Tumors In Mice Research Articles

Salidroside overcomes cisplatin resistance in ovarian cancer via the inhibition of CRNDE-mediated autophagy.

Cisplatin (DDP) resistance significantly affects the survival rate of patients with ovarian cancer (OC). Autophagy is recognized as a common cause of resistance to DDP. This study aimed to investigate the impact of salidroside on OC progression and explore its potential regulatory effects on DDP resistance and autophagy. A DDP-resistant A2780 (A2780/DDP) cell line was induced by exposure to increasing DDP concentrations. The protein levels of autophagy proteins (p62, Beclin-1, ATG5, and LC3 II/LC3 I), apoptosis proteins (cleaved caspase-3 and cleaved caspase-9), and PI3K/AKT/mTOR pathway were determined by western blotting. Autophagic vacuoles in cells were observed with LC3 dyeing with confocal fluorescent microscopy. Cell viability and apoptosis were evaluated by cell counting kit-8 assays and flow cytometry. RT-qPCR was conducted to measure the relative levels of various lncRNAs in A2780 or A2780/DDP cells. A xenograft model was established by subcutaneous injection of 1 × 107 A2780 cells into the posterior flank of nude mice. Tumor size and weight were recorded. The expression of Ki67, cleaved caspase-3 and LC3 in tumor tissues was assessed by immunohistochemistry staining. The biodistribution of DDP in organs and blood of normal nude mice and tumors of tumor-bearing mice was detected using the ICP-MS. Hematoxylin-eosin staining was used to assess the histopathological changes of kidney, liver, and spleen sections. For in vitro analysis, autophagy was enhanced in DDP-resistant A2780 cells. Additionally, salidroside inhibits DDP resistance to A2780 cells via autophagy inhibition. Mechanistically, salidroside downregulated CRNDE in DDP-resistant A2780 cells. CRNDE knockdown inhibited autophagy, while CRNDE overexpression reversed the protective effects of salidroside. Additionally, salidroside activated the PI3K/AKT/mTOR pathway in DDP-resistant A2780 cells, and inhibition of PI3K reversed the effect of salidroside on inhibiting autophagy and apoptosis of A2780/DDP cells. For in vivo analysis, salidroside inhibited tumor growth, autophagy, and nephrotoxicity of DDP. Additionally, salidroside downregulated CRNDE and activated PI3K/AKT/mTOR signaling in vivo. Salidroside prevents autophagy-mediated DDP resistance in OC by downregulating lncRNA CRNDE and activating the PI3K/AKT/mTOR pathway.

Design, Screening and Development of Asymmetric siRNAs Targeting the MYC Oncogene in Triple-Negative Breast Cancer.

Triple-negative breast cancer (TNBC) is a subtype of breast cancer that lacks hormone receptor and Her2 (ERBB2) expression, leaving chemotherapy as the only treatment option. The urgent need for targeted therapy for TNBC patients has led to the investigation of small interfering RNAs (siRNAs), which can target genes in a sequence-specific manner, unlike other drugs. However, the clinical translation of siRNAs has been hindered by the lack of an effective delivery system, except in the case of liver diseases. The MYC oncogene is commonly overexpressed in TNBC compared to other breast cancer subtypes. In this study, we used siRNA to target MYC in MDA-MB-231, MDA-MB-157, MDA-MB-436 and Hs-578T cells. We designed various symmetric and asymmetric (asiRNAs), screened them for in vitro efficacy, modified them for enhanced nuclease resistance and reduced off-target effects, and conjugated them with cholesterol (ChoL) and docosanoic acid (DCA) as a delivery system. DCA was conjugated to the 3' end of asiRNA by a cleavable phosphodiester linker for in vivo delivery. Our findings demonstrated that asiRNA-VP and Mod_asiRNA10-6 efficiently downregulated MYC and its downstream targets, including RRM2, RAD51 and PARP1. Moreover, in a tumor xenograft model, asiRNA-VP-DCA effectively knocked down MYC mRNA and protein expression. Remarkably, durable knockdown persisted for at least 46 days postdosing in mouse tumor xenografts, with no visible signs of toxicity, underscoring the safety of DCA-conjugated asiRNAs. In conclusion, this study developed novel asiRNAs, design platforms, validated modification patterns, and in vivo delivery systems specifically targeting MYC in TNBC.

