ATP5A1 and ATP5B are highly expressed in glioblastoma tumor cells and endothelial cells of microvascular proliferation

BRG1 promotes liver cancer cell proliferation and metastasis by enhancing mitochondrial function and ATP5A1 synthesis through TOMM40

Hepatocellular carcinoma (HCC) is one of the most lethal malignant tumors worldwide. Brahma-related gene 1 (BRG1), as a catalytic ATPase, is a major regulator of gene expression and is known to mutate and overexpress in HCC. The purpose of this study was to investigate the mechanism of action of BRG1 in HCC cells. In our study, BRG1 was silenced or overexpressed in human HCC cell lines. Transwell and wound healing assays were used to analyze cell invasiveness and migration. Mitochondrial membrane potential (MMP) and mitochondrial permeability transition pore (mPTP) detection were used to evaluate mitochondrial function in HCC cells. Colony formation and cell apoptosis assays were used to evaluate the effect of BRG1/TOMM40/ATP5A1 on HCC cell proliferation and apoptosis/death. Immunocytochemistry (ICC), immunofluorescence (IF) staining and western blot analysis were used to determine the effect of BRG1 on TOMM40, ATP5A1 pathway in HCC cells. As a result, knockdown of BRG1 significantly inhibited cell proliferation and invasion, promoted apoptosis in HCC cells, whereas BRG1 overexpression reversed the above effects. Overexpression of BRG1 can up-regulate MMP level, inhibit mPTP opening and activate TOMM40, ATP5A1 expression. Our results suggest that BRG1, as an oncogene, promotes HCC progression by regulating TOMM40 affecting mitochondrial function and ATP5A1 synthesis. Targeting BRG1 may represent a new and effective way to prevent HCC development.

Exosomes: Their role in the diagnosis, progression, metastasis, and treatment of glioblastoma

Exosomes are crucial for the growth and spread of glioblastomas, an aggressive form of brain cancer. These tiny vesicles play a crucial role in the activation of signaling pathways and intercellular communication. They can also transfer a variety of biomolecules such as proteins, lipids and nucleic acids from donor to recipient cells. Exosomes can influence the immune response by regulating the activity of immune cells, and they are crucial for the growth and metastasis of glioblastoma cells. In addition, exosomes contribute to drug resistance during treatment, which is a major obstacle in the treatment of glioblastoma. By studying them, the diagnosis and prognosis of glioblastoma can be improved. Due to their high biocompatibility and lack of toxicity, they have become an attractive option for drug delivery. The development of exosomes as carriers of specific therapeutic agents could overcome some of the obstacles to effective treatment of glioblastoma. In this review, we address the potential of exosomes for the treatment of glioblastoma and show how they can be modified for this purpose.

The downregulation of NSUN5 may contribute to preeclampsia

Preeclampsia (PE) is a complication of pregnancy characterized by the new onset of hypertension after 20 weeks of gestation. The incidence of PE is steadily rising, posing a significant threat to the lives of both the pregnant woman and the fetus. Most studies on PE pathogenesis currently focus on the placenta, but maternal decidualization forms the foundation for placental growth and development. Recent studies have shown that impaired decidualization is also a cause of PE. Decidualization is a process where endometrial stromal cells gradually transform into secretory decidual cells during early pregnancy. While NSUN5 encodes a member of a conserved family of proteins, its role in pregnancy remains unknown. In this study, we conducted experiments and observed a significant downregulation of NSUN5 expression in severe preeclampsia decidual tissues compared to those of normal pregnant women. When inducing decidualization in vitro, we found an increase in NSUN5 expression. However, when we used siRNA to knockdown NSUN5 expression, the process of decidualization was prevented. Moreover, we observed a decrease in ATP content during both cell decidualization and after knockdown of NSUN5. Finally, through immunoprecipitation combined with mass spectrometry, we discovered that the protein ATP5B interacts with NSUN5. Furthermore, after knocking down ATP5B using siRNA, we observed impaired decidualization. Moreover, transfection with siRNA to suppress NSUN5 resulted in a decrease in ATP5B expression. These significant findings provide strong evidence that NSUN5 plays a crucial role in decidualization and is closely associated with the development of PE through its interaction with ATP5B.

Identification of differentially expressed genes and metabolism signaling pathway in the spleen of broilers supplemented with probiotic Bacillus spp

Probiotics are essential in the body's nutrients, improving the ratio of meat to meat, immune response, and preventing diseases. In this study, RNA-sequencing (RNA-seq) was used to identify the differentially expressed genes (DEGs), enriched related pathways, and Gene Ontology (GO) terms among blank negative control (NC), supplemented with Bacillus spp. (BS) and commercial probiotic (PC) groups after a 42-day fed supplementation. The results showed that 2005, 1356, and 2189 DEGs were significantly altered in BS vs. NC, PC vs NC, and BS vs PC groups, respectively. On the other hand, 9 DEGs were further validated by qRT-PCR, indicating that the qRT-PCR and RNA-Seq results were more consistent. Therefore, the GO and Kyoto Encyclopedia of Genes and Genomes (KEGG) analyses of DEGs showed that the DEGs were mainly enriched to metabolism signalling pathways (alpha-linolenic acid metabolism, linoleic acid metabolism, tryptophan metabolism, tyrosine metabolism, ether lipid metabolism, and metabolic pathway, etc) and immune response pathways (cytokine-cytokine receptor interaction, MAPK signalling pathway, and intestinal immune network for IgA production, neuroactive ligand-receptor interaction etc). These results will provide a better understanding of the role of probiotics in chicken development and provide basic information on the genetic development of chickens.

Emodin Blocks mPTP Opening and Improves LPS-Induced HMEC-1 Cell Injury by Upregulation of ATP5A1

BACKGROUND

Emodin has been shown to exert anti-inflammatory and cytoprotective effects. Our study aimed to identify a novel anti-inflammatory mechanism of emodin.

METHODS

An LPS-induced model of microvascular endothelial cell (HMEC-1) injury was constructed. Cell proliferation was examined using a CCK-8 assay. The effects of emodin on reactive oxygen species (ROS), cell migration, the mitochondrial membrane potential (MMP), and the opening of the mitochondrial permeability transition pore (mPTP) were evaluated. Actin-Tracker Green was used to examine the relationship between cell microfilament reconstruction and ATP5A1 expression. The effects of emodin on the expression of ATP5A1, NALP3, and TNF-α were determined. After treatment with emodin, ATP5A1 and inflammatory factors (TNF-α, IL-1, IL-6, IL-13 and IL-18) were examined by Western blotting.

RESULTS

Emodin significantly increased HMEC-1 cell proliferation and migration, inhibited the production of ROS, increased the mitochondrial membrane potential, and blocked the opening of the mPTP. Moreover, emodin could increase ATP5A1 expression, ameliorate cell microfilament remodeling, and decrease the expression of inflammatory factors. In addition, when ATP5A1 was overexpressed, the regulatory effect of emodin on inflammatory factors was not significant.

CONCLUSION

Our findings suggest that emodin can protect HMEC-1 cells against inflammatory injury. This process is modulated by the expression of ATP5A1.

