The Post-Translational Regulation of Epithelial-Mesenchymal Transition-Inducing Transcription Factors in Cancer Metastasis

Transferrin-Modified Carprofen Platinum(IV) Nanoparticles as Antimetastasis Agents with Tumor Targeting, Inflammation Inhibition, Epithelial-Mesenchymal Transition Suppression, and Immune Activation Properties

The inflammatory microenvironment is a central driver of tumor metastasis, intimately associated with the promotion of epithelial-mesenchymal transition (EMT) and immune suppression. Here, transferrin-modified carprofen platinum(IV) nanoparticles Tf-NPs@CPF2-Pt(IV) with promising antiproliferative and antimetastatic properties were developed, which activated by inhibiting inflammation, suppressing EMT, and activating immune responses besides causing DNA injury. The nanoparticles released the active ingredient CPF2-Pt(IV) in a sustained manner and offered enhanced pharmacokinetic properties compared to free CPF2-Pt(IV) in vivo. Additionally, they possessed satisfactory tumor targeting effects via the transferrin motif. Serious DNA damage was induced with the upregulation of γ-H2AX and P53, and the mitochondria-mediated apoptotic pathway Bcl-2/Bax/caspase3 was initiated. Inflammation was alleviated by inhibiting COX-2 and MMP9 and decreasing inflammatory cytokines TNF-α and IL-6. Subsequently, the EMT was reversed by inhibiting the Wnt/β-catenin pathway. Furthermore, the antitumor immunity was provoked by blocking the immune checkpoint PD-L1 and increasing CD3+ and CD8+ T lymphocytes in tumors.

Relationship of Signaling Pathways between RKIP Expression and the Inhibition of EMT-Inducing Transcription Factors SNAIL1/2, TWIST1/2 and ZEB1/2

Untreated primary carcinomas often lead to progression, invasion and metastasis, a process that involves the epithelial-to-mesenchymal transition (EMT). Several transcription factors (TFs) mediate the development of EMT, including SNAIL1/SNAIL2, TWIST1/TWIST2 and ZEB1/ZEB2, which are overexpressed in various carcinomas along with the under expression of the metastasis suppressor Raf Kinase Inhibitor Protein (RKIP). Overexpression of RKIP inhibits EMT and the above associated TFs. We, therefore, hypothesized that there are inhibitory cross-talk signaling pathways between RKIP and these TFs. Accordingly, we analyzed the various properties and biomarkers associated with the epithelial and mesenchymal tissues and the various molecular signaling pathways that trigger the EMT phenotype such as the TGF-β, the RTK and the Wnt pathways. We also presented the various functions and the transcriptional, post-transcriptional and epigenetic regulations for the expression of each of the EMT TFs. Likewise, we describe the transcriptional, post-transcriptional and epigenetic regulations of RKIP expression. Various signaling pathways mediated by RKIP, including the Raf/MEK/ERK pathway, inhibit the TFs associated with EMT and the stabilization of epithelial E-Cadherin expression. The inverse relationship between RKIP and the TF expressions and the cross-talks were further analyzed by bioinformatic analysis. High mRNA levels of RKIP correlated negatively with those of SNAIL1, SNAIL2, TWIST1, TWIST2, ZEB1, and ZEB2 in several but not all carcinomas. However, in these carcinomas, high levels of RKIP were associated with good prognosis, whereas high levels of the above transcription factors were associated with poor prognosis. Based on the inverse relationship between RKIP and EMT TFs, it is postulated that the expression level of RKIP in various carcinomas is clinically relevant as both a prognostic and diagnostic biomarker. In addition, targeting RKIP induction by agonists, gene therapy and immunotherapy will result not only in the inhibition of EMT and metastases in carcinomas, but also in the inhibition of tumor growth and reversal of resistance to various therapeutic strategies. However, such targeting strategies must be better investigated as a result of tumor heterogeneities and inherent resistance and should be better adapted as personalized medicine.

Evaluation of the Antifibrotic Effects of Drugs Commonly Used in Inflammatory Intestinal Diseases on In Vitro Intestinal Cellular Models

The mechanism underlying intestinal fibrosis, the main complication of inflammatory bowel disease (IBD), is not yet fully understood, and there is no therapy to prevent or reverse fibrosis. We evaluated, in in vitro cellular models, the ability of different classes of drugs currently used in IBD to counteract two pivotal processes of intestinal fibrosis, the differentiation of intestinal fibroblasts to activated myofibroblasts using CCD-18Co cells, and the epithelial-to-mesenchymal transition (EMT) of intestinal epithelial cells using Caco-2 cells (IEC), both being processes induced by transforming growth factor-β1 (TGF-β1). The drugs tested included mesalamine, azathioprine, methotrexate, prednisone, methylprednisolone, budesonide, infliximab, and adalimumab. The expression of fibrosis and EMT markers (collagen-I, α-SMA, pSmad2/3, occludin) was assessed by Western blot analysis and by immunofluorescence. Of the drugs used, only prednisone, methylprednisolone, budesonide, and adalimumab were able to antagonize the pro-fibrotic effects induced by TGF-β1 on CCD-18Co cells, reducing the fibrosis marker expression. Methylprednisolone, budesonide, and adalimumab were also able to significantly counteract the TGF-β1-induced EMT process on Caco-2 IEC by increasing occludin and decreasing α-SMA expression. This is the first study that evaluates, using in vitro cellular models, the direct antifibrotic effects of drugs currently used in IBD, highlighting which drugs have potential antifibrotic effects.

Canadine Platinum(IV) Complexes Targeting Epithelial-Mesenchymal Transition as Antiproliferative and Antimetastatic Agents

Epithelial-mesenchymal transition (EMT) is a critical process for cancer progression, which is crucial in inhibiting the immunity in tumors and further boosting tumor metastasis. The suppression of EMT represents a promising strategy for inhibiting metastatic tumors. Herein, a series of new canadine platinum(IV) conjugates with potent antiproliferative and antimetastatic activities were developed, which activated by suppressing EMT and provoking immune response in tumors besides causing DNA injury. The complexes could covalently conjugate to DNA and induce mitochondria-mediated apoptosis via Bcl-2/Bax/caspase3 signaling. The EMT process was remarkably inhibited by suppressing the Wnt/β-catenin pathway, reversing the inflammatory tumor microenvironment, and inhibiting the HIF-1α pathway, which further resulted in the inhibited angiogenesis in tumors. Moreover, the antitumor immunity was elevated by blocking immune checkpoints PD-L1 and CD47 accompanied by the improvement of CD3+ and CD8+ T lymphocytes and the macrophage polarization from M2- toward M1-type simultaneously in tumors.

