MSC-AR bind to erbB2-expressing lung cells in vivo in transient transgenic model. (A) Transient expression of erbB2 in the lungs of hCAR mice was induced by iv injection of AdCMVerbB2. Expression of erbB2 exclusively in the lungs of hCAR mice were confirmed by Western Blot of organ lysates. Lane M is Marker, lane SK - erbB2 positive control (SKOV3ip cell lysate), lane Lu - lung lysate, next lanes, labeled Sp, He, Li, Ki and Ov represent spleen, heart, liver, kidney, and ovary lysates correspondingly. Small triangle points to the size of erbB2-specific signal. (B-E) Kinetics of MSC-GFP and MSC-AR distribution to the erbB2-lungs of hCAR mice. MSC-GFP and MSC-AR labeled with firefly luciferase were injected iv in erbB2-preconditioned hCAR mice at 1x106 cell/mouse. In the first experiment (B, D) mice were followed at early time points after injection (4, 8, 14, 24 hrs), in the second experiment (C, E) later time points (24, 32, 50, 70 hrs) were investigated. Luciferase expression was detected by imaging of whole animal (C) imaging of excised lungs (B) and by luciferase expression analysis of lung lysates (D,E). Data are presented as number of cells per mg of protein in lung lysates. *-P = 0.05, ** - P = 0.01.