Activation of AMPK by simvastatin inhibited breast tumor angiogenesis via impeding HIF-1α-induced pro-angiogenic factor

The potential of vascular normalization for sensitization to radiotherapy

Radiotherapy causes apoptosis mainly through direct or indirect damage to DNA via ionizing radiation, leading to DNA strand breaks. However, the efficacy of radiotherapy is attenuated in malignant tumor microenvironment (TME), such as hypoxia. Tumor vasculature, due to the imbalance of various angiogenic and anti-angiogenic factors, leads to irregular morphology of tumor neovasculature, disordered arrangement of endothelial cells, and too little peripheral coverage. This ultimately leads to a TME characterized by hypoxia, low pH and high interstitial pressure. This deleterious TME further exacerbates the adverse effects of tumor neovascularization and weakens the efficacy of conventional radiotherapy. Whereas normalization of blood vessels improves TME and thus the efficacy of radiotherapy. In addition to describing the research progress of radiotherapy sensitization and vascular normalization, this review focuses on the strategy and application prospect of modulating vascular normalization to improve the efficacy of radiotherapy sensitization.

Shear Stress-Induced AMP-Activated Protein Kinase Modulation in Endothelial Cells: Its Role in Metabolic Adaptions and Cardiovascular Disease

Endothelial cells (ECs) line the inner surface of all blood vessels and form a barrier that facilitates the controlled transfer of nutrients and oxygen from the circulatory system to surrounding tissues. Exposed to both laminar and turbulent blood flow, ECs are continuously subject to differential mechanical stimulation. It has been well established that the shear stress associated with laminar flow (LF) is atheroprotective, while shear stress in areas with turbulent flow (TF) correlates with EC dysfunction. Moreover, ECs show metabolic adaptions to physiological changes, such as metabolic shifts from quiescence to a proliferative state during angiogenesis. The AMP-activated protein kinase (AMPK) is at the center of these phenomena. AMPK has a central role as a metabolic sensor in several cell types. Moreover, in ECs, AMPK is mechanosensitive, linking mechanosensation with metabolic adaptions. Finally, recent studies indicate that AMPK dysregulation is at the center of cardiovascular disease (CVD) and that pharmacological targeting of AMPK is a promising and novel strategy to treat CVDs such as atherosclerosis or ischemic injury. In this review, we summarize the current knowledge relevant to this topic, with a focus on shear stress-induced AMPK modulation and its consequences for vascular health and disease.

Simvastatin Overcomes Resistance to Tyrosine Kinase Inhibitors in Patient-derived, Oncogene-driven Lung Adenocarcinoma Models

There is an unmet clinical need to develop novel strategies to overcome resistance to tyrosine kinase inhibitors (TKI) in patients with oncogene-driven lung adenocarcinoma (LUAD). The objective of this study was to determine whether simvastatin could overcome TKI resistance using the in vitro and in vivo LUAD models. Human LUAD cell lines, tumor cells, and patient-derived xenograft (PDX) models from TKI-resistant LUAD were treated with simvastatin, either alone or in combination with a matched TKI. Tumor growth inhibition was measured by the 3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium (MTS) assay and expression of molecular targets was assessed by immunoblots. Tumors were assessed by histopathology, IHC stain, immunoblots, and RNA sequencing. We found that simvastatin had a potent antitumor effect in tested LUAD cell lines and PDX tumors, regardless of tumor genotypes. Simvastatin and TKI combination did not have antagonistic cytotoxicity in these LUAD models. In an osimertinib-resistant LUAD PDX model, simvastatin and osimertinib combination resulted in a greater reduction in tumor volume than simvastatin alone (P < 0.001). Immunoblots and IHC stain also confirmed that simvastatin inhibited TKI targets. In addition to inhibiting 3-hydroxy-3-methyl-glutaryl-CoA (HMG-CoA) reductase, RNA sequencing and Western blots identified the proliferation, migration, and invasion-related genes (such as PI3K/Akt/mTOR, YAP/TAZ, focal adhesion, extracellular matrix receptor), proteasome-related genes, and integrin (α3β1, αvβ3) signaling pathways as the significantly downregulated targets in these PDX tumors treated with simvastatin and a TKI. The addition of simvastatin is a safe approach to overcome acquired resistance to TKIs in several oncogene-driven LUAD models, which deserve further investigation.

Plasmid co-expressing siRNA-PD-1 and Endostatin carried by attenuated Salmonella enhanced the anti-melanoma effect via inhibiting the expression of PD-1 and VEGF on tumor-bearing mice

Melanoma, the most perilous form of skin cancer, is known for its inherent resistance to chemotherapy. Even with advances in tumor immunotherapy, the survival of patients with advanced or recurrent melanomas remains poor. Over time, melanoma tumor cells may produce excessive angiogenic factors, necessitating the use of combinations of angiogenesis inhibitors, including broad-spectrum options, to combat melanoma. Among these inhibitors, Endostatin is one of the most broad-spectrum and least toxic angiogenesis inhibitors. We found Endostatin significantly increased the infiltration of CD8+ T cells and reduced the infiltration of M2 tumor-associated macrophages (TAMs) in the melanoma tumor microenvironment (TME). Interestingly, we also observed high expression levels of programmed death 1 (PD-1), an essential immune checkpoint molecule associated with tumor immune evasion, within the melanoma tumor microenvironment despite the use of Endostatin. To address this issue, we investigated the effects of a plasmid expressing Endostatin and PD-1 siRNA, wherein Endostatin was overexpressed while RNA interference (RNAi) targeted PD-1. These therapeutic agents were delivered using attenuated Salmonella in melanoma-bearing mice. Our results demonstrate that pEndostatin-siRNA-PD-1 therapy exhibits optimal therapeutic efficacy against melanoma. We found that pEndostatin-siRNA-PD-1 therapy promotes the infiltration of CD8+ T cells and the expression of granzyme B in melanoma tumors. Importantly, combined inhibition of angiogenesis and PD-1 significantly suppresses melanoma tumor progression compared with the inhibition of angiogenesis or PD-1 alone. Based on these findings, our study suggests that combining PD-1 inhibition with angiogenesis inhibitors holds promise as a clinical strategy for the treatment of melanoma.

Potential antitumour effect of all-trans retinoic acid on regorafenib-treated human colon cancer cell lines

Introduction

Colorectal cancer (CRC) is a significant contributor to cancer-related mortality worldwide, ranking as the second leading cause of such deaths. Central to the progression of this malignancy is angiogenesis - a complex process orchestrated by vascular endothelial growth factor (VEGF). Regorafenib, a potent multikinase inhibitor, acts as a critical antagonist of multiple kinases involved in angiogenesis, proliferation, and metastasis. Conversely, all-trans retinoic acid (ATRA) has demonstrated compelling antitumour effects across various cancer types. This study aims to comprehensively evaluate the combined antitumour potential of ATRA and regorafenib in human colon cancer cell lines while elucidating the intricate molecular mechanisms that underlie their action.

Material and methods

Our investigative approach involved an enzyme-linked immunosorbent assay to meticulously analyse the levels of key players in the VEGF signalling pathway, including VEGF itself, activated protein kinase (AMPK), extracellular signal-regulated protein kinase 1 (ERK1), and nuclear factor kappa B (NF-κB). Additionally, we assessed caspase-3 activity as a fundamental marker of apoptosis.

Results

The combined use of ATRA and regorafenib exhibited a remarkable augmentation in both AMPK and caspase-3 activities. This was accompanied by a significant reduction in VEGF, ERK1, and NF-κB levels within human colon cancer cell lines subjected to regorafenib treatment.

Conclusions

Our findings underscore the remarkable antiproliferative, antiangiogenic, and proapoptotic effects resulting from the combined use of ATRA and regorafenib in the context of CRC. This modulation of tumourigenic processes is predominantly mediated through the VEGF signalling axis.

An In Vivo Dual-Observation Method to Monitor Tumor Mass and Tumor-Surface Blood Vessels for Developing Anti-Angiogenesis Agents against Submillimeter Tumors

Managing metastasis at the early stage and detecting and treating submillimeter tumors at early metastasis are crucial for improving cancer prognosis. Angiogenesis is a critical target for developing drugs to detect and inhibit submillimeter tumor growth; however, drug development remains challenging because there are no suitable models for observing the submillimeter tumor mass and the surrounding blood vessels in vivo. We have established a xenograft subcutaneous submillimeter tumor mouse model with HT-29-RFP by transplanting a single spheroid grown on radiation-crosslinked gelatin hydrogel microwells. Here, we developed an in vivo dual-observation method to observe the submillimeter tumor mass and tumor-surface blood vessels using this model. RFP was detected to observe the tumor mass, and a fluorescent angiography agent FITC-dextran was administered to observe blood vessels via stereoscopic fluorescence microscopy. The anti-angiogenesis agent regorafenib was used to confirm the usefulness of this method. This method effectively detected the submillimeter tumor mass and tumor-surface blood vessels in vivo. Regorafenib treatment revealed tumor growth inhibition and angiogenesis downregulation with reduced vascular extremities, segments, and meshes. Further, we confirmed that tumor-surface blood vessel areas monitored using in vivo dual-observation correlated with intratumoral blood vessel areas observed via fluorescence microscopy with frozen sections. In conclusion, this method would be useful in developing anti-angiogenesis agents against submillimeter tumors.

