bims-nurfca Biomed News
on NRF2 and Cancer
Issue of 2024–08–18
seven papers selected by
Caner Geyik, Istinye University



  1. Bull Exp Biol Med. 2024 Aug 14.
      We studied the expression of Nrf2 transcription factor and antioxidant system proteins in drug-resistant murine leukemia strains P388 in vivo, as well as the redox status of cells under conditions of induced oxidative stress. Immunoblotting and real-time PCR showed that the cyclophosphamide-resistant strain P388 (P388/CP) exhibits Nrf2-mediated drug resistance. Cells of the P388/CP strain are characterized by high expression of Nrf2, which leads to a significant increase in the expression of ARE genes and antioxidant system proteins, as well as to the effective maintenance of redox homeostasis under conditions of induced oxidative stress. Taking into account the important role of Nrf2 overexpression in reducing the effectiveness of chemotherapy in patients with different leukemias, the P388/CP strain can be of great interest as a model in the development of new drugs for the treatment of malignant neoplasms.
    Keywords:  antioxidant system; leukemia P388; reactive oxygen species; resistance; transcription factor Nrf2
    DOI:  https://doi.org/10.1007/s10517-024-06181-1
  2. Onco Targets Ther. 2024 ;17 605-627
      Photodynamic therapy (PDT) is a groundbreaking approach involving the induction of cytotoxic reactive oxygen species (ROS) within tumors through visible light activation of photosensitizers (PS) in the presence of molecular oxygen. This innovative therapy has demonstrated success in treating various cancers. While PDT proves highly effective in most solid tumors, there are indications that certain cancers exhibit resistance, and some initially responsive cancers may develop intrinsic or acquired resistance to PDT. The molecular mechanisms underlying this resistance are not fully understood. Recent evidence suggests that, akin to other traditional cancer treatments, the activation of survival pathways, such as the KEAP1/Nrf2 signaling pathway, is emerging as an important mechanism of post-PDT resistance in many cancers. This article explores the dual role of Nrf2, highlighting evidence linking aberrant Nrf2 expression to treatment resistance across a range of cancers. Additionally, it delves into the specific role of Nrf2 in the context of photodynamic therapy for cancers, emphasizing evidence that suggests Nrf2-mediated upregulation of antioxidant responses and induction of drug efflux transporters are potential mechanisms of resistance to PDT in diverse cancer types. Therefore, understanding the specific role(s) of Nrf2 in PDT resistance may pave the way for the development of more effective cancer treatments using PDT.
    Keywords:  Nrf2; antioxidant response; oxidative stress; photodynamic therapy; tumor resistance
    DOI:  https://doi.org/10.2147/OTT.S457749
  3. Redox Biol. 2024 Aug 08. pii: S2213-2317(24)00283-0. [Epub ahead of print]75 103305
      Extensive efforts have been conducted in the search for new targetable drivers of lung squamous cell carcinoma (LUSC); to date, however, candidates remain mostly unsuccessful. One of the oncogenic pathways frequently found to be active in LUSC is NFE2L2 (NRF2 transcription factor), the levels of which are regulated by KEAP1. Mutations in NFE2L2 or KEAP1 trigger NRF2 activation, an essential protector against reactive oxygen species (ROS). We hypothesized that the frequency of NRF2 activation in LUSC (∼35 %) may reflect a sensitivity of LUSC to ROS. Results from this study reveal that whereas tumors containing active forms of NRF2 were protected, ROS induction in wild-type NFE2L2/KEAP1 LUSC cells triggered ferroptosis. The mechanism of ROS action in normal-NRF2 LUSC cells involved transient NRF2 activation, miR-126-3p/miR-126-5p upregulation, and reduction of p85β and SETD5 levels. SETD5 levels reduction triggered pentose pathway gene levels increase to toxic values. Simultaneous depletion of p85βPI3K and SETD5 triggered LUSC cell death, while p85βPI3K and SETD5 overexpression rescued survival of ROS-treated normal-NRF2 LUSC cells. This shows that the cascade involving NRF2 > miR-126-3p, miR-126-5p > p85βPI3K and SETD5 is responsible for ROS-induced cell death in normal-NRF2 LUSC. Transient ROS-induced cell death is shown in 3D spheroids, patient-derived organoids, and in xenografts of wild-type NFE2L2/KEAP1 LUSC cells, supporting the potential of acute local ROS induction as a therapeutic strategy for LUSC patients with normal-NRF2.
