Figure 7.

Ionising radiation-induced ROS-mediated GI downregulation occurs through the involvement of ERα and ERK1/2 MAPK. Protein expression of phospho-ERα at Ser118 (p-S118ERα), ERα and phospho-p44/42 MAPK (Erk1/2) ( p-ERK1/2) by western blot detection or GI mRNA level in unirradiated cells or in cells at various time points post irradiation not treated or pretreated with (A) 10 mM NAC, (B) 10 μM Erk1/2 inhibitor U-0126 or (C) 100 nM ERα anti-oestrogen ICI 182,780. The pretreatment effect of NAC, U-0126 and ICI 182,780 has been shown only for cells after 48 and 72 h of IR treatment, where it yielded a major impact, being similar for the shorter time course points post irradiation. Whole-cell lysates were subjected to SDS–PAGE and probed with the appropriate Abs. Western blot analysis of β-actin expression is provided to show equal loading of the samples. Blots are representative of three different experiments done independently that gave the same results. Histograms indicate means±s.d. of three different cultures, and each one was tested in quadruplicate and expressed as percentage of unirradiated cells (control). ***P<0.001.