title: Lipoprotein lipase in non-small cell lung cancer tissue is highly expressed in a subpopulation of tumor-associated macrophages.
abstract: High lipoprotein lipase (LPL) activity in non-small cell lung cancer (NSCLC) tissue strongly predicts shorter patient survival. We tested the hypothesis that in NSCLC tissue, macrophages are the major site of LPL expression. LPL expression in the entire NSCLC tissue and in the adjacent non-cancer lung tissue was compared to the expression of genes preferentially expressed in macrophages. LPL expression at the cellular level was analyzed by mRNA fluorescence in situ hybridization. In the whole cancer tissue (but not in the adjacent non-cancer tissue), expression of LPL correlated with expression of genes preferentially expressed in macrophages (MSR1, CD163, FOLR2), but not with expression of genes preferentially expressed in tumor cells. All cells in the cancer and adjacent non-cancer tissue exhibit low LPL expression. However, in cancer tissue only, there were individual highly LPL-expressing cells which were macrophages. These LPL-overexpressing cells were approximately 10 times less abundant than anti-CD163-stained, tumor-associated macrophages. To conclude, in NSCLC tissue, a subpopulation of tumor-associated macrophages highly expresses LPL. Because tumor-associated macrophages are pro-tumorigenic, these cells should be further characterized to better understand the underlying nature of the close relationship between high LPL activity in NSCLC tissue and shorter patient survival.
authors.affiliation: Department of Haematology, University Medical Centre Ljubljana, Zaloska cesta 2, 1000 Ljubljana, Slovenia.
authors.forename: Helena
authors.initials: H
authors.lastname: Podgornik
authors.forename: Miha
authors.initials: M
authors.lastname: Sok
authors.forename: Izidor
authors.initials: I
authors.lastname: Kern
authors.forename: Janja
authors.initials: J
authors.lastname: Marc
authors.forename: Darko
authors.initials: D
authors.lastname: Cerne
mesh_terms: D000368:Aged; D015703:Antigens, CD / Q000032:analysis; D015214:Antigens, Differentiation, Myelomonocytic / Q000032:analysis; D014408:Biomarkers, Tumor / Q000032:analysis* / Q000235:genetics; D002289:Carcinoma, Non-Small-Cell Lung / Q000201:enzymology* / Q000276:immunology / Q000473:pathology; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D017404:In Situ Hybridization, Fluorescence; D018950:Lipopolysaccharide Receptors / Q000032:analysis; D008071:Lipoprotein Lipase / Q000032:analysis* / Q000235:genetics; D008175:Lung Neoplasms / Q000201:enzymology* / Q000276:immunology / Q000473:pathology; D008264:Macrophages / Q000201:enzymology* / Q000276:immunology; D008297:Male; D008875:Middle Aged; D012333:RNA, Messenger / Q000032:analysis; D060888:Real-Time Polymerase Chain Reaction; D011956:Receptors, Cell Surface / Q000032:analysis; D020133:Reverse Transcriptase Polymerase Chain Reaction; D015854:Up-Regulation; D000098902:CD163 Antigen
chemical_list: D015703:Antigens, CD; D015214:Antigens, Differentiation, Myelomonocytic; D014408:Biomarkers, Tumor; D000098902:CD163 Antigen; D018950:Lipopolysaccharide Receptors; D012333:RNA, Messenger; D011956:Receptors, Cell Surface; C548261:LPL protein, human; D008071:Lipoprotein Lipase
keywords: Gene expression; Lipoprotein lipase; Non-small cell lung cancer; Tumor associated macrophages