The impact of O2 availability on human cancer

Hypoxia A Typical Target in Human Lung Cancer Therapy

Lung cancer (LC) is the leading cause of cancer-related death globally. Comprehensive knowledge of the cellular and molecular etiology of LC is perilous for the development of active treatment approaches. Hypoxia in cancer is linked with malignancy, and its phenotype is implicated in the hypoxic reaction, which is being studied as a prospective cancer treatment target. The hypervascularization of the tumor is the main feature of human LC, and hypoxia is a major stimulator of neo-angiogenesis. It was seen that low oxygen levels in human LC are a critical aspect of this lethal illness. However, as there is a considerable body of literature espousing the presumed functional relevance of hypoxia in LC, the direct measurement of oxygen concentration in Human LC is yet to be determined. This narrative review aims to show the importance and as a future target for novel research studies that can lead to the perception of LC therapy in hypoxic malignancies.

Glucosylated Hybrid TiO2 /Polymer Nanomaterials for Actively Targeted Sonodynamic Therapy of Cancer

Sonodynamic therapy (SDT) is an anti-cancer therapeutic strategy based on the generation of reactive oxygen species (ROS) upon local ultrasound (US) irradiation of sono-responsive molecules or nanomaterials that accumulate in the tumor. In this work, the sonodynamic efficiency of sono-responsive hybrid nanomaterials composed of amorphous titanium dioxide and an amphiphilic poly(ethylene oxide)-b-poly(propylene oxide) block copolymer is synthesized, fully characterized, and investigated both in vitro and in vivo. The modular and versatile synthetic pathway enables the control of the nanoparticle size between 30 and 300 nm (dynamic light scattering) and glucosylation of the surface for active targeting of tumors overexpressing glucose transporters. Studies on 2D and 3D rhabdomyosarcoma cell cultures reveal a statistically significant increase in the sonodynamic efficiency of glucosylated hybrid nanoparticles with respect to unmodified ones. Using a xenograft rhabdomyosarcoma murine model, it is demonstrated that by tuning the nanoparticle size and surface features, the tumor accumulation is increased by ten times compared to main off-target clearance organs such as the liver. Finally, the SDT of rhabdomyosarcoma-bearing mice is investigated with 50-nm glucosylated nanoparticles. Findings evidence a dramatic prolongation of the animal survival and tumor volumes 100 times smaller than those treated only with ultrasound or nanoparticles.

Identification of MDK as a Hypoxia- and Epithelial-Mesenchymal Transition-Related Gene Biomarker of Glioblastoma Based on a Novel Risk Model and In Vitro Experiments

BACKGROUND

Tumor cells are commonly exposed to a hypoxic environment, which can easily induce the epithelial-mesenchymal transition (EMT) of tumor cells, further affecting tumor proliferation, invasion, metastasis, and drug resistance. However, the predictive role of hypoxia and EMT-related genes in glioblastoma (GBM) has not been investigated.

METHODS

Intersection genes were identified by weighted correlation network analysis (WGCNA) and differential expression analyses, and a risk model was further constructed by LASSO and Cox analyses. Clinical, immune infiltration, tumor mutation, drug treatment, and enrichment profiles were analyzed based on the risk model. The expression level of the MDK gene was tested using RT-PCR, immunohistochemistry, and immunofluorescence. CCK8 and EdU were employed to determine the GBM cells' capacity for proliferation while the migration and invasion ability were detected by a wound healing assay and transwell assay, respectively.

RESULTS

Based on the GBM data of the TCGA and GTEx databases, 58 intersection genes were identified, and a risk model was constructed. The model was verified in the CGGA cohort, and its accuracy was confirmed by the ROC curve (AUC = 0.807). After combining clinical subgroups, univariate and multivariate Cox regression analyses showed that risk score and age were independent risk factors for GBM patients. Furthermore, our subsequent analysis of immune infiltration, tumor mutation, and drug treatment showed that risk score and high- and low-risk groups were associated with multiple immune cells, mutated genes, and drugs. Enrichment analysis indicated that the differences between high- and low-risk groups were manifested in tumor-related pathways, including the PI3K-AKT and JAK-STAT pathways. Finally, in vivo experiments proved that the hypoxia environment promoted the expression of MDK, and MDK knockdown reduced the proliferation, migration, and EMT of GBM cells induced by hypoxia.

CONCLUSIONS

Our novel prognostic correlation model provided more potential treatment strategies for GBM patients.

Evaluation of the effects of simulated hypoxia by CoCl2 on radioresistance and change of hypoxia-inducible factors in human glioblastoma U87 tumor cell line

PURPOSE

Glioblastoma (GBM) is considered the most common and lethal type of brain tumor with a poor prognosis. GBM treatment has challenges due to its aggressive nature, which often causes treatment failure and recurrence. Hypoxia is one of the characteristics of glioblastoma tumors that contribute to radioresistance and malignant phenotypes of GBM. In this study, we aimed to determine the effects of hypoxia on the radiosensitivity of U87 GBM cells by the hypoxia-mimicking model.

METHODS

Following the treatment of cells with different concentrations of CoCl2, an MTT assay was used to evaluate the cytotoxicity of CoCl2. To understand the effects of Ionizing radiation on CoCl2-treated groups, cells were exposed to irradiation after pretreating with 100 μM CoCl2, and a clonogenic survival assay was performed to determine the radiosensitivity of U87 cells. Also, the intracellular Reactive oxygen level was measured by 2',7'-dichlorofluorescein diacetate (DCFDA) probe staining. Additionally, the expression of hypoxia-associated genes, including HIF-1α, HIF-2α, and their target genes (GLUT-1), was monitored by reverse transcription polymerase chain reaction (RT-PCR).

RESULTS

Our study revealed that the cell viability of CoCl2-treated cells was decreased in a concentration-dependent manner. Also, CoCl2 did not cause any cytotoxicity on U87 cells at a concentration of 100 μM after treatment for 24 h. Colony formation assay showed that CoCl2 pretreatment induced radioresistance of tumor cells compared to non-treated cells. Also, CoCl2 can protect cells against irradiation by the clearance of ROS. Moreover, Real-time results showed that the mRNA expression of HIF-1α and GLUT-1 were significantly upregulated following hypoxia induction and/or irradiation condition. However, the level of HIF-2α mRNA did not change significantly in hypoxia or irradiation alone conditions, but it increased significantly only in hypoxia + irradiation conditions.

CONCLUSION

Taken together, our results indicated that simulating hypoxia by CoCl2 can effectively increase hypoxia-associated genes, specially HIF-1α and GLUT-1, but did not affect HIF-2α gene expression. Also, it can increase the clearance of ROS, respectively, and it leads to inducing radioresistance of U87 cells.

Exploration and validation of a combined Hypoxia and m6A/m5C/m1A regulated gene signature for prognosis prediction of liver cancer

BACKGROUND

It is widely acknowledged that hypoxia and m6A/m5C/m1A RNA modifications promote the occurrence and development of tumors by regulating the tumor microenvironment. This study aimed to establish a novel liver cancer risk signature based on hypoxia and m6A/m5C/m1A modifications.

METHODS

We collected data from The Cancer Genome Atlas (TCGA-LIHC), the National Omics Data Encyclopedia (NODE-HCC), the International Cancer Genome Consortium (ICGC), and the Gene Expression Omnibus (GEO) databases for our study (GSE59729, GSE41666). Using Cox regression and least absolute shrinkage and selection operator (LASSO) method, we developed a risk signature for liver cancer based on differentially expressed genes related to hypoxia and genes regulated by m6A/m5C/m1A modifications. We stratified patients into high- and low-risk groups and assessed differences between these groups in terms of gene mutations, copy number variations, pathway enrichment, stemness scores, immune infiltration, and predictive capabilities of the model for immunotherapy and chemotherapy efficacy.

RESULTS

Our analysis revealed a significantly correlated between hypoxia and methylation as well as m6A/m5C/m1A RNA methylation. The three-gene prognosis signature (CEP55, DPH2, SMS) combining hypoxia and m6A/m5C/m1A regulated genes exhibited strong predictive performance in TCGA-LIHC, NODE-HCC, and ICGC-LIHC-JP cohorts. The low-risk group demonstrated a significantly better overall survival compared to the high-risk group (p < 0.0001 in TCGA, p = 0.0043 in NODE, p = 0.0015 in ICGC). The area under the curve (AUC) values for survival at 1, 2, and 3 years are all greater than 0.65 in the three cohorts. Univariate and Multivariate Cox regression analyses of the three datasets indicated that the signature could serve as an independent prognostic predictor (p < 0.001 in the three cohorts). The high-risk group exhibited more genome changes and higher homologous recombination deficiency scores and stemness scores. Analysis of immune infiltration and immune activation confirmed that the signature was associated with various immune microenvironment characteristics. Finally, patients in the high-risk group experienced a more favorable response to immunotherapy, and various common chemotherapy drugs.

