131 research outputs found

    MAF amplification licenses ERα through epigenetic remodelling to drive breast cancer metastasis

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    MAF amplification increases the risk of breast cancer (BCa) metastasis through mechanisms that are still poorly understood yet have important clinical implications. Oestrogen-receptor-positive (ER+) BCa requires oestrogen for both growth and metastasis, albeit by ill-known mechanisms. Here we integrate proteomics, transcriptomics, epigenomics, chromatin accessibility and functional assays from human and syngeneic mouse BCa models to show that MAF directly interacts with oestrogen receptor alpha (ERα), thereby promoting a unique chromatin landscape that favours metastatic spread. We identify metastasis-promoting genes that are de novo licensed following oestrogen exposure in a MAF-dependent manner. The histone demethylase KDM1A is key to the epigenomic remodelling that facilitates the expression of the pro-metastatic MAF/oestrogen-driven gene expression program, and loss of KDM1A activity prevents this metastasis. We have thus determined that the molecular basis underlying MAF/oestrogen-mediated metastasis requires genetic, epigenetic and hormone signals from the systemic environment, which influence the ability of BCa cells to metastasize

    Study of the psi(2)(3823) and chi(c1)(3872) states in B+->(J/psi pi(+)pi(-))K(+)decays

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    The decays B+→J/ψπ+π−K+B^+\rightarrow J/\psi \pi^+ \pi^- K^+ are studied using a data set corresponding to an integrated luminosity of 9fb−1^{-1} collected with the LHCb detector in proton-proton collisions between 2011 and 2018. Precise measurements of the ratios of branching fractions with the intermediate ψ2(3823)\psi_2(3823), χc1(3872)\chi_{c1}(3872) and ψ(2S)\psi(2S) states are reported. The decay of B+→ψ2(3872)K+B^+\rightarrow \psi_2(3872)K^+ with ψ2(3823)→Jψπ+π−\psi_2(3823)\rightarrow J\psi\pi^+\pi^- is observed for the first time with a significance of 5.1 standard deviations. The mass differences between the ψ2(3823)\psi_2(3823), χc1(3872)\chi_{c1}(3872) and ψ(2S)\psi(2S) states are measured to be mχc1(3872)−mψ2(3823)=47.50±0.53±0.13 MeV/c2 ,mψ2(3823)−mψ(2S)=137.98±0.53±0.14 MeV/c2 ,mχc1(3872)−mψ(2S)=185.49±0.06±0.03 MeV/c2 , \begin{array}{rcl} m_{\chi_{c1(3872)}} - m_{\psi_2(3823)} &= & 47.50 \pm 0.53 \pm 0.13\,\mathrm{MeV/}c^2\,, \\ m_{\psi_2(3823)} - m_{\psi(2S)} &= & 137.98 \pm 0.53 \pm 0.14\,\mathrm{MeV/}c^2\,, \\ m_{\chi_{c1}(3872)} - m_{\psi(2S)} &= & 185.49 \pm 0.06 \pm 0.03\,\mathrm{MeV/}c^2\,, \end{array} resulting in the most precise determination of the χc1(3782)\chi_{c1}(3782) mass. The width of the ψ2(3823)\psi_2(3823) state is found to be below 5.2MeV at 90\% confidence level. The Breit-Wigner width of the χc1(3872)\chi_{c1}(3872) state is measured to be Γχc1(3872)BW=0.96−0.18+0.19±0.21MeV, \Gamma^{\mathrm{BW}}_{\chi_{c1}(3872)} = 0.96^{+0.19}_{-0.18}\pm0.21 \mathrm{MeV}, which is inconsistent with zero by 5.5 standard deviations.Comment: 26 pages, 3 figures. All figures and tables, along with any supplementary material and additional information, are available at https://cern.ch/lhcbproject/Publications/p/LHCb-PAPER-2020-009.html (LHCb public pages

    Search for the doubly heavy Xi bc0 baryon via decays to D(0)pK(-)

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    A search for the doubly heavy Ξbc0\mathit{\Xi}_{bc}^{0} baryon using its decay to the D0pK−D^0pK^- final state is performed using proton-proton collision data at a centre-of-mass energy of 13 TeV collected by the LHCb experiment between 2016 and 2018, corresponding to an integrated luminosity of 5.4 fb−1\mathrm{fb}^{-1}. No significant signal is found in the invariant mass range from 6.7 to 7.2 GeV/c2\mathrm{GeV}/c^2. Upper limits are set at 95%95\% credibility level on the ratio of the Ξbc0\mathit{\Xi}_{bc}^{0} production cross-section times its branching fraction to D0pK−D^0pK^- relative to that of the Λb0→D0pK−\mathit{\Lambda}_{b}^{0} \to D^0pK^- decay. The limits are set as a function of the Ξbc0\mathit{\Xi}_{bc}^{0} mass and lifetime hypotheses, in the rapidity range from 2.0 to 4.5 and in the transverse momentum region from 5 to 25 GeV/c\mathrm{GeV}/c. Upper limits range from 1.7×10−21.7\times10^{-2} to 3.0×10−13.0\times10^{-1} for the considered Ξbc0\mathit{\Xi}_{bc}^{0} mass and lifetime hypotheses

