title: Differential expression of the AP-1 transcription factor family members in human colorectal epithelial and neuroendocrine neoplasms.
abstract: We immunohistochemically examined 75 human colorectal neoplasms (adenoma, 27; adenocarcinoma, 24; neuroendocrine carcinoma, 24) for the expression of activator protein (AP)-1 family proteins. Nuclear and cytoplasmic expression levels of c-Jun and Fra-1 proteins were markedly elevated in adenomas, adenocarcinomas and neuroendocrine carcinomas compared with nonneoplastic colorectal epithelial cells. JunB also was overexpressed in these tumors but with a predominantly cytoplasmic staining pattern. Overexpression of Fra-2 was evident in carcinomas but less frequent in adenomas. Expression levels of JunD and c-Fos were high in nonneoplastic colorectal epithelial cells and remained so in neoplasms. FosB was undetectable in nonneoplastic and neoplastic colorectal tissues. Neuroendocrine carcinomas exhibited an AP-1 expression profile similar to adenocarcinomas except for infrequent overexpression of c-Jun in poorly differentiated variants. Hierarchical clustering separated the majority of malignant from benign tumors based on AP-1 expression patterns. AP-1 transcription factor family members are expressed differentially in nonneoplastic and neoplastic colorectal tissues. Up-regulation of c-Jun and Fra-1 is an early event in human colorectal tumorigenesis. Overexpression of Fra-2 may participate in tumor progression.
authors.affiliation: Department of Medicine, Washington University School of Medicine, St Louis, MO 63110-1093, USA.
authors.forename: Wanghai
authors.initials: W
authors.lastname: Zhang
authors.forename: John
authors.initials: J
authors.lastname: Hart
authors.forename: Howard L
authors.initials: HL
authors.lastname: McLeod
authors.forename: Hanlin L
authors.initials: HL
authors.lastname: Wang
mesh_terms: D000230:Adenocarcinoma / Q000378:metabolism / Q000473:pathology; D000236:Adenoma / Q000378:metabolism / Q000473:pathology; D000368:Aged; D000369:Aged, 80 and over; D014408:Biomarkers, Tumor / Q000032:analysis*; D018278:Carcinoma, Neuroendocrine / Q000378:metabolism* / Q000473:pathology; D016000:Cluster Analysis; D015179:Colorectal Neoplasms / Q000378:metabolism* / Q000473:pathology; D004847:Epithelial Cells / Q000378:metabolism* / Q000473:pathology; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D007413:Intestinal Mucosa / Q000378:metabolism; D008297:Male; D008875:Middle Aged; D011379:Prognosis; D016760:Proto-Oncogene Proteins c-fos / Q000096:biosynthesis; D016755:Proto-Oncogene Proteins c-jun / Q000096:biosynthesis; D018808:Transcription Factor AP-1 / Q000096:biosynthesis*; D000099169:Fos-Related Antigen 1
chemical_list: D014408:Biomarkers, Tumor; D016760:Proto-Oncogene Proteins c-fos; D016755:Proto-Oncogene Proteins c-jun; D018808:Transcription Factor AP-1; D000099169:Fos-Related Antigen 1