[Analysis of types of P53 gene mutation in gastric cancer tissues].

To study etiology of gastric cancer, polymerase chain reaction-single sequence configuration polymorphism (PCR-SSCP) method was used to analyze the changes of P53 gene in gastric cancer tissues derived from areas with high prevalence of it. Changes in P53 gene occurreds in 45 of 90 specimens of gastric cancer tissues, and 39 of them showed focal mutation and six were deletion and insertion. Among the point mutation, 66.7% were substitution of A to G (G-A) or G to A (A-G), and only 15.5% were substitution of T to G (G-T) or G to T (T-G). These results suggest that there is a close relationship between P53 gene mutation and occurrence of gastric cancer. Based on the characteristics of base pair mutation, it is postulated that methylating carcinogen and polycyclic aromatic hydrocarbon from environment contributed to the above results.