E-cadherin and the cytoskeletal network in colorectal cancer development and metastasis

Pseudogene CSPG4P12 inhibits colorectal cancer progression by attenuating epithelial-mesenchymal transition

Colorectal cancer is one of the most common malignant cancers. Pseudogenes have been identified as oncogenes or tumor suppressor genes in the development of various cancers. However, the function of pseudogene CSPG4P12 in colorectal cancer remains unclear. Therefore, the aim of this study was to investigate the potential role of CSPG4P12 in colorectal cancer and explore the possible underlying mechanism. The difference of CSPG4P12 expression between colorectal cancer tissues and adjacent normal tissues was analyzed using the online Gene Expression Profiling Interactive Analysis 2 (GEPIA2) database. Cell viability and colony formation assays were conducted to evaluate cell viability. Transwell and wound healing assays were performed to assess cell migration and invasion capacities. Western blot was used to measure the expression levels of epithelial-mesenchymal transition-related proteins. Colorectal cancer tissues had lower CSPG4P12 expression than adjacent normal tissues. The overexpression of CSPG4P12 inhibited cell proliferation, invasion, and migration in colorectal cancer cells. Overexpressed CSPG4P12 promoted the expression of E-cadherin, whereas it inhibited the expression of vimentin, N-cadherin, and MMP9. These findings suggested that CSPG4P12 inhibits colorectal cancer development and may serve as a new potential target for colorectal cancer.

The Actin Crosslinker Fascin Regulates Cell Chirality

The left-right (L-R) asymmetry of the cells, or cell chirality, is a well-known intrinsic property derived from the dynamic organization of the actin cytoskeleton. Cell chirality can be regulated by actin-binding proteins such as α-actinin-1 and can also be mediated by certain signaling pathways, such as protein kinase C (PKC) signaling. Fascin, an actin crosslinker known to mediate parallel bundling of actin filaments, appears as a prominent candidate in cell chirality regulation, given its role in facilitating cell migration as an important PKC substrate. Here, it is shown that the chirality of NIH/3T3 cells can be altered by PKC activation and fascin manipulation. With either small-molecule drug inhibition or genetic knockdown of fascin, the chirality of 3T3 cells is reversed from a clockwise (CW) bias to a counterclockwise (CCW) bias on ring-shaped micropatterns, accompanied by the reversal in cell directional migration. The Ser-39 fascin-actin binding sites are further explored in cell chirality regulation. The findings of this study reveal the critical role of fascin as an important intermediator in cell chirality, shedding novel insights into the mechanisms of L-R asymmetric cell migration and multicellular morphogenesis.

Clinical and prognostic features of E-cadherin in adenocarcinoma of the esophagogastric junction patients

OBJECTIVE

The expression, activity, and functional role of E-cadherin in adenocarcinoma of the esophagogastric junction (AEG) are unclear. In this research, we evaluated the expression of E-cadherin in AEG, as well as its clinicopathological significance and prognostic value.

METHODS

A total of 65 AEG samples and 10 normal paracancerous tissues undergoing AEG resection in thoracic surgery were collected. The samples were immunohistochemically examined for expression levels of E-cadherin. The Chi-square test was used to determine if E-cadherin expression correlated with the clinicopathological features of AEG patients. The link between clinicopathological features and 5-year survival rates was investigated using Kaplan-Meier survival curves and multifactorial Cox regression analysis.

RESULTS

In AEG tissues, E-cadherin expression was considerably reduced. Differentiation grade ( P = 0.013), infiltration depth ( P = 0.033), and clinicopathological stage ( P = 0.045) were substantially linked to the level of E-cadherin expression. Five-year survival rates of AEG patients were affected by E-cadherin expression ( P = 0.037), tumor differentiation ( P = 0.010), lymph node metastasis ( P < 0.001), and clinicopathological stage ( P = 0.037). Tumor differentiation ( P = 0.033) and lymph node metastasis ( P = 0.001) were independent risk factors for shorter overall survival.

CONCLUSION

E-cadherin expression in AEG was significantly decreased, which was strongly related to tumor differentiation, infiltration, and clinicopathological stage. An E-cadherin deficiency would lead to poor prognosis in AEG patients. E-cadherin may play a crucial role in AEG invasion and metastasis. Low expression of E-cadherin may be a potential early biomarker and overall survival predictor for AEG patients.

Broad misappropriation of developmental splicing profile by cancer in multiple organs

Oncogenesis mimics key aspects of embryonic development. However, the underlying mechanisms are incompletely understood. Here, we demonstrate that the splicing events specifically active during human organogenesis, are broadly reactivated in the organ-specific tumor. Such events are associated with key oncogenic processes and predict proliferation rates in cancer cell lines as well as patient survival. Such events preferentially target nitrosylation and transmembrane-region domains, whose coordinated splicing in multiple genes respectively affect intracellular transport and N-linked glycosylation. We infer critical splicing factors potentially regulating embryonic splicing events and show that such factors are potential oncogenic drivers and are upregulated specifically in malignant cells. Multiple complementary analyses point to MYC and FOXM1 as potential transcriptional regulators of critical splicing factors in brain and liver. Our study provides a comprehensive demonstration of a splicing-mediated link between development and cancer, and suggest anti-cancer targets including splicing events, and their upstream splicing and transcriptional regulators.

Exosomes derived from bone marrow mesenchymal stem cells reverse epithelial-mesenchymal transition potentially via attenuating Wnt/β-catenin signaling to alleviate silica-induced pulmonary fibrosis

Pulmonary fibrosis induced by silica dust is an irreversible, chronic, and fibroproliferative lung disease with no effective treatment at present. BMSCs-derived exosomes (BMSCs-Exo) possess similar functions to their parent cells. In this study, we investigated the therapeutic potential and underlying molecular mechanism for BMSCs-Exo in the treatment of silica-induced pulmonary fibrosis. The rat model of experimental silicosis pulmonary fibrosis was induced with 1.0 mL of one-off infusing silica suspension using the non-exposed intratracheal instillation (50 mg/mL/rat). In vivo transplantation of BMSCs-Exo effectively alleviated silica-induced pulmonary fibrosis, including a reduction in collagen accumulation, inhibition of TGF-β1, and decreased HYP content. Treatment of BMSCs-Exo increased the expression of epithelial marker proteins including E-cadherin (E-cad) and cytokeratin19 (CK19) and reduced the expression of fibrosis marker proteins including α-Smooth muscle actin (α-SMA) after exposure to silica suspension. Furthermore, we found that BMSCs-Exo inhibited the expression of Wnt/β-catenin pathway components (P-GSK3β, β-catenin, Cyclin D1) in pulmonary fibrosis tissue. BMSCs-Exo is involved in the alleviation of silica-induced pulmonary fibrosis by reducing the level of profibrotic factor TGF-β1 and inhibiting the progression of epithelial-mesenchymal transition (EMT). Additionally, attenuation of the Wnt/β-catenin signaling pathway closely related to EMT may be one of the mechanisms involved in anti-fibrotic effects of exosomes.

Assessing the potential value and mechanism of Ginkgo biloba L. On coal-fired arsenic-induced skin damage: In vitro and human evidence

Exposure through arsenic-contaminated air and food caused by the burning of coal is a major environmental public health concern in Guizhou Province of China. Previous studies have shown that immunological dysfunction is involved in the pathogenesis and carcinogenesis of arsenic; however, knowledge regarding effective prevention measures have not been fully examined. The effect of Ginkgo biloba extract (EGb761) on arsenic-induced skin damage of human immortalized keratinocyte cells (HaCaT) was first evaluated in this study. The results showed that 200 μg/mL EGb761 can reduce the expression of miR-155-5p, and the indicators reflecting arsenic-induced skin damage (Krt1, Krt6c and Krt10) in arsenic-exposed cells (P < 0.05), the expression levels of NF-AT1; the indicators reflecting arsenic-induced immunological dysfunction (IL-2, IFN-γ) in cells; and the levels of secreted IL-2 and IFN-γ in cell supernatants were significantly increased (P < 0.05). Further randomized controlled double-blind experiments showed that compared to the placebo control group, the expression level of miR-155-5p in the plasma of the Ginkgo biloba intervention group, the indicators in the serum reflecting arsenic-induced skin damage (Krt1, Krt6c, and Krt10) and the epithelial-mesenchymal transformation (EMT) vimentin were significantly reduced (P < 0.05), but the levels of NF-AT1 and the indicators reflecting arsenic-induced immunological dysfunction (IL-2, IFN-γ) and EMT (E-cadherin) in serum were significantly increased (P < 0.05). Our study provides some limited evidence that Ginkgo biloba L. can increase the expression of NF-AT1 by downregulating the level of miR-155-5p, alleviating immunological dysfunction, and decreasing the expression of EMT biomarkers, thus indirectly improving arsenic-induced skin damage.

