VEGFC/VEGFR3 axis mediates TGFβ1-induced epithelial-to-mesenchymal transition in non-small cell lung cancer cells

Advances in lymphatic metastasis of non-small cell lung cancer

Lung cancer is a deeply malignant tumor with high incidence and mortality. Despite the rapid development of diagnosis and treatment technology, abundant patients with lung cancer are still inevitably faced with recurrence and metastasis, contributing to death. Lymphatic metastasis is the first step of distant metastasis and an important prognostic indicator of non-small cell lung cancer. Tumor-induced lymphangiogenesis is involved in the construction of the tumor microenvironment, except promoting malignant proliferation and metastasis of tumor cells, it also plays a crucial role in individual response to treatment, especially immunotherapy. Thus, this article reviews the current research status of lymphatic metastasis in non-small cell lung cancer, in order to provide some insights for the basic research and clinical and translational application in this field.

The pathological roles and potential mechanisms of vascular endothelial growth factor receptor-3 in gastric cancer

OBJECTIVE

To investigate the roles and underlying mechanisms of vascular endothelial growth factor receptor-3 (VEGFR-3) in gastric cancer (GC).

METHODS

VEGFR-3 gene expression profiles in human gastric adenocarcinoma (GAC) tissues were analysed using The Cancer Genome Atlas database. Human GC cell lines and were used for in vitro studies. Mouse models of GC and distant metastasis were used for in vivo studies. Silencing of VEGFR-3 gene expression was achieved using small interfering RNA.

RESULTS

VEGFR-3 gene expression was significantly elevated in GAC tissues and GC cells. Higher VEGFR-3 expression was positively correlated with more advanced stages and a greater number of metastatic lymph nodes. In vitro studies in GC cells showed that knockdown of VEGFR-3 gene expression significantly suppressed cell proliferation and migration, but promoted apoptosis. In vivo investigations revealed that silencing of VEGFR-3 gene expression exhibited significant inhibition on tumour growth and metastasis. Further mechanistic studies showed that VEGFR-3 exerted its pathological roles by affecting the key molecules in the apoptotic and epithelial-mesenchymal transition pathways.

CONCLUSION

The molecular pathways associated with VEGFR-3-mediated pathological effects could be targets in the development of novel approaches for the diagnosis, prognosis and treatment of GC.

Tumor-derived small extracellular vesicles in cancer invasion and metastasis: molecular mechanisms, and clinical significance

The production and release of tumor-derived small extracellular vesicles (TDSEVs) from cancerous cells play a pivotal role in the propagation of cancer, through genetic and biological communication with healthy cells. TDSEVs are known to orchestrate the invasion-metastasis cascade via diverse pathways. Regulation of early metastasis processes, pre-metastatic niche formation, immune system regulation, angiogenesis initiation, extracellular matrix (ECM) remodeling, immune modulation, and epithelial-mesenchymal transition (EMT) are among the pathways regulated by TDSEVs. MicroRNAs (miRs) carried within TDSEVs play a pivotal role as a double-edged sword and can either promote metastasis or inhibit cancer progression. TDSEVs can serve as excellent markers for early detection of tumors, and tumor metastases. From a therapeutic point of view, the risk of cancer metastasis may be reduced by limiting the production of TDSEVs from tumor cells. On the other hand, TDSEVs represent a promising approach for in vivo delivery of therapeutic cargo to tumor cells. The present review article discusses the recent developments and the current views of TDSEVs in the field of cancer research and clinical applications.

