Saponins from the roots of Platycodon grandiflorum suppresses TGFβ1-induced epithelial-mesenchymal transition via repression of PI3K/Akt, ERK1/2 and Smad2/3 pathway in human lung carcinoma A549 cells

Herb-Nanoparticle Hybrid System for Improved Oral Delivery Efficiency to Alleviate Breast Cancer Lung Metastasis

Background

Metastasis is a complex process involving multiple factors and stages, in which tumor cells and the tumor microenvironment (TME) play significant roles. A combination of orally bioavailable therapeutic agents that target both tumor cells and TME is conducive to prevent or impede the progression of metastasis, especially when undetectable. However, sequentially overcoming intestinal barriers, ensuring biodistribution in tumors and metastatic tissues, and enhancing therapeutic effects required for efficient therapy remain challenging.

Methods

Inspired by the unique chemical features of natural herbs, we propose an oral herb-nanoparticle hybrid system (HNS) formed through the self-binding of Platycodon grandiflorum-Curcuma zedoaria (HG), a herb pair/group used in clinical practice to treat breast cancer metastasis, to lipid-polymer nanoparticles (LPNs) loaded with silibinin. The molecular structure responsible for HG association with LPNs was assessed using surface-enhanced Raman spectroscopy for HNS surface chemistry characterization. Moreover, the molecular class of HG was identified using UPLC-Orbitrap-MS/MS to further confirm the surface binding. Mucus diffusion and in vivo biodistribution were evaluated using in vitro multiple-particle tracking and environment-responsive fluorescence probe in 4T1 tumor-bearing mice, respectively. The alleviation of breast cancer metastasis was assessed in 4T1 tumor-bearing mice, and the underlying mechanism was investigated.

Results

The HNS reduced particle-mucus interactions by altering hydrophilicity and surface characteristics compared to LPNs. The epithelium transportation of HNS and absorption through Peyer's patch in mice were improved, promoting their biodistribution in the lung and tumor tissues. Furthermore, the HNS alleviated lung metastasis by inducing cell apoptosis and regulating the expression of MMP-9 and TGF-β1, which altered the TME in 4T1 tumor-bearing mice.

Conclusion

HNS provides an appealing system with multi-component binding of herbal medicine to facilitate both oral nanoparticle delivery efficiency and the alleviation of lung metastasis. This strategy may potentially help improve treatment for patients with breast cancer.

Polysaccharides from Platycodon grandiflorum: A review of their extraction, structures, modifications, and bioactivities

Platycodon grandiflorum (P. grandiflorum) has long been used as a food and traditional herbal medicine. As a food, P. grandiflorum is often transformed into pickles for consumption, and as a traditional Chinese medicine, P. grandiflorum clears the lung, nourishes the pharynx, dispels phlegm, and discharges pus. Polysaccharides are among the main active components of P. grandiflorum. Recent literature has described the preparation, identification, and pharmacological activity of these polysaccharides. Studies have shown that these polysaccharides exhibit a variety of significant biological effects in vitro and in vivo, such as immune stimulation and antioxidant, anti-liver injury, anti-apoptosis and antitumour effects. However, there is no systematic summary of the related research articles on P. grandiflorum polysaccharide, which undoubtedly brings some difficulties to the future research. The purpose of this review is to comprehensively describe research progress on the extraction, purification, structural characterization, modification, and biological activity of P. grandiflorum polysaccharides. The shortcomings of recent research are summarized, further research on their biological activity is proposed to provide new reference value for the application of P. grandiflorum polysaccharides in drugs and health products in the future.

