HIF-1-mediated metabolic reprogramming reduces ROS levels and facilitates the metastatic colonization of cancers in lungs

Targeting lipid metabolic reprogramming to alleviate diabetic kidney disease: molecular insights and therapeutic strategies

Diabetic kidney disease (DKD) is one of the major complications of diabetes, and its pathological progression is closely associated with lipid metabolic reprogramming. Under diabetic conditions, renal cells undergo significant lipid metabolic abnormalities, including increased lipid uptake, impaired fatty acid oxidation, disrupted cholesterol efflux, and enhanced lipid catabolism, as adaptive responses to metabolic stress. These changes result in the accumulation of lipids such as free fatty acids, diacylglycerol, and ceramides, leading to lipotoxicity that triggers inflammation and fibrosis. Hypoxia in the DKD microenvironment suppresses fatty acid oxidation and promotes lipid synthesis through the HIF-1α pathway, while chronic inflammation exacerbates lipid metabolic disturbances via inflammatory cytokines, inflammasomes, and macrophage polarization. Targeting lipid metabolism represents a promising therapeutic strategy for alleviating DKD; however, further clinical translational studies are warranted to validate the efficacy and safety of these approaches.

Identifying candidate RNA-seq biomarkers for severity discrimination in chemical injuries: A machine learning and molecular dynamics approach

INTRODUCTION

Biomarkers play a crucial role across various fields by providing insights into biological responses to interventions. High-throughput gene expression profiling technologies facilitate the discovery of data-driven biomarkers through extensive datasets. This study focuses on identifying biomarkers in gene expression data related to chemical injuries by mustard gas, covering a spectrum from healthy individuals to severe injuries.

MATERIALS AND METHODS

The study utilized RNA-Seq data comprising 52 expression data samples for 54,583 gene transcripts. These samples were categorized into four classes based on the GOLD classification for chemically injured individuals: Severe (n = 14), Moderate (n = 11), Mild (n = 16), and healthy controls (n = 11). Data preparation involved examining an Excel file created in the R programming environment using MLSeq and devtools packages. Feature selection was performed using Genetic Algorithm and Simulated Annealing, with Random Forest algorithm employed for classification. Ab initio methods ensured computational efficiency and result accuracy, while molecular dynamics simulation acted as a virtual experiment bridging the gap between experimental and theoretical experiences.

RESULTS

A total of 12 models were created, each introducing a list of differentially expressed genes as potential biomarkers. The performance of models varied across group comparisons, with the Genetic Algorithm generally outperforming Simulated Annealing in most cases. For the Severe vs. Moderate group, GA achieved the best performance with an accuracy of 94.38%, recall of 91.64%, and specificity of 97.10%. The results highlight the effectiveness of GA in most group comparisons, while SA performed better in specific cases involving Moderate and Mild groups. These biomarkers were evaluated against the gene expression data to assess their expression changes between different groups of chemically injured individuals. Four genes were selected based on level expression for further investigation: CXCR1, EIF2B2, RAD51, and RXFP2. The expression levels of these genes were analyzed to determine their differential expression between the groups.

CONCLUSION

This study was designed as a computational effort to identify diagnostic biomarkers in basic biological system research. Our findings proposed a list of discriminative biomarkers capable of distinguishing between different groups of chemically injured individuals. The identification of key genes highlights the potential for biomarkers to serve as indicators of chemical injury severity, warranting further investigation to validate their clinical relevance and utility in diagnosis and treatment.

Tumor dormancy and relapse: understanding the molecular mechanisms of cancer recurrence

Cancer recurrence, driven by the phenomenon of tumor dormancy, presents a formidable challenge in oncology. Dormant cancer cells have the ability to evade detection and treatment, leading to relapse. This review emphasizes the urgent need to comprehend tumor dormancy and its implications for cancer recurrence. Despite notable advancements, significant gaps remain in our understanding of the mechanisms underlying dormancy and the lack of reliable biomarkers for predicting relapse. This review provides a comprehensive analysis of the cellular, angiogenic, and immunological aspects of dormancy. It highlights the current therapeutic strategies targeting dormant cells, particularly combination therapies and immunotherapies, which hold promise in preventing relapse. By elucidating these mechanisms and proposing innovative research methodologies, this review aims to deepen our understanding of tumor dormancy, ultimately facilitating the development of more effective strategies for preventing cancer recurrence and improving patient outcomes.

Survival mechanisms of circulating tumor cells and their implications for cancer treatment

Metastasis remains the principal trigger for relapse and mortality across diverse cancer types. Circulating tumor cells (CTCs), which originate from the primary tumor or its metastatic sites, traverse the vascular system, serving as precursors in cancer recurrence and metastasis. Nevertheless, before CTCs can establish themselves in the distant parenchyma, they must overcome significant challenges present within the circulatory system, including hydrodynamic shear stress (HSS), oxidative damage, anoikis, and immune surveillance. Recently, there has been a growing body of compelling evidence suggesting that a specific subset of CTCs can persist within the bloodstream, but the precise mechanisms of their survival remain largely elusive. This review aims to present an outline of the survival challenges encountered by CTCs and to summarize the recent advancements in understanding the underlying survival mechanisms, suggesting their implications for cancer treatment.

Diesel exhaust particles alter mitochondrial bioenergetics and cAMP producing capacity in human bronchial epithelial cells

Introduction: Air pollution from diesel combustion is linked in part to the generation of diesel exhaust particles (DEP). DEP exposure induces various processes, including inflammation and oxidative stress, which ultimately contribute to a decline in lung function. Cyclic AMP (cAMP) signaling is critical for lung homeostasis. The impact of DEP on cAMP signaling is largely unknown. Methods: We exposed human bronchial epithelial (BEAS-2B) cells to DEP for 24-72 h and evaluated mitochondrial bioenergetics, markers of oxidative stress and inflammation and the components of cAMP signaling. Mitochondrial bioenergetics was measured at 72 h to capture the potential and accumulative effects of prolonged DEP exposure on mitochondrial function. Results: DEP profoundly altered mitochondrial morphology and network integrity, reduced both basal and ATP-linked respiration as well as the glycolytic capacity of mitochondria. DEP exposure increased gene expression of oxidative stress and inflammation markers such as interleukin-8 and interleukin-6. DEP significantly affected mRNA levels of exchange protein directly activated by cAMP-1 and -2 (Epac1, Epac2), appeared to increase Epac1 protein, but left phospho-PKA levels unhanged. DEP exposure increased A-kinase anchoring protein 1, β2-adrenoceptor and prostanoid E receptor subtype 4 mRNA levels. Interestingly, DEP decreased mRNA levels of adenylyl cyclase 9 and reduced cAMP levels stimulated by forskolin (AC activator), fenoterol (β2-AR agonist) or PGE2 (EPR agonist). Discussion: Our findings suggest that DEP induces mitochondrial dysfunction, a process accompanied by oxidative stress and inflammation, and broadly dampens cAMP signaling. These epithelial responses may contribute to lung dysfunction induced by air pollution exposure.

SIMULATED AEROMEDICAL EVACUATION EXACERBATES ACUTE LUNG INJURY VIA HYPOXIA-INDUCIBLE FACTOR 1Α-MEDIATED BNIP3/NIX-DEPENDENT MITOPHAGY

ABSTRACT

Background: With the advancement of medicine and the development of technology, the limiting factors of aeromedical evacuation are gradually decreasing, and the scope of indications is expanding. However, the hypobaric and hypoxic environments experienced by critically ill patients in flight can cause lung injury, leading to inflammation and hypoxemia, which remains one of the few limiting factors for air medical evacuation. This study aimed to examine the mechanism of secondary lung injury in rat models of acute lung injury that simulate aeromedical evacuation. Methods: An acute lung injury model was induced in SD rats by the administration of lipopolysaccharide (LPS) followed by exposure to a simulated aeromedical evacuation environment (equivalent to 8,000 feet above sea level) or a normobaric normoxic environment for 4 h. The expression of hypoxia-inducible factor 1α (HIF-1α) was stabilized by pretreatment with dimethyloxalylglycine. The reactive oxygen species levels and the protein expression levels of HIF-1α, Bcl-2-interacting protein 3 (BNIP3), and NIX in lung tissue were measured. Results: Simulated aeromedical evacuation exacerbated pathological damage to lung tissue and increased the release of inflammatory cytokines in serum as well as the reactive oxygen species levels and the protein levels of HIF-1α, BNIP3, and NIX in lung tissue. Pretreatment with dimethyloxalylglycine resulted in increases in the protein expression of HIF-1α, BNIP3, and NIX. Conclusion: Simulated aeromedical evacuation leads to secondary lung injury through mitophagy.