    Keywords:  LUSC treatment; MicroRNA126; PI3K; SETD5; Transient ROS inducers; p85β(PI3K)
    DOI:  https://doi.org/10.1016/j.redox.2024.103305
  4. Cell Death Dis. 2024 Aug 09. 15(8): 583
      In advanced hepatocellular carcinoma (HCC), RNA helicase DDX5 regulates the Wnt/β-catenin-ferroptosis axis, influencing the efficacy of the multi-tyrosine kinase inhibitor (mTKI) sorafenib. DDX5 inhibits Wnt/β-catenin signaling, preventing sorafenib-induced ferroptosis escape. Sorafenib/mTKIs reduce DDX5 expression, correlating with poor patient survival post-sorafenib treatment. Notably, DDX5-knockout in HCC cells activates Wnt/β-catenin signaling persistently. Herein, we investigate the mechanistic impact of Wnt/β-catenin activation resulting from DDX5 downregulation in the progression and treatment of HCC. RNAseq analyses identified shared genes repressed by DDX5 and upregulated by sorafenib, including Wnt signaling genes, NF-κB-inducing kinase (NIK) essential for non-canonical NF-κB (p52/RelB) activation, and cytoprotective transcription factor NRF2. We demonstrate, Wnt/β-catenin activation induced NIK transcription, leading to non-canonical NF-κB activation, which subsequently mediated NRF2 transcription. Additionally, DDX5 deficiency extended NRF2 protein half-life by inactivating KEAP1 through p62/SQSTM1 stabilization. In a preclinical HCC mouse model, NRF2 knockdown or DDX5 overexpression restricted tumor growth upon sorafenib treatment, via induction of ferroptosis. Importantly, DDX5-knockout HCC cells exhibited elevated expression of Wnt signaling genes, NIK, p52/RelB, and NRF2-regulated genes, regardless of sorafenib treatment. Transcriptomic analyses of HCCs from TCGA and the Stelic Animal Model (STAM) of non-alcoholic steatohepatitis revealed elevated expression of these interconnected pathways in the context of DDX5 downregulation. In conclusion, DDX5 deficiency triggers Wnt/β-catenin signaling, promoting p52/RelB and NRF2 activation, thereby enabling ferroptosis evasion upon sorafenib treatment. Similarly, independent of sorafenib, DDX5 deficiency in liver tumors enhances activation and gene expression of these interconnected pathways, underscoring the clinical relevance of DDX5 deficiency in HCC progression and therapeutic response.
    DOI:  https://doi.org/10.1038/s41419-024-06977-z
  5. Mol Carcinog. 2024 Aug 13.
      Sirtuin 1 (SIRT1), a member of histone deacetylase III family, plays a pivotal role in mediating chemoresistance in several cancers, including breast cancer. However, the molecular mechanism by which the deregulated SIRT1 promotes doxorubicin (Dox) resistance is still elusive. Here, we showed that the cell proliferation rates and invasive properties of MDA-MB-231 breast cancer cells were increased from low- to high-Dox-resistant cells. In agreement, severe combined immunodeficiency disease (SCID) mice bearing labeled MDA-MB-231high Dox-Res cells showed significantly higher tumor growth, angiogenesis, and metastatic ability than parental MDA-MB-231 cells. Interestingly, the levels of SIRT1 and glutathione (GSH) were positively correlated with the degree of Dox-resistance. Dox-induced SIRT1 promoted NRF2 nuclear translocation with an accompanying increase in the antioxidant response element promotor activity and GSH levels. In contrast, inhibition of SIRT1 by EX527 greatly reversed these events. More so, Dox-resistance-induced pro-proliferative, proangiogenic, and invasive effects were obviated with depletion of either SIRT1 or GSH. Together, Dox-induced SIRT1 promotes dysregulation of redox homeostasis leading to breast cancer chemoresistance, tumor aggressiveness, angiogenesis, and metastasis.
