Effect of atractylenolide Ⅲ on zearalenone-induced Snail1-mediated epithelial–mesenchymal transition in porcine intestinal epithelium

Background The intestinal epithelium performs essential physiological functions,such as nutrient absorption,and acts as a barrier to prevent the entry of harmful substances.Mycotoxins are prevalent contaminants found in ani-mal feed that exert harmful effects on the health of livestock.Zearalenone(ZEA)is produced by the Fusarium genus and induces gastrointestinal dysfunction and disrupts the health and immune system of animals.Here,we evaluated the molecular mechanisms that regulate the effects of ZEA on the porcine intestinal epithelium.Results Treatment of IPEC-J2 cells with ZEA decreased the expression of E-cadherin and increased the expression of Snai1 and Vimentin,which induced Snail1-mediated epithelial-to-mesenchymal transition(EMT).In addition,ZEA induces Snail-mediated EMT through the activation of TGF-βsignaling.The treatment of IPEC-J2 cells with atractyle-nolideⅢ,which were exposed to ZEA,alleviated EMT.Conclusions Our findings provide insights into the molecular mechanisms of ZEA toxicity in porcine intestinal epi-thelial cells and ways to mitigate it.

Human lens epithelial cell apoptosis and epithelial to mesenchymal transition in femtosecond laser-assisted cataract surgery

AIM： To evaluate human lens epithelium cell apoptosis and epithelial to mesenchymal transition （EMT） induced by femtosecond laser in femtosecond laser assisted cataract surgery （FLACS）. METHODS： Sixty cataract patients with N2 to N3 stage according to the LOCS III were enrolled in this study and divided into three groups randomly： FLACSl group （cataract surgery by FLACS with LenSx）, FLACS2 group （cataract surgery by FLACS with LensAR） and manual group （cataract surgery by phacoemulsification）. Patients in two FLACS groups performed anterior capsulotomy by LenSx or LensAR laser system. Patients in the manual group were performed continuous curvilinear capsulorrhexis （CCC） manually. The anterior capsules were fixed right after moved out of eye. Hematoxylin-eosine staining, immunofluorescence staining and real-time PCR were performed in order to observe human lens epithelium cells changes after cataract surgery. RESULTS： The capsule cutting edge was shown irregularity and roughness in two FLACS groups and smooth edge in manual capsulotomy by pathologic staining. Irregularities of the cell configuration with partly swollen and destroyed nuclei were observed in two FLACS groups. Femtosecond laser could induce a significantly higher cell apoptosis in human lens epithelium cell than manually performed CCC （P〈0.05）. Lens epithelium cells apoptosis were correlated with femtosecond laser duration according to Pearson correlation analysis. Decreased N-cadherin expression, alpha-SMA and FSP-1 level in two FLACS groups showed the inhibition of cell EMT. CONCLUSION： Femtosecond laser may affect the apoptosis and EMT of lens epithelium cells which are under the peeled central lens capsule.

Hepatic regeneration and the epithelial to mesenchymal transition

Liver injuries are repaired by fibrosis and regeneration. The core stage is the repair response and fibrosis formation as a scar. The cause of overly-responsive scar formation and diminished regeneration, especially in liver fibrosis and cirrhosis, is still unknown. The epithelial to mesenchymal transition (EMT), a previously discovered mechanism, plays an important role in liver fibrosis and tumor metastasis. Recently, EMT has been found to be associated with liver and bile duct cell fibrosis. Analyzing the established models and chronic disease processes, we propose that EMT liver cells may also lose their regenerative capability due to phenotype changes and that the remaining liver cells may quickly lose their regenerative capability in liver fibrosis or cirrhosis. Recognizing these phenotype changes or transition cells may play an important role in targeting therapy to reverse fibrosis not only by disrupting the transition that is necessary to produce the extracellular matrix but also by restoring the regenerative capacity of EMT-like cells.

