Dauricine inhibits insulin-like growth factor-I-induced hypoxia inducible factor 1alpha protein accumulation and vascular endothelial growth factor expression in human breast cancer cells

Dauricine: Review of Pharmacological Activity

Background

Dauricine is an important natural organic compound in Menispermum dauricum, which often has significant biological activity.

Purpose

The purpose of this review is to systemically summarize and discuss the pharmacological activity and underlying mechanisms of dauricine in recent years.

Methods

Web of Science (121 articles) and PubMed databases (97 articles) were used to search for articles related to "dauricine" published from 2000 to 2024. Meanwhile, we classified the pharmacological activity of dauricine by screening these articles.

Results

Emerging evidence suggests that dauricine possesses numerous pharmacological activities, including neuroprotection, anti-cancer, anti-arrhythmia, anti-inflammatory and anti-diabetes.

Conclusion

Dauricine has a potential value in the treatment of many diseases. We hope that this review will contribute to therapeutic development and future studies of dauricine.

N-desmethyldauricine from Menispermum dauricum DC suppresses triple-negative breast cancer growth in 2D and 3D models by downregulating the NF-κB signaling pathway

Triple negative breast cancer (TNBC) is the most aggressive subtype of breast cancer, for which targeted therapy regimens are lacking. The traditional Chinese medicine Menispermum dauricum DC (M. dauricum) and its compounds have been reported to have antitumor activity against various cancers; however, their anti-TNBC activity is unknown. In this work, dauricine and N-desmethyldauricine from M. dauricum were separated and identified to have anti-TNBC via a multi-component bioactivity and structure-guided method. The cell counting kit 8 assay showed that dauricine and N-desmethyldauricine inhibited the proliferation of four tested TNBC cell lines, with half maximal inhibitory concentration values ranging from 5.01 μM to 13.16 μM. Further research suggested that N-desmethyldauricine induced cell apoptosis, arrested cell cycle progression in the G0/G1 phase, and inhibited cell migration. Western blot analysis revealed that the proapoptotic protein cleaved-poly-ADP-ribose polymerase 1 was upregulated, and the G0/G1 phase-related proteins cyclin-dependent kinase 2 and cyclin D1 and the migration-related protein matrix metallopeptidase 9 were downregulated. Furthermore, N-desmethyldauricine decreased the protein expression of p65, an important subunit of nuclear factor kappa-beta (NF-κB). Moreover, an antiproliferation assay of three-dimensional (3D) tumor spheroids showed that N-desmethyldauricine diminished cell‒cell adhesion and suppressed the growth of TNBC 3D spheroids. Taken together, these findings indicate that N-desmethyldauricine inhibited the proliferation of TNBC cells and decreased the expression of p65 in the NF-κB pathway.

Dauricine interferes with SARS-CoV-2 variants infection by blocking the interface between RBD and ACE2

The continued viral evolution results in the emergence of various SARS-CoV-2 variants, such as delta or omicron, that are partially resistant to current vaccines and antiviral medicines, posing an increased risk to global public health and raising the importance of continuous development of antiviral medicines. Inhibitor screening targeting the interactions between the viral spike proteins and their human receptor ACE2 represents a promising approach for drug discovery. Here, we demonstrate that the evolutionary trend of the SARS-CoV-2 variants is associated with increased electrostatic interactions between S proteins and ACE2. Virtual screening based on the ACE2-RBD binding interface identified nine monomers of Traditional Chinese medicine (TCM). Furthermore, live-virus neutralization assays revealed that Dauricine, one of the identified monomers, exhibited an antiviral activity with an IC50 range of 18.2 to 33.3 μM for original strain, Delta, and Omicron strains, respectively. The computational study showed that the polycyclic and methoxy groups of Dauricine adhere to the RBD surface through π-π and electrostatic interactions. The discovery of Dauricine is a successful attempt to target viral entry, which will not only help society to respond quickly to viral variants, but also accelerate variant drug development thereby reducing the pressure on health authorities to respond to outbreaks.

Isoquinolines alkaloids and cancer metabolism: Pathways and targets to novel chemotherapy

Cancer is one of the main causes of death in the world. This is a complex disease where the development of resistance to chemotherapy is frequent driving the search for new anticancer compounds. In this sense, isoquinolines have gained attention in the past few years. This review aims to highlight the new advances related to the use of isoquinolines compounds against cancer cells, and we point out targets for their anti-tumor action. Isoquinolines are compounds found in plants that are important for their protection. In cancer, many representatives of this class of compounds have demonstrated their efficacy against cancer by acting on cancer metabolism, such as triggering cell death, reducing pro-survival protein expression, inducing ROS production, inhibiting pro-survival cell signaling pathways, among other effects. The mechanisms triggered by isoquinolines in cancer cells represent robust anticancer strategies, which support that this class of compounds are strong candidates for cancer treatment.

