CD147 depletion down-regulates matrix metalloproteinase-11, vascular endothelial growth factor-A expression and the lymphatic metastasis potential of murine hepatocarcinoma Hca-F cells

Extracellular matrix metalloproteinase inducer (EMMPRIN, CD147), which is a plasma membrane glycoprotein enriched on the surface of many malignant tumors promotes adhesion, invasion and metastasis of tumor cells. In addition, tumor-associated CD147 also induces vascular endothelial growth factors (VEGFs) expression. To investigate the possible role of CD147 in the mouse hepatocarcinoma cell line Hca-F with highly metastatic potential in the lymph nodes, we used an RNA interference (RNAi) approach to silence CD147 expression. The results showed that CD147 depletion in Hca-F cells resulted in the significantly decreased expression of matrix metalloproteinase-11 (MMP-11), VEGF-A at both mRNA and protein levels. The reduced CD147 expression also attenuated the invasive, adhesive, metastatic ability of Hca-F cells to lymph nodes both in vitro and in vivo. Our current findings reveal that the tumor biological marker CD147 functionally mediates MMP-11, VEGF-A expression and tumor lymphatic metastasis.     

Divergent expression and roles for caveolin-1 in mouse hepatocarcinoma cell lines with varying invasive ability

Caveolin-1 is the major component protein of caveolae and associated with a lot of cellular events such as endocytosis, cholesterol homeostasis, signal transduction, and tumorigenesis. The majority of results suggest that caveolin-1 might not only act as a tumor suppressor gene but also a promoting metastasis gene. In this study, the divergent expression and roles of caveolin-1 were investigated in mouse hepatocarcinoma cell lines Hca-F, Hca-P, and Hepa1-6, which have high, low, and no metastatic potential in the lymph nodes, as compared with normal mouse liver cell line IAR-20. The results showed that expression of caveolin-1 mRNA and protein along with the amount of caveolae number in Hca-F cells was higher than that in Hca-P cells, but was not detectable in Hepa1-6 cells. When caveolin-1 expression in Hca-F cells was down-regulated by RNAi approach, Hca-F cells proliferation rate in vitro declined and the expression of lymphangiogenic factor VEGFA in Hca-F decreased as well. Furthermore, in vivo implantation assay indicated that reduction of caveolin-1 expression in Hca-F prevented the lymphatic metastasis tumor burden of Hca-F cells in 615 mice. These results suggest that caveolin-1 facilities the lymphatic metastasis ability of mouse hepatocarcinoma cells via regulation tumor cell growth and VEGFA expression.     

siRNA targeted against matrix metalloproteinase 11 inhibits the metastatic capability of murine hepatocarcinoma cell Hca-F to lymph nodes

Matrix metalloproteinase-11 (MMP-11) belongs to the particular member of MMP family, a group of zinc-dependent endopeptidases involved in tumor progression, invasion and metastasis. MMP-11 is strongly expressed in tumor cells and stromal fibroblasts located in the immediate vicinity of tumor. This study investigated the possible role of MMP-11 expression in mouse hepatocarcinoma cell line Hca-F with highly lymphatic metastasis potential by RNA interference (RNAi) approach. The results showed that a small interfering RNA (siRNA) targeted against MMP-11 significantly impeded Hca-F cells proliferation and colony formation in soft agar, as well as resulted in Hca-F cell apoptosis. This reduction of MMP-11 expression also led to the decreased migration and adhesion of Hca-F cells dramatically both in vitro and in vivo. Furthermore, in vivo metastasis assay indicated that down-regulation of MMP-11 expression in Hca-F cells attenuated the metastatic potential of Hca-F cells to peripheral lymph nodes. These data together provide compelling evidence into the function of MMP-11 and suggest that MMP-11 act as a tumor lymphatic metastasis-associated gene, and could represent a new potential target for gene therapy.     

