Triple-negative Breast Cancer Tumor Tissues Research Articles

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.

Sideroflexin-1 promotes progression and sensitivity to lapatinib in triple-negative breast cancer by inhibiting TOLLIP-mediated autophagic degradation of CIP2A

Triple-negative breast cancer (TNBC) is the most aggressive subtype of breast cancer and it lacks specific therapeutic targets and effective treatment protocols. By analyzing a proteomic TNBC dataset, we found significant upregulation of sideroflexin 1 (SFXN1) in tumor tissues. However, the precise function of SFXN1 in TNBC remains unclear. Immunoblotting was performed to determine SFXN1 expression levels. Label-free quantitative proteomics and liquid chromatography-tandem mass spectrometry were used to identify the downstream targets of SFXN1. Mechanistic studies of SFXN1 and cellular inhibitor of PP2A (CIP2A) were performed using immunoblotting, immunofluorescence staining, and reverse transcription-quantitative polymerase chain reaction (RT-qPCR). Functional experiments were used to investigate the role of SFXN1 in TNBC cells. SFXN1 was significantly overexpressed in TNBC tumor tissues and was associated with unfavorable outcomes in patients with TNBC. Functional experiments demonstrated that SFXN1 promoted TNBC growth and metastasis in vitro and in vivo. Mechanistic studies revealed that SFXN1 promoted TNBC progression by inhibiting the autophagy receptor TOLLIP (toll interacting protein)-mediated autophagic degradation of CIP2A. The pro-tumorigenic effect of SFXN1 overexpression was partially prevented by lapatinib-mediated inhibition of the CIP2A/PP2A/p-AKT pathway. These findings may provide a new targeted therapy for patients with TNBC.

TROP2 promotes the proliferation of triple-negative breast cancer cells via calcium ion-dependent ER stress signaling pathway.

To explore the molecular mechanisms of tumor-associated calcium signal transduction factor 2 (TROP2) affecting the occurrence and development of triple-negative breast cancer (TNBC). The TCGA database, immunohistochemical staining, and qRT-PCR were used to analyze the expression of TROP2 in TNBC tissues and cells. The protein expressions of TROP2 and inositol 1,4,5-trisphosphate receptor (IP3R) after TROP2 knockdown were detected by western blot (WB). Cell proliferation was detected by CCK8 and colony formation assay, Annexin V-APC/PI flow cytometry was used to detect apoptosis, and intracellular calcium ion (Ca2+) was detected by flow cytometry with Fura 2-AM fluorescent probe. Finally, the morphological changes of the endoplasmic reticulum (ER) were observed by transmission electron microscopy, and the expression of ER stress (ERS)-related proteins was detected by WB and immunofluorescence staining. TROP2 was up-regulated in TNBC tumor tissues and cells. Silencing TROP2 decreased the proliferation rate and clone formation number, and increased the apoptosis rate and the Ca2+ level in TNBC cells. These phenomena were reversed after the addition of 2-APB. In addition, after TROP2 knockdown, the expressions of IP3R and ERS-related proteins were up-regulated, the ER was cystic dilated, and ERS was activated. And the addition of 2-APB significantly inhibited the activation of ERS induced by TROP2 knockdown. TROP2 regulated the proliferation and apoptosis of TNBC cells through a Ca2+-dependent ERS signaling pathway.

YB-1 Targeted by miR-509-3-5p Affects Migration and Invasion of Triple‑Negative Breast Cancer by Regulating Cellular Epithelial‑Mesenchymal Transition.

