Clinical Value of cfDNA Content in Peripheral Blood of Patients with Triple-Negative Breast Cancer

Objective:To explore the value of circulating free(cfDNA)content in the clinical diagnosis and treatment of triple-negative breast cancer(TNBC).Methods:A total of 39 TNBC patients,45 non-TNBC patients,and 50 healthy individuals admitted to the Baoding First Central Hospital during 2019-2022 were recruited.The clinical data,peripheral blood cfDNA concentration,and clinicopathological indicators of the patients were observed and analyzed.Results:The difference in clinical indicators such as age,age range,tumor size,clinical stage,and lymph node metastasis between patients with TNBC and non-TNBC was insignificant(P>0.05).The cfDNA concentrations(ng/mL)of the TNBC group,non-TNBC group,and healthy group were 24.12±4.98,15.36±4.12,and 3.12±1.02,respectively,and they are statistically different(P<0.05).The difference in cfDNA concentration was insignificant between TNBC patients with tumors≤2 cm and>2 cm(P>0.05)but was significant between TNBC patients with clinical stages I+II and III+IV(P<0.05).The cfDNA concentration in TNBC patients with lymph node metastasis was significantly higher than those without lymph node metastasis(P<0.05).Conclusion:cfDNA has an important application value in the diagnosis and treatment of breast cancer.By detecting the cfDNA level and its gene variation,valuable information about the progress and treatment effects of breast cancer can be obtained.This non-invasive detection method has a wide range of applications and can be used for early screening,auxiliary diagnosis,efficacy evaluation,and recurrence monitoring of breast cancer.

Cancer stem-like cells directly participate in vasculogenic mimicry channels in triple-negative breast cancer

Objective: Vasculogenic mimicry(VM) channels that are lined by tumor cells are a functional blood supply in malignant tumors.However, the role of VM-initiating cells remains poorly understood. Cancer stem-like cells(CSCs) are positively correlated with VM. In this study, triple-negative breast cancer(TNBC) enriched with CSCs was used to investigate the relationship between VM and CSCs.Methods: The expression of several CSC markers was detected by immunohistochemistry in 100 human breast cancer samples.The clinical significance of CSC markers and the relationship between VM, CSCs, breast cancer subtypes, and VM-associated proteins were analyzed. CD133+ and ALDH+ human and mouse TNBC cells were isolated by FACS to examine the ability of VM formation and the spatial relationship between VM and CSCs.Results: CSCs were associated with TNBC subtype and VM in human invasive breast cancer. CSCs in TNBC MDA-MB-231 cells formed more VM channels and expressed more molecules promoting VM than the non-TNBC MCF-7 cells in vitro. MDA-MB-231 cells that encircled VM channels on Matrigel expressed CD133. Moreover, CSCs were located near VM channels in the 3D reconstructed blood supply system in human TNBC grafts. The CD133+ and ALDH+ cells isolated from TA2 mouse breast cancer formed more VM channels in vivo.Conclusions: CSCs line VM channels directly. Additionally, CSCs provide more VM-related molecules to synergize VM formation. The signaling pathways that control CSC differentiation may also be potential treatment targets for TNBC.

Adjuvant treatment for triple-negative breast cancer: a retrospective study of immunotherapy with autologous cytokine-induced killer cells in 294 patients

