Cell Carcinoma Of Cervix Research Articles

Conjugates of Modified Cryptophycins and RGD-Peptides Enter Target Cells by Endocytosis

Tumor targeting anticancer drug conjugates that contain a tumor recognition motif (homing device) are of high current relevance. Cryptophycins, naturally occurring cytotoxic cyclo-depsipeptides, have been modified by total synthesis to provide analogues suitable for conjugation to peptide-based homing devices. An array of functionalized β(2)-amino acids was synthesized and incorporated into cryptophycins. All analogues proved to be highly active in the cytotoxicity assay using the human cervix carcinoma cell line KB-3-1 and its multidrug-resistant subclone KB-V1. Conformational analysis of cryptophycin-52 and two synthetic analogues was performed by NMR and MD methods to obtain information on the influence of the unit C configuration on the overall conformation. An azide-functionalized cryptophycin was connected by CuAAC to an alkyne-containing fluorescently labeled cyclic RGD-peptide as the homing device for internalization studies. Confocal fluorescence microscopy proved integrin-mediated internalization by endocytosis and final lysosomal localization of the cryptophycin prodrug.

Correlation of MAGE-A tumor antigens and the efficacy of various chemotherapeutic agents in head and neck carcinoma cells

The present study examined the relationship between MAGE-A tumor antigens and the efficacy of diamindichloridoplatin (DDP), 5-fluorouracil (5-FU), docetaxel, and paclitaxel for in vitro treatment of head and neck cancer. In the present study, five cell lines of human squamous cell carcinomas were treated with DDP (25-400μM), 5-FU (0.75-12mM), docetaxel (1.56-25nM), and paclitaxel (1.56-25nM) for a period of 24 or 48h. The efficacy of the agents was observed dynamically using real-time cell analysis. Subsequently, the expression levels of MAGE-A1, MAGE-A5, MAGE-A8, MAGE-A9, MAGE-A11, and MAGE-A12 were determined by quantitative real-time polymerase chain reaction. Chemosensitivity and MAGE-A-expression were correlated by linear regression. The tumor cell lines showed a highly differentiated response to the chemotherapeutic agents. Expression of MAGE-A11 was significantly associated with a poorer response to treatment with DDP, 5-FU, docetaxel, and paclitaxel. Two cell lines, one of which was MAGE-A11-positive, showed a significant and concentration-dependent cisplatin-induced growth spurt during the first 24h after treatment. MAGE-A5 was connected to a positive effect on treatment with paclitaxel within the first 24h after application. In association with docetaxel treatment, MAGE-A8 was connected to a poorer susceptibility. The results describe, for the first time, a correlation between these MAGE-A tumor antigens and the susceptibility of head and neck cancer cells to DDP, 5-FU, docetaxel, and paclitaxel. These findings could affect the antineoplastic treatment of patients with MAGE-A11-positive tumors.

PO-100: Identification of Head and Neck Carcinoma Cell Lines with a Mesenchymal Phenotype.

PO-100: Identification of Head and Neck Carcinoma Cell Lines with a Mesenchymal Phenotype.

Evaluation of naproxen and cromolyn activities against cancer cells viability, proliferation, apoptosis, p53 and gene expression of survivin and caspase-3

We previously reported the inhibitory profiles of naproxen and cromolyn against glycogen synthase kinase-3β, which partly explain the molecular mechanisms of their anti-cancer properties. In this study, we performed a detailed biochemical evaluation of the two drugs against colorectal adenocarcinoma (Caco2), hepatocellular carcinoma (HepG2), mammary gland carcinoma (MCF7), epitheloid cervix carcinoma (Hela), lung carcinoma (A5W9) and epidermoid larynx carcinoma (Hep2) cell lines. Additionally, we performed cellular viability tests using trypan blue, proliferation MTT assay, apoptosis, p53 and real-time polymerase chain reaction for gene expression of survivin and caspase-3. Not only the two drugs were found to significantly reduce the viability of different cell lines, but they also were shown to have potent dose-dependent reduction of cellular proliferation. They exhibited cytotoxicity IC50 values of 3.69 and 4.16 μM for naproxen and cromolyn, respectively. Viability and proliferation results clearly correlated with apoptosis and p53 experiments in showing that both drugs significantly raised apoptotic percentages. Furthermore, we observed a significant reduction in survivin and elevation of caspase-3 gene expression upon exposure to the two drugs. It can be concluded that both naproxen and cromolyn have significant anti-cancer properties.

