fosbretabulin and Lung-Neoplasms

Lung cancer is the leading cause of cancer-related mortality in Germany. Improvements in our understanding of cancer biology have led to the development of novel agents that inhibit the tumour vasculature in order to induce subsequent tumour cell death. In this context, the inhibition of tumour-related angiogenesis - the growth of new vessels from pre-existing vessels - has become an attractive target for anticancer therapy. Bevacizumab, a monoclonal antibody against vascular endothelial growth factor (VEGF), has already been approved in combination with platinum-based chemotherapy in patients with advanced non-small cell lung cancer (NSCLC) without predominant squamous cell histology. Moreover, small molecule inhibitors targeting multiple angiogenic receptors have also shown promise when combined with standard chemotherapy. As a different approach, vascular disrupting agents (VDAs) have been designed to particularly target preexisting blood vessels which may lead to a vascular shut-down. In the present review, both principles of action and current clinical data on anti-angiogenic agents and VDAs in the treatment of patients with NSCLC are reviewed.

Topics: Angiogenesis Inhibitors; Antineoplastic Agents, Phytogenic; Antineoplastic Combined Chemotherapy Protocols; Carcinoma, Non-Small-Cell Lung; Cell Death; Drug Approval; Drug Delivery Systems; Humans; Lung Neoplasms; Stilbenes

Targeting vasculature, essential in oxygen and nutrient supply, represents a new frontier in the treatment of cancer. Apart from angiogenesis inhibitors that compromise the formation of new blood vessels, a second class of vascular disrupting agents (VDAs) targets endothelial cells and pericytes of the already established tumor vasculature, resulting in tumor ischemia and necrosis. VDAs have been divided into two types: ligand-directed VDAs and small molecules. Ligand-directed VDAs consist of targeting and effector moieties that are linked together. Their clinical efficacy appears limited because of cost and a lack of specificity and toxicity. Small molecules include two classes: the synthetic flavonoids, which work through induction of local cytokine production, and the tubulin-binding agents. The aim of this review is to discuss the hypothesized molecular mechanisms of action of VDAs and their early preclinical and clinical results, emphasizing ASA404, combretastatin A-4 disodium phosphate, ABT-751, and NPI-2358, reported in the treatment of non-small cell lung cancer, which is the leading cause of cancer death worldwide, and also to discuss future developments in this cancer population.

Topics: Animals; Antineoplastic Agents; Carcinoma, Non-Small-Cell Lung; Clinical Trials as Topic; Diketopiperazines; Endothelial Cells; Humans; Imidazoles; Lung Neoplasms; Pericytes; Piperazines; Stilbenes; Sulfonamides; Xanthones

The vascular disrupting agent combretastatin-A4-phosphate (CA4P) demonstrated antitumour activity in preclinical studies when combined with radiation.. Patients with non-small-cell lung cancer (NSCLC), prostate adenocarcinoma, and squamous cell carcinoma of the head and neck (SCCHN) received 27 Gy in 6 fractions treating twice weekly over 3 weeks, 55 Gy in 20 fractions over 4 weeks, and 66 Gy in 33 fractions over 6 weeks respectively. CA4P was escalated from 50 mg/m2 to 63 mg/m2. CA4P exposure was further increased from one to three to six doses. Patients with SCCHN received cetuximab in addition.. Thirty-nine patients received 121 doses of CA4P. Dose-limiting toxic effects (DLTs) of reversible ataxia and oculomotor nerve palsy occurred in two patients with prostate cancer receiving weekly CA4P at 63 mg/m2. DLT of cardiac ischaemia occurred in two patients with SCCHN at a weekly dose of 50 mg/m2 in combination with cetuximab. Three patients developed grade 3 hypertension. Responses were seen in 7 of 18 patients with NSCLC. At 3 years, 3 of 18 patients with prostate cancer had prostate-specific antigen relapse.. Radiotherapy with CA4P appears well tolerated in most patients. The combination of CA4P, cetuximab, and radiotherapy needs further scrutiny before it can be recommended for clinical studies.

Topics: Adenocarcinoma; Aged; Aged, 80 and over; Antineoplastic Agents, Phytogenic; Carcinoma, Non-Small-Cell Lung; Carcinoma, Squamous Cell; Chemoradiotherapy; Dose-Response Relationship, Drug; Female; Head and Neck Neoplasms; Humans; Lung Neoplasms; Male; Middle Aged; Prostatic Neoplasms; Squamous Cell Carcinoma of Head and Neck; Stilbenes

The vascular disrupting agent combretastatin A4 phosphate (CA4P) causes major regression of animal tumours when given as combination therapy.. Patients with advanced cancer refractory to standard therapy were treated with CA4P as a 10-min infusion, 20 h before carboplatin, paclitaxel, or paclitaxel, followed by carboplatin.. Combretastatin A4 phosphate was escalated from 36 to 54 mg m(-2) with the carboplatin area under the concentration curve (AUC) 4-5, from 27 to 54 mg m(-2) with paclitaxel 135-175 mg m(-2), and from 54 to 72 mg m(-2) with carboplatin AUC 5 and paclitaxel 175 mg m(-2). Grade 3 or 4 neutropenia was seen in 17%, and thrombocytopenia only in 4% of 46 patients. Grade 1-3 hypertension (26% of patients) and grade 1-3 tumour pain (65% of patients) were the most typical non-haematological toxicities. Dose-limiting toxicity of grade 3 hypertension or grade 3 ataxia was seen in two patients at 72 mg m(-2). Responses were seen in 10 of 46 (22%) patients with ovarian, oesophageal, small-cell lung cancer, and melanoma.. The combination of CA4P with carboplatin and paclitaxel was well tolerated in the majority of patients with adequate premedication and had antitumour activity in patients who were heavily pretreated.

