Scutellarin inhibits hypoxia-induced epithelial-mesenchymal transition in bladder cancer cells

Exploring the roles and molecular mechanisms of RNA binding proteins in the sorting of noncoding RNAs into exosomes during tumor progression

BACKGROUND

RNA binding proteins (RBPs) play a role in sorting non-coding RNAs (ncRNAs) into exosomes. These ncRNAs, carried by exosomes, are involved in regulating various aspects of tumor progression, including metastasis, angiogenesis, control of the tumor microenvironment, and drug resistance. Recent studies have emphasized the importance of the RBP-ncRNA-exosome mechanism in tumor regulation.

AIM OF REVIEW

This comprehensive review aims to explore the RBP-ncRNA-exosome mechanism and its influence on tumor development. By understanding this intricate mechanism provides novel insights into tumor regulation and may lead to innovative treatment strategies in the future.

KEY SCIENTIFIC CONCEPTS OF REVIEW

The review discusses the formation of exosomes and the complex relationships among RBPs, ncRNAs, and exosomes. The RBP-ncRNA-exosome mechanism is shown to affect various aspects of tumor biology, including metastasis, multidrug resistance, angiogenesis, the immunosuppressive microenvironment, and tumor progression. Tumor development relies on the transmission of information between cells, with RBPs selectively mediating sorting of ncRNAs into exosomes through various mechanisms, which in turn carry ncRNAs to regulate RBPs. The review also provides an overview of potential therapeutic strategies, such as targeted drug discovery and genetic engineering for modifying therapeutic exosomes, which hold great promise for improving cancer treatment.

Scutellarin, a flavonoid compound from Scutellaria barbata, suppresses growth of breast cancer stem cells in vitro and in tumor-bearing mice

BACKGROUND

Scutellaria barbata D. Don (SB), commonly known as Ban Zhi Lian and firstly documented by Shigong Chen, is a dried whole plant that has been studied for its therapeutic effects on breast cancer, colon cancer, and prostate cancer. Among its various compounds, scutellarin (SCU) has been demonstrated with anti-tumor effects.

PURPOSE

This study aimed to evaluate the effects of SB water extract (SBW) and scutellarin on breast cancer stem cells (BCSCs), and to investigate their potential therapeutic effects on breast tumors in mice.

METHODS

BCSCs were enriched from human breast cancer cells (MDA-MB-231 and MDA-MB-361) and their characteristics were analyzed. The effects of varying concentrations of SBW and scutellarin on cell viability, proliferation, self-renewal, and migration abilities were studied, along with the underlying mechanisms. The in vivo anti-tumor effects of scutellarin were further evaluated in SCID/NOD mice. Firstly, mice were inoculated with naïve BCSCs and subjected to treatment with scutellarin or vehicle. Secondly, BCSCs were pre-treated with scutellarin or vehicle prior to inoculation into mice.

RESULTS

The derived BCSCs expressed CD44, CD133 and ALDH1, but not CD24, indicating that BCSCs have been successfully induced from both MDA-MB-231 and MDA-MB-361 cells. Both SBW and scutellarin reduced the viability, proliferation, sphere and colony formation, and migration of BCSCs. In mice with tumors derived from naïve BCSCs, scutellarin significantly reduced tumor growth, expression of proliferative (Ki67) and stem cell markers (CD44), and lung metastasis. In addition, pre-treatment with scutellarin also slowed tumor growth. Western blot results suggested the involvement of Wnt/β-catenin, NF-κB, and PTEN/Akt/mTOR signaling pathways underlying the inhibitory effects of scutellarin.

CONCLUSION

Our study demonstrated for the first time that both SB water extract and scutellarin could reduce the proliferation and migration of BCSCs in vitro. Scutellarin was shown to possess novel inhibitory activities in BCSCs progression. These findings suggest that Scutellaria barbata water extract, in particular, scutellarin, may have potential to be further developed as an adjuvant therapy for reducing breast cancer recurrence.

