Unresolved Complexity in the Gene Regulatory Network Underlying EMT

The role of circular RNA in preeclampsia: From pathophysiological mechanism to clinical application

Preeclampsia (PE) is a common pregnancy-induced hypertension disorder that poses a significant threat to the health of pregnant women and fetuses, and has become a leading cause of maternal, fetal, and neonatal mortality. Currently, the therapy strategy for PE is mainly prevention management and symptomatic treatment, and only delivery can completely terminate PE. Therefore, a deeper understanding of the pathogenesis of PE is needed to make treatment and prevention more effective and targeted. With the deepening of molecular etiology research, circular RNAs (circRNAs) have been found to be widely involved in various processes of PE pathogenesis. As a kind of RNA with a special "head to tail" loop structure, the characteristics of circRNAs enable them to play diverse roles in the pathophysiology of PE, and can also serve as ideal biomarkers for early prediction and monitoring progression of PE. In this review, we summarized the latest research on PE-related circRNAs, trying to elucidate the unique or shared roles of circRNAs in various pathophysiological mechanisms of PE, aiming to provide a whole picture of current research on PE-related circRNAs, and extend a new perspective for the precise screening and targeted therapy of PE.

KDM5A noncanonically binds antagonists MLL1/2 to mediate gene regulation and promotes epithelial to mesenchymal transition

Differential expression of genes involved in certain processes is a collaborative outcome of crosstalk between signalling molecules and epigenetic modifiers. In response to environmental stimulus, interplay between transcription factors and epigenetic modifiers together dictates the regulation of genes. MLLs and KDM5A are functionally antagonistic proteins, as one acts as a writer and the other erases the active chromatin mark, i.e., H3K4me3. KDM5A influences the process of EMT by binding to both epithelial and mesenchymal gene promoters. Through this work, we show that when bound to E-cadherin promoter, KDM5A acts as a classical repressor by demethylating H3K4me3, but on mesenchymal markers, it acts as a transcriptional activator by inhibiting the activity of HDACs and increasing H3K18ac. Further, through our chromatin immunoprecipitation experiments, we observed a co-occupancy of KDM5A with MLLs, we tested whether KDM5A might physically interact with MLLs and WDR5, and here we provide experimental evidence that KDM5A indeed interacts with MLLs and WDR5.

NSG1 promotes glycolytic metabolism to enhance Esophageal squamous cell carcinoma EMT process by upregulating TGF-β

As a highly enriched endosomal protein within neuronal cells, NSG1 has been discovered to facilitate the process of epithelial-mesenchymal transition (EMT) in esophageal squamous cell carcinoma (ESCC). However, the precise mechanisms behind this phenomenon have yet to be elucidated. The pivotal role of transforming growth factor-β (TGF-β) in triggering the EMT and its significant contribution towards tumor metabolic reprogramming-responsible for EMT activation-has been robustly established. Nevertheless, the extent of TGF-β involvement in the NSG1-mediated EMT within ESCC and the processes through which metabolic reprogramming participates remain ambiguous. We accessed an array of extensive public genome databases to analyze NSG1 expression in ESCC. Regulation of TGF-β by NSG1 was analyzed by transcriptome sequencing, quantitative Real-Time PCR (qRT-PCR), co-immunoprecipitation (CO-IP), and immunofluorescence (IF). Additionally, cellular functional assays and western blot analyses were conducted to elucidate the effect of NSG1 on TGF-β/Smad signaling pathway, as well as its role in ESCC cell metastasis and proliferation. We validated the influence of the NSG1/TGF-β axis on metabolic reprogramming in ESCC by measuring extracellular acidification, glucose uptake, and lactate production. Our findings identify an oncogenic role for NSG1 in ESCC and show a correlation between high NSG1 expression and poor prognosis in ESCC patients. Additional research indicated TGF-β's involvement in the NSG1-induced EMT process. From a mechanistic perspective, NSG1 upregulates TGF-β, activating the TGF-β/Smad signaling pathway and subsequently fostering the EMT process by inducing cell metabolic reprogramming-evident from elevated glycolysis levels. In conclusion, our study highlights the NSG1/TGF-β axis as a promising therapeutic target for ESCC.