The epithelial-mesenchymal transition (EMT) process is closely linked to metastasis of breast cancer. This article elucidates the role of Y-box binding protein-1 (YB-1) on the migration and invasion of triple-negative breast cancer (TNBC) cells by regulating EMT, and the related mechanism. The expression data of YB-1 and miR-509-3-5p in TNBC samples and normal samples were downloaded from the GEO database. The proliferation, migration, invasion, and EMT of TNBC cells were detected by CCK-8 assay, colony formation assay, wound-healing assay, transwell assay, and immunoblotting analyses. The targeted binding of YB-1 and miR-509-3-5p was validated by luciferase reporter experiment. A xenograft mouse model was constructed to investigate the influence of the miR-509-3-5p/YB-1 axis on TNBC tumor growth in vivo. YB-1 was overexpressed, while miR-509-3-5p was underexpressed in TNBC tumor tissues and various cell lines. Silencing YB-1 depressed cell viability, proliferation, motility, and EMT in vitro, and miR-509-3-5p upregulation exerted the same effects. YB-1 was targeted by miR-509-3-5p. The suppressive effects on the phenotypes of TNBC cells caused by overexpressed miR-509-3-5p were attenuated by YB-1 upregulation. In addition, miR-509-3-5p overexpression restrained TNBC tumor growth and downregulated the YB-1-mediated EMT process in vivo. YB-1 targeted by miR-509-3-5p affects motility of TNBC cells by regulating cellular EMT.

Therapeutic dosing and targeting efficacy of Pt-Mal-LHRH towards triple negative breast cancer.

Pt-Mal-LHRH is a newly synthesized chemotherapeutic agent that was designed to selectively target the luteinizing hormone-releasing hormone (LHRH) receptor expressed by triple negative breast cancer (TNBC). The aim of this study was to evaluate the therapeutic dosing, tumor reduction efficacy, and selective distribution of Pt-Mal-LHRH in-vivo. LHRH tissue expression levels in-vivo were investigated using western blotting and LHRH was found to be increased in reproductive tissues (mammary, ovary, uterus). Further, Pt-Mal-LHRH was found to have increased TNBC tumor tissue platinum accumulation compared to carboplatin by inductively coupled plasma mass spectrometry analysis. The platinum family, compound carboplatin, was selected for comparison due to its similar chemical structure and molar equivalent doses were evaluated. Moreover, in-vivo distribution data indicated selective targeting of Pt-Mal-LHRH by enhanced reproductive tissue accumulation compared to carboplatin. Further, TNBC tumor growth was found to be significantly attenuated by Pt-Mal-LHRH compared to carboplatin in both the 4T1 and MDA-MB-231 tumor models. There was a significant reduction in tumor volume in the 4T1 tumor across Pt-Mal-LHRH doses (2.5-20 mg/kg/wk) and in the MDA-MB-231 tumor at the dose of 10 mg/kg/wk in models conducted by an independent contract testing laboratory. Our data indicates Pt-Mal-LHRH is a targeting chemotherapeutic agent towards the LHRH receptor and reduces TNBC tumor growth in-vivo. This study supports drug conjugation design models using the LHRH hormone for chemotherapeutic delivery as Pt-Mal-LHRH was found to be a more selective and efficacious than carboplatin. Further examination of Pt-Mal-LHRH is warranted for its clinical use in TNBCs, along with, other reproductive cancers overexpressing the LHRH receptor.

The Therapeutic Effects of MUC1-C shRNA@Fe3O4 Magnetic Nanoparticles in Alternating Magnetic Fields on Triple-Negative Breast Cancer.

Improving the treatment of triple-negative breast cancer (TNBC) is a serious challenge today. The primary objective of this study was to construct MUC1-C shRNA@ Fe3O4 magnetic nanoparticles (MNPs) and investigate their potential therapeutic benefits in alternating magnetic fields (AMF) on TNBC. Firstly, we verified the high expression of MUC1 in TNBC and synthesized specific MUC1-C shRNA plasmids (MUC1-C shRNA). Then, we prepared and characterized MUC1-C shRNA@Fe3O4 MNPs and confirmed their MUC1-C gene silencing effect and magneto-thermal conversion ability in AMF. Moreover, the inhibitory effects on TNBC in vitro and in vivo were observed as well as biosafety. Finally, the protein levels of BCL-2-associated X protein (Bax), cleaved-caspase3, glutathione peroxidase inhibitor 4 (GPX4), nuclear factor erythroid 2-related factor 2 (NRF2), and ferritin heavy chain 1 (FTH1) in TNBC cells and tissues were examined, and it was speculated that apoptosis and ferroptosis were involved in the synergistic treatment. MUC1-C shRNA@ Fe3O4 MNPs have a size of ~75 nm, with an encapsulation rate of (29.78±0.63) %, showing excellent gene therapy and magnetic hyperthermia functions. Under a constant AMF (3Kw) and a set concentration (200µg mL-1), the nanoparticles could be rapidly warmed up within 20 minutes and stabilized at about 43 °C. It could be uptaken by TNBC cells through endocytosis and significantly inhibit their proliferation and migration, with a growth inhibition rate of 79.22% for TNBC tumors. After treatment, GPX4, NRF2, and FTH1 expression levels in TNBC cells and tumor tissues were suppressed, while Bax and cleaved-caspase3 were increased. As key therapeutic measures, gene therapy, and magnetic hyperthermia have shown a synergistic effect in this treatment strategy, with a combined index (q index) of 1.23. In conclusion, we developed MUC1-C shRNA@Fe3O4 MNPs with magnetic hyperthermia and gene therapy functions, which have shown satisfactory therapeutic effects on TNBC without significant side effects. This study provides a potential option for the precision treatment of TNBC.

