scholarly journals Macrophages, Inflammation, and Tumor Suppressors: ARF, a New Player in the Game

2012 ◽  
Vol 2012 ◽  
pp. 1-11 ◽  
Author(s):  
Paqui G. Través ◽  
Alfonso Luque ◽  
Sonsoles Hortelano
Keyword(s):  
Tumor Suppressor ◽  
Immune Responses ◽  
Cancer Progression ◽  
Tumor Suppressors ◽  
Tumor Suppressor Genes ◽  
Molecular Mechanisms ◽  
Clinical Evidence ◽  
Macrophage Polarization ◽  
Innate Immune

The interaction between tumor progression and innate immune system has been well established in the last years. Indeed, several lines of clinical evidence indicate that immune cells such as tumor-associated macrophages (TAMs) interact with tumor cells, favoring growth, angiogenesis, and metastasis of a variety of cancers. In most tumors, TAMs show properties of an alternative polarization phenotype (M2) characterized by the expression of a series of chemokines, cytokines, and proteases that promote immunosuppression, tumor proliferation, and spreading of the cancer cells. Tumor suppressor genes have been traditionally linked to the regulation of cancer progression; however, a growing body of evidence indicates that these genes also play essential roles in the regulation of innate immunity pathways through molecular mechanisms that are still poorly understood. In this paper, we provide an overview of the immunobiology of TAMs as well as what is known about tumor suppressors in the context of immune responses. Recent advances regarding the role of the tumor suppressor ARF as a regulator of inflammation and macrophage polarization are also reviewed.

scholarly journals The Role of microRNAs in the Regulation of Apoptosis in Lung Cancer and Its Application in Cancer Treatment

2014 ◽  
Vol 2014 ◽  
pp. 1-19 ◽  
Author(s):  
Norahayu Othman ◽  
Noor Hasima Nagoor
Keyword(s):  
Lung Cancer ◽  
Cancer Progression ◽  
High Frequency ◽  
Tumor Suppressor Genes ◽  
Molecular Mechanisms ◽  
Lung Carcinogenesis ◽  
The Past ◽  
Late Stage Diagnosis ◽  
Anticancer Treatment

Lung cancer remains to be one of the most common and serious types of cancer worldwide. While treatment is available, the survival rate of this cancer is still critically low due to late stage diagnosis and high frequency of drug resistance, thus highlighting the pressing need for a greater understanding of the molecular mechanisms involved in lung carcinogenesis. Studies in the past years have evidenced that microRNAs (miRNAs) are critical players in the regulation of various biological functions, including apoptosis, which is a process frequently evaded in cancer progression. Recently, miRNAs were demonstrated to possess proapoptotic or antiapoptotic abilities through the targeting of oncogenes or tumor suppressor genes. This review examines the involvement of miRNAs in the apoptotic process of lung cancer and will also touch on the promising evidence supporting the role of miRNAs in regulating sensitivity to anticancer treatment.

scholarly journals Ironing Out the Details: How Iron Orchestrates Macrophage Polarization

2021 ◽  
Vol 12 ◽  
Author(s):  
Yaoyao Xia ◽  
Yikun Li ◽  
Xiaoyan Wu ◽  
Qingzhuo Zhang ◽  
Siyuan Chen ◽  
...  
Keyword(s):  
Adjuvant Therapy ◽  
Immune Responses ◽  
Epigenetic Regulation ◽  
Crucial Role ◽  
Liver Diseases ◽  
Iron Supplementation ◽  
Macrophage Polarization ◽  
Innate Immune ◽  
Innate Immune Responses

Iron fine-tunes innate immune responses, including macrophage inflammation. In this review, we summarize the current understanding about the iron in dictating macrophage polarization. Mechanistically, iron orchestrates macrophage polarization through several aspects, including cellular signaling, cellular metabolism, and epigenetic regulation. Therefore, iron modulates the development and progression of multiple macrophage-associated diseases, such as cancer, atherosclerosis, and liver diseases. Collectively, this review highlights the crucial role of iron for macrophage polarization, and indicates the potential application of iron supplementation as an adjuvant therapy in different inflammatory disorders relative to the balance of macrophage polarization.