A ROS-mediated lysosomal–mitochondrial pathway is induced by a novel Amonafide analogue, 7c, in human Hela cervix carcinoma cells

In this study, a novel naphthalimide derivative 7c was designed which is topo II inhibiting though owning weak DNA binders. It was shown that 7c could induce cancer cells apoptosis and have less cytotoxicity in normal human cell. Further investigations on Hela cells revealed that 7c could also induce ROS generation, lysosome rupture as well as cathepsin B release. Subsequent mitochondrial damages including mitochondrial membrane permeabilization and the release of cytochrome c were also found in 7c when treating with Hela cells. According to our data, 7c may act as a lead compound for potential anticancer drugs. The idea of naphthalimides modification may also provide a novel strategy for naphthalimides design.

Characterization of Adult α- and β-Globin Elevated by Hydrogen Peroxide in Cervical Cancer Cells That Play A Cytoprotective Role Against Oxidative Insults

ObjectivesHemoglobin (Hgb) is the main oxygen and carbon dioxide carrier in cells of erythroid lineage and is responsible for oxygen delivery to the respiring tissues of the body. However, Hgb is also expressed in nonerythroid cells. In the present study, the expression of Hgb in human uterine cervix carcinoma cells and its role in cervical cancer were investigated.MethodologyThe expression level of Hgb in cervical cancer tissues was assessed by quantitative reverse transcriptase-PCR (qRT-PCR). We applied multiple methods, such as RT-PCR, immunoblotting, and immunohistochemical analysis, to confirm Hgb expression in cervical cancer cells. The effects of ectopic expression of Hgb and Hgb mutants on oxidative stress and cell viability were investigated by cellular reactive oxygen species (ROS) analysis and lactate dehydrogenase (LDH) array, respectively. Both Annexin V staining assay by flow cytometry and caspase-3 activity assay were used, respectively, to evaluate cell apoptosis.ResultsqRT-PCR analysis showed that Hgb-α- (HBA1) and Hgb-β-globin (HBB) gene expression was significantly higher in cervical carcinoma than in normal cervical tissues, whereas the expression of hematopoietic transcription factors and erythrocyte specific marker genes was not increased. Immunostaining experiments confirmed the expression of Hgb in cancer cells of the uterine cervix. Hgb mRNA and protein were also detected in the human cervical carcinoma cell lines SiHa and CaSki, and Hgb expression was up-regulated by hydrogen peroxide-induced oxidative stress. Importantly, ectopic expression of wild type HBA1/HBB or HBA1, rather than mutants HBA1H88R/HBBH93R unable to bind hemo, suppressed oxidative stress and improved cell viability.ConclusionsThe present findings show for the first time that Hgb is expressed in cervical carcinoma cells and may act as an antioxidant, attenuating oxidative stress-induced damage in cervical cancer cells. These data provide a significant impact not only in globin biology but also in understanding of cervical cancer pathogenesis associated with oxidative stress.

A literature review of small cell carcinoma of the cervix

Case summary A 97-year-old lady had a cervical biopsy for a fungating mass. The specimen showed fragments of poorly differentiated carcinoma characterised by sheets of tightly packed small cells with hyperchromatic nuclei, nuclear moulding, fine granular chromatin and scanty cytoplasm. There was no glandular or squamous differentiation. Subjacent to the tumour, there was a full thickness dysplasia consistent with cervical intraepithelial neoplasia (CIN) 3. The tumour stained for neuroendocrine markers comprising of chromogranin, synaptophysin and NSE. It was also positive for polyclonal CEA. The squamous epithelium with CIN3 stained for p16-INK4. The findings support small cell carcinoma of cervical origin. Discussion Small cell carcinoma accounts for 1–6% of cervical carcinoma. Overexpression of p16-INK4 and the presence of HPV18 E7 have been previously reported in small cell carcinoma of the uterine cervix. Therefore, inactivation of RB protein by HPV18 E7 protein is associated with carcinogenesis of small cell carcinoma. It is clinically aggressive and frequently presents with parametrial invasion and pelvic lymph node metastases. The reported 5 year survival rate is 14–39%.

