Regulation of Nucleotide Metabolism with Nutrient-Sensing Nanodrugs for Cancer Therapy

A DNA damage-amplifying nanoagent for cancer treatment via two-way regulation of redox dyshomeostasis and downregulation of tetrahydrofolate

DNA damage-based therapy is widely used in cancer treatment, yet its therapeutic efficacy is constrained by the redox homeostasis and DNA damage repair mechanisms of tumor cells. To address these limitations and enhance the efficacy of DNA damage-based therapy, HA-CuH@MTX, a copper-histidine metal-organic complex (CuH) loaded with methotrexate (MTX) and modified with hyaluronic acid (HA), was developed to amplify the DNA damage induced. In vitro experiments demonstrated that the presence of both Cu+ and Cu2+ in HA-CuH@MTX enables two-way regulated redox dyshomeostasis (RDH), achieved through Cu+-catalyzed generation of •OH and Cu2+-mediated consumption of glutathione, thereby facilitating efficient DNA oxidative damage. In addition, DNA damage repair is synergistically inhibited by impairing nucleotide synthesis via histidine metabolism and MTX downregulation of tetrahydrofolate, a crucial raw material in nucleotide synthesis. In vivo experiments with 4T1 tumor-bearing mice demonstrate 83.6 % inhibition of tumor growth by HA-CuH@MTX. This work provides a new strategy to amplify the DNA damage caused by DNA damage-based cancer therapies, and holds great potential for improving their therapeutic efficacy.

Fasting-Mimicking Diet Facilitates Anti-tumor Therapeutic Effects by Nutrient-Sensitive Nanocomposites

Cancer cells support their uncontrolled proliferation primarily by regulating energy metabolism. Inhibiting tumor growth by blocking the supply of nutrients is an effective treatment strategy. Fasting-mimicking diet (FMD), as a low-calorie, low-protein, low-sugar, high-fat diet, can effectively reduce the nutrient supply to tumor cells. However, the significant biological barrier presented by the tumor microenvironment imposes greater demands and challenges for drug design. This study constructs the multifunctional nanocomposite ZnFe2O4@TiO2@CHC@Orl-FA (ZTCOF), which has great potential to overcome the aforementioned drawbacks. ZnFe2O4@TiO2 could produce 1O2 with ultrasound, and stimulate the Fenton-like conversion of endogenous H2O2 to ·OH, achieving a combined therapeutic effect of sonodynamic therapy (SDT) and chemodynamic therapy (CDT). Orl (Orlistat) and CHC (α-cyano-4-hydroxycinnamic acid) not only block tumor cell energy metabolism but also increase sensitivity to reactive oxygen species, enhancing the cytotoxic effect on tumor cells. Furthermore, combining the treatment strategies with FMD condition control can further inhibit cancer cell energy metabolism, achieving significant synergistic anti-tumor therapy. Both in vitro and in vivo experiments confirm that ZTCOF with SDT/CDT/starvation can achieve effective tumor suppression and destruction. This work provides theoretical and technical support for anti-tumor multimodal synergistic therapy.

Organoid-Based Assessment of Metal-Organic Framework (MOF) Nanomedicines for Ex Vivo Cancer Therapy

Nanomaterials have been extensively exploited in tumor treatment, leading to numerous innovative strategies for cancer therapy. While nanomedicines present immense potential, their application in cancer therapy is characterized by significant complexity and unpredictability, especially regarding biocompatibility and anticancer efficiency. These considerations underscore the essential need for the development of ex vivo research models, which provide invaluable insights and understanding into the biosafety and efficacy of nanomedicines in oncology. Fortunately, the emergence of organoid technology offers a novel approach to the preclinical evaluation of the anticancer efficacy of nanomedicines in vitro. Hence, in this study, we constructed intestine and hepatocyte organoid models (Intestine-orgs and Hep-orgs) for assessing intestinal and hepatic toxicity at the microtissue level. We utilized three typical metal-organic frameworks (MOFs), ZIF-8, ZIF-67, and MIL-125, as nanomedicines to further detect their interactions with organoids. Subsequently, the MIL-125 with biocompatibility loaded methotrexate (MTX), forming the nanomedicine (MIL-125-PEG-MTX), indicated a high loading efficiency (82%) and a well-release capability in an acid microenvironment. More importantly, the anticancer effect of the nanomedicine was investigated using an in vitro patient-derived organoids (PDOs) model, achieving inhibition rates of 48% and 78% for PDO-1 and PDO-2, respectively, demonstrating that PDOs could predict clinical response and facilitate prospective therapeutic selection. These achievements presented great potential for organoid-based ex vivo models for nano theragnostic evaluation in biosafety and function.

