Effect of blocking Ras signaling pathway with K-Ras siRNA on apoptosis in esophageal squamous carcinoma cells

AbstractObjectiveTo study the effect of RNAi silencing of the K-Ras gene on Ras signal pathway activity in EC9706 esophageal cancer cells.MethodsEC9706 cells were treated in the following six groups: blank group (no transfection), negative control group (transfection no-carrier), transfection group (transfected with pSilencer-siK-ras), taxol chemotherapy group, taxol chemotherapy plus no-carrier group, taxol chemotherapy plus transfection group. Immunocytochemistry, Reverse transcription-polymerase chain reaction and western blotting were used to analyze the expression of MAPK1 (mitogen-activated protein kinases 1) and cyclin D1 in response to siRNA (small interfering RNA) transfection and taxol treatment.ResultsK-Ras (K-Ras gene) siRNA transfection of EC9706 esophageal squamous carcinoma cells decreased the expression of K-Ras, MAPK1 and cyclin D1 at the mRNA and protein level. Reverse transcription-polymerase chain reaction indicated that the expression levels of MAPK1 and cyclin D1 mRNAs were significantly lower in the transfection group than in the blank group (P<0.05). Western blotting showed that 72 h after EC9706 cell transfection, the expression levels of MAPK1 and cyclin D1 proteins had decreased in all groups, and the expression levels in the transfection group were significantly inhibited as compared with the blank group. Apoptosis increased significantly in the transfection group or after addition of taxol as compared with the blank group and the no-carrier group. The degree of apoptosis in the taxol plus transfection group was more severe.ConclusionApoptosis increased significantly in EC9706 esophageal carcinoma cells after siRNA-mediated inhibition of Ras signaling, with the most obvious increase observed in the transfection plus taxol chemotherapy group. Ras knockdown therefore increased cellular sensitivity to the chemotherapeutic agent, taxol. Ras knockdown also down-regulated the expression of the downstream genes, MAPK1 and cyclin D1, thus inhibiting the growth, proliferation and metabolism of esophageal cancer cells

Effect of blocking Ras signaling pathway with K-Ras siRNA on apoptosis in esophageal squamous carcinoma cells

AbstractObjectiveTo study the effect of RNAi silencing of the K-Ras gene on Ras signal pathway activity in EC9706 esophageal cancer cells.MethodsEC9706 cells were treated in the following six groups: blank group (no transfection), negative control group (transfection no-carrier), transfection group (transfected with pSilencer-siK-ras), taxol chemotherapy group, taxol chemotherapy plus no-carrier group, taxol chemotherapy plus transfection group. Immunocytochemistry, Reverse transcription-polymerase chain reaction and western blotting were used to analyze the expression of MAPK1 (mitogen-activated protein kinases 1) and cyclin D1 in response to siRNA (small interfering RNA) transfection and taxol treatment.ResultsK-Ras (K-Ras gene) siRNA transfection of EC9706 esophageal squamous carcinoma cells decreased the expression of K-Ras, MAPK1 and cyclin D1 at the mRNA and protein level. Reverse transcription-polymerase chain reaction indicated that the expression levels of MAPK1 and cyclin D1 mRNAs were significantly lower in the transfection group than in the blank group (P<0.05). Western blotting showed that 72 h after EC9706 cell transfection, the expression levels of MAPK1 and cyclin D1 proteins had decreased in all groups, and the expression levels in the transfection group were significantly inhibited as compared with the blank group. Apoptosis increased significantly in the transfection group or after addition of taxol as compared with the blank group and the no-carrier group. The degree of apoptosis in the taxol plus transfection group was more severe.ConclusionApoptosis increased significantly in EC9706 esophageal carcinoma cells after siRNA-mediated inhibition of Ras signaling, with the most obvious increase observed in the transfection plus taxol chemotherapy group. Ras knockdown therefore increased cellular sensitivity to the chemotherapeutic agent, taxol. Ras knockdown also down-regulated the expression of the downstream genes, MAPK1 and cyclin D1, thus inhibiting the growth, proliferation and metabolism of esophageal cancer cells

Synthesis and Anticancer Activity Evaluation of Novel Phenanthridine Derivatives

Based on the structure of sanguinarine, fourteen phenanthridine derivatives were designed and synthesized in the current study. The cytotoxic activities of synthesized compounds were evaluated against five human cancer cell lines (MCF-7, PC3, Hela, A549, and HepG2 cell lines) via MTT assay. Among all the compounds tested, molecule 8a exhibited significant cytotoxic activity against MCF-7 cells with a IC50 value of 0.28 μM. A following up enzymatic assay indicated that compound 8a could inhibit the activity of DNA topoisomerase I/II. Further mechanistic studies performed in the MCF-7 cell line revealed that compound 8a could arrest cell cycle in S phase and induce cell apoptosis via downregulation of Bcl-2 and upregulation of Bax. Collectively, a potent DNA topoisomerase inhibitor (8a) was discovered, which exhibited potential as a candidate chemotherapeutic agent for the management of tumors in the present study

