Fig. 5

AUY922 delays tumor growth in conjunction with CCRT. a FaDu cells were implanted subcutaneously in BALB/c nude mice. After reaching 5-7 mm, tumors were treated with 2 Gy radiation. Tumors harvested at the times post radiation as indicated and probed for DNA damage signaling by western blot. b FaDu cells implanted as in A before treatment with cisplatin 5 mg/kg or three doses of AUY922 40 mg/kg on alternate days. Tumors treated with AUY922 were collected 16 h post final injection, cisplatin 24 h post injection. Western blot analysis performed for DNA damage signaling in response to cisplatin or reduction in HSP90 client proteins by AUY922. c Densitometry of changes due to HSP90 inhibition and response to cisplatin as shown in panel b, expressed as arbitrary scanning units adjusted for changes in GAPDH levels. d FaDu cells implanted as in A. Tumors were distributed into the following treatment groups with matching average tumor volumes; control; Cisplatin 5 mg/kg; AUY922 40 mg/kg × 3; cisplatin 5 mg/kg plus AUY922 40 mg/kg × 3; cisplatin 5 mg/kg plus three fractions of 2Gy; cisplatin 5 mg/kg plus three fractions of 2 Gy plus AUY922 40 mg/kg × 3. Exact scheduling as outlined in methods. Tumor volume expressed as percentage increase over basal volume at start of treatment. e, f FFPE blocks were sectioned and stained for RAD51 and 53BP1 foci. Automated quantification shown represents a minimum of 36 randomly distributed fields of view for RAD51 across 2 tumor blocks, 16-24 fields of view across for 53BP1 foci. Values ± SEM, statistical analysis by 2-tailed t-test; *p < 0.05, **p < 0.01, ***p < 0.001