Telomeres, telomerase, and apoptosis

2004 ◽  
Vol 82 (4) ◽  
pp. 498-507 ◽  
Author(s):  
Chiara Mondello ◽  
A Ivana Scovassi
Keyword(s):  
Cancer Cells ◽  
Telomerase Activity ◽  
Telomeric Dna ◽  
Apoptotic Response ◽  
Reverse Transcriptase Enzyme ◽  
Limited Life ◽  
Specific Proteins ◽  
Telomere Capping ◽  
The Impact ◽  
High Order Chromatin

Telomeres are specialized high-order chromatin structures that cap the ends of eukaryotic chromosomes. In vertebrates, telomeric DNA is composed of repetitions of the TTAGGG hexanucleotide, is bound to a set of specific proteins, and is elongated by the reverse transcriptase enzyme telomerase. Telomerase activity is promptly detected in cells with an indefinite replicative potential, such as cancer cells, while is almost undetectable in normal cells, which are characterized by a limited life span. Mounting evidence indicates that the maintenance of telomere integrity and telomerase protect cells from apoptosis. Disruption of the telomere capping function and (or) telomerase inhibition elicit an apoptotic response in cancer cells, while restoration of telomerase activity in somatic cells confers resistance to apoptosis. The possible mechanisms linking telomeres, telomerase and apoptosis are discussed in this review, together with the impact of this field in anticancer research.Key words: telomeres, telomerase, telomeric proteins, apoptosis, tumorigenesis.

The Impact of Antioxidants from the Diet on Breast Cancer Cells Monitored by Raman Microspectroscopy

2018 ◽  
Vol 16 (2) ◽  
pp. 127-137
Author(s):  
Paula Sofia Coutinho Medeiros ◽  
Ana Lúcia Marques Batista de Carvalho ◽  
Cristina Ruano ◽  
Juan Carlos Otero ◽  
Maria Paula Matos Marques
Keyword(s):  
Breast Cancer ◽  
Cancer Cells ◽  
Cell Line ◽  
Breast Cancer Cells ◽  
Triple Negative ◽  
Breast Adenocarcinoma ◽  
Coumaric Acid ◽  
Human Breast ◽  
The Impact

Background: The impact of the ubiquitous dietary phenolic compound p-coumaric acid on human breast cancer cells was assessed, through a multidisciplinary approach: Combined biological assays for cytotoxicity evaluation and biochemical profiling by Raman microspectroscopic analysis in cells. </P><P> Methods: Para-coumaric acid was shown to exert in vitro chemoprotective and antitumor activities, depending on the concentration and cell line probed: a significant anti-invasive ability was detected for the triple-negative MDA-MB-231 cells, while a high pro-oxidant effect was found for the estrogen- dependent MCF-7 cells. A striking cell selectivity was obtained, with a more noticeable outcome on the triple-negative MDA-MB-231 cell line. Results: The main impact on the cellular biochemical profile was verified to be on proteins and lipids, thus justifying the compound´s anti-invasive effect and chemoprotective ability. Conclusion: p-Coumaric acid was thus shown to be a promising chemoprotective/chemotherapeutic agent, particularly against the low prognosis triple-negative human breast adenocarcinoma.

scholarly journals Oxidative Stress in the Tumor Microenvironment and Its Relevance to Cancer Immunotherapy

Cancers ◽  
2021 ◽  
Vol 13 (5) ◽  
pp. 986
Author(s):  
Nada S. Aboelella ◽  
Caitlin Brandle ◽  
Timothy Kim ◽  
Zhi-Chun Ding ◽  
Gang Zhou
Keyword(s):  
Oxidative Stress ◽  
Tumor Microenvironment ◽  
Cancer Cells ◽  
Redox Homeostasis ◽  
Tumor Rejection ◽  
Oxygen Species ◽  
Antitumor Effects ◽  
Key Drivers ◽  
Cancer Immunotherapies ◽  
The Impact

