Breast Cancer Tissues Research Articles

The endogenous association among MMP2/miR-1248/Circ_0087558/miR-643/ MAP2K6 axis can contribute to brain metastasis in basal-like subtype of breast cancer

Brain metastasis in basal-like breast cancer poses a significant challenge in cancer management due to its aggressive nature and limited treatment options. This study conducted a comprehensive analysis to explore the potential role of circular RNAs (circRNAs) as members of endogenous networks in developing breast cancer brain metastasis.Here, we utilized RNA sequencing data from primary breast cancer and brain metastasis tissue with basal-like subtype (n = 11). After quality controlling and preprocessing of fastq files, gene expression of mRNA and circRNAs were extracted from matched samples and normalized. Then, we employed the weighted gene co-expression network analysis approach to identify brain metastasis-associated circRNA modules (SpearmanCorrelation>0.5, P−value<0.05). Moreover, we found five protein-coding genes of PHLDA1, SLC12A2, MMP2, RGP1, and MAP2K6, significantly upregulated in brain metastatic tissues compared to primary breast cancer (FDR<0.05). These genes were enriched in the "GnRH signaling pathway" and "Fluid shear stress and atherosclerosis" pathways (FDR<0.05).Next, to explore the potential interactions between circRNAs and protein-coding genes, we reconstructed a competing endogenous RNA (ceRNA) network using mutual miRNAs between the circRNA module and upregulated mRNAs. Notably, we could detect two axes of circ_0087558/miR-604/MMP2 and MMP2/miR-1248/Circ_0087558/miR-643/MAP2K6 in ceRNA network.In conclusion, the identified circRNA-miRNA-mRNA axes might be therapeutic targets or diagnostic biomarkers for this challenging subtype of breast cancer. However, due to the small number of samples, further experimental validations are essential.

Effect of microRNA-141-3p, E2F3, CDK3, and KAT2B overexpression on histologic tumor grade and metastasis status in untreated breast cancer tissues

Introduction: Increasing evidence has reported gene expression alterations in breast cancer (BC) tissues, necessitating their investigating to highlight the molecular basis of the disease development or progression. This study investigated the expression of miR-141, E2F3, CDK3, TP53, and KAT2B, and their association with histologic grade and metastasis in BC tissues. Methods: The RNA expression level of miR-141, E2F3, CDK3, TP53, and KAT2B genes was analyzed in 23 BC and 23 normal tissue samples by RT-qPCR. The associations of the expression level of these genes with clinicopathological features of the BC tissue samples were evaluated. The study also explored the correlation between RNA levels of genes and miR-141. Results: Expression of miR-141, E2F3, CDK3, and KAT2B demonstrated significantly higher levels in BC tumor than normal tissues. TP53 expression showed an increase in tumor compared to normal tissues, although it was insignificant. Moreover, increased RNA expression of miR-141, E2F3, CDK3, and KAT2B corresponded to the advanced stage and regional metastasis of BC. Additionally, the results demonstrated a significant correlation between RNA expression levels of miR-141 with CDK3 and E2F3 with KAT2B. Conclusion: Our findings highlighted clinicopathologic indicators that were relevant to aggressive BC. Besides, Correlations between overexpression of miR-141, E2F3, CDK3, and KAT2B in BC tissues suggest regulatory effects. Taken together, it seems results of this study could provide evidence that dysregulation of gene expression contributes significantly to unveiling the underlying molecular basis of BC.

AGEs induce MMP-9 promoter demethylation through the GADD45α-mediated BER pathway to promote breast cancer metastasis in patients with diabetes.

