title: Development of an ELISA for quantification of tumstatin in serum samples and tissue extracts of patients with lung carcinoma.
abstract: BACKGROUND
  Tumstatin, an angiogenesis inhibitor with anti-tumor activity in mice, is the bioactive NC1 domain of Col IVa3, the potential significance of tumstatin as an endogenous angiogenesis inhibitor in human is not yet completely understood. This study aimed to develop an enzyme-linked immunoassay (ELISA) for tumstatin to accurately measure its concentrations in biological samples.
  
  
  METHODS
  Recombinant tumstatin as an immunogen was expressed by E.coli. The purified tumstatin was injected into mice for antibody generation. An ELISA was developed with the monoclonal antibodies.
  
  
  RESULTS
  The detection limit of the ELISA was 1.4ng/ml, and the intra- and inter- assay CVs were within 10%. Recovery of tumstatin added to sera was 92.7-115%. Patients with metastases had serum tumstatin levels 50% lower than patients without metastases (P=0.039). Tumstatin levels in poorly differentiated tumor tissues were significantly lower than in nontumorous tissues and well-differentiated tumor tissues (P<0.001).
  
  
  CONCLUSIONS
  The development of a highly sensitive and reliable ELISA method capable of quantifying tumstatin in human serum samples and tissue extracts is reported. This assay for tumstatin in biological samples may be helpful in evaluating the therapeutic and/or prognostic value of tumstatin in cancer patients.
authors.affiliation: Department of Laboratory Medicine, The Affiliated Anhui Provincial Hospital of Anhui Medical University, Hefei, People's Republic of China. luoyiqin2004@hotmail.com
authors.forename: Yi-Qin
authors.initials: YQ
authors.lastname: Luo
authors.lastname: Li-JuanYao
authors.forename: Liang
authors.initials: L
authors.lastname: Zhao
authors.forename: An-yuan
authors.initials: AY
authors.lastname: Sun
authors.forename: Hang
authors.initials: H
authors.lastname: Dong
authors.forename: Jian-Ping
authors.initials: JP
authors.lastname: Du
authors.forename: Shuang-Zheng
authors.initials: SZ
authors.lastname: Wu
authors.forename: Wen
authors.initials: W
authors.lastname: Hu
mesh_terms: D000328:Adult; D000368:Aged; D000818:Animals; D001324:Autoantigens / Q000032:analysis* / Q000097:blood* / Q000302:isolation & purification; D016466:CHO Cells; D024141:Collagen Type IV / Q000032:analysis* / Q000097:blood* / Q000302:isolation & purification; D006224:Cricetinae; D003412:Cricetulus; D004797:Enzyme-Linked Immunosorbent Assay / Q000379:methods*; D005260:Female; D006801:Humans; D008175:Lung Neoplasms / Q000097:blood* / Q000175:diagnosis / Q000378:metabolism*; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C; D008875:Middle Aged; D011994:Recombinant Proteins / Q000097:blood / Q000302:isolation & purification
chemical_list: D001324:Autoantigens; D024141:Collagen Type IV; D011994:Recombinant Proteins; C057112:type IV collagen alpha3 chain