scholarly journals Iron as a Central Player and Promising Target in Cancer Progression

2019 ◽  
Vol 20 (2) ◽  
pp. 273 ◽  
Author(s):  
Michaela Jung ◽  
Christina Mertens ◽  
Elisa Tomat ◽  
Bernhard Brüne

Iron is an essential element for virtually all organisms. On the one hand, it facilitates cell proliferation and growth. On the other hand, iron may be detrimental due to its redox abilities, thereby contributing to free radical formation, which in turn may provoke oxidative stress and DNA damage. Iron also plays a crucial role in tumor progression and metastasis due to its major function in tumor cell survival and reprogramming of the tumor microenvironment. Therefore, pathways of iron acquisition, export, and storage are often perturbed in cancers, suggesting that targeting iron metabolic pathways might represent opportunities towards innovative approaches in cancer treatment. Recent evidence points to a crucial role of tumor-associated macrophages (TAMs) as a source of iron within the tumor microenvironment, implying that specifically targeting the TAM iron pool might add to the efficacy of tumor therapy. Here, we provide a brief summary of tumor cell iron metabolism and updated molecular mechanisms that regulate cellular and systemic iron homeostasis with regard to the development of cancer. Since iron adds to shaping major hallmarks of cancer, we emphasize innovative therapeutic strategies to address the iron pool of tumor cells or cells of the tumor microenvironment for the treatment of cancer.

2021 ◽  
Vol 11 ◽  
Author(s):  
Yang Liu ◽  
Ke Shi ◽  
Yong Chen ◽  
Xianrui Wu ◽  
Zheng Chen ◽  
...  

Exosomes from extracellular vesicles can activate or inhibit various signaling pathways by transporting proteins, lipids, nucleic acids and other substances to recipient cells. In addition, exosomes are considered to be involved in the development and progression of tumors from different tissue sources in numerous ways, including remodeling of the tumor microenvironment, promoting angiogenesis, metastasis, and invasion, and regulating the immune escape of tumor cells. However, the precise molecular mechanisms by which exosomes participate in these different processes remains unclear. In this review, we describe the research progress of tumor cell-derived exosomes in cancer progression. We also discuss the prospects of the application of exosomes combined with nanoengineered chemotherapeutic drugs in the treatment of cancer.


2018 ◽  
Vol 2018 ◽  
pp. 1-7 ◽  
Author(s):  
Yan-Zi Sun ◽  
Jun-Shan Ruan ◽  
Zong-Sheng Jiang ◽  
Ling Wang ◽  
Shao-Ming Wang

In recent years, the study of extracellular vesicles has been booming across various industries. Extracellular vesicles are considered one of the most important physiological endogenous carriers for the specific delivery of molecular information (nucleonic acid, cytokines, enzymes, etc.) between cells. It has been discovered that they perform a critical role in promoting tumor cell growth, proliferation, tumor cell invasion, and metastatic ability and regulating the tumor microenvironment to promote tumor cell communication and metastasis. In this review, we will discuss (1) the mechanism of extracellular vesicles generation, (2) their role in tumorigenesis and cancer progression (cell growth and proliferation, tumor microenvironment, epithelial-mesenchymal transition (EMT), invasion, and metastasis), (3) the role of extracellular vesicles in immune therapy, (4) extracellular vesicles targeting in tumor therapy, and (5) the role of extracellular vesicles as biomarkers. It is our hope that better knowledge and understanding of the extracellular vesicles will offer a wider range of effective therapeutic targets for experimental tumor research.


2021 ◽  
Vol 22 (20) ◽  
pp. 11221
Author(s):  
Nagaja Capitani ◽  
Laura Patrussi ◽  
Cosima T. Baldari

Similar to Janus, the two-faced god of Roman mythology, the tumor microenvironment operates two opposing and often conflicting activities, on the one hand fighting against tumor cells, while on the other hand, favoring their proliferation, survival and migration to other sites to establish metastases. In the tumor microenvironment, cytotoxic T cells—the specialized tumor-cell killers—also show this dual nature, operating their tumor-cell directed killing activities until they become exhausted and dysfunctional, a process promoted by cancer cells themselves. Here, we discuss the opposing activities of immune cells populating the tumor microenvironment in both cancer progression and anti-cancer responses, with a focus on cytotoxic T cells and on the molecular mechanisms responsible for the efficient suppression of their killing activities as a paradigm of the power of cancer cells to shape the microenvironment for their own survival and expansion.


