Objective:To investigate the inhibitory effect of RNA interference (RNAi) on the expression of multidrug resistance (MDR1) gene and analyze the altered sensitivities of human renal carcinoma cell line to cisplatin.Methods:Three small interfering RNA (siRNA) sequences targeted MDR1 gene were synthesized and transfected into renal carcinoma A498 cells. The expression level of MDRl mRNA was measured by RT-PCR to identify the most effective siRNA sequence. The recombinant plasmid was packed by lentivirus and transfected into A498 cells. RT-PCR was used to screen the A498 cells with the optimal silencing efficacy. The MDR1 protein expression level in the cloned cells was verified by Western blotting. The inhibitory effect of cisplatin on the proliferation of A498 cells was assessed by MTT assay and the IC_(50) value was calculated. Results:The 3 siRNA sequences suppressed MDR1 gene expression at different degrees. The siRNA 1 sequence silenced MDR1 gene more effectively with a significant reduction of 67%. The MDR1 protein expression greatly decreased in screened A498 cells compared with non-transfected cells (P<0.01), and the IC_(50) value of cisplatin on screened A498 cells was significantly decreased by 83.37% (P<0.01). Conclusion: The RNAi could effectively inhibit the expression of MDR1 gene and increase the sensibility to cisplatin in human renal carcinoma A498 cell line, which make it possible to reverse the resistance of renal carcinoma to chemotherapy.

Objective To investigate whether thalidomide inhibits the over expression of type I collagen in pulmonary fibrosis rats via inhibiting the JNK signaling pathway,thereby reducing bleomycin induced pulmonary interstitial fibrosis in rats.Methods 90 healthy male SD rats were randomly divided into normal control group (group N),model group (group M),thalidomide group (group T),SP600125 group (group SP) and thalidomide+SP600125 group (group T+SP).The pulmonary fibrosis models were prepared via intratracheal injection of 5mg/kg bleomycin,and rats in groups were given corresponding drugs from the first day after preparing model.Rats were randomly sacrificed at 7,14 and 28 days after treatment.The degree of pulmonary alveolitis and fibrosis was evaluated by H&E and trichrome masson stainings.The level of hydroxyproline in the lung tissue was detected by applying alkaline hydrolysis technique,and expression levels of p-JNK and type I collagen were tested by Western bloting for protein expression and real-time polymerase chain reaction (RT-PCR) for mRNA expression.Results In group M,alveolitis was the most serious on day 7; a marked pulmonary fibrosis formed on day 28; the level of hydroxyproline also peaked on day 28,and the contents of p-JNK and type I collagen were higher than in group N(F=277.87,472.51,both P＜ 0.01).Group T,SP and T+SP showed mild alveolitis and fibrosis at all time points,and their levels of hydroxyproline,p-JNK and type I collagen were remarkably decreased as compared with group M (F=14.77,61.59,101.73,all P＜0.01;F=10.33、79.12、57.48,all P＜0.01).No significant difference in p JNK was found between group SP and group T+SP.Conclusions Thalidomide may inhibit the over expression of type I collagen in pulmonary fibrosis rats via inhibiting the JNK signaling pathway,thereby reducing bleomycin induced pulmonary interstitial fibrosis in rats.

Objective To understand the present internet addition of Chinese college students and to explore the relationship between the types of internet addition and learning burnout,and to provide reference and theoretical basis for domestic research on internet addition.Methods Two-stage stratified sampling was used to select 1 485 students in Grade one to Grade three from seven colleges and universities in Henan province including Xinxiang Medical University,Sanquan College of Xinxiang Medical University,Xinxiang University,Henan Institute of Science and Technology,Henan Normal University,Henan University of Technology,Engineering College of Zhengzhou University.The university students questionnaire of internet addiction types and the leaning burnout scale were used and the results were analyzed.The students with internet addiction were divided into high score group and low score group according to result of questionnaire of intemet addiction types,and the difference of learning burnout between them was analyzed.Results In the types of internet addiction,the leaning burnout scores and the score of each dimensional scores in the high score group were significantly higher than those in the low score group (P ＜ 0.01).The network game addiction scores was positively related to depression,misconduct and learning burnout(P ＜ 0.05,P ＜ 0.01);questionnaire of network information scores and depression had positive correlation (P ＜ 0.05).Conclusion The tendency of network information addiction is higher,the manifestation of depression is more obvious.The more obvious tendency of network information addiction,network relationship addiction,network information addition,which more easily leads to learning burnout.

