Liver X receptor α (LXRα) promoted invasion and EMT of gastric cancer cells by regulation of NF-κB activity

Aberrant expression of Liver X receptor α (LXRα) has been frequently reported in various types of cancers excluding gastric cancer (GC). Moreover, the role of LXRα in human GC has not been previously reported. In this study, we investigated the effect of LXRα down-regulation on invasion and EMT of GC. The expression of LXRα in GC cell lines was detected by real-time PCR. The LXRα siRNA was transiently transfected into GC cells using Lipofectamine? 2000 reagent. Subsequently, cell invasive ability was evaluated by Transwell assays. Western blot and real-time PCR were used to determined the expressions of matrix metalloproteinase-2 and -9 (MMP-2 and -9), E-cadherin, N-cadherin, Vimentin, Snail, Slug, and Twist in GC cells. In addition, the effect of LXRα down-regulation on the phosphoinositide 3-kinase (PI3K)/Akt/nuclear factor (NF)-κB signaling pathway was explored by Western blot. From our results, we found that the expression of LXRα was significantly increased in GC tissues and cell lines. Knockdown of LXRα suppressed the invasive ability of GC cells. The levels of MMP-2 and -9 were dramatically decreased by down-regulating LXRα. In addition, we found a decrease of N-cadherin, Twist, and Slug expressions and an increase of E-cadherin expression, but no influence on the expression levels of Vimentin and Snail. We also found that LXRα down-regulation might suppress the phosphorylation of Akt, NF-κB, and IκB. Collectively, our results indicated that down-regulation of LXRα was shown to suppress invasion and EMT of GC cells by decreasing the expressions of related proteins through inhibiting the PI3K/Akt/NF-κB signaling pathway.     

Linoleic acid induces an EMT-like process in mammary epithelial cells MCF10A

Epidemiological studies and animal models suggest an association between high levels of dietary fat intake and an increased risk of developing breast cancer. Epithelial-mesenchymal-transition (EMT) is a process, by which epithelial cells are transdifferentiated to a mesenchymal state, and it has been implicated in cancer progression, including invasion and metastasis. Linoleic acid (LA) induces proliferation and invasion in breast cancer cells. However, the role of LA on the EMT process in human mammary epithelial cells remains to be studied. In the present study, we demonstrate that LA induces a transient down-regulation of E-cadherin expression, accompanied with an increase of Snail1, Snail2, Twist1, Twist2 and Sip1 expressions. Furthermore, LA induces FAK and NFκB activation, MMP-2 and -9 secretions, migration and invasion. In summary, our findings demonstrate, for the first time, that LA promotes an EMT-like process in MCF10A human mammary epithelial cells.     

The Significance of Notch1 Compared with Notch3 in High Metastasis and Poor Overall Survival in Hepatocellular Carcinoma

Background

The prognosis for patients with hepatocellular carcinoma (HCC) is poor, and the mechanisms underlying the development of HCC remain unclear. Notch1 and Notch3 may be involved in malignant transformation, although their roles remain unknown.

Materials and Methods

HCC tissues were stained with anti-Notch1 or -Notch3 antibody. The migration and invasion capacities of the cells were measured with transwell cell culture chambers. RT-PCR was used to measure the expression of Notch1 and Notch3 mRNA. Additionally, western blot analysis was used to assess the protein expression of Notch1, Notch3, CD44v6, E-cadherin, matrix metalloproteinase-2 (MMP-2), MMP-9, and urokinase-type plasminogen activator (uPA). RNA interference was used to down-regulate the expression of Notch1 and Notch3. Cell viability was assessed using MTT.

