title: Cyclin D1 an early biomarker in oral carcinogenesis.
abstract: BACKGROUND
  Dysregulation of cell cycle is a fundamental hallmark of cancer progression. Cyclin D1, part of complex molecular system regulating G1-S point of cell cycle is overexpressed in variety of tumors.
  
  
  OBJECTIVE
  To look for its immunohistochemical expression in clinically normal mucosa from patients with and without tobacco habits, leukoplakia; and correlate its expression to individual atypical morphologic features, as seen in hematoxylin and eosin (H and E) sections of leukoplakia exhibiting dysplasia.
  
  
  METHODS
  We examined the expression of cyclin D1 in immunohistochemically stained sections of 15 normal buccal mucosa without any habits (group 1), 30 clinically normal mucosa from tobacco habituιs (group 2) and 30 leukoplakias exhibiting dysplasias (group 3). Descriptive statistical analysis performed. Results presented on Mean ± Standard deviation and in number (%). Adjusted Wald 95% Confidence Interval (CI) computed, percentages of morphological features assessed by Laplace estimate. Mann-Whitney U, Kruskal-Wallis test used to find the percentage expression of cyclin D1.
  
  
  RESULTS
  Expression of cyclin D1 in group 3 was significantly higher than in group 1 and 2 (P < 0.001, P = 0.028), expression in group 2 was significantly higher than in group 1 (P = 0.003) and were statistically significant. Generally expression of cyclin D1 was confined to lower one-third of epithelium and was highest in mild dysplasias. Among 13 atypical morphologic features, cyclin D1 expression consistently correlated with basilar hyperplasia.
  
  
  CONCLUSIONS
  The altered pattern of cyclin D1 expression here may be an early event in conversion of normal epithelium into dysplastic epithelium and may serve as a biomarker of oral carcinogenesis. Its expression may be increased in tobacco habitués. Basilar hyperplasia should be given additional weightage in the grading system in predicting the fate of affected epithelium.
authors.affiliation: Department of Oral Pathology and Microbiology, College of Dental Sciences, Davangere, Karnataka, India.
authors.forename: Ashwini
authors.initials: A
authors.lastname: Ramakrishna
authors.affiliation: Department of Oral Pathology and Microbiology, Career Post Graduate Institute of Dental Sciences, Lucknow, Uttar Pradesh, India.
authors.forename: Balasundari
authors.initials: B
authors.lastname: Shreedhar
authors.affiliation: Department of Oral Pathology and Microbiology, Independent Dental Practitioner, The Oxford Dental College, Hospital and Research Center, Bengaluru, Karnataka, India.
authors.forename: Tv
authors.initials: T
authors.lastname: Narayan
authors.affiliation: Departments of Oral Pathology and Microbiology, The Oxford Dental College, Hospital and Research Center, Bengaluru, Karnataka, India.
authors.forename: Leeky
authors.initials: L
authors.lastname: Mohanty
authors.affiliation: Departments of Oral Pathology and Microbiology, The Oxford Dental College, Hospital and Research Center, Bengaluru, Karnataka, India.
authors.forename: Sadhana
authors.initials: S
authors.lastname: Shenoy
authors.affiliation: Departments of Oral Pathology and Microbiology, The Oxford Dental College, Hospital and Research Center, Bengaluru, Karnataka, India.
authors.forename: Saleha
authors.initials: S
authors.lastname: Jamadar
keywords: Cell cycle; cyclin D1; epithelial dysplasia; oral carcinogenesis; tobacco