METTL1-mediated tRNA m7G methylation and translational dysfunction restricts breast cancer tumorigenesis by fueling cell cycle blockade.

BACKGROUND: RNA modifications of transfer RNAs (tRNAs) are critical for tRNA function. Growing evidence has revealed that tRNA modifications are related to various disease processes, including malignant tumors. However, the biological functions of methyltransferase-like 1 (METTL1)-regulated m7G tRNA modifications in breast cancer (BC) remain largely obscure. METHODS: The biological role of METTL1 in BC progression were examined by cellular loss- and gain-of-function tests and xenograft models both in vitro and in vivo. To investigate the change of m7G tRNA modification and mRNA translation efficiency in BC, m7G-methylated tRNA immunoprecipitation sequencing (m7G tRNA MeRIP-seq), Ribosome profiling sequencing (Ribo-seq), and polysome-associated mRNA sequencing were performed. Rescue assays were conducted to decipher the underlying molecular mechanisms. RESULTS: The tRNA m7G methyltransferase complex components METTL1 and WD repeat domain 4 (WDR4) were down-regulated in BC tissues at both the mRNA and protein levels. Functionally, METTL1 inhibited BC cell proliferation, and cell cycle progression, relying on its enzymatic activity. Mechanistically, METTL1 increased m7G levels of 19 tRNAs to modulate the translation of growth arrest and DNA damage 45 alpha (GADD45A) and retinoblastoma protein 1 (RB1) in a codon-dependent manner associated with m7G. Furthermore, in vivo experiments showed that overexpression of METTL1 enhanced the anti-tumor effectiveness of abemaciclib, a cyclin-dependent kinases 4 and 6 (CDK4/6) inhibitor. CONCLUSION: Our study uncovered the crucial tumor-suppressive role of METTL1-mediated tRNA m7G modification in BC by promoting the translation of GADD45A and RB1 mRNAs, selectively blocking the G2/M phase of the cell cycle. These findings also provided a promising strategy for improving the therapeutic benefits of CDK4/6 inhibitors in the treatment of BC patients.

Remodelin delays non-small cell lung cancer progression by inhibiting NAT10 via the EMT pathway.

BACKGROUND: Lung cancer remains the foremost reason of cancer-related mortality, with invasion and metastasis profoundly influencing patient prognosis. N-acetyltransferase 10 (NAT10) catalyzes the exclusive N (4)-acetylcytidine (ac4C) modification in eukaryotic RNA. NAT10 dysregulation is linked to various diseases, yet its role in non-small cell lung cancer (NSCLC) invasion and metastasis remains unclear. Our study delves into the clinical significance and functional aspects of NAT10 in NSCLC. METHODS: We investigated NAT10's clinical relevance using The Cancer Genome Atlas (TCGA) and a group of 98 NSCLC patients. Employing WB, qRT-PCR, and IHC analyses, we assessed NAT10 expression in NSCLC tissues, bronchial epithelial cells (BECs), NSCLC cell lines, and mouse xenografts. Further, knockdown and overexpression techniques (siRNA, shRNA, and plasmid) were employed to evaluate NAT10's effects. A series of assays were carried out, including CCK-8, colony formation, wound healing, and transwell assays, to elucidate NAT10's role in proliferation, invasion, and metastasis. Additionally, we utilized lung cancer patient-derived 3D organoids, mouse xenograft models, and Remodelin (NAT10 inhibitor) to corroborate these findings. RESULTS: Our investigations revealed high NAT10 expression in NSCLC tissues, cell lines and mouse xenograft models. High NAT10 level correlated with advanced T stage, lymph node metastasis and poor overall survive. NAT10 knockdown curtailed proliferation, invasion, and migration, whereas NAT10 overexpression yielded contrary effects. Furthermore, diminished NAT10 levels correlated with increased E-cadherin level whereas decreased N-cadherin and vimentin expressions, while heightened NAT10 expression displayed contrasting results. Notably, Remodelin efficiently attenuated NSCLC proliferation, invasion, and migration by inhibiting NAT10 through the epithelial-mesenchymal transition (EMT) pathway. CONCLUSIONS: Our data underscore NAT10 as a potential therapeutic target for NSCLC, presenting avenues for targeted intervention against lung cancer through NAT10 inhibition.

UCHL3 induces radiation resistance and acquisition of mesenchymal phenotypes by deubiquitinating POLD4 in glioma stem cells.