Results

Based on immunohistochemistry, high Notch1 expression was correlated with tumor size, tumor grade, metastasis, venous invasion and AJCC TNM stage. High Notch3 expression was only strongly correlated with metastasis, venous invasion and satellite lesions. Kaplan-Meier curves demonstrated that patients with high Notch1 or Notch3 expression were at a significantly increased risk for shortened survival time. In vitro, the down-regulation of Notch1 decreased the migration and invasion capacities of HCC cells by regulating CD44v6, E-cadherin, MMP-2, MMP-9, and uPA via the COX-2 and ERK1/2 pathways. Down-regulation of Notch3 only decreased the invasion capacity of HCC cells by regulating MMP-2 and MMP-9 via the ERK1/2 pathway.

Conclusions

Based on the migration and invasion of HCC, we hypothesize that targeting Notch1 may be more useful than Notch3 for designing novel preventive and therapeutic strategies for HCC in the near future.     

沉默脂肪细胞增强子结合蛋白2通过PI3K/Akt途径抑制肝癌细胞增殖和迁移

脂肪细胞增强子结合蛋白2(AEBP2)作为多梳抑制复合物2(PRC2)的组成蛋白质,参与多种肿瘤细胞的增殖和迁移,然而其在肝癌中的作用尚不清楚。本研究基于UALCAN和Kaplan-Meier Plotter数据库分析发现,AEBP2在肝癌组织中高表达,并且与患者的不良预后呈正相关。实时荧光定量PCR和蛋白质印迹结果证实,AEBP2在肝癌细胞中的表达高于正常肝细胞。在HepG2和Huh-7细胞中转染AEBP2 siRNA,平板克隆、CCK-8、流式细胞术、划痕愈合和Transwell结果显示,沉默AEBP2可以抑制肝癌细胞增殖、迁移和侵袭,并促进细胞凋亡(P＜0.05)。免疫荧光检测和蛋白质印迹结果显示,沉默AEBP2能够抑制肝癌细胞上皮-间质转化(EMT)(P＜0.05)。生物信息学分析结果表明,AEBP2参与调控PI3K/Akt信号通路。蛋白质印迹结果证实,沉默AEBP2能下调PI3K、p-AKT (S473)、mTOR、MMP-2和MMP-9的蛋白质表达水平(P＜0.05)。此外,沉默AEBP2对HepG2细胞迁移和侵袭的影响可被PI3K/Akt通路激动剂胰岛素样生长因子1(IGF-1)部分逆转(P＜0.01)。综上所述,AEBP2可能通过调节PI3K/Akt途径促进肝癌细胞增殖和迁移。本研究为AEBP2在肝癌中的作用提供理论依据。     

Protocadherin 9 inhibits epithelial–mesenchymal transition and cell migration through activating GSK-3β in hepatocellular carcinoma

Protocadherin 9 (PCDH9) was found frequently lost in hepatocellular carcinoma (HCC). Here we investigated the role of PCDH9 in the development of HCC. We confirmed that PCDH9 was down-regulated in HCC tissues and cell lines compared with the adjacent non-tumor tissues. PCDH9 downregulation was significantly associated with malignant portal vein invasion of HCC patients. Gain- and loss-of-function studies revealed that downregulation of PCDH9 facilitated tumor cell migration and epithelial–mesenchymal transition (EMT). We identified PCDH9 as a novel regulator of EMT by increasing the activity of GSK-3β and inhibiting Snail1, indicating its potential therapeutic value for reducing metastasis of HCC.     

Activation of EGFR promotes squamous carcinoma SCC10A cell migration and invasion via inducing EMT-like phenotype change and MMP-9-mediated degradation of E-cadherin