Comparison of Tumour-Specific Phenotypes in Human Primary and Expandable Pancreatic Cancer Cell Lines

There is an ongoing need for patient-specific chemotherapy for pancreatic cancer. Tumour cells isolated from human tissues can be used to predict patients' response to chemotherapy. However, the isolation and maintenance of pancreatic cancer cells is challenging because these cells become highly vulnerable after losing the tumour microenvironment. Therefore, we investigated whether the cells retained their original characteristics after lentiviral transfection and expansion. Three human primary pancreatic cancer cell lines were lentivirally transduced to create expandable (Ex) cells which were then compared with primary (Pri) cells. No obvious differences in the morphology or epithelial-mesenchymal transition (EMT) were observed between the primary and expandable cell lines. The two expandable cell lines showed higher proliferation rates in the 2D and 3D models. All three expandable cell lines showed attenuated migratory ability. Differences in gene expression between primary and expandable cell lines were then compared using RNA-Seq data. Potential target drugs were predicted by differentially expressed genes (DEGs), and differentially expressed pathways (DEPs) related to tumour-specific characteristics such as proliferation, migration, EMT, drug resistance, and reactive oxygen species (ROS) were investigated using the Kyoto Encyclopedia of Genes and Genomes (KEGG) database. We found that the two expandable cell lines expressed similar chemosensitivity and redox-regulatory capability to gemcitabine and oxaliplatin in the 2D model as compared to their counterparts. In conclusion, we successfully generated expandable primary pancreatic cancer cell lines using lentiviral transduction. These expandable cells not only retain some tumour-specific biological traits of primary cells but also show an ongoing proliferative capacity, thereby yielding sufficient material for drug response assays, which may provide a patient-specific platform for chemotherapy drug screening.

Unraveling the Molecular Puzzle: Exploring Gene Networks across Diverse EMT Status of Cell Lines

Understanding complex disease mechanisms requires a comprehensive understanding of the gene regulatory networks, as complex diseases are often characterized by the dysregulation and dysfunction of molecular networks, rather than abnormalities in single genes. Specifically, the exploration of cell line-specific gene networks can provide essential clues for precision medicine, as this methodology can uncover molecular interplays specific to particular cell line statuses, such as drug sensitivity, cancer progression, etc. In this article, we provide a comprehensive review of computational strategies for cell line-specific gene network analysis: (1) cell line-specific gene regulatory network estimation and analysis of gene networks under varying epithelial-mesenchymal transition (EMT) statuses of cell lines; and (2) an explainable artificial intelligence approach for interpreting the estimated massive multiple EMT-status-specific gene networks. The objective of this review is to help readers grasp the concept of computational network biology, which holds significant implications for precision medicine by offering crucial clues.

xcore: an R package for inference of gene expression regulators

BACKGROUND

Elucidating the Transcription Factors (TFs) that drive the gene expression changes in a given experiment is a common question asked by researchers. The existing methods rely on the predicted Transcription Factor Binding Site (TFBS) to model the changes in the motif activity. Such methods only work for TFs that have a motif and assume the TF binding profile is the same in all cell types.

RESULTS

Given the wealth of the ChIP-seq data available for a wide range of the TFs in various cell types, we propose that gene expression modeling can be done using ChIP-seq "signatures" directly, effectively skipping the motif finding and TFBS prediction steps. We present xcore, an R package that allows TF activity modeling based on ChIP-seq signatures and the user's gene expression data. We also provide xcoredata a companion data package that provides a collection of preprocessed ChIP-seq signatures. We demonstrate that xcore leads to biologically relevant predictions using transforming growth factor beta induced epithelial-mesenchymal transition time-courses, rinderpest infection time-courses, and embryonic stem cells differentiated to cardiomyocytes time-course profiled with Cap Analysis Gene Expression.

