Involvement of non-B cell-derived immunoglobulin G in the metastasis and prognosis of salivary adenoid cystic carcinoma

Cancer cell-derived immunoglobulin G (cancer-IgG) has been implicated in the pathogenesis and progression of various types of cancer. However, its role in salivary adenoid cystic carcinoma (SACC) remains unclear. The present study aimed to investigate the effects of cancer-IgG on metastasis and prognosis in 96 patients with SACC. Immunohistochemical staining showed that cancer-IgG expression was present in all 96 individual SACC tissues. Additionally, high cancer-IgG expression was significantly correlated with metastasis, nerve invasion and recurrence in SACC (P<0.05). Moreover, cancer-IgG expression was significantly correlated with the survival duration of patients with SACC (P<0.05). Proliferation, cell motility and invasion all decreased significantly following knockdown of cancer-IgG in SACC cells (P<0.05) through population-doubling time, wound healing and transwell invasion assays. Additionally, cancer-IgG-knockdown in SACC cells induced the increased expression of E-cadherin and matrix metalloproteinase 9, and promoted the epithelial-mesenchymal transition, but decreased the expression of F-actin filaments. Taken together, these results showed that the high expression of cancer-IgG was strongly associated with metastasis, recurrence and invasion in SACC, suggesting that cancer-IgG expression could serve as a useful biomarker to predict the prognosis of the disease.