Objective: To examine the efficacy and safety of a sequential combination of chemotherapy and autologous cytokine-induced killer(CIK) cell treatment in triple-negative breast cancer(TNBC) patients.Methods: A total of 294 post-surgery TNBC patients participated in the research from January 1, 2009 to January 1, 2015. After adjuvant chemotherapy, autologous CIK cells were introduced in 147 cases(CIK group), while adjuvant chemotherapy alone was used to treat the remaining 147 cases(control group). The major endpoints of the investigation were the disease-free survival(DFS) and overall survival(OS). Additionally, the side effects of the treatment were evaluated.Results: In the CIK group, the DFS and OS intervals of the patients were significantly longer than those of the control group(DFS:P = 0.047;OS: P = 0.007). The multivariate analysis demonstrated that the TNM(tumor-node-metastasis) stage and adjuvant CIK treatment were independent prognostic factors for both DFS [hazard ratio(HR)= 0.520, 95% confidence interval(CI):0.271-0.998, P = 0.049;HR = 1.449, 95% CI:1.118-1.877, P = 0.005, respectively] and OS(HR=0.414, 95% CI:0.190-0.903, P = 0.027;HR= 1.581, 95% CI:1.204-2.077, P = 0.001, respectively) in patients with TNBC. Additionally, longer DFS and OS intervals were associated with increased number of CIK treatment cycles(DFS: P = 0.020;OS: P = 0.040). The majority of the patients who benefitted from CIK cell therapy were relatively early-stage TNBC patients.Conclusion: Chemotherapy in combination with adjuvant CIK could be used to lower the relapse and metastasis rate, thus effectively extending the survival time of TNBC patients, especially those at early stages.

Ultra-sensitive Nanoprobe Modified with Tumor Cell Membrane for UCL/MRI/PET Multimodality Precise Imaging of Triple-Negative Breast Cancer

Triple-negative breast cancer(TNBC)is a subtype of breast cancer in which the estrogen receptor and progesterone receptor are not expressed,and human epidermal growth factor receptor 2 is not amplified or overexpressed either,which make the clinical diagnosis and treatment very challenging.Molecular imaging can provide an effective way to diagnose TNBC.Upconversion nanoparticles(UCNPs),are a promising new generation of molecular imaging probes.However,UCNPs still need to be improved for tumor-targeting ability and biocompatibility.This study describes a novel probe based on cancer cell membrane-coated upconversion nanoparticles(CCm-UCNPs),owing to the low immunogenicity and homologous-targeting ability of cancer cell membranes,and modified multifunctional UCNPs.This probe exhibits excellent performance in breast cancer molecular classification and TNBC diagnosis through UCL/MRI/PET tri-modality imaging in vivo.By using this probe,MDA-MB-231 was successfully differentiated between MCF-7 tumor models in vivo.Based on the tumor imaging and molecular classification results,the probe is also expected to be modified for drug delivery in the future,contributing to the treatment of TNBC.The combination of nanoparticles with biomimetic cell membranes has the potential for multiple clinical applications.

Meclizine Chloridrate and Methyl-β-Cyclodextrin Associated with Monophosphoester Synthetic Phosphoethanolamine Modulating Proliferative Potential in Triple-Negative Breast Cancer Cells

Synthetic phosphoethanolamine(Pho-s)is a monophosphoester ester with anti-inflammatory and pro-apoptotic properties.Meclizine chloridrate(MC)is a histamine H1 receptor blocker that is also able to inhibit cellular respiration.However,MC does not inhibit cellular respiration in isolated mitochondria such as antimycin and rotenone.Methyl-β-cyclodextrin(MβCD)belongs to theβ-cyclodextrin family,which is capable of removing cholesterol from the plasma membrane.The aim of this study was to evaluate the proliferative effects of meclizine chloridrate and methyl-β-cyclodextrin compounds associated with synthetic phosphoethanolamine in a triple-negative human breast tumor line,MDA-MB-231 Cell viability of the tumor line and normal cells FN1 was evaluated by MTT colorimetric test;the production of free radicals was determined by lipoperoxidation(LPO)test;and the percentage of cell cycle phases and proliferative index was evaluated by flow cytometry.Cell viability demonstrated a significant decrease with the treatments of MβCD,MC and Pho-s associated with MC.The production of free radicals decreases significantly in all treatments.In addition,a significant increase of DNA fragment and decrease in G0/G1 cell cycle phase were observed in cellular percentage with concentrations of 20 and 30 mM of Pho-s in association with MC and MβCD,respectively.

