Design,Synthesis and In Vitro Activity of Anticancer Styrylquinolines. The p53 Independent Mechanism of Action

A group of styrylquinolines were synthesized and tested for their anti-proliferative activity. Anti-proliferative activity was evaluated against the human colon carcinoma cell lines that had a normal expression of the p53 protein (HCT116 p53^+/+) and mutants with a disabled TP53 gene (HCT116 p53^-/-) and against the GM 07492 normal human fibroblast cell line. A SAR study revealed the importance of Cl and OH as substituents in the styryl moiety. Several of the compounds that were tested were found to have a marked anti-proliferative activity that was similar to or better than doxorubicin and were more active against the p53 null than the wild type cells. The cellular localization tests and caspase activity assays suggest a mechanism of action through the mitochondrial pathway of apoptosis in a p53-independent manner. The activity of the styrylquinoline compounds may be associated with their DNA intercalating ability.     

Investigation of new acyloxy derivatives of cholic acid and their esters as drug absorption modifiers

Skin penetration enhancers are used in the formulation of transdermal delivery systems for drugs that are otherwise not sufficiently skin-permeable. Intestinal absorption promoters/enhancers are used as excipients in oral formulations of poorly oral-bioavailable drugs. Series of fourteen acyloxy derivatives of 5β-cholic acid as potential drug absorption modifiers was generated by multistep synthesis. The synthesis of all newly prepared compounds is presented here. Structure confirmation of all generated compounds was accomplished by (1)H NMR, (13)C NMR, IR and MS spectroscopy methods. All the prepared compounds were analyzed using RP-TLC, and their lipophilicity (R(M)) was determined. The hydrophobicity (logP) and solubility (logS) of the studied compounds were also calculated using two commercially available programs. All the target compounds were tested for their in vitro transdermal penetration activity and as potential intestinal absorption enhancers. The anti-proliferative activity of all the final compounds was also assessed against the human cancer cell lines: T-lymphoblastic leukemia cell line and the breast adenocarcinoma cell line. Their cytotoxicity was also evaluated against the normal human skin fibroblast cells. Two compounds showed anti-proliferative effect on cancer cells without affecting the growth of normal cells, which should be promising in potential development of new drugs. Most of the target compounds showed minimal anti-proliferative activity (IC(50)>37 μM), indicating they would have low cytotoxicity when administered as chemical absorption modifiers. The relationships between the lipophilicity and the chemical structure of the studied compounds as well as the relationships between their chemical structure and enhancement effects are discussed in this article.     

Design, synthesis and biological evaluation of novel quinazoline derivatives as potential anti-cancer agents

Twenty-two quinazoline derivatives have been synthesised and examined for their anti-tumour activity against three tumour cell lines, namely human breast cancer cell line (MCF-7), human cervical cancer cell line (HeLa) and human hepatoma cell line (HepG2). Twelve of the tested compounds have shown promising anti-tumour activity with an IC(50) range of 5.0-9.7 μg/mL. Regarding the spectrum of activity, five compounds exhibited interesting anti-proliferative properties against the three tested cell lines comparable to the reference drug (dasatinib).     

Design,synthesis and biological evaluation of novel quinazoline derivatives as potential anti-cancer agents

Twenty-two quinazoline derivatives have been synthesised and examined for their anti-tumour activity against three tumour cell lines, namely human breast cancer cell line (MCF-7), human cervical cancer cell line (HeLa) and human hepatoma cell line (HepG2). Twelve of the tested compounds have shown promising anti-tumour activity with an IC₅₀ range of 5.0–9.7 µg/mL. Regarding the spectrum of activity, five compounds exhibited interesting anti-proliferative properties against the three tested cell lines comparable to the reference drug (dasatinib).     

Semi-synthesis and anti-proliferative activity evaluation of novel analogues of Honokiol

A series of honokiol analogues were synthesized by modifying the 5- and/or 3′-position(s) of honokiol to assess their anti-tumor effects. Some compounds exerted more potent anti-proliferative activities than those of honokiol on K562 leukemia cells, A549 alveolar basal epithelial cells, SPC-A1 adenocarcinoma cells and A2780 human ovarian carcinoma cells in vitro. Compounds 2b, 3a, and 3c displayed most potent anti-proliferative activities against these tested cell strains and their anti-drug resistance effects were evaluated in vitro on cisplatin-resistant A2780 human ovarian carcinoma cells. The structure–activity relationship was also proposed.     

