Synthesis, anticancer activity and pharmacokinetic analysis of 1-[(substituted 2-alkoxyquinoxalin-3-yl)aminocarbonyl]-4-(hetero)arylpiperazine derivatives

Based on the anticancer activity of novel quinoxalinyl-piperazine compounds, 1-[(5 or 6-substituted alkoxyquinoxalinyl)aminocarbonyl]-4-(hetero)arylpiperazine derivatives published in Bioorg. Med. Chem.2010, 18, 7966, we further explored the synthesis of 7 or 8-substituted quinoxalinyl piperazine derivatives. From in vitro studies of the newly synthesized compounds using human cancer cell lines, we identified some of the 8-substituted compounds, for example 6p, 6q and 6r, which inhibited the proliferation of various human cancer cells at nanomolar concentrations. Compound 6r, in particular, showed the lowest IC(50) values, ranging from 6.1 to 17nM, in inhibition of the growth of cancer cells, which is better than compound 6k (compound 25 in the reference cited above). In order to select and develop a leading compound among the quinoxaline compounds with substitutions on positions 5, 6, 7 or 8, the compounds comparable to compound 6k in in vitro cancer cell growth inhibition were chosen and their pharmacokinetic properties were evaluated in rats. In these studies, compound 6k showed the highest oral bioavailability of 83.4%, and compounds 6j and 6q followed, with 77.8% and 57.6%, respectively. From the results of in vitro growth inhibitory activities and the pharmacokinetic study, compound 6k is suggested for further development as an orally deliverable anticancer drug.     

Synthesis, anticancer and antioxidant activities of some novel N-(benzo[d]oxazol-2-yl)-2-(7- or 5-substituted-2-oxoindolin-3-ylidene) hydrazinecarboxamide derivatives

A series of N-(benzo[d]oxazol-2-yl)-2-(7- or 5-substituted-2-oxoindolin-3-ylidene) hydrazinecarboxamide derivatives were synthesized by treating N-(benzoxazol-2-yl)hydrazinecarboxamide with different isatin derivatives. The newly synthesized compounds were characterized on the basis of spectral analyses. All the synthesized derivatives (Va-l) were screened for anticancer and antioxidant activities. The results showed the anticancer activity of test compounds against HeLa, IMR-32 and MCF-7 cancer cell lines using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. All the synthetic compounds produced a dose-dependant inhibition of growth of the cells. The IC(50) values of some compounds were comparable with standard anticancer agent, cisplatin. All the title compounds effectively scavenged the free radical, α,α-diphenyl-β-picryl hydrazyl. The test compounds having substitution with different halides (electron withdrawing groups) at C5 position showed more potent anticancer and antioxidant activities than those at C7 position. These results indicate that C5-substituted derivatives may be useful for developing antioxidant agents that play a protective role in many pathological conditions such as cancer, diabetes and so on.     

Synthesis,anticancer and antioxidant activities of some novel N-(benzo[d]oxazol-2-yl)-2-(7- or 5-substituted-2-oxoindolin-3-ylidene) hydrazinecarboxamide derivatives

A series of N-(benzo[d]oxazol-2-yl)-2-(7- or 5-substituted-2-oxoindolin-3-ylidene) hydrazinecarboxamide derivatives were synthesized by treating N-(benzoxazol-2-yl)hydrazinecarboxamide with different isatin derivatives. The newly synthesized compounds were characterized on the basis of spectral analyses. All the synthesized derivatives (Va-l) were screened for anticancer and antioxidant activities. The results showed the anticancer activity of test compounds against HeLa, IMR-32 and MCF-7 cancer cell lines using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. All the synthetic compounds produced a dose-dependant inhibition of growth of the cells. The IC₅₀ values of some compounds were comparable with standard anticancer agent, cisplatin. All the title compounds effectively scavenged the free radical, α,α-diphenyl-β-picryl hydrazyl. The test compounds having substitution with different halides (electron withdrawing groups) at C5 position showed more potent anticancer and antioxidant activities than those at C7 position. These results indicate that C5-substituted derivatives may be useful for developing antioxidant agents that play a protective role in many pathological conditions such as cancer, diabetes and so on.     

