scholarly journals Senescent tumor cells: an overlooked adversary in the battle against cancer

2021 ◽  
Author(s):  
Soon Sang Park ◽  
Yong Won Choi ◽  
Jang-Hee Kim ◽  
Hong Seok Kim ◽  
Tae Jun Park
Keyword(s):  
Tumor Cells ◽  
Cancer Progression ◽  
Current Knowledge ◽  
Physiological Role ◽  
Current Status ◽  
Cancer Tissue ◽  
Causative Factors ◽  
Metastatic Sites ◽  
Positive Functions

AbstractSenescent cells in cancer tissue, including senescent fibroblasts and macrophages, have been reported to increase the malignant potency of cancer cells by secreting senescence-associated secretory phenotype (SASP). Otherwise, Senescence of tumor cells has been believed to inhibit tumor growth by halting the massive proliferation and increasing the chances of immune clearance. In particular, senescent tumor cells (STCs) have been thought that they rarely exist in carcinomas because oncogene-induced senescence needs to be overcome for protumorigenic cells to become malignant. However, recent studies have revealed that a considerable number of STCs are present in cancer tissue, even in metastatic sites. In fact, STCs are widely involved in cancer progression by leading to collective invasion and building a cytokine barrier to protect nonsenescent tumor cells from immune attack. Furthermore, therapy-induced STCs can induce tumor progression and recurrence by increasing stemness. However, obscure causative factors and their heterogeneity in various cancers make it difficult to establish the physiological role of STCs. Here, we summarize and review the current knowledge of the pathophysiology and role of STCs. We also outline the current status of therapeutic strategies for directly removing STCs or modulating the SASPs to maximize the positive functions of STCs while suppressing the negative functions.

scholarly journals Remodeling the ECM: Implications for Metastasis and Tumor Dormancy

Cancers ◽  
2021 ◽  
Vol 13 (19) ◽  
pp. 4916
Author(s):  
Julie S. Di Martino ◽  
Tasmiah Akhter ◽  
Jose Javier Bravo-Cordero
Keyword(s):  
Cancer Cells ◽  
Tumor Cells ◽  
Cancer Progression ◽  
Current Knowledge ◽  
Disseminated Tumor Cells ◽  
Tumor Dormancy ◽  
Primary Tumors ◽  
Ecm Remodeling ◽  
The Individual

While most primary tumors can be effectively treated, therapeutics fail to efficiently eliminate metastases. Metastases arise from cancer cells that leave the primary tumor and seed distant sites. Recent studies have shown that cancer cells disseminate early during tumor progression and can remain dormant for years before they resume growth. In these metastatic organs, cancer cells reside in microenvironments where they interact with other cells, but also with the extracellular matrix (ECM). The ECM was long considered to be an inert, non-cellular component of tissues, providing their architecture. However, in recent years, a growing body of evidence has shown that the ECM is a key driver of cancer progression, and it can exert effects on tumor cells, regulating their metastatic fate. ECM remodeling and degradation is required for the early steps of the metastatic cascade: invasion, tumor intravasation, and extravasation. Similarly, ECM molecules have been shown to be important for metastatic outgrowth. However, the role of ECM molecules on tumor dormancy and their contribution to the dormancy-supportive niches is not well understood. In this perspective article, we will summarize the current knowledge of ECM and its role in tumor metastasis and dormancy. We will discuss how a better understanding of the individual components of the ECM niche and their roles mediating the dormant state of disseminated tumor cells (DTCs) will advance the development of new therapies to target dormant cells and prevent metastasis outgrowth.

scholarly journals Iron-Bound Lipocalin-2 from Tumor-Associated Macrophages Drives Breast Cancer Progression Independent of Ferroportin

Metabolites ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 180
Author(s):  
Christina Mertens ◽  
Matthias Schnetz ◽  
Claudia Rehwald ◽  
Stephan Grein ◽  
Eiman Elwakeel ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Tumor Progression ◽  
Tumor Cells ◽  
Cancer Progression ◽  
Lung Metastases ◽  
Expression Profiles ◽  
The Cancer Genome Atlas ◽  
Lipocalin 2 ◽  
Tumor Associated Macrophages

