Emodin represses TWIST1-induced epithelial-mesenchymal transitions in head and neck squamous cell carcinoma cells by inhibiting the β-catenin and Akt pathways

Therapeutic Potential of Phytochemicals as Adjuvants in Head and Neck Cancer

Owing to the developments in various therapeutic modalities, cancer treatment has come a long way, including the discovery of various anticancer drugs, innovations in delivery technology, and increased personalization of treatments. Despite this, head and neck cancer (HNC) is a cancer that has eluded the current conventional treatments. To improve quality of life and preserve vital organ function in patients with HNC, there is a need for research into therapeutic regimes that would reduce the toxicity of the current therapeutic modalities. The use of a single approach has not been enough to completely eradicate this malignancy. Therefore, the use of adjuvants and combinatorial approaches, using molecules from natural compounds that have no or minimal side effects, is a growing area of research. One objective of this review was to clarify the potentiality of novel therapeutic strategies for HNC, such as the use of phytochemicals as adjuvants with chemotherapy or radiotherapy, and use of nano-formulation for therapeutic delivery. Another objective of this review was to delineate the associated challenges in the clinical application of these therapies in HNC. Possible strategies for overcoming critical issues associated with the clinical application of phytochemicals for HNC are also discussed.

Multifunctional Bioactivity Electrospinning Nanofibers Encapsulating Emodin Provide a Potential Postoperative Management Strategy for Skin Cancer

Skin cancer is threatening more and more people's health; its postoperative recurrence and wound infection are still critical challenges. Therefore, specialty wound dressings with multifunctional bioactivity are urgently desired. Emodin is a natural anthraquinone compound that has anti-cancer and anti-bacterial properties. Herein, we fabricated coaxial electrospinning nanofibers loaded with emodin to exploit a multifunctional wound dressing for skin cancer postoperative management, which encapsulated emodin in a polyvinylpyrrolidone core layer, combined with chitosan-polycaprolactone as a shell layer. The nanofibers were characterized via morphology, physicochemical nature, drug load efficiency, pH-dependent drug release profiles, and biocompatibility. Meanwhile, the anti-cancer and anti-bacterial effects were evaluated in vitro. The emodin-loaded nanofibers exhibited smooth surfaces with a relatively uniform diameter distribution and a clear shell-core structure; remarkably, emodin was evenly dispersed in the nanofibers with significantly enhanced dissolution of emodin. Furthermore, they not only display good wettability, high emodin entrapment efficiency, and biphasic release profile but also present superior biocompatibility and anti-cancer properties by increasing the levels of MDA and ROS in A-375 and HSC-1 cells via apoptosis-related pathway, and long-term anti-bacterial effects in a dose-independent manner. The findings indicate that the emodin-loaded nanofiber wound dressing can provide a potential treatment strategy for skin cancer postoperative management.

A Narrative Review on CD44's Role in Glioblastoma Invasion, Proliferation, and Tumor Recurrence

High invasiveness is a characteristic of glioblastoma (GBM), making radical resection almost impossible, and thus, resulting in a tumor with inevitable recurrence. GBM recurrence may be caused by glioma stem-like cells (GSCs) that survive many kinds of therapy. GSCs with high expression levels of CD44 are highly invasive and resistant to radio-chemotherapy. CD44 is a multifunctional molecule that promotes the invasion and proliferation of tumor cells via various signaling pathways. Among these, paired pathways reciprocally activate invasion and proliferation under different hypoxic conditions. Severe hypoxia (0.5-2.5% O2) upregulates hypoxia-inducible factor (HIF)-1α, which then activates target genes, including CD44, TGF-β, and cMET, all of which are related to tumor migration and invasion. In contrast, moderate hypoxia (2.5-5% O2) upregulates HIF-2α, which activates target genes, such as vascular endothelial growth factor (VEGF)/VEGFR2, cMYC, and cyclin D1. All these genes are related to tumor proliferation. Oxygen environments around GBM can change before and after tumor resection. Before resection, the oxygen concentration at the tumor periphery is severely hypoxic. In the reparative stage after resection, the resection cavity shows moderate hypoxia. These observations suggest that upregulated CD44 under severe hypoxia may promote the migration and invasion of tumor cells. Conversely, when tumor resection leads to moderate hypoxia, upregulated HIF-2α activates HIF-2α target genes. The phenotypic transition regulated by CD44, leading to a dichotomy between invasion and proliferation according to hypoxic conditions, may play a crucial role in GBM recurrence.

Anti-Cancer Potential of Phytochemicals: The Regulation of the Epithelial-Mesenchymal Transition

A biological process called epithelial-mesenchymal transition (EMT) allows epithelial cells to change into mesenchymal cells and acquire some cancer stem cell properties. EMT contributes significantly to the metastasis, invasion, and development of treatment resistance in cancer cells. Current research has demonstrated that phytochemicals are emerging as a potential source of safe and efficient anti-cancer medications. Phytochemicals could disrupt signaling pathways related to malignant cell metastasis and drug resistance by suppressing or reversing the EMT process. In this review, we briefly describe the pathophysiological properties and the molecular mechanisms of EMT in the progression of cancers, then summarize phytochemicals with diverse structures that could block the EMT process in different types of cancer. Hopefully, these will provide some guidance for future research on phytochemicals targeting EMT.

In vitro and in vivo anti-tumor activity of Coenzyme Q0 against TWIST1-overexpressing HNSCC cells: ROS-mediated inhibition of EMT/metastasis and autophagy/apoptosis induction

HNSCC (Head and Heck Squamous Cell Carcinoma) is a reasonably prevalent cancer with a high mortality rate. In this study, we tried to examine the anti-metastasis and apoptosis/autophagy actions of Coenzyme Q₀ (CoQ₀, 2,3-dimethoxy-5-methyl-1,4-benzoquinone), a derivative of Antrodia camphorata in HNCC TWIST1 overexpressing (FaDu-TWIST1) cells as well as in vivo tumor xenograft mice model. Using fluorescence based cellular assays, western blot and nude mice tumor xenografts, we determined that CoQ₀ effectively reduced cell viability and displayed rapid morphological changes in FaDu-TWIST1 cells compared to FaDu cells. Non/sub-cytotoxic concentrations of CoQ₀ treatment reduces the cell migration by downregulating TWIST1 and upregulating E-cadherin. Apoptosis produced by CoQ₀ was mostly related with caspase-3 activation, PARP cleavage, and VDAC-1 expression. The FaDu-TWIST1 cells treated with CoQ₀ exhibits autophagy-mediated LC3-II accumulation and acidic vesicular organelles (AVOs) formation. Pre-treatment with 3-MA and CoQ effectively prevented CoQ₀-induced cell death and CoQ₀-triggered autophagy in FaDu-TWIST cells as a death mechanism. CoQ₀ induces ROS production in FaDu-TWIST1 cells and NAC pre-treatment significantly reduces anti-metastasis, apoptosis, and autophagy. Likewise, ROS-mediated AKT inhibition regulates CoQ₀-induced apoptosis/autophagy in FaDu-TWIST1 cells. In vivo studies exhibit, CoQ₀ effectively delays and reduces the tumor incidence and burden in FaDu-TWIST1-xenografted nude mice. Current findings display, CoQ₀ exhibits a novel anti-cancer mechanism hence, it might be appropriate for anticancer therapy, and a new potent drug for HNSCC.

Anticancer plant-derivatives: deciphering their oncopreventive and therapeutic potential in molecular terms

Background

Over the years, phytomedicines have been widely used as natural modalities for the treatment and prevention of various diseases by different ethnic groups across the globe. Although, 25% of drugs in the USA contain at least one plant-derived therapeutic compound, currently there is a paucity of plant-derived active medicinal ingredients in the pharmaceutical industry. Scientific evidence-based translation of plant-derived ethnomedicines for their clinical application is an urgent need. The anticancer and associated properties (antioxidative, anti-inflammatory, pro-apoptotic and epithelial-mesenchymal transition (EMT) inhibition) of various plant extracts and phytochemicals have been elucidated earlier. Several of the plant derivatives are already in use under prophylactic/therapeutic settings against cancer and many are being investigated under different phases of clinical trials.

