Breast cancer is the most prevalent cancers worldwide and causes a significant amount of deaths annually. Spalt-like transcription factor 4 is known as a transcription factor, which has an important role in the proliferation of cancerous cells. Small interfering RNA (siRNA) is a short-chain molecule of 20 to 25 nucleotides that protrude on two sides of the 3′, two nucleotides. In this study, using a specific sequence of siRNA against the sequence of this gene, its activity is investigated in the cell line of breast cancer. The breast cancer cells (MCF-7) were cultured and then, using a specific anti-sal-like 4 (SALL4) siRNA, their toxic doses were determined. Then, the gene is transfected into the cell. Proliferation and expression of the SALL4 and BCL-2 gene were measured using the real-time polymerase chain reaction method. The specific concentration of siRNA IC 50 of the SALL4 gene was 40.35 nmole. Gene expression results indicated that the expression of the Bcl-2 gene in the siRNA group was significantly reduced (P < 0.05). SiRNA can increase the apoptosis of breast cancer cells by reducing the gene expression of SALL4 gene and Bcl-2; it can be used as a novel targeted therapy. This strategy, in addition to increasing the specificity of the drug, also reduces the side effects when compared with conventional chemotherapy. K E Y W O R D S biomarker, breast cancer, diagnosis, spalt-like transcription factor 4 | INTRODUCTIONBreast cancer is accounted as the most common malignancy in women worldwide. Breast cancer can be affected by a wide range of internal and external factors and is also characterized by molecular heterogeneity 1,2 and drug resistance is the major obstacle for its successful chemotherapy. 3 Despite various existing screening programs and new therapeutic strategies including gene therapy, 4,5 cell therapy, 6-13 and using a new generation of drug delivery systems 14-21 finding and developing new diagnostic and therapeutic approaches in the treatment of various cancers such as breast cancer are required. [22][23][24][25][26][27] To enhance the therapeutic efficacy of breast cancer, it is imperative to understand profoundly the molecular pathogenesis of cancer cells as well as identify newer candidate genes/proteins, which are crucial in the proliferating and J Cell Biochem. 2019;120:9392-9399. wileyonlinelibrary.com/journal/jcb 9392 |