Aspirin inhibits mTOR signaling, activates AMP-activated protein kinase, and induces autophagy in colorectal cancer cells

Resistance to FGFR1-targeted therapy leads to autophagy via TAK1/AMPK activation in gastric cancer

BACKGROUND

Fibroblast growth factor receptor 1 (FGFR1) is frequently dysregulated in various tumors. FGFR inhibitors have shown promising therapeutic value in several preclinical models. However, tumors resistant to FGFR inhibitors have emerged, compromising therapeutic outcomes by demonstrating markedly aggressive metastatic progression; however, the underlying signaling mechanism of resistance remains unknown.

METHODS

We established FGFR inhibitor-resistant cell models using two gastric cancer (GC) cell lines, MGC-803 and BGC-823. RNA-seq was performed to determine the continuous cellular transcriptome changes between parental and resistant cells. We explored the mechanism of resistance to FGFR inhibitor, using a subcutaneous tumor model and GC patient-derived tumor organotypic culture.

RESULTS

We observed that FGFR1 was highly expressed in GC and FGFR1 inhibitor-resistant cell lines, demonstrating elevated levels of autophagic activity. These resistant cells were characterized by epithelial-mesenchymal transition (EMT) required to facilitate metastatic outgrowth. In drug-resistant cells, the FGFR1 inhibitor regulated GC cell autophagy via AMPK/mTOR signal activation, which could be blocked using either pharmacological inhibitors or essential gene knockdown. Furthermore, TGF-β-activated kinase 1 (TAK1) amplification and metabolic restrictions led to AMPK pathway activation and autophagy. In vitro and in vivo results demonstrated that the FGFR inhibitor AZD4547 and TAK1 inhibitor NG25 synergistically inhibited proliferation and autophagy in AZD4547-resistant cell lines and patient-derived GC organotypic cultures.

CONCLUSIONS

We elucidated the molecular mechanisms underlying primary resistance to FGFR1 inhibitors in GC, and revealed that the inhibition of FGFR1 and TAK1 signaling could present a potential novel therapeutic strategy for FGFR1 inhibitor-resistant GC patients.

St. John's Wort Suppresses Growth in Triple-Negative Breast Cancer Cell Line MDA-MB-231 by Inducing Prodeath Autophagy and Apoptosis

The rational regulation of programmed cell death by means of autophagy and apoptosis has been considered a potential treatment strategy for cancer. We demonstrated the inhibitory effect of St. John’s Wort (SJW) on growth in the triple-negative breast cancer (TNBC) cell line and xenografted mice and its target mechanism concerning autophagic and apoptotic cell death. SJW ethanol extract (SJWE) inhibited proliferation in a dose-dependent manner. SJWE treatment dramatically increased autophagy flux and apoptosis compared with the control. The autophagy inhibitor, 3-methyladenine (3-MA), reversed the SJWE-induced inhibition of cell proliferation and regulation of autophagy and apoptosis, indicating that SJWE induced apoptosis through prodeath autophagy. Furthermore, SJWE inhibited tumor growth and induced autophagy and apoptosis in the tumor of MDA-MB-231 xenografted athymic nude mice. Our results indicate that SJWE might have great potential as a new anticancer therapy for triple-negative breast cancer by inducing prodeath autophagy and apoptosis.

Diclofenac impairs autophagic flux via oxidative stress and lysosomal dysfunction: Implications for hepatotoxicity

Treatment with nonsteroidal anti-inflammatory drugs (NSAIDs) is associated with various side effects, including cardiovascular and hepatic disorders. Studies suggest that mitochondrial damage and oxidative stress are important mediators of toxicity, yet the underlying mechanisms are poorly understood. In this study, we identified that some NSAIDs, including diclofenac, inhibit autophagic flux in hepatocytes. Further detailed studies demonstrated that diclofenac induced a reactive oxygen species (ROS)-dependent increase in lysosomal pH, attenuated cathepsin activity and blocked autophagosome-lysosome fusion. The reactivation of lysosomal function by treatment with clioquinol or transfection with the transcription factor EB restored lysosomal pH and thus autophagic flux. The production of mitochondrial ROS is critical for this process since scavenging ROS reversed lysosomal dysfunction and activated autophagic flux. The compromised lysosomal activity induced by diclofenac also inhibited the fusion with and degradation of mitochondria by mitophagy. Diclofenac-induced cell death and hepatotoxicity were effectively protected by rapamycin. Thus, we demonstrated that diclofenac induces the intracellular ROS production and lysosomal dysfunction that lead to the suppression of autophagy. Impaired autophagy fails to maintain mitochondrial integrity and aggravates the cellular ROS burden, which leads to diclofenac-induced hepatotoxicity.

Aspirin Rescues Wnt-Driven Stem-like Phenotype in Human Intestinal Organoids and Increases the Wnt Antagonist Dickkopf-1

BACKGROUND & AIMS

Aspirin reduces colorectal cancer (CRC) incidence and mortality. Understanding the biology responsible for this protective effect is key to developing biomarker-led approaches for rational clinical use. Wnt signaling drives CRC development from initiation to progression through regulation of epithelial-mesenchymal transition (EMT) and cancer stem cell populations. Here, we investigated whether aspirin can rescue these proinvasive phenotypes associated with CRC progression in Wnt-driven human and mouse intestinal organoids.

METHODS

We evaluated aspirin-mediated effects on phenotype and stem cell markers in intestinal organoids derived from mouse (ApcMin/+ and Apcflox/flox) and human familial adenomatous polyposis patients. CRC cell lines (HCT116 and Colo205) were used to study effects on motility, invasion, Wnt signaling, and EMT.

RESULTS

Aspirin rescues the Wnt-driven cystic organoid phenotype by promoting budding in mouse and human Apc deficient organoids, which is paralleled by decreased stem cell marker expression. Aspirin-mediated Wnt inhibition in ApcMin/+ mice is associated with EMT inhibition and decreased cell migration, invasion, and motility in CRC cell lines. Chemical Wnt activation induces EMT and stem-like alterations in CRC cells, which are rescued by aspirin. Aspirin increases expression of the Wnt antagonist Dickkopf-1 in CRC cells and organoids derived from familial adenomatous polyposis patients, which contributes to EMT and cancer stem cell inhibition.

CONCLUSIONS

We provide evidence of phenotypic biomarkers of response to aspirin with an increased epithelial and reduced stem-like state mediated by an increase in Dickkopf-1. This highlights a novel mechanism of aspirin-mediated Wnt inhibition and potential phenotypic and molecular biomarkers for trials.

Zinc oxide nanoparticles effectively regulate autophagic cell death by activating autophagosome formation and interfering with their maturation

BACKGROUND

With the development of zinc oxide nanoparticles (ZnO NPs) in the field of nanotechnology, their toxicological effects are attracting increasing attention, and the mechanisms for ZnO NPs neurotoxicity remain obscure. In an attempt to address concerns regarding neurotoxicity of ZnO NPs, we explored the relationship between free zinc ions, reactive oxygen species (ROS) and neurotoxic mechanisms in ZnO NPs-exposed PC12 cells.

RESULT

This study demonstrated the requirement of free zinc ions shed by ZnO NPs to over generation of intracellular ROS. Next, we identified autophagic cell death was the major mode of cell death induced by ZnO NPs, and autophagosome accumulation resulted from not only induction of autophagy, but also blockade of autophagy flux. We concluded that autophagic cell death, resulting from zinc ions-ROS-c-Jun N-terminal kinase (JNK)-autophagy positive feedback loop and blockade of autophagosomal-lysosomal fusion, played a major role in the neurotoxicity of ZnO NPs.

CONCLUSION

Our study contributes to a better understanding of the neurotoxicity of ZnO NPs and might be useful for designing and developing new biosafety nanoparticles in the future.

Energy Provisioning and Inflammasome Activation: The Pivotal Role of AMPK in Sterile Inflammation and Associated Metabolic Disorders

BACKGROUND

Body defenses and metabolic processes probably co-evolved in such a way that rapid, energy-intensive acute inflammatory repair is functionally integrated with energy allocation in a starvation/ infection / injury-prone primitive environment. Disruptive metabolic surplus, aggravated by sedentary lifestyle induces chronic under-activation of AMPK, the master regulator of intracellular energy homeostasis. Sudden increase in chronic, dysregulated 'sterile' inflammatory disorders probably results from a shift towards calorie rich, sanitized, cushioned, injury/ infection free environment, repositioning inflammatory repair pathways towards chronic, non-microbial, 'sterile', 'low grade', and 'parainflammation'. AMPK, (at the helm of energy provisioning) supervises the metabolic regulation of inflammasome activation, a common denominator in lifestyle disorders.

