Mitophagy in tumorigenesis and metastasis

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.

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.

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.

Opportunistic pathogen Porphyromonas gingivalis targets the LC3B-ceramide complex and mediates lethal mitophagy resistance in oral tumors

Mechanisms by which Porphyromonas gingivalis (P. gingivalis) infection enhances oral tumor growth or resistance to cell death remain elusive. Here, we determined that P. gingivalis infection mediates therapeutic resistance via inhibiting lethal mitophagy in cancer cells and tumors. Mechanistically, P. gingivalis targets the LC3B-ceramide complex by associating with LC3B via bacterial major fimbriae (FimA) protein, preventing ceramide-dependent mitophagy in response to various therapeutic agents. Moreover, ceramide-mediated mitophagy is induced by Annexin A2 (ANXA2)-ceramide association involving the E142 residue of ANXA2. Inhibition of ANXA2-ceramide-LC3B complex formation by wild-type P. gingivalis prevented ceramide-dependent mitophagy. Moreover, a FimA-deletion mutant P. gingivalis variant had no inhibitory effects on ceramide-dependent mitophagy. Further, 16S rRNA sequencing of oral tumors indicated that P. gingivalis infection altered the microbiome of the tumor macroenvironment in response to ceramide analog treatment in mice. Thus, these data provide a mechanism describing the pro-survival roles of P. gingivalis in oral tumors.

Multi omics analysis of mitophagy subtypes and integration of machine learning for predicting immunotherapy responses in head and neck squamous cell carcinoma

Mitophagy serves as a critical mechanism for tumor cell death, significantly impacting the progression of tumors and their treatment approaches. There are significant challenges in treating patients with head and neck squamous cell carcinoma, underscoring the importance of identifying new targets for therapy. The function of mitophagy in head and neck squamous carcinoma remains uncertain, thus investigating its impact on patient outcomes and immunotherapeutic responses is especially crucial. We initially analyzed the differential expression, prognostic value, intergene correlations, copy number variations, and mutation frequencies of mitophagy-related genes at the pan-cancer level. Through unsupervised clustering, we divided head and neck squamous carcinoma into three subtypes with distinct prognoses, identified the signaling pathway features of each subtype using ssGSEA, and characterized subtype B as having features of an immune desert using various immune infiltration calculation methods. Using multi-omics data, we identified the genomic variation characteristics, mutated gene pathway features, and drug sensitivity features of the mitophagy subtypes. Utilizing a combination of 10 machine learning algorithms, we have developed a prognostic scoring model called Mitophagy Subgroup Risk Score (MSRS), which is used to predict patient survival and the response to immune checkpoint blockade therapy. Simultaneously, we applied MSRS to single-cell analysis to explore intercellular communication. Through laboratory experiments, we validated the biological function of SLC26A9, one of the genes in the risk model. In summary, we have explored the significant role of mitophagy in head and neck tumors through multi-omics data, providing new directions for clinical treatment.

Recent Advances in Molecular and Genetic Research on Uveal Melanoma

Uveal melanoma (UM), a distinct subtype of melanoma, presents unique challenges in its clinical management due to its complex molecular landscape and tendency for liver metastasis. This review highlights recent advancements in understanding the molecular pathogenesis, genetic alterations, and immune microenvironment of UM, with a focus on pivotal genes, such as GNAQ/11, BAP1, and CYSLTR2, and delves into the distinctive genetic and chromosomal classifications of UM, emphasizing the role of mutations and chromosomal rearrangements in disease progression and metastatic risk. Novel diagnostic biomarkers, including circulating tumor cells, DNA and extracellular vesicles, are discussed, offering potential non-invasive approaches for early detection and monitoring. It also explores emerging prognostic markers and their implications for patient stratification and personalized treatment strategies. Therapeutic approaches, including histone deacetylase inhibitors, MAPK pathway inhibitors, and emerging trends and concepts like CAR T-cell therapy, are evaluated for their efficacy in UM treatment. This review identifies challenges in UM research, such as the limited treatment options for metastatic UM and the need for improved prognostic tools, and suggests future directions, including the discovery of novel therapeutic targets, immunotherapeutic strategies, and advanced drug delivery systems. The review concludes by emphasizing the importance of continued research and innovation in addressing the unique challenges of UM to improve patient outcomes and develop more effective treatment strategies.

Migrasome, a migration-dependent organelle

Migrasomes are organelles produced by migrating cells that form on retraction fibers and are released during cell migration. Migrasomes are involved in physiological and pathological processes such as intercellular communication, cell homeostasis maintenance, signal transduction, disease occurrence and development, and cancer metastasis. In addition, methods and techniques for studying migrasomes are constantly evolving. Here, we review the discovery, formation process, regulation, and known functions of migrasomes, summarize the commonly used specific markers of migrasomes, and the methods for observing migrasomes. Meanwhile, this review also discusses the potential applications of migrasomes in physiological processes, disease diagnosis, treatment, and prognosis, and looks forward to their wider application in biomedicine. In addition, the study of migrasomes will also reveal a new perspective on the mechanism of intercellular communication and promote the further development of life science.

A Phyto-mycotherapeutic Supplement, Namely Ganostile, as Effective Adjuvant in Brain Cancer Management: An In Vitro Study Using U251 Human Glioblastoma Cell Line

The current standard oncotherapy for glioblastoma is limited by several adverse side effects, leading to a short-term patient survival rate paralleled by a worsening quality of life (QoL). Recently, Complementary and Integrative Medicine's (CIM) innovative approaches have shown positive impacts in terms of better response to treatment, side effect reduction, and QoL improvement. In particular, promising potential in cancer therapy has been found in compounds coming from phyto- and mycotherapy. The objective of this study was to demonstrate the beneficial effects of a new phyto-mycotherapy supplement, named Ganostile, in the human glioblastoma cell line U251, in combination with chemotherapeutic agents, i.e., Cisplatin and a new platinum-based prodrug. Choosing a supplement dosage that mimicked oral supplementation in humans (about 1 g/day), through in vitro assays, microscopy, and cytometric analysis, it has emerged that the cells, after 48hr continuous exposure to Ganostile in combination with the chemical compounds, showed a higher mortality and a lower proliferation rate than the samples subjected to the different treatments administered individually. In conclusion, our data support the use of Ganostile in integrative oncology protocols as a promising adjuvant able to amplify conventional and new drug effects and also reducing resistance mechanisms often observed in brain tumors.

Mitophagy and cancer: role of BNIP3/BNIP3L as energetic drivers of stemness features, ATP production, proliferation, and cell migration

Mitophagy is a selective form of autophagy which permits the removal of dysfunctional or excess mitochondria. This occurs as an adaptative response to physiological stressors, such as hypoxia, nutrient deprivation, or DNA damage. Mitophagy is promoted by specific mitochondrial outer membrane receptors, among which are BNIP3 and BNIP3L. The role of mitophagy in cancer is being widely studied, and more specifically in the maintenance of cancer stem cell (CSC) properties, such as self-renewal. Given that CSCs are responsible for treatment failure and metastatic capacity, targeting mitophagy could be an interesting approach for CSC elimination. Herein, we describe a new model system to enrich sub-populations of cancer cells with high basal levels of mitophagy, based on the functional transcriptional activity of BNIP3 and BNIP3L. Briefly, we employed a BNIP3(L)-promoter-eGFP-reporter system to isolate cancer cells with high BNIP3/BNIP3L transcriptional activity by flow cytometry (FACS). The model was validated by using complementary lysosomal and mitophagy-specific probes, as well as the mitochondrially-targeted red fluorescent protein (RFP), namely mt-Keima. High BNIP3/BNIP3L transcriptional activity was accompanied by increases in i) BNIP3/BNIP3L protein levels, ii) lysosomal mass, and iii) basal mitophagy activity. Furthermore, cancer cells with increased BNIP3/BNIP3L transcriptional activity exhibited CSC features, such as greater mammosphere-forming ability and high CD44 levels. To further explore the model, we also analysed other stemness characteristics in MCF7 and MDA-MB-231 breast cancer cell lines, directly demonstrating that BNIP3(L)-high cells were more metabolically active, proliferative, migratory, and drug-resistant, with elevated anti-oxidant capacity. Therefore, high levels of basal mitophagy appear to enhance CSC features.

