Analysis of Differential Gene Expression and Core Canonical Pathways Involved in the Epithelial to Mesenchymal Transition of Triple Negative Breast Cancer Cells by Ingenuity Pathway Analysis

Triple Negative Breast Cancer (TNBC) is a malignant form of cancer with very high mortality and morbidity. Epithelial to Mesenchymal Transition (EMT) is the most common pathophysiological change observed in cancer cells of epithelial origin that promotes metastasis, drug resistance and cancer stem cell formation. Since the information regarding differential gene expression in TNBC cells and cell signaling events leading to EMT is limited, this investigation was done by comparing transcriptomic data generated by RNA isolation and sequencing of a EMT model TNBC cell line in comparison to regular TNBC cells. RNA sequencing and Ingenuity Pathway Software Analysis (IPA) of the transcriptomic data revealed several upregulated and downregulated gene expressions along with novel core canonical pathways including Sirtuin signaling, Oxidative Phosphorylation and Mitochondrial dysfunction events involved in EMT changes of the TNBC cells.

Discovery of a small molecule targeting ULK1-modulated cell death of triple negative breast cancer in vitro and in vivo

OBJECTIVE To discover a small molecule targeting ULK1-modulated cell death of triple negative breast cancer and exploreits potential mechanisms.METHODS ULK1 expression was analyzed by The Cancer Genome Atlas(TCGA)analysis and tissue microarray(TMA)analysis.ULK1agonist was designed by using in silico screening,as well as modified by chemical synthesis and screened by kinase and anti-proliferative activities.The amino acid residues that key to the activation site of LYN-1604 were determined by site-directed mutagenesis,as well as in vitro kinase assay and ADP-Glo kinase assay.The mechanisms of LYN-1604 induced cell death were investigated by fluorescence microscope,western blotting,flow cytometry analysis,immunocytochemistry,as well as si RNA and GFP-m RFP-LC3 plasmid transfections.Potential ULK1 interactors were discovered by performing comparative microarray analysis and the therapeutic effect of LYN-1604 was assessed by xenograft breast cancer mouse model.RESULTS We found that ULK1 was remarkably downregulated in breast cancer tissue samples,especial y in triple negative breast cancer(TNBC).32 candidate smal molecules were synthesized,and we discovered a small molecule named LYN-1604 as the best candidate ULK1agonist.Additionally,we identified that three amino acid residues(LYS50,LEU53 and TYR89)were key to the activation site of LYN-1604 and ULK1.Subsequently,we demonstrated that LYN-1604 could induce autophagy-associated cell death via ULK complex(ULK1-m ATG13-FIP200-ATG101)in MDA-MB-231 cells.We also found that LYN-1604 induced cell death involved in ATF3,RAD21 and caspase 3,accompanied with autophagy and apoptosis.Moreover,we demonstrated that LYN-1604 had a good therapeutic potential on TNBC by targeting ULK1-modulated cell death in vivo.CONCLUSION We discovered a small molecule(LYN-1604)has therapeutic potential by targeting ULK1-modulated cell death associated with autophagy and apoptosis of TNBC in vitro and in vivo,which could be utilized as a new anti-TNBC drug candidate.