DISCUSSION

In this review, we discuss various pathways linking AMPK under-activation and inflammasome activation. AMPK under-activation, the possible norm in energy-rich sedentary lifestyle, could be the central agency that stimulates inflammasome activation by multiple pathways such as 1: decreasing autophagy, and accumulation of intracellular DAMPs, (particulate crystalline molecules, advanced glycation end-products, oxidized lipids, etc.) 2: stimulating a glycolytic shift (pro-inflammatory) in metabolism, 3: promoting NF-kB activation and decreasing Nrf2 activation, 4: increasing reactive oxygen species (ROS) formation, Unfolded Protein Response (UPR) and Endoplasmic Reticulum (ER) stress.

CONCLUSION

The 'inverse energy crisis' associated with calorie-rich, sedentary lifestyle, advocates dietary and pharmacological interventions for treating chronic metabolic disorders by overcoming / reversing AMPK under-activation.

The Function and Mechanisms of Autophagy in Trauma of Other Parts of the Body

Trauma is common in modern society. Besides TBI and SCI, trauma can lead to severe cardiopulmonary injury and even to death. Fracture and skin injury are also very likely to occur in our daily life. Limited studies have reported the levels of autophagy after heart and trauma, fracture, and skin injury. In this chapter, we update the current state of knowledge and recent advances in the study of autophagy after trauma including heart and lung trauma, fracture, and skin injury which we try to clarify how autophagy levels are affected by injury or trauma and how their manipulation may represent potential novel protective targets for treatments.

Aspirin protects human coronary artery endothelial cells by inducing autophagy

Although the use of aspirin has substantially reduced the risks of cardiovascular events and death, its potential mechanisms have not been fully elucidated. In a previous study, we found that aspirin triggers cellular autophagy. In the present study, we aimed to determine the protective effects of aspirin on human coronary artery endothelial cells (HCAECs) and explore its underlying mechanisms. HCAECs were treated with oxidized low-density lipoprotein (ox-LDL), angiotensin II (Ang-II), or high glucose (HG) with or without aspirin stimulation. The expression levels of endothelial nitric oxide (NO) synthase (eNOS), p-eNOS, LC3, p62, phosphor-nuclear factor kappa B (p-NF-κB), p-p38 mitogen-activated protein kinase (p-p38 MAPK), and Beclin-1 were detected via immunoblotting analysis. Concentrations of soluble intercellular adhesion molecule-1 (sICAM-1) and soluble vascular cell adhesion molecule-1 (sVCAM-1) were measured via ELISA. NO levels were determined using the Griess reagent. Autophagic flux was tracked by tandem mRFP-GFP-tagged LC3. Results showed that aspirin increased eNOS level and reduced injury to the endothelial cells (ECs) caused by ox-LDL, Ang-II, and HG treatment in a dose-dependent manner. Aspirin also increased the LC3II/LC3I ratio, decreased p62 expression, and enhanced autophagic flux (autophagosome and autolysosome puncta) in the HCAECs. p-NF-κB and p-p38 mitogen-activated protein kinase inhibition, sVCAM-1 and sICAM-1 secretion, and eNOS activity promotion by aspirin treatment were found to be dependent on Beclin-1. These results suggested that aspirin can protect ECs from ox-LDL-, Ang-II-, and HG-induced injury by activating autophagy in a Beclin-1-dependent manner.

Regulation of Autophagy by Non-Steroidal Anti-Inflammatory Drugs in Cancer

Cancer is the leading cause of death, placing a substantial global health burden. The development of the most effective treatment regimen is the unmet clinical need for cancer. Inflammation plays a role in tumorigenesis and progression, and anti-inflammation may be a promising option for cancer management and prevention. Emerging studies have shown that non-steroidal anti-inflammatory drugs (NSAIDs) display anticarcinogenic and chemopreventive properties through the regulation of autophagy in certain types of cancer. In this review, we summarize the pharmacological functions and side effects of NSAIDs as chemotherapeutic agents, and focus on its mode of action on autophagy regulation, which increases our knowledge of NSAIDs and cancer-related inflammation, and contributes to a putative addition of NSAIDs in the chemoprevention and treatment of cancer.

Insulin Resistance in Osteoarthritis: Similar Mechanisms to Type 2 Diabetes Mellitus

Osteoarthritis (OA) and type 2 diabetes mellitus (T2D) are two of the most widespread chronic diseases. OA and T2D have common epidemiologic traits, are considered heterogenic multifactorial pathologies that develop through the interaction of genetic and environmental factors, and have common risk factors. In addition, both of these diseases often manifest in a single patient. Despite differences in clinical manifestations, both diseases are characterized by disturbances in cellular metabolism and by an insulin-resistant state primarily associated with the production and utilization of energy. However, currently, the primary cause of OA development and progression is not clear. In addition, although OA is manifested as a joint disease, evidence has accumulated that it affects the whole body. As pathological insulin resistance is viewed as a driving force of T2D development, now, we present evidence that the molecular and cellular metabolic disturbances associated with OA are linked to an insulin-resistant state similar to T2D. Moreover, the alterations in cellular energy requirements associated with insulin resistance could affect many metabolic changes in the body that eventually result in pathology and could serve as a unified mechanism that also functions in many metabolic diseases. However, these issues have not been comprehensively described. Therefore, here, we discuss the basic molecular mechanisms underlying the pathological processes associated with the development of insulin resistance; the major inducers, regulators, and metabolic consequences of insulin resistance; and instruments for controlling insulin resistance as a new approach to therapy.

Repurposing of drugs: An attractive pharmacological strategy for cancer therapeutics

Human malignancies are one of the major health-related issues though out the world and anticipated to rise in the future. The development of novel drugs/agents requires a huge amount of cost and time that represents a major challenge for drug discovery. In the last three decades, the number of FDA approved drugs has dropped down and this led to increasing interest in drug reposition or repurposing. The present review focuses on recent concepts and therapeutic opportunities for the utilization of antidiabetics, antibiotics, antifungal, anti-inflammatory, antipsychotic, PDE inhibitors and estrogen receptor antagonist, Antabuse, antiparasitic and cardiovascular agents/drugs as an alternative approach against human malignancies. The repurposing of approved non-cancerous drugs is an effective strategy to develop new therapeutic options for the treatment of cancer patients at an affordable cost in clinics. In the current scenario, most of the countries throughout the globe are unable to meet the medical needs of cancer patients because of the high cost of the available cancerous drugs. Some of these drugs displayed potential anti-cancer activity in preclinic and clinical studies by regulating several key molecular mechanisms and oncogenic pathways in human malignancies. The emerging pieces of evidence indicate that repurposing of drugs is crucial to the faster and cheaper discovery of anti-cancerous drugs.

Deactivation of Glutaminolysis Sensitizes PIK3CA-Mutated Colorectal Cancer Cells to Aspirin-Induced Growth Inhibition

Aspirin is one of the most promising over-the-counter drugs to repurpose for cancer treatment. In particular, aspirin has been reported to be effective against PIK3CA-mutated colorectal cancer (CRC); however, little information is available on how the PIK3CA gene status affects its efficacy. We found that the growth inhibitory effects of aspirin were impaired upon glutamine deprivation in PIK3CA-mutated CRC cells. Notably, glutamine dependency of aspirin-mediated growth inhibition was observed in PIK3CA-mutated cells but not PIK3CA wild type cells. Mechanistically, aspirin induced G1 arrest in PIK3CA-mutated CRC cells and inhibited the mTOR pathway, inducing the same phenotypes as glutamine deprivation. Moreover, our study including bioinformatic approaches revealed that aspirin increased the expression levels of glutaminolysis-related genes with upregulation of activating transcription factor 4 (ATF4) in PIK3CA-mutated CRC cells. Lastly, the agents targeting glutaminolysis demonstrated significant combined effects with aspirin on PIK3CA-mutated CRC cells. Thus, these findings not only suggest the correlation among aspirin efficacy, PIK3CA mutation and glutamine metabolism, but also the rational combinatorial treatments of aspirin with glutaminolysis-targeting agents against PIK3CA-mutated CRC.

