RESUMO
Knudson's "two-hit" paradigm posits that carcinogenesis requires inactivation of both copies of an autosomal tumor suppressor gene. Here, we report that the glycolytic metabolite methylglyoxal (MGO) transiently bypasses Knudson's paradigm by inactivating the breast cancer suppressor protein BRCA2 to elicit a cancer-associated, mutational single-base substitution (SBS) signature in nonmalignant mammary cells or patient-derived organoids. Germline monoallelic BRCA2 mutations predispose to these changes. An analogous SBS signature, again without biallelic BRCA2 inactivation, accompanies MGO accumulation and DNA damage in Kras-driven, Brca2-mutant murine pancreatic cancers and human breast cancers. MGO triggers BRCA2 proteolysis, temporarily disabling BRCA2's tumor suppressive functions in DNA repair and replication, causing functional haploinsufficiency. Intermittent MGO exposure incites episodic SBS mutations without permanent BRCA2 inactivation. Thus, a metabolic mechanism wherein MGO-induced BRCA2 haploinsufficiency transiently bypasses Knudson's two-hit requirement could link glycolysis activation by oncogenes, metabolic disorders, or dietary challenges to mutational signatures implicated in cancer evolution.
Assuntos
Proteína BRCA2 , Neoplasias da Mama , Glicólise , Aldeído Pirúvico , Animais , Proteína BRCA2/metabolismo , Proteína BRCA2/genética , Camundongos , Humanos , Feminino , Aldeído Pirúvico/metabolismo , Neoplasias da Mama/genética , Neoplasias da Mama/metabolismo , Haploinsuficiência , Neoplasias Pancreáticas/metabolismo , Neoplasias Pancreáticas/genética , Neoplasias Pancreáticas/patologia , Mutação , Dano ao DNA , Reparo do DNA , Linhagem Celular TumoralRESUMO
Breast cancer remains a leading cause of cancer-related mortality in women, reflecting profound disease heterogeneity, metastasis, and therapeutic resistance. Over the last decade, genomic and transcriptomic data have been integrated on an unprecedented scale and revealed distinct cancer subtypes, critical molecular drivers, clonal evolutionary trajectories, and prognostic signatures. Furthermore, multi-dimensional integration of high-resolution single-cell and spatial technologies has highlighted the importance of the entire breast cancer ecosystem and the presence of distinct cellular "neighborhoods." Clinically, a plethora of new targeted therapies has emerged, now being rapidly incorporated into routine care. Resistance to therapy, however, remains a crucial challenge for the field.
Assuntos
Neoplasias da Mama , Feminino , Humanos , Neoplasias da Mama/patologia , Neoplasias da Mama/terapia , Perfilação da Expressão Gênica , Genômica , Transcriptoma , Resistencia a Medicamentos AntineoplásicosRESUMO
Ductal carcinoma in situ (DCIS) is a common precursor of invasive breast cancer. Our understanding of its genomic progression to recurrent disease remains poor, partly due to challenges associated with the genomic profiling of formalin-fixed paraffin-embedded (FFPE) materials. Here, we developed Arc-well, a high-throughput single-cell DNA-sequencing method that is compatible with FFPE materials. We validated our method by profiling 40,330 single cells from cell lines, a frozen tissue, and 27 FFPE samples from breast, lung, and prostate tumors stored for 3-31 years. Analysis of 10 patients with matched DCIS and cancers that recurred 2-16 years later show that many primary DCIS had already undergone whole-genome doubling and clonal diversification and that they shared genomic lineages with persistent subclones in the recurrences. Evolutionary analysis suggests that most DCIS cases in our cohort underwent an evolutionary bottleneck, and further identified chromosome aberrations in the persistent subclones that were associated with recurrence.