Angiogenesis induction as a key step in cardiac tissue Regeneration: From angiogenic agents to biomaterials

Cardiovascular diseases are the leading cause of death worldwide. After myocardial infarction, the vascular supply of the heart is damaged or blocked, leading to the formation of scar tissue, followed by several cardiac dysfunctions or even death. In this regard, induction of angiogenesis is considered as a vital process for supplying nutrients and oxygen to the cells in cardiac tissue engineering. The current review aims to summarize different approaches of angiogenesis induction for effective cardiac tissue repair. Accordingly, a comprehensive classification of induction of pro-angiogenic signaling pathways through using engineered biomaterials, drugs, angiogenic factors, as well as combinatorial approaches is introduced as a potential platform for cardiac regeneration application. The angiogenic induction for cardiac repair can enhance patient treatment outcomes and generate economic prospects for the biomedical industry. The development and commercialization of angiogenesis methods often involves collaboration between academic institutions, research organizations, and biomedical companies.

New insights into the therapeutic potentials of statins in cancer

The widespread clinical use of statins has contributed to significant reductions of cardiovascular morbidity and mortality. Increasing preclinical and epidemiological evidences have revealed that dyslipidemia is an important risk factor for carcinogenesis, invasion and metastasis, and that statins as powerful inhibitor of HMG-CoA reductase can exert prevention and intervention effects on cancers, and promote sensitivity to anti-cancer drugs. The anti-cancer mechanisms of statins include not only inhibition of cholesterol biosynthesis, but also their pleiotropic effects in modulating angiogenesis, apoptosis, autophagy, tumor metastasis, and tumor microenvironment. Moreover, recent clinical studies have provided growing insights into the therapeutic potentials of statins and the feasibility of combining statins with other anti-cancer agents. Here, we provide an updated review on the application potential of statins in cancer prevention and treatment and summarize the underneath mechanisms, with focuses on data from clinical studies.

Atorvastatin shows antitumor effect in hepatocellular carcinoma development by inhibiting angiogenesis via TGF-β1/pERK signaling pathway

Hepatocellular carcinoma (HCC) represents 90% of liver tumors. Statins may reduce HCC incidence. Its antitumor activities may be mediated by disrupting several hepatocarcinogenic pathways. To evaluate in vivo and in vitro the antiproliferative and antiangiogenic action of atorvastatin (AT) in the development of HCC as well as its mechanisms of action. In vivo model: hexachlorobenzene (HCB) was used to promote the development of HCC in Balb/C nude mice. Number of hepatic tumor, liver cell proliferation parameters (proliferating cell nuclear antigen, PCNA), angiogenesis, and VEGF levels were analyzed. In vitro model: Hep-G2 and Ea-hy926 cells were used to evaluate the effect of different doses of AT on HCB induced cell proliferation, migration, and vasculogenesis and to analyze proliferative parameters. In vivo: AT prevented liver growth and tumor development and inhibited PCNA, TGF-β1, and pERK levels increase. AT prevented skin blood vessel formation. In vitro, AT prevented cell proliferation and migration as well as tubular formation in the endothelial cell line by inhibiting the MAPK ERK pathway. We were able to demonstrate the potential AT antiproliferative and antiangiogenic effects in an HCC model and the involvement of TGF-β1 and pERK pathways.

Overcoming chemoresistance in non-angiogenic colorectal cancer by metformin via inhibiting endothelial apoptosis and vascular immaturity

The development of chemoresistance which results in a poor prognosis often renders current treatments for colorectal cancer (CRC). In this study, we identified reduced microvessel density (MVD) and vascular immaturity resulting from endothelial apoptosis as therapeutic targets for overcoming chemoresistance. We focused on the effect of metformin on MVD, vascular maturity, and endothelial apoptosis of CRCs with a non-angiogenic phenotype, and further investigated its effect in overcoming chemoresistance. In situ transplanted cancer models were established to compare MVD, endothelial apoptosis and vascular maturity, and function in tumors from metformin- and vehicle-treated mice. An in vitro co-culture system was used to observe the effects of metformin on tumor cell-induced endothelial apoptosis. Transcriptome sequencing was performed for genetic screening. Non-angiogenic CRC developed independently of angiogenesis and was characterized by vascular leakage, immaturity, reduced MVD, and non-hypoxia. This phenomenon had also been observed in human CRC. Furthermore, non-angiogenic CRCs showed a worse response to chemotherapeutic drugs in vivo than in vitro. By suppressing endothelial apoptosis, metformin sensitized non-angiogenic CRCs to chemo-drugs via elevation of MVD and improvement of vascular maturity. Further results showed that endothelial apoptosis was induced by tumor cells via activation of caspase signaling, which was abrogated by metformin administration. These findings provide pre-clinical evidence for the involvement of endothelial apoptosis and subsequent vascular immaturity in the chemoresistance of non-angiogenic CRC. By suppressing endothelial apoptosis, metformin restores vascular maturity and function and sensitizes CRC to chemotherapeutic drugs via a vascular mechanism.

Simvastatin Enhanced Anti-tumor Effects of Bevacizumab against Lung Adenocarcinoma A549 Cells via Abating HIF-1α-Wnt/β-Catenin Signaling Pathway

BACKGROUND

Bevacizumab increased hypoxia-inducible factor (HIF-1α) expression attenuates its antitumor effect. Simvastatin can reduce the expression of HIF-1α to exert a tumor-suppressive effect in many in vitro experiments. Therefore, this study aimed to determine whether simvastatin could strengthen the anti-tumor activity of bevacizumab in lung adenocarcinoma.

OBJECTIVE

To determine whether simvastatin could strengthen the anti-tumor activity of bevacizumab in lung adenocarcinoma.

METHODS

The changes in the biological behavior of A549 cells treated with different drugs were determined through colony forming assay, Cell Counting Assay-8 (CCK-8), transwell assay, wound healing assay, and flow cytometry. The expressions of pathway-related factors HIF-1α and β-Catenin were determined via qRT-PCR and western blotting. The expressions of proliferation-related proteins, invasion-related proteins, and apoptosis-related proteins were detected by western blotting. In addition, a xenograft non-small cell lung cancer model in nude mice was used to explore in vivo tumor growth.

RESULTS

We found that simvastatin combined with bevacizumab synergistically suppressed the proliferation, migration, and invasion of A549 cells while promoting their apoptosis. As demonstrated by qRT-PCR and western blotting experiments, the bevacizumab group displayed a higher expression of pathway-related factors HIF-1α and β-Catenin than the control groups, however simvastatin group showed the opposite trend. Its combination with bevacizumab induced elevation of HIF-1α and β-catenin expressions. During in vivo experiments, simvastatin inhibited tumor growth, and in comparison, the inhibitory effects of its combination with bevacizumab were stronger.

CONCLUSION

Based on our findings, simvastatin may affect the biological responses of bevacizumab on A549 cells by restraining the HIF-1α-Wnt/β-catenin signaling pathway, thus representing a novel and effective combination therapy that can be potentially applied in a clinical therapy for lung adenocarcinoma.

KLF2 is a clinical diagnostic and treatment biomarker of breast cancer

Background: As a highly prevalent malignancy among women worldwide, breast cancer, remains a critical public health issue necessitating the development of novel therapeutics and biomarkers. Kruppel Like Factor 2 (KLF2), a member of the Kruppel family of transcription factors, has been implicated in various types of cancer due to its diminished expression; however, the potential implications of KLF2 expression in relation to breast cancer progression, prognosis, and therapy remain unclear. Methods: The present study employed the Tumor Immune Estimation Resource (TIMER) and The Human Protein Atlas databases to investigate the expression pattern of KLF2 in pan-cancer. The relationship between KLF2 expression and clinical features or immune infiltration of The Cancer Genome Atlas (TCGA) breast cancer samples was evaluated using Breast Cancer Integrative Platform (BCIP) and TIMER. The expression levels of KLF2 in breast cancer were validated via immunohistochemical staining analysis. Gene Set Enrichment Analysis (GSEA) to study the KLF2-related gene ontology. STRING database was employed to construct a protein-protein interaction (PPI) network of KLF2 in relation to vascular endothelial growth factor A (VEGFA) and hypoxia-inducible factor 1α (HIF1α). The expression of KLF2 following diverse breast cancer therapies was analyzed in the Gene Expression Omnibus (GEO) databases. The expression of KLF2 following treatment with simvastatin was validated via immunofluorescence and western blotting. Results: Our study reveals that KLF2 displays significantly reduced expression in cancerous tissues compared to non-cancerous controls. Patients with low KLF2 expression levels exhibited poor prognosis across multiple cancer types. KLF2 expression levels were found to be reduced in advanced cancer stages and grades, while positively correlated with the expression of estrogen receptor (ER), progesterone receptor (PR), and tumor size in breast cancer. KLF2 expression is associated with diverse immune infiltration cells, and may impact the breast tumor immune microenvironment by regulating dendritic cell activation. Additionally, we observed a negative correlation between KLF2 expression levels and angiogenesis, as well as the expression of VEGFA and HIF1α. Notably, the anticancer drug simvastatin could induce KLF2 expression in both breast cancer. Conclusion: Based on our observations, KLF2 has potential as a diagnostic, prognostic, and therapeutic biomarker for breast cancer.

