Complete lung agenesis caused by complex genomic rearrangements with neo-TAD formation at the SHH locus

During human organogenesis, lung development is a timely and tightly regulated developmental process under the control of a large number of signaling molecules. Understanding how genetic variants can disturb normal lung development causing different lung malformations is a major goal for dissecting molecular mechanisms during embryogenesis. Here, through exome sequencing (ES), array CGH, genome sequencing (GS) and Hi-C, we aimed at elucidating the molecular basis of bilateral isolated lung agenesis in three fetuses born to a non-consanguineous family. We detected a complex genomic rearrangement containing duplicated, triplicated and deleted fragments involving the SHH locus in fetuses presenting complete agenesis of both lungs and near-complete agenesis of the trachea, diagnosed by ultrasound screening and confirmed at autopsy following termination. The rearrangement did not include SHH itself, but several regulatory elements for lung development, such as MACS1, a major SHH lung enhancer, and the neighboring genes MNX1 and NOM1. The rearrangement incorporated parts of two topologically associating domains (TADs) including their boundaries. Hi-C of cells from one of the affected fetuses showed the formation of two novel TADs each containing SHH enhancers and the MNX1 and NOM1 genes. Hi-C together with GS indicate that the new 3D conformation is likely causative for this condition by an inappropriate activation of MNX1 included in the neo-TADs by MACS1 enhancer, further highlighting the importance of the 3D chromatin conformation in human disease

[Primary non-Hodgkin lymphoma of the uterine corpus. Case report and review of the literature]

International audienceWe report a case of primary nonHodgkin lymphoma (NHL) of the uterine corpus, diagnosed by endometrial biopsy, in a 60-year-old patient suffering from uterine bleeding. Pathological analysis had concluded to diffuse large B-cell lymphoma. Further staging had not revealed other nodal or extranodal localization (Ann Arbor stage IE) and there were no signs of recurrence during follow-up. Therefore, the diagnostic criteria for true primary NHL of the uterine corpus were met. This localization is extremely rare since only six cases have previously been published. The patient was successfully treated by an immunochemotherapy combining rituximab-CHOP and rituximab-VCAP. After 28 months of follow-up, she is free from the disease. A review of the literature regarding these exceptional tumors is undertaken

[Anatomical and histological study of the uterosacral ligament: practical surgical consequences]

International audienceOBJECTIVE: To define the vascular and nervous relationships of the uterosacral ligament and to analyze histologically its content for a better description of this structure. MATERIALS AND METHODS: Three fresh fetal cadavers, three embalmed and one fresh adult cadavers were used. The anatomical relationships of the uterosacral ligament were studied by dissecting one fresh fetal pelvis and two embalmed adult pelves. By histological and immunohistological examinations, eight biopsies of the cervical origin of the complexe ligamentaire utérosacral (USLC) were analyzed: four from fresh fetuses, two from a fresh adult cadaver and two from an embalmed adult cadaver. The specimens were stained with haematoxylin eosin safran (HES) coloration, with antinervous cell specific antibodies (PS100) and with antismooth muscle actine antibodies (to visualize vessel walls) before examination under optical microscope. RESULTS: On anatomic examination, the uterosacral ligament was covered by the visceral pelvic fascia. By removing this fascia, the uterosacral ligament appeared to be a condensation of nervous fibers made up of hypogastric and pelvic nerves forming the hypogastric plexus. Histologically, the uterosacral ligament contained connective tissue, nervous fibers, sympathetic nodes, vessels and fatty tissue. No structured ligamentous organization was identified. CONCLUSION: The uterosacral "ligament" is in fact a "ligament complex" integrating connective tissue as well as nervous and vascular elements. Radical wide excisions of the USLC during cancer or endometriosis surgery and uterosacral suspension during pelvic floor reconstructive surgery should be performed with caution in order to preserve pelvic innervation

Tumor lymphocyte immune response to preoperative radiotherapy in locally advanced rectal cancer: The LYMPHOREC study

