title: Immunohistochemical Expression of Cyclin B1 in Epithelial Hyperplasia, Dysplasia and Oral Squamous Cell Carcinomas - A Comparative Study.
abstract: BACKGROUND
  Cyclin B1 is important in the cell cycle progression from G2 to M phase. Cyclin B1 binds to CDC2, which then becomes dephosphorylated and gets relocated to the nucleus, ensuring the transition toward mitosis.
  
  
  OBJECTIVE
  Over expression of Cyclin B1, has been reported more recently in breast, colon, prostate, oral and esophageal carcinomas. Thus, the aim of the present study was to examine the expression of Cyclin B1 in hyperplasia, dysplasia and Oral Squamous Cell Carcinomas (OSCC).
  
  
  METHODS
  A total of 64 histopathologically diagnosed cases of epithelial hyperplasias, dysplastic oral epithelium and OSCC were included in the study. Immunohistochemical procedure was carried out using the monoclonal mouse Cyclin B1 antibody (Clone V-152). The Cyclin B1 positive tumor cells counted were expressed as percentage of positive tumor cells. Nuclear and cytoplasmic labeling index (n&cLI) were calculated. The results were tabulated and statistically analyzed by Kruskal Wallis test- One Way ANOVA and Mann Whitney U- test.
  
  
  RESULTS
  Combined n&cLI was considered only in 28.57% of epithelial hyperplasias, 40.7% of oral epithelial dysplasias and 72% of OSCC showed over expression of Cyclin B1 with p value being 0.029. Cyclin B1 expression was not significantly different between the grades of dysplasia, between the grades of OSCC and between the marginal groups.
  
  
  CONCLUSIONS
  The present study demonstrates more than 50% of the study group showing less than 20% of nuclear staining. The importance of such variations within a type of lesion requires further investigation, since Cyclin B1 has proved useful in many studies from esophageal and laryngeal squamous cell carcinoma as a prognostic indicator, an indicator of recurrence and as an indicator for tumor sensitivity to radiotherapy. Further studies are to be extended towards evaluating the role of Cyclin B1 as a prognostic indicator.
authors: Reader, Department of Oral and Maxillofacial Pathology, SDM College of Dental Sciences and Hospital , Dharwad, Karnataka, India .
authors: Kochli Channappa
authors: KC
authors: Niranjan
authors: Professor, Department of Oral and Maxillofacial Pathology, SDM College of Dental Sciences and Hospital , Dharwad, Karnataka, India .
authors: Amsavardani
authors: A
authors: Tayaar
authors: Principal, Professor and Head of Department, Department of Oral and Maxillofacial Pathology, K.S.R. Institute of Dental Science and Research , Tiruchengode, Tamil Nadu, India .
authors: G S
authors: GS
authors: Kumar
authors: Professor, Department of Oral and Maxillofacial Pathology, Anoor Dental College , Ernakulam, Kerala, India .
authors: Rekha
authors: R
authors: Krishnapillai
authors: Professor, Department of Oral and Maxillofacial Pathology, SDM College of Dental Sciences and Hospital , Dharwad, Karnataka, India .
authors: Kaveri
authors: K
authors: Hallikeri
authors: Professor, Department of Oral and Maxillofacial Pathology, Navodaya Dental College , Raichur, Karnataka, India .
authors: Santosh
authors: S
authors: Hunasgi
keywords: Carcinogenesis; Cell cycle regulators; Immunohistochemistry; Oral lesions