Relationship of Methylation Status and mRNA Expression of PTEN, RASSF1A in Peripheral Blood with Thyroid Nodule Disease

Objective To observe the methylation status and mRNA expression of PTEN, RASSF1A in the peripheral blood of thyroid nodule patients and to explore the relationship between these genes and the clinical characteristics.

Methods Methylation-specific PCR(MSP) was used to detect the hypermethylation status of PTEN, RASSF1A promoter in the peripheral blood from 46 cases of nodular goiter, 34 cases of thyroid adenoma, 24 cases of papillary thyroid carcinoma(PTC) and 30 healthy controls. The mRNA expression of PTEN and RASSF1A was tested by reverse-transcription polymerse chain reaction.

Results (1) The methylation rates of PTEN, RASSF1A between thyroid adenoma, PTC and normal controls had significant difference (P < 0.05). (2) The positive mRNA expression rates of PTEN and RASSF1A between thyroid adenoma, PTC and normal control had significant difference (P < 0.05). (3)The methylation status, mRNA expression of PTEN and RASSF1A in PTC were correlated with lymph node metastasis (P < 0.05), and were not correlated with age, gender, size of nodule.

Conclusion The hypermethylation, and hence functional inactivation of tumor suppressor genes PTEN, RASSF1A are common in peripheral blood of thyroid tumors, which play an important role during the occurrence and development of thyroid tumors.