In order to investigate the effect of chitosan/pshRNA plasmid nanoparticles targeting MDR1 genes on the resistance of A2780/TS cells to paclitaxel, chitosan/pshRNA plasmid nanoparti- cles were synthesized by means of ...In order to investigate the effect of chitosan/pshRNA plasmid nanoparticles targeting MDR1 genes on the resistance of A2780/TS cells to paclitaxel, chitosan/pshRNA plasmid nanoparti- cles were synthesized by means of a complex coacervation technique and transfected into A2780/TS cells. The cells transfected with MDRl-targeted chitosan/pshRNA plasmid nanoparticles were experimental cells and the cells transfected with chitosan/pGPU6/GFP/Neo no-load plasmid nanoparticles served as negative control cells. Morphological features of the nanoparticles were observed under transmission electron microscope （TEM）. MDR1 mRNA expression was assessed by RT-PCR. Half-inhibitory concentration （IC50） ofpaclitaxel for A2780/TS cells was determined by MTT method. TEM showed that the nanoparticles were round-shaped, smooth in surface and the diameters varied from 80 to 120 nm. The MDR1 mRNA in the transfected cells was significantly decreased by 17.6%, 27.8% and 52.6% on the post-transfection day 2, 4 and 7 when compared with that in A2780/TS cells control （P〈0.05）. MTT assay revealed that the relative reversal efficiency was increased over time and was 29.6%, 51.2% and 61.3% respectively in the transfected cells 2, 4, 7 days after transfection and IC_50 （0.197±0.003, 0.144±0.001, 0.120±0.004） were decreased with difference being significant when compared with that in A2780/TS （0.269±0.003） cells control （P〈0.05）. It was concluded that chitosan/pshRNA plasmid nanoparticles targeting MDR1 can effectively reverse the paclitaxel resistance in A2780/TS cells in a time-dependent manner.展开更多
To investigate the relationship between c-myc expression and mdr1 regulation in multidrug resistance (MDR) tumor cell line KBv200 Methods A DNA sequence encoding the ribozyme gene was incorporated into a eukary...To investigate the relationship between c-myc expression and mdr1 regulation in multidrug resistance (MDR) tumor cell line KBv200 Methods A DNA sequence encoding the ribozyme gene was incorporated into a eukaryotic expression vector (pHβ Apr-1 neo) and transfected into the cell line KB, which is resistant to vincristine and expresses the MDR phenotype The changes of c-myc protein, P-glycoprotein (P-gp) and c-myc mRNA in the KB cell line were assessed before and after treatment with anti-mdr1-ribozyme using immunohisto-chemistry, flow cytometry and semi-quantitative RT-PCR methods Results The results demonstrate elevated levels of c-myc mRNA and c-myc protein as well as P-gp in KBv200 cells which are resistant to vincristine (VCR), compared to these of the KB cell which is not resistant to VCR The expression of c-myc protein, P-gp and c-myc mRNA in the multidrug resistant cell, KBv200, displayed higher than that in the sensitive cell, KB However, after reversing the multidrug resistance phenotype by anti-mdr1-ribozyme, the level of c-myc protein, P-gp and c-myc mRNA expression showed significant down-regulation in KBv/5mR3, without difference in KB/5mR3 and KB Conclusion The results of our study suggest that there is a close relationship between c-myc gene and mdr1 gene c-myc may be involved in regulating the expression of mdr1展开更多
基金supported by grants from Scientific Research Foundation of Hubei health department (No.JX2B17)a grant from Key Technologies R&D Programme of Hubei Province (No.2007AA301C20)
文摘In order to investigate the effect of chitosan/pshRNA plasmid nanoparticles targeting MDR1 genes on the resistance of A2780/TS cells to paclitaxel, chitosan/pshRNA plasmid nanoparti- cles were synthesized by means of a complex coacervation technique and transfected into A2780/TS cells. The cells transfected with MDRl-targeted chitosan/pshRNA plasmid nanoparticles were experimental cells and the cells transfected with chitosan/pGPU6/GFP/Neo no-load plasmid nanoparticles served as negative control cells. Morphological features of the nanoparticles were observed under transmission electron microscope （TEM）. MDR1 mRNA expression was assessed by RT-PCR. Half-inhibitory concentration （IC50） ofpaclitaxel for A2780/TS cells was determined by MTT method. TEM showed that the nanoparticles were round-shaped, smooth in surface and the diameters varied from 80 to 120 nm. The MDR1 mRNA in the transfected cells was significantly decreased by 17.6%, 27.8% and 52.6% on the post-transfection day 2, 4 and 7 when compared with that in A2780/TS cells control （P〈0.05）. MTT assay revealed that the relative reversal efficiency was increased over time and was 29.6%, 51.2% and 61.3% respectively in the transfected cells 2, 4, 7 days after transfection and IC_50 （0.197±0.003, 0.144±0.001, 0.120±0.004） were decreased with difference being significant when compared with that in A2780/TS （0.269±0.003） cells control （P〈0.05）. It was concluded that chitosan/pshRNA plasmid nanoparticles targeting MDR1 can effectively reverse the paclitaxel resistance in A2780/TS cells in a time-dependent manner.
基金ThisworkwassupportedbythegrantsfromNationalNaturalScienceFoundationofChina (No 39870 813)
文摘To investigate the relationship between c-myc expression and mdr1 regulation in multidrug resistance (MDR) tumor cell line KBv200 Methods A DNA sequence encoding the ribozyme gene was incorporated into a eukaryotic expression vector (pHβ Apr-1 neo) and transfected into the cell line KB, which is resistant to vincristine and expresses the MDR phenotype The changes of c-myc protein, P-glycoprotein (P-gp) and c-myc mRNA in the KB cell line were assessed before and after treatment with anti-mdr1-ribozyme using immunohisto-chemistry, flow cytometry and semi-quantitative RT-PCR methods Results The results demonstrate elevated levels of c-myc mRNA and c-myc protein as well as P-gp in KBv200 cells which are resistant to vincristine (VCR), compared to these of the KB cell which is not resistant to VCR The expression of c-myc protein, P-gp and c-myc mRNA in the multidrug resistant cell, KBv200, displayed higher than that in the sensitive cell, KB However, after reversing the multidrug resistance phenotype by anti-mdr1-ribozyme, the level of c-myc protein, P-gp and c-myc mRNA expression showed significant down-regulation in KBv/5mR3, without difference in KB/5mR3 and KB Conclusion The results of our study suggest that there is a close relationship between c-myc gene and mdr1 gene c-myc may be involved in regulating the expression of mdr1