CONCLUSION

Our prognostic signature which integrates hypoxia and m6A/m5C/m1A-regulated genes, provides valuable insights for clinical prediction and treatment guidance for liver cancer patients.

Association of hypoxia-inducible factor 1α expression with susceptibility to hepatitis B virus-related hepatocellular carcinoma: A meta-analysis

Hypoxia-inducible factor 1α (HIF-1α) triggers tumorigenesis and progression in hepatitis B virus (HBV)-related hepatocellular carcinoma (HCC). Inconsistent findings have been reported on the influence of HIF-1α over-expression on the clinical outcomes of HBV-related HCC. This study aims to clarify the role of HIF-1α overexpression in the tumorigenesis and prognosis of HBV-induced HCC. Systematic and comprehensive search of online papers was carried out to elucidate the contribution of HIF-1α expression to susceptibility of HBV-induced HCC. STATA 12.0 software was utilized to analyze available data extracted from all eligible literature. Publication bias and sensitivity were comprehensively analyzed. A total of 23 published studies involving 2244 subjects were finally screened. The HIF-1α expression was remarkably upregulated in HBV-induced HCC tissues than in normal liver tissues, non-tumorous tissues, paraneoplastic tissues, and non-HBV HCC tissues. The high HIF-1α expression tended to be positively related to capsular infiltration (odds ratio (OR) 1.767; 95% confidence interval (CI) 1.058, 2.950). The HIF-1α expression was relevant to lymph node metastasis (OR 3.778; 95% CI 1.666, 8.568). High levels of HIF-1α expression tended to be closely implicated in portal vein invasion (OR 6.728, 95% CI 2.191, 20.656) but were irrelevant to alpha-fetoprotein, cirrhosis, Edmondson grading, tumor size, age, gender, and histological grade. Analysis of pooled data showed that HIF-1α was not statistically relevant to poor overall survival in HBV-related HCC. Our data provides compelling evidence that HIF-1α overexpression may imply a greater probability of invasion and metastasis in patients with HBV-induced HCC.

HILPS, a long noncoding RNA essential for global oxygen sensing in humans

Adaptation to low levels of oxygen (hypoxia) is a universal biological feature across metazoans. However, the unique mechanisms how different species sense oxygen deprivation remain unresolved. Here, we functionally characterize a novel long noncoding RNA (lncRNA), LOC105369301, which we termed hypoxia-induced lncRNA for polo-like kinase 1 (PLK1) stabilization (HILPS). HILPS exhibits appreciable basal expression exclusively in a wide variety of human normal and cancer cells and is robustly induced by hypoxia-inducible factor 1α (HIF1α). HILPS binds to PLK1 and sequesters it from proteasomal degradation. Stabilized PLK1 directly phosphorylates HIF1α and enhances its stability, constituting a positive feed-forward circuit that reinforces oxygen sensing by HIF1α. HILPS depletion triggers catastrophic adaptation defect during hypoxia in both normal and cancer cells. These findings introduce a mechanism that underlies the HIF1α identity deeply interconnected with PLK1 integrity and identify the HILPS-PLK1-HIF1α pathway as a unique oxygen-sensing axis in the regulation of human physiological and pathogenic processes.

O2-Generation-Enhanced Responsive Starvation/Photothermal Synergistic Tumor Therapy Based on the AuNRs@MnO2@SiO2 Nanocarrier and Thermosensitive Biomimetic Camouflaging

Cancer starvation/photothermal combined tumor therapy (CST/PTT) has attracted great interest attributed to their mutual compensation and synergistically enhanced effect. However, the very low O2 supply in the tumor microenvironment (TME) greatly limits the CST efficiency of glucose oxidase (GOx). Additionally, the easy degradation in blood circulation and significant off-target effects are big challenges for clinical applications of the GOx-based CST. In this study, a drug delivery system (DDS) with specific tumor-targeted GOx delivery, near-infrared (NIR) light and TME responsive O2 generation, NIR-responsive glucose consumption, high GOx loading, and efficient NIR photothermia was developed. Positively charged AuNRs@MnO2@SiO2 nanoparticles (named AMS+ NPs) were synthesized. GOx was covalently loaded with a high loading ratio of 36.0%. Finally, a thermosensitive biomimetic hybrid membrane composed of a thermosensitive lipid (TSL) membrane, red blood cell membrane (RBCM), and 4T1 cancer cell membrane (CCM) was coated on the NPs through a double-layer strategy. The AMS+-G@TSL@[RBC-CC-TSL]M NPs consumed 32.7 times glucose at 50 °C as that at 37 °C and generated 4.9 times O2 upon NIR laser irradiation. The thermosensitive biomimetic NPs showed an efficient targeting capability to the homotypic 4T1 cancer cells/tumors accompanied by good biocompatibility, macrophage evading capability, high cancer cell cytotoxicity, and excellent antitumor efficacy. The tumor growth inhibition ratio with NIR laser irradiation reached 92.8%. The AMS+-GOx@TSL@[RBC-CC-TSL]M NPs provide a smart, efficient, safe, PTT/CST combined DDS for highly efficient tumor therapy.

Camptothecin-based prodrug nanomedicines for cancer therapy

Camptothecin (CPT) is a cytotoxic alkaloid that attenuates the replication of cancer cells via blocking DNA topoisomerase 1. Despite its encouraging and wide-spectrum antitumour activity, its application is significantly restricted owing to its instability, low solubility, significant toxicity, and acquired tumour cell resistance. This has resulted in the development of many CPT-based therapeutic agents, especially CPT-based nanomedicines, with improved pharmacokinetic and pharmacodynamic profiles. Specifically, smart CPT-based prodrug nanomedicines with stimuli-responsive release capacity have been extensively explored owing to the advantages such as high drug loading, improved stability, and decreased potential toxicity caused by the carrier materials in comparison with normal nanodrugs and traditional delivery systems. In this review, the potential strategies and applications of CPT-based nanoprodrugs for enhanced CPT delivery toward cancer cells are summarized. We appraise in detail the chemical structures and release mechanisms of these nanoprodrugs and guide materials chemists to develop more powerful nanomedicines that have real clinical therapeutic capacities.

Optimizing CAR-T Therapy for Glioblastoma

Chimeric antigen receptor T-cell therapies have transformed the management of hematologic malignancies but have not yet demonstrated consistent efficacy in solid tumors. Glioblastoma is the most common primary malignant brain tumor in adults and remains a major unmet medical need. Attempts at harnessing the potential of chimeric antigen receptor T-cell therapy for glioblastoma have resulted in glimpses of promise but have been met with substantial challenges. In this focused review, we discuss current and future strategies being developed to optimize chimeric antigen receptor T cells for efficacy in patients with glioblastoma, including the identification and characterization of new target antigens, reversal of T-cell dysfunction with novel chimeric antigen receptor constructs, regulatable platforms, and gene knockout strategies, and the use of combination therapies to overcome the immune-hostile microenvironment.

Hypoxia-induced SKA3 promoted cholangiocarcinoma progression and chemoresistance by enhancing fatty acid synthesis via the regulation of PAR-dependent HIF-1a deubiquitylation

BACKGROUND

Spindle and kinetochore-associated complex subunit 3 (SKA3) plays an important role in cell proliferation by regulating the separation of chromosomes and their division into daughter cells. Previous studies demonstrated that SKA3 was strongly implicated in tumor development and progression. However, the roles of SKA3 in cholangiocarcinoma (CCA) and the underlying mechanisms remain unclear.

