90th Annual Meeting Abstracts
microRNA Modulation of Gene Expression in Thyroid Cancer
Hyunsuk Suh, MD
Boston University, Somerville, MA
Objective:To identify microRNA modulation in thyroid cancer tumorigenesis. We hypothesize that microRNA 222 may negatively regulate E-cadherin leading to decreased cell-cell adhesion and increased malignant potential in papillary thyroid cancer
Design:In vitro study of established thyroid cancer cell lines and fine needle aspiration (FNA) specimens
Setting: Academic tertiary referral center.
Patients:FNA specimens collected with consents.
Interventions:Transfection of cancer cells with specific anti-microRNA to knock out specific target microRNA.
Main Outcome Measures:Gene expression analysis via qRT-PCR, Western blot, Cell Proliferation and Cell invasion Assay.
Results:Thyroid cancer cell lines and FNA specimens were profiled for microRNAs 221, 222, 15 16, and microRNA processing molecules drosha & dicer using microarray and qRT-PCR. Cell lines that had over-expression of miR222 were transfected with antimiR 222. At 48h and 96h, miR222 levels were reduced by 3.93±0.053 fold and 13.32±.01 fold, respectively. Potential target mRNAs, AP2α and ckit levels were increased by 1.34±0.17 fold and 1.97±0.26 fold, respectively. Furthermore, mRNA level of a downstream molecule ECDH was increase by 1.59±0.45 fold. Subsequent cell proliferation analysis showed transient but statistically significant decrease in cell viability at 48h (54.6%). However, by 72h and 96h post-transfection, cell viabilities have normalized. A biological relevance of transfection was further tested by invasion assays, which have demonstrated that miR222 transfected cells have 46.1±0.16% and 37.7±0.076% reduction at 72 and 96h, respectively
Conclusions:MicroRNA 222 are generally over-expressed in papillary thyroid cancer cells and may play an important role in thyroid cancer tumorigenesis and metastasis. Transfection of antimiR222 leads to decreased level of miR 222 and rate of metastasis in papillary thyroid cancer cells without altering the cell viability