Main body

The purpose of this study is to systematically comprehend the progress made in the area of prophylactic and therapeutic potential of the anticancerous plant derivatives. Besides, we aim to understand their anticancer potential in terms of specific sub-phenomena, such as anti-oxidative, anti-inflammatory, pro-apoptotic and inhibition of EMT, with an insight of the molecules/pathways associated with them. The study also provides details of classes of anticancer compounds, their plant source(s) and the molecular pathway(s) targeted by them. In addition to the antioxidative and antiproliferative potentials of anticancer plant derivatives, this study emphasizes on their EMT-inhibition potential and other ‘anticancer related’ properties. The EMT is highlighted as a phenomenon of choice for targeting cancer due to its role in the induction of metastasis and drug resistance. Different phytochemicals in pre-clinical or clinical trials, with promising chemopreventive/anticancer activities have been enlisted and the plant compounds showing synergistic anticancer activity in combination with the existing drugs have been discussed. The review also unravels the need of carrying out pan-signalome studies for identifying the cardinal pathways modulated by phytomedicine(s), as in many cases, the molecular pathway(s) has/have been randomly studied.

Conclusion

This review systematically compiles the studies regarding the impact of various plant derivatives in different cancers and oncogenic processes, as tested in diverse experimental model systems. Availability of more comprehensive information on anticancer phyto-constituents, their relative abundance in crude drugs, pathways/molecules targeted by phytomedicines, their long-term toxicity data and information regarding their safe use under the combinatorial settings, would open greater avenues of their utilization in future against this dreaded disease.

Graphical Abstract

Twist1 as a target for prevention of cutaneous squamous cell carcinoma

Cutaneous squamous cell carcinoma (cSCC) represents an important clinical problem requiring novel approaches for both prevention and treatment. The transcription factor, Twist-related protein 1 (Twist1), has been identified as having a key mechanistic role in the development and progression of cSCC. Studies in relevant mouse models of cSCC have shown that Twist1 regulates epithelial-mesenchymal transition (EMT) and stemness driving progression and metastasis of cSCC. In addition, further research has shown that Twist1 regulates the balance between keratinocyte proliferation and differentiation and therefore impacts earlier stages of cSCC development. Through use of keratinocyte specific Twist1 knockout models, a role for this gene in keratinocyte stem cell homeostasis has been revealed. As a transcription factor, Twist1 regulates a large number of genes both in a positive, as well as a negative manner across several interdependent pathways. Studies in keratinocyte specific knockout models have shown that Twist1 upregulates the expression of genes involved in proliferation, stemness, and EMT while downregulating the expression of genes associated with differentiation. Furthermore, a number of compounds, including naturally occurring compounds, have been identified that target Twist1 and can block its effects in cancer cells and in keratinocytes in vivo. Collectively, the current understanding of Twist1 function in cSCC development and progression suggests that it represents a potential target for prevention and treatment of cSCC.

Afatinib Reverses EMT via Inhibiting CD44-Stat3 Axis to Promote Radiosensitivity in Nasopharyngeal Carcinoma

BACKGROUND

Afatinib, a second-generation tyrosine kinase inhibitor (TKI), exerts its radiosensitive effects in nasopharyngeal carcinoma (NPC). However, the detailed mechanism of afatinib-mediated sensitivity to radiation is still obscure in NPC.

METHODS

Quantitative phosphorylated proteomics and bioinformatics analysis were performed to illustrate the global phosphoprotein changes. The activity of the CD44-Stat3 axis and Epithelial-Mesenchymal Transition (EMT)-linked markers were evaluated by Western blotting. Wound healing and transwell assays were used to determine the levels of cell migration upon afatinib combined IR treatment. Cell proliferation was tested by CCK-8 assay. A pharmacological agonist by IL-6 was applied to activate Stat3. The xenograft mouse model was treated with afatinib, radiation or a combination of afatinib and radiation to detect the radiosensitivity of afatinib in vivo.

RESULTS

In the present study, we discovered that afatinib triggered global protein phosphorylation alterations in NPC cells. Further, bioinformatics analysis indicated that afatinib inhibited the CD44-Stat3 signaling and subsequent EMT process. Moreover, functional assays demonstrated that afatinib combined radiation treatment remarkably impeded cell viability, migration, EMT process and CD44-Stat3 activity in vitro and in vivo. In addition, pharmacological stimulation of Stat3 rescued radiosensitivity and biological functions induced by afatinib in NPC cells. This suggested that afatinib reversed the EMT process by blocking the activity of the CD44-Stat3 axis.

CONCLUSION

Collectively, this work identifies the molecular mechanism of afatinib as a radiation sensitizer, thus providing a potentially useful combination treatment and drug target for NPC radiosensitization. Our findings describe a new function of afatinib in radiosensitivity and cancer treatment.

Selected Phytochemicals to Combat Lungs Injury: Natural Care

The human has two lungs responsible for respiration and drug metabolism. Severe lung infection caused by bacteria, mycobacteria, viruses, fungi, and parasites may lead to lungs injury. Smoking and tobacco consumption may also produce lungs injury. Inflammatory and pain mediators are secreted by alveolar macrophages. The inflammatory mediators, such as cytokines, interleukin (IL)-1, IL-6, IL-8, IL-10, and tumor necrosis factor (TNF)-α, neutrophils, and fibroblasts are accumulated in the alveoli sac, which becomes infected. It may lead to hypoxia followed by severe pulmonary congestion and the death of the patient. There is an urgent need for the treatment of artificial respiration and ventilation. However, the situation may be the worst for patients suffering from lung cancer, pulmonary tuberculosis, and acute pneumonia caused by acute respiratory distress syndrome (ARDS). Re-urgency has been happening in the case of coronavirus disease of 2019 (COVID-19) patients. Therefore, it is needed to protect the lungs with the intake of natural phytomedicines. In the present review, several selected phyto components having the potential role in lung injury therapy have been discussed. Regular intake of natural vegetables and fruits bearing these constituents may save the lungs even in the dangerous attack of SARS-CoV-2 in lung cancer, pulmonary TB, and pneumatic patients.

Emodin reverses resistance to gemcitabine in pancreatic cancer by suppressing stemness through regulation of the epithelial‑mesenchymal transition

The present study aimed to explore the effects and underlying mechanisms of emodin (Emo) on gemcitabine (GEM)-resistant pancreatic cancer. GEM-resistant SW1990 cells (SW1990/GZ) were established by successively doubling the concentration of GEM. Cell viability was measured using the CCK-8 assay and flow cytometry was used to measure cell apoptosis. Cell migration was assessed using a Transwell assay. Sphere and colony-formation assays were used to evaluate cell self-renewal. The expression levels of epithelial-mesenchymal transition (EMT) and stem cell biomarkers were determined using western blotting. Snail family transcriptional repressor 1 gene (Snail) was overexpressed by transfecting cells with pcDNA3.1-Snail plasmids. A xenograft model was established in nude mice by using SW1990/GZ and Snail-overexpressing SW1990/GZ cells. Proliferation, migration, self-renewal and EMT progression of GEM-treated SW1990/GZ cells were significantly suppressed in vitro by Emo treatment, whereas the overexpression of Snail abolished the aforementioned effects. In in vivo, the antitumor activity of GEM and the inhibitory effect of GEM against EMT progression and stem-like characteristics were enhanced by treatment with Emo, whilst overexpression of Snail reversed these effects. In conclusion, Emo reversed GEM resistance in pancreatic cancer by suppressing stemness and regulating EMT progression.

RBM24 Mediates Lymph Node Metastasis and Epithelial-Mesenchymal Transition in Human Hypopharyngeal Squamous Cell Carcinoma by Regulating Twist1

Objective

Despite the target RNA regulatory action of RBM24 (RNA Binding Motif 24), a protein implicated in multiple carcinomas, its role in HSCC remains unclear. Our study probed to understand the effect of RBM24 on HSCC.