Synthesis and antitumoral activity of novel 3-(2-substituted-1,3,4-oxadiazol-5-yl) and 3-(5-substituted-1,2,4-triazol-3-yl) beta-carboline derivatives

Several novel 1-substituted-phenyl beta-carbolines bearing the 2-substituted-1,3,4-oxadiazol-5-yl and 5-substituted-1,2,4-triazol-3-yl groups at C-3 were synthesized and evaluated for their in vitro anticancer activity. The assay results pointed thirteen compounds with growth inhibition effect (GI(50)<100 microM) for all eight different types of human cancer cell lines tested. The beta-carbolines 7a and 7h, bearing the 3-(2-metylthio-1,3,4-oxadiazol-5-yl) group, displayed high selectivity and potent anticancer activity against ovarian cell line with GI(50) values lying in the nanomolar concentration range (GI(50)=10 nM for both compounds). The 1-(N,N-dimethylaminophenyl)-3-(5-thioxo-1,2,4-triazol-3-yl) beta-carboline (8g) was the most active compound, showing particular effectiveness on lung (GI(50)=0.06 microM), ovarian and renal cell lines. The potent anticancer activity presented for synthesized compounds 7a, 7h, and 8g, together with their easiness of synthesis, makes these compounds promising anticancer agents.     

Methylseleninic acid enhances paclitaxel efficacy for the treatment of triple-negative breast cancer

A major challenge in breast cancer therapy is the lack of an effective therapeutic option for a particularly aggressive subtype of breast cancer, triple-negative breast cancer. Here we provide the first preclinical evidence that a second-generation selenium compound, methylseleninic acid, significantly enhances the anticancer efficacy of paclitaxel in triple-negative breast cancer. Through combination-index value calculation, we demonstrated that methylseleninic acid synergistically enhanced the growth inhibitory effect of paclitaxel in triple-negative breast cancer cells. The synergism was attributable to more pronounced induction of caspase-mediated apoptosis, arrest of cell cycle progression at the G2/M checkpoint, and inhibition of cell proliferation. Treatment of SCID mice bearing MDA-MB-231 triple-negative breast cancer xenografts for four weeks with methylseleninic acid (4.5 mg/kg/day, orally) and paclitaxel (10 mg/kg/week, through intraperitoneal injection) resulted in a more pronounced inhibition of tumor growth compared with either agent alone. The attenuated tumor growth correlated with a decrease in tumor cell proliferation and an induction of apoptosis. The in vivo study also indicated the safety of using methylseleninic acid in the combination regime. Our findings thus provide strong justification for the further development of methylseleninic acid and paclitaxel combination therapy for the treatment of triple-negative breast cancer.     

Synthesis and antitumor activities of novel α-aminophosphonates dehydroabietic acid derivatives

A series of novel α-aminophosphonate derivatives containing DHA structure were designed and synthesized as antitumor agents. In vitro antitumor activities of these compounds against the NCI-H460 (human lung cancer cell), A549 (human lung adenocarcinoma cell), HepG2 (human liver cancer cell) and SKOV3 (human ovarian cancer cell) human cancer cell lines were evaluated and compared with commercial anticancer drug 5-fluorouracil (5-FU), employing standard MTT assay. The pharmacological screening results revealed that many compounds exhibited moderate to high levels of antitumor activities against the tested cancer cell lines and that most demonstrated more potent inhibitory activities compared with the commercial anticancer drug 5-FU. The action mechanism of representative compound 7c was preliminarily investigated by acridine orange/ethidium bromide staining, Hoechst 33258 staining, JC-1 mitochondrial membrane potential staining and flow cytometry, which indicated that the compound can induce cell apoptosis in NCI-H460 cells. Cell cycle analysis showed that compound 7c mainly arrested NCI-H460 cells in G1 stage.     

miR-17-5p Downregulation Contributes to Paclitaxel Resistance of Lung Cancer Cells through Altering Beclin1 Expression

