bims-rehoca Biomed News
on Redox homeostasis in cancer
Issue of 2021–11–21
fourteen papers selected by
Vittoria Raimondi, Veneto Institute of Oncology



  1. Anticancer Agents Med Chem. 2021 Nov 14.
       BACKGROUND: The World Health Organization (WHO) estimated that the number of cancer-related deaths was 9.6 million in 2018 and 2.09 million deaths occurred by lung cancer. The American Institute for Cancer Research (AICR) also observed gender preferences in lung cancer, common in men than women. Since the past decade, nanoparticles have now been widely documented for their anti-cancer properties, which signifies that the development of nanotechnology would be a future diagnosis and treatment strategy for lung cancer.
    OBJECTIVE: The current study aimed to investigate the role of biosynthesized CdS nanoparticles (CdS NPs) in lung cancer cells (A549). Therefore, whether the CdS NP induces lung cancer cell death and the underlying mechanism is yet to be elucidated.
    METHODS: Literature was searched from various archives of biomedical and life science journals. Then, CdS NPs were biosynthesized and characterized by traditional and cutting-edge protocols. The CdS NP-mediated cell death was elucidated following standard protocols.
    RESULTS: CdS NPs induced cytotoxicity towards A549 cells in a dose-dependent manner. However, such a death mechanism does not go through necrosis. Intracellular reactive oxygen species (ROS) accumulation and mitochondrial membrane depolarization demonstrated that cell death is associated with intracellular ROS production. Furthermore, increased sub-G1 population, Bax expression, and decreased Bcl-2 expression revealed that the death was caused by apoptosis.
    CONCLUSION: CdS NPs promote apoptosis-mediated lung cancer cell death through ROS production.
    Keywords:  Apoptosis; cadmium sulfide; cell death; lung cancer; nanoparticles; reactive oxygen
    DOI:  https://doi.org/10.2174/1871520621666211115113226
  2. Adv Healthc Mater. 2021 Nov 17. e2102135
      Reactive oxygen species (ROS) has been employed as a powerful therapeutic agent for eradicating tumor via oxidative stress. As an emerging ROS-involving noninvasive anticancer therapeutic modality, sonodynamic therapy (SDT) with high tissue penetration depth and benign remote spatiotemporal selectivity has been progressively utilized as the distinct alternative for ROS-based tumor treatment. However, the hypoxic tumor microenvironment substantially restricts the sonodynamic effect. In this work, an oxygen self-sufficient hybrid sonosensitizer on the basis of photosynthetic microorganisms cyanobacteria (Cyan) integrated with ultrasmall oxygen-deficient bimetallic oxide Mn1.4 WOx nanosonosensitizers, termed as M@C, is designed and engineered to overcome the critical issue of hypoxia-induced tumor resistance and strengthen the SDT effect. The sustained photosynthetic oxygen production by Cyan under light illumination can promote Mn1.4 WOx nanosonosensitizers to produce more ROS against cancer cells both in vitro and in vivo under ultrasound (US) irradiation. Especially, the sustained oxygen evolution for suppressing the gene expression of hypoxia-inducible factor 1alpha (HIF-1α) further boosts and augments the SDT efficiency. Thus, this work provides the paradigm that the rationally engineered biohybrid microorganism-based multifunctional sonosensitizers can serve as an effective bioplatform for augmenting the therapeutic efficiency of SDT, particularly for the treatment of hypoxic tumors. This article is protected by copyright. All rights reserved.
    Keywords:  ROS; cyanobacteria; hybrid sonosensitizer; sonodynamic therapy; tumor hypoxia microenvironment
    DOI:  https://doi.org/10.1002/adhm.202102135
  3. Am J Transl Res. 2021 ;13(10): 11178-11193
       OBJECTIVE: Redox adaptation plays a critical role in cancer cells' drug tolerance and sensitivity. The antioxidative response is induced by nuclear factor erythroid 2-related factor 2 (Nrf2), which triggers the transcriptional activation of genes related to chemosensitivity, glutathione synthesis, and cell protection. Although Nestin1 is known to regulate cellular redox homeostasis by regulating Nrf2 in lung cancer cells, its regulatory effect on the antioxidative state of bladder cancer (BC) cells remains unclear.