Clinical Value of Peripheral Blood Circulating Tumor Cells and Cell-Free DNA Combined Detection in Triple-Negative Breast Cancer

Objective:To determine the clinical value of combined detection of circulating tumor cells(CTCs)and cell-free DNA(cfDNA)in peripheral blood of patients with triple-negative breast cancer.Method:41 patients with breast cancer admitted to the First Central Hospital of Baoding from January 2020 to December 2021 were selected and recruited into the experimental group,42 patients with benign breast cancer admitted during the same period were recruited into the conditional control group,and 41 healthy patients admitted during the same period were recruited into the blank control group.The positive rate of peripheral blood CTCs,the level of cfDNA,and the diagnostic efficacy of peripheral blood CTCs,cfDNA alone and the combination thereof for breast cancer were analyzed.Result:The positive rates of peripheral blood CTCs in the experimental group,the conditional control group,and the blank control group were 43.90%,11.90%,and 9.74%,respectively,and there was significant difference among the groups.The levels of cfDNA in peripheral blood of the experimental group,the conditional control group,and the blank control group were 0.26±0.08 bp,0.17±0.03 bp,and 0.15±0.04 bp,respectively,which were statistically significant.The detection levels of 100 bp hTERT/ng mT1 and 241 bp hTERT/ng-mT1 in the experimental group were significantly higher than those in the conditional control group and the blank control group.The accuracy of peripheral blood CTCs detection in the three groups was 66.21%,the accuracy of cfDA241 bp/100 hp hTERT detection was 80.41%,and the accuracy of combined detection of peripheral blood CTCs and cfDNA was 94.03%.Conclusion:The clinical application of peripheral blood CTCs combined with cfDNA level detection can increase detection accuracy,provide data support for clinicians,and improve the clinical diagnostic effect of triple-negative breast cancer.

Identification of a seven-gene signature and establishment of a prognostic nomogram predicting overall survival of triple-negative breast

Background: Triple-negative breast cancer (TNBC) is a highly heterogeneous breast cancersubtype characterized by the absence of expression of estrogen receptor (ER), progesteronereceptor (PR), and human epidermal growth factor receptor 2 (HER2). TNBC exhibitsresistance to hormone and HER2-targeted therapy, along with a higher incidence ofrecurrence and poorer prognosis. Therefore, exploring the molecular features of TNBC andconstructing prognostic models are of significant importance for personalized treatmentstrategies. Methods: In this research, bioinformatics approaches were utilized to screendifferentially expressed genes in 405 TNBC cases and 128 normal tissue samples from 8 GEOdatasets. Key core genes and signaling pathways were further identified. Additionally, aprognostic model incorporating seven genes was established using clinical and pathologicalinformation from 169 TNBC cases in the TCGA dataset, and its predictive performance wasevaluated. Results: Functional analysis revealed dysregulated biological processes such asDNA replication, cell cycle, and mitotic chromosome separation in TNBC. Protein-proteininteraction network analysis identified ten core genes, including BUB1, BUB1B, CDK1,CDC20, CDCA8, CCNB1, CCNB2, KIF2C, NDC80, and CENPF. A prognostic model consistingof seven genes (EXO1, SHCBP1, ABRACL, DMD, THRB, DCDC2, and APOD) was establishedusing a step-wise Cox regression analysis. The model demonstrated good predictiveperformance in distinguishing patients' risk. Conclusion: This research provides importantinsights into the molecular characteristics of TNBC and establishes a reliable prognosticmodel for understanding its pathogenesis and predicting prognosis. These findingscontribute to the advancement of personalized treatment for TNBC.

Metabolic reprogramming in triple-negative breast cancer

Since triple-negative breast cancer(TNBC)was first defined over a decade ago,increasing studies have focused on its genetic and molecular characteristics.Patients diagnosed with TNBC,compared to those diagnosed with other breast cancer subtypes,have relatively poor outcomes due to high tumor aggressiveness and lack of targeted treatment.Metabolic reprogramming,an emerging hallmark of cancer,is hijacked by TNBC to fulfill bioenergetic and biosynthetic demands;maintain the redox balance;and further promote oncogenic signaling,cell proliferation,and metastasis.Understanding the mechanisms of metabolic remodeling may guide the design of metabolic strategies for the effective intervention of TNBC.Here,we review the metabolic reprogramming of glycolysis,oxidative phosphorylation,amino acid metabolism,lipid metabolism,and other branched pathways in TNBC and explore opportunities for new biomarkers,imaging modalities,and metabolically targeted therapies.

