A new study has identified a potential microRNA biomarker for metastatic breast cancer. Although advancements in metastatic breast cancer treatments are continually being made, over 40,000 women were predicted to die from the disease in 2017. Better prognostic tools are needed to identify women with early stage cancer who are at a high risk for developing the advanced disease. The study findings were published in Oncotarget.
It is known that microRNAs, small non-coding RNA molecules ranging in length from 20-23 nucleotides, have a key role in breast cancer progression and can be an indicator of advanced disease. One of their main functions is to silence genes by binding to complementary sequences in the 3’UTR of mRNAs. Uncontrolled miRNA expression has been linked to metastases, carcinogenesis, and invasion.
In order to explore the prognostic role that a single miRNA could have, the research team collected plasma from 1,780 patients with stage I to III breast cancer at the time of diagnosis before they started treatment. Of that group, the team identified 115 patients who developed metastases and a matched group of 115 without disease progression. Using RNA sequencing, they measured the expression of 800 miRNAs at the time of diagnosis and identified that mir-24-3P was expressed a higher levels in patients that went on to develop metastatic disease. Using the Cancer Genome Atlas database (TCGA), they determined that this particular miRNA is overexpressed in primary breast cancer tissues and correlates with a poor survival rate.
"We found that mir-24-3p is highly expressed in metastatic breast cancer tissue compared to primary breast cancer tissue, and that those tumors show specific gene expression signature."
The study findings strongly suggest that mir-24-3p is involved in metastatic breast cancer and should be studied further as a potential novel biomarker for the advanced disease.