Mohammad Kamalabadi Farahani - Department of Tissue Engineering and Applied Cell Sciences, Faculty of Advanced Technologies in Medicine, Tehran University of Medical Sciences, Tehran, Iran
Zahra Jabbarpour - Department of Molecular Medicine, Faculty of Advanced Technologies in Medicine, Tehran University of Medical Sciences, Tehran, Iran

Introduction Metastasis is a major cause of fatality in breast cancer. Incancer, metastasis and resistance to chemotherapy are linked phenomenon. TNF-related apoptosis inducing ligand (TRAIL) ispromising biological agent with a selective apoptotic property of tumor cells through interaction with the death receptors. However, their therapeutic potential is limited as a large number of tumor cells develop resistance toward TRAIL. Various reasons have been mentioned for TRAIL resistance in tumor cells. Defective death receptor function can be one of the reasons involved in this resistance. Objectives In the present study, we compared the expression of DR5, as the main receptor of the TRAIL, in metastatic and primary breast tumor cells.Methods4T1 cell line were used for induction of metastatic animal model of breast cancer. Primary and metastatic tumor cells were extracted from subcutaneous primary tumor and lung of cancerous mice respectively. The expression levels of DR5 was evaluated in both cell types by Quantitative Real-Time PCR. Results Primary and metastatic tumor cells were successfully isolated. Based on the results, DR5 expression in lung metastatic tumor cells was significantly reduced compared with primary tumor cells. Conclusion These findings provide important insights regarding the molecular mechanism of apoptosis resistance of metastatic tumor cells. It will provide the basis for designing therapeutic methods to overcome this resistance.

Breast cancer, Metastasis, DR5, Apoptosis, TRAIL