CONCLUSIONS

xcore provides a simple analytical framework for gene expression modeling using linear models that can be easily incorporated into differential expression analysis pipelines. Taking advantage of public ChIP-seq databases, xcore can identify meaningful molecular signatures and relevant ChIP-seq experiments.

High-content screening of active components of Traditional Chinese Medicine inhibiting TGF-β-induced cell EMT

The epithelial mesenchymal transition (EMT) has roles in metastasis and invasion during fibrotic diseases and cancer progression. Some Traditional Chinese Medicines (TCMs) have shown inhibitory effects with respect to the EMT. The current study attempted to establish a multiparametric high-content method to screen for active monomeric compounds in TCM with the ability to target cellular EMT by assessing phenotypic changes. A total of 306 monomeric compounds from the MedChemExpress (MCE) compound library were screened by the high-content screening (HCS) system and 5 compounds with anti-EMT activity, including camptothecin (CPT), dimethyl curcumin (DMC), artesunate (ART), sinapine (SNP) and berberine (BER) were identified. To confirm anti-EMT activity, expression of EMT markers was assessed by qRT-PCR and Western blotting, and cell adhesion and migration measured by cell function assays. The results revealed that CPT, DMC, ART, SNP and BER inhibited transforming growth factor-β1 (TGF-β1)-induced expression of vimentin and α-SMA, upregulated expression of E-cadherin, increased cell adhesion and reduced cell migration. In summary, by quantifying the cell morphological changes during TGF-β1-induced EMT through multi-parametric analysis, TCM compounds with anti-EMT activity were successfully screened using the HCS system, a faster and more economical approach than conventional methods.

Ubiquitination and deubiquitination in the regulation of epithelial-mesenchymal transition in cancer: Shifting gears at the molecular level

The process of conversion of non-motile epithelial cells to their motile mesenchymal counterparts is known as epithelial-mesenchymal transition (EMT), which is a fundamental event during embryonic development, tissue repair, and for the maintenance of stemness. However, this crucial process is hijacked in cancer and becomes the means by which cancer cells acquire further malignant properties such as increased invasiveness, acquisition of stem cell-like properties, increased chemoresistance, and immune evasion ability. The switch from epithelial to mesenchymal phenotype is mediated by a wide variety of effector molecules such as transcription factors, epigenetic modifiers, post-transcriptional and post-translational modifiers. Ubiquitination and de-ubiquitination are two post-translational processes that are fundamental to the ubiquitin-proteasome system (UPS) of the cell, and the shift in equilibrium between these two processes during cancer dictates the suppression or activation of different intracellular processes, including EMT. Here, we discuss the complex and dynamic relationship between components of the UPS and EMT in cancer.

Rosmarinic acid ameliorates renal interstitial fibrosis by inhibiting the phosphorylated-AKT mediated epithelial-mesenchymal transition in vitro and in vivo

Indoxyl sulfate (IS), a uremic toxin, causes chronic kidney disease (CKD) progression via renal fibrosis. Epithelial-mesenchymal transition (EMT) is a crucial feature of renal fibrosis. Rosmarinic acid (RA) is an ester of caffeic acid and 3,4-dihydroxyphenylacetic acid with a wide range of desirable biological activities. In this study, we investigated whether RA exerted anti-renal fibrosis effects and its related mechanisms in a unilateral ureteral obstruction (UUO) mouse model. C57BL/6 mice were orally administered RA (10 and 20 mg kg-1 d-1) for 7 consecutive days before and after UUO surgery. The mice were then sacrificed to collect the blood and kidneys. Hematoxylin and eosin (H&E) and Masson's trichrome staining were used to evaluate the renal injury and function. Immunohistochemical analysis, reverse transcription-polymerase chain reaction (RT-PCR), and western blotting were used to detect the expression levels of EMT markers. In vitro studies were performed using the IS-stimulated NRK-52E cell line. Here, the pathological changes, collagen deposition, and mRNA and protein expression levels of profibrotic factors and fibrotic markers were found to be significantly elevated in the kidneys of UUO mice. We found that RA administration significantly ameliorated UUO-induced kidney damage by reversing abnormal serum creatinine and blood urea nitrogen levels. It was found that RA treatment decreased the expression levels of alpha-smooth muscle actin (α-SMA), collagen I, fibronectin, transforming growth factor (TGF)-β1, vimentin and phosphorylated AKT (p-AKT) while increasing the E-cadherin expression in both UUO kidneys and IS-treated NRK-52E cells. Our results demonstrate that RA may be a promising therapeutic agent for renal interstitial fibrosis.

