bims-nurfca 2024-07-28 papers

bims-nurfca

Biomed News

on NRF2 and Cancer

Issue of 2024–07–28
fiveteen papers selected by
Caner Geyik, Istinye University

NRF2 Signaling Pathway in Chemo/Radio/Immuno-Therapy Resistance of Lung Cancer: Looking Beyond the Tip of the Iceberg.
HIPK2 in Colon Cancer: A Potential Biomarker for Tumor Progression and Response to Therapies.
Redox-state-regulating enzymes have prognostic value in diabetic endometrial cancer patients: impact of statin use?
Baicalin promotes the sensitivity of NSCLC to cisplatin by regulating ferritinophagy and macrophage immunity through the KEAP1-NRF2/HO-1 pathway.
Cepharanthine triggers ferroptosis through inhibition of NRF2 for robust ER stress against lung cancer.
BUB1b impairs chemotherapy sensitivity via resistance to ferroptosis in lung adenocarcinoma.
UBE2C regulates the KEAP1/NRF2 signaling pathway to promote the growth of gastric cancer by inhibiting autophagy.
Tamoxifen metabolites treatment promotes ERα+ transition to triple negative phenotype in vitro, effects of LDL in chemoresistance.
STAT3 Regulates the Redox Profile in MDA-MB-231 Breast Cancer Cells.
The Induction of G2/M Phase Cell Cycle Arrest and Apoptosis by the Chalcone Derivative 1C in Sensitive and Resistant Ovarian Cancer Cells Is Associated with ROS Generation.
Enhancing Therapeutic Approaches in Glioblastoma with Pro-Oxidant Treatments and Synergistic Combinations: In Vitro Experience of Doxorubicin and Photodynamic Therapy.
Tumoral Malignancy Decreases Coupled with Higher ROS and Lipid Peroxidation in HCT116 Colon Cancer Cells upon Loss of PRDX6.
Ropivacaine prompts ferroptosis to enhance the cisplatin-sensitivity of human colorectal cancer through SIRT1/Nrf2 signaling pathway.
Detection of ROS in Dormant Breast Cancer Cell.
Effects of KRAS, STK11, KEAP1, and TP53 mutations on the clinical outcomes of immune checkpoint inhibitors among patients with lung adenocarcinoma.

Arch Bronconeumol. 2024 Jul 15. pii: S0300-2896(24)00267-9. [Epub ahead of print]

NRF2 Signaling Pathway in Chemo/Radio/Immuno-Therapy Resistance of Lung Cancer: Looking Beyond the Tip of the Iceberg.

Sri Vidya Ramisetti, Tapas Patra, Vinayak Munirathnam, Jyothi Venkat Sainath, Durgadevi Veeraiyan, Akhileshwar Namani.

  Lung cancer is one of the most common causes of cancer death in men and women worldwide. Various combinations of surgery, chemotherapy, radiation therapy and immunotherapy are currently used to treat lung cancer. However, the prognosis remains relatively poor due to the higher frequency of tumor mutational burden (TMB). Nuclear factor E2-related factor 2 (NFE2L2/NRF2) is often considered a primary regulator of the expression of antioxidant enzymes and detoxification proteins and is involved in cytoprotection. On the contrary, NRF2 is even known to induce metastasis and support tumor progression. Kelch-like ECH-associated protein 1 (KEAP1) plays an important role in negatively regulating NRF2 activity via CUL3-mediated ubiquitinylation and successive proteasomal degradation. Extensive research has shown that the genetic alterations of KEAP1/NFE2L2/CUL3 genes lead to increased expression of NRF2 and its target genes in lung cancer. Thus, these studies provide ample evidence for the dual role of NRF2 in lung cancer. In this review, we discussed the mechanistic insights into the role of NRF2 signaling in therapy resistance by focusing on cell lines, mouse models, and translational studies in lung cancer. Finally, we highlighted the potential therapeutic strategies targeting NRF2 inhibition, followed by the discussion of biomarkers related to NRF2 activity in lung cancer. Overall, our article exclusively discusses in detail the NRF2 signaling pathway in resistance to therapy, especially immunotherapy, and its therapeutic avenue in the treatment of lung cancer.

