Implication de la voie de signalisation Sonic Hedgehog (Shh) dans 2 syndromes (la trisomie 18 et le syndrome de Smith-Lemli-Opitz (SLO))

La trisomie 18 (T18) et le syndrome de Smith-Lemli-Opitz (SLO) sont 2 syndromes polymalformatifs pour lesquels un déficit en cholestérol est observé. En prénatal, ils s associent à un taux effondré d œstriol non conjugué maternel (uE3), marqueur du dépistage de la trisomie 21, reflétant le taux de cholestérol fœtal. L ajout de cholestérol à Sonic Hedgehog (Shh) lui assure une activité maximale. Certaines malformations surviennent dans des tissus où Shh joue un rôle primordial. L objectif de cette étude rétrospective portant sur des cas de T18 et de SLO fœtaux était de déterminer si le déficit en cholestérol était à l origine de l altération de la voie Shh et de malformations. Le nombre de celles-ci a été corrélé au taux d uE3 maternel. Nous avons dosé le cholestérol dans le milieu de culture d amniocytes de T18, SLO et de témoins par LC/MSMS, puis testé l expression de gènes de la voie Shh par RT-PCR quantitative : les facteurs GLI, et des gènes cibles de Shh : BMP2, BMP4, TGFb1, COL1A1 et COL1A2. L expression protéique de Shh, BMP2 et COL1 a été testée. Enfin, l expression de ces gènes a été évaluée dans des amniocytes témoins traités par inhibiteur de synthèse du cholestérol. L activité de liaison des GLI a été étudiée par gel retard. On observe une corrélation inverse entre la sévérité phénotypique et le taux d uE3 dans le SLO et la T18. Le taux de cholestérol dosé dans le milieu de culture d amniocytes est corrélé au taux d uE3 et significativement plus bas en cas de T18 et de SLO. On rapporte une diminution d expression des gènes testés et une différence d activité de liaison des GLI en cas de T18. Cette perturbation n est pas significative dans les amniocytes traités.Trisomy 18 (T18) and Smith Lemli Opitz (SLO) syndrome are two polymalformative conditions in which cholesterol defect was noticed. Prenatally, they are associated with a decreased maternal unconjugated estriol (uE3) level, one of the second trimester maternal serum screening test that reflects fetal cholesterol level. Addition of cholesterol allows Shh protein maturation. Many malformations in these 2 syndromes occur in Shh dependent tissus. We thus sought to assess whether cholesterol defect could affect Shh pathway and explain malformations. We selected trisomy 18 and SLO cases in which maternal uE3 level was decreased and reported fetal malformations. We correlated the number of malformations with maternal uE3 level. We carried out cholesterol dosage in culture medium of trisomy 18, SLO and control amniocytes through LC/MSMS. We then analyzed Shh pathway in testing gene expression of several Shh components : GLI transcription factors, and Shh targets : BMP2, BMP4, TGFb1, COL1A1 and COL1A2. Protein expression of Shh, BMP2 and COL1 was tested. Gene expression was also tested in control amniocytes treated with an anti-cholesterol. Finally, GLI binding activity was tested using gel retardation assay. We observed an inverse correlation between phenotypic severity and maternal uE3 level in SLO and trisomy 18. Cholesterol level in culture medium of amniocytes is correlated with maternal uE3 level and significantly lower in T18 and SLO amniocytes. There is an alteration in Shh pathway as expression of several genes is decreased in T18 and SLO amniocytes. We also observed a different GLI binding activity in T18 amniocytes. This alteration is not significant in treated amniocytes.CAEN-BU Médecine pharmacie (141182102) / SudocSudocFranceF

Marqueurs chromosomiques surnuméraires sur caryotype foetal (étude d'une série de 20 cas)

CAEN-BU Médecine pharmacie (141182102) / SudocPARIS-BIUM (751062103) / SudocSudocFranceF

Involvement and alteration of the Sonic Hedgehog pathway is associated with decreased cholesterol level in trisomy 18 and SLO amniocytes.