Scutellarin suppresses the metastasis of triple-negative breast cancer via targeting TNFα/TNFR2-RUNX1-triggered G-CSF expression in endothelial cells

Triple-negative breast cancer (TNBC) is heterogeneous and aggressive, with high vascularity and frequent metastasis. We have already found natural flavonoid scutellarin (SC) suppressed spontaneous TNBC metastasis via normalizing tumor vasculature in vivo. In this study, supernatant from tumor necrosis factorα (TNFα)-treated human mammary microvascular endothelial cell (HMMEC) promoted cell migration and pseudopod formation in TNBC cells, but these phenomena were disappeared in SC-co-treated HMMEC. TNFα enhanced the expression of granulocyte colony-stimulating factor (G-CSF) and granulocyte–macrophage colony-stimulating factor (GM-CSF) in both HMMEC and human umbilical vein endothelial cell (HUVEC). G-CSF promoted TNBC migration and invasion in vitro, while G-CSF neutralization antibody and SC both inhibited TNBC metastasis in Balb/c mice. SC had no inhibition on the G-CSF-induced TNBC cell migration, but reduced G-CSF content in TNBC tumor tissues and TNFα-stimulated endothelial cells (ECs). SC restricted the nuclear translocation of runt-related transcription factor 1 (RUNX1) in TNBC tumor vessels and TNFα-treated ECs. RUNX1 was found to directly bind to the promoter of G-CSF in TNBC tumor vessels and regulated G-CSF expression. TNF receptor 2 (TNFR2) was crucial for regulating the TNFα-induced RUNX1 activation and G-CSF expression. Notably, SC hindered the interaction between TNFα and TNFR2 via binding to TNFR2. This work demonstrated that SC reduced TNBC metastasis by targeting TNFα/TNFR2-initiated RUNX1 activation and subsequent G-CSF production in TNBC-associated ECs.

Design of Mitoxantrone‐Loaded Biomimetic Nanocarrier with Sequential Photothermal/Photodynamic/Chemotherapy Effect for Synergized Immunotherapy

AbstractMetastatic triple‐negative breast cancer (TNBC) has a poor prognosis and high mortality with no effective treatment options, and immunotherapy is highly anticipated as a potential treatment but is limited by the lack of tumor‐infiltrating T lymphocytes in TNBC. Herein, red blood cell (RBC) membrane‐camouflaged polyphosphoester (PPE) nanoparticles (RBC@PPEMTO/PFA) are prepared as the nanocarriers of mitoxantrone (MTO) and perfluoroalkane (PFA) for synergized immunotherapy. The encapsulated MTO can generate heat and reactive oxygen species (ROS) to achieve photothermal and photodynamic therapy; moreover, ROS further triggers the self‐accelerating release of MTO from the ROS‐sensitive PPE core to enable chemotherapy. The RBC@PPEMTO/PFA‐mediated sequential photothermal/photodynamic/chemotherapy efficiently promotes the infiltration of CD8+ T cells into TNBC tumor tissue and synergizes the therapeutic activity of an immune checkpoint blockade antibody for metastatic TNBC treatment in distant and lung metastasis models. This biomimetic nanomedicine of MTO provides a convenient and available strategy to sensitize TNBC to immune checkpoint blockade antibody.