It has been well-established that cancer cells are under constant oxidative stress, as reflected by elevated basal level of reactive oxygen species (ROS), due to increased metabolism driven by aberrant cell growth. Cancer cells can adapt to maintain redox homeostasis through a variety of mechanisms. The prevalent perception about ROS is that they are one of the key drivers promoting tumor initiation, progression, metastasis, and drug resistance. Based on this notion, numerous antioxidants that aim to mitigate tumor oxidative stress have been tested for cancer prevention or treatment, although the effectiveness of this strategy has yet to be established. In recent years, it has been increasingly appreciated that ROS have a complex, multifaceted role in the tumor microenvironment (TME), and that tumor redox can be targeted to amplify oxidative stress inside the tumor to cause tumor destruction. Accumulating evidence indicates that cancer immunotherapies can alter tumor redox to intensify tumor oxidative stress, resulting in ROS-dependent tumor rejection. Herein we review the recent progresses regarding the impact of ROS on cancer cells and various immune cells in the TME, and discuss the emerging ROS-modulating strategies that can be used in combination with cancer immunotherapies to achieve enhanced antitumor effects.

scholarly journals Aberrant Bcl-x splicing in cancer: from molecular mechanism to therapeutic modulation

2021 ◽  
Vol 40 (1) ◽  
Author(s):  
Zhihui Dou ◽  
Dapeng Zhao ◽  
Xiaohua Chen ◽  
Caipeng Xu ◽  
Xiaodong Jin ◽  
...  
Keyword(s):  
Cancer Cells ◽  
Human Cancer ◽  
Structural Characteristics ◽  
Therapy Resistance ◽  
Regulatory Elements ◽  
Aberrant Splicing ◽  
Clinical Role ◽  
Splicing Isoforms ◽  
The Impact ◽  
Splicing Patterns

AbstractBcl-x pre-mRNA splicing serves as a typical example to study the impact of alternative splicing in the modulation of cell death. Dysregulation of Bcl-x apoptotic isoforms caused by precarious equilibrium splicing is implicated in genesis and development of multiple human diseases, especially cancers. Exploring the mechanism of Bcl-x splicing and regulation has provided insight into the development of drugs that could contribute to sensitivity of cancer cells to death. On this basis, we review the multiple splicing patterns and structural characteristics of Bcl-x. Additionally, we outline the cis-regulatory elements, trans-acting factors as well as epigenetic modifications involved in the splicing regulation of Bcl-x. Furthermore, this review highlights aberrant splicing of Bcl-x involved in apoptosis evade, autophagy, metastasis, and therapy resistance of various cancer cells. Last, emphasis is given to the clinical role of targeting Bcl-x splicing correction in human cancer based on the splice-switching oligonucleotides, small molecular modulators and BH3 mimetics. Thus, it is highlighting significance of aberrant splicing isoforms of Bcl-x as targets for cancer therapy.

scholarly journals Mitochondrial O-GlcNAc Transferase Interacts with and Modifies Many Proteins and Its Up-Regulation Affects Mitochondrial Function and Cellular Energy Homeostasis

Cancers ◽  
2021 ◽  
Vol 13 (12) ◽  
pp. 2956
Author(s):  
Paweł Jóźwiak ◽  
Piotr Ciesielski ◽  
Piotr K. Zakrzewski ◽  
Karolina Kozal ◽  
Joanna Oracz ◽  
...  
Keyword(s):  
Cancer Cells ◽  
Energy Homeostasis ◽  
Glucose Sensor ◽  
Single Gene ◽  
Mitochondrial Proteins ◽  
Mitochondrial Activity ◽  
Ros Generation ◽  
Inner Mitochondrial Membrane ◽  
Glcnac Transferase ◽  
The Impact

