bims-nurfca 2023-05-28 papers

bims-nurfca

Biomed News

on NRF2 and Cancer

Issue of 2023–05–28
six papers selected by
Caner Geyik, Istinye University

Succinylation of a KEAP1 sensor lysine promotes NRF2 activation.
AKT activation because of PTEN loss upregulates xCT via GSK3β/NRF2, leading to inhibition of ferroptosis in PTEN-mutant tumor cells.
Baicalin induces ferroptosis in osteosarcomas through a novel Nrf2/xCT/GPX4 regulatory axis.
Pedunculoside inhibits epithelial-mesenchymal transition and overcomes Gefitinib-resistant non-small cell lung cancer through regulating MAPK and Nrf2 pathways.
USP14 regulates heme metabolism and ovarian cancer invasion through BACH1 deubiquitination and stabilization.
Isorhamnetin exerts anti-tumor activity in DEN + CCl4-induced HCC mice.

bioRxiv. 2023 May 09. pii: 2023.05.08.539908. [Epub ahead of print]

Succinylation of a KEAP1 sensor lysine promotes NRF2 activation.

Lara Ibrahim, Caroline Stanton, Kayla Nutsch, Thu Nguyen, Chloris Li-Ma, Yeonjin Ko, Gabriel C Lander, R Luke Wiseman, Michael J Bollong.

Crosstalk between metabolism and stress-responsive signaling is essential to maintaining cellular homeostasis. One way this crosstalk is achieved is through the covalent modification of proteins by endogenous, reactive metabolites that regulate the activity of key stress-responsive transcription factors such as NRF2. Several metabolites including methylglyoxal, glyceraldehyde 3-phosphate, fumarate, and itaconate covalently modify sensor cysteines of the NRF2 regulatory protein KEAP1, resulting in stabilization of NRF2 and activation of its cytoprotective transcriptional program. Here, we employed a shRNA-based screen targeting the enzymes of central carbon metabolism to identify additional regulatory nodes bridging metabolic pathways to NRF2 activation. We found that succinic anhydride, increased by genetic depletion of the TCA cycle enzyme succinyl-CoA synthetase or by direct administration, results in N-succinylation of lysine 131 of KEAP1 to activate NRF2 transcriptional signaling. This study identifies KEAP1 as capable of sensing reactive metabolites not only by several cysteine residues but also by a conserved lysine residue, indicating its potential to sense an expanded repertoire of reactive metabolic messengers.

DOI: https://doi.org/10.1101/2023.05.08.539908
Cell Rep. 2023 May 19. pii: S2211-1247(23)00547-8. [Epub ahead of print]42(5): 112536

AKT activation because of PTEN loss upregulates xCT via GSK3β/NRF2, leading to inhibition of ferroptosis in PTEN-mutant tumor cells.

Kaitlyn M Cahuzac, Abigail Lubin, Kaitlyn Bosch, Nicole Stokes, Sarah Mense Shoenfeld, Royce Zhou, Haddy Lemon, John Asara, Ramon E Parsons.

  Here, we show that the tumor suppressor phosphatase and tensin homolog deleted from chromosome 10 (PTEN) sensitizes cells to ferroptosis, an iron-dependent form of cell death, by restraining the expression and activity of the cystine/glutamate antiporter system Xc- (xCT). Loss of PTEN activates AKT kinase to inhibit GSK3β, increasing NF-E2 p45-related factor 2 (NRF2) along with transcription of one of its known target genes encoding xCT. Elevated xCT in Pten-null mouse embryonic fibroblasts increases the flux of cystine transport and synthesis of glutathione, which enhances the steady-state levels of these metabolites. A pan-cancer analysis finds that loss of PTEN shows evidence of increased xCT, and PTEN-mutant cells are resistant to ferroptosis as a consequence of elevated xCT. These findings suggest that selection of PTEN mutation during tumor development may be due to its ability to confer resistance to ferroptosis in the setting of metabolic and oxidative stress that occurs during tumor initiation and progression.

Keywords:  Akt; CP: Cancer; CP: Metabolism; GSK3β; NRF2; PTEN; cancer; cysteine; ferroptosis; glutathione; xCT

DOI:  https://doi.org/10.1016/j.celrep.2023.112536
Phytomedicine. 2023 May 13. pii: S0944-7113(23)00242-8. [Epub ahead of print]116 154881

Baicalin induces ferroptosis in osteosarcomas through a novel Nrf2/xCT/GPX4 regulatory axis.

Rui-Jia Wen, Xin Dong, Hao-Wen Zhuang, Feng-Xiang Pang, Shou-Chang Ding, Nan Li, Yong-Xin Mai, Shu-Ting Zhou, Jun-Yan Wang, Jin-Fang Zhang.

