Genome-wide CRISPR/Cas9 library screening identified ATM signaling network genes as critical drivers for resistance to ATR inhibition in soft-tissue sarcomas: synthetic lethality and therapeutic implications.

Soft-tissue sarcoma (STS) are a heterogeneous group of rare tumors with different biological behavior that are fatal in more than 40% of cases, due to their metastatic evolution and inadequate treatment options. ATR inhibition already showed an activity, even if modest, in broad pre-clinical models of STS. By using genome-wide CRISPR/Cas9 library screening, we identified ATM signaling network genes as critical drivers for resistance to the specific ATR inhibitor AZD6738. The role of such genes in resistance to AZD6738 was confirmed by using CRISPR/Cas9 knockout models. More strikingly, the ATM inhibitor AZD0156 works synergistically with AZD6738 in vitro and abolishes STS growth in vivo in our models of most frequent histotypes (such as dedifferentiated liposarcoma, leiomyosarcoma, and undifferentiated pleomorphic sarcoma among others). Moreover, the combination of AZD6738 and AZD0156 induced significantly higher levels of DNA damage than either drug used as single agent alone. In summary, our results demonstrate that targeting ATM is an effective approach to overcome resistance to ATR inhibition in different STS subtypes, including the most frequent histologies.

[Identification of sentinel lymph node: Comparison between SNOLL and routine isotopic procedure]. / Identification isotopique du ganglion sentinelle : comparaison du SNOLL avec la technique isotopique de référence.

INTRODUCTION: Axillary staging remains the most accurate predictive factor for recurrence risk and survival in patients with invasive breast carcinoma. Sentinel Node Occult Lesion Localization (SNOLL) allows with a single intra-lesion injection both localization of impalpable breast lesion and sentinel node biopsy. Our aim was to compare the efficacy of SNOLL and standard radio isotopic method for sentinel node localization by lymphoscintigraphy. METHODS: This retrospective study enrolled 100 patients treated for breast carcinoma with indication of sentinel node biopsy between may 2017 and January 2019 in breast surgery unit of Montpellier university hospital. RESULTS: SNOLL and standard radio isotopic method were realized in respectively 65 and 35 patients. Failure rates of sentinel node localization were respectively 34% and 11% by lymphoscintigraphy (P=0.02), 17% and 9% intraoperatively and 11% et 6% using radioisotope combined with colorimetric method. DISCUSSION: Failure rate of sentinel node localization is higher using SNOLL. This rate is reduced by additional radioisope migration in the time between isotope injection and surgery and by the use of combined method. SNOLL should therefore be combined with colorimetric method. These results must be confirmed in a larger study.

CHK1 inhibition in soft-tissue sarcomas: biological and clinical implications.

Background: Inhibition of ChK1 appears as a promising strategy for selectively potentiate the efficacy of chemotherapeutic agents in G1 checkpoint-defective tumor cells such as those that lack functional p53 protein. The p53 pathway is commonly dysregulated in soft-tissue sarcomas (STS) through mutations affecting TP53 or MDM2 amplification. GDC-0575 is a selective ATP-competitive inhibitor of CHK1. Methods: We have performed a systematic screening of a panel of 10 STS cell lines by combining the treatment of GDC-0575 with chemotherapy. Cell proliferation, cell death and cell cycle analysis were evaluated with high throughput assay. In vivo experiments were carried out by using TP53-mutated and TP53 wild-type patient-derived xenograft models of STS. Clinical activity of GDC-0575 combined with chemotherapy in patients with TP53-mutated and TP53 wild-type STS was also assessed. Results: We found that GDC-0575 abrogated DNA damage-induced S and G2-M checkpoints, exacerbated DNA double-strand breaks and induced apoptosis in STS cells. Moreover, we observed a synergistic or additive effect of GDC-0575 together with gemcitabine in vitro and in vivo in TP53-proficient but not TP53-deficient sarcoma models. In a phase I study of GDC-0575 in combination with gemcitabine, two patients with metastatic TP53-mutated STS had an exceptional, long-lasting response despite administration of a very low dose of gemcitabine whereas one patient with wild-type TP53 STS had no clinical benefit. Genetic profiling of samples from a patient displaying secondary resistance after 1 year showed loss of one preexisting loss-of-function mutation in the helical domain of DNA2. Conclusion: We provide the first preclinical and clinical evidence that potentiation of chemotherapy activity with a CHK1 inhibitor is a promising strategy in TP53-deficient STS and deserves further investigation in the phase II setting.

