Epithelial-mesenchymal transition in development and cancer: role of phosphatidylinositol 3' kinase/AKT pathways

Targeting epithelial-mesenchymal transition signaling pathways with Dietary Phytocompounds and repurposed drug combinations for overcoming drug resistance in various cancers

The epithelial-to-mesenchymal transition (EMT) is a crucial step in metastasis formation. It enhances the ability of cancer cells' to self-renew and initiate tumors, while also increasing resistance to apoptosis and chemotherapy. Among the signaling pathways a few signaling pathways such as Notch, TGF-beta, and Wnt-beta catenin are critically involved in the epithelial-to-mesenchymal transition (EMT) acquisition. Therefore, regulating EMT is a key strategy for controlling malignant cell behavior. This is done by interconnecting other signaling pathways in many cancer types. Although there is extensive preclinical evidence regarding EMT's function in the development of cancer, there is still a deficiency in clinical translation at the therapeutic level. Thus, there is a need for medications that are both highly effective and with low cytotoxic for modulating EMT transitions at ground level. Thus, this led to the study of the evaluation and efficiency of phytochemicals found in dietary sources of fruits and vegetables and also the combination of small molecular repurposed drugs that can enhance the effectiveness of traditional cancer treatments. This review summarises major EMT-associated pathways and their cross talks with their mechanistic insights and the role of different dietary phytochemicals (curcumin, ginger, fennel, black pepper, and clove) and their natural analogs and also repurposed drugs (metformin, statin, chloroquine, and vitamin D) which are commonly used in regulating EMT in various preclinical studies. This review also investigates the concept of low-toxicity and broad spectrum ("The Halifax Project") approach which can help for site targeting of several key pathways and their mechanism. We also discuss the mechanisms of action, models for our dietary phytochemicals, and repurposed drugs and their combinations used to identify potential anti-EMT activities. Additionally, we also analyzed existing literature and proposed new directions for accelerating the discovery of novel drug candidates that are safe to administer.

Sotorasib resistance triggers epithelial-mesenchymal transition and activates AKT and P38-mediated signaling

Background

The molecular non-genetic changes of resistance to sotorasib are currently uncertain. The aim of this study was to generate a sotorasib-resistant cell line via selective pressure and systematically examine the molecular and phenotypic alterations caused by resistance.

Methods

Mutant NCI-H358 (KRASG12C) were exposed to incremental doses (2-512 nM) of sotorasib. Then, resistant clones were separated by single-cell sorting. Proliferation was analyzed in real-time by xCELLigence; protein profiles were quantified by protein arrays; and mRNA expression profile was measured using the PanCancer Pathways panel by NanoString. In silico analyses were conducted from a database comprising patient-derived xenograft (PDX) models and cell lines resistant to sotorasib. AKT and p38. The synergistic effect of combining AKT, p38, and EGFR inhibitors was assessed using the SynergyFinder platform. Additionally, AKT and p38 genes were silenced using esiRNA.

Results

Sotorasib-resistant H358-R cell line displayed markers of the mesenchymal-epithelial transition and loss of cell adhesion. Were identified 30 overexpressed genes in the resistance model, implicating in signaling pathways that leads to AKT activation and heightened protein expression levels of phosphorylated AKT and p38. To identify potential therapeutic strategies for overcoming sotorasib resistance, we investigated the combination of AKT and p38 inhibitors. Notably, combined inhibition of AKT (MK2206) and p38 (adezmapimod) restored sensitivity to sotorasib in resistant cell lines, as did silencing AKT expression.

Conclusion

These findings underscore the importance of adaptive mechanisms in sotorasib resistance in NSCLC cells contributing by EMT activation and demonstrates synergic combination with AKT and p38 inhibitors to restore sotorasib sensitivity in KRASG12C cells.

AXL-TBK1 driven AKT3 activation promotes metastasis

The receptor tyrosine kinase AXL promotes tumor progression, metastasis, and therapy resistance through the induction of epithelial-mesenchymal transition (EMT). Here, we found that activation of AXL resulted in the phosphorylation of TANK-binding kinase 1 (TBK1) and the downstream activation of AKT3 and Snail, a transcription factor critical for EMT. Mechanistically, we showed that TBK1 directly bound to and phosphorylated AKT3 in a manner dependent on the multiprotein complex mTORC1. Upon activation, AKT3 interacted with and promoted the nuclear accumulation of Snail, which led to increased EMT as assessed by marker abundance. In human pancreatic ductal adenocarcinoma tissue, nuclear AKT3 colocalized with Snail and correlated with worse clinical outcomes. Primary mouse pancreatic cancer cells deficient in AKT3 showed reduced metastatic spread in vivo, suggesting selective AKT3 inhibition as a potential therapeutic avenue for targeting EMT in aggressive cancers.

AKT and the Hallmarks of Cancer

Nearly a quarter century ago, Hanahan and Weinberg conceived six unifying principles explaining how normal cells transform into malignant tumors. Their provisional set of biological capabilities acquired during tumor development-cancer hallmarks-would evolve to 14 tenets as knowledge of cancer genomes, molecular mechanisms, and the tumor microenvironment expanded, most recently adding four emerging enabling characteristics: phenotypic plasticity, epigenetic reprogramming, polymorphic microbiomes, and senescent cells. AKT kinases are critical signaling molecules that regulate cellular physiology upon receptor tyrosine kinases and PI3K activation. The complex branching of the AKT signaling network involves several critical downstream nodes that significantly magnify its functional impact, such that nearly every organ system and cell in the body may be affected by AKT activity. Conversely, tumor-intrinsic dysregulation of AKT can have numerous adverse cellular and pathologic ramifications, particularly in oncogenesis, as multiple tumor suppressors and oncogenic proteins regulate AKT signaling. Herein, we review the mounting evidence implicating the AKT pathway in the aggregate of currently recognized hallmarks of cancer underlying the complexities of human malignant diseases. The challenges, recent successes, and likely areas for exciting future advances in targeting this complex pathway are also discussed.

PKC-mediated phosphorylation governs the stability and function of CELF1 as a driver of EMT in breast epithelial cells

Epithelial to mesenchymal transition (EMT) is believed to be a principal factor contributing to cancer metastasis. The post-transcriptional and post-translational mechanisms underlying EMT are comparatively underexplored. We previously demonstrated that the CELF1 RNA binding protein is necessary and sufficient to drive the EMT of breast epithelial cells, and that the relative protein expression of CELF1 in this context was dictated at the post-translational level. Here, we elucidate the mechanism of this regulation. Mass spectrometric analysis of CELF1 isolated from mesenchymal MCF-10A cells identified multiple sites of serine and threonine phosphorylation on the protein, correlating with the increased stability of this protein in this cellular state. Analysis of phosphomimetic and serine/threonine-to-alanine phosphomutant variants of CELF1 revealed that these phosphorylation sites indeed dictate CELF1 stability, ubiquitination state, and function in vitro. Via co-immunoprecipitation and in vitro kinase assays, we identified the protein kinase C alpha and epsilon isozymes as the kinases responsible for CELF1 phosphorylation in a breast cell line. Genetic epistasis experiments confirmed that these PKCs function upstream of CELF1 in this EMT program, and CELF1 phosphorylation impacts tumor metastasis in a xenograft model. This work is the first to formally establish the mechanisms underlying post-translational control of CELF1 expression and function during EMT of breast epithelial cells. Given the broad dysregulation of CELF1 expression in human breast cancer, our results may ultimately provide knowledge that may be leveraged for novel therapeutic interventions in this context.

Cigarette Smoke-Induced Epithelial-to-Mesenchymal Transition: Insights into Cellular Mechanisms and Signaling Pathways

This review delves into the molecular complexities underpinning the epithelial-to-mesenchymal transition (EMT) induced by cigarette smoke (CS) in human bronchial epithelial cells (HBECs). The complex interplay of pathways, including those related to WNT//β-catenin, TGF-β/SMAD, hypoxia, oxidative stress, PI3K/Akt, and NF-κB, plays a central role in mediating this transition. While these findings significantly broaden our understanding of CS-induced EMT, the research reviewed herein leans heavily on 2D cell cultures, highlighting a research gap. Furthermore, the review identifies a stark omission of genetic and epigenetic factors in recent studies. Despite these shortcomings, the findings furnish a consolidated foundation not only for the academic community but also for the broader scientific and industrial sectors, including large tobacco companies and manufacturers of related products, both highlighting areas of current understanding and identifying areas for deeper exploration. The synthesis herein aims to propel further research, hoping to unravel the complexities of the EMT in the context of CS exposure. This review not only expands our understanding of CS-induced EMT but also reveals critical limitations in current methodologies, primarily the reliance on 2D cell cultures, which may not adequately simulate more complex biological interactions. Additionally, it highlights a significant gap in the literature concerning the genetic and epigenetic factors involved in CS-induced EMT, suggesting an urgent need for comprehensive studies that incorporate these types of experiments.

Alterations of the AKT Pathway in Sporadic Human Tumors, Inherited Susceptibility to Cancer, and Overgrowth Syndromes

The AKT kinases are critical signaling molecules that regulate cellular physiology upon the activation of tyrosine kinase receptors and phosphatidylinositol 3-kinases (PI3K). AKT kinases govern many cellular processes considered hallmarks of cancer, including cell proliferation and survival, cell size, tumor invasion, metastasis, and angiogenesis. AKT signaling is regulated by multiple tumor suppressors and oncogenic proteins whose loss or activation, respectively, leads to dysregulation of this pathway, thereby contributing to oncogenesis. Herein, we review the enormous body of literature documenting how the AKT pathway becomes hyperactivated in sporadic human tumors and various hereditary cancer syndromes. We also discuss the role of activating mutations of AKT pathway genes in various chimeric overgrowth disorders, including Proteus syndrome, hypoglycemia with hypertrophy, CLOVES and SOLAMEN syndromes, and hemimegalencephaly.

