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Intrinsic or acquired resistance to chemical drugs severely limits their therapeutic efficacy in cancer treatment. Various intracellular antioxidant molecules, particularly glutathione (GSH), play a crucial role in maintaining intracellular redox homeostasis by mitigating the overproduced reactive oxygen species (ROS) due to rapid cell proliferation. Notably, these antioxidants also eliminate chemical-drug-induced ROS, eventually diminishing their cytotoxicity and rendering them less effective. In this study, we combined erastin, a GSH biosynthesis inhibitor, with 2'-deoxy-5-fluorouridine 5'-monophosphate sodium salt (FdUMP), an ROS-based drug, to effectively disrupt intracellular redox homeostasis and reverse chemotherapy resistance. Therefore, efficient ferroptosis and apoptosis were simultaneously induced for enhanced antitumor effects. Additionally, we employed small interfering RNA targeting PD-L1 (siPD-L1) as a third agent to block immune-checkpoint recognition by CD8 + T cells. The highly immunogenic cell peroxidates or damage-associated molecular patterns (DAMPs) induced by erastin acted synergistically with downregulated PD-L1 to enhance the antitumor effects. To codeliver these three drugs simultaneously and efficiently, we designed GE11 peptide-modified lipid nanoparticles (LNPs) containing calcium phosphate cores to achieve high encapsulation efficiencies. In vitro studies verified its enhanced cytotoxicity, efficient intracellular ROS induction and GSH/GPX4 downregulation, substantial lipid peroxidation product accumulation, and mitochondrial depolarization. In vivo , this formulation effectively accumulated at tumor sites and achieved significant tumor inhibition in subcutaneous colon cancer (CRC) mouse models with a maximum tumor inhibition rate of 83.89% at a relatively low dose. Overall, a strategy to overcome clinical drug resistance was verified in this study by depleting GSH and activating adaptive immunity.

Lipid-structured vesicles have been applied for drug delivery system for over 50 years. Based on their origin, lipid-structured vesicles are divided into two main categories, namely synthetic lipid vesicles (SLNVEs) and vesicles of mammalian origin (MDVEs). Although SLNVEs can stably transport anti-cancer drugs, their biocompatibility is poor and degradation of exogenous substances is a potential risk. Unlike SLNVEs, MDVEs have excellent biocompatibility but are limited by a lack of stability and a risk of contamination by dangerous pathogens from donor cells. Since the first discovery of plant-derived vesicles (PDVEs) in carrot cell supernatants in 1967, emerging evidence has shown that PDVEs integrate the advantages of both SLNVEs and MDVEs. Notably, 55 years of dedicated research has indicated that PDVEs are an ideal candidate vesicle for drug preparation, transport, and disease treatment. The current review systematically focuses on the role of PDVEs in cancer therapy and in particular compares the properties of PDVEs with those of conventional lipid vesicles, summarizes the preparation methods and quality control of PDVEs, and discusses the application of PDVEs in delivering anti-cancer drugs and their underlying molecular mechanisms for cancer therapy. Finally, the challenges and future perspectives of PDVEs for the development of novel therapeutic strategies against cancer are discussed., Competing Interests: The authors report no conflicts of interest in this work., (© 2023 Zhao et al.)