Recent advances in nanomedicine for metabolism-targeted cancer therapy

Metabolism denotes the sum of biochemical reactions that maintain cellular function. Different from most normal differentiated cells, cancer cells adopt altered metabolic pathways to support malignant properties. Typically, almost all cancer cells need a large number of proteins, lipids, nucleotides, and energy in the form of ATP to support rapid division. Therefore, targeting tumour metabolism has been suggested as a generic and effective therapy strategy. With the rapid development of nanotechnology, nanomedicine promises to have a revolutionary impact on clinical cancer therapy due to many merits such as targeting, improved bioavailability, controllable drug release, and potentially personalized treatment compared to conventional drugs. This review comprehensively elucidates recent advances of nanomedicine in targeting important metabolites such as glucose, glutamine, lactate, cholesterol, and nucleotide for effective cancer therapy. Furthermore, the challenges and future development in this area are also discussed.

Effects of the periodic fasting-mimicking diet on health, lifespan, and multiple diseases: a narrative review and clinical implications

Dietary restriction and fasting have been recognized for their beneficial effects on health and lifespan and their potential application in managing chronic metabolic diseases. However, long-term adherence to strict dietary restrictions and prolonged fasting poses challenges for most individuals and may lead to unhealthy rebound eating habits, negatively affecting overall health. As a result, a periodic fasting-mimicking diet (PFMD), involving cycles of fasting for 2 or more days while ensuring basic nutritional needs are met within a restricted caloric intake, has gained widespread acceptance. Current research indicates that a PFMD can promote stem cell regeneration, suppress inflammation, extend the health span of rodents, and improve metabolic health, among other effects. In various disease populations such as patients with diabetes, cancer, multiple sclerosis, and Alzheimer's disease, a PFMD has shown efficacy in alleviating disease symptoms and improving relevant markers. After conducting an extensive analysis of available research on the PFMD, it is evident that its advantages and potential applications are comparable to other fasting methods. Consequently, it is proposed in this review that a PFMD has the potential to fully replace water-only or very-low-energy fasting regimens and holds promise for application across multiple diseases.

Predicting prognosis outcomes of primary central nervous system lymphoma with high-dose methotrexate-based chemotherapeutic treatment using lipidomics

Background

Primary central nervous system lymphoma (PCNSL) is a rare extranodal lymphomatous malignancy which is commonly treated with high-dose methotrexate (HD-MTX)-based chemotherapy. However, the prognosis outcome of HD-MTX-based treatment cannot be accurately predicted using the current prognostic scoring systems, such as the Memorial Sloan-Kettering Cancer Center (MSKCC) score.

Methods

We studied 2 cohorts of patients with PCNSL and applied lipidomic analysis to their cerebrospinal fluid (CSF) samples. After removing the batch effects and features engineering, we applied and compared several classic machine-learning models based on lipidomic data of CSF to predict the relapse of PCNSL in patients who were treated with HD-MTX-based chemotherapy.

Results

We managed to remove the batch effects and get the optimum features of each model. Finally, we found that Cox regression had the best prediction performance (AUC = 0.711) on prognosis outcomes.

Conclusions

We developed a Cox regression model based on lipidomic data, which could effectively predict PCNSL patient prognosis before the HD-MTX-based chemotherapy treatments.

A Biodegradable Nucleotide Coordination Polymer for Enhanced NSCLC Therapy in Combination with Metabolic Modulation

Epidermal growth factor receptor tyrosine kinase inhibitors (EGFR-TKIs) in the treatment of non-small cell lung cancer (NSCLC) still face challenges of acquired resistance and non-negligible side effects. To overcome these limitations, a biodegradable coordination polymer using guanine deoxynucleotide and ferrous iron (dGNP) is developed for targeted delivery of EGFR-TKIs. dGNPs can efficiently target nucleoside transporters in tumor cells that are regulated by fasting-mimicking diet (FMD). Meanwhile, FMD can augment the therapeutic efficacy of EGFR-TKIs by suppressing EGFR tyrosine kinase phosphorylation and related downstream pathways. In vivo results demonstrate that EGFR-TKIs-laden dGNPs combined with FMD treatment exhibit superior antitumor efficacy and reduced side effect. This study provides an innovative approach to enhance the therapeutic efficacy of EGFR-TKIs through nucleotide nanocarrier and metabolic modulation.

Facile Fabrication of Dual-Activatable Gastrointestinal-Based Nanocarriers for Safe Delivery and Controlled Release of Methotrexate

Colon cancer is emerging as one of the most common cancers worldwide, ranking in the top three in morbidity and mortality. Oral methotrexate (MTX) has been employed as a first-line treatment for various cancers, such as colon, breast, and lung cancer. However, the complexity and particularity of the gastrointestinal microenvironment and the limitations of MTX itself, including severe adverse effects and instability, are the main obstacles to the safe delivery of MTX to colon tumor sites. Herein, an innovative oral administrated anticancer therapeutic MTX@Am7CD/SDS NPs equipped with both pH and temperature sensitivity, which could effectively prevent MTX@Am7CD/SDS NPs from being degraded in the acidic environment mimicking the stomach and small intestine, thus harboring the potential to accumulate at the site of colon lesions and further release intestinal drug under mild conditions. In cellular assays, compared with free MTX, MTX@Am7CD/SDS NPs showed a favorable tumor inhibition effect on three tumor cell lines, as well as excellent cell uptake and apoptosis-inducing effect on SW480 cells. Therefore, this work provides a feasible solution for the safe use of MTX in the treatment of colon cancer and even other intestinal diseases.