Keywords:  Biomarkers; Lung cancer; NRF2 signaling; Oxidative stress; Therapy resistance

DOI:  https://doi.org/10.1016/j.arbres.2024.06.021
Int J Mol Sci. 2024 Jul 12. pii: 7678. [Epub ahead of print]25(14):

HIPK2 in Colon Cancer: A Potential Biomarker for Tumor Progression and Response to Therapies.

Alessandra Verdina, Alessia Garufi, Valerio D'Orazi, Gabriella D'Orazi.

  Colon cancer, one of the most common and fatal cancers worldwide, is characterized by stepwise accumulation of specific genetic alterations in tumor suppressor genes or oncogenes, leading to tumor growth and metastasis. HIPK2 (homeodomain-interacting protein kinase 2) is a serine/threonine protein kinase and a "bona fide" oncosuppressor protein. Its activation inhibits tumor growth mainly by promoting apoptosis, while its inactivation increases tumorigenicity and resistance to therapies of many different cancer types, including colon cancer. HIPK2 interacts with many molecular pathways by means of its kinase activity or transcriptional co-repressor function modulating cell growth and apoptosis, invasion, angiogenesis, inflammation and hypoxia. HIPK2 has been shown to participate in several molecular pathways involved in colon cancer including p53, Wnt/β-catenin and the newly identified nuclear factor erythroid 2 (NF-E2) p45-related factor 2 (NRF2). HIPK2 also plays a role in tumor-host interaction in the tumor microenvironment (TME) by inducing angiogenesis and cancer-associated fibroblast (CAF) differentiation. The aim of this review is to assess the role of HIPK2 in colon cancer and the underlying molecular pathways for a better understanding of its involvement in colon cancer carcinogenesis and response to therapies, which will likely pave the way for novel colon cancer therapies.

Keywords:  HIPK2; NRF2; Wnt/β-catenin; angiogenesis; cancer therapy; colon cancer; colorectal cancer; hyperglycemia; hypoxia; microRNA; p53; tumor inflammation

DOI:  https://doi.org/10.3390/ijms25147678
Front Oncol. 2024 ;14 1393103

Redox-state-regulating enzymes have prognostic value in diabetic endometrial cancer patients: impact of statin use?

Elina Ollila, Anne Ahtikoski, Ulla Puistola, Peeter Karihtala, Elina Urpilainen.

   Objective: The incidence of endometrial cancer is increasing, and oxidative stress has been suggested to play a vital role in its carcinogenesis. Statins have an impact on the cellular redox-state. The aim of this study was to determine the effects of statin use on redox-state regulating enzymes in endometrial cancer in women with type 2 diabetes.
Materials and methods: This retrospective study consisted of 119 women with type 2 diabetes who were diagnosed with endometrial cancer at Oulu University Hospital in Finland between 2007 and 2014. There were 58 statin users and 61 non-users based on medication use at the time of endometrial cancer diagnosis. The expression of redox-state regulating proteins nuclear factor erythroid 2-related factor 2 (Nrf2) and Kelch-like ECH-associated protein 1 (Keap1) in the tumor samples was assessed immunohistochemically, and manganese superoxide dismutase (MnSOD) levels were measured both immunohistochemically and from serum samples.
Results: High MnSOD expression predicted better progression-free survival (PFS) in statin non-users in a univariate analysis (p=0.02). There was no statistical difference in overall survival (OS) or PFS between strong and weak expression of Nrf2 and Keap1. After adjusting for stage and statin use, the results were similar.
Conclusion: Statin non-users with strong MnSOD expression had better PFS compared to statin users which proves that statins have impact on redox-state regulating enzymes. However, these findings are preliminary and require further research.

Keywords:  KEAP1; MnSOD; Nrf2; oxidative stress; type 2 diabetes

DOI:  https://doi.org/10.3389/fonc.2024.1393103
Eur J Med Res. 2024 Jul 26. 29(1): 387

Baicalin promotes the sensitivity of NSCLC to cisplatin by regulating ferritinophagy and macrophage immunity through the KEAP1-NRF2/HO-1 pathway.