METHODS

Next-generation sequencing (NGS) was performed with paired CCA tissues and normal adjacent tissues (NATs). SKA3 was chose to be the target gene because of its remarkably upregulation and unknown function in cholangiocarcinoma in TCGA datasets, GSE107943 datasets and our sequencing results. RT-PCR and immunohistochemistry staining were used to detect the expression of SKA3 in paired CCA tissues and normal adjacent tissues. The SKA3 knockdown and overexpression cell line were constructed by small interfering RNA and lentivirus vector transfection. The effect of SKA3 on the proliferation of cholangiocarcinoma under hypoxic conditions was detected by experiments in vitro and in vivo. RNA-seq was used to find out the differentially expressed pathways in cholangiocarcinoma proliferation under hypoxia regulated by SKA3. IP/MS analysis and Western blot assays were used to explore the specific mechanism of SKA3 in regulating the expression of HIF-1a under hypoxia.

RESULTS

SKA3 was up-regulated in NGS, TCGA and GSE107943 databases and was associated with poor prognosis. Functional experiments in vitro and in vivo showed that hypoxia-induced SKA3 promoted cholangiocarcinoma cell proliferation. RNA-sequencing was performed and verified that SKA3 enhanced fatty acid synthesis by up-regulating the expression of key fatty acid synthase, thus promoting cholangiocarcinoma cell proliferation under hypoxic conditions. Further studies indicated that under hypoxic conditions, SKA3 recruited PARP1 to bind to HIF-1a, thus enhancing the poly ADP-ribosylation (PARylation) of HIF-1a. This PARylation enhanced the binding between HIF-1a and USP7, which triggered the deubiquitylation of HIF-1a under hypoxic conditions. Additionally, PARP1 and HIF-1a were upregulated in CCA and promoted CCA cell proliferation. SKA3 promoted CCA cell proliferation and fatty acid synthesis via the PARP1/HIF-1a axis under hypoxic conditions. High SKA3 and HIF-1a expression levels were associated with poor prognosis after surgery.

CONCLUSION

Hypoxia-induced SKA3 promoted CCA progression by enhancing fatty acid synthesis via the regulation of PARylation-dependent HIF-1a deubiquitylation. Furthermore, increased SKA3 level enhanced chemotherapy-resistance to gemcitabine-based regimen under hypoxic conditions. SKA3 and HIF-1a could be potential oncogenes and significant biomarkers for the analysis of CCA patient prognosis.

Transition metals in angiogenesis - A narrative review

The aim of this paper is to offer a narrative review of the literature regarding the influence of transition metals on angiogenesis, excluding lanthanides and actinides. To our knowledge there are not any reviews up to date offering such a summary, which inclined us to write this paper. Angiogenesis describes the process of blood vessel formation, which is an essential requirement for human growth and development. When the complex interplay between pro- and antiangiogenic mediators falls out of balance, angiogenesis can quickly become harmful. As it is so fundamental, both its inhibition and enhancement take part in various diseases, making it a target for therapeutic treatments. Current methods come with limitations, therefore, novel agents are constantly being researched, with metal agents offering promising results. Various transition metals have already been investigated in-depth, with studies indicating both pro- and antiangiogenic properties, respectively. The transition metals are being applied in various formulations, such as nanoparticles, complexes, or scaffold materials. Albeit the increasing attention this field is receiving, there remain many unanswered questions, mostly regarding the molecular mechanisms behind the observed effects. Notably, approximately half of all the transition metals have not yet been investigated regarding potential angiogenic effects. Considering the promising results which have already been established, it should be of great interest to begin investigating the remaining elements whilst also further analyzing the established effects.

LINC02774 inhibits glycolysis in glioma to destabilize HIF-1α dependent on transcription factor RP58

Glioma, the most common of malignant tumors in the brain, is responsible for the majority of deaths from primary brain tumors. The regulation of long noncoding RNAs (lncRNAs) in HIF-1α-driven tumor development remains unclear. LINC02774 is a nuclear lncRNA and that it is being reported for the first time in this study. We found the downregulation of LINC02774 in glioma and decreased with the degree of malignant, with its expression showing a negative correlation with the relative index of enhanced magnetic resonance (RIEMR). RIEMR-associated LINC02774 was found to inhibit glycolysis by modulating the hypoxia pathway rather than the hypoxia response itself. LINC02774 interacted with its neighboring gene, RP58 (ZBTB18), to enhance the expression of PHD3, which catalyzed HIF-1α hydroxylase and ubiquitination, leading to the downregulation of HIF-1α expression. We also found that the function of LINC02774, dependent on PHD3, was diminished upon RP58 depletion. Notably, higher expression of RIEMR-associated LINC02774 was associated with a favorable prognosis. In conclusion, these findings reveal the role of RIEMR-associated LINC02774, which relies on its neighbor gene, RP58, to regulate the hypoxia pathway as a novel tumor suppressor, suggesting its potential to be a prognostic marker and a molecular target for the therapy of glioma.

Identification of a Novel Hypoxia-induced Inflammatory Cell Death Pathway

Hypoxic cancer cells resist many anti-neoplastic therapies and can seed recurrence. We found previously that PTP1B deficiency promotes HER2+ breast cancer cell death in hypoxia by activating RNF213, an ∼600kDa protein containing AAA-ATPase domains and two ubiquitin ligase domains (RING and RZ) that also is implicated in Moyamoya disease (MMD), lipotoxicity, and innate immunity. Here we report that PTP1B and ABL1/2 reciprocally control RNF213 phosphorylation on tyrosine-1275. This phosphorylation promotes RNF213 oligomerization and RZ domain activation. The RZ domain ubiquitylates CYLD/SPATA2, and together with the LUBAC complex, induces their degradation. Decreased CYLD/SPATA2 causes NF-κB activation, which together with hypoxia-induced ER-stress triggers GDSMD-dependent pyroptosis. Mutagenesis experiments show that the RING domain negatively regulates the RZ domain. CYLD -deleted HER2+ cell-derived xenografts phenocopy the effects of PTP1B deficiency, and reconstituting RNF213 knockout lines with RNF213 mutants shows that the RZ domain mediates PTP1B-dependent tumor cell death. Our results identify a novel, potentially targetable PTP1B/RNF213/CYCLD/SPATA pathway critical for controlling inflammatory cell death in hypoxic tumors that could be exploited to target hypoxic tumor cells, potentially turning "cold" tumors "hot". Our findings also reveal new insights into RNF213 regulation, and have potentially important implications for the pathogenesis of MMD, atherosclerosis, and inflammatory and auto-immune disorders.

Antiangiogenic Action of JZL184 on Endothelial Cells via Inhibition of VEGF Expression in Hypoxic Lung Cancer Cells

JZL184, an inhibitor of monoacylglycerol lipase (MAGL) and thus of the degradation of the endocannabinoid 2-arachidonoylglycerol (2-AG), mediates various anticancer effects in preclinical studies. However, studies on the effect of this or other MAGL inhibitors under hypoxia, an important factor in tumor biology and response to cancer therapy, have not yet been performed in cancer cells. In the present study, the impact of the conditioned media (CM) of A549 and H358 lung cancer cells incubated with JZL184 under hypoxic conditions on the angiogenic properties of human umbilical vein endothelial cells (HUVECs) was investigated. Treatment of HUVECs with CM derived from cancer cells cultured for 48 h under hypoxic conditions was associated with a substantial increase in migration and tube formation compared with unconditioned medium, which was inhibited when cancer cells were incubated with JZL184. In this process, JZL184 led to a significant increase in 2-AG levels in both cell lines. Analysis of a panel of proangiogenic factors revealed inhibition of hypoxia-induced vascular endothelial growth factor (VEGF) expression by JZL184. Antiangiogenic and VEGF-lowering effects were also demonstrated for the MAGL inhibitor MJN110. Receptor antagonist experiments suggest partial involvement of the cannabinoid receptors CB1 and CB2 in the antiangiogenic and VEGF-lowering effects induced by JZL184. The functional importance of VEGF for angiogenesis in the selected system is supported by observations showing inhibition of VEGF receptor 2 (VEGFR2) phosphorylation in HUVECs by CM from hypoxic cancer cells treated with JZL184 or when hypoxic cancer cell-derived CM was spiked with a neutralizing VEGF antibody. On the other hand, JZL184 did not exert a direct effect on VEGFR2 activation induced by recombinant VEGF, so there seems to be no downstream effect on already released VEGF. In conclusion, these results reveal a novel mechanism of antiangiogenic action of JZL184 under conditions of hypoxic tumor-endothelial communication.