Cryo-EM structure of the Hippo signaling integrator human STRIPAK

The striatin-interacting phosphatase and kinase (STRIPAK) complex is a large, multisubunit protein phosphatase 2A (PP2A) assembly that integrates diverse cellular signals in the Hippo pathway to regulate cell proliferation and survival. The architecture and assembly mechanism of this critical complex are poorly understood. Using cryo-EM, we determine the structure of the human STRIPAK core comprising PP2AA, PP2AC, STRN3, STRIP1, and MOB4 at 3.2-Å resolution. Unlike the canonical trimeric PP2A holoenzyme, STRIPAK contains four copies of STRN3 and one copy of each the PP2AA-C heterodimer, STRIP1, and MOB4. The STRN3 coiled-coil domains form an elongated homotetrameric scaffold that links the complex together. An inositol hexakisphosphate (IP₆) is identified as a structural cofactor of STRIP1. Mutations of key residues at subunit interfaces disrupt the integrity of STRIPAK, causing aberrant Hippo pathway activation. Thus, STRIPAK is established as a noncanonical PP2A complex with four copies of regulatory STRN3 for enhanced signal integration.

Role of Cadherins in Cancer-A Review

Cadherins play an important role in tissue homeostasis, as they are responsible for cell-cell adhesion during embryogenesis, tissue morphogenesis, differentiation and carcinogenesis. Cadherins are inseparably connected with catenins, forming cadherin-catenin complexes, which are crucial for cell-to-cell adherence. Any dysfunction or destabilization of cadherin-catenin complex may result in tumor progression. Epithelial mesenchymal transition (EMT) is a mechanism in which epithelial cadherin (E-cadherin) expression is lost during tumor progression. However, during tumorigenesis, many processes take place, and downregulation of E-cadherin, nuclear β-catenin and p120 catenin (p120) signaling are among the most critical. Additional signaling pathways, such as Receptor tyrosine kinase (RTK), Rho GTPases, phosphoinositide 3-kinase (PI3K) and Hippo affect cadherin cell-cell adhesion and also contribute to tumor progression and metastasis. Many signaling pathways may be activated during tumorigenesis; thus, cadherin-targeting drugs seem to limit the progression of malignant tumor. This review discusses the role of cadherins in selected signaling mechanisms involved in tumor growth. The clinical importance of cadherin will be discussed in cases of human and animal cancers.

Pathways of Gastric Carcinogenesis, Helicobacter pylori Virulence and Interactions with Antioxidant Systems, Vitamin C and Phytochemicals

Helicobacter pylori is a class one carcinogen which causes chronic atrophic gastritis, gastric intestinal metaplasia, dysplasia and adenocarcinoma. The mechanisms by which H. pylori interacts with other risk and protective factors, particularly vitamin C in gastric carcinogenesis are complex. Gastric carcinogenesis includes metabolic, environmental, epigenetic, genomic, infective, inflammatory and oncogenic pathways. The molecular classification of gastric cancer subtypes has revolutionized the understanding of gastric carcinogenesis. This includes the tumour microenvironment, germline mutations, and the role of Helicobacter pylori bacteria, Epstein Barr virus and epigenetics in somatic mutations. There is evidence that ascorbic acid, phytochemicals and endogenous antioxidant systems can modify the risk of gastric cancer. Gastric juice ascorbate levels depend on dietary intake of ascorbic acid but can also be decreased by H. pylori infection, H. pylori CagA secretion, tobacco smoking, achlorhydria and chronic atrophic gastritis. Ascorbic acid may be protective against gastric cancer by its antioxidant effect in gastric cytoprotection, regenerating active vitamin E and glutathione, inhibiting endogenous N-nitrosation, reducing toxic effects of ingested nitrosodimethylamines and heterocyclic amines, and preventing H. pylori infection. The effectiveness of such cytoprotection is related to H. pylori strain virulence, particularly CagA expression. The role of vitamin C in epigenetic reprogramming in gastric cancer is still evolving. Other factors in conjunction with vitamin C also play a role in gastric carcinogenesis. Eradication of H. pylori may lead to recovery of vitamin C secretion by gastric epithelium and enable regression of premalignant gastric lesions, thereby interrupting the Correa cascade of gastric carcinogenesis.

Hypoxia induced exosomal circRNA promotes metastasis of Colorectal Cancer via targeting GEF-H1/RhoA axis

Hypoxia is one of the important properties of solid tumor. However, oxygen supply within tumors is generally heterogeneous according to the distance from the nearest blood vessel. The discrepancy of metastatic potential exists between hypoxic cancer cells and relatively normoxic cancer cells. But the molecular mechanism remains poorly understood. Methods: Differential expression of circRNAs in plasma exosomes of CRC patients and normal subjects was performed by screening. Exosomes were isolated by ultra-centrifugation and RNA expressions were determined by RT-qPCR. The migratory capacity of cells was performed by high intension imaging, wound healing assay and transwell chamber migration assay. Results: Circ-133 is enriched in the plasma exosomes of CRC patients and increased with the disease progression. Exosomal circ-133 derived from hypoxic cells delivered into normoxic cells and promoted cancer metastasis by acting on miR-133a/GEF-H1/RhoA axis. Meanwhile, animal experiments revealed that knockdown of circ-133 can inhibit tumor metastasis. Circ-133 is expected to be a new biomarker for monitoring tumor progression and might be a novel therapeutic target. Conclusions: Hypoxia-derived exosomal circ-133 transported into normaxic cancer cells and promoted cell migration via miR-133a/GEF-H1/RhoA axis. This study reveals a potential mechanism for that the intra-tumor heterogeneity of oxygen promote cancer progression.

Turmeric Is Therapeutic in Vivo on Patient-Derived Colorectal Cancer Xenografts: Inhibition of Growth, Metastasis, and Tumor Recurrence

Colorectal cancer is the third most frequently diagnosed cancer worldwide. Clinically, chemotherapeutic agents such as FOLFOX are the mainstay of colorectal cancer treatment. However, the side effects including toxicity of FOLFOX stimulated the enthusiasm for developing adjuvants, which exhibit better safety profile. Turmeric extract (TE), which has been previously shown to suppress the growth of human and murine colon xenografts, was further demonstrated here for its inhibitory effects on colon cancer patient-derived xenografts (PDX). PDX models were successfully established from tissues of colon cancer patients and the PDX preserved the heterogeneous architecture through passages. NOD/SCID mice bearing PDX were treated either with TE or FOLFOX and differential responses toward these treatments were observed. The growth of PDX, metastasis and tumor recurrence in PDX-bearing mice were suppressed after TE treatments with 60% anti-tumor response rate and 83.3% anti-metastasis rate. Mechanistic studies showed that TE reduced tumor cell proliferation, induced cell apoptosis, inhibited metastasis via modulating multiple targets, such as molecules involved in Wnt and Src pathways, EMT and EGFR-related pathways. Nevertheless, FOLFOX treatments inhibited the PDX growth with sharp decreases of mice body weight and only mild anti-metastasis activities were observed. Furthermore, in order to have a better understanding of the underlying mechanisms, network pharmacology was utilized to predict potential targets and mechanism. In conclusion, the present study demonstrated for the first time that oral TE treatment was effective to suppress the growth of colon PDX and the recurrence of colon tumors in mice. The findings obtained from this clinically relevant PDX model would certainly provide valuable information for the potential clinical use of TE in colorectal cancer patients. The application of PDX model was well illustrated here as a good platform to verify the efficacy of multi-targeted herbal extracts.

