Elevated mRNA level of hST6Gal I and hST3Gal V positively correlates with the high risk of pediatric acute leukemia

Abstract 

Altered sialylation occurs in essentially all types of human and experimental cancers. Although, aberrant sialylation is believed to mainly due to altered sialyltransferase (ST) level, so far, expression pattern of different STs in acute lymphoblastic leukemia has never been investigated. Accordingly, the aim of our study was to monitor the changes in mRNA expression of ST6Gal I, ST3Gal V and ST8Sia I in patients by real-time PCR, which may provide prognostic information useful in defining appropriate therapeutic options. Our data demonstrated that ST6Gal I and ST3Gal V mRNA were up-regulated in lymphoblasts whereas its presence was negligible in non-malignant donors. In contrast, ST8SiaI was downregulated in patients. The extents of linkage-specific sialylation of glycoconjugates were found to be associated with disease establishment. Additionally, ST6Gal I and ST3Gal V were positively correlated with the high risk of the disease (P=0.0032 and 0.0016). This differential ST level can be used as biomarker with the molecular method of quantitative PCR and may be useful to discriminate normal and cancer patients.

Abbreviations: ALL, acute lymphoblastic leukemia, BM, bone marrow, BSM, bovine submandibular mucin, CMP, cytidine monophosphate, Ct, cycle threshold, DEPC, diethyl pyrocarbonate, dNTPs, deoxyribonucleotide triphosphates, Neu5Ac, sialic acid, PB, peripheral blood, SNA, Sambucus nigra agglutinin, ST, sialyltransferase, TLC, thin layer chromatography

Keywords: Childhood acute lymphoblastic leukemia, mRNA, Real-time PCR, Siglec, Ganglioside, Risk factor