ABSTRACT
Aim To reveal the underlying mechanisms of the co-occurrence of ASXLI and JAK2ymr mutation by using human leukemia cell line HEL that carried homozygous /4A2V617F mutation in the elucidation of the role of ASXLI loss of function mutation in myeloproliferative neoplasms, so as to provide an important model for investigating the role of ASXLI mutation in myeloproliferative neoplasms at the cellular level. Methods HEL cell line with ASXLI knockout ( HEL-AKO) was established by using CRISPR/Cas9-mediated gene editing. And a series experiments based were preformed to verify the effect of ASXLI on HEL cell proliferation, clone formation and chemosensitivity. Results HEL-AKO cell line was successfully established, confirmed by sequencing results. We found that the loss of ASXLI could inhibit proliferation and induce cell cycle arrest at the G2/M phase. The colony-form- ing capacity of HEL-AKO cells was also markedly inhibited. Moreover, the HEL-AKO had higher cloning efficiency than HEL Control after ruxolitinib treatment. Conclusions Loss of function of ASXLI has an impact on cell biological function of HEL. Therefore, HEL- AKO cell line can be used to further explore the biological contribution of concomitant ASXLI in /4A2V617F mutated MPN.
ABSTRACT
Aim To explore the cytotoxic and synergistic effects of decitabine and ruxolitinib on HEL cells with TET2 knockdown. Methods Stable TET2 knockdown by shRNA was established in HEL cell line. The change of cell proliferation was measured by CCK-8 assay. The median lethal dose (IC50) and colony formation assay were used to evaluate the cytotoxic effects of decitabine and ruxolitinib, the synergistic effects of which was further analyzed by Chou-Talalay method. Results The inhibition of TET2 increased the proliferative capacity of HEL cells. HEL cell lines became resistant to decitabine following shRNA-media- ted TET2 inactivation. Colony formation assay showed that the drug sensitivity of decitabine and ruxolitinib both decreased in TET2 knockdown HEL cells. The synergistic inhibitory effects of ruxolitinib and decitabine on TET2 knockdown HEL cells were observed. Conclusion The combination of ruxolitinib and decitabine may be an effective therapeutic strategy for accelerated or blast phase MPN patients with JAK2V6m and TET2 mutations.