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Objective: To establish the resistance the homoharringtonine alkali SKM-1 cell line, explore the biological characteristics of the cell lines and multi-drug resistance mechanisms. Established methods: by a larger dose intermittent the shock induction Act (pulsatile treatment) gradually increase the concentration of the drug-resistant homoharringtonine alkali SKM-1 cell line. Optical microscope resistant cell lines and general morphological changes in the parent cell line, doubling time and resistance index MTT assay, growth curve; using flow cytometry cell cycle distribution and intracellular daunorubicin content; conventional genetics method R-banding karyotype analysis; observed the differences between the two types of cells in nude mice; multidrug resistance gene (mdr-1 and MRP) and topo-IIa expression was detected by RT-PCR. Results: After seven months of cultivation, resistant cell lines SKIM-1/HHT, and resistant cell biological observations. Morphologically similar to the resistant cells and parental cells grown in suspension, cell size heterogeneity, the volume is too large, high nuclear cytoplasm ratio, see vacuoles in the cytoplasm and nucleus; resistant and parental cell immune phenotype approximation: SKM- 1 cells for CD2-CD2-, CD3-, CD4, CD5, CD7, CD8-, CD11b (42.28%), CD13 (65.35%), CD14-, CD33 (99.45%), SKM-1/HHT to , CD3-, CD4-, CD5-, CD7-, CD8-, CD11b (46.81%), CD13 (83.37%), CD14-, CD33 (99.61%): R-banding karyotype analysis showed that the resistant cells and parental cells broadly consistent with, but there are some differences; cell cycle distribution of detected drug-resistant cells in G1 phase cells increased, the decrease in S and G2 phase cells; nude mice in two cells into tumor was 0%; resistant cell lines with the parental cells resistant spectrum The analyzed, KM-1/HHT resistant to HHT 17.94 times, vincristine (Vincristine, VCR) the daunorubicin (Danuorubicin DNR), etoposide (Etoposide, VP-16) resistance index, respectively resistant cell lines was 8.78 times, 5.99 times and 13.76 times; DNR fluorescence was significantly lower than the parental cells the flow cytometry resistant cells; semi-quantitative real-time PCR shows: mdr-1 expression was significantly higher (20.1 times) MRP mildly elevated (3.56-fold), topo-II expression decreased (1:0.619). Conclusion: MDS turn HHT resistant leukemia cell lines SKM-1/HHT mdr-1 overexpression caused cell efflux resistance mechanisms involve enhanced the MRP and topo-Ⅱ a change may be partly involved in this process.
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