Metabolic reprogramming based on RNA sequencing of gemcitabine-resistant cells reveals the FASN gene as a therapeutic for bladder cancer

Targeting Metabolic Reprogramming in Bladder Cancer Immunotherapy: A Precision Medicine Approach

Bladder cancer, as a highly heterogeneous malignant tumor of the urinary system, is significantly affected by tumor metabolic reprogramming in its response to immunotherapy. This review systematically elaborates on the molecular mechanisms of abnormal glucose and lipid metabolism in the bladder cancer microenvironment and immune escape, and discusses precision treatment strategies based on metabolic regulation. In the future, it will be necessary to combine spatiotemporal omics and artificial intelligence technologies to construct a multi-target intervention system for the metabolic-immune interaction network, promoting a paradigm shift in precision treatment for bladder cancer.

RNF112 Facilitates Ubiquitin-Mediated Degradation of c-Myc, Suppressing Proliferation, Migration and Lipid Synthesis in Bladder Cancer

The E3 ubiquitin ligase RNF112 is significantly downregulated in bladder cancer (BLCA) and is correlated with disease progression. In vitro and in vivo studies indicated that RNF112 suppresses BLCA cell proliferation, migration, and lipid synthesis. Mechanistically, RNF112 directly interacts with the MB II domain of MYC through its N-terminal zinc finger motif, and its catalytic site C97 facilitates K48-linked polyubiquitination of the K389 residue on the c-Myc protein, accelerating its degradation. Additionally, this research validated the interaction of c-Myc with the promoter of ATP citrate lyase (ACLY), a central enzyme of lipid metabolism, promoting its transcriptional activity. The restoration of c-Myc or ACLY expression attenuated the inhibitory effects of RNF112 on BLCA cell growth, migration, and lipid synthesis. In conclusion, this study confirmed that RNF112 suppressed the proliferation, migration, and lipid synthesis of BLCA cells by facilitating the ubiquitin-mediated degradation of c-Myc.

Role of ubiquitination-driven metabolisms in oncogenesis and cancer therapy

Ubiquitination represents one of the most critical post-translational modifications, comprising a multi-stage enzyme process that plays a pivotal role in a myriad of cellular biological activities. The deregulation of the processes of ubiquitination and deubiquitination is associated with the development of cancers and other diseases. This typescript reviews the impact of ubiquitination on metabolic processes, elucidating the regulatory functions of ubiquitination on pivotal enzymes within metabolic pathways in pathological contexts. It underscores the role of ubiquitination-driven metabolism disorders in the etiology of cancers, and oncogenesis, and highlights the potential therapeutic efficacy of targeting ubiquitination-driven enzymes in cancer metabolism, their combination with immune checkpoint inhibitors, and their clinical applications.

Metabolic landscape in bladder cancer

PURPOSE OF REVIEW

This review examines the existing literature on metabolic pathways associated with bladder cancer (BC) and investigates four domains: (1) diagnoses, (2) cancer classification (staging & grading), (3) tracking, and (4) treatment.

RECENT FINDINGS

A systematic search of relevant databases identified studies meeting predefined inclusion criteria. A diverse array of metabolic pathways was found to hold significant biological and clinical relevance to BC, with particular emphasis on amino acid (AA), lipid, nucleic acid (NA), and bioenergetic pathways. Recent studies have elucidated utilities for metabolomics in diagnosis of BC, staging and grading the disease, monitoring progression or recurrence, and informing treatment strategies. Specifically, fatty acids were observed to be upregulated by as much as 90-fold in studies focused on BC diagnosis, alongside the upregulation of AA metabolites. Metabolites such as AA, lipids, and aldehydes showed potential as diagnostic biomarkers for BC. NA metabolites were particularly effective in monitoring BC status postsurgical resection. Furthermore, metabolites from lipid, bioenergetic, and AA pathways demonstrated utility in predicting tumor cell sensitivity to chemotherapy.

SUMMARY

A broad spectrum of metabolic pathways and metabolites offers significant potential for applications in the diagnosis, staging, monitoring, and treatment of BC. These findings underscore the promise of metabolomics as a valuable tool in improving BC management and patient outcomes.

m6A modification of lipoyltransferase 1 inhibits bladder cancer progression by activating cuproptosis