A landscape of mouse mitochondrial small non-coding RNAs

Small non-coding RNAs (ncRNAs), particularly miRNAs, play key roles in a plethora of biological processes both in health and disease. Although largely operative in the cytoplasm, emerging data indicate their shuttling in different subcellular compartments. Given the central role of mitochondria in cellular homeostasis, here we systematically profiled their small ncRNAs content across mouse tissues that largely rely on mitochondria functioning. The ubiquitous presence of piRNAs in mitochondria (mitopiRNA) of somatic tissues is reported for the first time, supporting the idea of a strong and general connection between mitochondria biology and piRNA pathways. Then, we found groups of tissue-shared and tissue-specific mitochondrial miRNAs (mitomiRs), potentially related to the "basic" or "cell context dependent" biology of mitochondria. Overall, this large data platform will be useful to deepen the knowledge about small ncRNAs processing and their governed regulatory networks contributing to mitochondria functions.

MTA1, a Novel ATP Synthase Complex Modulator, Enhances Colon Cancer Liver Metastasis by Driving Mitochondrial Metabolism Reprogramming

Liver metastasis is the most fatal event of colon cancer patients. Warburg effect has been long challenged by the fact of upregulated oxidative phosphorylation (OXPHOS), while its mechanism remains unclear. Here, metastasis-associated antigen 1 (MTA1) is identified as a newly identified adenosine triphosphate (ATP) synthase modulator by interacting with ATP synthase F1 subunit alpha (ATP5A), facilitates colon cancer liver metastasis by driving mitochondrial bioenergetic metabolism reprogramming, enhancing OXPHOS; therefore, modulating ATP synthase activity and downstream mTOR pathways. High-throughput screening of an anticancer drug shows MTA1 knockout increases the sensitivity of colon cancer to mitochondrial bioenergetic metabolism-targeted drugs and mTOR inhibitors. Inhibiting ATP5A enhances the sensitivity of liver-metastasized colon cancer to sirolimus in an MTA1-dependent manner. The therapeutic effects are verified in xenograft models and clinical cases. This research identifies a new modulator of mitochondrial bioenergetic reprogramming in cancer metastasis and reveals a new mechanism on upregulating mitochondrial OXPHOS as the reversal of Warburg effect in cancer metastasis is orchestrated.

Impact of Opioids on Cellular Metabolism: Implications for Metabolic Pathways Involved in Cancer

Opioid utilization for pain management is prevalent among cancer patients. There is significant evidence describing the many effects of opioids on cancer development. Despite the pivotal role of metabolic reprogramming in facilitating cancer growth and metastasis, the specific impact of opioids on crucial oncogenic metabolic pathways remains inadequately investigated. This review provides an understanding of the current research on opioid-mediated changes to cellular metabolic pathways crucial for oncogenesis, including glycolysis, the tricarboxylic acid cycle, glutaminolysis, and oxidative phosphorylation (OXPHOS). The existing literature suggests that opioids affect energy production pathways via increasing intracellular glucose levels, increasing the production of lactic acid, and reducing ATP levels through impediment of OXPHOS. Opioids modulate pathways involved in redox balance which may allow cancer cells to overcome ROS-mediated apoptotic signaling. The majority of studies have been conducted in healthy tissue with a predominant focus on neuronal cells. To comprehensively understand the impact of opioids on metabolic pathways critical to cancer progression, research must extend beyond healthy tissue and encompass patient-derived cancer tissue, allowing for a better understanding in the context of the metabolic reprogramming already undergone by cancer cells. The current literature is limited by a lack of direct experimentation exploring opioid-induced changes to cancer metabolism as they relate to tumor growth and patient outcome.

Aurora kinase A/AURKA functionally interacts with the mitochondrial ATP synthase to regulate energy metabolism and cell death

Cancer cells often hijack metabolic pathways to obtain the energy required to sustain their proliferation. Understanding the molecular mechanisms underlying cancer cell metabolism is key to fine-tune the metabolic preference of specific tumors, and potentially offer new therapeutic strategies. Here, we show that the pharmacological inhibition of mitochondrial Complex V delays the cell cycle by arresting breast cancer cell models in the G0/G1 phase. Under these conditions, the abundance of the multifunctional protein Aurora kinase A/AURKA is specifically lowered. We then demonstrate that AURKA functionally interacts with the mitochondrial Complex V core subunits ATP5F1A and ATP5F1B. Altering the AURKA/ATP5F1A/ATP5F1B nexus is sufficient to trigger G0/G1 arrest, and this is accompanied by decreased glycolysis and mitochondrial respiration rates. Last, we discover that the roles of the AURKA/ATP5F1A/ATP5F1B nexus depend on the specific metabolic propensity of triple-negative breast cancer cell lines, where they correlate with cell fate. On one hand, the nexus induces G0/G1 arrest in cells relying on oxidative phosphorylation as the main source of energy. On the other hand, it allows to bypass cell cycle arrest and it triggers cell death in cells with a glycolytic metabolism. Altogether, we provide evidence that AURKA and mitochondrial Complex V subunits cooperate to maintain cell metabolism in breast cancer cells. Our work paves the way to novel anti-cancer therapies targeting the AURKA/ATP5F1A/ATP5F1B nexus to lower cancer cell metabolism and proliferation.

1,4-dihydroxy quininib modulates the secretome of uveal melanoma tumour explants and a marker of oxidative phosphorylation in a metastatic xenograft model

Uveal melanoma (UM) is an intraocular cancer with propensity for liver metastases. The median overall survival (OS) for metastatic UM (MUM) is 1.07 years, with a reported range of 0.84-1.34. In primary UM, high cysteinyl leukotriene receptor 1 (CysLT₁) expression associates with poor outcomes. CysLT₁ antagonists, quininib and 1,4-dihydroxy quininib, alter cancer hallmarks of primary and metastatic UM cell lines in vitro. Here, the clinical relevance of CysLT receptors and therapeutic potential of quininib analogs is elaborated in UM using preclinical in vivo orthotopic xenograft models and ex vivo patient samples. Immunohistochemical staining of an independent cohort (n = 64) of primary UM patients confirmed high CysLT₁ expression significantly associates with death from metastatic disease (p = 0.02; HR 2.28; 95% CI 1.08-4.78), solidifying the disease relevance of CysLT₁ in UM. In primary UM samples (n = 11) cultured as ex vivo explants, 1,4-dihydroxy quininib significantly alters the secretion of IL-13, IL-2, and TNF-α. In an orthotopic, cell line-derived xenograft model of MUM, 1,4-dihydroxy quininib administered intraperitoneally at 25 mg/kg significantly decreases ATP5B expression (p = 0.03), a marker of oxidative phosphorylation. In UM, high ATP5F1B is a poor prognostic indicator, whereas low ATP5F1B, in combination with disomy 3, correlates with an absence of metastatic disease in the TCGA-UM dataset. These preclinical data highlight the diagnostic potential of CysLT₁ and ATP5F1B in UM, and the therapeutic potential of 1,4-dihydroxy quininib with ATP5F1B as a companion diagnostic to treat MUM.

Identification of miRNA-mRNA Regulatory Networks Associated with Diabetic Retinopathy using Bioinformatics Analysis

INTRODUCTION

Diabetic retinopathy (DR) is a major complication of diabetes and a leading cause of visual loss. This study aimed to explore biomarkers for DR that may provide additional reference to DR pathogenesis and development.