Scientific evidence has linked diabetes to a higher incidence and increased aggressiveness of breast cancer; however, mechanistic studies of the numerous regulators involved in this process are insufficiently thorough. Advanced glycation end products (AGEs) play an important role in the chronic complications of diabetes, but the mechanisms of AGEs in breast cancer are largely unexplored. In this study, we first demonstrate that high AGE levels in breast cancer tissues are associated with the diabetic state and poor patient outcomes. Furthermore, AGEs interact with the receptor for AGEs (RAGE) to promote breast cancer cell migration and invasion. Mechanistically, based on RNA sequencing (RNA-seq) analysis, we reveal that growth arrest and DNA damage gene 45α (GADD45α) is a vital protein upregulated by AGEs through a P53-dependent pathway. Next, GADD45α recruits thymine DNA glycosylase for base excision repair to form the demethylation complex at the promoter region of MMP-9 and enhance MMP-9 transactivation through DNA demethylation. Overall, our results indicate a critical regulatory role of AGEs in patients with breast cancer and diabetes and reveal a novel mechanism of epigenetic modification in promoting breast cancer metastasis.

Overexpression of CDHR2 inhibits proliferation of breast cancer cells by inhibiting the PI3K/Akt pathway

To investigate the mechanism by which CDHR2 overexpression inhibits breast cancer cell growth and cell cycle pragression via the PI3K/Akt signaling pathway. Bioinformatic analysis was performed to investigate CDHR2 expression in breast cancer and its correlation with survival outcomes of the patients. Immunohistochemistry was used to examine CDHR2 expressions in surgical specimens of tumor and adjacent tissues from 10 patients with breast cancer. CDHR2 expression levels were also detected in 5 breast cancer cell lines and a normal human mammary epithelial cell line using qRT-PCR and Western blotting. Breast cancer cell lines MDA-MB-231 and MCF7 with low CDHR2 expression were transfected with a CDHR2-overexpressing plasmid, and the changes in cell proliferation and cell cycle were evaluated using CCK-8 assay, EdU assay, and cell cycle assay; the changes in expressions of PI3K/Akt signaling pathway and cell cycle pathway proteins were detected with Western blotting. Bioinformatic analysis showed low CDHR2 expression level in both breast cancer and adjacent tissues without significant difference between them (P > 0.05), but breast cancer patients with a high expression of CDHR2 had a more favorable prognosis. Immunohistochemistry, qRT-PCR and Western blotting showed that the expression of CDHR2 was significantly down-regulated in breast cancer tissues and breast cancer cells (P < 0.01), and its overexpression strongly inhibited cell proliferation, caused cell cycle arrest, and significantly inhibited PI3K and Akt phosphorylation and the expression of cyclin D1. Overexpression of CDHR2 inhibits proliferation and causes cell cycle arrest in breast cancer cells possibly by inhibiting the PI3K/Akt signaling pathway.

Evaluating the effect of tissue stimulation at different frequencies on breast lesion classification based on nonlinear features using a novel radio frequency time series approach

ObjectiveRadio Frequency Time Series (RF TS) is a cutting-edge ultrasound approach in tissue typing. The RF TS does not provide dynamic insights into the propagation medium; when the tissue and probe are fixed. We previously proposed the innovative RFTSDP method in which the RF data are recorded while stimulating the tissue. Applying stimulation can unveil the mechanical characteristics of the tissue in RF echo. Materials and methodsIn this study, an apparatus was developed to induce vibrations at different frequencies to the medium. Data were collected from four PVA phantoms simulating the nonlinear behaviors of healthy, fibroadenoma, cyst, and cancerous breast tissues. Raw focused, raw, and beamformed ultrafast data were collected under conditions of no stimulation, constant force, and various vibrational stimulations using the Supersonic Imagine Aixplorer clinical/research ultrasound imaging system. Time domain (TD), spectral, and nonlinear features were extracted from each RF TS. Support Vector Machine (SVM), Random Forest, and Decision Tree algorithms were employed for classification. ResultsThe optimal outcome was achieved using the SVM classifier considering 19 features extracted from beamformed ultrafast data recorded while applying vibration at the frequency of 65 Hz. The classification accuracy, specificity, and precision were 98.44 ± 0.20 %, 99.49± 0.01 %, and 98.53± 0.04 %, respectively. Applying RFTSDP, a notable 24.45 % improvement in accuracy was observed compared to the case of fixed probe assessing the recorded raw focused data. ConclusionsExternal vibration at an appropriate frequency, as applied in RFTSDP, incorporates beneficial information about the medium and its dynamic characteristics into the RF TS, which can improve tissue characterization.

