TJP1

Gene Summary

Gene:TJP1; tight junction protein 1
Aliases: ZO-1
Location:15q13.1
Summary:This gene encodes a protein located on a cytoplasmic membrane surface of intercellular tight junctions. The encoded protein may be involved in signal transduction at cell-cell junctions. Alternative splicing of this gene results in multiple transcript variants. [provided by RefSeq, Jul 2014]
Databases:VEGA, OMIM, HGNC, Ensembl, GeneCard, Gene
Protein:tight junction protein ZO-1
Source:NCBIAccessed: 11 March, 2017

Ontology:

What does this gene/protein do?
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Pathways:What pathways are this gene/protein implicaed in?
Show (4)

Cancer Overview

Research Indicators

Publications Per Year (1992-2017)
Graph generated 11 March 2017 using data from PubMed using criteria.

Literature Analysis

Mouse over the terms for more detail; many indicate links which you can click for dedicated pages about the topic.

  • bcl-X Protein
  • Colorectal Cancer
  • Transcription Factors
  • Epithelial-Mesenchymal Transition
  • Claudins
  • DNA Methylation
  • Promoter Regions
  • Adenocarcinoma
  • Cell Proliferation
  • Zonula Occludens-2 Protein
  • Cell Communication
  • snail family transcription factors
  • Leukaemia
  • Up-Regulation
  • Mice, Inbred BALB C
  • Adolescents
  • Claudin-1
  • Immunohistochemistry
  • Neoplasm Invasiveness
  • siRNA
  • Lung Cancer
  • Transfection
  • Claudin-5
  • Epithelial Cells
  • Neoplasm Metastasis
  • Signal Transduction
  • Young Adult
  • MicroRNAs
  • Membrane Proteins
  • Tight Junctions
  • Breast Cancer
  • Phosphoproteins
  • Cancer Gene Expression Regulation
  • Cell Movement
  • Chromosome 15
  • Cadherins
  • Western Blotting
  • Occludin
  • Messenger RNA
  • RTPCR
Tag cloud generated 11 March, 2017 using data from PubMed, MeSH and CancerIndex

Specific Cancers (4)

Data table showing topics related to specific cancers and associated disorders. Scope includes mutations and abnormal protein expression.

Note: list is not exhaustive. Number of papers are based on searches of PubMed (click on topic title for arbitrary criteria used).

Latest Publications: TJP1 (cancer-related)

Zuo ZK, Gong Y, Chen XH, et al.
TGFβ1-Induced LncRNA UCA1 Upregulation Promotes Gastric Cancer Invasion and Migration.
DNA Cell Biol. 2017; 36(2):159-167 [PubMed] Related Publications
According to recent studies, long noncoding RNA urothelial carcinoma associated 1 (UCA1) is involved in the development and progression of many malignant tumors, including gastric cancer (GC). We validated the detailed role of UCA1 in human GC cell lines and GC tissues so as to determine its exact function and the underlying mechanism of GC invasion and migration. In our research, lncRNA-UCA1 was specifically upregulated in GC tissues and cell lines, and augmented GC cell proliferation, and invasive and migratory capabilities. High UCA1 expression in GC was related with poorer prognosis (poorer invasion depth, lymph node metastasis, advanced TNM [T is for the original (primary) tumor, N for nearby (regional) lymph nodes that are involved, and M for distant metastasis] stage, and shorter overall survival). Epithelial mesenchymal transition (EMT), associated with malignancy of cancers, was reported to be responsible for invasion and migration of cancer cells. Transforming growth factor β1 (TGFβ1)-induced EMT was well evaluated. UCA1 silence reduced the protein levels of EMT-related factors, vimentin and snail, while promoted E-cadherin and zonula occludens-1 protein levels in GC cells; the effect of UCA1 could be partly restored by TGFβ1 treatment. Taken together, UCA1 might regulate the tumor proliferation, invasion, and metastasis under TGFβ1 induction. Taken together, UCA1 might present a potential oncogenic factor by promoting GC cell proliferation, invasion, and migration. UCA1 could serve as a novel biomarker for prognosis and a novel therapeutic target of GC treatment.

Nagai T, Arao T, Nishio K, et al.
Impact of Tight Junction Protein ZO-1 and TWIST Expression on Postoperative Survival of Patients with Hepatocellular Carcinoma.
Dig Dis. 2016; 34(6):702-707 [PubMed] Related Publications
BACKGROUND: Epithelial-mesenchymal transition (EMT) is considered to play a critical role in cancer progression and metastasis. However, the impact of EMT on the prognosis of hepatocellular carcinoma (HCC) is still elusive. In this study, we examined the relationship between the expression of EMT markers and recurrence-free survival (RFS) and overall survival (OS) in HCC patients after hepatic resection.
SUMMARY: The mRNA expression of 15 genes related to EMT was assessed by quantitative real-time polymerase chain reaction in cancerous tissues from 72 patients who underwent hepatic resection of HCC between January 2005 and December 2010 at our hospital. The upregulation of TWIST and the downregulation of tight junction protein ZO-1 (TJP1) were significantly associated with shorter RFS as well as OS. Increased levels of TWIST and decreased levels of TJP1 should be predictive markers for poor prognosis in patients with HCC after hepatectomy; those could serve as potential biomarkers for the treatment of HCC. Key Messages: A low level of TJP1 and high level of TWIST expression were prognostic factors predicting HCC after hepatic resection.

Zhang G, Chen L, Sun K, et al.
Neuropilin-1 (NRP-1)/GIPC1 pathway mediates glioma progression.
Tumour Biol. 2016; 37(10):13777-13788 [PubMed] Related Publications
Glioma occurs due to multi-gene abnormalities. Neuropilin-1 (NRP-1), as a transmembrane protein, involves in glioma proliferation, invasion, and migration, as well as tumor angiogenesis. The cytoplasmic protein, GAIP/RGS19-interacting protein (GIPC1), could regulate the clathrin-vesicles trafficking and recycling. Here, we show that NRP-1 co-localizes and co-immunoprecipitates with GIPC1, and the C-terminal SEA-COOH motif of NRP-1 interacts specially with the named from three proteins: PSD-95 (a 95 kDa protein involved in signaling at the post-synaptic density), DLG (the Drosophila melanogaster Discs Large protein) and ZO-1 (the zonula occludens 1 protein involved in maintenance of epithelial polarity) (PDZ) domain of GIPC1 in glioma cells. Knockdown of GIPC1 by small interfering RNA (siRNA) significantly reduces the proliferation and invasion of glioma cells in vitro and increases its apoptosis. Furthermore, si-GIPC1 prevents the action of adaptor proteins adaptor protein, phosphotyrosine interaction, PH domain and leucine zipper containing 1 (APPL1) and p130Cas and inhibits the downstream kirsten rat sarcoma viral oncogene homolog (KRAS)-ERK signaling pathway. This study demonstrated that NRP-1/GIPC1 pathway plays a vital role in glioma progression, and it is a potential important target for multi-gene combined therapeutics.

