Expressions Of NGF And Its Receptor TrkA In Gastric Cancer And Their Relationship With Perineural Invasion

Objective:1To detect the expression of NGF and its receptor TrkA in gastriccancer tissues and to investigate the possible mechanism and theirrelationship with clinical pathological features and the character ofperineural invasion．2To detect matrix metalloproteinases-7(MMP-7),heparanase (HPA)expression in gastric cancer tissues and adjacent tissues byimmunohistochemical staining, and analyze their relationships with NGFand TrkA, to explore their roles in progression of gastric cancer and toevaluate their clinic pathologic significances．Methods:The expressions of NGF,TrkA，MMP-7and HPA were detected in gastriccancer tissues and adjacent tissues by immunohistochemical stainin，and werecompared with the clinic-pathological data.To observe the relationshipbetween the positive rates of these markers expression and perineural invasionand metastasis.Results:1Positive rates of expression for NGF and TrkA (63.64％,77.27％)ingastric cancer tissues are obviously higher than that in adjacent tissues(6.06％,77.27％).The expressions of two proteins showed a significantdifference(P<0.05).Both NGF and TrkA expressed positively in cell envelopeand cell-substance.In nerve fibers NGF expressed positively.TrkA can alsohave a weak expression in the nerve fiber or not.what’s more，the nearer tonerve fibers，the more strongly stained．The positive rates of NGF and TrkAexpression in patients with gastric cancer tissues with perineural invasion were higher than that without perineural invasion.2MMP-7,HPA mainly expressed in cell envelope and cellsubstance.Positive rates of expression for MMP-7、HPA (89.39%,71.21%)in gastric cancer tissues are obviously higher than that in adjacent tissues(9.09%、12.12％)in adjacent tissues.The expressions showed a significantdifference(P<0.05). Of the gastric cancer, the positive intensities of MMP-7and HPA were associated with the depth of invasion and clinicopathologicalstages as well as with or without the lymph node metastasis (P<0.05),but theydid not correlated with sex,age and tumor size(P>0.05);The MMP-7and HPAexpressions were stronger in those having perineural invasion than thosewithout perineural invasion.3The expression of NGF was positively related to TrkA、MMP-7、HPA(r=0.268,0.563,0.280;P<0.05); The expression of TrkA was positivelyrelated to MMP-7、HPA(r=0.436,0.410;P<0.05)．In addition,there was positivecorrelation between expression of MMP-7and HPA(r=0.500;P<0.05).Thepositive rate of perineural invasion was significantly positive correlated withthe expression of MMP-7and HPA (r=0.564,0.372;P<0.05)；What’s more, theexpressions of these four proteins were positively related to PNI (r=0.443,0.292,0.564,0.372;P<0.05).Conclusion:1The expression for NGF and TrkA in gastric cancer tissues areobviously higher than that in adjacent tissues，and their expression in patientswith gastric cancer tissues with perineural invasion were higher than thatwithout perineural invasion. So NGF and its receptor TrkA played importantparts in the process of perineural invasion of the gastric cancer． Thecombination of them provided the relative growth momentum between tumorcells and nerve.2The same time as the NGF from nerve fiber move towards TrkA fromtumor cells，the NGF from tumor cells can incorporation with TrkA fromtumor cells,that can enhance the invasion capability of tumor cells throughimproving the expressions of MMP-7and HPA．Eventually lead to PNI phenomenon happening.3The expression of NGF、TrkA、MMP-7and HPA had pertinencerelation,it was prompt that NGF、TrkA、MMP-7and HPA were involved in theprocess of development and metastasis of gastric cancer,to promote theprocess of perineural invasion. Detecting the expressions of these cancermight play an important role in diagnosing the malignant degree of gastriccancer and biological behavior,and it has an important significance to evaluatethe choice of treatment and the prognosis of gastric cancer.