Long and short-read transcriptome profiling of human lung cancer cell lines

Purpose: The aim of this study is to compare different long-read sequencing platforms using reference lung adenocarcinoma cell lines and spike-in controls. Methods - Cell Culture: Lung adenocarcinoma cell lines NCI-H1975 and HCC827 from a range of passages (2-4) were grown on 3 separate occasions in Roswell Park Memorial Institute (RPMI) 1640 medium with 10% fetal calf serum and 1% penicillin-streptomycin. Methods - RNA preparation: mRNA was extracted using a Qiagen RNA miniprep kit and purified using the NEBNext® Poly(A) mRNA Magnetic Isolation Module (E7490). Purified mRNA spiked with sequins was used for Next Generation Sequencing library preparation using the NEBNext Ultra II Directional RNA Library Prep Kit (Illumina) and the cRNA-PCR Barcoding (SQK-PCS109 with SQK-PBK004) kit (ONT). Completed libraries were sequenced on NextSeq 500 (Illumina) and PromethION (ONT). Iso-Seq libraries were prepared and sequenced by Novogene on Sequel II (PacBio). Reads were mapped to known genomic features of the GRCH38 reference genome and RNA sequin decoy chromosome combined sequences at the gene-level and single reads were then summarized into gene-level counts using featureCounts software (Liao et al. 2014). Total RNA was extracted from lung adenocarcinoma cell lines NCI-H1975 and HCC827 (3 independent samples for each cell line). Both mRNA and Total RNA transcriptomes from these samples were profiled by RNA-Seq (Illumina NextSeq 500, Oxford Nanopore Technologies PromethION and PacBio Sequel II)