   BACKGROUND: Osteosarcomas (OS) is a kind of malignant bone tumor which occurs primarily in children and adolescents, and the clinical therapeutics remain disappointing. As a new programmed cell death, ferroptosis is characterized by iron dependent and intracellular oxidative accumulation, which provides a potential alternative intervene for the OS treatment. Baicalin, a major bioactive flavone derived from traditional Chinese medicine Scutellaria baicalensis, has been proved to have anti-tumor properties in OS. Whether ferroptosis participated in the baicalin mediated anti-OS activity is an interesting project.
PURPOSE: To explore the pro-ferroptosis effect and mechanisms of baicalin in OS.
METHODS/STUDY DESIGN: Pro-ferroptosis effect of baicalin on cell death, cell proliferation, iron accumulation, lipid peroxidation production was determined in MG63 and 143B cells. The levels of glutathione (GSH), oxidized (GSSG) glutathione and malondialdehyde (MDA) were determined by enzyme linked immunosorbent assay (ELISA). The expression levels of nuclear factor erythroid 2-related factor 2 (Nrf2), Glutathione peroxidase 4 (GPX4) and xCT were detected by western blot in baicalin-mediated ferroptosis regulation. In vivo, a xenograft mice model was adopted to explore the anticancer effect of baicalin.
RESULTS: In the present study, it was found that baicalin significantly suppress tumor cell growth in vitro and in vivo. By promoting the Fe accumulation, ROS formation, MDA production and suppressing the ratio of GSH/GSSG, baicalin was found to trigger ferroptosis in OS and ferroptosis inhibitor ferrostatin-1 (Fer-1) successfully reversed these suppressive effects, indicating that ferroptosis participated in the baicalin mediated anti-OS activity. Mechanistically, baicalin physically interacted with Nrf2, a critical regulator of ferroptosis, and influenced its stability via inducing ubiquitin degradation, which suppressed the Nrf2 downstream targets GPX4 and xCT expression, and led to stimulating ferroptosis.
CONCLUSIONS: Our findings for the first time indicated that baicalin exerted anti-OS activity through a novel Nrf2/xCT/GPX4-dependent ferroptosis regulatory axis, which hopefully provides a promising candidate for OS treatment.

Keywords:  Baicalin; Ferroptosis; GPX4; Nrf2; Osteosarcomas; xCT

DOI:  https://doi.org/10.1016/j.phymed.2023.154881
Phytomedicine. 2023 May 16. pii: S0944-7113(23)00245-3. [Epub ahead of print]116 154884

Pedunculoside inhibits epithelial-mesenchymal transition and overcomes Gefitinib-resistant non-small cell lung cancer through regulating MAPK and Nrf2 pathways.

Qiumei Fan, Xiaowei Liang, Zhipeng Xu, Siyuan Li, Shan Han, Yuntian Xiao, Qiongming Xu, Renyikun Yuan, Shilin Yang, Hongwei Gao.

   BACKGROUND: Lung cancer is the primary cause of cancer-related mortality worldwide owing to its strong metastatic ability. EGFR-TKI (Gefitinib) has demonstrated efficacy in metastatic lung cancer therapy, but most patients ultimately develop resistance to Gefitinib, leading to a poor prognosis. Pedunculoside (PE), a triterpene saponin extracted from Ilex rotunda Thunb., has shown anti-inflammatory, lipid-lowering and anti-tumor effects. Nevertheless, the therapeutic effect and potential mechanisms of PE on NSCLC treatment are unclear.
PURPOSE: To investigate the inhibitory effect and prospective mechanisms of PE on NSCLC metastases and Gefitinib-resistant NSCLC.
METHODS: In vitro, A549/GR cells were established by Gefitinib persistent induction of A549 cells with a low dose and shock with a high dose. The cell migratory ability was measured using wound healing and Transwell assays. Additionally, EMT-related Markers or ROS production were assessed by RT-qPCR, immunofluorescence, Western blotting, and flow cytometry assays in A549/GR and TGF-β1-induced A549 cells. In vivo, B16-F10 cells were intravenously injected into mice, and the effect of PE on tumor metastases were determined using hematoxylin-eosin staining, Caliper IVIS Lumina, DCFH2-DA staining, and western blotting assays.
RESULTS: PE reversed TGF-β1-induced EMT by downregulating EMT-related protein expression through MAPK and Nrf2 pathways, decreasing ROS production, and inhibiting cell migration and invasion ability. Moreover, PE treatment enabled A549/GR cells to retrieve the sensitivity to Gefitinib and mitigate the biological characteristics of EMT. PE also significantly inhibited lung metastasis in mice by reversing EMT proteins expression, decreasing ROS production, and inhibiting MAPK and Nrf2 pathways.
CONCLUSIONS: Collectively, this research presents a novel finding that PE can reverse NSCLC metastasis and improve Gefitinib sensitivity in Gefitinib-resistant NSCLC through the MAPK and Nrf2 pathways, subsequently suppressing lung metastasis in B16-F10 lung metastatic mice model. Our findings indicate that PE is a potential agent for inhibiting metastasis and improving Gefitinib resistance in NSCLC.