Background: Metastasis represents the leading cause of death in patients with breast cancer. Traditional Chinese medicine is particularly appreciated for metastatic diseases in Asian countries due to its benefits for survival period prolongation and immune balance modulation. However, the underlying molecular mechanisms remain largely unknown. This study aimed to explore the antimetastatic effect and immunomodulatory function of a clinical formula Aiduqing (ADQ)., Methods: Naive CD4 + T cells, regulatory T cells (Tregs), and CD8 + T cells were sorted by flow cytometry. Then, breast cancer cells and these immune cells were co-cultured in vitro or co-injected into mice in vivo to simulate their coexistence. Flow cytometry, ELISA, qPCR, double luciferase reporter gene assay, and chromatin immunoprecipitation assay were conducted to investigate the immunomodulatory and antimetastatic mechanisms of ADQ., Results: ADQ treatment by oral gavage significantly suppressed 4T1-Luc xenograft growth and lung metastasis in the orthotopic breast cancer mouse model, without noticeable hepatotoxicity, nephrotoxicity, or hematotoxicity. Meanwhile, ADQ remodeled the immunosuppressive tumor microenvironment (TME) by increasing the infiltration of tumor-infiltrating lymphocytes (TILs) and cytotoxic CD8 + T cells, and decreasing the infiltration of Tregs, naive CD4 + T cells, and tumor-associated macrophages (TAMs). Molecular mechanism studies revealed that ADQ remarkably inhibited CXCL1 expression and secretion from TAMs and thus suppressed the chemotaxis and differentiation of naive CD4 + T cells into Tregs, leading to the enhanced cytotoxic effects of CD8 + T cells. Mechanistically, TAM-derived CXCL1 promoted the differentiation of naive CD4 + T cells into Tregs by transcriptionally activating the NF-κB/FOXP3 signaling. Lastly, mouse 4T1-Luc xenograft experiments validated that ADQ formula inhibited breast cancer immune escape and lung metastasis by suppressing the TAM/CXCL1/Treg pathway., Conclusions: This study not only provides preclinical evidence supporting the application of ADQ in inhibiting breast cancer metastasis but also sheds novel insights into TAM/CXCL1/NF-κB/FOXP3 signaling as a promising therapeutic target for Treg modulation and breast cancer immunotherapy. Video Abstract., (© 2021. The Author(s).)

Background: The current approach for treating colorectal cancer favors the use of drug and gene combination therapy, and targeted nano-systems are gaining considerable attention for minimizing toxicity and improving the efficacy of anticancer treatment. The aim of this study was to develop ligand-modified, irinotecan and gene co-loaded lipid-polymer hybrid nanocarriers for targeted colorectal cancer combination therapy., Methods: Hyaluronic acid modified, irinotecan and gene co-loaded LPNs (HA-I/D-LPNs) were prepared using a solvent-evaporation method. Their average size, zeta potential, drug and gene loading capacity were characterized. The in vitro and in vivo gene transfection and anti-tumor ability of this nano-system were evaluated on colorectal cancer cells and mice bearing colorectal cancer model., Results: HA-I/D-LPNs had a size of 182.3 ± 5.1, over 80% drug encapsulation efficiency and over 90% of gene loading capacity. The peak plasma concentration (C max ) and half-life (T 1/2 ) achieved from HA-I/D-LPNs were 41.31 ± 1.58 μg/mL and 12.56 ± 0.67 h. HA-I/D-LPNs achieved the highest tumor growth inhibition efficacy and the most prominent transfection efficiency in vivo., Conclusion: HA-I/D-LPNs exhibited the most remarkable tumor inhibition efficacy and best gene transfection efficiency in the tumor, which could prove the effects of the drug and gene combination therapy., Competing Interests: The authors report no conflict of interest in this paper., (© 2020 Wang et al.)

Long non-coding RNA taurine up-regulated gene 1 (TUG1) emerges as new players in gene regulation in several cancers; however, its mechanism of action in non-small cell lung cancer (NSCLC) has not been well-studied. Herein, we determined expression pattern of TUG1 in NSCLC and further identified its effect on the chemosensitivity of NSCLC. Low expression of TUG1 was found in NSCLC tissues obtained from non-responders to platinum-based chemotherapy and reflected poor overall survival. TUG1 overexpression was shown to inhibit cell proliferation, migration, invasion, but facilitate apoptosis and autophagy in NSCLC cells resistant to cisplatin (DDP). Smaller size of tumor xenografts of DDP resistant NSCLC cells in the presence of TUG1 demonstrated enhancement of chemosensitivity by TUG1 in vivo . High expression of miR-221 and low expression of PTEN were determined in cancer tissues obtained from non-responders to platinum-based chemotherapy and reflected poor overall survival. TUG1 inhibited miR-221 that targeted PTEN, as evidenced by an elevated expression of PTEN in the presence of miR-221 or the absence of TUG1. Our present study reveals a model of enhancement of chemosensitivity that consists of TUG1, miR-221 and PTEN. Modulation of their levels may offer a new approach for improving anti-tumor efficacy for chemotherapeutic agents in NSCLC.

