(Philadelphia) The more scientists learn about microRNAs short strands of RNA that can interfere with normal gene activity the more obvious it becomes how closely they are associated with cancer. In a new study, scientists at The Wistar Institute and their colleagues have identified two microRNAs (miRNAs) that promote tumors deadly spread, or metastasis. One of the miRNAs may provide an early warning of metastatic breast cancer and the need for aggressive treatment.
By blocking the translation of tumor suppressor genes, miRNAs have been shown to facilitate the development of many types of cancer. In a study that will be published February 1 in Nature Cell Biology and is available online, the researchers describe how two miRNAs transformed non-invasive human breast cancer cells into cells that rapidly metastasized 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, says Qihong Huang, M.D., Ph.D., an assistant professor in Wistars Molecular and Cellular Oncogenesis Program and lead author and co-corresponding author on the study.
In 2006, miR-373 was identified as a possible oncogene a modified gene that causes cancer in testicular cancer. According to Huang, miR-520c is a new miRNA whose function has not been known until now.
Our most surprising finding is that miR-373 and isoforms of miR-520 are part of the same family, Huang says. 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.
Another intriguing characteristic of these two miRNAs is that they are not found in normal adult cells only in tumor cells. They are not in normal testis, but are expressed in testicular cancer,
|Contact: Abbey J. Porter|
The Wistar Institute