Project description:Hairy cell leukemia (HCL) shows unique clinico-pathological and biological features. HCL responds well to purine analogues but relapses are frequent and novel therapies are required. BRAF-V600E is the key driver mutation in HCL and distinguishes it from other B-cell lymphomas, including HCL-like leukemias/lymphomas (HCL-variant and splenic marginal zone lymphoma). The kinase-activating BRAF-V600E mutation also represents an ideal therapeutic target in HCL. Here, we investigated the biological and therapeutic importance of the activated BRAF-MEK-ERK pathway in HCL by exposing in vitro primary leukemic cells purified from 26 patients to clinically available BRAF (Vemurafenib; Dabrafenib) or MEK (Trametinib) inhibitors. Results were validated in vivo in samples from Vemurafenib-treated HCL patients within a phase-2 clinical trial. BRAF and MEK inhibitors caused, specifically in HCL (but not HCL-like) cells, marked MEK/ERK dephosphorylation, silencing of the BRAF-MEK-ERK pathway transcriptional output, loss of the HCL-specific gene expression signature, downregulation of the HCL markers CD25, TRAP and cyclin-D1, smoothening of leukemic cells' hairy surface, and, eventually, apoptosis. Apoptosis was partially blunted by co-culture with bone marrow stromal cells antagonizing MEK-ERK dephosphorylation. This protective effect could be counteracted by combined BRAF and MEK inhibition. Our results strongly support and inform the clinical use of BRAF and MEK inhibitors in HCL.
Project description:Peripheral blood samples were obtained at baseline and at follow-up visit from 20 participants in the Health, Aging and Body Composition prospective cohort study. Genome-wide CpG methylation was assayed using the Illumina Infinium Human MethylationEPIC (HM850K) microarray. We explored longitudinal changes in CpG methylation from blood leukocytes, and likelihood of a future cancer diagnosis.
Project description:Hormonal contraception exposes women to different synthetic progesterone receptor (PR) agonists, progestins, and transiently increases breast cancer risk. How progestins affect the breast epithelium is poorly understood because we lack adequate models to study this. We hypothesized that individual progestins differentially affect cell proliferation in the normal breast epithelium and hence breast cancer risk. Using mouse mammary tissue ex vivo, we show that testosterone-related progestins strongly induce the PR target and mediator of PR signaling induced cell proliferation Receptor Activator of NF-κB Ligand (Rankl), previously implicated in breast carcinogenesis, whereas other progestins fail to do so. We developed xenografts of normal human breast epithelial cells (HBECSs) to the milk ducts of immunocompromised female mice and show that they remain hormone-responsive. Using HBECSs from 36 women, we show that testosterone-related progestins, desogestrel, gestodene, and levonorgestrel, induce PSA (KLK3) and promote their proliferation, whereas the anti-androgenic progestins, which have shown anti-androgenic properties in reporter assays, chlormadinone acetate and cyproterone acetate, do not. Pharmacological inhibition of the androgen receptor (AR) inhibits PR agonist and levonorgestrel-induced RANKL expression and both pharmacological and genetic AR inhibition reduce levonorgestrel-driven breast epithelial cell proliferation in vivo. Prolonged exposure to androgenic progestins elicits hyperproliferation with cytologic changes. Thus, different progestins have distinct biological activities in the breast epithelium that should be taken into account for more informed choices in hormonal contraception.
Project description:Hormonal contraception exposes women to different synthetic progesterone receptor (PR) agonists, progestins, and transiently increases breast cancer risk. How progestins affect the breast epithelium is poorly understood because we lack adequate models to study this. We hypothesized that individual progestins differentially affect cell proliferation in the normal breast epithelium and hence breast cancer risk. Using mouse mammary tissue ex vivo, we show that testosterone-related progestins strongly induce the PR target and mediator of PR signaling induced cell proliferation Receptor Activator of NF-κB Ligand (Rankl), previously implicated in breast carcinogenesis, whereas other progestins fail to do so. We developed xenografts of normal human breast epithelial cells (HBECSs) to the milk ducts of immunocompromised female mice and show that they remain hormone-responsive. Using HBECSs from 36 women, we show that testosterone-related progestins, desogestrel, gestodene, and levonorgestrel, induce PSA (KLK3) and promote their proliferation, whereas the anti-androgenic progestins, which have shown anti-androgenic properties in reporter assays, chlormadinone acetate and cyproterone acetate, do not. Pharmacological inhibition of the androgen receptor (AR) inhibits PR agonist and levonorgestrel-induced RANKL expression and both pharmacological and genetic AR inhibition reduce levonorgestrel-driven breast epithelial cell proliferation in vivo. Prolonged exposure to androgenic progestins elicits hyperproliferation with cytologic changes. Thus, different progestins have distinct biological activities in the breast epithelium that should be taken into account for more informed choices in hormonal contraception.
Project description:The host response to COVID-19 pathophysiology over the first days of infection remains largely unclear especially the mechanisms in the blood compartment. We report here on a longitudinal proteomic analysis of acute phase COVID-19 patients, for which we used blood plasma and MRM proteomics with internal standards as well as DIA. We measured samples on admission for 49 patients, of which 21 with additional samples on days 2, 4, 7, and 14 after admission. We also measured 30 externally obtained samples from healthy individuals for comparison at baseline.