    Keywords:  GSH; SIRT1; breast cancer; doxorubicin; drug resistance
    DOI:  https://doi.org/10.1002/mc.23809
  6. J Immunother Cancer. 2024 Aug 13. pii: e009492. [Epub ahead of print]12(8):
       BACKGROUND: Oxylipin metabolism plays an essential role in glioma progression and immune modulation in the tumor microenvironment. Lipid metabolic reprogramming has been linked to macrophage remodeling, while the understanding of oxylipins and their catalyzed enzymes lipoxygenases in the regulation of glioma-associated microglia/macrophages (GAMs) remains largely unexplored.
    METHODS: To explore the pathophysiological relevance of oxylipin in human glioma, we performed Ultra-high performance liquid chromatography-MS/MS (UHPLC-MS/MS) analysis in human glioma and non-tumor brain tissues. To comprehensively investigate the role of arachidonate lipoxygenase 5 (ALOX5) in glioma, we performed in vivo bioluminescent imaging, immunofluorescence staining and flow cytometry analysis on tumors from orthotopic glioma-bearing mice. We developed an ALOX5-targeted nanobody, and tested its anti-glioma efficacy of combination therapy with α-programmed cell death protein-1 (PD-1).
    RESULTS: In this study, we found that ALOX5 and its oxylipin 5-hydroxyeicosatetraenoic acid (5-HETE) are upregulated in glioma, accumulating programmed death-ligand 1 (PD-L1)+ M2-GAMs and orchestrating an immunosuppressive tumor microenvironment. Mechanistically, 5-HETE derived from ALOX5-overexpressing glioma cells, promotes GAMs migration, PD-L1 expression, and M2 polarization by facilitating nuclear translocation of nuclear factor erythroid 2-related factor 2. Additionally, a nanobody targeting ALOX5 is developed that markedly suppresses 5-HETE efflux from glioma cells, attenuates M2 polarization of GAMs, and consequently ameliorates glioma progression. Furthermore, the combination therapy of the ALOX5-targeted nanobody plus α-PD-1 exhibits superior anti-glioma efficacy.
    CONCLUSIONS: Our findings reveal a pivotal role of the ALOX5/5-HETE axis in regulating GAMs and highlight the ALOX5-targeted nanobody as a potential therapeutic agent, which could potentiate immune checkpoint therapy for glioma.
    Keywords:  Immunosuppression; Immunotherapy; Macrophage; Solid tumor
    DOI:  https://doi.org/10.1136/jitc-2024-009492
  7. Nutrients. 2024 Jul 23. pii: 2392. [Epub ahead of print]16(15):
      Breast cancer is the second-leading cause of cancer death among women in the United States. Triple-negative breast cancer (TNBC), a subtype of breast cancer, is an aggressive phenotype that lacks estrogen (ER), progesterone (PR), and human epidermal growth (HER-2) receptors, which is challenging to treat with standardized hormonal therapy. Kaempferol is a natural flavonoid with antioxidant, anti-inflammatory, neuroprotective, and anticancer effects. Besides anti-tumorigenic, antiproliferative, and apoptotic effects, kaempferol protects non-cancerous cells. Kaempferol showed anti-breast cancer effects by inducing DNA damage and increasing caspase 3, caspase 9, and pAMT expression, modifying ROS production by Nrf2 modulation, inducing apoptosis by increasing cleaved PARP and Bax and downregulating Bcl-2 expression, inducing cell cycle arrest at the G2/M phase; inhibiting immune evasion by modulating the JAK-STAT3 pathway; and inhibiting the angiogenic and metastatic potential of tumors by downregulating MMP-3 and MMP-9 levels. Kaempferol holds promise for boosting the efficacy of anticancer agents, complementing their effects, or reversing developed chemoresistance. Exploring novel TNBC molecular targets with kaempferol could elucidate its mechanisms and identify strategies to overcome limitations for clinical application. This review summarizes the latest research on kaempferol's potential as an anti-TNBC agent, highlighting promising but underexplored molecular pathways and delivery challenges that warrant further investigation to achieve successful clinical translation.
    Keywords:  TNBC; apoptosis; breast cancer; chemoresistance; flavonoids; kaempferol; metastasis inhibition; oxidative stress
    DOI:  https://doi.org/10.3390/nu16152392