Methanolic extract of Abrus precatorius promotes breast cancer MDA-MB-231 cell death by inducing cell cycle arrest at G0/G1 and upregulating Bax

Objective:To determine the anti-proliferative activity of Abrus precatorius(A.precatorius)leaf extracts and their effect on cell death.Methods:A.precatorius leaves were extracted successively with hexane,ethyl acetate and methanol by Soxhlet extraction.Aqueous extract was prepared by decoction at 50 ℃.Extracts of A.precatorius leaves were used to treat selected cancer and normal cell lines for72 h.Furthermore,3-(4,5-dimethyl thiazol-2-yl)2,5-diphenyl tetrazolium bromide assay was performed to determine cell viability.Analysis of cell cycle arrest,apoptosis assay and apoptosis protein expressions were determined by flow cytometry.Results:Methanolic extract of A.precatorius leaves showed the lowest IC50 on MDA-MB-231 cells at(26.40±5.40)μg/mL.Flow cytometry analysis revealed that cell arrest occurred at G0/G1 phase and the apoptosis assay showed the occurrence of early apoptosis at 48 h in MDAMB-231 cells treated with methanolic extract of A.precatorius leaves.Methanolic extract of A.precatorius leaves induced apoptosis by upregulation of Bax,p53 and caspase-3 and downregulation of Bcl-2.Conclusions:Methanolic extract of A precatorius leaves promotes MDA-MB-231 cell death by inducing cell cycle arrest and apoptosis possibly via the mitochondrial-related pathway.

The cancer-testis gene,MEIOB,sensitizes triple-negative breast cancer to PARP1 inhibitors by inducing homologous recombination deficiency

Objective:The newly defined cancer-testis(CT)gene,MEIOB,was previously found to play key roles in DNA double-strand break(DSB)repair.In this study,we aimed to investigate the effects and mechanisms of MEIOB in the carcinogenesis of triple-negative breast cancers(TNBCs).Methods:The Cancer Genome Atlas database was used to quantify the expression of MEIOB.Cox regression analysis was used to evaluate the association between MEIOB expression and the prognosis of human TNBC.The effects of MEIOB on cell proliferation and migration in TNBCs were also assessed in vitro.Patient-derived xenograft(PDX)models were used to assess the sensitivity of breast cancers with active MEIOB to PARP1 inhibitors.Results:We confirmed MEIOB as a CT gene whose expression was restricted to the testes and breast tumors,especially TNBCs.Its activation was significantly associated with poor survival in breast cancer patients[overall,hazard ratio(HR)=1.90(1.16–2.06);TNBCs:HR=7.05(1.16–41.80)].In addition,we found that MEIOB was oncogenic and significantly promoted the proliferation of TNBC cells.Further analysis showed that MEIOB participated in DSB repair in TNBCs.However,in contrast to its function in meiosis,it mediated homologous recombination deficiency(HRD)through the activation of poly ADP-ribose polymerase(PARP)1 by interacting with YBX1.Furthermore,activated MEIOB was shown to confer sensitivity to PARP inhibitors,which was confirmed in PDX models.Conclusions:MEIOB played an oncogenic role in TNBC through its involvement in HRD.In addition,dysregulation of MEIOB sensitized TNBC cells to PARP inhibitors,so MEIOB may be a therapeutic target of PARP1 inhibitors in TNBC.

