ABSTRACT
<p><b>OBJECTIVE</b>To investigate the biological behaviors and chemosensitivity of non-small cell lung cancer (NSCLC) cell line A549 after IGF-IR gene silencing by RNA interference (RNAi) in vitro.</p><p><b>METHODS</b>Two plasmids siRNA 1 and 2 expressing IGF-IR siRNA with human U6 promoter were constructed,and an unrelated siRNA was used as negative control. NSCLC A549 cells were transfected with sequence-specific siRNA or unrelated siRNA as control. Quantitative RT-PCR and Western blot were used to detect the expression of IGF-IR. NSCLC A549 cells were transfected with siRNA and treated with DDP. MTT assay and flow cytometry were used to assess the effects of IGF-IR silencing on tumor cell proliferation and chemosensitivity.</p><p><b>RESULT</b>Transfection of NSCLC cells with siRNA resulted in reduction of IGF-IR mRNA expression by 78.9 % and protein production by 89.8%. The decrease in IGF-IR levels caused significant growth inhibition of A549 cells both at 48 h and at 72 h, and decrease of the IC50 of DDP at 24 h, 48 h and at 72 h. Flow cytometry showed that 77.5% of A549 cells retained in G0/G1 phase.</p><p><b>CONCLUSION</b>The sequence specific suppression of IGF-IR gene expression by RNAi enhances sensitivity to DDP in NSCLC cell.</p>
Subject(s)
Humans , Carcinoma, Non-Small-Cell Lung , Genetics , Metabolism , Pathology , Cell Line, Tumor , Cell Proliferation , Gene Silencing , Lung Neoplasms , Genetics , Metabolism , Pathology , Plasmids , Genetics , RNA Interference , RNA, Messenger , Metabolism , RNA, Small Interfering , Genetics , Receptor, IGF Type 1 , Metabolism , TransfectionABSTRACT
Objective To evaluate the protective effect of aminophylline on myocardium in the patients undergoing prothetic valve replacement operation of heart.Mothods Thirty patients undergoing prothetic valve replacement operation of heart were randomized to be treated either with aminophylline(n=15)or without aminophylline treatment(n=15). Aminophylline(5mg/kg)was injected intravenously at 15 minutes after induction of anesthesia.Cardiac troponin I(cTnI), cyclic adenosine monophosphate(cAMP),myeloperoxidase(MPO),ratio of aortic blood neutrophil count to coronary vein sinus blood neutrophil count,hemodynamics,time of aortic cress-clamping and other clinical data were recorded during the operation.Results There were no differences between the two groups in the major perioperative variables.Plasm cTnI concentration in both groups increased after off-clamping than that before CPB,however,it was lower in aminophylline group than that in control group.Concentration of cAMP in both groups after off-clamping was lower than that before CPB, however cAMP concentration in aminophylline group after off-clamping was higher than that in control group.Myocardial MPO activity and neutrophil count ratio after aortic off-clamping in aminophylline group was significantly lower than that in control group.Conclusion These results suggest that aminophylline is helpful to unprotection of myocardial and decreases the sequestration of neutrophil in myocardium.The mechanism of the protection may be related to the cAMP increased in myocardium.