mtROS-mediated mitophagy is involved in aflatoxin-B1 induced liver injury in ducks

Aflatoxin B1 (AFB1) is highly toxic to the liver and can cause excessive production of mitochondrial reactive oxygen species (mtROS) in hepatocytes, leading to oxidative stress, inflammation, fibrosis, cirrhosis, and even liver cancer. The overproduction of mtROS can induce mitophagy, but whether mtROS and mitophagy are involved in the liver injury induced by AFB1 in ducks remains unclear. In this study, we first demonstrated that overproduction of mtROS and mitophagy occurred during liver injury induced by AFB1 exposure in ducks. Then, by inhibiting mtROS and mitophagy, we found that the damage caused by AFB1 in ducks was significantly alleviated, and the overproduction of mtROS induced by AFB1 exposure could mediate the occurrence of mitophagy. These results suggested that mtROS-mediated mitophagy is involved in AFB1-induced duck liver injury, and they may be the prevention and treatment targets of AFB1 hepatotoxicity.

P53/NANOG balance; the leading switch between poorly to well differentiated status in liver cancer cells

Enforcing a well-differentiated state on cells requires tumor suppressor p53 activation as a key player in apoptosis induction and well differentiation. In addition, recent investigations showed a significant correlation between poorly differentiated status and higher expression of NANOG. Inducing the expression of NANOG and decreasing p53 level switch the status of liver cancer cells from well differentiated to poorly status. In this review, we highlighted p53 and NANOG cross-talk in hepatocellular carcinoma (HCC) which is regulated through mitophagy and makes it a novel molecular target to attenuate cancerous phenotype in the management of this tumor.

Toosendanin Induces Lung Squamous Cell Carcinoma Cell Apoptosis and Inhibits Tumor Progression via the BNIP3/AMPK Signaling Pathway

Lung squamous cell carcinoma (LUSC) is the second most common type of non-small cell lung cancer. Toosendanin can target critical cancer cell survival and proliferation. However, the function of toosendanin in LUSC is limited. Cancer cell proliferative capacity is detected using cell morphology, colony formation, and flow cytometry. The invasiveness of the cells is detected by a Transwell assay, western blotting, and RT-qPCR. Nude mice are injected with H226 (1×106) and received an intraperitoneal injection of toosendanin every 2 days for 21 days. RNA sequence transcriptome analysis is performed on toosendanin-treated cells to identify target genes and signaling pathways. With increasing concentrations of toosendanin, the rate of cell proliferation decreases and apoptotic cells increases. The number of migrated cells significantly reduces and epithelial-mesenchymal transition is reversed. Injection of toosendanin in nude mice leads to a reduction in tumor volume, weight, and the number of metastatic tumors. Furthermore, KEGG shows that genes related to the AMPK pathway are highly enriched. BNIP3 is the most differentially expressed gene, and its expression along with phosphorylated-AMPK significantly increases in toosendanin-treated cells. Toosendanin exerts anticancer effects, induces apoptosis in LUSC cells, and inhibits tumor progression via the BNIP3/AMPK signaling pathway.

Prohibitions in the meta-inflammatory response: a review

Prohibitins are the central regulatory element of cellular homeostasis, especially by modulating the response at different levels: Nucleus, mitochondria and membranes. Their localization and interaction with various proteins, homons, transcription and nuclear factors, and mtDNA indicate the globality and complexity of their pleiotropic properties, which remain to be investigated. A more detailed deciphering of cellular metabolism in relation to prohibitins under normal conditions and in various metabolic diseases will allow us to understand the precise role of prohibitins in the signaling cascades of PI3K/Akt, Raf/MAP/ERK, STAT3, p53, and others and to fathom their mutual influence. A valuable research perspective is to investigate the role of prohibitins in the molecular and cellular interactions between the two major players in the pathogenesis of obesity-adipocytes and macrophages - that form the basis of the meta-inflammatory response. Investigating the subtle intercellular communication and molecular cascades triggered in these cells will allow us to propose new therapeutic strategies to eliminate persistent inflammation, taking into account novel molecular genetic approaches to activate/inactivate prohibitins.

Hypoxic adaptation of mitochondria and its impact on tumor cell function

Mitochondria are the major sink for oxygen in the cell, consuming it during ATP production. Therefore, when environmental oxygen levels drop in the tumor, significant adaptation is required. Mitochondrial activity is also a major producer of biosynthetic precursors and a regulator of cellular oxidative and reductive balance. Because of the complex biochemistry, mitochondrial adaptation to hypoxia occurs through multiple mechanisms and has significant impact on other cellular processes such as macromolecule synthesis and gene regulation. In tumor hypoxia, mitochondria shift their location in the cell and accelerate the fission and quality control pathways. Hypoxic mitochondria also undergo significant changes to fundamental metabolic pathways of carbon metabolism and electron transport. These metabolic changes further impact the nuclear epigenome because mitochondrial metabolites are used as enzymatic substrates for modifying chromatin. This coordinated response delivers physiological flexibility and increased tumor cell robustness during the environmental stress of low oxygen.

USP26 promotes colorectal cancer tumorigenesis by restraining PRKN-mediated mitophagy

Deubiquitinating enzymes (DUBs) are promising targets for cancer therapy because of their pivotal roles in various physiological and pathological processes. Among these, ubiquitin-specific peptidase 26 (USP26) is a protease with crucial regulatory functions. Our study sheds light on the upregulation of USP26 in colorectal cancer (CRC), in which its increased expression correlates with an unfavorable prognosis. Herein, we evidenced the role of USP26 in promoting CRC tumorigenesis in a parkin RBR E3 ubiquitin-protein ligase (PRKN) protein-dependent manner. Our investigation revealed that USP26 directly interacted with PRKN protein, facilitating its deubiquitination, and subsequently reducing its activity. Additionally, we identified the K129 site on PRKN as a specific target for USP26-mediated deubiquitination. Our research highlights that a K-to-R mutation at the site on PRKN diminishes its potential for activation and ability to mediate mitophagy. In summary, our findings underscore the significance of USP26-mediated deubiquitination in restraining the activation of the PRKN-mediated mitophagy pathway, ultimately driving CRC tumorigenesis. This study not only elucidated the multifaceted role of USP26 in CRC but also introduced a promising avenue for therapeutic exploration through the development of small molecule inhibitors targeting USP26. This strategy holds promise as a novel therapeutic approach for CRC.

Targeting PARP14 with lomitapide suppresses drug resistance through the activation of DRP1-induced mitophagy in multiple myeloma

Multiple myeloma (MM) is a hematological malignancy that remains incurable, primarily due to the high likelihood of relapse or development of resistance to current treatments. To explore and discover new medications capable of overcoming drug resistance in MM, we conducted cell viability inhibition screens of 1504 FDA-approved drugs. Lomitapide, a cholesterol-lowering agent, was found to exhibit effective inhibition on bortezomib-resistant MM cells in vitro and in vivo. Our data also indicated that lomitapide decreases the permeability of the mitochondrial outer membrane and induces mitochondrial dysfunction in MM cells. Next, lomitapide treatment upregulated DRP1 and PINK1 expression levels, coupled with the mitochondrial translocation of Parkin, leading to MM cell mitophagy. Excessive mitophagy caused mitochondrial damage and dysfunction induced by lomitapide. Meanwhile, PARP14 was identified as a direct target of lomitapide by SPR-HPLC-MS, and we showed that DRP1-induced mitophagy was crucial in the anti-MM activity mediated by PARP14. Furthermore, PARP14 is overexpressed in MM patients, implying that it is a novel therapeutic target in MM. Collectively, our results demonstrate that DRP1-mediated mitophagy induced by PARP14 may be the cause for mitochondrial dysfunction and damage in response to lomitapide treatment.