Multifaceted Interplay between Hormones, Growth Factors and Hypoxia in the Tumor Microenvironment

Hormones and growth factors (GFs) are signaling molecules implicated in the regulation of a variety of cellular processes. They play important roles in both healthy and tumor cells, where they function by binding to specific receptors on target cells and activating downstream signaling cascades. The stages of tumor progression are influenced by hormones and GF signaling. Hypoxia, a hallmark of cancer progression, contributes to tumor plasticity and heterogeneity. Most solid tumors contain a hypoxic core due to rapid cellular proliferation that outgrows the blood supply. In these circumstances, hypoxia-inducible factors (HIFs) play a central role in the adaptation of tumor cells to their new environment, dramatically reshaping their transcriptional profile. HIF signaling is modulated by a variety of factors including hormones and GFs, which activate signaling pathways that enhance tumor growth and metastatic potential and impair responses to therapy. In this review, we summarize the role of hormones and GFs during cancer onset and progression with a particular focus on hypoxia and the interplay with HIF proteins. We also discuss how hypoxia influences the efficacy of cancer immunotherapy, considering that a hypoxic environment may act as a determinant of the immune-excluded phenotype and a major hindrance to the success of adoptive cell therapies.

Dauricine inhibits human pancreatic carcinoma cell proliferation through regulating miRNAs

Pancreatic cancer is one of the most malignant digestive tract tumors with the worst prognosis. Dauricine (Dau) can inhibit the proliferation of the pancreatic cancer cell line, and has the potential to be used as an adjuvant drug against pancreatic cancer; however, the working mechanism of Dau has not been elucidated. To unravel the effects and mechanisms of Dau on proteins and metabolic pathways, we evaluated the mRNA and microRNA expression in BxPC3 cells treated with Dau. The differences in the gene expression were compared using principal component analysis using mRNA and miRNA data to detect and analyze the sample discrimination. 187 miRNA and 907 mRNA that were significantly differentially expressed were identified using Python programming. On comparing genes and miRNAs in the DISEASES database, 79 known miRNA and 47 mRNA were found to be affected by Dau. The up-regulated and down-regulated genes were annotated with GO biological processes to determine the functional effect. Interactions between mRNA and mRNA were analyzed using the STRING database and the miRBase database was queried to obtain experimentally verified interactions between miRNA and mRNA as edges of miRNA and mRNA in the network. Finally, 413 sites and 2125 sides of the network were obtained, including 1 up-regulated and 18 down-regulated miRNAs. The expression of 19 miRNAs was identified by qPCR. The analysis of the protein-protein interaction network, using the Molecular Complex Detection (MCODE) plug-in of cytoscape, helped in identifying 12 important sub-networks. Most subnets are indirectly or directly related to specific miRNAs. This study provides evidence for the anticancer effect of Dau as a potential anticancer compound.

Dauricine inhibits proliferation and promotes death of melanoma cells via inhibition of Src/STAT3 signaling

Melanoma is the most common type of skin cancer. Signal transducer and activator of transcription 3 (STAT3) signaling has been demonstrated to be a therapeutic target for melanoma. Dauricine (Dau), an alkaloid compound isolated from the root of Menispermum dauricum DC., has shown tumor-suppressing effects in multiple human cancers, but its potential in melanoma remains unexplored. In this study, we demonstrated that Dau significantly inhibited the viability and proliferation of A375 and A2058 melanoma cells. Death of melanoma cells was also markedly promoted by Dau. Moreover, Dau inhibited phosphorylation-mediated activation of STAT3 and Src in a dose-dependent manner. Notably, constitutive activation of Src partially abolished the antiproliferative and cytotoxic activities of Dau on melanoma cells. Molecular docking showed that Dau could dock on the kinase domain of Src with a binding energy of -10.42 kcal/mol. Molecular dynamics simulations showed that Src-Dau binding was stable. Surface plasmon resonance imaging analysis also showed that Dau has a strong binding affinity to Src. In addition, Dau suppressed the growth of melanoma cells and downregulated the activation of Src/STAT3 in a xenograft model in vivo. These data demonstrated that Dau inhibits proliferation and promotes cell death in melanoma cells by inhibiting the Src/STAT3 pathways.

Dauricine Attenuates Spatial Memory Impairment and Alzheimer-Like Pathologies by Enhancing Mitochondrial Function in a Mouse Model of Alzheimer's Disease

Alzheimer's disease (AD) is characterized by extracellular amyloid plaques composed of β-amyloid (Aβ) and intracellular neurofibrillary tangles containing hyperphosphorylated tau protein. No effective therapy is available for this disease. In this study, we investigated the potential therapeutic effects of dauricine (DAU), a benzyl tetrahydroisoquinoline alkaloid, on AD, and found that DAU administration significantly improved cognitive impairments in 3xTg-AD mice by decreasing Aβ plaques and hyperphosphorylated tau and increasing the hippocampal ATP level. Proteomic and western blot analyses revealed that DAU treatment mainly modified the expression of proteins involved in mitochondrial energy metabolism, such as Aco2, Ndufs1, Cox5a, and SDHB, and that of synapse-related proteins such as Syn1 and Syn2. Pathway analysis revealed that DAU modulated the tricarboxylic acid cycle, synaptic vesicle cycle, glycolysis, and gluconeogenesis in 3xTg-AD mice. Our study suggests that DAU may be a potential drug for the treatment of AD.

