Malignant mesothelioma: the antiproliferative effect of cytokine combinations on three human mesothelioma cell lines.

Tumour necrosis factor (TNF) combined with gamma-interferon (IFN gamma) is known to have antiproliferative effects on many tumour cells, both in vitro and in vivo. We investigated whether human mesothelioma cells would respond in a similar way. Mesothelioma cell lines established from primary tumours did not respond significantly in vitro to either TNF or IFN gamma alone but were inhibited by combinations of TNF and IFN gamma at concentrations as low as 5 ng/ml. In contrast, a mesothelioma cell line established from a metastatic tumour was sensitive to IFN gamma both alone and in combination with TNF but not to TNF alone. We also looked at the responses of one primary tumour cell line and the metastatic tumour cell line to alpha-interferon (IFN alpha) both alone and in combination with TNF. Both cell lines were sensitive to IFN alpha but were more sensitive to the THF/IFN alpha combination. We conclude that these low dose combinations of cytokines are worth further investigation in the development of mesothelioma therapy.