Nrf2: A critical participant in regulation of apoptosis, ferroptosis, and autophagy in gastric cancer

Nuclear factor erythroid 2-related factor-2 (Nrf2) is a specific transcription factor that maintains redox homeostasis by regulating the expression of anti-oxidative stress-related genes. Hyperactivation of Nrf2 is involved in tumor progression and is associated with chemoresistance in a large number of solid tumors. Programmatic cell death (PCD), such as apoptosis, ferroptosis, and autophagy, plays a crucial role in tumor development and chemotherapy sensitivity. Accumulating evidence suggests that some anti-tumor compounds and genes can induce massive production of reactive oxygen species (ROS) via inhibiting Nrf2 expression, which exacerbates oxidative stress and promotes Gastric cancer (GC) cell death, thereby enhancing the sensitivity of GC cells to chemotherapy-induced PCD. In this review, we summarize the role of antitumor drugs in interfering in three different types of PCD (apoptosis, ferroptosis, and autophagy) in GC cells by modulating Nrf2 expression, as well as the molecular mechanisms through which targeting Nrf2 brings about PCD and chemosensitivity. It is reasonable to believe that Nrf2 serves as a potential therapeutic target, and targeting Nrf2 by drug or gene regulation could provide a new strategy for the treatment of GC.

Targeting sub-cellular organelles for boosting precision photodynamic therapy

Among various cancer treatment methods, photodynamic therapy has received significant attention due to its non-invasiveness and high efficiency in inhibiting tumour growth. Recently, specific organelle targeting photosensitizers have received increasing interest due to their precise accumulation and ability to trigger organelle-mediated cell death signalling pathways, which greatly reduces the drug dosage, minimizes toxicity, avoids multidrug resistance, and prevents recurrence. In this review, recent advances and representative photosensitizers used in targeted photodynamic therapy on organelles, specifically including the endoplasmic reticulum, Golgi apparatus, mitochondria, nucleus, and lysosomes, have been comprehensively reviewed with a focus on organelle structure and organelle-mediated cell death signalling pathways. Furthermore, a perspective on future research and potential challenges in precision photodynamic therapy has been presented at the end.

Valence-Transforming O2-Depleting Nano-Assembly Enable In Situ Tumor Depositional Embolization

Abnormal metabolism and blood supply/O2 imbalance in tumor cells affect drug transport delivery and increase the difficulty of tumor treatment. Controlling tumor growth by inhibiting tumor cell metabolism and regulating progressive embolization in the tumor region provides an innovative basis for constructing tumor therapeutic models. A highly biocompatible and efficient O2-depleting agent has been investigated to enable in situ precipitation and embolization within the tumor microenvironment. In situ deformation embolizer, Fe-GA@CaCO3 nano-assembly (GA: gallic acid), can convert into the large granular size embolization components of Fe(III) precipitates and affluent Ca2+ within the tumor microenvironment. In situ progressive O2 depletion produces Fe(III) precipitates that embolize tumor regions, isolating O2 and nutrients by blocking supply. Meanwhile, affluent Ca2+ acts on the intracellular, causing mitochondrial dysfunction through calcium overload and contributing to irreversible tumor cell damage. Both internal and external routes work synergistically to produce precise functional inhibition of tumors from the inside out, simultaneously responding to both intracellular and the corresponding tumor regions, providing an innovative solution for anti-tumor therapy.

Surface functionalized perovskite nanocrystals: a design strategy for organelle-specific fluorescence lifetime multiplexing

Fluorescent molecules or materials with high photoluminescence quantum yields and stability towards photobleaching are ideally suited for multiplex imaging. Despite complying with such properties, perovskite nanocrystals (Pv-NCs) are rarely used for bioimaging owing to their toxicity and limited stability in aqueous media and towards human physiology. We aim to address these deficiencies by designing core-shell structures with Pv-NCs as the core and surface-engineered silica as the shell (SiO2@Pv-NCs) since silica is recognized as a biologically benign carrier material and is known to be excreted through urine. The post-grafting methodology is adopted for developing [SiO2@Pv-NCs]tpm and [SiO2@Pv-NCs]tsy (tpm: triphenylphosphonium ion, tsy: tosylsulfonamide) for specific imaging of mitochondria and endoplasmic reticulum (ER) of the live HeLa cell, respectively. A subtle difference in their average fluorescence decay times ([SiO2@Pv-NCs]tpm: tpm τ av = 3.1 ns and [SiO2@Pv-NCs]tsy: tsy τ av = 2.1 ns) is used for demonstrating a rare example of perovskite nanocrystals in fluorescence lifetime multiplex imaging.

Harnessing GMNP-loaded BMSC-derived EVs to target miR-3064-5p via MEG3 overexpression: Implications for diabetic osteoporosis therapy in rats

Diabetic osteoporosis (DO) is a significant complication of diabetes, characterized by a decrease in bone mineral density and an increase in fracture risk. Magnetic nanoparticles (GMNPs) have emerged as potential drug carriers for various therapeutic applications. This study investigated the molecular mechanism of GMNPs loaded with bone marrow mesenchymal stem cell (BMSC) derived extracellular vesicles (EVs) overexpressing MEG3 target miR-3064-5p to induce NR4A3 for treating DO in rats. Initial analysis was carried out on GEO datasets GSE7158 and GSE62589, revealing a notable downregulation of NR4A3 in osteoporotic samples. Subsequent in vitro studies demonstrated the effective uptake of BMSC-EVs-MEG3 by osteoblasts and its potential to inhibit miR-3064-5p, activating the PINK1/Parkin signaling pathway and thus promoting mitochondrial autophagy, osteoblast proliferation, and differentiation. In vivo, experiments using DO rat models further substantiated the therapeutic efficacy of GMNPE-EVs-MEG3 in alleviating osteoporosis symptoms. In conclusion, GMNPs loaded with BMSC-EVs, through the delivery of MEG3 targeting miR-3064-5p, can effectively promote NR4A3 expression, activate the PINK1/Parkin pathway, and thereby enhance osteoblast proliferation and differentiation, offering a promising treatment for DO.

AI-assisted mass spectrometry imaging with in situ image segmentation for subcellular metabolomics analysis

Subcellular metabolomics analysis is crucial for understanding intracellular heterogeneity and accurate drug-cell interactions. Unfortunately, the ultra-small size and complex microenvironment inside the cell pose a great challenge to achieving this goal. To address this challenge, we propose an artificial intelligence-assisted subcellular mass spectrometry imaging (AI-SMSI) strategy with in situ image segmentation. Based on the nanometer-resolution MSI technique, the protonated guanine and threonine ions were respectively employed as the nucleus and cytoplasmic markers to complete image segmentation at the subcellular level, avoiding mutual interference of signals from various compartments in the cell. With advanced AI models, the metabolites within the different regions could be further integrated and profiled. Through this method, we decrypted the distinct action mechanism of isomeric drugs, doxorubicin (DOX) and epirubicin (EPI), only with a stereochemical inversion at C-4'. Within the cytoplasmic region, fifteen specific metabolites were discovered as biomarkers for distinguishing the drug action difference between DOX and EPI. Moreover, we identified that the downregulations of glutamate and aspartate in the malate-aspartate shuttle pathway may contribute to the higher paratoxicity of DOX. Our current AI-SMSI approach has promising applications for subcellular metabolomics analysis and thus opens new opportunities to further explore drug-cell specific interactions for the long-term pursuit of precision medicine.