To improve drug retention in carriers for amphiphilic asulacrine (ASL), a novel active loading method using micelle gradient was developed to fabricate the ASL-loaded multiseed liposomes (ASL-ML). The empty ML were prepared by hydrating a thin film with empty micelles. Then the micelles in liposomal compartment acting as 'micelle pool' drove the drug to be loaded after the outer micelles were removed. Some reasoning studies including critical micelle concentration (CMC) determination, influencing factors tests on entrapment efficiency (EE), structure visualization, and drug release were carried out to explore the mechanism of active loading, ASL location, and the structure of ASL-ML. Comparisons were made between pre-loading and active loading method. Finally, the extended drug retention capacity of ML was evaluated through pharmacokinetic, drug tissue irritancy, and in vivo anti-tumor activity studies. Comprehensive results from fluorescent and transmission electron microscope (TEM) observation, encapsulation efficiency (EE) comparison, and release studies demonstrated the formation of ML-shell structure for ASL-ML without inter-carrier fusion. The location of drug mainly in inner micelles as well as the superiority of post-loading to the pre-loading method , in which drug in micelles shifted onto the bilayer membrane was an additional positive of this delivery system. It was observed that the drug amphiphilicity and interaction of micelles with drug were the two prerequisites for this active loading method. The extended retention capacity of ML has been verified through the prolonged half-life, reduced paw-lick responses in rats, and enhanced tumor inhibition in model mice. In conclusion, ASL-ML prepared by active loading method can effectively load drug into micelles with expected structure and improve drug retention.

Network pharmacology has become a powerful means of understanding the mechanisms underlying the action of Chinese herbs in cancer treatment. This study aims to validate the preventive effects and molecular mechanisms of a clinical prescription XIAOPI formula against breast cancer. In vivo breast cancer xenograft data showed that XIAOPI delayed breast cancer development and efficiently inhibited lung metastasis, accompanied by prolonged survival benefits and decreased cancer stem cell subpopulations. However, similar phenomenon were not observed in a cell model. The herb-ingredient-target network analysis further identified a total of 81 genes closely correlated with the breast cancer chemoprevention effects of XIAOPI. Cytokine array analysis further validated CXCL-1 as the key target of XIAOPI both in vitro and in vivo. Evaluation of the mechanism demonstrated that CXCL-1 administration significantly abrogated the metastatic inhibition effects of XIAOPI on breast cancer migration, invasion, stem cells subpopulations, epithelial-mesenchymal transition(EMT), or mammosphere formation abilities. Overall, our study provides experimental evidence and molecular mechanisms that may facilitate the safe and effective use of herbal medicine for the prevention of breast cancer growth or metastasis, and may lead to CXCL-1-based therapeutic strategies for mammary malignancies.

Isoliquiritigenin (ISL), a natural anti-breast cancer dietary compound, has poor delivery characteristics and low bioavailability. In order to promote the therapeutic outcome of ISL, a tumor-targeting lipid-polymer hybrid nanoparticle (NP) system modified by tumor-homing iRGD peptides has been developed. The hybrid NPs were prepared by a modified single-step nanoprecipitation method to encapsulate ISL. iRGD peptides were anchored on the surface by a postinsertion method (ISL-iRGD NPs). The stable lipid-polymer structure of ISL-iRGD NPs, with high encapsulation and loading efficiency, was confirmed. Compared to free ISL and non-iRGD-modified counterparts, ISL-iRGD NPs showed higher cytotoxicity and cell apoptosis against the different type of breast cancer cells. This was attributable to higher cellular accumulation mediated by the iRGD-integrin recognition and the nanoscale effect. More importantly, based on the active tumor-tissue accumulation by iRGD peptides and the prolonged in vivo circulation by the stealth nanostructure, ISL-iRGD NPs displayed higher tumor-growth inhibition efficiency in 4T1-bearing breast-tumor mouse models. Therefore, the constructed iRGD modified lipid-polymer hybrid NPs would provide a promising drug-delivery strategy to improve ISL in anti-breast cancer efficacy., Competing Interests: Disclosure The authors report no conflicts of interest in this work.

