YAP promotes autophagy and progression of gliomas via upregulating HMGB1

Autophagy: The convergence point of aging and cancer

Autophagy, a dynamic intracellular degradation system, is critical for cellular renovation and maintaining equilibrium. By eliminating damaged components and recycling essential molecules, autophagy safeguards cellular integrity and function. The versatility of the autophagy process across various biological functions enable cells to adapt and maintain homeostasis under unfavourable conditions. Disruptions in autophagy can shift a cell from a healthy state to a disease state or, conversely, support a return to health. This review delves into the multifaceted role of autophagy during aging and age-related diseases such as cancer, highlighting its significance as a unifying target with promising therapeutic implications. Cancer development is a dynamic process characterized by the acquisition of diverse survival capabilities for proliferating at different stages. This progression unfolds over time, with cancer cells exploiting autophagy to overcome encountered stress conditions during tumor development. Notably, there are several common pathways that utilize the autophagy process during aging and cancer development. This highlights the importance of autophagy as a crucial therapeutic target, holding the potential to not only impede the growth of tumor but also enhance the patient's longevity. This review aims to simplify the intricate relationship between cancer and aging, with a particular focus on the role of autophagy.

Linear ubiquitination at damaged lysosomes induces local NFKB activation and controls cell survival

Lysosomes are the major cellular organelles responsible for nutrient recycling and degradation of cellular material. Maintenance of lysosomal integrity is essential for cellular homeostasis and lysosomal membrane permeabilization (LMP) sensitizes toward cell death. Damaged lysosomes are repaired or degraded via lysophagy, during which glycans, exposed on ruptured lysosomal membranes, are recognized by galectins leading to K48- and K63-linked poly-ubiquitination (poly-Ub) of lysosomal proteins followed by recruitment of the macroautophagic/autophagic machinery and degradation. Linear (M1) poly-Ub, catalyzed by the linear ubiquitin chain assembly complex (LUBAC) E3 ligase and removed by OTULIN (OTU deubiquitinase with linear linkage specificity) exerts important functions in immune signaling and cell survival, but the role of M1 poly-Ub in lysosomal homeostasis remains unexplored. Here, we demonstrate that L-leucyl-leucine methyl ester (LLOMe)-damaged lysosomes accumulate M1 poly-Ub in an OTULIN- and K63 Ub-dependent manner. LMP-induced M1 poly-Ub at damaged lysosomes contributes to lysosome degradation, recruits the NFKB (nuclear factor kappa B) modulator IKBKG/NEMO and locally activates the inhibitor of NFKB kinase (IKK) complex to trigger NFKB activation. Inhibition of lysosomal degradation enhances LMP- and OTULIN-regulated cell death, indicating pro-survival functions of M1 poly-Ub during LMP and potentially lysophagy. Finally, we demonstrate that M1 poly-Ub also occurs at damaged lysosomes in primary mouse neurons and induced pluripotent stem cell-derived primary human dopaminergic neurons. Our results reveal novel functions of M1 poly-Ub during lysosomal homeostasis, LMP and degradation of damaged lysosomes, with important implications for NFKB signaling, inflammation and cell death.Abbreviation: ATG: autophagy related; BafA1: bafilomycin A1; CALCOCO2/NDP52: calcium binding and coiled-coil domain 2; CRISPR: clustered regularly interspaced short palindromic repeats; CHUK/IKKA: component of inhibitor of nuclear factor kappa B kinase complex; CUL4A-DDB1-WDFY1: cullin 4A-damage specific DNA binding protein 1-WD repeat and FYVE domain containing 1; DGCs: degradative compartments; DIV: days in vitro; DUB: deubiquitinase/deubiquitinating enzyme; ELDR: endo-lysosomal damage response; ESCRT: endosomal sorting complex required for transport; FBXO27: F-box protein 27; GBM: glioblastoma multiforme; IKBKB/IKKB: inhibitor of nuclear factor kappa B kinase subunit beta; IKBKG/NEMO: inhibitor of nuclear factor kappa B kinase regulatory subunit gamma; IKK: inhibitor of NFKB kinase; iPSC: induced pluripotent stem cell; KBTBD7: kelch repeat and BTB domain containing 7; KO: knockout; LAMP1: lysosomal associated membrane protein 1; LCD: lysosomal cell death; LGALS: galectin; LMP: lysosomal membrane permeabilization; LLOMe: L-leucyl-leucine methyl ester; LOP: loperamide; LUBAC: linear ubiquitin chain assembly complex; LRSAM1: leucine rich repeat and sterile alpha motif containing 1; MAP1LC3/LC3: microtubule associated protein 1 light chain 3; MTOR: mechanistic target of rapamycin kinase; MTORC1: MTOR complex 1; NBR1: NBR1 autophagy cargo receptor; NFKB/NF-κB: nuclear factor kappa B; NFKBIA/IĸBα: nuclear factor of kappa light polypeptide gene enhancer in B-cells inhibitor alpha; OPTN: optineurin; ORAS: OTULIN-related autoinflammatory syndrome; OTULIN: OTU deubiquitinase with linear linkage specificity; RING: really interesting new gene; RBR: RING-in-between-RING; PLAA: phospholipase A2 activating protein; RBCK1/HOIL-1: RANBP2-type and C3HC4-type zinc finger containing 1; RNF31/HOIP: ring finger protein 31; SHARPIN: SHANK associated RH domain interactor; SQSTM1/p62: sequestosome 1; SR-SIM: super-resolution-structured illumination microscopy; TAX1BP1: Tax1 binding protein 1; TBK1: TANK binding kinase 1; TH: tyrosine hydroxylase; TNF/TNFα: tumor necrosis factor; TNFRSF1A/TNFR1-SC: TNF receptor superfamily member 1A signaling complex; TRIM16: tripartite motif containing 16; Ub: ubiquitin; UBE2QL1: ubiquitin conjugating enzyme E2 QL1; UBXN6/UBXD1: UBX domain protein 6; VCP/p97: valosin containing protein; WIPI2: WD repeat domain, phosphoinositide interacting 2; YOD1: YOD1 deubiquitinase.

Targeting the Hippo Pathway in Breast Cancer: A Proteomic Analysis of Yes-Associated Protein Inhibition

The dysregulation of the Hippo signaling pathway leads to the aberrant activation of oncogenic YAP and TAZ, driving tumor progression. In breast cancer, this disruption promotes proliferation and metastasis. This study investigates the effects of CA3, a selective YAP inhibitor, on the proteome of triple-negative breast cancer MDA-MB-231 and luminal-A-like MCF7 cells. Proteomic changes were analyzed via nano-LC-MS/MS, while cytotoxicity, apoptosis, and autophagy were assessed through WST-1 assays, flow cytometry, and Western blot analyses. Bioinformatics tools were employed to identify enriched pathways. MDA-MB-231 cells exhibited an increased expression of DNA repair proteins (p < 0.05), indicating a compensatory response to maintain genomic stability. In contrast, MCF7 cells showed a downregulation of DNA repair factors (p < 0.005). Additionally, metabolic reprogramming was apparent in MCF7 cells (p < 0.001). Apoptosis assays revealed a rise in cell death, while cell cycle analysis indicated pronounced G1-phase arrest in MDA-MB-231 cells (p < 0.01). Moreover, autophagic suppression was particularly evident in MCF7 cells. This study, for the first time, provides evidence that breast cancer subtypes exhibit distinct dependencies on YAP-driven pathways, revealing potential therapeutic vulnerabilities. Targeting Hippo signaling alongside DNA repair in triple-negative breast cancer or combining YAP inhibition with metabolic blockade in luminal breast cancer holds significant potential to enhance treatment efficacy.

It's all downstream from here: RTK/Raf/MEK/ERK pathway resistance mechanisms in glioblastoma

BACKGROUND

The receptor tyrosine kinase (RTK)/Ras/Raf/MEK/ERK signaling pathway is one of the most tumorigenic pathways in cancer, with its hyperactivation strongly linked to the aggressive nature of glioblastoma (GBM). Although extensive research has focused on developing therapeutics targeting this pathway, clinical success remains elusive due to the emergence of resistance mechanisms.

OBJECTIVE

This review investigates how inhibition of the RTK/Ras/Raf/MEK/ERK pathway alters transcription factors, contributing to acquired resistance mechanisms in GBM. It also highlights the critical role of transcription factor dysregulation in therapeutic resistance.

METHODS & RESULTS

Findings from key studies on the RTK/Ras/Raf/MEK/ERK pathway in GBM were synthesized to explore the role of transcription factor dysregulation in resistance to targeted therapies, radiation, and chemotherapy. The review highlights that transcription factors undergo significant dysregulation following RTK/Ras/Raf/MEK/ERK pathway inhibition, contributing to therapeutic resistance.

CONCLUSION

Transcription factors are promising targets for overcoming treatment resistance in GBM, with cotreatment strategies combining RTK/Ras/Raf/MEK/ERK pathway inhibitors and transcription factor-targeted therapies presenting a novel approach. Despite the challenges of targeting complex structures and interactions, advancements in drug development and precision technologies hold great potential. Continued research is essential to refine these strategies and improve outcomes for GBM and other aggressive cancers.

