title: G-protein coupled receptor-associated sorting protein 1 (GASP-1), a ubiquitous tumor marker.
abstract: Using an innovative "2-D high performance liquid electrophoresis" (2-D HPLE) technology we identified that a specific fragment of G-protein coupled receptor-associated sorting protein 1 (GASP-1) was present in the sera of breast cancer patients and was over-expressed in early and late stage breast tumors (Tuszynski, G.P. et al., 2011). In this study we further investigated the significance of GASP-1 as a tumor marker by investigating the expression GASP-1 in different kinds of tumors as well as in the sera of patients with various cancers. Over expression of GASP-1 was detected in brain, pancreatic, and breast cancers as compared to their respective normal tissues as assessed by immunohistochemical staining of tissue arrays using a "peptide specific" GASP-1 antibody. We found that across these cancers, GASP-1 was expressed approximately 10 fold more in the cancer as compared to normal tissue. The increase in GASP-1 expression was also seen in hyperplastic and inflammatory lesions of breast and pancreatic cancers as compared to normal tissue. GASP-1 was primarily expressed in the tumor epithelium of the epithelial-derived cancers and in the transformed glial cells of the brain tumors. Using a sensitive "competitive ELISA" for GASP-1, we found that sera from patients with brain, liver, breast and lung cancers expressed 4-7 fold more GASP-1 peptide than sera from normal healthy individuals. These studies identify GASP-1 as a potential new serum and tumor biomarker for several cancers and suggest that GASP-1 may be a novel target for development of cancer therapeutics.
authors.affiliation: Department of Biology, Temple University College of Science and Technology, PA, USA.
authors.forename: Xiaoyi
authors.initials: X
authors.lastname: Zheng
authors.forename: Frank
authors.initials: F
authors.lastname: Chang
authors.forename: Xinmin
authors.initials: X
authors.lastname: Zhang
authors.forename: Vicki L
authors.initials: VL
authors.lastname: Rothman
authors.forename: George P
authors.initials: GP
authors.lastname: Tuszynski
mesh_terms: D000912:Antibodies, Neoplasm / Q000276:immunology; D014408:Biomarkers, Tumor / Q000097:blood / Q000276:immunology / Q000378:metabolism*; D001932:Brain Neoplasms / Q000097:blood / Q000378:metabolism; D001943:Breast Neoplasms / Q000097:blood / Q000378:metabolism; D005260:Female; D005910:Glioma / Q000097:blood / Q000378:metabolism; D006801:Humans; D036341:Intercellular Signaling Peptides and Proteins; D008103:Liver Cirrhosis / Q000097:blood; D008175:Lung Neoplasms / Q000097:blood / Q000378:metabolism; D009369:Neoplasms / Q000097:blood / Q000378:metabolism*; D010190:Pancreatic Neoplasms / Q000737:chemistry / Q000378:metabolism; D011506:Proteins / Q000032:analysis / Q000276:immunology / Q000378:metabolism*
chemical_list: D000912:Antibodies, Neoplasm; D014408:Biomarkers, Tumor; D036341:Intercellular Signaling Peptides and Proteins; D011506:Proteins; C424444:WFIKKN2 protein, human