2019 ◽  
Vol 2019 ◽  
pp. 1-8 ◽  
Author(s):  
Fengzhou Li ◽  
Shilei Zhao ◽  
Tao Guo ◽  
Jinxiu Li ◽  
Chundong Gu

Purpose.Leptin is a nutritional cytokine encoded by the obesity gene whose concentration in the tumor microenvironment is closely related to the occurrence and progression of cancer. However, previous evidence has suggested that there is no clear relationship between serum leptin concentrations and lung cancer progression. Cancer-associated fibroblasts (CAFs), the most abundant component of the tumor microenvironment in a variety of solid tumors, were recently reported to produce leptin. Therefore, it was inferred that leptin is most likely to affect non-small-cell lung cancer (NSCLC) through an autocrine and paracrine mechanism. In the current study, we investigated the paracrine effect and mechanism of leptin produced by CAFs on NSCLC by establishing a novel in vitro cell coculture system.Methods.A noncontact coculture device was designed and made by 3D printing. CAFs and paired normal lung fibroblasts (NLFs) from 5 patients were successfully isolated and cocultured with two NSCLC cell lines in a coculture system. The background expression of leptin was detected by western blot. The in situ expression of leptin and its receptor (Ob-R) in NSCLC tissues and paired normal lung tissues was analyzed by immunohistochemistry. Furthermore, we downregulated the expression of leptin in CAFs and assessed changes in its promotion on NSCLC cells in the coculture system. Finally, changes in the phosphorylation of ERK1/2 and AKT were examined to investigate the molecular mechanisms responsible for the paracrine promotion of NSCLC cells by leptin.Results.Leptin was overexpressed in nearly all five primary CAF lines compared with its expression in paired NLFs. IHC staining showed that the expression of leptin was high in NSCLC cells, slightly lower in CAF, and negative in normal lung tissue. Ob-R was strongly expressed in NSCLC cells. The ability of A549 and H1299 cells to proliferate and migrate was enhanced by high leptin levels in both the cocultured fibroblasts and the culture medium. Furthermore, western blot assays suggested that the MAPK/ERK1/2 and PI3K/AKT signaling pathways were activated by leptin produced by CAFs, which demonstrated that the functions of paracrine leptin in NSCLC are as those of the serum leptin to other cancers.Conclusion.Leptin produced by CAF promotes proliferation and migration of NSCLC cells probably via PI3K/AKT and MAPK/ERK1/2 signaling pathways in a paracrine manner.


2021 ◽  
Author(s):  
Yun-Ruei Kao ◽  
Jiahao Chen ◽  
Rajni Kumari ◽  
Madhuri Tatiparthy ◽  
Yuhong Ma ◽  
...  

Bone marrow resident and rarely dividing haematopoietic stem cells (HSC) harbour an extensive self-renewal capacity to sustain life-long blood formation; albeit their function declines during ageing. Various molecular mechanisms confer stem cell identity, ensure long-term maintenance and are known to be deregulated in aged stem cells. How these programs are coordinated, particularly during cell division, and what triggers their ageing-associated dysfunction has been unknown. Here, we demonstrate that HSC, containing the lowest amount of cytoplasmic chelatable iron (labile iron pool) among hematopoietic cells, activate a limited iron response during mitosis. Engagement of this iron homeostasis pathway elicits mobilization and β-oxidation of arachidonic acid and enhances stem cell-defining transcriptional programs governed by histone acetyl transferase Tip60/KAT5. We further find an age-associated expansion of the labile iron pool, along with loss of Tip60/KAT5-dependent gene regulation to contribute to the functional decline of ageing HSC, which can be mitigated by iron chelation. Together, our work reveals cytoplasmic redox active iron as a novel rheostat in adult stem cells; it demonstrates a role for the intracellular labile iron pool in coordinating a cascade of molecular events which reinforces HSC identity during cell division and to drive stem cell ageing when perturbed. As loss of iron homeostasis is commonly observed in the elderly, we anticipate these findings to trigger further studies into understanding and therapeutic mitigation of labile iron pool-dependent stem cell dysfunction in a wide range of degenerative and malignant pathologies.


Author(s):  
Pietro Poggio ◽  
Matteo Sorge ◽  
Laura Seclì ◽  
Mara Brancaccio

HSP90 is released by cancer cells in the tumor microenvironment where it associates with different co-chaperones generating complexes with specific functions, ranging from folding and activation of extracellular clients to the stimulation of cell surface receptors. Emerging data indicate that these functions are essential for tumor growth and progression. The understanding of the exact composition of extracellular HSP90 complexes and the molecular mechanisms at the basis of their functions in the tumor microenvironment may represent the first step to design innovative diagnostic tools and new effective therapies. Here we review the impact of extracellular HSP90 complexes on cancer cell signaling and behavior.


1996 ◽  
Vol 76 (1) ◽  
pp. 31-47 ◽  
Author(s):  
D. M. de Silva ◽  
C. C. Askwith ◽  
J. Kaplan

Iron serves essential functions in both prokaryotes and eukaryotes, and cells have highly specialized mechanisms for acquiring and handling this metal. The primary mechanism by which the concentration of iron in biologic systems is controlled is through the regulation of iron uptake. Although the role of transferrin in mammalian iron homeostasis has been well characterized, the study of genetic disorders of iron metabolism has revealed other, transferrin-independent, mechanisms by which cells can acquire iron. In an attempt to understand how eukaryotic systems take up this essential element, investigators have begun studying the simple eukaryote Saccharomyces cerevisiae. Several genes have been identified and cloned that act in concert to allow iron acquisition from the environment. Some of these genes appear to have functional homologues in human systems. This review focuses on the recent developments in understanding eukaryotic iron uptake with an emphasis on the genetic and molecular characterization of these systems in both cultured mammalian cells and S. cerevisiae. An unexpected connection between iron and copper homeostasis has been revealed by recent genetic studies, which confirm biologic observations made several decades ago.