Aspirin-targeted PD-L1 in lung cancer growth inhibition

Background

Aspirin is a classic anti‐inflammatory drug and its anticancer effect has been previously explored in many types of cancer including colorectal cancer therapy. Programmed cell death‐ligand 1 (PD‐L1) is widely expressed in tumor cells and displays an inhibitory role in antitumor immunity. This study aimed to clarify the role of PD‐L1 in aspirin‐suppressed lung cancer.

Methods

The inhibitory effect of aspirin on lung cancer cell proliferation was assessed using an MTT cell viability assay. The role of aspirin in the modulation of PD‐L1 expression was analyzed by western blot or RT‐PCR assays. In lung cancer cells, the influence of aspirin on PD‐L1 promoter activity was detected using a luciferase reporter assay. The interaction of TAZ with PD‐L1 promoter in the cells, with or without aspirin administration, was tested via chromatin immunoprecipitation (ChIP) analysis. The function of PD‐L1 in aspirin‐mediated growth inhibition of lung cancer was examined using a cell viability assay.

Results

Following treatment with aspirin, lung cancer cell growth was markedly suppressed. Aspirin was able to markedly decrease the expression of PD‐L1 at the mRNA and protein levels in lung cancer cells. For the mechanism study, we found that the promoter of PD‐L1 was inactivated by aspirin via TAZ transcriptional coactivator in the cells. With regard to the functional investigation, aspirin was capable of resisting cell proliferation and PD‐L1 overexpression abolished aspirin‐depressed cell proliferation in lung cancer.

Conclusions

Aspirin suppressed the growth of lung cancer cells via targeting the TAZ/PD‐L1 axis.

Protein and Mitochondria Quality Control Mechanisms and Cardiac Aging

Cardiovascular disease (CVD) is the number one cause of death in the United States. Advancing age is a primary risk factor for developing CVD. Estimates indicate that 20% of the US population will be ≥65 years old by 2030. Direct expenditures for treating CVD in the older population combined with indirect costs, secondary to lost wages, are predicted to reach $1.1 trillion by 2035. Therefore, there is an eminent need to discover novel therapeutic targets and identify new interventions to delay, lessen the severity, or prevent cardiovascular complications associated with advanced age. Protein and organelle quality control pathways including autophagy/lysosomal and the ubiquitin-proteasome systems, are emerging contributors of age-associated myocardial dysfunction. In general, two findings have sparked this interest. First, strong evidence indicates that cardiac protein degradation pathways are altered in the heart with aging. Second, it is well accepted that damaged and misfolded protein aggregates and dysfunctional mitochondria accumulate in the heart with age. In this review, we will: (i) define the different protein and mitochondria quality control mechanisms in the heart; (ii) provide evidence that each quality control pathway becomes dysfunctional during cardiac aging; and (iii) discuss current advances in targeting these pathways to maintain cardiac function with age.

Modulating the Distant Spreading of Patient-Derived Colorectal Cancer Cells via Aspirin and Metformin

Although screening has reduced mortality rates for colorectal cancer (CRC), about 20% of patients still carry metastases at diagnosis. Postsurgery chemotherapy is toxic and induces drug resistance. Promising alternative strategies rely on repurposing drugs such as aspirin (ASA) and metformin (MET). Here, tumor spheroids were generated in suspension by primary CRCs and metastatic lymph nodes from 11 patients. These spheroids presented a heterogeneous cell population including a small core of CD133+/ESA+ cancer stem cells surrounded by a thick corona of CDX2+/CK20+ CRC cells, thus maintaining the molecular hallmarks of the tumor source. Spheroids were exposed to ASA and/or MET at different doses for up to 7 days to assess cell growth, migration, and adhesion in three-dimensional assays. While ASA at 5 mM was always sufficient to mitigate cell migration, the response to MET was patient specific. Only in MET-sensitive spheroids, the 5 mM ASA/MET combination showed an effect. Interestingly, CRCs from diabetic patients daily pretreated with MET gave a very low spheroid yield due to reduced cancer cell survival. This study highlights the potential of ASA/MET treatments to modulate CRC spreading.

MicroRNA-126 Inhibit Viability of Colorectal Cancer Cell by Repressing mTOR Induced Apoptosis and Autophagy

OBJECTIVE

Colorectal cancer (CRC) is a fatal disease, and tumor development is a complex cellular event involving a multistep cascade process involving proliferation, invasion, and migration. In recent years, it has been shown that microRNA-126 (miR-126) plays a key role in the tumorigenesis of CRC, but further studies are required to investigate the regulatory mechanisms through which this miRNA affects cell viability, autophagy, and apoptosis in CRC. We aimed to study the effect of miR-126 in gene regulation in CRC HCT116 cells.

METHODS

CRC biopsy samples and normal colorectal tissue samples were used for miRNA profiling. Real-time quantitative PCR and WB were utilized to detect RNA and protein levels. MTT and colony formation assays were performed to examine cell viability. Furthermore, an immunofluorescence assay and Annexin V/PI flow cytometry were performed to detect autophagy and apoptosis, respectively.

RESULTS

The expression of miR-126 was downregulated in CRC biopsies and cell lines compared with that in normal cells and tissues. The upregulation of miR-126 resulted in impaired viability and growth of CRC cells. Furthermore, with the overexpression of miR-126, cell autophagy was increased, as evidenced by LC3-I/II transformation and p62 degradation. Meanwhile, apoptosis induction was also observed because of the increased miR-126 levels. The autophagy inhibitor Bafilomycin A1 (BafA1) repressed both autophagy and apoptosis, indicating that miR-126 induced autophagy was responsible for the induction of apoptosis. A dual-luciferase reporter assay (DLRA) and bioinformatics prediction revealed that miR-126 silenced the mTOR gene by targeting the 3'-UTR. mTOR mRNA levels in CRC biopsy tissues and cell lines were upregulated to a greater extent than that in normal cells and tissues. Furthermore, HCT116 cells transfected with an miR-126 mimic showed a decreased expression of mTOR. In addition, the overexpression of mTOR counteracted miR-126 on autophagy and apoptosis.

CONCLUSION

Our study demonstrated that miR-126-induced can regulate the activity of CRC cells via autophagy and apoptosis and suggested a new mechanism of miR-126-mTOR interaction in CRC pathogenesis.

Salicylate suppresses the oncogenic hyaluronan network in metastatic breast cancer cells

The oncogenic role of hyaluronan in several aspects of tumor biology has been well established. Recent studies by us and others suggest that inhibition of hyaluronan synthesis could represent an emerging therapeutic approach with significant clinical relevance in controlling different breast cancer subtypes, including triple-negative breast cancer. Epidemiological and preclinical studies have revealed the therapeutic potential of aspirin (acetyl salicylate), a classical anti-inflammatory drug, in patients with cancer. However, the underlying molecular mechanisms remain unknown. The present study demonstrates that salicylate, a break down product of aspirin in vivo, alters the organization of hyaluronan matrices by affecting the expression levels of hyaluronan synthesizing (HAS1, 2, 3) and degrading (HYAL-1, -2) enzymes, and that of hyaluronan receptor CD44. In particular, salicylate was found to potently activate AMPK, a kinase known to inhibit HAS2 activity, and caused a dose-dependent decrease of cell associated (intracellular and membrane-bound) as well as secreted hyaluronan, followed by the down-regulation of HAS2 and the induction of HYAL-2 and CD44 in metastatic breast cancer cells. These salicylate-mediated effects were associated with the redistribution of CD44 and actin cytoskeleton that resulted in a less motile cell phenotype. Interestingly, salicylate inhibited metastatic breast cancer cell proliferation and growth by inducing cell growth arrest without signs of apoptosis as evidenced by the substantial decrease of cyclin D1 protein and the absence of cleaved caspase-3, respectively. Collectively, our study offers a possible direction for the development of new matrix-based targeted treatments of metastatic breast cancer subtypes via inhibition of hyaluronan, a pro-angiogenic, pro-inflammatory and tumor promoting glycosaminoglycan.

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.

Aspirin exerts anti-tumor effect through inhibiting Blimp1 and activating ATF4/CHOP pathway in multiple myeloma

B lymphocyte-induced maturation protein-1 (Blimp1) is a key regulator that promotes the terminal differentiation of mature B lymphocytes into plasma cells, and is essential for the survival of Multiple myeloma (MM)cells. However, the expression of Blimp1 in MM and its effect on the signaling pathway remain unknown. Studies have found that during long-term endoplasmic reticulum (ER) stress, activated ATF4 may also stimulate the CCAAT-enhancer-binding protein homologous protein (CHOP) gene, triggering the unfolded protein response (UPR) terminal apoptotic pathway in plasma cells. Moreover Aspirin can induce MM cell apoptosis through mitochondria and death receptor pathway. Therefore, we aim to explore whether Aspirin could induce AFT4/CHOP apoptosis pathway in MM by inhibiting Blimp1 expression, thereby promoting MM cell apoptosis and exerting anti-tumor effects.

