Cadherin switching: essential for behavioral but not morphological changes during an epithelium-to-mesenchyme transition

Prognostic value of epithelial-mesenchymal transition markers in clear cell renal cell carcinoma

Epithelial-to-mesenchymal transition (EMT) is important in tumor invasiveness and metastasis. We aimed to determine prognostic value of six key EMT markers (CDH1, CDH2, SNAI1, SNAI2, VIM, TWIST1) in clear cell renal cell carcinoma (ccRCC). A total of 533 ccRCC patients with RNASeq data from The Cancer Genome Atlas (TCGA) cohort were included for analysis. Gene expression of these EMT markers was compared between tumor and normal tissues based on Oncomine database and TCGA cohort. Their correlations with progression-free survival (PFS) and overall survival (OS) were also examined in both TCGA cohort and FUSCC (Fudan University Shanghai Cancer Center) cohort. Cox proportional hazards regression model and Kaplan-Meier plot were used to assess the relative factors. Functional enrichment analyses were utilized to describe biologic function annotations and significantly involved hallmarks pathways of each gene. We found that Epithelial marker, CDH1 expression was lower, while mesenchymal markers (CDH2, SNAI1, VIM, TWIST1) expression was higher in ccRCC primary tumors. In the TCGA cohort, we found that patients with higher expression of VIM, TWIST1 or lower expression of CDH1 had worse prognosis. Further, in the FUSCC cohort, we confirmed the predictive ability of mesenchymal markers and epithelial marker expression in PFS and OS of ccRCC patients. After generating Cox regression models, EMT markers (CDH1, SNAI1, VIM, and TWIST1) were independent prognostic factors of both PFS and OS in ccRCC patients. Our preliminary EMT prediction model can facilitate further screening of EMT biomarkers and cast a better understanding of EMT gene function in ccRCC.

BMPR2 acts as a gatekeeper to protect endothelial cells from increased TGFβ responses and altered cell mechanics

Balanced transforming growth factor-beta (TGFβ)/bone morphogenetic protein (BMP)-signaling is essential for tissue formation and homeostasis. While gain in TGFβ signaling is often found in diseases, the underlying cellular mechanisms remain poorly defined. Here we show that the receptor BMP type 2 (BMPR2) serves as a central gatekeeper of this balance, highlighted by its deregulation in diseases such as pulmonary arterial hypertension (PAH). We show that BMPR2 deficiency in endothelial cells (ECs) does not abolish pan-BMP-SMAD1/5 responses but instead favors the formation of mixed-heteromeric receptor complexes comprising BMPR1/TGFβR1/TGFβR2 that enable enhanced cellular responses toward TGFβ. These include canonical TGFβ-SMAD2/3 and lateral TGFβ-SMAD1/5 signaling as well as formation of mixed SMAD complexes. Moreover, BMPR2-deficient cells express genes indicative of altered biophysical properties, including up-regulation of extracellular matrix (ECM) proteins such as fibrillin-1 (FBN1) and of integrins. As such, we identified accumulation of ectopic FBN1 fibers remodeled with fibronectin (FN) in junctions of BMPR2-deficient ECs. Ectopic FBN1 deposits were also found in proximity to contractile intimal cells in pulmonary artery lesions of BMPR2-deficient heritable PAH (HPAH) patients. In BMPR2-deficient cells, we show that ectopic FBN1 is accompanied by active β1-integrin highly abundant in integrin-linked kinase (ILK) mechano-complexes at cell junctions. Increased integrin-dependent adhesion, spreading, and actomyosin-dependent contractility facilitates the retrieval of active TGFβ from its latent fibrillin-bound depots. We propose that loss of BMPR2 favors endothelial-to-mesenchymal transition (EndMT) allowing cells of myo-fibroblastic character to create a vicious feed-forward process leading to hyperactivated TGFβ signaling. In summary, our findings highlight a crucial role for BMPR2 as a gatekeeper of endothelial homeostasis protecting cells from increased TGFβ responses and integrin-mediated mechano-transduction.

Changes in oncogenic protein levels in peri-implant oral malignancy: a case report

Background

Oral squamous cell carcinoma (OSCC) constitutes a group of tumors that exhibit heterogeneous biology, histopathology, and clinical behaviors.

Case presentation

A 73-year-old male had a whitish leukoplakia-like lesion around inflamed peri-implant area (#42, #43, and #44), and this lesion had transformed to OSCC within 3 years. He underwent mass resection, selective neck dissection, and reconstructive surgery. To detect any carcinogenesis progression, we examined the removed tumor tissue as well as the patient’s preoperative and postoperative sera to identify causative oncogenic proteins using immunoprecipitation high-performance liquid chromatography (IP-HPLC).

Conclusions

The protein expression levels of p53, E-cadherin, β-catenin, MMP-10, HER2, NRAS, Met, HER2, and ERb were significantly lower in the serum collected on postoperative day 10 than in the preoperative serum, and if these proteins are consistently not elevated in the serum 3 months after surgery compared with the preoperative serum, these proteins can be potential oncogenic proteins. However, we also found that the serum extracted 3 months after the operation had elevated levels of oncogenic proteins compared with that of the preoperative and 10-day postoperative serum indicating the possibility of tumor recurrence. At postoperative follow-up period, ipsilateral neck metastasis and second primary lesion were found and additional surgery was performed to the patient. IP-HPLC using the patient’s serum shows the possibility of oncogenic protein detection. However, follow-up IP-HPLC data is needed to find out patient-specific prognostic factors.

Association of the Gutta-Induced Microenvironment With Corneal Endothelial Cell Behavior and Demise in Fuchs Endothelial Corneal Dystrophy

Importance

The number and size of guttae increase over time in Fuchs endothelial corneal dystrophy (FECD); however, the association between these physical parameters and disease pathogenesis is unclear.

Objective

To determine the role of guttae in corneal endothelial cell function.

Design, Settings, and Participants

In an in vitro model, cells from a human corneal endothelial cell line, HCENC-21T, were seeded on decellularized normal (n = 30) and FECD (n = 70) endothelial basement (Descemet) membranes (DMs). Normal human corneas were sent to our laboratory from 3 sources. The study took place at the Schepens Eye Research Institute, Massachusetts Eye and Ear, Boston, and was performed from September 2015 to July 2017. Normal DMs were obtained from 3 different tissue banks and FECD-DMs were obtained from patients undergoing endothelial keratoplasty in 2 departments.

Main Outcomes and Measures

Endothelial cell shape, growth, and migration were assessed by live-cell imaging, and gene expression analysis as a function of guttae diameter was assessed by laser capture microscopy.

Results

Mean (SD) age of normal-DMs donors was 65.6 (4.4) years (16 women [53%]), and mean (SD) age of FECD-DMs donors was 68.9 (10.6) years (43 women [61%]). Cells covered a greater area (mean [SD], 97.7% [8.5%]) with a greater mean (SD) number of cells (2083 [153] cells/mm2) on the normal DMs compared with the FECD DMs (72.8% [11%]; P = .02 and 1541 [221] cells/mm2 221/mm2; P = .01, respectively). Differences in endothelial cell growth over guttae were observed on FECD DMs depending on the guttae diameter. Guttae with a mean (SD) diameter of 10.5 (2.9) μm did not impede cell growth, whereas those with a diameter of 21.1 (4.9) μm were covered only by the cell cytoplasm. Guttae with the largest mean (SD) diameter, 31.8 (3.8) μm, were not covered by cells, which instead surrounded them in a rosette pattern. Moreover, cells adjacent to large guttae upregulated αSMA, N-cadherin, Snail1, and NOX4 genes compared with ones grown on normal DMs or small guttae. Furthermore, large guttae induced TUNEL-positive apoptosis in a rosette pattern, similar to ex vivo FECD specimens.

Conclusions and Relevance

These findings highlight the important role of guttae in endothelial cell growth, migration, and survival. These data suggest that cell therapy procedures in FECD might be guided by the diameter of the host guttae if subsequent clinical studies confirm these laboratory findings.