Yang Chen, Shujun Bao, Zhongzhao Wang, Zheng Fang, Hao Tang.

   BACKGROUND: Cisplatin (DDP) chemotherapy is commonly used in therapy for non-small cell lung cancer (NSCLC), but increased drug resistance has become a huge obstacle. Baicalin (BA) contributed to the sensitivity of NSCLC to DDP. Here, we aimed to further probe the pathophysiological mechanisms of BA in NSCLC.
METHODS: A549 and A549/DDP cells and xenograft mice were treated with BA and DDP. Xenograft mice were treated additionally with the NRF2 inducer (Bardoxolone methyl, BM) and KEAP1 knockdown. The levels of ferritinophagy-related proteins and biomarkers were determined. The autophagosomes were observed. M1 macrophage polarization and the contents of related indicators were analyzed. The involvement of KEAP1/NRF2/HO-1 was determined.
RESULTS: BA inhibited cell development, and the effect of BA and DDP on cell development was additive. The abundance of ferritinophagy-related proteins and the number of autophagosomes were induced by BA. BA also promoted the transition of GSH to GSSH. BA favored M1 macrophage polarization and affected the expression of related proteins. When BA and DDP combined, these molecular phenomena were further exacerbated. BA induced accumulation of KEAP1 and reduction of NRF2 and HO-1. However, BM and KEAP1 knockdown disrupted the synergistic effects of BA and DDP on inhibiting NSCLC growth. BM and KEAP1 knockdown reversed DDP and BA-promoted protein expression activity and M1 macrophage polarization.
CONCLUSION: Our findings suggest that BA is involved in ferritinophagy and macrophage immunity through the KEAP1-NRF2/HO-1 axis, thereby improving the DDP sensitivity in NSCLC, which could provide new candidates for treatment strategies.

Keywords:  Baicalin (BA); Cisplatin (DDP); KEAP1-NRF2/HO-1; Non-small cell lung cancer (NSCLC)

DOI:  https://doi.org/10.1186/s40001-024-01930-4
Eur J Pharmacol. 2024 Jul 20. pii: S0014-2999(24)00528-4. [Epub ahead of print]979 176839

Cepharanthine triggers ferroptosis through inhibition of NRF2 for robust ER stress against lung cancer.

Xiao-Feng Bai, Jun Hu, Mei-Fang Wang, Liu-Gen Li, Ning Han, Hansheng Wang, Nan-Nan Chen, Yu-Jie Gao, Hui You, Xiao Wang, Xiang Xu, Ting-Ting Yu, Tong-Fei Li, Tao Ren.

   BACKGROUND: Severe endoplasmic reticulum (ER) stress elicits apoptosis to suppress lung cancer. Our previous research identified that Cepharanthine (CEP), a kind of phytomedicine, possessed powerful anti-cancer efficacy, for which the underlying mechanism was still uncovered. Herein, we investigated how CEP induced ER stress and worked against lung cancer.
METHODS: The differential expression genes (DEGs) and enrichment were detected by RNA-sequence. The affinity of CEP and NRF2 was analyzed by cellular thermal shift assay (CETSA) and molecular docking. The function assay of lung cancer cells was measured by western blots, flow cytometry, immunofluorescence staining, and ferroptosis inhibitors.
RESULTS: CEP treatment enriched DEGs in ferroptosis and ER stress. Further analysis demonstrated the target was NRF2. In vitro and in vivo experiments showed that CEP induced obvious ferroptosis, as characterized by the elevated iron ions, ROS, COX-2 expression, down-regulation of GPX4, and atrophic mitochondria. Moreover, enhanced Grp78, CHOP expression, β-amyloid mass, and disappearing parallel stacked structures of ER were observed in CEP group, suggesting ER stress was aroused. CEP exhibited excellent anti-lung cancer efficacy, as evidenced by the increased apoptosis, reduced proliferation, diminished cell stemness, and prominent inhibition of tumor grafts in animal models. Furthermore, the addition of ferroptosis inhibitors weakened CEP-induced ER stress and apoptosis.
CONCLUSION: In summary, our findings proved CEP drives ferroptosis through inhibition of NRF2 for induction of robust ER stress, thereby leading to apoptosis and attenuated stemness of lung cancer cells. The current work presents a novel mechanism for the anti-tumor efficacy of the natural compound CEP.