N1-methylnicotinamide impairs gestational glucose tolerance in mice

N1-methylnicotinamide (MNAM), a product of methylation of nicotinamide through nicotinamide N-methyltransferase, displays antidiabetic effects in male rodents. This study aimed to evaluate the ameliorative potential of MNAM on glucose metabolism in a gestational diabetes mellitus (GDM) model. C57BL/6N mice were fed with a high-fat diet (HFD) for 6 weeks before pregnancy and throughout gestation to establish the GDM model. Pregnant mice were treated with 0.3% or 1% MNAM during gestation. MNAM supplementation in CHOW diet and HFD both impaired glucose tolerance at gestational day 14.5 without changes in insulin tolerance. However, MNAM supplementation reduced hepatic lipid accumulation as well as mass and inflammation in visceral adipose tissue. MNAM treatment decreased GLUT4 mRNA and protein expression in skeletal muscle, where NAD+ salvage synthesis and antioxidant defenses were dampened. The NAD+/sirtuin system was enhanced in liver, which subsequently boosted hepatic gluconeogenesis. GLUT1 protein was diminished in placenta by MNAM. In addition, weight of placenta, fetus weight, and litter size were not affected by MNAM treatment. The decreased GLUT4 in skeletal muscle, boosted hepatic gluconeogenesis and dampened GLUT1 in placenta jointly contribute to the impairment of glucose tolerance tests by MNAM. Our data provide evidence for the careful usage of MNAM in treatment of GDM.

Trabectedin and Lurbinectedin Modulate the Interplay between Cells in the Tumour Microenvironment-Progresses in Their Use in Combined Cancer Therapy

Trabectedin (TRB) and Lurbinectedin (LUR) are alkaloid compounds originally isolated from Ecteinascidia turbinata with proven antitumoral activity. Both molecules are structural analogues that differ on the tetrahydroisoquinoline moiety of the C subunit in TRB, which is replaced by a tetrahydro-β-carboline in LUR. TRB is indicated for patients with relapsed ovarian cancer in combination with pegylated liposomal doxorubicin, as well as for advanced soft tissue sarcoma in adults in monotherapy. LUR was approved by the FDA in 2020 to treat metastatic small cell lung cancer. Herein, we systematically summarise the origin and structure of TRB and LUR, as well as the molecular mechanisms that they trigger to induce cell death in tumoral cells and supporting stroma cells of the tumoral microenvironment, and how these compounds regulate immune cell function and fate. Finally, the novel therapeutic venues that are currently under exploration, in combination with a plethora of different immunotherapeutic strategies or specific molecular-targeted inhibitors, are reviewed, with particular emphasis on the usage of immune checkpoint inhibitors, or other bioactive molecules that have shown synergistic effects in terms of tumour regression and ablation. These approaches intend to tackle the complexity of managing cancer patients in the context of precision medicine and the application of tailor-made strategies aiming at the reduction of undesired side effects.

m6A demethylase FTO stabilizes LINK-A to exert oncogenic roles via MCM3-mediated cell-cycle progression and HIF-1α activation

RNA N6-methyladenosine (m6A) modification is implicated in cancer progression, yet its role in regulating long noncoding RNAs during cancer progression remains unclear. Here, we report that the m6A demethylase fat mass and obesity-associated protein (FTO) stabilizes long intergenic noncoding RNA for kinase activation (LINK-A) to promote cell proliferation and chemoresistance in esophageal squamous cell carcinoma (ESCC). Mechanistically, LINK-A promotes the interaction between minichromosome maintenance complex component 3 (MCM3) and cyclin-dependent kinase 1 (CDK1), increasing MCM3 phosphorylation. This phosphorylation facilitates the loading of the MCM complex onto chromatin, which promotes cell-cycle progression and subsequent cell proliferation. Moreover, LINK-A disrupts the interaction between MCM3 and hypoxia-inducible factor 1α (HIF-1α), abrogating MCM3-mediated HIF-1α transcriptional repression and promoting glycolysis and chemoresistance. These results elucidate the mechanism by which FTO-stabilized LINK-A plays oncogenic roles and identify the FTO/LINK-A/MCM3/HIF-1α axis as a promising therapeutic target for ESCC.

Alkaloids as Natural NRF2 Inhibitors: Chemoprevention and Cytotoxic Action in Cancer

Being a controller of cytoprotective actions, inflammation, and mitochondrial function through participating in the regulation of multiple genes in response to stress-inducing endogenous or exogenous stressors, the transcription factor Nuclear Factor Erythroid 2-Related Factor 2 (NRF2) is considered the main cellular defense mechanism to maintain redox balance at cellular and tissue level. While a transient activation of NRF2 protects normal cells under oxidative stress, the hyperactivation of NRF2 in cancer cells may help them to survive and to adapt under oxidative stress. This can be detrimental and related to cancer progression and chemotherapy resistance. Therefore, inhibition of NRF2 activity may be an effective approach for sensitizing cancer cells to anticancer therapy. In this review, we examine alkaloids as NRF2 inhibitors from natural origin, their effects on cancer therapy, and/or as sensitizers of cancer cells to anticancer chemotherapeutics, and their potential clinical applications. Alkaloids, as inhibitor of the NRF2/KEAP1 signaling pathway, can have direct (berberine, evodiamine, and diterpenic aconitine types of alkaloids) or indirect (trigonelline) therapeutic/preventive effects. The network linking alkaloid action with oxidative stress and NRF2 modulation may result in an increased NRF2 synthesis, nuclear translocation, as well in a downstream impact on the synthesis of endogenous antioxidants, effects strongly presumed to be the mechanism of action of alkaloids in inducing cancer cell death or promoting sensitivity of cancer cells to chemotherapeutic agents. In this regard, the identification of additional alkaloids targeting the NRF2 pathway is desirable and the information arising from clinical trials will reveal the potential of these compounds as a promising target for anticancer therapy.

PI3K/AKT/mTOR pathway, hypoxia, and glucose metabolism: Potential targets to overcome radioresistance in small cell lung cancer

Small cell lung cancer (SCLC) is a highly aggressive tumor type for which limited therapeutic progress has been made. Platinum-based chemotherapy with or without thoracic radiotherapy remains the backbone of treatment, but most patients with SCLC acquire therapeutic resistance. Given the need for more effective therapies, better elucidation of the molecular pathogenesis of SCLC is imperative. The phosphoinositide 3-kinase (PI3K)/protein kinase B (AKT)/mammalian target of rapamycin (mTOR) pathway is frequently activated in SCLC and strongly associated with resistance to ionizing radiation in many solid tumors. This pathway is an important regulator of cancer cell glucose metabolism, and its activation probably effects radioresistance by influencing bioenergetic processes in SCLC. Glucose metabolism has three main branches-aerobic glycolysis, oxidative phosphorylation, and the pentose phosphate pathway-involved in radioresistance. The interaction between the PI3K/AKT/mTOR pathway and glucose metabolism is largely mediated by hypoxia-inducible factor 1 (HIF-1) signaling. The PI3K/AKT/mTOR pathway also influences glucose metabolism through other mechanisms to participate in radioresistance, including inhibiting the ubiquitination of rate-limiting enzymes of the pentose phosphate pathway. This review summarizes our understanding of links among the PI3K/AKT/mTOR pathway, hypoxia, and glucose metabolism in SCLC radioresistance and highlights promising research directions to promote cancer cell death and improve the clinical outcome of patients with this devastating disease.