    METHODS: The oxidative stress levels in two cisplatin-treated BC cell lines (T24 and J82) were examined using 2',7'-dichlorofluorescin diacetate staining and real-time quantitative reverse transcription-PCR (RT-qPCR) assays. The cell viability, growth, and apoptosis were determined using CCK-8, colony formation, and flow cytometric assays, respectively. The mRNA and protein levels of Nestin1, Nrf2, and several antioxidant enzymes were quantified using RT-qPCR and western blot assays. A mouse xenograft model was used to determine the effect of Nestin1 on the T24 tumor growth in vivo.
    RESULTS: Cisplatin treatment induced reactive oxygen species (ROS) generation and antioxidative damage in the T24 and J82 cells, reducing their viability and growth and triggering their apoptosis. Moreover, the Nestin1 and Nrf2 protein levels were enhanced in both treated cell lines. Loss- and gain-of-function assays indicated that Nestin1 expression was positively correlated with the Nrf2 protein expression in the BC cells. Nestin1 overexpression reduced the ROS generation, alleviated the redox disorder, promoted cell viability, and reduced apoptosis, but its silencing had the opposite effects. Importantly, Nestin1 overexpression enhanced the chemoresistance of BC cells to cisplatin in vivo, but its knockdown improved the chemosensitivity of the cells and increased their apoptosis.
    CONCLUSION: These results provide a theoretical basis for further targeting the transcription factors, including Nestin1 and Nrf2, in the treatment of BC with cisplatin.
    Keywords:  Bladder cancer; Nestin1; Nrf2; antioxidative response; cisplatin
  4. Phytomedicine. 2021 Oct 19. pii: S0944-7113(21)00350-0. [Epub ahead of print] 153807
       BACKGROUND: Pancreatic cancer is a fatal tumor, which is one of the most common malignant tumors at present. Patients with pancreatic cancer also respond poorly to chemotherapy or radiation therapy and may be accompanied by serious adverse reactions. Therefore, to find an effective way to inhibit the initiation and progression of pancreatic cancer is important to improve the survival and development of patients. Agrimoniin, a polyphenol compounds isolated from Agrimonia pilosa ledeb, has antiviral, antimicrobial, and anticancer activities in vivo and in vitro. However, its molecular mechanism in pancreatic cancer remains to be determined.
    PURPOSE: We aimed to investigate the effect of agrimoniin in pancreatic cancer and its underlying mechanism in vivo and in vitro.
    METHODS: The proliferation was detected by colony formation, cell proliferation and toxicity, and real-time cell analysis techniques. The apoptosis was detected by flow cytometry and Western blot. Flow cytometry was used to measure the level of reactive oxygen species (ROS) and apoptosis. The level of intracellular ROS or mitochondrial membrane potential was measured with a DCFH-DA or JC-1 probe. Cell metabolism assays were analyzed and evaluated by using Agilent Seahorse Bioscience XF96 Extracellular Flux Analyzer. The target proteins were analyzed by Western blot. Subcutaneous cancer models in nude mice were established to evaluate the anticancer effects in vivo.
    RESULTS: Agrimoniin inhibited cell growth and promoted cell apoptosis by regulating cell metabolism in pancreatic cancer cells. Agrimoniin increased the ROS level in pancreatic cancer cells by suppressing Nrf2-dependent ROS scavenging system and disrupting normal mitochondrial membrane potential. We also found that agrimoniin significantly disrupted mitochondrial function and reduced the protein expression of mTOR/HIF-1α pathway and subsequently decreased oxygen consumption rate and extracellular acidification rate. Eventually, agrimoniin affected intracellular energy metabolism and induced apoptosis of pancreatic cancer cells.
