Furthermore, PEITC treatment induced expression of pro-apoptotic genes in tumor cells, which was partially reversed by overexpression of PcG member BMI-1, suggesting opposing roles for PEITC and PcG proteins in control of tumor progression.
The high expression of BMI-1 in cervical cancer is related to tumor progression, lymph node metastasis and HPV infection, suggesting that cervical cancer with excessive BMI-1 expression possesses high metastases potential and that BMI-1 may be a promising biomarker for predicting metastasis in cervical cancer.
What's more, the levels of BMI-1 autoantibody increased significantly at stage I (0.672±0.019) compared to normal sera (P<0.001), and levels of BMI-1 autoantibodies were increased gradually during the tumor progression (stage I 0.672±0.019; stage II 0.775 ±0.019; stage III 0.890 ±0.027; stage IV 1.043±0.041), which were significantly correlated with disease progression of cervical cancer (P<0.001).
It is well known that BMI-1 over-expression was found in nasopharyngeal carcinoma cell lines and correlated with advanced invasive stage of the tumor progression and poor prognosis.