Hui Xiong,Cheng Wang,Zihan Wang,Zhijie Jiang,Jianping Zhou,Jing Yao
Estrogen receptor-positive (ER+) breast carcinoma therapy faces the challenges of estrogen receptors heterogeneity and endocrine therapy resistance. Selectively attacking glutathione (GSH) biosynthesis which is the metabolic vulnerability of ER+ breast carcinoma could bypass conventional treatment limitations through blocking oxidative stress disorders-driven tumor cell proliferation . Herein, we developed drug-organics-inorganics self-assembled nanosystem (DFTA) with doxorubicin (DOX) as chemotherapeutic agent, ferric chloride (FeCl 3 ) as ferroptosis inducer and tannic acid (TA) as activator of superoxide dismutase (SOD)-like reaction in intracellular cascade for the combined therapy in ER+ breast carcinoma. DFTA displayed a particle size of 106.4 ± 0.7 nm with flat irregular nanonetwork-like shape and predominant photothermal effect produced in the assembly process. The drug release from DFTA could be triggered by photothermal excitation efficiently. ELISA analysis showed that DFTA + laser group significantly reduced intracellular GSH level through reactive oxygen species (ROS)-produced intracellular oxidative stress cascade amplification and photothermal therapy (PT)-mediated ROS production. Furthermore, in vivo antitumor efficiency evaluation showed that the tumor inhibition ratio of DFTA + laser was as high as 93.38 % even though the dosage of iron and DOX reduced by about 9 times and 1.5 times respectively. In summary, our study established a high-efficiency nanosystem based on triple combination therapy of chemotherapy, ferroptosis and PT, which might be a promising nanosystem for effective ER+ breast carcinoma therapy.
Runlan Wan,Xi Kong,Youzhe Yang,Siwen Tao,Youyou Chen,Alexander Tobias Teichmann,Frank Heinrich Wieland
The clinical use of the steroidal aromatase inhibitor Formestane (4-hydroxandrostenedione, 4-OHA) in the treatment of advanced ER+ breast cancer has been discontinued, and therefore, interest in this remarkable drug has vanished. As a C-19 sterol, 4-OHA can undergo extensive intracellular metabolism depending on the expression of specific enzymes in the corresponding cells. We used the metabolites 4β-hydroxyandrosterone, 4β-hydroxyepiandrosterone and its 17β-reduced derivative as standards for the proof of catalytic activity present in the cell culture medium and expressed by the isolated enzymes. All of the aldo-keto reductases AKR1C1, AKR1C2, AKR1C3 and AKR1C4 catalysed the reduction of the 3-keto-group and the Δ 4,5 double bond of 4-OHA at the same time. Molecular docking experiments using microscale thermophoresis and the examination of the kinetic behaviour of the isolated enzymes with the substrate 4-OHA proved that AKR1C3 had the highest affinity for the substrate, whereas AKR1C1 was the most efficient enzyme. Both enzymes (AKR1C1and AKR1C3) are highly expressed in adipose tissue and lungs, exhibiting 3β-HSD activity. The possibility that 4-OHA generates biologically active derivatives such as the androgen 4-hydroxytestosterone or some 17β-hydroxy derivatives of the 5α-reduced metabolites may reawaken interest in Formestane, provided that a suitable method of administration can be developed, avoiding oral or intramuscular depot-injection administration.