Gintonin Isolated from Ginseng Inhibits the Epithelial-Mesenchymal Transition Induced by TGF-β in A549 Lung Cancer Cells

Epithelial-to-mesenchymal transition (EM transition) is a process wherein epithelial cells lose their intrinsic characteristics and cell-cell junctions and differentiate into a mesenchymal phenotype. EM transition is an important feature of cancer invasion and metastasis. In this study, we aimed to investigate the inhibitory effect of gintonin (GT), an ingredient of ginseng, on EM transition using A549 cells. The proliferation of A549 cells was enhanced following treatment with 50, 75, and 100 μg/mL of GT. GT affected EM transition-induced gene and protein expression, specifically that of vimentin (Vim), N-cadherin (N-cad), zinc finger E-box-binding homeobox 1, and Twist in A549 cells. Furthermore, the transforming growth factor beta 1 (TGF-β1)-induced phosphorylation of Smad2 and Smad3 was suppressed by GT treatment. Immunofluorescence staining also showed that GT treatment decreased the TGF-β1-induced expression of Vim and N-cad in A549 cells. Therefore, GT may be used to suppress cancer cell metastasis via maintenance of the cell-cell junction's integrity. However, further studies are required to pave the way for its translation into clinical application in cancer therapeutics.

Comprehensive review on signaling pathways of dietary saponins in cancer cells suppression

Nutrigenomics utilizes high-throughput genomic technologies to reveal changes in gene and protein levels. Excitingly, ever-growing body of scientific findings has provided sufficient evidence about the interplay between diet and genes. Cutting-edge research and advancements in genomics, epigenetics and metabolomics have deepened our understanding on the role of dietary factors in the inhibition of carcinogenesis and metastasis. Dietary saponins, a type of triterpene glycosides, are generally found in Platycodon grandifloras, Dioscorea oppositifolia, asparagus, legumes, and sea cucumber. Wealth of information has started to shed light on pleiotropic mechanistic roles of dietary saponins in cancer prevention and inhibition. In this review, we have attempted to summarize the in vitro research of dietary saponins in the last two decades by searching common databases such as Google Scholar, PubMed, Scopus, and Web of Science. The results showed that dietary saponins exerted anti-cancer activities via regulation of apoptosis, autophagy, arrest cell cycle, anti-proliferation, anti-metastasis, and anti-angiogenesis, by regulation of several critical signaling pathways, including MAPK, PI3K/Akt/mTOR, NF-κB, and VEGF/VEGFR. However, there is no data about the dosage of dietary saponins for practical anti-cancer effects in human bodies. Extensive clinical studies are needed to confirm the effectiveness of dietary saponins for further commercial and medical applications.

The function of microRNA-211 expression in post-fracture bone cell apoptosis involving the transforming growth factor-β/ phosphoinositide 3-kinase signaling pathway

Background

The underlying mechanism of micro (mi)RNA-211 in bone cell apoptosis after fracture remains unclear. This study aimed to determine the effect and function of miRNA-211 in bone cell apoptosis in fracture patients.

Methods

Serum samples were collected from patients with fractures and healthy controls. Serum miR-211 expression was detected by quantitative PCR. MC3T3-E1 cells were transfected with a transforming growth factor (TGF)-β inhibitor and phosphoinositide 3-kinase (PI3K) inhibitor. The viability of MC3T3-E1 cells was detected by the MTT assay, and apoptosis was detected by flow cytometry. Caspase-3/9 activity and the protein expression of TGF-β, PI3K, and p-Akt were detected by western blot and immunoprecipitation.

Results

In the fracture group, miRNA-211 expression was significantly up-regulated compared with controls. We used miRNA-211 mimics to up-regulate miRNA-211 expression, and observed inhibited cell viability and induced apoptosis and lactate dehydrogenase (LDH) activity. miRNA-211 up-regulation also suppressed the expression of TGF-β, PI3K, and p-Akt proteins. Conversely, miRNA-211 down-regulation increased cell viability and reduced apoptosis and LDH activity, as well as inducing the expression of TGF-β, PI3K, and p-Akt. Inhibiting TGF-β decreased the effect of anti-miRNA-211 on osteocyte apoptosis.

