参杞合剂对人鼻咽癌细胞CNE细胞周期及凋亡的影响

目的研究参杞合剂(SQ)在体外对CNE细胞周期及凋亡的影响。方法应用MTT法观察参杞合剂对细胞的抑制作用,流式细胞术观察不同浓度参杞合剂作用不同时间后CNE细胞周期的改变,电镜结合DNA电泳分析参杞合剂诱导凋亡的作用。结果SQ对CNE细胞生长有明显抑制作用,且其作用强度呈现出对浓度和时间的依赖性。CNE细胞在SQ作用下随着时间的延长和浓度的增加,G0/G1期比率下降,S期比率升高,出现S期阻滞。0.0625 g.生药/ml的SQ作用48 h后诱导出凋亡,凋亡率随着浓度的增加、时间的延长而增加,电镜下可见典型凋亡小体。琼脂糖凝胶电泳呈现出凋亡特征性的DNA条带。结论参杞合剂可直接杀伤肿瘤细胞,其机制可能通过阻滞细胞周期S期,诱导肿瘤细胞凋亡实现的。     

参杞制剂对小鼠抗疲劳和抗氧化作用研究

目的：探讨参杞制剂抗疲劳及抗氧化作用效果,为抗疲劳制剂的研制提供实验依据。方法：将120只雄性昆明种小鼠按体质量随机平均分为4组,分别为参杞制剂高、中、低剂量组和对照组;分批实验,每次实验从对应组中随机抽取10只小鼠。灌喂实验制剂15d后,分别测定负重力竭游泳时间,血乳酸、血清尿素氮、肝糖原、肌糖原含量及肝脏超氧化物歧化酶（soD）、丙二醛（彻A）、谷胱甘肽过氧化物酶（GsH_h）。结果：参杞制剂低、中、高3个剂量组小鼠的力竭游泳时间[（296．0±25．3）s,（437.0±38．9）s,（595．04±53．9）s]均大于对照组[（231．04±22．5）s],其中,高、中剂量组与对照组相比差异显著。运动后,参杞制剂高、中剂量组小鼠的血乳酸水平显著低于对照组;3个剂量组小鼠血尿素氮含量均低于对照组,其中,高、中剂量组与对照组的差异具有显著性;高、中剂量组小鼠肝糖原、肝脏SOD和GSH-Px含量均显著高于对照组;高剂量组小鼠MDA含量明显低于对照组。结论：参杞制剂,尤其是中高剂量组,能明显延长小鼠力竭游泳时间,并具有较强的抗疲劳与抗氧化作用。     

肺癌患者外周血血小板在肺癌血行转移中的作用研究

目的：观察肺癌患者外周血血小板对肺癌分期和血行转移的影响。方法：选择在我院呼吸科初诊的原发性肺癌患168例,分析其外周血小板计数与肺癌病理类型和分期的关系,并在模拟流体状态下,体外研究活化血小板对培养的肺癌细胞和内皮细胞相互作用的影响。结果：肺腺癌中外周血血小板计数增高现象最为明显,占37.09%（23/62）（P〈0.05）,鳞癌占22.64%,小细胞癌占22.70%,其他占14.20%。其中有远处血行转移者血小板增多（20.24%）较无明显转移者（7.14%）相差显著（P〈0.01）。同时体外研究显示流体状态对肺癌细胞粘附存在影响,而活化血小板增强了肺癌细胞与内皮细胞的相互作用。结论：血小板活化与肺癌尤其是肺腺癌的血行转移密切相关;活化血小板增强了肺癌细胞与内皮细胞的相互作用是血小板促进肺癌血行转移的重要机制之一。     

裸鼠体内高转移人肺癌模型的筛选

将人肺巨细胞癌ＰＬＡ－８０１Ｄ裸鼠皮下移植瘤作为瘤源,建立了ＰＬＡ－８０１Ｄ－ＡＳ裸鼠腹水鼠模型,其转移率及转移程度明显增高;以ＰＬＡ－８０１Ｄ－ＡＳ腹水瘤模型的肺转移灶细胞进行裸鼠皮下连续传代,建立了肺转移率及程度高于ＰＬＡ－８０１Ｄ的ＰＬＡ－８０１ＤＬ皮下移植瘤株。本文从肿瘤的异质性以及肿瘤与宿主相互作用的角度讨论了其肺转移提高的原因。     