Baicalin and baicalein against myocardial ischemia-reperfusion injury: A review of the current documents

Myocardial ischemia-reperfusion injury (MIRI) is a significant challenge in the treatment of ischemic heart disease (IHD), arising as a complication from reperfusion therapies designed to restore blood flow after an ischemic event. Despite the availability of various therapeutic strategies, finding an effective treatment for MIRI remains difficult. Baicalin and its aglycone form (baicalein), natural compounds derived from the Chinese skullcap plant (Scutellaria baicalensis), have shown promise due to their antioxidant, anti-inflammatory, and cardioprotective properties. This review aims to explore the potential of baicalin and baicalein as treatments for MIRI, with a focus on their molecular and cellular level effects. These natural agents can decrease oxidative stress by promoting antioxidant enzymes and decreasing harmful oxidative substances that damage cardiac cells. They also exert anti-inflammatory effects by blocking specific pathways that trigger the release of inflammatory mediators. Additionally, they also improve heart cell survival, infarct region, and overall cardiac function by inhibiting key signaling pathways involved in cell death. Research in both animal and cell models suggests that these flavonoids, especially baicalin, can restore cardiac health following MIRI, improving cardiac performance, and reducing cardiac damage. These findings underscore the potential of baicalin and baicalein as therapeutic options for MIRI. However, further research and clinical trials are necessary to elucidate their mechanisms fully and to develop baicalin into a viable treatment.

Navigating Glioma Complexity: The Role of Abnormal Signaling Pathways in Shaping Future Therapies

Gliomas are a type of highly heterogeneous and invasive central nervous system tumor. Traditional treatment methods have limited efficacy, and the prognosis for patients remains poor. Recent studies have revealed the crucial roles of several abnormal signaling pathways in the pathogenesis of gliomas, including the Receptor Tyrosine Kinase/Rat Sarcoma Virus Oncogene/Phosphatidylinositol-3-Kinase (RTK/RAS/PI3K) pathway, the Wingless-Related Integration Site/β-Catenin (Wnt/β-Catenin) pathway, the Hippo/YAP (Hippo/Yes-associated protein) pathway, and the Slit/Robo (Slit Guidance Ligands/Roundabout) signaling pathway. These pathways play extremely vital roles in tumor proliferation, invasion, and treatment resistance. This article comprehensively and systematically reviews the molecular mechanisms of these signaling pathways, deeply summarizing the research progress of various treatment strategies, including targeted inhibitors, gene therapy, and nanomedicine against them. Moreover, the combination of targeted therapy and personalized treatment regimens is expected to overcome the current treatment bottleneck and provide a more favorable survival prognosis for glioblastoma patients.

Autophagy in brain tumors: molecular mechanisms, challenges, and therapeutic opportunities

Autophagy is responsible for maintaining cellular balance and ensuring survival. Autophagy plays a crucial role in the development of diseases, particularly human cancers, with actions that can either promote survival or induce cell death. However, brain tumors contribute to high levels of both mortality and morbidity globally, with resistance to treatments being acquired due to genetic mutations and dysregulation of molecular mechanisms, among other factors. Hence, having knowledge of the role of molecular processes in the advancement of brain tumors is enlightening, and the current review specifically examines the role of autophagy. The discussion would focus on the molecular pathways that control autophagy in brain tumors, and its dual role as a tumor suppressor and a supporter of tumor survival. Autophagy can control the advancement of different types of brain tumors like glioblastoma, glioma, and ependymoma, demonstrating its potential for treatment. Autophagy mechanisms can influence metastasis and drug resistance in glioblastoma, and there is a complex interplay between autophagy and cellular responses to stress like hypoxia and starvation. Autophagy can inhibit the growth of brain tumors by promoting apoptosis. Hence, focusing on autophagy could offer fresh perspectives on creating successful treatments.

A Role for the Hippo/YAP1 Pathway in the Regulation of In Vitro Vasculogenic Mimicry in Glioblastoma Cells

The Hippo pathway plays a tumorigenic role in highly angiogenic glioblastoma (GBM), whereas little is known about clinically relevant Hippo pathway inhibitors' ability to target adaptive mechanisms involved in GBM chemoresistance. Their molecular impact was investigated here in vitro against an alternative process to tumour angiogenesis termed vasculogenic mimicry (VM) in GBM-derived cell models. In silico analysis of the downstream Hippo signalling members YAP1, TAZ and TEAD1 transcript levels in low-grade glioblastoma (LGG) and GBM tumour tissues was performed using GEPIA. TAZ transcript levels did not differ between the healthy and tumour tissues data analysed. In contrast, YAP1 transcript levels were elevated in GBM tissues, whereas TEAD1 levels were high in both LGG and GBM. All three Hippo pathway inhibitors tested, GNE7883, VT107 and IAG933 effectively inhibited U87 and U251 cell migration and in vitro VM as assessed on Cultrex matrix. YAP1 gene and protein expression were induced upon VM, and its translocation to the nucleus was inhibited by the Hippo pathway inhibitors tested. SiRNA-mediated transient silencing of YAP1 repressed cell migration, VM formation and CTGF and Cyr61 transcription. In conclusion, targeting of VM using Hippo pathway inhibitors could help circumvent GBM chemoresistance and effectively complement other brain cancer treatments.

The neglected burden of chronic hypoxia on the resistance of glioblastoma multiforme to first-line therapies

Glioblastoma multiforme (GBM) is the most common adult primary brain tumor. The standard of care involves maximal surgery followed by radiotherapy and concomitant chemotherapy with temozolomide (TMZ), in addition to adjuvant TMZ. However, the recurrence rate of GBM within 1-2 years post-diagnosis is still elevated and has been attributed to the accumulation of multiple factors including the heterogeneity of GBM, genomic instability, angiogenesis, and chronic tumor hypoxia. Tumor hypoxia activates downstream signaling pathways involved in the adaptation of GBM to the newly oxygen-deprived environment, thereby contributing to the resistance and recurrence phenomena, despite the multimodal therapeutic approach used to eradicate the tumor. Therefore, in this review, we will focus on the development and implication of chronic or limited-diffusion hypoxia in tumor persistence through genetic and epigenetic modifications. Then, we will detail the hypoxia-induced activation of vital biological pathways and mechanisms that contribute to GBM resistance. Finally, we will discuss a proteomics-based approach to encourage the implication of personalized GBM treatments based on a hypoxia signature.

PPM1G promotes autophagy and progression of pancreatic cancer via upregulating HMGB1

Pancreatic cancer remains one of the most aggressive and lethal malignancies worldwide, with a dismal 5-year relative survival rates of only 12%. Therefore, it is urgent to discover the key molecular markers to improve the therapeutic outcomes in pancreatic cancer. Herein, we first demonstrated that PPM1G is upregulated in pancreatic cancer and that PPM1G depletion decreases pancreatic cancer cell growth in vitro and in vivo. High PPM1G expression was linked to short overall survival of pancreatic cancer patients, which was further validated in the TCGA database. Moreover, by detecting Beclin 1, LC3-II, and SQSTM1/p62 expressions and observing autolysosome under transmission electron microscope, we discovered that PPM1G is a novel positive regulator of macroautophagy/autophagy. Furthermore, by using immunoprecipitation-mass spectrometry (IP-MS) analysis and following systemic molecular biology experiment, we demonstrated PPM1G promotes the autophagy and proliferation of pancreatic cancer by directly upregulating HMGB1. Additionally, patients with both high PPM1G and high HMGB1 exhibited poorer prognosis in our cohort. This study preliminarily investigated the possibility of PPM1G as a potential therapeutic target and prognostic biomarker in pancreatic cancer patients.

Early anti-inflammatory polarization of macrophages ameliorates post-surgical inflammation and osseointegration around titanium implants in mice

Dental implants are considered a superior option for the replacement of missing teeth. However, the invasive nature of the surgical procedure often results in significant postoperative inflammation, and the prolonged healing period of 3-6 months presents a notable disadvantage. High mobility group box 1 (HMGB1) is a critical mediator of acute inflammation following surgical injury, which can hinder the onset of osseointegration. This study aims to examine whether the inhibition of HMGB1 can mitigate acute inflammation and subsequently enhance osseointegration. The findings indicate that HMGB1 inhibition markedly reduces inflammation and promotes bone repair in murine models. Further in vitro investigations into the regulatory mechanisms of HMGB1 in macrophages reveal its role in increasing Yes-associated protein (YAP) activity, which contributes to pro-inflammatory polarization. Additionally, conditioned media derived from macrophages influenced by HMGB1 significantly impair the migratory and osteogenic capabilities of bone marrow-derived mesenchymal stem cells, which are essential for bone regeneration. In vivo experiments further validate that the administration of exogenous HMGB1 exacerbates postoperative acute inflammation and obstructs osseointegration. The study concludes that inhibiting HMGB1 fosters an anti-inflammatory polarization of macrophages, leading to diminished postoperative acute inflammation and expedited osseointegration around dental implants in mice.

Ferroptosis in glioma therapy: advancements in sensitizing strategies and the complex tumor-promoting roles

Ferroptosis, an iron-dependent form of non-apoptotic regulated cell death, is induced by the accumulation of lipid peroxides on cellular membranes. Over the past decade, ferroptosis has emerged as a crucial process implicated in various physiological and pathological systems. Positioned as an alternative modality of cell death, ferroptosis holds promise for eliminating cancer cells that have developed resistance to apoptosis induced by conventional therapeutics. This has led to a growing interest in leveraging ferroptosis for cancer therapy across diverse malignancies. Gliomas are tumors arising from glial or precursor cells, with glioblastoma (GBM) being the most common malignant primary brain tumor that is associated with a dismal prognosis. This review provides a summary of recent advancements in the exploration of ferroptosis-sensitizing methods, with a specific focus on their potential application in enhancing the treatment of gliomas. In addition to summarizing the therapeutic potential, this review also discusses the intricate interplay of ferroptosis and its potential tumor-promoting roles within gliomas. Recognizing these dual roles is essential, as they could potentially complicate the therapeutic benefits of ferroptosis. Exploring strategies aimed at circumventing these tumor-promoting roles could enhance the overall therapeutic efficacy of ferroptosis in the context of glioma treatment.

