Breast Cancer Awareness Month

A randomized phase 2 clinical trial has recently shown no benefit of the combination eribulin and pembrolizumab over pembrolizumab alone in HR + metastatic breast cancer patients (NCT03051659). Here, the authors are reporting the final OS data and biomarker analyses on a subset of samples to analyze molecular correlates

Acquisition of CDK4/6i resistance represents a major clinical challenge. Here, the authors report that inhibition of CK1ε can prevent acquisition of CDK4/6i resistance, potentiating the therapeutic efficacy of CDK4/6i in human breast cancer.

Disseminated tumor cells often become dormant before awakening for metastatic growth. Here, the authors report that the lncRNA, NR2F1-AS1, is upregulated in dormant mesenchymal-like breast cancer stem-like cells and promotes dissemination but inhibits proliferation, leading to metastatic dormancy.

Transposon based screens carried out in mice can identify genes critical for tumourigensis. Here, the authors describe transposon screens in mouse models of breast cancer and highlight a large group of tumour suppressors that could underlie selection for common chromosome arm losses in cancer.

Bone metastasis is a major complication of breast cancer (BC) and ER⁺ tumors have a higher incidence of bone metastasis than ER⁻ tumors. Here, the authors report that miR‐19a in exosomes and the bone matrix protein, IBSP, are upregulated and secreted by bone tropic ER⁺ BC cells, where they cooperatively induce osteoclastogenesis and promote bone colonization.

The classification of breast lesions as indolent or aggressive to tailor treatment is crucial. Here, the authors use single-cell transcriptomics and multiparametric imaging of a breast cancer mouse model, report distinct tumor-immune features for the two types of lesions, and suggest the role of IL-17 signaling in disease progression.

Germline mutations in BRCA1 or BRCA2 tumour suppressor genes predispose to different cancers, as does oncogene activation. Here the authors reveal that aberrant transcription of specific genes triggered by activation of the oncogene β-catenin causes replication failure and cell death in the context of BRCA1/2 deficiency.

Circulating tumor cell (CTC) clusters are more efficient at mediating metastasis as compared to single cells and are associated with poor prognosis in breast cancer. Here, the authors show that ICAM1 is enriched in CTC clusters and its loss suppresses cell-cell interaction and CTC cluster formation, and propose ICAM1 as a therapeutic target for treating breast cancer metastasis.

Finding therapeutic strategies for aggressive triple negative breast cancer (TNBC) is an important challenge in clinical practice. Here, the authors identify a multi-kinases inhibitor with antitumor activity and able overcome chemotherapy resistance of TNBC in vivo.

Vasculogenic mimicry (VM) contributes to the development of triple-negative breast cancer. In this study, the authors show that TEM8 is expressed in VM-forming breast cancer stem cells and it promotes stemness and VM differentiation capacity through a RhoC/ROCK1/SMAD5 axis

Bone metastases are associated with poor prognosis in patients with breast cancer and limited therapeutic options. Here the authors exploit near-infrared light responsive macrophages for the tumor-selective delivery of oxaliplatin prodrug for chemo-photodynamic therapy of primary and bone metastatic breast cancer.

The epithelial-mesenchymal transition (EMT) has been implicated in stem cell properties and therapeutic resistance in cancer. Here, the authors show organoids derived from mesenchymal breast cancers exhibit a spikey structure which can be reverted and exploited for screening drugs that reverse EMT.

GWAS have enhanced our understanding for the genetic basis of breast cancer, but the majority of them were performed for European ancestry populations. Here, the authors use a cross-ancestry approach and report seven new variants associated with breast cancer risk among women of African ancestry.

The cellular origin and oncogenic drivers promoting claudin-low breast cancer are undefined. Here, the authors report that the consistent activation of oncogenic RAS signaling, as well as regulators of EMT, play a crucial role in the cellular plasticity and maintenance of the mesenchymal and stem cell characteristics of claudin-low mammary cancer cells.

Intratumor heterogeneity in breast cancer can limit the clinical success of antibody-drug conjugates (ADCs). In this study, the authors develop dual payload Her2-ADCs that show potent anti-tumor activity against heterogeneous breast tumors in vivo.

