Fig. 1
Treatment with FPPa-OmoMYC reduces cell viability, proliferation and induces apoptosis in TNBC cell lines. a Sequence and representative 3D structure of FPPa-OmoMYC interfering the interaction of MYC and MAX. Four amino acids substitutions that discriminate OmoMYC from MYC are shown in red. The FPPa sequence was selected from a Phylomer library promoting intracellular delivery as assessed by split-GFP complementation assay and protein production was as described [73]. The FPPa sequence is filed under the available patent numbers 2017902976 and 2017201163 b Murine and c Human cell line panel; cells were treated with increasing concentrations of FPPa-OmoMYC and OmoMYC for 24 h. T11, A1.8 and B.15 cell murine cell lines were kindly provided by C. Perou and L. Varticovski. NIH-3T3, HDEF, MCF-7, ZR-751, MDA-MB-231, MCF-10A, and MCF-12A were obtained from ATCC. SUM149, and SUM159 were purchased from Asterand Biosciences. All cell lines were tested for mycoplasma. Cells were seeded and treated for 24 h with increasing concentrations (0–15 µM) of FPPa-OmoMYC and OmoMYC. After treatments, cell viability was assessed using CellTiter-Glo® 2.0 (Promega). Luminescence signals were measured using the EnVision Multilabel Plate Reader (PerkinElmer Inc.; Waltham, MA, USA). IC50s were calculated and transformed 95% confidence intervals provided by GraphPad Prism 6 software analysis (GraphPad Software Inc., San Diego, CA, USA). IF assays showing cleaved caspase-3 (Cell Signalling Technology, #9661) (d) and proliferation (Ki-67, Cell Signaling Technology, #9449) (e) levels in T11 cells treated with FPPa-OmoMYC for 24 h at a concentration of 15 µM. Cells were seeded on coverslips. The following day, cells were treated with FPPa, OmoMYC, FPPa-OmoMYC, and vehicle (PBS) at a concentration of 15 µM for 24 h. Next, IF for Ki-67 (proliferation) and cleaved caspase-3 (apoptosis) was performed as previously described [32]. The IC50 values shown are mean ± SD from biological triplicate samples. All p-values were derived using two-tailed unpaired Student t-test where *, ** and *** represent p < 0.05, p < 0.005 and p < 0.0005, respectively relative to NIH-3T3 and HDEF