Biodegradable Zn-5Dy Alloy with Enhanced Osteo/Angio-Genic Activity and Osteointegration Effect via Regulation of SIRT4-Dependent Mitochondrial Function

Zinc (Zn)-dysprosium (Dy) binary alloys are promising biodegradable bone fracture fixation implants owing to their attractive biodegradability and mechanical properties. However, their clinical application is a challenge for bone fracture healing, due to the lack of Zn-Dy alloys with tailored proper bio-mechanical and osteointegration properties for bone regeneration. A Zn-5Dy alloy with high strength and ductility and a degradation rate aligned with the bone remodeling cycle is developed. Here, mechanical stability is further confirmed, proving that Zn-5Dy alloy can resist aging in the degradation process, thus meeting the mechanical requirements of fracture fixation. In vitro cellular experiments reveal that the Zn-5Dy alloy enhances osteogenesis and angiogenesis by elevating SIRT4-mediated mitochondrial function. In vivo Micro-CT, SEM-EDS, and immunohistochemistry analyses further indicate good biosafety, suitable biodegradation rate, and great osteointegration of Zn-5Dy alloy during bone healing, which also depends on the upregulation of SIRT4-mediated mitochondrial events. Overall, the study is the first to report a Zn-5Dy alloy that exerts remarkable osteointegration properties and has a strong potential to promote bone healing. Furthermore, the results highlight the importance of mitochondrial modulation and shall guide the future development of mitochondria-targeting materials in enhancing bone fracture healing.

The role of BCL2L13 in glioblastoma: turning a need into a target

Glioblastoma (GBM) is the most common aggressive central nervous system cancer. GBM has a high mortality rate, with a median survival time of 12-15 months after diagnosis. A poor prognosis and a shorter life expectancy may result from resistance to standard treatments such as radiation and chemotherapy. Temozolomide has been the mainstay treatment for GBM, but unfortunately, there are high rates of resistance with GBM bypassing apoptosis. A proposed mechanism for bypassing apoptosis is decreased ceramide levels, and previous research has shown that within GBM cells, B cell lymphoma 2-like 13 (BCL2L13) can inhibit ceramide synthase. This review aims to discuss the causes of resistance in GBM cells, followed by a brief description of BCL2L13 and an explanation of its mechanism of action. Further, lipids, specifically ceramide, will be discussed concerning cancer and GBM cells, focusing on ceramide synthase and its role in developing GBM. By gathering all current information on BCL2L13 and ceramide synthase, this review seeks to enable an understanding of these pieces of GBM in the hope of finding an effective treatment for this disease.

Trifluoperazine activates AMPK / mTOR / ULK1 signaling pathway to induce mitophagy in osteosarcoma cells

Osteosarcoma is a prevalent kind of primary bone malignancy. Trifluoperazine, as an antipsychotic drug, has anti-tumor activity against a variety of cancers. Nevertheless, the impact of trifluoperazine on osteosarcoma is unclear. Our investigation aimed to explore the mechanism of trifluoperazine's effect on osteosarcoma. We found that trifluoperazine inhibited 143B and U2-OS osteosarcoma cell proliferation in a method based on the dose. Furthermore, it was shown that trifluoperazine induced the accumulation of reactive oxygen species (ROS) to cause mitochondrial damage and induced mitophagy in osteosarcoma cells. Finally, combined with RNA-seq results, we first demonstrated the AMPK/mTOR/ULK1 signaling pathway as a potential mechanism of trifluoperazine-mediated mitophagy in osteosarcoma cells and can be suppressed by AMPK inhibitor Compound C.

A novel NIR fluorescent probe inhibits melanoma progression through apoptosis and ERK/DRP1-mediated mitochondrial fission

Melanoma, a highly metastatic malignant tumour, necessitated early detection and intervention. This study focuses on a hemicyanine fluorescent probe activated by near-infrared (NIR) light for bioimaging and targeted mitochondrial action in melanoma cells. IR-418, our newly designed hemicyanine-based NIR fluorescent probe, demonstrated effective targeting of melanoma cell mitochondria for NIR imaging. In vitro and in vivo experiments revealed IR-418's inhibition of melanoma growth through the promotion of mitochondrial apoptosis (Bax/Bcl-2/Cleaved Caspase pathway). Moreover, IR-418 inhibited melanoma metastasis by inhibiting mitochondrial fission through the ERK/DRP1 pathway. Notably, IR-418 mitigated abnormal ATL and ASL elevations caused by tumours without inflicting significant organ damage, indicating its high biocompatibility. In conclusion, IR-418, a novel hemicyanine-based NIR fluorescent probe targeting the mitochondria, exhibits significant fluorescence imaging capability, anti-melanoma proliferation, anti-melanoma lung metastasis activities and high biosafety. Therefore, it has significant potential in the early diagnosis and treatment of melanoma.

Decoding the Versatile Landscape of Autophagic Protein VMP1 in Cancer: A Comprehensive Review across Tissue Types and Regulatory Mechanisms

Autophagy, a catabolic process orchestrating the degradation of proteins and organelles within lysosomes, is pivotal for maintaining cellular homeostasis. However, its dual role in cancer involves preventing malignant transformation while fostering progression and therapy resistance. Vacuole Membrane Protein 1 (VMP1) is an essential autophagic protein whose expression, per se, triggers autophagy, being present in the whole autophagic flux. In pancreatic cancer, VMP1-whose expression is linked to the Kirsten Rat Sarcoma Virus (KRAS) oncogene-significantly contributes to disease promotion, progression, and chemotherapy resistance. This investigation extends to breast cancer, colon cancer, hepatocellular carcinoma, and more, highlighting VMP1's nuanced nature, contingent on specific tissue contexts. The examination of VMP1's interactions with micro-ribonucleic acids (miRNAs), including miR-21, miR-210, and miR-124, enhances our understanding of its regulatory network in cancer. Additionally, this article discusses VMP1 gene fusions, especially with ribosomal protein S6 kinase B1 (RPS6KB1), shedding light on potential implications for tumor malignancy. By deciphering the molecular mechanisms linking VMP1 to cancer progression, this exploration paves the way for innovative therapeutic strategies to disrupt these pathways and potentially improve treatment outcomes.

Drp1: Focus on Diseases Triggered by the Mitochondrial Pathway

Drp1 (Dynamin-Related Protein 1) is a cytoplasmic GTPase protein encoded by the DNM1L gene that influences mitochondrial dynamics by mediating mitochondrial fission processes. Drp1 has been demonstrated to play an important role in a variety of life activities such as cell survival, proliferation, migration, and death. Drp1 has been shown to play different physiological roles under different physiological conditions, such as normal and inflammation. Recently studies have revealed that Drp1 plays a critical role in the occurrence, development, and aggravation of a series of diseases, thereby it serves as a potential therapeutic target for them. In this paper, we review the structure and biological properties of Drp1, summarize the biological processes that occur in the inflammatory response to Drp1, discuss its role in various cancers triggered by the mitochondrial pathway and investigate effective methods for targeting Drp1 in cancer treatment. We also synthesized the phenomena of Drp1 involving in the triggering of other diseases. The results discussed herein contribute to our deeper understanding of mitochondrial kinetic pathway-induced diseases and their therapeutic applications. It is critical for advancing the understanding of the mechanisms of Drp1-induced mitochondrial diseases and preventive therapies.

