Targeting EMT in cancer: opportunities for pharmacological intervention

Zinc regulates primary ovarian tumor growth and metastasis through the epithelial to mesenchymal transition

BACKGROUND

The trace element zinc plays an indispensable role in human health and diseases including cancer due to its antioxidant properties. While zinc supplements have been used for cancer prevention, zinc is also a risk factor for cancer development. It is still unclear how zinc plays a role in ovarian cancer.

METHODS

To understand how zinc contributes to ovarian tumor growth and metastasis, we examined whether zinc contributes to tumor metastasis by regulating epithelial to mesenchymal transition (EMT) using ovarian cancer cells in vitro. Cell migration and invasion were examined using transwell plates and EMT markers were examined using Western blot. Primary ovarian tumor growth and metastasis were assessed using orthotopic ovarian cancer mouse models in vivo.

RESULTS

Zinc promoted EMT, while TPEN (N, N, N', N'-tetrakis-(2-pyridylmethyl)-ethylenediamine), a membrane-permeable selective zinc chelator, inhibited EMT in a dose dependent manner in ovarian cancer cells. Moreover, zinc promoted ovarian cancer cell migration and invasion, while TPEN inhibited cell migration and invasion. Zinc activated expression of the metal response transcriptional factor-1 (MTF-1), while TPEN inhibited MTF-1 expression in a dose dependent manner. Knockout of MTF-1 inhibited zinc-induced cell migration, invasion and augmented the inhibitory effect of TPEN on cell migration and invasion. Loss of MTF-1 attenuated zinc-induced ERK1/2 and AKT activation and augmented the effect of TPEN in attenuating the ERK1/2 and AKT pathways. TPEN effectively inhibited primary ovarian tumor growth and metastasis in an orthotopic ovarian cancer mouse model by suppressing EMT.

CONCLUSION

zinc contributes to ovarian tumor metastasis by promoting EMT through a MTF-1 dependent pathway. Zinc depletion by TPEN may be a novel approach for ovarian cancer therapy by inhibiting EMT and attenuating the ERK1/2 and AKT pathways.

Xenograft-based, platform-independent gene signatures to predict response to alkylating chemotherapy, radiation, and combination therapy for glioblastoma

BACKGROUND

Predictive molecular biomarkers to select optimal treatment for patients with glioblastoma and other cancers are lacking. New strategies are needed when large randomized trials with correlative molecular data are not feasible.

METHODS

Gene signatures (GS) were developed from 31 orthotopic glioblastoma patient-derived xenografts (PDXs), treated with standard therapies, to predict benefit from radiotherapy (RT-GS), temozolomide (Chemo-GS), or the combination (ChemoRT-GS). Independent validation was performed in a heterogeneously treated clinical cohort of 502 glioblastoma patients with overall survival as the primary endpoint. Multivariate Cox analysis was used to adjust for confounding variables and evaluate interactions between signatures and treatment.

RESULTS

PDX models recapitulated the clinical heterogeneity of glioblastoma patients. RT-GS, Chemo-GS, and ChemoRT-GS were correlated with benefit from treatment in the PDX models. In independent clinical validation, higher RT-GS scores were associated with increased survival only in patients receiving RT (P = 0.0031, hazard ratio [HR] = 0.78 [0.66-0.92]), higher Chemo-GS scores were associated with increased survival only in patients receiving chemotherapy (P < 0.0001, HR = 0.66 [0.55-0.8]), and higher ChemoRT-GS scores were associated with increased survival only in patients receiving ChemoRT (P = 0.0001, HR = 0.54 [0.4-0.74]). RT-GS and ChemoRT-GS had significant interactions with treatment on multivariate analysis (P = 0.0009 and 0.02, respectively), indicating that they are bona fide predictive biomarkers.

CONCLUSIONS

Using a novel PDX-driven methodology, we developed and validated 3 platform-independent molecular signatures that predict benefit from standard of care therapies for glioblastoma. These signatures may be useful to personalize glioblastoma treatment in the clinic and this approach may be a generalizable method to identify predictive biomarkers without resource-intensive randomized trials.

Decoding cancer's camouflage: epithelial-mesenchymal plasticity in resistance to immune checkpoint blockade

Epithelial-mesenchymal plasticity (EMP) of cancer cells contributes to cancer cell heterogeneity, and it is well established that EMP is a critical determinant of acquired resistance to cancer treatment modalities including radiation therapy, chemotherapy, and targeted therapies. Here, we aimed to explore how EMP contributes to cancer cell camouflage, allowing an ever-changing population of cancer cells to pass under the radar of our immune system and consequently compromise the effect of immune checkpoint blockade therapies. The ultimate clinical benefit of any combination regimen is evidenced by the sum of the drug-induced alterations observed in the variety of cellular populations composing the tumor immune microenvironment. The finely-tuned molecular crosstalk between cancer and immune cells remains to be fully elucidated, particularly for the spectrum of malignant cells along the epithelial to mesenchymal axis. High-dimensional single cell analyses of specimens collected in ongoing clinical studies is becoming a key contributor to our understanding of these interactions. This review will explore to what extent targeting EMP in combination with immune checkpoint inhibition represents a promising therapeutic avenue within the overarching strategy to reactivate a halting cancer-immunity cycle and establish a robust host immune response against cancer cells. Therapeutic strategies currently in clinical development will be discussed.

Current perspectives on the dysregulated microRNAs in gastric cancer

Since gastric cancer (GC) is diagnosed at advanced stages, the survival rate is low in affected people. In this regard, investigating the mechanisms underlying GC development, are so critical. MiRNAs, which are small non coding RNAs, as a post transcriptional repressor, regulate expression of target genes by stimulating breakage or transcription suppression of their targets therefore aberrant expression of miRNAs leading to GC carcinogenesis. In the last decades, there have been various studies approving the pivotal role of miRNAs in various phases of GC development including cancer initiation, proliferation, migration, invasion, metastasis, angiogenesis, apoptosis, and drug resistance. Therefore, the present review aimed at summarizing the dysregulated miRNAs which contribute to various cellular and developmental mechanisms such as, proliferation, apoptosis, invasion, migration, and angiogenesis. Moreover, it provides an overview on novel miRNAs involved in drug resistance and circular miRNAs as cancer biomarkers. Thereafter, it is hoped that the present study will shed more light on diagnostic and prognostic biomarkers of GC, and potential GC treatments based on miRNAs.

Natural alkaloid 8-oxo-epiberberine inhibited TGF-β1-triggred epithelial-mesenchymal transition by interfering Smad3

Epithelial-mesenchymal transition (EMT), the transition of epithelial cells into mesenchymal cells, plays important roles in the metastasis of solid tumors. 8-Oxo-epiberberine (OPB) is a natural alkaloid extracted from the roots of Coptis chinensis Franch. In this study, The effect and the underlying mechanism of OPB on EMT in a TGF-β1-induced model and the inhibitory effect of OPB on lung metastasis were investigated. TGF-β1-stimulated lung cancer cells were co-treated with OPB, the morphological changes were examined. The protein expression of EMT biomarkers E-cadherin and N-cadherin was determined by Western blotting and immunofluorescence. The transcription activity of smad2/3 promoter was analyzed by a luciferase reporter assay. The effect of OPB on cell migration, invasion, and adhesion was detected by wound-healing, adhesion, and transwell assays. The in vivo anti-metastatic effect of OPB was evaluated using a 4 T1 cell xenograft mouse model. Results showed that OPB significantly reversed TGF-β1-triggered morphological changes, expression of EMT biomarkers, and migration, adhesion, and invasion. Furthermore, OPB suppressed TGF-β1-induced Smad2/3 activation, Smad3 phosphorylation and nuclear translocation, and interaction of Smad3 with Smad4. Besides, OPB dramatically decreased the metastatic nodules in the lung without affecting the growth of primary tumors. In conclusion, OPB inhibited TGF-β1-induced EMT possibly by interfering with Smad3. OPB might have therapeutic potentials for the treatment of metastatic cancers.

Drug resistance in cancer: mechanisms and tackling strategies

Drug resistance developed towards conventional therapy is one of the important reasons for chemotherapy failure in cancer. The various underlying mechanism for drug resistance development in tumor includes tumor heterogeneity, some cellular levels changes, genetic factors, and others novel mechanisms which have been highlighted in the past few years. In the present scenario, researchers have to focus on these novel mechanisms and their tackling strategies. The small molecules, peptides, and nanotherapeutics have emerged to overcome the drug resistance in cancer. The drug delivery systems with targeting moiety enhance the site-specificity, receptor-mediated endocytosis, and increase the drug concentration inside the cells, thus minimizing drug resistance and improve their therapeutic efficacy. These therapeutic approaches work by modulating the different pathways responsible for drug resistance. This review focuses on the different mechanisms of drug resistance and the recent advancements in therapeutic approaches to improve the sensitivity and effectiveness of chemotherapeutics.

circ_KIAA1429 accelerates hepatocellular carcinoma advancement through the mechanism of m6A-YTHDF3-Zeb1

AIMS

Hepatocellular carcinoma (HCC), one of the most common cancer, causes the fourth cancer-related deaths around the world. N6-methyladenosine (m⁶A) has been reported to mediate circRNA translation in cancer biology. However, the mechanisms by which m⁶A and circRNA in post-transcriptional in HCC progression remain poorly understood. This study aimed to explore the mechanisms by which m⁶A and circRNA in post-transcriptional in HCC progression.

