BCL2A1 is a lineage-specific antiapoptotic melanoma oncogene that confers resistance to BRAF inhibition.

Although targeting oncogenic mutations in the BRAF serine/threonine kinase with small molecule inhibitors can lead to significant clinical responses in melanoma, it fails to eradicate tumors in nearly all patients. Successful therapy will be aided by identification of intrinsic mechanisms that protect tumor cells from death. Here, we used a bioinformatics approach to identify drug-able, "driver" oncogenes restricted to tumor versus normal tissues. Applying this method to 88 short-term melanoma cell cultures, we show that the antiapoptotic BCL2 family member BCL2A1 is recurrently amplified in ∼30% of melanomas and is necessary for melanoma growth. BCL2A1 overexpression also promotes melanomagenesis of BRAF-immortalized melanocytes. We find that high-level expression of BCL2A1 is restricted to melanoma due to direct transcriptional control by the melanoma oncogene MITF. Although BRAF inhibitors lead to cell cycle arrest and modest apoptosis, we find that apoptosis is significantly enhanced by suppression of BCL2A1 in melanomas with BCL2A1 or MITF amplification. Moreover, we find that BCL2A1 expression is associated with poorer clinical responses to BRAF pathway inhibitors in melanoma patients. Cotreatment of melanomas with BRAF inhibitors and obatoclax, an inhibitor of BCL2A1 and other BCL2 family members, overcomes intrinsic resistance to BRAF inhibitors in BCL2A1-amplified cells in vitro and in vivo. These studies identify MITF-BCL2A1 as a lineage-specific oncogenic pathway in melanoma and underscore its role for improved response to BRAF-directed therapy.

Three-Dimensional Congenital Heart Models Created With Free Software and a Desktop Printer: Assessment of Accuracy, Technical Aspects, and Clinical Use.

BACKGROUND: Three-dimensional printing is increasingly recognized as a valuable tool for congenital heart disease (CHD) procedural planning and education. Cost and complexity currently limit the more widespread adoption of this technology. We sought to demonstrate the accuracy of 3D printed CHD models created from contrast-enhanced magnetic resonance imaging (MRI) and computed tomography (CT) scans using free software and an inexpensive desktop fused filament fabrication (FFF) printer. METHODS: Solid segmentations of the intracardiac blood pool were created with the program ITK-SNAP. Using the computer program Meshmixer, the segmentation model was hollowed to create a 0.8 mm shell with the inner surface representing endocardium. Three-dimensional models were created on an FFF printer. Four arteries and a ventricular septal defect (VSD) were 3D printed and measured for accuracy. Five models were used to assess candidacy for biventricular surgical repair and one to guide an interventional catheterization. RESULTS: All six patients underwent intervention planned with the 3D models. The computer model shell walls all achieved specifications within 0.05 mm of the designated 0.8 mm thickness and the original solid blood pool segmentation fit within the hollowed 3D model. The 3D printed arteries and VSD all measured accurately to within 0.5 mm of their source computer model. CONCLUSION: Accurate 3D printed models of complex, pediatric CHD may be created from volumetric MRI and CT studies using free online software and printed on an inexpensive desktop printer.

TIR-domain-containing adapter-inducing interferon-ß (TRIF) forms filamentous structures, whose pro-apoptotic signalling is terminated by autophagy.

The formation of amyloid-like protein structures has recently emerged as a feature in signal transduction, particularly in innate immunity. These structures appear to depend on defined domains for their formation but likely also require dedicated ways to terminate signalling. We, here, define the innate immunity protein/Toll-like receptor adaptor TIR-domain-containing adapter-inducing interferon-ß (TRIF) as a novel platform of fibril formation and probe signal initiation through TRIF as well as its termination in Toll-like receptor 3 (TLR3)-stimulated melanoma cells. A main signalling pathway triggered by TLR3 caused apoptosis, which was controlled by inhibitor of apoptosis proteins and was dependent on RIPK1 and independent of TNF. Using correlative electron/fluorescence microscopy, we visualised fibrillar structures formed through both Toll/interleukin-1 receptor and RIP homotypic interacting motif regions of TRIF. We provide evidence that these fibrillary structures are active signalling platforms whose activity is terminated by autophagy. TRIF-signalling enhanced autophagy, and fibrillary structures were partly contained within autophagosomes. Inhibition of autophagy increased levels of pro-apoptotic TRIF complexes, leading to the accumulation of active caspase-8 and enhanced apoptosis while stimulation of autophagy reduced TRIF-dependent death. We conclude that pro-death signals through TRIF are regulated by autophagy and propose that pro-apoptotic signalling through TRIF/RIPK1/caspase-8 occurs in fibrillary platforms.

Induction of cytoplasmic accumulation of p53: a mechanism for low levels of arsenic exposure to predispose cells for malignant transformation.

Although epidemiologic studies have linked arsenic exposure to the development of human cancer, the mechanisms underlying the tumorigenic role of arsenic remain largely undefined. We report here that treatment of cells with sodium arsenite at the concentrations close to environmental exposure is associated with the up-regulation of Hdm2 and the accumulation of p53 in the cytoplasm. Through the mitogen-activated protein kinase pathway, arsenite stimulates the P2 promoter-mediated expression of Hdm2, which then promotes p53 nuclear export. As a consequence, the p53 response to genotoxic stress is compromised, as evidenced by the impaired p53 activation and apoptosis in response to UV irradiation or 5FU treatment. The ability of arsenite to impede p53 activation is further demonstrated by a significantly blunted p53-dependent tissue response to 5FU treatment when mice were fed with arsenite-containing water. Together, our data suggests that arsenic compounds predispose cells to malignant transformation by up-regulation of Hdm2 and subsequent p53 inactivation.