Metformin is an anti-hyperglycemic agent used to treat diabetes, and recent evidence suggests it has antitumor efficacy. Because growth hormone-secreting pituitary adenoma (GH-PA) patients have a high incidence of diabetes frequently treated with metformin, we assessed the antitumor effect of metformin on GH-PA. We found that metformin effectively inhibited proliferation and induced apoptosis in the GH-PA cell line GH3. We detected a decrease in mitochondrial membrane potential (MMP), an increase in expression of pro-apoptotic proteins, and a decrease in expression of an anti-apoptotic protein in metformin-treated GH3 cells, which suggests involvement of the mitochondrial-mediated apoptosis pathway. Inhibition of AMPK, which is activated by metformin, failed to reverse the antiproliferative effect. ATF3 was upregulated by metformin, and its knockdown significantly reduced metformin-induced apoptosis. In addition, GH secretion was inhibited by metformin through suppression of STAT3 activity independently of AMPK. Metformin also significantly suppressed cellular proliferation and GH secretion in primary human GH-PA cells. Metformin also significantly inhibited GH3 cell proliferation and GH secretion in vivo. ATF3 upregulation and p-STAT3 downregulation were confirmed in xenografts. These findings suggest metformin is a potentially promising therapeutic agent for the treatment of GH-PA, particularly in patients with diabetes.

UCB transplantation may be an approach that could somewhat improve C-peptide levels in patients with T2DM.

Objective: Moderate-to-severe subacute thyroiditis is clinically managed with 6–8 weeks of glucocorticoid therapy. However, no studies have evaluated short-term prednisone treatment for subacute thyroiditis. Methods: This 24-week, prospective, single-blind, randomized controlled study enrolled patients (aged 18–70) with subacute thyroiditis who were hospitalized between August 2013 and December 2014. Patients with moderate-to-severe symptoms were randomly assigned to receive either 30 mg/d prednisone for 1 week, followed by 1 week of nonsteroidal anti-inflammatory drugs, or the conventional 6-week prednisone therapy. The primary endpoint was intergroup differences in treatment efficacy at the end of treatment course. Secondary endpoints included between-group differences in post-withdrawal adverse effect parameters and thyroid function at weeks 6, 12, and 24. Results: We screened 96 patients, randomized 52 participants, and 50 completed the study. Efficacy and recurrence rates were not significantly different at withdrawal in both groups ( P=0.65). At treatment discontinuation, parathyroid hormone (28.8 vs 38.9 pg/mL, p=0.011) and systolic blood pressure (113.9 vs 122.4 mmHg, p=0.023) were significantly lower in the experimental group than in the control group. There were no significant intergroup differences in other secondary endpoints at withdrawal and in thyroid function at weeks 6, 12, and 24. Conclusions: Fewer side effects of glucocorticoids and similar efficacy and recurrence rates were observed with short-term prednisone compared with in the 6-week treatment for subacute thyroiditis. Short-term prednisone with a better safety profile may be an alternative strategy for ameliorating moderate-to-severe symptoms of subacute thyroiditis.

BackgroundAdrenal corticomedullary mixed tumours are very rare. Its mechanism is rarely reported. Here we report the first case of a corticomedullary mixed tumour resembling a “small adrenal gland” with distinct arrangement of the cortical and medullary layers. We further hypothesize regarding the tumorigenic mechanism of this tumour.Case presentationA 58-year man had been diagnosed with diabetes and hypertension for 3 years. His 24-h urine vanillylmandelic acid (VMA) levels were slightly elevated. An abnormal circadian cortisol rhythm was noted, and his cortisol levels were not suppressed by dexamethasone. Abdominal computed tomography (CT) revealed a right adrenal gland lesion (diameter, 30 × 38 mm), while an enhanced CT showed enhancement and hypervascularization. The tumour was positive for adrenocorticotropic hormone, chromogranin A (CGA), and steroidogenic factor-1 (SF-1) on the tumour surface. Acetaldehyde dehydrogenase 1(ALDH1), CD44, CD133, Nestin, Nerve growth factor receptor (NGFR), and Sex determining region y-box 9(SOX9) staining were positive. Although administration of medications for diabetes and hypertension was stopped until surgery was performed, the blood sugar level and blood pressure were maintained after surgery.ConclusionsThis is the first report about a possible mechanism by which cancer stem cells induce adrenal corticomedullary tumours.