MAIN METHODS

circ_KIAA1429 (hsa_circ_0084922) expression profiles in matched normal and HCC tissues were detected using microarray analysis. The biological roles of circ_KIAA1429 in progression of HCCC were measured both in vitro and in vivo.

KEY FINDINGS

In this study, we found hsa_circ_0084922, which came from KIAA1429, named circ_KIAA1429, was upregulated in HCC cells and tumor tissues. Overexpression of circ_KIAA1429 can facilitate HCC migration, invasion, and EMT process. However, knockdown of circ_KIAA1429 lead to the opposite results. Furthermore, it was demonstrated that Zeb1 was the downstream target of circ_KIAA1429. Up-regulation of Zeb1 led to HCC cells metastasis induced by circ_KIAA1429. In addition, YTHDF3 enhanced Zeb1 mRNA stability via an m⁶A dependent manner.

SIGNIFICANCE

This study revealed that circ_KIAA1429 could accelerate HCC advancement, maintained the expression of Zeb1 through the mechanism of m⁶A-YTHDF3-Zeb1 in HCC. What's more, it might represent a potential therapeutic target in HCC.

PFND1 Predicts Poor Prognosis of Gastric Cancer and Promotes Cell Metastasis by Activating the Wnt/β-Catenin Pathway

Background

Prefoldin (PFDN) subunits have recently been found to function importantly in various tumor types, while the role of PFDN subunit 1 (PFDN1) in gastric cancer (GC) remains largely unknown. Herein, we aimed to investigate the clinical significance, the biological role and the underlying mechanism of PFDN1 in GC development.

Materials and Methods

PFDN1 expression levels were measured in human GC specimens by quantitative real-time PCR (qRT-PCR), Western blot and immunohistochemistry. Furthermore, the effects of aberrant PFDN1 expression on GC cells behavior were assessed by wound-healing assay and transwell assay in vitro, and metastasis assay in nude mice, as well as Wnt/β-catenin signaling-induced epithelial-mesenchymal transition (EMT)-related markers by qRT-PCR and Western blot.

Results

PFDN1 levels were significantly upregulated in GC tissues compared with those in matched adjacent normal tissues. PFDN1 upregulation correlated strongly with clinical metastasis and unfavorable prognosis for GC patients. In vitro and in vivo studies revealed that PFDN1 facilitated GC cell migration, invasion and metastasis. Mechanically, PFDN1 modulated GC cell behavior by activating Wnt/β-catenin signaling-mediated EMT.

Conclusion

These results suggested a central role of PFDN1 in GC metastatic development via the Wnt/β-catenin pathway, thus providing a potential therapeutic target for patients with GC.

20(S)-ginsenoside Rh2 as agent for the treatment of LMN-CRC via regulating epithelial-mesenchymal transition

The lymph node metastasis of colorectal cancer (LMN-CRC) seriously threatens the prognosis of patients. Chemotherapy, as the most common treatment, results in severe bone marrow suppression. 20(S)-ginsenoside Rh2 (SGRh2), a major effective constituent of ginseng, has demonstrated therapeutic effects on a variety of diseases, including some tumours. SGRh2 treatment had no effect on other organs. Therefore, ginsenosides are considered a safe and effective antineoplastic drug. However, the effects of SGRh2 on LMN-CRC remain unknown. The present study investigated the potential effect of SGRh2 on LMN-CRC in vitro and in vivo. SW480 and CoLo205 cell lines were treated with SGRh2. SGRh2 dose-dependently decreased CRC cell proliferation by CCK-8, colony formation and Edu assays. The Transwell and scratch assays revealed that SGRh2 inhibits the migratory and invasive abilities of CRC cells in a dose-dependent manner. Furthermore, the results of Western blotting revealed that SGRh2 decreased the expression of matrix metalloproteinase (MMP)-2 and MMP9. In terms of the underlying mechanisms, SGRh2 regulates CRC metastasis by affecting epithelial-mesenchymal transition (EMT), which significantly up-regulated epithelial biomarkers (E-cadherin) and down-regulated mesenchymal biomarkers (N-cadherin and vimentin) and EMT transcriptional factors (Smad-3, Snail-1, and Twist-1). In vivo, SGRh2 significantly inhibited LMN-CRC without affecting other normal organs. Immunohistochemical results showed that SGRh2 treats LMN-CRC by regulating EMT. These results demonstrate that SGRh2 has therapeutic potential for LMN-CRC.

Interleukin-33-nuclear factor-κB-CCL2 signaling pathway promotes progression of esophageal squamous cell carcinoma by directing regulatory T cells

Esophageal cancer is currently one of the most fatal cancers. However, there is no effective treatment. Increasing evidence suggests that interleukin (IL)-33 has a significant role in tumor progression and metastasis. Currently, the underlying cellular and molecular mechanism of IL-33 in promoting esophageal squamous cell carcinoma (ESCC) remains unclear. In this study, we investigated whether IL-33 could induce the epithelial-mesenchymal transition (EMT) in ESCC. Interleukin-33 expression was examined in ESCC and corresponding adjacent normal tissues by immunohistochemistry and quantitative real-time PCR experiments. Elevated IL-33 levels were observed in ESCC tissues. Further in vitro experiments were undertaken to elucidate the effect of IL-33 on migration and invasion in KYSE-450 and Eca-109 esophageal cancer cells. Knockdown of IL-33 decreased the metastasis and invasion capacity in esophageal cancer cells, whereas IL-33 overexpression showed the opposite effect. We then screened CCL2 which is a downstream molecule of IL-33, and proved that IL-33 could promote tumor development and metastasis by recruiting regulatory T cells (Tregs) through CCL2, and IL-33 regulated the expression of CCL2 through transforming growth factor-β in Treg cells. Knockdown of IL-33 decreased the development of human ESCC xenografts in BALB/c nude mice. Collectively, we found that the IL-33/nuclear factor-κB/CCL2 pathway played an essential role in human ESCC progress. Hence, IL-33 should be considered as an effective therapy target for ESCC.

The Repertoire of Serous Ovarian Cancer Non-genetic Heterogeneity Revealed by Single-Cell Sequencing of Normal Fallopian Tube Epithelial Cells

The inter-differentiation between cell states promotes cancer cell survival under stress and fosters non-genetic heterogeneity (NGH). NGH is, therefore, a surrogate of tumor resilience but its quantification is confounded by genetic heterogeneity. Here we show that NGH in serous ovarian cancer (SOC) can be accurately measured when informed by the molecular signatures of the normal fallopian tube epithelium (FTE) cells, the cells of origin of SOC. Surveying the transcriptomes of ∼6,000 FTE cells, predominantly from non-ovarian cancer patients, identified 6 FTE subtypes. We used subtype signatures to deconvolute SOC expression data and found substantial intra-tumor NGH. Importantly, NGH-based stratification of ∼1,700 tumors robustly correlated with survival. Our findings lay the foundation for accurate prognostic and therapeutic stratification of SOC.

TYRO3 facilitates cell growth and metastasis via activation of the Wnt/β-catenin signaling pathway in human gastric cancer cells

It has become increasingly important to identify valuable therapeutic targets to improve the prognosis of cancer patients. Although emerging evidence has suggested TYRO3 as a potential therapeutic target in various types of cancers, less is known about its role in gastric cancer (GC) development. Herein, we investigated the functional and molecular mechanisms by which TYRO3 influenced GC. TYRO3 mRNA and protein were evaluated by quantitative real-time PCR (qRT-PCR), western blotting, and immunohistochemistry. Other methods including stable transfection of TYRO3 into GC cells, wound healing, Transwell assays, CCK-8 assays, colony formation assays, immunocytochemistry in vitro, and tumorigenesis in vivo were also conducted. Our results indicated that high levels of TYRO3 significantly correlated with clinical metastasis and poor prognoses in patients with GC. In addition, TYRO3 silencing distinctively suppressed GC cell growth, invasion, and metastasis both in vitro and in vivo. Conversely, TYRO3 overexpression led to the opposite effects. Mechanistic analyses revealed that the Wnt/β-catenin signaling pathway might be involved in TYRO3-facilitated GC cell behavior. Collectively, we demonstrated that elevated TYRO3 expression contributed to GC cell growth and metastasis via the Wnt/β-catenin pathway, suggesting a novel therapeutic target for GC.

