Hypoxia-induced VEGF enhances tumor survivability via suppression of serum deprivation-induced apoptosis

Hyperoxic-hypoxic Paradox: Breast Cancer Microenvironment and an Innovative Treatment Strategy

A small therapeutic range of oxygen is required for effective metabolism. As a result, hypoxia (low oxygen concentration) is one of the most potent inducers of gene expression, metabolic alterations, and regenerative processes, such as angiogenesis, stem cell proliferation, migration, and differentiation. The cellular response is controlled by sensing the increased oxygen levels (hyperoxia) or hypoxia via specific chemoreceptor cells. Surprisingly, changes in free oxygen concentration instead of absolute oxygen levels may be regarded as a deficiency of oxygen at the cellular level. Recurrent intermittent hyperoxia may trigger many mediators of cellular pathways typically generated during hypoxia. The dilemma of hyperoxic-hypoxic conditions is known as the hyperoxic-hypoxic paradox. According to the latest data, the hypoxic microenvironment, crucial during cancer formation, has been demonstrated to play a key role in regulating breast cancer growth and metastasis. Hypoxic circumstances cause breast cancer cells to respond in a variety of ways. Transcription factors are identified as hypoxia-inducible factors (HIFs) that have been suggested to be a factor in the pathobiology of breast cancer and a possible therapeutic target, driving the cellular response to hypoxia. Breast cancer has a dismal prognosis due to a high level of resistance to practically all well-known cancer management that has been related to hypoxia-based interactions between tumor cells and the stromal milieu. We attempt to review the enigma by exploring the starring roles of HIFs in breast cancer, the HIF paradox, and the hyperoxic-hypoxic enigma.

Targeting the RAS/RAF/MAPK pathway for cancer therapy: from mechanism to clinical studies

Metastatic dissemination of solid tumors, a leading cause of cancer-related mortality, underscores the urgent need for enhanced insights into the molecular and cellular mechanisms underlying metastasis, chemoresistance, and the mechanistic backgrounds of individuals whose cancers are prone to migration. The most prevalent signaling cascade governed by multi-kinase inhibitors is the mitogen-activated protein kinase (MAPK) pathway, encompassing the RAS-RAF-MAPK kinase (MEK)-extracellular signal-related kinase (ERK) pathway. RAF kinase is a primary mediator of the MAPK pathway, responsible for the sequential activation of downstream targets, such as MEK and the transcription factor ERK, which control numerous cellular and physiological processes, including organism development, cell cycle control, cell proliferation and differentiation, cell survival, and death. Defects in this signaling cascade are associated with diseases such as cancer. RAF inhibitors (RAFi) combined with MEK blockers represent an FDA-approved therapeutic strategy for numerous RAF-mutant cancers, including melanoma, non-small cell lung carcinoma, and thyroid cancer. However, the development of therapy resistance by cancer cells remains an important barrier. Autophagy, an intracellular lysosome-dependent catabolic recycling process, plays a critical role in the development of RAFi resistance in cancer. Thus, targeting RAF and autophagy could be novel treatment strategies for RAF-mutant cancers. In this review, we delve deeper into the mechanistic insights surrounding RAF kinase signaling in tumorigenesis and RAFi-resistance. Furthermore, we explore and discuss the ongoing development of next-generation RAF inhibitors with enhanced therapeutic profiles. Additionally, this review sheds light on the functional interplay between RAF-targeted therapies and autophagy in cancer.

Optimized strategies of ROS-based nanodynamic therapies for tumor theranostics

Reactive oxygen species (ROS) play a crucial role in regulating the metabolism of tumor growth, metastasis, death and other biological processes. ROS-based nanodynamic therapies (NDTs) are becoming attractive due to non-invasive, low side effects and tumor-specific advantages. NDTs have rapidly developed into numerous branches, such as photodynamic therapy, chemodynamic therapy, sonodynamic therapy and so on. However, the complexity of the tumor microenvironment and the limitations of existing sensitizers have greatly restricted the therapeutic effects of NDTs, which heavily rely on ROS levels. To address the limitations of NDTs, various strategies have been developed to increase ROS yield, which is an urgent aspect for the positive development of NDTs. In this review, the nanodynamic potentiation strategies in terms of unique properties and universalities of NDTs are comprehensively outlined. We mainly summarize the current dilemmas faced by each NDT and the respective solutions. Meanwhile, the NDTs universalities-based potentiation strategies and NDTs-based combined treatments are elaborated. Finally, we conclude with a discussion of the key issues and challenges faced in the development and clinical transformation of NDTs.

Adipose-derived mesenchymal stem cells cultured in serum-free medium attenuate acute contrast-induced nephropathy by exerting anti-apoptotic effects

BACKGROUND

Contrast-induced nephropathy (CIN) is a major clinical problem associated with acute kidney injury during hospitalization. However, effective treatments for CIN are currently lacking. Mesenchymal stem cells (MSCs) have protective effects against kidney injury by suppressing inflammation and fibrosis. We previously showed that MSCs cultured in serum-free medium (SF-MSCs) enhance their anti-inflammatory and anti-fibrotic effects. However, whether SF-MSCs potentiate their anti-apoptotic effects is unknown. Here, we investigated the effects of SF-MSCs on a CIN mouse model.

METHODS

To create CIN model mice, we removed right kidney at first. One week later, the left renal artery was clamped for 30 min to cause ischemia-reperfusion injury, and mice were injected with iohexol. Then the kidney received 10 Gy of irradiation, and MSCs or SF-MSCs were injected immediately. At 24 h post-injection, mice were sacrificed, and their blood and kidneys were collected to evaluate renal function, DNA damage, and apoptosis. In addition, apoptosis was induced in HEK-293 cells by irradiation and cells were treated with conditioned medium from MSCs or SF-MSCs.

RESULTS

Treatment of CIN model mice with SF-MSCs markedly improved renal function compared with MSCs treatment. Cleaved caspase-3 levels and TUNEL-positive cell numbers were strongly suppressed in CIN model mice treated with SF-MSCs compared with the findings in those treated with MSCs. γH2AX levels, a chromosome damage marker, were reduced by MSCs and further reduced by SF-MSCs. In addition, cleaved caspase-3 in irradiated HEK-293 cells was more strongly suppressed by conditioned medium from SF-MSCs than by that from MSCs. Secretion of epidermal growth factor (EGF) was enhanced by culturing MSCs in serum-free medium. Knockdown of EGF by siRNA attenuated the inhibitory effects of SF-MSCs on CIN-induced renal dysfunction and tubular apoptosis.

CONCLUSIONS

These findings strongly suggest that SF-MSCs improve CIN in model mice by exerting anti-apoptotic effects in a paracrine manner. Thus, SF-MSCs represent a potential novel therapy for CIN.

Engineering chimeric antigen receptor T cells for solid tumour therapy

Cell-based immunotherapy, for example, chimeric antigen receptor T (CAR-T) cell immunotherapy, has revolutionized cancer treatment, particularly for blood cancers. However, factors such as insufficient T cell tracking, tumour heterogeneity, inhibitory tumour microenvironment (TME) and T cell exhaustion limit the broad application of CAR-based immunotherapy for solid tumours. In particular, the TME is a complex and evolving entity, which is composed of cells of different types (e.g., cancer cells, immune cells and stromal cells), vasculature, soluble factors and extracellular matrix (ECM), with each component playing a critical role in CAR-T immunotherapy. Thus, developing approaches to mitigate the inhibitory TME factors is critical for future success in applying CAR-T cells for solid tumour treatment. Accordingly, understanding the bilateral interaction of CAR-T cells with the TME is in pressing need to pave the way for more efficient therapeutics. In the following review, we will discuss TME-associated aspects with an emphasis on T cell trafficking, ECM barriers, abnormal vasculature, solid tumour heterogenicity and immune suppressive microenvironment. We will then summarize current engineering strategies to overcome the challenges posed by the TME-associated factors. Lastly, the future directions for engineering efficient CAR-T cells for solid tumour therapy will be discussed.

HOXA10 enhances cell proliferation and suppresses apoptosis in esophageal cancer via activating p38/ERK signaling pathway

Esophageal cancer (EC) is an extremely aggressive malignant tumor. Homeobox A10 (HOXA10) is highly expressed and plays an important role in a variety of tumors. However, the function of HOXA10 in EC remains unclear. In this study, HOXA10 was observed to highly express in EC tissues and cells. Interestingly, the CCK-8 assay, flow cytometry, and colony formation assay confirmed that overexpression of HOXA10 promoted proliferation and suppressed cell apoptosis in EC cells. More importantly, the western blot assay indicated that the phosphorylation levels of ERK and p38 were elevated in EC cells overexpressed HOXA10, indicating that overexpression of HOXA10 activated p38/ERK signaling pathway in EC cells. These findings concluded that HOXA10 aggravated EC progression via activating p38/ERK signaling pathway, providing a potential therapeutic target for EC.