AMP kinase activation by Omega-3 polyunsaturated fatty acid protects the retina against ischemic insult: An in vitro and in vivo study

PURPOSE

To investigate the possible beneficial effects of omega-3 polyunsaturated fatty acids (ω3-PUFAs) in ischemic retinal angiogenesis and whether AMP-activated protein kinase (AMPK) is involved.

METHODS

Human retinal microvascular endothelial cells (hRMECs) were exposed to dimethyloxalylglycine (DMOG), a hypoxia-inducible factor hydroxylase inhibitor, in the presence or absence of docosahexaenoic acid (DHA) and small interfering RNA (siRNA) for AMPKα for 24 h. Ischemic factors, endothelial mesenchymal transition marker, endothelial barrier integrity, cell migration, and tube formation were evaluated. Neonatal AMPKα₂^-/- and control wild-type (WT) mice were submitted to an oxygen-induced retinopathy (OIR) protocol; their nursing mother mice were either fed ω3-PUFAs or not. In the end, ischemic markers and endothelial cell proliferation were evaluated in neonatal mouse retinal tissue through immunohistochemical or immunofluorescent assays among all studied groups.

RESULTS

Cells exposed to DMOG displayed increased expressions of hypoxic and endothelial mesenchymal transition (vimentin) markers and barrier disarrangement of Zonula Occludens-1 compared to the control, accompanied by increased cellular migration and tube formation (p < 0.05). AMPK activity was significantly decreased. Supplementation with DHA restored the mentioned alterations compared to DMOG (p<0.05). In siRNA_AMPKα-treated cells, the beneficial effects observed with DHA were abolished. DHA upregulated G-protein receptor-120 (GPR120), which promptly increased intracellular levels of calcium (p ≤ 0.001), which consequently increased Calcium/calmodulin-dependent protein kinase kinase β expression (CaMKKβ) thus phosphorylating AMPK^Thr172. AMPKα₂^-/- and wild-type (WT) OIR mice exhibited similar retinal ischemic changes, and the oral supplementation with ω3-PUFA efficiently prevented the noticed ischemic alterations only in WT mice, suggesting that AMPKα₂ is pivotal in the protective effects of ω3-PUFA.

CONCLUSIONS

ω3-PUFAs protect the retina from the effects of ischemic conditions, and this effect occurs via the GPR120-CaMKKβ-AMPK axis. A better understanding of this mechanism might improve the control of pathological angiogenesis in retinal ischemic diseases.

Disorders of cancer metabolism: The therapeutic potential of cannabinoids

Abnormal energy metabolism, as one of the important hallmarks of cancer, was induced by multiple carcinogenic factors and tumor-specific microenvironments. It comprises aerobic glycolysis, de novo lipid biosynthesis, and glutamine-dependent anaplerosis. Considering that metabolic reprogramming provides various nutrients for tumor survival and development, it has been considered a potential target for cancer therapy. Cannabinoids have been shown to exhibit a variety of anticancer activities by unclear mechanisms. This paper first reviews the recent progress of related signaling pathways (reactive oxygen species (ROS), AMP-activated protein kinase (AMPK), mitogen-activated protein kinases (MAPK), phosphoinositide 3-kinase (PI3K), hypoxia-inducible factor-1alpha (HIF-1α), and p53) mediating the reprogramming of cancer metabolism (including glucose metabolism, lipid metabolism, and amino acid metabolism). Then we comprehensively explore the latest discoveries and possible mechanisms of the anticancer effects of cannabinoids through the regulation of the above-mentioned related signaling pathways, to provide new targets and insights for cancer prevention and treatment.

The role of angiogenesis in melanoma: Clinical treatments and future expectations

The incidence of melanoma has increased rapidly over the past few decades, with mortality accounting for more than 75% of all skin cancers. The high metastatic potential of Melanoma is an essential factor in its high mortality. Vascular angiogenic system has been proved to be crucial for the metastasis of melanoma. An in-depth understanding of angiogenesis will be of great benefit to melanoma treatment and may promote the development of melanoma therapies. This review summarizes the recent advances and challenges of anti-angiogenic agents, including monoclonal antibodies, tyrosine kinase inhibitors, human recombinant Endostatin, and traditional Chinese herbal medicine. We hope to provide a better understanding of the mechanisms, clinical research progress, and future research directions of melanoma.

Investigating on the influence mechanism of sausage of sea bass on calcium absorption and transport based on Caco-2 cell monolayer model

A monolayer Caco-2 cell model was established to explore the effects of sea bass sausage digestive juice containing phosphate on calcium ion transport. Differential proteins of Caco-2 cells treated with fish sausage juice were detected and analyzed by gene ontology (GO) functional annotation and kyoto encyclopedia of genes and genomes (KEGG) pathway analyses. Results revealed that after treatment with 0.23 mg/mL digestive juice of perch sausage in vitro, Caco-2 cell viability was the highest at 72 h (99.84%). Additionally, 0.23 mg/mL digestive juice of perch sausage in vitro significantly increased calcium ion transport. The transfer volume was 1.396 μg/well. Fish sausages containing phosphate significantly affected the protein expression levels of Caco-2 cells. Two hundred one differential proteins were detected, including 114 up-regulated and 87 down-regulated proteins. The main differential proteins included P02795, Q9P0W0, Q96PU5, Q9GZT9 and Q5EBL8. The adjustment ratios of the fish sausage group were 0.7485, 1.373, 1.2535, 0.6775, and 0.809, respectively. The pathway analysis showed that phosphate affected calcium ion absorption and transport through the P02795 enrichment pathway. The fish sausage group showed that the immune-related functions of cells were affected. This study expounds the effects of water-retaining agents on the nutritional quality of aquatic products and provides theoretical support for the research and application of surimi products.

Metformin and simvastatin synergistically suppress endothelin 1-induced hypoxia and angiogenesis in multiple cancer types

Multiple cancers have been reported to be associated with angiogenesis and are sensitive to anti-angiogenic therapies. Vascular normalization, by restoring proper tumor perfusion and oxygenation, could limit tumor cell invasiveness and improve the effectiveness of anticancer treatments. However, the underlying anticancer mechanisms of antiangiogenic drugs are still unknown. Metformin (MET) and simvastatin (SVA), two metabolic-related drugs, have been shown to play important roles in modulating the hypoxic tumor microenvironment and angiogenesis. Whether the combination of MET and SVA could exert a more effective antitumor effect than individual treatments has not been examined. The antitumor effect of the synergism of SVA and MET was detected in mouse models, breast cancer patient-derived organoids, and multiple tumor cell lines compared with untreated, SVA, or MET alone. RNA sequencing revealed that the combination of MET and SVA (but not MET or SVA alone) inhibited the expression of endothelin 1 (ET-1), an important regulator of angiogenesis and the hypoxia-related pathway. We demonstrate that the MET and SVA combination showed synergistic effects on inhibiting tumor cell proliferation, promoting apoptosis, alleviating hypoxia, decreasing angiogenesis, and increasing vessel normalization compared with the use of a single agent alone. The MET and SVA combination suppressed ET-1-induced hypoxia-inducible factor 1α expression by increasing prolyl hydroxylase 2 (PHD2) expression. Furthermore, the MET and SVA combination showed a more potent anticancer effect compared with bosentan. Together, our findings suggest the potential application of the MET and SVA combination in antitumor therapy.

