Down-regulation of ICBP90 contributes to doxorubicin resistance

作者：Wang Jingxuan; Song Ying; Xu Shanqi; Zhang Qingyuan^*; Li Yulian; Tang Dabei; Jin Shi

来源：European Journal of Pharmacology, 2011, 656(1-3): 33-38.

DOI：10.1016/j.ejphar.2011.01.042

• ICBP90
• Doxorubicin
• Topo II alpha
• Breast cancer
• Cell cycle arrest

Acquired resistance to doxorubicin has become a serious obstacle in breast cancer treatment. The underlying mechanism responsible for this has not been completely elucidated. In this study, a doxorubicin-resistant MCF-7/Dox cell was developed to mimic the occurrence of acquired doxorubicin resistance. We next contrasted the expression profiles of ICBP90 and Topo II alpha and tumor cell growth of different breast cancer cell lines to doxorubicin. Decreased expression levels of ICBP90 and Topo II alpha were found in doxorubicin-resistant cells. To examine its function in chemoresistance, RNA interference (RNAi) and forskolin stimulation experiments further demonstrated that ICBP90 and Topo II alpha were involved in the proliferation of cells that had acquired doxorubicin resistance. In MCF-7/Dox and ICBP90-siRNA cells, the cell growth wasn't inhibited by doxorubicin and preferentially arrested in G1 phase. However, after forskolin increased the Topo II alpha expression, these breast cancer cells were again found to be inhibited by doxorubicin. Further, immunohistochemical assay breast cancer patients accepted EFC regimen showed ICBP90 was significantly associated with tumor cell proliferation, locally advanced disease and Topo II alpha expression. In conclusion, down-regulation of ICBP90 induced the descended expression of Topo II alpha protein which is the target enzyme of doxorubicin.

• 出版日期2011-4-10
• 单位哈尔滨医科大学