An embryonic stem cell–like gene expression signature in poorly differentiated aggressive human tumors

Cancer cells possess traits reminiscent of those ascribed to normal stem cells. It is unclear, however, whether these phenotypic similarities reflect the activity of common molecular pathways. Here, we analyze the enrichment patterns of gene sets associated with embryonic stem (ES) cell identity in the expression profiles of various human tumor types. We find that histologically poorly differentiated tumors show preferential overexpression of genes normally enriched in ES cells, combined with preferential repression of Polycomb-regulated genes. Moreover, activation targets of Nanog, Oct4, Sox2 and c-Myc are more frequently overexpressed in poorly differentiated tumors than in well-differentiated tumors. In breast cancers, this ES-like signature is associated with high-grade estrogen receptor (ER)-negative tumors, often of the basal-like subtype, and with poor clinical outcome. The ES signature is also present in poorly differentiated glioblastomas and bladder carcinomas. We identify a subset of ES cell-associated transcription regulators that are highly expressed in poorly differentiated tumors. Our results reveal a previously unknown link between genes associated with ES cell identity and the histopathological traits of tumors and support the possibility that these genes contribute to stem cell–like phenotypes shown by many tumors

Invasive mucormycosis in children: an epidemiologic study in European and non-European countries based on two registries

Abstract Background Mucormycosis has emerged as a rare but frequently fatal invasive fungal disease. Current knowledge on paediatric mucormycosis is based on case reports and small series reported over several decades. Contemporary data on a large cohort of patients is lacking. Methods Two large international registries (Zygomyco.net and FungiScope™) were searched for mucormycosis cases in ≤19 year-old patients. Cases enrolled between 2005 and 2014 were extracted, and dual entries in the two databases merged. Epidemiology, clinical characteristics, diagnostic procedures, therapeutic management and final outcome were recorded and analysed with SPSS v.12. Results Sixty-three unique cases (44 proven and 19 probable) were enrolled from 15 countries (54 in European and 9 in non-European countries). Median age was 13 years [Interquartile Range (IQR) 7.7] with a slight predominance (54.1 %) of females. Underlying conditions were haematological malignancies (46 %), other malignancies (6.3 %), haematopoietic stem cell transplantation (15.9 %), solid organ transplantation, trauma/surgery and diabetes mellitus (4.8 % each) and a variety of other diseases (7.9 %); in 9.5%, no underlying medical condition was found. Neutropenia was recorded in 46 % of the patients. The main sites of infection were lungs (19 %), skin and soft tissues (19 %), paranasal sinus/sino-orbital region (15.8 %) and rhino-cerebral region (7.9 %). Disseminated infection was present in 38.1 %. Mucormycosis diagnosis was based on several combinations of methods; culture combined with histology was performed in 31 cases (49.2 %). Fungal isolates included Rhizopus spp. (39.7 %), Lichtheimia spp. (17.5 %), Mucor spp. (12.7 %), Cunninghamella bertholletiae (6.3 %) and unspecified (23.8 %). Treatment comprised amphotericin B (AmB) monotherapy in 31.7 % or AmB in combination with other antifungals in 47.7 % of the cases, while 14.3 % received no antifungals. Surgery alone was performed in 6.3 %, and combined with antifungal therapy in 47.6 %. Crude mortality at last contact of follow-up was 33.3 %. In regression analysis, disseminated disease and prior haematopoietic stem cell transplantation were associated with increased odds of death, whereas the combination of systemic antifungal therapy with surgery was associated with improved survival. Conclusion Paediatric mucormycosis mainly affects children with malignancies, presents as pulmonary, soft tissue, paranasal sinus or disseminated disease and is highly lethal. Outcome is improved when active antifungal therapy and surgery are combined

Increasing incidence of mucormycosis in a large Spanish hospital from 2007 to 2015: Epidemiology and microbiological characterization of the isolates

We studied 19 cases of proven/probable mucormycosis diagnosed from 2007 to 2015 in our hospital and assessed the microbiological characteristics of the isolates. We recorded the incidence of mucormycosis and clinical and microbiological data of infected patients. Isolates were identified to molecular level and tested for their antifungal susceptibility to azoles, amphotericin B, and liposomal amphotericin B according to the CLSI M-38 A2 procedure. The incidence of mucormycosis in cases/100,000 hospital admissions during 2007-2015 increased significantly with respect to that reported in 1988-2006 (3.3 vs. 1.2; P<0.05). Patients mainly had hematological malignancies (52.6%) and/or trauma/surgical wounds (52.6%) and had received antifungal agents before the diagnosis of mucormycosis in 68% of cases. Diagnosis was by isolation (n = 17/19) and/or direct staining (n = 17/18) of Mucorales fungi in clinical samples. Identification was by panfungal PCR in patients with negative results in culture and in direct staining. The microorganisms identified were Lichtheimia spp. (42%), Rhizopus spp. (21%), Cunninghamella bertholletiae (16%), and others (21%). Liposomal amphotericin B was always more active than the other drugs against all the microorganisms except C. bertholletiae. All patients received antifungal treatment with 1 or more antifungal agents, mainly liposomal amphotericin B (17/19). Mortality was 47.4%, although this was significantly lower in the 11 patients in whom debridement was performed (18% vs. 87.5%) (P = 0.015). The incidence of mucormycosis has risen in recent years. The proportion of cases with soft tissue involvement was high, and Lichtheimia was the most frequently involved species. The highest antifungal activity was observed with liposomal amphotericin B