Therapeutic targeting of thioredoxin reductase 1 causes ferroptosis while potentiating anti-PD-1 efficacy in head and neck cancer

Head and neck squamous cell carcinoma (HNSCC) faces low response rates to anti-PD-1 immunotherapies, highlighting the need for enhanced treatment strategies. Auranofin, which inhibits thioredoxin reductase (TrxR) through its gold-based composition, has shown potential in cancer treatment. It targets the TrxR system, essential for safeguarding cells from oxidative stress. The overproduction of TrxR in cancerous cells supports their proliferation. However, auranofin's interference with this system can upset the cellular redox equilibrium, boost levels of reactive oxygen species, and trigger the death of cancer cells. This study is the first to highlight TXNRD1 as a crucial factor contributing to resistance to anti-PD-1 treatment in HNSCC. In this study, we identified targetable regulators of resistance to immunotherapy-induced ferroptosis in HNSCC. We observed a link of thioredoxin reductase 1 (TXNRD1) with tumoral PD-L1 expression and ferroptosis suppression in HNSCC. Moreover, HNSCC tumors with aberrant TXNRD1 expression exhibited a lack of PD-1 response, NRF2 overexpression, and PD-L1 upregulation. TXNRD1 inhibition promoted ferroptosis in HNSCC cells with NRF2 activation and in organoid tumors derived from patients lacking a PD-1 response. Mechanistically, TXNRD1 regulated PD-L1 transcription and maintained the redox balance by binding to ribonucleotide reductase regulatory subunit M2 (RRM2). TXNRD1 expression disruption sensitized HNSCC cells to anti-PD-1-mediated Jurkat T-cell activation, promoting tumor killing through ferroptosis. Moreover, TXNRD1 inhibition through auranofin cotreatment synergized with anti-PD-1 therapy to potentiate immunotherapy-mediated ferroptosis by mediating CD8+ T-cell infiltration and downregulating PD-L1 expression. Our findings indicate that targeting TXNRD1 is a promising therapeutic strategy for improving immunotherapy outcomes in patients with HNSCC.

Targeting of FSP1 regulates iron homeostasis in drug-tolerant persister head and neck cancer cells via lipid-metabolism-driven ferroptosis

BACKGROUND

Research has demonstrated that some tumor cells can transform into drug-tolerant persisters (DTPs), which serve as a reservoir for the recurrence of the disease. The persister state in cancer cells arises due to temporary molecular reprogramming, and exploring the genetic composition and microenvironment during the development of head and neck squamous cell carcinoma (HNSCC) can enhance our comprehension of the types of cell death that HNSCC, thus identifying potential targets for innovative therapies. This project investigated lipid-metabolism-driven ferroptosis and its role in drug resistance and DTP generation in HNSCC.

METHODS

High levels of FSP1 were discovered in the tissues of patients who experienced relapse after cisplatin treatment. RNA sequencing indicated that a series of genes related to lipid metabolism were also highly expressed in tissues from these patients. Consistent results were obtained in primary DTP cells isolated from patients who experienced relapse. The Cancer Genome Atlas database confirmed this finding. This revealed that the activation of drug resistance in cancer cells is influenced by FSP1, intracellular iron homeostasis, and lipid metabolism. The regulatory roles of ferroptosis suppressor protein 1 (FSP1) in HNSCC metabolic regulation were investigated.

RESULTS

We generated human oral squamous cell carcinoma DTP cells (HNSCC cell line) to cisplatin and observed higher expression of FSP1 and lipid-metabolism-related targets in vitro. The shFSP1 blockade attenuated HNSCC-DTP cell stemness and downregulated tumor invasion and the metastatic rate. We found that cisplatin induced FSP1/ACSL4 axis expression in HNSC-DTPC cells. Finally, we evaluated the HNSCC CSC-inhibitory functions of iFSP1 (a metabolic drug and ferroptosis inducer) used for neo-adjuvant chemotherapy; this was achieved by inducing ferroptosis in a patient-derived xenograft mouse model.