Life at the periphery: what makes CHO cells survival talents

Abstract

The production of biopharmaceuticals relies on robust cell systems that can produce recombinant proteins at high levels and grow and survive in the stressful bioprocess environment. Chinese hamster ovary cells (CHO) as the main production hosts offer a variety of advantages including robust growth and survival in a bioprocess environment. Cell surface proteins are of special interest for the understanding of how CHO cells react to their environment while maintaining growth and survival phenotypes, since they enable cellular reactions to external stimuli and potentially initiate signaling pathways. To provide deeper insight into functions of this special cell surface sub-proteome, pathway enrichment analysis of the determined CHO surfaceome was conducted. Enrichment of growth/ survival-pathways such as the phosphoinositide-3-kinase (PI3K)–protein kinase B (AKT), mitogen-activated protein kinase (MAPK), Janus kinase/signal transducers and activators of transcription (JAK-STAT), and RAP1 pathways were observed, offering novel insights into how cell surface receptors and ligand-mediated signaling enable the cells to grow and survive in a bioprocess environment. When supplementing surfaceome data with RNA expression data, several growth/survival receptors were shown to be co-expressed with their respective ligands and thus suggesting self-induction mechanisms, while other receptors or ligands were not detectable. As data about the presence of surface receptors and their associated expressed ligands may serve as base for future studies, further pathway characterization will enable the implementation of optimization strategies to further enhance cellular growth and survival behavior.

Key points

• PI3K/AKT, MAPK, JAK-STAT, and RAP1 pathway receptors are enriched on the CHO cell surface and downstream pathways present on mRNA level.

• Detected pathways indicate strong CHO survival and growth phenotypes.

• Potential self-induction of surface receptors and respective ligands.

Graphical abstract

Supplementary Information

The online version contains supplementary material available at 10.1007/s00253-022-12123-6.

MCRS1 Expression Regulates Tumor Activity and Affects Survival Probability of Patients with Gastric Cancer

Gastric cancer is the fifth most common cancer worldwide and the third most common cause of cancer-related deaths. Surgery remains the first-choice treatment. Chemotherapy is considered in the middle and advanced stages, but has limited success. Microspherule protein 1 (MCRS1, also known as MSP58) is a protein originally identified in the nucleus and cytoplasm that is involved in the cell cycle. High expression of MCRS1 increases tumor growth, invasiveness, and metastasis. The mechanistic relationships between MCSR1 and proliferation, apoptosis, angiogenesis, and epithelial–mesenchymal transition (EMT) remain to be elucidated. We clarified these relationships using immunostaining of tumor tissues and normal tissues from patients with gastric cancer. High MCRS1 expression in gastric cancer positively correlated with Ki-67, Caspase3, CD31, Fibronectin, pAKT, and pAMPK. The hazard ratio of high MCRS1 expression was 2.44 times that of low MCRS1 expression, negatively impacting patient survival.

Hypoxia represses early responses of prostate and renal cancer cells to YM155 independent of HIF-1α and HIF-2α

The imidazolium compound Sepantronium Bromide (YM155) successfully promotes tumor regression in various pre-clinical models but has shown modest responses in human clinical trials. We provide evidence to support that the hypoxic milieu of tumors may limit the clinical usefulness of YM155. Hypoxia (1% O2) strongly (>16-fold) represses the cytotoxic activity of YM155 on prostate and renal cancer cells in vitro. Hypoxia also represses all early signaling responses associated with YM155, including activation of AMPK and retinoblastoma protein (Rb), inactivation of the mechanistic target of rapamycin complex 1 (mTORC1), inhibition of phospho-ribosomal protein S6 (rS6), and suppression of the expression of Cyclin Ds, Mcl-1 and Survivin. Cells pre-incubated with hypoxia for 24 ​h are desensitized to YM155 even when they are treated with YM155 under atmospheric oxygen conditions, supporting that cells at least temporarily retain hypoxia-induced resistance to YM155. We tested the role of hypoxia-inducible factor (HIF)-1α and HIF-2α in the hypoxia-induced resistance to YM155 by comparing responses of YM155 in VHL-proficient versus VHL-deficient RCC4 and 786-O renal cancer cells and silencing HIF expression in PC-3 prostate cancer cells. Those studies suggested that hypoxia-induced resistance to YM155 occurs independent of HIF-1α and HIF-2α. Moreover, the hypoxia mimetics deferoxamine and dimethyloxalylglycine, which robustly induce HIF-1α levels in PC-3 ​cells under atmospheric oxygen, did not diminish their early cellular responses to YM155. Collectively, our data support that hypoxia induces resistance of cells to YM155 through a HIF-1α and HIF-2α-independent mechanism. We hypothesize that a hypothetical hypoxia-inducer factor (HIF-X) represses early signaling responses to YM155.

Vascular Microenvironment, Tumor Immunity and Immunotherapy

Immunotherapy holds great promise for treating cancer. Nonetheless, T cell-based immunotherapy of solid tumors has remained challenging, largely due to the lack of universal tumor-specific antigens and an immunosuppressive tumor microenvironment (TME) that inhibits lymphocyte infiltration and activation. Aberrant vascularity characterizes malignant solid tumors, which fuels the formation of an immune-hostile microenvironment and induces tumor resistance to immunotherapy, emerging as a crucial target for adjuvant treatment in cancer immunotherapy. In this review, we discuss the molecular and cellular basis of vascular microenvironment-mediated tumor evasion of immune responses and resistance to immunotherapy, with a focus on vessel abnormality, dysfunctional adhesion, immunosuppressive niche, and microenvironmental stress in tumor vasculature. We provide an overview of opportunities and challenges related to these mechanisms. We also propose genetic programming of tumor endothelial cells as an alternative approach to recondition the vascular microenvironment and to overcome tumor resistance to immunotherapy.

Experimental Study on the Correlation between miRNA-373 and HIF-1α, MMP-9, and VEGF in the Development of HIE

INTRODUCTION

Microribonucleic acids (miRNAs) have short (approximately 18 to 25) nucleotides and are evolutionarily conserved and endogenously expressed RNAs belonging to a family of noncoding RNA molecules. miRNA-373 regulates cell proliferation, migration, apoptosis, invasion, and repairing damaged DNA after hypoxia stress. Neonatal hypoxic-ischemic encephalopathy (HIE) refers to perinatal asphyxia caused by partial or complete hypoxia, reduced or suspended cerebral blood flow, and fetal or neonatal brain damage. We aim to investigate the relationship between miRNA-373 and HIF-1α, between miRNA-373 MMP-9, and between miRNA-373 VEGF in the occurrence and development of HIE.

METHODS

Human (children) samples were divided into four groups (n = 15 in each group) according to HIE severity. The patient group was divided into middle, moderate, and severe HIE groups. The control group included healthy children or children with nonneurological diseases. The expressions of miRNA-373, HIF-1α, MMP-9, and VEGF were assayed in the serum samples.

RESULTS

Our study showed a strong relationship between miRNA-373 and HIF-1α, between miRNA-373 and MMP-9, and between miRNA-373 and VEGF. The expression levels of miRNA-373, HIF-1α, MMP-9, and VEGF in the HIE groups were much higher than those of the control group.

CONCLUSION

The increased change in miRNA-373 expression has a certain diagnostic significance on neonatal HIE. In the occurrence and development of HIE, miRNA-373 is positively correlated with HIF-1α, MMP-9, and VEGF.

Hypoxia in Breast Cancer-Scientific Translation to Therapeutic and Diagnostic Clinical Applications

Breast cancer has been the leading cause of female cancer deaths for decades. Intratumoral hypoxia, mainly caused by structural and functional abnormalities in microvasculature, is often associated with a more aggressive phenotype, increased risk of metastasis and resistance to anti-malignancy treatments. The response of cancer cells to hypoxia is ascribed to hypoxia-inducible factors (HIFs) that activate the transcription of a large battery of genes encoding proteins promoting primary tumor vascularization and growth, stromal cell recruitment, extracellular matrix remodeling, cell motility, local tissue invasion, metastasis, and maintenance of the cancer stem cell properties. In this review, we summarized the role of hypoxia specifically in breast cancer, discuss the prognostic and predictive value of hypoxia factors, potential links of hypoxia and endocrine resistance, cancer hypoxia measurements, further involved mechanisms, clinical application of hypoxia-related treatments and open questions.

