OBJECTIVETo investigate the expression of p38 mitogen-activated protein kinase (p38MAPK) in salivary adenoid cystic carcinoma (SACC) tissues and their clinicopathologic significance.

METHODSThe protein and mRNA expressions of p38MAPK were examined by immunohistochemistry and in situ hybridization, respectively, in 52 cases of SACC and in 11 normal salivary gland tissues adjacent to the tumors on a tissue microarray platform.

RESULTSThe positive rate of p38MAPK protein expression in the paracancerous normal salivary gland tissues and that in SACC were 36.4% and 96.2%, respectively, showing a significant statistical difference (P < 0.01). The protein expression of p38MAPK was positively correlated with the lymph node metastasis and nerve involvement (P < 0.05). The positive rates of p38MAPK mRNA in the paracancerous tissues and in the SACC tissues were 45.5% and 94.2%, respectively, with a significant statistical difference (P < 0.01). The mRNA expression of p38MAPK was positively correlated with the lymph node metastasis and nerve involvement (P < 0.05). In the SACC, there was a notable positive correlation between the p38MAPK protein and mRNA expressions (r = 0.409, P < 0.01).

CONCLUSIONSThe expression of p38MAPK is up-regulated in salivary adenoid cystic carcinoma. p38MARK may be involved in the tumorigenesis, development and metastasis of this cancer.