Ba. Narayanan et Gg. Re, IGF-II down regulation associated cell cycle arrest in colon cancer cells exposed to phenolic antioxidant ellagic acid, ANTICANC R, 21(1A), 2001, pp. 359-364
Altered cell and tissue differentiation is characteristic of premalignant l
esions before they become invasive and metastatic. One approach to controll
ing preneoplastic lesions is to block their expansion with non-toxic agents
that suppress cells proliferation and induce apoptosis. Here, we show that
ellagic acid, a natural, dietary phenolic antioxidant when given at 10(-5)
M for 48 hours to colon cancer cells (SW 480), induced down regulation of
insulin like growth factor IGF-II, activated P21((waf1/Cip1)), mediated a c
umulative effect on G1/S transition phase and caused apoptotic cell death.
SW480 colon cancer cells expressed significant mRNA levels for the mitogeni
c insulin like growth factor (IGF-II). Collectively, these observations sug
gest that growth inhibition by ellagic acid is mediated by signaling pathwa
ys that mediate DNA damage, triggers p53, which in turn activates p21 and a
t the same time alters the growth factor expression, resulting in the down
regulation of IGF-II.