Identification of HSPD1 as a novel invasive biomarker associated with mitophagy in pituitary adenomas

BACKGROUND

The crucial role of mitophagy in tumor progression has been recognized. Therefore, our study aimed to investigate the potential correlation between pituitary adenoma invasiveness and the mitophagy processes.

METHODS

In this study, we used transcriptomics of postoperative tissue from 32 patients and quantitative proteomics of 19 patients to screen for mitophagy-related invasion genes in pituitary adenomas. The invasive predictive value of target genes was analyzed by Lasso regression model, CytoHubba plugin and expression validation. Co-expression correlation analysis was used to identify paired proteins for target genes, and a predictive model for pituitary adenoma invasiveness was constructed by target genes and paired proteins and assessed using ROC analysis, calibration curves and DCA. GO function, pathway (GSEA or GSVA) and immune cell analysis (ssGSEA or CIBERSORT) were further utilized to explore the action mechanism of target gene. Finally, immunohistochemistry and cell function experiments were used to detect the differential expression and key roles of the target genes in pituitary adenomas.

RESULTS

Finally, Heat shock protein family D member 1 (HSPD1) was identified as a target gene. The quality of a predictive model for pituitary adenoma invasiveness consisting of HSPD1 and its paired protein expression profiles was satisfactory. Moreover, the expression of HSPD1 was significantly lower in invasive pituitary adenomas than in non-invasive pituitary adenomas. Downregulation of HSPD1 may be significantly related to invasion process, mitochondria-related pathway and immune cell regulation in pituitary adenomas.

CONCLUSION

The downregulation of HSPD1 may serve as a predictive indicator for identifying invasive pituitary adenomas.

Comprehensive analysis of mitochondria-related genes indicates that PPP2R2B is a novel biomarker and promotes the progression of bladder cancer via Wnt signaling pathway

Bladder cancer (BC) is the fourth and tenth most common malignancy in men and women worldwide, respectively. The complexity of the molecular biological mechanism behind BC is a major contributor to the lack of effective treatment management of the disease. The development and genesis of BC are influenced by mitochondrial retrograde control and mitochondria-nuclear cross-talk. However, the role of mitochondrial-related genes in BC remains unclear. In this study, we analyzed TCGA datasets and identified 752 DE-MRGs in BC samples, including 313 down-regulated MRGs and 439 up-regulated MRGs. Then, the results of machine-learning screened four critical diagnostic genes, including GLRX2, NMT1, PPP2R2B and TRAF3IP3. Moreover, we analyzed their prognostic value and confirmed that only PPP2R2B was associated with clinical prognosis of BC patients and Cox regression assays validated that PPP2R2B expression was a distinct predictor of overall survival in BC patients. Them, we performed RT-PCR and found that PPP2R2B expression was distinctly decreased in BC specimens and cell lines. Functional experiments revealed that overexpression of PPP2R2B distinctly suppressed the proliferation, migration and invasion of BC cells via Wnt signaling pathway. In summary, these research findings offer potential molecular markers for the diagnosis and prognosis of BC, with the discovery of PPP2R2B particularly holding significant biological and clinical significance. This study provides valuable clues for future in-depth investigations into the molecular mechanisms of BC, as well as the development of new diagnostic markers and therapeutic targets.

An integral role of mitochondrial function in the pathophysiology of preeclampsia

Preeclampsia (PE) is associated with high maternal and perinatal morbidity and mortality. The development of effective treatment strategies remains a major challenge due to the limited understanding of the pathogenesis. In this review, we summarize the current understanding of PE research, focusing on the molecular basis of mitochondrial function in normal and PE placentas, and discuss perspectives on future research directions. Mitochondria integrate numerous physiological processes such as energy production, cellular redox homeostasis, mitochondrial dynamics, and mitophagy, a selective autophagic clearance of damaged or dysfunctional mitochondria. Normal placental mitochondria have evolved innovative survival strategies to cope with uncertain environments (e.g., hypoxia and nutrient starvation). Cytotrophoblasts, extravillous trophoblast cells, and syncytiotrophoblasts all have distinct mitochondrial morphology and function. Recent advances in molecular studies on the spatial and temporal changes in normal mitochondrial function are providing valuable insight into PE pathogenesis. In PE placentas, hypoxia-mediated mitochondrial fission may induce activation of mitophagy machinery, leading to increased mitochondrial fragmentation and placental tissue damage over time. Repair mechanisms in mitochondrial function restore placental function, but disruption of compensatory mechanisms can induce apoptotic death of trophoblast cells. Additionally, molecular markers associated with repair or compensatory mechanisms that may influence the development and progression of PE are beginning to be identified. However, contradictory results have been obtained regarding some of the molecules that control mitochondrial biogenesis, dynamics, and mitophagy in PE placentas. In conclusion, understanding how the mitochondrial morphology and function influence cell fate decisions of trophoblast cells is an important issue in normal as well as pathological placentation biology. Research focusing on mitochondrial function will become increasingly important for elucidating the pathogenesis and effective treatment strategies of PE.

Constructing and Evaluating a Mitophagy-Related Gene Prognostic Model: Implications for Immune Landscape and Tumor Biology in Lung Adenocarcinoma

Mitophagy, a conserved cellular mechanism, is crucial for cellular homeostasis through the selective clearance of impaired mitochondria. Its emerging role in cancer development has sparked interest, particularly in lung adenocarcinoma (LUAD). Our study aimed to construct a risk model based on mitophagy-related genes (MRGs) to predict survival outcomes, immune response, and chemotherapy sensitivity in LUAD patients. We mined the GeneCards database to identify MRGs and applied LASSO/Cox regression to formulate a prognostic model. Validation was performed using two independent Gene Expression Omnibus (GEO) cohorts. Patients were divided into high- and low-risk categories according to the median risk score. The high-risk group demonstrated significantly reduced survival. Multivariate Cox analysis confirmed the risk score as an independent predictor of prognosis, and a corresponding nomogram was developed to facilitate clinical assessments. Intriguingly, the risk score correlated with immune infiltration levels, oncogenic expression profiles, and sensitivity to anticancer agents. Enrichment analyses linked the risk score with key oncological pathways and biological processes. Within the model, MTERF3 emerged as a critical regulator of lung cancer progression. Functional studies indicated that the MTERF3 knockdown suppressed the lung cancer cell proliferation and migration, enhanced mitophagy, and increased the mitochondrial superoxide production. Our novel prognostic model, grounded in MRGs, promises to refine therapeutic strategies and prognostication in lung cancer management.

Microvascular rarefaction caused by the NOTCH signaling pathway is a key cause of TKI-apatinib-induced hypertension and cardiac damage

With the advancement of tumour-targeted therapy technology, the survival of cancer patients has continued to increase, and cardiovascular events have gradually become an important cause of death in cancer patients. This phenomenon occurs due to adverse cardiovascular reactions caused by the cardiovascular toxicity of antitumour therapy. Moreover, the increase in the proportion of elderly patients with cancer and cardiovascular diseases is due to the extension of life expectancy. Hypertension is the most common cardiovascular side effect of small molecule tyrosine kinase inhibitors (TKIs). The increase in blood pressure induced by TKIs and subsequent cardiovascular complications and events affect the survival and quality of life of patients and partly offset the benefits of antitumour therapy. Many studies have confirmed that in the pathogenesis of hypertension, arterioles and capillary thinness are involved in its occurrence and development. Our previous findings showing that apatinib causes microcirculation rarefaction of the superior mesenteric artery and impaired microvascular growth may inspire new therapeutic strategies for treating hypertension. Thus, by restoring microvascular development and branching patterns, total peripheral resistance and blood pressure are reduced. Therefore, exploring the key molecular targets of TKIs that inhibit the expression of angiogenic factors and elucidating the specific molecular mechanism involved are key scientific avenues for effectively promoting endothelial cell angiogenesis and achieving accurate repair of microcirculation injury in hypertension patients.