Spheroid Model of Mammary Tumor Cells: Epithelial-Mesenchymal Transition and Doxorubicin Response

Breast cancer is the most prevalent cancer among women worldwide. Therapeutic strategies to control tumors and metastasis are still challenging. Three-dimensional (3D) spheroid-type systems more accurately replicate the features of tumors in vivo, working as a better platform for performing therapeutic response analysis. This work aimed to characterize the epithelial-mesenchymal transition and doxorubicin (dox) response in a mammary tumor spheroid (MTS) model. We evaluated the doxorubicin treatment effect on MCF-7 spheroid diameter, cell viability, death, migration and proteins involved in the epithelial-mesenchymal transition (EMT) process. Spheroids were also produced from tumors formed from 4T1 and 67NR cell lines. MTSs mimicked avascular tumor characteristics, exhibited adherens junction proteins and independently produced their own extracellular matrix. Our spheroid model supports the 3D culturing of cells isolated from mice mammary tumors. Through the migration assay, we verified a reduction in E-cadherin expression and an increase in vimentin expression as the cells became more distant from spheroids. Dox promoted cytotoxicity in MTSs and inhibited cell migration and the EMT process. These results suggest, for the first time, that this model reproduces aspects of the EMT process and describes the potential of dox in inhibiting the metastatic process, which can be further explored.

Regulating epithelial-mesenchymal plasticity from 3D genome organization

Epithelial-mesenchymal transition (EMT) is a dynamic process enabling polarized epithelial cells to acquire mesenchymal features implicated in development and carcinoma progression. As our understanding evolves, it is clear the reversible execution of EMT arises from complex epigenomic regulation involving histone modifications and 3-dimensional (3D) genome structural changes, leading to a cascade of transcriptional events. This review summarizes current knowledge on chromatin organization in EMT, with a focus on hierarchical structures of the 3D genome and chromatin accessibility changes.

Ursolic acid inhibits glioblastoma through suppressing TGFβ-mediated epithelial-mesenchymal transition (EMT) and angiogenesis

Found in many fruits and plants, Ursolic acid (UA), a pentacyclic triterpene that occurs naturally, is recognized for its anti-cancer effects, especially in combating glioblastoma. However, the intricate molecular mechanisms underpinning its anti-tumor actions are still not fully understood, despite the recognition of these effects. By examining the functions of epithelial-mesenchymal transition (EMT) and angiogenesis, crucial for glioblastoma progression, and their regulation through Transforming Growth Factor Beta (TGFβ) - a key marker for glioblastoma, our research aims to fill this knowledge gap. This study explores how ursolic acid can block the progression of glioblastoma by precisely targeting TGFβ-triggered EMT and angiogenesis. The findings show that UA successfully blocks the spread, movement, and invasion of glioblastoma cells. Accompanying this, there is a significant reduction in the expression of TGFβ and crucial EMT indicators like snail and vimentin. Furthermore, UA shows a reduction in angiogenesis that depends on the dosage, highlighted by decreased vascular endothelial growth factor (VEGF) in human umbilical vein endothelial cells (HUVECs). Interestingly, increased TGFβ expression in U87 and U251 glioblastoma cell lines was found to weaken UA's anti-tumor properties, shedding more light on TGFβ's critical function in glioblastoma's pathology. Supporting these laboratory results, UA also showed considerable inhibition of tumor growth in a glioblastoma xenograft mouse model. Overall, our research emphasizes Ursolic acid's promise as a new treatment for glioblastoma and clarifies its action mechanism, mainly by inhibiting TGFβ signaling and thereby EMT and angiogenesis.

Characterization of gastric cancer-stimulated signaling pathways and function of CTGF in cancer-associated fibroblasts

BACKGROUND

Cancer-associated fibroblasts (CAFs) are key components of the tumor microenvironment (TME) that play an important role in cancer progression. Although the mechanism by which CAFs promote tumorigenesis has been well investigated, the underlying mechanism of CAFs activation by neighboring cancer cells remains elusive. In this study, we aim to investigate the signaling pathways involved in CAFs activation by gastric cancer cells (GC) and to provide insights into the therapeutic targeting of CAFs for overcoming GC.

METHODS

Alteration of receptor tyrosine kinase (RTK) activity in CAFs was analyzed using phospho-RTK array. The expression of CAFs effector genes was determined by RT-qPCR or ELISA. The migration and invasion of GC cells co-cultured with CAFs were examined by transwell migration/invasion assay.

RESULTS

We found that conditioned media (CM) from GC cells could activate multiple receptor tyrosine kinase signaling pathways, including ERK, AKT, and STAT3. Phospho-RTK array analysis showed that CM from GC cells activated PDGFR tyrosine phosphorylation, but only AKT activation was PDGFR-dependent. Furthermore, we found that connective tissue growth factor (CTGF), a member of the CCN family, was the most pronouncedly induced CAFs effector gene by GC cells. Knockdown of CTGF impaired the ability of CAFs to promote GC cell migration and invasion. Although the PDGFR-AKT pathway was pronouncedly activated in CAFs stimulated by GC cells, its pharmacological inhibition affected neither CTGF induction nor CAFs-induced GC cell migration. Unexpectedly, the knockdown of SRC and SRC-family kinase inhibitors, dasatinib and saracatinib, significantly impaired CTGF induction in activated CAFs and the migration of GC cells co-cultured with CAFs. SRC inhibitors restored the reduced expression of epithelial markers, E-cadherin and Zonula Occludens-1 (ZO-1), in GC cells co-cultured with CAFs, as well as CAFs-induced aggregate formation in a 3D tumor spheroid model.

CONCLUSIONS

This study provides a characterization of the signaling pathways and effector genes involved in CAFs activation, and strategies that could effectively inhibit it in the context of GC. Video Abstract.

Expression of Tumor Suppressor FHIT Is Regulated by the LINC00173-SNAIL Axis in Human Lung Adenocarcinoma

Long non-coding RNAs (lncRNAs) play a critical role in a variety of human diseases such as cancer. Here, to elucidate a novel function of a lncRNA called LINC00173, we investigated its binding partner, target gene, and its regulatory mechanism in lung adenocarcinoma, including the A549 cell line and patients. In the A549 cell line, RNA immunoprecipitation (RIP) assays revealed that LINC00173 efficiently binds to SNAIL. RNA-seq and RT-qPCR analyses revealed that the expression of FHIT was decreased upon LINC00173 depletion, indicating that FHIT is a target gene of LINC00173. Overexpression of SNAIL suppressed and depletion of SNAIL increased the expression of FHIT, indicating that SNAIL negatively regulates FHIT. The downregulation of FHIT expression upon LINC00173 depletion was restored by additional SNAIL depletion, revealing a LINC00173-SNAIL-FHIT axis for FHIT regulation. Data from 501 patients with lung adenocarcinoma also support the existence of a LINC00173-SNAIL-FHIT axis, as FHIT expression correlated positively with LINC00173 (p = 1.75 × 10-6) and negatively with SNAIL (p = 7.00 × 10-5). Taken together, we propose that LINC00173 positively regulates FHIT gene expression by binding to SNAIL and inhibiting its function in human lung adenocarcinoma. Thus, this study sheds light on the LINC00173-SNAIL-FHIT axis, which may be a key mechanism for carcinogenesis and progression in human lung adenocarcinoma.

Oxidative stress regulation and related metabolic pathways in epithelial-mesenchymal transition of breast cancer stem cells

Epithelial-mesenchymal transition (EMT) is a cell remodeling process in which epithelial cells undergo a reversible phenotype switch via the loss of adhesion capacity and acquisition of mesenchymal characteristics. In other words, EMT activation can increase invasiveness and metastatic properties, and prevent the sensitivity of tumor cells to chemotherapeutics, as mesenchymal cells have a higher resistance to chemotherapy and immunotherapy. EMT is orchestrated by a complex and multifactorial network, often linked to episodic, transient, or partial events. A variety of factors have been implicated in EMT development. Based on this concept, multiple metabolic pathways and master transcription factors, such as Snail, Twist, and ZEB, can drive the EMT. Emerging evidence suggests that oxidative stress plays a significant role in EMT induction. One emerging theory is that reducing mitochondrial-derived reactive oxygen species production may contribute to EMT development. This review describes how metabolic pathways and transcription factors are linked to EMT induction and addresses the involvement of signaling pathways.