The Entanglement between Mitochondrial DNA and Tumor Metastasis

Simple Summary

Mitochondrial dysfunction is one of the main features of cancer cells. As genetic material in mitochondria, mitochondrial DNA (mtDNA) variations and dysregulation of mitochondria-encoded genes have been shown to correlate with survival outcomes in cancer patients. Cancer metastasis is often a major cause of treatment failure, which is a multi-step cascade process. With the development of gene sequencing and in vivo modeling technology, the role of mtDNA in cancer metastasis has been continuously explored. Our review systematically provides a summary of the multiple roles of mtDNA in cancer metastasis and presents the broad prospects for mtDNA in cancer prediction and therapy.

Abstract

Mitochondrial DNA, the genetic material in mitochondria, encodes essential oxidative phosphorylation proteins and plays an important role in mitochondrial respiration and energy transfer. With the development of genome sequencing and the emergence of novel in vivo modeling techniques, the role of mtDNA in cancer biology is gaining more attention. Abnormalities of mtDNA result in not only mitochondrial dysfunction of the the cancer cells and malignant behaviors, but regulation of the tumor microenvironment, which becomes more aggressive. Here, we review the recent progress in the regulation of cancer metastasis using mtDNA and the underlying mechanisms, which may identify opportunities for finding novel cancer prediction and therapeutic targets.

Exosomes Regulate the Epithelial-Mesenchymal Transition in Cancer

Exosomes are important mediators of intercellular communication and participate in complex biological processes by transferring a variety of bioactive molecules between cells. Epithelial–mesenchymal transition (EMT) is a process in which the cell phenotype changes from epithelioid to mesenchymal-like. EMT is also an important process for cancer cells by which they acquire invasive and metastatic capabilities, which aggravates the degree of tumor malignancy. Numerous studies have demonstrated that exosomes encapsulate various components, such as microRNAs and proteins, and transfer information between tumor cells or between tumor cells and the tumor microenvironment, thereby regulating the EMT process. Exosomes can also be used for cancer diagnosis and treatment or as a drug delivery platform. Thus, they can be used as a therapeutic tool to control the occurrence of EMT and affect cancer progression. In this review, we summarize the latest research advancements in the regulation of the EMT process in tumor cells by the contents of exosomes. Furthermore, we discuss the potential and challenges of using exosomes as a tool for cancer treatment.

EPB41L5 promotes EMT through the ERK/p38 MAPK signaling pathway in esophageal squamous cell carcinoma

BACKGROUND

Esophageal squamous cell carcinoma (ESCC) is one of the most common malignant tumors worldwide and is characterized by activation of epithelial-mesenchymal transition (EMT). EPB41L5 is regarded as a key factor in the progression of EMT and metastasis in various kinds of cancers, although the role and mechanism of EPB41L5 in ESCC have not yet been elucidated. In addition, tumor cells can acquire enhanced aggressiveness and a mesenchymal phenotype through phosphorylation of MAPK signaling pathway components. Here, we intend to explore whether EPB41L5 can regulate the EMT process in ESCC and reveal whether the MAPK signaling pathway is involved.

METHODS

We compared the expression level of EPB41L5 with the prognostic characteristics of 100 ESCC patients to hypothesize the role of EPB41L5 in the progression of ESCC. Furthermore, in vivo and in vitro experiments were conducted to verify the conclusions from the analysis of clinical specimens and investigate the underlying mechanism by which EPB41L5 contributes to ESCC.

