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138 result(s) for "Vacher, Sophie"
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High AHR expression in breast tumors correlates with expression of genes from several signaling pathways namely inflammation and endogenous tryptophan metabolism
Increasing epidemiological and animal experimental data provide substantial support for the role of aryl hydrocarbon receptor (AhR) in mammary tumorigenesis. The effects of AhR have been clearly demonstrated in rodent models of breast carcinogenesis and in several established human breast cancer cell lines following exposure to AhR ligands or AhR overexpression. However, relatively little is known about the role of AhR in human breast cancers. AhR has always been considered to be a regulator of toxic and carcinogenic responses to environmental contaminants such as TCDD (dioxin) and benzo[a]pyrene (BaP). The aim of this study was to identify the type of breast tumors (ERα-positive or ERα-negative) that express AHR and how AhR affects human tumorigenesis. The levels of AHR, AHR nuclear translocator (ARNT) and AHR repressor (AHRR) mRNA expression were analyzed in a cohort of 439 breast tumors, demonstrating a weak association between high AHR expression and age greater than fifty years and ERα-negative status, and HR-/ERBB2 breast cancer subtypes. AHRR mRNA expression was associated with metastasis-free survival, while AHR mRNA expression was not. Immunohistochemistry revealed the presence of AhR protein in both tumor cells (nucleus and/or cytoplasm) and the tumor microenvironment (including endothelial cells and lymphocytes). High AHR expression was correlated with high expression of several genes involved in signaling pathways related to inflammation (IL1B, IL6, TNF, IL8 and CXCR4), metabolism (IDO1 and TDO2 from the kynurenine pathway), invasion (MMP1, MMP2 and PLAU), and IGF signaling (IGF2R, IGF1R and TGFB1). Two well-known ligands for AHR (TCDD and BaP) induced mRNA expression of IL1B and IL6 in an ERα-negative breast tumor cell line. The breast cancer ER status likely influences AhR activity involved in these signaling pathways. The mechanisms involved in AhR activation and target gene expression in breast cancers are also discussed.
Prognostic value of intratumoral Fusobacterium nucleatum and association with immune-related gene expression in oral squamous cell carcinoma patients
Changes in the oral microbiome, particularly Fusobacterium nucleatum , are associated with oral squamous cell carcinoma (OSCC). F. nucleatum has been reported to modulate local immunity in cancers. We aimed to assess the association between intratumoral F. nucleatum and clinico-pathological features, relapse, and overall survival (OS) in two independent cohorts of patients with OSCC, and to explore the interplay with immune-related genes. We retrospectively analyzed tissue samples from a first cohort of 122 patients with head and neck squamous cell carcinoma, including 61 OSCC (cohort #1), and a second cohort of 90 additional OSCC (cohort #2). We then performed a sensitivity analysis on the merged cohort of OSCC patients (N = 151). F. nucleatum 16S rRNA gene sequences were quantified using real-time quantitative PCR. The presence of gram-negative bacteria and macrophages was confirmed by LPS and CD163 immunostainings, respectively. F. nucleatum positivity was associated with older age, less alcohol and combined alcohol plus tobacco consumption, and less frequent lymph node invasion. There was a trend for a lower recurrence rate in F. nucleatum -positive cases, with less metastatic relapses compared to F. nucleatum -negative tumors, and significantly longer OS, relapse-free and metastasis-free survival. F. nucleatum status was independently associated with OS in multivariate analysis. Immune-related gene and immunohistochemistry analyses showed that gram-negative bacteria load inversely correlated with M2 macrophages. F. nucleatum -associated OSCC has a specific immune microenvironment, is more frequent in older, non-drinking patients, and associated with a favorable prognosis.
Oxidative phosphorylation is a metabolic vulnerability of endocrine therapy and palbociclib resistant metastatic breast cancers
Resistance to endocrine treatments and CDK4/6 inhibitors is considered a near-inevitability in most patients with estrogen receptor positive breast cancers (ER + BC). By genomic and metabolomics analyses of patients’ tumours, metastasis-derived patient-derived xenografts (PDX) and isogenic cell lines we demonstrate that a fraction of metastatic ER + BC is highly reliant on oxidative phosphorylation (OXPHOS). Treatment by the OXPHOS inhibitor IACS-010759 strongly inhibits tumour growth in multiple endocrine and palbociclib resistant PDX. Mutations in the PIK3CA / AKT1 genes are significantly associated with response to IACS-010759. At the metabolic level, in vivo response to IACS-010759 is associated with decreased levels of metabolites of the glutathione, glycogen and pentose phosphate pathways in treated tumours. In vitro, endocrine and palbociclib resistant cells show increased OXPHOS dependency and increased ROS levels upon IACS-010759 treatment. Finally, in ER + BC patients, high expression of OXPHOS associated genes predict poor prognosis. In conclusion, these results identify OXPHOS as a promising target for treatment resistant ER + BC patients. Patients with estrogen receptor positive breast cancer (ER + BC) treated with palbociclib (CDK4/6 inhibitor) frequently develop resistance. Here, the authors identify a reliance of palbociclib resistance on oxidative phosphorylation (OXPHOS) and therapeutically target this vulnerability using an OXPHOS inhibitor, restoring sensitivity in ER + BC preclinical models.
