scholarly journals Evidence of a Prion-Like Transmission of p53 Amyloid in Saccharomyces cerevisiae

2017 ◽  
Vol 37 (18) ◽  
Author(s):  
Shinjinee Sengupta ◽  
Samir K. Maji ◽  
Santanu K. Ghosh

ABSTRACT Loss of p53 function is largely responsible for the occurrence of cancer in humans. Aggregation of mutant p53 has been found in multiple cancer cell types, suggesting a role of aggregation in loss of p53 function and cancer development. The p53 protein has recently been hypothesized to possess a prion-like conformation, although experimental evidence is lacking. Here, we report that human p53 can be inactivated upon exposure to preformed fibrils containing an aggregation-prone sequence-specific peptide, PILTIITL, derived from p53, and the inactive state was found to be stable for many generations. Importantly, we provide evidence of a prion-like transmission of these p53 aggregates. This study has significant implications for understanding cancer progression due to p53 malfunctioning without any loss-of-function mutation or occurrence of transcriptional inactivation. Our data might unlock new possibilities for understanding the disease and will lead to rational design of p53 aggregation inhibitors for the development of drugs against cancer.

Cancers ◽  
2021 ◽  
Vol 13 (14) ◽  
pp. 3465
Author(s):  
Aya Saleh ◽  
Ruth Perets

Mutations in tumor suppressor gene TP53, encoding for the p53 protein, are the most ubiquitous genetic variation in human ovarian HGSC, the most prevalent and lethal histologic subtype of epithelial ovarian cancer (EOC). The majority of TP53 mutations are missense mutations, leading to loss of tumor suppressive function of p53 and gain of new oncogenic functions. This review presents the clinical relevance of TP53 mutations in HGSC, elaborating on several recently identified upstream regulators of mutant p53 that control its expression and downstream target genes that mediate its roles in the disease. TP53 mutations are the earliest genetic alterations during HGSC pathogenesis, and we summarize current information related to p53 function in the pathogenesis of HGSC. The role of p53 is cell autonomous, and in the interaction between cancer cells and its microenvironment. We discuss the reduction in p53 expression levels in tumor associated fibroblasts that promotes cancer progression, and the role of mutated p53 in the interaction between the tumor and its microenvironment. Lastly, we discuss the potential of TP53 mutations to serve as diagnostic biomarkers and detail some more advanced efforts to use mutated p53 as a therapeutic target in HGSC.


2017 ◽  
Vol 2 (1) ◽  
Author(s):  
Dalia Martinez-Marin ◽  
Courtney Jarvis ◽  
Thomas Nelius ◽  
Stéphanie Filleur

Abstract Macrophages have been recognized as the main inflammatory component of the tumor microenvironment. Although often considered as beneficial for tumor growth and disease progression, tumor-associated macrophages have also been shown to be detrimental to the tumor depending on the tumor microenvironment. Therefore, understanding the molecular interactions between macrophages and tumor cells in relation to macrophages functional activities such as phagocytosis is critical for a better comprehension of their tumor-modulating action. Still, the characterization of these molecular mechanisms in vivo remains complicated due to the extraordinary complexity of the tumor microenvironment and the broad range of tumor-associated macrophage functions. Thus, there is an increasing demand for in vitro methodologies to study the role of cell–cell interactions in the tumor microenvironment. In the present study, we have developed live co-cultures of macrophages and human prostate tumor cells to assess the phagocytic activity of macrophages using a combination of Confocal and Nomarski Microscopy. Using this model, we have emphasized that this is a sensitive, measurable, and highly reproducible functional assay. We have also highlighted that this assay can be applied to multiple cancer cell types and used as a selection tool for a variety of different types of phagocytosis agonists. Finally, combining with other studies such as gain/loss of function or signaling studies remains possible. A better understanding of the interactions between tumor cells and macrophages may lead to the identification of new therapeutic targets against cancer.


2019 ◽  
Vol 20 (24) ◽  
pp. 6256 ◽  
Author(s):  
Raju Dash ◽  
Md. Chayan Ali ◽  
Nayan Dash ◽  
Md. Abul Kalam Azad ◽  
S. M. Zahid Hosen ◽  
...  

Sulfotransferase 1A1 (SULT1A1) is responsible for catalyzing various types of endogenous and exogenous compounds. Accumulating data indicates that the polymorphism rs9282861 (R213H) is responsible for inefficient enzymatic activity and associated with cancer progression. To characterize the detailed functional consequences of this mutation behind the loss-of-function of SULT1A1, the present study deployed molecular dynamics simulation to get insights into changes in the conformation and binding energy. The dynamics scenario of SULT1A1 in both wild and mutated types as well as with and without ligand showed that R213H induced local conformational changes, especially in the substrate-binding loop rather than impairing overall stability of the protein structure. The higher conformational changes were observed in the loop3 (residues, 235–263), turning loop conformation to A-helix and B-bridge, which ultimately disrupted the plasticity of the active site. This alteration reduced the binding site volume and hydrophobicity to decrease the binding affinity of the enzyme to substrates, which was highlighted by the MM-PBSA binding energy analysis. These findings highlight the key insights of structural consequences caused by R213H mutation, which would enrich the understanding regarding the role of SULT1A1 mutation in cancer development and also xenobiotics management to individuals in the different treatment stages.


Cancers ◽  
2020 ◽  
Vol 12 (2) ◽  
pp. 396
Author(s):  
Estíbaliz Tamayo-Orbegozo ◽  
Laura Amo ◽  
Javier Díez-García ◽  
Elena Amutio ◽  
Marta Riñón ◽  
...  

