Cell Lineage Analysis of the Mammalian Female Germline

Fundamental aspects of embryonic and post-natal development, including maintenance of the mammalian female germline, are largely unknown. Here we employ a retrospective, phylogenetic-based method for reconstructing cell lineage trees utilizing somatic mutations accumulated in microsatellites, to study female germline dynamics in mice. Reconstructed cell lineage trees can be used to estimate lineage relationships between different cell types, as well as cell depth (number of cell divisions since the zygote). We show that, in the reconstructed mouse cell lineage trees, oocytes form clusters that are separate from hematopoietic and mesenchymal stem cells, both in young and old mice, indicating that these populations belong to distinct lineages. Furthermore, while cumulus cells sampled from different ovarian follicles are distinctly clustered on the reconstructed trees, oocytes from the left and right ovaries are not, suggesting a mixing of their progenitor pools. We also observed an increase in oocyte depth with mouse age, which can be explained either by depth-guided selection of oocytes for ovulation or by post-natal renewal. Overall, our study sheds light on substantial novel aspects of female germline preservation and development

Colon Stem Cell and Crypt Dynamics Exposed by Cell Lineage Reconstruction

Stem cell dynamics in vivo are often being studied by lineage tracing methods. Our laboratory has previously developed a retrospective method for reconstructing cell lineage trees from somatic mutations accumulated in microsatellites. This method was applied here to explore different aspects of stem cell dynamics in the mouse colon without the use of stem cell markers. We first demonstrated the reliability of our method for the study of stem cells by confirming previously established facts, and then we addressed open questions. Our findings confirmed that colon crypts are monoclonal and that, throughout adulthood, the process of monoclonal conversion plays a major role in the maintenance of crypts. The absence of immortal strand mechanism in crypts stem cells was validated by the age-dependent accumulation of microsatellite mutations. In addition, we confirmed the positive correlation between physical and lineage proximity of crypts, by showing that the colon is separated into small domains that share a common ancestor. We gained new data demonstrating that colon epithelium is clustered separately from hematopoietic and other cell types, indicating that the colon is constituted of few progenitors and ruling out significant renewal of colonic epithelium from hematopoietic cells during adulthood. Overall, our study demonstrates the reliability of cell lineage reconstruction for the study of stem cell dynamics, and it further addresses open questions in colon stem cells. In addition, this method can be applied to study stem cell dynamics i

Treatment patterns, testing practices, and outcomes in the pre-FLAURA era for patients with EGFR mutation-positive advanced NSCLC: a retrospective chart review (REFLECT)

Introduction: For epidermal growth factor receptor mutation-positive (EGFRm) non-small-cell lung cancer (NSCLC), EGFR-tyrosine kinase inhibitors (EGFR-TKIs) are the preferred first-line (1 L) treatment in the advanced setting. Osimertinib, a third-generation EGFR-TKI, received full approval in 2017 for second-line (2 L) treatment of EGFR T790M-positive NSCLC. The REFLECT study characterizes real-world treatment/testing patterns, attrition rates, and outcomes in patients with EGFRm advanced NSCLC treated with 1 L first-/second-generation (1G/2G) EGFR-TKIs before 1 L osimertinib approval. Methods: Retrospective chart review (NCT04031898) of European/Israeli adults with EGFRm unresectable locally advanced/metastatic NSCLC, initiating 1 L 1G/2G EGFR-TKIs 01/01/15-30/06/18 (index date). Results: In 896 patients (median follow-up of 21.5 months), the most frequently initiated 1 L EGFR-TKI was afatinib (45%). Disease progression was reported in 81%, including 10% (86/896) who died at 1 L. By the end of study, most patients discontinued 1 L (85%), of whom 33% did not receive 2 L therapy. From index, median 1 L real-world progression-free survival was 13.0 (95% confidence interval (CI): 12.3-14.1) months; median overall survival (OS) was 26.2 (95% CI: 23.6-28.4) months. 71% of patients with 1 L progression were tested for T790M; 58% were positive. Of those with T790M, 95% received osimertinib in 2 L or later. Central nervous system (CNS) metastases were recorded in 22% at index, and 15% developed CNS metastases during treatment (median time from index 13.5 months). Median OS was 19.4 months (95% CI: 17.1-22.1) in patients with CNS metastases at index, 24.8 months (95% CIs not available) with CNS metastases diagnosed during treatment, and 30.3 months (95% CI: 27.1, 33.8) with no CNS metastases recorded. Conclusion: REFLECT is a large real-world study describing treatment patterns prior to 1 L osimertinib availability for EGFRm advanced NSCLC. Given the attrition rates highlighted in the study and the impact of CNS progression on outcomes, offering a 1 L EGFR-TKI with CNS penetration may improve patient outcomes in this treatment setting

Treatment patterns, testing practices, and outcomes in the pre-FLAURA era for patients with EGFR mutation-positive advanced NSCLC : a retrospective chart review (REFLECT)

