Epithelial-mesenchymal Transition In Colon Cancer Cells Research Articles

BATF is involved in the malignant phenotype and epithelial-mesenchymal transition of colon cancer cells via ERK/PD-L1 signaling.

Transcription factors have emerged as primary regulators in colon cancer. Basic Leucine Zipper Transcription Factor (BATF) was found to be differentially expressed in colon cancer. This study aimed to explore the impact of BATF on the malignant phenotype and epithelial-mesenchymal transition (EMT) process. Based on The Cancer Genome Atlas (TCGA) data, the correlation between BATF and patients' overall prognosis was analyzed. BATF expression in epithelial and colon cancer cells was evaluated. By knocking down its levels in colon cancer cells, its effects on the malignant phenotype, apoptosis, EMT progression, and ERK/PD-L1 were evaluated. Cells were treated with ERK/PD-L1 agonists, and the BATF cell regulation was re-examined. BATF levels were negatively correlated with patients' overall survival. BATF is upregulated in colon cancer cell lines, and BATF knockdown in HCT116 cells suppressed the malignant cellular phenotypes (proliferation, migration, and invasion) and increased apoptosis. BATF knockdown inhibited EMT and ERK/PD-L1 signaling activation, whereas upon agonist treatment, BATF potency was disrupted. This study revealed that BATF is involved in the malignant phenotype and EMT of colon cancer cells, and this process may be mediated by ERK/PD-L1 signaling.

Propofol inhibits colon cancer cell stemness and epithelial-mesenchymal transition by regulating SIRT1, Wnt/β-catenin and PI3K/AKT/mTOR signaling pathways

BackgroundPropofol is a common sedative-hypnotic drug used for general anesthesia. Recent studies have drawn attention to the antitumor effects of propofol, but the potential mechanism by which propofol suppresses colon cancer stemness and epithelial-mesenchymal transition (EMT) has not been fully elucidated.MethodsFor the in vitro experiments, we used propofol to treat LOVO and SW480 cells and Cell Counting Kit-8 (CCK-8) to detect proliferation. Self-renewal capacity, cell invasion and migration, flow cytometry analysis, qPCR and Western blotting were performed to detect the suppression of propofol to colon cancer cells and the underlying mechanism. Tumorigenicity and immunohistochemistry experiments were performed to confirm the role of propofol in vivo.ResultWe observed that propofol could suppressed stem cell-like characteristics and EMT-related behaviors, including self-renewal capacity, cell invasion and migration in colon cancer cells, and even suppressed tumorigenicity in vivo. Furthermore, investigations of the underlying mechanism revealed that propofol treatment downregulated SIRT1. SIRT1 overexpression or knockdown affected the stemness and EMT of colon cancer cells. Additionally, propofol reversed stemness and EMT in cells with overexpressing SIRT1 and subsequently inhibited the Wnt/β-catenin and PI3K/AKT/mTOR signaling pathways. Wnt/β-catenin pathway inhibitor and PI3K/AKT/mTOR pathway inhibitor blocked the propofol-induced reduction of sphere-formation and cell invasion-migration.ConclusionPropofol inhibits LOVO and SW480 cell stemness and EMT by regulating SIRT1 and the Wnt/β-catenin and PI3K/AKT/mTOR signaling pathways. Our findings indicate that propofol inhibits SIRT1 in cancer and is advantageous in colon cancer surgical treatment of patients with high SIRT1 expression.

Anti-oncogenic mechanism of KLF17 in colon cancer by repressing cell migration and invasion via FHL1 upregulation.

