Inhibition of YAP by lenvatinib in endothelial cells increases blood pressure through ferroptosis

Receptor tyrosine kinase inhibition leads to regression of acral melanoma by targeting the tumor microenvironment

BACKGROUND

Acral melanoma (AM) is an aggressive melanoma variant that arises from palmar, plantar, and nail unit melanocytes. Compared to non-acral cutaneous melanoma (CM), AM is biologically distinct, has an equal incidence across genetic ancestries, typically presents in advanced stage disease, is less responsive to therapy, and has an overall worse prognosis.

METHODS

An independent analysis of published sequencing data was performed to evaluate the frequency of receptor tyrosine kinase (RTK) ligands and adapter protein gene variants and expression. To target these genetic variants, a zebrafish acral melanoma model and preclinical patient-derived xenograft (PDX) mouse models were treated with a panel of RTK inhibitors. Residual PDX tumors were evaluated for changes in proliferation, vasculature, necrosis, and ferroptosis by histology and immunohistochemistry.

RESULTS

RTK ligands and adapter proteins are frequently amplified, translocated, and/or overexpressed in AM. Dual FGFR/VEGFR inhibitors decrease acral-analogous melanocyte proliferation and migration in zebrafish, and the potent pan-FGFR/VEGFR inhibitor, Lenvatinib, uniformly induces tumor regression in AM PDX tumors but only slows tumor growth in CM models. Unlike other multi-RTK inhibitors, Lenvatinib is not directly cytotoxic to dissociated AM PDX tumor cells and instead disrupts tumor architecture and vascular networks.

CONCLUSION

Considering the great difficulty in establishing AM cell culture lines, these findings suggest that AM may be more sensitive to microenvironment perturbations than CM. In conclusion, dual FGFR/VEGFR inhibition may be a viable therapeutic strategy that targets the unique biology of AM.

Development and Validation of a Sensitive LC-MS/MS Method for Determination of Lenvatinib and Its Major Metabolites in Human Plasma and Its Application in Hepatocellular Carcinoma Patients

Lenvatinib has been demonstrated effective in advanced hepatocellular carcinoma (HCC), but the pharmacokinetic-pharmacodynamics behavior of lenvatinib and its metabolites remains unclear. To investigate the pharmacokinetic-pharmacodynamics behavior of lenvatinib and its active metabolites in advanced HCC patients, it is important to develop a simple and rapid method to analyze the exposures of lenvatinib and its metabolites in human samples. Here, we established and validated a simple and rapid method for determining lenvatinib and its three major metabolites, descyclopropyl lenvatinib (M1), O-demethyl lenvatinib hydrochloride (M2), and lenvatinib N-Oxide (M3) by liquid chromatography-tandem mass spectrometry method. Lenvatinib and its main metabolites were separated on an X-Terra RP18 column (50 × 2.1 mm, 3.5 µm) at 35°C within 3 min, and the analytes were isocratically eluted with the mobile phase of methanol-water (10:90, v/v) containing 0.1% of formic acid at a flow rate of 0.15 mL/min. The calibration range was 1-1000 ng/mL for lenvatinib, while 0.1-100 ng/mL for M1-M3 under positive electrospray ionization mode. The inter- and intra-batch precisions and accuracy were acceptable for lenvatinib and its metabolites. This method was successfully applied to measure lenvatinib and its metabolites in plasma samples from HCC patients, which provides a robust tool for pharmacokinetic-pharmacodynamics studies of lenvatinib.

Inhibition of CTLA-4 accelerates atherosclerosis in hyperlipidemic mice by modulating the Th1/Th2 balance via the NF-κB signaling pathway

Objective

Though an increased risk of atherosclerosis is associated with anti-CTLA-4 antibody therapy, the underlying mechanisms remain unclear.

Methods

C57BL/6 mice were treated with anti-cytotoxic T-lymphocyte-associated protein 4 (CTLA-4) antibody twice a week for 4 weeks, after being injected with AAV8-PCSK9 and fed a Paigen diet (PD). The proportion of aortic plaque and lipid accumulation were assessed using Oil Red O staining, while the morphology of atherosclerotic lesions was analyzed with hematoxylin and eosin staining. Collagen content was evaluated through Picrosirius Red (PSR) staining, while inflammatory cell infiltration was examined with immunofluorescence staining. CD4+ T cells secreting IFN-γ and IL-4, which represent Th1 and Th2 cells respectively, were detected by flow cytometry and real-time PCR. Protein levels of p-IκBα, IκBα, p-p65, and p65 were determined by Western blot.