Diagnosing pelvic osteomyelitis beneath pressure ulcers in spinal cord injured patients: a prospective study.

There is no consensus on a diagnostic strategy for osteomyelitis underlying pressure ulcers. We conducted a prospective study to assess the accuracy of multiple bone biopsies and imaging to diagnose pelvic osteomyelitis. Patients with clinically suspected osteomyelitis beneath pelvic pressure ulcers were enrolled. Bone magnetic resonance imaging (MRI) and surgical bone biopsies (three or more for microbiology and one for histology per ulcer) were performed. Bacterial osteomyelitis diagnosis relied upon the association of positive histology and microbiology (at least one positive culture for non-commensal microorganisms or three or more for commensal microorganisms of the skin). From 2011 to 2014, 34 patients with 44 pressure ulcers were included. Bacterial osteomyelitis was diagnosed for 28 (82.3%) patients and 35 (79.5%) ulcers according to the composite criterion. Discrepancy was observed between histology and microbiology for 5 (11.4%) ulcers. Most common isolates were Staphylococcus aureus (77.1%), Peptostreptococcus (48.6%) and Bacteroides (40%), cultured in three or more samples in 42.9% of ulcers for S. aureus and ≥20% for anaerobes. Only 2.8% of ulcers had three or more positive specimens with coagulase-negative staphylococci, group B Streptococcus, and nil with enterococci and Pseudomonas aeruginosa. Staphylococcus aureus, Proteus and group milleri Streptococcus were recovered from one sample in 22.8%, 11.4% and 11.4% of ulcers, respectively. Agreement was poor between biopsies and MRI (κ 0.2). Sensitivity of MRI was 94.3% and specificity was 22.2%. The diagnosis of pelvic osteomyelitis relies on multiple surgical bone biopsies with microbiological and histological analyses. At least three bone samples allows the detection of pathogens and exclusion of contaminants. MRI is not routinely useful for diagnosis.

Radioguided occult lesion localization plus sentinel node biopsy (SNOLL) versus wire-guided localization plus sentinel node detection: a case control study of 129 unifocal pure invasive non-palpable breast cancers.

AIMS: We compared histological patterns after lumpectomy for non-palpable breast cancers preoperatively localized by radioguided occult lesion localization plus sentinel node localization (SNOLL) versus wire-guided localization. METHODS: To ensure a homogeneously treated cohort and rigorous comparisons, only patients with invasive cancer and measurable opacity by imaging were included. Exclusion criteria were one or more parameters that could interfere with localization and/or the surgical procedure. Forty-three SNOLL were compared with 86 WGL plus sentinel node (SN) localization. Cancer localization effectiveness was based on careful assessment of histological data from only the first resected glandular specimen, as any additional resection specimens were guided by intraoperative histological examination. RESULTS: Reexcisions to ensure free tissue margins were performed during the same procedure in 13.9% of SNOLL versus 31.3% of WGL; p = 0.02. Significantly more women in SNOLL (53.4%) also had free nearest margins of >9 mm after the first procedure compared with WGL (33.7%); p = 0.03. The median centricity ratio after the first procedure was better in SNOLL (2.8, range 1.3-14) than WGL (5, range 1-50); p = 0.008. The median number of SN detected by lymphoscintigraphy was the same in SNOLL and WGL (1, range 0-9, vs. 1, range 0-8). Intraoperative SN detection by blue dye and/or gamma probe was successful for 97.6% of SNOLL versus 93% of WGL. CONCLUSION: In this study, SNOLL was effective and safe, and this procedure significantly improved the rate of negative margins in the first specimen and the rate of reexcision for positive margins compared with WGL.

Colloid transport in nonuniform temperature.

The aim of this paper is to set up a theoretical framework for obtaining the thermodiffusion (or Soret) coefficient of a colloid in a carrier liquid. It is first argued that the expression of the particle-current density in nonuniform temperature cannot be derived from a theoretical formula valid for an isothermal solution. Then the kinetic theory of Brownian motion is used to derive an expression for the current density properly accounting for thermodiffusion. The cases of free and interacting particles are treated, and the thermodiffusion current pertinent to an ideal solution adds up with a current driven by a temperature- and concentration-dependent potential. Accordingly, a general explicit formula for the thermodiffusion coefficient is obtained. Practical use of the framework is illustrated on simple specific models of a colloid in a solvent. Large Soret coefficients of both signs are calculated for realistic values of the physicochemical parameters, in qualitative agreement with published experimental data.