Colon cancer is a disease with high prevalence worldwide. This study sought to investigate Kruppel-like factor 17 (KLF17) mechanism in the development of colon cancer through four-and-a-half-LIM domain protein 1 (FHL1). In colon cancer cells, KLF17 and FHL1 expression was detected by reverse transcription-quantitative polymerase chain reaction (RT-qPCR) and Western blot. After gain- and loss-of-function experiments in colon cancer cells, cell proliferative, invasive, and migrating abilities were tested by cell counting kit-8, transwell, and scratch assays, respectively. The expression of epithelial-mesenchymal transition (EMT)-related genes, E-cadherin, N-cadherin, and Vimentin, was measured by RT-qPCR and Western blot. Chromatin immunoprecipitation and dual-luciferase reporter gene assays were performed to detect the binding of KLF17 and the FHL1 promoter. Finally, a transplantation tumor model in nude mice was established for in vivo validation. Mechanistically, KLF17 facilitated FHL1 transcription by binding to the FHL1 promoter. KLF17 or FHL1 upregulation suppressed the colon cancer cell proliferative, invasive, and migrating capacities, accompanied by elevated E-cadherin expression and diminished N-cadherin and Vimentin expression. Furthermore, FHL1 silencing abrogated the repressive impacts of KLF17 upregulation on colon cancer cell EMT, proliferative, invasive, and migrating capabilities. Furthermore, KLF17 augmented FHL1 expression and curtailed the growth of transplanted tumors in nude mice. Conclusively, KLF17 promoted FHL1 transcription, thereby impeding the invasion, migration, and EMT of colon cancer cells.

Effects of curcumin on 5-fluorouracil resistance of colon cancer cells through the PI3K/AKT/mTOR pathway via MACC1

: Colon cancer (CC) represents a common malignancy of the digestive tract featured by high metastasis and recurrence rates. Despite the critical role of 5-fluorouracil (5-Fu) in tumor therapy, long-term and heavy use of 5-Fu leads to reduced treatment efficacy in CC patients. Curcumin can avert multidrug resistance as a sensitizing agent. This study sought to investigate the mechanism of curcumin in 5-Fu resistance of CC cells. : Firstly, the LoVo/5-Fu CC cell line was constructed using gradient 5-Fu, and subjected to treatment with curcumin or oe-MACC1 and pathway inhibitor BEZ235. Cell proliferation was assessed by MTT and clone formation assays, and IC50 values were calculated. Cell apoptosis was evaluated by means of Annexin V-FITC/PI double staining. Levels of drug-resistance factors and Vimentin and E-cadherin were measured using RT-qPCR. Levels of PI3K/AKT/mTOR pathway-associated proteins were determined with a Western blot assay. : LoVo/5-Fu cells presented with increased IC50 value, enhanced proliferation, weakened apoptosis, augmented levels of drug-resistance factors and Vimentin, and diminished E-cadherin levels. MACC1 was highly-expressed and the PI3K/AKT/mTOR-pathway-associated proteins phosphorylated in LoVo/5-Fu cells. Curcumin partly averted 5-Fu resistance and decreased the ratios of p-PI3K/PI3K, p-AKT/AKT, and p-mTOR/mTOR. MACC1 over-expression mitigated the action of curcumin on inhibiting 5-Fu resistance and elevating phosphorylation levels of PI3K/AKT/mTOR proteins. BEZ235 treatment abolished the action of over-expression of MACC1 on 5-Fu resistance of CC cells. : Our findings highlighted that curcumin suppressed the epithelial-mesenchymal transition of CC cells and thus reduced 5-Fu resistance of CC cells by regulating the PI3K/AKT/mTOR pathway via MACC1.

Oct4 promoted proliferation, migration, invasion, and epithelial-mesenchymal transition (EMT) in colon cancer cells by activating the SCF/c-Kit signaling pathway

ABSTRACT Octamer-binding transcription factor 4 (Oct4) is closely related to the occurrence and development of cancer. In the present study, we paid a special interest in exploring the effect of Oct4 on colon cancer (CC) proliferation, migration, invasion, and epithelial-mesenchymal transition (EMT) and its molecular mechanism. Immunohistochemistry (IHC) was used to detect the expression level of Oct4 in colon tissue of patients with colon cancer. Oct4 overexpression vector pcDNA-Oct4 was used to stably express Oct4 in human colon cancer cells HT29 and SW480. Cell counting kit-8 (CCK-8) assay was used to detect the cell proliferation. The invasion and migration abilities were observed by transwell and wound healing assays. The expression of EMT relate genes were observed by Western blot. We found that Oct4 was up-regulated in human colon cancer tissues than that in paracancerous tissues. The proliferation, migration, and invasion of HT29 and SW480 cells was significantly induced by transfection of pcDNA-Oct4. Furthermore, Oct4 overexpression enhanced EMT of CC cells, characterized by the increased expression of vimentin, Twist, and Snail, as well as decreased expression of E-cadherin. Mechanistically, Oct4 overexpression activated stem cell factor (SCF)/c-Kit signaling pathway in CC cells, and the SCF/c-Kit signaling inhibitor imatinib reversed pro-oncogenic effects of Oct4. These finding provide an insight into the potential of Oct4 for CC diagnosis and therapy.