EGFR is a potent stimulator of invasion and metastasis in head and neck squamous cell carcinomas (HNSCC). However, the mechanism by which EGFR may stimulate tumor cell invasion and metastasis still need to be elucidated. In this study, we showed that activation of EGFR by EGF in HNSCC cell line SCC10A enhanced cell migration and invasion, and induced loss of epitheloid phenotype in parallel with downregulation of E-cadherin and upregulation of N-cadherin and vimentin, indicating that EGFR promoted SCC10A cell migration and invasion possibly by an epithelial to mesenchymal transition (EMT)-like phenotype change. Interestingly, activation of EGFR by EGF induced production of matrix metalloproteinase-9 (MMP-9) and soluble E-cadherin (sE-cad), and knockdown of MMP-9 by siRNA inhibited sE-cad production induced by EGF in SCC10A. Moreover, both MMP-9 knockdown and E-cadherin overexpression inhibited cell migration and invasion induced by EGF in SCC10A. The results indicate that EGFR activation promoted cell migration and invasion through inducing MMP-9-mediated degradation of E-cadherin into sE-cad. Pharmacologic inhibition of EGFR, MEK, and PI3K kinase activity in SCC10A reduced phosphorylated levels of ERK-1/2 and AKT, production of MMP-9 and sE-cad, cell migration and invasion, and expressional changes of EMT markers (E-cadherin and N-cadherin) induced by EGF, indicating that EGFR activation promotes cell migration and invasion via ERK-1/2 and PI3K-regulated MMP-9/E-cadherin signaling pathways. Taken together, the data suggest that EGFR activation promotes HNSCC SCC10A cell migration and invasion by inducing EMT-like phenotype change and MMP-9-mediated degradation of E-cadherin into sE-cad related to activation of ERK-1/2 and PI3K signaling pathways.     

Cortactin and Exo70 mediated invasion of hepatoma carcinoma cells by MMP-9 secretion

This study was aimed to evaluate the regulation mechanism of cortactin (CTTN) on matrix metalloproteinases 9 (MMP-9) and its relations with Exo70 in invasion of hepatoma carcinoma (HCC) cells. The expression levels of CTTN, Exo70 and MMP-9 were detected in normal hepatocytes and various HCC cells by real-time PCR. Then the migration and invasion ability of these cells was revealed by scratch and invasion assay. The effects of CTTN on MMP-9 and the ability of migration and invasion were evaluated by silence and overexpress CTTN. During this process, the expression of CTTN was detected by Western blot, the activity and concentration of MMP-9 in supernatant of culture medium was detected by zymography and ELISA assay. Besides, Exo70 was also inhibited to reveal its effects on MMP-9 and the migration and invasion ability of LM3. Increased expression of CTTN, MMP-9, Exo70, reduced scratch area and increased puncture cell numbers were found in HCC cells (p < 0.05). The expression of CTTN was significantly correlated with Exo70 and the migration and invasion ability of HCC (p < 0.05). In addition, the activity and concentration of MMP-9 were significantly affected by the expression level of CTTN, while the expression of MMP-9 was not influenced. Besides, Exo70-si also exhibited significantly inhibition effects on the activity and concentration of MMP-9 and puncture cell numbers (p < 0.05). A synergistic reaction may exhibited on CTTN and Exo70, which could mediate the secretion of MMPs thereby regulate tumor invasion.     

Antitumor effects of the flavone chalcone: inhibition of invasion and migration through the FAK/JNK signaling pathway in human gastric adenocarcinoma AGS cells

Chalcones (benzylideneacetophenone) are cancer-preventive food components found in a human diet rich in fruits and vegetables. In this study, we first report the chemopreventive effect of chalcone in human gastric adenocarcinoma cell lines: AGS. The results showed that chalcone could inhibit the abilities of the adhesion, invasion, and migration by cell–matrix adhesion assay, Boyden chamber invasion/migration assay, and wound-healing assay. Molecular data showed that the effect of chalcone in AGS cells might be mediated via sustained inactivation of the phosphorylation of focal adhesion kinase (FAK) and c-Jun N-terminal kinase 1 and 2 (JNK1/2) signal involved in the downregulation of the expressions of matrix metalloproteinase-2 (MMP-2) and matrix metalloproteinase-9 (MMP-9). Next, chalcone-treated AGS cells showed tremendous decrease in the phosphorylation and degradation of inhibitor of kappaBα (IκBα), the nuclear level of NF-κB, and the binding ability of NF-κB to NF-κB response element. Furthermore, treating FAK small interfering RNA (FAK siRNA) and specific inhibitor for JNK (SP600125) to AGS cells could reduce the phosphorylation of JNK1/2 and the activity of MMP-2 and MMP-9. Our results revealed that chalcone significantly inhibited the metastatic ability of AGS cells by reducing MMP-2 and MMP-9 expressions concomitantly with a marked reduction on cell invasion and migration through suppressing and JNK signaling pathways. We suggest that chalcone may offer the application in clinical medicine.     