Rho激酶对结直肠癌细胞体外侵袭转移作用的研究

目的:观察Rho激酶对结直肠癌SW480细胞黏附、运动、迁移和侵袭能力的影响.方法:SW480细胞用Rho激酶抑制剂Y-27632处理后,分别用细胞运动实验,黏附实验和迁移、侵袭实验分析对肿瘤细胞运动、黏附、迁移和侵袭能力的影响.结果:25μmol/L以上的浓度的Y-27632作用于SW480细胞后,细胞的运动能力、迁移能力明显下降(p＜0.05),细胞黏附于纤维粘连蛋白的能力也降低(p＜0.05);而且细胞穿过人工基底膜的能力明显降低(p＜0.01).结论:Rho激酶参与结直肠癌细胞体外的侵袭转移作用,Rho激酶抑制剂有望成为有效的抗恶性肿瘤转移的药物.     

糖肽对小鼠Lewis肺癌实验性转移作用的初步病理观察

我们曾报道从小鼠Lewis肺癌组织通过蛋白水解酶及分子筛层析分离的总糖肽,在体外可明显地抑制某些肿瘤细胞及分离的层粘连蛋受体与基膜成分层粘连蛋白的识别和结合。本文报告将此糖肽与Lewis肺癌细胞混合,通过尾静脉注入小鼠体内,对实验性癌转移的抑制作用。初步病理结果表明,此糖肽几乎可以完全抑制实验性转移瘤的形成,保护小鼠不死于癌转移。提示糖肽可能具有阻断癌转移之作用。将实验组一部分存活小鼠再行同种癌细胞皮下接种,可以照常成瘤。表明糖肽阻抑实验性癌转移的效能可能并非调动了宿主的免疫机制所致。糖肽还可减慢皮下接种的癌细胞的生长速度,但对癌细胞并无直接毒性作用。     

肺癌转移抑制相关基因研究进展

肺癌是发病率和死亡率增长最快、对人类健康威胁最大的恶性肿瘤之一。侵袭转移是肺癌患者死亡的首要原因。研究表明,在肺癌中发挥转移抑制作用的相关基因主要有nm23、KAI1、TIMP、Cadherin以及MRP-1等。本文对近年来这些基因的研究进展及其对肺癌侵袭转移的抑制作用作一综述     

微RNA调节肺癌转移的分子机制

微RNA(microRNA,miRNA)是一类长约22 nt的非编码小分子RNA,在转录后水平上通过基因沉默调节靶基因的活性。近年来,miRNA与肿瘤转移关系的研究成为探讨肿瘤转移调控机制的热点。越来越多的研究提示miRNA在肿瘤转移过程中发挥着重要作用。肺癌转移是影响肺癌预后的关键,是一种复杂的多因素、多步骤、多基因参与调控的过程。研究miRNA对肺癌转移的作用有助于我们找到阻断肺癌转移的靶点。本文就miRNA和肺癌转移关系的研究进展作一综述。     

小鼠移植性肺癌转移模型研究进展

小鼠移植性肺癌转移模型是进行肺癌研究的重要工具,对阐释肺癌的转移机制以及肺癌相关药物的研发都具有重要意义.本文综合考虑肺癌转移易发生的部位及肿瘤的种属差异,对该模型进行进一步分类,同时详细地论述了每种类型的建模方法、评价指标,为肺癌相关研究提供模型参考.     