The critical roles of STING in mitochondrial homeostasis

The stimulator of interferon genes (STING) is a crucial signaling hub in the immune system's antiviral and antimicrobial defense by detecting exogenous and endogenous DNA. The multifaceted functions of STING have been uncovered gradually during past decades, including homeostasis maintenance and overfull immunity or inflammation induction. However, the subcellular regulation of STING and mitochondria is poorly understood. The main functions of STING are outlined in this review. Moreover, we discuss how mitochondria and STING interact through multiple mechanisms, including the release of mitochondrial DNA (mtDNA), modulation of mitochondria-associated membrane (MAM) and mitochondrial dynamics, alterations in mitochondrial metabolism, regulation of reactive oxygen species (ROS) production, and mitochondria-related cell death. Finally, we discuss how STING is crucial to disease development, providing a novel perspective on its role in cellular physiology and pathology.

Selective autophagy in cancer: mechanisms, therapeutic implications, and future perspectives

Eukaryotic cells engage in autophagy, an internal process of self-degradation through lysosomes. Autophagy can be classified as selective or non-selective depending on the way it chooses to degrade substrates. During the process of selective autophagy, damaged and/or redundant organelles like mitochondria, peroxisomes, ribosomes, endoplasmic reticulum (ER), lysosomes, nuclei, proteasomes, and lipid droplets are selectively recycled. Specific cargo is delivered to autophagosomes by specific receptors, isolated and engulfed. Selective autophagy dysfunction is closely linked with cancers, neurodegenerative diseases, metabolic disorders, heart failure, etc. Through reviewing latest research, this review summarized molecular markers and important signaling pathways for selective autophagy, and its significant role in cancers. Moreover, we conducted a comprehensive analysis of small-molecule compounds targeting selective autophagy for their potential application in anti-tumor therapy, elucidating the underlying mechanisms involved. This review aims to supply important scientific references and development directions for the biological mechanisms and drug discovery of anti-tumor targeting selective autophagy in the future.

DMSA-coated IONPs trigger oxidative stress, mitochondrial metabolic reprograming and changes in mitochondrial disposition, hindering cell cycle progression of cancer cells

There is increasing interest in modulating the redox homeostasis of tumors since high levels of reactive oxygen species (ROS) make them more vulnerable to changes in these species. Nanomedicine offers promise in this context as such applications may provoke biological responses that induce ROS production. Indeed, iron oxide nanoparticles (IONPs) can induce ROS accumulation through the so-called Fenton reaction of iron, further augmenting the ROS in tumors and overloading the antioxidant system beyond its capacity, thereby driving oxidative stress to a level that is incompatible with cell survival. Here, three different coatings for IONPs were compared to assess their intrinsic capacity to induce ROS production in cells. Of these coatings, dimercaptosuccinic acid-coated IONPs (DMSA-NPs) provoked the strongest ROS production, which was associated with the ability to reprogram the metabolism of cancer cells. This latter phenomenon involved shutting-down oxidative phosphorylation (OXPHOS), shifting mitochondrial morphology towards a more elongated phenotype, reducing the total mitochondrial mass and ultimately, blocking cell proliferation by inducing G0/G1 cell cycle arrest. Consequently, the data obtained highlights the importance of studying the chemical properties of IONPs, presenting DMSA-NPs as a novel tool to induce oxidative stress in cancer cells and alter their cell fate.

In vitro anticancer effect of azithromycin targeting hypoxic lung cancer cells via the inhibition of mitophagy

Solid tumors are predisposed to hypoxia, which induces tumor progression, and causes resistance to treatment. Hypoxic tumor cells exploit auto- and mitophagy to facilitate metabolism and mitochondrial renewal. Azithromycin (AZM), a widely used macrolide, inhibits autophagy in cancer cells. The aim of the present study was to determine whether AZM targeted hypoxic cancer cells by inhibiting mitophagy. Lung cancer cell lines (A549, H1299 and NCI-H441) were cultured for up to 72 h under normoxic (20% O2) or hypoxic (0.3% O2) conditions in the presence or absence of AZM (≤25 µM), and the cell survival, autophagy flux and mitophagy flux were evaluated. AZM treatment reduced cell survival under hypoxic conditions, caused mitolysosome dysfunction with raised lysosomal pH and impaired the efficient removal of hypoxia-damaged mitochondria, eventually inducing apoptosis in the cancer cells. The cytotoxic effect of AZM under hypoxic conditions was abolished in mitochondria-deficient A549 cells (ρ° cells). The present study demonstrated that AZM reduced lung cancer cell survival under hypoxic conditions by interfering with the efficient removal of damaged mitochondria through mitophagy inhibition. Thus, AZM may be considered as a promising anticancer drug that targets the mitochondrial vulnerability of hypoxic lung cancer cells.

Involvement of mitochondrial dynamics and mitophagy in diabetic endothelial dysfunction and cardiac microvascular injury

Endothelial cells (ECs), found in the innermost layer of blood vessels, are crucial for maintaining the structure and function of coronary microcirculation. Dysregulated coronary microcirculation poses a fundamental challenge in diabetes-related myocardial microvascular injury, impacting myocardial blood perfusion, thrombogenesis, and inflammation. Extensive research aims to understand the mechanistic connection and functional relationship between cardiac EC dysfunction and the development, diagnosis, and treatment of diabetes-related myocardial microvascular injury. Despite the low mitochondrial content in ECs, mitochondria act as sensors of environmental and cellular stress, influencing EC viability, structure, and function. Mitochondrial dynamics and mitophagy play a vital role in orchestrating mitochondrial responses to various stressors by regulating morphology, localization, and degradation. Impaired mitochondrial dynamics or reduced mitophagy is associated with EC dysfunction, serving as a potential molecular basis and promising therapeutic target for diabetes-related myocardial microvascular injury. This review introduces newly recognized mechanisms of damaged coronary microvasculature in diabetes-related microvascular injury and provides updated insights into the molecular aspects of mitochondrial dynamics and mitophagy. Additionally, novel targeted therapeutic approaches against diabetes-related microvascular injury or endothelial dysfunction, focusing on mitochondrial fission and mitophagy in endothelial cells, are summarized.

The role of mitochondrial dynamics in disease

Mitochondria are multifaceted and dynamic organelles regulating various important cellular processes from signal transduction to determining cell fate. As dynamic properties of mitochondria, fusion and fission accompanied with mitophagy, undergo constant changes in number and morphology to sustain mitochondrial homeostasis in response to cell context changes. Thus, the dysregulation of mitochondrial dynamics and mitophagy is unsurprisingly related with various diseases, but the unclear underlying mechanism hinders their clinical application. In this review, we summarize the recent developments in the molecular mechanism of mitochondrial dynamics and mitophagy, particularly the different roles of key components in mitochondrial dynamics in different context. We also summarize the roles of mitochondrial dynamics and target treatment in diseases related to the cardiovascular system, nervous system, respiratory system, and tumor cell metabolism demanding high-energy. In these diseases, it is common that excessive mitochondrial fission is dominant and accompanied by impaired fusion and mitophagy. But there have been many conflicting findings about them recently, which are specifically highlighted in this view. We look forward that these findings will help broaden our understanding of the roles of the mitochondrial dynamics in diseases and will be beneficial to the discovery of novel selective therapeutic targets.