Mitochondria-targetable small molecule fluorescent probes for the detection of cancer-associated biomarkers: A review

Cancer represents a global threat to human health, and effective strategies for improved cancer early diagnosis and treatment are urgently needed. The detection of tumor biomarkers has been one of the important auxiliary means for tumor screening and diagnosis. Mitochondria are crucial subcellular organelles that produce most chemical energy used by cells, control metabolic processes, and maintain cell function. Evidence suggests the close involvement of mitochondria with cancer development. As a consequence, the identification of cancer-associated biomarker expression levels in mitochondria holds significant importance in the diagnosis of early-stage diseases and the monitoring of therapy efficacy. Small-molecule fluorescent probes are effective for the identification and visualization of bioactive entities within biological systems, owing to their heightened sensitivity, expeditious non-invasive analysis and real-time detection capacities. The design principles and sensing mechanisms of mitochondrial targeted fluorescent probes are summarized in this review. Additionally, the biomedical applications of these probes for detecting cancer-associated biomarkers are highlighted. The limitations and challenges of fluorescent probes in vivo are also considered and some future perspectives are provided. This review is expected to provide valuable insights for the future development of novel fluorescent probes for clinical imaging, thereby contributing to the advancement of cancer diagnosis and treatment.

Selective Antitumor Effect and Lower Toxicity of Mitochondrion-Targeting Derivatization of Triptolide

Triptolide has a significant antitumor activity, but its toxicity limits its clinical application. As the mitochondrion-targeting strategy showed an advantage in selective antitumor effect based on the higher mitochondrial membrane potential (MMP) in tumor cells than normal cells, the lipophilic cations triphenylphosphonium and E-4-(1H-indol-3-yl vinyl)-N-methylpyridinium iodide (F16) were selected as targeting carriers for structural modification of triptolide. The derivatives bearing F16 generally retained most antitumor activities, overcame its inhibition plateau phenomena, and enhanced its selective antitumor effect in lung cancer. The representative derivative F9 could accumulate in the mitochondria of NCI-H1975 cells, inducing apoptosis and a dose-dependent increase in intracellular reactive oxygen species and reducing MMP. Moreover, no effects were observed in normal cells BEAS-2B. In vivo studies showed that the developmental, renal, and liver toxicities of F9 to zebrafish were significantly lower than those of triptolide. This study provides a promising idea to relieve the toxicity problem of triptolide.

A mitochondria-targeted multifunctional nanoplatform combining carbon monoxide delivery with O2-independent free radical burst under 1064 nm light irradiation for efficient hypoxic tumor therapy

In situ mitochondrial oxidative stress amplification is an effective strategy to improve efficacy of cancer treatment. In this work, a tumor and mitochondria dual-targeted multifunctional nanoplatform CMS@AIPH@PDA@COTPP@FA (CAPCTF) was prepared, in which a thermally decomposable radical initiator AIPH was loaded inside the mesoporores of CuxMoySz (CMS) nanoparticles with polydopamine (PDA) covered films that were further covalently functionalized by a mitochondria-targeted CO donor (COTPP) and a directing group of folic acid (FA). The prepared CAPCTF nanoplatform selectively accumulated in cancer cells and further targeted the mitochondrial organelle where carbon monoxide (CO) and O2-independent free radicals (•OH/•R) were in situ generated upon 1064 nm laser irradiation. Furthermore, the CMS nanocarrier was capable of depleting the GSH overexpressed in the tumor microenvironment (TME), thus preventing free radical scavenging. As a result, the CAPCTF nanoplatform exhibited outstanding in vitro and in vivo antitumor efficacy under hypoxic conditions. This provides an innovative strategy that combines O2-independent free radicals (•OH/•R) generation, CO delivery and GSH consumption to amplify intracellular oxidative stresses and induce mitochondrial dysfunction, thus leading to cancer cells eradication, which may have significant implications for personalized hypoxic tumor treatment.

Mitochondrial Metabolism: A New Dimension of Personalized Oncology

Energy is needed by cancer cells to stay alive and communicate with their surroundings. The primary organelles for cellular metabolism and energy synthesis are mitochondria. Researchers recently proved that cancer cells can steal immune cells' mitochondria using nanoscale tubes. This finding demonstrates the dependence of cancer cells on normal cells for their living and function. It also denotes the importance of mitochondria in cancer cells' biology. Emerging evidence has demonstrated how mitochondria are essential for cancer cells to survive in the harsh tumor microenvironments, evade the immune system, obtain more aggressive features, and resist treatments. For instance, functional mitochondria can improve cancer resistance against radiotherapy by scavenging the released reactive oxygen species. Therefore, targeting mitochondria can potentially enhance oncological outcomes, according to this notion. The tumors' responses to anticancer treatments vary, ranging from a complete response to even cancer progression during treatment. Therefore, personalized cancer treatment is of crucial importance. So far, personalized cancer treatment has been based on genomic analysis. Evidence shows that tumors with high mitochondrial content are more resistant to treatment. This paper illustrates how mitochondrial metabolism can participate in cancer resistance to chemotherapy, immunotherapy, and radiotherapy. Pretreatment evaluation of mitochondrial metabolism can provide additional information to genomic analysis and can help to improve personalized oncological treatments. This article outlines the importance of mitochondrial metabolism in cancer biology and personalized treatments.

Mitochondrial DNA-targeted therapy: A novel approach to combat cancer

Mitochondrial DNA (mtDNA) encodes proteins and RNAs that are essential for mitochondrial function and cellular homeostasis, and participates in important processes of cellular bioenergetics and metabolism. Alterations in mtDNA are associated with various diseases, especially cancers, and are considered as biomarkers for some types of tumors. Moreover, mtDNA alterations have been found to affect the proliferation, progression and metastasis of cancer cells, as well as their interactions with the immune system and the tumor microenvironment (TME). The important role of mtDNA in cancer development makes it a significant target for cancer treatment. In recent years, many novel therapeutic methods targeting mtDNA have emerged. In this study, we first discussed how cancerogenesis is triggered by mtDNA mutations, including alterations in gene copy number, aberrant gene expression and epigenetic modifications. Then, we described in detail the mechanisms underlying the interactions between mtDNA and the extramitochondrial environment, which are crucial for understanding the efficacy and safety of mtDNA-targeted therapy. Next, we provided a comprehensive overview of the recent progress in cancer therapy strategies that target mtDNA. We classified them into two categories based on their mechanisms of action: indirect and direct targeting strategies. Indirect targeting strategies aimed to induce mtDNA damage and dysfunction by modulating pathways that are involved in mtDNA stability and integrity, while direct targeting strategies utilized molecules that can selectively bind to or cleave mtDNA to achieve the therapeutic efficacy. This study highlights the importance of mtDNA-targeted therapy in cancer treatment, and will provide insights for future research and development of targeted drugs and therapeutic strategies.

Carnitine palmitoyltransferase 1A promotes mitochondrial fission by enhancing MFF succinylation in ovarian cancer

Mitochondria are dynamic organelles that are important for cell growth and proliferation. Dysregulated mitochondrial dynamics are highly associated with the initiation and progression of various cancers, including ovarian cancer. However, the regulatory mechanism underlying mitochondrial dynamics is still not fully understood. Previously, our study showed that carnitine palmitoyltransferase 1A (CPT1A) is highly expressed in ovarian cancer cells and promotes the development of ovarian cancer. Here, we find that CPT1A regulates mitochondrial dynamics and promotes mitochondrial fission in ovarian cancer cells. Our study futher shows that CPT1A regulates mitochondrial fission and function through mitochondrial fission factor (MFF) to promote the growth and proliferation of ovarian cancer cells. Mechanistically, we show that CPT1A promotes succinylation of MFF at lysine 302 (K302), which protects against Parkin-mediated ubiquitin-proteasomal degradation of MFF. Finally, the study shows that MFF is highly expressed in ovarian cancer cells and that high MFF expression is associated with poor prognosis in patients with ovarian cancer. MFF inhibition significantly inhibits the progression of ovarian cancer in vivo. Overall, CPT1A regulates mitochondrial dynamics through MFF succinylation to promote the development of ovarian cancer. Moreover, our findings suggest that MFF is a potential therapeutic target for ovarian cancer.