埃兹蛋白的表达与非小细胞肺癌转移的关系研究

目的:探究埃兹蛋白(Ezrin)的表达与非小细胞肺癌转移的关系。方法:通过免疫组化检测Ezrin在有无转移的非小细胞肺癌组织中的表达差异,通过细胞免疫组化、western-blot、RT-PCR检测Ezrin在不同转移潜能肺癌细胞系中的表达差异,通过transwell考察Ezrin对不同转移潜能癌细胞侵袭和迁移能力的影响。结果:Ezrin蛋白在有转移的非小细胞肺癌组织中的表达水平明显高于无转移的肺癌组织,在高转移潜能肺癌细胞系中的表达高于低转移潜能细胞系,受抑制时会削弱高转移潜能肺癌细胞的迁移和侵袭能力,过表达时会增强低转移潜能肺癌细胞的侵袭和迁移能力。结论:Ezrin可能在非小细胞肺癌及其转移中发挥重要作用。     

Inhibition of breast cancer cell adhesion and bone metastasis by the extracellular adherence protein of Staphylococcus aureus

Bone metastasis is a common sequelae of breast cancer and the interaction of alpha v beta3-integrin with osteopontin (OPN) found in the extracellular matrix of mineralized tissues is implicated in this process. The integrin-dependent proadhesive and promigratory functions of OPN are particularly attributed to the 40 kD N-terminal fragment that derives upon matrix metalloproteinase (MMP) cleavage. Based on the broad repertoire of interactions between Staphylococcus aureus extracellular adherence protein (Eap) and host components, we here characterized Eap to specifically interact with recombinant full-length OPN and the 40 kD N-terminal MMP cleavage fragment, but not with the 32 kD or the 25 kD C-terminal fragments of OPN. Eap thereby prevented the OPN/alpha v beta3-integrin interaction, as well as the alpha v beta3-integrin-dependent adhesion of MDA-MB-231 breast cancer cells to full-length OPN or to the 40 kD fragment and the migration of these cells towards OPN. Furthermore, Eap treatment markedly impaired the development of osseous metastasis of human MDA-MB-231 cells in vivo. Taken together, Eap may represent an attractive novel treatment for the prevention of breast cancer bone metastasis.     

Inhibitory role of focal adhesion kinase on anoikis in the lung cancer cell A549

Resistance to anoikis is a characteristic of malignant cells with increased tumorigenesis and metastasis. Altered FAK activity has been strongly implicated in the development, growth, progression, and metastasis of human cancers, but the mechanism of FAK in regulating anoikis is unknown. In this study, the resistance anoikis role of FAK and its downstream mediators was evaluated in the human lung cancer cell line A549. It has been shown that down regulation of FAK stimulates the apoptosis of cells and the down-regulation of p-ERK, p-PI3K, p-Src, and p-p38. Furthermore, in detached A549 cells, increased FAK phosphorylations (Tyr397, Tyr861, Tyr925) were detected in a time-dependent manner, and the specific inhibitors of MEK1, PI3K, and Src (PD98059, LY294002, and PP2) partly abolished the resistance to the anoikis characteristic of cancer cells. Altogether, our data suggested that Src is involved in the progress of detachment-induced FAK activation in lung tumor cells. PI3K/AKT, MAPK-ERK, and perhaps MAPK-p38 but not MAPK-JNK, appear to be the key downstream effectors of FAK in mediating cell survival. The increased FAK activity upon cell detachment may contribute to the metastasis potential of malignant tumors.     

High affinity binding of VIP to human lung cancer cell lines

The binding of ¹²⁵I-VIP to human lung cancer cell lines was investigated. Radiolabeled VIP bound to adenocarcinoma, squamous cell carcinoma, large cell carcinoma and small cell lung cancer (SCLC) cell lines. As SCLC cell line NCI-N592 bound radiolabeled VIP well, its binding was further characterized. ¹²⁵I-VIP bound to membranes in a specific and time dependent manner. ¹²⁵I-VIP bound with high (Kd=0.8 nM) and moderate affinity (Kd=66 nM) to two classes of sites. Pharmacology studies indicated that the order of peptide potency was VIP PHI > secretin > VIP^10–28. Because VIP receptors are present on human lung cancer cells, VIP may function as a regulatory peptide in lung cancer.     