Fangchinoline targets epithelial–mesenchymal transition process by modulating activation of multiple cell‐signaling pathways

Epithelial-mesenchymal transition (EMT) is a key process, which can promote the transition of tumor cells into other organs by weakening the cell-cell junctions. Tumor cell invasion and metastasis arising because of EMT can determine the prognosis of cancer. EMT can be induced by several growth factors including transforming growth factor-β (TGF-β), which can exert their effects by affecting several cell-signaling pathways. Fangchinoline (FCN), a kind of bisbenzylisoquinoline, belongs to the family Menispermaceae. FCN can display substantial antitumor effects against various malignant cell lines but its possible impact on EMT has not been explored. We examined the potential impact of FCN in affecting the activation of EMT in human colon cancer cells. We evaluated the influence of FCN on EMT in colon cancer cells by using Western blot analysis and reverse transcription-polymerase chain reactionassays. The cellular invasion and migration were observed by Boyden chamber and wound healing assays. Thereafter, the effect of the drug on proliferation and invasion was also evaluated by real-time cell analysis. FCN suppressed the levels of TGF-β-induced mesenchymal markers, such as fibronectin, vimentin, MMP-9, MMP-2, N-cadherin, Twist, and Snail. However, FCN markedly enhanced the expression of epithelial markers such as occludin and E-cadherin. These results imply that FCN can potentially inhibit tumor metastasis through abrogating EMT. In addition, FCN downregulated c-Met/PI3K/Akt/mTOR and Wnt/β-catenin cell signaling pathways and mitigated tumor migration as well as invasion. Overall, our study suggests a potential novel role of FCN as an antimetastatic agent against human colon cancer cells.

KAT2A affects tumor metabolic reprogramming in colon cancer progression through epigenetic activation of E2F1.

Lysine acetyltransferase 2 A (KAT2A) has been implicated in tumorigenesis; nevertheless, the mechanism underlying its tumor-initiating effect remains elusive. In the present study, we aimed to identify the possible role of KAT2A in regulating metabolic reprogramming, a hallmark of cancer, in colon cancer (CC). KAT2A was found to be overexpressed in CC and correlated with metastases. KAT2A induced proliferation, migration, invasion, and epithelial-mesenchymal transition of CC cells, along with elevated cellular glycolytic capacity and mitochondrial stress. Functional enrichment analyses predicted and ChIP assays verified that KAT2A activated E2F transcription factor 1 (E2F1) by modifying the acetylation of H3K9. Rescue experiments revealed that E2F1 downregulation inhibited cellular activity, aerobic glycolysis and mitochondrial respiration in CC in the presence of KAT2A. Moreover, KAT2A/E2F1 promoted tumorigenic activity and lung metastases of CC cells in mice. Taken together, our findings demonstrate the substantial role of KAT2A in the modulation of post-translational modifications of E2F1 in CC, suggesting that knockdown of KAT2A may be a potential strategy for CC treatment.

Effects of wogonin on the growth and metastasis of colon cancer through the Hippo signaling pathway

ABSTRACT Wogonin is an effective component of Scutellaria baicalensis Georgi, which exhibits anti-tumor activity. The aim of this study was to explore the effects of wogonin on colon cancer (CC). Human CC cell lines, SW480 and HCT116, were cultured, and MTT assay was performed to detect cell survival. RT-qPCR and Western blotting were used to measure mRNA and protein expression, respectively. The migration and invasion abilities of the CC cells were determined by a transwell assay. Immunofluorescence staining was performed to determine the localization of IRF3. Xenograft mice were used to investigate the effects of wogonin on CC in vivo. Wogonin inhibited the survival and metastasis of CC cells. In addition, wogonin suppressed epithelial-mesenchymal transition (EMT). Furthermore, the protein expression of YAP1 and IRF3 was downregulated, and p-YAP1 was upregulated after wogonin treatment. Wogonin also suppressed IRF3 expression in the nuclei of CC cells and overexpression of YAP1 reversed the effects of wogonin in CC cells. Finally, wogonin inhibited the tumor growth in the mice and overexpression of YAP1 reversed the wogonin effects. Thus, these results showed that wogonin relieved the carcinogenic behaviors and EMT of CC cells via the IRF3-mediated Hippo signaling pathway.

