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BACKGROUND:With the development of science and technology and modern aerospace, the effects of mechanobiology in extreme mechanical environment—high acceleration are becoming an issue of concern. Studies have shown that high acceleration has certain effects on the cels. OBJECTIVE:Based on a centrifuge, to design a cel loading centrifuge used for exploration of cel mechanobiology under high acceleration. METHODS:For the cel loading centrifuge, a culture plate or/and culture bottle ful of culture fluid was/were loaded with constant acceleration or variable velocity to explore the experimental feasibility. Besides, a finite element model was built by ANSYS software according to structure and properties of the rotor. The rotor system was calculated under equilibrium and dangerous working conditions, respectively, to analyze the stress and deformation distribution. Moreover, the strength of the main shaft was checked under the dangerous working conditions. Then the analysis results of ANSYS were compared with the results of strength check. RESULTS AND CONCLUSION:Experimental findings showed that the culture plate or/and the culture bottle could be used for (0-40)×g highly constant acceleration or variable acceleration loading. Through the simulation and comparison analysis, we confirmed the reliability of the cel loading centrifuge. This cel loading centrifuge can be used to implement the study of cel mechanobiology under high acceleration in the general biology laboratory. It also provides a basis for wide application of cel loading centrifuge in the future.
RESUMO
Background and purpose:The signal transducers factor and activator in transcription 3(STAT3) is a recently studied gene from a variety of solid tumors such as breast, stomach, and ovarian cancer, in which the increase of abnormal expression and activity are accompanied.The aim of this study was to investigate the effects of eukaryotic vectors that express short hairpin RNA(shRNA) in signal transducers and activators of STAT3 on chemosensitivity of human ovarian cancer SKOV3 cells.Methods:Vectors containing shRNA targeting STAT3(pSTAT3-siRNA) were constructed and transfected into SKOV3 cells.These vectors were then divided into 3 groups:SKOV3, SKOV3NS, and SKOV3siRNA.The mRNA and protein expressions of STAT3 were determined by RT-PCR and Western blot, respectively.The growth inhibition and apoptosis rates of the different group cells under chemotherapeutic agents such as cisplatin(20 ?mol/L) were measured by MTT assay and flow cytometry(FCM).Results:MTT assay growth inhibition rates in the tumor cells of the SKOV3 group, SKOV3NS group and SKOV3siRNA group had inhibition rates of 0.46?0.13, 0.44?0.11 and 0.71?0.12.Compared with the SKOV3, SKOV3NS and SKOV3siRNA group, there was a marked increase of SKOV3siRNA group in inhibition rate of cells.The differences were also statistically significant(P0.05).The SKOV3 group, SKOV3NS group and SKOV3siRNA group's cell apoptosis rates were 18?4, 18?3 and 35?4, respectively.However, the SKOV3 group, SKOV3NS group, and SKOV3siRNA group cell apoptosis were significantly increased and the differences were statistically significant(P0.05).The results for the SKOV3 group, SKOV3NS group and SKOV3siRNA in cell STAT3 mRNA were 0.50?0.08, 0.48?0.07 and 0.31?0.09.With the SKOV3 group, SKOV3NS group, SKOV3siRNA group of cells in STAT3 mRNA, its expression in the lungs were significantly lower and the differences were statistically significant(P0.05).SKOV3 group, SKOV3NS group and SKOV3siRNA group of cells checked the results of STAT3 protein were 0.54?0.09, 0.56?0.08 and 0.32?0.09, respectively.The SKOV3 group, SKOV3NS group, and SKOV3siRNA group in STAT3 protein expression was significantly lower and the differences were statistically significant(P0.05).Conclusion:The STAT3 specific shRNA expression vector could effectively suppress the expression level of STAT3 gene in SKOV3 cells as well as enhance their sensitivity to cisplatin.