Anticancer property of sediment actinomycetes against MCF-7 and MDA-MB-231 cell lines

Objective:To investigate the anticancer property of marine sediment actinomvceles against two different breast cancer cell lines.Methods:In vitro anticancer activity was carried out against breast(MCF-7 and MDA-MB-231)cancer cell lines.Partial sequences of the 16s rRNA gene,phylogenetic tree construction,multiple sequence analysis and secondary structure analysis were also carried out with the actinomycetes isolates.Results:Of the selected five actinomycete isolates,ACT01 and ACT02 showed the IC_(50)value with(10.13±0.92)and(22.34±5.82)μg/mL concentrations,respectively for MCF-7 cell line at 48 h,but ACT01 showed the minimum(18.54±2.49μg/mL)level of IC_(50)value with MDA-MB-231 cell line.Further,the 16s rRNA partial sequences of ACT01,ACT02,ACT03,ACT04 and ACT05 isolates were also deposited in NCBI data bank with the accession numbers of GQ478246,GQ478247,GQ478248,GQ478249 and GQ478250.respectively.The phylogenetic tree analysis showed that,the isolates of ACT02 and ACT03 were represented in groupⅠandⅢ,respectively,but ACT01 and ACT02 were represented in groupⅡ.The multiple sequence alignment of the actinomycete isolates showed that,the maximum identical conserved regions were identified with the nucleotide regions of 125 to 221st base pairs,65 to 119th base pairs and 55,48 and 31st base pairs.Secondary structure prediction of the 16s rRNA showed that,the maximum free energy was consumed with ACT03 isolate(-45.4 kkal/mol)and the minimum free energy was consumed with ACT04 isolate(-57.6 kkal/mol).Conclusions:The actinomycete isolates of ACT01 and ACT02(GQ478246 and GQ478247)which are isolated from sediment sample can be further used as anticancer agents against breast cancer cell lines.

Piperine suppresses growth and migration of human breast cancer cells through attenuation of Rac1 expression

Objective:To investigate the effect of piperine on human breast cancer cells.Methods:The effect of piperine on proliferation and migration of human breast cancer cells,MCF-7 and MDA-MB-231,was investigated using colony formation assays,wound healing assays,Matrigel migration assays,flow cytometry,RT-qPCR,and Western blotting assays.Results:Piperine inhibited the growth of MCF-7 and MDA-MB-231 cells and suppressed colony formation.Cell reduction at the G_(0)/G_(1) phase and cell arrest at the G_(2)/M phase were observed in breast cancer cells.However,the significant effect was only demonstrated in MDA-MB-231 cells.Moreover,cancer cell migration was suppressed by piperine at low concentration.RT-qPCR and Western blotting assays showed that piperine downregulated Rac1 gene and protein expression.Conclusions:Piperine could inhibit growth and migration of breast cancer cells by reducing Rac1 gene and protein expression.

Effect of Guizhi Fuling capsule and its extracts on human breast cancer cells proliferation

OBJECTIVE To evaluate the effect of Guizhi Fuling Capsule active pharmaceutical ingredient(API)and its fractions on human breast cancer cells proliferation by high-throughput screening assay.METHODS The crude fractions were obtained from the extraction and elution of the API of Guizhi Fuling Capsule,and 929 standard fractions were obtained by the optimal separation conditions.Sulforhodamine B(SRB)method was used to evaluate the effects of the Guizhi Fuling capsule API and929 kinds of fractions on the proliferation of human breast cancer cells MCF-7 and MDA-MB-231.RESULTS The Guizhi Fuling capsule API had a strong ability to inhibit the proliferation of MCF-7 cells at high concentration and the ability to inhibit MDA-MB-231 cells' proliferate at low concentration following 72 h treatment;some samples of 929 fractions(5μg·mL^(-1))was found to have a breast cancer cell growth inhibition rate above 50%,without toxicity on HUVECs proliferation.CONCLUSION The API of Guizhi Fuling capsule had significant cytotoxicity effects on these two human breast cancer cells,with significant concentration-and time-dependent manner.

Investigating the effects of Pentoxifylline on human breast cancer cells using Raman spectroscopy

Breast cancer is one of the leading causes of cancer-related deaths in a global scenario.In the present study,biochemical changes exerted upon Pentoxifylline(PTX)treatment had been ap-praised in human breast cancer cells using Raman spectrosecopy.There are no clinically approved methods to monitor such therapeutic responses available.The spectral profiling is suggestive of changes in DNA,protein and lipid contents showing a linear relationship with drug dosage.Further,multivariate analysis using principal component based linear-discriminant-analysis(PC-LDA)was employed for dlassifying the control and the PTX treated groups.These findings support the feasibility of Raman spectroscopy as an alternate/adjunct label-free,objective method for monitoring drug-induced modifications against breast cancer cells.

