LRRC1通过DLG1/YAP信号通路促进肝癌细胞增殖的研究

目的 研究富含亮氨酸的重复序列蛋白1(LRRC1)通过巨盘状蛋白1(DLG1)/Yes相关蛋白(YAP)信号通路调节肝癌细胞增殖的机制。方法 在原发性肝细胞癌患者的癌灶组织及配对癌旁组织中,检测LRRC1的表达水平。使用小干扰RNA(siRNA)抑制HepG2及Huh7中LRRC1的表达后,检测细胞增殖能力及YAP、细胞周期蛋白D1(Cyclin D1)和细胞周期蛋白依赖性激酶4(CDK4)表达水平。通过共聚焦显微镜,定位HepG2细胞中LRRC1与DLG1分布。结果 肝细胞癌患者癌灶中LRRC1表达量较癌旁组织升高。siRNA 抑制HepG2及Huh7细胞中LRRC1基因表达后,细胞增殖能力受到抑制,YAP、Cyclin D1及CDK4表达水平下降。镜下发现HepG2细胞中LRRC1与DLG1均主要分布于细胞膜内侧面,两者分布位置高度重叠。结论 LRRC1通过DLG1/YAP信号通路调控细胞周期,促进肝癌细胞增殖。     

Increased iNOS activity is essential for intestinal epithelial tight junction dysfunction in endotoxemic mice

We tested the hypothesis that increased production of nitric oxide (NO.) associated with lipopolysaccharide (LPS)-induced systemic inflammation leads to functionally significant alterations in the expression and/or targeting of key tight junction (TJ) proteins in ileal and colonic epithelium. Wild-type or inducible NO. synthase (iNOS) knockout male C57B1/6J mice were injected intraperitoneally with 2 mg/kg Escherichia coli O111:B4 LPS. iNOS was inhibited using intraperitoneal L-N(6)-(1-iminoethyl)lysine (L-NIL; 5 mg/kg). Immunoblotting of total protein and NP-40 insoluble proteins revealed decreased expression and decreased TJ localization, respectively, of the TJ proteins, zonula occludens (ZO)-1, ZO-2, ZO-3, and/or occludin in ileal mucosa and colonic mucosa (total protein only) after injection of C57B1/6J mice with LPS. Immunohistochemistry showed deranged distribution of ZO-1 and occludin in both tissues from endotoxemic mice. Endotoxemia was associated with evidence of gut epithelial barrier dysfunction evidenced by increased ileal mucosal permeability to fluorescein isothiocyanate-dextran (Mr=4 kDa) and increased bacterial translocation to mesenteric lymph nodes. Pharmacologic inhibition of iNOS activity using L-NIL or genetic ablation of the iNOS gene ameliorated LPS-induced changes in TJ protein expression and gut mucosal barrier function. These results support the view that at least one mechanism contributing to the pathogenesis of gastrointestinal epithelial dysfunction secondary to systemic inflammation is increased iNOS-dependent NO. production leading to altered expression and localization of key TJ proteins.     

MTA1调控HIF-1α/VEGF通路作用于胰腺癌细胞增殖和迁移能力的研究

目的研究肿瘤转移相关蛋白1(MTA1)对胰腺癌细胞增殖、迁移和缺氧诱导因子(HIF-1α)/血管内皮生长因子(VEGF)信号通路的影响。方法采用Western blot检测MTA1在人胰腺癌组织、癌旁组织组织中的表达。采用酶联免疫吸附(ELISA)检测胰腺癌肿瘤细胞系PDAC-1培养上清液中MTA1浓度。然后加入不同浓度(5.0 ng/ml、10.0 ng/ml、15.0 ng/ml、20.0 ng/ml)的外源性MTA1处理胰腺癌肿瘤细胞系PDAC-1 48 h,MTT法检测细胞增殖。采用MTA1(20.0 ng/ml)和YC-1(50μmol/L)分别单独或联合作用于胰腺癌肿瘤细胞系PDAC-1 48 h,MTT法检测细胞增殖;采用划痕法检测细胞迁移能力;24 h时Western blot检测HIF-1α/VEGF信号通路中的关键蛋白HIF-1α和VEGF蛋白的水平。结果 MTA1在胰腺癌组织中的表达显著高于癌旁组织(P <0.05)。胰腺癌肿瘤细胞系PDAC-1自然生长条件下分泌的MTA1水平随着时间的增加在不断增大,48h后浓度为(0.041±0.003) ng/ml与后续研究中加入的外源MTA1浓度相比,可忽略不计。MTA1浓度在5.0~20.0 ng/ml时,从作用第12小时开始能够显著促进胰腺癌肿瘤细胞系PDAC-1的增殖(P <0.05)具有时间和剂量依赖效应。YC-1能够抑制胰腺癌肿瘤细胞系PDAC-1的增殖和迁移能力。MTA1能够促进HIF-1α和VEGF蛋白的表达,而YC-1能够降低MTA1对HIF-1α和VEGF蛋白表达的促进作用。结论 MTA1可以促进胰腺癌肿瘤细胞系PDAC-1的增殖和迁移,且具有时间和浓度依赖效应,其作用机制可能与HIF-1α/VEGF信号通路相关。     

