Therapeutic suppression of constitutive and inducible JAK\STAT activation in head and neck squamous cell carcinoma.

The oncogenic role of STAT3 has been elucidated in a number of human malignancies including leukemia, lymphoma, malignant glioma and cancers of the breast, lung, and head and neck (HNSCC). Here we show that WP1066 has profound anti-neoplastic effects in HNSCC, mediated in part by suppression of JAK2-STAT3 signaling. WP1066 inhibited constitutive and inducible STAT3 phosphorylation in both dose- and time-dependant manners. Further, the nuclear translocation of STAT3 was completely inhibited, resulting in decreased DNA binding activity. In vivo testing of WP1066 in a nude mouse orthotopic model of HNSCC demonstrated significant anti-tumor effects, with histological evidence of decreased cellular proliferation and angiogenesis. Collectively, these data suggest that WP1066 suppresses squamous cell carcinoma cell growth, in part through its effects on JAK-STAT pathways, and establishes this small molecule as potentially efficacious agent in the treatment of HNSCC.