Expression of hMSH2 gene and mutant p53 in sporadic digestive tract tumors.
OBJECTIVE
To investigate the role of mutated mismatch repair gene hMSH2 and mutant p53 gene in the carcinogenesis and development of sporadic digestive tract tumors.


METHODS
hMSH2 gene in normal and tumor tissue of 30 digestive tract tumor specimens was examined using polymerase chain reaction-single strand conformation polymorphism (PCR-SSCP) silver staining. The PCR product with an abnormal strand was sequenced directly. Mutant p53 protein in the tumor tissue was analyzed immunohistochemically.


RESULTS
Six patients were identified as having mutated strands, three on hMSH2 exon 1 and three on hMSH2 exon 5. DNA sequencing revealed that all 6 patients had mutated basic groups that led to decrease in function of the hMSH2 protein. Forty percent (12/30) of patients were p53 positive. The frequency of mutated hMSH2 in p53 positive patients (41.7%) was significantly higher than in p53 negative patients (5.6%, P < 0.05).


CONCLUSIONS
The mutation of hMSH2 plays an important role in the carcinogenesis and development of digestive tract tumors through stimulating p53 mutation.
Kang
Yanjie
Y
Department of Gastroenterology, The Second Hospital of Baoding, Baoding 071051, China.
Zhang
Zhenke
Z
Wang
Junxia
J
Chen
Jing
J
Peng
Bo
B
Kang
Ping
P
D004268:DNA-Binding Proteins; D004067:Digestive System Neoplasms / Q000235:genetics*; D016158:Genes, p53; D006801:Humans; D007150:Immunohistochemistry; D051718:MutS Homolog 2 Protein; D009154:Mutation; D016133:Polymerase Chain Reaction; D018807:Polymorphism, Single-Stranded Conformational; D011518:Proto-Oncogene Proteins / Q000235:genetics*; D016159:Tumor Suppressor Protein p53 / Q000032:analysis
D004268:DNA-Binding Proteins; D011518:Proto-Oncogene Proteins; D016159:Tumor Suppressor Protein p53; C497172:MSH2 protein, human; D051718:MutS Homolog 2 Protein