(4-Picolylamino)-17β-Estradiol derivative and analogues induce apoptosis with death receptor trail R2/DR5 in MCF-7

Meta-stable state photoacid containing β-estradiol fragment with photomodulated biological activity and anti-cancer stem cells properties

Photopharmacology is a young and rapidly developing field of research that offers significant potential for new insights into targeted therapy. While it primarily focuses on cancer treatment, it also holds promise for other diseases. The key feature of photopharmacological agents is the presence of a photosensitive and biologically active component in the same molecule. In our current study, we synthesized a spiropyran-based meta-stable state photoacid containing a fragment of β-estradiol. This compound exhibits negative photochromism and photocontrolled fluorescence under visible-light irradiation due to the initial stabilization of its self-protonated form in solution. We conducted comprehensive biological studies on the HeLa cells model to assess the short- and long-term cytotoxicity of the photoacid, its metabolic effects, its influence on signaling and epithelial-mesenchymal transition super-system pathways, and the proportion of the population enriched with cancer stem cells. Our findings reveal that this derivative demonstrates low cytotoxicity to HeLa cells, yet it is capable of dramatically reducing malignant cells side population enriched in cancer stem cells. Additionally, appropriate structural modification lead to an increase in some other biological effects compared to β-estradiol. In particular, our substance possesses rare properties of AP-1 suppression and demonstrates some pro-oxidant and metabolic effects, which can be regulated by visible light irradiation. As a result, the new estradiol-based photoacid may be considered a promising multi-acting photopharmacological agent for the next-generation anti-cancer research & development.

Apoptotic mechanism of development inhibition in zebrafish induced by esketamine

Esketamine, a widely used intravenous general anesthetic, is also employed for obstetric and pediatric anesthesia, and depression treatment. However, concerns regarding esketamine abuse have emerged. Moreover, the potential in vivo toxicity of esketamine on growth and development remains unclear. To address these concerns, we investigated the effects of esketamine exposure on developmental parameters, cell apoptosis, and gene expression in zebrafish. Esketamine exposure concentration-dependently decreased the heart rate and body length of zebrafish embryos/larvae while increasing the hatching rate and spontaneous movement frequency. Developmental retardation of zebrafish larvae, including shallow pigmentation, small eyes, and delayed yolk sac absorption, was also observed following esketamine treatment. Esketamine exposure altered the expression of apoptosis-related genes in zebrafish heads, primarily downregulating bax, caspase9, caspase3, caspase6, and caspase7. Intriguingly, BTSA1, a Bax agonist, reversed the anti-apoptotic and decelerated body growth effects of esketamine in zebrafish. Collectively, our findings suggest that esketamine may hinder embryonic development by inhibiting embryonic apoptosis via the Bax/Caspase9/Caspase3 pathway. To the best of our knowledge, this is the first study to report the lethal toxicity of esketamine in zebrafish. We have elucidated the developmental toxic effects of esketamine on zebrafish larvae and its potential apoptotic mechanisms. Further studies are warranted to evaluate the safety of esketamine in animals and humans.

Estradiol cypionate inhibits proliferation and promotes apoptosis of gastric cancer by regulating AKT ubiquitination

Gastric cancer is a common gastrointestinal malignancy worldwide, with a high mortality rate and poor prognosis. Multidrug resistance remains a major obstacle to successful treatment for patients. Hence, it is of great significance to develop novel therapies to potentiate the anti-tumor effect. In this study, we have investigated the effect of estradiol cypionate (ECP) on gastric cancer in vitro and vivo. Our data show that ECP inhibited the proliferation, promoted apoptosis, and caused G1/S phase arrest of gastric cancer cells. The mechanism by which ECP promoted apoptosis of gastric cancer cells was related to the downregulation of AKT protein expression caused by the increased ubiquitination modification levels of AKT, which finally inhibited the over-activation of the PI3K-AKT-mTOR signaling pathway. In vivo tumorigenesis experiments showed that ECP significantly inhibited the growth of gastric cancer cells, showing promise for clinical application. The above findings indicate that ECP inhibited the growth of gastric cancer and induced apoptosis through the PI3K /Akt/mTOR pathway. In summary, the efficacy showed in our data suggests that ECP is a promising anti-tumor compound for gastric cancer.