Project description:Cutaneous melanoma is characterized by lineage-specific lysosome-associated vesicular trafficking. Specifically, we report a melanoma enrichened lysophagy receptor, CCDC50, controlling lysosomal homeostasis and autolysosomal activity. We reveal that targeting CCDC50 in melanoma may be a promising therapeutic strategy, as nearly 70% of human melanomas highly express CCDC50. Moreover, targeting CCDC50 together with BRAFV600E inhibition induces synergistic function in regression of melanoma tumors, representing an alternative strategy for melanoma therapy. We performed transcriptome profiling (RNA-seq) and quantitative reverse transcription polymerase chain reaction (qRT–PCR) in shCtrl and shCCDC50 cells to evaluate the melanoma growth and metastasis controlled by CCDC50. The deep sequencing results showed that CCDC50 defciency caused increased lysosome and vacuolar memebrane and blocked autophagy flux.
Project description:Huntington’s disease (HD) is a devastating neurological disorder that is caused by an expansion of the poly-Q tract in exon 1 of the Huntingtin gene (HTT). HTT is an evolutionarily conserved and ubiquitously expressed protein that has been linked to a variety of functions including transcriptional regulation, mitochondrial function, and vesicle transport. This large protein has numerous caspase and calpain cleavage sites and can be decorated with several post-translational modifications such as phosphorylations, acetylations, sumoylations, and palmitoylations. However, the exact function of HTT and the role played by its modifications in the cell is still not well understood. Scrutiny of HTT function has been focused on a single, full length, mRNA. In this study, we report the discovery of 5 novel HTT mRNA splice isoforms that are expressed in normal and HD-hESC lines as well as cortical neurons differentiated from hESCs. Interestingly, none of the novel isoforms generates a truncated protein. Instead, 4 of the 5 new isoforms specifically eliminate domains and modifications to generate smaller HTT proteins. The fifth novel isoform incorporates a previously unreported additional exon, dubbed 41b, which is hominid-specific and introduces a potential phosphorylation site in the protein. The discovery of this hominid-specific isoform may shed light on human-specific pathogenic mechanisms of HTT, which could not be investigated with current mouse models of the disease. Furthermore, it provides a new human-specific target for drug screening in Huntington’s disease. We performed RNAseq of human embryonic stem cells in pluripotency conditions to check expression of multiple HTT isoforms.
Project description:Huntington’s disease (HD) is a devastating neurological disorder that is caused by an expansion of the poly-Q tract in exon 1 of the Huntingtin gene (HTT). HTT is an evolutionarily conserved and ubiquitously expressed protein that has been linked to a variety of functions including transcriptional regulation, mitochondrial function, and vesicle transport. This large protein has numerous caspase and calpain cleavage sites and can be decorated with several post-translational modifications such as phosphorylations, acetylations, sumoylations, and palmitoylations. However, the exact function of HTT and the role played by its modifications in the cell is still not well understood. Scrutiny of HTT function has been focused on a single, full length, mRNA. In this study, we report the discovery of 5 novel HTT mRNA splice isoforms that are expressed in normal and HD-hESC lines as well as cortical neurons differentiated from hESCs. Interestingly, none of the novel isoforms generates a truncated protein. Instead, 4 of the 5 new isoforms specifically eliminate domains and modifications to generate smaller HTT proteins. The fifth novel isoform incorporates a previously unreported additional exon, dubbed 41b, which is hominid-specific and introduces a potential phosphorylation site in the protein. The discovery of this hominid-specific isoform may shed light on human-specific pathogenic mechanisms of HTT, which could not be investigated with current mouse models of the disease. Furthermore, it provides a new human-specific target for drug screening in Huntington’s disease.
Project description:Aberrant splice variants are involved in the initiation and/or progression of glial brain tumors. We therefore set out to identify splice variants that are differentially expressed between histological subgroups of gliomas. Splice variants were identified using a novel platform that profiles the expression of virtually all known and predicted exons present in the human genome. Exon-level expression profiling was performed on 26 glioblastomas, 22 oligodendrogliomas and 6 control brain samples. Our results demonstrate that Human Exon arrays can identify subgroups of gliomas based on their histological appearance and genetic aberrations. We next used our expression data to identify differentially expressed splice variants. In two independent approaches, we identified 49 and up to 459 exons that are differentially spliced between glioblastomas and oligodendrogliomas a subset of which (47% and 33%) were confirmed by RT-PCR. In addition, exon-level expression profiling also identified >700 novel exons. Expression of ~67% of these candidate novel exons was confirmed by RT-PCR. Our results indicate that exon-level expression profiling can be used to molecularly classify brain tumor subgroups, can identify differentially regulated splice variants and can identify novel exons. The splice variants identified by exon-level expression profiling may help to detect the genetic changes that cause or maintain gliomas and may serve as novel treatment targets. Keywords: cell type comparison