Table 1.

Status of key pathways and gene products of cell lines used in this study

MechanismMCF-10AMCF-7MDA-mb-231References
ApoptosisProficient. Normal Bcl-2, p53, and p21 expression and regulation.Proficient via caspase-6, no caspase-3 expression, ↑ Bcl-2 expression, and normal p53 and p21 expression and regulation.Proficient but resistant, ↑ Bcl-xL expression, a p53 mutation with ↑ expression, and lower than normal p21 expression with subdued induction.37, 38, 44, 45, 49, 51, 57, 58, 6567
Cell cycle checkpointG1, S, and mitotic spindle checkpoint proficient. Normal p53 and p21 expression and regulation.Transient G1 and mitotic spindle checkpoints. S and G2 checkpoint proficient. Normal p53 and p21 expression and regulation.G1, S, G2, and mitotic spindle checkpoint proficient. p53 mutation with ↑ expression and lower than normal p21 expression with subdued induction.3338, 49, 50, 56, 67, 68
Genome stabilityLow/normal chromosomal instability.High chromosomal instability. High single-nucleotide instability (mismatch repair defect). High single-strand break repair defect.Moderate chromosomal instability. Slight increase in single-nucleotide instability. Moderate single-strand break repair defect.36, 48, 49
Contact inhibitionNormal down-regulation of mitogen-activated protein kinase. Normal anchorage-dependent growth.Cell density does not decrease mitogen-activated protein kinase activity.Cell density does not decrease mitogen-activated protein kinase activity.39
ProliferationEstrogen receptor positive. Normal anchorage-dependent growth. EGF-dependent growth. Normal Her-2/Neu/c-ErbB-2 expression. Normal Ras expression. Normal phosphorylation of Rb.↑ Estrogen receptor expression, estrogen-dependent growth. EGF-independent growth. ↑ Her-2/Neu/c-ErbB-2 expression. Amplified N-ras. Rapid phosphorylation of Rb.Estrogen receptor negative, estrogen independent/unresponsive. EGF-independent growth but responsive for migration. Normal/low Her-2/Neu/c-ErbB-2 expression. Activated Ki-ras mutation. Deregulated dephosphorylation of Rb.31, 4043, 52, 53, 59