title: YKL-40 expression in human hepatocellular carcinoma: a potential biomarker?
abstract: BACKGROUND
  YKL-40 is a new biomarker with diagnostic value in many different cancers. Whether it may serve as a biomarker for hepatocellular carcinoma (HCC) is still unclear. This study aimed to examine the expression of YKL-40 in the serum and liver tissues of HCC patients and in HCC cell lines, in comparison with that in non-HCC liver disease patients and non-tumor hepatic cell lines, respectively.
  
  
  METHODS
  Immunohistochemical staining was used to detect YKL-40 protein expression in liver biopsy specimens from 8 HCC patients. ELISA was used to assess the serum YKL-40 level in 90 HCC patients, 90 inactive HBsAg carrier (IHC) patients with normal liver functions, and 90 liver cirrhosis patients. Real-time PCR was used to determine the YKL-40 mRNA expression in three HCC cell lines and two non-tumor hepatic cell lines.
  
  
  RESULTS
  Immunohistochemical staining of liver biopsy specimens from HCC patients showed that the YKL-40 protein expression in tumor tissue was higher than that in adjacent normal tissues. ELISA revealed that the YKL-40 serum level in the HCC group was significantly higher than that in the IHC group, but not significantly different from that in the cirrhosis group. Real-time PCR showed that YKL-40 mRNA levels in HCC cell lines were significantly higher than those in non-tumor hepatic cells.
  
  
  CONCLUSIONS
  YKL-40 is highly expressed in HCC at the molecular, cellular and tissue levels. However, it may not serve as a serum biomarker for HCC because measurement of the serum YKL-40 level cannot distinguish HCC from cirrhosis.
authors.affiliation: Liver Diseases Center, Second Xiangya Hospital, Central South University, Changsha 410011, China.
authors.forename: Xin-Qiang
authors.initials: XQ
authors.lastname: Xiao
authors.forename: Tarek
authors.initials: T
authors.lastname: Hassanein
authors.forename: Qun-Fang
authors.initials: QF
authors.lastname: Li
authors.forename: Wei
authors.initials: W
authors.lastname: Liu
authors.forename: Yu-Huang
authors.initials: YH
authors.lastname: Zheng
authors.forename: Jun
authors.initials: J
authors.lastname: Chen
mesh_terms: D054392:Adipokines / Q000096:biosynthesis / Q000235:genetics*; D000293:Adolescent; D000328:Adult; D000368:Aged; D014408:Biomarkers, Tumor / Q000096:biosynthesis / Q000235:genetics; D001706:Biopsy; D006528:Carcinoma, Hepatocellular / Q000235:genetics* / Q000378:metabolism / Q000473:pathology; D000071451:Chitinase-3-Like Protein 1; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D005500:Follow-Up Studies; D015972:Gene Expression Regulation, Neoplastic; D006023:Glycoproteins; D006801:Humans; D007150:Immunohistochemistry; D037102:Lectins / Q000096:biosynthesis / Q000235:genetics*; D008113:Liver Neoplasms / Q000235:genetics* / Q000378:metabolism / Q000473:pathology; D008297:Male; D008875:Middle Aged; D011379:Prognosis; D012334:RNA, Neoplasm / Q000235:genetics*; D060888:Real-Time Polymerase Chain Reaction; D012189:Retrospective Studies; D014407:Tumor Cells, Cultured; D055815:Young Adult
chemical_list: D054392:Adipokines; D014408:Biomarkers, Tumor; C084533:CHI3L1 protein, human; D000071451:Chitinase-3-Like Protein 1; D006023:Glycoproteins; D037102:Lectins; D012334:RNA, Neoplasm