Int J Biol Sci 2012; 8(4):442-450. doi:10.7150/ijbs.4155
Prognostic Values of Filamin-A Status for Topoisomerase II Poison Chemotherapy
1. The Cancer Center, the First Hospital of Jilin University, Changchun 130021, China.
Filamin-A, also called Actin Binding Protein-280, is not only an essential component of the cytoskeleton networks, but also serves as the scaffold in various signaling networks. It has been shown that filamin-A facilitates DNA repair and filamin-A proficient cells are more resistant to ionizing radiation, bleomycin, and cisplatin. In this study, we assessed the role of filamin-A in modulating cancer cell sensitivity to Topo II poisons, including etoposide and doxorubicin. Intriguingly, we found that cells with filamin-A expression are more sensitive to Topo II poisons than those with defective filamin-A, and filamin-A proficient xenograft melanomas have better response to etoposide treatment than the filamin-A deficient tumors. This is associated with more potent induction of DNA double strand breaks (DSBs) by Topo II poisons in filamin-A proficient cells than the deficient cells. Although the expression of filamin-A enables cells a slightly stronger capability to repair DSB, the net outcome is that filamin-A proficient cells bear more DSBs due to the significantly enhanced DSB induction by Topo II poisons in these cells. We further found that filamin-A proficient cells have increased drug influx and decreased drug efflux, suggesting that filamin-A modulates the intra-cellular drug kinetics of Topo II poisons to facilitate the generation of DSB after Topo II poison exposure. These data suggest a novel function of filamin-A in regulating the pharmacokinetics of Topo II poisons, and that the status of filamin-A may be used as a prognostic marker for Topo II poisons based cancer treatments.
Keywords: Filamin-A, ABP-280, topoisomerase II poisons, chemotherapy, sensitization.
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How to cite this article:
Yue J, Lan S, Yuan C, Shen Z. Prognostic Values of Filamin-A Status for Topoisomerase II Poison Chemotherapy. Int J Biol Sci 2012; 8(4):442-450. doi:10.7150/ijbs.4155. Available from http://www.ijbs.com/v08p0442.htm