Biodegradability and cytotoxicity of choline soaps on human cell lines: effects of chain length and the cation

Using choline as a counterion in fatty acid surfactants substantially increases their water solubility as compared to classical sodium and potassium soaps, and thereby enables the application of desirable longer-chain derivatives at ambient temperature. Since choline can be decomposed both physiologically and environmentally, corresponding fatty acid soaps are considered to be highly biocompatible. Recent toxicity and biodegradability studies of choline ionic liquids, including anions such as short- and middle-chain alkanoates, have verified the expected low toxic impact. However, according to the European Cosmetic Directive 76/768/EEC, all salts of choline are forbidden in cosmetic products, mainly just due to its classification as a quaternary ammonium ion. In order to facilitate their application in the future, we have investigated the biodegradability of choline soaps (ChCm) with alkyl chain lengths of m = 12–18 according to the OCDE 301F standard. Further, the cytotoxicity of ChCm surfactants with m = 8–16 was determined, both for odd- and even-numbered fatty acids. Studies were carried out using two different human cell lines, namely cervix carcinoma cells (HeLa) and keratinocytes (SK-Mel-28). For a better comparability to common soaps and to shed light on the influence of the cation, sodium and potassium homologues were also investigated. Results reveal an unexpected non-linear relationship between the hydrophobic chain length and the IC50 value. Most importantly, the presented data show that IC50 values of ChCm surfactants coincide with those of the widely applied sodium and potassium soaps. This demonstrates that choline carboxylate surfactants are harmless and thus strongly supports their applicability in customer end products.

Differential cytotoxicity of the glycolytic inhibitor 2-deoxy-D-glucose in isogenic cell lines varying in their p53 status

Earlier studies have shown that cytotoxicity of glycolic inhibitor 2-deoxy-D-glucose is heterogeneous among different tumor cell lines due to a number of reasons including difference in p53 status. To investigate the cytotoxic effects of 2-DG in isogenic cell systems that differ in their p53 status. Head and neck carcinoma cells KB and its two p53 mutants (KB68-mutation in transactivation domain (Arg/Cys) at position 68 and KB110-mutation in proline rich deoxyribonucleic acid binding domain (Glu/Gly) at position 110) were used as the model. Clonogenecity, cell proliferation, cell cycle, annexin V assay, intracellular levels of ROS and NADP+/NADPH levels were investigated as parameters for 2-DG induced cytotoxicity. Macrocolony assay showed that the cytotoxicity of 2-DG was time- and concentration-dependent. However, the sensitivity of the three cell lines were quantitatively different, with KB110 being more sensitive than the parental cell line KB and KB68. The effects of 2-DG on growth inhibition, cell cycle, and apoptosis correlated well with the changes in cell survival in these cells. A higher degree of 2-DG induced enhancement in the metabolic oxidative stress was evident in both the mutant cell lines (elevated ROS level and NADP+/NADPH ratio) suggestive of a higher degree of compromize in the antioxidant defense in the mutant cells. 2-DG could be considered as a potential therapeutic agent that induces cell death (which could be linked to induced oxidative stress) selectively in tumors with p53 mutations (particularly in the proline rich region).

Head and neck cancer cells and xenografts are very sensitive to palytoxin: decrease of c-jun n-terminale kinase-3 expression enhances palytoxin toxicity