Scutellarin Alleviates Ovalbumin-Induced Airway Remodeling in Mice and TGF-β-Induced Pro-fibrotic Phenotype in Human Bronchial Epithelial Cells via MAPK and Smad2/3 Signaling Pathways

Asthma is a chronic inflammatory disease characterized by airway hyperresponsiveness (AHR), inflammation, and remodeling. Epithelial-mesenchymal transition (EMT) is an essential player in these alterations. Scutellarin is isolated from Erigeron breviscapus. Its vascular relaxative, myocardial protective, and anti-inflammatory effects have been well established. This study was designed to detect the biological roles of scutellarin in asthma and its related mechanisms. The asthma-like conditions were induced by ovalbumin challenges. The airway resistance and dynamic compliance were recorded as the results of AHR. Bronchoalveolar lavage fluid (BALF) was collected and processed for differential cell counting. Hematoxylin and eosin staining, periodic acid-Schiff staining, and Masson staining were conducted to examine histopathological changes. The levels of asthma-related cytokines were measured by enzyme-linked immunosorbent assay. For in vitro analysis, the 16HBE cells were stimulated with 10 ng/mL transforming growth beta-1 (TGF-β1). Cell migration was estimated by Transwell assays and wound healing assays. E-cadherin, N-cadherin, and α-smooth muscle actin (α-SMA) were analyzed by western blotting, real-time quantitative polymerase chain reaction, immunofluorescence staining, and immunohistochemistry staining. The underlying mechanisms of the mitogen-activated protein kinase (MAPK) and Smad pathways were investigated by western blotting. In an ovalbumin-induced asthmatic mouse model, scutellarin suppressed inflammation and inflammatory cell infiltration into the lungs and attenuated AHR and airway remodeling. Additionally, scutellarin inhibited airway EMT (upregulated E-cadherin level and downregulated N-cadherin and α-SMA) in ovalbumin-challenged asthmatic mice. For in vitro analysis, scutellarin prevented the TGF-β1-induced migration and EMT in 16HBE cells. Mechanistically, scutellarin inhibits the phosphorylation of Smad2, Smad3, ERK, JNK, and p38 in vitro and in vivo. In conclusion, scutellarin can inactivate the Smad/MAPK pathways to suppress the TGF-β1-stimulated epithelial fibrosis and EMT and relieve airway inflammation and remodeling in asthma. This study provides a potential therapeutic strategy for asthma.

Natural products and derivatives in renal, urothelial and testicular cancers: Targeting signaling pathways and therapeutic potential

BACKGROUND

Natural products have demonstrated significant potential in cancer drug discovery, particularly in renal cancer (RCa), urothelial carcinoma (UC), and testicular cancer (TC).

PURPOSE

This review aims to examine the effects of natural products on RCa, UC and TC.

STUDY DESIGN

systematic review METHODS: PubMed and Web of Science databases were retrieved to search studies about the effects of natural products and derivatives on these cancers. Relevant publications in the reference list of enrolled studies were also checked.

RESULTS

This review highlighted their diverse impacts on key aspects such as cell growth, apoptosis, metastasis, therapy response, and the immune microenvironment. Natural products not only hold promise for novel drug development but also enhance the efficacy of existing chemotherapy and immunotherapy. Importantly, we exert their effects through modulation of critical pathways and target genes, including the PI3K/AKT pathway, NF-κB pathway, STAT pathway and MAPK pathway, among others in RCa, UC, and TC.

CONCLUSION

These mechanistic insights provide valuable guidance for researchers, facilitating the selection of promising natural products for cancer management and offering potential avenues for further gene regulation studies in the context of cancer treatment.

Modulation of hypoxia-inducible factor-1 signaling pathways in cancer angiogenesis, invasion, and metastasis by natural compounds: a comprehensive and critical review

Tumor cells employ multiple signaling mediators to escape the hypoxic condition and trigger angiogenesis and metastasis. As a critical orchestrate of tumorigenic conditions, hypoxia-inducible factor-1 (HIF-1) is responsible for stimulating several target genes and dysregulated pathways in tumor invasion and migration. Therefore, targeting HIF-1 pathway and cross-talked mediators seems to be a novel strategy in cancer prevention and treatment. In recent decades, tremendous efforts have been made to develop multi-targeted therapies to modulate several dysregulated pathways in cancer angiogenesis, invasion, and metastasis. In this line, natural compounds have shown a bright future in combating angiogenic and metastatic conditions. Among the natural secondary metabolites, we have evaluated the critical potential of phenolic compounds, terpenes/terpenoids, alkaloids, sulfur compounds, marine- and microbe-derived agents in the attenuation of HIF-1, and interconnected pathways in fighting tumor-associated angiogenesis and invasion. This is the first comprehensive review on natural constituents as potential regulators of HIF-1 and interconnected pathways against cancer angiogenesis and metastasis. This review aims to reshape the previous strategies in cancer prevention and treatment.

