Guner, G. | bioRxiv Science

bioRxiv2021

PHENOTYPIC CHARACTERIZATION OF TWO NOVEL CELL LINE MODELS OF CASTRATION RESISTANT PROSTATE CANCER.

BACKGROUNDResistance to androgen deprivation therapies is a major driver of mortality in advanced prostate cancer. Therefore, there is a need to develop new pre-clinical models that allow the investigation of resistance mechanisms and the assessment of drugs for the treatment of castration resistant prostate cancer. METHODSWe generated two novel cell line models (LAPC4-CR and VCaP-CR) which were derived by passaging LAPC4 and VCaP cells in vivo and in vitro under castrate conditions. We performed detailed transcriptomic (RNA-seq) and proteomic analyses (SWATH-MS) to delineate expression differences between castration-sensitive and castration-resistant cell lines. Furthermore, we characterized the in vivo and in vitro growth characteristics of the novel cell line models. RESULTSThe two cell line derivatives LAPC4-CR and VCaP-CR showed castration resistant growth in vitro and in vivo which was only minimally inhibited by AR antagonists, enzalutamide and bicalutamide. High-dose androgen treatment resulted in significant growth arrest of VCaP-CR but not in LAPC4-CR cells. Both cell lines maintained AR expression, but exhibited distinct expression changes on the mRNA and protein level. Integrated analyses including data from LNCaP and the previously described castration resistant LNCaP-abl cells revealed an expression signature of castration resistance. CONCLUSIONSThe two novel cell line models LAPC4-CR and VCaP-CR and their comprehensive characterization on the RNA and protein level represent important resources to study the molecular mechanisms of castration resistance.

cancer biology↗

bioRxiv2020

Roles of developmentally regulated KIF2A alternative isoforms in cortical neuron migration and differentiation

KIF2A is a microtubule-depolymerizing kinesin motor protein with essential roles in neural progenitor division and axonal pruning during brain development. KIF2A is alternatively spliced in nervous tissue by specific RNA-binding proteins. However, how different KIF2A isoforms function during development of the cerebral cortex is not known. Here, we focus on three Kif2a isoforms expressed in mouse embryonic and postnatal cerebral cortex. We show that KIF2A is essential for dendritic pruning of primary cortical neurons in mice and that the functions of all three isoforms are sufficient for this process. Interestingly, only two of the isoforms can sustain radial migration of cortical neurons while a third isoform, lacking a key stretch of twenty amino acids, is ineffective. By proximity-labeling-based interactome mapping for individual KIF2A isoforms, we provide novel insight into how isoform specific interactions can confer changes to KIF2A protein function. Our interactome mapping identifies previously known KIF2A interactors, proteins localized to the mitotic spindle poles, and unexpectedly, also translation factors, ribonucleoproteins and proteins that are targeted to the mitochondria and ER, suggesting a novel transport function for KIF2A.

developmental biology↗