Expression and clinical significance of tyrosine phosphatase SHP2 in thyroid carcinoma

Protein-tyrosine phosphatase SHP2 is encoded by the gene PTPN11. SHP2 is hypothesized to have a critical role in cancer, via the activation of mutations that have been detected in several types of leukaemia and in certain solid tumours, including liver, breast, gastric and cervical cancer. However, to the best of our knowledge, there have been no previous reports evaluating the significance of SHP2 expression in thyroid cancer. The present study evaluated SHP2 expression in 65 thyroid cancer specimens, 40 specimens of self-matched adjacent peritumour tissues and 40 specimens of normal thyroid tissue, using immunohistochemical and western blot analyses with an anti-SHP2 antibody. Western blotting was also used to assess SHP2 expression in thyroid cancer cell lines (SW579, IHH-4, FTC-133, TPC-1, DRO, TA-K, and ML-1) and Nthy-ori3-1 normal thyroid cells. In addition, SHP2 antisense oligonucleotides were used to block SHP2 expression in SW579 cells, and growth inhibition assays were conducted. Increased SHP2 expression was detected in the tumour tissues compared with that of the normal thyroid tissues (P<0.05). SHP2 expression was significantly correlated with poor tumour differentiation (P<0.05), late TNM stage (P<0.05) and lymph node metastasis (P<0.05), suggesting that SHP2 may represent a potential target for thyroid cancer therapy.