Differential engagement of ORAI1 and TRPC1 in the induction of vimentin expression by different stimuli

The Ca²⁺ signal is essential in both hypoxia- and epidermal growth factor (EGF)-mediated epithelial to mesenchymal transition (EMT) in MDA-MB-468 breast cancer cells. This finding suggests that Ca²⁺-permeable ion channels participate in the induction of expression of some mesenchymal markers such as vimentin. However, the ion channels involved in vimentin expression induction have not been fully characterized. This work sought to define how differential modulation of the calcium signal effects the induction of vimentin and the Ca²⁺ influx pathways involved. We identified that the intracellular Ca²⁺ chelator EGTA-AM, cytochalasin D (a modulator of cytoskeletal dynamics and cell morphology), and the sarco/endoplasmic reticulum ATPase inhibitor thapsigargin are all inducers of vimentin in MDA-MB-468 breast cancer cells. EGTA-AM- and thapsigargin-mediated induction of vimentin expression in MDA-MB-468 cells involves store-operated Ca²⁺ entry, as evidenced by sensitivity to silencing of the molecular components of this pathway, STIM1 and ORAI1. In stark contrast, cytochalasin D-mediated vimentin induction was insensitive to silencing of ORAI1, despite sensitivity to silencing of its canonical activator the endoplasmic reticulum Ca²⁺ sensor STIM1. Cytochalasin D-mediated vimentin induction was, however, sensitive to silencing of another reported STIM1 target, TRPC1. Subsequent studies identified that EGTA-AM-induced vimentin expression also partially involved a TRPC1-dependent pathway. These studies define a complex interplay between vimentin expression in this model and the specific Ca²⁺-permeable ion channels involved. The complexity in the engagement of different Ca²⁺ influx pathways that regulate vimentin induction are opportunities but also potential challenges in targeting Ca²⁺ signaling to block EMT in cancer cells. Our findings further highlight the need to identify potential indispensable ion channels that can regulate induction of specific mesenchymal markers via different stimuli.

Small molecule inhibitors of epithelial-mesenchymal transition for the treatment of cancer and fibrosis

Tissue fibrosis and cancer both lead to high morbidity and mortality worldwide; thus, effective therapeutic strategies are urgently needed. Because drug resistance has been widely reported in fibrotic tissue and cancer, developing a strategy to discover novel targets for targeted drug intervention is necessary for the effective treatment of fibrosis and cancer. Although many factors lead to fibrosis and cancer, pathophysiological analysis has demonstrated that tissue fibrosis and cancer share a common process of epithelial-mesenchymal transition (EMT). EMT is associated with many mediators, including transcription factors (Snail, zinc-finger E-box-binding protein and signal transducer and activator of transcription 3), signaling pathways (transforming growth factor-β1, RAC-α serine/threonine-protein kinase, Wnt, nuclear factor-kappa B, peroxisome proliferator-activated receptor, Notch, and RAS), RNA-binding proteins (ESRP1 and ESRP2) and microRNAs. Therefore, drugs targeting EMT may be a promising therapy against both fibrosis and tumors. A large number of compounds that are synthesized or derived from natural products and their derivatives suppress the EMT by targeting these mediators in fibrosis and cancer. By targeting EMT, these compounds exhibited anticancer effects in multiple cancer types, and some of them also showed antifibrotic effects. Therefore, drugs targeting EMT not only have both antifibrotic and anticancer effects but also exert effective therapeutic effects on multiorgan fibrosis and cancer, which provides effective therapy against fibrosis and cancer. Taken together, the results highlighted in this review provide new concepts for discovering new antifibrotic and antitumor drugs.

Targeting Histone Methyltransferase DOT1L by a Novel Psammaplin A Analog Inhibits Growth and Metastasis of Triple-Negative Breast Cancer

Triple-negative breast cancer (TNBC) is the most intractable cancer in women with a high risk of metastasis. While hyper-methylation of histone H3 catalyzed by disruptor of telomeric silencing 1-like (DOT1L), a specific methyltransferase for histone H3 at lysine residue 79 (H3K79), is reported as a potential target for TNBCs, early developed nucleoside-type DOT1L inhibitors are not sufficient for effective inhibition of growth and metastasis of TNBC cells. We found that TNBC cells had a high expression level of DOT1L and a low expression level of E-cadherin compared to normal breast epithelial cells and non-TNBC cells. Here, a novel psammaplin A analog (PsA-3091) exhibited a potent inhibitory effect of DOT1L-mediated H3K79 methylation. Consistently, PsA-3091 also significantly inhibited the proliferation, migration, and invasion of TNBC cells along with the augmented expression of E-cadherin and the suppression of N-cadherin, ZEB1, and vimentin expression. In an orthotopic mouse model, PsA-3091 effectively inhibited lung metastasis and tumor growth by the regulation of DOT1L activity and EMT biomarkers. Together, we report here a new template of DOT1L inhibitor and suggest that targeting DOT1L-mediated H3K79 methylation by a novel PsA analog may be a promising strategy for the treatment of metastatic breast cancer patients.

Nanomaterials as Inhibitors of Epithelial Mesenchymal Transition in Cancer Treatment

Abstract: Epithelial-mesenchymal transition (EMT) has emerged as a key regulator of cell invasion and metastasis in cancers. Besides the acquisition of migratory/invasive abilities, the EMT process is tightly connected with the generation of cancer stem cells (CSCs), thus contributing to chemoresistance. However, although EMT represents a relevant therapeutic target for cancer treatment, its application in the clinic is still limited due to various reasons, including tumor-stage heterogeneity, molecular-cellular target specificity, and appropriate drug delivery. Concerning this last point, different nanomaterials may be used to counteract EMT induction, providing novel therapeutic tools against many different cancers. In this review, (1) we discuss the application of various nanomaterials for EMT-based therapies in cancer, (2) we summarize the therapeutic relevance of some of the proposed EMT targets, and (3) we review the potential benefits and weaknesses of each approach.

Controversies around epithelial-mesenchymal plasticity in cancer metastasis

Experimental evidence accumulated over decades has implicated epithelial-mesenchymal plasticity (EMP), which collectively encompasses epithelial-mesenchymal transition and the reverse process of mesenchymal-epithelial transition, in tumour metastasis, cancer stem cell generation and maintenance, and therapeutic resistance. However, the dynamic nature of EMP processes, the apparent need to reverse mesenchymal changes for the development of macrometastases and the likelihood that only minor cancer cell subpopulations exhibit EMP at any one time have made such evidence difficult to accrue in the clinical setting. In this Perspectives article, we outline the existing preclinical and clinical evidence for EMP and reflect on recent controversies, including the failure of initial lineage-tracing experiments to confirm a major role for EMP in dissemination, and discuss accumulating data suggesting that epithelial features and/or a hybrid epithelial-mesenchymal phenotype are important in metastasis. We also highlight strategies to address the complexities of therapeutically targeting the EMP process that give consideration to its spatially and temporally divergent roles in metastasis, with the view that this will yield a potent and broad class of therapeutic agents.

PKCα Modulates Epithelial-to-Mesenchymal Transition and Invasiveness of Breast Cancer Cells Through ZEB1

ZEB1 is a master regulator of the Epithelial-to-Mesenchymal Transition (EMT) program. While extensive evidence confirmed the importance of ZEB1 as an EMT transcription factor that promotes tumor invasiveness and metastasis, little is known about its regulation. In this work, we screened for potential regulatory links between ZEB1 and multiple cellular kinases. Exploratory in silico analysis aided by phospho-substrate antibodies and ZEB1 deletion mutants led us to identify several potential phospho-sites for the family of PKC kinases in the N-terminus of ZEB1. The analysis of breast cancer cell lines panels with different degrees of aggressiveness, together with the evaluation of a battery of kinase inhibitors, allowed us to expose a robust correlation between ZEB1 and PKCα both at mRNA and protein levels. Subsequent validation experiments using siRNAs against PKCα revealed that its knockdown leads to a concomitant decrease in ZEB1 levels, while ZEB1 knockdown had no impact on PKCα levels. Remarkably, PKCα-mediated downregulation of ZEB1 recapitulates the inhibition of mesenchymal phenotypes, including inhibition in cell migration and invasiveness. These findings were extended to an in vivo model, by demonstrating that the stable knockdown of PKCα using lentiviral shRNAs markedly impaired the metastatic potential of MDA-MB-231 breast cancer cells. Taken together, our findings unveil an unforeseen regulatory pathway comprising PKCα and ZEB1 that promotes the activation of the EMT in breast cancer cells.