14-3-3σ-NEDD4L axis promotes ubiquitination and degradation of HIF-1α in colorectal cancer

A hypoxic microenvironment contributes to tumor progression, with hypoxia-inducible factor-1α (HIF-1α) being a critical regulator. We have reported that 14-3-3σ is negatively associated with HIF-1α expression; however, its role in hypoxia-induced tumor progression remains poorly characterized. Here we show that 14-3-3σ suppresses cancer hypoxia-induced metastasis and angiogenesis in colorectal cancer (CRC). 14-3-3σ opposes HIF-1α expression by regulating the protein stability of HIF-1α, thereby decreasing HIF-1α transcriptional activity and suppressing tumor progression. Mechanistic studies show that the 14-3-3σ-interacting protein neural precursor cell-expressed developmentally down-regulated 4-like (NEDD4L) is an E3 ligase that targets HIF-1α. 14-3-3σ promotes the binding of S448-phosphorylated NEDD4L to HIF-1α, thereby enhancing HIF-1α poly-ubiquitination and subsequent proteasome-mediated degradation. Consistent with this anti-tumorigenic function for 14-3-3σ, low 14-3-3σ expression levels correlate with poor CRC patient survival, and 14-3-3σ enhances the response of CRC to bevacizumab. These results reveal an important mechanism for 14-3-3σ in tumor suppression through HIF-1α regulation.

Angiogenesis and prostate cancer: MicroRNAs comes into view

Angiogenesis, the formation of new blood vessels, is an important stage in the growth of cancer. Extracellular matrix, endothelial cells, and soluble substances must be carefully coordinated during the multistep procedure of angiogenesis. Inducers and inhibitors have been found to control pretty much every phase. In addition to benign prostatic hyperplasia, prostatic intraepithelial neoplasia, and angiogenesis have a critical role in the initiation and progression of prostate cancer. MicroRNA (miRNA) is endogenous, short, non-coding RNA molecules of almost 22 nucleotides play a role in regulating cellular processes and regulating several genes' expression. Through controlling endothelial migration, differentiation, death, and cell proliferation, miRNAs have a significant function in angiogenesis. A number of pathological and physiological processes, particularly prostate cancer's emergence, depend on the regulation of angiogenesis. Investigating the functions played with miRNAs in angiogenesis is crucial because it might result in the creation of novel prostate cancer therapies that entail regulating angiogenesis. The function of several miRNAs and its targeting genes engaged in cancer of the prostate angiogenesis will be reviewed in this review in light of the most recent developments. The potential clinical utility of miRNAs potentially a novel therapeutic targets will also be explored, as well as their capacity to control prostate cancer angiogenesis and the underlying mechanisms.

Exploring the tumor immune microenvironment in ovarian cancer: a way-out to the therapeutic roadmap

INTRODUCTION

Despite cancer treatment strides, mortality due to ovarian cancer remains high globally. While immunotherapy has proven effective in treating cancers with low cure rates, it has limitations. Growing evidence suggests that both tumoral and non-tumoral components of the tumor immune microenvironment (TIME) play a significant role in cancer growth. Therefore, developing novel and focused therapy for ovarian cancer is critical. Studies indicate that TIME is involved in developing ovarian cancer, particularly genome-, transcriptome-, and proteome-wide studies. As a result, TIME may present a prospective therapeutic target for ovarian cancer patients.

AREAS COVERED

We examined several TIME-targeting medicines and the connection between TIME and ovarian cancer. The key protagonists and events in the TIME and therapeutic strategies that explicitly target these events in ovarian cancer are discussed.

EXPERT OPINION

We highlighted various targeted therapies against TIME in ovarian cancer, including anti-angiogenesis therapies and immune checkpoint inhibitors. While these therapies are in their infancy, they have shown promise in controlling ovarian cancer progression. The use of 'omics' technology is helping in better understanding of TIME in ovarian cancer and potentially identifying new therapeutic targets. TIME-targeted strategies could account for an additional treatment strategy when treating ovarian cancer.

Characterization of the oral microbiota among middle-aged men with and without human papillomavirus infection

OBJECTIVES

To characterize the oral microbiota among middle-aged men and identify differences between men with a prevalent oral high-risk (oncogenic) HPV infection and those without.

MATERIALS AND METHODS

This was a case-control study nested within a prospective screening study for HPV-related cancers among middle-aged men. 16S rRNA sequencing was used to characterize the oral microbiota and the cobas HPV Test was used to detect presence of oral high-risk HPV types. We determined the overall composition of the oral microbiota and assessed differences in relative abundance of bacterial taxa as well as alpha and beta diversity among men with a prevalent oral high-risk HPV infection compared to men who were HPV-negative.

RESULTS

Among 13 high-risk HPV-positive and 30 HPV-negative men, we found significant differences in beta diversity but not alpha diversity. Fretibacterium, F0058, Kingella, Treponema, and Prevotella were more abundant among the high-risk HPV-positive men while Neisseria and Lactobacillus were more abundant among the HPV-negative men.

CONCLUSION

This study adds to the evidence that the oral microbiota varies according to oral HPV infection status and may be associated with the natural history of oral HPV infection.

CEBP-β and PLK1 as Potential Mediators of the Breast Cancer/Obesity Crosstalk: In Vitro and In Silico Analyses

Over the last two decades, obesity has reached pandemic proportions in several countries, and expanding evidence is showing its contribution to several types of malignancies, including breast cancer (BC). The conditioned medium (CM) from mature adipocytes contains a complex of secretes that may mimic the obesity condition in studies on BC cell lines conducted in vitro. Here, we report a transcriptomic analysis on MCF-7 BC cells exposed to adipocyte-derived CM and focus on the predictive functional relevance that CM-affected pathways/processes and related biomarkers (BMs) may have in BC response to obesity. CM was demonstrated to increase cell proliferation, motility and invasion as well as broadly alter the transcript profiles of MCF-7 cells by significantly modulating 364 genes. Bioinformatic functional analyses unraveled the presence of five highly relevant central hubs in the direct interaction networks (DIN), and Kaplan-Meier analysis sorted the CCAAT/enhancer binding protein beta (CEBP-β) and serine/threonine-protein kinase PLK1 (PLK1) as clinically significant biomarkers in BC. Indeed, CEBP-β and PLK1 negatively correlated with BC overall survival and were up-regulated by adipocyte-derived CM. In addition to their known involvement in cell proliferation and tumor progression, our work suggests them as a possible "deus ex machina" in BC response to fat tissue humoral products in obese women.

Insights into the Role of LncRNAs and miRNAs in Glioma Progression and Their Potential as Novel Therapeutic Targets

Accumulating evidence supports that both long non-coding and micro RNAs (lncRNAs and miRNAs) are implicated in glioma tumorigenesis and progression. Poor outcome of gliomas has been linked to late-stage diagnosis and mostly ineffectiveness of conventional treatment due to low knowledge about the early stage of gliomas, which are not possible to observe with conventional diagnostic approaches. The past few years witnessed a revolutionary advance in biotechnology and neuroscience with the understanding of tumor-related molecules, including non-coding RNAs that are involved in the angiogenesis and progression of glioma cells and thus are used as prognostic biomarkers as well as novel therapeutic targets. The emerging research on lncRNAs and miRNAs highlights their crucial role in glioma progression, offering new insights into the disease. These non-coding RNAs hold significant potential as novel therapeutic targets, paving the way for innovative treatment approaches against glioma. This review encompasses a comprehensive discussion about the role of lncRNAs and miRNAs in gene regulation that is responsible for the promotion or the inhibition of glioma progression and collects the existing links between these key cancer-related molecules.

Regulatory Functions of Hypoxia in Host-Parasite Interactions: A Focus on Enteric, Tissue, and Blood Protozoa

Body tissues are subjected to various oxygenic gradients and fluctuations and hence can become transiently hypoxic. Hypoxia-inducible factor (HIF) is the master transcriptional regulator of the cellular hypoxic response and is capable of modulating cellular metabolism, immune responses, epithelial barrier integrity, and local microbiota. Recent reports have characterized the hypoxic response to various infections. However, little is known about the role of HIF activation in the context of protozoan parasitic infections. Growing evidence suggests that tissue and blood protozoa can activate HIF and subsequent HIF target genes in the host, helping or hindering their pathogenicity. In the gut, enteric protozoa are adapted to steep longitudinal and radial oxygen gradients to complete their life cycle, yet the role of HIF during these protozoan infections remains unclear. This review focuses on the hypoxic response to protozoa and its role in the pathophysiology of parasitic infections. We also discuss how hypoxia modulates host immune responses in the context of protozoan infections.