ZEB1 potentiates chemoresistance in breast cancer stem cells by evading apoptosis

Chemoresistance renders a challenge to the clinics to treat breast cancer patients. Current treatment strategies are effective in mitigating tumor growth but remain largely ineffective against cancer-initiating cells or breast Cancer Stem Cells (CSCs). Epithelial-to-mesenchymal-transition (EMT) regulates breast CSC physiology. Zinc finger E-box binding homeobox 1 (ZEB1) is a key EMT-transcription factor that regulates breast CSC - differentiation and metastasis. However, its potential role in modulating tumor chemoresistance has not yet been fully understood. In-silico analysis revealed a higher ZEB1 expression in breast cancer patients that leads to decreased overall and relapse-free survival. We generated sorted breast CSC with stable ZEB1 overexpression (CD24-/CD44+GFP-ZEB1) and/or silencing (CD24-/CD44+ZEB1 shRNA) as well as breast cancer cells with stable ZEB1 overexpression (CD24+GFP-ZEB1) and/or silencing (CD24+ZEB1 shRNA). An increased colony-forming efficiency and doxorubicin accumulation correlated with decreased promoter activity and expression profile of ABCC1 drug-efflux ABC transporter in CD24-/CD44+GFP-ZEB1. Additionally, CD24-/CD44+GFP-ZEB1 demonstrated doxorubicin-induced higher anti-apoptotic and lower pro-apoptotic protein expressions in the mitochondrial and cytosolic fractions. Chemoresistant CD24-/CD44+GFP-ZEB1 cells depicted 1000-fold higher IC-50 values of doxorubicin and decreased activation of JNK-p38 stress kinase molecular signaling-dependent mammosphere forming efficiency to evade apoptosis. Thus, ZEB1 and its downstream effectors are plausible therapeutic targets for the mitigation of breast cancer chemoresistance in patients.

The epithelial-mesenchymal plasticity landscape: principles of design and mechanisms of regulation

Epithelial-mesenchymal plasticity (EMP) enables cells to interconvert between several states across the epithelial-mesenchymal landscape, thereby acquiring hybrid epithelial/mesenchymal phenotypic features. This plasticity is crucial for embryonic development and wound healing, but also underlies the acquisition of several malignant traits during cancer progression. Recent research using systems biology and single-cell profiling methods has provided novel insights into the main forces that shape EMP, which include the microenvironment, lineage specification and cell identity, and the genome. Additionally, key roles have emerged for hysteresis (cell memory) and cellular noise, which can drive stochastic transitions between cell states. Here, we review these forces and the distinct but interwoven layers of regulatory control that stabilize EMP states or facilitate epithelial-mesenchymal transitions (EMTs) and discuss the therapeutic potential of manipulating the EMP landscape.

Role of pelitinib in the regulation of migration and invasion of hepatocellular carcinoma cells via inhibition of Twist1

BACKGROUND

Overexpression of Twist1, one of the epithelial-mesenchymal transition-transcription factors (EMT-TFs), is associated with hepatocellular carcinoma (HCC) metastasis. Pelitinib is known to be an irreversible epidermal growth factor receptor tyrosine kinase inhibitor that is used in clinical trials for colorectal and lung cancers, but the role of pelitinib in cancer metastasis has not been studied. This study aimed to investigate the anti-migration and anti-invasion activities of pelitinib in HCC cell lines.

METHODS

Using three HCC cell lines (Huh7, Hep3B, and SNU449 cells), the effects of pelitinib on cell cytotoxicity, invasion, and migration were determined by cell viability, wound healing, transwell invasion, and spheroid invasion assays. The activities of MMP-2 and -9 were examined through gelatin zymography. Through immunoblotting analyses, the expression levels of EMT-TFs (Snail1, Twist1, and ZEB1) and EMT-related signaling pathways such as mitogen-activated protein kinases (MAPKs) and Akt signaling pathways were measured. The activity and expression levels of target genes were analyzed by reporter assay, RT-PCR, quantitative RT-PCR, and immunoblotting analysis. Statistical analysis was performed using one-way ANOVA with Dunnett's Multiple comparison tests in Prism 3.0 to assess differences between experimental conditions.

RESULTS

In this study, pelitinib treatment significantly inhibited wound closure in various HCC cell lines, including Huh7, Hep3B, and SNU449. Additionally, pelitinib was found to inhibit multicellular cancer spheroid invasion and metalloprotease activities in Huh7 cells. Further investigation revealed that pelitinib treatment inhibited the migration and invasion of Huh7 cells by inducing Twist1 degradation through the inhibition of MAPK and Akt signaling pathways. We also confirmed that the inhibition of cell motility by Twist1 siRNA was similar to that observed in pelitinib-treated group. Furthermore, pelitinib treatment regulated the expression of target genes associated with EMT, as demonstrated by the upregulation of E-cadherin and downregulation of N-cadherin.

CONCLUSION

Based on our novel finding of pelitinib from the perspective of EMT, pelitinib has the ability to inhibit EMT activity of HCC cells via inhibition of Twist1, and this may be the potential mechanism of pelitinib on the suppression of migration and invasion of HCC cells. Therefore, pelitinib could be developed as a potential anti-cancer drug for HCC.

Anti-migration and anti-invasion effects of LY-290181 on breast cancer cell lines through the inhibition of Twist1

Breast cancer has become the most common cancer among women worldwide. Among breast cancers, metastatic breast cancer is associated with the highest mortality rate. Twist1, one of the epithelial-mesenchymal transition-regulating transcription factors, is known to promote the intravasation of breast cancer cells into metastatic sites. Therefore, targeting Twist1 to develop anti-cancer drugs might be a valuable strategy. In this study, LY-290181 dose-dependently inhibited migration, invasion, and multicellular tumor spheroid invasion in breast cancer cell lines. These anti-cancer effects of LY-290181 were mediated through the down-regulation of Twist1 protein levels. LY-290181 inhibited extracellular signal-regulated kinase and c-Jun N-terminal kinase signaling pathways. Therefore, our findings suggest that LY-290181 may serve as a basis for future research and development of an anti-cancer agent targeting metastatic cancers. [BMB Reports 2023; 56(7): 410-415].

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.

