ABSTRACT: Purpose: Evaluate the molecular changes associated with melphalan-induced cardiotoxicity and rescue by N-acetyl-L-cysteine (NAC) supplementation. Methods: RNA-Seq analysis was performed to analyze global transcriptome profiles of hiPSC-CMs treated with DMSO (Control group), 20 µM melphalan (Mel group), and 20 µM melphalan with 1 mM NAC (Mel+NAC group), respectively. The Illumina TruSeq technology was used to prepare RNA-Seq libraries, and next-generation sequencing was done via an Illumina HWI-ST1276. RNA sequence reads were aligned to the human reference genome (GRCh38) using STAR v2.5. HTSeq v0.6.1 was used to count the read numbers mapped of each gene, and then Fragments Per Kilobase Million (FPKM) was calculated to estimate gene abundance. Differential expression analysis was performed using the DESeq2 R package (2_1.6.3). The resulting P-values were adjusted using the Benjamini and Hochberg's approach. Results: As detected by RNA-Seq, more genes were down-regulated than up-regulated by the treatment of melphalan, whereas NAC supplementation resulted in more genes being up-regulated than down-regulated. Among the top 10 up-regulated genes by melphalan treatment, 4 were direct p53 effectors (CDKN1A, EDXR, TNFRSF10C, and GDF15). And among the top 10 down-regulated genes by melphalan treatment, 5 were correlated to cell adhesion (CDH13, CNTN1, SDK1, CTNND2, and PARD3B). In addition, the up- and down-regulation of genes involved in oxidative stress (e.g., DUOX2 and NOX4) following melphalan treatment (Mel vs. control) was attenuated with NAC supplementation (Mel+NAC vs. Control). Similarly, the up- and down-regulation of genes involved in cardiac muscle contraction (e.g., Ca2+ handling proteins CACNA1C, RYR2 and CASQ2 and cardiac contractile proteins TNNC1, ACTC1, TNNC1) and cardiac conduction (e.g., ATP2B2 and ABCC9) following melphalan treatment (Mel vs. Control) was attenuated with NAC supplementation (Mel+NAC vs. Control). Conclusion: NAC ameliorates melphalan-induced alteration of hiPSC-CM transcriptomic profiles.