Keywords:  EMT; Gefitinib resistance; MAPK; Nrf2; Pedunculoside; ROS

DOI:  https://doi.org/10.1016/j.phymed.2023.154884
Biochem Biophys Res Commun. 2023 May 12. pii: S0006-291X(23)00505-3. [Epub ahead of print]667 186-193

USP14 regulates heme metabolism and ovarian cancer invasion through BACH1 deubiquitination and stabilization.

Jing Ji, Jinyu Lv, Mingxiao Lv, Aixin Jing, Menghan Xu, Qing Yuan, Xinhui Ma, Qilan Qian, Weiling Wang, Ting Geng, Yuanyuan Ding, Jingting Qin, Yuanyuan Liu, Jiayan Yang, Jiaojiao Zhou, Ling Ma, Yasong Wang, Lingyi Zuo, XiuJun Wang, Shaojie Ma, Bin Liu.

  The deubiquitinating enzyme USP14 has been established as a crucial regulator in various diseases, including tumors, neurodegenerative diseases, and metabolic diseases, through its ability to stabilize its substrate proteins. Our group has utilized proteomic techniques to identify new potential substrate proteins for USP14, however, the underlying signaling pathways regulated by USP14 remain largely unknown. Here, we demonstrate the key role of USP14 in both heme metabolism and tumor invasion by stabilizing the protein BACH1. The cellular oxidative stress response factor NRF2 regulates antioxidant protein expression through binding to the antioxidant response element (ARE). BACH1 can compete with NRF2 for ARE binding, leading to the inhibition of the expression of antioxidant genes, including HMOX-1. Activated NRF2 also inhibits the degradation of BACH1, promoting cancer cell invasion and metastasis. Our findings showed a positive correlation between USP14 expression and NRF2 expression in various cancer tissues from the TCGA database and normal tissues from the GTEx database. Furthermore, activated NRF2 was found to increase USP14 expression in ovarian cancer (OV) cells. The overexpression of USP14 was observed to inhibit HMOX1 expression, while USP14 knockdown had the opposite effect, suggesting a role for USP14 in regulating heme metabolism. The depletion of BACH1 or inhibition of heme oxygenase 1 (coded by HMOX-1) was also found to significantly impair USP14-dependent OV cell invasion. In conclusion, our results highlight the importance of the NRF2-USP14-BACH1 axis in regulating OV cell invasion and heme metabolism, providing evidence for its potential as a therapeutic target in related diseases.

Keywords:  BACH1; Heme metabolism; Invasion; NRF2; USP14

DOI:  https://doi.org/10.1016/j.bbrc.2023.04.082
Med Oncol. 2023 May 24. 40(7): 188

Isorhamnetin exerts anti-tumor activity in DEN + CCl4-induced HCC mice.

Sayanta Sarkar, Abhishek Kumar Das, Semantee Bhattacharya, Ratan Gachhui, Parames C Sil.

   BACKGROUND: Hepatocellular carcinoma (HCC) is the most prevalent type of liver cancer and the main cause of cancer death globally. The use of medicinal herbs as chemotherapeutic agents in cancer treatment is receiving attention as they possess no or minimum side effects. Isorhamnetin (IRN), a flavonoid, has been under attention for its anti-inflammatory and anti-proliferative properties in a number of cancers, including colorectal, skin, and lung cancers. However, the in vivo mechanism of isorhamnetin to suppress liver cancer has yet to be explored.
METHODS AND RESULT: HCC was induced by N-diethylnitrosamine (DEN) and carbon tetrachloride (CCL4) in Swiss albino mice. Isorhamnetin (100 mg/kg body weight) was given to examine its anti-tumor properties in HCC mice model. Histological analysis and liver function assays were performed to assess changes in liver anatomy. Probable molecular pathways were explored using immunoblot, qPCR, ELISA, and immunohistochemistry techniques. Isorhamnetin inhibited various pro-inflammatory cytokines to suppress cancer-inducing inflammation. Additionally, it regulated Akt and MAPKs to suppress Nrf2 signaling. Isorhamnetin activated PPAR-γ and autophagy while suppressing cell cycle progression in DEN + CCl4-administered mice. Additionally, isorhamnetin regulated various signaling pathways to suppress cell proliferation, metabolism, and epithelial-mesenchymal transition in HCC.
CONCLUSION: Regulating diverse cellular signaling pathways makes isorhamnetin a better anti-cancer chemotherapeutic candidate in HCC. Importantly, the anti-TNF-α properties of isorhamnetin could prove it a valuable therapeutic agent in sorafenib-resistant HCC patients. Additionally, anti-TGF-β properties of isorhamnetin could be utilized to reduce the EMT-inducing side effects of doxorubicin.

Keywords:  Hepatocellular carcinoma; Inflammation; Isorhamnetin; MAPKs; Nrf2 signaling

DOI:  https://doi.org/10.1007/s12032-023-02050-5