Macrophages supply iron to the breast tumor microenvironment by enforced secretion of lipocalin-2 (Lcn-2)-bound iron as well as the increased expression of the iron exporter ferroportin (FPN). We aimed at identifying the contribution of each pathway in supplying iron for the growing tumor, thereby fostering tumor progression. Analyzing the expression profiles of Lcn-2 and FPN using the spontaneous polyoma-middle-T oncogene (PyMT) breast cancer model as well as mining publicly available TCGA (The Cancer Genome Atlas) and GEO Series(GSE) datasets from the Gene Expression Omnibus database (GEO), we found no association between tumor parameters and Lcn-2 or FPN. However, stromal/macrophage-expression of Lcn-2 correlated with tumor onset, lung metastases, and recurrence, whereas FPN did not. While the total iron amount in wildtype and Lcn-2−/− PyMT tumors showed no difference, we observed that tumor-associated macrophages from Lcn-2−/− compared to wildtype tumors stored more iron. In contrast, Lcn-2−/− tumor cells accumulated less iron than their wildtype counterparts, translating into a low migratory and proliferative capacity of Lcn-2−/− tumor cells in a 3D tumor spheroid model in vitro. Our data suggest a pivotal role of Lcn-2 in tumor iron-management, affecting tumor growth. This study underscores the role of iron for tumor progression and the need for a better understanding of iron-targeted therapy approaches.

scholarly journals The cancer glycocalyx mediates intravascular adhesion and extravasation during metastatic dissemination

2021 ◽  
Vol 4 (1) ◽  
Author(s):  
Giovanni S. Offeddu ◽  
Cynthia Hajal ◽  
Colleen R. Foley ◽  
Zhengpeng Wan ◽  
Lina Ibrahim ◽  
...  
Keyword(s):  
Hyaluronic Acid ◽  
Tumor Cells ◽  
Cancer Progression ◽  
Vascular System ◽  
Migration And Invasion ◽  
Improve Patient Survival ◽  
Adhesive Interactions ◽  
Vitro Model ◽  
Metastatic Sites

AbstractThe glycocalyx on tumor cells has been recently identified as an important driver for cancer progression, possibly providing critical opportunities for treatment. Metastasis, in particular, is often the limiting step in the survival to cancer, yet our understanding of how tumor cells escape the vascular system to initiate metastatic sites remains limited. Using an in vitro model of the human microvasculature, we assess here the importance of the tumor and vascular glycocalyces during tumor cell extravasation. Through selective manipulation of individual components of the glycocalyx, we reveal a mechanism whereby tumor cells prepare an adhesive vascular niche by depositing components of the glycocalyx along the endothelium. Accumulated hyaluronic acid shed by tumor cells subsequently mediates adhesion to the endothelium via the glycoprotein CD44. Trans-endothelial migration and invasion into the stroma occurs through binding of the isoform CD44v to components of the sub-endothelial extra-cellular matrix. Targeting of the hyaluronic acid-CD44 glycocalyx complex results in significant reduction in the extravasation of tumor cells. These studies provide evidence of tumor cells repurposing the glycocalyx to promote adhesive interactions leading to cancer progression. Such glycocalyx-mediated mechanisms may be therapeutically targeted to hinder metastasis and improve patient survival.

scholarly journals The differential role of reactive oxygen species in early and late stages of cancer

2017 ◽  
Vol 313 (6) ◽  
pp. R646-R653 ◽  
Author(s):  
Mohamad Assi
Keyword(s):  
Reactive Oxygen Species ◽  
Tumor Cells ◽  
Cancer Progression ◽  
Reactive Oxygen ◽  
Pentose Phosphate ◽  
Oxygen Species ◽  
Redox Biology ◽  
Oxidative Damages ◽  
Late Stages