How autophagy can restore proteostasis defects in multiple diseases?

Cellular evolution develops several conserved mechanisms by which cells can tolerate various difficult conditions and overall maintain homeostasis. Autophagy is a well-developed and evolutionarily conserved mechanism of catabolism, which endorses the degradation of foreign and endogenous materials via autolysosome. To decrease the burden of the ubiquitin-proteasome system (UPS), autophagy also promotes the selective degradation of proteins in a tightly regulated way to improve the physiological balance of cellular proteostasis that may get perturbed due to the accumulation of misfolded proteins. However, the diverse as well as selective clearance of unwanted materials and regulations of several cellular mechanisms via autophagy is still a critical mystery. Also, the failure of autophagy causes an increase in the accumulation of harmful protein aggregates that may lead to neurodegeneration. Therefore, it is necessary to address this multifactorial threat for in-depth research and develop more effective therapeutic strategies against lethal autophagy alterations. In this paper, we discuss the most relevant and recent reports on autophagy modulations and their impact on neurodegeneration and other complex disorders. We have summarized various pharmacological findings linked with the induction and suppression of autophagy mechanism and their promising preclinical and clinical applications to provide therapeutic solutions against neurodegeneration. The conclusion, key questions, and future prospectives sections summarize fundamental challenges and their possible feasible solutions linked with autophagy mechanism to potentially design an impactful therapeutic niche to treat neurodegenerative diseases and imperfect aging.

HYAL-1-induced autophagy facilitates pancreatic fistula for patients who underwent pancreaticoduodenectomy

The main mechanism of hyaluronidase 1(HYAL-1) in the development of postoperative pancreatic fistula (POPF) after pancreatoduodenectomy (PD) was unknown. In this study, a comprehensive inventory of pre-, intra-, and postoperative clinical and biological data of two cohorts (62 pancreatic cancer [PCa] and 111 pancreatic ductal adenocarcinoma [PDAC]) which could induce POPF were retrospectively analyzed. Then, a total of 7644 genes correlated with HYAL-1 was predicted in PDAC tissues and the enriched pathway, kinase targets and biological process of those correlated genes were evaluated. Finally, a mouse pancreatic fistula (PF) model was first built and in vitro studies were performed to investigate the effects of HYAL-1 on PF progression. Our data indicated that preoperative serum HYAL-1 level, pancreatic fibrosis score, and pancreatic duct size were valuable factors for detecting POPF of Grade B and C. The serum HYAL-1 level of 2.07 mg/ml and pancreatic fibrosis score of 2.5 were proposed as the cutoff values for indicating POPF. The bioinformatic analysis and in vitro and in vivo studies demonstrated that HYAL-1 facilitates pancreatic acinar cell autophagy via the dephosphorylation of adenosine 5'-monophosphate-activated protein kinase (AMPK) and signal transducers and activators of transcription 3 (STAT3) signaling pathways, which exacerbate pancreatic secretion and inflammation. In summary, the preoperative serum HYAL-1 was a significant predictor for POPF in patients who underwent PD. Tumor-induced HYAL-1 is one of core risk in accelerating PF and then promoting pancreatic secretion and acute inflammation response through the AMPK and STAT3-induced autophagy.

Effects of chronic low-dose aspirin treatment on tumor prevention in three mouse models of intestinal tumorigenesis

Although early detection and treatment of colorectal cancer (CRC) have improved, it remains a significant health-care problem with high morbidity and mortality. Data indicate that long-term intake of low-dose aspirin reduces the risk of CRC; however, the mechanisms underlying this chemopreventive effect are still unclear. Different mouse models for inflammation-associated, sporadic, and hereditary CRC were applied to assess the efficacy and mechanism of low-dose aspirin on tumor prevention. An initial dosing study performed in healthy mice indicates that aspirin at a dose of 25 mg/kg/d has a similar pharmacodynamic effect as low-dose aspirin treatment in human subjects (100 mg/d). Chronic low-dose aspirin treatment suppresses colitis-associated and to a lesser extent spontaneous tumorigenesis in mice. Aspirin's antitumor effect is most pronounced in a preventive approach when aspirin administration starts before the tumor-initiating genotoxic event and continues for the duration of the experiment. These effects are not associated with alterations in cell proliferation, apoptosis, or activation of signaling pathways involved in CRC. Aspirin-induced reduction in tumor burden is accompanied by inhibition of thromboxane B₂ formation, indicating reduced platelet activation. Aspirin treatment also results in decreased colonic prostaglandin E₂ formation and tumor angiogenesis. With respect to colitis-triggered tumorigenesis, aspirin administration is associated with a reduction in inflammatory activity in the colon, as indicated by decreased levels of pro-inflammatory mediators, and tumor-associated iNOS-positive macrophages. Our results suggest that low-dose aspirin represents an effective antitumor agent in the context of colon tumorigenesis primarily due to its well-established cyclooxygenase inhibition effects.

MiR-107 confers chemoresistance to colorectal cancer by targeting calcium-binding protein 39

Background

Chemoresistance remains a critical event that accounts for colorectal cancer (CRC) lethality. The aim of this study is to explore the ability of dichloroacetate (DCA) to increase chemosensitivity in CRC and the molecular mechanisms involved.

Methods

The effects of combination treatment of DCA and oxaliplatin (L-OHP) were analysed both in vitro and in vivo. The DCA-responsive proteins in AMPK pathway were enriched using proteomic profiling technology. The effect of DCA on CAB39–AMPK signal pathway was analysed. In addition, miRNA expression profiles after DCA treatment were determined. The DCA-responsive miRNAs that target CAB39 were assayed. Alterations of CAB39 and miR-107 expression were performed both in vitro and on xenograft models to identify miR-107 that targets CAB39–AMPK–mTOR signalling pathway.

Results

DCA increased L-OHP chemosensitivity both in vivo and in vitro. DCA could upregulate CAB39 expression, which activates the AMPK/mTOR signalling pathway. CAB39 was confirmed to be a direct target of miR-107 regulated by DCA. Alterations of miR-107 expression were correlated with chemoresistance development in CRC both in vitro and in vivo.

Conclusion

These findings suggest that the miR-107 induces chemoresistance through CAB39–AMPK–mTOR pathway in CRC cells, thus providing a promising target for overcoming chemoresistance in CRC.

ASA Suppresses PGE2 in Plasma and Melanocytic Nevi of Human Subjects at Increased Risk for Melanoma

Potential anti-inflammatory and anticarcinogenic effects of aspirin (ASA) may be suitable for melanoma chemoprevention, but defining biomarkers in relevant target tissues is prerequisite to performing randomized controlled chemoprevention trials. We conducted open-label studies with ASA in 53 human subjects with melanocytic nevi at increased risk for melanoma. In a pilot study, 12 subjects received a single dose (325 mg) of ASA; metabolites salicylate, salicylurate, and gentisic acid were detected in plasma after 4-8 h, and prostaglandin E2 (PGE2) was suppressed in both plasma and nevi for up to 24 h. Subsequently, 41 subjects received either 325 or 81 mg ASA (nonrandomized) daily for one week. ASA metabolites were consistently detected in plasma and nevi, and PGE2 levels were significantly reduced in both plasma and nevi. Subchronic ASA dosing did not affect 5" adenosine monophosphate-activated protein kinase (AMPK) activation in nevi or leukocyte subsets in peripheral blood, although metabolomic and cytokine profiling of plasma revealed significant decreases in various (non-ASA-derived) metabolites and inflammatory cytokines. In summary, short courses of daily ASA reduce plasma and nevus PGE2 and some metabolites and cytokines in plasma of human subjects at increased risk for melanoma. PGE2 may be a useful biomarker in blood and nevi for prospective melanoma chemoprevention studies with ASA.