Topics: Adult; Aged; Antineoplastic Combined Chemotherapy Protocols; Ataxia; Carboplatin; Carcinoma, Small Cell; Dose-Response Relationship, Drug; Esophageal Neoplasms; Female; Humans; Infusions, Intravenous; Life Expectancy; Lung Neoplasms; Male; Melanoma; Middle Aged; Neoplasms; Ovarian Neoplasms; Paclitaxel; Patient Selection; Stilbenes

Radiofrequency ablation (RFA) is a technology that uses radiofrequency thermal effect to induce coagulation necrosis of tumor tissue under the guidance of imaging. However, distant metastasis of tumor cells caused by tumor angiogenesis can lead to incomplete tumor clearing. In this study, LLC1 cell line was used for the construction of subcutaneous xenografts. Either 10 mg/kg or 20 mg/kg Fosbretabulin disodium (FBTD) was intragastrically administered every 2 days for a week. RFA was performed at the end of medication. The proportion of T cells was examined by flow cytometry. Serum IgG and IgA levels of mice were examined by ELISA. Expression of certain genes was estimated by qRT-PCR assay. In this study, we demonstrated that FBTD was able to significantly enhance RFA-induced immune function in tumor-bearing mice by upregulating RFA-induced CD8+ killer T cells. Consistently, 10 mg/kg or 20 mg/kg FBTD therapy upregulated the percentage of IFNγ+ and TNFα+ CD8+ tumor infiltrating lymphocytes in tumor-bearing mice compared to the RFA alone or FBTD alone group. Mechanistically, we reported that FBTD inhibited the RFA-induced PD-1 and PD-L1 upregulation in vivo. In conclusion, we demonstrated that FBTD promoted the antitumor effects of RFA in lung tumor-bearing mice in this study.

Topics: Animals; Catheter Ablation; Humans; Lung Neoplasms; Mice; Radiofrequency Ablation; Stilbenes

Topics: Antineoplastic Agents; Apoptosis; Cell Line, Tumor; Cell Proliferation; Drug Screening Assays, Antitumor; Humans; Lung Neoplasms; Matrix Metalloproteinases; Tubulin; Tubulin Modulators

Topics: Apoptosis; Cell Cycle Checkpoints; Cell Proliferation; Cyclic Nucleotide Phosphodiesterases, Type 4; Dose-Response Relationship, Drug; Drug Discovery; Drug Screening Assays, Antitumor; Glioma; Humans; Lung Neoplasms; Molecular Structure; Oxazoles; Phosphodiesterase 4 Inhibitors; Structure-Activity Relationship; Tubulin; Tubulin Modulators; Tumor Cells, Cultured

Tumor angiogenesis has been proven to potentiate tumor growth and metastasis; therefore, the strategies targeting tumor-related angiogenesis have great potentials in antitumor therapy.. Here, the GA&Gal dual-ligand-modified liposomes co-loaded with curcumin and combretastatin A-4 phosphate (CUCA/GA&Gal-Lip) were prepared and characterized. A novel "BEL-7402+HUVEC" co-cultured cell model was established to mimic tumor microenvironment. The cytotoxicity and migration assays were performed against the novel co-cultured model. Angiogenesis ability was evaluated by tube formation test, and in vivo metastatic ability was evaluated by lung metastasis test.. The result demonstrated that dual-ligand-modified liposomes showed greater inhibition of tumor angiogenesis and metastasis in comparison with other combined groups. Significantly, the mechanism analysis revealed that curcumin and combretastatin A-4 phosphate could inhibit tumor angiogenesis and metastasis via down-regulation of VEGF and VEGFR2 expression, respectively, and that GA&Gal-Lip could improve antitumor effect by GA/Gal-mediated active-targeting delivery.. CUCA/GA&Gal-Lip hold great potentials in hepatoma-targeting delivery of antitumor drugs and can achieve anti-angiogenic and anti-metastatic effects by simultaneously blocking VEGF/VEGFR2 signal pathway, therefore exhibiting superior anti-hepatoma efficacy.

Topics: Angiogenesis Inhibitors; Animals; Antineoplastic Agents, Phytogenic; Carcinoma, Hepatocellular; Cell Line, Tumor; Curcumin; Drug Liberation; Gene Expression Regulation, Neoplastic; Human Umbilical Vein Endothelial Cells; Humans; Ligands; Liposomes; Liver Neoplasms; Lung Neoplasms; Mice, Inbred BALB C; Neovascularization, Pathologic; Stilbenes; Xenograft Model Antitumor Assays

A series of 16 conjugates of the tubulin polymerization inhibitor combretastatin A4 (CA-4) and other functionally related stilbene with four 18-carbon fatty acids, namely, stearic, oleic, linoleic, and linolenic acids, have been synthesized in good yields. These new derivatives have been evaluated against the KB-3-1 (human epidermoid carcinoma), NCI-H460 (human lung cancer), HEK293 (human embryonic kidney), and MCF-7 (human breast adenocarcinoma) cell lines for antiproliferative activity, with the exhibited cytotoxic activities comparable with those of CA-4 and colchicine. Compounds

Topics: Antineoplastic Agents; Breast Neoplasms; Cell Line, Tumor; Cell Proliferation; Colchicine; Fatty Acids; HEK293 Cells; Humans; Lung Neoplasms; Molecular Structure; Stilbenes; Tubulin Modulators