Huang C, Wen B
Phenotype transformation of immortalized NCM460 colon epithelial cell line by TGF-β1 is associated with chromosome instability.
Mol Biol Rep. 2016; 43(10):1069-78 [PubMed] Related Publications
Transforming growth factor-β1 (TGF-β1) within tumor microenvironment has a pivotal function in cancer initiation and tumorigenesis, and hence this study was to observe the malignant transformation induced by TGF-β1 in an immortalized colon epithelial cell line NCM460 for better understanding the mechanisms of colon carcinogenesis. Immortalized colon epithelial cell line NCM460 was used as the model of this study, and was treated with different concentrations of TGF-β1 for different time. Then, immunofluorescence was performed to observe the change of phenotype hallmarks including adherent junction protein E-cadherin, cytoskeleton protein vimentin, and tight junction marker ZO-1, western blotting analysis was performed to detect the expression of the above three markers and two transcription factors (Snail and Slug) involved in the transformation by TGF-β1. In addition, chromosome instability (CHI) including analysis of DNA-ploid was detected by flow cytometry. Our results revealed significant loss or reduction of ZO-1 and E-cadherin, and robust emergence of vimentin in the cell line NCM460 after a 15-, 20-, and 25-day treatment with 10 ng/ml TGF-β1. Interestingly, 20 and 25 days after stimulation with 5 ng/ml TGF-β1, expression of E-cadherin and ZO-1 revealed a pattern roughly similar to that of 10 ng/ml TGF-β1, especially, both expressions was vanished and vimentin expression was dramatically increased at days 25 after TGF-β1 stimulation. After a stimulation with 10 ng/ml TGF-β1 for 15, 20, and 25 days, the levels of Snail and Slug expression in the cells were significantly up-regulated, compared with the cells treated with TGF-β1 inhibitor LY364947, PBS or balnk control (P < 0.01). Our results found that many abnormal mitotic patterns including lagging chromosomes and anaphase bridges in NCM460 cells were induced by TGF-β1 after its stimulation for 15, 20, and 25 days. Very few mitotic cells with treatment of PBS for 15, 20 and 25 days were non-diploid whose DNA content was greater or less than 4 N, but these cells were significantly increased after exposure to TGF-β1 for 15, 20, and 25 days, which was associated with the induction of hypo-diploid, hyper-diploid, and poly-diploid (P < 0.05).These data indicate that TGF-β1 induces a phenotypic transformation of normal colon epithelium similar to its pro-tumoral behaviors in TME, involving in alteration of chromosome stability.

Wang X, Guo H, Liu W, et al.
Effects of siRNA-Mediated Knockdown of HDAC1 on the Biological Behavior of Esophageal Carcinoma Cell Lines.
Med Sci Monit. 2016; 22:1291-6 [PubMed] Free Access to Full Article Related Publications
BACKGROUND HDAC1 has been shown to be closely associated with the occurrence of tumors. We aimed to investigate the effects of siRNA-mediated HDAC1 knockdown on the biological behavior of esophageal carcinoma cell lines. MATERIAL AND METHODS HDAC1 expression in esophageal cancer cell lines TE-1, Eca109, and EC9706 was compared by Western blot analysis. These cells were transfected with siRNA-HDAC1 and cell proliferation was evaluated by MTT assay to select the optimum cell line for subsequent experiments. The effects of siRNA-HDAC1 on the migration and invasion of the selected cell line were assessed by transwell assay. The expression of cell cycle-related proteins cyclinD1, p21 and p27, and epithelial-mesenchymal transition (EMT)-related protein zonula occludens-1 (ZO-1), E-cadherin and vimentin was determined by Western blot analysis. RESULTS HDAC1 expression in TE-1, Eca109 and EC9706 cells was significantly higher compared with normal esophageal cell line HEEC (P<0.01). MTT assay, Western blot and RT-PCR analyses demonstrated that the inhibitory effects of siRNA on HDAC1 expression and cell viability in TE-1 cells were the highest among all cell lines, which was therefore used in subsequent experiments. After TE-1 cells were transfected with siRNA-HDAC1, their migration and invasion were significantly lower compared with the controls (P<0.01). CyclinD1 and vimentin expression was significantly lower compared with the controls (P<0.01), whereas the expression of p21, p27, ZO-1 and E-cadherin was significantly higher (P<0.01). CONCLUSIONS The siRNA-mediated HDAC1 knockdown significantly inhibited the proliferation, migration and invasion of TE-1 cells probably by regulating the expression of cell cycle- and EMT-related proteins.

Yuan Z, Yu X, Ni B, et al.
Overexpression of long non-coding RNA-CTD903 inhibits colorectal cancer invasion and migration by repressing Wnt/β-catenin signaling and predicts favorable prognosis.
Int J Oncol. 2016; 48(6):2675-85 [PubMed] Related Publications
Accumulating evidence reveals that long non-coding RNA (lncRNA) is essential for tumorigenesis and progression, but little is known about its roles and mechanisms in metastatic colorectal cancer (CRC). This study aimed to detect expression level and prognostic role of lncRNA‑CTD903 in CRC patients, which was selected based on one microarray data. The effects on cell invasion, migration and proliferation were investigated after silencing or overexpression of CTD903 in CRC cell lines. We also observed the EMT (epithelial-mesenchymal transition) phenomenon and effect on cell adhesion. The associations between CTD903 and EMT markers, such as E-cadherin, N-cadherin, β-catenin, ZEB1, ZO-1, Snail, and Twist, were determined by western blotting. Our results showed lncRNA-CTD903 expression was strongly upregulated in 115 CRC patients, comparing to adjacent normal tissues. CTD903 was proven to be an independent predicted factor of favorable prognosis in CRC patients by using multivariate Cox proportional hazards model. After knockdown of CTD903 in RKO and SW480, both cell invasion and migration increased, and cells exhibited EMT-like appearance, along with reduced adhering ability. Moreover, overexpression of CTD903 in DLD1 and HCT116 reversed these phenotypes. Furthermore, downregulation of CTD903 enhanced Wnt/β-catenin activation and subsequently increased transcription factors (Twist and Snail) expression, along with increased mesenchymal marker Vimentin and decreased epithelial marker ZO-1 level, while overexpressed CTD903 confirmed these associations. In conclusion, this study shows that LncRNA-CTD903 acts as a tumor suppressor in CRC and can inhibit cell invasion and migration through repressing Wnt/β-catenin signaling, which plays important roles in EMT and CRC metastasis.