RESULTS

We discovered that EPB41L5 was overexpressed in ESCC and that higher EPB41L5 expression was related to higher TNM stage, a higher incidence of lymphatic metastasis and worse prognosis. Moreover, using ESCC cells and nude mouse models, we found that EPB41L5 promoted EMT, proliferation, migration and invasion in ESCC. Mechanistically, activation of phosphorylation in the ERK/p38 MAPK signaling pathway was involved in the EPB41L5-mediated regulation of EMT.

CONCLUSION

In conclusion, our findings suggest that EPB41L5 plays a critical role in the regulation of EMT and the progression of ESCC.

Biological Functions of Diallyl Disulfide, a Garlic-Derived Natural Organic Sulfur Compound

Garlic is widely accepted as a functional food and an excellent source of pharmacologically active ingredients. Diallyl disulfide (DADS), a major bioactive component of garlic, has several beneficial biological functions, including anti-inflammatory, antioxidant, antimicrobial, cardiovascular protective, neuroprotective, and anticancer activities. This review systematically evaluated the biological functions of DADS and discussed the underlying molecular mechanisms of these functions. We hope that this review provides guidance and insight into the current literature and enables future research and the development of DADS for intervention and treatment of multiple diseases.

Mnt Represses Epithelial Identity To Promote Epithelial-to-Mesenchymal Transition

The multistep process of epithelial-to-mesenchymal transition (EMT), whereby static epithelial cells become migratory mesenchymal cells, plays a critical role during various developmental contexts, wound healing, and pathological conditions such as cancer metastasis. Despite the established function of basic helix-loop-helix (bHLH) transcription factors (TFs) in cell fate determination, only a few have been examined for their role in EMT. Here, using transcriptome analysis of distinct stages during stepwise progression of transforming growth factor beta (TGFβ)-induced EMT in mammary epithelial cells, we revealed distinct categories of bHLH TFs that show differential expression kinetics during EMT. Using a short interfering RNA-mediated functional screen for bHLH TFs during EMT, we found Max network transcription repressor (MNT) to be essential for EMT in mammary epithelial cells. We show that the depletion of MNT blocks TGFβ-induced morphological changes during EMT, and this is accompanied by derepression of a large number of epithelial genes. We show that MNT mediates the repression of epithelial identity genes during EMT by recruiting HDAC1 and mediating the loss of H3K27ac and chromatin accessibility. Lastly, we show that MNT is expressed at higher levels in EMT-High breast cancer cells and is required for their migration. Taken together, these findings establish MNT as a critical regulator of cell fate changes during mammary EMT. IMPORTANCE The bHLH TF Mnt promotes epithelial to mesenchymal transition through epigenetic repression of the epithelial gene expression program.

Circ_0007121 Facilitates Trophoblastic Cell Proliferation, Migration, and Invasion via the Regulation of the miR-421/ZEB1 Axis in Preeclampsia

Noncoding circular RNAs (circRNAs) have participated in the progression of preeclampsia (PE) via inhibiting microRNAs (miRNAs) to regulate gene expression. This study was designed to explore the miRNA/mRNA mechanism of hsa_circ_0007121 (circ_0007121) in PE. The expression detection of circ_0007121, microRNA-421 (miR-421), and zinc finger E-box binding homeobox 1 (ZEB1) was performed by quantitative real-time polymerase chain reaction (qRT-PCR). Cell proliferation was analyzed by Cell Counting Kit-8 (CCK-8) assay. Transwell assay was used to determine cell migration and invasion. Cell apoptosis was evaluated using flow cytometry. The protein levels of epithelial-mesenchymal transition (EMT) markers and ZEB1 were measured via western blot. The interaction between miR-421 and circ_0007121 or ZEB1 was validated by dual-luciferase reporter assay. The expression detection indicated that circ_0007121 was downregulated in PE patients and the clinical data revealed that circ_0007121 was related to PE. The upregulation of circ_0007121 promoted cell proliferation, migration, invasion, and EMT in trophoblastic cells. Furthermore, circ_0007121 was identified as a sponge of miR-421 and the function of circ_0007121 was dependent on the sponge effect on miR-421. Moreover, ZEB1 was a target of miR-421 and circ_0007121/miR-421 axis could regulate the expression of ZEB1. In addition, miR-421 overexpression repressed trophoblastic cell behaviors through downregulating the ZEB1 level. Altogether, circ_0007121 contributed to the development of trophoblastic cells by regulating the miR-421/ZEB1 axis.

