Lactandrate: a D-homo-aza-androsterone alkylator in the treatment of breast cancer

Secosteroid diacylhydrazines as novel effective agents against hormone-dependent breast cancer cells

This research aimed to develop novel selective secosteroids that are highly active against hormone-dependent breast cancer. A simple and convenient approach to N'-acylated 13,17-secoestra-1,3,5(10)-trien-17-oic acid hydrazides was disclosed and these novel types of secosteroids were screened for cytotoxicity against the hormone-dependent human breast cancer cell line MCF7. Most secosteroid N'-benzoyl hydrazides have demonstrated high cytotoxicity against MCF7 cells with IC50 values below 5 μM, which are superior to that of the reference drug cisplatin. Hit compounds 2c, 2e and 2i were characterized by high cytotoxicity (IC50 = 1.6-1.9 μM) and very good selectivity towards MCF7 breast cancer cells. The lead secosteroids 2c, 2e and 2i also exhibit antiestrogenic effects and alter the expression of cell cycle regulating proteins. The effect of selected compounds on PARP (poly(ADP-ribose) polymerase) and Bcl-2 (B-cell CLL/lymphoma 2) indicates their proapoptotic potential. The synthesized secosteroids may be considered as new promising anti-breast cancer agents targeting ERα and apoptosis pathways.

Cytocidal Antitumor Effects against Human Ovarian Cancer Cells Induced by B-Lactam Steroid Alkylators with Targeted Activity against Poly (ADP-Ribose) Polymerase (PARP) Enzymes in a Cell-Free Assay

We evaluated three newly synthesized B-lactam hybrid homo-aza-steroidal alkylators (ASA-A, ASA-B and ASA-C) for their PARP1/2 inhibition activity and their DNA damaging effect against human ovarian carcinoma cells. These agents are conjugated with an alkylating component (POPA), which also served as a reference molecule (positive control), and were tested against four human ovarian cell lines in vitro (UWB1.289 + BRCA1, UWB1.289, SKOV-3 and OVCAR-3). The studied compounds were thereafter compared to 3-AB, a known PARP inhibitor, as well as to Olaparib, a standard third-generation PARP inhibitor, on a PARP assay investigating their inhibitory potential. Finally, a PARP1 and PARP2 mRNA expression analysis by qRT-PCR was produced in order to measure the absolute and the relative gene expression (in mRNA transcripts) between treated and untreated cells. All the investigated hybrid steroid alkylators and POPA decreased in vitro cell growth differentially, according to the sensitivity and different gene characteristics of each cell line, while ASA-A and ASA-B presented the most significant anticancer activity. Both these compounds induced PARP1/2 enzyme inhibition, DNA damage (alkylation) and upregulation of PARP mRNA expression, for all tested cell lines. However, ASA-C underperformed on average in the above tasks, while the compound ASA-B induced synthetic lethality effects on the ovarian cancer cells. Nevertheless, the overall outcome, leading to a drug-like potential, provides strong evidence toward further evaluation.

Anticancer Activity of Triazolo-Thiadiazole Derivatives and Inhibition of AKT1 and AKT2 Activation

The fusion of 1,2,4-triazole and 1,3,4-thiadiazole rings results in a class of heterocycles compounds with an extensive range of pharmacological properties. A series of 1,2,4-triazolo[3,4-b]-1,2,4-thiadiazoles was synthesized and tested for its enzyme inhibition potential and anticancer activity. The results show that 1,2,4-triazolo[3,4-b]-1,2,4-thiadiazoles display potent anticancer properties in vitro against a panel of cancer cells and in vivo efficacy in HT-29 human colon tumor xenograft in CB17 severe combined immunodeficient (SCID) mice. Preliminary mechanistic studies revealed that KA25 and KA39 exhibit time- and concentration-dependent inhibition of Akt Ser-473 phosphorylation. Molecular modeling experiments indicated that 1,2,4-triazolo[3,4-b]-1,2,4-thiadiazoles bind well to the ATP binding site in Akt1 and Akt2. The low acute toxicity combined with in vitro and in vivo anticancer activity render triazolo[3,4-b]thiadiazoles KA25, KA26, and KA39 promising cancer therapeutic agents.