Conclusion

Our data indicate that miRNA-211 functions via the TGF-β/PI3K/Akt signaling pathway in patients with fractures.

tRNA-Derived Fragment tRF-17-79MP9PP Attenuates Cell Invasion and Migration via THBS1/TGF-β1/Smad3 Axis in Breast Cancer

tRNA derivatives have been identified as a new kind of potential biomarker for cancer. Previous studies have identified that there were 30 differentially expressed tRNAs derivatives in breast cancer tissue with the high-throughput sequencing technique. This study aimed to investigate the possible biological function and mechanism of tRNA derivatives in breast cancer cells. One such tRF, a 5'-tRF fragment of tRF-17-79MP9PP (tRF-17) was screened in this study, which is processed from the mature tRNA-Val-AAC and tRNA-Val-CAC. tRF-17 with significantly low expression in breast cancer tissues and serum. The level of tRF-17 differentiated breast cancer from healthy controls with sensitivity of 70.4% and specificity of 68.4%. Overexpression of tRF-17 suppressed cells malignant activity. THBS1 (Thrombospondin-1) as a downstream target of tRF-17, and reduction of THBS1 expression also partially recovered the effects of tRF-17 inhibition on breast cancer cell viability, invasion and migration. Besides, THBS1, TGF-β1, Smad3, p-Smad3 and epithelial-to-mesenchymal transition related genes N-cadherin, MMP3, MMP9 were markedly down-regulated in tRF-17 overexpressing cells. Moreover, tRF-17 attenuated the THBS1-mediated TGF-β1/Smad3 signaling pathway in breast cancer cells. In general, the tRF-17/THBS1/TGF-β1/smad3 axis elucidates the molecular mechanism of breast cancer cells invasion and migration and could lead to a potential therapeutic target for breast cancer.

PRP1, a heteropolysaccharide from Platycodonis Radix, induced apoptosis of HepG2 cells via regulating miR-21-mediated PI3K/AKT pathway

Two polysaccharides (PRP1 and PRP2) were isolated from Platycodonis Radix. Preliminary structural analysis indicated that PRP1 was composed of glucose, fructose, and arabinose in a molar ratio of 1:1.91:1.59 with a molecular weight of 440 kDa, whereas PRP2 was composed of arabinose, fructose, and galactose in a molar ratio of 1:1.39:1.18 with a molecular weight of 2.85 kDa. Compared with PRP2, PRP1 exerted stronger anticancer activity in vitro. Treatment with 5-30 μg/ml of PRP1 significantly inhibited the proliferation of HepG2 cells in vitro, and oral administration at the doses of 75-300 mg/kg also reduced the tumor growth in vivo. The miRNA expression patterns of human liver cancer cells HepG2 in vivo under PRP1 treatment were established, and microRNA-21 (miR-21) as the onco-miRNA was appreciably downregulated. PRP1 repressed the expression of miR-21, which directly targeted and suppressed PTEN (a negative regulator of the PI3K/Akt signaling cascade), and subsequently upregulated the expression of PTEN but downregulated the PI3K/AKT pathway, thereby promoting liver cancer cell apoptosis. These findings indicated that PRP1 inhibited the proliferation and induced the apoptosis of HepG2 mainly via inactivating the miR-21/PI3K/AKT pathway. Therefore, PRP1 could be used as a food supplement and candidate for the treatment of liver cancer.

Human amniotic mesenchymal stem cells and their paracrine factors promote wound healing by inhibiting heat stress-induced skin cell apoptosis and enhancing their proliferation through activating PI3K/AKT signaling pathway

Background

Increasing evidence has shown that mesenchymal stem cells (MSCs) yield a favorable therapeutic benefit for thermal burn skin wounds. Human amniotic MSCs (hAMSCs) derived from amniotic membrane have multilineage differentiation, immunosuppressive, and anti-inflammatory potential which makes them suitable for treating skin wounds. However, the exact effects of hAMSCs on the healing of thermal burn skin wounds and their potential mechanisms are not explored.

Methods

hAMSCs were isolated from amniotic membrane and characterized by RT-PCR, flow cytometry, immunofluorescence, and tumorigenicity test. We assessed the effects of hAMSCs and hAMSC conditional medium (CM) on wound healing in a deep second-degree burn injury model of mice. We then investigated the biological effects of hAMSCs and hAMSC-CM on the apoptosis and proliferation of heat stress-injured human keratinocytes HaCAT and dermal fibroblasts (DFL) both in vivo and in vitro. Next, we explored the underlying mechanisms by assessing PI3K/AKT and GSK3β/β-catenin signaling pathways in heat injured HaCAT and DFL cells after hAMSCs and hAMSC-CM treatments using PI3K inhibitor LY294002 and β-catenin inhibitor ICG001. Antibody array assay was used to identify the cytokines secreted by hAMSCs that may activate PI3K/AKT signaling pathway.