International audienceBACKGROUND: Trisomy 18 and Smith-Lemli-Opitz syndrome are two polymalformative conditions in which a cholesterol defect has been noted. When they occur prenatally, they are associated with a decreased maternal unconjugated estriol (uE(3)) level. Cholesterol plays an essential role in the Sonic Hedgehog pathway, allowing Shh protein maturation leading to its maximal activity. Many malformations in these two syndromes occur in Shh dependent tissues. We thus sought to assess whether a cholesterol defect could affect the Shh pathway and explain some of the observed malformations. MATERIALS AND METHODS: We selected 14 cases of trisomy 18 and 3 cases of SLO in which the maternal uE(3) level was decreased and reported malformations were observed after fetopathological examination. We correlated the number of malformations with maternal uE(3) level. We then carried out cholesterol concentrations in separate culture media consisting of trisomy 18, SLO and control amniocytes. Finally, we analyzed the Shh pathway by testing the gene expression of several Shh components: GLI transcription factors, BMP2, BMP4, TGFβ1, COL1A1 and COL1A2. RESULTS AND DISCUSSION: There was an inverse correlation between phenotypic severity and maternal uE(3) levels in SLO and trisomy 18. The cholesterol levels in the amniocyte culture media were correlated with maternal uE3 levels and were significantly lower in T18 and SLO amniocytes, reflecting cholesterol defects. There was an alteration in the Shh pathway since expression of several genes was decreased in T18 and SLO amniocytes. However, these cholesterol defects were not solely responsible for the altered Shh pathway and the malformations observed

Autologous stem cell transplantation as a first-line treatment strategy for chronic lymphocytic leukemia: a multicenter, randomized, controlled trial from the SFGM-TC and GFLLC.

Long-term responses have been reported after autologous stem cell transplantation (ASCT) for chronic lymphocytic leukemia (CLL). We conducted a prospective, randomized trial of ASCT in previously untreated CLL patients. We enrolled 241 patients < 66 years of age with Binet stage B or C CLL. They received 3 courses of mini-CHOP (cyclophosphamide, hydroxydaunorubicin, oncovin, and prednisone/prednisolone) and then 3 courses of fludarabine. Patients in complete response (CR) were then randomized to ASCT or observation, whereas the other patients were randomized to dexamethasone, high-dose aracytin, cisplatin (DHAP) salvage followed by either ASCT or 3 courses of fludarabine plus cyclophosphamide (FC). The primary end point was event-free survival (EFS). After up-front treatment, 105 patients entered CR and were randomized between ASCT (n = 52) and observation (n = 53); their respective 3-year EFS rates were 79.8% and 35.5%; the adjusted hazard ratio was 0.3 (95% CI: 0.1-0.7; P = .003). Ninety-four patients who did not enter CR were randomized between ASCT (n = 46) and FC (n = 48); their respective 3-year EFS rates were 48.9% and 44.4%, respectively; the adjusted hazard ratio was 1.7 (95% CI: 0.9-3.2; P = .13). No difference in overall survival was found between the 2 response subgroups. In young CLL patients in CR, ASCT consolidation markedly delayed disease progression. No difference was observed between ASCT and FC in patients requiring DHAP salvage

Pregnancy outcomes in prenatally diagnosed 47,XXX and 47,XYY syndromes: a 30-year French, retrospective, multicentre study

International audienceOBJECTIVE: Sex chromosome aneuploidies are frequently detected fortuitously in a prenatal diagnosis. Most cases of 47,XXX and 47,XYY syndromes are diagnosed in this context, and parents are thus faced with an unexpected situation. The objective of the present study was to characterize a French cohort of prenatally diagnosed cases of 47,XXX and 47,XYY and to evaluate the termination of pregnancy (TOP) rate before and after France's implementation of multidisciplinary centres for prenatal diagnosis (MCPDs) in 1997. METHODS: This retrospective study identified respectively 291 and 175 cases of prenatally diagnosed 47,XXX and 47,XYY between 1976 and 2012. For each case, the indication, maternal age, karyotype and outcome were recorded. RESULTS: Most diagnoses of the two conditions were fortuitous. The occurrence of 47,XXX was associated with advanced maternal age. The overall TOP rate was higher for 47,XXX (22.9%) than for 47,XYY (14.6%), although this difference was not statistically significant. However, the TOP rates fell significantly after 1997 (from 41.1% to 11.8% for 47,XXX and from 25.8% to 6.7% for 47,XYY). CONCLUSION: The TOP rates after prenatal diagnoses of 47,XXX and 47,XYY fell significantly after 1997, following France's implementation of MCPD

