Identification of Glycan Structure Alterations on Cell Membrane Proteins in Desoxyepothilone B Resistant Leukemia Cells

Abstract

Resistance to tubulin-binding agents used in cancer is often multifactorial and can include changes in drug accumulation and modified expression of tubulin isotypes. Glycans on cell membrane proteins play important roles in many cellular processes such as recognition and apoptosis, and this study investigated whether changes to the glycan structures on cell membrane proteins occur when cells become resistant to drugs. Specifically, we investigated the alteration of glycan structures on the cell membrane proteins of human T-cell acute lymphoblastic leukemia (CEM) cells that were selected for resistance to desoxyepothilone B (CEM/dEpoB). The glycan profile of the cell membrane glycoproteins was obtained by sequential release of N-and O-glycans from cell membrane fraction dotted onto polyvinylidene difluoride membrane with PNGase F and ␤-elimination respectively. The released glycan alditols were analyzed by liquid chromatography (graphitized carbon)-electrospray ionization tandem MS. The major N-glycan on CEM cell was the core fucosylated ␣2-6 monosialo-biantennary structure. Resistant CEM/dEpoB cells had a significant decrease of ␣2-6 linked sialic acid on N-glycans. The lower ␣2-6 sialylation was caused by a decrease in activity of ␤-galactoside ␣2-6 sialyltransferase (ST6Gal), and decreased expression of the mRNA. It is clear that the membrane glycosylation of leukemia cells changes during acquired resistance to dEpoB drugs and that this change occurs globally on all cell membrane glycoproteins. This is the first identification of a specific glycan modification on the surface of drug resistant cells and the mechanism of this downstream effect on microtubule targeting

Alpha-2, 3-sialyltransferases regulate the multidrug resistance of chronic myeloid leukemia through miR-4701-5p targeting ST3GAL1

“…22,23 Remodeled mRNA expression of a panel of STs in human breast cancer, cervical cancer, ovarian cancer, and acute lymphoblastic leukemia has been documented. 4,8,24,25 Here, the expression profiles of ST3GAL gene family were shown to be remodeled in three pairs of CML cell lines with real-time PCR and western blot analysis. All parent cells KCL22, K562, and KU812 were characterized by higher levels of ST3GAL1 and ST3GAL5, whereas MDR cells expressed more ST3GAL4.…”

“…The changes of glycans attached on cell glycoproteins have been linked to drug resistance in leukemia. 3,4 Therefore, much attention has been paid on regulation of glycosyltransferases in an effort to overcome MDR in the treatment of CML.…”

In-depth research of multidrug resistance related cell surface glycoproteome in gastric cancer

“…Previously, we have found several proteins (PrP(C), p75(NTR), GAS1 and RhoE) that play important roles in MDR of gastric cancer, which unfortunately, are not sufficient enough to elucidate the development of MDR [11][12][13][14]. Recently, the correlation between drug resistance and change of glycoproteins has been reported in several papers [9,10,32,33]. But currently, there is no report concerning the relation between alteration of glycoproteins and MDR in Fig.…”

Simple Capillary Electrophoresis–Mass Spectrometry Method for Complex Glycan Analysis Using a Flow-Through Microvial Interface

“…5,65,66 However, those additional steps can eliminate subtle modifications including O-acetylation present in glycans (unpublished observation). Therefore, the analysis of underivatized species is the preferred method of choice to preserve the structural characteristics of these complex analytes.…”