Single-cell RNA sequencing reveals microenvironment context-specific routes for epithelial-mesenchymal transition in pancreas cancer cells

In the PDAC tumor microenvironment, multiple factors initiate the epithelial-mesenchymal transition (EMT) that occurs heterogeneously among transformed ductal cells, but it is unclear if different drivers promote EMT through common or distinct signaling pathways. Here, we use single-cell RNA sequencing (scRNA-seq) to identify the transcriptional basis for EMT in pancreas cancer cells in response to hypoxia or EMT-inducing growth factors. Using clustering and gene set enrichment analysis, we find EMT gene expression patterns that are unique to the hypoxia or growth factor conditions or that are common between them. Among the inferences from the analysis, we find that the FAT1 cell adhesion protein is enriched in epithelial cells and suppresses EMT. Further, the receptor tyrosine kinase AXL is preferentially expressed in hypoxic mesenchymal cells in a manner correlating with YAP nuclear localization, which is suppressed by FAT1 expression. AXL inhibition prevents EMT in response to hypoxia but not growth factors. Relationships between FAT1 or AXL expression with EMT were confirmed through analysis of patient tumor scRNA-seq data. Further exploration of inferences from this unique dataset will reveal additional microenvironment context-specific signaling pathways for EMT that may represent novel drug targets for PDAC combination therapies.

NONHSAT021545/miR-330-3p/EREG: A Cooperative Axis in Breast Cancer Prognosis and Treatment

Lymphatic metastasis is the most common form in breast cancer (BC) progression. Previously, we observed that lnc045874, a most conservative homology of Homo Sapiens NONHSAT021545 (lnc021545), miR-330-3p, and EREG may have some effects in mouse hepatocarcinoma cell lines with different lymphatic metastasis potentials. Through data from TCGA and GEO database analysis, we speculated that miR-330-3p might be a tumor promoter, while EREG could be a tumor suppressor in BC. MiR-330-3p was upregulated, while lnc021545 and EREG were downregulated in 50 BC tissues. MiR-330-3p advanced the metastatic behaviors of BC cells, whereas lnc021545 and EREG resulted in the opposite effects. The three molecules' expressions were correlated respectively and showed that miR-330-3p targeted lnc021545 and EREG to affect their expressions. Lnc021545/miR-330-3p axis affected BC metastasis by regulating EREG in epithelial-to-mesenchymal transition. In 50 BC patients, these three molecules and their cooperation are associated with aggressive tumor phenotypes, patient outcomes, and trastuzumab therapy. We finally discovered that lnc021545, miR-330-3p, and EREG formed a multi-gene co-regulation system that affected the metastasis of BC and the cooperation reflects the synergistic effects of the three molecules, recommending that their cooperation may provide a more accurate index for anti-metastasis therapeutic and prognostic evaluation of BC.

The ceRNA network regulates epithelial-mesenchymal transition in colorectal cancer

Epithelial-mesenchymal transition (EMT) is a biological process that transforms epithelial cells into a mesenchymal phenotype, conferring cell migration and invasion capabilities. EMT is involved in the progression and metastasis of colorectal cancer (CRC). Recently, emerging evidence has shown dysregulation of non-coding RNA (ncRNA) was linked to EMT. ncRNAs, including long non-coding RNA (lncRNA), regulate the transcription of downstream target genes (mRNA) through interaction with microRNAs (miRNAs); these are termed competitive endogenous RNA (ceRNA) networks. CeRNA dysregulation-induced EMT, which is linked to the progression and prognosis of CRC, has attracted wide attention. However, understanding the role of the regulation of the ceRNA network in the EMT of CRC remains limited. We discuss the molecular functions of lncRNA, the ceRNA networks related to miRNAs and mRNAs in EMT, as well as EMT transcription factors, such as the zinc finger E-box binding homeobox 1/2 (ZEB1/2), SNAIL, SLUG, and TWIST1/2. In addition, miRNAs and lncRNAs that directly target genes, thereby initiating different signaling pathways to promote EMT in CRC, were summarized. Clarifying the role of these molecules in EMT is critical for understanding molecular mechanisms and exploring the potential therapeutic targets of CRC.

Elucidating the role of PRMTs in prostate cancer using open access databases and a patient cohort dataset

Protein arginine methylation is an understudied epigenetic mechanism catalyzed by enzymes known as Protein Methyltransferases of Arginine (PRMTs), while the opposite reaction is performed by Jumonji domain- containing protein 6 (JMJD6). There is increasing evidence that PRMTs are deregulated in prostate cancer (PCa). In this study, the expression of two PRMT members, PRMT2 and PRMT7 as well as JMJD6, a demethylase, was analyzed in PCa. Initially, we retrieved data from The Cancer Genome Atlas (TCGA) project and the Gene Expression Omnibus (GEO) database to explore the differential expression of various PRMT family members in patients with PCa and then applied immunohistochemistry in a patient cohort across the spectrum of PCa, including non-neoplastic prostate tissue and lymph node metastatic foci. The results from the TCGA analysis revealed that PRMT7, PRMT6 and PRMT3 expression increased while PRMT2, PRMT9 and JMJD6 levels decreased in the tumor compared to non-neoplastic prostate. Results from the GEO datasets were similar, albeit not identical with the TCGA results, with PRMT7 and PRMT3 being upregulated and PRMT2 and JMJD6 being downregulated in the tumor compared to non-neoplastic tissue in some of them. In addition, PRMT7 levels decreased with stage and grade progression in the TCGA analysis. In the patient cohort, both PRMTs and JMJD6 were overexpressed in PCa compared to non-neoplastic tissue, and nuclear PRMT2 and JMJD6 were upregulated in lymph node metastasis, too. PRMT7 and JMJD6 expression were upregulated with the progression of stage and JMJD6 was also increased with the elevation of grade. After androgen ablation therapy, nuclear expression of PRMT7 and JMJD6 were elevated compared to untreated tumors. PRMT2, PRMT7 and JMD6 were also correlated with markers of EMT and cell cycle regulators. Finally, our findings indicate that PRMTs and JMJD6 are involved in prostate cancer progression and revealed a potential interplay of PRMTs with EMT mediators, underscoring the need for therapeutic targeting of arginine methylation in prostate cancer.

ROR2 promotes epithelial-mesenchymal transition by hyperactivating ERK in melanoma

Receptor tyrosine kinase-like orphan receptor 2 (ROR2) is a protein with important functions during embryogenesis that is dysregulated in human cancer. An intriguing feature of this receptor is that it plays opposite roles in different tumor types either promoting or inhibiting tumor progression. Understanding the complex role of this receptor requires a more profound exploration of both the altered biological and molecular mechanisms. Here, we describe that ROR2 promotes Epithelial-Mesenchymal Transition (EMT) by inducing cadherin switch and the upregulation of the transcription factors ZEB1, Twist, Slug, Snail, and HIF1A, together with a mesenchymal phenotype and increased migration. We show that ROR2 activates both p38 and ERK mitogen-activated protein kinase pathways independently of Wnt5a. Further, we demonstrated that the upregulation of EMT-related proteins depends on the hyperactivation of the ERK pathway far above the typical high constitutive activity observed in melanoma. In addition, ROR2 also promoted ERK phosphorylation, EMT, invasion, and necrosis in xenotransplanted mice. ROR2 also associates with EMT in tumor samples from melanoma patients where analysis of large cohorts revealed that increased ROR2 levels are linked to EMT signatures. This important role of ROR2 translates into melanoma patient' s prognosis since elevated ROR2 levels reduced overall survival and distant metastasis-free survival of patients with lymph node metastasis. In sum, these results demonstrate that ROR2 contributes to melanoma progression by inducing EMT and necrosis and can be an attractive therapeutic target for melanoma.