Modulation of Multiple Signaling Pathways of the Plant-Derived Natural Products in Cancer

Natural compounds are highly effective anticancer chemotherapeutic agents, and the targets of plant-derived anticancer agents have been widely reported. In this review, we focus on the main signaling pathways of apoptosis, proliferation, invasion, and metastasis that are regulated by polyphenols, alkaloids, saponins, and polysaccharides. Alkaloids primarily affect apoptosis-related pathways, while polysaccharides primarily target pathways related to proliferation, invasion, and metastasis. Other compounds, such as flavonoids and saponins, affect all of these aspects. The association between compound structures and signaling pathways may play a critical role in drug discovery.

Dauricine suppresses the growth of pancreatic cancer in vivo by modulating the Hedgehog signaling pathway

Pancreatic cancer is a highly malignant cancer associated with high expression levels of sonic hedgehog signaling molecule (Shh), patched 1 (Ptch1), smoothened frizzled class receptor (Smo) and glioma-associated oncogene family zinc finger 1 (Gli1) in the hedgehog (Hh) signaling pathway. Inhibition of the Hh signaling pathway is a potential therapeutic target for pancreatic cancer. The aim of the present study was to investigate the effects of dauricine in a pancreatic cancer BxPC-3 ×enograft animal model and examine the underlying molecular mechanisms through Hh signaling pathway. High-and low-dose dauricine treatment significantly suppressed tumor growth with no concomitant effect on the spleen index. In addition, dauricine induced apoptosis and cell cycle arrest in pancreatic cancer BxPC-3 cells. The inhibitory effects of dauricine on pancreatic cancer may be mediated by the suppression of the Hh signaling pathway, as indicated by the decreases in the gene and protein expression levels of Shh, Ptch1, Smo and Gli1. The effects of dauricine were similar to those of 5-fluorouracil. Dauricine, a naturally occurring alkaloid, may be a potential anticancer agent for the treatment of pancreatic cancer.

Vanillic Acid Suppresses HIF-1α Expression via Inhibition of mTOR/p70S6K/4E-BP1 and Raf/MEK/ERK Pathways in Human Colon Cancer HCT116 Cells

Hypoxia-inducible factor 1 (HIF-1) plays a pivotal role in tumor adaptation to microenvironmental hypoxia, and it also exerts important roles in angiogenesis and tumor development. Vanillic acid is a dietary phenolic compound reported to exhibit anticancer properties. However, the mechanisms by which vanillic acid inhibits tumor growth are not fully understood. Here, we investigated the effect of vanillic acid on HIF-1α activation. Vanillic acid significantly inhibits HIF-1α expression induced by hypoxia in various human cancer cell lines. Further analysis revealed that vanillic acid inhibited HIF-1α protein synthesis. Neither the HIF-1α protein degradation rate nor the steady-state HIF-1α mRNA levels were affected by vanillic acid. Moreover, vanillic acid inhibited HIF-1α expression by suppressing mammalian target of rapamycin/p70 ribosomal protein S6 kinase/eukaryotic initiation factor 4E-binding protein-1 and Raf/extracellular signal-regulated kinase (ERK) kinase (MEK)/ERK pathways. We found that vanillic acid dose-dependently inhibited VEGF and EPO protein expressions and disrupted tube formation. The results suggest that vanillic acid effectively inhibits angiogenesis. Flow cytometry analysis demonstrated that vanillic acid significantly induced G1 phase arrest and inhibited the proliferation of human colon cancer HCT116 cells. In vivo experiments confirmed that vanillic acid treatment caused significant inhibition of tumor growth in a xenografted tumor model. These studies reveal that vanillic acid is an effective inhibitor of HIF-1α and provides new perspectives into the mechanism of its antitumor activity.

Vandetanib (ZD6474) induces antiangiogenesis through mTOR-HIF-1 alpha-VEGF signaling axis in breast cancer cells

Objective

Vandetanib, also known as ZD6474, has recently been proved to be a clinical drug for cancer by targeting vascular endothelial growth factor receptor 2 (VEGFR2), EGFR, and RET tyrosine kinases. We hypothesized that vandetanib will be a drug candidate for breast cancer treatment by targeting angiogenesis.

Materials and methods

Vandetanib was used to treat different breast cancer cell lines, and its effect on growth, apoptosis, and cell cycle was studied by MTT assay and flow cytometry. VEGF level in culture medium was measured by ELISA. Gene expression of mechanistic target of rapamycin (mTOR), hypoxia-inducible factor (HIF)-1 alpha, and VEGF at mRNA and protein level were analyzed by quantitative real-time-PCR and Western blot. The cellular behavior variations were investigated by using wound healing assay, transwell invasion assay, and tubular formation assay as well as experiments in vivo.

