GRANULOCYTIC-COLONY STIMULATION FACTOR (G-CSF) REALLY SUGGESTS ROLE OF VITAMIN E (ALPHA-TOCOPHEROL) AS A NEW POTENTIAL CANDIDATE FOR DIFFERENTIATION THERAPY IN CML BLAST CELLS

Shvachko L. P.*, Gartovska I. R. and Telegeev G. D.

ABSTRACT

Background: Chronic myeloid leukemia (CML) is a clonal, bone marrow hematopoietic stem cells (HSCs) disorder which characterised by the blocking myeloid differentiation resulting to uncontrolled immature blast cell progression. CML blast crisis does not find effective treatment of BCR-ABL tyrosine kinase inhibitors (TKI) as imatinib. Therefore, differential therapies of CML blast cells can be alternative to TKI therapy and complement it. Granulocyt-colony stimulated factor (G-CSF) is growth factor, the major cytokine regulator of G-CSF-induced hematopoietic stem/progenitor mobilization. Accumulating evidence shows the pivotal role of granulocyte colony-stimulating factor (G-CSF) in the development of HSC progenitors in the common myeloid pathway in part for terminal neutrophil granulopoiesis. The Aim: of the present research is to research the differentiation potential of vitamin E in parallel the role of G-CSF in re-activation of some key factors of myelopoiesis in K562 CML blast crisis cells in vitro. Along with differentiation factors as C/EBP α (CCAAT/enhancer binding protein alpha), TNAP (tissue non-specific alkaline phosphatase or neutrophil alkaline phosphatase) and general tissue cell E-cadherin has been focused the modulation of some key leukemic stemness transcription factors as SNAIL, OCT4 and LSC-associated factor PLAP (placental-like alkaline phosphatase) by vitamin E in parallel with G-CSF in K562 CML blast crisis cells in vitro. The Methods of qRT-PCR: are using for assay mRNA gene expression levels of myeloid master regulator C/EBPα (CCAAT/enhancer binding protein alpha), neutrophil-granulocytic factor TNAP (tissue non-specific alkaline phosphatase) and general differentiation tissue cell-specific factor E-cadherin in the study of myeloid differentiation potential of CML blast cells K562 exposed by vitamin E(100 µM) and G-CSF (Filgrastim, 1µg/ml, 100 000 MU) under 72 h CO2 incubation. Also has been study the mRNA gene expression levels of leukemic stem cells biomarkers as SNAIL, OKT4 and LSC-associated factor PLAP. The Results: We have suggested that both vitamin E and G-CSF observed the stimulation role for differentiation potential K562 CML blast cells by up-regulation of myeloid master regulator C/EBPα, neutrophil alkaline phosphatase TNAP and general tissue cell differentiation factor E-cadherin gene mRNA expression. Moreover, both vitamin E and G-CSF observed the repression role for leukemic stemmness phenotype in K562 CML blast cells by down-regulation of LSC-associated biomarkers as EMT-inducer SNAIL transcription factor, OKT4 pluripotent transcriptin factor and PLAP, tumor-associated placental-like alkaline phosphatase, on the relative levels of gene mRNA expression. The Conclusion: We have emphasized the reverse interrelationship between leukemic stemness cell markers SNAIL, OCT4 and PLAP and myeloid differentiated markers C/EBPα, TNAP and E-cadherin gene expression by vitamin E and G-CSF modulation in K562 CML blast cells in vitro.

Keywords: Chronic myeloid leukemia, K562 CML blast crisis leukemic culture model, myeloid differential therapy, G-CSF (granulocyt-colony stimulated factor), vitamin E (alpha-tocopherol).