BACKGROUND: The high degree of intratumoral genomic heterogeneity is a major obstacle for glioblastoma (GBM) tumors, one of the most lethal human malignancies, and is thought to influence conventional therapeutic outcomes negatively. The proneural-to-mesenchymal transition (PMT) of glioma stem cells (GSCs) confers resistance to radiation therapy in glioblastoma patients. POLD4 is associated with cancer progression, while the mechanisms underlying PMT and tumor radiation resistance have remained elusive. METHOD: Expression and prognosis of the POLD family were analyzed in TCGA, the Chinese Glioma Genome Atlas (CGGA) and GEO datasets. Tumorsphere formation and in vitro limiting dilution assay were performed to investigate the effect of UCHL3-POLD4 on GSC self-renewal. Apoptosis, TUNEL, cell cycle phase distribution, modification of the Single Cell Gel Electrophoresis (Comet), γ-H2AX immunofluorescence, and colony formation assays were conducted to evaluate the influence of UCHL3-POLD4 on GSC in ionizing radiation. Coimmunoprecipitation and GST pull-down assays were performed to identify POLD4 protein interactors. In vivo, intracranial xenograft mouse models were used to investigate the molecular effect of UCHL3, POLD4 or TCID on GCS. RESULT: We determined that POLD4 was considerably upregulated in MES-GSCs and was associated with a meagre prognosis. Ubiquitin carboxyl terminal hydrolase L3 (UCHL3), a DUB enzyme in the UCH protease family, is a bona fide deubiquitinase of POLD4 in GSCs. UCHL3 interacted with, depolyubiquitinated, and stabilized POLD4. Both in vitro and in vivo assays indicated that targeted depletion of the UCHL3-POLD4 axis reduced GSC self-renewal and tumorigenic capacity and resistance to IR treatment by impairing homologous recombination (HR) and nonhomologous end joining (NHEJ). Additionally, we proved that the UCHL3 inhibitor TCID induced POLD4 degradation and can significantly enhance the therapeutic effect of IR in a gsc-derived in situ xenograft model. CONCLUSION: These findings reveal a new signaling axis for GSC PMT regulation and highlight UCHL3-POLD4 as a potential therapeutic target in GBM. TCID, targeted for reducing the deubiquitinase activity of UCHL3, exhibited significant synergy against MES GSCs in combination with radiation.

YY1 mediated DCUN1D5 transcriptional activation promotes triple-negative breast cancer progression by targeting FN1/PI3K/AKT pathway.

Triple-negative breast cancer (TNBC) is more aggressive and has a higher metastasis rate compared with other subtypes of breast cancer. Due to the lack of drug-targetable receptors, chemotherapy is now the only available systemic treatment for TNBC. However, some patients might still develop drug resistance and have poor prognosis. Therefore, novel molecular biomarkers and new treatment targets are urgently needed for patients with TNBC. To provide molecular insights into TNBC progression, we investigated the function and the underlying mechanism of Defective in cullin neddylation 1 domain containing 5 (DCUN1D5) in the regulation of TNBC. By TCGA dataset and surgical specimens with immunohistochemical (IHC) staining method, DCUN1D5 was identified to be significantly upregulated in TNBC tumor tissues and negatively associated with prognosis. A series of in vitro and in vivo experiments were performed to confirm the oncogenic role of DCUN1D5 in TNBC. Overexpression of FN1 or PI3K/AKT activator IGF-1 could restore the proliferative and invasive ability induced by DCUN1D5 knockdown and DCUN1D5 could act as a novel transcriptional target of transcription factor Yin Yang 1 (YY1). In conclusion, YY1-enhanced DCUN1D5 expression could promote TNBC progression by FN1/PI3K/AKT pathway and DCUN1D5 might be a potential prognostic biomarker and therapeutic target for TNBC treatment.

Activation of AMPK inhibits cervical cancer growth by hyperacetylation of H3K9 through PCAF.

