Subject(s)
Basal Cell Nevus Syndrome/pathology , Mandibular Neoplasms/pathology , Maxillary Neoplasms/pathology , Neoplasms, Multiple Primary/pathology , Odontogenic Tumors/pathology , Adult , Basal Cell Nevus Syndrome/complications , Basal Cell Nevus Syndrome/diagnostic imaging , Diagnosis, Differential , Humans , Male , Mandibular Neoplasms/complications , Mandibular Neoplasms/diagnostic imaging , Maxillary Neoplasms/complications , Maxillary Neoplasms/diagnostic imaging , Neoplasms, Multiple Primary/diagnostic imaging , Odontogenic Tumors/complications , Odontogenic Tumors/diagnostic imaging , RadiographyABSTRACT
Thymosin beta4 (Tbeta(4)) is a naturally occurring, ubiquitous, non-toxic protein with documented wound-healing, anti-inflammatory, anti-apoptotic, and tissue-repair properties in skin, the ocular surface, and the heart. The ability of Tbeta(4) to demonstrate similar protective properties in cells of the oral cavity was analyzed using an in vitro model of cultured human gingival fibroblasts. Thymosin beta 4 significantly suppressed the secretion of interleukin-8 (IL-8) following stimulation with tumor necrosis factoralpha (TNF-alpha), suggesting that it may suppress the inflammatory response initiated by pro-inflammatory cytokines. By contrast, Tbeta(4) was not effective in protecting fibroblasts from challenge with lipopolysaccharide purified from Porphyromonas gingivalis or Escherichia coli. Thymosin beta 4 was able to protect gingival fibroblasts against the known cytotoxic effects of chlorhexidine digluconate, a mouthrinse containing chlorhexidine digluconate, and carbamide peroxide. Additionally, Tbeta(4) was able to protect gingival fibroblasts from the apoptosis that is induced by stimulation with TNF-alpha or by exposure to chlorhexidine. Because of its multifunctional roles in protecting cells against damage, Tbeta(4) may have significant potential for use as an oral heathcare aid with combined antimicrobial, anti-inflammatory, anti-apoptotic, and cytoprotective properties.
Subject(s)
Cytoprotection , Gingiva/drug effects , Interleukin-8/antagonists & inhibitors , Thymosin/pharmacology , Anti-Infective Agents, Local/antagonists & inhibitors , Apoptosis/drug effects , Carbamide Peroxide , Cells, Cultured , Chlorhexidine/analogs & derivatives , Chlorhexidine/antagonists & inhibitors , Drug Combinations , Fibroblasts/drug effects , Fibroblasts/immunology , Gingiva/cytology , Gingiva/immunology , Humans , Lipopolysaccharides/pharmacology , Mouthwashes , Oxidants/antagonists & inhibitors , Peroxides/antagonists & inhibitors , Toxicity Tests , Tumor Necrosis Factor-alpha/pharmacology , Urea/analogs & derivatives , Urea/antagonists & inhibitorsABSTRACT
High-grade gliomas are devastating brain tumors associated with a mean survival of <50 weeks. Two of the most common genetic changes observed in these tumors are overexpression/mutation of the epidermal growth factor receptor (EGFR) vIII and loss of PTEN/MMAC1 expression. To determine whether somatically acquired EGFRvIII expression or Pten loss accelerates high-grade glioma development, we used a previously characterized RasB8 glioma-prone mouse strain, in which these specific genetic changes were focally introduced at 4 weeks of age. We show that both postnatal EGFRvIII expression and Pten inactivation in RasB8 mice potentiate high-grade glioma development. Moreover, we observe a concordant loss of Pten and EGFR overexpression in nearly all high-grade gliomas induced by either EGFRvIII introduction or Pten inactivation. This novel preclinical model of high-grade glioma will be useful in evaluating brain tumor therapies targeted to the pathways specifically dysregulated by EGFR expression or Pten loss.