Vitamin E protects against gabapentin-induced chronic hepatic and renal damage associated with the inhibition of apoptosis and tissue injury in rats

AIMS

This study aimed to investigate the potential protective effects of vitamin E against gabapentin-induced chronic liver and kidney injury associated with the inhibition of biomarkers of apoptosis and tissue injury.

MATERIALS AND METHODS

Four groups of adult male rats were included; control, gabapentin (100 mg/kg/day), Vitamin E (80 mg/kg/day), and a combination of gabapentin and Vitamin E for 90 days. Serum levels of AST, ALT, LDH, ALP, urea, and creatinine were measured in addition to malondialdehyde (MDA), and reduced glutathione (GSH) tissue levels. P53 gene expression, histological, and immunohistochemical examinations were performed in liver and kidney tissue samples.

KEY FINDINGS

Gabapentin increased AST, ALT, LDH, ALP, urea, creatinine, MDA, and p53 gene expression and it reduced GSH. Moreover, gabapentin administration caused structural changes in the hepatic and renal architecture with a weak Periodic acid-Schiff (PAS) reaction that reflects glycogen deposition in the liver and kidney and a positive immunoreaction for BCL2-associated X protein (BAX) that reflects activated apoptosis. Vitamin E significantly (p<0.05) reversed the biochemical alterations associated with chronic gabapentin administration and improved the histopathological picture of hepatic and renal tissue with a partial inhibition of BAX.

SIGNIFICANCE

Chronic administration of gabapentin causes hepatic and renal impairments, which is ameliorated by Vitamin E; possibly due to the inhibition of biomarkers of apoptosis and tissue injury.

Mitochondrial manganese superoxide dismutase knock-down increases oxidative stress and caspase-3 activity in the white shrimp Litopenaeus vannamei exposed to high temperature, hypoxia, and reoxygenation

Shrimp are increasingly exposed to warmer temperatures and lower oxygen concentrations in their habitat due to climate change. These conditions may lead to oxidative stress and apoptosis. We studied the effects of high temperature, hypoxia, reoxygenation, and the combination of these factors on lipid peroxidation, protein carbonylation, and caspase-3 activity in gills of white shrimp Litopenaeus vannamei. Silencing of mitochondrial manganese superoxide dismutase (mMnSOD) was used to determine the role of this enzyme in response to the abiotic stressors described above, to avoid oxidative damage and apoptosis. In addition, mMnSOD gene expression and mitochondrial SOD activity were evaluated to determine the efficiency of silencing this enzyme. The results showed that there was no effect of the abiotic stress conditions on the thiobarbituric acid reactive substances (TBARS), but protein carbonylation increased in all the oxidative stress treatments and caspase-3 activity decreased in hypoxia at 28 °C. On the other hand, mMnSOD-silenced shrimp experienced higher oxidative stress, since TBARS, carbonylated proteins and caspase-3 activity increased in some silenced treatments. Unexpectedly, mitochondrial SOD activity increased in some of the silenced treatments as well. Altogether, these results suggest that mMnSOD has a key role in shrimp for the prevention of oxidative damage development and induction of apoptosis in response to hypoxia, reoxygenation, high temperature, and their interactions, as conditions derived from climate change.

Prospects of tangeretin as a modulator of cancer targets/pathways

To date, cancer is the second leading cause of death worldwide after cardiac arrest. A large number of synthetic drugs are available for the treatment of different types of cancer; however, a major problem associated with these drugs is its toxicity towards the normal cells. To overcome these problems, researchers explore plants derived phytochemicals because of their pleiotropic action and least toxicity towards the normal cells. Tangeretin is a polymethoxylated flavone found extensively in citrus fruits and has shown potent anti-cancer activity in different types of cancer cells. Hence, this review examines the anti-cancer activity of tangeretin via different molecular targets/pathways. Tangeretin induces apoptosis via intrinsic as well as extrinsic pathways and arrest the cell cycle. It also suppresses cell proliferation by modulating PI3K/AKT/mTOR, Notch, and MAPK signalling pathways. Besides, it induces autophagic cell death, suppresses migration, invasion, and angiogenesis. Further, the role of tangeretin in multi-drug resistance and combination therapy, different biological sources of tangeretin, its derivatives, and pharmacokinetics profile and toxicity studies are also discussed. Towards the end, the challenges associated with tangeretin usage as potential anti-cancer phytochemicals have also been discussed. Tangeretin, like a pandora's box, needs to be explored further, and more research is warranted to improve its usefulness for better human health.

Bone Marrow Stromal Cells-Induced Drug Resistance in Multiple Myeloma

Multiple myeloma is a B-cell lineage cancer in which neoplastic plasma cells expand in the bone marrow and pathophysiological interactions with components of microenvironment influence many biological aspects of the malignant phenotype, including apoptosis, survival, proliferation, and invasion. Despite the therapeutic progress achieved in the last two decades with the introduction of a more effective and safe new class of drugs (i.e., immunomodulators, proteasome inhibitors, monoclonal antibodies), there is improvement in patient survival, and multiple myeloma (MM) remains a non-curable disease. The bone marrow microenvironment is a complex structure composed of cells, extracellular matrix (ECM) proteins, and cytokines, in which tumor plasma cells home and expand. The role of the bone marrow (BM) microenvironment is fundamental during MM disease progression because modification induced by tumor plasma cells is crucial for composing a "permissive" environment that supports MM plasma cells proliferation, migration, survival, and drug resistance. The "activated phenotype" of the microenvironment of multiple myeloma is functional to plasma cell proliferation and spreading and to plasma cell drug resistance. Plasma cell drug resistance induced by bone marrow stromal cells is mediated by stress-managing pathways, autophagy, transcriptional rewiring, and non-coding RNAs dysregulation. These processes represent novel targets for the ever-increasing anti-MM therapeutic armamentarium.

ERK/MAPK signalling pathway and tumorigenesis

Mitogen-activated protein kinase (MAPK) cascades are key signalling pathways that regulate a wide variety of cellular processes, including proliferation, differentiation, apoptosis and stress responses. The MAPK pathway includes three main kinases, MAPK kinase kinase, MAPK kinase and MAPK, which activate and phosphorylate downstream proteins. The extracellular signal-regulated kinases ERK1 and ERK2 are evolutionarily conserved, ubiquitous serine-threonine kinases that regulate cellular signalling under both normal and pathological conditions. ERK expression is critical for development and their hyperactivation plays a major role in cancer development and progression. The Ras/Raf/MAPK (MEK)/ERK pathway is the most important signalling cascade among all MAPK signal transduction pathways, and plays a crucial role in the survival and development of tumour cells. The present review discusses recent studies on Ras and ERK pathway members. With respect to processes downstream of ERK activation, the role of ERK in tumour proliferation, invasion and metastasis is highlighted, and the role of the ERK/MAPK signalling pathway in tumour extracellular matrix degradation and tumour angiogenesis is emphasised.

Hypoxia in the Initiation and Progression of Neuroblastoma Tumours

Neuroblastoma is the most frequent extracranial solid tumour in children, causing 10% of all paediatric oncology deaths. It arises in the embryonic neural crest due to an uncontrolled behaviour of sympathetic nervous system progenitors, giving rise to heterogeneous tumours. Low local or systemic tissue oxygen concentration has emerged as a cellular stimulus with important consequences for tumour initiation, evolution and progression. In neuroblastoma, several evidences point towards a role of hypoxia in tumour initiation during development, tumour cell differentiation, survival and metastatic spreading. However, the heterogeneous nature of the disease, its developmental origin and the lack of suitable experimental models have complicated a clear understanding of the effect of hypoxia in neuroblastoma tumour progression and the molecular mechanisms implicated. In this review, we have compiled available evidences to try to shed light onto this important field. In particular, we explore the effect of hypoxia in neuroblastoma cell transformation and differentiation. We also discuss the experimental models available and the emerging alternatives to study this problem, and we present hypoxia-related therapeutic avenues being explored in the field.