Tubulin isotypes are known to regulate microtubule dynamic instability and contribute to the development of drug resistance in certain types of cancers. Combretastatin-A4 (CA-4) has a potent anti-mitotic, vascular disrupting and anti-angiogenic activity. It binds at the interface of αβ tubulin heterodimers and inhibits microtubules assembly. Interestingly, the CA-4 resistant human lung carcinoma shows alteration of βI and βIII isotype levels, a higher expression of βI tubulin isotype and a decreased expression of βIII tubulin isotypes has been reported in drug resistant cell lines. However, the origin of CA-4 resistance in lung carcinoma is not well understood. Here, we investigate the interaction and binding affinities of αβI, αβIIb, αβIII and αβIVa tubulin isotypes with CA-4, employing molecular modeling approaches. Sequence analysis shows that variations in residue composition at the CA-4 binding pocket of βI, βIII and βIVa tubulin isotypes when compared to template βIIb isotype. Molecular docking result shows that the CA-4 prefers 'cis' conformation in all αβ-tubulin isotypes. Molecular dynamics simulation reveal role of H7 helix, T7 loop and H8 helix of β-tubulin in lower binding affinity of αβI and αβIII isotypes for CA-4. The order of binding energy for CA-4 is αβIIb > αβIVa > αβI > αβIII. This suggest that drug resistance is induced in human lung carcinoma cells by altering the expression of β-tubulin isotypes namely βI and βIII which show lowest binding affinities. Our present study can help in designing potential CA-4 analogs against drug-resistant cancer cells showing altered expression of tubulin isotypes. Abbreviations:CA-4combretastatin-A4MDmolecular dynamicsRMSDroot mean square deviationDSSPdictionary of secondary structure of proteinsVMDvisual molecular dynamics Communicated by Ramaswamy H. Sarma.

Topics: Amino Acid Sequence; Drug Resistance, Neoplasm; Humans; Hydrogen Bonding; Lung Neoplasms; Models, Molecular; Molecular Docking Simulation; Molecular Dynamics Simulation; Protein Binding; Protein Multimerization; Protein Structure, Secondary; Sequence Homology, Amino Acid; Stilbenes; Thermodynamics; Tubulin

Noninvasive imaging of cell necrosis can provide an early evaluation of tumor response to treatments. Here, we aimed to design and synthesize a novel diindole-based magnetic resonance imaging (MRI) contrast agent (Gd-bis-DOTA-diindolylmethane, Gd-DIM) for assessment of tumor response to therapy at an early stage.. The oil-water partition coefficient (Log P) and relaxivity of Gd-DIM were determined in vitro. Then, its necrosis avidity was examined in necrotic cells in vitro and in rat models with microwave ablation-induced muscle necrosis (MAMN) and ischemia reperfusion-induced liver necrosis (IRLN) by MRI. Visualization of tumor necrosis induced by combretastatin A-4 disodium phosphate (CA4P) was evaluated in rats bearing W256 orthotopic liver tumor by MRI. Finally, DNA binding assay was performed to explore the possible necrosis-avidity mechanism of Gd-DIM.. The Log P value and T1 relaxivity of Gd-DIM is - 2.15 ± 0.01 and 6.61 mM. Gd-DIM may serve as a promising necrosis-avid MRI contrast agent for early assessment of tumor response to therapy.

Topics: Animals; Antineoplastic Agents, Phytogenic; Cell Line, Tumor; Contrast Media; Disease Models, Animal; Liver Neoplasms; Lung Neoplasms; Magnetic Resonance Imaging; Male; Necrosis; Rats; Rats, Sprague-Dawley; Stilbenes

Inhibition of tumor growth and metastasis simultaneously is an important issue for tumor therapy. The CXCR4/CXCL12 axis plays a crucial role in cancer metastasis, and the blocking of the CXCR4/CXCL12 axis is an effective way of inhibiting cancer metastasis. Combretastatin A4 nanodrug (CA4-NPs), a neogenesis blood vascular disrupting agent, can accumulate around blood vessels and disrupt tumor neogenesis of blood vessels more efficaciously than typical small molecular drug combretastatin A4 phosphate (CA4P). However, in this work, we find that the CXCR4 expression is significantly enhanced in CA4-NPs-treated tumor tissues in a metastatic orthotopic 4T1 mammary adenocarcinoma mouse model. Considering that the overexpression of CXCR4 can promote tumor cell metastasis, a novel cooperative strategy that utilizes plerixafor (PLF, CXCR4 antagonist) with CA4-NPs for inhibiting tumor growth and metastasis simultaneously is developed. The combination of CA4-NPs (60 mg kg

Topics: Animals; Antineoplastic Combined Chemotherapy Protocols; Benzylamines; Breast Neoplasms; Cell Proliferation; Cell Survival; Cyclams; Female; Gene Expression Regulation, Neoplastic; Heterocyclic Compounds; Humans; Lung Neoplasms; Mice; Receptors, CXCR4; Stilbenes; Theranostic Nanomedicine; Up-Regulation; Xenograft Model Antitumor Assays

Use of solid phase microextraction (SPME) for cell culture metabolomic analysis allows for the attainment of more sophisticated data from in vitro cell cultures. Moreover, considering that SPME allows the implementation of multiple extractions from the same sample due to its non/low-depletive nature, time course studies using the same set of samples are thus facilitated via this method. Such an approach results in a reduction in the number of samples needed for analysis thus eliminates inter-batch variability related to biological variation occurring during cell culturing. The current work aims to demonstrate the capability of SPME for measurements of combretastatin A4 (CA4) effectiveness on non-small cell cancer cell line. A cultivation protocol was established in the 96-well plate, and a fiber format of SPME was selected for metabolite extraction. The extracellular metabolic pattern of cells was changed after administration of the tested drug. This suggests pharmacological activity of the administered compound towards the studied cell line model. Results support that the use of direct immersion SPME for analysis of cell cultures does not affect cells growth or contaminate sample. Consequently, SPME allows the attainment of accurate information regarding drug uptake, metabolism, and metabolomic changes in the studied cells induced by exposure to the drug simultaneously in a single experiment.

