IU Indianapolis ScholarWorks :: Browsing by Author "Ashby, Cody"

Browsing by Author "Ashby, Cody"

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Differential RNA splicing as a potentially important driver mechanism in multiple myeloma
(Ferrata Storti Foundation, 2021-03-01) Bauer, Michael A.; Ashby, Cody; Wardell, Christopher; Boyle, Eileen M.; Ortiz, Maria; Flynt, Erin; Thakurta, Anjan; Morgan, Gareth; Walker, Brian A.; Medicine, School of Medicine
Disruption of the normal splicing patterns of RNA is a major factor in the pathogenesis of a number of diseases. Increasingly research has shown the strong influence that splicing patterns can have on cancer progression. Multiple Myeloma is a molecularly heterogeneous disease classified by the presence of key translocations, gene expression profiles and mutations but the splicing patterns in MM remains largely unexplored. We take a multifaceted approach to define the extent and impact of alternative splicing in MM. We look at the spliceosome component, SF3B1, with hotspot mutations (K700E and K666T/Q) shown to result in an increase in alternative splicing in other cancers. We discovered a number of differentially spliced genes in comparison of the SF3B1 mutant and wild type samples that included, MZB1, DYNLL1, TMEM14C and splicing related genes DHX9, CLASRP, and SNRPE. We identified a broader role for abnormal splicing showing clear differences in the extent of novel splice variants in the different translocation groups. We show that a high number of novel splice loci is associated with adverse survival and an ultra-high risk group. The enumeration of patterns of alternative splicing has the potential to refine MM classification and to aid in the risk stratification of patients.
Epigenomic translocation of H3K4me3 broad domains over oncogenes following hijacking of super-enhancers
(CSH Press, 2021-12) Mikulasova, Aneta; Kent, Daniel; Trevisan-Herraz, Marco; Karataraki, Nefeli; Fung, Kent T. M.; Ashby, Cody; Cieslak, Agata; Yaccoby, Shmuel; Rhee, Frits van; Zangari, Maurizio; Thanendrarajan, Sharmilan; Schinke, Carolina; Morgan, Gareth J.; Asnafi, Vahid; Spicuglia, Salvatore; Brackley, Chris A.; Corcoran, Anne E.; Hambleton, Sophie; Walker, Brian A.; Rico, Daniel; Russell, Lisa J.; Medicine, School of Medicine
Chromosomal translocations are important drivers of hematological malignancies whereby proto-oncogenes are activated by juxtaposition with super-enhancers, often called enhancer hijacking. We analysed the epigenomic consequences of rearrangements between the super-enhancers of the immunoglobulin heavy locus (IGH) and proto-oncogene CCND1 that are common in B cell malignancies. By integrating BLUEPRINT epigenomic data with DNA breakpoint detection, we characterised the normal chromatin landscape of the human IGH locus and its dynamics after pathological genomic rearrangement. We detected an H3K4me3 broad domain (BD) within the IGH locus of healthy B cells that was absent in samples with IGH-CCND1 translocations. The appearance of H3K4me3-BD over CCND1 in the latter was associated with overexpression and extensive chromatin accessibility of its gene body. We observed similar cancer-specific H3K4me3-BDs associated with super-enhancer hijacking of other common oncogenes in B cell (MAF, MYC and FGFR3/NSD2) and in T-cell malignancies (LMO2, TLX3 and TAL1). Our analysis suggests that H3K4me3-BDs can be created by super-enhancers and supports the new concept of epigenomic translocation, where the relocation of H3K4me3-BDs from cell identity genes to oncogenes accompanies the translocation of super-enhancers.
