Tailoring subtractive cell biopanning to identify diffuse gastric adenocarcinoma-associated antigens via human scFv antibodies

Among various solid tumours, gastric cancer (GC) is one of the leading causes of cancer-related deaths worldwide. Expansion into the peritoneal cavity, which results from dissemination of diffuse cancer cells, is the main cause of mortality in gastric adenocarcinoma patients. Therefore, investigation of putative biomarkers involved in metastasis is prerequisite for GC management. In an effort to discover potential tumour markers associated with peritoneal metastasis of GC, a semi-synthetic human scFv library (Tomlinson I) was used to isolate novel antibody fragments recognizing MKN-45, a poorly differentiated diffuse gastric adenocarcinoma cell line. Four rounds of subtractive selection each consisting of extensive pre-absorption of phage library with NIH-3T3 murine embryonic fibroblasts and AGS (a well-differentiated intestinal gastric adenocarcinoma) cell line were carried out prior to positive selection on MKN-45 target cells. ELISA-based screening of 192 phage-displayed scFv clones indicated 21 high-affinity binders with specific staining of MKN-45 compared with AGS cells. Diversity analysis of the selected phage-scFvs resulted in five distinct sequences with multiple frequency. Further analysis by ELISA and flow cytometry verified three clones that specifically recognized MKN-45 cells. Liquid chromatography-mass spectrometry analysis of the scFv-immunoprecipitated proteins has led to identification of c-Met, HSP90 α and HSP90 β as candidate biomarkers associated with diffuse GC. Immunohistochemistry revealed the capability of purified scFvs to differentiate diffuse and intestinal gastric adenocarcinoma. Taken together, the isolated MKN-45-specific scFv fragments and their cognate antigens would be beneficial in screening and management as well as targeting and therapy of the diffuse gastric adenocarcinoma.     

A new liver metastatic and peritoneal dissemination model established from the same human pancreatic cancer cell line: analysis using cDNA macroarray

To elucidate the mechanisms of metastasis, we established two sublines HPC-1H5 with a highly liver metastatic cell line and HPC-1P5a with a highly peritoneal disseminating cell line, which were sequentially selected from the parental pancreatic cancer cell line HPC-1. Using these three cell lines, we investigated several biological properties and mRNA levels of differentially-expressed genes involved in cancer metastasis by cDNA macroarray. Microscopic findings for the three cell lines were the same. The tumorigenicity, in vitro growth ability, motile activity, adhesive activity and the production of IL-8 of metastatic sublines were higher than those of parental HPC-1 cells. Particularly, HPC-1H5 cells showed clearly higher levels of IL-8 expression and tumors of HPC-1H5 cells grew faster and bigger than those of HPC-1P5a cells. In cDNA macroarray analysis of HPC-1H5 cells, 22 genes were up-regulated and 44 genes were down-regulated compared with parental HPC-1 cells. In HPC-1P5a cells, 9 genes were up-regulated and 28 genes were down-regulated compared with parental HPC-1 cells. This study provides a demonstration of global gene expression analysis of pancreatic cancer cells with liver metastasis and peritoneal dissemination. Furthermore, our results provide a new insight into the study of liver metastasis and peritoneal dissemination of human pancreatic cancer. This revised version was published online in July 2006 with corrections to the Cover Date.     

TNF-α promotes progression of peritoneal metastasis as demonstrated using a green fluorescence protein (GFP)-tagged human gastric cancer cell line