Cells ◽  
2021 ◽  
Vol 10 (6) ◽  
pp. 1390
Author(s):  
Sistiana Aiello ◽  
Federica Casiraghi

Increased expression of the enzyme autotaxin (ATX) and the consequently increased levels of its product, lysophosphatidic acid (LPA), have been reported in several primary tumors. The role of LPA as a direct modulator of tumor cell functions—motility, invasion and migration capabilities as well as resistance to apoptotic death—has been recognized by numerous studies over the last two decades. Notably, evidence has recently been accumulating that shows that LPA also contributes to the development of the tumor microenvironment (TME). Indeed, LPA plays a crucial role in inducing angiogenesis and lymphangiogenesis, triggering cellular glycolytic shift and stimulating intratumoral fibrosis. In addition, LPA helps tumoral cells to escape immune surveillance. Treatments that counter the TME components, in order to deprive cancer cells of their crucial support, have been emerging among the promising new anticancer therapies. This review aims to summarize the latest knowledge on how LPA influences both tumor cell functions and the TME by regulating the activity of its different elements, highlighting why and how LPA is worth considering as a molecular target for new anticancer therapies.


Cancers ◽  
2021 ◽  
Vol 13 (24) ◽  
pp. 6330
Author(s):  
Alessia D’Aloia ◽  
Edoardo Arrigoni ◽  
Barbara Costa ◽  
Giovanna Berruti ◽  
Enzo Martegani ◽  
...  

RalGPS2 is a Ras-independent Guanine Nucleotide Exchange Factor for RalA GTPase that is involved in several cellular processes, including cytoskeletal organization. Previously, we demonstrated that RalGPS2 also plays a role in the formation of tunneling nanotubes (TNTs) in bladder cancer 5637 cells. In particular, TNTs are a novel mechanism of cell–cell communication in the tumor microenvironment, playing a central role in cancer progression and metastasis formation. However, the molecular mechanisms involved in TNTs formation still need to be fully elucidated. Here we demonstrate that mid and high-stage bladder cancer cell lines have functional TNTs, which can transfer mitochondria. Moreover, using confocal fluorescence time-lapse microscopy, we show in 5637 cells that TNTs mediate the trafficking of RalA protein and transmembrane MHC class III protein leukocyte-specific transcript 1 (LST1). Furthermore, we show that RalGPS2 is essential for nanotubes generation, and stress conditions boost its expression both in 5637 and HEK293 cell lines. Finally, we prove that RalGPS2 interacts with Akt and PDK1, in addition to LST1 and RalA, leading to the formation of a complex that promotes nanotubes formation. In conclusion, our findings suggest that in the tumor microenvironment, RalGPS2 orchestrates the assembly of multimolecular complexes that drive the formation of TNTs.


2020 ◽  
Vol 21 (3) ◽  
pp. 957 ◽  
Author(s):  
Hui Zhong ◽  
Yifan Lai ◽  
Rui Zhang ◽  
Abdelkader Daoud ◽  
Qingyuan Feng ◽  
...  

The tumor microenvironment has been recently recognized as a critical contributor to cancer progression and anticancer therapy-resistance. Cyclophosphamide (CTX) is a cytotoxic agent commonly used in clinics for the treatment of cancer. Previous reports demonstrated that CTX given at low continuous doses, known as metronomic schedule, mainly targets endothelial cells and circulating Tregs with unknown mechanisms. Here, we investigated the antitumor activity of two different metronomic schedules of CTX along with their corresponding MTD regimen and further explored their effect on immune function and tumor microenvironment. Toxicity evaluation was monitored by overall survival rate, weight loss, and histopathological analysis. A nude mouse model of Lewis lung cancer was established to assess the anti-metastatic effects of CTX in vivo. CD4+, CD8+, and CD4+CD25+FoxP3 T cells were selected by flow cytometry analysis. Low and continuous administration of CTX was able to restore immune function via increase of CD4+/CD8+ T cells and depletion of T regulatory cells, not only in circulatory and splenic compartments, but also at the tumor site. Low-dose CTX also reduced myofibroblasts, accompanied with an increased level of E-cadherin and low N-cadherin, both in the primary tumor and lung through the TGF-β pathway by the downregulated expression of TGF-β receptor 2. Our data may indicate that several other molecular mechanisms of CTX for tumor may be involved in metronomic chemotherapy, besides targeting angiogenesis and regulatory T cells.


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