Evolution of Gold and Iron Oxide Nanoparticles in Conjugates with Methotrexate: Synthesis and Anticancer Effects

Au and Fe nanoparticles and their conjugates with the drug methotrexate were obtained by an environmentally safe method of metal-vapor synthesis (MVS). The materials were characterized by transmission and scanning electron microscopy (TEM, SEM), X-ray photoelectron spectroscopy (XPS), and small-angle X-ray scattering using synchrotron radiation (SAXS). The use of acetone as an organic reagent in the MVS makes it possible to obtain Au and Fe particles with an average size of 8.3 and 1.8 nm, respectively, which was established by TEM. It was found that Au, both in the NPs and the composite with methotrexate, was in the Au⁰, Au⁺ and Au³⁺ states. The Au 4f spectra for Au-containing systems are very close. The effect of methotrexate was manifested in a slight decrease in the proportion of the Au⁰ state-from 0.81 to 0.76. In the Fe NPs, the main state is the Fe³⁺ state, and the Fe²⁺ state is also present in a small amount. The analysis of samples by SAXS registered highly heterogeneous populations of metal nanoparticles coexisting with a wide proportion of large aggregates, the number of which increased significantly in the presence of methotrexate. For Au conjugates with methotrexate, a very wide asymmetric fraction with sizes up to 60 nm and a maximum of ~4 nm has been registered. In the case of Fe, the main fraction consists of particles with a radius of 4.6 nm. The main fraction consists of aggregates up to 10 nm. The size of the aggregates varies in the range of 20-50 nm. In the presence of methotrexate, the number of aggregates increases. The cytotoxicity and anticancer activity of the obtained nanomaterials were determined by MTT and NR assays. Fe conjugates with methotrexate showed the highest toxicity against the lung adenocarcinoma cell line and Au nanoparticles loaded with methotrexate affected the human colon adenocarcinoma cell line. Both conjugates displayed lysosome-specific toxicity against the A549 cancer cell line after 120 h of culture. The obtained materials may be promising for the creation of improved agents for cancer treatment.

Enhanced Sensitivity of Tumor Cells to Autophagy Inhibitors Using Fasting-Mimicking Diet and Targeted Lysosomal Delivery Nanoplatform

Autophagy is one of the key pathways for tumor cell survival and proliferation. Therefore, inhibition of autophagy has been extensively studied for cancer therapy. However, current autophagy inhibitors lack specificity and are ineffective in limiting tumor progression. Herein, we report a nanoplatform for tumor-site-targeted delivery of hydroxychloroquine (HCQ) using insulin-like growth factors 2 receptor (IGF2R)-targeted liposomes (iLipo-H). A fasting-mimicking diet (FMD) is used to increase the autophagy levels in tumor cells, thereby increasing the sensitivity of tumor cells to HCQ. In addition, FMD treatment upregulates the expression of IGF2R in tumor cells, but not normal cells. Consequently, iLipo-H nanoparticles efficiently accumulate at the tumor site under FMD condition. In vivo studies demonstrate that iLipo-H nanoparticles efficiently inhibit 4T1 tumor growth without obvious side effects, especially under FMD condition. This study provides a promising strategy to increase the sensitivity of tumor cells to autophagy inhibitors for effective cancer therapy.

A Novel Purine and Uric Metabolism Signature Predicting the Prognosis of Hepatocellular Carcinoma

Background: Hepatocellular carcinoma (HCC) is regarded as one of the most common cancers in the world with a poor prognosis. Patients with HCC often have abnormal purine and uric acid metabolism, but their relationship with prognosis is unclear.

Methods: Here, we collected the data of peripheral blood uric acid and clinical data in 50 patients with HCC and analyzed the relationship with prognosis. At the same time, the transcriptome sequencing data of TCGA and GEO databases were collected to analyze the changes in purine metabolic pathway activity and construct a prognosis prediction model. Based on the prognosis prediction model related to purine metabolism, we further looked for the differences in the immune microenvironment and molecular level and provided possible drug targets.

Results: We found that the level of serum uric acid was positively correlated with the prognosis of HCC. At the same time, purine metabolism and purine biosynthesis pathway activities were significantly activated in patients with a poor prognosis of HCC. The prognosis prediction model of HCC based on purine metabolism and purine biosynthesis pathway can accurately evaluate the prognosis of patients with HCC. Meanwhile, we found that there were significant changes in tumor immune infiltration microenvironment and biological function at the molecular level in patients with over-activation of purine metabolism and purine biosynthesis pathway. In addition, we found that uric acid level was positively correlated with peripheral blood leukocytes in HCC patients.

Conclusion: In this study, we found that the level of peripheral blood uric acid in patients with HCC is correlated with their prognosis. The prognosis of patients with HCC can be accurately predicted through the metabolic process of uric acid and purine.