TFDP3 regulates the apoptosis and autophagy in breast cancer cell line MDA-MB-231.

Cancer/testis antigen TFDP3 belongs to the transcription factor DP(TFDP) family. It can bind to E2F family molecules to form a heterodimeric transcription factor E2F/TFDP complex. The complex is an important regulatory activator of cell cycle, involved in the regulation of cell proliferation, differentiation, apoptosis and other important physiological activities. In addition, TFDP3 has also been found to be a tumor-associated antigen that only expresses in malignant tumor tissue and normal testicular tissue; Thus, it is closely related to tumor occurrence and development. In this study, our group investigated the expression of TFDP3 in mononuclear cell samples from a variety of tissue-derived malignant tumors, breast cancer and benign breast lesions. The results show that TFDP3 is expressed in the malignant form of various tissues. Moreover, our recent research had focused on the ability of TFDP3 to influence the drug resistance and apoptosis of tumor cells. To further clarify the mechanisms involved in tumor resistance, this study also examined the expression of TFDP3 and tumor cell autophagy regulation; Autophagy helps cells cope with metabolic stress (such as in cases of malnutrition, growth factor depletion, hypoxia or hypoxia) removes erroneously folded proteins or defective organelles to prevent the accumulation of abnormal proteins; and removes intracellular pathogens. Our results showed that TFDP3 expression can induce autophagy by up-regulating the expression of autophagic key protein LC3(MAP1LC3) and increasing the number of autophagosomes during chemotherapy of malignant tumors. Then, DNA and organelles damage caused by the chemotherapy medicine are repaired. Thus, TFDP3 contributes toward tumor cell resistance. When siRNA inhibits TFDP3 expression, it can reduce cell autophagy, improving the sensitivity of tumor cells to chemotherapy drugs.