Bidirectional linkage of DNA barcodes for the multiplexed mapping of higher-order protein interactions in cells.

Capturing the full complexity of the diverse hierarchical interactions in the protein interactome is challenging. Here we report a DNA-barcoding method for the multiplexed mapping of pairwise and higher-order protein interactions and their dynamics within cells. The method leverages antibodies conjugated with barcoded DNA strands that can bidirectionally hybridize and covalently link to linearize closely spaced interactions within individual 3D protein complexes, encoding and decoding the protein constituents and the interactions among them. By mapping protein interactions in cancer cells and normal cells, we found that tumour cells exhibit a larger diversity and abundance of protein complexes with higher-order interactions. In biopsies of human breast-cancer tissue, the method accurately identified the cancer subtype and revealed that higher-order protein interactions are associated with cancer aggressiveness.

LncRNA OIP5-AS1 Upregulates the Cyclin D2 Levels to Promote Metastasis of Breast Cancer by Targeting miR-150-5p.

Breast cancer (BC) is a cancer that seriously affects women's health. BC cell migration increases the mortality of BC patients. Current studies have shown that long noncoding RNAs (LncRNAs) are related to the metastasis mechanism of BC. This study aimed to explore the function and role of LncRNA OIP5-AS1 in BC. And we analyzed its regulatory mechanism and related modification process. Our study analyzed the expression pattern of OIP5-AS1 in BC tissues and cell lines by qRT-PCR. The effects of OIP5-AS1 on the function of BC cells were detected by CCK-8 and transwell experiments. Bioinformatics analysis and double luciferase reporter gene detection were used to confirm the correlation between OIP5-AS1 and miR-150-5p and between miR-150-5p and Cyclin D2 (CCND2). The rescue test analyzed the effect of miR-150-5p regulating OIP5-AS1. In addition, the N6-methyladenosine (m6A) modification process of OIP5-AS1 was analyzed by RNA m6A dot blot, RIP assay, and double luciferase report experiment. OIP5-AS1 was significantly upregulated in BC tissues and cell lines. OIP5-AS1 knockdown inhibited BC cell viability, migration and invasion. OIP5-AS1 upregulated CCND2 by binding with miR-150-5p. This process affected the metastasis of BC. Higher degree of m6A methylation was confirmed in BC cell lines. There were some binding sites between methyltransferase like 3 (METTL3) and OIP5-AS1. Moreover, the silencing of METTL3 inhibited the OIP5-AS1 expression through decreasing the m6A methylation levels. LncRNA OIP5-AS1 promoted cell viability and metastasis of BC cells by targeting miR-150-5p/CCND2 axis. This process was modified by m6A methylation of METTL3.

TFAP2A downregulation mediates tumor-suppressive effect of miR-8072 in triple-negative breast cancer via inhibiting SNAI1 transcription