BACKGROUND: Dysregulation in histone acetylation, a significant epigenetic alteration closely associated with major pathologies including cancer, promotes tumorigenesis, inactivating tumor-suppressor genes and activating oncogenic pathways. AMP-activated protein kinase (AMPK) is a cellular energy sensor that regulates a multitude of biological processes. Although a number of studies have identified the mechanisms by which AMPK regulates cancer growth, the underlying epigenetic mechanisms remain unknown. METHODS: The impact of metformin, an AMPK activator, on cervical cancer was evaluated through assessments of cell viability, tumor xenograft model, pan-acetylation analysis, and the role of the AMPK-PCAF-H3K9ac signaling pathway. Using label-free quantitative acetylproteomics and chromatin immunoprecipitation-sequencing (ChIP) technology, the activation of AMPK-induced H3K9 acetylation was further investigated. RESULTS: In this study, we found that metformin, acting as an AMPK agonist, activates AMPK, thereby inhibiting the proliferation of cervical cancer both in vitro and in vivo. Mechanistically, AMPK activation induces H3K9 acetylation at epigenetic level, leading to chromatin remodeling in cervical cancer. This also enhances the binding of H3K9ac to the promoter regions of multiple tumor suppressor genes, thereby promoting their transcriptional activation. Furthermore, the absence of PCAF renders AMPK activation incapable of inducing H3K9 acetylation. CONCLUSIONS: In conclusion, our findings demonstrate that AMPK mediates the inhibition of cervical cancer growth through PCAF-dependent H3K9 acetylation. This discovery not only facilitates the clinical application of metformin but also underscores the essential role of PCAF in AMPK activation-induced H3K9 hyperacetylation.

IFI16 promotes the progression of clear cell renal cell carcinoma through the IL6/PI3K/AKT axis.

BACKGROUND: Clear cell renal cell carcinoma (ccRCC) is a common disease in the urinary system, with a high incidence and poor prognosis in advanced stages. Although γ-interferon-inducible protein 16 (IFI16) has been reported to play a role in various tumors, its involvement in ccRCC remains poorly documented, and the molecular mechanisms are not yet clear. METHODS: We conducted bioinformatics analysis to study the expression of IFI16 in ccRCC using public databases. Additionally, we analyzed and validated clinical specimens that we collected. Subsequently, we explored the impact of IFI16 on ccRCC cell proliferation, migration, and invasion through in vitro and in vivo experiments. Furthermore, we predicted downstream molecules and pathways using transcriptome analysis and confirmed them through follow-up experimental validation. RESULTS: IFI16 was significantly upregulated in ccRCC tissue and correlated with poor patient prognosis. In vitro, IFI16 promoted ccRCC cell proliferation, migration, and invasion, while in vivo, it facilitated subcutaneous tumor growth and the formation of lung metastatic foci. Knocking down IFI16 suppressed its oncogenic function. At the molecular level, IFI16 promoted the transcription and translation of IL6, subsequently activating the PI3K/AKT signaling pathway and inducing epithelial-mesenchymal transition (EMT). CONCLUSION: IFI16 induced EMT through the IL6/PI3K/AKT axis, promoting the progression of ccRCC.

Knockdown of PIK3R6 impedes the onset and advancement of clear cell renal cell carcinoma.

In this research, we investigated the role of PIK3R6, a regulatory subunit of PI3Kγ, known for its tumor-promoting properties, in clear cell renal cell carcinoma (CCRCC). Utilizing the UALCAN website, we found PIK3R6 upregulated in CCRCC, correlating with lower survival rates. We compared PIK3R6 expression in CCRCC tumor tissues and adjacent normal tissues using immunohistochemistry. Post RNA interference-induced knockdown of PIK3R6 in 786-O and ACHN cell lines, we performed CCK-8, colony formation, Edu staining, flow cytometry, wound healing, and transwell assays. Results showed that PIK3R6 silencing reduced cell proliferation, migration, and invasion, and induced G0/G1 phase arrest and apoptosis. Molecular analysis revealed decreased CDK4, Cyclin D1, N-cadherin, Vimentin, Bcl-2, p-PI3K and p-AKT, with increased cleaved caspase-3, Bax, and E-cadherin levels in CCRCC cells. Moreover, inhibiting PIK3R6 hindered tumor growth. These findings suggest a significant role for PIK3R6 in CCRCC cell proliferation and metastasis, presenting it as a potential therapeutic target.

Hyaluronic Acid-Bilirubin Nanoparticles as a Tumor Microenvironment Reactive Oxygen Species-Responsive Nanomedicine for Targeted Cancer Therapy.