Mature B-cell non-Hodgkin lymphoma (B-NHL) constitutes a group of heterogeneous malignant lymphoproliferative diseases ranging from indolent to highly aggressive forms. Although the survival after chemo-immunotherapy treatment of mature B-NHL has increased over the last years, many patients relapse or remain refractory due to drug resistance, presenting an unfavorable prognosis. Hence, there is an urgent need to identify new prognostic markers and therapeutic targets. Podocalyxin (PODXL), a sialomucin overexpressed in a variety of tumor cell types and associated with their aggressiveness, has been implicated in multiple aspects of cancer progression, although its participation in hematological malignancies remains unexplored. New evidence points to a role for PODXL in mature B-NHL cell proliferation, survival, migration, drug resistance, and metabolic reprogramming, as well as enhanced levels of PODXL in mature B-NHL. Here, we review the current knowledge on the contribution of PODXL to tumorigenesis, highlighting and discussing its role in mature B-NHL progression.


2021 ◽  
Vol 20 (1) ◽  
Author(s):  
Chao Li ◽  
Adilson Fonseca Teixeira ◽  
Hong-Jian Zhu ◽  
Peter ten Dijke

AbstractTo identify novel cancer therapies, the tumor microenvironment (TME) has received a lot of attention in recent years in particular with the advent of clinical successes achieved by targeting immune checkpoint inhibitors (ICIs). The TME consists of multiple cell types that are embedded in the extracellular matrix (ECM), including immune cells, endothelial cells and cancer associated fibroblasts (CAFs), which communicate with cancer cells and each other during tumor progression. CAFs are a dominant and heterogeneous cell type within the TME with a pivotal role in controlling cancer cell invasion and metastasis, immune evasion, angiogenesis and chemotherapy resistance. CAFs mediate their effects in part by remodeling the ECM and by secreting soluble factors and extracellular vesicles. Exosomes are a subtype of extracellular vesicles (EVs), which contain various biomolecules such as nucleic acids, lipids, and proteins. The biomolecules in exosomes can be transmitted from one to another cell, and thereby affect the behavior of the receiving cell. As exosomes are also present in circulation, their contents can also be explored as biomarkers for the diagnosis and prognosis of cancer patients. In this review, we concentrate on the role of CAFs-derived exosomes in the communication between CAFs and cancer cells and other cells of the TME. First, we introduce the multiple roles of CAFs in tumorigenesis. Thereafter, we discuss the ways CAFs communicate with cancer cells and interplay with other cells of the TME, and focus in particular on the role of exosomes. Then, we elaborate on the mechanisms by which CAFs-derived exosomes contribute to cancer progression, as well as and the clinical impact of exosomes. We conclude by discussing aspects of exosomes that deserve further investigation, including emerging insights into making treatment with immune checkpoint inhibitor blockade more efficient.


Author(s):  
Katerina Strouhalova ◽  
Magdalena Přechová ◽  
Aneta Gandalovičová ◽  
Jan Brábek ◽  
Martin Gregor ◽  
...  

Intermediate filaments constitute the third component of the cellular skeleton. Unlike actin and microtubule cytoskeletons, the intermediate filaments are composed of wide variety of structurally related proteins showing distinct expression patterns in tissues and cell types. Changes in expression patterns of intermediate filaments are often associated with cancer progression, in particular with phenotypes leading to increased cellular migration and invasion. In this review we will describe the role of vimentin intermediate filaments in cancer cell migration, cell adhesion structures, and metastasis formation. The potential for targeting vimentin in cancer treatment and the development of drugs targeting vimentin will be reviewed.


2014 ◽  
Vol 2014 ◽  
pp. 1-8 ◽  
Author(s):  
Sarah L. Newstead ◽  
Amanda J. Gates ◽  
M. Gillian Hartley ◽  
Caroline A. Rowland ◽  
E. Diane Williamson ◽  
...  

Reactive nitrogen is critical for the clearance ofFrancisella tularensisinfections. Here we assess the role of nitric oxide in control of intracellular infections in two murine macrophage cell lines of different provenance: the alveolar macrophage cell line, MH-S, and the widely used peritoneal macrophage cell line, J774A.1. Cells were infected with the highly virulent Schu S4 strain or with the avirulent live vaccine strain (LVS) with and without stimuli. Compared to MH-S cells, J774A.1 cells were unresponsive to stimulation and were able to control the intracellular replication of LVS bacteria, but not of Schu S4. In MH-S cells, Schu S4 demonstrated control over cellular NO production. Despite this, MH-S cells stimulated with LPS or LPS and IFN-γwere able to control intracellular Schu S4 numbers. However, only stimulation with LPS induced significant cellular NO production. Combined stimulation with LPS and IFN-γproduced a significant reduction in intracellular bacteria that occurred whether high levels of NO were produced or not, indicating that NO secretion is not the only defensive cellular mechanism operating in virulentFrancisellainfections. Understanding howF. tularensisinteracts with host macrophages will help in the rational design of new and effective therapies.


2019 ◽  
Vol 3 (1) ◽  
pp. 21-34 ◽  
Author(s):  
Arnold J. Levine

Half of all human cancers contain TP53 mutations, and in many other cancers, the function of the p53 protein is compromised. The diversity of these mutations and phenotypes presents a challenge to the development of drugs that target p53 mutant cancer cells. This review describes the rationale for many different approaches in the development of p53 targeted therapies: ( a) viruses and gene therapies, ( b) increased levels and activity of wild-type p53 proteins in cancer cells, ( c) p53 protein gain-of-function inhibitors, ( d) p53 protein loss-of-function structural correctors, ( e) mutant p53 protein synthetic lethal drugs interfering with the p53 pathway, and ( f) cellular immune responses to mutant p53 protein antigens. As these types of therapies are developed, tested, and evaluated, the best of them will have a significant impact upon cancer treatments and possibly prevention.


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