SK 302, an antitumor substance, was purified from culture filtrate of Streptomyces sp. 302, an antitumor substance, was purified from culture filtrate of Streptomyces sp. 302 isolated in soils and we investigated in uitro antitumor activity
against
mouse tumor cell lines in previous report.
Now we studied in uitro and in vivo antitumor activity of SK 302 using mouse and human tumor cell lines.
This compound inhibited cellular proliferation of mouse tumor cell line(B16) and human tumor cell lines (SK-MEL-2, A549 and HCT-15) with half-maximal inhibitory concentration (IC) of 0.00738-0.0029mcg/ml, and IC values of adriamycin against four
tumor
cell lines was 0.17-0.21mcg/ml. SK 302 was 70-fold cytotoxic more than adriamycin against tested tumor cell lines. Colony forming efficiency of tumor cell lines in 0.3% soft agar was HCT-15>B16>SK-MLE-2>A549, and at the concentration
0.00125mcg/ml
of SK
302, colony formation of B16, SK-MEL-2 and A549 cell lines were completely inhibited, but HCT-15 cell line was more resistant to the compound.
In vivo antitumor activity of SK 302 using BDF1 mice model were investigated. At treatment with 0.6mcg of SK 302, persentage of increased life span(%ILS) was 00.8%, 114.8% and 150.5% for mouse group inoculated with B16, L1210 and P388 cell lines
respectively. In the case of adriamycin, ILS of the mouse group inoculated with B16, L1210 or P388 cells were 128.2%, 188.9% and 183%.
ILS of the mouse group inoculated with L1210 cells was 112.5% and 266%, respectively when treated with SK 302 every other day and every day for 9 days.
In conclusion, in vitro activity of SK 302 was more active than adriamycin against tested tumor cell lines. Invivo antitumor activity of SK 302 was schdule dependent rather than dose dependent.
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