Hitomi Toda

GROWTH OF THE MALIGNANT AND NONMALIGNANT HUMAN SQUAMOUS CELLS IN A PROTEIN-FREE DEFINED MEDIUM

SummaryA novel protein-free synthetic medium has been developed for the culture of human squamous cell carcinoma cells. This medium, designated PF86-1, supports the serial subcultivation of six out of nine human squamous cell carcinoma cell lines in a protein-free, chemically defined condition without the adapting culture from serum-containing conditions. These cell lines growing in PF86-1 exhibited nearly equal potency to grow in massive culture without noticeable changes in morphology but presented a significantly decreased level of colony forming efficiency when compared with the cells cultured in serum-containing media, suggesting the implication of some autocrine mechanism. Interestingly, this medium supported the growth of normal human squamous cells of oral mucosa and skin for more than 2 mo. in the primary explant culture in spite of high levels of calcium ion concentration, where the overgrowth of fibroblasts as contaminant was not observed. These results suggest that PF86-1 supports the growth of cells derived from epidermal tissues selectively and provides the same defined condition for growth of malignant and nonmalignant human squamous cells. It seems, therefore, that PF86-1 allows investigations on the products of squamous cell carcinoma cells or on the differences of growth mechanisms between normal and neoplastic human squamous cells.

The Effect of Recombinant CD80-Adenovirus and Interleukin-12 on Generation of Cytotoxic T Lymphocytes Against Autologous Tumour in Patients with Oral Squamous Cell Carcinoma

Abstract Objectives: The combined effect of a costimulatory molecule, CD80 and interleukin-12, on generation of cytotoxic T lymphocytes against autologous tumour cells was investigated using peripheral blood lymphocytes from patients with oral squamous cell carcinoma. Materials and Methods: The use of recombinant adenovirus enabled efficient transduction of CD80 into all primary cultured squamous cell carcinoma cells. Peripheral blood mononuclear lymphocytes from patients with oral squamous cell carcinoma were co-cultured with CD80-transduced autologous tumour cells in the presence of interleukin-12. Results: The levels of cytotoxicity against autologous tumour in patients with squamous cell carcinoma were individually variable. However, the cytotoxicity against autologous tumour cells, but not against allogeneic tumour cells, was efficiently inhibited by the addition of either anti-CD3, anti-CD8, or anti-MHC class I mAb, suggesting that the induced cytotoxicity was specific for autologous tumour cells. Conclusion: The results suggest that generation of tumour-specific cytotoxic T lymphocytes using a combination with CD80 costimulation and interleukin-12 is effective in oral squamous cell carcinoma patients. However, a further approach for expanding the number of specific effector cells will be required for clinical application.