MEMO1, a new IRS1-interacting protein, induces epithelial-mesenchymal transition in mammary epithelial cells

MEMO1 binds iron and modulates iron homeostasis in cancer cells

Mediator of ERBB2-driven cell motility 1 (MEMO1) is an evolutionary conserved protein implicated in many biological processes; however, its primary molecular function remains unknown. Importantly, MEMO1 is overexpressed in many types of cancer and was shown to modulate breast cancer metastasis through altered cell motility. To better understand the function of MEMO1 in cancer cells, we analyzed genetic interactions of MEMO1 using gene essentiality data from 1028 cancer cell lines and found multiple iron-related genes exhibiting genetic relationships with MEMO1. We experimentally confirmed several interactions between MEMO1 and iron-related proteins in living cells, most notably, transferrin receptor 2 (TFR2), mitoferrin-2 (SLC25A28), and the global iron response regulator IRP1 (ACO1). These interactions indicate that cells with high-MEMO1 expression levels are hypersensitive to the disruptions in iron distribution. Our data also indicate that MEMO1 is involved in ferroptosis and is linked to iron supply to mitochondria. We have found that purified MEMO1 binds iron with high affinity under redox conditions mimicking intracellular environment and solved MEMO1 structures in complex with iron and copper. Our work reveals that the iron coordination mode in MEMO1 is very similar to that of iron-containing extradiol dioxygenases, which also display a similar structural fold. We conclude that MEMO1 is an iron-binding protein that modulates iron homeostasis in cancer cells.

A genome-centric view of the role of the Acropora kenti microbiome in coral health and resilience

Microbial diversity has been extensively explored in reef-building corals. However, the functional roles of coral-associated microorganisms remain poorly elucidated. Here, we recover 191 bacterial and 10 archaeal metagenome-assembled genomes (MAGs) from the coral Acropora kenti (formerly A. tenuis) and adjacent seawater, to identify microbial functions and metabolic interactions within the holobiont. We show that 82 MAGs were specific to the A. kenti holobiont, including members of the Pseudomonadota, Bacteroidota, and Desulfobacterota. A. kenti-specific MAGs displayed significant differences in their genomic features and functional potential relative to seawater-specific MAGs, with a higher prevalence of genes involved in host immune system evasion, nitrogen and carbon fixation, and synthesis of five essential B-vitamins. We find a diversity of A. kenti-specific MAGs encode the biosynthesis of essential amino acids, such as tryptophan, histidine, and lysine, which cannot be de novo synthesised by the host or Symbiodiniaceae. Across a water quality gradient spanning 2° of latitude, A. kenti microbial community composition is correlated to increased temperature and dissolved inorganic nitrogen, with corresponding enrichment in molecular chaperones, nitrate reductases, and a heat-shock protein. We reveal mechanisms of A. kenti-microbiome-symbiosis on the Great Barrier Reef, highlighting the interactions underpinning the health of this keystone holobiont.

Copper in Cancer: from transition metal to potential target

In recent years, with the continuous in-depth exploration of the molecular mechanisms of tumorigenesis, numerous potential new targets for cancer treatment have been identified, some of which have been further developed in clinical practice and have produced positive outcomes. Notably, researchers' initial motivation for studying copper metabolism in cancer stems from the fact that copper is a necessary trace element for organisms and is closely connected to body growth and metabolism. Moreover, over the past few decades, considerable progress has been made in understanding the molecular processes and correlations between copper and cancer. Certain achievements have been made in the development and use of relevant clinical medications. The concept of "cuproptosis," a novel concept that differs from previous forms of cell death, was first proposed by a group of scientists last year, offering fresh perspectives on the targeting capabilities of copper in the treatment of cancer. In this review, we introduced the fundamental physiological functions of copper, the key components of copper metabolism, and a summary of the current research contributions on the connection between copper and cancer. In addition, the development of new copper-based nanomaterials and their associated mechanisms of action are discussed. Finally, we described how the susceptibility of cancer cells to this metallic nutrition could be leveraged to further improve the existing cancer treatment paradigm in the new setting.

The strategic involvement of IRS in cancer progression

Insulin Receptor Substrate (IRS), an intracellular molecule devoid of an intrinsic kinase activity, is activated upon binding to IR which thereby works as a scaffold, organizing all signaling complexes and initiating the signaling process downstream. The level of IRS proteins and their stability in the cell is mostly maintained through the phosphorylation status of their tyrosine and serine residues. IRS is positively regulated by phosphorylation of its Tyr residues whereas a Ser residue phosphorylation attenuates it, although there exist some exceptions as well. Other post-translational modifications like O-linked glycosylation, N-linked glycosylation and acetylation also play a prominent role in IRS regulation. Since the discovery of the Warburg effect, people have been curious to find out all possible signaling networks and molecules that could lead to cancer and no doubt, the insulin signaling pathway is identified as one such pathway, which is highly deregulated in cancers. Eminent studies reveal that IRS is a pertinent regulator of cancer and is highly overexpressed in the five most commonly occurring cancers namely- Prostate, Ovarian, Breast, Colon and Lung cancers. IRS1 and IRS2 family members are actively involved in the progression, invasion and metastasis of these cancers. Recently, less studied IRS4 has also emerged as a contributor in ovarian, breast, colorectal and lung cancer, but no such studies related to IRS4 are found in Prostate cancer. The involvement of other IRS family members in cancer is still undiscovered and so paves the way for further exploration. This review is a time-lapse study of IRSs in the context of cancer done over the past two decades and it highlights all the major discoveries made till date, in these cancers from the perspective of IRS.

MEMO1 Is Required for Ameloblast Maturation and Functional Enamel Formation

Coordinated mineralization of soft tissue is central to organismal form and function, while dysregulated mineralization underlies several human pathologies. Oral epithelial-derived ameloblasts are polarized, secretory cells responsible for generating enamel, the most mineralized substance in the human body. Defects in ameloblast development result in enamel anomalies, including amelogenesis imperfecta. Identifying proteins critical in ameloblast development can provide insight into specific pathologies associated with enamel-related disorders or, more broadly, mechanisms of mineralization. Previous studies identified a role for MEMO1 in bone mineralization; however, whether MEMO1 functions in the generation of additional mineralized structures remains unknown. Here, we identify a critical role for MEMO1 in enamel mineralization. First, we show that Memo1 is expressed in ameloblasts and, second, that its conditional deletion from ameloblasts results in enamel defects, characterized by a decline in mineral density and tooth integrity. Histology revealed that the mineralization defects in Memo1 mutant ameloblasts correlated with a disruption in ameloblast morphology. Finally, molecular profiling of ameloblasts and their progenitors in Memo1 oral epithelial mutants revealed a disruption to cytoskeletal-associated genes and a reduction in late-stage ameloblast markers, relative to controls. Collectively, our findings integrate MEMO1 into an emerging network of molecules important for ameloblast development and provide a system to further interrogate the relationship of cytoskeletal and amelogenesis-related defects.

Copper homeostasis and cuproptosis in tumor pathogenesis and therapeutic strategies

Copper is an indispensable micronutrient for the development and replication of all eukaryotes, and its redox properties are both harmful and beneficial to cells. An imbalance in copper homeostasis is thought to be involved in carcinogenesis. Importantly, cancer cell proliferation, angiogenesis, and metastasis cannot be separated from the effects of copper. Cuproposis is a copper-dependent form of cell death that differs from other existing modalities of regulatory cell death. The role of cuproptosis in the pathogenesis of the nervous and cardiovascular systems has been widely studied; however, its impact on malignant tumors is yet to be fully understood from a clinical perspective. Exploring signaling pathways related to cuproptosis will undoubtedly provide a new perspective for the development of anti-tumor drugs in the future. Here, we systematically review the systemic and cellular metabolic processes of copper and the regulatory mechanisms of cuproptosis in cancer. In addition, we discuss the possibility of targeting copper ion drugs to prolong the survival of cancer patients, with an emphasis on the most representative copper ionophores and chelators. We suggest that attention should be paid to the potential value of copper in the treatment of specific cancers.