The large doses of vitamins C and E and β-carotene used to reduce reactive oxygen species (ROS) production and oxidative damages in cancerous tissue have produced disappointing and contradictory results. This therapeutic conundrum was attributed to the double-faced role of ROS, notably, their ability to induce either proliferation or apoptosis of cancer cells. However, for a ROS-inhibitory approach to be effective, it must target ROS when they induce proliferation rather than apoptosis. On the basis of recent advances in redox biology, this review underlined a differential regulation of prooxidant and antioxidant system, respective to the stage of cancer. At early precancerous and neoplastic stages, antioxidant activity decreases and ROS appear to promote cancer initiation via inducing oxidative damage and base pair substitution mutations in prooncogenes and tumor suppressor genes, such as RAS and TP53, respectively. Whereas in late stages of cancer progression, tumor cells escape apoptosis by producing high levels of intracellular antioxidants, like NADPH and GSH, via the pentose phosphate pathway to buffer the excessive production of ROS and related intratumor oxidative injuries. Therefore, antioxidants should be prohibited in patients with advanced stages of cancer and/or undergoing anticancer therapies. Interestingly, the biochemical and biophysical properties of some polyphenols allow them to selectively recognize tumor cells. This characteristic was exploited to design and deliver nanoparticles coated with low doses of polyphenols and containing chemotherapeutic drugs into tumor-bearing animals. First results are encouraging, which may revolutionize the conventional use of antioxidants in cancer.

scholarly journals The Role of Protein Arginine Methyltransferase 1 in Gastrointestinal Cancers

2021 ◽  
Author(s):  
Jin Zou ◽  
Wei Shen ◽  
Yu Zhang ◽  
Shibo Ying
Keyword(s):  
Tumor Cells ◽  
Cancer Progression ◽  
Cancer Metastasis ◽  
Arginine Methylation ◽  
Gastrointestinal Tumors ◽  
Migration And Invasion ◽  
Arginine Methyltransferase ◽  
Tumorigenic Mechanism ◽  
Methyltransferase 1

Mammals can produce nine kinds of arginine methylation enzymes that can be divided into three types (I, II, and III) according to their catalytic activity. Arginine methyltransferase 1 (PRMT1), as the first discovered arginine methyltransferase type I, has been reported to be involved in cell signal transduction, DNA damage repair, RNA transcription and other processes. Its imbalance or abnormal expression is also involved in cancer metastasis. PRMT1 is highly expressed in gastrointestinal tumors and promotes tumor biomarkers expression, chemotherapy resistance and tumorigenicity to promote cancer progression, while downregulation of PRMT1 expression can inhibit the migration and invasion of related tumor cells or promote tumor cells apoptosis and inhibit the progression of cancer. Therefore, PRMT1 may be a cancer therapeutic target. In this paper, arginine methylase 1 expression in various types of gastrointestinal tumors, the tumorigenic mechanism and the role of PRMT1 in tumorigenesis and development were reviewed.

scholarly journals Role of Mitochondrial Cytochrome P450 2E1 in Healthy and Diseased Liver

Cells ◽  
2022 ◽  
Vol 11 (2) ◽  
pp. 288
Author(s):  
Julie Massart ◽  
Karima Begriche ◽  
Jessica H. Hartman ◽  
Bernard Fromenty
Keyword(s):  
Oxidative Stress ◽  
Cytochrome P450 ◽  
Liver Disease ◽  
Fatty Liver ◽  
Current Knowledge ◽  
Physiological Role ◽  
Experimental Investigations ◽  
Rat Liver Mitochondria ◽  
Cytochrome P450 2E1

