Ablation of Mina53 in mice reduces allergic response in the airways

Predicting role of Myc-induced nuclear antigen 53 in determining the development and severity of systemic lupus erythematosus

Introduction

Systemic lupus erythematosus (SLE) as an autoimmune disease can relate to an imbalance between regulatory T cells (Tregs) and Th17 cells. Previous reports have shown that Myc-induced nuclear antigen (Mina) 53 protein is involved in the developments of Tregs and Th17 cells. Therefore, the current study focused on determining whether Mina53 level is correlated to the severity of SLE.

Methods

The blood samples were collected from 60 patients with SLE (30 cases with mild SLE and 30 cases with severe SLE) and 30 healthy subjects. The serum concentration of Mina53 was measured using enzyme-linked immunosorbent assay (ELISA). The expression of Mina53 gene was assessed using real-time PCR method after extracting RNA from isolated peripheral blood mononuclear cells and synthesizing cDNA.

Results

Patients with SLE showed significant increases in the serum level and gene expression of Mina53 compared to healthy subjects (P<0.001). Furthermore, serum level and gene expression of Mina53 showed significant effects on SLE disease and its severity (P<0.01). There was the highest sensitivity and maximum specificity in the cut-off point of Mina53 serum level equal to 125.4 (area under the curve (AUC)=0.951) and Mina53 expression level equal to 8.5 (AUC=0.88) for SLE diagnosis. The cut-off point of Mina53 serum level equal to 139.5 (AUC=0.854) and the cut-off point of Mina53 expression level equal to 8.5 (AUC=0.788) had the highest sensitivity and maximum specificity determining severe forms of SLE.

Discussion

Our results showed that the changes in serum and expression levels of Mina53 have significant effects on SLE disease and its severity. These levels may be considered as diagnostic and predictive markers for SLE.

JMJD family proteins in cancer and inflammation

The occurrence of cancer entails a series of genetic mutations that favor uncontrollable tumor growth. It is believed that various factors collectively contribute to cancer, and there is no one single explanation for tumorigenesis. Epigenetic changes such as the dysregulation of enzymes modifying DNA or histones are actively involved in oncogenesis and inflammatory response. The methylation of lysine residues on histone proteins represents a class of post-translational modifications. The human Jumonji C domain-containing (JMJD) protein family consists of more than 30 members. The JMJD proteins have long been identified with histone lysine demethylases (KDM) and histone arginine demethylases activities and thus could function as epigenetic modulators in physiological processes and diseases. Importantly, growing evidence has demonstrated the aberrant expression of JMJD proteins in cancer and inflammatory diseases, which might serve as an underlying mechanism for the initiation and progression of such diseases. Here, we discuss the role of key JMJD proteins in cancer and inflammation, including the intensively studied histone lysine demethylases, as well as the understudied group of JMJD members. In particular, we focused on epigenetic changes induced by each JMJD member and summarized recent research progress evaluating their therapeutic potential for the treatment of cancer and inflammatory diseases.

Depletion of Mdig Changes Proteomic Profiling in Triple Negative Breast Cancer Cells

Triple-negative breast cancers are highly aggressive with an overall poor prognosis and limited therapeutic options. We had previously investigated the role of mdig, an oncogenic gene induced by some environmental risk factors, on the pathogenesis of breast cancer. However, a comprehensive analysis of the proteomic profile affected by mdig in triple-negative breast cancer has not been determined yet. Using label-free bottom-up quantitative proteomics, we compared wildtype control and mdig knockout MDA-MB-231 cells and identified the proteins and pathways that are significantly altered with mdig deletion. A total of 904 differentially expressed (p < 0.005) proteins were identified in the KO cells. Approximately 30 pathways and networks linked to the pathogenicity of breast cancer were either up- or downregulated, such as EIF2 signaling, the unfolded protein response, and isoleucine degradation I. Ingenuity Pathway Analysis established that the differentially expressed proteins have relevant biological actions in cell growth, motility, and malignancy. These data provide the first insight into protein expression patterns in breast cancer associated with a complete disruption of the mdig gene and yielded substantial information on the key proteins, biological processes, and pathways modulated by mdig that contribute to breast cancer tumorigenicity and invasiveness.

