Interferon-beta therapy for malignant melanoma: the dose is crucial for inhibition of proliferation and induction of apoptosis of melanoma cells.

We investigated the anti-tumor effect of human interferon-beta (HuIFN-beta) against malignant melanoma. In vitro study revealed that HuIFN-beta not only inhibited proliferation of melanoma cells (seven cell lines: MM-AN, MM-BP, MM-LH, MM-RU, PM-WK, RPM-EP, RPM-MC) but also induced apoptosis in a dose dependent fashion, though the sensitivity to HuIFN-beta was different among cell lines. In addition, we administered HuIFN-beta into cutaneous metastatic lesions of melanoma and evaluated clinical and histopathological effects. Although the size of the metastatic cutaneous lesion did not change by the intralesional injection of HuIFN-beta, histopathological examination revealed apoptotic changes of melanoma cells along with dense lymphohistiocytic infiltration. The present study confirmed direct and indirect inhibitory effects of HuIFN-beta on human melanoma cells and suggests that local higher concentration of HuIFN-beta is needed to eradicate melanoma lesions.