title: 6 Iodo-δ-lactone: a derivative of arachidonic acid with antitumor effects in HT-29 colon cancer cells.
abstract: BACKGROUND
  IL-δ (5-hydroxy-6 iodo-8,11,14-eicosatrienoic delta lactone) an iodinated arachidonic acid (AA) derivative, is one of the iodolipids biosynthesized by the thyroid. Although IL-δ regulates several thyroid parameters such as cell proliferation and goiter growth it was found that this iodolipid inhibits the growth of other non thyroid cell lines.
  
  
  OBJECTIVE
  To study the effect of IL-δ on cell proliferation and apoptosis in the colon cancer cell line HT-29.
  
  
  RESULTS
  Treatment with IL-δ reduced cell viability in a concentration-dependent manner: 1μM 20%, 5μM 25%, 10μM 31%, 50μM 47% and caused a significant decrease of PCNA expression (25%). IL-δ had pro-apoptotic effects, evidenced by morphological features of programmed cell death such as pyknosis, karyorrhexis, cell shrinkage and cell blebbing observed by fluorescence microscopy, and an increase in caspase-3 activity and in Bax/Bcl-2 ratio (2.5 after 3h of treatment). Furthermore, IL-δ increased ROS production (30%) and lipid peroxidation levels (19%), suggesting that apoptosis could be a result of increased oxidative stress. A maximum increase in c-fos and c-jun protein expression in response to IL-δ was observed 1h after initiation of the treatment. IL-δ also induced a tumour growth delay of 70% compared to the control group in NIH nude mice implanted with HT-29 cells.
  
  
  CONCLUSIONS
  Our study shows that IL-δ inhibits cell growth and induces apoptosis in the colon cancer cell line, HT-29 and opens the possibility that IL-δ could be a potential useful chemotherapy agent.
authors: Nuclear Biochemistry Division, Argentine National Atomic Energy Commission Buenos Aires 1429, Argentina.
authors: Lisa
authors: L
authors: Thomasz
authors: Romina
authors: R
authors: Oglio
authors: Luciano
authors: L
authors: Rossich
authors: Sonia
authors: S
authors: Villamar
authors: Marina
authors: M
authors: Perona
authors: Leonardo
authors: L
authors: Salvarredi
authors: Alejandra
authors: A
authors: Dagrosa
authors: Mario A
authors: MA
authors: Pisarev
authors: Guillermo J
authors: GJ
authors: Juvenal
mesh_terms: D000970:Antineoplastic Agents / Q000737:chemistry* / Q000494:pharmacology*; D017209:Apoptosis / Q000187:drug effects; D016718:Arachidonic Acid / Q000737:chemistry*; D001095:Arachidonic Acids / Q000737:chemistry* / Q000494:pharmacology*; D049109:Cell Proliferation / Q000187:drug effects; D019073:HT29 Cells; D006801:Humans
chemical_list: C026915:6-iodo-5-hydroxy-eicosatrienoic acid, delta-lactone; D000970:Antineoplastic Agents; D001095:Arachidonic Acids; D016718:Arachidonic Acid