IF 7.719International audienceIntroduction: Some studies have suggested that baseline tumor-infiltrating-lymphocytes (TILs), such as CD8+ and FoxP3+ T-cells, may be associated with a better prognosis in colorectal cancer. We sought to investigate modulation of the immune response by preoperative radiotherapy (preopRT) and its impact on survival in locally advanced rectal cancer (LARC). Materials & Methods: We analyzed data for 237 patients with LARC who received RT. Density of TILS (CD8+ and FoxP3+) in intraepithelial (iTILs) and stromal compartments (sTILs) were evaluated from surgery pathological specimens and biopsies performed at baseline. The primary endpoint was to assess the impact of infiltration of the tumor or tumor site after preopRT on progression-free survival (PFS) and overall survival (OS). Secondary endpoints were the impact of dose fractionation scheme on TILs. Results: In univariate analysis, several factors significantly correlated (p<0.05) with PFS and/or OS (T-stage, M-stage, the delay between RT and surgery). A high level of post-treatment FoxP3+ TIL density correlated significantly with a better PFS (p = 0.007). In multivariate analysis, a decrease in the CD8+/FoxP3+ iTILs ratio after preopRT correlated with better PFS and OS (p = 0.049 and p = 0.024, respectively). More particularly, patients with a delta CD8+/FoxP3+ <-3.8 had better PFS and OS. Interestingly, the dose fractionation scheme significantly influenced the CD8+/FoxP3+ ratio after treatment (p = 0.027) with a lower ratio with hypofractionated RT (≥2 Gy). Conclusion: Patients with LARC who had a significant decrease in the CD8+/FoxP3+ ratio after preopRT were more likely to live longer. This ratio needs to be validated prospectively to guide physicians in adjuvant treatment decision-making

Hepatic stem-like phenotype and interplay of Wnt/β\beta-catenin and Myc signaling in aggressive childhood liver cancer

Hepatoblastoma, the most common pediatric liver cancer, is tightly linked to excessive Wnt/beta-catenin signaling. Here, we used microarray analysis to identify two tumor subclasses resembling distinct phases of liver development and a discriminating 16-gene signature. beta-catenin activated different transcriptional programs in the two tumor types, with distinctive expression of hepatic stem/progenitor markers in immature tumors. This highly proliferating subclass was typified by gains of chromosomes 8q and 2p and upregulated Myc signaling. Myc-induced hepatoblastoma-like tumors in mice strikingly resembled the human immature subtype, and Myc downregulation in hepatoblastoma cells impaired tumorigenesis in vivo. Remarkably, the 16-gene signature discriminated invasive and metastatic hepatoblastomas and predicted prognosis with high accuracy

Genotype-first in a cohort of 95 fetuses with multiple congenital abnormalities: when exome sequencing reveals unexpected fetal phenotype-genotype correlations

International audiencePURPOSE: Molecular diagnosis based on singleton exome sequencing (sES) is particularly challenging in fetuses with multiple congenital abnormalities (MCA). Indeed, some studies reveal a diagnostic yield of about 20%, far lower than in live birth individuals showing developmental abnormalities (30%), suggesting that standard analyses, based on the correlation between clinical hallmarks described in postnatal syndromic presentations and genotype, may underestimate the impact of the genetic variants identified in fetal analyses. METHODS: We performed sES in 95 fetuses with MCA. Blind to phenotype, we applied a genotype-first approach consisting of combined analyses based on variants annotation and bioinformatics predictions followed by reverse phenotyping. Initially applied to OMIM-morbid genes, analyses were then extended to all genes. We complemented our approach by using reverse phenotyping, variant segregation analysis, bibliographic search and data sharing in order to establish the clinical significance of the prioritised variants. RESULTS: sES rapidly identified causal variant in 24/95 fetuses (25%), variants of unknown significance in OMIM genes in 8/95 fetuses (8%) and six novel candidate genes in 6/95 fetuses (6%). CONCLUSIONS: This method, based on a genotype-first approach followed by reverse phenotyping, shed light on unexpected fetal phenotype-genotype correlations, emphasising the relevance of prenatal studies to reveal extreme clinical presentations associated with well-known Mendelian disorders