Ursolic Acid Attenuates TGF-β1-Induced Epithelial-Mesenchymal Transition in NSCLC by Targeting Integrin αVβ5/MMPs Signaling

Asiaticoside Inhibits Growth and Metastasis in Non-Small Cell Lung Cancer by Disrupting EMT via Wnt/β-Catenin Pathway

Non-small cell lung cancer (NSCLC) is the primary inducer of cancer-related death worldwide. Asiaticoside (ATS) is a triterpenoid saponin that has been indicated to possess an antitumor activity in several malignancies. Nonetheless, its detailed functions in NSCLC remain unclarified. In this study, NSCLC cells were exposed to various doses of ATS. Functional experiments were employed to estimate the ATS effect on NSCLC cell behaviors. Western blotting was implemented for protein expression evaluation. A xenograft mouse model was established to assess the ATS effect on NSCLC in vivo. The results showed that ATS restrained NSCLC cell proliferation, cell cycle progression, migration, and invasiveness. ATS reversed TGF-β-induced promotion in epithelial-mesenchymal transition (EMT). Mechanistically, ATS inhibited Wnt/β-catenin signaling in NSCLC. Upregulating β-catenin restored ATS-mediated suppression of NSCLC cell aggressiveness. Moreover, ATS administration repressed tumorigenesis in tumor-bearing mice. In conclusion, ATS represses growth and metastasis in NSCLC by blocking EMT via the inhibition of Wnt/β-catenin signaling.

Connexin 43 controls metastatic behavior in triple negative breast cancer through TGFβ1-Smad3-intergin αV signaling axis Based on optical image diagnosis

Abnormal expression of connexin 43 (Cx43) contributes to the development and progression of cancer. However, its regulation is complex and dependent on the environment. The expression of Cx43 in triple-negative cancer lesions was analyzed by immunohistochemistry and optical coherence tomography using experimental models and clinical samples. The model of TGFβ1-SMad3-in-αv signal axis was established and verified by experiments. The results show that Cx43 plays a key role in the regulation of triple-negative cancer metastasis. In vivo, over-expressed Cx43 decreased tumor volume and inhibited ITGαV, TGF-β1, Smad3 and N-cadherin expressions, but enhanced the E-cadherin. Cx43 had the lowest expression in the TNBC samples, especially in lymph node metastatic TNBC patients and had a negative correlation with ITG alpha V, TGF-β1 and Smad3.The study demonstrated Cx43 controlled metastatic behavior through TGF-β1 -Smad3-ITG αV signaling axis in MDA-MB-231 cells, providing evidence for Cx43's function in TNBC. The optical image diagnosis method can realize the identification and quantitative evaluation of early cancer triple negative, and provide a new strategy and means for the treatment of cancer triple negative.

The Nexus of Inflammation-Induced Epithelial-Mesenchymal Transition and Lung Cancer Progression: A Roadmap to Pentacyclic Triterpenoid-Based Therapies

Lung cancer is the leading cause of cancer-related death worldwide. Its high mortality is partly due to chronic inflammation that accompanies the disease and stimulates cancer progression. In this review, we analyzed recent studies and highlighted the role of the epithelial-mesenchymal transition (EMT) as a link between inflammation and lung cancer. In the inflammatory tumor microenvironment (iTME), fibroblasts, macrophages, granulocytes, and lymphocytes produce inflammatory mediators, some of which can induce EMT. This leads to increased invasiveness of tumor cells and self-renewal of cancer stem cells (CSCs), which are associated with metastasis and tumor recurrence, respectively. Based on published data, we propose that inflammation-induced EMT may be a potential therapeutic target for the treatment of lung cancer. This prospect is partially realized in the development of EMT inhibitors based on pentacyclic triterpenoids (PTs), described in the second part of our study. PTs reduce the metastatic potential and stemness of tumor cells, making PTs promising candidates for lung cancer therapy. We emphasize that the high diversity of molecular mechanisms underlying inflammation-induced EMT far exceeds those that have been implicated in drug development. Therefore, analysis of information on the relationship between the iTME and EMT is of great interest and may provide ideas for novel treatment approaches for lung cancer.