Downregulation of iNOS/NO Promotes Epithelial-Mesenchymal Transition and Metastasis in Colorectal Cancer

Metastasis is the major cause of cancer-related death in patients with colorectal cancer. Although inducible nitric oxide synthase (iNOS) is a crucial regulator of cancer development and progression, its roles in epithelial-mesenchymal transition (EMT) and the pathogenesis of metastatic colorectal cancer have not been fully investigated. Primary colorectal cancer and liver metastatic tissue specimens were analyzed showing 90% of liver metastatic colorectal cancer with reduced expressions of iNOS compared with 6% of primary colorectal cancer. The Cancer Genome Atlas database analyses via cBioPortal reveal that mRNA expression of iNOS negatively correlated with selected EMT markers in colorectal cancer in a cancer type-dependent manner. The transcriptomic profiling (RNA sequencing data) indicates that iNOS knockdown in SW480 colorectal cancer cells induced an EMT program with upregulated expression of selected stem-cell markers. iNOS knockdown did not alter E-cadherin mRNA expression but re-localized it from membrane to cytoplasm through iNOS-GATA4-Crb2-E-cadherin pathway. iNOS knockdown induced a change in cell morphology, and promoted cell invasion and migration in vitro, and metastasis in vivo.

IMPLICATIONS

iNOS downregulation-induced pathway networks mediate the EMT program and metastasis. As an EMT inducer, the reduced-iNOS may serve as a potential therapeutic target for patients with colorectal cancer.

Post-warming culture of human vitrified blastocysts with prolactin improves trophoblast outgrowth

BACKGROUND

Human embryos express the prolactin (PRL) receptor at the morula and blastocyst stages. Treatment with PRL from cleavage to the blastocyst stage improves blastocyst outgrowth on fibronectin-coated dishes. However, whether post-warming PRL treatment of blastocysts cultured without PRL could improve outgrowth competence remains unknown. Furthermore, the optimal time for post-warming PRL treatment remains to be ascertained. This study investigated the effects of PRL treatment during recovery culture on human blastocyst outgrowth and its related genes.

METHODS

In total, 374 discarded vitrified blastocysts were randomly allocated to two groups, to be cultured with (n = 208) or without PRL (control; n = 166) for 120 min for recovery, and then plated on fibronectin-coated dishes. The expression level of PRL-interacting genes, blastocyst adhesion rate, outgrowth area, distance of trophoblast migration, and outgrowth degeneration were examined.

RESULTS

The mRNA expression of ezrin, radixin, and moesin, which regulate cell adhesion and invasion by controlling actin reorganization during epithelial-to-mesenchymal transition (EMT), was stimulated by PRL treatment for 120 min. The expression of EMT-related genes, transforming growth factor β1, snail1, and twist1 was also promoted following treatment with PRL for 120 min. PRL-treated blastocysts also exhibited augmented expression of cadherin 2 and transcriptional repression of cadherin 1. Higher mRNA expression of integrin-based focal adhesion-related genes, ITGA5 and ITGB1, was observed after treatment with PRL for 120 min than in the non- and shorter-treatment groups. PRL treatment for 120 min did not alter the rate of blastocyst adhesion to fibronectin-coated dishes 96 h after the outgrowth culture assay. However, multiple linear regression analysis revealed that the outgrowth area was significantly increased in PRL-treated blastocysts. The migration distance of trophoblast cells was significantly increased and degeneration rate was significantly decreased after PRL treatment. Furthermore, a more beneficial effect of PRL treatment on blastocyst outgrowth was observed when the blastocysts were vitrified on day 5 than when they were vitrified on day 6.

CONCLUSIONS

Post-warming culture of human vitrified blastocysts with PRL for 120 min promoted trophoblast outgrowth in vitrified human blastocysts. Furthermore, PRL treatment may reduce outgrowth degeneration by increasing resistance to apoptosis during trophoblast migration.

Cancer Cell De-Differentiation: Plasticity-Driven Stratagem For Tumor Metastasis and Recurrence

Tumor recurrence is a colossal challenge in clinical oncology. This multifactorial problem is attributed to the emergence of additional genetic mutations and the presence of dormant cancer cells. However, the plasticity of non-stem cancer cells and the acquisition of cancer stem cell (CSC) functionality is another contributing factor to tumor recurrence. Herein, I focus attention on the mechanisms that fuel cancer cell de-differentiation and the interplay between intra-cellular regulators and tumor microenvironment (TME) landscape that promotes cancer cell stemness. Our understanding of the mechanisms underlying tumor cell de-differentiation is crucial for developing innovative therapeutic strategies that prevent cancer from ever recurring.

Targeting tumor-intrinsic PD-L1 suppresses the progression and aggressiveness of head and neck cancer by inhibiting GSK3β-dependent Snail degradation

PURPOSE

PD-L1 is an immune checkpoint protein that allows cells to evade T-cell-mediated immune responses. Herein, we uncover a tumor-intrinsic mechanism of PD-L1 that is responsible for the progression and aggressiveness of HNC and reveal that the extracts of a brown alga can target the tumor-intrinsic signaling pathway of PD-L1.

METHODS

The biological functions of PD-L1 in the proliferation and aggressiveness of HNC cells in vitro were examined by metabolic activity, clonogenic, tumorigenicity, wound healing, migration, and invasion assays. The clinical importance of PD-L1 in the prognosis of patients with HNC was analyzed by immunohistochemistry. The relationship between PD-L1 and EMT was confirmed via western blotting, qPCR, and immunocytochemistry.

RESULTS

Through our in silico approach, we found that PD-L1 was upregulated in HNC and was correlated with an unfavorable clinical outcome in patients with HNC. PD-L1 was crucial for promoting tumor growth, both in vitro and in vivo. High expression of PD-L1 was closely correlated with LN metastasis in OSCC. PD-L1 facilitated the cytoskeletal reorganization and aggressiveness of HNC cells. Moreover, PD-L1 enhanced the EMT of HNC cells by regulating the Snail/vimentin axis. Consistently, MEIO suppressed the PD-L1/Snail/vimentin axis, thereby inhibiting the aggressiveness of HNC cells. Inhibition of PD-L1 induced by PD-L1 silencing or MEIO treatment caused Snail degradation through a GSK3β-dependent mechanism. The tumor-intrinsic function of PD-L1 could be attributed to the regulation of the GSK3β/Snail/vimentin axis.

CONCLUSION

The discovery of MEIO targeting the tumor-intrinsic function of PD-L1 may prove particularly valuable for the development of novel and effective anticancer drug candidates for HNCs overexpressing PD-L1.

Epithelial–Mesenchymal Transition by Synergy between Transforming Growth Factor-β and Growth Factors in Cancer Progression

Epithelial–mesenchymal transition (EMT) plays a crucial role in appropriate embryonic development, as well as wound healing, organ fibrosis, and cancer progression. During cancer progression, EMT is associated with the invasion, metastasis, and generation of circulating tumor cells and cancer stem cells, as well as resistance to chemo- and radiation therapy. EMT is induced by several transcription factors, known as EMT transcription factors (EMT-TFs). In nearly all cases, EMT-TFs appear to be regulated by growth factors or cytokines and extracellular matrix components. Among these factors, transforming growth factor (TGF)-β acts as the key mediator for EMT during physiological and pathological processes. TGF-β can initiate and maintain EMT by activating intracellular/intercellular signaling pathways and transcriptional factors. Recent studies have provided new insights into the molecular mechanisms underlying sustained EMT in aggressive cancer cells, EMT induced by TGF-β, and crosstalk between TGF-β and growth factors.