Berberine ameliorates CCl4‑induced liver injury in rats through regulation of the Nrf2‑Keap1‑ARE and p53 signaling pathways

Berberine (BBR) is an isoquinoline alkaloid, reported to have multiple pharmacological functions. However, its effects against CCl4‑induced oxidative damage remain poorly studied. Therefore, the present study investigated the protective action of BBR, and its antioxidant mechanisms, against CCl4‑induced liver injury in rats. A total of 48 rats were randomly arranged into six groups: Control; model; positive control (PC); BBR low‑dose (BL); BBR middle‑dose (BM); and BBR high‑dose (BH). The BL, BM and BH animals received BBR (5, 10 and 15 mg/kg by weight, respectively) orally for 7 consecutive days. Rats in the PC group were given silymarin (150 mg/kg), and the control and model groups were administered distilled water orally. At the end of the experiment, blood samples and livers were collected. To measure the liver biochemical indices, the reactive oxygen species (ROS) generation and the expression levels of related genes and protein, the following methods were used: An automatic biochemical analyzer; flow cytometry; spectrophotometry; reverse transcription‑quantitative PCR; western blotting; and hematoxylin and eosin staining. The results revealed that BBR significantly decreased the serum levels of alanine transaminase, aspartate transaminase and alkaline phosphatase, and increased those of glutathione and superoxide dismutase, but decreased malondialdehyde activity in hepatic tissue, and significantly decreased the reactive oxygen species level in hepatocytes. In hepatic tissue, the expressions of nuclear factor erythroid 2‑related factor 2 (Nrf2), kelch‑like ECH‑associated protein 1 (Keap-1), NAD(P)H quinone dehydrogenase 1 (NQO-1), heme oxygenase 1 (HO‑1), Bcl‑2 and Bcl‑xL mRNA, and HO‑1 protein were elevated, and the expression of p53 mRNA was decreased, particularly in the BH group (15 mg/kg). In conclusion, BBR exerts a protective action against CCl4‑induced acute liver injury in rats via effectively regulating the expression of Nrf2‑Keap1‑antioxidant responsive element‑related genes and proteins, and inhibiting p53 pathway‑mediated hepatocyte apoptosis.

Proteomic Analysis of Human Dermal Fibroblast Conditioned Medium (DFCM)

Growth factors and extracellular matrix (ECM) proteins are involved in wound healing. Human dermal fibroblasts secrete wound-healing mediators in culture medium known as dermal fibroblast conditioned medium (DFCM). However, the composition and concentration of the secreted proteins differ with culture conditions and environmental factors. We cultured human skin fibroblasts in vitro using serum-free keratinocyte-specific media (EpiLife™ Medium [KM1] and defined keratinocyte serum-free medium [KM2]) and serum-free fibroblast-specific medium (FM) to obtain DFCM-KM1, DFCM-KM2 and DFCM-FM, respectively. We identified and compared their proteomic profiles using bicinchoninic acid assay (BCA), 1-dimensional sodium dodecyl sulphate-polyacrylamide gel electrophoresis (1D SDS-PAGE), enzyme-linked immunosorbent assay (ELISA), matrix-assisted laser desorption ionisation-time-of-flight mass spectrometry (MALDI-TOF/TOF MS/MS) and liquid chromatography MS (LC-MS/MS). DFCM-KM1 and DFCM-KM2 had higher protein concentrations than DFCM-FM but not statistically significant. MALDI-TOF/TOF MS identified the presence of fibronectin, serotransferrin, serpin and serum albumin. LC-MS/MS and bioinformatics analysis identified 59, 46 and 58 secreted proteins in DFCM-KM1, DFCM-KM2 and DFCM-FM, respectively. The most significant biological processes identified in gene ontology were cellular process, metabolic process, growth and biological regulation. STRING® analysis showed that most secretory proteins in the DFCMs were associated with biological processes (e.g. wound healing and ECM organisation), molecular function (e.g. ECM binding) and cellular component (e.g. extracellular space). ELISA confirmed the presence of fibronectin and collagen in the DFCMs. In conclusion, DFCM secretory proteins are involved in cell adhesion, attachment, proliferation and migration, which were demonstrated to have potential wound-healing effects by in vitro and in vivo studies.

Endometrial injury increases expression of hypoxia-inducible factor and angiogenesis in the endometrium of women with recurrent implantation failure

RESEARCH QUESTION

The aim of this study was to compare expression of hypoxia-inducible factor 1-alpha (HIF-1α), angiogenesis and apoptosis in endometrial tissue near the implantation window of women with recurrent implantation failure (RIF) and in fertile control women, and to describe possible mechanisms of endometrial injury.

DESIGN

A controlled clinical study was conducted. Endometrial tissue specimens were obtained from 20 women undergoing IVF who had had at least three previous failed treatment cycles; normal endometrial specimens were obtained from 10 fertile control women.

RESULTS

HIF-1α expression was down-regulated in the endometrium of women with RIF compared with that of control women. In addition, micro-vessel density (MVD) was much lower in the endometrium of women with RIF than in that of the control women. Apoptosis was significantly reduced in the endometrium of the RIF group compared with the control group. Endometrial injury increased HIF-1α expression and MVD in endometrial samples of the RIF group, but apoptosis was not significantly altered.

CONCLUSIONS

HIF-1α expression, MVD and endometrial apoptosis were reduced in the peri-implantation endometrium of women with RIF. This suggests that altered endometrial HIF-1α expression and angiogenesis may contribute to implantation failure.

Multimodality Imaging in Tumor Angiogenesis: Present Status and Perspectives

Angiogenesis is a complex biological process that plays a central role in progression of tumor growth and metastasis. It led to a search for antiangiogenic molecules, and to design antiangiogenic strategies for cancer treatment. Noninvasive molecular imaging, such as positron emission tomography (PET) and single photon emission computed tomography (SPECT), could be useful for lesion detection, to select patients likely to respond to antiangiogenic therapies, to confirm successful targeting, and dose optimization. Additionally, nuclear imaging techniques could also aid in the development of new angiogenesis-targeted drugs and their validation. Angiogenesis imaging can be categorized as targeted at three major cell types: (I) non-endothelial cell targets, (II) endothelial cell targets, and (III) extracellular matrix proteins and matrix proteases. Even if radiopharmaceuticals studying the metabolism and hypoxia can be also used for the study of angiogenesis, many of the agents used in nuclear imaging for this purpose are yet to be investigated. The purpose of this review is to describe the role of molecular imaging in tumor angiogenesis, highlighting the advances in this field.

Targeting the vasculature in hepatocellular carcinoma treatment: Starving versus normalizing blood supply

Traditional treatments for intermediate or advanced stage hepatocellular carcinoma (HCC) such as transarterial chemoembolization (TACE) and anti-angiogenesis therapies were developed to starve tumor blood supply. A new approach of normalizing structurally and functionally abnormal tumor vasculature is emerging. While TACE improves survival in selected patients, the resulting tumor hypoxia stimulates proliferation, angiogenesis, treatment resistance and metastasis, which limits its overall efficacy. Vessel normalization decreases hypoxia and improves anti-tumor immune infiltrate and drug delivery. Several pre-clinical agents aimed at normalizing tumor vasculature in HCC appear promising. Although anti-angiogenic agents with vessel normalizing potential have been trialed in advanced HCC with modest results, to date their primary intention had been to starve the tumor. Judicious use of anti-angiogenic therapies is required to achieve vessel normalization yet avoid excessive pruning of vessels. This balance, termed the normalization window, is yet uncharacterized in HCC. However, the optimal class, dose and schedule of vascular normalization agents, alone or in combination with other therapies needs to be explored further.

Lentiviral vector-mediated co-overexpression of VEGF and Bcl-2 improves mesenchymal stem cell survival and enhances paracrine effects in vitro

Mesenchymal stem cell (MSC) transplantation has emerged as a promising therapy for ischemic heart disease; however, the low survival rate of transplanted cells limits their therapeutic efficacy. The aim of this study was to investigate whether the dual genetic modification of vascular endothelial growth factor (VEGF) and B-cell lymphoma-2 (Bcl-2) confers a higher expression level of the target genes, better survival and a stronger paracrine effect in MSCs in an adverse environment than the modification of the individual genes. For this purpse, a lentiviral vector was constructed by using a self-cleaving T2A peptide sequence to link and achieve the co-overexpression of VEGF and Bcl-2. Rat MSCs were transfected to obtain cell lines that exhibited a stable overexpression. An in vitro model of oxygen glucose deprivation (OGD) was applied to mimic the ischemic microenvironment, and cell apoptosis, autophagy and the paracrine effects were then determined. Compared with the MSCs in which individual genes were modified and the control MSCs, the MSCs which were subjected to dual genetic modification had a higher expression level of the target genes, a more rapid proliferation, reduced apoptosis, decreased autophagy and an enhanced paracrine effect. Furthermore, the suppression of autophagy was found to contribute to the inhibition of apoptosis in this in vitro OGD model. On the whole, these data indicate that the co-overexpression of VEGF and Bcl-2 protects MSCs in an ischemic environment by inhibiting apoptosis, suppressing autophagy and enhancing the paracrine effects.