Targeting Cell Signaling Pathways in Lung Cancer by Bioactive Phytocompounds

Lung cancer is a heterogeneous group of malignancies with high incidence worldwide. It is the most frequently occurring cancer in men and the second most common in women. Due to its frequent diagnosis and variable response to treatment, lung cancer was reported as the top cause of cancer-related deaths worldwide in 2020. Many aberrant signaling cascades are implicated in the pathogenesis of lung cancer, including those involved in apoptosis (B cell lymphoma protein, Bcl-2-associated X protein, first apoptosis signal ligand), growth inhibition (tumor suppressor protein or gene and serine/threonine kinase 11), and growth promotion (epidermal growth factor receptor/proto-oncogenes/phosphatidylinositol-3 kinase). Accordingly, these pathways and their signaling molecules have become promising targets for chemopreventive and chemotherapeutic agents. Recent research provides compelling evidence for the use of plant-based compounds, known collectively as phytochemicals, as anticancer agents. This review discusses major contributing signaling pathways involved in the pathophysiology of lung cancer, as well as currently available treatments and prospective drug candidates. The anticancer potential of naturally occurring bioactive compounds in the context of lung cancer is also discussed, with critical analysis of their mechanistic actions presented by preclinical and clinical studies.

The effectiveness of blood-activating and stasis-transforming traditional Chinese medicines (BAST) in lung cancer progression-a comprehensive review

ETHNOPHARMACOLOGICAL RELEVANCE

Blood-activating and stasis-transforming traditional Chinese medicines (BAST) are a class of herbs that have the effect of dilating blood vessels and dispersing stagnation. Modern pharmaceutical research has demonstrated that they are capable of improving hemodynamics and micro-flow, resist thrombosis and promote blood flow. BAST contain numerous active ingredients, which can theoretically regulate multiple targets at the same time and have a wide range of pharmacological effects in the treatment of diseases including human cancers. Clinically, BAST have minimal side effects and can be used in combination with Western medicine to improve patients' quality of life, lessen adverse effects and minimize the risk of recurrence and metastasis of cancers.

AIM OF THE REVIEW

We aimed to summarize the research progression of BAST on lung cancer in the past five years and present a prospect for the future. Particularly, this review further analyzes the effects and molecular mechanisms that BAST inhibit the invasion and metastasis of lung cancer.

MATERIALS AND METHODS

Relevant studies about BSAT were collected from PubMed and Web of science.

RESULTS

Lung cancer is one of the malignant tumors with the highest mortality rate. Most patients with lung cancer are diagnosed at an advanced stage and are highly susceptible to metastasis. Recent studies have shown that BAST, a class of traditional Chinese medicine (TCM) with the function of opening veins and dispersing blood stasis, significantly improve hemodynamics and microcirculation, prevent thrombosis and promote blood flow, and thereby inhibiting the invasion and metastasis of lung cancer. In the current review, we analyzed 51 active ingredients extracted from BAST. It was found that BAST and their active ingredients contribute to the prevention of invasion and metastasis of lung cancer through multiple mechanisms, such as regulation of EMT process, specific signaling pathway and metastasis-related genes, tumor blood vessel formation, immune microenvironment and inflammatory response of tumors.

CONCLUSIONS

BSAT and its active ingredients have showed promising anticancer activity and significantly inhibit the invasion and metastasis of lung cancer. A growing number of studies have realized their potential clinical significance in the therapy of lung cancer, which will provide substantial evidences for the development of new TCM for lung cancer therapy.

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

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

Natural Products as Anticancer Agents: Current Status and Future Perspectives

Natural products have been an invaluable and useful source of anticancer agents over the years. Several compounds have been synthesized from natural products by modifying their structures or by using naturally occurring compounds as building blocks in the synthesis of these compounds for various purposes in different fields, such as biology, medicine, and engineering. Multiple modern and costly treatments have been applied to combat cancer and limit its lethality, but the results are not significantly refreshing. Natural products, which are a significant source of new therapeutic drugs, are currently being investigated as potential cytotoxic agents and have shown a positive trend in preclinical research and have prompted numerous innovative strategies in order to combat cancer and expedite the clinical research. Natural products are becoming increasingly important for drug discovery due to their high molecular diversity and novel biofunctionality. Furthermore, natural products can provide superior efficacy and safety due to their unique molecular properties. The objective of the current review is to provide an overview of the emergence of natural products for the treatment and prevention of cancer, such as chemosensitizers, immunotherapeutics, combinatorial therapies with other anticancer drugs, novel formulations of natural products, and the molecular mechanisms underlying their anticancer properties.

