scholarly journals Mitochondria-driven elimination of cancer and senescent cells

2019 ◽  
Vol 400 (2) ◽  
pp. 141-148 ◽  
Author(s):  
Sona Hubackova ◽  
Silvia Magalhaes Novais ◽  
Eliska Davidova ◽  
Jiri Neuzil ◽  
Jakub Rohlena

AbstractMitochondria and oxidative phosphorylation (OXPHOS) are emerging as intriguing targets for the efficient elimination of cancer cells. The specificity of this approach is aided by the capacity of non-proliferating non-cancerous cells to withstand oxidative insult induced by OXPHOS inhibition. Recently we discovered that mitochondrial targeting can also be employed to eliminate senescent cells, where it breaks the interplay between OXPHOS and ATP transporters that appear important for the maintenance of mitochondrial morphology and viability in the senescent setting. Hence, mitochondria/OXPHOS directed pharmacological interventions show promise in several clinically-relevant scenarios that call for selective removal of cancer and senescent cells.

2020 ◽  
Vol 21 (3) ◽  
pp. 178-185 ◽  
Author(s):  
Mohammad Amjad Kamal ◽  
Maryam Hassan Al-Zahrani ◽  
Salman Hasan Khan ◽  
Mateen Hasan Khan ◽  
Hani Awad Al-Subhi ◽  
...  

Cancer cells are altered with cell cycle genes or they are mutated, leading to a high rate of proliferation compared to normal cells. Alteration in these genes leads to mitosis dysregulation and becomes the basis of tumor progression and resistance to many drugs. The drugs which act on the cell cycle fail to arrest the process, making cancer cell non-responsive to apoptosis or cell death. Vinca alkaloids and taxanes fall in this category and are referred to as antimitotic agents. Microtubule proteins play an important role in mitosis during cell division as a target site for vinca alkaloids and taxanes. These proteins are dynamic in nature and are composed of α-β-tubulin heterodimers. β-tubulin specially βΙΙΙ isotype is generally altered in expression within cancerous cells. Initially, these drugs were very effective in the treatment of cancer but failed to show their desired action after initial chemotherapy. The present review highlights some of the important targets and their mechanism of resistance offered by cancer cells with new promising drugs from natural sources that can lead to the development of a new approach to chemotherapy.


Genes ◽  
2021 ◽  
Vol 12 (4) ◽  
pp. 466
Author(s):  
Chen Chen ◽  
Samuel Haddox ◽  
Yue Tang ◽  
Fujun Qin ◽  
Hui Li

Gene fusions and their products (RNA and protein) have been traditionally recognized as unique features of cancer cells and are used as ideal biomarkers and drug targets for multiple cancer types. However, recent studies have demonstrated that chimeric RNAs generated by intergenic alternative splicing can also be found in normal cells and tissues. In this study, we aim to identify chimeric RNAs in different non-neoplastic cell lines and investigate the landscape and expression of these novel candidate chimeric RNAs. To do so, we used HEK-293T, HUVEC, and LO2 cell lines as models, performed paired-end RNA sequencing, and conducted analyses for chimeric RNA profiles. Several filtering criteria were applied, and the landscape of chimeric RNAs was characterized at multiple levels and from various angles. Further, we experimentally validated 17 chimeric RNAs from different classifications. Finally, we examined a number of validated chimeric RNAs in different cancer and non-cancer cells, including blood from healthy donors, and demonstrated their ubiquitous expression pattern.


Author(s):  
Edward J. Cochrane ◽  
James Hulit ◽  
Franz P. Lagasse ◽  
Tanguy Lechertier ◽  
Brett Stevenson ◽  
...  

2020 ◽  
Vol 22 (Supplement_2) ◽  
pp. ii225-ii226
Author(s):  
Vahan Martirosian ◽  
Krutika Deshpande ◽  
Hao Zhou ◽  
Keyue Shen ◽  
Vazgen Stepanosyan ◽  
...  