The mechanisms underlying progression of peritoneal metastasis by gastric cancer after micrometastasis formation remain unclear. In the present study, we investigated metastasis to the abdominal wall peritoneum, one of the major features of peritoneal spread, using a human gastric cancer cell line (GCIY-EGFP) tagged with the green fluorescence protein gene (GFP). This model allows sensitive, specific and sequential observation of metastasis development from the initial deposits to peritoneal carcinomatosis at the end stage. In the initial phase, GCIY-EGFP cells could form micrometastasis selectively on the omentum and mesenterium in a milky spot-dependent manner, but not on abdominal wall peritoneum lacking milky spots until the late stages. In vitro analysis using primary mesothelial cells revealed addition of TNF-alpha to decrease their stress fibers, leading to morphological change followed by exposure of the submesothelial extracellular matrix (ECM) in intercellular gaps. Such TNF-alpha pretreatment was found to enhance attachment of tumor cells to the mesothelial monolayer. When tumor cells were injected into the peritoneal cavity of TNF-alpha pretreated mice, they could metastasize to the abdominal wall peritoneum from the very early stages, resulting in accelerated accumulation of ascites than in TNF-alpha non-pretreatment controls. RT-PCR analysis revealed that tumor cells express cytokines and chemokines, including TNF-alpha. Furthermore, TNF-alpha treatment results in up-regulation of expression of monocyte chemoattractant protein-1 (MCP-1) and IL-8 by mesothelial cells and of TNF-alpha itself by inflammatory leukocytes in the peritoneal cavity. These results suggest that metastasis to the abdominal wall peritoneum occurs as a second step from the first omental metastasis in a milky spot-independent manner and that TNF-alpha derived from tumor cells, mesothelial cells and inflammatory leukocytes in the peritoneal cavity may be involved in the progression of peritoneal metastasis.     

Regional administration of oncolytic Echovirus 1 as a novel therapy for the peritoneal dissemination of gastric cancer

The dissemination of malignant gastric cells to the peritoneum occurs frequently, usually as an early event in disease, and results in poor patient prognosis. Surgery and chemotherapy offer limited therapeutic success. The low-pathogenic human enterovirus, Echovirus 1 (EV1), is an oncolytic virus that selectively targets and destroys malignant prostate and ovarian cancer xenografts in vivo. Lytic EV1 infection requires the cell surface expression of α₂β₁, an integrin involved in the dissemination of gastric cancer cells to the peritoneum. Herein, we evaluated the capacity of EV1 for anti-neoplastic cell action in gastric peritoneal carcinomatosis. Flow cytometric analysis demonstrated that α₂β₁ was abundantly surface expressed on a panel of gastric cancer cell lines, rendering the majority of lines highly susceptible to in vitro lytic EV1 infection and supportive of efficient viral progeny production. A bioluminescent MKN-45-Luc SCID mouse model of peritoneal dissemination was developed to allow real-time non-invasive monitoring of peritoneal tumor burden. Employing this mouse model, we demonstrated a therapeutic dose-response for escalating oncolytic EV1 doses. Taken together, these results emphasize the exciting potential for EV1 as a single or adjunct therapy for the control of the peritoneal dissemination of gastric cancer.     

CUB-domain-containing protein 1 regulates peritoneal dissemination of gastric scirrhous carcinoma

CUB-domain-containing protein 1 (CDCP1) is a type-I transmembrane protein that is highly expressed in colon, breast, and lung cancers. We recently revealed that CDCP1 is associated with and phosphorylated by Src family kinases and is involved in the regulation of anchorage independence of certain lung cancer cell lines. In this study, we examined whether CDCP1 is involved in the regulation of tumor progression of scirrhous gastric cancer, which is a diffusely infiltrative carcinoma with high invasion potential. Expression and phosphorylation levels of CDCP1 correlated with the invasive potential of scirrhous gastric cancers. Reduction of CDCP1 expression by siRNA suppressed migration, invasion, and anchorage independence without affecting the proliferation of highly invasive scirrhous gastric cancer cells. However, CDCP1 overexpression promoted gastric cancer cell migration with low potential of invasion. Loss of CDCP1 suppressed invasion and dissemination of cancer cells that were orthotopically implanted in the gastric wall of nude mice. Expression and phosphorylation of CDCP1 were also detected in cancer cells of surgically resected tissues of human scirrhous gastric cancer by immunohistochemical analysis. Our results suggest that CDCP1 promotes invasion and peritoneal dissemination of cancer cells through the regulation of cell migration and anchorage independence. Therefore, it is both a potential prognostic and therapeutic target in certain types of gastrointestinal cancers, and suppression of its phosphorylation might be a useful strategy for modulating cancer metastasis.     

