Alcohol exposure, as a widespread environmental factor, is highly toxic and teratogenic. Embryonic stem cells (ESCs) are pluripotent and key to development, and their gene expression is tightly regulated, allowing the cells to differentiate without self-renewal. Numerous studies showed that alcohol is an important factor affecting the differentiation of ESCs. In this paper, we systematically summarized four major molecular mechanisms underlying alcohol associated differentiation of ESCs: (1) inhibition of the Wnt signaling pathway; (2) restriction of the mitogen-activated protein kinase/extracellular signal-regulated kinase (MAPK/ERK) pathway; (3) alteration of the expression of pluripotent transcription factors; and (4) activation of the nuclear transcriptional program. Through the above mechanisms, alcohol induces aberrant expression of differentiation-related genes and alters the direction of cellular differentiation towards specific lineages, thereby affecting normal embryonic development. Based on the studies on ESCs modeling and other in vitro and in vivo differentiation experiments, the molecular basis of how alcohol affects differentiation by interfering with signaling networks and transcriptional regulation was elucidated, and the results of current research in this field were also summarized, which is crucial for understanding alcohol-mediated toxic effects.

Objective: To explore the activity of auranofin against ovarian cancer cells and its possible molecular mechanism． Methods : The dose-response survival curve and IC50 of auranofin on ovarian cancer cell lines ，SKOV3，Caov3 and SW626 cells and immortalized normal human embryonic kidney HEK-293T cells were determined by CCK-8 method．Cell cycle was determined by flow cytometry．The levels of total glutathione ( GSH) ，reduced GSH and glutathione disulfide ( GSSG) ，thioredoxin reductase (TrxR) and reactive oxygen species (ROS) in cells were determined by microplate reader，and the reduced GSH / GSSG ratio was calculated．Western blot was used to determine the expression of cyclin dependent kinases( CDK) 4，CDK6，Cyclin D1，P53，p-P53 and MDM2 in SKOV3 and Caov3 ovarian cancer cells. Results : Compared with HEK-293T cells，the dose-response survival curves and IC50 values of SKOV3，Caov3 and SW626 cells showed that ovarian cancer cells were more sensitive to auranofin (P＜0. 05) ．After SKOV3 and Caov3 cells were treated with the dose of respective IC50 concentrations of auranofin，compared with the untreated cells group，the Auranofin IC50 group cells' intracellular levels of GSH，the ratio of reduced GSH / GSSG and the activity of TrxR decreased (t = 25. 11 /31. 18，14. 72 /19. 92，43. 30 /10. 74， all P＜0. 05) ，and the levels of ROS increased (t = 23. 82 /27. 71，P＜0. 05) ; cells number at G0 / G1 phases increased，with cells number at S and G2 phases decreased (P＜0. 05) ; and the expression levels of cell cycle-related proteins CDK4，CDK6，Cyclin D1 and the P53-specific E3 ubiquitin ligase MDM2 were down-regulated (t = 7. 51 /15. 59，17. 32 /11. 26，20. 78 /20. 78，24. 25 /17. 32，all P＜0. 05) ，while the expression levels of P53 and p-P53 were up-regulated (t = 17. 32 /24. 25，12. 12 /10. 39，all P ＜0. 05) ． Conclusion Auranofin causes oxidative stress in ovarian cancer cells by inhibiting TrxR activity，and by partially degrading MDM2 to stabilize and acti- vate P53，so as to block the cancer cells in G0 / G1 phase，and exert anti-ovarian cancer activities.