N-alpha-acetylation is one of the most common co-translational protein modifications in humans and is essential for normal cell function. NAA10 encodes for the enzyme NAA10, which is the catalytic subunit in the N-terminal acetyltransferase A (NatA) complex. The auxiliary and regulatory subunits of the NatA complex are NAA15 and Huntington-interacting protein (HYPK), respectively. Through a genotype-first approach with exome sequencing, we identified and phenotypically characterized 30 individuals from 30 unrelated families with 17 different de novo or inherited, dominantly acting missense variants in NAA10 or NAA15. Clinical features of affected individuals include variable levels of intellectual disability, delayed speech and motor milestones and autism spectrum disorder. Additionally, some subjects present with mild craniofacial dysmorphology, congenital cardiac anomalies and seizures. One of the individuals is an 11-year-old boy with a frameshift variant in exon 7 of NAA10, who presents most notably with microphthalmia, which confirms a prior finding with a single family with Lenz microphthalmia syndrome. Biochemical analyses of variants as part of the human NatA complex, as well as enzymatic analyses with and without the HYPK regulatory subunit, help to explain some of the phenotypic differences seen among the different variants.

Beckwith-Wiedemann syndrome (BWS) and isolated hemihyperplasia (IHH) are two well known overgrowth conditions that are associated with cancer predisposition. Multiple surveillance protocols have been proposed to detect the most commonly reported tumor types Wilms tumor and hepatoblastoma. We reviewed the history of our patients who were part of this monitoring protocol. Information from 63 cases was collected retrospectively while another 63 control samples for AFP measurement were obtained prospectively. Twenty-five (40%) patients had an ultrasound abnormality, the most frequent being nephromegaly/size discrepancy. Two patients had well documented cases of tumors/tumor precursor (2/63:3.2%) detected by ultrasound images. Three hundred thirty-six separate AFP values were available with values above 50,000 ng/ml seen in three patients older than 2 months, one with hepatoblastoma and two other with hemangiomas/hemangioendotheliomas. There was no clear difference in the range of AFP values between previously reported controls, our own normal population and affected patients. In conclusion, ultrasound surveillance detected renal and liver pathology including benign and malignant lesions. The known variability of AFP in normal neonates and patients with BWS makes interpretation difficult in early infancy. Very high AFP values did seem to be correlated with risk for identifiable liver lesions. Determination of the natural changes in AFP levels over time will allow more appropriate comparison.

Smith‐Kingsmore syndrome (SKS) OMIM #616638, also known as MINDS syndrome (ORPHA 457485), is a rare autosomal dominant disorder reported so far in 23 patients. SKS is characterized by intellectual disability, macrocephaly/hemi/megalencephaly, and seizures. It is also associated with a pattern of facial dysmorphology and other non‐neurological features. Germline or mosaic mutations of the mTOR gene have been detected in all patients. The mTOR gene is a key regulator of cell growth, cell proliferation, protein synthesis and synaptic plasticity, and the mTOR pathway (PI3K‐AKT‐mTOR) is highly regulated and critical for cell survival and apoptosis. Mutations in different genes in this pathway result in known rare diseases implicated in hemi/megalencephaly with epilepsy, as the tuberous sclerosis complex caused by mutations in TSC1 and TSC2, or the PIK3CA‐related overgrowth spectrum (PROS). We here present 4 new cases of SKS, review all clinical and molecular aspects of this disorder, as well as some characteristics of the patients with only brain mTOR somatic mutations.

BackgroundNitric oxide (NO) has been highlighted as an important agent in cancer-related events. Although the inducible nitric oxide synthase (iNOS) isoform has received most attention, recent studies in the literature indicate that the endothelial isoenzyme (eNOS) can also modulate different tumor processes including resistance, angiogenesis, invasion, and metastasis. However, the role of eNOS in cancer stem cell (CSC) biology and mesenchymal tumors is unknown.ResultsHere, we show that eNOS was significantly upregulated in VilCreERT2Apcfl/+ and VilCreERT2Apcfl/fl mouse intestinal tissue, with intense immunostaining in hyperproliferative crypts. Similarly, the more invasive VilCreERT2Apcfl/+ Ptenfl/+ mouse model showed an overexpression of eNOS in intestinal tumors whereas this isoform was not expressed in normal tissue. However, none of the three models showed iNOS expression. Notably, when 40 human colorectal tumors were classified into different clinically relevant molecular subtypes, high eNOS expression was found in the poor relapse-free and overall survival mesenchymal subtype, whereas iNOS was absent. Furthermore, Apcfl/fl organoids overexpressed eNOS compared with wild-type organoids and NO depletion with the scavenger carboxy-PTIO (c-PTIO) decreased the proliferation and the expression of stem-cell markers, such as Lgr5, Troy, Vav3, and Slc14a1, in these intestinal organoids. Moreover, specific NO depletion also decreased the expression of CSC-related proteins in human colorectal cancer cells such as β-catenin and Bmi1, impairing the CSC phenotype. To rule out the contribution of iNOS in this effect, we established an iNOS-knockdown colorectal cancer cell line. NO-depleted cells showed a decreased capacity to form tumors and c-PTIO treatment in vivo showed an antitumoral effect in a xenograft mouse model.ConclusionOur data support that eNOS upregulation occurs after Apc loss, emerging as an unexpected potential new target in poor-prognosis mesenchymal colorectal tumors, where NO scavenging could represent an interesting therapeutic alternative to targeting the CSC subpopulation.Electronic supplementary materialThe online version of this article (10.1186/s12915-017-0472-5) contains supplementary material, which is available to authorized users.