Systemic treatment strategies for triple-negative breast cancer

Triple-negative breast cancer(TNBC) is defined by the lack of immunohistochemical expression of the estrogen and progesterone receptors and human epidermal growth factor receptor 2(EGFR2). Most TNBC has a basal-like molecular phenotype by gene expression profiling and shares clinical and pathological features with hereditary BRCA1 related breast cancers. This review evaluates the activity of available chemotherapy and targeted agents in TNBC. A systematic review of PubM ed and conference databases was carried out to identify randomised clinical trials reporting outcomes in women with TNBC treated with chemotherapy and targeted agents. Our review identified TNBC studies of chemotherapy and targeted agents with different mechanisms of action, including induction of synthetic lethality and inhibition of angiogenesis, growth and survival pathways. TNBC is sensitive to taxanes and anthracyclins. Platinum agents are effective in TNBC patients with BRCA1 mutation, either alone or in combination with poly adenosine diphosphate polymerase 1 inhibitors. Combinations of ixabepilone and capecitabine have added to progression-free survival(PFS) without survival benefit in metastatic TNBC. Antiangiogenic agents, tyrosine kinase inhibitors and EGFR inhibitorsin combination with chemotherapy produced only modest gains in PFS and had little impact on survival. TNBC subgroups respond differentially to specific targeted agents. In future, the treatment needs to be tailored for a specific patient, depending on the molecular characteristics of their malignancy. TNBC being a chemosensitive entity, combination with targeted agents have not produced substantial improvements in outcomes. Appropriate patient selection with rationale combinations of targeted agents is needed for success.

Biomarkers in triple negative breast cancer:A review

Breast cancer is an intrinsically heterogeneous disease. In the world about 1 million cases of breast cancer are diagnosed annually and more than 170000 are triplenegative. Characteristic feature of triple negative breast cancer(TNBC) is that it lacks expression of oestrogen,progesterone and human epidermal growth factor receptor-2/neu receptors. They comprise 15%-20% of all breast cancers. We did a systematic review of Pub Med and conference databases to identify studies published on biomarkers in TNBC. We included studies with biomarkers including: Epidermal growth factor receptor,vascular endothelial growth factor,c-Myc,C-kit and basal cytokeratins,Poly(ADP-ribose) polymerase-1,p53,tyrosinase kinases,m-TOR,heat and shock proteins and TOP-2A in TNBC. We also looked for studies published on synthetic lethality and inhibition of angiogenesis,growth,and survival pathways. TNBC is a complex disease subtype with many subclasses. Majority TNBC have a basal-like molecular phenotype by gene expression profiling. Their clinical and pathologic features overlap with hereditary BRCA1 related breast cancers. Management of these tumours is a challenge to the clinician because of its aggressive behaviour,poor outcome,and absence of targeted therapies. As the complexity of this disease is being simplified over time new targets are also being discovered for the treatment of this disease. There are many biomarkers in TNBC being used in clinical practice. Biomarkers may be useful as prognostic or predictive indicators as well as suggest possible targets for novel therapies. Many targeted agents are being studied for treatment of TNBC.

Efficacy of platinum in advanced triple-negative breast cancer with germline BRCA mutation determined by next generation sequencing

Objective:To compare the efficacy of platinum-and non-platinum-based regimens as first-line treatment for advanced triple-negative breast cancer(TNBC)and analyze the relationship between their efficacy and BRCA gene status.Methods:Retrospectively analyze clinical data of 220 patients diagnosed pathologically with advanced TNBC and treated at the Department of Breast Oncology,Peking University Cancer Hospital from 2013 to 2018 and evaluate the efficacy of chemotherapy.A total of 114 patients had BRCA1/2 gene tested by next generation sequencing(NGS)using peripheral blood,and we analyzed the correlation between their efficacy and BRCA1/2 gene status.Results:Non-platinum-based chemotherapy(NPCT)was administered to 129 and platinum-based chemotherapy(PBCT)to 91 study patients.The clinical benefit rate(CBR)and median progression-free survival(PFS)were not statistically different between NPCT and PBCT groups.The median overall survival(OS)was 30.0 and 22.5 months for PBCT and NPCT group,respectively[P=0.090,hazard ratios(HR)=0.703].BRCA status was assessed in 114 patients,14 of whom had deleterious germline BRCA1/2(g BRCA)mutations(seven in each group).In PBCT group,the CBR was 85.7%and 35.1%for patients with and without deleterious g BRCA mutations,respectively(P=0.039).The median PFS were 14.9 and 5.3 months and median OS were 26.5 and 15.5 months for patients with and without deleterious g BRCA mutations,respectively(P=0.001,P=0.161,respectively).Patients in PBCT group had significantly greater rates of grade 3-4 anemia(5.5%vs.0%)and thrombocytopenia(8.8%vs.0%),whereas palmar-plantar erythrodysesthesia(12.4%vs.0%)and peripheral neuropathy(8.6%vs.1.1%)occurred more frequently in NPCT group.Conclusions:Platinum-based regimens are more effective in patients with deleterious g BRCA mutations,but no difference in patients without BRCA gene mutations,so non-platinum is an option in patients without BRCA gene mutations considering the toxicity and side effect.And we recommend that patients with advanced TNBC should have BRCA gene test.