Abstract Medulloblastoma (MB) is a malignant pediatric brain tumor. Studies have shown heterogeneous cells amongst the tumor bulk which mirror normal neural cells in various neurodevelopmental stages. To discern exploited mechanisms promoting MB leptomeningeal disease, we drew conclusions from developmental neurobiology. In normal differentiation, the metabolic phenotype in proliferating neural progenitor cells evolves from a glycolysis-dependent to an oxidative phosphorylation-reliant energetic profile in quiescent differentiated neurons. Cancer cells mirror this evolution, which also grants them the capability to utilize alternative nutrients in the microenvironment as an energy source. Considering metastatic cells are typically in a dormant state and primarily utilize oxidative phosphorylation, we hypothesized metastatic MB cells emulate a quiescent neuron-like cellular profile to survive in the cerebrospinal fluid and form leptomeningeal metastases. To examine this, we query the expression of GABA catabolic enzyme GABA transaminase (ABAT) in MB. GABA is found in the cerebellar and leptomeningeal microenvironments, and is utilized by metastatic cancer cells in the CNS as an energy source. We correlate an increase in ABAT expression with neurodevelopment and show heterogeneous expression of this protein in primary MB tumors. MB cells with increased expression of ABAT were slower-dividing, expressed a genetic and metabolic phenotype reminiscent of quiescent neuron-like cells, and had increased capability to metabolize GABA. Conversely, lower expression of ABAT was associated with an increased proliferation rate and correlated with a progenitor-like cellular profile. Transplantation of MB cells into the leptomeningeal compartment decreased proliferative capacity and enhanced ABAT expression. Xenograft models showed MB cells with ABAT knockdown had increased growth in the cerebellar microenvironment. Conversely, MB cells with ABAT overexpression transplanted into the cerebrospinal fluid formed leptomeningeal metastases whereas ABAT knockdown cells could not. These results suggest ABAT expression in MB cells can be modulated by the tumor microenvironment and is required to form leptomeningeal metastases.


2021 ◽  
Vol 19 (1) ◽  
Author(s):  
Weiwei Zou ◽  
Qixin Chen ◽  
Jesse Slone ◽  
Li Yang ◽  
Xiaoting Lou ◽  
...  

AbstractSLC25A46 mutations have been found to lead to mitochondrial hyper-fusion and reduced mitochondrial respiratory function, which results in optic atrophy, cerebellar atrophy, and other clinical symptoms of mitochondrial disease. However, it is generally believed that mitochondrial fusion is attributable to increased mitochondrial oxidative phosphorylation (OXPHOS), which is inconsistent with the decreased OXPHOS of highly-fused mitochondria observed in previous studies. In this paper, we have used the live-cell nanoscope to observe and quantify the structure of mitochondrial cristae, and the behavior of mitochondria and lysosomes in patient-derived SLC25A46 mutant fibroblasts. The results show that the cristae have been markedly damaged in the mutant fibroblasts, but there is no corresponding increase in mitophagy. This study suggests that severely damaged mitochondrial cristae might be the predominant cause of reduced OXPHOS in SLC25A46 mutant fibroblasts. This study demonstrates the utility of nanoscope-based imaging for realizing the sub-mitochondrial morphology, mitophagy and mitochondrial dynamics in living cells, which may be particularly valuable for the quick evaluation of pathogenesis of mitochondrial morphological abnormalities.


Circulation ◽  
2020 ◽  
Vol 142 (Suppl_3) ◽  
Author(s):  
Xuan Li ◽  
Jussara M do Carmo ◽  
Zhen Wang ◽  
Alexandre A da Sivla ◽  
Alan J Mouton ◽  
...  

