Construction of expression vector of siRNA specific for STAT5a and identification of its efficiency in MGC803 gastric cancer cell line

Signal transducers and activators of transcription 5 (STAT5) has been shown to be involved in a variety of cellular processes, including survival, proliferation, invasion, angiogenesis and immune evasion and is frequently overexpressed in human solid tumors and blood malignancies. STAT5 is composed of two highly homologous isoforms, STAT5a and STAT5b, that are encoded by two separate genes with 96% similarity in their amino acid sequences. However, studies have revealed that STAT5a and STAT5b play different roles in the progression of various types of cancer cells. We choose STAT5a as our target gene to silence. In our study, we constructed STAT5a-specific siRNA successful ly. It showed in the experiment that STAT5a-specific siRNA could actively inhibit STAT5a expression in mRNA level in MGC803 gastric cancer cel1 line, and decrease STAT5a protein expression. From this experiment, we obtain the best siRNA sequence of STAT5a, which may serve as a new strategy for investigating the mechanism of molecular STAT5a pathology of gastric cancer targeted tumor gene therapy.