Clinical Significance of HMGB1 and Autophagy-Related Genes in Sinonasal Inverted Papilloma

OBJECTIVES

Sinonasal inverted papilloma (SNIP) is a noncancerous tumor that develops in the mucous membrane of the nasal sinuses. Many malignancies are tightly linked to autophagy, an intracellular self-degradation mechanism. HMGB1 has demonstrated its ability to modulate autophagy in many pathological conditions. This work investigates how HMGB1 and other genes involved in autophagy contribute to SNIP.

MATERIAL AND METHODS

The study included 45 patients with SNIP and a control group consisting of 28 individuals. In each group, qPCR was employed to examine the mRNA expression levels of genes correlated with autophagy and HMGB1. HMGB1 and genes associated with autophagy were examined for protein expression levels via Western Blot and immunohistochemical staining assays. At the same time, the association between HMGB1 and genes involved in autophagy was discovered through correlation analysis. Furthermore, Krouse staging was utilized for investigating the expression levels of HMGB1 and other autophagy-related genes at various stages in clinically staged SNIP patients.

RESULTS

LC3B, ATG5, and Beclin1 autophagy-related genes and HMGB1 were substantially expressed in SNIP. Additionally, there was a positive correlation between HMGB1 and these genes. During various phases of SNIP, the levels of HMGB1 expression and autophagy-related genes were notably elevated at stage T4 compared with stage T2.

CONCLUSION

Clinical staging in SNIP is correlated with HMGB1 expression in conjunction with autophagy-related genes LC3B, ATG5, and Beclin1, suggesting the possibility of novel prognostic indicators.

LEVEL OF EVIDENCE

NA Laryngoscope, 134:3941-3946, 2024.

Hernandonine-mediated autophagic cell death in hepatocellular carcinoma: Interplay of p53 and YAP signaling pathways

Hepatocellular carcinoma (HCC), the primary form of liver cancer, is the third leading cause of cancer-related death globally. Hernandonine is a natural alkaloid derived from Hernandia nymphaeifolia that has been shown to exert various biological functions. In a previous study, hernandonine was shown to suppress the proliferation of several solid tumor cell lines without affecting normal human cell lines. However, little is known about the effect of hernandonine on HCC. Therefore, this study aimed to investigate the effect and mechanism of hernandonine on HCC in relation to autophagy. We found that hernandonine inhibited HCC cell growth in vitro and in vivo. In addition, hernandonine elicited autophagic cell death and DNA damage in HCC cells. RNA-seq analysis revealed that hernandonine upregulated p53 and Hippo signaling pathway-related genes in HCC cells. Small RNA interference of p53 resulted in hernandonine-induced autophagic cell death attenuation. However, inhibition of YAP sensitized HCC cells to hernandonine by increasing the autophagy induction. This is the first study to illustrate the complex involvement of p53 and YAP in the hernandonine-induced autophagic cell death in human HCC cells. Our findings provide novel evidence for the potential of hernandonine as a therapeutic agent for HCC treatment.

HMGB1 regulates autophagy of placental trophoblast through ERK signaling pathway†

OBJECTIVE

The purpose of this study is to investigate the role of high mobility group protein B1 (HMGB1) in placental development and fetal growth.

METHODS

We employed the Cre-loxP recombination system to establish a placenta-specific HMGB1 knockout mouse model. Breeding HMGB1flox/flox mice with Elf5-Cre mice facilitated the knockout, leveraging Elf5 expression in extra-embryonic ectoderm, ectoplacental cone, and trophoblast giant cells at 12.5 days of embryonic development. The primary goal of this model was to elucidate the molecular mechanism of HMGB1 in placental development, assessing parameters such as placental weight, fetal weight, and bone development. Additionally, we utilized lentiviral interference and overexpression of HMGB1 in human trophoblast cells to further investigate HMGB1's functional role.

RESULTS

Our findings indicate that the HMGB1flox/floxElf5cre/+ mouse displays fetal growth restriction, characterized by decreased placental and fetal weight and impaired bone development. The absence of HMGB1 inhibits autophagosome formation, impairs lysosomal degradation, and disrupts autophagic flux. Depletion of HMGB1 in human trophoblast cells also suppresses cell viability, proliferation, migration, and invasion by inhibiting the ERK signaling pathway. Overexpression of HMGB1 observed the opposite phenotypes.

CONCLUSIONS

HMGB1 participates in the regulation of autophagy through the ERK signaling pathway and affects placental development.

Role of renin angiotensin system inhibitors and metformin in Glioblastoma Therapy: a review

Glioblastoma multiforme (GBM) is a highly aggressive and incurable disease accounting for about 10,000 deaths in the USA each year. Despite the current treatment approach which includes surgery with chemotherapy and radiation therapy, there remains a high prevalence of recurrence. Notable improvements have been observed in persons receiving concurrent antihypertensive drugs such as renin angiotensin inhibitors (RAS) or the antidiabetic drug metformin with standard therapy. Anti-tumoral effects of RAS inhibitors and metformin have been observed in in vitro and in vivo studies. Although clinical trials have shown mixed results, the potential for the use of RAS inhibitors and metformin as adjuvant GBM therapy remains promising. Nevertheless, evidence suggest that these drugs exert multimodal antitumor actions; by particularly targeting several cancer hallmarks. In this review, we highlight the results of clinical studies using multidrug cocktails containing RAS inhibitors and or metformin added to standard therapy for GBM. In addition, we highlight the possible molecular mechanisms by which these repurposed drugs with an excellent safety profile might elicit their anti-tumoral effects. RAS inhibition elicits anti-inflammatory, anti-angiogenic, and immune sensitivity effects in GBM. However, metformin promotes anti-migratory, anti-proliferative and pro-apoptotic effects mainly through the activation of AMP-activated protein kinase. Also, we discussed metformin's potential in targeting both GBM cells as well as GBM associated-stem cells. Finally, we summarize a few drug interactions that may cause an additive or antagonistic effect that may lead to adverse effects and influence treatment outcome.

Targeting CAMK2N1/CAMK2 inhibits invasion, migration and angiogenesis of non-small cell lung cancer by promoting autophagy and apoptosis via AKT/mTOR signaling pathway

Deregulation of calcium/calmodulin-dependent protein kinase II (CAMK2) inhibitor 1 (CAMK2N1) has been reported to be associated with the development of several malignancies. To date, there have been few studies on the role of CAMK2N1 in lung cancer. This study aimed to investigate the relationship between CAMK2N1 and the progression of non-small cell lung cancer (NSCLC). Methodological quality was assessed using the ARRIVE guidelines. CAMK2N1 was expressed at low levels in NSCLC tissues. Overexpression of CAMK2N1 in NSCLC cell lines resulted in changes such as proliferation inhibition, metastasis inhibition, autophagy increase, and apoptosis. Mechanistic studies revealed the regulatory role of CAMK2N1/CAMK2 in AKT/mTOR signaling. Upregulation of CAMK2N1 decreased the expression levels of phosphorylated calmodulin kinase 2 (p-CaMK2), phosphorylated Akt (p-Akt), and phosphorylated-mTOR (p-mTOR). In contrast, CAMK2 overexpression increased p-AKT and p-mTOR levels. Inhibition of autophagy or activation of AKT signaling reduced CAMK2N1-mediated tumor suppression. The tumorigenic ability of CAMK2N1 overexpressing cells significantly diminished in nude mice. In conclusion, this study demonstrated the cancer suppressive function of CAMK2N1 in NSCLC and showed that CAMK2N1/CAMK2 exerted anti-cancer effects by inhibiting the AKT/mTOR signaling pathway to promote autophagy.

Circ_0104652 Promotes the Proliferation and Migration of ox-LDL-Stimulated Vascular Smooth Muscle Cells via Stabilizing ADAMTS7 and HMGB1

BACKGROUND

Atherosclerosis (AS) stands as the primary contributor to cardiovascular disease, a pervasive global health concern. Extensive research has underscored the pivotal role of circular RNAs (circRNAs) in cardiovascular disease development. However, the specific functions of numerous circRNAs in AS remain poorly understood.

METHODS

Quantitative real-time PCR analysis revealed a significant upregulation of circ_0104652 in oxidized low-density lipoprotein (ox-LDL)-induced vascular smooth muscle cells (VSMCs). Loss-of-function experiments were subsequently employed to assess the impact of circ_0104652 on ox-LDL-induced VSMCs.

RESULTS

Silencing circ_0104652 was found to impede the proliferation and migration while promoting the apoptosis of ox-LDL-stimulated VSMCs. Mechanistic assays unveiled that circ_0104652 stabilized ADAM metallopeptidase with thrombospondin type 1 motif 7 (ADAMTS7) and high mobility group box 1 (HMGB1) by recruiting eukaryotic translation initiation factor 4A3 (EIF4A3) protein. Rescue assays further confirmed that circ_0104652 exerted its influence on ox-LDL-induced VSMC proliferation through modulation of ADAMTS7 and HMGB1.