Human natural killer cell activity against porcine targets: modulation by control of the oxidation-reduction environment and role of adhesion molecule interactions

Xenotransplantation, especially using porcine sources, has been proposed as a means to alleviate the shortage of human organs for transplantation. NK cells appear to be important mediators of the xenogeneic immune responses, including the human anti-pig response. Having previously established the redox regulation of NK cell activity against tumor target cells, we now report that the interaction of human NK cells with porcine target cells is also regulated by redox. Thiol-deprivation strongly diminished the capacity of IL-2-activated human NK cells to kill porcine endothelial cells. This inhibition correlated with reduced proliferation and interferon (IFN)-gamma production by IL-2-activated NK cells. For fresh NK cells, pretreatment with diethyl maleate (DEM), which was used to deplete intracellular thiols, reduced lysis of porcine and human targets. Because many adhesion molecules exhibit interspecies recognition, we further investigated whether changes in expression of adhesion molecules might explain our observations. DEM treatment reduced the expression of CD11b and CD29 on fresh NK cells. Monoclonal antibody blocking studies showed that the combination of mAb to CD11b and CD18 reduced lytic activity against both PAEC as well as K562, although other qualitative differences were observed between the porcine and human target cells. These findings suggest that the oxidative stress-induced downregulation of CD18 may be important in modulating cytotoxic activity of fresh NK cells against PAEC and K562 targets through reduced formation of the CD11b/CD18 heterodimer. Thus, the appropriate manipulation of redox status may provide a means to enhance survival of non-human animal tissues in humans through modulation of adhesion molecule expression/interactions.     

Hypermethylation of the Keap1 gene in human lung cancer cell lines and lung cancer tissues

Low expression of the oxidative stress sensor Keap1 is thought to be involved in carcinogenesis. However, the mechanisms responsible for inactivation of the Keap1 gene remain unknown. We investigated Keap1 expression using RT-PCR and found that it was downregulated in lung cancer cell lines and tissues when compared with a normal bronchial epithelial cell line. Treatment with 5-Aza-2′-deoxycytidine restored Keap1 expression in lung cancer cell lines, indicating the silencing mechanism to be promoter methylation. Moreover, we evaluated cytosine methylation in the Keap1 promoter and demonstrated that the P1 region, including 12 CpG sites, was highly methylated in lung cancer cells and tissues, but not in normal cells. Importantly, we found evidence that three specific CpG sites (the 3rd, 6th, and 10th CpGs of P1) might be binding sites for proteins that regulate Keap1 expression. Thus, our results suggest for the first time that Keap1 expression is regulated by an epigenetic mechanism in lung cancer.     

Pro-inflammatory effect of TWEAK/Fn14 interaction on human umbilical vein endothelial cells

TWEAK, a member of the TNF family, induces cell death in some tumor cell lines, but also induces proliferation of endothelial cells and angiogenesis. Recently, fibroblast growth factor-inducible 14 (Fn14) has been identified to be a TWEAK receptor, which may be responsible for the proliferation of endothelial cells and angiogenesis. In this study, we investigated the pro-inflammatory effect of TWEAK on human umbilical vein endothelial cells (HUVEC). We demonstrated that TWEAK could not only induce the proliferation and migration but also upregulate the cell surface expression of adhesion molecules such as ICAM-1 and E-selectin, and induce the secretion of chemokines such as IL-8 and MCP-1 in HUVEC. Moreover, by using an anti-Fn14 mAb that blocks the TWEAK/Fn14 interaction, we demonstrated that Fn14 was constitutively expressed on HUVEC and totally mediated the biological effects of TWEAK on HUVEC. These results indicated that TWEAK could induce pro-inflammatory reactions via Fn14 on HUVEC.     

Physical interaction between Tbx6 and mespb is indispensable for the activation of bowline expression during Xenopus somitogenesis

Crk is a member of a family of adaptor proteins that are involved in intracellular signal pathways altering cell adhesion, proliferation, and migration. Increased expression of Crk has been described in lung cancer and associated with increased tumor invasiveness. MicroRNAs (miRNAs) are a family of small non-coding RNAs (approximately 21–25 nt long) that are capable of targeting genes for either degradation of mRNA or inhibition of translation. Crk is a predicted putative target gene for miR-126. Over-expression of miR126 in a lung cancer cell line resulted in a decrease in Crk protein without any alteration in the associated mRNA. These lung cancer cells exhibit a decrease in adhesion, migration, and invasion. Decreased cancer cell invasion was also evident following targeted knockdown of Crk. MiR-126 alters lung cancer cell phenotype by inhibiting adhesion, migration, and invasion and the effects on invasion may be partially mediated through Crk regulation.     