The Prognosis of Cancer Depends on the Interplay of Autophagy, Apoptosis, and Anoikis within the Tumor Microenvironment

Within the tumor microenvironment, the fight between the immune system and cancer influences tumor transformation. Metastasis formation is an important stage in the progression of cancer. This process is aided by cellular detachment and resistance to anoikis, which are achieved by altering intercellular signaling. Autophagy, specifically pro-survival autophagy, aids cancer cells in developing treatment resistance. Numerous studies have shown that autophagy promotes tumor growth and resistance to anoikis. To regulate protective autophagy, cancer-related genes phosphorylate both pro- and anti-apoptotic proteins. Apoptosis, a type of controlled cell death, eliminates damaged or unwanted cells. Anoikis is a type of programmed cell death in which cells lose contact with the extracellular matrix. The dysregulation of these cellular pathways promotes tumor growth and spread. Apoptosis, anoikis, and autophagy interact meticulously and differently depending on the cellular circumstances. For instance, autophagy can protect cancer cells from apoptosis by removing cellular components that are damaged and might otherwise trigger apoptotic pathways. Similarly, anoikis dysregulation can trigger autophagy by causing cellular harm and metabolic stress. In order to prevent or treat metastatic disease, specifically, targeting these cellular mechanisms may present a promising prospect for cancer therapy. This review discourses the state of our understanding of the molecular and cellular mechanisms underlying tumor transformation and the establishment of metastatic tumors. To enhance the prognosis for cancer, we highlight and discuss potential therapeutic approaches that target these processes and genes involved in them.

Promotion of NAD+ recycling by the hypoxia-induced shift in the lactate dehydrogenase isozyme profile reduces the senescence of human bone marrow-derived endothelial progenitor cells

Expansion of bone marrow-derived endothelial progenitor cells (EPCs) in vitro to obtain required cell numbers for therapeutic applications faces the challenge of growing cell senescence under the traditional normoxic culture condition. We previously found that 1% O2 hypoxic culture condition is favorable for reducing senescence of EPCs, but the mechanisms underlying the favorability are still unclear. Here, we found that, compared with normoxia, hypoxia induced a shift in lactate dehydrogenase (LDH) isozyme profile, which manifested as decreased LDH2 and LDH1 and increased LDH5, LDH4 and total LDHs. Moreover, under hypoxia, EPCs presented higher LDH activity, which could promote the conversion of pyruvate to lactate, as well as a higher level of NAD+, Bcl2 interacting protein 3 (BNIP3) expression and mitophagy. Additionally, under hypoxia, knock-down of the LDHA subunit increased the LDH2 and LDH1 levels and knock-down of the LDHB subunit increased the LDH5 level, while the simultaneous knock-down of LDHA and LDHB reduced total LDHs and NAD+ level. Inhibition of NAD+ recycling reduced BNIP3 expression and mitophagy and promoted cell senescence. Taken together, these data demonstrated that 1% O2 hypoxia induces a shift in the LDH isozyme profile, promotes NAD+ recycling, increases BNIP3 expression and mitophagy, and reduces EPC senescence. Our findings contribute to a better understanding of the connection between hypoxic culture conditions and the senescence of bone marrow-derived EPCs and provide a novel strategy to improve in vitro expansion of EPCs.

Deciphering the implications of mitophagy-related signatures in clinical outcomes and microenvironment heterogeneity of clear cell renal cell carcinoma

BACKGROUND

The role of mitophagy in various cancer-associated biological processes is well recognized. Nonetheless, the comprehensive implications of mitophagy in clear cell renal cell carcinoma (ccRCC) necessitate further exploration.

METHODS

Based on the transcriptomic data encompassing 25 mitophagy-related genes (MRGs), we identified the distinct mitophage patterns in 763 ccRCC samples. Subsequently, a mitophage-related predictive signature with machine learning algorithms was constructed, designated as RiskScore, to quantify the individual mitophagy status in ccRCC patients. Employing multispectral immunofluorescence (mIF) and immunohistochemistry (IHC) staining, we detected the effect of PTEN-induced putative kinase 1 (PINK1) in the prognosis and immune microenvironment of ccRCC.

RESULTS

Our analysis initially encompassed a comprehensive assessment of the expression profiling, genomic variations, and interactions among the 25 MRGs in ccRCC. Subsequently, the consensus clustering algorithm was applied to stratify ccRCC patients into three clusters with distinct prognostic outcomes, tumor microenvironment (TME) characteristics, and underlying biological pathways. We screened eight pivotal genes (CLIC4, PTPRB, SLC16A12, ENPP5, FLRT3, HRH2, PDK4, and SCD5) to construct a mitophagy-related predictive signature, which showed excellent prognostic value for ccRCC patients. Moreover, patient subgroups divided by the RiskScore showed contrasting expression levels of immune checkpoints (ICPs), abundance of immune cells, and immunotherapy response. Additionally, a nomogram was established with robust predictive power integrating the RiskScore and clinical features. Notably, we observed that PINK1 expression markedly correlated with favorable treatment response and advanced maturation stages of tertiary lymphoid structures, which potentially shed light on enhancing anti-tumor immunity of ccRCC.

CONCLUSION

Collectively, this study initially developed a signature associated with mitophagy, which demonstrated an excellent ability to predict the clinical prognosis, TME characterization, and responsiveness to targeted therapy and immunotherapy for ccRCC patients. Of particular note is the pivotal role of PINK1 in mediating the treatment response and immune microenvironment for ccRCC patients.

RNA methylation reading protein YTHDF2 relieves myocardial ischemia-reperfusion injury by downregulating BNIP3 via m6A modification

BNIP3 is reported to be involved in hypoxia-induced mitochondrial defect and cell death in cardiomyocytes. However, little is known about the specific function and molecular mechanism of BNIP3-mediated mitophagy in myocardial ischemia-reperfusion injury (MIRI). Herein, this study explored the mechanism regulating BNIP3-modulated mitophagy in MIRI. Rat cardiomyocytes (H9c2 cells) underwent transfection and hypoxia/reoxygenation (H/R) treatment, followed by cell viability and apoptosis detection. Gain-of-function assays were conducted in rats before MIRI modeling, followed by the monitoring of cardiac changes and the evaluation of cardiac function, myocardial infarction area, and apoptosis in myocardial tissues. The levels of creatine kinase MB (CK-MB), cardiac troponin I (cTnI), lactic dehydrogenase (LDH), reactive oxygen species (ROS), malondialdehyde (MDA), superoxide dismutase (SOD), p62, and LC3 II/LC3 I were tested in rat serum or H9c2 cells. The co-localization of LC3 and TOMM20 was analyzed. The interaction of BNIP3 with YTHDF2 was assessed. H/R treatment decreased cell viability and p62 and SOD levels while elevating cell apoptosis, the levels of CK-MB, cTnI, LDH, MDA, ROS, and LC3 II/LC3 I, the number of autophagosomes, and the co-localization of LC3 and TOMM20 in cardiomyocytes, which were neutralized by downregulating BNIP3 or upregulating YTHDF2. Moreover, upregulation of YTHDF2 repressed myocardial injury and mitophagy in MIRI rats. Mechanistically, YTHDF2 mediated BNIP3 expression by recognizing methylated BNIP3. Upregulation of BNIP3 counteracted the suppressive effect of YTHDF2 overexpression on H/R-induced injury and mitophagy in cardiomyocytes. The RNA methylation reading protein YTHDF2 ameliorated MIRI by downregulating BNIP3 via m6A modification.