UNC13C Suppress Tumor Progression via Inhibiting EMT Pathway and Improves Survival in Oral Squamous Cell Carcinoma

Potential function of UNC13C in variety of cancers including, oral squamous cell carcinoma (OSCC) remains obscure. In the present study, immunohistochemical staining in tissue microarrays containing 268 OSCC samples showed that UNC13C protein levels were inversely correlated with AJCC Stage III and IV (P = 0.002) and death (P = 0.0134). Patients with lower UNC13C expression had a significantly shorter survival (P = 0.0231) than those with higher UNC13C expression. We also identified decreased overall UNC13C expression in oral cancer cell lines. In addition, our functional analysis of UNC13C shows that overexpression of UNC13C inhibited migration and invasion capacities of SCC-9 and SAS cells compared with the empty plasmid transfected cells. Further experiments suggested that transcription factors (Slug, Snail, Twist, and ZEB1) and mesenchymal marker (Vimentin) were down regulated and Tight Junction Protein (Claudin1) was up regulated after UNC13C overexpression in SCC9 and SAS cells. The novel role of UNC13C is revealed for the first time in OSCC. In summary, these results suggest that UNC13C as a novel tumor suppressor and an essential regulator of EMT signaling pathway during OSCC progression, and thus it could be used as a target for preventing oral cancer metastasis.

Recent advances of therapeutic targets based on the molecular signature in breast cancer: genetic mutations and implications for current treatment paradigms

Breast cancer is the most common malignancy in women all over the world. Genetic background of women contributes to her risk of having breast cancer. Certain inherited DNA mutations can dramatically increase the risk of developing certain cancers and are responsible for many of the cancers that run in some families. Regarding the widespread multigene panels, whole exome sequencing is capable of providing the evaluation of genetic function mutations for development novel strategy in clinical trials. Targeting the mutant proteins involved in breast cancer can be an effective therapeutic approach for developing novel drugs. This systematic review discusses gene mutations linked to breast cancer, focusing on signaling pathways that are being targeted with investigational therapeutic strategies, where clinical trials could be potentially initiated in the future are being highlighted.

Effect of Weightlessness on the 3D Structure Formation and Physiologic Function of Human Cancer Cells

With the rapid development of modern medical technology and the deterioration of living environments, cancer, the most important disease that threatens human health, has attracted increasing concerns. Although remarkable achievements have been made in tumor research during the past several decades, a series of problems such as tumor metastasis and drug resistance still need to be solved. Recently, relevant physiological changes during space exploration have attracted much attention. Thus, space exploration might provide some inspiration for cancer research. Using on ground different methods in order to simulate microgravity, structure and function of cancer cells undergo many unique changes, such as cell aggregation to form 3D spheroids, cell-cycle inhibition, and changes in migration ability and apoptosis. Although numerous better experiments have been conducted on this subject, the results are not consistent. The reason might be that different methods for simulation have been used, including clinostats, random positioning machine (RPM) and rotating wall vessel (RWV) and so on. Therefore, we review the relevant research and try to explain novel mechanisms underlying tumor cell changes under weightlessness.

Clinical significance of epithelial-mesenchymal transition-related molecules in lung adenocarcinoma

Background

Epithelial-mesenchymal transition (emt) refers to the biologic process in which epithelial cells are transformed into interstitial phenotypes by specific pathways. This transition plays an important biologic role in the process by which epithelium-derived malignant tumour cells acquire the ability to migrate and invade. We explored the relationship between emt-associated molecules and patient-related clinical factors to determine whether any clinical characteristics could be used as biomarkers for emt-related protein alterations in lung cancer-especially lung adenocarcinoma.

Methods

Tumour specimens were collected from 80 patients with lung adenocarcinoma who underwent surgery or lung biopsy, with 4 patients being evaluated a 2nd time after re-biopsy. Expression of emt-related proteins, including E-cadherin and vimentin, was evaluated by immunohistochemistry. We analyzed the relationship between clinicopathologic characteristics and expression level of the emt markers.

Results

Positive expression of E-cadherin was observed in 63 patients (79%), and vimentin, in 46 patients (57.5%). No significant relationships between E-cadherin or vimentin expression and smoking history, sex, age, driving gene mutations, or cell differentiation were identified. A significant correlation was observed between vimentin expression and pathologic stage. Of the 4 patients who were evaluated a 2nd time after re-biopsy, 3 showed the same emt-related protein expression status as in the first analysis. In the remaining patient, E-cadherin had changed completely.

Conclusions

Clinicopathologic factors in cancer patients did not help to diagnose emt status in lung adenocarcinoma; however, TNM stage might be associated with vimentin expression.

Long non-coding RNA ZEB1-AS1 regulates miR-200b/FSCN1 signaling and enhances migration and invasion induced by TGF-β1 in bladder cancer cells

Background

The effect of competing endogenous RNA (ceRNA) can regulate gene expression by competitively binding microRNAs. Fascin-1 (FSCN1) plays an important role in the regulation of cellular migration and invasion during tumor progression, but how its regulatory mechanism works through the ceRNA effect is still unclear in bladder cancer (BLCA).

Methods

The role of fascin-1, miR-200b, and ZEB1-AS1 in BLCA was investigated in vitro and in vivo. The interaction between fascin-1, miR-200b, and ZEB1-AS1 was identified using bioinformatics analysis, luciferase activity assays, RNA-binding protein immunoprecipitation (RIP), quantitative PCR, and western blotting. Loss (or gain)-of-function experiments were performed to investigate the biological roles of miR-200b and ZEB1-AS1 on migration, invasion, proliferation, cell apoptosis, and cell cycle.

Results

ZEB1-AS1 functions as a competing endogenous RNA in BLCA to regulate the expression of fascin-1 through miR-200b. Moreover, the oncogenic long non-coding RNA ZEB1-AS1 was highly expressed in BLCA and positively correlated with high tumor grade, high TNM stage, and reduced survival of patients with BLCA. Moreover, ZEB1-AS1 downregulated the expression of miR-200b, promoted migration, invasion, and proliferation, and inhibited apoptosis in BLCA. Furthermore, we found TGF-β1 induced migration and invasion in BLCA by regulating the ZEB1-AS1/miR-200b/FSCN1 axis.

Conclusion

The observations in this study identify an important regulatory mechanism of fascin-1 in BLCA, and the TGF-β1/ZEB1-AS1/miR-200b/FSCN1 axis may serve as a potential target for cancer therapeutic purposes.

Electronic supplementary material

The online version of this article (10.1186/s13046-019-1102-6) contains supplementary material, which is available to authorized users.

Bone marrow mesenchymal stromal cells attenuate silica-induced pulmonary fibrosis potentially by attenuating Wnt/β-catenin signaling in rats

BACKGROUND

Pulmonary fibrosis induced by silica dust is an irreversible, chronic, and fibroproliferative lung disease with no effective treatment at present. Previous studies have shown that early intervention with bone marrow mesenchymal stem/stromal cells (BMSCs) has positive effect on anti-pulmonary fibrosis caused by silica dust. However, early intervention using BMSCs is not practical, and the therapeutic effects of BMSCs advanced intervention on pulmonary fibrosis have rarely been reported. In this study, we investigated the effects of advanced transplantation (on the 28th day after exposure to silica suspension) of BMSCs on an established rat model of pulmonary fibrosis.

METHODS

Sprague Dawley (SD) rats were randomly divided into four groups including (1) control group (n = 6) which were normally fed, (2) silica model group (n = 6) which were exposed to silica suspension (1 mL of 50 mg/mL/rat), (3) BMSC transplantation group (n = 6) which received 1 mL BMSC suspension (2 × 10⁶ cells/mL) by tail vein injection on the 28th day after exposure to silica suspension, and (4) BMSC-CM (conditioned medium) transplantation group (n = 6) which received CM from the same cell number by tail vein injection on the 28th day after exposure to silica suspension. On the 56th day after exposure to silica suspension, we used computed tomography (CT), hematoxylin and eosin (H&E), and Masson's trichrome staining to evaluate the changes in lung tissue. We examined the expression of epithelial-mesenchymal transition (EMT) and Wnt/β-catenin pathway-related proteins in lung tissue using immunohistochemistry and western blotting.

