Figure 4: Nuclear Ca2+ buffering prevents ADAM-17 and EGFR overexpression levels induced by cumulative X-rays irradiation. A. Real-Time PCR demonstrated that XRCd10Gy increased mRNA expression of the metalloproteinase ADAM-17 (**p<0.01, using t test). Ca2+n buffering (Ca2+n) did not affect ADAM-17 expression levels, but prevented the increase of ADAM-17 mRNA expression induced by XRCd10Gy. B. EGFR mRNA expression increased compared to control, after XRCd10Gy (**p<0.01, using t test). Ca2+n buffering decreased EGFR mRNA expression levels induced by XRCd10Gy (***p<0.001, using t test). C-D. Western blotting to validate the expression patterns of ADAM-17 and its downstream effector, EGFR. E-F. Densitometric analyzes of ADAM-17 and EGFR proteins expression. Data show reduction in expression of both proteins under Ca2+n buffering condition, even upon XRCd10Gy, (*p<0.05, **p<0.01, analyzed using t test), in N = 3. G. Imunofluorescence images show that XRCd10Gyinduces translocation of EGFR from plasma membrane to the cell interior. H. Western blot of p-EGFR shows reduction of phosphorylated EGFR expression under Ca2+n buffering (*p<0.05,using t test).