Breast Cancer Tumor Tissues Research Articles

Investigation of CST7 and hsa-miR-4793-5p gene expression in breast cancer

Breast cancer (BC) presents as a worldwide challenge, known as the most frequently diagnosed cancer in women. In 2022, BC was diagnosed in 2.3 million women with 670,000 deaths globally. In this research, our objective was to examine the CST7 and has-miR-4793-5p gene expression in BC tumor tissues and adjacent normal tissues.Using GSE57897 gene expression data from 422 BC samples and 31 breast samples from healthy controls which was based on the Platform GPL18722 (spotted oligonucleotide Homo sapiens microRNA (miRNA) array) in the Gene Expression Omnibus (GEO) and compare with miRNAs with a conserved target location on CST7 mRNA were found using databases. The study population included 60 fresh BC tissue samples and adjacent normal tissues as control. The Quantitative Real-Time PCR was used to evaluate the expression levels of CST7 and has-miR-4793-5p in the breast tissues.The present study, found that CST7 and hsa-miR-4793-5p were significantly increased in tumoral tissues in compare to normal tissues. Further analysis revealed a remarkable association between CST7 and hsa-miR-4793-5p gene expression alteration. ROC curve analysis demonstrated high accuracy for CST7 expression in BC tumors. Comparison of gene expression between different stages and patient family history showed significant findings. Due to the high sensitivity and specificity of the expression changes of these two genes, they are suitable candidates for further investigations to be considered as part of a diagnosis and prognosis panel.

The heterogeneity of breast cancer metastasis: a bioinformatics analysis utilizing single-cell RNA sequencing data.

Breast cancer is a common malignancy in women, and its metastasis is a leading cause of cancer-related deaths. Single-cell RNA sequencing (scRNA-seq) can distinguish the molecular characteristics of metastasis and identify predictor genes for patient prognosis. This article explores gene expression in primary breast cancer tumor tissue against metastatic cells in the lymph node and liver using scRNA-seq. Breast cancer scRNA-seq data from the Gene Expression Omnibus were used. The data were processed using R and the Seurat package. The cells were clustered and identified using Metascape. InferCNV is used to analyze the variation in copy number. Differential expression analysis was conducted for the cancer cells using Seurat and was enriched using Metascape. We identified 18 distinct cell clusters, 6 of which were epithelial. CNV analysis identified significant alterations with duplication of chromosomes 1, 8, and 19. Differential gene analysis resulted in 17 upregulated and 171 downregulated genes for the primary tumor in the primary tumor vs. liver metastasis comparison and 43 upregulated and 4 downregulated genes in the primary tumor in the primary tumor vs lymph node metastasis comparison. Several enriched terms include Ribosome biogenesis, NTP synthesis, Epithelial dedifferentiation, Autophagy, and genes associated with epithelial-to-mesenchymal transitions. No single gene or pathway can clearly explain the mechanisms behind tumor metastasis. Several mechanisms contribute to lymph node and liver metastasis, such as the loss of differentiation, epithelial-to-mesenchymal transition, and autophagy. These findings necessitate further study of metastatic tissue for effective drug development.

Hypoxic stabilization of RIPOR3 mRNA via METTL3-mediated m6A methylation drives breast cancer progression and metastasis.

Dysregulated N6-methyladenosine (m6A) modification has been associated with breast cancer pathogenesis. Hypoxia which characterizes solid tumors is known to reprogram the m6A epitranscriptome, but the underlying mechanisms of how this process contributes to breast cancer progression remain poorly understood. Through integrative analyses of m6A-RIP sequencing and RNA sequencing databases, we reveal a cluster of mRNAs with upregulated m6A methylation and expression under hypoxia, that are enriched by many oncogenic pathways, including PI3K-Akt signaling. Furthermore, we identify the mRNA, RIPOR3, as a target of METTL3-mediated m6A methylation in response to hypoxia. We find that m6A methylation stabilizes RIPOR3, increasing its protein expression in a METTL3 catalytic activity-dependent manner, and consequently driving breast tumor growth and metastasis. RIPOR3 is found to be overexpressed in breast cancer cell lines and tumor tissues from breast cancer patients, in whom elevated RIPOR3 is associated with a worse prognosis. Mechanistically, we show that RIPOR3 interacts with EGFR and is essential for the PI3K-Akt pathway activation. In conclusion, we identify RIPOR3 as a hypoxia-stabilized oncogenic driver via METTL3-mediated m6A methylation, thus provide a potential therapeutic target for breast cancer.