Mitochondrial Matrix Protease ClpP Agonists Inhibit Cancer Stem Cell Function in Breast Cancer Cells by Disrupting Mitochondrial Homeostasis

Mitochondria are multifaceted organelles which are important for bioenergetics, biosynthesis and signaling in metazoans. Mitochondrial functions are frequently altered in cancer to promote both the energy and the necessary metabolic intermediates for biosynthesis required for tumor growth. Cancer stem cells (CSCs) contribute to chemotherapy resistance, relapse, and metastasis. Recent studies have shown that while non-stem, bulk cancer cells utilize glycolysis, breast CSCs are more dependent on oxidative phosphorylation (OxPhos) and therefore targeting mitochondria may inhibit CSC function. We previously reported that small molecule ONC201, which is an agonist for the mitochondrial caseinolytic protease (ClpP), induces mitochondrial dysfunction in breast cancer cells. In this study, we report that ClpP agonists inhibit breast cancer cell proliferation and CSC function in vitro and in vivo. Mechanistically, we found that OxPhos inhibition downregulates multiple pathways required for CSC function, such as the mevalonate pathway, YAP, Myc, and the HIF pathway. ClpP agonists showed significantly greater inhibitory effect on CSC functions compared with other mitochondria-targeting drugs. Further studies showed that ClpP agonists deplete NAD(P)+ and NAD(P)H, induce redox imbalance, dysregulate one-carbon metabolism and proline biosynthesis. Downregulation of these pathways by ClpP agonists further contribute to the inhibition of CSC function. In conclusion, ClpP agonists inhibit breast CSC functions by disrupting mitochondrial homeostasis in breast cancer cells and inhibiting multiple pathways critical to CSC function.

Significance

ClpP agonists disrupt mitochondrial homeostasis by activating mitochondrial matrix protease ClpP. We report that ClpP agonists inhibit cell growth and cancer stem cell functions in breast cancer models by modulating multiple metabolic pathways essential to cancer stem cell function.

Pleiotropic properties of statins via angiogenesis modulation in cardiovascular disease

Inhibition of hydroxymethylglutaryl-coenzyme A (HMG-CoA) reductase by statins is affected by inhibiting the active site of the enzyme in a competitive manner. Statins reduce plasma cholesterol by inhibiting its de novo synthesis. In addition, statins impart 'pleiotropic' activities that do not directly relate to their ability to decrease cholesterol. The proangiogenic and antiangiogenic characteristics of statins are among these pleiotropic effects. These angiogenic-modifying properties could offer new therapeutic applications. Statins stimulate or suppress angiogenesis in a biphasic manner. Whereas low doses of statin stimulate angiogenesis, high doses reduce protein prenylation and limit cell development and angiogenesis. In this review, we discuss how statins impact angiogenesis, with a particular focus on angiogenesis in stroke and cardiovascular disease (CVD).

Statins and angiogenesis in non-cardiovascular diseases

Statins inhibit HMG-CoA reductase by competitively inhibiting the active site of the enzyme, thus preventing cholesterol synthesis and reducing the risk of developing cardiovascular disease. Many pleiotropic effects of statins have been demonstrated that can be either related or unrelated to their cholesterol-lowering ability. Among these effects are their proangiogenic and antiangiogenic properties that could offer new therapeutic applications. In this regard, pro- and anti-angiogenic properties of statins have been shown to be dose dependent. Statins also appear to have a variety of non-cardiovascular angiogenic effects in many diseases, some examples being ocular disease, brain disease, cancer, preeclampsia, diabetes and bone disease, which are discussed in this review using reports from in vitro and in vivo investigations.

Atorvastatin Attenuates Radiotherapy-Induced Intestinal Damage through Activation of Autophagy and Antioxidant Effects

Abdominal or pelvic radiotherapy (RT) often results in small intestinal injury, such as apoptosis of epithelial cells and shortening of the villi. Atorvastatin, a 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitor, has many biological effects including cholesterol reduction, protection from cell damage, and autophagy activation. To reduce the extent of radiotherapy- (RT-) induced enteritis, we investigated the protective effects of atorvastatin against RT-induced damage of the intestinal tract. In this study, C57BL/6 mice were randomly distributed into the following groups (n = 8 per group): (1) control group: mice were fed water only, (2) atorvastatin group (Ator): mice were administered atorvastatin, (3) irradiation group (IR): mice received abdominal RT, (4) Ator+IR group: mice received abdominal RT following atorvastatin administration, and (5) Ator+IR+3-MA group: abdominal RT following atorvastatin and 3-methyladenine (an autophagy inhibitor) administration. Based on the assessment of modified Chiu's injury score and villus/crypt ratio, we found that atorvastatin administration significantly reduced intestinal mucosal damage induced by RT. Atorvastatin treatment reduced apoptosis (cleaved caspase-3 and cleaved poly (ADP-ribose) polymerase), DNA damage (γH2AX and 53BP1), oxidative stress (OS, 4-hydroxynonenal), inflammatory molecules (phospho-NF-κB p65 and TGF-β), fibrosis (collagen I and collagen III), barrier leakage (claudin-2 and fluorescein isothiocyanate-dextran), disintegrity (fatty acid-binding protein 2), and dysfunction (lipopolysaccharide) caused by RT in small intestinal tissue. In addition, atorvastatin upregulated the expression of autophagy-active molecules (LC3B), antioxidants (heme oxygenase 1 and thioredoxin 1), and tight junction proteins (occludin and zonula occludens 1). However, the biological functions of atorvastatin in decreasing RT-induced enteritis were reversed after the administration of 3-MA; the function of antioxidant molecules and activity of thioredoxin reductase were independent of autophagy activation. Our results indicate that atorvastatin can effectively relieve RT-induced enteritis through autophagy activation and associated biological functions, including maintaining integrity and function and decreasing apoptosis, DNA damage, inflammation, OS, and fibrosis. It also acts via its antioxidative capabilities.

Orchestrated Action of AMPK Activation and Combined VEGF/PD-1 Blockade with Lipid Metabolic Tunning as Multi-Target Therapeutics against Ovarian Cancers

Ovarian cancer is one of the most lethal gynecological malignancies worldwide, and chemoresistance is a critical obstacle in the clinical management of the disease. Recent studies have suggested that exploiting cancer cell metabolism by applying AMP-activated protein kinase (AMPK)-activating agents and distinctive adjuvant targeted therapies can be a plausible alternative approach in cancer treatment. Therefore, the perspectives about the combination of AMPK activators together with VEGF/PD-1 blockade as a dual-targeted therapy against ovarian cancer were discussed herein. Additionally, ferroptosis, a non-apoptotic regulated cell death triggered by the availability of redox-active iron, have been proposed to be governed by multiple layers of metabolic signalings and can be synergized with immunotherapies. To this end, ferroptosis initiating therapies (FITs) and metabolic rewiring and immunotherapeutic approaches may have substantial clinical potential in combating ovarian cancer development and progression. It is hoped that the viewpoints deliberated in this review would accelerate the translation of remedial concepts into clinical trials and improve the effectiveness of ovarian cancer treatment.

Statins and renal cell carcinoma: Antitumor activity and influence on cancer risk and survival

Statins are commonly prescribed to reduce plasma cholesterol levels and risk of cardiovascular events and mortality. Statin exposure may have cancer-preventive properties in some solid tumors, including Renal Cell Carcinoma (RCC). Emerging evidences show that statins can inhibit RCC cell growth by inducing cell cycle arrest and apoptosis in a dose- and time-dependent manner. In addition, statins inhibit the phosphorylation of AKT, mammalian target of rapamycin (mTOR), and ERK leading to reduced motility of RCC cells. Interestingly, the potential impact of concomitant statin intake has been recently evaluated in RCC patients treated by targeted therapy or immunotherapy. In this review, we illustrate the most recent data on the preclinical activity of statins in Renal Cell Carcinoma models and discuss the impact of their use on the prevention and survival of patients affected by this tumor.

Qing Zao Fang (QZF) Alleviates the Inflammatory Microenvironment of the Submandibular Gland in Sjögren's Syndrome Based on the PI3K/Akt/HIF-1α/VEGF Signaling Pathway

Sjögren's syndrome (SS) which could lead to a disorder of our immune system is a chronic autoimmune disease characterized by invading exocrine glands such as salivary glands and lacrimal glands and other exocrine glands. Its common symptom is dry mouth and dry eyes, often accompanied by a large number of lymphocyte infiltrations and can involve other organs to cause complex clinical manifestations. In this study, we aimed at investigating the effect of QZF in SS, identifying the molecular mechanism in modulating autoimmune response, and determining the important roles of these factors' function as a modulator in the pathogenesis of SS. The NOD mice were utilized to establish the rats' model of Sjögren's syndrome. After 10 weeks' hydroxychloroquine and QZF in different dose interference, submandibular gland tissue was collected. The therapeutic effect of QZF on SS rats was identified, and the results suggest the comparable potential to hydroxychloroquine. In submandibular gland tissue, interleukin- (IL-) 17 was significantly lower in high-dose QZF than that in SS rats and the focal lymphocytes were highly attenuated. Moreover, we found that PI3K/Akt signals were activated and the downstream HIF-1α/VEGF signals were enhanced in SS rats whose protein expression could be inhibited by QZF treatment. In addition, QZF could modulate autophagy in submandibular gland tissue and then inhibit the inflammation response and therefore facilitate the tissue repair.