Azasteroid Alkylators as Dual Inhibitors of AKT and ERK Signaling for the Treatment of Ovarian Carcinoma

(1) Background: Previous findings show that lactam steroidal alkylating esters display improved therapeutic efficacy with reduced toxicity. The aim of this study was to evaluate the anticancer activity of two newly synthesized aza-steroid alkylators (ENGA-L06E and ENGA-L08E) against human ovarian carcinoma cells, and consequently, the dual inhibition of RAS/PI3K/AKT and RAS/RAF/MEK/ERK signaling pathways, both of which are closely associated with ovarian cancer; (2) Methods: The in vitro cytostatic and cytotoxic effects of ENGA-L06E and ENGA-L08E were evaluated in a panel of five human ovarian cancer cell lines, as well as in in vivo studies. ENGA-L06E and ENGA-L08E, in addition to another two aniline-mustard alkylators, POPAM and melphalan (L-PAM), were utilized in order to determine the acute toxicity and antitumor efficacy on two human ovarian xenograft models. Also, in silico studies were performed in order to investigate the dual inhibition of ENGA-L06E and ENGA-L08E on RAS/PI3K/AKT and RAS/RAF/MEK/ERK signaling pathways; (3) Results: Both, in vitro and in vivo studies demonstrated that ENGA-L06E and ENGA-L08E were significantly more effective with a lower toxicity profile in comparison to POPAM and L-PAM alkylators. Moreover, in silico studies demonstrated that the two new aza-steroid alkylators could act as efficient inhibitors of the phosphorylation of AKT and ERK1/2 molecules; and (4) Conclusions: Both ENGA-L06E and ENGA-L08E demonstrated high anticancer activity through the inhibition of the PI3K-AKT and KRAS-ERK signaling pathways against human ovarian carcinoma, and thus constituting strong evidence towards further clinical development.

Discovery of steroidal lactam conjugates of POPAM-NH2 with potent anticancer activity

Aim: Steroidal prodrugs of nitrogen mustards such as estramustine and prednimustine have proven effective anticancer agents in clinical use since the 1970s. In this work, we aimed to develop steroidal prodrugs of the novel nitrogen mustard POPAM-NH2. POPAM-NH2 is a melphalan analogue that was coupled with three different steroidal lactams. Methodology: The new conjugates were preclinically tested for anticancer activity against nine human and one rodent cancer experimental models, in vitro and in vivo. Results & conclusion: All the steroidal alkylators showed high antitumor activity, in vitro and in vivo, in the experimental systems tested. Moreover, these hybrid compounds showed by far superior anticancer activity compared with the alkylating agents, melphalan and POPAM-NH2.

Discovery and development of azasteroids as anticancer agents

Cancer is the second leading cause of death worldwide following cardiovascular diseases. Cancer can be treated by a variety of techniques including surgery, radiation therapy, immunotherapy, and chemotherapy. Choice of the method can be made based on type, physiologic location and the stage of disease progression. Among chemical methods, steroids find broad applications. Azasteroids have N- substitutions in steroidal rings. This structural modification renders azasteroids advantageous in increased effectiveness and reduced side effects. Numerous accounts of cancer efficacy of this family of compounds are available in literature. The progress made in the discovery, synthetic efforts and development of azasteroids as anticancer agents is broadly outlined in this review.

The Effect of Newly Synthesized Heterosteroids on miRNA34a, 98, and 214 Expression Levels in MCF-7 Breast Cancer Cells

Hybrid anticancer drugs have emerged as great therapeutic options that can effectively overcome most obstacles facing conventional anticancer drugs. miRNAs are considered as class of non-coding RNAs that can negatively regulate protein coding gene expression. miRNA expression is commonly altered in cancer cells. The current work aimed to test the effect of new pro-apoptotic heterosteroids on some drug resistance related miRNAs expression levels (miRNA34a, 98, and 214) in MCF-7 breast cancer cells. After cell treatment with these compounds 4, 6, 7, 13, 18, 21, 22 and 24, miRNAs were extracted and subjected to reverse transcription and subsequent PCR amplification using Real Time-PCR technique. The expression levels of miR-34a, miR-98 and miR-214 were quantitatively determined. The study revealed that the expression levels of miR-34a, miR-98 and miR-214 were up-regulated upon treatment with tamoxifen, which was used as a positive control drug, as compared to control cells,. Strikingly, the levels of miR-34a, miR-98 and miR-214 expression were significantly down-regulated when treated with most of the new heterosteroids as compared to control cells. These results could indicate the promising effects of these new heterosteroids on reducing drug resistance as compared to tamoxifen drug. As well established, cells develop drug resistance to tamoxifen.