Cytochrome P450 2E1 (CYP2E1) is pivotal in hepatotoxicity induced by alcohol abuse and different xenobiotics. In this setting, CYP2E1 generates reactive metabolites inducing oxidative stress, mitochondrial dysfunction and cell death. In addition, this enzyme appears to play a role in the progression of obesity-related fatty liver to nonalcoholic steatohepatitis. Indeed, increased CYP2E1 activity in nonalcoholic fatty liver disease (NAFLD) is deemed to induce reactive oxygen species overproduction, which in turn triggers oxidative stress, necroinflammation and fibrosis. In 1997, Avadhani’s group reported for the first time the presence of CYP2E1 in rat liver mitochondria, and subsequent investigations by other groups confirmed that mitochondrial CYP2E1 (mtCYP2E1) could be found in different experimental models. In this review, we first recall the main features of CYP2E1 including its role in the biotransformation of endogenous and exogenous molecules, the regulation of its expression and activity and its involvement in different liver diseases. Then, we present the current knowledge on the physiological role of mtCYP2E1, its contribution to xenobiotic biotransformation as well as the mechanism and regulation of CYP2E1 targeting to mitochondria. Finally, we discuss experimental investigations suggesting that mtCYP2E1 could have a role in alcohol-associated liver disease, xenobiotic-induced hepatotoxicity and NAFLD.

scholarly journals Hypoxia-inducible factor (HIF): fuel for cancer progression

2021 ◽  
Vol 14 ◽  
Author(s):  
Saurabh Satija ◽  
Harpreet Kaur ◽  
Murtaza M. Tambuwala ◽  
Prabal Sharma ◽  
Manish Vyas ◽  
...  
Keyword(s):  
Biological Sciences ◽  
Tumor Microenvironment ◽  
Tumor Cells ◽  
Cancer Progression ◽  
Oxygen Deficiency ◽  
Hypoxia Inducible Factor ◽  
Transcription Factor Activation ◽  
Underlying Mechanisms ◽  
Adaptive Reactions

Hypoxia is an integral part of tumor microenvironment, caused primarily due to rapidly multiplying tumor cells and a lack of proper blood supply. Among the major hypoxic pathways, HIF-1 transcription factor activation is one of the widely investigated pathways in the hypoxic tumor microenvironment (TME). HIF-1 is known to activate several adaptive reactions in response to oxygen deficiency in tumor cells. HIF-1 has two subunits, HIF-1β (constitutive) and HIF-1α (inducible). The HIF-1α expression is largely regulated via various cytokines (through PI3K-ACT-mTOR signals), which involves the cascading of several growth factors and oncogenic cascades. These events lead to the loss of cellular tumor suppressant activity through changes in the level of oxygen via oxygen-dependent and oxygen-independent pathways. The significant and crucial role of HIF in cancer progression and its underlying mechanisms have gained much attention lately among the translational researchers in the fields of cancer and biological sciences, which have enabled them to correlate these mchanisms with various other disease modalities. In the present review, we have summarized the key findings related to the role of HIF in the progression of tumors.

The Physiology, Pharmacology, and Biophysics of Ganglionic Transmission

1992 ◽  
Vol 70 (S1) ◽  
pp. S2
Author(s):  
Peter A. Smith ◽  
William F. Dryden ◽  
Canio Polosa ◽  
Vladimir I. Skok
Keyword(s):  
Medical Research ◽  
Brain Research ◽  
Physiological Role ◽  
Current Status ◽  
Autonomic Ganglia ◽  
Heritage Foundation ◽  
University Of Alberta ◽  
Neuroactive Peptides ◽  
Ganglionic Transmission

Over the last 20 years there has been a marked increase in the understanding of the biophysical properties of neurones in autonomic ganglia. During the same time period, there have been advances in immunohistochemistry which have shown that the autonomic ganglia are rich sources of a variety of neuroactive peptides and monoamines. Although physiological studies have underlined the role of enteric and prevertebral ganglia in the control of peristalsis and micturition, very little is known about the physiological role of many of the other autonomic ganglia.The objective of the International Brain Research Organization satellite symposium held in Edmonton, Alberta, during August 1991, was to bring together the biophysicists, morphologists, physiologists, and pharmacologists to evaluate the current status of our understanding of the autonomic ganglia. Posters and four sessions of invited talks were presented over a three-day period. The papers that appear in this issue detail the content of some of these talks.The organizers gratefully acknowledge the financial support provided by the Alberta Heritage Foundation for Medical Research, the Medical Research Council of Canada, Astra Pharma Inc., the University of Alberta Conference Fund, Nordic Laboratories, Merck Frosst Canada, Axon Instruments, Novopharm Ltd., Bio-Méga Inc., Chembiomed, Newport Instruments, the City of Edmonton, Charles River Canada, and Mandel Scientific.