Targeting the Tumor Microenvironment: A Literature Review of the Novel Anti-Tumor Mechanism of Statins

Statins is widely used in clinical practice as lipid-lowering drugs and has been proven to be effective in the treatment of cardiovascular, endocrine, metabolic syndrome and other diseases. The latest preclinical evidence shows that statins have anti-proliferation, pro-apoptotic, anti-invasion and radiotherapy sensitization effects on tumor cells, suggesting that statins may become a new type of anti-tumor drugs. For a long time, mevalonate pathway has been proved to play a supporting role in the development of tumor cells. As an effective inhibitor of mevalonate pathway, statins have been proved to have a direct auxiliary anti-tumor effect in a large number of studies. In addition, anti-tumor effects of statins through ferroptosis, pyroptosis, autophagy and tumor microenvironment (TME) have also been gradually discovered. However, the specific mechanism of the antitumor effect of statins in the tumor microenvironment has not been clearly elucidated. Herein, we reviewed the antitumor effects of statins in tumor microenvironment, focusing on hypoxia microenvironment, immune microenvironment, metabolic microenvironment, acid microenvironment and mechanical microenvironment.

Targeting tumor vascularization: promising strategies for vascular normalization

Tumor recurrence after the clinical cure of tumor often results from the presence of an abnormal microenvironment, including an aberrant vasculature. The tumor microenvironment is rich in pro-angiogenic factors but lacks pro-maturation factors. Pro-angiogenic conditions in the tumor microenvironment, such as hypoxia, are double-edged swords, promoting both the repair of normal tissues and the development of an abnormal blood vessel network. The coexistence of perfusion and hypoxic zones and uneven blood vessel distribution in tumor tissues profoundly influence tumor deterioration, recurrence, and metastasis. Traditional anti-angiogenic therapies have shown limited efficacy, and promote drug resistance, and even metastasis. In contrast, vascular normalization therapy induces a more physiological-like state, leading to better outcomes and fewer side effects. Vascular normalization entails modifying the tumor vascular system to improve tumor oxygenation and substance transport, thereby contributing to improving the efficacy of radiotherapy, chemotherapy, and immunotherapy. This review mainly focuses on the process of tumor vascularization; potential therapeutic targets, including cells, metabolism, signaling pathways, and angiogenesis-related genes; and possible strategies to normalize blood vessels through regulating tumor vessel generation, the development of tumor vessels, and blood vessel fusion and pruning.

Targeting AMPK by Statins: A Potential Therapeutic Approach

Statins are a group of lipid-lowering drugs that inhibit cholesterol biosynthesis and have anti-inflammatory, anti-tumor, and immunomodulatory properties. Several lines of evidence indicate that statins regulate multiple proteins associated with the regulation of differing cellular pathways. The 5'-adenosine monophosphate-activated protein kinase (AMPK) pathway plays an important role in metabolism homeostasis with effects on cellular processes including apoptosis and the inflammatory responses through several pathways. Recently, it has been shown that statins can affect the AMPK pathway in differing physiological and pathological ways, resulting in anti-cancer, cardio-protective, neuro-protective, and anti-tubercular effects; additionally, they have therapeutic effects on non-alcoholic fatty liver disease and diabetes mellitus-associated complications. Statins activate AMPK as an energy sensor that inhibits cell proliferation and induces apoptosis in cancer cells, whilst exerting its cardio-protective effects through inhibition of inflammation and fibrosis, and promotion of angiogenesis. Furthermore, statin-associated AMPK activation leads to decreased lipid accumulation and decreased amyloid beta deposition in the liver and brain, respectively, and may have therapeutic effects on the liver and neurons. In this review, we summarize the results of studies of AMPK-associated therapeutic effects of statins in different pathological conditions.

Atorvastatin pleiotropically decreases intraplaque angiogenesis and intraplaque haemorrhage by inhibiting ANGPT2 release and VE-Cadherin internalization

OBJECTIVE

Statins pleiotropically provide additional benefits in reducing atherosclerosis, but their effects on intraplaque angiogenesis (IPA) and hemorrhage (IPH) remain unclear. Therefore, we discriminated statin's lipid-lowering dependent and independent effects on IPA and IPH.

APPROACH AND RESULTS

ApoE3*Leiden mice are statin-responsive due to ApoE and LDLR presence, but also allow to titrate plasma cholesterol levels by diet. Therefore, ApoE3*Leiden mice were fed a high-cholesterol-inducing-diet (HCD) with or without atorvastatin (A) or a moderate-cholesterol-inducing-diet (MCD). Mice underwent vein graft surgery to induce lesions with IPA and IPH. Cholesterol levels were significantly reduced in MCD (56%) and HCD + A (39%) compared to HCD with no significant differences between MCD and HCD + A. Both MCD and HCD + A have a similar reduction in vessel remodeling and inflammation comparing to HCD. IPA was significantly decreased by 30% in HCD + A compared to HCD or MCD. Atorvastatin treatment reduced the presence of immature vessels by 34% vs. HCD and by 25% vs. MCD, resulting in a significant reduction of IPH. Atorvastatin's anti-angiogenic capacity was further illustrated by a dose-dependent reduction of ECs proliferation and migration. Cultured mouse aortic-segments lost sprouting capacity upon atorvastatin treatment and became 30% richer in VE-Cadherin expression and pericyte coverage. Moreover, Atorvastatin inhibited ANGPT2 release and decreased VE-Cadherin(Y685)-phosphorylation in ECs.

CONCLUSIONS

Atorvastatin has beneficial effects on vessel remodeling due to its lipid-lowering capacity. Atorvastatin has strong pleiotropic effects on IPA by decreasing the number of neovessels and on IPH by increasing vessel maturation. Atorvastatin improves vessel maturation by inhibiting ANGPT2 release and phospho(Y658)-mediated VE-Cadherin internalization.

Comparative transcriptomic analysis of vascular endothelial cells after hypoxia/re-oxygenation induction based on microarray technology

OBJECTIVE

To provide comprehensive data to understand mechanisms of vascular endothelial cell (VEC) response to hypoxia/re-oxygenation.

METHODS

Human umbilical vein endothelial cells (HUVECs) were employed to construct hypoxia/re-oxygenation-induced VEC transcriptome profiling. Cells incubated under 5% O₂, 5% CO₂, and 90% N₂ for 3 h followed by 95% air and 5% CO₂ for 1 h were used in the hypoxia/re-oxygenation group. Those incubated only under 95% air and 5% CO₂ were used in the normoxia control group.

RESULTS

By using a well-established microarray chip consisting of 58 339 probes, the study identified 372 differentially expressed genes. While part of the genes are known to be VEC hypoxia/re-oxygenation-related, serving as a good control, a large number of genes related to VEC hypoxia/re-oxygenation were identified for the first time. Through bioinformatic analysis of these genes, we identified that multiple pathways were involved in the reaction. Subsequently, we applied real-time polymerase chain reaction (PCR) and western blot techniques to validate the microarray data. It was found that the expression of apoptosis-related proteins, like pleckstrin homology-like domain family A member 1 (PHLDA1), was also consistently up-regulated in the hypoxia/re-oxygenation group. STRING analysis found that significantly differentially expressed genes SLC38A3, SLC5A5, Lnc-SLC36A4-1, and Lnc-PLEKHJ1-1 may have physical or/and functional protein-protein interactions with PHLDA1.

CONCLUSIONS

The data from this study have built a foundation to develop many hypotheses to further explore the hypoxia/re-oxygenation mechanisms, an area with great clinical significance for multiple diseases.

Association Between Statin Use and Prognosis of Breast Cancer: A Meta-Analysis of Cohort Studies

Background: Statin, a lipid-lowering drug, has been suggested to confer anticancer efficacy. However, previous studies evaluating the association between statin use and prognosis in breast cancer showed inconsistent results. A meta-analysis was performed to evaluate the association between statin use and clinical outcome in women with breast cancer.

Methods: Cohort studies comparing recurrence or disease-specific mortality in women with breast cancer with and without using of statins were identified by search of PubMed, Embase, and Cochrane's Library databases. A random-effect model, incorporating the inter-study heterogeneity, was used to combine the results. Subgroup analyses were performed to evaluate the influences of study characteristics on the outcomes

Results: Seventeen cohort studies with 168,700 women with breast cancer were included. Pooled results showed that statin use was significantly associated with a lower risk of breast cancer recurrence (adjusted hazard ratio [HR] = 0.72, p < 0.001) and breast cancer mortality (HR = 0.80, p < 0.001). Subgroup analysis showed that timing of statin use, statin type, study design, sample size, or quality score did not significantly affect the outcomes. However, statin use was associated with more remarkably reduced breast cancer recurrence in studies with mean follow-up duration ≤ 5 years (HR = 0.55, p < 0.001) than that in studies of >5 years (HR = 0.83, p = 0.01).