Durable antitumor response via an oncolytic virus encoding decoy-resistant IL-18

BackgroundInterleukin-18 (IL-18), or interferon (IFN)-γ-inducing factor, potentiates T helper 1 and natural killer cell activation as well as CD8+ T-cell proliferation. Recombinant IL-18 has displayed limited clinical efficacy in part...

Testing Oncolytic Myxoma Virus in Immunocompetent Mouse Model for Cancer Therapy.

Oncolytic viruses (OVs) have emerged as a class of novel cancer immunotherapeutic. Members of both DNA and RNA viruses developed as OVs for treating diverse types of human cancers. Preclinical research assessing immunotherapeutic efficacy is an essential step toward further development of these OVs. Mice tumor model systems are widely used in preclinical oncolytic viral therapies for evaluating the treatment regimens' efficacy. However, choosing the most appropriate model for a study can be challenging. Here, we describe a simple method of establishing subcutaneous tumors in immunocompetent mice, intratumoral injection of the virus, measuring tumor burden, and studying the survival of mice for preclinical development of oncolytic myxoma virus (MYXV).

Role of ATP citrate lyase and its complementary partner on fatty acid synthesis in gastric cancer

ATP citrate lyase (ACLY) and acyl-CoA short-chain synthetases 2 (ACSS2) are key enzymes in lipid metabolism. We explored the role of ACLY in gastric cancer (GC) and the effect of ACLY and ACSS2 compensation on GC growth. We used immunohistochemistry to verify the expression level of ACLY in GC, shRNA to stably knock down the expression level of ACLY in GC cells. The expression levels of lipid metabolizing enzymes were verified by qPCR and WB, and targeted lipidomics and quantification of lipid metabolism-related indicators helped us to understand the changes in lipid metabolism. Finally, subcutaneous graft tumors validate our findings from in vitro experiments. ACLY is upregulated in GC tissues, downregulation of ACLY reduced lipid accumulation and inhibited GC proliferation, migration, and invasion in vitro. ACSS2 maintains cell growth by compensatory elevation to maintain fatty acid synthesis activity in ACLY-depleted GC cells. Inhibition of ACSS2 enhanced the inhibitory effect of downregulation of ACLY on the growth of transplanted tumors in nude mice. Downregulation of ACLY inhibited GC cell growth in vitro and in vivo. ACSS2 was compensated to increase to maintain cell growth in ACLY-depleted GC cells.

Spatial immune heterogeneity in a mouse tumor model after immunotherapy.

Cancer immunotherapy is increasingly used in clinical practice, but its success rate is reduced by tumor escape from the immune system. This may be due to the genetic instability of tumor cells, which allows them to adapt to the immune response and leads to intratumoral immune heterogeneity. The study investigated spatial immune heterogeneity in the tumor microenvironment and its possible drivers in a mouse model of tumors induced by human papillomaviruses (HPV) following immunotherapy. Gene expression was determined by RNA sequencing and mutations by whole exome sequencing. A comparison of different tumor areas revealed heterogeneity in immune cell infiltration, gene expression, and mutation composition. While the mean numbers of mutations with every impact on gene expression or protein function were comparable in treated and control tumors, mutations with high or moderate impact were increased after immunotherapy. The genes mutated in treated tumors were significantly enriched in genes associated with ECM metabolism, degradation, and interactions, HPV infection and carcinogenesis, and immune processes such as antigen processing and presentation, Toll-like receptor signaling, and cytokine production. Gene expression analysis of DNA damage and repair factors revealed that immunotherapy upregulated Apobec1 and Apobec3 genes and downregulated genes related to homologous recombination and translesion synthesis. In conclusion, this study describes the intratumoral immune heterogeneity, that could lead to tumor immune escape, and suggests the potential mechanisms involved.