Renal FGF23 signaling depends on redox protein Memo1 and promotes orthovanadate-sensitive protein phosphotyrosyl phosphatase activity

Memo1 deletion in mice causes premature aging and an unbalanced metabolism partially resembling Fgf23 and Klotho loss-of-function animals. We report a role for Memo's redox function in renal FGF23-Klotho signaling using mice with postnatally induced Memo deficiency in the whole body (cKO). Memo cKO mice showed impaired FGF23-driven renal ERK phosphorylation and transcriptional responses. FGF23 actions involved activation of oxidation-sensitive protein phosphotyrosyl phosphatases in the kidney. Redox proteomics revealed excessive thiols of Rho-GDP dissociation inhibitor 1 (Rho-GDI1) in Memo cKO, and we detected a functional interaction between Memo's redox function and oxidation at Rho-GDI1 Cys79. In isolated cellular systems, Rho-GDI1 did not directly affect FGF23-driven cell signaling, but we detected disturbed Rho-GDI1 dependent small Rho-GTPase protein abundance and activity in the kidney of Memo cKO mice. Collectively, this study reveals previously unknown layers in the regulation of renal FGF23 signaling and connects Memo with the network of small Rho-GTPases.

WD repeat protein 54-mediator of ErbB2-driven cell motility 1 axis promotes bladder cancer tumorigenesis and metastasis and impairs chemosensitivity

One of the most abundant protein-protein interaction domains in the human proteome is the WD40 repeat (WDR) domain. A Gene Expression Omnibus dataset revealed 37 differentially expressed WDR domain genes in bladder cancer (BC). WD repeat domain 54 (WDR54), an upregulated WDR domain gene, was selected for further investigation. Sixty pairs of frozen BC tumor and non-malignant bladder tissues and 83 paraffin-embedded BC tissue specimens were obtained. Loss-/gain-of-function experiments were carried out using BC and xenograft tumor models. WDR54 was overexpressed in BC cells, and its high expression was linked to tumor stage and lymph node metastases in patients. WDR54 contributed to the tumorigenesis and metastasis of BC and impaired its chemosensitivity. WDR54 prevented the degradation and ubiquitination of the mediator of ErbB2-driven cell motility 1 (MEMO1). WDR54 also promoted the interaction between MEMO1 and insulin receptor substrate 1 (IRS1) and activated the IRS1/AKT/β-catenin pathway in BC cells. Particularly, WDR54 depended on MEMO1 to exert its biological functions. Our study demonstrated the relevance of WDR54 in BC and provides insight into the molecular mechanism underlying BC.

UHMK1 is a novel splicing regulatory kinase

The U2AF Homology Motif Kinase 1 (UHMK1) is the only kinase that contains the U2AF homology motif, a common protein interaction domain among splicing factors. Through this motif, UHMK1 interacts with the splicing factors SF1 and SF3B1, known to participate in the 3' splice site recognition during the early steps of spliceosome assembly. Although UHMK1 phosphorylates these splicing factors in vitro, the involvement of UHMK1 in RNA processing has not previously been demonstrated. Here, we identify novel putative substrates of this kinase and evaluate UHMK1 contribution to overall gene expression and splicing, by integrating global phosphoproteomics, RNA-seq, and bioinformatics approaches. Upon UHMK1 modulation, 163 unique phosphosites were differentially phosphorylated in 117 proteins, of which 106 are novel potential substrates of this kinase. Gene Ontology analysis showed enrichment of terms previously associated with UHMK1 function, such as mRNA splicing, cell cycle, cell division, and microtubule organization. The majority of the annotated RNA-related proteins are components of the spliceosome but are also involved in several steps of gene expression. Comprehensive analysis of splicing showed that UHMK1 affected over 270 alternative splicing events. Moreover, splicing reporter assay further supported UHMK1 function on splicing. Overall, RNA-seq data demonstrated that UHMK1 knockdown had a minor impact on transcript expression and pointed to UHMK1 function in epithelial-mesenchymal transition. Functional assays demonstrated that UHMK1 modulation affects proliferation, colony formation, and migration. Taken together, our data implicate UHMK1 as a splicing regulatory kinase, connecting protein regulation through phosphorylation and gene expression in key cellular processes.

AKT-driven epithelial-mesenchymal transition is affected by copper bioavailability in HER2 negative breast cancer cells via a LOXL2-independent mechanism

BACKGROUND

The main mechanism underlying cancer dissemination is the epithelial to mesenchymal transition (EMT). This process is orchestrated by cytokines like TGFβ, involving "non-canonical" AKT- or STAT3-driven pathways. Recently, the alteration of copper homeostasis seems involved in the onset and progression of cancer.

METHODS

We expose different breast cancer cell lines, including two triple negative (TNBC) ones, an HER2 enriched and one cell line representative of the Luminal A molecular subtype, to short- or long-term copper-chelation by triethylenetetramine (TRIEN). We analyse changes in the expression of EMT markers (E-cadherin, fibronectin, vimentin and αSMA), in the levels and activity of extracellular matrix components (LOXL2, fibronectin and MMP2/9) and of copper homeostasis markers by Western blot analyses, immunofluorescence, enzyme activity assays and RT-qPCR. Boyden Chamber and wound healing assays revealed the impact of copper chelation on cell migration. Additionally, we explored whether perturbation of copper homeostasis affects EMT prompted by TGFβ. Metabolomic and lipidomic analyses were applied to search the effects of copper chelation on the metabolism of breast cancer cells. Finally, bioinformatics analysis of data on breast cancer patients obtained from different databases was employed to correlate changes in kinases and copper markers with patients' survival.

RESULTS

Remarkably, only HER2 negative breast cancer cells differently responded to short- or long-term exposure to TRIEN, initially becoming more aggressive but, upon prolonged exposure, retrieving epithelial features, reducing their invasiveness. This phenomenon may be related to the different impact of the short and prolonged activation of the AKT kinase and to the repression of STAT3 signalling. Bioinformatics analyses confirmed the positive correlation of breast cancer patients' survival with AKT activation and up-regulation of CCS. Eventually, metabolomics studies demonstrate a prevalence of glycolysis over mitochondrial energetic metabolism and of lipidome changes in TNBC cells upon TRIEN treatment.

CONCLUSIONS

We provide evidence of a pivotal role of copper in AKT-driven EMT activation, acting independently of HER2 in TNBC cells and via a profound change in their metabolism. Our results support the use of copper-chelators as an adjuvant therapeutic strategy for TNBC.

Copper-Dependent Kinases and Their Role in Cancer Inception, Progression and Metastasis

In recent years, copper function has been expanded beyond its consolidated role as a cofactor of enzyme catalysis. Recent papers have demonstrated a new dynamic role for copper in the regulation of cell signaling pathways through direct interaction with protein kinases, modulating their activity. The activation of these pathways is exacerbated in cancer cells to sustain the different steps of tumor growth and dissemination. This review will focus on a novel proposed role for the transition metal copper as a regulator of cell signaling pathways through direct interaction with known protein kinases, which exhibit binding domains for this metal. Activation of these pathways in cancer cells supports both tumor growth and dissemination. In addition to the description of the results recently reported in the literature on the subject, relevance will be given to the possibility of controlling the cellular levels of copper and its homeostatic regulators. Overall, these findings may be of central relevance in order to propose copper and its homeostatic regulators as possible targets for novel therapies, which may act synergistically to those already existing to control cancer growth and dissemination.

