Abstract 5174: Utilization of Cell free messenger RNA Sequencing for non-invasive molecular profiling of multiple myeloma and Acute Myeloid Leukemia
Authors: Toden Shusuke , Ross David A. , Quake Stephen R. , Sninsky John J. 
Published: June 2022

Abstract
Background and Aims: Hematologic malignancies account for approximately 10% of all cancers in the US. In order to improve the treatment and outcome of patients with hematologic malignancies, integration of accurate noninvasive molecular biomarkers to diagnose, monitor therapeutic response and identify disease subtype are critical. Recent advances in next generation sequencing (NGS) have accelerated the utilization of circulating nucleic acids for the development of non-invasive disease biomarkers. We have developed an RNA-Seq platform that allows robust quantification of the circulating cell-free messenger RNA (cf-mRNA) whole transcriptome. Here, we conducted cf-mRNA profiling on plasma samples collected from multiple myeloma and acute myeloid leukemia patients to investigate the feasibility of cell-free transcriptomic profiling as a monitoring tool for hematologic malignancies following bone marrow transplantation and therapeutic treatment.
Methods: We performed cf-mRNA RNA-Sequencing on 96 longitudinally collected plasma samples from 3 multiple myeloma and 3 acute myeloid leukemia patients. Cf-mRNA profiles of patients were evaluated using GTEx (tissue type) and Blueprint (cell type), and dysregulation of gene-expression signatures were assessed following bone marrow transplantation and therapeutic treatment. In addition, we sequenced corresponding whole blood cells and buffy coat for comparison.
Results: Plasma cf-mRNA profiling showed substantially higher proportion of transcripts from megakaryocyte and non-hematopoietic cells relative to whole blood cellular transcripts, suggesting that the molecular profile of cf-mRNA is more suitable for the assessment of gene-expression dysregulation of bone marrow than whole blood. We further report that non-invasive cf-mRNA profiling captures gene-expression alterations of cancer patients following chemotherapy and bone marrow transplantation. And we observed dysregulation of hematopoietic lineage-specific transcripts in circulation during bone marrow ablation and reconstitution. Lastly, we used cf-mRNA profiling to identify a malignant Ig clone for multiple myeloma patients and were able to monitor bone marrow reconstitution.
Conclusions: We demonstrated that cf-mRNA profiling is an effective means to non-invasively assess molecular characteristics that are associated with multiple clinical parameters of hematological malignancies. Our study highlights the potential of cf-mRNA Seq as a platform to develop patient monitoring biomarkers for hematologic malignancies.
Citation Format: Shusuke Toden, David A. Ross, Stephen R. Quake, John J. Sninsky. Utilization of Cell free messenger RNA Sequencing for non-invasive molecular profiling of multiple myeloma and Acute Myeloid Leukemia [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 5174.