Lack of basic rationale in epithelial-mesenchymal transition and its related concepts

Epithelial-mesenchymal transition (EMT) is defined as a cellular process during which epithelial cells acquire mesenchymal phenotypes and behavior following the downregulation of epithelial features. EMT and its reversed process, the mesenchymal-epithelial transition (MET), and the special form of EMT, the endothelial-mesenchymal transition (EndMT), have been considered as mainstream concepts and general rules driving developmental and pathological processes, particularly cancer. However, discrepancies and disputes over EMT and EMT research have also grown over time. EMT is defined as transition between two cellular states, but it is unanimously agreed by EMT researchers that (1) neither the epithelial and mesenchymal states nor their regulatory networks have been clearly defined, (2) no EMT markers or factors can represent universally epithelial and mesenchymal states, and thus (3) EMT cannot be assessed on the basis of one or a few EMT markers. In contrast to definition and proposed roles of EMT, loss of epithelial feature does not cause mesenchymal phenotype, and EMT does not contribute to embryonic mesenchyme and neural crest formation, the key developmental events from which the EMT concept was derived. EMT and MET, represented by change in cell shapes or adhesiveness, or symbolized by EMT factors, are biased interpretation of the overall change in cellular property and regulatory networks during development and cancer progression. Moreover, EMT and MET are consequences rather than driving factors of developmental and pathological processes. The true meaning of EMT in some developmental and pathological processes, such as fibrosis, needs re-evaluation. EMT is believed to endow malignant features, such as migration, stemness, etc., to cancer cells. However, the core property of cancer (tumorigenic) cells is neural stemness, and the core EMT factors are components of the regulatory networks of neural stemness. Thus, EMT in cancer progression is misattribution of the roles of neural stemness to the unknown mesenchymal state. Similarly, neural crest EMT is misattribution of intrinsic property of neural crest cells to the unknown mesenchymal state. Lack of basic rationale in EMT and related concepts urges re-evaluation of their significance as general rules for understanding developmental and pathological processes, and re-evaluation of their significance in scientific research.

IL-1β-activated PI3K/AKT and MEK/ERK pathways coordinately promote induction of partial epithelial-mesenchymal transition

Epithelial-mesenchymal transition (EMT) is a cellular process in embryonic development, wound healing, organ fibrosis, and cancer metastasis. Previously, we and others have reported that proinflammatory cytokine interleukin-1β (IL-1β) induces EMT. However, the exact mechanisms, especially the signal transduction pathways, underlying IL-1β-mediated EMT are not yet completely understood. Here, we found that IL-1β stimulation leads to the partial EMT-like phenotype in human lung epithelial A549 cells, including the gain of mesenchymal marker (vimentin) and high migratory potential, without the complete loss of epithelial marker (E-cadherin). IL-1β-mediated partial EMT induction was repressed by PI3K inhibitor LY294002, indicating that the PI3K/AKT pathway plays a significant role in the induction. In addition, ERK1/2 inhibitor FR180204 markedly inhibited the IL-1β-mediated partial EMT induction, demonstrating that the MEK/ERK pathway was also involved in the induction. Furthermore, we found that the activation of the PI3K/AKT and MEK/ERK pathways occurred downstream of the epidermal growth factor receptor (EGFR) pathway and the IL-1 receptor (IL-1R) pathway, respectively. Our findings suggest that the PI3K/AKT and MEK/ERK pathways coordinately promote the IL-1β-mediated partial EMT induction. The inhibition of not one but both pathways is expected yield clinical benefits by preventing partial EMT-related disorders such as organ fibrosis and cancer metastasis.

NRBP1 promotes malignant phenotypes of glioblastoma by regulating PI3K/Akt activation

OBJECTIVES

Glioblastoma (GBM) is the most aggressive of intracranial gliomas. Despite the maximal treatment intervention, the median survival rate is still about 14-16 months. Nuclear receptor-binding protein 1 (NRBP1) has a potential growth-promoting role on biology function of cells. In this study, we investigated whether NRBP1 promotes GBM malignant phenotypes and the potential mechanisms.

METHODS

The correlation between NRBP1 and glioma grade, prognosis in TCGA/CGGA databases and our clinical data were analyzed. Next, we conducted knockout and overexpression of NRBP1 on GBM cells to verify that NRBP1 promoted cell proliferation, invasion, and migration in vitro and in vivo. Finally, we detected the impact of NRBP1 on PI3K/Akt signaling pathway and EMT.

RESULTS

There was a correlation between elevated NRBP1 expression and advanced stage glioma, as well as decreased overall and disease-free survival. The suppression of proliferation, invasion, and migration of tumor cells was observed upon NRBP1 knockout, and in vitro studies also demonstrated the induction of apoptotic cell death. Whereas, its overexpression is associated with high multiplication rate, migration, invasion, and apoptotic escape. GO enrichment and KEGG analysis revealed that NRBP1 regulated differentially expressed gene clusters are involved in PI3K/Akt signaling pathway, as well as EMT mediated by this pathway. Moreover, the effects of NRBP1 knockdown and overexpression on GBM were mitigated by MK-2206 and SC79, both of which respectively function as an inhibitor and an activator of the PI3K/Akt signaling pathway. Similarly, the suppression of NRBP1 led to a decrease in tumor growth, whereas its overexpression promoted tumor growth in a mouse model.

CONCLUSIONS

This study shows that NRBP1 promotes malignant phenotypes in GBM by activating PI3K/Akt pathway. Hence, it can function as both a predictive indicator and a new target for therapies in GBM treatment.

BCAT1 promotes cell proliferation, migration, and invasion via the PI3K-Akt signaling pathway in oral squamous cell carcinoma

OBJECTIVES

To analyze the expression, biological function of branched chain amino-acid transaminase 1 (BCAT1) in oral squamous cell carcinoma (OSCC).

MATERIALS AND METHODS

Real-time PCR and immunohistochemistry were used to analyze the expression of BCAT1 protein in OSCC and normal oral tissues. Based on the clinicopathological information of patients, the relationship between the expression of BCAT1 protein and other clinicopathological factors was analyzed. Real-time PCR and western blot assays were used to analyze the expression of BCAT1 gene and protein in normal human oral keratinocytes (HOK) and human OSCC cells, respectively. After BCAT1 overexpression or knockdown, the proliferation, cell cycle, migration, and invasion of human OSCC cells were analyzed by CCK8, flow cytometry, wound healing, and transwell invasion assays, respectively. After adding the BCAT1 inhibitor EGR240 to OSCC cells, the changes in cell proliferation, migration, and invasion ability in OSCC cells were analyzed. Based on the TCGA database, the involved signal pathway in BCAT1-related and BCAT1-binding genes was obtained for Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis, verified by western blot assays. After inhibiting PI3K, the effect of BCAT1 on the expression of the downstream phosphorylated protein of the PI3K-Akt signaling pathway was analyzed by western blot assays. The relationship between the expression of BCAT1 and EMT-related protein of OSCC cells was also analyzed.

RESULTS

The expression of BCAT1 gene and protein were upregulated in OSCC tissue, which positively correlated with the pathological grade of patients with OSCC. Compared with normal oral keratinocytes, BCAT1 gene and protein were upregulated in OSCC cells. BCAT1 overexpression promoted the proliferation, migration, and invasion of OSCC cells. BCAT1 knockdown or inhibition could reduce the proliferation, migration, and invasion abilities of OSCC cells. The results of bioinformatics analysis and Western bolt showed that BCAT1 could regulate the activation of PI3K-Akt signaling pathway, and promote epithelial-mesenchymal transition (EMT) of OSCC cells.

CONCLUSIONS

BCAT1 could promote the proliferation, migration, and invasion of OSCC cells via PI3K-Akt signaling pathway, which is a potential therapeutic target for OSCC.

TSP50 facilitates breast cancer stem cell-like properties maintenance and epithelial-mesenchymal transition via PI3K p110α mediated activation of AKT signaling pathway

BACKGROUND

Studies have confirmed that epithelial-mesenchymal transition (EMT) and cancer stem cell (CSC)-like properties are conducive to cancer metastasis. In recent years, testes-specific protease 50 (TSP50) has been identified as a prognostic factor and is involved in tumorigenesis regulation. However, the role and molecular mechanisms of TSP50 in EMT and CSC-like properties maintenance remain unclear.

METHODS

The expression and prognostic value of TSP50 in breast cancer were excavated from public databases and explored using bioinformatics analysis. Then the expression of TSP50 and related genes was further validated by quantitative RT-PCR (qRT-PCR), Western blot, and immunohistochemistry (IHC). In order to investigate the function of TSP50 in breast cancer, loss- and gain-of-function experiments were conducted, both in vitro and in vivo. Furthermore, immunofluorescence (IF) and immunoprecipitation (IP) assays were performed to explore the potential molecular mechanisms of TSP50. Finally, the correlation between the expression of TSP50 and related genes in breast cancer tissue microarray and clinicopathological characteristics was analyzed by IHC.