N-acetylglucosaminyltransferase IVa regulates metastatic potential of mouse hepatocarcinoma cells through glycosylation of CD147

N-acetylglucosaminyltransferase (GnT)-IV a is a key enzyme that catalyzes the formation of the GlcNAC β1-4 branch on the core structure of complex N-Glycans, which is the common substrate for other N-acetylglucosaminyltransferases, such as GnT-III and GnT-V. Our recent study indicates that the expression of GnT-IVa in Hca-F cells was much higher than that in Hepa1-6 cells, these two mouse hepatocarcinoma cell lines have high and no metastatic potential in lymph nodes respectively. To investigate the effects of GnT-IVa on the metastasis of hepatocarcinoma, exogenous GnT-IVa was introduced into Hepa1-6 cells, and on the other hand, the expression of GnT-IVa was down-regulated in Hca-F cells. The engineered overexpression of GnT-IVa in Hepa1-6 cells increased the antennary branches of complex N-glycans and reduced bisecting branches in vitro and in vivo, which leads to the increase in migration and metastatic capability of hepatocarcinoma cells. Conversely, down-regulated expression of GnT-IVa in Hca-F cells showed reduced tetra-antennary branches of N-Glycans, and significantly decreased the migration and metastatic capability. Furthermore, we found that the regulated GnT-IVa converts the heterogeneous N-glycosylated forms of CD147 in Hepa1-6 and Hca-F cells, and significantly changed the antennary oligosaccharide structures on CD147. These results suggest that GnT-IVa could be acting as a key role in migration and metastasis of mouse hepatocarcinoma cells through altering the glycosylation of CD147. These findings should be valuable in delineating the important function of GnT-IVa during the process of hepatocarcinoma growth and metastasis.     

Modification of Glycosylation Mediates the Invasive Properties of Murine Hepatocarcinoma Cell Lines to Lymph Nodes

Among the various posttranslational modification reactions, glycosylation is the most common, and nearly 50% of all known proteins are thought to be glycosylated. In fact, changes in glycosylation readily occur in carcinogenesis, invasion and metastasis. This report investigated the modification of glycosylation mediated the invasive properties of Hca-F and Hca-P murine hepatocarcinoma cell lines, which have high, low metastatic potential in the lymph nodes, respectively. Analysis revealed that the N-glycan composition profiling, expression of glycogenes and lectin binding profiling were different in Hca-F cells, as compared to those in Hca-P cells. Further analysis of the N-glycan regulation by tunicamycin (TM) application or PNGase F treatment in Hca-F cells showed partial inhibition of N-glycan glycosylation and decreased invasion both in vitro and in vivo. We targeted glycogene ST6GAL1, which was expressed differently in Hca-F and Hca-P cells, and regulated the expression of ST6GAL1. The altered levels of ST6GAL1 were also responsible for changed invasive properties of Hca-F and Hca-P cells both in vitro and in vivo. These findings indicate a role for glycosylation modification as a mediator of tumor lymphatic metastasis, with its altered expression causing an invasive ability differentially.     

Functional expression of CXC chemokine recepter-4 mediates the secretion of matrix metalloproteinases from mouse hepatocarcinoma cell lines with different lymphatic metastasis ability

CXC chemokine recepter-4 (CXCR4) and its ligand, stromal cell-derived factor-1alpha (SDF-1alpha) have been implicated in the organ-specific metastasis of several malignancies. Hca-F and its syngeneic cell line Hca-P are mouse hepatocarcinoma cell lines with high and low potential of lymphatic metastasis, respectively. Previous studies showed that the secretion of matrix metalloproteinases (MMPs) associated with the metastatic ability of Hca-F and Hca-P cell line depending on the lymph node environment. However, the mechanism of this process has remained unclear. This study investigated the roles of CXCR4 on Hca-F cell and SDF-1alpha of lymph node in lymphatic metastasis. The RT-PCR and Flow cytometry analysis results show that Hca-F cells express higher level CXCR4 mRNA and cell-surface CXCR4 protein, as compared with Hca-P cells. Treatment of recombinant SDF-1alpha proteins induced greater amount of calcium-flux in Hca-F cells than that in Hca-P cells, demonstrating higher functional CXCR4 expression on Hca-F cells than that on Hca-P cells. Furthermore, both the cell-free extratcs of lymph node and recombinant SDF-1alpha proteins induced secretions of active MMP-9 and MMP-2 from Hca-F cells in vitro. But those secretions were significantly reduced by blockade of cell surface CXCR4 with rabbit anti-mouse CXCR4 polyclonal antibody (pAb) and neutralization of SDF-1alpha in lymph node extracts with rabbit anti-mouse SDF-1alpha pAb as well. These results suggest that the CXCR4/SDF-1alpha system mediates active MMP-9 and MMP-2 secretion from Hca-F and Hca-P cells, which facilitates lymphogenous metastasis of those cells consequently.     

