Dierickx, D. | bioRxiv Science

bioRxiv2022

OpenFIBSEM: an application programming interface for easy FIB/SEM automation

Automation in microscopy is the key to success in long and complex experiments. Most microscopy manufacturers provide Application Programming Interfaces (API) to enable communication between a user-defined program and the hardware. Although APIs effectively allow the development of complex routines involving hardware control, the developers need to build the applications from basic commands. Here we present a Software Development Kit (SDK) for easy control of Focussed Ion Beam Scanning Electron Microscopes (FIB/SEM) microscopes. The SDK, which we named OpenFIBSEM consists of a suite of building blocks for easy control that simplify the development of complex automated workflows.

cell biology↗

bioRxiv2022

Aberrant MYCN expression drives oncogenic hijacking of EZH2 as a transcriptional activator in peripheral T cell lymphoma

Peripheral T cell lymphoma (PTCL) is a heterogeneous group of hematological cancers arising from the malignant transformation of mature T cells. In a cohort of 28 PTCL cases, we identified recurrent overexpression of MYCN, a member of the MYC family of oncogenic transcription factors. Approximately half of all PTCL cases was characterized by a MYC expression signature. Inducible expression of MYCN in lymphoid cells in a mouse model caused T cell lymphoma that recapitulated human PTCL with a MYC expression signature. Integration of mouse and human expression data identified EZH2 as a key downstream target of MYCN. Remarkably, EZH2 was found to be an essential co-factor for the transcriptional activation of the MYCN-driven gene expression program, which was independent of methyltransferase activity, but dependent on phosphorylation by CDK1. MYCN-driven T cell lymphoma was sensitive to EZH2 degradation or CDK1 inhibition, which displayed synergy with FDA-approved HDAC inhibitors. Key points- Transcriptomic analysis of PTCL tumors reveals recurrent MYCN overexpression and the presence of a MYC signature in 50% of PTCL cases - EZH2 is a transcriptional cofactor for the MYCN-driven gene expression program, which confers sensitivity to HDAC inhibition

cancer biology↗