Cuproptosis, a cell death process caused by copper ions, is mediated by protein lipidation related to lipoic acid metabolism. There is a close connection between cuproptosis and the progression and prognosis of various tumors. Here, we identified lipoyltransferase 1 (LIPT1), a key gene related to cuproptosis, was downregulated in bladder cancer (BLCA) and was associated with unfavorable patient prognosis. Restoring the LIPT1 expression in BLCA cells suppressed the proliferation and promoted cuproptosis. Moreover, the consequences of RNA sequencing and Bodipy staining showed that the metabolic pathway mediated by LIPT1 inhibited the accumulation of lipid droplets in cells, disrupted endoplasmic reticulum (ER) homeostasis, and promoted cell apoptosis. Additionally, overexpression of LIPT1 not only repressed the proliferation rate of BLCA cells in vitro but also in vivo. Mechanistically, YTH N6-Methyladenosine RNA Binding Protein F2 (YTHDF2) promoted the degradation of LIPT1 mRNA in a m6A-dependent manner. In summary, these conclusions reveal that LIPT1 promotes cuprotosis and ER stress to inhibit the progression of BLCA, indicating that LIPT1 will provide a powerful treatment direction and drug target for treating BLCA.

Cryo-Milled β-Glucan Nanoparticles for Oral Drug Delivery

Gemcitabine is a nucleoside analog effective against a number of cancers. However, it has an oral bioavailability of less than 10%, due to its high hydrophilicity and low permeability through the intestinal epithelium. Therefore, the aim of this project was to develop a novel nanoparticulate drug delivery system for the oral delivery of gemcitabine to improve its oral bioavailability. In this study, gemcitabine-loaded β-glucan NPs were fabricated using a film-casting method followed by a freezer-milling technique. As a result, the NPs showed a small particle size of 447.6 ± 14.2 nm, and a high drug entrapment efficiency of 64.3 ± 2.1%. By encapsulating gemcitabine into β-glucan NPs, a sustained drug release profile was obtained, and the anomalous diffusion release mechanism was analyzed, indicating that the drug release was governed by diffusion through the NP matrix as well as matrix erosion. The drug-loaded NPs had a greater ex vivo drug permeation through the porcine intestinal epithelial membrane compared to the plain drug solution. Cytotoxicity studies showed a safety profile of the β-glucan polymers, and the IC50s of drug solution and drug-loaded β-glucan NPs were calculated as 228.8 ± 31.2 ng·mL-1 and 306.1 ± 46.3 ng·mL-1, respectively. Additionally, the LD50 of BALB/c nude mice was determined as 204.17 mg/kg in the acute toxicity studies. Notably, pharmacokinetic studies showed that drug-loaded β-glucan NPs could achieve a 7.4-fold longer T1/2 and a 5.1-fold increase in oral bioavailability compared with plain drug solution. Finally, in vivo pharmacodynamic studies showed the promising capability of gemcitabine-loaded β-glucan NPs to inhibit the 4T1 breast tumor growth, with a 3.04- and 1.74-fold reduction compared to the untreated control and drug solution groups, respectively. In conclusion, the presented freezer-milled β-glucan NP system is a suitable drug delivery method for the oral delivery of gemcitabine and demonstrates a promising potential platform for oral chemotherapy.

Cellular senescence and metabolic reprogramming model based on bulk/single-cell RNA sequencing reveals PTGER4 as a therapeutic target for ccRCC

Clear cell renal cell carcinoma (ccRCC) is the prevailing histological subtype of renal cell carcinoma and has unique metabolic reprogramming during its occurrence and development. Cell senescence is one of the newly identified tumor characteristics. However, there is a dearth of methodical and all-encompassing investigations regarding the correlation between the broad-ranging alterations in metabolic processes associated with aging and ccRCC. We utilized a range of analytical methodologies, such as protein‒protein interaction network analysis and least absolute shrinkage and selection operator (LASSO) regression analysis, to form and validate a risk score model known as the senescence-metabolism-related risk model (SeMRM). Our study demonstrated that SeMRM could more precisely predict the OS of ccRCC patients than the clinical prognostic markers in use. By utilizing two distinct datasets of ccRCC, ICGC-KIRC (the International Cancer Genome Consortium) and GSE29609, as well as a single-cell dataset (GSE156632) and real patient clinical information, and further confirmed the relationship between the senescence-metabolism-related risk score (SeMRS) and ccRCC patient progression. It is worth noting that patients who were classified into different subgroups based on the SeMRS exhibited notable variations in metabolic activity, immune microenvironment, immune cell type transformation, mutant landscape, and drug responsiveness. We also demonstrated that PTGER4, a key gene in SeMRM, regulated ccRCC cell proliferation, lipid levels and the cell cycle in vivo and in vitro. Together, the utilization of SeMRM has the potential to function as a dependable clinical characteristic to increase the accuracy of prognostic assessment for patients diagnosed with ccRCC, thereby facilitating the selection of suitable treatment strategies.