Repression of Memo1, a Novel Target of Human Papillomavirus Type 16 E7, Increases Cell Proliferation in Cervical Cancer Cells

Human papillomavirus (HPV)-induced carcinogenesis is associated with unregulated expression of the oncoproteins E6 and E7. HPV E7 is a viral protein that lacks enzymatic activity; however, it can target several cellular proteins to induce cell transformation and promote uncontrolled proliferation. Although several E7 targets have been described, there are still gaps in the understanding of how this oncoprotein drives cells toward malignancy. Here, using a small HPV type 16 (HPV16) E7 peptide in a proteomic approach, we report Memo1 as a new E7 binding partner, interacting through the aspartic and glutamic acid residues (E80 and D81) in the C-terminal region of HPV16 E7. Furthermore, we demonstrate that HPV16 E7 targets Memo1 for proteasomal degradation through a Cullin2-dependent mechanism. In addition, we show that overexpression of Memo1 decreases cell transformation and proliferation and that reduction of Memo1 levels correlate with activation of Akt and an increase in invasion of HPV-positive cervical cancer cell lines. Our results show a novel HPV E7 interacting partner and describe novel functions of Memo1 in the context of HPV-induced malignancy. IMPORTANCE Although numerous targets have been reported to interact with the HPV E7 oncoprotein, the mechanisms involved in HPV-induced carcinogenesis and the maintenance of cell transformation are still lacking. Here, through pulldown assays using a peptide encompassing the C-terminal region of HPV16 E7, we report Memo1 as a novel E7 interactor. High levels of Memo1 correlated with reduced cell proliferation and, concordantly, knockdown of Memo1 resulted in Akt activation in HPV-positive cell lines. These results highlight new mechanisms used by HPV oncoproteins to modulate proliferation pathways in cervical cancer cells and increase our understanding of the link between Memo1 protein and cancer.

Memo1 binds reduced copper ions, interacts with copper chaperone Atox1, and protects against copper-mediated redox activity in vitro

Since many proteins depend on copper ions for functionality, it is not surprising that cancer cells have a high demand for copper. Still, free copper ions are toxic as they can potentially catalyze the formation of harmful reactive oxygen species (ROS) upon coupling redox cycling between Cu(I) and Cu(II) with reduction of O₂. Here, we investigated copper binding to Memo1, an oncogenic protein linked to cancer. We demonstrate that Memo1 coordinates reduced but not oxidized copper ions, thereby preventing the copper ions from acting as redox catalysts for ROS generation. As Memo1 is a putative target for the treatment of cancer, it is of importance to identify its binding partners (e.g., metal ions) and the functional consequences of such interactions.

The protein mediator of ERBB2-driven cell motility 1 (Memo1) is connected to many signaling pathways that play key roles in cancer. Memo1 was recently postulated to bind copper (Cu) ions and thereby promote the generation of reactive oxygen species (ROS) in cancer cells. Since the concentration of Cu as well as ROS are increased in cancer cells, both can be toxic if not well regulated. Here, we investigated the Cu-binding capacity of Memo1 using an array of biophysical methods at reducing as well as oxidizing conditions in vitro. We find that Memo1 coordinates two reduced Cu (Cu(I)) ions per protein, and, by doing so, the metal ions are shielded from ROS generation. In support of biological relevance, we show that the cytoplasmic Cu chaperone Atox1, which delivers Cu(I) in the secretory pathway, can interact with and exchange Cu(I) with Memo1 in vitro and that the two proteins exhibit spatial proximity in breast cancer cells. Thus, Memo1 appears to act as a Cu(I) chelator (perhaps shuttling the metal ion to Atox1 and the secretory path) that protects cells from Cu-mediated toxicity, such as uncontrolled formation of ROS. This Memo1 functionality may be a safety mechanism to cope with the increased demand of Cu ions in cancer cells.

Emerging roles of the copper-CTR1 axis in tumorigenesis

Physiological roles of copper in metabolic homeostasis have been well established, however, whether and how copper is dysregulated in tumors and contributes to tumorigenesis are not recapitulated. Here, we comprehensively summarize the potential origins of copper accumulation in diseases especially in cancers by dysregulating copper transporter 1 (CTR1) or ATPase copper transporting alpha/beta (ATP7A/B) and further demonstrate the underlying mechanism of copper contributing to tumorigenesis. Specifically, in addition to modulating reactive oxygen species (ROS), angiogenesis, immune response, and metabolic homeostasis, copper recently has drawn more attention by directly binding to oncoproteins such as MEK, ULK, Memo, and PDK1 to activate distinct oncogenic signals and account for tumorigenesis. In the end, we disclose the emerging applications of copper in cancer diagnosis and highlight the promising strategies to target the copper-CTR1 axis for cancer therapies.

LncRNA cancer susceptibility 20 regulates the metastasis of human gastric cancer cells via the miR-143-5p/MEMO1 molecular axis

BACKGROUND

Gastric cancer (GC) is considered as one of the most widespread malignancies. Emerging evidence has shown that lncRNAs can function as important oncogenes or tumor suppressors during GC progression.

AIM

To investigate the effect and mechanism of lncRNA cancer susceptibility 20 (CASC20) in the proliferation and metastasis of GC cells.

METHODS

Data mining and clinical samples were used to evaluate the expression of CASC20 in GC and adjacent tissues. CASC20 was down-regulated in GC cells by short-interfering RNA. Cell proliferation was evaluated by CCK-8 assay, and cell migration and invasion were detected by wound healing and Transwell assays. The expressions of proteins related to epithelial-mesenchymal transition were detected by western blot assay.

RESULTS

The expression of CASC20 was increased in GC tumor tissues and various GC cell lines. High CASC20 expression was correlated with a high risk of lymphatic metastasis and poor prognosis in GC patients. In vitro assays showed that silencing CASC20 reduced cell proliferation, migration, and invasion in GC cells. Mechanistic studies revealed that CASC20 exhibits oncogenic functions by regulating MEMO1 expression through competitive endogenous binding to miR-143-5p, leading to induction of epithelial-mesenchymal transition.

CONCLUSION

Our findings indicate that CASC20 serves as a tumor promoter by regulating metastasis in GC via the miR-143-5p/MEMO1 axis. CASC20 may be a potential therapeutic target for GC.

MicroRNA-7 regulates insulin signaling pathway by targeting IRS1, IRS2, and RAF1 genes in gestational diabetes mellitus

BACKGROUND

Small non-coding micro RNAs (miRNAs) are indicated in various metabolic processes and play a critical role in disease pathology, including gestational diabetes mellitus (GDM).

OBJECTIVE

The purpose of this study was to examine the altered expression of miRNAs and their target genes in placental tissue (PL), cord blood (CB), and maternal blood (MB) of matched non-glucose tolerant (NGT) and GDM mother.

METHODS

In a case-control study, micro-RNA was quantified from forty-five serum (MB n = 15, CB n = 15, and PL n = 15) and matched placental tissue using stem-loop RT-qPCR followed by target prediction, network construction and functional and pathways enrichment analysis. Further, target genes were verified in-vitro through transfection and RT-qPCR.