LncRNAs and PTEN/PI3K signaling: A symphony of regulation in cancer biology

The Emergence of Long Non-coding RNAs (lncRNAs) as Key Regulators in Diverse Biological Processes: A Paradigm Shift in Understanding Gene Expression and its Impact on Cancer. The PTEN/PI3K pathway, a pivotal signaling cascade involved in cancer progression, orchestrates critical cellular functions such as survival, proliferation, and growth. In light of these advances, our investigation delves into the intricate and multifaceted interplay between lncRNAs and the PTEN/PI3K signaling pathway, unearthing previously undisclosed mechanisms that underpin cancer growth and advancement. These elusive lncRNAs exert their influence through direct targeting of the PTEN/PI3K pathway or by skillfully regulating the expression and activity of specific lncRNAs. This comprehensive review underscores the paramount significance of the interaction between lncRNAs and the PTEN/PI3K signaling pathway in cancer biology, unveiling an auspicious avenue for novel diagnostic tools and targeted therapeutic interventions. In this review, we navigate through the functional roles of specific lncRNAs in modulating PTEN/PI3K expression and activity. Additionally, we scrutinize their consequential effects on downstream components of the PTEN/PI3K pathway, unraveling the intricacies of their mutual regulation. By advancing our understanding of this complex regulatory network, this study holds the potential to revolutionize the landscape of cancer research, paving the way for tailored and efficacious treatments to combat this devastating disease.

Pseudogene MSTO2P Interacts with miR-128-3p to Regulate Coptisine Sensitivity of Non-Small-Cell Lung Cancer (NSCLC) through TGF-β Signaling and VEGFC

Background

Coptisine has been widely used for treating a variety of cancer types. To date, whether pseudogene is implicated in coptisine resistance of NSCLC remains unknown.

Methods

We performed MTT to assess the cell viability of A549 and Calu-1 cells. The transwell assay was used to examine the invasion of cells. TUNEL was used to determine apoptosis.

Results

Our data showed that coptisine treatment suppressed cell viability and invasion of NSCLC cells while contributing to apoptosis. MiR-128-3p negatively regulated MSTO2P. miR-128-3p reverted MSTO2P knockdown-attenuated cell viability and invasion, as well as promoted cell apoptosis of A549 cells. Moreover, we identified TGF-β signaling and VEGFC as key downstream effectors for MSTO2P and miR-128-3p in A549 cells. MiR-128-3p mimic inhibited TGF-β pathway-associated genes (TGFBR1, Smad2, Smad5, and Smad9), whereas miR-128-3p inhibitor exerted opposite effect. MSTO2P knockdown led to attenuated expression levels of TGFBR1, Smad2, Smad5 and Smad9. VEGFC overexpression greatly rescued miR-128-3p-modulated cell viability, invasion, and apoptosis of A549 cells.

Conclusion

MSTO2P plays a role in coptisine therapy of NSCLC through miR-128-3p. The findings will advance our understanding of NSCLC treatment.

SYT-SSX1 enhances the invasiveness and maintains stem-like cell properties in synovial sarcoma via induction of TGF-β1/Smad signaling

Background

Synovial sarcoma (SS) is a type of soft tissue sarcoma (STS) of undetermined tissue origin, which is characterized by the recurrent pathognomonic chromosomal translocation t (X;18)(p11.2; q11.2). Studies have shown that SS is a malignant tumor originating from cancer stem cells or pluripotent mesenchymal stem cells and may be related to fusion genes. In addition, some studies have indicated that the induction of epithelial–mesenchymal transition (EMT) via the TGF-β1/Smad signaling pathway leads to SS metastasis.

Methods

We analyzed the effects of SYT-SSX1 on the stemness of SS cells via TGF-β1/Smad signaling in vitro. The SYT-SSX1 fusion gene high expression cell was constructed by lentiviral stable transfer technology. SYT-SSX1 and SW982 cells were cultured and tested for sphere-forming ability. The transwell migration assay and flow cytometry were used to assess the migration ability of the sphere cells as well as the expression of CSC-related markers. We treated SYT-SSX1 cells with rhTGF-β1 (a recombinant agent of the TGF-β1 signaling pathway) and SB431542 and observed morphological changes. A CCK-8 experiment and a western blot (WB) experiment were conducted to detect the expression of TGF-β1 signaling pathway- and EMT-related proteins after treatment. The SYT-SSX1 cells were then cultured and their ability to form spheres was tested. Flow cytometry, WB, and quantitative real-time polymerase chain reaction (qRT-PCR) were used to detect the expression of CSC surface markers on SYT-SSX1 sphere cells.

Results

It was found that SYT-SSX1 has stronger sphere-forming ability, migration ability, and higher expression of CSC-related molecules than SW982 cells. Through treating SYT-SSX1 and SW982 cells with rhTGF-β1 and SB431542, we found that TGF-β1 enhanced the proliferation of cells, induced EMT, and that TGF-β1 enhanced the characteristics of tumor stem cells.