Retinal Nerve Fiber Layer Thickness Changes in Age-Related Macular Degeneration Treated with Multiple Intravitreal Ranibizumab

PURPOSE

The objective of this study was to investigate the effect of multiple intravitreal ranibizumab (IVR) injections on the retinal nerve fiber layer (RNFL) in neovascular age-related macular degeneration (nAMD).

METHODS

One hundred sixty-eight eyes of 168 patients with nAMD who received an IVR at least 3 times were included in this prospective interventional case series. The RNFL thickness data on 80 healthy eyes, used as the control group, were obtained. The patients were grouped as follows: 3-10 injections (group 1, 62 eyes, 37%), 10-20 injections (group 2, 62 eyes, 37%), and ≥20 injections (group 3, 44 eyes, 26%). The RNFL thickness was measured by spectral domain optical coherence tomography.

RESULTS

The mean baseline measurement of the RNFL thickness was 97.4 ± 6.4 μm in the control group, 96.4 ± 5.6 μm in group 1, 93.8 ± 4.6 μm in group 2, and 93.2 ± 5.3 μm in group 3. At the last follow-up, it was 95.1 ± 2.4 μm in the control group, 93.4 ± 7.3 μm in group 1, 90.5 ± 3.6 μm in group 2, and 89.2 ± 4.9 μm in group 3 (all P values >0.050). A statistically significant difference was not found between the mean total RNFL thickness of the eyes that received injections and that of the eyes in the healthy control group (P value >0.050). A statistically significant difference was not found in all the treatment groups between the intraocular pressure level taken 1 day after the administration of the injections and that recorded preintervention (all P values >0.050).

CONCLUSION

Repeated IVR did not lead to a significant change in RNFL thickness in patients with nAMD.

14-3-3η is a novel growth-promoting and angiogenic factor in hepatocellular carcinoma

BACKGROUND & AIMS

Hepatocellular carcinoma (HCC) is one of the most common malignancies worldwide. The continued search for novel therapeutic strategies for HCC is urgently required. In this study, we aimed to investigate the functions and clinical significance of 14-3-3η protein in HCC.

METHODS

Expressions of genes and proteins were determined by quantitative reverse transcription polymerase chain reaction, Western blot, and immunohistochemistry. Their functions were assessed by endothelial cell recruitment, tube formation, wound healing, flow cytometry, immunostaining, immunoprecipitation, and xenograft assay. A tissue microarray followed by univariate and multivariate analyses was performed to indicate the clinical significance.

RESULTS

In HCC specimens, overexpression of 14-3-3η was observed not only in tumors but also in intratumoral vessels. In HCC and vascular endothelial cells, 14-3-3η stimulated proliferation and angiogenesis, but attenuated the functions of sorafenib. Briefly, 14-3-3η facilitated the phosphorylation of extracellular signal-regulated kinase1/2 (ERK1/2). Then, by binding to the phosphorylated-ERK1/2 (p-ERK1/2), formed a functional positive feed-back loop. A xenograft model showed that, blockage of either 14-3-3η or ERK1/2 inhibited the tumor growth. Finally, tissue microarray analyses showed that overexpression of 14-3-3η, either in tumors or intratumoral vessels, contributed to the poor survival.

CONCLUSIONS

The 14-3-3η-ERK1/2 feedback loop played a characteristic growth-promoting role in HCC, not only in tumors but also in intratumoral vessels. Further, 14-3-3η could be a potential therapeutic target for HCC and a biomarker for predicting sorafenib treatment response.

LAY SUMMARY

Here we found that, 14-3-3η protein exhibited a characteristic growth-promoting effect in both tumor and intratumoral vessels of hepatocellular carcinoma by interacting with ERK1/2 signaling.

The novel dual PI3K/mTOR inhibitor NVP-BGT226 displays cytotoxic activity in both normoxic and hypoxic hepatocarcinoma cells

Hepatocellular carcinoma (HCC) is one of the most common lethal human malignancies worldwide and its advanced status is frequently resistant to conventional chemotherapeutic agents and radiation. We evaluated the cytotoxic effect of the orally bioavailable dual PI3K/mTOR inhibitor, NVP-BGT226, on a panel of HCC cell lines, since hyperactivated PI3K/Akt/mTOR signaling pathway could represent a biomolecular target for Small Inhibitor Molecules in this neoplasia. We analyzed the drug activity in both normoxia and hypoxia conditions, the latter playing often a relevant role in the induction of chemoresistance and angiogenesis.In normoxia NVP-BGT226 caused cell cycle arrest in the G0/G1 phase of the cell cycle, induced apoptosis and autophagy at low concentrations. Interestingly the drug inactivated p-Akt and p-S6 at < 10 nM concentration.In hypoxia NVP-BGT226 maintained its cytotoxic efficacy at the same concentration as documented by MTT assays and Western blot analysis. Moreover, the drug showed in hypoxia inhibitory properties against angiogenesis by lowering the expression of the transcription factor HIF-1α and of VEGF.Our results indicate that NVP-BGT226 has a potent cytotoxic effect on HCC cell lines also in hypoxia condition, thus emerging as a potential candidate for cancer treatment in HCC targeted therapy.

HSPA12B: a novel facilitator of lung tumor growth

Lung tumor progression is regulated by proangiogenic factors. Heat shock protein A12B (HSPA12B) is a recently identified regulator of expression of proangiogenic factors. However, whether HSPA12B plays a role in lung tumor growth is unknown. To address this question, transgenic mice overexpressing HSPA12B (Tg) and wild-type littermates (WT) were implanted with Lewis lung cancer cells to induce lung tumorigenesis. Tg mice showed significantly higher number and bigger size of tumors than WT mice. Tg tumors exhibited increased angiogenesis and proliferation while reduced apoptosis compared with WT tumors. Interestingly, a significantly enhanced upregulation of Cox-2 was detected in Tg tumors than in WT tumors. Also, Tg tumors demonstrated upregulation of VEGF and angiopoietin-1, downregulation of AKAP12, and increased eNOS phosphorylation compared with WT tumors. Celecoxib, a selective Cox-2 inhibitor, suppressed the HSPA12B-induced increase in lung tumor burden. Moreover, celecoxib decreased angiogenesis and proliferation whereas increased apoptosis in Tg tumors. Additionally, celecoxib reduced angiopoietin-1 expression and eNOS phosphorylation but increased AKAP12 levels in Tg tumors. Our results indicate that HSPA12B stimulates lung tumor growth via a Cox-2-dependent mechanism. The present study identified HSPA12B as a novel facilitator of lung tumor growth and a potential therapeutic target for the treatment of lung cancer.

Signaling Interplay between Bone Marrow Adipose Tissue and Multiple Myeloma cells

In the year 2000, Hanahan and Weinberg (1) defined the six Hallmarks of Cancer as: self-sufficiency in growth signals, evasion of apoptosis, insensitivity to antigrowth mechanisms, tissue invasion and metastasis, limitless replicative potential, and sustained angiogenesis. Eleven years later, two new Hallmarks were added to the list (avoiding immune destruction and reprograming energy metabolism) and two new tumor characteristics (tumor-promoting inflammation and genome instability and mutation) (2). In multiple myeloma (MM), a destructive cancer of the plasma cell that grows predominantly in the bone marrow (BM), it is clear that all these hallmarks and characteristics are in play, contributing to tumor initiation, drug resistance, disease progression, and relapse. Bone marrow adipose tissue (BMAT) is a newly recognized contributor to MM oncogenesis and disease progression, potentially affecting MM cell metabolism, immune action, inflammation, and influences on angiogenesis. In this review, we discuss the confirmed and hypothetical contributions of BMAT to MM development and disease progression. BMAT has been understudied due to technical challenges and a previous lack of appreciation for the endocrine function of this tissue. In this review, we define the dynamic, responsive, metabolically active BM adipocyte. We then describe how BMAT influences MM in terms of: lipids/metabolism, hypoxia/angiogenesis, paracrine or endocrine signaling, and bone disease. We then discuss the connection between BMAT and systemic inflammation and potential treatments to inhibit the feedback loops between BM adipocytes and MM cells that support MM progression. We aim for researchers to use this review to guide and help prioritize their experiments to develop better treatments or a cure for cancers, such as MM, that associate with and may depend on BMAT.