Sensitivity Evaluation of Two Human Breast Cancer Cell Lines to Tamoxifen through Apoptosis Induction

Tamoxifen citrate (TAM) has been used to treat breast cancer in women for many years. The com-parative effects of TAM in inducing apoptosis were evaluated in estrogen receptor-positive (ER- positive MCF-7) and estrogen receptor-negative (ER-negative MDA-MB-231) human breast cancer cell lines in vitro in order to determine if these two cell lines differ in their sensitivity to TAM. Mi-tochondrial membrane permeability potential disruption was assessed in both cell lines by a lip-ophilic cationic dye (DePsipher assay, Trevigen, Inc.) utilizing fluorescence microscopy. Using this specific fluorochrome, we were able to associate mitochondrial membrane disruption to early, mid-, and late apoptotic cells. TAM induced cell death via apoptosis in both ER-positive and ER- negative cells, however, apoptosis induction was more pronounced in ER-positive MCF-7 compared to ER-negative MDA-MB-231 breast cancer cells. These findings may have some therapeutic use in the treatment of estrogen dependent and estrogen independent breast cancer.

Investigating the Immunogenic Cell Death‑Dependent Subtypes and Prognostic Signature of Triple‑Negative Breast Cancer

Recently,immunotherapy has emerged as a promising and efective method for treating triple-negative breast cancer(TNBC).However,challenges still persist.Immunogenic cell death(ICD)is considered a prospective treatment and potential combinational treatment strategy as it induces an anti-tumor immune response by presenting the antigenic epitopes of dead cells.Nevertheless,the ICD process in TNBC and its impact on disease progression and the response to immunotherapy are not well understood.In this study,we observed dysregulation of the ICD process and verifed the altered expression of prognostic ICD genes in TNBC through quantitative real-time polymerase chain reaction(qRT-PCR)analysis.To investigate the potential role of the ICD process in TNBC progression,we determined the ICD-dependent subtypes,and two were identifed.Analysis of their distinct tumor immune microenvironment(TIME)and cancer hallmark features revealed that Cluster 1 and 2 corresponded to the immune“cold”and“hot”phenotypes,respectively.In addition,we constructed the prognostic signature ICD score of TNBC patients and demonstrated its clinical independence and generalizability.The ICD score could also serve as a potential biomarker for immune checkpoint blockade and may aid in the identifcation of targeted efective agents for individualized clinical strategies.

DNA damage and breast cancer

Cancer is intimately related to the accumulation of DNA damage,and repair failures(including mutation prone repair and hyperactive repair systems).This article relates current clinical categories for breast cancer and their common DNA damage repair defects.Information is included on the potential for accumulation of DNA damage in the breast tissue of a woman during her lifetime and the role of DNA damage in breast cancer development.We then cover endogenous and exogenous sources of DNA damage,types of DNA damage repair and basic signal transduction pathways for three gene products involved in the DNA damage response system;namely BRCA1,BRIT1 and PARP-1.These genes are often considered tumor suppressors because of their roles in DNA damage response and some are under clinical investigation as likely sources for effective new drugs to treat breast cancers.Finally we discuss some of the problems of DNA damage repair systems in cancer and the conundrum of hyper-active repair systems which can introduce mutations and confer a survival advantage to certain types of cancer cells.