scholarly journals Extracellular Chaperones as Novel Biomarkers of Overall Cancer Progression and Efficacy of Anticancer Therapy

2020 ◽  
Vol 10 (17) ◽  
pp. 6009
Author(s):  
Malgorzata Anna Krawczyk ◽  
Agata Pospieszynska ◽  
Małgorzata Styczewska ◽  
Ewa Bien ◽  
Sambor Sawicki ◽  
...  
Keyword(s):  
Cancer Progression ◽  
Current Knowledge ◽  
Therapeutic Targets ◽  
Age Group ◽  
Cancer Management ◽  
Novel Biomarkers ◽  
Immune System Regulation ◽  
New Biomarkers ◽  
Shock Proteins

Exosomal heat shock proteins (Hsps) are involved in intercellular communication both in physiological and pathological conditions. They play a role in key processes of carcinogenesis including immune system regulation, cell differentiation, vascular homeostasis and metastasis formation. Thus, exosomal Hsps are emerging biomarkers of malignancies and possible therapeutic targets. Adolescents and young adults (AYAs) are patients aged 15–39 years. This age group, placed between pediatric and adult oncology, pose a particular challenge for cancer management. New biomarkers of cancer growth and progression as well as prognostic factors are desperately needed in AYAs. In this review, we attempted to summarize the current knowledge on the role of exosomal Hsps in selected solid tumors characteristic for the AYA population and/or associated with poor prognosis in this age group. These included malignant melanoma, brain tumors, and breast, colorectal, thyroid, hepatocellular, lung and gynecological tract carcinomas. The studies on exosomal Hsps in these tumors are limited; however; some have provided promising results. Although further research is needed, there is potential for future clinical applications of exosomal Hsps in AYA cancers, both as novel biomarkers of disease presence, progression or relapse, or as therapeutic targets or tools for drug delivery.

scholarly journals Impact of nutrition on canine behaviour: current status and possible mechanisms

2007 ◽  
Vol 20 (2) ◽  
pp. 180-194 ◽  
Author(s):  
G. Bosch ◽  
B. Beerda ◽  
W. H. Hendriks ◽  
A. F. B. van der Poel ◽  
M. W. A. Verstegen
Keyword(s):  
Stress Resistance ◽  
Current Knowledge ◽  
Current Status ◽  
Contributing Factors ◽  
Problem Behaviour ◽  
Animal Shelters ◽  
Self Mutilation ◽  
Feeding Motivation ◽  
Underlying Mechanisms

Each year, millions of dogs worldwide are abandoned by their owners, relinquished to animal shelters, and euthanised because of behaviour problems. Nutrition is rarely considered as one of the possible contributing factors of problem behaviour. This contribution presents an overview of current knowledge on the influence of nutrition on canine behaviour and explores the underlying mechanisms by which diet may affect behaviour in animals. Behaviour is regulated by neurotransmitters and hormones, and changes in the availability of their precursors may influence behaviour. Tryptophan, the precursor of serotonin, may affect the incidence of aggression, self-mutilation and stress resistance. The latter may also be influenced by dietary tyrosine, a precursor to catecholamines. As diet composition, nutrient availability and nutrient interactions affect the availability of these precursors in the brain, behaviour or stress resistance may be affected. PUFA, especially DHA, have an important role as structural constituents in brain development, and dietary supply ofn-3 andn-6 PUFA could modify aspects of the dopaminergic and serotonergic system and, consequently, cognitive performance and behaviour. Finally, persistent feeding motivation between meals can increase stereotyped behaviour and aggression and decrease resting time. This feeding motivation may be altered by dietary fibre content and source. At present, few studies have been conducted to evaluate the role of nutrition in canine (problem) behaviour through the above mentioned mechanisms. Studies that explore this relationship may help to improve the welfare of dogs and their owners.

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