Non-Genotoxic and Environmentally Relevant Lower Molecular Weight Polycyclic Aromatic Hydrocarbons Significantly Increase Tumorigenicity of Benzo[a]pyrene in a Lung Two-Stage Mouse Model

The World Health Organization has classified air pollution as a carcinogen, and polycyclic aromatic hydrocarbons (PAHs) are major components of air particulates of carcinogenic concern. Thus far, most studies focused on genotoxic high molecular weight PAHs; however, recent studies indicate potential carcinogenicity of the non-genotoxic lower molecular weight PAHs (LMW PAHs) that are found in indoor and outdoor air pollution as well as secondhand cigarette smoke. We hypothesize that LMW PAHs contribute to the promotion stage of cancer when combined with benzo[a]pyrene (B[a]P), a legacy PAH. We specifically determined the effects of an LMW PAH mixture containing 1-methylanthracene (1MeA), fluoranthene (Flthn), and phenanthrene (Phe) combined with B[a]P on lung tumor promotion. To test this hypothesis, we used a two-stage, initiation/promotion BALB/ByJ female lung tumor mouse model. The mice were initiated with 3-methylcholanthrene followed by exposures to B[a]P, the LMW PAH mixture, and the combination of the LMW PAH mixture plus B[a]P, all at 10 mg/kg. The LMW PAHs combined with B[a]P significantly increased the promotion and incidence of lung tumors over that of B[a]P alone. The LMW PAHs in the absence of B[a]P did not significantly promote tumors, indicating strong co-promotional activities. We further assessed the effects of these PAHs on other hallmarks of cancer, namely, bronchoalveolar lavage fluid inflammatory infiltrates, pro-inflammatory transcripts, KC protein content, and mRNA expression of the gap junction (Gja1) and epiregulin (Ereg) genes. The LMW PAHs increased the biomarkers of inflammation, decreased Gja1 expression, and increased Ereg expression, all consistent with tumor promotion. This study indicates that non-genotoxic LMW PAHs can contribute to the cancer process and warrants further studies to assess the carcinogenic risks of other LMW PAHs.

Beaveria bassiana (Balsamo) Vuillemin combined with cinnamaldehyde enhances anti-hepatocellular carcinoma effects of T cells by the PGC-1α/DRP1-regulated mitochondrial biogenesis and fission

Beaveria bassiana (Balsamo) Vuillemin (BEA) and cinnamaldehyde (CA), primarily derived from traditional Chinese medicine (TCM) named Bombyx batryticatus and Cinnamomum cassia, play an immunomodulatory role in different disease. Hepatocellular carcinoma (HCC) is a prevalent malignant tumor characterized by immune dysfunction. In this study, we investigated BEA and CA's regulate ability on T cell mitochondrial metabolism and anti-HCC effect. We used RT-qPCR, Western blot, Enzyme-linked immune sorbent assay (ELISA), Flow CytoMetry (FCM) methods to examine BEA and CA's regulation of T cell mitochondrial function and anti-HCC ability. Furthermore, the mechanism of PGC-1α/DRP1 pathway on the morphology and function of T cell mitochondria was investigated. Our data demonstrated that the administration of BEA and CA, either alone or in combination, effectively suppressed HCC growth and mitigated T cell apoptosis and mitochondrial dysfunction, assessed by mitochondrial reactive oxygen species (mitoROS), mitochondrial membrane potential (MMP) and ATP level. Moreover, BEA and CA could enhance the release of tumor-killing factors (Perforin (PF) and Granzyme B (Gzm B)) from T cells, inducing H22 cell apoptosis. Additionally, BEA and CA-treated T cell reinfusion into BALB/c nude HCC mice could significantly inhibited HCC growth by promoting T cell infiltration into tumor tissue. T cell mitochondrial biogenesis/fission balance and apoptosis in tumor mice were regulated by PGC-1α/DRP1 pathway. Our findings reveal that BEA and CA enhance anti-HCC effects of T cells by regulating mitochondrial biogenesis and fission through the PGC-1α/DRP1 pathway.