Assuntos
Neoplasias da Mama , Carcinoma Ductal de Mama , Carcinoma Intraductal não Infiltrante , Feminino , Humanos , Neoplasias da Mama/patologia , Carcinoma Ductal de Mama/genética , Carcinoma Intraductal não Infiltrante/genética , Carcinoma Intraductal não Infiltrante/patologia , Progressão da Doença , Genômica/métodos , Análise da Expressão Gênica de Célula Única , Linhagem Celular TumoralRESUMO
Tumors contain bacteria, but the functional significance of this tumor microbiota is not appreciated. Fu et al. show that bacteria within breast tumor cells contribute to metastasis, in part, by enhancing tumor cell survival to mechanical fluid shear stress as would be found in the circulation.
Assuntos
Bactérias , Neoplasias da Mama , Metástase Neoplásica , Neoplasias da Mama/microbiologia , Neoplasias da Mama/patologia , Sobrevivência Celular , Feminino , Humanos , Estresse MecânicoRESUMO
Tumor-resident intracellular microbiota is an emerging tumor component that has been documented for a variety of cancer types with unclear biological functions. Here, we explored the functional significance of these intratumor bacteria, primarily using a murine spontaneous breast-tumor model MMTV-PyMT. We found that depletion of intratumor bacteria significantly reduced lung metastasis without affecting primary tumor growth. During metastatic colonization, intratumor bacteria carried by circulating tumor cells promoted host-cell survival by enhancing resistance to fluid shear stress by reorganizing actin cytoskeleton. We further showed that intratumor administration of selected bacteria strains isolated from tumor-resident microbiota promoted metastasis in two murine tumor models with significantly different levels of metastasis potential. Our findings suggest that tumor-resident microbiota, albeit at low biomass, play an important role in promoting cancer metastasis, intervention of which might therefore be worth exploring for advancing oncology care.
Assuntos
Neoplasias da Mama , Microbiota , Metástase Neoplásica , Animais , Neoplasias da Mama/microbiologia , Neoplasias da Mama/patologia , Linhagem Celular Tumoral , Feminino , Humanos , Neoplasias Pulmonares/patologia , Camundongos , Células Neoplásicas Circulantes/patologiaRESUMO
Macrophage infiltration is a hallmark of solid cancers, and overall macrophage infiltration correlates with lower patient survival and resistance to therapy. Tumor-associated macrophages, however, are phenotypically and functionally heterogeneous. Specific subsets of tumor-associated macrophage might be endowed with distinct roles on cancer progression and antitumor immunity. Here, we identify a discrete population of FOLR2+ tissue-resident macrophages in healthy mammary gland and breast cancer primary tumors. FOLR2+ macrophages localize in perivascular areas in the tumor stroma, where they interact with CD8+ T cells. FOLR2+ macrophages efficiently prime effector CD8+ T cells ex vivo. The density of FOLR2+ macrophages in tumors positively correlates with better patient survival. This study highlights specific roles for tumor-associated macrophage subsets and paves the way for subset-targeted therapeutic interventions in macrophages-based cancer therapies.
Assuntos
Neoplasias da Mama , Macrófagos , Mama/imunologia , Neoplasias da Mama/epidemiologia , Neoplasias da Mama/imunologia , Linfócitos T CD8-Positivos , Feminino , Receptor 2 de Folato , Humanos , Linfócitos do Interstício Tumoral , PrognósticoRESUMO
X inactivation (XCI) is triggered by upregulation of XIST, which coats the chromosome in cis, promoting formation of a heterochromatic domain (Xi). XIST role beyond initiation of XCI is only beginning to be elucidated. Here, we demonstrate that XIST loss impairs differentiation of human mammary stem cells (MaSCs) and promotes emergence of highly tumorigenic and metastatic carcinomas. On the Xi, XIST deficiency triggers epigenetic changes and reactivation of genes overlapping Polycomb domains, including Mediator subunit MED14. MED14 overdosage results in increased Mediator levels and hyperactivation of the MaSC enhancer landscape and transcriptional program, making differentiation less favorable. We further demonstrate that loss of XIST and Xi transcriptional instability is common among human breast tumors of poor prognosis. We conclude that XIST is a gatekeeper of human mammary epithelium homeostasis, thus unveiling a paradigm in the control of somatic cell identity with potential consequences for our understanding of gender-specific malignancies.