    First observation of the decay Lambda(0)(b) -> eta(c) (1S)pK(-)

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    The decay Λb0→ηc(1S)pK−\Lambda_b^0 \to \eta_c(1S) p K^- is observed for the first time using a data sample of proton-proton collisions, corresponding to an integrated luminosity of 5.5 fb−1fb^{-1}, collected with the LHCb experiment at a center-of-mass energy of 13 TeV. The branching fraction of the decay is measured, using the Λb0→J/ψpK−\Lambda_b^0 \to J/\psi p K^- decay as a normalization mode, to be B(Λb0→ηc(1S)pK−)=(1.06±0.16±0.06−0.19+0.22)×10−4\mathcal{B}(\Lambda_b^0 \to \eta_c(1S) p K^-)=(1.06\pm0.16\pm0.06^{+0.22}_{-0.19})\times10^{-4}, where the quoted uncertainties are statistical, systematic and due to external inputs, respectively. A study of the ηc(1S)p\eta_c(1S) p mass spectrum is performed to search for the Pc(4312)+P_c(4312)^+ pentaquark state. No evidence is observed and an upper limit of \begin{equation*} \frac{\mathcal{B}(\Lambda_b^0 \to P_c(4312)^+ K^-)\times \mathcal{B}(P_c(4312)^+ \to \eta_c(1S) p)}{\mathcal{B}(\Lambda_b^0 \to \eta_c(1S) p K^-)} < 0.24 \end{equation*} is obtained at the 95% confidence level.Comment: All figures and tables, along with any supplementary material and additional information, are available at https://cern.ch/lhcbproject/Publications/p/LHCb-PAPER-2020-012.html (LHCb public pages

    Measurement of differential b b ¯ - and c c ¯ -dijet cross-sections in the forward region of pp collisions at s = 13 TeV

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    Abstract: The inclusive bb¯- and cc¯-dijet production cross-sections in the forward region of pp collisions are measured using a data sample collected with the LHCb detector at a centre-of-mass energy of 13 TeV in 2016. The data sample corresponds to an integrated luminosity of 1.6 fb−1. Differential cross-sections are measured as a function of the transverse momentum and of the pseudorapidity of the leading jet, of the rapidity difference between the jets, and of the dijet invariant mass. A fiducial region for the measurement is defined by requiring that the two jets originating from the two b or c quarks are emitted with transverse momentum greater than 20 GeV/c, pseudorapidity in the range 2.2 < η < 4.2, and with a difference in the azimuthal angle between the two jets greater than 1.5. The integrated bb¯-dijet cross-section is measured to be 53.0 ± 9.7 nb, and the total cc¯-dijet cross-section is measured to be 73 ± 16 nb. The ratio between cc¯- and bb¯-dijet cross-sections is also measured and found to be 1.37 ± 0.27. The results are in agreement with theoretical predictions at next-to-leading order

    Strong constraints on the b → sγ photon polarisation from B 0 → K *0 e + e − decays

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    Abstract: An angular analysis of the B0 → K*0e+e− decay is performed using a data sample corresponding to an integrated luminosity of 9 fb−1 of pp collisions collected with the LHCb experiment. The analysis is conducted in the very low dielectron mass squared (q2) interval between 0.0008 and 0.257 GeV2, where the rate is dominated by the B0 → K*0γ transition with a virtual photon. The fraction of longitudinal polarisation of the K*0 meson, FL, is measured to be FL = (4.4 ± 2.6 ± 1.4)%, where the first uncertainty is statistical and the second systematic. The ATRe observable, which is related to the lepton forward-backward asymmetry, is measured to be ATRe = −0.06 ± 0.08 ± 0.02. The AT2 and ATIm transverse asymmetries, which are sensitive to the virtual photon polarisation, are found to be AT2 = 0.11 ± 0.10 ± 0.02 and ATIm = 0.02 ± 0.10 ± 0.01. The results are consistent with Standard Model predictions and provide the world’s best constraint on the b → sγ photon polarisation
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