Abstract. In order to improve our understanding of the potential preventive and therapeutic role of metformin, the present study aimed to investigate the capability of low-dose metformin in the efficient inhibition of cancer development and the reduction of the metastasis of endometrial adenocarcinoma type I and primary endometrial epithelial cells (eEPs), with the drug acting as a treatment in a hyperinsulinemic environment exposed to high and normal glucose conditions. The Ishikawa endometrial adenocarcinoma cell line and primary eEPs were exposed to an environment with high (17 mM) or normal glucose (5 mM) and treated with insulin, low-dose metformin (0.1 mM) or a combined treatment. Metastatic potential was assessed by migration and invasion assays, and relative cell proliferation was determined. Metformin at a low dose potently inhibited the insulin action, decreasing the ability of the endometrial cancer (EC) cell line to migrate and invade in a high and normal glucose environment, and decreasing the migration ability of the primary eEPs. In the EC cell line, the insulin treatment increased the proliferation, without any subsequent reduction of proliferation by the addition of 0.1 mM metformin; however, relative cell proliferation sensitivity to metformin was observed in the range between 1 and 5 mM regardless of the glucose concentration present. Overall, metformin at 0.1 mM is not efficient enough to decrease the proliferation in an EC cell line. However, at this concentration, metformin can inhibit the insulin action in endometrial epithelial cancer cells, demonstrating an anti-metastatic effect in high and normal glucose environments.

Objective To evaluate the reproductive and histological characteristics of fresh cultured ovarian tissue from transgender male patients. Methods An in vitro pilot study in which samples were collected during sex reassignment surgery for transgender male patients. The ovarian cortex was cut into fragments of 2 mm, 3 mm, and 4 mm, and placed in a 96-well plate suitable for cultivation at days 0, 2, 4, 6, and 8, when the histology was analyzed. Results Stromal hyperplasia was observed in all samples, and it was not associated with the obtainment of primordial or primary follicles. Peripheral reduction in cell count was also a recurrent finding. Primordial and primary follicles were identified with a heterogeneous pattern in fragments from the same patient and from different patients, and follicles in more advanced stages of development (secondary and antral) were not found. There was an association between the diameter of the ovarian fragments and the identification of primary follicles (p = 0.036). The number of days in culture was associated with histological signs of tissue damaging in the fragments (p = 0.002). The total number of follicles identified in the samples with 2 mm in diameter was significantly lower than in those that measured 4 mm in diameter (p = 0.031). Conclusion A diameter of 4 mm is suitable for ovarian tissue culture with the benefit of ease of handling. Even after prolonged exposure to testosterone, the ovarian fragments presented primordial and primary follicles, maintaining viability throughout the days they were exposed to the culture. Freezing the ovarian cortex of transgender patients who will undergo surgery for gender reassignment would be an interesting option, in the future, for the preservation of fertility.