The emerging, multifaceted role of mitophagy in cancer and cancer therapeutics

A detailed review on the role of miRNAs in mitochondrial-nuclear cross talk during cancer progression

MicroRNAs (miRNAs) are a class of small non-coding RNAs that are associated with biochemical pathways through the post-transcriptional regulation of gene expression in different cell types. Based on their expression pattern and function, miRNAs can have oncogenic and tumor suppressor activities in different cancer cells. Altered mitochondrial function and bioenergetics are known hallmarks of cancer cells. Mitochondria play a central role in metabolic reprogramming during cancer progression. Cancer cells exploit mitochondrial function for cell proliferation, invasion, migration and metastasis. Genetic and epigenetic changes in nuclear genome contribute to altered mitochondrial function and metabolic reprogramming in cancer cells. Recent studies have identified the role of miRNAs as major facilitators of anterograde and retrograde signaling between the nucleus and mitochondria in cancer cells. Detailed analysis of the miRNA-mediated regulation of mitochondrial function in cancer cells may provide new avenues for the diagnosis, prognosis, and therapeutic management of the disease. Our review aims to discuss the role of miRNAs in nuclear-mitochondrial crosstalk regulating mitochondrial functions in different cancer types. We further discussed the potential application of mitochondrial miRNAs (mitomiRs) targeting mitochondrial biogenesis and metabolism in developing novel cancer therapy.

TUBB4A Inhibits Glioma Development by Regulating ROS-PINK1/Parkin-Mitophagy Pathway

Glioma is a refractory malignant tumor with a powerful capacity for invasiveness and a poor prognosis. This study aims to investigate the role and mechanism of tubulin beta class IVA (TUBB4A) in glioma progression. The differential expression of TUBB4A in humans was obtained from databases and analyzed. Glioma cells U251-MG and U87-MG were intervened by pcDNA3.1(+) and TUBB4A overexpression plasmid. MTT, CCK8, LDH, wound healing, transwell, and western blotting were used to explore whether TUBB4A participates in the development of glioma. Reactive oxygen species (ROS) were detected by the DCFH-DA probe. Mitochondrial membrane potential (MMP) was examined by JC-1. It was found that TUBB4A expression level correlated with tumor grade, IDH1 status, 1p/19q status, and poor survival in glioma patients. In addition, TUBB4A overexpression inhibited the proliferation, migration, and invasion of U251-MG and U87-MG, while increasing the degree of apoptosis. Notably, TUBB4A overexpression promotes ROS generation and MMP depolarization, and induces mitophagy through the PINK1/Parkin pathway. Interestingly, mitochondria-targeted ROS scavenger reversed the effect of TUBB4A overexpression on PINK1/Parkin expression and mitophagy, whereas mitophagy inhibitor did not affect ROS production. And the effect of TUBB4A overexpression on mitophagy and glioma progression was consistent with that of PINK1/Parkin agonist. In conclusion, TUBB4A is a molecular marker for predicting the prognosis of glioma patients and an effective target for inhibiting glioma progression by regulating ROS-PINK1/Parkin-mitophagy pathway.

Fasting enhances the efficacy of Sorafenib in breast cancer via mitophagy mediated ROS-driven p53 pathway

The multi-kinase inhibitor sorafenib has shown potential to inhibit tumor cell growth and intra-tumoral angiogenesis by targeting several kinases, including VEGFR2 and RAF. Abnormal activation of the Ras/Raf/MAPK/ERK kinase cascade and the VEGF pathway is a common feature in breast cancer. However, the efficacy of sorafenib in breast cancer treatment remains limited. Recently, fasting has emerged as a promising non-pharmacological approach to modulate cancer metabolism and enhance the effectiveness of cancer therapies. In this study, we found that fasting significantly enhances the anti-cancer effects of sorafenib monotherapy and its combination with immunotherapy in breast cancer models without causing obvious side effects. This combined treatment effectively inhibits tumor cell proliferation and intra-tumoral angiogenesis. The fasting-induced reduction in peripheral blood glucose levels strongly correlated with enhanced sensitivity to sorafenib. Mechanistically, the combined treatment induced mitophagy, characterized by mitochondrial dysfunction and activation of the PINK1-Parkin pathway. Consequently, increased mitochondrial ROS levels promoted p53 expression, amplifying cell cycle arrest and apoptosis in breast cancer cells. Furthermore, fasting reduced lactate levels within the tumor, and the consequent glucose limitation synergized with sorafenib to activate AMPK, which in turn elevated PD-L1 expression in tumor cells, potentially enhancing their sensitivity to immunotherapy. In summary, our findings demonstrate that fasting and sorafenib, as a rational combination therapy, induce mitophagy, thereby enhancing sorafenib's efficacy in treating breast cancer through the ROS-driven p53 pathway. This study underscores the potential of fasting in breast cancer therapy and provides a foundation for optimizing the clinical application of sorafenib.

Histone lactylation regulates PRKN-Mediated mitophagy to promote M2 Macrophage polarization in bladder cancer

BACKGROUND

Bladder cancer (BCa), particularly muscle-invasive bladder cancer (MIBC), is associated with poor prognosis, partly because of immune evasion driven by M2 tumor-associated macrophages (TAMs). Understanding the regulatory mechanisms of M2 macrophage polarization via PRKN-mediated mitophagy and histone lactylation (H3K18la) is crucial for improving treatment strategies.

METHODS

A single-cell atlas from 46 human BCa samples was constructed to identify macrophage subpopulations. Bioinformatics analysis and experimental validation, including ChIP-seq and lactylation modulation assays, were used to investigate the role of PRKN in M2 macrophage polarization and its regulation by H3K18la.

RESULTS

Single-cell analysis revealed distinct macrophage subpopulations, including M1 and M2 types. PRKN was identified as a critical regulator of mitophagy in M2 macrophages, supporting their immunosuppressive function. Bulk RNA-seq and gene intersection analysis revealed a set of mitophagy-related macrophage polarization genes (Mito_Macro_RGs) enriched in mitophagy and immune pathways. Pseudotime analysis revealed that PRKN was upregulated during the M1-to-M2 transition. siRNA-mediated PRKN knockdown impaired M2 polarization, reducing the expression of CD206 and ARG1. ChIP-seq and histone lactylation modulation confirmed that H3K18la enhanced PRKN expression, promoting mitophagy and M2 polarization and thereby facilitating immune suppression and tumor progression.

CONCLUSIONS

Histone lactylation regulated PRKN-mediated mitophagy, promoting M2 macrophage polarization and contributing to immune evasion in BCa.

The role of mitochondrial biogenesis, mitochondrial dynamics and mitophagy in gastrointestinal tumors

Gastrointestinal tumors remain the leading causes of cancer-related deaths, and their morbidity and mortality remain high, which imposes a great socio-economic burden globally. Mitochondrial homeostasis depend on proper function and interaction of mitochondrial biogenesis, mitochondrial dynamics (fission and fusion) and mitophagy. Recent studies have demonstrated close implication of mitochondrial homeostasis in gastrointestinal tumorigenesis and development. In this review, we summarized the research progress on gastrointestinal tumors and mitochondrial quality control, as well as the underlying molecular mechanisms. It is anticipated that the comprehensive understanding of mitochondrial homeostasis in gastrointestinal carcinogenesis would benefit the application of mitochondria-targeted therapies for gastrointestinal tumors in future.

Mitophagy in relation to chronic inflammation/ROS in aging

Various assaults on mitochondria occur during the human aging process, contributing to mitochondrial dysfunction. This mitochondrial dysfunction is intricately connected with aging and diseases associated with it. In vivo, the accumulation of defective mitochondria can precipitate inflammatory and oxidative stress, thereby accelerating aging. Mitophagy, an essential selective autophagy process, plays a crucial role in managing mitochondrial quality control and homeostasis. It is a highly specialized mechanism that systematically removes damaged or impaired mitochondria from cells, ensuring their optimal functioning and survival. By engaging in mitophagy, cells are able to maintain a balanced and stable environment, free from the potentially harmful effects of dysfunctional mitochondria. An ever-growing body of research highlights the significance of mitophagy in both aging and age-related diseases. Nonetheless, the association between mitophagy and inflammation or oxidative stress induced by mitochondrial dysfunction remains ambiguous. We review the fundamental mechanisms of mitophagy in this paper, delve into its relationship with age-related stress, and propose suggestions for future research directions.

