Breast cancer is a type of cancer that develops from breast tissue as a consequence of uncontrolled division of breast tissue cells. Breast cancer is not detrimental if it is discovered in its early stages before it metastasizes and spreads to other tissues and organs in the body. It is the most recurrent form of invasive cancer that affects females globally. It affects both sexes and accounts for 18.2% of deaths worldwide caused by all types of cancers. Early detection methods of breast cancer, specifically mammography and clinical examinations, are widely used but they have limitations and the rate of false-positives goes up to 31%.

A new method, known as microRNAs, seems to be the next best way to detect breast cancer before it develops. MicroRNAs play important roles in the regulation of many cellular functions and disease states, including cancer. The presence of microRNAs in serum and plasma makes them promising candidates for breast cancer detection. They are short non-coding RNAs, about 22 nucleotides long, implicated almost in every biological process. A group of researchers studied microRNAs that were secreted from breast cancer cell lines, plasma samples of humans and plasma of mouse PDX and analyzed the contents of their exosomes.


micrornaThe researchers found that some microRNAs were highly enriched in breast cancer exosomes. An important observation of the study was that the microRNA-1246 was highly abundant in exosomes of PDX mouse plasma which indicates that these miRNAs are released into body fluids and therefore can be used as biomarkers for breast cancer in plasma.

The researchers took this study a step further and analyzed the plasma exosomes of 16 patients diagnosed with breast cancer and compared those results with plasma exosomes obtained from healthy individuals. These observations showed that microRNA-1246 along with microRNA-21 were present at significantly elevated levels in patients with breast cancer.

These results provide a novel strategy for breast cancer detection at early stages by analyzing circulating microRNAs of plasma. Further studies that quantify these results and show that microRNAs are biomarkers for breast cancer are required.





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  • Bethany N. Hannafon, Yvonne D. Trigoso, Cameron L. Calloway,Y. Daniel Zhao, David H. Lum, Alana L. Welm, Zhizhuang J. Zhao, Kenneth E. Blick, William C. Dooley and W. Q. Ding. Plasma exosome microRNAs are indicative of breast cancer. Breast Cancer Res. 2016
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