TGF-β and epithelial-to-mesenchymal transitions

Inhibition of proliferation-linked signaling cascades with atractylenolide I reduces myofibroblastic phenotype and renal fibrosis

Renal fibrosis is a frequent axis contributing to the occurrence of end-stage nephropathy. Previously, it has been reported that atractylenolide Ⅰ (ATL-1), a natural compound extracted from Atractylodes macrocephala, has anti-cancer and antioxidant effects. However, the renal anti-fibrotic effects of action remain unclear. In this study, the anti-fibrotic effects of ATL-1 were examined in fibroblasts, tubular epithelial cells (TECs) triggered by TGF-β1 in vitro, and using a unilateral ureteral obstruction (UUO) mouse model in vivo. We found that ATL-1 represses the myofibroblastic phenotype and fibrosis development in UUO kidneys by targeting the fibroblast-myofibroblast differentiation (FMD), as well as epithelial-mesenchymal transition (EMT). The anti-fibrotic effects of ATL-1 were associated with reduced cell growth in the interstitium and tubules, leading to suppression of the proliferation-linked cascades activity consisting of JAK2/STAT3, PI3K/Akt, p38 MAPK, and Wnt/β-catenin pathways. Besides, ATL-1 treatment repressed TGF-β1-triggered FMD and the myofibroblastic phenotype in fibroblasts by antagonizing the activation of proliferation-linked cascades. Likewise, TGF-β1-triggered excessive activation of the proliferation-linked signaling in TECs triggered EMT. The myofibroblastic phenotype was repressed by ATL-1. The anti-fibrotic and anti-proliferative effects of ATL-1 were linked to the inactivation of Smad2/3 signaling, partially reversing FMD, as well as EMT and the repression of the myofibroblastic phenotype. Thus, the inhibition of myofibroblastic phenotype and fibrosis development in vivo and in vitro through proliferation-linked cascades of ATL-1 makes it a prospective therapeutic bio-agent to prevent renal fibrosis.

Cancer risk in systemic sclerosis: identifying risk and managing high-risk patients

Introduction: Systemic sclerosis (SSc) is associated with a heightened cancer risk compared to the general population. Several pathways including immune system upregulation, cumulative inflammation, environmental factors, and genetic predisposition contribute to the development of both cancer and autoimmunity. Areas covered: This paper provides an overview of studies investigating the relationship between SSc and various types of cancer with a special focus on the identification of patients at higher risk for malignancy development. The demographic, serological, clinical, and disease-related characteristics of SSc individuals who are diagnosed with cancer over the course of their disease are discussed to provide a practical guidance for relevant screening strategies. Expert opinion: Several studies have identified subgroups of SSc patients at higher cancer risk based on the immunological profile (anti-RNAPol III positivity), diffuse disease type, and older age at SSc onset. Additionally, a close temporal association between SSc and cancer onset in certain antibody subsets raises the question as to whether more aggressive screening strategies should be considered. Currently, there are no published studies investigating the cost-effectiveness, efficacy, and safety of a targeted cancer-detection program. Screening procedures should at least follow recommendations for the general population with a special focus on patients at higher risk and specific cancer types.

TM4SF1 promotes EMT and cancer stemness via the Wnt/β-catenin/SOX2 pathway in colorectal cancer

BACKGROUND

Transmembrane 4 L six family member 1 (TM4SF1) is upregulated in several epithelial cancers and is closely associated with poor prognosis. However, the role of TM4SF1 and its potential mechanism in colorectal cancer (CRC) remain elusive.

METHODS

We investigated the expression of TM4SF1 in the Oncomine, the Cancer Genome Atlas (TCGA) and Gene Expression Omnibus (GEO) databases and confirmed the results by immunohistochemistry (IHC), qPCR and Western blotting (WB) of CRC tissues. The effect of TM4SF1 on the epithelial-to-mesenchymal transition (EMT) and cancer stemness of CRC cells was investigated by Transwell, wound healing and sphere formation assays. A series of in vitro and in vivo experiments were conducted to reveal the mechanisms by which TM4SF1 modulates EMT and cancer stemness in CRC.

RESULTS

TM4SF1 expression was markedly higher in CRC tissues than in non-tumour tissues and was positively correlated with poor prognosis. Downregulation of TM4SF1 inhibited the migration, invasion and tumour sphere formation of SW480 and LoVo cells. Conversely, TM4SF1 overexpression significantly enhanced the migration, invasion and tumoursphere formation potential of CRC cells, Additionally, TM4SF1 silencing inhibited the EMT mediated by transforming growth factor-β1 (TGF-β1). Mechanistically, gene set enrichment analysis (GSEA) predicted that the Wnt signalling pathway was one of the most impaired pathways in TM4SF1-deficient CRC cells compared to controls. The results were further validated by WB, which revealed that TM4SF1 modulated SOX2 expression in a Wnt/β-catenin activation-dependent manner. Furthermore, we found that knockdown of TM4SF1 suppressed the expression of c-Myc, leading to decreased c-Myc binding to the SOX2 gene promoter. Finally, depletion of TM4SF1 inhibited metastasis and tumour growth in a xenograft mouse model.

CONCLUSION

Our study substantiates a novel mechanism by which TM4SF1 maintains cancer cell stemness and EMT via the Wnt/β-catenin/c-Myc/SOX2 axis during the recurrence and metastasis of CRC.

The Potential Anticancer Activity of Phytoconstituents against Gastric Cancer-A Review on In Vitro, In Vivo, and Clinical Studies

Gastric cancer belongs to the heterogeneous malignancies and, according to the World Health Organization, it is the fifth most commonly diagnosed cancer in men. The aim of this review is to provide an overview on the role of natural products of plant origin in the therapy of gastric cancer and to present the potentially active metabolites which can be used in the natural therapeutical strategies as the support to the conventional treatment. Many of the naturally spread secondary metabolites have been proved to exhibit chemopreventive properties when tested on the cell lines or in vivo. This manuscript aims to discuss the pharmacological significance of both the total extracts and the single isolated metabolites in the stomach cancer prevention and to focus on their mechanisms of action. A wide variety of plant-derived anticancer metabolites from different groups presented in the manuscript that include polyphenols, terpenes, alkaloids, or sulphur-containing compounds, underlines the multidirectional nature of natural products.

Analysis of Melanoma Secretome for Factors That Directly Disrupt the Barrier Integrity of Brain Endothelial Cells

We have recently demonstrated that invasive melanoma cells are capable of disrupting the brain endothelial barrier integrity. This was shown using ECIS biosensor technology, which revealed rapid disruption via the paracellular junctions. In this paper, we demonstrate that melanoma cells secrete factors (e.g., cytokines) that weaken the endothelial barrier integrity. Through proteome profiling, we attempt to identify the barrier-disrupting cytokines. Melanoma conditioned media were collected from three New Zealand melanoma lines. ECIS technology was used to assess if the conditioned media disrupted the endothelial barrier independent of the melanoma cells. The melanoma cell secretome was assessed using cytometric bead array (CBA), Luminex immunoassay and multiplex Proteome Profilers, to detect the expression of secretory proteins, which may facilitate metastasis. Finally, ECIS technology was used to assess the direct effects of secreted proteins identified as candidates from the proteome screens. We show that melanoma-conditioned media significantly disrupted the brain endothelial barrier, however, to a much lesser extent than the cells from which they were collected. Cytokine and proteome profiling of the conditioned media showed evidence of high concentrations of approximately 15 secreted proteins (including osteopontin, IL-8, GDF-15, MIF and VEGF). These 15 secreted proteins were expressed variably across the melanoma lines. Surprisingly, the addition of these individually to the brain endothelial cells did not substantially affect the barrier integrity. ANGPTL-4 and TGFβ were also produced by the melanoma cells. Whilst TGFβ-1 had a pronounced effect on the barrier integrity, surprisingly ANGPTL-4 did not. However, its C-terminal fragment did and within a very similar period to the conditioned media, albeit not to the same extent. Herein we show that melanoma cells produce a wide-range of soluble factors at high concentrations, which most likely favour support or survival of the cancer cells. Most of these, except for TGFβ-1 and the C-terminal fragment of ANGPTL-4, did not have an impact on the integrity of the brain endothelial cells.

ATP6AP2 is Overexpressed in Breast Cancer and Promotes Breast Cancer Progression

Background

Adenosine triphosphatase H+ transporting accessory protein 2 (ATP6AP2), also known as (pro)renin receptor, is implicated in tumorigenesis and the progression of several types of cancer. This study investigated the role of ATP6AP2 in breast cancer.

Methods

UALCAN and ONCOMINE datasets were utilized to compare transcript levels of ATP6AP2 in breast cancer and normal tissues. GOBO datasets were applied to examine ATP6AP2 expression in different breast cancer cell lines. We used the cBioPortal website to explore the gene alterations and copy number alterations of ATP6AP2 in breast cancer. Cell Counting Kit-8 and transwell assays were conducted to evaluate ATP6AP2 function in MCF-7 breast cancer cells. Finally, we used the cBioPortal website to establish the interaction network of ATP6AP2 in breast cancer and performed functional enrichment analysis based on Gene Ontology terms and Kyoto Encyclopedia of Genes and Genomes pathways.