Complex I inhibition induces oxidative stress leading to cancer cell cytotoxicity. Here, the authors show, in breast cancer models, that inflammatory mediators can potentiate complex I inhibitor phenformin cytotoxicity through STAT1-mediated downregulation of the reactive oxygen species scavenger NQO1.

The PI(3,4)P₂ 4-phosphatase, INPP4B, functions as a tumour suppressor in triple negative breast cancer. Here, the authors show that INPP4B enhances proliferation and growth of PIK3CA-mutant ER⁺ breast cancers by promoting PI3Kα-dependent late endosome formation and trafficking that leads to the activation of Wnt/β-catenin signalling.

Triple negative breast cancer (TNBC) lack effective therapies. Here, through an in vivo genome-wide CRISPR screen in TNBCs, the authors identify tumorigenic functions for components of the mTORC1/2 complex and of the YAP/Hippo pathway, and demonstrate that pharmacological inhibition of mTOR and YAP reduces tumour growth in vivo.

Resistance to endocrine treatment in ER+/HER2- breast cancer patients remains a significant clinical problem. Here, the authors demonstrate that loss of the MutL mismatch repair complex can serve as a first-in-class predictive biomarker for combinatorial inhibition of HER2 to overcome the emergence of endocrine treatment resistance.

Human ribonuclease 1 (hRNase 1) regulates innate immunity, hemostasis and RNA clearance. Here, the authors report an alternative function of hRNase 1 as a secretory ligand of Eph receptor EphA4 to enhance breast cancer stemness and promote breast tumour initiation.

Tumour necroptosis is regulated by RIPK3 during tumour development. Here the authors show that ZBP1 is an upstream mediator of RIPK3 in tumour necroptosis and that glucose deprivation induces the release of mitochondrial DNA, which binds to ZBP1 to activate ZBP1-mediated necroptosis in breast cancer.

B7H3 is a transmembrane B7 family checkpoint molecule present on many cancer cells. Here the authors show that FUT8 mediates fucosylation of B7H3 to limit the immune response to triple-negative breast cancer as a potentially targeted mechanism of non-responsiveness to current checkpoint therapies.

Resistance to Herceptin represents a major challenge for successful treatment of HER2-positive breast cancer. Here, the authors demonstrate that the activation of the IGF2/IRS1 signal caused by disruption of a negative feedback loop between FOXO3a-miR-128/miR-30/miR-193 induces Herceptin resistance.

A thermophoretic aptasensor can be used to profile cancer-associated proteins of extracellular vesicles (EVs) in patients’ plasma. Here, the authors use this technique to develop an EV-signature able to discriminate metastatic breast cancer, monitor treatment response, and predict patients’ progression-free survival.

Circulating tumour DNA can provide useful information on disease burden. Here, the authors analysed circulating tumour DNA from 800 patients from a breast cancer clinical trial and investigate the subclonal nature of the disease, and identify DNA mutations associated with resistance and poor survival.

Cell-free RNA (cfRNA) is a promising analyte for cancer diagnosis. Here, the authors determine the baseline cell-free transcriptome in the absence of cancer and identify tissue- and subtype-specific cfRNA biomarkers in breast and lung cancer patients.

Triple-negative breast cancer (TNBC) is an aggressive breast cancer subtype with poor prognostic outcomes. Here the authors characterize super-enhancer heterogeneity and they identify genes that are specifically regulated by TNBC-specific super-enhancers, including FOXC1, MET and ANLN.

Cancers in different populations have been shown to be genetically distinct. Here, the authors sequence breast cancers from Mexican-Hispanic patients and find that these patients have a higher percentage of Akt1 mutations compared to Caucasian and Asian populations, suggesting these are clinically actionable.

Reduced expression of EFA6B is found in highly metastatic breast cancer subtypes. Here, the authors report that loss of EFA6B promotes collective invasion through activation of the epithelial-to-mesenchymal transition program and CDC42-dependent signalling pathways in breast cancer.

Immune cells infiltrating the tumour microenvironment play critical roles in disease pathogenesis and the immune response. Here the authors present the characterisation of infiltrating B cells in breast tumours by the formation of an atlas created from paired RNA sequence and antigen receptor profiling.