Introduction: The tumor microenvironment (TME) has attracted considerable attention as a potential therapeutic target for cancer. High levels of reactive oxygen species (ROS) in the TME may act as a stimulus for drug release. In this study, we have developed ROS-responsive hyaluronic acid-bilirubin nanoparticles (HABN) loaded with doxorubicin (DOX@HABN) for the specific delivery and release of DOX in tumor tissue. The hyaluronic acid shell of the nanoparticles acts as an active targeting ligand that can specifically bind to CD44-overexpressing tumors. The bilirubin core has intrinsic anti-cancer activity and ROS-responsive solubility change properties. Methods & Results: DOX@HABN showed the HA shell-mediated targeting ability, ROS-responsive disruption leading to ROS-mediated drug release, and synergistic anti-cancer activity against ROS-overproducing CD44-overexpressing HeLa cells. Additionally, intravenously administered HABN-Cy5.5 showed remarkable tumor-targeting ability in HeLa tumor-bearing mice with limited distribution in major organs. Finally, intravenous injection of DOX@HABN into HeLa tumor-bearing mice showed synergistic anti-tumor efficacy without noticeable side effects. Conclusion: These findings suggest that DOX@HABN has significant potential as a cancer-targeting and TME ROS-responsive nanomedicine for targeted cancer treatment.

PD-L1 regulates tumor proliferation and T-cell function in NF2-associated meningiomas.

INTRODUCTION: Programmed death-ligand 1 (PD-L1) expression is an immune evasion mechanism that has been demonstrated in many tumors and is commonly associated with a poor prognosis. Over the years, anti-PD-L1 agents have gained attention as novel anticancer therapeutics that induce durable tumor regression in numerous malignancies. They may be a new treatment choice for neurofibromatosis type 2 (NF2) patients. AIMS: The aims of this study were to detect the expression of PD-L1 in NF2-associated meningiomas, explore the effect of PD-L1 downregulation on tumor cell characteristics and T-cell functions, and investigate the possible pathways that regulate PD-L1 expression to further dissect the possible mechanism of immune suppression in NF2 tumors and to provide new treatment options for NF2 patients. RESULTS: PD-L1 is heterogeneously expressed in NF2-associated meningiomas. After PD-L1 knockdown in NF2-associated meningioma cells, tumor cell proliferation was significantly inhibited, and the apoptosis rate was elevated. When T cells were cocultured with siPD-L1-transfected NF2-associated meningioma cells, the expression of CD69 on both CD4+ and CD8+ T cells was partly reversed, and the capacity of CD8+ T cells to kill siPD-L1-transfected tumor cells was partly restored. Results also showed that the PI3K-AKT-mTOR pathway regulates PD-L1 expression, and the mTOR inhibitor rapamycin rapidly and persistently suppresses PD-L1 expression. In vivo experimental results suggested that anti-PD-L1 antibody may have a synergetic effect with the mTOR inhibitor in reducing tumor cell proliferation and that reduced PD-L1 expression could contribute to antitumor efficacy. CONCLUSIONS: Targeting PD-L1 could be helpful for restoring the function of tumor-infiltrating lymphocytes and inducing apoptosis to inhibit tumor proliferation in NF2-associated meningiomas. Dissecting the mechanisms of the PD-L1-driven tumorigenesis of NF2-associated meningioma will help to improve our understanding of the mechanisms underlying tumor progression and could facilitate further refinement of current therapies to improve the treatment of NF2 patients.

PPIA dictates NRF2 stability to promote lung cancer progression.

Nuclear factor erythroid 2-related factor 2 (NRF2) hyperactivation has been established as an oncogenic driver in a variety of human cancers, including non-small cell lung cancer (NSCLC). However, despite massive efforts, no specific therapy is currently available to target NRF2 hyperactivation. Here, we identify peptidylprolyl isomerase A (PPIA) is required for NRF2 protein stability. Ablation of PPIA promotes NRF2 protein degradation and blocks NRF2-driven growth in NSCLC cells. Mechanistically, PPIA physically binds to NRF2 and blocks the access of ubiquitin/Kelch Like ECH Associated Protein 1 (KEAP1) to NRF2, thus preventing ubiquitin-mediated degradation. Our X-ray co-crystal structure reveals that PPIA directly interacts with a NRF2 interdomain linker via a trans-proline 174-harboring hydrophobic sequence. We further demonstrate that an FDA-approved drug, cyclosporin A (CsA), impairs the interaction of NRF2 with PPIA, inducing NRF2 ubiquitination and degradation. Interestingly, CsA interrupts glutamine metabolism mediated by the NRF2/KLF5/SLC1A5 pathway, consequently suppressing the growth of NRF2-hyperactivated NSCLC cells. CsA and a glutaminase inhibitor combination therapy significantly retard tumor progression in NSCLC patient-derived xenograft (PDX) models with NRF2 hyperactivation. Our study demonstrates that targeting NRF2 protein stability is an actionable therapeutic approach to treat NRF2-hyperactivated NSCLC.