ObjectivesPalytoxin (PTX), a marine toxin isolated from the Cnidaria (zooanthid) Palythoa caribaeorum is one of the most potent non-protein substances known. It is a very complex molecule that presents both lipophilic and hydrophilic areas. The effect of PTX was investigated in a series of experiments conducted in head and neck squamous cell carcinoma (HNSCC) cell lines and xenografts.Materials and methodsCell viability, and gene expression of the sodium/potassium-transporting ATPase subumit alpha1 (ATP1AL1) and GAPDH were analyzed in HNSCC cells and normal epithelial cells after treatment with PTX using cytotoxicity-, clonogenic-, and enzyme inhibitor assays as well as RT-PCR and Northern Blotting. For xenograft experiments severe combined immunodeficient (SCID) mice were used to analyze tumor regression. The data were statistically analyzed using One-Way Annova (SPSS vs20).ResultsSignificant toxic effects were observed in tumor cells treated with PTX (LD50 of 1.5 to 3.5 ng/ml) in contrast to normal cells. In tumor cells PTX affected both the release of LDH and the expression of the sodium/potassium-transporting ATPase subunit alpha1 gene suggesting loss of cellular integrity, primarily of the plasma membrane. Furthermore, strong repression of the c-Jun N-terminal kinase 3 (JNK3) mRNA expression was found in carcinoma cells which correlated with enhanced toxicity of PTX suggesting an essential role of the mitogen activated protein kinase (MAPK)/JNK signalling cascades pathway in the mechanisms of HNSCC cell resistance to PTX. In mice inoculated with carcinoma cells, injections of PTX into the xenografted tumors resulted within 24 days in extensive tumor destruction in 75% of the treated animals (LD50 of 68 ng/kg to 83 ng/kg) while no tumor regression occurred in control animals.ConclusionsThese results clearly provide evidence that PTX possesses preferential toxicity for head and neck carcinoma cells and therefore it is worth further studying its impact which may extend our knowledge of the biology of head and neck cancer.

Study of Cancer Cell Lines with Fourier Transform Infrared (FTIR)/ Vibrational Absorption (VA) Spectroscopy

In this work we have used Fourier transform infrared (FTIR) / vibrational absorption (VA) spectroscopy to study two cancer cell lines: the Henrietta Lacks (HeLa) human cervix carcinoma and 5637 human bladder carcinoma cell lines. Our goal is to experimentally investigate biochemical changes and differences in these cells lines utilizing FTIR spectroscopy. We have used the chemometrical and statistical method principal component analysis (PCA) to investigate the spectral differences. We have been able to identify certain bands in the spectra which are so-called biomarkers for two types of cell lines, three groups for the 5637 human bladder carcinoma cell line (5637A, 5637B and 5637C), and another one for the HeLa human cervix carcinoma cell line. The vibrational modes can be assigned to specific bands involving characteristic motions of the protein backbone. This work shows that infrared vibrational absorption (VA) spectroscopy can be used as a useful tool in medical diagnostics that provides in principle additional information and detail to that which can be obtained/provided from conventional histological studies, and more conventional mass spectroscopic and NMR techniques. The use of high level vibrational spectroscopic simulation, in addition to the chemometric and statistical tools of PCA, linear and quadratic discriminant analysis, and artificial networks methods that are good at finding correlations, but provide little if any physical, chemical and biochemical insight into the nature of the changes at a molecular level, is also strongly advocated and helpful to gain more physical, chemical and biological insight. Hence the combination of vibrational spectroscopic simulations and experimental vibrational absorption spectroscopy and imaging are advocated for future developments in this field.

Effect of an Isolated Active Compound (BVI03) of Boehmeria virgata (Forst) Guill leaves on Anti-Proliferation in Human Cancer Cervix HeLa Cells through Activation of Caspase 3 and p53 Protein

In this study, we found that BVI03 an alkaloid compound isolated from B. virgate induced antiproliferation against the human cervix carcinoma cell line HeLa. A MTT assay indicated that BVI03 had a strong tumor inhibition (IC50=0.126 μg/mL), which was superior to that of tamoxifen (IC50=2.879 μg/mL). This study also investigated the mechanism of antiproliferation induced by BVI03. Enzymatic activity using a colorimetric assay kit was performed to determine work mechanism of BVI03. Our data indicate that p53 and caspase-3 are involved in the process of BVI03-induced antiproliferative in HeLa cell compare with untreated HeLa cells.