Ramena G, Yin Y, Yu Y, et al.
CLCA2 Interactor EVA1 Is Required for Mammary Epithelial Cell Differentiation.
PLoS One. 2016; 11(3):e0147489 [PubMed] Free Access to Full Article Related Publications
CLCA2 is a p53-, p63-inducible transmembrane protein that is frequently downregulated in breast cancer. It is induced during differentiation of human mammary epithelial cells, and its knockdown causes epithelial-to-mesenchymal transition (EMT). To determine how CLCA2 promotes epithelial differentiation, we searched for interactors using membrane dihybrid screening. We discovered a strong interaction with the cell junctional protein EVA1 (Epithelial V-like Antigen 1) and confirmed it by co-immunoprecipitation. Like CLCA2, EVA1 is a type I transmembrane protein that is regulated by p53 and p63. It is thought to mediate homophilic cell-cell adhesion in diverse epithelial tissues. We found that EVA1 is frequently downregulated in breast tumors and breast cancer cell lines, especially those of mesenchymal phenotype. Moreover, knockdown of EVA1 in immortalized human mammary epithelial cells (HMEC) caused EMT, implying that EVA1 is essential for epithelial differentiation. Both EVA1 and CLCA2 co-localized with E-cadherin at cell-cell junctions. The interacting domains were delimited by deletion analysis, revealing the site of interaction to be the transmembrane segment (TMS). The primary sequence of the CLCA2 TMS was found to be conserved in CLCA2 orthologs throughout mammals, suggesting that its interaction with EVA1 co-evolved with the mammary gland. A screen for other junctional interactors revealed that CLCA2 was involved in two different complexes, one with EVA1 and ZO-1, the other with beta catenin. Overexpression of CLCA2 caused downregulation of beta catenin and beta catenin-activated genes. Thus, CLCA2 links a junctional adhesion molecule to cytosolic signaling proteins that modulate proliferation and differentiation. These results may explain how attenuation of CLCA2 causes EMT and why CLCA2 and EVA1 are frequently downregulated in metastatic breast cancer cell lines.

Shimobaba S, Taga S, Akizuki R, et al.
Claudin-18 inhibits cell proliferation and motility mediated by inhibition of phosphorylation of PDK1 and Akt in human lung adenocarcinoma A549 cells.
Biochim Biophys Acta. 2016; 1863(6 Pt A):1170-8 [PubMed] Related Publications
Abnormal expression of claudin subtypes has been reported in various cancers. However, the pathological role of each claudin has not been clarified in detail. Claudin-18 was absent in human non-small cell and small cell lung cancers, although it is expressed in normal lung tissues. Here, we examined the effect of claudin-18 expression on the expression of junctional proteins, cell proliferation, and cell motility using human lung adenocarcinoma A549 cells. Real-time PCR and western blotting showed that exogenous expression of claudin-18 had no effect on the expression of junctional proteins including claudin-1, zonula occludens-1 (ZO-1), occludin, and E-cadherin. Claudin-18 was mainly distributed in cell-cell contact areas concomitant with ZO-1. Cell proliferation was significantly decreased at 48 and 72h after seeding of claudin 18-expressing cells. Claudin-18 suppressed cell motility, whereas it increased cell death in anoikis. Claudin-18 decreased phosphorylated (p)-3-phosphoinositide-dependent protein kinase-1 (PDK1) and p-Akt levels without affecting p-epidermal growth factor receptor and p-phosphatidylinositol-3 kinase (PI3K) levels. Furthermore, claudin-18 was bound with PDK1 and suppressed the nuclear localization of PDK1. We suggest that claudin-18 suppresses the abnormal proliferation and motility of lung epithelial cells mediated by inhibition of the PI3K/PDK1/Akt signaling pathway.

Sun R, Qin C, Jiang B, et al.
Down-regulation of MALAT1 inhibits cervical cancer cell invasion and metastasis by inhibition of epithelial-mesenchymal transition.
Mol Biosyst. 2016; 12(3):952-62 [PubMed] Related Publications
The metastasis-associated lung adenocarcinoma transcript 1(MALAT1), a member of the long non-coding RNA (lncRNA) family, has been reported to be highly enriched in many kinds of cancers and to be a metastasis marker and a prognostic factor. In this study, we found that MALAT1 expression levels were significantly increased in cervical cancer (CC) cells and tissues. The down-regulation of MALAT1 by shRNA in CC cells inhibited the invasion and metastasis in vitro and in vivo. Microarray analysis showed that the knockdown of MALAT1 up-regulated the epithelial markers E-cadherin and ZO-1, and down-regulated the mesenchymal markers β-catenin and Vimentin. This regulation was further confirmed by subsequent observation from RT-PCR, western blot, and immunofluorescence results. Meanwhile, the transcription factor snail, which functions to modulate epithelial-mesenchymal transition (EMT), was also down-regulated at both transcript and protein levels by MALAT1 down-regulation. In addition, we found that MALAT1 expression levels were positively related to HPV infection in cervical epithelial tissues by microarray analysis. Taken together, these results suggest that MALAT1 functions to promote cervical cancer invasion and metastasis via induction of EMT, and it may be a target for the prevention and therapy of cervical cancers.

Che XH, Chen CL, Ye XL, et al.
Dual inhibition of COX-2/5-LOX blocks colon cancer proliferation, migration and invasion in vitro.
Oncol Rep. 2016; 35(3):1680-8 [PubMed] Related Publications
Inflammation is emerging as a new hallmark of cancer. Arachidonic acid (AA) metabolism, the family of cyclooxygenases (COXs) and lipoxygenase (LOX) play important roles in AA-related inflammatory cascades. In 94 colorectal cancer samples collected from the Han population, the immunohistochemical results indicated that 68% of the patients with colorectal cancer had a co-expression of both COX-2 and 5-LOX, while both displayed low expression in the matched normal tissues. In cell lines, three colorectal cancer cell lines exhibited high expression of COX-2 and 5-LOX. During stable silencing of the expression of COX-2 or 5-LOX in LoVo cancer cells, we found that downregulation of either COX-2 or 5-LOX significantly diminished the growth, migration and invasion of the colon cancer cells and specifically, downregulation of COX-2 could elicit upregulation of 5-LOX protein and vice versa. The above results suggested that the simultaneous blocking of COX-2 and 5-LOX activity may bring more potential benefits in managing the progression of colon cancer. Therefore, we sought to explore the effectiveness of a dual COX-2/5-LOX inhibitor darbufelone on the proliferation, migration, invasion and apoptosis of colon cancer cells, as well as the underlying mechanism of action. The results indicated that darbufelone significantly decreased the proliferative and invasive abilities of the colon cancer cells, in a dose-dependent manner. During the study of the related mechanisms, we found an upregulation of p27 and downregulation of cyclin D1 as well as CDK4 after darbufelone treatment, which indicated that darbufelone could arrest the cell cycle of LoVo cells at the G0/G1 phase. Furthermore, the activation of caspase-3 and -9, upregulation of Bax and downregulation of Bcl-2 demonstrated the occurrence of apoptosis by darbufelone. Finally, darbufelone also prevented the migration and invasion of LoVo cells, which may be ascribed to the upregulation of E-cadherin and ZO-1. In summary, our data suggest that the inhibition of both COX-2/5-LOX may be an effective therapeutic approach for colon cancer management, particularly for those patients with high expression of COX-2/5-LOX.