Non- small- cell lung cancer (NSCLC) is one of the most leading causes of cancer-related deaths worldwide. Paclitaxel based combination therapies have long been used as a standard treatment in aggressive NSCLCs. But paclitaxel resistance has emerged as a major clinical problem in combating non-small-cell lung cancer and autophagy is one of the important mechanisms involved in this phenomenon. In this study, we used microRNA (miRNA) arrays to screen differentially expressed miRNAs between paclitaxel sensitive lung cancer cells A549 and its paclitaxel-resistant cell variant (A549-T24). We identified miR-17-5p was one of most significantly downregulated miRNAs in paclitaxel-resistant lung cancer cells compared to paclitaxel sensitive parental cells. We found that overexpression of miR-17-5p sensitized paclitaxel resistant lung cancer cells to paclitaxel induced apoptotic cell death. Moreover, in this report we demonstrated that miR-17-5p directly binds to the 3′-UTR of beclin 1 gene, one of the most important autophagy modulator. Overexpression of miR-17-5p into paclitaxel resistant lung cancer cells reduced beclin1 expression and a concordant decease in cellular autophagy. We also observed similar results in another paclitaxel resistant lung adenosquamous carcinoma cells (H596-TxR). Our results indicated that paclitaxel resistance of lung cancer is associated with downregulation of miR-17-5p expression which might cause upregulation of BECN1 expression.     

Anthraquinone derivatives induce G2/M cell cycle arrest and apoptosis in NTUB1 cells

Thirteen anthraquinone derivatives 5-17 including two 3-(3-alkylaminopropoxy)-9,10-anthraquinone (NHA) derivatives 5 and 6, and 11 1-hydroxy-3-(3-alkylaminopropoxy)-9,10-anthraquinone (MHA) derivatives 7-17 were synthesized, evaluated for cytotoxicities against two cancer cell lines, and assayed the generation of reactive oxygen species (ROS) in NTUB1 cells (a human bladder carcinoma cell line). Compound 9 bearing a pyrrolidinyl group induced the stronger cytotoxic effect than those of other synthesized NHA and MHA derivatives. Exposure of NTUB1 cells to 9, 13, and 17 for 24h significantly increased the production of ROS, respectively. Flow cytometric analysis exhibited that the exposure of NTUB1 cells to the selective 9 led to the G2/M phase arrest accompanied by an increase of apoptotic cell death after the incubation for 24h. Compound 9 induced up-regulation of cyclinB1 and p21 expressions. Biological results suggested that the induction of G2/M arrest, apoptosis, and cell death by 9 may associate with increased expression of p21 and cyclin B1, elevation of Bax and p53 levels, and generation of ROS in the cell. In conclusion, these series of compounds may be used as anticancer agents.     

Synthesis, biological evaluation and molecular docking studies of 3-(1,3-diphenyl-1H-pyrazol-4-yl)-N-phenylacrylamide derivatives as inhibitors of HDAC activity

In present study, a series of 3-(1,3-diphenyl-1H-pyrazol-4-yl)-N-phenylacrylamide derivatives (5a-8d) were designed, synthesized, and evaluated for HDAC inhibition and tumor cell antiproliferation. All of these compounds are reported for the first time, the chemical structures of these compounds were confirmed by means of (1)H NMR, ESI-MS and elemental analyzes. Among the compounds, compound 8c showed the most potent biological activity against HCT116 cancer cell line (IC(50) of 0.42 ± 0.02 μM for HDAC-1 and IC(50)=0.62 ± 0.02 for HCT116). Docking simulation was performed to position compound 8c into the HDAC active site to determine the probable binding model. The results of antiproliferative assay and western-blot demonstrated that compound 8c with potent inhibitory activity in tumor growth inhibition may be a potential anticancer agent against HCT116 cancer cell.     

Synthesis and in vitro anti-proliferative effects of 3-(hetero)aryl substituted 3-[(prop-2-ynyloxy)(thiophen-2-yl)methyl]pyridine derivatives on various cancer cell lines

A series of 3-(hetero)aryl substituted 3-[(prop-2-ynyloxy)(thiophen-2-yl)methyl]pyridine derivatives were designed as potential anticancer agents. These compounds were conveniently prepared by using Pd/C–Cu mediated Sonogashira type coupling as a key step. Many of these compounds were found to be promising when tested for their in vitro anti-proliferative properties against six cancer cell lines. All these compounds were found to be selective towards the growth inhibition of cancer cells with IC₅₀ values in the range of 0.9–1.7 μM (against MDA-MB 231 and MCF7 cells), comparable to the known anticancer drug doxorubicin.     