Long noncoding RNA CCHE1 indicates a poor prognosis of hepatocellular carcinoma and promotes carcinogenesis via activation of the ERK/MAPK pathway

Survival of patients with hepatocellular carcinoma (HCC) remains poor, which is largely attributed to active carcinogenesis. Accumulating evidence implies that long noncoding RNAs (lncRNAs) could play a pivotal role in cancer biology. However, the clinical valueand biological significance of CCHE1 in HCC carcinogenesis remains to be discovered. Expression of CCHE1was analyzed in 112 HCC tissues and cell lines by qRT–PCR. The higher expression of CCHE1 was significantly correlated with tumor number, tumor size and TNM stage. Multivariate analyses revealed that CCHE1 expression served as an independent predictor for overall survival. Moreover, the effect of CCHE1 on proliferation was evaluated by MTT assays, and cell apoptosis was detected by flow-cytometric analysis. Further experiments demonstrated that CCHE1 knockdown significantly promoted growth arrest and cell apoptosis. Importantly, we further confirmed that ERK/MAPK pathway was found to be inactivated in the HCC cells after CCHE1 knockdown. To our knowledge, this is the first report showed that the role and the mechanism of CCHE1 in the progression of HCC. Together, these results suggest that lncRNA CCHE1 may serve as a candidate prognostic biomarker and target for new therapies in human HCC.     

Overexpression of JAKMIP1 associates with Wnt/beta-catenin pathway activation and promotes cancer cell proliferation in vitro

JAKMIP1 is a member of the recently characterized JAKMIP1 family of proteins. It has been suggested that JAKMIP1 may play a role in various cell programs, such as cytoskeleton rearrangement, cell polarization, intracellular transport or even cell signaling activities. We examined its protein expression in tumor and followed it with a model that captures its impact on activities of some tumor-linked signaling pathways as well as how its upregulation affects cell proliferation. Here, we demonstrate that JAKMIP1 is highly expressed in tumor samples than in normal tissues. Additionally, higher expression of this protein may activate Wnt signaling activity, potentiate beta-catenin accumulation and enhance proliferation of cancer cells.     

INHBA promotes the proliferation,migration and invasion of colon cancer cells through the upregulation of VCAN

ObjectiveColon cancer has high morbidity and mortality rates, and proliferation, invasion and migration play an important role in colon cancer progression. Here, the effects of inhibin subunit beta A (INHBA) on cell proliferation, invasion and migration were investigated.MethodsThe UALCAN database was used to assess INHBA expression in colon cancer tissues and predict the survival of patients with high and low INHBA expression. The relevant proteins were detected by RT-qPCR and western blot. Cell transfection was performed to overexpress or inhibit INHBA and versican (VCAN). The high correlation between INHBA and VCAN found through LinkedOmics and StarBase databases was verified by immunoprecipitation assays. Cell proliferation was detected by cell counting kit-8 and colony formation assays. Wound healing and Transwell assays were used to assess migration and invasion.ResultsINHBA expression was upregulated in colon cancer tissues and cells. INHBA inhibition impaired the proliferation, migration and invasion of these cells. In addition, we confirmed the correlation between INHBA and VCAN in colon cancer cells. Finally, we found that INHBA interference inhibited the aggressive behavior of colon cancer cells by downregulating VCAN.ConclusionINHBA promotes the proliferation, migration and invasion of colon cancer cells through the upregulation of VCAN.     