人绒毛膜癌裸鼠原位移植模型的建立

目的建立人绒毛膜癌裸鼠原位移植瘤模型。方法培养人绒毛膜癌细胞系JAR,制备JAR单细胞悬液,给5只8周龄BALB/c裸鼠经皮下注射建立皮下移植瘤模型。待裸鼠皮下成瘤后,无菌条件下取瘤组织并切成1 mm^3组织块,通过手术方式植入10只10周龄BALB/c裸鼠子宫腔内,裸鼠濒死状时4%水合氯醛(10 g/kg)腹腔注射麻醉处死,观察子宫成瘤及腹腔转移情况。解剖取子宫原位移植瘤、腹腔内转移瘤、腹腔淋巴结及其他脏器组织标本,通过组织病理学检查进行鉴定。结果10只BALB/c裸鼠中共有7只裸鼠子宫内可见移植瘤肿块形成,其中2只可同时观察到子宫移植瘤和腹膜转移瘤。在病理学形态和结构上,皮下移植瘤模型、原位移植模型和腹膜转移瘤的瘤细胞与人绒毛膜癌细胞系JAR一致。结论成功建立人绒毛膜癌JAR细胞的BALB/c裸鼠原位移植瘤模型。     

Lipid-mediated gene transfection of intercellular adhesion molecule-1 suppresses the peritoneal metastasis of gastric carcinoma

We have previously reported that a decreased expression level of ICAM-1 in cancer cells frequently led to the development of lymph node metastasis, and suggested that ICAM-1 gene transfection may inhibit lymph node metastasis. In the present study, we investigated whether ICAM-1 gene therapy for the peritoneal metastasis of gastric carcinoma is useful as a new immuno-gene therapy. ICAM-1 gene was transfected into a gastric cancer cell line, OCUM-2MD3 (2MD3), which has a high metastatic ability to the peritoneum. A transfectant cancer cell line, 2MD3/ICAM-1, had high ICAM-1 expression on the cell surface. The adhesion and cytotoxicity abilities of peripheral blood mononuclear cells were significantly increased against 2MD3/ICAM-1 cells in comparison with 2MD3 cells. Mice inoculated with 2MD3/ICAM-1 cells in the peritoneal cavity had a significantly better survival rate than those inoculated with 2MD3 cells (log-rank test, p<0.05). Histologic findings revealed that more mononuclear cells existed around the metastatic nodules in 2MD3/ICAM-1. Although gastric carcinoma frequently causes peritoneal metastasis, no useful therapy for the metastasis of gastric carcinoma has been developed. These findings revealed that ICAM-1 gene transfection to cancer cells could be a useful immuno-gene therapy for the peritoneal metastasis of gastric carcinoma.     

Orthotopic microinjection of human colon cancer cells in nude mice induces tumor foci in all clinically relevant metastatic sites

Despite metastasis as an important cause of death in colorectal cancer patients, current animal models of this disease are scarcely metastatic. We evaluated whether direct orthotopic cell microinjection, between the mucosa and the muscularis layers of the cecal wall of nude mice, drives tumor foci to the most relevant metastatic sites observed in humans and/or improves its yield as compared with previous methods. We injected eight animals each tested human colorectal cancer cell line (HCT-116, SW-620, and DLD-1), using a especially designed micropipette under binocular guidance, and evaluated the take rate, local growth, pattern and rate of dissemination, and survival time. Take rates were in the 75 to 88% range. Tumors showed varying degrees of mesenteric and retroperitoneal lymphatic foci (57 to 100%), hematogenous dissemination to liver (29 to 67%) and lung (29 to 100%), and peritoneal carcinomatosis (29 to 100%). Tumor staging closely correlated with animal survival. Therefore, the orthotopic cell microinjection procedure induces tumor foci in the most clinically relevant metastatic sites: colon-draining lymphatics, liver, lung, and peritoneum. The replication of the clinical pattern of dissemination makes it a good model for advanced colorectal cancer. Moreover, this procedure also enhances the rates of hematogenous and lymphatic dissemination at relevant sites, as compared with previously described methods that only partially reproduce this pattern.     