Investigation of the α9-nicotinic receptor single nucleotide polymorphisms induced oncogenic properties and molecular mechanisms in breast cancer.

α9-nAChR, a subtype of nicotinic acetylcholine receptor, is significantly overexpressed in female breast cancer tumor tissues compared to normal tissues. Previous studies have proposed that specific single nucleotide polymorphisms (SNPs) in the CHRNA9 (α9-nAChR) gene are associated with an increased risk of breast cancer in interaction with smoking. The study conducted a breast cancer risk assessment of the α9-nAChR SNP rs10009228 (NM_017581.4:c.1325A > G) in the Taiwanese female population, including 308 breast cancer patients and 198 healthy controls revealed that individuals with the heterozygous A/G or A/A wild genotype have an increased susceptibility to developing breast cancer in the presence of smoking compared to carriers of the G/G variant genotype. Our investigation confirmed the presence of this missense variation, resulting in an alteration of the amino acid sequence from asparagine (N442) to serine (S442) to facilitate phosphorylation within the α9-nAchR protein. Additionally, overexpression of N442 (A/A) in breast cancer cells significantly enhanced cell survival, migration, and cancer stemness compared to S442 (G/G). Four-line triple-negative breast cancer patient-derived xenograft (TNBC-PDX) models with distinct α9-nAChR rs10009228 SNP genotypes (A/A, A/G, G/G) further demonstrated that chronic nicotine exposure accelerated tumor growth through sustained activation of the α9-nAChR downstream oncogenic AKT/ERK/STAT3 pathway, particularly in individuals with the A/G or A/A genotype. Collectively, our study established the links between genetic variations in α9-nAChR and smoking exposure in promoting breast tumor development. This emphasizes the need to consider gene-environment interactions carefully while developing effective breast cancer prevention and treatment strategies.

ThP1.10 - Expression Pattern of Arginase In Tumour Tissue In Male Breast Cancer

Abstract Aim To study the expression pattern of arginase in tumor tissue of male breast cancer (MBC) by immunohistochemistry (IHC). Methods We retrospectively analysed the data of 21 MBC patients who were treated in our centre from January 2018 to March 2022. Immunohistochemical analysis of arginase expression was performed in tumor and lymph node tissue with primary arginase-1 antibody (1:300 dilution). Results The mean patient age was 57 years (33–81 years). 10 patients (48%) had metastatic disease at presentation, while early breast cancer (EBC) and locally advanced breast cancer (LABC) constituted 19% and 33%, respectively. Invasive ductal carcinoma was the predominant histology, with luminal being the major subtype. Modified radical mastectomy was done in 9 patients (43%), and palliative chemotherapy was given to all metastatic patients. IHC analysis revealed a lack of arginase expression in the tumor tissue even though it was expressed in the surrounding neutrophils. Conclusion Contrary to the majority of existing literature, ours was an IHC-based study, which provides a more accurate estimation of arginase expression at the cellular level. The lack of arginase expression obtained in our study may point towards the non-expression of the enzyme in MBC. This suggests that arginase is not a tissue biomarker in MBC. Taking other studies with protein expression into account, arginase should be treated, if necessary, only as a blood biomarker.

Quercetin inhibits truncated isoform of dopamine- and cAMP-regulated phosphoprotein as adjuvant treatment for trastuzumab therapy resistance in HER2-positive breast cancer