D-lactonohydrolase is useful in the procedure of resolution of racemic pantolactone to produce D-pantolactone, but the activity and stability under low pH of the wild type enzyme is not satisfactory enough to be applied to industrial production. The expected properties of wild type enzyme were enhanced by directed evolution. According to the formation of products and pH indicators, a screening system was designed. After three sequential error prone PCR and one round DNA shuffling followed by screening, Mut E-861, the best mutant with improved activity and stability under low pH situation was obtained. Gene analysis of the Mut E-861 mutant indicated that the mutant enzyme had A352C, G721A mutations and a silent mutation of position 1038. Moreover, the activity and stability of Mut E-861 were determined. The results showed that the activity of this mutant was 5.5-fold higher than that of wild type, and the stability under low pH was improved at no expense of D-lactonohydrolase activity. After incubated at pH 6.0 and pH 5.0 the activity of D-lactonohydrolase could be retained 75% to 50%, however, compared with 40% to 20% for wild type.
Carboxylic Ester Hydrolases ; biosynthesis ; genetics ; DNA Shuffling ; Directed Molecular Evolution ; Enzyme Stability ; Escherichia coli ; enzymology ; genetics ; Mutagenesis, Site-Directed ; Mutant Proteins ; genetics ; metabolism ; Polymerase Chain Reaction ; methods ; Protein Engineering ; Saccharomyces cerevisiae ; enzymology ; genetics

Objective: To explore determinants of childhood trauma among college students with left-behind experience, and to provide a reference for effective intervention among students with left-behind experience. Methods: A total of 2 468 students selected from 5 universities and 2 higher vocational colleges in tianjin by stratified cluster sampling method were investigated by self-compiled questionnaire and childhood trauma questionnaire. Results: The scores in emotional abuse, sexual abuse, emotional neglect, physical neglect and childhood trauma of students with left-behind experience were significantly higher than those without left-behind experience(t=3.01，3.13，3.24，2.27，3.60，P<0.05)；parental separation times and the frequency of parental return had significant interaction effect on the total score of childhood trauma of students with left-behind experience (F=2.37, P<0.05)；the gender had a significant major effect on the total score of childhood trauma of students with left-behind experience under the interaction with the place of origin, age at first separation,the cumulative time of leftbehind experiences and the frequency of parents contacting (F=4.49，5.23，5.93，5.11，P<0.05)；the age of subjects when parents going out under the interaction with the place of origin, the gender, if only-child,parental separation times and the frequency of parental return；as well as the frequency of parents contacting under the interaction with the place of origin，the household registration, the gender, if only-child and the cumulative time of left-behind experiences also had significantly main effect(F=3.88，4.25，3.32，2.86，3.45；3.82，4.02，2.64，3.29，P<0.05). Conclusion It is necessary to attach great importance to demographic and context information regarding left-behind experiences,which lead to more specific and effective prevention and intervention strategy for individual with left-behind experiences.

OBJECTIVETo monitor the systemic gene expression profile in a murine model of lipopolysaccharide-induced acute lung injury.

METHODSAcute lung injury was induced by intratracheal injection of lipopolysaccharide in 3 mice. Another 3 normal mice receiving same volume of normal saline were taken as the controls. The comprehensive gene expression profile was monitored by the recently modified long serial analysis of gene expression.

RESULTSA total of 24,670 tags representing 12,168 transcripts in the control mice and 26,378 tags representing 13,397 transcripts in the mice with lung injury were identified respectively. There were 11 transcripts increasing and 7 transcripts decreasing more than 10 folds in the lipopolysaccharide-treated mice. The most overexpressed genes in the mice with lung injury included serum amyloid A3, metallothionein 2, lipocalin 2, cyclin-dependent kinase inhibitor 1A, lactate dehydrogenase 1, melatonin receptor, S100 calcium-binding protein A9, natriuretic peptide precursor, etc. Mitogen activated protein kinase 3, serum albumin, complement component 1 inhibitor, and ATP synthase were underexpressed in the lung injury mice.