Results

Inhibiting CTLA-4 exacerbated PD-induced plaque progression and promoted CD4+ T cell infiltration in the aortic root. The anti-CTLA-4 antibody promoted CD4+ T cell differentiation toward the Th1 type, as indicated by an increase in the Th1/Th2 ratio. Compared to the anti-IgG group, treatment with anti-CTLA-4 antibody significantly elevated the protein levels of p-IκBα and p-p65, as well as the mRNA levels of TNF-α, IL-6, ICAM-1, and VCAM-1. Inhibiting the NF-κB signaling pathway attenuated the overall pathological phenotype induced by the anti-CTLA-4 antibody treatment.

Conclusion

Anti-CTLA-4 treatment promotes the progression of atherosclerosis by activating NF-κB signaling and modulating the Th1/Th2 balance. Our results provide a rationale for preventing and/or treating atherosclerosis accelerated by anti-CTLA-4 antibody therapy in cancer patients.

LACTB suppresses liver cancer progression through regulation of ferroptosis

Ferroptosis, driven by iron-dependent phospholipid peroxidation, is emerging as an intrinsic cancer defense mechanism. However, the regulatory networks involved in ferroptosis remain largely unknown. Here, we found that serine beta-lactamase-like protein (LACTB) inhibits liver cancer progression by regulating ferroptosis. LACTB is downregulated in liver cancer, and the ectopic expression of LACTB markedly inhibits cell viability, colony formation, and tumour growth. LACTB knockout exerts the opposite effects. Further investigation revealed that LACTB blocks HSPA8 transcription in a p53-dependent manner, resulting in the elevation of NCOA4-mediated ferritinophagy and inhibition of SLC7A11/GSH/GPX4 signalling, thereby triggering ferroptosis and suppressing liver cancer progression. Liver cancer cells with an endogenous mutation of p53 binding site in the HSPA8 promoter exhibited increased resistance to ferroptosis inducers, and the ferroptosis-promoting effect of LACTB was significantly weakened in these mutant cells. Importantly, LACTB is identified as a downstream target of lenvatinib, and adeno-associated virus-mediated overexpression and knockdown of LACTB notably enhance and attenuate the anti-tumour efficacy of lenvatinib in vivo, respectively. Taken together, our study reveals a novel action of LACTB and provides potential therapeutic strategies for enhancing the efficacy of lenvatinib in liver cancer.

Receptor tyrosine kinase inhibition leads to regression of acral melanoma by targeting the tumor microenvironment

Acral melanoma (AM) is an aggressive melanoma variant that arises from palmar, plantar, and nail unit melanocytes. Compared to non-acral cutaneous melanoma (CM), AM is biologically distinct, has an equal incidence across genetic ancestries, typically presents in advanced stage disease, is less responsive to therapy, and has an overall worse prognosis. Independent analysis of published genomic and transcriptomic sequencing identified that receptor tyrosine kinase (RTK) ligands and adapter proteins are frequently amplified, translocated, and/or overexpressed in AM. To target these unique genetic changes, a zebrafish acral melanoma model was exposed to a panel of narrow and broad spectrum multi-RTK inhibitors, revealing that dual FGFR/VEGFR inhibitors decrease acral-analogous melanocyte proliferation and migration. The potent pan-FGFR/VEGFR inhibitor, Lenvatinib, uniformly induces tumor regression in AM patient-derived xenograft (PDX) tumors but only slows tumor growth in CM models. Unlike other multi-RTK inhibitors, Lenvatinib is not directly cytotoxic to dissociated AM PDX tumor cells and instead disrupts tumor architecture and vascular networks. Considering the great difficulty in establishing AM cell culture lines, these findings suggest that AM may be more sensitive to microenvironment perturbations than CM. In conclusion, dual FGFR/VEGFR inhibition may be a viable therapeutic strategy that targets the unique biology of AM.

Design, synthesis, and evaluation of formylpiperazine analogs of Ferrostatin-1 as novel improved ferroptosis inhibitors

In this study, a series of new formylpiperazine-derived ferroptosis inhibitors were designed and synthesized based on the structure of a known ferroptosis inhibitor, ferrostatin-1 (Fer-1). The anti-ferroptosis activity of these synthetic compounds in human umbilical vein endothelial cells (HUVECs) induced by Erastin was evaluated. It was found that some of the new compounds, especially compound 26, showed potent anti-ferroptosis activity, as evidenced by its ability to restore cell viability, reduce iron accumulation, scavenge reactive oxygen species, maintain mitochondrial membrane potential, increase GSH levels, decrease LPO and MDA content, and upregulate GPX4 expression. Moreover, compound 26 exhibited superior microsomal stability than Fer-1. The present results suggest that compound 26 is a promising lead compound for the development of new ferroptosis inhibitors for the treatment of vascular diseases.