Mitochondria-Targeted COUPY Photocages: Synthesis and Visible-Light Photoactivation in Living Cells

Releasing bioactive molecules in specific subcellular locations from the corresponding caged precursors offers great potential in photopharmacology, especially when using biologically compatible visible light. By taking advantage of the intrinsic preference of COUPY coumarins for mitochondria and their long wavelength absorption in the visible region, we have synthesized and fully characterized a series of COUPY-caged model compounds to investigate how the structure of the coumarin caging group affects the rate and efficiency of the photolysis process. Uncaging studies using yellow (560 nm) and red light (620 nm) in phosphate-buffered saline medium have demonstrated that the incorporation of a methyl group in a position adjacent to the photocleavable bond is particularly important to fine-tune the photochemical properties of the caging group. Additionally, the use of a COUPY-caged version of the protonophore 2,4-dinitrophenol allowed us to confirm by confocal microscopy that photoactivation can occur within mitochondria of living HeLa cells upon irradiation with low doses of yellow light. The new photolabile protecting groups presented here complement the photochemical toolbox in therapeutic applications since they will facilitate the delivery of photocages of biologically active compounds into mitochondria.

Biopolymer Chitosan Surface Engineering with Magnesium Oxide-Pluronic-F127-Escin Nanoparticles on Human Breast Carcinoma Cell Line and Microbial Strains

Nanotechnology has been recognized as a highly interdisciplinary field of the twenty-first century, with diverse applications in biotechnology, healthcare, and material science. One of the most commonly employed non-toxic nanoparticles, magnesium oxide nanoparticles (MgO NPs), is simple, inexpensive, biocompatible, and biodegradable. Several researchers are interested in the biosynthesis process of MgO NPs through chemical and physical approaches. This is because of their simplicity, affordability, and environmental safety. In the current study, green MgO-Chitosan-Pluronic F127-Escin (MCsPFE) NPs have been synthesized and characterized via various techniques like UV-visible, Fourier-transform infrared spectroscopy, Energy dispersive X-ray composition analysis, Transmission electron microscopy, field emission scanning electron microscopy, X-ray Diffraction, Photoluminescence, and Dynamic light scattering analyses. The average crystallite size of MCsPFE NPs was 46 nm, and a face-centered cubic crystalline structure was observed. Further, the antimicrobial effectiveness of NPs against diverse pathogens has been assessed. The cytotoxic potential of the nanoparticles against MDA-MB-231 cell lines was evaluated using the MTT test, dual AO/EB, JC-1, DCFH-DA, and DAPI staining procedures. High antimicrobial efficacy of MCsPFE NPs against Gram-positive and Gram-negative bacterial strains as well as Candida albicans was observed. The findings concluded that the NPs augmented the ROS levels in the cells and altered the Δψm, leading to the initiation of the intrinsic apoptotic cell death pathway. Thus, green MCsPFE NPs possess immense potential to be employed as an effective antimicrobial and anticancer treatment option.

In Vitro and In Vivo Antitumor Assay of Mitochondrially Targeted Fluorescent Half-Sandwich Iridium(III) Pyridine Complexes

Half-sandwich iridium(III) complexes show potential value in the anticancer field. However, complexes with favorable luminescence performance are rare, which limits further investigation of the anticancer mechanism. In this paper, 10 triphenylamine-modified fluorescent half-sandwich iridium(III) pyridine complexes {[(η⁵-Cp^x)Ir(L)Cl₂]} (Ir1-Ir10) were prepared and showed potential antiproliferative activity, effectively inhibiting the migration of A549 cells. Ir6, showing the best activity among these complexes, exhibited excellent fluorescence performance (absolute fluorescence quantum yield of 15.17%) in solution. Laser confocal detection showed that Ir6 followed an energy-dependent cellular uptake mechanism, specifically accumulating in mitochondria (Pearson co-localization coefficient of 0.95). A Western blot assay further confirmed the existence of a mitochondrial apoptotic channel. Additionally, Ir6 could arrest the cell cycle at the G₂/M phase, catalyze NADH oxidation, reduce the mitochondrial membrane potential, induce an increase in the level of intracellular reactive oxygen species, and exhibit a mechanism of oxidation. An in vivo antitumor assay confirmed that Ir6 can effectively inhibit tumor growth and is safer than cisplatin.

Mitochondria-Targeting Polyprodrugs to Overcome the Drug Resistance of Cancer Cells by Self-Amplified Oxidation-Triggered Drug Release

The multi-drug resistance (MDR) of cancers is one of the main barriers for the success of diverse chemotherapeutic methods and is responsible for most cancer deaths. Developing efficient approaches to overcome MDR is still highly desirable for efficient chemotherapy of cancers. The delivery of targeted anticancer drugs that can interact with mitochondrial DNA is recognized as an effective strategy to reverse the MDR of cancers due to the relatively weak DNA-repairing capability in the mitochondria. Herein, we report on a polyprodrug that can sequentially target cancer cells and mitochondria using folic acid (FA) and tetraphenylphosphonium (TPP) targeting moieties, respectively. They were conjugated to the terminal groups of the amphiphilic block copolymer prodrugs composed of poly[oligo(ethylene glycol) methyl ether methacrylate] (POEGMA) and copolymerized monomers containing cinnamaldehyde (CNM) and doxorubicin (DOX). After self-assembly into micelles with the suitable size (∼30 nm), which were termed as TF@CNM + DOX, and upon intravenous administration, the micelles can accumulate in tumor tissues. After FA-mediated endocytosis, the endosomal acidity (∼pH 5) can trigger the release of CNM from TF@CNM + DOX micelles, followed by enhanced accumulation into the mitochondria via the TPP target. This promotes the overproduction of reactive oxygen species (ROS), which can subsequently enhance the intracellular oxidative stress and trigger ROS-responsive release of DOX into the mitochondria. TF@CNM + DOX shows great potential to inhibit the growth of DOX-resistant MCF-7 ADR tumors without observable side effects. Therefore, the tumor and mitochondria dual-targeting polyprodrug design represents an ideal strategy to treat MDR tumors through improvement of the intracellular oxidative level and ROS-responsive drug release.

Association of mitochondrial homeostasis and dynamic balance with malignant biological behaviors of gastrointestinal cancer

Mitochondria determine the physiological status of most eukaryotes. Mitochondrial dynamics plays an important role in maintaining mitochondrial homeostasis, and the disorder in mitochondrial dynamics could affect cellular energy metabolism leading to tumorigenesis. In recent years, disrupted mitochondrial dynamics has been found to influence the biological behaviors of gastrointestinal cancer with the potential to be a novel target for its individualized therapy. This review systematically introduced the role of mitochondrial dynamics in maintaining mitochondrial homeostasis, and further elaborated the effects of disrupted mitochondrial dynamics on the cellular biological behaviors of gastrointestinal cancer as well as its association with cancer progression. We aim to provide clues for elucidating the etiology and pathogenesis of gastrointestinal cancer from the perspective of mitochondrial homeostasis and disorder.

NDUFS4 promotes tumor progression and predicts prognosis in gastric cancer

Gastric cancer ranked third worldwide in terms of mortality. The immediate priority is to search for new prognosticative or therapeutic targets. This research aims to examine the function of the NADH:ubiquinone oxidoreductase subunit S4 (NDUFS4) in the malignant phenotype of gastric carcinoma. We analyzed the correlation between NDUFS4 expression and gastric cancer via bioinformatics analysis and cancer tissue microarray via immunohistochemistry. Also, we detected the phenotype change in gastric cancer cells after NDUFS4 was downregulated. NDUFS4's high expression in gastric cancer tissues showed an association with terminal TNM stage and unfavorable survival. Furthermore, downregulation of NDUFS4 decreased gastric cancer cell proliferation, migration and invasion. Nude mouse models revealed that NDUFS4 promotes tumor growth. This investigation highlights the prognostic role of NDUFS4 in gastric cancer. Our results also creatively ascertained NDUFS4 as a candidate for gastric cancer therapeutic targets.

