Serum miRNA expression is associated with lung cancer in a case-control study and normalizes following surgical resection. Homo sapiens

microRNAs are small, non-coding, single-stranded RNAs between 18-22 nucleotides long that regulate gene expression. Expression of microRNAs is altered in tumor compared to normal tissue; there is some evidence that these changes may be reflected in the serum of cancer cases compared to healthy individuals. Several case-control studies have found evidence of differential levels of serum miRNAs in early stage non-small cell lung cancer (NSCLC) patients but with little consensus on specific miRNAs. Similarly, it is unclear whether miRNAs that show differential levels in tumors are the same miRNAs that are found in serum, and whether surgical resection of tumors leads to normalization of serum miRNA levels in cases. We used Affymetrix arrays to examine serum miRNA expression profiles in a small series of surgically resected non-small cell lung cancer cases to investigate circulating levels of miRNAs. Overall design: We compared global miRNA expression patterns in from patients prior to surgery with levels from 24 controls matched for age, sex, and smoking status. Within the case-patient series, circulating miRNA levels prior to surgery and one and six months post-operatively.