CONCLUSIONS

This study elucidates the role of the circ_0104652/EIF4A3/ADAMTS7/HMGB1 axis in ox-LDL-stimulated VSMCs, providing valuable insights into the intricate mechanisms involved.

Feedback loop between hypoxia and energy metabolic reprogramming aggravates the radioresistance of cancer cells

Radiotherapy is one of the mainstream approaches for cancer treatment, although the clinical outcomes are limited due to the radioresistance of tumor cells. Hypoxia and metabolic reprogramming are the hallmarks of tumor initiation and progression and are closely linked to radioresistance. Inside a tumor, the rate of angiogenesis lags behind cell proliferation, and the underdevelopment and abnormal functions of blood vessels in some loci result in oxygen deficiency in cancer cells, i.e., hypoxia. This prevents radiation from effectively eliminating the hypoxic cancer cells. Cancer cells switch to glycolysis as the main source of energy, a phenomenon known as the Warburg effect, to sustain their rapid proliferation rates. Therefore, pathways involved in metabolic reprogramming and hypoxia-induced radioresistance are promising intervention targets for cancer treatment. In this review, we discussed the mechanisms and pathways underlying radioresistance due to hypoxia and metabolic reprogramming in detail, including DNA repair, role of cancer stem cells, oxidative stress relief, autophagy regulation, angiogenesis and immune escape. In addition, we proposed the existence of a feedback loop between energy metabolic reprogramming and hypoxia, which is associated with the development and exacerbation of radioresistance in tumors. Simultaneous blockade of this feedback loop and other tumor-specific targets can be an effective approach to overcome radioresistance of cancer cells. This comprehensive overview provides new insights into the mechanisms underlying tumor radiosensitivity and progression.

Gfi-1 modulates HMGB1-Mediated autophagy to overcome oxaliplatin resistance in colorectal cancer

Background

Resistance to oxaliplatin (L-OHP) is a major barrier in the treatment of colorectal cancer (CRC). Autophagy is the main cause of L-OHP tolerance in CRC cells.

Method

The human colon cancer cell lines HCT116 and SW480 were treated with L-OHP to obtain the drug-resistant cell lines HCT116/L-OHP and SW480/L-OHP, respectively. To probe the relationship between autophagy and L-OHP tolerance of growth factor independent 1 (Gfi-1) and high-mobility group protein 1 (HMGB1) in CRC cells, gene knockout or overexpression was performed, and Western blotting was used to determine the levels of drug tolerance interrelated proteins. Transwell and CCK-8 assays were employed to analyze the proliferation of cancer cells. Immunofluorescence detection of LC3 reflected autophagy levels. Finally, the relationship between Gfi-1 and HMGB1 was detected by chromatin immunoprecipitation (ChIP).

Result

Compared to normal CRC cells, L-OHP-tolerant CRC cells exhibited greater autophagy (8.2 times greater in HCT116/L-OHP cells and 7.4 times greater in SW480/L-OHP cells). In addition, we detected low levels of Gfi-1 (0.6-fold for HCT116/L-OHP cells and 0.4-fold for SW480/L-OHP cells), and OE-Gfi-1 decreased HMGB1 levels (0.6-fold for HCT116/L-OHP + OE-Gfi-1 cells and 0.5-fold for SW480/L-OHP + OE-Gfi-1 cells). The inhibition of Gfi-1 further enhanced cell viability (1.7 times in HCT116+sh-Gfi-1 cells and 1.2 times in SW480+sh-Gfi-1 cells) and invasion (1.8 times in HCT116+sh-Gfi-1 cells and 2.1 times in SW480+sh-Gfi-1 cells) in CRC cells, thus promoting oxaliplatin resistance in these cells. The autophagy inhibitor 3-MA reversed the above effects. Furthermore, we noted that Gfi-1 can restrain HMGB1 expression by binding to its promoter (0.5 times in HCT116+OE-Gfi-1 cells and 0.5 times in SW480+OE-Gfi-1 cells). The inhibitory influence of 3-MA on HMGB1 reversed the influence of Gfi-1 on autophagy and malignant progression in CRC cells.

Conclusion

Our study suggested that Gfi-1 inhibited HMGB1 to reduce CRC autophagy levels, increasing CRC sensitivity to L-OHP.

LncRNA AA465934 Improves Podocyte Injury by Promoting Tristetraprolin-Mediated HMGB1 DownRegulation in Diabetic Nephropathy

Although LncRNA AA465934 expression is reduced in high glucose (HG)-treated podocytes, its role in HG-mediated podocyte injury and diabetic nephropathy (DN) remains unknown. Herein, we investigated the role of AA465934 in HG-mediated podocyte injury and DN using a spontaneous type II diabetic nephropathy (T2DN) model. The model was created by injecting AA465934 overexpressed adeno-associated virus (AAV) or control into mice. The levels of renal function, proteinuria, renal structural lesions, and podocyte apoptosis were then examined. Furthermore, AA465934 and autophagy levels, as well as tristetraprolin (TTP) and high mobility group box 1 (HMGB1) expression changes were detected. We also observed podocyte injury and the binding ability of TTP to E3 ligase proviral insertion in murine lymphomas 2 (PIM2), AA465934, or HMGB1. According to the results, AA465934 improved DN progression and podocyte damage in T2DN mice. In addition, AA465934 bound to TTP and inhibited its degradation by blocking TTP-PIM2 binding. Notably, TTP knock-down blocked the ameliorating effects of AA465934 and TTP bound HMGB1 mRNA, reducing its expression. Overexpression of HMGB1 inhibited the ability of AA465934 and TTP to improve podocyte injury. Furthermore, AA465934 bound TTP, inhibiting TTP-PIM2 binding, thereby suppressing TTP degradation, downregulating HMGB1, and reversing autophagy downregulation, ultimately alleviating HG-mediated podocyte injury and DN. Based on these findings, we deduced that the AA465934/TTP/HMGB1/autophagy axis could be a therapeutic avenue for managing podocyte injury and DN.

Oncolytic Newcastle disease virus induced degradation of YAP through E3 ubiquitin ligase PRKN to exacerbate ferroptosis in tumor cells

Ferroptosis, a form of programmed cell death characterized by iron-dependent lipid peroxidation, has recently gained considerable attention in the field of cancer therapy. There is significant crosstalk between ferroptosis and several classical signaling pathways, such as the Hippo pathway, which suppresses abnormal growth and is frequently aberrant in tumor tissues. Yes-associated protein 1 (YAP), the core effector molecule of the Hippo pathway, is abnormally expressed and activated in a variety of malignant tumor tissues. We previously proved that the oncolytic Newcastle disease virus (NDV) activated ferroptosis to kill tumor cells. NDV has been used in tumor therapy; however, its oncolytic mechanism is not completely understood. In this study, we demonstrated that NDV exacerbated ferroptosis in tumor cells by inducing ubiquitin-mediated degradation of YAP at Lys90 through E3 ubiquitin ligase parkin (PRKN). Blocking YAP degradation suppressed NDV-induced ferroptosis by suppressing the expression of Zrt/Irt-like protein 14 (ZIP14), a metal ion transporter that regulates iron uptake. These findings demonstrate that NDV exacerbated ferroptosis in tumor cells by inducing YAP degradation. Our study provides new insights into the mechanism of NDV-induced ferroptosis and highlights the critical role that oncolytic viruses play in the treatment of drug-resistant cancers.IMPORTANCEThe oncolytic Newcastle disease virus (NDV) is being developed for use in cancer treatment; however, its oncolytic mechanism is still not completely understood. The Hippo pathway, which is a tumor suppressor pathway, is frequently dysregulated in tumor tissues due to aberrant yes-associated protein 1 (YAP) activation. In this study, we have demonstrated that NDV degrades YAP to induce ferroptosis and promote virus replication in tumor cells. Notably, NDV was found to induce ubiquitin-mediated degradation of YAP at Lys90 through E3 ubiquitin ligase parkin (PRKN). Our study reveals a new mechanism by which NDV induces ferroptosis and provides new insights into NDV as an oncolytic agent for cancer treatment.

IGF2BP2 modulates autophagy and serves as a prognostic marker in glioma

Glioma, a malignant brain tumor originating from neural glial cells, presents significant treatment challenges. However, the underlying mechanisms of glioma development are not fully understood, and effective targets are lacking. This study provides insights into the role of insulin-like growth factor 2 messenger RNA-binding protein 2 (IGF2BP2) in glioma progression and its therapeutic potential. Our analysis illustrated that elevated IGF2BP2 expression associated with significantly shorter survival among patients with low-grade glioma (LGG) in The Cancer Genome Atlas (TCGA) database. IGF2BP2 depletion led to compromised cell viability, G0/G1 phase arrest, and reduced colony-formation ability. Furthermore, ultrastructural analysis and mCherry-GFP-LC3 reporter assay revealed an increased abundance of autophagosomes upon IGF2BP2 knockdown. Western blot analysis corroborated these findings by showing reduced p62 levels coupled with increased LC3-ІІ/LC3-I ratio upon IGF2BP2 knockdown. A multicolor immunohistochemistry assay demonstrated the positive correlation between IGF2BP2 and p62 expression in glioma patient samples. Additionally, our analysis suggested a link between IGF2BP2 expression and drug-resistant markers in TCGA-LGG samples, and Cell Counting Kit-8 cell viability assay revealed that knockdown of IGF2BP2 sensitized cells to temozolomide treatment. This comprehensive exploration unveils the role of IGF2BP2 in glioma progression, shedding light on autophagy modulation and chemosensitization strategies for glioma therapy.

