title: Determining ProGRP and isoforms in lung and thyroid cancer patient samples: comparing an MS method with a routine clinical immunoassay.
abstract: This paper compares two methods to determine the tumor marker progastrin-releasing peptide (ProGRP): as routine assay, the automated time-resolved immunofluorometric assay (TR-IFMA), which allows total ProGRP determination; and the immunocapture liquid chromatography selected reaction monitoring mass spectrometry (LC-SRM-MS) method, which additionally allows isoform differentiation. The investigation included 60 serum samples from patients suffering from various cancer diseases which may cause elevated ProGRP levels (small cell lung carcinoma; SCLC, non-small cell lung carcinoma; NCLC; and medullary thyroid cancer; MTC, as well as some with unspecific diagnosis). The two methods showed good correlation (R (2) = 0.887). However, the MS method determines the total ProGRP concentration systematically approximately 30 % lower than the TR-IFMA, implying that the absolute values generated by the methods are not interchangeable. The MS method gives additional information about isoform levels in the samples, providing novel insight into isoform expression on the protein level.
authors: Department of Pharmaceutical Chemistry, School of Pharmacy, University of Oslo, P.O. Box 1068, Blindern, 0316, Oslo, Norway.
authors: Silje Bøen
authors: SB
authors: Torsetnes
authors: Marianne Nordlund
authors: MN
authors: Broughton
authors: Elisabeth
authors: E
authors: Paus
authors: Trine Grønhaug
authors: TG
authors: Halvorsen
authors: Léon
authors: L
authors: Reubsaet
mesh_terms: D014408:Biomarkers, Tumor / Q000097:blood; D006801:Humans; D007118:Immunoassay / Q000379:methods*; D008175:Lung Neoplasms / Q000097:blood* / Q000175:diagnosis; D013058:Mass Spectrometry / Q000379:methods*; D010446:Peptide Fragments / Q000097:blood*; D011994:Recombinant Proteins / Q000097:blood; D013964:Thyroid Neoplasms / Q000097:blood* / Q000175:diagnosis
chemical_list: D014408:Biomarkers, Tumor; D010446:Peptide Fragments; D011994:Recombinant Proteins; C087079:pro-gastrin-releasing peptide (31-98)