Role of autophagy in cancer

Breast cancer is the most common among in women. In recent years, it has led to the development of new diagnostic and therapeutic strategies, a better understanding of gene expression, molecular biology of breast cancer. However, the triple negative breast cancer is not available still specific treatment. Autophagy is a cellular process that destruction of long-lived proteins, organelles with lysosomal enzyme activity. It has been shown that deficient autophagy result in cancer, infection, neurodegenerative diseases. Also, it is referred as programmed cell death II. The role of autophagy in cancer is unclear. It has been suggested that tumor formation is inhibited by autophagy which reduces oxidative stress, recycling damaged organelles. On the contrary, it is suggested that autophagy protects tumor cells under conditions such as starvation, deficiency of growth hormone and hypoxia, so it can be oncogenic. In our study expression of 63 autophagy related gene was investigated by RT-PCR technique, using 69 normal and tumor tissues in breast cancer patients. It was found that the expression of this gene were significantly lower than tumor tissue. In addition, UVRAG was silenced in MDA-MB-231 breast cancer cell line using specific siRNA. It was found knockdown of UVRAG decreased markedly cell proliferation, colony formation, invasion and cell migration. As a result, it is thought that autophagy may play an important role in cancer cell as programmed cell death II and, potentially, be used as a new therapeutic target for triple breast cancer treatment.