Result

We found that vandetanib can inhibit breast cancer cell line growth via apoptosis and cell cycle regulation. VEGF secretion decreases upon treatment. Vandetanib can reduce both mRNA and protein level of mTOR, HIF-1 alpha, and VEGF. Angiogenesis assays showed that vandetanib can inhibit wound healing, invasion, and tubular formation in culture. Furthermore, vandetanib inhibited the growth of breast tumor in vivo.

Conclusion

In short, our study showed that vandetanib can control angiogenesis of breast cancer in culture via mTOR, HIF-1 alpha, and VEGF signaling pathway.

Dauricine upregulates the chemosensitivity of hepatocellular carcinoma cells: Role of repressing glycolysis via miR-199a:HK2/PKM2 modulation

Dauricine (Dau) is a natural alkaloid exhibiting anti-proliferative activity against several different types of malignant cell. However, effects of Dau on hepatocellular carcinoma (HCC) cells and the underlying molecular mechanisms have remained to be fully elucidated. In this study, we found that Dau elevated the sensitivities of HCC cells to chemotherapeutic reagents, including cisplatin, sorafenib, and isoliensinine. Moreover, Dau promoted apoptosis of HCC cells triggered by these chemotherapeutic reagents. Consistently, in a xenograft mouse model, Dau sensitized HCC cells to sorafenib. In HCC cells, Dau dose-dependently inhibited glucose glycolysis and increased oxidative phosphorylation. Mechanistically, Dau downregulated the expression of hexokinase 2 (HK2) and pyruvate kinase M2 (PKM2). HK2 and PKM2 can be directly targeted by miR-199a. Dau dose-dependently increased miR-199a expression in HCC cells. Transfection of anti-miR-199a abrogated Dau-mediated suppression of HK2 and PKM2. Dau-induced metabolic shift was thereby severely crippled by anti-miR-199a. In addition, the incremental activity of Dau on sorafenib sensitivity of HCC cells was diminished in response to the transfection of anti-miR-199a. Taken together, our findings provided novel insights into the impact of Dau on HCC cells and supported considering Dau as an adjuvant reagent in the clinical treatment of HCC.

Pharmacokinetic and excretion study of three alkaloids in rats using UPLC-MS/MS after oral administration of menispermi rhizoma capsules

A sensitive, specific and rapid ultra-performance liquid chromatography tandem mass spectrometry method (UPLC-MS/MS) was developed for simultaneous determination of three main alkaloids (daucicoline, daurisoline, dauricine) in rat plasma, urine and feces after oral administration of menispermi rhizoma capsules. The chromatographic separation was performed on a Waters ACQUITY UPLC® BEH C₁₈ column (50 mm × 2.1 mm, id, 1.7 μm) with a column temperature of 30 °C and a linear gradient elution using a mobile phase consisting of 0.1% formic acid and acetonitrile. The flow rate was set at 0.3 mL min⁻¹, and the total run time was 10 min. The detection was performed, without interference, using positive electrospray ionization with a multiple reaction monitoring mode. A comprehensive validation of the method was performed. The linearity of the analytical response was good over a wide concentration range with correlation coefficients greater than 0.9903 and the lower limits of quantification were 1.5–5.0 ng mL⁻¹ for all matrices. Both accuracy and precision of the assay were satisfactory. The mean extraction recoveries of analytes and internal standard from rat plasma, urine and feces were all more than 78.3%. The validated methods of the three types of substrates were successfully applied to a pharmacokinetic and excretion study of the three alkaloids in rats after oral administration of menispermi rhizoma capsule. The pharmacokinetics and excretion study of these active components in menispermi rhizoma capsule have not been reported. The results provided a meaningful basis for the clinical application of menispermi rhizoma capsule.

A sensitive, specific and rapid UPLC-MS/MS was developed for simultaneous determination of three main alkaloids (daucicoline, daurisoline, dauricine) in rat plasma, urine and feces after oral administration of menispermi rhizoma capsules.

Crosstalk between Notch, HIF-1α and GPER in Breast Cancer EMT

The Notch signaling pathway acts in both physiological and pathological conditions, including embryonic development and tumorigenesis. In cancer progression, diverse mechanisms are involved in Notch-mediated biological responses, including angiogenesis and epithelial-mesenchymal-transition (EMT). During EMT, the activation of cellular programs facilitated by transcriptional repressors results in epithelial cells losing their differentiated features, like cell–cell adhesion and apical–basal polarity, whereas they gain motility. As it concerns cancer epithelial cells, EMT may be consequent to the evolution of genetic/epigenetic instability, or triggered by factors that can act within the tumor microenvironment. Following a description of the Notch signaling pathway and its major regulatory nodes, we focus on studies that have given insights into the functional interaction between Notch signaling and either hypoxia or estrogen in breast cancer cells, with a particular focus on EMT. Furthermore, we describe the role of hypoxia signaling in breast cancer cells and discuss recent evidence regarding a functional interaction between HIF-1α and GPER in both breast cancer cells and cancer-associated fibroblasts (CAFs). On the basis of these studies, we propose that a functional network between HIF-1α, GPER and Notch may integrate tumor microenvironmental cues to induce robust EMT in cancer cells. Further investigations are required in order to better understand how hypoxia and estrogen signaling may converge on Notch-mediated EMT within the context of the stroma and tumor cells interaction. However, the data discussed here may anticipate the potential benefits of further pharmacological strategies targeting breast cancer progression.

