TIM-4 orchestrates mitochondrial homeostasis to promote lung cancer progression via ANXA2/PI3K/AKT/OPA1 axis

ANXA2 regulates mitochondrial function and cellular senescence of PDLCs via AKT/eNOS signaling pathway under high glucose conditions

Diabetes mellitus is one of the risk factors for periodontitis. Patients with diabetes mellitus possess higher prevalence of periodontitis, more severe periodontal destruction, yet the underlying mechanisms of action are not yet clear. Annexin A2 (ANXA2) is a calcium-dependent phospholipid-binding protein widely involved in membrane repair, cytokinesis, and endocytosis. In this study, we explore whether ANXA2 is one of the associative links between diabetes and periodontitis and find out its underlying mechanisms. Cellular senescence and mitochondrial functions (ROS, mitochondrial morphology, mitochondrial autophagy) were observed. We observed that ANXA2 expression was down-regulated in Periodontal ligament cells (PDLCs) under high glucose conditions. Furthermore, overexpression of ANXA2 delayed high glucose-induced cellular senescence and mitochondrial dysfunction. β-galactosidase activity and the mRNA levels of the senescence-relative genes(p21,p16) were decreased, mitochondrial fracture and ROS release were reduced, and the expression of mitochondrial autophagy-related proteins (LC3,p62,Parkin) was enhanced. expression was enhanced. Mechanistically, we demonstrated that it can regulate the AKT/eNOS signaling pathway by knockdown and overexpression of ANXA2 which was measured using Western blotting (WB) assay to measure the expression of eNOS, p-eNOS Ser1177, Akt and p-Akt Ser473 proteins in PDLCs. After that, we used AKT and eNOS inhibitors to demonstrate the protective effect of ANXA2 on PDLCs under high glucose conditions. The above results suggest that ANXA2 has an anti-aging protective effect, attenuates high glucose-induced cellular senescence in PDLCs, and maintains mitochondrial homeostasis. Therefore, it would be valuable to further explore its role in the link between diabetes and periodontitis in future experiments.

Rab5if is a potential therapeutic target of NSCLC

PURPOSE

Due to disease progression and drug resistance, non-small cell lung cancer(NSCLC) mortality remains high, and the study of new targets that can inhibit tumor growth is very necessary. The purpose of this study was to investigate the role of Rab5if in the occurrence and development of NSCLC and explore its potential role in the treatment of NSCLC.

MATERIALS AND METHODS

Rab5if overexpression and knockdown non-small cell lung cancer cell lines were constructed by lentivirus. Cellular assays were conducted to assess the impact of Rab5if on the functionality of lung cancer cells, The mechanism by which Rab5if influences the function of lung cancer cells was confirmed through Western blot analysis. The in vivo experiment was used to further verify the results of the in vitro experiment.

RESULTS

Bioinformatics research found Rab5if mRNA increased in patients with NSCLC. Increased mRNA and protein levels of Rab5if were confirmed in local human NSCLC tissues. Knockdown of Rab5if in NSCLC cell lines by lentivirus significantly inhibited cell vigour, propagation and migration. In addition, mitochondrial function was impaired in lung cancer cells after Rab5if knockdown. In contrast, Rab5if overexpression promoted the proliferation and migration of NSCLC. Moreover, the impact Rab5if on the function of lung cancer cells was realized through the AKT-mTOR pathway. In the in vivo study, growth inhibition were observed in lung cancer xenografts transfected with Rab5if shRNA in nude mice. Similarly, xenografts of nude mice overexpressing Rab5if grew rapidly. The same pathway as in vitro was confirmed in vivo.

CONCLUSION

Rab5if is expected to be a novel therapeutic target for NSCLC.

ANXA2 in cancer: aberrant regulation of tumour cell apoptosis and its immune interactions

Annexin A2 (ANXA2) is a multifunctional protein that binds to calcium and phospholipids and plays a critical role in various pathological conditions, including cancer and inflammation. Recently, there has been increasing recognition of the significant role of ANXA2 in inhibiting apoptosis and promoting immune evasion in tumour cells. Therefore, a deep understanding of the regulatory mechanisms of ANXA2 in tumour cell apoptosis and its relationship with immune evasion can provide new targets for cancer therapy. This review summarizes the role and mechanisms of ANXA2 in regulating apoptosis in tumour cells, the connection between apoptosis regulation and tumour immunity, and the potential role of ANXA2 in therapy resistance.

