title: Evaluation of influence of Ap4A analogues on Fhit-positive HEK293T cells; cytotoxicity and ability to induce apoptosis.
abstract: Fragile histidine triad (Fhit) protein encoded by tumour suppressor FHIT gene is a proapoptotic protein with diadenosine polyphosphate (Ap(n)A, n=2-6) hydrolase activity. It has been hypothesised that formation of Fhit-substrate complex results in an apoptosis initiation signal while subsequent hydrolysis of Ap(n)A terminates this action. A series of Ap(n)A analogues have been identified in vitro as strong Fhit ligands [Varnum, J. M.; Baraniak, J.; Kaczmarek, R.; Stec, W. J.; Brenner, C. BMC Chem. Biol.2001, 1, 3]. We assumed that in Fhit-positive cells these compounds might preferentially bind to Fhit and inhibit its hydrolytic activity what would prolong the lifetime of apoptosis initiation signalling complex. Therefore, several Fhit inhibitors were tested for their cytotoxicity and ability to induce apoptosis in Fhit-positive HEK293T cells. These experiments have shown that Ap(4)A analogue, containing a glycerol residue instead of the central pyrophosphate and two terminal phosphorothioates [A(PS)-CH(2)CH(OH)CH(2)-(PS)A (1)], is the most cytotoxic among test compounds (IC(50)=17.5±4.2 μM) and triggers caspase-dependent cell apoptosis. The Fhit-negative HEK293T cells (in which Fhit was silenced by RNAi) were not sensitive to compound 1. These results indicate that the Ap(4)A analogue 1 induces Fhit-dependent apoptosis and therefore, it can be considered as a drug candidate for anticancer therapy in Fhit-positive cancer cells and in Fhit-negative cancer cells, in which re-expression of Fhit was accomplished by gene therapy.
authors.affiliation: Centre of Molecular and Macromolecular Studies, Polish Academy of Sciences, Department of Bioorganic Chemistry, Sienkiewicza 112, 90-363 Lodz, Poland. akrakow@cbmm.lodz.pl
authors.forename: Agnieszka
authors.initials: A
authors.lastname: Krakowiak
authors.forename: Róża
authors.initials: R
authors.lastname: Pęcherzewska
authors.forename: Renata
authors.initials: R
authors.lastname: Kaczmarek
authors.forename: Agnieszka
authors.initials: A
authors.lastname: Tomaszewska
authors.forename: Barbara
authors.initials: B
authors.lastname: Nawrot
authors.forename: Wojciech J
authors.initials: WJ
authors.lastname: Stec
mesh_terms: D017766:Acid Anhydride Hydrolases / Q000737:chemistry / Q000378:metabolism / Q000502:physiology*; D017304:Annexin A5 / Q000032:analysis; D000970:Antineoplastic Agents / Q000138:chemical synthesis* / Q000737:chemistry / Q000494:pharmacology / Q000627:therapeutic use; D017209:Apoptosis / Q000187:drug effects* / Q000235:genetics; D020169:Caspases / Q000032:analysis / Q000187:drug effects; D045744:Cell Line, Tumor; D002470:Cell Survival / Q000187:drug effects*; D003603:Cytotoxins; D015226:Dinucleoside Phosphates / Q000737:chemistry / Q000494:pharmacology* / Q000502:physiology / Q000627:therapeutic use; D004305:Dose-Response Relationship, Drug; D004354:Drug Screening Assays, Antitumor; D005260:Female; D005456:Fluorescent Dyes / Q000032:analysis; D016147:Genes, Tumor Suppressor / Q000187:drug effects; D057809:HEK293 Cells; D006801:Humans; D009363:Neoplasm Proteins / Q000502:physiology*; D009369:Neoplasms / Q000188:drug therapy* / Q000235:genetics / Q000378:metabolism / Q000473:pathology; D034741:RNA, Small Interfering / Q000378:metabolism; D000099170:Bis(5'-adenosyl)triphosphatase
chemical_list: D017766:Acid Anhydride Hydrolases; D017304:Annexin A5; D000970:Antineoplastic Agents; D020169:Caspases; D003603:Cytotoxins; D015226:Dinucleoside Phosphates; D005456:Fluorescent Dyes; D009363:Neoplasm Proteins; D034741:RNA, Small Interfering; D000099170:Bis(5'-adenosyl)triphosphatase; C020733:diadenosine tetraphosphate; C075829:diadenosine polyphosphate hydrolase