Expression of NGF, p75 and TrKA in adenoid cystic carcinoma of salivary glands

ObjectiveTo study the possible mechanism of regulation of invasion and differentiation of adenoid cystic carcinoma(ACC) by nerve growth factor(NGF)and NGF receptors (p75,TrkA). MethodsThe expressions of NGF, p75 and TrKA were detected by immunohistochemistry in 42 cases of ACC of salivary glands and normal salivary glands.The expression of NGF and receptors in 3 types of ACC was different.The discrepancy was analyzed through chi-squared test.ResultsThe positive rate of NGF, p75 and TrkA in ACC was 88.1%(37/42), 83.3%(35/42) and 85.7%(36/42) respectively.There was no significant difference between cribriform type and tubular type of ACC;NGF and p75 contents showed highly significant difference between cribriform-atubular type and solid type of ACC(P 0.001);TrKA content showed significant difference between cribriform-tubular type and solid type of ACC(P 0.05).In normal salivary glands,NGF was detected in intercalated duct cells,striated duct cells and epithelial cells of excretory duct.Conclusions①Differentiation of ACC may be regulated by autocrine of NGF;②p75 reaction on NGF may be the cause of high invasive ability of ACC and may be the cause of neurotropism of ACC.