Epithelial mesenchymal transition of non-small-cell lung cancer cells A549 induced by SPHK1

Objective:To explore the effect and molecular mechanism of SPHK1 in the invasion and metastasis process of non-small-cell lung cancer cells(A549).Methods:Recombinant retrovirus was used to mediate the production of A549/vector,A549/SPHK1,A549/scramble,and A549/SPHK1/RNAi that stably expressed or silenced SPHK1.The invasion and migration capacities of A549 cells overexpressing or silencing SPHK1 were determined using Transwell invasion assay and scratch wound repair experiment.The protein and mRNA expression levels of E-cadherin,fibronectin,vimentin in A549/vector,A549/SPHK1,A549/scramble,A549/SPHK1/RNAi were detected with Western blot(WB) and quantitative PCR(QPCR) methods,respectively.Results:Transwell invasion assay and scratch wound repair experiments showed that over-expression of SPHK1 obviously enhanced the invasion and migration capacities of A549 cells.WB and QPCR detection results showed that,the expression of E-cadherin(a molecular marker of epithelial cells) and fibronectin,vimentin(molecular markers of mesenchymal cells) in A549 cells was upregulated after overexpression of SPHK1;while SPHK1 silencing significantly reduced the invasion and metastasis capacities of A549 cells,upregulated the expression of molecular marker of epithelial cells,and downregulated the expression of molecular marker of mesenchymal cells.Conclusions:SPHK1 promotes epithelial mesenchymal transition of non-small-cell lung cancer cells and affects the invasion and metastasis capacities of these cells.

Epithelial-mesenchymal transition transcription factors and mi RNAs: “Plastic surgeons” of breast cancer

Growing evidence suggests that breast cancer cell plasticity arises due to a partial reactivation of epithelialmesenchymal transition(EMT) programs in order to give cells pluripotency, leading to a stemness-like phenotype. A complete EMT would be a dead end program that would render cells unable to fully metastasize to distant organs. Evoking the EMT-mesenchymal-toepithelial transition(MET) cascade promotes successful colonization of distal target tissues. It is unlikely that direct reprogramming or trans-differentiation without passing through a pluripotent stage would be thepreferred mechanism during tumor progression. This review focuses on key EMT transcriptional regulators, EMT-transcription factors involved in EMT(TFs) and the mi RNA pathway, which are deregulated in breast cancer, and discusses their implications in cancer cell plasticity. Cross-regulation between EMT-TFs and mi RNAs, where mi RNAs act as co-repressors or co-activators, appears to be a pivotal mechanism for breast cancer cells to acquire a stem cell-like state, which is implicated both in breast metastases and tumor recurrence. As a master regulator of mi RNA biogenesis, the ribonuclease type Ⅲ endonuclease Dicer plays a central role in EMTTFs/mi RNAs regulating networks. All these EMT-MET key regulators represent valuable new prognostic and predictive markers for breast cancer as well as promising new targets for drug-resistant breast cancers.

SFRP4 expression correlates with epithelial mesenchymal transitionlinked genes and poor overall survival in colon cancer patients

BACKGROUND Colon cancer is among the most commonly diagnosed cancers in the United States with an estimated 97220 new cases expected by the end of 2018.It affects 1.2 million people around the world and is responsible for about 0.6 million deaths every year.Despite decline in overall incidence and mortality over the past 30 years,there continues to be an alarming rise in early-onset colon cancer cases(<50 years).Patients are often diagnosed at late stages of the disease and tend to have poor survival.We previously showed that the WNT“gatekeeper”gene,secreted frizzled-related protein 4(SFRP4),is over-expressed in early-onset colon cancer.SFRP4 is speculated to play an essential role in cancer by inhibiting the epithelial mesenchymal transition(EMT).AIM To investigate the correlation between SFRP4 expression and EMT-linked genes in colon cancer and how it affects patient survival.METHODS SFRP4 expression relative to that of EMT-linked genes and survival analysis were performed using the University of California Santa Cruz Cancer Browser interface.RESULTS SFRP4 was found to be co-expressed with the EMT-linked markers CDH2,FN1,VIM,TWIST1,TWIST2,SNAI1,SNAI2,ZEB1,ZEB2,POSTN,MMP2,MMP7,MMP9,and COL1A1.SFRP4 expression negatively correlated with the EMTlinked suppressors CLDN4,CLDN7,TJP3,MUC1,and CDH1.The expression of SFRP4 and the EMT-linked markers was higher in mesenchymal-like samples compared to epithelial-like samples which potentially implicates SFRP4-EMT mechanism in colon cancer.Additionally,patients overexpressing SFRP4 presented with poor overall survival(P=0.0293).CONCLUSION Considering the implication of SFRP4 in early-onset colon cancer,particularly in the context of EMT,tumor metastasis,and invasion,and the effect of increased expression on colon cancer patient survival,SFRP4 might be a potential biomarker for early-onset colon cancer that could be targeted for diagnosis and/or disease therapy.