Materials and Methods

A combination of qRT-PCR, IHC, and western blot was employed to assess the HSCC tissue level of RBM24. The colony formation and CCK-8 assays were performed to estimate cellular proliferative potential, whereas the transwell assay was conducted to examine invasive and metastatic potential. The FaDu cell motility was assessed via the scratch-wound assay and EMT (epithelial-mesenchymal transition) by adopting qRT-PCR in conjunction with western blot and IF (immunofluorescence). The in-vivo effect of RBM24 on HSCC was investigated through modeling metastasis to the popliteal LNs (lymph nodes).

Results

Among HSCC patients showing metastasis to LNs, prominent RBM24 downregulation was noted, with an intrinsic association between low RBM24 level and poor outcome. Knocking down RBM24 promoted cell multiplication, migration, and infiltration, while overexpression led to the opposite effects and inhibited the EMT. RBM24's suppressive action against the FaDu cell mobility and invasion was reversed by Twist1 overexpression. RBM24's suppressive actions against the tumor evolution and LN metastasis in HSCC in-vivo were also validated.

Conclusion

As a carcinoma inhibitor gene, RBM24 regulates Twist1 to achieve LN metastasis and EMT suppression in HSCC.

TWIST1 induces proteasomal degradation of β-catenin during the differentiation of ovarian cancer stem-like cells

Ovarian cancer (OC) is one of the leading gynecologic cancers worldwide. Cancer stem-like cells are correlated with relapse and resistance to chemotherapy. Twist1, which is involved in ovarian cancer stem-like cell differentiation, is positively correlated with CTNNB1 in different differentiation stages of ovarian cancer cells: primary epithelial ovarian cancer cells (primary EOC cells), mesenchymal spheroid-forming cells (MSFCs) and secondary epithelial ovarian cancer cells (sEOC cells). However, the expression of β-catenin is inversed compared to CTNNB1 in these 3 cell states. We further demonstrated that β-catenin is regulated by the protein degradation system in MSFCs and secondary EOC but not in primary EOC cells. The differentiation process from primary EOC cells to MSFCs and sEOC cells might be due to the downregulation of β-catenin protein levels. Finally, we found that TWIST1 can enhance β-catenin degradation by upregulating Axin2.

The Comparison of the Efficiency of Emodin and Aloe-Emodin in Photodynamic Therapy

Skin cancer (melanoma and non-melanoma) is the most frequent type of malignancy in the Caucasian population. Photodynamic therapy (PDT) as an interesting and unique strategy may potentially boost standard therapeutic approaches. In the present study, the potential of emodin and aloe-emodin as photosensitizers in photodynamic therapy has been investigated. The conducted research presents for the first-time comparison of the phototoxic and anti-cancerous effects of emodin and aloe-emodin on skin cancer cell lines, including SCC-25 representing cutaneous squamous cell carcinoma, MUG-Mel2 representing a melanoma cell line, and normal human keratinocytes HaCaT representing control normal skin cells. To assess the effectiveness of emodin and aloe-emodin as a photosensitizer in PDT on different skin cell lines, we performed MTT assay measuring cytotoxicity of natural compounds, cellular uptake, apoptosis with flow cytometry, and a wound-healing assay. Although emodin and aloe-emodin are isomers and differ only in the position of one hydroxyl group, our phototoxicity and apoptosis detection results show that both substances affect skin cancer cells (SSC-25 squamous cell carcinoma and MUG-Mel2 melanoma) and normal keratinocytes (HaCaT cell line) in other ways. In conclusion, our study provides evidence suggesting that emodin and aloe-emodin mediated PDT exhibits the potential for clinical development as a new effective and safe photosensitizer to treat skin cancer.

Pharmacokinetics, Tissue Distribution, and Excretion Characteristics of a Radix Polygoni Multiflori Extract in Rats

Although progress has been achieved in the pharmacological activity and toxicity of Radix Polygoni Multiflori (RPM), the chemical basis of its toxicity is still unclear. Here, we performed a multicompound pharmacokinetic analysis and investigated the tissue distribution and excretion characteristics of RPM components after oral administration in rats. The findings demonstrated that the active ingredients of the RPM extract were quickly absorbed after oral administration, with high exposure levels of emodin, 2,3,5,4'-teterahydroxystilbene-2-O-β-D-glucoside (TSG), citreorosein, torachrysone-8-O-glucoside (TG), emodin-8-O-β-D-glucoside (EG), and physcion-8-O-β-D-glucoside (PG). The tissue distributions of emodin, TSG, TG, EG, and PG were high in the liver and kidney. These components were the key contributors to the effectiveness and toxicity of RPM on the liver and kidney. Most of the active ingredients were mainly excreted through feces and bile, while a few were converted into other products in the body and excreted through urine and feces.

Cancer Chemoprevention: A Strategic Approach Using Phytochemicals

Cancer chemoprevention approaches are aimed at preventing, delaying, or suppressing tumor incidence using synthetic or natural bioactive agents. Mechanistically, chemopreventive agents also aid in mitigating cancer development, either by impeding DNA damage or by blocking the division of premalignant cells with DNA damage. Several pre-clinical studies have substantiated the benefits of using various dietary components as chemopreventives in cancer therapy. The incessant rise in the number of cancer cases globally is an issue of major concern. The excessive toxicity and chemoresistance associated with conventional chemotherapies decrease the success rates of the existent chemotherapeutic regimen, which warrants the need for an efficient and safer alternative therapeutic approach. In this scenario, chemopreventive agents have been proven to be successful in protecting the high-risk populations from cancer, which further validates chemoprevention strategy as rational and promising. Clinical studies have shown the effectiveness of this approach in managing cancers of different origins. Phytochemicals, which constitute an appreciable proportion of currently used chemotherapeutic drugs, have been tested for their chemopreventive efficacy. This review primarily aims to highlight the efficacy of phytochemicals, currently being investigated globally as chemopreventives. The clinical relevance of chemoprevention, with special emphasis on the phytochemicals, curcumin, resveratrol, tryptanthrin, kaempferol, gingerol, emodin, quercetin genistein and epigallocatechingallate, which are potential candidates due to their ability to regulate multiple survival pathways without inducing toxicity, forms the crux of this review. The majority of these phytochemicals are polyphenols and flavanoids. We have analyzed how the key molecular targets of these chemopreventives potentially counteract the key drivers of chemoresistance, causing minimum toxicity to the body. An overview of the underlying mechanism of action of these phytochemicals in regulating the key players of cancer progression and tumor suppression is discussed in this review. A summary of the clinical trials on the important phytochemicals that emerge as chemopreventives is also incorporated. We elaborate on the pre-clinical and clinical observations, pharmacokinetics, mechanism of action, and molecular targets of some of these natural products. To summarize, the scope of this review comprises of the current status, limitations, and future directions of cancer chemoprevention, emphasizing the potency of phytochemicals as effective chemopreventives.

Epithelial-to-Mesenchymal Transition-Derived Heterogeneity in Head and Neck Squamous Cell Carcinomas

Simple Summary

Head and neck squamous cell carcinomas (HNSCC) are common malignancies with considerable morbidity and a high death toll worldwide. Resistance towards multi-modal therapy modalities composed of surgery, irradiation, chemo- and immunotherapy represents a major obstacle in the efficient treatment of HNSCC patients. Patients frequently show nodal metastases at the time of diagnosis and endure early relapses, oftentimes in the form of local recurrences. Differentiation programs such as the epithelial-to-mesenchymal transition (EMT) allow individual tumor cells to adopt cellular functions that are central to the development of metastases and treatment resistance. In the present review article, the molecular basis and regulation of EMT and its impact on the progression of HNSCC will be addressed.