TIGIT and PD-L1 co-blockade promotes clonal expansion of multipotent, non-exhausted antitumor T cells by facilitating co-stimulation

Blockade of immune checkpoints PD-1 and TIGIT has demonstrated activity in mouse tumor models and human patients with cancer. Although these coinhibitory receptors can restrict signaling in CD8+ T cells by regulating their associated co-stimulatory receptors CD28 and CD226, the functional consequences of combining PD-1 and TIGIT blockade remain poorly characterized. In mouse tumor models, we show that combination blockade elicited CD226-driven clonal expansion of tumor antigen-specific CD8+ T cells. The expanded clones emerged from a population of stem-like cells in draining lymph nodes, entering the blood as a previously unidentified single-phenotype, multiclonal population. Upon reaching the tumor, these transiting cells expanded further and differentiated into effector or exhausted T cells, with combination blockade restricting entry into the exhaustion pathway by favoring co-stimulation. Thus, PD-1 and TIGIT inhibition helps shape the repertoire of tumor-reactive CD8+ T cells in draining lymph nodes and determines their immunological fate in the tumor to enhance therapeutic benefit. Analysis of clinical trial samples suggests a similar mechanism may also occur in patients with cancer.

Targeting fibroblast activation protein with chimeric antigen receptor macrophages

Under the rapid advancement of chimeric antigen receptor T cell (CAR-T) technology, CAR-macrophages (CAR-Ms) are also being developed currently in the pre-clinical stage and have been shown to inhibit tumor growth in several mouse tumor models. Fibroblast activation protein (FAP) is a type II transmembrane serine protease, which is expressed in stromal fibroblasts of over 90 % of common human epithelial cancers and is upregulated in fibrotic diseases of the liver, lung and colon, etc. In this study, we firstly constructed FAP-CAR macrophages to target FAP+ cells through in vitro phagocytosis assays. In subsequent in vivo assays, we discovered that FAP-CAR-ΔZETA bone marrow-derived macrophages (BMDMs) rather than FAP-CAR BMDMs, exhibited a pronounced anti-tumor effect in mouse subcutaneous MC38 colon cancer model. In addition, FAP-CAR and FAP-CAR-ΔZETA BMDMs therapy could effectively improve CCl4-induced liver fibrosis in mice. Collectively CAR-Ms targeting FAP demonstrated great therapeutic potential in cancer and liver fibrosis therapy.

Preclinical model for evaluating human TCRs against chimeric syngeneic tumors

BackgroundThe adoptive cell transfer (ACT) of T cell receptor (TCR)-engineered T cells targeting the HLA-A2-restricted epitope NY-ESO-1157-165 (A2/NY) has yielded important clinical responses against several cancers. A variety of approaches...

Deciphering the cellular landscape and potential targets of nasopharyngeal and oral cancers using single-cell RNA sequencing.

Cellular heterogeneity in nasopharyngeal cancer (NPC) and oral cancer remains unclear. In the current study, using single-cell RNA sequencing techniques, we investigated the cellular landscape in NPC and oral cancers. We identified a diverse range of cell types within the tumor microenvironment (TME) and variations in cell infiltration between NPC and oral cancer. In oral cancer, we observed a predominant infiltration of epithelial cells, fibroblasts, and endothelial cells (ECs), while T cells were the main infiltrating cell population in NPCs. We further classified these infiltrating cells into subclusters. Additionally, we observed complex interactions among cells that led to distinct trajectories. In particular, a unique epithelial subcluster with high expression of major histocompatibility complex class II (MHC-II) molecules was correlated with a favorable outcome and infiltration of CD4+ T cells. In addition, MHC-II+ epithelial cells inhibited mouse tumor growth and promoted T-cell infiltration. Consequently, our findings provide a deep understanding of the TME showing a significant prognostic value and therapeutic potential.

Translational findings support regimen selection for first-in-human study of ubamatamab (MUC16 × CD3 bispecific antibody) in patients with recurrent ovarian cancer.

