title: Immunohistochemical analysis of RNA-induced silencing complex-related proteins AGO2 and TNRC6A in prostate and esophageal cancers.
abstract: Evidence exists that microRNA (miRNA), which regulates gene expression, is frequently deregulated in cancers. A mature miRNA directs a RNA-induced silencing complex (RISC) to its target messenger RNA, and causes inhibition of gene transcription. Ago proteins and TNRC proteins are main components of the RISC and participate in miRNA-induced gene silencing. However, expression status of Ago and TNRC proteins has not yet been studied in human cancer tissues. In this study, we attempted to explore whether expressions of Ago2 and TNRC6A are altered in prostate carcinomas (PCA) and esophageal squamous cell carcinomas (ESCC). We analyzed the expression of Ago2 and TNRC6A in 107 PCA and 58 ESCC tissues by immunohistochemistry using a tissue microarray (TMA) method. In the prostate, Ago2 was not expressed in normal glandular cells, while it was expressed in 50.0% of prostate intraepithelial neoplasia (PIN) and 57.0% of the PCA. TNRC6A was not expressed in normal prostate cells, while it was expressed in 55.0% of the PIN and 63.6% of the PCA in cytoplasm and nucleus. In the esophagus, neither Ago2 nor TNRC6A was expressed in normal squamous cells, while Ago2 and TNRC6A were expressed in 58.6% and 62.1% of the ESCC, respectively. However, neither the expression of Ago2 or TNRC6A was associated with pathologic characteristics of the cancers, including age, sex, Gleason score (PCA) and stage. The increased expressions of Ago2 and TNRC6A in both PCA and ESCC compared with their normal cells suggested that over-expression of these proteins may be related to miRNA functions and might play a role in tumorigenesis of PCA and ESCC.
authors.affiliation: Department of Pathology, College of Medicine, The Catholic University of Korea, Seoul, Korea.
authors.forename: Nam Jin
authors.initials: NJ
authors.lastname: Yoo
authors.forename: Soo Young
authors.initials: SY
authors.lastname: Hur
authors.forename: Min Sung
authors.initials: MS
authors.lastname: Kim
authors.forename: Ji Youl
authors.initials: JY
authors.lastname: Lee
authors.forename: Sug Hyung
authors.initials: SH
authors.lastname: Lee
mesh_terms: D000328:Adult; D000368:Aged; D060565:Argonaute Proteins; D001324:Autoantigens / Q000096:biosynthesis*; D002294:Carcinoma, Squamous Cell / Q000235:genetics / Q000378:metabolism* / Q000473:pathology; D004938:Esophageal Neoplasms / Q000235:genetics / Q000378:metabolism* / Q000473:pathology; D015852:Eukaryotic Initiation Factor-2 / Q000096:biosynthesis*; D015870:Gene Expression; D020868:Gene Silencing; D006801:Humans; D007150:Immunohistochemistry; D008297:Male; D008875:Middle Aged; D011471:Prostatic Neoplasms / Q000235:genetics / Q000378:metabolism* / Q000473:pathology; D016601:RNA-Binding Proteins; D034743:RNA-Induced Silencing Complex / Q000378:metabolism; D046888:Tissue Array Analysis
chemical_list: C466422:AGO2 protein, human; D060565:Argonaute Proteins; D001324:Autoantigens; D015852:Eukaryotic Initiation Factor-2; D016601:RNA-Binding Proteins; D034743:RNA-Induced Silencing Complex; C465663:TNRC6A protein, human