Evidence of the Beneficial Effects of Ursolic Acid against Lung Cancer

Lung cancer is the leading cause of cancer-related deaths globally. Despite current treatment approaches that include surgery, chemotherapy, radiation and immunotherapies, lung cancer accounted for 1.79 million deaths worldwide in 2020, emphasizing the urgent need to find novel agents and approaches for more effective treatment. Traditionally, chemicals derived from plants, such as paclitaxel and docetaxel, have been used in cancer treatment, and in recent years, research has focused on finding other plant-derived chemicals that can be used in the fight against lung cancer. Ursolic acid is a polyphenol found in high concentrations in cranberries and other fruits and has been demonstrated to have anti-inflammatory, antioxidant and anticancer properties. In this review, we summarize recent research examining the effects of ursolic acid and its derivatives on lung cancer. Data from in vitro cell culture and in vivo animal studies show potent anticancer effects of ursolic acid and indicate the need for clinical studies.

Inhibitory effects of total triterpenoids isolated from the Hedyotis diffusa willd on H1975 cells

It is estimated that non-small-cell lung cancer (NSCLC) is responsible for 80% of human deaths related to lung cancer worldwide. Currently, it has been discovered that two transcription factors. Nuclear factor-κB (NF-κB) and Signal transducer and activator of transcription 3 (STAT3) were the main factors affecting inflammation and cancer, and their activation promoted lung cancer cell proliferation. Hedyotis diffusa Willd. (H. diffusa) is an herbal Chinese medicine, which has always been used for the treatment of malignant tumors in clinical. Previous research found that H. diffusa could inhibit the proliferation of H1975 cells, but the specific mechanisms remain elusive. We investigated the effects of total triterpenes extracted from H. diffusa (TTH) on the migration, proliferation and apoptosis of H1975 cells. Cell-cycle and immunofluorescence analysis showed that TTH could block H1975 cells at G0/G1 phase and induce apoptosis of experimental cells. The protein levels of Bcl-2 were decreased, while the levels of pro-apoptotic Bax were increased. In addition, TTH could also inhibit the migration of H1975 cells through downregulated MMP-2 and MMP-9 and upregulated TIMP-2. Further research found that the level of phospho-STAT3 was significantly decreased after administration of TTH. And protein expression level of NF-κB in nucleus was decreased after TTH treatment, while NF-κB in cytoplasm increased. These results suggested that TTH could inhibit the proliferation and migration of H1975 cells, and also could induce cell apoptosis. These effects were closely connected to the activation of NF-κB and the phosphorylation of STAT3.

Antitumor Effects of Natural Bioactive Ursolic Acid in Embryonic Cancer Stem Cells

Embryonic cancer cells (CSCs) could cause different types of cancer, a skill that makes them even more dangerous than other cancer cells. Identifying CSCs using natural products is a good option as it inhibits the recurrence of cancer with moderate various effects. Ursolic acid (UA) is a pentacyclic triterpenoid extracted from fruit and herbal remedies and has known anticancer functions against various cancer cells. However, its potential against CSCs remains uncertain. This study was planned to examine the induction of cell apoptosis by the UA. For cell signaling studies, we performed experiments, which are real-time qPCR and immunoblotting. Also, various cellular processes were analyzed using flow cytometry. The results raised a barrier to cell proliferation by the UA in NTERA-2 and NCCIT cells. Morphological studies also confirmed the UA's ability to cause cell death in embryonic CSCs. Examination of cell death importation showed that the UA formed the expression of the iNOS and thus the cell generation and mitochondrial reactive oxygen generation, which created a reaction to cellular DNA damage by raising the protein levels of phospho-histone ATR and ATM. In addition, the UA created the binding of the G0/G1 cell cycle to NTERA-2 and NCCIT cells, improved the expression levels of p21 and p27, and reduced the expression levels of CDK4, cyclin D1, and cyclin E, confirming the UA's ability to initiate cell cycle arrest. Finally, the UA created an internal mechanism of apoptosis in the embryonic CSC using BAX and cytochrome c regulation as well as the regulation of BCL-xL and BCL-2 proteins. Therefore, UA could be the best candidate for targeting CSCs and thus suppressing the emergence of cancer.