Icariside II relieves radiation enteritis by regulating PINK/Parkin-mediated mitophagy

Radiation enteritis (RE) is one of the major side effects of radiotherapy. So far, there are no effective drugs for preventing the disease process. Icariside II (ICS II) is a highly efficient monomer compound extracted and purified from the classic Chinese medicinal herb Epimedium. It has anti-inflammatory, antioxidant, and immunomodulatory effects. However, the role and mechanism of ICS II on radiation enteritis are not clear. Here, we reveal the role of ICS II in radiation enteritis by using an irradiation-induced rat model and a human colorectal cancer cell (CaCo2). After intragastric administration, HE staining and Tunel staining to observe the histopathological changes in the colon, and TEM to observe the ultrastructure of mitochondria; The antioxidant indexes and mitochondrial function-related markers of colon tissues were determined; DCFH-DA fluorescent probe were used to detect the cellular ROS level, JC-1 staining was used to detect the changes in mitochondrial membrane potential, and Western Blot was used to detect related protein expression. The results showed that ICS II could reduce intestinal injury and attenuate the radiation-induced oxidative stress and inflammatory response. In addition, ICS II could effectively attenuate mitochondrial damage and activate mitochondrial autophagy in rats. Mechanistically, ICS II activates mitochondrial autophagy-related protein expression to rescue radiation-induced damage to mitophagy. We found that by inhibiting mitophagy, the therapeutic effect of ICS II can be eliminated and our data suggest that ICS II may be a new and effective drug candidate for the treatment of radiation enteritis.

An Integrated Approach Utilizing Single-Cell and Bulk RNA-Sequencing for the Identification of a Mitophagy-Associated Genes Signature: Implications for Prognostication and Therapeutic Stratification in Prostate Cancer

Introduction: Prostate cancer, notably prostate adenocarcinoma (PARD), has high incidence and mortality rates. Although typically resistant to immunotherapy, recent studies have found immune targets for prostate cancer. Stratifying patients by molecular subtypes may identify those who could benefit from immunotherapy. Methods: We used single-cell and bulk RNA sequencing data from GEO and TCGA databases. We characterized the tumor microenvironment at the single-cell level, analyzing cell interactions and identifying fibroblasts linked to mitophagy. Target genes were narrowed down at the bulk transcriptome level to construct a PARD prognosis prediction nomogram. Unsupervised consensus clustering classified PARD into subtypes, analyzing differences in clinical features, immune infiltration, and immunotherapy. Furthermore, the cellular functions of the genes of interest were verified in vitro. Results: We identified ten cell types and 160 mitophagy-related single-cell differentially expressed genes (MR-scDEGs). Strong interactions were observed between fibroblasts, endothelial cells, CD8+ T cells, and NK cells. Fibroblasts linked to mitophagy were divided into six subtypes. Intersection of DEGs from three bulk datasets with MR-scDEGs identified 26 key genes clustered into two subgroups. COX regression analysis identified seven prognostic key genes, enabling a prognostic nomogram model. High and low-risk groups showed significant differences in clinical features, immune infiltration, immunotherapy, and drug sensitivity. In prostate cancer cell lines, CAV1, PALLD, and ITGB8 are upregulated, while CLDN7 is downregulated. Knockdown of PALLD significantly inhibits the proliferation and colony-forming ability of PC3 and DU145 cells, suggesting the important roles of this gene in prostate cancer progression. Conclusions: This study analyzed mitophagy-related genes in PARD, predicting prognosis and aiding in subtype identification and immunotherapy response analysis. This approach offers new strategies for treating prostate cancer with specific molecular subtypes and helps develop potential biomarkers for personalized medicine strategies.

Molecular regulation of mitophagy signaling in tumor microenvironment and its targeting for cancer therapy

Aberrations emerging in mitochondrial homeostasis are restrained by mitophagy to control mitochondrial integrity, bioenergetics signaling, metabolism, oxidative stress, and apoptosis. The mitophagy-accompanied mitochondrial processes that occur in a dysregulated condition act as drivers for cancer occurrence. In addition, the enigmatic nature of mitophagy in cancer cells modulates the cellular proteome, creating challenges for therapeutic interventions. Several reports found the role of cellular signaling pathways in cancer to modulate mitophagy to mitigate stress, immune checkpoints, energy demand, and cell death. Thus, targeting mitophagy to hinder oncogenic intracellular signaling by promoting apoptosis, in hindsight, might have an edge against cancer. This review highlights the receptors and adaptors, and the involvement of many proteins in mitophagy and their role in oncogenesis. It also provides insight into using mitophagy as a potential target for therapeutic intervention in various cancer types.

The interconnective role of the UPS and autophagy in the quality control of cancer mitochondria

Uncontrollable cancer cell growth is characterized by the maintenance of cellular homeostasis through the continuous accumulation of misfolded proteins and damaged organelles. This review delineates the roles of two complementary and synergistic degradation systems, the ubiquitin-proteasome system (UPS) and the autophagy-lysosome system, in the degradation of misfolded proteins and damaged organelles for intracellular recycling. We emphasize the interconnected decision-making processes of degradation systems in maintaining cellular homeostasis, such as the biophysical state of substrates, receptor oligomerization potentials (e.g., p62), and compartmentalization capacities (e.g., membrane structures). Mitochondria, the cellular hubs for respiration and metabolism, are implicated in tumorigenesis. In the subsequent sections, we thoroughly examine the mechanisms of mitochondrial quality control (MQC) in preserving mitochondrial homeostasis in human cells. Notably, we explored the relationships between mitochondrial dynamics (fusion and fission) and various MQC processes-including the UPS, mitochondrial proteases, and mitophagy-in the context of mitochondrial repair and degradation pathways. Finally, we assessed the potential of targeting MQC (including UPS, mitochondrial molecular chaperones, mitochondrial proteases, mitochondrial dynamics, mitophagy and mitochondrial biogenesis) as cancer therapeutic strategies. Understanding the mechanisms underlying mitochondrial homeostasis may offer novel insights for future cancer therapies.

The role of mitophagy-related genes in prognosis and immunotherapy of cutaneous melanoma: a comprehensive analysis based on single-cell RNA sequencing and machine learning

Mitophagy, the selective degradation of mitochondria by autophagy, plays a crucial role in cancer progression and therapy response. This study aims to elucidate the role of mitophagy-related genes (MRGs) in cutaneous melanoma (CM) through single-cell RNA sequencing (scRNA-seq) and machine learning approaches, ultimately developing a predictive model for patient prognosis. The scRNA-seq data, bulk transcriptomic data, and clinical data of CM were obtained from publicly available databases. The single-sample gene set enrichment analysis (ssGSEA) and weighted gene co-expression network analysis (WGCNA) were used to identify gene modules associated with mitophagy phenotypes. A machine learning framework employing ten different algorithms was used to develop the prognostic model. Based on scRNA-seq data, we identified 16 distinct cell subpopulations in melanoma, and melanoma cells exhibited significantly higher mitophagy scores. The turquoise module identified via WGCNA showed the strongest correlation with mitophagy scores. A prognostic model incorporating seven genes was developed through machine learning algorithms, achieving an average C-index of 0.754 across training and validation cohorts. Functionally, low-risk patients were enriched in interferon-gamma response and inflammatory processes, whereas high-risk patients showed enrichment in glycolysis regulation and signaling pathways such as KRAS and Wnt/β-catenin. Notably, low-risk patients demonstrated enhanced immune infiltration and greater sensitivity to immunotherapy. RT-qPCR validated the expression level of 7 model genes in human melanoma cell lines and normal melanocyte cell lines. Our study provides a comprehensive understanding of MRGs in melanoma and presents a novel prognostic model. These findings enhance our understanding of the tumor microenvironment and may guide personalized treatment strategies for CM patients.

A Multi-Omics Analysis of a Mitophagy-Related Signature in Pan-Cancer

Mitophagy, an essential process within cellular autophagy, has a critical role in regulating key cellular functions such as reproduction, metabolism, and apoptosis. Its involvement in tumor development is complex and influenced by the cellular environment. Here, we conduct a comprehensive analysis of a mitophagy-related gene signature, composed of PRKN, PINK1, MAP1LC3A, SRC, BNIP3L, BECN1, and OPTN, across various cancer types, revealing significant differential expression patterns associated with molecular subtypes, stages, and patient outcomes. Pathway analysis revealed a complex interplay between the expression of the signature and potential effects on the activity of various cancer-related pathways in pan-cancer. Immune infiltration analysis linked the mitophagy signature with certain immune cell types, particularly OPTN with immune infiltration in melanoma. Methylation patterns correlated with gene expression and immune infiltration. Mutation analysis also showed frequent alterations in PRKN (34%), OPTN (21%), PINK1 (28%), and SRC (15%), with implications for the tumor microenvironment. We also found various correlations between the expression of the mitophagy-related genes and sensitivity in different drugs, suggesting that targeting this signature could improve therapy efficacy. Overall, our findings underscore the importance of mitophagy in cancer biology and drug resistance, as well as its potential for informing treatment strategies.

A potential therapeutic approach for ulcerative colitis: targeted regulation of mitochondrial dynamics and mitophagy through phytochemicals

Mitochondria are important organelles that regulate cellular energy and biosynthesis, as well as maintain the body's response to environmental stress. Their dynamics and autophagy influence occurrence of cellular function, particularly under stressful conditions. They can generate reactive oxygen species (ROS) which is a major contributor to inflammatory diseases such as ulcerative colitis (UC). In this review, we discuss the key effects of mitochondrial dynamics and mitophagy on the pathogenesis of UC, with a particular focus on the cellular energy metabolism, oxidative stress, apoptosis, and immunoinflammatory activities. The therapeutic efficacy of existing drugs and phytochemicals targeting the mitochondrial pathway are discussed to reveal important insights for developing therapeutic strategies for treating UC. In addition, new molecular checkpoints with therapeutic potential are identified. We show that the integration of mitochondrial biology with the clinical aspects of UC may generate ideas for enhancing the clinical management of UC.

