I have 15 DE miRNAs between groups A and B. Is there a way to combine let's say DE of 5 miRNAs of interest to calculate the molecular signature ? The idea is to see if combined value of 5 miRNAs can differentiate Groups A and B ?

Zeng X, et al. (2012) Circulating miR-17, miR-20a, miR-29c, and miR-223 combined as non-invasive biomarkers in nasopharyngeal carcinoma. PLoS One 7(10):e46367.

The reference above is from qrt-pcr data but how to perform similar analysis in edgeR package ?