Topics: A549 Cells; Carcinoma, Non-Small-Cell Lung; Humans; Lung Neoplasms; Metabolomics; Solid Phase Extraction; Stilbenes

Hypoxic tumor niches are chief causes of treatment resistance and tumor recurrence. Sickle erythrocytes' (SSRBCs') intrinsic oxygen-sensing functionality empowers them to access such hypoxic niches wherein they form microaggregates that induce focal vessel closure. In search of measures to augment the scale of SSRBC-mediated tumor vaso-occlusion, we turned to the vascular disrupting agent, combretastatin A-4 (CA-4). CA-4 induces selective tumor endothelial injury, blood stasis, and hypoxia but fails to eliminate peripheral tumor foci. In this article, we show that introducing deoxygenated SSRBCs into tumor microvessels treated with CA-4 and sublethal radiation (SR) produces a massive surge of tumor vaso-occlusion and broadly propagated tumor infarctions that engulfs treatment-resistant hypoxic niches and eradicates established lung tumors. Tumor regression was histologically corroborated by significant treatment effect. Treated tumors displayed disseminated microvessels occluded by tightly packed SSRBCs along with widely distributed pimidazole-positive hypoxic tumor cells. Humanized HbS-knockin mice (SSKI) but not HbA-knockin mice (AAKI) showed a similar treatment response underscoring SSRBCs as the paramount tumoricidal effectors. Thus, CA-4-SR-remodeled tumor vessels license SSRBCs to produce an unprecedented surge of tumor vaso-occlusion and infarction that envelops treatment-resistant tumor niches resulting in complete tumor regression. Strategically deployed, these innovative tools constitute a major conceptual advance with compelling translational potential.

Topics: Anemia, Sickle Cell; Animals; Antineoplastic Agents, Phytogenic; Cell Adhesion; Cell Hypoxia; Cell Line, Tumor; Combined Modality Therapy; Erythrocytes, Abnormal; Female; Gene Knock-In Techniques; Hemoglobin, Sickle; Humans; Lung; Lung Neoplasms; Male; Mice; Mice, Transgenic; Microvessels; Neoplasm Recurrence, Local; Stilbenes; Transplantation, Heterologous; Tumor Burden; Xenograft Model Antitumor Assays

Antivascular therapy is a promising approach to the treatment of non-small cell lung cancer (NSCLC), where an imaging modality capable of longitudinally monitoring treatment response could provide early prediction of the outcome. In this study, we sought to investigate the feasibility of using intravoxel incoherent motion (IVIM) diffusion MRI to quantitatively assess the efficacy of the treatments of a vascular-disrupting agent CA4P or its combination with bevacizumab on experimental NSCLC tumors. CA4P caused a strong but reversible effect on tumor vasculature; all perfusion-related parameters-D*, f, fD*, and K

Topics: A549 Cells; Angiogenesis Inhibitors; Animals; Antineoplastic Combined Chemotherapy Protocols; Bevacizumab; Carcinoma, Non-Small-Cell Lung; Diffusion Magnetic Resonance Imaging; Humans; Lung Neoplasms; Male; Mice; Mice, Inbred BALB C; Motion; Random Allocation; Stilbenes; Xenograft Model Antitumor Assays

Amino acid prodrugs are known to be very useful for improving the aqueous solubility of sparingly water soluble drugs (Drug Discovery Today 2013, 18, 93). Therefore, we synthesized eleven novel combretastatin A-4 amino acid derivatives and evaluated their anti-tumor activities in vitro and in vivo. Among them, compound 15 (valine attached to compound 3, which was shown to be a potent tubulin polymerization inhibitor in our previous study) exhibited high efficacy in tumor-bearing mice, and pharmacokinetic analysis in rats indicated that compound 15 was an effective prodrug as well. Besides, compound 15 significantly inhibited tubulin polymerization in vitro and in vivo by binding to the colchicine binding site. In addition, compound 15 induced cell cycle arrest in the G2/M phase and triggered apoptosis in a caspase-dependent manner. In conclusion, our study showed that compound 15 could have significant anti-tumor activity as a novel microtubule polymerization disrupting agent with improved aqueous solubility.

Topics: Amino Acids; Animals; Antineoplastic Agents; Cell Cycle Checkpoints; Drug Design; Female; Humans; Lung Neoplasms; Mice; Mice, Nude; Microtubules; Neoplasms, Experimental; Ovarian Neoplasms; Prodrugs; Rats; Stilbenes

Microtubules are critical elements that are involved in a wide range of cellular processes, and thus, they have become an attractive target for many anticancer drugs. A novel synthesised compound, 12P, was identified as new microtubule inhibitor. This compound inhibits tubulin polymerisation through binding to the colchicine-binding site of tubulin. 12P exhibits excellent anti-proliferative activities against a panel of human cancer cell lines, with IC₅₀ values range from 9 to 55nM. Interestingly, compound 12P also displayed equally potent cytotoxicity against several drug-resistant cell lines, and it showed high selectivity for active human umbilical vein endothelial cells (HUVECs). Further flow cytometric analysis showed that 12P induces G₂/M phase arrest and apoptosis in A549 cells. Cellular studies have revealed that the induction of apoptosis by 12P was associated with a collapse of mitochondrial membrane potential (MMP), accumulation of reactive oxygen species (ROS), alterations in the expression of some cell cycle-related proteins (e.g. Cyclin B1, Cdc25c, Cdc2) and some apoptosis-related proteins (e.g. Bax, Bad, Bcl-2, Bcl-xl). Importantly, 12P significantly reduced the growth of xenograft tumours of A549 cells in vivo (tumour inhibitory rate of 12P: 84.2%), without any loss of body weight. Taken together, these in vitro and in vivo results suggested that 12P may become a promising lead compound for the development of new anticancer drugs.