The function of long non-coding RNA SNHG11 and its working mechanism in triple-negative breast cancer

Triple-negative breast cancer (TNBC) seriously affects woman’s health. The present work is to study the working mechanism of lncRNA SNHG11 in TNBC. The expressions of SNHG11, microRNA (miR)− 7–5p, specificity protein 2 (SP2) and mucin 1 (MUC-1) in TNBC tissues and cells were detected. SNHG11, miR-7–5p and SP2 expressions were then evaluated for TNBC cell malignant behaviors. The relationships among SNHG11, miR-7–5p and SP2 were predicted and verified. Finally, the binding of the transcription factor SP2 to MUC-1 promoter was detected. Abnormally elevated SNHG11, SP2 and MUC-1 expressions were observed in cultured TNBC cells and tumor tissues. SNHG11 knockdown in TNBC cells. Silencing SP2 weakened the promoting effect of SNHG11 on TNBC progression. SNHG11 negatively regulated miR-7–5p expression and positively regulated SP2 expression. SP2 bound to the P2 site of MUC-1 promoter, and SP2 knockdown suppressed MUC-1 expression. It was demonstrated that lncRNA SNHG11 promoted TNBC cell malignant behaviors to facilitate TNBC progression. The study is first of its kinds to unravel the potential of lncRNA SNHG11 in relation to TNBC.

Abstract P6-14-11: Exosome-mediated Circ-CRSP1 promotes tumor proliferation and metastasis through stabilizing ELAVL1 protein and suppresses anti-tumor immune response in regulating the progression of Triple-Negative Breast Cancer

Abstract Background: Triple-negative breast cancer (TNBC) is one of the most malignant subtype of breast cancer. Lacking targetable molecular drivers, chemotherapy is almost the only effective systematic treatment for TNBC. Compared with other types of breast cancer, TNBC shows a higher long-term recurrence rate and worse prognostic outcome, and its main cause of death is tumor metastasis. Therefore, there is an urgent clinical need to explore underlying molecular mechanisms and find novel targets for therapeutic intervention, as well as biomarkers for early clinical diagnosis. Materials & Methods: To explore the signal pathways and target molecules related to tumor immunity by bioinformatics analysis of tissue samples [TNBC (n = 55), Her2 (n = 39), Luminal B (n = 30), Luminal A (n = 29), healthy (n = 11)]. Co-culture experiment was conducted to study the effect of TNBC-derived exosome-mediated molecules on the proliferation and migration of breast cancer. qRT-PCR assay was used to confirm the expression level of Circ-CRSP1 in tumor tissues, breast cancer cells, exosomes of breast cancer cells and serum exosomes of breast cancer patients. Overexpression and knockout experiments investigated the role of Circ-CRSP1 in promoting the proliferation and migration of TNBC cells. Protein molecular docking technique was used to predict the possible targeting binding protein ELAVL1, and molecular experiments and nude mice model were used to study the mechanism of Circ-CRSP1-ELAVL1 complex in tumor immunity. Results: TNBC-derived exosome-mediated molecular transmission promotes the proliferation and migration of breast cancer, and may promote distant metastasis of breast cancer by changing the tumor microenvironment (TME) before metastasis. Bioinformatics analysis of TNBC tumor samples confirmed that TNBC is strongly associated with tumor immune-related biological processes and signal pathways. Circ-CRSP1 is highly expressed in TNBC tumor tissues, TNBC cells, exosome derived from TNBC cells and serum exosomes of TNBC patients, and is related to the poor clinical prognosis of TNBC patients. Overexpression of Circ-CRSP1 enhanced the proliferation and migration ability of TNBC cells, and the expression levels of EMT and cell-cycle related genes altered. Circ-CRSP1 binds to protein ELAVL1 at the physical level. The target gene of Circ-CRSP1-ELAVL1 complex is involved in the immune response, and the overexpression of Circ-CRSP1 significantly down-regulates the expression level of immune-related genes. Conclusion: Exosome-mediated Circ-CRSP1 promotes the transport of ELAVL1 from nucleus to cytoplasm through targeted binding with ELAVL1, and then regulates cytoplasmic proliferation and metastasis and inhibits the stability and translation of anti-tumor immune-related gene mRNA, thus finally promotes the proliferation, invasion and metastasis of TNBC. This study can further understand the mechanism of circRNA in the growth and metastasis of TNBC from the theoretical level, further explore the feasibility of Circ-CRSP1 as a molecular target for gene therapy, and provide theoretical basis and pre-clinical data for Circ-CRSP1 in serum exosomes as a high risk screening index and prognostic marker for TNBC patients. Citation Format: Sujin Yang, Jinhai Tang. Exosome-mediated Circ-CRSP1 promotes tumor proliferation and metastasis through stabilizing ELAVL1 protein and suppresses anti-tumor immune response in regulating the progression of Triple-Negative Breast Cancer. [abstract]. In: Proceedings of the 2022 San Antonio Breast Cancer Symposium; 2022 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2023;83(5 Suppl):Abstract nr P6-14-11.

