Inhibition of CD147 expression reduces tumor cell invasion in human prostate cancer cell line via RNA interference

CD147, also named extracelluar matrix metalloproteinase inducer (EMMPRIN), has been proved to be involved in the invasion and metastasis processes of tumor cells in many types of cancers. To determine the role of CD147 in the invasiveness properties of prostate cancer, we successfully downregulated CD147 by RNA interference (RNAi) technology, in PC-3 cell line at high level of CD147 expression. PC-3 cells were transfected with a pSilencer 4.1-CMV neo Vector coding for an RNA composed of two identical 19-nucleotide sequence motifs in an inverted orientation, separated by a 9-bp spacer to form a hairpin dsRNA capable of mediating target CD147 inhibition. Gelatin zymography was employed to determine the effect on reducing secretions of MMP-2 and MMP-9 of the transfected cells. Matrigel invasion assay was performed to evaluate the invasion ability of PC-3 cells in vitro. Our results showed that CD147 expression was significantly inhibited by small interfering RNAs (siRNA) transfectants in PC-3 cells at mRNA and protein levels, which resulted in dramatic reduction of invasion ability in tumor cells. Moreover, downregulation of CD147 resulted in reducing secretions of MMP-2, MMP-9. Taken together, CD147 downregulation by RNAi technology decreases the invasive capability of prostate cancer cells, demonstrating that stable expression of siRNA CD147 could potentially be an experimental approach for prostate cancer gene therapy.     

Livin促进骨肉瘤细胞增殖和侵袭作用的实验研究

目的：探讨凋亡抑制蛋白（IAP）家族成员Livin基因在骨肉瘤发生发展以及转移中的作用.方法：联合RNA干扰和质粒重组技术构建Livin基因短发夹RNA （shRNA）表达载体,筛选稳定沉默Livin表达的克隆.四甲基偶氮唑蓝法（MTT法）测定细胞增殖状况.划痕实验（Wound healing）和侵袭实验（Matrigel invasion assay）评价沉默Livin表达后细胞迁移和浸润能力的变化.免疫印迹法（Western blot）检测细胞周期蛋白Cyclin D1和基质金属蛋白酶-2,9（MMP-2,9）的蛋白表达变化.结果：shRNA稳定转染的骨肉瘤U2-OS细胞中Livin mRNA和蛋白水平明显下调.与对照组相比,细胞增殖,游走和侵袭能力明显下降,并且该克隆中Cyclin D1,MMP-2和MMP-9的蛋白表达也明显减弱.结论：凋亡抑制蛋白Livin能够在体外条件下促进骨肉瘤细胞增殖和侵袭作用,这一过程可能与Cyclin D1和MMP-2,9的表达增强有关.     

Inhibition of matrix metalloproteinase-9 reduces in vitro invasion and angiogenesis in human microvascular endothelial cells

The expression of matrix metalloproteinases (MMPs), particularly MMP-9, is significantly increased during tumor progression and is thought to play a major role in mediating angiogenic process. Since microvasculature plays an important role in controlling tumor growth, we investigated the effects of MMP-9 inhibition on endothelial cell migration and tube formation, two determinants of angiogenesis. Adenoviral-mediated MMP-9 downregulation inhibited endothelial cell migration in cell wounding and spheroid migration assays. To determine the effects of MMP-9 reduction in glioblastoma/endothelial co-cultures, we used a three-dimensional co-culture assay of glioblastoma spheroids and endothelial spheroids. Untreated controls showed invasion of both cell populations into each other whereas treatment of the co-cultures with adenoviral antisense MMP-9 particles resulted in reduced invasion. Next, inhibition of MMP-9 by adenoviral vectors in endothelial cells was assessed for in vitro capillary-like structure formation either by co-culture with glioblastoma cells or exposure to glioblastoma-conditioned medium. Addition of conditioned medium from human glioblastoma cells to endothelial cells treated with antisense MMP-9 adenoviral vectors or co-cultures of glioblastoma cell lines with MMP-9-reduced endothelial cells resulted in reduced capillary-like tube formation demonstrating the key role of MMP-9 in endothelial cell network organization. Examination of in vitro capillary-like tube structure formation using Matrigel showed a significant decrease in MMP-9 downregulated endothelial cells as compared to controls. In conclusion, the inhibition of MMP-9 is required for inhibition of endothelial cell migration and tube formation and is likely to be of importance in cerebral angiogenesis for therapeutic targets.     