RESULTS

Five miRNAs, namely hsa-let 7a-5P, hsa-miR7-5P, hsa-miR9-5P, hsa-miR18a-5P, and hsa-miR23a-3P were significantly over-expressed (p < 0.05) in all three samples namely PL, CB, and MB of GDM patients. However, the sample-wise comparison reveals higher expression of miRNA 7 in MB while lowest in CB than control. Furthermore, a comparison of fold change expression of target genes discloses a lower expression of IRS1, IRS2, and RAF1 in MB while comparatively higher expression of NRAS in MB and CB. In-vitro validation reveals lower expression of IRS1/2 and RAF1 in response to overexpression of miR-7 and vice-versa. Thus it is evident that increased miRNA7 expression causes down-regulation of its target genes IRS1, IRS2, and RAF1 in GDM mother compared to control. Further, target prediction, pathway enrichment, and hormone analysis (significantly higher FSH & LH in MB of GDM compared to NGT) revealed the insulin signaling, inflammatory and GnRH signaling as major pathways regulated by miRNA7.

CONCLUSIONS

Thus, an elevated level of miRNA7 may be associated with the progression of GDM by altering the multiple pathways like insulin, GnRH, and inflammatory signaling pathways via targeting IRS1, IRS2, and RAF1, implicating a new therapeutic target for GDM.

Minerals and Cancer: Overview of the Possible Diagnostic Value

Simple Summary

Minerals are important but often overlooked compounds that are required for a variety of cellular biochemical processes and pathways that regulate cell proliferation. Their dietary imbalance, which is becoming more common in the diets of industrialized countries, is linked to an increased risk of cancer. The current review will present some of the most important minerals for human physiology and evaluate their potential application as cancer biomarkers.

Abstract

Cancer is the second leading cause of death worldwide and is expected to increase by one-third over the next two decades, in parallel with the growing proportion of the elderly population. Treatment and control of cancer incidence is a global issue. Since there is no clear way to prevent or cure this deadly malignancy, diagnostic, predictive, and prognostic markers for oncological diseases are of great therapeutic value. Minerals and trace elements are important micronutrients for normal physiological function of the body. They are abundant in natural food sources and are regularly included in dietary supplements whereas highly processed industrial food often contains reduced or altered amounts of them. In modern society, the daily intake, storage pools, and homeostasis of these micronutrients are dependent on certain dietary habits and can be thrown out of balance by malignancies. The current work summarizes the data on minerals and trace elements associated with abnormal accumulation or depletion states in tumor patients and discusses their value as potential tumor-associated biomarkers that could be introduced into cancer therapy.

Knockdown of circRNA-Memo1 Reduces Hypoxia/Reoxygenation Injury in Human Brain Endothelial Cells Through miRNA-17-5p/SOS1 Axis

Circ-Memo1 has been proved to be upregulated in ischemia-reperfusion induced acute injury of kidney tissues. However, the potential role of circ-Memo1 in cerebral hypoxia/reoxygenation (H/R) injury is still unclear.Blood samples were collected from 25 ischemic stroke patients and 25 healthy controls. To construct the H/R model, human brain microvascular endothelial cells (HBMVECs) were cultured under the hypoxic condition, followed by reoxygenation. Cell viability was analyzed by MTT assay. Flow cytometry was carried out to examine cell apoptosis. The level of malondialdehyde (MDA) and the activity of superoxide dismutase (SOD) were measured by MDA and SOD assay kits, respectively. The levels of TNF-α, IL-1β, and IL-6 were determined by enzyme-linked immunosorbent assay (ELISA). Dual-luciferase reporter gene detection was employed to verify the binding relationships between circ-Memo1, miR-17-5p, and SOS1.Circ-Memo1 and SOS1 expressions were increased, and miR-17-5p expression was reduced in ischemic stroke patients. Circ-Memo1 silencing promoted cell viability, inhibited the activation of ERK/NF-κB signaling pathway, reduced oxidative stress and inflammatory response, and inhibited cell apoptosis. Moreover, miR-17-5p functioned as the sponge of circ-Memo1, and SOS1 was identified as the target of miR-17-5p. The protective effect of circ-Memo1 knockdown on cell injury after H/R treatment was weakened by miR-17-5p inhibition.Knockdown of circ-Memo1 alleviated H/R injury of HBMVEC cells by regulating the miR-17-5p/SOS1 axis, indicating that circ-Memo1 might be a potential treatment target for cerebral H/R injury.

Insulin receptor substrate-1 and dishevelled 2 are negatively regulated by microRNA-144 and inhibit nasopharyngeal carcinoma cell malignancy

Insulin receptor substrate-1 (IRS-1) is reported to play a critical role in the development, progression, invasion and metastasis of several types of tumors and is abnormally expressed in nasopharyngeal carcinoma (NPC). Although IRS-1 is predicted to be targeted by microRNA (miR)-144, the biological roles and potential mechanisms of miR-144 in NPC remain unclear. In the present study, the expression levels of miR-144 and IRS-1 in several NPC cell lines were first examined, and found that they were negatively correlated. Following the introduction of the miR-144 mimic, IRS-1 was downregulated at the protein level without affecting the mRNA level. The Cell Counting Kit-8 assay showed that the miR-144 mimic and siRNA targeting IRS-1 mRNA significantly decreased cell proliferation by arresting the cell cycle at the G₁/G₀ phase. The malignant behaviours of NPC cell lines, including migration, invasion and tumour formation in soft agar, were then analyzed after regulating miR-144 levels; as expected, the results showed that both the miR-144 mimic and siIRS-1 decreased these malignant behaviours. Furthermore, the downregulation of IRS-1 by miR-144 decreased the expression level of dishevelled 2 (Dvl2) protein without affecting its mRNA level, and Dvl2 overexpression abolished the inhibitory effect of the miR-144 mimic in NPC, indicating that miR-144 potentially regulates NPC by indirectly regulating Dvl2. Taken together, the present study results suggest that miR-144 acts as a tumour suppressor in NPC cell lines by regulating IRS-1 and Dvl2, which indicates that it is a potential therapeutic target for NPC treatment.

The molecular and cellular basis of copper dysregulation and its relationship with human pathologies

Copper (Cu) is an essential micronutrient required for the activity of redox-active enzymes involved in critical metabolic reactions, signaling pathways, and biological functions. Transporters and chaperones control Cu ion levels and bioavailability to ensure proper subcellular and systemic Cu distribution. Intensive research has focused on understanding how mammalian cells maintain Cu homeostasis, and how molecular signals coordinate Cu acquisition and storage within organs. In humans, mutations of genes that regulate Cu homeostasis or facilitate interactions with Cu ions lead to numerous pathologic conditions. Malfunctions of the Cu⁺ -transporting ATPases ATP7A and ATP7B cause Menkes disease and Wilson disease, respectively. Additionally, defects in the mitochondrial and cellular distributions and homeostasis of Cu lead to severe neurodegenerative conditions, mitochondrial myopathies, and metabolic diseases. Cu has a dual nature in carcinogenesis as a promotor of tumor growth and an inducer of redox stress in cancer cells. Cu also plays role in cancer treatment as a component of drugs and a regulator of drug sensitivity and uptake. In this review, we provide an overview of the current knowledge of Cu metabolism and transport and its relation to various human pathologies.