MiR-526b targets lncRNA SLC16A1-AS1 to suppress cell proliferation in triple-negative breast cancer.

The present study investigated the potential interaction between miR-526b and lncRNA SLC16A1-AS1 in triple-negative breast cancer (TNBC).Expression of miR-526b and SLC16A1-AS1 in TNBC tumor tissues and paired nontumor tissues from 60 TNBC patients was detected by real-time polymerase chain reaction (RT-qPCR). The interaction between miR-526b and SLC16A1-AS1 was evaluated with overexpression experiments, followed by RT-qPCR. The proliferation and migration of cells were detected with cell counting kit-8 assay and Transwell assay, respectively. Apoptosis of cells was assessed by cell apoptosis assay. The expression of apoptosis-related proteins was quantified by Western blot analysis.MiR-526b was predicted to bind with SLC16A1-AS1. Overexpression of miR-526b in TNBC cells decreased the expression levels of SLC16A1-AS1, while overexpression of SLC16A1-AS1 did not affect the expression of miR-526b. In TNBC tissues, miR-526b was downregulated in TNBC tissues, while SLC16A1-AS1 was upregulated in TNBC tissues compared to that in nontumor tissues. The expression of SLC16A1-AS1 and miR-526b were inversely correlated. In vitro experiments showed that overexpression of SLC16A1-AS1 promoted cell proliferation and invasion but suppressed cell apoptosis. MiR-526b played an opposite role and suppressed the function of SLC16A1-AS1.MiR-526b is downregulated in TNBC and it targets SLC16A1-AS1 to regulate proliferation, apoptosis, and invasion of TNBC cells.

The controllable assembly of Cu nanocluster-based aggregation induced ECL strategy for miRNA detection

Copper nanoclusters (Cu NCs) were a new class of non-toxic and economical nanoprobe. However, the low luminescence performance and instability of Cu NCs limited the actual application. Herein, this work developed the novel controllable assembly of Cu NCs aggregation as the electrochemiluminescence (ECL) emitter. Firstly, the hydrophilic Cu NCs was located into the micelles in the reverse microemulsion system. Due to the uniform size of micelles, the number of Cu NCs in each micelle can be controlled exactly. Cerium ions were added to induce Cu NCs to accumulate in micelles. The strong aggregation induced ECL (AIECL) signal can be observed in the controllable assembly of Cu NCs aggregation. The nano-sized Cu NCs assembly not only possessed more strong luminescence and better stability than original Cu NCs, but also kept the good dispersibility over the aggregated bulk. Furthermore, SnS2 nanosheets increased the specific surface area of the electrode and the number of reactive sites, which further modulated electron transfer to amplify the ECL signal. The ECL sensing system was used to detect miRNA-455–3p in the triple-negative breast cancer tumor tissues. The work provided the new pathway to prepare Cu NCs assembly and expanded AIECL-based sensing application.

Chondroitin Sulfate Targeting Nanodrug Achieves Near-Infrared Fluorescence-Guided Chemotherapy Against Triple-Negative Breast Primary and Lung Metastatic Cancer.