HMGB1 in the interplay between autophagy and apoptosis in cancer

Lysosome-mediated autophagy and caspase-dependent apoptosis are dynamic processes that maintain cellular homeostasis, ensuring cell health and functionality. The intricate interplay and reciprocal regulation between autophagy and apoptosis are implicated in various human diseases, including cancer. High-mobility group box 1 (HMGB1), a nonhistone chromosomal protein, plays a pivotal role in coordinating autophagy and apoptosis levels during tumor initiation, progression, and therapy. The regulation of autophagy machinery and the apoptosis pathway by HMGB1 is influenced by various factors, including the protein's subcellular localization, oxidative state, and interactions with binding partners. In this narrative review, we provide a comprehensive overview of the structure and function of HMGB1, with a specific focus on the interplay between autophagic degradation and apoptotic death in tumorigenesis and cancer therapy. Gaining a comprehensive understanding of the significance of HMGB1 as a biomarker and its potential as a therapeutic target in tumor diseases is crucial for advancing our knowledge of cell survival and cell death.

Role of YAP Signaling in Regulation of Programmed Cell Death and Drug Resistance in Cancer

Although recent advances in cancer treatment significantly improved the prognosis of patients, drug resistance remains a major challenge. Targeting programmed cell death is a major approach of antitumor drug development. Deregulation of programmed cell death (PCD) contributes to resistance to a variety of cancer therapeutics. Yes-associated protein (YAP) and its paralog TAZ, the main downstream effectors of the Hippo pathway, are aberrantly activated in a variety of human malignancies. The Hippo-YAP pathway, which was originally identified in Drosophila, is well conserved in humans and plays a defining role in regulation of cell fate, tissue growth and regeneration. Activation of YAP signaling has emerged as a key mechanism involved in promoting cancer cell proliferation, metastasis, and drug resistance. Understanding the role of YAP/TAZ signaling network in PCD and drug resistance could facilitate the development of effective strategies for cancer therapeutics.

Starvation insult induces the translocation of high mobility group box 1 to cytosolic compartments in glioma

High mobility group box 1 (HMGB1) is a highly conserved and ubiquitous nuclear protein in eukaryotic cells. In response to stress, it transfers from the nucleus to the cytoplasm and finally, to the extracellular matrix, participating in inflammation and carcinogenesis. Increased HMGB1 protein levels are frequently associated with the reduced survival of patients with glioma. HMGB1 plays contextual roles depending on its subcellular localization. However, the mechanisms underlying its subcellular localization and secretion remain unclear. In the present study, the subcellular localization and secretion of HMGB1 in starved glioma cells were investigated using immunofluorescence microscopy, enzyme‑linked immunosorbent assay, subcellular fractionation, western blotting and immunoelectron microscopy. The results demonstrated that starvation induced HMGB1 translocation from the nucleus to the cytoplasm and finally, to the extracellular milieu in glioma cells. HMGB1 was localized in the mitochondria, endoplasmic reticulum (ER), peroxisomes, autophagosomes, lysosomes, endosomes and the cytoskeleton. Immunoelectron microscopy confirmed that HMGB1 was present within or around cytosolic compartments. Subcellular fractionation further demonstrated that HMGB1 transferred to membrane‑bound compartments. In addition, HMGB1 was localized to specific contact areas between the ER and mitochondria, known as mitochondria‑associated membranes. On the whole, the results of the present study suggest that starvation induces HMGB1 secretion, which can be inhibited through the suppression of autophagy. Starvation insult induces HMGB1 translocation to the cytosolic compartments of glioma cells, and autophagy may be involved in the extracellular secretion of HMGB1 in starved glioma cells.

Histone lactylation promotes cell proliferation, migration and invasion through targeting HMGB1 in endometriosis

Endometriosis is defined as a condition with endometrium-like tissues migrating outside of the pelvic cavity. However, the mechanism of endometriosis is still unclear. Lactate can be covalently modified to lysine residues of histones and other proteins, which is called lactylation. The results showed that the higher level of lactate and lactate dehydrogenase A enhanced the histone H3 lysine 18 lactylation (H3K18lac) in ectopic endometrial tissues and ectopic endometrial stromal cells than that in normal endometrial tissues and normal endometrial stromal cells. Lactate promoted cell proliferation, migration, and invasion in endometriosis. Mechanistically, lactate induced H3K18lac to promote the expression of high-mobility group box 1 (HMGB1) in endometriosis, and HMGB1 knockdown significantly reduced the cell proliferation, migration, and invasion of the lactate-treated cells through the phosphorylation of AKT. In conclusion, lactate could induce histone lactylation to promote endometriosis progression by upregulating the expression of HMGB1, which may provide a novel target for the prevention and treatment of endometriosis.

Chloroquine inhibited Helicobacter pylori-related gastric carcinogenesis by YAP-β-catenin-autophagy axis

YAP participates in autophagy associated with many diseases. In this study, we demonstrate that YAP promotes autophagy by interacting with beclin 1, upregulating beclin 1 and LC3B-II protein expression, and promoting autophagosome formation after H. pylori infection in a vacuolating cytotoxin A-dependent manner. The protein levels of β-catenin in the cytoplasm and nuclei of GES-1 cells and the mRNA levels of Axin2, Myc, Lgr5, and Ccnd1 were increased in H. pylori-infected cells or YAP-overexpressed cells, but were decreased in YAP-silenced cells. The β-catenin inhibitor XAV939 significantly downregulated autophagy, whereas the activator LiCl showed opposite effects. An H. pylori-infected mouse model of gastric carcinoma was successfully established. The mouse model showed that H. pylori infection, when combined with NMU, promoted the tumorigenesis of gastric tissues; increased IL-1β, IL-6, and TNF-α levels; promoted NO release; and increased the expression of beclin 1, LC3B-II more than NMU alone. Chloroquine inhibited these phenomena, but did not completely attenuate the effects of H. pylori. These results demonstrate that chloroquine can be used as a drug for the treatment of H. pylori-related gastric cancer, but the treatment should simultaneously remove H. pylori.

Autophagy Modulation and Its Implications on Glioblastoma Treatment

Autophagy is a vital cellular process that functions to degrade and recycle damaged organelles into basic metabolites. This allows a cell to adapt to a diverse range of challenging conditions. Autophagy assists in maintaining homeostasis, and it is tightly regulated by the cell. The disruption of autophagy has been associated with many diseases, such as neurodegenerative disorders and cancer. This review will center its discussion on providing an in-depth analysis of the current molecular understanding of autophagy and its relevance to brain tumors. We will delve into the current literature regarding the role of autophagy in glioma pathogenesis by exploring the major pathways of JAK2/STAT3 and PI3K/AKT/mTOR and summarizing the current therapeutic interventions and strategies for glioma treatment. These treatments will be evaluated on their potential for autophagy induction and the challenges associated with their utilization. By understanding the mechanism of autophagy, clinical applications for future therapeutics in treating gliomas can be better targeted.

Autocrine regulation of tumor cell repopulation by Hsp70-HMGB1 alarmin complex

BACKGROUND

Cancer recurrence is regulated by a variety of factors, among which is the material of dying tumor cells; it is suggested that remaining after anti-cancer therapy tumor cells receive a signal from proteins called damage-associated molecular patterns (DAMPs), one of which is heat shock protein 70 (Hsp70).

METHODS

Two models of tumor repopulation were employed, based on minimal population of cancer cells and application of conditioned medium (CM). To deplete the CMs of Hsp70 affinity chromatography on ATP-agarose and immunoprecipitation were used. Cell proliferation and the dynamics of cell growth were measured using MTT assay and xCELLigence technology; cell growth markers were estimated using qPCR and with the aid of ELISA for prostaglandin E detection. Immunoprecipitation followed by mass-spectrometry was employed to identify Hsp70-binding proteins and protein-protein interaction assays were developed to reveal the above protein complexes.

RESULTS

It was found that CM of dying tumor cells contains tumor regrowth-initiating factors and the removal of one of them, Hsp70, caused a reduction in the relapse-activating capacity. The pull out of Hsp70 alone using ATP-agarose had no effect on repopulation, while the immunodepletion of Hsp70 dramatically reduced its repopulation activity. Using proteomic and immunochemical approaches, we showed that Hsp70 in conditioned medium binds and binds another abundant alarmin, the High Mobility Group B1 (HMGB1) protein; the complex is formed in tumor cells treated with anti-cancer drugs, persists in the cytosol and is further released from dying tumor cells. Recurrence-activating power of Hsp70-HMGB1 complex was proved by the enhanced expression of proliferation markers, Ki67, Aurka and MCM-10 as well as by increase of prostaglandin E production and autophagy activation. Accordingly, dissociating the complex with Hsp70 chaperone inhibitors significantly inhibited the pro-growth effects of the above complex, in both in vitro and in vivo tumor relapse models.

CONCLUSIONS

These data led us to suggest that the abundance of the Hsp70-HMGB1 complex in the extracellular matrix may serve as a novel marker of relapse state in cancer patients, while specific targeting of the complex may be promising in the treatment of cancers with a high risk of recurrence.