BMP9-Induced Survival Effect in Liver Tumor Cells Requires p38MAPK Activation

The study of bone morphogenetic proteins (BMPs) role in tumorigenic processes, and specifically in the liver, has gathered importance in the last few years. Previous studies have shown that BMP9 is overexpressed in about 40% of hepatocellular carcinoma (HCC) patients. In vitro data have also shown evidence that BMP9 has a pro-tumorigenic action, not only by inducing epithelial to mesenchymal transition (EMT) and migration, but also by promoting proliferation and survival in liver cancer cells. However, the precise mechanisms driving these effects have not yet been established. In the present work, we deepened our studies into the intracellular mechanisms implicated in the BMP9 proliferative and pro-survival effect on liver tumor cells. In HepG2 cells, BMP9 induces both Smad and non-Smad signaling cascades, specifically PI3K/AKT and p38MAPK. However, only the p38MAPK pathway contributes to the BMP9 growth-promoting effect on these cells. Using genetic and pharmacological approaches, we demonstrate that p38MAPK activation, although dispensable for the BMP9 proliferative activity, is required for the BMP9 protective effect on serum withdrawal-induced apoptosis. These findings contribute to a better understanding of the signaling pathways involved in the BMP9 pro-tumorigenic role in liver tumor cells.

Downregulation of key regulatory proteins in androgen dependent prostate tumor cells by oncolytic reovirus

As prostate tumor cell growth depends on hormones, androgen ablation is an effective therapy for prostate cancer (PCa). However, progression of PCa cells to androgen independent growth (castrate resistant prostate cancer, CRPC) results in relapse and mortality. Hypoxia, a microenvironment of low oxygen that modifies the activity of PCa regulatory proteins including the androgen receptor (AR), plays a critical role in progression to CRPC. Therapies targeting hypoxia and the AR may lengthen the time to CRPC progression thereby increasing survival time of PCa patients. Mammalian Orthoreovirus (MRV) has shown promise for the treatment of prostate tumors in vitro and in vivo. In this study, we found that MRV infection induces downregulation of proteins implicated in CRPC progression, interferes with hypoxia-induced AR activity, and induces apoptosis in androgen dependent cells. This suggests MRV possesses traits that could be exploited to create novel therapies for the inhibition of progression to CRPC.

Matrix metalloproteinase 10 contributes to hepatocarcinogenesis in a novel crosstalk with the stromal derived factor 1/C-X-C chemokine receptor 4 axis

Matrix metalloproteinases (MMPs) participate in tissue repair after acute injury, but also participate in cancer by promoting a protumorigenic microenvironment. Previously, we reported on a key role for MMP10 in mouse liver regeneration. Herein, we investigated MMP10 expression and function in human hepatocellular carcinoma (HCC) and diethylnitrosamine (DEN)-induced mouse hepatocarcinogenesis. MMP10 was induced in human and murine HCC tissues and cells. MMP10-deficient mice showed less HCC incidence, smaller histological lesions, reduced tumor vascularization, and less lung metastases. Importantly, expression of the protumorigenic, C-X-C chemokine receptor-4 (CXCR4), was reduced in DEN-induced MMP10-deficient mice livers. Human HCC cells stably expressing MMP10 had increased CXCR4 expression and migratory capacity. Pharmacological inhibition of CXCR4 significantly reduced MMP10-stimulated HCC cell migration. Furthermore, MMP10 expression in HCC cells was induced by hypoxia and the CXCR4 ligand, stromal-derived factor-1 (SDF1), through the extracellular signal-regulated kinase 1/2 pathway, involving an activator protein 1 site in MMP10 gene promoter.

CONCLUSION

MMP10 contributes to HCC development, participating in tumor angiogenesis, growth, and dissemination. We identified a new reciprocal crosstalk between MMP10 and the CXCR4/SDF1 axis contributing to HCC progression and metastasis. To our knowledge, this is the first report addressing the role of a MMP in hepatocarcinogenesis in the corresponding genetic mouse model.

Effects of hypoxia inducible factor-1α on apoptotic inhibition and glucocorticoid receptor downregulation by dexamethasone in AtT-20 cells

BACKGROUND

Hypoxia inducible factor-1α (HIF-1α) is the central transcriptional regulator of hypoxic responses during the progression of pituitary adenomas. Although previous immunohistochemical studies revealed that HIF-1α is expressed in adreno-cortico-tropic-hormone (ACTH) pituitary adenomas, the role of HIF-1α remains unclear.

METHODS

AtT-20 cells were incubated under hypoxic conditions (1 % O2) for 12 h. HIF-1α mRNA and protein expression levels were measured by real-time PCR and western blotting, respectively. BrdU was used to determine the effects of hypoxia on cell viability. AtT-20 cells were transfected with siRNA targeting HIF-1α, followed by hypoxia (1 % O2) for 12 h. Apoptosis was determined by annexin V-FITC flow cytometry and Tdt-mediated dUTP nick end-labelling (TUNEL) assay. In addition, we examined interactions between HIF-1α, glucocorticoid receptor (GR), and dexamethasone under both normoxic and hypoxic conditions.

RESULTS

Hypoxia triggered the time-dependent proliferation of AtT-20 cells in association with increased HIF-1α mRNA and protein levels. However, the viability of AtT-20 cells decreased greatly when they were first transfected with HIF-1α-siRNA and then exposed to hypoxia. According to flow cytometry (annexin V-FITC and PI staining) and TUNEL analyses, a greater percentage of cells were apoptotic when transfected with HIF-1α siRNA and subsequently cultured under hypoxic conditions compared to those in the normoxia and mock groups. After AtT-20 cells were cultured in 1 % O2 and then treated with dexamethasone, HIF-1α levels significantly increased or decreased in normoxic or hypoxic conditions, respectively. Dexamethasone suppressed GR expression to a higher degree in hypoxic than normoxic conditions. Downregulation of GR by dexamethasone was greatly prevented in cells that were transfected with HIF-1α siRNA.

CONCLUSIONS

These findings strongly suggest that HIF-1α exerts an antiapoptotic role and participates in the downregulation of GR by dexamethasone in hypoxic AtT-20 cells.

Evaluating the SERCA2 and VEGF mRNAs as Potential Molecular Biomarkers of the Onset and Progression in Huntington's Disease

Abnormalities of intracellular Ca²⁺ homeostasis and signalling as well as the down-regulation of neurotrophic factors in several areas of the central nervous system and in peripheral tissues are hallmarks of Huntington’s disease (HD). As there is no therapy for this hereditary, neurodegenerative fatal disease, further effort should be made to slow the progression of neurodegeneration in patients through the definition of early therapeutic interventions. For this purpose, molecular biomarker(s) for monitoring disease onset and/or progression and response to treatment need to be identified. In the attempt to contribute to the research of peripheral candidate biomarkers in HD, we adopted a multiplex real-time PCR approach to analyse the mRNA level of targeted genes involved in the control of cellular calcium homeostasis and in neuroprotection. For this purpose we recruited a total of 110 subjects possessing the HD mutation at different clinical stages of the disease and 54 sex- and age-matched controls. This study provides evidence of reduced transcript levels of sarco-endoplasmic reticulum-associated ATP2A2 calcium pump (SERCA2) and vascular endothelial growth factor (VEGF) in peripheral blood mononuclear cells (PBMCs) of manifest and pre-manifest HD subjects. Our results provide a potentially new candidate molecular biomarker for monitoring the progression of this disease and contribute to understanding some early events that might have a role in triggering cellular dysfunctions in HD.

Sevoflurane attenuate hypoxia-induced VEGF level in tongue squamous cell carcinoma cell by upregulating the DNA methylation states of the promoter region

Anaesthetic agents were confirmed to play a role on the tumor angiogenesis. The effect of sevoflurane on tongue squamous cell carcinoma (TSCC) cell has not been investigated. SCC-4 cells were exposed to sevoflurane after simulating hypoxia. Then, both the mRNA and protein level of hypoxia-inducible factor (HIF)-1α and VEGF were detected. The methylation states of the VEGF promoter region were also assessed to reveal the underlying mechanism. Finally, the DNA methyltransferase inhibitor 5-aza-2'-deoxycytidine (5-Aza) was administrated to reveal the relationship of DNA methylation on the regulation of the VEGF level. Results showed that sevoflurane attenuated the hypoxia-induced VEGF level without altering the HIF-1α after exposure for 24 and 72 h. Sevoflurane increased the DNA methylation of the VEGF promoter region. The attenuation effect of sevoflurane on hypoxia-induced VEGF level could be blocked by 5-Aza. We concluded that sevoflurane attenuates hypoxia-induced VEGF level via DNA methylation of the promoter region in TSCC cell.