Assuntos
Complexo Mediador/metabolismo , Células-Tronco Neoplásicas/metabolismo , RNA Longo não Codificante/metabolismo , Neoplasias da Mama/metabolismo , Diferenciação Celular , Epigênese Genética , Humanos , RNA Longo não Codificante/genética , Inativação do Cromossomo XRESUMO
Ductal carcinoma in situ (DCIS) is a pre-invasive lesion that is thought to be a precursor to invasive breast cancer (IBC). To understand the changes in the tumor microenvironment (TME) accompanying transition to IBC, we used multiplexed ion beam imaging by time of flight (MIBI-TOF) and a 37-plex antibody staining panel to interrogate 79 clinically annotated surgical resections using machine learning tools for cell segmentation, pixel-based clustering, and object morphometrics. Comparison of normal breast with patient-matched DCIS and IBC revealed coordinated transitions between four TME states that were delineated based on the location and function of myoepithelium, fibroblasts, and immune cells. Surprisingly, myoepithelial disruption was more advanced in DCIS patients that did not develop IBC, suggesting this process could be protective against recurrence. Taken together, this HTAN Breast PreCancer Atlas study offers insight into drivers of IBC relapse and emphasizes the importance of the TME in regulating these processes.
Assuntos
Neoplasias da Mama/patologia , Carcinoma Intraductal não Infiltrante/patologia , Diferenciação Celular , Estudos de Coortes , Progressão da Doença , Células Epiteliais/patologia , Epitélio/patologia , Matriz Extracelular/metabolismo , Feminino , Fibroblastos/metabolismo , Fibroblastos/patologia , Humanos , Pessoa de Meia-Idade , Invasividade Neoplásica , Recidiva Local de Neoplasia/patologia , Fenótipo , Análise de Célula Única , Células Estromais/patologia , Microambiente TumoralRESUMO
B cells and T cells are important components of the adaptive immune system and mediate anticancer immunity. The T cell landscape in cancer is well characterized, but the contribution of B cells to anticancer immunosurveillance is less well explored. Here we show an integrative analysis of the B cell and T cell receptor repertoire from individuals with metastatic breast cancer and individuals with early breast cancer during neoadjuvant therapy. Using immune receptor, RNA and whole-exome sequencing, we show that both B cell and T cell responses seem to coevolve with the metastatic cancer genomes and mirror tumor mutational and neoantigen architecture. B cell clones associated with metastatic immunosurveillance and temporal persistence were more expanded and distinct from site-specific clones. B cell clonal immunosurveillance and temporal persistence are predictable from the clonal structure, with higher-centrality B cell antigen receptors more likely to be detected across multiple metastases or across time. This predictability was generalizable across other immune-mediated disorders. This work lays a foundation for prioritizing antibody sequences for therapeutic targeting in cancer.
Assuntos
Linfócitos B , Neoplasias da Mama , Vigilância Imunológica , Humanos , Feminino , Neoplasias da Mama/imunologia , Linfócitos B/imunologia , Receptores de Antígenos de Linfócitos T/genética , Receptores de Antígenos de Linfócitos T/imunologia , Receptores de Antígenos de Linfócitos T/metabolismo , Receptores de Antígenos de Linfócitos B/metabolismo , Receptores de Antígenos de Linfócitos B/genética , Receptores de Antígenos de Linfócitos B/imunologia , Linfócitos T/imunologia , Monitorização Imunológica , Sequenciamento do Exoma , Antígenos de Neoplasias/imunologia , Metástase Neoplásica , Células ClonaisRESUMO
The nuclear hormone receptor estrogen receptor alpha (ERα) is a well-known transcription factor present in many breast cancers, where it promotes cancer progression. In this issue of Cell, Xu et al. report that ERα is also an RNA-binding protein and that its post-transcriptional activity enables cancer cell fitness and survival.
