title: Elevated proinflammatory cytokine IL-17A in the adjacent tissues along the adenoma-carcinoma sequence.
abstract: Considerable evidence has suggested that chronic inflammation is a causative factor in the development of human colorectal cancer (CRC). Interleukin (IL)-17A produced mainly by Th17 cells is a novel proinflammatory cytokine and increased IL-17A is associated with colorectal neoplastic transformation. In this study, we have evaluated the expression of IL-17A in the adjacent tissues along the colorectal adenoma-carcinoma sequence. The expression of IL-17A in the adjacent tissues of colorectal adenoma (adenoma-adjacent, n = 32) and sporadic CRC (CRC-adjacent, n = 45) was examined. In addition, the expression pattern of Th17 cell differentiation stimulators (IL-1β, IL-6 and IL-23A) in the adjacent tissues were also examined. The results showed that the expression level of IL-17A mRNA was non-statistically increased (4-fold higher) in the adenoma-adjacent tissues and it became significantly increased (9-fold higher) in the CRC-adjacent tissues as compared with the control. The expression level of IL-17A in the CRC-adjacent tissues was not associated with CRC clinicopathological parameters and overall survival. Immunohistochemistry confirmed an increased density of intraepithelial IL-17A expressing cells in the CRC-adjacent tissues. The Th17 cell differentiation simulators IL-1β and IL-6 were also shown in an increase trend from the adenoma-adjacent to CRC-adjacent tissues. These results provide evidence that IL-17A/Th17 response is enhanced in the adjacent tissues during the colorectal neoplastic transformation.
authors.affiliation: Department of Gastroenterology, The Second Affiliated Hospital of Zhengzhou University, Zhengzhou, Henan, China, guanglin.cui@hint.no.
authors.forename: Guanglin
authors.initials: G
authors.lastname: Cui
authors.forename: Hang
authors.initials: H
authors.lastname: Yang
authors.forename: Jianbo
authors.initials: J
authors.lastname: Zhao
authors.forename: Aping
authors.initials: A
authors.lastname: Yuan
authors.forename: Jon
authors.initials: J
authors.lastname: Florholmen
mesh_terms: D000236:Adenoma / Q000235:genetics / Q000378:metabolism*; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002277:Carcinoma / Q000235:genetics / Q000378:metabolism*; D002454:Cell Differentiation / Q000235:genetics; D002471:Cell Transformation, Neoplastic / Q000235:genetics; D005260:Female; D006801:Humans; D007150:Immunohistochemistry / Q000379:methods; D007249:Inflammation / Q000235:genetics / Q000378:metabolism*; D020381:Interleukin-17 / Q000235:genetics / Q000378:metabolism*; D053583:Interleukin-1beta / Q000235:genetics / Q000378:metabolism; D015850:Interleukin-6 / Q000235:genetics / Q000378:metabolism; D008297:Male; D008875:Middle Aged; D012333:RNA, Messenger / Q000235:genetics; D058504:Th17 Cells / Q000378:metabolism
chemical_list: C508717:IL17A protein, human; D020381:Interleukin-17; D053583:Interleukin-1beta; D015850:Interleukin-6; D012333:RNA, Messenger