    CONCLUSIONS: These findings reveal the novel function of agrimoniin in promoting apoptosis of pancreatic cancer cells through mediating energy metabolism dysfunction. Altogether, the potential new targets and their synergies discovered in this research are of great significance for cancer treatment and drug development.
    Keywords:  Agrimoniin; Energy metabolism; Pancreatic cancer; ROS
    DOI:  https://doi.org/10.1016/j.phymed.2021.153807
  5. Oxid Med Cell Longev. 2021 ;2021 6816214
      Metabolic energy production naturally generates unwanted products such as reactive oxygen species (ROS), causing oxidative damage. Oxidative damage has been linked to several pathologies, including diabetes, premature aging, neurodegenerative diseases, and cancer. ROS were therefore originally anticipated as an imperative evil, a product of an imperfect system. More recently, however, the role of ROS in signaling and tumor treatment is increasingly acknowledged. This review addresses the main types, sources, and pathways of ROS in melanoma by linking their pleiotropic roles in antioxidant and oxidant regulation, hypoxia, metabolism, and cell death. In addition, the implications of ROS in various physical therapy modalities targeting melanoma, such as radiotherapy, electrochemotherapy, hyperthermia, photodynamic therapy, and medical gas plasma, are also discussed. By including ROS in the main picture of melanoma skin cancer and as an integral part of cancer therapies, a greater understanding of melanoma cell biology is presented, which ultimately may elucidate additional clues on targeting therapy resistance of this most deadly form of skin cancer.
    DOI:  https://doi.org/10.1155/2021/6816214
  6. Biomed Pharmacother. 2021 Dec;pii: S0753-3322(21)01142-2. [Epub ahead of print]144 112358
      Effective treatment of lung cancer remains a significant clinical challenge due to its multidrug resistance and side effects of the current treatment options. The high mortality associated with this malignancy indicates the need for new therapeutic interventions with fewer side effects. Natural compounds offer various benefits such as easy access, minimal side effects, and multi-molecular targets and thus, can prove useful in treating lung cancer. Sanguinarine (SNG), a natural compound, possesses favorable therapeutic potential against a variety of cancers. Here, we examined the underlying molecular mechanisms of SNG in Non-Small Cell Lung Cancer (NSCLC) cells. SNG suppressed cell growth and induced apoptosis via downregulation of the constitutively active JAK/STAT pathway in all the NSCLC cell lines. siRNA silencing of STAT3 in NSCLC cells further confirmed the involvement of the JAK/STAT signaling cascade. SNG treatment increased Bax/Bcl-2 ratio, which contributed to a leaky mitochondrial membrane leading to cytochrome c release accompanied by caspase activation. In addition, we established the antitumor effects of SNG through reactive oxygen species (ROS) production, as inhibiting ROS production prevented the apoptosis-inducing potential of SNG. In vivo xenograft tumor model further validated our in vitro findings. Overall, our study investigated the molecular mechanisms by which SNG induces apoptosis in NSCLC, providing avenues for developing novel natural compound-based cancer therapies.