Results

ATP6AP2 was overexpressed in breast cancer tissues and breast cancer cell lines in the UALCAN, ONCOMINE, and GOBO datasets. The major type of ATP6AP2 alteration was mRNA upregulation. Moreover, ATP6AP2 was most highly expressed in luminal type breast cancer. Finally, ATP6AP2 knockdown reduced MCF-7 cell proliferation, invasion and migration. Functional enrichment analysis suggested that ATP6AP2 regulates several cancer-related pathways, especially the Wnt/β-catenin signaling pathway.

Conclusion

Applying multi-dimensional analytical methods, we demonstrate that ATP6AP2 is upregulated in breast cancer and may promote its development and progression.

Transforming Growth Factor β1 Induces Epithelial–mesenchymal Transition by Activating the Jnk–SMAD3 Pathway in Rat Peritoneal Mesothelial Cells

⋄ Background

Peritoneal fibrosis is a serious complication in long-term peritoneal dialysis (PD) patients. Epithelial-mesenchymal transition (EMT) plays an important role in peritoneal fibrosis, and TGFβ1 is the crucial inducer of EMT. Phosphorylation of Smad proteins is required for TGFβ1-induced EMT. It was reported that C-Jun N-terminal kinase (JNK) was involved in the TGFβ1/Smad signaling pathway and might regulate the activation of Smad proteins. However, whether JNK is activated by TGFβ1 in rat peritoneal mesothelial cells (RPMCs) and the role taken by JNK signaling in EMT induced by TGFβ1 remains undetermined. In the present study, we investigated the role of JNK-Smad pathway in EMT induced by TGFβ1 in RPMCs.

⋄ Methods

We harvested RPMCs from the peritoneum of male Sprague-Dawley rats and then cultured the cells in Dulbecco modified Eagle medium / F12 medium with 15% (volume:volume) fetal bovine serum. The cells were pretreated with SP600125, a specific inhibitor of JNK, for 4 hours before incubation with TGFβ1. The protein expression levels of phosphorylated JNK, Smad2, and Smad3 were detected by Western blotting. The messenger RNA levels and protein expression of α-smooth muscle actin (α-SMA), E-cadherin, and collagen I were determined with reverse transcriptase polymerase chain reaction and Western blotting respectively.

⋄ Results

Expression of α-SMA and collagen I were significantly increased and expression of E-cadherin decreased with TGFβ1 in RPMCs. Transforming growth factor β1 can stimulate phosphorylated JNK expression from 5 minutes, with the peak at 10 minutes, and phosphorylated Smad2 and Smad3 expression from 10 minutes, with the peak at 30 minutes. The addition of SP600125, which blocked activation of JNK, effectively inhibited TGFβ1-induced phosphorylation of Smad3, but not Smad2. Also, our results showed that SP600125 effectively suppressed TGFβ1-induced high expression of α-SMA and collagen I, and prevented TGFβ1-induced downregulation of E-cadherin expression in RPMCs.

⋄ Conclusions

This study demonstrated that JNK signaling may play an important role in EMT induced by TGFβ1 in RPMCs through activation of Smad3, suggesting that JNK inhibitor may prove to be a novel therapeutic agent for peritoneal fibrosis.

Toluene diisocyanate-induced inflammation and airway remodeling involves autophagy in human bronchial epithelial cells

Toluene-diisocyanate (TDI) is one of the main causes of occupational asthma. To study the role of autophagy in TDI-induced airway inflammation and airway remodeling in bronchial airway epithelial (16HBE) cells. We treated 16HBE cells with TDI-human serum albumin (TDI-HSA) conjugate to observe reactive oxygen species (ROS) release, autophagy activation, airway inflammation and airway remodeling. 3-Methyladenine (3-MA) and Rapamycin (Rapa) intervention were used to explore the effects of autophagy on inflammatory response and protein expression related to airway remodeling in 16HBE cells treated with TDI-HSA. Experimental results suggested that various concentrations of TDI-HSA (0, 40, 80 and 120 μg/mL) increased the release of ROS and the expression of Nrf2, activated autophagy and increased the expression of AMPK, Beclin-1, LC3 and decreased the expression of p62, promoted the levels of IL-5, IL-6 and IL-8 in 16HBE cells. Results also showed that E-cadherin expression decreased but an increase was observed in α-SMA and MMP-9 in the TDI-HSA group. The treatment of TDI-HSA combined with Rapa aggravated the above reaction whereas the inverse was true for TDI-HSA combined with 3-MA. These results indicated that autophagy is involved in TDI-induced airway inflammation and airway remodeling as a positive regulatory mechanism, inhibiting autophagy can significantly alleviate the TDI-induced inflammatory response and attenuate airway remodeling protein expression in 16HBE cells.

OSR1 phosphorylates the Smad2/3 linker region and induces TGF-β1 autocrine to promote EMT and metastasis in breast cancer

Oxidative stress-responsive kinase 1 (OSR1) plays a critical role in multiple carcinogenic signal pathways, and its overexpression has been found in various types of cancer; however, the pathophysiological role of OSR1 in breast cancer has not been evaluated. This study aims to elaborate on the role of OSR1 in breast cancer metastasis and the specific regulatory mechanism. Our results showed that OSR1 mRNA and protein were upregulated in both human breast cancer samples and cell lines. Moreover, phosphorylated OSR1 (p-OSR1) was an independent poor prognostic indicator in patients with breast cancer. OSR1 upregulation induced epithelial-to-mesenchymal transition (EMT) in normal and malignant mammary epithelial cells with the increasing metastatic capacity. In contrast, deleting OSR1 in aggressive breast cancer cells inhibited these phenotypes. OSR1 is the critical activator for transcription factors of EMT. Mechanistically, we found that OSR1 can directly interact and phosphorylate the linker region of Smad2 at Thr220 and Smad3 at Thr179. Phosphorylated Smad2/3 translocated into the nucleus to enhance transforming growth factor-β1 (TGF-β1) autocrine signalling and increase the transcription of EMT regulators. Importantly, interruption of the OSR1-Smad2/3-TGF-β1 signalling axis elicited a robust anti-EMT and anti-metastatic effect in vitro and in vivo. Taken together, we conclude that OSR1-mediated Smad2/3-TGF-β1 signalling promotes EMT and metastasis representing a promising therapeutic target in breast cancer treatment.

Tight junction protein claudin-1 is downregulated by TGF-β1 via MEK signaling in benign prostatic epithelial cells

BACKGROUND

Benign prostatic hyperplasia (BPH) is arguably the most common disease in aging men. Although the etiology is not well understood, chronic prostatic inflammation is thought to play an important role in BPH initiation and progression. Our recent studies suggest that the prostatic epithelial barrier is compromised in glandular BPH tissues. The proinflammatory cytokine transforming growth factor beta 1 (TGF-β1) impacts tight junction formation, enhances epithelial barrier permeability, and suppresses claudin-1 messenger RNA expression in prostatic epithelial cells. However, the role of claudin-1 in the prostatic epithelial barrier and its regulation by TGF-β1 in prostatic epithelial cells are not clear.

METHODS

The expression of claudin-1 was analyzed in 22 clinical BPH specimens by immunohistochemistry. Human benign prostate epithelial cell lines BPH-1 and BHPrE1 were treated with TGF-β1 and transfected with small interfering RNAs specific to claudin-1. Epithelial monolayer permeability changes in the treated cells were measured using trans-epithelial electrical resistance (TEER). The expression of claudin-1, E-cadherin, N-cadherin, snail, slug, and activation of mitogen-activated proteins kinases (MAPKs) and AKT was assessed following TGF-β1 treatment using Western blot analysis.

RESULTS

Claudin-1 expression was decreased in glandular BPH tissue compared with adjacent normal prostatic tissue in patient specimens. TGF-β1 treatment or claudin-1 knockdown in prostatic epithelial cell lines increased monolayer permeability. TGF-β1 decreased levels of claudin-1 and increased levels of snail and slug as well as increased phosphorylation of the MAPK extracellular signal-regulated kinase-1/2 (ERK-1/2) in both BPH-1 and BHPrE1 cells. Overexpression of snail or slug had no effect on claudin-1 expression. In contrast, PD98059 and U0126, inhibitors of the upstream activator of ERK-1/2 (ie, MEK-1/2) restored claudin-1 expression level as well as the epithelial barrier.

CONCLUSION

Our findings suggest that downregulation of claudin-1 by TGF-β1 acting through the noncanonical MEK-1/2/ERK-1/2 pathway triggers increased prostatic epithelial monolayer permeability in vitro. These findings also suggest that elevated TGF-β1 may contribute to claudin-1 downregulation and compromised epithelial barrier in clinical BPH specimens.