Abstract

Head and neck squamous cell carcinomas (HNSCC) are common tumors with a poor overall prognosis. Poor survival is resulting from limited response to multi-modal therapy, high incidence of metastasis, and local recurrence. Treatment includes surgery, radio(chemo)therapy, and targeted therapy specific for EGFR and immune checkpoint inhibition. The understanding of the molecular basis for the poor outcome of HNSCC was improved using multi-OMICs approaches, which revealed a strong degree of inter- and intratumor heterogeneity (ITH) at the level of DNA mutations, transcriptome, and (phospho)proteome. Single-cell RNA-sequencing (scRNA-seq) identified RNA-expression signatures related to cell cycle, cell stress, hypoxia, epithelial differentiation, and a partial epithelial-to-mesenchymal transition (pEMT). The latter signature was correlated to nodal involvement and adverse clinical features. Mechanistically, shifts towards a mesenchymal phenotype equips tumor cells with migratory and invasive capacities and with an enhanced resistance to standard therapy. Hence, gradual variations of EMT as observed in HNSCC represent a potent driver of tumor progression that could open new paths to improve the stratification of patients and to innovate approaches to break therapy resistance. These aspects of molecular heterogeneity will be discussed in the present review.

Discovery of Pyrrole-imidazole Polyamides as PD-L1 Expression Inhibitors and Their Anticancer Activity via Immune and Nonimmune Pathways

In recent years, PD-1 immune checkpoint inhibitors based on monoclonal antibodies have revolutionized cancer therapy, but there still exist unresolved issues, such as the high cost, the relatively low response rates, and so on, compared with small-molecule drugs. Herein a type of pyrrole-imidazole (Py-Im) polyamide as a small-molecule DNA binder was designed and synthesized, which could competitively bind to the same double-stranded DNA stretch in the PD-L1 promoter region as the STAT3 binding site and thus downregulate PD-L1 expression. It was demonstrated that the Py-Im polyamides directly caused apoptosis in tumor cells and retarded cell migration in the absence of T cells through inhibiting the Akt/caspase-3 pathway. Also, in a coculture system, they enhanced the T-cell-mediated killing of tumor cells by the reversal of immune escape. Because such polyamides induced antitumor effects via both immune and nonimmune pathways, they could be further developed as promising PD-L1 gene-targeting antitumor drugs.

Emodin-induced autophagic cell death hinders epithelial-mesenchymal transition via regulation of BMP-7/TGF-β1 in renal fibrosis

We aim to explore the effects of emodin and its mechanisms on renal fibrosis (RF). We firstly modeled adriamycin-induced rat RF with unilateral nephrectomy. In vivo and in vitro pharmacological experiments were performed in this study. The presence of collagen deposition was detected by Masson staining. To verify whether emodin attenuates RF by monitoring autophagy, the immunohistochemistry staining for autophagy protein LC3B was performed. We conducted western blot to detect the expression of the autophagy-related proteins in EMT in vitro model after treating with emotin and BMP-7. In vivo, we demonstrated that emodin could improve renal dysfunction and decrease pathological damage of the kidney by activation of autophagy and inhibition of EMT. Upregulation of BMP-7 was recorded in the RF rats subjected to emodin treatment. In vitro studies, emodin has the capacity of reversing EMT and activating autophagy, and emodin could regulate the expression of BMP-7. The results revealed that the attenuation of EMT by emodin could be blocked after the inhibition of BMP-7 and suppression of autophagy. Our findings demonstrated that emodin alleviates EMT during RF by actuating autophagy through BMP-7, suggesting a role of BMP-7 in RF treatment and prevention.

Natural products remodel cancer-associated fibroblasts in desmoplastic tumors

Desmoplastic tumors have an abundance of stromal cells and the extracellular matrix which usually result in therapeutic resistance. Current treatment prescriptions for desmoplastic tumors are usually not sufficient to eliminate the malignancy. Recently, through modulating cancer-associated fibroblasts (CAFs) which are the most abundant cell type among all stromal cells, natural products have improved chemotherapies and the delivery of nanomedicines to the tumor cells, showing promising ability to improve treatment effects on desmoplastic tumors. In this review, we discussed the latest advances in inhibiting desmoplastic tumors by modeling CAFs using natural products, highlighting the potential therapeutic abilities of natural products in targeting CAFs for cancer treatment.

LGR6 Promotes Tumor Proliferation and Metastasis through Wnt/β-Catenin Signaling in Triple-Negative Breast Cancer

Leucine-rich-repeat-containing G protein-coupled receptor 6 (LGR6) has been identified as the stem cell marker in multiple normal tissues and malignancies. Previous studies implicated paradoxical functions of LGR6 as a tumor-suppressor gene or oncogene given to the specific context. To explore the exact role of LGR6 in triple-negative breast cancer (TNBC) that never has been studied before, in this study, we assessed LGR6 expression levels by RT-PCR and immunohistochemistry. LGR6 stable expressing/silenced cells were established, and functional assays on tumor proliferation, as well as metastasis, were conducted both in vitro and in vivo. Here, we found that LGR6 was overexpressed in TNBC, which correlated with poor disease-free and overall survivals. Functional assays both in vitro and in vivo showed that LGR6 promotes tumor proliferation and metastasis. LGR6 also increased the ability of tumor spheroid formation. Underlying mechanism exploration further revealed that the oncogenic role of LGR6 might be associated with the Wnt/β-catenin pathway. In conclusion, our findings first proved that LGR6 acts as an oncogene in (TNBC), indicating that LGR6 might be a potential therapeutic target for TNBC treatment.

Emodin Reverses the Epithelial-Mesenchymal Transition of Human Endometrial Stromal Cells by Inhibiting ILK/GSK-3β Pathway

Purpose

To explore the exact mechanism through which emodin down-regulates the migration and invasion abilities of endometrial stromal cells. Moreover, to explore the theoretical basis of emodin in the treatment of endometriosis.

Patients and Methods

Endometriosis endometrial stromal cells (EESs) were cultured from 15 women with endometriosis and control endometrial stromal cells (CESs) were cultured from 12 women without endometriosis. The levels of proteins were evaluated by Western blot. The migration and invasion abilities of cells were detected by transwell assays.

Results

The abilities of migration and invasion of EESs were much stronger than those of CESs. After treated with emodin, the migration and invasion abilities of EESs and CESs were significantly down-regulated, and the levels of integrin-linked kinase (ILK) and p-GSK-3β were statistically down-regulated in EESs. Besides that, the expression of keratin was up-regulated while the expression of vimentin, β-catenin and slug were all down-regulated by emodin in a dose- and time-dependent manner. Silencing of ILK gene in EESs also achieved the above effects, which were strengthened by emodin. Conversely, exogenous expression of ILK in CESs increased the expression of p-GSK-3β, which were abrogated by emodin. Furthermore, SB216763 increased migration and invasion abilities of CESs by facilitating the epithelial-mesenchymal transition (EMT) through up-regulating levels of p-GSK-3β, β-catenin and slug, which were also abrogated by emodin.

Conclusion

Emodin inhibits the migration and invasion abilities of human endometrial stromal cells by reversing the EMT via ILK/GSK-3β pathway. So, emodin may be considered as a promising targeted therapy for endometriosis.

Emodin Alleviates Hydrogen Peroxide-Induced Inflammation and Oxidative Stress via Mitochondrial Dysfunction by Inhibiting the PI3K/mTOR/GSK3β Pathway in Neuroblastoma SH-SY5Y Cells

Emodin is an active monomer extracted from rhubarb root, which has many biological functions, including anti-inflammation, antioxidation, anticancer, and neuroprotection. However, the protective effect of emodin on nerve injury needs to be further elucidated. The purpose of this study is to investigate the effect of emodin on the neuroprotection and the special molecular mechanism. Here, the protective activity of emodin inhibiting H2O2-induced apoptosis and neuroinflammation as well as its molecular mechanisms was examined using human neuroblastoma cells (SH-SY5Y cells). The results showed that emodin significantly enhanced cell viability, reduced cell apoptosis and LDH release. Simultaneously, emodin downregulated H2O2-induced inflammatory factors, including IL-6, NO, and TNF-α, and alleviated H2O2-induced oxidative stress and mitochondrial dysfunction in SH-SY5Y cells. In addition, emodin inhibited the activation of the PI3K/mTOR/GSK3β signaling pathway. What is more, the PI3K/mTOR/GSK3β pathway participated in the protective mechanism of emodin on H2O2-induced cell damage. Collectively, it suggests that emodin alleviates H2O2-induced apoptosis and neuroinflammation potentially by regulating the PI3K/mTOR/GSK3β signaling pathway.