The m6A reader HNRNPC promotes glioma progression by enhancing the stability of IRAK1 mRNA through the MAPK pathway.

Glioma is the most common and aggressive type of primary malignant brain tumor. The N6-methyladenosine (m6A) modification widely exists in eukaryotic cells and plays an important role in the occurrence and development of human tumors. However, the function and mechanism of heterogeneous nuclear ribonucleoprotein C (HNRNPC), an RNA-binding protein and m6A reader in gliomas remains to be comprehensively and extensively explored. Herein, we found that HNRNPC mRNA and protein overexpression were associated with a poor prognosis for patients with gliomas, based on the data from TCGA, the CGGA, and the TMAs. Biologically, HNRNPC knockdown markedly repressed malignant phenotypes of glioma in vitro and in vivo, whereas ectopic HNRNPC expression had the opposite effect. Integrative RNA sequencing and MeRIP sequencing analyses identified interleukin-1 receptor-associated kinase 1 (IRAK1) as a downstream target of HNRNPC. The glioma public datasets and tissue microarrays (TMAs) data indicated that IRAK1 overexpression was associated with poor prognosis, and IRAK1 knockdown significantly repressed malignant biological behavior in vitro. Mechanistically, HNRNPC maintains the mRNA stability of IRAK1 in an m6A-dependent manner, resulting in activation of the mitogen-activated protein kinase (MAPK) signaling pathway, which was necessary for the malignant behavior of glioma. Our findings demonstrate the HNRNPC-IRAK1-MAPK axis as a crucial carcinogenic factor for glioma and the novel underlying mechanism of IRAK1 upregulation, which provides a rationale for therapeutically targeting epitranscriptomic modulators in glioma.

MNT inhibits lung adenocarcinoma ferroptosis and chemosensitivity by suppressing SAT1.

Ferroptosis, a type of iron-dependent non-apoptotic cell death, plays a vital role in both tumor proliferation and resistance to chemotherapy. Here, our study demonstrates that MAX's Next Tango (MNT), by involving itself in the spermidine/spermine N1-acetyltransferase 1 (SAT1)-related ferroptosis pathway, promotes the proliferation of lung adenocarcinoma (LUAD) cells and diminishes their sensitivity to chemotherapy. Initially, an RNA-sequence screen of LUAD cells treated with ferroptosis inducers (FINs) reveals a significant increase in MNT expression, suggesting a potential link between MNT and ferroptosis. Overexpression of MNT in LUAD cells hinders changes associated with ferroptosis. Moreover, the upregulation of MNT promotes cell proliferation and suppresses chemotherapy sensitivity, while the knockdown of MNT has the opposite effect. Through the intersection of ChIP-Seq and ferroptosis-associated gene sets, and validation by qPCR and western blot, SAT1 is identified as a potential target of MNT. Subsequently, we demonstrate that MNT binds to the promoter sequence of SAT1 and suppresses its transcription by ChIP-qPCR and dual luciferase assays. Restoration of SAT1 levels antagonizes the efficacy of MNT to inhibit ferroptosis and chemosensitivity and promote cell growth in vitro as well as in vivo. In the clinical context, MNT expression is elevated in LUAD and is inversely connected with SAT1 expression. High MNT expression is also associated with poor patient survival. Our research reveals that MNT inhibits ferroptosis, and impairing chemotherapy effectiveness of LUAD.

NEDD4L mediates ITGB4 ubiquitination and degradation to suppress esophageal carcinoma progression.