Nivolumab plus chemoradiotherapy in locally-advanced cervical cancer: the NICOL phase 1 trial
Concurrent chemoradiotherapy (CRT) with blockade of the PD-1 pathway may enhance immune-mediated tumor control through increased phagocytosis, cell death, and antigen presentation. The NiCOL phase 1 trial (NCT03298893) is designed to determine the safety/tolerance profile and the recommended phase-II dose of nivolumab with and following concurrent CRT in 16 women with locally advanced cervical cancer. Secondary endpoints include objective response rate (ORR), progression free survival (PFS), disease free survival, and immune correlates of response. Three patients experience grade 3 dose-limiting toxicities. The pre-specified endpoints are met, and overall response rate is 93.8% [95%CI: 69.8–99.8%] with a 2-year PFS of 75% [95% CI: 56.5–99.5%]. Compared to patients with progressive disease (PD), progression-free (PF) subjects show a brisker stromal immune infiltrate, higher proximity of tumor-infiltrating CD3 + T cells to PD-L1 + tumor cells and of FOXP3 + T cells to proliferating CD11c + myeloid cells. PF show higher baseline levels of PD-1 and ICOS-L on tumor-infiltrating EMRA CD4 + T cells and tumor-associated macrophages, respectively; PD instead, display enhanced PD-L1 expression on TAMs, higher peripheral frequencies of proliferating Tregs at baseline and higher PD-1 levels at week 6 post-treatment initiation on CD4 and CD8 T cell subsets. Concomitant nivolumab plus definitive CRT is safe and associated with encouraging PFS rates. Further validation in the subset of locally advanced cervical cancer displaying pre-existing, adaptive immune activation is warranted. A combination of chemoradiotherapy followed by brachytherapy is recommended for patients with locally-advanced cervical cancer (LACC), however there is still a high risk of disease recurrence. Here the authors report clinical outcomes and immunologic correlates of a clinical trial of the PD-1 inhibitor nivolumab in combination with chemoradiotherapy in LACC patients.
Targeted next-generation sequencing identifies clinically relevant somatic mutations in a large cohort of inflammatory breast cancer
Background Inflammatory breast cancer (IBC) is the most aggressive form of primary breast cancer. Using a custom-made breast cancer gene sequencing panel, we investigated somatic mutations in IBC to better understand the genomic differences compared with non-IBC and to consider new targeted therapy in IBC patients. Methods Targeted next-generation sequencing (NGS) of 91 candidate breast cancer-associated genes was performed on 156 fresh-frozen breast tumor tissues from IBC patients. Mutational profiles from 197 primary breast tumors from The Cancer Genome Atlas (TCGA) were used as non-IBC controls for comparison analysis. The mutational landscape of IBC was correlated with clinicopathological data and outcomes. Results After genotype calling and algorithmic annotations, we identified 392 deleterious variants in IBC and 320 variants in non-IBC cohorts, respectively. IBC tumors harbored more mutations than non-IBC (2.5 per sample vs. 1.6 per sample, p  < 0.0001). Eighteen mutated genes were significantly different between the two cohorts, namely TP53 , CDH1 , NOTCH2 , MYH9 , BRCA2 , ERBB4 , POLE , FGFR3 , ROS1 , NOTCH4 , LAMA2 , EGFR , BRCA1 , TP53BP1 , ESR1 , THBS1 , CASP8 , and NOTCH1 . In IBC, the most frequently mutated genes were TP53 (43.0%), PIK3CA (29.5%), MYH9 (8.3%), NOTCH2 (8.3%), BRCA2 (7.7%), ERBB4 (7.1%), FGFR3 (6.4%), POLE (6.4%), LAMA2 (5.8%), ARID1A (5.1%), NOTCH4 (5.1%), and ROS1 (5.1%). After grouping 91 genes on 10 signaling pathways, we found that the DNA repair pathway for the triple-negative breast cancer (TNBC) subgroup, the RTK/RAS/MAPK and cell cycle pathways for the HR – /HER2 + subgroup, the DNA repair, RTK/RAS/MAPK, and NOTCH pathways for the HR + /HER2 – subgroup, and the DNA repair, epigenome, and diverse pathways for the HR + /HER2 + subgroup were all significantly differently altered between IBC and non-IBC. PIK3CA mutation was independently associated with worse metastasis-free survival (MFS) in IBC since the median MFS for the PIK3CA mutant type was 26.0 months and for the PIK3CA wild type was 101.1 months ( p  = 0.002). This association was observed in TNBC ( p  = 0.04) and the HR – /HER2 + subgroups ( p  = 0.0003), but not in the HR + /HER2 – subgroup of IBC. Conclusions Breast cancer-specific targeted NGS uncovered a high frequency of deleterious somatic mutations in IBC, some of which may be relevant for clinical management.