Adenovirus-mediated expression of antisense MMP-9 in glioma cells inhibits tumor growth and invasion

Matrix metalloproteinase 9 (MMP-9) is known to play a major role in cell migration and invasion in both physiological and pathological processes. Our previous work has shown that increased MMP-9 levels are associated with human glioma tumor progression. In this study, we evaluated the ability of an adenovirus containing a 528 bp cDNA sequence in antisense orientation to the 5' end of the human MMP-9 gene (Ad-MMP-9AS) to inhibit the invasiveness and migratory capacity of the human glioblastoma cell line SBN19 in in vitro and in vivo models. Infection of glioma cells with Ad-MMP-9AS reduced MMP-9 enzyme activity by approximately 90% compared with mock- or Ad-CMV-infected cells. Migration and invasion of glioblastoma cells infected with Ad-MMP-9AS were significantly inhibited relative to Ad-CMV-infected controls in spheroid and Matrigel assays. Intracranial injections of SNB19 cells infected with Ad-MMP-9AS did not produce tumors in nude mice. However, injecting the Ad-MMP-9AS construct into subcutaneous U87MG tumors in nude mice caused regression of tumor growth. These results support the theory that adenoviral-mediated delivery of the MMP-9 gene in the antisense orientation has therapeutic potential for treating gliomas.     

The hemopexin domain of MMP-9 inhibits angiogenesis and retards the growth of intracranial glioblastoma xenograft in nude mice

Matrix Metalloproteinase-9 (MMP-9) consists of a prodomain, catalytic domain with 3 fibronectin-like type II modules and C-terminal hemopexin-like (PEX) domain. These domains play distinct roles in terms of proteolytic activity, substrate binding and interaction with inhibitors and receptors. To assess the potential of the MMP-9-PEX domain to interfere with tumor progression, we stably transfected human glioblastoma cells with an expression vector containing a cDNA sequence of the MMP-9-PEX. The selected clones exhibited decreased MMP-9 activity and reduced invasive capacity. We assessed how secretion of MMP-9-PEX by glioblastoma cells affects angiogenic capabilities of human microvascular endothelial cells (HMECs) in vitro. MMP-9-PEX conditioned medium treatment caused a reduction in migration of HMECs and inhibited capillary-like structure formation in association with suppression of vascular endothelial growth factor (VEGF) secretion and VEGF receptor-2 protein level. The suppression of HMECs survival by conditioned medium from MMP-9-PEX stable transfectants was associated with apoptosis induction characterized by an increase in cells with a sub-G0/G1 content, fragmentation of DNA, caspase-3, -8 and -9 activation and poly (ADP-ribose) polymerase (PARP) cleavage. A significant tumor growth inhibition was observed in intracranial implants of MMP-9-PEX stable transfectants in nude mice with attenuation of CD31 and MMP-9 protein expression. These results demonstrate that MMP-9-PEX inhibits angiogenic features of endothelial cells and retards intracranial glioblastoma growth.     

Blockade of cathepsin B expression in human glioblastoma cells is associated with suppression of angiogenesis.

The cysteine proteinase cathepsin B has been implicated in tumor progression by virtue of its increased mRNA and protein levels, as well as its localization at the invading front of the tumor. In this study, we examined whether blocking cathepsin B expression in human glioblastoma SNB19 cells affects angiogenesis. Stable transfectants of human glioblastoma cells with a plasmid containing antisense cathepsin B cDNA showed decreased migration rates in wound- and spheroid-migration assays. Analysis showed a reduction in VEGF protein and MMP-9 activity in the cathepsin B antisense cDNA-transfected cells. Regarding angiogenesis in vitro, we found that the conditioned medium of glioblastoma cells with downregulated cathepsin B expression reduced cell-cell interaction of human microvascular endothelial cells, resulting in the disruption of capillary-like network formation. Furthermore, a marked reduction in microvasculature development was seen in an in vivo dorsal air sac assay of glioblastoma cells with downregulated cathepsin B expression. Taken together, these results provide evidence that inhibition of cathepsin B expression can suppress glioblastoma-induced neovascularization.     