MDIG, a 2‑oxoglutarate‑dependent oxygenase, acts as an oncogene and predicts the prognosis of multiple types of cancer

Recent studies have indicated that mineral dust‑induced gene (MDIG) is an oncogene induced by environmental factors, which has a key role in the development and progression of various tumor types, through epigenetic modifications; however, there are no previous pan‑cancer analyses of MDIG. In the present study, a comprehensive pan‑cancer analysis of MDIG was performed using public databases. The results demonstrated that MDIG was upregulated in tumor tissue samples compared with normal tissue, that it was present in all cancer cell lines and it was closely associated with the prognosis of patients with different tumor types. Furthermore, MDIG expression was closely associated with the immunological characteristics of the tumor microenvironment (TME), such as the frequency of tumor‑infiltrating immune cells, TME‑relevant signatures, immunostimulatory genes, immune checkpoint genes, chemokine receptor genes, tumor mutational burden and microsatellite instability. In parallel, high expression of MDIG was associated with improved overall survival of patients and this was verified in a cohort of patients who had received anti‑programmed cell death 1 ligand 1 treatment. Furthermore, high expression of MDIG led to multiple drug resistance in The Cancer Genome Atlas‑lung adenocarcinoma cohort. In addition, gene set variant analysis and gene set enrichment analysis indicated that MDIG was involved in cell cycle regulation. In vitro experiments suggested that MDIG promoted cell proliferation through the mTOR complex 2/Akt and pyruvate dehydrogenase kinase 1/Akt signaling pathways. In summary, the present study suggests that MDIG may be a prognostic biomarker and therapeutic target for various cancer types.

First-in-Class Inhibitors of the Ribosomal Oxygenase MINA53

MINA53 is a JmjC domain 2-oxoglutarate-dependent oxygenase that catalyzes ribosomal hydroxylation and is a target of the oncogenic transcription factor c-MYC. Despite its anticancer target potential, no small-molecule MINA53 inhibitors are reported. Using ribosomal substrate fragments, we developed mass spectrometry assays for MINA53 and the related oxygenase NO66. These assays enabled the identification of 2-(aryl)alkylthio-3,4-dihydro-4-oxoypyrimidine-5-carboxylic acids as potent MINA53 inhibitors, with selectivity over NO66 and other JmjC oxygenases. Crystallographic studies with the JmjC demethylase KDM5B revealed active site binding but without direct metal chelation; however, molecular modeling investigations indicated that the inhibitors bind to MINA53 by directly interacting with the iron cofactor. The MINA53 inhibitors manifest evidence for target engagement and selectivity for MINA53 over KDM4-6. The MINA53 inhibitors show antiproliferative activity with solid cancer lines and sensitize cancer cells to conventional chemotherapy, suggesting that further work investigating their potential in combination therapies is warranted.

Pathological and Prognostic Indications of the mdig Gene in Human Lung Cancer

BACKGROUND/AIMS

The mineral-dust-induced gene mdig is a lung-cancer-associated oncogene. The focus of this study is to evaluate the expression status of mdig in lung cancer and to assess its influence in predicting the patient's overall survival.

METHODS

Using high-density tissue microarrays and clinical samples of synchronous multiple primary lung cancer (SMPLC), we investigated the expression of mdig through immunohistochemistry and utilized the open-access lung cancer patient databases containing genomic and transcriptomic data from the UCSC Xena and TCGA web platforms to determine the prognostic values of mdig expression status among different subtypes of lung cancer.

RESULTS

mdig is upregulated in smokers and in lung squamous cell carcinoma. High mdig expression predicted poor overall survival in lung squamous cell carcinoma and female smokers. Among tumor tissues from SMPLC patients, we not only unraveled the highest positive rate of mdig expression, but also revealed a unique cytoplasmic, rather than nuclear localization of mdig protein. Furthermore, by inspecting some pathological but not cancerous lung tissues, we believe that mdig is required for the transformation of non-cancerous lung cells to the fully-fledged cancer cells.

CONCLUSION

These data suggested that mdig is involved in various stages of lung carcinogenesis, possibly through the epigenetic regulation on some critical cancer-associated genes, and increased mdig expression is an important prognostic factor for some types of lung cancer.

Human 2-oxoglutarate-dependent oxygenases: nutrient sensors, stress responders, and disease mediators

Fe(II)/2-oxoglutarate (2OG)-dependent oxygenases are a conserved enzyme class that catalyse diverse oxidative reactions across nature. In humans, these enzymes hydroxylate a broad range of biological substrates including DNA, RNA, proteins and some metabolic intermediates. Correspondingly, members of the 2OG-dependent oxygenase superfamily have been linked to fundamental biological processes, and found dysregulated in numerous human diseases. Such findings have stimulated efforts to understand both the biochemical activities and cellular functions of these enzymes, as many have been poorly studied. In this review, we focus on human 2OG-dependent oxygenases catalysing the hydroxylation of protein and polynucleotide substrates. We discuss their modulation by changes in the cellular microenvironment, particularly with respect to oxygen, iron, 2OG and the effects of oncometabolites. We also describe emerging evidence that these enzymes are responsive to cellular stresses including hypoxia and DNA damage. Moreover, we examine how dysregulation of 2OG-dependent oxygenases is associated with human disease, and the apparent paradoxical role for some of these enzymes during cancer development. Finally, we discuss some of the challenges associated with assigning biochemical activities and cellular functions to 2OG-dependent oxygenases.