Downregulation of lncRNA AFAP1-AS1 by oridonin inhibits the epithelial-to-mesenchymal transition and proliferation of pancreatic cancer cells

Recent studies have demonstrated that the expression of the long non-coding RNA (lncRNA) AFAP1-AS1 in pancreatic cancer is negatively correlated with survival and prognosis. However, the effects of oridonin and lncRNA AFAP1-AS1 on the epithelial-to-mesenchymal transition (EMT) and migration of pancreatic cancer cells have not been fully elucidated. Surgery is the only potentially curative method for pancreatic cancer, but postoperative recurrence and metastasis are common. The aim of the present study was to assess the effect of oridonin and lncRNA AFAP1-AS1 silencing on pancreatic cancer cells. The pancreatic cancer cell lines BxPC-3 and PANC-1 cells were transfected with siAFAP1-AS1 and its negative control (siNC). After that, oridonin was used to treat the siAFAP1-AS1-transfected cells. The expression of lncRNA AFAP1-AS1 was downregulated in the pancreatic cancer cell lines BxPC-3 and PANC-1. The apoptosis and cell cycle progression of pancreatic cancer cells were evaluated by flow cytometry and Hoechst 33258 staining. Metastasis and invasion of BxPC-3 and PANC-1 cells were detected by transwell migration assay, real-time cell analysis, and western blot analysis. Cells were transfected with the lentiviral siAFAP1-AS1 and siNC, and tumorigenesis was evaluated in BALB/C nude mice. Immunohistochemical examination was used to verify the effects of oridonin and siAFAP1-AS1 on pancreatic cancer. The results demonstrated that the combination of oridonin and siAFAP1-AS1 inhibited pancreatic cancer cell proliferation, induced apoptosis, arrested cell cycle progression, prevented the migration, regulated EMT-related protein expression in BxPC-3 and PANC-1 cells, and inhibited pancreatic cancer cell tumorigenicity and EMT in nude mice.

IL-6 Impairs the Activity of Vitamin D3 in the Regulation of Epithelial-Mesenchymal Transition in Triple Negative Breast Cancer

Objective:

The present study aimed to investigate the possible role of IL-6 and 1α,25-dihydroxyvitamin D3 (1,25D) signaling in epithelial-mesenchymal transition (EMT) and stemness in triple-negative breast cancer (TNBC) cell line.

Methods:

TNBC cell line, HCC 1806, was treated with IL-6 and 1,25D for three and six days. Also, the role of vitamin D receptor (VDR) was studied by transfection of TNBC cell line with VDR gene and transfection efficiency was assessed using Human VDR enzyme-linked immunosorbent assay (ELISA). Changes in E-cadherin gene expression were analyzed by quantitative real-time PCR (qRT-PCR). Also, changes in CD44+ cells were analyzed by flow cytometry. Finally, morphological changes were investigated by light microscopy after 6 days.

Results:

Treatment of HCC1806 cells with IL-6 has no significant effect either on E-cadherin gene expression or CD44+ cells, (p > 0.05). However, E-cadherin gene expression was significantly up-regulated after treatment with 1,25D for 6 days, (p < 0.05). Also, CD44+ cells were significantly reduced after treatment with 1,25D either for 3 or 6 days, (p < 0.05). Transfection of TNBC cell line with VDR gene significantly up-regulated VDR protein expression, (p < 0.05). In addition, overexpression of VDR in TNBC cells and treatment with 1,25D significantly up-regulated E-cadherin gene expression, (p < 0.05) and reduced CD44+ cells, (p < 0.05). Moreover, transfection with VDR and treatment with a combination of 1,25D and IL-6 significantly down-regulated E-cadherin gene expression and increased CD44+ cells compared with transfected cells with VDR treated with 1,25D alone, (p < 0.05). No significant morphological changes were observed in treated cells, 6 days post-treatment.

Conclusion:

The presence of IL-6 in the breast tumor microenvironment may impair the activity of vitamin D3 signaling, limiting its anti-tumor effects in TNBC.

The Role Played by SLUG, an Epithelial-Mesenchymal Transition Factor, in Invasion and Therapeutic Resistance of Malignant Glioma

In malignant gliomas, invasive phenotype and cancer stemness promoting resurgence of residual tumor cells render treatment very difficult. Hence, identification of epithelial-mesenchymal transition (EMT) factors associated with invasion and stemness of glioma cells is critical. To address the issue, we investigated several EMT factors in hypermotile U87MG and U251 cells, orthotopic mouse glioma model, and human glioma samples. Of several EMT markers, SLUG expression was notably increased at the invasive fronts of gliomas, both in mouse tumor grafts and human glioma samples. The biological role played by SLUG was investigated using a colony-forming assay after chemotherapy and irradiation, and by employing a neurosphere culture assay. The effect of SLUG on glioma progression was examined in our patient cohort and samples, and compared to large public data from the REMBRANDT and TCGA. Genetic upregulation of SLUG was associated with increased levels of stemness factors and enhanced resistance to radiation and temozolomide. In our cohort, patients exhibiting lower-level SLUG expression evidenced longer progression-free survival (P = 0.042). Also, in the REMBRANDT dataset, a group in which SLUG was downregulated exhibited a significant survival benefit (P < 0.001). Although paired glioblastoma samples from our patients did not show a significant increase of SLUG expression, increased mRNA levels of SLUG were found in recurrent glioblastoma from TCGA (P = 0.052), and in temozolomide-treated glioma cells and mouse tumor grafts. SLUG may contribute to glioma progression by controlling invasion at infiltrating margins, associated with increased stemness and therapeutic resistance.

A Correlative Study of N-Cadherin Expression with Different Grades of Oral Squamous Cell Carcinoma Projecting as a Marker of Epithelial to Mesenchymal Transition in Tumor Progression

Background: Epithelial cells typically express E-cadherin where as N-cadherin expressed by mesenchymal cells. The epithelial to mesenchymal transition (EMT) is a process by which epithelial cells lose their cell polarity and cell-cell adhesion, and gain migratory and invasive properties to become mesenchymal cells. EMT is typical for carcinoma cells during tumor progression and correlate with the local invasiveness and metastatic potential of the tumor. Oral squamous cell carcinoma is a malignant neoplasm arising from the mucosal epithelium of the oral cavity. It can be classified as well; moderate and poor depends on a tumor cells resemblance to its tissue of origin. Materials and Methods: A total of 130 cases of histopathologically diagnosed as OSCC were selected for the study, out of which 66,38 and 26 were well, moderate and poorly differentiated respectively. One section was stained with Haematoxylin and Eosin and the other section for N-cadherin immunohistochemical study. Then the N-cadherin expression was correlated histopathologically with different grades of OSCC. Statistical analysis was carried out mainly by Chi-Square analysis. Results: Among the 66 cases of WDSCC mean value of N-cadherin expression was 1.79, 38 cases of MDSCC mean value of N-cadherin expression was 4.16 and among the 26 cases of PDSCC the mean value was 6.38.That means the value of N- cadherin expression was progressively increasing with decreased differentiation of the tumor cells. The statistical analysis also shown it was highly significant (P<0.001). Conclusion: A correlative study of N-cadherin expression with different grades of OSCC will be useful to predict the state of tumor progression and also it may give accuracy for histopathogical grading of the tumor.

TBL1XR1 is involved in c-Met-mediated tumorigenesis of human nonsmall cell lung cancer

Nonsmall cell lung carcinoma (NSCLC) contributes to the highest number of cancer deaths globally. Metastases and chemoresistance are two major confounders to the treatment efficacy in NSCLC. Transducin (β)-like 1 X-linked receptor 1 (TBL1XR1) has been associated with high rates of metastases in breast, gastric, and stomach cancers. However, the role of TBL1XR1 in lung cancers remains underexplored. We selected matched and cancerous lung tissues to establish the upregulation of TBL1XR1. Using in vitro assays, we assessed the influence of TBL1XR1 on various cancer phenotypes, namely cell proliferation, chemoresistance, invasion, and metastases in a CRISPR-Cas9-mediated knock out model (A549 cells), and H460 cell lines overexpressing TBL1XR1. We found that TBL1XR1 is overexpressed in NSCLC tissue and patient sera in comparison to paired adjacent normal tissue. Overexpression of TBL1XR1 in NSCLC cell lines mediates cell survival, proliferation, and metastases. TBL1XR1 was found to regulate MEK and Akt pathways through their master regulator c-Met. We observed that activation of c-Met is downregulated in the absence of TBL1XR1. Our study strengthens the contention that TBL1XR1 is a biomarker for prognosis of NSCLC. It may also be considered as an adjunct or core therapeutic target to overcome cisplatin resistance in lung cancers.

Control of Invasion by Epithelial-to-Mesenchymal Transition Programs during Metastasis

Epithelial-to-mesenchymal transition (EMT) programs contribute to the acquisition of invasive properties that are essential for metastasis. It is well established that EMT programs alter cell state and promote invasive behavior. This review discusses how rather than following one specific program, EMT states are diverse in their regulation and invasive properties. Analysis across a spectrum of models using a combination of approaches has revealed how unique features of distinct EMT programs dictate whether tumor cells invade as single cells or collectively as cohesive groups of cells. It has also been shown that the mode of collective invasion is determined by the nature of the EMT, with cells in a trailblazer-type EMT state being capable of initiating collective invasion, whereas cells that have undergone an opportunist-type EMT are dependent on extrinsic factors to invade. In addition to altering cell intrinsic properties, EMT programs can influence invasion through non-cell autonomous mechanisms. Analysis of tumor subpopulations has demonstrated how EMT-induced cells can drive the invasion of sibling epithelial populations through paracrine signaling and remodeling of the microenvironment. Importantly, the variation in invasive properties controlled by EMT programs influences the kinetics and location of metastasis.