Topics: Animals; Antineoplastic Agents; Apoptosis; Benzodiazepinones; Carcinoma, Non-Small-Cell Lung; Cell Line, Tumor; Cell Proliferation; Cells, Cultured; Drug Resistance, Neoplasm; Drugs, Investigational; Human Umbilical Vein Endothelial Cells; Humans; Lung Neoplasms; Male; Mice, Inbred BALB C; Mice, Nude; Microtubules; Molecular Docking Simulation; Organophosphates; Random Allocation; Stilbenes; Tubulin; Tubulin Modulators; Xenograft Model Antitumor Assays

Lung cancer is the leading cause of cancer-related death. About 80% of lung cancers are non-small cell lung cancers (NSCLC). Radiotherapy is widely used in treatment of NSCLC. However, the outcome of NSCLC remains unsatisfactory. In this study, a vascular disrupting agent (VDA) combretastatin-A4-phosphate (CA4P) was used to provide massive necrosis targets. (131)I labeled necrosis-avid agent protohypericin ((131)I-prohy) was explored for therapy of NSCLC using tumor necrosis targeted radiotherapy (TNTR). Gamma counting, autoradiography, fluorescence microscopy and histopathology were used for biodistribution analysis. Magnetic resonance imaging (MRI) was used to monitor tumor volume, ratios of necrosis and tumor doubling time (DT). The biodistribution data revealed 131I-prohy was delivered efficiently to tumors. Tracer uptake peaked at 24 h in necrotic tumor of (131)I-prohy with and without combined CA4P (3.87 ± 0.38 and 2.96 ± 0.34%ID/g). (131)I-prohy + CA4P enhanced the uptake of (131)I-prohy in necrotic tumor compared to (131)I-prohy alone. The TNTR combined with CA4P prolonged survival of tumor bearing mice relative to vehicle control group, CA4P control group and (131)I-prohy control group with median survival of 35, 20, 22 and 27 days respectively. In conclusion, TNTR appeared to be effective for the treatment of NSCLC.

Topics: Animals; Antineoplastic Agents; Autoradiography; Carcinoma, Non-Small-Cell Lung; Cell Line, Tumor; Cell Proliferation; Chemoradiotherapy; Disease Models, Animal; Humans; Iodine Radioisotopes; Lung Neoplasms; Magnetic Resonance Imaging; Male; Mice, Inbred BALB C; Mice, Nude; Necrosis; Perylene; Radiography; Radiopharmaceuticals; Stilbenes; Tissue Distribution; Tumor Burden; Xenograft Model Antitumor Assays

The vasculature in tumor microenvironment plays important roles in the tumor growth and metastasis, and the combination of vascular disrupting agents with chemotherapeutic drugs should be effective in inhibiting tumor progression. But the dosing schedules are essential to achieve a balance between vascular collapse and intratumoral uptake of chemotherapeutic agents. In the current study, emulsion and blend electrospinning were used to create compartmental fibers accommodating both combretastatin A-4 (CA4) and hydroxycamptothecin (HCPT). The release durations of CA4 and HCPT were modulated through the structure of fibers for dual drug loadings and the inoculation of 2-hydroxypropyl-β-cyclodextrin in fiber matrices. Under a noncontact cell coculture in Transwell, the sequential release of CA4 and HCPT indicated a sequential killing of endothelial and tumor cells. In an orthotopic breast tumor model, all the CA4/HCPT-loaded fibers showed superior antitumor efficacy and higher survival rate than fibers with loaded individual drug. Compared with fibrous mats with infiltrated free CA4 and fibers with extended release of CA4 for over 30 days, fibers with sustained release of CA4 for 3-7 days from CA4/HCPT-loaded fibers resulted in the most significant antitumor efficacy, tumor vasculature destruction, and the least tumor metastasis to lungs. A judicious selection of CA4 release durations in the combination therapy should be essential to enhance the tumor suppression efficacy and antimetastasis activity.

Topics: 2-Hydroxypropyl-beta-cyclodextrin; Angiogenesis Inhibitors; Animals; Antineoplastic Agents; Antineoplastic Agents, Phytogenic; beta-Cyclodextrins; Breast Neoplasms; Camptothecin; Drug Carriers; Drug Liberation; Female; Lactates; Lung Neoplasms; Mice; Mice, Inbred BALB C; Polyethylene Glycols; Stilbenes

Combretastatin A-4 (CA-4) is a tubulin-binding compound currently in phase II trial as a tumor vascular-targeting agent. The present study evaluates the anti-tumor activities and establishes the mechanism of the action of 4-(4-methoxyphenyl)-5-(3,4,5-trimethoxyphenyl)-1H-pyrazol-3-amine(XN0502), a novel synthesized CA-4 analogue, in an effort towards finding the favorable therapeutics of CA-4 derivatives. XN0502 is characterized by its more potent anti-proliferative activities against non-small cell lung cancer A549 cells (IC(50): 1.8 +/- 0.6 microM), than that on the normal human liver HL-7702 cells (IC(50): 9.1 +/- 0.4 microM). Of note, using tubulin polymerization assay, western blot and immuofluorescence analyses, XN0502 was showed to inhibit microtubule assembly at both molecular and cellular levels in A549 cells. Further studies indicated that XN0502 induced time- and dose-dependent G2/M arrest, accompanying with the reduction of CDC2/p34 expression and the downregulation of CDK7. The protein level alteration and the nuclear translocation of cyclinB1 were observed, denoting the M phase arrest in XN0502-treated cells. Moreover, XN0502 caused caspase-mediated apoptosis, as indicated by the cleavage of PARP, the reduction of procaspase-3 and procaspase-9, and the down-regulation of XIAP. Taken together, the current study demonstrates that the novel CA-4 analogue XN0502 is a promising anti-cancer agent with potent G2/M arrest- and apoptotic-inducing activities via targeting tubulin deserving further research and development, and helps provide data for exploiting new CA-4 analogues.