Identification of Versican as a target gene of the transcription Factor ZNF587B in ovarian cancer

Ovarian cancer is the most lethal malignancy affecting the female reproductive system, with its progression and metastasis being significant contributors to patient mortality. Our previous study identified the zinc finger protein ZNF587B as a potential tumor suppressor that inhibited the proliferation, migration and invasion of ovarian cancer cells, although the underlying mechanism remains elusive. In this study, ZNF587B was demonstrated to bind directly to the promoter region of Versican (VCAN), a high molecular weight chondroitin sulfate glycoprotein, and repress its transcription using Chromatin immunoprecipitation-qPCR (ChIP-qPCR), luciferase reporter assays, and immunofluorescence (IF). Moreover, in vivo and in vitro assays revealed that the effect of ZNF587B knockdown on ovarian cancer proliferation may be mediated through VCAN. Not only that, patients with reduced expression of ZNF587B and increased expression of VCAN exhibit a poorer prognosis. The potential mechanism behind this may involve its impact on the phosphorylation process of AKT.

Promotion Mechanisms of Stromal Cell-Mediated Lung Cancer Development Within Tumor Microenvironment

Lung cancer, with its high incidence and mortality rates, has garnered significant attention in the medical community. The tumor microenvironment (TME), composed of tumor cells, stromal cells, extracellular matrix, surrounding blood vessels, and other signaling molecules, plays a pivotal role in the development of lung cancer. Stromal cells within the TME hold potential as therapeutic targets for lung cancer treatment. However, the precise and comprehensive mechanisms by which stromal cells contribute to lung cancer progression have not been fully elucidated. This review aims to explore the mechanisms through which stromal cells in the tumor microenvironment promote lung cancer development, with a particular focus on how immune cells, tumor-associated fibroblasts, and endothelial cells contribute to immune suppression, inflammation, and angiogenesis. The goal is to provide new insights and potential strategies for the diagnosis and treatment of lung cancer.

SUCLG1 promotes aerobic respiration and progression in plexiform neurofibroma

Plexiform neurofibromas (PNFs) are benign tumors that affect 20‑50% of patients with type I neurofibromatosis (NF1). PNF carries a risk of malignancy. There is no effective cure for PNF. Its onset may be associated with genetic and metabolic abnormalities, but the exact mechanisms remain unclear. Succinate‑CoA ligase GDP/ADP‑Forming Subunit α(SUCLG1), a catalytic enzyme in the tricarboxylic acid cycle, is highly expressed in PNF. The present study aimed to explore the role of SUCLG1 in function and metabolism of PNF cells. SUCLG1 expression was verified using western blotting and immunofluorescence. After inducing SUCLG1 knockdown and overexpression, functional changes in PNF cells were assessed, as well as effects of SUCLG1 on cell respiration and glucose metabolism. Quantitative PCR, WB, electron microscopy and Flow cytometry demonstrated that SUCLG1 enhanced mitochondrial quality and promoted mitochondrial fusion, thereby driving proliferation and migration of tumor cells, inhibiting apoptosis and altering the cell cycle. A Seahorse assay showed that elevated SUCLG1 expression enhanced cell aerobic respiration without affecting the glycolytic process. This suggests that SUCLG1 upregulation in PNF does not trigger the Warburg effect associated with malignant tumors. This study also demonstrated the positive regulation of cellular function by promoting the expression level of the SLC25A1 gene when SUCLG1 expression was elevated. In conclusion, SUCLG1 altered the mechanism of mitochondrial quality control to enhance cell aerobic respiration, thereby driving the pathogenesis of PNF. Thus, SUCLG1 can serve as a potential target in future therapeutic strategies.

A dynamic co-expression approach reveals Gins2 as a potential upstream modulator of HNSCC metastasis

