[Effect of FLT3-ITD Length on 32D Cell Proliferation, Apoptosis and Sensitivity to FLT3 Inhibitor].

Objective To study the effects of FLT3-ITD length on 32D cell proliferation, apoptosis and sensitivity to FLT3 inhibitor, so as to provide references for stepwise therapy of FLT3-ITD mutated acute myeloid leukemia patients. Methods Three different FLT3-ITD mutants with same or adjacent insert sites were selected and constructed in an eukaryotic expression vector. FLT3-ITD mutants stably expressed 32D cell strains were selected with the help of lentivirus system and IL3 free cell culture medium. The proliferation and apoptosis of 32D cell strains after AC220 treatment were detected. Results FLT3-ITD mutants (ITD1, ITD2 and ITD3) stably expressed 32D cell strains were constructed successfully. In the absence of IL3 factor, the proliferation number of ITD1, ITD2 and ITD3 cell strains were mounted up to 2.3 folds, 3.7 folds, and 4.3 folds after 48 hours, respectively. Under the exposure of FLT3 inhibitor AC220, the IC50 values was 0.183, 0.446 and 0.836 nmol/L, and apoptosis rates was 88.6%, 34.2% and 16.1%, respectively. Conclusion FLT3-ITD mutant expressed cell strains with longer ITD show higher capacity of proliferation and higher tolerance to AC220 treatment.