A new study has discovered what might be an important factor in whether breast cancer will spread to other parts of the body: lincRNAs, incredibly long strands of RNA that affect the expression of genes. Mice who were injected with one of these strands, known as HOTAIR, developed ten times the number of tumors as mice in the control group, indicating that the RNA may be impeding the action of genes meant to control tumor growth.
LincRNAs have been known for nine years now. Another type of RNA, microRNAs, was already found to have an effect on the spread of cancer, but it was only recently that Stanford biologist Howard Chang began to investigate the role of other strands. His team found that levels of HOTAIR, the strand later used in the mouse experiment, were incredibly high in samples of metastic breast cancer, as well as some primary tumors. In addition, metastic cancers were much more common in women with increased HOTAIR in their primary tumors. The strand appears to inhibit genes that control the movement of cells, making it much easier for cancerous cells to invade the rest of the system and form new tumors.
The research suggests that it may be possible not only to predict metastic cancer through the use of HOTAIR tests, but also to reduce or even prevent its occurrence by blocking the strands or the enzymes they interact with.
Response to the study has been generally positive. According to George Calin, from the MD Anderson Cancer Center, the discovery has essentially opened up a new field of research. However, one Amsterdam geneticist, while accepting the study’s importance, notes that there are still many questions to be answered, such as why HOTAIR seems to have so much influence when there are many other types of lincRNA present in metastic tumors.