Compound C enhances the anticancer effect of aspirin in HER-2-positive breast cancer by regulating lipid metabolism in an AMPK-independent pathway

Various clinical studies have determined that aspirin shows anticancer effects in many human malignant cancers, including human epidermal growth factor receptor-2 (HER-2)-positive breast cancer. However, the anti-tumor mechanism of aspirin has not been fully defined. The aim of this study was to determine the role of Compound C in enhancing the anticancer effect of aspirin. HER-2-positive breast cancer cell lines were treated with aspirin with or without Compound C pre-treatment; their phenotypes and mechanisms were then analyzed in vitro and in vivo. Aspirin exhibited anticancer effects in HER-2-positive breast cancer by inhibiting cell growth and inducing apoptosis through the activation of AMP-activated protein kinase (AMPK). Unexpectedly, pre-treatment with Compound C, a widely used AMPK inhibitor, induced robust anticancer effects in cells compared to aspirin monotherapy. This anticancer effect was not distinct in HER-2 negative breast cancer MDA-MB-231 cells and may be due to the inhibition of lipid metabolism mediated by c-myc. Besides, c-myc re-expression or palmitic acid supply could partially restored cell proliferation. Aspirin exhibits anticancer effects in HER-2-positive breast cancer by regulating lipid metabolism mediated by c-myc, and Compound C strengthens these effects in an AMPK-independent manner. Our results potentially provide a novel therapeutic strategy exploiting combined aspirin and Compound C therapy for HER-2-positive breast cancer, which acts by reducing de novo lipid synthesis.

The role of aspirin in the prevention of ovarian, endometrial and cervical cancers

Drug repurposing is the application of an existing licenced drug for a new indication and potentially provides a faster and cheaper approach to developing new anti-cancer agents. Gynaecological cancers contribute significantly to the global cancer burden, highlighting the need for low cost, widely accessible therapies. A large body of evidence supports the role of aspirin as an anti-cancer agent, and a number of randomized trials are currently underway aiming to assess the potential benefit of aspirin in the treatment of cancer. This review summarizes the evidence underpinning aspirin use for the prevention of the development and recurrence of gynaecological cancers (ovarian, endometrial and cervical) and potential mechanisms of action.

Pyrazole-4-Carboxamide (YW2065): A Therapeutic Candidate for Colorectal Cancer via Dual Activities of Wnt/β-Catenin Signaling Inhibition and AMP-Activated Protein Kinase (AMPK) Activation

Dysregulation of the Wnt/β-catenin signaling pathway has been widely recognized as a pathogenic mechanism for colorectal cancer (CRC). Although numerous Wnt inhibitors have been developed, they commonly suffer from toxicity and unintended effects. Moreover, concerns have been raised in targeting this pathway because of its critical roles in maintaining stem cells and regenerating tissues and organs. On the basis of the anthelmintic drug pyrvinium and previous lead FX1128, we have developed a compound YW2065 (1c) which demonstrated excellent anti-CRC effects in vitro and in vivo. YW2065 achieves its inhibitory activity for Wnt signaling by stabilizing Axin-1, a scaffolding protein that regulates proteasome degradation of β-catenin. Simultaneously, YW2065 also led to the activation of the tumor suppressor AMPK, providing an additional anticancer mechanism. In addition, YW2065 showed favorable pharmacokinetic properties without obvious toxicity. The anti-CRC effect of YW2065 was highlighted by its promising efficacy in a mice xenograft model.

A Phase IIa Trial of Metformin for Colorectal Cancer Risk Reduction among Individuals with History of Colorectal Adenomas and Elevated Body Mass Index

Obesity is associated with risk of colorectal adenoma (CRA) and colorectal cancer. The signaling pathway activated by metformin (LKB1/AMPK/mTOR) is implicated in tumor suppression in Apc^Min/+ mice via metformin-induced reduction in polyp burden, increased ratio of pAMPK/AMPK, decreased pmTOR/mTOR ratio, and decreased pS6^Ser235/S6^Ser235 ratio in polyps. We hypothesized that metformin would affect colorectal tissue S6^Ser235 among obese patients with recent history of CRA. A phase IIa clinical biomarker trial was conducted via the U.S. National Cancer Institute-Chemoprevention Consortium. Nondiabetic, obese subjects (BMI ≥30) ages 35 to 80 with recent history of CRA were included. Subjects received 12 weeks of oral metformin 1,000 mg twice every day. Rectal mucosa biopsies were obtained at baseline and end-of-treatment (EOT) endoscopy. Tissue S6^Ser235 and Ki-67 immunostaining were analyzed in a blinded fashion using Histo score (Hscore) analysis. Among 32 eligible subjects, the mean baseline BMI was 34.9. Comparing EOT to baseline tissue S6^Ser235 by IHC, no significant differences were observed. Mean (SD) Hscore at baseline was 1.1 (0.57) and 1.1 (0.51) at EOT; median Hscore change was 0.034 (P = 0.77). Similarly, Ki-67 levels were unaffected by the intervention. The adverse events were consistent with metformin's known side-effect profile. Among obese patients with CRA, 12 weeks of oral metformin does not reduce rectal mucosa pS6 or Ki-67 levels. Further research is needed to determine what effects metformin has on the target tissue of origin as metformin continues to be pursued as a colorectal cancer chemopreventive agent.

Aspirin metabolites 2,3‑DHBA and 2,5‑DHBA inhibit cancer cell growth: Implications in colorectal cancer prevention

Although compelling evidence exists on the ability of aspirin to treat colorectal cancer (CRC), and numerous theories and targets have been proposed, a consensus has not been reached regarding its mechanism of action. In this regard, a relatively unexplored area is the role played by aspirin metabolites 2,3-dihydroxybenzoic acid (2,3-DHBA) and 2,5-dihydroxybenzoic acid (2,5-DHBA) in its chemopreventive actions. In a previous study, we demonstrated that 2,3-DHBA and 2,5-DHBA inhibited CDK1 enzyme activity in vitro. The aim of the present study was to understand the effect of these metabolites on the enzyme activity of all CDKs involved in cell cycle regulation (CDKs 1, 2, 4 and 6) as well as their effect on clonal formation in three different cancer cell lines. Additionally, in silico studies were performed to determine the potential sites of interactions of 2,3-DHBA and 2,5-DHBA with CDKs. We demonstrated that 2,3-DHBA and 2,5-DHBA inhibits CDK-1 enzyme activity beginning at 500 µM, while CDK2 and CDK4 activity was inhibited only at higher concentrations (>750 µM). 2,3-DHBA inhibited CDK6 enzyme activity from 250 µM, while 2,5-DHBA inhibited its activity >750 µM. Colony formation assays showed that 2,5-DHBA was highly effective in inhibiting clonal formation in HCT-116 and HT-29 CRC cell lines (250–500 µM), and in the MDA-MB-231 breast cancer cell line (~100 µM). In contrast 2,3-DHBA was effective only in MDA-MB-231 cells (~500 µM). Both aspirin and salicylic acid failed to inhibit all four CDKs and colony formation. Based on the present results, it is suggested that 2,3-DHBA and 2,5-DHBA may contribute to the chemopreventive properties of aspirin, possibly through the inhibition of CDKs. The present data and the proposed mechanisms should open new areas for future investigations.

Biological Functions of Autophagy Genes: A Disease Perspective

The lysosomal degradation pathway of autophagy plays a fundamental role in cellular, tissue, and organismal homeostasis and is mediated by evolutionarily conserved autophagy-related (ATG) genes. Definitive etiological links exist between mutations in genes that control autophagy and human disease, especially neurodegenerative, inflammatory disorders and cancer. Autophagy selectively targets dysfunctional organelles, intracellular microbes, and pathogenic proteins, and deficiencies in these processes may lead to disease. Moreover, ATG genes have diverse physiologically important roles in other membrane-trafficking and signaling pathways. This Review discusses the biological functions of autophagy genes from the perspective of understanding-and potentially reversing-the pathophysiology of human disease and aging.

The Function of Autophagy in Lace Plant Programmed Cell Death

The lace plant (Aponogeton madagascariensis) is an aquatic monocot that utilizes programmed cell death (PCD) to form perforations throughout its mature leaves as part of normal development. The lace plant is an emerging model system representing a unique form of developmental PCD. The role of autophagy in lace plant PCD was investigated using live cell imaging, transmission electron microscopy (TEM), immunolocalization, and in vivo pharmacological experimentation. ATG8 immunostaining and acridine orange staining revealed that autophagy occurs in both healthy and dying cells. Autophagosome-like vesicles were also found in healthy and dying cells through ultrastructural analysis with TEM. Following autophagy modulation, there was a noticeable increase in vesicles and vacuolar aggregates. A novel cell death assay utilizing lace plant leaves revealed that autophagy enhancement with rapamycin significantly decreased cell death rates compared to the control, whereas inhibition of autophagosome formation with wortmannin or blocking the degradation of cargoes with concanamycin A had an opposite effect. Although autophagy modulation significantly affected cell death rates in cells that are destined to die, neither the promotion nor inhibition of autophagy in whole plants had a significant effect on the number of perforations formed in lace plant leaves. Our data indicate that autophagy predominantly contributes to cell survival, and we found no clear evidence for its direct involvement in the induction of developmental PCD during perforation formation in lace plant leaves.

