Figure 4. CD36 Is Essential for Survival of Lapatinib-Resistant Cells.
(A and B) Transient siRNA transfections were performed with Lipofectamine RNAiMAX (Life Technologies, Carlsbad, CA, USA) according to the manufacturer’s instructions.
(A) Knockdown of CD36 was confirmed by western blot 72 h after transfection.
(B) Apoptosis was measured by Annexin V staining via flow cytometry 72 h after transfection (mean ± SEM from 3 experiments).
(C) BT474 and rBT474 cells treated with the CD36 inhibitor sulfosuccinimidyl oleate (SSO) and lapatinib. Cell proliferation was measured by live-cell imaging using an Incucyte Zoom imager at 48 and 96 h of drug treatment. The results depict the average change in confluency from 3 replicate wells ± SD from 3 experiments.
(D) Treatment scheme for xenograft experiment presented in (E).
(E) BT474 and rBT474 xenografts were established in 6-week-old immunodeficient NSG mice. When tumors reached 300 mm3, mice were dosed with lapatinib (100 mg/kg) or vehicle twice a day by oral gavage and 10 μg JC63.1 or IgA control once every 3 days. Tumors were measured every 3 days, and mice were sacrificed after 33 days of treatment. Data are shown as average tumor volume ± SEM.
The significance of the bar graphs in (B) and (C) was assessed by unpaired Student’s t test, with the threshold of significance set at *p < 0.05. The significance of the growth curves in (E) was assessed using the “statmod” R package, with significance set at *p < 0.05 after Benjamini-Hochberg correction for multiple comparisons.