Triterpenoid ursolic acid drives metabolic rewiring and epigenetic reprogramming in treatment/prevention of human prostate cancer

Ursolic acid (UA) is a triterpenoid phytochemical with a strong anticancer effect. The metabolic rewiring, epigenetic reprogramming, and chemopreventive effect of UA in prostate cancer (PCa) remain unknown. Herein, we investigated the efficacy of UA in PCa xenograft, and its biological effects on cellular metabolism, DNA methylation, and transcriptomic using multi-omics approaches. The metabolomics was quantified by liquid-chromatography-mass spectrometry (LC-MS) while epigenomic CpG methylation in parallel with transcriptomic gene expression was studied by next-generation sequencing technologies. UA administration attenuated the growth of transplanted human VCaP-Luc cells in immunodeficient mice. UA regulated several cellular metabolites and metabolism-related signaling pathways including S-adenosylmethionine (SAM), methionine, glucose 6-phosphate, CDP-choline, phosphatidylcholine biosynthesis, glycolysis, and nucleotide sugars metabolism. RNA-seq analyses revealed UA regulated several signaling pathways, including CXCR4 signaling, cancer metastasis signaling, and NRF2-mediated oxidative stress response. Epigenetic reprogramming study with DNA Methyl-seq uncovered a list of differentially methylated regions (DMRs) associated with UA treatment. Transcriptome-DNA methylome correlative analysis uncovered a list of genes, of which changes in gene expression correlated with the promoter CpG methylation status. Altogether, our results suggest that UA regulates metabolic rewiring of metabolism including SAM potentially driving epigenetic CpG methylation reprogramming, and transcriptomic signaling resulting in the overall anticancer chemopreventive effect.

Therapeutic Effects and Molecular Mechanisms of Bioactive Compounds Against Respiratory Diseases: Traditional Chinese Medicine Theory and High-Frequency Use

Respiratory diseases, especially the pandemic of respiratory infectious diseases and refractory chronic lung diseases, remain a key clinical issue and research hot spot due to their high prevalence rates and poor prognosis. In this review, we aimed to summarize the recent advances in the therapeutic effects and molecular mechanisms of key common bioactive compounds from Chinese herbal medicine. Based on the theories of traditional Chinese medicine related to lung diseases, we searched several electronic databases to determine the high-frequency Chinese medicines in clinical application. The active compounds and metabolites from the selected medicines were identified using the Traditional Chinese Medicine Systems Pharmacology Database (TCMSP) by analyzing oral bioavailability and drug similarity index. Then, the pharmacological effects and molecular mechanisms of the selected bioactive compounds in the viral and bacterial infections, inflammation, acute lung injury (ALI), chronic obstructive pulmonary disease (COPD), pulmonary fibrosis, asthma, and lung cancer were summarized. We found that 31 bioactive compounds from the selected 10 common Chinese herbs, such as epigallocatechin-3-gallate (EGCG), kaempferol, isorhamnetin, quercetin, and β-sitosterol, can mainly regulate NF-κB, Nrf2/HO-1, NLRP3, TGF-β/Smad, MAPK, and PI3K/Akt/mTOR pathways to inhibit infection, inflammation, extracellular matrix deposition, and tumor growth in a series of lung-related diseases. This review provides novel perspectives on the preclinical study and clinical application of Chinese herbal medicines and their bioactive compounds against respiratory diseases.