Mulitdrug resistance (MDR) is one of critical factorslimiting the efficacy of cancer chemoor radiotherapy. Emerging evidence has indicated that MDR is a complex process regulated by multiple factors, among which stress response molecules are considered as central players. AMP-activated protein kinase (AMPK) is a major regulator balancing energy supply and ultimately protects cells from harmful stresses via coordinating multiple metabolic pathways Notably, AMPK activation was recently shown to mediate the metabolism reprogramming in drug resistant cancer cells including promoting Warburg effects and mitochondrial biogenesis. Furthermore, AMPK activity has also been shown to regulate the self-renewal ability of cancer stem cells that are often refractory to chemotherapy. In addition, AMPK phosphorylation was critical in mediating autophagy induction, a process demonstrated to be effective in chemosensitivity modulation via degrading cellular components to satisfy nutrients requirement under stressful condition. Meanwhile, drug discovery targeting AMPK has been developed to validate the pathological significance of AMPK in cancer prevention and treatment. Although conflicting evidence focusing on the AMPK modulation for cancer treatment is still remained, this might be attributed to differences in AMPK isotypes in specific tissues, off-targets effects, the degree and duration of drug administration and experimental setting of stress conditions. This review will focus on AMPK mediated resistance to cancer therapy and discuss its potential therapeutic implication and targeting drug development.

Prostate cancer is the most common malignancy diagnosed in males, and bone metastases remain a significant source of morbidity and mortality in this population. Ubiquitin ligase E3s and proteasomes were thought to play essential roles in the development of cancers, therefore, they were proposed as therapy targets for the treatment of solid and hematological malignancies. Bortezomib, well-known as a proteasome inhibitor, has been observed with exact anticancer effect both in cell and animal models for several solid tumor types, including prostate cancer. To explore activities of the ubiquitin ligase E3s WWP1, Smurf1 and Smurf2 in oncogenesis and bone metastasis of prostate cancer, as well as in the functional mechanism of bortezomib in preventing prostate cancer, transcription and expression levels of WWP1, Smurf1 and Smurf2 genes in cell lines or tissues of benign prostate hyperplasia and human prostate cancer with and without bone metastasis were tested. Moreover, human prostate cancer PC3 cell lines were treated with bortezomib at different concentration gradients and then their proliferation at different time points, mRNA and protein levels were investigated. The results indicated that transcription and expression levels of WWP1, Smurf1 and Smurf2 genes in prostate cancer without bone metastasis were significantly higher compared to those in benign prostate hyperplasia (P<0.05), whereas significantly lower than prostate cancer metastatic to bone (P<0.05). Furthermore, bortezomib reduced the transcription and expression levels of WWP1, Smurf1 and Smurf2 genes in prostate cancer cell lines in a dose-dependent manner, thus, inhibiting the proliferation of prostate cancer cells. Elevated transcription and expression levels of ubiquitin ligase E3s WWP1, Smurf1 and Smurf2 genes may be the mechanisms of occurrence, development and metastasis of prostate cancer. In addition, bortezomib can prevent prostate cancer and its bone metastasis by downregulating WWP1, Smurf1 and Smurf2.

Accumulating evidence has suggested that cancer stem cells (CSCs) are at the root of drug resistance, and recent studies have indicated that caveolin-1, a membrane transporter protein, is involved in the regulation of cancer chemoresistance and stem cell signaling. However, the current understanding of the role of caveolin-1 in breast cancer development remains controversial. Herein, we demonstrate that caveolin-1 expression was upregulated after breast cancer chemotherapy in vitro and in vivo, accompanied by co-overexpression of β-catenin and ATP-binding cassette subfamily G member 2 (ABCG2) signaling. Additionally, breast CSCs were enriched for caveolin-1 expression. Caveolin-1 silencing sensitized breast CSCs by limiting their self-renewal ability but promoting the differentiation process. β-catenin silencing prevented the enhanced chemoresistance of CSCs induced by caveolin-1 overexpression, indicating that β-catenin is an essential molecule responsible for caveolin-1-mediated action. Further mechanistic investigation revealed that caveolin-1 silencing could downregulate the β-catenin/ABCG2 pathway through glycogen synthase kinase 3 beta activation and Akt inhibition, resulting in increased β-catenin phosphorylation and proteasomal degradation. Clinical investigation also revealed a close correlation between caveolin-1 and β-catenin/ABCG2 signaling in breast cancer samples. Notably, caveolin-1 was highly elevated in triple-negative breast cancer, and caveolin-1 silencing significantly impaired the tumorigenicity and chemoresistance of breast CSCs in in vivo models. Overall, our study not only highlights the role of caveolin-1 in mediating the chemoresistance of breast CSCs via β-catenin/ABCG2 regulation but also provides novel approaches for future therapies targeting CSCs., (© The Author 2014. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.)