Identification of a mitophagy-related gene signature for predicting overall survival and response to immunotherapy in rectal cancer

BACKGROUND

Rectal cancer is a highly heterogeneous gastrointestinal tumor, and the prognosis for patients with treatment-resistant and metastatic rectal cancer remains poor. Mitophagy, a type of selective autophagy that targets mitochondria, plays a role in promoting or inhibiting tumors; however, the importance of mitophagy-related genes (MRGs) in the prognosis and treatment of rectal cancer is unclear.

METHODS

In this study, we used the differentially expressed genes (DEGs) and MRGs from the TCGA-READ dataset to identify differentially expressed mitophagy-related genes (MRDEGs). The mitophagy scores were then analyzed for differential expression and ROC. Seven module genes were identified using the weighted gene coexpression network analysis (WGCNA) approach and subsequently validated in the merged datasets GSE87211 and GSE90627. The model genes were obtained based on prognostic features, and the subgroups were distinguished by risk score. Gene enrichment, immune infiltration and immunotherapy response were also evaluated. Finally, validation of prognostic gene expression in rectal cancer was carried out using clinical samples, employing Immunohistochemistry (IHC).

RESULTS

We demonstrated that 22 MRGs were differentially expressed between normal and rectal cancer tissues. A prognostic model for rectal cancer MRGs was constructed using WGCNA and Cox regression, which exhibited good diagnostic performance. In this study, we identified four molecular markers (MYLK, FLNC, MYH11, and NEXN) as potential prognostic biomarkers for rectal cancer for the first time. Moreover, our findings indicate that the risk scores derived from the four MRGs are associated with tumor immunity. To further validate our findings, IHC analyses suggested that the expression of MYH11 in rectal cancer tissues was lower than in nontumorous rectal tissues.

CONCLUSION

MRGs could predict the prognosis and response to immunotherapy in patients with rectal cancer and might be able to personalize treatment for patients.

Microplastics accumulated in breast cancer patients lead to mitophagy via ANXA2-mediated endocytosis and IL-17 signaling pathway

Breast cancer (BC) is the most common malignancy in women and the leading cause of cancer death. Microplastics (MPs) are plastic fragments with a diameter of less than 5 mm, easily ingested by organisms. Although MPs have been reported to enter the human body through diet, surgery, etc., whether MPs accumulate in BC and their effects have been largely unknown. Our study revealed a significant accumulation of MPs in BC patient samples. MPs pull-down experiments and mass spectrometry (MS) studies showed that MPs bound to annexin A2 (ANXA2) and were endocytosed into cells. This process resulted in mitochondrial damage and subsequent induction of mitophagy. Furthermore, after binding to ANXA2, MPs regulated mitophagy by inhibiting IL-17 exocytosis. These findings revealed the mechanism of toxic effects of MPs in patients with BC, clarified the molecular mechanism of ANXA2-IL-17 signaling pathway causing mitochondrial damage by MPs, and suggested the potential toxic effects and toxicological mechanisms of MPs.

Autophagy in cancer development, immune evasion, and drug resistance

Macroautophagy/autophagy is a highly conserved evolutionary mechanism involving lysosomes for the degradation of cytoplasmic components including organelles. The constitutive, basal level of autophagy is fundamental for preserving cellular homeostasis; however, alterations in autophagy can cause disease pathogenesis, including cancer. The role of autophagy in cancer is particularly complicated, since this process acts both as a tumor suppressor in precancerous stages but facilitates tumor progression during carcinogenesis and later stages of cancer progression. This shift between anti-tumor and pro-tumor roles may be influenced by genetic and environmental factors modulating key pathways such as those involving autophagy-related proteins, the PI3K-AKT-MTOR axis, and AMPK, which often show dysregulation in tumors. Autophagy regulates various cellular functions, including metabolism of glucose, glutamine, and lipids, cell proliferation, metastasis, and several types of cell death (apoptosis, ferroptosis, necroptosis and immunogenic cell death). These multifaceted roles demonstrate the potential of autophagy to affect DNA damage repair, cell death pathways, proliferation and survival, which are critical in determining cancer cells' response to chemotherapy. Therefore, targeting autophagy pathways presents a promising strategy to combat chemoresistance, as one of the major reasons for the failure in cancer patient treatment. Furthermore, autophagy modulates immune evasion and the function of immune cells such as T cells and dendritic cells, influencing the tumor microenvironment and cancer's biological behavior. However, the therapeutic targeting of autophagy is complex due to its dual role in promoting survival and inducing cell death in cancer cells, highlighting the need for strategies that consider both the beneficial and detrimental effects of autophagy modulation in cancer therapy. Hence, both inducers and inhibitors of autophagy have been introduced for the treatment of cancer. This review emphasizes the intricate interplay between autophagy, tumor biology, and immune responses, offering insights into potential therapeutic approaches that deploy autophagy in the cancer suppression.

Hypoxia-induced BNIP3 facilitates the progression and metastasis of uveal melanoma by driving metabolic reprogramming

Uveal melanoma (UM) is an aggressive intraocular malignancy derived from melanocytes in the uvea tract of the eye. Up to 50% of patients with UM develop distant metastases which is usually fatal within one year; preventing metastases is therefore essential. Metabolic reprogramming plays a critical role in UM progression and metastasis. However, the metabolic phenotype of UM cells in the hypoxic tumor is not well understood. Here, we report that hypoxia-induced BNIP3 reprograms tumor cell metabolism, promoting their survival and metastasis. In response to hypoxia, BNIP3-mediated mitophagy alleviates mitochondrial dysfunction and enhances mitochondrial oxidative phosphorylation (OXPHOS) while simultaneously reducing mitochondrial reactive oxygen species (mtROS) production. This, in turn, impairs HIF1A/HIF-1α protein stability and inhibits glycolysis. Inhibition of mitophagy significantly suppresses BNIP3-induced UM progression and metastasis in vitro and in vivo. Collectively, these observations demonstrate a novel mechanism whereby BNIP3 promotes UM metabolic reprogramming and malignant progression by mediating hypoxia-induced mitophagy and suggest that BNIP3 could be an important therapeutic target to prevent metastasis in patients with UM.Abbreviations: AOD: average optical density; BNIP3: BCL2/adenovirus E1B interacting protein 3; CQ: chloroquine; CoCl2: cobalt chloride; GEPIA: Gene Expression Profiling Interactive Analysis; HIF1A: hypoxia inducible factor 1, alpha subunit; IHC: immunohistochemistry; mtROS: mitochondrial reactive oxygen species; NAC: N-acetylcysteine; OCR: oxygen consumption rate; OXPHOS: oxidative phosphorylation; ROS: reactive oxygen species; TCGA: The Cancer Genome Atlas; UM: uveal melanoma.

Deciphering glioblastoma pathogenesis: Insights from mitophagy dysregulation and SNX7 as a therapeutic target

BACKGROUND

Glioblastoma is a highly aggressive and invasive brain tumor with an extremely poor prognosis. The aims of the present study are to investigate the pathogenesis of glioblastoma and identify potential therapeutic targets.

METHODS

We performed a systematic analysis of gene expression data from multiple datasets, including GEO and TCGA, to identify hub genes and pathways associated with glioblastoma progression. Bioinformatics tools were utilized to analyze differential gene expression, pathway enrichment and survival prognosis. Both in vitro and in vivo functional experiments were conducted to validate biological roles of SNX7.

RESULTS

Pathway analysis revealed significant enrichment of the mitophagy pathway in glioblastoma, indicating its critical role in tumor development. We identified 12 hub genes associated with glioblastoma prognosis, with high-risk patients having worse survival outcomes. Among the hub gene set, sorting nexin 7 (SNX7) was found to be the most significant regulator of glioblastoma progression. Our results also demonstrated that SNX7 expression is associated with tumor ferroptosis and genomic variations, representing potential biomarkers for clinical diagnosis and treatment. Furthermore, functional experiments confirmed that SNX7 promotes glioblastoma cell proliferation, invasion and survival by inhibiting protective mitophagy.

CONCLUSION

Our results highlight the importance of mitophagy dysregulation in the pathogenesis of glioblastoma and identify SNX7 as a novel therapeutic target. Further research is needed to elucidate the underlying mechanisms of SNX7 in glioblastoma and validate its clinical significance. These findings may facilitate the development of personalized treatment strategies and improve outcomes for glioblastoma patients.

New insights into the role of mitophagy related gene affecting the metastasis of osteosarcoma through scRNA-seq and CRISPR-Cas9 genome editing

BACKGROUND

Osteosarcoma (OSA), the most common primary bone malignancy, poses significant challenges due to its aggressive nature and propensity for metastasis, especially in adolescents. Mitophagy analysis can help identify new therapeutic targets and combined treatment strategies.