Identification of Phenazine-Based MEMO1 Small-Molecule Inhibitors: Virtual Screening, Fluorescence Polarization Validation, and Inhibition of Breast Cancer Migration

Phosphorylation-dependent protein-protein interactions play a significant role in biological signaling pathways; therefore, small molecules that are capable of influencing these interactions can be valuable research tools and have potential as pharmaceutical agents. MEMO1 (mediator of ErbB2-cell driven motility) is a phosphotyrosine-binding protein that interacts with a variety of protein partners and has been found to be upregulated in breast cancer patients. Herein, we report the first small-molecule inhibitors of MEMO1 interactions identified through a virtual screening platform and validated in a competitive fluorescence polarization assay. Initial structure-activity relationships have been investigated for these phenazine-core inhibitors and the binding sites have been postulated using molecular dynamics simulations. The most potent biochemical inhibitor is capable of disrupting the large protein interface with a K_I of 2.7 μm. In addition, the most promising phenazine core compounds slow the migration of breast cancer cell lines in a scratch assay.

miR-219a-1 inhibits colon cancer cells proliferation and invasion by targeting MEMO1

Colon cancer is the third most common cancer worldwide. Many miRNAs have been reported to be involved in colon cancer progression. However, there are only a few studies on the role of miR-219a-1 in colon cancer, and the molecular mechanisms involved remain unclear. The aim of this study was to investigate the miR-219a-1 level in patients with colon cancer and to explore both the effects and regulatory mechanisms of miR-219a-1 in the malignancy of colon cancer cells. Real-time PCR and western blot analysis were used to analyze the expression levels of miR-219a-1 and mediator of ErbB2-driven cell motility 1. Cell Counting Kit-8, transwell and wound-healing assays were performed to investigate the malignant ability of colon cancer cells. A luciferase assay was performed to explore whether miR-219a-1 could directly bind to 3ʹ-UTR region of MEMO1. miR-219a-1 was found to be downregulated in colon cancer cell lines and in patients with colon cancer. Additionally, miR-219a-1 could inhibit colon cancer cell proliferation, invasion and migration. We identified MEMO1 as a novel potential target gene of miR-219a-1. Luciferase assays showed that miR-219a-1 could directly bind to 3′-UTR of MEMO1. Overexpression of miR-219a-1 in colon cancer cells could inhibit the expression of MEMO1. Furthermore, MEMO1 was upregulated in patients with colon cancer, which was inversely correlated with miR-219a-1 levels. In conclusion, our study revealed that miR-219a-1 exerts anti-tumor effects and regulates colon cancer cell proliferation, invasion and migration by targeting MEMO1, suggesting that miR-219a-1 could act as a therapeutic target in colon cancer.

Finding MEMO-Emerging Evidence for MEMO1's Function in Development and Disease

Although conserved throughout animal kingdoms, the protein encoded by the gene Mediator of ERBB2 Driven Cell Motility 1 or MEMO1, has only recently come into focus. True to its namesake, MEMO1 first emerged from a proteomic screen of molecules bound to the ERBB2 receptor and was found to be necessary for efficient cell migration upon receptor activation. While initially placed within the context of breast cancer metastasis—a pathological state that has provided tremendous insight into MEMO1′s cellular roles—MEMO1′s function has since expanded to encompass additional cancer cell types, developmental processes during embryogenesis and homeostatic regulation of adult organ systems. Owing to MEMO1′s deep conservation, a variety of model organisms have been amenable to uncovering biological facets of this multipurpose protein; facets ranging from the cellular (e.g., receptor signaling, cytoskeletal regulation, redox flux) to the organismal (e.g., mineralization and mineral homeostasis, neuro/gliogenesis, vasculogenesis) level. Although these facets emerge at the intersection of numerous biological and human disease processes, how and if they are interconnected remains to be resolved. Here, we review our current understanding of this ‘enigmatic’ molecule, its role in development and disease and open questions emerging from these previous studies.

Copper metabolism as a unique vulnerability in cancer

The last 25 years have witnessed tremendous progress in identifying and characterizing proteins that regulate the uptake, intracellular trafficking and export of copper. Although dietary copper is required in trace amounts, sufficient quantities of this metal are needed to sustain growth and development in humans and other mammals. However, copper is also a rate-limiting nutrient for the growth and proliferation of cancer cells. Oral copper chelators taken with food have been shown to confer anti-neoplastic and anti-metastatic benefits in animals and humans. Recent studies have begun to identify specific roles for copper in pathways of oncogenic signaling and resistance to anti-neoplastic drugs. Here, we review the general mechanisms of cellular copper homeostasis and discuss roles of copper in cancer progression, highlighting metabolic vulnerabilities that may be targetable in the development of anticancer therapies.

A Genome-scale CRISPR Screen Identifies the ERBB and mTOR Signaling Networks as Key Determinants of Response to PI3K Inhibition in Pancreatic Cancer

KRAS mutation is a key driver of pancreatic cancer and PI3K pathway activity is an additional requirement for Kras-induced tumorigenesis. Clinical trials of PI3K pathway inhibitors in pancreatic cancer have shown limited responses. Understanding the molecular basis for this lack of efficacy may direct future treatment strategies with emerging PI3K inhibitors. We sought new therapeutic approaches that synergize with PI3K inhibitors through pooled CRISPR modifier genetic screening and a drug combination screen. ERBB family receptor tyrosine kinase signaling and mTOR signaling were key modifiers of sensitivity to alpelisib and pictilisib. Inhibition of the ERBB family or mTOR was synergistic with PI3K inhibition in spheroid, stromal cocultures. Near-complete loss of ribosomal S6 phosphorylation was associated with synergy. Genetic alterations in the ERBB-PI3K signaling axis were associated with decreased survival of patients with pancreatic cancer. Suppression of the PI3K/mTOR axis is potentiated by dual PI3K and ERBB family or mTOR inhibition. Surprisingly, despite the presence of oncogenic KRAS, thought to bestow independence from receptor tyrosine kinase signaling, inhibition of the ERBB family blocks downstream pathway activation and synergizes with PI3K inhibitors. Further exploration of these therapeutic combinations is warranted for the treatment of pancreatic cancer.

Influence of pre-operative oral carbohydrate loading vs. standard fasting on tumor proliferation and clinical outcome in breast cancer patients ─ a randomized trial

Background

Conflicting results have been reported on the influence of carbohydrates in breast cancer.

Objective

To determine the influence of pre-operative per-oral carbohydrate load on proliferation in breast tumors.

Design

Randomized controlled trial.

Setting

University hospital with primary and secondary care functions in South-West Norway.

Patients

Sixty-one patients with operable breast cancer from a population-based cohort.

Intervention

Per-oral carbohydrate load (preOp™) 18 and 2–4 h before surgery (n = 26) or standard pre-operative fasting with free consumption of tap water (n = 35).

Measurements

The primary outcome was post-operative tumor proliferation measured by the mitotic activity index (MAI). The secondary outcomes were changes in the levels of serum insulin, insulin-c-peptide, glucose, IGF-1, and IGFBP3; patients’ well-being, and clinical outcome over a median follow-up of 88 months (range 33–97 months).

Results

In the estrogen receptor (ER) positive subgroup (n = 50), high proliferation (MAI ≥ 10) occurred more often in the carbohydrate group (CH) than in the fasting group (p = 0.038). The CH group was more frequently progesterone receptor (PR) negative (p = 0.014). The CH group had a significant increase in insulin (+ 24.31 mIE/L, 95% CI 15.34 mIE/L to 33.27 mIE/L) and insulin c-peptide (+ 1.39 nM, 95% CI 1.03 nM to 1.77 nM), but reduced IGFBP3 levels (− 0.26 nM; 95% CI − 0.46 nM to − 0.051 nM) compared to the fasting group. CH-intervention ER-positive patients had poorer relapse-free survival (73%) than the fasting group (100%; p = 0.012; HR = 9.3, 95% CI, 1.1 to 77.7). In the ER-positive patients, only tumor size (p = 0.021; HR = 6.07, 95% CI 1.31 to 28.03) and the CH/fasting subgrouping (p = 0.040; HR = 9.30, 95% CI 1.11 to 77.82) had independent prognostic value. The adverse clinical outcome of carbohydrate loading occurred only in T2 patients with relapse-free survival of 100% in the fasting group vs. 33% in the CH group (p = 0.015; HR = inf). The CH group reported less pain on days 5 and 6 than the control group (p <  0.001) but otherwise exhibited no factors related to well-being.