FOXD1 promotes EMT and cell stemness of oral squamous cell carcinoma by transcriptional activation of SNAI2

Background

Epithelial-mesenchymal transition (EMT) and cell stemness are implicated in the initiation and progression of oral squamous cell carcinoma (OSCC). Revealing the intrinsic regulatory mechanism may provide effective therapeutic targets for OSCC.

Results

In this study, we found that Forkhead box D1 (FOXD1) was upregulated in OSCC compared with normal samples. Patients with a higher FOXD1 expression had a poorer overall survival and disease-free survival. Immunohistochemical staining results showed that FOXD1 expression was related to the clinical stage and relapse status of OSCC patients. When FOXD1 expression was knocked down in CAL27 and SCC25 cells, the migration, invasion, colony formation, sphere formation, and proliferation abilities decreased. Moreover, EMT and stemness-related markers changed remarkably, which indicated that the EMT process and cell stemness were inhibited. Conversely, overexpression of FOXD1 promoted EMT and cell stemness. Further study demonstrated that FOXD1 could bind to the promoter region and activate the transcription of SNAI2. In turn, the elevated SNAI2 affected EMT and cell stemness. An in vivo study showed that FOXD1-overexpressing CAL27 cells possessed a stronger tumorigenic ability.

Conclusions

Our findings revealed a novel mechanism in regulating EMT and cell stemness and proposed FOXD1 as a potential marker for the diagnosis and treatment of OSCC.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13578-021-00671-9.

Regulatory roles of osteopontin in human lung cancer cell epithelial-to-mesenchymal transitions and responses

BACKGROUND

Lung cancer is still the main cause of death in patients with cancer, due to poor understanding of intracellular regulations. Of those, osteopontin (OPN) may induce the epithelial-to-mesenchymal transition (EMT) to promote tumor cell metastasis. The present study aims to evaluate the regulatory mechanism of internal and external OPN in the development of lung cancer.

METHODS

We evaluated genetic variations and different bioinformatics of genes in chromosome 4 among subtypes of lung cancer using global databases. We validated the expression of OPN and EMT-related proteins (e.g., E-cadherin, vimentin) in 208 non-small-cell lung cancer (NSCLC) tumors and the adjacent nontumorous tissues, further to explore the function of OPN in the progression of lung cancer, with a focus on a potential communication between OPN and EMT in the lung cancer.

RESULTS

We found that OPN might act as a target molecule in lung cancer, which is associated with lymph node metastasis, postresection recurrence/metastasis, and prognosis of patients with lung cancer. Biological behaviors and pathological responses of OPN varied among diseases, challenges, and severities. Overexpression of OPN was correlated with the existence of EMT in lung cancer tissues. Internal and external OPN plays the decisive roles in lung cancer cell movement, proliferation, and EMT formation, through the upregulation of OPN-PI3K and OPN-MEK pathways. PI3K and MEK inhibitors downregulated the process of EMT and biological behaviors of lung cancer cells, probably through altering vimentin-associated cytoskeletons.

CONCLUSION

OPN can be a metastasis-associated or specific biomarker for lung cancer and a potential target for antimetastatic treatment.