METHODS

This study integrates single-cell sequencing (scRNA-seq) data and bulk-seq to identify mitophagy-related genes (MRGs) associated with the progression of OSA metastasis and analyze their clinical significance. scRNA-seq data elucidates the relationship between mitophagy and OSA metastasis, employing "CellChat" R package to explore intercellular communications and report on hundreds of ligand-receptor interactions. Subsequently, the combination of bulk-seq and CRISPR-Cas9 gene editing identifies mitophagy-related biomarker associated with metastatic prognosis. Finally, validation of the relationship between mitophagy and OSA metastasis is achieved through cellular biology experiments and animal studies.

RESULTS

The distinct mitophagy activity of various mitochondria manifests in diverse spatial localization, cellular developmental trajectories, and intercellular interactions. OSA tissue exhibits notable heterogeneity in mitophagy within osteoblastic OSA cells. However, high mitophagy activity correlates consistently with high metastatic potential. Subsequently, we identified three critical genes associated with mitophagy in OSA, namely RPS27A, TOMM20 and UBB. According to the aforementioned queue of genes, we have constructed a mitophagy_score (MIP_score). We observed that it consistently predicts patient prognosis in both internal and external datasets, demonstrating strong robustness and stability. Furthermore, we have found that MIP_score can also guide chemotherapy, with varying sensitivities to chemotherapeutic agents based on different MIP_score. It is noteworthy that, through the integration of CRISPR-Cas9 genome-wide screening and validation via cellular and animal experiments, we have identified RPS27A as a potential novel biomarker for OSA.

CONCLUSIONS

Our comprehensive analysis elucidated the profile of mitophagy throughout the OSA metastasis process, forming the basis for a mitophagy-related prognostic model that addresses clinical outcomes and drug sensitivity following OSA metastasis. Additionally, an online interactive platform was established to assist clinicians in decision-making ( https://mip-score.shinyapps.io/labtan/ ). These findings lay the groundwork for developing targeted therapies aimed at improving the prognosis of OSA patients.

MARCH5 Promotes the Progression of Thyroid cancer by Regulating Mitochondrial Autophagy Protein FUNDC1-mediated Pyroptosis

MARCH5 is a key regulatory factor in mitochondria. However, the expression and function of MARCH5 in thyroid cancer (TC) are not yet clear. The research explores the role and the potential mechanism of MARCH5 in the tumorigenesis of TC. MARCH5 expression were measured by qRT-PCR and Western blot. CCK-8 kits were used to measure the cell viability. Cell scratch assay and Tanswell assay were used to measure cell migration and invasion, respectively. The pyroptosis related proteins (NLRP3, caspase-1, GSDMD) and mitochondrial autophagy related proteins (LC3-II, p62, parkin, pink1) were detected. The mitochondrial ROS GSH, MDA, and SOD were detected using commercial kits. Finally, a TC mouse model was constructed to detect the role of MARCH5 in tumor growth in vivo. The results displayed that the expression of MARCH5 was increased in TC patients and cells, and was significantly correlated with prognosis. Functional studies have found that MARCH5 inhibits oxidative stress levels and mitochondrial autophagy in TPC-1 cells. Further research has found that MARCH5 promotes the progression of thyroid cancer by degrading FUNDC1 and inhibiting the mitochondrial autophagy mediated pyroptosis pathway, regulating cell proliferation, migration, and invasion in TPC-1 cells. More importantly, interference with MARCH5 inhibits tumor growth and further development of TC in vivo. In conclusion, MARCH5 promotes the progression of thyroid cancer by degrading FUNDC1 and inhibiting the mitochondrial autophagy mediated pyroptosis, regulating cell proliferation, migration, and invasion. This study provides new theoretical basis for the treatment and prevention of TC in clinical practice.

Ailanthone blocks mitophagy to promote mtDNA leakage through BAX-BAK1 pores and suppress hepatocellular carcinoma cell proliferation

Introduction

Hepatocellular carcinoma (HCC), the third leading cancer mortality worldwide, shows rising incidence. The mitochondria in HCC cells are prone to damage from metabolic stress and oxidative stress, necessitating heightened mitophagy for mitochondrial homeostasis and cell survival. Thus, mitophagy inhibition is a promising HCC therapy. The traditional Chinese medicinal herb ailanthone have proved promote mitochondrial dysfunction and inhibits HCC. However, the underlying mechanism remains unclear.

Methods

CCK8 assay was applied to detect the proliferation. JC-1, MitoTracker Red/Green and MitoSOX staining were applied to detect the mitochondrial homeostasis. Inflammatory factors were analysed via ELISA and WB assay. Mitochondria and cytoplasm separation, genome extraction and qPCR were used to detect mitochondrial DNA (mtDNA) leakage. Mitochondria ultrastructure was detected by transmission electron microscopy. WB and IHC experiments were applied to detect protein expression. Protein-protein interactions detected by immunoprecipitation and immunofluorescence imaging. The in vivo antitumor effect was validated by the xenograft mouse model.

Results

In this study, we demonstrated the potent anti-HCC properties of ailanthone and revealed its molecular mechanism. In vitro studies demonstrated that ailanthone effectively inhibited PINK1-PRKN mediated mitophagy and promoted BAX-BAK1 mitochondrial pores formation through PRKN inhibition. This process led to the mitochondrial mtDNA leakage into the cytoplasm, which subsequently triggered the induction of inflammatory factors. The inhibition of mitophagy and the activation of inflammatory response ultimately led to HCC proliferation inhibition. In vivo studies demonstrated that ailanthone exhibited stronger anti-HCC activity than 5-Fluorouracil (5-FU), with no significant adverse effects on animal body weight or the physiological functions of vital organs.

Conclusion

This study highlighted the efficacy of ailanthone against HCC and elucidated its underlying molecular mechanisms, suggesting the promising therapeutic potential of ailanthone for HCC.

BNIP3 Downregulation Ameliorates Muscle Atrophy in Cancer Cachexia

BACKGROUND AND AIMS

Cancer cachexia is a complex syndrome affecting most cancer patients and is directly responsible for about 20% of cancer-related deaths. Previous studies showed muscle proteolysis hyper-activation and mitophagy induction in tumor-bearing animals. While basal mitophagy is required for maintaining muscle mass and quality, excessive mitophagy promotes uncontrolled protein degradation, muscle loss and impaired function. BNIP3, a key mitophagy-related protein, is significantly increased in the muscles of both mice and human cancer hosts. This study aimed to define the potential of mitigating mitophagy via BNIP3 downregulation in preserving mitochondrial integrity, counteracting skeletal muscle loss in experimental cancer cachexia.

METHODS

Two in vivo gene delivery methods were performed to knock down muscle BNIP3: electroporation of a BNIP3-specific shRNA expression vector or adenovirus injection.

RESULTS

The electroporation effectively reduced muscle BNIP3 in healthy mice but was ineffective in C26 tumor-bearing mice. In contrast, adenovirus-mediated BNIP3 knockdown successfully decreased BNIP3 levels also in tumor hosts. Although BNIP3 knockdown did not impact overall on body or muscle mass, it improved muscle fiber size in C26-bearing miceh2, suggesting partial prevention of muscle atrophy. Mitochondrial respiratory chain complexes (OxPhos) and TOM20 protein levels were consistently rescued, indicating improvements in mitochondrial mass, while H2O2 levels were unchanged among the groups, suggesting that BNIP3 downregulation does not impair the endogenous control of oxidative balance.

CONCLUSIONS

These findings suggest that a fine balance between mitochondrial disposal and biogenesis is fundamental for preserving muscle homeostasis and highlight a potential role for BNIP3 modulation against cancer-induced muscle wasting.

The Role and Applied Value of Mitochondria in Glioma-Related Research

Mitochondria, known as the "energy factory" of cells, are essential organelles with a double membrane structure and genetic material found in most eukaryotic cells. They play a crucial role in tumorigenesis and development, with alterations in mitochondrial structure and function in tumor cells leading to characteristics such as rapid proliferation, invasion, and drug resistance. Glioma, the most common brain tumor with a high recurrence rate and limited treatment options, has been linked to changes in mitochondrial structure and function. This review focuses on the bioenergetics, dynamics, metastasis, and autophagy of mitochondria in relation to glioma proliferation, as well as the potential use of mitochondria-targeting drugs in glioma treatment.

Association between BCL2 interacting protein 3 like (BNIP3L) genetic polymorphisms and the risk of multiple myeloma in China

BACKGROUND

The BCL2 interacting protein 3-like (BNIP3L) protein is involved in multiple myeloma (MM) development and progression. This study aims to explore the connection between BNIP3L single-nucleotide polymorphisms (SNPs) and MM.

METHODS

SNaPshot was used to examine six SNP loci of the BNIP3L gene in enrolled subjects. The relationship between these loci and MM susceptibility and prognosis was explored. Survival analysis was used to evaluate the impact of different factors on patient survival.