Dauricine combined with clindamycin inhibits severe pneumonia co-infected by influenza virus H5N1 and Streptococcus pneumoniae in vitro and in vivo through NF-κB signaling pathway

Dauricine, isolated from Menispermum dauricum, has been widely used for treatment of various diseases, including cardiac ischemia and inflammation-related diseases. However, little is known regarding to the effect of dauricine on severe pneumonia. Therefore, the aim was to investigate the effect of dauricine on severe pneumonia and its mechanism during progress. Herein, H5N1 and Streptococcus pneumoniae (D39) were conducted to induce severe pneumonia in both BEAS-2B cells and mice. In vitro, dauricine reversed the protein and mRNA expressions of TNF-α, IL-6 and IL-1β, examined by ELISA and qRT-PCR assay, respectively. In addition, the nuclear translocation of NF-κB/p65 and the phosphorylation expressions of IκBα and IKKα/β, examined by western blotting, were dose-dependently dropped by dauricine. However, dauricine had no significant effect on MAPKs, including JNK, ERK and p38. In vivo, dauricine significantly decreased MPO activity, the lung wet/dry weight ratio, the protein and mRNA expression of TNF-α, IL-6 and IL-1β, the expressions of NF-κB/p65, and attenuated the lung histological alterations. Besides, compared to dauricine alone, combined with clindamycin had more remarkably effects on severe pneumonia in vitro. Overall, the results suggested that dauricine, a relatively drug that targets NF-κB, in combination with clindamycin, maybe a novel therapeutic strategy for severe pneumonia.

Dauricine inhibits viability and induces cell cycle arrest and apoptosis via inhibiting the PI3K/Akt signaling pathway in renal cell carcinoma cells

Renal cell carcinoma (RCC), which is derived from the proximal tubules of nephrons, is one of the most common solid cancers. Due to its inherent insensitivity to radiotherapy and chemotherapy, surgery remains the only curative strategy for RCC. Therefore, a novel strategy for treating RCC is urgently needed. This study aims to investigate the effects of dauricine, a bisbenzylisoquinoline alkaloid, in RCC cells and the underlying mechanisms of its action. The effects of dauricine on viability, cell cycle distribution and apoptosis in RCC cells were determined in vitro by MTT assay, flow cytometry and nucleosome ELISA assay, respectively. Mechanism studies were performed by analyzing related proteins using western blotting assays. We show that dauricine effectively inhibits the viability of four RCC cell lines (786‑O, Caki‑1, A‑498 and ACHN). In addition, dauricine induces cell cycle arrest at the G0/G1 phase in RCC cells. Dauricine also induces apoptosis via the intrinsic pathway, since caspase‑9 and caspase‑3 but not caspase‑8 activation was detected after the treatment. Moreover, dauricine was able to inhibit the PI3K/Akt signaling pathway. Our findings suggest inhibitory effects of dauricine in renal cancer cells and provide a better understanding of its underlying mechanism. Our findings suggest that dauricine could be a potential therapeutic agent for treating RCC.

GPER mediates the angiocrine actions induced by IGF1 through the HIF-1α/VEGF pathway in the breast tumor microenvironment

BACKGROUND

The G protein estrogen receptor GPER/GPR30 mediates estrogen action in breast cancer cells as well as in breast cancer-associated fibroblasts (CAFs), which are key components of microenvironment driving tumor progression. GPER is a transcriptional target of hypoxia inducible factor 1 alpha (HIF-1α) and activates VEGF expression and angiogenesis in hypoxic breast tumor microenvironment. Furthermore, IGF1/IGF1R signaling, which has angiogenic effects, has been shown to activate GPER in breast cancer cells.

METHODS

We analyzed gene expression data from published studies representing almost 5000 breast cancer patients to investigate whether GPER and IGF1 signaling establish an angiocrine gene signature in breast cancer patients. Next, we used GPER-positive but estrogen receptor (ER)-negative primary CAF cells derived from patient breast tumours and SKBR3 breast cancer cells to investigate the role of GPER in the regulation of VEGF expression and angiogenesis triggered by IGF1. We performed gene expression and promoter studies, western blotting and immunofluorescence analysis, gene silencing strategies and endothelial tube formation assays to evaluate the involvement of the HIF-1α/GPER/VEGF signaling in the biological responses to IGF1.

RESULTS

We first determined that GPER is co-expressed with IGF1R and with the vessel marker CD34 in human breast tumors (n = 4972). Next, we determined that IGF1/IGF1R signaling engages the ERK1/2 and AKT transduction pathways to induce the expression of HIF-1α and its targets GPER and VEGF. We found that a functional cooperation between HIF-1α and GPER is essential for the transcriptional activation of VEGF induced by IGF1. Finally, using conditioned medium from CAFs and SKBR3 cells stimulated with IGF1, we established that HIF-1α and GPER are both required for VEGF-induced human vascular endothelial cell tube formation.

