Scientists at the Winstar Institute have confirmed that the two microRNAs - miR-373 and miR-520c – trigger the spread of tumors, or metastasis.

Of the two, miR-373 may also give prior indication of metastatic breast cancer that requires rigorous treatment. t has been shown that, if the translation of tumor suppressor genes is blocked, miRNAs will make possible the development of many types of cancer.

The study, led by Qihong Huang, M.D., Ph.D., an assistant professor in Wistar’s Molecular and Cellular Oncogenesis Program, has shown the mechanism through which the two miRNAs completely changed non-invasive human breast cancer cells into rapidly metastasising cells in cell cultures and laboratory mice.

“Of the 450 miRNAs we tested, we found two, miR-373 and miR-520c, that induced cell migration in MCF-7 cells – a line of human breast cancer cells that normally does not metastasize,” Nature quoted Huang, as saying.

The researchers identified miR-373 as a probable oncogene – gene causing cancer on modification -- in testicular cancer in 2006. Huang also said that miR-520c is a new miRNA whose function has not been known till date.

“Our most surprising finding is that miR-373 and isoforms of miR-520 are part of the same family. Their seed sequences, or first eight nucleotides, are all very similar. It suggests this family of miRNAs could target similar genes and have important biological and pathological functions in cancer development and metastasis,” said Huang.