Conclusions: Statin use is associated with reduced recurrence and disease-specific mortality in women with breast cancer. These results should be validated in randomized controlled trials.

Atorvastatin disrupts primary human brain microvascular endothelial cell functions via prenylation-dependent mitochondrial inhibition and oxidative stress

Primary human brain microvascular endothelial cell (HBMEC) is the major component of the blood-brain barrier (BBB). Atorvastatin, a HMG-CoA reductase inhibitor, is a cholesterol-lowering drug commonly used to reduce the risk for cardiovascular disease. Numerous studies have reported the pleiotropic effects of atorvastatin on endothelial cells, but the findings are controversial and inconclusive. In addition, little is known about the biological effects of atorvastatin on HBMEC. In this work, we demonstrate that atorvastatin at micromolar but not nanomolar concentrations induces dysfunctions of a number of HBMEC events, including differentiation into capillary network, migration and growth but not cell adhesion. We further show that the inhibitory effects of atorvastatin on HBMEC are independent of angiogenesis stimulators. Atorvastatin induces HBMEC apoptosis even in the presence of vascular endothelial growth factor (VEGF) and serum. Mechanism studies indicate that atorvastatin at micromolar concentration leads to protein prenylation inhibition, mitochondrial dysfunction and thereby subsequent oxidative stress and damage in HBMEC. Rescue experiments confirm that atorvastatin inhibits HBMEC functions via prenylation-dependent mitochondrial inhibition. Our work reveals the inhibitory effects of atorvastatin on HBMEC and suggests the possible negative influence of atorvastatin in blood-brain barrier.

Regulation of cancer cell glucose metabolism is determinant for cancer cell fate after melatonin administration

Several oncogenic pathways plus local microenvironmental conditions, such as hypoxia, converge on the regulation of cancer cells metabolism. The major metabolic alteration consists of a shift from oxidative phosphorylation as the major glucose consumer to aerobic glycolysis, although most of cancer cells utilize both pathways to a greater or lesser extent. Aerobic glycolysis, together with the directly related metabolic pathways such as the tricarboxylic acid cycle, the pentose phosphate pathway, or gluconeogenesis are currently considered as therapeutic targets in cancer research. Melatonin has been reported to present numerous antitumor effects, which result in a reduced cell growth. This is achieved with both low and high concentrations with no relevant side effects. Indeed, high concentrations of this indolamine reduce proliferation of cancer types resistant to low concentrations and induce cell death in some types of tumors. Previous work suggest that regulation of glucose metabolism and other related pathways play an important role in the antitumoral effects of high concentration of melatonin. In the present review, we analyze recent work on the regulation by such concentrations of this indolamine on aerobic glycolysis, gluconeogenesis, the tricarboxylic acid cycle and the pentose phosphate pathways of cancer cells.

The Roles of AMPK in Revascularization

Coronary heart disease (CHD) is the most common and serious illness in the world and has been researched for many years. However, there are still no real effective ways to prevent and save patients with this disease. When patients present with myocardial infarction, the most important step is to recover ischemic prefusion, which usually is accomplished by coronary artery bypass surgery, coronary artery intervention (PCI), or coronary artery bypass grafting (CABG). These are invasive procedures, and patients with extensive lesions cannot tolerate surgery. It is, therefore, extremely urgent to search for a noninvasive way to save ischemic myocardium. After suffering from ischemia, cardiac or skeletal muscle can partly recover blood flow through angiogenesis (de novo capillary) induced by hypoxia, arteriogenesis, or collateral growth (opening and remodeling of arterioles) triggered by dramatical increase of fluid shear stress (FSS). Evidence has shown that both of them are regulated by various crossed pathways, such as hypoxia-related pathways, cellular metabolism remodeling, inflammatory cells invasion and infiltration, or hemodynamical changes within the vascular wall, but still they do not find effective target for regulating revascularization at present. 5′-Adenosine monophosphate-activated protein kinase (AMPK), as a kinase, is not only an energy modulator but also a sensor of cellular oxygen-reduction substances, and many researches have suggested that AMPK plays an essential role in revascularization but the mechanism is not completely understood. Usually, AMPK can be activated by ADP or AMP, upstream kinases or other cytokines, and pharmacological agents, and then it phosphorylates key molecules that are involved in energy metabolism, autophagy, anti-inflammation, oxidative stress, and aging process to keep cellular homeostasis and finally keeps cell normal activity and function. This review makes a summary on the subunits, activation and downstream targets of AMPK, the mechanism of revascularization, the effects of AMPK in endothelial cells, angiogenesis, and arteriogenesis along with some prospects.

Simvastatin alleviated diabetes mellitus-induced erectile dysfunction in rats by enhancing AMPK pathway-induced autophagy

BACKGROUND

Diabetes mellitus-induced erectile dysfunction is a common diabetic complication, and new therapeutics and the pathogenesis of diabetes mellitus-induced erectile dysfunction need to be investigated.

OBJECTIVES

The aim was to investigate the pathogenesis of diabetes mellitus-induced erectile dysfunction and the pharmacological mechanism of simvastatin treatment in diabetes mellitus-induced erectile dysfunction model rats.

MATERIALS AND METHODS

A total of 86 male Sprague Dawley rats aged 8 weeks old were used in this study. The rats were divided into three groups: control (normal), diabetes mellitus-induced erectile dysfunction (streptozotocin-injected), and diabetes mellitus-induced erectile dysfunction + simvastatin (sim). Each group was subdivided into two subgroups for in vitro and in vivo analyses. A bioinformatics method was used to detect differences in gene expression in the corpus cavernosum between normal and diabetes mellitus-induced erectile dysfunction rats. Erectile function was measured by a cavernous nerve electrostimulation test. Corpus cavernosum fibrosis was assessed by Masson staining and Western blotting. Immunofluorescence and Western blotting were performed to explore the differential expression of autophagy-related genes and the AMPK-SKP2-CARM1 pathway genes in rat cavernous smooth muscle cells and the corpus cavernosum. The autophagosomes of the corpus cavernosum tissue were observed by transmission electron microscopy.

RESULTS

Autophagy-related genes and pathways (the AMPK and FoxO pathway) were identified by bioinformatics analysis and confirmed at the protein level. Simvastatin, an AMPK agonist, was used to treat diabetes mellitus-induced erectile dysfunction rats for 8 weeks, demonstrating that erectile function was improved for 80.5% (P < .05) of rats. Corpus cavernosum fibrosis was alleviated (P < .05), and autophagy was further enhanced (P < .05); these results might be partially caused by AMPK-SKP2-CARM1 pathway activation (P < .05).

DISCUSSION AND CONCLUSION

Simvastatin could enhance protective autophagy by activating the AMPK-SKP2-CARM1 pathway to improve erectile function in diabetes mellitus-induced erectile dysfunction rats.

Atorvastatin promotes AMPK signaling to protect against high fat diet-induced non-alcoholic fatty liver in golden hamsters

Non-alcoholic fatty liver disease (NAFLD) is characterized by diffuse fatty acid degeneration and excess fat accumulation in the liver. Notably, the currently available medications used to treat NAFLD remain limited. The aim of the present study was to investigate the protective role of atorvastatin (Ato) against NAFLD in golden hamsters fed a high fat diet (HFD) and in HepG2 cells treated with palmitate, and identify the underlying molecular mechanism. Ato (3 mg/kg) was administered orally every day for 8 weeks to the hamsters during HFD administration. Hamsters in the model group developed hepatic steatosis with high serum levels of triglyceride, cholesterol, insulin and C-reactive protein, which were effectively reduced by treatment with Ato. Additionally, the relative liver weight of hamsters treated with Ato was markedly lower compared with that of the model group. Hematoxylin and eosin, and oil red O staining indicated that the livers of the animals in the model group exhibited large and numerous lipid droplets, which were markedly decreased after Ato treatment. Western blot analysis indicated that Ato inhibited fat accumulation in the liver through the AMP-activated protein kinase (AMPK)-dependent activation of peroxisome proliferator activated receptor α (PPARα), peroxisome proliferator-activated receptor-γ coactivator 1 α and their target genes. Furthermore, in vitro, Ato inhibited PA-induced lipid accumulation in HepG2 cells. This inhibitory effect was attenuated following Compound C treatment, indicating that AMPK may be a potential target of Ato. In conclusion, the increase in AMPK-mediated PPARα and its target genes may represent a novel molecular mechanism by which Ato prevents NAFLD.