Advances in study of cervical small cell carcinoma

Small cell carcinoma of cervix (SCCC) is a rare and high malignant neuroendocrine tumor.Because of its strong invasion,metastasis in early stage and easy recurrence,the prognosis is poor.Its diagnosis is based on pathomorphology,and immune-histochemistry biomarkers can improve its diagnosis.Combined therapy is recommended.Postoperative platinum/etoposide (PE),vincristine/adriamycin/cyclophosphamide (VAC) or taxel/carboplatin(TP) chemotherapy can improve the prognosis. Key words: Uterine cervical neoplasms; Surgical procedures,operative; Drug therapy; Radiotherapy

Cytotoxicity of herbal extracts used for treatment of prostatic disease on head and neck carcinoma cell lines and non-malignant primary mucosal cells

Previously, a growth inhibiting effect of PC-Spes on head and neck carcinoma cell lines had been demonstrated. In order to determine the toxic impact of particular herbs in the mixture, we exposed the head and neck cancer cell lines FADU, HLaC79 and its Paclitaxel-resistant subline HLaC79-Clone1 as well as primary mucosal keratinocytes to increasing concentrations of the herbal mixture Prostaprotect, which has a similar formulation as PC-Spes, as well as its single herbal components Dendranthema morifolium, Ganoderma lucidium, Glycyrrhiza glabra, Isatis indigotica, Panax pseudo-ginseng, Rabdosia rubescens, Scutellaria baicalensis and Pygeum africanum. Growth inhibition was measured using the MTT assay. Expression of P-glycoprotein (P-GP), multidrug resistance protein-1 (MRP-1), multidrug resistance protein-2 (MRP-2), breast cancer resistance protein (BCRP) and androgen receptor (AR) were examined by western blot analysis. Pygeum africanum extract clearly turned out as the main cytotoxic component of the Prostaprotect prescription mixture, and initated apoptosis in sensitive cell lines. All other extracts had only minor toxic effects. Western blot analysis revealed increased expression of P-GP in HLaC79-Clone1 cells, while HLaC79 and FADU cells were negative. All three cell lines were negative for MRP-1 and BCRP but positive for MRP-2. HLaC79 and its descendant HLaC79-Clone1 both expressed AR, as verified by western blotting and immunofluorescence staining. Primary mucosal keratinocytes were negative for all multidrug resistance markers as well as for AR. Growth inhibition rates of the single herbal extracts were compared with previously published results in prostate carcinoma cell lines. The relationship between expression levels of AR and multidrug resistance markers in relation to the measured toxicity of herbal extracts in our head and neck cancer cell system is critically discussed.

Microwave Assisted Synthesis, Characterization of Some New Isatin and Thiophene Derivatives as Cytotoxic and Chemopreventive Agents

In obtaining some new cytotoxic and chemopreventive agents with potent antiproliferative activity against cancer cells, a series of new β-isatin aldehyde-N,N’-thiocarbohydrazone, bis-β-isatin thiocarbohydrazones, bis-β-isatin carbohydrazones, N,2-bis(thiophen-2-ylmethylidene) thiocarbohydrazone and N,2-bis(thiophen-2-ylmethylidene) carbohydrazone derivatives was synthesized by microwave oriented reaction and evaluated for their in vitro cytotoxic activity. The newly synthesized compounds were characterized based on spectral (FT-IR, NMR, MS) analyses. The inhibitory effects of synthesized compounds on the proliferation of murine leukemia cells (L1210), human T-lymphocyte cells (CEM) and human cervix carcinoma cells (HeLa) were assayed by using MTT assay. The compounds were also tested for their inhibitory effects on Epstein-Barr virus early antigen (EBV-EA) activation induced by 12-Otetradecanoylphorbol- 13-acetate (TPA). In vitro evaluation of these schiff bases revealed mild to moderate cytotoxic activity in a dose dependent manner. The results of the in vitro inhibitory activities of synthetic compounds against EBVEA activation with IC50 ranges from 485-535 (mol ratio/32pmol/TPA). Chlorine group containing derivatives did not show increased inhibitory activity against tumor promoter TPA induction. Sulphur containing derivatives also did not show a high inhibitory potency in this system. Keywords: Carbohydrazide, Cytotoxic activity, Epstein-Barr virus antigen (EBV-EA) activation, Isatin, Thiophene-2- carboxaldehyde, Thiocarbohydrazide, Isatin–β-thiosemicarbazone derivatives, antihistamine, Cancer chemoprevention

Construction and characterization of a reporter gene cell line for assessment of human glucocorticoid receptor activation

