Related Experiment Videos
De novo programmed cell death in oral cancer
D Ravi1, K Ramadas, B S Mathew
1Division of Laboratory Medicine, Regional Cancer Centre, Thiruvananthapuram, Kerala State, India.
Aim:
The importance of programmed cell death or apoptosis in the maintenance of tissue homoeostasis and the pathogenesis of oral cancer was analysed in relation to apoptosis regulatory proteins, tissue proliferation and tumour histology.
Methods And Results:
The extent of apoptosis was defined by morphological criteria and the TUNEL (terminal deoxy nucleotidyl transferase-mediated dUTP biotin nick end labelling) assay. p53, bax, bcl-2 and cyclin D1 expression was evaluated by immunocytochemistry. The presence of mutant p53 was analysed using a mutant p53-specific ELISA. An inverse correlation was observed between TUNEL reactivity and histology of the lesion (r = -0.555, P = 0.0001). There was also correlation between TUNEL reactivity and immunoreactivity of apoptosis regulatory proteins. p53 (r = 0.641, P = 0.00023), bcl-2 (r = -0.642, P = 0.00014) and bax (r = 0.651, P = 0.00002). The presence of mutant p53 protein showed an inverse correlation to the extent of apoptosis (r = - 0.301, P = 0.00063). Significant correlation was evident between the bax/bcl-2 ratio and TUNEL (r = 0.652, P = 0.00001) as well as between cyclin D1 and TUNEL reactivity (r = 0.577, P = 0.00001).
Conclusions:
Results from this study suggest that apoptosis decreases as histological abnormality increases. Apoptotic regulatory proteins are also altered in a histologically dependent manner. Deregulated proliferation occurs simultaneously with decreased apoptosis during tumour progression in the oral mucosa.
Insights
Apoptosis, programmed cell death, decreases with increasing oral cancer abnormality. This is linked to altered apoptosis regulatory proteins and deregulated proliferation during tumor progression.
Area of Science:
- Oncology
- Cell Biology
- Molecular Pathology
Background:
- Apoptosis is crucial for tissue homeostasis.
- Dysregulation of apoptosis is implicated in oral cancer pathogenesis.
Purpose of the Study:
- To analyze apoptosis in oral cancer.
- To investigate the relationship between apoptosis, regulatory proteins, proliferation, and tumor histology.
Main Methods:
- Morphological assessment and TUNEL assay for apoptosis.
- Immunocytochemistry for p53, bax, bcl-2, and cyclin D1.
- ELISA for mutant p53 detection.
Main Results:
- Apoptosis inversely correlated with lesion histology.
- Apoptosis correlated with p53, bcl-2, and bax expression.
- Mutant p53 inversely correlated with apoptosis.
- Bax/bcl-2 ratio and cyclin D1 correlated with apoptosis.
Conclusions:
- Apoptosis decreases as histological abnormality increases in oral lesions.
- Apoptosis regulatory proteins change in a histology-dependent manner.
- Deregulated proliferation and decreased apoptosis occur during oral tumor progression.