Role of epithelial-mesenchymal transition in gastric cancer initiation and progression

Gastric cancer is one of the most common malignant tumors worldwide.Due to its intricate initiation and progression mechanisms,early detection and effective treatment of gastric cancer are difficult to achieve.The epithelial-mesenchymal transition(EMT)is characterized as a fundamental process that is critical for embryonic development,wound healing and fibrotic disease.Recent evidence has established that aberrant EMT activation in the human stomach is closely associated with gastric carcinogenesis and tumor progression.EMT activation endows gastric epithelial cells with increased characteristics of mesenchymal cells and reduces their epithelial features.Moreover,mesenchymal cells tend to dedifferentiate and acquire stem cell or tumorigenic phenotypes such as invasion,metastasis and apoptosis resistance as well as drug resistance during EMT progression.There are a number of molecules that indicate the stage of EMT(e.g.,E-cadherin,an epithelial cell biomarker);therefore,certain transcriptional proteins,especially E-cadherin transcriptional repressors,may participate in the regulation of EMT.In addition,EMT regulation may be associated with certain epigenetic mechanisms.The aforementioned molecules can be used as early diagnostic markers for gastric cancer,and EMT regulation can provide potential targets for gastric cancer therapy.Here,we review the role of these aspects of EMT in gastric cancer initiation and development.

Epithelial-mesenchymal transition in breast cancer progression and metastasis

Breast cancer is the most common cancer in women,and approximately 90% of breast cancer deaths are caused by local invasion and distant metastasis of tumor cells.Epithelial-mesenchymal transition(EMT) is a vital process for large-scale cell movement during morphogenesis at the time of embryonic development.Tumor cells usurp this developmental program to execute the multi-step process of tumorigenesis and metastasis.Several transcription factors and signals are involved in these events.In this review,we summarize recent advances in breast cancer researches that have provided new insights in the molecular mechanisms underlying EMT regulation during breast cancer progression and metastasis.We especially focus on the molecular pathways that control EMT.

MiR-200c suppresses the migration of retinoblastoma cells by reversing epithelial mesenchymal transition

AIM： To analyze the relationship between clinical features and epithelial mesenchymal transition （EMT） in retinoblastoma （RB）, further to investigate whether miR-200c regulates the EMT and migration of RB cells. METHODS： Expression of EMT-related markers and tumor- related factors were detected by immuno-histochemistry analysis in RB tissue from 29 cases. Correlations between their expression and clinical characteristics were analyzed. The regulation effects of miR-200c on EMT-related markers, tumor-related factors were observed in mRNA level and protein level by real-time polymerase chain reaction （PCR） and Western blot, respectively, in Y79 and Weri-rbl cells. Its effects on migration force of these RB cell lines were also detected with Transwell test. RESULTS： Lower expression of E-cadherin was present in the cases with malignant prognosis. MiR-200c promoted the expression of E-cadherin and decreased the expression of Vimentin and N-cadherin in Y79 and Weri-rbl cells. Migration force of RB cells could be inhibited by miR-200c. CONCLUSION： EMT might be associated with bad prognosis in RB. MiR-200c suppresses the migration of retinoblastomatous cells by reverse EMT.