Anti-tumor effects of the ethanolic extract of Trichosanthes kirilowii seeds in colorectal cancer

Background

Trichosanthis semen, the seeds of Trichosanthes kirilowii Maxim. or Trichosanthes rosthornii Harms, has long been used in Korean medicine to loosen bowels and relieve chronic constipation. Although the fruits and radixes of this medicinal herb and their constituents have been reported to exhibit therapeutic effects in various cancers, the anti-cancer effects of its seeds have been relatively less studied. In this study, we investigated the effects of an ethanolic extract of T. kirilowii seeds (TKSE) against colorectal cancer and its mechanism.

Methods

The anti-tumor effects of the TKSE were evaluated in HT-29 and CT-26 colorectal cancer cells and in a CT-26 tumor-bearing mouse model.

Results

TKSE suppressed the growth of HT-29 and CT-26 cells (both colorectal cancer cell lines) and the cytotoxic effect of TKSE was greater than that of 5-fluorouracil (5-Fu) in HT-29 cells. TKSE significantly induced mitochondrial membrane potential loss in HT-29 and CT-26 cells and dose-dependently inhibited Bcl-2 expression and induced the cleavages of caspase-3 and PARP. In particular, TKSE at 300 µg/mL induced nuclear condensation and fragmentation in HT-29 cells. Furthermore, TKSE dose-dependently inhibited activations of the Akt/mTOR and ERK pathways, and markedly induced the phosphorylation of AMPK. An AMPKα inhibitor (compound C) effectively blocked the TKSE-induced mitochondrial dysfunction. In addition, TKSE attenuated the hypoxia-inducible factor-1α/vascular endothelial growth factor signaling pathway in HT-29 cells under hypoxic-mimic conditions and inhibited migration and invasion. Oral administration of TKSE (100 or 300 mg/kg) inhibited tumor growth in a mouse CT-26 allograft model but was not as effective as 5-Fu (the positive control), which was administered intraperitoneally. In the same model, 5-Fu caused significant body weight loss, but no such loss was observed in TKSE-treated mice.

Conclusion

Taken together, these results suggest TKSE has potent anti-tumor effects which might be partly due to the activation of AMPK, and the induction mitochondrial-mediated apoptosis in colorectal cancer cells. These findings provide scientific evidence supporting the potential use of TKSE as a complementary and alternative medicine for the treatment of colorectal cancer.

Diflunisal targets the HMGB1/CXCL12 heterocomplex and blocks immune cell recruitment

Extracellular HMGB1 triggers inflammation following infection or injury and supports tumorigenesis in inflammation-related malignancies. HMGB1 has several redox states: reduced HMGB1 recruits inflammatory cells to injured tissues forming a heterocomplex with CXCL12 and signaling via its receptor CXCR4; disulfide-containing HMGB1 binds to TLR4 and promotes inflammatory responses. Here we show that diflunisal, an aspirin-like nonsteroidal anti-inflammatory drug (NSAID) that has been in clinical use for decades, specifically inhibits in vitro and in vivo the chemotactic activity of HMGB1 at nanomolar concentrations, at least in part by binding directly to both HMGB1 and CXCL12 and disrupting their heterocomplex. Importantly, diflunisal does not inhibit TLR4-dependent responses. Our findings clarify the mode of action of diflunisal and open the way to the rational design of functionally specific anti-inflammatory drugs.

A Systems Biology Roadmap to Decode mTOR Control System in Cancer

Mechanistic target of rapamycin (mTOR) is a critical protein in the regulation of cell fate decision making, especially in cancer cells. mTOR acts as a signal integrator and is one of the main elements of interactions among the pivotal cellular processes such as cell death, autophagy, metabolic reprogramming, cell growth, and cell cycle. The temporal control of these processes is essential for the cellular homeostasis and dysregulation of mTOR signaling pathway results in different phenotypes, including aging, oncogenesis, cell survival, cell growth, senescence, quiescence, and cell death. In this paper, we have proposed a systems biology roadmap to study mTOR control system, which introduces the theoretical and experimental modalities to decode temporal and dynamical characteristics of mTOR signaling in cancer.

Drug repurposing to overcome resistance to various therapies for colorectal cancer

Emergence of novel treatment modalities provides effective therapeutic options, apart from conventional cytotoxic chemotherapy, to fight against colorectal cancer. Unfortunately, drug resistance remains a huge challenge in clinics, leading to invariable occurrence of disease progression after treatment initiation. While novel drug development is unfavorable in terms of time frame and costs, drug repurposing is one of the promising strategies to combat resistance. This approach refers to the application of clinically available drugs to treat a different disease. With the well-established safety profile and optimal dosing of these approved drugs, their combination with current cancer therapy is suggested to provide an economical, safe and efficacious approach to overcome drug resistance and prolong patient survival. Here, we review both preclinical and clinical efficacy, as well as cellular mechanisms, of some extensively studied repurposed drugs, including non-steroidal anti-inflammatory drugs, statins, metformin, chloroquine, disulfiram, niclosamide, zoledronic acid and angiotensin receptor blockers. The three major treatment modalities in the management of colorectal cancer, namely classical cytotoxic chemotherapy, molecular targeted therapy and immunotherapy, are covered in this review.

Platelet-Specific Deletion of Cyclooxygenase-1 Ameliorates Dextran Sulfate Sodium-Induced Colitis in Mice

Inflammatory bowel disease (IBD) is associated with an increased risk for thromboembolism, platelet activation, and abnormalities in platelet number and size. In colitis, platelets can extravasate into the colonic interstitium. We generated a mouse with a specific deletion of cyclooxygenase (COX)-1 in megakaryocytes/platelets [(COX-1 conditional knockout (cKO)] to clarify the role of platelet activation in the development of inflammation and fibrosis in dextran sodium sulfate (DSS)-induced colitis. The disease activity index was assessed, and colonic specimens were evaluated for histologic features of epithelial barrier damage, inflammation, and fibrosis. Cocultures of platelets and myofibroblasts were performed. We found that the specific deletion of COX-1 in platelets, which recapitulated the human pharmacodynamics of low-dose aspirin, that is, suppression of platelet thromboxane (TX)A2 production associated with substantial sparing of the systemic production of prostacyclin, resulted in milder symptoms of colitis, in the acute phase, and almost complete recovery from the disease after DSS withdrawal. Reduced colonic accumulation of macrophages and myofibroblasts and collagen deposition was found. Platelet-derived TXA2 enhanced the ability of myofibroblasts to proliferate and migrate in vitro, and these effects were prevented by platelet COX-1 inhibition or antagonism of the TXA2 receptor. Our findings allow a significant advance in the knowledge of the role of platelet-derived TXA2 in the development of colitis and fibrosis in response to intestinal damage and provide the rationale to investigate the potential efficacy of the antiplatelet agent low-dose aspirin in limiting the inflammatory response and fibrosis associated with IBD. SIGNIFICANCE STATEMENT: Inflammatory bowel disease (IBD) is characterized by the development of a chronic inflammatory response, which can lead to intestinal fibrosis for which currently there is no medical treatment. Through the generation of a mouse with specific deletion of cyclooxygenase-1 in megakaryocytes/platelets, which recapitulates the human pharmacodynamics of low-dose aspirin, we demonstrate the important role of platelet-derived thromboxane A2 in the development of experimental colitis and fibrosis, thus providing the rationale to investigate the potential efficacy of low-dose aspirin in limiting the inflammation and tissue damage associated with IBD.