Bevacizumab and anexelekto inhibitor, TP-0903 inhibits TGF-β1-induced epithelial-mesenchymal transition of colon cancer cells.

The incidence of colorectal cancer (CRC) is reported to be increasing nowadays, with a large proportion of newly diagnosed CRC patients being affected by metastasis. Epithelial-mesenchymal transition (EMT) is an important event in the development of metastasis of CRC. In this study, we investigated whether the anticancer drug bevacizumab and anexelekto inhibitor, TP-0903, regulate EMT of colon cancer cells induced by transforming growth factor-beta 1 (TGF-β1). Using quantitative real-time PCR and western blot analysis, we found that bevacizumab and TP-0903 decreased the expression levels of fibronectin, alpha-smooth muscle actin, and vimentin, whereas they restored E-cadherin expression in TGF-β1-exposed SW480 and HCT116 cells. In addition, we elucidated that bevacizumab and TP-0903 inhibited the migration and invasion of TGF-β1-exposed colon cancer cells using scratched wound healing, transwell migration, and Matrigel-coated invasion assays. Finally, we discovered that bevacizumab and TP-0903 inactivated the Smad 2/3 signaling pathway in TGF-β1-exposed SW480 and HCT116 cells. Therefore, we suggest that treatment of bevacizumab and TP-0903 inhibits TGF-β1-induced EMT of colon cancer cells through inactivation of the Smad 2/3 signaling pathway.

LINC01287 facilitates proliferation, migration, invasion and EMT of colon cancer cells via miR-4500/MAP3K13 pathway

BackgroundAccumulated studies indicate that aberrant expression of long noncoding RNAs (lncRNAs) is associated with tumorigenesis and progression of colon cancer. In the present study, long intergenic non-protein coding RNA 1287 (LINC01287) was identified to up-regulate in colon cancer by transcriptome RNA-sequencing, but the exact function remained unclear.MethodsTranscriptome RNA-sequencing was conducted to identify dysregulated lncRNAs. Expression of LINC01287 was evaluated by real-time quantitative PCR. The downstream targets of LINC01287 and miR-4500 were verified by luciferase reporter assay, pull down assay and western blot. The potential functions of LINC01287 were evaluated by cell viability assay, colony formation assay, soft agar assay, flow cytometry, transwell migration and invasion assay, and tumor xenograft growth in colon cancer cells.ResultsOur results indicated that LINC01287 was up-regulated in colon cancer patients. High LINC01287 expression was associated with advanced TNM stage, lymph node metastasis, distant metastasis and shorter overall survival. Knockdown of LINC01287 inhibited cell growth, colony formation in plates and soft agar, transwell cell migration and invasion, and epithelial-mesenchymal transition (EMT) of colon cancer cells, while LINC01287 overexpression had contrary effects. In addition, LINC01287 mediated MAP3K13 expression by sponging miR-4500, thus promoted NF-κB p65 phosphorylation. Restored MAP3K13 expression or miR-4500 knockdown partially abrogated the effects of silencing LINC01287 in colon cancer cells.ConclusionOur findings demonstrated that the LINC01287/miR-4500/MAP3K13 axis promoted progression of colon cancer. Therefore, LINC01287 might be a potential therapeutic target and prognostic marker for colon cancer patients.

