Publications by authors named "Reyka G Jayasinghe"

Haploidentical hematopoietic cell transplantation (haplo-HCT) is an increasingly used treatment for hematologic malignancies. Although post-transplant cyclophosphamide (PtCy) has improved graft vs. host disease (GvHD) prophylaxis in haplo-HCT, patients continue to experience life-threatening complications.

View Article and Find Full Text PDF

To study the spatial interactions among cancer and non-cancer cells, we here examined a cohort of 131 tumour sections from 78 cases across 6 cancer types by Visium spatial transcriptomics (ST). This was combined with 48 matched single-nucleus RNA sequencing samples and 22 matched co-detection by indexing (CODEX) samples. To describe tumour structures and habitats, we defined 'tumour microregions' as spatially distinct cancer cell clusters separated by stromal components.

View Article and Find Full Text PDF
Article Synopsis
  • Breast cancer (BC) has distinct molecular subtypes influenced by different cell origins, yet the transcriptional networks for these subtypes are not well understood.
  • This study utilized advanced techniques on 61 samples from 37 BC patients to reveal how gene expression and chromatin accessibility connect BC subtypes to their likely cells of origin.
  • Key transcription factors BHLHE40 and KLF5 were found to play crucial roles in luminal and basal-like tumors, respectively, and exhausted CD8 T cells were linked to immune dysfunction in basal-like BC, showcasing the potential of single-cell level analysis in understanding cancer lineages.
View Article and Find Full Text PDF

Invariant natural killer T (iNKT) cells are immune cells that harness properties of both the innate and adaptive immune system and exert multiple functions critical for the control of various diseases. Prevention of graft-versus-host disease (GVHD) by iNKT cells has been demonstrated in mouse models and in correlative human studies in which high iNKT cell content in the donor graft is associated with reduced GVHD in the setting of allogeneic hematopoietic stem cell transplants. This suggests that approaches to increase the number of iNKT cells in the setting of an allogeneic transplant may reduce GVHD.

View Article and Find Full Text PDF

Somatic mutation phasing informs our understanding of cancer-related events, like driver mutations. We generated linked-read whole genome sequencing data for 23 samples across disease stages from 14 multiple myeloma (MM) patients and systematically assigned somatic mutations to haplotypes using linked-reads. Here, we report the reconstructed cancer haplotypes and phase blocks from several MM samples and show how phase block length can be extended by integrating samples from the same individual.

View Article and Find Full Text PDF
Article Synopsis
  • Despite extensive research on genomic changes in glioblastoma, the survival rate remains under 5% after five years.
  • This study aims to broaden the understanding of high-grade glioma by combining various biological analyses (proteomics, metabolomics, etc.) to identify complex regulatory mechanisms involved in tumor growth and progression.
  • Results from analysis of 228 tumors indicate significant variability in early-stage changes, but they converge on common outcomes affecting protein interactions and modifications, highlighting PTPN11's crucial role in high-grade gliomas.
View Article and Find Full Text PDF

Multiple Myeloma (MM) remains incurable despite advances in treatment options. Although tumor subtypes and specific DNA abnormalities are linked to worse prognosis, the impact of immune dysfunction on disease emergence and/or treatment sensitivity remains unclear. We established a harmonized consortium to generate an Immune Atlas of MM aimed at informing disease etiology, risk stratification, and potential therapeutic strategies.

View Article and Find Full Text PDF

Breast cancer is a heterogeneous disease, and treatment is guided by biomarker profiles representing distinct molecular subtypes. Breast cancer arises from the breast ductal epithelium, and experimental data suggests breast cancer subtypes have different cells of origin within that lineage. The precise cells of origin for each subtype and the transcriptional networks that characterize these tumor-normal lineages are not established.

View Article and Find Full Text PDF

Chromatin accessibility is essential in regulating gene expression and cellular identity, and alterations in accessibility have been implicated in driving cancer initiation, progression and metastasis. Although the genetic contributions to oncogenic transitions have been investigated, epigenetic drivers remain less understood. Here we constructed a pan-cancer epigenetic and transcriptomic atlas using single-nucleus chromatin accessibility data (using single-nucleus assay for transposase-accessible chromatin) from 225 samples and matched single-cell or single-nucleus RNA-sequencing expression data from 206 samples.

View Article and Find Full Text PDF

Solid organ transplant represents a potentially lifesaving procedure for patients suffering from end-stage heart, lung, liver, and kidney failure. However, rejection remains a significant source of morbidity and immunosuppressive medications have significant toxicities. Janus kinase (JAK) inhibitors are effective immunosuppressants in autoimmune diseases and graft versus host disease after allogeneic hematopoietic cell transplantation.

