**Microtubule and Cdc42 are the Main Targets of Docetaxel's Suppression of Invasiveness of Head and Neck Cancer Cells**

Yasunao Kogashiwa1, Hiroyuki Sakurai2 and Naoyuki Kohno1 *1Department of Otorhinolaryngology, Head and Neck Surgery, Kyorin University School of Medicine, 2Department of Pharmacology and Toxicology, Kyorin University School of Medicine, Japan* 

### **1. Introduction**

Many squamous cell carcinoma (SCC) of the head and neck presents with locally advanced disiease. In such cases, a combination chemotherapy of docetaxel, cisplatin, and 5FU, followed by radiation improved their survival (Posner et al. 2007; Vermorken et al. 2007). That is, addition of docetaxel to the combination of cisplatin and fluorouracil improves survival in head and neck squamous cell carcinoma. In a recent work to elucidate the possible mechanism, we investigated the effect of docetaxel on cell movement using head and neck cancer cell lines Hep2 and Ca9-22. Docetaxel treatment suppressed migration and invasiveness of head and neck cancer cells in vitro. We investigated the downstream effectors that control invasiveness after docetaxel administration in the present work.