COTE-1 promotes the proliferation and invasion of small cell lung cancer by regulating autophagy activity via the AMPK/mTOR signaling pathway

BACKGROUND

COTE-1 has been found to promote the proliferation and invasion of non-small cell lung cancer. However, the mechanism of COTE-1 in SCLC is still unclear. Exploring the role of COTE-1 in SCLC is expected to provide a potential target for the prognosis and treatment of SCLC.

METHODS

The expression of COTE-1 and ki-67 was detected by immunohistochemical staining. PCR detected COTE-1 expression level. Cell proliferation activity was detected by CCK8 assay. A wound healing test detected cell migrative ability. Transwell invasion assay detected cell invasive ability. The numbers of autophagosomes were observed by transmission electron microscopy. WB detected the expression levels of autophagy-related proteins and AMPK/mTOR pathway-related proteins. The effect of COTE-1 expression level on the proliferation of SCLC tumor tissues was investigated by establishing a mouse SCLC xenograft tumor model.

RESULTS

The expression of COTE-1 in SCLC tissues and cells was higher than that in normal tissues and cells. In SCLC cells with high COTE-1 expression, the expression level of autophagy proteins was notably increased, the number of intracellular autophagosomes increased, and the proliferative activity, migration and invasion abilities were enhanced. COTE-1 promotes autophagy, proliferation, and invasion of SCLC cells under nutrient deprivation by activating the AMPK/mTOR signaling pathway. Activation of autophagy by COTE-1 promotes the proliferation and development of xenograft tumors in a mouse model of SCLC.

CONCLUSION

COTE-1 promotes the proliferation, migration and invasion of small cell lung cancer by mediating autophagy based on the AMPK/mTOR pathway.

Mechanosensitive Piezo1 channel in physiology and pathophysiology of the central nervous system

Since the discovery of the mechanosensitive Piezo1 channel in 2010, there has been a significant amount of research conducted to explore its regulatory role in the physiology and pathology of various organ systems. Recently, a growing body of compelling evidence has emerged linking the activity of the mechanosensitive Piezo1 channel to health and disease of the central nervous system. However, the exact mechanisms underlying these associations remain inadequately comprehended. This review systematically summarizes the current research on the mechanosensitive Piezo1 channel and its implications for central nervous system mechanobiology, retrospects the results demonstrating the regulatory role of the mechanosensitive Piezo1 channel on various cell types within the central nervous system, including neural stem cells, neurons, oligodendrocytes, microglia, astrocytes, and brain endothelial cells. Furthermore, the review discusses the current understanding of the involvement of the Piezo1 channel in central nervous system disorders, such as Alzheimer's disease, multiple sclerosis, glaucoma, stroke, and glioma.

The Importance of M1-and M2-Polarized Macrophages in Glioma and as Potential Treatment Targets

Glioma is the most common and malignant tumor of the central nervous system. Glioblastoma (GBM) is the most aggressive glioma, with a poor prognosis and no effective treatment because of its high invasiveness, metabolic rate, and heterogeneity. The tumor microenvironment (TME) contains many tumor-associated macrophages (TAMs), which play a critical role in tumor proliferation, invasion, metastasis, and angiogenesis and indirectly promote an immunosuppressive microenvironment. TAM is divided into tumor-suppressive M1-like (classic activation of macrophages) and tumor-supportive M2-like (alternatively activated macrophages) polarized cells. TAMs exhibit an M1-like phenotype in the initial stages of tumor progression, and along with the promotion of lysing tumors and the functions of T cells and NK cells, tumor growth is suppressed, and they rapidly transform into M2-like polarized macrophages, which promote tumor progression. In this review, we discuss the mechanism by which M1- and M2-polarized macrophages promote or inhibit the growth of glioblastoma and indicate the future directions for treatment.

Deubiquitinating enzyme USP10 promotes osteosarcoma metastasis and epithelial-mesenchymal transition by stabilizing YAP1

BACKGROUND

Osteosarcoma (OS) is a fatal adolescent tumor, which is susceptible to remote metastases at an early stage, and its treatment remains a major challenge. ubiquitin-specific protease 10 (USP10) is primarily located in the cytoplasm and can therefore deubiquitinate various cytoplasmic proteins. However, the expression and mechanism of USP10 in OS remain ambiguous. The aim of this study was to explore how USP10 affects Yes-associated protein1 (YAP1) to influence the metastasis and epithelial-mesenchymal transition (EMT).

METHODS

Western blotting, qRT-PCR, and immunohistochemical (IHC) analyses were performed to evaluate USP10 and YAP1 levels. Using wound healing and transwell tests, the roles and molecular pathways of USP10 and YAP1 ability to migrate and invade of OS were investigated, and cell morphological alterations were examined using phalloidin staining.

RESULTS

Our results indicated that USP10, a new type of deubiquitinating protease, is increased in OS tissues and cells contrasted with adjacent healthy tissues. Overexpression of USP10 correlated with tumor size, distant metastasis, and TNM stage, and was an independent factor of poor prognosis in OS patients. Also, USP10 expression is closely connected with the incident of OS metastasis and tumor size. Functional assays revealed that USP10 knockdown suppressed cell migrating and invading ability and inhibited the EMT of OS cells in vivo and in vitro. In addition, we showed that USP10 knockdown decreased the levels of YAP1, which is an important positive regulator of migration and invasion in many cancers. We also found a significant positive correlation between USP10 and YAP1 levels, further demonstrating that USP10-induced migration and EMT are based on YAP1 in OS cells. In a mechanistic way, USP10 stabilizes the expression of YAP1 by mediating its deubiquitination in OS cells.

CONCLUSION

Together, this study showed that USP10 can directly interact with YAP1 to reduce ubiquitinated YAP1, thereby stabilizing its protein levels and affecting EMT and distant metastasis in OS cells.

Pyroptosis, ferroptosis, and autophagy cross-talk in glioblastoma opens up new avenues for glioblastoma treatment

Glioma is a common primary tumor of the central nervous system (CNS), with glioblastoma multiforme (GBM) being the most malignant, aggressive, and drug resistant. Most drugs are designed to induce cancer cell death, either directly or indirectly, but malignant tumor cells can always evade death and continue to proliferate, resulting in a poor prognosis for patients. This reflects our limited understanding of the complex regulatory network that cancer cells utilize to avoid death. In addition to classical apoptosis, pyroptosis, ferroptosis, and autophagy are recognized as key cell death modalities that play significant roles in tumor progression. Various inducers or inhibitors have been discovered to target the related molecules in these pathways, and some of them have already been translated into clinical treatment. In this review, we summarized recent advances in the molecular mechanisms of inducing or inhibiting pyroptosis, ferroptosis, or autophagy in GBM, which are important for treatment or drug tolerance. We also discussed their links with apoptosis to better understand the mutual regulatory network among different cell death processes. Video Abstract.

Blunting ROS/TRPML1 pathway protects AFB1-induced porcine intestinal epithelial cells apoptosis by restoring impaired autophagic flux

Aflatoxin B1 (AFB1) is a stable mycotoxin that contaminates animal feed on a large scale and causes severe damage to intestinal cells, induces inflammation and stimulates autophagy. Transient receptor potential mucolipin subfamily 1 (TRPML1) is a regulatory factor of autophagy, but the underlying mechanisms of TRPML1-mediated autophagy in AFB1 intestine toxicity remain elucidated. In the present study, AFB1 (0, 5, 10 μg/mL) was shown to reduce cell viability, increase reactive oxygen species (ROS) accumulation and apoptosis rate. Additionally, AFB1 caused structural damage to mitochondria and lysosomes and increased autophagosomes numbers. Furthermore, AFB1 promoted Ca²⁺ release by activating the TRPML1 channel, stimulated the expression of autophagy-related proteins, and induced autophagic flux blockade. Moreover, pharmacological inhibition of autophagosome formation by 3-methyladenine attenuated AFB1-induced apoptosis by downregulating the levels of TRPML1 and ROS, whereas blockade of autophagosome-lysosomal fusion by chloroquine alleviated AFB1-induced apoptosis by upregulating TRPML1 expression and exacerbating ROS accumulation. Intriguingly, blocking AFB1-induced autophagic flux generated ROS- and TRPML1-dependent cell death, as shown by the decreased apoptosis in the presence the free radical scavenger N-Acetyl-L-cysteine and the TRPML1 inhibitor ML-SI1. Overall, these results showed that AFB1 promoted apoptosis of IPEC-J2 cells by disrupting autophagic flux through activation of the ROS/TRPML1 pathway.

The role of high mobility group box 1 in neuroinflammatory related diseases

High mobility group box 1 (HMGB1) is a ubiquitous and highly conserved non-histone DNA-binding protein with different biological functions according to its subcellular localization. It is widely believed that HMGB1, which is released into the extracellular space, plays a key role in the inflammatory response. In recent years, numerous studies have shown that the development of various neurological diseases such as epilepsy, Alzheimer's disease (AD), Parkinson's disease (PD), amyotrophic lateral sclerosis (ALS), multiple sclerosis (MS), cerebrovascular disease and traumatic brain injury (TBI) are inextricably linked to inflammation. We will review the mechanisms of HMGB1 and its receptors in nervous system inflammation to provide a basis for further development of new HMGB1-based therapies.