Effects of low-dose aspirin on clinical outcome and disease progression in patients with gastroenteropancreatic neuroendocrine neoplasm

Objective: The chemopreventive effect of aspirin (ASA) has been observed in the setting of colorectal cancer and other solid neoplasms. Recently, ASA has demonstrated a promising anti-proliferative effect on GEP-NENs in vitro. However, the direct anti-neoplastic impact of ASA on GEP-NEN clinical outcome is yet to be clarified. Materials and methods: All the GEP-NEN patients followed up in three European Centers from January 2005 to September 2016 were retrospectively enrolled. Patients taking ASA in doses of 75-100 mg daily for cardiovascular prevention for at least six months were evaluated. The possible association between ASA and disease grading, staging, primary site, OS and PFS were evaluated. Results: Two hundred fifty one patients were included (117 males, median age 63 years). Of these, 64 patients were prescribed with ASA. No clear impact on OS or PFS was observed in GEP-NEN patients taking ASA compared to those not taking it. ASA intake was related with the patients' older age. At Cox multivariate analysis, stage IV and Ki-67 resulted independent predictors for OS and PFS. In the setting of intestinal NENs, a suggestive, but not statistically significant, protective role of ASA on PFS was observed [HR 0.41 (95% CI: 0.13-1.29)]. Conclusions: Despite ASA showed promising anti-proliferative effects in vitro and a chemopreventive action in NENs has been reported, a clear impact of ASA on survival in NENs has not emerged from the present study. However, in the subgroup of patients with small-intestine NENs, ASA showed a trend toward a protective role.

Silencing of RHEB inhibits cell proliferation and promotes apoptosis in colorectal cancer cells via inhibition of the mTOR signaling pathway

Colorectal cancer (CRC) is commonly known as one of the most prominent reasons for cancer-related death in China. Ras homolog enriched in brain (RHEB) and the mammalian target activity of rapamycin (mTOR) signaling pathway were found correlated with CRC, but their specific interaction in CRC was still to be investigated. Therefore, we explored whether RHEB gene silencing affected the cell proliferation, differentiation, and apoptosis by directly targeting the mTOR signaling pathway in cells previously harvested from CRC patients. A microarray analysis was subsequently conducted to investigate the relationship between RHEB and mTOR. Eighty-three adjacent normal tissues and CRC tissues were selected. Immunohistochemistry was carried out to detect the positive expression rates of RHEB and Ki-67 in the CRC tissues. Cells were then transfected with different siRNAs to investigate the potential effects RHEB would have on CRC progression. The expressions of RHEB, 4EBP1, ribosomal protein S6 kinase (p70S6K), proliferating cell nuclear antigen (PCNA), B cell lymphoma 2 (bcl-2), and bcl-2-associated X protein (bax) were determined and then the cell cycle, cell proliferation, and apoptotic rate were also measured. We identified RHEB and mTOR as upregulated genes in CRC. Cells treated with RHEB silencing showed a decreased extent of mTOR, p70S6K, 4EBP1 phosphorylation and expression of RHEB, Ki-67, mTOR, p70S6K, 4EBP1, bcl-2, and PCNA as well as decreased activity of cell proliferation and differentiation; although, the expression of bax was evidently higher. Collectively, our data propose the idea that RHEB gene silencing might repress cell proliferation and differentiation while accelerating apoptosis via inactivating the mTOR signaling pathway.

Aspirin targets P4HA2 through inhibiting NF-κB and LMCD1-AS1/let-7g to inhibit tumour growth and collagen deposition in hepatocellular carcinoma

Background

Abnormal construction of the extracellular matrix (ECM) is intimately linked with carcinogenesis and the development of solid tumours, especially hepatocellular carcinoma (HCC). As the major component of the ECM, collagen plays a pivotal role in carcinogenesis. P4HA2, the essential enzyme during collagen formation, becomes an important target in HCC treatment. Here, we tried to decipher whether aspirin (ASA), a classic anti-inflammatory drug, could improve the prognosis of HCC through targeting P4HA2.

Methods

Western blotting, qRT-PCR assay, immunofluorescence staining, luciferase reporter gene assay, and ChIP assay were applied to demonstrate the molecular mechanism of the regulation of P4HA2 expression by aspirin. A mouse xenograft model, cell viability assay, colony formation assay, and immunohistochemistry analysis were used to evaluate the anti-fibrosis effect of aspirin through targeting the NF-κB/P4HA2 axis and LMCD1-AS1/let-7g/P4HA2 axis in vitro and in vivo. The TCGA database was used to evaluate the correlation among P4HA2, let-7g, LMCD1-AS1 and overall survival of HCC patients.

Findings

In xenograft mice, aspirin was capable of targeting P4HA2 to decrease collagen deposition, resulting in the inhibition of liver tumour growth. TCGA database analysis revealed the close association between a higher P4HA2 concentration in HCC patients and shorter overall survival or a higher cancer stage and the pathological grade. Mechanistically, NF-κB can bind to the promoter of P4HA2 to activate its transcription. Moreover, lncRNA LMCD1-AS1 functions as a molecular sponge of let-7g to post-transcriptionally induce the target gene of let-7g, namely, P4HA2.

Interpretation

Our findings disclose the novel role and regulatory mechanism of aspirin in the suppression of HCC by disrupting abnormal collagen deposition.

Funds

973 Program, National Natural Scientific Foundation of China, Fundamental Research Funds for the Central Universities, Project of Prevention and Control of Key Chronic Non-Infectious Diseases.

Aspirin Recapitulates Features of Caloric Restriction

The age-associated deterioration in cellular and organismal functions associates with dysregulation of nutrient-sensing pathways and disabled autophagy. The reactivation of autophagic flux may prevent or ameliorate age-related metabolic dysfunctions. Non-toxic compounds endowed with the capacity to reduce the overall levels of protein acetylation and to induce autophagy have been categorized as caloric restriction mimetics (CRMs). Here, we show that aspirin or its active metabolite salicylate induce autophagy by virtue of their capacity to inhibit the acetyltransferase activity of EP300. While salicylate readily stimulates autophagic flux in control cells, it fails to further increase autophagy levels in EP300-deficient cells, as well as in cells in which endogenous EP300 has been replaced by salicylate-resistant EP300 mutants. Accordingly, the pro-autophagic activity of aspirin and salicylate on the nematode Caenorhabditis elegans is lost when the expression of the EP300 ortholog cpb-1 is reduced. Altogether, these findings identify aspirin as an evolutionary conserved CRM.

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The aspirin metabolite, salicylate, competitively inhibits EP300 acetyltransferase

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EP300 inhibition is epistatic to autophagy induction by salicylate

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Aspirin triggers cardioprotective mitophagy in mice and nematodes

Health Benefits of Anti-aging Drugs

Aging, as a physiological process mediated by numerous regulatory pathways and transcription factors, is manifested by continuous progressive functional decline and increasing risk of chronic diseases. There is an increasing interest to identify pharmacological agents for treatment and prevention of age-related disease in humans. Animal models play an important role in identification and testing of anti-aging compounds; this step is crucial before the drug will enter human clinical trial or will be introduced to human medicine. One of the main goals of animal studies is better understanding of mechanistic targets, therapeutic implications and side-effects of the drug, which may be later translated into humans. In this chapter, we summarized the effects of different drugs reported to extend the lifespan in model organisms from round worms to rodents. Resveratrol, rapamycin, metformin and aspirin, showing effectiveness in model organism life- and healthspan extension mainly target the master regulators of aging such as mTOR, FOXO and PGC1α, affecting autophagy, inflammation and oxidative stress. In humans, these drugs were demonstrated to reduce inflammation, prevent CVD, and slow down the functional decline in certain organs. Additionally, potential anti-aging pharmacologic agents inhibit cancerogenesis, interfering with certain aspects of cell metabolism, proliferation, angioneogenesis and apoptosis.

Effects of 5-FU and anti-EGFR antibody in combination with ASA on the spherical culture system of HCT116 and HT29 colorectal cancer cell lines

The aim of this study was to examine the effects of 5‑fluorouracil (5‑FU), anti‑epidermal growth factor receptor (EGFR) antibody and aspirin (ASA) on the characteristics of two CRC cell lines, HCT116 and HT29, maintained in a spherical culture system. We observed that the morphology of both the HCT116 and HT29 cell‑derived spheres was significantly impaired and the size of the colonospheres was markedly reduced following treatment with the aforementioned three drugs. In contrast to adherent cultures, the spherical cultures were more resistant to the tested drugs, as was reflected by their capacity to re‑create the colonospheres when sustained in serum‑free medium. Flow cytometric analysis of the drug‑treated HCT116 cell‑derived spheres revealed changes in the fraction of cells expressing markers of cancer stem cells (CSCs), whereas the CSC phenotype of HT29 cell‑derived colonospheres was affected to a lesser extent. All reagents enhanced the percentage of non‑viable cells in the colonospheres despite the diminished fraction of active caspase‑3‑positive cells following treatment of the HT29 cell‑derived spheres with anti‑EGFR antibody. Increased autophagy, assessed by acridine orange staining, was noted following the incubation of the HT29‑colonospheres with ASA and 5‑FU in comparison to the control. Notably, the percentage of cyclooxygenase (COX)‑2‑positive cells was not affected by ASA, although its activity was markedly elevated in the colonospheres incubated with anti‑EGFR antibody. On the whole, the findings of this study indicate that all the tested drugs were involved in different cellular processes, which suggests that they should be considered for the combined therapeutic treatment of CRC, particularly for targeting the population of CSC‑like cells. Thus, cancer cell‑derived spheres may be used as a preferable model for in vitro anticancer drug testing.