Nanoformulations of Ursolic Acid: A Modern Natural Anticancer Molecule

Background: Ursolic acid (UA) is a natural pentacyclic triterpene derived from fruit, herb, and other plants. UA can act on molecular targets of various signaling pathways, inhibit the growth of cancer cells, promote cycle stagnation, and induce apoptosis, thereby exerting anticancer activity. However, its poor water-solubility, low intestinal mucosal absorption, and low bioavailability restrict its clinical application. In order to overcome these deficiencies, nanotechnology, has been applied to the pharmacological study of UA.

Objective: In this review, we focused on the absorption, distribution, and elimination pharmacokinetics of UA in vivo, as well as on the research progress in various UA nanoformulations, in the hope of providing reference information for the research on the anticancer activity of UA.

Methods: Relevant research articles on Pubmed and Web of Science in recent years were searched selectively by using the keywords and subheadings, and were summarized systematically.

Key finding: The improvement of the antitumor ability of the UA nanoformulations is mainly due to the improvement of the bioavailability and the enhancement of the targeting ability of the UA molecules. UA nanoformulations can even be combined with computational imaging technology for monitoring or diagnosis.

Conclusion: Currently, a variety of UA nanoformulations, such as micelles, liposomes, and nanoparticles, which can increase the solubility and bioactivity of UA, while promoting the accumulation of UA in tumor tissues, have been prepared. Although the research of UA in the nanofield has made great progress, there is still a long way to go before the clinical application of UA nanoformulations.

Antitumor Effects of Ursolic Acid through Mediating the Inhibition of STAT3/PD-L1 Signaling in Non-Small Cell Lung Cancer Cells

Targeted therapy based on natural compounds is one of the best approaches against non-small cell lung cancer. Ursolic acid (UA), a pentacyclic triterpenoid derived from medicinal herbs, has anticancer activity. Studies on the molecular mechanism underlying UA’s anticancer activity are ongoing. Here, we demonstrated UA’s anticancer activity and the underlying signaling mechanisms. We used Western blotting and real-time quantitative polymerase chain reaction for molecular signaling analysis. We also used in vitro angiogenesis, wound healing, and invasion assays to study UA’s anticancer activity. In addition, we used tumorsphere formation and chromatin immunoprecipitation assays for binding studies. The results showed that UA inhibited the proliferation of A549 and H460 cells in a concentration-dependent manner. UA exerted anticancer effects by inducing G0/G1 cell cycle arrest and apoptosis. It also inhibited tumor angiogenesis, migration, invasion, and tumorsphere formation. The molecular mechanism underlying UA activity involves UA’s binding to epidermal growth factor receptor (EGFR), reducing the level of phospho-EGFR, and thus inhibiting the downstream JAK2/STAT3 pathway. Furthermore, UA reduced the expressions of vascular endothelial growth factor (VEGF), metalloproteinases (MMPs) and programmed death ligand-1 (PD-L1), as well as the formation of STAT3/MMP2 and STAT3/PD-L1 complexes. Altogether, UA exhibits anticancer activities by inhibiting MMP2 and PD-L1 expression through EGFR/JAK2/STAT3 signaling.

Cyano Enone-Bearing Triterpenoid Soloxolone Methyl Inhibits Epithelial-Mesenchymal Transition of Human Lung Adenocarcinoma Cells In Vitro and Metastasis of Murine Melanoma In Vivo