Non-anthracycline-containing docetaxel and cyclophosphamide regimen is associated with sustained worse outcome compared with docetaxel, anthracycline and cyclophosphamide in neoadjuvant treatment of triple negative and HER2-positive breast cancer patients:

Objective： A previous study demonstrated that non-anthracycline-containing docetaxel plus cyclophosphamide（TC） regimen was inferior to docetaxel, anthracycline and cyclophosphamide（TAC） in neoadjuvant treatment of triple-negative breast cancer（TNBC） and human epidermal growth factor receptor-2-（HER2）-positive breast cancer in a short-term follow-up. Herein, long-term follow-up survival outcomes have been investigated.Methods： TNBC or HER2-positive patients were randomized to receive 6 cycles of TC or TAC neoadjuvant treatment. The primary endpoint was pathological complete remission（p CR）. Secondary endpoints included clinical response rate, event-free survival（EFS）, and overall survival（OS）.Results： A cohort of 96 patients consisted of 45 in TC and 51 in TAC arm. With a median follow-up period of53（range, 8-76） months, the patients achieving p CR post neoadjuvant chemotherapy exhibited superior EFS and OS than patients without p CR（P〈0.05）. TAC treatment resulted in consistently better EFS than TC treatment：the estimated 5-year EFS was 66.1% vs. 29.8%（P=0.002）. Moreover, the estimated 5-year OS was also in favor of TAC： 88.4% vs. 51.6%（P〈0.001）. Multivariable analysis demonstrated that the treatment regimen was an independent prognostic factor, and patients treated with TAC had a superior EFS [hazard ratio（HR）, 0.48; 95%confidence interval（95% CI）, 0.26-0.90; P=0.021] and OS（HR, 0.20; 95% CI, 0.08-0.60; P=0.003）.Conclusions： The updated long-term follow-up data demonstrated a sustained benefit in EFS and OS from anthracycline-containing TAC treatment, indicating that anthracycline is an essential and effective drug in this clinical trial.

Metronomic chemotherapy for non-metastatic triple negative breast cancer: Selection is the key

Triple negative breast cancer(TNBC) accounts for 15%-20% of all breast cancer, and is still defined as what it is not. Currently, TNBC is the only type of breast cancer for which there are no approved targeted therapies and maximum tolerated dose chemotherapy with taxanes and anthracycline-containing regimens is still the standard of care in both the neoadjuvant and adjuvant settings. In the last years, metronomic chemotherapy(MC) is being explored as an alternative to improve outcomes in TNBC. In the neoadjuvant setting, purely metronomic and hybrid approaches have been developed with the objective of increasing complete pathologic response(p CR) and prolonging disease free survival. These regimens proved to be very effective achieving pC R rates between 47%-60%, but at the cost of great toxicity. In the adjuvant setting, MC is used to intensify adjuvant chemotherapy and, more promisingly, as maintenance therapy for high-risk patients, especially those with no pC R after neoadjuvant chemotherapy. Considering the dismal prognosis of TNBC, any strategy that potentially improves outcomes, specially being the oral agents broadly available and inexpensive, should be considered and certainly warrants further exploration. Finally, the benefit of MC needs to be validated in properly designed clinical trials were the selection of the population is the key.