Angelicin impedes the progression of glioblastoma via inactivation of YAP signaling pathway

Glioblastoma (GBM) is a human malignant tumor with low survival and high recurrence rate. Angelicin, an active furanocoumarin compound, has been reported to possess potential antitumor activity towards various malignancies. However, the effect of angelicin on GBM cells and its mechanism are still unclear. In this study, we found that angelicin inhibited the proliferation of GBM by inducing the cell cycle arrested in G1 phase and suppressed the migration of GBM cells in vitro. Mechanically, we found that angelicin downregulated the expression of YAP and decreased the nuclear localization of YAP, and suppressed the expression of β-catenin. Furthermore, overexpression of YAP partially restored the inhibitory effect of angelicin on GBM cells in vitro. Finally, we found that angelicin could inhibit the growth of tumor and reduce the expression of YAP in the subcutaneous xenograft model of GBM in nude mice and the syngeneic intracranial orthotopic model of GBM in C57BL/6 mice. Taken together, our results suggest that the natural product angelicin exerts its anticancer effects on GBM via YAP signaling pathway, and is expected to be a promising compound for the treatment of GBM.

CircRNA-104718 promotes glioma malignancy through regulation of miR-218-5p/HMGB1 signalling pathway

Increasing number of studies have proven that circular RNAs (circRNAs) play a major role in the biological processes of many different cancers, including glioma, especially as competitive molecular sponges of microRNAs (miRNAs). However, the clear molecular mechanism of the circRNA network in glioma is still not well understood. The expression level of circRNA-104718 and microRNA (miR)-218-5p in glioma tissues and cells were detected by quantitative real-time polymerase chain reaction (qRT-PCR). The target protein's expression level was assessed by western blotting. Bioinformatics systems were used to predict the possible microRNAs and target genes of circRNA-104718, after which dual-luciferase reporter assays were used to confirm the predicted interactions. The proliferation, invasion, migration and apoptosis of glioma cells were detected by CCK, EdU, transwell, wound-healing and flow cytometry assays. CircRNA-104718 was upregulated in human glioma tissues, and a higher level of circRNA-104718 indicated poorer outcomes in glioma patients. In contrast, in glioma tissues, miR-218-5p was downregulated. Knockdown of circRNA-104718 suppressed migration and invasion while boosting the apoptosis rate of glioma cells. In addition, the upregulation of miR-218-5p in glioma cells caused the same suppression. Mechanistically, circRNA-104718 inhibited the protein expression level of high mobility group box-1 (HMGB1) by acting as a molecular sponge for miR-218-5p. CircRNA-104718 is a suppressive factor in glioma cells and might represent a new target for the treatment of glioma patients. CircRNA-104718 modulates glioma cell proliferation through the miR-218-5p/HMGB1 signalling axis. CircRNA-104718 provides a possible mechanism for understanding the pathogenesis of glioma.

Autophagy, molecular chaperones, and unfolded protein response as promoters of tumor recurrence

Tumor recurrence is a paradoxical function of a machinery, whereby a small proportion of the cancer cell population enters a resistant, dormant state, persists long-term in this condition, and then transitions to proliferation. The dormant phenotype is typical of cancer stem cells, tumor-initiating cells, disseminated tumor cells, and drug-tolerant persisters, which all demonstrate similar or even equivalent properties. Cancer cell dormancy and its conversion to repopulation are regulated by several protein signaling systems that inhibit or induce cell proliferation and provide optimal interrelations between cancer cells and their special niche; these systems act in close connection with tumor microenvironment and immune response mechanisms. During dormancy and reawakening periods, cell proteostasis machineries, autophagy, molecular chaperones, and the unfolded protein response are recruited to protect refractory tumor cells from a wide variety of stressors and therapeutic insults. Proteostasis mechanisms functionally or even physically interfere with the main regulators of tumor relapse, and the significance of these interactions and implications in the tumor recurrence phases are discussed in this review.

2,2'-((1R,3R,4S)-4-methyl-4-vinylcyclohexane-1,3-diyl) bis(prop-2-en-1-amine), a bisamino derivative of β-Elemene, inhibits glioblastoma growth through downregulation of YAP signaling

β-Elemene, a compound extracted from Chinese herb Curcuma wenyujin, has been demonstrated with antitumor effects in various cancers, including glioblastoma (GBM), a primary brain tumor with high morbidity and mortality. In this study, we reported a bisamino derivative of β-Elemene, 2, 2'-((1R, 3R, 4S)-4-methyl-4-vinylcyclohexane-1, 3-diyl) bis(prop-2-en-1-amine) (compound 1), displayed a better anti-GBM effect than β-Elemene with lower concentration. GBM cell lines (C6 and U87) were treated with compound 1 and subsequently analyzed by several assays. Compound 1 significantly inhibited the migration of C6 and U87 cells based on wound healing assay, transwell assay and inverted migration assay. Furthermore, colony formation assay, immunostaining and flow cytometry assays revealed that compound 1 significantly inhibited the proliferation of GBM cells. In addition, compound 1 induced the apoptosis of GBM cells. Mechanistically, we found Yes-associated protein (YAP) was down-regulated in compound 1-treated GBM cells, and the overexpression of YAP partially rescued the anti-GBM effects of compound 1. Finally, compound 1 suppresses the GBM growth in xenograft model through inactivation YAP signaling. Taken together, these results reveal that a novel derivative of β-Elemene, compound 1, exhibits more potent anti-GBM activity than β-Elemene through inactivating YAP signaling pathway, which will provide novel strategies for the treatment of GBM.

SAR1A regulates the RhoA/YAP and autophagy signaling pathways to influence osteosarcoma invasion and metastasis

Osteosarcoma is the most prevalent form of primary bone malignancy affecting adolescents. Secretion-associated Ras-related GTPase 1A (SAR1A) is a key regulator of endoplasmic reticulum (ER) homeostasis, but its role as a regulator of osteosarcoma metastasis has yet to be clarified. Bioinformatics analyses revealed SAR1A and RHOA to be upregulated in osteosarcoma patients, with the upregulation of these genes being associated with poor 5-year metastasis-free survival rates. In addition, the upregulation of SAR1A and RHOA in osteosarcoma was highly positively correlated. Immunohistochemical analyses additionally revealed that SAR1A levels were increased in osteosarcoma pulmonary metastases. In vitro wound healing and Transwell assays indicated that knocking down SAR1A or RHOA impaired the invasive and migratory activity of osteosarcoma cells, whereas RHOA overexpression had the opposite effect. Western blotting and immunofluorescent staining revealed the inhibition of osteosarcoma cell epithelial-mesenchymal transition following SAR1A or RHOA knockdown; RHOA overexpression had the opposite effect. Following SAR1A knockdown, phalloidin staining indicated that osteosarcoma cells showed reduced lamellipodia formation. Endoplasmic reticulum stress levels and reactive oxygen species production were enhanced following the knockdown of SAR1A, as was autophagic activity, with lung metastases being reduced in vivo after such knockdown. Knocking down SAR1A suppresses osteosarcoma cell metastasis through the RhoA/YAP, ER stress, and autophagic pathways, offering new insights into the regulation of autophagic activity in the context of osteosarcoma cell metastasis and suggesting that these pathways could be amenable to therapeutic intervention.

Irigenin inhibits glioblastoma progression through suppressing YAP/β-catenin signaling

Glioblastoma (GBM) is the most malignant glioma in brain tumors with low survival and high recurrence rate. Irigenin, as an isoflavone compound extracted from Shegan, has shown many pharmacological functions such as antioxidant, anti-inflammatory and anti-tumor. However, the effects of irigenin on GBM cells and the related molecular mechanisms remain unexplored. In this study, we found that irigenin inhibited the proliferation of GBM cells in a dose-dependent manner by several assays in vitro. Subsequently, we found that irigenin arrested cell cycle at G2/M phase and induced apoptosis of GBM cells in vitro. In addition, irigenin inhibited the migration of GBM cells. Mechanically, we found that irigenin treatment decreased the expression of YAP (yes-associated protein), suppressed β-catenin signaling. Furthermore, overexpression of YAP partially restored the anti-tumor effects of irigenin on GBM cells in vitro. Finally, we found that irigenin inhibited the growth of tumor in GBM xenograft mice model through inactivation of YAP. Taken together, these results suggest that irigenin exerts its anticancer effects on GBM via inhibiting YAP/β-catenin signaling, which may provide a new strategy for the treatment of GBM.

SU4312 Represses Glioma Progression by Inhibiting YAP and Inducing Sensitization to the Effect of Temozolomide

SU4312, initially designed as a multi-target tyrosine kinase inhibitor, is consequently reported to inhibit tumor angiogenesis by blocking VEGFR. However, although SU4312 can penetrate the brain–blood barrier, its potential to inhibit glioma growth is unknown. In this study, we report that SU4312 inhibited glioma cell proliferation and down-regulated yes-associated protein (YAP), the key effector of the hippo pathway. The exogenous over-expression of YAP partially restored the inhibitory effect of SU4312 on glioma progression. Interestingly, SU4312 sensitized the antitumor effect of temozolomide, both in vitro and in vivo. Moreover, SU4312 decreased the M2tumor-associated macrophages and enhanced anti-tumor immunity by down-regulating the YAP-CCL2 axis. In conclusion, our results suggest that SU4312 represses glioma progression by down-regulating YAP transcription and consequently CCL2 secretion. SU4312 may be synergistic with temozolomide for glioma treatment.

