Objective To study the effect of neuroepithelial cell transforming gene 1 (Net1) on the cellular radiosensitivity and underlying mechanism.Methods Real-time quantitative PCR was used to measure the variations in Net1 expression level upon irradiation.Radiosensitivity was analyzed by colonyforming assay after Net1-siRNAs.Net1-associated proteins were identified by co-immunoprecipitation.Results The Net1 mRNA level in the cells was increased significantly (t =-10.52,P ＜ 0.05) after irradiation.Compared to the control group,siRNA-mediated silencing of Net1 enhanced cell radiosensitivity (t =15.31,11.65,P ＜0.05).Net1 was found to interact with Ku70,Ku80 and DNA-PKcs under either normal conditions or after irradiation.Conclusions Net1 could protect cells from irradiation by interaction with DNA repair proteins in non-homologous end joining pathway.

Objective To investigate the effect of thrombin and hemoglobin on aquaporin (AQP) and the correlation between AQP and hydrocephalus.Methods Eighty-four clean grade healthy male SD rats were randomly divided into 3 groups:a control group,a thrombin group,and a hemoglobin group using the random number table method.A hydrocephalus model was induced by injecting isotonic saline (0.3 ml),thrombin (0.3 ml[10,U/ml]) and hemoglobin (0.3 ml[150 mg/ml]),respectively into the cisterna magna.According to the deficiency and complement way,each group maintained 24 rats.The relative area of the lateral ventricles,the expression of AQP1 and AQP4,and the correlation between AQP and the area of the lateral ventricles were observed at 1,3,7,and 14 d after molding.Results (1) Compared with the control group,both the thrombin group and hemoglobin group showed hydrocephalus at 1 ,3 ,7 and 14 d,and they were most obvious at 1 day (6.94±0.19% and 6.58±0.15% vs.3.40±0.13%,6.06±0.12% and 5.79±0.09% vs.3.55±0.15%,5.80±0.13% and 5.58±0.08% vs.3.78±0.18%,5.66±0.14% and 5.47±0.13% vs.3.52±0.18 %,respectively).There were significant differences (all P<0.01).(2) The increase of AQP1 was mainly in the basal membrane and apical membrane of ventricular choroid plexus epithelial cells,and the increase of AQP4 was mainly in the ependymal cell of ventricle.The relative expression levels of AQP1 and AQP4 at 1,3,7,and 14 d in the control group were 1.09±0.07 and 1.30±0.15,0.91±0.06 and 1.18±0.12,1.33±0.17 and 1.16±0.08,1.22±0.11 and 1.00±0.10,respectively;the thrombin group were 4.40±0.14 and 3.69±0.11,3.88±0.11 and 3.17±0.07,3.55±0.07 and 2.86±0.13,and 3.36±0.07 and 2.70±0.07,respectively,the hemoglobin group were 4.24±0.07 and 3.55±0.10,3.77±0.08 and 3.04±0.09,3.46±0.07 and 2.76±0.08,and 3.31±0.10 and 2.62±0.08,respectively;the relative expression levels of AQP1 and AQP4 of the thrombin group and hemoglobin group at each time point were significantly higher than those of the control group.There were significant differences among the groups (all P<0.01).There were no significant differences in the relative expression levels of AQP1 and AQP4 mRNAs in the hemoglobin group at each time point (P>0.05);in the thrombin group and hemoglobin group,compared with those at 1 d,the expression levels of AQP1 and AQP4 at 3,7,and 14 d were significantly decreased (all P<0.01);compared with those at 3 d,AQP1 was decreased significantly at 7 and 14 d (P<0.05).The differences were statistically significant (P<0.05).(3) The relative expression levels of AQP1 (r=0.983,P<0.01) and AQP4 (r=0.987,P<0.01) in the thrombin group at each time point were positively correlated with the contralateral ventricular area;and the relative expression levels of AQP1 (r=0.964,P<0.01) and AQP4 (r=0.962,P<0.01) in the hemoglobin group at each time point were positively correlated with the contralateral ventricular area Conclusions After injecting thrombin and hemoglobin into subarachnoid space,it could cause the increased expression levels of AQP1 and AQP4 of ventricles and their surrounding areas.Thrombin and hemoglobin may be the important mediating factors of hydrocephalus after subarachnoid hemorrhage.

BACKGROUNDLung carcinoma is one of the most common malignant tumors in China.The increasing incidence of lung cancer has been alerted and multimodality treatments including surgery,radiotherapy,chemotherapy etc.have been highly aware.However,the outcome of treatment in lung cancer remains poor,because there is still no definite molecular targeting drug affecting its biological behavior significantly.To find an useful clinical tool,the aims of this study are to explore the effects of a novel monoclonal antibody targeting at the α-strain of insulin-like growth factor 1 receptor(IGF1-αR) on lung adenocarcinoma cell lines.