The Significance of the Dysregulation of Canonical Wnt Signaling in Head and Neck Squamous Cell Carcinomas

The knowledge about the molecular alterations which are found in head and neck squamous cell carcinomas (HNSCC) has much increased in recent years. However, we are still awaiting the translation of this knowledge to new diagnostic and therapeutic options. Among the many molecular changes that are detected in head and neck cancer, the abnormalities in several signaling pathways, which regulate cell proliferation, cell death and stemness, seem to be especially promising with regard to the development of targeted therapies. Canonical Wnt signaling is a pathway engaged in the formation of head and neck tissues, however it is not active in adult somatic mucosal cells. The aim of this review paper is to bring together significant data related to the current knowledge on the mechanisms and functional significance of the dysregulation of the Wnt/β-catenin pathway in head and neck tumors. Research evidence related to the role of Wnt signaling activation in the stimulation of cell proliferation, migration and inhibition of apoptosis in HNSCC is presented. Moreover, its role in promoting stemness traits in head and neck cancer stem-like cells is described. Evidence corroborating the hypothesis that the Wnt signaling pathway is a very promising target of novel therapeutic interventions in HNSCC is also discussed.

Interaction of polyphenols extract from Polygonum multiflorum Thunb. roots with gelatin and toxicity of extract in mice

The roots of Polygonum multiflorum Thunb. (Vietnamese name: Ha-thu-o-do, HTOD) are used in processed form or the raw state in traditional Vietnamese medicine for many diseases and in extract form in the food industry. Some studies pointed out that HTOD extract had toxicity in humans. However, the toxicity of this herb plant currently remains unclear. In addition, this material contained a large amount of bioactive compounds, especially phenolic compounds. They have a strong antioxidant capacity and they can also interact with many different substrates such as protein, enzyme, lipid and carbohydrate. In this study, the received extracts from HTOD had the polyphenols concentrations of 415, 277, 208 and 166 (mg GAE.L-1), respectively. Besides, we only evaluated the gelatin-polyphenols interaction and the toxicity of HTOD extract in Swiss mice. The results show a strong gelatin-polyphenols interaction and no acute or subacute toxicity in mice. The polyphenols extract of HTOD at the concentration tested in this study is safe to use in food.

Anticancer activity of emodin is associated with downregulation of CD155

Emodin is a Chinese herb-derived compound that exhibits a variety of pharmacological benefits. Although emodin has been shown to inhibit growth of cancer cells, its antineoplastic function is incompletely understood. CD155 is a member of poliovirus receptor-related (PRR) family of adhesion molecules; it is constitutively expressed on many tumor cell lines and tissues and has diverse functions. CD155 has been reported to mediate activation of T cells via CD226 or inhibition of T cells via T-cell immunoreceptor with Ig and ITIM domains (TIGIT). In addition, CD155 may play a critical role through non-immunological mechanisms in cancer. In this study, we tested the ability of emodin to modulate CD155 expression in cancer cells. We found that emodin significantly decreased the expression of CD155 in tumor cells and inhibited tumor cell proliferation and migration, and induced cell-cycle arrest at G2/M phase. The tumor inhibitory effects of emodin were lost with CD155 knockdown. Furthermore, emodin was used to treat mice bearing B16 melanoma. It was shown that emodin attenuated tumor growth accompanied by suppressing CD155 expression. Therefore, we propose that emodin could inhibit tumor growth, and the antineoplastic properties of emodin are at least partially CD155 dependent. Our study provides new insights into the mechanisms by which emodin inhibits tumor growth.

Overcoming acquired resistance of gefitinib in lung cancer cells without T790M by AZD9291 or Twist1 knockdown in vitro and in vivo

The T790M mutation is recognized as a typical mechanism of acquired resistance to first generation of epithermal growth factor receptor-tyrosine kinase inhibitors (EGFR-TKIs) such as gefitinib in non-small cell lung cancer (NSCLC) patients who are commonly treated by third generation of EGFR-TKI AZD9291 (osimertinib). However, the therapeutic strategy for overcoming acquired resistance to EGFR-TKIs in NSCLC patients without T790M remains to be definitively determined. In the present study, gefitinib-resistant H1650 (H1650GR) or AZD9291-resistant H1975 (H1975AR) was generated by exposing NSCLC cell line H1650 or H1975 to progressively increased concentrations of gefitinib or AZD9291 over 11 months. The cytotoxic effects of gefitinib or AZD9291 in vitro were evaluated via the half maximal inhibitory concentrations (IC50s) determined by the MTT assay. IC50 of gefitinib in H1650GR (50.0 ± 3.0 µM) significantly increased compared with H1650 (31.0 ± 1.0 µM) (p < 0.05). Similarly, the IC50 of AZD9291 in H1975AR (10.3 ± 0.9 µM) significantly increased compared with H1975 (5.5 ± 0.6 µM) (p < 0.05). However, IC50 of AZD9291 on H1650GR (8.5 ± 0.5 µM) did not increase compared with H1650 (9.7 ± 0.7 µM). On the other hand, IC50 of AZD9291 on gefitinib-resistant A549 (A549GR established in our previous study) (12.7 ± 0.8 µM) was significantly increased compared with A549 (7.0 ± 1.0 µM) (p < 0.05). AZD9291 induced caspase 3/7 activation in A549, H1650, and H1650GR, but not in A549GR. Western blot analyses showed that p-Akt played a key role in determining the sensitivities of A549, A549GR, H1650, and H1650GR to gefitinib or AZD9291. Additionally, increased expression of Twist1 was observed in all cells with acquired EGFR-TKI resistance and knockdown of Twist1 by shRNA was found to significantly enhance the sensitivity of A549GR to gefitinib or AZD9291 via reversing epithelial-mesenchymal transition and downregulating p-Akt, but not of H1975AR to AZD9291. The enhanced cytotoxic effect of AZD9291 on A549GR by Twist1 knockdown in vitro was further validated by in vivo studies which showed that Twist1 knockdown could lead to significantly delayed tumor growth of A549GR xenograft with increased sensitivity to AZD9291 treatment in nude mice without any observed side toxic effects. In summary, our study demonstrated that the mechanisms of acquired resistance in different NSCLC cell lines treated by even the same EGFR-TKI might be quite different, which provide a rationale for adopting different therapeutic strategies for those NSCLC patients with acquired EGFR-TKI resistance based on different status of heterogeneous mutations.

Emodin Inhibits Colon Cancer Cell Invasion and Migration by Suppressing Epithelial-Mesenchymal Transition via the Wnt/β-Catenin Pathway

Colon cancer (CC) is the third most common cancer worldwide. Emodin is an anthraquinone-active substance that has the ability to affect tumor progression. Our study aims to explore the effects and the relevant mechanism of emodin on the invasion and migration of CC in vitro and in vivo. In our study, we found that emodin inhibited the invasion and migration abilities of RKO cells and decreased the expression of matrix metalloproteinase-7 (MMP-7), MMP-9, and vascular endothelial growth factor (VEGF) in a dose-dependent manner. Further research suggested that emodin inhibited EMT by increasing the mRNA level of E-cadherin and decreasing the expression of N-cadherin, Snail, and β-catenin. Emodin also significantly inhibited the activation of the Wnt/β-catenin signaling pathway by downregulating the expression of related downstream target genes, including TCF4, cyclin D1, and c-Myc. A Wnt/β-catenin signaling pathway agonist abolished the effect of emodin on EMT and cell mobility, suggesting that emodin exerted its regulating role through the Wnt/β-catenin pathway. The CC xenograft model was established to study the antitumor efficiency of emodin in vivo. The in vivo study further demonstrated that emodin (40 mg/kg) suppressed tumor growth by inhibiting EMT via the Wnt/β-catenin signaling pathway in vivo. Taken together, we suggest that emodin inhibits the invasion and migration of CC cells in vitro and in vivo by blocking EMT, which is related with the inhibition of the Wnt/β-catenin signaling pathway.