Introduction: The underlying mechanisms by which empagliflozin (EMPA) and other sodium glucose co-transporter 2 (SGLT2) inhibitors attenuate heart failure (HF) are still poorly understood. However, this protection does not appear to be fully explained by their antihyperglycemic or diuretic effects. Hypothesis: EMPA attenuates HF by direct effects on the heart to improve its metabolism and function. Methods: C57BL/6J mice (4-6 months) were subjected to transverse aortic constriction (TAC) or sham surgeries. Two weeks after TAC, EMPA (10 mg/kg/day) or vehicle was administered daily for 4 additional weeks. Cardiac function was assessed by echocardiography and cardiac substrate metabolism measured in isolated perfused hearts. Transmission electron microscopy was used to evaluate mitochondrial morphology and molecular docking analysis to predict potential cardiac targets of EMPA. Results: EMPA increased survival and attenuated adverse left ventricle remodeling and cardiac fibrosis after TAC. EMPA also attenuated left ventricular systolic dysfunction (ejection fraction 51.6 vs. 40.2% p<0.05; fraction shortening 28.8 vs 18.4% p<0.05). EMPA rescued impaired glucose and fatty acid oxidation in failing hearts, while reducing glycolysis. Molecular docking analysis and isolated perfused heart experiments indicated that EMPA can directly bind glucose transporters in the heart to reduce glycolysis, and enhance AMP-activated protein kinase. EMPA treatment enhanced mitochondrial biogenesis, restored mitochondria cristae integrity, increased expression of endogenous antioxidants, and reduced cellular apoptosis caused by leakage of cytochrome C from mitochondria into the cytosol. These beneficial cardiac effects of EMPA occurred despite no alterations in fasting blood glucose, body weight, or daily urine volume. Conclusions. Our study demonstrated that EMPA may directly bind glucose transporters and reduce excessive glycolysis in failing hearts. EMPA enhanced mitochondrial biogenesis, improved mitochondrial oxidative phosphorylation, and reduced mitochondria-mediated apoptosis, thereby attenuating cardiac dysfunction and progression of HF.


2019 ◽  
Author(s):  
Dongqing Zheng ◽  
Jonathan H. Sussman ◽  
Matthew P. Jeon ◽  
Sydney T. Parrish ◽  
Alireza Delfarah ◽  
...  

ABSTRACTOncogenes can generate metabolic vulnerabilities in cancer cells. Here, we tested how AKT and MYC affect the ability of cells to shift between respiration and glycolysis. Using immortalized mammary epithelial cells, we discovered that constitutively active AKT but not MYC induced cell death in galactose culture, where cells must rely on oxidative phosphorylation for energy generation. However, the negative effects of AKT were short-lived, and AKT-expressing cells recommenced growth after ~15 days in galactose. To identify the mechanisms regulating AKT-mediated cell death, we used metabolomics and found that AKT cells dying in galactose upregulated glutathione metabolism. Next, using proteomics, we discovered that AKT-expressing cells dying in galactose upregulated nonsense-mediated mRNA decay, a marker of sensitivity to oxidative stress. We therefore measured levels of reactive oxygen species (ROS) and discovered that galactose induced ROS in cells expressing AKT but not MYC. Additionally, ROS were required for the galactose-induced death of AKT-expressing cells. We then tested whether these findings could be replicated in breast cancer cell lines with constitutively active AKT signaling. Indeed, we found that galactose induced rapid cell death in breast cancer cell lines and that ROS were required for galactose-induced cell death. Together, our results demonstrate that AKT but not MYC induces a metabolic vulnerability in cancer cells, namely the restricted flexibility to use oxidative phosphorylation.ImplicationsThe discovery that AKT but not MYC restricts the ability to utilize oxidative phosphorylation highlights that therapeutics targeting tumor metabolism must be tailored to the individual genetic profile of tumors.


