The role of micro-RNA genes in papillary thyroid carcinoma. Homo sapiens

We show that numerous miRNAs are transcriptionally up-regulated in papillary thyroid carcinoma (PTC) tumors compared with unaffected thyroid tissue. Among the predicted target genes of the three most upregulated miRNAs (miRs 221, 222 and 146b), only less than 15% showed significant downexpression in transcript level between tumor and unaffected tissue. The KIT gene which is known to be downregulated by miRNAs 221 and 222 displayed dramatic loss of transcript and protein in those tumors that had abundant mir-221, mir-222, and mir-146b transcript. Keywords: Disease state analysis Overall design: Total RNA was extracted from paired tumor and normal thyroid tissues from 9 PTC patients. The same set samples were applied to Custom miRNA microarray chips (OSU_CCC version 2.0) and Affymetrix HG-U133 plus 2 chips.