PTEN suppresses hyaluronic acid-induced matrix metalloproteinase-9 expression in U87MG glioblastoma cells through focal adhesion kinase dephosphorylation

Glioblastoma is a severe type of primary brain tumor and its invasion is strongly correlated with the secretion of matrix metalloproteinases (MMPs). To investigate a role of PTEN, a tumor suppressor gene, in the regulation of hyaluronic acid (HA)-induced invasion of glioma cells, we examined the secretion of MMP-9 in various glioma cells with or without a functional PTEN gene. The secretion of MMP-9 in glioma cells lacking functional PTEN (U87MG, U251MG, and U373MG) was induced by HA, although not in wildtype (wt)-PTEN-harboring cells (LN229, LN18, and LN428). In addition, stable expression of wt-PTEN into U87MG cells significantly decreased the secretion of HA-induced MMP-9 and basal levels of MMP-2, inhibiting the activation of focal adhesion kinase and extracellular signal-regulated kinase 1/2, whereas the secretion levels of the tissue inhibitor of metalloproteinase-1 and -2 were increased, finally resulting in the inhibition of invasion by HA in vitro. Ectopic expressions of adenoviral (Ad)-wt-PTEN and -lipid phosphatase-deficient (G129E)-PTEN, but not both protein and -lipid phosphatase-deficient (C124S)-PTEN, reduced MMP-9 secretion and invasion by HA. These results were also confirmed by expressions of Ad-wt-PTEN and Ad-G129E-PTEN in other glioblastoma cells lacking functional PTEN, U251MG, and U373MG. These findings strongly suggest the possibility that PTEN may block HA-induced MMP-9 secretion and invasion through its protein phosphatase activity.     

VHL基因对U251胶质瘤细胞侵袭和迁移的影响

  目的   研究VHL基因对U251胶质瘤细胞侵袭和迁移能力的影响   方法   使用VHL表达质粒转染胶质瘤细胞,采用RT-PCR检测VHL mRNA表达,Western blot检测VHL、MMP-2、MMP-9蛋白表达,应用Transwell体外侵袭实验、划痕实验检测上调VHL基因后对U251胶质瘤细胞侵袭迁移能力的影响。使用VHL表达质粒处理后的U251细胞建立裸鼠颅内模型,利用免疫组织化学染色法对颅内模型组织切片中VHL、MMP-2、MMP-9蛋白表达进行检测。   结果   VHL表达质粒转染胶质瘤细胞后VHL mRNA、VHL蛋白表达增高,MMP-2、MMP-9蛋白表达下降;并抑制U251胶质瘤细胞侵袭迁移能力。对染色后的组织切片进行分析,VHL表达质粒处理组中VHL的表达较对照组明显升高,MMP-2、MMP-9蛋白较对照组表达减少。   结论   VHL基因能够有效抑制U251胶质瘤细胞侵袭迁移能力,VHL基因可成为治疗胶质瘤的一个有效靶点。      