RESULTS

Successful construction of a pulmonary fibrosis model was confirmed by H&E and Masson's trichrome staining on the 28th day after exposure to silica suspension. On the 56th day after exposure, pulmonary CT examination showed a relieving effect of BMSCs on silica-induced pulmonary fibrosis which was confirmed by H&E and Masson's trichrome staining. Treatment of BMSCs increased the expression of epithelial marker proteins including E-cadherin (E-cad) and cytokeratin19 (CK19) and reduced the expression of fibrosis marker proteins including Vimentin (Vim) and α-Smooth actin (α-SMA) after exposure to silica suspension. Furthermore, we found that Wnt/β-catenin signaling pathway is abnormally activated in silica-induced pulmonary fibrosis, and exogenous transplantation of BMSCs may attenuate their expression.

CONCLUSIONS

BMSC transplantation inhibits the EMT to alleviate silica-induced pulmonary fibrosis in rats and the anti-fibrotic effect potentially by attenuating Wnt/β-catenin signaling. ᅟ: ᅟ.

The epigenetic factor KDM2B regulates cell adhesion, small rho GTPases, actin cytoskeleton and migration in prostate cancer cells

The histone demethylase KDM2B is an epigenetic factor with oncogenic properties that is regulated by the basic fibroblasts growth factor (FGF-2). It has recently been shown that KDM2B co-operates with Polycomb Group proteins to promote cell migration and angiogenesis in tumors. In the present study we addressed the role of KDM2B in regulating actin cytoskeleton signaling, cell-cell adhesion and migration of prostate tumor cells. We report here that KDM2B is functionally expressed in DU-145 prostate cancer cells, activated by FGF-2 and regulates EZH2. KDM2B knockdown induced potent up-regulation of gene transcription and protein expression of the epithelial markers E-cadherin and ZO-1, while KDM2B overexpression down-regulated the levels of both markers, suggesting control of cell adhesion by KDM2B. RhoA and RhoB protein expression and activity were diminished upon KDM2B-knockdown and upregulated in KDM2B-overexpressing cell clones. In accordance, actin reorganization with formation of stress fibers became evident in KDM2B-overexpressing cells and abolished in the presence of the Rho inhibitor C3 transferase. DU-145 cell migration was significantly enhanced in KDM2B overexpressing cells and abolished in C3-pretreated cells. Conversely, the retardation of cell migration observed in KDM2B knockdown cells was enhanced in C3-pretreated cells. These results establish a clear functional link between the epigenetic factor KDM2B and the regulation of cell adhesion and Rho-GTPases signaling that controls actin reorganization and cell migration.

Decoding colorectal cancer epigenomics

Colorectal cancer (CRC) is very heterogeneous and presents different types of epigenetic alterations including DNA methylation, histone modifications and microRNAs. These changes are considered as characteristics of various observed clinical phenotypes. Undoubtedly, the discovery of epigenetic pathways with novel epigenetic-related mechanisms constitutes a promising advance in cancer biomarker discovery. In this review, we provide an evidence-based discussing of the current understanding of CRC epigenomics and its role in initiation, epithelial-to-mesenchymal transition and metastasis. We also discuss the recent findings regarding the potential clinical perspectives of these alterations as potent biomarkers for CRC diagnosis, prognosis, and therapy in the era of liquid biopsy.

Regulatory activity based risk model identifies survival of stage II and III colorectal carcinoma

Clinical and pathological indicators are inadequate for prognosis of stage II and III colorectal carcinoma (CRC). In this study, we utilized the activity of regulatory factors, univariate Cox regression and random forest for variable selection and developed a multivariate Cox model to predict the overall survival of Stage II/III colorectal carcinoma in GSE39582 datasets (469 samples). Patients in low-risk group showed a significant longer overall survival and recurrence-free survival time than those in high-risk group. This finding was further validated in five other independent datasets (GSE14333, GSE17536, GSE17537, GSE33113, and GSE37892). Besides, associations between clinicopathological information and risk score were analyzed. A nomogram including risk score was plotted to facilitate the utilization of risk score. The risk score model is also demonstrated to be effective on predicting both overall and recurrence-free survival of chemotherapy received patients. After performing Gene Set Enrichment Analysis (GSEA) between high and low risk groups, we found that several cell-cell interaction KEGG pathways were identified. Funnel plot results showed that there was no publication bias in these datasets. In summary, by utilizing the regulatory activity in stage II and III colorectal carcinoma, the risk score successfully predicts the survival of 1021 stage II/III CRC patients in six independent datasets.

Action and function of Wnt/β-catenin signaling in the progression from chronic hepatitis C to hepatocellular carcinoma

Hepatitis C virus (HCV) infection is one of the leading causes of hepatocellular carcinoma (HCC) worldwide but the mechanistic basis as to how chronic HCV infection furthers the HCC process remains only poorly understood. Accumulating evidence indicates that HCV core and nonstructural proteins provoke activation of the Wnt/β-catenin signaling pathway, and the evidence supporting a role of Wnt/β-catenin signaling in the onset and progression of HCC is compelling. Convincing molecular explanations as to how expression of viral effectors translates into increased activity of the Wnt/β-catenin signaling machinery are still largely lacking, hampering the design of rational strategies aimed at preventing HCC. Furthermore, how such increased signaling is especially associated with HCC oncogenesis in the context of HCV infection remains obscure as well. Here we review the body of contemporary biomedical knowledge on the role of the Wnt/β-catenin pathway in the progression from chronic hepatitis C to cirrhosis and HCC and explore potential hypotheses as to the mechanisms involved.

Effect of Annexin A1 gene on the proliferation and invasion of esophageal squamous cell carcinoma cells and its regulatory mechanisms

The aim of this study was to examine the effect of Annexin A1 (ANXA1) on the proliferation, migration and invasion of esophageal squamous cell carcinoma (ESCC) cells and its possible mechanisms of action. After constructing the ANXA1 overexpression plasmid, we transfected this plasmid and/or microRNA (miRNA)‑196a mimic into ESCC cells (Eca109 cell line). Methyl thiazolyl tetrazolium (MTT) assay and Transwell chamber assay were performed to determine cell proliferation, migration and invasion, respectively. Western blot analysis was used to examine the protein expression levels of ANXA1, Snail and E-cadherin. RT-PCR was used to detect the expression of miRNA-196a. Our results revealed that ANXA1 expression was upregulated in the cells transfected with the ANXA1 overexpression plasmid, and cell proliferation, migration and invasion were significantly increased (p=0.004, p<0.001 and p=0.011, respectively). In the cells transfected with the miRNA‑196a mimic, miRNA‑196a expression was significantly upregulated (p<0.001). However, miRNA-196a expression was downregulated in the cells transfected with the ANXA1 overexpression plasmid. In addition, in the cells transfected with the miRNA‑196a mimic, cell proliferation, migration and invasion were significantly decreased (p=0.027, p=0.009 and p=0.021, respectively). In the cells transfected with the ANXA1 overexpression plasmid, the expression of Snail was upregulated and that of E-cadherin was downregulated. However, the opposite was observed in the cells transfected with the miRNA‑196a mimic. Our findings thus demonstrate that ANXA1 promotes the proliferation of Eca109 cells, and increases the expression of Snail, whereas it inhibits that of E-cadherin, thus enhancing the migration and invasion of ESCC cells. miRNA-196a negatively regulates the expression of ANXA1, thereby inhibiting the proliferation, invasion and metastasis of ESCC cells.

Inhibitory effect of α-solanine on esophageal carcinoma in vitro

α-solanine, a bioactive component and one of the major steroidal glycoalkaloids in potatoes, has been observed to inhibit growth and induce apoptosis in cancer cells. However, the antitumor efficacy of α-solanine on esophageal carcinoma has yet to be fully elucidated. In the present study, the antitumor efficacy of α-solanine against human esophageal carcinoma cells was investigated. It was determined that α-solanine inhibited the growth and proliferation of human esophageal EC9706 and Eca109 cancer cells in a dose-dependent manner, as well as the cell migration and invasion. In addition, the apoptotic rate was increased in the cancer cells treated with α-solanine in a dose-dependent manner, compared with that of the control group (P<0.05). The expression levels of tumor metastasis-related proteins, including matrix metalloproteinase (MMP)-2 and MMP-9, were reduced in the cells treated with α-solanine, as compared with the control group. Conversely, significantly higher expression levels of E-cadherin were detected in the α-solanine-treated groups, as compared with the control group (P<0.05). Therefore, the current results provide a novel insight into the anti-tumor mechanism of α-solanine, and suggest that α-solanine is a potential agent for the prevention and treatment of esophageal carcinoma.