METHODS

The differentially expressed genes (DEGs) between the DR and control samples in the GSE53257 dataset were identified. Logistics analyses were performed to identify DR-associated miRNAs and genes, and correlation analysis was performed to determine the correlation between them in GSE160306.

RESULTS

A total of 114 DEGs in DR were identified in GSE53257. Three genes, including ATP5A1 (down), DAUFV2 (down), and OXA1L (down), were differentially expressed between DR and control samples in GSE160306. Univariate logistics analysis identified that ATP5A1 (OR=0.007, p = 1.40E-02), NDUFV2 (OR = 0.003, p = 6.40E-03), and OXA1L (OR = 0.093, p = 3.08E-02) were DR-associated genes. ATP5A1 and OXA1L were regulated by multiple miRNAs, of which hsa-let- 7b-5p (OR = 26.071, p = 4.40E-03) and hsa-miR-31-5p (OR = 4.188, p = 5.09E-02) were related to DR. ATP5A1 and OXA1L were closely correlated with each other in DR.

CONCLUSION

The hsa-miR-31-5p-ATP5A1 and hsa-let-7b-5p-OXA1L axes might play novel and important roles in the pathogenesis and development of DR.

Disrupting metformin adaptation of liver cancer cells by targeting the TOMM34/ATP5B axis

Metformin, a well-known antidiabetic drug, has been repurposed for cancer treatment; however, recently observed drug resistance and tumor metastasis have questioned its further application. Here, we found that long-term metformin exposure led to metabolic adaptation of hepatocellular carcinoma (HCC) cells, which was characterized by an obvious epithelial-mesenchymal transition (EMT) phenotype and compensatory elevation of oxidative phosphorylation (OXPHOS). TOMM34, a translocase of the outer mitochondrial membrane, was upregulated to promote tumor metastasis in response to metformin-induced metabolic stress. Mechanistically, TOMM34 interacted with ATP5B to preserve F₁ F_O -ATPase activity, which conferred mitochondrial OXPHOS and ATP production. This metabolic preference for OXPHOS suggested a large requirement of energy supply by cancer cells to survive and spread in response to therapeutic stress. Notably, disturbing the interaction between TOMM34 and ATP5B using Gboxin, a specific OXPHOS inhibitor, increased sensitivity to metformin and suppressed tumor progression both in vitro and in vivo. Overall, this study demonstrates a molecular link of the TOMM34/ATP5B-ATP synthesis axis during metformin adaptation and provides promising therapeutic targets for metformin sensitization in cancer treatment.

Crosstalk of Epigenetic and Metabolic Signaling Underpinning Glioblastoma Pathogenesis

Simple Summary

Epigenetic mechanisms can modulate key genes involved in the cellular metabolism of glioblastomas and participate in their pathogenesis by increasing their heterogeneity, plasticity, and malignancy. Although most epigenetic modifications can primarily promote the activity of metabolic pathways, they may also exert an inhibitory role. The detection of key metabolic alterations in gliomas regulated by epigenetic mechanisms will enable drug development and effective molecular targeting, improvement of therapeutic schemes, and patients’ management.

Abstract

Metabolic alterations in neoplastic cells have recently gained increasing attention as a main topic of research, playing a crucial regulatory role in the development and progression of tumors. The interplay between epigenetic modifications and metabolic pathways in glioblastoma cells has emerged as a key pathogenic area with great potential for targeted therapy. Epigenetic mechanisms have been demonstrated to affect main metabolic pathways, such as glycolysis, pentose phosphate pathway, gluconeogenesis, oxidative phosphorylation, TCA cycle, lipid, and glutamine metabolism by modifying key regulatory genes. Although epigenetic modifications can primarily promote the activity of metabolic pathways, they may also exert an inhibitory role. In this way, they participate in a complex network of interactions that regulate the metabolic behavior of malignant cells, increasing their heterogeneity and plasticity. Herein, we discuss the main epigenetic mechanisms that regulate the metabolic pathways in glioblastoma cells and highlight their targeting potential against tumor progression.

Targeting of Ubiquitin E3 Ligase RNF5 as a Novel Therapeutic Strategy in Neuroectodermal Tumors

RNF5, an endoplasmic reticulum (ER) E3 ubiquitin ligase, participates to the ER-associated protein degradation guaranteeing the protein homeostasis. Depending on tumor model tested, RNF5 exerts pro- or anti-tumor activity. The aim of this study was to elucidate the controversial role of RNF5 in neuroblastoma and melanoma, two neuroectodermal tumors of infancy and adulthood, respectively. RNF5 gene levels are evaluated in publicly available datasets reporting the gene expression profile of melanoma and neuroblastoma primary tumors at diagnosis. The therapeutic effect of Analog-1, an RNF5 pharmacological activator, was investigated on in vitro and in vivo neuroblastoma and melanoma models. In both neuroblastoma and melanoma patients the high expression of RNF5 correlated with a better prognostic outcome. Treatment of neuroblastoma and melanoma cell lines with Analog-1 reduced cell viability by impairing the glutamine availability and energy metabolism through inhibition of F1Fo ATP-synthase activity. This latter event led to a marked increase in oxidative stress, which, in turn, caused cell death. Similarly, neuroblastoma- and melanoma-bearing mice treated with Analog-1 showed a significant delay of tumor growth in comparison to those treated with vehicle only. These findings validate RNF5 as an innovative drug target and support the development of Analog-1 in early phase clinical trials for neuroblastoma and melanoma patients.

Loss of ATP5A1 enhances proliferation and predicts poor prognosis of colon adenocarcinoma

BACKGROUND

ATP Synthase F1 Subunit Alpha (ATP5F1A), also named as ATP5A1, is a subunit of mitochondrial ATP synthase. Dysregulated expression of ATP5A1 has been reported in several malignancies, nevertheless it showed either oncogenic or tumor-suppressing roles in different cancer types. Here we aimed to initially investigate the expression and role of ATP5A1 in colon adenocarcinoma.

METHODS

We firstly evaluated the transcription and mRNA levels of ATP5A1 using data from The Cancer Genome Atlas (TCGA). Besides, we tested its mRNA and protein expression in our enrolled retrospective cohort (n = 115). Univariate and multivariate analyzes were conducted to assess its prognostic value. Cellular experiments and xenografts in mice model were performed to validate the role of ATP5A1 in colon cancer.

RESULTS

ATP5A1 showed a significant lower level in colon adenocarcinoma than in adjacent nontumorous tissue. Advanced tumor stage was characterized with lower ATP5A1 level. Lower ATP5A1 was associated with poor prognosis in both TCGA dataset (P = 0.041) and our cohort (P = 0.001). Furthermore, Cox regression analysis demonstrated that ATP5A1 was a novel independent prognostic factor for colon cancer patients (HR=0.43, P = 0.018). Finally, cellular and xenografts data confirmed that overexpressing ATP5A1 can remarkably attenuate colon cancer growth.

CONCLUSION

Low expression of ATP5A1 may be a potential molecular marker for poor prognosis in colon cancer.

DATA AVAILABILITY

Data will be available upon request.