RESULTS

TSP50 was negatively correlated with the prognosis of patients with breast cancer. TSP50 promoted CSC-like traits and EMT in both breast cancer cells and mouse xenograft tumor tissues. Additionally, inhibition of PI3K/AKT partly reversed TSP50-induced activation of CSC-like properties, EMT and tumorigenesis. Mechanistically, TSP50 and PI3K p85α regulatory subunit could competitively interact with the PI3K p110α catalytic subunit to promote p110α enzymatic activity, thereby activating the PI3K/AKT signaling pathway for CSC-like phenotypes maintenance and EMT promotion. Moreover, IHC analysis of human breast cancer specimens revealed that TSP50 expression was positively correlated with p-AKT and ALDH1 protein levels. Notably, breast cancer clinicopathological characteristics, such as patient survival time, tumor size, Ki67, pathologic stage, N stage, estrogen receptor (ER) and progesterone receptor (PR) levels, correlated well with TSP50/p-AKT/ALDH1 expression status.

CONCLUSION

The effects of TSP50 on EMT and CSC-like properties promotion were verified to be dependent on PI3K p110α. Together, our study revealed a novel mechanism by which TSP50 facilitates the progression of breast cancer, which can provide new insights into TSP50-based breast cancer treatment strategies.

TFAP2A downregulation mediates tumor-suppressive effect of miR-8072 in triple-negative breast cancer via inhibiting SNAI1 transcription

BACKGROUND

Triple-negative breast cancer (TNBC) represents a highly aggressive subset of breast malignancies characterized by its challenging clinical management and unfavorable prognosis. While TFAP2A, a member of the AP-2 transcription factor family, has been implicated in maintaining the basal phenotype of breast cancer, its precise regulatory role in TNBC remains undefined.

METHODS

In vitro assessments of TNBC cell growth and migratory potential were conducted using MTS, colony formation, and EdU assays. Quantitative PCR was employed to analyze mRNA expression levels, while Western blot was utilized to evaluate protein expression and phosphorylation status of AKT and ERK. The post-transcriptional regulation of TFAP2A by miR-8072 and the transcriptional activation of SNAI1 by TFAP2A were investigated through luciferase reporter assays. A xenograft mouse model was employed to assess the in vivo growth capacity of TNBC cells.

RESULTS

Selective silencing of TFAP2A significantly impeded the proliferation and migration of TNBC cells, with elevated TFAP2A expression observed in breast cancer tissues. Notably, TNBC patients exhibiting heightened TFAP2A levels experienced abbreviated overall survival. Mechanistically, TFAP2A was identified as a transcriptional activator of SNAI1, a crucial regulator of epithelial-mesenchymal transition (EMT) and cellular proliferation, thereby augmenting the oncogenic properties of TFAP2A in TNBC. Moreover, miR-8072 was unveiled as a negative regulator of TFAP2A, exerting potent inhibitory effects on TNBC cell growth and migration. Importantly, the tumor-suppressive actions mediated by the miR-8072/TFAP2A axis were intricately associated with the attenuation of AKT/ERK signaling cascades and the blockade of EMT processes.

CONCLUSIONS

Our findings unravel the role and underlying molecular mechanism of TFAP2A in driving tumorigenesis of TNBC. Targeting the TFAP2A/SNAI1 pathway and utilizing miR-8072 as a suppressor represent promising therapeutic strategies for treating TNBC.

MicroRNAs as the critical regulators of epithelial mesenchymal transition in pancreatic tumor cells

Pancreatic cancer (PC), as one of the main endocrine and digestive systems malignancies has the highest cancer related mortality in the world. Lack of the evident clinical symptoms and appropriate diagnostic markers in the early stages of tumor progression are the main reasons of the high mortality rate among PC patients. Therefore, it is necessary to investigate the molecular pathways involved in the PC progression, in order to introduce novel early diagnostic methods. Epithelial mesenchymal transition (EMT) is a critical cellular process associated with pancreatic tumor cells invasion and distant metastasis. MicroRNAs (miRNAs) are also important regulators of EMT process. In the present review, we discussed the role of miRNAs in regulation of EMT process during PC progression. It has been reported that the miRNAs mainly regulate the EMT process in pancreatic tumor cells through the regulation of EMT-specific transcription factors and several signaling pathways such as WNT, NOTCH, TGF-β, JAK/STAT, and PI3K/AKT. Considering the high stability of miRNAs in body fluids and their role in regulation of EMT process, they can be introduced as the non-invasive diagnostic markers in the early stages of malignant pancreatic tumors. This review paves the way to introduce a non-invasive EMT based panel marker for the early tumor detection among PC patients.

A dynamic model of inorganic arsenic-induced carcinogenesis reveals an epigenetic mechanism for epithelial-mesenchymal plasticity

Inorganic arsenic (iAs) causes cancer by initiating dynamic transitions between epithelial and mesenchymal cell phenotypes. These transitions transform normal cells into cancerous cells, and cancerous cells into metastatic cells. Most in vitro models assume that transitions between states are binary and complete, and do not consider the possibility that intermediate, stable cellular states might exist. In this paper, we describe a new, two-hit in vitro model of iAs-induced carcinogenesis that extends to 28 weeks of iAs exposure. Through week 17, the model faithfully recapitulates known and expected phenotypic, genetic, and epigenetic characteristics of iAs-induced carcinogenesis. By 28 weeks, however, exposed cells exhibit stable, intermediate phenotypes and epigenetic properties, and key transcription factor promoters (SNAI1, ZEB1) enter an epigenetically poised or bivalent state. These data suggest that key epigenetic transitions and cellular states exist during iAs-induced epithelial-to-mesenchymal transition (EMT), and that it is important for our in vitro models to encapsulate all aspects of EMT and the mesenchymal-to-epithelial transition (MET). In so doing, and by understanding the epigenetic systems controlling these transitions, we might find new, unexpected opportunities for developing targeted, cell state-specific therapeutics.

STK214947, a novel indole alkaloids, inhibits HeLa and SK-HEP-1 cells survival and EMT process by blocking the Notch3 and Akt signals

Apoptosis and epithelial-to-mesenchymal transition (EMT) are closely associated with tumor survival and metastasis. These are the basic events in tumor occurrence and progression. STK214947 is an indole alkaloid with a skeleton that is similar to that of indirubin. Indole alkaloids have attracted considerable attention because of their antitumor activity. However, the relationship between STK214947 and these basic events remains unknown. In this study, the effects of STK214947 on inducing apoptosis and reversing the EMT process in tumor cells were confirmed. Mild concentrations of STK214947 inhibited tumor cell migration by reversing EMT and significantly regulated the expression of EMT-related proteins, including Notch3, E-cadherin, N-cadherin and vimentin. In addition, STK214947 in high concentration could induce apoptosis by down-regulating Notch3, p-Akt/Akt, and NF-κB, and upregulating Caspase 3. These findings support the further development of STK214947 as a potential antitumor small molecule that targets Notch3 and Akt signal transduction in cancer.

Integrative methylome and transcriptome analysis reveals epigenetic regulation of Fusobacterium nucleatum in laryngeal cancer

The aetiological mechanisms of Fusobacterium nucleatum in laryngeal cancer remain unclear. This study aimed to reveal the epigenetic signature induced by F. nucleatum in laryngeal squamous cell carcinoma (LSCC). Combined analysis of methylome and transcriptome data was performed to address the functional role of F. nucleatum in laryngeal cancer. Twenty-nine differentially expressed methylation-driven genes were identified by mapping the methylation levels of significant differential methylation sites to the expression levels of related genes. The combined analysis revealed that F. nucleatum promoted Janus kinase 3 (JAK3) gene expression in LSCC. Further validation found decreased methylation and elevated expression of JAK3 in the F. nucleatum-treated LSCC cell group; F. nucleatum abundance and JAK3 gene expression had a positive correlation in tumour tissues. This analysis provides a novel understanding of the impact of F. nucleatum in the methylome and transcriptome of laryngeal cancer. Identification of these epigenetic regulatory mechanisms opens up new avenues for mechanistic studies to explore novel therapeutic strategies.

Cancer cell plasticity: from cellular, molecular, and genetic mechanisms to tumor heterogeneity and drug resistance

Cancer is a complex disease displaying a variety of cell states and phenotypes. This diversity, known as cancer cell plasticity, confers cancer cells the ability to change in response to their environment, leading to increased tumor diversity and drug resistance. This review explores the intricate landscape of cancer cell plasticity, offering a deep dive into the cellular, molecular, and genetic mechanisms that underlie this phenomenon. Cancer cell plasticity is intertwined with processes such as epithelial-mesenchymal transition and the acquisition of stem cell-like features. These processes are pivotal in the development and progression of tumors, contributing to the multifaceted nature of cancer and the challenges associated with its treatment. Despite significant advancements in targeted therapies, cancer cell adaptability and subsequent therapy-induced resistance remain persistent obstacles in achieving consistent, successful cancer treatment outcomes. Our review delves into the array of mechanisms cancer cells exploit to maintain plasticity, including epigenetic modifications, alterations in signaling pathways, and environmental interactions. We discuss strategies to counteract cancer cell plasticity, such as targeting specific cellular pathways and employing combination therapies. These strategies promise to enhance the efficacy of cancer treatments and mitigate therapy resistance. In conclusion, this review offers a holistic, detailed exploration of cancer cell plasticity, aiming to bolster the understanding and approach toward tackling the challenges posed by tumor heterogeneity and drug resistance. As articulated in this review, the delineation of cellular, molecular, and genetic mechanisms underlying tumor heterogeneity and drug resistance seeks to contribute substantially to the progress in cancer therapeutics and the advancement of precision medicine, ultimately enhancing the prospects for effective cancer treatment and patient outcomes.