Targeting on poly(ADP-ribose) polymerase activity with DNA-damaging hybrid lactam-steroid alkylators in wild-type and BRCA1-mutated ovarian cancer cells

Conjugated lactam-steroid alkylators (LSA) have been shown to exhibit superior activity at controlling cancer models and overlap drug resistance to conventional chemjournalapy. Hybrid LSA combine two active compounds in a single molecule and incorporate modified steroids bearing lactam moiety in one or more steroid rings functioning as vectors for cytotoxic agents. We first describe a novel class of LSA that generate excellent anticancer activity against UWB1.289 and UWB1.289 + BRCA1 human ovarian cancer cell lines. Both UWB1.289 and UWB1.289 + BRCA1 cells carry mutations in the tumor suppressor gene TP53 while UWB1.289 cell line carries a germline BRCA1 mutation. In vitro, in vivo, and in silico, experimental methods were utilized to determine the poly(ADP-ribose) polymerases (PARPs) activity and mRNA transcription, DNA damage, cytostatic and cytotoxic effects, and virtual molecular interactions, in order to study the molecular mechanisms of activity of the tested LSA. LSA produce anticancer activity through dual action by combining the direct induction of cellular DNA damage with the inhibition of PARP activity and consecutive DNA repair activity. BRCA1-mutated UWB1.289 ovarian cancer cells with defective PARP-oriented repair mechanism show significantly higher sensitivity to these agents. Combined drug effect on DNA damage and repair is a novel approach in cancer therapeutics.

Evaluation of heterocyclic steroids and curcumin derivatives as anti-breast cancer agents: Studying the effect on apoptosis in MCF-7 breast cancer cells

Anticancer agents consisting of hybrid molecules are used to improve effectiveness and diminish drug resistance. The current study aimed to introduce newly synthesized hetero-steroids of promising anticancer effects. Besides, the pro-apoptotic effects of new compounds were investigated extensively. Several pyrimidino-, triazolopyrimidino-, pyridazino-, and curcumin-steroid derivatives were synthesized, elucidated and confirmed using the spectral and analytical data. The synthesized hetero-steroids, compounds 9, 10, 11, 12, 13, 14, 15, 18, 20, 21, 22 and 24, were tested for their cytotoxic effects versus human breast cancer cells (MCF-7) using neutral red supravital dye uptake assay. Compound 24 (IC50=18μM) showed more inhibitory influence on MCF-7 growth. Using QRT-PCR (Quantitative real time-polymerase chain reaction), CCND1, Survivin, BCL-2, CDC2, P21 and P53, genes expression levels were investigated. The study results disclose that compounds 4, 7, 18, 24 knocked down the expression levels of CCND1, Survivin, BCL-2 and CDC2. However, P21 and P53 were up-regulated by compounds 21, 22. This study introduced promising pro-apoptotic anticancer agents acting through the modulation of key regulators of apoptosis and cell cycle genes.

Synthesis and evaluation of new steroidal lactam conjugates with aniline mustards as potential antileukemic therapeutics

Alkylating agents are still nowadays one of the most important classes of cytotoxic drugs, which display a wide range of therapeutic use for the treatment of various cancers. We have synthesized and tested four hybrid homo-azasteroidal alkylating esters for antileukemic activity against five sensitive to alkylating agents human leukemia cell lines in vitro and against P388 murine leukemia in vivo. Comparatively, melphalan and 3-(4-(bis(2-chloroethyl)amino)phenoxy)propanoic acid (POPAM) were also examined. All the homo-aza-steroidal alkylators showed relatively lower acute toxicity, very promising and antileukemic activity both in vitro and in vivo.

Quinazolinones-Phenylquinoxaline hybrids with unsaturation/saturation linkers as novel anti-proliferative agents

A new series of novel quinazolinones with allylphenyl quinoxaline hybrids 9a-n were efficiently synthesized in good yields by the reaction of 3-allyl-2-methylquinazolin-4(3H)-one (5a-n) with bromophenyl)quinoxaline (8) utilizing Pd catalyzed Heck-cross coupling and evaluated for anti-proliferative activity against four cancer cell lines such as HeLa (cervical), MIAPACA (pancreatic), MDA-MB-231 (breast) and IMR32 (neuroblastoma). Compounds 9a, 9e, 9g and 9h exhibited promising anti-proliferative activity with GI50 values ranging from 0.06 to 0.2μM against four cell lines, while compounds 9e and 9k showed significant activity against HeLa and MIAPACA cell lines and compounds 9b, 9d, 9h and 9j showed selective potency against IMR32 and MDA-MB-231 cell lines. This is the first report on the synthesis and in vitro anti-proliferative evaluation of E-2-(4-substituted)-3-(3-(4-(quinoxalin-2-yl)phenyl)allyl)quinazolin-4(3H)-ones (9a-n). Docking results indicate a sign of good correlation between experimental activity and calculated binding affinity (dock score), suggesting that these compounds could act as promising DNA intercalates.