Metaplastic carcinoma of breast: a report of two cases

The pathogenesis of metaplastic breast carcinoma (MBC) is still debatable and it has been hypothesized that MBC develops as a result of transformation of epithelial cells into mesenchymal cells along with formation of a favorable tumor microenvironment. This favorable tumor microenvironment helps the transformed cells to undergo further mutations and clonal expansion. Case 1 was a 42-year old female with a 1-year history of a right breast fungating mass which was histologically confirmed to be matrix-producing type of MBC. Case 2 was a 47-year old female who presented with a recurrent left breast mass. Histologically, the tumor was confirmed to be carcinosarcomatous type of MBC. MBC is a rare, heterogeneous tumor with poor prognosis due to its aggressive behavior. It is more likely to mimic other benign breast conditions, therefore contributing to delay of diagnosis as it was for both of our patients herein presented.

The oncogenic potential of NANOG: An important cancer induction mediator

Cancer stem cells (CSCs) are a unique population in the tumor, but they only comprise 2%-5% of the tumor bulk. Although CSCs share several features with embryonic stem cells, CSCs can give rise to the tumor cells. CSCs overexpress embryonic transcription factor NANOG, which is downregulated in differentiated tissues. This transcription factor confers CSC's stemness, unlimited self-renewal, metastasis, invasiveness, angiogenesis, and drug-resistance with the assistance of WNT, OCT4, SOX2, Hedgehog, BMI-1, and other complexes. NANOG facilitates CSCs development via multiple pathways, like angiogenesis and lessening E-cadherin expression levels, which paves the road for metastasis. Moreover, NANOG represses apoptosis and leads to drug-resistance. This review aims to highlight the pivotal role of NANOG and the pertained pathways in CSCs. Also, this current study intends to demonstrate that targeting NANOG can dimmish the CSCs, sensitize the tumor to chemotherapy, and eradicate the cancer cells.

Cellular and molecular events of inflammation induced transdifferentiation (EMT) and regeneration (MET) in mesenteric mesothelial cells

In this review we summarize the cellular and molecular events of inflammation induced epithelial-to-mesenchymal (EMT) and mesothelial-to-macrophage transition (MET) during regeneration. Since the receptor transmits the environmental stimulus, downregulating or upregulating the process on an epigenetic level, the intracellular localization of receptors (signaling organelles: early endosomes or lysosomal degradation: late endosomes) plays a crucial role in the signaling events regulating inflammation and regeneration. Therefore, we focused on the internalization of the receptors as well as the intracellular compartmentalization of signaling molecules during EMT and MET. The review draws the reader's attention to the plasticity of mesothelial cells and supports the idea that during inflammation an ambient macrophage population might derive from mesothelial cells.

Ophiopogonin D suppresses TGF-β1-mediated metastatic behavior of MDA-MB-231 breast carcinoma cells via regulating ITGB1/FAK/Src/AKT/β-catenin/MMP-9 signaling axis

Ophiopogonin D, a steroidal glycoside extracted from the Traditional Chinese Medicine Ophiopogon japonicus, shows anti-tumor property in several lines of cancers; however, its effect on triple-negative breast cancer (TNBC) has not been investigated. In this study, the anti-metastatic effect of Ophiopogonin D in TNBC cells as well as the underlying mechanism in such process was explored. Ophiopogonin D dose-dependently decreased cell proliferation of MDA-MB-231 cells. Meanwhile, Ophiopogonin D significantly inhibited TGF-β1-induced metastatic behavior of MDA-MB-231 cells, including EMT, anoikis resistance as well as migration and invasion, via suppressing MMP-9 activity. Mechanically, Ophiopogonin D achieved its effect through efficiently abolishing ITGB1 expression, thus reducing the phosphorylation of FAK, Src and AKT, as well as upregulating nuclear β-catenin. ITGB1 overexpression partly recovered Ophiopogonin D's inhibitory effect on metastatic behavior via activating MMP-9. These results demonstrated that Ophiopogonin D could suppress TGF-β1-mediated metastatic behavior of MDA-MB-231 cells by regulating ITGB1/FAK/Src/AKT/β-catenin/MMP-9 signaling axis, which might provide new insight for the control of TNBC metastasis.

A fine-tuned β-catenin regulation during proliferation of corneal endothelial cells revealed using proteomics analysis

Corneal endothelial (CE) dysfunction is the main indication for corneal transplantation, an invasive procedure with several limitations. Developing novel strategies to re-activate CE regenerative capacity is, therefore, of fundamental importance. This goal has proved to be challenging as corneal endothelial cells (CEnC) are blocked in the G0/G1 phase of the cell cycle in vivo and, albeit retaining proliferative capacity in vitro, this is further hindered by endothelial-to-mesenchymal transition. Herein we investigated the mechanisms regulating CEnC proliferation in vitro. Comparing the proteome of non-proliferating (in vivo-G0/G1) and proliferating (in vitro-G2/M) rabbit CEnC (rCEnC), 77 proteins, out of 3,328 identified, were differentially expressed in the two groups (p < 0.005). Literature and Gene Ontology analysis revealed β-catenin and transforming growth factor (TGF-β) pathways to be correlated with the identified proteins. Treatment of rCEnC with a β-catenin activator and inhibitor showed that β-catenin activation was necessary during rCEnC proliferation, but not sufficient for its induction. Furthermore, both pro-proliferative activity of basic fibroblast growth factor and anti-proliferative effects of TGF-β were regulated through β-catenin. Overall, these results provide novel insights into the molecular basis underlying the proliferation process that CEnC re-activate in vitro, consolidating the role of β-catenin and TGF-β.

Pulmonary Fibrosis in COVID-19 Survivors: Predictive Factors and Risk Reduction Strategies

Although pulmonary fibrosis can occur in the absence of a clear-cut inciting agent, and without a clinically clear initial acute inflammatory phase, it is more commonly associated with severe lung injury. This may be due to respiratory infections, chronic granulomatous diseases, medications, and connective tissue disorders. Pulmonary fibrosis is associated with permanent pulmonary architectural distortion and irreversible lung dysfunction. Available clinical, radiographic, and autopsy data has indicated that pulmonary fibrosis is central to severe acute respiratory distress syndrome (SARS) and MERS pathology, and current evidence suggests that pulmonary fibrosis could also complicate infection by SARS-CoV-2. The aim of this review is to explore the current literature on the pathogenesis of lung injury in COVID-19 infection. We evaluate the evidence in support of the putative risk factors for the development of lung fibrosis in the disease and propose risk mitigation strategies. We conclude that, from the available literature, the predictors of pulmonary fibrosis in COVID-19 infection are advanced age, illness severity, length of ICU stay and mechanical ventilation, smoking and chronic alcoholism. With no proven effective targeted therapy against pulmonary fibrosis, risk reduction measures should be directed at limiting the severity of the disease and protecting the lungs from other incidental injuries.

Epithelial-Mesenchymal Transition and Metabolic Switching in Cancer: Lessons From Somatic Cell Reprogramming

Epithelial-mesenchymal transition (EMT) and its critical roles during cancer progression have long been recognized and extensively reviewed. Recent studies on the generation of induced pluripotent stem cells (iPSCs) have established the connections among EMT, energy metabolism, DNA methylation, and histone modification. Since energy metabolism, DNA methylation, and histone modification are important for cancer development and there are common characteristics between cancer cells and stem cells, it is reasonable to identify mechanisms that have been established during both reprogramming and cancer progression. In the current review, we start from a brief review on EMT and related processes during cancer progression, and then switch to the EMT during somatic cell reprogramming. We summarize the connection between EMT and metabolic switch during reprogramming, and further review the involvements of DNA methylation and cell proliferation. The connections between EMT and mesenchymal-epithelial transition (MET) and cellular aspects including DNA methylation, histone modification and energy metabolism may provide potential new targets for cancer diagnosis and treatment.

Resveratrol reduces gentamicin-induced EMT in the kidney via inhibition of reactive oxygen species and involving TGF-β/Smad pathway

AIMS

Gentamicin (GEN) is one of the most valuable aminoglycoside antibiotics utilized against life-threatening bacterial infections. Unfortunately, GEN-induced nephrotoxicity limited its clinical utility. The pathologic process of nephrotoxicity caused by GEN may involve epithelial to mesenchymal transition (EMT). Resveratrol (RES) is a natural compound was revealed to inhibit EMT in kidney. The present work was conducted to explore the potential renoprotective role of RES on GEN-induced EMT. Moreover, the underlying signaling pathway of this inhibition was investigated.

MAIN METHODS

Mice were treated with GEN by intraperitoneal (i.p.) route daily for 15 days to identify EMT onset with regard to GEN-induced nephrotoxicity. To assess the ameliorative role of RES against GEN-induced EMT, RES was i.p. administrated in high and low doses before and concurrently with GEN treatment.

