Abnormality of ras gene family was studied in a total of 206 cases of gastric cancer and precancerous lesions by PCR-RFLP, PCR-SSCP and DNA sequencing. The results showed that mutation rate of H-ras 12 codon in metapl...Abnormality of ras gene family was studied in a total of 206 cases of gastric cancer and precancerous lesions by PCR-RFLP, PCR-SSCP and DNA sequencing. The results showed that mutation rate of H-ras 12 codon in metaplasia,atypical hyperplasia, early-stage cancer and advanced cancer was 16. 7%, 31. 2 %, 50. 0%, and 32. 2%, respectively. In the groups of superficial gastritis and normal controls, no mutation were detected in codon 12 of ras. Mutations of Hras 61 codon and N-ras 12 codon in various groups were the same as those in normal control. K-ras 12 codon mutation was detected in only 2 cases of gastric cancer by using PCR-SSCP, but it was not detected by DNA sequencing, which may be polymorphism. All H-ras 12 codon mutations were G→T mutation. There were significant difference between the groups of metaplasia, dysplasia, gastric carcinoma and normal control group (P<0.05, P<0.01, P<0.01,respectively). It was concluded that H-ras 12 codon mutation was an early event and may play an important role in gastric carcinogenesis. Although K-ras, N-ras mutation rates are high in colon cancer and leukemia, it seems to bear no relationship with gastric cancer.展开更多
We examined the incidence of point mutation in codon 12 of Ki-ras oncogene in human colorectal carcinomas by polymerase chain reaction in combination with alot-blot hybridization using mutation-specific ollgodeoxynucl...We examined the incidence of point mutation in codon 12 of Ki-ras oncogene in human colorectal carcinomas by polymerase chain reaction in combination with alot-blot hybridization using mutation-specific ollgodeoxynucleotide as probes. Among 72 colorectal carcinomas, point mutations were found in 36 samples, GGT to TGT in 16 cases and to AGT In 21 cases, one sample contain two different mutations. One of five normal mucosa contains the same mutation as in the adjacent carcinoma, suggesting that genetic alterations may also exist in the regions from which such carcinomas arise.展开更多
文摘Abnormality of ras gene family was studied in a total of 206 cases of gastric cancer and precancerous lesions by PCR-RFLP, PCR-SSCP and DNA sequencing. The results showed that mutation rate of H-ras 12 codon in metaplasia,atypical hyperplasia, early-stage cancer and advanced cancer was 16. 7%, 31. 2 %, 50. 0%, and 32. 2%, respectively. In the groups of superficial gastritis and normal controls, no mutation were detected in codon 12 of ras. Mutations of Hras 61 codon and N-ras 12 codon in various groups were the same as those in normal control. K-ras 12 codon mutation was detected in only 2 cases of gastric cancer by using PCR-SSCP, but it was not detected by DNA sequencing, which may be polymorphism. All H-ras 12 codon mutations were G→T mutation. There were significant difference between the groups of metaplasia, dysplasia, gastric carcinoma and normal control group (P<0.05, P<0.01, P<0.01,respectively). It was concluded that H-ras 12 codon mutation was an early event and may play an important role in gastric carcinogenesis. Although K-ras, N-ras mutation rates are high in colon cancer and leukemia, it seems to bear no relationship with gastric cancer.
文摘We examined the incidence of point mutation in codon 12 of Ki-ras oncogene in human colorectal carcinomas by polymerase chain reaction in combination with alot-blot hybridization using mutation-specific ollgodeoxynucleotide as probes. Among 72 colorectal carcinomas, point mutations were found in 36 samples, GGT to TGT in 16 cases and to AGT In 21 cases, one sample contain two different mutations. One of five normal mucosa contains the same mutation as in the adjacent carcinoma, suggesting that genetic alterations may also exist in the regions from which such carcinomas arise.