K-Ras(V12) differentially affects the three Akt isoforms in lung and pancreatic carcinoma cells and upregulates E-cadherin and NCAM via Akt3

K-Ras is the most frequently mutated Ras variant in pancreatic, colon and non-small cell lung adenocarcinoma. Activating mutations in K-Ras result in increased amounts of active Ras-GTP and subsequently a hyperactivation of effector proteins and downstream signaling pathways. Here, we demonstrate that oncogenic K-Ras(V12) regulates tumor cell migration by activating the phosphatidylinositol 3-kinases (PI3-K)/Akt pathway and induces the expression of E-cadherin and neural cell adhesion molecule (NCAM) by upregulation of Akt3. In vitro interaction and co-precipitation assays identified PI3-Kα as a bona fide effector of active K-Ras4B but not of H-Ras or N-Ras, resulting in enhanced Akt phosphorylation. Moreover, K-Ras(V12)-induced PI3-K/Akt activation enhanced migration in all analyzed cell lines. Interestingly, Western blot analyses with Akt isoform-specific antibodies as well as qPCR studies revealed, that the amount and the activity of Akt3 was markedly increased whereas the amount of Akt1 and Akt2 was downregulated in EGFP-K-Ras(V12)-expressing cell clones. To investigate the functional role of each Akt isoform and a possible crosstalk of the isoforms in more detail, each isoform was stably depleted in PANC-1 pancreatic and H23 lung carcinoma cells. Akt3, the least expressed Akt isoform in most cell lines, is especially upregulated and active in Akt2-depleted cells. Since expression of EGFP-K-Ras(V12) reduced E-cadherin-mediated cell-cell adhesion by induction of polysialylated NCAM, Akt3 was analyzed as regulator of E-cadherin and NCAM. Western blot analyses revealed pronounced reduction of E-cadherin and NCAM in the Akt3-kd cells, whereas Akt1 and Akt2 depletion upregulated E-cadherin, especially in H23 lung carcinoma cells. In summary, we identified oncogenic K-Ras4B as a key regulator of PI3-Kα-Akt signaling and Akt3 as a crucial regulator of K-Ras4B-induced modulation of E-cadherin and NCAM expression and localization.

ADAMTS18 deficiency associates extracellular matrix dysfunction with a higher risk of HER2-positive mammary tumorigenesis and metastasis

BACKGROUND

Human epidermal growth factor receptor 2 (HER2)-positive breast cancer accounts for about 20% of all breast cancer cases and is correlated with a high relapse rate and poor prognosis. ADAMTS18 is proposed as an important functional tumor suppressor gene involved in multiple malignancies, including breast cancer. It functions as an extracellular matrix (ECM) modifier. However, it remains unclear whether ADAMTS18 affects mammary tumorigenesis and malignant progression through its essential ECM regulatory function.

METHODS

To elucidate the role of ADAMTS18 in HER2-positive mammary tumorigenesis and metastasis in vivo, we compared the incidence of mammary tumor and metastasis between Adamts18-knockout (MMTV)-Her2/ErbB2/Neu+ transgenic mice (i.e., Her2t/w/Adamts18-/-) and Adamts18-wildtype (MMTV)-Her2/ErbB2/Neu+ transgenic mice (i.e., Her2t/w/Adamts18+/+). The underlying mechanisms by which ADAMTS18 regulates HER2-positive tumorigenesis and metastasis were investigated by pathology, cell culture, Western blot and immunochemistry.

RESULTS

Adamts18 mRNA is mainly expressed in myoepithelial cells of the mammary duct. ADAMTS18 deficiency leads to a significantly increased incidence of mammary tumors and metastasis, as well as mammary hyperplasia in mice, over 30 months of observation. The proliferation, migration and invasion capacities of primary Her2t/w/Adamts18-/- mammary tumor cells are significantly higher than those of primary Her2t/w/Adamts18+/+ mammary tumor cells in vitro. At 30 months of age, the expression levels of laminin (LNα5), fibronectin (FN) and type I collagen (ColI) in the mammary glands of Her2t/w/Adamts18-/- mice are significantly increased, and the activities of integrin-mediated PI3K/AKT, ERK and JNK signaling pathways are enhanced.

CONCLUSIONS

ADAMTS18 deficiency leads to alterations in mammary ECM components (e.g., LNα5, FN, ColI), which are associated with a higher risk of HER2-positive mammary tumorigenesis and metastasis.

Patterns of Gene Expression Profiles Associated with Colorectal Cancer in Colorectal Mucosa by Using Machine Learning Methods

BACKGROUND

Colorectal cancer (CRC) has a very high incidence and lethality rate and is one of the most dangerous cancer types. Timely diagnosis can effectively reduce the incidence of colorectal cancer. Changes in para-cancerous tissues may serve as an early signal for tumorigenesis. Comparison of the differences in gene expression between para-cancerous and normal mucosa can help in the diagnosis of CRC and understanding the mechanisms of development.

OBJECTIVES

This study aimed to identify specific genes at the level of gene expression, which are expressed in normal mucosa and may be predictive of CRC risk.

METHODS

A machine learning approach was used to analyze transcriptomic data in 459 samples of normal colonic mucosal tissue from 322 CRC cases and 137 non-CRC, in which each sample contained 28,706 gene expression levels. The genes were ranked using four ranking methods based on importance estimation (LASSO, LightGBM, MCFS, and mRMR) and four classification algorithms (decision tree [DT], K-nearest neighbor [KNN], random forest [RF], and support vector machine [SVM]) were combined with incremental feature selection [IFS] methods to construct a prediction model with excellent performance.

RESULT

The top-ranked genes, namely, HOXD12, CDH1, and S100A12, were associated with tumorigenesis based on previous studies.

CONCLUSION

This study summarized four sets of quantitative classification rules based on the DT algorithm, providing clues for understanding the microenvironmental changes caused by CRC. According to the rules, the effect of CRC on normal mucosa can be determined.

Prostate transmembrane androgen inducible protein 1 (PMEPA1): regulation and clinical implications

Prostate transmembrane androgen inducible protein 1 (PMEPA1) can promote or inhibit prostate cancer cell growth based on the cancer cell response to the androgen receptor (AR). Further, it can be upregulated by transforming growth factor (TGF), which downregulates transforming growth factor-β (TGF-β) signaling by interfering with R-Smad phosphorylation to facilitate TGF-β receptor degradation. Studies have indicated the increased expression of PMEPA1 in some solid tumors and its functioning as a regulator of multiple signaling pathways. This review highlights the multiple potential signaling pathways associated with PMEPA1 and the role of the PMEPA1 gene in regulating prognosis, including transcriptional regulation and epithelial mesenchymal transition (EMT). Moreover, the relevant implications in and outside tumors, for example, as a biomarker and its potential functions in lysosomes have also been discussed.

Role of Akt/Protein Kinase B in Cancer Metastasis

Metastasis is a critical step in the process of carcinogenesis and a vast majority of cancer-related mortalities result from metastatic disease that is resistant to current therapies. Cell migration and invasion are the first steps of the metastasis process, which mainly occurs by two important biological mechanisms, i.e., cytoskeletal remodelling and epithelial to mesenchymal transition (EMT). Akt (also known as protein kinase B) is a central signalling molecule of the PI3K-Akt signalling pathway. Aberrant activation of this pathway has been identified in a wide range of cancers. Several studies have revealed that Akt actively engages with the migratory process in motile cells, including metastatic cancer cells. The downstream signalling mechanism of Akt in cell migration depends upon the tumour type, sites, and intracellular localisation of activated Akt. In this review, we focus on the role of Akt in the regulation of two events that control cell migration and invasion in various cancers including head and neck squamous cell carcinoma (HNSCC) and the status of PI3K-Akt pathway inhibitors in clinical trials in metastatic cancers.

Downregulation of EZH2 inhibits epithelial-mesenchymal transition in enzalutamide-resistant prostate cancer

BACKGROUND

Androgen signaling inhibitors (ASI) have been approved for treatment of metastatic castration-resistant prostate cancer (mCRPC). However, the limited success of ASI in clinic justifies an urgent need to identify new targets and develop novel approaches for treatment. EZH2 significantly increases in prostate cancer (PCa). Little is understood, however, regarding the roles of EZH2 in Enzalutamide-resistant (EnzR) mCRPC.

METHODS

We firstly investigated the levels of EZH2 and the altered pathways in public database which was comprised with primary and metastatic PCa patient tumors. To elucidate the roles of EZH2 in mCRPC, we manipulated EZH2 in EnzR PCa cell lines to examine epithelial-mesenchymal transition (EMT). To dissect the underlying mechanisms, we measured the transcription levels of EMT-associated transcription factors (TFs).

RESULTS

We found that EZH2 was highly expressed in mCRPC than that of primary PCa tumors and that EnzR PCa cells gained more EMT characteristics than those of enzalutamide-sensitive counterparts. Further, loss of EZH2-induced inhibition of EMT is independent of polycomb repressive complex 2 (PRC2). Mechanistically, downregulation of EZH2 inhibits transcription of EMT-associated TFs by repressing formation of H3K4me3 to the promotor regions of the TFs.

CONCLUSION

We identified the novel roles of EZH2 in EnzR mCRPC. EnzR PCa gains more EMT properties than that of enzalutamide-sensitive PCa. Loss of EZH2-assocaited inhibition of EMT is PRC2 independent. Downregulation of EZH2 suppresses EMT by impairing formation of H3K4me3 at the promotor regions, thus repressing expression of EMT-associated TFs.