Thermodiffusion in magnetic colloids evidenced and studied by forced Rayleigh scattering experiments.

This paper shows how forced Rayleigh scattering can be used as an experimental tool for studying thermodiffusion (Soret effect). The systems investigated are magnetic colloids of different types. A framework including thermodiffusion and dielectrophoresis is described in which the evolutions of temperature and of colloid concentration are clearly distinguished. The framework is then shown to account for experiments on steady-state concentration gratings coupled with transient temperature ones, and the parameters are determined therefrom. Dielectrophoretic forces are found to be negligible. Studying different types of magnetic colloids with various dilution rates shows that the sign of the Soret effect is controlled by the nature of the particle coating made up of electrostatic charges or of surfactant, and that its mechanism is located at the nanoparticle core-solvent interface.

Direct evidence that leukemic cells present HLA-associated immunogenic peptides derived from the BCR-ABL b3a2 fusion protein.

The BCR-ABL oncogene is central in the pathogenesis of chronic myeloid leukemia (CML). Here, tandem nanospray mass spectrometry was used to demonstrate cell surface HLA-associated expression of the BCR-ABL peptide KQSSKALQR on class I-negative CML cells transfected with HLA-A*0301, and on primary CML cells from HLA-A3-positive patients. These patients mounted a cytotoxic T-lymphocyte response to KQSSKALQR that also killed autologous CML cells, and tetramer staining demonstrated the presence of circulating KQSSKALQR-specific T cells. The findings are the first demonstration that CML cells express HLA-associated leukemia-specific immunogenic peptides and provide a sound basis for immunization studies against BCR-ABL.

[Lithiasis of the tonsil. Questions, answers]. / Les lithiases de l'amygdale. Questions, réponses.

Imaging, clinical and frequency of the tonsil's calculi in function of the size of the calculi: inframillimetric calculi much frequent, not visible by imaging; small calculi from 1 to 7 mm frequent, visible by the imaging and much often asymptomatic; big ones superior of 7 mm rare, becoming exceptional and much often symptomatic above 15 mm.

[Prognostic value after 1 year of post-infarction exercise test with measurement of oxygen consumption]. / Valeur pronostique à un an du test d'effort postinfarctus avec mesure de la consommation d'oxygène.

A symptoms-limited exercise stress test with measurement of myocardial oxygen consumption (VO2) was carried out in 56 patients on the 44th +/- 16 days after infarction and in 48 patients on the 119th +/- 31 days. Analysis of the expired gases was performed by mass spectrography, cycle by cycle. The second test was coupled with an exercise gamma-angiography in 40 cases. The parameters on exercise were analysed in two groups at one year: group 1 asymptomatic and group 2 symptomatic (subgroup 2a with angina but no dyspnoea, subgroup 2b with dyspnoea). At the second test, the peak VO2 was lower in group 2 (19.46 +/- 5.78 ml/mn/kg) than in group 1 (24.2 +/- 6.5 ml/mn/kg) (p less than 0.008) irrespective of the symptom (angina and/or dyspnoea). The oxygen pulse was lower in group 2a with angina at one year (42.4% +/- 14.3%) compared with asymptomatic group 1 patient (58.5 +/- 12.4%) (p = 0.03). The 3 parameters: VO2, blood pressure and ejection fraction on exercise were independent. The lack of physical fitness may partially explain the absence of variation of the peak VO2 at the first test. These preliminary results should be confirmed by a multivariate analysis in a larger patient group.

Histologic study of peritoneal endometriosis in infertile women.

The present study included 118 patients undergoing a laparoscopy for infertility. In 86 patients with laparoscopically diagnosed endometriosis (group I), biopsies were taken from areas of apparent endometriosis (n = 86) and from a visually normal peritoneum (n = 52). Histology reveals the presence of endometriosis in 93% of positive sites and in 13% of negative sites. In 32 patients without endometriosis at laparoscopy (group II), biopsies were taken from normal uterosacral ligaments (n = 32). Endometriosis was observed in 6% of cases. Despite the increased ability to detect pigmented and nonpigmented endometriotic lesion, histological study revealed the presence of endometriosis in normal peritoneum in 13% (group I) and 6% (group II) of cases.