scholarly journals Extracellular MicroRNAs as Intercellular Mediators and Noninvasive Biomarkers of Cancer

Cancers ◽  
2020 ◽  
Vol 12 (11) ◽  
pp. 3455
Author(s):  
Blanca Ortiz-Quintero

MicroRNAs (miRNAs) are released by different types of cells through highly regulated mechanisms under normal and pathological conditions. These extracellular miRNAs can be delivered into recipient cells for functional purposes, acting as cell-to-cell signaling mediators. It has been discovered that cancer cells release miRNAs into their surroundings, targeting normal cells or other cancer cells, presumably to promote tumor development and progression. These extracellular miRNAs are associated with oncogenic mechanisms and, because they can be quantified in blood and other bodily fluids, may be suitable noninvasive biomarkers for cancer detection. This review summarizes recent evidence of the role of extracellular miRNAs as intercellular mediators, with an emphasis on their role in the mechanisms of tumor development and progression and their potential value as biomarkers in solid tumors. It also highlights the biological characteristics of extracellular miRNAs that enable them to function as regulators of gene expression, such as biogenesis, gene silencing mechanisms, subcellular compartmentalization, and the functions and mechanisms of release.

2020 ◽  
Author(s):  
Guillaume Jacquemin ◽  
Annabelle Wurmser ◽  
Mathilde Huyghe ◽  
Wenjie Sun ◽  
Meghan Perkins ◽  
...  

AbstractTumours are complex ecosystems composed of different types of cells that communicate and influence each other. While the critical role of stromal cells in affecting tumour growth is well established, the impact of mutant cancer cells on healthy surrounding tissues remains poorly defined. Here, we uncovered a paracrine mechanism by which intestinal cancer cells reactivate foetal and regenerative Yap-associated transcriptional programs in neighbouring wildtype epithelial cells, rendering them adapted to thrive in the tumour context. We identified the glycoprotein Thrombospondin-1 (Thbs1) as the essential factor that mediates non-cell autonomous morphological and transcriptional responses. Importantly, Thbs1 is associated with bad prognosis in several human cancers. This study reveals the Thbs1-YAP axis as the mechanistic link mediating paracrine interactions between epithelial cells, promoting tumour formation and progression.


2021 ◽  
Vol 22 ◽  
Author(s):  
Diana Duarte ◽  
Nuno Vale

: Antimalarial drugs from different classes have demonstrated anticancer effects in different types of cancer cells, but their complete mode of action in cancer remains unknown. Recently, several studies reported the important role of palmitoyl-protein thioesterase 1 (PPT1), a lysosomal enzyme, as the molecular target of chloroquine and its derivates in cancer. It was also found that PPT1 is overexpressed in different types of cancer, such as breast, colon, etc. Our group has found a synergistic interaction between antimalarial drugs, such as mefloquine, artesunate and chloroquine and antineoplastic drugs in breast cancer cells, but the mechanism of action was not determined. Here, we describe the importance of autophagy and lysosomal inhibitors in tumorigenesis and hypothesize that other antimalarial agents besides chloroquine could also interact with PPT1 and inhibit the mechanistic target of rapamycin (mTOR) signalling, an important pathway in cancer progression. We believe that PPT1 inhibition results in changes in the lysosomal metabolism that result in less accumulation of antineoplastic drugs in lysosomes, which increases the bioavailability of the antineoplastic agents. Taken together, these mechanisms help to explain the synergism of antimalarial and antineoplastic agents in cancer cells.


Cancers ◽  
2020 ◽  
Vol 12 (8) ◽  
pp. 2107 ◽  
Author(s):  
Ralf Hass

The tumor microenvironment represents a dynamically composed matrix in which tissue-associated cancer cells are embedded together with a variety of further cell types to form a more or less separate organ-like structure. Constantly mutual interactions between cells of the tumor microenvironment promote continuous restructuring and growth in the tumor. A distinct organization of the tumor stroma also facilitates the formation of transient cancer stem cell niches, thereby contributing to progressive and dynamic tumor development. An important but heterogeneous mixture of cells that communicates among the cancer cells and the different tumor-associated cell types is represented by mesenchymal stroma-/stem-like cells (MSC). Following recruitment to tumor sites, MSC can change their functionalities, adapt to the tumor’s metabolism, undergo differentiation and synergize with cancer cells. Vice versa, cancer cells can alter therapeutic sensitivities and change metastatic behavior depending on the type and intensity of this MSC crosstalk. Thus, close cellular interactions between MSC and cancer cells can eventually promote cell fusion by forming new cancer hybrid cells. Consequently, newly acquired cancer cell functions or new hybrid cancer populations enlarge the plasticity of the tumor and counteract successful interventional strategies. The present review article highlights some important features of MSC within the tumor stroma.