BackgroundTriple-negative breast cancer (TNBC) represents a highly aggressive subset of breast malignancies characterized by its challenging clinical management and unfavorable prognosis. While TFAP2A, a member of the AP-2 transcription factor family, has been implicated in maintaining the basal phenotype of breast cancer, its precise regulatory role in TNBC remains undefined.MethodsIn vitro assessments of TNBC cell growth and migratory potential were conducted using MTS, colony formation, and EdU assays. Quantitative PCR was employed to analyze mRNA expression levels, while Western blot was utilized to evaluate protein expression and phosphorylation status of AKT and ERK. The post-transcriptional regulation of TFAP2A by miR-8072 and the transcriptional activation of SNAI1 by TFAP2A were investigated through luciferase reporter assays. A xenograft mouse model was employed to assess the in vivo growth capacity of TNBC cells.ResultsSelective silencing of TFAP2A significantly impeded the proliferation and migration of TNBC cells, with elevated TFAP2A expression observed in breast cancer tissues. Notably, TNBC patients exhibiting heightened TFAP2A levels experienced abbreviated overall survival. Mechanistically, TFAP2A was identified as a transcriptional activator of SNAI1, a crucial regulator of epithelial-mesenchymal transition (EMT) and cellular proliferation, thereby augmenting the oncogenic properties of TFAP2A in TNBC. Moreover, miR-8072 was unveiled as a negative regulator of TFAP2A, exerting potent inhibitory effects on TNBC cell growth and migration. Importantly, the tumor-suppressive actions mediated by the miR-8072/TFAP2A axis were intricately associated with the attenuation of AKT/ERK signaling cascades and the blockade of EMT processes.ConclusionsOur findings unravel the role and underlying molecular mechanism of TFAP2A in driving tumorigenesis of TNBC. Targeting the TFAP2A/SNAI1 pathway and utilizing miR-8072 as a suppressor represent promising therapeutic strategies for treating TNBC.

USP11 modulates mitotic progression and senescence by regulating the p53-p21 axis through MDM2 deubiquitination

USP11 is overexpressed in colorectal cancer (CRC) and breast cancer tissues compared to normal tissues, suggesting a role in promoting cell proliferation and inhibiting cell death. In this study, we observed that depleting USP11 inhibits cell proliferation and delays cell cycle progression. This depletion leads to increased p53 protein levels due to an extended half-life, resulting in elevated p21 mRNA levels in a p53-dependent manner. The rise in p53 protein upon USP11 depletion is linked to a reduced half-life of MDM2, a known E3 ligase for p53, via enhanced polyubiquitination of MDM2. These findings indicate that USP11 might act as a deubiquitinase for MDM2, regulating the MDM2-p53-p21 axis. Additionally, USP11 depletion promotes the induction of senescent cells in a manner dependent on its deubiquitinase activity. Our findings provide insights into the physiological significance of high USP11 expression in primary tumors and its reduction in senescent cells, highlighting its potential as a therapeutic target.

The crosstalk between metabolic reprogramming and epithelial-mesenchymal transition and their synergistic roles in distant metastasis in breast cancer.

Metabolic reprogramming (MR) and epithelial-mesenchymal transition (EMT) are crucial phenomena involved in the distant metastasis of breast cancer (BRCA). This study aims to assess the risk of distant metastasis in BRCA patients based on MR and EMT processes and investigate their underlying mechanisms. Gene sets related to EMT and MR were downloaded. MR-related genes (MRG) and EMT-related genes (ERG) were obtained. Principal Component Analysis method was used to define the EMT Potential Index (EPI) and MR Potential Index (MPI) to quantify the EMT and MR levels in each tumor tissue. A linear scoring model, the Metastasis Score, was derived using the union of MRGs and ERGs to evaluate the risk of distant metastasis/recurrence in BRCA. The Metastasis Score was then validated in multiple datasets. Additionally, our study explored the underlying mechanism of the Metastasis Score and its association with tumor immunity, focusing on HPRT1 gene expression in breast cancer tissues of transfer and untransferred groups using experimental methods. A total of 59 MRGs and 30 ERGs were identified in the present study. Stratifying the dataset based on EPI and MPI revealed significantly lower survival rates (P < .05) in the MPI_high and EPI_high groups. Kaplan-Meier analysis indicated the lowest survival rate in the EPI-high + MPI-high group. The Metastasis Score demonstrated its ability to distinguish prognoses in GSE2034, GSE17705, and TCGA-BRCA datasets. Additionally, differences in mutated genes were found between the high- and the low-Metastasis Score groups, displaying significant associations with immune cell infiltration and anti-tumor immune status. Notably, the 13 genes included in the Metastasis Score showed a strong association with prognosis and tumor immunity. Immunohistochemistry and western blot results revealed high expression of the HPRT1 gene in the transfer group. This study established the Metastasis Score as a reliable tool for evaluating the risk of distant metastasis/recurrence in BRCA patients. Additionally, we identified key genes involved in MR and EMT crosstalk, offering valuable insights into their roles in tumor immunity and other relevant aspects.