KEY FINDINGS

GEN administration significantly deteriorated kidney functions. In addition, reduced glutathione (GSH) content and catalase (CAT) activity were significantly decreased with a concomitant increase in the content of kidney malondialdehyde (MDA) after GEN treatment. Histological changes and deposition of collagen were extensive in renal corpuscles and tubules. Increased expression of alpha smooth muscle actin (α-SMA), transforming growth factor-β1 (TGF-β1) and phosphorylated (p)-Smad2 were observed after GEN administration, while E-cadherin expression was decreased. On the contrary, pretreatment with both doses of RES reversed the modifications caused by GEN administration.

SIGNIFICANCE

We concluded that EMT contributes to pathogenesis of GEN-induced nephrotoxicity. RES has a protective effect on GEN-induced EMT via suppressing oxidative stress and a possible involvement of TGF-β/Smad signaling pathway.

Nucleosome Assembly Protein 1-Like 3 Enhances Cisplatin Resistance of Ovarian Cancer Cell by Activating Transforming Growth Factor-Beta Pathway

Chemotherapy resistance is one of the main reasons for tumor-related death. In particular, ovarian cancer patients often acquire drug resistance after chemotherapy. In this study, we found that the histone chaperone, nucleosome assembly protein 1-like 3 (NAP1L3), was significantly upregulated in tissues with cisplatin resistance compared with cisplatin-sensitive tissues. Patients with high NAP1L3 levels had poor prognosis, suggesting that NAP1L3 might regulate ovarian cancer resistance. Colony formation and terminal deoxynulceotidyl transferase nick-end-labeling (TUNEL) assays showed cells with high NAP1L3 had high cisplatin resistance, whereas cells with low NAP1L3 had poor cisplatin resistance. NAP1L3 overexpression significantly increased cisplatin resistance, whereas NAP1L3 knockdown significantly reduced cisplatin resistance, suggesting that NAP1L3 promoted cisplatin resistance. Mechanistically, gene set enrichment analysis and luciferase reporter assays showed that NAP1L3 regulated the transforming growth factor-beta (TGF-β) pathway. NAP1L3 overexpression increased the phosphorylation and nuclear translocation of SMAD family member 2 (SMAD2) and SMAD3, confirming that NAP1L3 activated the TGF-β pathway. Therefore, NAP1L3 might represent a novel target to overcome ovarian cancer chemoresistance.

Research Advances in the Mechanisms of Hyperuricemia-Induced Renal Injury

Uric acid is the end product of purine metabolism in humans, and its excessive accumulation leads to hyperuricemia and urate crystal deposition in tissues including joints and kidneys. Hyperuricemia is considered an independent risk factor for cardiovascular and renal diseases. Although the symptoms of hyperuricemia-induced renal injury have long been known, the pathophysiological molecular mechanisms are not completely understood. In this review, we focus on the research advances in the mechanisms of hyperuricemia-caused renal injury, primarily on oxidative stress, endothelial dysfunction, renal fibrosis, and inflammation. Furthermore, we discuss the progress in hyperuricemia management.

TGF-β causes Docetaxel resistance in Prostate Cancer via the induction of Bcl-2 by acetylated KLF5 and Protein Stabilization

Prostate cancer is the second leading cause of cancer-related death in the United States. As a first line treatment for hormone-refractory prostate cancer, docetaxel (DTX) treatment leads to suboptimal effect since almost all patients eventually develop DTX resistance. In this study, we investigated whether and how TGF-β affects DTX resistance of prostate cancer.

Methods: Cytotoxicity of DTX in DU 145 and PC-3 cells was measured by CCK-8 and Matrigel colony formation assays. Resistance to DTX in DU 145 cells was examined in a xenograft tumorigenesis model. A luciferase reporter system was used to determine transcriptional activities. Gene expression was analyzed by RT-qPCR and Western blotting.

Results: We found that KLF5 is indispensable in TGF-β-induced DTX resistance. Moreover, KLF5 acetylation at lysine 369 mediates DTX resistance in vitro and in vivo. We showed that the TGF-β/acetylated KLF5 signaling axis activates Bcl-2 expression transcriptionally. Furthermore, DTX-induced Bcl-2 degradation depends on a proteasome pathway, and TGF-β inhibits DTX-induced Bcl-2 ubiquitination.

Conclusion: Our study demonstrated that the TGF-β-acetylated KLF5-Bcl-2 signaling axis mediates DTX resistance in prostate cancer and blockade of this pathway could provide clinical insights into chemoresistance of prostate cancer.

IL-6 Deficiency Exacerbates Allergic Asthma and Abrogates the Protective Effect of Allergic Inflammation against Streptococcus pneumoniae Pathogenesis

Allergic asthma (AA) is characterized as a Th2-biased airway inflammation that can develop lung inflammation and remodeling of the respiratory tract. Streptococcus pneumoniae is a major respiratory pathogen, causing noninvasive (otitis media and pneumonia) and invasive diseases (sepsis) in humans. We sought to determine the role of IL-6 in the regulation of lung inflammation in murine AA caused by Aspergillus fumigatus as well as its consequence on the regulation of airway barrier integrity and S. pneumoniae disease. In an AA model, IL-6 deficiency led to increased lung inflammation, eosinophil recruitment, tissue pathology, and collagen deposition. Additionally, IL-6-deficient asthmatic mice exhibited reduced goblet cell hyperplasia and increased TGF-β production. These key changes in the lungs of IL-6-deficient asthmatic mice resulted in dysregulated tight junction proteins and increased lung permeability. Whereas the host response to AA protected against S. pneumoniae lung disease, the IL-6 deficiency abrogated the protective effect of allergic inflammation against S. pneumoniae pathogenesis. Consistent with in vivo data, IL-6 knockdown by small interfering RNA or the blockade of IL-6R signaling exacerbated the TGF-β-induced dysregulation of tight junction proteins, E-cadherin and N-cadherin expression, and STAT3 phosphorylation in MLE-12 epithelial cells. Our findings demonstrate a previously unrecognized role of host IL-6 response in the regulation of lung inflammation during AA and the control of S. pneumoniae bacterial disease. A better understanding of the interactions between lung inflammation and barrier framework could lead to the development of therapies to control asthma inflammation and preserve barrier integrity.

Enhancer Reprogramming within Pre-existing Topologically Associated Domains Promotes TGF-β-Induced EMT and Cancer Metastasis

Transcription growth factor β (TGF-β) signaling-triggered epithelial-to-mesenchymal transition (EMT) process is associated with tumor stemness, metastasis, and chemotherapy resistance. However, the epigenomic basis for TGF-β-induced EMT remains largely unknown. Here we reveal that HDAC1-mediated global histone deacetylation and the gain of specific histone H3 lysine 27 acetylation (H3K27ac)-marked enhancers are essential for the TGF-β-induced EMT process. Enhancers gained upon TGF-β treatment are linked to gene activation of EMT markers and cancer metastasis. Notably, dynamic enhancer gain or loss mainly occurs within pre-existing topologically associated domains (TADs) in epithelial cells, with minimal three-dimensional (3D) genome architecture reorganization. Through motif enrichment analysis of enhancers that are lost or gained upon TGF-β stimulation, we identify FOXA2 as a key factor to activate epithelial-specific enhancer activity, and we also find that TEAD4 forms a complex with SMAD2/3 to mediate TGF-β signaling-triggered mesenchymal enhancer reprogramming. Together, our results implicate that key transcription-factor (TF)-mediated enhancer reprogramming modulates the developmental transition in TGF-β signaling-associated cancer metastasis.

Statin inhibits large hepatitis delta antigen-Smad3 -twist-mediated epithelial-to-mesenchymal transition and hepatitis D virus secretion

Background

Hepatitis D virus (HDV) infection may induce fulminant hepatitis in chronic hepatitis B patients (CHB) or rapid progression of CHB to cirrhosis or hepatocellular carcinoma. There is no effective treatment for HDV infection. HDV encodes small delta antigens (S-HDAg) and large delta antigens (L-HDAg). S-HDAg is essential for HDV replication. Prenylated L-HDAg plays a key role in HDV assembly. Previous studies indicate that L-HDAg transactivates transforming growth factor beta (TGF-β) and induces epithelial-mesenchymal transition (EMT), possibly leading to liver fibrosis. However, the mechanism is unclear.

Methods

The mechanisms of the activation of Twist promoter by L-HDAg were investigated by luciferase reporter assay, chromatin immunoprecipitation, and co-immunoprecipitation analysis. ELISA and Western blotting were used to analyze L-HDAg prenylation, TGF-β secretion, expression of EMT markers, and to evaluate efficacy of statins for HDV treatment.

Results

We found that L-HDAg activated Twist expression, TGF-β expression and consequently induced EMT, based on its interaction with Smad3 on Twist promoter. The treatment of statin, a prenylation inhibitor, resulted in reduction of Twist promoter activity, TGF-β expression, and EMT, and reduces the release of HDV virions into the culture medium.

