ABSTRACT
Objective To investigate the protective mechanism of MEK1/2 inhibitor PD98059 on ox-LDL induced injury of human umbilical vein endothelial cells (HUVEC),and its influence on the expression of LOX-1.Methods HUVEC damage models were established by using ox-LDL and were treated with PD98059 later,divided into the negative control group,the ox-LDL group,the positive control group and the PD98059+ox-LDL group.The effect of inhibition of MEK1/2 on ox-LDL induced HUVEC damage was measured.Results Compared with the negative control group,the levels in the ox-LDL group of LOX-1,pMEK1/2,RhoA,ROCK1,ROCK2,TNF-α and IL-6 were increased significantly,the proliferations of HUVEC and the productions of NO were decreased (P＜0.05).Compared with the ox-LDL group,the levels in the positive control group and the PD98059+ox-LDL group of pMEK1/2,RhoA,ROCK1,ROCK2,TNF-α and IL-6 were decreased,the proliferation of HUVEC and the production of NO were increased (P＜0.05).Conclusion PD98059 inhibit the MEK1/2 signaling pathway to suppress the ox-LDL induced damage of HUVEC by decreasing the expression of LOX-1.
ABSTRACT
Objective To construct the KU80 inhibition cell model by RNAi in U2OS cell and to explore the relationship between the Ku80,telomeres and radiosensitivity in telomerase-negative tumor cells.Methods U2OS cells were transfected with the recombinant plasmids of pshRNA-K80 by the lipofectamine,and the stable transfected cell clones were selected by G418.After the selection,the cells were collected and analyzed by the flow cytometry.RT-PCR and Western blot were used to measure the expression of Ku80 and Real-time PCR was used to detect the length of telomeres.The radiosensitivity of U2OS was determined by clone formation array.Results The transfection efficiency of the positive cell clones detected by the flow cytometry was (83.23 ± 7.63) ％.The inhibition rate of the Ku80 gene transcription in the cell group with recombinant plasmid was(68.09 ± 1.16)％ and the inhibition rate of the Ku80 protein expression in the same group was (11.03 ± 2.45) ％.The results of Real-time PCR showed that the telomere length of the cell group with recombinant plasmid (1.07 ± 0.07) was significantly shorter than that of the control group (4.42 ± 1.30,F =38.58,P ＜ 0.05) and that of the empty plasmid group (4.11 ±0.84,F =38.58,P ＜ 0.05).Compared to the control group,the telomere length of the empty plasmid group did not changed(4.42 ±0.84 vs.4.11 ±0.84).U2OS cells with Ku80 expression suppressed had lower SF2 than that of the control cells (F =1089.61,P ＜0.05),and resulted in the SER of 1.47.Conclusions The Ku80 inhibition cell model in telomerase-negative U2OS cell line is successfully established which has the shorter telomere length,and is more sensitive to radiation.Telomere shortening caused by pshRNA-of Ku80 is likely to be one of the mechanisms of radiosensitization in this kind of cell model.
ABSTRACT
Clinical studies confirm that postoperative adjuvant chemotherapy could significantly reduce mortality rate of patients with the operable breast cancer and improve surviral rate. At present, adjuvant chemotherapy of breast cancer is developing for the direction of high specificity, more efficiency and low toxicity. Individualized and standardized comprehensive treatment which based on molecular genetic analysis is the direction of adjuvant chemotherapy of breast cancer.