Results

Our results showed that hAMSCs expressed various markers of embryonic stem cells and mesenchymal stem cells and have low immunogenicity and no tumorigenicity. hAMSC and hAMSC-CM transplantation significantly promoted thermal burn wound healing by accelerating re-epithelialization with increased expression of CK19 and PCNA in vivo. hAMSCs and hAMSC-CM markedly inhibited heat stress-induced apoptosis in HaCAT and DFL cells in vitro through activation of PI3K/AKT signaling and promoted their proliferation by activating GSK3β/β-catenin signaling. Furthermore, we demonstrated that hAMSC-mediated activation of GSK3β/β-catenin signaling was dependent on PI3K/AKT signaling pathway. Antibody array assay showed that a panel of cytokines including PAI-1, C-GSF, periostin, and TIMP-1 delivered from hAMSCs may contribute to the improvement of the wound healing through activating PI3K/AKT signaling pathway.

Conclusion

Our results demonstrated that hAMSCs and hAMSC-CM efficiently cure heat stress-induced skin injury by inhibiting apoptosis of skin cells and promoting their proliferation through activating PI3K/AKT signaling pathway, suggesting that hAMSCs and hAMSC-CM may provide an alternative therapeutic approach for the treatment of skin injury.

Electronic supplementary material

The online version of this article (10.1186/s13287-019-1366-y) contains supplementary material, which is available to authorized users.

High expression of CCR5 in melanoma enhances epithelial-mesenchymal transition and metastasis via TGFβ1

Chemokine receptors are highly expressed in various cancers and play crucial roles in tumor progression. However, their expression patterns and functions in melanoma are unclear. The present study aimed to identify the chemokine receptors that play critical roles in melanoma progression and unravel the underlying molecular mechanisms. We found that CCR5 was more abundant in melanoma cells than normal cells and was positively associated with tumor malignancy in clinical patients. Animal experiments suggested that CCR5 deficiency in B16/F10 or A375 cells suppressed primary tumor growth and lung metastasis, whereas CCR5 overexpression in B16/F0 cells enhanced primary tumor growth and lung metastasis. CCR5 played a critical role in proliferation and migration of melanoma cells in vitro. Importantly, CCR5 was required for maintenance of the mesenchymal phenotype of metastatic melanoma cells. Mechanistically, CCR5 positively regulated expression of TGFβ1, which in turn induced epithelial-mesenchymal transition and migration via PI3K/AKT/GSK3β signaling. Collectively, our results establish a critical role of CCR5 expressed by melanoma cells in cancer progression and reveal the novel mechanisms controlling this process, which suggests the prognostic value of CCR5 in melanoma patients and provides novel insights into CCR5-targeted strategies for melanoma treatment. Copyright © 2018 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.

Knockout of MTF1 Inhibits the Epithelial to Mesenchymal Transition in Ovarian Cancer Cells

Due to peritoneal metastasis and frequent recurrence, ovarian cancer has the highest mortality among gynecological cancers. Epithelial to mesenchymal transition (EMT) contributes to ovarian tumor metastasis. In this study, we report for the first time that metal regulatory transcription factor 1 (MTF1) was upregulated in ovarian cancer, and its high expression was associated with poor patient survival and disease relapse. Knockout of MTF1 using lentiviral CRISPR/Cas9 nickase vector-mediated gene editing inhibited EMT by upregulating epithelial cell markers E-cadherin and cytokeratin 7, and downregulating mesenchymal markers Snai2 and β-catenin in ovarian cancer SKOV3 and OVCAR3 cells. Loss of MTF1 reduced cell proliferation, migration, and invasion in both SKOV3 and OVCAR3 cells. Knockout of MTF1 upregulated the expression of the KLF4 transcription factor, and attenuated two cellular survival pathways, ERK1/2 and AKT. Our studies demonstrated that MTF1 plays an oncogenic role and contributes to ovarian tumor metastasis by promoting EMT. MTF1 may be a novel biomarker for early diagnosis as well as a drug target for clinical therapy.