Distinct deregulation of the hypoxia inducible factor by PHD2 mutants identified in germline DNA of patients with polycythemia

International audienceBACKGROUND: Congenital secondary erythrocytoses are due to deregulation of hypoxia inducible factor resulting in overproduction of erythropoietin. The most common germline mutation identified in the hypoxia signaling pathway is the Arginine 200-Tryptophan mutant of the von Hippel-Lindau tumor suppressor gene, resulting in Chuvash polycythemia. This mutant displays a weak deficiency in hypoxia inducible factor α regulation and does not promote tumorigenesis. Other von Hippel-Lindau mutants with more deleterious effects are responsible for von Hippel-Lindau disease, which is characterized by the development of multiple tumors. Recently, a few mutations in gene for the prolyl hydroxylase domain 2 protein (PHD2) have been reported in cases of congenital erythrocytosis not associated with tumor formation with the exception of one patient with a recurrent extra-adrenal paraganglioma.DESIGN AND METHODS: Five PHD2 variants, four of which were novel, were identified in patients with erythrocytosis. These PHD2 variants were functionally analyzed and compared with the PHD2 mutant previously identified in a patient with polycythemia and paraganglioma. The capacity of PHD2 to regulate the activity, stability and hydroxylation of hypoxia inducible factor α was assessed using hypoxia-inducible reporter gene, one-hybrid and in vitro hydroxylation assays, respectively.RESULTS: This functional comparative study showed that two categories of PHD2 mutants could be distinguished: one category with a weak deficiency in hypoxia inducible factor α regulation and a second one with a deleterious effect; the mutant implicated in tumor occurrence belongs to the second category.CONCLUSIONS: As observed with germline von Hippel-Lindau mutations, there are functional differences between the PHD2 mutants with regards to hypoxia inducible factor regulation. PHD2 mutation carriers do, therefore, need careful medical follow-up, since some mutations must be considered as potential candidates for tumor predisposition

MiR-31-3p do not predict anti-EGFR efficacy in first-line therapy of RAS wild-type metastatic right-sided colon cancer

International audienceBACKGROUND: Low miR-31-3p expression was identified as predictive of anti-EGFR efficacy in RAS-wt mCRC. Primary tumor side was also proposed as a predictive factor of anti-EGFR benefit. This retrospective multicentric study evaluated the predictive role of miR-31-3p in right-sided RAS-wt mCRC patients treated with first-line CT+anti-EGFR or CT+bevacizumab (Beva). METHODS: Seventy-two right-sided RAS-wt mCRC patients treated in first-line with CT+anti-EGFR (n=43) or Beva (n=29) were included. Overall survival (OS), progression-free survival (PFS) and response rate (RR) were analyzed and stratified according to tumor miR-31-3p expression level and targeted therapy (TT). RESULTS: BRAF V600E mutation was more frequent in high vs low miR-31-3p expressers (60.6% vs 15.4%, P &lt; 0.001). PFS was significantly longer with CT+Beva than with CT+anti-EGFR (13 vs 7 months; P = 0.024). Among low miR-31-3p expressers, PFS, OS and RR were not significantly different between the two groups, while in high miR-31-3p expressers, only PFS was longer in the CT+Beva group (11 vs 6 months; P = 0.03). In patients treated with CT+anti-EGFR, low miR-31-3p expressers had a significantly longer OS (20 vs 13 months; P = 0.02) than high miR-31-3p expressers. ORR was not significantly different between the two groups of treatment, in both low and high miR-31-3p expressers. MiR-31-3p expression status was statistically correlated between primary tumors and corresponding metastases. CONCLUSION: In this study, miR-31-3p couldn’t identify a subgroup of patients with right-sided RAS-wt mCRC who might benefit from anti-EGFR and suggest that Beva is the TT of choice in first-line treatment of these patients

Development of an angiogenesis animal model featuring brain arteriovenous malformation histological characteristics

International audienc