METHODSThe novel monoclonal antibody targeting at IGF1-αR was exacted by hybrid cell processes and purified by Protein G column.The effects of growth were investigated on SPCA-1 and A549 cell lines by MTT curve lines and the expression of Ki67.

RESULTSThe combination of IGF1 with IGF1-αR could be competitively inhibited by the novel monoclonal antibody significantly.Intervented by the novel monoclonal antibody,SPCA-1 and A549 cell lines proliferated more slowly than that of the respective control,with significant statistic value(P < 0.05).Besides,the expression of Ki67 showed significant downregulation under the invention of the monoclonal antibody.

CONCLUSIONSThe special monoclonal antibody extracted in our laboratory shows good affinity with IGF1-αR,and can inhibit the growth of SPCA-1 and A549 cell lines.

Objective To investigate the effects of soothing liver and activating blood Chinese medicine on myocardial cell apoptosis and related gene expression of BMSCs transplanting on myocardial ischemia reperfusion injury (IRI) of rats;To discuss its mechanism of protecting myocardium. Methods Model of myocardial IRI was established in rats. BMSCs were isolated, cultivated, and transplanted in IRI rats. SD rats were randomly divided into sham-operation group, IRI group, BMSCs group, and combined group. Rats in combined group received gavage with soothing liver and activating blood Chinese medicine, while rats in other groups received gavage with the same dose of normal saline. After 4 weeks, myocardial cell apoptosis, Bcl-2, and Bax protein expression in myocardial cells were detected by TUNEL method and immunohistochemical method. Results Compared with IRI group, myocardial cell apoptosis index in the combined group and BMSCs group was lower, Bax expression decreased, Bcl-2 expression significantly increased (P<0.01);Compared with BMSCs group, myocardial cell apoptosis index in the combined group was lower;Bax expression decreased, Bcl-2 expression increased (P<0.05, P<0.01). Conclusion Soothing liver and activating blood Chinese medicine can inhibit BMSCs transplantation in IRI rat myocardial cell apoptosis, promote myocardial regeneration, and protect myocardial cells.

Objective To evaluate the correlation between homologous recombination repair protein RAD51 and methotrexate-enhanced radiosensitivity.Methods Western blot and RT-PCR assays were used to detect RAD51 expression in HOS osteosarcoma cells exposed to γ-ray irradiation alone and in combination with methotrexate.Colony formation assay was used to test the survival fraction of HOS cells exposed to γ-rays and methotrexate.Results Methotrexate inhibited both protein and RNA expressions of RAD51,and the combination of radiation and methotrexate enhanced the inhibition of RAD51 expression.Moreover,transfection of cells with RAD51 gene decreased cellular sensitivity to methotrexate and γ-rays.The sensitizer enhancerment ratios after irradiation in combination with methotrexate were 1.51 and 0.99,respectively.Methotrenate was a preferred radiosensitizer to HOS cell.Conclusions RAD51 might be involved in the methotrexate-enhanced radiosensitivity.

Objective To explore the lethal action and possible mechanism of RI-1, a RAD51 inhibitor, on MSH2 deficient colorectal cancer cells.Methods The expression of MSH2 protein level was assessed by Western blot, and the sensibility of human colorectal cancer cells to RI-1 (10, 20, 30, 40 and 50 μmol/L)was measured by MTT method.Lentivirus vectors MSH2-shRNA and Neg-shRNA (negative control) were constructed and transfected into HT29 cell.Apoptosis and DNA damage of cells treated with RI-1(40 μmol/L)were detected by flow cytometry and Single cell gel electrophoresis respectively.In addition, the formation of γ-H2AX foci was analyzed by immunofluorescence.Results Compared with control, MSH2-deficient HCT8 cells had obviously apoptosis(P<0.01);in HCT8 and HT29 Shmsh2 cells, tail DNA%, tail length, tail moment and olive tail moment were markedly increased(P<0.05),and the number of γ-H2AX focus were increased(P<0.01).Conclusions RAD51 inhibitor RI-1 selectively kills MSH2 deficient colorectal cancer cells by increasing DNA damage.