Plasticity of cancer invasion and energy metabolism

Energy deprivation is a frequent adverse event in tumors that is caused by mutations, malperfusion, hypoxia, and nutrition deficit. The resulting bioenergetic stress leads to signaling and metabolic adaptation responses in tumor cells, secures survival, and adjusts migration activity. The kinetic responses of cancer cells to energy deficit were recently identified, including a switch of invasive cancer cells to energy-conservative amoeboid migration and an enhanced capability for distant metastasis. We review the energy programs employed by different cancer invasion modes including collective, mesenchymal, and amoeboid migration, as well as their interconversion in response to energy deprivation, and we discuss the consequences for metastatic escape. Understanding the energy requirements of amoeboid and other dissemination strategies offers rationales for improving therapeutic targeting of metastatic cancer progression.

Low-Cost, High-Pressure-Synthesized Oxygen-Entrapping Materials to Improve Treatment of Solid Tumors

Tumor hypoxia drives resistance to many cancer therapies, including radiotherapy and chemotherapy. Methods that increase tumor oxygen pressures, such as hyperbaric oxygen therapy and microbubble infusion, are utilized to improve the responses to current standard-of-care therapies. However, key obstacles remain, in particular delivery of oxygen at the appropriate dose and with optimal pharmacokinetics. Toward overcoming these hurdles, gas-entrapping materials (GeMs) that are capable of tunable oxygen release are formulated. It is shown that injection or implantation of these materials into tumors can mitigate tumor hypoxia by delivering oxygen locally and that these GeMs enhance responsiveness to radiation and chemotherapy in multiple tumor types. This paper also demonstrates, by comparing an oxygen (O2 )-GeM to a sham GeM, that the former generates an antitumorigenic and immunogenic tumor microenvironment in malignant peripheral nerve sheath tumors. Collectively the results indicate that the use of O2 -GeMs is promising as an adjunctive strategy for the treatment of solid tumors.

Allantopyrone A interferes with the degradation of hypoxia-inducible factor 1α protein by reducing proteasome activity in human fibrosarcoma HT-1080 cells

Allantopyrone A is an α-pyrone metabolite that was originally isolated from the endophytic fungus Allantophomopsis lycopodina KS-97. We previously demonstrated that allantopyrone A exhibits anti-cancer, anti-inflammatory, and neuroprotective activities. In the present study, we showed that allantopyrone A up-regulated the protein expression of hypoxia-inducible factor (HIF)-1α in human fibrosarcoma HT-1080 cells. It also up-regulated the mRNA expression of BNIP3 and ENO1, but not other HIF target genes or HIF1A. Allantopyrone A did not inhibit the prolyl hydroxylation of HIF-1α, but enhanced the ubiquitination of cellular proteins. Consistent with this result, chymotrypsin-like and trypsin-like proteasome activities were reduced, but not completely inactivated by allantopyrone A. Allantopyrone A decreased the amount of proteasome catalytic subunits. Therefore, the present results showed that allantopyrone A interfered with the degradation of HIF-1α protein by reducing proteasome activity in human fibrosarcoma HT-1080 cells.

A novel nomogram predicting the early recurrence of hepatocellular carcinoma patients after R0 resection

Background

Early tumor recurrence is one of the most significant poor prognostic factors for patients with HCC after R0 resection. The aim of this study is to identify risk factors of early recurrence, in addition, to develop a nomogram model predicting early recurrence of HCC patients.

Methods

A total of 481 HCC patients after R0 resection were enrolled and divided into a training cohort (n = 337) and a validation cohort (n = 144). Risk factors for early recurrence were determined based on Cox regression analysis in the training cohort. A nomogram incorporating independent risk predictors was established and validated.

Results

Early recurrence occurred in 37.8% of the 481 patients who underwent curative liver resection of HCC. AFP ≥ 400 ng/mL (HR: 1.662; P = 0.008), VEGF-A among 127.8 to 240.3 pg/mL (HR: 1.781, P = 0.012), VEGF-A > 240.3 pg/mL (HR: 2.552, P < 0.001), M1 subgroup of MVI (HR: 2.221, P = 0.002), M2 subgroup of MVI (HR: 3.120, P < 0.001), intratumor necrosis (HR: 1.666, P = 0.011), surgical margin among 5.0 to 10.0 mm (HR: 1.601, P = 0.043) and surgical margin < 5.0 mm (HR: 1.790, P = 0.012) were found to be independent risk factors for recurrence-free survival in the training cohort and were used for constructing the nomogram. The nomogram indicated good predictive performance with an AUC of 0.781 (95% CI: 0.729-0.832) and 0.808 (95% CI: 0.731-0.886) in the training and validation cohorts, respectively.

Conclusions

Elevated serum concentrations of AFP and VEGF-A, microvascular invasion, intratumor necrosis, surgical margin were independent risk factors of early intrahepatic recurrence. A reliable nomogram model which incorporated blood biomarkers and pathological variables was established and validated. The nomogram achieved desirable effectiveness in predicting early recurrence in HCC patients.

A JAK tyrosine kinase and pseudokinase Co-inhibition strategy combines enhanced potency and on-demand activation

Janus tyrosine kinase (JAK) inhibitors have been on the market for several years, but their use is limited by drug resistance and intolerable side effects. Herein, we propose a novel strategy of JAK tyrosine kinase (TK) and pseudokinase (PK) domain co-inhibition system to consolidate robust JAK inhibition and on-demand activation. A photoexcited prodrug PAT-SIL-TG-1&AT exhibits the synergy effects of TK-PK co-inhibition and enable the spatiotemporal control of JAK2 signaling. The hypoxia-activated prodrug HAT-SIL-TG-1&AT significantly inhibited HEL cells proliferation and downregulated phosphorylated STAT3/5 under hypoxic conditions. Importantly, HAT-SIL-TG-1&AT showed synergistic antitumor effects and selectively inhibited the JAK-STAT signaling in tumor tissues in vivo. This work demonstrates a viable solution to achieve superior JAK2 inhibition, and provides an inspiration for other kinases containing PK domain.

Key events in cancer: Dysregulation of SREBPs

Lipid metabolism reprogramming is an important hallmark of tumor progression. Cancer cells require high levels of lipid synthesis and uptake not only to support their continued replication, invasion, metastasis, and survival but also to participate in the formation of biological membranes and signaling molecules. Sterol regulatory element binding proteins (SREBPs) are core transcription factors that control lipid metabolism and the expression of important genes for lipid synthesis and uptake. A growing number of studies have shown that SREBPs are significantly upregulated in human cancers and serve as intermediaries providing a mechanistic link between lipid metabolism reprogramming and malignancy. Different subcellular localizations, including endoplasmic reticulum, Golgi, and nucleus, play an indispensable role in regulating the cleavage maturation and activity of SREBPs. In this review, we focus on the relationship between aberrant regulation of SREBPs activity in three organelles and tumor progression. Because blocking the regulation of lipid synthesis by SREBPs has gradually become an important part of tumor therapy, this review also summarizes and analyzes several current mainstream strategies.

Involvement of redox signalling in tumour cell dormancy and metastasis

Decades of research on oncogene-driven carcinogenesis and gene-expression regulatory networks only started to unveil the complexity of tumour cellular and molecular biology. This knowledge has been successfully implemented in the clinical practice to treat primary tumours. In contrast, much less progress has been made in the development of new therapies against metastasis, which are the main cause of cancer-related deaths. More recently, the role of epigenetic and microenviromental factors has been shown to play a key role in tumour progression. Free radicals are known to communicate the intracellular and extracellular compartments, acting as second messengers and exerting a decisive modulatory effect on tumour cell signalling. Depending on the cellular and molecular context, as well as the intracellular concentration of free radicals and the activation status of the antioxidant system of the cell, the signalling equilibrium can be tilted either towards tumour cell survival and progression or cell death. In this regard, recent advances in tumour cell biology and metastasis indicate that redox signalling is at the base of many cell-intrinsic and microenvironmental mechanisms that control disseminated tumour cell fate and metastasis. In this manuscript, we will review the current knowledge about redox signalling along the different phases of the metastatic cascade, including tumour cell dormancy, making emphasis on metabolism and the establishment of supportive microenvironmental connections, from a redox perspective.

