Heterogeneity of epithelial and stromal cells of head and neck squamous cell carcinomas in ex vivo chemoresponse.

ABSTRACT

BACKGROUND: Valid prediction of the effectiveness of chemotherapeutic agents in individual head and neck squamous cell carcinoma (HNSCC) is desirable and might be achieved using ex vivo assays. METHODS: Three biopsies from each of 15 HNSCC were taken, minced and digested by collagenase. The digested HNSCC was added to serial dilutions of either cisplatin (CIS) or docetaxel (DTX), which were prepared under flavin-protecting conditions in ECM-coated microtiterplates. After 72-h incubation, cultures were methanol-fixed and Giemsa-stained. The cutoff concentration (COC; concentration completely suppressing colony formation) for epithelial cells (EC) and stromal cells (SC) was evaluated. RESULTS: 12/15 HNSCC (80%) were evaluable. Despite significant correlation of COC of CIS in respect of colony formation of EC or SC, no significant differences in response of individual HNSCC specimens were found in the t test for paired samples (p > 0.16). The same applied to DTX. However, EC and SC showed heterogeneity in chemoresponses leading to COC variability of more than one titration step in 44.1% (CIS) and 20% of HNSCC (DTX). No significant correlation between the COC of both cell populations was found in HNSCC specimens. CONCLUSIONS: The ex vivo chemoresponse of EC and SC of HNSCC must be analyzed separately.