Tumor Budding and Prognosis in Gastric Adenocarcinoma

Tumor budding has been associated with poor prognosis in several cancer types, but its significance in gastric cancer is unknown. The aim of this study was to assess the prognostic significance of tumor budding in gastric adenocarcinoma, and its main histologic types. Some 583 gastric adenocarcinoma patients who underwent surgery in Oulu University Hospital during the years 1983-2016 were included in this retrospective cohort study. Tumor budding was counted per 0.785 mm fields from the slides originally used for diagnostic purposes. Patients were divided into low-budding (<10 buds) and high-budding (≥10 buds) groups. Tumor budding was analyzed in relation to 5-year survival and overall survival. Cox regression was used to calculate hazard ratios (HR) with 95% confidence intervals (CI), adjusted for confounders. Determining tumor budding was difficult in diffuse-type cancer due to the uncohesive growth pattern of these tumors. Patients with high tumor budding had worse 5-year survival compared with patients with low tumor budding (adjusted HR, 1.55; 95% CI, 1.20-2.01). In intestinal-type adenocarcinomas, the high-budding group had significantly poorer 5-year survival compared with the low-budding group (adjusted HR, 1.57; 95% CI, 1.14-2.15). There were no differences in 5-year survival between the budding groups in the diffuse type adenocarcinoma. In conclusion, high tumor budding is an independent prognostic factor in gastric adenocarcinoma, but its value is limited to the intestinal type of gastric adenocarcinoma. In diffuse type gastric adenocarcinoma, the assessment of tumor budding is hardly feasible, and it does not have prognostic relevance.

Syndecan-2 in colorectal cancer plays oncogenic role via epithelial-mesenchymal transition and MAPK pathway

PURPOSE

In this study, we aimed to elucidate the biological roles of Syndecan-2 (SDC2) in colorectal cancer (CRC), thereby further understanding its clinical role.

METHODS

The expression of SDC2 was assessed by qRT-PCR and Western blot analysis. To understand the potential biological role of SDC2, we also explored the correlation between its expression level and clinicopathologic parameters. By using MTT, plate colony formation assay, Transwell invasion assays, and flow cytometry in vitro, the biological impact of SDC2 on CRC cell proliferation, migration, invasion, and apoptosis. In addition, the related signaling pathways were investigated.

RESULTS

SDC2 expression was significantly upregulated in CRC tissues. The expression of SDC2 was highly associated with four parameters, i.e., stage (P < 0.01), vascular invasion (P = 0.0045), lymph node metastasis (P=0.0018), and distant metastasis (P = 0.0019). Knockdown of SDC2 significantly reduced proliferation, migration, and invasion of HCT116 and SW480 cells, and induced cell apoptosis. Moreover, SDC2 promoted epithelial-mesenchymal transition (EMT) in CRC cells, whereas the ratio of p-MEK/MEK and p-ERK/ERK markedly reduced after depleting SDC2.

CONCLUSION

During CRC development, overexpression of SDC2 plays a carcinogenic role in CRC. Therapeutic solutions targeting SDC2 may provide potential insights into CRC prevention and treatment.

HGF/MET Regulated Epithelial-Mesenchymal Transitions And Metastasis By FOSL2 In Non-Small Cell Lung Cancer

Background

HGF/MET has been found to be associated with non-small cell lung cancer (NSCLC). However, the underlying molecular mechanisms of HGF/MET involved in regulating the metastasis of NSCLC remain unclear.

Methods

The effect of HGF/MET and FOSL2 on cell migration and invasion were assessed by transwell and scratch assays. HGF/MET-induced phosphorylation and upregulation of FOSL2 was analyzed by RT-PCR and Western blotting. Regulatory effects of FOSL2 on SNAI2 transcription were detected by chromatin immunoprecipitation (ChIP) and dual-Luciferase reporter assays. The correlations of FOSL2 expression with clinical outcomes were assessed in 56 NSCLC patients.

Results

HGF/MET induced the phosphorylation and upregulation of FOSL2 by ERK1/2 kinase, FOSL2 promoted the transcription of SNAI2 by binding with the SNAI2 promoter, and SNAI2 subsequently promoted the epithelial-mesenchymal transition (EMT), invasion, and migration of NSCLC cells. According to the clinical correlation analysis in NSCLC, high expression of FOSL2 correlated with advanced tumor stage and metastasis.

Conclusion

Our studies propose that the regulatory mechanisms of the HGF/MET-induced cascade pathway is mediated by FOSL2 in NSCLC metastasis and suggested that FOSL2 could potentially be employed as a prognostic biomarker and potential therapeutic target of NSCLC metastasis.

Gene signatures of tumor inflammation and epithelial-to-mesenchymal transition (EMT) predict responses to immune checkpoint blockade in lung cancer with high accuracy

OBJECTIVES

Treatment of non-small cell lung cancer (NSCLC) with immune checkpoint blockade (ICB) has resulted in striking clinical responses, but only in a subset of patients. The goal of this study was to evaluate transcriptional signatures previously reported in the literature in an independent cohort of NSCLC patients receiving ICB.

MATERIALS AND METHODS

This retrospective study analyzed transcriptional profiles from pre-treatment tumor samples of 52 chemotherapy-refractory advanced NSCLC patients treated with anti-PD1/PD-L1 therapy. Gene signatures based on published reports were created and examined for their association with response to therapy and progression-free and overall survival (PFS, OS).

RESULTS

Two signatures predicting response and outcomes were identified. One reflected the degree of immune infiltration and upregulation of interferon-gamma-induced genes. A second reflected the EMT status. Compared to those not responding to therapy, patients whose tumors responded to ICB had higher scores in an inflammatory gene signature (6.0 ± 2.9 vs -5.5 ± 3.4, p = 0.014) or a more epithelial phenotype (-1.7 ± 1.0 vs 2.1 ± 1.2, p = 0.016). Both signatures demonstrated a satisfactory predictive accuracy for response: AUC of 0.69 (95% CI: 0.54, 0.84) for the inflammatory and 0.70 (95% CI: 0.55, 0.85) for EMT signatures, respectively. A weighted score combining EMT and inflammatory signatures showed increased predictive value with AUC of 0.92 (95% CI: 0.85, 0.99). Kaplan-Meier curves for patients above and below the median combined score showed a significant separation for PFS and OS (all p < 0.01, log rank test).

CONCLUSIONS

The EMT/Inflammation signature score may be useful in directing checkpoint inhibitor therapy in lung cancer and suggests that reversal of EMT might augment efficacy of ICB.

Sarcomatoid carcinoma presenting as cancers of unknown primary: a clinicopathological portrait

Background

Sarcomatoid carcinoma of unknown primary (SCUP) is a rare entity of either poorly differentiated carcinoma with sarcoma-like differentiation or a true mixed lineage neoplasm. Limited data regarding clinicopathological profile and management exists.

Methods

We retrospectively reviewed the MD Anderson Cancer of Unknown Primary database and tumor registry to identify 48 SCUP patients between 2001 and 2017. Patient characteristics, pathology, molecular diagnostics, treatments, and outcomes were obtained. Kaplan-Meier method was used to estimate overall survival (OS) and compared using log rank test.

Results

Median age at diagnosis was 59 years (range 27–86). Majority of patients were female (58%) and presented with ≥3 metastatic sites (52%), commonly lymph node (50%), bone (42%), lung (27%), and liver (21%). First line treatment included chemotherapy (35%), surgery (27%), and radiation (24%). Gemcitabine and docetaxel (18%) was the most common chemotherapy regimen. Median OS for entire cohort was 11 months (95% CI: 5.6 to 16.4). Poor performance status (PS), > 1 metastatic site, elevated lactate dehydrogenase (LDH), and high neutrophil-to-lymphocyte ratio (NLR) were significantly associated with worse OS on univariate analyses. On multivariate analyses, poor PS (HR 8.7; 95%CI: 3.0–25.0; p <  0.001) and high NLR (HR 3.4; 95%CI: 1.3–8.8; p = 0.011) emerged as independent prognostic factors for OS.

Conclusions

SCUP is a rare presentation with an aggressive clinical course and limited survival. Diagnosis is difficult to make and requires careful review and synthesis of histology, immunohistochemistry, and molecular diagnostics. Chemotherapy resistance remains a challenge. Early mutational profiling is warranted, and clinical trial participation should be encouraged for this subset.