In situ forming oxygen/ROS-responsive niche-like hydrogel enabling gelation-triggered chemotherapy and inhibition of metastasis

Though the development of the diverse hypoxia-activated prodrugs (HAPs) has made great progresses in the last several decades, current cancer therapy based on HAPs still suffers many obstacles, e.g., poor therapeutic outcome owing to hard deep reaching to hypoxic region, and the occurrence of metastasis due to hypoxia. Inspired by engineered niches, a novel functional chitosan polymer (CS-FTP) is synthesized for construction of a hydrogel-based bio-niche (CS-FTP-gel) in aiming at remodeling tumor hypoxic microenvironment. The CS-FTP polymers are crosslinked to form a niche-like hydrogel via enzyme-mediated oxygen-consumable dimerization after injected into tumor, in which a HAP (i.e., AQ4N) could be physically encapsulated, resulting in enhanced tumor hypoxia to facilitate AQ4N-AQ4 toxic transformation for maximizing efficacy of chemotherapy. Furthermore, Pazopanib (PAZ) conjugated onto the CS backbone via ROS-sensitive linker undergoes a stimuli-responsive release behavior to promote antiangiogenesis for tumor starvation, eventually contributing to the inhibition of lung metastasis and synergistic action with AQ4N-based chemotherapy for an orthotopic 4T1 breast tumor model. This study provides a promising strategy for hypoxia-based chemotherapy and demonstrates an encouraging clinical potential for multifunctional hydrogel applicable for antitumor treatment.

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CS-FTP shows enzyme-mediated hypoxia-inducible gelation and reactive oxygen species (ROS)-responsive drug release.

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CS-FTP gel formed intratumorally can be used as a bio-niche to enhance tumor hypoxic microenvironment.

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In vivo PET/CT directly monitors the tumor hypoxia changes and confirm the ability of CS-FTP to enhance tumor hypoxia.

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Oxygen-consumable gelation of ROS-responsive CS-FTP triggers chemotherapy and starvation therapy for antimetastasis.

Cancer cell-derived CD69 induced under lipid and oxygen starvation promotes ovarian cancer progression through fibronectin

Cancer tissues generally have molecular oxygen and serum component deficiencies because of poor vascularization. Recently, we revealed that ICAM1 is strongly activated through lipophagy in ovarian clear cell carcinoma (CCC) cells in response to starvation of long-chain fatty acids and oxygen and confers resistance to apoptosis caused by these harsh conditions. CD69 is a glycoprotein that is synthesized in immune cells and is associated with their activation through cellular signaling pathways. However, the expression and function of CD69 in nonhematological cells is unclear. Here, we report that CD69 is induced in CCC cells as in ICAM1. Mass spectrometry analysis of phosphorylated peptides followed by pathway analysis revealed that CD69 augments CCC cell binding to fibronectin (FN) in association with the phosphorylation of multiple cellular signaling molecules including the focal adhesion pathway. Furthermore, CD69 synthesized in CCC cells could facilitate cell survival because the CD69-FN axis can induce epithelial-mesenchymal transition. Experiments with surgically removed tumor samples revealed that CD69 is predominantly expressed in CCC tumor cells compared with other histological subtypes of epithelial ovarian cancer. Overall, our data suggest that cancer cell-derived CD69 can contribute to CCC progression through FN.

Correlation between hypoxia and HGF/c-MET expression in the management of pancreatic cancer

Pancreatic cancer (PC) is very deadly and difficult to treat. The presence of hypoxia has been shown to increase the probability of cancer developing and spreading. Pancreatic ductal adenocarcinoma (PDAC/PC) has traditionally viewed a highly lethal form of cancer due to its high occurrence of early metastases. Desmoplasia/stroma is often thick and collagenous, with pancreatic stellate cells as the primary source (PSCs). Cancer cells and other stromal cells interact with PSCs, promoting disease development. The hepatocyte growth factor (HGF)/c-MET pathway have been proposed as a growth factor mechanism mediating this interaction. Human growth factor (HGF) is secreted by pancreatic stellate cells (PSCs), and its receptor, c-MET, is generated by pancreatic cancer cells and endothelial cells. Hypoxia is frequent in malignant tumors, particularly pancreatic (PC). Hypoxia results from limitless tumor development and promotes survival, progression, and invasion. Hypoxic is becoming a critical driver and therapeutic target of pancreatic cancer as its hypoxia microenvironment is defined. Recent breakthroughs in cancer biology show that hypoxia promotes tumor proliferation, aggressiveness, and therapeutic resistance. Hypoxia-inducible factors (HIFs) stabilize hypoxia signaling. Hypoxia cMet is a key component of pancreatic tumor microenvironments, which also have a fibrotic response, that hypoxia, promotes and modulates. c-Met is a tyrosine-protein kinase. As describe it simply, the MET gene in humans' codes for a protein called hepatocyte growth factor receptor (HGFR). Most cancerous tumors and pancreatic cancer in particular, suffer from a lack of oxygen (PC). Due to unrestrained tumor development, hypoxia develops, actively contributing to tumor survival, progression, and invasion. As the processes by which hypoxia signaling promotes invasion and metastasis become clear, c-MET has emerged as an important determinant of pancreatic cancer malignancy and a potential pharmacological target. This manuscript provides the most current findings on the role of hypoxia and HGF/c-MET expression in the treatment of pancreatic cancer.

miR-34a and IRE1A/XBP-1(S) Form a Double-Negative Feedback Loop to Regulate Hypoxia-Induced EMT, Metastasis, Chemo-Resistance and Autophagy

Tumor-associated hypoxia, i.e., decreased availability of oxygen, results in a poor clinical outcome since it promotes EMT, metastasis, and chemotherapy-resistance. We have previously identified p53 and its target miR-34a, as critical determinants of the effect of hypoxia on colorectal cancer (CRC). Here, we aimed to characterize mechanisms that contribute to the selective advantage of cells with loss of p53/miR-34a function in a hypoxic environment. Using in silico prediction, we identified XBP-1 and IRE1A as potential miR-34a targets. IRE1A and XBP-1 are central components of the unfolded protein response that is activated by ER stress, which is also induced in tumor cells as a response to harsh conditions surrounding tumors such as hypoxia and a limited supply of nutrients. Here we characterized the XBP-1(S) transcription factor and its regulator IRE1A as direct, conserved miR-34a targets in CRC cells. After hypoxia and DNA damage, IRE1A and XBP-1 were repressed by p53 in a miR-34a-dependent manner, whereas p53-deficient cells showed induction of IRE1A and XBP-1(S). Furthermore, miR-34a expression was directly suppressed by XBP-1(S). In p53-deficient CRC cells, hypoxia-induced EMT, migration, invasion, metastases formation, and resistance to 5-FU were dependent on IRE1A/XBP-1(S) activation. Hypoxia-induced autophagy was identified as an XBP-1(S)-dependent mediator of 5-FU resistance and was reversed by ectopic miR-34a expression. The HIF1A/IRE1A/XBP-1(S)/p53/miR-34a feedback loop described here represents a central regulator of the response to hypoxia and ER stress that maintains cellular homeostasis. In tumors, the inactivation of p53 and miR-34a may result in IRE1A/XPB-1(S)-mediated EMT and autophagy, which ultimately promotes metastasis and chemoresistance.

Effective oxygen metabolism-based prognostic signature for colorectal cancer

Backgroud

Oxygen metabolism is an important factor affecting the development of tumors, but its roles and clinical value in Colorectal cancer are not clear. We developed an oxygen metabolism (OM) based prognostic risk model for colorectal cancer and explored the role of OM genes in cancer.

Methods

Gene expression and clinical data obtained from The Cancer Genome Atlas, Clinical Proteomic Tumor Analysis Consortium databases were consider as discovery and validation cohort, respectively. The prognostic model based on differently expressed OM genes between tumor and GTEx normal colorectal tissues were constructed in discovery cohort and validated in validation cohort. The Cox proportional hazards analysis was used to test clinical independent. Upstream and downstream regulatory relationships and interaction molecules are used to clarify the roles of prognostic OM genes in colorectal cancer.

Results

A total of 72 common differently expressed OM genes were detected in the discovery and validation set. A five-OM gene prognostic model including LRT2, ATP6V0E2, ODC1, SEL1L3 and VDR was established and validated. Risk score determined by the model was an independent prognostic according to routine clinical factors. Besides, the role of prognostic OM genes involves transcriptional regulation of MYC and STAT3, and downstream cell stress and inflammatory response pathways.