Roles of Mitochondria in Oral Squamous Cell Carcinoma Therapy: Friend or Foe?

Oral squamous cell carcinoma (OSCC) therapy is unsatisfactory, and the prevalence of the disease is increasing. The role of mitochondria in OSCC therapy has recently attracted increasing attention, however, many mechanisms remain unclear. Therefore, we elaborate upon relative studies in this review to achieve a better therapeutic effect of OSCC treatment in the future. Interestingly, we found that mitochondria not only contribute to OSCC therapy but also promote resistance, and targeting the mitochondria of OSCC via nanoparticles is a promising way to treat OSCC.

Hesperetin, a Promising Dietary Supplement for Preventing the Development of Calcific Aortic Valve Disease

BACKGROUND

No effective therapeutic agents for calcific aortic valve disease (CAVD) are available currently. Dietary supplementation has been proposed as a novel treatment modality for various diseases. As a flavanone, hesperetin is widely abundant in citrus fruits and has been proven to exert protective effects in multiple diseases. However, the role of hesperetin in CAVD remains unclear.

METHODS

Human aortic valve interstitial cells (VICs) were isolated from aortic valve leaflets. A mouse model of aortic valve stenosis was constructed by direct wire injury (DWI). Immunoblotting, immunofluorescence staining, and flow cytometry were used to investigate the roles of sirtuin 7 (Sirt7) and nuclear factor erythroid 2-related factor 2 (Nrf2) in hesperetin-mediated protective effects in VICs.

RESULTS

Hesperetin supplementation protected the mice from wire-injury-induced aortic valve stenosis; in vitro, hesperetin inhibited the lipopolysaccharide (LPS)-induced activation of NF-κB inflammatory cytokine secretion and osteogenic factors expression, reduced ROS production and apoptosis, and abrogated LPS-mediated injury to the mitochondrial membrane potential and the decline in the antioxidant levels in VICs. These benefits of hesperetin may have been obtained by activating Nrf2-ARE signaling, which corrected the dysfunctional mitochondria. Furthermore, we found that hesperetin could directly bind to Sirt7 and that the silencing of Sirt7 decreased the effects of hesperetin in VICs and potently abolished the ability of hesperetin to increase Nrf2 transcriptional activation.

CONCLUSIONS

Our work demonstrates that hesperetin plays protective roles in the aortic valve through the Sirt7-Nrf2-ARE axis; thus, hesperetin might be a potential dietary supplement that could prevent the development of CAVD.

A novel deep learning-assisted hybrid network for plasmodium falciparum parasite mitochondrial proteins classification

Plasmodium falciparum is a parasitic protozoan that can cause malaria, which is a deadly disease. Therefore, the accurate identification of malaria parasite mitochondrial proteins is essential for understanding their functions and identifying novel drug targets. For classifying protein sequences, several adaptive statistical techniques have been devised. Despite significant gains, prediction performance is still constrained by the lack of appropriate feature descriptors and learning strategies in current systems. Moreover, good ground truth data is important for Artificial Intelligence (AI)-based models but there is a lack of that data in the literature. Therefore, in this work, we propose a novel hybrid network that combines 1D Convolutional Neural Network (CNN) and Bidirectional Gated Recurrent Unit (BGRU) to classify the malaria parasite mitochondrial proteins. Furthermore, we curate a sequential data that are collected from National Center for Biotechnology Information (NCBI) and UniProtKB/Swiss-Prot proteins databanks to prepare a dataset that can be used by the research community for AI-based algorithms evaluation. We obtain 4204 cases after preprocessing of the collected data and denote this set of proteins as PF4204. Finally, we conduct an ablation study on several conventional and deep models using PF4204 and the benchmark PF2095 datasets. The proposed model 'CNN-BGRU' obtains the accuracy values of 0.9096 and 0.9857 on PF4204 and PF2095 datasets, respectively. In addition, the CNN-BGRU is compared with state-of-the-arts, where the results illustrate that it can extract robust features and identify proteins accurately.

4-Octyl itaconate suppresses the osteogenic response in aortic valvular interstitial cells via the Nrf2 pathway and alleviates aortic stenosis in mice with direct wire injury

Calcific aortic valve disease (CAVD) is the most prevalent valvular heart disease in older individuals, but there is a lack of drug treatment. The cellular biological mechanisms of CAVD are still unclear. Oxidative stress and endoplasmic reticulum stress (ER stress) have been suggested to be involved in the progression of CAVD. Many studies have demonstrated that 4-octyl itaconate (OI) plays beneficial roles in limiting inflammation and oxidative injury. However, the potential role of OI in CAVD has not been thoroughly explored. Thus, we investigated OI-mediated modulation of ROS generation and endoplasmic reticulum stress to inhibit osteogenic differentiation in aortic valve interstitial cells (VICs). In our study, calcified aortic valves showed increased levels of ER stress and superoxide anion, as well as abnormal expression of Hmox1 and NQO1. In VICs, OI activated the Nrf2 signaling cascade and contributed to Nrf2 stabilization and nuclear translocation, thus augmenting the expression of genes downstream of Nrf2 (Hmox1 and NQO1). Moreover, OI ameliorated osteogenic medium (OM)-induced ROS production, mitochondrial ROS levels and the loss of mitochondrial membrane potential in VICs. Furthermore, OI attenuated the OM-induced upregulation of ER stress markers, osteogenic markers and calcium deposition, which were blocked by the Nrf2-specific inhibitor ML385. Interestingly, we found that OM-induced ER stress and osteogenic differentiation were ROS-dependent and that Hmox1 silencing triggered ROS production, ER stress and elevated osteogenic activity, which were inhibited by NAC. Overexpression of NQO1 mediated by adenovirus vectors significantly suppressed OM-induced ER stress and osteogenic markers. Collectively, these results showed the anti-osteogenic effects of OI on AVICs by regulating the generation of ROS and ER stress by activating the Nrf2 signaling pathway. Furthermore, OI alleviated aortic stenosis in a mouse model with direct wire injury. Due to its antioxidant properties, OI could be a potential drug for the prevention and/or treatment of CAVD.

Synthesis and antiproliferative activity of 6BrCaQ-TPP conjugates for targeting the mitochondrial heat shock protein TRAP1

A series of 6BrCaQ-C_n-TPP conjugates 3a-f and 5 was designed and synthesized as a novel class of TRAP1 inhibitors. Compound 3a displayed an excellent anti-proliferative activity with mean GI₅₀ values at a nanomolar level in a diverse set of human cancer cells (GI₅₀ = 0.008-0.30 μM) including MDA-MB231, HT-29, HCT-116, K562, and PC-3 cancer cell lines. Moreover, the best lead compound 6BrCaQ-C₁₀-TPP induces a significant mitochondrial membrane disturbance combined to a regulation of HSP and partner protein levels as a first evidence that his mechanism of action involves the TRAP-1 mitochondrial Hsp90 machinery.

COUPY Coumarins as Novel Mitochondria-Targeted Photodynamic Therapy Anticancer Agents

Photodynamic therapy (PDT) for cancer treatment has drawn increased attention over the last decades. Herein, we introduce a novel family of low-molecular-weight coumarins as potential PDT anticancer tools. Through a systematic study with a library of 15 compounds, we have established a detailed structure-activity relationship rationale, which allowed the selection of three lead compounds exhibiting effective in vitro anticancer activities upon visible-light irradiation in both normoxia and hypoxia (phototherapeutic indexes up to 71) and minimal toxicity toward normal cells. Acting as excellent theranostic agents targeting mitochondria, the mechanism of action of the photosensitizers has been investigated in detail in HeLa cells. The generation of cytotoxic reactive oxygen species, which has been found to be a major contributor of the coumarins' phototoxicity, and the induction of apoptosis and/or autophagy have been identified as the cell death modes triggered after irradiation with low doses of visible light.

