A novel lonidamine derivative targeting mitochondria to eliminate cancer stem cells by blocking glutamine metabolism

Reprogrammed glycolysis-induced augmentation of NIR-II excited photodynamic/photothermal therapy

Small molecule-based multifunctional optical diagnostic materials have garnered considerable interest due to their highly customizable structures, tunable excited-state properties, and remarkable biocompatibility. We herein report the synthesis of a multifaceted photosensitizer, PPQ-CTPA, which exhibits exceptional efficacy in generating Type I reactive oxygen species (ROS) and thermal energy under near-infrared-II (NIR-II, >1000 nm) laser excitation at 1064 nm, thereby combining photodynamic therapy (PDT) and photothermal therapy (PTT) functionalities. To enhance therapeutic efficacy, we engineered lonidamine (LND) by conjugating it with triphenylphosphonium (TPP) cations, producing LND-TPP. This compound inhibits mitochondrial glycolysis and downregulates heat shock protein 90 (HSP 90) levels in a breast cancer mouse model, potentiating both PDT and PTT. For in vivo applications, PPQ-CTPA and LND-TPP are encapsulated within the amphiphilic polymer DSPE-SS-PEG to obtain PPQ-CTPAL NPs. In breast cancer cell lines, PPQ-CTPAL NPs are decomposed by cellular GSH, simultaneously releasing the dual-functioning photosensitizer PPQ-CTPL and the mitochondria-disrupting agent LND-TPP. Upon 1064 nm laser irradiation, we found that tumor growth in breast cancer mice is effectively restrained by PPQ-CTPAL NPs. This work highlights the synergistic integration of PDT, PTT, and chemotherapy facilitated by NIR-II fluorescence, photoacoustic, and photothermal imaging under 1064 nm irradiation, underscoring the clinical potential of multifunctional phototherapeutic agents.

Cancer stem cells amino acid metabolism: Roles, mechanisms, and intervention strategies

Cancer stem cells (CSCs) are recognized as key drivers of tumor recurrence and therapy resistance due to their capacity for self-renewal and differentiation. Amino acid metabolic reprogramming, a hallmark of cancer, underpins CSC biology. Methionine, tryptophan, and glutamine support CSC survival and the maintenance of stemness, while proline plays a role in CSC differentiation and susceptibility to cell death. Consequently, the impact of amino acid metabolism on CSCs is multifaceted and complex. This review first outlines the intrinsic amino acid metabolic features of CSCs. It then provides a comprehensive analysis of the distinct roles of various amino acids in regulating CSC biology. Additionally, strategies targeting amino acid metabolism to eliminate CSCs in clinical therapies are discussed, offering new perspectives for the development of innovative tumor-targeting approaches.

Unexpected Discovery of a Novel Triphenylphosphonium Alkylalcohol That Triggers Cancer Cell Death via Mitophagy and Ferroptosis

Mitochondria-targeted delivery is a promising strategy in anticancer drug development. Triphenylphosphine cation (TPP+) is the most widely used mitochondrial-targeting carrier due to the elevated mitochondrial membrane potential (MMP) in cancer cells. Here, we report the serendipitous discovery of a mitochondrial-targeting carrier, compound 23, which exhibited potent anticancer activity (IC50 = 70 nM, HCC827) with minimal toxicity to normal cells. Compound 23 selectively accumulates in cancer cell mitochondria, induces MMP depolarization, and activates mitophagy via PINK1-Parkin pathway. It also disruptes mitochondrial functions, elevates ROS levels, and inhibits the xCT-GSH-GPX4 axis, leading to lipid peroxidation and ferroptotic cell death. In vivo, 23 significantly suppressed the growth of HCC827 xenograft tumors at 10 mg/kg. These findings support compound 23 as a highly selective and effective mitochondrial-targeting anticancer agent for further investigation.