LncRNA CRNDE promotes the epithelial-mesenchymal transition of hepatocellular carcinoma cells via enhancing the Wnt/β-catenin signaling pathway

Colorectal neoplasia differentially expressed (CRNDE) is a significantly upregulated long noncoding RNA in hepatocellular carcinoma (HCC). CRNDE could promote cell proliferation, migration, and invasion, while its molecular mechanisms were still largely unclear. In this study, we investigated the expression and function of CRNDE. CRNDE was significantly upregulated in tumor tissues compared with adjacent normal tissues. In vitro, we revealed that knockdown of CRNDE inhibited cell proliferation, migration, and cell invasion capacities in HCC. Animal studies indicated that CRNDE knockdown represses both growth and metastasis of HCC tumors in vivo. Moreover, knockdown of CRNDE suppressed the cell epithelial-mesenchymal transition (EMT) process by increasing the expression of E-cadherin and ZO-1, whereas, decreasing the expression of N-cadherin, slug, twist, and vimentin in HCC cells. We also revealed that knockdown of CRNDE suppressed the Wnt/β-catenin signaling in HCC. Thus, CRNDE could modulate EMT of HCC cells and knockdown of CRNDE impaired the mesenchymal properties. CRNDE increased invasion of HCC cells might be through activating the Wnt/β-catenin signaling pathway.     

Hypoxia Promotes Epithelial - Mesenchymal Transition of Hepatocellular Carcinoma Cells via Inducing GLIPR-2 Expression

Glioma pathogenesis related-2 (GLIPR-2) belongs to pathogenesis related-1 (PR-1) family whose function remains unknown. In our previous studies, GLIPR-2 was found to be a novel potent stimulator of epithelial-to-mesenchymal transition (EMT) in renal fibrosis which has been classified as type 2 EMT. However, whether GLIPR-2 could induce type 3 EMT in carcinogenesis needs further investigation. In this study, we showed that GLIPR-2 was expressed in hepatocellular carcinoma (HCC) tissues, hypoxia could upregulate the expression of GLIPR-2 in HepG2 and PLC/PRF/5 cells in vitro, overexpression of this protein promoted migration and invasion via EMT, knockdown of GLIPR-2 attenuated migration and invasion of HepG2 and PLC/PRF/5 cells in hypoxia. Moreover, extracellular signal-regulated kinases 1 and 2 (ERK1/2) are positively regulated by GLIPR-2. Taken together, we provide evidence for a hypoxia/GLIPR-2/EMT/migration and invasion axis in HCC cells and it provides novel insights into the mechanism of migration and invasion of hepatocellular carcinoma cells in hypoxia condition.     

SPHK1 (sphingosine kinase 1) induces epithelial-mesenchymal transition by promoting the autophagy-linked lysosomal degradation of CDH1/E-cadherin in hepatoma cells

