Multi-target Anticancer Agents Research Articles

Structure–Activity Relationships of Targeted RuII(η6-p-Cymene) Anticancer Complexes with Flavonol-Derived Ligands

RuII(arene) complexes have been shown to be promising anticancer agents, capable of overcoming major drawbacks of currently used chemotherapeutics. We have synthesized RuII(η6-arene) compounds carrying bioactive flavonol ligands with the aim to obtain multitargeted anticancer agents. To validate this concept, studies on the mode of action of the complexes were conducted which indicated that they form covalent bonds to DNA, have only minor impact on the cell cycle, but inhibit CDK2 and topoisomerase IIα in vitro. The cytotoxic activity was determined in human cancer cell lines, resulting in very low IC50 values as compared to other RuII(arene) complexes and showing a structure-activity relationship dependent on the substitution pattern of the flavonol ligand. Furthermore, the inhibition of cell growth correlates well with the topoisomerase inhibitory activity. Compared to the flavonol ligands, the RuII(η6-p-cymene) complexes are more potent antiproliferative agents, which can be explained by potential multitargeted properties.

Co-treatment of THP-1 cells with naringenin and curcumin induces cell cycle arrest and apoptosis via numerous pathways.

Acute myeloid leukemia (AML) is a hematological malignancy with a low survival rate. Curcumin, which is a multi-targeted anticancer agent, has been shown to exert anti‑oxidant, anti‑inflammatory, anti‑mutagenic and anti‑carcinogenic activities. Naringenin is extracted from citrus fruits and exerts anti‑mutagenic and anti‑carcinogenic activities in various types of cancer cells. However, the effects of curcumin and naringenin in combination in AML cells have yet to be studied. The present study aimed to investigate the combination effects of curcumin and naringenin on the viability, cell cycle distribution and apoptosis rate of THP‑1 cells using cell viability assays, flow cytometry, and western blotting. Naringenin enhanced curcumin‑induced apoptosis and cell viability inhibition. In addition, curcumin and naringenin induced cell cycle arrest at S phase and G2/M phase. Numerous pathways, including p53, c‑Jun N‑terminal kinases (JNK), Akt and extracellular signal‑regulated kinases (ERK)1/2 pathways were markedly altered following treatment of THP‑1 cells with curcumin and naringenin. These results indicated that naringenin may enhance curcumin‑induced apoptosis through inhibiting the Akt and ERK pathways, and promoting the JNK and p53 pathways.

Synthesis of 2-[11C]methoxy-3,17β-O,O-bis(sulfamoyl)estradiol as a new potential PET agent for imaging of steroid sulfatase (STS) in cancers

Steroid sulfatase (STS) catalyzes the hydrolysis of steroid sulfates to estrones, the main source of estrogens in tumors. Carbonic anhydrase II (CAII) is highly expressed in red blood cells through a coordination of the monoanionic form of the sulfamate moiety to the zinc atom in the enzyme active site, and CAII is highly expressed in several tumors. 2-Methoxy-3,17β-O,O-bis(sulfamoyl)estradiol (5) is a dual-function STS-CAII inhibitor inhibited STS with 39nM IC50 value selectively over CAII with 379nM IC50 value. This compound exhibited potent antiproferative activity with mean graph midpoint value of 87nM in the NCI 60-cell-line panel, and antiangiogenic in vitro and in vivo activity in an early-stage Lewis lung model as well. The compound has been recently developed as a multitargeted anticancer agent. Both STS and CAII are over-expressed in cancers and have become attractive targets for cancer treatment and molecular imaging of cancer. Here we report the first design and synthesis of 2-[11C]methoxy-3,17β-O,O-bis(sulfamoyl)estradiol ([11C]5) as a new potential imaging agent for biomedical imaging technique positron emission tomography (PET) to image STS in cancers. The authentic standard 5 was synthesized from 17β-estradiol by published procedures in 5 steps with 40% overall chemical yield. The precursor 2-hydroxy-3,17β-O,O-bis(sulfamoyl)estradiol (14a) for radiolabeling was synthesized from 17β-estradiol in 10 steps with 5% overall chemical yield. The target tracer [11C]5 was prepared from the precursor 14a with [11C]CH3OTf through O-[11C]methylation and isolated by HPLC combined with solid-phase extraction (SPE) purification in 40–50% radiochemical yields based on [11C]CO2 and decay corrected to end of bombardment (EOB), with 370–740GBq/μmol specific activity at EOB.