IL-17A functions and the therapeutic use of IL-17A and IL-17RA targeted antibodies for cancer treatment

Interleukin 17A (IL-17A) is a major member of the IL-17 cytokine family and is produced mainly by T helper 17 (Th17) cells. Other cells such as CD8+ T cells, γδ T cells, natural killer T cells and innate lymphoid-like cells can also produce IL-17A. In healthy individuals, IL-17A has a host-protective capacity, but excessive elevation of IL-17A is associated with the development of autoimmune diseases and cancer. Monoclonal antibodies (mAbs) targeting IL-17A (e.g., ixekizumab and secukinumab) or IL-17A receptor (IL-17RA) (e.g., brodalumab) would be investigated as potential treatments for these diseases. Currently, the application of IL-17A-targeted drugs in autoimmune diseases will provide new ideas for the treatment of tumors, and its combined application with immune checkpoint inhibitors has become a research hotspot. This article reviews the mechanism of action of IL-17A and the application of anti-IL-17A antibodies, focusing on the research progress on the mechanism of action and therapeutic blockade of IL-17A in various tumors such as colorectal cancer (CRC), lung cancer, gastric cancer and breast cancer. Moreover, we also include the results of therapeutic blockade in the field of cancer as well as recent advances in the regulation of IL-17A signaling.

Doxorubicin and other anthracyclines in cancers: Activity, chemoresistance and its overcoming

Anthracyclines have been important and effective treatments against a number of cancers since their discovery. However, their use in therapy has been complicated by severe side effects and toxicity that occur during or after treatment, including cardiotoxicity. The mode of action of anthracyclines is complex, with several mechanisms proposed. It is possible that their high toxicity is due to the large set of processes involved in anthracycline action. The development of resistance is a major barrier to successful treatment when using anthracyclines. This resistance is based on a series of mechanisms that have been studied and addressed in recent years. This work provides an overview of the anthracyclines used in cancer therapy. It discusses their mechanisms of activity, toxicity, and chemoresistance, as well as the approaches used to improve their activity, decrease their toxicity, and overcome resistance.

Transcription factors TP63 facilitates malignant progression of thyroid cancer by upregulating KRT17 expression and inducing epithelial-mesenchymal transition

Thyroid cancer (TC) is a relatively prevalent endocrine tumor among women, the incidence of which is rapidly rising. In this present study, we aimed to provide new therapeutic targets from the aspect of transcription factor-target gene interaction. TP63 and KRT17 were both highly expressed in TC tissues and cells. The results of ChIP and dual-luciferase assays confirmed TP63 to bind the KRT17 promoter. Cell function assays revealed that knockdown of TP63 could repress TC cell progression. Furthermore, the rescue assay verified that TP63 could facilitate KRT17 expression to activate the AKT signaling pathway, which in turn stimulated TC cell invasion and migration, and induced EMT. All these results verified that TP63 facilitates TC malignant progression by promoting KRT17 expression and inducing EMT.

Lysyl oxidase like-2 in fibrosis and cardiovascular disease

Fibrosis is an important and essential reparative response to injury that, if left uncontrolled, results in the excessive synthesis, deposition, remodeling, and stiffening of the extracellular matrix, which is deleterious to organ function. Thus, the sustained activation of enzymes that catalyze matrix remodeling and cross linking is a fundamental step in the pathology of fibrotic diseases. Recent studies have implicated the amine oxidase lysyl oxidase like-2 (LOXL2) in this process and established significantly elevated expression of LOXL2 as a key component of profibrotic conditions in several organ systems. Understanding the relationship between LOXL2 and fibrosis as well as the mechanisms behind these relationships can offer significant insights for developing novel therapies. Here, we summarize the key findings that demonstrate the link between LOXL2 and fibrosis and inflammation, examine current therapeutics targeting LOXL2 for the treatment of fibrosis, and discuss future directions for experiments and biomedical engineering.

Effects of a combination of cannabidiol and delta-9-tetrahydrocannabinol on key biological functions of HTR-8/SVneo extravillous trophoblast cells

In recent years, cannabis use has increased among pregnant women. In addition, the phytocannabinoids cannabidiol (CBD) and delta-9-tetrahydrocannabinol (THC) alone or in combination are being used for therapeutical applications. THC and CBD are able to cross the placenta and a lot remains unknown concerning their impact on angiogenesis and extravillous trophoblasts' (EVTs) migration and invasion, which are essential processes for placentation. Thus, in this study, the HTR-8/SVneo cell line was employed to evaluate the effects of CBD, THC and of their combination (1:1, 2 µM). Cannabinoids affected epithelial-mesenchymal transition, as showed by increased expression of the epithelial protein marker E-cadherin for CBD and CBD plus THC treatments, and decrease of mesenchymal intermediate filament vimentin for all treatments. The gene expression of the metalloproteinases MMP2 and MMP9, and of their inhibitors TIMP1 and TIMP2 was increased, except the latter for THC treatment. Moreover, CBD reduced cell migration and invasion, an effect that was enhanced by its combination with THC. CBD with or without THC also upregulated the gene expression of PGF, while the anti-angiogenic factor sFLT1 was increased for all treatments. VEGFA and FLT1 were not affected. Alone or combined CBD and THC also decreased tube segments' length. Additionally, ERK1/2 and STAT3 phosphorylation was increased in the CBD and CBD plus THC-treated cells, while THC only activated STAT3. AKT activation was only affected by CBD. This work demonstrates that the exposure to cannabinoid-based products containing CBD and/or THC, may interfere with key processes of EVTs differentiation. Therefore, crucial phases of placental development can be affected, compromising pregnancy success.

Cross-talk between non-ionizing electromagnetic fields and metastasis; EMT and hybrid E/M may explain the anticancer role of EMFs

Recent studies have shown that non-ionizing electromagnetic fields (NIEMFs) in a specific frequency, intensity, and exposure time can have anti-cancer effects on various cancer cells; however, the underlying precise mechanism of action is not transparent. Most cancer deaths are due to metastasis. This important phenomenon plays an inevitable role in different steps of cancer including progression and development. It has different stages including invasion, intravasation, migration, extravasation, and homing. Epithelial-mesenchymal transition (EMT), as well as hybrid E/M state, are biological processes, that involve both natural embryogenesis and tissue regeneration, and abnormal conditions including organ fibrosis or metastasis. In this context, some evidence reveals possible footprints of the important EMT-related pathways which may be affected in different EMFs treatments. In this article, critical EMT molecules and/or pathways which can be potentially affected by EMFs (e.g., VEGFR, ROS, P53, PI3K/AKT, MAPK, Cyclin B1, and NF-кB) are discussed to shed light on the mechanism of EMFs anti-cancer effect.

The mammalian Sterile 20-like kinase 4 (MST4) signaling in tumor progression: Implications for therapy

Cancer is a leading cause of death in humans, with a complex and dynamic nature that makes it challenging to fully comprehend and treat. The Mammalian Sterile 20-Like Kinase 4 (MST4 or STK26) is a serine/threonine-protein kinase that plays a crucial role in cell migration and polarity in both normal and tumor cells via activation of intracellular signaling molecules and pathways. MST4 is involved in tumor cell proliferation, migration and invasion, epithelial-mesenchymal transition (EMT), survival, and cancer metastasis through modulation of downstream signaling pathways including the extracellular signal-regulated kinase (ERK) and protein kinase B (AKT) pathways. Additionally, MST4 interacts with programmed cell death 10 (PDCD10) to promote tumor proliferation and migration. MST4 phosphorylates autophagy related 4B cysteine peptidase (ATG4B) to mediate autophagy signaling, promote tumor cell survival and proliferation, and contribute to treatment resistance. Taken together, MST4 functions as an oncogene and is a promising therapeutic target which deserves further exploration.

Isolation, Characterization, and Anti-Idiopathic Pulmonary Fibrosis Activity of a Fucoidan from Costaria costata

Pulmonary fibrosis is a chronic, progressive, and fatal disease of the interstitial lung. There is currently a lack of efficient therapy to reverse the prognosis of patients. In this study, a fucoidan from Costaria costata was isolated, and its anti-idiopathic fibrosis activity was investigated both in vitro and in vivo. The chemical composition analysis showed that C. costata polysaccharide (CCP) consists of galactose and fucose as the main monosaccharides with a sulfate group content of 18.54%. Further study found that CCP could resist TGF-β1-induced epithelial-mesenchymal transition (EMT) in A549 cells by inhibiting the TGF-β/Smad and PI3K/AKT/mTOR signaling pathways. Moreover, in vivo study found that CCP treatment alleviated bleomycin (BLM)-stimulated fibrosis and inflammation in mice lung tissue. In conclusion, the present study suggests that CCP could protect the lung from fibrosis by relieving the EMT process and inflammation in lung cells.

Design, synthesis, and biological evaluation of 1-styrenyl isoquinoline derivatives for anti-hepatocellular carcinoma activity and effect on mitochondria

In this study, 18 derivatives of 1-styrene-isoquinoline were designed and synthesized from resveratrol and isoquinoline. The IC₅₀ of compound 1c against Huh7 and SK-Hep-1 cells were 2.52 μM and 4.20 μM, respectively. Mice were treated with 650 mg/kg compound 1c, and the survival status of mice was good. Further studies showed that compound 1c could inhibit cell proliferation by arresting the cell cycle in the G2/M phase, induce cell apoptosis, and inhibit cell migration and invasion by regulating epithelial-mesenchymal transition (EMT). It is worth noting that numbers of studies have pointed that resveratrol can trigger mitochondrial apoptosis to induce apoptosis of cancer cells. Therefore, we investigated the mechanism of compound 1c induced apoptosis of Huh7 and SK-Hep-1 cells. The results indicated that compound 1c could regulate the expression of proteins which are related to mitochondrial apoptosis pathway and inhibit the phosphorylation of PI3K/Akt/mTOR signaling pathway. In addition, compound 1c could inhibit the growth of Huh7-xenografts, and perform a tumor inhibitory rate of 41.44% when administered 30 mg/kg once a day. This work provides a potential anti-hepatocellular carcinoma compound that warrants further investigation.