Keywords:  Cepharanthine (CEP); ER stress; Ferroptosis; KEAP1/NRF2; Lung cancer

DOI:  https://doi.org/10.1016/j.ejphar.2024.176839
Cell Death Dis. 2024 Jul 23. 15(7): 525

BUB1b impairs chemotherapy sensitivity via resistance to ferroptosis in lung adenocarcinoma.

Yanguang Ding, Jian Gao, Jun Chen, Jinmei Ren, Jiahao Jiang, Zhiqiang Zhang, Xin Tong, Jun Zhao.

BUB1 mitotic checkpoint serine/threonine kinase B (BUB1b) has been unequivocally identified as an oncogene in various cancers. However, the potential mechanism by which BUB1b orchestrates the progression of lung adenocarcinoma (LUAD) remains unclear. Here we found that both the transcript and protein levels of BUB1b were dramatically upregulated in tumor tissues and contributed to the dismal prognosis of LUAD patients. Moreover, gain- and loss-of-function assays, conducted both in vitro and in vivo, confirmed that BUB1b enhanced the viability of LUAD cells. Mechanistically, BUB1b forms a complex with OTUD3 and NRF2 and stabilizes the downstream NRF2 signaling pathway to facilitate insensitivity to ferroptosis and chemotherapy. In BALB/c nude mice bearing subcutaneous tumors that overexpress BUB1b, a combined strategy of ML385 targeting and chemotherapy achieved synergistic effects, inhibiting tumor growth and obviously improving survival. Taken together our study uncovered the underlying mechanism by which BUB1b promotes the progression of LUAD and proposed a novel strategy to enhance the efficacy of chemotherapy.

DOI: https://doi.org/10.1038/s41419-024-06914-0
Int J Biol Macromol. 2024 Jul 18. pii: S0141-8130(24)04816-5. [Epub ahead of print] 134011

UBE2C regulates the KEAP1/NRF2 signaling pathway to promote the growth of gastric cancer by inhibiting autophagy.

Yunhe Jiang, Bin Liu, Lifu Fu, Fan Li.

  Gastric cancer (GC) is one of the most common malignant tumors in the world, ranking fourth in incidence and second in mortality among malignant tumors. In recent years, there has been some progress in biological treatment and targeted treatment for gastric cancer, but the prognosis for gastric cancer patients remains pessimistic, and the molecular mechanisms involved are not yet clear. In this study, bioinformatics analysis showed that Ubiquitin-conjugating enzyme E2C(UBE2C) was abnormally expressed in various types of cancer. Furthermore, UBE2C protein and mRNA expression was significantly elevated in gastric cancer tissues and cells. Silencing UBE2C significantly inhibited the proliferation and migration of gastric cancer cells. Mechanistically, UBE2C overexpression inhibited gastric cancer cell autophagy, leading to the accumulation of p62. Furthermore, immunoprecipitation results showed that UBE2C overexpression promoted the interaction between p62 and KEAP1, while inhibiting the binding of NRF2 to KEAP1, thereby weakening the ubiquitination and degradation of NRF2. In addition, the silencing of UBE2C leads to a reduction in the nuclear accumulation of NRF2. Importantly, the NRF2 activator TBHQ reversed the inhibition of gastric cancer cell proliferation and migration caused by the silencing of UBE2C. In summary, our study provides new insights into the molecular mechanisms of UBE2C in anti-cancer therapy.

Keywords:  Autophagy; Gastric cancer; NRF2; TBHQ; UBE2C

DOI:  https://doi.org/10.1016/j.ijbiomac.2024.134011
Biosci Rep. 2024 Jul 19. pii: BSR20240444. [Epub ahead of print]

Tamoxifen metabolites treatment promotes ERα+ transition to triple negative phenotype in vitro, effects of LDL in chemoresistance.

