title: TKTL1 expression in human malign and benign cell lines.
abstract: BACKGROUND
  Overexpression of transketolase-like 1 protein TKTL1 in cancer cells has been reported to correlate with enhanced glycolysis and lactic acid production. Furthermore, enhanced TKTL1 expression was put into context with resistance to chemotherapy and ionizing radiation. Here, a panel of human malign and benign cells, which cover a broad range of chemotherapy and radiation resistance as well as reliance on glucose metabolism, was analyzed in vitro for TKTL1 expression.
  
  
  METHODS
  17 malign and three benign cell lines were characterized according to their expression of TKTL1 on the protein level with three commercially available anti-TKTL1 antibodies utilizing immunohistochemistry and Western blot, as well as on mRNA level with three published primer pairs for RT-qPCR. Furthermore, sensitivities to paclitaxel, cisplatin and ionizing radiation were assessed in cell survival assays. Glucose consumption and lactate production were quantified as surrogates for the "Warburg effect".
  
  
  RESULTS
  Considerable amounts of tktl1 mRNA and TKTL1 protein were detected only upon stable transfection of the human embryonic kidney cell line HEK293 with an expression plasmid for human TKTL1. Beyond that, weak expression of endogenous tktl1 mRNA was measured in the cell lines JAR and U251. Western blot analysis of JAR and U251 cells did not detect TKTL1 at the expected size of 65 kDa with all three antibodies specific for TKTL1 protein and immunohistochemical staining was observed with antibody JFC12T10 only. All other cell lines tested here revealed expression of tktl1 mRNA below detection limits and were negative for TKTL1 protein. However, in all cell lines including TKTL1-negative HEK293-control cells, antibody JFC12T10 detected multiple proteins with different molecular weights. Importantly, JAR and U251 did neither demonstrate an outstanding production of lactic acid nor increased resistance against chemotherapeutics or to ionizing radiation, respectively.
  
  
  CONCLUSIONS
  Using RT-qPCR and three different antibodies we observed only exceptional occurrence of TKTL1 in a panel of malignant human cell lines in vitro. The presence of TKTL1 was unrelated to either the rate of glucose consumption/lactic acid production or resistance against chemo- and radiotherapy.
authors.affiliation: Department of Obstetrics and Gynaecology, University of Würzburg Hospital, Josef-Schneider-Str. 4, D-97080, Würzburg, Germany. frak057@mail.uni-wuerzburg.de.
authors.forename: Ulrike
authors.initials: U
authors.lastname: Kämmerer
authors.affiliation: Department of Otorhinolaryngology, Head and Neck Surgery, Ludwig-Maximilians-University, Marchioninistr. 15, D-81377, Munich, Germany. Olivier.gires@med.uni-muenchen.de.
authors.forename: Olivier
authors.initials: O
authors.lastname: Gires
authors.affiliation: Department of Obstetrics and Gynaecology, University of Würzburg Hospital, Josef-Schneider-Str. 4, D-97080, Würzburg, Germany. N.Pfetzer@beatson.gla.ac.uk.|Apoptosis and Tumour Metabolism Lab, CRUK Beatson Institute, Garscube Estate, Switchback Road, Glasgow, G61 1BD, United Kingdom. N.Pfetzer@beatson.gla.ac.uk.
authors.forename: Nadja
authors.initials: N
authors.lastname: Pfetzer
authors.affiliation: Department of General, Visceral, Vascular and Paediatric Surgery, University Hospital of Würzburg, Oberdürrbacher Str. 6, D-97080, Würzburg, Germany. Wiegering_A@ukw.de.
authors.forename: Armin
authors.initials: A
authors.lastname: Wiegering
authors.affiliation: Department of Radiotherapy and Radiation Oncology, Leopoldina Hospital Schweinfurt, Gustav-Adolf-Straße 8, D-97422, Schweinfurt, Germany. rainer_klement@gmx.de.
authors.forename: Rainer Johannes
authors.initials: RJ
authors.lastname: Klement
authors.affiliation: Experimental Surgery, Experimental Transplantation Immunology, Department of General, Visceral, Vascular and Paediatric Surgery, University Hospital of Würzburg, Oberdürrbacher Str. 6, D-97080, Würzburg, Germany. Otto_c@ukw.de.
authors.forename: Christoph
authors.initials: C
authors.lastname: Otto
mesh_terms: D000970:Antineoplastic Agents / Q000494:pharmacology*; D002460:Cell Line; D002470:Cell Survival / Q000187:drug effects / Q000528:radiation effects; D002945:Cisplatin / Q000494:pharmacology; D019008:Drug Resistance, Neoplasm; D015972:Gene Expression Regulation, Neoplastic; D005947:Glucose / Q000378:metabolism*; D045325:HCT116 Cells; D057809:HEK293 Cells; D006367:HeLa Cells; D061307:Human Umbilical Vein Endothelial Cells; D006801:Humans; D019344:Lactic Acid / Q000378:metabolism*; D061986:MCF-7 Cells; D017239:Paclitaxel / Q000494:pharmacology; D011836:Radiation Tolerance; D014174:Transketolase / Q000235:genetics* / Q000378:metabolism*
chemical_list: D000970:Antineoplastic Agents; D019344:Lactic Acid; C505431:TKTL1 protein, human; D014174:Transketolase; D005947:Glucose; D017239:Paclitaxel; D002945:Cisplatin