The Protein L-Isoaspartyl (D-Aspartyl) Methyltransferase Regulates Glial-to-Mesenchymal Transition and Migration Induced by TGF-β1 in Human U-87 MG Glioma Cells

The enzyme PIMT methylates abnormal aspartyl residues in proteins. U-87 MG cells are commonly used to study the most frequent brain tumor, glioblastoma. Previously, we reported that PIMT isoform I possessed oncogenic features when overexpressed in U-87 MG and U-251 MG glioma cells. Higher levels of wild-type PIMT stimulated migration and invasion in both glioma cell lines. Conversely, PIMT silencing reduced these migratory abilities of both cell lines. These results indicate that PIMT could play a critical role in glioblastoma growth. Here, we investigated for the first time, molecular mechanisms involving PIMT in the regulation of epithelial to mesenchymal transition (EMT) upon TGF-β1 treatments. Gene array analyses indicated that EMT genes but not PIMT gene were regulated in U-87 MG cells treated with TGF-β1. Importantly, PIMT silencing by siRNA inhibited in vitro migration in U-87 MG cells induced by TGF-β1. In contrast, overexpressed wild-type PIMT and TGF-β1 had additive effects on cell migration. When PIMT was inhibited by siRNA, this prevented Slug induction by TGF-β1, while Snail stimulation by TGF-β1 was increased. Indeed, overexpression of wild-type PIMT led to the opposite effects on Slug and Snail expression dependent on TGF-β1. These data highlighted the importance of PIMT in the EMT response dependent on TGF-β1 in U-87 MG glioma cells by an antagonist regulation in the expression of transcription factors Slug and Snail, which are critical players in EMT.

Regulation of epithelial-mesenchymal transition by protein lysine acetylation

The epithelial-mesenchymal transition (EMT) is a vital driver of tumor progression. It is a well-known and complex trans-differentiation process in which epithelial cells undergo morphogenetic changes with loss of apical-basal polarity, but acquire spindle-shaped mesenchymal phenotypes. Lysine acetylation is a type of protein modification that favors reversibly altering the structure and function of target molecules via the modulation of lysine acetyltransferases (KATs), as well as lysine deacetylases (KDACs). To date, research has found that histones and non-histone proteins can be acetylated to facilitate EMT. Interestingly, histone acetylation is a type of epigenetic regulation that is capable of modulating the acetylation levels of distinct histones at the promoters of EMT-related markers, EMT-inducing transcription factors (EMT-TFs), and EMT-related long non-coding RNAs to control EMT. However, non-histone acetylation is a post-translational modification, and its effect on EMT mainly relies on modulating the acetylation of EMT marker proteins, EMT-TFs, and EMT-related signal transduction molecules. In addition, several inhibitors against KATs and KDACs have been developed, some of which can suppress the development of different cancers by targeting EMT. In this review, we discuss the complex biological roles and molecular mechanisms underlying histone acetylation and non-histone protein acetylation in the control of EMT, highlighting lysine acetylation as potential strategy for the treatment of cancer through the regulation of EMT.

Epigenetic regulation of epithelial to mesenchymal transition: a trophoblast perspective

Epigenetic changes alter expression of genes at both pre- and post-transcriptional levels without changing their DNA sequence. Accumulating evidence suggests that such changes can modify cellular behaviour and characteristics required during development and in response to various extracellular stimuli. Trophoblast cells develop from the outermost trophectoderm layer of the blastocyst and undergo many phenotypic changes as the placenta develops. One such phenotypic change is differentiation of the epithelial natured cytotrophoblasts into the mesenchymal natured extravillous trophoblasts. The extravillous trophoblasts are primarily responsible for invading into the maternal decidua and thus establishing connection with the maternal spiral arteries. Any dysregulation of this process can have adverse effects on the pregnancy outcome. Hence, tight regulation of this epithelial-mesenchymal transition is critical for successful pregnancy. This review summarizes the recent research on the epigenetic regulation of the epithelial-mesenchymal transition occurring in the trophoblast cells during placental development. The functional significance of chemical modifications of DNA and histone, which regulate transcription, as well as non-coding RNAs, which control gene expression post-transcriptionally, is discussed in relation to trophoblast biology.

Acupuncture and Moxibustion Inhibited Intestinal Epithelial-Mesenchymal Transition in Patients with Crohn's Disease Induced by TGF- β 1/Smad3/Snail Pathway: A Clinical Trial Study

OBJECTIVE

To explore whether acupuncture combined with moxibustion could inhibit epithelialmesenchymal transition in Crohn's disease by affecting the transforming growth factor β 1 (TGF- β 1)/Smad3/Snail pathway.

METHODS

Sixty-three patients with Crohn's disease were randomly divided into an observation group (31 cases) receiving moxibustion at 43 °C combined with acupuncture, and a control group (32 cases) receiving moxibustion at 37 °C combined with sham acupuncture using a random number table. Patients were treated for 12 weeks. Crohn's Disease Activity Index (CDAI) was used to evaluate disease activity. Hematoxylin-eosin staining and transmission electron microscopy were utilized to observe the morphological and ultrastructural changes. Immunohistochemistry was used to detect the expression of transforming growth factor β 1 (TGF-β 1), T β R1, T β R2, Smad3, Snail, E-cadherin and fibronectin in intestinal mucosal tissues.

RESULTS

The decrease of the CDAI score, morphological and ultrastructural changes were more significant in observation group. The expression levels of TGF- β 1, Tβ R2, Smad3, and Snail in the observation group were significantly lower than those before the treatment (P<0.05 or P<0.01). After treatment, the expression levels of TGF-β 1, TβR2, and Snail in the observation group were significantly lower than those in the control group (all P<0.05); compared with the control group, the expression of fibronectin in the observation group was significantly decreased, and the expression of E-cadherin was significantly increased (all P<0.05).

CONCLUSIONS

Moxibustion at 43 °C combined with acupuncture may suppress TGF-β 1/Smad3/Snail pathway-mediated epithelial-mesenchymal transition of intestinal epithelial cells in Crohn's disease patients by inhibiting the expression levels of TGF-β 1, Tβ R2, Smad3, and Snail. (Registration No. ChiCTR-IIR-16007751).

Multifunctional Role of Lipids in Modulating the Tumorigenic Properties of 4T1 Breast Cancer Cells

Tumor growth and progression are linked to an altered lipid metabolism in the tumor microenvironment (TME), including tumor cells and tumor-associated macrophages (TAMs). A growing number of lipid metabolism targeting drugs have shown efficacy in anti-tumor therapy. In addition, exogenously applied lipids and lipid analogues have demonstrated anti-tumor activities in several cancers, including breast cancer. In this study, we investigated the anti-tumor efficacies of the natural lipids palmitic acid (PA), sphingomyelin (SM), ceramide (Cer) and docosahexaenoic acid (DHA) on breast cancer cells. All tested lipids reduced the malignancy of breast cancer cells in vitro by impairing cell proliferation, migration and invasiveness. PA showed superior anti-tumor properties, as it additionally impaired cancer cell viability by inducing apoptosis, without affecting healthy cells. Co-culture experiments further demonstrated that Cer and PA reduced the immunosuppressive phenotype of M2 macrophages and the M2 macrophage-promoted the epithelial–mesenchymal transition (EMT) and migration of breast cancer cells. At the molecular level, this coincided with the up-regulation of E-cadherin. Our results highlight a powerful role for exogenously applied PA and Cer in reducing breast cancer tumorigenicity by simultaneously targeting cancer cells and M2 macrophages. Our findings support the notion that lipids represent alternative biocompatible therapeutic agents for breast cancer.