Antitumor and anti-angiogenic effects of artemisinin on breast tumor xenografts in nude mice

Breast cancer is a high incidence disease in humans. Artemisinin is an important extract that is widely used as an antimalarial drug which also serve as effective treatments for cancer. 32 nude mice were injected with 0.2 ml of MDA-MB-231 cell suspension of 2 × 10⁷ cells/ml respectively. The nude mice models were randomly divided into four groups of 8 in each group. Each group was given daily gavage, high dose group: 200 mg/kg/0.1 ml, middle dose group 100 mg/kg/0.1 ml, low dose group 50 mg/kg/0.1 ml, control group: 0.1 ml vegetable oil was fed continuously for 21 days. ELISA was used to detect serum vascular endothelial growth the content of factor VEGF and hypoxia-inducible factor HIF-1α were detected. The expression of Notch pathway-related factors in tumor tissue was detected by fluorescence quantitative assay. ELISA results showed that the serum VEGF decreased significantly in the high dose group compared with the control group (p < .01), while the other dose groups did not have significant (p > .05). The serum HIF-1α in the high dose group compared with the control group, the decrease in HIF-1α was significant (p < .05), and the other groups were not significant (p > .05). The result of fluorescence quantitative section showed that artemisinin could down-regulate the expression of notch signaling related factors notch1, Dll4 and Jagged1, and 200 mg/kg dose group had the most significant effect. It may inhibit the development of tumors by reducing serum angiogenesis-related factors VEGF, HIF-1ɑ and inhibiting the activity of notch1 signaling pathway related factors.

Statins Directly Regulate Pituitary Cell Function and Exert Antitumor Effects in Pituitary Tumors

INTRODUCTION

Pituitary neuroendocrine tumors (PitNETs), the most abundant of all intracranial tumors, entail severe comorbidities. First-line therapy is transsphenoidal surgery, but subsequent pharmacological therapy is often required. Unfortunately, many patients are/become unresponsive to available drugs (somatostatin analogues [SSAs]/dopamine agonists), underscoring the need for new therapies. Statins are well-known drugs commonly prescribed to treat hyperlipidemia/cardiovascular diseases, but can convey additional beneficial effects, including antitumor actions. The direct effects of statins on normal human pituitary or PitNETs are poorly known. Thus, we aimed to explore the direct effects of statins, especially simvastatin, on key functional parameters in normal and tumoral pituitary cells, and to evaluate the combined effects of simvastatin with metformin (MF) or SSAs.

METHODS

Effects of statins in cell proliferation/viability, hormone secretion, and signaling pathways were evaluated in normal pituitary cells from a primate model (Papio anubis), tumor cells from corticotropinomas, somatotropinomas, nonfunctioning pituitary tumors, and PitNET cell-lines (AtT20/GH3-cells).

RESULTS

All statins decreased AtT20-cell proliferation, simvastatin showing stronger effects. Indeed, simvastatin reduced cell viability and/or hormone secretion in all PitNETs subtypes and cell-lines, and ACTH/GH/PRL/FSH/LH secretion (but not expression), in primate cell cultures, by modulating MAPK/PI3K/mTOR pathways and expression of key receptors (GH-releasing hormone-receptor/ghrelin-R/Kiss1-R) regulating pituitary function. Addition of MF or SSAs did not enhance simvastatin antitumor effects.

CONCLUSION

Our data reveal direct antitumor effects of simvastatin on PitNET-cells, paving the way to explore these compounds as a possible tool to treat PitNETs.

Statin-Induced Nitric Oxide Signaling: Mechanisms and Therapeutic Implications

In addition to their cholesterol-lowering effects, statins are associated with pleiotropic effects including improvements in heart failure (HF), reduced blood pressure, prevention of the rupture of atherosclerotic plaques and improved angiogenesis. In addition to these cardiovascular benefits, statins have been implicated in the treatment of neurological injuries, cancer, sepsis, and cirrhosis. These cholesterol-independent beneficial effects of statins are predominantly mediated through signaling pathways leading to increased production and bioavailability of nitric oxide (NO). In this review, the mechanistic pathways and therapeutic effects of statin-mediated elevations of NO are described and discussed.

PlGF signaling and macrophage repolarization contribute to the anti-neoplastic effect of metformin

Placental growth factor (PlGF) related signaling pathway has been shown to have close relationship with the progression of cancers. Metformin has been reported to have an inhibitory effect on PlGF expression in a breast cancer model. However, little is known about whether the anti-neoplastic activity of metformin is contributed by its inhibitory effect on PlGF expression. Protein, mRNA and secretion levels of PlGF were tested and the proliferation of cancer cells was determined. After treatment of metformin, BALB/c mice bearing 4T1 tumors were sacrificed and immunohistochemistry staining of the tumor sections was obtained. Baseline expression of autocrine PlGF varied between different breast cancer cell lines, while the expression of vascular endothelial growth factor receptor-1 (VEGFR-1) was comparable between cell lines. Other clinical data showed that the expression of PlGF other than VEGFR-1 had a prognostic value for patients with breast cancers. Metformin significantly decreased the secretion and mRNA levels of PlGF, which greatly contributed to its inhibitory effect on the proliferation of breast cancer cells with high P1GF expression. The unresponsiveness of tumor cells with low PlGF expression to genetic silencing was reversed by the supplementation of exogenous PlGF. Systemic metformin administration apparently inhibited the in vivo growth of 4T1 carcinoma, which was accompanied by the repolarization of macrophages from M2 to M1. These findings indicated that both autocrine and paracrine PlGF signaling and macrophage repolarization are involved in the progression of breast cancer, which could be targeted by metformin.

Dual Roles of the AMP-Activated Protein Kinase Pathway in Angiogenesis

Angiogenesis plays important roles in development, stress response, wound healing, tumorigenesis and cancer progression, diabetic retinopathy, and age-related macular degeneration. It is a complex event engaging many signaling pathways including vascular endothelial growth factor (VEGF), Notch, transforming growth factor-beta/bone morphogenetic proteins (TGF-β/BMPs), and other cytokines and growth factors. Almost all of them eventually funnel to two crucial molecules, VEGF and hypoxia-inducing factor-1 alpha (HIF-1α) whose expressions could change under both physiological and pathological conditions. Hypoxic conditions stabilize HIF-1α, while it is upregulated by many oncogenic factors under normaxia. HIF-1α is a critical transcription activator for VEGF. Recent studies have shown that intracellular metabolic state participates in regulation of sprouting angiogenesis, which may involve AMP-activated protein kinase (AMPK). Indeed, AMPK has been shown to exert both positive and negative effects on angiogenesis. On the one hand, activation of AMPK mediates stress responses to facilitate autophagy which stabilizes HIF-1α, leading to increased expression of VEGF. On the other hand, AMPK could attenuate angiogenesis induced by tumor-promoting and pro-metastatic factors, such as the phosphoinositide 3-kinase /protein kinase B (Akt)/mammalian target of rapamycin (PI3K/Akt/mTOR), hepatic growth factor (HGF), and TGF-β/BMP signaling pathways. Thus, this review will summarize research progresses on these two opposite effects and discuss the mechanisms behind the discrepant findings.

Simvastatin, at clinically relevant concentrations, affects human uterine leiomyoma growth and extracellular matrix production

OBJECTIVE

To observe the antifibroid effects of therapeutic concentrations of simvastatin, which interferes with cholesterol biosynthesis, a known precursor of five major classes of steroid hormones, including progesterone and estrogen, which play a major role in the development and growth of uterine leiomyomas.

DESIGN

Two-dimensional and three-dimensional cell culture study of immortalized human leiomyoma and patient-matched myometrium cells treated with simvastatin.

SETTING

University laboratory.

PATIENT(S)

None.

INTERVENTIONS(S)

None.

MAIN OUTCOME MEASURE(S)

Cell proliferation, alteration in apoptotic signaling pathways, and extracellular matrix (ECM) protein production.

RESULT(S)

Simvastatin demonstrated a concentration-dependent antiproliferative effect on both the leiomyoma cells and the patient-matched myometrium cells, but a higher inhibitory effect at lower concentrations of simvastatin was observed in leiomyoma cells. Simvastatin also regulated leiomyoma cell apoptosis through a concentration-dependent increase in activity of caspase-3. Simvastatin significantly inhibited expression of major ECM proteins collagen I, collagen III, fibronectin, versican, and brevican in leiomyoma cells at concentrations as low as 10^-9 mol/L within 48 hours of exposure.

CONCLUSION(S)

Simvastatin induces apoptosis in uterine leiomyoma cells at low concentrations, as evidenced by increased active caspase levels. Furthermore, inhibited production of the ECM proteins may lead to reduction in tumor size. Simvastatin may represent a novel therapeutic treatment strategy for uterine leiomyomas.

Ezrin promotes breast cancer progression by modulating AKT signals

Background

Ezrin, which is known as a cytoskeleton linker protein, is closely linked with the metastatic progression of cancer and is frequently abnormally expressed in aggressive cancer types. However, the possible involvement of Ezrin in metastasis and angiogenesis in breast cancer remains unclear.