Andrea Muñoz-Ayala, Brenda Chimal-Vega, Nicolás Serafín-Higuera, Octavio Galindo-Hernández, Gladys Eloísa Ramírez-Rosales, Iván Córdova-Guerrero, Luis Fernando Gómez-Lucas, Victor García-González.

   OBJECTIVE: Estrogen receptor-positive (ER+) breast cancer represents about 80 % of cases, tamoxifen is the election neoadjuvant chemotherapy. However, a large percentage of patients develop chemoresistance, compromising recovery. Clinical evidence suggests that high plasmatic levels of low-density lipoproteins (LDL) could promote cancer progression. The present study analyzed the effect of LDL on the primary plasmatic active Tamoxifen´s metabolites resistance acquisition, 4-hydroxytamoxifen (4OH-Tam) and 4-hydroxy-N-desmethyl-tamoxifen (endoxifen), in breast cancer ER+ cells (MCF-7).
METHODS: Two resistant cellular variants, MCF-7Var-H and MCF-7Var-I, were generated by a novel strategy and their phenotype features were evaluated. Phenotypic assessment was performed by MTT assays, cytometry, immunofluorescence microscopy, zymography and protein expression analysis.
RESULTS: MCF-7Var-H, generated only with tamoxifen metabolites, showed a critical down-regulation in hormone receptors, augmented migration capacity, metalloprotease 9 extracellular medium excretion, and a mesenchymal morphology in contrast with native MCF-7, suggesting the transition towards Triple-negative breast cancer (TNBC) phenotype. In contrast, MCF-7Var-I which was generated in a high LDL media, showed only a slight upregulation in ER and other less noticeable metabolic adaptations. Results suggest a potential role of transcription factor nuclear factor erythroid 2-related factor 2 (Nrf2) in phenotypic differences observed among variants.
CONCLUSION: LDL high or low concentrations during Tamoxifen´s metabolites chemoresistance acquisition leads to different cellular mechanisms related to chemoresistance. A novel adaptative cellular response associated with Nrf2 activity could be implicated.

Keywords:  Nrf2; breast cancers; chemoresistance; metastasis; tamoxifen

DOI:  https://doi.org/10.1042/BSR20240444
Cell Biochem Biophys. 2024 Jul 20.

STAT3 Regulates the Redox Profile in MDA-MB-231 Breast Cancer Cells.

Juliana Alves Rodrigues, Bruno Ricardo Barreto Pires, Isis Salviano Soares de Amorim, Priscyanne Barreto Siqueira, Mariana Moreno de Sousa Rodrigues, Adenilson de Souza da Fonseca, Carolina Panis, Andre Luiz Mencalha.

  Unbalanced redox status and constitutive STAT3 activation are related to several aspects of tumor biology and poor prognosis, including metastasis and drug resistance. The triple-negative breast cancer (TNBC) is listed as the most aggressive and exhibits the worst prognosis among the breast cancer subtypes. Although the mechanism of reactive oxygen species (ROS) generation led to STAT3 activation is described, there is no data concerning the STAT3 influence on redox homeostasis in TNBC. To address the role of STAT3 signaling in redox balance, we inhibited STAT3 in TNBC cells and investigated its impact on total ROS levels, contents of hydroperoxides, nitric oxide (NO), and total glutathione (GSH), as well as the expression levels of 3-nitrotyrosine (3NT), nuclear factor (erythroid-derived 2)-like 2 (Nrf2), and nuclear factor kappa B (NF-κB)/p65. Our results indicate that ROS levels depend on the STAT3 activation, while the hydroperoxide level remained unchanged, and NO and 3NT expression increased. Furthermore, GSH levels, Nrf2, and NF-κB/p65 protein levels are decreased in the STAT3-inhibited cells. Accordingly, TNBC patients' data from TCGA demonstrated that both STAT3 mRNA levels and STAT3 signature are correlated to NF-κB/p65 and Nrf2 signatures. Our findings implicate STAT3 in controlling redox balance and regulating redox-related genes' expression in triple-negative breast cancer.