A Systems-Level Analysis of Mechanisms of Platycodon grandiflorum Based on A Network Pharmacological Approach

Platycodon grandiflorum (PG) is widely used in Asia for its various beneficial effects. Although many studies were conducted to understand the molecular mechanisms of PG, it is still unclear how the combinations of multiple ingredients work together to exert its therapeutic effects. The aim of the present study was to provide a comprehensive review of the systems-level mechanisms of PG by adopting network pharmacological analysis. We constructed a compound⁻target⁻disease network for PG using experimentally validated and machine-leaning-based prediction results. Each target of the network was analyzed based on previously known pharmacological activities of PG. Gene ontology analysis revealed that the majority of targets were related to cellular and metabolic processes, responses to stimuli, and biological regulation. In pathway enrichment analyses of targets, the terms related to cancer showed the most significant enrichment and formed distinct clusters. Degree matrix analysis for target⁻disease associations of PG suggested the therapeutic potential of PG in various cancers including hepatocellular carcinoma, gastric cancer, prostate cancer, small-cell lung cancer, and renal cell carcinoma. We expect that network pharmacological approaches will provide an understanding of the systems-level mechanisms of medicinal herbs and further develop their therapeutic potentials.

miR-203 inhibits ovarian tumor metastasis by targeting BIRC5 and attenuating the TGFβ pathway

BACKGROUND

We previously reported that miR-203 functions as a tumor suppressor in ovarian cancer cells by directly targeting transcription factor Snai2 and inhibiting epithelial to mesenchymal transition (EMT), whereas BIRC5/survivin promotes EMT. In this study, we tested our hypothesis that miR-203 inhibits ovarian tumor metastasis by suppressing EMT through targeting BIRC5, using an orthotopic ovarian cancer mouse model.

METHODS

We overexpressed miR-203 in ovarian cancer SKOV3 and OVCAR3 cells using a lentiviral vector and examined cell migration and invasion using transwell plates. The small molecule inhibitor, YM155, was used to inhibit survivin expression. miR-203-expressing and control SKOV3 cells were intrabursally injected into immunocompromised NSG female mice. Primary tumors in ovaries and metastatic tumors were collected to determine the expression of survivin and EMT markers using Western blot and immunostaining.

RESULTS

Overexpression of miR-203 inhibits EMT by targeting BIRC5 in ovarian cancer SKOV3 and OVCAR3 cells. miR-203 expression enhances the ability of the survivin inhibitor YM155 to reduce tumor cell migration and invasion in vitro. We further showed that miR-203 expression attenuated the TGFβ pathway in both SKOV3 and OVCAR3 cells. miR-203 expression also inhibited primary tumor growth in ovaries and metastatic tumors in multiple peritoneal organs including liver and spleen.

CONCLUSION

miR-203 inhibits ovarian tumor metastasis by targeting BIRC5/survivin and attenuating the TGFβ pathway.

Hypaconitine inhibits TGF-β1-induced epithelial-mesenchymal transition and suppresses adhesion, migration, and invasion of lung cancer A549 cells