Yin Y, Song M, Gu B, et al.
Systematic analysis of key miRNAs and related signaling pathways in colorectal tumorigenesis.
Gene. 2016; 578(2):177-84 [PubMed] Related Publications
The development of colorectal cancers (CRC) is accompanied with the acquisition and maintenance of specific genomic alterations. These alterations can emerge in premalignant adenomas and faithfully maintained in highly advanced tumors. miRNAs are a class of small non-coding RNAs that are frequently deregulated in human cancers and negatively regulate a wide variety of protein coding genes. To identify the sequential alterations of miRNAs and its regulatory networks during CRC development and progression, we detected the miRNA expression profiles of tissue samples from normal colon, colorectal adenoma and CRC using miRNA microarray. qRT-PCR assay was used to validate and select the miRNAs with differential expression among the three groups, and the computer-aided algorithms of TargetScan, miRanda, miRwalk, RNAhybrid and PicTar were used to search for the possible targets of the selected 8 miRNAs (miR-18a, miR-18b, miR-31, miR-142-5p, miR-145, miR-212, miR-451, and miR-638) with continuous alterated expression. These potential target genes were enriched in several key signal transduction pathways (KEGG pathway analysis), which have been proved to be closely related to colorectal tumorigenesis. To confirm the reliability of the analyses, we identified that the metastasis-related gene ZO-1 is a certain target of miR-212 in CRC and keeps declining during CRC progression. By following these analyses, we might gain an in-depth understanding of the molecular regulatory networks of colorectal tumorigenesis and provide new potential targets for the diagnostic and therapeutic interventions of this disease.

Chang JH, Hwang YH, Lee DJ, et al.
MicroRNA-203 Modulates the Radiation Sensitivity of Human Malignant Glioma Cells.
Int J Radiat Oncol Biol Phys. 2016; 94(2):412-20 [PubMed] Related Publications
PURPOSE: We investigated whether miR-203 could modulate the radiation sensitivity of glioblastoma (GBM) cells and which target gene(s) could be involved.
METHODS AND MATERIALS: Three human malignant glioma (MG) cell lines and normal human astrocytes were transfected with control microRNA, pre-miR-203, or antisense miR-203. Real-time PCR (RT-PCR), clonogenic assays, immunofluorescence, and invasion/migration assays were performed. To predict the target(s), bioinformatics analyses using microRNA target databases were performed.
RESULTS: Overexpression of miR-203 increased the radiation sensitivity of all 3 human MG cell lines and prolonged radiation-induced γ-H2AX foci formation. Bioinformatics analyses suggested that miR-203 could be involved in post-transcriptional control of DNA repair, PI3K/AKT, SRC, and JAK/STAT3 and the vascular signaling pathway. Western blot analysis validated the fact that miR-203 downregulated ATM, RAD51, SRC, PLD2, PI3K-AKT, JAK-STAT3, VEGF, HIF-1α, and MMP2. Overexpression of miR-203 inhibited invasion and migration potentials, downregulated SLUG and Vimentin, and upregulated Claudin-1 and ZO1.
CONCLUSIONS: These data demonstrate that miR-203 potentially controls DNA damage repair via the PI3K/AKT and JAK/STAT3 pathways and may collectively contribute to the modulation of radiation sensitivity in MG cells by inhibiting DNA damage repair, prosurvival signaling, and epithelium-mesenchyme transition. Taken together, these findings demonstrate that miR-203 could be a target for overcoming the radiation resistance of GBM.

Feng J, Cen J, Li J, et al.
Histone deacetylase inhibitor valproic acid (VPA) promotes the epithelial mesenchymal transition of colorectal cancer cells via up regulation of Snail.
Cell Adh Migr. 2015; 9(6):495-501 [PubMed] Free Access to Full Article Related Publications
Histone deacetylase inhibitors (HDACIs) have been shown to have antiproliferative activity through cell-cycle arrest, differentiation, and apoptosis in colorectal cancer (CRC) cells. Our present study revealed that one HDAC inhibitor, valproic acid (VPA), can obviously promote in vitro motility of HCT-116 and SW480 cells. VPA treatment significantly down regulates the expression of epithelial markers E-Cadherin (E-Cad) and Zona occludin-1(ZO-1) while up regulates the mesenchymal markers Vimentin (Vim) and N-cadherin (N-Cad), suggesting that VPA can trigger the epithelial-mesenchymal transition (EMT) of CRC cells. VPA treatment significantly increases the expression and nuclear localization of Snail, the key transcription factors of EMT. Snail knockdown by siRNAs obviously reverses VPA induced EMT of HCT-116 and SW480 cells. Further, VPA can decrease the ubiquitination, increase the acetylation, and then elevate the stabilization of Snail. VPA also increases the phosphorylation of Akt/GSK-3β. The inhibitor of PI3K/Akt, LY2994002, significantly attenuates VPA induced phosphorylation of Akt and GSK-3β and up regulation of Snail and Vim. Collectively, our data reveal that VPA can trigger the EMT of CRC cells via up regulation of Snail through AKT/GSK-3β signals and post-transcriptional modification. It suggests that more attention should be paid when VPA used as a new anticancer drug for CRC patients.

Ma J, Wang P, Yao Y, et al.
Knockdown of long non-coding RNA MALAT1 increases the blood-tumor barrier permeability by up-regulating miR-140.
Biochim Biophys Acta. 2016; 1859(2):324-38 [PubMed] Related Publications
The blood-tumor barrier (BTB) forms a major obstacle in brain tumor therapy by preventing the delivery of sufficient quantities of therapeutic drugs. Long non-coding RNAs (lncRNAs) play important roles in both normal development and diseases including cancer. Here, we elucidated the expression of lncRNA metastasis associated lung adenocarcinoma transcript 1 (MALAT1) and defined its functional role in the regulation of BTB function as well as its possible molecular mechanisms. Our results proved that MALAT1 expression was up-regulated in brain microvessels of human glioma and glioma endothelial cells (GECs) which were obtained by co-culturing endothelial cells with glioma cells. Functionally, knockdown of MALAT1 resulted in an impairment and increased the permeability of BTB as well as decreased the expression of ZO-1, occludin and claudin-5 in GECs. Further, there was reciprocal repression between MALAT1 and miR-140, and miR-140 mediated the effects that MALAT1 knockdown exerted. Mechanistic investigations defined that nuclear factor YA (NFYA), a CCAAT box-binding transcription factor, was a direct and functional downstream target of miR-140, which was involved in the MALAT1 knockdown induced regulation of BTB function. Furthermore, NFYA could up-regulate the promoter activities and bind to the promoters of ZO-1, occludin and claudin-5 in GECs. Taken together, we have demonstrated the fact that knockdown of MALAT1 resulted in the increased permeability of BTB, which might contribute to establishing potential therapeutic strategies for human gliomas.

