Analysis of ARMC5 expression in human tissues.

Mutations in ARMC5 gene have been recently identified as the main cause of Primary Macronodular Adrenocortical Hyperplasia (PMAH). PMAH patients have an ARMC5 germline mutation and, in addition, somatic tissue-specific mutations. This is consistent with the two-hit hypothesis of tumorigenesis and suggests that ARMC5 may be a tumor suppressor gene. As its function is still unclear, we analyzed the expression of the four ARMC5 isoforms in 46 normal human tissues. This showed that at least one ARMC5 isoform is ubiquitously expressed throughout the body; however, only 7 tissues expressed all isoforms, including the adrenal gland and the brain. Interestingly, the highest expression for ARMC5 in the brain is in the pituitary gland. The isoform ARMC5-003 was present in most endocrine tissues including the pituitary, adrenal glands and the pancreas. In this report, we present new data about the ARMC5 expression pattern in human tissues; its wide expression in brain, pituitary gland and other tissues suggest that mutations may be responsible for additional pathologies, beyond what is already known in PMAH and meningiomas. Published by Elsevier B.V.