Expression of HIWI in human esophageal squamous cell carcinoma is significantly associated with poorer prognosis

<p>Abstract</p> <p>Background</p> <p>HIWI, the human homologue of Piwi family, is present in CD34⁺hematopoietic stem cells and germ cells, but not in well-differentiated cell populations, indicating that HIWI may play an impotent role in determining or maintaining stemness of these cells. That HIWI expression has been detected in several type tumours may suggest its association with clinical outcome in cancer patients.</p> <p>Methods</p> <p>With the methods of real-time PCR, western blot, immunocytochemistry and immunohistochemistry, the expression of HIWI in three esophageal squamous cancer cell lines KYSE70, KYSE140 and KYSE450 has been characterized. Then, we investigated HIWI expression in a series of 153 esophageal squamous cell carcinomas using immunohistochemistry and explored its association with clinicopathological features.</p> <p>Results</p> <p>The expression of HIWI was observed in tumour cell nuclei or/and cytoplasm in 137 (89.5%) cases, 16 (10.5%) cases were negative in both nuclei and cytoplasm. 86 (56.2%) were strongly positive in cytoplasm, while 49 (32.0%) were strongly positive in nuclei. The expression level of HIWI in cytoplasm of esophageal cancer cells was significantly associated with histological grade (<it>P </it>= 0.011), T stage (<it>P </it>= 0.035), and clinic outcome (<it>P </it>< 0.001), while there was no correlation between the nuclear HIWI expression and clinicopathological features.</p> <p>Conclusion</p> <p>The expression of HIWI in the cytoplasm of esophageal cancer cells is significantly associated with higher histological grade, clinical stage and poorer clinical outcome, indicating its possible involvement in cancer development.</p

Problematic Stabilizing Films in Petroleum Emulsions: Shear Rheological Response of Viscoelastic Asphaltene Films and the Effect on Drop Coalescence

Adsorption of asphaltenes at the water-oil interface contributes to the stability of petroleum emulsions by forming a networked film that can hinder drop-drop coalescence. The interfacial microstructure can either be liquid-like or solid-like, depending on (i) initial bulk concentration of asphaltenes, (ii) interfacial aging time, and (iii) solvent aromaticity. Two techniques--interfacial shear rheology and integrated thin film drainage apparatus--provided equivalent interface aging conditions, enabling direct correlation of the interfacial rheology and droplet stability. The shear rheological properties of the asphaltene film were found to be critical to the stability of contacting drops. With a viscous dominant interfacial microstructure, the coalescence time for two drops in intimate contact was rapid, on the order of seconds. However, as the elastic contribution develops and the film microstructure begins to be dominated by elasticity, the two drops in contact do not coalescence. Such step-change transition in coalescence is thought to be related to the high shear yield stress (~10(4) Pa), which is a function of the film shear yield point and the film thickness (as measured by quartz crystal microbalance), and the increased elastic stiffness of the film that prevents mobility and rupture of the asphaltene film, which when in a solid-like state provides an energy barrier against drop coalescence

Causal analysis of coach and bus accidents in China based on road alignments

Given the complexity and the difficulty of controlling contributors effectively, road passenger transport often results in serious injuries and fatalities. The purpose of this study is to identify the main contributors to coach and bus accidents and to provide policy recommendations for making improvements in accident prevention. The Driving Reliability and Error Analysis Method 3.0 (DREAM 3.0) was modified and used to analyze the contributing factors (i.e. phenotypes and genotypes in DREAM) and their casual mechanisms. By having statistical analysis and social network analysis (SNA) adopted, the main genotypes and phenotypes of the DREAM charts were identified. The results of the study showed that A2.1 (too high speed) was the key phenotype and the main genotypic process chain leading to the phenotype was “inadequate safety management → inadequate training → inadequate skills/knowledge → misjudgment of the situation → too high speed” on all types of road. For A2.1 (too high speed), C2 (misjudgment of the situation) was the dominant genotype, while N5 (inadequate safety management) was the root cause of most genotypes. This suggests that road passenger transport companies, as the responsible parties, often fail to implement or violate safety prevention and control systems. Government regulators should promote the policy system and incentivize them to fulfil their safety management responsibilities. The government should also educate the public and improve the road environment to reduce passenger-related risks and the impact of environmental factors on drivers