CONCLUSIONS

The present findings elucidate the link between iron homeostasis, ferroptosis, and cancer metabolism in HNSCC-DTP generation and acquisition of chemoresistance. The findings may serve as a suitable model for cancer treatment testing and prediction of precision treatment outcomes. In conclusion, this study provides clinically oriented platforms for evaluating metabolism-modulating drugs (FSP1 inhibitors) and new drug candidates of drug resistance and ferroptotic biomarkers.

NADPH Oxidase Subunit CYBB Confers Chemotherapy and Ferroptosis Resistance in Mesenchymal Glioblastoma via Nrf2/SOD2 Modulation

Glioblastoma multiforme (GBM) is a highly heterogeneous disease with a mesenchymal subtype tending to exhibit more aggressive and multitherapy-resistant features. Glioblastoma stem-cells derived from mesenchymal cells are reliant on iron supply, accumulated with high reactive oxygen species (ROS), and susceptible to ferroptosis. Temozolomide (TMZ) treatment is the mainstay drug for GBM despite the rapid development of resistance in mesenchymal GBM. The main interconnection between mesenchymal features, TMZ resistance, and ferroptosis are poorly understood. Herein, we demonstrated that a subunit of NADPH oxidase, CYBB, orchestrated mesenchymal shift and promoted TMZ resistance by modulating the anti-ferroptosis circuitry Nrf2/SOD2 axis. Public transcriptomic data re-analysis found that CYBB and SOD2 were highly upregulated in the mesenchymal subtype of GBM. Accordingly, our GBM cohort confirmed a high expression of CYBB in the GBM tumor and was associated with mesenchymal features and poor clinical outcome. An in vitro study demonstrated that TMZ-resistant GBM cells displayed mesenchymal and stemness features while remaining resilient to erastin-mediated ferroptosis by activating the CYBB/Nrf2/SOD2 axis. The CYBB maintained a high ROS state to sustain the mesenchymal phenotype, TMZ resistance, and reduced erastin sensitivity. Mechanistically, CYBB interacted with Nrf2 and consequently regulated SOD2 transcription. Compensatory antioxidant SOD2 essentially protected against the deleterious effect of high ROS while attenuating ferroptosis in TMZ-resistant cells. An animal study highlighted the protective role of SOD2 to mitigate erastin-triggered ferroptosis and tolerate oxidative stress burden in mice harboring TMZ-resistant GBM cell xenografts. Therefore, CYBB captured ferroptosis resilience in mesenchymal GBM. The downstream compensatory activity of CYBB via the Nrf2/SOD2 axis is exploitable through erastin-induced ferroptosis to overcome TMZ resistance.

Synergistic disruption of BTK and BCL-2 causes apoptosis while inducing ferroptosis in double-hit lymphoma

Double-hit lymphoma (DHL) is an aggressive subset of Diffuse Large B-cell Lymphoma (DLBCL) with poor outcomes and without satisfying treatment options. BTK inhibitor monotherapy is ineffective to suppress aggressive lymphoma. Hence, combination with other potential agents is warranted. Here, we demonstrated the second generation of BTK inhibitor, zanubrutinib, and a BCL-2 inhibitor, navitoclax, worked in synergistic manner to suppress DHL. Comprehensive in silico approach by interrogating single-cell to bulk-level profiling was employed along with in vitro and in vivo validation in DHL cell lines. Ablation of BTK enhanced sensitivity to navitoclax and suppressed proliferation of DHL cells. Combination of second generation of BTK inhibitor with navitoclax synergistically suppressed DLBCL cells with higher synergy score in DHL subset. The drug combination triggered apoptosis and ferroptosis, with the latter being characterized by reactive oxygen species (ROS) accumulation, extensive lipid peroxidation, and depletion of reduced glutathione. Moreover, ablation of BTK sensitized DHL cells to ferroptosis. Mechanistically, disruption of BTK and BCL-2 triggered ferroptosis by downregulating NRF2 and HMOX1, while deactivating GPX4. Combination of zanubrutinib and navitoclax effectively suppressed tumor growth in vivo. Our data suggest that zanubrutinib and navitoclax synergistically suppressed DHL by inducing apoptosis and ferroptosis.