The functional epigenetic landscape of aberrant gene expression in molecular subgroups of newly diagnosed multiple myeloma
(BMC, 2020-08-06) Choudhury, Samrat Roy; Ashby, Cody; Tytarenko, Ruslana; Bauer, Michael; Wang, Yan; Deshpande, Shayu; Den, Judith; Schinke, Carolina; Zangari, Maurizio; Thanendrarajan, Sharmilan; Davies, Faith E.; van Rhee, Frits; Morgan, Gareth J.; Walker, Brian A.; Medicine, School of Medicine
Background Multiple Myeloma (MM) is a hematological malignancy with genomic heterogeneity and poor survival outcome. Apart from the central role of genetic lesions, epigenetic anomalies have been identified as drivers in the development of the disease. Methods Alterations in the DNA methylome were mapped in 52 newly diagnosed MM (NDMM) patients of six molecular subgroups and matched with loci-specific chromatin marks to define their impact on gene expression. Differential DNA methylation analysis was performed using DMAP with a ≥10% increase (hypermethylation) or decrease (hypomethylation) in NDMM subgroups, compared to control samples, considered significant for all the subsequent analyses with p<0.05 after adjusting for a false discovery rate. Results We identified differentially methylated regions (DMRs) within the etiological cytogenetic subgroups of myeloma, compared to control plasma cells. Using gene expression data we identified genes that are dysregulated and correlate with DNA methylation levels, indicating a role for DNA methylation in their transcriptional control. We demonstrated that 70% of DMRs in the MM epigenome were hypomethylated and overlapped with repressive H3K27me3. In contrast, differentially expressed genes containing hypermethylated DMRs within the gene body or hypomethylated DMRs at the promoters overlapped with H3K4me1, H3K4me3, or H3K36me3 marks. Additionally, enrichment of BRD4 or MED1 at the H3K27ac enriched DMRs functioned as super-enhancers (SE), controlling the overexpression of genes or gene-cassettes. Conclusions Therefore, this study presents the underlying epigenetic regulatory networks of gene expression dysregulation in NDMM patients and identifies potential targets for future therapies.
Myeloma Genome Project Panel is a Comprehensive Targeted Genomics Panel for Molecular Profiling of Patients with Multiple Myeloma
(American Association for Cancer Research, 2022) Sudha, Parvathi; Ahsan, Aarif; Ashby, Cody; Kausar, Tasneem; Khera, Akhil; Kazeroun, Mohammad H.; Hsu, Chih-Chao; Wang, Lin; Fitzsimons, Evelyn; Salminen, Outi; Blaney, Patrick; Czader, Magdalena; Williams, Jonathan; Zaid, Mohammad I. Abu; Ansari-Pour, Naser; Yong, Kwee L.; van Rhee, Frits; Pierceall, William E.; Morgan, Gareth J.; Flynt, Erin; Gooding, Sarah; Abonour, Rafat; Ramasamy, Karthik; Thakurta, Anjan; Walker, Brian A.; Medicine, School of Medicine
Purpose: We designed a comprehensive multiple myeloma targeted sequencing panel to identify common genomic abnormalities in a single assay and validated it against known standards. Experimental design: The panel comprised 228 genes/exons for mutations, 6 regions for translocations, and 56 regions for copy number abnormalities (CNA). Toward panel validation, targeted sequencing was conducted on 233 patient samples and further validated using clinical FISH (translocations), multiplex ligation probe analysis (MLPA; CNAs), whole-genome sequencing (WGS; CNAs, mutations, translocations), or droplet digital PCR (ddPCR) of known standards (mutations). Results: Canonical immunoglobulin heavy chain translocations were detected in 43.2% of patients by sequencing, and aligned with FISH except for 1 patient. CNAs determined by sequencing and MLPA for 22 regions were comparable in 103 samples and concordance between platforms was R2 = 0.969. Variant allele frequency (VAF) for 74 mutations were compared between sequencing and ddPCR with concordance of R2 = 0.9849. Conclusions: In summary, we have developed a targeted sequencing panel that is as robust or superior to FISH and WGS. This molecular panel is cost-effective, comprehensive, clinically actionable, and can be routinely deployed to assist risk stratification at diagnosis or posttreatment to guide sequencing of therapies.
Notch3 signaling between myeloma cells and osteocytes in the tumor niche promotes tumor growth and bone destruction
(Elsevier, 2022) Sabol, Hayley M.; Amorim, Tânia; Ashby, Cody; Halladay, David; Anderson, Judith; Cregor, Meloney; Sweet, Megan; Nookaew, Intawat; Kurihara, Noriyoshi; Roodman, G. David; Bellido, Teresita; Delgado-Calle, Jesus; Medicine, School of Medicine
In multiple myeloma (MM), communication via Notch signaling in the tumor niche stimulates tumor progression and bone destruction. We previously showed that osteocytes activate Notch, increase Notch3 expression, and stimulate proliferation in MM cells. We show here that Notch3 inhibition in MM cells reduced MM proliferation, decreased Rankl expression, and abrogated the ability of MM cells to promote osteoclastogenesis. Further, Notch3 inhibition in MM cells partially prevented the Notch activation and increased proliferation induced by osteocytes, demonstrating that Notch3 mediates MM-osteocyte communication. Consistently, pro-proliferative and pro-osteoclastogenic pathways were upregulated in CD138+ cells from newly diagnosed MM patients with high vs. low NOTCH3 expression. These results show that NOTCH3 signaling in MM cells stimulates proliferation and increases their osteoclastogenic potential. In contrast, Notch2 inhibition did not alter MM cell proliferation or communication with osteocytes. Lastly, mice injected with Notch3 knock-down MM cells had a 50% decrease in tumor burden and a 50% reduction in osteolytic lesions than mice bearing control MM cells. Together, these findings identify Notch3 as a mediator of cell communication among MM cells and between MM cells and osteocytes in the MM tumor niche and warrant future studies to exploit Notch3 as a therapeutic target to treat MM.