Trastuzumab resistance is one of the causes of poor prognosis in patients with human epidermal growth factor receptor 2 (HER2)-positive (HER2+) breast cancer (BC). The truncated isoform of dopamine- and cAMP-regulated phosphoprotein (t-DARPP) has been reported to be involved in trastuzumab therapy resistance and promoting tumor progression. To evaluate the t-DARPP expression in BC, paired tumors and surrounding normal tissues were analyzed by real-time polymerase chain reaction and confirmed higher DARPP-32 kDa family mRNA expression in HER2+ BC tumor tissues. We established 2 patient-derived xenografts (PDX) mice models to test the efficacy of trastuzumab, named model 1 (non-responder) and model 2 (responder). t-DARPP and p95-HER2 protein-protein interactions were detected in PDX tumor tissue from non-responders using Förster resonance energy transfer assays. Instead, there is no response from the responder. Furthermore, mechanistic studies using transwell and Western blot assays demonstrated that t-DARPP could upregulate epithelial-mesenchymal transition signaling proteins, enhance p95-HER2 expression and promote cell migration. We found that quercetin effectively reduced t-DARPP expression in HER2+ BC cells. In t-DARPP ShRNA-suppressed cells, quercetin synergistically enhanced trastuzumab-induced apoptotic cell death and G2/M phase arrest. In conclusion, the combination of quercetin and trastuzumab treatment by targeting t-DARPP in HER2+ BC patients has the potential as a biomarker for mitigating drug resistance.

β2-microglobulin induced apoptosis of tumor cells via the ERK signaling pathway by directly interacting with HFE in HER2-overexpressing breast cancer

BackgroundOur previous study demonstrated that β2-microglobulin (β2M) promoted ER+/HER2– breast cancer survival via the SGK1/Bcl-2 signaling pathway. However, the role of β2M has not been investigated in ER–/HER2+ breast cancer. Here, we aimed to determine the role of β2M in ER–/HER2+ breast cancer.MethodsThe interaction between β2M and HFE was confirmed by co-immunoprecipitation, mass spectrometry, yeast two-hybrid screening, and His pull-down. The knockdown and overexpression of β2M or HFE were performed in MDA-MB-453 cells, and ERK signaling pathway was subsequently analyzed via western blotting. Apoptotic cells were detected using flow cytometer. β2M, HFE, and p-ERK1/2 were examined in tumor and paired adjacent tissues via immunohistochemistry.ResultsHFE was found to be an interacting protein of β2M in ER–/HER2+ breast cancer cells MDA-MB-453 by co-immunoprecipitation and mass spectrometry. A yeast two-hybrid system and His-pull down experiments verified that β2M directly interacted with HFE. β2M and HFE as a complex were mainly located in the cytoplasm, with some on the cytomembrane of MDA-MB-453 cells. In addition to breast cancer cells BT474, endogenous β2M directly interacted with HFE in breast cancer cells MDA-MB-453, MDA-MB-231, and MCF-7. β2M activated the ERK signaling pathway by interacting with HFE and induced apoptosis of MDA-MB-453 cells. The expression of HFE and p-ERK1/2 showed significantly high levels in HER2-overexpressing breast cancer tumor tissue compared with adjacent normal tissue, consistent with the results obtained from the cell experiments.Conclusionsβ2M induced apoptosis of tumor cells via activation of the ERK signal pathway by directly interacting with HFE in HER2-overexpressing breast cancer.

Exosomal circ-0100519 promotes breast cancer progression via inducing M2 macrophage polarisation by USP7/NRF2 axis.

Breast cancer (BC) is one of the most prevalent malignant tumours that threatens women health worldwide. It has been reported that circular RNAs (circRNAs) play an important role in regulating tumour progression and tumour microenvironment (TME) remodelling. Differentially expression characteristics and immune correlations of circRNAs in BC were verified using high-throughput sequencing and bioinformatic analysis. Exosomes were characterised by nanoparticle transmission electron microscopy and tracking analysis. The biological function of circ-0100519 in BC development was demonstrated both in vitro and in vivo. Western blotting, RNA pull-down, RNA immunoprecipitation, flow cytometry, and luciferase reporter were conducted to investigate the underlying mechanism. Circ-0100519 was significant abundant in BC tumour tissues and related to poor prognosis. It can be encapsulated into secreted exosomes, thereby promoting BC cell invasion and metastasis via inducing M2-like macrophages polarisation.Mechanistically, circ-0100519 acted as a scaffold to enhance the interaction between the deubiquitinating enzyme ubiquitin-specific protease 7 (USP7) and nuclear factor-like 2 (NRF2) in macrophages, inducing the USP7-mediated deubiquitination of NRF2. Additionally,HIF-1α could function as an upstream effector to enhance circ-0100519 transcription. Our study revealed that exosomal circ-0100519 is a potential biomarker for BC diagnosis and prognosis, and the HIF-1α inhibitor PX-478 may provide a therapeutic target for BC.