Design,synthesis, docking studies and biological evaluation of novel chalcone derivatives as potential histone deacetylase inhibitors

A group of novel chalcone derivatives comprising hydroxamic acid or 2-aminobenzamide group as zinc binding groups (ZBG) were synthesized. The structure of the prepared compounds was fully characterized by IR, NMR and elemental microanalyses. Most of the tested compounds displayed strong to moderate HDAC inhibitory activity. Some of these compounds showed potent anti-proliferative activity against human HepG2, MCF-7 and HCT-116 cell lines. In particular, compounds 4a and 4b exhibited significant anti-proliferative activity against the three cell lines compared to SAHA as reference drug and displayed promising profile as anti-tumor candidates. The results indicated that these chalcone derivatives could serve as a promising lead compounds for further optimization as antitumor agents.     

Carbonic anhydrase inhibition with a series of novel benzenesulfonamide-triazole conjugates

We report the synthesis and characterisation of a novel series of triazole benzenesulfonamide derivatives, which incorporate the general pharmacophore associated with carbonic anhydrase (CA, EC 4.2.1.1) inhibitors. The synthesised compounds were tested in vitro against four human carbonic anhydrase (hCA, EC 4.2.1.1) isozymes, hCA I, hCA II, hCA IV and hCA IX. The obtained results showed that the tumour-associated hCA IX was the most sensitive to inhibition with the synthesised derivatives, with the triazolo-pyridine benzenesulfonamides 14, 16 and 17 being the most effective inhibitors. Some selected compounds were chosen for a single dose anti-proliferative activity testing against a panel of 57 human tumour cell lines and show some anti-proliferative activity ex vivo.     

Cytotoxic small molecule dimers and their inhibitory activity against human breast cancer cells

Small molecules based upon natural product dimers that exhibit cytotoxic activity were synthesized and evaluated for their anti-proliferative activity in human breast cancer cell lines. A central isophthalic core structure linking aromatic amines containing 3,5-disubstitutions produced the most active compounds. This series of compounds was found to be more active against the estrogen receptor positive cell line MCF-7 than the estrogen receptor negative cell line, SKBr3.     

Synthesis of novel isoflavene–propranolol hybrids as anti-tumor agents

Isoflavene–propranolol hybrid molecules were developed as potentially novel anti-tumour agents. Isoflavene itself has potent anti-cancer activity while propranolol can enhance anti-proliferative and anti-angiogenic properties of 5-fluorouracil and paclitaxel. The hybrids were produced via nucleophilic addition of substituted amine groups to a dioxiran intermediate, which was in turn generated from the Williamson-type reaction of isoflavene with (±)-epichlorohydrin. These analogues were tested in anti-cancer cell viability assays against SHEP neuroblastoma and MDA-MB-231 breast adenocarcinoma cell lines, and were found to exhibit potent anti-proliferative activities. These compounds also displayed anti-angiogenic and anti-proliferative effects in HMEC-1 human microvascular endothelial cell lines. Notably, the most potent hybrid molecules synthesized in this work showed enhanced potency against cancer cell lines compared to either isoflavene or propranolol alone, while retaining significant selectivity for cancer cells over MRC-5 normal lung fibroblast cells.     

Utilization of tetrahydrobenzo[4,5]thieno[2,3-d]pyrimidinone as a cap moiety in design of novel histone deacetylase inhibitors

A series of novel 5,6,7,8-Tetrahydro[1]benzothieno[2,3-d]pyrimidin-4(3H)-one derivatives bearing a hydroxamic acid, 2-aminoanilide and hydrazide moieties as zinc-binding group (ZBG) were designed, synthesized and evaluated for the HDAC inhibition activity and antiproliferative activity. Most of the tested compounds displayed strong to moderate HDAC inhibitory activity. Some of these compounds showed potent anti-proliferative activity against human HepG2, MCF-7 and HCT-116 cell lines. In particular, compounds IVa, IVb, IXa and IXb exhibited significant anti-proliferative activity against the three cell lines tested compared to SAHA as a reference. Compound IVb is equipotent inhibitor for HDAC1 and HDAC2 as SAHA. It is evident that the presence of free hydroxamic acid group is essential for Zn binding affinity with maximal activity with a linker of aliphatic 6 carbons. Docking study results revealed that compound IVb could occupy the HDAC2 binding site and had the potential to exhibit antitumor activity through HDAC inhibition, which merits further investigation.     