The heterogeneity of breast cancer has a major role in drug response and resistance. In this study, the authors use patient-derived tumour xenografts as a platform for drug testing and correlation with single-cell proteomic phenotypes characterized by mass cytometry.

Adipogenesis associated Mth938 Domain Containing gene (AAMDC) is frequently amplified in the IntClus2 subgroup of ER + breast cancer. Here, the authors show that AAMDC drives tumourigenesis through activating PI3K-AKT-mTOR pathway for metabolic reprogramming.

Endocrine therapy has been the mainstay for hormone responsive breast cancer treatment. Here, Garcia-Martinez and colleagues discuss epigenetic mechanisms regulating ER + breast cancer and endocrine therapy resistance, and highlight approaches to rewire the cancer epigenome to improve targeted therapies for this cancer.

BRCA1 driven breast cancer arises from luminal progenitor cells but how BRCA1 loss-of-function affects the luminal progenitor cell state during premalignant stages of the disease is still unclear. Here, the authors demonstrate an aberrant differentiation of luminal progenitors towards a partial secretory luminal cell phenotype that occurs in a Brca1 deficient mouse model of breast cancer at early stages of tumour initiation and in breast cells from BRCA1 carriers.

The mechanisms that shape the regulatory T cell repertoire in patients with cancer are not completely understood. Here, the authors observe that, in breast cancer patients, tumor-resident regulatory T cells do not show clonal relationship with their circulating counterpart, but share a common origin with intratumoral antigen-experienced conventional T cells.

Breast cancer risk for BRCA1/BRCA2 mutation carriers varies depending on other genetic factors. Here, the authors perform a case-only genome-wide association study and highlight novel loci associated with breast cancer risk for BRCA1/BRCA2 mutation carriers.

Dormancy of disseminated cancer cells has been described in patients with breast cancer and associated with late metastatic relapses. Here the authors show that CD39⁺PD-1⁺CD8⁺ T cells correlate with increased disease free survival post-resection in breast cancer patients, and promote dormancy in a preclinical model.

Clinical estrogen receptor (ER) testing for breast cancer is limited in predicting response to endocrine therapy (ET). In this phase 2 clinical trial, authors demonstrate that the responsiveness to ET can be predicted by use of PET/CT with 21-[¹⁸F]fluorofuranylnorprogesterone (FFNP) to detect the change in tumor progesterone receptor (PgR) levels after a one-day estradiol challenge.

Smoking is known to impact tumor immunity and promote tumor progression. Here, the authors show that chronic nicotine exposure promotes the lung pre-metastatic niche formation by recruiting pro-tumor N2-neutrophils that release lipocalin-2.

Although activated Notch receptors have been associated with chemoresistance in cancer, the role of specific Notch ligands remain elusive. Here, the authors show that in breast cells the Notch ligand DLL1 is expressed in cells with a cancer stem cell phenotype and promote doxorubicin resistance in part through NF-kB, as well as metastasis.

Molecular profiling of breast cancer in non-Caucasian populations remains underexplored. Here the authors report a high prevalence of HER2-subtypes and enriched immune score with improved survival and higher rates of TP53 somatic mutations with poorer survival in ER+ tumours in a Malaysian cohort.

A group of long non-coding RNAs (lncRNAs), Mammary Tumor Associated RNAs 1-30 (MaTARs 1-30), are differentially expressed between mammary tumor cells and normal mammary epithelial cells. Here the authors report that MaTAR25 plays a role in breast cancer cell proliferation, migration and invasion by regulating the expression of the Tensin1 gene in trans.

Identifying women at high risk of breast cancer has important implications for screening. Here, the authors demonstrate that polygenic risk scores improve breast cancer risk prediction in the population, in women with mutations in high-risk genes and in women with close relatives with the disease.

Receptor activator of nuclear factor-κB (RANK)/RANK-ligand (RANKL) signaling regulates the tumor-immune crosstalk. Here the authors show that systemic RANKL inhibition promotes CD8 + T cell infiltration in patients with early breast cancer and that loss of RANK signaling in tumor cells drives a T cell-dependent anti-tumor response in preclinical models.

