title: [Expression of cyclooxygenase-2 and relationship with mismatch repair gene and microsatellite instability in hereditary non-polyposis colorectal cancer].
abstract: OBJECTIVE
  To investigate the expression of Cyclooxygenase (COX)-2 and the relationship between cox-2, mismatch repair gene (MMR) proteins and microsatellite instability (MSI) in HNPCC.
  
  
  METHODS
  Twenty-eight cases of adenomas and 14 cases of carcinomas were collected from 33 HNPCC families patients by colonoscopy. Sporadic adenomas (n = 32) and carcinomas (n = 24) were used as a control group. The expressions of COX-2 and mismatch repair gene hMLH1, hMSH2, hMSH6 proteins were examined by immunohistochemistry. MS1 were analyzed by using PCR with BAT25, BAT26, D2S123, D5S346 and D17S250 loci.
  
  
  RESULTS
  The COX-2 high-expression rates were 53.6% (15/28) and 42.9% (6/14) in HNPCC adenomas and carcinomas, and were 62.5% (20/32) and 91.7% (22/24) in sporadic adenomas and carcinomas. COX-2 expression was lower in HNPCC carcinomas than that of sporadic carcinomas (P < 0.05). MMR deficiency rate and positive rate of MSI-H were both 71.4% (10/14) respectively in HNPCC carcinomas. It was higher than that in sporadic colorectal carcinomas [both 12.5% (3/24)]. Eight (80.0%) COX-2 low-expression were observed in 10 HNPCC carcinomas with MMR-deficient system while 4 cox-2 high-expression cases were observed in 4 HNPCC carcinomas with MMR-proficient system. COX-2 expression was lower in HNPCC carcinomas and adenomas, sporadic carcinomas with MMR-deficient system than that of MMR-proficient (P < 0.05). The COX-2 low-expression rates were 80.0% (8/10), 66.7% (12/18) and 66.7% (2/3) in HNPCC adenomas, HNPCC carcinomas and sporadic carcinomas with MSI-H. Cox-2 expression was lower in HNPCC and sporadic carcinomas (adenocarcinomas) with MSI-H than that of MSS (P < 0.05).
  
  
  CONCLUSIONS
  Compared with sporadic carcinomas, the COX-2 expression was lower in HNPCC carcinomas. There was negative correlation between COX-2 expression and MMR-deficient (MSI-H). The detection of COX-2, MMR protein and MSI is of important significance in further studying the pathogenesis and interventional therapy of colorectal neoplasms.
authors: Department of Gastroenterology, General Hospital of Beijing Military Command, Beijing 100700, China.
authors: Ying-hui
authors: YH
authors: Zhang
authors: Jian-qiu
authors: JQ
authors: Sheng
authors: Hong-gang
authors: HG
authors: Geng
authors: Min
authors: M
authors: Han
authors: Ji-sheng
authors: JS
authors: Huang
authors: Hong
authors: H
authors: Mu
authors: Wen-liang
authors: WL
authors: Han
authors: Ji-gui
authors: JG
authors: Chen
authors: Hong-li
authors: HL
authors: Niu
authors: Ai-qin
authors: AQ
authors: Li
authors: Zi-tao
authors: ZT
authors: Wu
authors: Shi-rong
authors: SR
authors: Li
mesh_terms: D048868:Adaptor Proteins, Signal Transducing / Q000378:metabolism; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D003123:Colorectal Neoplasms, Hereditary Nonpolyposis / Q000235:genetics* / Q000378:metabolism*; D051546:Cyclooxygenase 2 / Q000378:metabolism*; D053843:DNA Mismatch Repair; D004268:DNA-Binding Proteins / Q000378:metabolism; D005260:Female; D015972:Gene Expression Regulation, Neoplastic; D006801:Humans; D053842:Microsatellite Instability; D008875:Middle Aged; D000070957:MutL Protein Homolog 1; D051718:MutS Homolog 2 Protein / Q000378:metabolism; D009687:Nuclear Proteins / Q000378:metabolism; D055815:Young Adult
chemical_list: D048868:Adaptor Proteins, Signal Transducing; D004268:DNA-Binding Proteins; C094443:G-T mismatch-binding protein; C501486:MLH1 protein, human; D009687:Nuclear Proteins; D051546:Cyclooxygenase 2; C496540:PTGS2 protein, human; C497172:MSH2 protein, human; D000070957:MutL Protein Homolog 1; D051718:MutS Homolog 2 Protein