Mitochondria-Targeting MoS2-Based Nanoagents for Enhanced NIR-II Photothermal-Chemodynamic Synergistic Oncotherapy

The synergy of chemodynamic therapy (CDT) and photothermal therapy (PTT) can improve anticancer efficacy, while the limited diffusion distance and the short lifetime of ^•OH still greatly restrict the therapeutic efficacy of PTT-CDT. Herein, MoS₂@PDA-Fe@PEG/TPP (MPFPT) nanosheets (NSs) with mitochondria-targeting ability were reported for enhanced PTT-CDT synergistic oncotherapy. MPFPT NSs were prepared by covalent modification of poly(ethylene glycol) (PEG) and triphenylphosphonium (TPP) on polydopamine (PDA)-Fe³⁺coated MoS₂ NSs. Co-localization experiments showed that MPFPT NSs can efficiently target mitochondria via the direction of TPP. Moreover, MPFPT NSs have good photothermal performance in the second near-infrared (NIR-II) region and can greatly accelerate the Fenton reaction from H₂O₂ to generate more hydroxyl radicals (^•OH). In vitro experimental results showed that MPFPT NSs have improved therapeutic efficacy to cancer cells than similar MoS₂-based nanoagents without mitochondria-targeting units, which can be attributed to the short distance between mitochondria and MPFPT NSs and the efficient damage of mitochondria by in situ generated ^•OH. In the 4T1 tumor-bearing mice model, MPFPT NSs demonstrated significantly enhanced therapeutic efficacy by PTT-CDT, suggesting the superiority of the mitochondria-targeting strategy. This study reveals that mitochondria-targeting MPFPT NSs are promising nanoagents for oncotherapy.

Ternary supramolecular nanocomplexes for superior anticancer efficacy of natural medicines

The discovery of effective anticancer drug delivery systems and elucidation of the mechanism are enormous challenges. Using two drug administration-approved biomaterials, we constructed a natural medicine (NM)-loaded ternary supramolecular nanocomplex (TSN) suitable for large-scale production. The TSN has a better effect against cancer cells/stem cells than NM with differentially upregulated (27 versus 59) and downregulated (165 versus 66) proteins, respectively. Treatment with the TSN induced apoptosis and G2/M arrest, inhibited cell proliferation, metastasis and invasion, reduced colony/sphere formation, and decreased the frequency of side population cells and CD133⁺CD44⁺ABCG2⁺ cells. These results were revealed by multiple analyses (proteomic analysis, transwell migration and colony/sphere formation assays, biomarker profiling, etc.). We first reported the proteomic analysis of small lung cancer cells responding to a drug or its nanovesicles. We first conducted a proteomic evaluation of tumor cells responding to a drug supramolecular nanosystem. The supramolecular conformation of the TSN and the interactions of the TSN with albumin were verified by molecular docking experiments. The dominant binding forces in the TSN complexation process were electrostatic interactions, van der Waalsinteractions and bond stretching. The TSN binds to albumin more readily than NM does. The TSN has good in situ absorptive and in vitro/vivo kinetic properties. The relative bioavailability of the TSN to EA was 458.39%. The NM-loaded TSN is a supramolecular vesicle that can be produced at an industrial scale for efficient cancer therapy.

Mitochondria-Targeted Nanomedicine for Enhanced Efficacy of Cancer Therapy

Nanomedicines have been designed and developed to deliver anticancer drugs or exert anticancer therapy more selectively to tumor sites. Recent investigations have gone beyond delivering drugs to tumor tissues or cells, but to intracellular compartments for amplifying therapy efficacy. Mitochondria are attractive targets for cancer treatment due to their important functions for cells and close relationships to tumor occurrence and metastasis. Accordingly, multifunctional nanoplatforms have been constructed for cancer therapy with the modification of a variety of mitochondriotropic ligands, to trigger the mitochondria-mediated apoptosis of tumor cells. On this basis, various cancer therapeutic modalities based on mitochondria-targeted nanomedicines are developed by strategies of damaging mitochondria DNA (mtDNA), increasing reactive oxygen species (ROS), disturbing respiratory chain and redox balance. Herein, in this review, we highlight mitochondria-targeted cancer therapies enabled by nanoplatforms including chemotherapy, photothermal therapy (PTT), photodynamic therapy (PDT), chemodynamic therapy (CDT), sonodynamic therapy (SDT), radiodynamic therapy (RDT) and combined immunotherapy, and discussed the ongoing challenges.

Alantolactone exhibits antiproliferative and apoptosis-promoting properties in colon cancer model via activation of the MAPK-JNK/c-Jun signaling pathway

Colorectal cancer (CRC) is one of the most common human malignancies in the digestive tract with high mortality. Alantolactone (ATL), as a plant-derived sesquiterpene lactone, has shown a variety of pharmacological activities, such as antibacterial, anti-inflammatory, anti-virus and so on. However, the exact molecular mechanism of ATL in colorectal cancer remains largely unknown. Here, we performed a study to explore the effect and mechanism of ATL on colorectal cancer. The CCK-8 assay, colony formation assay, Wound-healing and Transwell assays were performed to evaluate the cytotoxic effect, antiproliferative effect, anti-migratory and anti-invasive properties of ATL respectively. The xenograft tumor model was established in Balb/c mice to evaluate the anti-tumor effect. The expression levels of proteins involved the MAPK-JNK/c-Jun signaling pathway were measured by Western blot and RT-qPCR both in cells and tumor tissues. The results showed that ATL could inhibit the cells activities of various colon cancer cell lines. Moreover, ATL could induce HCT-116 cells nuclear pyknosis, mitochondrial membrane potential loss, G0/G1 phase arrest, as well as enhance the proportion of apoptosis cells and inhibit colony formation. The migration distance and invasion rate of cells were significantly reduced after treated with ATL. Additionally, in the xenograft model, ATL (50 mg/kg) significantly decreased the tumor tumor volume and weight (p < 0.001). For the anti-colon cancer mechanism, the ATL showed the anti-proliferative and pro-apoptosis effect by activating MAPK-JNK/c-Jun signaling pathway. In conclusion, ATL exhibits anti-proliferation and apoptosis-promoting potential in colon cancer via the activation of MAPK-JNK/c-Jun signaling pathway.

Mitochondria-targeted nanoparticles (mitoNANO): An emerging therapeutic shortcut for cancer

The early understanding of mitochondria posited that they were 'innocent organelles' solely devoted to energy production and utilisation. Intriguingly, recent findings have outlined in detail the 'modern-day' view that mitochondria are an important but underappreciated drug target. Mitochondria have been implicated in the pathophysiology of many human diseases, ranging from neurodegenerative disorders and cardiovascular diseases to infections and cancer. It is now clear that normal mitochondrial function involves the building blocks of a cell to generate lipids, proteins and nucleic acids thereby facilitating cell growth. On the other hand, mitochondrial dysfunction reprograms crucial cellular functions into pathological pathways, and is considered as an integral hallmark of cancer. Therefore, strategies to target mitochondria can provide a wealth of new therapeutic approaches in the fight against cancer, by overcoming a number of problems associated with conventional pharmaceutical drugs, including low solubility, poor bioavailability and non-selective biodistribution. The combination of nanoparticles with 'classical' chemotherapeutic drugs to create biocompatible, multifunctional mitochondria-targeted nanoplatforms has been recently studied. This approach is now rapidly expanding for targeted drug delivery systems, and for hybrid nanostructures that can be activated with light (photodynamic and/or photothermal therapy). The selective delivery of nanoparticles to mitochondria is an elegant shortcut to more selective, targeted, and safer cancer treatment. We propose that the use of nanoparticles to target mitochondria be termed "mitoNANO". The present minireview sheds light on the design and application of mitoNANO as advanced cancer therapeutics, that may overcome drug resistance and show fewer side effects.