Conclusions

Our results suggest that SYT-SSX1 enhances invasiveness and maintains stemness in SS cells via TGF-β1/Smad signaling. These findings reveal an effective way to potentially improve the prognosis of patients with SS by eliminating the characteristics of cancer stem cells (CSCs) during treatment.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12885-022-09229-5.

Vascular growth factors as potential new treatment in cardiorenal syndrome in diabetes

BACKGROUND

Cardiorenal syndrome in diabetes is characterised by alterations of the cardiovascular system paralleled by kidney disease with progressive renal function decline. In diabetes, chronic metabolic and haemodynamic perturbations drive endothelial dysfunction, inflammation, oxidative stress and progressive tissue fibrosis which, in turn, lead to heart and renal anatomo-functional damage. In physiology, vascular growth factors have been implicated in vascular homeostasis; their imbalance, in disease setting such as diabetes, leads to vascular dysfunction and cardiorenal damage.

AIMS

To define the role of vascular growth factors and angiopoietins in cardiorenal syndrome.

MATERIAL AND METHODS

We will focus on the two most studied vascular growth factors, vascular endothelial growth factor (VEGF) and angiopoietins (Angpt). The balance and crosstalk between these growth factors are important in organ development and in the maintenance of a healthy vasculature, heart and kidney. The observed alterations in expression/function of these vascular growth factors, as seen in diabetes, are a protective response against external perturbations.

RESULTS

The chronic insults driving diabetes-mediated cardiorenal damage results in a paradoxical situation, whereby the vascular growth factors imbalance becomes a mechanism of disease. Studies have explored the possibility of modulating the expression/action of vascular growth factors to improve disease outcome. Experimental work has been conducted in animals and has been gradually translated in humans.

DISCUSSION

Difficulties have been encountered especially when considering the magnitude, timing and duration of interventions targeting a selective vascular growth factor. Targeting VEGF in cardiovascular disease has been challenging, while modulation of the Angpt system seems more promising.

CONCLUSION

Future studies will establish the translatability of therapies targeting vascular growth factors for heart and kidney disease in patients with diabetes.

BACH1 promotes the progression of esophageal squamous cell carcinoma by inducing the epithelial-mesenchymal transition and angiogenesis

Metastasis to regional lymph nodes or distal organs predicts the progression of the disease and poor prognosis in esophageal squamous cell carcinoma (ESCC). Previous studies demonstrated that BTB and CNC homology 1 (BACH1) participates in various types of tumor metastasis. However, the function of BACH1 in ESCC was rarely reported. The present study demonstrated that BACH1 protein was overexpressed in ESCC tissues compared with paired esophageal epithelial tissues according to immunohistochemical staining (IHC). Higher levels of BACH1 mRNA were associated with decreased overall survival (OS) and shorter disease‐free survival (DFS) of ESCC patients based on an analysis of The Cancer Genome Atlas (TCGA) datasets. BACH1 significantly enhanced the migration and invasion of ESCC in vitro. Mechanistically, BACH1 promoted the epithelial–mesenchymal transition (EMT) by directly activating the transcription of CDH2, SNAI2, and VIM, as determined by chromatin immunoprecipitation‐quantitative polymerase chain reaction (ChIP‐qPCR). BACH1 overexpression significantly enhanced CDH2 promoter activity according to the results of a luciferase assay. The results of subsequent experiments indicated that BACH1 enhanced the growth of tumor xenografts. The density of CD31⁺ blood vessels and the expression of vascular endothelial growth factor C (VEGFC) in tumor xenografts were significantly associated with BACH1 levels according to the results of IHC and immunofluorescence (IF) analyses performed in vivo. Moreover, ChIP‐qPCR analysis demonstrated that the transcriptional activity of VEGFC was also upregulated by BACH1. Thus, BACH1 contributes to ESCC metastasis and tumorigenesis by partially facilitating the EMT and angiogenesis, and BACH1 may be a promising therapeutic target or molecular marker in ESCC.