The small members of the JMJD protein family: Enzymatic jewels or jinxes?

Jumonji C domain-containing (JMJD) proteins are mostly epigenetic regulators that demethylate histones. However, a hitherto neglected subfamily of JMJD proteins, evolutionarily distant and characterized by their relatively small molecular weight, exerts different functions by hydroxylating proteins and RNA. Recently, unsuspected proteolytic and tyrosine kinase activities were also ascribed to some of these small JMJD proteins, further increasing their enzymatic versatility. Here, we discuss the ten human small JMJD proteins (HIF1AN, HSPBAP1, JMJD4, JMJD5, JMJD6, JMJD7, JMJD8, RIOX1, RIOX2, TYW5) and their diverse physiological functions. In particular, we focus on the roles of these small JMJD proteins in cancer and other maladies and how they are modulated in diseased cells by an altered metabolic milieu, including hypoxia, reactive oxygen species and oncometabolites. Because small JMJD proteins are enzymes, they are amenable to inhibition by small molecules and may represent novel targets in the therapy of cancer and other diseases.

Myc-induced nuclear antigen constrains a latent intestinal epithelial cell-intrinsic anthelmintic pathway

Expulsion of parasitic gastrointestinal nematodes requires diverse effector mechanisms coordinated by a Th2-type response. The evolutionarily conserved JmjC protein; Myc Induced Nuclear Antigen (Mina) has been shown to repress IL4, a key Th2 cytokine, suggesting Mina may negatively regulate nematode expulsion. Here we report that expulsion of the parasitic nematode Trichuris muris was indeed accelerated in Mina deficient mice. Unexpectedly, this was associated not with an elevated Th2- but rather an impaired Th1-type response. Further reciprocal bone marrow chimera and conditional KO experiments demonstrated that retarded parasite expulsion and a normal Th1-type response both required Mina in intestinal epithelial cells (IECs). Transcriptional profiling experiments in IECs revealed anti-microbial α-defensin peptides to be the major target of Mina-dependent retention of worms in infected mice. In vitro exposure to recombinant α-defensin peptides caused cytotoxic damage to whipworms. These results identify a latent IEC-intrinsic anthelmintic pathway actively constrained by Mina and point to α-defensins as important effectors that together with Mina may be attractive therapeutic targets for the control of nematode infection.

Hydroxylation of protein constituents of the human translation system: structural aspects and functional assignments

During the current decade, data on the post-translational hydroxylation of specific amino acid residues of some ribosomal proteins and translation factors in both eukaryotes and eubacteria have accumulated. The reaction is catalyzed by dedicated oxygenases (so-called ribosomal oxygenases), whose action is impaired under hypoxia conditions. The modification occurs at amino acid residues directly involved in the formation of the main functional sites of ribosomes and factors. This review summarizes currently available data on the specific hydroxylation of protein constituents of eukaryotic and eubacterial translation systems with a special emphasis on the human system, as well as on the links between hypoxia impacts on the operation of ribosomal oxygenases, the functioning of the translational apparatus and human health problems.

The emerging roles of ribosomal histidyl hydroxylases in cell biology, physiology and disease

Hydroxylation is a novel protein modification catalyzed by a family of oxygenases that depend on fundamental nutrients and metabolites for activity. Protein hydroxylases have been implicated in a variety of key cellular processes that play important roles in both normal homeostasis and pathogenesis. Here, in this review, we summarize the current literature on a highly conserved sub-family of oxygenases that catalyze protein histidyl hydroxylation. We discuss the evidence supporting the biochemical assignment of these emerging enzymes as ribosomal protein hydroxylases, and provide an overview of their role in immunology, bone development, and cancer.