Molecular Pathogenesis of MDS

Hematology ◽  
2005 ◽  
Vol 2005 (1) ◽  
pp. 156-160 ◽  
Author(s):  
A. Thomas Look
Keyword(s):  
Tumor Suppressor ◽  
Progenitor Cells ◽  
Tumor Suppressors ◽  
Tumor Suppressor Genes ◽  
Molecular Mechanisms ◽  
Point Mutations ◽  
Suppressor Genes ◽  
Hematopoietic Stem ◽  
Chromosomal Deletions ◽  
Genes Encoding

Abstract Clonal disorders of hematopoiesis, such as myelodysplastic syndromes (MDS) and myeloproliferative diseases (MPD), affect both hematopoietic stem cells and progenitor cells within the erythroid, platelet and granulocytic lineages and can have devastating consequences in children and adults. The genetic features of these diseases often include clonal, nonrandom chromosomal deletions (e.g., 7q–, 5q–, 20q–, 6q–, 11q– and 13q–) that appear to inactivate tumor suppressor genes required for the normal development of myeloid cells (reviewed in Bench1 and Fenaux2). These putative tumor suppressors have proved to be much more difficult to identify than oncogenes activated by chromosomal translocations, the other major class of chromosomal lesions in MDS and MPD.3 Although MDS and MPD are almost certainly caused by mutations in stem/progenitor cells,4 the role of inactivated tumor suppressor genes in this process remains poorly understood. In a small portion of myeloid diseases, mutations have been identified in genes encoding factors known to be required for normal hematopoiesis, such as PU.1, RUNX1, CTNNA1 (α-catenin) and c/EBPα, and implicating these genes as tumor suppressors.5–7 Nonetheless, the identities of most deletion-associated tumor suppressors in these diseases remains elusive, despite complete sequencing of the human genome. The deleted regions detected by cytogenetic methods are generally very large, containing many hundreds of genes, thus making it hard to locate the critical affected gene or genes. It is also unclear whether dysfunctional myelopoiesis results from haploinsufficiency, associated with the deletion of one allele, or from homozygous inactivation due to additional point mutations or microdeletions of the retained wild-type allele. In general MDS have proved surprisingly resistant to conventional treatments. Targeted therapeutic advances in MDS will likely depend on a full comprehension of underlying molecular mechanisms, in particular the tumor suppressor genes lost through clonal, nonrandom chromosomal deletions, such as the 7q– and (del)5q.

scholarly journals A Different Facet of p53 Function: Regulation of Immunity and Inflammation During Tumor Development

2021 ◽  
Vol 9 ◽  
Author(s):  
Di Shi ◽  
Peng Jiang
Keyword(s):  
Tumor Suppressor ◽  
Immune Responses ◽  
Tumor Development ◽  
Suppressive Effect ◽  
Innate Immune ◽  
Tumor Suppressor P53 ◽  
Cycle Arrest ◽  
Evolutionarily Conserved ◽  
Cellular Stresses

As a key transcription factor, the evolutionarily conserved tumor suppressor p53 (encoded by TP53) plays a central role in response to various cellular stresses. A variety of biological processes are regulated by p53 such as cell cycle arrest, apoptosis, senescence and metabolism. Besides these well-known roles of p53, accumulating evidence show that p53 also regulates innate immune and adaptive immune responses. p53 influences the innate immune system by secreted factors that modulate macrophage function to suppress tumourigenesis. Dysfunction of p53 in cancer affects the activity and recruitment of T and myeloid cells, resulting in immune evasion. p53 can also activate key regulators in immune signaling pathways which support or impede tumor development. Hence, it seems that the tumor suppressor p53 exerts its tumor suppressive effect to a considerable extent by modulating the immune response. In this review, we concisely discuss the emerging connections between p53 and immune responses, and their impact on tumor progression. Understanding the role of p53 in regulation of immunity will help to developing more effective anti-tumor immunotherapies for patients with TP53 mutation or depletion.

scholarly journals HERC Ubiquitin Ligases in Cancer

Cancers ◽  
2020 ◽  
Vol 12 (6) ◽  
pp. 1653
Author(s):  
Joan Sala-Gaston ◽  
Arturo Martinez-Martinez ◽  
Leonardo Pedrazza ◽  
L. Francisco Lorenzo-Martín ◽  
Rubén Caloto ◽  
...  
Keyword(s):  
Immune Responses ◽  
Tumor Suppressors ◽  
Molecular Mechanisms ◽  
Ubiquitin Ligases ◽  
Tumor Type ◽  
E3 Ligases ◽  
Cellular Processes ◽  
Damage Response ◽  
Herc Proteins