RESULTS

The rs2874670 AA genotype and A allele were associated with increased MM risk (P < 0.05). The CCACAC haplotype had a higher frequency in MM, while CCGCAC had a higher frequency in normal patients (all P < 0.05). Patients with R-ISS stage I and II had higher survival rates than those with stage III (P < 0.05). Patients, who received chemotherapy followed by autologous stem cell transplantation, had longer survival time than those who only received chemotherapy (P < 0.05). Low levels of LDH and β2-MG were associated with better survival rates (P < 0.05). Cox regression identified that LDH levels, β2-MG levels, and R-ISS staging were the risk factors for the death of MM. Mann-Whitney U test found a significant difference in survival time between MM patients with different BNIP3L rs2874670 genotypes after BD chemotherapy (P < 0.05).

CONCLUSION

To our knowledge, this is the first study to find that BNIP3L rs2874670 could increase MM susceptibility in China. Different BNIP3L rs2874670 genotypes may affect the prognosis of MM patients receiving BD chemotherapy.

Advances in research on the relationship between mitochondrial function and colorectal cancer: a bibliometric study from 2013 to 2023

The study provides a thorough examination of literature from 2013 to 2023, delving into the intricate relationship between mitochondrial function and colorectal cancer (CRC). It offers a concise overview of the current landscape and emerging trends in this rapidly evolving research area. The findings indicate a consistent rise in annual publications, reflecting growing interest and significant potential in the field. China emerges as the leading contributor, followed by the United States and India. However, despite China's dominance in output, its average citation rate is lower than that of the US, which leads in citations per publication, highlighting a noticeable disparity. In the realm of research institutions, Shanghai Jiao Tong University and China Medical University are identified as major contributors, yet the potential for inter-institutional collaboration remains largely untapped, suggesting avenues for future synergy. Internationally, China-US collaborations are particularly robust, fostering cross-border knowledge exchange. Hyun Jin Won and Li Wei are recognized as prolific authors, while Ahmedin Jemal is an influential co-cited scholar, noted for his seminal contributions. Keyword analysis reveals research focus areas, such as the complex CRC tumor microenvironment, molecular mechanisms of oxidative stress, and key multidrug resistance pathways. It also highlights the promising potential of mitochondria-targeted therapies and nanomolecular technologies in clinical practice, signaling their growing significance in addressing complex health challenges. The study underscores the imperative to validate complex mitochondrial mechanisms and signaling pathways in CRC, with a particular emphasis on translating these insights into drug targets for clinical trials. Advancing this research is expected to refine and enhance CRC treatment strategies. Additionally, it highlights the urgency of validating mitochondrial complexities in CRC, advocating for collaborative efforts to link these mechanisms with tailored therapeutic interventions for clinical testing. This integrated approach promises significant advancements in developing effective, targeted CRC treatments, ultimately improving patient outcomes.

Single-cell sequencing unveils mitophagy-related prognostic model for triple-negative breast cancer

Background

Triple-negative breast cancer (TNBC) is an aggressive subtype of breast cancer lacking hormone receptors and HER2 expression, leading to limited treatment options and poor prognosis. Mitophagy, a selective autophagy process targeting damaged mitochondria, plays a complex role in cancer progression, yet its prognostic significance in TNBC is not well understood.

Methods

This study utilized single-cell RNA sequencing data from the TCGA and GEO databases to identify mitophagy-related genes (MRGs) associated with TNBC. A prognostic model was developed using univariate Cox analysis and LASSO regression. The model was validated across multiple independent cohorts, and correlations between MRG expression, immune infiltration, and drug sensitivity were explored.

Results

Nine key MRGs were identified and used to stratify TNBC patients into high-risk and low-risk groups, with the high-risk group showing significantly worse survival outcomes. The model demonstrated strong predictive accuracy across various datasets. Additionally, the study revealed a correlation between higher MRG expression levels and increased immune cell infiltration, as well as potential responsiveness to specific chemotherapeutic agents.

Conclusion

The mitophagy-related prognostic model offers a novel method for predicting outcomes in TNBC patients and highlights the role of mitophagy in influencing the tumor microenvironment, with potential applications in personalized treatment strategies.

Signal-Sustained Imaging of Mitophagy with an Enzyme-Activatable Metabolic Lipid Labeling Probe

Imaging of mitophagy is of significance as aberrant mitophagy is engaged in multiple diseases. Mitophagy has been imaged with synthetic or biotic pH sensors by reporting pH acidification en route delivery into lysosomes. To circumvent uncertainty of acidity-dependent signals, we herein report an enzyme-activatable probe covalently attached on mitochondrial inner membrane (ECAM) for signal-persist mitophagy imaging. ECAM is operated via ΔΨm-driven accumulation of Mito-proGreen in mitochondria and covalent linking of the trapped probe with azidophospholipids metabolically incorporated into the mitochondrial inner membrane. Upon mitophagy, ECAM is delivered into lysosomes and hydrolyzed by LNPEP/leucyl aminopeptidase, yielding turn-on green fluorescence that is immune to lysosomal acidity changes and stably retained in fixed cells. With ECAM, phorbol-12-myristate-13-acetate (PMA) was identified as a highly potent inducer of mitophagy. Overcoming signal susceptibility of pH probes and liability of ΔΨm probes to dissipation from stressed mitochondria, ECAM offers an attractive tool to study mitophagy and mitophagy-inducing therapeutic agents.Abbreviations: Baf-A1, bafilomycin A1; CCCP, carbonyl cyanide m-chlorophenylhydrazone; DBCO, dibenzocyclooctyne; ECAM, enzyme-activated probe covalently attached on mitochondrial inner membrane; GFP, green fluorescent protein; LAMP2, lysosomal associated membrane protein 2; LNPEP/LAP, leucyl and cystinyl aminopeptidase; PMA, phorbol-12-myristate-13-acetate; ΔΨm, mitochondrial transmembrane potential; RFP, red fluorescent protein; TPP, triphenylphosphonium.

Mitophagy: insights into its signaling molecules, biological functions, and therapeutic potential in breast cancer

Mitophagy, a form of selective autophagy that removes damaged or dysfunctional mitochondria, plays a crucial role in maintaining mitochondrial and cellular homeostasis. Recent findings suggest that defective mitophagy is closely associated with various diseases, including breast cancer. Moreover, a better understanding of the multifaceted roles of mitophagy in breast cancer progression is crucial for the treatment of this disease. Here, we will summarize the molecular mechanisms of mitophagy process. In addition, we highlight the expression patterns and roles of mitophagy-related signaling molecules in breast cancer progression and the potential implications of mitophagy for the development of breast cancer, aiming to provide better therapeutic strategies for breast cancer treatment.

RABIF promotes hepatocellular carcinoma progression through regulation of mitophagy and glycolysis

The RAB interacting factor (RABIF) is a putative guanine nucleotide exchange factor that also functions as a RAB-stabilizing holdase chaperone. It has been implicated in pathogenesis of several cancers. However, the functional role and molecular mechanism of RABIF in hepatocellular carcinoma (HCC) are not entirely known. Here, we demonstrate an upregulation of RABIF in patients with HCC, correlating with a poor prognosis. RABIF inhibition results in decreased HCC cell growth both in vitro and in vivo. Our study reveals that depleting RABIF attenuates the STOML2-PARL-PGAM5 axis-mediated mitophagy. Consequently, this reduction in mitophagy results in diminished mitochondrial reactive oxygen species (mitoROS) production, thereby alleviating the HIF1α-mediated downregulation of glycolytic genes HK1, HKDC1, and LDHB. Additionally, we illustrate that RABIF regulates glucose uptake by controlling RAB10 expression. Importantly, the knockout of RABIF or blockade of mitophagy sensitizes HCC cells to sorafenib. This study uncovers a previously unrecognized role of RABIF crucial for HCC growth and identifies it as a potential therapeutic target.

The tumor suppressor Parkin exerts anticancer effects through regulating mitochondrial GAPDH activity

Cancer cells preferentially utilize glycolysis for energy production, and GAPDH is a critical enzyme in glycolysis. Parkin is a tumor suppressor and a key protein involved in mitophagy regulation. However, the tumor suppression mechanism of Parkin has still not been elucidated. In this study, we identified mitochondrial GAPDH as a new substrate of the E3 ubiquitin ligase Parkin, which mediated GAPDH ubiquitination in human cervical cancer. The translocation of GAPDH into mitochondria was driven by the PINK1 kinase, and either PINK1 or GAPDH mutation prevented the accumulation of GAPDH in mitochondria. Parkin caused the ubiquitination of GAPDH at multiple sites (K186, K215, and K219) located within the enzyme-catalyzed binding domain of the GAPDH protein. GAPDH ubiquitination was required for mitophagy, and stimulation of mitophagy suppressed cervical cancer cell growth, indicating that mitophagy serves as a type of cell death. Mechanistically, PHB2 served as a key mediator in GAPDH ubiquitination-induced mitophagy through stabilizing PINK1 protein and GAPDH mutation resulted in the reduced distribution of PHB2 in mitophagic vacuole. In addition, ubiquitination of GAPDH decreased its phosphorylation level and enzyme activity and inhibited the glycolytic pathway in cervical cancer cells. The results of in vivo experiments also showed that the GAPDH mutation increased glycolysis in cervical cancer cells and accelerated tumorigenesis. Thus, we concluded that Parkin may exert its anticancer function by ubiquitinating GAPDH in mitochondria. Taken together, our study further clarified the molecular mechanism of tumor suppression by Parkin through the regulation of energy metabolism, which provides an experimental basis for the development of new drugs for the treatment of human cervical cancer.