Limitation

Only applicable to T2 tumors in patients with ER-positive breast cancer.

Conclusions

Pre-operative carbohydrate load increases proliferation and PR-negativity in ER-positive patients and worsens clinical outcome in ER-positive T2 patients.

Trial registration

CliniTrials.gov; NCT03886389. Retrospectively registered March 22, 2019.

Copper homeostasis as target of both consolidated and innovative strategies of anti-tumor therapy

BACKGROUND

Copper was reported to be involved in the onset and progression of cancer. Proteins in charge of copper uptake and distribution, as well as cuproenzymes, are altered in cancer. More recently, proteins involved in signaling cascades, regulating cell proliferation, and anti-apoptotic protein factors were found to interact with copper. Therefore, therapeutic strategies using copper complexing molecules have been proposed for cancer therapy and used in clinical trials.

OBJECTIVES

This review will focus on novel findings about the involvement of copper and cupro-proteins in cancer dissemination process, epithelium to mesenchymal transition and vascularization. Particularly, implication of well-established (e.g. lysil oxidase) or newly identified copper-binding proteins (e.g. MEMO1), as well as their interplay, will be discussed. Moreover, we will describe recently synthesized copper complexes, including plant-derived ones, and their efficacy in contrasting cancer development.

CONCLUSIONS

The research on the involvement of copper in cancer is still an open field. Further investigation is required to unveil the mechanisms involved in copper delivery to the novel copper-binding proteins, which may identify other possible gene and protein targets for cancer therapy.

Etiology of Metabolic Syndrome and Dietary Intervention

The growing prevalence of metabolic syndrome (MetS) in the U.S. and even worldwide is becoming a serious health problem and economic burden. MetS has become a crucial risk factor for the development of type 2 diabetes mellitus (T2D) and cardiovascular diseases (CVD). The rising rates of CVD and diabetes, which are the two leading causes of death, simultaneously exist. To prevent the progression of MetS to diabetes and CVD, we have to understand how MetS occurs and how it progresses. Too many causative factors interact with each other, making the investigation and treatment of metabolic syndrome a very complex issue. Recently, a number of studies were conducted to investigate mechanisms and interventions of MetS, from different aspects. In this review, the proposed and demonstrated mechanisms of MetS pathogenesis are discussed and summarized. More importantly, different interventions are discussed, so that health practitioners can have a better understanding of the most recent research progress and have available references for their daily practice.

BRCA1-IRIS promotes human tumor progression through PTEN blockade and HIF-1α activation

Spontaneous overexpression of endogenous IRIS, an alternatively spliced product of the tumor suppressor gene BRCA1, allows it to function as an oncoprotein that stimulates a potentially lethal outcome, i.e. metastasis of human cancer cells to tissues served, in part, by the arterial circulation. It does so by suppressing phosphatase and tensin homolog (PTEN) mRNA synthesis, thereby stabilizing and activating HIF-1α in normoxic cells. Thus, this study provides a strong rationale for exploring the therapeutic value of interfering with spontaneously overexpressed IRIS function in multiple types of tumors that can naturally overexpress it.

BRCA1 is an established breast and ovarian tumor suppressor gene that encodes multiple protein products whose individual contributions to human cancer suppression are poorly understood. BRCA1-IRIS (also known as “IRIS”), an alternatively spliced BRCA1 product and a chromatin-bound replication and transcription regulator, is overexpressed in various primary human cancers, including breast cancer, lung cancer, acute myeloid leukemia, and certain other carcinomas. Its naturally occurring overexpression can promote the metastasis of patient-derived xenograft (PDX) cells and other human cancer cells in mouse models. The IRIS-driven metastatic mechanism results from IRIS-dependent suppression of phosphatase and tensin homolog (PTEN) transcription, which in turn perturbs the PI3K/AKT/GSK-3β pathway leading to prolyl hydroxylase-independent HIF-1α stabilization and activation in a normoxic environment. Thus, despite the tumor-suppressing genetic origin of IRIS, its properties more closely resemble those of an oncoprotein that, when spontaneously overexpressed, can, paradoxically, drive human tumor progression.

Molecular Signatures of the Insulin-like Growth Factor 1-mediated Epithelial-Mesenchymal Transition in Breast, Lung and Gastric Cancers

The insulin-like growth factor (IGF) system, which is constituted by the IGF-1 and IGF-2 peptide hormones, their corresponding receptors and several IGF binding proteins, is involved in physiological and pathophysiological processes. The IGF system promotes cancer proliferation/survival and its signaling induces the epithelial-mesenchymal transition (EMT) phenotype, which contributes to the migration, invasiveness, and metastasis of epithelial tumors. These cancers share two major IGF-1R signaling transduction pathways, PI3K/AKT and RAS/MEK/ERK. However, as far as we could review at this time, each type of cancer cell undergoes EMT through tumor-specific routes. Here, we review the tumor-specific molecular signatures of IGF-1-mediated EMT in breast, lung, and gastric cancers.

Differential 3' Processing of Specific Transcripts Expands Regulatory and Protein Diversity Across Neuronal Cell Types

Alternative polyadenylation (APA) regulates mRNA translation, stability, and protein localization. However, it is unclear to what extent APA regulates these processes uniquely in specific cell types. Using a new technique, cTag-PAPERCLIP, we discovered significant differences in APA between the principal types of mouse cerebellar neurons, the Purkinje and granule cells, as well as between proliferating and differentiated granule cells. Transcripts that differed in APA in these comparisons were enriched in key neuronal functions and many differed in coding sequence in addition to 3’UTR length. We characterize Memo1, a transcript that shifted from expressing a short 3’UTR isoform to a longer one during granule cell differentiation. We show that Memo1 regulates granule cell precursor proliferation and that its long 3’UTR isoform is targeted by miR-124, contributing to its downregulation during development. Our findings provide insight into roles for APA in specific cell types and establish a platform for further functional studies.

Memo interacts with c-Src to control Estrogen Receptor alpha sub-cellular localization

Understanding the complex interaction between growth factor and steroid hormone signaling pathways in breast cancer is key to identifying suitable therapeutic strategies to avoid progression and therapy resistance. The interaction between these two pathways is of paramount importance for the development of endocrine resistance. Nevertheless, the molecular mechanisms behind their crosstalk are still largely obscure. We previously reported that Memo is a small redox-active protein that controls heregulin-mediated migration of breast cancer cells. Here we report that Memo sits at the intersection between heregulin and estrogen signaling, and that Memo controls Estrogen Receptor alpha (ERα) sub-cellular localization, phosphorylation, and function downstream of heregulin and estrogen in breast cancer cells. Memo facilitates ERα and c-Src interaction, ERα Y537 phosphorylation, and has the ability to control ERα extra-nuclear localization. Thus, we identify Memo as an important key mediator between the heregulin and estrogen signaling pathways, which affects both breast cancer cell migration and proliferation.

Circulating MicroRNAs as Biomarkers of Gestational Diabetes Mellitus: Updates and Perspectives

Gestational diabetes mellitus (GDM) is defined as any degree of carbohydrate intolerance, with onset or first recognition during second or third trimester of gestation. It is estimated that approximately 7% of all pregnancies are complicated by GDM and that its prevalence is rising all over the world. Thus, the screening for abnormal glucose levels is generally recommended as a routine component of care for pregnant women. However, additional biomarkers are needed in order to predict the onset or accurately monitor the status of gestational diabetes. Recently, microRNAs, a class of small noncoding RNAs demonstrated to modulate gene expression, have been proven to be secreted by cells of origin and can be found in many biological fluids such as serum or plasma. Such feature renders microRNAs as optimal biomarkers and sensors of in situ tissue alterations. Furthermore, secretion of microRNAs via exosomes has been reported to contribute to tissue cross talk, thus potentially represents, if disrupted, a mechanistic cause of tissue/cell dysfunction in a specific disease. In this review, we summarized the recent findings on circulating microRNAs and gestational diabetes mellitus with particular focus on the potential use of microRNAs as putative biomarkers of disease as well as a potential cause of GDM complications and β cell dysfunction.