Mitophagy-promoting agents and their ability to promote healthy-aging

The removal of damaged mitochondrial components through a process called mitochondrial autophagy (mitophagy) is essential for the proper function of the mitochondrial network. Hence, mitophagy is vital for the health of all aerobic animals, including humans. Unfortunately, mitophagy declines with age. Many age-associated diseases, including Alzheimer's and Parkinson's, are characterized by the accumulation of damaged mitochondria and oxidative damage. Therefore, activating the mitophagy process with small molecules is an emerging strategy for treating multiple aging diseases. Recent studies have identified natural and synthetic compounds that promote mitophagy and lifespan. This article aims to summarize the existing knowledge about these substances. For readers' convenience, the knowledge is presented in a table that indicates the chemical data of each substance and its effect on lifespan. The impact on healthspan and the molecular mechanism is reported if known. The article explores the potential of utilizing a combination of mitophagy-inducing drugs within a therapeutic framework and addresses the associated challenges of this strategy. Finally, we discuss the process that balances mitophagy, i.e. mitochondrial biogenesis. In this process, new mitochondrial components are generated to replace the ones cleared by mitophagy. Furthermore, some mitophagy-inducing substances activate biogenesis (e.g. resveratrol and metformin). Finally, we discuss the possibility of combining mitophagy and biogenesis enhancers for future treatment. In conclusion, this article provides an up-to-date source of information about natural and synthetic substances that activate mitophagy and, hopefully, stimulates new hypotheses and studies that promote healthy human aging worldwide.

LncRNA UCA1 promotes pancreatic cancer cell migration by regulating mitochondrial dynamics via the MAPK pathway

PURPOSE

Long non-coding RNA urothelial cancer associated 1 (UCA1) serves as an oncogene in various cancers. However, the mechanism underlying the role of UCA1 in pancreatic cancer remains unclear. This study aimed to explore the role of UCA1 in pancreatic cancer.

METHODS

The expression and prognosis of UCA1 were analyzed using The Cancer Genome Atlas (TCGA) and Genotype-Tissue Expression (GTEx) databases. The results were validated by immunohistochemistry (IHC) and qRT-PCR. The biofunctions of UCA1 were analyzed using Gene Ontology (GO), Kyoto Encyclopedia of Genes and Genomes (KEGG), and Gene Set Enrichment Analysis (GSEA). The migration abilities and mitochondrial dynamics of PC cells were examined using the Transwell assay, mitochondrial membrane potential (MMP), and fluorescence. The mitochondrial-related protein and MAPK/ERK pathway markers were evaluated using western blotting.

RESULTS

UCA1 expression was significantly higher in pancreatic cancer tissues than in normal tissues. High UCA1 expression indicated poor clinical outcomes and was associated with clinical features in patients with pancreatic cancer. Additionally, high UCA1 expression is a potential independent marker for poor prognosis. Subsequently, we demonstrated that UCA1 enhanced the migration capability, increased MMP, enhanced mitochondrial fusion, and inhibited mitochondrial autophagy in pancreatic cancer cells via the MAPK/ERK pathway.

CONCLUSION

UCA1 promotes the migration by regulating the mitochondrial dynamics of pancreatic cancer cells via the MAPK/ERK pathway. Our findings suggest that UCA1 may serve as a potential biomarker in pancreatic cancer prognosis.

Ancient complexes of iron and sulfur modulate oncogenes and oncometabolism

Inorganic complexes of iron and sulfur, that is, iron-sulfur [FeS] clusters, have played a fundamental role in life on Earth since the prebiotic period. These clusters were involved in elementary reactions leading to the emergence of life and, since then, gained function in processes, such as respiration, replication, transcription, and the immune response. We discuss how three [FeS] proteins involved in the innate immune response play a role in oncogene expression/function and oncometabolism. Our analysis highlights the importance of future research into understanding the [FeS] clusters' roles in cancer progression and proliferation. The outcomes of these studies will help identify new targets and develop new anticancer therapeutics.

The Pro-Oncogenic Protein IF1 Promotes Proliferation of Anoxic Cancer Cells during Re-Oxygenation

Cancer cells overexpress IF1, the endogenous protein that inhibits the hydrolytic activity of ATP synthase when mitochondrial membrane potential (ΔμH+) falls, as in ischemia. Other roles have been ascribed to IF1, but the associated molecular mechanisms are still under debate. We investigated the ability of IF1 to promote survival and proliferation in osteosarcoma and colon carcinoma cells exposed to conditions mimicking ischemia and reperfusion, as occurs in vivo, particularly in solid tumors. IF1-silenced and parental cells were exposed to the FCCP uncoupler to collapse ΔμH+ and the bioenergetics of cell models were validated. All the uncoupled cells preserved mitochondrial mass, but the implemented mechanisms differed in IF1-expressing and IF1-silenced cells. Indeed, the membrane potential collapse and the energy charge preservation allowed an increase in both mitophagy and mitochondrial biogenesis in IF1-expressing cells only. Interestingly, the presence of IF1 also conferred a proliferative advantage to cells highly dependent on oxidative phosphorylation when the uncoupler was washed out, mimicking cell re-oxygenation. Overall, our results indicate that IF1, by allowing energy preservation and promoting mitochondrial renewal, can favor proliferation of anoxic cells and tumor growth. Therefore, hindering the action of IF1 may be promising for the therapy of tumors that rely on oxidative phosphorylation for energy production.

Prognostic signature based on mitochondria quality control proteins for the prediction of lung adenocarcinoma patients survival

Lung cancer is the leading cause of cancer mortality worldwide. In recent years, the incidence of lung cancer subtype lung adenocarcinoma (LUAD) has steadily increased. Mitochondria, as a pivotal site of cell bioenergetics, metabolism, cell signaling, and cell death, are often dysregulated in lung cancer cells. Mitochondria maintenance and integrity depend on mitochondrial quality control proteins (MQCPs). During lung cancer progression, the levels of MQCPs could change and promote cancer cell adaptation to the microenvironment and stresses. Here, univariate and multivariate proportional Cox regression analyses were applied to develop a signature based on the level of MQCPs (dimeric form of BNIP3, DRP1, and SIRT3) in tumorous and non-tumorous samples of 80 patients with LUAD. The MQCP signature could be used to separate the patients with LUAD into high- and low-risk groups. Survival analysis indicated that patients in the high-risk group had dramatically shorter overall survival compared with the low-risk patients. Moreover, a nomogram combining clinicopathologic features and the MQCP signature was constructed and validated to predict 1-, 3-, and 5-year overall survival of the patients. Thus, this study presents a novel signature based on MQCPs as a reliable prognostic tool to predict overall survival for patients with LUAD.

Biological effects and mechanisms of fisetin in cancer: a promising anti-cancer agent

Fisetin, a natural flavonoid, possesses numerous biological activities that have been extensively studied in various diseases. When it comes to cancer, fisetin exhibits a range of biological effects, such as suppressing cell growth, triggering programmed cell death, reducing the formation of new blood vessels, protecting against oxidative stress, and inhibiting cell migration. Moreover, fisetin has the ability to enhance the effectiveness of chemotherapy. The anticancer properties of fisetin can be attributed to a diverse array of molecules and signaling pathways, including vascular endothelial growth factor (VEGF), mitogen-activated protein kinase (MAPK), nuclear factor-kappa B (NF-κB), PI3K/Akt/mTOR, and Nrf2/HO-1. Consequently, fisetin holds promise as a therapeutic agent for anticancer treatment. In this review, we place emphasis on the biological functions and various molecular targets of fisetin in anticancer therapy.