Keywords:  Breastcancer; Redox; STAT3; TNBC

DOI:  https://doi.org/10.1007/s12013-024-01439-x
Int J Mol Sci. 2024 Jul 09. pii: 7541. [Epub ahead of print]25(14):

The Induction of G2/M Phase Cell Cycle Arrest and Apoptosis by the Chalcone Derivative 1C in Sensitive and Resistant Ovarian Cancer Cells Is Associated with ROS Generation.

Šimon Salanci, Mária Vilková, Lola Martinez, Ladislav Mirossay, Radka Michalková, Ján Mojžiš.

  Ovarian cancer ranks among the most severe forms of cancer affecting the female reproductive organs, posing a significant clinical challenge primarily due to the development of resistance to conventional therapies. This study investigated the effects of the chalcone derivative 1C on sensitive (A2780) and cisplatin-resistant (A2780cis) ovarian cancer cell lines. Our findings revealed that 1C suppressed cell viability, induced cell cycle arrest at the G2/M phase, and triggered apoptosis in both cell lines. These effects are closely associated with generating reactive oxygen species (ROS). Mechanistically, 1C induced DNA damage, modulated the activity of p21, PCNA, and phosphorylation of Rb and Bad proteins, as well as cleaved PARP. Moreover, it modulated Akt, Erk1/2, and NF-κB signaling pathways. Interestingly, we observed differential effects of 1C on Nrf2 levels between sensitive and resistant cells. While 1C increased Nrf2 levels in sensitive cells after 12 h and decreased them after 48 h, the opposite effect was observed in resistant cells. Notably, most of these effects were suppressed by the potent antioxidant N-acetylcysteine (NAC), underscoring the crucial role of ROS in 1C-induced antiproliferative activity. Moreover, we suggest that modulation of Nrf2 levels can, at least partially, contribute to the antiproliferative effect of chalcone 1C.

Keywords:  G2/M arrest; N-acetylcysteine; Nrf2; antiproliferative; apoptosis; chalcones; ovarian cancer; oxidative stress

DOI:  https://doi.org/10.3390/ijms25147541
Int J Mol Sci. 2024 Jul 09. pii: 7525. [Epub ahead of print]25(14):

Enhancing Therapeutic Approaches in Glioblastoma with Pro-Oxidant Treatments and Synergistic Combinations: In Vitro Experience of Doxorubicin and Photodynamic Therapy.

Bruno Agustín Cesca, Matías Daniel Caverzan, María Julia Lamberti, Luis Exequiel Ibarra.

  Glioblastoma (GBM) is an aggressive brain cancer characterized by significant molecular and cellular heterogeneity, which complicates treatment efforts. Current standard therapies, including surgical resection, radiation, and temozolomide (TMZ) chemotherapy, often fail to achieve long-term remission due to tumor recurrence and resistance. A pro-oxidant environment is involved in glioma progression, with oxidative stress contributing to the genetic instability that leads to gliomagenesis. Evaluating pro-oxidant therapies in brain tumors is crucial due to their potential to selectively target and eradicate cancer cells by exploiting the elevated oxidative stress levels inherent in these malignant cells, thereby offering a novel and effective strategy for overcoming resistance to conventional therapies. This study investigates the therapeutic potential of doxorubicin (DOX) and photodynamic therapy (PDT) with Me-ALA, focusing on their effects on redox homeostasis. Basal ROS levels and antioxidant gene expression (NFE2L2, CAT, GSR) were quantitatively assessed across GBM cell lines, revealing significant variability probably linked to genetic differences. DOX and PDT treatments, both individually and in combination, were analyzed for their efficacy in inducing oxidative stress and cytotoxicity. An in silico analysis further explored the relationship between gene mutations and oxidative stress in GBM patients, providing insights into the molecular mechanisms underlying treatment responses. Our findings suggest that pro-oxidant therapies, such as DOX and PDT in combination, could selectively target GBM cells, highlighting a promising avenue for improving therapeutic outcomes in GBM.