SPHK1 (sphingosine kinase 1), a regulator of sphingolipid metabolites, plays a causal role in the development of hepatocellular carcinoma (HCC) through augmenting HCC invasion and metastasis. However, the mechanism by which SPHK1 signaling promotes invasion and metastasis in HCC remains to be clarified. Here, we reported that SPHK1 induced the epithelial-mesenchymal transition (EMT) by accelerating CDH1/E-cadherin lysosomal degradation and facilitating the invasion and metastasis of HepG2 cells. Initially, we found that SPHK1 promoted cell migration and invasion and induced the EMT process through decreasing the expression of CDH1, which is an epithelial marker. Furthermore, SPHK1 accelerated the lysosomal degradation of CDH1 to induce EMT, which depended on TRAF2 (TNF receptor associated factor 2)-mediated macroautophagy/autophagy activation. In addition, the inhibition of autophagy recovered CDH1 expression and reduced cell migration and invasion through delaying the degradation of CDH1 in SPHK1-overexpressing cells. Moreover, the overexpression of SPHK1 produced intracellular sphingosine-1-phosphate (S1P). In response to S1P stimulation, TRAF2 bound to BECN1/Beclin 1 and catalyzed the lysine 63-linked ubiquitination of BECN1 for triggering autophagy. The deletion of the RING domain of TRAF2 inhibited autophagy and the interaction of BECN1 and TRAF2. Our findings define a novel mechanism responsible for the regulation of the EMT via SPHK1-TRAF2-BECN1-CDH1 signal cascades in HCC cells. Our work indicates that the blockage of SPHK1 activity to attenuate autophagy may be a promising strategy for the prevention and treatment of HCC.     

Annexin A2 Promotes the Migration and Invasion of Human Hepatocellular Carcinoma Cells In Vitro by Regulating the Shedding of CD147-Harboring Microvesicles from Tumor Cells

It has been reported that Annexin A2 (ANXA2) is up-regulated in hepatocellular carcinoma (HCC), but the roles of ANXA2 in the migration and invasion of HCC cells have not been determined. In this study, we found that ANXA2-specific siRNA (si-ANXA2) significantly inhibited the migration and invasion of HCC cells co-cultured with fibroblasts in vitro. In addition, the production of MMP-2 by fibroblasts cultured in supernatant collected from si-ANXA2-transfected HCC cells was notably down-regulated. ANXA2 was also found to be co-localized and co-immunoprecipitated with CD147. Further investigation revealed that the expression of ANXA2 in HCC cells affected the shedding of CD147-harboring membrane microvesicles, acting as a vehicle for CD147 in tumor-stromal interactions and thereby regulating the production of MMP-2 by fibroblasts. Together, these results suggest that ANXA2 enhances the migration and invasion potential of HCC cells in vitro by regulating the trafficking of CD147-harboring membrane microvesicles.     

Osteopontin promotes hepatocellular carcinoma invasion by up-regulating MMP-2 and uPA expression

Osteopontin (OPN) is over-expressed in a variety of cancers, but its role in hepatocellular carcinoma (HCC) progression has not been clarified. In this study, weakly tumorigenic, non-metastastic human HCC cell line SMMC-7721 cells were forced to over-express OPN via stable transfection. A series of functional assays were performed to assess the effects of OPN on tumor cell behaviors and cDNA microarray was used to identify the genes regulated by OPN. The results showed that OPN significantly enhanced the migration and invasion of SMMC-7721 cells in vitro. In addition, CD44v6 antibody could significantly inhibit the invasion of OPN over-expressing SMMC-7721 cells. Moreover, MMP-2 and uPA expressions were significantly up-regulated in OPN over-expressing SMMC-7721 cells. Together, these findings indicate that OPN enhanced HCC cells invasion through interaction with its receptor CD44v6 and increased MMP-2 and uPA expressions, providing at least one mechanism for OPN-mediated HCC progression and metastasis.     

ROR2 promotes the epithelial-mesenchymal transition by regulating MAPK/p38 signaling pathway in breast cancer

