Synthesis and antimitotic activity of novel 2-methoxyestradiol analogs. Part III

Utilizing Estra-1,3,5,16-Tetraene Scaffold: Design and Synthesis of Nitric Oxide Donors as Chemotherapeutic Resistance Combating Agents in Liver Cancer

A new series of nitric oxide-releasing estra-1,3,5,16-tetraene analogs (NO-∆-16-CIEAs) was designed and synthesized as dual inhibitors for EGFR and MRP2 based on our previous findings on estra-1,3,5-triene analog NO-CIEA 17 against both HepG2 and HepG2-R cell lines. Among the target compounds, 14a (R-isomer) and 14b (S-isomer) displayed potent anti-proliferative activity against both HepG2 and HepG2-R cell lines in comparison to the reference drug erlotinib. Remarkably, compound 14a resulted in a prominent reduction in EGFR phosphorylation at a concentration of 1.20 µM with slight activity on the phosphorylation of MEK1/2 and ERK1/2. It also inhibits MRP2 expression in a dose-dependent manner with 24% inhibition and arrested the cells in the S phase of the cell cycle. Interestingly, compound 14a (estratetraene core) exhibited a twofold increase in anti-proliferative activity against both HepG2 and HepG2-R in comparison with the lead estratriene analog, demonstrating the significance of the designed ∆-16 unsaturation. The results shed a light on compound 14a and support further investigations to combat multidrug resistance in chemotherapy of hepatocellular carcinoma patients.

Recent Advances in chemistry and pharmacology of 2-methoxyestradiol: An anticancer investigational drug

2-Methoxyestradiol (2ME2), an estrogen hormone metabolite is a potential cancer chemotherapeutic agent. Presently, it is an investigational drug under various phases of clinical trials alone or in combination therapy. Its anticancer activity has been attributed to its antitubulin, antiangiogenic, pro-apoptotic and ROS induction properties. This anticancer drug candidate has been explored extensively in last twenty years for its detailed chemistry and pharmacology. Present review is an update of its chemistry and biological activity. It also extends an assessment of potential of 2ME2 and its analogues as possible anticancer drug in future.

Synthesis of sex hormone-derived modified steroids possessing antiproliferative activity

During recent years intensive research has been focused on the synthesis of structurally modified steroid hormones in order to obtain compounds with beneficial biological activity such as cell-growth inhibition. Experimental results have revealed that some steroidal derivatives possess direct cytostatic effect on cancer cells in a hormone receptor-independent manner. After a brief account on the most important biological function and characteristics of the naturally occurring sex hormones in physiological and pathological conditions, structural modifications of estrane and androstane scaffolds are discussed in detail. The review covers literature publications (from 2002 to 2012) relating to the synthesis and antiproliferative activity of semisynthetic sex hormone-derived molecules containing simple or heterocyclic substituents. The compounds reviewed are divided into three main categories according to their sterane framework and the nature of substitution. This article is part of a Special Issue entitled "Synthesis and biological testing of steroid derivatives as inhibitors".

Synthesis of 2-substituted 17β-hydroxy/17-methylene estratrienes and their in vitro cytotoxicity in human cancer cell cultures

Synthesis of various types of 2-(alkylaminomethyl) and 2-(aroyl) 17β-estradiol analogs are reported. The synthesis of similar types of 2-substituted 17-methylene estratriene analogs was also achieved. Synthesis of chalcone derivatives of 17β-estradiol and 17-methylene estratriene were also realized. All these 2-substituted estratrienes were tested for their antiproliferative activity by using four different cell lines from colon, lung, glioma and breast cancers. Among the various 2-substituted estratrienes, the compounds 10d, 14a-h and 17e were found to have in vitro antiproliferative activity comparable to that of parent analogs 1-4. Comparison of the SAR pattern of these 2-susbtituted estratriene derivatives confirmed that relatively, 17-methylene estratrienes are more active than that of 17β-estradiol analogs.