Identification of Chemoresistance-Related Cell-Surface Glycoproteins in Leukemia Cells and Functional Validation of Candidate Glycoproteins

Chemoresistance remains the most
significant obstacle to successful
chemotherapy for leukemia, and its exact mechanism is still unknown.
In this work, we used the cell-surface capturing method together with
quantitative proteomics to investigate differences in the glycoproteomes
of adriamycin-sensitive and adriamycin-resistant leukemia cells. Two
quantitative methods, isotopic dimethyl labeling and SWATH, were used
to quantify glycoproteins, and 35 glycoproteins were quantified by
both methods. High correlation was observed between the glycoproteins
quantified by the above two methods, and 15 glycoproteins displayed
a consistent significant change trend in both sets of quantitative
results. These 15 proteins included classical multidrug resistance-related
glycoproteins such as ABCB1 as well as a set of novel glycoproteins
that have not previously been reported to be associated with chemoresistance
in leukemia cells. Further validation with quantitative real-time
PCR and Western blotting confirmed the proteomic screening results.
Subsequent functional experiments based on RNA interference technology
showed that CTSD, FKBP10, and SLC2A1 are novel genes that participate
in the acquisition and maintenance of the adriamycin-resistant phenotype
in leukemia cells.