Scutellarin suppresses the metastasis of triple-negative breast cancer via targeting TNFα/TNFR2-RUNX1-triggered G-CSF expression in endothelial cells

Triple-negative breast cancer (TNBC) is heterogeneous and aggressive, with high vascularity and frequent metastasis. We have already found natural flavonoid scutellarin (SC) suppressed spontaneous TNBC metastasis via normalizing tumor vasculature in vivo. In this study, supernatant from tumor necrosis factorα (TNFα)-treated human mammary microvascular endothelial cell (HMMEC) promoted cell migration and pseudopod formation in TNBC cells, but these phenomena were disappeared in SC-co-treated HMMEC. TNFα enhanced the expression of granulocyte colony-stimulating factor (G-CSF) and granulocyte-macrophage colony-stimulating factor (GM-CSF) in both HMMEC and human umbilical vein endothelial cell (HUVEC). G-CSF promoted TNBC migration and invasion in vitro, while G-CSF neutralization antibody and SC both inhibited TNBC metastasis in Balb/c mice. SC had no inhibition on the G-CSF-induced TNBC cell migration, but reduced G-CSF content in TNBC tumor tissues and TNFα-stimulated endothelial cells (ECs). SC restricted the nuclear translocation of runt-related transcription factor 1 (RUNX1) in TNBC tumor vessels and TNFα-treated ECs. RUNX1 was found to directly bind to the promoter of G-CSF in TNBC tumor vessels and regulated G-CSF expression. TNF receptor 2 (TNFR2) was crucial for regulating the TNFα-induced RUNX1 activation and G-CSF expression. Notably, SC hindered the interaction between TNFα and TNFR2 via binding to TNFR2. This work demonstrated that SC reduced TNBC metastasis by targeting TNFα/TNFR2-initiated RUNX1 activation and subsequent G-CSF production in TNBC-associated ECs.

Induction of RIPK3/MLKL-mediated necroptosis by Erigeron breviscapus injection exhibits potent antitumor effect

Colorectal cancer (CRC) is the second leading cause of tumor-related deaths worldwide. Resistance of tumor cells to drug-induced apoptosis highlights the need for safe and effective antitumor alternatives. Erigeron breviscapus (Dengzhanxixin in China) injection (EBI), extracted from the natural herb Erigeron breviscapus (Vant.) Hand.-Mazz (EHM), has been widely used in clinical practice for cardiovascular diseases. Recent studies have suggested that EBI's main active ingredients exhibit potential antitumor effects. This study aims to explore the anti-CRC effect of EBI and elucidate the underlying mechanism. The anti-CRC effect of EBI was evaluated in vitro using CCK-8, flow cytometry, and transwell analysis, and in vivo through a xenograft mice model. RNA sequencing was utilized to compare the differentially expressed genes, and the proposed mechanism was verified through in vitro and in vivo experiments. Our study demonstrates that EBI significantly inhibits the proliferation of three human CRC cell lines and effectively suppresses the migration and invasion of SW620 cells. Moreover, in the SW620 xenograft mice model, EBI markedly retards tumor growth and lung metastasis. RNA-seq analysis revealed that EBI might exert antitumor effects by inducing necroptosis of tumor cells. Additionally, EBI activates the RIPK3/MLKL signaling pathway, a classical pathway of necroptosis and greatly promotes the generation of intracellular ROS. Furthermore, the antitumor effect of EBI on SW620 is significantly alleviated after the pretreatment of GW806742X, the MLKL inhibitor. Our findings suggest that EBI is a safe and effective inducer of necroptosis for CRC treatment. Notably, necroptosis is a non-apoptotic programmed cell death pathway that can effectively circumvent resistance to apoptosis, which provides a novel approach for overcoming tumor drug resistance.