The Role of SMAD4 Inactivation in Epithelial-Mesenchymal Plasticity of Pancreatic Ductal Adenocarcinoma: The Missing Link?

Simple Summary

Pancreatic ductal adenocarcinoma (PDAC) is currently one of the deadliest cancers. Despite the progress that has been made in the research of patient care and the understanding of pancreatic cancer, the survival rate remains mediocre. SMAD4, a tumor-suppressor gene, is specifically inactivated in 50–55% of pancreatic cancers. The role of SMAD4 protein loss in PDAC remains controversial, but seems to be associated with worse overall survival and metastasis. Here, we review the function of SMAD4 inactivation in the context of a specific biological process called epithelial–mesenchymal transition, as it has been increasingly associated with tumor formation, metastasis and resistance to therapy. By improving our understanding of these molecular mechanisms, we hope to find new targets for therapy and improve the care of patients with PDAC.

Abstract

Pancreatic ductal adenocarcinoma (PDAC) presents a five-year survival rate of 10% and its incidence increases over the years. It is, therefore, essential to improve our understanding of the molecular mechanisms that promote metastasis and chemoresistance in PDAC, which are the main causes of death in these patients. SMAD4 is inactivated in 50% of PDACs and its loss has been associated with worse overall survival and metastasis, although some controversy still exists. SMAD4 is the central signal transducer of the transforming growth factor-beta (TGF-beta) pathway, which is notably known to play a role in epithelial–mesenchymal transition (EMT). EMT is a biological process where epithelial cells lose their characteristics to acquire a spindle-cell phenotype and increased motility. EMT has been increasingly studied due to its potential implication in metastasis and therapy resistance. Recently, it has been suggested that cells undergo EMT transition through intermediary states, which is referred to as epithelial–mesenchymal plasticity (EMP). The intermediary states are characterized by enhanced aggressiveness and more efficient metastasis. Therefore, this review aims to summarize and analyze the current knowledge on SMAD4 loss in patients with PDAC and to investigate its potential role in EMP in order to better understand its function in PDAC carcinogenesis.

The Role of ATRA, Natural Ligand of Retinoic Acid Receptors, on EMT-Related Proteins in Breast Cancer: Minireview

The knowledge of the structure, function, and abundance of specific proteins related to the EMT process is essential for developing effective diagnostic approaches to cancer with the perspective of diagnosis and therapy of malignancies. The success of all-trans retinoic acid (ATRA) differentiation therapy in acute promyelocytic leukemia has stimulated studies in the treatment of other tumors with ATRA. This review will discuss the impact of ATRA use, emphasizing epithelial-mesenchymal transition (EMT) proteins in breast cancer, of which metastasis and recurrence are major causes of death.

Cyclophilin A regulates A549 cells apoptosis via stabilizing Twist1 protein

Cyclophilin A (CypA) is an essential member of the immunophilin family. As an intracellular target of immunosuppressive drug cyclosporin A (CsA) or a peptidyl-prolyl cis/trans isomerase (PPIase), it catalyzes the cis-trans isomerization of proline amidic peptide bonds, through which, it regulates a variety of biological processes, such as intracellular signaling, transcription, and apoptosis. In this study, we found that intracellular CypA enhanced Twist1 phosphorylation at Ser68 and inhibited apoptosis in A549 cells. Mechanistically, CypA could mediate the phosphorylation of Twist1 at Ser68 via p38 MAPK, which inhibited its ubiquitination-mediated degradation. In addition, CypA increased Twist-p65 interaction and nuclear accumulation, which regulated Twist1-dependent expression of CDH1 and CDH2. Our findings collectively indicated the role of CypA in Twist1-mediated A549 cells apoptosis through stabilizing Twist1 protein.

Understanding the Complex Milieu of Epithelial-Mesenchymal Transition in Cancer Metastasis: New Insight Into the Roles of Transcription Factors

Epithelial-mesenchymal transition (EMT) is a physiological program during which polarised, immobile epithelial cells lose connection with their neighbours and are converted to migratory mesenchymal phenotype. Mechanistically, EMT occurs via a series of genetic and cellular events leading to the repression of epithelial-associated markers and upregulation of mesenchymal-associated markers. EMT is very crucial for many biological processes such as embryogenesis and ontogenesis during human development, and again it plays a significant role in wound healing during a programmed replacement of the damaged tissues. However, this process is often hijacked in pathological conditions such as tumour metastasis, which constitutes the most significant drawback in the fight against cancer, accounting for about 90% of cancer-associated mortality globally. Worse still, metastatic tumours are not only challenging to treat with the available conventional radiotherapy and surgical interventions but also resistant to several cytotoxic agents during treatment, owing to their anatomically diffuse localisation in the body system. As the quest to find an effective method of addressing metastasis in cancer intervention heightens, understanding the molecular interplay involving the signalling pathways, downstream effectors, and their interactions with the EMT would be an important requisite while the challenges of metastasis continue to punctuate. Unfortunately, the molecular underpinnings that govern this process remain to be completely illuminated. However, it is becoming increasingly clear that EMT, which initiates every episode of metastasis, significantly requires some master regulators called EMT transcription factors (EMT-TFs). Thus, this review critically examines the roles of TFs as drivers of molecular rewiring that lead to tumour initiation, progression, EMT, metastasis, and colonisation. In addition, it discusses the interaction of various signalling molecules and effector proteins with these factors. It also provides insight into promising therapeutic targets that may inhibit the metastatic process to overcome the limitation of "undruggable" cancer targets in therapeutic design and upturn the current spate of drug resistance. More so, it extends the discussion from the basic understanding of the EMT binary switch model, and ultimately unveiling the E/M cellular plasticity along a phenotypic spectrum via multiple trans-differentiations. It wraps up on how this knowledge update shapes the diagnostic and clinical approaches that may demand a potential shift in investigative paradigm using novel technologies such as single-cell analyses to improve overall patient survival.

Atractylodin Suppresses TGF-β-Mediated Epithelial-Mesenchymal Transition in Alveolar Epithelial Cells and Attenuates Bleomycin-Induced Pulmonary Fibrosis in Mice

Idiopathic pulmonary fibrosis (IPF) is characterized by fibrotic change in alveolar epithelial cells and leads to the irreversible deterioration of pulmonary function. Transforming growth factor-beta 1 (TGF-β1)-induced epithelial-mesenchymal transition (EMT) in type 2 lung epithelial cells contributes to excessive collagen deposition and plays an important role in IPF. Atractylodin (ATL) is a kind of herbal medicine that has been proven to protect intestinal inflammation and attenuate acute lung injury. Our study aimed to determine whether EMT played a crucial role in the pathogenesis of pulmonary fibrosis and whether EMT can be utilized as a therapeutic target by ATL treatment to mitigate IPF. To address this topic, we took two steps to investigate: 1. Utilization of anin vitro EMT model by treating alveolar epithelial cells (A549 cells) with TGF-β1 followed by ATL treatment for elucidating the underlying pathways, including Smad2/3 hyperphosphorylation, mitogen-activated protein kinase (MAPK) pathway overexpression, Snail and Slug upregulation, and loss of E-cadherin. Utilization of an in vivo lung injury model by treating bleomycin on mice followed by ATL treatment to demonstrate the therapeutic effectiveness, such as, less collagen deposition and lower E-cadherin expression. In conclusion, ATL attenuates TGF-β1-induced EMT in A549 cells and bleomycin-induced pulmonary fibrosis in mice.