Assuntos
Neoplasias da Mama , Receptores de Estrogênio , Neoplasias da Mama/genética , Linhagem Celular Tumoral , Proliferação de Células , Receptor alfa de Estrogênio/genética , Feminino , Humanos , RNA/genética , Receptores de Estrogênio/genéticaRESUMO
Mary-Claire King's approach to genetics has had a major impact on breast and ovarian cancer and, more recently, mental illnesses including schizophrenia. Science writer Kendall Morgan talked with Mary-Claire, recipient of a 2021 Canada Gairdner International Award, about her life, her lengthy quest to discover the genetic basis of susceptibility to breast cancer, the struggles for women in science, and much more. An edited version of this conversation is presented below.
Assuntos
Neoplasias da Mama/patologia , Neoplasias Ovarianas/patologia , Distinções e Prêmios , Neoplasias da Mama/genética , Feminino , Genética , Humanos , Transtornos Mentais/genética , Transtornos Mentais/patologia , Neoplasias Ovarianas/genética , Esquizofrenia/genética , Esquizofrenia/patologiaRESUMO
Although mutations leading to a compromised nuclear envelope cause diseases such as muscular dystrophies or accelerated aging, the consequences of mechanically induced nuclear envelope ruptures are less known. Here, we show that nuclear envelope ruptures induce DNA damage that promotes senescence in non-transformed cells and induces an invasive phenotype in human breast cancer cells. We find that the endoplasmic reticulum (ER)-associated exonuclease TREX1 translocates into the nucleus after nuclear envelope rupture and is required to induce DNA damage. Inside the mammary duct, cellular crowding leads to nuclear envelope ruptures that generate TREX1-dependent DNA damage, thereby driving the progression of in situ carcinoma to the invasive stage. DNA damage and nuclear envelope rupture markers were also enriched at the invasive edge of human tumors. We propose that DNA damage in mechanically challenged nuclei could affect the pathophysiology of crowded tissues by modulating proliferation and extracellular matrix degradation of normal and transformed cells.
Assuntos
Neoplasias da Mama/enzimologia , Neoplasias da Mama/patologia , Dano ao DNA , Exodesoxirribonucleases/metabolismo , Membrana Nuclear/metabolismo , Fosfoproteínas/metabolismo , Animais , Linhagem Celular , Senescência Celular , Colágeno/metabolismo , Progressão da Doença , Feminino , Humanos , Camundongos , Invasividade Neoplásica , Membrana Nuclear/ultraestrutura , Proteólise , Ensaios Antitumorais Modelo de XenoenxertoRESUMO
Metastasis has been considered as the terminal step of tumor progression. However, recent genomic studies suggest that many metastases are initiated by further spread of other metastases. Nevertheless, the corresponding pre-clinical models are lacking, and underlying mechanisms are elusive. Using several approaches, including parabiosis and an evolving barcode system, we demonstrated that the bone microenvironment facilitates breast and prostate cancer cells to further metastasize and establish multi-organ secondary metastases. We uncovered that this metastasis-promoting effect is driven by epigenetic reprogramming that confers stem cell-like properties on cancer cells disseminated from bone lesions. Furthermore, we discovered that enhanced EZH2 activity mediates the increased stemness and metastasis capacity. The same findings also apply to single cell-derived populations, indicating mechanisms distinct from clonal selection. Taken together, our work revealed an unappreciated role of the bone microenvironment in metastasis evolution and elucidated an epigenomic reprogramming process driving terminal-stage, multi-organ metastases.