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Newly emerged proteomic methodologies, particularly data‐independent acquisition (DIA) analysis–related approaches, would improve current gene expression–based classifications of colorectal cancer (CRC). Therefore, this study was aimed to identify protein expression signatures using SWATH‐MS DIA and targeted data extraction, to aid in the classification of molecular subtypes of CRC and advance in the diagnosis and development of new drugs. For this purpose, 40 human CRC samples and 7 samples of healthy tissue were subjected to proteomic and bioinformatic analysis. The proteomic analysis identified three different molecular CRC subtypes: P1, P2 and P3. Significantly, P3 subtype showed high agreement with the mesenchymal/stem‐like subtype defined by gene expression signatures and characterized by poor prognosis and survival. The P3 subtype was characterized by decreased expression of ribosomal proteins, the spliceosome, and histone deacetylase 2, as well as increased expression of osteopontin, SERPINA 1 and SERPINA 3, and proteins involved in wound healing, acute inflammation and complement pathway. This was also confirmed by immunodetection and gene expression analyses. Our results show that these tumours are characterized by altered expression of proteins involved in biological processes associated with immune evasion and metastasis, suggesting new therapeutic options in the treatment of this aggressive type of CRC.

There is a shortage of genetics providers worldwide and access is limited to large academic centers. Telemedicine programs can facilitate access to genetic services to patients living in remote locations. The goal of this study was to improve access to genetic services in the Dominican Republic by creating a partnership model between a pediatrician and geneticist. This approach has been used within the United States but not in the setting of two different countries, healthcare system, and cultures. Patients were referred to the Centro de Obstetricia y Ginecologia program if a syndromic or genetic etiology was suspected by their local provider. Pediatrician first evaluated all patients prior to telemedicine appointment to review family and medical history. All genetic visits were scheduled within 2 weeks of referral in collaboration with telehealth program at Cincinnati Children's Hospital Medical Center. A total of 66 individuals were evaluated during a period of 5 years. Fifty-seven individuals underwent genetic studies, and a molecular diagnosis was made in 39 individuals. Exome sequencing was the most common first line test when differential diagnosis was broad (n = 40). The most common inheritance was autosomal recessive in 15 individuals, followed by 13 individuals with autosomal dominant disorders, 7 individuals X-linked disorders, and 4 individuals with chromosomal abnormalities. This study provides data to support utility of geneticist and pediatrician partnership to provide outreach telemedicine diagnostics and management services for rare diseases in an international setting.

Tumor budding has been found to be of prognostic significance for several cancers, including colorectal cancer (CRC). Additionally, the molecular classification of CRC has led to the identification of different immune microenvironments linked to distinct prognosis and therapeutic response. However, the association between tumor budding and the different molecular subtypes of CRC and distinct immune profiles have not been fully elucidated. This study focused, firstly, on the validation of derived xenograft models (PDXs) for the evaluation of tumor budding and their human counterparts and, secondly, on the association between tumor budding and the immune tumor microenvironment by the analysis of gene expression signatures of immune checkpoints, Toll-like receptors (TLRs), and chemokine families. Clinical CRC samples with different grades of tumor budding and their corresponding PDXs were included in this study. Tumor budding grade was reliably reproduced in early passages of PDXs, and high-grade tumor budding was intimately related with a poor-prognosis CMS4 mesenchymal subtype. In addition, an upregulation of negative regulatory immune checkpoints (PDL1, TIM-3, NOX2, and IDO1), TLRs (TLR1, TLR3, TLR4, and TLR6), and chemokine receptors and ligands (CXCR2, CXCR4, CXCL1, CXCL2, CXCL6, and CXCL9) was detected in high-grade tumor budding in both human samples and their corresponding xenografts. Our data support a close link between high-grade tumor budding in CRC and a distinctive immune-suppressive microenvironment promoting tumor invasion, which may have a determinant role in the poor prognosis of the CMS4 mesenchymal subtype. In addition, our study demonstrates that PDX models may constitute a robust preclinical platform for the development of novel therapies directed against tumor budding in CRC.