Dactolisib  (Synonyms: BEZ235; NVP-BEZ235)

HCT116 (PIK3CA mutant; kinase domain at H1047R), DLD-1 (PIK3CA mutant; helical domain at E545K), and SW480 (PIK3CA wild-type) human CRC cell lines (ATCC) and isogenic DLD-1 PIK3CA mutant and wild-type cells are maintained in DMEM. Cells are plated at different initial densities (HCT116: 3,000 cells/well, DLD-1: 5,500 cells/well, SW480: 4,500 cells/well, DLD-1 PIK3CA mutant: 7,000 cells/well, and DLD-1 PIK3CA wild-type: 9,000 cells/well) to account for differential growth kinetics. After 16 hours, cells are incubated with increasing concentrations of BEZ235 (10, 100, 1000 nM), and drug-containing growth medium is changed every 24 hours. Cell viability is assessed 16 hours after the initial plating and 48 hours after initiation of drug treatment using the colorimetric MTS assay CellTiter 96 AQueous One Solution Cell Proliferation Assay. Cell viability after drug treatment is normalized to that of untreated cells also grown for 48 hours. IC₅₀ values are calculated using 4 parameter nonlinear regression in GraphPad Prism 5^[2].

MCE has not independently confirmed the accuracy of these methods. They are for reference only.

Mice^[2]
Tumor-bearing Apc CKO mice are randomly assigned to treatment with either control vehicle alone (n=8) or 45 mg/kg body weight BEZ235 in 10% 1-methyl-2-pyrrolidone/90% PEG 300 (n=8) by daily oral gavage for 28 days. The treatment dose is chosen based on literature indicating that 40-50 mg/kg body weight BEZ235 effectively treats murine tumor models without adverse effects. Base on pharmacokinetic studies demonstrating maximal tissue concentration one hour after NVP-BEZ235 administration, tumor-bearing mice are sacrificed one hour after final treatment dose. Colonic tumor volume is assessed using calipers (width×length×height) and tumors are harvested for both western blot analysis and immunohistochemistry.
Rats^[3]
MENX-affected rats used. Three doses of BEZ235 are tested in MENX rats: 20, 30, and 45 mg/kg. As the two higher doses causes a weight loss >10% after 10 days of treatment, the dose of 20 mg/kg is used for further studies. For MRI studies, MENX-affected rats at 7 to 8 months of age (with sizeable adenomas but still in good general health) are treated for 14 days with BEZ235 (20 mg/kg) or placebo (PEG) administered daily per oral gavage.

MCE has not independently confirmed the accuracy of these methods. They are for reference only.

• [1]. Maira SM, et al. Identification and characterization of NVP-BEZ235, a new orally available dual phosphatidylinositol 3-kinase/mammalian target of rapamycin inhibitor with potent in vivo antitumor activity. Mol Cancer Ther, 2008, 7(7), 1851-1863.  [Content Brief]

  [2]. Roper J, et al. The dual PI3K/mTOR inhibitor NVP-BEZ235 induces tumor regression in a genetically engineered mouse model of PIK3CA wild-type colorectal cancer. PLoS One, 2011, 6(9), e25132.  [Content Brief]

  [3]. Lee M, et al. Targeting PI3K/mTOR Signaling Displays Potent Antitumor Efficacy against Nonfunctioning Pituitary Adenomas. Clin Cancer Res. 2015 Jul 15;21(14):3204-15.  [Content Brief]