title: Immunohistochemical characterization of cyclin dependent kinase-4 in different histological grades of oral leukoplakia and oral squamous cell carcinoma.
abstract: BACKGROUND
  Cyclin dependent kinase-4 (CDK4) encoded by CDK gene, is a heterodimer protein of cell cycle in G1-S transition. This study aimed to characterize the CDK4 immunoreactivity in different histological grades of oral leukoplakias (OLs) and oral squamous cell carcinomas (OSCCs) and also aims to discuss its probable role in the tumor biogenesis.
  
  
  METHODS
  Expression of CDK4 was investigated in total of 52 samples including OL (15), OSCCs (30) and normal oral tissues (07). A labeled Streptavidin-Biotin immunohistochemistry assay was performed and staining intensity was evaluated.
  
  
  RESULTS
  The staining pattern was similar in all tissues and was located in both nuclei and cytoplasm. Dysplastic epithelium displayed a progressive increase in nuclear expression of CDK4 when compared to normal tissues. Also, positive staining cytoplasm was highly evident in OSCC with loss of differentiation.
  
  
  CONCLUSIONS
  Our study indicated a progressive over expression of CDK4 from normal to leukoplakias (various histological grades of dysplasias) and OSCCs.
authors: Department of Oral and Maxillofacial Pathology, Government Dental College and Hospital, Hyderabad, Andhra Pradesh, India.
authors: Ndvn
authors: N
authors: Shyam
authors: Department of Oral and Maxillofacial Pathology, Manipal College of Dental Sciences, Manipal, Karnataka, India.
authors: Nirmala N
authors: NN
authors: Rao
authors: Department of Oral and Maxillofacial Pathology, SGRD Institute of Dental Sciences and Research, Amritsar, Punjab, India.
authors: Raman Ds
authors: RD
authors: Narang
authors: Department of Oral and Maxillofacial Pathology, BBD College of Dental Sciences, Lucknow, Uttar Pradesh, India.
authors: Jiji
authors: J
authors: George
authors: Department of Oral and Maxillofacial Pathology, Boston University Henry M. Goldman School of Dental Medicine, Boston, MA, USA.
authors: Sanjay R
authors: SR
authors: Bommu
authors: Department of Oral and Maxillofacial Pathology, Government Dental College and Hospital, Hyderabad, Andhra Pradesh, India.
authors: G
authors: G
authors: Kiran
keywords: Cyclin dependent kinase-4; leukoplakia; oral squamous cell carcinomas; tumor biogenesis