Construction of single promoter double expression vector pIRES-p14ARF-p53 and its inhibitory effect on proliferation of osteogenic sarcoma cells / 中国组织工程研究

ABSTRACT

BACKGROUND: Previous researches indicate that ADp14ARF transfecting positive tumor cell line of p53 can inhibit the proliferation; in addition, the inhibitory effect is superior to transfection negative tumor cell line of p53. Whether simultaneous transfection of p14ARF and p53 genes can increase expression and accumulation of p53 and accelerate apoptosis of tumor cells needs further studies.OBJECTIVE: To construct double plasmid expression vector plRES-p14ARF-p53 by using gene engineering so as to observe the inhibitory effect on proliferation of osteogenic sarcoma cells.DESIGN: Randomized controlled observation.SETTING: Department of Orthopaedics, Union Hospital Affiliated to Tongji Medical College, Huazhong University of Science and Technology.MATERIALS The experiment was carried out in the Public Laboratory Platform, Immune Researching Room, Basic Medical College, Tongji Medical College, Huazhong University of Science and Technology from January 2005 to October 2006. Human osteogenic sarcoma MG-63 cells were provided by Cell Laboratory, Immune Researching Room, Tongji Medical College, Huazhong University of Science and Technology. plRES-p53 plasmid and plRES vector containing p53total-length gene order were provided by Wuhan Jingsai Biology Company.METHODS: Based on gene engineering, p14DNA (0.5 kb) was amplified from cultured L02 cells of normal human hepatic cells into plRES vector. Recombinant plasmid plRES-p14ARF-p53 was determined with polymerase chain reaction (PCR) and restriction enzyme and transfected into human osteogenic sarcoma MG-63 cells through mediation of liposome to screen positive clones. Otherwise, cells were divided into three groups, including blank control group (MG-63cells), blank vector control group (stably transfecting plRES-neo cells) and p14ARF-p53 group (stably transfecting plRES-p14ARF-p53 cells). ① DNA content and cycle of tumor cells were measured by using flow cytometry before and after transfection. ② Reverse transcription polymerase chain reaction (RT-PCR) and Western blot were used to detect quantitative and semi-quantitative expression of p53 and p14ARF protein in tumor cells after stable transfection. ③Thiazole blue chromatometry and growth curve were used to observe proliferation.MAIN OUTCOME MEASURES: ① DNA content and cycle of osteogenic sarcoma cells; ② expressions of p53 and p14ARF protein in tumor cells; ③ proliferation.RESULTS: Double plasmid expression vector plRES-p14ARF-p53 was constructed successfully. ① DNA content and cycle of osteogenic sarcoma cells Flow cytometry demonstrated that tumor cells mainly stayed in G1 phase after transfection. ② Protein expression RT-PCR and Western blot indicated that p14ARF and p53 gene independently expressed in target cell mRNA and protein, respectively. ③ Cell growth At 24, 48, 72 and 96 hours after MG-63 transfection, inhibitory rates of tumor cells were 33.43%, 69.37%, 66.19% and 75.26%, respectively, which was significant difference as compared with blank vector control group (P ＜ 0.01).CONCLUSION: Wild p53 and p14ARF can synergistically inhibit the proliferation and accelerate the apoptosis of osteogenic sarcoma cells.