肝癌组织中lncRNA-PRR34-AS1的表达特性及其对肝癌细胞增殖、迁移的影响和潜在分子机制

目的　分析长链非编码RNA-PRR34-AS1在肝癌组织中的表达特性，探究其对肝癌细胞增殖、迁移的影响及潜在分子作用机制。方法　收集2020年6月～12月于榆林市第二医院行手术治疗的30例肝癌患者癌组织及其对应癌旁正常组织标本，采用实时荧光定量PCR实验（RT-qPCR）检测组织中LncRNA-PRR34-AS1相对表达水平。通过转染siRNA介导敲低PRR34-AS1基因表达，利用细胞增殖实验和细胞迁移实验验证PRR34-AS1对肝癌细胞增殖、迁移的影响；通过生物信息学数据库网站预测PRR34-AS1与JAK1结合的基因位点，双荧光素酶报告基因实验验证两者靶向关系，探究其在肝癌发生发展中的调控作用。结果　30例临床肝癌组织中PRR34-AS1表达显著高于癌旁正常组织（5.714±0.612 vs 2.981±0.572)，差异有统计学意义(t=17.870，P=0.000），PRR34-AS1具有高表达预后差的临床特征。敲低PRR34-AS1后，转染24，48和72 h时siRNA-PRR34-AS1#1组和siRNA-PRR34-AS1#2组细胞增殖率较对照组明显降低，差异均有统计学意义（F=83.440～89.297，均P<0.001）；siRNA-PRR34-AS1#1组（38.451±4.263）和siRNA-PRR34-AS1#2组（42.106±3.512）细胞愈合迁移速率较对照组（83.247±6.205）显著减慢，差异均有统计学意义（F=83.357，P＜0.001）。JAK1是PRR34-AS1的靶基因，siRNA-PRR34-AS1#1组（0.453±0.019）和siRNA-PRR34-AS1#2组（0.476±0.022）细胞中JAK1相对表达较对照组相比（1.002±0.003）明显降低，差异均有统计学意义（F=716.287，P＜0.001）。转染敲低JAK1表达后，各转染时间点siRNA-JAK1#1组和siRNA-JAK1#2组细胞增殖速率较对照组明显减缓，差异均有统计学意义（F=45.465~76.548，均P<0.05）。30组临床肝癌组织中JAK1表达显著高于癌旁正常组织（5.963±1.214 vs 4.052±0.876)，差异有统计学意义(t=6.992，P=0.000），PRR34-AS1与JAK1表达呈显著正相关（r=0.907，P<0.05）。在敲低PRR34-AS1表达的肝癌细胞中回补JAK1后，肝癌细胞增殖、迁移速率又回归到正常水平。结论　肝癌中PRR34-AS1显著高表达，其可能通过正向调控JAK1表达影响JAK/STAT信号通路，进而调控促进肝癌细胞的增殖和迁移。     

Caprin-1 is a novel microRNA-223 target for regulating the proliferation and invasion of human breast cancer cells

MicroRNAs (miRNAs) are 21–22 nucleotides regulatory small non-coding RNAs that inhibit gene expression by binding to complementary sequences especially the 3’ untranslated region (3’UTR) of mRNA. One miRNA can target many messenger RNAs, leading to a complex metabolic network. Previous studies have shown that miRNA-223 regulates migration and invasion of tumor cells and targets cytoplasmic activation/proliferation-associated protein-1 (Caprin-1). In the present study, we detected the expression of miRNA-223 and Caprin-1 in MCF-7, T-47D and MDA-MB-231 cancer cell lines, and MCF-10A normal breast cell line, and analyzed the role of miRNA-223 in Caprin-1-induced proliferation and invasion of human breast cancer cells. We found that miRNA-223 expression levels are significantly lower in MCF-7, T-47D and MDA-MB-231 cancer cells than in MCF-10A normal breast cells, while Caprin-1 expression is higher in cancer cells than in normal breast cells. The most malignant cancer cell line MDA-MB-231 has the lowest expression of miR-223, but the highest expression of Caprin-1. Further, we found that miR-223 targets the 3’UTR of Caprin-1 miRNA and down-regulates the expression of Caprin-1. We also found that over-expression of Caprin-1 can promote the proliferation and the invasion of breast cancer cells, but miRNA-223 can inhibit the proliferation and the invasion. miRNA-223-induced inhibition can be reversed by ectopic over-expression of Caprin-1. These findings suggest that miR-223 may suppress the proliferation and invasion of cancer cells by directly targeting Caprin-1. Our study also indicates that expression levels of miR-223 and Caprin-1 can be used to predict the state of cancer in breast cancer patient.     