KDM5D Histone Demethylase Identifies Platinum-Tolerant Head and Neck Cancer Cells Vulnerable to Mitotic Catastrophe

Head and neck squamous cell carcinoma (HNSCC) is a major contributor to cancer incidence globally and is currently managed by surgical resection followed by adjuvant chemoradiotherapy. However, local recurrence is the major cause of mortality, indicating the emergence of drug-tolerant persister cells. A specific histone demethylase, namely lysine-specific demethylase 5D (KDM5D), is overexpressed in diverse types of cancers and involved in cancer cell cycle regulation. However, the role of KDM5D in the development of cisplatin-tolerant persister cells remains unexplored. Here, we demonstrated that KDM5D contributes to the development of persister cells. Aurora Kinase B (AURKB) disruption affected the vulnerability of persister cells in a mitotic catastrophe–dependent manner. Comprehensive in silico, in vitro, and in vivo experiments were performed. KDM5D expression was upregulated in HNSCC tumor cells, cancer stem cells, and cisplatin-resistant cells with biologically distinct signaling alterations. In an HNSCC cohort, high KDM5D expression was associated with a poor response to platinum treatment and early disease recurrence. KDM5D knockdown reduced the tolerance of persister cells to platinum agents and caused marked cell cycle deregulation, including the loss of DNA damage prevention, and abnormal mitosis-enhanced cell cycle arrest. By modulating mRNA levels of AURKB, KDM5D promoted the generation of platinum-tolerant persister cells in vitro, leading to the identification of the KDM5D/AURKB axis, which regulates cancer stemness and drug tolerance of HNSCC. Treatment with an AURKB inhibitor, namely barasertib, resulted in a lethal consequence of mitotic catastrophe in HNSCC persister cells. The cotreatment of cisplatin and barasertib suppressed tumor growth in the tumor mouse model. Thus, KDM5D might be involved in the development of persister cells, and AURKB disruption can overcome tolerance to platinum treatment in HNSCC.

Therapeutic targeting of hepatocellular carcinoma cells with antrocinol, a novel, dual-specificity, small-molecule inhibitor of the KRAS and ERK oncogenic signaling pathways

Until recently, sorafenib has been the only treatment approved by the U.S. Food and Drug Administration for patients with advanced hepatocellular carcinoma (HCC). Some patients, however, exhibit resistance to this treatment and subsequently experience cancer progression, recurrence, or death. Therefore, identifying a new alternative treatment for patients with little or no response to sorafenib treatment is vital. In this study, we explored the therapeutic potential and underlying molecular mechanism of antrocinol ((3aS,4R,6aS,10aR)-4-(hydroxymethyl)-7,7-dimethyldecahydro-1H-naphtho[1,8a-c]furan-1-one) in patients with HCC. The results indicated that antrocinol was more therapeutically effective than antrocin, Stivarga, and sorafenib against HCC cell lines. Antrocinol also substantially suppressed the expression of KRAS-GTP, p-MEK1/2, p-ERK1/2, and p-AKT in the Huh7 cell line. Additionally, antrocinol-induced apoptosis in the Huh7 cell line, inhibited the formation of tumorspheres, and suppressed the expression of cancer stem cell markers CD133, KLF4, CD44, OCT4, SOX2, and c-Myc. Animal studies revealed that antrocinol alone considerably suppressed tumor growth in nonobese diabetic/severe combined immunodeficient mice inoculated with Huh7 tumorspheres. It also synergistically enhanced the anticancer effect of sorafenib, resulting in enhanced suppression of tumor growth (p < 0.001) and tumorsphere formation (p < 0.001). In tumor samples resected from mice treated with antrocinol alone or in combination with sorafenib, immunohistochemical analysis revealed an increase in BAX expression and a decrease in ERK and AKT protein expression. To the best of our knowledge, this is the first report of the anti-HCC activity of antrocinol. With its higher therapeutic efficacy than that of sorafenib, antrocinol is a candidate drug for patients with HCC who demonstrate little or no response to sorafenib treatment.