肺癌发病及骨转移相关因素分析

目的:探讨肺癌发病的可能相关因素。方法:选择87例确诊为肺癌的患者,收集患者的一般资料,临床信息以及诊断和治疗信息,其中伴骨转移者39例。结果:发病年龄平均67.8岁;6例(35.3%)女性患者为吸烟者,58例(97.7%)男性患者有吸烟史。女性吸烟人数及吸烟量增多;咳嗽为最常见的症状;病理组织学男性患者多为鳞癌,女性腺癌多见;Ⅲ和Ⅳ期明显多于Ⅰ期和Ⅱ期。虽然外科手术治疗后可以提高患者生存时间,接受外科手术患者仍较少。骨转移与性别、年龄和放化疗与否无关,与病理类型有关。结论:年龄、吸烟与肺癌发病密切相关,多数患者就诊时为中晚期,多只能接受姑息治疗,早期诊断及其重要。腺癌患者需警惕骨转移。     

Potential influence of interleukin-6 on the therapeutic effect of gefitinib in patients with advanced non-small cell lung cancer harbouring EGFR mutations

Although epidermal growth factor receptor-tyrosine kinase inhibitors (EGFR-TKIs) are a key therapy used for patients with EGFR-mutant non-small cell lung cancer (NSCLC), some of whom do not respond well to its therapy. Cytokine including IL-6 secreted by tumour cells is postulated as a potential mechanism for the primary resistance or low sensitivity to EGFR-TKIs. Fifty-two patients with advanced EGFR-mutant NSCLC who had received gefitinib were assessed retrospectively. The protein expression of IL-6 in the tumour cells was assessed by immunostaining and judged as positive if ≥ 50 of 100 tumour cells stained positively. Of the 52 patients, 24 (46%) and 28 (54%) were defined as IL-6-postitive (group P) and IL-6-negative (group N), respectively. Group P had worse progression-free survival (PFS) than that of group N, which was retained in the multivariate analysis (hazard ratio: 2.39; 95 %CI: 1.00–5.68; p < 0.05). By contrast, the PFS after platinum-based chemotherapy did not differ between groups P and N (p = 0.47). In cell line-based model, the impact of IL-6 on the effect of EGFR-TKIs was assessed. The combination of EGFR-TKI and anti-IL-6 antibody moderately improved the sensitivity of EGFR-TKI in lung cancer cell with EGFR mutation. Interestingly, suppression of EGFR with EGFR-TKI accelerated the activation of STAT3 induced by IL-6. Taken together, tumour IL-6 levels might indicate a subpopulation of EGFR-mutant NSCLC that benefits less from gefitinib monotherapy.     

Protein kinase C Inhibitors selectively modulate dynamics of cell adhesion molecules and cell death in human colon cancer cells

During development of colon cancer, Protein Kinase Cs (PKCs) are involved in regulation of many genes controlling several cellular mechanisms. Here, we examined the changes in cell adhesion molecules and PKCs for colorectal cancer progression. We identified that PKCs affected expression of EpCAM, claudins, tetraspanins. Treatment with low concentrations of PKC inhibitors resulted in decreased cell viability. In addition, immunoblotting and qRT-PCR analysis showed that apoptosis was inhibited while autophagy was induced by PKC inhibition in colon cancer cells. Furthermore, we observed decreased levels of intracellular Reactive Oxygen Species (ROS), lipid peroxidation and protein carbonyl, confirming the ROS-induced apoptosis. Taken together, our results reveal that PKC signalling modulates not only cell adhesion dynamics but also cell death-related mechanisms.

Abbreviations: PKC: Protein Kinase C; EpCAM: Epithelial cell adhesion molecule; FBS: fetal bovine serum; MTT: 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide); CAM: cell adhesion molecule; ROS: reactive oxygen species