Background: Because drug resistance is one of the most important problems in patients with chronic myeloid leukemia (CML), finding new anti-cancer drugs especially from natural sources is research priority. Therefore, in this study, anti-cancer effects of ethyl acetate soluble metabolite of Iranian native bacteria, Streptomyces calvus, were studied using human chronic myeloid leukemia K562 cells.
Materials and methods: In this experimental trail, ethyl acetate soluble metabolites were isolated fromS. calvus bacteria. K562 cell line was treated by various concentrations of this metabolite for 12-72h intervals. Anti-proliferative effects of ethyl acetate soluble metabolite were studied by trypan blue exclusion test. Wright-Giemsa staining and latex particle phagocytosis assay were used to study differentiated cells.
Results: Ethyl acetate soluble metabolite induced growth inhibition in K562 cells in concentration and time- dependent manner. At the concentration of 200 ng/ml, the growth was inhibited 19-50% after 12-72h. Latex particle phagocytosis assay and Wright- Giemsa staining results revealed that K562 cells were differentiated toward monocytic- macrophagic lineage.
Conclusion: According to growth inhibitory and differentiating effects of S.calvus metabolite in K562 cells, this metabolite can be proposed for more investigations in differentiation therapy of CML patients.