Head and neck squamous cell carcinoma (HNSCC) is an aggressive cancer that is notably associated with a high risk of lymph node metastasis, a major cause of cancer mortality. Current therapeutic options remain limited to surgery supplemented by radio- or chemotherapy; however, these interventions often result in high-grade toxicities. Distant metastasis significantly contributed to the poor prognosis and decreased survival rates. However, the underlying molecular mechanisms remain poorly understood. Disease-related "omics" data provide a comprehensive overview of gene relationships, helping to decode the complex molecular mechanisms involved. Interactions between biological molecules are complex and highly dynamic across various cellular conditions, making traditional co-expression methods inadequate for understanding these intricate relationships. In the present study, a novel three-way interaction approach was employed to uncover dynamic co-expression relationships underlying the metastatic nature of HNSCC. Subsequently, the biologically relevant triples from statistically significant ones were defined through gene set enrichment analysis and reconstruction of the gene regulatory network. Finally, the validity of biologically relevant triplets was assessed at the protein level. The results highlighted the "PI3K/AKT/mTOR (PAM) signaling pathway" as a disrupted pathway involved in the metastatic nature of HNSCC. Notably, Gins2, identified as a switch gene, along with the gene pair {Akt2, Anxa2}, formed a statistically significant and biologically relevant triplet. It suggests that Gins2 could serve as a potential upstream modulator in the PAM signaling pathway, playing a crucial role in the distant metastasis of HNSCC. In addition, survival analysis of significant switch genes indicated that two genes, C19orf33 and Usp13, may be especially important for prognostic purposes in HNSCC.

Verbascum ponticum (Stef.) Extract Induces Lung Cancer Apoptosis via Mitochondrial-Dependent Apoptosis Pathway

Non-small-cell lung carcinoma remains a significant health concern due to its high incidence and mortality rates. Traditional medicines play a central role in cancer therapy, with plant-derived bioactive compounds being studied for their potential to offer fewer side effects than conventional treatments. In traditional Kurdish medicine, different Verbascum species are used to treat burns, inflammation, and other conditions. While some species extracts have shown cytotoxic effects against several cancer cell lines like A549, the efficacy and mechanisms of action of the other species like Verbascum ponticum (V. ponticum) remain to be elucidated. Therefore, this study aimed to explore the effect of V. ponticum (Stef.) extract, collected from the Kurdistan region of the Iraq mountains, on A549 cells. A comprehensive approach was employed, utilizing immunocytochemical and functional analyses to assess apoptotic morphology, DNA fragmentation, alongside assays for cellular and mitochondrial function, proliferation, and viability. Additionally, the study investigated AIF mitochondrial translocation and evaluated mitochondrial membrane potential using the Rhodamine 123 assay. The results showed that the V. ponticum flower extract induced mitochondrial-mediated apoptosis in A549 cells via disruption of mitochondrial membrane potential, release of AIF, and translocation to the nucleus, independently of the caspase-3-activation pathway. These findings emphasize the potential of V. ponticum in lung cancer strategic treatments, meriting further phytochemical studies to identify the bioactive compounds it contains.

Mitochondrial dynamics in pulmonary disease: Implications for the potential therapeutics

Mitochondria are dynamic organelles that continuously undergo fusion/fission to maintain normal cell physiological activities and energy metabolism. When mitochondrial dynamics is unbalanced, mitochondrial homeostasis is broken, thus damaging mitochondrial function. Accumulating evidence demonstrates that impairment in mitochondrial dynamics leads to lung tissue injury and pulmonary disease progression in a variety of disease models, including inflammatory responses, apoptosis, and barrier breakdown, and that the role of mitochondrial dynamics varies among pulmonary diseases. These findings suggest that modulation of mitochondrial dynamics may be considered as a valid therapeutic strategy in pulmonary diseases. In this review, we discuss the current evidence on the role of mitochondrial dynamics in pulmonary diseases, with a particular focus on its underlying mechanisms in the development of acute lung injury (ALI)/acute respiratory distress syndrome (ARDS), chronic obstructive pulmonary disease (COPD), asthma, pulmonary fibrosis (PF), pulmonary arterial hypertension (PAH), lung cancer and bronchopulmonary dysplasia (BPD), and outline effective drugs targeting mitochondrial dynamics-related proteins, highlighting the great potential of targeting mitochondrial dynamics in the treatment of pulmonary disease.

