拉米夫定联合TACE治疗原发性肝癌临床观察

目的研究拉米夫定联合经皮肝动脉栓塞化疗术(Transcatheter arterial chemoembolization,TACE)治疗HBV-DNA阳性肝癌的疗效。方法选取我院住院患者102例原发性肝癌患者为研究对象,分为TACE+拉米夫定治疗组(50例),TACE对照组(52例),分别进行治疗,观察2组患者HBV-DNA水平、肝功能指标和child评分。结果治疗组HBV-DNA水平、肝功能指标和治疗效果均优于对照组,差异具有显著性(P<0.05)。结论拉米夫定联合TACE治疗乙肝病毒相关性肝癌患者,可抑制病毒复制,提高治疗效果。     

Cellular Integrin α5β1 and Exosomal ADAM17 Mediate the Binding and Uptake of Exosomes Produced by Colorectal Carcinoma Cells

Approximately 25% of colorectal cancer (CRC) patients develop peritoneal metastasis, a condition associated with a bleak prognosis. The CRC peritoneal dissemination cascade involves the shedding of cancer cells from the primary tumor, their transport through the peritoneal cavity, their adhesion to the peritoneal mesothelial cells (PMCs) that line all peritoneal organs, and invasion of cancer cells through this mesothelial cell barrier and underlying stroma to establish new metastatic foci. Exosomes produced by cancer cells have been shown to influence many processes related to cancer progression and metastasis. In epithelial ovarian cancer these extracellular vesicles (EVs) have been shown to favor different steps of the peritoneal dissemination cascade by changing the functional phenotype of cancer cells and PMCs. Little is currently known, however, about the roles played by exosomes in the pathogenesis and peritoneal metastasis cascade of CRC and especially about the molecules that mediate their interaction and uptake by target PMCs and tumor cells. We isolated exosomes by size−exclusion chromatography from CRC cells and performed cell-adhesion assays to immobilized exosomes in the presence of blocking antibodies against surface proteins and measured the uptake of fluorescently-labelled exosomes. We report here that the interaction between integrin α5β1 on CRC cells (and PMCs) and its ligand ADAM17 on exosomes mediated the binding and uptake of CRC-derived exosomes. Furthermore, this process was negatively regulated by the expression of tetraspanin CD9 on exosomes.     

Transmembrane TNF and Its Receptors TNFR1 and TNFR2 in Mycobacterial Infections

Tumor necrosis factor (TNF) is one of the main cytokines regulating a pro-inflammatory environment. It has been related to several cell functions, for instance, phagocytosis, apoptosis, proliferation, mitochondrial dynamic. Moreover, during mycobacterial infections, TNF plays an essential role to maintain granuloma formation. Several effector mechanisms have been implicated according to the interactions of the two active forms, soluble TNF (solTNF) and transmembrane TNF (tmTNF), with their receptors TNFR1 and TNFR2. We review the impact of these interactions in the context of mycobacterial infections. TNF is tightly regulated by binding to receptors, however, during mycobacterial infections, upstream activation signalling pathways may be influenced by key regulatory factors either at the membrane or cytosol level. Detailing the structure and activation pathways used by TNF and its receptors, such as its interaction with solTNF/TNFRs versus tmTNF/TNFRs, may bring a better understanding of the molecular mechanisms involved in activation pathways which can be helpful for the development of new therapies aimed at being more efficient against mycobacterial infections.     

The Study of the Inhibition of the Recombinant TACE Prodomain to Endotoxemia in Mice

Objective:

To demonstrate the inhibitory function of the prodomain of tumor necrosis factor-α (TNF-α) converting enzyme (TACE) on TACE activity and to develop an approach to interfere with inflammation processes.

Methods:

The cDNA encoding the full-length ectodomain (T1300) and prodomain (T591) of TACE were amplified by RT-PCR. The expression plasmids (pET-28a (+)-T1300 and pET-28a (+)-T591) were constructed and transformed into E. coli BL21. After Ni²⁺-NTA resin affinity chromatography, the recombinant T591 protein was obtained and assayed. In order to detect its inhibiton of TACE activity, the mice in the LPS-induced endotoxemia model group were treated with the recombinant TACE prodomain protein prior to the injection of LPS. Murine peritoneal macrophages were isolated from mice abdominal cavity for FCM and the liver, kidney and lung were removed for traditionally histopathology sectioning.

Results:

The FCM results showed that the recombinant prodomain protein decreased the release of the sTNF-α, which mediated the accumulation of TNF-α on the surface of macrophage cells. HE staining proved that the recombinant protein can decrease the inflammatory response in internal organs of endotoxaemia mice.