奥沙利铂结合 CIK 细胞对人胃癌裸鼠腹膜移植模型体内抗肿瘤作用的实验研究

目的 比较单独应用奥沙利铂(L-OHP)、细胞因子诱导的杀伤(CIK细胞)和L-OHP联合CIK细胞对人胃癌裸鼠腹膜移植瘤生长的抑制作用,为临床上联合应用L-OHP和CIK细胞治疗胃癌提供实验依据.方法 通过提取健康供血者的PBMC,分别加入γ-IFN、IL-2、抗-CD3单克隆抗体和IL-1培养CIK细胞;用药效学体内实验法和病理形态学方法分别观察正常对照组、生理盐水对照组、不同剂量的L-OHP组、不同剂量的CIK细胞组和L-OHP CIK组对人胃癌裸鼠腹膜移植模型的体内抗肿瘤作用.结果 与NS对照组相比,L-OHP组(1.125、2.25 mg/kg)、CIK细胞组[(1～2)×108 mL-1]组人胃癌裸鼠腹膜移植模型治疗后生存期均明显延长,腹围明显减小(P＜0.01);L-OHP CIK组人胃癌裸鼠腹膜移植模型治疗后生存期进一步明显延长,腹围明显减小(P＜0.01),与正常对照组相比,上述指标无明显差异(P＞0.01).病理形态学结果显示,L-OHP组、CIK细胞组及L-OHP CIK组癌细胞坏死、凋亡改变逐渐加重.结论 L-OHP联合CIK细胞对人胃癌裸鼠腹膜移植瘤生长的抑制作用大于单独应用L-OHP或CIK细胞.     

Membrane-type 1 matrix metalloproteinase enhances lymph node metastasis of gastric cancer

The mechanisms of the lymph node metastasis remain unclear. We demonstrate the role of MT1-MMP on the lymph node metastasis using in vivo experimental model of lymph node metastasis by orthotopic implantation of MT1-MMP transfected gastric cancer cell line in the stomach of nude rats. TMK-1 cell line without expression of MT1-MMP was transfected with the pcDNA3 plasmid containing a 3.4-kb MT1-MMP cDNA fragment by calcium phosphate method, and the transfected cell line was designated as TMK-MT. Western blot and RT-PCR analyses showed the specific bands corresponding to MT1-MMP in the TMK-MT cells. By gelatin zymography, the activated form (62-kDa) of MMP-2 was identified in the medium of TMK-MT cell line, but was not detected in TMK-1 cells. Six weeks after orthotopic implantation of TMK-1 and TMK-MT xenografts of nude mouse-subcutaneus tumor into the stomach of nude rats, gastric tumors were found in all the animals. Histologically, the lymphatic invasion was found in the submucosa of the TMK-MT gastric tumors. Lymph node metastasis was not detected in nude rats bearing TMK-1 gastric tumor (0/8). In contrast, lymph node metastasis was detected in five out of 8 rats, bearing TMK-MT gastric tumor. MT1-MMP immunoreactivity was found on the cell membrane and cytoplasm of TMK-MT cells not only in the lymph node metastasis but also in the stomach tumor. These results suggest that MT1-MMP overexpression induced by transfection of its gene may promote lymph node metastasis of transformed cells. This revised version was published online in July 2006 with corrections to the Cover Date.     