Conclusions

We developed a five-OM gene prognostic model and study the unique roles of oxygen metabolism in of colorectal cancer.

HIF2α activation and mitochondrial deficit due to iron chelation cause retinal atrophy

Iron accumulation causes cell death and disrupts tissue functions, which necessitates chelation therapy to reduce iron overload. However, clinical utilization of deferoxamine (DFO), an iron chelator, has been documented to give rise to systemic adverse effects, including ocular toxicity. This study provided the pathogenic and molecular basis for DFO-related retinopathy and identified retinal pigment epithelium (RPE) as the target tissue in DFO-related retinopathy. Our modeling demonstrated the susceptibility of RPE to DFO compared with the neuroretina. Intriguingly, we established upregulation of hypoxia inducible factor (HIF) 2α and mitochondrial deficit as the most prominent pathogenesis underlying the RPE atrophy. Moreover, suppressing hyperactivity of HIF2α and preserving mitochondrial dysfunction by α-ketoglutarate (AKG) protects the RPE against lesions both in vitro and in vivo. This supported our observation that AKG supplementation alleviates visual impairment in a patient undergoing DFO-chelation therapy. Overall, our study established a significant role of iron deficiency in initiating DFO-related RPE atrophy. Inhibiting HIF2α and rescuing mitochondrial function by AKG protect RPE cells and can potentially ameliorate patients' visual function.

Profiles of Expression of SAV1 in Normoxia or Hypoxia Microenviroment are Associated with Breast Cancer Prognosis

BACKGROUND

In breast cancer (BC), hypoxia is associated with poor prognosis. Protein Salvador homolog 1 (SAV1) acts as a tumor suppressor and is downregulated in the cancer cells. However, there is limited data on the expression profile of SAV1 and its importance in BC. It has not been studied to evaluate this phenomenon in a hypoxic microenvironment yet.

AIM

This study aimed to investigate SAV1 expression profiles under normoxia and hypoxia, and the potential of SAV1 in BC prognosis.

METHODS

Gene and protein expression analyses were performed using Real-Time quantitative PCR (RT-qPCR) and immunocytochemistry (ICC), respectively, and in silico analyses were performed using The Cancer Genome Atlas (TCGA). The survival curves were constructed using KMplotter.

RESULTS

SAV1 expression was lower in BC samples and tumor cell lines than in normal samples. The SAV1 mRNA levels were reduced in hypoxic estrogen receptor positive (ER⁺) tumors, which were associated with a lower survival probability as compared to normoxic ER⁺ tumors. Furthermore, lower levels of SAV1 were found in advanced cancer stage samples, which are associated with worse survival curves and can be a risk factor for BC.

CONCLUSIONS

These data suggest a potential prognostic role of SAV1 in BC, with lower expressions associated with worse prognosis.

Tumor micronecrosis predicts poor prognosis of patients with hepatocellular carcinoma after liver transplantation

BACKGROUND

Tumor micronecrosis is a histopathological feature predicting poor prognosis in patients with hepatocellular carcinoma (HCC) who underwent liver resection. However, the role of tumor micronecrosis in liver transplantation remains unclear.

METHODS

We retrospectively reviewed patients with HCC who underwent liver transplantation between January 2015 and December 2021 at our center. We then classified them into micronecrosis(-) and micronecrosis(+) groups and compared their recurrence-free survival (RFS) and overall survival (OS). We identified independent prognostic factors using Cox regression analysis and calculated the area under the receiver operating characteristic curve (AUC) to evaluate the predictive value of RFS for patients with HCC after liver transplantation.

RESULTS

A total of 370 cases with evaluable histological sections were included. Patients of the micronecrosis(+) group had a significantly shorter RFS than those of the micronecrosis(-) group (P = 0.037). Shorter RFS and OS were observed in micronecrosis(+) patients without bridging treatments before liver transplantation (P = 0.002 and P = 0.007), while no differences were detected in those with preoperative antitumor therapies that could cause iatrogenic tumor necrosis. Tumor micronecrosis improved the AUC of Milan criteria (0.77-0.79), the model for end-stage liver disease score (0.70-0.76), and serum alpha-fetoprotein (0.63-0.71) for the prediction of prognosis after liver transplantation.

CONCLUSION

Patients with HCC with tumor micronecrosis suffer from a worse prognosis than those without this feature. Tumor micronecrosis can help predict RFS after liver transplantation. Therefore, patients with HCC with tumor micronecrosis should be treated with adjuvant therapy and closely followed after liver transplantation.

CLINICAL TRIALS REGISTRATION

Not Applicable.

MIF promotes cell invasion by the LRP1-uPAR interaction in pancreatic cancer cells

Introduction

Pancreatic ductal adenocarcinoma (PDAC) is characterized by high aggressiveness and a hypoxic tumour microenvironment. Macrophage migration inhibitory factor (MIF) is a hypoxia-related pleiotropic cytokine that plays important roles in cancer. However, its role in PDAC progression has not been fully elucidated.

Methods

The clinical significance of MIF and hypoxia inducible factor 1 subunit alpha (HIF1A) in PDAC was analysed using immunohistochemical staining on PDAC tissues and data from KM-Plotter database. Spatial distribution of MIF and HIF1A gene expression was visualized by spatial transcriptomics in PDAC cell xenografts. To monitor the role of MIF in PDAC cell malignancy, immunostaining, lentivirus shRNA, migration assays, flow cytometry, transcriptomics and in vivo tumorigenicity were performed.

Results

The spatial distribution of MIF and HIF1A was highly correlated and that high MIF expression was associated with poor prognosis of PDAC patients. MIF knockdown impaired cell invasion, with a decrease in the expression of urokinase-type plasminogen activator receptor (uPAR). Although PLAUR transcript was not reduced, a uPAR endocytic receptor, low-density lipoprotein receptor-related protein 1 (LRP1), was upregulated at both the mRNA and protein levels after MIF knockdown. The LRP1 antagonist RAP restored uPAR expression and invasiveness. MIF attenuated the nuclear translocation of p53, a transcriptional regulator of LRP1. Furthermore, MIF downregulation blunted the growth of PDAC cell xenografts and inhibited cell proliferation under normoxia and hypoxia. Transcriptome analysis also provided evidence for the role of MIF in cancer-associated pathways.

Discussion

We demonstrate a novel link between the two pro-invasive agents MIF and uPAR and explain how MIF increases PDAC cell invasion capability. This finding provides a basis for therapeutic intervention of MIF in PDAC progression.

Effects of the exercise-inducible myokine irisin on proliferation and malignant properties of ovarian cancer cells through the HIF-1 α signaling pathway

Exercise has been shown to be associated with reduced risk and improving outcomes of several types of cancers. Irisin -a novel exercise-related myokine- has been proposed to exert beneficial effects in metabolic disorders including cancer. No previous studies have investigated whether irisin may regulate malignant characteristics of ovarian cancer cell lines. In the present study, we aimed to explore the effect of irisin on viability and proliferation of ovarian cancer cells which was examined by MTT assay. Then, we evaluated the migratory and invasive abilities of the cells via transwell assays. Moreover, the percentage of apoptosis induction was determined by flow cytometry. Furthermore, the mRNA expression level of genes related to the aerobic respiration (HIF-1α, c-Myc, LDHA, PDK1 and VEGF) was detected by real-time PCR. Our data revealed that irisin treatment significantly attenuated the proliferation, migration and invasion of ovarian cancer cells. Additionally, irisin induced apoptosis in ovarian cancer cells. We also observed that irisin regulated the expression of genes involved in aerobic respiration of ovarian cancer cells. Our results indicated that irisin may play a crucial role in inhibition of cell growth and malignant characteristics of ovarian cancer. These findings may open up avenues for future studies to identify the further therapeutic use of irisin in ovarian cancer management.

The Role of Hypoxia in Brain Tumor Immune Responses

Oxygen is a vital component of living cells. Low levels of oxygen in body tissues, known as hypoxia, can affect multiple cellular functions across a variety of cell types and are a hallmark of brain tumors. In the tumor microenvironment, abnormal vasculature and enhanced oxygen consumption by tumor cells induce broad hypoxia that affects not only tumor cell characteristics but also the antitumor immune system. Although some immune reactions require hypoxia, hypoxia generally negatively affects immunity. Hypoxia induces tumor cell invasion, cellular adaptations to hypoxia, and tumor cell radioresistance. In addition, hypoxia limits the efficacy of immunotherapy and hinders antitumor responses. Therefore, understanding the role of hypoxia in the brain tumor, which usually does not respond to immunotherapy alone is important for the development of effective anti-tumor therapies. In this review, we discuss recent evidence supporting the role of hypoxia in the context of brain tumors.