Perfluorodecalin-based oxygenated emulsion as a topical treatment for chemical burn to the eye

Chemical injuries to the eye are emergencies with limited acute treatment options other than prompt irrigation and can cause permanent vision loss. We developed a perfluorodecalin-based supersaturated oxygen emulsion (SSOE) to topically deliver high concentration of oxygen to the eye. SSOE is manufactured in hyperbaric conditions and stored in a ready-to-use canister. Upon dispensation, SSOE rapidly raises partial oxygen pressure 3 times over atmospheric level. SSOE is biocompatible with human corneal cells and safe on mouse eyes in vivo. A single topical application of SSOE to the eye after alkali injury significantly promotes corneal epithelial wound healing, decreases anterior chamber exudation, and reduces optical opacity and cataract formation in mice. SSOE treatment reduces intraocular hypoxia, cell death, leukocyte infiltration, production of inflammatory mediators, and hypoxia-inducible factor 1-alpha signaling, thus hastening recovery of normal tissue integrity during the wound healing process. Here, we show that SSOE is an effective topical therapeutic in the acute treatment of ocular chemical injuries.

An appraisal of the current status of inhibition of glucose transporters as an emerging antineoplastic approach: Promising potential of new pan-GLUT inhibitors

Neoplastic cells displayed altered metabolism with accelerated glycolysis. Therefore, these cells need a mammoth supply of glucose for which they display an upregulated expression of various glucose transporters (GLUT). Thus, novel antineoplastic strategies focus on inhibiting GLUT to intersect the glycolytic lifeline of cancer cells. This review focuses on the current status of various GLUT inhibition scenarios. The GLUT inhibitors belong to both natural and synthetic small inhibitory molecules category. As neoplastic cells express multiple GLUT isoforms, it is necessary to use pan-GLUT inhibitors. Nevertheless, it is also necessary that such pan-GLUT inhibitors exert their action at a low concentration so that normal healthy cells are left unharmed and minimal injury is caused to the other vital organs and systems of the body. Moreover, approaches are also emerging from combining GLUT inhibitors with other chemotherapeutic agents to potentiate the antineoplastic action. A new pan-GLUT inhibitor named glutor, a piperazine-one derivative, has shown a potent antineoplastic action owing to its inhibitory action exerted at nanomolar concentrations. The review discusses the merits and limitations of the existing GLUT inhibitory approach with possible future outcomes.

Antipsychotics impair regulation of glucose metabolism by central glucose

Hypothalamic detection of elevated circulating glucose triggers suppression of endogenous glucose production (EGP) to maintain glucose homeostasis. Antipsychotics alleviate symptoms associated with schizophrenia but also increase the risk for impaired glucose metabolism. In the current study, we examined whether two acutely administered antipsychotics from different drug classes, haloperidol (first generation antipsychotic) and olanzapine (second generation antipsychotic), affect the ability of intracerebroventricular (ICV) glucose infusion approximating postprandial levels to suppress EGP. The experimental protocol consisted of a pancreatic euglycemic clamp, followed by kinomic and RNA-seq analyses of hypothalamic samples to determine changes in serine/threonine kinase activity and gene expression, respectively. Both antipsychotics inhibited ICV glucose-mediated increases in glucose infusion rate during the clamp, a measure of whole-body glucose metabolism. Similarly, olanzapine and haloperidol blocked central glucose-induced suppression of EGP. ICV glucose stimulated the vascular endothelial growth factor (VEGF) pathway, phosphatidylinositol 3-kinase (PI3K) pathway, and kinases capable of activating K_ATP channels in the hypothalamus. These effects were inhibited by both antipsychotics. In conclusion, olanzapine and haloperidol impair central glucose sensing. Although results of hypothalamic analyses in our study do not prove causality, they are novel and provide the basis for a multitude of future studies.

Adaptive and Pathological Outcomes of Radiation Stress-Induced Redox Signaling

Significance: Ionizing radiation can damage cells either directly or through oxidative damage caused by ionization. Although radiation exposure from natural sources is very limited, ionizing radiation in nuclear disaster zones and long spaceflights causes inconspicuous, yet measurable physiological effects in men and animals, whose significance remains poorly known. Understanding the physiological impacts of ionizing radiation has a wide importance due to the increased use of medical imaging and radiotherapy. Recent Advances: Radiation exposure has been traditionally investigated from the perspective of DNA damage and its consequences. However, recent studies from Chernobyl as well as spaceflights have provided interesting insights into oxidative stress-induced metabolic alterations and disturbances in the circadian regulation. Critical Issues: In this review, we discuss the physiological consequences of radiation exposure in the light of oxidative stress signaling. Radiation exposure likely triggers many converging or interconnecting signaling pathways, some of which mimic mitochondrial dysfunction and might explain the observed metabolic changes. Future Directions: Better understanding of the different radiation-induced signaling pathways might help to devise strategies for mitigation of the long-term effects of radiation exposure. The utility of fibroblast growth factor 21 (FGF21) as a radiation exposure biomarker and the use of radiation hormesis as a method to protect astronauts on a prolonged spaceflight, such as a mission to Mars, should be investigated. Antioxid. Redox Signal. 37, 336-348.

Dual-Mode Tumor Imaging Using Probes That Are Responsive to Hypoxia-Induced Pathological Conditions

Hypoxia in solid tumors is associated with poor prognosis, increased aggressiveness, and strong resistance to therapeutics, making accurate monitoring of hypoxia important. Several imaging modalities have been used to study hypoxia, but each modality has inherent limitations. The use of a second modality can compensate for the limitations and validate the results of any single imaging modality. In this review, we describe dual-mode imaging systems for the detection of hypoxia that have been reported since the start of the 21st century. First, we provide a brief overview of the hallmarks of hypoxia used for imaging and the imaging modalities used to detect hypoxia, including optical imaging, ultrasound imaging, photoacoustic imaging, single-photon emission tomography, X-ray computed tomography, positron emission tomography, Cerenkov radiation energy transfer imaging, magnetic resonance imaging, electron paramagnetic resonance imaging, magnetic particle imaging, and surface-enhanced Raman spectroscopy, and mass spectrometric imaging. These overviews are followed by examples of hypoxia-relevant imaging using a mixture of probes for complementary single-mode imaging techniques. Then, we describe dual-mode molecular switches that are responsive in multiple imaging modalities to at least one hypoxia-induced pathological change. Finally, we offer future perspectives toward dual-mode imaging of hypoxia and hypoxia-induced pathophysiological changes in tumor microenvironments.

Oxidative Stress and Cancer Heterogeneity Orchestrate NRF2 Roles Relevant for Therapy Response

Oxidative stress and its end-products, such as 4-hydroxynonenal (HNE), initiate activation of the Nuclear Factor Erythroid 2-Related Factor 2 (NRF2)/Kelch Like ECH Associated Protein 1 (KEAP1) signaling pathway that plays a crucial role in the maintenance of cellular redox homeostasis. However, an involvement of 4-HNE and NRF2 in processes associated with the initiation of cancer, its progression, and response to therapy includes numerous, highly complex events. They occur through interactions between cancer and stromal cells. These events are dependent on many cell-type specific features. They start with the extent of NRF2 binding to its cytoplasmic repressor, KEAP1, and extend to the permissiveness of chromatin for transcription of Antioxidant Response Element (ARE)-containing genes that are NRF2 targets. This review will explore epigenetic molecular mechanisms of NRF2 transcription through the specific molecular anatomy of its promoter. It will explain the role of NRF2 in cancer stem cells, with respect to cancer therapy resistance. Additionally, it also discusses NRF2 involvement at the cross-roads of communication between tumor associated inflammatory and stromal cells, which is also an important factor involved in the response to therapy.

Trophoblast-derived Lactic Acid Orchestrates Decidual Macrophage Differentiation via SRC/LDHA Signaling in Early Pregnancy

Lactic acid (LA) metabolism in the tumor microenvironment contributes to the establishment and maintenance of immune tolerance. This pathway is characterized in tumor associated macrophages. However, the role and pathway of LA metabolism at maternal-fetal interface during early pregnancy, especially in decidual macrophage differentiation, are still unclear. Herein, for the first time, we discovered that LA can trigger either M2 or M1 macrophage polarization via oxidative phosphorylation and glycolysis regulation under normoxia or hypoxia, respectively. Also, LA metabolism played a vital role in decidual macrophages-mediated recurrent pregnancy loss (RPL), through HIF-1α/SRC/LDHA pathway. Moreover, blockade of LA intake with AZD3965 (MCT-1 inhibitor) could rescue pregnancy in an abortion-prone mouse model, suggesting a potential therapeutic target in RPL. Collectively, the present study identifies the previously unknown functions of LA metabolism in the differentiation of decidual macrophages in early normal pregnancy and RPL, and provides a potential therapeutic strategy in RPL by manipulating decidual macrophages' functions through LA metabolic pathway.

