Cytotoxic effects of two organotin compounds and their mode of inflicting cell death on four mammalian cancer cells

In this report, we have tested the cytotoxicity of two organotin (OT) compounds by flow cytometry on a panel of immortalized cancer cell lines of human and murine origin. Although the OT compounds exhibited varying levels of cytotoxicity, diphenylmethyltin chloride was more toxic than 1,4-bis (diphenylchlorostannyl)p-xylene on all cell lines tested. The OT compounds were found to be highly cytotoxic to lymphoma cell lines with lower toxicity toward the HeLa cervical cancer cell line. In order to discern the mechanism by which cell death was induced, additional experiments were conducted to monitor characteristic changes consistent with apoptosis and/or necrosis. Cell lines treated with the experimental compounds indicated that there was no consistent mode of cell death induction. However, both compounds induced apoptosis in the pro-B lymphocyte cell line, NFS-70. The work presented here also demonstrates that the two OT compounds possess selective cytotoxicity against distinct transformed cell lines.     

Chemometric analysis of soy protein hydrolysates used in animal cell culture for IgG production – An untargeted metabolomics approach

Soy protein hydrolysates are used as the most cost effective medium supplement to enhance cell growth and recombinant protein productivity in cell cultures. Such hydrolysates contain diverse classes of compounds, such as peptides, carbohydrates and phenolic compounds. To identify if specific compounds dominate the functionality of hydrolysates in cell cultures, thirty samples of hydrolysates with different cell culture performances were analyzed for chemical composition using an untargeted metabolomics approach. Out of 410 detected compounds, 157 were annotated. Most of the remaining 253 compounds were identified as peptides, but could not be annotated exactly. All compounds were quantified relatively, based on their average signal intensities. The cell growth and total immunoglobulin (IgG) production, relative to the CD medium (100%), ranged from 148 to 438% and 117 to 283%, respectively. Using bootstrapped stepwise regression (BSR), the compounds with the highest inclusion frequency were identified. The most important compound, i.e. phenyllactate and ferulate explained 29% and 30% of the variance for cell growth and total IgG production, respectively. Surprisingly, all compounds identified in the BSR showed a positive correlation with cell growth and total IgG production. This knowledge can be applied to monitor the production and accumulation of these compounds during the production process of hydrolysates. Consequently, the processing conditions can be modulated to produce soy protein hydrolysates with enhanced and consistent cell culture performance.     

Correlation between the growth inhibitory effects, partition coefficients and teratogenic effects of lipophilic acids.

The inhibition of cell duplication by many lipophilic acids was measured in Bacillus subtilis and in the following mammalian cell lines, the human epithelial-type cell lines HeLa, strain R and strain L-132, the human fibroblast cell line VA-13, and the rat glial cell line C. The results were correlated to the partition coefficient and the distribution coefficient (= apparent partition coefficient at pH 7.2) of the compounds, using octanol/water partition coefficients and pKa values either from the literature or measured for this work. For B. subtilis, the logarithm of the inhibitory potency of most compounds increases linearly with the logarithm of the partition coefficient. Exceptional high potencies were observed for compounds that can efficiently delocalize the charge of the negative ion over the whole molecule. Most compounds inhibit tissue cultures at least as potently as they inhibit B. subtilis. But some compounds are significantly more potent in tissue cultures than would have been expected from the B. subtilis data; such compounds (analgesics/antipyretics, anti-inflammatory compounds, butyrate, norepinephrine) presumably inhibits mammalian cells by specific reactions with certain cell components. However, most compounds inhibit the different cell lines to a similar degree, indicating no cellular specificity; exceptions to this rule are chlorambucil, chlortetracycline and dexamethasone. Many of the lipophilic acids that are potent inhibitors of mammalian cell replication are also teratogenic. Exceptional compounds may not reach the embryo. We propose that a number of other lipophilic acids that are potenta inhibitors and to which humans are frequently exposed should be tested for their teratogenic effect.     

