Fig. 6: Dual EGFR and PI3K inhibition is most effective at reducing tumor volume in vivo.
A BT20 cells were injected subcutaneously into the mammary fat pad of nude mice. 56 days post implantation, when the average size was 100 mm3, mice were randomized (R) to 15 mice into four groups and treated starting on day 63 post implantation (Tx) with control (0.5% carboxymethylcellulose) (black), 20 mg/kg afatinib (red), 20 mg/kg alpelisib (green), or the combination of both afatinib and alpelisib (blue) Monday through Friday for 36 days. Zoomed inset shows day 63–100. Statistical analysis was performed by Student’s t test, and * indicates p < 0.05 when comparing afatinib and alpelisib to control on day 94 and day 98. B After four days of treatment, four mice from each group were euthanized and the protein from the tumors was collected and immunoblotted for pEGFR (Y1068), EGFR, pS6 (S235/236), S6, and HSC70 (loading control). Data represents the average of four mice from each group ±SEM and statistical analysis was performed by Student’s t test, where ns indicates not statistically significant, * indicates p < 0.05 and ** indicates p < 0.01. C Bar graph of data from (A) on day 98 (36 days of drug treatment). Statistical analysis was performed by Student’s t test, where * indicates p < 0.05 when compared to control. No other comparisons were statistically significant.