Background. Immunotherapy with immune checkpoint inhibitors (ICIs) recently became the standard treatment for patients with advanced non-small cell lung cancer (NSCLC). Here, we present the first results of a real-world observational study on the effectiveness of ICI monotherapy in patients with advanced NSCLC treated at a single academic center in a Central and Eastern European (CEE) country. Materials and methods. Overall, 66 consecutive patients with advanced NSCLC treated with ICIs in everyday clinical practice, either with first-line pembrolizumab (26 patients) or second-line atezolizumab, nivolumab, or pembrolizumab (40 patients), from August 2015 to November 2018, were included. All data were retrieved from a hospital lung cancer registry, in which the data is collected prospectively. Results. Included patients had a median age of 64 years, most were male (55%), 6% were in performance status >/=2, and 18% had controlled central nervous system metastases at baseline. In first-line, the median progression-free survival (mPFS) was 9.3 months, while the median overall survival (mOS) was not reached. The 1-year overall survival (OS) was 62%. In second-line, the mPFS and mOS were 3.5 months and 9.9 months, respectively, with a 1-year OS of 35%. In the overall population, adverse events of any grade were recorded in 79% of patients and of severe grade (3-4) in 12% of patients. Conclusion. The first real-world outcomes of NSCLC immunotherapy from a CEE country suggest comparable effectiveness to those observed in clinical trials and other real-world series, mainly coming from North America and Western European countries. Further data to inform on the real-world effectiveness of immunotherapy worldwide are needed

Cell competition during reprogramming gives rise to dominant clones

International audienceThe ability to generate induced pluripotent stem cells from differentiated cell types has enabled researchers to engineer cell states. Although studies have identified molecular networks that reprogram cells to pluripotency, the cellular dynamics of these processes remain poorly understood. Here, by combining cellular barcoding, mathematical modeling, and lineage tracing approaches, we demonstrate that reprogramming dynamics in heterogeneous populations are driven by dominant “elite” clones. Clones arise a priori from a population of poised mouse embryonic fibroblasts derived from Wnt1-expressing cells that may represent a neural crest–derived population.This work highlights the importance of cellular dynamics in fate programming outcomes and uncovers cell competition as a mechanism by which cells with eliteness emerge to occupy and dominate the reprogramming niche

Pregnancy in women with hypertrophic cardiomyopathy: data from the European Society of Cardiology initiated Registry of Pregnancy and Cardiac disease (ROPAC)

Aims We report the maternal and foetal outcomes at birth and after 6 months in a cohort of pregnant women with hypertrophic cardiomyopathy (HCM). Although most women with HCM tolerate pregnancy well, there is an increased risk of obstetric and cardiovascular complications. Methods and results All pregnant women with HCM entered into the prospective worldwide Registry of Pregnancy and Cardiac disease (ROPAC) were included in this analysis. The primary endpoint was a major adverse cardiovascular event (MACE), which included death, heart failure (HF), thrombo-embolic event, and arrhythmia. Baseline and outcome data were analysed and compared for patients with MACE vs. without MACE and for patients with obstructive HCM vs. non-obstructive HCM. Sixty pregnant women (mean age 30.4 +/- 6.0 years) with HCM (41.7% obstructive) were included. No maternal mortality occurred in this cohort. In 14 (23%) patients at least one MACE occurred: 9 (15.0%) HF and 7 (12%) an arrhythmia (6 ventricular and 1 atrial fibrillation). MACE occurred most commonly during the 3rd trimester and postpartum period. In total, 3 (5.0%) women experienced foetal loss. Women with MACE had a higher rate of emergency Caesarean delivery for cardiac reasons (21.4% vs. 0%, P = 0.01). No significant differences in pregnancy outcome were found between women with obstructive and non-obstructive HCM. NYHA functional class of >= II and signs of HF before pregnancy, were associated with MACE. Conclusion Although most women with HCM tolerated pregnancy well, cardiovascular complications were not uncommon and predicted by pre-pregnancy status facilitating pre-pregnancy counselling and targeted antenatal care

CD24 tracks divergent pluripotent states in mouse and human cells

Reprogramming is a dynamic process that can result in multiple pluripotent cell types emerging from divergent paths. Cell surface protein expression is a particularly desirable tool to categorize reprogramming and pluripotency as it enables robust quantification and enrichment of live cells. Here we use cell surface proteomics to interrogate mouse cell reprogramming dynamics and discover CD24 as a marker that tracks the emergence of reprogramming-responsive cells, while enabling the analysis and enrichment of transgene-dependent (F-class) and -independent (traditional) induced pluripotent stem cells (iPSCs) at later stages. Furthermore, CD24 can be used to delineate epiblast stem cells (EpiSCs) from embryonic stem cells (ESCs) in mouse pluripotent culture. Importantly, regulated CD24 expression is conserved in human pluripotent stem cells (PSCs), tracking the conversion of human ESCs to more naive-like PSC states. Thus, CD24 is a conserved marker for tracking divergent states in both reprogramming and standard pluripotent culture

Accelerated increase in GV oocyte from large antral follicles depth following unilateral ovariectomy.

<p>a–c) Reconstructed lineage trees of oocytes from both ovaries of unilaterally ovariectomized mice. Blue circles are oocytes extracted from the ovary removed at a young age – 23 days (a) 29 days (b) and 26 days (c). Green circles are oocytes extracted from the contralateral ovary removed at an older age – 139 days (a) 161 days (b) and 150 days in which the ovulated oocytes were marked with blue dots (c). Horizontal lines are the average depths of young oocytes (blue) and old oocytes (green). d) Increase in depth with age following ovariectomy is accelerated relative to the increase observed for non-ovariectomized mice. Last two boxes include pooled data from the indicated mice. * p<0.05, ** p<0.01.</p