Establishment and characterization of three novel human gastric cancer cell lines with differentiated intestinal phenotype derived from liver metastasis

Gastric cancers with liver metastasis are fatal diseases with rapid progression and poor patient outcome. To date, however, the molecular basis of their growth and metastasis remains essentially unknown, largely because of the presence of few available gastric cancer cell lines established from liver metastasis. In the present study, we developed two novel cultured cell lines (designated GLM-1 and GLM-2) and one transplantable line in nude mice (designated GLM-3) derived from liver metastasis of gastric cancer patients. These GLM cell lines share unique biological features such as differentiation, growth and metastasis. They form moderately differentiated tumors with CD10 positive and MUC2 negative intestinal absorptive phenotype when injected into nude mice. Their growth is stimulated by EGF and TGF-α in vitro like other gastric cancer cell lines. However, GLM cells differ from conventional gastric cancer cell lines in their high apoptotic rate, even in the absence of apoptosis inducing stimuli as revealed by Caspase3/7 assay and the TUNEL method. This apoptosis is further enhanced by phosphatidylinositol 3-kinase (PI3K) inhibitor (LY294002), but not by MEK1/2 inhibitor (U0126), indicating the strong dependency of their survival on PI3K/Akt pathway rather than MAPK pathway, the major downstream signaling pathways of EGFR. GLM-1 cells can metastasize to the liver after intrasplenic injection, and GLM-3 cells have spontaneous lung metastatic potential after subcutaneous transplantation, respectively. These results indicate that the GLM series are the first cell lines reflecting the intestinal-type differentiated adenocarcinoma, a major subtype of gastric cancer with liver metastasis. Therefore, they would be excellent models for understanding the mechanism of metastatic growth and the development of a new molecular targeting therapy for gastric cancer with liver metastasis.     

Adhesion polypeptides are useful for the prevention of peritoneal dissemination of gastric cancer

We examined the effect of adhesion polypeptides on the adhesion and invasiveness of gastric cancer cell lines. We previously reported the establishment of an extensively peritoneal-seeding cell line, OCUM-2MD3, from a poorly seeding human scirrhous gastric carcinoma cell line, OCUM-2M. Both 21 and 31 integrin expression was markedly increased on OCUM-2MD3 cells compared with OCUM-2M cells, and the ability of OCUM-2MD3 cells to bind to the extracellular matrix (ECM) was also significantly higher than that of OCUM-2M cells. The adhesion polypeptides, YIGSR and RGD, and two RGD derivatives significantly inhibited the adhesion of OCUM-2MD3 cells to the submesothelial ECM, while not inhibiting the adhesiveness of OCUM-2M cells and two well differentiated human gastric cell lines, MKN-28 and MKN-74. The YIGSR and RGD peptides also significantly inhibited the invasiveness of OCUM-2MD3 cells. The survival of nude mice with peritoneal dissemination given YIGSR sequenc e intraperitoneally was obviously longer than that of untreated mice. The survival of mice treated with RGD was also improved, and this effect was increased using the RGD derivatives, poly(CEMA-RGDS) and CM-chitin RGDS. These polypeptides appear to block the binding of integrins, which are expressed on OCUM-2MD3 cells, to the submesothelial ECM, and consequently inhibit peritoneal implantation. The peritoneal injection of adhe-sion polypeptides may be a new therapy against the dissemination of scirrhous gastric cancer, and may be useful for the prevention of dissemination in high-risk patients. © Rapid Science Ltd.     