Xie K, Ma H, Liang C, et al.
A functional variant in miR-155 regulation region contributes to lung cancer risk and survival.
Oncotarget. 2015; 6(40):42781-92 [PubMed] Free Access to Full Article Related Publications
Emerging evidence suggested that upregulation of miR-155 could serve as a promising marker for the diagnosis and prognosis of non-small cell lung cancer (NSCLC). In the present study, we genotyped rs767649 (A > T) located in miR-155 regulation region in 1341 cases and 1982 controls, and analyzed the associations of rs767649 with NSCLC risk and survival. Consequently, rs767649 exhibited the significant associations with the risk (adjusted OR = 1.12, 95% CI = 1.01-1.24, P = 0.031) and prognosis of NSCLC (adjusted HR = 1.17, 95% CI = 1.03-1.32, P = 0.014). Meanwhile, rs767649 specifically interacted with radio-chemotherapy (P(int) = 0.013), and patients with both the rs767649-TT genotype and radio-chemotherapy had the highest hazard ratio (adjusted HR = 1.65, 95% CI = 1.26-2.16, P < 0.001). Furthermore, using functional assays and The Cancer Genome Atlas (TCGA) Lung Adenocarcinoma (LUAD) dataset, we found that rs767649 variant allele could increase the transcriptional activity of miR-155, which in turn facilitated tumor growth and metastasis by inhibiting HBP1, TJP1, SMAD5 and PRKAR1A expression. Our findings suggested that rs767649 A > T might contribute to the increased risk and poor prognosis of NSCLC, highlighting the importance of rs767649 in the prevention and therapy of NSCLC.

Yang SH, Lin HY, Changou CA, et al.
Integrin β3 and LKB1 are independently involved in the inhibition of proliferation by lovastatin in human intrahepatic cholangiocarcinoma.
Oncotarget. 2016; 7(1):362-73 [PubMed] Free Access to Full Article Related Publications
Human intrahepatic cholangiocarcinomas are one of the most difficult cancers to treat. In our study, Lovastatin, a 3-hydroxy-3-methylglutaryl-coenzyme-CoA (HMG-CoA) reductase inhibitor, demonstrated anticancer properties by inhibiting cancer cell proliferation, cell migration and cell adhesion. Lovastatin inhibited the expressions of transforming growth factor (TGF)-β1, cyclooxygenase (COX)-2, and intercellular adhesion molecule (ICAM)-1. Furthermore, lovastatin inhibited the expressions of integrin β1 and integrin β3 but not integrin αv or integrin β5. While Lovastatin's inhibitory effects on TGFβ1, COX2, and ICAM-1 expression were independently controlled by the tumor suppressor LKB1, integrin β3 expression was not affected. Lovastatin's inhibitory effect on cell adhesion was associated with the decreased expression of integrin β3 and cell surface heterodimer integrin αvβ3. Quantitative real time PCR, fluorescent microscopy, and cell migration assays all confirmed that Lovastatin inhibits integrin αvβ3 downstream signaling including FAK activation, and β-catenin, vimentin, ZO-1, and β-actin. Overall, Lovastatin reduced tumor cell proliferation and migration by modifying the expression of genes involved in cell adhesion and other critical cellular processes. Our study highlights novel anti-cancer properties of Lovastatin and supports further exploration of statins in the context of cholangiocarcinoma therapy.

Yue B, Qiu S, Zhao S, et al.
LncRNA-ATB mediated E-cadherin repression promotes the progression of colon cancer and predicts poor prognosis.
J Gastroenterol Hepatol. 2016; 31(3):595-603 [PubMed] Related Publications
BACKGROUND: Long non-coding RNA-activated by TGF-β (lncRNA-ATB) promotes the invasion-metastasis cascade in hepatocellular carcinoma via downregulating E-cadherin (E-cad) and inducing epithelial-to- mesenchymal transition (EMT) and is clinically significant in human colon cancer. However, its molecular mechanisms in colon cancer progression remain unclear. This study aimed to elucidate the role of lncRNA-ATB and its clinical value in colon cancer.
METHODS: Expression levels of lncRNA-ATB in colon cancer tissues and colon cancer cell lines were evaluated using quantitative real-time polymerase chain reaction. The clinicopathological significance and prognostic value of lncRNA-ATB were investigated, and roles of lncRNA-ATB in regulating E-cad and other EMT-related markers expression and colon cancer progression were evaluated in vitro. Expression levels of lncRNA-ATB and E-cad in human plasma were evaluated.
RESULTS: Long non-coding RNA-activated by TGF-β was upregulated in colon cancer tissues compared with adjacent mucosa (P < 0.001). LncRNA-ATB levels were also higher in metastatic cancer tissues (P < 0.001). Among the three highly invasive colon cancer cell lines, lncRNA-ATB levels were relatively higher with concurrent low levels of E-cad compared with levels in the three low-invasive cell lines. LncRNA-ATB expression correlated with pN stage (P < 0.01) and American Joint Committee on Cancer stage (P < 0.01). Striking differences were observed in overall survival and disease-free survival in cases with both high lncRNA-ATB expression and low E-cad expression. Reduction of lncRNA-ATB increased expression of epithelial markers E-cad, ZO-1, and decreased expression of mesenchymal markers ZEB1 and N-cadherin (N-cad), and significantly influenced colon cancer cell progression. Plasma lncRNA-ATB was upregulated in colon cancer patients one month after surgery (P < 0.05).
CONCLUSIONS: Long non-coding RNA-activated by TGF-β may act on colon tumorigenesis by suppressing E-cad expression and promoting EMT process, and lncRNA-ATB inhibition may provide a promising therapeutic option for suppressing colon cancer progression.

Jian Y, Chen C, Li B, Tian X
Delocalized Claudin-1 promotes metastasis of human osteosarcoma cells.
Biochem Biophys Res Commun. 2015; 466(3):356-61 [PubMed] Related Publications
Tight junction proteins (TJPs) including Claudins, Occludin and tight junction associated protein Zonula occludens-1 (ZO-1), are the most apical component of junctional complex that mediates cell-cell adhesion in epithelial and endothelial cells. In human malignancies, TJPs are often deregulated and affect cellular behaviors of tumor cells. In this study, we investigated alternations of TJPs and related biological characteristics in human osteosarcoma (OS). Claudin1 was increased in the metastatic OS cells (KRIB and KHOS) compared with the normal osteoblast cells (hFOB1.19) or primary tumor cells (HOS and U2OS), whereas no significant difference was found in Occludin and ZO-1. Immunohistochemistry, immunofluorescence and Western blotting revealed that Claudin1 was initially localized at cell junctions of normal osteoblasts, but substantially delocalized to the nucleus of metastatic OS cells. Phenotypically, inhibition of the nucleus Claudin1 expression compromised the metastatic potential of KRIB and KHOS cells. Moreover, we found that protein kinase C (PKC) but not PKA phosphorylation influenced Claudin1 expression and cellular functions, as PKC inhibitor (Go 6983 and Staurosporine) or genetic silencing of PKC reduced Claudin1 expression and decreased the motility of KRIB and KHOS cells. Taken together, our study implied that delocalization of claudin-1 induced by PKC phosphorylation contributes to metastatic capacity of OS cells.