Hyperbaric Oxygen Regulates Tumor pH to Boost Copper‐Doped Hydroxyethyl Starch Conjugate Nanoparticles Against Cancer Stem Cells

An extracellular acidic environment and an intracellular mildly alkaline environment induced by carbonic anhydrase 9 (CA9) play a critical role in self‐renewal, invasion, migration, and drug resistance of cancer stem cells (CSCs) within hypoxic solid tumors. Here, we report an antitumor strategy leveraging hyperbaric oxygen therapy (HBO) to regulate tumor pH and boost hydroxyethyl starch‐doxorubicin‐copper nanoparticles (HHD‐Cu NPs) against CSCs. HBO overcomes tumor hypoxia, downregulates pH‐regulatory proteins such as CA9, and leads to intracellular accumulation of acidic metabolites. As a result, HBO promotes intracellular acidification of both tumor cells and CSCs, triggering efficient doxorubicin release and the potent copper‐mediated chemical dynamic effect of subsequently administered dual‐acid‐responsive HHD‐Cu NPs. The combination of HBO with HHD‐Cu NPs not only eliminates tumor cells but also inhibits CSCs, altogether leading to potent tumor inhibition. This study explores a new function of clinical‐widely used HBO and establishes a novel combination therapy for treating CSCs abundant hypoxic solid tumors.

Mitochondria-Targeted Multifunctional Nanoprodrugs by Inhibiting Metabolic Reprogramming for Combating Cisplatin-Resistant Lung Cancer

How to address the resistance of cisplatin (CDDP) has always been a clinical challenge. The resistance mechanism of platinum-based drugs is very complex, including nuclear DNA damage repair, apoptosis escape, and tumor metabolism reprogramming. Tumor cells can switch between mitochondrial oxidative phosphorylation (OXPHOS) and glycolysis and develop resistance to chemotherapy drugs through metabolic variability. In addition, due to the lack of histone protection and a relatively weak damage repair ability, mitochondrial DNA (mtDNA) is more susceptible to damage, which in turn affects mitochondrial OXPHOS and can become a potential target for platinum-based drugs. Therefore, mitochondria, as targets of anticancer drugs, have become a hot topic in tumor resistance research. This study constructed a self-assembled nanotargeted drug delivery system LND-SS-Pt-TPP/HA-CD. β-Cyclodextrin-grafted hydronic acid (HA-CD)-encapsulated prodrug nanoparticles can target CD44 on the tumor surface and further deliver the prodrug to intracellular mitochondria through a triphenylphosphine group (TPP+). Disulfide bonds can be selectively degraded by glutathione (GSH) in mitochondria, releasing lonidamine (LND) and the cisplatin prodrug (Pt(IV)). Under the action of GSH and ascorbic acid, Pt(IV) is further reduced to cisplatin (Pt(II)). Cisplatin can cause mtDNA damage, induce mitochondrial dysfunction and mitophagy, and then affect mitochondrial OXPHOS. Meanwhile, LND can reduce the hexokinase II (HK II) level, induce destruction of mitochondria, and block energy supply by glycolysis inhibition. Ultimately, this self-assembled nano targeted delivery system can synergistically kill cisplatin-resistant lung cancer cells, which supplies an overcome cisplatin resistance choice via the disrupt mitochondria therapy.

GLS and GLS2 Glutaminase Isoenzymes in the Antioxidant System of Cancer Cells

A pathway frequently altered in cancer is glutaminolysis, whereby glutaminase (GA) catalyzes the main step as follows: the deamidation of glutamine to form glutamate and ammonium. There are two types of GA isozymes, named GLS and GLS2, which differ considerably in their expression patterns and can even perform opposing roles in cancer. GLS correlates with tumor growth and proliferation, while GLS2 can function as a context-dependent tumor suppressor. However, both isoenzymes have been described as essential molecules handling oxidant stress because of their involvement in glutathione production. We reviewed the literature to highlight the critical roles of GLS and GLS2 in restraining ROS and regulating both cellular signaling and metabolic stress due to their function as indirect antioxidant enzymes, as well as by modulating both reductive carboxylation and ferroptosis. Blocking GA activity appears to be a potential strategy in the dual activation of ferroptosis and inhibition of cancer cell growth in a ROS-mediated mechanism.