OKN-007 Alters Protein Expression Profiles in High-Grade Gliomas: Mass Spectral Analysis of Blood Sera

Current therapies for high-grade gliomas, particularly glioblastomas (GBM), do not extend patient survival beyond 16–22 months. OKN-007 (OKlahoma Nitrone 007), which is currently in phase II (multi-institutional) clinical trials for GBM patients, and has demonstrated efficacy in several rodent and human xenograft glioma models, shows some promise as an anti-glioma therapeutic, as it affects most aspects of tumorigenesis (tumor cell proliferation, angiogenesis, migration, and apoptosis). Combined with the chemotherapeutic agent temozolomide (TMZ), OKN-007 is even more effective by affecting chemo-resistant tumor cells. In this study, mass spectrometry (MS) methodology ESI-MS, mass peak analysis (Leave One Out Cross Validation (LOOCV) and tandem MS peptide sequence analyses), and bioinformatics analyses (Ingenuity^® Pathway Analysis (IPA^®)), were used to identify up- or down-regulated proteins in the blood sera of F98 glioma-bearing rats, that were either untreated or treated with OKN-007. Proteins of interest identified by tandem MS-MS that were decreased in sera from tumor-bearing rats that were either OKN-007-treated or untreated included ABCA2, ATP5B, CNTN2, ITGA3, KMT2D, MYCBP2, NOTCH3, and VCAN. Conversely, proteins of interest in tumor-bearing rats that were elevated following OKN-007 treatment included ABCA6, ADAMTS18, VWA8, MACF1, and LAMA5. These findings, in general, support our previous gene analysis, indicating that OKN-007 may be effective against the ECM. These findings also surmise that OKN-007 may be more effective against oligodendrogliomas, other brain tumors such as medulloblastoma, and possibly other types of cancers.

The Metabolism Reprogramming of microRNA Let-7-Mediated Glycolysis Contributes to Autophagy and Tumor Progression

Cancer is usually a result of abnormal glucose uptake and imbalanced nutrient metabolization. The dysregulation of glucose metabolism, which controls the processes of glycolysis, gives rise to various physiological defects. Autophagy is one of the metabolic-related cellular functions and involves not only energy regeneration but also tumorigenesis. The dysregulation of autophagy impacts on the imbalance of metabolic homeostasis and leads to a variety of disorders. In particular, the microRNA (miRNA) Let-7 has been identified as related to glycolysis procedures such as tissue repair, stem cell-derived cardiomyocytes, and tumoral metastasis. In many cancers, the expression of glycolysis-related enzymes is correlated with Let-7, in which multiple enzymes are related to the regulation of the autophagy process. However, much recent research has not comprehensively investigated how Let-7 participates in glycolytic reprogramming or its links to autophagic regulations, mainly in tumor progression. Through an integrated literature review and omics-related profiling correlation, this review provides the possible linkage of the Let-7 network between glycolysis and autophagy, and its role in tumor progression.

Defueling the cancer: ATP synthase as an emerging target in cancer therapy

Reprogramming of cellular metabolism is a hallmark of cancer. Mitochondrial ATP synthase (MAS) produces most of the ATP that drives the cell. High expression of the MAS-composing proteins is found during cancer and is linked to a poor prognosis in glioblastoma, ovarian cancer, prostate cancer, breast cancer, and clear cell renal cell carcinoma. Cell surface-expressed ATP synthase, translocated from mitochondrion to cell membrane, involves the angiogenesis, tumorigenesis, and metastasis of cancer. ATP synthase has therefore been considered a therapeutic target. We review recent various ATP synthase inhibitors that suppress tumor growth and are being tested for the clinic.

Design, synthesis, and target identification of new hypoxia-inducible factor 1 (HIF-1) inhibitors containing 1-alkyl-1H-pyrazole-3-carboxamide moiety

Hypoxia-inducible factor 1 (HIF-1) is a promising drug target for cancer chemotherapy. In our screening program aimed at identifying new HIF-1 inhibitors by using a hypoxia-responsive luciferase reporter gene assay, KUSC-5001 containing the 1-alkyl-1H-pyrazole-3-carboxamide moiety was found as a potential hit molecule. During an extensive structure-activity relationship (SAR) study, we developed a more effective HIF-1 inhibitor KUSC-5037 (IC₅₀ = 1.2 μM). Under hypoxic conditions, KUSC-5037 suppressed the HIF-1α (a regulatory subunit of HIF-1) mRNA, causing decreases in the gene expression of HIF-1 target genes such as carbonic anhydrase 9 (CA9) and vascular endothelial growth factor (VEGF) genes. Furthermore, by applying our fluorescent and bifunctional probes, ATP5B, a catalytic β subunit of mitochondrial F_oF₁-ATP synthase, was identified as a target protein of KUSC-5037. These results indicate that the derivatives of KUSC-5037 containing the 1-alkyl-1H-pyrazole-3-carboxamide moiety are promising lead molecules for the inhibition of HIF-1 signaling via F_oF₁-ATP synthase suppression.

ATP5B promotes the metastasis and growth of gastric cancer by activating the FAK/AKT/MMP2 pathway

Adenosine triphosphate (ATP) in the tumor microenvironment serves a vital role during tumor progression. ATP synthase F1 β subunit (ATP5B) is one of the most important subunits of ATP synthase and increases cellular ATP levels. ATP5B reportedly participates in carcinogenesis in several tumors. However, the regulatory mechanisms of ATP5B remain poorly understood in gastric cancer (GC). Here, we determined that high ATP5B expression in tumor tissues of GC is positively correlated with age, the tumor size, the TNM stage, lymph node metastasis, and patients' poor prognosis. The overexpression of ATP5B in GC cells elevated the cellular ATP content and promoted migration, invasion and proliferation. The levels of MMP2 expression, phosphorylated FAK, and phosphorylated AKT were increased after ATP5B overexpression in GC cells. Additionally, ATP5B overexpression increased the extracellular ATP level through the secretion of intracellular ATP and activated the FAK/AKT/MMP2 signaling pathway. ATP5B-induced downstream pathway activation was induced through the plasma membrane P2X7 receptor. Inhibitors of P2X7, FAK, AKT, and MMP2 suppressed the proliferative, migratory, and invasive capabilities of GC cells. In conclusion, our experiments indicate that ATP5B contributes to tumor progression of GC via FAK/AKT/MMP2 pathway. ATP5B, therefore, may be a biomarker of poor prognosis and a potential therapeutic target for GC.

