CD56+ cells in aldosterone-producing adenomas exhibited a higher variant allele frequency for pathogenic KCNJ5 mutations than CD56- cells and co-expressed CYP11B2.
CD56+ cells in aldosterone-producing adenomas harbor a higher mutational burden, particularly in KCNJ5, and co-express CYP11B2, suggesting they are the primary aldosterone-producing population.
Objective: Background and Objective Primary aldosteronism (PA) is the most common form of secondary hypertension, often caused by aldosterone-producing adenomas (APAs). These benign adrenal tumors frequently harbor somatic mutations in ion channel-related genes such as KCNJ5, CLCN2, CACNA1D, CACNA1H, ATP1A1, CTNNB1, CADM1, ATP2B3, SLC30A1, GNA11/Q and PRKACA, leading to dysregulated intracellular calcium homeostasis and excessive aldosterone production. CD56, also known as the neural adhesion molecule (NCAM1), is a marker of aldosterone-producing cells in the adrenal zona glomerulosa and in APAs. CD56+ cells express significantly higher levels of CYP11B2 than CD56- cells. However, limited data are available on their mutational landscape and their contribution to tumor heterogeneity. The objective of this study was to investigate the genetic and functional heterogeneity of APAs by analyzing mutational landscapes and the role of CD56+ cells in aldosterone overproduction. Design and method: CD56+ and CD56- cells were isolated from APA tissues using immunomagnetic beads coated with anti-CD56 antibody. DNA was extracted from APA tissues, CD56+ cells, and CD56- cells, and targeted NGS was performed to assess mutational status. Immunohistochemistry was performed to assess the localization and co-expression of CD56, CYP11B1, and CYP11B2 in APA tissue sections. Results: Targeted NGS identified multiple somatic mutations across APA tissues and sorted cell populations, including variants in key genes such as KCNJ5, CACNA1D, and CLCN2. In samples harboring pathogenic KCNJ5 mutations, CD56+ cells consistently showed a higher VAF than CD56- cells and bulk APA tissue, indicating enrichment of the mutation in this subpopulation. In KCNJ5-negative APAs, other mutations were detected at variable frequencies across cell fractions, suggesting differential mutational landscapes. Immunohistochemistry revealed co-localization of CD56 with CYP11B2 and CYP11B1, supporting the presence of hybrid steroidogenic phenotypes. Conclusions: Our findings support the hypothesis that CD56+ cells constitute the primary aldosterone-producing population within APAs, with a higher mutational burden, particularly in KCNJ5, and co-expressing CYP11B2. Integrating IHC, mutational, and transcriptomic data will provide deeper insights into aldosterone biosynthesis and may guide future targeted diagnostics or therapies.
Khatoon et al. (Fri,) conducted a other in Primary aldosteronism (aldosterone-producing adenomas). CD56+ cells vs. CD56- cells and bulk APA tissue was evaluated on Mutational status and co-expression of CD56, CYP11B1, and CYP11B2. CD56+ cells in aldosterone-producing adenomas exhibited a higher variant allele frequency for pathogenic KCNJ5 mutations than CD56- cells and co-expressed CYP11B2.