Expression of activation-induced cytidine deaminase in ulcerative colitis-associated carcinogenesis.
OBJECTIVE
Activation-induced cytidine deaminase (AID) is a DNA/RNA-editing enzyme that is essential for hypermutation and class-switch recombination in immunoglobulin genes. The aim of this study was to investigate the expression of AID and its association with p53 mutation in ulcerative colitis (UC)-associated carcinogenesis.


RESULTS
The expression of AID was examined in 25 patients with UC-associated neoplasia, 20 UC patients without neoplasia, 18 patients with non-inflamed colorectal mucosa unaffected by UC, and 19 patients with sporadic colorectal cancer, by immunohistochemistry and quantitative reverse transcription polymerase chain reaction analysis. Mutational analysis and immunohistochemistry for p53 were also performed. The degree of AID expression was not different between UC-associated neoplasia and sporadic colorectal cancer. However, AID was expressed in both UC-associated neoplasia and UC without neoplasia. Whereas AID expression in UC-associated neoplasia was not correlated with the grade of dysplasia, expression in non-neoplastic mucosa of UC was correlated with the histological grade of inflammation. In UC-associated neoplasia, there was no significant correlation between AID expression and p53 mutation.


CONCLUSIONS
AID is associated with inflammation in UC, whereas it may not specifically contribute to carcinogenesis in UC.
Department of Anatomic Pathology, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan.
Masaki
M
Gushima
Minako
M
Hirahashi
Takayuki
T
Matsumoto
Kouhei
K
Fujita
Kenoki
K
Ohuchida
Yoshinao
Y
Oda
Takashi
T
Yao
Mitsuo
M
Iida
Masazumi
M
Tsuneyoshi
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D014408:Biomarkers, Tumor / Q000032:analysis*; D002471:Cell Transformation, Neoplastic / Q000235:genetics / Q000378:metabolism*; D003093:Colitis, Ulcerative / Q000201:enzymology* / Q000235:genetics / Q000473:pathology; D003110:Colonic Neoplasms / Q000201:enzymology* / Q000235:genetics / Q000473:pathology; D003564:Cytidine Deaminase / Q000096:biosynthesis*; D004252:DNA Mutational Analysis; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D007249:Inflammation / Q000201:enzymology / Q000235:genetics / Q000473:pathology; D008297:Male; D008875:Middle Aged; D060787:Neoplasm Grading; D009367:Neoplasm Staging; D020133:Reverse Transcriptase Polymerase Chain Reaction; D016159:Tumor Suppressor Protein p53 / Q000235:genetics; D055815:Young Adult; D000098830:AICDA (Activation-Induced Cytidine Deaminase)
D014408:Biomarkers, Tumor; D016159:Tumor Suppressor Protein p53; D000098830:AICDA (Activation-Induced Cytidine Deaminase); D003564:Cytidine Deaminase