title: Incubation with DNase I inhibits tumor cell proliferation.
abstract: BACKGROUND
  Deoxyribonuclease I (DNase-I) plays an important role in the elimination of damaged-, aging- or cancer cells. Various authors suggest that programmed cell death (PCD) is attenuated in cancer cells due to a reduced activity of DNase-I.
  
  
  METHODS
  In this work, we evaluated cell viability (violet crystal stain), cell proliferation (tritiated thymidine) and DNA degradation of tumoral cells (Calu-1, SK-MES-1, HeLa, HEp-2, L-929) incubated with different concentrations of DNase I. PBMN cells and human fetal fibroblasts served as controls.
  
  
  RESULTS
  Our results showed a >90% decrease in the viability of HeLa and HEp-2 cells, and >50%<90% decline in Calu-1, SK-MES-1 and L-929 cell viability, incubated with 9 mg/ml of DNase-I in comparison with control cells (p<0.05). The incorporation of [3H]thymidine showed a 50% decrease in tumoral cells. Control cells showed no significant differences. Tumor cell DNA degradation was observed after nuclease treatment, however the typical DNA ladder, characteristic of the apoptotic cell, was not observed. The morphology of some DNAse-I treated tumor cells suggested autoschizis
  
  
  CONCLUSIONS
  Our results suggest that the use of a DNA nuclease might have some benefits in the treatment of cancer since it inhibits cell growth, probably by inducing autoschizis.
authors.affiliation: Institute of Scientific Research Hans Selye, Queretaro, Qro., México.
authors.forename: Susana
authors.initials: S
authors.lastname: Alcázar-Leyva
authors.forename: Eduarda
authors.initials: E
authors.lastname: Cerón
authors.forename: Felipe
authors.initials: F
authors.lastname: Masso
authors.forename: Luis F
authors.initials: LF
authors.lastname: Montaño
authors.forename: Patricia
authors.initials: P
authors.lastname: Gorocica
authors.forename: Noé
authors.initials: N
authors.lastname: Alvarado-Vásquez
mesh_terms: D000818:Animals; D045744:Cell Line, Tumor; D049109:Cell Proliferation / Q000187:drug effects; D048430:Cell Shape / Q000187:drug effects; D002470:Cell Survival / Q000187:drug effects; D004247:DNA / Q000032:analysis; D003850:Deoxyribonuclease I / Q000494:pharmacology*; D006801:Humans; D008297:Male; D051379:Mice; D009369:Neoplasms / Q000473:pathology*; D013936:Thymidine / Q000378:metabolism
chemical_list: D004247:DNA; D003850:Deoxyribonuclease I; D013936:Thymidine