Effect of genetic variants in cell adhesion pathways on the biochemical recurrence in prostate cancer patients with radical prostatectomy

The aberrant expression of cell adhesion molecules is a hallmark of epithelial‐to‐mesenchymal transition, resulting in the transformation of cancer cells to a more aggressive phenotype. This study investigated the association between genetic variants in cell adhesion pathways and the prognosis of patients with prostate cancer following radical prostatectomy (RP). A total of 18 haplotype‐tagging single‐nucleotide polymorphisms (SNPs) in eight cancer‐related adhesion molecules were genotyped in 458 prostate cancer patients, followed by the replication of the top SNPs in an additional set of 185 patients. Log‐rank test and multivariate Cox regression analysis adjusted for covariates were used to evaluate associations with the risk of biochemical recurrence (BCR) after RP. In the discovery set, four SNPs in CDH2 were marginally associated with BCR. Among these, CDH2 rs643555C > T was found to be associated with BCR in the replication set. Patients with rs643555TT genotype had a significantly shorter BCR‐free survival compared with those with CC/CT genotypes in the combined analysis (adjusted hazard ratio 1.78, 95% confidence interval 1.19‐2.67, P = 0.005). Additional analyses revealed that rs643555T was associated with higher expression of CDH2, and upregulated CDH2 was correlated with tumor aggressiveness and shortened BCR‐free survival. In conclusion, rs643555C > T affects CDH2 expression, and thus influences BCR in localized prostate cancer patients treated with RP. CDH2 rs643555 may be a promising biomarker to identify patients at high risk of poor prostate cancer prognosis.

Diallyl disulphide suppresses the cannonical Wnt signaling pathway and reverses the fibronectin-induced epithelial mesenchymal transition of A549 lung cancer cells

Globally, non-small cell lung cancer is a leading cause of cancer-related mortality and about 40% of these cancers are detected in the metastatic stage. Epithelial mesenchymal transition (EMT) plays a critical role during malignant transformation, and the extracellular matrix component, fibronectin (FN), is a known inducer of invasion and metastasis. Diallyl disulphide (DADS), a bioactive component of garlic, exhibits a wide spectrum of biological activities including the inhibition of cancer cell migration and invasion. The present study was aimed at deciphering the effect of DADS on the regulation of FN-induced EMT in A549 lung cancer cells. DADS suppressed the FN-induced invasion and migration potential of A549 cells which may be attributed to the reduced activity of gelatinases. DADS suppressed the FN-aggravated EMT of A549 cells by the upregulation of the epithelial markers, E-cadherin and cytokeratin-18, and the downregulation of the mesenchymal markers, N-cadherin and vimentin, and the transcription factors, snail, slug and twist. DADS was effective in inhibiting the nuclear translocation of β-catenin and the phosphorylation of glycogen synthase kinase-3β and in suppressing the activity of dishevelled homolog 2 and T-cell-factor/lymphoid enhancer factor in FN-induced A549 cells. Cumulatively, this study indicated that DADS might be able to reverse FN-induced EMT in A549 cells via the suppression of Wnt signaling.

Competitive endogenous RNA is an intrinsic component of EMT regulatory circuits and modulates EMT

The competitive endogenous RNA (ceRNA) hypothesis suggests an intrinsic mechanism to regulate biological processes. However, whether the dynamic changes of ceRNAs can modulate miRNA activities remains controversial. Here, we examine the dynamics of ceRNAs during TGF-β-induced epithelial-to-mesenchymal transition (EMT). We observe that TGFBI, a transcript highly induced during EMT in A549 cells, acts as the ceRNA for miR-21 to modulate EMT. We further identify FN1 as the ceRNA for miR-200c in the canonical SNAIL-ZEB-miR200 circuit in MCF10A cells. Experimental assays and computational simulations demonstrate that the dynamically induced ceRNAs are directly coupled with the canonical double negative feedback loops and are critical to the induction of EMT. These results help to establish the relevance of ceRNA in cancer EMT and suggest that ceRNA is an intrinsic component of the EMT regulatory circuit and may represent a potential target to disrupt EMT during tumorigenesis.

Competitive endogenous RNAs help to regulate biological processes by regulating miRNA activity levels. Here the author show TGFBI acts as a ceRNA for miR-21 in the epithelial-to-mesenchymal transition.

The cadherin-catenin complex is necessary for cell adhesion and embryogenesis in Nematostella vectensis

The cadherin-catenin complex is a conserved, calcium-dependent cell-cell adhesion module that is necessary for normal development and the maintenance of tissue integrity in bilaterian animals. Despite longstanding evidence of a deep ancestry of calcium-dependent cell adhesion in animals, the requirement of the cadherin-catenin complex to coordinate cell-cell adhesion has not been tested directly in a non-bilaterian organism. Here, we provide the first analysis of classical cadherins and catenins in the Starlet Sea Anemone, Nematostella vectensis. Gene expression, protein localization, siRNA-mediated knockdown of α-catenin, and calcium-dependent cell aggregation assays provide evidence that a bonafide cadherin-catenin complex is present in the early embryo, and that α-catenin is required for normal embryonic development and the formation of cell-cell adhesions between cells dissociated from whole embryos. Together these results support the hypothesis that the cadherin-catenin complex was likely a complete and functional cell-cell adhesion module in the last common cnidarian-bilaterian ancestor. SUMMARY STATEMENT: Embryonic manipulations and ex vivo adhesion assays in the sea anemone, Nematostella vectensis, indicate that the necessity of the cadherin-catenin complex for mediating cell-cell adhesion is deeply conserved in animal evolution.

Oral and Oropharyngeal squamous cell carcinoma: prognostic and predictive parameters in the etiopathogenetic route

Oral and oropharyngeal squamous cell carcinoma (OSCC and OPSCC) represents an increasing problem in the global public health. Indeed, squamous cell carcinoma is the most frequent malignancy in oral cavity and 1 of the 10 most common cancers worldwide. According to the most recent GLOBOCAN estimate in Europe between 2012 and 2015, there was an overall increasing incidence and mortality for oral cancer, mostly HPV-related in the oropharyngeal region with evidence of significant differences from the prognostic and therapeutic point of view. Areas covered: Until now, the management of the patients is based on classical histologic parameters such as TNM and tumor grading, but new molecular and cell markers have been investigated to improve patients' treatment and survival. Therefore, there is a need for new biomarkers characterizing the cancer diversity, with the consequent possibility of patient stratification for specific treatment. Expert commentary: This review aims to discuss some of the most relevant and novel genetic, epigenetic, and histological prognostic biomarkers in oral cancer, highlighting the main differences between HPV-unrelated oral squamous cell carcinoma (OSCC) and HPV-related oropharyngeal squamous cell carcinoma (OPSCC) that may aid in stratifying prognostic subgroups and rationalizing treatment decisions.

Conserved regulation of RNA processing in somatic cell reprogramming

BACKGROUND

Along with the reorganization of epigenetic and transcriptional networks, somatic cell reprogramming brings about numerous changes at the level of RNA processing. These include the expression of specific transcript isoforms and 3' untranslated regions. A number of studies have uncovered RNA processing factors that modulate the efficiency of the reprogramming process. However, a comprehensive evaluation of the involvement of RNA processing factors in the reprogramming of somatic mammalian cells is lacking.

RESULTS

Here, we used data from a large number of studies carried out in three mammalian species, mouse, chimpanzee and human, to uncover consistent changes in gene expression upon reprogramming of somatic cells. We found that a core set of nine splicing factors have consistent changes across the majority of data sets in all three species. Most striking among these are ESRP1 and ESRP2, which accelerate and enhance the efficiency of somatic cell reprogramming by promoting isoform expression changes associated with mesenchymal-to-epithelial transition. We further identify genes and processes in which splicing changes are observed in both human and mouse.

CONCLUSIONS

Our results provide a general resource for gene expression and splicing changes that take place during somatic cell reprogramming. Furthermore, they support the concept that splicing factors with evolutionarily conserved, cell type-specific expression can modulate the efficiency of the process by reinforcing intermediate states resembling the cell types in which these factors are normally expressed.