New insight towards development of paclitaxel and docetaxel resistance in cancer cells: EMT as a novel molecular mechanism and therapeutic possibilities

Epithelial-to-mesenchymal transition (EMT) mechanism is responsible for metastasis and migration of cancer cells to neighboring cells and tissues. Morphologically, epithelial cells are transformed to mesenchymal cells, and at molecular level, E-cadherin undergoes down-regulation, while an increase occurs in N-cadherin and vimentin levels. Increasing evidence demonstrates role of EMT in mediating drug resistance of cancer cells. On the other hand, paclitaxel (PTX) and docetaxel (DTX) are two chemotherapeutic agents belonging to taxene family, capable of inducing cell cycle arrest in cancer cells via preventing microtubule depolymerization. Aggressive behavior of cancer cells resulted from EMT-mediated metastasis can lead to PTX and DTX resistance. Upstream mediators of EMT such as ZEB1/2, TGF-β, microRNAs, and so on are involved in regulating response of cancer cells to PTX and DTX. Tumor-suppressing factors inhibit EMT to promote PTX and DTX sensitivity of cancer cells. Furthermore, three different strategies including using anti-tumor compounds, gene therapy and delivery systems have been developed for suppressing EMT, and enhancing cytotoxicity of PTX and DTX against cancer cells that are mechanistically discussed in the current review.

microRNA-377-3p inhibits osteosarcoma progression by targeting CUL1 and regulating Wnt/β-catenin signaling pathway

OBJECTIVE

Emerging studies highlight the crucial effects of microRNAs on cancer initiation and malignant progression of various tumors. This study focused on the biological effect of miR-377-3p on CUL1 and epithelial-mesenchymal transition (EMT) and Wnt/β-catenin pathways in osteosarcoma (OS).

METHODS

We performed quantitative real-time polymerase chain reaction (qRT-PCR) to analyze miR-377-3p and CUL1 expression levels in OS tissues and MG-63 cells. Then, cell counting kit (CCK)-8 and Transwell assay were used to examine the functions of miR-377-3p in OS cell growth and metastasis abilities. Meanwhile, luciferase reporter assay was used to validate CUL1 as direct target of miR-377-3p. qRT-PCR and Western blot were then carried out to detect the impact of miR-377-3p on EMT and Wnt/β-catenin pathways. Tumor xenograft models were established to further examine the effects of miR-377-3p on OS tumorigenesis in vivo.

RESULTS

miR-377-3p downregulation was frequently identified in OS tissues and cells, which was associated with worse prognosis of OS patients. Functional experiments showed miR-377-3p restoration could dramatically repress OS cell growth and migration by regulation of EMT and Wnt/β-catenin pathways. Moreover, luciferase reporter assay revealed that CUL1 acted as a functional target of miR-377-3p. Additionally, the elevated CUL1 expressions in OS tissues also indicated poor prognosis of OS patients. Furthermore, the OS tumor growth was also obviously inhibited by miR-377-3p overexpression in vivo.

CONCLUSIONS

Collectively, all the above findings revealed that miR-377-3p exerted anti-OS functions via CUL1 and EMT and Wnt/β-catenin pathways. These results may contribute to the development of clinical OS treatment.

Loss of lncRNA SNHG8 promotes epithelial-mesenchymal transition by destabilizing CDH1 mRNA

Long non-coding RNAs (lncRNAs) are widely involved in a variety of biological processes, including epithelial-mesenchymal transition (EMT). In the current study, we found that lncRNA small nucleolar RNA host gene 8 (SNHG8) was tightly correlated with EMT-associated gene signatures, and was down-regulated by Zinc finger E-box-binding homeobox 1 (ZEB1) during EMT progress. Functionally, knockdown of SNHG8 induced EMT in epithelial cells, through destabilizing the CDH1 mRNA dependent on a 17-nucleotide sequence shared by SNHG8 and CDH1. In addition, analysis with public database showed that SNHG8 tended to be down-regulated in different cancer types and the lower expression of SNHG8 predicted poorer prognosis. Taken together, our study reports a ZEB1-repressed lncRNA SNHG8 which is important for stabilizing CDH1 mRNA, thereby maintaining the epithelial status of epithelial cells.

