These results indicate that GRP78 expression is increased in CD34 + leukemias and has no prognostic impact on clinical outcome in AML. © 2014 Versita and Springer-Verlag.