小RNA干扰沉默CD147基因对膀胱癌T-24细胞生物学行为的影响

目的:探讨重组腺病毒介导的小RNA干扰(small interfering RNA,siRNA)沉默CD147基因表达对人膀胱癌T-24细胞增殖、迁移及侵袭能力的影响.方法:构建针对CD147基因的siRNA重组腺病毒表达载体Ad-CD147 siRNA,感染人膀胱癌T-24细胞.实验设空白对照组(Mock)、阴性对照组(Ad-siControl)和干扰组(Ad-CD147 siRNA).采用RT-PCR检测CD147和血管内皮生长因子(vascular endothelial growth factor,VEGF) mRNA的表达水平;蛋白质印迹法检测CD147蛋白的表达水平;MTT法检测细胞增殖的情况,Transwell小室法和划痕实验检测对细胞侵袭和迁移能力的影响;明胶酶谱实验检测基质金属蛋白酶-2(matrix metalloproteinase-2,MMP-2)和MMP-9的分泌情况;ELISA法检测VEGF蛋白分泌水平.结果:成功构建了Ad-CD147 siRNA腺病毒表达载体,Ad-CD147 siRNA可使T-24细胞CD147 mRNA和蛋白表达量下调＞90％(P＜0.01),细胞增殖速率下降＞40％(P＜0.01),细胞侵袭力和迁移力明显下降(P＜0.01),MMP-2和MMP-9的分泌量分别下降了68.5％和37.1％(P＜ 0.01),VEGF mRNA和蛋白表达水平分别下降了57.2％(P＜ 0.01)和56.5％(P＜0.01).结论:Ad-CD147 siRNA能有效抑制T-24细胞中CD147基因的表达,继而降低细胞增殖、迁移及侵袭能力.因此,CD147有可能成为膀胱癌基因治疗的一个新靶点.     

A novel antisense inhibitor of MMP-9 attenuates angiogenesis, human prostate cancer cell invasion and tumorigenicity

Androgen deprivation therapy causes a paradoxical elevation of matrix metalloproteinases (MMPs) including MMP-9 resulting in aggressive tumor phenotype in many patients with prostate cancer. In this study, we have evaluated a novel antisense phosphorodiamidate Morpholino oligomer (PMO) targeted against MMP-9 in models of angiogenesis and in human prostate xenograft in athymic mice. The treatment of androgen-independent DU145 human prostate cells with a 21-mer MMP-9 antisense PMO caused a dose-dependent inhibition of cell proliferation compared to scrambled or MMP-2 antisense PMO at similar concentrations. This was associated with decreases in MMP-9 expression, gelatinolytic activity and increased stability of the insulin-like growth factor-binding protein (IGFBP-3), a proapoptotic factor and MMP-9 substrate. In vitro invasion assays revealed a 40-60% inhibition of DU145 cell invasion in the presence of 25 microM MMP-9 antisense PMO. A significant decrease in endothelial cell migration and vascularization was observed in the Matrigel plug assay in mice when treated intraperitoneally with 300 microg/day MMP-9 antisense for 21 days. In the highly vascular DU145 tumor xenografts, MMP-9 inhibition caused decreased tumor growth with regression in 50% of the animals. Histological analysis revealed increased apoptosis and fibrous tissue deposits in the MMP-9 antisense-treated tumors compared to the scrambled and saline controls. No apparent toxicity or mortality was associated with the MMP-9 PMO treatment. In summary, the MMP-9 antisense PMO inhibited in vitro prostate cancer cell proliferation, invasion and in vivo angiogenesis. These data establish the feasibility of developing a site-directed, nontoxic antisense therapeutic agent for inhibiting local invasion and metastasis.     

RNAi-mediated silencing of CD147 inhibits tumor cell proliferation,invasion and increases chemosensitivity to cisplatin in SGC7901 cells in vitro

Background

CD147 is a widely distributed cell surface glycoprotein that belongs to the Ig superfamily. CD147 has been implicated in numerous physiological and pathological activities. Enriched on the surface of many tumor cells, CD147 promotes tumor growth, invasion, metastasis and angiogenesis and confers resistance to some chemotherapeutic drugs. In this study, we investigated the possible role of CD147 in the progression of gastric cancer.

Methods

Short hairpin RNA (shRNA) expressing vectors targeting CD147 were constructed and transfected into human gastric cancer cells SGC7901 and CD147 expression was monitored by quantitative realtime RT-PCR and Western blot. Cell proliferation, the activities of MMP-2 and MMP-9, the invasive potential and chemosensitivity to cisplatin of SGC7901 cells were determined by MTT, gelatin zymography, Transwell invasion assay and MTT, respectively.

Results

Down-regulation of CD147 by RNAi approach led to decreased cell proliferation, MMP-2 and MMP-9 activities and invasive potential of SGC7901 cells as well as increased chemosensitivity to cisplatin.

