5-Flurouracil disrupts nuclear export and nuclear pore permeability in a calcium dependent manner.

Regulation of nuclear transport is an essential component of apoptosis. As chemotherapy induced cell death progresses, nuclear transport and the nuclear pore complex (NPC) are slowly disrupted and dismantled. 5-Fluorouracil (5-FU) and the camptothecin derivatives irinotecan and topotecan, are linked to altered nuclear transport of specific proteins; however, their general effects on the NPC and transport during apoptosis have not been characterized. We demonstrate that 5-FU, but not topotecan, increases NPC permeability, and disrupts Ran-mediated nuclear transport before the disruption of the NPC. This increased permeability is dependent on increased cellular calcium, as the Ca2+ chelator BAPTA-AM, abolishes the effect. Furthermore, increased calcium alone was sufficient to disrupt the Ran gradient. Combination treatments of 5-FU with topotecan or irinotecan, similarly disrupted nuclear transport before disassembly of the NPC. In both single and combination treatments nuclear transport was disrupted before caspase 9 activation, indicating that 5-FU induces an early caspase-independent increase in NPC permeability and alteration of nuclear transport. Because Crm1-mediated nuclear export of tumor suppressors is linked to drug resistance we also examined the effect of 5-FU on the nuclear export of a specific target, topoisomerase. 5-FU treatment led to accumulation of topoisomerase in the nucleus and recovered the loss nuclear topoisomerase induced by irinotecan or topotecan, a known cause of drug resistance. Furthermore, 5-FU retains its ability to cause nuclear accumulation of p53 in the presence of irinotecan or topotecan. Our results reveal a new mechanism of action for these therapeutics during apoptosis, opening the door to other potential combination chemotherapies that employ 5-FU as a calcium mediated inhibitor of Crm1-induced nuclear export of tumor suppressors.

MusMorph, a database of standardized mouse morphology data for morphometric meta-analyses.

Complex morphological traits are the product of many genes with transient or lasting developmental effects that interact in anatomical context. Mouse models are a key resource for disentangling such effects, because they offer myriad tools for manipulating the genome in a controlled environment. Unfortunately, phenotypic data are often obtained using laboratory-specific protocols, resulting in self-contained datasets that are difficult to relate to one another for larger scale analyses. To enable meta-analyses of morphological variation, particularly in the craniofacial complex and brain, we created MusMorph, a database of standardized mouse morphology data spanning numerous genotypes and developmental stages, including E10.5, E11.5, E14.5, E15.5, E18.5, and adulthood. To standardize data collection, we implemented an atlas-based phenotyping pipeline that combines techniques from image registration, deep learning, and morphometrics. Alongside stage-specific atlases, we provide aligned micro-computed tomography images, dense anatomical landmarks, and segmentations (if available) for each specimen (N = 10,056). Our workflow is open-source to encourage transparency and reproducible data collection. The MusMorph data and scripts are available on FaceBase ( www.facebase.org , https://doi.org/10.25550/3-HXMC ) and GitHub ( https://github.com/jaydevine/MusMorph ).