Importance of lactate dehydrogenase (LDH) and monocarboxylate transporters (MCTs) in cancer cells

Background

In most regions, cancer ranks the second most frequent cause of death following cardiovascular disorders.

Aim

In this article, we review the various aspects of glycolysis with a focus on types of MCTs and the importance of lactate in cancer cells.

Results and Discussion

Metabolic changes are one of the first and most important alterations in cancer cells. Cancer cells use different pathways to survive, energy generation, growth, and proliferation compared to normal cells. The increase in glycolysis, which produces substances such as lactate and pyruvate, has an important role in metastases and invasion of cancer cells. Two important cellular proteins that play a role in the production and transport of lactate include lactate dehydrogenase and monocarboxylate transporters (MCTs). These molecules by their various isoforms and different tissue distribution help to escape the immune system and expansion of cancer cells under different conditions.

Updated perspective of EPAS1 and the role in pulmonary hypertension

Pulmonary hypertension (PH) is a group of syndromes characterized by irreversible vascular remodeling and persistent elevation of pulmonary vascular resistance and pressure, leading to ultimately right heart failure and even death. Current therapeutic strategies mainly focus on symptoms alleviation by stimulating pulmonary vessel dilation. Unfortunately, the mechanism and interventional management of vascular remodeling are still yet unrevealed. Hypoxia plays a central role in the pathogenesis of PH and numerous studies have shown the relationship between PH and hypoxia-inducible factors family. EPAS1, known as hypoxia-inducible factor-2 alpha (HIF-2α), functions as a transcription factor participating in various cellular pathways. However, the detailed mechanism of EPAS1 has not been fully and systematically described. This article exhibited a comprehensive summary of EPAS1 including the molecular structure, biological function and regulatory network in PH and other relevant cardiovascular diseases, and furthermore, provided theoretical reference for the potential novel target for future PH intervention.

Bioinformatics Analysis Identifies EPAS1 as a Novel Prognostic Marker Correlated with Immune Infiltration in Acute Myeloid Leukemia

EPAS1 plays an important role in the development and progression of multiple tumor types by interacting with a series of other molecules. However, the prognostic and diagnostic values of EPAS1 in acute myeloid leukemia (AML) remain unknown. Here, we systematically explored and clarified the potential functions of EPAS1 in AML using data from Xena Browser and TCGA database. The expression of EPAS1 was significantly lower in AML patients than that in healthy people. The GO, KEGG, GSEA, and GSVA were performed to explore the potential functions and signaling pathways. The survival analysis was conducted using Cox regression analysis and the Kaplan-Meier method. Immune cell infiltration was evaluated via single-sample GSEA (ssGSEA). The results of enrichment analyses suggested that low-EPAS1 expression was related to the initiation, development, and prognosis of AML. The immune microenvironment landscape in AML was described by ssGSEA. ROC analysis of EPAS1 showed high discrimination ability between AML patients and healthy people. Kaplan-Meier method indicated that low-EPAS1 expression correlated significantly with a poor overall survival. Multivariate Cox regression analysis revealed that both age and EPAS1 expression were independent prognostic factors in AML patients. Furthermore, the nomogram based on these two variables performed well in discrimination and calibration. In summary, our study may provide new insights into the molecular mechanisms underlying AML and demonstrate the diagnostic and prognostic value of EPAS1 in AML for the first time.

CRAC and SK Channels: Their Molecular Mechanisms Associated with Cancer Cell Development

Cancer represents a major health burden worldwide. Several molecular targets have been discovered alongside treatments with positive clinical outcomes. However, the reoccurrence of cancer due to therapy resistance remains the primary cause of mortality. Endeavors in pinpointing new markers as molecular targets in cancer therapy are highly desired. The significance of the co-regulation of Ca2+-permeating and Ca2+-regulated ion channels in cancer cell development, proliferation, and migration make them promising molecular targets in cancer therapy. In particular, the co-regulation of the Orai1 and SK3 channels has been well-studied in breast and colon cancer cells, where it finally leads to an invasion-metastasis cascade. Nevertheless, many questions remain unanswered, such as which key molecular components determine and regulate their interplay. To provide a solid foundation for a better understanding of this ion channel co-regulation in cancer, we first shed light on the physiological role of Ca2+ and how this ion is linked to carcinogenesis. Then, we highlight the structure/function relationship of Orai1 and SK3, both individually and in concert, their role in the development of different types of cancer, and aspects that are not yet known in this context.

Hypoxia-immune-related microenvironment prognostic signature for osteosarcoma

Introduction: Increasing evidences have shown that hypoxia and the immune microenvironment play vital roles in the development of osteosarcoma. However, reliable gene signatures based on the combination of hypoxia and the immune status for prognostic prediction of osteosarcoma have so far not been identified. Methods: The individual hypoxia and immune status of osteosarcoma patients were identified with transcriptomic profiles of a training cohort from the TARGET database using ssGSEA and ESTIMATE algorithms, respectively. Lasso regression and stepwise Cox regression were performed to develop a hypoxia-immune-based gene signature. An independent cohort from the GEO database was used for external validation. Finally, a nomogram was constructed based on the gene signature and clinical features to improve the risk stratification and to quantify the risk assessment for individual patients. Results: Hypoxia and the immune status were significantly associated with the prognosis of osteosarcoma patients. Seven hypoxia- and immune-related genes (BNIP3, SLC38A5, SLC5A3, CKMT2, S100A3, CXCL11 and PGM1) were identified to be involved in our prognostic signature. In the training cohort, the prognostic signature discriminated high-risk patients with osteosarcoma. The hypoxia-immune-based gene signature proved to be a stable and predictive method as determined in different datasets and subgroups of patients. Furthermore, a nomogram based on the prognostic signature was generated to optimize the risk stratification and to quantify the risk assessment. Similar results were validated in an independent GEO cohort, confirming the stability and reliability of the prognostic signature. Conclusion: The hypoxia-immune-based prognostic signature might contribute to the optimization of risk stratification for survival and personalized management of osteosarcoma patients.

The evaluation expression of non-coding RNAs in response to HSV-G47∆ oncolytic virus infection in glioblastoma multiforme cancer stem cells

Glioblastoma multiforme is the most aggressive astrocytes brain tumor. Glioblastoma cancer stem cells and hypoxia conditions are well-known major obstacles in treatment. Studies have revealed that non-coding RNAs serve a critical role in glioblastoma progression, invasion, and resistance to chemo-radiotherapy. The present study examined the expression levels of microRNAs (in normoxic condition) and long non-coding RNAs (in normoxic and hypoxic conditions) in glioblastoma stem cells treated with the HSV-G47∆. The expression levels of 43 miRNAs and 8 lncRNAs isolated from U251-GBM-CSCs were analyzed using a miRCURY LNA custom PCR array and a quantitative PCR assay, respectively. The data revealed that out of 43 miRNAs that only were checked in normoxic condition, the only 8 miRNAs, including miR-7-1, miR-let-7b, miR-130a, miR-137, miR-200b, miR-221, miR-222, and miR-874, were markedly upregulated. The expression levels of lncRNAs, including LEF1 antisense RNA 1 (LEF1-AS1), metastasis-associated lung adenocarcinoma transcript 1 (MALAT1), long intergenic non-protein coding RNA 470 (LINC00470), tumor suppressor candidate 7 (TUSC7), HOX transcript antisense RNA (HOTAIR), nuclear paraspeckle assembly transcript 1 (NEAT1), and X inactive specific transcript (XIST), were markedly downregulated in the hypoxic microenvironment, and H19-imprinted maternally expressed transcript (H19) was not observed to be dysregulated in this environment. Under normoxic conditions, LEF1-AS1, MALAT1, LINC00470, H19, HOTAIR, NEAT1, and XIST were downregulated and TUSC7 was not targeted by HSV-G47∆. Overall, the present data shows HSVG47Δ treatment deregulates non-coding RNA expression in GBM-CSC tumor microenvironments.