Introduction of α-cyano α,β-unsaturated carbonyl moiety into natural cyclic compounds markedly improves their bioactivities, including inhibitory potential against tumor growth and metastasis. Previously, we showed that cyano enone-bearing derivatives of 18βH-glycyrrhetinic (GA) and deoxycholic acids displayed marked cytotoxicity in different tumor cell lines. Moreover, GA derivative soloxolone methyl (SM) was found to induce ER stress and apoptosis in tumor cells in vitro and inhibit growth of carcinoma Krebs-2 in vivo. In this work, we studied the effects of these compounds used in non-toxic dosage on the processes associated with metastatic potential of tumor cells. Performed screening revealed SM as a hit compound, which inhibits motility of murine melanoma B16 and human lung adenocarcinoma A549 cells and significantly suppresses colony formation of A549 cells. Further study showed that SM effectively blocked transforming growth factor β (TGF-β)-induced epithelial-mesenchymal transition (EMT) of A549 cells: namely, inhibited TGF-β-stimulated motility and invasion of tumor cells as well as loss of their epithelial characteristics, such as, an acquisition of spindle-like phenotype, up- and down-regulation of mesenchymal (vimentin, fibronectin) and epithelial (E-cadherin, zona occludens-1 (ZO-1)) markers, respectively. Network pharmacology analysis with subsequent verification by molecular modeling revealed that matrix metalloproteinases MMP-2/-9 and c-Jun N-terminal protein kinase 1 (JNK1) can be considered as hypothetical primary targets of SM, mediating its marked anti-EMT activity. The inhibitory effect of SM on EMT revealed in vitro was further confirmed in a metastatic model of murine B16 melanoma: SM was found to effectively block metastatic dissemination of melanoma B16 cells in vivo, increase expression of E-cadherin and suppress expression of MMP-9 in lung metastatic foci. Altogether, our data provided valuable information for a better understanding of the antitumor activity of cyano enone-bearing semisynthetic compounds and revealed SM as a promising anti-metastatic drug candidate.

Ursolic acid inhibits the invasiveness of A498 cells via NLRP3 inflammasome activation

Renal cell cancer is a common malignant tumor of the urinary system. Ursolic acid (UA) serves an important antitumor role in certain types of cancer, such as lung cancer, breast cancer and hepatocellular carcinoma; however, to the best of our knowledge, the effect of UA on renal cancer has not yet been investigated. In the present study, A498 cells were treated with different concentrations of UA for 12, 24 and 48 h, and then MCC950, an inhibitor of the NLR family pyrin domain-containing 3 (NLRP3) receptor, was added to block NLRP3 signaling. The proliferation of A498 cells was analyzed using an MTS assay and invasiveness was analyzed using a Transwell assay. The expression levels of NLRP3, cleaved caspase-1, IL-1β and MMP-2 were detected using western blotting. The present results demonstrated that the invasiveness of A498 cells was significantly decreased following UA treatment (P<0.05), while expression levels of NLRP3, cleaved caspase-1 and IL-1β were significantly increased, and MMP-2 expression was decreased following UA stimulation (P<0.05). This was reversed by MCC950 treatment (P<0.05), with the exception of NLRP3. In conclusion, the present results indicated that UA exposure decreased the proliferation and invasiveness of A498 cells. Additionally, UA exposure significantly decreased MMP-2 production and induced the activation of NLRP3 inflammasome, which was reversed by MCC950 treatment, indicating that NLRP3 activation may be involved in UA inhibition of A498 cell invasiveness.

Connexin 43 Modulates the Cellular Resistance to Paclitaxel via Targeting β-Tubulin in Triple-Negative Breast Cancer

Background

Triple-negative breast cancer has become an intricate part and hotspot in the clinical and experimental research. Connexins, serving as functional proteins in gap junctions, play an important role in tumorigenesis, cell proliferation and metastasis.

Methods

We constructed and employed the Connexin 43 (Cx43) overexpression lentiviral vectors and Cx43 siRNA in paclitaxel-treated MDA-MB-231 cells. We performed the experiments of clonal formation and flow cytometry to gauge the effect of paclitaxel on cellular behaviors and immunofluorescence and subsequent quantitative RT-PCR and Western blot to examine the expression of genes and corresponding proteins. Experiments of scrape loading/dye transfer were utilized to explore the gap junctions. The targets of Cx43 were identified via the experiments of co-immunoprecipitation (Co-IP), GST pull-down assays and proximal ligation assay (PLA).

Results

The results showed that Cx43 hindered cell proliferation and promoted apoptosis in the paclitaxel-treated MDA-MB-231 cells. Overexpressed Cx43 suppressed the expression of resistance genes such as BRCP, Txr-1, α-tubulin and β-tubulin and promoted the expression of apoptosis gene as TSP-1 and Bcl-2. Cx43 was also positively related to ITGα9 and negatively related to ITGαV and ITGα11. The gap junctions altered magnificently under different expressions of Cx43, which indicated that Cx43 could promote the number of intercellular gap junctions. The immunofluorescent experiment revealed that both of Cx43 and β-tubulin were mainly localized in the cytoplasm. The assays of Co-IP and GST pull-down demonstrated that there existed a direct interaction between Cx43 and β-tubulin. Furthermore, the result of PLA also showed that Cx43 interacts with β-tubulin in MDA-MB-231 cells.