Ovatodiolide and antrocin synergistically inhibit the stemness and metastatic potential of hepatocellular carcinoma via impairing ribosome biogenesis and modulating ERK/Akt-mTOR signaling axis

Activation of mitogen-activated protein kinase (MAPK) and PI3K signaling confers resistance against sorafenib, a mainstay treatment for advanced hepatocellular carcinoma (HCC). Antrocin and ovatodiolide constitute as the most potent secondary metabolites isolated from Antrodia camphorata and Anisomeles indica, respectively. Both natural compounds have recently gained a lot of attention due to their putative inhibition of MAPK and PI3K signaling in various solid cancers. However, whether their combination is effective in HCC remains unknown. Here, we investigated their effect, alone or in various combinations, on MAPK and PI3K signaling pathways in HCC cells. An array of in vitro study were used to investigate anticancer and stemness effects to treat HCC, such as cytotoxicity, drug combination index, migration, invasion, colony formation, and tumor sphere formation. Drug effect in vivo was evaluated using mouse xenograft models. In this study, antrocin and ovatodiolide synergistically inhibited the SNU387, Hep3B, Mahlavu, and Huh7 cell lines. Sequential combination treatment of Huh7 and Mahlavu with ovatodiolide followed by antrocin resulted stronger cytotoxic effect than did treatment with antrocin followed by ovatodiolide, their simultaneous administration, antrocin alone, or ovatodiolide alone. In the Huh7 and Mahlavu cell lines, ovatodiolide→antrocin significantly suppressed colony formation and proliferation as well as markedly downregulated ERK1/2, Akt, and mTOR expression. Inhibition of ERK1/2 and Akt/mTOR signaling by ovatodiolide→antrocin suppressed ribosomal biogenesis, autophagy, and cancer stem cell-like phenotypes and promoted apoptosis in Huh7 and Mahlavu cells. The sorafenib-resistant clone of Huh7 was effectively inhibited by synergistic combination of both compound in vitro. Eventually, the ovatodiolide→antrocin combination synergistically suppressed the growth of HCC xenografts. Taken together, our findings suggested that ovatodiolide→antrocin combination may represent potential therapeutic approach for patients with advanced HCC.

Targeting the SREBP-1/Hsa-Mir-497/SCAP/FASN Oncometabolic Axis Inhibits the Cancer Stem-like and Chemoresistant Phenotype of Non-Small Cell Lung Carcinoma Cells

Background: Lung cancer remains a leading cause of cancer-related death, with an annual global mortality rate of 18.4%. Despite advances in diagnostic and therapeutic technologies, non–small cell lung carcinoma (NSCLC) continues to be characterized by a poor prognosis. This may be associated with the enrichment of cancer stem cells (CSCs) and the development of chemoresistance—a double-edged challenge that continues to impede the improvement of long-term outcomes. Metabolic reprogramming is a new hallmark of cancer. Sterol regulatory element-binding proteins (SREBPs) play crucial regulatory roles in the synthesis and uptake of cholesterol, fatty acids, and phospholipids. Recent evidence has demonstrated that SREBP-1 is upregulated in several cancer types. However, its role in lung cancer remains unclear. Objective: This study investigated the role of SREBP-1 in NSCLC biology, progression, and therapeutic response and explored the therapeutic exploitability of SREBP-1 and SREBP-1-dependent oncometabolic signaling and miRNA epigenetic regulation. Methods: We analyzed SREBP-1 levels and biological functions in clinical samples and the human NSCLC cell lines H441 and A549 through shRNA-based knock down of SREBP function, cisplatin-resistant clone generation, immunohistochemical staining of clinical samples, and cell viability, sphere-formation, Western blot, and quantitative PCR assays. We conducted in-silico analysis of miRNA expression in NSCLC samples by using the Gene Expression Omnibus (GSE102286) database. Results: We demonstrated that SREBP-1 and SCAP are highly expressed in NSCLC and are positively correlated with the aggressive phenotypes of NSCLC cells. In addition, downregulation of the expression of tumor-suppressing hsa-miR-497-5p, which predictively targets SREBP-1, was observed. We also demonstrated that SREBP-1/SCAP/FASN lipogenic signaling plays a key role in CSCs-like and chemoresistant NSCLC phenotypes, especially because the fatostatin or shRNA targeting of SREBP-1 significantly suppressed the viability, cisplatin resistance, and cancer stemness of NSCLC cells and because treatment induced the expression of hsa-miR-497. Conclusion: Targeting the SREBP-1/hsa-miR-497 signaling axis is a potentially effective anticancer therapeutic strategy for NSCLC.