PARP-1/2 Inhibitor Olaparib Prevents or Partially Reverts EMT Induced by TGF-β in NMuMG Cells

Poly- adenosine diphosphate (ADP)-ribose (PAR) is a polymer synthesized as a posttranslational modification by some poly (ADP-ribose) polymerases (PARPs), namely PARP-1, PARP-2, tankyrase-1, and tankyrase-2 (TNKS-1/2). PARP-1 is nuclear and has also been detected in extracellular vesicles. PARP-2 and TNKS-1/2 are distributed in nuclei and cytoplasm. PARP or PAR alterations have been described in tumors, and in particular by influencing the Epithelial- Mesenchymal Transition (EMT), which influences cell migration and drug resistance in cancer cells. Pro-EMT and anti-EMT effects of PARP-1 have been reported while whether PAR changes occur specifically during EMT is currently unknown. The PARP-1/2 inhibitor Olaparib (OLA) is approved by FDA to treat certain patients harboring cancers with impaired homologous recombination. Here, we studied PAR changes and OLA effects on EMT. Total and nuclear PAR increased in EMT while PAR belts were disassembled. OLA prevented EMT, according to: (i) molecular markers evaluated by immuno-cytofluorescence/image quantification, Western blots, and RNA quantitation, (ii) morphological changes expressed as anisotropy, and (iii) migration capacity in the scratch assay. OLA also partially reversed EMT. OLA might work through unconventional mechanisms of action (different from synthetic lethality), even in non-BRCA (breast cancer 1 gene) mutated cancers.

FGFR1β is a driver isoform of FGFR1 alternative splicing in breast cancer cells

Abnormal FGFR1 alternative splicing is correlated with tumorigenicity and poor prognosis in several tumor types. We sought to determine the roles of FGFR1α and FGFR1β variants in breast cancer. TCGA samples and cell lines were analyzed for FGFR1α/FGFR1β expression. MCF-10A cells were used to overexpress these variants. Cell growth and transformation were assessed by SRB, colony formation, 3D-Matrigel, soft agar, cell motility assays. In TCGA, compared to FGFR1 non-amplified samples, FGFR1-amplified samples had significantly higher FGFR1α but not FGFR1β levels. FGFR1β expression levels and FGFR1β/FGFR1α ratio were higher in basal subtype samples than in ER-positive/luminal samples in both TCGA and breast cancer cell lines. Both FGFR1α and FGFR1β induced transformation of MCF-10A cells. However, only FGFR1β-expressing cells, not FGFR1α, enhanced cell growth and cell motility. Cells with higher FGFR1β levels and FGFR1β/FGFR1α ratio were more sensitive to FGFR inhibitor BGJ-398. Interestingly, in ER-negative cells, FGFR inhibitors decreased FGFR1β levels, likely by increasing expression of splicing repressor PTBP1. In ER-positive cells, estrogen treatment increased FGFR1β levels by decreasing PTBP1 expression, which was blocked by 4-OHT. Lastly, combination treatment with BGJ-398 and 4-OHT synergistically inhibited cell survival. These findings suggest that FGFR1 alternative FGFR1α/FGFR1β splicing plays an important role in breast cancer.

Immunohistochemical Expression of E- and N-Cadherin in Nodular Prostatic Hyperplasia and Prostatic Carcinoma

Background:

Different theories have been postulated to explain the development of nodular prostatic hyperplasia (NPH). Epithelial to mesenchymal transition (EMT) is a physiologic process in which the epithelial cells lose their polarity and cell-cell adhesion and acquire a mesenchymal phenotype.

Aim:

The aim of the present study is to investigate the potential role of E- and N-cadherin in the induction of EMT in NPH and prostatic carcinoma.

Methods:

This study was carried out on 55 cases of NPH and 20 cases prostatic carcinoma for evaluation of immunohistochemical expression of E and N cadherins.

Results:

Most NPH (54/55 cases, 98.2%) and all cases of prostatic carcinoma showed positive N-cadherin expression in prostatic glands and stroma. High percentage of N-cadherin expression by stromal cells was significantly in favor of prostatic carcinoma compared to NPH. High percentage of N-cadherin expression by epithelial cells of carcinoma group was significantly associated with young age while its high expression by stromal cells was significantly associated with multicentricity. About 96.4% of NPH and 75% of prostatic carcinoma showed positive E-cadherin expression with a significant difference. No significant association between E-cadherin and N-cadherins in both NPH and prostatic carcinoma was identified.

Conclusions:

The prominent expression of N-cadherin in large numbers of NPH and prostate carcinoma cases in the epithelial and stromal components could point to the occurrence of EMT in those diseases. It also opens a new gate for treatment of those patients by targeting N-cadherin molecule. The absence of inverse association between E-cadherin and N-cadherins in NPH and prostatic carcinoma may indicate that cadherin switch is not an essential step for the development of EMT.

Inhibin B suppresses anoikis resistance and migration through the transforming growth factor-β signaling pathway in nasopharyngeal carcinoma

Inhibin B (INHBB), a heterodimer of a common α‐subunit and a βB‐subunit, is a glycoprotein belonging to the transforming growth factor‐β (TGF‐β) family. In this study, we observed INHBB expression was reduced in nasopharyngeal carcinoma (NPC) tissues compared to non‐tumor nasopharyngeal epithelium tissues, and INHBB was associated with lymph node metastasis, stage of disease, and clinical progress. Positive expression of INHBB in NPC predicted a better prognosis (overall survival, P = 0.038). However, the molecular mechanisms of INHBB have not been addressed in NPC. We induced anoikis‐resistant cells in NPC cell lines under anchorage‐independent conditions, then found epithelial‐mesenchymal transition markers changed, cell apoptosis decreased, cell cycle was modified, and invasion strengthened in anoikis‐resistant NPC cells. These anoikis‐resistant NPC cells showed decreased expression of INHBB compared with adhesion cells. Furthermore, INHBB was found to influence the above‐mentioned changes. In the anoikis‐resistant NPC cells with INHBB overexpression, apoptotic cells increased, S phase cells weakened, vimentin, matrix metallopeptidase‐9, and vascular endothelial growth factor A expression were downregulated, and E‐cadherin expression was upregulated, and vice versa in knockdown of INHBB (INHBB shRNA) anoikis‐resistant NPC cells. Diminished INHBB expression could activate the TGF‐β pathway to phosphorylate Smad2/3 and form complexes in the nucleus, which resulted in the above changes. Thus, our results revealed for the first time that INHBB could suppress anoikis resistance and migration of NPC cells by the TGF‐β signaling pathway, decrease p53 overexpression, and could serve as a potential biomarker for NPC metastasis and prognosis as well as a therapeutic application.

Foxf2 plays a dual role during transforming growth factor beta-induced epithelial to mesenchymal transition by promoting apoptosis yet enabling cell junction dissolution and migration

Background

The most life-threatening step during malignant tumor progression is reached when cancer cells leave the primary tumor mass and seed metastasis in distant organs. To infiltrate the surrounding tissue and disseminate throughout the body, single motile tumor cells leave the tumor mass by breaking down cell-cell contacts in a process called epithelial to mesenchymal transition (EMT). An EMT is a complex molecular and cellular program enabling epithelial cells to abandon their differentiated phenotype, including cell-cell adhesion and cell polarity, and to acquire mesenchymal features and invasive properties.

Methods

We employed gene expression profiling and functional experiments to study transcriptional control of transforming growth factor (TGF)β-induced EMT in normal murine mammary gland epithelial (NMuMG) cells.

Results

We identified that expression of the transcription factor forkhead box protein F2 (Foxf2) is upregulated during the EMT process. Although it is not required to gain mesenchymal markers, Foxf2 is essential for the disruption of cell junctions and the downregulation of epithelial markers in NMuMG cells treated with TGFβ. Foxf2 is critical for the downregulation of E-cadherin by promoting the expression of the transcriptional repressors of E-cadherin, Zeb1 and Zeb2, while repressing expression of the epithelial maintenance factor Id2 and miRNA 200 family members. Moreover, Foxf2 is required for TGFβ-mediated apoptosis during EMT by the transcriptional activation of the proapoptotic BH3-only protein Noxa and by the negative regulation of epidermal growth factor receptor (EGFR)-mediated survival signaling through direct repression of its ligands betacellulin and amphiregulin. The dual function of Foxf2 during EMT is underscored by the finding that high Foxf2 expression correlates with good prognosis in patients with early noninvasive stages of breast cancer, but with poor prognosis in advanced breast cancer.

Conclusions

Our data identify the transcription factor Foxf2 as one of the important regulators of EMT, displaying a dual function in promoting tumor cell apoptosis as well as tumor cell migration.

Electronic supplementary material

The online version of this article (10.1186/s13058-018-1043-6) contains supplementary material, which is available to authorized users.

Stochastic phenotype switching leads to intratumor heterogeneity in human liver cancer

Intratumor heterogeneity is increasingly recognized as a major factor impacting diagnosis and personalized treatment of cancer. We characterized stochastic phenotype switching as a mechanism contributing to intratumor heterogeneity and malignant potential of liver cancer. Clonal analysis of primary tumor cell cultures of a human sarcomatoid cholangiocarcinoma identified different types of self-propagating subclones characterized by stable (keratin-7-positive or keratin-7-negative) phenotypes and an unstable phenotype consisting of mixtures of keratin-7-positive and keratin-7-negative cells, which lack stem cell features but may reversibly switch their phenotypes. Transcriptome sequencing and immunohistochemical studies with the markers Zeb1 and CD146/MCAM demonstrated that switching between phenotypes is linked to changes in gene expression related but not identical to epithelial-mesenchymal transition. Stochastic phenotype switching occurred during mitosis and did not correlate with changes in DNA methylation. Xenotransplantation assays with different cellular subclones demonstrated increased tumorigenicity of cells showing phenotype switching, resulting in tumors morphologically resembling the invasive component of primary tumor and metastasis.

