The relationship between p27^kip1 expression and the change of radiosensitivity of esophageal carcinoma cells

Abstract

Objective. Radioresistance is considered the main reason for therapeutic failure in radiotherapy of esophageal carcinoma. However, the underlying mechanisms of radioresistance remain elusive. The purpose of this study was to investigate the relationship between p27^kip1 expression and the change of radiosensitivity of esophageal carcinoma cells. Material and methods. Radioresistant cells were gradually isolated by means of repeated gamma-ray irradiation upon esophageal carcinoma cells. The radiosensitivity of established radioresistant cells and parental cells was measured by standard colony-forming assay. Cell cycle was detected by flow cytometry. Western blot method was performed to identify the expression of p27^kip1. Results. Colony-forming assay showed that the radioresistant cells had obvious radioresistance. Percentage of the radioresistant cells at G₀/G₁ and G₂/M phase was significantly decreased, and the percentage of S phase cells was significantly increased compared with the parent cells (p < 0.05). Western blotting revealed that p27^kip1 expression of the radioresistant cells was lower than that of parent cells. Conclusions. Our results suggest that cell phase change due to the decrease of p27^kip1 expression is one of the mechanisms of radioresistance in esophageal carcinoma cells.

Key Words::

• Esophageal carcinoma
• p27^kip1
• radioresistance

Declaration of interest: The authors report no conflicts of interest. The authors alone are responsible for the content and writing of the paper.