胃癌干细胞在胃癌侵袭、转移中及血管形成中的作用和机制

BACKGROUND: Although tumor stem cells and their differentiated vascular cells, which are not sensitive to chemotherapy and molecular targeted therapy, reduce overall blood supply of the tumor, these cells facilitate the invasion and metastasis of the tumor, eventually resulting in treatment failure.     

肿瘤干细胞与转移

肿瘤干细胞（ cancer stem ce11,CSC）的某些基本生物学性能,如CSC启动和维持癌繁殖的能力,符合最终形成转移所必需的条件。已有实验证明癌干细胞具有转移能力。癌干细胞呈异质性,其中含有具转移能力的亚群。癌巢侵袭性边缘的单个癌细胞可发生上皮-间质转化（ epithe1ia1-mesen-chyma1 transition,EMT）,从而变成CSC状态。对播散性瘤细胞的分析证明其中所含表达CSC的癌细胞比原发灶多。微环境对转移CSC具有重要作用。休眠瘤细胞与CSC有显著的相似性。微环境改变与瘤细胞休眠的起止过程密切相关。     

胃癌干细胞CSC-G在胃癌侵袭和转移中的作用

BACKGROUND: Studies have shown that cancer stem cells play an important role in tumor invasion and metastasis, but studies on the role of gastric cancer stem cells in invasion and metastasis of gastric cancer cells were rarely reported. OBJECTIVE: To study the effect of gastric cancer stem cells CSC-G on invasion and metastasis of gastric cancer cells. METHODS: Gastric cancer stem cells CSC-G and gastric cancer cells SGC7901 were cultured in vitro for 10 days followed by spherical colony formation assay, western blot assay for detecting OCT4, SOX2, E-cadherin and CD44 protein expression levels in gastric cancer stem cells CSC-G and gastric cancer cells SGC7901, and Transwell assay for detecting the invasion and migration of gastric cancer stem cells and gastric cancer cells SGC7901. RESULTS AND CONCLUSION: Gastric cancer cells SGC7901 in RPMI1640 medium presented with adherent growth and were quadrilateral or polygonal after passage; gastric cancer stem cells CSC-G in serum-free medium presented with suspension growth, and adherent gastric cancer stem cells were spindle-shaped or round. Compared with gastric cancer cells SGC7901, the protein expressions of OCT4, SOX2 and CD44, the number of cancer cell spheres and the number of trans-membrane cells were significantly increased in the gastric cancer stem cells CSC-G (P < 0.05), and the expression of E-cadherin protein was significantly decreased (P < 0.05). These findings indicate that the gastric cancer stem cells CSC-G can be successfully cultured in vitro, and have enhanced invasion and migration compared with the gastric cancer cells SGC7901, which play an important role in gastric cancer invasion and metastasis.      

VEGF和MMP-2的表达对肝细胞癌侵袭转移的影响

采用免疫组化 ABC法对 5 0例肝细胞癌手术切除标本的血管内皮生长因子 (VEGF)和基质金属蛋白酶- 2 (MMP- 2 )表达进行检测 ,以探讨 VEGF及 MMP- 2在肝细胞癌中的表达与其复发、转移的关系。结果发现 VEGF和 MMP- 2在肝细胞癌组织中的阳性表达率分别为 86 % (43/5 0 )和 6 0 % (30 /5 0 ) ,在正常肝组织中分别为 5 3.3%(16 /30 )和 30 % (9/30 ) ,癌组织与正常组织间存在着显著差异 (P<0 .0 5 ) ;VEGF和 MMP- 2的阳性表达率与肝细胞癌的转移和包膜形成相关 ,在肝细胞癌生长、侵袭和转移过程中起着重要的作用 ,对预测肝细胞癌复发、转移具有重要的意义     

肿瘤淋巴管形成与肿瘤转移关系的研究进展

恶性肿瘤是严重危害人类健康的常见疾病 ,造成恶性肿瘤治疗困难的主要原因之一是恶性肿瘤常发生远处部位的转移。如果肿瘤只局限在原发部位 ,则通过手术等方法可使患者治愈 ,转移是肿瘤患者死亡的主要原因。肿瘤发生播散和转移的途径主要有 :(1)局部浸润 ,体腔、体表种植 ;(2 )通过血管的血行转移 ;(3)通过淋巴管的淋巴转移等。其中通过淋巴管常常是某些肿瘤初始转移阶段的最主要途径 ,肿瘤细胞进入引流淋巴结 ,继而再进入血流 ,造成更广泛的远处转移 ,威胁患者的生命。在过去的 10余年中 ,肿瘤新生血管的研究成为肿瘤研究的一个热点。自 19…     