Conclusions

We demonstrate that L-HDAg activates EMT via Twist and TGF-β activation. Treatment with statins suppressed Twist expression, and TGF-β secretion, leading to downregulation of EMT. Our findings clarify the mechanism of HDV-induced EMT, and provide a basis for possible novel therapeutic strategies against HDV infection.

The Role of NLRP3 Inflammasome Activation in the Epithelial to Mesenchymal Transition Process During the Fibrosis

Fibrosis is considered a complex form of tissue damage commonly present in the end stage of many diseases. It is also related to a high percentage of death, whose predominant characteristics are an excessive and abnormal deposition of fibroblasts and myofibroblasts -derived extracellular matrix (ECM) components. Epithelial-to-mesenchymal transition (EMT), a process in which epithelial cells gradually change to mesenchymal ones, is a major contributor in the pathogenesis of fibrosis. The key mediator of EMT is a multifunctional cytokine called transforming growth factor-β (TGF-β) that acts as the main inducer of the ECM assembly and remodeling through the phosphorylation of Smad2/3, which ultimately forms a complex with Smad4 and translocates into the nucleus. On the other hand, the bone morphogenic protein-7 (BMP-7), a member of the TGF family, reverses EMT by directly counteracting TGF-β induced Smad-dependent cell signaling. NLRP3 (NACHT, LRR, and PYD domains-containing protein 3), in turn, acts as cytosolic sensors of microbial and self-derived molecules and forms an immune complex called inflammasome in the context of inflammatory commitments. NLRP3 inflammasome assembly is triggered by extracellular ATP, reactive oxygen species (ROS), potassium efflux, calcium misbalance, and lysosome disruption. Due to its involvement in multiple diseases, NLRP3 has become one of the most studied pattern-recognition receptors (PRRs). Nevertheless, the role of NLRP3 in fibrosis development has not been completely elucidated. In this review, we described the relation of the previously mentioned fibrosis pathway with the NLRP3 inflammasome complex formation, especially EMT-related pathways. For now, it is suggested that the EMT happens independently from the oligomerization of the whole inflammasome complex, requiring just the presence of the NLRP3 receptor and the ASC protein to trigger the EMT events, and we will present different pieces of research that give controversial point of views.

Metastatic propagation of thyroid cancer; organ tropism and major modulators

Thyroid cancer, as the most prevalent endocrine malignancy, comprises nearly 1% of all cancers in the world. The metastatic propagation of thyroid cancer is under the control of a number of modulating processes and factors such as signaling pathways and their components, cell division regulators, metabolic reprogramming factors, extracellular matrix remodelers, epithelial to mesenchymal transition modulators, epigenetic mechanisms, hypoxia and cytokines. Identifying the exact molecular mechanisms of these dysregulated processes could help to discover the key targets for therapeutic purposes and utilizing them as diagnostic, prognostic and predictors of the clinical course of patients. In this review article, we describe different aspects of thyroid cancer metastasis by focusing on defective genes and pathways involved in its metastatic spread.

New therapeutic targets in chronic kidney disease progression and renal fibrosis

INTRODUCTION

The current therapeutic armamentarium to prevent chronic kidney disease (CKD) progression is limited to the control of blood pressure and in diabetic patients, the strict control of glucose levels. Current research is primarily focused on the reduction of inflammation and fibrosis at different levels.

AREAS COVERED

This article examines the latest progress in this field and places an emphasis on inflammation, oxidative stress, and fibrosis. New therapeutic targets are described and evidence from experimental and clinical studies is summarized. We performed a search in Medline for articles published over the last 10 years.

EXPERT OPINION

The search for therapeutic targets of renal inflammation is hindered by an incomplete understanding of the pathophysiology. The determination of the specific inducers of inflammation in the kidney is an area of heightened potential. Prevention of the progression of renal fibrosis by blocking TGF-β signaling has been unsuccessful, but the investigation of signaling pathways involved in late stages of fibrosis progression could yield improved results. Preventive strategies such as the modification of microbiota-inducers of uremic toxins involved in CKD progression is a promising field because of the interaction between the gut microbiota and the renal system.

Effect of Exposure to Seminal Plasma Through Natural Mating in Cattle on Conceptus Length and Gene Expression

A growing body of evidence suggests that paternal factors have an impact on offspring development. These studies have been mainly carried out in mice, where seminal plasma (SP) has been shown to regulate endometrial gene expression and impact embryo development and subsequent offspring health. In cattle, infusion of SP into the uterus also induces changes in endometrial gene expression, however, evidence for an effect of SP on early embryo development is lacking. In addition, during natural mating, the bull ejaculates in the vagina; hence, it is not clear whether any SP reaches the uterus in this species. Thus, the aim of the present study was to determine whether SP exposure leads to improved early embryo survival and developmental rates in cattle. To this end, Day 7 in vitro produced blastocysts were transferred to heifers (12-15 per heifer) previously mated to vasectomized bulls (n = 13 heifers) or left unmated (n = 12 heifers; control). At Day 14, heifers were slaughtered, and conceptuses were recovered to assess size, morphology and expression of candidate genes involved in different developmental pathways. Additionally, CL volume at Day 7, and weight and volume of CL at Day 14 were recorded. No effect of SP on CL volume and weight not on conceptus recovery rate was observed. However, filamentous conceptuses recovered from SP-exposed heifers were longer in comparison to the control group and differed in expression of CALM1, CITED1, DLD, HNRNPDL, PTGS2, and TGFB3. In conclusion, data indicate that female exposure to SP during natural mating can affect conceptus development in cattle. This is probably achieved through modulation of the female reproductive environment at the time of mating.

Long noncoding RNAs in osteosarcoma via various signaling pathways

Osteosarcoma is one of the most commonly seen bone malignancies with high incidence rate in both children and adults. Although the regulatory network of osteosarcoma has been greatly concerned for years, the mechanisms regarding its oncogenesis and development are still not clear. Recent discoveries have revealed that long noncoding RNAs (lncRNAs) play a crucial role in the development, progression, and invasion of osteosarcoma. Deregulated expression of lncRNAs has been found to participate in the regulation of various signaling transduction pathways in osteosarcoma. This review summarized roles of lncRNAs in the pathogenesis, development, and potential therapeutic of osteosarcoma via different signaling pathways. For examples, MALAT1, CCAT2, FER1L4, LOXL1‐AS1, OIP5‐AS1, PVT1, DBH‐AS1, and AWPPH regulate PI3K/Akt signaling; AWPPH and BE503655 regulate Wnt/β‐catenin signaling; NKILA and XIST regulate NF‐κB signaling; MEG3 and SNHG12 regulate Notch signaling; FOXD2‐AS1 and LINK‐A regulate HIF‐1α signaling; GClnc1 and HOTAIR regulate P53 signaling; ZFAS1, H19, and MALAT1 regulate MAPK, Hedgehog and Rac1/JNK signaling, respectively.

Curcumin Inhibits Proliferation and Epithelial-Mesenchymal Transition in Lens Epithelial Cells through Multiple Pathways

Background

Posterior capsule opacification (PCO), a complication of extracapsular lens extraction surgery that causes visual impairment, is characterized by aberrant proliferation and epithelial-mesenchymal transition (EMT) of lens epithelial cells (LECs). Curcumin, exerting inhibitive effects on cell proliferation and EMT in cancer, serves as a possible antidote towards PCO.

Methods

Cellular proliferation of LECs after treatment of curcumin was measured with MTT assay and flow cytometry. The transcriptional and expressional levels of proteins related to proliferation and EMT of LECs were quantified by western blotting and real-time PCR.

Results

Curcumin was found to suppress the proliferation of LECs by inducing G₂/M arrest via possible inhibition of cell cycle-related proteins including CDK1, cyclin B1, and CDC25C. It had also inactivated proliferation pathways involving ERK1/2 and Akt pathways in LECs. On the other hand, curcumin downregulated the EMT of LECs through blocking the TGF-β/Smad pathway and interfering Notch pathway which play important roles in PCO.

Conclusions

This study shows that curcumin could suppress the proliferation and EMT in LECs, and it might be a potential therapeutic protection against visual loss induced by PCO.

Ionizing Radiation Promotes Epithelial-to-Mesenchymal Transition in Lung Epithelial Cells by TGF-β-producing M2 Macrophages

BACKGROUND/AIM

Ionizing radiation induces pulmonary fibrosis, which is a common dose-limiting complication in patients receiving radiotherapy. Fibrosis occurs through the accumulation of large amounts of ECM components, synthesized by myofibroblasts in damaged lung tissue. Epithelial cells serve as one of the cellular sources of myofibroblasts via the epithelial-to-mesenchymal transition (EMT) process. In this study, we investigated the role of TGF-β-secreting M2 macrophages in association with ionizing radiation-induced EMT.