Pro-survival autophagy and cancer cell resistance to therapy

Resistance to therapy is one of the prime causes for treatment failure in cancer and recurrent disease. In recent years, autophagy has emerged as an important cell survival mechanism in response to different stress conditions that are associated with cancer treatment and aging. Autophagy is an evolutionary conserved catabolic process through which damaged cellular contents are degraded after uptake into autophagosomes that subsequently fuse with lysosomes for cargo degradation, thereby alleviating stress. In addition, autophagy serves to maintain cellular homeostasis by enriching nutrient pools. Although autophagy can act as a double-edged sword at the interface of cell survival and cell death, increasing evidence suggest that in the context of cancer therapy-induced stress responses, it predominantly functions as a cell survival mechanism. Here, we provide an up-to-date overview on our current knowledge of the role of pro-survival autophagy in cancer therapy at the preclinical and clinical stages and delineate the molecular mechanisms of autophagy regulation in response to therapy-related stress conditions. A better understanding of the interplay of cancer therapy and autophagy may allow to unveil new targets and avenues for an improved treatment of therapy-resistant tumors in the foreseeable future.

Low-dose aspirin reduces hypoxia-induced sFlt1 release via the JNK/AP-1 pathway in human trophoblast and endothelial cells

Pre-eclampsia (PE) is a serious hypertensive disorder of pregnancy that remains a leading cause of perinatal and maternal morbidity and mortality worldwide. Placental ischemia/hypoxia and the secretion of soluble fms-like tyrosine kinase 1 (sFlt1) into maternal circulation are involved in the pathogenesis of PE. Although low-dose aspirin (LDA) has beneficial effects on the prevention of PE, the exact mechanisms of action of LDA, particularly on placental dysfunction, and sFlt1 release, have not been well investigated. This study aimed to determine whether LDA exists the protective effects on placental trophoblast and endothelial functions and prevents PE-associated sFlt1 release. First, we observed that LDA mitigated hypoxia-induced trophoblast apoptosis, showed positive effects on trophoblast cells migration and invasion activity, and increased the tube-forming activity of human umbilical vein endothelial cells (HUVECs). In addition, LDA decreased hypoxia-induced sFlt1 production, and the c-Jun NH₂ -terminal kinase/activator protein-1 (JNK/AP-1) pathway was shown to mediate the induction of sFlt1. Moreover, the transcription factor AP-1 was confirmed to regulate the Flt1 gene expression by directly binding to the Flt1 promoter in luciferase assays. The result of chromatin immunoprecipitation assays further demonstrated that LDA could directly decrease the expression of the transcription factor AP-1, and thus decrease sFlt1 production. Finally, the effects of LDA on sFlt1 production were proved in human placental explants. Taken together, our data show the protective effects of LDA against trophoblast and endothelial cell dysfunction and reveal that the LDA-mediated inhibition of sFlt1 via the JNK/AP-1 pathway may be a potential cellular/molecular mechanism for the prevention of PE.

HSP90 inhibitor DPB induces autophagy and more effectively apoptosis in A549 cells combined with autophagy inhibitors

In our previous study, we proved that a novel Heat shock protein 90 (HSP90) inhibitor 4-(3-(7-(diethylamino)-2-oxo-2H-chromen-3-yl)-5-phenyl-4,5-dihydro-1H-pyrazol-1-yl) benzoic acid (DPB) could inhibit A549 lung cancer cell growth via inducing apoptosis. However, whether DPB affects autophagy is still unknown. Here, we investigated the effects of DPB on autophagy and the improved anti-cancer activity in A549 lung cancer cells. Aggregation of LC3-II was observed using laser scanning confocal microscopy in GFP-LC3 stably transfected U87 cells. Autophagy and apoptosis-related protein levels were examined by Western blot analysis. It is suggested that treatment with DPB (5-20 μmol/L) induced mTOR-independent autophagy in dose- and time-dependent manners. Pre-treatment A549 cells with autophagy inhibitor 3-methyladenine (3-MA, 5 mmol/L) enhanced DPB-induced apoptosis. And, DPB inhibited A549 cell growth more effectively in combination with autophagy inhibitors 3-MA (5 mmol/L) or 3-benzyl-5-((2-nitrophenoxy) methyl)-dihydrofuran-2(3H)-one (3BDO, 30 μmol/L). These results illustrated that as a potential and promising HSP90 inhibitor, DPB could be utilized in the treatment of cancer combined with the autophagy inhibitor.

Risks of colorectal neoplasms and cardiovascular thromboembolic events after the combined use of selective COX-2 inhibitors and aspirin with 5-year follow-up: a meta-analysis

AIM

We aimed to evaluate the association between selective COX-2 inhibitors (coxibs) and the risk of colorectal neoplasms and vascular events with and without low-dose aspirin.

METHOD

We searched for randomized controlled trials and comparative studies in PubMed, EMBASE and Cochrane Library databases using pertinent key terms. Risk ratios (RRs) were calculated for each study with a fixed- or random-effects model.

RESULTS

Eight clinical studies with 44 566 subjects were eligible. The use of coxib significantly reduced the overall risk of colorectal neoplasms by 21% (RR = 0.79, 95% CI 0.70-0.89; P = 0.000). The chemopreventive effect of coxibs was beneficial in the first year (RR = 0.74, 95% CI 0.58-0.94; P = 0.013), marginal in the third year (RR = 0.79, 95% CI 0.63-1.01; P = 0.059) and counterproductive in the fifth year (RR = 1.65, 95% CI 1.23-2.21; P = 0.001). Compared with the use of aspirin alone, combined use of coxib and aspirin for 3 years increased the risk of a colorectal neoplasm by 80% in the fifth year (RR = 1.80, 95% CI 1.22-2.66; P = 0.003) but decreased by 79% and 30%, respectively, the risks of cardiovascular thromboembolic events (RR = 1.79, 95% CI 1.33-2.41; P = 0.0001) and renal impairment/hypertension (RR = 1.30, 95% CI 1.09-1.54; P = 0.003) caused by coxib use alone.

CONCLUSION

Coxibs may reduce the overall risk of colorectal neoplasms, but the chemopreventive effects are attenuated over time. When participants take low-dose aspirin simultaneously, coxibs may not be useful for chemoprevention of colorectal neoplasm.

Bioactive lipid metabolism in platelet "first responder" and cancer biology

Platelets can serve as "first responders" in cancer and metastasis. This is partly due to bioactive lipid metabolism that drives both platelet and cancer biology. The two primary eicosanoid metabolites that maintain platelet rapid response homeostasis are prostacyclin made by endothelial cells that inhibits platelet function, which is counterbalanced by thromboxane produced by platelets during activation, aggregation, and platelet recruitment. Both of these arachidonic acid metabolites are inherently unstable due to their chemical structure. Tumor cells by contrast predominantly make more chemically stable prostaglandin E₂, which is the primary bioactive lipid associated with inflammation and oncogenesis. Pharmacological, clinical, and epidemiologic studies demonstrate that non-steroidal anti-inflammatory drugs (NSAIDs), which target cyclooxygenases, can help prevent cancer. Much of the molecular and biological impact of these drugs is generally accepted in the field. Cyclooxygenases catalyze the rate-limiting production of substrate used by all synthase molecules, including those that produce prostaglandins along with prostacyclin and thromboxane. Additional eicosanoid metabolites include lipoxygenases, leukotrienes, and resolvins that can also influence platelets, inflammation, and carcinogenesis. Our knowledge base and technology are now progressing toward identifying newer molecular and cellular interactions that are leading to revealing additional targets. This review endeavors to summarize new developments in the field.