Peritoneal metastatic model for human scirrhous gastric carcinoma in nude mice

We established a peritoneal-metastatic model for scirrhous gastric carcinoma. Peritoneal metastasis had developed after intraperitoneal inoculation of OCUM-2MD3 cells in nude mice. This cell line was derived from a peritoneal-metastatic nodule at the mesenterium after orthotopic implantation of OCUM-2M cells which developed no peritoneal metastasis after intraperitoneal inoculation. The histologic findings of orthotopic-implanted tumor in the stomach show scirrhous type while those of subcutaneous-implanted tumor show medullary type. There might be factors, in OCUM-2MD3 cells, which are responsible for peritoneal metastasis. We next investigated the differences in the biological behavior of the original OCUM-2M and the derived variant OCUM-2MD3. Morphology and growth activity of the two cell lines were similar to each other. The specific chromosomes, add(6)(g13), del(7)(q21.2) and inv(11)(pl3q21), were found in OCUM-2MD3 cells but not in OCUM-2M cells. While the oncogenes amplification by OCUM-2M cells was found in K-sam and c-myc, that by OCUM-2MD3 cells was found only in c-myc. The expression of E-cadherin by OCUM-2MD3 cells was decreased compared with that of OCUM-2M cells. Expression level of β1-integrin of OCUM-2MD3 cells was higher than that of OCUM-2M cells. The binding and invasion activity of OCUM-2MD3 cells were higher than those of OCUM-2M cells, and were decreased by anti-β1-integrin antibody. The invasion activity of OCUM-2MD3 cells was increased in the presence of peritoneal fibroblast. In this study, it was suggested that orthotopic implantation of cancer cells might have an effect on the acquisition of metastatic ability. β1-integrin and peritoneal fibroblasts might be correlated with peritoneal metastasis. This peritoneal-metastatic model should be useful for analysing the mechanism of peritoneal metastasis of human scirrhous gastric cancer.     

Reduced angiogenesis in peritoneal dissemination of gastric cancer through gelatinase inhibition

Marimastat is a broad-spectrum matrix metalloproteinase (MMP) inhibitor that inhibits almost all major MMPs, key enzymes in gastric cancer invasion and metastasis. We investigated the ability of marimastat to inhibit tumor angiogenesis in the severe combined immuno-deficient (SCID) mouse/human gastric cancer model of peritoneal dissemination. A human stomach adenocarcinoma cell line, TMK-1, was injected intraperitoneally into SCID mice. On the 7th day after tumor inoculation, the administration of marimastat (27 mg/kg/day) was initiated and the treatment was continued for 2 weeks using subcutaneously-inoculating mini-osmotic pumps. On the 21st day, the mice were killed and the disseminated nodules were evaluated. Total weights, numbers, and the microvascular density of the disseminating nodules were significantly lower in mice treated with marimastat compared to the control group. Film in situ zymography demonstrated that net gelatinolytic activity in the tissues was weaker in treated-group nodules than in control-group nodules. Thus, our results suggested that marimastat inhibited peritoneal dissemination of human gastric cancer cells through inhibition of tumor angiogenesis, possibly involving the down-regulation of gelatinases, in SCID mice injected with human gastric cancer cells. This revised version was published online in July 2006 with corrections to the Cover Date.     

Human peritoneal mesothelial cell transformation into myofibroblasts in response to TGF-ß1 in vitro

Peritoneal dissemination is one of the leading causes of death in gastric cancer patients. The interaction between carcinoma cells and the peritoneal lining may play a key role in tumor peritoneal dissemination. Human peritoneal mesothelial cells are a monolayer of squamous epithelial cells covering the peritoneal cavity and forming serosal membranes. The precise role of mesothelial cells in the peritoneal dissemination of gastric cancer remains to be identified. Expression of TGF-?1, a cytokine known for its capacity to induce proliferative and transformative changes in cells, has been correlated with peritoneal metastasis and TNM stages of gastric cancer. High levels of TGF-?1 in the subperitoneal milieu may play a key role in the transition of normal mesothelial cells to myofibroblasts. Here, we demonstrate that mesothelial cells activated by TGF-?1 undergo epithelial-mesenchymal transition (EMT) and that the transition of mesothelial cells to myofibroblasts is dependent on Smad2 signaling. EMT of mesothelial cells was marked by up-regulation of α-smooth muscle actin and vimentin expression. Cytokeratin and E-cadherin expression decreased over time in transformed mesothelial cells. Knockdown of Smad2 gene by siRNA silencing significantly suppressed the transition of mesothelial cells to myofibroblasts. We conclude that when exposed to TGF-?1 mesothelial cells undergo EMT which involves Smad2 signaling. Furthermore, mesothelial cells may be the possible source of myofibroblasts in peritoneal fibrosis and provide a favorable environment for the dissemination of gastric cancer.     