SIRT5 Activation and Inorganic Phosphate Binding Reduce Cancer Cell Vitality by Modulating Autophagy/Mitophagy and ROS

Cancer cells show increased glutamine consumption. The glutaminase (GLS) enzyme controls a limiting step in glutamine catabolism. Breast tumors, especially the triple-negative subtype, have a high expression of GLS. Our recent study demonstrated that GLS activity and ammonia production are inhibited by sirtuin 5 (SIRT5). We developed MC3138, a selective SIRT5 activator. Treatment with MC3138 mimicked the deacetylation effect mediated by SIRT5 overexpression. Moreover, GLS activity was regulated by inorganic phosphate (Pi). Considering the interconnected roles of GLS, SIRT5 and Pi in cancer growth, our hypothesis is that activation of SIRT5 and reduction in Pi could represent a valid antitumoral strategy. Treating cells with MC3138 and lanthanum acetate, a Pi chelator, decreased cell viability and clonogenicity. We also observed a modulation of MAP1LC3B and ULK1 with MC3138 and lanthanum acetate. Interestingly, inhibition of the mitophagy marker BNIP3 was observed only in the presence of MC3138. Autophagy and mitophagy modulation were accompanied by an increase in cytosolic and mitochondrial reactive oxygen species (ROS). In conclusion, our results show how SIRT5 activation and/or Pi binding can represent a valid strategy to inhibit cell proliferation by reducing glutamine metabolism and mitophagy, leading to a deleterious accumulation of ROS.

CLU (clusterin) promotes mitophagic degradation of MSX2 through an AKT-DNM1L/Drp1 axis to maintain SOX2-mediated stemness in oral cancer stem cells

Mitophagy regulates cancer stem cell (CSC) populations affecting tumorigenicity and malignancy in various cancer types. Here, we report that cisplatin treatment led to the activation of higher mitophagy through regulating CLU (clusterin) levels in oral CSCs. Moreover, both the gain-of-function and loss-of-function of CLU indicated its mitophagy-specific role in clearing damaged mitochondria. CLU also regulates mitochondrial fission by activating the Ser/Thr kinase AKT, which triggered phosphorylation of DNM1L/Drp1 at the serine 616 residue initiating mitochondrial fission. More importantly, we also demonstrated that CLU-mediated mitophagy positively regulates oral CSCs through mitophagic degradation of MSX2 (msh homeobox 2), preventing its nuclear translocation from suppressing SOX2 activity and subsequent inhibition of cancer stemness and self-renewal ability. However, CLU knockdown disturbed mitochondrial metabolism generating excessive mitochondrial superoxide, which improves the sensitivity to cisplatin in oral CSCs. Notably, our results showed that CLU-mediated cytoprotection relies on SOX2 expression. SOX2 inhibition through genetic (shSOX2) and pharmacological (KRX-0401) strategies reverses CLU-mediated cytoprotection, sensitizing oral CSCs toward cisplatin-mediated cell death.

Autophagy and autophagy-related pathways in cancer

Maintenance of protein homeostasis and organelle integrity and function is critical for cellular homeostasis and cell viability. Autophagy is the principal mechanism that mediates the delivery of various cellular cargoes to lysosomes for degradation and recycling. A myriad of studies demonstrate important protective roles for autophagy against disease. However, in cancer, seemingly opposing roles of autophagy are observed in the prevention of early tumour development versus the maintenance and metabolic adaptation of established and metastasizing tumours. Recent studies have addressed not only the tumour cell intrinsic functions of autophagy, but also the roles of autophagy in the tumour microenvironment and associated immune cells. In addition, various autophagy-related pathways have been described, which are distinct from classical autophagy, that utilize parts of the autophagic machinery and can potentially contribute to malignant disease. Growing evidence on how autophagy and related processes affect cancer development and progression has helped guide efforts to design anticancer treatments based on inhibition or promotion of autophagy. In this Review, we discuss and dissect these different functions of autophagy and autophagy-related processes during tumour development, maintenance and progression. We outline recent findings regarding the role of these processes in both the tumour cells and the tumour microenvironment and describe advances in therapy aimed at autophagy processes in cancer.

Oxymatrine suppresses colorectal cancer progression by inhibiting NLRP3 inflammasome activation through mitophagy induction in vitro and in vivo

Chinese herb Radix sophorae tonkinensis extract oxymatrine shows anticancer effects. This study evaluated the role of oxymatrine in colorectal cancer (CRC) and the underlying molecular events in vitro and in vivo. CRC cells were treated with different doses of oxymatrine to assess cell viability, reactive oxygen species production, gene expression, and gene alterations. Meanwhile, mouse xenograft and liver metastasis models were used to assess the effects of oxymatrine using histology examination, transmission electron microscopy, and Western blot, respectively. Our results showed that oxymatrine treatment triggered CRC cell mitophagy to inhibit CRC cell growth, migration, invasion, and metastasis in vitro and in vivo. At the gene level, oxymatrine inhibited LRPPRC to promote Parkin translocation into the mitochondria and reduce the mitophagy-activated NLRP3 inflammasome. Thus, oxymatrine had an anticancer activity through LRPPRC inhibition, mitophagy induction, and NLRP3 inflammasome suppression in the CRC cell xenograft and liver metastasis models. In conclusion, the study demonstrates the oxymatrine anti- CRC activity through its unique role in regulating CRC cell mitophagy and NLRP3 inflammasome levels in vitro and in vivo.

Kaempferol induces mitochondrial dysfunction and mitophagy by activating the LKB1/AMPK/MFF pathway in breast precancerous lesions

Kaempferol has been suggested to be an effective anticancer agent in several malignant tumors. However, its function and mechanisms in breast precancerous lesions remain largely elusive. Here, we showed that kaempferol induced excessive mitochondrial fission and mitochondrial damage with activated mitochondrial fission factor (MFF)-mediated dynamin-related protein (DRP) 1 mitochondrial translocation. As a result, the PTEN-induced putative kinase 1 (PINK1)/Parkin signaling pathway was activated, accompanied by excessive mitophagy and reduced mitochondrial mass in cells. We also revealed that kaempferol-induced lethal mitophagy contributed to inhibiting breast precancerous lesion growth in vitro and in vivo. Furthermore, we verified serine/threonine kinase 11 (STK11/LKB1)/AMP-activated protein kinase (AMPK) pathway deficiency in breast precancerous lesions. Moreover, LKB1/AMPK pathway reactivation by kaempferol was required for excessive mitochondrial fission and lethal mitophagy. Taken together, our findings shed new light on the molecular mechanisms related to breast cancer prevention by kaempferol and provide evidence for its potential clinical application.

Cancer Bioenergetics and Tumor Microenvironments-Enhancing Chemotherapeutics and Targeting Resistant Niches through Nanosystems

Cancer is an impending bottleneck in the advanced scientific workflow to achieve diagnostic, prognostic, and therapeutic success. Most cancers are refractory to conventional diagnostic and chemotherapeutics due to their limited targetability, specificity, solubility, and side effects. The inherent ability of each cancer to evolve through various genetic and epigenetic transformations and metabolic reprogramming underlies therapeutic limitations. Though tumor microenvironments (TMEs) are quite well understood in some cancers, each microenvironment differs from the other in internal perturbations and metabolic skew thereby impeding the development of appropriate diagnostics, drugs, vaccines, and therapies. Cancer associated bioenergetics modulations regulate TME, angiogenesis, immune evasion, generation of resistant niches and tumor progression, and a thorough understanding is crucial to the development of metabolic therapies. However, this remains a missing element in cancer theranostics, necessitating the development of modalities that can be adapted for targetability, diagnostics and therapeutics. In this challenging scenario, nanomaterials are modular platforms for understanding TME and achieving successful theranostics. Several nanoscale particles have been successfully researched in animal models, quite a few have reached clinical trials, and some have achieved clinical success. Nanoparticles exhibit an intrinsic capability to interact with diverse biomolecules and modulate their functions. Furthermore, nanoparticles can be functionalized with receptors, modulators, and drugs to facilitate specific targeting with reduced toxicity. This review discusses the current understanding of different theranostic nanosystems, their synthesis, functionalization, and targetability for therapeutic modulation of bioenergetics, and metabolic reprogramming of the cancer microenvironment. We highlight the potential of nanosystems for enhanced chemotherapeutic success emphasizing the questions that remain unanswered.