The Neglected Liaison: Targeting Cancer Cell Metabolic Reprogramming Modifies the Composition of Non-Malignant Populations of the Tumor Microenvironment

Metabolic reprogramming is a well-known hallmark of cancer, whereby the development of drugs that target cancer cell metabolism is gaining momentum. However, when establishing preclinical studies and clinical trials, it is often neglected that a tumor mass is a complex system in which cancer cells coexist and interact with several types of microenvironment populations, including endothelial cells, fibroblasts and immune cells. We are just starting to understand how such populations are affected by the metabolic changes occurring in a transformed cell and little is known about the impact of metabolism-targeting drugs on the non-malignant tumor components. Here we provide a general overview of the links between cancer cell metabolism and tumor microenvironment (TME), particularly focusing on the emerging literature reporting TME-specific effects of metabolic therapies.

Channeling the Force: Piezo1 Mechanotransduction in Cancer Metastasis

Cancer metastasis is one of the leading causes of death worldwide, motivating research into identifying new methods of preventing cancer metastasis. Recently there has been increasing interest in understanding how cancer cells transduce mechanical forces into biochemical signals, as metastasis is a process that consists of a wide range of physical forces. For instance, the circulatory system through which disseminating cancer cells must transit is an environment characterized by variable fluid shear stress due to blood flow. Cancer cells and other cells can transduce physical stimuli into biochemical responses using the mechanosensitive ion channel Piezo1, which is activated by membrane deformations that occur when cells are exposed to physical forces. When active, Piezo1 opens, allowing for calcium flux into the cell. Calcium, as a ubiquitous second-messenger cation, is associated with many signaling pathways involved in cancer metastasis, such as angiogenesis, cell migration, intravasation, and proliferation. In this review, we discuss the roles of Piezo1 in each stage of cancer metastasis in addition to its roles in immune cell activation and cancer cell death.

Role of RONS and eIFs in Cancer Progression

Various research works have piled up conflicting evidence questioning the effect of oxidative stress in cancer. Reactive oxygen and nitrogen species (RONS) are the reactive radicals and nonradical derivatives of oxygen and nitrogen. RONS can act as a double-edged weapon. On the one hand, RONS can promote cancer initiation through activating certain signal transduction pathways that direct proliferation, survival, and stress resistance. On the other hand, they can mitigate cancer progression via their resultant oxidative stress that causes many cancer cells to die, as some recent studies have proposed that high RONS levels can limit the survival of cancer cells during certain phases of cancer development. Similarly, eukaryotic translation initiation factors are key players in the process of cellular transformation and tumorigenesis. Dysregulation of such translation initiation factors in the form of overexpression, downregulation, or phosphorylation is associated with cancer cell's altering capability of survival, metastasis, and angiogenesis. Nonetheless, eIFs can affect tumor age-related features. Data shows that alternating the eukaryotic translation initiation apparatus can impact many downstream cellular signaling pathways that directly affect cancer development. Hence, researchers have been conducting various experiments towards a new trajectory to find novel therapeutic molecular targets to improve the efficacy of anticancer drugs as well as reduce their side effects, with a special focus on oxidative stress and initiation of translation to harness their effect in cancer development. An increasing body of scientific evidence recently links oxidative stress and translation initiation factors to cancer-related signaling pathways. Therefore, in this review, we present and summarize the recent findings in this field linking certain signaling pathways related to tumorigeneses such as MAPK and PI3K, with either RONS or eIFs.

Targeting Hypoxia-Inducible Factor-1-Mediated Metastasis for Cancer Therapy

Significance: Hypoxia is emerging as a crucial regulator of the tumor microenvironment; it governs the metastatic potential of multiple primary cancers. It is also potentially involved in the regulation of tumorigenesis, tumor metabolism, and proangiogenic activity. Recent Advances: A wealth of clinical data across a wide range of cancer types has revealed strong correlations between hypoxia or the overexpression of hypoxia-inducible transcription factors and the rates of distant metastases and poor prognoses. Hypoxia-inducible factor (HIF)-1α, one of the key regulatory molecules of the HIF-1 signaling pathways, is involved in multiple crucial steps in the metastatic cascade. Critical Issues: Here, we present recent findings on the roles of the HIF-1 complex in tumor metastasis and highlight the potential of HIF-1α as a target for abrogating tumor metastasis. Moreover, we systematically describe the regulatory role of HIF-1 at each step of the metastatic cascade. Finally, we present the most recent advances in potential pharmacological interventions and the development of specific HIF-1 inhibitors for blocking tumor metastasis. Future Directions: Well-designed clinical trials are urgently needed to validate the anti-metastatic activity of HIF-1 inhibitors discovered in preclinical models. Antioxid. Redox Signal. 34, 1484-1497.

Hepatocyte HIF-1 and Intermittent Hypoxia Independently Impact Liver Fibrosis in Murine NAFLD

Obstructive sleep apnea (OSA) is associated with insulin resistance, lipid dysregulation, and hepatic steatosis and fibrosis in nonalcoholic fatty liver disease (NAFLD). We have previously shown that hepatocyte hypoxia inducible factor-1 (HIF-1) mediates the development of liver fibrosis in a mouse model of NAFLD. We hypothesized that intermittent hypoxia (IH) modeling OSA would worsen hepatic steatosis and fibrosis in murine NAFLD, via HIF-1. Mice with hepatocyte-specific deletion of Hif1a (Hif1a^-/-hep) and wild-type (Hif1a^F/F) controls were fed a high trans-fat diet to induce NAFLD with steatohepatitis. Half from each group were exposed to IH, and the other half to intermittent air. Glucose tolerance test was performed prior to sacrifice. Liver collagen and triglycerides were determined. Mitochondrial efficiency was assessed in fresh liver tissue at sacrifice. Hepatic malondialdehyde concentration and pro-inflammatory cytokine levels were assessed, and genes of collagen and fatty acid metabolism were queried. Hif1a^-/-hep mice gained less weight than Hif1a^F/F mice (-2.3 grams, p=0.029). There was also a genotype-independent effect of IH on body weight, with less weight gain in IH (p=0.003). Fasting glucose, HOMA-IR, and glucose tolerance test were all improved in Hif1a^-/-hep mice. Liver collagen was increased in IH (p=0.033), and reduced in Hif1a^-/-hep mice (p<0.001), without any significant exposure/genotype interaction. Liver TNF-α and IL-1β were significantly increased in IH, and decreased in Hif1a^-/-hep. We conclude that HIF-1 signaling worsens the metabolic profile and hastens NAFLD progression, and that IH may worsen liver fibrosis. These effects are plausibly mediated by hepatic inflammatory stress.

Effect of hypoxia factors gene silencing on ROS production and metabolic status of A375 malignant melanoma cells

The innate response of melanocytes to exogenous or endogenous stress stimuli like extreme pH and temperature, metabolite and oxygen deficiency or a high UV dose initiates a cellular stress response. This process activates adaptive processes to minimize the negative impact of the stressor on the pigment cell. Under physiological conditions, a non-cancer cell is directed to apoptosis if the stressor persists. However, malignant melanoma cells will survive persistent stress thanks to distinct "cancerous" signaling pathways (e.g. MEK) and transcription factors that regulate the expression of so-called "survival genes" (e.g. HIF, MITF). In this survival response of cancer cells, MEK pathway directs melanoma cells to deregulate mitochondrial metabolism, to accumulate reduced species (NADH), and to centralize metabolism in the cytosol. The aim of this work was to study the effect of gene silencing in malignant melanoma A375 cells on metabolic processes in cytosol and mitochondria. Gene silencing of HIF-1α, and miR-210 in normoxia and pseudohypoxia, and analysis of its effect on MITF-M, and PDHA1 expression. Detection of cytosolic NADH by Peredox-mCherry Assay. Detection of OCR, and ECAR using Seahorse XF96. Measurement of produced O₂^•- with MitoTracker Red CMXRos. ¹H NMR analysis of metabolites present in cell suspension, and medium. By gene silencing of HIF-1α and miR-210 the expression of PDHA1 was upregulated while that of MITF-M was downregulated, yielding acceleration of mitochondrial respiratory activity and thus elimination of ROS. Hence, we detected a significantly reduced A375 cell viability, an increase in alanine, inositol, nucleotides, and other metabolites that together define apoptosis. Based on the results of measurements of mitochondrial resipiratory activity, ROS production, and changes in the metabolites obtained in cells under the observed conditions, we concluded that silencing of HIF-1α and miR-210 yields apoptosis and, ultimately, apoptotic cell death in A375 melanoma cells.

