Skip to main content
. Author manuscript; available in PMC: 2012 Aug 1.
Published in final edited form as: Cancer Prev Res (Phila). 2011 Apr 19;4(8):1275–1284. doi: 10.1158/1940-6207.CAPR-11-0095

Figure 1.

Figure 1

Sensitivity of human breast cells to SS correlates with PDE5 expression. A, inhibition of cGMP PDE activity by SS in lysates of MDA-MB-231 and ZR75-1 breast tumor cells or HMEC. B, effect of SS on intracellular cGMP levels in HMEC, MDA-MB-231, and ZR75-1 cells after 30 minutes of treatment. C, effect of SS on caspase 3 and 7 activity in HMEC, MDA-MB-231, and ZR75-1 cells after 6 hours of treatment. +, 1 μmol/L staurosporine. D, activity of cGMP PDE isozymes in HMEC, MDA-MB-231, and ZR75-1 lysates as measured by overall percent inhibition induced by the PDE2 selective inhibitor EHNA, the PDE3 selective inhibitor milrinone, or the PDE5 selective inhibitor sildenafil, or as measured by fold increase in cGMP hydrolysis after treatment with the activators of PDE1, calcium and calmodulin. E, expression of cGMP PDE isozymes in MDA-MB-231, SKBR3, and ZR75-1 breast tumor cells or HMEC as measured by Western blotting.