Zhang X, Yu X, Jiang G, et al.
Cytosolic TMEM88 promotes invasion and metastasis in lung cancer cells by binding DVLS.
Cancer Res. 2015; 75(21):4527-37 [PubMed] Related Publications
Transmembrane protein 88 (TMEM88) is a transmembrane protein that plays a crucial role in regulating human stem cell differentiation and embryonic development. However, its expression and clinicopathologic significance in human neoplasms is unclear. In this study, the expression and subcellular localizations of TMEM88 were assessed in 214 cases of non-small cell lung cancer (NSCLC). Notably, TMEM88 was highly expressed in the cytosol of ∼60% NSCLC specimens examined. Higher expression of cytosolic TMEM88 in NSCLC correlated significantly with poor differentiation, high TNM stage, lymph node metastasis, and inferior survival. In NSCLC cells displaying membrane-localized TMEM88, we observed an inhibition of canonical Wnt signaling due to interactions of TMEM88 with the Wnt pathway factor Dishevelled (DVLS). In contrast, NSCLC cells with cytosol-localized TMEM88 lacked effects on Wnt signaling. Cytosolic interactions of TMEM88 and DVLS increased the expression of phosphorylated, active forms of p38, GSK3β (Thr390), and Snail, thereby reducing the expression of the tight junction-associated proteins ZO-1 and occludin, effects associated with enhanced invasive and metastatic cell characters. Importantly, attenuating the expression of cytosolic TMEM88 reduced metastatic prowess in xenograft models. Overall, our findings show how mislocalization of TMEM88 to the cytosol in NSCLC cells ablates its Wnt pathway regulatory properties, thereby promoting invasion and metastasis by activating the p38-GSK3β-Snail signaling pathway.

Guo XZ, Ye XL, Xiao WZ, et al.
Downregulation of VMP1 confers aggressive properties to colorectal cancer.
Oncol Rep. 2015; 34(5):2557-66 [PubMed] Related Publications
Vacuole membrane protein 1 (VMP1) was recently found to be involved in the process of tumor metastasis and is also considered to play a vital role in balancing apoptosis and autophagy. In the present study, the expression of VMP1 in colorectal cancer and matched adjacent non‑cancerous tissues was evaluated by immunohistochemistry (IHC) for studying the role of VMP1 in the process of colorectal cancer. Kaplan‑Meier analysis and the log-rank test were used to calculate the correlation of classic clinicopathological characteristics related to survival and the expression of VMP1. In vitro, a VMP1 stable gene silencing cell model was constructed using a lentiviral vector. The invasive ability and proliferation of colorectal cancer cells were evaluated by Transwell and MTT assays, respectively, and the underlying signaling pathway was explored by western blotting. Additionally, drug susceptibility to cisplatin, oxaliplatin and 5-FU was tested before and after VMP1 knockout. Finally, an animal model was constructed to explore the role of VMP1 in the physiopathologic process of colorectal cancer. Our results indicated that VMP1 showed increased expression in the adjacent non-cancer tissues compared with that in the colorectal cancer tissues. For different stages of colorectal cancer, expression of VMP1 had a negative correlation with the malignancy of the cancer. In clinical research, we also found that the median survival of patients with low VMP1 expression was much shorter than the survival of patients with high expression. In vitro, after infection with the lentivirus, cells with VMP1 knockout gained significant aggressive properties in regards to invasion and proliferation, and the mechanisms may be related to the activation of the PI3K/Akt/ZO-1/E-cadherin pathway. We also found that shVMP1 cells were more sensitive to 5-FU, but not cisplatin and oxaliplatin. Finally, we found a higher number of formed nodules in nude mice after intraperitoneal injection with shVMP1 cells in the in vivo study.

Nesmiyanov PP, Tolkachev BE, Strygin AV
ZO-1 expression shows prognostic value in chronic B cell leukemia.
Immunobiology. 2016; 221(1):6-11 [PubMed] Related Publications
Connexin-mediated gap junctions are vital for tumor cell function. Intracellular pathways of connexin signaling use Zonula Occludens protein-1 (ZO-1) as an intermediate. This report describes the ZO-1 and connexin 43 (Cx43) expression pattern in lymphocytes from chronic B-cell leukemia (B-CLL) patients. The ZO-1 and Cx43 expression in the B cells of 113 B-CLL patients was identified. Western blot and flow cytometry were used to determine protein expression. Results indicated that ZO-1 and Cx43 expression was reduced and correlated negatively with CD38 and Zap-70 expression. Inhibition of intercellular communication with anti-Cx43 antibodies, 1-octanol, or carbenoxolone resulted in induced cell apoptosis. These data suggest that ZO-1, along with CD38 and Zap-70, plays a role in cell cycle regulation in B-CLL and may be used as a prognostic marker in B-CLL monitoring.

Thion MS, McGuire JR, Sousa CM, et al.
Unraveling the Role of Huntingtin in Breast Cancer Metastasis.
J Natl Cancer Inst. 2015; 107(10) [PubMed] Related Publications
BACKGROUND: Huntingtin (HTT) is mutated in Huntington's disease but is ubiquitously expressed, and mutant HTT influences cancer progression. We investigated wild-type HTT function during breast cancer.
METHODS: We analyzed HTT and ZO1 expression as well as the HTT phosphoserine 421-activated form (S421-P-HTT) in human breast cancer tissues by quantitative reverse transcription polymerase chain reaction and immunohistochemistry. We performed in vitro migration and invasion assays as well as in vivo tail vein injections of the metastatic 4T1 cells in BALB/c mice (n = 11 per group). We analyzed tumor progression in knock-in mice with modified S421 crossed with the MMTV-PyVT mammary cancer model (at least n = 12 per group). Data were analyzed with unpaired t tests, analysis of variance, Pearson or Spearman correlation, and Mann Whitney or Kruskal-Wallis tests. All statistical tests were two-sided.
RESULTS: Levels of HTT and of S421-P-HTT are abnormally low in poorly differentiated and metastatic human breast cancers. HTT expression is downregulated in invasive compared with in situ carcinoma (P < .001). In BALB/c mice, silencing of HTT promotes lung colonization by a metastatic mammary cancer cell line (P = .005) and S421-unphosphorylatable-HTT accelerates cancer progression. HTT interacts with ZO1 and regulates both its expression and its localization to tight junctions. In human breast tumors, the patterns of HTT and ZO1 expression are similar (Pearson correlation coefficient = 0.66, P < .001).
CONCLUSIONS: HTT may inhibit breast tumor dissemination through maintenance of ZO1 at tight junctions. Downregulation of HTT transcript and protein levels is a prognostic factor for poor prognosis and metastasis development.

