Halophile And Halotolerant Bacteria As A New Source For Anti-Cancer Stem Cell Metabolites

Because of their short life span, microorganisms known as easy producers of natural products.Halophile and halo tolerant microorganisms are extremophiles with ability to live in high saltconcentrations. There is some assumption that living in salt concentrations resemble to humanblood plasma makes them a good source of novel bioactive compounds or secondary metabolite withfewer side effects. A total of 36 microbial metabolites from saline environment of Iran have beenevaluated for their anticancer potential against six human cancer cell lines of breast, lung andprostate cancers and a fibroblast cell line as control. Downstream analysis of two most potentmetabolites was done using various assays to test the effect of these metabolites on cancer stemcells including sphere formation assay, colony formation assay, scratch assay, invasion andmigration assay.Among these 36 strains, seven metabolites were found to be cytotoxic against oneor more cancer cell lines after 48 h with cell line specific activities. The metabolite from two strainshas the potent cytotoxic effect on breast cell lines with IC50 of 100 μg/ml and lowered the size andnumber of sphere and colonies of this cell line. Scratch assay exhibited that this metabolite affectsthe migration ability of cell lines negatively and invasion and migration assay confirms scratchresults.Altogether, the study offers novel findings regarding the anti-cancer and anti-cancer stemcell potential of several halophilic bacterial species inhabiting the saline environment of Iran,which constitute valuable candidates for further isolation and characterization of bioactivemolecules.