Machine learning and single-cell analysis identify the mitophagy-associated gene TOMM22 as a potential diagnostic biomarker for intervertebral disc degeneration

Background

Mitophagy selectively eliminates potentially cytotoxic and damaged mitochondria and effectively prevents excessive cytotoxicity from damaged mitochondria, thereby attenuating inflammatory and oxidative responses. However, the potential role of mitophagy in intervertebral disc degeneration remains to be elucidated.

Methods

The GSVA method, two machine learning methods (SVM-RFE algorithm and random forest), the CIBERSORT and MCPcounter methods, as well as the consensus clustering method and the WGCNA algorithm were used to analyze the involvement of mitophagy in intervertebral disc degeneration, the diagnostic value of mitophagy-associated genes in intervertebral disc degeneration, and the infiltration of immune cells, and identify the gene modules that were closely related to mitophagy. Single-cell analysis was used to detect mitophagy scores and TOMM22 expression, and pseudo-temporal analysis was used to explore the function of TOMM22 in nucleus pulposus cells. In addition, TOMM22 expression was compared between human normal and degenerated intervertebral disc tissue samples by immunohistochemistry and PCR.

Results

This study identified that the mitophagy pathway score was elevated in intervertebral disc degeneration compared with the normal condition. A strong link was present between mitophagy genes and immune cells, which may be used to typify intervertebral disc degeneration. The single-cell level showed that mitophagy-associated gene TOMM22 was highly expressed in medullary cells of the disease group. Further investigations indicated the upregulation of TOMM22 expression in late-stage nucleus pulposus cells and its role in cellular communication. In addition, human intervertebral disc tissue samples established that TOMM22 levels were higher in disc degeneration samples than in normal samples.

Conclusions

Our findings revealed that mitophagy may be used in the diagnosis of intervertebral disc degeneration and its typing, and TOMM22 is a molecule in this regard and may act as a potential diagnostic marker in intervertebral disc degeneration.

SIRT1-mediated deacetylation of FOXO3 enhances mitophagy and drives hormone resistance in endometrial cancer

BACKGROUND

The complex interplay between Sirtuin 1 (SIRT1) and FOXO3 in endometrial cancer (EC) remains understudied. This research aims to unravel the interactions of deacetylase SIRT1 and transcription factor FOXO3 in EC, focusing on their impact on mitophagy and hormone resistance.

METHODS

High-throughput sequencing, cell experiments, and bioinformatics tools were employed to investigate the roles and interactions of SIRT1 and FOXO3 in EC. Co-immunoprecipitation (Co-IP) assay was used to assess the interaction between SIRT1 and FOXO3 in RL95-2 cells. Functional assays were used to assess cell viability, proliferation, migration, invasion, apoptosis, and the expression of related genes and proteins. A mouse model of EC was established to evaluate tumor growth and hormone resistance under different interventions. Immunohistochemistry and TUNEL assays were used to assess protein expression and apoptosis in tumor tissues.

RESULTS

High-throughput transcriptome sequencing revealed a close association between SIRT1, FOXO3, and EC development. Co-IP showed a protein-protein interaction between SIRT1 and FOXO3. Overexpression of SIRT1 enhanced FOXO3 deacetylation and activity, promoting BNIP3 transcription and PINK1/Parkin-mediated mitophagy, which in turn promoted cell proliferation, migration, invasion, and inhibited apoptosis in vitro, as well as increased tumor growth and hormone resistance in vivo. These findings highlighted SIRT1 as an upstream regulator and potential therapeutic target in EC.

CONCLUSION

This study reveals a novel molecular mechanism underlying the functional relevance of SIRT1 in regulating mitophagy and hormone resistance through the deacetylation of FOXO3 in EC, thereby providing valuable insights for new therapeutic strategies.

Multi-omics and Single Cell Sequencing Analyses Reveal Associations of Mitophagy-Related Genes Predicting Clinical Prognosis and Immune Infiltration Characteristics in Osteosarcoma

Despite recent advances in clinical treatments, identifying high-risk osteosarcoma (OS) patients remains an unresolved clinical challenge. Mitophagy, a specialized form of cellular autophagy, selectively reduces the number of mitochondria or repairs their abnormal functions in response to external stress, thereby ensuring mitochondrial quality and maintaining mitochondrial function. Mitophagy plays a crucial role in cancer development, including processes such as mitochondrial repair, homeostasis maintenance, and tumor metabolism. However, its impact on OS has not yet been reported. In this study, we collected 58 mitophagy-related genes (MPRGs) from the TARGET and GEO databases and bioinformatically screened for those associated with OS prognosis. By LASSO-multivariable Cox regression algorithm, we subsequently developed a novel scoring system, the MPRG score, and validated its significance in predicting OS prognosis. Immune landscape analysis showed patients in the low MPRG group had a higher immune infiltration level than those in the high MPRG group. Drug sensitivity differences highlighted the potential need for alternative therapeutic strategies based on MPRG scoring system. The distribution characteristics of the MPRG signature in different cell subtypes of OS were explored by single-cell sequencing analyses. In vitro experiments further confirmed the abnormal expression of screened targets in OS. Our findings highlight the role of mitophagy in OS and its potential as a therapeutic target.

Lidamycin induces mitophagy in pancreatic cancer cells by regulating the expression of Mfn2

Lidamycin (LDM) has been confirmed to have a strong anti-pancreatic cancer effect and can affect the mitochondrial function of pancreatic cancer cells. Mitofusin-2 (Mfn2) is located in the outer membrane of mitochondria, and Mfn2 is currently believed to play a role in cancer inhibition in pancreatic cancer. In order to explore whether the anti-pancreatic cancer effect of LDM is related to Mfn2-mediated mitophagy, Bioinformatics and in vitro cell experiments are used for experimental research. The experimental results demonstrated that Mfn2 is correlated with mitochondrial autophagy in pancreatic cancer. Lidamycin can increase the expression of Mfn2 in pancreatic cancer and affect the process of EMT, affect the level of reactive oxygen species and mitochondrial membrane potential, and increase the expression of mitochondrial autophagy marker proteins BNIP3L and Beclin1. These results demonstrate that Mfn2 affects mitophagy in pancreatic cancer cells by regulating the expression of Mfn2.

Deapioplatycodin D promotes cell senescence induced by P21 through the mediation of incomplete mitophagy via BNIP3L

Deapioplatycodin D (DPD) is a triterpenoid saponin extracted from the root of Platycodon grandiflorum, which is a common source of medicine and food. Platycodon grandiflorum saponins have anti-inflammatory, antioxidative, antitumor, and immunity-promoting effects. However, the effect of DPD on hepatocellular carcinoma (HCC) cells has not been reported. The purpose of this study was to explore the cytotoxic effects and molecular mechanisms of DPD on HCC cells. Our study revealed that DPD significantly inhibits the proliferation of HCC, as demonstrated by the CCK-8 assay, and then we analyzed the inhibitory effects and pathways of DPD on HCC cells by Western blot and immunofluorescence assay, and found that DPD could increase the changes of autophagy-related protein levels, but had no significant effect on the expression of apoptosis-related proteins, and induced cell senescence. Then, transcriptomics analysis revealed that differential genes were significantly enriched in cell senescence and autophagy pathways and significant expression of mitochondrial autophagy-related gene BNIP3L and senescence-related gene P21. Subsequently, autophagy and cell senescence were analyzed using gene silencing, and it was found that DPD caused mitochondrial damage and promoted reactive oxygen species production, leading to the inhibition of autophagic fluxes and mitophagy via BNIP3L, and that DPD also mediated cell senescence via P21. Here, we found that autophagy promoted cell senescence, resulting in the inhibition of HCC cell proliferation. Similar results were obtained in the tumor-bearing model in vivo. In conclusion, DPD induces incomplete mitophagy and cell senescence in HCC cells, thereby inhibiting HCC cell proliferation. DPD is a potential new strategy for treating HCC.

Autophagy in aging-related diseases and cancer: Principles, regulatory mechanisms and therapeutic potential

Macroautophagy/autophagy is primarily accountable for the degradation of damaged organelles and toxic macromolecules in the cells. Regarding the essential function of autophagy for preserving cellular homeostasis, changes in, or dysfunction of, autophagy flux can lead to disease development. In the current paper, the complicated function of autophagy in aging-associated pathologies and cancer is evaluated, highlighting the underlying molecular mechanisms that can affect longevity and disease pathogenesis. As a natural biological process, a reduction in autophagy is observed with aging, resulting in an accumulation of cell damage and the development of different diseases, including neurological disorders, cardiovascular diseases, and cancer. The MTOR, AMPK, and ATG proteins demonstrate changes during aging, and they are promising therapeutic targets. Insulin/IGF1, TOR, PKA, AKT/PKB, caloric restriction and mitochondrial respiration are vital for lifespan regulation and can modulate or have an interaction with autophagy. The specific types of autophagy, such as mitophagy that degrades mitochondria, can regulate aging by affecting these organelles and eliminating those mitochondria with genomic mutations. Autophagy and its specific types contribute to the regulation of carcinogenesis and they are able to dually enhance or decrease cancer progression. Cancer hallmarks, including proliferation, metastasis, therapy resistance and immune reactions, are tightly regulated by autophagy, supporting the conclusion that autophagy is a promising target in cancer therapy.