Artesunate Protects Against the Organ Injury and Dysfunction Induced by Severe Hemorrhage and Resuscitation

OBJECTIVE

To evaluate the effects of artesunate on organ injury and dysfunction associated with hemorrhagic shock (HS) in the rat.

BACKGROUND

HS is still a common cause of death in severely injured patients and is characterized by impairment of organ perfusion, systemic inflammatory response, and multiple organ failure. There is no specific therapy that reduces organ injury/dysfunction. Artesunate exhibits pharmacological actions beyond its antimalarial activity, such as anticancer, antiviral, and anti-inflammatory effects.

METHODS

Rats were submitted to HS. Mean arterial pressure was reduced to 30 mm Hg for 90 minutes, followed by resuscitation. Rats were randomly treated with artesunate (2.4 or 4.8 mg/kg i.v.) or vehicle upon resuscitation. Four hours later, parameters of organ injury and dysfunction were assessed.

RESULTS

Artesunate attenuated the multiple organ injury and dysfunction caused by HS. Pathway analysis of RNA sequencing provided good evidence to support an effect of artesunate on the Akt-survival pathway, leading to downregulation of interleukin-1 receptor-associated kinase 1. Using Western blot analysis, we confirmed that treatment of HS rats with artesunate enhanced the phosphorylation (activation) of Protein kinase B (Akt) and endothelial nitric oxide synthase and the phosphorylation (inhibition) of glycogen synthase kinase-3β (GSK-3β). Moreover, artesunate attenuated the HS-induced activation of nuclear factor kappa B and reduced the expression of proinflammatory proteins (inducible nitric oxide synthase, tumor necrosis factor-α, and interleukin 6).

CONCLUSIONS

Artesunate attenuated the organ injury/dysfunction associated with HS by a mechanism that involves the activation of the Akt-endothelial nitric oxide synthase survival pathway, and the inhibition of glycogen synthase kinase-3β and nuclear factor kappa B. A phase II clinical trial evaluating the effects of good manufacturing practice-artesunate in patients with trauma and severe hemorrhage is planned.

Roles of Copper-Binding Proteins in Breast Cancer

Copper ions are needed in several steps of cancer progression. However, the underlying mechanisms, and involved copper-binding proteins, are mainly elusive. Since most copper ions in the body (in and outside cells) are protein-bound, it is important to investigate what copper-binding proteins participate and, for these, how they are loaded with copper by copper transport proteins. Mechanistic information for how some copper-binding proteins, such as extracellular lysyl oxidase (LOX), play roles in cancer have been elucidated but there is still much to learn from a biophysical molecular viewpoint. Here we provide a summary of copper-binding proteins and discuss ones reported to have roles in cancer. We specifically focus on how copper-binding proteins such as mediator of cell motility 1 (MEMO1), LOX, LOX-like proteins, and secreted protein acidic and rich in cysteine (SPARC) modulate breast cancer from molecular and clinical aspects. Because of the importance of copper for invasion/migration processes, which are key components of cancer metastasis, further insights into the actions of copper-binding proteins may provide new targets to combat cancer.

Genetic prediction of male pattern baldness

Male pattern baldness can have substantial psychosocial effects, and it has been phenotypically linked to adverse health outcomes such as prostate cancer and cardiovascular disease. We explored the genetic architecture of the trait using data from over 52,000 male participants of UK Biobank, aged 40-69 years. We identified over 250 independent genetic loci associated with severe hair loss (P<5x10-8). By splitting the cohort into a discovery sample of 40,000 and target sample of 12,000, we developed a prediction algorithm based entirely on common genetic variants that discriminated (AUC = 0.78, sensitivity = 0.74, specificity = 0.69, PPV = 59%, NPV = 82%) those with no hair loss from those with severe hair loss. The results of this study might help identify those at greatest risk of hair loss, and also potential genetic targets for intervention.

IGF-IR signaling in epithelial to mesenchymal transition and targeting IGF-IR therapy: overview and new insights

The insulin-like growth factor-I (IGF-I) signaling induces epithelial to mesenchymal transition (EMT) program and contributes to metastasis and drug resistance in several subtypes of tumors. In preclinical studies, targeting of the insulin-like growth factor-I receptor (IGF-IR) showed promising anti-tumor effects. Unfortunately, high expectations for anti-IGF-IR therapy encountered challenge and disappointment in numerous clinical trials. This review summarizes the regulation of EMT by IGF-I/IGF-IR signaling pathway and drug resistance mechanisms of targeting IGF-IR therapy. Most importantly, we address several factors in the regulation of IGF-I/IGF-IR-associated EMT progression that may be potential predictive biomarkers in targeted therapy.

NADPH oxidase-mediated redox signaling promotes oxidative stress resistance and longevity through memo-1 in C. elegans

Transient increases in mitochondrially-derived reactive oxygen species (ROS) activate an adaptive stress response to promote longevity. Nicotinamide adenine dinucleotide phosphate (NADPH) oxidases produce ROS locally in response to various stimuli, and thereby regulate many cellular processes, but their role in aging remains unexplored. Here, we identified the C. elegans orthologue of mammalian mediator of ErbB2-driven cell motility, MEMO-1, as a protein that inhibits BLI-3/NADPH oxidase. MEMO-1 is complexed with RHO-1/RhoA/GTPase and loss of memo-1 results in an enhanced interaction of RHO-1 with BLI-3/NADPH oxidase, thereby stimulating ROS production that signal via p38 MAP kinase to the transcription factor SKN-1/NRF1,2,3 to promote stress resistance and longevity. Either loss of memo-1 or increasing BLI-3/NADPH oxidase activity by overexpression is sufficient to increase lifespan. Together, these findings demonstrate that NADPH oxidase-induced redox signaling initiates a transcriptional response that protects the cell and organism, and can promote both stress resistance and longevity.

DOI:http://dx.doi.org/10.7554/eLife.19493.001

Resveratrol inhibits IL-6-induced ovarian cancer cell migration through epigenetic up-regulation of autophagy

Interleukin-6 (IL-6), a pro-inflammatory cytokine released by cancer-associated fibroblasts, has been linked to the invasive and metastatic behavior of ovarian cancer cells. Resveratrol is a naturally occurring polyphenol with the potential to inhibit cancer cell migration. Here we show that Resveratrol and IL-6 affect in an opposite manner the expression of RNA messengers and of microRNAs involved in cell locomotion and extracellular matrix remodeling associated with the invasive properties of ovarian cancer cells. Among the several potential candidates responsible for the anti-invasive effect promoted by Resveratrol, here we focused our attention on ARH-I (DIRAS3), that encodes a Ras homolog GTPase of 26-kDa. This protein is known to inhibit cell motility, and it has been shown to regulate autophagy by interacting with BECLIN 1. IL-6 down-regulated the expression of ARH-I and inhibited the formation of LC3-positive autophagic vacuoles, while promoting cell migration. On opposite, Resveratrol could counteract the IL-6 induction of cell migration in ovarian cancer cells through induction of autophagy in the cells at the migration front, which was paralleled by up-regulation of ARH-I and down-regulation of STAT3 expression. Spautin 1-mediated disruption of BECLIN 1-dependent autophagy abrogated the effects of Resveratrol, while promoting cell migration. The present data indicate that Resveratrol elicits its anti-tumor effect through epigenetic mechanisms and support its inclusion in the chemotherapy regimen for highly aggressive ovarian cancers. © 2016 Wiley Periodicals, Inc.

