PT - JOURNAL ARTICLE AU - Shaolong Cao AU - Jennifer R. Wang AU - Shuangxi Ji AU - Peng Yang AU - Jingxiao Chen AU - Matthew D. Montierth AU - John Paul Shen AU - Jaewon James Lee AU - Paola A Guerrero AU - Kaixian Yu AU - Julie Livingstone AU - Vinayak Bhandari AU - Shawna M Hubert AU - Najat C. Daw AU - P. Andrew Futreal AU - Eleni Efstathiou AU - Bora Lim AU - Andrea Viale AU - Jianjun Zhang AU - Anirban Maitra AU - Scott Kopetz AU - Peter Campbell AU - Terrence P. Speed AU - Paul C. Boutros AU - Alfonso Urbanucci AU - Hongtu Zhu AU - Jonas Demeulemeester AU - Peter Van Loo AU - Wenyi Wang TI - Differing total mRNA expression shapes the molecular and clinical phenotype of cancer AID - 10.1101/2020.09.30.306795 DP - 2020 Jan 01 TA - bioRxiv PG - 2020.09.30.306795 4099 - http://biorxiv.org/content/early/2020/10/02/2020.09.30.306795.short 4100 - http://biorxiv.org/content/early/2020/10/02/2020.09.30.306795.full AB - Cancers can vary greatly in their transcriptomes. In contrast to alterations in specific genes or pathways, the significance of differences in tumor cell total mRNA content is poorly understood. Studies using single-cell sequencing or model systems have suggested a role for total mRNA content in regulating cellular phenotypes. However, analytical challenges related to technical artifacts and cellular admixture have impeded examination of total mRNA expression at scale across cancers. To address this, we evaluated total mRNA expression using single cell sequencing, and developed a computational method for quantifying tumor-specific total mRNA expression (TmS) from bulk sequencing data. We systematically estimated TmS in 5,181 patients across 15 cancer types and observed close correlations with clinicopathologic characteristics and molecular features, where high TmS generally accompanies high-risk disease. At a pan-cancer level, high TmS is associated with increased risk of disease progression and death. Moreover, TmS captures tumor type-specific effects of somatic mutations, chromosomal instability, and hypoxia, as well as aspects of intratumor heterogeneity. Taken together, our results suggest that measuring total mRNA expression offers a broader perspective of tracking cancer transcriptomes, which has important clinical and biological implications.Competing Interest StatementA.M. receives royalties for a pancreatic cancer biomarker test from Cosmos Wisdom Biotechnology, and this financial relationship is managed and monitored by the UTMDACC Conflict of Interest Committee. A.M. is also listed as an inventor on a patent that has been licensed by Johns Hopkins University to Thrive Earlier Detection. J.Z. reports research funding from Merck, Johnson and Johnson, and consultant fees from BMS, Johnson and Johnson, AstraZeneca, Geneplus, OrigMed, Innovent outside the submitted work.