Triple negative breast cancer: special histological types and emerging therapeutic methods

Triple negative breast cancer(TN BC)is a complex and malignant breast cancer subtype that lacks expression of the estrogen receptor(ER),progesterone receptor(PR)and human epidermal growth factor receptor 2(H ER2),thereby making therapeutic targeting difficult.TNBC is generally considered to have high malignancy and poor prognosis.However,patients diagnosed with certain rare histomorphologic subtypes of TNBC have better prognosis than those diagnosed with typical triple negative breast cancer.In addition,with the discovery and development of novel treatment targets such as the androgen receptor(AR),PI3K/AKT/mTOR and AMPK signaling pathways,as well as emerging immunotherapies,the therapeutic options for TNBC are increasing.In this paper,we review the literature on various histological types of TNBC and focus on newly developed therapeutic strategies that target and potentially affect molecular pathways or emerging oncogenes,thus providing a basis for future tailored therapies focused on the mutational aspects of TNBC.

Overview of recent advances in metastatic triple negative breast cancer

Metastatic triple negative breast cancer(TNBC)has an aggressive phenotype with a predilection for visceral organs and brain.Best responses to chemotherapy are predominately in the first line.Recent studies have demonstrated improved progression free survival with the combination of atezolizumab/pembrolizumab and chemotherapy in programmed death-ligand 1 positive metastatic TNBC.However,a recent trial in a similar population showed no benefit for atezolizumab and paclitaxel which led to a Food and Drug Administration alert.Two phase III trials(OLYMPIAD and BROCADE3)demonstrated a benefit in progression free survival(PFS)but not overall survival in patients with BRCAassociated metastatic TNBC treated with Olaparib or Talazoparib respectively.For those treated with Talazoparib,the time to deterioration in health related-quality of life was also longer compared to chemotherapy.The BROCADE3 trial demonstrated that the combination of a platinum and veliparib increased PFS in first-line metastatic TNBC but at the cost of increased toxicity.There are no headto-head comparisons of a poly(adenosine diphosphate-ribose)polymerase inhibitors(PARPi)and platinums.There are unanswered questions regarding the role of PARPi maintenance after platinum therapy as is standard of care in BRCAassociated ovarian cancer.Other areas of therapeutic interest include targeting aberrations in the phosphoinositide 3-kinase pathway,protein kinase B,mammalian target of rapamycin or utilising antibody drug conjugates.This review focusses on recent and emerging therapeutic options in metastatic TNBC.We searched PubMed,clinicaltrials.gov and recent international meetings from American Society of Clinical Oncology,San Antonio Breast Cancer Conference and the European Society of Medical Oncology.

RNA-seq analysis identified hormone-related genes associated with prognosis of triple negative breast cancer

Triple negative breast cancer(TNBC) is an aggressive subtype of breast cancer that currently lacks effective biomarkers and therapeutic targets required to investigate the diagnosis and treatment of TNBC. Here we performed a comprehensive differential analysis of 165 TNBC samples by integrating RNA-seq data of breast tumor tissues and adjacent normal tissues from both our cohort and The Cancer Genome Atlas(TCGA). Pathway enrichment analysis was conducted to evaluate the biological function of TNBC-specific expressed genes. Further multivariate Cox proportional hazard regression was performed to evaluate the effect of these genes on TNBC prognosis. In this report, we identified a total of 148 TNBC-specific expressed genes that were primarily enriched in mammary gland morphogenesis and hormone levels related pathways, suggesting that mammary gland morphogenesis might play a unique role in TNBC patients differing from other breast cancer types. Further survival analysis revealed that nine genes(FSIP1, ADCY5, FSD1, HMSD, CMTM5, AFF3, CYP2 A7, ATP1 A2,and C11 orf86) were significantly associated with the prognosis of TNBC patients, while three of them(ADCY5,CYP2 A7, and ATP1 A2) were involved in the hormone-related pathways. These findings indicated the vital role of the hormone-related genes in TNBC tumorigenesis and may provide some independent prognostic markers as well as novel therapeutic targets for TNBC.