HERC proteins are ubiquitin E3 ligases of the HECT family. The HERC subfamily is composed of six members classified by size into large (HERC1 and HERC2) and small (HERC3–HERC6). HERC family ubiquitin ligases regulate important cellular processes, such as neurodevelopment, DNA damage response, cell proliferation, cell migration, and immune responses. Accumulating evidence also shows that this family plays critical roles in cancer. In this review, we provide an integrated view of the role of these ligases in cancer, highlighting their bivalent functions as either oncogenes or tumor suppressors, depending on the tumor type. We include a discussion of both the molecular mechanisms involved and the potential therapeutic strategies.

scholarly journals The role of mitophagy in innate immune responses triggered by mitochondrial stress

2020 ◽  
Vol 18 (1) ◽  
Author(s):  
Yinjuan Song ◽  
Yang Zhou ◽  
Xiangmei Zhou
Keyword(s):  
Cell Death ◽  
Immune Responses ◽  
Immune Evasion ◽  
Molecular Mechanisms ◽  
Innate Immune ◽  
Acid Oxidation ◽  
Innate Immune Responses ◽  
Mitochondrial Stress ◽  
Cellular Organelles

Abstract Mitochondria are important cellular organelles involved in many different functions, from energy generation and fatty acid oxidation to cell death regulation and immune responses. Accumulating evidence indicates that mitochondrial stress acts as a key trigger of innate immune responses. Critically, the dysfunctional mitochondria can be selectively eliminated by mitophagy. The elimination of dysfunctional mitochondria may function as an effective way employed by mitophagy to keep the immune system in check. In addition, mitophagy can be utilized by pathogens for immune evasion. In this review, we summarize how mitochondrial stress triggers innate immune responses and the roles of mitophagy in innate immunity and in infection, as well as the molecular mechanisms of mitophagy. Graphical abstract

scholarly journals Mechanically activated ion channel Piezo1 modulates macrophage polarization and stiffness sensing

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Hamza Atcha ◽  
Amit Jairaman ◽  
Jesse R. Holt ◽  
Vijaykumar S. Meli ◽  
Raji R. Nagalla ◽  
...  
Keyword(s):  
Wound Healing ◽  
Immune Responses ◽  
Positive Feedback ◽  
Macrophage Activation ◽  
Molecular Mechanisms ◽  
Macrophage Polarization ◽  
Subcutaneous Implantation

AbstractMacrophages perform diverse functions within tissues during immune responses to pathogens and injury, but molecular mechanisms by which physical properties of the tissue regulate macrophage behavior are less well understood. Here, we examine the role of the mechanically activated cation channel Piezo1 in macrophage polarization and sensing of microenvironmental stiffness. We show that macrophages lacking Piezo1 exhibit reduced inflammation and enhanced wound healing responses. Additionally, macrophages expressing the transgenic Ca2+ reporter, Salsa6f, reveal that Ca2+ influx is dependent on Piezo1, modulated by soluble signals, and enhanced on stiff substrates. Furthermore, stiffness-dependent changes in macrophage function, both in vitro and in response to subcutaneous implantation of biomaterials in vivo, require Piezo1. Finally, we show that positive feedback between Piezo1 and actin drives macrophage activation. Together, our studies reveal that Piezo1 is a mechanosensor of stiffness in macrophages, and that its activity modulates polarization responses.

scholarly journals Adaptation to Adversity: the Intermingling of Stress Tolerance and Pathogenesis in Enterococci

2019 ◽  
Vol 83 (3) ◽  
Author(s):  
Anthony O. Gaca ◽  
José A. Lemos
Keyword(s):  
Gastrointestinal Tract ◽  
Immune Responses ◽  
Stress Tolerance ◽  
Molecular Mechanisms ◽  
Multidrug Resistant ◽  
Innate Immune ◽  
Innate Immune Responses ◽  
Hospital Acquired Infections ◽  
Hospital Acquired

SUMMARY Enterococcus is a diverse and rugged genus colonizing the gastrointestinal tract of humans and numerous hosts across the animal kingdom. Enterococci are also a leading cause of multidrug-resistant hospital-acquired infections. In each of these settings, enterococci must contend with changing biophysical landscapes and innate immune responses in order to successfully colonize and transit between hosts. Therefore, it appears that the intrinsic durability that evolved to make enterococci optimally competitive in the host gastrointestinal tract also ideally positioned them to persist in hospitals, despite disinfection protocols, and acquire new antibiotic resistances from other microbes. Here, we discuss the molecular mechanisms and regulation employed by enterococci to tolerate diverse stressors and highlight the role of stress tolerance in the biology of this medically relevant genus.

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