MATERIALS AND METHODS

The lung epithelial cell line MLE12, was irradiated and the expression of EMT markers and chemokines was examined. Moreover, the mouse lung macrophage MH-S cell line was cultured with conditioned media from irradiated MLE12 cells, to examine the effects of the secreted factors on the migration ability of macrophages. For the murine pulmonary fibrosis model, mice were locally irradiated and the levels of M1 or M2 macrophage-related markers and cytokines were measured in bronchoalvelolar lavage (BAL) fluid and lung tissue.

RESULTS

In MLE12 cells, irradiation directly induced expression of EMT-related markers and secretion of various chemokines, which lead to macrophage migration. Interestingly, the sub-population of macrophages recruited in the lung of mice after thoracic irradiation was M2 macrophages that expressed Arg-1 and CD206. M2 macrophages induced the MLE12 to undergo phenotypic conversion to form fibroblast-like cells, which leads to a down-regulation of epithelial markers and an up-regulation of new EMT-related markers. In thoracic irradiated mice, pro-inflammatory cytokines such as IL-1β, IL-4 and IL-10 were increased at 2 weeks, but returned to normal levels from 16 weeks or 24 weeks after irradiation. However, thoracic irradiation led to a rapid increase of TGF-β and IGF-1 levels, which lasted up to 24 weeks. It was confirmed that M2 macrophages secreted the high levels of TGF-β. Moreover, the elimination of TGF-β from M2 macrophages attenuated mesenchymal transition of MLE12.

CONCLUSION

TGF-β-secreting M2 macrophages play an important regulatory role in mesenchymal transition of epithelial cells in the lung of irradiated mice, thus contributing to radiation-induced pulmonary fibrosis.

The (pro)renin receptor: a novel biomarker and potential therapeutic target for various cancers

BACKGROUND

The (pro) renin receptor ((P)RR) plays important roles in various pathways, such as the Wnt/β-catenin, renin-angiotensin system (RAS), MAPK/ERK and PI3K/AKT/mTOR pathways, that are involved in a wide range of physiological and pathological processes incorporating the tumorigenesis. However, our knowledge about (P) RR was mostly limited to its roles in cardiovascular and renal physiological functions and diseases. In the past 5 years, however, compelling evidence has revealed that (P) RR is aberrantly expressed in and contributes to the development of various cancers by different means. For instance, (P) RR was recently demonstrated to induce the oncogenesis of pancreatic, colorectal and brain cancers via the Wnt signaling, while promote the endometrial cancer and glioblastoma through the RAS.

METHODS

Combining with the deep analysis of big data from The Cancer Genome Atlas (TCGA) and Genotype-Tissue Expression (GTEx) databases, this review updates and summarizes the recent studies about the newly recognized roles of (P) RR in the pathophysiological processes of cancer development and its detailed functions through related pathways, as well as the novel research progress of (P) RR in related fields including the development and application of soluble (P) RR detection kit and monoclonal (P) RR antibody.

RESULTS

This review provides an overview of the essential roles of (P) RR in the tumorigenesis and progression of various cancers and offers a translational outlook for the future research and clinical practices.

CONCLUSION

(P) RR in the tumor tissues and/or body fluids of patients may be a novel and promising biomarker and potential therapeutic target for diagnosis, treatment and prognosis prediction in various cancers. Video Abstract.

A Novel Model of Cancer Drug Resistance: Oncosomal Release of Cytotoxic and Antibody-Based Drugs

Extracellular vesicles (EVs), such as exosomes or oncosomes, often carry oncogenic molecules derived from tumor cells. In addition, accumulating evidence indicates that tumor cells can eject anti-cancer drugs such as chemotherapeutics and targeted drugs within EVs, a novel mechanism of drug resistance. The EV-releasing drug resistance phenotype is often coupled with cellular dedifferentiation and transformation in cells undergoing epithelial-mesenchymal transition (EMT), and the adoption of a cancer stem cell phenotype. The release of EVs is also involved in immunosuppression. Herein, we address different aspects by which EVs modulate the tumor microenvironment to become resistant to anticancer and antibody-based drugs, as well as the concept of the resistance-associated secretory phenotype (RASP).

Role of fibrillin-2 in the control of TGF-β activation in tumor angiogenesis and connective tissue disorders

Fibrillins constitute a family of large extracellular glycoproteins which multimerize to form microfibrils, an important structure in the extracellular matrix. It has long been assumed that fibrillin-2 was barely present during postnatal life, but it is now clear that fibrillin-2 molecules form the structural core of microfibrils, and are masked by an outer layer of fibrillin-1. Mutations in fibrillins give rise to heritable connective tissue disorders, including Marfan syndrome and congenital contractural arachnodactyly. Fibrillins also play an important role in matrix sequestering of members of the transforming growth factor-β family, and in context of Marfan syndrome excessive TGF-β activation has been observed. TGF-β activation is highly dependent on integrin binding, including integrin αvβ8 and αvβ6, which are upregulated upon TGF-β exposure. TGF-β is also involved in tumor progression, metastasis, epithelial-to-mesenchymal transition and tumor angiogenesis. In several highly vascularized types of cancer such as hepatocellular carcinoma, a positive correlation was found between increased TGF-β plasma concentrations and tumor vascularity. Interestingly, fibrillin-1 has a higher affinity to TGF-β and, therefore, has a higher capacity to sequester TGF-β compared to fibrillin-2. The previously reported downregulation of fibrillin-1 in tumor endothelium affects the fibrillin-1/fibrillin-2 ratio in the microfibrils, exposing the normally hidden fibrillin-2. We postulate that fibrillin-2 exposure in the tumor endothelium directly stimulates tumor angiogenesis by influencing TGF-β sequestering by microfibrils, leading to a locally higher active TGF-β concentration in the tumor microenvironment. From a therapeutic perspective, fibrillin-2 might serve as a potential target for future anti-cancer therapies.

A Truncated Snail1 Transcription Factor Alters the Expression of Essential EMT Markers and Suppresses Tumor Cell Migration in a Human Lung Cancer Cell Line

BACKGROUND

Epithelial-to-Mesenchymal Transition (EMT) is necessary for metastasis. Zinc- finger domain-containing transcription factors, especially Snail1, bind to E-box motifs and play a crucial role in the induction and regulation of EMT.

OBJECTIVE

We hypothesized if C-terminal region of Snail1 (CSnail1) may competitively bind to E-box and block cancer metastasis.

METHODS

The CSnail1 gene coding sequence was inserted into the pIRES2-EGFP vector. Following transfection of A549 cells with the designed construct, EMT was induced with TGF-β1 and the expression of essential EMT markers was evaluated by real-time PCR and immunoblotting. We also monitored cell migration.

RESULTS

CSnail1 inhibited TGF-β1-induced N-cadherin and vimentin mRNA expression and increased β-catenin expression in transfected TGF-β1-treated A549 cells. A similar finding was obtained in western blotting. CSnail1 also blocked the migration of transfected cells in the scratch test.

CONCLUSION

Transfection of A549 cells with CSnail1 alters the expression of essential EMT markers and consequently suppresses tumor cell migration. These findings confirm the capability of CSnail1 in EMT blocking and in parallel to current patents could be applied as a novel strategy in the prevention of metastasis.

Degradation of different molecular weight fucoidans and their inhibition of TGF-β1 induced epithelial-mesenchymal transition in mouse renal tubular epithelial cells

In order to investigate the anti-fibrotic effect of different molecular weight (Mw) fucoidans on TGF-β1-induced mouse renal tubular epithelial cell (MTEC) mode. Oxidative degradation method was used to obtain fucoidans with different molecular weights and the reaction time, reaction temperature and the concentration of oxidants were investigated. Cell viability was detected by CCK-8, and EMT markers expression was detected by Western-bolt and Cell immunofluorescence assay. As a result, after chemical analysis of three independent batches of prepared samples, one batch of fucoidan sample (LHX 1-9) which chemical contents are similar but Mw ranging from 3.3 KDa to 49.3 KDa were selected to do further research. We found LHX1 (Mw = 3.3 KDa) and LHX 3-9 (Mw = 6.6 KDa, 8.3 KDa, 11.3 KDa, 14.9 KDa, 25.2 KDa, 35.4 KDa, 49.3 KDa) could resist the TGF-β1-induced depithelial-mesenchymal transition (EMT) by decreased expression of Fn and CTGF and maintained epithelial cell morphology in MTEC. However, the relationship between the Mw of fucoidans and their anti-EMT effect is not simply linear. Among the samples, LHX 1, 5 and 8 showed significant anti-EMT effects than others by de-regulated Fn and CTGF expression on MTEC cells.