LncRNA PNKY Is Upregulated in Breast Cancer and Promotes Cell Proliferation and EMT in Breast Cancer Cells

Long non-coding RNAs (lncRNAs) are known to be important regulators in different cellular processes and are implicated in various human diseases. Recently, lncRNA PNKY has been found to be involved in pluripotency and differentiation of embryonic and postnatal neural stem cells (NSCs); however, its expression and function in cancer cells is still unclear. In the present study, we observed the expression of PNKY in various cancer tissues, including brain, breast, colorectal, and prostate cancers. In particular, we demonstrated that lncRNA PNKY was significantly upregulated in breast tumors, especially high-grade tumors. Knock down experiments indicated that the suppression of PNKY in breast cancer cells could restrict their proliferation by promoting apoptosis, senescence, and cell cycle disruption. Moreover, the results demonstrated that PNKY may play a crucial role in the cell migration of breast cancer cells. We further found that PNKY may trigger EMT in breast cancer cells by upregulating miR-150 and restricting the expression of Zeb1 and Snail. This study is the first to provide new evidence on the expression and biological function of PNKY in cancer cells and its potential contribution to tumor growth and metastasis.

VIRMA Promotes Nasopharyngeal Carcinoma Tumorigenesis and Metastasis by Upregulation of E2F7 in an m6A-Dependent Manner

The N6-methyladenosine (m6A) modification possesses new and essential roles in tumor initiation and progression by regulating mRNA biology. However, the role of aberrant m6A regulation in nasopharyngeal carcinoma (NPC) remains unclear. Here, through comprehensive analyses of NPC cohorts from the GEO database and our internal cohort, we identified that VIRMA, an m6A writer, is significantly upregulated in NPC and plays an essential role in tumorigenesis and metastasis of NPC, both in vitro and in vivo. High VIRMA expression served as a prognostic biomarker and was associated with poor outcomes in patients with NPC. Mechanistically, VIRMA mediated the m6A methylation of E2F7 3'-UTR, then IGF2BP2 bound and maintained the stability of E2F7 mRNA. An integrative high-throughput sequencing approach revealed that E2F7 drives a unique transcriptome distinct from the classical E2F family in NPC, which functioned as an oncogenic transcriptional activator. E2F7 cooperated with CBFB-recruited RUNX1 in a non-canonical manner to transactivate ITGA2, ITGA5, and NTRK1, strengthening Akt signaling-induced tumor-promoting effect.

Mechanism of epithelial-mesenchymal transition in cancer and its regulation by natural compounds

Epithelial-mesenchymal transition (EMT) is a complex process with a primordial role in cellular transformation whereby an epithelial cell transforms and acquires a mesenchymal phenotype. This transformation plays a pivotal role in tumor progression and self-renewal, and exacerbates resistance to apoptosis and chemotherapy. EMT can be initiated and promoted by deregulated oncogenic signaling pathways, hypoxia, and cells in the tumor microenvironment, resulting in a loss-of-epithelial cell polarity, cell-cell adhesion, and enhanced invasive/migratory properties. Numerous transcriptional regulators, such as Snail, Slug, Twist, and ZEB1/ZEB2 induce EMT through the downregulation of epithelial markers and gain-of-expression of the mesenchymal markers. Additionally, signaling cascades such as Wnt/β-catenin, Notch, Sonic hedgehog, nuclear factor kappa B, receptor tyrosine kinases, PI3K/AKT/mTOR, Hippo, and transforming growth factor-β pathways regulate EMT whereas they are often deregulated in cancers leading to aberrant EMT. Furthermore, noncoding RNAs, tumor-derived exosomes, and epigenetic alterations are also involved in the modulation of EMT. Therefore, the regulation of EMT is a vital strategy to control the aggressive metastatic characteristics of tumor cells. Despite the vast amount of preclinical data on EMT in cancer progression, there is a lack of clinical translation at the therapeutic level. In this review, we have discussed thoroughly the role of the aforementioned transcription factors, noncoding RNAs (microRNAs, long noncoding RNA, circular RNA), signaling pathways, epigenetic modifications, and tumor-derived exosomes in the regulation of EMT in cancers. We have also emphasized the contribution of EMT to drug resistance and possible therapeutic interventions using plant-derived natural products, their semi-synthetic derivatives, and nano-formulations that are described as promising EMT blockers.

STMN2 overexpression promotes cell proliferation and EMT in pancreatic cancer mediated by WNT/β-catenin signaling

STMN2, as a key regulator in microtubule disassembly and dynamics, has recently been shown to participate in cancer development. However, the corresponding role in pancreatic ductal adenocarcinoma (PC), to our knowledge, has not been reported yet. In the current study, we systematically investigate the potential role of STMN2 in the progression of PC in vitro and vivo. Overexpression of STMN2 was prevalently observed in 81 human cases of PC tissues compared with that in the paired adjacent pancreas (54.3% vs 18.5%, P < 0.01), which was positively associated with multiple advanced clinical stages of PC patients (tumor size, T stage, lymph-node metastasis and the poor prognosis). Meanwhile, a close correlation between high STMN2 and cytoplasmic/nuclear β-catenin expression (P = 0.007) was observed in PC tissues and cell lines. STMN2 overexpression induced EMT and cell proliferation in vitro via stimulating EMT-like cellular morphology, cell motility and proliferation, and the change of EMT (Snail1, E-cadherin and Vimentin) and Cyclin D1 signaling. However, XAV939 inhibited STMN2 overexpression-enhanced EMT and proliferation. Conversely, KY19382 reversed STMN2 silencing- inhibited EMT and cell proliferation in vitro. Furthermore, activated STMN2 and β-catenin were co-localized in cytoplasm/nuclear in vitro. β-catenin/TCF-mediated the transcription of STMN2 by the potential binding sites (TTCAAAG). Finally, STMN2 promoted subcutaneous tumor growth following the activation of EMT and Cyclin D1 signaling. STMN2 overexpression promotes the aggressive clinical stage of PC patients and promotes EMT and cell proliferation in vitro and vivo. β-catenin/TCF-mediated the transcription of STMN2.

PLAC8 contributes to the malignant behaviors of cervical cancer cells by activating the SOX4-mediated AKT pathway

Cervical cancer (CC) is the primary cancer-related cause of morbidity and mortality in women. Previous studies have shown that placenta-specific 8 (PLAC8) has different functions in multiple malignancies. This study aimed to explore the function and regulatory mechanism of PLAC8 in CC. Bioinformatics and immunohistochemical analyses demonstrated that PLAC8 was significantly upregulated in CC tissues compared with normal tissues. Gain/loss-of-function experiments showed that siRNA-mediated knockdown of PLAC8 suppressed cell migration and invasion, while PLAC8 overexpression promoted cell motility. Moreover, PLAC8 was revealed to affect the epithelial-mesenchymal transition (EMT) process by upregulating epithelial (E)-cadherin and decreasing the expression of mesenchymal markers of EMT, including vimentin, zinc finger E-box binding homeobox 1 (ZEB1), neural (N)-cadherin, matrix metalloproteinase-9 (MMP-9), and MMP-2 in PLAC8-silenced cells. PLAC8 activated the AKT pathway, as proven by the downregulation of p-AKT_Ser473 and p-AKT_Thr308 expression after PLAC8 knockdown. Furthermore, PLAC8 overexpression upregulated the expression of sex-determining region Y-related high-mobility group box transcription factor 4 (SOX4), which is reported to mediate the activation of the AKT pathway, and SOX4 deficiency reversed the cellular functions caused by PLAC8 overexpression. Overall, the present study indicates that PLAC8 may facilitate CC development by activating the SOX4-mediated AKT pathway, suggesting that PLAC8 may serve as a potential biomarker for CC treatment.

HERPUD1 promotes ovarian cancer cell survival by sustaining autophagy and inhibit apoptosis via PI3K/AKT/mTOR and p38 MAPK signaling pathways

HERPUD1 is an important early marker of endoplasmic reticulum stress (ERS) and is involved in the ubiquitination and degradation of several unfolded proteins. However, its role in tumorigenesis is seldom studied, and its role in ovarian cancer is unclear. Lewis y antigen is a tumor-associated sugar antigen that acts as an 'antenna' on the cell surface to receive signals from both inside and outside the cell. We previously reported that Lewis y can promote ovarian cancer by promoting autophagy and inhibiting apoptosis. In this study, we detect the expression of HERPUD1 and Lewis y antigens in 119 different ovarian cancer tissues, determine their relationship with clinicopathological parameters, analyze the correlation between these two proteins, and explore the related cancer-promoting mechanisms through MTT, flow cytometry, western blotting, and bioinformatics. HERPUD1 is highly expressed in ovarian cancer, especially in the early stage, and the expression of HERPUD1 and Lewis y antigen was positively correlated. After overexpression of Lewis y antigen, the expression level of HERPUD1 increased. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes pathways (KEGG) analysis showed that HERPUD1 and its related genes are enriched in regulating immunity, endoplasmic reticulum stress, ubiquitin-dependent degradation, ERS-induced apoptosis, and other key signaling pathways. We also clarified the HERPUD1 network of kinases, microRNA and transcription factor targets, and the impact of HERPUD1 mutations on prognosis. In addition, HERPUD1 promotes the proliferation of ovarian cancer cells, inhibits apoptosis, affects the cell cycle, promotes the occurrence of autophagy, and inhibits EMT and PI3K/AKT/mTOR and p38MAPK pathways. Overall, HERPUD1, regulated by the expression of tumor-associated protein Lewis y, promotes cell survival in the early stages of tumors, suggesting that HERPUD1 may play an important role in the development of ovarian cancer.