Head and neck cancer is one of the most morbid human malignancies with an overall poor prognosis and severely compromised quality of life. As a result, there is significant interest in developing adjuvant therapies to augment currently available treatment protocols. Curcumin has been found to possess anti-cancer activities via its effect on a variety of biological pathways. In this study, we showed that curcumin inhibits head and neck cancer cell growth through reduction of PGE2 receptor EP4 gene expression. Blockade of AMP-dependent kinase (AMPK), and p38 MAPK by either chemical inhibitors or siRNAs antagonized the inhibitory effect of curcumin on EP4 expression, which was reversed by metformin, an activator of AMPK. Curcumin induced PGC-1α protein that was blocked by compound C and SB239063. Silencing of PGC-1α reversed the effect of curcumin on EP4 protein. Overexpression of EP4 overcame the effect of curcumin on head and neck cancer cell growth. In addition, curcumin reduced Sp1 protein. Overexpression of Sp1 resisted the inhibitory effect of curcumin on EP4 promoter activity and protein expression. Interestingly, overexpression of PGC-1α further enhanced the inhibitory effect of curcumin on Sp1 protein expression that was blocked by SB239063. In conclusion, this study shows that curcumin inhibits EP4 gene expression dependent of AMPKα and p38 MAPK activation, this leads to reduction of Sp1 protein and binding to specific area in the EP4 gene promoter. The cross talks of AMPKα and p38 MAPK signaling, the kinase-mediated PGC-1α expression and reciprocity of PGC-1α and Sp1 enhance this process. This ultimately results in inhibition of head and neck cancer cell proliferation., (© 2013.)

Aerobic glycolysis is an important feature of cancer cells. In recent years, lactate dehydrogenase A (LDH-A) is emerging as a novel therapeutic target for cancer treatment. Seeking LDH-A inhibitors from natural resources has been paid much attention for drug discovery. Spatholobus suberectus (SS) is a common herbal medicine used in China for treating blood-stasis related diseases such as cancer. This study aims to explore the potential medicinal application of SS for LDH-A inhibition on breast cancer and to determine its bioactive compounds. We found that SS manifested apoptosis-inducing, cell cycle arresting and anti-LDH-A activities in both estrogen-dependent human MCF-7 cells and estrogen-independent MDA-MB-231 cell. Oral herbal extracts (1 g/kg/d) administration attenuated tumor growth and LDH-A expression in both breast cancer xenografts. Bioactivity-guided fractionation finally identified epigallocatechin as a key compound in SS inhibiting LDH-A activity. Further studies revealed that LDH-A plays a critical role in mediating the apoptosis-induction effects of epigallocatechin. The inhibited LDH-A activities by epigallocatechin is attributed to disassociation of Hsp90 from HIF-1α and subsequent accelerated HIF-1α proteasome degradation. In vivo study also demonstrated that epigallocatechin could significantly inhibit breast cancer growth, HIF-1α/LDH-A expression and trigger apoptosis without bringing toxic effects. The preclinical study thus suggests that the potential medicinal application of SS for inhibiting cancer LDH-A activity and the possibility to consider epigallocatechin as a lead compound to develop LDH-A inhibitors. Future studies of SS for chemoprevention or chemosensitization against breast cancer are thus warranted.

