BioCentury
ARTICLE | Distillery Techniques

Techniques: mRNA levels in tumor exosomes as markers of response to cancer treatment

May 21, 2015 7:00 AM UTC

A microfluidics chip-based method for detecting mRNA in tumor exosomes could help monitor response to cancer therapies. The immuno-magnetic exosome RNA (iMER) platform measures exosomal levels of mRNA via on-chip enrichment of exosomes in serum, isolation of exosomal mRNA, and real-time mRNA quantification. In multiple human glioblastoma multiforme (GBM) cell cultures, iMER showed that levels of exosomal O6-alkylguanine alkyltransferase (MGMT) mRNA and N-methylpurine-DNA glycosylase (MPG; APNG; AAG) mRNA - two genes involved in repair of drug-induced DNA damage - correlated with mRNA levels in the cells and with the cells' resistance to the generic DNA alkylating agent temozolomide. In serum from GBM patients receiving temozolomide, serial iMER-based detection of exosomal MGMT and MPG mRNAs identified associations between low levels of the transcripts and positive treatment response, and between low serum levels of MGMT mRNA and high tumor levels of MGMT promoter methylation, a known marker of drug response. Next steps including testing the iMER platform in a larger cohort of GBM patients and in other types of cancers...