ZNF521 Enhances MLL-AF9-Dependent Hematopoietic Stem Cell Transformation in Acute Myeloid Leukemias by Altering the Gene Expression Landscape

Leukemias derived from the MLL-AF9 rearrangement rely on dysfunctional transcriptional networks. ZNF521, a transcription co-factor implicated in the control of hematopoiesis, has been proposed to sustain leukemic transformation in collaboration with other oncogenes. Here, we demonstrate that ZNF521 mRNA levels correlate with specific genetic aberrations: in particular, the highest expression is observed in AMLs bearing MLL rearrangements, while the lowest is detected in AMLs with FLT3-ITD, NPM1, or CEBPα double mutations. In cord blood-derived CD34⁺ cells, enforced expression of ZNF521 provides a significant proliferative advantage and enhances MLL-AF9 effects on the induction of proliferation and the expansion of leukemic progenitor cells. Transcriptome analysis of primary CD34⁺ cultures displayed subsets of genes up-regulated by MLL-AF9 or ZNF521 single transgene overexpression as well as in MLL-AF9/ZNF521 combinations, at either the early or late time points of an in vitro leukemogenesis model. The silencing of ZNF521 in the MLL-AF9 + THP-1 cell line coherently results in an impairment of growth and clonogenicity, recapitulating the effects observed in primary cells. Taken together, these results underscore a role for ZNF521 in sustaining the self-renewal of the immature AML compartment, most likely through the perturbation of the gene expression landscape, which ultimately favors the expansion of MLL-AF9-transformed leukemic clones.

Proteomics Analysis of Lymphatic Metastasis-Related Proteins Using Highly Metastatic Human Melanoma Cells Originated by Sequential in Vivo Implantation

Metastasis of cancer cells to lymph nodes (LN) is a common modality of metastasis in clinical settings, but the mechanisms involved in lymphatic metastasis remain unclear compared to hematogenous metastasis to bones and the brain. To elucidate the molecular mechanisms responsible for melanoma LN metastasis, we first generated LN metastasis-prone melanoma cells (C8161F2) by the sequential in vivo transplantation of parental melanoma cells (C8161F0). Although the in vitro/in vivo proliferative potential of these melanoma cells were similar, the metastatic potential of the C8161F2 for LNs was significantly enhanced. We then conducted a proteomics analysis to identify the proteins and pathways that contribute to LN metastasis. We identified six proteins (three: up-regulated and three: down-regulated) whose expressions were statistically significantly different by more than 2-fold in the two cell groups. Some of these genes are responsible for the activation of the transforming growth factor-β (TGF-β)-related pathway, a well-known inducer of epithelial-mesenchymal transition (EMT). In addition, a gene ontology analysis revealed that the enhanced cell-cell adhesion appears to be involved in lymphatic metastasis. In conclusion, we established highly lymphatic metastatic melanoma cells, which would be valuable for studies of the molecular mechanisms responsible for lymphatic metastasis.

Role of Metastasis-Related microRNAs in Prostate Cancer Progression and Treatment

Simple Summary

In this review article we summarize the current literature on the pro- and anti-metastatic roles of distinct microRNAs in prostate cancer with a particular focus on their impact on invasion, migration and epithelial-to-mesenchymal transition. Moreover, we give a brief overview on how this knowledge developed so far into novel therapeutic approaches to target metastatic prostate cancer.

Abstract

Prostate cancer (PCa) is one of the most prevalent cancer types in males and the consequences of its distant metastatic deposits are the leading cause of PCa mortality. Therefore, identifying the causes and molecular mechanisms of hematogenous metastasis formation is of considerable clinical importance for the future development of improved therapeutic approaches. MicroRNAs (miRNAs) are small non-coding RNAs that regulate gene expression at the post-transcriptional level by targeting messenger RNAs. Numerous studies have identified miRNAs as promotors or inhibitors of metastasis and revealed, in part, their targeting pathways in PCa. Because miRNAs are remarkably stable and can be detected in both tissue and body fluid, its potential as specific biomarkers for metastasis and therapeutic response is also currently under preclinical evaluation. In the present review, we focus on miRNAs that are supposed to initiate or suppress metastasis by targeting several key mRNAs in PCa. Metastasis-suppressing miRNAs include miR-33a-5p, miR-34, miR-132 and miR-212, miR-145, the miR-200 family (incl. miR-141-3p), miR-204-5p, miR-532-3p, miR-335, miR-543, miR-505-3p, miR 19a 3p, miR-802, miR-940, and miR-3622a. Metastasis-promoting RNAs, such as miR-9, miR-181a, miR-210-3, miR-454, miR-671-5p, have been shown to increase the metastatic potential of PCa cells. Other metastasis-related miRNAs with conflicting reports in the literature are also discussed (miR-21 and miR-186). Finally, we summarize the recent developments of miRNA-based therapeutic approaches, as well as current limitations in PCa. Taken together, the metastasis-controlling miRNAs provide the potential to be integrated in the strategy of diagnosis, prognosis, and treatment of metastatic PCa. Nevertheless, there is still a lack of consistency between certain miRNA signatures and reproducibility, which impedes clinical implementation.

Cisplatin Plus Cetuximab Inhibits Cisplatin-Resistant Human Oral Squamous Cell Carcinoma Cell Migration and Proliferation but Does Not Enhance Apoptosis

Cisplatin is among the most widely used anticancer drugs used in the treatment of several malignancies, including oral cancer. However, cisplatin treatment often promotes chemical resistance, subsequently causing treatment failure. Several studies have shown that epidermal growth factor receptors (EGFRs) play a variety of roles in cancer progression and overcoming cisplatin resistance. Therefore, this study focused on EGFR inhibitors used in novel targeted therapies as a method to overcome this resistance. We herein aimed to determine whether the combined effects of cisplatin and cetuximab could enhance cisplatin sensitivity by inhibiting the epithelial-to-mesenchymal transition (EMT) process in cisplatin-resistant cells. In vitro analyses of three cisplatin-resistant oral squamous cell carcinoma cells, which included cell proliferation assay, combination index calculation, cell cytotoxicity assay, live/dead cell count assay, Western blot assay, propidium iodide staining assay, scratch assay, and qRT-PCR assay were then conducted. Our results showed that a cisplatin/cetuximab combination treatment inhibited cell proliferation, cell motility, and N-cadherin protein expression but induced E-cadherin and claudin-1 protein expression. Although the combination of cisplatin and cetuximab did not induce apoptosis of cisplatin-resistant cells, it may be useful in treating oral cancer patients with cisplatin resistance given that it controls cell motility and EMT-related proteins.