Ubamatamab, a Mucin 16 (MUC16) × cluster of differentiation 3 (CD3) bispecific antibody that promotes T-cell-mediated cytotoxicity of MUC16-expressing cells, is being investigated for the treatment of ovarian cancer. Intravenous administration of ubamatamab, with or without the anti-programmed cell death-1 inhibitor cemiplimab, is being evaluated in a first-in-human study in patients with recurrent ovarian cancer. Invitro cytotoxicity and cytokine data and projected ubamatamab human pharmacokinetic (PK) profiles scaled with monkey PK parameters enabled starting-dose selection in humans. Mouse tumor regression studies identified ubamatamab effective concentrations. Preclinical and clinical PK, cytokine, safety, and efficacy data from dose escalation were integrated to determine expansion regimens. A starting dose of 0.1 mg was selected, which showed acceptable safety in patients. A step-up dosing approach was used to effectively manage cytokine release syndrome. Mouse tumor regression models suggested an ubamatamab efficacious concentration range of 0.4-50 mg/L, consistent with clinical activity observed at ubamatamab trough concentrations ≥5 mg/L. Integrating preclinical and clinical data determined a target trough concentration range of 5-30 mg/L, which supports evaluation of ubamatamab 250 mg with or without cemiplimab and 800 mg monotherapy once every 3 weeks in expansion cohorts. Preclinical data (cytokine release, tumor regression, monkey PK) had translational value in supporting regimen selection in dose escalation and subsequently in dose expansion after integration with patient data from dose escalation.

METTL3-VISTA axis-based combination immunotherapy for APC truncation colorectal cancer

ObjectiveAlthough immune checkpoint blockade (ICB) therapy represents a bright spot in antitumor immunotherapy, its clinical benefits in colorectal cancer (CRC) are limited. Therefore, a new target for mediating CRC immunosuppression...

GEFT inhibits the GSDM-mediated proptosis signalling pathway, promoting the progression and drug resistance of rhabdomyosarcoma

The metastasis or recurrence of rhabdomyosarcoma (RMS) is the primary cause of tumour-related deaths. Patients with high-risk RMS have poor prognosis with a 5-year overall survival rate of 20–30%. The lack of specific drug-targeted therapy and chemotherapy resistance are the main reasons for treatment failure. Drugs or molecular target inhibitors can induce the pyroptosis of tumour cells or increase their sensitivity to chemotherapy, making pyroptosis an effective strategy for antitumour therapies. Pyroptosis is mediated by gasdermin (GSDM) family members. Here, we found that the expression of NLRP3, caspase-1, caspase-3, GSDMD and GSDME in RMS was remarkably lower than that in skeletal muscle tissues. Nigericin and dactinomycin in RMS cells achieved their regulatory effect on pyroptosis through the NLRP3/caspase-1/GSDMD pathway and caspase-3/GSDME pathway, respectively. Necrosulfonamide reversed the pyroptosis-related changes induced by nigericin, and siGSDME converted the dactinomycin-induced pyroptosis into apoptosis. Additionally, GEFT inhibited the GSDMD and GSDME pyroptosis pathways, thereby promoting the progression and drug resistance of RMS. Mouse xenograft and tumour analysis confirmed that nigericin and dactinomycin can effectively improve the therapeutic effect of RMS by activating the pyroptosis pathway. To the best of our knowledge, this study was the first to focus on pyroptosis in RMS. Overall, our investigation demonstrated that nigericin and dactinomycin play therapeutic roles in tumours by promoting RMS cell pyroptosis. Interference with GEFT and drug combination can exert a great inhibitory effect on tumours.

Centromere protein K enhances the activation of YAP1/TAZ signal cascade to drive the progression of clear cell renal cell carcinoma

