SMC motor proteins extrude DNA asymmetrically and can switch directions.

Structural maintenance of chromosomes (SMC) complexes organize the genome via DNA loop extrusion. Although some SMCs were reported to do so symmetrically, reeling DNA from both sides into the extruded DNA loop simultaneously, others perform loop extrusion asymmetrically toward one direction only. The mechanism underlying this variability remains unclear.

Pan-inhibition of super-enhancer-driven oncogenic transcription by next-generation synthetic ecteinascidins yields potent anti-cancer activity.

The plasticity of cancer cells facilitates their ability to adopt heterogeneous differentiation states, posing a significant challenge to therapeutic interventions. Specific gene expression programs, driven in part by super-enhancers (SEs), underlie cancer cell states. Here we successfully inhibit SE-driven transcription in phenotypically distinct metastatic melanoma cells using next-generation synthetic ecteinascidins.

Changes in AXL and/or MITF melanoma subpopulations in patients receiving immunotherapy.

Background: Tumor heterogeneity is a hurdle to effective therapy, as illustrated by the 'mixed responses' frequently seen in immunotherapy-treated patients. Previously, AXL+ tumor cells were identified to be highly resistant to targeted therapy, whereas more differentiated MITF+ tumor cells do respond to RAF and MEK inhibitors.

Patients And Methods: In this study, we analyzed tumor heterogeneity and explored the presence of the previously described AXL+ or MITF+ melanoma subpopulations in metastatic tissues by NanoString gene expression analysis, single-cell RNA sequencing and multiplex immunofluorescence.

All eukaryotic SMC proteins induce a twist of -0.6 at each DNA loop extrusion step.

Eukaryotes carry three types of structural maintenance of chromosome (SMC) protein complexes, condensin, cohesin, and SMC5/6, which are ATP-dependent motor proteins that remodel the genome via DNA loop extrusion (LE). SMCs modulate DNA supercoiling but remains incompletely understood how this is achieved. Using a single-molecule magnetic tweezers assay that directly measures how much twist is induced by individual SMCs in each LE step, we demonstrate that all three SMC complexes induce the same large negative twist (i.