Curaxins: A New Family of Non‐genotoxic Multitargeted Anticancer Agents

Curaxins: A New Family of Non‐genotoxic Multitargeted Anticancer Agents

Heart Failure Associated with Sunitinib: Lessons Learned from Animal Models

Sunitinib is a highly potent, multitargeted anticancer agent. However, there is growing clinical evidence that sunitinib induces cardiac dysfunction. Disruption of multiple signaling pathways, which are important in the maintenance of adult cardiac function, is likely to result in cardiovascular toxicity. Basic and translational evidence implicates a potential role for specific growth factor signaling pathways. This review discusses the relevant translational data from animal models of heart failure, focusing on three key pathways that are inhibited by sunitinib: AMP-activated protein kinase (AMPK), platelet-derived growth factor receptors (PDGFRs), and the vascular endothelial growth factor receptors (VEGFRs) 1, 2, and 3. We hypothesize that disruption of these pathways by sunitinib results in cardiotoxicity, and present direct and indirect evidence to support the notion that sunitinib-induced cardiac dysfunction likely involves a variety of molecular mechanisms that are critical for cardiac homeostasis.

Abstract 2619: Potential advantages of CUDC-101, a multi-targeted HDAC, EGFR and HER2 inhibitor, on preventing drug resistance and tumor metastasis

Abstract CUDC-101 is a novel small-molecule multi-target anti-cancer agent currently in Phase Ib clinical trial, which targets histone deacetylase (HDAC), epidermal growth factor receptor (EGFR) and human epidermal growth factor receptor2 (HER2). Previously, we reported that CUDC-101 has potent anti-proliferative and pro-apoptotic activities in cultured tumor cells and in vitro xenograft models when compared to other single-target agents. Additionally, we demonstrated that CUDC-101 reduces the levels of phosphorylated and total MET. MET amplification and secondary EGFR mutation are two validated mechanisms responsible for EGFR tyrosine kinase inhibitor (TKI) drug resistance in patients. In an effort to expand on our previous findings, we further substantiate here that cancer cells harboring MET amplification are sensitive to CUDC-101. This result, together with the finding that cancer cells containing the EGFR-T790M mutation are sensitive to CUDC-101, suggests that RTK inhibitor-resistant tumor cells are sensitive to treatment with CUDC-101. Additionally, erlotinib-resistant HCC827 cells, which lost their EGFR dependence, are still sensitive to treatment with CUDC-101. Interestingly, this drug-resistant cell line shows neither secondary EGFR mutation nor c-Met amplification, suggesting that CUDC-101 has the potential to overcome drug resistance through other mechanisms. Because c-Met plays an important role in metastasis, we further investigated the effect of CUDC-101 in regulating cell motility, and demonstrate that CUDC-101 can induce E-cadherin accumulation in MDA-MB-231 cells and inhibit EGF induced epithelial-mesenchymal transition (EMT) in in vitro cultured cell and in vivo animal models. In vitro functional study also shows that CUDC-101 reduces tumor cell migration and invasion. Together, our findings suggest that CUDC-101, an investigational anti-cancer drug, may provide great potential for simultaneously overcoming tumor growth, metastasis, and drug resistance. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 2619. doi:10.1158/1538-7445.AM2011-2619

Phase II study of motesanib in Japanese patients with advanced gastrointestinal stromal tumors with prior exposure to imatinib mesylate

