Prognostic implication of the expression of minichromosome maintenance protein 5 (MCM 5) in oral cavity squamous cell carcinomas-a study on cases from a tertiary care centre

Minichromosome maintenance (MCM) proteins play a vital role in cell cycle progression. The MCM 5 protein is one of the key proteins that binds to Chromatin in a cell cycle dependent manner and restricts the replication of the chromosome to only one round per cell cycle. To evaluate the role of MCM5 in the biological behavior of Oral Cavity Squamous cell carcinomas of patients from a tertiary care centre. This study evaluated the immunohistochemical expression of MCM-5 protein in primary oral squamous cell carcinomas(n=90). Formalin Fixed Paraffin Embedded tissue (FFPE) sections of the tumors were immunhistochemically stained with the monoclonal antibody MCM-5 (EP-84, Pathnsitu, Livermore, CA, USA). The correlation between the expression of MCM5 and clinico-pathological features of the dysplastic lesions and oral squamous cell carcinoma tumors was analysed. The association between the expression of MCM5 and patient outcomes was also evaluated. The mean nuclear MCM5 LI for the 90 cases of OSCC ranged from 0-90 (mean 52.88 +- 2.084). A higher mean nuclear MCM5 LI was associated with the higher histological tumor grade (p=0.002). Tumors of an advanced clinical stage had a higher mean nuclear MCM5 LI compared to tumors of an early clinical stage (p=0.039) The MCM-5 protein is a key molecule that is altered during the carcinogenic process of squamous cell carcinomas of the oral cavity. A higher expression of MCM5 is indicative of aggressive tumor behaviour of oral cavity squamous cell carcinomas. • MCM-5 protein located on chromosome 22.q13.1 initiates DNA replication • Promotes proliferation of cells in OSCC • MCM-5 Labelling Index is associated with aggressive tumor behavior • MCM -5 labelling index is higher in tumors of advances stage and grade of tumors