Changes of Kinesin Family Member 18 Pathway in Epithelial Mesenchymal Transformation and Effect of Butyrate on Migration and Invasion of Colon Cancer Cells

Colon cancer is a common digestive system disease with an increasing incidence. Severe migration and invasion aggravates the deterioration of colon cancer patients. Previous studies have found that epithelial mesenchymal transition (EMT) is closely associated with early transference of colon carcinoma and abnormal changes occur in KIF18 signaling pathway. Butyrate protects colonic mucosa with a considerable effect on the colon. This study predicts that butyrate may reverse EMT process of colon cancer cells through KIF18 signaling pathway, thereby inhibiting cell migration and invasion. In this experiment, EMT model of colon cancer was used to investigate migration and invasion. Human colon cancer cell line SW1116 was cultured and assigned into control group (0 mmol/L butyrate), low concentration group (2 mmol/L), medium concentration group (4 mmol/L), and high concentration group (10 mmol/L). After 72 hours, cell migration and invasion was analyzed by Transwell assays. E-cadherin, Vimentin, and KIF18 level was detected by Western blot and quantitative real-time PCR. After treatment, cell migration and invasion was significantly inhibited compared to control dose-dependently. In addition, Vimentin and KIF18 mRNA level was significantly lower and E-cadherin mRNA was higher in treatment groups than control group in a dose-dependent manner (P < 0.05). Consistently, the profile of protein level of these molecules was similar to mRNA expression profile. Electron microscope showed that after treatment with butyrate, the surface protuberances of colon cancer cells were abnormally increased, especially the vesicular protuberances, which were the microvilli of intestinal mucosal epithelium. In conclusion, KIF18 is crucial in EMT of colon cancer cells. Butyrate may elevate E-cadherin and suppress Vimentin and KIF18 by activating KIF18 signaling, thus inhibiting invasion and migration.

TNF-α augments CXCL10/CXCR3 axis activity to induce Epithelial-Mesenchymal Transition in colon cancer cell

Chronic inflammation-induced metastases have long been regarded as one of the significant obstacles in treating cancer. Tumor necrosis factor-α (TNF-α), a main inflammation mediator within tumor microenvironment, affects tumor development by inducing multiple chemokines to establish a complex network. Recent reports have revealed that CXCL10/CXCR3 axis affects cancer cells invasiveness and metastases, and Epithelial-mesenchymal transition (EMT) is the main reason for frequent proliferation and distant organ metastases of colon cancer (CC) cells, However, it is unclear whether TNF-α- mediated chronic inflammation can synergically enhance EMT-mediated CC metastasis through promoting chemokine expression. According to this study, TNF-α activated the PI3K/Akt and p38 MAPK parallel signal transduction pathways, then stimulate downstream NF-κB pathway p65 into the nucleus to activate CXCL10 transcription. CXCL10 enhanced the metastases of CC-cells by triggering small GTPases such as RhoA and cdc42. Furthermore, overexpression of CXCL10 significantly enhanced tumorigenicity and mobility of CC cells in vivo. We further clarified that CXCL10 activated the PI3K/Akt pathway through CXCR3, resulting in suppression of GSK-3β phosphorylation and leading to upregulation of Snail expression, thereby regulating EMT in CC cells. These outcomes lay the foundation for finding new targets to inhibit CC metastases.

MiR-370-3p Alleviates Ulcerative Colitis-Related Colorectal Cancer in Mice Through Inhibiting the Inflammatory Response and Epithelial-Mesenchymal Transition.

IntroductionUlcerative colitis (UC) is a chronic and inflammatory bowel disease. UC-associated colorectal cancer (UC-CRC) is one of the most severe complications of long-standing UC. In the present study, we explored the effects of miR-370-3p on UC-CRC in vivo and investigated its underlying mechanisms in vivo and in vitro.MethodsAzoxymethane (AOM) and dextran sodium sulfate (DSS) were used to induce UC-CRC in C57BL/6 mice. AOM/DSS-induced mice were treated with 5×108 pfu miR-370-3p overexpressing-adenovirus via tail-vein injection every two weeks.ResultsWe found that miR-370-3p significantly improved the body weights and survival rates and inhibited the tumorigenesis of UC-CRC in AOM/DSS mice. Mechanically, miR-370-3p inhibited AOM/DSS-induced inflammatory response by decreasing tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β), and interleukin-6 (IL-6) through targeting toll-like receptor 4 (TLR4), as demonstrated by down-regulation of TLR4, cyclooxygenase-2 (COX-2), prostaglandin E2 (PGE2), and phosphorylated epidermal growth factor receptor (pEGFR). miR-370-3p decreased the expression of tumor-associated proteins, including p53, β-catenin, and ki67 in AOM/DSS-treated mice. Additionally, miR-370-3p remarkably inhibited epithelial-mesenchymal transition (EMT) via increasing E-cadherin expression and reducing N-cadherin and Vimentin expression in vivo. Further studies showed that miR-370-3p repressed proliferation and EMT of colon cancer cells in vitro. Moreover, we proved that miR-370-3p decreased the expression of tumor-associated proteins and reversed EMT by regulating β-catenin in colon cancer cells.ConclusionTaken together, miR-370-3p alleviated UC-CRC by inhibiting the inflammatory response and EMT in mice, which suggested miR-370-3p as a novel potential target for UC-CRC therapy.