Receptor tyrosine kinase-like orphan receptor 2 (ROR2) is a tyrosine-protein kinase receptor highly implicated in the growth plate and cartilage development, which may be involved in epithelial-mesenchymal transition (EMT) in breast cancer (BC) cells. Although ROR2 is known to promote the migration of BC cells, the detailed mechanism of this event is still not clear. Here, we found that ROR2 expression was significantly increased in BC lymphatic metastatic tissue as well as BC samples compared to normal adjacent breast tissues. A higher expression of ROR2 in MDA-MB-231 and a lower expression of ROR2 in MCF-7 cells were observed. MDA-MB-231-siROR2 cells with ROR2 knockdown inhibited MDA-MB-231 cell invasion, migration, and clonal formation, while MCF-7-OvROR2 cells with overexpression showed the opposite results. The underlying mechanisms involved in ROR2-induced EMT in MDA-MB-231 and MCF-7 cells were further investigated. ROR2 may activate EMT progression in BC cells by altering MAPK kinase 3/6 (MKK3/6) expression. The expressions of transforming growth factor-β, matrix metalloproteinase-2 (MMP-2), and MMP-9, which were related to tumor cell invasion activities, were notably increased in MCF-7-OvROR2 cells. The EMT markers, including snail, N-cadherin, tissue inhibitor of metalloproteinases-1, and vimentin, were significantly upregulated in MCF-7-OvROR2 cells. On the contrary, E-cadherin was obviously reduced expressed in MCF-7-OvROR2 cells. ROR2 may regulate the malignant phenotype of BC cells possibly via activation of mitogen-activated protein kinase (MAPK)/p38 signaling pathway. Collectively, ROR2 promotes BC carcinogenesis by mediating the MAPK/p38 pathway, which is independent of Wnt5α.     

Cancer/testis antigen LDHC promotes proliferation and metastasis by activating the PI3K/Akt/GSK-3β-signaling pathway and the in lung adenocarcinoma

The cancer/testis antigen lactate dehydrogenase-C4 (LDHC) is a specific isoenzyme of the LDH family that regulates invasion and metastasis in some malignancies; however, little is known regarding its role in progression of lung adenocarcinoma (LUAD). Thus, we investigated LDHC expression by immunohistochemistry, and analyzed its clinical significance in 88 LUAD specimens. The role and molecular mechanisms subserving LDHC in cellular proliferation, migration, and invasion were explored both in vitro and in vivo. As a result, we found that high LDHC expression was significantly correlated with clinicopathological features of aggressive LUAD and a poor prognosis. Overexpression of LDHC induced LUAD cells to produce lactate and ATP, increased their metastatic and invasive potential—, and accelerated xenograft tumor growth. We further demonstrated that overexpression of LDHC affected the expression of cell proliferation-related proteins (cyclin D1 and c-Myc) and epithelial-mesenchymal transition (EMT)-related proteins (MMP-2, MMP-9, E-cadherin, Vimentin, Twist, Slug, and Snail) both in vitro and in vivo. Finally, excessive activation of LDHC enhanced the phosphorylation levels of AKT and GSK-3β, revealing activation of the PI3K/Akt/GSK-3β oncogenic-signaling pathways. Treatment with a PI3K inhibitor reversed the effects of LDHC overexpression by inhibiting cellular proliferation, migration, and invasion, with diminished levels of p-Akt and p-GSK3β. PI3K inhibition also reversed cell proliferation-related and EMT-related proteins in LDHC-overexpressing A549 cells. In conclusion, LDHC promotes proliferation, migration, invasion, and EMT in LUAD cells via activation of the PI3K/Akt/GSK-3β pathway.     

Curcumin, demethoxycurcumin and bisdemethoxycurcumin differentially inhibit cancer cell invasion through the down-regulation of MMPs and uPA

