Independent clonal evolution in primary pigmented nodular adrenocortical disease: a single-patient multi-omics study

Area of Science:

• Endocrinology
• Genetics
• Oncology

Background:

• Primary pigmented nodular adrenocortical disease (PPNAD) is characterized by adrenal lesions with significant heterogeneity.
• Germline mutations in PRKAR1A, encoding the regulatory subunit 1A of protein kinase A (PKA), are the known cause of PPNAD.
• The single-cell mechanisms driving PPNAD lesion heterogeneity remain unclear.

Purpose of the Study:

• To elucidate the single-cell mechanisms underlying the heterogeneity of lesions in primary pigmented nodular adrenocortical disease (PPNAD).
• To investigate the clonal evolution and molecular features of PPNAD nodules and associated cortisol-producing adenomas (CPA).

Main Methods:

• Multi-omics analysis, including whole-exome sequencing, single-cell RNA sequencing, and spatial transcriptomics, was performed on adrenal tissue from a PPNAD patient.
• Genomic analysis identified biallelic inactivation of PRKAR1A in individual nodules.
• Transcriptomic and spatial analyses characterized cellular phenotypes and signaling pathways within the lesions.

Main Results:

• Each PPNAD nodule represents an independent clonal lesion resulting from germline PRKAR1A mutation and subsequent somatic biallelic inactivation.
• Nodules exhibit zona reticularis features, with upregulation of genes related to androgen synthesis, senescence, and immune activation, suggesting tumor-suppressive characteristics.
• Cortisol-producing adenomas (CPA) showed significant activation of the Wnt/β-catenin pathway, and pseudotime analysis suggested a transition from nodule to adenoma cells.

Conclusions:

• PPNAD nodules originate as independent clonal lesions driven by biallelic PRKAR1A inactivation and possess tumor-suppressive features.
• Activation of the Wnt/β-catenin pathway is implicated in the progression from PPNAD nodules to cortisol-producing adenomas (CPA).
• Independent clonal evolution is the underlying mechanism for the multinodular heterogeneity observed in PPNAD.