Downregulation of nicotinamide N-methyltransferase inhibits migration and epithelial-mesenchymal transition of esophageal squamous cell carcinoma via Wnt/β-catenin pathway

Nicotinamide N-methyltransferase (NNMT) is an important methyltransferase involved in the biotransformation of many drugs and exogenous compounds. Abnormal expression of NNMT protein is closely associated with the onset and progression of many malignancies, but little is known about its role in esophageal squamous cell carcinoma (ESCC). Therefore, we aimed to explore whether NNMT plays any roles in carcinogenesis and metastasis in ESCC. NNMT expression was determined by immunohistochemistry in ESCC and corresponding adjacent normal tissues. Functional experiments were performed to elucidate the effects of NNMT knockdown on the proliferation, apoptosis, cell cycle, migration, and epithelial-mesenchymal transition (EMT) in EC9706 and TE1 cells. NNMT expression was significantly elevated in ESCC tissues compared with corresponding adjacent normal tissues. Moreover, a significant association emerged between NNMT expression and lymph node metastasis. SiRNA-mediated knockdown of NNMT in ESCC cells can significantly suppress cell viability and migration, induce cell cycle arrest, and promote cell apoptosis. In addition, NNMT downregulation led to the reversal of EMT, as reflected by upregulation of the intercellular adhesion molecule E-cadherin and downregulation of the mesenchymal markers N-cadherin and Vimentin. Further study found that NNMT knockdown suppressed the Wnt/β-catenin signaling pathway. Taken together, these findings indicate that NNMT is a critical regulator of EMT in ESCC and may be a potential therapeutic target for ESCC metastasis.

Upregulation of SCNN1A Promotes Cell Proliferation, Migration, and Predicts Poor Prognosis in Ovarian Cancer Through Regulating Epithelial-Mesenchymal Transformation

Background: There is little knowledge about the biological roles and clinical significance of SCNN1A in ovarian cancer. Thus, the objective of this study was to investigate the biological functions and prognosis value of SCNN1A in ovarian cancer to further seek a potential therapeutic target for patients with ovarian cancer. Materials and Methods: First, the expression level of SCNN1A in ovarian cancer samples obtained from ONCOMINE database was determined, and its expression in cell lines was also investigated. Moreover, correlation analysis was performed to determine the relationship between SCNN1A expression and prognosis in ovarian cancer patients according to the data obtained from GEPIA database and Kaplan-Meier plotter website. The biological roles of SCNN1A on cell growth, migration, and invasion were then examined by knockdown of SCNN1A in ovarian cancer cell line SK-OV-3. Ultimately, Western blotting analysis was carried out to investigate the expression of epithelial-mesenchymal transformation markers (including E-cadherin, N-cadherin, Vimentin, and Snail) after silencing SCNN1A. Results: Based on the ONCOMINE-related data and cell lines, SCNN1A was observed to be overexpressed in ovarian cancer samples and cell lines. Survival analysis showed that high expression of SCNN1A was associated with poor overall survival and progression-free survival in ovarian cancer patients. In addition, SCNN1A silence remarkably blocked SK-OV-3 cell growth ability, migration, and invasion potential. Western blotting results showed that SCNN1A silence led to an increase in E-cadherin, whereas a decrease in N-cadherin, Vimentin, and Snail in SK-OV-3 cells. Increased E-cadherin and decreased N-cadherin, Vimentin, as well as Snail inhibited cell invasion of ovarian cancer. Conclusions: SCNN1A might exert crucial roles in cell growth and invasion and migration in ovarian cancer, and might be a potential indicator for prognosis and a therapeutic target for ovarian cancer patients.

Ovarian Primary and Metastatic Tumors Suppressed by Survivin Knockout or a Novel Survivin Inhibitor

Survivin, a member of the inhibitor of apoptosis family, is upregulated in multiple cancers including ovarian cancer, but is rarely detectable in normal tissues. We previously reported that survivin promoted epithelial-to-mesenchymal transition (EMT) in ovarian cancer cells, suggesting that survivin may contribute to ovarian tumor metastasis and chemoresistance. In this study, we tested whether knockout or pharmacologic inhibition of survivin overcomes chemoresistance and suppresses tumor metastasis. The genetic loss of survivin suppressed tumor metastasis in an orthotopic ovarian cancer mouse model. To pharmacologically test the role of survivin on ovarian tumor metastasis, we treated chemo-resistant ovarian cancer cells with a selective survivin inhibitor, MX106, and found that MX106 effectively overcame chemoresistance in vitro MX106 inhibited cell migration and invasion by attenuating the TGFβ pathway and inhibiting EMT in ovarian cancer cells. To evaluate the efficacy of MX106 in inhibiting ovarian tumor metastasis, we treated an orthotopic ovarian cancer mouse model with MX106, and found that MX106 efficiently inhibited primary tumor growth in ovaries and metastasis in multiple peritoneal organs as compared with vehicle-treated control mice. Our data demonstrate that inhibition of survivin using either genetic knockout or a novel inhibitor MX106 suppresses primary ovarian tumor growth and metastasis, supporting that targeting survivin could be an effective therapeutic approach in ovarian cancer.

The Molecular Mechanism of Epithelial-Mesenchymal Transition for Breast Carcinogenesis

The transforming growth factor-β (TGF-β) signaling pathway plays multiple regulatory roles in the tumorigenesis and development of cancer. TGF-β can inhibit the growth and proliferation of epithelial cells and induce apoptosis, thereby playing a role in inhibiting breast cancer. Therefore, the loss of response in epithelial cells that leads to the inhibition of cell proliferation due to TGF-β is a landmark event in tumorigenesis. As tumors progress, TGF-β can promote tumor cell invasion, metastasis, and drug resistance. At present, the above-mentioned role of TGF-β is related to the interaction of multiple signaling pathways in the cell, which can attenuate or abolish the inhibition of proliferation and apoptosis-promoting effects of TGF-β and enhance its promotion of tumor progression. This article focuses on the molecular mechanisms through which TGF-β interacts with multiple intracellular signaling pathways in tumor progression and the effects of these interactions on tumorigenesis.

Honokiol inhibits breast cancer cell metastasis by blocking EMT through modulation of Snail/Slug protein translation

Honokiol (HNK), an active compound isolated from traditional Chinese medicine Magnolia officinalis, has shown potent anticancer activities. In the present study, we investigated the effects of HNK on breast cancer metastasis in vitro and in vivo, as well as the underlying molecular mechanisms. We showed that HNK (10-70 μmol/L) dose-dependently inhibited the viability of human mammary epithelial tumor cell lines MCF7, MDA-MB-231, and mouse mammary tumor cell line 4T1. In the transwell and scratch migration assays, HNK (10, 20, 30 μmol/L) dose-dependently suppressed the invasion and migration of the breast cancer cells. We demonstrated that HNK (10-50 μmol/L) dose-dependently upregulated the epithelial marker E-cadherin and downregulated the mesenchymal markers such as Snail, Slug, and vimentin at the protein level in breast cancer cells. Using a puromycin incorporation assay, we showed that HNK decreased the Snail translation efficiency in the breast cancer cells. In a mouse model of tumor metastasis, administration of HNK (50 mg/kg every day, intraperitoneal (i.p.), 6 times per week for 30 days) significantly decreased the number of metastatic 4T1 cell-derived nodules and ameliorated the histological alterations in the lungs. In addition, HNK-treated mice showed decreased Snail expression and increased E-cadherin expression in metastatic nodules. In conclusion, HNK inhibits EMT in the breast cancer cells by downregulating Snail and Slug protein expression at the mRNA translation level. HNK has potential as an integrative medicine for combating breast cancer by targeting EMT.

Long non-coding RNA LINC01225 promotes proliferation, invasion and migration of gastric cancer via Wnt/β-catenin signalling pathway

Emerging evidence has classified the aberrant expression of long non-coding RNAs (lncRNAs) as a basic signature of various malignancies including gastric cancer (GC). LINC01225 has been shown to act as a hepatocellular carcinoma-related gene, with its expression pattern and biological function not clarified in GC. Here, we verified that LINC01225 was up-regulated in tumour tissues and plasma of GC. Analysis with clinicopathological information suggested that up-regulation of LINC01225 was associated with advanced disease and poorer overall survival. Receiver operating characteristic (ROC) analysis showed that plasma LINC01225 had a moderate accuracy for diagnosis of GC. In addition, knockdown of LINC01225 led to retardation of cell proliferation, invasion and migration, and overexpression of LINC01225 showed the opposite effects. Mechanistic investigations showed that LINC01225 silencing inhibited epithelial-mesenchymal transition (EMT) process and attenuated Wnt/β-catenin signalling of GC. Furthermore, ectopic expression of Wnt1 or suppression of GSK-3β abolished the si-LINC01225-mediated suppression against EMT, thereby promoting cell proliferation, invasion and migration of GC. In conclusion, LINC01225 promotes the progression of GC through Wnt/β-catenin signalling pathway, and it may serve as a potential target or strategy for diagnosis or treatment of GC.