Transcriptional Changes after Enniatins A, A1, B and B1 Ingestion in Rat Stomach, Liver, Kidney and Lower Intestine

Enniatins (ENs) are depsipeptide mycotoxins produced by Fusarium fungi. They are known for their capacity to modulate cell membrane permeability and disruption of ionic gradients, affecting cell homeostasis and initiating oxidative stress mechanisms. The effect of the acute toxicity of ENs A, A1, B and B1 at two different concentrations after 8 h of exposure was analysed in Wistar rats by a transcriptional approach. The following key mitochondrial and nuclear codified genes related to the electron transport chain were considered for gene expression analysis in stomach, liver, kidney and lower intestine by quantitative Real-Time PCR: mitochondrially encoded NADH dehydrogenase 1 (MT-ND1), mitochondrially encoded cytochrome c oxidase 1 (MT-COX1), succinate dehydrogenase flavoprotein subunit A and ATP synthase F1 subunit alpha, respectively. Moreover, the expression of markers involved in oxidative stresssuperoxide dismutase 1 (SOD1), glutathione peroxidase 1 (Gpx1), heme oxygenase 1, apoptosis B-cell lymphoma 2, Bcl2 Associated protein X (Bax), tumor suppressor protein (p53), inhibition of apoptosis nuclear factor kappa of activated B cells, immune system interleukin 1β and intestinal tight junction Occludin merely in lower intestine tissues have been investigated. For mitochondrial genes, the main differences were observed for MT-ND1 and MT-COX1, showing its deficiency in all selected organs. With regard to the intestinal barrier’s cellular response to oxidative stress, the activity of the antioxidant gene SOD1 was decreased in a dose-dependent manner. Similarly, the catalytic enzyme GPx1 was also downregulated though merely at medium dose employed. On the contrary, the pro-apoptotic Bax and p53 regulators were activated after ENs exposure, reporting a significant increase in their expression. Furthermore, the alteration of intestinal permeability was assessed by the abnormal activity of the tight junction protein occludin. In summary, ENs may generate mitochondrial disorders and induce oxidative stress in intestinal barrier function.

MicroRNAs: emerging driver of cancer perineural invasion

The perineural invasion (PNI), which refers to tumor cells encroaching on nerve, is a clinical feature frequently occurred in various malignant tumors, and responsible for postoperative recurrence, metastasis and decreased survival. The pathogenesis of PNI switches from 'low-resistance channel' hypothesis to 'mutual attraction' theory between peripheral nerves and tumor cells in perineural niche. Among various molecules in perineural niche, microRNA (miRNA) as an emerging modulator of PNI through generating RNA-induced silencing complex (RISC) to orchestrate oncogene and anti-oncogene has aroused a wide attention. This article systematically reviewed the role of microRNA in PNI, promising to identify new biomarkers and offer cancer therapeutic targets.

Integrated Analyses Reveal the Multi-Omics and Prognostic Characteristics of ATP5B in Breast Cancer

The beta subunit of F1Fo-ATP synthase (ATP5B) has been demonstrated to play an essential role in tumor progression and metastasis. However, there has been no comprehensive pan-cancer multi-omics analysis of ATP5B, while the clinical relevance of ATP5B and its potential mechanism in regulating breast cancer are still poorly understood. In this study, we demonstrated that ATP5B has a higher frequency of amplification than deletion in most cancer types, and the copy number variation (CNV) of ATP5B was significantly positively correlated with its mRNA expression level. DNA methylation analysis across pan-cancer also revealed a strong correlation between ATP5B expression and epigenetic changes. We identified 6 significant methylation sites involved in the regulation of ATP5B expression. Tissue microarrays (TMA) from 129 breast cancer samples, integrated with multiple additional breast cancer dataset, were used to evaluate the ATP5B expression and its correlation with prognosis. Higher levels of ATP5B expression were consistently associated with a worse OS in all datasets, and Cox regression analysis suggested that ATP5B expression was an independent prognostic factor. Gene enrichment analysis indicated that the gene signatures of DNA damage recognition, the E-cadherin nascent pathway and the PLK1 pathway were enriched in ATP5B-high patients. Moreover, somatic mutation analysis showed that a significant different mutation frequency of CDH1 and ADAMTSL3 could be observed between the ATP5B-high and ATP5B-low groups. In conclusion, this study reveals novel significance regarding the genetic characteristics and clinical value of ATP5B highlighted in predicting the outcome of breast cancer patients.

Effects of Induced Exosomes from Endometrial Cancer Cells on Tumor Activity in the Presence of Aurea helianthus Extract

Endometrial cancer (EC) cells metastasize to various regions, including the ovaries, fallopian tubes, cervix, blood, liver, bone, and brain. Various carcinogens are known to cause EC. Exosomes are released from several types of cells and contain various cellular components. In this study, flow cytometry and quantitative PCR were used to evaluate marker levels, cell migration, cell invasion, and mitochondrial membrane potential, and cellular senescence tests were used to estimate cancer activity. The microRNAs were profiled using next-generation sequencing. Although tocopherol-α and rutin content in Aurea helianthus is high, A. helianthus extract was more useful in modulating tumor activity compared to the two aforementioned substances. Notably, we established that the extract induced bioactive exosomes in EC cells, and profiling of miRNAs in the extract-inducing exosomes (EIE) indicated their potency to be developed as a biological drug. The extract and EIE contributed to the following five biological process categories for EC cells: (1) cell migration and invasion suppression, (2) cellular senescence activation by attenuating mitochondrial membrane potential and enhancing autophagy, (3) reproductive cancer activity attenuation, (4) drug susceptibility activation, and (5) EIE containing miRNAs associated with decreasing inflammation.

Screening of Potential Biomarkers for Gastric Cancer with Diagnostic Value Using Label-free Global Proteome Analysis

Gastric cancer (GC) is known as a top malignant type of tumors worldwide. Despite the recent decrease in mortality rates, the prognosis remains poor. Therefore, it is necessary to find novel biomarkers with early diagnostic value for GC. In this study, we present a large-scale proteomic analysis of 30 GC tissues and 30 matched healthy tissues using label-free global proteome profiling. Our results identified 537 differentially expressed proteins, including 280 upregulated and 257 downregulated proteins. The ingenuity pathway analysis (IPA) results indicated that the sirtuin signaling pathway was the most activated pathway in GC tissues whereas oxidative phosphorylation was the most inhibited. Moreover, the most activated molecular function was cellular movement, including tissue invasion by tumor cell lines. Based on IPA results, 15 hub proteins were screened. Using the receiver operating characteristic curve, most of hub proteins showed a high diagnostic power in distinguishing between tumors and healthy controls. A four-protein (ATP5B-ATP5O-NDUFB4-NDUFB8) diagnostic signature was built using a random forest model. The area under the curve (AUC) values of this model were 0.996 and 0.886 for the training and testing sets, respectively, suggesting that the four-protein signature has a high diagnostic power. This signature was further tested with independent datasets using plasma enzyme-linked immune sorbent assays, resulting in an AUC value of 0.778 for distinguishing GC tissues from healthy controls, and using immunohistochemical tissue microarray analysis, resulting in an AUC value of 0.805. In conclusion, this study identifies potential biomarkers and improves our understanding of the pathogenesis, providing novel therapeutic targets for GC.