Evaluation of Prostate-Specific Membrane Antigen (PSMA) Immunohistochemical Expression in Early-Stage Breast Cancer Subtypes.

Breast cancer, known for its diverse subtypes, ranks as one of the leading causes of cancer-related deaths. Prostate-specific membrane antigen (PSMA), primarily associated with prostate cancer, has also been identified in breast cancer, though its role remains unclear. This study aimed to evaluate PSMA expression across different subtypes of early-stage breast cancer and investigate its correlation with clinicopathological factors. This retrospective study included 98 breast cancer cases. PSMA expression was examined in both tumor cells and tumor-associated blood vessels. The analysis revealed PSMA expression in tumor-associated blood vessels in 88 cases and in tumor cells in 75 cases. Ki67 expression correlated positively with PSMA expression in blood vessels (p < 0.0001, RSpearman 0.42) and tumor cells (p = 0.010, RSpearman 0.26). The estrogen and progesterone receptor expression correlated negatively with PSMA levels in blood vessels (p = 0.0053, R Spearman -0.26 and p = 0.00026, R Spearman -0.347, respectively). Human epidermal growth factor receptor 2 (HER2) status did not significantly impact PSMA expression. We did not detect any statistically significant differences between breast cancer subtypes. These findings provide evidence for a heterogenous PSMA expression in breast cancer tissue and suggest its correlation with tumor aggressiveness. Despite the limited sample size, the study provides valuable insights into the potential of PSMA as a prognostic, diagnostic, and therapeutic target in the management of breast cancer.

Bioprinting native-like 3D micro breast cancer tissues utilizing existing cancer cell lines

Bioprinting native-like 3D micro breast cancer tissues utilizing existing cancer cell lines

SOSTDC1 Nuclear Translocation Facilitates BTIC Maintenance and CHD1-Mediated HR Repair to Promote Tumor Progression and Olaparib Resistance in TNBC.

Breast tumor-initiating cells (BTICs) of triple-negative breast cancer (TNBC) tissues actively repair DNA and are resistant to treatments including chemotherapy, radiotherapy, and targeted therapy. Herein, it is found that a previously reported secreted protein, sclerostin domain containing 1 (SOSTDC1), is abundantly expressed in BTICs of TNBC cells and positively correlated with a poor patient prognosis. SOSTDC1 knockdown impairs homologous recombination (HR) repair, BTIC maintenance, and sensitized bulk cells and BTICs to Olaparib. Mechanistically, following Olaparib treatment, SOSTDC1 translocates to the nucleus in an importin-α dependent manner. Nuclear SOSTDC1 interacts with the N-terminus of the nucleoprotein, chromatin helicase DNA-binding factor (CHD1), to promote HR repair and BTIC maintenance. Furthermore, nuclear SOSTDC1 bound to β-transducin repeat-containing protein (β-TrCP) binding motifs of CHD1 is found, thereby blocking the β-TrCP-CHD1 interaction and inhibiting β-TrCP-mediated CHD1 ubiquitination and degradation. Collectively, these findings identify a novel nuclear SOSTDC1 pathway in regulating HR repair and BTIC maintenance, providing insight into the TNBC therapeutic strategies.

Elevated expression of ELK1 promotes breast cancer cell growth and correlates with poor prognosis of breast cancer patients