2019 ◽  
Vol 20 (10) ◽  
pp. 2603 ◽  
Author(s):  
Yaara Gorzalczany ◽  
Ronit Sagi-Eisenberg

Accumulating evidence has highlighted the accumulation of mast cells (MCs) in tumors. However, their impact on tumor development remained controversial. Indeed, cumulative data indicate an enigmatic role for MCs in cancer, whereby depending on the circumstances, which still need to be resolved, MCs function to promote or restrict tumor growth. By responding to multiple stimuli MCs release multiple inflammatory mediators, that contribute to the resolution of infection and resistance to envenomation, but also have the potency to promote or inhibit malignancy. Thus, MCs seem to possess the power to define tumor projections. Given this remarkable plasticity of MC responsiveness, there is an urgent need of understanding how MCs are activated in the tumor microenvironment (TME). We have recently reported on the direct activation of MCs upon contact with cancer cells by a mechanism involving an autocrine formation of adenosine and signaling by the A3 adenosine receptor. Here we summarized the evidence on the role of adenosine signaling in cancer, in MC mediated inflammation and in the MC-cancer crosstalk.


2000 ◽  
Vol 18 (13) ◽  
pp. 2626-2634 ◽  
Author(s):  
Matthew Meyerson

ABSTRACT: Shortening of the telomeric DNA at chromosome ends is postulated to limit the lifespan of human cells. In contrast, activation of telomerase, the enzyme that synthesizes telomeric DNA, is proposed to be an essential step in cancer cell immortalization and cancer progression. This review discusses the structure and function of telomeres and telomerase, the role of telomerase in cell immortalization, and the effects of telomerase inactivation on normal and cancer cells. Moreover, data on the experimental use of telomerase assays for cancer detection and diagnosis are reviewed. Finally, the review considers the evidence regarding whether telomerase inhibitors could be used to treat human cancers.


2020 ◽  
Vol 10 (6-s) ◽  
pp. 183-185
Author(s):  
Rajashri Champanery ◽  
Drashti Joshi

The tumor suppressor TP53 gene is one of the most frequently mutated in different types of human cancer. Particularly in colorectal cancer (CRC), it is believed that TP53 mutations play a role in the adenoma-carcinoma transition of tumors during pathological process. The TP53 mutation is the key step driving the transition from adenoma to adenocarcinoma. The functional roles of TP53 mutation in tumor development have been comprehensively investigated. In this mini review, we comprehensively summarize the p53 mutants in CRC progression and discuss the current strategies for p53 mutants in malignancies. Keywords: p53 mutants, colorectal cancer, Tp53 mutation


Cancers ◽  
2022 ◽  
Vol 14 (1) ◽  
pp. 228
Author(s):  
Angeliki Karagiota ◽  
Georgia Chachami ◽  
Efrosyni Paraskeva

Altered lipid metabolism is an emerging hallmark of aggressive tumors, as rapidly proliferating cancer cells reprogram fatty acid (FA) uptake, synthesis, storage, and usage to meet their increased energy demands. Central to these adaptive changes, is the conversion of excess FA to neutral triacylglycerides (TAG) and their storage in lipid droplets (LDs). Acylglycerolphosphate acyltransferases (AGPATs), also known as lysophosphatidic acid acyltransferases (LPAATs), are a family of five enzymes that catalyze the conversion of lysophosphatidic acid (LPA) to phosphatidic acid (PA), the second step of the TAG biosynthesis pathway. PA, apart from its role as an intermediate in TAG synthesis, is also a precursor of glycerophospholipids and a cell signaling molecule. Although the different AGPAT isoforms catalyze the same reaction, they appear to have unique non-overlapping roles possibly determined by their distinct tissue expression and substrate specificity. This is best exemplified by the role of AGPAT2 in the development of type 1 congenital generalized lipodystrophy (CGL) and is also manifested by recent studies highlighting the involvement of AGPATs in the physiology and pathology of various tissues and organs. Importantly, AGPAT isoform expression has been shown to enhance proliferation and chemoresistance of cancer cells and correlates with increased risk of tumor development or aggressive phenotypes of several types of tumors.