Synthesis and antiproliferative evaluation of some novel B-nor-D-homosteroids

Using 3β-hydroxy-5-androsten-17-one as a starting material, a series of novel nitrogen-containing B-nor-D-homosteroids were designed and synthesized by the oximation, Beckman rearrangement, ozonation, cyclization and condensation reaction. The structures of all new compounds were determined by analysis of their NMR, MS and IR spectra. The antiproliferative activity of compounds was evaluated against HT-29 (colonic carcinoma), HeLa (human cervical carcinoma) and Bel 7404 (human liver carcinoma) cells.

Synthesis and anti-tumor evaluation of B-ring substituted steroidal pyrazoline derivatives

The synthesis and anti-tumor activity screening of new steroidal derivatives (4-18) containing pharmacologically attractive pyrazoline moieties are performed. During in vitro anticancer evaluation, the newly synthesized compounds displayed moderate to good cytotoxicity on cervical and leukemia cancer cell lines. In addition these compounds were found to be nontoxic to normal cell (PBMCs) (IC50>50 μM). The structure-activity relationship is also discussed. The most effective anticancer compound 9 was found to be active with IC50 value of 10.6 μM. It demonstrated significant antiproliferative influence on Jurkat cell lines. The morphological changes and growth characteristics of HeLa cells treated with compound 4 were analyzed by means of SEM.

Steroid-linked nitrogen mustards as potential anticancer therapeutics: a review

Nitrogen mustards, an important class of drugs for cancer therapy, are known as DNA alkylating agents. The nitrogen mustards are highly reactive and, as a consequence, lack of selectivity and produce several adverse side effects. In order to minimize these undesirable effects, the attachment of nitrogen mustards to a steroidal hormone with affinity for its receptor can lead to highly selective and less toxic antineoplastic therapeutics. This review will focus on the design, synthesis and evaluation of such steroid-nitrogen mustard hybrids as antineoplastic agents. Among these compounds, modified steroids with aromatic nitrogen mustards linked by an ester function were found to have better DNA alkylating properties, improved selectivity as well as low toxicity. This article is part of a Special Issue entitled "Synthesis and biological testing of steroid derivatives as inhibitors".

Synthesis and evaluation of some 17-acetamidoandrostane and N,N-dimethyl-7-deoxycholic amide derivatives as cytotoxic agents: structure/activity studies

Using pregnenolone and 7-deoxycholic acid as starting materials, some 17-acetamidoandrostane and N,N-dimethyl-7-deoxycholic amide derivatives were synthesized. The cytotoxicity of the synthesized compounds was tested in vitro against two tumor cell lines: SGC 7901 (human gastric carcinoma) and Bel 7404 (human liver carcinoma). The result showed that the blockage of the interaction of the amide group with outside groups might cause a decrease of the cytotoxicity, and an O-benzyloximino group at the 3-position of N,N-dimethyl-7-deoxycholic amide could enhance the cytotoxic activity of the compound. The information obtained from the studies provides the structure-activity relationship for these compounds and may be useful for the design of novel chemotherapeutic drugs.

6-hydroximino-4-aza-A-homo-cholest-3-one and related analogue as a potent inducer of apoptosis in cancer cells

Here we report that 6-hydroximino-4-aza-A-homo-cholest-3-one and 6-hydroxyl-4-aza-A-homo-cholest-3-one, new steroidal lactams were synthesized recently, displayed antiproliferative activity against some cancer cells through inducing cancer cell apoptosis by activation of the intrinsic pathway. The apoptotic function of the compounds was demonstrated by release of cytochrome C, activation of caspase 3 and annexin V labeling. Furthermore, the compound was able to inhibit tumor growth in an athymic mouse model.