    Keywords:  Alkaloids; Antioxidants; Antiproliferative; Apoptosis; Cancer stem cells; ROS; STAT3; Sanguinarine
    DOI:  https://doi.org/10.1016/j.biopha.2021.112358
  7. Front Pharmacol. 2021 ;12 729367
      There is an urgent need for novel agents for colorectal cancer (CRC) due to the increasing number of cases and drug-resistance related to current treatments. In this study, we aim to uncover the potential of chaetocin, a natural product, as a chemotherapeutic for CRC treatment. We showed that, regardless of 5-FU-resistance, chaetocin induced proliferation inhibition by causing G2/M phase arrest and caspase-dependent apoptosis in CRC cells. Mechanically, our results indicated that chaetocin could induce reactive oxygen species (ROS) accumulation and activate c-Jun N-terminal kinase (JNK)/c-Jun pathway in CRC cells. This was confirmed by which the JNK inhibitor SP600125 partially rescued CRC cells from chaetocin induced apoptosis and the ROS scavenger N-acetyl-L-cysteine (NAC) reversed both the chaetocin induced apoptosis and the JNK/c-Jun pathway activation. Additionally, this study indicated that chaetocin could down-regulate the expression of CD47 at both mRNA and protein levels, and enhance macrophages phagocytosis of CRC cells. Chaetocin also inhibited tumor growth in CRC xenograft models. In all, our study reveals that chaetocin induces CRC cell apoptosis, irrelevant to 5-FU sensitivity, by causing ROS accumulation and activating JNK/c-Jun, and enhances macrophages phagocytosis, which suggests chaetocin as a candidate for CRC chemotherapy.
    Keywords:  CD47; JNK/c-Jun pathway; ROS; apoptosis; chaetocin; colorectal cancer
    DOI:  https://doi.org/10.3389/fphar.2021.729367
  8. Oxid Med Cell Longev. 2021 ;2021 1341604
      Mitochondria are the main powerhouse of the cell, generating ATP through the tricarboxylic acid cycle (TCA) and oxidative phosphorylation (OXPHOS), which drives myriad cellular processes. In addition to their role in maintaining bioenergetic homeostasis, changes in mitochondrial metabolism, permeability, and morphology are critical in cell fate decisions and determination. Notably, mitochondrial respiration coupled with the passage of electrons through the electron transport chain (ETC) set up a potential source of reactive oxygen species (ROS). While low to moderate increase in intracellular ROS serves as secondary messenger, an overwhelming increase as a result of either increased production and/or deficient antioxidant defenses is detrimental to biomolecules, cells, and tissues. Since ROS and mitochondria both regulate cell fate, attention has been drawn to their involvement in the various processes of carcinogenesis. To that end, the link between a prooxidant milieu and cell survival and proliferation as well as a switch to mitochondrial OXPHOS associated with recalcitrant cancers provide testimony for the remarkable metabolic plasticity as an important hallmark of cancers. In this review, the regulation of cell redox status by mitochondrial metabolism and its implications for cancer cell fate will be discussed followed by the significance of mitochondria-targeted therapies for cancer.
    DOI:  https://doi.org/10.1155/2021/1341604
  9. Mater Today Bio. 2021 Sep;12 100154
      Ferroptosis has received ever-increasing attention due to its unparalleled mechanism in eliminating resistant tumor cells. Nevertheless, the accumulation of toxic lipid peroxides (LPOs) at the tumor site is limited by the level of lipid oxidation. Herein, by leveraging versatile sodium alginate (ALG) hydrogel, a localized ferroptosis trigger consisting of gambogic acid (GA), 2,2'-azobis [2-(2-imidazolin-2-yl) propane] dihydrochloride (AIPH), and Ink (a photothermal agent), was constructed via simple intratumor injection. Upon 1064 ​nm laser irradiation, the stored AIPH rapidly decomposed into alkyl radicals (R•), which aggravated LPOs in tumor cells. Meanwhile, GA could inhibit heat shock protein 90 (HSP90) to reduce the heat resistance of tumor cells, and forcefully consume glutathione (GSH) to weaken the antioxidant capacity of cells. Systematic in vitro and in vivo experiments have demonstrated that synchronous consumption of GSH and increased reactive oxygen species (ROS) facilitated reduced expression of glutathione peroxidase 4 (GPX4), which further contributed to disruption of intracellular redox homeostasis and ultimately boosted ferroptosis. This all-in-one strategy has a highly effective tumor suppression effect by depleting and generating fatal active compounds at tumor sites, which would pave a new route for the controllable, accurate, and coordinated tumor treatments.
