Bacteria-borne antidote for cancer
doi:10.1038/nindia.2010.105 Published online 2 August 2010
Researchers have isolated a new organic compound that halts the migration of cancer cells. They found the compound in a species of Streptomyces, a type of bacteria known to yield antibiotics.
The compound inhibited the migration of cultured human and mouse cancer cells by blocking the activity of cysteine protease, an enzyme whose level increases in cancer cells. This suggests that the compound could be a potential drug for treating cancer.
To hunt down effective inhibitors of this enzyme, the researchers screened several Streptomyces species by exposing them to high-protein-growth media.
They found one strain of Streptomyces species — NCIM 2081 — with protease inhibitory effect. They isolated the active compound CPI-2081 — a mixture of two novel pentapeptides — from the bacteria. The compound's inhibitory effect against migration of cancer cells was tested using human breast and skin cancer cells and mouse skin cancer cells.
The compound successfully inhibited migration of human breast and mouse skin cancer cells at concentrations lower than the cytotoxic dose.
The study is significant since the compound could be developed as a complementary therapy to existing anticancer drugs, which have harmful side effects due to non-specific action on non-cancerous host tissues. The researchers say spread of a tumour (metastasis) can be restricted by applying CPI-2081, followed by antitumour drugs.
The authors of this study are from: National Chemical Laboratory & National Centre for Cell Science, Pune, India; Yale University School of Medicine, New Haven, Connecticut, USA; Memorial Sloan Kettering Cancer Center (MSKCC), New York, USA and CEA Grenoble, LEMOH/INAC/SPrAM, Grenoble, France.