CONCLUSION

Our data demonstrate that stochastic phenotype switching contributes to intratumor heterogeneity and that cells with a switching phenotype have increased malignant potential. (Hepatology 2017).

Opposite functions of GSN and OAS2 on colorectal cancer metastasis, mediating perineural and lymphovascular invasion, respectively

The present study aimed to identify molecules associated with lymphovascular invasion (LVI) and perineural invasion (PNI) and to examine their biological behavior in colorectal cancer (CRC). LVI- and PNI-associated molecules were identified and verified using sequential processes including (1) identification of 117 recurrence-associated genes differentially expressed on RNA-seq analysis using primary cancer tissues from 130 CRC patients with and without systemic recurrence; (2) analysis of molecules associated with LVI and PNI; (3) assessment of biological properties by measuring proliferation, anoikis, invasion/migration, epithelial-mesenchymal transition and autophagy flux; and (4) verification of disease-free survival using public datasets. Gelsolin (GSN) and 2'-5'-oligoadenylate synthetase 2 (OAS2) were associated with PNI and LVI, respectively. Invasion potential was >2-fold greater in GSN-overexpressing LoVo cells than in control cells (p<0.001-0.005), whereas OAS2-overexpressing RKO cells showed reduced invasion (p<0.001-0.005). GSN downregulated E-cadherin, β-catenin, claudin-1 and snail, and upregulated N-cadherin and ZEB1, whereas OAS2 overexpression had the opposite effects. Several autophagy-related proteins including ATG5-12, ATG6/BECN1, ATG7 and ATG101 were downregulated in GSN-overexpressing LoVo cells, whereas the opposite pattern was observed in OAS2-overexpressing RKO cells. Patients with low GSN expression had significantly higher 5-year recurrence-free survival (RFS) rates than those with GSN overexpression (73.6% vs. 64.7%, p = 0.038), whereas RFS was longer in patients with OAS2 overexpression than in those with underexpression (73.4% vs. 63.7%, p = 0.01). In conclusion, GSN and OAS2 were positively and negatively associated with recurrence, respectively, suggesting their potential value as predictors of recurrence or therapeutic targets in CRC patients.

PyMT-1099, a versatile murine cell model for EMT in breast cancer

An epithelial-mesenchymal transition (EMT) has been implicated in cancer metastasis, drug resistance, and in conferring stem cell-like traits to cancer cells. Most studies investigating EMT in cancer have either utilized immortalized or cancer cell lines that are already primed to undergo an EMT and do not adequately represent a fully differentiated epithelial state in the absence of an EMT induction. Hence, model systems are required which recapitulate all stages of EMT in cancer cells. Here, we report the derivation and characterization of epithelial PyMT-1099 cancer cells from the MMTV-PyMT mouse model of breast cancer. We demonstrate that PyMT-1099 cells undergo an EMT upon TGFβ treatment, while upon TGFβ withdrawal they go through a mesenchymal-epithelial transition (MET), as assessed by changes in cell morphology and marker expression and comparable to normal murine mammary gland NMuMG cells. However, in contrast to NMuMG cells, PyMT-1099 cells show an increase in cell migration and are highly tumorigenic and metastatic when transplanted into immunocompromised mice. Finally, we report cancer cell-specific changes in gene expression during EMT of PyMT-1099 cells not found in non-transformed NMuMG cells. Thus, PyMT-1099 cells are a versatile tool to study breast cancer-associated EMT and MET in vitro and in vivo.

Flubendazole and mebendazole impair migration and epithelial to mesenchymal transition in oral cell lines

Benzimidazole anthelmintics flubendazole and mebendazole are microtubule-targeting drugs that showed considerable anti-cancer activity in different preclinical models. In this study, the effects of flubendazole and mebendazole on proliferation, migration and cadherin switching were studied in a panel of oral cell lines in vitro. Both compounds reduced the viability of the PE/CA-PJ15 and H376 oral squamous carcinoma cells and of the premalignant oral keratinocytes DOK with the IC₅₀ values in the range of 0.19-0.26 μM. Normal oral keratinocytes and normal gingival fibroblasts were less sensitive to the treatment. Flubendazole and mebendazole also reduced the migration of the PE/CA-PJ15 cell in concentrations that had no anti-migratory effects on the normal gingival fibroblasts. Levels of the focal adhesion kinase FAK, Rho-A and Rac1 GTPases and the Rho guanine nucleotide exchange factor GEF-H1 were decreased in both PE/CA-PJ15 cells and gingival fibroblasts following treatment. Both drugs also interfered with cadherin switching in the model of TGF-β-induced epithelial to mesenchymal transition (EMT) in the DOK cell line. Levels of N-cadherin were reduced in the TGF-β induced cells co-treated with flubendazol and mebendazole in very low concentration (50 nM). These results suggest direct effects of both benzimidazoles on selected processes of EMT in oral cell lines such as cadherin switching as well as cellular migration.

Fibroblast growth factor 18 promotes the growth, migration and invasion of MDA‑MB‑231 cells

Fibroblast growth factor 18 (FGF18) increases cell motility and invasion in colon tumors, and is linked with ovarian and lung tumors. Furthermore, the increased expression of FGF18 mRNA and protein has been associated with poor overall survival in cancer patients. However, its function has not been investigated in breast cancer. In the present study, we demonstrated that FGF18 promoted cell growth and metastasis in vitro and stimulated tumor growth in xenograft models in vivo. FGF18 mediated the proliferation of MDA-MB-231 cells via the ERK/c-Myc signaling pathway and induced epithelial-to-mesenchymal transition (EMT) factors to promote cancer migration and invasion. The decreased expression of FGF18 was strongly correlated with the loss/reduction of p-ERK, c-Myc, N-cadherin, vimentin and Snail 1 protein in MDA-MB-231 cells. Collectively, our results indicated that FGF18 played an important role in the growth and metastasis of breast cancer via the ERK/c-Myc signaling pathway and EMT, indicating that FGF18 may be a potential molecular treatment target for breast cancer.

Significance of PI3K/AKT signaling pathway in metastasis of esophageal squamous cell carcinoma and its potential as a target for anti-metastasis therapy

Metastasis is the most lethal hallmark of esophageal squamous cell carcinoma (ESCC). The aim of the study is to identify key signaling pathways that control metastasis in ESCC. Highly invasive ESCC sublines (designated I3 cells) were established through three rounds of selection of cancer cells invading through matrigel-coated chambers. Gene expression profile of one of the I3 sublines was compared with that of its parental cell line using cDNA microarray analysis. Gene ontology and pathway analyses of the differentially expressed genes (both upregulated and downregulated) indicated that genes associated with cellular movement and the AKT pathway were associated with increased cancer cell invasiveness. Western blot analysis confirmed increased phosphorylated AKT (p-AKT), N-cadherin and decreased E-cadherin expression in the I3 cells. Immunohistochemistry was used to evaluate the clinical significance of p-AKT expression in ESCC, and the results showed higher p-AKT nuclear expression in lymph node metastases when compared with primary carcinoma. Inactivation of the PI3K/AKT pathway with specific inhibitors, or with PTEN overexpression, resulted in reversed cadherin switching and inhibited cancer cell motility. Inhibition of the pathway by treatment with wortmannin markedly suppressed experimental metastasis in nude mice. Our data demonstrated the importance of the PI3K/AKT signaling pathway in ESCC metastasis and support PI3K/AKT as a valid therapeutic target in treatment of metastatic ESCC.

Snail knockdown reverses stemness and inhibits tumour growth in ovarian cancer

To develop effective therapies for advanced high grade serous ovarian cancer (HGSOC), understanding mechanisms of recurrence and metastasis is necessary. In this study, we define the epithelial/mesenchymal status of cell lines that accurately model HGSOC, and evaluate the therapeutic potential of targeting Snai1 (Snail), a master regulator of the epithelial/mesenchymal transition (EMT) in vitro and in vivo. The ratio of Snail to E-cadherin (S/E index) at RNA and protein levels was correlated with mesenchymal morphology in four cell lines. The cell lines with high S/E index (OVCAR8 and COV318) showed more CSC-like, motile, and chemoresistant phenotypes than those with low S/E index (OVSAHO and Kuramochi). We tested the role of Snail in regulation of malignant phenotypes including stemness, cell motility, and chemotherapy resistance: shRNA-mediated knockdown of Snail reversed these malignant phenotypes. Interestingly, the expression of let-7 tumour suppressor miRNA was upregulated in Snail knockdown cells. Furthermore, knockdown of Snail decreased tumour burden in an orthotopic xenograft mouse model. We conclude that Snail is important in controlling HGSOC malignant phenotypes and suggest that the Snail/Let-7 axis may be an attractive target for HGSOC treatment.