Hypoxia-induced HMGB1 promotes glioma stem cells self-renewal and tumorigenicity via RAGE

Glioma stem cells (GSCs) in the hypoxic niches contribute to tumor initiation, progression, and recurrence in glioblastoma (GBM). Hypoxia induces release of high-mobility group box 1 (HMGB1) from tumor cells, promoting the development of tumor. Here, we report that HMGB1 is overexpressed in human GBM specimens. Hypoxia promotes the expression and secretion of HMGB1 in GSCs. Furthermore, silencing HMGB1 results in the loss of stem cell markers and a reduction in self-renewal ability of GSCs. Additionally, HMGB1 knockdown inhibits the activation of RAGE-dependent ERK1/2 signaling pathway and arrests the cell cycle in GSCs. Consistently, FPS-ZM1, an inhibitor of RAGE, downregulates HMGB1 expression and the phosphorylation of ERK1/2, leading to a reduction in the proliferation of GSCs. In xenograft mice of GBM, HMGB1 knockdown inhibits tumor growth and promotes mouse survival. Collectively, these findings uncover a vital function for HMGB1 in regulating GSC self-renewal potential and tumorigenicity.

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Glioma stem cells overexpress HMGB1 in human glioblastoma

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Hypoxia induces the upregulation and release of HMGB1 in glioma stem cells

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HMGB1 promotes the self-renewal of glioma stem cells via RAGE

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Targeting HMGB1 inhibits the tumorigenesis of glioma stem cells

Research Progress on the Regulation Mechanism of Key Signal Pathways Affecting the Prognosis of Glioma

As is known to all, glioma, a global difficult problem, has a high malignant degree, high recurrence rate and poor prognosis. We analyzed and summarized signal pathway of the Hippo/YAP, PI3K/AKT/mTOR, miRNA, WNT/β-catenin, Notch, Hedgehog, TGF-β, TCS/mTORC1 signal pathway, JAK/STAT signal pathway, MAPK signaling pathway, the relationship between BBB and signal pathways and the mechanism of key enzymes in glioma. It is concluded that Yap1 inhibitor may become an effective target for the treatment of glioma in the near future through efforts of generation after generation. Inhibiting PI3K/Akt/mTOR, Shh, Wnt/β-Catenin, and HIF-1α can reduce the migration ability and drug resistance of tumor cells to improve the prognosis of glioma. The analysis shows that Notch1 and Sox2 have a positive feedback regulation mechanism, and Notch4 predicts the malignant degree of glioma. In this way, notch cannot only be treated for glioma stem cells in clinic, but also be used as an evaluation index to evaluate the prognosis, and provide an exploratory attempt for the direction of glioma treatment. MiRNA plays an important role in diagnosis, and in the treatment of glioma, VPS25, KCNQ1OT1, KB-1460A1.5, and CKAP4 are promising prognostic indicators and a potential therapeutic targets for glioma, meanwhile, Rheb is also a potent activator of Signaling cross-talk etc. It is believed that these studies will help us to have a deeper understanding of glioma, so that we will find new and better treatment schemes to gradually conquer the problem of glioma.

Research Progress on the Regulation Mechanism of Key Signal Pathways Affecting the Prognosis of Glioma

As is known to all, glioma, a global difficult problem, has a high malignant degree, high recurrence rate and poor prognosis. We analyzed and summarized signal pathway of the Hippo/YAP, PI3K/AKT/mTOR, miRNA, WNT/β-catenin, Notch, Hedgehog, TGF-β, TCS/mTORC1 signal pathway, JAK/STAT signal pathway, MAPK signaling pathway, the relationship between BBB and signal pathways and the mechanism of key enzymes in glioma. It is concluded that Yap1 inhibitor may become an effective target for the treatment of glioma in the near future through efforts of generation after generation. Inhibiting PI3K/Akt/mTOR, Shh, Wnt/β-Catenin, and HIF-1α can reduce the migration ability and drug resistance of tumor cells to improve the prognosis of glioma. The analysis shows that Notch1 and Sox2 have a positive feedback regulation mechanism, and Notch4 predicts the malignant degree of glioma. In this way, notch cannot only be treated for glioma stem cells in clinic, but also be used as an evaluation index to evaluate the prognosis, and provide an exploratory attempt for the direction of glioma treatment. MiRNA plays an important role in diagnosis, and in the treatment of glioma, VPS25, KCNQ1OT1, KB-1460A1.5, and CKAP4 are promising prognostic indicators and a potential therapeutic targets for glioma, meanwhile, Rheb is also a potent activator of Signaling cross-talk etc. It is believed that these studies will help us to have a deeper understanding of glioma, so that we will find new and better treatment schemes to gradually conquer the problem of glioma.

Co-loaded lapatinib/PAB by ferritin nanoparticles eliminated ECM-detached cluster cells via modulating EGFR in triple-negative breast cancer

Cancer stem cell (CSC) cluster of triple-negative breast cancer (TNBC) is suggested to be responsible for therapy resistance, metastatic process and cancer recurrence, yet the sensitivity of CSC clusters of TNBC to ferroptosis remains elusive in a great measure. Current research revealed that epidermal growth factor receptor (EGFR) reinforced CD44-mediated TNBC cell clustering, whether blockade of EGFR has synergistic effects on erastin-induced tumor inhibition of CSC clusters is still poorly understood. Here, we found that fraction of CD24^lowCD44^high cells and size of tumor spheres clearly decreased following EGFR inhibition in TNBC cells. Inhibition of EGFR promoted expression of LC3B-II via YAP/mTOR signaling pathway, indicating that EGFR-mediated autophagy which contributed to ferroptosis. In order to further verify the protective effects of EGFR on ferroptosis induced by small molecules in TNBC cells, pseudolaric acid B (PAB) which led to ferroptosis of malignant cells was selected. In our experiment, lapatinib and PAB cotreatment inhibited TNBC cells viability and restrained formation of tumor spheres, accompanied with a high level of intracellular ROS. To target delivery lapatinib and PAB to TNBC cells, lapatinib/PAB@Ferritin (L/P@Ferritin) nanoparticles were prepared; results of in vitro and in vivo showed a higher tumor suppression efficiency of L/P@Ferritin, highlighting that it might provide a new perspective for treatment of CSC clusters of TNBC.

YAP knockdown in combination with ferroptosis induction increases the sensitivity of HOS human osteosarcoma cells to Pyropheophorbide-α methyl ester-mediated photodynamic therapy

BACKGROUND AND AIMS

This study was designed to explore the effects of Yes-associated protein (YAP) knockdown on human osteosarcoma (HOS) cell sensitivity to Pyropheophorbide-α methyl ester-mediated photodynamic therapy (MPPa-PDT), and to assess how YAP silencing in combination with treatment with the ferroptosis inducer Erastin improves HOS cell sensitivity to MPPa-PDT in an effort to better clarify the molecular mechanisms underlying these phenotypes.

METHODS

At 12 h post-MPPa-PDT, Hoechst staining and flow cytometry were conducted to evaluate the apoptotic death of HOS cells. The expression of YAP in these cells at 12 h post-MPPa-PDT treatment was assessed via Western blotting and immunofluorescent staining. BODIPY^581/591-C11 was used to evaluate lipid peroxidation. Following shYAP lentiviral transduction, Western blotting was conducted to assess the expression of proteins associated with proliferation, apoptosis, and ferroptosis. EdU assays and clonogenic assays were performed to analyze cellular proliferation. Erastin-treated HOS cells were used to establish a ferroptosis model. Western blotting was used to measure ferroptosis-associated protein levels following shYAP and erastin treatment, while changes in proliferation and MDA levels in each group were examined using an MDA kit.

RESULTS

At 12 h post-MPPa-PDT, HOS cells exhibited apoptotic characteristics including nuclear fragmentation and pyknosis, with concomitant increases in apoptosis-associated proteins as detected via Western blotting and apoptotic induction as measured via flow cytometry. Phosphorylated YAP levels fell and non-phosphorylated YAP levels rose following such treatment. Transfection with shYAP was successful as a means of generating stable HOS cell lines, and Western blotting analyses of these cells revealed reductions in proteins associated with cellular proliferation together with the upregulation of apoptosis-related proteins.  MDA assays indicated that erastin combined with YAP knockdown enhanced the sensitivity of HOS cells to MPPa-PDT treatment.

CONCLUSIONS

These data indicate that ferroptosis and YAP knockdown can enhance osteosarcoma cell sensitivity to MPPa-PDT therapy.

The biology of YAP in programmed cell death

In the last few decades, YAP has been shown to be critical in regulating tumor progression. YAP activity can be regulated by many kinase cascade pathways and proteins through phosphorylation and promotion of cytoplasmic localization. Other factors can also affect YAP activity by modulating its binding to different transcription factors (TFs). Programmed cell death (PCD) is a genetically controlled suicide process present with the scope of eliminating cells unnecessary or detrimental for the proper development of the organism. In some specific states, PCD is activated and facilitates the selective elimination of certain types of tumor cells. As a candidate oncogene correlates with many regulatory factors, YAP can inhibit or induce different forms of PCD, including apoptosis, autophagy, ferroptosis and pyroptosis. Furthermore, YAP may act as a bridge between different forms of PCD, eventually leading to different outcomes regarding tumor development. Researches on YAP and PCD may benefit the future development of novel treatment strategies for some diseases. Therefore, in this review, we provide a general overview of the cellular functions of YAP and the relationship between YAP and PCD.