Document Type: Research Articles
Department of Physiology, King George’s Medical University, Lucknow, U.P., India.
Vice-Chancellor, King George’s Medical University, Lucknow, U.P., India.
Department of Biotechnology, Babasaheb Bhimrao Ambedkar University, Lucknow, U.P., India.
Department of Urology, King George’s Medical University, Lucknow, U.P., India.
PG Department of Pathology, King George’s Medical University, Lucknow, U.P., India.
Department of Surgical Oncology, King George’s Medical University, Lucknow, U.P., India.
Department of Oral & Maxillofacial Surgery, King George’s Medical University, Lucknow, U.P., India.
Background: The c-Fos nuclear protein dimerizes with Jun family proteins to form the transcription factor AP-1
complex which participates in signal transduction and regulation of normal cellular processes. In tumorigenesis, c-Fos
promotes invasive growth through down-regulation of tumor suppressor genes but its role in oral carcinogenesis is not
clear. Objectives: This study concerned c-fos gene expression in normal and malignant tissues of the oral cavity, with
attention to associations between expression status and clinico-pathological profiles of OSCC patients. Method: A total
of 65 histopathologically confirmed OSCC tissue samples were included in case group along with an equal number of
age and sex-matched normal tissue samples of oral cavity for the control group. c-Fos protein and m-RNA expressions
were analyzed using immunohistochemistry and qRT-PCR, respectively. Results: A significant low expression of c-Fos
protein was observed in OSCC cases than normal control subjects (p= <0.001). The mean percent positivity of c-Fos
protein in cases vs. controls was 24.91± 2.7 vs. 49.68± 2.2 (p= <0.001). Most OSCC tissue samples showed weak or
moderate c-Fos expression whereas 53.8% of normal tissue sections presented with strong immunostaining. Moreover,
the relative m-RNA expression for the c-fos gene was significantly decreased in case group (0.93± 0.48) as compared to
the control group (1.22± 0.87). Majority of c-Fos positive cases were diagnosed with well developed tumor. The mean
percent positivity of c-Fos protein was significantly lower in higher grade tumor as compared with normal oral mucosa
(p= < 0.001). Conclusion: The present study suggested that the c-fos gene is downregulated in oral carcinomas. The
disparity of c-Fos protein levels in different pathological grades of tumor and normal oral tissue samples may indicate
that loss of c-Fos expression is related with the progression of OSCC.