Centromere protein K (CENPK) is a newly identified malignancy-related gene that exhibits differential expression in various cancers and plays a crucial role in carcinogenesis. However, it remains uncertain whether CENPK is involved in clear cell renal cell carcinoma (ccRCC). This work aimed to unveil the expression, clinical significance, biological functions, and regulatory mechanisms of CENPK in ccRCC. Through analysis of RNA-seq data obtained from TCGA, a high expression pattern of CENPK was identified in ccRCC, which was found to be associated with pathologic stage, histologic grade, and clinical outcome. The enrichment of CENPK in ccRCC was further verified through the analysis of clinical samples. By conducting cellular functional experiments, we showed an inhibitory effect of CENPK knockdown on the malignant behavior of ccRCC cells. GSEA revealed a close relationship between CENPK and the Hippo–YAP1/TAZ signal cascade. The following experiments demonstrated that the activation of YAP1/TAZ was strongly inhibited by CENPK knockdown, and this change was accompanied by a decrease in the levels of CTGF and CYR61. Blockade of the MST1/2-LATS1/2 axis reversed the suppressive impact of CENPK knockdown on YAP1/TAZ. The tumor-promoting impact observed upon CENPK overexpression was diminished in YAP1 knockout cells. Notably, ccRCC cells with reduced CENPK expression exhibited a diminished capability to form tumors in nude mice. This report highlights the importance of CENPK in ccRCC and sheds new light on the underlying mechanism of this cancer type. Therefore, CENPK has the potential to serve as a viable candidate target for treating ccRCC.

RNA binding protein RBM22 suppresses non-small cell lung cancer tumorigenesis by stabilizing LATS1 mRNA.

Non-small cell lung cancer (NSCLC) is a leading cause of cancer-related mortality worldwide. Despite advancements in diagnostics and therapeutics, the prognosis for NSCLC remains poor, highlighting the urgent need for novel treatment options. RNA binding proteins, particularly RBM22, have emerged as significant contributors to cancer progression by influencing RNA splicing and gene expression. This study investigates the role of RBM22 in NSCLC and its potential as a therapeutic target. We focus on the effects of RBM22 on cell proliferation, invasion, stemness, and its interaction with LATS1 mRNA. RBM22 expression was assessed in samples and cell lines of NSCLC through techniques such as real-time PCR and western blot analysis. To modify RBM22 levels, overexpression and knockdown methods were employed utilizing vectors and siRNAs. We conducted assays for cell proliferation, invasion, and stemness to evaluate the effects of altering RBM22. The interaction between RBM22 and LATS1 mRNA was investigated using RNA immunoprecipitation. In addition, in vivo studies involving subdermal tumor and lung metastasis models in athymic mice were carried out to evaluate how changes in RBM22 influence the tumorigenic and metastatic characteristics of NSCLC. Our analysis revealed a significant underexpression of RBM22 in NSCLC tissues compared to adjacent healthy tissues. Increasing RBM22 expression in NSCLC cell lines led to a marked decrease in cellular proliferation, invasiveness, and stemness, while silencing RBM22 produced opposing effects. Further investigations confirmed that RBM22 directly interacts with LATS1 mRNA, thereby stabilizing and enhancing its expression. In vivo studies validated that elevated RBM22 expression substantially reduced tumor formation and pulmonary metastases, as evidenced by decreased tumor size, mass, and Ki-67 proliferation marker expression, along with a significant reduction in the number of metastatic nodules in the lungs. Our study demonstrates that RBM22 suppresses NSCLC by stabilizing LATS1 mRNA, which in turn reduces tumor growth and metastasis. Consequently, RBM22 emerges as a valuable therapeutic target for NSCLC, offering new strategies for addressing this challenging condition.

Polymeric Multivalent Fc Binding Peptides-Fabricated Clinical Compounding Bispecific Antibody Potentiates Dual Immunotherapy Targeting PD1 and CTLA-4.

Dual Opdivo plus Yervoy immunotherapy, targeting the immune checkpoints PD1 and CTLA-4, is successful in clinical use. However, it is associated with a high incidence of adverse events, and its therapeutic efficacy needs improving. In this study, polymeric multivalent Fc-binding peptides (PLG-Fc-III-4C) are employed to fabricate a bispecific antibody (PD1/CTLA-4 BsAb) to potentiate dual immunotherapy targeting PD1 and CTLA-4. The PD1/CTLA-4 BsAb is prepared by mixing PLG-Fc-III-4C with aPD1 and aCTLA-4 in an aqueous solution for 3 h using the clinically optimal 3:1 proportion of aPD1 to aCTLA-4. PD1/CTLA-4 BsAb significantly inhibits tumors in MC38 colon cancer-bearing mice more effectively than the combination of aPD1 and aCTLA-4, with tumor suppression rates of 96.8% and 77.3%, respectively. It also induces a higher percentage of CD8+ T cells and increases the secretion of effector cytokines while reducing Treg levels in tumors compared to phosphate-buffered saline, indicating significant tumor immunity regulation. Mechanistically, a 6.3-fold increase in PD1/CTLA-4 BsAb accumulation in tumors due to the tumor targeting ability of aPD1, and the PD1/CTLA-4 BsAb significantly reduces the adverse colitis event in healthy mice, compared to aPD1 and aCTLA-4. Thus, these findings provide a novel approach to enhance antitumor therapy using aPD1 and aCTLA-4.