Guanine nucleotide-binding protein subunit beta-2-like 1, a new Annexin A7 interacting protein

We report for the first time that Guanine nucleotide-binding protein subunit beta-2-like 1 (RACK1) formed a complex with Annexin A7. Hca-F and Hca-P are a pair of syngeneic mouse hepatocarcinoma cell lines established and maintained in our laboratory. Our previous study showed that both Annexin A7 and RACK1 were expressed higher in Hca-F (lymph node metastasis >70%) than Hca-P (lymph node metastasis <30%). Suppression of Annexin A7 expression in Hca-F cells induced decreased migration and invasion ability. In this study, knockdown of RACK1 by RNA interference (RNAi) had the same impact on metastasis potential of Hca-F cells as Annexin A7 down-regulation. Furthermore, by co-immunoprecipitation and double immunofluorescence confocal imaging, we found that RACK1 was in complex with Annexin A7 in control cells, but not in the RACK1-down-regulated cells, indicating the abolishment of RACK1-Annexin A7 interaction in Hca-F cells by RACK1 RNAi. Taken together, these results suggest that RACK1-Annexin A7 interaction may be one of the means by which RACK1 and Annexin A7 influence the metastasis potential of mouse hepatocarcinoma cells in vitro.     

Behavior of metastatic and nonmetastatic breast tumors in old mice

Breast cancer incidence and mortality increase with age. A better understanding of the biological behavior of metastatic and nonmetastatic breast tumors in older subjects may help to develop improved breast cancer therapies. In this study, we used syngeneic metastatic (4TO7cg) and nonmetastatic (64pT) mouse breast tumor models at three age levels to evaluate various characteristics that are considered to be important for effective anti-breast cancer immunotherapy. These included tumor size and growth, metastases, vascularization, gene expression levels of the tumor-associated antigen (TAA) Mage-b (homologous to human MAGE-B) in primary breast tumors and metastases, and the presence of CD4(+) and CD8(+) T cells in the inguinal lymph nodes at the site of the tumor. The primary breast tumors and metastases were generated by injection of mouse mammary tumor cell lines 4TO7cg or 64pT into a mammary fat pad of normal 3-, 9-, or 21/24-month old BALB/c mice. In the nonmetastatic breast tumor model, significantly smaller tumors were observed in old compared with young mice. This was associated with a significant increase in the percentage of CD8(+) T cells in inguinal lymph nodes and significantly higher Mage-b expression levels in the primary tumors at old age. In the metastatic (4TO7cg) breast tumor model, a less pronounced, not statistically significant, smaller tumor size was found in the old mice, without a difference in the percentage of CD8(+) T cells or Mage-b expression levels. However, in this mouse model almost all metastases showed high levels of Mage-b expression (2- to 3-fold higher than the primary tumors in the same animals) regardless of age. These results indicate that the metastatic and nonmetastatic breast tumor models could be useful model systems to analyze how breast cancer vaccines for humans can be tailored to old age.     

Sulfatase-1 knockdown promotes in vitro and in vivo aggressive behavior of murine hepatocarcinoma Hca-P cells through up-regulation of mesothelin

Our previous study (Oncotarget 2016; 7:46) demonstrated that the over-expression of sulfatase-1 in murine hepatocarcinoma Hca-F cell line (a murine HCC cell with lymph node metastatic [LNM] rate of >75%) downregulates mesothelin and leads to reduction in lymphatic metastasis, both in vitro and in vivo. In current work, we investigated the effects of Sulf-1 knockdown on mesothelin (Msln) and it’s effects on the in vitro cell proliferation, migration, invasion, and in vivo tumor growth and LNM rate for Hca-P cells (a murine HCC cell with LNM rate of <25%). Western blotting and qRT-PCR assay indicated that both in vitro and in vivo Sulf-1 was down-regulated by 75% and 68% and led to up regulation of Msln by 55% in shRNA-transfected-Sulf-1-Hca-P cells compared with Hca-P and nonspecific sequence control plasmid transfected Hca-P cell (shRNA-Nc-Hca-P). The in vitro proliferation, migration and invasion potentials were significantly enhanced following Sulf-1 stable down-regulation. In addition, Sulf-1 knock-down significantly promoted tumor growth and increased LNM rates of shRNA-Sulf-1-Hca-P-transplanted mice by 78.6% (11 out of 14 lymph nodes were positive of cancer). Consistent with our previous work, we confirmed that Sulf-1 plays an important role in hepatocarcinoma cell proliferation, migration, invasion and metastasis. The interaction between Sulf-1 and Msln is a potential therapeutic target in the development of liver cancer therapy.     