Scutellarin, a promising flavonoid in cancer treatment

Natural substances are increasingly being used as cancer treatments. Scutellarin, as a flavonoid, recently has been identified in a Chinese herbal extract called Erigeron breviscapus (Vant.). Scutellarin is being researched for its potential benefits due to the discovery that it possesses a variety of biological effects, such as neuroprotective, anti-coagulant, and anti-viral. In addition to these biological functions, scutellarin has also been found to have anti-tumor properties. Scutellarin first inhibits the activity of tumor cells by altering cancer cell signaling pathways such as Jak/STAT, ERK/AMPK, and Wnt/β-catenin. Additionally, scutellarin activates intrinsic and extrinsic apoptotic pathways, which causes the death of tumor cells, interrupts the cell cycle, and promotes its arrest. By limiting metastasis, angiogenesis, drug resistance, and other tumorigenic processes, scutellarin also reduces the aggressiveness of tumors. Utilizing scutellarin in combination with other anti-tumor therapies like 5-fluorouracil is another method to overcome tumor cell resistance. Moreover, it has been suggested that certain modifications, such as conjugation with cyclodextrin, aliphatic chains, and hybridization with nitric oxide, can enhance the pharmacogenetic capabilities of scutellarin to decrease its limited water solubility. It is believed that scutellarin may provide innovative chemotherapeutic treatments for cancer in the future.

Scutellarin suppresses triple-negative breast cancer metastasis by inhibiting TNFα-induced vascular endothelial barrier breakdown

Triple-negative breast cancer (TNBC) is an aggressive subtype of breast cancer with high vascularity and frequent metastasis. Tumor-associated abnormal vasculature was reported to accelerate TNBC metastasis. Scutellarin (SC) is a natural flavonoid with a cardiovascular protective function. In this study, SC reduced TNBC metastasis and alleviated tumor-associated vascular endothelial barrier injury in vivo. SC rescued the tumor necrosis factor-α (TNFα)-induced diminishment of endothelial junctional proteins and dysfunction of the endothelial barrier in vitro. SC reduced the increased transendothelial migration of TNBC cells through a monolayer composed of TNFα-stimulated human mammary microvascular endothelial cells (HMMECs) or human umbilical vein endothelial cells (HUVECs). TNFα induced the nuclear translocation of enhancer of zeste homolog-2 (EZH2), and its chemical inhibitor GSK126 blocked TNFα-induced endothelial barrier disruption and subsequent TNBC transendothelial migration. TNF receptor 2 (TNFR2) is the main receptor by which TNFα regulates endothelial barrier breakdown. Extracellular signal-regulated protein kinase (ERK)1/2 was found to be downstream of TNFα/TNFR2 and upstream of EZH2. Additionally, SC abrogated the TNFR2-ERK1/2-EZH2 signaling axis both in vivo and in vitro. Our results suggest that SC reduced TNBC metastasis by suppressing TNFα-initiated vascular endothelial barrier breakdown through rescuing the reduced expression of junctional proteins by regulating the TNFR2-ERK1/2-EZH2 signaling pathway.

Bladder cancer cell lines adapt their aggressiveness profile to oxygen tension

During the process of tumor growth, cancer cells will be subjected to intermittent hypoxia. This results from the delay in the development of the vascular network in relation to the proliferation of cancer cells. The hypoxic nature of a tumor has been demonstrated as a negative factor for patient survival. To evaluate the impact of hypoxia on the survival and migration properties of low and high-grade bladder cancer cell lines, two low-grade (MGHU-3 and SW-780) and two high-grade (SW-1710 and T24) bladder cancer cell lines were cultured in normoxic (20% O₂) or hypoxic atmospheric conditions (2% O₂). The response of bladder cancer cell lines to hypoxic atmospheric cell culture conditions was examined under several parameters, including epithelial-mesenchymal transition, doubling time and metabolic activities, thrombospondin-1 expression, whole Matrix Metallo-Proteinase activity, migration and resistance to oxidative stress. The low-grade cell line response to hypoxia was heterogeneous even if it tended to adopt a more aggressive profile. Hypoxia enhanced migration and pro-survival properties of MGHU-3 cells, whereas these features were reduced for the SW-780 cell line cultured under low oxygen tension. The responses of tested high-grade cell lines were more homogeneous and tended to adopt a less aggressive profile. Hypoxia drastically changed some of the bladder cancer cell line properties, for example matrix metalloproteinases expression for all cancer cells but also switch in glycolytic metabolism of low grade cancer cells. Overall, studying bladder cancer cells in hypoxic environments are relevant for the translation from in vitro findings to in vivo context.

