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BackgroundThe purpose of this study was to (1) identify specific miRNAs in growth hormones (GH)-secreting pituitary adenomas; (2) determine the relationship between the expression of these miRNAs and tumor size, somatostatin analogs treatment, and responsiveness to somatostatin analogs (SSA).MethodsFifteen GH-secreting adenomas patients were treated with lanreotide for 4 months before surgery. Patients with 50% reduction of GH secretion by lanreotide were considered as SSA responders, while patients with less than 50% of GH reduction were considered as SSA nonresponders. We analyzed the miRNAs in 21 GH-secreting pituitary adenomas and 6 normal pituitaries by miRCURY™ LNA array and some differentially expressed miRNAs were validated by quantitative real-time PCR.ResultsFifty-two miRNAs were differentially expressed between GH-secreting pituitary adenomas and normal pituitaries. Differential expression of 9 miRNAs was observed between micro- and macro-adenomas. Thirteen miRNAs were differentially expressed between tumor samples from lanreotide-treated patients and those from lanreotide-untreated patients. Seven miRNAs were differentially expressed between SSA responders or GH nonresponders. Several identified miRNAs may be involved in cell proliferation, apoptosis, cancer development and progression.ConclusionsOur results indicate that altered miRNAs expression is involved in GH-secreting pituitary adenomas transformation, which will shed light on the mechanisms for the treatment of acromegaly by SSA. Identification and characterization of the targets of altered miRNAs genes may elucidate molecular mechanisms involved in the pathogenesis of pituitary adenoma.

Objective: To investigate whether 4-month preoperative lanreotide treatment would improve the surgical cure rate of newly diagnosed acromegalic patients with macroadenomas. Design: A prospective, randomised study. Methods: After a baseline evaluation, patients were randomly assigned to 4-month preoperative treatment with lanreotide (starting with 30 mg/2 weeks i.m. and increasing to 30 mg/week i.m. at week 8 if mean GH O2.5 mg/l on GH day curves; pretreatment group, Group 1) or to transsphenoidal surgery (direct surgery group, Group 2). Cure was evaluated 4 months postoperatively primarily by fasting IGF1 less than or equal to age-adjusted upper limit of normal. Results: A pool of 108 patients was randomly divided into two groups. Five patients in each group were lost to follow-up during the study period, so 49 patients in each group were analysed. At baseline, no difference was observed between the two groups. Cure was established in 24 of 49 (49.0%, 95% confidence interval (CI), 35.0-63.0%) pretreated patients (Group 1) versus 9 of 49 (18.4%, 95% CI, 7.6-29.

PET/CT may be useful to detect tumors in patients with equivocal MRI results. C-MET PET/CT can provide valuable diagnostic information when F-FDG PET/CT yields negative results, especially in patients with recurrent microadenomas.

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