Differential resistance of melanoma cells to treatment with recombinant IFN-alpha2b and leukocyte IFN.
BACKGROUND
Interferon-alpha (IFN-alpha) subtypes bind to the same receptor and are expected to have the same biological functions. Whether or not leukocyte IFN, containing six major IFN-alpha proteins had the same anti-tumor effect as one subtype, recombinant IFN-alpha2b, was investigated.


METHODS
Three melanoma lines were treated with both types of IFN, and the effect on proliferation and survival was estimated both after short-term and prolonged treatment.


RESULTS
All the melanoma cell lines were sensitive to the antiproliferative effects of both IFN species during short-term treatment. However, upon prolonged culture, the frequency of resistant colony formation was significantly higher in cultures treated with IFN-alpha2b compared to those treated with leukocyte IFN. There was a qualitative difference between the resistant colonies selected by the two IFN species with respect to morphology, growth rate and sensitivity to apoptosis.


CONCLUSIONS
The development of resistant clones occurred at a lower rate during long-term treatment with leukocyte IFN containing six major subtypes of IFN-alpha as compared to IFN-alpha2b.
Ruuth
Kristina
K
Department of Molecular Biology, Umeå University, 90187 Umea, Sweden.
Berglund
Asa
A
Munoz
Varinia
V
Lundgren
Erik
E
D000970:Antineoplastic Agents / Q000494:pharmacology*; D048708:Cell Growth Processes / Q000187:drug effects; D019008:Drug Resistance, Neoplasm; D006801:Humans; D000077190:Interferon alpha-2; D016898:Interferon-alpha / Q000494:pharmacology*; D008545:Melanoma / Q000188:drug therapy* / Q000473:pathology; D011994:Recombinant Proteins; D014407:Tumor Cells, Cultured
D000970:Antineoplastic Agents; D000077190:Interferon alpha-2; D016898:Interferon-alpha; D011994:Recombinant Proteins