The mechanisms underlying the growth of breast cancer metastasis in the brain are unclear. Here, the authors use an intracranial injection mouse model and single-cell analysis of patient circulating tumour cells to demonstrate that increased hypoxic and HIF1A signalling promotes tumour growth in the brain.

Neoadjuvant chemotherapy is a therapeutic option for the treatment of breast cancer. Here, the authors characterize changes in the gene expression profiles and immune microenvironment in serial breast cancer biopsies taken before, during and after neoadjuvant chemotherapy.

Resistance to anti-HER2 therapies in breast cancer remains a significant clinical challenge. Here, the authors demonstrate that EZH2 regulates response to HER2-targeting therapies in breast cancer, in part, by modulating the expression of PPP2R2B.

HER2+ breast cancer patients can often develop resistance to trastuzumab and therefore potential combination therapies need to be explored. Here, the authors report the results of a multi-center randomized phase II clinical trial evaluating the pathological and molecular responses associated with trastuzumab and/or lapatinib in combination with chemotherapy in HER2+ breast cancer patients.

Altered lipid metabolism has been associated with tumour malignancy, but underlying mechanisms are not clear. Here the authors show that proto-oncogene Src interacts and phosphorylates metabolic enzyme phosphatidic acid phosphatase LPIN1 (lipin-1) to promote growth and metastasis in breast cancer.

Determination of estrogen receptor status (ERS) in breast cancer tissue requires immunohistochemistry, which is sensitive to the vagaries of sample processing and the subjectivity of pathologists. Here the authors present a deep learning model that determines ERS from H&E stained tissue, which could improve oncology decisions in under-resourced settings.

Chinese breast cancer patients have not been well represented in clinical sequencing studies. Here the authors analyse the mutational landscape of 1,134 Chinese breast cancer patients, finding actionable targets and a higher prevalence of p53 and Hippo pathway mutations compared to Western cohorts.

Cancers deficient in homologous recombination can benefit from treatment with poly ADP-ribose polymerase (PARP) inhibitors. Here, the authors generated a classifier that can predict homologous recombination deficiency from genomic data and suggest several cancer types that may benefit from PARP inhibitor treatment.

Cyclin D1 is involved in tamoxifen resistance in breast cancer (BC) but how it is regulated is unclear. Here, the authors demonstrate that the LncRNA DILA1 contributes to tamoxifen resistance in breast cancer by binding to Cyclin D1 and preventing its degradation.

The 17q23 amplicon is associated with poor outcome in ER⁺ breast cancers, but the causal genes responsible endocrine resistance in this region are unclear. In this study, the authors demonstrate that PRR11 located at 17q23, is critical for conferring endocrine resistance through activation of PI3K signalling and therefore propose PI3K inhibition as a treatment for PRR11-amplified breast cancers.

Apart from the enzymatic role of ketohexokinase isoform A (KHK-A) in fructose metabolism the alternative physiological functions of the enzyme are unclear. Here, the authors show that KHK-A mediates fructose-induced metastasis in breast cancer through a nuclear role in repressing the transcriptional activity of the cell-adhesion molecule CDH1.

Cytotoxic T lymphocyte (CTL)-based immunotherapies can induce tumor regressions by targeting HLA class I-bound tumor-associated peptides. Here, the authors identified a peptide derived from Vestigial-like 1 (VGLL1) as a shared, potentially therapeutic CTL target expressed by multiple cancer types.

The transcription factor Zeb1 is known to promote tumorigenesis and stemness in breast cancer. Here the authors show that tumor endothelial Jagged1 induces activation of Notch1 signaling and increases Zeb1 expression in neighboring breast cancer stem cells, promoting tumor aggressiveness.

The lysosomal aspartic protease Cathepsin D (CTSD) is associated with breast cancer progression. Here the authors show that selective inactivation of CTSD in mammary epithelium delays tumor onset due to impaired mTORC1 signaling, but resumes malignant growth due to compensatory oncogenic pathways

Mammographic density represents one the strongest predictors of breast cancer risk. Here the authors perform genome-wide association study meta-analysis of women screened with full-field digital mammography and identify 31 previously unreported loci associated with mammographic density phenotypes.

