Regan, D. P. | Search bioRxiv

bioRxiv2023

Epidermal Eg5 promotes X-ROS dependent paclitaxel neurotoxicity

Taxanes are chemotherapeutic agents that induce microtubule modifications in cancer cells, resulting in cell cycle modifications and tumor remission. Here we show that paclitaxel, a widely used taxane, also induces microtubule modifications in healthy epidermal keratinocytes leading to chemotherapy-induced peripheral neuropathy (CIPN). Paclitaxel activates the cell cycle regulator, Kinesin-5 (Eg5), which promotes microtubule detyrosination and fasciculation (dfMT). Eg5 loss protects neurons from paclitaxel neurotoxicity, whereas keratinocyte-specific overexpression promotes axon degeneration. In vivo imaging and 3D reconstructions of dfMTs and nuclei, combined with mechanotransduction studies further show that dfMTs constrict keratinocyte nuclei, leading to nuclear Nox-dependent reactive oxygen species (X-ROS) formation upstream of MMP-13 and cutaneous sensory axon degeneration. This new insight facilitates our understanding of chemotherapy side effects and highlights the need for targeted therapies.

cell biology↗

bioRxiv2023

Integrated analysis of canine soft tissue sarcomas identifies recurrent mutations in TP53, KMT genes and PDGFB fusions

Canine soft tissue sarcomas (STS) are a heterogenous group of malignant tumors arising from mesenchymal cells of soft tissues. This simplified collective of tumors most commonly arise from subcutaneous tissues, are treated similar clinically, and conventionally exclude other sarcomas with more definitive anatomical, histological, or biological features. Histologically, canine STS sub-types are difficult to discern at the light microscopic level due to their overlapping features. Thus, genomic, and transcriptomic profiling of canine STS may prove valuable in differentiating the diverse sub-types of mesenchymal neoplasms within this group. To this purpose we sought to characterize the transcript expression and genomic mutation profiles of canine STS. To delineate transcriptomic sub-types, hierarchical clustering was used to identify 4 groups with district expression profiles. Using the RNAseq data, we identified three samples carrying driver fusions of platelet derived growth factor B (PDGFB) and collagen genes. Sensitivity to imatinib was evaluated in a canine STS cell line also bearing a PDGFB fusion. Using whole exome sequencing, recurrent driver variants were identified in the cancer genes KMT2D (21% of the samples) and TP53 (21%) along with copy number losses of RB1 and CDKN2A. Gene amplifications and resulting transcript increases were identified in genes on chromosomes 13, 14, and 36. A subset of STS was identified with high T-cell infiltration. This multi-omics approach has defined canine STS sub-types at a molecular level for comparison to their human counterparts, to improve diagnosis, and may provide additional targets for therapy.

cancer biology↗