The Interplay between Autophagy and Mitochondria in Cancer

Besides producing cellular energy, mitochondria are crucial in controlling oxidative stress and modulating cellular metabolism, particularly under stressful conditions. A key aspect of this regulatory role involves the recycling process of autophagy, which helps to sustain energy homeostasis. Autophagy, a lysosome-dependent degradation pathway, plays a fundamental role in maintaining cellular homeostasis by degrading damaged organelles and misfolded proteins. In the context of tumor formation, autophagy significantly influences cancer metabolism and chemotherapy resistance, contributing to both tumor suppression and surveillance. This review focuses on the relationship between mitochondria and autophagy, specifically in the context of cancer progression. Investigating the interaction between autophagy and mitochondria reveals new possibilities for cancer treatments and may result in the development of more effective therapies targeting mitochondria, which could have significant implications for cancer treatment. Additionally, this review highlights the increasing understanding of autophagy's role in tumor development, with a focus on modulating mitochondrial function and autophagy in both pre-clinical and clinical cancer research. It also explores the potential for developing more-targeted and personalized therapies by investigating autophagy-related biomarkers.

PFN1 Knockdown Aggravates Mitophagy to Retard Lung Adenocarcinoma Initiation and M2 Macrophage Polarization

Tumor-associated macrophages (TAM) are considered as crucial influencing factors of lung adenocarcinoma (LUAD) carcinogenesis and metastasis. Profilin 1 (PFN1) has been proposed as a potent driver of migration and drug resistance in LUAD. The focus of this work was to figure out the functional mechanism of PFN1 in macrophage polarization in LUAD. PFN1 expression and its significance in patients' survival were detected by ENCORI and Kaplan-Meier Plotter. RT-qPCR and western blotting examined PFN1 expression in LUAD cells. CCK-8 assay and colony formation assay detected cell proliferation. Flow cytometry detected cell apoptosis. Relevant assay kit tested caspase3 concentration. Western blotting analyzed the expression of proliferation- and apoptosis-related proteins. RT-qPCR and immunofluorescence staining measured M1 and M2 macrophages markers. Mitophagy was assessed by MitoTracker Red staining, immunofluorescence staining, and western blotting. PFN1 expression was increased in LUAD tissues and cells and correlated with the poor survival rate of LUAD patients. Deficiency of PFN1 hindered the proliferation, whereas facilitated the apoptosis of LUAD cells. Additionally, PFN1 interference impaired M2 macrophage polarization. Moreover, PFN1 knockdown exacerbated the mitophagy in LUAD cells and mitophagy inhibitor mitochondrial division inhibitor 1 (Mdivi-1) notably reversed the effects of PFN1 down-regulation on the proliferation, apoptosis as well as macrophage polarization in LUAD cells. To sum up, activation of mitophagy initiated by PFN1 depletion might obstruct the occurrence and M2 macrophage polarization in LUAD.

Mitophagy in fibrotic diseases: molecular mechanisms and therapeutic applications

Mitophagy is a highly precise process of selective autophagy, primarily aimed at eliminating excess or damaged mitochondria to maintain the stability of both mitochondrial and cellular homeostasis. In recent years, with in-depth research into the association between mitophagy and fibrotic diseases, it has been discovered that this process may interact with crucial cellular biological processes such as oxidative stress, inflammatory responses, cellular dynamics regulation, and energy metabolism, thereby influencing the occurrence and progression of fibrotic diseases. Consequently, modulating mitophagy holds promise as a therapeutic approach for fibrosis. Currently, various methods have been identified to regulate mitophagy to prevent fibrosis, categorized into three types: natural drug therapy, biological therapy, and physical therapy. This review comprehensively summarizes the current understanding of the mechanisms of mitophagy, delves into its biological roles in fibrotic diseases, and introduces mitophagy modulators effective in fibrosis, aiming to provide new targets and theoretical basis for the investigation of fibrosis-related mechanisms and disease prevention.

Mitophagy at the crossroads of cancer development: Exploring the role of mitophagy in tumor progression and therapy resistance

Preserving a functional mitochondrial network is crucial for cellular well-being, considering the pivotal role of mitochondria in ensuring cellular survival, especially under stressful conditions. Mitophagy, the selective removal of damaged mitochondria through autophagy, plays a pivotal role in preserving cellular homeostasis by preventing the production of harmful reactive oxygen species from dysfunctional mitochondria. While the involvement of mitophagy in neurodegenerative diseases has been thoroughly investigated, it is becoming increasingly evident that mitophagy plays a significant role in cancer biology. Perturbations in mitophagy pathways lead to suboptimal mitochondrial quality control, catalyzing various aspects of carcinogenesis, including establishing metabolic plasticity, stemness, metabolic reconfiguration of cancer-associated fibroblasts, and immunomodulation. While mitophagy performs a delicate balancing act at the intersection of cell survival and cell death, mounting evidence indicates that, particularly in the context of stress responses induced by cancer therapy, it predominantly promotes cell survival. Here, we showcase an overview of the current understanding of the role of mitophagy in cancer biology and its potential as a target for cancer therapy. Gaining a more comprehensive insight into the interaction between cancer therapy and mitophagy has the potential to reveal novel targets and pathways, paving the way for enhanced treatment strategies for therapy-resistant tumors in the near future.

Autophagy and metabolic aging: Current understanding and future applications

"Metabolic aging" refers to the gradual decline in cellular metabolic function across various tissues due to defective hormonal signaling, impaired nutrient sensing, mitochondrial dysfunction, replicative stress, and cellular senescence. While this process usually corresponds with chronological aging, the recent increase in metabolic diseases and cancers occurring at younger ages in humans suggests the premature onset of cellular fatigue and metabolic aging. Autophagy, a cellular housekeeping process facilitated by lysosomes, plays a crucial role in maintaining tissue rejuvenation and health. However, various environmental toxins, hormones, lifestyle changes, and nutrient imbalances can disrupt autophagy in humans. In this review, we explore the connection between autophagy and cellular metabolism, its regulation by extrinsic factors and its modulation to prevent the early onset of metabolic aging.

The Role of Endothelial Cell Mitophagy in Age-Related Cardiovascular Diseases

Aging is a major risk factor for cardiovascular diseases (CVD), and mitochondrial autophagy impairment is considered a significant physiological change associated with aging. Endothelial cells play a crucial role in maintaining vascular homeostasis and function, participating in various physiological processes such as regulating vascular tone, coagulation, angiogenesis, and inflammatory responses. As aging progresses, mitochondrial autophagy impairment in endothelial cells worsens, leading to the development of numerous cardiovascular diseases. Therefore, regulating mitochondrial autophagy in endothelial cells is vital for preventing and treating age-related cardiovascular diseases. However, there is currently a lack of systematic reviews in this area. To address this gap, we have written this review to provide new research and therapeutic strategies for managing aging and age-related cardiovascular diseases.

Targeting cellular mitophagy as a strategy for human cancers

Mitophagy is the cellular process to selectively eliminate dysfunctional mitochondria, governing the number and quality of mitochondria. Dysregulation of mitophagy may lead to the accumulation of damaged mitochondria, which plays an important role in the initiation and development of tumors. Mitophagy includes ubiquitin-dependent pathways mediated by PINK1/Parkin and non-ubiquitin dependent pathways mediated by mitochondrial autophagic receptors including NIX, BNIP3, and FUNDC1. Cellular mitophagy widely participates in multiple cellular process including metabolic reprogramming, anti-tumor immunity, ferroptosis, as well as the interaction between tumor cells and tumor-microenvironment. And cellular mitophagy also regulates tumor proliferation and metastasis, stemness, chemoresistance, resistance to targeted therapy and radiotherapy. In this review, we summarized the underlying molecular mechanisms of mitophagy and discussed the complex role of mitophagy in diverse contexts of tumors, indicating it as a promising target in the mitophagy-related anti-tumor therapy.

SIRT1-activating butein inhibits arecoline-induced mitochondrial dysfunction through PGC1α and MTP18 in oral cancer

BACKGROUND

Mitochondrial dysfunction associated with mitochondrial DNA mutations, enzyme defects, generation of ROS, and altered oxidative homeostasis is known to induce oral carcinogenesis during exposure to arecoline. Butein, a natural small molecule from Butea monosperma, possesses anti-inflammatory, anti-diabetic, and anti-cancer effects. However, the role of butein in the mitochondrial quality control mechanism has not been illuminated clearly.

PURPOSE

This study aimed to explore the role of butein in preserving mitochondrial quality control during arecoline-induced mitochondrial dysfunction in oral cancer to curtail the early onset of carcinogenesis.

METHODS

Cell viability was evaluated by MTT assay. The relative protein expressions were determined by western blotting. Immunofluorescence and confocal imaging were used to analyze the relative fluorescence and co-localization of proteins. Respective siRNAs were used to examine the knockdown-based studies.