ATP5A1 Participates in Transcriptional and Posttranscriptional Regulation of Cancer-Associated Genes by Modulating Their Expression and Alternative Splicing Profiles in HeLa Cells

Background: Aberrant expression and alternative splicing of oncogenes are the driving events in tumor initiation and development. But how these events are regulated in cancer cells is largely unknown. Functions of ATP5A1, an important mitochondrial ATP synthase gene, in transcriptional and posttranscriptional regulation were explored in this study. Methods: ATP5A1 was overexpressed using plasmid-transformed HeLa cells, and its influence on cell apoptosis and proliferation is evaluated. Transcriptome sequencing was then performed using RNA-seq to study the changes in gene expression and regulation of alternative splicing events. Validation of the implicated genes was achieved using RT-qPCR analysis. Results: It was found that ATP5A1 could significantly promote cellular apoptosis, but it had no influence on cell proliferation. ATP5A1 overexpression significantly increased the expression levels of genes associated with the innate immune response, angiogenesis, and collagen catabolic processes. This included enrichment of MMP2 and MMP19. It was also found that ATP5A1 could interfere with the alternative splicing of hundreds of genes associated with glucose homeostasis, HIF-1 signaling activation, and several pathways associated with cancers. Eight ATP5A1-regulated differentially expressed genes and 3 genes altered by splicing were selected and validated using RT-qPCR analysis. Conclusions: In summary, we illustrate the regulatory functions of ATP5A1 on the transcriptome of HeLa cells by exploring its influence on gene expression and alternative splicing. The results suggest that ATP5A1 may play an important regulatory role in cervical cancer cells by regulating expression and alternative splicing of cancer-associated genes. This study provides novel insights into the current understanding of the mechanisms of ATP5A1 on carcinogenesis and cancer progression.

Epigenetics of glioblastoma multiforme: From molecular mechanisms to therapeutic approaches

Glioblastoma multiforme (GBM) is the most common form of brain cancer and one of the most aggressive cancers found in humans. Most of the signs and symptoms of GBM can be mild and slowly aggravated, although other symptoms might demonstrate it as an acute ailment. However, the precise mechanisms of the development of GBM remain unknown. Due to the improvement of molecular pathology, current researches have reported that glioma progression is strongly connected with different types of epigenetic phenomena, such as histone modifications, DNA methylation, chromatin remodeling, and aberrant microRNA. Furthermore, the genes and the proteins that control these alterations have become novel targets for treating glioma because of the reversibility of epigenetic modifications. In some cases, gene mutations including P16, TP53, and EGFR, have been observed in GBM. In contrast, monosomies, including removals of chromosome 10, particularly q23 and q25-26, are considered the standard markers for determining the development and aggressiveness of GBM. Recently, amid the epigenetic therapies, histone deacetylase inhibitors (HDACIs) and DNA methyltransferase inhibitors have been used for treating tumors, either single or combined. Specifically, HDACIs are served as a good choice and deliver a novel pathway to treat GBM. In this review, we focus on the epigenetics of GBM and the consequence of its mutations. We also highlight various treatment approaches, namely gene editing, epigenetic drugs, and microRNAs to combat GBM.

Importance of Mitochondrial-Related Genes in Dilated Cardiomyopathy Based on Bioinformatics Analysis

We designed this study to identify potential key protein interaction networks, genes, and correlated pathways in dilated cardiomyopathy (DCM) via bioinformatics methods. We selected the GSE3586 microarray dataset, consisting of 15 dilated cardiomyopathic heart biopsy samples and 13 nonfailing heart biopsy samples. Initially, the GSE3586 dataset was downloaded and was analyzed with the limma package to identify differentially expressed genes (DEGs). A total of 172 DEGs consisting of 162 upregulated genes and ten downregulated genes in DCM were selected by the criterion of adjusted Pvalues less than 0.01 and the log2-fold change of 0.6 or greater. Gene Ontology functional enrichment analysis and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis were performed to view the biological processes, cellular components, molecular function, and KEGG pathways of the DEGs. Next, protein-protein interactions were constructed, and the hub protein modules were identified. Then we selected the key genes DLD, UQCRC2, DLAT, SUCLA2, ATP5A1, PRDX3, FH, SDHD, and NDUFV1, which are involved in a wide range of biological activities, such as the citrate cycle, oxidation-reduction processes and cellular respiration, and energy derivation by oxidation of organic compounds in mitochondria. Finally, we found that currently there are no related gene-targeting drugs after exploring the predicted interactions between key genes and drugs, and transcription factors. In conclusion, our study provides greater understanding of the pathogenesis and underlying molecular mechanisms in DCM. This contributes to the exploration of potential gene therapy targets.

The role of mitochondrial ATP synthase in cancer

The mitochondrial ATP synthase is a multi-subunit enzyme complex located in the inner mitochondrial membrane which is essential for oxidative phosphorylation under physiological conditions. In this review, we analyse the enzyme functions involved in cancer progression by dissecting specific conditions in which ATP synthase contributes to cancer development or metastasis. Moreover, we propose the role of ATP synthase in the formation of the permeability transition pore (PTP) as an additional mechanism which controls tumour cell death. We further describe transcriptional and translational modifications of the enzyme subunits and of the inhibitor protein IF1 that may promote adaptations leading to cancer metabolism. Finally, we outline ATP synthase gene mutations and epigenetic modifications associated with cancer development or drug resistance, with the aim of highlighting this enzyme complex as a potential novel target for future anti-cancer therapy.

Integrative Analysis of Siglec-15 mRNA in Human Cancers Based on Data Mining

Objective: Cancer is expected to be the leading cause of death worldwide within the 21st century and is the single most important obstacle to extending life expectancy. Unfortunately, the most effective approach to combating cancers remains a complex and unsolved problem. Siglec-15 is a member of the Siglec family and plays a conserved regulatory role in the immune system of vertebrates. Previous studies on Siglec-15 have focused on its function in osteoclast regulation. The purpose of this study was to explore the significance of Siglec-15 mRNA in human cancer mainly based on information obtained from online databases. Method: Data were collected from several online databases. Serial analysis of gene expression (SAGE) and Virtual Northern, UALCAN Database Analysis, Catalog of Somatic Mutations in Cancer (COSMIC) analysis, the cBio cancer genomics portal, Cancer Regulome tools and data, Kaplan-Meier Plotter Analysis and the UCSC Xena website were used to analyze the data. Results: Compared with normal tissues, Siglec-15 up-regulation was widely observed in tuomrs. Differences in Siglec-15 expression were associated with different prognoses. Siglec-15 mutations are widely observed in tumors and interact with different genes in different cancer types. Conclusion: Siglec-15 is a potential target for the expansion of cancer immunotherapy.

Identification of ATP synthase α subunit as a new maternal factor capable of protecting zebrafish embryos from bacterial infection

Previous studies have shown that ATP synthase α subunit (ATP5A1) plays multiple roles, but our understanding of its biologic functions remains poor and incomprehensive. Here, we clearly demonstrated that zebrafish ATP5A1 was a newly characterized lipoteichoic acid (LTA)- and LPS-binding protein abundantly stored in the eggs and embryos of zebrafish. Zebrafish ATP5A1 acted not only as a pattern recognition receptor, capable of identifying LTA and LPS, but also as an effector molecule, capable of inhibiting the growth of both gram-positive and -negative bacteria. ATP5A1 could disrupt the bacterial membranes by a combined action of membrane depolarization and permeabilization. We also found that the N-terminal 65 residues were critical for the antibacterial activity of zebrafish ATP5A1. In particular, we showed that microinjection of exogenous recombinant (r)ATP5A1 into early embryos could promote their resistance against pathogenic Aeromonas hydrophila challenge, and this pathogen-resistant activity was markedly reduced by the coinjection of anti-ATP5A1 antibody or by the knockdown with morpholino for atp5a1 but not by the coinjection of anti-actin antibody. Moreover, each egg/embryo contains a sufficient amount of ATP5A1 in vivo to kill A. hydrophila. Furthermore, the N-terminal 65 residues 1-65 of ATP5A1 α subunit (rA_1-65) with in vitro antibacterial activity also promoted the resistance of embryos against A. hydrophila, but the N-terminal 69 residues 66-134 (rA_66-134) or C-terminal residues 135-551 (rA_135-551) of ATP5A1 α subunit without in vitro antibacterial activity did not. Finally, we showed that the antibacterial activity of the N-terminal 65 residues of ATP5A1 α subunit was conserved throughout animal evolution. Collectively, these results indicate that ATP5A1 is a novel maternal immunocompetent factor that can protect the early embryos of zebrafish from bacterial infection. This work also provides a new viewpoint for understanding the biologic roles of ATP5A1, which is ubiquitously present in animals.-Ni, S., Zhou, Y., Chen, Y., Du, X., Zhang, S. Identification of ATP synthase α subunit as a new maternal factor capable of protecting zebrafish embryos from bacterial infection.