Assuntos
Neoplasias Ósseas/secundário , Neoplasias da Mama/patologia , Metástase Neoplásica , Neoplasias da Próstata/patologia , Microambiente Tumoral , Animais , Apoptose , Biomarcadores Tumorais/genética , Biomarcadores Tumorais/metabolismo , Neoplasias Ósseas/genética , Neoplasias Ósseas/metabolismo , Neoplasias da Mama/genética , Neoplasias da Mama/metabolismo , Proliferação de Células , Progressão da Doença , Feminino , Perfilação da Expressão Gênica , Regulação Neoplásica da Expressão Gênica , Humanos , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Endogâmicos NOD , Camundongos Nus , Camundongos SCID , Neoplasias da Próstata/genética , Neoplasias da Próstata/metabolismo , Células Tumorais Cultivadas , Ensaios Antitumorais Modelo de XenoenxertoRESUMO
Estrogen receptor α (ERα) is a hormone receptor and key driver for over 70% of breast cancers that has been studied for decades as a transcription factor. Unexpectedly, we discover that ERα is a potent non-canonical RNA-binding protein. We show that ERα RNA binding function is uncoupled from its activity to bind DNA and critical for breast cancer progression. Employing genome-wide cross-linking immunoprecipitation (CLIP) sequencing and a functional CRISPRi screen, we find that ERα-associated mRNAs sustain cancer cell fitness and elicit cellular responses to stress. Mechanistically, ERα controls different steps of RNA metabolism. In particular, we demonstrate that ERα RNA binding mediates alternative splicing of XBP1 and translation of the eIF4G2 and MCL1 mRNAs, which facilitates survival upon stress conditions and sustains tamoxifen resistance of cancer cells. ERα is therefore a multifaceted RNA-binding protein, and this activity transforms our knowledge of post-transcriptional regulation underlying cancer development and drug response.
Assuntos
Neoplasias da Mama/metabolismo , Neoplasias da Mama/patologia , Resistencia a Medicamentos Antineoplásicos , Receptor alfa de Estrogênio/metabolismo , Proteínas de Ligação a RNA/metabolismo , Animais , Sequência de Bases , Neoplasias da Mama/genética , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Sobrevivência Celular/genética , Progressão da Doença , Resistencia a Medicamentos Antineoplásicos/efeitos dos fármacos , Resistencia a Medicamentos Antineoplásicos/genética , Receptor alfa de Estrogênio/química , Fator de Iniciação Eucariótico 4G/genética , Fator de Iniciação Eucariótico 4G/metabolismo , Feminino , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Genômica , Humanos , Camundongos Endogâmicos NOD , Proteína de Sequência 1 de Leucemia de Células Mieloides/genética , Proteína de Sequência 1 de Leucemia de Células Mieloides/metabolismo , Oncogenes , Ligação Proteica/efeitos dos fármacos , Domínios Proteicos , Splicing de RNA/genética , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Estresse Fisiológico/efeitos dos fármacos , Estresse Fisiológico/genética , Tamoxifeno/farmacologia , Proteína 1 de Ligação a X-Box/metabolismoRESUMO
Ras GTPase-activating protein-binding proteins 1 and 2 (G3BP1 and G3BP2, respectively) are widely recognized as core components of stress granules (SGs). We report that G3BPs reside at the cytoplasmic surface of lysosomes. They act in a non-redundant manner to anchor the tuberous sclerosis complex (TSC) protein complex to lysosomes and suppress activation of the metabolic master regulator mechanistic target of rapamycin complex 1 (mTORC1) by amino acids and insulin. Like the TSC complex, G3BP1 deficiency elicits phenotypes related to mTORC1 hyperactivity. In the context of tumors, low G3BP1 levels enhance mTORC1-driven breast cancer cell motility and correlate with adverse outcomes in patients. Furthermore, G3bp1 inhibition in zebrafish disturbs neuronal development and function, leading to white matter heterotopia and neuronal hyperactivity. Thus, G3BPs are not only core components of SGs but also a key element of lysosomal TSC-mTORC1 signaling.