miR-374a-CCND1-pPI3K/AKT-c-JUN feedback loop modulated by PDCD4 suppresses cell growth, metastasis, and sensitizes nasopharyngeal carcinoma to cisplatin

miR-374a has been reported to function as an oncogene during tumor pathogenesis. In this study, miR-374a is observed to reduce nasopharyngeal carcinoma (NPC) cell proliferation, migration, invasion, metastasis and cisplatin (DDP) resistance in vitro and in vivo. Mechanistic analyses indicate that miR-374a directly targets CCND1 to inactivate pPI3K/pAKT/c-JUN forming a negative feedback loop, as well as suppressing downstream signals related to cell cycle progression and epithelial-mesenchymal transition (EMT). Interestingly, we also observed that miR-374a direct targeting of CCND1 is modulated by tumor suppressor PDCD4 via suppressing pPI3K/pAKT/c-JUN signaling. In clinical specimens, miR-374a was positively and negatively correlated with expression of PDCD4 and CCND1, respectively. Our studies are the first to demonstrate that the miR-374a-CCND1-pPI3K/AKT-c-JUN feedback loop induced by PDCD4 supresses NPC cell growth, metastasis and chemotherapy resistance.

Proteomic analysis of differentially expressed skin proteins in iRhom2(Uncv) mice

A mouse homozygous for the spontaneous mutation uncovered (Uncv) has a hairless phenotype. A 309-bp non-frameshift deletion mutation in the N-terminal cytoplasmic domain of iRhom2 was identified in Uncv mice (iRhom2^Uncv) using target region sequencing. The detailed molecular basis for how the iRhom2 mutation causes the hairless phenotype observed in the homozygous iRhom2^Uncv mouse remains unknown. To identify differentially expressed proteins in the skin of wild-type and homozygous iRhom2^Uncv littermates at postnatal day 5, proteomic approaches, including two-dimensional gel electrophoresis and mass spectrometry were used. Twelve proteins were differentially expressed in the skin in a comparison between wild-type and homozygous iRhom2^Uncv mice. A selection of the proteomic results were tested and verified using qRT-PCR, western blot and immunohistochemistry. These data indicate that differentially expressed proteins, especially KRT73, MEMO1 and Coro-1, might participate in the mechanism by which iRhom2 regulates the development of murine skin. [BMB Reports 2015; 48(1): 19-24]

Aberrant Expression of proPTPRN2 in Cancer Cells Confers Resistance to Apoptosis

The protein tyrosine phosphatase receptor PTPRN2 is expressed predominantly in endocrine and neuronal cells, where it functions in exocytosis. We found that its immature isoform proPTPRN2 is overexpressed in various cancers, including breast cancer. High proPTPRN2 expression was associated strongly with lymph node-positive breast cancer and poor clinical outcome. Loss of proPTPRN2 in breast cancer cells promoted apoptosis and blocked tumor formation in mice, whereas enforced expression of proPTPRN2 in nontransformed human mammary epithelial cells exerted a converse effect. Mechanistic investigations suggested that ProPTPRN2 elicited these effects through direct interaction with TRAF2, a hub scaffold protein for multiple kinase cascades, including ones that activate NF-κB. Overall, our results suggest PTPRN2 as a novel candidate biomarker and therapeutic target in breast cancer.

Epithelial Plasticity in Cancer: Unmasking a MicroRNA Network for TGF-β-, Notch-, and Wnt-Mediated EMT

Epithelial-to-mesenchymal transition (EMT) is a reversible process by which cancer cells can switch from a sessile epithelial phenotype to an invasive mesenchymal state. EMT enables tumor cells to become invasive, intravasate, survive in the circulation, extravasate, and colonize distant sites. Paracrine heterotypic stroma-derived signals as well as paracrine homotypic or autocrine signals can mediate oncogenic EMT and contribute to the acquisition of stem/progenitor cell properties, expansion of cancer stem cells, development of therapy resistance, and often lethal metastatic disease. EMT is regulated by a variety of stimuli that trigger specific intracellular signalling pathways. Altered microRNA (miR) expression and perturbed signalling pathways have been associated with epithelial plasticity, including oncogenic EMT. In this review we analyse and describe the interaction between experimentally validated miRs and their target genes in TGF-β, Notch, and Wnt signalling pathways. Interestingly, in this process, we identified a “signature” of 30 experimentally validated miRs and a cluster of validated target genes that seem to mediate the cross talk between TGF-β, Notch, and Wnt signalling networks during EMT and reinforce their connection to the regulation of epithelial plasticity in health and disease.

Profiling maternal plasma microRNA expression in early pregnancy to predict gestational diabetes mellitus

OBJECTIVE

To profile the differential expression of plasma miRNAs in gestational diabetes mellitus (GDM).

METHODS

In a pilot study conducted at a tertiary hospital in China between 2010 and 2014, peripheral blood samples were collected from women at 16-19weeks of pregnancy. Pooled samples from 10 women who were subsequently diagnosed with GDM and from 10 healthy controls were used to construct two small RNA libraries. High-throughput sequencing was performed, and differentially expressed miRNAs were validated by quantitative real-time polymerase chain reaction (qRT-PCR), followed by target prediction, Gene Ontology analysis, and pathway identification.

RESULTS

Sequencing revealed 32 miRNAs that were differentially expressed in GDM, including 12 miRNAs that were upregulated and 20 that were downregulated. Differential expression of five upregulated miRNAs (hsa-miR-16-5p, hsa-miR-17-5p, hsa-miR-19a-3p, hsa-miR-19b-3p, hsa-miR-20a-5p) was confirmed by qRT-PCR. Target prediction showed that the major targets of these miRNAs were associated with insulin resistance and abnormal pregnancies.

CONCLUSION

The five miRNAs that were differentially expressed in GDM could serve as noninvasive biomarkers. The results also provide insights into the molecular mechanisms that underlie GDM, thereby contributing to the diagnosis and treatment of this disease.

Epithelial-to-mesenchymal transition in breast cancer: a role for insulin-like growth factor I and insulin-like growth factor-binding protein 3?

Evidence indicates that for most human cancers the problem is not that gene mutations occur but is more dependent upon how the body deals with damaged cells. It has been estimated that only about 1% of human cancers can be accounted for by unmistakable hereditary cancer syndromes, only up to 5% can be accounted for due to high-penetrance, single-gene mutations, and in total only 5%-15% of all cancers may have a major genetic component. The predominant contribution to the causation of most sporadic cancers is considered to be environmental factors contributing between 58% and 82% toward different cancers. A nutritionally poor lifestyle is associated with increased risk of many cancers, including those of the breast. As nutrition, energy balance, macronutrient composition of the diet, and physical activity levels are major determinants of insulin-like growth factor (IGF-I) bioactivity, it has been proposed that, at least in part, these increases in cancer risk and progression may be mediated by alterations in the IGF axis, related to nutritional lifestyle. Localized breast cancer is a manageable disease, and death from breast cancer predominantly occurs due to the development of metastatic disease as treatment becomes more complicated with poorer outcomes. In recent years, epithelial-to-mesenchymal transition has emerged as an important contributor to breast cancer progression and malignant transformation resulting in tumor cells with increased potential for migration and invasion. Furthermore, accumulating evidence suggests a strong link between components of the IGF pathway, epithelial-to-mesenchymal transition, and breast cancer mortality. Here, we highlight some recent studies highlighting the relationship between IGFs, IGF-binding protein 3, and epithelial-to-mesenchymal transition.