Tumours are made up of heterogeneous subclones. Here, the authors show using breast cancer imaging and gene expression datasets that these subclones can be inferred by the deconvolution of gene expression data, mapped to MRI derived radiogenomic signatures and used to estimate prognosis.

TET2 loss is associated with human cancers but its role in the mammary gland development and tumorigenesis is unclear. Here, the authors show that TET2–FOXP1 complex mediates demethylation of genes involved in luminal lineage commitment and endocrine response, underlying a role of TET2 loss in endocrine resistant breast cancer.

Schizophrenia has been associated with increased risk of breast cancer, yet the risk of schizophrenia following breast cancer is unclear. Here, the authors show a bidirectional association between breast cancer and schizophrenia in Sweden and a shared genetic contribution to both diseases.

The emergence of tumour adaptive radioresistance can limit the success of radiation therapy and immunotherapy in breast cancer. In this study, the authors demonstrate that CD47 and HER2 are coordinating in tumor response to radiation and that co-blockage of both receptors can eliminate radiorestistant breast cancer cells.

A clinical trial published in Nature Communications examined the effect of fasting-mimicking diet (FMD) during chemotherapy in breast cancer patients. The overall negative study results highlight the need for ameliorating future trial design and investigating alternative FMD-based therapeutic combinations.

The emergence of tumour adaptive radioresistance can limit the success of radiation therapy and immunotherapy in breast cancer. In this study, the authors demonstrate that CD47 and HER2 are coordinating in tumor response to radiation and that co-blockage of both receptors can eliminate radiorestistant breast cancer cells.

Polygenic risk scores predict the likelihood that an individual will develop a certain cancer, however these are often specific for a given population. Here, the authors show that a risk score developed to assess the risk of breast cancer in European women can also predict risk in Asian populations.

TET2 loss is associated with human cancers but its role in the mammary gland development and tumorigenesis is unclear. Here, the authors show that TET2–FOXP1 complex mediates demethylation of genes involved in luminal lineage commitment and endocrine response, underlying a role of TET2 loss in endocrine resistant breast cancer.

High levels of Fusobacterium nucleatum have been associated with poor overall survival in patients with colorectal and esophageal cancer. Here, the authors show that F. nucleatum is abundant in breast cancer samples and that the colonization by F. nucleatum accelerates tumor growth and metastasis in preclinical breast cancer models.

Comparison of spontaneous canine cancers and human cancers may illuminate future therapeutic avenues. Here, genomic analyses of these tumors highlights a convergence on PI3K-Akt oncogenic pathways.

How cancer cells engage the microenvironment to establish metastasis is poorly understood. Here, the authors show that CXCR3-expressing breast cancer cells secrete IL-1 to induce a paracrine crosstalk with fibroblasts in the lung, which involves CXCL9/10 production and results in colonization of the lung.

Anti-VEGF therapy has many limitations that might be resolved by using combination treatment approaches. Here, the authors demonstrate that the dual-targeting of VEGF and PDGF is required for targeting resistant FGF2+ tumors which depend on the recruitment of pericytes on tumor microvessels.

Triple negative breast cancer is a deadly form of breast cancer with limited therapeutic options. Here the authors show the efficacy of GLUT1 pharmacological inhibition against a subset of tumors expressing RB1, thereby identifying RB1 protein level as a biomarker of sensitivity to anti-GLUT1 therapy.

Cancer stem-like cells are the culprits of tumour recurrence and metastasis, but their regulatory mechanisms are not fully understood. Here, the authors show that the scaffold protein SH3RF3 enhances the stem-like properties of breast cancer by facilitating activation of the JNK-JUN pathway and PTX3 expression.

Claudin-low tumors are a rare aggressive subtype of breast cancers. In this study, the authors use a multiomics approach to demonstrate that these tumors are heterogeneous and comprise three main subgroups that emerge from different evolutionary processes.