Inhibition of growth and metastasis of triple-negative breast cancer targeted by Traditional Chinese Medicine Tubeimu in orthotopic mice models

Objective： Triple-negative breast cancer（TNBC） is highly invasive and metastatic, which is in urgent need of transformative therapeutics. Tubeimu（TBM）, the rhizome of Bolbostemma paniculatum（Maxim.） Franquet, is one of the Chinese medicinal herbs used for breast diseases since the ancient times. The present study evaluated the efficacy, especially the anti-metastatic effects of the dichloromethane extract of Tubeimu（ETBM） on TNBC orthotopic mouse models and cell lines.Methods： We applied real-time imaging on florescent orthotopic TNBC mice model and tested cell migration and invasion abilities with MDA-MB-231 cell line. Digital gene expression sequencing was performed and Kyoto Encyclopedia of Genes and Genomes（KEGG） analysis applied to explore the pathways influenced by ETBM.Moreover, quantitative real-time polymerase chain reactions（q RT-PCR） and Western blot were delivered to confirm the gene expression changes.Results： ETBM exhibited noticeable control on tumor metastasis and growth of TNBC tumors with no obvious toxicity. In compliance with this, it also showed inhibition of cell migration and invasion in vitro. Its impact on the changed biological behavior in TNBC may be a result of decreased expression of integrin β1（ITGβ1）, integrin β8（ITGβ8） and Rho GTPase activating protein 5（ARHGAP5）, which disabled the focal adhesion pathway and caused change in cell morphology.Conclusions： This study reveals that ETBM has anti-metastatic effects on MDA-MB-231-GFP tumor and may lead to a new therapeutic agent for the integrative treatment of highly invasive TNBC.

Platinum is essential in neoadjuvant treatment of triple-negative breast cancer: a network meta-analysis

Objective:This study aimed to assess the efficacy and safety of various neoadjuvant regimens for patients diagnosed with early-stage or locally advanced triple-negative breast cancer(TNBC).Methods:Medline,EMBASE,Cochrane Library,and Web of Science were searched in May 2020 to identify randomized controlled trials(RCTs).Bayesian network meta-analysis(NMA)was performed(Registration:PROSPERO CRD42020223012).Results:A total of 35 RCTs involving 8,424 participants were reviewed,of which 22 RCTs with 5,203 patients were included in this NMA focusing on pathologic complete response(pCR).An anthracycline-taxane-based(AT)regimen combined with a platinum(ATPt)[odds ratio(OR)=2.04,95%credible interval(CrI):1.69,2.48]regimen,and a docetaxel regimen combined with a carboplatin(TCb;OR=2.16,95%CrI:1.20,3.91)regimen improved pCR beyond that with AT only.AT and ATPt combined with targeted therapy[including bevacizumab(Bev),veliparib,atezolizumab,or pembrolizumab]also improved pCR.Five RCTs included in this NMA reported serious adverse events(SAEs)or grade≥3 AEs.TCb was associated with fewer grade≥3 AEs than was AT(OR=0.66,95%CrI:0.23,1.72)alone.In contrast,ATPt,AT+Bev,ATPt+Bev,ATPt+veliparib,and ATPt+pembrolizumab were associated with more SAEs than was AT alone.Conclusions:In patients with TNBC,platinum-based neoadjuvant regimens ATPt and TCb increase pCR beyond that with AT alone,but TCb appears to be better tolerated than either AT or ATPt.Platinum-based regimens combined with targeted therapies(Bev,PARPi,and PD-1/PD-L1 inhibitor)also improve the pCR rate beyond that with AT alone,but this benefit is accompanied by greater toxicity.