Epithelial-mesenchymal transition (EMT) has been implicated in tumor invasion and metastasis and provides novel strategies for cancer therapy. Hypaconitine (HpA), a diester-diterpenoid alkaloid isolated from the root of the Aconitum species, exhibits anti-inflammatory, analgesic, and especially, cardiotoxic activities. Here, we reported the anti-metastatic potentials of HpA in transforming growth factor-β1 (TGF-β1)-induced EMT in lung cancer A549 cells. The cytotoxic effect of HpA was determined by MTT assay. A549 cells were treated with TGF-β1 with or without HpA co-treatment, and the morphological alterations were observed with a microscopy. The expression of E-cadherin, N-cadherin, and NF-κB was determined by both Western blotting and immunofluorescence analyses. The adhesion, migration, and invasion were detected with Matrigel, wound-healing, and transwell assays, respectively. The expression of Snail was determined by Western blotting. The expression of NF-κB p65, IκBα, and p-IκBα in nuclear and cytosolic extracts was assessed by Western blotting. The results showed that low concentration of HpA (<16 μmol·L^-1) had no obvious cytotoxicity to A549 cells. Morphologically, TGF-β1 treatment induced spindle-shaped alteration in the cells. The upregulation of N-cadherin, NF-κB, and Snail and the downregulation of E-cadherin were detected after TGF-β1 treatment. The adhesion, migration and invasion abilities were also increased by TGF-β1. Besides, TGF-β1 induced expression of Snail in a time-dependent manner. Furthermore, TGF-β1 induced nuclear translocation of NF-κB p65. All these alterations were dramatically inhibited by HpA co-treatment. In addition, the NF-κB inhibitor PDTC showed similar inhibitory effect. In conclusion, these results showed that HpA inhibited TGF-β1-induced EMT in A549 cells, which was possibly mediated by the inactivation of the NF-κB signaling pathway, providing an evidence for anti-cancer effect of HpA.

Platycodon grandiflorum (PG) reverses angiotensin II-induced apoptosis by repressing IGF-IIR expression

ETHNOPHARMACOLOGICAL RELEVANCE

Platycodon grandiflorum (PG) is a Chinese medical plant used for decades as a traditional prescription to eliminate phlegm, relieve cough, reduce inflammation and lower blood pressure. PG also has a significant effect on the cardiovascular systems.

MATERIALS AND METHODS

The aqueous extract of Platycodon grandiflorum (JACQ.) A. DC. root was screened for inhibiting Ang II-induced IGF-IIR activation and apoptosis pathway in H9c2 cardiomyocytes. The effects were also studied in spontaneously hypertensive rats (five groups, n=5) using low and high doses of PG for 50 days. The Ang II-induced IGF-IIR activation was analyzed by luciferase reporter, RT-PCR, western blot and surface IGF-IIR expression assay. Furthermore, the major active constituent of PG was carried out by high performance liquid chromatography-mass spectrometry (HPLC-MS).

RESULTS

Our results indicate that a crude extract of PG significantly suppresses the Ang II-induced IGF-IIR signaling pathway to prevent cardiomyocyte apoptosis. PG extract inhibits Ang II-mediated JNK activation and SIRT1 degradation to reduce IGF-IIR activity. Moreover, PG maintains SIRT1 stability to enhance HSF1-mediated IGF-IIR suppression, which prevents cardiomyocyte apoptosis. In animal models, the administration of PG markedly reduced this apoptotic pathway in the heart of SHRs.

CONCLUSION

Taken together, PG may be considered as an effective treatment for cardiac diseases in hypertensive patients.

Molecular mechanisms and clinical applications of miR-22 in regulating malignant progression in human cancer (Review)

miRNAs (microRNAs) have been validated to play fateful roles in the occurrence and development of cancers by post-transcriptionally targeting 3′-untranslated regions of the downstream gene mRNAs to repress mRNA expression. Mounting investigations forcefully document that not only does miR-22 biologically impinge on the processes of senescence, energy supply, angiogenesis, EMT (epithelial-mesenchymal transition), proliferation, migration, invasion, metastasis and apoptosis, but also it genetically or epigenetically exerts dual (inhibitory/promoting cancer) effects in various cancers via CNAs (copy number alterations), SNPs (single nucleotide polymorphisms), methylation, acetylation and even more momentously hydroxymethylation. Additionally, miR-22 expression may fluctuate with cancer progression in the body fluids of cancer patients and miR-22 could amplify its inhibitory or promoting effects through partaking in positive or negative feedback loops and interplaying with many other related miRNAs in the cascade of events, making it possible for miR-22 to be a promising and complementary or even independent cancer biomarker in some cancers and engendering profound influences on the early diagnosis, therapeutics, supervising curative effects and prognosis.