Homoplantaginin alleviates high glucose-induced vascular endothelial senescence by inhibiting mtDNA-cGAS-STING pathway via blunting DRP1-mitochondrial fission-VDAC1 axis

Vascular endothelial senescence is a major risk factor for diabetic vascular complications. Abnormal mitochondrial fission by dynamically related protein 1 (DRP1) accelerates vascular endothelial cell senescence. Homoplantaginin (Hom) is a flavonoid in Salvia plebeia R. Br. with protecting mitochondrial and repairing vascular properties. However, the relevant mechanism of Hom against diabetic vascular endothelial cell senescence remains unclear. Here, we used db/db mice and high glucose (HG)-treated human umbilical vein endothelial cells (HUVECs) to assess the anti-vascular endothelial cell senescence of Hom. We found that Hom inhibited senescence-associated β-galactosidase activity, decreased the levels of senescence markers, and senescence-associated secretory phenotype factors. Additionally, Hom inhibited the expression of cGAS-STING pathway and downstream inflammatory factors. STING inhibitor H-151 delayed endothelial senescence, whereas STING overexpression attenuated the anti-endothelial senescence effect of Hom. Furthermore, we observed that Hom reduced mitochondrial fragmentation and inhibited abnormal mitochondrial fission using transmission electron microscopy. Importantly, Hom has a stronger effect on mitochondrial fission protein than mitochondrial fusion protein, especially downregulated the expression of DRP1. DRP1 inhibitor Mdivi-1 suppressed cGAS-STING pathway and vascular endothelial senescence, yet DRP1 agonist FCCP attenuated the effect of Hom. Surprisingly, Hom blunted abnormal mitochondrial fission mediated by DRP1 mitochondrial localization, suppressed interaction of DRP1 with VDAC1 and prevented VDAC1 oligomerization, which was necessary for mtDNA escape and subsequent cGAS-STING pathway activation. These results revealed a previously unrecognized mechanism that Hom alleviated vascular endothelial senescence by inhibited mtDNA-cGAS-STING signaling pathway via blunting DRP1-mitochondrial fission-VDAC1 axis.

Identification of Immune-Related Gene Signature Model for Predicting Lung Cancer Survival and Response to Immunotherapy

INTRODUCTION

Studies have shown that immune-related genes play a crucial role in tumor development and treatment. However, the specific roles and potential value of these genes in lung cancer patients are still not fully understood. Therefore, this study aims to establish a novel risk model based on immune-related genes for evaluating the prognostic risk and response to immune therapy in lung cancer patients.

METHODS

Gene expression and clinical data of lung cancer patients were retrieved from the Cancer Genome Atlas (TCGA) and the Gene Expression Omnibus (GEO) databases, while immune-related genes were obtained from the ImmPort database. A risk signature model was developed using univariate Cox analysis and LASSO regression analysis. The prognostic value of the model and its response to immunotherapy were analyzed by survival analysis, immune infiltration analysis, and immunotherapy response analysis.

RESULTS

We have developed a risk signature model based on eight key immune-related genes, which can classify patients into high-risk and low-risk groups. The prognosis of the high-risk group was significantly lower than that of the low-risk group and was validated in multiple GEO datasets. The mutation frequency was lower in the low-risk group compared to the high-risk group (TP53: 55% vs. 65%; TTN: 52% vs. 60%; CSMD3: 34% vs. 45%). Futhermore, CD274 expression was lower in the low-risk patients, and the high-risk patients in the IMvigor210 cohort had lower survival. Immune infiltration analyses showed that the high-risk group was negatively correlated with the infiltration level of B cells, CD4+ T cells, and NK cells. Importantly, patients in the low-risk group exhibit significantly lower TIDE scores, suggesting that they are more responsive to immunotherapy.

CONCLUSION

Our study has established a novel and robust immune-related gene risk model that can assist in evaluating the prognostic risk and immune therapy response of lung cancer patients.

A novel protein SPECC1-415aa encoded by N6-methyladenosine modified circSPECC1 regulates the sensitivity of glioblastoma to TMZ

BACKGROUND

Circular RNAs (circRNAs) can influence a variety of biological functions and act as a significant role in the progression and recurrence of glioblastoma (GBM). However, few coding circRNAs have been discovered in cancer, and their role in GBM is still unknown. The aim of this study was to identify coding circRNAs and explore their potential roles in the progression and recurrence of GBM.

METHODS

CircSPECC1 was screened via circRNAs microarray of primary and recurrent GBM samples. To ascertain the characteristics and coding ability of circSPECC1, we conducted a number of experiments. Afterward, through in vivo and in vitro experiments, we investigated the biological functions of circSPECC1 and its encoded novel protein (SPECC1-415aa) in GBM, as well as their effects on TMZ sensitivity.