HIF1 may promote glycolysis in psoriasis vulgaris via upregulation of CD147 and GLUT1

OBJECTIVES

To analyze the expressions and distributions of hypoxia-inducible factor-1α (HIF-1α), CD147, and glucose transporter 1 (GLUT1) in epidermis from psoriasis vulgaris and normal people, and to explore the associations among these proteins and their roles in hypoxic HaCaT cell line.

METHODS

The expression levels of HIF-1α, CD147, and GLUT1 were determined by immunohistochemistry staining in skin biopsies from 48 psoriasis vularis patients and 33 healthy subjects. Cobalt chloride (CoCl2) was added into the culture media of HaCaT cells to mimic hypoxia while RNA interference and transfection technologies were used to explore the association among these proteins by quantitative real-time polymerase chain reaction and Western blotting. Glycolytic capacity was detected by ATP and lactate measurements.

RESULTS

HIF-1α, CD147, and GLUT1 were highly expressed and the glycolytic capacity was increased in lesions of psoriasis vulgaris; HIF-1α upregulated the expression of CD147 and GLUT1, increased the lactate production and decreased the ATP level in CoCl2-treated HaCaT cells, while CD147 and GLUT1 directly or indirectly bound to each other.

CONCLUSIONS

Glycolytic capacity increases in the injured keratinocytes of psoriasis vulgaris, suggesting that HIF-1α, CD147, and GLUT1 are associated with glycolysis, which can be considered as the promising targets for psoriasis therapy.

Nimbolide induces cell death in T lymphoma cells: Implication of altered apoptosis and glucose metabolism

Nimbolide is a tetranortriterpenoid derived from the leaves and flowers of Azadirachta indica (Neem). It exhibits anticancer activity against a variety of cancers by modulating various crucial features, including cell proliferation, apoptosis, and invasion and metastasis. More importantly, the cytotoxic effect of nimbolide has also been observed against T cell lymphoma, but the underlying mechanisms are still unexplored. So far, no study has been conducted to observe the effect of nimbolide on cancer cell metabolism. Therefore, the present investigation was designed to explore the molecular mechanisms of the antitumor potential of nimbolide against T cell lymphoma, a neoplastic disorder of thymic origin. In addition, we also unraveled the anti-glycolytic activity of nimbolide against T lymphoma cells with possible molecular mechanisms. Our results showed the cytotoxic action of nimbolide against three different cell lines of T cell lymphoma, namely Dalton's lymphoma, HuT-78, and J6. Nimbolide-induced apoptosis in T lymphoma cells by altering the level of reactive oxygen species, p53, Bcl2, Bax, and cytochrome c, with subsequent cleavage of caspase 3. Remarkably, nimbolide inhibited the expression of hypoxia-inducible factor-1α, glucose transporter 3, hexokinase II, and pyruvate dehydrogenase kinase 1, which led to the suppression of glycolysis with concomitant activation of oxidative phosphorylation. Hence, the results of the present investigation demonstrate that nimbolide exerts tumoricidal activity against T lymphoma cells via augmentation of apoptosis and reversal of altered cell metabolism. Thus, the present study provides a new insight for the therapeutic utilization of nimbolide against T cell lymphoma.

Reactive Oxygen Species Rewires Metabolic Activity in Acute Myeloid Leukemia

Acute myeloid leukemia (AML) is a heterogeneous disease with poor clinical outcomes. We have previously shown that constitutive activation of NADPH oxidase 2 (NOX2), resulting in over-production of reactive oxygen species (ROS), occurs in over 60% of AML patients. We have also shown that increased ROS production promotes increased glucose uptake and proliferation in AML cells, mediated by changes in carbohydrate metabolism. Given that carbohydrate, lipid, and protein metabolisms are all intricately interconnected, we aimed to examine the effect of cellular ROS levels on these pathways and establish further evidence that ROS rewires metabolism in AML. We carried out metabolomic profiling of AML cell lines in which NOX2-derived ROS production was inhibited and conversely in cells treated with exogenous H2O2. We report significant ROS-specific metabolic alterations in sphingolipid metabolism, fatty acid oxidation, purine metabolism, amino acid homeostasis and glycolysis. These data provide further evidence of ROS directed metabolic changes in AML and the potential for metabolic targeting as novel therapeutic arm to combat this disease.

Regulation of lysyl oxidase expression in THP-1 cell-derived M2-like macrophages

Lysyl oxidase (LOX) is a copper-containing enzyme and its overexpression in tumor tissues promote tumor metastasis through the crosslinking of extracellular matrix. Our previous report demonstrated that LOX expression is significantly increased in human leukemic THP-1 cell-derived M2-like macrophages, and histone modification plays a key role in its induction. However, the rigorous mechanism of LOX regulation remains unclear. In this study, we investigated the role of functional transcription factors, hypoxia-inducible factor 1α (HIF1α), signal transducer and activator of transcription 3 (STAT3) and forkhead box O1 (FOXO1) in LOX regulation in M2-like macrophages. HIF1α expression was significantly increased in M2-like macrophages, and HIF1α inhibitor, TX402, suppressed LOX induction. The significant STAT3 activation was also observed in M2-like macrophages. Additionally, LOX induction was canceled in the presence of STAT3 inhibitor, S3I-201, suggesting that HIF1α and STAT3 pathways play a critical role in LOX induction. On the other hand, our ChIP results clearly indicated that the enrichment of FOXO1 within the lox promoter region was dramatically decreased in M2-like macrophages. In this context, knockdown of FOXO1 further enhanced LOX induction. LOX induction and HIF1α binding to the lox promoter region were suppressed in FOXO1-overexpressed cells, suggesting that the FOXO1 binding to the lox promoter region counteracted HIF1α binding to that region. Overall, the present data suggested that both of HIF1α and STAT3 were required for LOX induction in M2-like macrophages, and loss of FOXO1 within the lox promoter region facilitated HIF1α binding to that region which promoted LOX induction.

Mapping the Metabolic Networks of Tumor Cells and Cancer-Associated Fibroblasts

Metabolism is considered to be the core of all cellular activity. Thus, extensive studies of metabolic processes are ongoing in various fields of biology, including cancer research. Cancer cells are known to adapt their metabolism to sustain high proliferation rates and survive in unfavorable environments with low oxygen and nutrient concentrations. Hence, targeting cancer cell metabolism is a promising therapeutic strategy in cancer research. However, cancers consist not only of genetically altered tumor cells but are interwoven with endothelial cells, immune cells and fibroblasts, which together with the extracellular matrix (ECM) constitute the tumor microenvironment (TME). Cancer-associated fibroblasts (CAFs), which are linked to poor prognosis in different cancer types, are one important component of the TME. CAFs play a significant role in reprogramming the metabolic landscape of tumor cells, but how, and in what manner, this interaction takes place remains rather unclear. This review aims to highlight the metabolic landscape of tumor cells and CAFs, including their recently identified subtypes, in different tumor types. In addition, we discuss various in vitro and in vivo metabolic techniques as well as different in silico computational tools that can be used to identify and characterize CAF-tumor cell interactions. Finally, we provide our view on how mapping the complex metabolic networks of stromal-tumor metabolism will help in finding novel metabolic targets for cancer treatment.