CONCLUSIONSSerial analysis of gene expression provides a molecular characteristic of acute lung injury.

Animals ; Cyclin-Dependent Kinases ; antagonists & inhibitors ; blood ; DNA-Binding Proteins ; blood ; Disease Models, Animal ; Gene Expression ; genetics ; Gene Expression Profiling ; methods ; Lipopolysaccharides ; Male ; Metallothionein ; blood ; Mice ; Mice, Inbred C57BL ; Neoplasm Proteins ; blood ; Nuclear Proteins ; blood ; Protein Folding ; Reference Values ; Respiratory Distress Syndrome, Adult ; chemically induced ; genetics ; S100 Proteins ; blood ; Serum Amyloid A Protein ; metabolism

OBJECTIVETo establish a tumor-bearing nude mouse model of human neuroblastoma in order to study the mechanisms of neuroblastoma invasion and metastasis, and to investigate potential therapeutic modalities in the experimental animal models.

METHODSA human neuroblastoma cell line was cultured in vitro. 1 x 10(7) cells undergoing exponential growth were collected in 0.1 ml of suspension and subcutaneously inoculated into the right flank next to the forelimb in nude mice. The biological characteristics of the developed tumors were observed, and histopathological and DNA microarray analyses were performed. The expressions of NSE in the subcutaneous tumor, metastatic tumor and the primary neuroblastoma tumor tissues from a pediatric patient were analyzed by immunohistochemistry.

RESULTSTumors successfully grew in 36 out of 48 injected mice, with a total tumor-formation rate of 75.0%. Metastasis occurred in 10 cases, and the metastatic rate was 20.8%. Tumors in five injected mice grew locally without metastasis. These tumors had large volume and the tumor weight reached up to half of the body weight of the host animal. Four mice exhibited systemic metastasis without tumor growth at the primary inoculation site. There were six mice with locally growing tumor accompanied by metastasis.

CONCLUSIONWe have successfully established a human neuroblastoma xenograft model in nude mice with high tumor growth and metastatic rates. This model depicting the natural cell growth, local infiltration and distant metastasis characteristics of human neuroblastoma, providing an ideal animal model for in vivo studies of neuroblastoma. In addition, the results of this study indicate the heterogeneous nature of neuroblastoma, it may play an important role in metastasis of this tumor.

Animals ; Cell Line, Tumor ; Child, Preschool ; Disease Models, Animal ; Female ; Gene Expression Profiling ; Humans ; Liver Neoplasms ; genetics ; metabolism ; pathology ; secondary ; Male ; Mice ; Mice, Nude ; Neoplasm Invasiveness ; Neoplasm Metastasis ; Neoplasm Transplantation ; Neuroblastoma ; genetics ; metabolism ; pathology ; secondary ; Phosphopyruvate Hydratase ; metabolism ; Tumor Burden

A large amount of nicotinamide adenine dinucleotide phosphate (NADPH) is required for fatty acid synthesis and maintenance of the redox state in cancer cells. Malic enzyme 1(ME1)-dependent NADPH production is one of the three pathways that contribute to the formation of the cytosolic NADPH pool. ME1 is generally considered to be overexpressed in cancer cells to meet the high demand for increased de novo fatty acid synthesis. In the present study, we found that glucose induced higher ME1 activity and that repressing ME1 had a profound impact on glucose metabolism of nasopharyngeal carcinoma(NPC) cells. High incorporation of glucose and an enhancement of the pentose phosphate pathway were observed in ME1-repressed cells. However, there were no obvious changes in the other two pathways for glucose metabolism: glycolysis and oxidative phosphorylation. Interestingly, NADPH was decreased under low-glucose condition in ME1-repressed cells relative to wild-type cells, whereas no significant difference was observed under high-glucose condition. ME1-repressed cells had significantly decreased tolerance to low-glucose condition. Moreover, NADPH produced by ME1 was not only important for fatty acid synthesis but also essential for maintenance of the intracellular redox state and the protection of cells from oxidative stress. Furthermore, diminished migration and invasion were observed in ME1-repressed cells due to a reduced level of Snail protein. Collectively, these results suggest an essential role for ME1 in the production of cytosolic NADPH and maintenance of migratory and invasive abilities of NPC cells.
Carcinoma ; Cell Line, Tumor ; Cell Movement ; Cell Survival ; Glucose ; metabolism ; Glycolysis ; Humans ; Malate Dehydrogenase ; metabolism ; NADP ; metabolism ; Nasopharyngeal Neoplasms ; metabolism ; pathology ; Neoplasm Invasiveness ; Oxidation-Reduction ; Oxidative Phosphorylation ; Pentose Phosphate Pathway ; Proto-Oncogene Proteins c-akt ; metabolism