ALDH 1A1 and caveolin-1 expression in triple negative breast cancer

Objective Triple negative breast cancer(TNBC) contains a high proportion of breast cancer stem cells(BCSCs) and exhibits resistance to chemotherapy treatments. Therefore, the identification of BCSCs that are novel molecular targets may improve patient survival. Aldehyde dehydrogenase-1(ALDH 1 A1) has been considered a cancer stem cell marker in different tumors. Caveolin-1(Cav-1), a membrane transporter protein, regulates cancer chemo-resistance and stem cell signaling. Thus, the aim of this study was to evaluate the expression of ALDH 1 A1 and Cav-1 in patients with TNBC by immunohistochemistry(IHC) and to correlate their expression with clinical and pathological parameters.Methods Paraffin blocks of 30 breast cancer patients who underwent modified radical mastectomy between January 2013 and December 2016 in Zagazig University Hospitals(Egypt) were evaluated. Antibodies to ALDH 1 A1 and Cav-1 were used. Results ALDH 1 A1 and Cav-1 significantly correlated with tumor size. A significant association between ALDH 1 A1/Cav-1 IHC staining and relapse was found. Cav-1 and ALDH 1 A1-positive expression correlated with a short 3-year disease-free survival rate and a 3-year overall survival rate(P < 0.001). Conclusion ALDH 1 A1 and Cav-1 expression in TNBC was significantly positively correlated with poor clinicopathological parameters and shortened survival. Expression of both markers was significantly positively correlated with each other(P < 0.001). ALDH 1 A1 and Cav-1 could be potential therapeutic targets in breast cancer.

Why natural killer cells in triple negative breast cancer?

The triple-negative subtype of breast cancer(TNBC)has the bleakest prognosis,owing to its lack of either hormone receptor as well as human epidermal growth factor receptor 2.Henceforth,immunotherapy has emerged as the front-runner for TNBC treatment,which avoids potentially damaging chemotherapeutics.However,despite its documented association with aggressive side effects and developed resistance,immune checkpoint blockade continues to dominate the TNBC immunotherapy scene.These immune checkpoint blockade drawbacks necessitate the exploration of other immunotherapeutic methods that would expand options for TNBC patients.One such method is the exploitation and recruitment of natural killer cells,which by harnessing the innate rather than adaptive immune system could potentially circumvent the downsides of immune checkpoint blockade.In this review,the authors will elucidate the advantageousness of natural killer cell-based immuno-oncology in TNBC as well as demonstrate the need to more extensively research such therapies in the future.

Effect of dendritic cell/cytokine-induced killer cell immunobiological cancer therapy combined with adjuvant chemotherapy in patients with triple-negative breast cancer

Objective The aim of the present study was to investigate the effect of dendritic cell(DC)/cytokine-induced killer cell(CIK) immunobiological cancer therapy in patients with triple-negative breast cancer(TNBC) who underwent adjuvant chemotherapy. Methods From January 2010 to October 2013, 120 patients with postoperative TNBC were recruited and included in the study. Patients were enrolled in one of two groups according to whether they accepted DC/CIK immunobiological cancer therapy during adjuvant chemotherapy; the patients in the DC/CIK group underwent adjuvant chemotherapy combined with DC/CIK immunobiological cancer therapy, and the control group underwent adjuvant chemotherapy alone. When six cycles of adjuvant chemotherapy and six cycles of DC/CIK immunobiological cancer therapy had been completed, differences between the two groups with regard to quality of life(Qo L), immunological indicators(CD3, CD4, CD8, and NK cell levels), disease-free survival(DFS), and side effects of chemotherapy and DC/CIK treatment were evaluated.Results In the DC/CIK group, the proportion of NK cells and CD3+ and CD4+ T-cell subgroups significantly increased, and the proportion of CD8+ cells decreased when they were compared before and after DC/CIK therapy(P < 0.05). However, there were no significant changes in the control group. By the final follow-up, DFS of the treatment group and the control group was 38.4 and 34.2 months, respectively. The Qo L improved in the patients treated with chemotherapy plus DC/CIK therapy compared with the patients treated with chemotherapy alone, and the difference between groups was significant(P < 0.05). The side effects of two groups were tolerable and not significantly different between the two groups.Conclusion The DC/CIK treatment had potential benefits for patients with TNBC compared with the control group, and was not associated with any obvious side effects. Therefore, DC/CIK therapy is a safe and effective method for the treatment of TNBC.