Cortical branched actin determines cell cycle progression
The actin cytoskeleton generates and senses forces. Here we report that branched actin networks from the cell cortex depend on ARPC1B-containing Arp2/3 complexes and that they are specifically monitored by type I coronins to control cell cycle progression in mammary epithelial cells. Cortical ARPC1B-dependent branched actin networks are regulated by the RAC1/WAVE/ARPIN pathway and drive lamellipodial protrusions. Accordingly, we uncover that the duration of the G1 phase scales with migration persistence in single migrating cells. Moreover, cortical branched actin more generally determines S-phase entry by integrating soluble stimuli such as growth factors and mechanotransduction signals, ensuing from substratum rigidity or stretching of epithelial monolayers. Many tumour cells lose this dependence for cortical branched actin. But the RAC1-transformed tumour cells stop cycling upon Arp2/3 inhibition. Among all genes encoding Arp2/3 subunits, ARPC1B overexpression in tumours is associated with the poorest metastasis-free survival in breast cancer patients. Arp2/3 specificity may thus provide diagnostic and therapeutic opportunities in cancer.
ETV4 transcription factor and MMP13 metalloprotease are interplaying actors of breast tumorigenesis
Background The ETS transcription factor ETV4 is involved in the main steps of organogenesis and is also a significant mediator of tumorigenesis and metastasis, such as in breast cancer. Indeed, ETV4 is overexpressed in breast tumors and is associated with distant metastasis and poor prognosis. However, the cellular and molecular events regulated by this factor are still misunderstood. In mammary epithelial cells, ETV4 controls the expression of many genes, MMP13 among them. The aim of this study was to understand the function of MMP13 during ETV4-driven tumorigenesis. Methods Different constructs of the MMP13 gene promoter were used to study the direct regulation of MMP13 by ETV4. Moreover, cell proliferation, migration, invasion, anchorage-independent growth, and in vivo tumorigenicity were assayed using models of mammary epithelial and cancer cells in which the expression of MMP13 and/or ETV4 is modulated. Importantly, the expression of MMP13 and ETV4 messenger RNA was characterized in 456 breast cancer samples. Results Our results revealed that ETV4 promotes proliferation, migration, invasion, and anchorage-independent growth of the MMT mouse mammary tumorigenic cell line. By investigating molecular events downstream of ETV4, we found that MMP13, an extracellular metalloprotease, was an ETV4 target gene. By overexpressing or repressing MMP13, we showed that this metalloprotease contributes to proliferation, migration, and anchorage-independent clonogenicity. Furthermore, we demonstrated that MMP13 inhibition disturbs proliferation, migration, and invasion induced by ETV4 and participates to ETV4-induced tumor formation in immunodeficient mice. Finally, ETV4 and MMP13 co-overexpression is associated with poor prognosis in breast cancer. Conclusion MMP13 potentiates the effects of the ETV4 oncogene during breast cancer genesis and progression.