MicroRNA-377 Counteracts With Cancer Stem Cell Phenotypes and Epithelial Mesenchymal Transformation by Targeting ZEB2 in Colon Cancer.

Dysregulated microRNAs (miRNAs) have been implicated in the pathogenic processes of colon cancer. Epithelial mesenchymal transition (EMT) promotes metastatic progression and cancer stem cells are closely involved in colon cancer proliferation and metastasis. Functional effects of miR-377 on colon cancer stem cell phenotypes and EMT were then determined in the present study. Firstly, reduced miR-377 was found in colon cancer tissues and cell lines. Results from flow cytometry, sphere formation and western blot assays showed that miR-377 knockdown increased number of ALDH+ cells and promoted sphere formation ability. Moreover, cell migration/invasion and EMT of colon cancer cells were suppressed by miR-377 over-expression. On the contrary, miR-377 mimics caused the reversed results. ZEB2 (zinc finger E box-binding homeobox 2) was then validated as a binding target of miR-377. ZEB2 over-expression reversed the inhibitory abilities of miR-377 on cancer stem cell phenotypes, EMT, migration and invasion. In conclusion, miR-377 regulates cancer stem cell phenotypes and EMT in colon cancer cells via regulation of ZEB2, suggesting a new therapeutic strategy for colon cancer treatment.

Down-regulation of lncRNA DNAJC3-AS1 inhibits colon cancer via regulating miR-214-3p/LIVIN axis

ABSTRACT Long non-coding RNAs (lncRNAs) play a key role in the development and metastasis of cancer. However, the biological role and clinical significance of lncRNA DNAJC3-AS1 in the development of colon cancer is still unknown. In this study, the effects of DNAJC3-AS1 on cell proliferation, migration, and invasion were evaluated by MTT assay, wound-healing assay, and transwell assay, respectively. The relationship between DNAJC3-AS1, miR-214-3p and LIVIN was predicted by the online software and confirmed by dual-luciferase reporter assay. We found that the down-regulation of DNAJC3-AS1 inhibited the proliferation of colon cancer cells and induced growth arrest. Down-regulation of DNAJC3-AS1 also inhibited the migration, invasion, and epithelial-mesenchymal transition (EMT) of colon cancer cells. Moreover, miR-214-3p can bind to DNAJC3-AS1, and knockdown of DNAJC3-AS1 increased miR-214-3p expression in colon cancer cells. LIVIN was identified as a target of miR-214-3p. The up-regulation of miR-214-3p inhibited the protein expression of LIVIN and suppressed the activation of the NF-κB signaling pathway. Besides, down-regulation of DNAJC3-AS1 reduced cell viability, invasion, and EMT of colon cancer cells, while miR-214-3p inhibitor could reverse these effects. The expression of LIVIN and the activation of the NF-κB signaling pathway were suppressed by down-regulating DNAJC3-AS1, while these effects could be restored by miR-214-3p inhibitor. These findings suggested that DNAJC3-AS1 may promote colon cancer progression by regulating the miR-214-3p/LIVIN axis. DNAJC3-AS1 may serve as a new biomarker and therapeutic target for colon cancer, stimulating new research directions and treatment options.

TUBB4B Downregulation Is Critical for Increasing Migration of Metastatic Colon Cancer Cells.