裸小鼠原位移植筛选高转移性人骨肉瘤细胞系及其生物学特性分析

目的　在裸小鼠体内筛选人骨肉瘤高肺转移性细胞亚群 ,为实验研究提供模型。方法　利用原位移植方法 ,将人骨肉瘤细胞系SOSP 96 0 7皮下移植瘤接种于裸鼠胫骨骨髓腔。筛选到第 2代时 ,有 1例发生肺转移 ;以皮下扩增转移灶 ,再次原位移植 ,第 3代肺转移率达 83% ( 5 / 6 )。用组织块法培养收集 ,比较其与母系在形态结构、细胞核型 ,vimentin ,actin ,NSE抗原表达及体积倍增时间等方面的差别。结果　同母系相比较 ,该转移细胞保持了人骨肉瘤细胞的组织学特征 ,生物学特性也有较大差别。结论　该细胞亚群是一株新建立的人骨肉瘤细胞高转移性亚系     

右旋柠烯乳剂对人胃癌移植瘤生长和转移的抑制作用

目的　研究并探讨右旋柠烯乳剂 (D limonene)对人胃癌生长和转移的抑制作用及其机制。　方法　采用人胃癌BGC 82 3细胞株经反复传代成实体瘤的完整组织块 ,建立人胃癌裸小鼠原位移植瘤模型。将 4 0只荷瘤裸小鼠随机分成 4组 ,移植后第 5d开始分别用生理盐水灌胃、5 氟尿嘧啶 (5 FU)腹腔注射、D limonene灌胃、D limonene灌胃 +5 FU腹腔注射共 7周。第 8周处死动物 ,测量原位肿瘤瘤重并计算抑瘤率 ,检测肿瘤细胞凋亡指数 (AI)、肿瘤微血管密度 (MVD)及免疫组织化学测定肿瘤组织血管内皮生长因子 (VEGF)的表达变化 ,光镜与电镜观察组织细胞超微结构变化 ;观察荷瘤鼠腹膜、肝、其他脏器肿瘤转移及腹水情况。　结果　D limonene组、联用组分别与对照组相比 ,胃癌的原位肿瘤瘤重与抑瘤率、AI、MVD、VEGF下调 ,差异有显著性 (P <0 0 5 )。腹膜、肝转移受到明显抑制 (P <0 0 5 )。　结论　D limonene通过抑制肿瘤微血管形成 ,诱导胃癌细胞凋亡 ,抑制了体内胃癌的生长和转移。     

High collagenolytic activity in spontaneously highly metastatic variants derived from a human pancreatic cancer cell line (SUIT-2) in nude mice