骨髓间充质干细胞促进肺癌转移的机制

BACKGROUND:So far the positive or negative effects of mesenchymal stem cells on tumor growth and metastasis are under discussion. OBJECTIVE:To explore the mechanism of bone marrow mesenchymal cells in promoting lung cancer metastasis. METHODS: Primary rat bone marrow mesenchymal stem cells were obtained by direct adherence method of the whole bone marrow, and differential adherence combined with digestion control method was performed to purify cells. Lung cancer cell lines were cultured, and the effects of bone marrow mesenchymal stem cells on the migration, invasion and metastasis of lung cancer cells were observed by scratch test, cell invasion and migration assays. Orthotopic lung cancer models were established in rats and bone marrow mesenchymal stem cells were seeded onto the left lung of rats. Then, pathological changes of lung tissues were observed at 14 days after transplannation. RESULTS AND CONCLUSION:After the scratch test, the migration rate of lung cancer cells became higher, and the scratches healed with time. And after cell transplantation, the number of migrated lung cancer cells increased, as well as the ability of lung cancer cells penetrating the Matrigel was strengthened. Besides, fibrous connective tissues could be found around the lung cancer tissues, and necrosis with distinct boundary and large tumor nuclei; the metastatic tissues showed obvious infiltration and necrosis with large tumor nuclei. These results suggest that bone marrow mesenchymal stem cells can promote the invasion, migration and metastasis of lung cancer cell lines.       

血管内皮生长因子与胃癌侵袭和转移关系的研究进展

胃癌是我国最常见的恶性肿瘤之一,死亡率在各种恶性肿瘤中占首位,诊治水平的提高使早期胃癌患者的长期生存率有了很大提高,但是进展期胃癌患者的预后仍然很不理想。肿瘤转移是胃癌患者死亡的主要原因。而恶性肿瘤的发生、发展、侵袭及转移的各个阶段均有赖于新生血管的生成。血管生成是恶性肿瘤生长和转移的基础。血管内皮生长因子（vascular endothelial growth factor,VEGF）是机体最重要的刺激血管生成的生长因子,能特异结合于血管内皮细胞,在体内外都能促进血管内皮细胞增殖,而成为近年来研究的热点。     

肿瘤干细胞表面标记物CD44在胃癌浸润和淋巴结转移中的作用

背景：肿瘤干细胞不仅能启动肿瘤发生,还参与肿瘤细胞的侵袭和转移。对肿瘤干细胞来说,识别其特异性细胞表面标志物已成为研究热点。 目的：探讨肿瘤干细胞表面标记物CD44在胃癌浸润和淋巴结转移中的临床意义。 方法：采用免疫组化 SABC法检测胃癌组织标本CD44蛋白表达,应用Pearsonχ2检验和Cox回归多因素分析,确定CD44表达与胃癌生物学特性及其预后的相关性。 结果与结论：100例胃癌标本中,59例(59.0%)标本CD44蛋白呈阳性表达。CD44蛋白在距胃癌原发灶边缘5 cm以上的正常胃黏膜组织中呈阴性表达。胃癌组织中CD44蛋白广泛表达,主要表达于细胞膜,少量表达于细胞浆。胃癌组织中 CD44蛋白的表达和患者性别、年龄无关(P > 0.05),但与肿瘤分期和淋巴管浸润、组织学分级、肿瘤大小等有关(P < 0.05),其中,肿瘤浸润越深、组织学分级越高、肿瘤直径越大、有淋巴结转移,则CD44蛋白表达阳性率越高,CD44阳性表达是影响患者术后生存的独立预后因素(P < 0.05)。以上结果表明肿瘤干细胞表面标记物CD44在胃癌组织中的表达与胃癌的浸润和淋巴结转移密切相关,表达越高患者预后越差。 中国组织工程研究杂志出版内容重点：干细胞;骨髓干细胞;造血干细胞;脂肪干细胞;肿瘤干细胞;胚胎干细胞;脐带脐血干细胞;干细胞诱导;干细胞分化;组织工程     

