title: 6-Nitro-2-(3-hydroxypropyl)-1H-benz[de]isoquinoline-1,3-dione, a potent antitumor agent, induces cell cycle arrest and apoptosis.
abstract: BACKGROUND
  Anticancer activities of several substituted naphthalimides (1H-benz[de]isoquinoline-1,3-diones) are well documented. Some of them have undergone Phase I-II clinical trials. Presently a series of ten N-(hydroxyalkyl) naphthalimides (compounds 1a-j) were evaluated as antitumor agents.
  
  
  METHODS
  Compounds 1a-j were initially screened in MOLT-4, HL-60 and U-937 human tumor cell lines and results were compared with established clinical drugs. Cytotoxicities of compounds 1d and 1i were further evaluated in a battery of human tumor cell lines and in normal human peripheral blood mononuclear cells. Cell cycle analysis of compound 1i treated MOLT-4 cells was studied by flow cytometry. Its apoptosis inducing effect was carried out in MOLT-4 and HL-60 cells by flow cytometry using annexin V-FITC/PI double staining method. The activities of caspase-3 and caspase-6 in MOLT-4 cells following incubation with compound 1i were measured at different time intervals. Morphology of the MOLT-4 cells after treatment with 1i was examined under light microscope and transmission electron microscope. 3H-Thymidine and 3H-uridine incorporation in S-180 cells in vitro following treatment with 8 μM concentration of compounds 1d and 1i were studied.
  
  
  RESULTS
  6-Nitro-2-(3-hydroxypropyl)-1H-benz[de]isoquinoline-1,3-dione (compound 1i), has exhibited maximum activity as it induced significant cytotoxicity in 8 out of 13 cell lines employed. Interestingly it did not show any cytotoxicity against human PBMC (IC50 value 273 μM). Cell cycle analysis of compound 1i treated MOLT-4 cells demonstrated rise in sub-G1 fraction and concomitant accumulation of cells in S and G2/M phases, indicating up-regulation of apoptosis along with mitotic arrest and/or delay in exit of daughter cells from mitotic cycle respectively. Its apoptosis inducing effect was confirmed in flow cytometric study in MOLT-4 and the action was mediated by activation of both caspase 3 and 6. Light and transmission electron microscopic studies corroborated its apoptosis inducing efficacy at a concentration of 10 μM in MOLT-4 cells. Its apoptosis induction was also observed in HL-60 cells to an extent much greater than well known apoptosis inducing agents as camptothecin and cis-platin at 10 μM concentration each. It significantly inhibited DNA and RNA synthesis in S-180.
  
  
  CONCLUSIONS
  In essence, compound 1i showed potential as an antitumor agent.
authors.affiliation: Department of Anticancer Drug Development, Chittaranjan National Cancer Institute, Kolkata 700026, India.
authors.forename: Asama
authors.initials: A
authors.lastname: Mukherjee
authors.forename: Sushanta
authors.initials: S
authors.lastname: Dutta
authors.forename: Muthiah
authors.initials: M
authors.lastname: Shanmugavel
authors.forename: Dilip M
authors.initials: DM
authors.lastname: Mondhe
authors.forename: Parduman R
authors.initials: PR
authors.lastname: Sharma
authors.forename: Shashank K
authors.initials: SK
authors.lastname: Singh
authors.forename: Ajit K
authors.initials: AK
authors.lastname: Saxena
authors.forename: Utpal
authors.initials: U
authors.lastname: Sanyal
mesh_terms: D000970:Antineoplastic Agents / Q000494:pharmacology*; D017209:Apoptosis / Q000187:drug effects*; D002453:Cell Cycle / Q000187:drug effects*; D045744:Cell Line, Tumor; D004354:Drug Screening Assays, Antitumor; D006801:Humans; D053644:Naphthalimides / Q000494:pharmacology*
chemical_list: D000970:Antineoplastic Agents; D053644:Naphthalimides