TGF-β1 promotes the migration and invasion of bladder carcinoma cells by increasing fascin1 expression

Transforming growth factor-β1 (TGF-β1) is a multifunctional cytokine that is reported to regulate cellular motility and invasive capability during tumor progression. Fascin1, an actin-bundling protein, increases cell motility, migration and adhesion. To investigate the function of TGF-β1 and test whether fascin1 is an important mediator of the tumor response to TGF-β1 in bladder carcinoma cells, real-time RT-PCR and western blot analysis were used to test changes in fascin1 expression after TGF-β1 (10 ng/ml) treatment in T24 and BIU87 cells. Small interfering RNA (siRNA) technique was performed to silence fascin1. Cell viability and biological behavior changes were evaluated by cell growth (MTT), wound-healing and Matrigel invasion assays. In the present study, we found that the mRNA and protein levels of fascin1 in the T24 and BIU87 cells were significantly increased after 10 ng/ml TGF-β1 treatment (p<0.05). The proliferation of T24 cells (p=0.005) was also significantly increased, while no significant change was observed in BIU87 cells (p=0.318). In addition, the migratory and invasive potential of the two cell lines were promoted. Furthermore, we successfully silenced fascin1, and observed that fascin1 siRNA significantly attenuated the migration and invasiveness induced by TGF-β1. The findings suggested that TGF-β1 can promote invasion and migration of T24 and BIU87 bladder carcinoma cells, and the increase in fascin1 expression may be the key point of this impact of TGF-β1.

Modulation of E-cadherin expression promotes migration ability of esophageal cancer cells

Losing the E-cadherin plays an important role in the metastasis of cancer. The regulation of the expression of E-cadherin is unclear. Circadian rhythm alteration is associated with the pathogenesis of a number of cancers. This study aims to investigate the role of one of the circadian proteins, period-2 (Per2) in repressing the expression of E-cadherin in esophageal cancer (esophageal cancer). We observed that the levels of circadian protein Per2 were significantly increased and E-cadherin was significantly decreased in the tissue of human esophageal cancer with metastasis as compared with non-metastatic esophageal cancer. Overexpression of Per2 in the esophageal cancer cells markedly repressed the expression of E-cadherin. The pHDAC1 was detected in human esophageal cancer with metastasis, which was much less in the esophageal cancer tissue without metastasis. Overexpression of Per2 increased the levels of pHDAC1 as well as the E-cadherin repressors at the E-cadherin promoter locus. Overexpression of Per2 markedly increased the migratory capacity of esophageal cancer cells, which was abolished by the inhibition of HDAC1. We conclude that Per-2 plays an important role in the esophageal cancer cell metastasis, which may be a novel therapeutic target for the treatment of esophageal cancer.

Mathematical Modelling of Molecular Pathways Enabling Tumour Cell Invasion and Migration

Understanding the etiology of metastasis is very important in clinical perspective, since it is estimated that metastasis accounts for 90% of cancer patient mortality. Metastasis results from a sequence of multiple steps including invasion and migration. The early stages of metastasis are tightly controlled in normal cells and can be drastically affected by malignant mutations; therefore, they might constitute the principal determinants of the overall metastatic rate even if the later stages take long to occur. To elucidate the role of individual mutations or their combinations affecting the metastatic development, a logical model has been constructed that recapitulates published experimental results of known gene perturbations on local invasion and migration processes, and predict the effect of not yet experimentally assessed mutations. The model has been validated using experimental data on transcriptome dynamics following TGF-β-dependent induction of Epithelial to Mesenchymal Transition in lung cancer cell lines. A method to associate gene expression profiles with different stable state solutions of the logical model has been developed for that purpose. In addition, we have systematically predicted alleviating (masking) and synergistic pairwise genetic interactions between the genes composing the model with respect to the probability of acquiring the metastatic phenotype. We focused on several unexpected synergistic genetic interactions leading to theoretically very high metastasis probability. Among them, the synergistic combination of Notch overexpression and p53 deletion shows one of the strongest effects, which is in agreement with a recent published experiment in a mouse model of gut cancer. The mathematical model can recapitulate experimental mutations in both cell line and mouse models. Furthermore, the model predicts new gene perturbations that affect the early steps of metastasis underlying potential intervention points for innovative therapeutic strategies in oncology.

OTUB1 promotes metastasis and serves as a marker of poor prognosis in colorectal cancer

Background

OTUB1 (OTU deubiquitinase, ubiquitin aldehyde binding 1) is a deubiquitinating enzyme (DUB) that belongs to the OTU (ovarian tumor) superfamily. The aim of this study was to clarify the role of OTUB1 in colorectal cancer (CRC) and to identify the mechanism underlying its function.

Methods

Two hundred and sixty CRC samples were subjected to association analysis of OTUB1 expression and clinicopathological variables using immunohistochemical (IHC) staining. Overexpression of OTUB1 was achieved in SW480 and DLD-1 cells, and downregulation of OTUB1 was employed in SW620 cells. Then, migration and invasion assays were performed, and markers of the epithelial-mesenchymal transition (EMT) were analyzed. In addition, hepatic metastasis models in mice were used to validate the function of OTUB1 in vivo.

Results

OTUB1 was overexpressed in CRC tissues, and the expression level of OTUB1 was associated with metastasis. A high expression level of OTUB1 was also associated with poor survival, and OTUB1 served as an independent prognostic factor in multivariate analysis. OTUB1 also promoted the metastasis of CRC cell lines in vitro and in vivo by regulating EMT.

Conclusions

OTUB1 promotes CRC metastasis by facilitating EMT and acts as a potential distant metastasis marker and prognostic factor in CRC. Targeting OTUB1 may be helpful for the treatment of CRC.

Electronic supplementary material

The online version of this article (doi:10.1186/1476-4598-13-258) contains supplementary material, which is available to authorized users.

[In situ analyses of molecular mechanisms of colorectal carcinogenesis]

The main signaling pathways of colorectal carcinogenesis encompass the classical adenoma-carcinoma sequence and the serrated route. In the classical adenoma-carcinoma sequence there are initially frequent mutations of the APC gene which lead to an activation of the WNT signaling pathway. When the WNT signaling pathway is activated β-catenin mediates the transcription of diverse factors which cause migration, invasion and proliferation of cells. Although APC mutations occur in all tumor cells, a heterogeneous distribution pattern of β-catenin is found in tumors and β-catenin also represents an important prognostic marker. A similar picture is found for γ-catenin which is expressed independently from β-catenin. Clearly more homogeneous is the expression of TCF4 and LEF1 which are the main binding partners of β-catenin and γ-catenin and are likewise important prognostic markers. The TRAIL signaling pathway is therapeutically interesting and within this pathway loss of the main receptors TRAIL-R1 and TRAIL-R2 is frequently found. Furthermore, the membranous localization of both factors correlates with a better overall survival. These results might be therapeutically relevant with respect to therapy with recombinant TRAIL molecules binding to TRAIL-R1 and TRAIL-R2. In the serrated route oncogen-induced senescence caused by mutations of the KRAS and BRAF oncogenes initially plays an important role. This senescence blockade is overcome by hypermethylation of the p16(INK4a) promoter and leads to the development of invasive tumors. The SIRT1 and c-Myc genes also contribute to progression of lesions in the serrated route and are activated through the RAS/RAF/MAPK-kinase signaling pathway as well as the WNT/β-catenin signaling pathway.

Btbd7 contributes to reduced E-cadherin expression and predicts poor prognosis in non-small cell lung cancer

BACKGROUND

Disorders of cell adhesion are critical steps in cancer progression in which varieties of markers including cadherins are involved in.Btbd7 was found to inhibit E-cadherin expression in MDCK cells and play important roles during branching morphogenesis of embryonic salivary glands and lungs. However its function in malignant tumors is largely unknown. The aim of this study is to investigate the clinicopathological significance and possible function of Btbd7 in non-small cell lung cancer.