Lack of highly expressed tumor target and ligands limits application of nano-medicine against triple-negative breast cancer (TNBC). Previous study reported that placenta-derived oncofetal chondroitin sulfate glycosaminoglycan chain (CSA) expressed on 90% of stage I-III invasive ductal breast carcinomas. Our study found the CSA anchor protein VAR2CSA derived small peptide plCSA had strong binding activity with TNBC cell lines and tumor tissue. Here, we combined the AIEgens TBZ-DPNA and therapy drug paclitaxel (PTX) to fabricate near-infrared fluorescence-guided nanodrug (plCSA-NP) to investigate its targeting and anti-tumor effect on TNBC. We synthesized and purified TBZ-DPNA with one step, measured optical properties and photoluminescence (PL) spectra. We prepared nanodrug plCSA-NP by encapsulating TBZ-DPNA and PTX and conjugating them with peptide plCSA. We evaluated plCSA-NP targeting activity by examining AIEdots fluorescence signal on TNBC cell lines and subcutaneous and lung metastatic mouse model. We assessed PTX delivery effect by cytotoxicity assay on TNBC line and tumor growth of subcutaneous and lung metastatic mouse models. PL spectra and TEM imaging results showed plCSA-NP had maximum emission feature at 718 nm and nearly monodispersed nanosphere with an average diameter of 70 nm. In vitro studies showed plCSA-NPs had high affinity and cytotoxicity with TNBC cell lines. In vivo subcutaneous and lung metastasis mouse studies showed plCSA-NPs accumulated on TNBC tumor tissue, and significantly prevented TNBC subcutaneous and lung metastasis tumor growth. In conclusion, we provide solid evidence for chondroitin sulfate targeting peptide plCSA guided nanodrug, exhibit good targeting efficiency and therapeutic effect against TNBC primary and lung metastatic tumor growth.

Silencing of COL3A1 represses proliferation, migration, invasion, and immune escape of triple negative breast cancer cells via down-regulating PD-L1 expression.

This study is designed to illuminate the specific role and underlying mechanism of collagen type III alpha 1 chain (COL3A1) in triple negative breast cancer (TNBC). Quantitative real-time polymerase chain reactionwas applied to examine mRNA expression of COL3A1. Western blot analysis was employed to determine protein levels of COL3A1, programmed death ligand 1 (PD-L1),Bcl-2, and cleaved caspase-3. Immunohistochemistry staining was utilized for assessing protein expression of Ki67 and COL3A1 in tissues. The proliferous capacity of cells was assessed through CCK-8 assay and 5-Ethynyl-2'-deoxyuridine assay. Cell apoptosis and the percentage of CD8+ T cells were measured using flow cytometry. Migration and invasion of TNBC cells were examined via transwell assay. Lactate dehydrogenase (LDH)release was measured via a LDH assay kit. For establishing a xenograft tumor model, MDA-MB-231 cells were injected into the flank of mice through subcutaneous injection. COL3A1 expression was raised in TNBC tissues and cells, and it was inversely associated with overall survival data of TNBC patients. COL3A1 downregulation repressed proliferation, invasion, migration, and immune escape of TNBC cells along with tumor growth of xenograft mice. In TNBC cells and tumor tissues of mice, protein expression of PD-L1 was reduced by COL3A1 knockdown. COL3A1 knockdown-mediated inhibitory effects on cell proliferation, migration, invasion, and immune escape were reversed by PD-L1 upregulation in vitro. Silencing of COL3A1 exerted an antitumor role in TNBC, implying its potential as a therapeutic target for TNBC.

Confined Gold Single Atoms-MXene Heterostructure-Based Electrochemiluminescence Functional Material and Its Sensing Application.

Herein, based on electronic metal-support interaction (EMSI), a gold single atom confined MXene (AuSA/MXene) heterostructure was developed as the highly efficient electrochemiluminescence (ECL) functional material, which greatly improved the electrochemical properties and broadened the sensing application of MXenes. Gold single atoms were confined into the vacancy defects of Ti3C2Tx MXene, which could effectively avoid the masking of catalytic active sites. Meanwhile, electron transport could be accelerated with the assistance of titanium dioxide on the MXene nanosheets. Therefore, the AuSA/MXene heterostructure had high catalytic activity and electrical activity to promote hydrogen peroxide to generate free radicals, which achieved high-efficiency ECL. Eventually, the AuSA/MXene heterostructure was used to construct a Faraday cage-type ECL sensor with fluid nanoislands to detect miRNA-187 in triple-negative breast cancer tumor tissues.