Strategic disruption of cancer's powerhouse: precise nanomedicine targeting of mitochondrial metabolism

Mitochondria occupy a central role in the biology of most eukaryotic cells, functioning as the hub of oxidative metabolism where sugars, fats, and amino acids are ultimately oxidized to release energy. This crucial function fuels a variety of cellular activities. Disruption in mitochondrial metabolism is a common feature in many diseases, including cancer, neurodegenerative conditions and cardiovascular diseases. Targeting tumor cell mitochondrial metabolism with multifunctional nanosystems emerges as a promising strategy for enhancing therapeutic efficacy against cancer. This review comprehensively outlines the pathways of mitochondrial metabolism, emphasizing their critical roles in cellular energy production and metabolic regulation. The associations between aberrant mitochondrial metabolism and the initiation and progression of cancer are highlighted, illustrating how these metabolic disruptions contribute to oncogenesis and tumor sustainability. More importantly, innovative strategies employing nanomedicines to precisely target mitochondrial metabolic pathways in cancer therapy are fully explored. Furthermore, key challenges and future directions in this field are identified and discussed. Collectively, this review provides a comprehensive understanding of the current state and future potential of nanomedicine in targeting mitochondrial metabolism, offering insights for developing more effective cancer therapies.

Glutaminolysis inhibition boosts photodynamic therapy to eliminate cancer stem cells

High reactive oxygen species (ROS) levels provide a therapeutic opportunity to eradicate cancer stem cells (CSCs), a population of cells responsible for tumorigenesis, progression, metastasis, and recurrence. However, enhanced antioxidant systems in this population of cells attenuate ROS-inducing therapies. Here, we developed a nanoparticle-assisted combination therapy to eliminate CSCs by employing photodynamic therapy (PDT) to yield ROS while disrupting ROS defense with glutaminolysis inhibition. Specifically, we leveraged an oleic acid-hemicyanine conjugate (CyOA) as photosensitizer, a new entity molecule HYL001 as glutaminolysis inhibitor, and a biocompatible folic acid-hydroxyethyl starch conjugate (FA-HES) as amphiphilic surfactant to construct cellular and mitochondrial hierarchical targeting nanomedicine (COHF NPs). COHF NPs inhibited glutaminolysis to reduce intracellular ROS scavengers, including glutathione (GSH) and nicotinamide adenine dinucleotide phosphate (NADPH), and to blunt oxidative phosphorylation (OXPHOS) for oxygen-conserved PDT. Compared to COLF NPs without glutaminolysis inhibitor, COHF NPs exhibited higher phototoxicity to breast cancer stem cells (BCSCs) both in vitro and in vivo. More importantly, we corroborated that marketed glutaminolysis inhibitors, such as CB839 and V9302, augment the clinically used photosensitizer (Hiporfin) for BCSCs elimination. This study develops a potent CSCs targeting strategy by combining glutaminolysis inhibition with PDT and provides significant implications for cancer therapy.

Hyperbaric Oxygen Boosts Antitumor Efficacy of Copper-Diethyldithiocarbamate Nanoparticles against Pancreatic Ductal Adenocarcinoma by Regulating Cancer Stem Cell Metabolism

Cuproptosis-based cancer nanomedicine has received widespread attention recently. However, cuproptosis nanomedicine against pancreatic ductal adenocarcinoma (PDAC) is severely limited by cancer stem cells (CSCs), which reside in the hypoxic stroma and adopt glycolysis metabolism accordingly to resist cuproptosis-induced mitochondria damage. Here, we leverage hyperbaric oxygen (HBO) to regulate CSC metabolism by overcoming tumor hypoxia and to augment CSC elimination efficacy of polydopamine and hydroxyethyl starch stabilized copper-diethyldithiocarbamate nanoparticles (CuET@PH NPs). Mechanistically, while HBO and CuET@PH NPs inhibit glycolysis and oxidative phosphorylation, respectively, the combination of HBO and CuET@PH NPs potently suppresses energy metabolism of CSCs, thereby achieving robust tumor inhibition of PDAC and elongating mice survival importantly. This study reveals novel insights into the effects of cuproptosis nanomedicine on PDAC CSC metabolism and suggests that the combination of HBO with cuproptosis nanomedicine holds significant clinical translation potential for PDAC patients.