METHODS

Immunohistochemistry and Western blotting were used to investigate Btbd7 expression in non-small cell lung cancer and lung tissues. The clinicopathological association and the overall survival was analyzed. In vitro experiments were performed using siRNA to investigate the function of Btbd7 in lung cancer cells.

RESULTS

Btbd7 expression was elevated in non-small cell lung cancer tissues compared to normal lung tissues. Increased Btbd7 expression was significantly associated with lymph node metastasis, reduced E-cadherin expression and patients' poor clinical outcome. Downregulation of Btbd7 expression in lung cancer cells by siRNA significantly inhibits cancer cell invasion and effectively restores E-cadherin expression in cancer cell membrane.

CONCLUSIONS

Btbd7 contributes to reduced expression of E-cadherin and may be a promising cancer marker in non-small cell lung cancer.

Normal fibroblasts induce E-cadherin loss and increase lymph node metastasis in gastric cancer

Background

A tumor is considered a heterogeneous complex in a three-dimensional environment that is flush with pathophysiological and biomechanical signals. Cell-stroma interactions guide the development and generation of tumors. Here, we evaluate the contributions of normal fibroblasts to gastric cancer.

Methodology/Principal Findings

By coculturing normal fibroblasts in monolayers of BGC-823 gastric cancer cells, tumor cells sporadically developed short, spindle-like morphological characteristics and demonstrated enhanced proliferation and invasive potential. Furthermore, the transformed tumor cells demonstrated decreased tumor formation and increased lymphomatic and intestinal metastatic potential. Non-transformed BGC-823 cells, in contrast, demonstrated primary tumor formation and delayed intestinal and lymph node invasion. We also observed E-cadherin loss and the upregulation of vimentin expression in the transformed tumor cells, which suggested that the increase in metastasis was induced by epithelial-to-mesenchymal transition.

Conclusion

Collectively, our data indicated that normal fibroblasts sufficiently induce epithelial-to-mesenchymal transition in cancer cells, thereby leading to metastasis.

Carcinoembryonic antigen promotes colorectal cancer progression by targeting adherens junction complexes

Oncomarkers play important roles in the detection and management of human malignancies. Carcinoembryonic antigen (CEA, CEACAM5) and epithelial cadherin (E-cadherin) are considered as independent tumor markers in monitoring metastatic colorectal cancer. They are both expressed by cancer cells and can be detected in the blood serum. We investigated the effect of CEA production by MIP101 colorectal carcinoma cell lines on E-cadherin adherens junction (AJ) protein complexes. No direct interaction between E-cadherin and CEA was detected; however, the functional relationships between E-cadherin and its AJ partners: α-, β- and p120 catenins were impaired. We discovered a novel interaction between CEA and beta-catenin protein in the CEA producing cells. It is shown in the current study that CEA overexpression alters the splicing of p120 catenin and triggers the release of soluble E-cadherin. The influence of CEA production by colorectal cancer cells on the function of E-cadherin junction complexes may explain the link between the elevated levels of CEA and the increase in soluble E-cadherin during the progression of colorectal cancer.

Hepatitis C virus represses E-cadherin expression via DNA methylation to induce epithelial to mesenchymal transition in human hepatocytes

Hepatitis C virus (HCV) core protein is known to induce promoter hypermethylation of tumor suppressor genes including E-cadherin to repress their expression when overexpressed in human hepatocytes; however, its actual role during HCV infection is still unknown. Here, we report that infection with HCV derived from pJFH-1 replicon system that mimics natural infection elevates protein levels of DNA methyltransferase 1 and 3b to enhance DNMT activity in human hepatocytes. As a consequence, HCV induced promoter hypermethylation of E-cadherin, resulting in repression of its expression. In addition down-regulation of E-cadherin by HCV led to epithelial-mesenchymal transition that is known to be a critical event during the late stage of tumorigenesis.

MiR-200a regulates epithelial to mesenchymal transition-related gene expression and determines prognosis in colorectal cancer patients

Background:

MicroRNAs (miRNAs) regulate the biological properties of colorectal cancer (CRC) cells and might serve as potential prognostic factors and therapeutic targets. In this study, we therefore globally profiled miRNAs associated with E-cadherin expression in CRC cells in an attempt to identify miRNAs that are associated with aggressive clinical course in CRC patients.

Methods:

Two CRC cell lines (Caco-2 and HRT-18) with different E-cadherin expression pattern were profiled for differences in abundance for more than 1000 human miRNAs using microarray technology. One of the most differentially expressed miRNAs, miR-200a was evaluated for its prognostic role in a cohort of 111 patients and independently validated in 217 patients of the Cancer Genome Atlas data set. To further characterise the biological role of miR-200a expression in CRC, in vitro miR-200a inhibition and overexpression were performed and the effects on cellular growth, apoptosis and epithelial–mesenchymal transition (EMT)-related gene expression were explored.

Results:

In situ hybridisation specifically localised miR-200a in CRC cells. In both cohorts, a low miR-200a expression was associated with poor survival (P<0.05). Multivariate Cox regression analysis identified low levels of miR-200a expression as an independent prognostic factor with respect to cancer-specific survival (HR=2.04, CI=1.28–3.25, P<0.002). Gain and loss of function assays for miR-200a in vitro led to a significantly differential and converse expression of EMT-related genes (P<0.001.) A low expression of miR-200a was also observed in cancer stem cell-enriched spheroid growth conditions (P<0.05).

Conclusions:

In conclusion, our data suggest that low miR-200a expression is associated with poor prognosis in CRC patients. MiR-200a has a regulatory effect on EMT and is associated with cancer stem cell properties in CRC.

Meta-analysis and gene set analysis of archived microarrays suggest implication of the spliceosome in metastatic and hypoxic phenotypes

We propose to make use of the wealth of underused DNA chip data available in public repositories to study the molecular mechanisms behind the adaptation of cancer cells to hypoxic conditions leading to the metastatic phenotype. We have developed new bioinformatics tools and adapted others to identify with maximum sensitivity those genes which are expressed differentially across several experiments. The comparison of two analytical approaches, based on either Over Representation Analysis or Functional Class Scoring, by a meta-analysis-based approach, led to the retrieval of known information about the biological situation - thus validating the model - but also more importantly to the discovery of the previously unknown implication of the spliceosome, the cellular machinery responsible for mRNA splicing, in the development of metastasis.

Antitumor efficacy of α-solanine against pancreatic cancer in vitro and in vivo

α-solanine, a steroidal glycoalkaloid in potato, was found to have proliferation-inhibiting and apoptosis-promoting effect on multiple cancer cells, such as clone, liver, melanoma cancer cells. However, the antitumor efficacy of α-solanine on pancreatic cancer has not been fully evaluated. In this study, we inquired into the anti-carcinogenic effect of α-solanine against human pancreatic cancer cells. In the present study, we investigated the anti-carcinogenic effect of α-solanine against human pancreatic cancer cells. In vitro, α-solanine inhibited proliferation of PANC-1, sw1990, MIA PaCa-2 cells in a dose-dependent manner, as well as cell migration and invasion with atoxic doses. The expression of MMP-2/9, extracellular inducer of matrix metalloproteinase (EMMPRIN), CD44, eNOS and E-cadherin were suppressed by α-solanine in PANC-1 cells. Moreover, significantly decreased vascular endothelial growth factor (VEGF) expression and tube formation of endothelial cells were discerned following α-solanine treatment. Suppressed phosphorylation of Akt, mTOR, and Stat3, and strengthen phosphorylation of β-catenin was found, along with markedly decreased tran-nuclear of NF-κB, β-catenin and TCF-1. Following the administration of α-solanine (6 µg/g for 2 weeks) in xenograft model, tumor volume and weight were decreased by 61% and 43% (p<0.05) respectively, showing decreased MMP-2/9, PCNA and VEGF expression. In conclusion, α-solanine showed beneficial effects on pancreatic cancer in vitro and in vivo, which may via suppressing the pathway proliferation, angiogenesis and metastasis.