Role of GDF15/MAPK14 Axis in Chondrocyte Senescence as a Novel Senomorphic Agent in Osteoarthritis

Osteoarthritis (OA) is most prevalent in older individuals and exerts a heavy social and economic burden. However, an effective and noninvasive approach to OA treatment is currently not available. Chondrocyte senescence has recently been proposed as a key pathogenic mechanism in the etiology of OA. Furthermore, senescent chondrocytes (SnCCs) can release various proinflammatory cytokines, proteolytic enzymes, and other substances known as the senescence-associated secretory phenotype (SASP), allowing them to connect with surrounding cells and induce senesce. Studies have shown that the pharmacological elimination of SnCCs slows the progression of OA and promotes regeneration. Growth differentiation factor 15 (GDF15), a member of the tumor growth factor (TGF) superfamily, has recently been identified as a possible aging biomarker and has been linked to a variety of clinical conditions, including coronary artery disease, diabetes, and multiple cancer types. Thus, we obtained data from a publicly available single-cell sequencing RNA database and observed that GDF15, a critical protein in cellular senescence, is highly expressed in early OA. In addition, GDF15 is implicated in the senescence and modulation of MAPK14 in OA. Tissue and synovial fluid samples obtained from OA patients showed overexpression of GDF15. Next, we treated C20A4 cell lines with interleukin (IL)-1β with or without shGDF15 then removed the conditioned medium, and cultured C20A4 and HUVEC cell lines with the aforementioned media. We observed that C20A4 cells treated with IL-1β exhibited increased GDF15 secretion and that chondrocytes cultured with media derived from IL-1β–treated C20A4 exhibited senescence. HUVEC cell migration and tube formation were enhanced after culturing with IL-1β-treated chondrocyte media; however, decreased HUVEC cell migration and tube formation were noted in HUVEC cells cultured with GDF15-loss media. We tested the potential of inhibiting GDF15 by using a GDF15 neutralizing antibody, GDF15-nAb. GDF15-nAb exerted a similar effect, resulting in the molecular silencing of GDF15 in vivo and in vitro. Our results reveal that GDF15 is a driver of SnCCs and can contribute to OA progression by inducing angiogenesis.

Cell of Origin Based on Hans’ Algorithm as Prognostic Factor in Diffuse Large B-Cell Lymphoma: A Clinicopathologic and Survival Study