上皮间质转化在胃癌SGC7901细胞向胃癌干细胞转化过程中的作用

BACKGROUND: Studies have found that epithelial-mesenchymal transition is closely related with tumor invasion, metastasis, and drug resistance, but studies on the role of epithelial-mesenchymal transition in the transformation process of gastric cancer cells SGC7901 to gastric cancer stem-like cells are rarely reported. OBJECTIVE: To explore the effect of epithelial-mesenchymal transition in the transformation process of gastric cancer cells SGC7901 to gastric cancer stem-like cells. METHODS: Vincristine-induced SGC7901 cells were cultured and screened to prepare gastric cancer stem-like cells. CD44 phenotype, morphological changes, stem cell-related markers, and epithelial-mesenchymal transition related molecules were detected. RESULTS AND CONCLUSION: After passage, vincristine-induced SGC7901 cells presented with morphological changes, and clonal cell spheres generated after serum-free suspension culture. Meanwhile, the proportion of SGC7901 cells positive for CD44 was decreased. Expression levels of SOX2, OCT4, Snail1 mRNA, Twist mRNA and Vimentin mRNA were significantly higher in the gastric cancer stem-like cells than SGC7901 cells, but the expression level of E-caderin was lower in the gastric cancer stem-like cells than SGC7901 cells. These findings indicate that gastric cancer cells SGC7901 can be successfully transformed into gastric cancer stem-like cells, and the epithelial-mesenchymal transition is involved in this transforming progress.       

肿瘤干细胞在肿瘤转移中作用与相关机制的研究进展

目前国内外对肿瘤转移的机制已进行了系统而深入的探索。随着肿瘤干细胞概念的提出和相关领域的深入研究,肿瘤干细胞作为肿瘤转移的最佳候选细胞的观点正逐渐被人们接受。目前和肿瘤转移过程相关的分子细胞机制包括:上皮间质转变(EMT)、肿瘤微环境及血管生成机制等。近年来许多研究成果显示上述机制在肿瘤干细胞转移过程中起到不可低估的作用。本文就肿瘤干细胞转移相关机制的进展做一简要综述。     

人原代胃癌细胞中肿瘤干细胞的分化培养

BACKGROUND:There is a close relationship between tumor stem cells and tumor occurrence and recurrence, but there are still some disputes in the presence of tumor stem cells in all tumors. OBJECTIVE:To investigate the differentiation and culture of tumor stem cells in human primary gastric cancer cells. METHODS:Primary gastric cancer cells isolated from fresh gastric cancer tissues were stained with hematoxylin-eosin and identified by immunohistochemical detection of carcinoembryonic antigen. The CD44 expression of the cells was detected using immunofluorescence method. Magnetic activated cell sorting was used to isolate CD44⁺ gastric cancer cells that were then seeded subcutaneously behind the armpit of mice. Growth of implanted tumor cells was observed. RESULTS AND CONCLUSION:Human primary gastric cancer cells were isolated in serum-free medium. Compared with the routine culture group, the number of CD44⁺ cells (P < 0.05) and the tumor volume were significantly increased in the spheroid culture group. Furthermore, at 90 days after transplantation, the tumor volume of mice in spheroid culture group was significantly higher than that in the routine culture group. These experimental findings indicate that gastric cancer cells with certain tumorigenicity can be successfully isolated from gastric cancer cells using serum-free culture method and magnetic activated cell sorting method.     

