First experience of chick chorioallantoic membrane (CAM) assay in the clinical work flow with oral squamous cell carcinoma patients

INTRODUCTION: The oral squamous cell carcinoma (OSCC) is a leading cause of death in human malignancies. The aim of this study is to integrate the CAM Assay as a reliable and good working in vivo model for the evaluation of OSCC tumor samples and its growth into the clinical work flow. MATERIAL AND METHODS: Fresh human Tumor samples (OSCCs) 1 x 1 cm in size were cut into 350-450 mu m thick slices by a Vibratome and put on the prepared CAM model. After growth of the tumor tissue on the CAM, we started with topical induction of proinflammatory cytokines (TNF alpha) and growth factors (TGF beta). After further growth of the tumor on the assay, we explanted the tumor tissue and first performed microscopic and then immunohistochemical examinations. E-cadherin and vimentin were used as Epithelial-to-mesenchymal transition (EMT) -makers and the histologic preparations were evaluated histomorphometrically. The results were correlated with clinical parameters of the patients. RESULTS: Small tumors (T1 / T2) show higher E-cadherin expression than larger tumors (T3 / T4) (p = 0.01). The additional stimulation with TNF alpha or TGF beta has no additional inductive effect. Even the stimulation with TNF alpha repectively TGF beta lead to a higher E-cadherin expression in smaller tumors (T1 / T2). The Vimentin expression is the opposite. Depended on the patients N-Stage a trend towards an increase in the E-cadherin expression in N1 / 2 and diminished E-cadherin expression in N0 patients could be seen. There is no change with TGF beta in NO and N1 / 2 patients. Vimentin was reduced in the N0 group and expressed more frequently in the N1 / N2b group. An induction with both TNF alpha and TGF beta resulted in an increased expression of Vimentin in the N1 / N2b stages. CONCLUSION: By integrating a CAM assay into the clinical workflow, tumors with preserved tumor architecture can be cultured and subjected to histological and molecular biology studies. Effects on biological behavior are recognizable and demonstrable in this model. The key markers E-cadherin and vimentin alone are not sufficient to represent the complexity of the EMT in this model. Further molecular biology and signaling pathway analyzes are necessary