Curcumin for the Prevention of Epithelial-Mesenchymal Transition in Endoxifen-Treated MCF-7 Breast Cancer Cel

Background: Curcumin was shown to reduce epithelial-mesenchymal transition (EMT) markers in previous short term studies. This study was aimed to investigate the potential of curcumin in the prevention of EMT activation in MCF-7 cells induced by endoxifen. Methods: MCF-7 breast cancer cells were treated with Endoxifen 1000 nM+betaestradiol 1 nM with or without curcumin (8.5μM or 17 μM). Cells treated with dimethyl sulfoxide (DMSO) 0.001% were used as negative control. After 8 weeks of continuous treatment, the cells were counted, analyzed for mRNA E-cadherin, vimentin, TGF-β expression, total reactive oxygen species (ROS) and observed for morphological changes using confocal microscope and transmission electron microscope. Result: MCF-7 cell viability was increased in endoxifen + β-estradiol group. Cell viability was significantly decreased in curcumin 17 μM, but not in curcumin 8.5 μM group. Analysis of EMT markers at week 8 indicates that there were increase in vimentin and TGF-β mRNA expressions, while E-cadherin mRNA expressions and TGF-β1 protein concentrations were shown to decrease. The results showed that administration of curcumin in all the dose administered were incapable improving the expressions of vimentin, TGF-β1 and E-cadherin. There was a decrease in ROS concentration in curcumin treated cells (8.5 μM) while in curcumin 17 μM, ROS concentration was increased. Morphological observation using confocal microscope and TEM showed the presence of mesenchymal cells and adherens junction. Conclusion: endoxifen treatments for eight weeks resulted in upregulation of EMT markers and changes in morphology of MCF-7 breast cancer cells. The addition of curcumin did not prevent the activation of EMT.

A kinome-wide high-content siRNA screen identifies MEK5-ERK5 signaling as critical for breast cancer cell EMT and metastasis

An epithelial to mesenchymal transition (EMT) has been correlated to malignant tumor progression and metastasis by promoting cancer cell migration and invasion and chemoresistance. Hence, finding druggable EMT effectors is critical to efficiently interfere with metastasis formation and to overcome therapy resistance. We have employed a high-content microscopy screen in combination with a kinome and phosphatome-wide siRNA library to identify signaling pathways underlying an EMT of murine mammary epithelial cells and breast cancer cells. This screen identified the MEK5-ERK5 axis as a critical player in TGFβ-mediated EMT. Suppression of MEK5-ERK5 signaling completely prevented the morphological and molecular changes occurring during a TGFβ-induced EMT and, conversely, forced highly metastatic breast cancer cells into a differentiated epithelial state. Inhibition of MEK5-ERK5 signaling also repressed breast cancer cell migration and invasion and substantially reduced lung metastasis without affecting primary tumor growth. The results suggest that the MEK5-ERK5 signaling axis via activation of MEF2B and other transcription factors plays an important role in the induction and maintenance of breast cancer cell migration and invasion and thus represents an exploitable target for the pharmacological inhibition of cancer cell metastasis.

βKlotho inhibits androgen/androgen receptor‑associated epithelial‑mesenchymal transition in prostate cancer through inactivation of ERK1/2 signaling

The epithelial-mesenchymal transition (EMT) is reported to have intimate crosstalk with androgen receptor (AR) signaling in prostate cancer (PCa) and is known to be responsible for castration resistance. Fibroblast growth factor/receptor (FGF/FGFR) signaling is also involved in tumor progression and EMT in multiple tissues. Several studies have investigated the role of βKlotho, an FGF/FGFR signaling co-receptor in tumorigenesis. However, its role in PCa remains unknown. In the present study, the role of androgen in the EMT of PCa cells was examined by western blotting. The expression of βKlotho was examined in prostate cells and PCa tissues by western blotting and immunohistochemistry, respectively. The biological role of βKlotho was revealed by a series of functional in vitro and in vivo studies. We determined that βKlotho expression was significantly decreased in PCa tissues compared with benign prostatic hyperplasia (BPH) tissues, and low βKlotho expression was associated with a high Gleason score of PCa. βKlotho overexpression inhibited the viability, migration, and androgen/AR-associated EMT of PCa cells through the inactivation of ERK1/2 signaling. Notably, βKlotho overexpression inhibited prostate tumor growth and EMT in vivo. Knockdown of βKlotho produced the opposite effects. In conclusion, βKlotho inhibits EMT and plays a tumor-suppressive role in PCa, linking FGF/FGFR/βKlotho signaling to the regulation of PCa progression.

ERK signalling modulates epigenome to drive epithelial to mesenchymal transition

The series of events that allow the conversion from adherent epithelial cells into migratory cells is collectively known as epithelial-mesenchymal transition (EMT). EMT is employed during embryonic development such as for gastrulation and neural crest migration and is misused in diseases, such as cancer metastasis. ERK signalling is known to be essential for EMT, however its influence on the epigenetic and transcriptional programme underlying EMT is poorly understood. Here, using a comprehensive genome-wide analysis of H3K27ac mark and gene expression in mammary epithelial cells undergoing EMT, we found that ERK signalling is essential for the epigenetic reprogramming underlying hallmark gene expression and phenotypic changes of EMT. We show that the chemical inhibition of Erk signalling during EMT prevents the loss and gain of the H3K27ac mark at regulatory regions of epithelial and mesenchymal genes, respectively, and results in a transcriptome and epigenome closer to those of epithelial cells. Further computational analyses identified a distinct set of transcription factor motifs enriched at distal regulatory regions that are epigenetically remodelled by ERK signalling. Altogether, our findings reveal an ERK-dependent epigenetic remodelling of regulatory elements that results in a gene expression programme essential for driving EMT.

An Adaptogen: Withaferin A Ameliorates in Vitro and in Vivo Pulmonary Fibrosis by Modulating the Interplay of Fibrotic, Matricelluar Proteins, and Cytokines

Pulmonary fibrosis (PF) is chronic lung disease with only two FDA approved clinically available drugs, with limited safety profile. Inadequate therapy motivated us to explore the effect of vimentin inhibitor Withaferin A, as an anti-fibrotic agent against TGF-β1-induced in vitro fibrotic events and Bleomycin induced in vivo fibrosis with an emphasis on epithelial to mesenchymal transition (EMT), extracellular matrix deposition (ECM), inflammation, and angiogenesis. In vitro EMT and fibrotic events were induced by TGF-β1 in alveolar epithelial cells and human fetal lung fibroblasts followed by treatment with Withaferin A (0.25, 0.5, and 1 μM concentrations) to explore its anti-fibrotic effects. In vivo potential of Withaferin A (2 and 4 mg/kg) was assessed in murine model of Bleomycin induced PF. All the parameters and molecular studies related to PF were performed at the end of treatment period. Withaferin A treatment reduced the progression of PF by modulating the EMT related cell markers both in vivo and in vitro. Withaferin A ameliorated the expression of inflammatory cytokines including NF-κB p65, IL-1β and TNF-α, as well as attenuated the expression of pro-fibrotic proteins including CTGF, collagen 1A2, collagen 3A1, and fibronectin. Expression of angiogenic factors like VEGF, FAK, p38 MAPK, and PLC-γ1 were also inhibited by Withaferin A. Phosphorylation of Smad 2/3 induced by TGF-β1 and Bleomycin were significantly inhibited. Withaferin A suppressed expression of pro-inflammatory, pro-fibrotic, and pro-angiogenic mediators and also reduced the ECM deposition. In a nutshell, Withaferin A could probably prove as an efficient and potential therapeutic against PF.

A high-content EMT screen identifies multiple receptor tyrosine kinase inhibitors with activity on TGFβ receptor

An epithelial to mesenchymal transition (EMT) enables epithelial tumor cells to break out of the primary tumor mass and to metastasize. Understanding the molecular mechanisms driving EMT in more detail will provide important tools to interfere with the metastatic process. To identify pharmacological modulators and druggable targets of EMT, we have established a novel multi-parameter, high-content, microscopy-based assay and screened chemical compounds with activities against known targets. Out of 3423 compounds, we have identified 19 drugs that block transforming growth factor beta (TGFβ)-induced EMT in normal murine mammary gland epithelial cells (NMuMG). The active compounds include inhibitors against TGFβ receptors (TGFBR), Rho-associated protein kinases (ROCK), myosin II, SRC kinase and uridine analogues. Among the EMT-repressing compounds, we identified a group of inhibitors targeting multiple receptor tyrosine kinases, and biochemical profiling of these multi-kinase inhibitors reveals TGFBR as a thus far unknown target of their inhibitory spectrum. These findings demonstrate the feasibility of a multi-parameter, high-content microscopy screen to identify modulators and druggable targets of EMT. Moreover, the newly discovered "off-target" effects of several receptor tyrosine kinase inhibitors have important consequences for in vitro and in vivo studies and might beneficially contribute to the therapeutic effects observed in vivo.

