CCI-779 is a potent inhibitor of mTOR with IC50 values of 0.6, 0.7, 0.7 and 50 nM for BT-474, MDA-MB-468, SKBR-3 and MCF-7 cells, respectively [1].
CCI-779 is an ester derivative of rapamycin and has improved pharmaceutical properties. As a mTOR inhibitor, CCI-779 affected cell proliferation in cancer cells in which the cell cycle targets are dysregulated by mTOR. When treated with a panel of 8 human breast cancer cell lines, CCI-779 showed potent antigrowth activity with IC50 values of 0.6, 0.7 and 0.7nM for BT-474, MDA-MB-468 and SKBR-3 cells, respectively. In mice bearing MDA-468 or MDA-435 xenografts, administration of CCI-779 significantly induced the regression of MDA-468 tumors but showed no effect on MDA-435 tumors, suggesting that CCI-779 was effect in PTEN mutant cells but not PTEN wild-type cells. CCI-779 also inhibited the growth of MCF-7 cells with IC50 value of 50 nM. Besides that, CCI-779 was also found to significantly inhibit cell growth in mice bearing myeloma tumors [1, 2].
References:
[1] Yu K, Toral-Barza L, Discafani C, et al. mTOR, a novel target in breast cancer: the effect of CCI-779, an mTOR inhibitor, in preclinical models of breast cancer. Endocrine-related cancer, 2001, 8(3): 249-258.
[2] Frost P, Moatamed F, Hoang B, et al. In vivo antitumor effects of the mTOR inhibitor CCI-779 against human multiple myeloma cells in a xenograft model. Blood, 2004, 104(13): 4181-4187.