title: Combined 5-FU and ChoKα inhibitors as a new alternative therapy of colorectal cancer: evidence in human tumor-derived cell lines and mouse xenografts.
abstract: BACKGROUND
  Colorectal cancer (CRC) is the third major cause of cancer related deaths in the world. 5-fluorouracil (5-FU) is widely used for the treatment of colorectal cancer but as a single-agent renders low response rates. Choline kinase alpha (ChoKα), an enzyme that plays a role in cell proliferation and transformation, has been reported overexpressed in many different tumors, including colorectal tumors. ChoKα inhibitors have recently entered clinical trials as a novel antitumor strategy.
  
  
  RESULTS
  ChoKα specific inhibitors, MN58b and TCD-717, have demonstrated a potent antitumoral activity both in vitro and in vivo against several tumor-derived cell line xenografts including CRC-derived cell lines. The effect of ChoKα inhibitors in combination with 5-FU as a new alternative for the treatment of colon tumors has been investigated both in vitro in CRC-tumour derived cell lines, and in vivo in mouse xenografts models. The effects on thymidilate synthase (TS) and thymidine kinase (TK1) levels, two enzymes known to play an essential role in the mechanism of action of 5-FU, were analyzed by western blotting and quantitative PCR analysis. The combination of 5-FU with ChoKα inhibitors resulted in a synergistic effect in vitro in three different human colon cancer cell lines, and in vivo against human colon xenografts in nude mice. ChoKα inhibitors modulate the expression levels of TS and TK1 through inhibition of E2F production, providing a rational for its mechanism of action.
  
  
  CONCLUSIONS
  Our data suggest that both drugs in combination display a synergistic antitumoral effect due to ChoKα inhibitors-driven modulation of the metabolization of 5-FU. The clinical relevance of these findings is strongly supported since TCD-717 has recently entered Phase I clinical trials against solid tumors.
authors.affiliation: Traslational Oncology Unit, Instituto de Investigaciones Biomédicas, CSIC, Madrid, Spain.
authors.forename: Ana
authors.initials: A
authors.lastname: de la Cueva
authors.forename: Ana
authors.initials: A
authors.lastname: Ramírez de Molina
authors.forename: Néstor
authors.initials: N
authors.lastname: Alvarez-Ayerza
authors.forename: Ma Angeles
authors.initials: MA
authors.lastname: Ramos
authors.forename: Arancha
authors.initials: A
authors.lastname: Cebrián
authors.forename: Teresa Gómez
authors.initials: TG
authors.lastname: Del Pulgar
authors.forename: Juan Carlos
authors.initials: JC
authors.lastname: Lacal
mesh_terms: D000818:Animals; D000964:Antimetabolites, Antineoplastic / Q000494:pharmacology*; D000971:Antineoplastic Combined Chemotherapy Protocols; D017209:Apoptosis / Q000187:drug effects; D015153:Blotting, Western; D002073:Butanes / Q000494:pharmacology*; D049109:Cell Proliferation / Q000187:drug effects*; D002797:Choline Kinase / Q000037:antagonists & inhibitors* / Q000235:genetics / Q000378:metabolism; D015179:Colorectal Neoplasms / Q000188:drug therapy* / Q000378:metabolism / Q000473:pathology; D005260:Female; D005434:Flow Cytometry; D005472:Fluorouracil / Q000494:pharmacology*; D006801:Humans; D007124:Immunoenzyme Techniques; D051379:Mice; D008807:Mice, Inbred BALB C; D008819:Mice, Nude; D011726:Pyridinium Compounds / Q000494:pharmacology*; D012333:RNA, Messenger / Q000235:genetics; D034741:RNA, Small Interfering / Q000235:genetics; D060888:Real-Time Polymerase Chain Reaction; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013940:Thymidylate Synthase / Q000235:genetics / Q000378:metabolism; D014407:Tumor Cells, Cultured; D023041:Xenograft Model Antitumor Assays
chemical_list: C507944:1,4-(4-4'-Bis-((4-(dimethylamine)pyridinium-1-yl) methyl)diphenyl)butane dibromide; D000964:Antimetabolites, Antineoplastic; D002073:Butanes; D011726:Pyridinium Compounds; D012333:RNA, Messenger; D034741:RNA, Small Interfering; D013940:Thymidylate Synthase; C517212:CHKA protein, human; D002797:Choline Kinase; D005472:Fluorouracil