MicroRNA profiling of human papillary thyroid carcinoma and normal thyroid to assess the role of miRNA genes in papillary thyroid carcinoma

ABSTRACT: Apart from alterations in the RET/PTC-RAS-BRAF pathway, comparatively little is known about the genetics of papillary thyroid carcinoma (PTC). We show that numerous miRNAs are transcriptionally up-regulated in PTC tumors compared with unaffected thyroid tissue. A set of 5 miRNAs including the 3 most upregulated ones (miRs 221, 222, 146) distinguished unequivocally between PTC and normal thyroid. Additionally, miR-221 was upregulated in unaffected thyroid tissue in several PTC patients, presumably an early event in carcinogenesis. Tumors in which the upregulation (11-19 fold) of miRs 221, 222 and 146 was strongest showed dramatic loss of KIT transcript and Kit protein. In five of 10 such cases this was associated with germline single nucleotide changes in the two recognition sequences in KIT for these miRNAs. We conclude that upregulation of several miRs and down regulation of KIT are involved in PTC pathogenesis, and that sequence changes in genes targeted by miRNAs can contribute to their downregulation.

INSTRUMENT(S): Scanning hardware

ORGANISM(S): Homo sapiens

SUBMITTER: George Calin 

PROVIDER: E-TABM-68 | biostudies-arrayexpress |

REPOSITORIES: biostudies-arrayexpress