Translational Medicine

Biography

Biography: Suoqin Tang

Abstract

Since the stability of siRNA molecules in the blood and efficiency of siRNA delivery into target organs or tissues following systemic administration have been the major issues that limit applications of siRNA in human patients, we try to explore if siRNA liposome entrapment works in the development of novel therapeutics. Our study aims to evaluate the therapeutic effect of survivin siRNA nano particles, on liver cancer, colon cancer and cervical cancer both in vitro and in vivo. First, sequences of survivin siRNA we designed had been screened for their efficacy, and the most effective one was chosen for the next study. Second, we have tested the biological effect of survivin siRNA nanoparticles on cancer cell lines in vitro, and resulted that, the survivin mRNA and its protein expression was significantly inhibited in MHCC-97H cells, HeLa cells and LoVo cells, also proliferation of those cell lines was inhibited and apoptosis was promoted. Third, subcutaneous xenograft Balb/c nude mice of MHCC-97H cells, HeLa cells or LoVo cells were established. Survivin siRNA nanoparticles(70.7±29.077nm in size), with dosage of 3 mg/kg survivin siRNA was given via local or intravenous injection, twice a week continuously for 4 weeks. As results, significant tumor growth inhibition both in local injection and venous injection was observed, compared to control mice who received scribbled siRNA nan particles at the same dosage, with inhibition rate of 32.22% and 36.67%, at the end of study in venous injection and local injection respectively, the relative tumor volume in mice with local injection showed significant less than control group from 10 days after first injection((P<0.05), till 31 days, it was also the same situation in mice with venous injection compared to control, (P<0.05) except day 17, survivin mRNA and its protein were down regulated at the end of study, compared to control group. Our study also showed some inhibition activity of survivin siRNA nanoparticles in subcutaneous xenograft Balb/c nude mice of HeLa or LoVo cells, survivin mRNA and protein expression was all down regulated in tumor tissue compared to control. We labeled the survivin siRNA with Cy3 florescence and intravenous injection to nude mice with MHCC-97H cells, and found intense Cy3 distribution in tumor mass, liver and spleen, but scant distribution in heart, brain, lung, bone marrow and gastrointestinal tract. Our study revealed that survivin siRNA nanoparticles were capable of inhibiting tumor growth both in vitro and in vivo.