title: Cyclin D1 and p21 in ulcerative colitis-related inflammation and epithelial neoplasia: a study of aberrant expression and underlying mechanisms.
abstract: It is unclear whether and how cyclin D1 and/or p21(WAF1/CIP1) dysregulation contribute to ulcerative colitis (UC)-related inflammation and colorectal carcinogenesis. Cases of quiescent UC (QUC; n = 15), active UC (AUC; n = 23), UC-related dysplasia (n = 35) and UC-related colorectal adenocarcinomas (CRCs; n = 11) were studied with cyclin D1 and p21(WAF1/CIP1) immunohistochemistry. The CRCs were also studied with beta-catenin, bcl2, and p53 immunohistochemistry, p53 and k-ras mutation analyses, and cyclin D1 gene fluorescence in situ hybridization. QUC showed cyclin D1 (negative/weak staining) and p21(WAF1/CIP1) (surface epithelial and upper-third crypt staining) expression similar to that of normal colorectum. Moderate or strong cyclin D1 immunostaining was seen in 9% of AUC cases, 40% of dysplasia cases, and 36% of UC-related CRCs. Although these carcinomas showed neither cyclin D1 gene amplification nor any association between k-ras mutation and cyclin D1 overexpression, the latter was closely related to nuclear beta-catenin expression. Increased lower-third crypt p21(WAF1/CIP1) staining was seen in 57% of AUC cases; decreased upper-third crypt p21(WAF1/CIP1) staining, in 23% of dysplasia cases; and absent or weak p21(WAF1/CIP1) staining, in 55% of UC-related CRCs. The latter change was always associated with p53 mutation but could not be related to p53 or bcl2 expression. In conclusion, AUC shows up-regulated cyclin D1 and p21(WAF1/CIP1) expression. Cyclin D1 up-regulation and p21(WAF1/CIP1) down-regulation occur early in UC-related carcinogenesis. Cyclin D1 up-regulation is less common in UC-related CRCs than in sporadic CRCs, and is related to beta-catenin nuclear signaling. p21(WAF1/CIP1) down-regulation is seen at an equal or higher frequency among UC-related CRCs compared with sporadic CRCs and is attributable to p53 mutation.
authors.affiliation: Sir Alastair Currie CRC Laboratories, Department of Pathology, University of Edinburgh Medical School, UK.
authors.forename: Newton A C S
authors.initials: NA
authors.lastname: Wong
authors.forename: Nicholas J
authors.initials: NJ
authors.lastname: Mayer
authors.forename: Catriona E
authors.initials: CE
authors.lastname: Anderson
authors.forename: Honora C
authors.initials: HC
authors.lastname: McKenzie
authors.forename: Robert G
authors.initials: RG
authors.lastname: Morris
authors.forename: Joachim
authors.initials: J
authors.lastname: Diebold
authors.forename: Doris
authors.initials: D
authors.lastname: Mayr
authors.forename: Ian W
authors.initials: IW
authors.lastname: Brock
authors.forename: Janice A
authors.initials: JA
authors.lastname: Royds
authors.forename: Hugh M
authors.initials: HM
authors.lastname: Gilmour
authors.forename: David J
authors.initials: DJ
authors.lastname: Harrison
mesh_terms: D000230:Adenocarcinoma / Q000235:genetics / Q000378:metabolism* / Q000473:pathology; D014408:Biomarkers, Tumor / Q000378:metabolism; D002455:Cell Division; D003093:Colitis, Ulcerative / Q000378:metabolism* / Q000473:pathology; D015179:Colorectal Neoplasms / Q000235:genetics / Q000378:metabolism* / Q000473:pathology; D019938:Cyclin D1 / Q000378:metabolism*; D050759:Cyclin-Dependent Kinase Inhibitor p21; D016213:Cyclins / Q000378:metabolism*; D004252:DNA Mutational Analysis; D004273:DNA, Neoplasm / Q000032:analysis; D015536:Down-Regulation; D006801:Humans; D007150:Immunohistochemistry; D009154:Mutation; D016159:Tumor Suppressor Protein p53 / Q000235:genetics / Q000378:metabolism
chemical_list: D014408:Biomarkers, Tumor; C493956:CDKN1A protein, human; D050759:Cyclin-Dependent Kinase Inhibitor p21; D016213:Cyclins; D004273:DNA, Neoplasm; D016159:Tumor Suppressor Protein p53; D019938:Cyclin D1