LSD1-mediated stabilization of SEPT6 protein activates the TGF-β1 pathway and regulates non-small-cell lung cancer metastasis

Non-small cell lung cancer (NSCLC) is a prevalent cancer with unfavorable prognosis. Over the past decade accumulating studies have reported an involvement of lysine-specific histone demethylase 1 (LSD1) in NSCLC development. Here, we aimed to explore whether LSD1 affects the metastasis of NSCLC by mediating Septin 6 (SEPT6) through the TGF-β1 pathway. RT-qPCR was used to determine LSD1 and SEPT6 expression in NSCLC tissues and cells. Interactions between LSD1, SEPT6, and TGF-β1 were detected using lentivirus-mediated silencing of LSD1 and overexpression of SEPT6. The role of LSD1 and SEPT6 in mediating the biological behavior of NSCLC cells was determined using the EdU proliferation assay, Transwell assay, and flow cytometry. Thereafter, transplanted cell tumors into nude mice were used to explore the in vivo effects of LSD1 and SEPT6 on metastasis of NSCLC. LSD1 and SEPT6 were overexpressed in NSCLC tissue and cell samples. LSD1 could demethylate the promoter of the SEPT6 to positively regulate SEPT6 expression. LSD1 promoted proliferation, migration, and invasion, while suppressing the apoptosis of NSCLC cells by increasing SEPT6 expression. LSD1-mediated SEPT6 accelerated in vivo NSCLC metastasis through the TGF-β1/Smad pathway. Collectively, LSD1 demethylates SEPT6 promoter to upregulate SEPT6, which activates TGF-β1 pathway, thereby promoting metastasis of NSCLC.

Gestational Exposure to Cigarette Smoke Suppresses the Gasotransmitter H2S Biogenesis and the Effects Are Transmitted Transgenerationally

Rationale: Gestational cigarette smoke (CS) impairs lung angiogenesis and alveolarization, promoting transgenerational development of asthma and bronchopulmonary dysplasia (BPD). Hydrogen sulfide (H₂S), a proangiogenic, pro-alveolarization, and anti-asthmatic gasotransmitter is synthesized by cystathionine-γ-lyase (CSE), cystathionine-β-synthase (CBS), and 3-mercaptopyruvate sulfur transferase (3MST). Objective: Determine if gestational CS exposure affected the expression of H₂S synthesizing enzymes in the mouse lung and human placenta. Methods: Mice were exposed throughout gestational period to secondhand CS (SS) at approximating the dose of CS received by a pregnant woman sitting in a smoking bar for 3 h/days during pregnancy. Lungs from 7-days old control and SS-exposed pups and human placenta from mothers who were either non-smokers or smokers during pregnancy were analyzed for expression of the enzymes. Measurements: Mouse lungs and human placentas were examined for the expression of CSE, CBS, and 3MST by immunohistochemical staining, qRT-PCR and/or Western blot (WB) analyses. Results: Compared to controls, mouse lung exposed gestationally to SS had significantly lower levels of CSE, CBS, and 3MST. Moreover, the SS-induced suppression of CSE and CBS in F1 lungs was transmitted to the F2 generation without significant change in the magnitude of the suppression. These changes were associated with impaired epithelial-mesenchymal transition (EMT)-a process required for normal lung angiogenesis and alveolarization. Additionally, the placentas from mothers who smoked during pregnancy, expressed significantly lower levels of CSE, CBS, and 3MST, and the effects were partially moderated by quitting smoking during the first trimester. Conclusions: Lung H₂S synthesizing enzymes are downregulated by gestational CS and the effects are transmitted to F2 progeny. Smoking during pregnancy decreases H₂S synthesizing enzymes is human placentas, which may correlate with the increased risk of asthma/BPD in children.