Loss of mdig expression enhances DNA and histone methylation and metastasis of aggressive breast cancer

We previously reported that expression of an environmentally induced gene, mineral dust-induced gene (mdig), predicts overall survival in breast cancer patients. In the present report, we further demonstrate the differential roles of mdig between earlier- and later-stage breast cancers. In noncancerous breast, mdig is a proliferation factor for cell growth and cell motility. In breast cancer, however, higher levels of mdig negatively regulate the migration and invasion of cancer cells. Assessment of global DNA methylation, chromatin accessibility and H3K9me3 heterochromatin signature suggests that silencing mdig enhances DNA and histone methylation. Through immunostaining and data mining, we found that mdig is significantly upregulated in noninvasive and/or earlier-stage breast cancers. In contrast, in triple-negative and other invasive breast cancers, diminished mdig expression was noted, indicating that the loss of mdig expression could be an important feature of aggressive breast cancers. Taken together, our data suggest that mdig is a new biomarker that likely promotes tumor growth in the early stages of breast cancer while acting as a tumor suppressor to inhibit invasion and metastasis in later-stage tumors.

Differential expression of an environmentally-induced gene appears to influence the growth of breast cancer tumors, thus providing a valuable biomarker and therapeutic target. Environmental factors can influence cancerous tumor development by interfering with epigenetic processes such as DNA and histone methylation. For example, the mineral dust induced gene (mdig) is over-expressed in coal miners who are susceptible to lung cancer. Now, Fei Chen, a pioneer in toxicology and carcinogenesis research at the Wayne State University in Detroit, USA, and his team have demonstrated that mdig also plays important roles in breast cancer. The gene is upregulated in early, non-invasive tumors, where it regulates cell growth, motility and invasion by influencing DNA and histone methylation. However, mdig expression drops in later stage or more aggressive tumor types. When the researchers abrogated mdig expression completely, they observed an enhanced DNA and histone methylation, suggesting the gene has a demethylase role and is implicated in regulating the epigenetic landscape under neoplastic conditions.

A SNP uncoupling Mina expression from the TGFβ signaling pathway

INTRODUCTION

Mina is a JmjC family 2-oxoglutarate oxygenase with pleiotropic roles in cell proliferation, cancer, T cell differentiation, pulmonary inflammation, and intestinal parasite expulsion. Although Mina expression varies according to cell-type, developmental stage and activation state, its transcriptional regulation is poorly understood. Across inbred mouse strains, Mina protein level exhibits a bimodal distribution, correlating with inheritance of a biallelic haplotype block comprising 21 promoter/intron 1-region SNPs. We previously showed that heritable differences in Mina protein level are transcriptionally regulated.

METHODS

Accordingly, we decided to test the hypothesis that at least one of the promoter/intron 1-region SNPs perturbs a Mina cis-regulatory element (CRE). Here, we have comprehensively scanned for CREs across a Mina locus-spanning 26-kilobase genomic interval.

RESULTS

We discovered 8 potential CREs and functionally validated 4 of these, the strongest of which (E2), residing in intron 1, contained a SNP whose BALB/c-but not C57Bl/6 allele-abolished both Smad3 binding and transforming growth factor beta (TGFβ) responsiveness.

CONCLUSIONS

Our results demonstrate the TGFβ signaling pathway plays a critical role in regulating Mina expression and SNP rs4191790 controls heritable variation in Mina expression level, raising important questions regarding the evolution of an allele that uncouples Mina expression from the TGFβ signaling pathway.

Oncoprotein mdig contributes to silica-induced pulmonary fibrosis by altering balance between Th17 and Treg T cells

Mineral dust-induced gene (mdig, also named Mina53) was first identified from alveolar macrophages of the coal miners with chronic lung inflammation or fibrosis, but how this gene is involved in lung diseases is poorly understood. Here we show that heterozygotic knockout of mdig (mdig+/-) ameliorates silica-induced lung fibrosis by altering the balance between Th17 cells and Treg cells. Relative to the wild type (WT) mice, infiltration of the macrophages and Th17 cells was reduced in lungs from silica-exposed mdig+/- mice. In contrast, an increased infiltration of the T regulatory (Treg) cells to the lung intestitium was observed in the mdig+/- mice treated with silica. Both the number of Th17 cells in the lung lymph nodes and the level of IL-17 in the bronchoalveolar lavage fluids were decreased in the mdig+/- mice in response to silica. Thus, these results suggest that mdig may contribute to silica-induced lung fibrosis by altering the balance between Th17 and Treg cells. Genetic deficiency of mdig impairs Th17 cell infiltration and function, but favors infiltration of the Treg cells, the immune suppressive T cells that are able to limit the inflammatory responses by repressing the Th17 cells and macrophages.