CCDC88C, an O-GalNAc glycosylation substrate of GALNT6, drives breast cancer metastasis by promoting c-JUN-mediated CEMIP transcription

Coiled-coil domain containing 88C (CCDC88C) is a component of non-canonical Wnt signaling, and its dysregulation causes colorectal cancer metastasis. Dysregulated expression of CCDC88C was observed in lymph node metastatic tumor tissues of breast cancer. However, the role of CCDC88C in breast cancer metastasis remains unclear. To address this, the stable BT549 and SKBR3 cell lines with CCDC88C overexpression or knockdown were developed. Loss/gain-of-function experiments suggested that CCDC88C drove breast cancer cell motility in vitro and lung and liver metastasis in vivo. We found that CCDC88C led to c-JUN-induced transcription activation. Overlapping genes were identified from the genes modulated by CCDC88C and c-JUN. CEMIP, one of these overlapping genes, has been confirmed to confer breast cancer metastasis. We found that CCDC88C regulated CEMIP mRNA levels via c-JUN and it exerted pro-metastatic capabilities in a CEMIP-dependent manner. Moreover, we identified the CCDC88C as a substrate of polypeptide N-acetylgalactosaminyltransferase 6 (GALNT6). GALNT6 was positively correlated with CCDC88C protein abundance in the normal breast and breast cancer tissues, indicating that GALNT6 might be associated with expression patterns of CCDC88C in breast cancer. Our data demonstrated that GALNT6 maintained CCDC88C stability by promoting its O-linked glycosylation, and the modification was critical for the pro-metastatic potential of CCDC88C. CCDC88C also could mediate the pro-metastatic potential of GALNT6 in breast cancer. Collectively, our findings uncover that CCDC88C may increase the risk of breast cancer metastasis and elucidate the underlying molecular mechanisms.

Mitigating inflammatory response in breast cancer patients: the inhibitory effect of acupuncture and emotional nursing on the ST8SIA6-AS1/LINC00504/p38 pathway

IntroductionBreast cancer patients often suffer from psychological distress such as anxiety and depression, which can exacerbate inflammation and potentially hinder treatment outcomes. This research investigates the effects of emotional nursing combined with acupuncture on inflammation in breast cancer patients diagnosed with liver depression and stagnation.Material and methodsA total of 40 breast cancer patients with liver depression and stagnation were divided into 2 groups: a control group (n = 20) and an observational group (n = 20). The control group was subjected to standard nursing care, whereas the observational group received a synergised regimen of emotional nursing and acupuncture alongside the regular nursing care. Depression and anxiety levels were assessed using the Self-rating Depression Scale (SDS) and Self-rated Anxiety Scale (SAS). Inflammatory cytokine levels were analysed using ELISA and Western blot, while cell viability and apoptosis rate in breast cancer cells were assessed through specific assays.ResultsEmotional nursing and acupuncture significantly reduced psychological distress and inflammation. Moreover, a significant reduction in ST8SIA6-AS1 and LINC00504 expression levels in tumour tissues was observed following the emotional nursing and acupuncture intervention – 2 entities known to be elevated in breast cancer scenarios and associated with patient survival. Additionally, this therapy restrained the activation of p38 signalling in breast cancer tumour tissues. Furthermore, the silencing of ST8SIA6-AS1 and LINC00504 dampened IL-6-mediated inflammation in breast cancer cells through the p38 pathway.ConclusionsEmotional nursing and acupuncture potentially reduce inflammation in breast cancer patients with liver depression and stagnation by modulating specific factors and deactivating the p38 pathway.

GALNT14 in association with GDF-15 promotes stemness and drug resistance through β-catenin signalling pathway in breast cancer.

