title: YKL-40 expression in benign and malignant lesions of the breast: a methodologic study.
abstract: Elevated serum levels of the protein YKL-40 are associated with a poor prognosis in patients with solid and hematologic malignancies including breast cancer. The aim of this study was to develop a valid reproducible immunohistochemical method to visualize YKL-40 expression in normal breast tissue as well as in benign and malignant breast lesions. The presence of YKL-40 in breast tissue was verified by in situ hybridization and protein extraction procedures. An immunohistochemical method was developed and 4 different antibodies directed against YKL-40 were tested. Ten patients with normal breast tissue and benign breast lesions and 53 patients with localized breast carcinomas were analyzed immunohistochemically. The presence of YKL-40 in normal epithelial cells as well as in malignant tumor cells of the breast was established; however, a difference in staining intensity and staining pattern was observed. In normal breast tissue, a weak YKL-40 immunoreactivity was found in the cytoplasm of the epithelial cells with an additional strong dotlike staining between the nucleus and the gland lumen. In malignant lesions, 81% of the in situ carcinomas and 64% of the invasive carcinomas showed strong diffuse cytoplasmic YKL-40 immunoreactivity. No nuclear and membrane staining was found. A subpopulation of cells of macrophage morphology in normal breast tissue and in malignant lesions showed strong YKL-40 immunoreactivity.
authors: Department of Oncology, Herlev University Hospital, Herlev Ringvej 75, DK-2730 Copenhagen, Denmark. anne.roslind@dadlnet.dk
authors: Anne
authors: A
authors: Roslind
authors: Julia S
authors: JS
authors: Johansen
authors: Nanna
authors: N
authors: Junker
authors: Dorte L
authors: DL
authors: Nielsen
authors: Hanife
authors: H
authors: Dzaferi
authors: Paul A
authors: PA
authors: Price
authors: Eva
authors: E
authors: Balslev
mesh_terms: D054392:Adipokines; D000328:Adult; D000368:Aged; D001940:Breast / Q000737:chemistry* / Q000378:metabolism* / Q000473:pathology*; D001943:Breast Neoplasms / Q000737:chemistry / Q000378:metabolism / Q000473:pathology*; D002277:Carcinoma / Q000737:chemistry / Q000378:metabolism / Q000473:pathology*; D000071451:Chitinase-3-Like Protein 1; D005260:Female; D005557:Formaldehyde / Q000737:chemistry; D006023:Glycoproteins / Q000032:analysis* / Q000235:genetics / Q000378:metabolism; D006801:Humans; D007150:Immunohistochemistry / Q000379:methods*; D017403:In Situ Hybridization; D037102:Lectins; D008875:Middle Aged; D012333:RNA, Messenger / Q000032:analysis / Q000378:metabolism; D012710:Serum Albumin, Bovine / Q000737:chemistry
chemical_list: D054392:Adipokines; C084533:CHI3L1 protein, human; D000071451:Chitinase-3-Like Protein 1; D006023:Glycoproteins; D037102:Lectins; D012333:RNA, Messenger; D005557:Formaldehyde; D012710:Serum Albumin, Bovine