O-GlcNAcylation is a cell glucose sensor. The addition of O-GlcNAc moieties to target protein is catalyzed by the O-Linked N-acetylglucosamine transferase (OGT). OGT is encoded by a single gene that yields differentially spliced OGT isoforms. One of them is targeted to mitochondria (mOGT). Although the impact of O-GlcNAcylation on cancer cells biology is well documented, mOGT’s role remains poorly investigated. We performed studies using breast cancer cells with up-regulated mOGT or its catalytic inactive mutant to identify proteins specifically modified by mOGT. Proteomic approaches included isolation of mOGT protein partners and O-GlcNAcylated proteins from mitochondria-enriched fraction followed by their analysis by mass spectrometry. Moreover, we analyzed the impact of mOGT dysregulation on mitochondrial activity and cellular metabolism using a variety of biochemical assays. We found that mitochondrial OGT expression is glucose-dependent. Elevated mOGT expression affected the mitochondrial transmembrane potential and increased intramitochondrial ROS generation. Moreover, mOGT up-regulation caused a decrease in cellular ATP level. We identified many mitochondrial proteins as mOGT substrates. Most of these proteins are localized in the mitochondrial matrix and the inner mitochondrial membrane and participate in mitochondrial respiration, fatty acid metabolism, transport, translation, apoptosis, and mtDNA processes. Our findings suggest that mOGT interacts with and modifies many mitochondrial proteins, and its dysregulation affects cellular bioenergetics and mitochondria function.

scholarly journals Seeding of breast cancer cell line (MDA-MB-231LUC+) to the mandible induces overexpression of substance P and CGRP throughout the trigeminal ganglion and widespread peripheral sensory neuropathy throughout all three of its divisions

2021 ◽  
Vol 17 ◽  
pp. 174480692110240
Author(s):  
Silvia Gutierrez ◽  
James C Eisenach ◽  
M Danilo Boada
Keyword(s):  
Breast Cancer ◽  
Substance P ◽  
Cancer Cells ◽  
Cell Line ◽  
Cancer Cell ◽  
Breast Cancer Cell ◽  
Trigeminal Ganglion ◽  
Breast Cancer Cell Line ◽  
Cancer Cell Line ◽  
The Impact

Some types of cancer are commonly associated with intense pain even at the early stages of the disease. The mandible is particularly vulnerable to metastasis from breast cancer, and this process has been studied using a bioluminescent human breast cancer cell line (MDA-MB-231LUC+). Using this cell line and anatomic and neurophysiologic methods in the trigeminal ganglion (TG), we examined the impact of cancer seeding in the mandible on behavioral evidence of hypersensitivity and on trigeminal sensory neurons. Growth of cancer cells seeded to the mandible after arterial injection of the breast cancer cell line in Foxn1 animals (allogeneic model) induced behavioral hypersensitivity to mechanical stimulation of the whisker pad and desensitization of tactile and sensitization of nociceptive mechanically sensitive afferents. These changes were not restricted to the site of metastasis but extended to sensory afferents in all three divisions of the TG, accompanied by widespread overexpression of substance P and CGRP in neurons through the ganglion. Subcutaneous injection of supernatant from the MDA-MB-231LUC+ cell culture in normal animals mimicked some of the changes in mechanically responsive afferents observed with mandibular metastasis. We conclude that released products from these cancer cells in the mandible are critical for the development of cancer-induced pain and that the overall response of the system greatly surpasses these local effects, consistent with the widespread distribution of pain in patients. The mechanisms of neuronal plasticity likely occur in the TG itself and are not restricted to afferents exposed to the metastatic cancer microenvironment.

scholarly journals Functional antagonism of chromatin modulators regulates epithelial-mesenchymal transition

2021 ◽  
Vol 7 (9) ◽  
pp. eabd7974
Author(s):  
Michela Serresi ◽  
Sonia Kertalli ◽  
Lifei Li ◽  
Matthias Jürgen Schmitt ◽  
Yuliia Dramaretska ◽  
...  
Keyword(s):  
Cancer Cells ◽  
Transcriptional Control ◽  
Molecular Mechanisms ◽  
Developmental Process ◽  
Epithelial Mesenchymal Transition ◽  
Chromatin Remodelers ◽  
Mesenchymal Transition ◽  
Signature Genes ◽  
Chromatin Regulators ◽  
The Impact