Glucocorticoids are widely used drugs in human pharmacotherapy. There is an increasing demand for tools allowing detection of the ligands for glucocorticoid receptor (GR), with regard to pre-clinical drug testing and environmental applications. We constructed human luciferase reporter gene cell line AZ-GR derived from HeLa human cervix carcinoma cells, which were stably transfected with reporter plasmid containing three copies of glucorticoid response element (GRE) upstream of luciferase reporter gene. We isolated five dexamethasone-responsive clones, and we further characterized two most responsive ones (AZ-GR). Dose–response analyses were performed with 22 different natural and synthetic steroids and the values of EC50 were calculated. AZ-GR cells displayed high specificity and sensitivity to glucocorticoids, very low responsiveness to mineralocorticoids, but no responsiveness to estrogens, gestagens or androgens. Time-course analyses revealed that AZ-GR cells allow detection of GR activators soon after 14h of the treatment (6–10-fold induction by 100nM dexamethasone). Functionality of AZ-GR cells was not affected with cryopreservation. Generated reporter gene cell lines fully maintained responsiveness to glucocorticoids for 32days in the culture and over 16 passages without significant alterations. The sensitivity of the assay allows high throughput format using 96-well plates.Collectively, we present here glucocorticoid-responsive stable reporter gene cell line that allows high throughput, rapid, sensitive and selective detection of GR activators, with possible use in pre-clinical research and environmental applications.

Inhibition of Autophagy as a Strategy to Augment Radiosensitization by the Dual Phosphatidylinositol 3-Kinase/Mammalian Target of Rapamycin Inhibitor NVP-BEZ235

We investigated the effect of 2-methyl-2-{4-[3-methyl-2-oxo-8-(quinolin-3-yl)-2,3-dihydro-1H-imidazo[4,5-c]quinolin-1-yl]phenyl} propanenitrile (NVP-BEZ235) (Novartis, Basel Switzerland), a dual phosphatidylinositol 3-kinase (PI3K)/mammalian target of rapamycin (mTOR) inhibitor currently being tested in phase I clinical trials, in radiosensitization. NVP-BEZ235 radiosensitized a variety of cancer cell lines, including SQ20B head and neck carcinoma cells and U251 glioblastoma cells. NVP-BEZ235 also increased in vivo radiation response in SQ20B xenografts. Knockdown of Akt1, p110α, or mTOR resulted in radiosensitization, but not to the same degree as with NVP-BEZ235. NVP-BEZ235 interfered with DNA damage repair after radiation as measured by the CometAssay and resolution of phosphorylated H2A histone family member X foci. NVP-BEZ235 abrogated the radiation-induced phosphorylation of both DNA-dependent protein kinase catalytic subunit (DNA-PKcs) and ataxia telangiectasia mutated. Knockdown of either p110α or mTOR failed to decrease the phosphorylation of DNA-PKcs, suggesting that the effect of the drug was direct rather than mediated via p110α or mTOR. The treatment of cells with NVP-BEZ235 also promoted autophagy. To assess the importance of this process in radiosensitization, we used the autophagy inhibitors 3-methyladenine and chloroquine and found that either drug increased cell killing after NVP-BEZ235 treatment and radiation. Knocking down the essential autophagy proteins autophagy related 5 (ATG5) and beclin1 increased NVP-BEZ235-mediated radiosensitization. Furthermore, NVP-BEZ235 radiosensitized autophagy-deficient ATG5(-/-) fibroblasts to a greater extent than ATG5(+/+) cells. We conclude that NVP-BEZ235 radiosensitizes cells and induces autophagy by apparently distinct mechanisms. Inhibiting autophagy via pharmacologic or genetic means increases radiation killing after NVP-BEZ235 treatment; hence, autophagy seems to be cytoprotective in this situation. Our data offer a rationale for combining NVP-BEZ235 along with an autophagy inhibitor (i.e., chloroquine) and radiation in future clinical trials.