Conclusion

CD147 involves in proliferation, invasion and chemosensitivity of human gastric cancer cell line SGC7901, indicating that CD147 may be a promising therapeutic target for gastric cancer.     

Inhibition of cathepsin B and MMP-9 gene expression in glioblastoma cell line via RNA interference reduces tumor cell invasion, tumor growth and angiogenesis

Extracellular proteases have been shown to cooperatively influence matrix degradation and tumor cell invasion through proteolytic cascades, with individual proteases having distinct roles in tumor growth, invasion, migration and angiogenesis. Matrix metalloproteases (MMP)-9 and cathepsin B have been shown to participate in the processes of tumor growth, vascularization and invasion of gliomas. In the present study, we used a cytomegalovirus promoter-driven DNA template approach to induce hairpin RNA (hpRNA)-triggered RNA interference (RNAi) to block MMP-9 and cathepsin B gene expression with a single construct. Transfection of a plasmid vector-expressing double-stranded RNA (dsRNA) for MMP-9 and cathepsin B significantly inhibited MMP-9 and cathepsin B expression and reduced the invasive behavior of SNB19, glioblastoma cell line in Matrigel and spheroid invasion models. Downregulation of MMP-9 and cathepsin B using RNAi in SNB19 cells reduced cell-cell interaction of human microvascular endothelial cells, resulting in the disruption of capillary network formation in both in vitro and in vivo models. Direct intratumoral injections of plasmid DNA expressing hpRNA for MMP-9 and cathepsin B significantly inhibited established glioma tumor growth and invasion in intracranial tumors in vivo. Further intraperitoneal (i.p.) injections of plasmid DNA expressing hpRNA for MMP-9 and cathepsin B completely regressed pre-established tumors for a long time (4 months) without any indication of these tumor cells. For the first time, these observations demonstrate that the simultaneous RNAi-mediated targeting of MMP-9 and cathepsin B has potential application for the treatment of human gliomas.     

Cancer stem-like cells of glioblastoma characteristically express MMP-13 and display highly invasive activity

Glioblastoma is the most malignant type of primary brain tumor that has been shown to contain a small population of cancer stem cells. Recent studies have suggested that cancer stem cells cause tumor recurrence based on their resistance to radiotherapy and chemotherapy. Although the highly invasive nature of glioblastoma cells is also implicated in the failure of current therapies, it is not clear whether cancer stem cells are involved in invasiveness. In this study, we isolated tumor sphere-forming cells bearing cancer stem-like characteristics such as self-renewal, multipotency, drug-resistibility, and in vivo tumorigenicity, from the human glioblastoma cell line U251, under serum-free neural stem cell culture condition, and assessed their migratory and invasive ability. These cells showed enhanced migratory and invasive ability on both Matrigel and organotypic brain slices compared to parental U251 cells. The expression of matrix metalloproteinase (MMP)-13 was specifically expressed in tumor sphere-forming cells derived from U251 and primary human glioma cells. Knockdown of MMP-13 expression by shRNA suppressed the migration and invasion of these cells. The results suggest that the highly invasive potential of cancer stem cells depends on MMP-13 enzymatic activity, thus MMP-13 might be a potential therapeutic target for glioblastomas.     

Inhibition of CD147 gene expression via RNA interference reduces tumor cell invasion, tumorigenicity and increases chemosensitivity to paclitaxel in HO-8910pm cells

Overexpression of extracellular matrix metalloproteinase inducer (EMMPRIN or CD147), a member of the immunoglobulin family and a glycoprotein enriched on the surface of tumor cells, promotes invasion, metastasis, growth and survival of malignant cells, and confers resistance to some chemotherapeutic drugs. Here, we used a human U6 promoter-driven DNA template approach to induce short hairpin RNA (shRNA)-triggered RNA interference (RNAi) to block CD147 gene expression in the human ovarian cancer cell line HO-8910pm. Knockdown of CD147 by shRNA resulted in decrease of the HO-8910pm invasion activity in vitro and tumorigenicity in nude mice. The suppression of CD147 expression also sensitized cells to be more sensitive to paclitaxel. These results suggested that CD147 was an ovarian cancer-related gene and CD147 might be a potential target for therapeutic anti-cancer drugs.     