Mitochondrial Voltage-Dependent Anion Channel 1-Hexokinase-II Complex-Targeted Strategy for Melanoma Inhibition Using Designed Multiblock Peptide Amphiphiles

Targeted therapies of melanoma are of urgent need considering the resistance of this aggressive type of cancer to chemotherapeutics. The voltage-dependent anion channel 1 (VDAC1)-hexokinase-II (HK-II) complex is an emerging target for novel anticancer therapies based on induced mitochondria-mediated apoptosis. The low cell membrane permeability of the anticancer 12-mer peptide N-Ter (RDVFTKGYGFGL) derived from the N-terminal fragment of the VDAC1 protein impedes the intracellular targeting. Here, novel multiblock VDAC1-derived cationic amphiphilic peptides (referred to as Pal-N-Ter-TAT, pFL-N-Ter-TAT, and Pal-pFL-N-Ter-TAT) are designed with a self-assembly propensity and cell-penetrating properties. The created multiblock amphiphilic peptides of partial α-helical conformations form nanoparticles of ellipsoid-like shapes and are characterized by enhanced cellular uptake. The amphiphilic peptides can target mitochondria and dissociate the VDAC1-HK-II complex at the outer mitochondrial membrane, which result in mitochondria-mediated apoptosis. The latter is associated with decrease of the mitochondrial membrane potential, cytochrome c release, and changes of the expression levels of the apoptotic proteins in A375 melanoma cells. Importantly, the mitochondrial VDAC1-derived amphiphilic peptides have a comparable IC₅₀ value for melanoma cells to a small-molecule drug, sorafenib, which has been previously used in clinical trials for melanoma. These results demonstrate the potential of the designed peptide constructs for efficient melanoma inhibition.

Mitochondria-targeted graphene for advanced cancer therapeutics

There have been numerous efforts to develop targeted therapies for treating cancer. The non-specificity of 'classical' cytotoxic chemotherapy drugs and drug resistance remain major challenges in cancer dormancy. Mitochondria-targeted therapy is an alternative strategy for the treatment of numerous cancer types and is heavily dependent on the ability of the anticancer drugs to reach the tumor mitochondria in a safe and selective manner. Over the past two decades, research efforts have provided mechanistic insights into the roles of mitochondria in cancer progression and therapies that specifically target cancer mitochondria. Given that several nanotechnology-driven strategies aimed at therapeutically targeting mitochondrial dysfunction are still in their infancy, this review considers the cross-disciplinary nature of this area and focuses on the design and development of mitochondria-targeted graphene (mitoGRAPH), its immense potential, and future use for selective targeting of cancer mitochondria. This review also provides novel insights into the strategies for preparing mitoGRAPH to destroy the cell powerhouse in a targeted fashion. Targeting mitochondria with graphene may represent an important therapeutic approach that transforms therapeutic interventions. STATEMENT OF SIGNIFICANCE: Mitochondria-targeted therapy represents a major advance for treating several medical conditions. At this time, no nanoparticles (NPs) or nanocarriers are clinically available, which are capable of spatial targeting and controlled delivery of drugs to mitochondria. NPs-based approaches have revolutionized the field of targeted therapy and have demonstrated efficacy for delivering drugs selectively to mitochondria. These NPs show limited results in pre-clinical animal models due to their adverse side effects and inadequate therapeutic outcomes. Over the past decade, graphene has emerged as a potential anticancer agent and has shown great potential in targeting tumor mitochondria in a safe and targeted fashion. This review considers recent advances in the use of mitochondria-targeted graphene (mitoGRAPH) in chemotherapy, photodynamic therapy, photothermal therapy, and combination therapies.

Mitochondrial Heteroplasmy Shifting as a Potential Biomarker of Cancer Progression

Cancer is a serious health problem with a high mortality rate worldwide. Given the relevance of mitochondria in numerous physiological and pathological mechanisms, such as adenosine triphosphate (ATP) synthesis, apoptosis, metabolism, cancer progression and drug resistance, mitochondrial genome (mtDNA) analysis has become of great interest in the study of human diseases, including cancer. To date, a high number of variants and mutations have been identified in different types of tumors, which coexist with normal alleles, a phenomenon named heteroplasmy. This mechanism is considered an intermediate state between the fixation or elimination of the acquired mutations. It is suggested that mutations, which confer adaptive advantages to tumor growth and invasion, are enriched in malignant cells. Notably, many recent studies have reported a heteroplasmy-shifting phenomenon as a potential shaper in tumor progression and treatment response, and we suggest that each cancer type also has a unique mitochondrial heteroplasmy-shifting profile. So far, a plethora of data evidencing correlations among heteroplasmy and cancer-related phenotypes are available, but still, not authentic demonstrations, and whether the heteroplasmy or the variation in mtDNA copy number (mtCNV) in cancer are cause or consequence remained unknown. Further studies are needed to support these findings and decipher their clinical implications and impact in the field of drug discovery aimed at treating human cancer.

Sirt3-mediated mitophagy regulates AGEs-induced BMSCs senescence and senile osteoporosis

Senile osteoporosis (SOP) is widely regarded as one of the typical aging-related diseases due to a decrease in bone mass and the destruction in microarchitecture. The inhibition of mitophagy can promote bone marrow mesenchymal stem cells (BMSCs) senescence, and increasing studies have shown that interventions targeting BMSCs senescence can ameliorate osteoporosis, exhibiting their potential for use as therapeutic strategies. Sirtuin-3 (Sirt3) is an essential mitochondria metabolic regulatory enzyme that plays an important role in mitochondrial homeostasis, but its role in bone homeostasis remains largely unknown. This study seeks to investigate whether advanced glycation end products (AGEs) accumulation aggravated BMSCs senescence and SOP, and explored the mechanisms underlying these effects. We observed that AGEs significantly aggravated BMSCs senescence, as well as promoted mitochondrial dysfunction and inhibited mitophagy in a concentration-dependent manner. In addition, this effect could be further strengthened by Sirt3 silencing. Importantly, we identified that the reduction of Sirt3 expression and the mitophagy were vital mechanisms in AGEs-induced BMSCs senescence. Furthermore, overexpression of Sirt3 by intravenously injection with recombinant adeno-associated virus 9 carrying Sirt3 plasmids (rAAV-Sirt3) significantly alleviated BMSCs senescence and the formation of SOP in SAMP6. In conclusion, our data demonstrated that Sirt3 protects against AGEs-induced BMSCs senescence and SOP. Targeting Sirt3 to improve mitophagy may represent a potential therapeutic strategy for attenuating AGEs-associated SOP.

Interactive Effects of Biosynthesized Nanocomposites and Their Antimicrobial and Cytotoxic Potentials

The present study investigated the biosynthesis of silver (AgNPs), zinc oxide (ZnONPs) and titanium dioxide (TiO2NPs) nanoparticles using Aspergillusoryzae, Aspergillusterreus and Fusariumoxysporum. Nanocomposites (NCs) were successfully synthesized by mixing nanoparticles using a Sonic Vibra-Cell VC/VCX processor. A number of analytical techniques were used to characterize the synthesized biological metal nanoparticles. Several experiments tested biologically synthesized metal nanoparticles and nanocomposites against two types of human pathogenic bacteria, including Gram-positive Staphylococcus aureus and methicillin-resistant Staphylococcus aureus (MRSA), and Gram-negative Escherichia coli and Pseudomonasaeruginosa. Additionally, the antitumor activity in HCT-116 cells (colonic carcinoma) was also evaluated. Significant antimicrobial effects of various synthesized forms of nanoparticles and nanocomposites against E. coli and P. aeruginosa bacteria were detected. Various synthesized biogenic forms of nanoparticles and nanocomposite (9.0 to 29 mm in diameter) had high antibacterial activity and high antitumor activity against HCT-116 cells (colonic carcinoma) with IC50 values of 0.7-100 µg/mL. Biosynthesized NPs are considered an alternative to large-scale biosynthesized metallic nanoparticles and nanocomposites, are simple and cost effective, and provide stable nanomaterials.