Keywords:  PTEN mutation; TP53 mutation; adjuvant treatment; chemotherapy; glioblastoma; oxidative therapy; photodynamic therapy

DOI:  https://doi.org/10.3390/ijms25147525
Antioxidants (Basel). 2024 Jul 22. pii: 881. [Epub ahead of print]13(7):

Tumoral Malignancy Decreases Coupled with Higher ROS and Lipid Peroxidation in HCT116 Colon Cancer Cells upon Loss of PRDX6.

Daniel J Lagal, Antonio M Montes-Osuna, Alberto Ortiz-Olivencia, Candela Arribas-Parejas, Ángel Ortiz-Alcántara, Cristina Pescuezo-Castillo, José Antonio Bárcena, Carmen Alicia Padilla, Raquel Requejo-Aguilar.

  Peroxiredoxin 6 (PRDX6) is an atypical member of the peroxiredoxin family that presents not only peroxidase but also phospholipase A2 and lysophosphatidylcholine acyl transferase activities able to act on lipid hydroperoxides of cell membranes. It has been associated with the proliferation and invasive capacity of different tumoral cells including colorectal cancer cells, although the effect of its removal in these cells has not been yet studied. Here, using CRISPR/Cas9 technology, we constructed an HCT116 colorectal cancer cell line knockout for PRDX6 to study whether the mechanisms described for other cancer cells in terms of proliferation, migration, and invasiveness also apply in this tumoral cell line. HCT116 cells lacking PRDX6 showed increased ROS and lipid peroxidation, a decrease in the antioxidant response regulator NRF2, mitochondrial dysfunction, and increased sensitivity to ferroptosis. All these alterations lead to a decrease in proliferation, migration, and invasiveness in these cells. Furthermore, the reduced migratory and invasive capacity of HCT116 cancer cells is consistent with the observed cadherin switch and decrease in pro-invasive proteins such as MMPs. Therefore, the mechanism behind the effects of loss of PRDX6 in HCT116 cells could differ from that in HepG2 cells which is coherent with the fact that the correlation of PRDX6 expression with patient survival is different in hepatocellular carcinomas. Nonetheless, our results point to this protein as a good therapeutic target also for colorectal cancer.

Keywords:  ROS; cancer; lipid peroxidation; malignancy; peroxiredoxin 6

DOI:  https://doi.org/10.3390/antiox13070881
Chem Biol Interact. 2024 Jul 23. pii: S0009-2797(24)00309-0. [Epub ahead of print] 111163

Ropivacaine prompts ferroptosis to enhance the cisplatin-sensitivity of human colorectal cancer through SIRT1/Nrf2 signaling pathway.

Lian Zeng, WenBo Zhao, Tiantian Han, Fangfang Qing, Zhongshi He, Qiang Zhao, Ailin Luo, Pengchao Hu, Xudong Ding, Zhen Zhang.

  The ineffectiveness of cisplatin therapy in treating colorectal cancer (CRC) is attributed to an increase of resistance. It's necessary to investigate adjunctive agents capable of enhancing drug efficacy. Previous studies have shown that ropivacaine inhibit the growth of various cancer cells, but its impact on cisplatin resistance in tumors is not well understood. This study was to illustrate the impact and mechanism of ropivacaine enhanced cisplatin-sensitivity of CRC. Cisplatin alone treatment resulted in the elevation of reactive oxygen species (ROS) and intracellular Fe2+ levels, as well as a reduction in mitochondrial membrane potential (MMP) in cisplatin-sensitive LOVO cells, while these effects were mitigated in the cisplatin-resistant LOVO/DDP cells. The co-administration of ropivacaine with cisplatin inhibited cell viability and cell migration, decreased MMP, and promoted ROS accumulation and apoptosis in both LOVO cells and LOVO/DDP cells. And they upregulated the levels of ferroptosis makers and downregulated the expression of anti-ferroptosis proteins. However, this effect was reversed by ferroptosis inhibitor ferrostatin-1 or liproxstatin-1. Furthermore, we o demonstrated that the co-administration of ropivacaine and cisplatin resulted in a decrease in SIRT1 expression, and SIRT1 knockdown in LOVO/DDP cells enhanced the ferroptosis and the anti-tumor properties of ropivacaine, while also inhibiting the activation of the Nrf2/Keap1 pathway. The above results suggested that ropivacaine increased the sensitivity of CRC cells to cisplatin by promoting ferroptosis through the inhibition of SIRT1 expression, which proposes a therapeutic approach for overcoming cisplatin resistance in CRC.