顺铂在大鼠体内富集胃癌干细胞

背景：肿瘤干细胞具有自我更新、耐药和转移成瘤能力,对肿瘤的发生、发展以及肿瘤的转移等具有重要的功能。目前,确认肿瘤干细胞的方法主要有2种,即体外瘤球培养实验以及小鼠体内成瘤实验,但临床上通过化疗在大鼠体内富集胃癌细胞尚缺乏研究报道。 目的：观察顺铂在大鼠体内富集胃癌干细胞的情况,研究其表面标志蛋白的筛选方法。 方法：建立BGC-823胃癌模型大鼠,采用随机对照方法将大鼠分为2组,实验组大鼠分别尾静脉注射质量浓度0.1,0.2,0.25,0.3 g/L的顺铂,而对照组则尾静脉注射生理盐水。经过3期化疗,最后得到富集胃癌干细胞组织;采用高通量蛋白芯片对肿瘤表面蛋白进行提取,并采用Western blot对芯片进行验证,比较顺铂在大鼠体内富集胃癌干细胞及其表面标志蛋白的筛选方法。 结果与结论：顺铂剂量为0.3 g/L×200 μL时治疗效果最佳,且化疗药物浓度越高,耐受力越差,不良反应发生率越高。移植瘤经苏木精-伊红染色验证均为癌组织;Western blot检测结果与蛋白芯片结果显示,HLA-DQ,PMP22和Claudin7蛋白在胃癌组织中表达增强,HLA-DR,CD14,CD16和CD56蛋白表达减弱。结果证实,顺铂化疗能够在体内富集胃癌干细胞,能够成功筛选出相应的表面标志物蛋白。中国组织工程研究杂志出版内容重点：干细胞;骨髓干细胞;造血干细胞;脂肪干细胞;肿瘤干细胞;胚胎干细胞;脐带脐血干细胞;干细胞诱导;干细胞分化;组织工程     

胃癌干细胞抗原负载树突细胞与细胞因子诱导的杀伤细胞

BACKGROUND:As the existence of tumor stem cells, it is difficult to completely eliminate tumors in clinic. OBJECTIVE:To explore the tumor-killing effect of gastric cancer stem cells as antigen to stimulate dendritic cells combined with cytokine-induced killer cells. METHODS:Side population cells from human gastric cancer cell lines were isolated, and tumor antigen was prepared by freeze thawing method. After coculture with dendritic cells, dendritic cells combined with cytokine-induced killer cells, gastric cancer cell antigen, and gastric cancer stem cell antigen, killing rates of gastric cancer cells were detected using MTT assay. Expression rate of CD83, a mature dendritic cell surface marker, was also detected. RESULTS AND CONCLUSION:The CD83 expression level and killing rate of gastric cancer cells were both significantly lower in the gastric cancer stem cell antigen group than the other groups (both P < 0.05). These results indicate that gastric cancer stem cells as antigen to stimulate dendritic cells combined with cytokine-induced killer cells can promote the proliferation of gastric cancer cells and elevate the ability to killing gastric cancer cells.     

肿瘤干细胞表面标记物CD44在胃癌组织中的表达及意义

BACKGROUND:Studies have shown that CD44 expression is closely associated with malignant transformation of gastric cancer. OBJECTIVE:To study the expression of CD44 in gastric cancer tissues and its clinical significance. METHODS:Gastric cancer specimens from 94 cases of gastric cancer after surgery and normal gastric tissue specimens from 30 cases undergoing gastroscope examination were collected and detected using S-P method. The positive expression rate of CD44 protein in these two groups was compared, and the relationship between CD44 and prognosis was analyzed. RESULTS AND CONCLUSION:The positive expression rate of CD44 protein in the gastric cancer group (73%) was significantly higher than that in the normal group (3%) (P < 0.05). The positive expression rate of CD44 protein in gastric cancer patients was remarkably associated with TNM stage, differentiation degree, invasion depth and lymph node metastasis (P < 0.05). The 3-year survival rate of gastric cancer patients positive for CD44 protein was significantly lower than that of negative patients (P < 0.05). The higher TNM staging indicated the lower differentiation degree, and lymph node metastasis and CD44 positive expression were independent risk factors (P < 0.05). To conclude, the expression of CD44 protein is related to the clinical pathological features and prognosis of gastric cancer patients to some extents.     