Tumor metastasis, the major problem for clinical oncology in colon cancer treatment, is linked with an epithelial-mesenchymal transition (EMT). The observed cellular transformation in this process is manifested by cell elongation, enhanced cell migration and invasion ability, coordinated by cytoskeleton reorganization. In the present study, we examined the role of tubulin-β4 (TUBB4B) downregulation that occurs during EMT in colon cancer cells, in the modulation of the function of microtubules. Based on biochemical and behavioral analysis (transmigration) we posit that the decrease of the TUBB4B level is critical for microtubule-vimentin interaction and contributes to the maintenance of polarity in migrating cells. The microscopic studies revealed that TUBB4B decrease is accompanied by cell elongation and increased number of matured focal adhesion sites, which is a characteristic of the cell metastatic stage. We also demonstrated faster polymerization of microtubules in cells with a lower level of TUBB4B. Simultaneous TUBB3 upregulation, reported during EMT, acts additively in this process. Our studies suggest that the protein level of TUBB4B could be used as a marker for detection of the preinvasive stages of the colon cancer cells. We also concluded that chemotherapy enriched to increase TUBB4B level and/or to stabilize microtubule polymerization might more effectively prevent metastasis in colon cancer development.

Resveratrol inhibits the invasion and metastasis of colon cancer through reversal of epithelial‑ mesenchymal transition via the AKT/GSK‑3β/Snail signaling pathway.

The identification of safe and effective drugs that inhibit tumor invasion and metastasis is required to improve the clinical outcome of patients with colon cancer. The present study aimed to investigate the inhibitory effects and possible mechanisms of action of resveratrol against the invasion and metastasis of colon cancer. AKT1-knockdown SW480 and SW620 colon cancer cells were used to detect the effects of resveratrol on cell invasion and metastasis, as well as changes in the expression of epithelial-mesenchymal transition (EMT) markers and serine/threonine kinase (AKT)/glycogen synthase kinase (GSK)-3β/Snail signaling pathway-related molecules in vitro. Furthermore, nude mice were inoculated with SW480 cells in the tail vein to establish an in vivo lung metastasis model of colon cancer, to investigate the effects of resveratrol on lung metastasis in colon cancer. The results revealed that resveratrol treatment and AKT1 knockdown significantly inhibited cell migration and invasion in colon cancer, and markedly increased E-cadherin expression and decreased that of N-cadherin, phospho (p)-AKT1, p-GSK-3β, and Snail in colon cancer both in vitro and in vivo. Furthermore, the effects of resveratrol were significantly weaker in the AKT1-knockdown cells. In conclusion, resveratrol may suppress the invasion and metastasis of colon cancer through reversal of EMT via the AKT/GSK-3β/Snail signaling pathway. AKT1 may therefore be a key regulator of EMT in colon cancer cells and a potential therapeutic target for this disease.

ACTL6A expression promotes invasion, metastasis and epithelial mesenchymal transition of colon cancer

BackgroundMetastasis is the main cause of death in patients with advanced stage colon cancer. Epithelial mesenchymal transition (EMT) plays an important role in invasion and metastasis. Actin-like 6A (ACTL6A) is vital for embryogenesis and differentiation and is also critical for metastasis and EMT in hepatocellular carcinoma, as observed in our previous study. In the present study, we further explored the role of ACTL6A in colon cancer metastasis.MethodsACTL6A expression levels were analyzed in normal colon, colon adenoma and colon cancer specimens using public databases and tissue samples. ACTL6A expression and its association with clinicopathologic features of colon cancer patients were also analyzed. ACTL6A-overexpression and ACTL6A-knockdown colon cancer cells were used to perform cytological experiments to explore the potential biological function of ACTL6A in metastasis and EMT in colon cancer.ResultsThe data from both the Gene Expression Omnibus (GEO) and Oncomine databases showed that ACTL6A expression levels in colon adenoma and cancer were higher than those in normal colon samples. The ACTL6A expression level in fresh colon cancer specimens was also higher than that in the corresponding adjacent normal colon specimens. Patients with high ACTL6A expression directly correlated with advanced pT status, distant metastasis, poor differentiation and microvascular/perineural invasion. ACTL6A overexpression promoted migration and invasion of colon cancer cells, whereas ACTL6A knockdown exhibited the opposite effect in vitro. Moreover, we demonstrated that ACTL6A promoted EMT in colon cancer cells in vitro.ConclusionsOur findings indicate that ACTL6A exhibits pro-tumor function and acts as an EMT activator in colon cancer. ACTL6A may serve as a potential therapeutic target for colon cancer.