Proteomic characterization of bovine granulosa cells in dominant and subordinate follicles

Background

Characterization of molecular factors regulating ovarian follicular development is critical to understanding its functional mechanism of controlling the estrous cycle, determining oocyte competency, and regulating ovulation. In previous studies, we performed next-gene sequencing to investigate the differentially expressed transcripts of bovine follicular granulosa cells (GCs) at the dominant follicle (DF) and subordinate follicle (SF) stages during the first follicular wave. This study aims to investigate the proteomic characterization of GCs of DF and SF in the bovine estrous cycle.

Results

In total, 3409 proteins were identified from 30,321 peptides obtained from liquid chromatograph-mass spectrometer analysis. Two hundred fifty-nine of these proteins were found to be expressed differently in DF and SF. Out of 259, a total of 26 proteins were upregulated (fold change≥2) and 233 proteins were downregulated (fold change≤0.5) in DF. Gene Ontology (GO) analysis of proteome data revealed the biological process, cellular component and molecular function of expressed proteins in DF and SF, while the Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis showed important signaling pathways associated with follicular development such as the PI3K-Akt, estrogen, and insulin signaling pathways. Immunoblotting results of OGN, ROR2, and HSPB1 confirmed the accuracy of the data. Bioinformatics analysis showed that 13 proteins may be linked to follicular development.

Conclusions

Findings from this study will provide useful information for exploring follicular development and function.

Electronic supplementary material

The online version of this article (10.1186/s41065-019-0097-5) contains supplementary material, which is available to authorized users.

Involvement of Extracellular Vesicles in Vascular-Related Functions in Cancer Progression and Metastasis

The primary cause of mortality among patients with cancer is the progression of the tumor, better known as cancer invasion and metastasis. Cancer progression involves a series of biologically important steps in which the cross-talk between cancer cells and the cells in the surrounding environment is positioned as an important issue. Notably, angiogenesis is a key tumorigenic phenomenon for cancer progression. Cancer-related extracellular vesicles (EVs) commonly contribute to the modulation of a microenvironment favorable to cancer cells through their function of cell-to-cell communication. Vascular-related cells such as endothelial cells (ECs) and platelets activated by cancer cells and cancer-derived EVs develop procoagulant and proinflammatory statuses, which help excite the tumor environment, and play major roles in tumor progression, including in tumor extravasation, tumor cell microthrombi formation, platelet aggregation, and metastasis. In particular, cancer-derived EVs influence ECs, which then play multiple roles such as contributing to tumor angiogenesis, loss of endothelial vascular barrier by binding to ECs, and the subsequent endothelial-to-mesenchymal transition, i.e., extracellular matrix remodeling. Thus, cell-to-cell communication between cancer cells and ECs via EVs may be an important target for controlling cancer progression. This review describes the current knowledge regarding the involvement of EVs, especially exosomes derived from cancer cells, in EC-related cancer progression.

MicroRNAs in brain development and cerebrovascular pathophysiology

MicroRNAs (miRNAs) are a class of highly conserved non-coding RNAs with 21-25 nucleotides in length and play an important role in regulating gene expression at the posttranscriptional level via base-paring with complementary sequences of the 3'-untranslated region of the target gene mRNA, leading to either transcript degradation or translation inhibition. Brain-enriched miRNAs act as versatile regulators of brain development and function, including neural lineage and subtype determination, neurogenesis, synapse formation and plasticity, neural stem cell proliferation and differentiation, and responses to insults. Herein, we summarize the current knowledge regarding the role of miRNAs in brain development and cerebrovascular pathophysiology. We review recent progress of the miRNA-based mechanisms in neuronal and cerebrovascular development as well as their role in hypoxic-ischemic brain injury. These findings hold great promise, not just for deeper understanding of basic brain biology but also for building new therapeutic strategies for prevention and treatment of pathologies such as cerebral ischemia.

Epigenetic modulation of metabolism in glioblastoma

Epigenetic and metabolic alterations incancer cells are highly associated. Glioblastoma multiforme (GBM) is a complicated pathological process with dysregulated methylation and histone modifications. Metabolic modulation of epigenetics in gliomas was previously summarized. However, epigenetic modulation is also important in metabolic decision. Recently, there has been a tremendous increase in understanding of DNA methylation, chromatin modulation, and non-coding RNAs in the regulation of cell metabolism, especially glycolytic metabolism in GBM. In this review, we summarize DNA methylation, histone alteration, and non-coding RNA mediated epigenetic modulation of metabolism in GBM and discuss the future research directions in this area and its applications in GBM treatment.

Proteasome 26S subunit PSMD1 regulates breast cancer cell growth through p53 protein degradation

Endocrine therapy using antiestrogens and aromatase inhibitors is usually efficient to treat patients with hormone-sensitive breast cancer. Many patients with endocrine therapy, however, often acquire resistance. In the present study, we performed functional screening using short hairpin RNA library to dissect genes involved in antiestrogen tamoxifen resistance in MCF-7 breast cancer cells. We identified seven candidate genes that are associated with poor prognosis of breast cancer patients based on clinical dataset. The expression levels of six out of seven genes were higher in 4-hydroxytamoxifen (OHT) resistant MCF-7 (OHTR) cells compared with parental MCF-7 cells. Among the six selected genes, siRNA-mediated knockdown of PSMD1 and TSPAN12 markedly reduced the proliferation of OHTR cells. Notably, the knockdown of proteasome 26S subunit PSMD1 exhibited cell cycle arrest and the accumulation of p53 protein through inhibiting p53 protein degradation. In accordance with p53 accumulation, its target genes p21 and SFN were also upregulated by PSMD1 silencing. Taken together, PSMD1 was identified as a potential gene that plays a role in the development of tamoxifen resistance in breast cancer cells. These findings will provide a new insight for the mechanism underlying endocrine therapy resistance and a prognostic and therapeutic molecular target for advanced breast cancer.

