Background and purpose: Multidrug resistance (MDR) of tumor cell is the main reason for clinical chemotherapy failure as well as cancer recurrence and metastasis. This study was to construct a lentiveral vector of RNA interference of MDR1 gene and observe its inhibitive role on the expression of MDR1 in A549 and A549/DDP cells. Methods: Oligos of base pairs for hairpin RNA targeting MDR1 were chemically synthesized. Via annealing and inserting them into the down-stream of H1 promoter of linearized pSUPER, we obtained the siRNA constructs for MDR1, which were afterwards transfected into A549, a human lung cancer cell line expressing high level MDR1, the impact of constructs was observed on the expression and interference efficiency of siRNA against MDR1. The effective sequence of siRNA targeting MDR1 gene was confirmed. Both sense and antisence oligo DNA of the targeting sequence was designed, synthesized and cloned into the PTM vector, containing a promoter and a green fluorescent protein (GFP). The resulting lentiviral vector containing MDR1 siRNA was named PTM-siMDR1 and then transfected into A549 and A549/DDP cells after being confirmed by PCR and sequencing. Results: Restriction digestion and DNA sequencing showed that the siRNA constructs for MDR1 were successfully produced and the expressed siRNA could effectively down-regnlate the expression of MDRI. PCR demonstrated that the lentivirus RNAi vector of MDR1 producing PTM-siMDR1 was constructed successfully. The chemosensitivity of A549/DDP cells to cisplatin were enhanced obviously after trartsfection. Conclusion: The lentivirus RNAi vector of MDR1 can significantly revise the resistance ofA549/ DDP cells with eisplatin after infection.

BACKGROUND: A great quantity of cell loss in early stage following stem cell transplantation can significantly affect transplantation effect. Presently, it is confirmed that overexpression of AKT1 gene significantly inhibit cell apoptosis. OBJECTIVE: To explore whether AKT1 gene overexpression can block stem cell apoptosis under hypoxic condition following pig autologous bone marrow mesenchymal stem cell (BMSC) transplantation, and the effect of repairing damaged myocardium. DESIGN, TIME AND SETTING: The randomized controlled animal study was performed at the Soochow University from August 2005 to February 2007.MATERIALS: A total of 24 healthy male Meishan pigs were supplied by the Animal Experimental Center of Soochow University. METHODS: The CDS (regulation domin of AKT1) AKT1-cDNA fragment was amplified. Lentivector Packaging Kit was used to transfect BMSCs after synthesized with pCDH1-AKT1 shuttling plasmid. Following BrdU labeling, models of myocardial infarction were constructed by occluding the distal left anterior descending coronary artery in pigs with gelatin sponge. 4 weeks later, pigs were randomly divided into four groups: the model control group, the DMEM group, the BMSCs group, and the AKT-transfected group. In model control group, there was no other injection after occluding the left anterior descending coronary artery. In the DMEM group, 5 mL DMEM was injected into the coronary artery. 5 mL BMSCs (1×10~7 cells) were infused into the coronary artery in the BMSCs group. 5 mL BMSCs transfected with the AKT1 gene were injected in the AKT-transfected group MAIN OUTCOME MEASURES: Western blot analysis and real time RT-PCR were used to test the plasmid. The cardiac function was evaluated by magnetic resonance image. Histological characteristics of the myocardium were observed using immunohistochemistry. Serum vascular endothelial growth factor and transforming growth factor β1 levels were determined by ELISA. RESULTS: AKT1-cDNA was cloned into pCDH1-MCS1-EF1-copGFP and the sequence was confirmed in comparison with the published one. AKT mRNA expression could be detected distinctly 24 and 48 hours after transfecting cells. The expression of AKT1 intensity in MSCs remained strong 2 weeks later with detected by real time RT-PCR and Western blot analysis. AKT1-mRNA transcriptional levels were 120 times of primary cells. Before the cell implantation, the left ventricular end-diastolic dimension increased and the stroke volume decreased in the myocardial infarction hearts. The cardiac function was significantly improved after cell implantation, and the implanted MSCs prevented the infarct region from thinning and expanding, improved contraction and increased perfusion in all groups relative to the control hearts. The left ventricular chamber size was smaller in the hearts with being transplanted cells than that in the control hearts. Moreover, the improvement was even markedly greater in AKT-transfected group (P < 0.05). Hematoxylin-eosin staining results showed that fibering was significant in the model control group and DMEM group. Island-like myocardium was observed in the infarct zone of the BMSCs group and AKT-transfected group, and plenty of small vessels-shape structure was detected in the AKT-transfected group. Immunohistochemistry demonstrated that Von Willebrand Factor (vWF) and Cx-43 expression was determined in the myocardium in the BMSCs group and AKT-transfected group, and the proportion of BrdU and Cx-43-positive cells to BrdU-positive cells was significantly greater in the AKT-transfected group compared with the BMSCs group 4 weeks following transplantation (P < 0.05). Following cell transplantation, vascular endothelial growth factor levels were gradually increased, peaked at 1 week, gradually decreased, and reached a normal level at 4 weeks. Transforming growth factor p1 levels were gradually reduced, and significantly less than the model control group, DMEM group 4 weeks later (P < 0.05), and significantly lower than that pretransplantation (P < 0.05).CONCLUSION: Using lentiviral vector to construct with AKT1 gene could stably make BMSCs overexpress AKT1. The BMSCs engraftment in host myocardium might improve the left ventricle function by attenuating the contractile dysfunction and pathologic thinning in this model of left ventricular wall infarction. AKT1 overexpression can significantly improve cardiac function following infarction.