Epithelial-mesenchymal transition (EMT) is a developmental process hijacked by cancer cells to modulate proliferation, migration, and stress response. Whereas kinase signaling is believed to be an EMT driver, the molecular mechanisms underlying epithelial-mesenchymal interconversion are incompletely understood. Here, we show that the impact of chromatin regulators on EMT interconversion is broader than that of kinases. By combining pharmacological modulation of EMT, synthetic genetic tracing, and CRISPR interference screens, we uncovered a minority of kinases and several chromatin remodelers, writers, and readers governing homeostatic EMT in lung cancer cells. Loss of ARID1A, DOT1L, BRD2, and ZMYND8 had nondeterministic and sometimes opposite consequences on epithelial-mesenchymal interconversion. Together with RNAPII and AP-1, these antagonistic gatekeepers control chromatin of active enhancers, including pan-cancer-EMT signature genes enabling supraclassification of anatomically diverse tumors. Thus, our data uncover general principles underlying transcriptional control of cancer cell plasticity and offer a platform to systematically explore chromatin regulators in tumor-state–specific therapy.

scholarly journals The metabolic adaptation mechanism of metastatic organotropism

2021 ◽  
Vol 10 (1) ◽  
Author(s):  
Chao Wang ◽  
Daya Luo
Keyword(s):  
Cancer Cells ◽  
Cancer Cell ◽  
Cancer Progression ◽  
Cancer Metabolism ◽  
Cancer Metastasis ◽  
Tumour Microenvironment ◽  
Metabolic Adaptation ◽  
Adaptation Mechanism ◽  
Metastatic Sites ◽  
The Impact

AbstractMetastasis is a complex multistep cascade of cancer cell extravasation and invasion, in which metabolism plays an important role. Recently, a metabolic adaptation mechanism of cancer metastasis has been proposed as an emerging model of the interaction between cancer cells and the host microenvironment, revealing a deep and extensive relationship between cancer metabolism and cancer metastasis. However, research on how the host microenvironment affects cancer metabolism is mostly limited to the impact of the local tumour microenvironment at the primary site. There are few studies on how differences between the primary and secondary microenvironments promote metabolic changes during cancer progression or how secondary microenvironments affect cancer cell metastasis preference. Hence, we discuss how cancer cells adapt to and colonize in the metabolic microenvironments of different metastatic sites to establish a metastatic organotropism phenotype. The mechanism is expected to accelerate the research of cancer metabolism in the secondary microenvironment, and provides theoretical support for the generation of innovative therapeutic targets for clinical metastatic diseases.

scholarly journals Survivin drives tumor-associated macrophage reprogramming: a novel mechanism with potential impact for obesity

2021 ◽  
Author(s):  
E. Benaiges ◽  
V. Ceperuelo-Mallafré ◽  
A. Madeira ◽  
R. Bosch ◽  
C. Núñez-Roa ◽  
...  
Keyword(s):  
Cancer Cells ◽  
Expression Patterns ◽  
Intracellular Localization ◽  
Immunohistochemical Analysis ◽  
Subcellular Fractionation ◽  
Migration And Invasion ◽  
Macrophage Phenotype ◽  
Tumor Associated Macrophages ◽  
Obesity And Cancer ◽  
The Impact