CONCLUSIONS

These findings shed new light on the essential role played by GPER in IGF1/IGF1R signaling that induces breast tumor angiogenesis. Targeting the multifaceted interactions between cancer cells and tumor microenvironment involving both GPCRs and growth factor receptors has potential in future combination anticancer therapies.

N-Desmethyldauricine Induces Autophagic Cell Death in Apoptosis-Defective Cells via Ca2+ Mobilization

Resistance of cancer cells to chemotherapy remains a significant problem in oncology. Mechanisms regulating programmed cell death, including apoptosis, autophagy or necrosis, in the treatment of cancers have been extensively investigated over the last few decades. Autophagy is now emerging as an important pathway in regulating cell death or survival in cancer therapy. Recent studies demonstrated variety of natural small-molecules could induce autophagic cell death in apoptosis-resistant cancer cells, therefore, discovery of novel autophagic enhancers from natural products could be a promising strategy for treatment of chemotherapy-resistant cancer. By computational virtual docking analysis, biochemical assays, and advanced live-cell imaging techniques, we have identified N-desmethyldauricine (LP-4), isolated from rhizoma of Menispermum dauricum DC as a novel inducer of autophagy. LP-4 was shown to induce autophagy via the Ulk-1-PERK and Ca²⁺/Calmodulin-dependent protein kinase kinase β (CaMKKβ)-AMPK-mTOR signaling cascades, via mobilizing calcium release through inhibition of SERCA, and importantly, lead to autophagic cell death in a panel of cancer cells, apoptosis-defective and apoptosis-resistant cells. Taken together, this study provides detailed insights into the cytotoxic mechanism of a novel autophagic compound that targeting the apoptosis resistant cancer cells, and new implication on drug discovery from natural products for drug resistant cancer therapy.

microRNA-454 shows anti-angiogenic and anti-metastatic activity in pancreatic ductal adenocarcinoma by targeting LRP6

Our previous work has shown that microRNA-454 (miR-454) can inhibit the growth of pancreatic ductal adenocarcinoma (PDAC) by blocking the recruitment of bone marrow-derived macrophages. In the present study, we aimed to explore its role in the proliferation, invasion, and pro-angiogenic activity of PDAC cells in vitro and lung metastasis in vivo. PANC-1 and MiaPaCa-2 cells were transfected with a miR-454-expressing plasmid and tested for cell proliferation, colony formation, cell cycle distribution, invasion, and pro-angiogenic activity. The target gene(s) that mediated the action of miR-454 was identified. The effect of miR-454 overexpression on lung metastasis of PDAC was evaluated in nude mice. Of note, overexpression of miR-454 significantly inhibited PDAC cell proliferation and colony formation and arrests PDAC cells at the G2/M phase. Decreased invasiveness was observed in miR-454-overexpressing PDAC cells. Conditioned media from miR-454-overexpressing PANC-1 cells contained lower levels of vascular endothelial growth factor and had reduced capacity to induce endothelial cell tube-like structure formation. Mechanistically, miR-454 was found to target the mRNA of LRP6 and inhibit the activation of Wnt/β-catenin signaling in PDAC cells. Ectopic expression of LRP6 significantly reversed the suppressive effects of miR-454 on PDAC cells. In vivo studies confirmed that miR-454-overexpressing PANC-1 cells formed significantly less lung metastases than control cells. Altogether, miR-454 functions as a suppressor in tumor growth, angiogenesis, and metastasis in PDAC, likely through downregulation of LRP6.

Roles of PI3K/Akt and c-Jun signaling pathways in human papillomavirus type 16 oncoprotein-induced HIF-1α, VEGF, and IL-8 expression and in vitro angiogenesis in non-small cell lung cancer cells

Background and Objectives

Human papillomavirus (HPV)-16 infection may be related to non-smoking associated lung cancer. Our previous studies have found that HPV-16 oncoproteins promoted angiogenesis via enhancing hypoxia-inducible factor-1α (HIF-1α), vascular endothelial growth factor (VEGF), and interleukin-8 (IL-8) expression in non-small cell lung cancer (NSCLC) cells. In this study, we further investigated the roles of PI3K/Akt and c-Jun signaling pathways in it.

Methods

Human NSCLC cell lines, A549 and NCI-H460, were stably transfected with pEGFP-16 E6 or E7 plasmids. Western blotting was performed to analyze the expression of HIF-1α, p-Akt, p-P70S6K, p-P85S6K, p-mTOR, p-JNK, and p-c-Jun proteins. VEGF and IL-8 protein secretion and mRNA levels were determined by ELISA and Real-time PCR, respectively. The invitro angiogenesis was observed by human umbilical vein endothelial cells (HUVECs) tube formation assay. Co-immunoprecipitation was performed to analyze the interaction between c-Jun and HIF-1α.