Objective To explore the feasibility of high-frequency ultrasound detecting median nerve (MN) in type 2 diabetes mellitus(T2DM)with diabetic peripheral neuropathy(DPN).Methods Forty-two healthy volunteers were included as control group(Group A).Eighty-eight T2DM patients were divided into two groups according to symptoms,signs and electrophysiological results:with DPN (group C,46 patients) and without DPN (Group B,42 patients).The width(W),thickness(T) and cross-sectional area(CSA) of MN at 6 points [the wrist crease,pisiform bone,hamate bone,the 6 cm proximal to the wrist crease,the 4 cm proximal to tip of the medial epicondyle(ME) and the midpoint of the humerus] were evaluated.ROC curve was plotted to determine clinical diagnostic value of three lines on six points in diagnosis of DPN. Results ①Comparing with Group A,the width(P <0.05) except for the 4 cm proximal to tip of ME and the midpoint of the humerus,the thickness (P <0.05) except for the 4 cm distal to ME and CSAs of all points were enlarged in DPN patients(P <0.001).The width(P <0.05)at the wrist crease,hamate bone and the midpoint of the humerus,the thickness (P <0.01) at the wrist crease and pisiform bone,CSAs (P <0.01) of all sites except for the wrist crease were increased in Group B.Comparing Group B with C, the width at the wrist crease,the thickness in the midpoint of the humerus,CSAs except for the 4 cm proximal to ME and the midpoint of the humerus were dramaticlly increased in Group C(P <0.001).②A diagnostic value comparison:when diagnostic value of W,T and CSA at six points is the most predictive, the sensitivity is 80.4%,84.8%,84.8% respectively and specificities are all 54.8%.Diagnostic value of CSA and T is superior to the width.The CSA and T of the hamate bone level were the most predictive of DPN.The corresponding optimal cut-off value was 0.097 cm 2 ,0.233 cm respectively.Conclusions The backbone and the abnormal changes of different lines of the MN in DPN can be observed by high-frequency ultrasound.The width and thickness of the MN at six points are increased in different degree,but CSAs of all levels can enlarge.When diagnostic value of W,T and CSA at six points is the most predictive for DPN, the sensitivity is superior to specificity respectively.The CSA and T of the hamate bone levelare the most predictive for the evaluation of DPN.

BACKGROUND:Tissue-engineered bone scaffold fabricated by 3D-bioprinting technique has good controlability in morphology and structure. However, construction of tissue-engineered bone/cel growth factor complex and time-dose effect of sustained-release factors are needed to be further researched.
OBJECTIVE:To fabricate a sustained-release composite of polylactic-co-glycolic acid (PLGA)/nano-hydroxyapatite (n-HA) scaffold carrying bone morphogenetic protein-2 (BMP-2) using 3D-bioprinting technique, and test the biological properties of the PLGA/n-HA scaffold carrying BMP-2 and the sustained-release properties, thereby to discuss its feasibility as the tissue-engineered bone scaffold composite.
METHODS:Temperature-sensitive chitosan hydrogel was prepared using chitosan andβ-glycerophosphate to construct a sustained-release composite, chitosan nanoparticles carrying BMP-2 . 3D-bioprinting technique was utilized to fabricate the PLGA/n-HA scaffold carrying BMP-2. Biological features of the scaffold composite were tested, and time-dose effect of BMP-2 sustained-release was observed.
RESULTS AND CONCLUSION:The average pore size of the scaffold-cytokine composite was (431.31±18.40)μm, and the porosity was (73.64±1.82)%. The cumulative release rate of BMP-2 from the scaffold-cytokine composite that effectively controled the burst release during 48 hours and 30 days were suitable for the physiological needs. In conclusion, the porosity, pore size, release property, degradation rate, and mechanical strength of the scaffold-cytokine composite al meet the biological requirements of tissue-engineered bone construction.

Objective To study the curative effect of XRCC2 gene silencing mediated by shRNA combined with radiation on human colonic trans?planted carcinoma in nude mice. Methods Colonic carcinoma T84 cells were transfered into BALB/c nude mice to establish a tumor xenograft mod?el in vivo. Mice were divided into three groups:control,shRNA?SC and shRNA?XRCC2 and exposed to X?ray radiation. The change of volume and weight of the xenografts were examined after receiving radiotherapy and the pathological analysis of tumor tissues were conducted. Results Tumor xenografts transfected with shRNA?XRCC2 in nude mice grew slowly. The xenograft volume in the shRNA?XRCC2 group was decreased significant?ly from day 12 to day 28 after radiotherapy compared with the control group(P<0.01). The xenograft weight in the shRNA?XRCC2 group was small?er than in the control group,with statistically significant difference(t=18.843,P<0.01). The inhibited rate of xenografts in the shRNA?XRCC2 group(56.25%),was markedly higher than that in the shRNA?SC group(4.69%). Pathological analysis of colonic transplanted carcinoma showed that nuclear atypia was not obvious,karyokinesis was decreased and small areas of necrosis were present in tumor xenografts treated with shRNA?XRCC2 transfection. Conclusion XRCC2 gene silencing combined with radiation has significant inhibition effect on colonic transplanted carcino?ma in nude mice.

Hematopoietic stem cell ( HSCs) injury induced by ionizing radiation ( IR) is the primary cause of death after exposure to ionizing radiation .The mechanisms of inducing HSCs damage include induction of HSCs apoptosis via the P53-Puma pathway;promotion of HSCs differentiation via the activation of the G-CSF/Stat3/BATF-depend-ent differentiation checkpoint;induction of HSCs senescence via the ROS-P38 pathway; and damage to the HSCs niche.Recent researches provide a basis for the prevention and treatment of bone marrow suppression caused by ionizing radiation .