Clinicopathological Characters of Triple Negative Breast Cancer

Objective： To study the clinicopathological characters Methods： A total of 629 patients with breast cancer of triple negative breast cancer （TNBC）. were reviewed, who were treated from 2003 to 2007 in Chongqing Cancer Institute. The comparison of clinicopathological features including TNM classification, histological type, tumor location, axillary lymphonodes status and neoadjuvant chemotherapy between TNBC and nontriple negative breast cancer （NTNBC） was performed. The overall response was evaluated by whether the patients achieve complete remission （CR） and partial remission （PR） after chemotherapy. Results： There were 69 TNBCs in the 629 patients with breast cancer. The premenopausal patients, which was found in 49/69 of TNBCs, was more than NTNBCs. The average diameter of tumor in TNBC group was 4.1 cm, lager than NTNBC group. TNBC with axillary nodes metastasis occurred in 21 cases, and the axillary nodes metastasis rate was lower than NTNBC. The positive expression rate of p53 in TNBC was 44.9%, and the overall response （CR＋PR） was 72.2%. No statistical differences were found regarding the positive expression rate of p53 and the overall response between TNBC and NTNBC. Conclusion： TNBC were a group of primary breast cancers with triple negative, tending to occur in premenopausal women, with larger tumors, lower axillary nodes metastasis rate. TNBC had worse clinical prognosis and currently lacked effective targeted therapies.

Narrowing the focus:Therapeutic cell surface targets for refractory triple-negative breast cancer

Triple-negative breast cancer(TNBC)is defined as a type of breast cancer with lack of expression of estrogen receptor,progesterone receptor and human epidermal growth factor 2 protein.In comparison to other types of breast cancer,TNBC characterizes for its aggressive behavior,more prone to early recurrence and a disease with poor response to molecular target therapy.Although TNBC is identified in only 25%-30%of American breast cancer cases annually,these tumors continue to be a therapeutic challenge for clinicians for several reasons:Tumor heterogeneity,limited and toxic systemic therapy options,and often resistance to current standard therapy,characterized by progressive disease on treatment,residual tumor after cytotoxic chemotherapy,and early recurrence after complete surgical excision.Cell-surface targeted therapies have been successful for breast cancer in general,however there are currently no approved cell-surface targeted therapies specifically indicated for TNBC.Recently,several cell-surface targets have been identified as candidates for treatment of TNBC and associated targeted therapies are in development.The purpose of this work is to review the current clinical challenges posed by TNBC,the therapeutic approaches currently in use,and provide an overview of developing cell surface targeting approaches to improve outcomes for treatment resistant TNBC.

Forkhead box P3 and indoleamine 2,3-dioxygenase co-expression in Pakistani triple negative breast cancer patients

BACKGROUND Forkhead box P3(FOXP3)is a specific marker for immunosuppressive regulatory T(T-reg)cells.T-regs and an immunosuppressive enzyme,indoleamine 2,3-dioxygenase(IDO),are associated with advanced disease in cancer.AIM To evaluate the co-expression of FOXP3 and IDO in triple negative breast cancer(TNBC)with respect to hormone-positive breast cancer patients from Pakistan.METHODS Immunohistochemistry was performed to analyze the expression of FOXP3,IDO,estrogen receptor,progesterone receptor,and human epidermal growth factor receptor on tissues of breast cancer patients(n=100):Hormone-positive breast cancer(n=51)and TNBC(n=49).A total of 100 patients were characterized as FOXP3 negative vs positive and further categorized based on low,medium,and high IDO expression score.Univariate and multivariate logistic regression models were used.RESULTS Out of 100 breast tumors,25%expressed FOXP3 positive T-regs.A significant coexpression of FOXP3 and IDO was observed among patients with TNBC(P=0.01)compared to those with hormone-positive breast cancer.Two variables were identified as significant independent risk factors for FOXP3 positive:IDO expression high(adjusted odds ratio(AOR)5.90;95%confidence interval(CI):1.22-28.64;P=0.03)and TNBC(AOR 2.80;95%CI:0.96-7.95;P=0.05).CONCLUSION Our data showed that FOXP3 positive cells might be associated with high expression of IDO in TNBC patients.FOXP3 and IDO co-expression may also suggest its involvement in disease,and evaluation of FOXP3 and IDO expression in TNBC patients may offer a new therapeutic option.