Dioscin has been shown to promote anticancer activity against several forms of cancers. However, its detailed molecular mechanisms have not been clearly clarified.In this study, we demonstrate that dioscin induces apoptosis in cancer cells through the induction of oxidative stress. Treatment with cancer cells in vitro with dioscin resulted in rapid generation of reactive oxygen species (ROS) and the induction of mitochondrial pathway apoptosis in human esophageal cancer cell line Kyse510. Inhibition of oxidative stress by the antioxidant N-acetylcysteine blocked the induction of apoptosis by dioscin, indicating that ROS generation is the primary mechanism responsible for the proapoptotic activity of dioscin. Proteomic analysis and protein gel blotting further revealed peroxiredoxins 1 and 6 (PRDX 1 and 6), which are implicated in ROS metabolism and apoptosis, were associated with the anticancer effects of dioscin. Meanwhile, overexpression of PRDX 1 and 6 significantly blocked the elevated ROS and apoptosis induced by dioscin. In conclusion, we suggest that PRDX1 and PRDX6 are key targets in the process of dioscin-induced apoptosis that involves intracellular elevated ROS.

This study assessed the therapeutic effect of and adverse reactions to pirarubicin (THP) chemotherapy in osteosarcoma patients with lung metastasis, and analyzed the relationship between THP therapeutic effect and expression of p-glycoprotein and topoisomerase-II. Osteosarcoma patients with lung metastases at relapse were given THP and then cisplatin (DDP) or ifosfamide (IFO). Overall survival in patients receiving THP was 31.00 +/- 7.98 months, progression-free survival was 13.00 +/- 2.46 months. Objective response and partial response rates were 46.88% and 40.63%, respectively. There were no differences in overall survival and progression-free survival between the THP+DDP and THP+IFO regimens. Adverse reactions to THP chemotherapy were mainly gastrointestinal and myelosuppression. The therapeutic effect of THP was correlated with the abrogated expression of pglycoprotein and/or topoisomerase-II positive expression. For osteosarcoma patients with secondary lung metastasis, THP-based chemotherapy regimens are safe and effective as a salvage chemotherapy option.

Ferroptosis, an iron-dependent cell death mechanism driven by an accumulation of lipid peroxides on cellular membranes, has emerged as a promising strategy to treat various diseases, including cancer. Ferroptosis inducers not only exhibit cytotoxic effects on multiple cancer cells, including drug-resistant cancer variants, but also hold potential as adjuncts to enhance the efficacy of other anti-cancer therapies, such as immunotherapy. In addition to synthetic inducers, natural compounds, such as artemisinin, can be considered ferroptosis inducers. Artemisinin, extracted from Artemisia annua L., is a poorly water-soluble antimalarial drug. For clinical applications, researchers have synthesized various water-soluble artemisinin derivatives such as dihydroartemisinin, artesunate, and artemether. Artemisinin and artemisinin derivatives (ARTEs) upregulate intracellular free iron levels and promote the accumulation of intracellular lipid peroxides to induce cancer cell ferroptosis, alleviating cancer development and resulting in strong anti-cancer effects in vitro and in vivo. In this review, we introduce the mechanisms of ferroptosis, summarize the research on ARTEs-induced ferroptosis in cancer cells, and discuss the clinical research progress and current challenges of ARTEs in anti-cancer treatment. This review deepens the current understanding of the relationship between ARTEs and ferroptosis and provides a theoretical basis for the clinical anti-cancer application of ARTEs in the future. [ABSTRACT FROM AUTHOR]

Two zinc-based porous metal-organic frameworks, ZJU-64 and ZJU-64-CH3, sharing the same crystal structure, have been synthesized from zinc ions, the biomolecular linker adenine, and carboxylate-based ligands, resulting in 3D frameworks with 1D channels (approximately 1.6 nm×1.9 nm). The materials ZJU-64 and ZJU-64-CH3 exhibit low toxicity by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium (MTT) assay, microscopy images, and cell-cycle analysis; this indicates their potential applications for human health care. The anticancer drug methotrexate (MTX) is successfully loaded into MOFs by a simple impregnation method and the drug payloads reach approximately 13.45 and 10.63 wt % for ZJU-64 and ZJU-64-CH3, respectively. The sustainable drug-release behavior of MTX from MTX-loaded ZJU-64 and ZJU-64-CH3 is detected for several days. The temperature-responsive deliveries of ZJU-64 and ZJU-64-CH3 reveal that hyperthermia can control the drug release and open up a new treatment which combines drug therapy and thermal therapy to kill more cancer cells with fewer side effects; this reveals the practical value of ZJU-64 and ZJU-64-CH3 as 'smart' drug carriers with more therapeutic efficacy. [ABSTRACT FROM AUTHOR]