Identification of lung adenocarcinoma biomarkers based on bioinformatic analysis and human samples

Lung adenocarcinoma is one of the most common malignant tumors worldwide. Although efforts have been made to clarify its pathology, the underlying molecular mechanisms of lung adenocarcinoma are still not clear. The microarray datasets GSE75037, GSE63459 and GSE32863 were downloaded from the Gene Expression Omnibus (GEO) database to identify biomarkers for effective lung adenocarcinoma diagnosis and therapy. The differentially expressed genes (DEGs) were identified by GEO2R, and function enrichment analyses were conducted using the Kyoto Encyclopedia of Genes and Genomes (KEGG) and Gene Ontology (GO). The STRING database and Cytoscape software were used to construct and analyze the protein-protein interaction network (PPI). We identified 376 DEGs, consisting of 83 upregulated genes and 293 downregulated genes. Functional and pathway enrichment showed that the DEGs were mainly focused on regulation of cell proliferation, the transforming growth factor β receptor signaling pathway, cell adhesion, biological adhesion, and responses to hormone stimulus. Sixteen hub genes were identified and biological process analysis showed that these 16 hub genes were mainly involved in the M phase, cell cycle phases, the mitotic cell cycle, and nuclear division. We further confirmed the two genes with the highest node degree, DNA topoisomerase IIα (TOP2A) and aurora kinase A (AURKA), in lung adenocarcinoma cell lines and human samples. Both these genes were upregulated and associated with larger tumor size. Upregulation of AURKA in particular, was associated with lymphatic metastasis. In summary, identification of the DEGs and hub genes in our research enables us to elaborate the molecular mechanisms underlying the genesis and progression of lung adenocarcinoma and identify potential targets for the diagnosis and treatment of lung adenocarcinoma.

The EMT transcription factor, Twist1, as a novel therapeutic target for pulmonary sarcomatoid carcinomas

Pulmonary sarcomatoid carcinomas (PSCs) are a rare subtype of non‑small‑cell lung cancer and are typically biphasic neoplasms. No effective treatment for PSCs is currently available in clinical practice. The expression of the epithelial‑mesenchymal transition (EMT) transcription factors, Twist1, Slug and Snail, as well as the EMT phenotype and vasculogenic mimicry (VM) were analysed in 41 PSC and 79 pulmonary squamous carcinoma (PSCC) samples. Compared with the PSCCs, the PSCs exhibited an EMT phenotype and VM, and they also exhibited an increased expression of the Twist1, Slug, Snail and VM markers. Twist1 expression was associated with metastasis and TNM stage. Twist1‑positive patients exhibited a poorer prognosis for overall survival (OS) than those with Twist1‑negative PSCs. Transforming growth factor β1 (TGFβ1) was used to induce an EMT transition in a PSCC cell line. SK‑MES‑1 cells treated with TGFβ1 exhibited an increased expression of Twist1. The EMT phenotype, VM and increased migratory and invasive abilities were induced following TGFβ1 treatment. Importantly, in cells treated with TGFβ1, the EMT phenotype was reversed, VM marker expression was decreased, and the migratory and invasive ability of the PSCC cell line was decreased following Twist1 knockdown. Collectively, this study provides a new perspective of Twist1 in the aggressiveness of PSCs. The identification of Twist1 as an independent marker of poor prognoses may lead to the development of novel strategies for improving the treatment of patients with PSC.

Hsa_circ_0051079 functions as an oncogene by regulating miR-26a-5p/TGF-β1 in osteosarcoma

Background

Osteosarcoma is a most common bone malignant tumor which threatens children and adolescents. Circular RNAs (circRNAs) fundamentally play essential roles in the progress and development of human cancers by sponging with microRNAs (miRNAs). However, the role of circRNAs in osteosarcoma is not clear. The aim of the study was to investigate the roles and molecular mechanism of circRNAs in osteosarcoma.

Results

The data from qRT-PCR showed that circ_0051079 expression was higher in osteosarcoma cells and tissues compared to their normal controls. Meanwhile, bioinformatic analysis indicated that circ_0051079 was a sponge of miR-26a-5p, which was verified by luciferase activity assay. Subsequently, TGF-β1 was verified as a putative target mRNA of miR-26a-5p by luciferase assay. Cellular function assays were conducted and the findings revealed that circ_0051079/miR-26a-5p/TGF-β1 regulated osteosarcoma proliferation and metastasis.

Conclusion

The study demonstrated that circ_0051079 could act as an oncogene via regulating miR-26a-5p/TGF-β1 and a potential biomarker for osteosarcoma diagnose.

Hypoxia promotes vasculogenic mimicry formation by vascular endothelial growth factor A mediating epithelial-mesenchymal transition in salivary adenoid cystic carcinoma

Objectives

To investigate the role of hypoxia in vasculogenic mimicry (VM) of salivary adenoid cystic carcinoma (SACC) and the underlying mechanism involved.