Mechanistic studies on ketamine-induced mitochondrial toxicity in zebrafish embryos

Ketamine, a phencyclidine derivative, is an antagonist of the Ca²⁺-permeable N-methyl-d-aspartate (NMDA)-type glutamate receptors. It is a pediatric anesthetic and has been implicated in developmental neurotoxicity. Ketamine has also been shown to deplete ATP in mammalian cells. Our previous studies showed that acetyl l-carnitine (ALCAR) prevented ketamine-induced cardiotoxicity and neurotoxicity in zebrafish embryos. Based on our finding that ALCAR's protective effect was blunted by oligomycin A, an inhibitor of ATP synthase, we further investigated the effects of ketamine and ALCAR on ATP levels, mitochondria and ATP synthase in zebrafish embryos. The results demonstrated that ketamine reduced ATP levels in the embryos but not in the presence of ALCAR. Ketamine reduced total mitochondrial protein levels and mitochondrial potential, which were prevented with ALCAR co-treatment. To determine the cause of ketamine-induced ATP deficiency, we explored the status of ATP synthase. The results showed that a subunit of ATP synthase, atp5α1, was transcriptionally down-regulated by ketamine, but not in the presence of ALCAR, although ketamine caused a significant upregulation in another ATP synthase subunit, atp5β and total ATP synthase protein levels. Most of the ATP generated by heart mitochondria are utilized for its contraction and relaxation. Ketamine-treated embryos showed abnormal heart structure, which was abolished with ALCAR co-treatment. This study offers evidence for a potential mechanism by which ketamine could cause ATP deficiency mediated by mitochondrial dysfunction.

A novel correlation between ATP5A1 gene expression and progression of human clear cell renal cell carcinoma identified by co‑expression analysis

Clear cell renal cell carcinoma (ccRCC) is the most common solid lesion within kidneys, and its prognostic is influenced by the progression covering a complex network of gene interactions. In our study, a weighted gene co-expression network was constructed to identify gene modules associated with the progression of ccRCC (n=35). In the significant module (R² = −0.53), a total of 13 network hub genes were identified, and 2 of them were hub nodes in the protein-protein interaction network as well. In validation, ATP5A1 showed a higher correlation with the disease progression than any other hub gene in the hub module (P=0.001219). In the test set (n=202), ATP5A1 was also highly expressed in normal kidney than ccRCC tissues of each grade (P<0.001). Functional and pathway enrichment analysis demonstrated that ATP5A1 is overrepresented in pathway of oxidative phosphorylation, which associated with tumorigenesis and tumor progression. Gene set enrichment analysis (GSEA) also demonstrated that the gene set of ‘oxidative phosphorylation’ and metabolic pathways were enriched in ccRCC samples with ATP5A1 highly expressed (P<0.05). In conclusion, based on the co-expression analysis, ATP5A1 was validated to be associated with progression of ccRCC, probably by regulating tumor-related phosphorylation.

On mitochondrial metabolism in tumor biology

PURPOSE OF REVIEW

To provide examples of mitochondria-specific metabolic events that influence tumor cell biology, and of metabolism-related mitochondrial biomarkers and therapeutic targets in cancer cells.

RECENT FINDINGS

Cancer cell mitochondria are rewired to optimally serve the cancer cell under various conditions of cellular stress. The nonexhaustive list of mitochondrial alterations that support cancer cell proliferation, survival, and/or progression includes upregulation of oxidative metabolism and use of alternative substrates, oncometabolites, increased superoxide production, mutated mitochondrial DNA, and altered mitochondrial morphology and dynamics. Potential therapeutic targets include fatty acid oxidation, voltage-dependent anion channel-1, the pyruvate dehydrogenase complex, and Complex I.

SUMMARY

Some phenotypical traits, for example, chemoresistance and metastasis, are likely regulated by a fine-tuned balance between several metabolic processes and events that are upregulated in parallel and are also dependent on microenvironmental cues. Many metabolism-related mitochondrial biomarkers show prognostic value, but the biological interpretation of the data may be confounded by the overall metabolic status and context. Understanding metabolic regulation of stemness is important for targeting cancer stem cells. Therapeutic targeting of cancer cell mitochondria remains experimental but promising, and more predictive markers will be needed for metabolism-based treatments and personalized medicine.

Systematic Analysis of the Expression of the Mitochondrial ATP Synthase (Complex V) Subunits in Clear Cell Renal Cell Carcinoma

Mitochondrial dysfunction is common in cancer and the mitochondrial electron transport chain is often affected in carcinogenesis. To date, little is known about the expression of the ATP synthase subunits in clear cell renal cell carcinoma (ccRCC). The NextBio database was used to determine an expression profile of the ATP synthase subunits based on published microarray studies. We observed down-regulation of 23 out of 29 subunits of the ATP synthase. Differential expression was validated exemplarily for 12 genes (ATP5A1, ATP5B, ATPAF1, ATP5C1, ATP5D, ATP5O, ATP5F1, ATP5G1, ATP5G2, ATP5G3, ATP5I, ATP5S; screening cohort ccRCC n = 18 and normal renal tissue n = 10) using real-time PCR. Additional eight genes (ATP5A1, ATP5B, ATPAF1, ATP5F1, ATP5G1, ATP5G2, ATP5G3, ATP5S) were internally validated within an enlarged cohort (ccRCC n = 74; normal renal tissue n = 36). Furthermore, down-regulation of ATP5A1, ATPAF1, ATP5G1/G2/G3 was confirmed on the protein level using Western Blot and immunohistochemistry. We observed that altered expression of ATPAF1 and ATP5G1/G2/G3 was correlated with overall survival in patients with ccRCC. In conclusion, down-regulation of many ATP Synthase subunits occurs in ccRCC and is the basis for the reduced activity of the mitochondrial electron chain. Alteration of the expression of ATP5A1, ATPAF1, and ATP5G1/G2/G3 is characteristic for ccRCC and may be prognostic for ccRCC patients' outcome.

Tumor suppressors microRNA-302d and microRNA-16 inhibit human glioblastoma multiforme by targeting NF-κB and FGF2

MicroRNA-302d and microRNA-16 inhibit glioblastoma multiforme by targeting NF-κB p65 and FGF2.

Differential expression of PDGFRB and EGFR in microvascular proliferation in glioblastoma

Glioblastoma (GBM) is the highly malignant glioma and exhibits microvascular proliferation. PCR mRNA arrays and immunohistochemical stains on tissue microarray demonstrated that the expression level of PDGFRB in GBM microvascular proliferation was significantly higher than that in GBM tumor cells while the expression level of EGFR was lower in microvascular proliferation than in GBM tumor cells. PDGFRB protein was selectively expressed in pericytes in GBM microvascular proliferation. By analyzing The Cancer Genome Atlas (TCGA) datasets for GBM, it was found that genomic DNA alterations were the main reason for the high expression of EGFR in GBM tumor cells. Our miRNA microarray data showed that microRNAs (miRNAs) (miR-193b-3p, miR-518b, miR-520f-3p, and miR-506-5p) targeting PDGFRB were downregulated in microvascular proliferation, which might be the most likely reason for the high expression of PDGFRB in GBM microvascular proliferation. The increase of several miRNAs (miR-133b, miR-30b-3p, miR-145-5p, and miR-146a-5p) targeting EGFR in GBM microvascular proliferation was one of the reasons for the lack of expression of EGFR in GBM microvascular proliferation. These findings implicated that miRNAs, such as miR-506, miR-133b, miR-145, and miR-146a, that target PDGFRB or EGFR, might be potential therapeutic agents for GBM. A new generation of targeted therapeutic agents against both EGFR and PDGFRB might be developed in the future.