Tille JC, Ho L, Shah J, et al.
The Expression of the Zonula Adhaerens Protein PLEKHA7 Is Strongly Decreased in High Grade Ductal and Lobular Breast Carcinomas.
PLoS One. 2015; 10(8):e0135442 [PubMed] Free Access to Full Article Related Publications
PLEKHA7 is a junctional protein, which participates in a complex that stabilizes E-cadherin at the zonula adhaerens. Since E-cadherin is involved in epithelial morphogenesis, signaling, and tumor progression, we explored PLEKHA7 expression in cancer. PLEKHA7 expression was assessed in invasive ductal and lobular carcinomas of the breast by immunohistochemistry, immunofluorescence and quantitative RT-PCR. PLEKHA7 was detected at epithelial junctions of normal mammary ducts and lobules, and of tubular and micropapillary structures within G1 and G2 ductal carcinomas. At these junctions, the localization of PLEKHA7 was along the circumferential belt (zonula adhaerens), and only partially overlapping with that of E-cadherin, p120ctn and ZO-1, as shown previously in rodent tissues. PLEKHA7 immunolabeling was strongly decreased in G3 ductal carcinomas and undetectable in lobular carcinomas. PLEKHA7 mRNA was detected in both ductal and lobular carcinomas, with no observed correlation between mRNA levels and tumor type or grade. In summary, PLEKHA7 is a junctional marker of epithelial cells within tubular structures both in normal breast tissue and ductal carcinomas, and since PLEKHA7 protein but not mRNA expression is strongly decreased or lost in high grade ductal carcinomas and in lobular carcinomas, loss of PLEKHA7 is a newly characterized feature of these carcinomas.

Paul A, Danley M, Saha B, et al.
PKCζ Promotes Breast Cancer Invasion by Regulating Expression of E-cadherin and Zonula Occludens-1 (ZO-1) via NFκB-p65.
Sci Rep. 2015; 5:12520 [PubMed] Free Access to Full Article Related Publications
Atypical Protein Kinase C zeta (PKCζ) forms Partitioning-defective (PAR) polarity complex for apico-basal distribution of membrane proteins essential to maintain normal cellular junctional complexes and tissue homeostasis. Consistently, tumor suppressive role of PKCζ has been established for multiple human cancers. However, recent studies also indicate pro-oncogenic function of PKCζ without firm understanding of detailed molecular mechanism. Here we report a possible mechanism of oncogenic PKCζ signaling in the context of breast cancer. We observed that depletion of PKCζ promotes epithelial morphology in mesenchymal-like MDA-MB-231 cells. The induction of epithelial morphology is associated with significant upregulation of adherens junction (AJ) protein E-cadherin and tight junction (TJ) protein Zonula Occludens-1 (ZO-1). Functionally, depletion of PKCζ significantly inhibits invasion and metastatic progression. Consistently, we observed higher expression and activation of PKCζ signaling in invasive and metastatic breast cancers compared to non-invasive diseases. Mechanistically, an oncogenic PKCζ- NFκB-p65 signaling node might be involved to suppress E-cadherin and ZO-1 expression and ectopic expression of a constitutively active form of NFκB-p65 (S536E-NFκB-p65) significantly rescues invasive potential of PKCζ-depleted breast cancer cells. Thus, our study discovered a PKCζ - NFκB-p65 signaling pathway might be involved to alter cellular junctional dynamics for breast cancer invasive progression.

Li J, Yang S, Yan W, et al.
MicroRNA-19 triggers epithelial-mesenchymal transition of lung cancer cells accompanied by growth inhibition.
Lab Invest. 2015; 95(9):1056-70 [PubMed] Related Publications
The miR-19 family (miR-19a and miR-19b-1) are key oncogenic components of the miR-17-92 cluster. Overexpression of miR-19 is strongly associated with cancer invasion and metastasis, and poor prognosis of cancer patients. However, the underlying mechanisms remain largely unknown. In the present study, we found that enforced expression of miR-19 including miR-19a and miR-19b-1 triggered epithelial-mesenchymal transition (EMT) of lung cancer cells A549 and HCC827 as shown by mesenchymal-like morphological conversion, downregulation of epithelial proteins (e.g., E-cadherin, ZO-1 (zona occludens 1), and α-catenin), upregulation of mesenchymal proteins (e.g., vimentin, fibronectin 1, N-cadherin, and snail1), formation of stress fibers, and reduced cell adhesion. In addition, enhanced migration and invasion were observed in the cancer cells A549 and HCC827 undergoing EMT. In contrast, silencing of endogenous miR-19 reversed EMT and reduced the migration and invasion abilities of A549 and HCC827 cells. DNA microarray results revealed significant changes of the expression of genes related to EMT, migration, and metastasis of miR-19-expressing A549 cells. Moreover, siRNA-mediated knockdown of PTEN, a target of miR-19, also resulted in EMT, migration, and invasion of A549 and HCC827 cells, suggesting that PTEN is involved in miR-19-induced EMT, migration and invasion of lung cancer cells. Furthermore, lung cancer cells undergoing EMT induced by miR-19 demonstrated reduced proliferation in vitro and in vivo, and enhanced resistance to apoptosis caused by TNF-α. Taken together, these findings suggest that miR-19 triggers EMT, which has an important role in the invasion and migration of lung cancer cells, accompanied by the reduced proliferation of cells.

Guo X, Wang M, Zhao Y, et al.
Par3 regulates invasion of pancreatic cancer cells via interaction with Tiam1.
Clin Exp Med. 2016; 16(3):357-65 [PubMed] Related Publications
The conserved polarity complex, which comprises partitioning-defective proteins Par3, Par6, and the atypical protein kinase C, affects various cell-polarization events, including assembly of tight junctions. Control of tight junction assembly is closely related to invasion and migration potential. However, as the importance of conserved polarity complexes in regulating pancreatic cancer invasion and metastasis is unclear, we investigated their role and mechanism in pancreatic cancers. We first detect that the key protein of the conserved polarity complex finds that only Par3 is down-regulated in pancreatic cancer tissues while Par6 and aPKC show no difference. What is more, Par3 tissues level was significantly and positively associated with patient overall survival. Knocking-down Par3 promotes pancreatic cancer cells invasion and migration. And Par3 requires interaction with Tiam1 to affect tight junction assembly, and then affect invasion and migration of pancreatic cancer cells. Then, we find that tight junction marker protein ZO-1 and claudin-1 are down-regulated in pancreatic cancer tissues. And the relationship of the expression of Par3 and ZO-1 in pancreatic cancer tissue is linear correlation. We establish liver metastasis model of human pancreatic cancer cells in Balb/c nude mice and find that knocking down Par3 promotes invasion and metastasis and disturbs tight junction assembly in vivo. Taken together, these results suggest that the Par3 regulates invasion and metastasis in pancreatic cancers by controlling tight junction assembly.