Exploring the crosstalk of glycolysis and mitochondrial metabolism in psychiatric disorders and brain tumours

Dysfunction of metabolic pathways characterises a plethora of common pathologies and has emerged as an underlying hallmark of disease phenotypes. Here, we focus on psychiatric disorders and brain tumours and explore changes in the interplay between glycolysis and mitochondrial energy metabolism in the brain. We discuss alterations in glycolysis versus core mitochondrial metabolic pathways, such as the tricarboxylic acid cycle and oxidative phosphorylation, in major psychiatric disorders and brain tumours. We investigate potential common patterns of altered mitochondrial metabolism in different brain regions and sample types and explore how changes in mitochondrial number, shape and morphology affect disease-related manifestations. We also highlight the potential of pharmacologically targeting mitochondria to achieve therapeutic effects.

Regulating glucose metabolism using nanomedicines for cancer therapy

The regulation of glucose metabolism is a research focus in cancer treatment. Glucose metabolism is essential for maintaining the growth and proliferation of tumor cells, thus offering us great opportunities for tumor treatment. Recently, much progress has been made in efficient cancer treatment by regulating the pathway of glucose metabolism with nanomedicines due to the rapid development of nanotechnology and promising drug targets. In this review, we first introduced the pathway of cell energy supply from the perspective of aerobic and anaerobic processes. Then, we discussed the recent research progress in regulating glucose metabolism for various tumor resistance strategies including heat resistance, multiple drug resistance, and hypoxia. Finally, we presented the prospects and challenges of developing multifunctional nanoagents for efficient chemotherapy, hyperthermia, dynamic therapy and so on by regulating glucose metabolism.

All-in-one mitochondria-targeted NIR-II fluorophores for cancer therapy and imaging

Small-molecule subcellular organelle-targeting theranostic probes are crucial for early disease diagnosis and treatment. The imaging window of these molecules is mainly focused on the visible and near-infrared region (below ∼900 nm) which limits the tissue penetration depth and therapeutic effects. Herein, a novel NIR-II small-molecule probe H4–PEG-Glu with a thiopyrylium cation was synthesized. H4–PEG-Glu not only can quickly and effectively image mitochondria in acute myeloid leukemia (AML) cells, and induce G₀/G₁ phase arrest by the intrinsic mitochondrial apoptosis pathway w/o irradiation, but also exhibit moderate cytotoxicity against AML cancer cells in a dose dependent-manner without laser irradiation. The THP-1 cells treated with H4–PEG-Glu upon NIR laser irradiation showed enhanced chemo- and photothermal therapy (CPTT) with 93.07% ± 6.43 apoptosis by Annexin V staining. Meanwhile, H4–PEG-Glu displayed high synergistic CPTT effects in vivo, as well as specific NIR-II tumor imaging in AML patient derived PDX mouse models for the first time. Our work lays down a solid foundation for designing small-molecule NIR-II mitochondria-selective theranostic probes.

Small-molecule subcellular organelle-targeting theranostic probes are crucial for early disease diagnosis and treatment.

The Regulation of Ferroptosis by Tumor Suppressor p53 and its Pathway

Tumor suppressor p53 plays a key role in tumor suppression. In addition to tumor suppression, p53 is also involved in many other biological and pathological processes, such as immune response, maternal reproduction, tissue ischemia/reperfusion injuries and neurodegenerative diseases. While it has been widely accepted that the role of p53 in regulation of cell cycle arrest, senescence and apoptosis contributes greatly to the function of p53 in tumor suppression, emerging evidence has implicated that p53 also exerts its tumor suppressive function through regulation of many other cellular processes, such as metabolism, anti-oxidant defense and ferroptosis. Ferroptosis is a unique iron-dependent form of programmed cell death driven by lipid peroxidation in cells. Ferroptosis has been reported to be involved in cancer, tissue ischemia/reperfusion injuries and neurodegenerative diseases. Recent studies have shown that ferroptosis can be regulated by p53 and its signaling pathway as well as tumor-associated mutant p53. Interestingly, the regulation of ferroptosis by p53 appears to be highly context-dependent. In this review, we summarize recent advances in the regulation of ferroptosis by p53 and its signaling pathway. Further elucidation of the role and molecular mechanism of p53 in ferroptosis regulation will yield new therapeutic strategies for cancer and other diseases, including neurodegenerative diseases and tissue ischemia/reperfusion injuries.

Mitochondrial DNA Mutation Analysis in Breast Cancer: Shifting From Germline Heteroplasmy Toward Homoplasmy in Tumors

Studies have suggested a potential role of somatic mitochondrial mutations in cancer development. To analyze the landscape of somatic mitochondrial mutation in breast cancer and to determine whether mitochondrial DNA (mtDNA) mutational burden is correlated with overall survival (OS), we sequenced whole mtDNA from 92 matched-paired primary breast tumors and peripheral blood. A total of 324 germline variants and 173 somatic mutations were found in the tumors. The most common germline allele was 663G (12S), showing lower heteroplasmy levels in peripheral blood lymphocytes than in their matched tumors, even reaching homoplasmic status in several cases. The heteroplasmy load was higher in tumors than in their paired normal tissues. Somatic mtDNA mutations were found in 73.9% of breast tumors; 59% of these mutations were located in the coding region (66.7% non-synonymous and 33.3% synonymous). Although the CO1 gene presented the highest number of mutations, tRNA genes (T,C, and W), rRNA 12S, and CO1 and ATP6 exhibited the highest mutation rates. No specific mtDNA mutational profile was associated with molecular subtypes of breast cancer, and we found no correlation between mtDNA mutational burden and OS. Future investigations will provide insight into the molecular mechanisms through which mtDNA mutations and heteroplasmy shifting contribute to breast cancer development.

Bufalin exerts antitumor effects in neuroblastoma via the induction of reactive oxygen species‑mediated apoptosis by targeting the electron transport chain

The prognosis of high-risk neuroblastoma remains poor. Clinical first-line drugs for treating neuroblastoma have been developed over the previous half-century; however, progress in the identification of new drugs with high efficiency is required. Bufalin, one of the major components of extracts obtained from the venom of the Chinese toad Bufo gargarizans, which is used to treat heart failure in Asian Pacific countries, has been reported to be a potential drug against multiple types of tumor; however, the detailed mechanisms underlying its antitumor activities remain unclear, largely due to lack of knowledge regarding its targets. In the present study, bufalin was revealed to exhibit potent antitumor effects against neuroblastoma, both in vitro and in vivo, using cell proliferation, colony formation, Transwell migration and flow cytometry assays, as well as a nude mouse subcutaneous xenograft model. Moreover, a chemically modified bufalin probe was designed to identify the potential targets of bufalin in neuroblastoma via chemical proteomics. With this strategy, it was revealed that the electron transport chain (ETC) on the inner membrane of mitochondria may contain potential targets for bufalin, and that bufalin-induced mitochondrial-dependent apoptosis may be caused by disruption of the ETC. Collectively, the present study suggests that bufalin may a promising drug for chemotherapy against neuroblastoma, and provides a foundation for further studies into the antitumor mechanisms of bufalin.

iASPP-Mediated ROS Inhibition Drives 5-Fu Resistance Dependent on Nrf2 Antioxidative Signaling Pathway in Gastric Adenocarcinoma

AIMS

Inhibitor for the apoptosis-stimulating protein of p53 (iASPP) has been reported to be correlated with 5-fluorouracil (5-Fu) resistance in renal cell carcinoma. Here, we uncover mechanisms of iASPP-Nrf2-ROS regulation of 5-Fu resistance which are important for the development of alternative treatment strategies for gastric adenocarcinoma treatment.