Dietary phytochemicals in the regulation of epithelial to mesenchymal transition and associated enzymes: A promising anticancer therapeutic approach

Epithelial to mesenchymal transition (EMT) is a biological phenomenon that plays a primordial role for initiation of metastasis. It renders cancer cells with increased self-renewal and tumor-initiating capabilities and exacerbated resistance to apoptosis and chemotherapy. Hence, regulation of EMT stands out to be an important strategy in controlling the behavior of malignant cells. Despite the enormous amount of preclinical data on the implication of EMT in cancer progression, there is still lack of routine clinical translation at therapeutic levels. The need of EMT-modulating drugs with high efficacy and low cytotoxicity has led to studies involving the evaluation of the efficacy of a plethora of various classes of phytochemicals present in dietary sources of fruits and vegetables. This review summarizes the role of these different classes of phytochemicals, their natural/synthetic analogs, and their nano-formulations in regulation of EMT in various preclinical models through attenuation of primary signaling pathways. Numerous proteins, transcription factors and enzymes targeted by various classes of phytochemicals in repression of EMT has been presented in this review. Additionally, we have critically analyzed the existing literature and provided views on new direction for accelerating the discovery of novel drug candidates which could be cautiously administered without concomitant effects.

Emodin alleviates CCl4‑induced liver fibrosis by suppressing epithelial‑mesenchymal transition and transforming growth factor‑β1 in rats

Liver fibrosis is a chronic disease that exhibits a complicated pathophysiology. It is characterized by the deposition of the extracellular matrix. Emodin, an active constituent isolated from rhubarb, has antibacterial, immunosuppressive and anti-inflammatory effects. In the present study, the mechanism through which emodin alleviates liver fibrosis in rats was investigated. A rat model of liver fibrosis was generated by administering CCl₄ via subcutaneous injection twice a week for 12 weeks. Emodin or sodium carboxymethylcellulose (CMC), as the vehicle, were intragastrically administered daily. After 12 weeks, the liver function index was examined by blood analysis, histopathological scores of fibrosis was determined by hematoxylin and eosin staining and level of collagen deposition was examined by Masson staining. In addition, protein and RNA samples were collected for further analysis. The results of the present study revealed that emodin significantly reduced the liver function index and level of collagen deposition in a dose-dependent manner. Furthermore, emodin reduced the expression of transforming growth factor-β1 (TGF-β1) and the phosphorylation levels of mothers against decapentaplegic homolog 2/3, and inhibited the CCl₄-induced downregulation of E-cadherin and upregulation of the mesenchymal markers, fibronectin and vimentin. The expression levels of TGF-β1, Snail family transcriptional repressor (Snail) 2, Snail, twist-related protein 1 and zinc finger E-box-binding homeobox (ZEB)1 and 2 mRNA were significantly decreased in emodin-treated groups compared with the untreated control. Collectively, the results of the present study suggested that emodin may exert antifibrotic effects via the suppression of TGF-β1 signaling and epithelial-mesenchymal transition.

Twist1-induced epithelial-mesenchymal transition according to microsatellite instability status in colon cancer cells

Colorectal cancer (CRC) with microsatellite instability (MSI) may exhibit impaired epithelial-mesenchymal transition (EMT), but little is known about the underlying mechanisms of this phenomenon. In this study, we investigated the role of Twist1 and its downstream signaling cascades in EMT induction according to MSI status. To investigate the effects of Twist1 on EMT induction according to MSI status, MSS LS513 and MSI LoVo colon cancer cell lines, which overexpress human Twist1, were generated. Twist1-induced EMT and its downstream signaling pathways were evaluated via in vitro and in vivo experiments. We found that Twist1 induced EMT markers and stem cell-like characteristics via AKT signaling pathways. Twist1 induced activation of AKT and suppression of glycogen synthase kinase (GSK)-3β, which resulted in the activation of β-catenin, increasing CD44 expression. In addition, Twist1 activated the AKT-induced NF-κB pathway, increasing CD44 and CD166 expression. Activation of both the AKT/GSK-3β/β-catenin and AKT/NF-κB pathways occurred in MSS LS513 cells, while only the AKT/GSK-3β/β-catenin pathway was activated in MSI LoVo cells. In conclusion, Twist1 induces stem cell-like characteristics in colon cancer cell lines related to EMT via AKT signaling pathways, and those pathways depend on MSI status.

Activated CXCL5-CXCR2 axis promotes the migration, invasion and EMT of papillary thyroid carcinoma cells via modulation of β-catenin pathway

Initiation of epithelial-to-mesenchymal transition (EMT) is common in papillary thyroid carcinoma (PTC) and may contribute to its metastasis. Aims of the present study are to investigate whether and how the C-X-C motif chemokine ligand (CXCL)-5/C-X-C motif receptor 2 (CXCR2) axis affects PTC metastasis, with a focus on the EMT process. Herein, two PTC cell lines, KTC-1 and B-CPAP cells, identified as CXCR2-positive cells were used as the cell model. We found that a 24-h stimulation of 1 or 10 nM recombinant human CXCL5 (rhCXCL5) enhanced the migration and invasion of both KTC-1 and B-CPAP cells without affecting their proliferation. The migration- and invasion-promoting effects of rhCXCL5 were attenuated if CXCR2 was silenced by its specific short hairpin RNAs (shRNAs). EMT initiation is defined as downregulation of epithelial-cadherin (E-cadherin) and upregulation of N-cadherin, Vimentin and Snail. Our data showed that rhCXCL5-induced EMT in PTC cells was suppressed by CXCR2 shRNA. Furthermore, the active CXCL5-CXCR2 axis enhanced the phosphorylation of Akt at Ser 473 residue and that of glycogen synthase kinase-3 (GSK-3β) at Ser 9 residue, and accelerated the nuclear accumulation of β-catenin in PTC cells. Re-expression of the active form of β-catenin in PTC cells rescued their impaired invasiveness caused by the blockade of CXCL5-CXCR2 axis. In addition, CXCL5 and CXCR2 were overexpressed in the metastatic lymph nodes obtained from 18 patients with PTC. In summary, our study demonstrates that the activated CXCL5-CXCR2 axis contributes to the metastatic phenotype of PTC cells by modulating Akt/GSK-3β/β-catenin pathway.

Aloe-emodin inhibits HER-2 expression through the downregulation of Y-box binding protein-1 in HER-2-overexpressing human breast cancer cells

Human epidermal growth factor receptor-2 (HER-2)-positive breast cancer tends to be aggressive, highly metastatic, and drug resistant and spreads rapidly. Studies have indicated that emodin inhibits HER-2 expression. This study compared the HER-2-inhibitory effects of two compounds extracted from rhubarb roots: aloe-emodin (AE) and rhein. Our results indicated that AE exerted the most potent inhibitory effect on HER-2 expression. Treatment of HER-2-overexpressing breast cancer cells with AE reduced tumor initiation, cell migration, and cell invasion. AE was able to suppress YB-1 expression, further suppressing downstream HER-2 expression. AE suppressed YB-1 expression through the inhibition of Twist in HER-2-overexpressing breast cancer cells. Our data also found that AE inhibited cancer metastasis and cancer stem cells through the inhibition of EMT. Interestingly, AE suppressed YB-1 expression through the downregulation of the intracellular integrin-linked kinase (ILK)/protein kinase B (Akt)/mTOR signaling pathway in HER-2-overexpressing breast cancer cells. In vivo study showed the positive result of antitumor activity of AE in nude mice injected with human HER-2-overexpressing breast cancer cells. These findings suggest the possible application of AE in the treatment of HER-2-positive breast cancer.