    Keywords:  ABTS, 2,2-Azobis (3-ethylbenzothiazoline-6-sulfonic acid); AIPH, 2,2′-azobis [2-(2-imidazolin-2-yl) propane] dihydrochloride; ALG, sodium alginate; Alkyl radicals; CCK–8, Cell counting kit-8; CLSM, confocal laser scanning microscope; DAPI, 4′,6-diamidino-2-phenylindole; DCFH-DA, 2,7-dichlorofluorescin diacetate; DFO, deferoxamine mesylate; DLS, dynamic light scattering; DMEM, Dulbecco's Modified Eagle's Medium; DTNB, 5,5′-Dithiobis-(2-nitrobenzoic acid); FBS, fetal bovine serum; Fer-1, Ferrostatin -1; Ferroptosis; GA, gambogic acid; GPX4, glutathione peroxidase 4; GSH, glutathione; Glutathione peroxidase; HE, hematoxylin eosin; HSP90, heat shock protein 90; Hydrogel; IR, inhibitory rate; LPO, lipid peroxides; NPs, nanodrugs; PTT, photothermal therapy; ROS, reactive oxygen species; Redox homeostasis; R•, alkyl radicals
    DOI:  https://doi.org/10.1016/j.mtbio.2021.100154
  10. Hum Cell. 2021 Nov 20.
      Reactive Oxygen Species are chemically unstable molecules generated during aerobic respiration, especially in the electron transport chain. ROS are involved in various biological functions; any imbalance in their standard level results in severe damage, for instance, oxidative damage, inflammation in a cellular system, and cancer. Oxidative damage activates signaling pathways, which result in cell proliferation, oncogenesis, and metastasis. Since the last few decades, mesenchymal stromal cells have been explored as therapeutic agents against various pathologies, such as cardiovascular diseases, acute and chronic kidney disease, neurodegenerative diseases, macular degeneration, and biliary diseases. Recently, the research community has begun developing several anti-tumor drugs, but these therapeutic drugs are ineffective. In this present review, we would like to emphasize MSCs-based targeted therapy against pathologies induced by ROS as cells possess regenerative potential, immunomodulation, and migratory capacity. We have also focused on how MSCs can be used as next-generation drugs with no side effects.
    Keywords:  Cancer; Electron transport chain; Mesenchymal stromal cells; Metastasis; Oxidative stress; Reactive oxygen species
    DOI:  https://doi.org/10.1007/s13577-021-00646-5
  11. EMBO Rep. 2021 Nov 15. e53140
      Oxaliplatin (L-OHP) is a standard treatment for colorectal cancer (CRC), but chemoresistance is a considerable challenge. L-OHP shows dose-dependent toxicity, and potential approaches that sensitize cancer cells to L-OHP could reduce the dosage. With the development of translatomics, it was found that some lncRNAs encode short peptides. Here, we use ribosome footprint profiling combined with lncRNA-Seq to screen 12 lncRNAs with coding potential, of which lnc-AP encodes the short peptide pep-AP, for their role in L-OHP resistance. Co-IP and LC-MS/MS data show that the TALDO1 protein interacts with pep-AP and that pep-AP suppresses the expression of TALDO1. The pep-AP/TALDO1 pathway attenuates the pentose phosphate pathway (PPP), reducing NADPH/NADP+ and glutathione (GSH) levels and causing ROS accumulation and apoptosis, which sensitizes CRC cells to L-OHP in vitro and in vivo. pep-AP thus might become a potential anticancer peptide for future treatments of L-OHP-resistant CRC.