HIF-1α downregulation and apoptosis in hypoxic prostate tumor cells infected with oncolytic mammalian orthoreovirus

Hypoxia has emerged as one of the most important drivers of tumor aggression, metastasis, and poor clinical outcome in many cancers.In prostate cancer (PCa), hypoxia has been strongly correlated to biochemical failure and local recurrence. However, current PCa treatment options do not address hypoxic cells highlighting a critical gap in existing therapies and the need for development of therapies that target hypoxic prostate tumor cells. Mammalian orthoreovirus (MRV) is an oncolytic virus that targets tumor cells over normal cells which has been shown to be safe and effective against many cancers in vitro, in animal models, and in human clinical trials. We found that MRVinfects and replicates in hypoxic prostate tumor cells to levels comparable to normoxic cells leading to apoptosis and cell death. In addition, the regulatory subunit (HIF-1α) of the master transcriptional regulator of hypoxia, HIF-1, was significantly downregulated in infected cells. HIF-1α downregulation was found to occur via ubiquitin-dependent proteasome-mediated degradation and translational inhibition. Virus-mediated HIF-1α degradation required the HIF-1α PAS domain and expression of the receptor for activated kinase C (RACK1) protein. These data provide evidence that MRV may be a viable therapeutic option for targeting hypoxic cells and HIF-1α in PCa.

MiR-338-3p inhibits hepatocarcinoma cells and sensitizes these cells to sorafenib by targeting hypoxia-induced factor 1α

Hypoxia is a common feature of solid tumors and an important contributor to anti-tumor drug resistance. Hypoxia inducible factor-1 (HIF-1) is one of the key mediators of the hypoxia signaling pathway, and was recently proven to be required for sorafenib resistance in hepatocarcinoma (HCC). MicroRNAs have emerged as important posttranslational regulators in HCC. It was reported that miR-338-3p levels are associated with clinical aggressiveness of HCC. However, the roles of miR-338-3p in HCC disease and resistance to its therapeutic drugs are unknown. In this study, we found that miR-338-3p was frequently down-regulated in 14 HCC clinical samples and five cell lines. Overexpression of miR-338-3p inhibited HIF-1α 3'-UTR luciferase activity and HIF-1α protein levels in HepG2, SMMC-7721, and Huh7 cells. miR-338-3p significantly reduced cell viability and induced cell apoptosis of HCC cells. Additionally, HIF-1α overexpression rescued and HIF-1α knock-down abrogated the anti-HCC activity of miR-338-3p. Furthermore, miR-338-3p sensitized HCC cells to sorafenib in vitro and in a HCC subcutaneous nude mice tumor model by inhibiting HIF-1α. Collectively, miR-338-3p inhibits HCC tumor growth and sensitizes HCC cells to sorafenib by down-regulating HIF-1α. Our data indicate that miR-338-3p could be a potential candidate for HCC therapeutics.

Nitric oxide in cancer metastasis

Cancer metastasis is the spread and growth of tumor cells from the original neoplasm to further organs. This review analyzes the role of nitric oxide (NO), a signaling molecule, in the regulation of cancer formation, progression, and metastasis. The action of NO on cancer relies on multiple factors including cell type, metastasis stage, and organs involved. Various chemotherapy drugs cause cells to release NO, which in turn induces cytotoxic death of breast, liver, and skin tumors. However, NO has also been clinically connected to a poor cancer prognosis because of its role in angiogenesis and intravasation. This supports the claim that NO can be characterized as both pro-metastatic and anti-metastatic, depending on specific factors. The inhibition of cell proliferation and anti-apoptosis pathways by NO donors has been proposed as a novel therapy to various cancers. Studies suggest that NO-releasing non-steroidal anti-inflammatory drugs act on cancer cells in several ways that may make them ideal for cancer therapy. This review summarizes the biological significance of NO in each step of cancer metastasis, its controversial effects for cancer progression, and its therapeutic potential.

Upregulation of CD147 protects hepatocellular carcinoma cell from apoptosis through glycolytic switch via HIF-1 and MCT-4 under hypoxia

PURPOSE

Hypoxia is a vital factor in supporting and directing hepatocellular carcinoma (HCC) progression. HIF-1 transactivates target genes involved in metabolic reprogramming and antiapoptosis under hypoxia. However, key molecules involved in HCC hypoxia adaptation remain to be characterized. The aim of this study was to investigate the mechanism and biological function of CD147 on HCC cells resistant to apoptosis under hypoxic conditions.

METHODS

Apoptotic rates of hypoxia-treated HCC cells were investigated by flow cytometer, and the expression levels of CD147, HIF-1α, MCT-1 and MCT-4 were assayed by immune blot. The in vitro glycolytic capacity was investigated in SMMC-7721 cells and 7721-shCD147 cells (CD147 is stably knocked down). Immunohistochemical staining of CD147, Glut-1, MCT-1, MCT-4, LAT-1 and CD98 was detected in tumor tissues from a xenograft model. Immunofluorescence double-labeled staining allowed further exploration of the expression levels and localizations of CD147, MCT-1 and MCT-4.

RESULTS

Upregulation of CD147 under hypoxia correlates with higher viability of HCC cells compared with that in HSC cells. Silencing of CD147 significantly inhibited the glycolytic rate and induced apoptosis in SMMC-7721 cells. The expression level of lactate secretion transporter MCT-1/MCT-4 is dependent on CD147, while the expression level of Glut-1, LAT-1 and CD98 remained unchanged. Particularly, MCT-4 is demonstrated to be essential for the membranal localization of CD147.

CONCLUSIONS

With the above findings, we conclude that within the HCC hypoxic microenvironment, upregulation of CD147 and MCT-4 involved in glycolytic reprogramming is decisively important for the viability of HCC cells under hypoxia adaptation.

A novel resveratrol analogue, HS-1793, inhibits hypoxia-induced HIF-1α and VEGF expression, and migration in human prostate cancer cells

In many studies, resveratrol has been shown to have a chemopreventive effect in various types of cancer cells. However, the biological activity of resveratrol is limited by its photosensitivity and metabolic instability. This study investigated the effects of a novel analogue of resveratrol, HS-1793, on the expression of HIF-1α and vascular endothelial growth factor (VEGF) in PC-3 human prostate cancer cells. Hypoxic condition induced HIF-1α protein level in PC-3 cells in a time-dependent manner, and treatment with HS-1793 markedly decreased HIF-1α expression levels. HS-1793 also inhibited VEGF level. Mechanistically, HS-1793 inhibited HIF-1α and VEGF expression through multiple mechanisms. Firstly, HS-1793 inhibited phosphorylation of PI3K and Akt in PC-3 cells. Furthermore, HS-1793 substantially induced HIF-1α protein degradation through the proteasome pathway. Finally, HS-1793 inhibited hypoxia-induced PC-3 cell migration. These data suggest that HS-1793 may inhibit human prostate cancer progression and angiogenesis by inhibiting the expression of HIF-1α and VEGF. Moreover, HS-1793 showed more potent effects than resveratrol on the cytotoxic effects on PC-3 cells. Taken together, these results implied that HS-1793, a novel analogue of resveratrol, may be a new potent chemopreventive agent against human prostate cancer cells.

RNA interference targeting adrenomedullin induces apoptosis and reduces the growth of human bladder urothelial cell carcinoma

Adrenomedullin (ADM) is a potent, long-lasting angiogenic peptide that was originally isolated from human pheochromocytoma. ADM signaling is of particular significance in endothelial cell biology because the peptide protects cells from apoptosis, and ADM has been shown to be pro-tumorigenic in that it stimulates tumor cell growth and angiogenesis. ADM may be involved in micro-vessel proliferation and partially in the release of hypoxia in solid tumors, contributing to the proliferation of tumor cells as well as local tumor invasion and metastasis. However, the effect of hypoxia-induced ADM expression in bladder cancer remains unclear. Here, we found that the levels of ADM protein in tumor tissue from patients with bladder urothelial cell carcinoma were significantly increased compared to the adjacent non-tumor bladder tissues (p < 0.01). Under hypoxic conditions, the expression of ADM was significantly elevated in a time-dependent manner in human bladder cancer cell lines. Furthermore, the knockdown of ADM by shRNA in T24 cells showed obvious apoptosis compared to untransfected controls (p < 0.0001). In addition, the combination of cisplatin and ADM-shRNA significantly reduces the tumor growth in vivo compared to treatment with cisplatin (p = 0.0046) or ADM-shRNA alone (p < 0.0001). These data suggest that ADM plays an important role in promoting bladder cancer cell growth under hypoxia and that the inhibition of ADM may provide a target for bladder cancer therapy.