RESULTS

By analyzing primary and recurrent GBM samples via circRNAs microarray, circSPECC1 was found to be a downregulated circRNA with coding potential in recurrent GBM compared with primary GBM. CircSPECC1 suppressed the proliferation, migration, invasion, and colony formation abilities of GBM cells by encoding a new protein known as SPECC1-415aa. CircSPECC1 restored TMZ sensitivity in TMZ-resistant GBM cells by encoding the new protein SPECC1-415aa. The m6A reader protein IGF2BP1 can bind to circSPECC1 to promote its expression and stability. Mechanistically, SPECC1-415aa can bind to ANXA2 and competitively inhibit the binding of ANXA2 to EGFR, thus resulting in the inhibition of the phosphorylation of EGFR (Tyr845) and its downstream pathway protein AKT (Ser473). In vivo experiments showed that the overexpression of circSPECC1 could combine with TMZ to treat TMZ-resistant GBM, thereby restoring the sensitivity of TMZ-resistant GBM to TMZ.

CONCLUSIONS

CircSPECC1 was downregulated in recurrent GBM compared with primary GBM. The m6A reader protein IGF2BP1 could promote the expression and stability of circSPECC1. The sequence of SPECC1-415aa, which is encoded by circSPECC1, can inhibit the binding of ANXA2 to EGFR by competitively binding to ANXA2 and inhibiting the phosphorylation of EGFR and AKT, thereby restoring the sensitivity of TMZ-resistant GBM cells to TMZ.

NUSAP1 promotes gastric cancer radioresistance by inhibiting ubiquitination of ANXA2 and is suppressed by miR-129-5p

BACKGROUND

Radiotherapy is an important strategy for the treatment of advanced gastric cancer (GC), while the radioresistance limits its effectiveness. Nucleolar and spindle associated protein 1 (NUSAP1) was implicated in cancer progression and chemoresistance. However, the underlying mechanisms of NUSAP1 influencing GC radioresistance remain largely unknown.

METHODS

Meta-analysis was conducted to systematically evaluate the prognostic value of NUSAP1 in human cancers. Gene set enrichment analysis (GSEA) was conducted using The Cancer Genome Atlas (TCGA) and gene expression omnibus (GEO) datasets. MRNA and protein expressions were detected by qRT-PCR and western blot, respectively. The radiosensitivity of GC cells was observed by colony formation, flow cytometry, comet, immunofluorescence, and animal assays. Immunoprecipitation assay and mass spectrometry were utilized to identify protein associations. MiRNAs binding with NUSAP1 were determined by starbase prediction, luciferase reporter, and RNA immunoprecipitation (RIP) assays.

RESULTS

NUSAP1 high expression predicted worse overall survival (OS) and disease-free survival (DFS) with no statistical heterogeneity through the meta-analysis. Downregulation of NUSAP1 significantly increased GC radiosensitivity by inhibiting colony formation, DNA damage repair, and promoting apoptosis following irradiation. Additionally, NUSAP1 silencing combined with radiation resulted in a synergistic anti-tumor effect in xenograft mouse model. Mechanistically, NUSAP1 interacted with ANXA2, protecting it against protein degradation via impeding its ubiquitination process. NUSAP1 was confirmed as a target of miR-129-5p and negatively regulated by it.

CONCLUSION

Our results suggested that NUSAP1 enhanced the radioresistance of GC cells. NUSAP1 could be a promising target to increase GC radiosensitivity.

Role and action mechanisms of tPA in CRH-induced apoptosis of mouse oviductal epithelial and mural granulosa cells

Understanding how stress hormones induce apoptosis in oviductal epithelial cells (OECs) and mural granulosa cells (MGCs) can reveal the mechanisms by which female stress impairs embryonic development and oocyte competence. A recent study showed that tissue plasminogen activator (tPA) ameliorates corticosterone-induced apoptosis in MGCs and OECs by acting on its receptors low-density lipoprotein receptor-related protein 1 (LRP1) and Annexin A2 (ANXA2), respectively. However, whether tPA is involved in corticotropin-releasing hormone (CRH)-induced apoptosis and whether it uses the same or different receptors to inhibit apoptosis induced by different hormones in the same cell type remains unknown. This study showed that CRH triggered apoptosis in both OECs and MGCs and significantly downregulated tPA expression. Moreover, tPA inhibits CRH-induced apoptosis by acting on ANXA2 in both OECs and MGCs. While ANXA2 inhibits apoptosis via phosphatidylinositol 3-kinase/protein kinase B (PI3K/Akt) signaling, LRP1 reduces apoptosis via mitogen-activated protein kinase (MAPK) signaling. Thus, tPA used the same receptor to inhibit CRH-induced apoptosis in both OECs and MGCs, however used different receptors to inhibit corticosterone-induced apoptosis in MGCs and OECs. These data helps understand the mechanism by which female stress impairs embryo/oocyte competence and proapoptotic factors trigger apoptosis in different cell types.

