Introduction: Cancer is a common disease worldwide, and radiotherapy is an important option for cancer treatment. P53 tumour suppressor has a role in apoptosis and cancer treatment response. P53 is phosphorylated in response to ionizing radiation by kinases of the ataxia telangiectasia mutation family (ATM). The aim of this study was to detect the DND damage response in cancer patients before and after radiation therapy through measurements the expression levels of phosphorylated P53 on T18.
Material and Methods: Total of 28 cancer patients on radiotherapy were participate in this study to collect blood samples pre and post radiotherapy compared to 28 healthy people matched in age and sex as control group. P53 antibody used against Phospho-p53 (T18) was obtained from CUSABIO using enzyme linked immunosorbent assay (ELISA).
Results: 21 of patients were breast cancer, and 7 of patients were Head and Neck. 6 male and 22 female. Median of age was 44 years old. Median of body mass index (BMI) for breast cancer patients was 30 while BMI for head and neck was 23. The absorbed dose for breast cancer was 40.5Gy. While the doses for Head and neck cancers were between 20Gy- 66Gy. Phosphorylated P53 expression increased significantly (P= <0.0001) in the patients preradiotherapy compared to the control group. While no significant difference observed between preradiotherapy and postradiotherapy groups (P=0.7). Individually, 19 patients showed increased in phosphorylated P53 expression postradiotherapy, while, nine patients were showed low P53 postradiotherapy, 8 of them diagnosed with breast cancer and 1 diagnosed with Oesophagus.
Conclusion: phosphorylated on T18 can be consider a predictive marker for cancer. Phosphorylated P53 can be indict the DNA damage and response through its activation and proapoptotic effects. Protein expression such as P53 can be use as biomarker to demonstrate individual radiation sensitivity in cancer patients.
Keywords : Radiotherapy, P53, BMI, ELISA