| Objective: To investigate the differential expression of glycogenes betweendrug-resistant K562/ADR cells and parental K562line, and to clarify the correlation ofglycogenes and multidrug resistance of human leukemia. To further predict anddiagnose leukemia multidrug resistance, and provide a new therapeutic strategy andtarget point of leukemia.Methods:(1) Using real-time PCR for quantification of glycogenes, we compared thedifferential expression (i.e.,>3-fold higher) of glycogenes in drug-resistant K562/ADRcells with parental K562line. Characteristic alteration of glycogenes in multidrugresistance of human leukemia is explored firstly.(2) Using FITC-lectin binding for glycan profiling, and mass spectrometry forglycan composition, we compared the glycan profiling and N-glycan composition ofdrug-resistant K562/ADR cells with parental K562line.(3) Using RNA interference approach for silencing the glycogenes, wereover-expressed in K562/ADR cells to detect the chemosensitivity to anti-tumor drugs invitro. The effect of altered expression of glycogenes to leukemia multidrug resistancewas also observed.(4) Further analysis of the N-glycan regulation by way of tunicamycin applicationor PNGase F treatment, P-gp and CD147were analyzed by way of western blot. Thechemosensitivity were examed by MTT. The effect of modification of N-glycosylationto leukemia multidrug resistance was also observed.Results:(1)12genes (i.e.,>3-fold higher) were differentially expressed between the twoleukemic cell lines, K562and K562/ADR. High expressions of glycogene arecorresponding with high fluorescence intensity of lectins in both cell lines. TheN-glycan compositions were different in K562/ADR cells, as compared with those in K562cells.(2) The silencing of glycogene B3GNT8or ST8SIA4in K562/ADR cells resultedin increased chemosensitivity to anti-tumor drugs (P<0.05).(3) The analysis of the N-glycan regulation by way of tunicamycin application orPNGase F treatment in K562/ADR cells showed partial inhibition of biosynthesis andincreased sensitivity to chemotherapeutic drugs in vitro.Conclusion:(1) The expression of glycogenes, glycan profiling and N-glycan composition weredifferent in K562/ADR cells, as compared with those in K562cells. These characteristicalterations are associated with multidrug resistance in human leukemia.(2) The altered expression of glycogenes and modification of N-glycosylation inhuman leukemia correlate with multidrug resistance, and have significant implicationsfor the development of treatment strategies. |
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