Research progress on the antitumor effects of astragaloside IV

One of the most important and effective components of Astragalus membranaceus is astragaloside IV (AS-IV), which can exert anti-tumor effects through various pathways. For instance, AS-IV exerts an anti-tumor effect by acting at the cellular level, regulating the phenotype switch of tumor-associated macrophages, or inhibiting the development of tumor cells. Furthermore, AS-IV inhibits tumor cell progression by enhancing its sensitivity to antitumor drugs or reversing the drug resistance of tumor cells. This article reviews the different mechanisms of AS-IV inhibition of epithelial-mesenchymal transition (EMT), migration, proliferation, and invasion of tumor cells, inducing apoptosis and improving the sensitivity of anti-tumor drugs. This review summarizes recent progress in the current research into AS-IV anti-tumor effect and provides insight on the next anti-tumor research of AS-IV.

DNA methyltransferase 1 knockdown reverses PTEN and VDR by mediating demethylation of promoter and protects against renal injuries in hepatitis B virus-associated glomerulonephritis

Background

Aberrant DNA methylation patterns, including hypermethylation of key genes that inhibit fibrosis and inflammation, have been described in human kidney diseases. However, the role of DNA methyltransferase 1 (DNMT1) in hepatitis B virus-associated glomerulonephritis (HBV-GN) remains unclear.

Methods

We explored the underlying mechanism by establishing HBV X protein (HBx) overexpressing renal tubular epithelial (HK-2) cells and human podocytes with DNMT1 knockdown. Using RNA-sequencing to determine the downstream targets of DNMT1 and evaluate its levels of promoter methylation. HBV transgenic mice were used to examine the effects of DNMT1 inhibitor on renal in vivo.

Results

DNMT1 was significantly upregulated in the renal tissue of HBV-GN patients, accompanied by injuries of HK-2 cells and podocytes. HBx markedly upregulated DNMT1 and induced epithelial-mesenchymal transition (EMT) and inflammation in HK-2 cells and human podocytes. This increased DNMT1 expression was attenuated after DNMT1 knockdown, accompanied by restored HK-2 cells and podocyte injuries resulting from the activation of PI3K/Akt/mTOR and nuclear factor-kappa B (NF-κB) pathways. Hypermethylation of the phosphatase and tensin homolog (PTEN) promoter and vitamin D receptor (VDR) was induced in HBx-overexpressing HK-2 cells and podocytes, respectively, whereas DNMT1 knockdown effectively corrected these alterations. Furthermore, PTEN and VDR ablation resulted in marked EMT and inflammation induction in HBx-overexpressing HK-2 cells and human podocytes even with DNMT1 knockdown. Downregulation of the PI3K/Akt/mTOR-related pathway attenuated HBx-induced EMT and inflammation in HK-2 cells. Luciferase reporter assay revealed VDR as a direct target of the Snail family transcriptional repressor 1 (SNAI1) in HBx-overexpressing podocytes. DNA methylation inhibitor 5-azacytidine alleviated urinary protein and renal inflammation in HBV transgenic mice via PTEN-PI3K/Akt signaling and VDR signaling axis.

Conclusions

Our study clarifies the potential epigenetic mechanisms underlying HBx-induced renal injuries in HBV-GN and the renoprotective effects of inhibiting DNMT1, which can provide important insights into the development of treatments for HBV-GN.

CYP2E1-dependent upregulation of SIRT7 is response to alcohol mediated metastasis in hepatocellular carcinoma

Long-term alcohol use is a confirmed risk factor of liver cancer tumorigenesis and metastasis. Multiple mechanisms responsible for alcohol related tumorigenesis have been proposed, including toxic reactive metabolite production, oxidative stress and fat accumulation. However, mechanisms underlying alcohol-mediated liver cancer metastasis remain largely unknown. We have previously demonstrated that SIRT7 regulates chemosensitivity by altering a p53-dependent pathway in human HCC. In the current study, we further revealed that SIRT7 is a critical factor in promoting liver cancer metastasis. SIRT7 expression is associated with disease stage and high SIRT7 predicts worse overall and disease-free survival. Overexpression of SIRT7 promotes HCC cell migration and EMT while knockdown of SIRT7 showed opposite effects. Mechanistically, we found that SIRT7 suppresses E-Cadherin expression through FOXO3-dependent promoter binding and H3K18 deacetylation. Knockdown of FOXO3 abolished the suppressive effect of SIRT7 on E-cadherin transcription. More importantly, we identified that alcohol treatment upregulates SIRT7 and suppresses E-cadherin expression via a CYP2E/ROS axis in hepatocytes both in vitro and in vivo. Antioxidant treatment in primary hepatocyte or CYP2E1-/- mice fed with alcohol impaired those effects. Reducing SIRT7 activity completely abolished alcohol-mediated promotion of liver cancer metastasis in vivo. Taken together, our data reveal that SIRT7 is a pivotal regulator of alcohol-mediated HCC metastasis.

Decoding molecular programs in melanoma brain metastases

Melanoma brain metastases (MBM) variably respond to therapeutic interventions; thus determining patient's prognosis. However, the mechanisms that govern therapy response are poorly understood. Here, we use a multi-OMICS approach and targeted sequencing (TargetSeq) to unravel the programs that potentially control the development of progressive intracranial disease. Molecularly, the expression of E-cadherin (Ecad) or NGFR, the BRAF mutation state and level of immune cell infiltration subdivides tumors into proliferative/pigmented and invasive/stem-like/therapy-resistant irrespective of the intracranial location. The analysis of MAPK inhibitor-naive and refractory MBM reveals switching from Ecad-associated into NGFR-associated programs during progression. NGFR-associated programs control cell migration and proliferation via downstream transcription factors such as SOX4. Moreover, global methylome profiling uncovers 46 differentially methylated regions that discriminate BRAF^mut and wildtype MBM. In summary, we propose that the expression of Ecad and NGFR sub- classifies MBM and suggest that the Ecad-to-NGFR phenotype switch is a rate-limiting process which potentially indicates drug-response and intracranial progression states in melanoma patients.

Cell-cell contact-driven EphB1 cis- and trans- signalings regulate cancer stem cells enrichment after chemotherapy

Reactivation of chemotherapy-induced dormant cancer cells is the main cause of relapse and metastasis. The molecular mechanisms underlying remain to be elucidated. In this study, we introduced a cellular model that mimics the process of cisplatin responsiveness in NSCLC patients. We found that during the process of dormancy and reactivation induced by cisplatin, NSCLC cells underwent sequential EMT-MET with enrichment of cancer stem cells. The ATAC-seq combined with motif analysis revealed that OCT4-SOX2-TCF-NANOG motifs were associated with the enrichment of cancer stem cells induced by chemotherapy. Gene expression profiling suggested a dynamic regulatory mechanism during the process of enrichment of cancer stem cells, where Nanog showed upregulation in the dormant state and SOX2 showed upregulation in the reactivated state. Further, we showed that EphB1 and p-EphB1 showed dynamic expression in the process of cancer cell dormancy and reactivation, where the expression profiles of EphB1 and p-EphB1 showed negatively correlated. In the dormant EMT cells which showed disrupted cell-cell contacts, ligand-independent EphB1 promoted entry of lung cancer cells into dormancy through activating p-p38 and downregulating E-cadherin. On the contrary, in the state of MET, in which cell-cell adhesion was recovered, interactions of EphB1 and ligand EphrinB2 in trans promoted the stemness of cancer cells through upregulating Nanog and Sox2. In conclusion, lung cancer stem cells were enriched during the process of cellular response to chemotherapy. EphB1 cis- and trans- signalings function in the dormant and reactivated state of lung cancer cells respectively. It may provide a therapeutic strategy that target the evolution process of cancer cells induced by chemotherapy.

Upregulation of YKL-40 Promotes Metastatic Phenotype and Correlates with Poor Prognosis and Therapy Response in Patients with Colorectal Cancer

YKL-40 is a heparin- and chitin-binding glycoprotein that belongs to the family of glycosyl hydrolases but lacks enzymatic properties. It affects different (patho)physiological processes, including cancer. In different tumors, YKL-40 gene overexpression has been linked to higher cell proliferation, angiogenesis, and vasculogenic mimicry, migration, and invasion. Because, in colorectal cancer (CRC), the serological YKL-40 level may serve as a risk predictor and prognostic biomarker, we investigated the underlying mechanisms by which it may contribute to tumor progression and the clinical significance of its tissue expression in metastatic CRC. We demonstrated that high-YKL-40-expressing HCT116 and Caco2 cells showed increased motility, invasion, and proliferation. YKL-40 upregulation was associated with EMT signaling activation. In the AOM/DSS mouse model, as well as in tumors and sera from CRC patients, elevated YKL-40 levels correlated with high-grade tumors. In retrospective analyses of six independent cohorts of CRC patients, elevated YKL-40 expression correlated with shorter survival in patients with advanced CRC. Strikingly, high YKL-40 tissue levels showed a predictive value for a better response to cetuximab, even in patients with stage IV CRC and mutant KRAS, and worse sensitivity to oxaliplatin. Taken together, our findings establish that tissue YKL-40 overexpression enhances CRC metastatic potential, highlighting this gene as a novel prognostic candidate, a predictive biomarker for therapy response, and an attractive target for future therapy in CRC.

TRPV1 Is a Potential Tumor Suppressor for Its Negative Association with Tumor Proliferation and Positive Association with Antitumor Immune Responses in Pan-Cancer

Background

Although numerous studies have shown that the expression and activation of TRPV1 have an important role in cancer development, a comprehensive exploration of associations between TRPV1 expression and tumor proliferation, microenvironment, and clinical outcomes in pan-cancer remains insufficient.