Epigenetics in Breast Cancer Therapy-New Strategies and Future Nanomedicine Perspectives

Epigenetic dysregulation has been recognized as a critical factor contributing to the development of resistance against standard chemotherapy and to breast cancer progression via epithelial-to-mesenchymal transition. Although the efficacy of the first-generation epigenetic drugs (epi-drugs) in solid tumor management has been disappointing, there is an increasing body of evidence showing that epigenome modulation, in synergy with other therapeutic approaches, could play an important role in cancer treatment, reversing acquired therapy resistance. However, the epigenetic therapy of solid malignancies is not straightforward. The emergence of nanotechnologies applied to medicine has brought new opportunities to advance the targeted delivery of epi-drugs while improving their stability and solubility, and minimizing off-target effects. Furthermore, the omics technologies, as powerful molecular epidemiology screening tools, enable new diagnostic and prognostic epigenetic biomarker identification, allowing for patient stratification and tailored management. In combination with new-generation epi-drugs, nanomedicine can help to overcome low therapeutic efficacy in treatment-resistant tumors. This review provides an overview of ongoing clinical trials focusing on combination therapies employing epi-drugs for breast cancer treatment and summarizes the latest nano-based targeted delivery approaches for epi-drugs. Moreover, it highlights the current limitations and obstacles associated with applying these experimental strategies in the clinics.

Radiation-induced H3K9 methylation on E-cadherin promoter mediated by ROS/Snail axis : Role of G9a signaling during lung epithelial-mesenchymal transition

Lung cancer patients who have undergone radiotherapy developed severe complications such as pneumonitis and fibrosis. Upon irradiation, epithelial cells acquire mesenchymal phenotype via a process called epithelial to mesenchymal transition (EMT), which plays a vital role in organ fibrosis. Several mechanisms have been studied on EMT, however, the correlation between radiation-induced EMT and epigenetic changes are not well known. In the present study, we investigated the role of histone methyltransferase G9a on radiation-induced EMT signaling. There was an increase in total global histone methylation level in irradiated epithelial cells. Western blot analysis on irradiated cells showed an increased expression of H3K9me2/3. The pre-treatment of G9a inhibitor enhanced E-cadherin expression and decreased the mesenchymal markers like N-cadherin, vimentin in the radiated group. Surprisingly, radiation-induced ROS generation and pERK1/2 levels were also inhibited by G9a inhibitor BIX01294, which is showing its antioxidant potential. The ChIP-qPCR analysis on the E-cadherin promoter suggested that G9a and Snail might have formed complex to enrich suppressive marker H3K9me2/3. On the whole, our present study suggested that 1] ROS could modify H3K9 methylation via G9a and promote radiation-induced lung EMT in Beas2B and A549 cells 2] E-cadherin promoter enrichment with heterochromatin mark H3K9me2 expression upon irradiation could be modified by regulating G9a methyltransferase.

Molecular Mechanisms of Fuchs and Congenital Hereditary Endothelial Corneal Dystrophies

The cornea, the eye's outermost layer, protects the eye from the environment. The cornea's innermost layer is an endothelium separating the stromal layer from the aqueous humor. A central role of the endothelium is to maintain stromal hydration state. Defects in maintaining this hydration can impair corneal clarity and thus visual acuity. Two endothelial corneal dystrophies, Fuchs Endothelial Corneal Dystrophy (FECD) and Congenital Hereditary Endothelial Dystrophy (CHED), are blinding corneal diseases with varied clinical presentation in patients across different age demographics. Recessive CHED with an early onset (typically age: 0-3 years) and dominantly inherited FECD with a late onset (age: 40-50 years) have similar phenotypes, although caused by defects in several different genes. A range of molecular mechanisms have been proposed to explain FECD and CHED pathology given the involvement of multiple causative genes. This critical review provides insight into the proposed molecular mechanisms underlying FECD and CHED pathology along with common pathways that may explain the link between the defective gene products and provide a new perspective to view these genetic blinding diseases.