View Article and Find Full Text PDF
Article Synopsis
  • DNA methylation is crucial for maintaining cellular identity, but it's often disrupted in tumors and linked with other genetic changes.
  • Researchers analyzed 687 tumors and adjacent normal tissues across various organs to create a Pan-Cancer catalog, highlighting specific methylation patterns.
  • They discovered that certain methylation changes are associated with cancer characteristics, such as hypomethylated FGFR2 in endometrial cancer and hypermethylated STAT5A leading to immune suppression in squamous tumors, revealing the importance of methylation in tumor behavior.
View Article and Find Full Text PDF
Article Synopsis
  • Autologous hematopoietic stem cell transplantation (ASCT) can improve survival rates in multiple myeloma (MM), but some patients struggle to collect enough HSPCs using standard methods like G-CSF.
  • The GENESIS trial tested a new drug, motixafortide, combined with G-CSF, against a placebo and G-CSF to see if it could help mobilize more HSPCs for ASCT.
  • Results showed that motixafortide significantly increased the number of patients who collected sufficient HSPCs, outperforming the placebo group, and its side effects were generally mild and manageable.
View Article and Find Full Text PDF

Identifying tumor-cell-specific markers and elucidating their epigenetic regulation and spatial heterogeneity provides mechanistic insights into cancer etiology. Here, we perform snRNA-seq and snATAC-seq in 34 and 28 human clear cell renal cell carcinoma (ccRCC) specimens, respectively, with matched bulk proteogenomics data. By identifying 20 tumor-specific markers through a multi-omics tiered approach, we reveal an association between higher ceruloplasmin (CP) expression and reduced survival.

View Article and Find Full Text PDF

Unlabelled: As part of the Multiple Myeloma Research Foundation (MMRF) immune atlas pilot project, we compared immune cells of multiple myeloma bone marrow samples from 18 patients assessed by single-cell RNA sequencing (scRNA-seq), mass cytometry (CyTOF), and cellular indexing of transcriptomes and epitopes by sequencing (CITE-seq) to understand the concordance of measurements among single-cell techniques. Cell type abundances are relatively consistent across the three approaches, while variations are observed in T cells, macrophages, and monocytes. Concordance and correlation analysis of cell type marker gene expression across different modalities highlighted the importance of choosing cell type marker genes best suited to particular modalities.

View Article and Find Full Text PDF

Unlabelled: Multiple myeloma (MM) is a highly refractory hematologic cancer. Targeted immunotherapy has shown promise in MM but remains hindered by the challenge of identifying specific yet broadly representative tumor markers. We analyzed 53 bone marrow (BM) aspirates from 41 MM patients using an unbiased, high-throughput pipeline for therapeutic target discovery via single-cell transcriptomic profiling, yielding 38 MM marker genes encoding cell-surface proteins and 15 encoding intracellular proteins.

View Article and Find Full Text PDF

Despite advancements in understanding the pathophysiology of Multiple Myeloma (MM), the cause of rapid progressing disease in a subset of patients is still unclear. MM's progression is facilitated by complex interactions with the surrounding bone marrow (BM) cells, forming a microenvironment that supports tumor growth and drug resistance. Understanding the immune microenvironment is key to identifying factors that promote rapid progression of MM.

View Article and Find Full Text PDF

Pancreatic ductal adenocarcinoma is a lethal disease with limited treatment options and poor survival. We studied 83 spatial samples from 31 patients (11 treatment-naïve and 20 treated) using single-cell/nucleus RNA sequencing, bulk-proteogenomics, spatial transcriptomics and cellular imaging. Subpopulations of tumor cells exhibited signatures of proliferation, KRAS signaling, cell stress and epithelial-to-mesenchymal transition.

View Article and Find Full Text PDF

Motivation: The use of single-cell methods is expanding at an ever-increasing rate. While there are established algorithms that address cell classification, they are limited in terms of cross platform compatibility, reliance on the availability of a reference dataset and classification interpretability. Here, we introduce Pollock, a suite of algorithms for cell type identification that is compatible with popular single-cell methods and analysis platforms, provides a set of pretrained human cancer reference models, and reports interpretability scores that identify the genes that drive cell type classifications.

View Article and Find Full Text PDF

Despite improvement in treatment options for myeloma patients, including targeted immunotherapies, multiple myeloma remains a mostly incurable malignancy. High CS1 (SLAMF7) expression on myeloma cells and limited expression on normal cells makes it a promising target for CAR-T therapy. The CS1 protein has two extracellular domains - the distal Variable (V) domain and the proximal Constant 2 (C2) domain.

View Article and Find Full Text PDF

Late-stage relapse (LSR) in patients with breast cancer (BC) occurs more than five years and up to 10 years after initial treatment and has less than 30% 5-year relative survival rate. Long non-coding RNAs (lncRNAs) play important roles in BC yet have not been studied in LSR BC. Here, we identify 1127 lncRNAs differentially expressed in LSR BC via transcriptome sequencing and analysis of 72 early-stage and 24 LSR BC patient tumors.

View Article and Find Full Text PDF

Development of candidate cancer treatments is a resource-intensive process, with the research community continuing to investigate options beyond static genomic characterization. Toward this goal, we have established the genomic landscapes of 536 patient-derived xenograft (PDX) models across 25 cancer types, together with mutation, copy number, fusion, transcriptomic profiles, and NCI-MATCH arms. Compared with human tumors, PDXs typically have higher purity and fit to investigate dynamic driver events and molecular properties via multiple time points from same case PDXs.

View Article and Find Full Text PDF

Multiple myeloma (MM) is characterized by the uncontrolled proliferation of plasma cells. Despite recent treatment advances, it is still incurable as disease progression is not fully understood. To investigate MM and its immune environment, we apply single cell RNA and linked-read whole genome sequencing to profile 29 longitudinal samples at different disease stages from 14 patients.

View Article and Find Full Text PDF

Non-coding mutations can create splice sites, however the true extent of how such somatic non-coding mutations affect RNA splicing are largely unexplored. Here we use the MiSplice pipeline to analyze 783 cancer cases with WGS data and 9494 cases with WES data, discovering 562 non-coding mutations that lead to splicing alterations. Notably, most of these mutations create new exons.

View Article and Find Full Text PDF