Clinicopathological Significance Of The Expression Of CDK4,c-Myc,CDC25A And Smad4 In Gastric Carcinoma

Objective: To study the clinicopathological significance of the expression of CDK4,c-Myc,CDC25A and Smad4 in gastric carcinoma. To investigate the correlation of the expression of CDK4,c-Myc,CDC25A and Smad4 with clinical pathological characteristics in gastric carcinoma . To investigate the corelation between CDK4,c-Myc,CDC25A and Smad4. Provide abnormality of many genes involved the regulatory pathway of CDK4,c-Myc,CDC25A and Smad4 in the molocular mechanism of gastric carcinogenesis.Methods: Immunohistochemical technique SP was used to .examine the expression of CDK4,c-Myc,CDC25A and Smad4 in 40 cases of gastric carcinomas and their surrounding tissues (3cm distanced) . 15 patients are diagnosed as benign lesions (like ulcer, trauma, perforation, etc). The levels the expression were analyzed combined with clinicopathological features of the patients including age, the cases, tumor size, infiltration depth, differentiation degree, histology type, lymph node metastasis.Results: Buffy color staining found in cytoplasms and/or nucleus was recognized as positive. CDC25A located in nucleus and Smad4 located in cytoplasms and CDK4 in cytoplasms or nucleus except, c-Myc was in cytoplasm. Overexpression of CDC25A and CDK4 revealed in 35/40 samples(87.5%)and 18/40 samples(45.0%)of carcinoma respectively which showed a negative correlation with tumor differentiation(P<0.05).The expression of CDC25A was lower in high and moderate differentiation degree than those in poor differentiation degree and the rate of positive expression was 75.0%(15/20)and 100.0%(20/20)respectively (P<0.05).The expression of CDK4 was lower in high and moderate differentiation degree than those in poor differentiation degree and the rate of positive expression was 60.0%(12/20)and 30.0%(6/20)respectively(P<0.05). The expression percent of CDC25A and CDK4 was 100.0%(19/19)and 42.1%(8/19)respectively in lymph node metastatic cancer whereas only 44.0%(16/21)of CDC25A and 32.0% ( 10/21 ) of CDK4 expression were shown in non-metastatic cancer(P<0.05). The over expression rate of CDC25A and CDK4 in cancer tissues were significantly higher than that in tumor-adjacent and normal tissues(P <0.05).The expression of CDC25A and CDK4 was 50.0%(20/40) and 22.5%(9/40)respectively in the surrounding tissues of 3cm distance which showed unsignificantly higher than that in normal tissues and the rate of positive expression was 20.0%(3/15)and 6.7%(1/15)respectively(P>0.05). The positive rates of c-Myc was 70.0%(28/40)in samples of gastric carcinomas. The expression percent of c-Myc was 54.2%(13/24) in non-metastatic cancer whereas only 54.2%(13/24)in lymph node metastatic cancer(P<0.05).The postive rate of c-Myc was 32.5%(13/40)and 6.7%(1/15)in the surrounding tissues of 3cm distance and normal tissues respectively(P>0.05).The incidence of c-Myc was significantly lower in cancer tissues than that in cancer(P<0.05). The postive rate of Smad4 was 52.5%(21/40)and 66.7%(10/15)in the surrounding tissues of 3cm distance and normal tissues respectively(P>0.05).The incidence of Smad4 was significantly lower in cancer tissues than that in normal tissues(P<0.05).There were no significant differences in the age and sex of the cases, infiltration depth mucles ,the size of the tumor of the expression of CDC25A, CDK4, c-Myc and Smad4 (P>0.05). There is a positive relationship between CDC25A and CDK4, c-Myc and CDC25A, c-Myc and CDK4(P<0.05). There is a negative relationship between CDC25A and Smad4 in this samples(P<0.05).Conclusion: Over expression of CDC25A and CDK4 exsist in gastric carcinoma and show a good relation with tumor differentiation and lymphnode metastasis. Over expression of c-Myc exsist in gastric carcinoma and show a good relation with tumor differentiation and lymphnode metastasis. Lower expression of Smad4 in gastric carcinoma and show a good relative with lymphnode metastasis, umor differentiation. CDC25A expression maybe regulated by Smad4. Both the over expression of CDC25A and the lower expression of c-Myc coexist in the development of gastric carcinoma. Abnormality of many genes involved in the regulatory pathway of CDC25A, c-Myc, CDK4 and Smad4 maybe involved in the molocular mechanism of gastric carcinogenesis.