Background: Breast cancer is the most common tumor in women and poses a serious threat to women’s physical and mental health. The ETS-like gene 1 (ELK1), upregulated in various malignancies, serves as a transcription regulatory factor. This study primarily investigates the biological functions and prognostic significance of ELK1 in breast cancer. Materials and Methods: We conducted an analysis of ELK1 expression in breast cancer and adjacent tissues using data from The Cancer Genome Atlas (TCGA), and validated these findings with clinical specimens. Additionally, we employed siRNA transfection, proliferation and apoptosis assays to elucidate the roles of ELK1 in breast cancer cells. Furthermore, we assessed the correlations between ELK1 expression and the tumor microenvironment, as well as tumor-infiltrating immune cells (TIICs), utilizing the ESTIMATE and CIBERSORT algorithms. Finally, we used Kaplan-Meier plots and COX regressions to identify prognostic factors, and developed a predictive alignment diagram to evaluate the prognostic significance of ELK1 in breast cancer. Results: A marked increase in ELK1 expression is evident in breast cancer tissues (P&lt;0.01). Experimental findings demonstrate that silencing ELK1 suppresses proliferation and promotes apoptosis in breast cancer cells. ELK1 plays a pivotal role in regulating the immune microenvironment of breast cancer. Furthermore, the alignment diagram indicates that ELK1 may serve as an independent prognostic factor for breast cancer patients. Conclusion: Our study reveals that ELK1 exhibits high expression level in breast cancer tissues and is associated with disease progression and poor prognosis.

Exosomal circSIPA1L3-mediated intercellular communication contributes to glucose metabolic reprogramming and progression of triple negative breast cancer

BackgroundBreast cancer is the most common malignant tumor, and metastasis remains the major cause of poor prognosis. Glucose metabolic reprogramming is one of the prominent hallmarks in cancer, providing nutrients and energy to support dramatically elevated tumor growth and metastasis. Nevertheless, the potential mechanistic links between glycolysis and breast cancer progression have not been thoroughly elucidated.MethodsRNA-seq analysis was used to identify glucose metabolism-related circRNAs. The expression of circSIPA1L3 in breast cancer tissues and serum was examined by qRT-PCR, and further assessed its diagnostic value. We also evaluated the prognostic potential of circSIPA1L3 by analyzing a cohort of 238 breast cancer patients. Gain- and loss-of-function experiments, transcriptomic analysis, and molecular biology experiments were conducted to explore the biological function and regulatory mechanism of circSIPA1L3.ResultsUsing RNA-seq analysis, circSIPA1L3 was identified as the critical mediator responsible for metabolic adaption upon energy stress. Gain- and loss-of-function experiments revealed that circSIPA1L3 exerted a stimulative effect on breast cancer progression and glycolysis, which could also be transported by exosomes and facilitated malignant behaviors among breast cancer cells. Significantly, the elevated lactate secretion caused by circSIPA1L3-mediated glycolysis enhancement promoted the recruitment of tumor associated macrophage and their tumor-promoting roles. Mechanistically, EIF4A3 induced the cyclization and cytoplasmic export of circSIPA1L3, which inhibited ubiquitin-mediated IGF2BP3 degradation through enhancing the UPS7-IGF2BP3 interaction. Furthermore, circSIPA1L3 increased mRNA stability of the lactate export carrier SLC16A1 and the glucose intake enhancer RAB11A through either strengthening their interaction with IGF2BP3 or sponging miR-665, leading to enhanced glycolytic metabolism. Clinically, elevated circSIPA1L3 expression indicated unfavorable prognosis base on the cohort of 238 breast cancer patients. Moreover, circSIPA1L3 was highly expressed in the serum of breast cancer patients and exhibited high diagnostic value for breast cancer patients.ConclusionsOur study highlights the oncogenic role of circSIPA1L3 through mediating glucose metabolism, which might serve as a promising diagnostic and prognostic biomarker and potential therapeutic target for breast cancer.