Pharmacologic targeting of the p62 ZZ domain enhances both anti-tumor and bone-anabolic effects of bortezomib in multiple myeloma
(Ferrata Storti Foundation, 2024-05-01) Marino, Silvia; Petrusca, Daniela N.; Bishop, Ryan T.; Anderson, Judith L.; Sabol, Hayley M.; Ashby, Cody; Layer, Justin H.; Cesarano, Annamaria; Davé, Utpal P.; Perna, Fabiana; Delgado-Calle, Jesus; Chirgwin, John M.; Roodman, G. David; Medicine, School of Medicine
Multiple myeloma (MM) is a malignancy of plasma cells whose antibody secretion creates proteotoxic stress relieved by the N-end rule pathway, a proteolytic system that degrades N-arginylated proteins in the proteasome. When the proteasome is inhibited, protein cargo is alternatively targeted for autophagic degradation by binding to the ZZ-domain of p62/ sequestosome-1. Here, we demonstrate that XRK3F2, a selective ligand for the ZZ-domain, dramatically improved two major responses to the proteasome inhibitor bortezomib (Btz) by increasing: i) killing of human MM cells by stimulating both Btz-mediated apoptosis and necroptosis, a process regulated by p62; and ii) preservation of bone mass by stimulating osteoblast differentiation and inhibiting osteoclastic bone destruction. Co-administration of Btz and XRK3F2 inhibited both branches of the bimodal N-end rule pathway exhibited synergistic anti-MM effects on MM cell lines and CD138+ cells from MM patients, and prevented stromal-mediated MM cell survival. In mice with established human MM, co-administration of Btz and XRK3F2 decreased tumor burden and prevented the progression of MM-induced osteolytic disease by inducing new bone formation more effectively than either single agent alone. The results suggest that p62-ZZ ligands enhance the anti- MM efficacy of proteasome inhibitors and can reduce MM morbidity and mortality by improving bone health.
Plasma cells expression from smouldering myeloma to myeloma reveals the importance of the PRC2 complex, cell cycle progression, and the divergent evolutionary pathways within the different molecular subgroups
(Springer, 2022-02) Boyle, Eileen M.; Rosenthal, Adam; Ghamlouch, Hussein; Wang, Yan; Farmer, Phillip; Rutherford, Michael; Ashby, Cody; Bauer, Michael; Johnson, Sarah K.; Wardell, Christopher P.; Wang, Yubao; Hoering, Antje; Schinke, Carolina; Thanendrarajan, Sharmilan; Zangari, Maurizio; Barlogie, Bart; Dhodapkar, Madhav V.; Davies, Faith E.; Morgan, Gareth J.; van Rhee, Frits; Walker, Brian A.; Medicine, School of Medicine
Sequencing studies have shed some light on the pathogenesis of progression from smouldering multiple myeloma (SMM) and symptomatic multiple myeloma (MM). Given the scarcity of smouldering samples, little data are available to determine which translational programmes are dysregulated and whether the mechanisms of progression are uniform across the main molecular subgroups. In this work, we investigated 223 SMM and 1348 MM samples from the University of Arkansas for Medical Sciences (UAMS) for which we had gene expression profiling (GEP). Patients were analysed by TC-7 subgroup for gene expression changes between SMM and MM. Among the commonly dysregulated genes in each subgroup, PHF19 and EZH2 highlight the importance of the PRC2.1 complex. We show that subgroup specific differences exist even at the SMM stage of disease with different biological features driving progression within each TC molecular subgroup. These data suggest that MMSET SMM has already transformed, but that the other precursor diseases are distinct clinical entities from their symptomatic counterpart.