Caveolin-1 up-regulates CD147 glycosylation and the invasive capability of murine hepatocarcinoma cell lines

CD147 which is a regulator of matrix metalloproteinase (MMP) production on the surface of many malignant tumor cells, shows a highly specific association with caveolin-1 (Cav-1). As a result of heterogeneous N-glycosylation, CD147 exists in both highly glycosylated form, HG-CD147 ( approximately 40-60kDa) and lowly glycosylated form, LG-CD147 ( approximately 32kDa). This study investigated the possible role of Cav-1 in CD147 glycosylation in the HcaF, HcaP and Hepa1-6 mouse hepatocarcinoma cell lines, which have high, low and no metastatic potential in the lymph nodes, respectively, and in the normal mouse liver cell line IAR-20. Using an RNA interference (RNAi) strategy, we showed that the down-regulation of Cav-1 in Hca-F/RNAi cells could suppress the conversion of LG-CD147 to HG-CD147, down-regulate MMP-11 expression and decrease Hca-F/RNAi cell invasion. Conversely, a stable high expression of Cav-1 in Hepa1-6/Cav-1 cell could cause a specific increase of HG-CD147, up-regulate MMP-11 protein expression and enhance Hepa1-6/Cav-1 cell invasion. In conclusion, Cav-1 expression leads to an increased proportion of HG-CD147 relative to LG-CD147, increased production of MMP-11 and a higher invasive capability. Cav-1 is therefore proposed to act as both an oncogene and a tumor suppressor gene, and could represent a new potential target for gene therapy.     

PRC2/EED-EZH2 Complex Is Up-Regulated in Breast Cancer Lymph Node Metastasis Compared to Primary Tumor and Correlates with Tumor Proliferation In Situ

Background

Lymph node metastasis is a key event in the progression of breast cancer. Therefore it is important to understand the underlying mechanisms which facilitate regional lymph node metastatic progression.

Methodology/Principal Findings

We performed gene expression profiling of purified tumor cells from human breast tumor and lymph node metastasis. By microarray network analysis, we found an increased expression of polycomb repression complex 2 (PRC2) core subunits EED and EZH2 in lymph node metastatic tumor cells over primary tumor cells which were validated through real-time PCR. Additionally, immunohistochemical (IHC) staining and quantitative image analysis of whole tissue sections showed a significant increase of EZH2 expressing tumor cells in lymph nodes over paired primary breast tumors, which strongly correlated with tumor cell proliferation in situ. We further explored the mechanisms of PRC2 gene up-regulation in metastatic tumor cells and found up-regulation of E2F genes, MYC targets and down-regulation of tumor suppressor gene E-cadherin targets in lymph node metastasis through GSEA analyses. Using IHC, the expression of potential EZH2 target, E-cadherin was examined in paired primary/lymph node samples and was found to be significantly decreased in lymph node metastases over paired primary tumors.

Conclusions/Significance

This study identified an over expression of the epigenetic silencing complex PRC2/EED-EZH2 in breast cancer lymph node metastasis as compared to primary tumor and its positive association with tumor cell proliferation in situ. Concurrently, PRC2 target protein E-cadherin was significant decreased in lymph node metastases, suggesting PRC2 promotes epithelial mesenchymal transition (EMT) in lymph node metastatic process through repression of E-cadherin. These results indicate that epigenetic regulation mediated by PRC2 proteins may provide additional advantage for the outgrowth of metastatic tumor cells in lymph nodes. This opens up epigenetic drug development possibilities for the treatment and prevention of lymph node metastasis in breast cancer.     