Altered glycosylation plays a role in carcinogenesis. GALNT14 promotes cancer stem-like properties and drug resistance. GDF-15 is known to induces drug resistance and stemness markers for maintenance of breast cancer (BC) stem-like cell state. Currently there is lack of data on association of GDF-15 and GALNTs. In this study, the expression and interaction of GALNT14 and GDF-15 with stemness (OCT4 and SOX2) and drug resistance (ABCC5) markers were evaluated in BC. We investigated tumour tissue from 30 BC patients and adjacent non-tumour tissues. Expression of serum GALNT14 from BC patients and matched healthy controls was evaluated. Expression of GALNT14, GDF-15, OCT4, SOX2, ABCC5, and β-catenin in BC tissue was determined by RT-PCR. Knockdown of GALNT14 and GDF-15 in the MCF-7 cell line was done through siRNA, gene expression and protein expression of β-catenin by western blot were determined. A significant increase in the expression of GALNT14, GDF-15, OCT4, SOX2, ABCC5, and β-catenin was observed in BC tumour tissues compared to adjacent non-tumour tissues. The serum level of GALNT14 was significantly high in BC patients (80.7 ± 65.3 pg/ml) compared to healthy controls (12.2 ± 9.12 pg/ml) (p < 0.000). To further analyse the signalling pathway involved in BC stemness and drug resistance, GALNT14 and GDF-15 were knocked down in the MCF-7 cell line, and it was observed that after knockdown, the expression level of OCT4, SOX2, ABCC5, and β-catenin was decreased, and co-knockdown with GALNT14 and GDF-15 further decreased the expression of genes. It can be concluded that GALNT14, in association with GDF-15, promotes stemness and intrinsic drug resistance in BC, possibly through the β-catenin signalling pathway.

The protective mechanism of Tao Hong Si Wu decoction against breast cancer through regulation of EGFR/ERK1/2 signaling

Ethnopharmacological relevanceTao Hong Si Wu Decoction (THSWD), a traditional Chinese herbal medicine, is widely utilized in clinical settings, either alone or in combination with other medications, for the treatment of breast cancer.Aim of the study: The specific targeting molecule(s) of THSWD and its associated molecular mechanisms remain unclear. This research aims to elucidate the underlying molecular mechanisms of THSWD in the treatment of breast cancer. Materials and methodsThe pharmacological properties of THSWD were investigated in breast cancer cells and tumor tissues using a range of methods including Acridine Orange/Ethidium Bromide (AO/EB) staining, Transwell assay, flow cytometry, immunofluorescence assay, and breast cancer mice models. ResultsOur findings demonstrate that THSWD induces necrosis and/or apoptosis in breast cancer cells, while significantly inhibiting cell migration. Target proteins of THSWD in anticancer activity include EGFR, RAS, and others. THSWD treatment for breast cancer is associated with the EGFR/ERK1/2 signaling pathway. ConclusionOur findings offer initial insights into the primary mechanism of action of THSWD in breast cancer treatment, indicating its potential as a complementary therapy deserving further investigation.

Cu superparticle-based aggregation induced enhancement strategy with PVDF-HFP/CeVO4 NP sensing interface for miR-103a detection

Aggregation-induced emission (AIE) has been widely used in research on electrochemiluminescence (ECL) due to its excellent luminescence intensity. In this work, copper superparticles (Cu SPs) were used to construct ECL biosensor to detect the microRNA-103a (miRNA-103a) in triple-negative breast cancer (TNBC) tumor tissues. Firstly, GSH-capped copper clusters were used as precursors to prepare Cu SPs by the AIE effect. Compared with clusters, Cu SPs possessed higher luminescence performance and energy stability, making them an ideal choice for ECL nanoprobe. The film of PVDF-HFP/CeVO4 NPs was constructed and modified with CPBA and GSH as the sensing interface (PCCG). The PCCG film displayed good conductivity and hydrophilicity, and desirable mechanical stability. Moreover, the PCCG film can induce high carrier mobility rates and dissociate large amounts of the co-reactant K2S2O8 to enhance the ECL intensity of Cu SPs. As a result, the prepared ECL sensor with the catalyzed hairpin assembly (CHA) strategy was employed to quantify miRNA-103a in the range of 100 fM to 100 nM. The biosensor provided a novel analytical approach for the clinical diagnosis of TNBC.