Clinicopathological significance of PTEN,Twist1 and PD1^(+)tumor infiltration lymphocytes in triple negative breast cancer

Objective:To study the prognostic features and relationships of PTEN,Twist1 and PD1+tumor infiltration lymphocytes(TILPD1)in triple negative breast cancer(TNBC)by retrospectively analyzing clinicopathological data from patients and immunohistochemical methods.Methods:Formalin-fixed paraffin-embedded(FFPE)specimens of 76 TNBC patients and 46 other subtypes breast cancer patients(NTNBC)were collected in the first affiliated hospital of Bengbu Medical College.These specimen were then immunohistochemically evaluated for expression of PTEN,Twist1 and TILPD1.We also collected clinicopathological features and prognostic data from these patients,who have been followed up regularly through telephone until now.Statistical methods were taken to correlate expression level of different biomarkers and the clinical data.Results:Compared with NTNBC patients,degree of tumor infiltrating lymphocytes and Twist1 expression was higher in TNBC patients.In TNBC tissues,PTEN was negatively correlated with Twist1 and TILPD1 expression,Twist1 was positively correlated with TILPD1 expression,and TILPD1 expression was significantly positively correlated with tumor stromal TIL infiltration(P=0.012,0.031,0.019,0.035).In addition,PTEN was negatively correlated with the clinical stage of tumor(P=0.002),and was also correlated with TIL infiltration,tumor metastasis rate and histological grade.Univariate and multivariate survival analyses showed that patients with lower TNM grade,no lymph node or distant metastasis had better clinical prognosis,while PTEN deficiency and TILPD1 overexpression were independent risk factors of patients with TNBC.Conclusion:Our results suggest that PTEN downregulation and TILPD1 overexpression may predict an unfavorable prognosis for TNBC patients.Thus,these two biomarkers present the potential as two prognostic predictor for TNBC.

Low level of ARID1A contributes to adaptive immune resistance and sensitizes triple-negative breast cancer to immune checkpoint inhibitors

Background Immune checkpoint inhibitors(ICIs)shed new light on triple-negative breast cancer(TNBC),but only a minority of patients demonstrate response.Therefore,adaptive immune resistance(AIR)needs to be further defined to guide the development of ICI regimens.Methods Databases,including The Cancer Genome Atlas,Gene Ontology Resource,University of California Santa Cruz Genome Browser,and Pubmed,were used to screen epigenetic modulators,regulators for CD8+T cells,and transcriptional regulators of programmed cell death-ligand 1(PD-L1).Human peripheral blood mononuclear cell(Hu-PBMC)reconstruction mice were adopted for xenograft transplantation.Tumor specimens from a TNBC cohort and the clinical trial CTR20191353 were retrospectively analyzed.RNA-sequencing,Western blotting,qPCR and immunohistochemistry were used to assess gene expression.Coculture assays were performed to evaluate the regulation of TNBC cells on T cells.Chromatin immunoprecipitation and transposase-accessible chromatin sequencing were used to determine chromatin-binding and accessibility.Results The epigenetic modulator AT-rich interaction domain 1A(ARID1A)gene demonstrated the highest expression association with AIR relative to other epigenetic modulators in TNBC patients.Low ARID1A expression in TNBC,causing an immunosuppressive microenvironment,promoted AIR and inhibited CD8+T cell infiltration and activity through upregulating PD-L1.However,ARID1A did not directly regulate PD-L1 expression.We found that ARID1A directly bound the promoter of nucleophosmin 1(NPM1)and that low ARID1A expression increased NPM1 chromatin accessibility as well as gene expression,further activating PD-L1 transcription.In Hu-PBMC mice,atezolizumab demonstrated the potential to reverse ARID1A deficiency-induced AIR in TNBC by reducing tumor malignancy and activating anti-tumor immunity.In CTR20191353,ARID1A-low patients derived more benefit from pucotenlimab compared to ARID1A-high patients.Conclusions In AIR epigenetics,low ARID1A expression in TNBC contributed to AIR via the ARID1A/NPM1/PD-L1 axis,leading to poor outcome but sensitivity to ICI treatment.

GD2+ cancer stem cells in triple-negative breast cancer:mechanisms of resistance to breast cancer therapies

Research has led to the development of tailored treatment options for different cancers in different patients.Despite some treatments being able to provide remarkable responses,nearly all current treatments encounter the same issue:resistance.Here,we discuss our experiences with how breast cancers resist therapies.The focus of our discussion revolves around the cancer stem cell subpopulation and their mechanisms for resistance.