Acquired resistance to chemotherapy can lead to multi-drug resistance and poor prognosis in cancer. Here, the authors show that Rac1 increases glycolysis and non-oxidative pentose phosphate pathway activity leading to neoadjuvant chemotherapy (NAC) resistance, thus its inhibition sensitizes resistant breast cancer PDXs to NAC.

Local mechanical properties are important to cellular function; but conventional measurement techniques are limited in intact, living, 3D tissues. Here, the authors report on swellable hydrogel microparticles to monitor mechanical properties in situ via a temperature change.

In breast cancer the contribution of different genetic variants to disease heritability is complex and not fully understood. Here, the authors present a network-based analysis in 84,567 patients studying ~7.3 million variants, identifying gene modules associated with breast cancer survival.

Identifying novel therapies for the treatment of CDK4/6 inhibitor-resistant patients is of great importance. Here, the authors demonstrate that PLK1 inhibition is a potential therapeutic target in CCND1-driven and in RB-positive Palbociclib-resistant breast cancers.

Genotoxic agents have been shown to activate the Wnt/β-catenin signaling but the underlying mechanism remains unclear. Here, the authors show that upon DNA damage, the deubiquitinase OTULIN activates Wnt/β-catenin signaling by inhibiting linear ubiquitination, K48-linked polyubiquitination, and proteasomal degradation of β-catenin.

In breast cancer, genome-wide associations studies (GWAS) have highlighted loci associated with disease risk. Here, the authors perform a meta-analysis of GWAS data from Asian populations, discovering 31 potential new risk loci, 10 of which are validated in an independent disease cohort.

Predicting an individual's response to therapy is an important goal for precision medicine. Here, the authors use an algorithm that takes into account the interaction type and directionality of signalling pathways in protein–protein interactions and find that their pathway analysis can predict essential genes, which may be a target for therapy.

Targeting mitochondrial metabolism in cancer cells has shown promising therapeutic potential. Here, the authors screen FDA-approved compound library and show that the β1-blocker nebivolol inhibits oxidative phosphorylation and angiogenesis in cancer cells and can be re-purposed for cancer therapy.

Defects in homologous recombination (HR) are found in some triple negative breast cancers, suggesting they may be sensitive to PARP inhibitors. In this phase II clinical trial of the PARP inhibitor rucaparib, changes in Ki67 levels did not correlate with markers of HR deficiency but HR deficiency was detected in 69% of tumours, indicating that PARP inhibitors may be a useful treatment.

TMBIM6, a member of the transmembrane BI-1 motif-containing family of proteins, is overexpressed in many cancer types. Here, the authors show that TMBIM6 regulates AKT activation through mTORC2 assembly and ribosome association and identify an antagonist of TMBIM6 with anti-tumor properties.

Cancer associated fibroblasts (CAFs) have been suggested to regulate cancer cell metabolism, but the mechanisms are not completely elucidated. Here, the authors show that low FAK expression in stromal cells correlates with poor prognosis in breast and pancreatic cancer patients and that FAK-silencing in CAFs promotes tumourigenesis by the paracrine regulation of cancer cell metabolism.

T cell mediated therapies have proven largely unsuccessful in triple-negative breast cancer (TNBC). Here, the authors show that autophagy is reduced in TNBC, which results in an increase in Tenascin C and reduced activation of tumour infiltrating lymphocytes.

Mechanisms governing adaptation of breast cancer to the brain metastatic microenvironment are unclear. Here, the authors use RNA-sequencing and Drosophila screening to identify Rab11b-mediated endosomal recycling as a unique mechanism for adaptation to a challenging metastatic microenvironment, which can be exploited by repurposing statins.

BRCA1 mutation carriers have higher chances of developing triple-negative breast cancer (TNBC). Here, the authors use the Sleeping Beauty mutagenesis system in Brca1 deficient mice and identify 169 putative driver genes, of which NOTCH1 accelerates TNBC formation through promoting epithelial-mesenchymal transition and cell cycle progression.

Protein synthesis suppression protects breast cancer cells from clinically relevant stresses like hypoxia. Here, the authors show that unique mRNA isoforms that govern stem cell-like phenotypes escape translational repression to drive tumor progression and chemoresistance.