Novel Insights of Herbal Remedy into NSCLC Suppression through Inducing Diverse Cell Death Pathways via Affecting Multiple Mediators

Artemisia species previously have been reported to have antimicrobial, antioxidant, antiulcer, and anticancer properties. In this study, we investigated the prospective antitumor effects of Artemisia santolinifolia ethanol extract (ASE) against two non-small cell lung cancer (NSCLC) cell lines and their molecular mechanisms of action. Morphological observations and flow cytometric analyses showed that ASE induced cell death in A549 and H23 cells but with different action features. Further studies by Western blotting showed that ASE induced caspase-3 cleavage in H23 cells, suggesting caspase-dependent apoptosis was predominantly involved in H23 cell death. Contrarily, ASE treatment selectively altered the glutathione peroxidase (GPX4) protein expression, reactive oxygen species (ROS) generation, and lipid peroxidation in A549 cells, all of which are linked to ferroptosis. Using a ferroptosis inhibitor (desferrioxamine (DFO)), further study showed that DFO could significantly rescue ASE-induced cell death. All these results implied that ASE induced ferroptosis predominately in A549 cells. Several studies have demonstrated that the nuclear factor erythroid 2–related factor 2 (NRF2) can be dual-selectively targeted depending on the cell line. Subsequently, it can exert opposing effects until either being activated or suppressed. This was consistent with our data, which might explain inconsistent observations of the cell death type in this study. In addition, after ASE treatment, signal transduction and activator of transcription 3 (STAT3) were inhibited in both cell lines. Consequently, downstream prosurvival proteins, including heat shock protein 70 (HSP70) and survivin, which play pivotal roles in the STAT3 pathway, decreased after ASE administration. Our findings revealed that ASE inhibited NSCLC cell proliferation by simultaneously downregulating prosurvival protein expressions and activating multiple cell death pathways.

Inhibitors and Activators of the p38 Mitogen- Activated MAP Kinase (MAPK) Family as Drugs to Treat Cancer and Inflammation

The p38 MAP kinases are a sub-family of the broad group of mitogen-activated serine-threonine protein kinases. The best-characterised, most widely expressed, and most targeted by drugs is p38α MAP kinase. This review briefly summarises the place of p38α MAP kinase in cellular signalling and discusses the structures and activity profiles of representative examples of the major classes of inhibitors and activators (both synthetic compounds and natural products) of this enzyme. Primary screening was primarily direct in vitro inhibition of isolated p38α enzyme.

EGR1 promoted anticancer effects of Scutellarin via regulating LINC00857/miR-150-5p/c-Myc in osteosarcoma

Scutellarin, an active flavone extracted from Erigeron breviscapus, is known to exhibit antitumour activity in many cancers. However, the effects of Scutellarin on osteosarcoma remain unclear. In this study, we found that Scutellarin suppressed osteosarcoma cell growth, induced cell apoptosis and inhibited tumorigenesis. Mechanistically, our data revealed that EGR1 was significantly increased under Scutellarin treatment. Increased EGR1 enhanced tumour‐suppressive effects of Scutellarin on osteosarcoma cells via transcriptionally downregulating LINC00857 expression. Additionally, we found that LINC00857 acted as a competitive endogenous RNA of miR‐150‐5p and inhibited the activity of miR‐150‐5p, which resulted in c‐Myc increase. Scutellarin could suppress c‐Myc protein levels through decreasing LINC00857 expression in osteosarcoma. Thus, these findings demonstrate that EGR1/ LINC00857/miR‐150‐5p/c‐Myc axis plays a key role in promoting anticancer effects of Scutellarin and Scutellarin might have potential clinical implication in osteosarcoma clinical treatment.