Splicing factor ratio as an index of epithelial-mesenchymal transition and tumor aggressiveness in breast cancer

Epithelial-to-mesenchymal transition (EMT) has been shown to be associated with tumor progression and metastasis. During this process in breast cancer, a crucial role is played by alternative splicing systems. To identify a new early prognostic marker of metastasis, we evaluated EMT-related gene expression in breast cell lines, and in primary tumor tissue from 31 patients with early breast cancer, focusing our attention on EMT-related splicing factors ESRP1, ESRP2 and RBFOX2. Results showed that the expression patterns of these genes were indicative of the onset of EMT in in-vitro models, but not in tissue samples. However, the ratio between ESRP1 or ESRP2 and RBFOX2 significantly decreased during EMT and positively correlated with the EMT-specific phenotype in cell models, representing a promising prognostic markers. Low ESRP1/RBFOX2 ratio value was associated with a higher risk of metastasis (p < 0.005) in early breast cancer patients, regardless other clinical features. A cut-off of ratio of 1.067 was determined by ROC curve analysis (AUC 0.8375; 95% CI 0.6963-0.9787). Our study show evidence that a decrease in this ratio correlates with cancer progression. The results provide a rationale for using ESRP1/RBFOX2 ratio as a new prognostic biomarker for the early prediction of metastatic potential in breast cancer.

A novel highly potent trivalent TGF-β receptor trap inhibits early-stage tumorigenesis and tumor cell invasion in murine Pten-deficient prostate glands

The effects of transforming growth factor beta (TGF-β) signaling on prostate tumorigenesis has been shown to be strongly dependent on the stage of development, with TGF-β functioning as a tumor suppressor in early stages of disease and as a promoter in later stages. To study in further detail the paradoxical tumor-suppressive and tumor-promoting roles of the TGF-β pathway, we investigated the effect of systemic treatment with a TGF-β inhibitor on early stages of prostate tumorigenesis. To ensure effective inhibition, we developed and employed a novel trivalent TGF-β receptor trap, RER, comprised of domains derived from the TGF-β type II and type III receptors. This trap was shown to completely block TβRII binding, to antagonize TGF-β1 and TGF-β3 signaling in cultured epithelial cells at low picomolar concentrations, and it showed equal or better anti-TGF-β activities than a pan TGF-β neutralizing antibody and a TGF-β receptor I kinase inhibitor in various prostate cancer cell lines. Systemic administration of RER inhibited prostate tumor cell proliferation as indicated by reduced Ki67 positive cells and invasion potential of tumor cells in high grade prostatic intraepithelial neoplasia (PIN) lesions in the prostate glands of Pten conditional null mice. These results provide evidence that TGF-β acts as a promoter rather than a suppressor in the relatively early stages of this spontaneous prostate tumorigenesis model. Thus, inhibition of TGF-β signaling in early stages of prostate cancer may be a novel therapeutic strategy to inhibit the progression as well as the metastatic potential in patients with prostate cancer.

Transcriptional Analysis Reveals Evidence of Chronically Impeded ECM Turnover and Epithelium-to-Mesenchyme Transition in Scar Tissue Giving Rise to Marjolin's Ulcer

Marjolin's ulcer (MU) is an aggressive malignancy arising within chronic wounds. A major cause is unhealed burn injuries. This results in well-differentiated squamous cell carcinoma (SCC). This study aimed to elucidate transcriptional changes leading to malignancy by investigating differentially expressed genes in squamous cells present in a SCC compared with MU. MU tumor cells were isolated from histologically confirmed biopsy of SCC within an unhealed burn scar. Epithelial cells (ECs) adjacent to the tumor were co-isolated and a SCC cell line was commercially purchased. mRNA from all three samples was isolated and its expression was quantified using RNASeq. A threshold of log2fold change >2-fold in either direction was considered "differentially expressed." Gene expression analysis revealed distinct differences in gene expression in MU cells compared with EC (665 genes), EC and SCC (1673 genes). Enrichment analysis confirmed that pathways most affected included 1) elevation of genes associated with extracellular matrix organization/degradation, 2) activation of DNA damage, and 3) activation of cytokine signaling. Our analysis revealed two key insights about chronic wound microenvironment conducive to ulceration. First, in EC vs. MU comparison, downregulation of Collagen and Matrix metalloproteinase families suggests chronically impaired extracellular matrix turnover giving rise to a fibrotic microenvironment. Second, in SCC vs. MU comparison, dysregulation of cadherin-mediated cell-cell adhesions is suggestive of epithelial-to-mesenchymal transitions, similar to those during development. Acquisition of epithelial-to-mesenchymal transition may underlie the high metastatic rate in MU tumors. Taken together, this sheds light on mechanisms that underlie the divergent clinical features of these cutaneous cancers.

Shikonin induces mitochondria-mediated apoptosis and attenuates epithelial-mesenchymal transition in cisplatin-resistant human ovarian cancer cells

Cisplatin-based chemotherapy often results in the development of chemoresistance when used to treat ovarian cancer, which is difficult to overcome. The present study investigated the cytotoxic and anti-migratory effects of shikonin, a naphthoquinone compound, on cisplatin-resistant human ovarian cancer A2780 cells (A2780-CR). Shikonin had a potent dose-dependent cytotoxic effect on A2780-CR cells, with 9 µM shikonin treatment reducing A2780-CR cell viability by 50%, validate using an MTT assay. Shikonin induced apoptosis, as evidenced by the increased number of apoptotic bodies, following staining with Hoechst 33342, and terminal deoxynucleotidyl cell transferase dUTP nick end labeling-positive cells following treatment. Flow cytometry and fluorescent microscope imaging, following JC-1 staining, revealed that shikonin increased mitochondrial membrane depolarization. Also it altered the levels of apoptosis-associated proteins, leading to diminished expression of B cell lymphoma-2 (Bcl-2), enhanced expression of Bcl-associated X, and cleavage of caspase-9 and −3, as revealed using western blot analysis. Shikonin activated mitogen-activated protein kinases; while treatment with specific inhibitors of these kinases attenuated the decline in cell viability induced by shikonin treatment. In addition, the cell migration assay and western blot analysis indicated that shikonin decreased the migratory capacity of A2780-CR cells via the upregulation of epithelial-cadherin and downregulation of neural-cadherin. Taken together, the results of the present study indicated that shikonin induces mitochondria-mediated apoptosis and attenuates the epithelial-mesenchymal transition in A2780-CR cells.

Metformin inhibits 17β-estradiol-induced epithelial-to-mesenchymal transition via βKlotho-related ERK1/2 signaling and AMPKα signaling in endometrial adenocarcinoma cells

The potential role of metformin in treating endometrial cancer remains to be explored. The current study investigated the role of metformin in 17β-estradiol-induced epithelial-mesenchymal transition (EMT) in endometrial adenocarcinoma cells. We found that 17β-estradiol promoted proliferation and migration, attenuated apoptosis in both estrogen receptor (ER) positive and ER negative endometrial adenocarcinoma cells (Ishikawa and KLE cells, respectively). Metformin abolished 17β-estradiol-induced cell proliferation and reversed 17β-estradiol-induced EMT in Ishikawa cells. In addition, metformin increased the expression of βKlotho, a fibroblast growth factors (FGFs) coreceptor, and decreased ERK1/2 phosphorylation in both Ishikawa and KLE cells. Decreased expression of βKlotho was noted in human endometrial adenocarcinomas, and plasmid-driven expression of βKlotho in Ishikawa cells abolished 17β-estradiol-induced EMT via inhibiting ERK1/2 signaling. βKlotho expression and metformin show synergetic effects on the proliferation and the EMT in Ishikawa cells. Furthermore, we demonstrated that the anti-EMT effects of metformin could be partly abolished by introducing Compound C, a specific AMPKα signaling inhibitor. In conclusion, metformin abolishes 17β-estradiol-induced cell proliferation and EMT in endometrial adenocarcinoma cells by upregulating βKlotho expression, inhibiting ERK1/2 signaling, and activating AMPKα signaling. Our study provides novel mechanistic insight into the anti-tumor effects of metformin.

Systems Biology Approach and Mathematical Modeling for Analyzing Phase-Space Switch During Epithelial-Mesenchymal Transition

In this report, we aim at presenting a viable strategy for the study of Epithelial-Mesenchymal Transition (EMT) and its opposite Mesenchymal-Epithelial Transition (MET) by means of a Systems Biology approach combined with a suitable Mathematical Modeling analysis. Precisely, it is shown how the presence of a metastable state, that is identified at a mesoscopic level of description, is crucial for making possible the appearance of a phase transition mechanism in the framework of fast-slow dynamics for Ordinary Differential Equations (ODEs).