Background: Diffuse Large B-Cell Lymphoma (DLBCL) has been classified based on Cell of Origin (COO) into Germinal Center B-cell (GCB) and Non-Germinal Center B-cell (Non-GCB). The practical application of this concept by immunohistochemistry (IHC)-based subtyping with Hans’ algorithm and its role as a prognostic factor has been widely investigated with conflicting results. Moreover, the recent deeper molecular characterizations of DLBCL have been another challenges for this approach to remain as a prognostic factor. Objective: To determine the prognostic value of COO by IHC-based subtyping with Hans’ algorithm for DLBCL. Materials and Methods: This was a single-center retrospective analysis including DLBCL cases diagnosed in 2014-2019 from Dr. Sardjito Hospital, Yogyakarta, Indonesia. Hans’ algorithm with CD10, BCL6, and MUM1 were used. The two subtypes were compared in terms of clinicopathological features and 3 years overall survival. Results: Seventy patients were included in this study. Non-GCB was predominant than GCB 74.3% vs 25.7%, with the ratio of 2.8:1. No statistical difference in the clinicopathological features from both subtypes in terms of age, gender, Ann Arbor stadium, ECOG performance status, extra-nodal involvement, and LDH level. Ann Arbor stadium and ECOG showed significant prognostic value for patients outcome with multivariate analysis (OR 3.64; 95%CI 0.18-0.61; p=0.001) and (OR 2.68; 95%CI 0.11-0.77; p=0.009). Survival analysis based on COO did not show significant difference between GCB and non-GCB subtypes (log rank=0.46). Further analysis based on COO and the use of rituximab showed better OS in the two subtypes than without rituximab although not significant (log rank=0.67). Conclusion: The role of COO with Hans’ algorithm as prognostic factor in DLBCL is not confirmed in this study. Some related factors may be the addition of rituximab and the recent molecular characterization of DLBCL which covered a more subtle classification of the disease beyond GCB and non-GCB subtypes. 

Anemia in Lymphoma Patients in Indonesia: The Prevalence and Predictive Factors

Background: The burden of lymphoma is intensified with the presence of anemia. The type of anemia in lymphoma is predominantly anemia of chronic disease. Severe anemia is also often associated with advanced stages leading to poor prognosis and survival as well as a worse quality of life. Objective: In this study, we aimed to observe the incidence of anemia in lymphoma and to identify any associated clinical and laboratory factors. Methods: Data from lymphoma patients admitted between 2012 to 2018 with complete hemoglobin (Hb) levels were collected from the medical records in Dr. Sardjito Hospital, Yogyakarta, Indonesia. Clinical and laboratory parameters included were age, sex, nutritional status, Ann Arbor staging, extranodal involvement, number of extranodal sites, Lactate Dehydrogenase (LDH) level, Eastern Cooperative Oncology Group (ECOG) performance status, platelet count, absolute lymphocyte count (ALC), white blood cell count (WBC), and lymphoma prognostic score (Non-Hodgkin Lymphoma/NHL using Index Prognostic International (IPI), Hodgkin’s Lymphoma/HL using International Prognostic Score (IPS)). Statistical analysis was done to observe the difference in any parameters between patients with anemia and non-anemia. Logistic regression was employed to model the relationship between associated or predictive factors and anemia incidence. Results: Six hundred eleven (611) lymphoma patients were involved in this study, 296 (48.5%) had anemia and 314 (51.5%) did not. Anemia was more prevalent in HL (17/ 33 cases or 51.5%) than in NHL (272/ 564 cases or 48.1%). Patients with anemia frequently presented with mild anemia in 142 (48%), followed by moderate anemia in 139 (46.9%). The incidence of anemia were significantly associated with male sex, advanced Ann Arbor stage (III-IV), underweight, elevated LDH level, abnormal platelet, absolute lymphocyte counts less than 600/mm3, elevated WBC count more than 15,000/mm3, and high total prognostic score (>3). Multivariate analysis demonstrated low or elevated platelet (P=0.044; 95% CI=1.03-8.09) as an independent predictor, meanwhile lymphocytopenia as protective factor (OR=0.05; 95% CI=0.00-0.54; P=0.013). Conclusion: Anemia commonly occurs in Indonesian lymphoma patients. There is an association and increased risk to develop anemia in male, Ann Arbor stage III-IV, underweight, elevated LDH, abnormal platelet, leukocytosis, and high total prognostic score. Abnormal platelet was an independent predictive factor, and lymphocytopenia is one of the protective factor.