Expressions Of NGF And Its Receptors In Adenoid Cystic Carcinoma Of Salivary Gland And Relationship Between Them And Perineural Invasion

Salivary adenoid cystic carcinomas ( SACC) are common malignant neoplasms of head and neck tumors, representing about 24% of malignant tumors of salivary gland. The clinical course of SACC is lengthy, characterized by late local recurrence and perineural spread. Pain, anaesthesia and facial paralysis are common in SACC patients.Nerve growth factor ( NGF ) is a neurotrophic protein . That and its receptors ( TrkA and p75NTR ) play important pole on tumor growth , tumor invasion , and the formation of metastases. In the present study, the expression of NGF, TrkA and p75NTR in adenoid cystic carcinoma( ACC) of salivary gland was investigated by immunohistochemistry method, and the relation between them and perineural invasion was discussed.Materials and MethodsTwenty-one cases of primary ACC of the head and neck were retrieved from the Department of oral and maxillofacial surgery of the first affiliated hospital of china medical university between 1987 and 2001. all specimens were diagnosed ACC by two pathologists according to WHO criteria 1991. The eight control specimens were from normal salivary gland tissue. Clinical information was obtained from the hospital records, including male 13,female 8 with a median age47. 3 years. Sites of involvement included the parotid gland (6 cases) , subman-dibular gland ( 5 ) , sublingual gland ( 3 ) , palate ( 5 ) , tongue ( 1 ) , and lip (1).. The expressions of NGF, TrkA and p75NTRin adenoid cystic carcinoma (ACC) of the salivary gland was measured by StreptAvidin-Biotin Complex ( SABC). Immunohistochemistry was performed according to manufactuer's recommendations using rabbit polyclonal antibody to NGF , TrkA and p75NTR. All data were analyzed with X test.ResultsNo NGF, TrkA and p75OTR staining in acinus of normal salivary glands, but NGF ( + ) 6 cases in duct cell. In ACC cell, NGF( + ) 17cases, p75NTR( + ) 16 cases. There was no staining of TrkA in tumor. p75 was also found in nerve fibers. The positive stain of NGF in tumor cell was 78% ,85% and 80% respectively in the cribriform , tubular and solid. The p75NTR was 88% , 83% and 60% respectively. There were no statistically difference.Conclusions1. There was expression of NGF in duct cell of normal gland.2. There were expressions of NGF and p75NTRin ACC cell. They may promote the invasion and distant metastases by matter of autocrine and/or parac-rine.3. The expressions of NGF and p75NTR was no association with histopatho-logic type.4. The expressions of NGF was found in nerve fibers adjacent to tumor. This suggested that there were interaction between ACC and nerve fibers by NGF and its receptors.