A clustering-stratified cross-validation framework for validating omics survival models: application to head and neck cancer
Background This study tackles the challenge of developing reliable prognostic models for time-to-event (TTE) outcomes using high-dimensional omics data in head and neck cancers. Resampling methods, particularly nested cross-validation, are considered as standard for model hyperparameter selection and performance evaluation. When handling clustered data, balancing the random partition of the cross-validation folds to minimize optimism bias and instability could be tested. This work compares the performance of three nested cross-validation implementations, including random assignment of the folds, clustering-based resampling, and internal-external validation using an hold out approach. Method We analyzed two head and neck squamous cell carcinoma (HNSCC) cohorts: The Cancer Genome Atlas (TCGA) and SCANDARE (NCT03017573), with clinical data and transcriptomic data normalized as log-transcripts per million. Three model selection methods LASSO, IPF-Lasso, and Priority-LASSO were evaluated within five nested cross-validation frameworks: Standard nested cross-validation, Clustering-based nested-cross validation, nested-cross validation with Combat correction, Nested cross-validation for optimization combined with hold-out for validation, Nested cross-validation for optimization combined with hold-out and ComBat correction for validation. Predictive performance was assessed using 3-year AUC and Integrated Brier Score (IBS). Results We analyzed data from 581 patients (mean age 61.0 years, 33.6% female) across TCGA-HNSC ( n  = 505) and SCANDARE ( n  = 76). Clustering analyses, using UMAP and k-means, identified three transcriptomic clusters. Validation strategies demonstrated reduced instability for Lasso ( p  < 0.001), IPF-Lasso ( p  < 0.001) and Priority-lasso ( p  < 0.001) without apparent optimism in discrimination and calibration metrics with stratified nested cross-validation (SNCV), supporting its utility. As an application using IPF-Lasso Cox models with SNCV, we integrated clinical and transcriptomic data, selecting 35 prognosis variables of head and neck carcinomas. This model achieved a 3-year AUC of 0.71 and IBS of 0.08. Conclusion Clustering-based nested cross-validation combined with stratified cross-validation offers a robust compromise for developing high-dimensional survival models and evaluating their predictive performance. This approach leverages clustering-derived stratification to balance heterogeneity in the dataset within cross-validation folds, although the training and test sets remain derived from the pooled dataset rather than fully independent cohorts.
Metastasis-suppressor NME1 controls the invasive switch of breast cancer by regulating MT1-MMP surface clearance
Membrane Type 1 Matrix Metalloprotease (MT1-MMP) contributes to the invasive progression of breast cancers by degrading extracellular matrix tissues. Nucleoside diphosphate kinase, NME1/NM23-H1, has been identified as a metastasis suppressor; however, its contribution to local invasion in breast cancer is not known. Here, we report that NME1 is up-regulated in ductal carcinoma in situ (DCIS) as compared to normal breast epithelial tissues. NME1 levels drop in microinvasive and invasive components of breast tumor cells relative to synchronous DCIS foci. We find a strong anti-correlation between NME1 and plasma membrane MT1-MMP levels in the invasive components of breast tumors, particularly in aggressive histological grade III and triple-negative breast cancers. Knockout of NME1 accelerates the invasive transition of breast tumors in the intraductal xenograft model. At the mechanistic level, we find that MT1-MMP, NME1 and dynamin-2, a GTPase known to require GTP production by NME1 for its membrane fission activity in the endocytic pathway, interact in clathrin-coated vesicles at the plasma membrane. Loss of NME1 function increases MT1-MMP surface levels by inhibiting endocytic clearance. As a consequence, the ECM degradation and invasive potentials of breast cancer cells are enhanced. This study identifies the down-modulation of NME1 as a potent driver of the in situ-to invasive transition during breast cancer progression.
Coronin 1C promotes triple-negative breast cancer invasiveness through regulation of MT1-MMP traffic and invadopodia function
Membrane type 1-matrix metalloproteinase (MT1-MMP), a membrane-tethered protease, is key for matrix breakdown during cancer invasion and metastasis. Assembly of branched actin networks by the Arp2/3 complex is required for MT1-MMP traffic and formation of matrix-degradative invadopodia. Contrasting with the well-established role of actin filament branching factor cortactin in invadopodia function during cancer cell invasion, the contribution of coronin-family debranching factors to invadopodia-based matrix remodeling is not known. Here, we investigated the contribution of coronin 1C to the invasive potential of breast cancer cells. We report that expression of coronin 1C is elevated in invasive human breast cancers, correlates positively with MT1-MMP expression in relation with increased metastatic risk and is a new independent prognostic factor in breast cancer. We provide evidence that, akin to cortactin, coronin 1C is required for invadopodia formation and matrix degradation by breast cancer cells lines and for 3D collagen invasion by multicellular spheroids. Using intravital imaging of orthotopic human breast tumor xenografts, we find that coronin 1C accumulates in structures forming in association with collagen fibrils in the tumor microenvironment. Moreover, we establish the role of coronin 1C in the regulation of positioning and trafficking of MT1-MMP-positive endolysosomes. These results identify coronin 1C as a novel player of the multi-faceted mechanism responsible for invadopodia formation, MT1-MMP surface exposure and invasiveness in breast cancer cells.