Background and Objectives: Circulating endothelial progenitor cells (EPCs) participate in vascular repair and predict cardiovascular outcomes. The aim of this study was to investigate the correlation between EPCs and abdominal aortic aneurysms (AAAs). Methods: and Results: Patients (age 67±9.41 years) suffering from AAAs (aortic diameters 58.09±11.24 mm) were prospectively enrolled in this study. All patients received endovascular aneurysm repair (EVAR). Blood samples were taken preoperatively and 14 days after surgery from patients with aortic aneurysms. Samples were also obtained from age-matched control subjects. Circulating EPCs were defined as those cells that were double positive for CD34 and CD309. Rat models of AAA formation were generated by the peri-adventitial elastase application of either saline solution (control; n=10), or porcine pancreatic elastase (PPE; n=14). The aortas were analyzed using an ultrasonic video system and immunohistochemistry. The levels of CD34＋/CD309＋ cells in the peripheral blood mononuclear cell populations were measured by flow cytometry. The baseline numbers of circulating EPCs (CD34＋/CD309＋) in the peripheral blood were significantly smaller in AAA patients compared with control subjects. The number of EPCs doubled by the 14th day after EVAR. A total of 78.57% of rats in the PPE group (11/14) formed AAAs (dilation ratio ＞150%). The numbers of EPCs from defined AAA rats were significantly decreased compared with the control group. Conclusions EPC levels may be useful for monitoring abdominal aorta aneurysms and rise after EVAR in patients with aortic aneurysms, and might contribute to the rapid endothelialization of vessels.

Islet β cell dedifferentiation is one of the important reasons leading to insulin secretion defect or insulin resistance in patients with type 2 diabetes mellitus(T2DM).HIF-1α/PFKFB3 signaling pathway is a newly discovered biological pathway related to T2DM,which is involved in the induction of islet β cells dedifferentiation by anaerobic glycolysis under high glucose environment.This article reviews the research progress of the role of HIF-1α/PFKFB3 signaling pathway in glycolysis induced islet β cell dedifferentiation.

Objective:To establish an in vitro capsular bag model and compare the inhibitory effects of different 360° square-edge intraocular lens (IOL) on lens epithelial cells (LECs) migration. Methods:In vitro capsular bag model with posterior capsule opacification (PCO) was established using Transwell compartment, cell climbing slices, human collagen type Ⅳ, and IOL.The models were divided into Plate-loop HydroSmart group, C-loop HydroSmart group, and C-compensation-loop Hydrophobic group according to the different square-edge IOL implanted.A blank control group was set using the Transwell compartment without IOL.The early PCO pathological manifestations in lens epithelial cell line SRA01/04 cultured in the Transwell compartment were observed with an inverted microscope.The cell morphology in different groups was observed by hematoxylin and eosin staining.The cell counting and cell migration inhibition rate of anterior capsule and posterior capsule were calculated by Transwell assay and cell-exclusion zone assay, respectively. Results:The early pathological characteristics of PCO, such as early Soemmering ring and small Elschnig pearl, could be found in cells in the in vitro capsular bag model after 48-hour culture.The migrating cells in model groups were fibrous.No changes mentioned above were found in blank control group.The number of migrating cells in the anterior capsule of Plate-loop HydroSmart group, C-loop HydroSmart group, C-compensation-loop Hydrophobic group was 18.80±5.53, 24.67±9.80, and 34.47±10.80, respectively, and the number of migrating cells in the optical area of the posterior capsule of the three groups was 56.43±9.00, 162.20±16.38, and 121.30±12.01, respectively.The cell migration inhibition rate in the anterior capsule of Plate-loop HydroSmart group, C-loop HydroSmart group, C-compensation-loop Hydrophobic group was (92.02±1.94)%, (89.76±3.10)%, (86.27±4.54)%, respectively, and the cell migration inhibition rate in optical area of the posterior capsule of the three groups was (91.60±3.65)%, (70.14±5.35)%, (78.43±3.48)%, respectively.The number of migrating cells in the anterior capsule was lower and the cell migration rate inhibition was higher in Plate-loop HydroSmart group than C-compensation-loop Hydrophobic group, with significant differences (both at P<0.05). The number of migrating cells in the optical area of the posterior capsule and the cell migration inhibition rate was greater than those of C-loop HydroSmart group and C-compensation-loop Hydrophobic group, showing statistically significant differences (all at P<0.001). Conclusions:The in vitro capsular bag model can be used in PCO research.Compared with C-loop HydroSmart IOL and C-compensation-loop Hydrophobic IOL, Plate-loop HydroSmart IOL can more effectively inhibit the migration of LECs to the optical area of the posterior capsule.