Thymidylate Synthase, a New Myoepithelial Biomarker for Breast Lesions

[Expression of thymidylate synthase in salivary adenoid myoepithelial cells and its clinical significance]

OBJECTIVE

To evaluate the expression of thymidylate synthase (TS) in myoepithelial cells (MECs) of salivary adenoid tissues and explore its clinical significance.

METHODS

Immunohistochemical staining EnVision method was used to detect the expression of TS, P63, Calponin, CK5/6 and S-100 in 32 salivary gland specimens, including 10 non-neoplastic and salivary inflammation specimens, 11 mixed tumor specimens, 5 basal cell carcinoma specimens and 6 adenoid cyst carcinoma specimens. The specificity and sensitivity of TS as a specific molecular marker of salivary muscle epithelial cells were evaluated in comparison with P63, Calponin, CK5/6 and S-100.

RESULTS

The expression pattern of TS in all the salivary gland tissue specimens was identical with that of p63. TS and P63 both showed strong immunohistochemical expressions in MECs of salivary adenoid tissue specimens. Calponin, CK5/6, and S-100 showed cytoplasmic/membranous expressions in the MECs. In addition, TS exhibited weak or moderate cytoplasmic expression in a few salivary gland epithelial cells, cancer cells and scattered stromal cells, with negative expression in the cell nuclei. The expression of TS in the MECs of all the salivary adenoid specimens was highly consistent with those of P63, Calponin, CK5/6 and S-100 (P>0.05) Except for CK5/6 expression in Salivary inflammation and Salivary gland specimens. Kappa>0.75. The specificity and sensitivity of TS as a molecular marker of MECs were both 100%.

CONCLUSIONS

TS is a new specific marker of MECs for differential diagnosis of salivary gland tumors.