Busting the Breast Cancer with AstraZeneca’s Gefitinib
Table 1
The various functions of the EGFR receptors during various stages of mammary gland growth and consequences of the mutated receptor.
EGFR receptors
Expression
Mice with mutated receptor
EGFR1
Expressed in entire phases of mammary gland development (mice with EGFR 1 mutation)
Scant development of mammary tissue along with defective ductal growth [79, 80]
EGFR2
Expressed in entire phases of mammary gland development (transgenic dominant-negative DN EGFR2 mice)
Ductal growth was normal, but lobuloalveoli were defective [81]
EGFR3
Essential during pubescent mammary gland development [77], enhanced lactogenic expansion and differentiation of mammary gland during pregnancy, by activation of Akt and STAT5A (transgenic mice expressing WAP-driven Cre recombinase) [82]
Ductal outgrowth penetration phenotype was defective, lobuloalveolar development was not affected (EGFR3-null glands in mice) [77]
EGFR4
Elevated levels especially in pregnancy and lactation (transgenic dominant-negative DN EGFR4 mice)