Keywords:  Apoptosis; Cisplatin resistance; Ferroptosis; Human colorectal cancer cells (LOVO; LOVO/DDP); Ropivacaine

DOI:  https://doi.org/10.1016/j.cbi.2024.111163
Methods Mol Biol. 2024 ;2811 185-193

Detection of ROS in Dormant Breast Cancer Cell.

Patrizia Romani, Sirio Dupont.

  Reactive oxygen species (ROS) production can occur both as a physiological response and because of oxidative stress. ROS are not only the end product of nonfunctional cell processes but also signaling molecules that can regulate cell and tissue homeostasis. Recently, we have discovered that metastatic breast cancer cells that lay dormant in the lung microenvironment activate mitochondrial ROS production in response to the mechanical properties of the ECM, which triggers an antioxidant response mediated by the NRF2 transcription factor. In turn, this response protects dormant metastatic cells from cisplatin chemotherapy. Many tools have been developed to monitor ROS production in cells in culture, while our ability to detect this in vivo remains limited. Here we describe a detailed protocol for determination of ROS in metastatic cells in the mouse lung tissue by detecting 4-hydroxy-2-noneal (4HNE) adducts formation in fixed tissues.

Keywords:  4HNE; Frozen tissue; Immunostaining; Lipid peroxidation; ROS

DOI:  https://doi.org/10.1007/978-1-0716-3882-8_14
PLoS One. 2024 ;19(7): e0307580

Effects of KRAS, STK11, KEAP1, and TP53 mutations on the clinical outcomes of immune checkpoint inhibitors among patients with lung adenocarcinoma.

Yao Liang, Osamu Maeda, Chiaki Kondo, Kazuki Nishida, Yuichi Ando.

BACKGROUND: This study aimed to identify the associations between individual KRAS, STK11, KEAP1, or TP53 mutations, as well as the comutation status of these genes, and the tumor mutation burden (TMB) with clinical outcomes of lung adenocarcinoma patients treated with immune checkpoint inhibitors (ICIs).
METHODS: We collected data from patients with lung adenocarcinoma treated with ICIs from the Center for Cancer Genomics and Advanced Therapeutics (C-CAT) database between June 2019 and August 2023. The main endpoints were the treatment response and overall survival (OS).
RESULTS: Among 343 patients with lung adenocarcinoma, 61 (18%), 69 (20%), 41 (12%), and 222 (65%) patients had KRAS, STK11, KEAP1, and TP53 mutations, respectively. An overall objective response was observed in 94 of 338 patients (28%), including 2 (1%) who achieved a complete response and 92 (27%) who achieved a partial response. Patients with STK11, KEAP1, or TP53 mutations had a significantly greater TMB (P<0.001). According to the univariate analysis, the treatment response was significantly correlated with TP53 mutation in both the general (P = 0.041) and KRAS wild-type (P = 0.009) populations. KEAP1 and TP53 mutations were associated with worse OS among assessable patients (hazard ratio (HR) = 2.027, P = 0.002; HR = 1.673, P = 0.007, respectively) and among patients without KRAS mutations (HR = 1.897, P = 0.012; HR = 1.908, P = 0.004, respectively). According to the multivariate analysis, KEAP1 (HR = 1.890, P = 0.008) and TP53 (HR = 1.735, P = 0.011) mutations were found to be independent factors for OS.
CONCLUSIONS: STK11, KEAP1, and TP53 mutations are significantly associated with a high TMB. TP53 mutation could affect the treatment response to some degree, and both KEAP1 and TP53 mutations resulted in inferior OS in the general patient population and in those with KRAS-wild-type lung adenocarcinoma, indicating that KEAP1 and TP53 mutations might act as prognostic factors for ICI treatment in lung adenocarcinoma patients.

DOI: https://doi.org/10.1371/journal.pone.0307580