Results

HPV-16 E6 and E7 oncoproteins promoted the activation of Akt, P70S6K, P85S6K, mTOR, JNK, and c-Jun. LY294002, a PI3K inhibitor, inhibited HPV-16 oncoprotein-induced activation of Akt, P70S6K, and P85S6K, expression of HIF-1α, VEGF, and IL-8, and invitro angiogenesis. c-Jun knockdown by specific siRNA abolished HPV-16 oncoprotein-induced HIF-1α, VEGF, and IL-8 expression and invitro angiogenesis. Additionally, HPV-16 oncoproteins promoted HIF-1α protein stability via blocking proteasome degradation pathway, but c-Jun knockdown abrogated this effect. Furthermore, HPV-16 oncoproteins increased the quantity of c-Jun binding to HIF-1α.

Conclusions

PI3K/Akt signaling pathway and c-Jun are involved in HPV-16 oncoprotein-induced HIF-1α, VEGF, and IL-8 expression and invitro angiogenesis. Moreover, HPV-16 oncoproteins promoted HIF-1α protein stability possibly through enhancing the interaction between c-Jun and HIF-1α, thus making a contribution to angiogenesis in NSCLC cells.

Pharmacological Activities of Sijunzi Decoction Which Are Related to Its Antioxidant Properties

This paper introduces the antioxidant constituents and pharmacological effects of Sijunzi decoction by looking up literatures in recent years. Sijunzi decoction is composed of Ginseng, Atractylodes, Tuckahoe, and Glycyrrhiza. The antioxidant ingredients of Sijunzi decoction include paeonol, dauricine, naringin, and isoliquiritigenin. The study has proved that it possesses wide pharmacological effects of anticardiovascular diseases, antinervous system disease, antidiabetes, antimetabolic syndrome, and antitumor. Research on the antioxidant components of Sijunzi decoction and their targets is a promising study area in the future.

Epigallocatechin-3-gallate inhibits IGF-I-stimulated lung cancer angiogenesis through downregulation of HIF-1α and VEGF expression

BACKGROUND/AIMS

Numerous studies have shown that epigallocatechin-3-gallate (EGCG), a polyphenol component extracted from green tea, can inhibit the growth and induce apoptosis of various types of human tumor cells. In this study, we evaluated the inhibitory effects of EGCG on the proangiogenic capabilities of A549 cells.

METHODS

A549 cells starved in serum-free culture medium for 24 h were pretreated with EGCG at various concentrations (0, 10, 25, 50, and 100 μmol/l) for 1 h, followed by the addition of insulin-like growth factor-I (IGF-I) at the final concentration of 40 ng/ml and continued culturing for an additional 16 h. The in vitro angiogenesis analyzing test kit with ECMatrix™ gel was used to detect the formation of capillary tube-like structures. The mRNA expression of hypoxia-inducible factor-1α (HIF-1α) and vascular endothelial growth factor (VEGF) was determined by real-time PCR. The protein expression of HIF-1α and VEGF was detected by Western blotting and ELISA, respectively.

RESULTS

EGCG significantly inhibited the formation of capillary tube-like structures on the surface of ECMatrix induced by IGF-I both in vitro and in vivo and reduced the level of hemoglobin in Matrigel plugs. In addition, EGCG was shown to significantly inhibit the IGF-I-induced upregulation of HIF-1α protein expression. Meanwhile, EGCG at the concentration of 25 and 100 μmol/l exhibited obvious inhibitory effects on IGF-I-induced VEGF expression (p < 0.01).

CONCLUSION

Our results suggest that EGCG has potent inhibitory effects on tumor angiogenesis induced by IGF-I in human non-small cell lung cancer cells, which may possibly contribute to the downregulation of HIF-1α and VEGF expression.

Leucine zipper tumor suppressor 2 inhibits cell proliferation and regulates Lef/Tcf-dependent transcription through Akt/GSK3β signaling pathway in lung cancer

Leucine zipper tumor suppressor 2 (LZTS2) is implicated in several cancers; however, its biological mechanisms in non-small cell lung cancer (NSCLC) are not yet understood. We found that low levels of LZTS2 in NSCLC were correlated with tumor and nodal status. LZTS2 could inhibit cell proliferation and cell cycle transition at the G1/S phase and was implicated in the regulation of proteins associated with the canonical Wnt pathway, including GSK3β and β-catenin through inactivating the Akt pathway. These results provide novel mechanistic insight into the biological roles of LZTS2 in lung cancer cells.

Functional analysis of B7-H3 in colonic carcinoma cells

B7-H3 is a newly discovered member of the B7/CD28 superfamily which functions as an important T-cell immune molecule. It has been reported recently that B7-H3 is highly expressed in many cancer cells, the data indicating that it may be a regulation factor contributing to tumor-resistance. In our study, we used bioinformatics to identify differentially expressed genes between colonic cancer cells and normal colonic cells, aiming to analyze mechanisms and identify sub-pathways closely related to progression, with the final aim of finding small molecule drugs which might interfere this progression. We found that ajmaline is one related factor which may enhance self-immunity in colon carcinoma therapy and B7-H3 plays important roles with regard to immunoreactions of colonic cancer cells. All the results indicate that H7-B3 is a favorable prognostic biomarker for colon carcinomas, providing novel information regarding likely targets for intervention.

