Table 2.

Summary of subtype associated genomic instability phenotypes

Intrinsic molecular subtype	In vitro cell line genomic instability patterns
LumB	•Defective decatenation G2 checkpoint•Functional DNA damage G2 checkpoint•Attenuated p-Ser15 p53 activation in response to catalytic topo II inhibitor•Low PDL•Delayed progression of S or G2 phase•Aneuploidy•Functional SAC
BL	•High MI, but low MER•Aberrant regulation of S/G2/M progression•Aneuploidy•Increased percentages of cohesion defects•Defective SAC
CL	•Low MER•Delayed progression of S and/or G2 phase•Aneuploidy•Increased percentages of cohesion defects•Functional SAC
Her2E	•Attenuated p-Ser15 p53 activation in response to catalytic topo II inhibitor•Low proliferation levels (S, MER, PDL)•Aberrant regulation of S/G2/M progression•Aneuploidy

Note: A summary of growth characteristics, G₂/M checkpoint function, and genomic instability patterns associated with each intrinsic subtype of breast cancer cell lines