Design, synthesis and biological evaluation of N-phenylsulfonylnicotinamide derivatives as novel antitumor inhibitors

A series of novel N-phenylsulfonylnicotinamide derivatives (1-24) have been synthesized and evaluated as potential EGFR tyrosine kinase (TK) inhibitors. Among all the compounds, compound 10 (5-bromo-N-(4-chlorophenylsulfonyl)nicotinamide) showed the most potent growth inhibitory activity against EGFR TK and antiproliferative activity of MCF-7 cancer cell line in vitro, with IC(50) value of 0.09 and 0.07 μM. Docking simulation was performed to insert compound 10 into the EGFR TK active site to determine the probable binding model. Based on the preliminary results, compound 10 with potent inhibitory activity to tumor growth may be a potential anticancer agent.     

Design, synthesis, and preliminary biological evaluation of novel ethyl 1-(2'-hydroxy-3'-aroxypropyl)-3-aryl-1H-pyrazole-5-carboxylate

We synthesized a series of novel small molecules, ethyl 1-(2′-hydroxy-3′-aroxypropyl)-3-aryl-1H-pyrazole-5-carboxylate derivatives 3a–3o, by the reaction of ethyl 3-aryl-1H-pyrazole-5-carboxylate with 2-aryloxymethylepoxide in the presence of potassium carbonate at refluxing in acetonitrile in moderate or excellent yields. We investigated the effects of all the compounds on A549 cell growth. The results showed that 15 compounds could suppress A549 lung cancer cell growth. Among them, compound 3i was the most effective small molecule in inhibiting A549 cell growth. Compound 3f might most effectively induce A549 cell differentiation. Compound 3g remarkably induced cellular vacuolation.     

Synergistic effect of curcumin on epigallocatechin gallate-induced anticancer action in PC3 prostate cancer cells

Epigallocatechin gallate (EGCG) and curcumin are well known to naturally-occurring anticancer agents. The aim of this study was to verify the combined beneficial anticancer effects of curcumin and EGCG on PC3 prostate cancer cells, which are resistant to chemotherapy drugs and apoptosis inducers. EGCG showed weaker inhibitory effect on PC3 cell proliferation than two other prostate cancer cell lines, LNCaP and DU145. Co-treatment of curcumin improved antiproliferative effect of EGCG on PC3 cells. The protein expressions of p21 were significantly increased by the co-treatment of EGCG and curcumin, whereas it was not changed by the treatment with each individual compound. Moreover, treatments of EGCG and curcumin arrested both S and G2/M phases of PC3 cells. These results suggest that the enhanced inhibitory effect of EGCG on PC3 cell proliferation by curcumin was mediated by the synergic up-regulation of p21-induced growth arrest and followed cell growth arrest. [BMB Reports 2015; 48(8): 461-466]     

Synthesis of new conjugated coumarin–benzimidazole hybrids and their anticancer activity

A series of novel coumarin–benzimidazole hybrids, 3-(1H-benzo[d]imidazol-2-yl)-7-(substituted amino)-2H-chromen-2-one derivatives of biological interest were synthesized. Six out of the newly synthesized compounds were screened for in vitro antitumor activity against preliminary 60 tumor cell lines panel assay. A significant inhibition for cancer cells was observed with compound 8 (more than 50% inhibition) compared with other compounds and active known drug 5-fluorouracil (in some cell lines) as positive control. Compound 8 displayed appreciable anticancer activities against leukemia, colon cancer and breast cancer cell lines.     

Induction of Apoptosis in Hepatocellular Carcinoma Cell Lines by Novel Indolylacrylamide Derivatives: Synthesis and Biological Evaluation