Scutellarin improves the radiosensitivity of non-small cell lung cancer cells to iodine-125 seeds via downregulating the AKT/mTOR pathway

Background

In our previous study, we indicated that scutellarin (SCU) induced an anticancer effect in A549 cells. However, whether SCU regulates the radiosensitivity of non‐small cell lung cancer (NSCLC) and its related mechanism is still unclear.

Methods

In this study, we explored the anticancer effect induced by iodine‐125 (¹²⁵I) and SCU at a sensitizing concentration in A549 and H1975 cells. Cellular apoptosis and proliferation were detected by flow cytometry, Bcl‐2/Bax expression level, cell cycle, CCK‐8, and EdU staining. A tumor model using nude mice was also carried out to investigate the combined effect of ¹²⁵I and SCU in vivo. In addition, the expression level of AKT/mTOR pathway was detected to investigate whether it is linked to the anticancer effect of ¹²⁵I and SCU.

Results

SCU at a sensitizing concentration promoted the ¹²⁵I‐induced apoptosis and antiproliferative effect in A549 and H1975 cells. Moreover, the same results were obtained in vivo. Based on our findings, the AKT/mTOR pathway was significantly downregulated after combined treatment with ¹²⁵I and SCU.

Conclusions

The results of our study suggested that SCU promotes the anticancer effects induced by ¹²⁵I in NSCLC cells by downregulating the AKT/mTOR pathway and lays a foundation for future application of this combined treatment.

Flavonoids as an effective sensitizer for anti-cancer therapy: insights into multi-faceted mechanisms and applicability towards individualized patient profiles

Cost-efficacy of currently applied treatments is an issue in overall cancer management challenging healthcare and causing tremendous economic burden to societies around the world. Consequently, complex treatment models presenting concepts of predictive diagnostics followed by targeted prevention and treatments tailored to the personal patient profiles earn global appreciation as benefiting the patient, healthcare economy, and the society at large. In this context, application of flavonoids as a spectrum of compounds and their nano-technologically created derivatives is extensively under consideration, due to their multi-faceted anti-cancer effects applicable to the overall cost-effective cancer management, primary, secondary, and even tertiary prevention. This article analyzes most recently updated data focused on the potent capacity of flavonoids to promote anti-cancer therapeutic effects and interprets all the collected research achievements in the frame-work of predictive, preventive, and personalized (3P) medicine. Main pillars considered are: - Predictable anti-neoplastic, immune-modulating, drug-sensitizing effects; - Targeted molecular pathways to improve therapeutic outcomes by increasing sensitivity of cancer cells and reversing their resistance towards currently applied therapeutic modalities.

Endoplasmic Reticulum Stress and Tumor Microenvironment in Bladder Cancer: The Missing Link

Bladder cancer is a common malignant tumor of the urinary system. Despite recent advances in treatments such as local or systemic immunotherapy, chemotherapy, and radiotherapy, the high metastasis and recurrence rates, especially in muscle-invasive bladder cancer (MIBC), have led to the evaluation of more targeted and personalized approaches. A fundamental understanding of the tumorigenesis of bladder cancer along with the development of therapeutics to target processes and pathways implicated in bladder cancer has provided new avenues for the management of this disease. Accumulating evidence supports that the tumor microenvironment (TME) can be shaped by and reciprocally act on tumor cells, which reprograms and regulates tumor development, metastasis, and therapeutic responses. A hostile TME, caused by intrinsic tumor attributes (e.g., hypoxia, oxidative stress, and nutrient deprivation) or external stressors (e.g., chemotherapy and radiation), disrupts the normal synthesis and folding process of proteins in the endoplasmic reticulum (ER), culminating in a harmful situation called ER stress (ERS). ERS is a series of adaptive changes mediated by unfolded protein response (UPR), which is interwoven into a network that can ultimately mediate cell proliferation, apoptosis, and autophagy, thereby endowing tumor cells with more aggressive behaviors. Moreover, recent studies revealed that ERS could also impede the efficacy of anti-cancer treatment including immunotherapy by manipulating the TME. In this review, we discuss the relationship among bladder cancer, ERS, and TME; summarize the current research progress and challenges in overcoming therapeutic resistance; and explore the concept of targeting ERS to improve bladder cancer treatment outcomes.