Evaluation of epithelial-mesenchymal transitioned circulating tumor cells in patients with resectable gastric cancer: Relevance to therapy response

AIM: To evaluate the epithelial-to-mesenchymal transition(EMT) of circulating tumor cells(CTCs) in gastric cancer patients.METHODS: We detected tumor cells for expression of four epithelial(E^+) transcripts(keratins 8, 18, and 19 and epithelial cell adhesion molecule) and two mesenchymal(M^+) transcripts(Vimentin and Twist) by a quantifiable, dual-colorimetric RNA-in situ hybridization assay. Between July 2014 and October 2014, 44 patients with gastric cancer were recruited for CTC evaluation. Blood samples were obtained from selected patients during the treatment course [before surgery, after surgery and at the 6^(th) cycle of XELOX based chemotherapy(about 6 mo postoperatively)].RESULTS: We found the EMT phenomenon in which there were a few biphenotypic E^+/M^+ cells in primary human gastric cancer specimens. Of the 44 patients, the presence of CTCs was reported in 35(79.5%) patients at baseline. Five types of cells including from exclusively E^+ CTCs to intermediate CTCs and exclusively M^+ CTCs were identified(4 patients with M^+ CTCs and 10 patients with M^+ or M^+ > E^+ CTCs). Further, a chemotherapy patient having progressive disease showed a proportional increase of mesenchymal CTCs in the post-treatment blood specimens. We used NCI-N87 cells to analyze the linearity and sensitivity of Can Patrol^(TM) system and the correlation coefficient(R^2) was 0.999.CONCLUSION: The findings suggest that the EMT phenomenon was both in a few cells of primary tumors and abundantly in CTCs from the blood of gastric cancer patients, which might be used to monitor therapy response.

Attenuated LKB1-SIK1 signaling promotes epithelial-mesenchymal transition and radioresistance of non–small cell lung cancer cells

Background: Radiotherapy is one of the main therapeutic approaches for non–small cell lung cancer(NSCLC). However, radioresistant cancer cells can eventually cause tumor relapse and even fatal metastasis. It is thought that radioresistance and metastasis could be potentially linked by epithelial?mesenchymal transition(EMT). In this study, we established radioresistant NSCLC cells to investigate the potential relationship among radioresistance, EMT, and enhanced metastatic potential and the underlying mechanism involving liver kinase B1(LKB1)?Salt?inducible kinase 1(SIK1) signaling.Methods: The radioresistant cell lines A549 R and H1299 R were generated by dose?gradient irradiation of the paren?tal A549 and H1299 cells. The radioresistance/sensitivity was evaluated by Cell Counting Kit?8 assay, apoptosis analysis, and/or clonogenic cell survival assay. The EMT phenotype and the signaling change were assessed by Western blot?ting. The abilities of invasion and migration were evaluated by transwell assays and wound healing assays.Results: The radioresistant cell lines A549 R and H1299 R displayed mesenchymal features with enhanced invasion and migration. Mechanistically, A549 R and H1299 R cells had attenuated LKB1?SIK1 signaling, which leaded to the up?regulation of Zinc?finger E?box?binding homeobox factor 1(ZEB1)—a transcription factor that drives EMT. Re?expression of LKB1 in A549 R cells reversed the EMT phenotype, whereas knockdown of LKB1 in H1299 R cells further promoted the EMT phenotype. Moreover, re?expression of LKB1 in A549 cells increased the radiosensitivity, whereas knockdown of LKB1 in H1299 cells decreased the radiosensitivity.Conclusions: Our findings suggest that attenuated LKB1?SIK1 signaling promotes EMT and radioresistance of NSCLC cells, which subsequently contributes to the enhanced metastatic potential. Targeting the LKB1?SIK1?ZEB1 pathway to suppress EMT might provide therapeutic benefits.

Epithelial-mesenchymal transition- activating transcription factors- multifunctional regulators in cancer

The process of epithelial to mesenchymal transition(EMT), first noted during embryogenesis, has also been reported in tumor formation and leads to the development of metastatic growth. It is a naturally occurring process that drives the transformation of adhesive,non-mobile epithelial like cells into mobile cells with a mesenchymal phenotype that have ability to migrate to distant anatomical sites. Activating complex network of embryonic signaling pathways, including Wnt, Notch,hedgehog and transforming growth factor-β pathways,lead to the upregulation of EMT activating transcription factors, crucial for normal tissue development and maintenance. However, deregulation of tightly regulated pathways affecting the process of EMT has been recently investigated in various human cancers. Given the critical role of EMT in metastatic tumor formation,better understanding of the mechanistic regulation provides new opportunities for the development of potential therapeutic targets of clinical importance.