Abstract Purpose Recent studies point to adipose-derived stem cells (ASCs) as a link between obesity and cancer. We aimed to determine whether survivin, which is highly secreted by ASCs from subjects with obesity, might drive a pro-tumoral phenotype in macrophages. Methods The effect of ASC conditioned medium on the macrophage phenotype was assessed by expression studies. Survivin intracellular localization and internalization were examined by subcellular fractionation and immunofluorescence, respectively. Loss- and gain-of-function studies were performed using adenoviral vectors, and gene expression patterns, migration and invasion capacities of cancer cells were examined. Heterotypic cultures of ASCs, macrophages and cancer cells were established to mimic the tumor microenvironment. Survivin-blocking experiments were used to determine the impact of survivin on both macrophages and cancer cells. Immunohistochemical analysis of survivin was performed in macrophages from ascitic fluids of cancer patients and healthy controls. Results We found that obese-derived ASCs induced a phenotypic switch in macrophages characterized by the expression of both pro- and anti-inflammatory markers. Macrophages were found to internalize extracellular survivin, generating hybrid macrophages with a tumor-associated phenotype that included secretion of survivin. Exogenous expression of survivin in macrophages generated a similar phenotype and enhanced the malignant characteristics of cancer cells by a mechanism dependent on survivin phosphorylation at threonine 34. Survivin secreted by both ASCs from subjects with obesity and tumor-associated macrophages synergistically boosted the malignancy of cancer cells. Importantly, survivin was mainly detected in ascites-associated macrophages from patients with a malignant diagnosis. Conclusion Our data indicate that survivin may serve as a molecular link between obesity and cancer and as a novel marker for tumor-associated macrophages.

scholarly journals An Efficient Photodynamic Therapy Treatment for Human Pancreatic Adenocarcinoma

2020 ◽  
Vol 9 (1) ◽  
pp. 192 ◽  
Author(s):  
Alexandre Quilbe ◽  
Olivier Moralès ◽  
Martha Baydoun ◽  
Abhishek Kumar ◽  
Rami Mustapha ◽  
...  
Keyword(s):  
Pancreatic Cancer ◽  
Photodynamic Therapy ◽  
Immune System ◽  
Cancer Cells ◽  
Pancreatic Adenocarcinoma ◽  
Cell Lines ◽  
Folate Receptor ◽  
Mice Model ◽  
Gene And Protein Expression ◽  
The Impact

To date, pancreatic adenocarcinoma (ADKP) is a devastating disease for which the incidence rate is close to the mortality rate. The survival rate has evolved only 2–5% in 45 years, highlighting the failure of current therapies. Otherwise, the use of photodynamic therapy (PDT), based on the use of an adapted photosensitizer (PS) has already proved its worth and has prompted a growing interest in the field of oncology. We have developed a new photosensitizer (PS-FOL/PS2), protected by a recently published patent (WO2019 016397-A1, 24 January 2019). This photosensitizer is associated with an addressing molecule (folic acid) targeting the folate receptor 1 (FOLR1) with a high affinity. Folate binds to FOLR1, in a specific way, expressed in 100% of ADKP or over-expressed in 30% of cases. The first objective of this study is to evaluate the effectiveness of this PS2-PDT in four ADKP cell lines: Capan-1, Capan-2, MiapaCa-2, and Panc-1. For this purpose, we first evaluated the gene and protein expression of FOLR1 on four ADKP cell lines. Subsequently, we evaluated PS2’s efficacy in our cell lines and we assessed the impact of PDT on the secretome of cancer cells and its impact on the immune system. Finally, we evaluate the PDT efficacy on a humanized SCID mouse model of pancreatic cancer. In a very interesting way, we observed a significant increase in the proliferation of activated-human PBMC when cultured with conditioned media of ADKP cancer cells subjected to PDT. Furthermore, to evaluate in vivo the impact of this new PS, we analyzed the tumor growth in a humanized SCID mice model of pancreatic cancer. Four conditions were tested: Untreated, mice (nontreated), mice with PS (PS2), mice subjected to illumination (Light only), and mice subjected to illumination in the presence of PS (PDT). We noticed that the mice subjected to PDT presented a strong decrease in the growth of the tumor over time after illumination. Our investigations have not only suggested that PS2-PDT is an effective therapy in the treatment of PDAC but also that it activates the immune system and could be considered as a real adjuvant for anti-cancer vaccination. Thus, this new study provides new treatment options for patients in a therapeutic impasse and will provide a new arsenal in the fight against PDAC.

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