title: Possible role of apoptosis in the pathogenesis and clinical evolution of radicular cyst: an immunohistochemical study.
abstract: OBJECTIVE
  To investigate whether the apoptotic cascade is activated through the extrinsic pathway in epithelial lining and connective tissue of radicular cysts.
  
  
  METHODS
  Fifteen radicular cysts were fixed in formalin, embedded in paraffin wax and processed for immunohistochemistry to evaluate the expression of polyclonal antibodies against Tumour necrosis factor-related apoptosis-inducing ligand (TRAIL), DR5 and caspase-3. Immunocomplexes were treated with the secondary antibodies and finally detected using the avidin-biotin-peroxidase complex. Immunoreactivity was visualized by development with 3,3'-diaminobenzidine. Data were analysed using the Mann-Whitney U-test; P < 0.05 was considered significant.
  
  
  RESULTS
  The three antibodies were detected in connective tissue fibroblasts of all radicular cysts; TRAIL and DR5 immunoexpression was significantly greater (P < 0.05) compared with that of caspase-3. The three antibodies were also expressed in almost all epithelial layers and in endothelial cells of newly formed vessels.
  
  
  CONCLUSIONS
  The involvement of apoptosis in the pathogenesis of radicular cysts, demonstrated by the immunoexpression patterns of TRAIL, DR5 and caspase-3 in lining epithelium and connective tissue, may explain their bland clinical aggressiveness and slow, benign evolution.
authors: Department of Bio-Medical Sciences, Section of Anatomy, University of Catania, Catania, Italy. carla.loreto@unict.it
authors: C
authors: C
authors: Loreto
authors: C
authors: C
authors: Galanti
authors: R
authors: R
authors: Leonardi
authors: G
authors: G
authors: Musumeci
authors: G
authors: G
authors: Pannone
authors: G
authors: G
authors: Palazzo
authors: M C
authors: MC
authors: Rusu
mesh_terms: D015100:3,3'-Diaminobenzidine; D000936:Antigen-Antibody Complex; D017209:Apoptosis / Q000502:physiology*; D053148:Caspase 3 / Q000032:analysis; D002452:Cell Count; D004396:Coloring Agents; D003238:Connective Tissue / Q000473:pathology; D003239:Connective Tissue Cells / Q000473:pathology; D042783:Endothelial Cells / Q000473:pathology; D004730:Endothelium, Vascular / Q000473:pathology; D004847:Epithelial Cells / Q000473:pathology; D005260:Female; D005347:Fibroblasts / Q000473:pathology; D006801:Humans; D007150:Immunohistochemistry; D008297:Male; D011842:Radicular Cyst / Q000209:etiology* / Q000473:pathology; D053220:Receptors, TNF-Related Apoptosis-Inducing Ligand / Q000032:analysis; D053221:TNF-Related Apoptosis-Inducing Ligand / Q000032:analysis
chemical_list: D000936:Antigen-Antibody Complex; D004396:Coloring Agents; D053220:Receptors, TNF-Related Apoptosis-Inducing Ligand; D053221:TNF-Related Apoptosis-Inducing Ligand; C505653:TNFSF10 protein, human; D015100:3,3'-Diaminobenzidine; D053148:Caspase 3