CD44/CD44v6 a Reliable Companion in Cancer-Initiating Cell Maintenance and Tumor Progression

Metastasis is the leading cause of cancer death, tumor progression proceeding through emigration from the primary tumor, gaining access to the circulation, leaving the circulation, settling in distant organs and growing in the foreign environment. The capacity of a tumor to metastasize relies on a small subpopulation of cells in the primary tumor, so called cancer-initiating cells (CIC). CIC are characterized by sets of markers, mostly membrane anchored adhesion molecules, CD44v6 being the most frequently recovered marker. Knockdown and knockout models accompanied by loss of tumor progression despite unaltered primary tumor growth unraveled that these markers are indispensable for CIC. The unexpected contribution of marker molecules to CIC-related activities prompted research on underlying molecular mechanisms. This review outlines the contribution of CD44, particularly CD44v6 to CIC activities. A first focus is given to the impact of CD44/CD44v6 to inherent CIC features, including the crosstalk with the niche, apoptosis-resistance, and epithelial mesenchymal transition. Following the steps of the metastatic cascade, we report on supporting activities of CD44/CD44v6 in migration and invasion. These CD44/CD44v6 activities rely on the association with membrane-integrated and cytosolic signaling molecules and proteases and transcriptional regulation. They are not restricted to, but most pronounced in CIC and are tightly regulated by feedback loops. Finally, we discuss on the engagement of CD44/CD44v6 in exosome biogenesis, loading and delivery. exosomes being the main acteurs in the long-distance crosstalk of CIC with the host. In brief, by supporting the communication with the niche and promoting apoptosis resistance CD44/CD44v6 plays an important role in CIC maintenance. The multifaceted interplay between CD44/CD44v6, signal transducing molecules and proteases facilitates the metastasizing tumor cell journey through the body. By its engagement in exosome biogenesis CD44/CD44v6 contributes to disseminated tumor cell settlement and growth in distant organs. Thus, CD44/CD44v6 likely is the most central CIC biomarker.

Emodin Attenuates Bleomycin-Induced Pulmonary Fibrosis via Anti-Inflammatory and Anti-Oxidative Activities in Rats

BACKGROUND Idiopathic pulmonary fibrosis (IPF) can severely damage lung function, which may result in death. Emodin is a major ingredient of rhubarb and has been proven to protect against lung disruptions. Our study focused on the potential medicinal effect of emodin against IPF. MATERIAL AND METHODS The experiment subjects were fully-grown male Sprague-Dawley rats with average weight of 180-220 kg. Histological analyses, Western blotting analysis, quantitative real-time PCR, and statistical analysis were used in the study. RESULTS We found that emodin significantly reduced lung structural distortion, collagen overproduction, massive inflammatory cells infiltration, proinflammatory cytokines expansion, and injuries caused by administration of bleomycin (BLM). Additionally, emodin suppressed the accumulation of p-IκBα and NF-κB, while stimulating the Nrf2-antioxidant signaling process in damaged lungs. Emodin inhibited epithelial-mesenchymal transition (EMT) induced by BLM in the lungs. Moreover, emodin suppressed the TGF-β1 expression and the downstream signal molecules p-Smad-2 and p-Smad-3, which are reinforced by BLM. Emodin can also reverse EMT-like shifts induced by recombinant TGF-β1 in alveolar epithelial cultured cells. CONCLUSIONS The effect of emodin in fibrotic lung injury is closely related to its favorable properties of anti-inflammation and anti-oxidation.

TRAF4 Regulates Migration, Invasion, and Epithelial-Mesenchymal Transition via PI3K/AKT Signaling in Hepatocellular Carcinoma

Overexpression of the tumor necrosis factor receptor-associated factor 4 (TRAF4) has been detected in many cancer types and is considered to foster tumor progression. However, the role of TRAF4 in hepatocellular carcinoma (HCC) remains elusive. In this study, we found that TRAF4 was highly expressed in HCC cell lines and HCC tissues compared with normal liver cell lines and adjacent noncancerous tissues. TRAF4 overexpression in HCC tissues was correlated with tumor quantity and vascular invasion. In vitro studies showed that TRAF4 was associated with HCC cell migration and invasion. An in vivo study verified that TRAF4 overexpression facilitated metastasis in nude mice. In addition, overexpressed TRAF4 promoted the phosphorylation of Akt and induced Slug overexpression, leading to downregulated E-cadherin and upregulated vimentin, while silencing TRAF4 moderated the phosphorylation of Akt and repressed the expression of Slug, which resulted in upregulated E-cadherin and downregulated vimentin. These effects were inversed after pretreatment of the PI3K/Akt inhibitor LY294002 or overexpression of constitutively active Akt1. Our study demonstrated that TRAF4 was involved in promoting HCC cell migration and invasion. The process was induced by the EMT through activation of the PI3K/Akt signaling pathway.

Emodin suppresses proliferation, migration and invasion in ovarian cancer cells by down regulating ILK in vitro and in vivo

OBJECTIVE

Although our previous studies have confirmed that 1, 3, 8-trihydroxy-6-methylant hraquinone (emodin) inhibits migration and invasion in epithelial ovarian cancer (EOC) cells, the underlying molecular mechanism remains unknown. Here, the aim was to investigate the effects of emodin on EOC cells and to study further the mechanism underlying this process, both in vitro and in vivo.

MATERIALS AND METHODS

Cell proliferation was evaluated by the methylthiazolyl tetrazolium assay. Cell migration and invasion abilities were tested using the transwell assay. The expression of integrin-linked kinase (ILK) and epithelial-mesenchymal transition (EMT)-associated factors were measured with western blotting.

RESULTS

Exogenous ILK enhanced the proliferation, migration and invasion properties of A2780 and SK-OV-3 cells. After treatment with emodin, the survival rate of cells was gradually reduced, including those of SK-OV-3/pLVX-ILK and A2780/pLVX-ILK cells, with increasing emodin concentrations. The migration and invasion abilities of A2780 and SK-OV-3 cells were effectively increased by the transfection of pLVX-ILK, which could be abrogated by following this with 48 hours of emodin treatment. Treatment with emodin significantly downregulated the expression of ILK and EMT-related proteins. So, emodin suppressed proliferation, migration and invasion in ovarian cancer cells by downregulating ILK in vitro. SK-OV-3/pLVX-Con and SK-OV-3/pLVX-ILK cells were used to generate xenografts in nude mice. Tumors grew more rapidly in the SK-OV-3/pLVX-ILK group compared with the control group, and this could be significantly inhibited by emodin. Also, the expression of E-cadherin was downregulated, while the expression of Slug, MMP-9 and Vimentin were upregulated in the SK-OV-3/pLVX-ILK group, and this could be reversed by following treatment with emodin. Emodin did not demonstrate target toxicity on hepatocytes, nephrocytes and cardiomyocytes.

CONCLUSION

Emodin suppresses proliferation, migration and invasion in ovarian cancer by targeting ILK.

E-Cadherin/β-Catenin Complex: A Target for Anticancer and Antimetastasis Plants/Plant-derived Compounds

Plants reputed to have cancer-inhibiting potential and putative active components derived from those plants have emerged as an exciting new field in cancer study. Some of these compounds have cancer-inhibiting potential in different clinical staging levels, especially metastasis. A few of them which stabilize cell-cell adhesions are controversial topics. This review article introduces some effective herbal compounds that target E-cadherin/β-catenin protein complex. In this article, at first, we briefly review the structure and function of E-cadherin and β-catenin proteins, Wnt signaling pathway, and its target genes. Then, effective compounds of the Teucrium persicum, Teucrium polium, Allium sativum (garlic), Glycine max (soy), and Brassica oleracea (broccoli) plants, which influence stability and cellular localization of E-cadherin/β-catenin complex, were studied. Based on literature review, there are some compounds in these plants, including genistein of soy, sulforaphane of broccoli, organosulfur compounds of garlic, and the total extract of Teucrium genus that change the expression of variety of Wnt target genes such as MMPs, E-cadherin, p21, p53, c-myc, and cyclin D1. So they may induce cell-cycle arrest, apoptosis and/or inhibition of Epithelial-Mesenchymal Transition (EMT) and metastasis.

