Endocrine Abstracts

Molecular basis of the bone disorders in patients with acromegaly are largely unknown.

Objective: To investigate microRNAs (miRNA) expression profiles that regulate bone metabolism in plasma samples from patients with acromegaly.

Materials and methods: Fasting plasma samples were taken from consecutive subjects with biochemically confirmed active acromegaly and healthy volunteers matched by age, sex and BMI. IGF1 was measured by an electrochemiluminescence assay on a Liaison. Total RNA isolation from plasma samples with on-column digestion of the genomic DNA was carried out with miRNeasy Mini Kit on the automatic station ‘QIAcube’. Reverse transcription was carried out using a TaqMan Advanced miRNA cDNA Synthesis Kit. MicroRNA expression analysis was performed by Real-Time PCR on StepOnePlus instrument with TaqMan Advanced miRNA Assay.

Results: 22 subjects with acromegaly mean age 40 (CI 95% 36–44) years old, 17 females and 5 males, BMI – 28 (CI 95% 25–31) kg/m² were enrolled along with 18 healthy control subjects (17 females, 1 male) matched by age P=0.205 and BMI P=0.253. Mean IGF-1 in subjects with acromegaly – 752 (CI 95% 577–926) ng/ml was higher as compared to healthy control − 195 (CI 95% 139-251) ng/ml (P<0.001). Among the 28 miRNAs studied, expression of miRNA-320a 12.2 (CI 95% 4.3 – 20.2, P=0.056) was increased in patients with acromegaly as compared to healthy volunteers. The revealed change negatively affects the level of β-catenin and Runt-related transcription factor 2 (RUNX2) and promotes suppression of chondrogenesis. However, after applying the correction of multiple comparisons, the change in the level of miRNA-320a was statistically insignificant (q=0.605), which is most likely due to the insufficient sample size.

Conclusion: Plasma miRNA-320a can be considered as a potential diagnostic marker of osteoporosis.