STRIPAK complexes: structure, biological function, and involvement in human diseases

The mammalian striatin family consists of three proteins, striatin, S/G2 nuclear autoantigen, and zinedin. Striatin family members have no intrinsic catalytic activity, but rather function as scaffolding proteins. Remarkably, they organize multiple diverse, large signaling complexes that participate in a variety of cellular processes. Moreover, they appear to be regulatory/targeting subunits for the major eukaryotic serine/threonine protein phosphatase 2A. In addition, striatin family members associate with germinal center kinase III kinases as well as other novel components, earning these assemblies the name striatin-interacting phosphatase and kinase (STRIPAK) complexes. Recently, there has been a great increase in functional and mechanistic studies aimed at identifying and understanding the roles of STRIPAK and STRIPAK-like complexes in cellular processes of multiple organisms. These studies have identified novel STRIPAK and STRIPAK-like complexes and have explored their roles in specific signaling pathways. Together, the results of these studies have sparked increased interest in striatin family complexes because they have revealed roles in signaling, cell cycle control, apoptosis, vesicular trafficking, Golgi assembly, cell polarity, cell migration, neural and vascular development, and cardiac function. Moreover, STRIPAK complexes have been connected to clinical conditions, including cardiac disease, diabetes, autism, and cerebral cavernous malformation. In this review, we discuss the expression, localization, and protein domain structure of striatin family members. Then we consider the diverse complexes these proteins and their homologs form in various organisms, emphasizing what is known regarding function and regulation. Finally, we explore possible roles of striatin family complexes in disease, especially cerebral cavernous malformation.

CRH suppressed TGFβ1-induced Epithelial-Mesenchymal Transition via induction of E-cadherin in breast cancer cells

Since its discovery in biopsies from breast cancer patients, the effect of corticotropin-releasing hormone (CRH) on carcinoma progression is still unclear. Transforming growth factorβ1 (TGFβ1) promotes Epithelial-Mesenchymal Transition (EMT) and induces Snail1 and Twist1 expressions. Loss of epithelial cadherin (E-cadherin) mainly repressed by Snail1 and Twist1, has been considered as hallmark of Epithelial-Mesenchymal Transition (EMT). Two breast cancer cell lines, MCF-7 and MDA-MB-231 were used to investigate the effect of CRH on TGFβ1-induced EMT by transwell chamber. And HEK293 cells were transiently transfected with CRHR1 or CRHR2 to explore the definite effects of CRH receptor. We reported that CRH inhibited migration of human breast cancer cells through downregulation of Snail1 and Twist1, and subsequent upregulation of E-cadherin. CRH inhibited TGFβ1-mediated migration of MCF-7 via both CRHR1 and CRHR2 while this inhibition in MDA-MB-231 was mainly via CRHR2. Ectopic re-expression of CRHR1 or CRHR2 respectively in HEK293 cells increased E-cadherin expression after CRH stimulation. Furthermore, CRH repressed expression of mesenchymal marker, N-cadherin and induced expression of Occludin, inhibiting EMT in MCF-7 & MDA-MB-231. Our results suggest that CRH may function as a tumor suppressor, at least partly by regulating TGFβ1-mediated EMT. These results may contribute to uncovering the effect of CRH in breast tumorigenesis and progression.

Patterns in space: coordinating adhesion and actomyosin contractility at E-cadherin junctions

Cadherin adhesion receptors are fundamental determinants of tissue organization in health and disease. Increasingly, we have come to appreciate that classical cadherins exert their biological actions through active cooperation with the contractile actin cytoskeleton. Rather than being passive resistors of detachment forces, cadherins can regulate the assembly and mechanics of the contractile apparatus itself. Moreover, coordinate spatial patterning of adhesion and contractility is emerging as a determinant of morphogenesis. Here we review recent developments in cadherins and actin cytoskeleton cooperativity, by focusing on E-cadherin adhesive patterning in the epithelia. Next, we discuss the underlying principles of cellular rearrangement during Drosophila germband extension and epithelial cell extrusion, as models of how planar and apical-lateral patterns of contractility organize tissue architecture.

Wnt signaling in liver fibrosis: progress, challenges and potential directions

Liver fibrosis is a common wound-healing response to chronic liver injuries, including alcoholic or drug toxicity, persistent viral infection, and genetic factors. Myofibroblastic transdifferentiation (MTD) is the pivotal event during liver fibrogenesis, and research in the past few years has identified key mediators and molecular mechanisms responsible for MTD of hepatic stellate cells (HSCs). HSCs are undifferentiated cells which play an important role in liver regeneration. Recent evidence demonstrates that HSCs derive from mesoderm and at least in part via septum transversum and mesothelium, and HSCs express markers for different cell types which derive from multipotent mesenchymal progenitors. There is a regulatory commonality between differentiation of adipocytes and that of HSC, and the shift from adipogenic to myogenic or neuronal phenotype characterizes HSC MTD. Central of this shift is a loss of expression of the master adipogenic regulator peroxisome proliferator activated receptor γ (PPARγ). Restored expression of PPARγ and/or other adipogenic transcription genes can reverse myofibroblastic HSCs to differentiated cells. Vertebrate Wnt and Drosophila wingless are homologous genes, and their translated proteins have been shown to participate in the regulation of cell proliferation, cell polarity, cell differentiation, and other biological roles. More recently, Wnt signaling is implicated in human fibrosing diseases, such as pulmonary fibrosis, renal fibrosis, and liver fibrosis. Blocking the canonical Wnt signal pathway with the co-receptor antagonist Dickkopf-1 (DKK1) abrogates these epigenetic repressions and restores the gene PPARγ expression and HSC differentiation. The identified morphogen mediated epigenetic regulation of PPARγ and HSC differentiation also serves as novel therapeutic targets for liver fibrosis and liver regeneration. In conclusion, the Wnt signaling promotes liver fibrosis by enhancing HSC activation and survival, and we herein discuss what we currently know and what we expect will come in this field in the next future.

Identification of novel small compounds that restore E-cadherin expression and inhibit tumor cell motility and invasiveness

Tumor dissemination and invasive behavior are associated with a majority of cancer-related mortality cases. Loss of E-cadherin, which is caused by several tumor-promoting factors, is associated with metastasis and poor prognosis in many neoplasms. In this study, we aimed to identify small molecule compounds that restore the expression of E-cadherin, because these molecules are most likely to suppress tumor malignancy by restoring E-cadherin function and/or by inhibiting signals that suppress E-cadherin expression. Here, we developed a fluorescence screen system based on E-cadherin expression. A pilot drug library screen revealed that methotrexate (MTX) strongly induces E-cadherin expression in a colorectal cancer cell line, SW620. From the screen for 9600 compounds, we identified 9 hit compounds, which restored the expression of E-cadherin in SW620 and/or a melanoma cell line, SK-MEL-28. We confirmed that MTX and the other identified compounds transcriptionally promote E-cadherin expression. Among these, 2 compounds suppressed migration/invasion capacity in colorectal cancer cells and 3 in melanoma cells. A compound reduced SW620 migration and invasion with subtle effects on cell viability in SW620, SK-MEL-28, and a non-tumor cell line, HaCaT, with decrease in AKT and ERK1/2 protein levels. One of the other compounds reduced SK-MEL-28 cell migration and invasion and affected the viability only of SW620 and SK-MEL-28 cells but not HaCaT cells. These results suggest that these compounds would be attractive lead molecules as anti-metastasis agents.

Role of MUC20 overexpression as a predictor of recurrence and poor outcome in colorectal cancer

Background

Colorectal cancer (CRC) remains one of the most common cancers worldwide. We observed that MUC20 was significantly up-regulated in CRC patients with poor prognosis based on the microarray analysis. However, little is known about the role of MUC20 in CRC.

Methods

Microarray experiments were performed on the Affymetrix U133 plus 2.0 GeneChip Array. The protein and mRNA levels of MUC20 were examined by immunohistochemistry (IHC) and Real-Time quantitative PCR (RT-qPCR) in CRC tissues and adjacent noncancerous tissues (ANCT). ShRNA and overexpression plasmids were used to regulate MUC20 expression in CRC cell lines in vitro; wound healing, Transwell migration assays, and Western blotting were used to detect migration and invasion changes.