Synthesis and property evaluation of a salt- and alkali-resistant star-polymer

A salt-and alkali-resistant star-polymer was made using graft β-CD functional monomer and acrylamide monomer employing copolymerization and post-hydrolysis methods. The optimum parameters: azobisisobutyronitrile with a concentration of 50 mg/L, a mass fraction of acrylamide 25%, a graft β-CD functional monomer mass fraction of 1.5%, initiating temperature 5°C, hydrolysis temperature 90°C and hydrolysis time of 3 hours. The atomic force microscope and infrared spectroscopy morphology characterization results show that: the star-polymer S07313 contains the star-nucleu of the graft β-CD functional monomer. The molecular weight of the star-polymer S07313 is 24.5 million, while other basic physical and chemical properties can meet the technical requirements of the application of such a polymer in oil fields. With the addition of NaOH as a mass fraction of 1.0% in the Daqing simulated brine, the apparent viscosities of the star-polymer S07313, HPAM3000 and MO4000 are 42.40 mPa·s, 29.20 mPa·s and 18.00 mPa·s. The star-polymer S07313 and surface active agents Alkylbenzene Sulfonate have an excellent compatibility. 摘 要: 采用接枝β-CD抗盐碱功能单体与丙烯酰胺共聚后水解的方法制备超高相对分子质量抗盐碱星形聚合物。其最佳工艺参数为：偶氮二异丁腈质量浓度为50 mg/L、丙烯酰胺质量分数为25%、接枝β-CD抗盐碱功能单体质量分数为1.5%、引发温度为5 ℃、水解温度为90 ℃、水解时间为3.0 h。原子力显微镜形貌观察和红外光谱表征结果表明：抗盐碱星形聚合物S07313含有星核接枝β-CD功能单体。抗盐碱星形聚合物S07313的相对分子质量为2 450×104，其他基本理化性能都能达到油田应用指标的技术要求。当大庆模拟盐水中加入NaOH质量分数为1.0%的碱水时，抗盐碱星形聚合物S07313、HPAM3000和MO4000的表观黏度分别为42.40 mPa·s、29.20 mPa·s和18.00 mPa·s。抗盐碱星形聚合物与表面活性剂重烷基苯磺酸盐的配伍性优良。图10表3参20 Key words: star-polymer, graft β-CD functional monomer, salt-resistance, alkali-resistanc

Genome-Wide Identification and Expression Analysis of the Protease Inhibitor Gene Families in Tomato

The protease inhibitors (PIs) in plants are involved primarily in defense against pathogens and pests and in response to abiotic stresses. However, information about the PI gene families in tomato (Solanum lycopersicum), one of the most important model plant for crop species, is limited. In this study, in silico analysis identified 55 PI genes and their conserved domains, phylogenetic relationships, and chromosome locations were characterized. According to genetic structure and evolutionary relationships, the PI gene families were divided into seven families. Genome-wide microarray transcription analysis indicated that the expression of SlPI genes can be induced by abiotic (heat, drought, and salt) and biotic (Botrytis cinerea and tomato spotted wilt virus (TSWV)) stresses. In addition, expression analysis using RNA-seq in various tissues and developmental stages revealed that some SlPI genes were highly or preferentially expressed, showing tissue- and developmental stage-specific expression profiles. The expressions of four representative SlPI genes in response to abscisic acid (ABA), salicylic acid (SA), ethylene (Eth), gibberellic acid (GA). and methyl viologen (MV) were determined. Our findings indicated that PI genes may mediate the response of tomato plants to environmental stresses to balance hormone signals. The data obtained here will improve the understanding of the potential function of PI gene and lay a foundation for tomato breeding and transgenic resistance to stresses

MiR-433-3p Inhibits Proliferation and Invasion of Esophageal Squamous Cell Carcinoma by Targeting GRB2

Background/Aims: MicroRNAs (miRNAs) are non-coding single stranded RNAs of 17-25 nucleotides in size, and their altered expression has been observed in various cancers. Previous studies have confirmed that miR-433-3p has effects on cancer cell proliferation, invasion, and migration, and its expression also correlates with sensitivity to chemotherapy. However, to date, there have been no studies on the biological functions of miR-433-3p in esophageal squamous cell carcinoma (ESCC). Methods: The Cell Counting Kit-8, transwell, and matrigel assays were used to test the effects of miR-433-3p and its predicted target, growth factor receptor-bound protein 2 (GRB2), on the proliferation, migration, and invasion of Eca109 and KYSE30 cells, two types of esophageal cancer cell lines. The miR-433-3p binding site in the 3′ untranslated region (UTR) region of GRB2 was predicted and verified using miRNA target site prediction software and structuring correct mutant examination. Western blotting and fluorescent quantitative PCR (FQ-PCR) techniques were employed to evaluate GRB2 expression. The inhibitory effects of miR-433-3p on tumor growth were investigated using a tumor xenograft model. Results: The binding site of miR-433-3p was identified in the 3′UTR region of GRB2. Western blotting and FQ-PCR showed that miR-433-3p inhibited the mRNA and protein expression of GRB2. Overexpression of GRB2 inhibited tumorigenesis in nude mice. MiR-433-3p overexpression inhibited the proliferation, migration, and invasion of ESCC cells by suppressing GRB2 gene expression. Conclusions: Our findings suggest that targeting miR-433-3p may have therapeutic benefits in ESCC