Alendronate-Conjugated Amphiphilic Hyperbranched Polymer Based on Boltorn H40 and Poly(ethylene glycol) for Bone-Targeted Drug Delivery

A novel type of alendronate(ALE)-conjugated amphiphilic hyperbranched copolymer based on a hydrophobic hyperbranched Boltorn H40 (H40) core with ALE targeting moiety and many hydrophilic poly(ethylene glycol) (PEG) arms was synthesized as a carrier for bone-targeted drug delivery. The star copolymer H40-star-PEG/ALE was characterized using nuclear magnetic resonance (NMR), Fourier transformed infrared spectroscopy (FTIR), and gel permeation chromatography (GPC) analysis. Benefiting from its highly branched structure, H40-star-PEG/ALE could form micelles in aqueous solution, which was confirmed by transmission electron microscopy (TEM) and dynamic light scattering (DLS) techniques. The cytotoxicity and hemolysis of the H40-star-PEG/ALE micelles were evaluated via methylthiazoletetrazolium (MTT) assay against NIH/3T3 normal cells and red blood cell (RBC) lysis assay, respectively. As a model anticancer drug, doxorubicin (DOX) was encapsulated into the H40-star-PEG/ALE micelles. The anticancer activity of DOX-loaded micelles was evaluated by MTT assay against an HN-6 human head and neck carcinoma cell line. The strong affinity of H40-star-PEG/ALE micelles to bone was confirmed by the hydroxyapatite (HA) binding assay. These results indicate that the H40-star-PEG/ALE micelles are highly promising bone-targeted drug carriers for skeletal metastases.

Isolation, Biological Activity Evaluation, Structure Elucidation, and Total Synthesis of Eliamid: A Novel Complex I Inhibitor

Eliamid is a secondary metabolite isolated from two bacterial strains. This molecule features a linear polyketide backbone terminated by a tetramic acid amide moiety. Among other biological activities, eliamid shows a high and specific cytostatic action on human lymphoma and cervix carcinoma cell lines. The 2,4-anti relative configuration of the C-2,C-4-dimethyl substituted amide fragment was assigned by means of Breit's rule. The absolute configuration of all stereocenters was determined by a combination of degradation methods, structural similarity analysis and total synthesis. The stereogenic centers were introduced by vinylogous Mukaiyama aldol reaction and two consecutive Myers alkylations. The use of pentafluorophenyl ester as acylation agent allowed the efficient formation of tetramic acid amide. The longest linear sequence in the synthesis consist of 13 steps and proceeds with 12% overall yield. Differential spectroscopy experiments with beef heart submitochondrial particles established that eliamid is a potent inhibitor of the NADH-ubiquinone oxidoreductase complex. Additionally, biosynthesis of eliamid was investigated by feeding experiments with (13)C-labeled precursors.

Radiosensitization by 2-deoxy-D-glucose and 6-aminonicotinamide involves activation of redox sensitive ASK1-JNK/p38MAPK signaling in head and neck cancer cells

Our previous studies on simultaneous inhibition of glycolysis by 2-deoxy-D-glucose (2-DG) and pentose phosphate activity by 6-aminonicotinamide (6-AN) have been shown to induce oxidative stress mediated selective radiosensitization in wide range of human malignant cells. However, the mechanism of radiosensitization induced by this combination (2-DG+6-AN) is not completely understood. Since activation of apoptotic signal regulating kinase (ASK1) and subsequent apoptosis are implicated in oxidative stress response, the role of ASK1 activation in radiosensitization by this combination was investigated in the present study. Our results demonstrated that redox alterations induced by this combination activated ASK1 and subsequent apoptosis during radiosensitization of head and neck carcinoma cells (KB). In addition, mRNA and protein expression of thioredoxin and thioredoxin reductase decreased significantly under similar treatment conditions. Further, the downstream targets such as JNK and p38MAPK were also activated by this combination, and their pharmacological inhibition by SP600125 and SB201291 respectively resulted in suppression of 2-DG+6-AN mediated apoptosis in irradiated KB cells. Interestingly, the activation of ASK1 was mediated by hydrogen peroxide rather than superoxide anions as PEG-catalase but not PEG-SOD suppressed its activation. Our observations clearly suggest that redox alterations by inhibition of glucose metabolism serves as a molecular switch that activate ASK1-JNK/p38MAPK signaling in malignant cells during radiosensitization by 2-DG+6-AN. The present study emphasizes the importance of redox alterations in determining radiosensitivity of tumor cells that may greatly influence the outcome of radiation therapy.