Figure 6.

(a) Macroscopic images of cells cultivated after explantation of LSL-MYCN;Dbh-iCre tumors. Scale bars=100 μm. (b) Representative genotyping PCR validating the MYCN knock-in allele (left) and the Dbh-iCre transgene (right) in cells cultured from murine neuroblastoma. Heart (he) from wild-type (wt) and heart (he) and tumor (tu) from heterozygous LSL-MYCN;Dbh-iCre mice (+/-) as controls. (c) PCR validating the removal of the transcriptional termination site 5′ of the MYCN allele in cells cultivated after explantation of LSL-MYCN;Dbh-iCre tumors. Wild-type (wt), heterozygous LSL-MYCN;Dbh-iCre (+/−), heart (he), tumor (tu). (d) Bioluminescence imaging of mNB-A1 cells. Luciferase activity: low=blue; high=red. luciferin (luc). (e) MYCN expression (qPCR) in mNB-A1 cells compared with various control tissues and to a representative LSL-MYCN;Dbh-iCre tumor. Expression was normalized to that in normal adrenal glands. Student's t-test: ***=P<0.001; NS=not significant. (f) Western blot analysis confirms MYCN expression in mNB-A1 cells compared with heart and LSL-MYCN;Dbh-iCre tumor. (g) Tumor growth after engraftment of 10⁷ mNB-A1 cells into three nude mice at day 0. (h) Bioluminescence imaging of mNB-A1 cells growing in nude mice. Luciferase activity: low=blue, high=red.