Human-derived Tumor-On-Chip model to study the heterogeneity of breast cancer tissue

One of the leading causes that complicate the treatment of some malignancies, including breast cancer, is tumor heterogeneity. In addition to inter-heterogeneity and intra-heterogeneity of tumors that reflect the differences between cancer cell characteristics, heterogeneity in the tumor microenvironment plays a critical role in tumor progression and could be considered an overlooked and a proper target for the effective selection of therapeutic approaches. Due to the difficulty of completely capturing tumor heterogeneity in conventional detection methods, Tumor-on-Chip (TOC) devices with culturing patient-derived spheroids could be an appropriate alternative. In this research, human-derived spheroids from breast cancer individuals were cultured for 6 days in microfluidic devices. To compare TOC data with conventional detection methods, immunohistochemistry (IHC) and ITRAQ data were employed, and various protein expressions were validated using the transcriptomic databases. The behavior of the spheroids in the collagen matrix and the cell viability were monitored over 6 days of culture. IHC and immunocytochemistry (ICC) results revealed that inter and intra-heterogeneity of tumor spheroids are associated with HER2/ER expression. HER2 expression levels revealed a more important biomarker associated with invasion in the 3D culturing of spheroids. The expression levels of CD163 (as a marker for Ma2 macrophages) and CD44 (a marker for cancer stem cells (CSCs)) were also evaluated. Interestingly, the levels of M2a macrophages and CSCs were higher in triple-negative specimens and samples that showed higher migration and invasion. Cell density and extracellular matrix (ECM) stiffness were also important factors affecting the migration and invasion of the spheroids through the matrix. Among these, rigid ECM revealed a more crucial role than cell density. To sum up, these research findings demonstrated that human-derived spheroids from breast cancer specimens in microfluidic devices provide a dynamic condition for predicting tumor heterogeneity in patients, which can help move the field forward for better and more accurate therapeutic strategies.

DNA methylation signatures provide novel diagnostic biomarkers and predict responses of immune therapy for breast cancer.

Breast cancer (BRCA) is one of the most common malignant tumors affecting women worldwide. DNA methylation modifications can influence oncogenic pathways and provide potential diagnostic and therapeutic targets for precision oncology. In this study, we used non-parametric permutation tests to identify differentially methylated positions (DMPs) between paired tumor and normal BRCA tissue samples from the Cancer Genome Atlas (TCGA) database. Then, we applied non-negative matrix factorization (NMF) to the DMPs to derive eight distinct DNA methylation signatures. Among them, signatures Hyper-S3 and Hypo-S4 signatures were associated with later tumor stages, while Hyper-S1 and Hypo-S3 exhibited higher methylation levels in earlier stages. Signature Hyper-S3 displayed an effect on overall survival. We further validated the four stage-associated signatures using an independent BRCA DNA methylation dataset from peripheral blood samples. Results demonstrated that 24 commonly hypomethylated sites in Hypo-S4 showed lower methylation in BRCA patients compared to healthy individuals, suggesting its potential as an early diagnostic biomarker. Furthermore, we found that methylation of 23 probes from four stage-related signatures exhibited predictive power for immune therapy response. Notably, methylation levels of all three probes from the Hypo-S4 and activity of the Hypo-S4 demonstrated highly positive relevance to PD-L1 gene expression, implying their significant predictive values for immunotherapy outcomes. GO and KEGG pathway enrichment analysis revealed that genes with these 23 immunotherapy-related methylation probes are mainly involved in glycan degradation or protein deglycosylation. These methylation signatures and probes may serve as novel epigenetic biomarkers for predicting tumor immunotherapy response. Our findings provide new insights into precision oncology approaches for BRCA.

Increased expression of REG3A promotes tumorigenic behavior in triple negative breast cancer cells