The ubiquitination-mediated protein degradation exerts a vital role in the progression of multiple tumors. NEDD4L, which belongs to the E3 ubiquitin ligase NEDD4 family, is related to tumor genesis, metastasis and drug resistance. However, the anti-tumor role of NEDD4L in esophageal carcinoma, and the potential specific recognition substrate remain unclear. Based on public esophageal carcinoma database and clinical sample data, it was discovered in this study that the expression of NEDD4L in esophageal carcinoma was apparently lower than that in atypical hyperplastic esophageal tissue and esophageal squamous epithelium. Besides, patients with high expression of NEDD4L in esophageal carcinoma tissue had longer progression-free survival than those with low expression. Experiments in vivo and in vitro also verified that NEDD4L suppressed the growth and metastasis of esophageal carcinoma. Based on co-immunoprecipitation and proteome analysis, the NEDD4L ubiquitination-degraded protein ITGB4 was obtained. In terms of the mechanism, the HECT domain of NEDD4L specifically bound to the Galx-ß domain of ITGB4, which modified the K915 site of ITGB4 in an ubiquitination manner, and promoted the ubiquitination degradation of ITGB4, thus suppressing the malignant phenotype of esophageal carcinoma.

Homotypic cell membrane-camouflaged biomimetic PLGA nanoparticle loading triptolide for the treatment of hepatocellular carcinoma.

Hepatocellular carcinoma (HCC) is the fourth leading cause of cancer-associated death worldwide. Beside early detection, early diagnosis, and early surgery, it is urgent to try new strategies for the treatment of HCC. Triptolide (TPL) has been employed to treat HCC. However, its clinical applications were restricted by the narrow therapeutic window, severe toxicity, and poor water-solubility. In this study, we developed cancer cell membrane-camouflaged biomimetic PLGA nanoparticles loading TPL (TPL@mPLGA) with the homologous targeting property for the treatment of HCC. The TPL@mPLGA was successfully prepared with particle size of 195.5 ± 7.5 nm and zeta potential at -21.5 ± 0.2 mV with good stability. The drug loading (DL) of TPL@mPLGA was 2.94%. After Huh-7 cell membrane coating, the natural Huh-7 cell membrane proteins were found to be retained on TPL@mPLGA, thus endowing the TPL@mPLGA with enhanced accumulation at tumor site, and better anti-tumor activity in vitro and in vivo when compared with TPL or TPL@PLGA. The TPL@mPLGA showed enhanced anti-tumor effects and reduced toxicity of TPL, which could be adopted for the treatment of HCC.

Inhibition of glycolysis enhances the efficacy of immunotherapy via PDK-mediated upregulation of PD-L1.

BACKGROUND: Immunotherapy for gastric cancer remains a challenge due to its limited efficacy. Metabolic reprogramming toward glycolysis has emerged as a promising avenue for enhancing the sensitivity of tumors to immunotherapy. Pyruvate dehydrogenase kinases (PDKs) play pivotal roles in regulating glycolysis. The importance of PDKs in the context of gastric cancer immunotherapy and their potential as therapeutic targets have not been fully explored. METHODS: PDK and PD-L1 expression was analyzed using data from the GSE66229 and The Cancer Genome Atlas (TCGA) cohorts. Additionally, the Immune Checkpoint Blockade Therapy Atlas (ICBatlas) database was utilized to assess PDK expression in an immune checkpoint blockade (ICB) therapy group. Subsequently, the upregulation of PD-L1 and the enhancement of anticancer effects achieved by targeting PDK were validated through in vivo and in vitro assays. The impact of PDK on histone acetylation was investigated using ChIP‒qPCR to detect changes in histone acetylation levels. RESULTS: Our analysis revealed a notable negative correlation between PD-L1 and PDK expression. Downregulation of PDK led to a significant increase in PD-L1 expression. PDK inhibition increased histone acetylation levels by promoting acetyl-CoA generation. The augmentation of acetyl-CoA production and concurrent inhibition of histone deacetylation were found to upregulate PD-L1 expression in gastric cancer cells. Additionally, we observed a significant increase in the anticancer effect of PD-L1 antibodies following treatment with a PDK inhibitor. CONCLUSIONS: Downregulation of PDK in gastric cancer cells leads to an increase in PD-L1 expression levels, thus potentially improving the efficacy of PD-L1 immune checkpoint blockade therapy.

Butyrate inhibits the malignant biological behaviors of breast cancer cells by facilitating cuproptosis-associated gene expression.

