Izabella Czajka-Oraniec, Wojciech Zgliczynski, Alina Kurylowicz, Michal Mikula and Jerzy Ostrowski
Aromatase cytochrome P45019 (CYP19) is a key enzyme in estrogen biosynthesis, and polymorphisms within its gene are associated with an increased risk of estrogen-dependent diseases. Enhanced estrogen stimulation of breast tissue in men may lead to gynecomastia. We assessed whether intron 4 (TTTA)n repeat and TCT deletion/insertion polymorphisms and an exon 10 (3′-UTR) C/T single nucleotide polymorphism of CYP19 are associated with gynecomastia.
We performed a genetic association study of 100 patients referred to the endocrinological outpatient clinic with breast glandular tissue enlargement confirmed by clinical and ultrasound examinations and 99 healthy volunteers without gynecomastia. Microsatellite (TTTA)n and insertion/deletion polymorphisms were studied using capillary electrophoresis, and the C/T polymorphism in the 3′-UTR was analyzed using the TaqMan assay.
Significantly increased risk of gynecomastia was found in subjects carrying a CYP19 exon 10 T allele that was previously related to the high aromatase activity. Frequency of the TT genotype was significantly higher in patients when compared with controls (40.6 vs 26.3%; TT versus CT and CC genotypes; P
c<0.05). We found strong linkage disequilibrium between the alleles of studied polymorphic loci. T allele in the 3′-UTR was in linkage disequilibrium with the long alleles of the intron 4 polymorphism, mainly (TTTA)11. However, our findings did not show significant correlation of alleles having more than nine TTTA repeats with gynecomastia.
The CYP19 polymorphisms might contribute to the incidence of gynecomastia, but further studies in larger groups are needed to confirm these results.
Mateusz Bujko, Paulina Kober, Joanna Boresowicz, Natalia Rusetska, Agnieszka Paziewska, Michalina Dąbrowska, Agata Piaścik, Monika Pękul, Grzegorz Zieliński, Jacek Kunicki, Wiesław Bonicki, Jerzy Ostrowski, Janusz A Siedlecki and Maria Maksymowicz
Pituitary corticotroph adenomas commonly cause Cushing’s disease (CD) but part of these tumours are hormonally inactive (silent corticotroph adenomas, SCA). USP8 mutations are well-known driver mutations in corticotrophinomas. Differences in transcriptomic profiles between functioning and silent tumours or tumours with different USP8 status have not been investigated.
Design and methods
Forty-eight patients (28 CD, 20 SCA) were screened for USP8 mutations with Sanger sequencing. Twenty-four patients were included in transcriptomic profiling with Ampliseq Transcriptome Human Gene Expression Core Panel. The entire patients group was included in qRT-PCR analysis of selected genes expression. Immunohistochemistry was used for visualization of selected protein.
We found USP8 mutation in 15 patients with CD and 4 SCAs. USP8 mutations determine molecular profile of the tumours as showed by hierarchical clustering and identification of 1648 genes differentially expressed in USP8-mutated and USP8-wild-type tumours. Mutations affect many molecular pathways as observed in Gene Set Enrichment analysis. USP8-mutated adenomas showed higher level of POMC, CDC25A, MAPK4 but lower level of CCND2, CDK6, CDKN1B than USP8-wt tumours. Eighty-seven genes differentially expressed between CD-related adenomas and SCAs were found, including those involved in cell signalling (GLI2, DLC1, TBX2, RASSF6), cell adhesion (GJA1, CDH6), ion transport (KCNN4, KCNJ5) and GABA signalling (GABBR2, GABRD).
USP8 mutations occur in functioning and silent corticotrophinomas. They have pleiotropic effect, not limited to EGFR signalling, and affect expression levels of many genes involved in different pathways. Expression of GABA-related genes GABBR2, GNAL, GABARD and KCNJ5 correspond to functional status of the tumours.