BackgroundIdentifying new targets in triple negative breast cancer (TNBC) remains critical. REG3A (regenerating islet-derived protein 3 A), a calcium-dependent lectin protein, was thoroughly investigated for its expression and functions in breast cancer.MethodsBioinformatics and local tissue analyses were employed to identify REG3A expression in breast cancer. Genetic techniques were employed to modify REG3A expression, and the resulting effects on the behaviors of breast cancer cells were examined. Subcutaneous xenograft models were established to investigate the involvement of REG3A in the in vivo growth of breast cancer cells.ResultsAnalysis of the TCGA database uncovered increased REG3A levels in human breast cancer tissues. Additionally, REG3A mRNA and protein levels were elevated in TNBC tissues of locally treated patients, contrasting with low expression in adjacent normal tissues. In primary human TNBC cells REG3A shRNA notably hindered cell proliferation, migration, and invasion while triggering caspase-mediated apoptosis. Similarly, employing CRISPR-sgRNA for REG3A knockout showed significant anti-TNBC cell activity. Conversely, REG3A overexpression bolstered cell proliferation and migration. REG3A proved crucial for activating the Akt-mTOR cascade, as evidenced by decreased Akt-S6K1 phosphorylation upon REG3A silencing or knockout, which was reversed by REG3A overexpression. A constitutively active mutant S473D Akt1 (caAkt1) restored Akt-mTOR activation and counteracted the proliferation inhibition and apoptosis induced by REG3A knockdown in breast cancer cells. Crucially, REG3A played a key role in maintaining mTOR complex integrity. Bioinformatics identified zinc finger protein 680 (ZNF680) as a potential REG3A transcription factor. Knocking down or knocking out ZNF680 reduced REG3A expression, while its overexpression increased it in primary breast cancer cells. Additionally, enhanced binding between ZNF680 protein and the REG3A promoter was observed in breast cancer tissues and cells. In vivo, REG3A shRNA significantly inhibited primary TNBC cell xenograft growth. In REG3A-silenced xenograft tissues, reduced REG3A levels, Akt-mTOR inhibition, and activated apoptosis were evident. ConclusionZNF680-caused REG3A overexpression drives tumorigenesis in breast cancer possibly by stimulating Akt-mTOR activation, emerging as a promising and innovative cancer target.

The VISTA/VSIG3/PSGL-1 axis: crosstalk between immune effector cells and cancer cells in invasive ductal breast carcinoma

A checkpoint protein called the V-domain Ig suppressor of T cell activation (VISTA) is important for controlling immune responses. Immune cells that interact with VISTA have molecules, or receptors, known as VISTA receptors. Immune system activity can be modified by the interaction between VISTA and its receptors. Since targeting VISTA or its receptors may be beneficial in certain conditions, VISTA has been studied in relation to immunotherapy for cancer and autoimmune illnesses. The purpose of this study was to examine the expression levels and interactions between VISTA and its receptors, VSIG3 and PSGL-1, in breast cancer tissues. IHC analysis revealed higher levels of proteins within the VISTA/VSIG3/PSGL-1 axis in cancer tissues than in the reference samples (mastopathies). VISTA was found in breast cancer cells and intratumoral immune cells, with membranous and cytoplasmic staining patterns. VISTA was also linked with pathological grade and VSIG3 and PSGL-1 levels. Furthermore, we discovered that the knockdown of one axis member boosted the expression of the other partners. This highlights the significance of VISTA/VSIG3/PSGL-1 in tumor stroma and microenvironment remodeling. Our findings indicate the importance of the VISTA/VSIG3/PSGL-1 axis in the molecular biology of cancer cells and the immune microenvironment.

METTL3-modified lncRNA DSCAM-AS1 promotes breast cancer progression through inhibiting ferroptosis.

Numerous studies have indicated that N6-methyladenosine (m6A) and lncRNAs play pivotal roles in human cancer. However, the underlying functions and mechanisms of m6A-lncRNA in the physiological processes of breast cancer remain unclear. Here, we found that DSCAM-AS1 is an m6A-modified lncRNA that was overexpressed in breast cancer tissues and cells, indicating poor clinical prognosis. Gain/loss functional assays suggested that DSCAM-AS1 inhibited erastin-induced ferroptosis in breast cancer cells. Mechanistically, there were remarkable m6A modification sites on both the 3'-UTR of DSCAM-AS1 and the endogenous antioxidant factor SLC7A11. M6A methyltransferase methyltransferase-like 3 (METTL3) methylated both SLC7A11 and DSCAM-AS1. Moreover, DSCAM-AS1 recognized m6A sites on the SLC7A11 mRNA, thereby enhancing its stability. Taken together, these findings indicated a potential therapeutic strategy for breast cancer ferroptosis in an m6A-dependent manner.