Cai H, Xue Y, Wang P, et al.
The long noncoding RNA TUG1 regulates blood-tumor barrier permeability by targeting miR-144.
Oncotarget. 2015; 6(23):19759-79 [PubMed] Free Access to Full Article Related Publications
Blood-tumor barrier (BTB) limits the delivery of chemotherapeutic agent to brain tumor tissues. Long non-coding RNAs (lncRNAs) have been shown to play critical regulatory roles in various biologic processes of tumors. However, the role of lncRNAs in BTB permeability is unclear. LncRNA TUG1 (taurine upregulated gene 1) was highly expressed in glioma vascular endothelial cells from glioma tissues. It also upregulated in glioma co-cultured endothelial cells (GEC) from BTB model in vitro. Knockdown of TUG1 increased BTB permeability, and meanwhile down-regulated the expression of the tight junction proteins ZO-1, occludin, and claudin-5. Both bioinformatics and luciferase reporter assays demonstrated that TUG1 influenced BTB permeability via binding to miR-144. Furthermore, Knockdown of TUG1 also down-regulated Heat shock transcription factor 2 (HSF2), a transcription factor of the heat shock transcription factor family, which was defined as a direct and functional downstream target of miR-144. HSF2 up-regulated the promoter activities and interacted with the promoters of ZO-1, occludin, and claudin-5 in GECs. In conclusion, our results indicate that knockdown of TUG1 increased BTB permeability via binding to miR-144 and then reducing EC tight junction protein expression by targeting HSF2. Thus, TUG1 may represent a useful future therapeutic target for enhancing BTB permeability.

Song X, Han P, Liu J, et al.
Up-regulation of SPOCK1 induces epithelial-mesenchymal transition and promotes migration and invasion in esophageal squamous cell carcinoma.
J Mol Histol. 2015; 46(4-5):347-56 [PubMed] Related Publications
Invasion and metastasis are the major causes of death in patients with esophageal squamous cell carcinoma (ESCC). Recent studies have confirmed that SPARC/osteonectin, cwcv and kazal-like domains proteoglycan 1 (SPOCK1) plays multiple roles in cancer progression. This study aims to explore the clinical characteristics of SPOCK1 in ESCC and its roles in the migration and invasion of ESCC cell lines. In this study, the up-regulation of SPOCK1 expression was frequently detected in primary ESCC tumor tissues compared with those in non-tumor tissues, which was significantly associated with tumor invasion (p = 0.004) and distant metastasis (p = 0.010). SPOCK1 was expressed at higher level in TE13 cells as compared to the low malignant Eca109 and TE1 cells. Overexpression of SPOCK1 in Eca109 cells decreased the expressions of epithelial marker E-cadherin and ZO-1, while increased mesenchymal marker Vimentin and N-cadherin levels. After ectopic expression of SPOCK1, Eca109 cells exhibited a morphological change from an epithelial cobblestone phenotype to an elongated fibroblastic phenotype, concomitant with cytoskeletal rearrangements and increased migration and invasion, suggesting that EMT occurs. While silencing SPOCK1 in TE13 cells had the opposite effects. These results suggest that up-regulation of SPOCK1 in ESCC induces EMT, thus promotes migration and invasion in ESCC cells.

Zhou C, Zheng Y, Li L, et al.
Adrenomedullin promotes intrahepatic cholangiocellular carcinoma metastasis and invasion by inducing epithelial-mesenchymal transition.
Oncol Rep. 2015; 34(2):610-6 [PubMed] Free Access to Full Article Related Publications
Intrahepatic cholangiocellular carcinoma (ICC) is the second most common type of primary liver cancer. However, its etiology and molecular pathogenesis remain largely unknown. The present study aimed to investigate the association between adrenomedullin (ADM) and epithelial-mesenchymal transition (EMT) in ICC and to elucidate the underlying signaling pathway. We evaluated the clinical significance of ADM in 133 ICC patients using tissue microarray analysis of ICC tissues. We also investigated the mechanisms of ADM in ICC EMT-mediated metastasis in cholangiocarcinoma cell lines in vitro. The results revealed that ADM was upregulated in human ICC tissues (73/133) compared with that in healthy controls. ADM expression was positively correlated with shorter overall survival (P<0.01). The characteristics of EMT were induced in vitro by adenoviral transduction of ADM into HuCCT1 cells, resulting in the downregulation of E-cadherin and ZO-1, and the concomitant upregulation of N-cadherin and vimentin. Knockdown of ADM by short hairpin RNA in HUH28 cells expressing high levels of ADM was associated with the reversal of EMT. Functional studies revealed that ADM regulated the activation of ZEB1, which subsequently mediated EMT. The results of the present study suggest that ADM plays an important role in ICC metastasis, and that ADM signaling of EMT may represent a valuable therapeutic target in cancer patients.

Islam SS, Mokhtari RB, Noman AS, et al.
Sonic hedgehog (Shh) signaling promotes tumorigenicity and stemness via activation of epithelial-to-mesenchymal transition (EMT) in bladder cancer.
Mol Carcinog. 2016; 55(5):537-51 [PubMed] Related Publications
Activation of the sonic hedgehog (Shh) signaling pathway controls tumorigenesis in a variety of cancers. Here, we show a role for Shh signaling in the promotion of epithelial-to-mesenchymal transition (EMT), tumorigenicity, and stemness in the bladder cancer. EMT induction was assessed by the decreased expression of E-cadherin and ZO-1 and increased expression of N-cadherin. The induced EMT was associated with increased cell motility, invasiveness, and clonogenicity. These progression relevant behaviors were attenuated by treatment with Hh inhibitors cyclopamine and GDC-0449, and after knockdown by Shh-siRNA, and led to reversal of the EMT phenotype. The results with HTB-9 were confirmed using a second bladder cancer cell line, BFTC905 (DM). In a xenograft mouse model TGF-β1 treated HTB-9 cells exhibited enhanced tumor growth. Although normal bladder epithelial cells could also undergo EMT and upregulate Shh with TGF-β1 they did not exhibit tumorigenicity. The TGF-β1 treated HTB-9 xenografts showed strong evidence for a switch to a more stem cell like phenotype, with functional activation of CD133, Sox2, Nanog, and Oct4. The bladder cancer specific stem cell markers CK5 and CK14 were upregulated in the TGF-β1 treated xenograft tumor samples, while CD44 remained unchanged in both treated and untreated tumors. Immunohistochemical analysis of 22 primary human bladder tumors indicated that Shh expression was positively correlated with tumor grade and stage. Elevated expression of Ki-67, Shh, Gli2, and N-cadherin were observed in the high grade and stage human bladder tumor samples, and conversely, the downregulation of these genes were observed in the low grade and stage tumor samples. Collectively, this study indicates that TGF-β1-induced Shh may regulate EMT and tumorigenicity in bladder cancer. Our studies reveal that the TGF-β1 induction of EMT and Shh is cell type context dependent. Thus, targeting the Shh pathway could be clinically beneficial in the ability to reverse the EMT phenotype of tumor cells and potentially inhibit bladder cancer progression and metastasis.

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