Scutellarin Inhibits the Growth and EMT of Gastric Cancer Cells through Regulating PTEN/PI3K Pathway

Gastric cancer is one of the most common malignancies with a high mortality rate world. This study intends to make clear the role and mechanism of the Scutellarin (Scu), a flavonoid isolated from Erigeron breviscapus (Vant.) Hand.-Mazz, in regulating the evolvement of gastric cancer. We selected different doses of Scu to treat gastric cancer cells (MGC-803 and AGS). Then, cell counting kit-8 (CCK8) assay was conducted to verify the proliferation of tumor cells, while flow cytometry was adopted to test the apoptosis rate. Meanwhile, Western blot was conducted to examine epithelial-mesenchymal transition (EMT) markers and the expression of phosphatase and tensin homolog (PTEN)/phosphatidylinositol 3-kinase (PI3K) and apoptosis-related proteins (Bax, Bcl2 and Caspase3). Moreover, xenograft tumor experiment in nude mice was established to verify the effect of Scu on tumor growth. Furthermore, the knockdown model of PTEN was constructed, and the influence of PTEN on the anti-tumor effect of Scu was investigated. As a result, Scu inhibited cell proliferation, EMT and promoted the apoptosis in gastric cancer dose-dependently. Additionally, Scu attenuated tumor cell growth in vivo. Besides, Scu enhanced the expression of PTEN while reduced the phosphorylated level of PI3K. Moreover, the mechanistic study proved that Scu inactivated PI3K by up-regulating PTEN, thus dampening tumor progression. In conclusion, Scu dampened the growth and EMT of gastric cancer by regulating the PTEN/PI3K pathway.

Flavonoids in Cancer Metastasis

Metastasis represents a serious complication in the treatment of cancer. Flavonoids are plant secondary metabolites exerting various health beneficiary effects. The effects of flavonoids against cancer are associated not only with early stages of the cancer process, but also with cancer progression and spread into distant sites. Flavonoids showed potent anti-cancer effects against various cancer models in vitro and in vivo, mediated via regulation of key signaling pathways involved in the migration and invasion of cancer cells and metastatic progression, including key regulators of epithelial-mesenchymal transition or regulatory molecules such as MMPs, uPA/uPAR, TGF-β and other contributors of the complex process of metastatic spread. Moreover, flavonoids modulated also the expression of genes associated with the progression of cancer and improved inflammatory status, a part of the complex process involved in the development of metastasis. Flavonoids also documented clear potential to improve the anti-cancer effectiveness of conventional chemotherapeutic agents. Most importantly, flavonoids represent environmentally-friendly and cost-effective substances; moreover, a wide spectrum of different flavonoids demonstrated safety and minimal side effects during long-termed administration. In addition, the bioavailability of flavonoids can be improved by their conjugation with metal ions or structural modifications by radiation. In conclusion, anti-cancer effects of flavonoids, targeting all phases of carcinogenesis including metastatic progression, should be implemented into clinical cancer research in order to strengthen their potential use in the future targeted prevention and therapy of cancer in high-risk individuals or patients with aggressive cancer disease with metastatic potential.

RAC1 Involves in the Radioresistance by Mediating Epithelial-Mesenchymal Transition in Lung Cancer

Radiation therapy is a common and acceptable approach for lung cancer. Although the benefit of ionizing radiation (IR) is well-established, cancer cells can still survive via pro-survival and metastasis signaling pathways. Ras related C3 botulinum toxin substrate1 (RAC1), a member of Rho family GTPases, plays important roles in cell migration and survival. In the present study, we investigated the effects of RAC1 on the survival of lung cancer cells treated with irradiation. The results showed RAC1 is overexpressed in lung cancer cells and promoted cell proliferation and survival. Furthermore, IR induced RAC1 expression and activity via the activation of PI3K/AKT signaling pathway, and then enhancing cell proliferation, survival, migration and metastasis and increasing levels of epithelial-to-mesenchymal transition (EMT) markers, which facilitated the cell survival and invasive phenotypes. In addition, overexpression of RAC1 attenuated the efficacy of irradiation, while inhibition of RAC1 enhanced sensitivity of irradiation in xenograft tumors in vivo. Collectively, we further found that RAC1 enhanced radioresistance by promoting EMT via targeting the PAK1-LIMK1-Cofilins signaling in lung cancer. Our finding provides the evidences to explore RAC1 as a therapeutic target for radioresistant lung cancer cells.