Conclusion

Overexpression of Cx43 could modulate the cellular resistance to paclitaxel via targeting β-tubulin in triple-negative breast cancer.

Vimentin Intermediate Filaments as Potential Target for Cancer Treatment

Intermediate filaments constitute the third component of the cellular skeleton. Unlike actin and microtubule cytoskeletons, the intermediate filaments are composed of a wide variety of structurally related proteins showing distinct expression patterns in tissues and cell types. Changes in the expression patterns of intermediate filaments are often associated with cancer progression; in particular with phenotypes leading to increased cellular migration and invasion. In this review we will describe the role of vimentin intermediate filaments in cancer cell migration, cell adhesion structures, and metastasis formation. The potential for targeting vimentin in cancer treatment and the development of drugs targeting vimentin will be reviewed.

Synergistic Effect of Network-Based Multicomponent Drugs: An Investigation on the Treatment of Non-Small-Cell Lung Cancer with Compound Liuju Formula

Lung cancer is the most common cause of cancer death with high morbidity and mortality, which non-small-cell lung cancer (NSCLC) accounting for the majority. Traditional Chinese Medicine (TCM) is effective in the treatment of complex diseases, especially cancer. However, TCM is still in the conceptual stage. The interaction between different components remains unknown due to its multicomponent and multitarget characteristics. In this study, compound Liuju formula was taken as an example to isolate compounds with synergistic biological activity through systems pharmacology strategy. Through pharmacokinetic evaluation, 37 potentially active compounds were screened out. Meanwhile, 116 targets of these compounds were obtained by combing with the target prediction model. Through network analysis, we found that multicomponent drugs can present a synergistic effect through regulating inflammatory signaling pathway, invasion pathway, proliferation, and apoptosis pathway. Finally, it was confirmed that the bioactive compounds of compound Liuju formula have not only a killing effect on NSCLC tumor cells but also a synergistic effect on inhibiting the secretion of correlative inflammatory mediators, including TNF-α and IL-1β. The systems pharmacology method was applied in this study, which provides a new direction for analyzing the mechanism of TCM.

Ursonic acid exerts inhibitory effects on matrix metalloproteinases via ERK signaling pathway

Ursonic acid is a pentacyclic triterpenoid compound that can be extracted from Ziziphus jujuba Mill., a traditional medicine. Matrix metalloproteinases (MMPs) are involved in cancer metastasis and skin aging. Regulation of various MMPs is closely associated with mitogen-activated protein kinases (MAPKs), including ERK, p38, and JNK MAPKs. In this study, we investigated the possibility of ursonic acid as an anti-cancer/anti-skin aging agent targeting MMPs. Cytotoxic effects of ursonic acid were analyzed by cell counting kit-8 (CCK-8) assay. Invasive abilities of ursonic acid-treated A549 and H1299 non-small cell lung cancer (NSCLC) cells were tested with Boyden chamber assay. Effects of ursonic acid on MMPs were analyzed by zymography assays and quantitative real time polymerase chain reaction (qRT-PCR). We also conducted flow cytometry and western blot analysis to elucidate the mechanisms of MMP regulation by ursonic acid. Our results revealed that ursonic acid inhibited transcriptional expression of gelatinases (MMP-2 and MMP-9) via inhibition of ERK and CREB signaling pathways in NSCLC cells. Moreover, ursonic acid reduced mRNA levels of collagenase (MMP-1) via suppression of ERK and c-Fos signaling pathways in HaCaT keratinocytes. These results suggest that ursonic acid could be a potential candidate for development of an effective novel anti-cancer and anti-wrinkle agent.