2021 ◽  
Vol 9 ◽  
Author(s):  
Sarit Larisch

Every cell in our body contains a “self-destruction” program. This cell death is a critical process allowing replacement of damaged cells with healthy ones to prevent wide range of diseases. When the cell’s death mechanism gets “stuck” and is not activated, cancer can result. In healthy cells there is a balanced system of proteins, some of which activate the normal death mechanism, and some of which inhibit this process. This is like the system of gas and brakes in a car. Researchers have found that cancer cells lack a protein, called ARTS, which is crucial for activating the cells’ death mechanism. The lack of ARTS causes cancer cells to escape death and become “immortal.” Small ARTS-like molecules have been discovered that can penetrate cancerous cells and reactivate the cell death program, effectively making the cancer cells “commit suicide.” We envision that these ARTS-like molecules will provide novel therapy for cancer.


2021 ◽  
Vol 8 ◽  
Author(s):  
Rhys Richard Mould ◽  
Stanley W. Botchway ◽  
James R. C. Parkinson ◽  
Elizabeth Louise Thomas ◽  
Geoffrey W Guy ◽  
...  

The cannabinoid, cannabidiol (CBD), is part of the plant's natural defense system that when given to animals has many useful medicinal properties, including activity against cancer cells, modulation of the immune system, and efficacy in epilepsy. Although there is no consensus on its precise mode of action as it affects many cellular targets, CBD does appear to influence mitochondrial function. This would suggest that there is a cross-kingdom ability to modulate stress resistance systems that enhance homeostasis. As NAD(P)H autofluorescence can be used as both a metabolic sensor and mitochondrial imaging modality, we assessed the potential of this technique to study the in vitro effects of CBD using 2-photon excitation and fluorescence lifetime imaging microscopy (2P-FLIM) of NAD(P)H against more traditional markers of mitochondrial morphology and cellular stress in MCF7 breast cancer cells. 2P-FLIM analysis revealed that the addition of CBD induced a dose-dependent decrease in bound NAD(P)H, with 20 µM treatments significantly decreased the contribution of bound NAD(P)H by 14.6% relative to the control (p &lt; 0.001). CBD also increased mitochondrial concentrations of reactive oxygen species (ROS) (160 ± 53 vs. 97.6 ± 4.8%, 20 µM CBD vs. control, respectively, p &lt; 0.001) and Ca2+ (187 ± 78 vs. 105 ± 10%, 20 µM CBD vs. the control, respectively, p &lt; 0.001); this was associated with a significantly decreased mitochondrial branch length and increased fission. These are all suggestive of mitochondrial stress. Our results support the use of NAD(P)H autofluorescence as an investigative tool and provide further evidence that CBD can modulate mitochondrial function and morphology in a dose-dependent manner, with clear evidence of it inducing oxidative stress at higher concentrations. This continues to support emerging data in the literature and may provide further insight into its overall mode of action, not only in cancer, but potentially its function in the plant and why it can act as a medicine.


Open Biology ◽  
2018 ◽  
Vol 8 (6) ◽  
pp. 170272 ◽  
Author(s):  
Rhys Grant ◽  
Ahmed Abdelbaki ◽  
Alessia Bertoldi ◽  
Maria P. Gavilan ◽  
Jörg Mansfeld ◽  
...  

Aurora A kinase (AURKA) is a major regulator of mitosis and an important driver of cancer progression. The roles of AURKA outside of mitosis, and how these might contribute to cancer progression, are not well understood. Here, we show that a fraction of cytoplasmic AURKA is associated with mitochondria, co-fractionating in cell extracts and interacting with mitochondrial proteins by reciprocal co-immunoprecipitation. We have also found that the dynamics of the mitochondrial network are sensitive to AURKA inhibition, depletion or overexpression. This can account for the different mitochondrial morphologies observed in RPE-1 and U2OS cell lines, which show very different levels of expression of AURKA. We identify the mitochondrial fraction of AURKA as influencing mitochondrial morphology, because an N-terminally truncated version of the kinase that does not localize to mitochondria does not affect the mitochondrial network. We identify a cryptic mitochondrial targeting sequence in the AURKA N-terminus and discuss how alternative conformations of the protein may influence its cytoplasmic fate.


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