ABSTRACT
OBJECTIVE: To set up an easy and effective method for biotinylation of small molecule drugs with long chain. METHODS: Biotinylated 6-aminocaproic acid was synthesized as intermediate by one step method, doxorubicin(DOX) with auto-fluorescence was used as the first drug, and by DCC and DMAP catalysis, biotinylated DOX was synthesized. Using the double fluorescence system of DOX, the binding ability of biotinylated DOX to avidin and its biological activity were determined. When verified to be reasonable and effective, the method was applied to catalyze biotinylated paclitexal (PTX) which didn′t have auto-fluorescence itself, and the physical and chemical characteristics, and biological activities as well as the visualization were tested. RESULTS: The binding rate of synthesized DOX to avidin was 93.7%; the cells inhibition rate and localization were the same as DOX; the purity of biotinylated PTX was 84.42%, and the structure shown by NMR was correct; the cell inhibition rate was the same as PTX; the combination of PTX with microtubules was observed by visual modification. CONCLUSION: The method supplies a temperate way for biotinylation, and can be used for the synthesis and visualization of small molecules as probes and research of drug mechanism.
ABSTRACT
Aim To study the relationship between apolipoprotein A-Ⅱ (APOA-Ⅱ) and adriamycin re-sistance. Methods The drug sensitivity of cells was analyzed by IC50assay. The localizations of ADM in MCF7/W,MCF7/ADM and APOA-Ⅱ transgenic cells were observed by laser scanning confocal microscopy. RT-PCR and Western blot were applied to detect the gene and protein expression in MCF7/W and MCF7/ADM cells, respectively. The APOA-Ⅱ transgenic HEK293 cells were analyzed by IC50assay,the IC50of breat cancer cells T470 and MDA-MB231 were ana-lysed as well. Results Compared with MCF7/W cells,the resistance index of MCF7/ADM cells got 13. 0 (P<0.05). ADM localized mainly in the nuclei of MCF7/W cells,but none in the nuclei of MCF7/ADM cells. Meanwhile,the localization of ADM in APOA-Ⅱtransgenic MCF7/W cells was obviously less than that in normal parent MCF7/W cells. The gene and protein expression levels of APOA-Ⅱ in MCF7/ADM cells were both higher than in MCF7/W cells (P<0.05);the sensitivity of APOA-Ⅱtransgenic HEK293 to ADM was also reduced (P<0.05). Furthermore,the sensi-tivity of breast cancer cells T47D and MDA-MB231 to ADM was reduced as well (P<0.05). Conclusion APOA-Ⅱ is found to be positively related to ADM re-sistance,which would provide instruction for the clini-cal usage of ADM.