Quercetin Inhibits Cell Survival and Metastatic Ability via the EMT-mediated Pathway in Oral Squamous Cell Carcinoma

This study aimed to investigate whether quercetin exerts anticancer effects on oral squamous cell carcinoma (OSCC) cell lines and to elucidate its mechanism of action. These anticancer effects in OSCC cells were assessed using an MTT assay, flow cytometry (to assess the cell cycle), wound-healing assay, invasion assay, Western blot analysis, gelatin zymography, and immunofluorescence. To investigate whether quercetin also inhibits transforming growth factor β1 (TGF-β1)-induced epithelial-mesenchymal transition (EMT) in human keratinocyte cells, HaCaT cells were treated with TGF-β1. Overall, our results strongly suggest that quercetin suppressed the viability of OSCC cells by inducing cell cycle arrest at the G2/M phase. However, quercetin did not affect cell viability of human keratinocytes such as HaCaT (immortal keratinocyte) and nHOK (primary normal human oral keratinocyte) cells. Additionally, quercetin suppresses cell migration through EMT and matrix metalloproteinase (MMP) in OSCC cells and decreases TGF-β1-induced EMT in HaCaT cells. In conclusion, this study is the first, to our knowledge, to demonstrate that quercetin can inhibit the survival and metastatic ability of OSCC cells via the EMT-mediated pathway, specifically Slug. Quercetin may thus provide a novel pharmacological approach for the treatment of OSCCs.

Unusual clinical and histologic findings in a child with mixed dentition with hereditary gingival fibromatosis: a case report

Hereditary gingival fibromatosis (HGF) is characterized by an accumulation of extracellular matrix resulting in a fibrotic enlargement of keratinized gingiva. The goal of this article is to describe one kindred affected with HGF and discuss the diagnosis, treatment, recurrence risk and histopathology features of the proband with mixed dentition. An 8-year-old boy reported with a chief complaint of gingival enlargement. A series of examinations were performed to make a diagnosis and family histories of the patient were recorded. Surgical therapy included gingivectomy and gingivoplasty technique were performed for the proband to remove excess gingiva. Collagen bundles in the permanent incisors area were prevalently significantly bulkier than that of the deciduous teeth area and the arrangement was much more regular. Microscopic evaluation revealed that epithelial hyperplasia was severe in tissue with intense inflammation, whereas tissue with mild inflammation showed only long and deep epithelial papillae. The patient was placed on a 3-month recall schedule and didn't demonstrate any recurrence of gingival overgrowth over a 1-year follow-up period. The study revealed that the eruption of permanent teeth played an important role in accelerating gingival hyperplasia. For the first time, it was confirmed from histological perspective that inflammation in gingival tissue was crucial to the gingival overgrowth of HGF.

Integrative Transcriptomic Analysis Reveals a Multiphasic Epithelial-Mesenchymal Spectrum in Cancer and Non-tumorigenic Cells

Epithelial-mesenchymal transition (EMT), the conversion between rigid epithelial cells and motile mesenchymal cells, is a reversible cellular process involved in tumorigenesis, metastasis, and chemoresistance. Numerous studies have found that several types of tumor cells show a high degree of cell-to-cell heterogeneity in terms of their gene expression signatures and cellular phenotypes related to EMT. Recently, the prevalence and importance of partial or intermediate EMT states have been reported. It is unclear, however, whether there is a general pattern of cancer cell distribution in terms of the overall expression of epithelial-related genes and mesenchymal-related genes, and how this distribution is related to EMT process in normal cells. In this study, we performed integrative transcriptomic analysis that combines cancer cell transcriptomes, time course data of EMT in non-tumorigenic epithelial cells, and epithelial cells with perturbations of key EMT factors. Our statistical analysis shows that cancer cells are widely distributed in the EMT spectrum, and the majority of these cells can be described by an EMT path that connects the epithelial and the mesenchymal states via a hybrid expression region in which both epithelial genes and mesenchymal genes are highly expressed overall. We found that key patterns of this EMT path are observed in EMT progression in non-tumorigenic cells and that transcription factor ZEB1 plays a key role in defining this EMT path via diverse gene regulatory circuits connecting to epithelial genes. We performed Gene Set Variation Analysis to show that the cancer cells at hybrid EMT states also possess hybrid cellular phenotypes with both high migratory and high proliferative potentials. Our results reveal critical patterns of cancer cells in the EMT spectrum and their relationship to the EMT process in normal cells, and provide insights into the mechanistic basis of cancer cell heterogeneity and plasticity.

CD24 and CK4 are upregulated by SIM2, and are predictive biomarkers for chemoradiotherapy and surgery in esophageal cancer

Definitive chemoradiotherapy (CRT) is a less invasive therapy compared with surgery for some types of cancer; however, the 5‑year survival rate of patients with stages II‑III esophageal squamous cell carcinoma (ESCC) is only 37%. Therefore, prediction of CRT responders is necessary. Unfortunately, no definitive biomarker exists that is useful to predict survival outcome following CRT. From our previous microarray study, CD24 and keratin 4 (KRT4), which encodes cytokeratin 4 (CK4), were overexpressed in the favorable prognostic epithelial subtype with SIM bHLH transcription factor 2 (SIM2) expression. This study investigated the association between their mRNA and protein expression levels, and clinicopathological characteristics, and also investigated the functions of CD24 in SIM2‑mediated tumor differentiation and CRT sensitivity. High CD24 and KRT4 mRNA expression was associated with a favorable prognosis following CRT. Multivariate analyses revealed that high CD24 and CK4 protein expression, as determined by immunohistochemistry, and differentiated type were independent factors for predicting a favorable prognosis in response to CRT. Notably, in cases with low CD24 or CK4, surgery was suggested to be a good therapeutic modality compared with CRT. CD24 and KRT4 were expressed preferentially in differentiated layers of the normal esophageal mucosa, and their mRNA expression in 3D cultured ESCC cells was induced by SIM2 transfection, thus suggesting that CD24 and KRT4 were downstream differentiation markers of SIM2. Furthermore, CD24 small interfering RNA increased the mRNA expression levels of superoxide dismutase 2 and enhanced H2O2 resistance, thus indicating the involvement of CD24 in the radiosensitivity of patients with ESCC; however, it had no effect on cisplatin sensitivity. In conclusion, the two markers CD24 and CK4 may be considered predictive biomarkers for definitive CRT.

Downregulation of SEMA4C Inhibit Epithelial-Mesenchymal Transition (EMT) and the Invasion and Metastasis of Cervical Cancer Cells via Inhibiting Transforming Growth Factor-beta 1 (TGF-β1)-Induced Hela cells p38 Mitogen-Activated Protein Kinase (MAPK) Activation

BACKGROUND Epithelial-mesenchymal transition (EMT) plays a key role in promoting invasion and metastasis of tumor cells. SEMA4C can regulate the generation of transforming growth factor-beta 1 (TGF-ß1)-induced EMT in cervical cancer. This study investigated the relationship between the regulation of SEMA4C on TGF-ß1-induced p38 mitogen-activated protein kinase (MAPK) activation and invasion and metastasis of cervical cancer. MATERIAL AND METHODS Hela-shSEMA4C cell line was established and the success of transfection was confirmed with fluorescence intensity. Cell experiments were divided into 2 groups. Group 1 was Hela, Hela-shNC, and Hela-shSEMA4C; and Group 2 was Hela, Hela-shNC, Hela-shSEMA4C, Hela+TGF-ß1, Hela-shNC+TGF-ß1, and Hela-shSEMA4C+TGF-ß1. Group 1 was detected for SEMA4C mRNA expression by real-time polymerase chain reaction (RT-PCR), cell viability by Cell Counting Kit-8 (CCK-8), F-actin fluorescence intensity by immunofluorescence, cell migration by scratch test, and cell invasion by invasion test. Group 2 was analyzed for E-cadherin fluorescence intensity by immunofluorescence, human fibronectin (FN) content by enzyme-linked immunosorbent assay (ELISA), and SEMA4C, E-cadherin and p-p38 expressions by Western blot. RESULTS For Group 1, compared with Hela and Hela-shNC subgroups, the SEMA4C mRNA expression, cell viability, F-actin fluorescence intensity, cell migration and invasion ability in the Hela-shSEMA4C subgroup were significantly decreased (P<0.05). For Group 2, compared with Hela and Hela-shNC subgroups, the E-cadherin expression and fluorescence intensity in the Hela-shSEMA4C subgroup were significantly increased (P<0.01), while the FN content, SEMA4C, and p-p38 MAPK expressions were significantly decreased (P<0.01). Compared with Hela-shNC+TGF-ß1 and Hela+TGF-ß1 subgroups, the E-cadherin expression and fluorescence intensity in the Hela-shSEMA4C+TGF-ß1 subgroup were significantly increased (P<0.01), while the FN content, SEMA4C and p-p38 expressions were significantly decreased (P<0.01). CONCLUSIONS Downregulation of SEMA4C can inhibit EMT and the invasion and metastasis of cervical cancer cells via inhibiting TGF-ß1-induced Hela cells p38 MAPK activation.

