Original Article


MOLECULAR BIOLOGICAL EVIDENCES FOR THE GENETIC STABILITY OF DOXORUBICIN RESISTANT CELL LINE S-180R IN VIVO

Guoqiang Zheng, Fusheng Han, Tingjun Zhang, Maocheng Zhan, Xiangling Chen, Guangwei Xu

Abstract

Objective: In order to assess the genetic stability of doxorubicin resistance sarcoma S-180R cell line in vivo.
Methods: The drug resistant genes and molecules were examined by flow cytometry, Southern blot, Northern blot and RT-PCR.
Results: The results showed that drugefflux in S-180R increased nearly 100-folds, as compared with its parent cells, the rate of half peak width resistant cell/peak high decreased from 0.56 to 0.23 measured by flow cytometry after two years. The mdrl gene amplified and overexpressed significantly in S-180R and the expression of topoisomerase II α gene decreased remarkably in S-180R. There was no significant different of the MRP expression between S-180R and S-180.
Conclusion: These results indicated that drug resistance of S-180R was maintained and also increased. The major mechanism of drug resistance is the amplification and overexpression of mdrl gene, the decreased expression of topoisomerase II α also contributed to it. So, S-180R is an ideal experimental model for the study of doxorubicin resistance and its reversion in vivo.