Gemcitabine-induced epithelial-mesenchymal transition-like changes sustain chemoresistance of pancreatic cancer cells of mesenchymal-like phenotype

Growing body of evidence suggests that epithelial-mesenchymal transition (EMT) is a critical process in tumor progression and chemoresistance in pancreatic cancer (PC). The aim of this study was to analyze the role of EMT-like changes in acquisition of resistance to gemcitabine in pancreatic cells of the mesenchymal or epithelial phenotype. Therefore, chemoresistant BxPC-3, Capan-2, Panc-1, and MiaPaca-2 cells were selected by chronic exposure to increasing concentrations of gemcitabine. We show that gemcitabine-resistant Panc-1 and MiaPaca-2 cells of mesenchymal-like phenotype undergo further EMT-like molecular changes mediated by ERK-ZEB-1 pathway, and that inhibition of ERK1/2 phosphorylation or ZEB-1 expression resulted in a decrease in chemoresistance. Conversely, gemcitabine-resistant BxPC-3 and Capan-2 cells of epithelial-like phenotype did not show such typical EMT-like molecular changes although the expression of the tight junction marker occludin could be found decreased. In pancreatic cancer patients, high ZEB-1 expression was associated with tumor invasion and tumor budding. In addition, tumor budding was essentially observed in patients treated with neoadjuvant chemotherapy. These findings support the notion that gemcitabine treatment induces EMT-like changes that sustain invasion and chemoresistance in PC cells.

The Calcium-Signaling Toolkit in Cancer: Remodeling and Targeting

Processes that are important in cancer progression, such as sustained cell growth, invasion to other organs, and resistance to cell death inducers, have a clear overlap with pathways regulated by Ca²⁺ signaling. It is therefore not surprising that proteins important in Ca²⁺ signaling, sometimes referred to as the "Ca²⁺ signaling toolkit," can contribute to cancer cell proliferation and invasiveness, and the ability of agents to induce cancer cell death. Ca²⁺ signaling is also critical in other aspects of cancer progression, including events in the tumor microenvironment and processes involved in the acquisition of resistance to anticancer therapies. This review will consider the role of Ca²⁺ signaling in tumor progression and highlight areas in which a better understanding of the interplay between the Ca²⁺-signaling toolkit and tumorigenesis is still required.

Novel Diphenylamine Analogs Induce Mesenchymal to Epithelial Transition in Triple Negative Breast Cancer

Epithelial to mesenchymal transition (EMT) is a cellular program that converts non-motile epithelial cells into invasive mesenchymal cells. EMT is implicated in cancer metastasis, chemo-resistance, cancer progression, and generation of cancer stem cells (CSCs). Inducing mesenchymal to epithelial transition (MET), the reverse phenomenon of EMT, is proposed as a novel strategy to target triple negative and tamoxifen-resistant breast cancer. Triple negative breast cancer (TNBC) is characterized by the loss of hormone receptors, a highly invasive mesenchymal phenotype, and a lack of targeted therapy. Estrogen receptor-positive breast cancer can be targeted by tamoxifen, an ER antagonist. However, these cells undergo EMT over the course of treatment and develop resistance. Thus, there is an urgent need to develop therapeutic interventions to target these aggressive cancers. In this study, we examined the role of novel diphenylamine analogs in converting the mesenchymal phenotype of MDA-MB-231 TNBC cells to a lesser aggressive epithelial phenotype. Using analog-based drug design, a series of diphenylamine analogs were synthesized and initially evaluated for their effect on E-cadherin protein expression and changes incell morphology, which was quantified by measuring the spindle index (SI) value. Selected compound 1 from this series increases the expression of E-cadherin, a primary marker for epithelial cells, and decreases the mesenchymal markers SOX2, ZEB1, Snail, and vimentin. The increase in epithelial markers and the decrease in mesenchymal markers are consistent with a phenotypic switch from spindle-like morphology to cobblestone-like morphology. Furthermore, Compound 1 decreases spheroid viability, cell migration, and cell proliferation in triple negative BT-549 and tamoxifen-resistant MCF-7 breast cancer cells.

The Matrix Metalloproteinase-13 Inhibitor Poricoic Acid ZI Ameliorates Renal Fibrosis by Mitigating Epithelial-Mesenchymal Transition

SCOPE

Fibrosis plays a key role in the progression of various diseases. Matrix metalloproteinases (MMPs) are important for epithelial-mesenchymal transition (EMT), which contributes to organ fibrosis. Four new poricoic acids are identified, poricoic acid ZI, ZJ, ZK, and ZL, as novel MMP inhibitors from edible mushroom Poria cocos.

METHODS

Molecular docking, siRNA techniques, TGF-β1-treated renal cells, and unilateral ureteral obstructed (UUO) mice are used to explore the potential efficacy of the novel MMP inhibitors in mitigating the fibrotic process.

RESULTS

Treatment with four poricoic acids downregulates profibrotic protein expression in TGF-β1-induced HK-2 cells. Similar results are observed in NRK-52E and NRK-49F cells, indicating that poricoic acids can suppress EMT. Furthermore, both in vitro and in vivo experiments demonstrate that poricoic acid ZI (PZI) exerts a stronger inhibitory effect on protein expression and enzymatic activity of MMP-13 than the other three compounds, which is consistent with the docking results. The inhibitory effect of PZI on MMP-13 is partially attenuated by MMP-13 RNAi in HK-2 cells and UUO mice.

CONCLUSIONS

The findings indicate that as a specific MMP-13 inhibitor, PZI attenuates EMT and renal fibrosis. Therefore, the MMP-13 inhibitor PZI can be a novel therapeutic candidate for limiting EMT and renal fibrosis.

A peptide-modified solid lipid nanoparticle formulation of paclitaxel modulates immunity and outperforms dacarbazine in a murine melanoma model

Melanoma is a highly aggressive skin cancer. A paclitaxel formulation of solid lipid nanoparticles modified with Tyr-3-octreotide (PSM) is employed to treat melanoma that highly expresses somatostatin receptors (SSTRs). PSM exerts more apoptotic and anti-invasive effects in B16F10 mice melanoma cells as compared to dacarbazine (DTIC), an approved chemotherapeutic drug for treating aggressive melanoma. Besides, PSM induces one of the biomarkers of immunogenic cell death in vitro and in vivo as confirmed by calreticulin exposure on the B16F10 cell surface. We observed a significant number of CD8 positive T cells in the tumor bed of the PSM treated group. As a result, PSM effectively reduces tumor volume in vivo as compared to DTIC. PSM also induces a favorable systemic immune response as determined in the spleen and sera of the treated animals. Importantly, PSM can reduce the number of nodule formations in the experimental lung metastasis model. Our experimentations indicate that the metronomic PSM exhibits remarkable anti-melanoma activities without any observable toxicity. This immune modulation behavior of PSM can be exploited for the therapy of melanoma and probably for other malignancies.

Inhibition of BRD4 suppresses the malignancy of breast cancer cells via regulation of Snail

The mechanistic action of bromodomain-containing protein 4 (BRD4) in cancer motility, including epithelial-mesenchymal transition (EMT), remains largely undefined. We found that targeted inhibition of BRD4 reduces migration, invasion, in vivo growth of patient-derived xenograft (PDX), and lung colonization of breast cancer (BC) cells. Inhibition of BRD4 rapidly decreases the expression of Snail, a powerful EMT transcription factor (EMT-TF), via diminishing its protein stability and transcription. Protein kinase D1 (PRKD1) is responsible for BRD4-regulated Snail protein stability by triggering phosphorylation at Ser11 of Snail and then inducing proteasome-mediated degradation. BRD4 inhibition also suppresses the expression of Gli1, a key transductor of Hedgehog (Hh) required to activate the transcription of SNAI1, in BC cells. The GACCACC sequence (-341 to -333) in the SNAI1 promoter is responsible for Gli1-induced transcription of SNAI1. Clinically, BRD4 and Snail levels are increased in lung-metastasized, estrogen receptor-negative (ER-), and progesterone receptor-negative (PR-) breast cancers and correlate with the expression of mesenchymal markers. Collectively, BRD4 can regulate malignancy of breast cancer cells via both transcriptional and post-translational regulation of Snail.

p53-Mediated PI3K/AKT/mTOR Pathway Played a Role in PtoxDpt-Induced EMT Inhibition in Liver Cancer Cell Lines

Epithelial-mesenchymal transition (EMT) involves metastasis and drug resistance; thus, a new EMT reversing agent is required. It has shown that wild-type p53 can reverse EMT back to epithelial characteristics, and iron chelator acting as a p53 inducer has been demonstrated. Moreover, recent study revealed that etoposide could also inhibit EMT. Therefore, combination of etoposide with iron chelator might achieve better inhibition of EMT. To this end, we prepared di-2-pyridineketone hydrazone dithiocarbamate S-propionate podophyllotoxin ester (Ptox^Dpt) that combined the podophyllotoxin (Ptox) structural unit (etoposide) with the dithiocarbamate unit (iron chelator) through the hybridization strategy. The resulting Ptox^Dpt inherited characteristics from parent structural units, acting as both the p53 inducer and topoisomerase II inhibitor. In addition, the Ptox^Dpt exhibited significant inhibition in migration and invasion, which correlated with downregulation of matrix metalloproteinase (MMP). More importantly, Ptox^Dpt could inhibit EMT in the absence or presence of TGF-β1, concomitant to the ROS production, and the additional evidence revealed that Ptox^Dpt downregulated AKT/mTOR through upregulation of p53, indicating that Ptox^Dpt induced EMT inhibition through the p53/PI3K/AKT/mTOR pathway.