Abstract P53: Inhibition of STING/Galectin-9 Axis Sensitize Anthracyclines Treatment And Induce Anti-tumor Immunity

Abstract Anthracyclines, are a class of conventional and routinely used firstline chemotherapy drugs to treat breast cancer. Immunogenic cell death (ICD) is characterized by the exposure of danger signals that promote dendritic cell maturation and antigen presentation and is often associated with the induction of cancer cell-intrinsic IFN-I signaling pathway. In addition, among multiple chemotherapeutic drugs such as doxorubicin (Dox) is well-known to promote tumor immunogenicity by interfering with DNA synthesis. Galectin-9 (Gal-9), as a member of β-galactoside-binding protein family, has been demonstrated to induce T cell death and promote immunosuppression in the tumor microenvironment. In addition, it has been shown that some interferon (IFN) and interleukin (IL) factors can induce Gal-9 expression. However, the mechanism cross-talk between anthracyclines and Gal-9 immunecheckpoint inhibitor remains unknown. Here we show that doxorubicin induces PD-L1 expression in human breast cancer cell lines and animal models. Mechanistically, doxorubicin promoted IFNβ expression, which in turn enhanced doxorubicin-induced Gal-9. Furthermore, we discovered that doxorubicin induces tumor Gal-9 via STING upregulation. The combination of doxorubicin and anti-Gal-9 therapy compared with each agent alone significantly increased the therapeutic efficacy in vivo. Clinically, a higher Gal-9 and p-STING level in the tumor region of after-treatment anthracyclines as compared to before treatment is indicated in breast cancer tumor tissue. Taken together, our study demonstrates crosstalk between anthracyclines-induced ICD and tumor-associated immunosuppression and provides a novel therapeutic strategy by combining anthracyclines and Gal-9 antibody in breast cancer. Citation Format: Xian Sun, Wei-Jan Wang, Jilu Lang, Riyao Yang, Wan-Jou Shen, Linlin Sun, Mien-Chie Hung. Inhibition of STING/Galectin-9 Axis Sensitize Anthracyclines Treatment And Induce Anti-tumor Immunity [abstract]. In: Proceedings of Frontiers in Cancer Science; 2023 Nov 6-8; Singapore. Philadelphia (PA): AACR; Cancer Res 2024;84(8_Suppl):Abstract nr P53.

QSOX2 Upregulated in triple-negative breast cancer exacerbates patient prognosis by stabilizing integrin β1

Breast cancer (BC) remains a significant global health threat, with triple-negative breast cancer (TNBC) standing out as a particularly aggressive subtype lacking targeted therapies. Addressing this gap, we propose Quiescin Q6 sulfhydryl oxidase 2 (QSOX2) as a potential therapeutic target, a disulfide bond-forming enzyme implicated in cancer progression. Using publicly available datasets, we conducted a comprehensive analysis of QSOX2 expression in BC tumor and non-tumor tissues, assessing its specificity across different molecular subtypes. We further explored correlations between QSOX2 expression and patient outcomes, utilizing datasets like TCGA and METABRIC. In addition, we performed in vitro experiments to evaluate QSOX2 expression in BC cell lines and investigate the effects of QSOX2 knockdown on various TNBC cellular processes, including cell proliferation, apoptosis resistance, migration, and the epithelial-to-mesenchymal transition (EMT). Our results reveal significantly elevated QSOX2 expression in BC tumor tissues, particularly in TNBC, and establish an association between high QSOX2 expression and increased patient mortality, cancer progression, and recurrence across various BC subtypes. Notably, QSOX2 knockdown in TNBC cell lines reduces cell proliferation, enhances apoptosis, and suppresses migration, potentially mediated through its influence on the EMT process. Furthermore, we identify a significant link between QSOX2 and integrin β1 (ITGB1), suggesting that QSOX2 enhances ITGB1 stability, subsequently exacerbating the malignancy of TNBC. In conclusion, elevated QSOX2 expression emerges as a key factor associated with adverse patient outcomes in BC, particularly in TNBC, contributing to disease progression through various mechanisms, including the modulation of ITGB1 stability. Our findings underscore the potential of targeting QSOX2 as a therapeutic strategy for improving patient prognoses not only in TNBC but also in other BC subtypes.