Objective:To analyze and summarize the application and significance of the computer-assisted surgery system in precision surgery of mediastinal tumors in children.Methods:The clinical data of 54 children that underwent mediastinal tumor resection surgery in the Affiliated Hospital of Qingdao University from August 2008 to November 2021 were collected.According to whether the Hisense CAS computer-assisted surgery system was used before the operation, the patients were divided into three-dimensional (3D) reconstruction group (29 cases, 53.70%) and two-dimensional (2D) CT group (25 cases, 46.30%). The surgical indicators, postoperative hospital stay, and the incidence of surgical complications were compared between the two groups.The t-test, Mann- Whitney U test, χ2 test or Fisher′ s exact test were carried out for statistical analysis.Simulated surgery and actual surgery were compared for both 3D reconstruction and 2D CT groups. Results:There were no significant differences in gender, age, height, weight, maximum tumor diameter and tumor location between the 3D reconstruction group and 2D CT group (all P>0.05). The operation time of the 3D reconstruction group was [(125.14±41.37) min] was shorter than that of the 2D CT group [(149.24±44.53) min] ( P=0.044). The intraoperative blood loss in the 3D reconstruction group [15.00(13.50, 25.00) mL] was less than that in the 2D CT group [36.00(30.00, 75.00) mL] ( P<0.001). In addition, the indwelling time the closed thoracic drainage tube [4.00 (3.00, 5.50) d] and postoperative hospitalization days [(8.83±3.39) d] in the 3D reconstruction group were shorter than those in the 2D CT group [7.00(5.00, 11.50) d, (11.00±4.10) d] ( P=0.001, 0.038). No significant difference in postoperative complication rates was found between the 3D reconstruction group and 2D CT group ( P>0.05). The simulated operation was consistent with the actual operation in the 3D reconstruction group. Conclusions:3D reconstruction by the computer-assisted surgery system can truly reveal the anatomical relationship between tumors and surrounding organs and blood vessels, and improve the accuracy and safety of surgical resection of mediastinal tumors in children.

BACKGROUNDOver-expression of P-glycoprotein (P-gp), encoded by the MDR1 gene, confers multidrug resistance (MDR) in renal cell carcinoma (RCC) and is a major reason for unsuccessful chemotherapy. This study aimed to determine the effct of RNA interference (RNAi) on the reversal of MDR in human RCC.

METHODSWe designed and selected one short hairpin RNA (shRNA) targeting MDR1 gene, which is stably expressed from integrated plasmid and transfected by lentivirus fluid in human RCC A498 cell.

RESULTSThe MDR1-targeted RNAi resulted in decreased MDR1 gene mRNA level (P < 0.001), almost abolished P-gp expression and reversed MDR to different chemotherapy drugs in the RCC A498 cell line.

CONCLUSIONMDR could be reversed by RNAi in human RCC A498 cell line, which may be used for clinical application in future.

ATP-Binding Cassette, Sub-Family B, Member 1 ; genetics ; metabolism ; Carcinoma, Renal Cell ; genetics ; metabolism ; Cell Line, Tumor ; Cell Proliferation ; Humans ; Inhibitory Concentration 50 ; Lentivirus ; genetics ; RNA, Small Interfering ; genetics ; metabolism