Prohibitin-2 promotes hepatocellular carcinoma malignancy progression in hypoxia based on a label-free quantitative proteomics strategy

The rapid growth of hepatocellular carcinoma (HCC) leading to tumor hypoxia is a common pathological phenomenon. Meanwhile, tumor hypoxia can promote a change in the biological properties of tumor cells. It may enhance the survival of tumor cells under stress conditions, resulting in resistance to apoptosis and angiogenesis. The moleculars that could modulate the malignant phenotypes of HCC cells remain largely unknown. Based on label-free quantitative proteomic data, we found a significant upregulation of prohibitin-2 (PHB2) in HCC tissues. Treatment of hepatoma cells with small interfering RNAs against PHB2 suppressed cell growth and colony formation, led to G1 phase arrest and sensitized HCC cells to apoptosis. Moreover, inhibition of PHB2 expression dramatically repressed the ability of HCC cells to adapt to hypoxic microenvironments and resist chemotherapy-induced apoptosis. Thus, PHB2 in HCC supports the development and progression of hepatocellular malignancy to hypoxia, and implicates the potential antagonist function of PHB2 in transarterial chemoembolization treatment.

Brucine, an indole alkaloid from Strychnos nux-vomica attenuates VEGF-induced angiogenesis via inhibiting VEGFR2 signaling pathway in vitro and in vivo

In this study, we investigated the mechanism of brucine in tumor angiogenesis. We found that brucine inhibits VEGF-induced cell proliferation, chemotactic motility, and the formation of capillary-like structures in HUVECs in a dose-dependent manner. Brucine suppresses VEGF- induced p-VEGFR2 kinase activity and inhibits neovascularization in vivo. Brucine inhibits the downstream protein kinases of VEGFR2, including Src, FAK, ERK, AKT and mTOR. And further downregulates levels of VEGF, NO, IL-6, IL-8, TNF-α and IFN-γ in HUVECs. Taken together, our study suggests that brucine potently suppresses angiogenesis by targeting VEGFR2 activation and may be a viable drug candidate in anti-angiogenesis and anti-cancer therapies.

Luteolin inhibits human prostate tumor growth by suppressing vascular endothelial growth factor receptor 2-mediated angiogenesis

Angiogenesis, the formation of new blood vessels from pre-existing vascular beds, is essential for tumor growth, invasion, and metastasis. Luteolin is a common dietary flavonoid found in fruits and vegetables. We studied the antiangiogenic activity of luteolin using in vitro, ex vivo, and in vivo models. In vitro studies using rat aortic ring assay showed that luteolin at non-toxic concentrations significantly inhibited microvessel sprouting and proliferation, migration, invasion and tube formation of endothelial cells, which are key events in the process of angiogenesis. Luteolin also inhibited ex vivo angiogenesis as revealed by chicken egg chorioallantoic membrane assay (CAM) and matrigel plug assay. Gelatin zymographic analysis demonstrated the inhibitory effect of luteolin on the activation of matrix metalloproteinases MMP-2 and MMP-9. Western blot analysis showed that luteolin suppressed VEGF induced phosphorylation of VEGF receptor 2 and their downstream protein kinases AKT, ERK, mTOR, P70S6K, MMP-2, and MMP-9 in HUVECs. Proinflammatory cytokines such as IL-1β, IL-6, IL-8, and TNF-α level were significantly reduced by the treatment of luteolin in PC-3 cells. Luteolin (10 mg/kg/d) significantly reduced the volume and the weight of solid tumors in prostate xenograft mouse model, indicating that luteolin inhibited tumorigenesis by targeting angiogenesis. CD31 and CD34 immunohistochemical staining further revealed that the microvessel density could be remarkably suppressed by luteolin. Moreover, luteolin reduced cell viability and induced apoptosis in prostate cancer cells, which were correlated with the downregulation of AKT, ERK, mTOR, P70S6K, MMP-2, and MMP-9 expressions. Taken together, our findings demonstrate that luteolin inhibits human prostate tumor growth by suppressing vascular endothelial growth factor receptor 2-mediated angiogenesis.

Identification of active compounds from Aurantii Immatri Pericarpium attenuating brain injury in a rat model of ischemia-reperfusion

Ischemic stroke is caused by brain injury due to prolonged ischemia by occlusion of cerebral arteries. In this study, we isolated active compounds from an ethanol extract of Aurantii Immatri Pericarpium (HY5356). We first showed by DNA fragmentation assay that HY5356 improved human hepatocellular carcinoma cells (HepG2) under hypoxic conditions by inhibiting apoptosis. When HY5356 was fractionated with dichloromethane (MC), ethyl acetate (EA) and n-butanol (BU), the MC fraction improved cell viability at the lowest concentration (100 μg/ml). Intraperitoneal injection of HY5356 (200 mg/kg) or the MC fraction (200 mg/kg) to rats prior to occlusion attenuated brain injury significantly in a rat model of ischemia-reperfusion. Adopting cell viability under hypoxic conditions as an activity screening system, we isolated nobiletin and tangeretin as active compounds. The results suggest that intake of Aurantii Immatri Pericarpium containing nobiletin and tangeretin as active compounds might be beneficial for preventing ischemic stroke.

Involvement of Src in the Adaptation of Cancer Cells under Microenvironmental Stresses

Protein-tyrosine phosphorylation, which is catalyzed by protein-tyrosine kinase (PTK), plays a pivotal role in a variety of cellular functions related to health and disease. The discovery of the viral oncogene Src (v-Src) and its cellular nontransforming counterpart (c-Src), as the first example of PTK, has opened a window to study the relationship between protein-tyrosine phosphorylation and the biology and medicine of cancer. In this paper, we focus on the roles played by Src and other PTKs in cancer cell-specific behavior, that is, evasion of apoptosis or cell death under stressful extracellular and/or intracellular microenvironments (i.e., hypoxia, anoikis, hypoglycemia, and serum deprivation).

Novel antiangiogenic therapies against advanced hepatocellular carcinoma (HCC)

Angiogenesis is a cornerstone in the process of hepatocarcinogenesis. In the sorafenib era, other antiangiogenic targeted drugs, such as monoclonal antibodies and a new generation of tyrosine kinase inhibitors, have been shown in phase II trials to be safe and effective in the treatment of advanced hepatocellular carcinoma. Several currently active phase III trials are testing these drugs, both in first- and second-line settings. Strategies to overcome primary and acquired resistance to antiangiogenic therapy are urgently needed. Novel biomarkers may help in improving the efficacy of drugs targeting angiogenesis.

Effect of resveratrol on Bcl-2 and VEGF expression in oxygen-induced retinopathy of prematurity

PURPOSE

To explore the effect of resveratrol on B-cell leukemia/lymphoma-2 (Bcl-2) and vascular endothelial growth factor (VEGF) expression in rats with oxygen-induced retinopathy of prematurity (ROP).

METHODS

Seven-day-old Sprague-Dawley rats (N = 60) were randomly assigned to five groups. Group A received normal partial oxygen pressure and groups B, C, D, and E received 75% ± 2% oxygen for 5 days to induce ROP. The rats in groups C, D, and E were intragastrically treated with resveratrol (10, 30, and 60 mg/kg/d, respectively) once daily for 5 days. Rats were killed at 17 days of age and the retina was collected.

RESULTS

Western blot analysis revealed increased Bcl-2 protein expression in group B versus group A. Levels of Bcl-2 decreased with the increase of resveratrol concentration in groups C, D, and E. The optical density of Bcl-2 protein expression in group B was four times higher than that in group A (P < .01). When compared with group B, expression of Bcl-2 and VEGF in groups C, D, and E decreased in a dose-dependent manner. Significant differences in expression of Bcl-2 and VEGF were also noted among the three treatment groups with resveratrol (P < .01). After treatment with resveratrol at 10, 30, and 60 mg/kg/d, the inhibition rate of Bcl-2 expression was 11.1%, 38.1%, and 69.8% and that of VEGF expression was 3.4%, 23.0%, and 43.7%, respectively.

CONCLUSION

Resveratrol can significantly inhibit expression of Bcl-2 and VEGF in the retina of neonatal rats with oxygen-induced ROP. It may provide a protective effect on retinal neovascular diseases, including ROP.