Systematic review of the old and new concepts in the epithelial-mesenchymal transition of colorectal cancer

Epithelial-to-mesenchymal transition(EMT) is defined as the transformation of an epithelial cell into a spindle cell with the loss of membrane E-cadherin expression and the gain of mesenchymal markers positivity. In the field of colorectal cancer(CRC), first data about EMT was published in 1995 and more than 400 papers had been written up to March 2016. Most of them are focused on the molecular pathways and experimentally-proved chemoresistance. In the present article, an update in the field of EMT in CRC based on the review of the literature and personal experience of the authors is presented. The information about the molecular and immunohistochemical(IHC) particularities of these processes and their possible role in the prognosis of CRC were also up-dated. This article focuses on the IHC quantification of the EMT, the immunoprofile of tumor buds and on the relation between EMT, angiogenesis, and stem cells activation. The EMT-induced chemoresistance vs chemotherapyor radiotherapy-induced EMT and cellular senescence was also synthesized for both conventional and targeted therapy. As a future perspective, the EMTangiogenesis-stemness link could be used as a possible valuable parameter for clinical follow-up and targeted therapeutic oncologic management of patients with CRC. Association of dexamethasone and angiotensin converting enzyme inhibitors combined with conventional chemotherapies could have clinical benefits in patients with CRC. The main conclusion is that, although many studies have been published, the EMT features are still incompletely elucidated and newly discovered EMT markers provide confusing data in understanding this complicated process, which might have significant clinical impact.

Cullin 4A is associated with epithelial to mesenchymal transition and poor prognosis in perihilar cholangiocarcinoma

AIM To explore the functional role of cullin 4A(CUL4A), a core subunit of E3 ubiquitin ligase, in perihilar cholangiocarcinoma(PHCC).METHODS The expression of CUL4 A in PHCC cell lines was evaluated by Western blot and quantitative reverse transcription-polymerase chain reaction. Immunohistochemistry(IHC) was adopted to investigate the relationship between CUL4 A expression and clinicopathological characteristics of PHCC. Univariate analysis and multivariate regression analysis were performed to analyze the risk factors related to overall survival(OS) and progression-free survival(PFS) of PHCC patients. Wound healing, Transwell and Matrigel assays were utilized to explore the function of CUL4 A in PHCC metastasis. Furthermore, expression of epithelial to mesenchymal transition(EMT) markers was verified in cells with CUL4 A knockdown or overexpression. The relationship between CUL4 A expression and E-cadherin expression was also analyzed by IHC assay. Finally, the role of ZEB1 in regulating CUL4 A mediated PHCC was detected by IHC, Western blot, Transwell and Matrigel assays.RESULTS CUL4 A overexpression was detected in PHCC cell lines and clinical specimens. Clinicopathological analysis revealed a close correlation between CUL4 A overexpression and tumour differentiation, T, N and TNM stages in PHCC. Kaplan-Meier analysis revealed that high CUL4 A expression was correlated with poor OS and PFS of PHCC patients. Univariate analysis identified the following four parameters as risk factors related to OS rate of PHCC: T, N, TNM stages and high CUL4 A expression; as well as three related to PFS: N stage, TNM stage and high CUL4 A expression. Further multivariate logistic regression analysis identified high CUL4 A expression as the only independent prognostic factor for PHCC. Moreover, CUL4 A silencing in PHCC cell lines dramatically inhibited metastasis and the EMT. Conversely, CUL4 A overexpression promoted these processes. Mechanistically, ZEB1 was discovered to regulate the function of CUL4 A in promoting the EMT and metastasis.CONCLUSION CUL4 A is an independent prognostic factor for PHCC, and it can promote the EMT by regulating ZEB1 expression. CUL4 A may be a potential therapeutic target for PHCC.