Effects of TAM-derived exosomes on migration and invasion of MDA-MB- 231 cells in triple negative breast cancer

Objective:To investigate the effects of exosomes derived from tumor-associated macrophages(TAMs)on migration and invasion of MDA-MB-231 cells in triple negative breast cancer.Methods:The MDA-MB-231 cells,a human breast cancer cell line,were divided into the experimental group and the blank control group.The exosomes were isolated from the supernatant of human peripheral blood mononuclear cells(THP-1)by a multi-step ultracentrifugal procedure.The effects of exosomes on migration and invasion of MDAMB-231 cells were studied by endocytosis assay of exosomes,Transwell migration assay and Celigo scratch assay.Results:Exosomes were ingested and endocytosed by MDAMB-231 cells,brought into the cytoplasm at 3h and enriched significantly at 6h.Compared with the blank control group,the number of metastatic cells in the Transwell compartment(241±3.35)and its variation relative to normal cells(144±2.33)in the experimental group were significantly increased(P<0.05).The 24 h migration rate of MDA-MB-231 cells treated with exosomes in the scratch assay showed similar results(39.86±3.47 in the experimental group vs.24.48±2.97 in the control group,P<0.05).Conclusion:TAM-derived exosomes can be ingested and endocytosed by MDA-MB-231 cells,and promote their migration and invasion in vitro.

Treatment Patterns and Mortality Risk among Elderly Patients with Metastatic Triple Negative Breast Cancer in the United States: An Observational Cohort Study Using SEER-Medicare Data

Purpose: Triple negative breast cancer is more aggressive than other breast cancer subtypes and accounts for up to 20% of all breast cancers. Despite the poorer prognosis, there are no approved targeted treatments available and chemotherapy remains the only choice. We examined treatment patterns and outcomes among elderly metastatic triple-negative breast cancer (mTNBC) patients in routine clinical practice. Methods: Patients were identified from the linked SEER-Medicare database between 1/1/2001 and 12/31/2013 and included de novo Stage IV (n = 776) and patients with distant metastasis followed an initial diagnosis of Stage I - III disease (n = 1851). Kaplan-Meier analyses and time-varying Cox proportional hazards regression were used to assess overall survival (OS). Results: The mean age at metastatic diagnosis was 77.6 years and 1259 (48%) patients received chemotherapy. Compared to <70 year olds, ≥70 year olds had worse performance status, higher comorbidity burden, and were less likely to receive chemotherapy (45% vs. 66%). Patients treated with chemotherapy had increased OS compared to untreated patients, and the survival advantage was more pronounced in the -month longer unadjusted OS compared to the ≥70 cohort (log rank p < 0.0001). This finding was supported in the adjusted multivariate model which showed a 46% increased risk of death for untreated patients in the <70 year olds and a 17% increased risk of death for untreated patients in the ≥70 year olds (vs. treated). Conclusions: In this real-world analysis, 48% of elderly mTNBC patients did not receive chemotherapy and a greater proportion were untreated in the ≥70 year old cohort (55%). Although the survival benefits of chemotherapy were greater in the younger cohort, the benefits of treatment persisted in ≥70 year olds. These findings suggest opportunities exist to improve the clinical treatment of elderly mTNBC patients.