A molecular understanding of d-homoestrone-induced G2/M cell cycle arrest in HeLa human cervical carcinoma cells

2-Methoxyestradiol (ME), one of the most widely investigated A-ring-modified metabolites of estrone, exerts significant anticancer activity on numerous cancer cell lines. Its pharmacological actions, including cell cycle arrest, microtubule disruption and pro-apoptotic activity, have already been described in detail. The currently tested d-ring-modified analogue of estrone, d-homoestrone, selectively inhibits cervical cancer cell proliferation and induces a G2/M phase cell cycle blockade, resulting in the development of apoptosis. The question arose of whether the difference in the chemical structures of these analogues can influence the mechanism of anticancer action. The aim of the present study was therefore to elucidate the molecular contributors of intracellular processes induced by d-homoestrone in HeLa cells. Apoptosis triggered by d-homoestrone develops through activation of the intrinsic pathway, as demonstrated by determination of the activities of caspase-8 and -9. It was revealed that d-homoestrone-treated HeLa cells are not able to enter mitosis because the cyclin-dependent kinase 1-cyclin B complex loses its activity, resulting in the decreased inactivation of stathmin and a concomitant disturbance of microtubule formation. However, unlike 2-ME, d-homoestrone does not exert a direct effect on tubulin polymerization. These results led to the conclusion that the d-homoestrone-triggered intracellular processes resulting in a cell cycle arrest and apoptosis in HeLa cells differ from those in the case of 2-ME. This may be regarded as an alternative mechanism of action among steroidal anticancer compounds

Microwave-assisted phospha-Michael addition reactions on 13αestrane core

Novel 16-modified 13 α-estrone derivatives were synthesized via phospha-Michael addition reactions. Transformations of steroidal α,β-unsaturated ketons were carried out under different conditions in a microwave (MW) reactor. The antiproliferative activities of the newly synthesized compounds against a range of human adherent cancer cell lines (SCC-131, SCC154, Hela, SiHa, C33A, A2780, MCF-7, MDA-MB-231, T47D) were investigated by means of MTT assays. Certain potent derivatives were identified

A diabetes hatása a terhes patkány uterus működésére és farmakológiai reaktivitására = The effect of diabetes on the function and pharmacological reactivity of the pregnant rat uterus

A diabetes mellitus (DM) egyike a leggyakoribb terhességi komplikációknak, jelentős anyai és magzati kockázati tényező. Ugyanakkor kevés adat áll rendelkezésre a DM uterus funkciókra gyakorolt hatásával kapcsolatban. Jelen munkánk célja a streptozotocinnal kiváltott DM mymetriális következményeinek feltárása volt patkányban, a gesztációs kor függvényében. Szuperfúziós technikát alkalmazva azt találtuk, hogy DM-ban jelentősen gyorsul az uterus adrenerg denervációja, ami csökkent noradrenalin felvevő kapacitásban nyilvánul meg. A diabetes posztszinaptikus hatásainak leírására kontraktilitási méréseket végeztünk izolált uterusgyűrűkön. Nem terhes állatban a DM fokozza az ?-, és csökkenti a ?-adrenerg stimulációra adott kontrakciós, ill. relaxációs választ. E változásokat részben magyarázza az ?1B-receptorok DM hatására fokozódó mRNS szintű expressziója, amit RT-PCR technikával mutattunk ki. A terhesség alatt nem találtunk jelentős DM-függő eltérést az uterus motoraktivitásában. Megállapítottuk továbbá, hogy DM esetén fokozódik az exogén oxytocin uterotonikus hatása a gesztáció 15. és 21. napján, mely különbség a terminusra (22. nap) megszűnik. Igazoltuk, hogy DM hatására fokozódik a myometriális oxytocin receptorok expressziója. Eredményeinkből valószínűsíthető, hogy ? hasonló humán viszonyok esetén ? a diabetessel szövődött terhességek fokozott koraszülési kockázatának elhárítására az oxytocin-antagonisták lehetnek a legalkalmasabbak. | Diabetes mellitus (DM) is one of the most frequent complications during pregnancy being a significant fetal and maternal risk factor. However our knowledge concerning the effects of DM on uterine functions is limited. The aim of the present work was to elucidate the myometrial consequences of the streptozotocin-induced DM as a function of gestational age of the rat. The results of superfusion experiments revealed that DM increases the adrenergic denervation of the uterus evidenced by a decreased nordrenaline utake capacity . The postsynaptic effects of DM were characterized by recording the contractility of isolated uterine rings exposed to sympathomimetics. DM resulted in an increase in alpha-receptor-mediated contractions and a decrease in relaxation elicited by terbutaline on non-pregnant uterine rings. These changes could be partly explained by a higher myometrial level of PCR-product of alpha1B-receptor No DM-related change in uterine reactivity was described during pregnancy. Additionally, a more pronounced effect of oxytocin was evidenced in late pregnancy (days 15 and 21) which was diminished by term (day 22). Higher level of oxytocin receptors was detected from the uterine samples of diabetic animals. Presuming similar human regulatory mechanisms, it could be suggested that oxytocin antagonists are drugs of choice for the treatment of DM-elicited risk for premature delivery