Design and synthesis of a new generation of substituted purine hydroxamate analogs as histone deacetylase inhibitors

Histone deacetylase inhibitors have been proved to be great potential for the treatment of cancer. Recently, we designed and modified a series of substituted purine hydroxamate analogs as potent HDAC inhibitors based on our previous studies. The target compounds were investigated for their in vitro HDAC inhibitory activities and anti-proliferative activities. Results indicated that these compounds could effectively inhibit HDAC and possess obvious anti-proliferative activity against tumor cells. Promisingly, target compounds 4m and 4n outperformed SAHA in both enzymatic inhibitory activity and cellular anti-proliferative activity assay.     

Inhibition of human breast cancer cell proliferation with estradiol metabolites is as effective as with tamoxifen.

The anti-estrogenic substance tamoxifen is effective in the adjuvant therapy applied in human breast cancer. Since it partly exhibits estrogenic activity and has serious side-effects, however, pure anti-estrogenic compounds are being sought. In our experimental study, we compared the anti-proliferative effect of estradiol and 13 endogenous estradiol metabolites on human breast cancer cells with the effect of tamoxifen. We used MCF-7 and MDA-MB 231, the well-established estrogen receptor-positive and -negative cell lines. 4-hydroxytamoxifen, the active metabolite of tamoxifen, estradiol and 13 estradiol metabolites were tested in concentrations ranging from 3.1 to 100 microM. Incubation time was 4 days and cell proliferation was measured by means of the ATP chemosensitivity test. 4-hydroxytamoxifen showed an IC50 value of 27 microM and 18 microM in MCF-7 and MDA-MB 231 cells, respectively. Estradiol and its metabolites were anti-proliferative in both cell lines. A few A-ring metabolites were more effective in inhibiting cell proliferation than D-ring metabolites and the parent substance 17beta-estradiol. 4-OHE1, 2-MeOE1 and 2-MeOE2 were as effective in both cell lines as tamoxifen. For the first time it has been demonstrated that endogenous estradiol metabolites are equally anti-proliferative as tamoxifen in the context of human breast cancer cells. Since some of these metabolites exhibit no estrogenic activity, they are likely to be valuable in clinical studies of chemoprevention and adjuvant therapy of breast cancer.     

Synthesis and evaluation of cytotoxicity of 6-amino-4-aryl-2-thioxo-1,2,3,4-tetrahydropyrimidine-5-carbonitriles

Several derivatives of 6-amino-4-aryl-2-thioxo-1,2,3,4-tetrahydropyrimidine-5-carbonitriles were synthesized via Biginelli type reaction and tested for their anti-proliferative activity on human breast cancer (MCF-7) and human colon carcinoma (HT29) cell lines. Malignant and non-malignant cells were cultivated in RPMI medium and incubated with different concentrations of these pyrimidines. Cell viability was evaluated by MTT assay. Apoptotic cells were determined using DAPI (4'-6-diamidino-2-phenylindole) and propidium iodide staining of DNA fragmentation by flow cytometry (sub-G1 peak). 6-Amino-4-(4-chlorophenyl)-2-thioxo-1,2,3,4-tetrahydropyrimidine-5-carbonitrile and 6-amino-4-[4-dimethylamino)phenyl]-2-thioxo-1,2,3,4-tetrahydropyrimidine-5-carbonitrile decreased the viability of MCF-7 and HT29 cells, in contrast to L929 cells. These compounds induced a sub-G1 peak inflow cytometry histograms of treated cells indicating that apoptosis is involved in their toxicity.     

N⁶-Alkyladenosines: Synthesis and evaluation of in vitro anticancer activity

A series of adenosine analogues differently substituted in N⁶-position were synthesized to continue our studies on the relationships between structure and biological activity of iPA. The structures of the compounds were confirmed by standard studies of ¹H NMR, MS and elemental analysis. These molecules were then evaluated for their anti-proliferative activity on bladder cancer cells. We found that some of these compounds possess anti-proliferative activity but have no effect on cell invasion and metalloprotease activity.     

