Local and systemic Curcumin C3 complex inhibits 4NQO-induced oral tumorigenesis modulating FGF-2/FGFR-2 activation.

Head and Neck Squamous cell carcinoma (HNSCC) can be characterized by synchronous tumors in the upper aerodigestive tract. Second primary tumors as a result of field cancerization are a significant problem amongst patients with risk factors for HNSCC, indicating a need for chemo preventive agents. We investigated the efficacy of local and systemic Curcumin C3 complex (C3); a purified mixture of Curcumin, bisdemethoxy Curcumin and demethoxy Curcumin as a chemo preventative agent in 4-nitroquinoline-1-oxide (4NQO)-induced tumorigenesis in mice. The effect of local C3 application was compared to C3 administered orally and in combination with systemic administration. C57Bl/6 mice were administered 4NQO (50 µg/ml) in the drinking water for 16 weeks. At 12 weeks, mice were subjected to daily treatment with either vehicle (control), or 15 mg C3 complex by local delivery, gavage, or combined local and gavage for 28 days (16 week time point), and followed up to 22 weeks. Compared to local and oral systemic C3 administration, combination of local and systemic application significantly decreased multiplicity of 4NQO-induced preneoplastic and neoplastic lesions (p<0.05). Treatment with C3 correlated with a decrease in cell proliferation compared to the 4NQO group. Further, pre-treatment with C3 complex significantly attenuated 4NQO induced expression of basic fibroblast growth factor (FGF-2) and its cognate receptor FGFR-2, suggesting an important role of FGF-2/FGFR-2 axis in chemoprevention of HNSCC (p<0.05). Our findings suggest that a combination of local and systemic C3 complex could effectively target proliferation and inhibit 4NQO-induced tumorigenesis modulation of the FGF-2/FGFR-2 axis as a mechanism for its efficacy.