Significance Of Nm23, P53 And CerbB-2 Protein Expression In Human Gastric Carcinomas

Objective : Gastric cancer is the most common malignant tumor in our country. Even with the highest mortality, its pathogenesis has not been identified completely. Recent researches show that multiple progressive steps promote the development of gastric cancer and it is closely related with the activation of oncogenes and deactivation of anti-oncogenes. From clinical observation, we know that the most important factors dominating prognosis are cancer cells proliferating depth, cell differentiation, lymphatic gland metastasis and pathological stages. Finding some valuable molecular parameters will have significant importance in the treatment of gastric cancer. The purpose of this research is possible relationship between the gene expression of nm23, p23 and CerbB-2 and the common clinical gastric parameters, like clinical stages, lymphatic node metastasis, and infiltration depth, trying to find some reliable detecting molecular parameters for common clinical usage.Methods : nm23, p23 and CerbB-2 expression were examined with S-P immunohistochemistry in 81 gastric cancer specimen in our hospital. Paraffinned sections were set in the baker overnight at 60℃,deparaffinned in dimethyl benzene,gradient alcohol hydration,3% peroxidase treatment was performed at room temperature for 10 minutes to deactivate the endogenous peroxide enzyme. After blockage in 1% calf serum at room temperature for 10 minutes, the sections were incubated with the first antibody overnight in 4℃refrigerator;then rinsed 3 times with PBS, the sections were incubated with the second antibody at room temperature for 10 minutes,add streptomycin-antibiotin-peroxidase solution,incubated at room temperature for 10 minutes. Colorization was performed with DAB,and after fully washing with tap water and recolorated with hematoxylin, the sections were dehydrated and made transparency, and finally sealed with neutral resin. PBS was used as the first antibody in negative control group.Results : The positive expression rate of nm23, p53 and CerbB-2 in the 81 gastric specimen were 50.6%(41/81),63.0%(51/81) and 65.4%(53/81) respectively, with no relation to patients gender, age and the size of the tumor(P>0.05); A negative relationship was found between nm23 expression and gastric cancer cell infiltration depth, lymphatic node metastasis and the clinical stages (P<0.05); the positive p53 expression rate had a positive relationship with gastric cancer infiltration, gastric cancer cell differentiation and the clinical stages (P<0.05); the positive CerbB-2 expression rate had a positive relation with the gastric cell infiltration depth (P<0.0.5). Compared with no or only single gene expression of nm23, P53 and CerbB-2, either two or more than two gene expression of nm23, P53 and CerbB-2 had significant relationship with gastric cancer cell infiltration depth and the clinical stages.Conclusions : 1. this study proves that nm23 exists in cytoplasm , while p53 is an intracellular molecule and CerbB-2 mainly exists on cytomembrane with less part in cytoplasm.2. the expression of nm23 has a negative relationship with gastric cancer cell infiltration depth, lymphatic node metastasis and the clinical stages; the positive p53 expression rate has a positive relationship with gastric cancer infiltration, cancer cell differentiation and the clinical stages; the positive CerbB-2 expression rate had a positive relation with the gastric cell infiltration depth.3.Compared with no or only single gene expression of nm23, P53 and CerbB-2, either two or more than two gene expression of nm23, P53 and CerbB-2 had significant relationship with gastric cancer cell infiltration depth and the clinical stages, suggesting the lower expression of nm23 and the increased expression of p53 and/or CerbB-2 indicate a poor prognosis for a gastric cancer patient.