RESULTS

Butein, in the presence of arecoline, significantly caused a decrease in mitochondrial hyperpolarization and ROS levels in oral cancer cells. Mechanistically, we found an increase in COXIV, TOM20, and PGC1α expression during butein treatment, and inhibition of PGC1α blunted mitochondrial biogenesis and decreased the mitochondrial pool. Moreover, the fission protein MTP18, and its molecular partners DRP1 and MFF were dose-dependently increased during butein treatment to maintain mitochondria mass. In addition, we also found increased expression of various mitophagy proteins, including PINK1, Parkin, and LC3 during butein treatment, suggesting the clearance of damaged mitochondria to maintain a healthy mitochondrial pool. Interestingly, butein increased the activity of SIRT1 to enhance the functional mitochondrial pool, and inhibition of SIRT1 found to reduce the mitochondrial levels, as evident from the decrease in the expression of PGC1α and MTP18 in oral cancer cells.

CONCLUSION

Our study proved that SIRT1 maintains a functional mitochondrial pool through PGC1α and MTP18 for biogenesis and fission of mitochondria during arecoline exposure and could decrease the risk of mitochondria dysfunctionality associated with the onset of oral carcinogenesis.

Decoding mitochondria's role in immunity and cancer therapy

The functions of mitochondria, including energy production and biomolecule synthesis, have been known for a long time. Given the rising incidence of cancer, the role of mitochondria in cancer has become increasingly popular. Activated by components released by mitochondria, various pathways interact with each other to induce immune responses to protect organisms from attack. However, mitochondria play dual roles in the progression of cancer. Abnormalities in proteins, which are the elementary structures of mitochondria, are closely linked with oncogenesis. Both the aberrant accumulation of intermediates and mutations in enzymes result in the generation and progression of cancer. Therefore, targeting mitochondria to treat cancer may be a new strategy. Several drugs aimed at inhibiting mutated enzymes and accumulated intermediates have been tested clinically. Here, we discuss the current understanding of mitochondria in cancer and the interactions between mitochondrial functions, immune responses, and oncogenesis. Furthermore, we discuss mitochondria as hopeful targets for cancer therapy, providing insights into the progression of future therapeutic strategies.

Targeted ferritinophagy in gastrointestinal cancer: from molecular mechanisms to implications

Gastrointestinal cancer is a significant global health burden, necessitating the development of novel therapeutic strategies. Emerging evidence has highlighted the potential of targeting ferritinophagy as a promising approach for the treatment of gastrointestinal cancer. Ferritinophagy is a form of selective autophagy that is mediated by the nuclear receptor coactivator 4 (NCOA4). This process plays a crucial role in regulating cellular iron homeostasis and has been implicated in various pathological conditions, including cancer. This review discusses the molecular mechanisms underlying ferritinophagy and its relevance to gastrointestinal cancer. Furthermore, we highlight the potential therapeutic implications of targeting ferritinophagy in gastrointestinal cancer. Several approaches have been proposed to modulate ferritinophagy, including small molecule inhibitors and immunotherapeutic strategies. We discuss the advantages and challenges associated with these therapeutic interventions and provide insights into their potential clinical applications.

Navigating the tumor microenvironment: mesenchymal stem cell-mediated delivery of anticancer agents

Scientific knowledge of cancer has advanced greatly throughout the years, with most recent studies findings includes many hallmarks that capture disease's multifaceted character. One of the novel approach utilised for the delivery of anti-cancer agents includes mesenchymal stem cell mediated drug delivery. Mesenchymal stem cells (MSCs) are non-haematopoietic progenitor cells that may be extracted from bone marrow, tooth pulp, adipose tissue and placenta/umbilical cord blood dealing with adult stem cells. MSCs are mostly involved in regeneration of tissue, they have also been shown to preferentially migrate to location of several types of tumour in-vivo. Usage of MSCs ought to improve both effectiveness and safety of anti-cancer drugs by enhancing delivery efficiency of anti-cancer therapies to tumour site. Numerous researches has demonstrated that various drugs, when delivered via mesenchymal stem cell mediated delivery can elicit anti-tumour effect of cells in cancers of breast cells and thyroid cells. MSCs have minimal immunogenicity because to lack of co-stimulatory molecule expression, which means there is no requirement for immunosuppression after allogenic transplantation. This current review elaborates recent advancements of mesenchyma stem cell mediated drug delivery of anti-cancer agents along with its mechanism and previously reported studies of drugs manufactured via this drug delivery system.

ADT-OH exhibits anti-metastatic activity on triple-negative breast cancer by combinatorial targeting of autophagy and mitochondrial fission

High basal autophagy and enhanced mitochondrial fission in triple-negative breast cancer (TNBC) cells support cell migration and promote plasticity of cancer cell metabolism. Here, we suggest a novel combination therapy approach for the treatment of TNBC that targets Drp1-mediated mitochondrial fission and autophagy pathways. Hydrogen sulfide (H2S) mediates a myriad of biological processes, including autophagy and mitochondrial function. In this study, we demonstrated that 5-(4-hydroxyphenyl)-3H-1,2-dithiole-3-thione (ADT-OH), one of the most widely utilized sustained-release H2S donors, effectively suppresses metastasis of TNBC cells in the absence of proliferation inhibition in vitro and in vivo. ADT-OH treatment ameliorated autophagy flux by suppressing autophagosome formation and induced mitochondrial elongation through decreasing expression of dynamin-related protein 1 (Drp1) and increasing expression of mitochondrial fusion protein (Mfn2). At the same time, ADT-OH downregulated mitophagy flux and inhibited mitochondrial function, eventually leading to the inhibition of migration and invasion in TNBC cells. In vivo, intraperitoneal administration of ADT-OH revealed a potent anti-metastatic activity in three different animal models, the MDA-MB-231 orthotopic xenograft model, the 4T1-Luci orthotopic model and the 4T1-Luci tail vein metastasis model. However, ADT-OH has an extremely low water solubility, which is a significant barrier to its effectiveness. Thus, we demonstrated that the solubility of ADT-OH in water can be improved significantly by absorption with hydroxypropyl-β-cyclodextrin (CD). Remarkably, the obtained CD-ADT-OH demonstrated superior anti-cancer effect to ADT-OH in vivo. Altogether, this study describes a novel regulator of mammalian mitochondrial fission and autophagy, with potential utility as an experimental therapeutic agent for metastatic TNBC.

TRIM21-mediated ubiquitylation of TAT suppresses liver metastasis in gallbladder cancer

Liver metastasis is common in patients with gallbladder cancer (GBC), imposing a significant challenge in clinical management and serving as a poor prognostic indicator. However, the mechanisms underlying liver metastasis remain largely unknown. Here, we report a crucial role of tyrosine aminotransferase (TAT) in liver metastasis of GBC. TAT is frequently up-regulated in GBC tissues. Increased TAT expression is associated with frequent liver metastasis and poor prognosis of GBC patients. Overexpression of TAT promotes GBC cell migration and invasion in vitro, as well as liver metastasis in vivo. TAT knockdown has the opposite effects. Intriguingly, TAT promotes liver metastasis of GBC by potentiating cardiolipin-dependent mitophagy. Mechanistically, TAT directly binds to cardiolipin and leads to cardiolipin externalization and subsequent mitophagy. Moreover, TRIM21 (Tripartite Motif Containing 21), an E3 ubiquitin ligase, interacts with TAT. The histine residues 336 and 338 at TRIM21 are essential for this binding. TRIM21 preferentially adds the lysine 63 (K63)-linked ubiquitin chains on TAT principally at K136. TRIM21-mediated TAT ubiquitination impairs its dimerization and mitochondrial location, subsequently inhibiting tumor invasion and migration of GBC cells. Therefore, our study identifies TAT as a novel driver of GBC liver metastasis, emphasizing its potential as a therapeutic target.

From macroautophagy to mitophagy: Unveiling the hidden role of mitophagy in gastrointestinal disorders

In this editorial, we comment on an article titled “Morphological and biochemical characteristics associated with autophagy in gastrointestinal diseases”, which was published in a recent issue of the World Journal of Gastroenterology. We focused on the statement that “autophagy is closely related to the digestion, secretion, and regeneration of gastrointestinal cells”. With advancing research, autophagy, and particularly the pivotal role of the macroautophagy in maintaining cellular equilibrium and stress response in the gastrointestinal system, has garnered extensive study. However, the significance of mitophagy, a unique selective autophagy pathway with ubiquitin-dependent and independent variants, should not be overlooked. In recent decades, mitophagy has been shown to be closely related to the occurrence and development of gastrointestinal diseases, especially inflammatory bowel disease, gastric cancer, and colorectal cancer. The interplay between mitophagy and mitochondrial quality control is crucial for elucidating disease mechanisms, as well as for the development of novel treatment strategies. Exploring the pathogenesis behind gastrointestinal diseases and providing individualized and efficient treatment for patients are subjects we have been exploring. This article reviews the potential mechanism of mitophagy in gastrointestinal diseases with the hope of providing new ideas for diagnosis and treatment.