GPX4, ferroptosis, and diseases

GPX4 (Glutathione peroxidase 4) serves as a crucial intracellular regulatory factor, participating in various physiological processes and playing a significant role in maintaining the redox homeostasis within the body. Ferroptosis, a form of iron-dependent non-apoptotic cell death, has gained considerable attention in recent years due to its involvement in multiple pathological processes. GPX4 is closely associated with ferroptosis and functions as the primary inhibitor of this process. Together, GPX4 and ferroptosis contribute to the pathophysiology of several diseases, including sepsis, nervous system diseases, ischemia reperfusion injury, cardiovascular diseases, and cancer. This review comprehensively explores the regulatory roles and impacts of GPX4 and ferroptosis in the development and progression of these diseases, with the aim of providing insights for identifying potential therapeutic strategies in the future.

Ferroptosis in age-related vascular diseases: Molecular mechanisms and innovative therapeutic strategies

Aging, an inevitable aspect of human existence, serves as one of the predominant risk factors for vascular diseases. Delving into the mystery of vascular disease's pathophysiology, the profound involvement of programmed cell death (PCD) has been extensively demonstrated. PCD is a fundamental biological process that plays a crucial role in both normal physiology and pathology, including a recently discovered form, ferroptosis. Ferroptosis is characterized by its reliance on iron and lipid peroxidation, and its significant involvement in vascular disease pathophysiology has been increasingly acknowledged. This phenomenon not only offers a promising therapeutic target but also deepens our understanding of the complex relationship between ferroptosis and age-related vascular diseases. Consequently, this article aims to thoroughly review the mechanisms that enable the effective control and inhibition of ferroptosis. It focuses on genetic and pharmacological interventions, with the goal of developing innovative therapeutic strategies to combat age-related vascular diseases.

Bisphenol A induces placental ferroptosis and fetal growth restriction via the YAP/TAZ-ferritinophagy axis

Exposure to bisphenol A (BPA) during gestation leads to fetal growth restriction (FGR), whereby the underlying mechanisms remain unknown. Here, we found that FGR patients showed higher levels of BPA in the urine, serum, and placenta; meanwhile, trophoblast ferroptosis was observed in FGR placentas, as indicated by accumulated intracellular iron, impaired antioxidant molecules, and increased lipid peroxidation products. To investigate the role of ferroptosis in placental and fetal growth, BPA stimulation was performed both in vivo and in vitro. BPA exposure during gestation was associated with FGR in mice; also, it induces ferroptosis in mouse placentas and human placental trophoblast. Pretreatment with ferroptosis inhibitor ferritin-1 (Fer-1) alleviated BPA-induced oxidative damage and cell death. Notably, BPA reduced the trophoblastic expression of Yes-associated protein (YAP) and transcriptional coactivator with PDZ-binding motif (TAZ), which regulated tissue growth and organ size. YAP or TAZ siRNA enhanced BPA-induced ferroptosis, suggesting that trophoblast ferroptosis is dependent on YAP/TAZ downregulation after BPA stimulation. Consistently, the protein levels of YAP/TAZ were also reduced in FGR placentas. Further results revealed that silencing YAP/TAZ promoted BPA-induced ferroptosis through autophagy. Pretreatment with autophagy inhibitor chloroquine (CQ) attenuated BPA-induced trophoblast ferroptosis. Ferritinophagy, an autophagic degradation of ferritin (FTH1), was observed in FGR placentas. Similarly, BPA reduced the protein level of FTH1 in placental trophoblast. Pretreatment with iron chelator desferrioxamine (DFO) and NCOA4 (an autophagy cargo receptor) siRNA weakened the ferroptosis of trophoblast after exposure to BPA, indicating that autophagy mediates ferroptosis in BPA-stimulated trophoblast by degrading ferritin. In summary, ferroptosis was featured in BPA-associated FGR and trophoblast injury; the regulation of ferroptosis involved the YAP/TAZ-autophagy-ferritin axis.