Methods

Immunohistochemical analysis of Ezrin was performed on both BC samples (n = 117) and normal epithelium samples (n = 47). In vivo and in vitro assays were performed to validate the effect of Ezrin on AKT pathway-mediated BC progression.

Results

In this study, Ezrin was found to be upregulated in BC tissues, which was linked with aggressive tumour characteristics and poor prognosis. Moreover, we showed that Ezrin promotes BC proliferation, migration, invasion, and angiogenesis in vitro and in vivo. Mechanistic analysis showed that Ezrin interacted with AKT, and promoted its kinase activity, thereby regulating the AKT pathway in BC.

Conclusions

In all, we propose a model for an Ezrin/AKT oncoprotein axis, which provides novel insight into how Ezrin contributes to BC progression.

The inhibitive effect of sh-HIF1A-AS2 on the proliferation, invasion, and pathological damage of breast cancer via targeting miR-548c-3p through regulating HIF-1α/VEGF pathway in vitro and vivo

Background

Breast cancer (BC) has been the commonest malignant tumor with a low survival rate among woman. Long non-coding RNA hypoxia-inducible factor-1 alpha antisense RNA-2 (HIF1A-AS2) was correlated with various cancers.

Purpose

The study aimed to investigate the roles and related underlying molecular mechanisms of HIF1A-AS2 in BC.

Material and methods

Target relationships were speculated by Targetscan 7.0 and confirmed by dual luciferase reporter assay. Proteins levels were monitored by RT-qPCR, Western blot and immunohistochemistry assays. CCK-8 assay, SA-β-gal staining and transwell assay were used to detect proliferation, senescence and invasion, respectively. Xenograft nude mice were put into use to evaluate the tumor growth and motility.

Results

The present study exhibited that HIF1A-AS2 and hypoxia-inducible factor-1 alpha (HIF-1α) were upregulated while miR-548c-3p was downregulated in MDA-MB-231, MCF-7, ZR-75-1, and BT-549 BC cell lines. Bioinformatics analysis showed HIF1A-AS2 and HIF-1α were two targets of miR-548c-3p, and the target relationship was further confirmed by dual luciferase reporter assay. Moreover, knockdown of HIF1A-AS2 by shRNA (sh-HIF1A-AS2) markedly elevated miR-548c-3p level, and the enhanced miR-548c-3p noticeably suppressed cell proliferation, invasion, and epithelial–mesenchymal transition, and promoted senescence in vitro. In addition, overexpression of HIF-1α promoted MCF-7 cell invasion. Intriguingly, low expression of HIF1A-AS2 reduced HIF-1α level by upregulating the expression of miR-548c-3p. Furthermore, experiment in xenograft nude mice has indicated that sh-HIF1A-AS2 inhibited tumor growth and motility by targeting miR-548c-3p through regulating HIF-1α/vascular endothelial growth factor (VEGF) pathway in vivo.

Conclusion

The inhibitive effect of HIF-1α/VEGF pathway by sh-HIF1A-AS2 through targeting miR-548c-3p plays crucial regulatory roles in BC. Therefore, designing targeted drugs against HIF1A-AS2 provides a new direction for the treatment of BC.

Anti-Angiogenic Alternative and Complementary Medicines for the Treatment of Endometriosis: A Review of Potential Molecular Mechanisms

Endometriosis is caused by the growth or infiltration of endometrial tissues outside of the endometrium and myometrium. Symptoms include pain and infertility. Surgery and hormonal therapy are widely used in Western medicine for the treatment of endometriosis; however, the side effects associated with this practice include disease recurrence and menopause, which can severely influence quality of life. Angiogenesis is the main biological mechanism underlying the development of endometriosis. Numerous natural products and Chinese medicines with potent anti-angiogenic effects have been investigated, and the molecular basis underlying their therapeutic effects in endometriosis has been explored. This review aims to describe natural products and compounds that suppress angiogenesis associated with endometriosis and to assess their diverse molecular mechanisms of action. Furthermore, this review provides a source of information relating to alternative and complementary therapeutic products that mediate anti-angiogenesis. An extensive review of the literature and electronic databases, such as the China National Knowledge Infrastructure, PubMed, and Embase, was conducted using the keywords 'endometriosis,' 'traditional Chinese medicine,' 'Chinese herbal medicine,' 'natural compounds,' and 'anti-angiogenic' therapy. Anti-angiogenic therapy is an emerging strategy for the treatment of endometriosis. Natural anti-angiogenic products and Chinese medicines provide several beneficial clinical effects, including pain relief. In this review, we summarize clinical trials and experimental studies of endometriosis using natural products and Chinese medicines. In particular, we focus on anti-angiogenic products and alternative and complementary medicines for the treatment of endometriosis and additionally examine their therapeutic efficacy and mechanisms of action. Anti-angiogenic natural products and/or compounds provide a new approach for the treatment of endometriosis. Future work will require randomized trials with larger numbers of subjects, as well as long-term follow-up to confirm the findings described here.

Atorvastatin, but not pravastatin, inhibits cardiac Akt/mTOR signaling and disturbs mitochondrial ultrastructure in cardiac myocytes

Statins, which reduce LDL-cholesterol by inhibition of 3-hydroxy-3-methylglutaryl-coenzyme A reductase, are among the most widely prescribed drugs. Skeletal myopathy is a known statin-induced adverse effect associated with mitochondrial changes. We hypothesized that similar effects would occur in cardiac myocytes in a lipophilicity-dependent manner between 2 common statins: atorvastatin (lipophilic) and pravastatin (hydrophilic). Neonatal cardiac ventricular myocytes were treated with atorvastatin and pravastatin for 48 h. Both statins induced endoplasmic reticular (ER) stress, but only atorvastatin inhibited ERK1/2^T202/Y204, Akt^Ser473, and mammalian target of rapamycin signaling; reduced protein abundance of caveolin-1, dystrophin, epidermal growth factor receptor, and insulin receptor-β; decreased Ras homolog gene family member A activation; and induced apoptosis. In cardiomyocyte-equivalent HL-1 cells, atorvastatin, but not pravastatin, reduced mitochondrial oxygen consumption. When male mice underwent atorvastatin and pravastatin administration per os for up to 7 mo, only long-term atorvastatin, but not pravastatin, induced elevated serum creatine kinase; swollen, misaligned, size-variable, and disconnected cardiac mitochondria; alteration of ER structure; repression of mitochondria- and endoplasmic reticulum-related genes; and a 21% increase in mortality in cardiac-specific vinculin-knockout mice during the first 2 months of administration. To our knowledge, we are the first to demonstrate in vivo that long-term atorvastatin administration alters cardiac ultrastructure, a finding with important clinical implications.-Godoy, J. C., Niesman, I. R., Busija, A. R., Kassan, A., Schilling, J. M., Schwarz, A., Alvarez, E. A., Dalton, N. D., Drummond, J. C., Roth, D. M., Kararigas, G., Patel, H. H., Zemljic-Harpf, A. E. Atorvastatin, but not pravastatin, inhibits cardiac Akt/mTOR signaling and disturbs mitochondrial ultrastructure in cardiac myocytes.

Activation of AMPK by simvastatin inhibited breast tumor angiogenesis via impeding HIF-1α-induced pro-angiogenic factor

Substantial data from preclinical studies have revealed the biphasic effects of statins on cardiovascular angiogenesis. Although some have reported the anti‐angiogenic potential of statins in malignant tumors, the underlying mechanism remains poorly understood. The aim of this study is to elucidate the mechanism by which simvastatin, a member of the statin family, inhibits tumor angiogenesis. Simvastatin significantly suppressed tumor cell‐conditioned medium‐induced angiogenic promotion in vitro, and resulted in dose‐dependent anti‐angiogenesis in vivo. Further genetic silencing of hypoxia‐inducible factor‐1α (HIF‐1α) reduced vascular endothelial growth factor and fibroblast growth factor‐2 expressions in 4T1 cells and correspondingly ameliorated HUVEC proliferation facilitated by tumor cell‐conditioned medium. Additionally, simvastatin induced angiogenic inhibition through a mechanism of post‐transcriptional downregulation of HIF‐1α by increasing the phosphorylation level of AMP kinase. These results were further validated by the fact that 5‐aminoimidazole‐4‐carboxamide ribonucleotide reduced HIF‐1α protein levels and ameliorated the angiogenic ability of endothelial cells in vitro and in vivo. Critically, inhibition of AMPK phosphorylation by compound C almost completely abrogated simvastatin‐induced anti‐angiogenesis, which was accompanied by the reduction of protein levels of HIF‐1α and its downstream pro‐angiogenic factors. These findings reveal the mechanism by which simvastatin induces tumor anti‐angiogenesis, and therefore identifies the target that explains the beneficial effects of statins on malignant tumors.