Investigation of Anticancer Properties of Monoterpene-Aminopyrimidine Hybrids on A2780 Ovarian Cancer Cells

The present study aimed to characterize the antiproliferative and antimetastatic properties of two recently synthesized monoterpene-aminopyrimidine hybrids (1 and 2) on A2780 ovary cancer cells. Both agents exerted a more pronounced cell growth inhibitory action than the reference agent cisplatin, as determined by the MTT assay. Tumor selectivity was assessed using non-cancerous fibroblast cells. Hybrids 1 and 2 induced changes in cell morphology and membrane integrity in A2780 cells, as evidenced by Hoechst 33258–propidium iodide fluorescent staining. Cell cycle analysis by flow cytometry revealed substantial changes in the distribution of A2780 ovarian cancer cells, with an increased rate in the subG1 and G2/M phases, at the expense of the G1 cell population. Moreover, the tested molecules accelerated tubulin polymerization in a cell-free in vitro system. The antimetastatic properties of both tested compounds were investigated by wound healing and Boyden chamber assays after 24 and 48 h of incubation. Treatment with 1 and 2 resulted in time- and concentration-dependent inhibition of migration and invasion of A2780 cancer cells. These results support that the tested agents may be worth of further investigation as promising anticancer drug candidates

A Click Approach to Novel D-Ring-Substituted 16α-Triazolylestrone Derivatives and Characterization of Their Antiproliferative Properties

A simple and efficient synthesis of novel, D-ring substituted estrone derivatives containing a 16α-triazolyl moiety is described. Two epimeric azido alcohols (16α-azido-17α-hydroxy and 16α-azido-17β-hydroxy) of estra-1,3,5(10)-triene-3-methyl ether were prepared, followed by copper(I)-catalyzed azide-alkyne cycloaddition with various terminal alkynes. The steroidal triazoles were obtained in high yields and their activities against three human cancer cell lines (HeLa, MCF7 and A431) were screened. The most effective analogs were submitted to additional experiments in order to characterize their antiproliferative properties. As evidenced by flow cytometry, the selected steroids induced a disturbance in the HeLa cell cycle in a concentration- and exposure-dependent manner, through an increase of the hypodiploid population (subG1) and a cell cycle arrest in the G2/M phase. A noncancerous human fibroblast cell line (MRC5) was used to determine the selectivities of these compounds. Fluorescent microscopy after Hoechst 33258 - propidium iodide (HOPI) double staining revealed nuclear condensation and disturbed cell membrane integrity. The enhanced activities of caspase-3 and caspase-9 without activation of caspase-8 in the treated cells indicated the activation of the intrinsic pathway of apoptosis. The levels of cell cycle regulators (CDK1, cyclin B1/B2 and cdc25B) were decreased and the ratio Bax/Bcl-2 was increased 24 h after the treatment of HeLa cells (determined at an mRNA level by means of an RT-PCR technique). Under the same conditions, two agents elicited substantially increased degrees of phosphorylation of stathmin, as evidenced by Western blotting. The presented results demonstrate that these steroids can be regarded as appropriate structural scaffolds for the design and synthesis of further steroid analogs as innovative drug candidates with good efficacy.</p

Synthesis and Antiproliferative Activity of Steroidal Diaryl Ethers

Novel 13α-estrone derivatives have been synthesized via direct arylation of the phenolic hydroxy function. Chan–Lam couplings of arylboronic acids with 13α-estrone as a nucleophilic partner were carried out under copper catalysis. The antiproliferative activities of the newly synthesized diaryl ethers against a panel of human cancer cell lines (A2780, MCF-7, MDA-MB 231, HeLa, SiHa) were investigated by means of MTT assays. The quinoline derivative displayed substantial antiproliferative activity against MCF-7 and HeLa cell lines with low micromolar IC50 values. Disturbance of tubulin polymerization has been confirmed by microplate-based photometric assay. Computational calculations reveal significant interactions of the quinoline derivative with the taxoid binding site of tubulin

Investigation of Anticancer Properties of Monoterpene-Aminopyrimidine Hybrids on A2780 Ovarian Cancer Cells

The present study aimed to characterize the antiproliferative and antimetastatic properties of two recently synthesized monoterpene-aminopyrimidine hybrids (1 and 2) on A2780 ovary cancer cells. Both agents exerted a more pronounced cell growth inhibitory action than the reference agent cisplatin, as determined by the MTT assay. Tumor selectivity was assessed using non-cancerous fibroblast cells. Hybrids 1 and 2 induced changes in cell morphology and membrane integrity in A2780 cells, as evidenced by Hoechst 33258–propidium iodide fluorescent staining. Cell cycle analysis by flow cytometry revealed substantial changes in the distribution of A2780 ovarian cancer cells, with an increased rate in the subG1 and G2/M phases, at the expense of the G1 cell population. Moreover, the tested molecules accelerated tubulin polymerization in a cell-free in vitro system. The antimetastatic properties of both tested compounds were investigated by wound healing and Boyden chamber assays after 24 and 48 h of incubation. Treatment with 1 and 2 resulted in time- and concentration-dependent inhibition of migration and invasion of A2780 cancer cells. These results support that the tested agents may be worth of further investigation as promising anticancer drug candidates