Results

MUC20 was one of the up-regulated genes in CRC patients with poor prognosis by microarray. Using IHC and RT-qPCR, we showed that MUC20 expression was significantly higher in CRC tissues than in ANCT (P < 0.05). We further showed that MUC20 overexpression was correlated with recurrence and poor outcome (P < 0.05). The Kaplan-Meier survival curves indicated that disease-free survival (DFS) and overall survival (OS) were significantly worse in CRC patients with MUC20 overexpression. The Cox multivariate analysis revealed that MUC20 overexpression and TNM stage were independent prognostic factors. Elevated expression of MUC20 in cells promoted migration and invasion, whereas ShRNA-mediated knockdown inhibited these processes. In addition, Western blotting demonstrated that MUC20-induced invasion was associated with MMP-2, MMP-3, and E-cadherin.

Conclusions

Cumulatively, MUC20 may serve as an important predictor of recurrence and poor outcome for CRC patients. MUC20 overexpression could enhance migration and invasion abilities of CRC cells. Translation of its roles into clinical practice will need further investigation and additional test validation.

Sleeping giants: emerging roles for the fat cadherins in health and disease

The vertebrate Fat cadherins comprise a small gene family of four members, Fat1-Fat4, all closely related in structure to Drosophila ft and ft2. Over the past decade, knock-out mouse studies, genetic manipulation, and large sequencing projects has aided our understanding of the function of vertebrate Fat cadherins in tissue development and disease. The majority of studies of this family have focused on Fat1, with evidence now showing it can bind enable (ENA)/Vasodilator-stimulated phosphoprotein (VASP), β-catenin and Atrophin proteins to influence cell polarity and motility; HOMER-1 and HOMER-3 proteins to regulate actin accumulation in neuronal synapses; and scribble to influence the Hippo signaling pathway. Fat2 and Fat3 can regulate cell migration in a tissue specific manner and Fat4 appears to influence both planar cell polarity and Hippo signaling recapitulating the activity of Drosophila ft. Knowledge about the exact downstream signaling pathways activated by each family member remains in its infancy, but it is becoming clearer that they have tissue specific and redundant roles in development and may be lost or gained in cancer. In this review, we summarize the recent progress on understanding the role of the Fat cadherin family, integrating the current knowledge of molecular interactions and tissue distributions, together with the accumulating evidence of their changed expression in human disease. The latter is now beginning to promote interest in these molecules as both biomarkers and new targets for therapeutic intervention.

α-Mangostin suppresses lipopolysaccharide-induced invasion by inhibiting matrix metalloproteinase-2/9 and increasing E-cadherin expression through extracellular signal-regulated kinase signaling in pancreatic cancer cells

Invasion and metastasis are major factors in the poor prognosis of pancreatic cancer, which remains one of the most aggressive and lethal diseases worldwide. α-mangostin, a major xanthone compound identified in the pericarp of mangosteen (Garcinia mangostana, Linn; GML), possesses unique biological activities, including antioxidant, antitumor and anti-inflammatory effects. Whether α-mangostin is able to inhibit the invasive ability of pancreatic cancer cells has not been elucidated. In the present study, α-mangostin was shown to inhibit the invasive ability of the pancreatic cancer cell lines MIAPaCa-2 and BxPC-3. The results showed that α-mangostin inhibited the growth of the pancreatic cancer cells in a dose- and time-dependent manner. At concentrations of <5 μM, α-mangostin had no significant effects on cytotoxicity, but significantly inhibited the invasion and migration of pancreatic cancer cells and the expression of matrix metalloproteinase (MMP)-2 and MMP-9, while increasing the expression of E-cadherin. The present data also showed that α-mangostin exerted an inhibitory effect on the phosphorylation of extracellular-signal-regulated kinase (ERK). Furthermore, the reduction of ERK phosphorylation by small interfering RNA (siRNA) potentiated the effect of α-mangostin. Taken together, the data suggest that α-mangostin inhibited the invasion and metastasis of pancreatic cancer cells by reducing MMP-2 and MMP-9 expression, increasing E-cadherin expression and suppressing the ERK signaling pathway. The present study suggests that α-mangostin may be a promising agent against pancreatic cancer.

Metastasis-associated factors facilitating the progression of colorectal cancer

Tumor metastasis remains the principal cause of treatment failure and poor prognosis in patients with colorectal cancer. It is a multistage process which includes proteolysis, motility and migration of cells, proliferation in a new site, and neoangiogenesis. A crucial step in the process of intra- and extra-vasation is the activation of proteolytic enzymes capable of degrading the extracellular matrix (ECM). In this stage, urokinase plasminogen activator receptor (uPAR) and matrix metalloproteinases (MMPs) are necessary. Micrometastases need the presence of growth factor and vascular growth factor so that they can form macrometastasis. In addition, cell adhesion molecules (CAMs) and guanine nucleotide exchange factors (GEFs) play important roles in the progression of colorectal cancer and metastatic migration. Further elucidation of the mechanisms of how these molecules contribute will aid in the identification of diagnostic and prognostic markers as well as therapeutic targets for patients with colorectal metastasis.

Expression and Significance of E-Cadherin and β-Catenins in Pituitary Adenoma

This study used immunohistochemical methods for detecting the expression of E-cadherin and β-catenin in pituitary adenoma. Specimens were collected from 91 cases. EnVision was used for immunohistochemical staining. The results were graded depending on the staining intensity and range. Associations between E-cadherin and β-catenin expression and tumor subtype, invasiveness, and postoperative recurrence were investigated. There was a significant downregulation of E-cadherin and β-catenin in growth hormone (GH)-type tumors when compared with prolactin-type tumors ( uc = 2.693 and 2.109, respectively; P < .05). E-cadherin and β-catenin were downregulated in invasive pituitary adenomas ( uc = 3.563 and 4.166, respectively; P < .05) and in clinically recurring pituitary adenomas ( uc = 2.871 and 3.866, respectively; P < .05). There was no difference in the percentage of invasive prolactin and GH secreting tumors (28.57% and 22.86%, respectively; P > .05). The expression of E-cadherin and β-catenin in pituitary adenoma was significantly downregulated and related to subtype, invasiveness, and postoperative recurrence.

FOXM1 (Forkhead box M1) in tumorigenesis: overexpression in human cancer, implication in tumorigenesis, oncogenic functions, tumor-suppressive properties, and target of anticancer therapy

FOXM1 (Forkhead box M1) is a typical proliferation-associated transcription factor and is also intimately involved in tumorigenesis. FOXM1 stimulates cell proliferation and cell cycle progression by promoting the entry into S-phase and M-phase. Additionally, FOXM1 is required for proper execution of mitosis. In accordance with its role in stimulation of cell proliferation, FOXM1 exhibits a proliferation-specific expression pattern and its expression is regulated by proliferation and anti-proliferation signals as well as by proto-oncoproteins and tumor suppressors. Since these factors are often mutated, overexpressed, or lost in human cancer, the normal control of the foxm1 expression by them provides the basis for deregulated FOXM1 expression in tumors. Accordingly, FOXM1 is overexpressed in many types of human cancer. FOXM1 is intimately involved in tumorigenesis, because it contributes to oncogenic transformation and participates in tumor initiation, growth, and progression, including positive effects on angiogenesis, migration, invasion, epithelial-mesenchymal transition, metastasis, recruitment of tumor-associated macrophages, tumor-associated lung inflammation, self-renewal capacity of cancer cells, prevention of premature cellular senescence, and chemotherapeutic drug resistance. However, in the context of urethane-induced lung tumorigenesis, FOXM1 has an unexpected tumor suppressor role in endothelial cells because it limits pulmonary inflammation and canonical Wnt signaling in epithelial lung cells, thereby restricting carcinogenesis. Accordingly, FOXM1 plays a role in homologous recombination repair of DNA double-strand breaks and maintenance of genomic stability, that is, prevention of polyploidy and aneuploidy. The implication of FOXM1 in tumorigenesis makes it an attractive target for anticancer therapy, and several antitumor drugs have been reported to decrease FOXM1 expression.