title: Hypoxic resistance of KRAS mutant tumor cells to 3-Bromopyruvate is counteracted by Prima-1 and reversed by N-acetylcysteine.
abstract: The metabolic inhibitor 3-bromopyruvate (3-BrPA) is a promising anti-cancer alkylating agent, shown to inhibit growth of some colorectal carcinoma with KRAS mutation. Recently, we demonstrated increased resistance to 3-BrPA in wt p53 tumor cells compared to those with p53 silencing or mutation. Since hypoxic microenvironments select for tumor cells with diminished therapeutic response, we investigated whether hypoxia unequally increases resistance to 3-BrPA in wt p53 MelJuso melanoma harbouring (Q61L)-mutant NRAS and wt BRAF, C8161 melanoma with (G12D)-mutant KRAS (G464E)-mutant BRAF, and A549 lung carcinoma with a KRAS (G12S)-mutation. Since hypoxia increases the toxicity of the p53 activator, Prima-1 against breast cancer cells irrespective of their p53 status, we also investigated whether Prima-1 reversed hypoxic resistance to 3-BrPA.
  
  
  
  In contrast to the high susceptibility of hypoxic mutant NRAS MelJuso cells to 3-BrPA or Prima-1, KRAS mutant C8161 and A549 cells revealed hypoxic resistance to 3-BrPA counteracted by Prima-1. In A549 cells, Prima-1 increased p21CDKN1mRNA, and reciprocally inhibited mRNA expression of the SLC2A1-GLUT1 glucose transporter-1 and ALDH1A1, gene linked to detoxification and stem cell properties. 3-BrPA lowered CAIX and VEGF mRNA expression. Death from joint Prima-1 and 3-BrPA treatment in KRAS mutant A549 and C8161 cells seemed mediated by potentiating oxidative stress, since it was antagonized by the anti-oxidant and glutathione precursor N-acetylcysteine.
  
  
  
  This report is the first to show that Prima-1 kills hypoxic wt p53 KRAS-mutant cells resistant to 3-BrPA, partly by decreasing GLUT-1 expression and exacerbating pro-oxidant stress.
authors.affiliation: IVIC, Tumor Cell Biology Laboratory, Apartado 21827, Caracas, 1020A, Venezuela.
authors.forename: Andrea
authors.initials: A
authors.lastname: Orue
authors.affiliation: IVIC, Tumor Cell Biology Laboratory, Apartado 21827, Caracas, 1020A, Venezuela.
authors.forename: Valery
authors.initials: V
authors.lastname: Chavez
authors.affiliation: IVIC, Tumor Cell Biology Laboratory, Apartado 21827, Caracas, 1020A, Venezuela.
authors.forename: Mary
authors.initials: M
authors.lastname: Strasberg-Rieber
authors.affiliation: IVIC, Tumor Cell Biology Laboratory, Apartado 21827, Caracas, 1020A, Venezuela. manuel.rieber@gmail.com.
authors.forename: Manuel
authors.initials: M
authors.lastname: Rieber
mesh_terms: D000072283:A549 Cells; D000111:Acetylcysteine / Q000494:pharmacology*; D001372:Aza Compounds / Q000494:pharmacology*; D019086:Bridged Bicyclo Compounds, Heterocyclic / Q000494:pharmacology*; D015687:Cell Hypoxia; D045744:Cell Line, Tumor; D002470:Cell Survival / Q000187:drug effects / Q000235:genetics; D050759:Cyclin-Dependent Kinase Inhibitor p21 / Q000235:genetics; D019008:Drug Resistance, Neoplasm / Q000187:drug effects* / Q000235:genetics; D016166:Free Radical Scavengers / Q000494:pharmacology; D020558:GTP Phosphohydrolases / Q000235:genetics; D015972:Gene Expression Regulation, Neoplastic / Q000187:drug effects; D051272:Glucose Transporter Type 1 / Q000235:genetics; D006801:Humans; D008175:Lung Neoplasms / Q000235:genetics / Q000473:pathology; D008545:Melanoma / Q000235:genetics / Q000473:pathology; D008565:Membrane Proteins / Q000235:genetics; D009154:Mutation; D016283:Proto-Oncogene Proteins p21(ras) / Q000235:genetics*; D011773:Pyruvates / Q000494:pharmacology*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D016159:Tumor Suppressor Protein p53 / Q000235:genetics
chemical_list: D001372:Aza Compounds; D019086:Bridged Bicyclo Compounds, Heterocyclic; C493956:CDKN1A protein, human; D050759:Cyclin-Dependent Kinase Inhibitor p21; D016166:Free Radical Scavengers; D051272:Glucose Transporter Type 1; C117307:KRAS protein, human; D008565:Membrane Proteins; D011773:Pyruvates; D016159:Tumor Suppressor Protein p53; C017092:bromopyruvate; D020558:GTP Phosphohydrolases; C579846:NRAS protein, human; D016283:Proto-Oncogene Proteins p21(ras); C451219:2,2-bis(hydroxymethyl)-1-azabicyclo(2,2,2,)octan-3-one; D000111:Acetylcysteine
keywords: ALDH1A1; GLUT1; Hypoxia; KRAS mutation; p53 reactivation