Ursolic Acid Suppresses Cholesterol Biosynthesis and Exerts Anti-Cancer Effects in Hepatocellular Carcinoma Cells

Abnormally upregulated cholesterol and lipid metabolism, observed commonly in multiple cancer types, contributes to cancer development and progression through the activation of oncogenic growth signaling pathways. Although accumulating evidence has shown the preventive and therapeutic benefits of cholesterol-lowering drugs for cancer management, the development of cholesterol-lowering drugs is needed for treatment of cancer as well as metabolism-related chronic diseases. Ursolic acid (UA), a natural pentacyclic terpenoid, suppresses cancer growth and metastasis, but the precise underlying molecular mechanism for its anti-cancer effects is poorly understood. Here, using sterol regulatory element (SRE)-luciferase assay-based screening on a library of 502 natural compounds, this study found that UA activates sterol regulatory element-binding protein 2 (SREBP2). The expression of cholesterol biosynthesis-related genes and enzymes increased in UA-treated hepatocellular carcinoma (HCC) cells. The UA increased cell cycle arrest and apoptotic death in HCC cells and reduced the activation of oncogenic growth signaling factors, all of which was significantly reversed by cholesterol supplementation. As cholesterol supplementation successfully reversed UA-induced attenuation of growth in HCC cells, it indicated that UA suppresses HCC cells growth through its cholesterol-lowering effect. Overall, these results suggested that UA is a promising cholesterol-lowering nutraceutical for the prevention and treatment of patients with HCC and cholesterol-related chronic diseases.

Ursolic acid suppresses the invasive potential of colorectal cancer cells by regulating the TGF-β1/ZEB1/miR-200c signaling pathway

Ursolic acid (UA) is a biologically active compound, commonly used in traditional Chinese medicine (TCM). It has been reported to exhibit strong anticancer properties against a variety of cancers. Our previous studies showed that UA promoted apoptosis in colorectal cancer (CRC) cells and inhibited cellular proliferation and angiogenesis. However, the effect and underlying molecular mechanism of UA in CRC progression remain unclear. In the present study, the role of UA in suppressing the migration and invasion of human colon cancer HCT116 and HCT-8 cells was investigated, using Transwell assays. In addition, to evaluate whether the anticancer properties of UA were mediated by the regulation of a double-negative feedback loop consisting of the transforming growth factor-β1 (TGF-β1)/zinc finger E-box-binding homeobox (ZEB1) pathway and microRNA (miR)-200a/b/c, reverse transcription-quantitative PCR and western blot analysis were performed. The results indicated that UA treatment significantly suppressed cellular growth, migration and invasion in HCT116 and HCT-8 cells in a dose-dependent manner. Furthermore, following UA treatment, several crucial mediators of the TGF-β1 signaling pathway, including TGF-β1, phosphorylated (p)-Smad2/3, p-focal adhesion kinase and ZEB1, were significantly downregulated in the HCT116 and HCT-8 cell lines compared with the control group. Furthermore, the ratio of N-cadherin/E-cadherin, two proteins directly downstream of the TGF-β1 signaling pathway, was found to be downregulated in UA treated CRC cells. Finally, UA significantly upregulated miR200a/b/c, with miR-200c exhibiting the highest increase in expression levels following UA treatment. Collectively, the present study suggested that inhibition of CRC cell invasion by UA occurred via regulation of the TGF-β1/ZEB1/miR-200c signaling network, which may be one of the mechanisms by which UA appears to be an effective therapeutic agent against colon cancer.

Ursolic Acid Inhibits Tumor Growth via Epithelial-to-Mesenchymal Transition in Colorectal Cancer Cells

Ursolic acid (UA), a natural pentacyclic triterpenoid, is a promising compound for cancer prevention and therapy. However, its mechanisms of action have not been well elucidated in colorectal cancer cells. Here, using cultured human colon cancer cell lines SW620 and HCT116, this assay demonstrates that UA reduces cell viability, inhibits cell clone formation, and induces caspase-3 mediated apoptosis. Additional experiments show that UA inhibits cell migration and epithelial-mesenchymal transition (EMT), including E-cadherin, Vimentin, Integrin, Twist, and Zeb1 biomakers. These results suggest that UA inhibits cell proliferation, invasion, and metastasis in colorectal cancer cells by affecting mechanisms that regulate EMT. Taken together, the results suggested that the anti-proliferation and anti-metastasis activities of UA was through EMT inhibition in colorectal cancer.