Materials and methods

Firstly, wound healing, transwell invasion, immunofluorescence and tube formation assays were performed to measure the effect of hypoxia on migration, invasion, EMT and VM of SACC cells, respectively. Then, immunofluorescence and RT‐PCR were used to detect the effect of hypoxia on VE‐cadherin and VEGFA expression. And pro‐vasculogenic mimicry effect of VEGFA was investigated by confocal laser scanning microscopy and Western blot. Moreover, the levels of E‐cadherin, N‐cadherin, Vimentin, CD44 and ALDH1 were determined by Western blot and immunofluorescence in SACC cells treated by exogenous VEGFA or bevacizumab. Finally, CD31/ PAS staining was performed to observe VM and immunohistochemistry was used to determine the levels of VEGFA and HIF‐1α in 95 SACC patients. The relationships between VM and clinicopathological variables, VEGFA or HIF‐1α level were analysed.

Results

Hypoxia promoted cell migration, invasion, EMT and VM formation, and enhanced VE‐cadherin and VEGFA expression in SACC cells. Further, exogenous VEGFA markedly increased the levels of N‐cadherin, Vimentin, CD44 and ALDH1, and inhibited the expression of E‐cadherin, while the VEGFA inhibitor reversed these changes. In addition, VM channels existed in 25 of 95 SACC samples, and there was a strong positive correlation between VM and clinic stage, distant metastases, VEGFA and HIF‐1α expression.

Conclusions

VEGFA played an important role in hypoxia‐induced VM through regulating EMT and stemness, which may eventually fuel the migration and invasion of SACC.

Extracellular Acidosis Modulates the Expression of Epithelial-Mesenchymal Transition (EMT) Markers and Adhesion of Epithelial and Tumor Cells

Epithelial-to-mesenchymal transition (EMT) is an important process of tumor progression associated with increased metastatic potential. EMT can be activated by external triggers such as cytokines or metabolic parameters (e.g. hypoxia). Since extracellular acidosis is a common finding in tumors, the aim of the study is to analyze its impact on the expression of EMT markers in vitro and in vivo as well as the functional impact on cell adhesion. Therefore, three tumor and two normal epithelial cell lines were incubated for 24 h at pH 6.6 and the expression of EMT markers was studied. In addition, mRNA expression of transcription and metabolic factors related to EMT was measured as well as the functional impact on cell adhesion, either during acidic incubation or after priming cells in an acidic milieu. E-cadherin and N-cadherin were down-regulated in all tumor and normal cell lines studied, whereas vimentin expression increased in only two tumor and one normal cell line. Down-regulation of the cadherins was seen in total protein and to a lesser extent in surface protein. In vivo an increase in N-cadherin and vimentin expression was found. Acidosis up-regulated Twist1 and Acsl1 but down-regulated fumarate hydratase (Fh). Cell adhesion during acidic incubation decreased in AT1 prostate carcinoma cells whereas preceding acidic priming increased their subsequent adhesion. Low tumor pH is able to modulate the expression EMT-related proteins and by this may affect the stability of the tissue structure.

Role of OCT4 in cancer stem-like cells and chemotherapy resistance

Cancer stem-like cells (CSCs) contribute to the tumorigenicity, progression, and chemoresistance of cancers. It is not known whether CSCs arise from normal stem cells or if they arise from differentiated cancer cells by acquiring self-renewal features. These CSCs share stem cell markers that normal stem cells express. There is a rising interest in octamer-binding transcription factor 4 (OCT4), one of the stem cell factors that are essential in embryogenesis and pluripotency. OCT4 is also overexpressed in CSCs of various cancers. Although the majority of the studies in CSCs reported a positive association between the expression of OCT4 and chemoresistance and an inverse correlation between OCT4 and clinical prognosis, there are studies rebuking these findings, possibly due to the sparsity of stem cells within tumors and the heterogeneity of tumors. In addition, post-translational modification of OCT4 affects its activity and warrants further investigation for its association with chemoresistance and prognosis.

