Figure 3

Acquired TMZ resistance is associated with chromosomal copy number increase. (a) Bottom 4 panels: metaphase spreads from TMZres cells showing overall chromosomal copy number gain compared to parental cells, and multiple copies of chromosomes 17 (8MGBA-TMZres, red signal, arrows) and X (42MGBA-TMZres, green signal, arrows). Metaphase spreads from the parental cells show 2 copies of the respective chromosomes. Top 4 panels: interphase nuclei from TMZres cells showing multiple copies of chromosomes 17 (8MGBA-TMZres, red signal) and X (42MGBA-TMZres cells, green signal) and two copies in the respective parental cells. (b) Quantification of chromosomes from a, bottom 4 panels 42MGBA-WT vs –TMZres p = <0.0001. (c) Quantification of probe signal from a, top 4 panels. Chi-squared test 8MBGA p = 0.03; 42MBGA p = <0.0001.