Assuntos
Proteínas Adaptadoras de Transdução de Sinal/metabolismo , DNA Helicases/metabolismo , Lisossomos/metabolismo , Alvo Mecanístico do Complexo 1 de Rapamicina/metabolismo , Proteínas de Ligação a Poli-ADP-Ribose/metabolismo , RNA Helicases/metabolismo , Proteínas com Motivo de Reconhecimento de RNA/metabolismo , Proteínas de Ligação a RNA/metabolismo , Transdução de Sinais , Esclerose Tuberosa/metabolismo , Sequência de Aminoácidos , Animais , Neoplasias da Mama/metabolismo , Neoplasias da Mama/patologia , Linhagem Celular Tumoral , Movimento Celular/efeitos dos fármacos , Grânulos Citoplasmáticos/efeitos dos fármacos , Grânulos Citoplasmáticos/metabolismo , DNA Helicases/química , Evolução Molecular , Feminino , Humanos , Insulina/farmacologia , Proteínas de Membrana Lisossomal/metabolismo , Lisossomos/efeitos dos fármacos , Neurônios/efeitos dos fármacos , Neurônios/metabolismo , Fenótipo , Proteínas de Ligação a Poli-ADP-Ribose/química , RNA Helicases/química , Proteínas com Motivo de Reconhecimento de RNA/química , Ratos Wistar , Transdução de Sinais/efeitos dos fármacos , Peixe-Zebra/metabolismoRESUMO
The integration of mass spectrometry-based proteomics with next-generation DNA and RNA sequencing profiles tumors more comprehensively. Here this "proteogenomics" approach was applied to 122 treatment-naive primary breast cancers accrued to preserve post-translational modifications, including protein phosphorylation and acetylation. Proteogenomics challenged standard breast cancer diagnoses, provided detailed analysis of the ERBB2 amplicon, defined tumor subsets that could benefit from immune checkpoint therapy, and allowed more accurate assessment of Rb status for prediction of CDK4/6 inhibitor responsiveness. Phosphoproteomics profiles uncovered novel associations between tumor suppressor loss and targetable kinases. Acetylproteome analysis highlighted acetylation on key nuclear proteins involved in the DNA damage response and revealed cross-talk between cytoplasmic and mitochondrial acetylation and metabolism. Our results underscore the potential of proteogenomics for clinical investigation of breast cancer through more accurate annotation of targetable pathways and biological features of this remarkably heterogeneous malignancy.
Assuntos
Neoplasias da Mama/genética , Neoplasias da Mama/patologia , Carcinogênese/genética , Carcinogênese/patologia , Terapia de Alvo Molecular , Proteogenômica , Desaminases APOBEC/metabolismo , Adulto , Idoso , Idoso de 80 Anos ou mais , Neoplasias da Mama/imunologia , Neoplasias da Mama/terapia , Estudos de Coortes , Dano ao DNA , Reparo do DNA , Feminino , Humanos , Imunoterapia , Metabolômica , Pessoa de Meia-Idade , Mutagênese/genética , Fosforilação , Inibidores de Proteínas Quinases/farmacologia , Proteínas Quinases/metabolismo , Receptor ErbB-2/metabolismo , Proteína do Retinoblastoma/metabolismo , Microambiente Tumoral/imunologiaRESUMO
Cancer therapies kill tumors either directly or indirectly by evoking immune responses and have been combined with varying levels of success. Here, we describe a paradigm to control cancer growth that is based on both direct tumor killing and the triggering of protective immunity. Genetic ablation of serine protease inhibitor SerpinB9 (Sb9) results in the death of tumor cells in a granzyme B (GrB)-dependent manner. Sb9-deficient mice exhibited protective T cell-based host immunity to tumors in association with a decline in GrB-expressing immunosuppressive cells within the tumor microenvironment (TME). Maximal protection against tumor development was observed when the tumor and host were deficient in Sb9. The therapeutic utility of Sb9 inhibition was demonstrated by the control of tumor growth, resulting in increased survival times in mice. Our studies describe a molecular target that permits a combination of tumor ablation, interference within the TME, and immunotherapy in one potential modality.
