Expression of p53, p21 CIP1/WAF1 and eIF4E in the adjacent tissues of oral squamous cell carcinoma: establishing the molecular boundary and a cancer progression model

Abstract

The present study evaluated the expression of key molecules and the status of DNA in both oral squamous cell carcinoma (OSCC) and adjacent tissues to establish a molecular surgical boundary and provide a cancer progression model. Biopsy samples from 50 OSCC patients were divided into T (cancer), P1 (0–0.5 cm), P2 (0.5–1 cm), P3 (1–1.5 cm) and P4 (1.5–2 cm) groups based on the distances from the visible boundary of the primary focus. Twenty samples of normal mucosa were used as controls. We used immunohistochemical staining and flow cytometry to evaluate p53, p21 CIP1/WAF1 , eIF4E and Ki-67 expression and to determine DNA status, respectively. Sub-mucosal invasion was present in the P1 and P2 groups as determined by haematoxylin and eosin staining. Mutant p53 expression decreased gradually from cancerous to normal mucosae, whereas p21 CIP1/WAF1 expression displayed an opposite trend. eIF4E expression decreased from cancerous to normal mucosae. Ki-67 expression, the heteroploidy ratio, S-phase fraction and proliferative index decreased gradually with the distance from the tumour centre. Based on these results, we suggest that the resection boundary in OSCC surgery should be beyond 2 cm from the tumour. Additionally, the adjacent tissues of the primary focus could be used as a model for assessing cancer progression.

Ki-67 protein predicts survival in oral squamous carcinoma cells: an immunohistochemical study

“…Despite the better understanding of the mechanisms responsible for cancer progression in recent years, the five-year survival rate of OSCC patients remains less than 50% throughout the world 16,17 . Based on this, molecular studies represent a useful tool to evaluate the role of proteins in the aggressiveness of human malignancies 17,18 .…”

“…Based on this, molecular studies represent a useful tool to evaluate the role of proteins in the aggressiveness of human malignancies 17,18 . In this study, we explored two important proliferation markers (Ki-67 and MCM3) in OSCC samples and their relation to clinical features and survival rates in order to obtain more accurate information about the clinical importance of these proteins in OSCC.…”

Phosphorylated ribosomal protein S6 correlation with p21 expression and inverse association with tumor size in oral squamous cell carcinoma

“…The tumor suppressor protein p53 can control the expression of the p21 gene, which mediates the p53‐dependent cell cycle G 1 phase arrest in response to a variety of stimuli . However, in post‐mitotic differentiated cells, such as spinous cells in squamous epithelia, p21 expression is differentiation‐dependent rather than p53‐dependent . It has been found that p21 expression is independent of the presence of functional p53 in HNSCC, but its expression is related to the differentiation of tumors.…”

“…Several studies have assessed the expression of p21 in OSCC . However, no consensus has been reached about its possible clinical significance.…”

“…21 Several studies have assessed the expression of p21 in OSCC. [22][23][24][25][26][27][28][29][30][31][32][33] However, no consensus has been reached about its possible clinical significance. Furthermore, the role of p21 as a tumor suppressor gene or an oncogene is still controversial.…”