    Keywords:  ROS; lncRNA; oxaliplatin resistance; pentose phosphate pathway; peptide
    DOI:  https://doi.org/10.15252/embr.202153140
  12. Front Oncol. 2021 ;11 743006
      Cell death is essential for the normal metabolism of human organisms. Ferroptosis is a unique regulated cell death (RCD) mode characterized by excess accumulation of iron-dependent lipid peroxide and reactive oxygen species (ROS) compared with other well-known programmed cell death modes. It has been currently recognized that ferroptosis plays a rather important role in the occurrence, development, and treatment of traumatic brain injury, stroke, acute kidney injury, liver damage, ischemia-reperfusion injury, tumor, etc. Of note, ferroptosis may be explained by the expression of various molecules and signaling components, among which iron, lipid, and amino acid metabolism are the key regulatory mechanisms of ferroptosis. Meanwhile, tumor cells of hematological malignancies, such as leukemia, lymphoma, and multiple myeloma (MM), are identified to be sensitive to ferroptosis. Targeting potential regulatory factors in the ferroptosis pathway may promote or inhibit the disease progression of these malignancies. In this review, a systematic summary was conducted on the key molecular mechanisms of ferroptosis and the current potential relationships of ferroptosis with leukemia, lymphoma, and MM. It is expected to provide novel potential therapeutic approaches and targets for hematological malignancies.
    Keywords:  GSH; ferroptosis; iron metabolism; leukemia; lymphoma; reactive oxygen species; regulated cell death
    DOI:  https://doi.org/10.3389/fonc.2021.743006
  13. Front Pharmacol. 2021 ;12 775506
      Erianin, a natural product derived from Dendrobium chrysotoxum Lindl, has been proved to play antitumor activity in various cancers. However, the effects and molecular mechanisms of erianin in bladder cancer cells remain unexplored. In this study, we found that erianin triggered cell death and cell cycle arrest in bladder cancer cells. Then we demonstrated that erianin could promote the accumulation of lethal lipid-based reactive oxygen species (ROS) and the depletion of glutathione (GSH), suggesting the induction of ferroptosis. In the further study, the ferroptosis inhibitor deferoxamine (DFO), N-Acetylcysteine (NAC) and GSH but not necrostatin-1, CQ or Z-VAD-FMK rescued erianin-caused cell death, showing ferroptosis played a major role in erianin-caused cell death. In vivo, we also showed that erianin suppressed the tumor growth by inducing ferroptosis. Mechanistically, we demonstrated that nuclear factor E2-related factor 2 (NRF2) inactivation was a key determinant of ferroptosis caused by erianin. In bladder cancer cells, the compound tert-butylhydro-quinone (TBHQ), an activator of NRF2, suppressed erianin-induced ferroptosis. Whereas, NRF2 inhibition used shRNA augmented the ferroptosis response induced by erianin treatment. In conclusion, our data provide the first evidence that erianin can initiate ferroptosis-like cell death and lipid peroxidation in bladder cancer, which will hopefully become a promising anticancer compound for the treatment of bladder cancer.
    Keywords:  Erianin; bladder cancer; ferroptosis; natural product; nuclear factor E2-related factor 2
    DOI:  https://doi.org/10.3389/fphar.2021.775506
  14. Oxid Med Cell Longev. 2021 ;2021 6485871
      Hepatocellular carcinoma (HCC) is an aggressive malignant tumor with a poor prognosis. Reactive oxygen species (ROS) play an important role in tumors; however, the role of ROS-related genes is still unclear in HCC. Therefore, we analyzed the role of ROS-related genes in HCC via bioinformatics methods. Firstly, a prognosis model was constructed using LASSO Cox regression and multivariate analyses. We also investigated the potential function of the ROS-related genes and the correlation with immune infiltration, tumor stemness, and drug sensitivity. ICGC database was used for validation. Secondly, we further analyzed the role of 11 ROS-related genes in HCC. As a member of ROS gene family, the role of STK25 has remained unclear in HCC. We explored the biological function of STK25 using in vitro experiments. The present study was the first to construct a ROS-related prognostic model in HCC. The correlation of ROS-related genes with immune infiltration, tumor stemness, and drug sensitivity was dissected. Furthermore, we demonstrated that STK25 knockdown could increase the proliferation, migration, and invasion capacity of HCC cells.
    DOI:  https://doi.org/10.1155/2021/6485871