Expression of asporin reprograms cancer cells to acquire resistance to oxidative stress

Asporin (ASPN), a small leucine‐rich proteoglycan expressed predominantly by cancer associated fibroblasts (CAFs), plays a pivotal role in tumor progression. ASPN is also expressed by some cancer cells, but its biological significance is unclear. Here, we investigated the effects of ASPN expression in gastric cancer cells. Overexpression of ASPN in 2 gastric cancer cell lines, HSC‐43 and 44As3, led to increased migration and invasion capacity, accompanied by induction of CD44 expression and activation of Rac1 and MMP9. ASPN expression increased resistance of HSC‐43 cells to oxidative stress by reducing the amount of mitochondrial reactive oxygen species. ASPN induced expression of the transcription factor HIF1α and upregulated lactate dehydrogenase A (LDHA) and PDH‐E1α, suggesting that ASPN reprograms HSC‐43 cells to undergo anaerobic glycolysis and suppresses ROS generation in mitochondria, which has been observed in another cell line HSC‐44PE. By contrast, 44As3 cells expressed high levels of HIF1α in response to oxidant stress and escaped apoptosis regardless of ASPN expression. Examination of xenografts in the gastric wall of ASPN^–/– mice revealed that growth of HSC‐43 tumors with increased micro blood vessel density was significantly accelerated by ASPN; however, ASPN increased the invasion depth of both HSC‐43 and 44As3 tumors. These results suggest that ASPN has 2 distinct effects on cancer cells: HIF1α‐mediated resistance to oxidative stress via reprogramming of glucose metabolism, and activation of CD44‐Rac1 and MMP9 to promote cell migration and invasion. Therefore, ASPN may be a new therapeutic target in tumor fibroblasts and cancer cells in some gastric carcinomas.

HIF-1α inhibits mitochondria-mediated apoptosis and improves the survival of human adipose-derived stem cells in ischemic microenvironments

BACKGROUND

Human adipose mesenchymal stem cells (hADSCs) show poor survival after transplantation, limiting their clinical application. Tissue regeneration resulting from stem cell treatment may be caused by attenuation of hypoxia-inducible factor-1α (HIF-1α). In this study, we constructed hADSCs stably expressing HIF-1α and investigated the potential effects of HIF-1α expression in the ischemic microenvironment on mitochondrial apoptosis and survival of hADSCs, and studied the mechanisms involved.

METHOD

Apoptosis was induced by an ischemic microenvironment in vitro. ADSCs with stable HIF-1α expression were established. Cell survival and apoptosis were observed by CCK-8 assay, western blotting, flow cytometry, and fluorescence staining. ADSCs were subcutaneously transplanted into nude mice in the location where a hypoxia ischemic microenvironment was simulated in vivo. After 1, 3, and 7 d, mitochondrial apoptotic proteins were evaluated by immunohistochemistry and immunofluorescence staining.

RESULTS

Exogenous HIF-1α downregulated mitochondrial reactive oxygen species, cytochrome c, caspase-9, and caspase-3, but inhibited mitochondrial membrane potential depolarization and increased the Bcl-2/bax ratio. HIF-1α prevented apoptosis and promoted vascular endothelial growth factor (VEGF) secretion as demonstrated by enzyme-linked immunosorbent assay (ELISA), terminal deoxyribonucleotidyl transferase-mediated dUTP nick end labeling (TUNEL) staining, and flow cytometry analysis. HIF-1α enhanced the survival of transplanted ADSCs in nude mice.

CONCLUSION

We have shown that through inhibition of the mitochondria-mediated apoptotic pathway and promotion of VEGF secretion in hADSCs in an ischemic microenvironment, HIF-1α may potentially be applied in clinical therapy and as an alternative strategy for improving hADSC therapy.

Free Radicals as a Double-Edged Sword: The Cancer Preventive and Therapeutic Roles of Curcumin

Free radicals, generally composed of reactive oxygen species (ROS) and reactive nitrogen species (RNS), are generated in the body by various endogenous and exogenous systems. The overproduction of free radicals is known to cause several chronic diseases including cancer. However, increased production of free radicals by chemotherapeutic drugs is also associated with apoptosis in cancer cells, indicating the dual nature of free radicals. Among various natural compounds, curcumin manifests as an antioxidant in normal cells that helps in the prevention of carcinogenesis. It also acts as a prooxidant in cancer cells and is associated with inducing apoptosis. Curcumin quenches free radicals, induces antioxidant enzymes (catalase, superoxide dismutase, glutathione peroxidase), and upregulates antioxidative protein markers-Nrf2 and HO-1 that lead to the suppression of cellular oxidative stress. In cancer cells, curcumin aggressively increases ROS that results in DNA damage and subsequently cancer cell death. It also sensitizes drug-resistant cancer cells and increases the anticancer effects of chemotherapeutic drugs. Thus, curcumin shows beneficial effects in prevention, treatment and chemosensitization of cancer cells. In this review, we will discuss the dual role of free radicals as well as the chemopreventive and chemotherapeutic effects of curcumin and its analogues against cancer.

Polymerized human hemoglobin increases the effectiveness of cisplatin-based chemotherapy in non-small cell lung cancer

Cisplatin is a promising therapeutic for the treatment of non-small cell lung cancer (NSCLC). Unfortunately, a significant portion of NSCLC patients relapse due to cisplatin chemoresistance. This chemoresistance is thought to be primarily associated with hypoxia in the tumor microenvironment. Administration of hemoglobin (Hb)-based oxygen (O2) carriers (HBOCs) is a promising strategy to alleviate hypoxia in the tumor, which may make cisplatin more effective. In this study, we administered a high O2 affinity, relaxed state (R-state) polymerized hemoglobin (PolyHb) to three different NSCLC cell lines cultured in vitro and implanted in vivo into healthy mice. The R-state PolyHb administered in this study is unable to deliver O2 unless under severe hypoxia which significantly limits its oxygenation potential. In vitro sensitivity studies indicate that the administration of PolyHb increases the effectiveness of cisplatin under hypoxic conditions. Additional animal studies revealed that co-administration of PolyHb with cisplatin attenuated tumor growth without alleviating hypoxia. Analysis of reactive O2 species production in the presence of hypoxic culture indicates that exogenous ROS production by oxidized PolyHb may the mechanism of chemosensitization. This ROS mechanism, coupled with oxygenation, may be a potential chemosensitizing strategy for use in NSCLC treatment.

Recent Advancements in Liposome-Targeting Strategies for the Treatment of Gliomas: A Systematic Review

Malignant tumors represent some of the most intractable diseases that endanger human health. A glioma is a tumor of the central nervous system that is characterized by severe invasiveness, blurred boundaries between the tumor and surrounding normal tissue, difficult surgical removal, and high recurrence. Moreover, the blood-brain barrier (BBB) and multidrug resistance (MDR) are important factors that contribute to the lack of efficacy of chemotherapy in treating gliomas. A liposome is a biofilm-like drug delivery system with a unique phospholipid bilayer that exhibits high affinities with human tissues/organs (e.g., BBB). After more than five decades of development, classical and engineered liposomes consist of four distinct generations, each with different characteristics: (i) traditional liposomes, (ii) stealth liposomes, (iii) targeting liposomes, and (iv) biomimetic liposomes, which offer a promising approach to promote drugs across the BBB and to reverse MDR. Here, we review the history, preparatory methods, and physicochemical properties of liposomes. Furthermore, we discuss the mechanisms by which liposomes have assisted in the diagnosis and treatment of gliomas, including drug transport across the BBB, inhibition of efflux transporters, reversal of MDR, and induction of immune responses. Finally, we highlight ongoing and future clinical trials and applications toward further developing and testing the efficacies of liposomes in treating gliomas.

Cancer metabolism and mitochondria: Finding novel mechanisms to fight tumours

Mitochondria are dynamic organelles that have essential metabolic activity and are regarded as signalling hubs with biosynthetic, bioenergetics and signalling functions that orchestrate key biological pathways. However, mitochondria can influence all processes linked to oncogenesis, starting from malignant transformation to metastatic dissemination. In this review, we describe how alterations in the mitochondrial metabolic status contribute to the acquisition of typical malignant traits, discussing the most recent discoveries and the many unanswered questions. We also highlight that expanding our understanding of mitochondrial regulation and function mechanisms in the context of cancer cell metabolism could be an important task in biomedical research, thus offering the possibility of targeting mitochondria for the treatment of cancer.

Increasing of malignancy of breast cancer cells after cryopreservation: molecular detection and activation of angiogenesis after CAM-xenotransplantation

Background

Ovarian tissue cryopreservation has a wide range of cancerous indications. Avoiding relapse becomes a specific concern that clinicians frequently encounter. The data about the comparative viability of cancer cells after cryopreservation are limited. This study aimed to evaluate the effect of cryopreservation on breast cancer cells.

