ABSTRACT
<p><b>OBJECTIVE</b>To investigate the relationship between cyclin D2 and P210(BCR/ABL) tyrosine kinase in chronic myelogenous leukemia (CML).</p><p><b>METHODS</b>RT-PCR, Western blot and flow cytometry were performed to detect the expression of cyclin D2 in K562 cells and in K562-ib-eGFP cells which express intracellular single-chain antibody (sFv, intrabody) against ABL tyrosine kinase domain.</p><p><b>RESULTS</b>Cyclin D2 expression in K562-ib-eGFP cells was 18.90% which was lower than that of control K562 cells (48.10%), and the number of S-phase cells in K562-ib-eGFP was 40.40% which was much lower than that in K562 cells (64.34%).</p><p><b>CONCLUSION</b>Cyclin D2 is a potential down-stream signal molecule of the p210(BCR/ABL) tyrosine kinase in CML. The altered expression of cyclin D2 may contribute to the over proliferation of CML cells.</p>
Subject(s)
Humans , Blotting, Western , Cyclin D2 , Cyclins , Genetics , Flow Cytometry , Genes, abl , K562 Cells , Leukemia, Myelogenous, Chronic, BCR-ABL Positive , Metabolism , Reverse Transcriptase Polymerase Chain ReactionABSTRACT
<p><b>OBJECTIVE</b>To develop an in vitro assay that allows the culture and identification of a single human bone marrow progenitor closely related to hematopoietic stem cell, which is more primitive than LTC-IC, and to find an efficient culture conditions for NK-IC expansion.</p><p><b>METHODS</b>Fusion protein IL6/IL2 was reconstructed and expressed in E. coli DH5 alpha. ML-IC was determined by watching if the single cell can give rise to secondary progenitors with both LTC-IC and NK-IC characteristics. LTC-IC frequency was determined by the CFC clonogenic methylcellulose assay. NK-IC frequency was determined by phenotyping CD56 positive NK cells. The effect of FPIL6/IL2 on the expansion of NK-IC was examined by comparing the colony number of NK cells before and after the culture.</p><p><b>RESULTS</b>After the initial 4-week expansion culture, we showed that (25.75 +/- 5.68)% of freshly sorted Lin-/34+/DRdim cells were able to generate functional NK-IC in one or more secondary FPIL6/IL2 cultures, whereas (6.81 +/- 1.97)% in the control. A total of 102 NK-IC cells were present when were cultured for 6-7 weeks in FPIL6/IL2 expansion medium, which was much higher than the 33 NK-IC cells in the control.</p><p><b>CONCLUSION</b>ML-IC assay will prove useful to assess a very primitive hematopoietic cell with multilineage generative capacity. FPIL6/IL2 is capable of initiating and promoting NK-IC expansion greatly in ex vivo cultures in terms of net-conservation and net proliferation.</p>