Involvement of an autocrine stromal cell derived factor-1/CXCR4 system on the distant metastasis of human oral squamous cell carcinoma

We have previously shown that a stromal cell-derived factor-1 (SDF-1; CXCL12)/CXCR4 system is involved in the establishment of lymph node metastasis, but not in that of distant metastasis, in oral squamous cell carcinoma (SCC). In this study, we investigated the role of the autocrine SDF-1/CXCR4 system, with a focus on distant metastasis in oral SCC cells. The immunohistochemical staining of SDF-1 and CXCR4 using primary oral SCCs and metastatic lymph nodes showed a significantly higher number of SDF-1-positive cases among the metastatic lymph nodes than among the primary oral SCCs, which was associated with a poor survival rate among those of the former group. The forced expression of SDF-1 in B88 cells, which exhibit functional CXCR4 and lymph node metastatic potential (i.e., the autocrine SDF-1/CXCR4 system), conferred enhanced cell motility and anchorage-independent growth potential onto the cells. Orthotopic inoculation of the transfectant into nude mice was associated with an increase in the number of metastatic lymph nodes and more aggressive metastatic foci in the lymph nodes. Furthermore, the SDF-1 transfectant (i.e., the autocrine SDF-1/CXCR4 system) exhibited dramatic metastasis to the lung after i.v. inoculation, whereas the mock transfectant (i.e., the paracrine SDF-1/CXCR4 system) did not. Under the present conditions, AMD3100, a CXCR4 antagonist, significantly inhibited the lung metastasis of the SDF-1 transfectant, ameliorated body weight loss, and improved the survival rate of tumor-bearing nude mice. These results suggested that, in cases of oral SCC, the paracrine SDF-1/CXCR4 system potentiates lymph node metastasis, but distant metastasis might require the autocrine SDF-1/CXCR4 system.     

CD147 regulates vascular endothelial growth factor-A expression, tumorigenicity, and chemosensitivity to curcumin in hepatocellular carcinoma

CD147, also named as extracelluar matrix metalloproteinase inducer (EMMPRIN), has been proved to be involved in several aspects of tumor progression. In addition to its ability to induce vascular endothelial growth factor (VEGF) production, it confers resistance to some chemotherapeutic drugs. To investigate the possible role of CD147 in the mouse hepatocarcinoma cell line Hepa1-6 with no metastatic potential in the lymph nodes, we used RNA interference (RNAi) approach to silence CD147 expression. The results showed that silencing of CD147 in Hepa1-6 cells significantly impeded the expression of VEGF-A at both mRNA and protein levels. The siRNA-treated cells exhibited significantly decreased growth ability when compared with control cells. Colony formation of CD147 deficient cells was dramatically inhibited in soft agar, and tumorigenicity was reduced in nude mice. Furthermore, the downregulation of CD147 expression also sensitized cells to be more sensitive to curcumin. These results suggested that CD147 might be a potential target for therapeutic antitumor drugs.     

Caveolin一1真核表达载体的构建及其在Hepal-6细胞中的表达

Caveolin-1在不同肿瘤中发挥作用不同,既发挥抑癌基因样作用又发挥癌基因样作用。旨在分析caveolin-l在小鼠肝癌细胞系中的表达情况及建立稳定表达外源caveolin-1的Hepal-6细胞。利用RT-PCR和Western-blot方法检测caveolin-1在小鼠肝癌H22、Hca-F和Hepal-6细胞中的表达;通过分子克隆构建小鼠caveolin-1 cDNA真核表达载体,利用脂质体转染等方法建立稳定表达外源caveolin-1的Hepal-6细胞株;通过RT-PCR、Western-blot、免疫细胞化学等方法鉴定其稳定表达细胞株。结果显示,caveolin-l在Hepal-6细胞中表达呈阴性,在H22和Hca-F中高表达;成功获得小鼠caveolin-1 cDNA真核表达载体pEGFP-N2／Cav-1,筛选并鉴定出高表达外源caveolin-1的Hepal-6稳定细胞株Cl和C4,为进一步分析caveolin-1在肝癌中所发挥的作用奠定了一定的研究基础。     

IL-10 promotes resistance to apoptosis and metastatic potential in lung tumor cell lines