A novel GSH-capping MXene QD-based ECL biosensor for the detection of miRNA221 in triple-negative breast cancer tumor

In this work, we have constructed a novel electrochemiluminescence (ECL) biosensor for the detection of miRNA221 based on glutathione-capped MXene-derived quantum dots (GSH-MQDs) and magnetic biomimic vesicles. Glutathione is used as precursor in the synthesis of MXene-derived QDs, which effectively improves the oxidation resistance of MXene. In the sensing system, GSH-MQDs still possess the advantages of MXene, including the excellent electrical conductivity and good electrochemical activity. The combination of the metal atoms on the MXene and the sulfhydryl group of GSH further reduce the defects in nanostructures of MXene-derived QDs. As a result, the stability and the luminescent properties of GSH-MQDs as ECL emitter have been significantly improved. Furthermore, magnetic biomimic vesicles are prepared as sensing platform to improve the feasibility and sensitivity for the miRNA221 detection. Moreover, a sensing strategy for miRNA221 detection is designed based on the cyclic amplification with T7 exonuclease. The biosensor is used to detect miRNA221 in the triple-negative breast cancer tumor tissues. The satisfactory results have indicated that this sensing strategy on the basis of GSH-MQD and magnetic biomimic vesicles possesses great potential for clinical analysis.

Fatty acid oxidation protects cancer cells from apoptosis by increasing mitochondrial membrane lipids.

Overcoming resistance to chemotherapies remains a major unmet need for cancers, such as triple-negative breast cancer (TNBC). Therefore, mechanistic studies to provide insight for drug development are urgently needed to overcome TNBC therapy resistance. Recently, an important role of fatty acid β-oxidation (FAO) in chemoresistance has been shown. But how FAO might mitigate tumor cell apoptosis by chemotherapy is unclear. Here, we show that elevated FAO activates STAT3 by acetylation via elevated acetyl-coenzyme A (CoA). Acetylated STAT3 upregulates expression of long-chain acyl-CoA synthetase 4 (ACSL4), resulting in increased phospholipid synthesis. Elevating phospholipids in mitochondrial membranes leads to heightened mitochondrial integrity, which in turn overcomes chemotherapy-induced tumor cell apoptosis. Conversely, in both cultured tumor cells and xenograft tumors, enhanced cancer cell apoptosis by inhibiting ASCL4 or specifically targeting acetylated-STAT3 is associated with a reduction in phospholipids within mitochondrial membranes. This study demonstrates a critical mechanism underlying tumor cell chemoresistance.

Molecular and Immune Correlates of PDCD1 (PD-1), PD-L1 (CD274), and PD-L2 (PDCD1LG2) DNA Methylation in Triple Negative Breast Cancer.

Immune checkpoints are important targets in oncological therapy. Recent studies have proven efficacy of immune checkpoint inhibition (ICI) in treatment of triple negative breast cancer (TNBC). However, only a proportion of TNBC-patients benefit from ICI. Thus, current scientific efforts in this context are focused on the identification of a robust biomarker that enables patient stratification. In the present study, we investigated the epigenetic regulation of PD-1 (PDCD1), PD-L1 (CD274), and PD-L2 (PDCD1LG2). Methylation data of PD-1, PD-L1, and PD-L2, and complex immunogenomic data were obtained from The Cancer Genome Atlas (TCGA). Methylation were systematically analyzed with regard to the transcriptional activity of the studied immune checkpoint genes and the tumor microenvironment. We found differential methylation of PD-1, PD-L1, and PD-L2 in normal adjacent tissue and TNBC tumor tissue. In the TNBC-TCGA cohort, methylation status of PD-1, PD-L1, and PD-L2 were significantly correlated with mRNA levels indicating a strong epigenetic regulation of the transcriptional activity. Moreover, PD-1, PD-L1, and PD-L2 methylation status was strongly associated with a distinct immune cell infiltration pattern. Our results indicate an epigenetic regulation of immune checkpoint genes through DNA methylation in TNBC. In addition, the methylation status was associated with a distinct composition of the tumor microenvironment. Overall, this provides a strong rationale for assessing the value of PD-1, PD-L1, and PD-L2 DNA methylation to predict response to ICI and immunogenicity in TNBC.