miR-203a-3p 靶向GLS1 调控HCC 细胞增殖、迁移、侵袭的机制研究

目的　探究微小核糖核酸（microRNAs, miRNA, miR）-203a-3p 对肝细胞癌（hepatocellular carcinoma,HCC）细胞增殖、迁移、侵袭的影响及其潜在分子机制。方法　采用实时荧光定量PCR（quantitative real-time PCR,qRTPCR）检测HCC 细胞、人正常肝细胞以及临床HCC 组织中miR-203a-3p 相对表达;采用细胞增殖实验、细胞划痕实验和Transwell 实验分别检测miR-203a-3p 对HCC 细胞增殖、迁移、侵袭的影响;生物信息学网站预测miR-203a-3p 的潜在靶基因（GLS1）,双荧光素酶实验进行验证;探究HCC 细胞对谷氨酰胺的依赖性及抑制谷氨酰胺酶1(glutaminase 1,GLS1) 对HCC 细胞增殖、迁移、侵袭的影响;蛋白免疫印迹（Western blot）实验检测Wnt/β-catenin 信号通路关键蛋白β-catenin,p-GSK-3β 和c-Myc 表达。结果　HCC 癌组织中miR-203a-3p（0.32±0.07）表达明显低于癌旁正常组织（1.02±0.03）,差异有统计学意义（t ＝ 41.105,P ＜ 0.001）;HCC 细胞HepG2（0.34±0.05）,HCCLM3（0.58±0.06）,Huh7（0.43±0.05）,Hep3B（0.29±0.04）中miR-203a-3p 相对表达水平明显低于人正常肝细胞LO2（1.01±0.02）中miR-203a-3p 表达,差异有统计学意义（F ＝ 119.080,P ＜ 0.001）。与Blank 组相比,miR-203a-3p 过表达组HCC细胞增殖（0.61±0.05 vs 1.24±0.06）, 迁移率（21.43%±2.01% vs 60.22%±3.14%） 及侵袭能力（76.54±13.56 vs221.06±16.54）均明显降低,差异有统计学意义（t ＝ 14.849,13.900,10.562,均P ＜ 0.001）。GLS1 是miR-203a-3p的靶基因,miR-203a-3p 靶向负调控GLS1 表达。HCC 细胞中GLS1 高表达呈现高酶活性,HCC 细胞对谷氨酰胺存在明显依赖性。GLS1 抑制组α-KG,谷氨酸水平均较Blank 组和siRNA-NC 组明显降低,差异有统计学意义（F ＝ 64.754,35.627,均P ＜ 0.001）。GLS1 抑制组细胞增殖（0.59±0.04）、迁移率（30.15%±1.02%）和侵袭能力（69.59±15.74）较Blank 组明显降低（1.29±0.07,59.67%±1.45%,202.14±13.52）,差异均有统计学意义（t ＝ 16.499,16.278,11.215,均P ＜ 0.001）。miR-203a-3p 过表达和GLS1 表达抑制明显抑制了Wnt/β-catenin 信号通路关键蛋白β-catenin,p-GSK-3β 和c-Myc 的表达,差异均有统计学意义（t ＝ 11.129 ～ 28.213,均P ＜ 0.001）。转染GLS1 可逆转miR-203a-3p 对HCC 细胞生物学行为及Wnt/β-catenin 信号通路关键蛋白表达的抑制作用。结论　HCC 中miR-203a-3p 显著低表达,其过表达能够抑制HCC 细胞的增殖、迁移和侵袭,可能与GLS1 调控谷氨酰胺代谢及miR-203a-3p 靶向GLS1调控Wnt/β-catenin 信号通路活性有关。     

MicroRNA-744 inhibited cervical cancer growth and progression through apoptosis induction by regulating Bcl-2