胃癌干细胞表面标记物的研究与最新进展

背景:最近人们研究发现,肿瘤的复发与肿瘤干细胞密切相关。肿瘤干细胞理论为研究胃癌的发病机制以及诊治开辟了新的途径,确定的表型有利于锁定胃癌干细胞,这有助于探讨胃癌干细胞在自我更新和分化过程中的作用,并为治疗胃癌提供新思路,但其表型仍存在争议。目的:综述胃癌干细胞表面标志物的研究进展。方法:由第一作者分别以"Gastric Cancer Stem Cells"为英文关键词检索PubM ed英文数据库(http://www.ncbi.nlm.nih.gov/pubmed)中1965年1月至2015年10月的文献,共保留68篇文献进行综述。结果与结论:通过分析整理,传统上的肿瘤干细胞表型不适合于标记胃癌干细胞。研究发现CD90在胃癌原发性肿瘤中有表达,分离后经无血清肿瘤球培养法培养可获得肿瘤球。CD24的表达有助于提高胃癌细胞的黏附、侵袭、迁移能力。此外研究证实CD44及CD54共表达的细胞会大量出现在胃癌复发早期患者的体内而不是晚期,表达CD44及CD54的肿瘤细胞很可能是导致胃癌发生以及复发的重要原因。综上所述,CD44^+CD24^+CD90^+CD54^+很可能是胃癌干细胞的表型。     

胃癌干细胞对5-氟尿嘧啶的敏感性

背景：5-氟尿嘧啶是一种常用的胃癌化疗药物,但临床治疗过程中较易出现耐药现象,影响治疗效果。研究表明肿瘤干细胞对化疗药敏感性较低,可能是导致化疗耐药的重要原因。 目的：体外环境下分析胃癌干细胞对5-氟尿嘧啶的敏感性,了解胃癌化疗耐药相关机制。 方法：基于克隆形态的分选策略,从人胃癌AGS细胞系内分离胃癌干细胞克隆,采用免疫细胞化学染色分析不同克隆CD44和胸苷酸合成酶的表达,克隆形成实验评估不同类型克隆的自我更新能力,CCK-8法检测不同浓度5-氟尿嘧啶作用下人胃癌AGS细胞克隆生长抑制率。 结果与结论：人胃癌AGS细胞经低密度接种培养后,可形成32个不同形态的克隆,其中,副克隆、次克隆、全克隆所占比例分别为19%(6/32)、66%(21/32)、16%(5/32)。全克隆高表达CD44和胸苷酸合成酶,接种后可再次形成大量二代克隆;次克隆弱表达CD44和胸苷酸合成酶,接种后形成少量的二代克隆;副克隆不表达或弱表达CD44和胸苷酸合成酶,接种后未形成二代克隆。在不同浓度5-氟尿嘧啶的作用下,次克隆以及人胃癌AGS细胞的生长抑制率均显著高于全克隆(P均 < 0.05)。结果表明,在体外条件下,胃癌干细胞对5-氟尿嘧啶敏感性较低,推测其可能为临床化疗耐药的重要机制。中国组织工程研究杂志出版内容重点：干细胞;骨髓干细胞;造血干细胞;脂肪干细胞;肿瘤干细胞;胚胎干细胞;脐带脐血干细胞;干细胞诱导;干细胞分化;组织工程     

姜黄素通过ATK/FoxM1信号通路调控胃癌干细胞增殖及凋亡

BACKGROUND:Curcumin has crucial inhibitory effects on various cancer cells and cancer stem cells. However, its effect on gastric cancer stem cells and the underlying mechanism of this effect are unclear. OBJECTIVE:To explore the effect of curcumin on gastric cancer stem cells and the underlying mechanism. METHODS:Tumor sphere-forming assay and gastric cancer stem cell markers (EpCAM and CD44) were used to separate gastric cancer stem cells from gastric cancer SGC7901 cell lines. Effects of curcumin on the proliferation and apoptosis of gastric cancer stem cells were determined by MTT and flow cytometry analysis, respectively. Western blot analysis was used to detect the expression levels of FoxM1, p-AKT, and AKT. LY294002, an inhibitor of the PI3K/AKT pathway, was used to determine the regulatory relationship between AKT and FoxM1 signaling pathways. RESULTS AND CONCLUSION:The EpCAM+/CD44+ gastric cancer stem cells were successfully isolated from SGC7901 cells. MTT assay showed that curcumin inhibited the proliferation of gastric cancer stem cells, while flow cytometry analysis showed that curcumin induced apoptosis in gastric cancer stem cells. In addition, the expression levels of p-AKT and FoxM1 were decreased by curcumin treatment. After being treated by LY294002, the expression levels of p-AKT and FoxM1 were down-regulated markedly. In conclusion, curcumin can inhibit cell proliferation and induce apoptosis in gastric cancer stem cells via the ATK/FoxM1 signaling pathway.