Embryonic Chicken (Gallus gallus domesticus) as a Model of Cardiac Biology and Development

Cardiovascular disease remains one of the top contributors to morbidity and mortality in the United States. Increasing evidence suggests that many processes, pathways, and programs observed during development and organogenesis are recapitulated in adults in the face of disease. Therefore, a heightened understanding of cardiac development and organogenesis will help increase our understanding of developmental defects and cardiovascular diseases in adults. Chicks have long served as a model system in which to study developmental problems. Detailed descriptions of morphogenesis, low cost, accessibility, ease of manipulation, and the optimization of genetic engineering techniques have made chicks a robust model for studying development and make it a powerful platform for cardiovascular research. This review summarizes the cardiac developmental milestones of embryonic chickens, practical considerations when working with chicken embryos, and techniques available for use in chicks (including tissue chimeras, genetic manipulations, and live imaging). In addition, this article highlights examples that accentuate the utility of the embryonic chicken as model system in which to study cardiac development, particularly epicardial development, and that underscore the importance of how studying development informs our understanding of disease.

Reduced USP33 expression in gastric cancer decreases inhibitory effects of Slit2-Robo1 signalling on cell migration and EMT

OBJECTIVES

Gastric cancer (GC) is one of the most common cancers in the world, causing a large number of deaths every year. The Slit-Robo signalling pathway, initially discovered for its critical role in neuronal guidance, has recently been shown to modulate tumour invasion and metastasis in several human cancers. However, the role of Slit-Robo signalling and the molecular mechanisms underlying its role in the pathogenesis of gastric cancer remains to be elucidated.

MATERIALS AND METHODS

Slit2, Robo1 and USP33 expressions were analysed in datasets obtained from the Oncomine database and measured in human gastric cancer specimens. The function of Slit2-Robo1-USP33 signalling on gastric cancer cells migration and epithelial-mesenchymal transition (EMT) was studied both in vitro and in vivo. The mechanism of the interaction between Robo1 and USP33 was explored by co-IP and ubiquitination protein analysis.

RESULTS

The mRNA and protein levels of Slit2 and Robo1 are lower in GC tissues relative to those in adjacent healthy tissues. Importantly, Slit2 inhibits GC cell migration and suppresses EMT process in a Robo-dependent manner. The inhibitory function of Slit2-Robo1 is mediated by ubiquitin-specific protease 33 (USP33) via deubiquitinating and stabilizing Robo1. USP33 expression is decreased in GC tissues, and reduced USP33 level is correlated with poor patient survival.

CONCLUSIONS

Our study reveals the inhibitory function of Slit-Robo signalling in GC and uncovers a role of USP33 in suppressing cancer cell migration and EMT by enhancing Slit2-Robo1 signalling. USP33 represents a feasible choice as a prognostic biomarker for GC.

A-kinase-interacting protein 1 facilitates growth and metastasis of gastric cancer cells via Slug-induced epithelial-mesenchymal transition

A‐kinase‐interacting protein 1 (AKIP1) has previously been reported to act as a potential oncogenic protein in various cancers. The clinical significance and biological role of AKIP1 in gastric cancer (GC) is, however, still elusive. Herein, this study aimed to investigate the functional and molecular mechanism by which AKIP1 influences GC. AKIP1 mRNA and protein expressions in GC tissues were examined by quantitative real‐time PCR (qRT‐PCR), Western blot and immunohistochemistry. Other methods including stably transfected against AKIP1 into gastric cancer cells, wound healing, transwell assays, CCK‐8, colony formation, qRT‐PCR and Western blot in vitro and tumorigenesis in vivo were also performed. The up‐regulated expression of AKIP1 in GC specimens significantly correlated with clinical metastasis and poor prognosis in patients with GC. AKIP1 knockdown markedly suppressed GC cells proliferation, invasion and metastasis both in vitro and in vivo. In contrast, AKIP1 overexpression resulted in the opposite effects. Moreover, mechanistic analyses indicated that Slug‐induced epithelial‐mesenchymal transition (EMT) might be responsible for AKIP1‐influenced GC cells behaviour. Our findings demonstrated that high AKIP1 expression significantly correlated with clinical metastasis and unfavourable prognosis in patients with GC. Additionally, AKIP1 promoted GC cells proliferation, migration and invasion by activating Slug‐induced EMT.

Preparation and Evaluation of Liposomes Co-Loaded with Doxorubicin, Phospholipase D Inhibitor 5-Fluoro-2-Indolyl Deschlorohalopemide (FIPI) and D-Alpha Tocopheryl Acid Succinate (α-TOS) for Anti-Metastasis

Tumor metastasis has become a key obstacle to cancer treatment, which causes high mortality. Nowadays, it involves multiple complex pathways, and conventional treatments are not effective due to fewer targets. The aims of the present study were to construct a novel liposome delivery system co-loading a specific PLD inhibitor 5-fluoro-2-indolyldes-chlorohalopemide (FIPI) in combination with antitumor drug doxorubicin (DOX) and functional excipient D-alpha tocopheryl acid succinate (α-TOS) for anti-metastasis. In this study, the liposomes containing three components (DFT-Lip) with different physicochemical properties were successfully prepared by film dispersion method combined with pH-gradient method. Physicochemical parameters such as particles size, potential, encapsulation efficiency, stability, and release profiles were investigated. In vitro and in vivo anti-metastasis effectiveness against highly metastatic breast cancer MDA-MB-231 cell line was evaluated. The liposomes showed uniform particle size (approximately 119 nm), high drug encapsulation efficiency (> 90%), slow release characteristics and stability. In vitro anti-tumor cell metastasis study demonstrated DFT-Lip could greatly inhibit motility, migration and invasion of MDA-MB-231 cells compared to other liposomes, predicting a synergistic anti-tumor metastasis effect between FIPI with α-TOS in liposomes. In vivo anti-metastasis study showed that DFT-Lip prevented the initiation and the progression of metastasis of high metastatic breast cancer. These results suggested that the liposomes containing DOX, FIPI, and α-TOS might be a promising strategy for metastatic tumor therapy in clinics.

m6A-induced lncRNA RP11 triggers the dissemination of colorectal cancer cells via upregulation of Zeb1

Background

Long noncoding RNAs (lncRNAs) have emerged as critical players in cancer progression, but their functions in colorectal cancer (CRC) metastasis have not been systematically clarified.

Methods

lncRNA expression profiles in matched normal and CRC tissue were checked using microarray analysis. The biological roles of a novel lncRNA, namely RP11-138 J23.1 (RP11), in development of CRC were checked both in vitro and in vivo. Its association with clinical progression of CRC was further analyzed.

Results

RP11 was highly expressed in CRC tissues, and its expression increased with CRC stage in patients. RP11 positively regulated the migration, invasion and epithelial mesenchymal transition (EMT) of CRC cells in vitro and enhanced liver metastasis in vivo. Post-translational upregulation of Zeb1, an EMT-related transcription factor, was essential for RP11-induced cell dissemination. Mechanistically, the RP11/hnRNPA2B1/mRNA complex accelerated the mRNA degradation of two E3 ligases, Siah1 and Fbxo45, and subsequently prevented the proteasomal degradation of Zeb1. m⁶A methylation was involved in the upregulation of RP11 by increasing its nuclear accumulation. Clinical analysis showed that m⁶A can regulate the expression of RP11, further, RP11 regulated Siah1-Fbxo45/Zeb1 was involved in the development of CRC.

Conclusions

m⁶A-induced lncRNA RP11 can trigger the dissemination of CRC cells via post-translational upregulation of Zeb1. Considering the high and specific levels of RP11 in CRC tissues, our present study paves the way for further investigations of RP11 as a predictive biomarker or therapeutic target for CRC.

Electronic supplementary material

The online version of this article (10.1186/s12943-019-1014-2) contains supplementary material, which is available to authorized users.

