RNA-seq and Mitochondrial DNA Analysis of Adrenal Gland Metastatic Tissue in a Patient with Renal Cell Carcinoma

SIMPLE SUMMARY: We performed mutation analysis of ribonucleic acid sequencing (RNA-seq) and whole mitochondrial genome data from tissues collected from metastatic lesions of a male patient in his 60s with metastatic renal cell carcinoma. We confirmed the common mutation sites of a mitochondrial gene containing the T3394Y, R11,807G, and G15,438R sites. Pathway analysis, using RNA-seq data, confirmed the common mutant pathway between renal cell carcinoma and metastatic adrenal carcinoma as cytokine–cytokine receptor (CCR) interaction. However, no common nuclear gene mutations were identified. The two similar sequences suggest that mtDNA-mutation-driven metastasis to the adrenal gland may affect CCR interactions and cause cancer cells to thrive. ABSTRACT: This study aimed to clarify whether genetic mutations participate in renal cell carcinoma (RCC) metastasis to the adrenal gland (AG). Our study analyzed whole mitochondrial gene and ribonucleic acid sequencing (RNA-seq) data from a male patient in his 60s with metastatic RCC. We confirmed common mutation sites in the mitochondrial gene and carried out Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis using RNA-seq data for RCC and adrenal carcinoma. Furthermore, we confirmed the common mutation sites of mitochondrial genes in which the T3394Y (p.H30Y) site transitioned from histidine (His.; H) to tyrosine (Tyr.; Y) in the NADH dehydrogenase subunit 1 (ND1) gene. The R11,807G (p.T350A) site transitioned from threonine (Thr.; T) to alanine (Ala.; A). Additionally, the G15,438R or A (p.G231D) site transitioned from glycine (Gly.; G) to aspartic acid (Asp.; D) in cytochrome b (CYTB). Furthermore, pathway analysis, using RNA-seq, confirmed the common mutant pathway between RCC and adrenal carcinoma as cytokine–cytokine receptor (CCR) interaction. Confirmation of the original mutation sites suggests that transfer to AG may be related to the CCR interaction. Thus, during metastasis to the AG, mitochondria DNA mutation may represent the initial origin of the metastasis, followed by the likely mutation of the nuclear genes.