Chemotherapy ◽  
2018 ◽  
Vol 63 (5) ◽  
pp. 262-271 ◽  
Author(s):  
Yajie Cui ◽  
Li Qin ◽  
Defu Tian ◽  
Ting Wang ◽  
Lijing Fan ◽  
...  

Ovarian cancer is one of the deadliest gynecological malignancies in women. Chemoresistance has been a major obstacle for ovarian cancer treatment. Zinc finger E-box-binding homeobox 1 (ZEB1) is an important regulator of tumor development in various types of cancer. Abnormal expression of SLC3A2 (CD98hc), a type 2 transmembrane cell surface molecule, has been described in several cancers. This study was designed to investigate the role of ZEB1 and SLC3A2 in the chemoresistance to cisplatin in ovarian cancer cells. We found that ZEB1 was increased in cisplatin-resistant SKOV3/DPP cells. Downregulation of ZEB1 significantly decreased cell viability in response to cisplatin, increased cis­platin-induced apoptosis, and decreased migration and invasion in the presence of cisplatin. In addition, downregulation of ZEB1 decreased the volume and weight of implanted tumors. SLC3A2 was decreased in cisplatin-resistant SKOV3/DPP cells. Upregulation of SLC3A2 significantly decreased cell viability in response to cisplatin, increased cisplatin-induced apoptosis, and decreased migration and invasion in the presence of cisplatin. Moreover, upregulation of SLC3A2 decreased the volume and weight of implanted tumors. Downregulation of ZEB1 resulted in a significant increase of SLC3A2 expression. Moreover, downregulation of SLC3A2 significantly inhibited ZEB1 knockdown-mediated inhibition of cisplatin-resistance. ZEB1-mediated regulation of SLC3A2 was involved in the chemoresistance to cisplatin in ovarian cancer cells. Overall, we provide new insights into the mechanism of chemoresistance to cisplatin in ovarian cancer cells. ZEB1/SLC3A2 may be promising therapeutic targets for enhancement of the sensitivity of ovarian cancer cells to cisplatin-mediated chemotherapy.


Cells ◽  
2019 ◽  
Vol 9 (1) ◽  
pp. 29 ◽  
Author(s):  
Hyun Ah Seo ◽  
Sokviseth Moeng ◽  
Seokmin Sim ◽  
Hyo Jeong Kuh ◽  
Soo Young Choi ◽  
...  

The susceptibility of cancer cells to different types of treatments can be restricted by intrinsic and acquired therapeutic resistance, leading to the failure of cancer regression and remission. To overcome this problem, a combination therapy has been proposed as a fundamental strategy to improve therapeutic responses; however, resistance is still unavoidable. MicroRNA (miRNAs) are associated with cancer therapeutic resistance. The modulation of dysregulated miRNA levels through miRNA-based therapy comprising a replacement or inhibition approach has been proposed to sensitize cancer cells to other anti-cancer therapies. The combination of miRNA-based therapy with other anti-cancer therapies (miRNA-based combinatorial cancer therapy) is attractive, due to the ability of miRNAs to target multiple genes associated with the signaling pathways controlling therapeutic resistance. In this article, we present an overview of recent findings on the role of therapeutic resistance-related miRNAs in different types of cancer. We review the feasibility of utilizing dysregulated miRNAs in cancer cells and extracellular vesicles as potential candidates for miRNA-based combinatorial cancer therapy. We also discuss innate properties of miRNAs that need to be considered for more effective combinatorial cancer therapy.


2018 ◽  
Vol 2018 ◽  
pp. 1-8 ◽  
Author(s):  
Huijuan Ma ◽  
Chang-Qing Xia

Myeloid-derived suppressor cells (MDSCs) are identified as a heterogeneous population of cells with the function to suppress innate as well as adaptive immune responses. The initial studies of MDSCs were primarily focused on the field of animal tumor models or cancer patients. In cancer, MDSCs play the deleterious role to inhibit tumor immunity and to promote tumor development. Over the past few years, an increasing number of studies have investigated the role of MDSCs in autoimmune diseases. The beneficial effects of MDSCs in autoimmunity have been reported by some studies, and thus, immunosuppressive MDSCs may be a novel therapeutic target in autoimmune diseases. There are some controversial findings as well. Many questions such as the activation, differentiation, and suppressive functions of MDSCs and their roles in autoimmune diseases remain unclear. In this review, we have discussed the current understanding of MDSCs in autoimmune diseases.


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