Curcumin (Cur), a component of turmeric (Curcuma longa), has been reported to exhibit antimetastatic activities, but the mechanisms remain unclear. Other curcuminoids present in turmeric, demethoxycurcumin (DMC) and bisdemethoxycurcumin (BDMC) have not been investigated whether they exhibit antimetastatic activity to the same extent as curcumin. The regulation of matrix metalloproteinases (MMPs) and urokinase plasminogen activator (uPA) play important role in cancer cell invasion by cleavage of extracellular matrix (ECM). In this line, we comparatively examined the influence of Cur, DMC and BDMC on the expressions of uPA, MMP-2, MMP-9, membrane Type 1 MMP (MT1-MMP), tissue inhibitor of metalloproteinases (TIMP-2), and in vitro invasiveness of human fibrosarcoma cells. The results indicate that the differential potency for inhibition of cancer cell invasion was BDMC> or =DMC>Cur, whereas the cell migration was not affected. Zymography analysis exhibited that curcumin, DMC and BDMC significantly decreased uPA, active-MMP-2 and MMP-9 but not pro-MMP-2 secretion from the cells in a dose-dependent manner, in which BDMC and DMC show higher potency than curcumin. The suppression of active MMP-2 level correlated with inhibition of MT1-MMP and TIMP-2 protein levels involved in pro-MMP-2 activation. Importantly, BDMC and DMC at 10 microM reduced MT1-MMP and TIMP-2 protein expression, but curcumin slightly reduced only MT1-MMP but not TIMP-2. In addition, three forms of curcuminoids significantly inhibited collagenase, MMP-2, and MMP-9 but not uPA activity. In summary, these data demonstrated that DMC and BDMC show higher antimetastasis potency than curcumin by the differentially down-regulation of ECM degradation enzymes.     

Suppression of type 1 Insulin-like growth factor receptor expression by small interfering RNA inhibits A549 human lung cancer cell invasion in vitro and metastasis in xenograft nude mice

Cancer invasion and metastasis, involving a variety of pathological processes andcytophysiological changes,contribute to the high mortality of lung cancer.The type 1 insulin-like growthfactor receptor (IGF-1R),associated with cancer progression and invasion,is a potential anti-invasion andanti-metastasis target in lung cancer.To inhibit the invasive properties of lung cancer cells,we successfullydown-regulated IGF-1R gene expression in A549 human lung cancer cells by small interfering RNA (siRNA)technology,and evaluated its effects on invasion-related gene expression,tumor cell in vitro invasion,andmetastasis in xenograft nude mice.A549 cells transfected with a plasmid expressing hairpin siRNA forIGF-1R showed a significantly decreased IGF-1R expression at the mRNA level as well as the proteinlevel.In biological assays,transfected A549 cells showed a significant reduction of cell-matrix adhesion,migration and invasion.Consistent with these results,we found that down-regulation of IGR-1Rconcomitantly accompanied by a large reduction in invasion-related gene expressions,including MMP-2,MMP-9,u-PA,and IGF-1R specific downstream p-Akt.Direct tail vein injections of plasmid expressinghairpin siRNA for IGF- 1R significantly inhibited the formation of lung metastases in nude mice.Our resultsshowed the therapeutic potential of siRNA as a method for gene therapy in inhibiting lung cancer invasionand metastasis.     

Effects of laver extracts on adhesion,invasion, and migration in SK-Hep1 human hepatoma cancer cells

The laver (Porphyra tenera), red seaweed, has been reported to have anticancer activity, but little is known about its molecular mechanisms of action. The objective of this study was to determine the effects of laver extract on cancer cell proliferation, invasion, and metastasis in SK-Hep1 cells using migration and invasion assays. We also investigated the relationship of MMP-2/-9 and TIMP-1/-2 expression at both the protein and gene level in SK-Hep1 human hepatoma carcinoma cells after laver extract treatment. Laver extract inhibited cancer cell growth in a dose-dependent manner. In an invasion assay conducted in Transwell chambers, laver extract showed 19.6 and 27.2% inhibition of cancer cell at 200 and 400 μg/mL, respectively, compared to the control. The mRNA levels of both MMP-2 and MMP-9 were down-regulated by laver extract treatment in a dose-dependent manner. Laver extract, at 400 μg/mL, was inhibited by MMP-2 and MMP-9 expressions by 70.1 and 77.0%, respectively. An inverse relationship in the mRNA contents of MMP-2/-9 and TIMP-1/-2 expressions in SK-Hep1 cells was found by laver extract treatment. Our results demonstrate antimetastatic properties of laver extract in inhibiting the adhesion, invasion, and migration of SK-Hep1 human hepatoma cancer cells.