title: False and mycoplasma-contaminated leukemia-lymphoma cell lines: time for a reappraisal.
abstract: Leukemia-lymphoma cell lines are important research tools in a variety of fields. To represent adequate model systems it is of utmost importance that cell lines faithfully model the primary tumor material and are not cross-contaminated with unrelated cell material (or contaminated with mycoplasma). As it has been previously reported that cross-contaminated cell lines represent a significant problem, it is of interest to know whether any improvement in the prevalence of such "false cell lines" had occurred since we called the alert in 1999. A retrospective review of our data archives covered 848 cell lines received from 1990 to 2014 from 290 laboratories in 23 countries spanning the spectrum of leukemia-lymphoma entities. Two variables were considered: authenticity and freedom from mycoplasma infection. Regarding provenance, we separately considered primary sources (original investigators having established the cell lines or reference repositories) and secondary sources. The percentages of mycoplasma-contaminated cell lines decreased significantly over the 25-year timespan. Among primary sourced material: mycoplasma-contamination fell from 23% to 0%; among secondary sourced: from 48% to 21%. The corresponding figures for cross-contamination declined from 15% to 6%, while among material obtained from secondary sources prevalence remained remarkably high, throughout the time periods at 14-18%. Taken together, our data indicate that using non-authenticated cell lines from secondary sources carries a risk of about 1:6 for obtaining a false cell line. The use of authentic leukemia-lymphoma cell lines holds important translational value for their model character and the reproducibility of the laboratory data in the clinical arena.
authors.affiliation: Department of Human and Animal Cell Lines, Leibniz-Institute DSMZ-German Collection of Microorganisms and Cell Cultures, Braunschweig, Germany.
authors.forename: Hans G
authors.initials: HG
authors.lastname: Drexler
authors.affiliation: Department of Human and Animal Cell Lines, Leibniz-Institute DSMZ-German Collection of Microorganisms and Cell Cultures, Braunschweig, Germany.
authors.forename: Wilhelm G
authors.initials: WG
authors.lastname: Dirks
authors.affiliation: Department of Human and Animal Cell Lines, Leibniz-Institute DSMZ-German Collection of Microorganisms and Cell Cultures, Braunschweig, Germany.
authors.forename: Roderick A F
authors.initials: RA
authors.lastname: MacLeod
authors.affiliation: Department of Human and Animal Cell Lines, Leibniz-Institute DSMZ-German Collection of Microorganisms and Cell Cultures, Braunschweig, Germany.
authors.forename: Cord C
authors.initials: CC
authors.lastname: Uphoff
mesh_terms: D045744:Cell Line, Tumor / Q000382:microbiology*; D016172:DNA Fingerprinting; D006801:Humans; D017403:In Situ Hybridization; D007621:Karyotyping; D007938:Leukemia / Q000473:pathology*; D008223:Lymphoma / Q000473:pathology*; D009174:Mycoplasma / Q000302:isolation & purification*; D012189:Retrospective Studies
keywords: authentification; cell lines; leukemia; lymphoma; mycoplasma