Global Mapping of Traditional Chinese Medicine into Bioactivity Space and Pathways Annotation Improves Mechanistic Understanding and Discovers Relationships between Therapeutic Action (Sub)classes

Traditional Chinese medicine (TCM) still needs more scientific rationale to be proven for it to be accepted further in the West. We are now in the position to propose computational hypotheses for the mode-of-actions (MOAs) of 45 TCM therapeutic action (sub)classes from in silico target prediction algorithms, whose target was later annotated with Kyoto Encyclopedia of Genes and Genomes pathway, and to discover the relationship between them by generating a hierarchical clustering. The results of 10,749 TCM compounds showed 183 enriched targets and 99 enriched pathways from Estimation Score ≤ 0 and ≥ 5% of compounds/targets in a (sub)class. The MOA of a (sub)class was established from supporting literature. Overall, the most frequent top three enriched targets/pathways were immune-related targets such as tyrosine-protein phosphatase nonreceptor type 2 (PTPN2) and digestive system such as mineral absorption. We found two major protein families, G-protein coupled receptor (GPCR), and protein kinase family contributed to the diversity of the bioactivity space, while digestive system was consistently annotated pathway motif, which agreed with the important treatment principle of TCM, “the foundation of acquired constitution” that includes spleen and stomach. In short, the TCM (sub)classes, in many cases share similar targets/pathways despite having different indications.

Molecular mechanisms of microRNAs in regulating epithelial-mesenchymal transitions in human cancers

The epithelial-mesenchymal transition (EMT) provides a strong driving force in the progression of various human cancers and the development of chemoresistance. Recently, numbers of studies have demonstrated that microRNAs (miRNAs), by post-transcriptionally silencing EMT-related molecules, can promote or inhibit the EMT process and play pivotal roles in effectively manipulating the occurrence, development, invasion, and metastasis of cancers. MiRNAs can also control the EMT or be controlled by genetic modification and mutual regulation, especially negative feedback. Therefore, miRNAs can be viewed as either oncogenes or tumor suppressor genes to facilitate or retard the EMT, resulting in far-reaching impact on tumor metastasis and effective diagnosis, treatment, and prognosis.

Blocking TGF-β expression inhibits silica particle-induced epithelial-mesenchymal transition in human lung epithelial cells

The main characteristic of silicosis is irreversible fibrosis. Certain studies have shown that epithelial-mesenchymal transition (EMT) regulated by transforming growth factor-β (TGF-β) is involved in fibrosis. Thus, we suggest that TGF-β regulated EMT may play an important role in silicosis. In this study, we determined the expression of TGF-β-Smad2/3, EMT- and ECM-related markers in lung epithelial cells treated with silica particle by RT-PCR, western-blot and ELISA. In order to explore the role of TGF-β, we used TGF-β inhibitor in the cell model. We found that the cells lost the expression of epithelial phenotypic markers and acquired increased expression of mesenchymal cells markers with ECM deposition after treatment with silica particle. Moreover, the changes of EMT-related event was restricted in response to TGF-β inhibitor. These findings suggest that EMT is essentially involved in the pathogenesis of fibrosis induced by silica particles and down-regulating the TGF-β expression can inhibit the process of EMT.

Ethanol extract of Kilkyung-baeksan, a traditional herbal formula, induces G0/G1 cell cycle arrest in human lung cancer cell lines

Background

Despite current advances in diagnostics and medicines, the incidence of lung cancer is increasing and effective treatment is very challenging. Traditional herbal formulae as well as many herbal plant extracts have been recognized as attractive sources for novel multi-targeted therapy of cancer with minimal side effects.

Methods

The ethanol extract of Kilkyung-baeksan (EE-KKBS) and its component herbs were tested for their ability to inhibit cancer growth in several lung cancer cell lines. The effects of EE-KKBS and ethanol extract of Croton tiglium Linné seed (EE-CT) on cell cycle progression were measured by flow cytometric analysis using propidium iodide staining. Western blot analyses were performed to measure the expression profiles of proteins regulating cell cycle checkpoints.