Long noncoding RNA DLEU2 and ROR1 pathway induces epithelial-to-mesenchymal transition and cancer stem cells in breast cancer

Breast cancer (BC) patient who receives chemotherapy for an extended length of time may experience profound repercussions in terms of metastases and clinical outcomes due to the involvement of the epithelial-to-mesenchymal transition (EMT) mechanism and enriched cancer stem cells (CSCs). BC cells that express high levels of lncRNA deleted in lymphocytic leukemia-2 (lncRNA DLEU2) and type I tyrosine kinase-like orphan receptor ROR1 (ROR1) may play roles in the enhanced ability of the activation EMT and CSC induction. Here we find that lncRNA DLEU2 and ROR1 are specifically upregulated in tumor tissues compared to their normal counterparts in TCGA, PubMed GEO datasets, and samples from archived breast cancer tumor tissues. Following chemotherapy, lncRNA DLEU2 and ROR1 were enhanced in BC tumor cells, coupled with the expression of CSCs, EMT-related genes, and BMI1. Mechanistically, ROR1 and lncRNA DLEU2 overexpression led to enhanced tumor cell proliferation, inhibition of apoptosis, cell-cycle dysregulation, chemoresistance, as well as BC cell’s abilities to invade, migrate, develop spheroids. These findings imply that the role of lncRNA DLEU2 and ROR1 in BC therapeutic failure is largely attributed to EMT, which is intricately linked to enriched CSCs. In conclusion, our findings indicate that a lncRNA DLEU2 and ROR1-based regulatory loop governs EMT and CSC self-renewal, implying that targeting this regulatory pathway may improve patients’ responses to chemotherapy and survival.

Tumor Cell-Derived Exosomal miR-191-5p Activates M2-Subtype Macrophages Through SOCS3 to Facilitate Breast Cancer.

Differential activation of macrophages is associated with poor progression of breast cancer (BC). Many reports have elucidated the important involvement of exosomes produced by cancer cells in remodeling the macrophage activation phenotype to promote tumor expansion and invasion. However, the underlying mechanisms by which exosomes secreted by BC cells facilitate macrophage M2 polarization remain enigmatic and worth exploring. In this study, quantitative real-time PCR (RT-qPCR) was used to investigate miR-191-5p expression in BC tumor tissues and cells. Cell counting kit 8 (CCK-8), transwell, and flow cytometry were applied to assess the functional role of miR-191-5p in BC. Isolated nano-vesicles were identified using transmission electron microscopy and western blotting. We also observed that miR-191-5p was significantly elevated in BC clinical samples and that inhibition of miR-191-5p hindered the growth and metastasis of BC cells. Importantly, BC cells successfully accelerated macrophage M2-like polarization by directly transferring exosomes to macrophages, resulting in increased miR-191-5p levels in macrophages. Mechanistically, exosomal miR-191-5p directly inhibited the suppressors of cytokine signaling 3 (SOCS3) expression in macrophages and aggravated macrophage M2 polarization. Similarly, si-SOCS3 transfected macrophages boosted BC cell migration and invasion in a positive feedback manner. Overall, our results manifested a pro-growth and pro-metastatic role between the two cells by elucidating the crucial role of exosomal miR-191-5p in stimulating M2 macrophage polarization and mediating communication between BC cells and macrophages. These findings opened up new horizons for the development of BC therapeutic strategies.

YTHDF1 shapes “cold” tumor and inhibits CD8+ T cells infiltration and function in breast cancer

While YTH N6-methyladenosine RNA binding protein 1 (YTHDF1) was recognized as a crucial contributor in the development and immune-related regulation of various types of tumors, its function in the immune response of breast cancer has largely remained uninvestigated. Through analysis of public databases, we found YTHDF1 as a highly expressed gene in breast cancers and confirmed this finding in breast cancer cells and clinical specimens from our center. Subsequently, we examined the link between YTHDF1 expression and immune cells and molecules by utilizing immune-related public databases and algorithm. We further validated our findings through cellular and animal experiments, as well as RNA sequencing. YTHDF1 was found highly expressed in tumor tissues of breast cancer, which negatively correlated with patient survival. The downregulation of YTHDF1 promoted the expression of pro-inflammatory markers and improved the anti-cancer ability of immune cells in breast cancer. RNA sequencing analysis revealed that YTHDF1 knockdown resulted in enrichment of differential genes in signal transduction pathways. Additionally, in vitro experiments showed that immune cells had higher cytotoxicity against breast cancer cells with decreased YTHDF1 expression. Moreover, in vivo studies indicated that YTHDF1 promoted breast cancer growth while inhibiting CD8+ T cell infiltration and function. Our study demonstrates that YTHDF1 plays a crucial role in establishing a “cold” tumor microenvironment in breast cancer by inhibiting the release of pro-inflammatory cytokines from cancer cells. As a result, the infiltration and functional differentiation of anti-tumor CD8+ T cells are hindered, ultimately resulting in the immune evasion of breast cancer.

