[Antitumor effect of LAK cells on CDDP resistant head and neck carcinoma cell line]

Antitumor effects of lymphokine-activated killer (LAK) cells on cisplatin resistant oral carcinoma cell line were evaluated in vitro by 51Cr release assay and in vivo by nude mouse model. Oral carcinoma cell line (KB) and its subline KBrc resistant to cisplatin were used as target cells. We observed the antitumor effect of LAK cells on both KB and KBrc cells in terms of cytotoxicity of 51Cr release assay, and tumor growth inhibition of nude mouse assay. However, when we compared the antitumor effect between KB and KBrc cells, KBrc cells demonstrated a significant decrease in susceptibility to killing by LAK cells in the in vitro and in vivo model in comparison with the antitumor effect of LAK cells on KB cells. These results, which were not similar to the results of previous studies reported, suggest that alternations of characteristics of tumor cells such as acquired drug resistance result in the decrease in susceptibility of tumor cells against LAK cells.