Topics: Anisoles; Antineoplastic Agents, Phytogenic; Apoptosis; Carcinoma, Non-Small-Cell Lung; Caspases; Cell Cycle; Cell Line; Cell Line, Tumor; Cell Proliferation; Cyclin-Dependent Kinase-Activating Kinase; Cyclin-Dependent Kinases; Drug Screening Assays, Antitumor; Humans; Lung Neoplasms; Pyrazoles; Signal Transduction; Stilbenes; Tubulin Modulators

The relationship between microtubular dynamics, dismantling of pericentriolar components and induction of apoptosis was analysed after exposure of H460 non-small lung cancer cells to anti-mitotic drugs. The microtubule destabilising agent, combretastatin-A4 (CA-4) led to microtubular array disorganization, arrest in mitosis and abnormal metaphases, accompanied by the presence of numerous centrosome-independent "star-like" structures containing tubulin and aggregates of pericentrosomal matrix components like gamma-tubulin, pericentrin and ninein, whereas the structural integrity of centrioles was not affected by treatment. On the contrary, in condition of prolonged exposure or high concentrations of CA-4 such aggregates never formed. Treatment with 7.5 nM CA-4, which produced a high frequency "star-like" aggregates, was accompanied by mitotic catastrophe commitment characterized by translocation of the proapoptotic Bim protein to mitochondria activation of caspases-3/9 and DNA fragmentation as a result of either prolonged metaphase arrest or attempt of cells to divide. Drug concentrations which fail to block cells at mitosis were also unable to activate apotosis. A detailed time-course analysis of cell cycle arrest and apoptosis indicated that after CA-4 washout the number of metaphases with "star-like" structures decreased as a function of time and arrested cells proceeded in anaphase. After 4 h, the multiple alpha- and gamma-tubulin aggregates coalesced into two well-defined spindles in a bipolar mitotic spindle organization. Overall, our findings suggest that the maintenance of microtubular integrity plays a relevant role in stabilising the pericentriolar matrix, whose dismantling can be associated with apoptosis after exposure to microtubule depolymerising agents.

Topics: Apoptosis; Carcinoma, Non-Small-Cell Lung; Cell Line, Tumor; Humans; Lung Neoplasms; Microscopy, Confocal; Microscopy, Electron, Transmission; Microtubules; Mitosis; Stilbenes; Tubulin Modulators

Combretastatin A-4 (CA-4), a natural stilbenoid isolated from Combretum caffrum, is a new vascular targeting agent (VTA) known for its antitumor activity due to its anti-tubulin properties. We investigated the molecular mechanisms leading to cell death in non-small cell lung cancer H460 cells induced by natural (CA-4) and synthetic stilbenoids (ST2151) structurally related to CA-4. We found that both compounds induced depolymerization and rearrangement of spindle microtubules, as well as an increasingly aberrant organization of metaphase chromosomes in a dose- and time-dependent manner. Prolonged exposition to ST2151 led cells to organize multiple sites of tubulin repolymerization, whereas tubulin repolymerization was observed only after CA-4 washout. H460 cells were arrested at a pro-metaphase stage, with condensed chromosomes and a triggered spindle assembly checkpoint, as evaluated by kinetochore localization of Bub1 and Mad1 antibodies. Persistent checkpoint activation led to mitochondrial membrane permeabilization (MMP) alterations, cytochrome c release, activation of caspase-9 and -3, PARP cleavage and DNA fragmentation. On the other hand, caspase-2, and -8 were not activated by the drug treatment. The ability of cells to reassemble tubulin in the presence of an activated checkpoint may be responsible for ST2151-induced multinucleation, a recognized sign of mitotic catastrophe. In conclusion, we believe that discovery of new agents able to trigger mitotic catastrophe cell death as a result of mitotic block and prolonged spindle checkpoint activation is particularly worthwhile, considering that tumor cells have a high proliferative rate and mitotic failure occurs irrespective of p53 status.

Topics: Antineoplastic Agents, Phytogenic; Apoptosis; Carcinoma, Non-Small-Cell Lung; Caspase 3; Cell Line, Tumor; Cytochromes c; Enzyme Activation; Humans; Lung Neoplasms; Microscopy, Electron; Microtubules; Mitochondria; Mitosis; Spindle Apparatus; Stilbenes

The tumor vascular effects of radiotherapy and subsequent administration of the vascular disrupting agent combretastatin A4 phosphate (CA4P) were studied in patients with advanced non-small-cell lung cancer using volumetric dynamic contrast-enhanced computed tomography (CT).. Following ethical committee approval and informed consent, 8 patients receiving palliative radiotherapy (27 Gy in six fractions, twice weekly) also received CA4P (50 mg/m(2)) after the second fraction of radiotherapy. Changes in dynamic CT parameters of tumor blood volume (BV) and permeability surface area product (PS) were measured for the whole tumor volume, tumor rim, and center after radiotherapy alone and after radiotherapy in combination with CA4P.. After the second fraction of radiotherapy, 6 of the 8 patients showed increases in tumor PS (23.6%, p = 0.011). Four hours after CA4P, a reduction in tumor BV (22.9%, p < 0.001) was demonstrated in the same 6 patients. Increase in PS after radiotherapy correlated with reduction in BV after CA4P (r = 0.77, p = 0.026). At 72 h after CA4P, there was a sustained reduction in tumor BV of 29.4% (p < 0.001). Both increase in PS after radiotherapy and reduction in BV after CA4P were greater at the rim of the tumor. The BV reduction at the rim was sustained to 72 h (51.4%, p = 0.014).. Radiotherapy enhances the tumor antivascular activity of CA4P in human non-small-cell lung cancer, resulting in sustained tumor vascular shutdown.

