temporal dissection of k-rasg12d mutant in vitro and in vivo using a regulatable k-rasg12d mouse allele时间解剖k-rasg12d突变体在体外和体内使用regulatable k-rasg12d鼠标等位基因.pdf

Temporal Dissection of K-rasG12D Mutant In Vitro and In Vivo Using a Regulatable K-rasG12D Mouse Allele 1 . 1 . 2 3 1 1 Zuoyun Wang * , Yan Feng * , Nabeel Bardessy , Kwok-Kin Wong *, Xin-Yuan Liu *, Hongbin Ji * 1 State Key Laboratory of Cell Biology, Institute of Biochemistry and Cell Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai, China, 2 Massachusetts General Hospital Cancer Center, Massachusetts General Hospital, Boston, Massachusetts, United States of America, 3 Department of Medical Oncology, Dana-Farber Cancer Institute, Harvard Medical School, Boston, Massachusetts, United States of America Abstract Animal models which allow the temporal regulation of gene activities are valuable for dissecting gene function in tumorigenesis. Here we have constructed a conditional inducible estrogen receptor-K-rasG12D (ER-K-rasG12D) knock-in mice allele that allows us to temporally switch on or off the activity of K-ras oncogenic mutant through tamoxifen administration. In vitro studies using mice embryonic fibroblast (MEF) showed that a dose of tamoxifen at 0.05 mM works optimally for activation of ER-K-rasG12D independent of the gender status. Furthermore, tamoxifen-inducible activation of K-rasG12D promotes cell proliferation, anchor-independent growth, transformation as well as invasion, potentially via activation of downstream MAPK pathway and cell cycle progression. Continuous activation of K-rasG12D in vivo by tamoxifen treatment is sufficient to drive the neoplastic transformation of normal lung epithelial cells in mice. Tamoxifen withdrawal after the tumor fo