Olink Proteomics-Based Exploration of Immuno-Oncology-Related Biomarkers Leading to Lung Adenocarcinoma Progression

INTRODUCTION

It is crucial to investigate the distinct proteins that contribute to the advancement of lung cancer.

MATERIAL AND METHODS

We analyzed the expression levels of 92 immuno-oncology-related proteins in 96 pairs of lung adenocarcinoma tissue samples using Olink proteomics. The differentially expressed proteins (DEPs) were successively screened in tumor and paraneoplastic groups, early and intermediate-late groups by a nonparametric rank sum test, and the distribution and expression levels of DEPs were determined by volcano and heat maps, etc., and the area under the curve was calculated.

RESULTS

A total of 24 DEPs were identified in comparisons between tumor and paracancerous tissues. Among them, interleukin-8 (IL8) and chemokine (C-C motif) ligand 20 (CCL20) as potential markers for distinguishing tumor tissues. Through further screening, it was found that interleukin-6 (IL6) and vascular endothelial growth factor A (VEGFA) may be able to lead to tumor progression through the JaK-STAT signaling pathway, Toll-like receptor signaling pathway and PI3K/AKT signaling pathway. Interestingly, our study revealed a down-regulation of IL6 and VEGFA in tumor tissues compared to paracancerous tissues.

CONCLUSIONS

IL8 + CCL20 (AUC: 0.7056) have the potential to differentiate tumor tissue from paracancerous tissue; IL6 + VEGFA (AUC: 0.7531) are important protein markers potentially responsible for tumor progression.

METTL3-mediated deficiency of lncRNA HAR1A drives non-small cell lung cancer growth and metastasis by promoting ANXA2 stabilization

We previously reported lncRNA HAR1A as a tumor suppressor in non-small cell lung cancer (NSCLC). However, the delicate working mechanisms of this lncRNA remain obscure. Herein, we demonstrated that the ectopic expression of HAR1A inhibited the proliferation, epithelial-mesenchymal transition (EMT), migration, and invasion of NSCLC cells and enhanced paclitaxel (PTX) sensitivity in vitro and in vivo. We identified the oncogenic protein annexin 2 (ANXA2) as a potential interacting patterner of HAR1A. HAR1A overexpression enhanced ANXA2 ubiquitination and accelerated its degradation via the ubiquitin-proteasome pathway. We further uncovered that HAR1A promoted the interaction between E3 ubiquitin ligase TRIM65 and ANXA2. Moreover, the ANXA2 plasmid transfection could reverse HAR1A overexpression-induced decreases in proliferation, migration, and invasion of NSCLC cells and the activity of the NF-κB signaling pathway. Finally, we found that HAR1A loss in NSCLC might be attributed to the upregulated METTL3. The m6A modification levels of HAR1A were increased in cancer cells, while YTHDF2 was responsible for recognizing m6A modification in the HAR1A, leading to the disintegration of this lncRNA. In conclusion, we found that METTL3-mediated m6A modification decreased HAR1A in NSCLC. HAR1A deficiency, in turn, stimulated tumor growth and metastasis by activating the ANXA2/p65 axis.

Annexin A2 combined with TTK accelerates esophageal cancer progression via the Akt/mTOR signaling pathway

Annexin A2 (ANXA2) is a widely reported oncogene. However, the mechanism of ANXA2 in esophageal cancer is not fully understood. In this study, we provided evidence that ANXA2 promotes the progression of esophageal squamous cell carcinoma (ESCC) through the downstream target threonine tyrosine kinase (TTK). These results are consistent with the up-regulation of ANXA2 and TTK in ESCC. In vitro experiments by knockdown and overexpression of ANXA2 revealed that ANXA2 promotes the progression of ESCC by enhancing cancer cell proliferation, migration, and invasion. Subsequently, animal models also confirmed the role of ANXA2 in promoting the proliferation and metastasis of ESCC. Mechanistically, the ANXA2/TTK complex activates the Akt/mTOR signaling pathway and accelerates epithelial-mesenchymal transition (EMT), thereby promoting the invasion and metastasis of ESCC. Furthermore, we identified that TTK overexpression can reverse the inhibition of ESCC invasion after ANXA2 knockdown. Overall, these data indicate that the combination of ANXA2 and TTK regulates the activation of the Akt/mTOR pathway and accelerates the progression of ESCC. Therefore, the ANXA2/TTK/Akt/mTOR axis is a potential therapeutic target for ESCC.