Synthesis and biological evaluation of novel N, N'-disubstituted urea and thiourea derivatives as potential anti-melanoma agents

Two series of urea and thiourea derivatives (1a-11a, 1b-11b) have been synthesized; all the 22 compounds were reported for the first time. Their anti-proliferative activities against the melanoma cell line B16-F10 were evaluated. Among the compounds tested, compound 6b exhibited the most potent activity in melanoma cells growth inhibition (IC(50) = 0.33 μM). The bioassay tests showed that anti-proliferative activities of these novel compounds were possibly caused by inhibition of ERK1/2 phosphorylation level. Therefore, compound 6b can be a potential anti-melanoma agent and an inhibitor of ERK1/2 phosphorylation deserving further research.     

Anti-proliferative effect of chalcone derivatives through inactivation of NF-κB in human cancer cells

To investigate the anti-proliferative effect of NF-κB inhibitor, a series of analogs of (E)-1-(2-hydroxy-6-(isopentyloxy)phenyl)-3-(4-hydroxyphenyl)prop-2-en-1-one (5a) were prepared and evaluated for their NF-κB inhibition and anti-proliferative activity against various human cancer cell lines. Compounds (E)-1-(2-(3,3-dimethylbutoxy)-6-hydroxyphenyl)-3-(4-hydroxyphenyl)prop-2-en-1-one (5e) and (E)-4-(3-(2-(3,3-dimethylbutoxy)-6-hydroxyphenyl)-3-oxoprop-1-enyl)benzenesulfonamide (5p) showed good NF-κB inhibition as well as potent anti-proliferative activity. SAR studies showed that all the compounds with potent or moderate NF-κB inhibition displayed good anti-proliferative activity. All the analogs (5b–r) maintained a good correlation between their NF-κB inhibition and anti-proliferative activity though the extent is not directly proportional to each other.     

Design,synthesis and biological evaluation of lapachol derivatives possessing indole scaffolds as topoisomerase I inhibitors

A series of novel lapachol derivatives possessing indole scaffolds was designed and synthesized. The in vitro anti-proliferative activity of these novel compounds was evaluated in Eca109 and Hela cell lines. Almost all the tested compounds showed manifested potent inhibitory activity against the two tested cancer cell lines. Topo I-mediated DNA relaxation activity indicated that these novel compounds have potent Topoisomerase I inhibition activity. The most potent compounds 4n and 4k demonstrated more cytotoxicity than camptothecin and was comparable to camptothecin in inhibitory activities on Topoisomerase I in our biological assay. In addition, the Hoechst 33342 staining method also showed that the complex can induce Hela cell apoptosis.     

A novel piperazine linked β-amino alcohols bearing a benzosuberone scaffolds as anti-proliferative agents

A new series of 1-((9-chloro-2,3-dimethyl-6,7-dihydro-5H-benzo[7]annulen-8-yl)methoxy)-3-(4-phenylpiperzin-1-yl) propan-2-ols (6a-k) have been designed, synthesized and their structures were established by spectroscopic data (FT-IR, ¹H NMR, ¹³C NMR, HRMS) and further confirmed by X-ray analysis. The newly synthesized compounds 6a-k were evaluated for their in vitro anti-proliferative activity against four cancer cell lines such as HeLa (cervical), MDA-MB-231 (breast), A549 (lung) and MIAPACA (pancreatic). Among the compounds tested, the compound 6e displayed most potent activity against four cancer cell lines with GI₅₀ values ranging from 0.010 to 0.097 μM. The structure and anti-proliferative activity relationship was further supported by in silico molecular docking study of the active compounds against Colchicine binding site of β-tubulin.     

Recycling antimalarial leads for cancer: Antiproliferative properties of N-cinnamoyl chloroquine analogues

Cinnamic acids and quinolines are known as useful scaffolds in the discovery of antitumor agents. Therefore, N-cinnamoylated analogues of chloroquine, recently reported as potent dual-action antimalarials, were evaluated against three different cancer cell lines: MKN-28, Caco-2, and MCF-7. All compounds display anti-proliferative activity in the micromolar range against the three cell lines tested, and most of them were more active than their parent drug, chloroquine, against all cell lines tested. Hence, N-cinnamoyl-chloroquine analogues are a good start towards development of affordable antitumor leads.