METHODS

We analyzed iASPP and Nrf2 through TCGA RNA-seq data, UALCAN analysis, and cBioPortal datasets. Intracellular ROS generation was determined by 2',7'-dichloro-fluorescin diacetate staining. Transwell was used to evaluate the invasion. The expression of iASPP, Nrf2, HO-1, and GSTP1 was tested using western blot.

RESULTS

We found that iASPP KD led to an apparent 5-Fu-induced ROS accumulation in MGC803 and SCG790 cells. Accompanied by iASPP KD, Nrf2 was markedly decreased. iASPP-induced ROS inhibition relies on Nrf2, and due to both knocked down iASPP and Nrf2, the level of ROS did not show an obvious difference with Nrf2 KD solely. Similarly, iASPP KD failed to enhance the Nrf2 KD-mediated ROS accumulation after 5-Fu treatment, suggesting that iASPP-induced antioxidative effects related to 5-Fu resistance are partially dependent on Nrf2. Also, the combination of iASPP KD and Nrf2 KD did not show any synergistic effect on apoptosis after 5-Fu treatment in MGC803 and SCG790 cells. Further studies revealed that iASPP KD or Nrf2 KD could decrease the expression of HO-1 and GSTP1.

CONCLUSIONS

Our data highlight that iASPP plays a crucial role in the inhibition of 5-Fu-induced apoptosis resistance by removing ROS accumulation in gastric adenocarcinoma, and that the removal of ROS induced by iASPP is Nrf2 signaling dependent.

Peptide Fibrillar Assemblies Exhibit Membranolytic Effects and Antimetastatic Activity on Lung Cancer Cells

Cancer metastasis is a central oncology concern that worsens patient conditions and increases mortality in a short period of time. During metastatic events, mitochondria undergo specific physiological alterations that have emerged as notable therapeutic targets to counter cancer progression. In this study, we use drug-free, cationic peptide fibrillar assemblies (PFAs) formed by poly(L-Lysine)-block-poly(L-Threonine) (Lys-b-Thr) to target mitochondria. These PFAs interact with cellular and mitochondrial membranes via electrostatic interactions, resulting in membranolysis. Charge repulsion and hydrogen-bonding interactions exerted by Lys and Thr segments dictate the packing of the peptides and enable the PFAs to display enhanced membranolytic activity toward cancer cells. Cytochrome c (cyt c), endonuclease G, and apoptosis-inducing factor were released from mitochondria after treatment of lung cancer cells, subsequently inducing caspase-dependent and caspase-independent apoptotic pathways. A metastatic xenograft mouse model was used to show how the PFAs significantly suppressed lung metastasis and inhibited tumor growth, while avoiding significant body weight loss and mortality. Antimetastatic activities of PFAs are also demonstrated by in vitro inhibition of lung cancer cell migration and clonogenesis. Our results imply that the cationic PFAs achieved the intended and targeted mitochondrial damage, providing an efficient antimetastatic therapy.

MPPIF-Net: Identification of Plasmodium Falciparum Parasite Mitochondrial Proteins Using Deep Features with Multilayer Bi-directional LSTM

Mitochondrial proteins of Plasmodium falciparum (MPPF) are an important target for anti-malarial drugs, but their identification through manual experimentation is costly, and in turn, their related drugs production by pharmaceutical institutions involves a prolonged time duration. Therefore, it is highly desirable for pharmaceutical companies to develop computationally automated and reliable approach to identify proteins precisely, resulting in appropriate drug production in a timely manner. In this direction, several computationally intelligent techniques are developed to extract local features from biological sequences using machine learning methods followed by various classifiers to discriminate the nature of proteins. Unfortunately, these techniques demonstrate poor performance while capturing contextual features from sequence patterns, yielding non-representative classifiers. In this paper, we proposed a sequence-based framework to extract deep and representative features that are trust-worthy for Plasmodium mitochondrial proteins identification. The backbone of the proposed framework is MPPF identification-net (MPPFI-Net), that is based on a convolutional neural network (CNN) with multilayer bi-directional long short-term memory (MBD-LSTM). MPPIF-Net inputs protein sequences, passes through various convolution and pooling layers to optimally extract learned features. We pass these features into our sequence learning mechanism, MBD-LSTM, that is particularly trained to classify them into their relevant classes. Our proposed model is experimentally evaluated on newly prepared dataset PF2095 and two existing benchmark datasets i.e., PF175 and MPD using the holdout method. The proposed method achieved 97.6%, 97.1%, and 99.5% testing accuracy on PF2095, PF175, and MPD datasets, respectively, which outperformed the state-of-the-art approaches.

Biodegradable nanofibrous temperature-responsive gelling microspheres for heart regeneration

Myocardial infarction (heart attack) is the number one killer of heart patients. Existing treatments for heart attack do not address the underlying problem of cardiomyocyte (CM) loss and cannot regenerate the myocardium. Introducing exogenous cardiac cells is required for heart regeneration due to the lack of resident progenitor cells and very limited proliferative potential of adult CMs. Poor retention of transplanted cells is the critical bottleneck of heart regeneration. Here, we report the invention of a poly(l-lactic acid)-b-poly(ethylene glycol)-b-poly(N-Isopropylacrylamide) copolymer and its self-assembly into nanofibrous gelling microspheres (NF-GMS). The NF-GMS undergo thermally responsive transition to form not only a 3D hydrogel after injection in vivo, but also exhibit architectural and structural characteristics mimicking the native extracellular matrix (ECM) of nanofibrous proteins and gelling proteoglycans or polysaccharides. By integrating the ECM-mimicking features, injectable form, and the capability of maintaining 3D geometry after injection, the transplantation of hESC-derived CMs carried by NF-GMS led to a striking 10-fold graft size increase over direct CM injection in an infarcted rat model, which is the highest reported engraftment to date. Furthermore, NF-GMS carried CM transplantation dramatically reduced infarct size, enhanced integration of transplanted CMs, stimulated vascularization in the infarct zone, and led to a substantial recovery of cardiac function. The NF-GMS may also serve as advanced injectable and integrative biomaterials for cell/biomolecule delivery in a variety of biomedical applications.

Dihydroartemisinin Induces Growth Arrest and Overcomes Dexamethasone Resistance in Multiple Myeloma

The discovery of artemisinin (ART) for malaria treatment won the 2015 Nobel Prize in Medicine, which inspired the rediscovery and development of ART for the treatment of other diseases including cancer. In this study, we investigated the potential therapeutic effect of ART and dihydroartemisinin (DHA) on multiple myeloma (MM) cells including primary MM cells and in 5TMM3VT mouse model. Both in vitro and in vivo experiments showed that DHA might be a more promising anti-MM agent with significantly improved efficacy compared to ART. Mechanistic analyses suggested that DHA activated the mitochondrial apoptotic pathway by interacting with ferrous (Fe2+) ions and oxygen to produce reactive oxygen species (ROS). Intriguingly, DHA could reverse the upregulated expression of B-cell lymphoma 2 (Bcl-2) protein, a typical mitochondrial apoptotic marker, induced by dexamethasone (Dexa) in MM. We further demonstrated that DHA treatment could overcome Dexa resistance and enhance Dexa efficacy in MM. Additionally, DHA combined with Dexa resulted in increased ROS production and cytochrome C translocation from the mitochondria to the cytoplasm, resulting in alterations to the mitochondrial membrane potential and caspase-mediated apoptosis. In summary, our study demonstrated that DHA was superior to ART in MM treatment and overcame Dexa resistance both in vitro and in vivo, providing a promising therapeutic strategy for MM therapy.