MicroRNA-122 inhibits epithelial-mesenchymal transition of hepatic stellate cells induced by the TGF-β1/Smad signaling pathway

Transforming growth factor (TGF)-β1 may stimulate the activation of hepatic stellate cells (HSCs), resulting in the development of liver fibrosis. As micro RNA (miRNA)-122 is known to be associated with liver inflammation, its effects on the epithelial-mesenchymal transition (EMT) of HSCs through the inhibition of the TGF-β1/drosophila mothers against decapentaplegic protein 4 (Smad4) signaling pathway were investigated. The MTT assay was performed to explore the optimum TGF-β1 concentration suitable for HSC stimulation. Fluorescence microscopy was used to observe the transfection efficiency and reverse transcription-quantitative polymerase chain reaction (RT-qPCR) and western blot analysis were used to observe gene and protein expression levels of α-smooth muscle actin (α-SMA), E-cadherin, N-cadherin and Smad4, respectively, in HSCs treated with TGF-β1 or TGF-β1 and miRNA-122. MTT assay results indicated that the concentration of 10 µg/l TGF-β1 was suitable for maximum growth and survival of HSCs. Notably, the mRNA expression levels of N-cadherin and α-SMA were significantly increased (each, P<0.05), but the expression levels of E-cadherin were decreased following 10 µg/l TGF-β1 treatment. Similar results were observed regarding the protein expression levels of N-cadherin, α-SMA and E-cadherin. Furthermore, the expression of F-actin was increased in the 10 µg/l TGF-β1 treated group compared with the 0 µg/l TGF-β1 treaded group and stretching of the muscle fiber filament was observed. miRNA-122 lentiviral vector transfection significantly decreased the mRNA expression of N-cadherin and increased the mRNA expression of E-cadherin in HSCs stimulated with TGF-β1, as evident from RT-qPCR results. Similar results were also observed regarding the protein expression levels of N-cadherin and E-cadherin. The expression levels of Smad4, the primary component of the TGF-β1 signaling pathway, were significantly lower in cells treated with TGF-β1 and miRNA-122 (P<0.01) compared those treated with TGF-β1. Thus, miRNA-122 may inhibit the activation and EMT of HSCs stimulated by TGF-β1.

MicroRNA-105 promotes epithelial-mesenchymal transition of nonsmall lung cancer cells through upregulating Mcl-1

BACKGROUND

A growing number of microRNAs have been proved to play significant roles in limiting tumor growth and the epithelial-mesenchymal transition (EMT) process of nonsmall cell lung cancer (NSCLC). Present work aims to study the function of microRNA (miR)-105 in EMT of NSCLC cells, which is unrevealed yet.

METHODS

Two NSCLC cell lines A549 and Calu-3 were transfected with miR-105 mimic, inhibitor, or scrambled control. And then the effects of miR-105 were evaluated by performing trypan blue staining, transwell assay, ANNEXIN-FITC/propidium iodide (PI) double staining and Western blot analysis. The expression levels of myeloid cell leukemia-1 (Mcl-1) after transfection were tested by real-time quantitative polymerase chain reaction and Western blot analysis. Whether Mcl-1 was a downstream effector of miR-105, and the involvement of mammalian target of Rapamycin (mTOR) and p38 mitogen-activated protein kinase (p38MAPK) signaling pathways were assessed.

RESULTS

The overexpression of miR-105 significantly increased the viability and migration of A549 and Calu-3, but had no impacts on cell apoptosis. Meanwhile, E-cadherin was remarkably downregulated, and N-cadherin, Vimentin, ZEB1, and Snail were upregulated by miR-105 overexpression. Mcl-1 was positively regulated by miR-105, and the effects of miR-105 overexpression on A549 and Calu-3 cells viability, migration and EMT were all flattened by Mcl-1 silence. Both mTOR and p38MAPK pathways were activated in miR-105-overexpressing and Mcl-1-overexpressing cells. Besides, inhibition of mTOR and p38MAPK pathways by using Rapamycin and VX-702 abolished the regulatory effects of Mcl-1 on EMT.

CONCLUSION

Our study underlines the importance of miR-105 in modulating NSCLC cells EMT. miR-105 promoted the EMT of NSCLC cells possibly via upregulation of Mcl-1 and thereby activation of mTOR and p38MAPK signaling.