Treatment of non-small cell lung carcinoma (NSCLC) remains at a disappointingly low success rate. Not only is metastatic spread common in NSCLC, but therapeutic success decreases dramatically once metastases are present. Understanding factors which contribute to poor prognosis in NSCLC is critical for development of more successful therapeutic approaches. Interleukin-10 (IL-10) expression has been shown in several studies to correlate with a poorer prognosis in NSCLC; however, the mechanisms by which IL-10 affects lung tumor growth and metastases are unclear. The goal of this study was to evaluate the effects of tumor-derived IL-10 on the growth and metastasis of lung cancer cells in a murine model. Lewis lung carcinoma cells were stably transfected with the chicken ovalbumin gene (cOVA) as a model tumor antigen (LL43 tumor cells) and subsequently transfected with the murine IL-10 gene (LL43-10 tumor cells). Subcutaneous growth of the LL43 tumor cells was not affected by expression of IL-10. However, LL43-10 tumors had a fourfold increase in tumor microvessel density, as indicated by CD31 staining. Metastatic potential was also increased in IL-10-expressing lung tumor cells, leading to a greater number of tumor cells in lymph nodes draining the primary tumor site. Finally, exposure of Lewis lung tumor cells in vitro to exogenous IL-10 dramatically increased their resistance to UV-induced apoptosis. These results indicate that a primary effect of IL-10 on lung cancer cells may be to increase their metastatic potential by promoting angiogenesis and resistance to apoptosis.     

Curcumin inhibits the migration and invasion of mouse hepatoma Hca-F cells through down-regulating caveolin-1 expression and epidermal growth factor receptor signaling

Mouse hepatoma cellular carinoma cell line (Hca-F) cells have highly invasive and lymphatic metastasis potential in vitro and in vivo. Curcumin (diferuloylmethane) is an active component of the spice turmeric and has a diversity of antitumor activities. However, there is no available information to address the effects of curcumin on migration and invasion of mouse hepatoma Hca-F cells. In this study, we found that curcumin exerted a concentration- and time-dependent inhibitory effect on the migration and invasion of Hca-F cells in vitro. Curcumin inhibited the expression of the tumor promoter caveolin-1 (Cav-1) in Hca-F cells. Up-regulation of Cav-1 expression by pcDNA3.1/Cav-1 plasmid was able to reverse the curcumin-induced antimigration and anti-invasion effects in vitro. Curcumin down-regulated the expression of cluster of differntiation (CD)147, matrix metalloproteinase 2, and matrix metalloproteinase 9 and inhibited the phosphorylation of epidermal growth factor receptor (EGFR), the phosphoinositilde 3-kinase (PI3K)/protein kinase B (Akt), p38 mitogen-activated protein kinase (MAPK), and p44/42MAPK in Hca-F cells. Taken together, our findings suggest that curcumin can suppress the migratory and invasive ability of mouse hepatoma Hca-F cells, and this action is mediated through a novel mechanism involving inactivation of Cav-1 and EGFR signaling pathways.     

Let-7c inhibits metastatic ability of mouse hepatocarcinoma cells via targeting mannoside acetylglucosaminyltransferase 4 isoenzyme A

Aberrant glycosylation may promote tumor invasion and metastasis. To investigate whether microRNA (miRNA) is involved in glycosylation-related metastasis, we examined the role of let-7c, a well-known tumor-suppressor miRNA, in glycosylation in murine hepatocarcinoma cell lines Hca-F and Hca-P. We found that let-7c level was higher in Hca-P cells (with lower lymphatic metastasis potential) than in Hca-F cells (with higher lymphatic metastasis potential). Overexpression of let-7c decreased hyper-N-glycosylation of Hca-F cells and repressed their metastatic and invasive ability. Mannoside acetylglucosaminyltransferase 4, isoenzyme A (Mgat4a) is a key glycosyltransferase in the pathway of synthesizing complex N-glycans. Bioinformatics analysis indicates that Mgat4a may be a target of let-7c, which has been verified by dual-luciferase reporter gene assay. Furthermore, the anti-metastatic effect of overexpressed let-7c is similar to that of Mgat4a siRNAs transfection. Hence, our results suggest that let-7c may inhibit the metastatic ability of Hca-F cells, at least partially, via repressing Mgat4a activity.     