Conclusions:

The recombinant prodomain of TACE has the ability to inhibit sTNF-α release, which indicates that prodomain is an effective antagonist of TACE and might be useful in the molecular design of anti-inflammatory drugs.     

Stabilization of the autoproteolysis of TNF-alpha converting enzyme (TACE) results in a novel crystal form suitable for structure-based drug design studies

The crystallization of TNF-alpha converting enzyme (TACE) has been useful in understanding the structure-activity relationships of new chemical entities. However, the propensity of TACE to undergo autoproteolysis has made enzyme handling difficult and impeded the identification of inhibitor soakable crystal forms. The autoproteolysis of TACE was found to be specific (Y352-V353) and occurred within a flexible loop that is in close proximity to the P-side of the active site. The rate of autoproteolysis was found to be proportional to the concentration of TACE, suggesting a bimolecular reaction mechanism. A limited specificity study of the S(1)' subsite was conducted using surrogate peptides and suggested substitutions that would stabilize the proteolysis of the loop at positions Y352-V353. Two mutant proteases (V353G and V353S) were generated and proved to be highly resistant to autoproteolysis. The kinetics of the more resistant mutant (V353G) and wild-type TACE were compared and demonstrated virtually identical IC(50) values for a panel of competitive inhibitors. However, the k(cat)/K(m) of the mutant for a larger substrate (P6 - P(6)') was approximately 5-fold lower than that for the wild-type enzyme. Comparison of the complexed wild-type and mutant structures indicated a subtle shift in a peripheral P-side loop (comprising the mutation site) that may be involved in substrate binding/turnover and might explain the mild kinetic difference. The characterization of this stabilized form of TACE has yielded an enzyme with similar native kinetic properties and identified a novel crystal form that is suitable for inhibitor soaking and structure determination.     

巴曲酶灌注联合肝动脉化疗栓塞治疗原发性肝癌的临床初步研究

Objective:The aim of the study was to explore the therapeutic efficacy and safety of batroxobin in patients with primary hepatic carcinoma(PHC)and the advantages of transcatheter arterial perfusion of batroxobin combined with transcatheter arterial chemoembolization(TACE).Methods:Forty patients with PHC were randomized into experimental group(transcatheter arterial perfusion of batroxobin combined with TACE treatment,20 patients)and control group(TACE alone group,20 patients).The patients were followed up and the data were recorded,compared and analyzed.Results:(1)Compared with the control group,the FIB level in the experimental group was significantly decreased at the first month after treatment(P<0.05).(2)The baseline of the tumor was shortened in both groups after the treatment.There was a significant difference between the two groups at different time intervals(P<0.05).(3)After the treatment,there was a significant difference of progression-free survival(PFS)levels between the two groups(t=2.877,P<0.05).(4)The incidence of metastasis were 5.0%(1/20)in both groups at 6 months after treatment,and that after one year was 10.0%(2/20)in the experimental group and 25.0%(5/20)in the control group.However,the difference was not significant(x2=0.693,P>0.05).Conclusion:Batroxobin can rapidly and effectively decrease the FIB level of the PHC cases.Therefore it may be used as an effective and safe adjuvant drug for the treatment of primary hepatic carcinomas.Transcatheter arterial perfusion of batroxobin combined with TACE therapy has advantages in comparison with TACE alone therapy.It could be taken as a new therapeutic regimen in the PHC treatment.     

肝动脉栓塞化疗与恩度联合应用对兔VX2肝移植瘤血管生成的影响

目的探讨肝动脉栓塞化疗(Transcatheter arterial chemoembolization,TACE)与恩度联合应用对兔VX2肝移植瘤血管生成的影响。方法建立兔VX2肝移植瘤模型,并随机分为TACE组、抗血管生成组(TACE+动脉给予恩度)和生理盐水对照组。TACE术后14d,应用实时定量荧光PCR检测残癌组织血管内皮生长因子(Vascular endothelial growth factor,VEGF)mRNA的转录水平,免疫组化法检测肿瘤组织微血管密度(Microvessel density,MVD),并分析二者的相关性。结果TACE组VEGF mRNA的转录水平明显高于抗血管生成组和对照组(P均<0.05);抗血管生成组与对照组相比,差异无统计学意义(P>0.05)。抗血管生成组MVD(33.17±6.69)明显低于TACE组(59.96±12.19)和对照组(58.88±7.82),且差异均有统计学意义(P均<0.05);TACE组与对照组相比,差异无统计学意义(P>0.05)。各组肿瘤组织VEGF mRNA的转录水平与MVD的分布均呈正相关(r=0.40)。结论TACE与恩度联合应用与单纯应用TACE相比,可明显抑制肿瘤的血管生成。