Topics: Antineoplastic Agents, Phytogenic; Blood Volume; Capillary Permeability; Carcinoma, Non-Small-Cell Lung; Combined Modality Therapy; Contrast Media; Female; Humans; Lung Neoplasms; Male; Stilbenes; Tomography, X-Ray Computed

TZT-1027 (Soblidotin), an antimicrotubule agent, has been demonstrated to show potent antitumor effects, though the relationships among antitumor effect, cytotoxicity and anti-vascular effect of TZT-1027 have not been studied. We established in vivo human lung vascular-rich tumor models using a vascular endothelial growth factor-secreting tumor (SBC-3/VEGF). SBC-3/VEGF tumors exhibited a high degree of angiogenesis in comparison with the mock transfectant (SBC-3/Neo) tumors in a dorsal skinfold chamber model and grew much faster and larger than SBC-3/Neo tumors in the tumor growth study. The antitumor activity of antimicrotubule agents, including TZT-1027, was evaluated in both early- and advanced-stage SBC-3/Neo and SBC-3/VEGF tumor models to elucidate the relationship between the antitumor activity and anti-vascular effect of these agents. TZT-1027 exhibited potent antitumor activity against both early- and advanced-stage SBC-3/Neo and SBC-3/VEGF tumors, whereas combretastatin A4 phosphate did not. Vincristine and docetaxel exhibited potent antitumor activity against early-stage SBC-3/Neo and SBC-3/VEGF tumors, and advanced-stage SBC-3/Neo tumors, but did not exhibit activity against advanced-stage SBC-3/VEGF tumors. The difference in antitumor activity between these agents could be ascribed to differences in direct cytotoxicity and anti-vascular effect. Furthermore, a prominent accumulation of erythrocytes in the tumor vasculature, followed by leakage and scattering of these erythrocytes from the tumor vasculature, was observed after TZT-1027 administration to mice bearing advanced-stage SBC-3/VEGF tumors. These findings strongly suggest that TZT-1027 has a potent anti-vascular effect, in addition to direct cytotoxicity.

Topics: Animals; Antineoplastic Agents; Carcinoma, Small Cell; Cell Survival; Docetaxel; Erythrocytes; Female; Gene Expression Regulation, Neoplastic; Humans; Leukemia P388; Lung Neoplasms; Mice; Mice, Inbred BALB C; Mice, Nude; Neoplasms, Experimental; Neovascularization, Pathologic; Oligopeptides; Skin; Stilbenes; Taxoids; Transfection; Vascular Endothelial Growth Factor A; Vincristine

Combretastatin A-4 prodrug (CA-4PD) has been identified as a potent antivascular agent in various rodent tumor models. The aim of this study was to investigate the effect of CA-4PD on human non-small cell lung cancer (NSCLC).. Cytostatic and cytotoxic effects of CA-4PD on selected NSCLC cells, Colo-699 and KNS-62, were studied in vitro. After subcutaneous xenotransplantation the effect of systemically administrated CA-4PD on tumor growth was investigated in vivo. A newly established orthotopic xenotransplant model was employed to estimate prolongation of survival after intrapulmonary tumor induction with secondary metastatic disease.. In vitro, CA-4PD displayed a time and dose dependent antiproliferative effect on human lung cancer cells. In vivo, CA-4PD significantly delayed growth of subcutaneously induced lung cancer. This growth delay was translated into a prolongation of survival in the metastasizing orthotopic xenotransplant model.. In vitro CA-4PD inhibits proliferation of NSCLC cells, most likely by disruption of microtubule assembly. In vivo, systemic treatment inhibits growth of subcutaneously xenotransplanted tumors by an antivascular effect. In the case of metastasizing human lung cancer this translated into a prolongation of survival.

Topics: Adenocarcinoma; Animals; Antineoplastic Agents, Phytogenic; Carcinoma, Non-Small-Cell Lung; Carcinoma, Squamous Cell; Cell Division; Cell Survival; Dose-Response Relationship, Drug; Female; Humans; Lung Neoplasms; Mice; Mice, SCID; Neoplasm Transplantation; Prodrugs; Stilbenes; Tumor Cells, Cultured

The requirement for tumour vascularisation to permit the expansion of solid tumours beyond a threshold size of approximately 1 mm diameter has focussed attention on anti-vascular and anti-angiogenic agents for cancer therapy. Combretastatin-A4 (cis CA-4P) is a tubulin-binding agent that is cytotoxic for proliferating endothelial cells in vitro and causes anti-vascular effects in the established tumour vessels of some primary tumours. Preliminary data from Phase I clinical trials indicate that cis CA-4 may also be effective in targeting the vasculature of human tumours. As metastatic disease is the principal cause of mortality in cancer, we have investigated the effects of cis CA-4 on metastatic development using an in vivo model. We show that bolus or continuous administration of cis CA-4P results in potent inhibition of metastases derived from ectopic primary Lewis lung carcinomas in mice whereas the trans CA-4 isomer is without effect. These data further characterise the activity of CA-4 in vivo and suggest that the drug should be evaluated clinically as an anti-metastatic agent.

Topics: Animals; Antineoplastic Agents, Phytogenic; Carcinoma, Lewis Lung; Immunoenzyme Techniques; Lung; Lung Neoplasms; Male; Mice; Mice, Inbred C57BL; Neovascularization, Pathologic; Stilbenes; von Willebrand Factor

As part of our continuing search for potential anticancer drug candidates in the 2-phenyl-4-quinolone series, we have synthesized a series of 6,7-methylenedioxy-substituted and unsubstituted 2-phenyl-4-quinolones, as well as related compounds. Their in vitro inhibition of human tumor cell lines and tubulin polymerization is reported. In general, a good correlation was found between cytotoxicity and inhibition of tubulin polymerization. Compounds 7, 9, 13, 16, 22, 23, 36, and 37 showed potent inhibitory effects in both assays. All rigid analogs (47-49) and trimethoxy-substituted compounds showed little or no activity. Substitution at the 4'-position also resulted in compounds with little or no activity, except for hydroxyl or methyl groups at this position. Further investigation is underway to determine if substitution at the 3'-position will result in compounds with increased activity.