Results

EE-KKBS inhibited the growth of lung cancer cells after 24–72 hours treatment. Lung cancer cells treated with either EE-KKBS or EE-CT showed strong G0/G1 cell cycle arrest. The expressions of p21 and p27, two key regulators of G1 cell cycle checkpoint, were significantly upregulated upon treatment with EE-KKBS and EE-CT.

Conclusion

EE-KKBS exerted its cytostatic activity through regulating G1 cell cycle checkpoint in lung cancer cells, and this activity is mainly mediated by one of its component herbs, seeds of Croton tiglium. Collectively, our data suggest that EE-KKBS could be a novel candidate for adjuvant therapy for lung cancer.

Epigenetic mechanisms in cancer: push and pull between kneaded erasers and fate writers

Research concerning the epigenome over the years has systematically and sequentially shown substantial development and we have moved from global inhibition of modifications of the epigenome toward identification and targeted therapy against tumor-specific epigenetic mechanisms. In accordance with this approach, several drugs with epigenetically modulating activity have received considerable attention and appreciation, and recently emerging scientific evidence is uncovering details of their mode of action. High-throughput technologies have considerably improved our existing understanding of tumor suppressors, oncogenes, and signaling pathways that are key drivers of cancer. In this review, we summarize the general epigenetic mechanisms in cancer, including: the post-translational modification of DNA methyltransferase and its mediated inactivation of Ras association domain family 1 isoform A, Sonic hedgehog signaling, Wnt signaling, Notch signaling, transforming growth factor signaling, and natural products with epigenetic modification ability. Moreover, we introduce the importance of nanomedicine for delivery of natural products with modulating ability to epigenetic machinery in cancer cells. Such in-depth and comprehensive knowledge regarding epigenetic dysregulation will be helpful in the upcoming era of molecular genomic pathology for both detection and treatment of cancer. Epigenetic information will also be helpful when nanotherapy is used for epigenetic modification.

Chemokine ligand 20 enhances progression of hepatocellular carcinoma via epithelial-mesenchymal transition

AIM: To identify the mechanisms of chemokine ligand 20 (CCL20)-induced hepatocellular carcinoma (HCC) metastasis and evaluate it as a prognostic marker.

METHODS: Expression of CCL20 was evaluated by immunohistochemistry in HCC tissues from 62 patients who underwent curative resection. The relationship between CCL20 expression and clinicopathologic features was analyzed. Univariate and multivariate analyses were performed to evaluate its predictive value for recurrence and survival of HCC patients. The expression levels of epithelial-mesenchymal transition (EMT)-and signaling pathway-related proteins were evaluated by Western blotting and immunocytochemistry. The effects of CCL20 on HCC cell proliferation and migration were analyzed by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenoltetrazolium bromide (MTT) and Transwell assays.

RESULTS: CCL20 immunoreactivity was detected in all 62 patient specimens. CCL20 expression was associated with preoperative alpha-fetoprotein level (P = 0.043), tumor size (P = 0.000), tumor number (P = 0.008), vascular invasion (P = 0.014), and tumor differentiation (P = 0.007). Patients with high CCL20 expression had poorer recurrence-free and overall survivals compared to those with low CCL20 expression (both P < 0.001). CCL20 induced EMT-like changes in HCC cells and increased their proliferation and migration ability (P < 0.05). Western blotting and immunofluorescence staining showed that CCL20 induced an EMT-like phenotype in HCC cells, and increased expression of phosphorylated AKT, β-catenin and vimentin, and decreased E-cadherin expression (P < 0.05). The correlation analysis revealed that high CCL20 expression in HCC tissue specimens was negatively correlated with E-cadherin expression (13.33%, 4/30), and positively correlated with vimentin (90.0%, 27/30), β-catenin (96.67%, 29/30) and p-AKT (76.67%, 23/30) expression.

CONCLUSION: CCL20 expression is associated with HCC recurrence and patient survival and promotes HCC cell proliferation and migration by inducing EMT-like changes via PI3K/AKT and Wnt/β-catenin pathways.