Structural variants shape the genomic landscape and clinical outcome of multiple myeloma
(Springer Nature, 2022-05-30) Ashby, Cody; Boyle, Eileen M.; Bauer, Michael A.; Mikulasova, Aneta; Wardell, Christopher P.; Williams, Louis; Siegel, Ariel; Blaney, Patrick; Braunstein, Marc; Kaminetsky, David; Keats, Jonathan; Maura, Francesco; Landgren, Ola; Walker, Brian A.; Davies, Faith E.; Morgan, Gareth J.; Medicine, School of Medicine
Deciphering genomic architecture is key to identifying novel disease drivers and understanding the mechanisms underlying myeloma initiation and progression. In this work, using the CoMMpass dataset, we show that structural variants (SV) occur in a nonrandom fashion throughout the genome with an increased frequency in the t(4;14), RB1, or TP53 mutated cases and reduced frequency in t(11;14) cases. By mapping sites of chromosomal rearrangements to topologically associated domains and identifying significantly upregulated genes by RNAseq we identify both predicted and novel putative driver genes. These data highlight the heterogeneity of transcriptional dysregulation occurring as a consequence of both the canonical and novel structural variants. Further, it shows that the complex rearrangements chromoplexy, chromothripsis and templated insertions are common in MM with each variant having its own distinct frequency and impact on clinical outcome. Chromothripsis is associated with a significant independent negative impact on clinical outcome in newly diagnosed cases consistent with its use alongside other clinical and genetic risk factors to identify prognosis.
The molecular make up of smoldering myeloma highlights the evolutionary pathways leading to multiple myeloma
(Springer Nature, 2021-01-12) Boyle, Eileen M.; Deshpande, Shayu; Tytarenko, Ruslana; Ashby, Cody; Wang, Yan; Bauer, Michael A.; Johnson, Sarah K.; Wardell, Christopher P.; Thanendrarajan, Sharmilan; Zangari, Maurizio; Facon, Thierry; Dumontet, Charles; Barlogie, Bart; Arbini, Arnaldo; Rustad, Even H.; Maura, Francesco; Landgren, Ola; Zhan, Fenghuang; van Rhee, Frits; Schinke, Carolina; Davies, Faith E.; Morgan, Gareth J.; Walker, Brian A.; Medicine, School of Medicine
Smoldering myeloma (SMM) is associated with a high-risk of progression to myeloma (MM). We report the results of a study of 82 patients with both targeted sequencing that included a capture of the immunoglobulin and MYC regions. By comparing these results to newly diagnosed myeloma (MM) we show fewer NRAS and FAM46C mutations together with fewer adverse translocations, del(1p), del(14q), del(16q), and del(17p) in SMM consistent with their role as drivers of the transition to MM. KRAS mutations are associated with a shorter time to progression (HR 3.5 (1.5-8.1), p = 0.001). In an analysis of change in clonal structure over time we studied 53 samples from nine patients at multiple time points. Branching evolutionary patterns, novel mutations, biallelic hits in crucial tumour suppressor genes, and segmental copy number changes are key mechanisms underlying the transition to MM, which can precede progression and be used to guide early intervention strategies.
The spatio-temporal evolution of multiple myeloma from baseline to relapse-refractory states
(Springer, 2022-08-03) Rasche, Leo; Schinke, Carolina; Maura , Francesco; Bauer , Michael A.; Ashby, Cody; Deshpande , Shayu; Poos , Alexandra M.; Zangari , Maurizio; Thanendrarajan, Sharmilan; Davies, Faith E.; Walker, Brian A.; Barlogie, Bart; Landgren, Ola; Morgan, Gareth J.; van Rhee, Frits; Weinhold , Niels; Medicine, School of Medicine
Deciphering Multiple Myeloma evolution in the whole bone marrow is key to inform curative strategies. Here, we perform spatial-longitudinal whole-exome sequencing, including 140 samples collected from 24 Multiple Myeloma patients during up to 14 years. Applying imaging-guided sampling we observe three evolutionary patterns, including relapse driven by a single-cell expansion, competing/co-existing sub-clones, and unique sub-clones at distinct locations. While we do not find the unique relapse sub-clone in the baseline focal lesion(s), we show a close phylogenetic relationship between baseline focal lesions and relapse disease, highlighting focal lesions as hotspots of tumor evolution. In patients with ≥3 focal lesions on positron-emission-tomography at diagnosis, relapse is driven by multiple distinct sub-clones, whereas in other patients, a single-cell expansion is typically seen (p < 0.01). Notably, we observe resistant sub-clones that can be hidden over years, suggesting that a prerequisite for curative therapies would be to overcome not only tumor heterogeneity but also dormancy.

Browsing by Author "Ashby, Cody"

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