nm23-H1-GFP融合蛋白在人肺癌细胞株中的表达及其对肿瘤细胞体外侵袭能力的影响

研究 nm2 3- H1在肿瘤细胞中的定位及其对肿瘤细胞体外侵袭能力的影响 .用 RT- PCR方法检测人高和低转移肺巨细胞癌细胞株 95 D和 95 C中 nm2 3- H1的表达 ;利用分子克隆技术构建nm2 3- H1 -绿色荧光蛋白 ( GFP)融合基因表达质粒 ( p NM2 3- GFP) ,经脂质体转染将此质粒导入95 D和 95 C细胞中 ,筛选高荧光强度的克隆 ,用 Boyden小室模型检测其体外侵袭能力的变化 .结果显示 nm2 3- H1在 95 C细胞中的表达比 95 D高 .95 D细胞中表达的 nm2 3- H1 c DNA未发生突变 .表达的 nm2 3- H1 - GFP融合蛋白位于细胞的胞浆近胞膜处 .转染 p NM2 3- GFP质粒的 95 D和 95 C细胞体外侵袭能力明显比对照组低 .这些提示 nm2 3- H1高表达能明显降低肿瘤细胞体外侵袭能力 .     

Vascular endothelial growth factor-D is a key molecule that enhances lymphatic metastasis of soft tissue sarcomas

Studies on lymph node metastasis of soft tissue sarcomas are insufficient because of its rarity. In this study, we examined the expressions of vascular endothelial growth factor (VEGF)-C and VEGF-D in soft tissue sarcomas metastasized to lymph nodes. In addition, the effects of the two molecules on the barrier function of a lymphatic endothelial cell monolayer against sarcoma cells were analyzed. We examined 7 patients who had soft tissue sarcomas with lymph node metastases and who had undergone neither chemotherapy nor radiotherapy before lymphadenectomy. Immunohistochemistry revealed that 2 of 7 sarcomas that metastasized to lymph nodes expressed VEGF-C both in primary and metastatic lesions. On the other hand, VEGF-D expression was detected in 4 of 7 primary and 7 of 7 metastatic lesions, respectively. Interestingly, 3 cases that showed no VEGF-D expression at primary sites expressed VEGF-D in metastatic lesions. Recombinant VEGF-C at 10(-8) and VEGF-D at 10(-7)and 10(-8)g/ml significantly increased the random motility of lymphatic endothelial cells compared with controls. VEGF-D significantly increased the migration of sarcoma cells through lymphatic endothelial monolayers. The fact that VEGF-D induced the migration of fibrosarcomas through the lymphatic endothelial monolayer is the probable reason for the strong relationship between VEGF-D expression and lymph node metastasis in soft tissue sarcomas. The important propensities of this molecule for the increase of lymph node metastases are not only lymphangiogenesis but also down-regulation of the barrier function of lymphatic endothelial monolayers, which facilitates sarcoma cells entering the lymphatic circulation.     

人EGFR显性负性突变体对胃癌细胞体内成瘤及淋巴结转移的影响

为了研究人表皮生长因子显性负性突变体(dominant negative mutant of EGFR, dnEGFR)对胃癌细胞体内成瘤及淋巴结转移的影响,用目的质粒pEGFPN1 dnEGFR,空质粒载体pEGFP N1分别转染胃癌细胞NCI-N87.筛选出稳定转染株,实验共分3组：NCI-N87细胞未转染组（untreated NCI-N87,UN组）,NCI-N87细胞pEGFP-N1转染组（EN组）;NCI-N87细胞pEGFPN1-dnEGFR转染组（DN组）.将3组细胞接种于裸鼠右后足垫,6周后测量移植瘤大小及对应腹股沟转移淋巴结数目,HE染色验证,real-time PCR和Western 印迹检测3组细胞中AKT1、MAPK3 mRNA和蛋白的表达改变.结果发现,DN组移植瘤较UN、EN组明显缩小（P<0.05）,且右腹股沟转移淋巴结数目较UN、EN组减少（P<0.05）.DN组细胞中,AKT1、MAPK3 mRNA和蛋白水平较UN、EN组降低（P<0.05）.提示pEGFPN1-dnEGFR可抑制裸鼠体内胃癌细胞成瘤及淋巴结转移,AKT1及MAPK3信号通路可能参与其中.