The lncRNA ADAMTS9-AS2 Regulates RPL22 to Modulate TNBC Progression via Controlling the TGF-β Signaling Pathway

BackgroundLong non-coding RNAs (lncRNAs) are key regulators of triple-negative breast cancer (TNBC) progression, but further work is needed to fully understand the functional relevance of these non-coding RNAs in this cancer type. Herein, we explored the functional role of the lncRNA ADAMTS9-AS2 in TNBC.MethodsNext-generation sequencing was conducted to compare the expression of different lncRNAs in TNBC tumor and paracancerous tissues, after which ADAMTS9-AS2differential expression in these tumor tissues was evaluated via qPCR. The functional role of this lncRNA was assessed by overexpressing it in vitro and in vivo. FISH and PCR were used to assess the localization of ADAMTS9-AS2within cells. Downstream targets of ADAMTS9-AS2 signaling were identified via RNA pulldown assays and transcriptomic sequencing.ResultsThe expression ofADAMTS9-AS2 was decreased in TNBC tumor samples (P < 0.05), with such downregulation being correlated with TNM stage, age, and tumor size. Overexpressing ADAMTS9-AS2 promoted the apoptotic death and cell cycle arrest of tumor cells in vitro and inhibited tumor growth in vivo. From a mechanistic perspective, ADAMTS9-AS2 was found to control the expression of RPL22 and to thereby modulate TGF-β signaling to control TNBC progression.ConclusionADAMTS9-AS2 controls the expression of RPL22 and thereby regulates TNBC malignancy via the TGF-β signaling pathway.

Prognostic values of spindle checkpoint protein BUB1B in triple negative breast cancer

Objective: To identify important prognostic molecular markers of triple negative breast cancer (TNBC) using high throughput sequencing technology and to explore the correlation of spindle checkpoint protein BUB1B and clinicopathological features with patients' prognosis. Methods: The clinicopathological data and prognostic information of TNBC diagnosed at the West China Hospital of Sichuan University from 2009 to 2017 were collected. Forty-seven fresh tumor samples and 139 formalin fixed paraffin-embedded samples were selected. The fresh tumor samples were subject to RNA sequencing (RNA-seq). The enrichment analysis and protein-protein interaction (PPI) analysis were performed after intersection of difference analysis between RNAseq and GEO (Gene Expression Omnibus) datasets GSE38959 and GSE65194. Kaplan-Meier plotter database was used to analyze the relationship between expression of BUB1B and prognosis. Immunohistochemical staining was used to verify its expression in TNBC and correlation with clinicopathological features and prognosis. Results: Using edgeR to perform differential expression analysis between 47 TNBC tumor tissues and 12 normal tissues, 1 559 up-regulated genes and 1 376 down-regulated genes were identified, while only 131 differentially expressed genes were overlapping with those in GSE38959 and GSE65194. Enrichment analysis was mainly enriched in cell cycle, JAK-STAT signaling pathway and p53 signaling pathway. The top 10 genes ranked by degree of association were TOP2A, BUB1B, MKI67, PLK1, RRM2, PCNA, KPNA2, SMC4, PBK and IGF1. Kaplan-Meier plotter database analysis showed that the expression of BUB1B was significantly correlated with the prognosis of TNBC [overall survival, hazard ratio (HR)=0.52, 95%CI (0.35-0.77), P=0.001; distant metastasis-free, HR=0.72, 95%CI (0.52-0.98), P=0.038]. The immunohistochemical analyses of 139 formalin fixed paraffin-embedded samples showed that the low expression of BUB1B was correlated with poor prognosis in TNBC [HR=0.41, 95%CI (0.18-0.95), P=0.024]. Conclusions: The low expression of BUB1B protein is associated with poor prognosis in TNBC patients, and the molecular mechanism related with prognosis and potential therapeutic targets need to be further studied.