Synthesis and antiproliferative activity of some steroidal lactams

Using cholesterol as starting material, a series of 6-substituted-3-aza-A-homo-3-oxycholestanes and 6-substituted-4-aza-A-homo-3-oxycholestanes were synthesized by the oxidation, reduction, oximation, Beckman rearrangement and condensation reaction. These synthesized compounds displayed a distinct cytotoxicity against MGC 7901, HeLa and SMMC 7404 cancer cells. Our results revealed that the structures of functional groups at position-6 on the steroidal ring are crucial for the IC(50) value of antiproliferative activities of these compounds and the cytotoxic activity against MGC 7901 and SMMC 7404 cells was not significantly different between 4-N-lactams and 3-N-lactams when its 6-substituted group was a carbonyl or a hydroximino, but all 3-N-lactams showed a higher cytotoxicity against HeLa cells than 4-N-lactams. In particular, compounds 6, 8, 9 (IC(50)6: 6.5 μmol/L; 8: 7.7 μmol/L; 9: 5.6 μmol/L) were even more cytotoxic than cisplatin to HeLa cells (positive contrast, 10.1 μmol/L). The information obtained from the studies may be useful for the design of novel chemotherapeutic drugs.

Synthesis and cytotoxicity of A-homo-lactam derivatives of cholic acid and 7-deoxycholic acid

Using cholic acid and deoxycholic acid as starting materials, a series of 3-aza-A-homo-4-one bile acid and 7-deoxycholic acid derivatives were synthesized by the esterification, oxidation, reduction, oximation and Beckman rearrangement etc. The cytotoxicity of the synthesized compounds against MGC 7901 (human ventriculi carcinoma cell line), hela (human cervical carcinoma cell line), SMMC 7404 (human liver carcinoma cell line) were investigated. The results showed that bile acid and 7-deoxycholic-acid derivatives with 3-aza-A-homo-4-one configuration bearing a 6-hydroximino or 12-hydroximino group displayed a distinct cytotoxicity to Hela tumor cell line. In particular, the IC(50) values of the compounds 6 and 13 were 14.3 and 24.3 μmol/L against Hela human tumor cell line respectively. The information obtained from the studies may be useful for the design of novel chemotherapeutic drugs.

Synthesis and cytotoxicity of 17a-aza-D-homo-androster-17-one derivatives

A series of 17a-aza-D-homo-andrester-17-one derivatives, bearing hydroxyl, hydroximino, carbonyl and thiosemicarbazido groups at the position-3 or position-6 of steroidal nucleus, were prepared and evaluated in vitro against two human cell lines (Hela (human cervical carcinoma) and SMMC 7404 (human liver carcinoma)). The results showed that these compounds could exhibit a high cytotoxicity to Hela tumor cell line, especially for compounds 8 and 12, the IC(50) values are 15.1 and 14.0 nmol/mL, respectively. Our findings could provide new evidence showing the relationship between the chemical structure and biological activity and may be useful for the discovery of new anti-cancer drugs.

Synthesis and biological evaluation of some nitrogen containing steroidal heterocycles

epi-Androsterone 1 was converted into its hydrazone derivative through the reaction with hydrazine hydrate 80%. Hydrazonoandrostane derivative 2b reacted with hydrazonoyl halides in the presence of K(2)CO(3) forming the corresponding hydrazopyridazinoandrostane derivatives 6a-d. The 3β-acetyl-17-hydrazonoandrostane derivative 2b reacted with a halogen reagent, benzoyl chloride, to form the non-cyclic 16-benzoylated hydrazone 9. On the other hand, compound 2b produced the corresponding pyridazinoandrostane derivatives 11 and 12 via its reaction with phenacyl bromide and chloroacetone respectively. Reaction of the hydrazono derivative 2b with benzaldehyde in the presence of acetic acid drops led to the formation of the benzylidenehydrazonoandrostane derivative 13. The product 14, phosphinom-ethylenehydrazonoandrostane was obtained by the reaction of the derivative 13 with trisdimethylaminophosphine in the presence of dry benzene. The reaction of compound 2b with phenyl isothiocyanate followed by boiling in chloroacetic acid or thioglycolic acid produced the pyrazoloandrostane derivatives 17 and 18 respectively. The biological activity of compounds 6a, 6d, 11, 12, and 15 was evaluated as inhibitor of growth in a human liver carcinoma cell line and doxorubicine was used for comparison. Compounds 15 and 12 showed a higher potency than the other tested compounds.