Elevated TARP promotes proliferation and metastasis of salivary adenoid cystic carcinoma

Objective. This study aims to analyze the expression of T-cell receptor gamma chain alternate reading frame protein (TARP) in salivary adenoid cystic carcinoma (SACC) and its distant metastases and to investigate its influences on the development and progression of SACC. Study Design. TARP expression was analyzed in 50 primary SACCs, 13 specimens of metastatic adenoid cystic carcinoma of salivary gland origin, and 20 noncancerous tissues around SACC via immunohistochemistry. Cell Counting Kit-8 tests, wound healing assay, and Transwell experiments were performed to evaluate the effects of lentivirus-mediated TARP overexpression on the proliferation, migration, and invasion of SACC cells. Results. TARP expression was significantly increased in primary SACCs compared with adjacent noncancerous tissues, and this increase was further enhanced in metastases compared with primary SACCs. The expression level of TARP correlated significantly with tumor size, tumor-node-metastasis stage, perineural invasion, histologic type, and distant metastasis. Furthermore, TARP overexpression promoted the growth, migration, and invasion of SACC cells. Conclusions. TARP plays an important role in and may be used as a marker to indicate the development and progression of SACC.