BACKGROUND: Butyrate is a common short-chain fatty acids (SCFA), and it has been demonstrated to regulate the development of breast cancer (BC), while the underlying mechanism is still unreported. METHODS: Gas chromatography was used to measure the amounts of SCFA (acetate, propionate, and butyrate) in the feces. Cell viability was measured by the CCK-8 assay. The wound healing assay demonstrated cell migration, and the transwell assay demonstrated cell invasion. The levels of protein and gene were determined by western blot assay and RT-qPCR assay, respectively. RESULTS: The levels of SCFA were lower in the faecal samples from BC patients compared to control samples. In cellular experiments, butyrate significantly suppressed the cell viability, migration and invasion of T47D in a dose-dependent manner. In animal experiments, butyrate effectively impeded the growth of BC tumors. Toll like receptor 4 (TLR4) was highly expressed in the tumors from BC patients. Butyrate inhibited the expression of TLR4. In addition, butyrate promoted the expression of cuproptosis-related genes including PDXK (pyridoxal kinase) and SLC25A28 (solute carrier family 25 member 28), which was lowly expressed in BC tumors. Importantly, overexpression of TLR4 can reverses the promotion of butyrate to PDXK and SLC25A28 expression and the prevention of butyrate to the malignant biological behaviors of T47D cells. CONCLUSION: In summary, butyrate inhibits the development of BC by facilitating the expression of PDXK and SLC25A28 through inhibition of TLR4. Our investigation first identified a connection among butyrate, TLR4 and cuproptosis-related genes in BC progression. These findings may provide novel target for the treatment of BC.

Self-Amplified pH/ROS Dual-Responsive Co-Delivery Nano-System with Chemo-Photodynamic Combination Therapy in Hepatic Carcinoma Treatment.

Background: Chemo-photodynamic combination therapy has demonstrated significant potential in the treatment of cancer. Triptolide (TPL), a naturally derived anticancer agent, when combined with the photosensitizer Chlorin e6 (Ce6), has shown to provide enhanced anti-tumor benefits. However, the development of stimuli-responsive nanovehicles for the co-delivery of TPL and Ce6 could further enhance the efficacy of this combination therapy. Methods: In this study, we synthesized a pH/ROS dual-responsive mPEG-TK-PBAE copolymer, which contains a pH-sensitive PBAE moiety and a ROS-sensitive thioketal (TK) linkage. Through a self-assembly process, TPL and Ce6 were successfully co-loaded into mPEG-TK-PBAE nanoparticles, hereafter referred to as TPL/Ce6 NPs. We evaluated the pH- and ROS-sensitive drug release and particle size changes. Furthermore, we investigated both the in vitro suppression of cellular proliferation and induction of apoptosis in HepG2 cells, as well as the in vivo anti-tumor efficacy of TPL/Ce6 NPs in H22 xenograft nude mice. Results: The mPEG-TK-PBAE copolymer was synthesized through a one-pot Michael-addition reaction and successfully co-encapsulated both TPL and Ce6 by self-assembly. Upon exposure to acid pH values and high ROS levels, the payloads in TPL/Ce6 NPs were rapidly released. Notably, the abundant ROS generated by the released Ce6 under laser irradiation further accelerated the degradation of the nanosystem, thereby amplifying the tumor microenvironment-responsive drug release and enhancing anticancer efficacy. Consequently, TPL/Ce6 NPs significantly increased PDT-induced oxidative stress and augmented TPL-induced apoptosis in HepG2 cells, leading to synergistic anticancer effects in vitro. Moreover, administering TPL/Ce6 NPs (containing 0.3 mg/kg of TPL and 4 mg/kg of Ce6) seven times, accompanied by 650 nm laser irradiation, efficiently inhibited tumor growth in H22 tumor-bearing mice, while exhibiting lower systemic toxicity. Conclusion: Overall, we have developed a tumor microenvironment-responsive nanosystem for the co-delivery of TPL and Ce6, demonstrating amplified synergistic effects of chemo-photodynamic therapy (chemo-PDT) for hepatocellular carcinoma (HCC) treatment.