Growing evidence suggests that microRNA plays an essential role in the development and metastasis of many tumor progressions, including cervical cancer. Aberrant miR-744 expression has been indicated in many growth of tumor, the mechanism of miR-744 inhibits both the proliferation and metastatic ability for cervical cancer remains unclear. Accumulating evidences reported that Bcl-2 signal pathway plays an important role in the cellular process, such as apoptosis, cell growth and proliferation. The goal of this study was to identify miR-744 that could inhibit the growth, migration, invasion, proliferation and metastasis of gastric cancer through targeting Bcl-2 expression. Real-time PCR (RT-qPCR) was used to quantify miR-744 expression in vitro and vivo experiments. The biological functions of miR-744 were determined via cell proliferation. Our study indicated that miR-744 targeted on Bcl-2, which leads to the inactivation of apoptosis signaling and the cell proliferation of cervical cancer cells, ameliorating cervical cancer growth and progression. In addition, both up-regulation of miR-744 and down-regulation of Bcl-2 could stimulate Caspase-3 expression, promoting apoptosis of cervical cancer cells. Therefore, our research revealed the mechanistic links between miR-744 and Bcl-2 in the pathogenesis of cervical cancer through modulation of Caspase-3, leading to the inhibition of cervical cancer cell growth. And targeting miR-744 could be served as a novel strategy for future cervical cancer therapy clinically.     

DLK1 as a potential target against cancer stem/progenitor cells of hepatocellular carcinoma

Delta-like 1 homolog (DLK1; Drosophila) is a hepatic stem/progenitor cell marker in fetal livers that plays a vital role in oncogenesis of hepatocellular carcinoma (HCC). The aim of this study is to investigate whether DLK1 could serve as a potential therapeutic target against cancer stem/progenitor cells of HCC. DLK1(+) and DLK1(-) cells were sorted by fluorescence-activated cell sorting and magnetic-activated cell sorting, respectively, and then were evaluated by flow cytometry. The biological behaviors of these isolated cells and those with DLK1 knockdown were assessed by growth curve, colony formation assay, spheroid colony formation, chemoresistance, and in vivo tumorigenicity. Adenovirus-mediated RNA interference was used to knockdown the endogenous DLK1. We found that DLK1(+) population was less than 10% in almost all 17 HCC cell lines examined. DLK1(+) HCC cells showed stronger ability of chemoresistance, colony formation, spheroid colony formation, and in vivo tumorigenicity compared with DLK1(-) cells. The DLK1(+) HCC cells could generate the progeny without DLK1 expression. Furthermore, DLK1 knockdown could suppress the ability of proliferation, colony formation, spheroid colony formation, and in vivo tumorigenicity of Hep3B and Huh-7 HCC cells. Our data suggested that DLK1(+) HCC cells have characteristics similar to those of cancer stem/progenitor cells. RNA interference against DLK1 can suppress the malignant behaviors of HCC cells, possibly through directly disrupting cancer stem/progenitor cells, which suggested that DLK1 could be a potential therapeutic target against the HCC stem/progenitor cells.     

The tumor-suppressor gene LZTS1 suppresses hepatocellular carcinoma proliferation by impairing PI3K/Akt pathway

BackgroundTo study the role of LZTS1 in hepatocellular carcinoma (HCC) proliferation and the molecular mechanism involved.MethodsLZTS1 expression was studied in 10 HCC cell lines and 1 normal hepatocyte cell line by western blot analysis and qRT-PCR. One HCC cell line was selected and transfected with LZTS1 lentivirus. Cell proliferation and cell cycle were then determined by CCK-8 assay and flow cytometry, respectively. LZTS1, cyclin D1, CDK1, Cdc25C, pS473 Akt, and pT308 Akt mRNA and protein expressions were measured. PS473 Akt and pT308 Akt expression level was also compared with the HCC cells treated with LY294002.ResultsCompared with the normal hepatocyte cells, LZTS1 expression in HCC cells was significantly lower. After the transfection with LZTS1 lentivirus, HCC cell proliferation ability decreased markedly and HCC cells were blocked at G2/M phase. Cyclin D1 and CDK1 expression were both decreased but not significantly. Cdc25C expression was increased significantly. PS473 Akt and pT308 Akt expression level was increased significantly as well, which were almost the same with those transfected with LY294002.ConclusionLZTS1 could inhibit HCC cell proliferation by impairing PI3K/Akt pathway.     

miR-663a inhibits hepatocellular carcinoma cell proliferation and invasion by targeting HMGA2