Epithelial Mesenchymal Transition in Tumor Metastasis

Metastasis is the major cause of cancer-related deaths; therefore, the prevention and treatment of metastasis are fundamental to improving clinical outcomes. Epithelial mesenchymal transition (EMT), an evolutionarily conserved developmental program, has been implicated in carcinogenesis and confers metastatic properties upon cancer cells by enhancing mobility, invasion, and resistance to apoptotic stimuli. Furthermore, EMT-derived tumor cells acquire stem cell properties and exhibit marked therapeutic resistance. Given these attributes, the complex biological process of EMT has been heralded as a key hallmark of carcinogenesis, and targeting EMT pathways constitutes an attractive strategy for cancer treatment. However, demonstrating the necessity of EMT for metastasis in vivo has been technically challenging, and recent efforts to demonstrate a functional contribution of EMT to metastasis have yielded unexpected results. Therefore, determining the functional role of EMT in metastasis remains an area of active investigation. Studies using improved lineage tracing systems, dynamic in vivo imaging, and clinically relevant in vivo models have the potential to uncover the direct link between EMT and metastasis. This review focuses primarily on recent advances in and emerging concepts of the biology of EMT in metastasis in vivo and discusses future directions in the context of novel diagnostic and therapeutic opportunities.

SOX5 promotes cell invasion and metastasis via activation of Twist-mediated epithelial-mesenchymal transition in gastric cancer

Background

Sex-determining region Y-box protein 5 (SOX5) has been demonstrated to be implicated in oncogenic function in various types of cancers. However, the role of SOX5 in gastric cancer (GC) remains poorly elucidated. Herein, we investigated the role and the underlying mechanism of SOX5 in GC progression.

Methods

SOX5 mRNA and protein expression were detected by quantitative real-time PCR (qRT-PCR), Western blot and immunohistochemistry in human GC specimens, and their clinical significance was evaluated. The effects of SOX5 knockdown or overexpression on GC cell behavior were determined by proliferation, wound-healing and transwell assays in vitro, and metastasis assays in vivo; and epithelial-mesenchymal transition (EMT)-related markers were detected by qRT-PCR, Western blot and immunofluorescence staining.

Results

The up-regulated expression of SOX5 in GC specimens was significantly correlated with clinical metastasis and poor prognosis for patients with GC. Besides, SOX5 promoted GC cell migration and invasion in vitro, as well as GC cell metastasis in vivo. Mechanically, Twist-mediated EMT was likely involved in SOX5-facilitated GC cell behavior.

Conclusion

SOX5 has an important function in GC progression. In addition, SOX5 promotes GC cell invasion and metastasis via activation of Twist-mediated EMT, thus providing a potential therapeutic target for GC metastasis.

[Research progress of exosomes in epithelial-mesenchymal transition]

Exosome, a membranous vesicle with biological activity, not only transmits active substances between cells but also transfers information between cells to participate in cell communication. Epithelial-mesenchymal transition (EMT) is a process by which epithelial cells acquire migratory and invasive properties to become mesenchymal stem cells. EMT is essential for the development of a spectrum of diseases. Studies have shown that exosomes have dual effects on EMT to, on the one hand, promote EMT and tumor cell invasion and metastasis and accelerate angiogenesis and tumor growth; on the other hand, exosomes can suppress tumor cell invasion, inhibit fibrosis of the heart, liver and kidney, and improve myocardial infarction by inhibiting EMT. Exosomes modulate EMT-related signaling pathways by carrying EMT-related proteins or miRNA to exert their bi-directional regulatory effects.

Prevention of epithelial to mesenchymal transition in colorectal carcinoma by regulation of the E-cadherin-β-catenin-vinculin axis

Epithelial to mesenchymal transition (EMT) is compulsory for metastatic dissemination and is stimulated by TGF-β. Although targeting EMT has significant therapeutic potential, very few pharmacological agents have been shown to exert anti-metastatic effects. BI-69A11, a competitive Akt inhibitor, displays anti-tumor activity toward melanoma and colon carcinoma. This study provides molecular and biochemical insights into the effects of BI-69A11 on EMT in colon carcinoma cells in vitro and in vivo. BI-69A11 inhibited metastasis-associated cellular migration, invasion and adhesion by inhibiting the Akt-β-catenin pathway. The underlying mechanism of BI-69A11-mediated inhibition of EMT included suppression of nuclear transport of β-catenin and diminished phosphorylation of β-catenin, which was accompanied by enhanced E-cadherin-β-catenin complex formation at the plasma membrane. Additionally, BI-69A11 caused increased accumulation of vinculin in the plasma membrane, which fortified focal adhesion junctions leading to inhibition of metastasis. BI-69A11 downregulated activation of the TGF-β-induced non-canonical Akt/NF-κB pathway and blocked TGF-β-induced enhanced expression of Snail causing restoration of E-cadherin. Overall, this study enhances our understanding of the molecular mechanism of BI-69A11-induced reversal of EMT in colorectal carcinoma cells in vitro, in vivo and in TGF-β-induced model systems.

Ovarian Teratoid Carcinosarcoma Is an Aggressive Tumor of Probable Mullerian Derivation with a Carcinosarcomatous and Mixed Germ-Cell Morphology

Ovarian carcinosarcoma is also referred to as malignant mixed Mullerian tumor (MMMT). It is a rare neoplasm, and although it represents less than 5% of malignant ovarian tumors, it remains generally well-known among clinicians and pathologists. Rarer yet is ovarian teratoid carcinosarcoma, defined as carcinosarcoma with the added feature of immature neuroectodermal tissue, with or without elements of primitive germ cell tumor. To our knowledge, six ovarian teratoid carcinosarcomas have been reported in the literature [Matsuura et al. J Obstet Gynaecol Res. 2010 Aug; 36(4): 907-11]. These tumors resemble nasopharyngeal tumors of the same name. We report a 55-year-old woman seen at Orlando Health's division of gynecological oncology whose pathology showed ovarian teratoid carcinosarcoma, and present what we believe to be a seventh report of this entity.

lncRNA GHET1 has effects in development of pre-eclampsia

To explain long noncoding RNA (lncRNA) gastric carcinoma high expressed transcript 1 (GHET1) affects the mechanism in development of pre-eclampsia. The pathological changes of normal, mild, and severe pre-eclampsia were evaluated by hematoxylin and eosin staining and measured the lncRNA GHET1 expression in different tissues by reverse-transcription polymerase chain reaction. In the cell experiment, the BeWo cells were randomly divided into three groups: normal control (NC) group, model group, and lncRNA group. The JEG3 cells of the model and lncRNA groups were cultured in the hypoxia condition. The JEG3 cells invasion and migration abilities were measured by Tanswell and wound-healing assays. The relative protein expressions of different groups were evaluated by Western blot (WB) assay. Compared with normal puerperal, the lncRNA GHET1 gene expression of pre-eclampsia was significantly downregulated (P < 0.05, respectively). In the cell experiment, the invasion cell number and wound-healing rate of the model group were significantly suppressed compared with the NC group (P < 0.05, respectively). However, the invasion cell number and wound-healing rate of lncRNA group were enhanced by lncRNA GHET1 overexpression (P < 0.05, respectively). In WB assay, the E-cadherin, fibronectin, and vimentin proteins expression showed significant differences between the model and lncRNA groups (P < 0.05, respectively). lncRNA GHET1 overexpression had restored cell invasion and migration abilities reduced by hypoxia in pre-eclampsia.

Multi-omics Integration Analysis Robustly Predicts High-Grade Patient Survival and Identifies CPT1B Effect on Fatty Acid Metabolism in Bladder Cancer

PURPOSE

The perturbation of metabolic pathways in high-grade bladder cancer has not been investigated. We aimed to identify a metabolic signature in high-grade bladder cancer by integrating unbiased metabolomics, lipidomics, and transcriptomics to predict patient survival and to discover novel therapeutic targets.

EXPERIMENTAL DESIGN

We performed high-resolution liquid chromatography mass spectrometry (LC-MS) and bioinformatic analysis to determine the global metabolome and lipidome in high-grade bladder cancer. We further investigated the effects of impaired metabolic pathways using in vitro and in vivo models.

RESULTS

We identified 519 differential metabolites and 19 lipids that were differentially expressed between low-grade and high-grade bladder cancer using the NIST MS metabolomics compendium and lipidblast MS/MS libraries, respectively. Pathway analysis revealed a unique set of biochemical pathways that are highly deregulated in high-grade bladder cancer. Integromics analysis identified a molecular gene signature associated with poor patient survival in bladder cancer. Low expression of CPT1B in high-grade tumors was associated with low FAO and low acyl carnitine levels in high-grade bladder cancer, which were confirmed using tissue microarrays. Ectopic expression of the CPT1B in high-grade bladder cancer cells led to reduced EMT in in vitro, and reduced cell proliferation, EMT, and metastasis in vivo.

CONCLUSIONS

Our study demonstrates a novel approach for the integration of metabolomics, lipidomics, and transcriptomics data, and identifies a common gene signature associated with poor survival in patients with bladder cancer. Our data also suggest that impairment of FAO due to downregulation of CPT1B plays an important role in the progression toward high-grade bladder cancer and provide potential targets for therapeutic intervention.