Methods

We used in-vitro cultured ZR-75-1 and MDA-MB-231 cell lines. Cell samples of each lineage were distributed into the non-intervened and cryopreserved groups. The cryopreservation procedures comprised programmed slow freezing followed by thawing at 100 °C, 60 s. Biological phenotypes and the related protein markers were compared between the two groups. The EVOS FL Auto 2 Cell Image System was used to monitor cell morphology. Cell proliferation, motility, and penetration were characterized by CCK-8, wound-healing, and transmembrane assay, respectively. The expression of Ki-67, P53, GATA3, E-cadherin, Vimentin, and F-Actin was captured by immunofluorescent staining and western blotting as the proxy measurements of the related properties. The chorioallantoic membrane (CAM) xenotransplantation was conducted to explore angiogenesis induced by cancer cells.

Results

After 5 days in vitro culture, the cell concentration of cryopreserved and non-intervened groups was 15.7 × 10⁴ vs. 14.4 × 10⁴cells/ml, (ZR-75-1, p > 0.05), and 25.1 × 10⁴ vs. 26.6 × 10⁴ cells/ml (MDA-MB-231, p > 0.05). Some cryopreserved ZR-75-1 cells presented spindle shape with filopodia and lamellipodia and dissociated from the cell cluster after cryopreservation. Both cell lines demonstrated increased cell migrating capability and invasion after cryopreservation. The expression of Ki-67 and P53 did not differ between the cryopreserved and non-intervened groups. E-cadherin and GATA3 expression downregulated in the cryopreserved ZR-75-1 cells. Vimentin and F-actin exhibited an upregulated level in cryopreserved ZR-75-1 and MDA-MB-231 cells. The cryopreserved MDA-MB-231 cells induced significant angiogenesis around the grafts on CAM with the vascular density 0.313 ± 0.03 and 0.342 ± 0.04, compared with that of non-intervened cells of 0.238 ± 0.05 and 0.244 ± 0.03, p < 0.0001.

Conclusions

Cryopreservation promotes breast cancer cells in terms of epithelial-mesenchymal transition and angiogenesis induction, thus increasing metastasis risk.

Hypoxia and cancer related pathology

Hypoxic environments occur normally at high altitude, or in underground burrows and in deep sea habitats. They also occur pathologically in human ischemia and in hypoxic solid tumors. Hypoxia in various cancer types and its related molecular mechanisms are associated with a poor clinical outcome. This review will discuss how hypoxia can influence two aspects of tumorigenesis, namely the direct, cell-intrinsic oncogenic effects, as well as the indirect effects on tumor progression mediated by an altered tumor microenvironment. We will also discuss recent progress in identifying the functional roles of hypoxia-related factors (HIFs), along with their regulators and downstream target genes, in cancer stem cells and therapy. Importantly, we propose, using convergent evolution schemes to identify novel biomarkers for both hypoxia adaptation and hypoxic solid tumors as an important strategy in the future.

Reactive Oxygen Species, Metabolic Plasticity, and Drug Resistance in Cancer

The metabolic abnormality observed in tumors is characterized by the dependence of cancer cells on glycolysis for their energy requirements. Cancer cells also exhibit a high level of reactive oxygen species (ROS), largely due to the alteration of cellular bioenergetics. A highly coordinated interplay between tumor energetics and ROS generates a powerful phenotype that provides the tumor cells with proliferative, antiapoptotic, and overall aggressive characteristics. In this review article, we summarize the literature on how ROS impacts energy metabolism by regulating key metabolic enzymes and how metabolic pathways e.g., glycolysis, PPP, and the TCA cycle reciprocally affect the generation and maintenance of ROS homeostasis. Lastly, we discuss how metabolic adaptation in cancer influences the tumor’s response to chemotherapeutic drugs. Though attempts of targeting tumor energetics have shown promising preclinical outcomes, the clinical benefits are yet to be fully achieved. A better understanding of the interaction between metabolic abnormalities and involvement of ROS under the chemo-induced stress will help develop new strategies and personalized approaches to improve the therapeutic efficiency in cancer patients.

HBXIP Regulates Gastric Cancer Glucose Metabolism and Malignancy Through PI3K/AKT and p53 Signaling

Introduction

Hepatitis B X-interacting protein (HBXIP) overexpression is related to the progression of multiple cancers. However, its role in gastric cancer (GC) remains unclear.

Materials and Methods

HBXIP expression was determined in human GC specimens and cell lines by quantitative polymerase chain reaction (qRT-PCR) and Western blot. The effects of HBXIP depletion or ectopic expression on GC proliferation were evaluated in vitro using the cell counting kit-8 (CCK-8), 5-ethynyl-2ʹ-deoxyuridine (EdU) incorporation, colony formation, and cell cycle assays. The in vivo effects were investigated using a mouse xenograft model. Apoptosis was evaluated by flow cytometry (in vitro) and immunohistochemistry (IHC; in vivo). Cell migration and invasion were evaluated in vitro using wound healing, transwell migration, and matrigel invasion assays; and in vivo by quantifying distant metastases from injection of GC cells in the lateral tail vein.

Results

Herein, we reported that HBXIP expression was higher in GC than in normal tissues, and this high expression indicated a poorer prognosis. Gain- and loss-of-function assays showed that HBXIP promoted GC proliferation, migration, and invasion, and inhibited apoptosis. High-performance liquid chromatography (HPLC) quantification of glycolytic metabolites revealed that HBXIP promoted glucose metabolic reprogramming. Investigation of the PI3K/AKT and p53 pathways highlighted their role in this HBXIP-mediated metabolic reprogramming.

Conclusion

Our results indicate that the up-regulation of HBXIP leads to GC progression by positively regulating glucose metabolism. Therefore, HBXIP is a potential target for the treatment of GC.

Environmental factors for establishment of the dormant state in oocytes

Guaranteeing the sustainability of gametogenesis is a fundamental issue for perpetuating the species. In the mammalian ovary, sustainability is accomplished by keeping a number of oocytes “stocked” in the dormant state. Despite the evident importance of this state, the mechanisms underlying the oocyte dormancy are not fully understood, although it is presumed that both intrinsic and extrinsic factors are involved. Here, we review environmental factors involved in the regulation of oocyte dormancy. Consideration of the environmental factors illustrates the nature of the ovarian compartment, in which primordial follicles reside. This should greatly improve our understanding of the mechanisms and also assist in reconstitution of the dormant state in culture. Accumulating knowledge on the dormant state of oocytes will contribute to a wide range of research in fields such as developmental biology, reproductive biology and regenerative medicine.

LncRNA GABPB1-AS1 and GABPB1 regulate oxidative stress during erastin-induced ferroptosis in HepG2 hepatocellular carcinoma cells

Ferroptosis is a non-apoptotic, iron-dependent oxidative form of cell death that is specifically induced by erastin in RAS mutant cancer cells. Ferroptotic cell death is the result of membrane lipid peroxide damage caused by the accumulation of hydroxyl radicals derived from H2O2 by the Fenton reaction. Peroxidases are key cellular antioxidant enzymes that block such damaging processes. Few studies have examined the roles of long non-coding RNAs (lncRNAs) in the regulation of cellular oxidative stress, especially in ferroptosis. Here, we demonstrated that erastin upregulated the lncRNA GABPB1-AS1, which downregulated GABPB1 protein levels by blocking GABPB1 translation, leading to the downregulation of the gene encoding Peroxiredoxin-5 (PRDX5) peroxidase and the eventual suppression of the cellular antioxidant capacity. Such effects critically inhibited the cellular antioxidant capacity and cell viability. Additionally, high expression levels of GABPB1 were correlated with poor prognosis of hepatocellular carcinoma (HCC) Patients, while high GABPB1-AS1 levels in HCC patients correlated with improved overall survival. Collectively, these data demonstrate a mechanistic link between GABPB1 and its antisense lncRNA GABPB1-AS1 in erastin-induced ferroptosis and establish GABPB1 and GABPB1-AS1 as attractive therapeutic targets for HCC.