Cell lines with high metastatic capacity to the lung were established by sequential passage of a human pancreatic cancer cell line (SUIT-2) through the lung of a nude mouse, via the lateral tail vein and from a subcutaneous inoculum. Cells of the parental SUIT-2 and sublines S2-VPx (x-cycle selection from SUIT-2 cells, by Vein-Pulmonary metastasis-culture) and S2-CPx (x-cycle selection, by Cutis-Pulmonary metastasis-culture) were injected intravenously or subcutaneously into nude mice to produce experimental or spontaneous lung metastasis. The S2-VP10 cell line produced pulmonary metastases in 100% of the nude mice, when injected intravenously. It failed, however, to produce more lung colonies than its parent cell line, when injected subcutaneously. The S2-CP8 cell line produced extensive pulmonary metastases in 100% of the nude mice, when injected either intravenously or subcutaneously. This study indicates that the nude mouse provided a good model for in vivo selection of metastatic cells from SUIT-2 cells both experimentally and spontaneously, and that the SUIT-2, S2-VPx, and S2-CPx cell lines will be valuable in the study of human cancer metastasis. We previously reported high levels of ezrin expression in the S2-VP10 and S2-CP8 cell lines. Here we show that these cell lines exhibit a greater capacity to invade or attach to various extracellular matrix components than the parent SUIT-2 cells. The S2-CP8 cell lines also exhibit greater level of type-I and type-IV collagen-degrading activity than the parent SUIT-2 cell line and the S2-VP10 cell line, which shows similar collagen-degrading activity to the parent SUIT-2 cells. In RT-PCR studies, SUIT-2, S2-CP8 and S2-VP10 cell lines constitutively expressed many matrix metalloproteinases (MMP-1, MMP-2, MMP-3, MMP7, MMP-9, MMP-10 and MMP-14). These results suggest that some parameters that enhance adhesion and invasion are important to both experimental and spontaneous metastasis and the collagen degrading enzymes are predicted to play a key-role during spontaneous metastasis. This revised version was published online in July 2006 with corrections to the Cover Date.     

Organ-specific growth of a murine lymphoma of spontaneous origin in nude mice

The MOC-25 tumour arose spontaneously in a female nude mouse and was established as a continuous line intraperitoneally in nude mice, where it reproduces the topological features of its origin, growing preferentially in the uterus, ovaries and liver. Karyotype analysis showed that MOC-25 cells are hyperdiploid. Tumorigenicity and malignant behaviour were studied by transplanting tumour cells into different sites in nude mice. The comparison of tumour take after i.p. and s.c. injections of scaled concentrations of MOC-25 cell suspension showed preferential growth in the peritoneum. Regardless of the route of implantation (s.c., i.v., i.p.), this tumour rapidly and preferentially disseminated to the liver, uterus, ovaries, spleen and bone marrow. No significant differences in tumour growth and metastatic behaviour were observed when MOC-25 was injected in ovariectomized nude mice or in male nude mice. Morphology studies using light and electron microscopy, immunophenotyping and molecular analysis indicated a B-lymphoid origin of the MOC-25 tumour.     

Carcinoma‐associated fibroblasts derive from mesothelial cells via mesothelial‐to‐mesenchymal transition in peritoneal metastasis

Peritoneal dissemination is a frequent metastatic route for cancers of the ovary and gastrointestinal tract. Tumour cells metastasize by attaching to and invading through the mesothelial cell (MC) monolayer that lines the peritoneal cavity. Metastases are influenced by carcinoma‐associated fibroblasts (CAFs), a cell population that derives from different sources. Hence, we investigated whether MCs, through mesothelial–mesenchymal transition (MMT), were a source of CAFs during peritoneal carcinomatosis and whether MMT affected the adhesion and invasion of tumour cells. Biopsies from patients with peritoneal dissemination revealed the presence of myofibroblasts expressing mesothelial markers in the proximity of carcinoma implants. Prominent new vessel formation was observed in the peritoneal areas harbouring tumour cells when compared with tumour‐free regions. The use of a mouse model of peritoneal dissemination confirmed the myofibroblast conversion of MCs and the increase in angiogenesis at places of tumour implants. Treatment of omentum MCs with conditioned media from carcinoma cell cultures resulted in phenotype changes reminiscent of MMT. Adhesion experiments demonstrated that MMT enhanced the binding of cancer cells to MCs in a β1‐integrin‐dependent manner. Scanning electron microscopy imaging showed that the enhanced adhesion was mostly due to increased cell–cell interaction and not to a mere matrix exposure. Invasion assays suggested a reciprocal stimulation of the invasive capacity of tumour cells and MCs. Our results demonstrate that CAFs can derive from mesothelial cells during peritoneal metastasis. We suggest that MMT renders the peritoneum more receptive for tumour cell attachment/invasion and contributes to secondary tumour growth by promoting its vascularization. Copyright © 2013 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.