F. Nucleatum enhances oral squamous cell carcinoma proliferation via E-cadherin/ß-Catenin pathway.

BACKGROUND: Fusobacterium nucleatum (F. nucleatum) is a microbial risk factor whose presence increases the risk of oral squamous cell carcinoma (OSCC) progression. However, whether it can promote the proliferation of OSCC cells remains unknown. METHODS: In this study, we investigated F. nucleatum effect on OSCC cell proliferation using in vitro and in vivo experiments. RESULTS: Our results showed that F. nucleatum promoted OSCC cell proliferation, doubling the cell count after 72 h (CCK-8 assay). Cell cycle analysis revealed G2/M phase arrest. F. nucleatum interaction with CDH1 triggered phosphorylation, upregulating downstream protein ß-catenin and activating cyclinD1 and Myc. Notably, F. nucleatum did not affect noncancerous cells, unrelated to CDH1 expression levels in CAL27 cells. Overexpression of phosphorylated CDH1 in 293T cells did not upregulate ß-catenin and cycle-related genes. In vivo BALB/c nude experiments showed increased tumor volume and Ki-67 proliferation index after F. nucleatum intervention. CONCLUSION: Our study suggests that F. nucleatum promotes OSCC cell proliferation through the CDH1/ß-catenin pathway, advancing our understanding of its role in OSCC progression and highlighting its potential as a therapeutic target.

Early therapy evaluation of intra-arterial trastuzumab injection in a human breast cancer xenograft model using multiparametric MR imaging.

PURPOSE: To investigate the treatment efficacy of intra-arterial (IA) trastuzumab treatment using multiparametric magnetic resonance imaging (MRI) in a human breast cancer xenograft model. MATERIALS AND METHODS: Human breast cancer cells (BT474) were stereotaxically injected into the brains of nude mice to obtain a xenograft model. The mice were divided into four groups and subjected to different treatments (IA treatment [IA-T], intravenous treatment [IV-T], IA saline injection [IA-S], and the sham control group). MRI was performed before and at 7 and 14 d after treatment to assess the efficacy of the treatment. The tumor volume, apparent diffusion coefficient (ADC), and dynamic contrast-enhanced (DCE) MRI parameters (Ktrans, Kep, Ve, and Vp) were measured. RESULTS: Tumor volumes in the IA-T group at 14 d after treatment were significantly lower than those in the IV-T group (13.1 mm3 [interquartile range 8.48-16.05] vs. 25.69 mm3 [IQR 20.39-30.29], p = 0.005), control group (IA-S, 33.83 mm3 [IQR 32.00-36.30], p<0.01), and sham control (39.71 mm3 [IQR 26.60-48.26], p <0.001). The ADC value in the IA-T group was higher than that in the control groups (IA-T, 7.62 [IQR 7.23-8.20] vs. IA-S, 6.77 [IQR 6.48-6.87], p = 0.044 and vs. sham control, 6.89 [IQR 4.93-7.48], p = 0.004). Ktrans was significantly decreased following the treatment compared to that in the control groups (p = 0.002 and p<0.001 for vs. IA-S and sham control, respectively). Tumor growth was decreased in the IV-T group compared to that in the sham control group (25.69 mm3 [IQR 20.39-30.29] vs. 39.71 mm3 [IQR 26.60-48.26], p = 0.27); there was no significant change in the MRI parameters. CONCLUSION: IA treatment with trastuzumab potentially affects the early response to treatment, including decreased tumor growth and decrease of Ktrans, in a preclinical brain tumor model.

MiR-122-5p regulates erastin-induced ferroptosis via CS in nasopharyngeal carcinoma.

Nasopharyngeal carcinoma (NPC) is a tumor that occurs in the nasopharynx. Although advances in detection and treatment have improved the prognosis of NPC the treatment of advanced NPC remains challenging. Here, we explored the effect of microRNA (miR)-122-5p on erastin-induced ferroptosis in NPC cells and the role of ferroptosis in the development of NPC. The effect of miR-122-5p silencing and overexpression and the effect of citrate synthase on erastin-induced lipid peroxidation in NPC cells was analyzed by measuring the amounts of malondialdehyde, Fe2+, glutathione, and reactive oxygen species and the morphological alterations of mitochondria. The malignant biological behavior of NPC cells was examined by cell counting kit-8, EDU, colony formation, Transwell, and wound healing assays. The effects of miR-122-5p on cell proliferation and migration associated with ferroptosis were examined in vivo in a mouse model of NPC generated by subcutaneous injection of NPC cells. We found that erastin induced ferroptosis in NPC cells. miR-122-5p overexpression inhibited CS, thereby promoting erastin-induced ferroptosis in NPC cells and decreasing NPC cell proliferation, migration, and invasion.