NFE2L2 and SLC25A39 drive cuproptosis resistance through GSH metabolism

Cuproptosis is a recently discovered form of regulated cell death triggered by mitochondrial copper accumulation and proteotoxic stress. Here, we provide the first evidence that glutathione (GSH), a major non-protein thiol in cells, acts as a cuproptosis inhibitor in pancreatic ductal adenocarcinoma (PDAC) cells. Mechanistically, GSH inhibits cuproptosis by chelating copper, contrasting its role in blocking ferroptosis by inhibiting lipid peroxidation. The classical cuproptosis inducer, ES-Cu (elesclomol plus copper), increases the protein stability of the transcription factor NFE2L2 (also known as NRF2), leading to the upregulation of gene expression of glutamate-cysteine ligase modifier subunit (GCLM) and glutamate-cysteine ligase catalytic subunit (GCLC). GCLM and GCLC are rate-limiting enzymes in GSH synthesis, and increased GSH is transported into mitochondria via the solute carrier family 25 member 39 (SLC25A39) transporter. Consequently, genetic inhibition of the NFE2L2-GSH-SLC25A39 pathway enhances cuproptosis-mediated tumor suppression in cell culture and in mouse tumor models. These findings not only reveal distinct mechanisms of GSH in inhibiting cuproptosis and ferroptosis, but also suggest a potential combination strategy to suppress PDAC tumor growth.

Study on the biosafety and targeting efficiency of Escherichia coli outer membrane vesicles in breast tumor.

To seek out the targeting of Escherichia coli outer membrane vesicles (E. coli OMVs) in breast tumor-bearing mice and their biosafety in healthy mice. Ultrafiltration in conjunction with ultracentrifugation was utilized to concentrate E. coli OMVs, and characterize them. Subcutaneous breast tumors were induced in BALB/c mice to serve as an experimental model, and the biodistribution of E. coli OMVs in both tumor-bearing and healthy mice was monitored using an in vivo fluorescence imaging system. Utilizing frozen sections, the infiltration of E. coli OMVs in tumor tissues was appraised at the 24-hour post-injection. Healthy BALB/c mice were randomly divided into control group and vesicles group. Following the intravenous injection of E. coli OMVs, monitoring encompassed variations in body weight, blood routine indices, serum levels of AST, ALT, and BUN, organ indices (heart, liver, spleen, lung, and kidney), along with tissue histopathology over a 14-day period. The spherical E. coli OMVs had a diameter of (155.8 ± 3.1) nm and exhibited the expression of outer membrane proteins OmpA and OmpC. Upon assessment, it was evident that the E. coli OMVs persisted in the tumor tissues even 24h post-injection. An evident decrease in the body weight of the vesicles group, distinct from the control group, was observed on the second day after injection (P < 0.001); in contrast, no considerable differences were noted at subsequent time points (P > 0.05). Following the injection, the vesicles group displayed notable reductions in WBC and PLT as relative to the control group (P < 0.0001) on the initial day, however, there were no noteworthy distinctions as opposed to the control group for other hematological indices; No notable variances in hematological indices between the two groups were observed on the seventh and fourteenth day (P > 0.05). Over the 14 days, no substantial differences were observed in the serum levels of BUN, AST, ALT, and organ indices within the vesicles group as opposed to the control group (P > 0.05). Furthermore, there were no obvious abnormal changes in tissue morphology. 0.5mg/kg of E. coli OMVs can safely and effectively target 4T1 breast tumor in mice.