title: Telomerase activated thymidine analogue pro-drug is a new molecule targeting hepatocellular carcinoma.
abstract: OBJECTIVE
  Hepatocellular carcinoma (HCC) is one of the most common malignancies worldwide. Although hepatectomy and transplantation have significantly improved survival, there is no effective chemotherapeutic treatment for HCC and its prognosis remains poor. Sustained activation of telomerase is essential for the growth and progression of HCC, suggesting that telomerase is a rational target for HCC therapy. Therefore, we developed a thymidine analogue pro-drug, acycloguanosyl-5'-thymidyltriphosphate (ACV-TP-T), which is specifically activated by telomerase in HCC cells and investigated its anti-tumour efficacy.
  
  
  METHODS
  First, we verified in vitro whether ACV-TP-T was a telomerase substrate. Second, we evaluated proliferation and apoptosis in murine (Hepa1-6) and human (Hep3B, HuH7, HepG2) hepatic cancer cells treated with ACV-TP-T. Next, we tested the in vivo treatment efficacy in HBV transgenic mice that spontaneously develop hepatic tumours, and in a syngeneic orthotopic murine model where HCC cells were implanted directly in the liver.
  
  
  RESULTS
  In vitro characterization provided direct evidence that the pro-drug was actively metabolized in liver cancer cells by telomerase to release the active form of acyclovir. Alterations in cell cycle and apoptosis were observed following in vitro treatment with ACV-TP-T. In the transgenic and orthotopic mouse models, treatment with ACV-TP-T reduced tumour growth, increased apoptosis, and reduced the proliferation of tumour cells.
  
  
  CONCLUSIONS
  ACV-TP-T is activated by telomerase in HCC cells and releases active acyclovir that reduces proliferation and induces apoptosis in human and murine liver cancer cells. This pro-drug holds a great promise for the treatment of HCC.
authors.affiliation: Department of Experimental and Clinical Biomedical Sciences, University of Florence, Florence, Italy.
authors.forename: Mirko
authors.initials: M
authors.lastname: Tarocchi
authors.affiliation: Department of Experimental and Clinical Biomedical Sciences, University of Florence, Florence, Italy.
authors.forename: Simone
authors.initials: S
authors.lastname: Polvani
authors.affiliation: Department of Experimental and Clinical Biomedical Sciences, University of Florence, Florence, Italy.
authors.forename: Anna Julie
authors.initials: AJ
authors.lastname: Peired
authors.affiliation: Department of Experimental and Clinical Biomedical Sciences, University of Florence, Florence, Italy.
authors.forename: Giada
authors.initials: G
authors.lastname: Marroncini
authors.affiliation: ProtEra S.r.l., University Scientific Campus, Sesto Fiorentino, Florence, Italy; ICCOM-CNR Florence, Italy.
authors.forename: Massimo
authors.initials: M
authors.lastname: Calamante
authors.affiliation: Department of Experimental and Clinical Biomedical Sciences, University of Florence, Florence, Italy.
authors.forename: Elisabetta
authors.initials: E
authors.lastname: Ceni
authors.affiliation: MRC Laboratory of Molecular Biology, Cambridge, UK.
authors.forename: Daniela
authors.initials: D
authors.lastname: Rhodes
authors.affiliation: Department of Experimental and Clinical Biomedical Sciences, University of Florence, Florence, Italy.
authors.forename: Tommaso
authors.initials: T
authors.lastname: Mello
authors.affiliation: Mass Spectrometry Centre (CISM), University of Florence, Florence, Italy.
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Pieraccini
authors.affiliation: Magnetic Resonance Center (CERM), University of Florence, Sesto Fiorentino, Florence, Italy; Laboratory of Translational Genomics, Centre for Integrative Biology, University of Trento, Italy.
authors.forename: Alessandro
authors.initials: A
authors.lastname: Quattrone
authors.affiliation: Magnetic Resonance Center (CERM), University of Florence, Sesto Fiorentino, Florence, Italy; Department of Chemistry, University of Florence, Sesto Fiorentino, Florence, Italy; Giotto Biotech S.r.l., University Scientific Campus, Sesto Fiorentino, Florence, Italy.
authors.forename: Claudio
authors.initials: C
authors.lastname: Luchinat
authors.affiliation: Department of Experimental and Clinical Biomedical Sciences, University of Florence, Florence, Italy. Electronic address: andrea.galli@unifi.it.
authors.forename: Andrea
authors.initials: A
authors.lastname: Galli
mesh_terms: D000212:Acyclovir / Q000378:metabolism / Q000627:therapeutic use; D000818:Animals; D000970:Antineoplastic Agents / Q000378:metabolism / Q000627:therapeutic use*; D017209:Apoptosis / Q000187:drug effects; D006528:Carcinoma, Hepatocellular / Q000188:drug therapy* / Q000378:metabolism / Q000473:pathology; D045744:Cell Line, Tumor; D006151:Guanosine / Q000031:analogs & derivatives* / Q000378:metabolism / Q000627:therapeutic use; D056945:Hep G2 Cells; D006515:Hepatitis B virus / Q000235:genetics / Q000472:pathogenicity; D006801:Humans; D008113:Liver Neoplasms / Q000188:drug therapy* / Q000378:metabolism / Q000473:pathology; D008114:Liver Neoplasms, Experimental / Q000188:drug therapy / Q000378:metabolism / Q000473:pathology; D051379:Mice; D008822:Mice, Transgenic; D011355:Prodrugs / Q000378:metabolism / Q000627:therapeutic use*; D019098:Telomerase / Q000378:metabolism; D013942:Thymine Nucleotides / Q000378:metabolism / Q000627:therapeutic use*
chemical_list: D000970:Antineoplastic Agents; D011355:Prodrugs; D013942:Thymine Nucleotides; C556916:acycloguanosyl 5'-thymidyltriphosphate; D006151:Guanosine; D019098:Telomerase; D000212:Acyclovir
keywords: Acyclovir; Cancer therapy; Hepatocellular carcinoma; Telomerase; hTERT