Abstract 492: Downregulation of microRNA-17-5p promotes EMT by targeting vimentin in colorectal cancer

Abstract Background: Colorectal cancer (CRC) is one of the most frequent forms of cancer worldwide. Cells with abnormal growth have the ability to invade or spread to other parts of the body (metastasis). Metastasis is the most common cause of death in CRC patients and activation of epithelial-mesenchymal transition (EMT) triggers metastasis. Thus, it is important to understand the mechanisms of EMT to increase the survival rate of CRC. MicroRNA-17 (miRNA-17) has been proven to be significantly higher in CRC tissues than normal tissues. However, there are few papers about the role of miRNA-17 in CRC metastasis. Therefore, in this study, we evaluated the mechanism underlying miRNA-17-5p related EMT in colon cancer cells. Methods: Expression level of miRNA-17-5p as well as target mRNA were analyzed in HCT-15, HT29, LoVo, SW480 and COLO205 cell lines. In order to evaluate the correlation between miRNA-17-5p and EMT phenomenon, selected cell lines were transiently transfected either miRNA-17-5p mimic or miRNA-17-5p inhibitor and then phenotyping studies were conducted. Moreover, to find out the direct target of miRNA-17-5p, we performed AGO2 immunoprecipitation in each colon cancer cell lines. Results: Real-time PCR revealed that miRNA-17-5p expression reversely correlated with vimentin expression in five colon cancer cell lines. Overexpression of miRNA-17-5p inhibited vimentin expression, cell migration and cell invasion in both LoVo and HT29 cells. On the other hand, inhibition of miRNA-17-5p promoted vimentin expression, cell migration and cell invasion in the same parallel cell lines. Through AGO2 immunoprecipitation analysis, we observed that miRNA-17-5p directly bind to vimentin 3'UTR to influence its stability and expression at the transcriptional level. Conclusion: Our data demonstrated that down-regulated miRNA-17-5p promotes colon cancer cell migration and invasion by regulating vimentin expression. These findings propose that miRNA-17-5p may serve as a potential prognostic biomarker in colorectal cancer. Citation Format: Tea Won Kim, Yeo Song Lee, Hye Kyung Hong, Su Jeong Song, Nak Hyeon Yun, Yong Beom Cho. Downregulation of microRNA-17-5p promotes EMT by targeting vimentin in colorectal cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 492.

α-Hederin inhibits interleukin 6-induced epithelial-to-mesenchymal transition associated with disruption of JAK2/STAT3 signaling in colon cancer cells

Colon cancer is the third most frequently diagnosed malignancy and has high morbidity worldwide. Epithelial-mesenchymal transition (EMT) has been increasingly implicated in colon cancer progression and metastasis. The present study was aimed to evaluate the potential antitumor activity of α-hederin, a monodesmosidic triterpenoid saponin isolated from Hedera helix, in human SW620 colon cancer cells stimulated with interleukin 6 (IL-6) for mimicking the tumor inflammatory microenvironment in vivo. Cell viability assay showed that IL-6 at 6.25 ng/ml significantly enhanced viability of SW620 cells, and thus this concentration was used to stimulate SW620 cells throughout this study. We observed that α-hederin concentration-dependently inhibited cell viability, migration and invasion in IL-6-treated SW620 cells. Moreover, α-hederin significantly restored IL-6-induced decrease in E-cadherin expression and abolished IL-6-induced increase in N-cadherin, vimentin, fibronectin, twist and snail at both mRNA and protein levels in SW620 cells. These data suggested that α-hederin suppressed IL-6-indcued EMT in colon cancer cells. Further molecular examinations showed that α-hederin inhibited phosphorylation of Janus Kinase 2 (JAK2) and Signal Transducer and Activator of Transcription 3(STAT3), and halted the nuclear translocation of phosphorylated STAT3 in IL-6-treated SW620 cells. In addition, JAK2/STAT3 signaling inhibitor AG490 not only produced similar inhibitory effects on EMT markers as α-hederin, but also synergistically enhanced α-hederin’s inhibitory effects on EMT markers in IL-6-treated SW620 cells. Altogether, we demonstrated that α-hederin suppressed IL-6-induced EMT associated with disruption of JAK2/STAT3 signaling in colon cancer cells. Our data strongly suggested α-hederin as a promising candidate for intervention of colon cancer and metastasis.