Research to present IADR Chilean Division Annual Meeting Valdivia 2010
Rivera, C*; Droguett, D; Donoso, W; Kemmerling, U; Venegas, B
Citation: Rivera C, Droguett D, Donoso W, Kemmerling U, Venegas B. Chronic stress in oral squamous cell carcinoma. J Dent Res Issue 89(Spec Iss C):77 (Chilean Division), 2010 (www.dentalresearch.org)
Aim: To determine the effect of chronic stress on the incidence and severity of 4-nitroquinoline-1-oxide (4-NQO) induced OSCC tongue lesions in CF-1 mice.
Materials and methods: All experimental protocols were approved by the Bioethics Committee of the Universidad de Talca. 120 CF-1 male mice were divided into four groups: A) (n= 50), received two treatments: 1) Application of chronic stress by movement restriction for two hours daily on three non-consecutive cycles of 5 weeks, 2) Chemical induction of carcinogenesis, applying a propylene/4-NQO solution in drinking water for a period of 16 weeks. B) (n= 50), received chemical induction of carcinogenesis, without stress. C) (n= 10) received only the stress treatment. D) (n= 10) without any treatment. After 28 weeks, euthanasia, dissection and tongue necropsy was performed. Incidence was analyzed by conventional hematoxylin-eosin study. Severity was determined by means of studying the differentiation degree applying the International Histological Classification of Tumors, and Bryne’s multifactorial grading system for the invasive tumor front (ITF). Plasma corticosterone levels were determined after movement restriction procedures. Chi-square and Mann-Whitney U-test statistical methods were used.
Results: Statistical significance was found in plasma corticosterone levels after the first movement restriction cycle (p=0,05 Mann-Whitney U-test).
Conclusion: Movement restriction induced chronic stress modifies plasma corticosterone levels, but does not increase incidence and severity of 4-NQO induced OSCC in the tongue of CF-1 mice.