Hepatocellular carcinoma (HCC) is a highly aggressive solid malignancy throughout the world. Dysregulation of miRNAs play essential roles in HCC progression via aberrant regulation of cell proliferation, apoptosis, as well as metastasis. miR-663a is a poorly investigated miRNA. Whether miR-663a regulates HCC development remains unknown. The aim of the study was to explore the role of miR-663a in HCC development. To determine the expression level of miR-663a in HCC, we analyzed the data from GSE21362 and TCGA. The results showed that miR-663a was significantly down-regulated in HCC tissue compared with adjacent non-tumor tissue. Gain of function and loss of function assays revealed that miR-663a distinctly inhibited cell proliferation, migration and invasion. Mechanistic investigations demonstrated that miR-663a modulated cell functions through targeting and suppressing high mobility group A2 (HMGA2). In addition, overexpression of HMGA2 remarkably attenuated the tumor repressive effect of miR-663a. Taken together, miR-663a inhibits HCC cell proliferation and motility by targeting HMGA2.     

Paeoniflorin inhibits proliferation and invasion of breast cancer cells through suppressing Notch-1 signaling pathway

Paeoniflorin (PF), one of the major active ingredients of Chinese peony, was reported to possess anti-tumor effect. However, the role of PF in breast cancer remains to be clarified. Therefore, in this context, the present study investigated the effects of PF on breast cancer cell proliferation and invasion, as well as the underlying mechanism. Our results found that PF suppressed the proliferation and invasion of breast cancer cells. We further demonstrated that PF down-regulated the expression of Notch-1; in addition, overexpression of Notch-1 reversed PF-inhibited proliferation and invasion, and knockdown of Notch-1 enhanced PF-inhibited proliferation and invasion in breast cancer cells. In conclusion, the present study suggests that PF inhibits proliferation and invasion of breast cancer cells through suppressing Notch-1 signaling pathway. Therefore, PF may represent a chemopreventive and/or therapeutic agent in the prevention of breast cancer.     

Mechanisms of resveratrol in the prevention and treatment of gastrointestinal cancer

Gastrointestinal (GI) cancer is one of the leading causes of cancer-related deaths worldwide. According to the Global Cancer Statistics, colorectal cancer is the second leading cause of cancer-related mortality, closely followed by gastric cancer (GC). Environmental, dietary, and lifestyle factors including cigarette smoking, alcohol intake, and genetics are the most important risk factors for GI cancer. Furthermore, infections caused by Helicobacter pylori are a major cause of GC initiation. Despite improvements in conventional therapies, including surgery, chemotherapy, and radiotherapy, the length or quality of life of patients with advanced GI cancer is still poor because of delayed diagnosis, recurrence and side effect. Resveratrol (3, 4, 5-trihydroxy-trans-stilbene; Res), a natural polyphenolic compound, reportedly has various pharmacologic functions including anti-oxidant, anti-inflammatory, anti-cancer, and cardioprotective functions. Many studies have demonstrated that Res also exerts a chemopreventive effect on GI cancer. Research investigating the anti-cancer mechanism of Res for the prevention and treatment of GI cancer has implicated multiple pathways including oxidative stress, cell proliferation, and apoptosis. Therefore, this paper provides a review of the function and molecular mechanisms of Res in the prevention and treatment of GI cancer.     

Claudin-1 regulates cellular transformation and metastatic behavior in colon cancer

Disruption of the cell-cell junction with concomitant changes in the expression of junctional proteins is a hallmark of cancer cell invasion and metastasis. The role of adherent junction proteins has been studied extensively in cancer, but the roles of tight junction (TJ) proteins are less well understood. Claudins are recently identified members of the tetraspanin family of proteins, which are integral to the structure and function of TJs. Recent studies show changes in expression/cellular localization of claudins during tumorigenesis; however, a causal relationship between claudin expression/localization and cancer has not been established. Here, we report an increased expression of claudin-1 in human primary colon carcinoma and metastasis and in cell lines derived from primary and metastatic tumors. We also report frequent nuclear localization of claudin-1 in these samples. Genetic manipulations of claudin-1 expression in colon cancer cell lines induced changes in cellular phenotype, with structural and functional changes in markers of epithelial-mesenchymal transition. Furthermore, we demonstrate that changes in claudin-1 expression have significant effects on growth of xenografted tumors and metastasis in athymic mice. We further provide data suggesting that the regulation of E-cadherin expression and β-catenin/Tcf signaling is a possible mechanism underlying claudin-1–dependent changes.