Figure 4. T47D breast cancer-derived cells are selectively sensitive to FBXW7 knockdown.
(A) FBXW7 and MYC expression levels positively correlate in Luminal A-type breast cancers. RNAseq (IlluminaHiSeq) data from TCGA breast invasive carcinoma dataset (TCGA_BRCA_exp_HiSeqV2) were clustered using a “cluster of clusters” approach. Expression of MYC and FBXW7 in LUMINAL A subtypes were estimated in RSEM normalized count and Pearson correlation coefficient (rho) was calculated using STATA. (B) FBXW7 knockdown decreases the viability of T47D cells. Fluorescence-based competition assay data are plotted as ratios of MYC ON to MYC OFF at the given time points. All cells were continuously induced with 1μg/ml doxycycline at every passage during the assay. Error bars represent the SEM of 3 replicates (p=0.0076 between shCONTROL and shFBXW7-8; p=0.01 between shCONTROL and shFBXW7-10). (C) Knockdown of FBXW7 in T47D cells. FBXW7 expression was down-regulated in T47D cells using lentiviral transduction of shRNA. shRNA expression was induced by 1μg/ml doxycycline and FBXW7 mRNA levels were assessed by RT-PCR. Error bars represent the SEM of 3 replicates.