Assuntos
Citotoxicidade Imunológica , Imunoterapia , Proteínas de Membrana/metabolismo , Neoplasias/imunologia , Neoplasias/terapia , Serpinas/metabolismo , Animais , Apoptose/efeitos dos fármacos , Neoplasias da Mama/imunologia , Neoplasias da Mama/patologia , Neoplasias da Mama/terapia , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Citotoxicidade Imunológica/efeitos dos fármacos , Progressão da Doença , Feminino , Deleção de Genes , Granzimas/metabolismo , Imunidade/efeitos dos fármacos , Melanoma/patologia , Camundongos Endogâmicos C57BL , Neoplasias/prevenção & controle , Bibliotecas de Moléculas Pequenas/farmacologia , Células Estromais/efeitos dos fármacos , Células Estromais/patologia , Microambiente Tumoral/efeitos dos fármacosRESUMO
Collective metastasis is defined as the cohesive migration and metastasis of multicellular tumor cell clusters. Disrupting various cell adhesion genes markedly reduces cluster formation and colonization efficiency, yet the downstream signals transmitted by clustering remain largely unknown. Here, we use mouse and human breast cancer models to identify a collective signal generated by tumor cell clusters supporting metastatic colonization. We show that tumor cell clusters produce the growth factor epigen and concentrate it within nanolumina-intercellular compartments sealed by cell-cell junctions and lined with microvilli-like protrusions. Epigen knockdown profoundly reduces metastatic outgrowth and switches clusters from a proliferative to a collective migratory state. Tumor cell clusters from basal-like 2, but not mesenchymal-like, triple-negative breast cancer cell lines have increased epigen expression, sealed nanolumina, and impaired outgrowth upon nanolumenal junction disruption. We propose that nanolumenal signaling could offer a therapeutic target for aggressive metastatic breast cancers.
Assuntos
Neoplasias da Mama/fisiopatologia , Junções Intercelulares/patologia , Metástase Neoplásica/fisiopatologia , Animais , Adesão Celular/fisiologia , Linhagem Celular Tumoral , Movimento Celular/fisiologia , Epigen/metabolismo , Transição Epitelial-Mesenquimal/genética , Humanos , Camundongos , Células Neoplásicas Circulantes/patologia , Transdução de Sinais/fisiologia , Neoplasias de Mama Triplo Negativas/patologiaRESUMO
Understanding molecular mechanisms that dictate B cell diversity is important for targeting B cells as anti-cancer treatment. Through the single-cell dissection of B cell heterogeneity in longitudinal samples of patients with breast cancer before and after neoadjuvant chemotherapy, we revealed that an ICOSL+ B cell subset emerges after chemotherapy. Using three immunocompetent mouse models, we recapitulated the subset switch of human tumor-infiltrating B cells during chemotherapy. By employing B-cell-specific deletion mice, we showed that ICOSL in B cells boosts anti-tumor immunity by enhancing the effector to regulatory T cell ratio. The signature of ICOSL+ B cells is imprinted by complement-CR2 signaling, which is triggered by immunogenic cell death. Moreover, we identified that CD55, a complement inhibitory protein, determines the opposite roles of B cells in chemotherapy. Collectively, we demonstrated a critical role of the B cell subset switch in chemotherapy response, which has implications in designing novel anti-cancer therapies. VIDEO ABSTRACT.
Assuntos
Linfócitos B/imunologia , Neoplasias da Mama/imunologia , Ligante Coestimulador de Linfócitos T Induzíveis/metabolismo , Animais , Antineoplásicos/metabolismo , Linfócitos B/metabolismo , Antígenos CD55/imunologia , Antígenos CD55/metabolismo , Linhagem Celular Tumoral , Proteínas do Sistema Complemento/metabolismo , Modelos Animais de Doenças , Feminino , Humanos , Ligante Coestimulador de Linfócitos T Induzíveis/imunologia , Linfócitos do Interstício Tumoral/imunologia , Camundongos , Camundongos Endogâmicos C57BL , Receptores de Complemento 3d/imunologia , Receptores de Complemento 3d/metabolismo , Transdução de Sinais/imunologia , Linfócitos T Reguladores/imunologiaRESUMO
Mutations in the BRCA1 and BRCA2 genes predispose afflicted individuals to breast, ovarian, and other cancers. The BRCA-encoded products form complexes with other tumor suppressor proteins and with the recombinase enzyme RAD51 to mediate chromosome damage repair by homologous recombination and also to protect stressed DNA replication forks against spurious nucleolytic attrition. Understanding how the BRCA tumor suppressor network executes its biological functions would provide the foundation for developing targeted cancer therapeutics, but progress in this area has been greatly hampered by the challenge of obtaining purified BRCA complexes for mechanistic studies. In this article, we review how recent effort begins to overcome this technical challenge, leading to functional and structural insights into the biochemical attributes of these complexes and the multifaceted roles that they fulfill in genome maintenance. We also highlight the major mechanistic questions that remain.