Methods

From The Cancer Genome Atlas (TCGA) program, we downloaded multiomics data of ten cancer cohorts and investigated the correlations between TRPV1 expression and immune signatures' enrichment, stromal content, genomic features, oncogenic signaling, and clinical features in these cancer cohorts and pan-cancer.

Results

Elevated expression of TRPV1 correlated with better clinical outcomes in pan-cancer and diverse cancer types. In multiple cancer types, TRPV1 expression correlated negatively with the expression of tumor proliferation marker genes (MKI67 and RACGAP1), proliferation scores, cell cycle scores, stemness scores, epithelial-mesenchymal transition scores, oncogenic pathways' enrichment, tumor immunosuppressive signals, intratumor heterogeneity, homologous recombination deficiency, tumor mutation burden, and stromal content. Moreover, TRPV1 expression was downregulated in late-stage versus early-stage tumors. In breast cancer, bladder cancer, and low-grade glioma, TRPV1 expression was more inferior in invasive than in noninvasive subtypes. Pathway analysis showed that the enrichment of cancer-associated pathways correlated inversely with TRPV1 expression levels.

Conclusion

TRPV1 upregulation correlates with decreased tumor proliferation, tumor driver gene expression, genomic instability, and tumor immunosuppressive signals in various cancers. Our results provide new understanding of the role of TRPV1 in both cancer biology and clinical practice.

Hepatoprotective Effects of a Natural Flavanol 3,3'-Diindolylmethane against CCl4-Induced Chronic Liver Injury in Mice and TGFβ1-Induced EMT in Mouse Hepatocytes via Activation of Nrf2 Cascade

Hepatic fibrosis is a form of irregular wound-healing response with acute and chronic injury triggered by the deposition of excessive extracellular matrix. Epithelial-mesenchymal transition (EMT) is a dynamic process that plays a crucial role in the fibrogenic response and pathogenesis of liver fibrosis. In the present study, we postulated a protective role of 3,3'-diindolylmethane (DIM) against TGF-β1 mediated epithelial-mesenchymal transition (EMT) in vitro and carbon tetrachloride (CCl4)-induced liver fibrosis in mice. TGF-β1-induced AML-12 hepatocyte injury was evaluated by monitoring cell morphology, measuring reactive oxygen species (ROS) and mitochondrial membrane potential, and quantifying apoptosis, inflammatory, and EMT-related proteins. Furthermore, CCl4-induced liver fibrosis in mice was evaluated by performing liver function tests, including serum ALT and AST, total bilirubin, and albumin to assess liver injury and by performing H&E and Sirius red staining to determine the degree of liver fibrosis. Immunoblotting was performed to determine the expression levels of inflammation, apoptosis, and Nrf2/HO-1 signaling-related proteins. DIM treatment significantly restored TGF-β1-induced morphological changes, inhibited the expression of mesenchymal markers by activating E-cadherin, decreased mitochondrial membrane potential, reduced ROS intensity, and upregulated levels of Nrf2-responsive antioxidant genes. In the mouse model of CCl4-induced liver fibrosis, DIM remarkably attenuated liver injury and liver fibrosis, as reflected by the reduced ALT and AST parameters with increased serum Alb activity and fewer lesions in H&E staining. It also mitigated the fibrosis area in Sirius red and Masson staining. Taken together, our results suggest a possible molecular mechanism of DIM by suppressing TGF-β1-induced EMT in mouse hepatocytes and CCl4-induced liver fibrosis in mice.

Single-Cell RNA Sequencing Reveals the Role of Epithelial Cell Marker Genes in Predicting the Prognosis of Colorectal Cancer Patients

Single-cell RNA sequencing (scRNA-seq) is increasingly used in studies on gastrointestinal cancers. This study investigated the prognostic value of epithelial cell-associated biomarkers in colorectal cancer (CRC) using scRNA-seq data. We downloaded and analysed scRNA-seq data from four CRC samples from the Gene Expression Omnibus (GEO), and we identified marker genes of malignant epithelial cells (MECs) using CRC transcriptome and clinical data downloaded from The Cancer Genome Atlas (TCGA) and GEO as training and validation cohorts, respectively. In the TCGA training cohort, weighted gene correlation network analysis, univariate Cox proportional hazard model (Cox) analysis, and least absolute shrinkage and selection operator regression analysis were performed on the marker genes of MEC subsets to identify a signature of nine prognostic MEC-related genes (MECRGs) and calculate a risk score based on the signature. CRC patients were divided into high- and low-risk groups according to the median risk score. We found that the MECRG risk score was significantly correlated with the clinical features and overall survival of CRC patients, and that CRC patients in the high-risk group showed a significantly shorter survival time. The univariate and multivariate Cox regression analyses showed that the MECRG risk score can serve as an independent prognostic factor for CRC patients. Gene set enrichment analysis revealed that the MECRG signature genes are involved in fatty acid metabolism, p53 signalling, and other pathways. To increase the clinical application value, we constructed a MECRG nomogram by combining the MECRG risk score with other independent prognostic factors. The validity of the nomogram is based on receiver operating characteristics and calibration curves. The MECRG signature and nomogram models were well validated in the GEO dataset. In conclusion, we established an epithelial cell marker gene-based risk assessment model based on scRNA-seq analysis of CRC samples for predicting the prognosis of CRC patients.

Analysis of the Effect of SNAI Family in Breast Cancer and Immune Cell

SNAI family members are transcriptional repressors that induce epithelial-mesenchymal transition during biological development. SNAIs both have tumor-promoting and tumor-inhibiting effect. There are key regulatory effects on tumor onset and development, and patient prognosis in infiltrations of immune cell and tumor microenvironmental changes. However, the relationships between SNAIs and immune cell infiltration remain unclear. We comprehensively analyzed the roles of SNAIs in cancer. We used Oncomine and TCGA data to analyze pan-cancer SNAI transcript levels. By analyzing UALCAN data, we found correlations between SNAI transcript levels and breast cancer patient characteristics. Kaplan–Meier plotter analysis revealed that SNAI1 and SNAI2 have a bad prognosis, whereas SNAI3 is the opposite. Analysis using the cBio Cancer Genomics Portal revealed alterations in SNAIs in breast cancer subtypes. Gene Ontology analysis and gene set enrichment analysis were used to analyze differentially expressed genes related to SNAI proteins in breast cancer. We used TIMER to analyze the effects of SNAI transcript levels, mutations, methylation levels, and gene copy number in the infiltration of immune cell. Further, we found the relationships between immune cell infiltration, SNAI expression levels, and patient outcomes. To explore how SNAI proteins affect immune cell, we further studied the correlations between immunomodulator expression, chemokine expression, and SNAI expression. The results showed that SNAI protein levels were correlated with the expression of several immunomodulators and chemokines. Through analysis of PharmacoDB data, we identified antitumor drugs related to SNAI family members and analyzed their IC50 effects on various breast cancer cell lines. In summary, our study revealed that SNAI family members regulate different immune cells infiltrations by gene copy number, mutation, methylation, and expression level. SNAI3 and SNIA1/2 have opposite regulatory effects. They all play a key role in tumor development and immune cell infiltration, and can provide a potential target for drug therapy.

Histone deacetylase 3 promotes alveolar epithelial-mesenchymal transition and fibroblast migration under hypoxic conditions

Epithelial–mesenchymal transition (EMT), a process by which epithelial cells undergo a phenotypic conversion that leads to myofibroblast formation, plays a crucial role in the progression of idiopathic pulmonary fibrosis (IPF). Recently, it was revealed that hypoxia promotes alveolar EMT and that histone deacetylases (HDACs) are abnormally overexpressed in the lung tissues of IPF patients. In this study, we showed that HDAC3 regulated alveolar EMT markers via the AKT pathway during hypoxia and that inhibition of HDAC3 expression by small interfering RNA (siRNA) decreased the migration ability and invasiveness of diseased human lung fibroblasts. Furthermore, we found that HDAC3 enhanced the migratory and invasive properties of fibroblasts by positively affecting the EMT process, which in turn was affected by the increased and decreased levels of microRNA (miR)-224 and Forkhead Box A1 (FOXA1), respectively. Lastly, we found this mechanism to be valid in an in vivo system; HDAC3 siRNA administration inhibited bleomycin-induced pulmonary fibrosis in mice. Thus, it is reasonable to suggest that HDAC3 may accelerate pulmonary fibrosis progression under hypoxic conditions by enhancing EMT in alveolar cells through the regulation of miR-224 and FOXA1. This entire process, we believe, offers a novel therapeutic approach for pulmonary fibrosis.

Inhibiting an enzyme that boosts the invasiveness of fibrosis-related cells could prove to be a novel therapeutic strategy for treating idiopathic lung fibrosis. Lung fibrosis progresses via the transition of epithelial cells into myofibroblasts, which are migratory invasive cell types that secrete collagen and deposit excessive extracellular material. Low oxygen conditions (hypoxia) accelerate this transition process. Scientists recently identified a group of histone deacetylases (HDACs) that are significantly overexpressed in the lung tissues of patients with fibrosis. In experiments on mice and human cell lines, Jeong-Woong Park and Se-Hee Kim at Gachon University Gil Medical Center, Incheon, South Korea, and co-workers demonstrated that under hypoxic conditions, HDAC3 increases the cellular transition to myofibroblasts by regulating the expression of a key microRNA and its target gene. Inhibiting HDAC3 suppresses the migration and invasiveness of lung myofibroblasts.