Bioinformatics Analysis of the Expression of Key Long Intergenic Non-Protein Coding RNA Genes in Bladder Cancer

Background

Evidence indicates that there is an important role for long non-coding RNAs (lncRNA) in numerous cellular processes and that lncRNAs dysregulation contributes to tumor progression. Improved insight into the molecular characteristics of bladder cancer is required to predict outcomes and to develop a new rationale for targeted therapeutic strategies. Bioinformatics methods, including functional enrichment and network analysis combined with survival analysis, are required to process a large volume of data to obtain further information about differentially expressed genes (DEGs) in bladder cancer. This study aimed to explore the role of lncRNAs and their regulation network in bladder cancer.

Material/Methods

We analyzed bladder cancer data by The Cancer Genome Atlas profiling to identify differentially expressed lncRNAs in bladder cancer. The genes involved in the circlncRNAnet database were evaluated using Kyoto Encyclopedia of Genes and Genomes (KEGG), Gene Ontology (GO), evolutionary relationship analysis, and protein-protein interaction (PPI) networks.

Results

Two new lncRNAs, ADAMTS9-AS1 and LINC00460, were shown to be differentially expressed in bladder cancer. Patients were divided into 2 groups (high expression and low expression) according to their median expression values. The overall survival and disease-free survival of patients with high ADAMTS9-AS1 bladder cancer were significantly shorter; the expression of LINC00460 had no significant correlation with survival. GO and KEGG analysis of the 2 lncRNA-related genes revealed that these lncRNAs played a vital role in tumorigenesis. Bioinformatics analysis showed that key genes related to LINC00460, including CXCL, CCL, and CSF2, may be related to the development of bladder cancer. The low expression of ADAMTS9-AS1 may influence the survival rate of bladder cancer with the hub gene as a target.

Conclusions

LncRNA, including LINC00460 and ADAMTS9-AS1, might play a crucial role in the biosynthesis network of bladder cancer. Differential expression results of ADAMTS9-AS1 suggests it may be correlated with a worse prognosis and a shorter survival time. We outlined the biosynthesis network that regulates lncRNAs in bladder cancer. Further experimental data is needed to validate our results.

MicroRNA-519 inhibits hypoxia-induced tumorigenesis of pancreatic cancer by regulating immune checkpoint PD-L1

Pancreatic cancer is highly prevalent and exhibits a high incidence and mortality rate. Hypoxia contributes to tumorigenesis and the progression of pancreatic cancer. To the best of our knowledge, the role of microRNA (miR)-519 has not been investigated in hypoxia-induced pancreatic cancer progression. The purpose of the present study was to elucidate the mechanism underlying miR-519-mediated regulation of pancreatic cancer progression. Reverse transcription-quantitative PCR and western blotting were performed to investigate miR-519 and programmed death ligand 1 (PD-L1) mRNA and protein levels, respectively. Additionally, a Transwell assay was performed to examine the invasiveness of PANC-1 and SW1990 cells. Cells were subsequently stained with Annexin V to determine the apoptotic rate of cells. Furthermore, bioinformatics analysis and a dual-luciferase reporter assay were performed to confirm the direct association between miR-519 and PD-L1, and a xenograft experiment was conducted to test the role of miR-519 in vivo. The results revealed that the expression levels of miR-519 in pancreatic cancer cells were reduced following hypoxia treatment. Furthermore, transfection with miR-519 mimics inhibited PANC-1 and SW1990 cell invasiveness, and induced apoptosis under hypoxic conditions. PD-L1 was also identified as a downstream target of miR-519, and rescued the miR-519 mimic-attenuated tumorigenesis of pancreatic cancer cells under hypoxic conditions. Additionally, treatment with miR-519 mimics significantly suppressed the tumor growth of PANC-1 cells. The results of the present study indicated a novel mechanism of miR-519-mediated tumorigenesis in pancreatic cancer cells under hypoxic conditions. The conclusions may be crucial for the improvement of future pancreatic cancer treatment.