Bisphenol A induces placental ferroptosis and fetal growth restriction via the YAP/TAZ-ferritinophagy axis

Exposure to bisphenol A (BPA) during gestation leads to fetal growth restriction (FGR), whereby the underlying mechanisms remain unknown. Here, we found that FGR patients showed higher levels of BPA in the urine, serum, and placenta; meanwhile, trophoblast ferroptosis was observed in FGR placentas, as indicated by accumulated intracellular iron, impaired antioxidant molecules, and increased lipid peroxidation products. To investigate the role of ferroptosis in placental and fetal growth, BPA stimulation was performed both in vivo and in vitro. BPA exposure during gestation was associated with FGR in mice; also, it induces ferroptosis in mouse placentas and human placental trophoblast. Pretreatment with ferroptosis inhibitor ferritin-1 (Fer-1) alleviated BPA-induced oxidative damage and cell death. Notably, BPA reduced the trophoblastic expression of Yes-associated protein (YAP) and transcriptional coactivator with PDZ-binding motif (TAZ), which regulated tissue growth and organ size. YAP or TAZ siRNA enhanced BPA-induced ferroptosis, suggesting that trophoblast ferroptosis is dependent on YAP/TAZ downregulation after BPA stimulation. Consistently, the protein levels of YAP/TAZ were also reduced in FGR placentas. Further results revealed that silencing YAP/TAZ promoted BPA-induced ferroptosis through autophagy. Pretreatment with autophagy inhibitor chloroquine (CQ) attenuated BPA-induced trophoblast ferroptosis. Ferritinophagy, an autophagic degradation of ferritin (FTH1), was observed in FGR placentas. Similarly, BPA reduced the protein level of FTH1 in placental trophoblast. Pretreatment with iron chelator desferrioxamine (DFO) and NCOA4 (an autophagy cargo receptor) siRNA weakened the ferroptosis of trophoblast after exposure to BPA, indicating that autophagy mediates ferroptosis in BPA-stimulated trophoblast by degrading ferritin. In summary, ferroptosis was featured in BPA-associated FGR and trophoblast injury; the regulation of ferroptosis involved the YAP/TAZ-autophagy-ferritin axis.

G protein-coupled receptor 30 activation inhibits ferroptosis and protects chondrocytes against osteoarthritis

Background

Osteoarthritis (OA) is the most common joint disease worldwide, but its cause remains unclear. Oestrogen protects against OA, but its clinical use is limited. G protein-coupled receptor 30 (GPR30) is a receptor that binds oestrogen, and GPR30 treatment has benefitted patients with some degenerative diseases. However, its effects on OA prevention and treatment remain unclear. Moreover, several studies have found that activation of estrogen receptors exerting anti-ferroptosis effects, which plays an important role in chondrocyte survival. Therefore, this study explored the general and ferroptosis-related effects and mechanisms of GPR30 in OA.

Methods

Genome-wide RNA sequencing, western blotting, and immunohistochemistry were used to evaluate GPR30 expression and ferroptosis-related indicators in cartilage tissues from clinical patients. Next, we investigated the effects of G1 (a GPR30 receptor agonist) on the function and pathology of OA in an animal model. We also treated chondrocytes with erastin (ferroptosis agonist) plus G1, G15 (GPR30 receptor antagonist), GPR30 short hairpin RNA, or ferrostatin-1 (ferroptosis inhibitor), then measured cell viability and ferroptosis-related indices and performed proteomics analyses. Finally, western blotting and reverse transcription-polymerase chain reaction were used to assess the effects of G1 on yes-associated protein 1 (YAP1) and ferritin heavy chain 1 (FTH1) expression.

Results

GPR30 expression was lower in the OA cartilage tissues than in the normal tissues, and G1 treatment significantly improved the locomotor ability of mice. Moreover, chondrocyte cell viability significantly decreased after erastin treatment, but G1 treatment concentration-dependently mitigated this effect. Furthermore, G1 treatment decreased phosphorylated YAP1 expression, increased activated YAP1 expression, and increased FTH1 transcription and protein expression, protecting against ferroptosis.

Conclusion

GPR30 activation inhibited ferroptosis in chondrocytes by suppressing YAP1 phosphorylation, which regulates FTH1 expression.The Translational Potential of this Article: These results provide a novel potential target for therapeutic OA interventions.

The Hippo pathway in endometrial cancer: a potential therapeutic target?

Endometrial cancer, one of the most prevalent malignant cancers tumors of the female reproductive tract, has been increasing in incidence and mortality rates around the world. The Hippo pathway, one of the eight traditional human cancer signaling pathways, is an intricate signaling network that regulates cell proliferation, differentiation, and migration as well as restricting organ size in response to a range of intracellular and extracellular signals. Inhibiting the Hippo pathway results in aberrant activation of its downstream core component YAP/TAZ, which can enhance cancer cells' metabolism and maintain their stemness. Additionally, the Hippo pathway can modulate the tumor microenvironment and induce drug resistance, where tumorigenesis and tumor progression occur. However, the Hippo pathway has been little researched in endometrial cancer. Here, we aim to review how the Hippo pathway contributes to the onset, development and the potential treatment of endometrial cancer with the aim of providing new therapeutic targets.