Anticancer drugs from traditional toxic Chinese medicines

Many anticancer drugs are obtained from natural sources. Nature produces a variety of toxic compounds, which are often used as anticancer drugs. Up to now, there are at least 120 species of poisonous botanicals, animals and minerals, of which more than half have been found to possess significant anticancer properties. In spite of their clinical toxicity, they exhibit pharmacological effects and have been used as important traditional Chinese medicines for the different stages of cancer. The article reviews many structures such as alkaloids of Camptotheca acuminata, Catharanthus roseus and Cephalotaxus fortunei, lignans of Dysosma versipellis and Podophyllum emodi, ketones of Garcinia hanburyi, terpenoids of Mylabris and Ginkgo biloba, diterpenoids of Tripterygium wilfordii, Euphorbia fischeriana, Euphorbia lathyris, Euphorbia kansui, Daphne genkwa, Pseudolarix kaempferi and Brucea javanica, triterpenoids of Melia toosendan, steroids of Periploca sepium, Paris polyphylla and Venenum Bufonis, and arsenic compounds including Arsenicum and Realgar. By comparing their related phytochemistry, toxic effects and the recent advances in understanding the mechanisms of action, this review puts forward some ideals and examples about how to increase antitumour activity and/or reduce the side effects experienced with Chinese medicine.

Liquiritigenin inhibits serum-induced HIF-1α and VEGF expression via the AKT/mTOR-p70S6K signalling pathway in HeLa cells

Liquiritigenin (LQ) is a non-toxic dietary flavonoid with chemopreventive and anticancer properties. However, the mechanism of its antiangiogenesis remains unclear. Hypoxia-inducible factor-1α (HIF-1α) and its downstream target, vascular endothelial growth factor (VEGF), play a critical role in tumour angiogenesis and represent an attractive chemotherapeutic target. In this study, we investigated the effect of LQ on the molecular mechanism of angiogenesis. We found that LQ inhibited VEGF expression at both mRNA and protein levels. Liquiritigenin did not affect HIF-1α expression at the mRNA level, but it dramatically inhibited both serum- and mimicked hypoxic-induced HIF-1α protein accumulation in HeLa cells. Furthermore, we showed that LQ inhibited serum-induced expression of HIF-1α by reducing its stability and decreased the synthesis in a dose-dependent manner. Mechanistically, we demonstrated that LQ inhibited HIF-1α and VEGF expression involved in blocking the protein kinase B (PKB/Akt) signalling pathway, and the mechanisms correlated with dephosphorylation of the mammalian target of rapamycin (mTOR) and its effector ribosomal protein S6 kinase (p70S6K). In addition, LQ inhibited VEGF-induced formation of capillary-like structures in human umbilical vein endothelial cells (HUVEC). Taken together, our study provided valuable insights into the mechanism of antiangiogenic effect of LQ.

Increased accumulation of hypoxia-inducible factor-1α with reduced transcriptional activity mediates the antitumor effect of triptolide

Background

Hypoxia-inducible factor-1α (HIF-1α), a critical transcription factor to reduced O₂ availability, has been demonstrated to be extensively involved in tumor survival, aggressive progression, drug resistance and angiogenesis. Thus it has been considered as a potential anticancer target. Triptolide is the main principle responsible for the biological activities of the Traditional Chinese Medicine tripterygium wilfordii Hook F. Triptolide possesses great chemotherapy potential for cancer with its broad-spectrum anticancer, antiangiogenesis, and drug-resistance circumvention activities. Numerous biological molecules inhibited by triptolide have been viewed as its possible targets. However, the anticancer action mechanisms of triptolide remains to be further investigated. Here we used human ovarian SKOV-3 cancer cells as a model to probe the effect of triptolide on HIF-1α.

Results

Triptolide was observed to inhibit the proliferation of SKOV-3 cells, and meanwhile, to enhance the accumulation of HIF-1α protein in SKOV-3, A549 and DU145 cells under different conditions. Triptolide did not change the kinetics or nuclear localization of HIF-1α protein or the 26 S proteasome activity in SKOV-3 cells. However, triptolide was found to increase the levels of HIF-1α mRNA. Unexpectedly, the HIF-1α protein induced by triptolide appeared to lose its transcriptional activity, as evidenced by the decreased mRNA levels of its target genes including VEGF, BNIP3 and CAIX. The results were further strengthened by the lowered secretion of VEGF protein, the reduced sprout outgrowth from the rat aorta rings and the inhibitory expression of the hypoxia responsive element-driven luciferase reporter gene. Moreover, the silencing of HIF-1α partially prevented the cytotoxicity and apoptosis triggered by triptolide.

Conclusions

The potent induction of HIF-1α protein involved in its cytotoxicity, together with the suppression of HIF-1 transcriptional activity, indicates the great therapeutic potential of triptolide as an anticancer drug. Meanwhile, our data further stress the possibility that HIF-1α functions in an unresolved nature or condition.