EMT: Present and future in clinical oncology

Epithelial/mesenchymal transition (EMT) has emerged as a key regulator of metastasis by facilitating tumor cell invasion and dissemination to distant organs. Recent evidences support that the reverse mesenchymal/epithelial transition (MET) is required for metastatic outgrowth; moreover, the existence of hybrid epithelial/mesenchymal (E/M) phenotypes is increasingly being reported in different tumor contexts. The accumulated data strongly support that plasticity between epithelial and mesenchymal states underlies the dissemination and metastatic potential of carcinoma cells. However, the translation into the clinics of EMT and epithelial plasticity processes presents enormous challenges and still remains a controversial issue. In this review, we will evaluate current evidences for translational applicability of EMT and depict an overview of the most recent EMT in vivo models, EMT marker analyses in human samples as well as potential EMT therapeutic approaches and ongoing clinical trials. We foresee that standardized analyses of EMT markers in solid and liquid tumor biopsies in addition to innovative tools targeting the E/M states will become promising strategies for future translation to the clinical setting.

Stromal Fibroblasts from the Interface Zone of Triple Negative Breast Carcinomas Induced Epithelial-Mesenchymal Transition and its Inhibition by Emodin

“Triple negative breast cancer” (TNBC) is associated with a higher rate and earlier time of recurrence and worse prognosis after recurrence. In this study, we aimed to examine the crosstalk between fibroblasts and TNBC cells. The fibroblasts were isolated from TNBC patients’ tissue in tumor burden zones, distal normal zones and interface zones. The fibroblasts were indicated as cancer-associated fibroblasts (CAFs), normal zone fibroblasts (NFs) and interface zone fibroblasts (INFs). Our study found that INFs grew significantly faster than NFs and CAFs in vitro. The epithelial BT20 cells cultured with the conditioned medium of INFs (INFs-CM) and CAFs (CAFs-CM) showed more spindle-like shape and cell scattering than cultured with the conditioned medium of NFs (NFs-CM). These results indicated that factors secreted by INFs-CM or CAFs-CM could induce the epithelial-mesenchymal transition (EMT) phenotype in BT20 cells. Using an in vitro co-culture model, INFs or CAFs induced EMT and promoted cancer cell migration in BT20 cells. Interestingly, we found that emodin inhibited INFs-CM or CAFs-CM-induced EMT programming and phenotype in BT20 cells. Previous studies reported that CAFs and INFs-secreted TGF-β promoted human breast cancer cell proliferation, here; our results indicated that TGF-β initiated EMT in BT20 cells. Pretreatment with emodin significantly suppressed the TGF-β-induced EMT and cell migration in BT20 cells. These results suggest that emodin may be used as a novel agent for the treatment of TNBC.

Emodin Inhibits the Epithelial to Mesenchymal Transition of Epithelial Ovarian Cancer Cells via ILK/GSK-3β/Slug Signaling Pathway

Epithelial ovarian cancer (EOC) is the most lethal gynecologic malignancy. Despite the anticancer capabilities of emodin observed in many cancers, including EOC, the underlying molecular mechanism remains to be elucidated. A crucial link has been discovered between the acquisition of metastatic traits and the epithelial-mesenchymal transition (EMT). The present study aimed to determine whether emodin could inhibit the EMT of EOC cells and explore the underlying mechanism. The CCK-8 assay and transwell assay showed that emodin effectively repressed the abilities of proliferation, invasion, and migration in A2780 and SK-OV-3 cells. The Western blot showed that emodin upregulated epithelial markers (E-cadherin and Claudin) while it downregulated mesenchymal markers (N-cadherin and Vimentin) and transcription factor (Slug) in a dose-dependent fashion. After transfection of siRNA-Slug, both Slug and N-cadherin were downregulated in EOC cells while E-cadherin was upregulated, which was intensified by emodin. Besides, emodin decreased the expression of ILK, p-GSK-3β, β-catenin, and Slug. Transfection of siRNA-ILK also achieved the same effects, which was further strengthened by following emodin treatment. Nevertheless, SB216763, an inhibitor of GSK-3β, could reverse the effects of emodin except for ILK expression. These findings suggest that emodin inhibited the EMT of EOC cells via ILK/GSK-3β/Slug signaling pathway.

Emodin ameliorates bleomycin-induced pulmonary fibrosis in rats by suppressing epithelial-mesenchymal transition and fibroblast activation

Aberrant activation of TGF-β1 is frequently encountered and promotes epithelial-mesenchymal transition (EMT) and fibroblast activation in pulmonary fibrosis. The present study investigated whether emodin mediates its effect via suppressing TGF-β1-induced EMT and fibroblast activation in bleomycin (BLM)-induced pulmonary fibrosis in rats. Here, we found that emodin induced apoptosis and inhibited cellular proliferation, migration and differentiation in TGF-β1-stimulated human embryonic lung fibroblasts (HELFs). Emodin suppressed TGF-β1-induced EMT in a dose- and time-dependent manner in alveolar epithelial A549 cells. Emodin also inhibited TGF-β1-induced Smad2, Smad3 and Erk1/2 activation, suggesting that Smad2/3 and Erk1/2 inactivation mediated the emodin-induced effects on TGF-β1-induced EMT. Additionally, we provided in vivo evidence suggesting that emodin apparently alleviated BLM-induced pulmonary fibrosis and improved pulmonary function by inhibiting TGF-β1 signaling and subsequently repressing EMT, fibroblast activation and extracellular matrix (ECM) deposition. Taken together, our data suggest that emodin mediates its effects mainly via inhibition of EMT and fibroblast activation and thus has a potential for the treatment of pulmonary fibrosis.

EMODIN EFFICACY ON THE AKT, MAPK, ERK AND DNMT EXPRESSION PATTERN DURING DMBA-INDUCED ORAL CARCINOMA IN GOLDEN SYRIAN HAMSTERS

Background:

The present study has evaluated the Emodin efficacy on the Akt, MAPK, ERK and DNMT expression pattern during 7,12-dimethylbenz[a]anthracene (DMBA)-induced oral carcinoma in golden Syrian hamsters, in order to explore its antitumor potential.

Materials and methods:

Oral tumors were developed in the buccal pouches of golden Syrian hamsters using the carcinogen, DMBA.

Results:

While the incidence of tumor formation was 100% in hamsters treated with DMBA alone, the tumor formation was not noticed in DMBA+ Emodin treated hamsters. Also, Emodin reduced the severity of precancerous pathological lesions such as dysplasia, in the hamsters treated with DMBA. Emodin administration corrected the abnormalities in the expression pattern of Akt, MAPK, ERK and DNMT in the buccal mucosa of hamsters treated with DMBA.

Conclusions:

The present study thus suggests that the tumor preventive potential of Emodin is partly related to its modulating effect on the Akt, MAPK, ERK and DNMT expression pattern, as these molecular markers have a pivotal role in the process of cell proliferation, inflammation, invasion, and apoptosis.

WITHDRAWN: Emodin increases expression of insulin-like growth factor binding protein 1 through activation of MEK/ERK/AMPKα and interaction of PPARγ and Sp1 in lung cancer

Due to an error in the publishing process, this article has been withdrawn at the request of the editors. We wish to clarify that this is in no way related to the integrity of the authors. The Publisher apologizes for any inconvenience this may cause. The full Elsevier Policy on Article Withdrawal can be found at http://www.elsevier.com/locate/withdrawalpolicy.