Activation of kappa opioid receptor (KOR) inhibits estrogen receptor (ER)-positive breast cancer through the KOR-ER-XBP1 pathway

Opioids are commonly used in patients with breast cancer (BC), both for perioperative analgesia and for the relief of chronic cancer pain. Studies have suggested a potential association of opioid receptors (ORs) with the prognosis of BC patients. However, the exact roles of different ORs remain poorly understood. In this study, we found that κ opioid receptor (KOR) was the only OR (among the four types of ORs) that was significantly decreased in BC tumor tissues compared with peritumoral normal tissues. In addition, decreased expression of KOR correlated with poor clinical outcomes in patients with estrogen receptor (ER)-positive BC. In vitro studies confirmed the anti-tumor effects of KOR agonists in ER-positive MCF-7 and T47D cells by showing that activation of KOR significantly inhibited cellular proliferation and promoted apoptosis. Using Gene Ontology (GO), Kyoto Encyclopedia of Genes and Genomes (KEGG), and protein-protein interaction network (PPI) analysis, we found that KOR-ER-XBP1 was the potential downstream signaling pathway mediating the anti-tumor effects of KOR agonist. Finally, the role of XBP1 was confirmed as KOR activation-induced increase in the proliferative and monoclonal formation abilities of ER-positive BC cells were both significantly abolished after silencing of XBP1. These findings provide us a better understanding of the roles of different ORs in BC, identifying KOR agonists as better opioids than traditional μ opioid receptor (MOR) agonists for providing analgesia in ER-positive BC patients owing to their association with better prognosis.

Intracellular Fusobacterium nucleatum infection increases METTL3-mediated m6A methylation to promote the metastasis of esophageal squamous cell carcinoma

IntroductionThe tumor-associated microbiota plays a vital role in cancer development. Accumulating evidence shows that Fusobacterium nucleatum (Fn) participates in the progression of multiple tumor types. However, the underlying mechanisms remain unclear. ObjectivesThis study examined the expression of methyltransferase-like protein 3 (METTL3) during Fn infection and elucidated the function and pathway of Fn-induced m6A methylation in esophageal squamous cell carcinoma (ESCC). MethodsThe abundance of Fn in patient tissues was determined by qPCR. Western blot, qRT-PCR, and immunohistochemistry were performed to measure METTL3 expression in cells and tissues. METTL3 function was evaluated in vitro by colony formation and cell migration assays. MeRIP-qPCR was performed to determine the relationship between METTL3 and c-Myc. In addition, the half-lives of genes that are downstream of METTL3 were determined with RNA stability assays. ResultsFn was enriched in hepatocellular carcinoma (HCC), breast cancer (BRCA), ESCC, and colorectal cancer (CRC) tumor tissues. METTL3 expression was positively associated with Fn abundance in ESCC tissues. Fn could survive and proliferation as well as increase METTL3 expression in ESCC, HCC, CRC, and BRCA cells. Moreover, METTL3 overexpression promoted ESCC cells proliferation, migration in vivo and in vitro. Mechanistically, Intracellular Fn infection increases METTL3 transcription. METTL3 promoted c-Myc mRNA methylation in the 3′-untranslated Region (3′-UTR) and enhanced its mRNA stability in a YTH N6-Methyladenosine RNA binding protein 1(YTHDF1)-dependent manner, which contributes to Fn induced ESCC proliferation and metastasis. ConclusionsThis study indicates that intracellular Fn infection promotes ESCC development and metastasis, and eradicating Fn infection may be a promising strategy for treating ESCC.