Topics: Animals; Antineoplastic Agents; Breast Neoplasms; Carcinoma, Small Cell; Cattle; Cell Division; Central Nervous System Neoplasms; Colonic Neoplasms; Female; Humans; Leukemia; Lung Neoplasms; Molecular Structure; Polymers; Quinolones; Structure-Activity Relationship; Tubulin; Tubulin Modulators; Tumor Cells, Cultured

A series of 1,6,7,8-substituted 2-(4'-substituted phenyl)-4-quinolones and related compounds have been synthesized and evaluated as cytotoxic compounds and as antimitotic agents interacting with tubulin. The 2-phenyl-4-quinolones (22-30) with substituents (e.g. F, Cl, and OCH3) at C-6, C-7, and C-8 show, in general, potent cytotoxicity against human lung carcinoma (A-549), ileocecal carcinoma (HCT-8), melanoma (RPMI-7951), and epidermoid carcinoma of the nasopharynx (KB) and two murine leukemia lines (P-388 and L1210). Introduction of alkyl groups at N-1 or C-4 oxygen led to inactive compounds (35-43 and 50). In addition, compounds 24, 26, and 27 were evaluated in the National Cancer Institute's 60 human tumor cell line in vitro screen. These compounds demonstrated the most marked effects in the screen on two colon carcinoma cell lines (COLO-205 and KM-20L2) and on a central nervous system tumor cell line (SF-539) with compound 26 the most potent of the three agents. Compounds 24, 26, and 27 were potent inhibitors of tubulin polymerization, with activity nearly comparable to that of the potent antimitotic natural products colchicine, podophyllotoxin, and combretastatin A-4. The three agents also inhibited the binding of radiolabeled colchicine to tubulin, but this inhibition was less potent than that obtained with the natural products.

Topics: Animals; Antineoplastic Agents; Humans; Intestinal Neoplasms; Leukemia L1210; Leukemia P388; Lung Neoplasms; Melanoma; Mice; Molecular Structure; Nasopharyngeal Neoplasms; Quinolines; Quinolones; Software; Structure-Activity Relationship; Tubulin; Tubulin Modulators; Tumor Cells, Cultured

A series of stilbenes has been prepared and tested for cytotoxicity in the five human cancer cell lines A-549 non-small cell lung, MCF-7 breast, HT-29 colon, SKMEL-5 melanoma, and MLM melanoma. The cis stilbenes 6a-f proved to be cytotoxic in all five cell lines, with potencies comparable to that of combretastatin A-4. These cytotoxic compounds were all potent inhibitors of tubulin polymerization. The corresponding trans stilbenes 7b-f were inactive as tubulin polymerization inhibitors and were significantly less cytotoxic in the five cancer cell lines. In the dihydro series, 8b, 8c, and 8f were inactive as tubulin polymerization inhibitors, while 8a, 8d, and 8e were less active than the corresponding cis compounds 6a, 6d, and 6e. The lack of tubulin polymerization inhibitory activity and cytotoxicity displayed by the phenanthrene 23b, which was synthesized as a conformationally rigid analogue of the lead compound 1, indicates that the activity of the stilbenes is not due to a totally planar conformation. Similarly, inactivity of the conformationally restricted analogue 26 suggests that the biologically active conformation of 1a resembles that of the cis alkene 1. Additional inactive compounds prepared include the benzylisoquinoline series 28-32 as well as the protoberberines 38 and 39. Shortening the two-carbon bridge of 1a to a one-carbon bridge in the diphenylmethane 20 resulted in a decrease in cytotoxicity and tubulin polymerization inhibitory activity. Although the corresponding benzophenone 18 was as active as 1a as a tubulin polymerization inhibitor, it was less cytotoxic than 1a, and the benzhydrol 19 was essentially inactive. With the exception of the amide 15c, which displayed low antitubulin activity, all of the phenylcinnamic acid derivatives 14a-c and 15a-f were inactive in the tubulin polymerization inhibition assay. The acid 14b and the ester 15a were cytotoxic in several of the cancer cell cultures in spite of their inactivity as tubulin polymerization inhibitors.

Topics: Antineoplastic Agents; Breast Neoplasms; Cell Division; Colonic Neoplasms; Humans; Lung Neoplasms; Melanoma; Stilbenes; Structure-Activity Relationship; Tubulin; Tubulin Modulators; Tumor Cells, Cultured

An array of cis-, trans-, and dihydrostilbenes and some N-arylbenzylamines were synthesized and evaluated for their cytotoxicity in the five cancer cell cultures A-549 lung carcinoma, MCF-7 breast carcinoma, HT-29 colon adenocarcinoma, SKMEL-5 melanoma, and MLM melanoma. Several cis-stilbenes, structurally similar to combretastatins, were highly cytotoxic in all five cell lines and these were also found to be active as inhibitors of tubulin polymerization. The most active compounds also inhibited the binding of colchicine to tubulin. The most potent of the new compounds, both as a tubulin polymerization inhibitor and as a cytotoxic agent, was (Z)-1-(4-methoxyphenyl)-2-(3,4,5-trimethoxyphenyl)ethene (5a). This substance was almost as potent as combretastatin A-4 (1a), the most active of the combretastatins, as a tubulin polymerization inhibitor. Compound 5a was found to be approximately 140 times more cytotoxic against HT-29 colon adenocarcinoma cells and about 10 times more cytotoxic against MCF-7 breast carcinoma cells than combretastatin A-4. However, 5a was found to be about 20 times less cytotoxic against A-549 lung carcinoma cells, 30 times less cytotoxic against SKMEL-5 melanoma cells, and 7 times less cytotoxic against MLM melanoma cells than combretastatin A-4. The relative potencies 5a greater than 8a greater than 6a for the cis, dihydro, and trans compounds, respectively, as inhibitors of tubulin polymerization are in agreement with the relative potencies previously observed for combretastatin A-4 (1a), dihydrocombretastatin A-4 (1c), and trans-combretastatin A-4 (1b). The relative potencies 5a greater than 8a greater than 6a were also reflected in the results of the cytotoxicity assays. Structure-activity relationships of this group of compounds are also discussed.

Topics: Antineoplastic Agents; Antineoplastic Agents, Phytogenic; Breast Neoplasms; Chemical Phenomena; Chemistry; Colchicine; Colonic Neoplasms; Humans; Lung Neoplasms; Melanoma; Molecular Structure; Polymers; Stilbenes; Structure-Activity Relationship; Tubulin; Tubulin Modulators; Tumor Cells, Cultured