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 using the expression of P53 phosphorylated on T18.
Material and Methods:Total of 28cancer patients on radiotherapy were participate in this study to collect blood samples pre and post radiotherapy compared to 28healthy people as control group matched in age and sex have been participated voluntary. All patients informed concern by written individual form. However, the study approved ethically from ministry of health, Khartoum, Sudan. P53 antibodies used against Phospho-p53 (Thr18) was obtained from CUSABIO using enzyme linked immunosorbent assay (ELISA) technique, and then optical density detected by colorimetric at 450 nm by SPECTRO star Nano microplate reader from BMG LABTECH.
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. Optical density (OD) P53 Phosphorylated (T18) 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 P53 phosphorylated (T18) expression postradiotherapy, while, nine patients were showed low P53(T18) 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. P53 phosphorylated T18 can be indict the DNA damage 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