TRPA1-PI3K/Akt-OPA1-ferroptosis axis in ozone-induced bronchial epithelial cell and lung injury

BACKGROUND

Transient receptor potential (TRP) ankyrin 1 (TRPA1) could mediate ozone-induced lung injury. Optic Atrophy 1 (OPA1) is one of the significant mitochondrial fusion proteins. Impaired mitochondrial fusion, resulting in mitochondrial dysfunction and ferroptosis, may drive the onset and progression of lung injury. In this study, we examined whether TRPA1 mediated ozone-induced bronchial epithelial cell and lung injury by activating PI3K/Akt with the involvement of OPA1, leading to ferroptosis.

METHODS

Wild-type, TRPA1-knockout (KO) mice (C57BL/6 J background) and ferrostatin-1 (Fer-1)-pretreated mice were exposed to 2.5 ppm ozone for 3 h. Human bronchial epithelial (BEAS-2B) cells were treated with 1 ppm ozone for 3 h in the presence of TRPA1 inhibitor A967079 or TRPA1-knockdown (KD) as well as pharmacological modulators of PI3K/Akt-OPA1-ferroptosis. Transcriptome was used to screen and decipher the differential gene expressions and pathways. Oxidative stress, inflammation and ferroptosis were measured together with mitochondrial morphology, function and dynamics.

RESULTS

Acute ozone exposure induced airway inflammation and airway hyperresponsiveness (AHR), reduced mitochondrial fusion, and enhanced ferroptosis in mice. Similarly, acute ozone exposure induced inflammatory responses, altered redox responses, abnormal mitochondrial structure and function, reduced mitochondrial fusion and enhanced ferroptosis in BEAS-2B cells. There were increased mitochondrial fusion, reduced inflammatory responses, decreased redox responses and ferroptosis in ozone-exposed TRPA1-KO mice and Fer-1-pretreated ozone-exposed mice. A967079 and TRPA1-KD enhanced OPA1 and prevented ferroptosis through the PI3K/Akt pathway in BEAS-2B cells. These in vitro results were further confirmed in pharmacological modulator experiments.

CONCLUSION

Exposure to ozone induces mitochondrial dysfunction in human bronchial epithelial cells and mouse lungs by activating TRPA1, which results in ferroptosis mediated via a PI3K/Akt/OPA1 axis. This supports a potential role of TRPA1 blockade in preventing the deleterious effects of ozone.

MELK promotes HCC carcinogenesis through modulating cuproptosis-related gene DLAT-mediated mitochondrial function

Cuproptosis caused by copper overload is mediated by a novel regulatory mechanism that differs from previously documented mechanisms regulating cell death. Cells dependent on mitochondrial respiration showed increased sensitivity to a copper ionophore elesclomol that induced cuproptosis. Maternal embryonic leucine zipper kinase(MELK) promotes tumorigenesis and tumor progression through the PI3K/mTOR pathway, which exerts its effects partly by targeting the pyruvate dehydrogenase complex(PDHc) and reprogramming the morphology and function of mitochondria. However, the role of MELK in cuproptosis remains unclear. Here, we validated that elevated MELK expression enhanced the activity of PI3K/mTOR signaling and subsequently promoted Dihydrolipoamide S-Acetyltransferase (DLAT) expression and stabilized mitochondrial function. This regulatory effect helped to improve mitochondrial respiration, eliminate excessive intracellular reactive oxygen species (ROS), reduce intracellular oxidative stress/damage and the possibility of mitochondria-induced cell fate alternations, and ultimately promote the progression of HCC. Meanwhile, elesclomol reduced translocase of outer mitochondrial membrane 20(TOM 20) expression and increased DLAT oligomers. Moreover, the above changes of MELK to HCC were abolished by elesclomol. In conclusion, MELK enhanced the levels of the cuproptosis-related signature(CRS) gene DLAT (especially the proportion of DLAT monomer) by activating the PI3K/mTOR pathway, thereby promoting elesclomol drug resistance, altering mitochondrial function, and ultimately promoting HCC progression.