3D cellular structures and co-cultures formed through the contactless magnetic manipulation of cells on adherent surfaces

Label-free cell magnetic manipulations facilitate fast and new experimental setups and reveal novel observations in synthetic biology.

Expression of insulin-like growth factor-1 receptor in circulating tumor cells of patients with breast cancer is associated with patient outcomes

In patients with breast cancer, markers of aggressiveness such as dysregulation of the insulin-like growth factor receptor (IGF1R) system and E-cadherin loss are commonly observed. Reduced IGF1R expression is correlated with decreased E-cadherin levels and increased cell motility. We assessed IGF1R and E-cadherin expression in circulating tumor cells (CTCs) in patients with breast cancer. Peripheral blood mononuclear cells of early (n = 87)- and metastatic (n = 126)-stage breast cancer patients (obtained prior to adjuvant and first-line chemotherapy) were evaluated using double immunofluorescence (IF) staining for cytokeratin (CK) and IGF1R. Triple IF using CK, IGF1R, and E-cadherin antibodies was performed in selected CTC(+) patients. IGF1R(+) CTCs were more frequently observed in early disease than in metastatic disease (86% vs 68% of CTCs, P = 0.04) stage, whereas IGF1R(-) CTCs were more common in metastatic than in early disease (32% vs 14% of CTCs, P = 0.002). 100% of CTC(+) patients with early disease, compared to 79% of those with metastatic disease, harbored IGF1R(+) CTCs (P = 0.007). Patients with early disease and exclusively IGF1R(+) CTCs had longer disease-free (P = 0.02) and overall survival (P = 0.001) compared to patients with both IGF1R(+) and IGF1R(-) CTC populations. 67% of early-stage CTC(+) patients evaluated had exclusively IGF1R(+)/E-cadherin(+) CTCs, 33% also had IGF1R(-)/E-cadherin(-) CTCs, and none had exclusively IGF1R(-)/E-cadherin(-) CTCs compared to 17%, 75%, and 8% of metastatic patients, respectively (P = 0.027). Similarly, in paired samples of patients with early disease that progressed to metastatic disease, the proportion of IGF1R(+)/E-cadherin(+) CTCs was reduced and IGF1R(-)/E-cadherin(-) CTCs were increased in the metastatic stage compared to early disease stage. IGF1R(+) CTCs are commonly detected in breast cancer, and their frequency decreases in the metastatic disease stage. IGF1R(+)/E-cadherin(+) CTCs also decrease in metastatic patients. IGF1R(+) CTCs are associated with favorable outcomes in early disease stage, suggesting that IGF1R expression is correlated with reduced metastatic potential in breast cancer.

FBXO32 promotes microenvironment underlying epithelial-mesenchymal transition via CtBP1 during tumour metastasis and brain development

The set of events that convert adherent epithelial cells into migratory cells are collectively known as epithelial–mesenchymal transition (EMT). EMT is involved during development, for example, in triggering neural crest migration, and in pathogenesis such as metastasis. Here we discover FBXO32, an E3 ubiquitin ligase, to be critical for hallmark gene expression and phenotypic changes underlying EMT. Interestingly, FBXO32 directly ubiquitinates CtBP1, which is required for its stability and nuclear retention. This is essential for epigenetic remodeling and transcriptional induction of CtBP1 target genes, which create a suitable microenvironment for EMT progression. FBXO32 is also amplified in metastatic cancers and its depletion in a NSG mouse xenograft model inhibits tumor growth and metastasis. In addition, FBXO32 is essential for neuronal EMT during brain development. Together, these findings establish that FBXO32 acts as an upstream regulator of EMT by governing the gene expression program underlying this process during development and disease.

Epithelial-to-mesenchymal transition (EMT) regulates both processes of organism development and changes in cell state causing disease. Here, the authors show that an E3 ubiquitin ligase, FBXO32, regulates EMT via CtBP1 and the transcriptional program, and also mediates cancer metastatic burden and neurogenesis.

miR-1199-5p and Zeb1 function in a double-negative feedback loop potentially coordinating EMT and tumour metastasis

Epithelial tumour cells can gain invasive and metastatic capabilities by undergoing an epithelial–mesenchymal transition. Transcriptional regulators and post-transcriptional effectors like microRNAs orchestrate this process of high cellular plasticity and its malignant consequences. Here, using microRNA sequencing in a time-resolved manner and functional validation, we have identified microRNAs that are critical for the regulation of an epithelial–mesenchymal transition and of mesenchymal tumour cell migration. We report that miR-1199-5p is downregulated in its expression during an epithelial–mesenchymal transition, while its forced expression prevents an epithelial–mesenchymal transition, tumour cell migration and invasion in vitro, and lung metastasis in vivo. Mechanistically, miR-1199-5p acts in a reciprocal double-negative feedback loop with the epithelial–mesenchymal transition transcription factor Zeb1. This function resembles the activities of miR-200 family members, guardians of an epithelial cell phenotype. However, miR-1199-5p and miR-200 family members share only six target genes, indicating that, besides regulating Zeb1 expression, they exert distinct functions during an epithelial–mesenchymal transition.

miRNAs have been involved in tumour development and progression. Here the authors uncover a double feedback loop between miR-1199-5p and the Zeb1, potentially coordinating a protein involved in epithelial mesenchymal transition and tumour metastasis.

Analysis of Contractility and Invasion Potential of Two Canine Mammary Tumor Cell Lines

Cancer cells are surrounded by a mechanically and biochemically distinct microenvironment that undergoes dynamic changes throughout the neoplastic progression. During this progression, some cancer cells acquire abnormal characteristics that potentiate their escape from the primary tumor site, to establish secondary tumors in distant organs. Recent studies with several human cancer cell lines have shown that the altered physical properties of tumor cells, such as their ability to apply high traction forces to the surroundings, are directly linked with their potential to invade and metastasize. To test the hypothetical interconnection between actomyosin-mediated traction forces and invasion potential within 3D-microenvironment, we utilized two canine mammary tumor cell lines with different contractile properties. These cell lines, canine mammary tumor (CMT)-U27 and CMT-U309, were found to have distinct expression patterns of lineage-specific markers and organization of actin-based structures. In particular, CMT-U309 carcinoma cells were typified by thick contractile actomyosin bundles that exerted high forces to their environment, as measured by traction force microscopy. These high contractile forces also correlated with the prominent invasiveness of the CMT-U309 cell line. Furthermore, we found high contractility and 3D-invasion potential to be dependent on the activity of 5′AMP-activated protein kinase (AMPK), as blocking AMPK signaling was found to reverse both of these features. Taken together, our findings implicate that actomyosin forces correlate with the invasion potential of the studied cell lines.

Oxygen-dependent regulation of tumor growth and metastasis in human breast cancer xenografts

Background

Tumor hypoxia is relevant for tumor growth, metabolism, resistance to chemotherapy and metastasis. We have previously shown that hyperoxia, using hyperbaric oxygen treatment (HBOT), attenuates tumor growth and shifts the phenotype from mesenchymal to epithelial (MET) in the DMBA-induced mammary tumor model. This study describes the effect of HBOT on tumor growth, angiogenesis, chemotherapy efficacy and metastasis in a triple negative MDA-MB-231 breast cancer model, and evaluates tumor growth using a triple positive BT-474 breast cancer model.

Materials and methods

5 x 10⁵ cancer cells were injected s.c. in the groin area of NOD/SCID female mice. The BT-474 group was supplied with Progesterone and Estradiol pellets 2-days prior to tumor cell injection. Mice were divided into controls (1 bar, pO₂ = 0.2 bar) or HBOT (2.5 bar, pO₂ = 2.5 bar, 90 min, every third day until termination of the experiments). Treatment effects were determined by assessment of tumor growth, proliferation (Ki67-staining), angiogenesis (CD31-staining), metastasis (immunostaining), EMT markers (western blot), stromal components collagen type I, Itgb1 and FSP1 (immunostaining) and chemotherapeutic efficacy (5FU).

Results

HBOT significantly suppressed tumor growth in both the triple positive and negative tumors, and both MDA-MB-231 and BT-474 showed a decrease in proliferation after HBOT. No differences were found in angiogenesis or 5FU efficacy between HBOT and controls. Nevertheless, HBOT significantly reduced both numbers and total area of the metastastatic lesions, as well as reduced expression of N-cadherin, Axl and collagen type I measured in the MDA-MB-231 model. No change in stromal Itgb1 and FSP1 was found in either tumor model.

Conclusion

Despite the fact that behavior and prognosis of the triple positive and negative subtypes of cancer are different, the HBOT had a similar suppressive effect on tumor growth, indicating that they share a common oxygen dependent anti-tumor mechanism. Furthermore, HBOT significantly reduced the number and area of metastatic lesions in the triple negative model as well as a significant reduction in the EMT markers N-cadherin, Axl and density of collagen type I.