Promotion effects of mono-2-ethyhexyl phthalate (MEHP) on migration and invasion of human melanoma cells via activation of TGF-β signals

Malignant melanoma is one of the most leading forms of skin cancer associated with a low patient survival rate. There is an urgent need to illustrate risk factors that can trigger the motility of melanoma cancer cells. Our present study revealed that mono-(2-ethylhexyl)phthalate (MEHP) exposure can significantly increase the in vitro migration and invasion of WM983A and A375 cells. Among the tested cytokines, MEHP can increase the expression of transforming growth factor β (TGF-β). Inhibition of TGF-β via its neutralization antibody can attenuate MEHP-induced cell migration and invasion. Further, upregulation of TGF-β mediated MEHP-induced activation of Smad signals and upregulation of Snail in melanoma cells. Blocking the TGF-β/Smad signal pathway can attenuate MEHP-induced cell migration. Estrogen receptor α (ERα) was essential for MEHP-induced expression of TGF-β. In addition, MEHP can increase the expression of ERα in melanoma cells. Collectively, our study found that MEHP can stimulate the progression of melanoma via TGF-β signals. SIGNIFICANCE: Mono-(2-ethylhexyl)phthalate (MEHP) is the active and most toxic metabolite of di(2-ethylhexyl)phthalate (DEHP). Our present study revealed that MEHP can trigger the in vitro migration and invasion of melanoma cells via upregulation of TGF-β/Snail signals. It revealed that daily exposure to MEHP might be a risk factor for melanoma patients.

Nizam MN, Alshammari A. An Update on the Mechanisms of Phenytoin Induced Gingival Overgrowth

Background:

Phenytoin induced gingival overgrowth, a side effect with multifactorial aetiology, is characterized by an increase in the volume of extracellular tissues, particularly collagenous components, with varying degrees of inflammation.

Objective:

The aim of this paper is to review the available literature regarding the pathophysiological mechanisms of phenytoin induced gingival overgrowth.

Methods:

A thorough literature search of the PubMed/ Embase/ Web of science/ Cochrane central database was conducted to identify the mechanisms involved in the process of phenytoin-induced gingival overgrowth using the following keywords: Phenytoin; Anticonvulsant; Gingival Overgrowth; Gingival Enlargement, Gingival Hyperplasia; Drug Induced Gingival Enlargement; Drug Induced Gingival Overgrowth

Results:

According to the available evidence, several mechanisms have been proposed addressing the pathophysiological mechanism of phenytoin induced gingival overgrowth both at a cellular and molecular level. Evidence suggests that the inflammatory changes in the gingival tissues orchestrate the interaction between phenytoin and fibroblasts particularly resulting in an increase in the extracellular matrix content.

Conclusion:

However, the mechanism of production of inflammatory mediators is not fully understood. This, together with the high prevalence of Phenytoin induced gingival overgrowth, warrants further research in this area in order to develop treatment and preventive strategies for the management of this condition.

Epstein-Barr Virus-Encoded Products Promote Circulating Tumor Cell Generation: A Novel Mechanism of Nasopharyngeal Carcinoma Metastasis

Epstein–Barr virus (EBV) is a specific tumorigenic factor in the pathogenesis of nasopharyngeal carcinoma (NPC). Viral products encoded by EBV (LMP1, LMP2A, EBNA1, and miRNAs) have been shown to promote NPC metastasis. EBV-encoded oncoproteins and miRNAs have been shown to induce epithelial–mesenchymal transition (EMT) indirectly by inducing EMT transcription factors (EMT-TFs). These EBV-encoded products also promote the expression of EMT-TFs through post-transcriptional regulation. EMT contributes to generation of circulating tumor cells (CTCs) in epithelial cancers. CTCs exhibit stem cell characteristics, including increased invasiveness, enhanced cell intravasation, and improved cell survival in the peripheral system. EBV may contribute NPC metastasis through promoting generation of CTCs. Furthermore, CTC karyotypes are associated with NPC staging, therapeutic sensitivity, and resistance. We summarized studies showing that EBV-encoded virus-proteins and miRNAs promote generation of NPC CTCs, and highlighted the associated mechanism. This synthesis indicated that EBV mediates NPC metastasis through generation of CTCs.

Screening and identification of epithelial-to-mesenchymal transition-related circRNA and miRNA in prostate cancer

Epithelial-to-mesenchymal transition (EMT) plays a vital role in the progression and metastasis of prostate cancer. However, the molecular mechanisms underlying prostate cancer metastasis are not fully demonstrated. In this study, EMT was induced by interferon-γ (IFN-γ) in PC-3M IE8 cells. High-throughput sequencing was used to screen the differentially expressed circular RNAs (circRNAs) and miRNAs in the cells with or without IFN-γ treatment. EMT-related circRNAs and miRNAs were further identified by quantitative real-time PCR (qPCR). In addition, the relationships among circRNAs, miRNAs, and mRNA were predicted. After cells were treated with IFN-γ, western blot analysis was conducted to detect the expression levels of EMT markers. E-cadherin expression levels were found to be downregulated, and Twist expression levels were found to be upregulated. Our results also found that IFN-γ promoted PC-3M IE8 cell migration and invasion, indicating that IFN-γ could induce EMT in PC-3M IE8 cells. Furthermore, high-throughput sequencing results revealed 827 upregulated and 1279 downregulated circRNAs and 39 upregulated and 2076 downregulated miRNAs in the IFN-γ group compared with the control group. KEGG analysis showed that both differentially expressed circRNAs and differentially expressed miRNAs were enriched in the MAPK signaling pathway related to EMT. Furthermore, the qPCR results revealed that the expression of hsa_circ_0001085, hsa_circ_0004916, hsa_circ_0001165, hsa-miR-196b-5p, and hsa-miR-187-3p in the IFN-γ group was consistent with the sequencing results. hsa_circ_0001165 and hsa_circ_0001085 were used to construct the network of circRNA-miRNA-mRNA. It was found that hsa_circ_0001165 may regulate TNF expression through hsa-miR-187-3p to induce EMT in prostate cancer cells. In addition, hsa_circ_0001085 may indirectly regulate the PI3K-Akt signaling and TGF-β signaling pathways through hsa-miR-196b-5p and the MAPK signaling pathway through has-miR-451a, which played a regulatory role in prostate cancer cells in the EMT induction model. The results obtained in this study lay the foundation for future study.

Ginkgolic Acid, a SUMO-1 Inhibitor, Inhibits the Progression of Oral Squamous Cell Carcinoma by Alleviating SUMOylation of SMAD4

Small ubiquitin-related modifiers (SUMO) represent a class of ubiquitin-like proteins that are conjugated, like ubiquitin, by a set of enzymes to form cellular regulatory proteins, and play key roles in the control of cell proliferation, differentiation, and apoptosis. We found that ginkgolic acid (GA) can significantly reduce cell vitality in a dose- and time-dependent manner and can also accelerate cyto-apoptosis in both Tca8113 and Cal-27 cells. Migration and wound-healing assays were executed to determine the anti-migration effect of GA in oral squamous cell carcinoma (OSCC) cell lines. GA represses transforming growth factor-β1 (TGF-β1)-induced epithelial-mesenchymal transition (EMT) markers in OSCC cell lines. This investigation is the first evidence that GA suppresses TGF-β1-induced SUMOylation of SMAD4. We show that GA affects the phosphorylation of SMAD2/3 protein and the release of SMAD4. In the xenograft mouse model, the OSCC progression was reduced by GA, effectively suppressing the growth of tumors. In addition, siSMAD4 improved cell migration and viability, which was inhibited by GA in Tca8113 cells. GA suppresses tumorigenicity and tumor progression of OSCC through inhibition of TGF-β1-induced enhancement of SUMOylation of SMAD4. Thus, GA could be a promising therapeutic for OSCC.

Involvement of the TGF-β1 pathway in caveolin-1-associated regulation of head and neck tumor cell metastasis

Head and neck squamous cell carcinoma (HNSCC) is the sixth most frequent malignancy with a 5-year survival rate of 54%. Therefore, disease management improvement is required. The present study aimed to assess the role of caveolin-1 (Cav-1) in the metastasis of head and neck tumor cells. Short hairpin RNA was used to silence Cav-1 expression in Tu686 cells. Proliferation, migration, invasion, morphology and the levels of effector proteins were assessed in cells. Upon Cav-1 silencing, E-cadherin levels were decreased, while vimentin levels were significantly increased. Cell migration, quantified by wound healing and Transwell assays, was significantly increased. Meanwhile, Cav-1 and transforming growth factor β1 (TGF-β1) receptor were identified to be co-localized. In addition, Cav-1-knockdown resulted in increased phosphorylation of SMAD family member 2 (P<0.05), a downstream effector of TGF-β signaling. In addition, there was a mutual regulation, with increasing TGF-β1 levels leading to a dose-dependent decrease of Cav-1 expression levels (P<0.05). These findings indicate that Cav-1 inhibits cell metastasis in HNSCC, suggesting the involvement of the TGF-β signaling pathway.