The staining patterns of 53BP1 nuclear foci and 53BP1 mRNA level are associated with cervical cancer progression and metastasis.

p53-binding protein 1 (53BP1) plays a key role in DNA damage response mechanism, which protects genome integrity and guards against cancer. Although abnormal DNA damage response type of 53BP1 nuclear foci (NF) have been indicated to be associated with many types of malignancies, how the staining pattern of 53BP1 NF and the mRNA level of 53BP1 correlate with the clinicopathologic characteristics of cervical cancer is still unclear. In this study, we examined the staining pattern and mRNA level of 53BP1 in cervical premalignant and malignant lesions and normal cervical tissue by immunofluorescence staining and quantitative real-time polymerase chain reaction. We found that the level of 53BP1 NF increased in the following order: normal cervical tissues, cervical intraepithelial neoplasia (CIN) 1, CIN2/3, and cervical cancers, indicating that the level of 53BP1 NF increases as cervical cancer initiates and progresses. In addition, we also found that abnormal DNA damage response type of 53BP1 NF and low mRNA level of 53BP1 was significantly correlated with high histologic grade of cervical cancer, and low mRNA level of 53BP1 was also significantly associated with positive lymph node metastasis of cervical cancer.