Yujiro Nakano, Takanobu Yoshimoto, Ryo Watanabe, Masanori Murakami, Tatsuya Fukuda, Kazutaka Saito, Yasuhisa Fujii, Takumi Akashi, Toshihiro Tanaka, Tetsuya Yamada, Mitsuhide Naruse, and Yoshihiro Ogawa
The pathophysiology of aldosterone-producing adenomas (APAs) has been intensively investigated using genetic and epigenetic approaches. However, the role of miRNAs in APA is not fully understood. The present study profiled miRNAs in APAs as an exploratory approach to elucidate their pathophysiological roles in APAs.
Tissues of APAs and other adrenocortical adenomas were obtained from patients who underwent adrenalectomy.
Candidate miRNAs differentially detected from samples were examined by whole miRNA sequencing. The expression of candidate miRNAs in APA tissues were further validated by real-time quantitative polymerase chain reaction (qPCR). Further, differential miRNA expression between APAs with and without KCNJ5 somatic mutations was examined. Prediction of miRNA target genes was performed by bioinformatics analysis. For specific miRNAs, correlation analysis between the levels of their target genes and CYP11B2 was analyzed in APA tissues.
Our study determined differential expression of six miRNAs in APA or APA with KCNJ5 mutations. We further demonstrated that miR299 levels were negatively correlated with mRNA levels of CACNB2, which encodes the beta-subunit of the L-type calcium channel. Additionally, we found significant correlations among miR299, CACNB2, and CYP11B2 levels in APA tissues.
Our study suggests the possible pathophysiological involvement of specific miRNAs in calcium signaling and aldosterone hypersecretion in APAs. Further studies, including in vitro analyses, are required to clarify these findings.
Masanori Murakami, Takanobu Yoshimoto, Kazuhiko Nakabayashi, Kyoichiro Tsuchiya, Isao Minami, Ryotaro Bouchi, Hajime Izumiyama, Yasuhisa Fujii, Kosei Abe, Chiharu Tayama, Koshi Hashimoto, Takayoshi Suganami, Ken-ichiro Hata, Kazunori Kihara, and Yoshihiro Ogawa
The pathophysiology of aldosterone-producing adenomas (APA) has been investigated intensively through genetic and genomic approaches. However, the role of epigenetics in APA is not fully understood. In the present study, we explored the relationship between gene expression and DNA methylation status in APA.
We conducted an integrated analysis of transcriptome and methylome data of paired APA-adjacent adrenal gland (AAG) samples from the same patient. The adrenal specimens were obtained from seven Japanese patients with APA who underwent adrenalectomy. Gene expression and genome-wide CpG methylation profiles were obtained from RNA and DNA samples that were extracted from those seven paired tissues.
Methylome analysis showed global CpG hypomethylation in APA relative to AAG. The integration of gene expression and methylation status showed that 34 genes were up-regulated with CpG hypomethylation in APA. Of these, three genes (CYP11B2, MC2R, and HPX) may be related to aldosterone production, and five genes (PRRX1, RAB38, FAP, GCNT2, and ASB4) are potentially involved in tumorigenesis.
The present study is the first methylome analysis to compare APA with AAG in the same patients. Our integrated analysis of transcriptome and methylome revealed DNA hypomethylation in APA and identified several up-regulated genes with DNA hypomethylation that may be involved in aldosterone production and tumorigenesis.
Martin Reincke, Adriana Albani, Guillaume Assie, Irina Bancos, Thierry Brue, Michael Buchfelder, Olivier Chabre, Filippo Ceccato, Andrea Daniele, Mario Detomas, Guido Di Dalmazi, Atanaska Elenkova, James Findling, Ashley B Grossman, Celso E Gomez-Sanchez, Anthony P Heaney, Juergen Honegger, Niki Karavitaki, Andre Lacroix, Edward R Laws, Marco Losa, Masanori Murakami, John Newell-Price, Francesca Pecori Giraldi, Luis G Pérez‐Rivas, Rosario Pivonello, William E Rainey, Silviu Sbiera, Jochen Schopohl, Constantine A Stratakis, Marily Theodoropoulou, Elisabeth F C van Rossum, Elena Valassi, Sabina Zacharieva, German Rubinstein, and Katrin Ritzel
Corticotroph tumor progression (CTP) leading to Nelson’s syndrome (NS) is a severe and difficult-to-treat complication subsequent to bilateral adrenalectomy (BADX) for Cushing’s disease. Its characteristics are not well described, and consensus recommendations for diagnosis and treatment are missing.
A systematic literature search was performed focusing on clinical studies and case series (≥5 patients). Definition, cumulative incidence, treatment and long-term outcomes of CTP/NS after BADX were analyzed using descriptive statistics. The results were presented and discussed at an interdisciplinary consensus workshop attended by international pituitary experts in Munich on October 28, 2018.
Data covered definition and cumulative incidence (34 studies, 1275 patients), surgical outcome (12 studies, 187 patients), outcome of radiation therapy (21 studies, 273 patients), and medical therapy (15 studies, 72 patients).
We endorse the definition of CTP-BADX/NS as radiological progression or new detection of a pituitary tumor on thin-section MRI. We recommend surveillance by MRI after 3 months and every 12 months for the first 3 years after BADX. Subsequently, we suggest clinical evaluation every 12 months and MRI at increasing intervals every 2–4 years (depending on ACTH and clinical parameters). We recommend pituitary surgery as first-line therapy in patients with CTP-BADX/NS. Surgery should be performed before extrasellar expansion of the tumor to obtain complete and long-term remission. Conventional radiotherapy or stereotactic radiosurgery should be utilized as second-line treatment for remnant tumor tissue showing extrasellar extension