Current understanding of mdig/MINA in human cancers

Mineral dust-induced gene, mdig has recently been identified and is known to be overexpressed in a majority of human cancers and holds predictive power in the poor prognosis of the disease. Mdig is an environmentally expressed gene that is involved in cell proliferation, neoplastic transformation and immune regulation. With the advancement in deciphering the prognostic role of mdig in human cancers, our understanding on how mdig renders a normal cell to undergo malignant transformation is still very limited. This article reviews the current knowledge of the mdig gene in context to human neoplasias and its relation to the clinico-pathologic factors predicting the outcome of the disease in patients. It also emphasizes on the promising role of mdig that can serve as a potential candidate for biomarker discovery and as a therapeutic target in inflammation and cancers. Considering the recent advances in understanding the underlying mechanisms of tumor formation, more preclinical and clinical research is required to validate the potential of using mdig as a novel biological target of therapeutic and diagnostic value.

Modifying the maker: Oxygenases target ribosome biology

The complexity of the eukaryotic protein synthesis machinery is partly driven by extensive and diverse modifications to associated proteins and RNAs. These modifications can have important roles in regulating translation factor activity and ribosome biogenesis and function. Further investigation of ‘translational modifications’ is warranted considering the growing evidence implicating protein synthesis as a critical point of gene expression control that is commonly deregulated in disease. New evidence suggests that translation is a major new target for oxidative modifications, specifically hydroxylations and demethylations, which generally are catalyzed by a family of emerging oxygenase enzymes that act at the interface of nutrient availability and metabolism. This review summarizes what is currently known about the role or these enzymes in targeting rRNA synthesis, protein translation and associated cellular processes.

Mina: a Th2 response regulator meets TGFβ

The JmjC protein Mina is an important immune response regulator. Classical forward genetics first discovered its immune role in 2009 in connection with the development of T helper 2 (Th2) cells. This prompted investigation into Mina's role in the two best-studied contexts where Th2 responses are essential: atopic asthma and helminth expulsion. In work focused on a mouse model of atopic asthma, Mina deficiency was found to ameliorate airway hyper-resistance and pulmonary inflammation. And, in a case-control study genetic variation at the human MINA locus was found to be associated with the development of childhood atopic asthma. Although the underlying cellular and molecular mechanism of Mina's involvement in pulmonary inflammation remains unknown, our recent work on parasitic helminth expulsion suggests the possibility that, rather than T cells, epithelial cells responding to TGFβ may play the dominant role. Here we review the growing body of literature on the emerging Mina pathway in T cells and epithelial cells and attempt to set these into a broader context.

Carcinogenic metalloid arsenic induces expression of mdig oncogene through JNK and STAT3 activation

Environmental or occupational exposure to arsenic, a chemical element classified as metalloid, has been associated with cancer of the lung, skin, bladder, liver, etc. Mdig (mineral dust-induced gene) is a newly identified oncogene linked to occupational lung diseases and lung cancer. It is unclear whether mdig is also involved in arsenic-induced malignant transformation of the lung cells. By using human bronchial epithelial cells and human lung cancer cell lines, we showed that arsenic was able to induce expression of mdig. We further demonstrated that this mdig induction by arsenic was partially dependent on the JNK and STAT3 signaling pathways. Disruption of the JNK or STAT3 by either chemical inhibitors or siRNAs diminished arsenic-induced accumulation of mdig mRNA and protein. Furthermore, we also showed that microRNA-21 (miR-21) and Akt were down-stream effectors of the JNK and STAT3 signaling pathways in arsenic-induced mdig expression. Transfection of the cells with anti-miR-21 or pre-treatment of the cells with Akt inhibitor blunted mdig induction by arsenic. Clinically, the levels of mdig can be applied to predict the disease progression, the first progression (FP), in non-small cell lung cancer (NSCLC) patients. Taken together, our data suggest that mdig may play important roles on the pathogenesis of arsenic-induced lung cancer and that JNK and STAT3 signaling pathways are essential in mediating arsenic-induced mdig expression.

The roles of Jumonji-type oxygenases in human disease

The iron- and 2-oxoglutarate-dependent oxygenases constitute a phylogenetically conserved class of enzymes that catalyze hydroxylation reactions in humans by acting on various types of substrates, including metabolic intermediates, amino acid residues in different proteins and various types of nucleic acids. The discovery of jumonji (Jmj), the founding member of a class of Jmj-type chromatin modifying enzymes and transcriptional regulators, has culminated in the discovery of several branches of histone lysine demethylases, with essential functions in regulating the epigenetic landscape of the chromatin environment. This work has now been considerably expanded into other aspects of epigenetic biology and includes the discovery of enzymatic steps required for methyl-cytosine demethylation as well as modification of RNA and ribosomal proteins. This overview aims to summarize the current knowledge on the human Jmj-type enzymes and their involvement in human pathological processes, including development, cancer, inflammation and metabolic diseases.