siRNA转染U251细胞下调Moesin导致PDGF及CD44表达下降

目的探讨Moeisn蛋白参与影响人脑胶质细胞瘤（U251）细胞生长和侵袭的可能途径。方法以人脑胶质细胞瘤U251细胞系为研究对象,针对Moesin编码基因设计小干扰RNA片段转染入细胞,通过反转录聚合酶链反应(RT-PCR)筛选沉默效率最高的siRNA片段进行后续实验。通过对设计的3组不同干预的U251细胞（空白组、阴性对照组、转染组）进行RT-PCR测定PDGF的表达,以及流式细胞方法测定CD44的含量。结果RT PCR和Western blot筛选出沉默效果最好的Moesin 139片段;RT-PCR发现转染组U251细胞中PDGF的mRNA的平均表达为0.09377±0.008546,远低于空白组（0.4663±0.01844）和阴性对照组（0.4570±0.02159）,其差异有统计学意义（P<0.01）;流式细胞术检测发现转染组中CD44的表达最低为（26.73±2.720）%,与其他两组差异明显（F=173.669,sig=0.000）。结论U251细胞中Moesin表达下降将导致PDGF和CD44的表达同时下降,同时生长和侵袭能力明显下降,提示Moesin可能通过调节PDGF与CD44在人脑胶质瘤细胞的生长、侵袭过程中发挥重要作用,Moesin有可能成为治疗人脑胶质瘤的靶点分子。     

CD147 silencing via RNA interference reduces tumor cell invasion, metastasis and increases chemosensitivity in pancreatic cancer cells

CD147, which belongs to the immunoglobulin superfamily, is a multifunctional glycoprotein that has been shown to increase tumor invasion, metastasis and multidrug resistance. To define the role of CD147 in invasion and metastasis more precisely, we utilized gene silencing to inhibit the expression of CD147 in pancreatic cancer cells. We observed that CD147 expression was significantly impeded at both the mRNA and protein levels and resulted in a decrease of MMP-2 and MMP-9 activities. There was also a decrease of MCT1 expression in the invasion and metastasis potential of pancreatic cancer cells, as well as increased chemosensitivity to gemcitabine in Panc-1 cells. Overall, these results suggest that CD147 plays an important role in the invasion, metastasis and chemosensitivity of the human pancreatic cancer cell line Panc-1, indicating that CD147 may be a promising therapeutic target for pancreatic cancer.     

CD166/Activated leukocyte cell adhesion molecule is expressed on glioblastoma progenitor cells and involved in the regulation of tumor cell invasion

For improvement of prognosis for glioblastoma patients, which remains poor, identification and targeting of glioblastoma progenitor cells are crucial. In this study, we found that the Cluster of Differentiation (CD)166/activated leukocyte cell adhesion molecule (ALCAM) was highly expressed on CD133(+) glioblastoma progenitor cells. ALCAM(+)CD133(+) cells were highly enriched with tumor sphere-initiating cells in vitro. Among gliomas with isocitrate dehydrogenase-1/R132H mutation, the frequencies of ALCAM(+) cells were significantly higher for glioblastomas than for World Health Organization grade II or III gliomas. The function of ALCAM in glioblastoma was then investigated. An in vitro invasion assay showed that transfection of ALCAM small interfering RNA or small hairpin RNA into glioblastoma cells significantly increased cell invasion without affecting cell proliferation. A soluble isoform of ALCAM (sALCAM) was also expressed in all glioblastoma samples and at levels that correlated well with ALCAM expression levels. In vitro invasion of glioblastoma cells was significantly enhanced by administration of purified sALCAM. Furthermore, overexpression of sALCAM in U87MG glioblastoma cells promoted tumor progression in i.c. transplants into immune-deficient mice. In summary, we were able to show that ALCAM constitutes a novel glioblastoma progenitor cell marker. We could also demonstrate that ALCAM and its soluble isoform are involved in the regulation of glioblastoma invasion and progression.