Targeting tight junctions during epithelial to mesenchymal transition in human pancreatic cancer

Pancreatic cancer continues to be a leading cause of cancer-related death worldwide and there is an urgent need to develop novel diagnostic and therapeutic strategies to reduce the mortality of patients with this disease. In pancreatic cancer, some tight junction proteins, including claudins, are abnormally regulated and therefore are promising molecular targets for diagnosis, prognosis and therapy. Claudin-4 and-18 are overexpressed in human pancreatic cancer and its precursor lesions. Claudin-4 is a high affinity receptor of Clostridium perfringens enterotoxin(CPE). The cytotoxic effects of CPE and monoclonal antibodies against claudin-4 are useful as novel therapeutic tools for pancreatic cancer. Claudin-18 could be a putative marker and therapeutic target with prognostic implications for patients with pancreatic cancer. Claudin-1,-7, tricellulin and marvelD3 are involved in epithelial to mesenchymal transition(EMT) of pancreatic cancer cells and thus might be useful as biomarkers during disease. Protein kinase C is closely related to EMT of pancreatic cancer and regulates tight junctions of normal human pancreatic duct epithelial cells and the cancer cells. This review focuses on the regulation of tight junctions via protein kinase C during EMT in human pancreatic cancer for the purpose of developing new diagnostic and therapeutic modalities for pancreatic cancer.

Mechanisms of fibrogenesis in liver cirrhosis:The molecular aspects of epithelial-mesenchymal transition

Liver injuries are repaired by fibrosis and regeneration.The cause of fibrosis and diminished regeneration,especially in liver cirrhosis,is still unknown.Epithelialmesenchymal transition(EMT) has been found to be associated with liver fibrosis.The possibility that EMT could contribute to hepatic fibrogenesis reinforced the concept that activated hepatic stellate cells are not the only key players in the hepatic fibrogenic process and that other cell types,either hepatic or bone marrow-derived cells could contribute to this process.Following an initial enthusiasm for the discovery of this novel pathway in fibrogenesis,more recent research has started to cast serious doubts upon the real relevance of this phenomenon in human fibrogenetic disorders.The debate on the authenticity of EMT or on its contribution to the fibrogenic process has become very animated.The overall result is a general confusion on the meaning and on the definition of several key aspects.The aim of this article is to describe how EMT participates to hepatic fibrosis and discuss the evidence of supporting this possibility in order to reach reasonable and useful conclusions.

Inflammatory microenvironment contributes to epithelial-mesenchymal transition in gastric cancer

Gastric cancer(GC) is the fifth most common malignancy in the world. The major cause of GC is chronic infection with Helicobacter pylori(H. pylori). Infection with H. pylori leads to an active inflammatory microenvironment that is maintained by immune cells such as T cells, macrophages, natural killer cells, among other cells. Immune cell dysfunction allows the initiation and accumulation of mutations in GC cells, inducing aberrant proliferation and protection from apoptosis. Meanwhile, immune cells can secrete certain signals, including cytokines, and chemokines, to alter intracellular signaling pathways in GC cells. Thus, GC cells obtain the ability to metastasize to lymph nodes by undergoing the epithelial-mesenchymal transition(EMT), whereby epithelial cells lose their epithelial attributes and acquire a mesenchymal cell phenotype. Metastasis is a leading cause of death for GC patients, and the involved mechanisms are still under investigation. In this review, we summarize the current research on how the inflammatory environment affects GC initiation and metastasis via EMT.

p38 MAPK is Crucial for Wnt1- and LiCl-Induced Epithelial Mesenchymal Transition

Idiopathic pulmonary fibrosis （IPF） is characterized by myofibroblast loci in lung parenchyma. Myofibroblasts are thought to originate from epithelial-to-mesenchymal transition （EMT）. Wntl and lithium chloride （LiCl） induce EMT in alveolar epithelial cells （AECs）, but the mechanisms are unclear. AECs were treated with Wntl and LiC1, respectively; morphological change and molecular changes of EMT, including E-cadherin, fibronectin, and vimentin, were observed. SB203580 was administrated to test the role of p38 MAPK signaling in EMT. Then AECs were treated with siRNAs targeting p38 MAPK to further test the effects of p38 MAPK, and the role was further confirmed by re-expression of p38 MAPK. At last β-catenin siRNA was used to test the role of β-catenin in the EMT process and relationship of β-catenin and p38 MAPK was concluded. Exposure of AECs to Wntl and LiC1 resulted in upregulation of vimentin and fibronectin with subsequent downregulation of E-cadherin. Wntl and LiC1 stimulated the p38 MAPK signaling pathways. Perturbing the p38 MAPK pathway either by SB203580 or through p38 MAPK siRNA blocked EMT and inhibited fibronetin synthesis, which were reversed by transfection of p38 MAPK expression plasmid. β-catenin siRNA attenuated the EMT process and decreased p38 MAPK phosphorylation, indicating that β-catenin is involved in the EMT- related changes through regulation of p38 MAPK phosphorylation. These findings suggest that p38 MAPK participates in the pathogenesis of EMT through Wnt pathway and that p38 MAPK may be a novel target for IPF therapy.