PurposeMotesanib (AMG 706) is a multitargeted anticancer agent with an inhibitory action on the human vascular endothelial growth factor receptor, the platelet-derived growth factor receptor, and the cellular stem-cell factor receptor (KIT). The aim of this single-arm phase II clinical study was to assess the efficacy and safety of single-agent motesanib in Japanese patients with advanced gastrointestinal stromal tumors with prior exposure to imatinib mesylate.MethodsAll patients had experienced progression or relapse while undergoing with imatinib as 400 mg/day or higher. The patients were administered 125 mg of motesanib once daily. The primary endpoint was overall response. Efficacy was evaluated according to the Response Evaluation Criteria in Solid Tumor, and safety was assessed according to the Common Terminology Criteria for Adverse Events (version 3).ResultsOf 35 enrolled and treated patients, no patient showed a complete response, and one patient showed a partial response (PR). Seven had stable disease (SD) for at least 24 months, two of whom continued to have SD for more than 2 years. The median progression-free survival time was 16.1 weeks. Motesanib was well tolerated; commonly reported treatment-related adverse events were hypertension, diarrhea, and fatigue. Anemia was the only hematological toxicity that was reported.ConclusionsOne patient showed PR, and seven patients showed SD more than 24 weeks. Motesanib was found to be safe and well tolerated. The observed toxicities were consistent with Phase I study findings.

Novel tetra-acridine derivatives as dual inhibitors of topoisomerase II and the human proteasome

Acridine derivatives, such as amsacrine, represent a well known class of multi-targeted anti-cancer agents that generally interfere with DNA synthesis and inhibit topoisomerase II. But in addition, these tricyclic molecules often display secondary effects on other biochemical pathways including protein metabolism. In order to identify novel anti-cancer drugs, we evaluated the mechanism of action of a novel series of bis- and tetra-acridines. As expected, these molecules were found to interact with DNA and inhibit the topoisomerase II-mediated DNA decatenation. Interestingly when tested on human tumour cells either sensitive (HL-60) or resistant (HL-60/MX2) to topoisomerase II inhibitors, these molecules proved equicytotoxic against the two cell lines, suggesting that they do not only rely on topoisomerase II inhibition to exert their cytotoxic effects. In order to identify alternative targets, we tested the capacity of acridines 1– 9 to inhibit the proteasome machinery. Four tetra-acridines inhibited the proteasome in vitro, with IC 50 values up to 40 times lower than that of the reference proteasome inhibitor lactacystin. Moreover, unlike peptide aldehydes used as reference inhibitors for the proteasome, these new acridine compounds demonstrated a good selectivity towards the proteasome, when tested against four unrelated proteases. A cellular assay based on the degradation of a proteasome protein substrate indicated that at least two of the tetra-acridines maintained this proteasome inhibition activity in a cellular context. This is the first report of tetra-acridines that demonstrate dual topoisomerase II and proteasome inhibition properties. This new dual activity could represent a novel anti-cancer approach to circumvent certain forms of tumour resistance.

2-Substituted Estradiol Bis-sulfamates, Multitargeted Antitumor Agents: Synthesis, In Vitro SAR, Protein Crystallography, and In Vivo Activity

The anticancer activities and SARs of estradiol-17-O-sulfamates and estradiol 3,17-O,O-bis-sulfamates (E2bisMATEs) as steroid sulfatase (STS) inhibitors and antiproliferative agents are discussed. Estradiol 3,17-O,O-bis-sulfamates 20 and 21, in contrast to the 17-O-monosulfamate 11, proved to be excellent STS inhibitors. 2-Substituted E2bisMATEs 21 and 23 additionally exhibited potent antiproliferative activity with mean graph midpoint values of 18-87 nM in the NCI 60-cell-line panel. 21 Exhibited antiangiogenic in vitro and in vivo activity in an early-stage Lewis lung model, and 23 dosed p.o. caused marked growth inhibition in a nude mouse xenograft tumor model. Modeling studies suggest that the E2bisMATEs and 2-MeOE2 share a common mode of binding to tubulin, though COMPARE analysis of activity profiles was negative. 21 was cocrystallized with carbonic anhydrase II, and X-ray crystallography revealed unexpected coordination of the 17-O-sulfamate of 21 to the active site zinc and a probable additional lower affinity binding site. 2-Substituted E2bisMATEs are attractive candidates for further development as multitargeted anticancer agents.