Hepatocellular carcinoma (HCC) is the most prevalent primary liver cancer and one of the leading causes of cancer associated death worldwide. This is due to the highly resistant nature of this malignancy and the lack of effective treatment options for advanced stage HCC patients. The hyperactivity of PI3K/Akt and Ras/Raf/MEK/ERK signaling pathways contribute to the cancer progression, survival, motility, and resistance mechanisms, and the interaction of these two pathways are responsible for the regulation of cancer cell growth and development. Therefore, it is vital to design and develop novel therapeutic options for HCC treatment targeting these hyperactive pathways. For this purpose, novel series of trans-indole-3-ylacrylamide derivatives originated from the lead compound, 3-(1H-indole-3-yl)-N-(3,4,5-trimethoxyphenyl)acrylamide, have been synthesized and analyzed for their bioactivity on cancer cells along with the lead compound. Based on the initial screening, the most potent compounds were selected to elucidate their effects on cellular signaling activity of HCC cell lines. Cell cycle analysis, immunofluorescence, and Western blot analysis revealed that lead compound and (E)-N-(4-tert-butylphenyl)-3-(1H-indole-3-yl)acrylamide induced cell cycle arrest at the G2/M phase, enhanced chromatin condensation and PARP-cleavage, addressing induction of apoptotic cell death. Additionally, these compounds decreased the activity of ERK signaling pathway, where phosphorylated ERK1/2 and c-Jun protein levels diminished significantly. Relevant to these findings, the lead compound was able to inhibit tubulin polymerization as well. To conclude, the novel trans-indole-3-ylacrylamide derivatives inhibit one of the critical pathways associated with HCC which results in cell cycle arrest and apoptosis in HCC cell lines.     

Anticancer activity of 3-O-acyl and alkyl-(-)-epicatechin derivatives

By changing the structure or replacing the gallate group of (-)-ECG, 3-O-acyl and alkyl-(-)-epicatechin derivatives were synthesized to be screen as anticancer agents using the MTT assay in vitro against cancer cell lines (PC3, SKOV3, U373MG). 3-O-Acyl and alkyl-(-)-epicatechin derivatives (4-25) exhibited better anticancer activity than (-)-ECG and specially, compounds 6-8, 17-19, which were modified aliphatic chains with moderate sizes (C8-C12) showed strong anticancer activity (IC50=6.4-31.2 microM). The introduction of an alkyloxy group on 3-O-hydroxyl instead of an acyloxy group significantly enhanced inhibitory activity. Consequently, the compound that showed the most potency as anticancer agents were 3-O-decyl-(-)-epicatechin (18) (IC50=8.9, 7.9, 6.4 microM against PC3, SKOV3, U373MG, respectively), which modified the appropriate lipophilic group on the C-3 hydroxyl as an alkyloxy group.     

A New 2α,5α,10β,14β-tetraacetoxy-4(20),11-taxadiene (SIA) Derivative Overcomes Paclitaxel Resistance by Inhibiting MAPK Signaling and Increasing Paclitaxel Accumulation in Breast Cancer Cells

Tumor resistance due to multiple mechanisms seriously hinders the efficacy of chemotherapy drugs such as paclitaxel. The most widely studied P-glycoprotein inhibitors still have limited ability to reverse resistance in the clinic. In this study, NPB304, a novel Sinenxan A (SIA) derivative, was found to significantly sensitize resistant breast cancer cells to paclitaxel in vitro and in vivo. Treatment with NPB304 increased paclitaxel-induced apoptosis in a p53-dependent manner through PARP cleavage. Importantly, NPB304 enhanced the antitumor effect of paclitaxel in resistant breast tumor xenografts in nude mice without significantly affecting weight loss. NPB304 regulated cell resistance through inhibition of MAPK pathway components, including p-ERK and p-p38. Moreover, NPB304 increased paclitaxel accumulation by affecting P-gp function. In addition to increasing Rhodamine 123 accumulation, NPB304 promoted bidirectional permeability but decreased the efflux ratio of paclitaxel in a Caco-2 monolayer model, thereby increasing the intracellular concentration of paclitaxel. Similarly, NPB304 increased the concentration of paclitaxel in the resistant tumor tissue. Hence, NPB304 is a novel compound that promotes the sensitization of resistant cells to paclitaxel through multiple mechanisms and has the potential for use in combination therapies to treat resistant breast cancer.     

Synthesis and discovery of pyrazole-5-carbohydrazide N-glycosides as inducer of autophagy in A549 lung cancer cells

A series of novel 3-aryl-1-arylmethyl-1H-pyrazole-5-carbohydrazide N-β-glycoside derivatives was synthesized by the reaction of substituted 1H-pyrazole-5-carbohydrazide with d-sugar and the effects of all the compounds on A549 cell growth were investigated. The results showed that all compounds had inhibitory effects on the growth of A549 lung cancer cells and compound 3d possessed the highest growth inhibitory effect and induced autophagy of A549 lung cancer cells.