Anti­tumor properties of FoxO1 in YD­9 oral squamous cell carcinoma cells.

Oral squamous cell carcinoma (OSCC) is a tumor with a poor prognosis and a high recurrence rate. Despite its high annual incidence worldwide, appropriate therapeutic strategies have not yet been developed. Consequently, the 5­year survival rate for OSCC is low when advanced stages or recurrence is diagnosed. Forkhead transcriptional factor O1 (FoxO1) is a key mediator for maintaining cellular homeostasis. FoxO1 can function as a tumor suppressor as well as an oncogene depending on the cancer type. Therefore, the precise molecular functions of FoxO1 need to be validated, considering intracellular factors and the extracellular environment. To the best of our knowledge, however, the roles of FoxO1 in OSCC have not yet been defined. The present study examined FoxO1 levels under pathological conditions (oral lichen planus and oral cancer) and selected an appropriate OSCC cell line (YD­9). Crispr/Cas9 was used to generate FoxO1­deficient YD­9 cells in which the protein levels of phospho ERK and phospho STAT3 were upregulated, promoting cancer proliferation and migration. In addition, FoxO1 reduction increased the levels of the cell proliferation markers phospho H3 (Ser10) and PCNA. FoxO1 loss significantly reduced cellular ROS levels and apoptosis in YD­9 cells. Collectively, the present study demonstrated that FoxO1 exerted an anti­tumor effect by suppressing proliferation and migration/invasion but promoting oxidative stress­linked cell death in YD­9 OSCC cells.

FoxO1 Controls Redox Regulation and Cellular Physiology of BV-2 Microglial Cells.

Microglia are brain-resident macrophage-like cells that play critical roles in diverse pathophysiological conditions, including development, neurogenesis, tissue damage, and pathogenic infection. Identifying molecular switches that govern the fate and function of microglia would be valuable for maintaining brain homeostasis. Forkhead box protein O1 (FoxO1) is the first identified gene in the FoxO family and serves as a potent transcriptional regulator that participates in development, apoptosis, metabolism, and stress response. It has been recently reported that FoxO1 expression is downregulated in human microglia with age, but the role of FoxO1 has not been characterized so far. In the present study, we investigated the molecular function of FoxO1 in microglia by utilizing BV-2 cells. By generating FoxO1-deficient BV-2 microglia through Crispr/Cas9 system, we analyzed the influence of FoxO1 on redox status, metabolism, and polarization of microglia. Our data clearly showed that FoxO1 deficiency suppressed oxidative stress and cell death. In addition, FoxO1 level could modulate metabolic status and polarizing potential of BV-2 microglia. FoxO1 might be a critical element for the regulation of microglial cell physiology and the maintenance of the brain homeostasis.

Antioxidant and Antiproliferative Activity of Finasteride against Glioblastoma Cells.

Glioblastoma is an actively growing and aggressive brain tumor with a high propensity of recurrence. Although the surgical removal of tumor mass is the primary therapeutic option against glioblastoma, supportive pharmacotherapy is highly essential due to incredibly infiltrative characteristic of glioblastoma. Temozolomide, an FDA-approved alkylating agent, has been used as a first-line standard pharmacological approach, but several evident limitations were repeatedly reported. Despite additional therapeutic options suggested, there are no medications that successfully prevent a recurrence of glioblastoma and increase the five-year survival rate. In this study, we tested the possibility that finasteride has the potential to be developed as an anti-glioblastoma drug. Finasteride, an FDA-approved medication for the treatment of benign prostate hyperplasia and androgenic alopecia, is already known to pass through the blood-brain barrier and possess antiproliferative activity of prostate epithelial cells. We showed that finasteride inhibited the maintenance of glioma stem-like cells and repressed the proliferation of glioblastoma. Mechanistically, finasteride lowered intracellular ROS level by upregulating antioxidant genes, which contributed to inefficient ß-catenin accumulation. Downregulated ß-catenin resulted in the reduction in stemness and cell growth in glioblastoma.