GSK3β inhibits epithelial-mesenchymal transition via the Wnt/β-catenin and PI3K/Akt pathways

AIM： To investigate the regulatory mechanism of glycogen synthase kinase 3β（GSK3β） in epithelialmesenchymal transition（EMT） process after proliferative vitreoretinopathy（PVR） induction. METHODS： Experimental PVR was induced by intravitreal injection of retinal pigment epithelium（RPE） cells in the eyes of rabbits. A PI3 K/Akt inhibitor（wortmannin） and a GSK3β inhibitor（Li Cl） were also injected at different time during PVR progress. Electroretinogram（ERG）, ocular fundus photographs, and B-scan ultrasonography were used to observe the PVR progress. Western blot test on the extracted retina were performed at 1, 2, 4 wk. The expression of the mesenchymal marker vimentin was determined by immunohistochemistry. Toxicity of wortmannin and Li Cl were evaluated by ERG and Td Tmediated d UTP nick-end labeling（TUNEL） assay. The vitreous was also collected for metabolomic analysis. RESULTS： Experimental PVR could significantly lead to EMT, along with the suppressed expression of GSK3β and the activation of Wnt/β-catenin and PI3 K/Akt pathways. It was verified that upregulating the expression of GSK3β could effectively inhibit EMT process by suppressing Wnt/β-catenin and PI3 K/Akt pathways. CONCLUSION： GSK3β effectively inhibits EMT via the Wnt/β-catenin and PI3 K/Akt pathways. GSK3β may be regarded as a promising target of experimental PVR inhibition.

KAI1 reverses the epithelial-mesenchymal transition in human pancreatic cancer cells

Background: Epithelial-mesenchymal transition (EMT) plays an important role in pancreatic cancer (PC). In the present study, we investigated the effects of KAI1 gene overexpression on the EMT of human PC cell lines, MIA PaCa-2 and PACN-1. Methods: Plasmids overexpressing KAI1 and pCMV were transfected into MIA PaCa-2 and PACN-1 cells, respectively. After selection of differently transfected cells by G418, KAI1 protein levels were examined by Western blotting, and transfected cells were renamed as MIA PaCa-2-K, MIA PaCa-2-p, PACN-1-K and PACN-1-p. Wound healing and Transwell migration assays were then performed comparing the two groups of cells. EMT-related markers were analyzed by Western blotting. Results: The percentage of wound closure significantly decreased in MIA PaCa-2-K cells compared with MIA PaCa-2-p and MIA PaCa-2 cells after 24, 48 and 72 h ( P < 0.05). In PACN-1-K cells, the percentage of wound closure significantly decreased as well ( P < 0.05). Numbers of invading MIA PaCa-2, MIA PaCa-2-p and MIA PaCa-2-K cells were determined as 48.0 ±15.4, 50.0 ±12.4, and 12.0 ±3.8, respectively. The corresponding numbers of invading PACN-1, PACN-1-p and PACN-1-K cells were 29.0 ±10.6, 31.0 ±11.4, and 8.0 ±4.2, respectively. KAI1 overexpression induced a significant upregulation of E-cadherin and also significant downregulation of Snail, vimentin, matrix metalloproteinase 2 (MMP2) and MMP9 (all P < 0.05) in PC cells. Conclusions: KAI1 reversed EMT-related marker expression and inhibited migration and invasion of PC cells. Thus, KAI1 might represent a novel potential therapeutic target for PC.