Ultra-sensitive molecular detection of gene fusions from RNA using ASPYRE.

BACKGROUND: RNA is a critical analyte for unambiguous detection of actionable mutations used to guide treatment decisions in oncology. Currently available methods for gene fusion detection include molecular or antibody-based assays, which suffer from either being limited to single-gene targeting, lack of sensitivity, or long turnaround time. The sensitivity and predictive value of next generation sequencing DNA-based assays to detect fusions by sequencing intronic regions is variable, due to the extensive size of introns. The required depth of sequencing and input nucleic acid required can be prohibitive; in addition it is not certain that predicted gene fusions are actually expressed. RESULTS: Herein we describe a method based on pyrophosphorolysis to include detection of gene fusions from RNA, with identical assay steps and conditions to detect somatic mutations in DNA [1], permitting concurrent assessment of DNA and RNA in a single instrument run. CONCLUSION: The limit of detection was under 6 molecules/ 6 µL target volume. The workflow and instrumentation required are akin to PCR assays, and the entire assay from extracted nucleic acid to sample analysis can be completed within a single day.

Src-transformed cells hijack mitosis to extrude from the epithelium.

At the initial stage of carcinogenesis single mutated cells appear within an epithelium. Mammalian in vitro experiments show that potentially cancerous cells undergo live apical extrusion from normal monolayers. However, the mechanism underlying this process in vivo remains poorly understood. Mosaic expression of the oncogene vSrc in a simple epithelium of the early zebrafish embryo results in extrusion of transformed cells. Here we find that during extrusion components of the cytokinetic ring are recruited to adherens junctions of transformed cells, forming a misoriented pseudo-cytokinetic ring. As the ring constricts, it separates the basal from the apical part of the cell releasing both from the epithelium. This process requires cell cycle progression and occurs immediately after vSrc-transformed cell enters mitosis. To achieve extrusion, vSrc coordinates cell cycle progression, junctional integrity, cell survival and apicobasal polarity. Without vSrc, modulating these cellular processes reconstitutes vSrc-like extrusion, confirming their sufficiency for this process.

Prognosis in children with pulmonary arterial hypertension: 10-year single-centre experience.

BACKGROUND: Pulmonary arterial hypertension (PAH) is a rare progressive disease of the pulmonary arterioles with an unfavourable prognosis. AIM: To evaluate survival and prognostic factors in patients with PAH diagnosed and treated at a single centre in the years 2004­2013. METHODS: The study included 55 children (33 girls; 66%, 22 boys; 33%), with an average age 6.2 ± 6.0 years, with idiopathic PAH ­ n = 23 (42%), PAH associated with systemic-to-pulmonary shunts ­ n = 17 (31%), and PAH after corrective cardiac surgery ­ n = 15 (27%). Forty-seven of them (87%) were treated with advanced therapy. RESULTS: During the follow-up with an average time of 5.6 ± 4.7 years 15 (27.3%) children died. The one-, three-, five-, and ten-year survival was, respectively, 83.1%, 77.1%, 70.7%, and 65.2%. The analysis of the survival curves revealed a better prognosis in patients with baseline N-terminal pro-B-type natriuretic peptide (NT-proBNP) level < 605 pg/mL (p = 0.024) and a higher probability of survival of three and five years in children at baseline I/II World Health Organisation functional class (WHO-FC). The higher risk of death was associated with a higher pressure in the right atrium (HR 1.23, p < 0.01) and higher pulmonary resistance (HR 1.1, p < 0.01), whereas no history of syncope had a better prognosis (HR 0.31, p = 0.03). CONCLUSIONS: Survival in the study group was comparable to the currently published register data. Mortality risk factors were connected with the severity of the disease at diagnosis.

PKA-regulated VASP phosphorylation promotes extrusion of transformed cells from the epithelium.

At the early stages of carcinogenesis, transformation occurs in single cells within tissues. In an epithelial monolayer, such mutated cells are recognized by their normal neighbors and are often apically extruded. The apical extrusion requires cytoskeletal reorganization and changes in cell shape, but the molecular switches involved in the regulation of these processes are poorly understood. Here, using stable isotope labeling by amino acids in cell culture (SILAC)-based quantitative mass spectrometry, we have identified proteins that are modulated in transformed cells upon their interaction with normal cells. Phosphorylation of VASP at serine 239 is specifically upregulated in Ras(V12)-transformed cells when they are surrounded by normal cells. VASP phosphorylation is required for the cell shape changes and apical extrusion of Ras-transformed cells. Furthermore, PKA is activated in Ras-transformed cells that are surrounded by normal cells, leading to VASP phosphorylation. These results indicate that the PKA-VASP pathway is a crucial regulator of tumor cell extrusion from the epithelium, and they shed light on the events occurring at the early stage of carcinogenesis.