YTHDF1 links hypoxia adaptation and non-small cell lung cancer progression

Hypoxia occurs naturally at high-altitudes and pathologically in hypoxic solid tumors. Here, we report that genes involved in various human cancers evolved rapidly in Tibetans and six Tibetan domestic mammals compared to reciprocal lowlanders. Furthermore, m6A modified mRNA binding protein YTHDF1, one of evolutionary positively selected genes for high-altitude adaptation is amplified in various cancers, including non-small cell lung cancer (NSCLC). We show that YTHDF1 deficiency inhibits NSCLC cell proliferation and xenograft tumor formation through regulating the translational efficiency of CDK2, CDK4, and cyclin D1, and that YTHDF1 depletion restrains de novo lung adenocarcinomas (ADC) progression. However, we observe that YTHDF1 high expression correlates with better clinical outcome, with its depletion rendering cancerous cells resistant to cisplatin (DDP) treatment. Mechanistic studies identified the Keap1-Nrf2-AKR1C1 axis as the downstream mediator of YTHDF1. Together, these findings highlight the critical role of YTHDF1 in both hypoxia adaptation and pathogenesis of NSCLC.

Self-defense of macrophages against oxidative injury: Fighting for their own survival

Activated macrophages play a central role in both the development and resolution of inflammation. These immune cells need to be functional in harmful conditions with high levels of reactive oxygen and nitrogen species that can damage their basic cell components, which may alter their metabolism. An excessive accumulation of these cell alterations drives macrophages inexorably to cell death, which has been associated to the development of several inflammatory diseases and even with aging in a process termed as "immunosenescence". Macrophages, however, exhibit a prolonged survival in this hostile environment because they equip themselves with a complex network of protective mechanisms. Here we provide an overview of these self-defense mechanisms with special attention being paid to bioactive lipid mediators, NRF2 signaling and metabolic reprogramming.

Molecular and Morphological Evidence of Hepatotoxicity after Silver Nanoparticle Exposure: A Systematic Review, In Silico, and Ultrastructure Investigation

Silver nanoparticles (AgNPs) have been widely used in a variety of applications in innovative development; consequently, people are more exposed to this particle. Growing concern about toxicity from AgNP exposure has attracted greater attention, while questions about nanosilver-responsive genes and consequences for human health remain unanswered. By considering early detection and prevention of nanotoxicology at the genetic level, this study aimed to identify 1) changes in gene expression levels that could be potential indicators for AgNP toxicity and 2) morphological phenotypes correlating to toxicity of HepG2 cells. To detect possible nanosilver-responsive genes in xenogenic targeted organs, a comprehensive systematic literature review of changes in gene expression in HepG2 cells after AgNP exposure and in silico method, connection up- and down-regulation expression analysis of microarrays (CU-DREAM), were performed. In addition, cells were extracted and processed for transmission electron microscopy to examine ultrastructural alterations. From the Gene Expression Omnibus (GEO) Series database, we selected genes that were up- and down-regulated in AgNPs, but not up- and down-regulated in silver ion exposed cells, as nanosilver-responsive genes. HepG2 cells in the AgNP-treated group showed distinct ultrastructural alterations. Our results suggested potential representative gene data after AgNPs exposure provide insight into assessment and prediction of toxicity from nanosilver exposure.

Redox regulation of cell state and fate

The failure in effective cancer treatment is thought to be attributed to a subpopulation of tumor cells with stem cell-like properties. These cancer stem cells (CSCs) are intimately linked to tumor initiation, heterogeneity, maintenance, recurrence and metastasis. Increasing evidence supports the view that a tight redox regulation is crucial for CSC proliferation, tumorigenicity, therapy resistance and metastasis in many cancer types. Since the distinct metabolic and epigenetic states of CSCs may influence ROS levels, and hence their malignancy, ROS modulating agents hold promise in their utility as anti-CSC agents that may improve the durability of current cancer treatments. This review will focus on (i) how ROS levels are regulated for CSCs to elicit their hallmark features; (ii) the link between ROS and metabolic plasticity of CSCs; and (iii) how ROS may interface with epigenetics that would enable CSCs to thrive in a stressful tumor microenvironment and survive therapeutic insults.

Hypoxia induces the dormant state in oocytes through expression of Foxo3

In mammals, most immature oocytes remain dormant in the primordial follicles to ensure the longevity of female reproductive life. A precise understanding of mechanisms underlying the dormancy is important for reproductive biology and medicine. In this study, by comparing mouse oogenesis in vivo and in vitro, the latter of which bypasses the primordial follicle stage, we defined the gene-expression profile representing the dormant state of oocytes. Overexpression of constitutively active FOXO3 partially reproduced the dormant state in vitro. Based on further gene-expression analysis, we found that a hypoxic condition efficiently induced the dormant state in vitro. The effect of hypoxia was severely diminished by disruption of the Foxo3 gene and inhibition of hypoxia-inducible factors. Our findings provide insights into the importance of environmental conditions and their effectors for establishing the dormant state.

Loss of cell-matrix contact increases hypoxia-inducible factor-dependent transcriptional activity in glioma cells

In a variety of malignomas, the acquisition of a mesenchymal phenotype has been linked with anchorage-independent growth and invasiveness. To some extent, glioma cells are able to survive a loss of cell-matrix contact. We here describe that non-adherent culture of glioma cells was accompanied by an increase in hypoxia-inducible factor (HIF)-dependent, but not β-catenin/TCF-induced transcription. Levels of reactive oxygen species decreased in suspension and knockdown of HIF-1α enhanced cell death following detachment. By promoting the adaptation to non-adherent conditions, mechanisms driven by HIF-1α may considerably contribute to the biology and aggressiveness of glioblastoma.

Loss of Epidermal HIF-1α Blocks UVB-Induced Tumorigenesis by Affecting DNA Repair Capacity and Oxidative Stress

HIF-1α is constitutively expressed in mouse and human epidermis. It plays a crucial role in skin physiology, including the response of keratinocytes to UVR. However, little information is available about its role in photocarcinogenesis. Using a multistage model of UVB radiation-induced skin cancer, we show that the knockout of Hif-1α in the epidermis prevents tumorigenesis but at the same time triggers the formation of hyperkeratotic plaques. Our results indicate that the absence of oncogenic transformation in Hif-1α-ablated mice is related to increased DNA repair in keratinocytes, whereas the formation of hyperkeratotic plaques is caused by an increase in the levels of reactive oxygen species. Indeed, impairing the DNA repair machinery by ablating xeroderma pigmentosum C restored the UVB-induced neoplastic transformation of Hif-1α-ablated keratinocytes, whereas the development of hyperkeratotic plaques was blocked by chronic antioxidant treatment. We conclude that HIF-1α plays a procarcinogenic role in UVB-induced tumorigenesis.

Development of Inflammatory Hypoxia and Prevalence of Glycolytic Metabolism in Progressing Herpes Stromal Keratitis Lesions

Chronic inflammation in tissues often causes the development of hypoxia. Herpes stromal keratitis (HSK) is a corneal chronic inflammatory condition that develops in response to recurrent HSV-1 infection. In this study, we investigated the development of hypoxia, the expression of hypoxia-associated glycolytic genes in HSV-1 infected corneas, and the outcome of blocking hypoxia-inducible factor (HIF) dimerization on the severity of HSK. Our results showed the development of hypoxia, an elevated expression of hypoxia-associated glycolytic genes, and an increased level of lactate in corneas with progressing HSK lesions. The magnitude of hypoxia correlated with the extent of neutrophils infiltrating the infected corneas, and the depletion of neutrophils reduced the development of hypoxia in infected corneas. Additionally, in progressing HSK lesions, nuclear localization of HIF-2α protein was detected in corneal epithelial cells, whereas HIF-1α protein stabilization was observed in infiltrating immune cells. Administration of acriflavine drug to HSV-1-infected mice inhibited nuclear accumulation of HIF-1α and HIF-2α protein in immune cell types and epithelial cells, respectively, in infected corneas. As a result, a decreased influx of CD4 T cells and nongranulocytic myeloid cells, but an increased influx of neutrophils, was noted in developing HSK lesions. Interestingly, acriflavine treatment given during the clinical disease period decreased neovascularization but increased the opacity in HSV-1-infected corneas. Taken together, the results of our study lay the foundation to dissect the role of inflammatory hypoxia and hypoxia-associated genes in the pathogenesis of HSK.