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) 1×1 cm in size were cut into 350-450μm 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 (TNFα) and growth factors (TGFβ). 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: Under TNFα, the small tumors (T1 / T2) show higher E-cadherin expression than larger tumors (T3 / T4). The vimentin expression under TNFα behaved in the opposite direction, at T1 / T2 the expression decreased in T3 / T4 increased. Furthermore, an increased E-cadherin expression in N0 and diminished E-cadherin expression in N1 / N2b patients could be detected depending on the N-stage of the patients. Vimentin, on the other hand, was reduced in the N0 group and expressed more frequently in the N1 / N2b group. TGFβ induction also led to increased expression of vimentin in the T3 / T4 tumors and 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.