Investigation of the selenium metabolism in cancer cell lines

The aim of this work was to compare different selenium species for their ability to induce cell death in different cancer cell lines, while investigating the underlying chemistry by speciation analysis. A prostate cancer cell line (PC-3), a colon cancer cell line (HT-29) and a leukaemia cell line (Jurkat E6-1) were incubated with five selenium compounds representing inorganic as well as organic Se compounds in different oxidation states. Selenomethionine (SeMet), Se-methylselenocysteine (MeSeCys), methylseleninic acid (MeSeA), selenite and selenate in the concentration range 5-100 μM were incubated with cells for 24 h and the induction of cell death was measured using flow cytometry. The amounts of total selenium in cell medium, cell lysate and the insoluble fractions was determined by ICP-MS. Speciation analysis of cellular fractions was performed by reversed phase, anion exchange and size exclusion chromatography and ICP-MS detection. The selenium compounds exhibited large differences in their ability to induce cell death in the three cell lines and the susceptibilities of the cell lines were different. Full recovery of selenium in the cellular fractions was observed for all Se compounds except MeSeA. Speciation analysis showed that MeSeA was completely transformed during the incubations, while metabolic conversion of the other Se compounds was limited. Production of volatile dimethyl diselenide was observed for MeSeA and MeSeCys. MeSeA, MeSeCys and selenite showed noticeable protein binding. Correlations between cell death induction and the Se compounds transformations could not be demonstrated.     

Analysis of the cytotoxic effects of ruthenium–ketoconazole and ruthenium–clotrimazole complexes on cancer cells

Ruthenium-based compounds have intriguing anti-cancer properties, and some of these novel compounds are currently in clinical trials. To continue the development of new metal-based drug combinations, we coupled ruthenium (Ru) with the azole compounds ketoconazole (KTZ) and clotrimazole (CTZ), which are well-known antifungal agents that also display anticancer properties. We report the activity of a series of 12 Ru–KTZ and Ru–CTZ compounds against three prostate tumor cell lines with different androgen sensitivity, as well as cervical cancer and lymphoblastic lymphoma cell lines. In addition, human cell lines were used to evaluate the toxicity against non-transformed cells and to establish selectivity indexes. Our results indicate that the combination of ruthenium and KTZ/CTZ in a single molecule results in complexes that are more cytotoxic than the individual components alone, displaying in some cases low micromolar CC₅₀ values and high selectivity indexes. Additionally, all compounds are more cytotoxic against prostate cell lines with lower cytotoxicity against non-transformed epidermal cell lines. Some of the compounds were found to primarily induce cell death via apoptosis yet weakly interact with DNA. Our studies also demonstrate that the cytotoxicity induced by our Ru-based compounds is not directly related to their ability to interact with DNA.     

Retained platinum uptake and indifference to p53 status make novel transplatinum agents active in platinum-resistant cells compared to cisplatin and oxaliplatin

Despite the clinical success of platinum-containing drugs in the treatment of solid tumors, acquired resistance remains a major obstacle. We previously identified a group of novel transplanaramine or transplatinum compounds based on distinct activity profiles in the NCI-60 panel. In the present study, parental KB-3.1 cells with wild-type p53 and its cisplatin- and oxaliplatin-resistant sublines harboring mutant p53 proteins were used to contrast several transplatinum compounds with cisplatin and oxaliplatin. The transplatinum compounds retained cytotoxic activity in the resistant cell lines. While intracellular accumulation and DNA platination of cisplatin and oxaliplatin was decreased in the resistant cells, the transplatinum compounds both accumulated intracellularly and platinated DNA at comparable levels in all cell lines. Cytoflow analysis confirmed that cisplatin and oxaliplatin alter the cell cycle distribution and result in apoptosis; however, at comparably toxic concentrations, the transplatinum compounds did not alter the cell cycle distribution. Analysis of the cytoplasmic fraction treated with acetone showed that cisplatin and oxaliplatin readily bound to macromolecules in the pellet, whereas a larger percentage of the transplatinum compounds remained in the supernatant. We concluded that, distinct from platinum compounds currently in use, transplatinum compounds accumulate intracellularly in resistant cells at levels comparable to those in drug-sensitive cells, do not affect the cell cycle and thus retain cytotoxicity independent of p53 status and likely have cytoplasmic targets that are important in their activity.     

Retained platinum uptake and indifference to p53 status make novel transplatinum agents active in platinum-resistant cells compared to cisplatin and oxaliplatin

Despite the clinical success of platinum-containing drugs in the treatment of solid tumors, acquired resistance remains a major obstacle. We previously identified a group of novel transplanaramine or transplatinum compounds based on distinct activity profiles in the NCI-60 panel. In the present study, parental KB-3.1 cells with wild-type p53 and its cisplatin- and oxaliplatin-resistant sublines harboring mutant p53 proteins were used to contrast several transplatinum compounds with cisplatin and oxaliplatin. The transplatinum compounds retained cytotoxic activity in the resistant cell lines. While intracellular accumulation and DNA platination of cisplatin and oxaliplatin was decreased in the resistant cells, the transplatinum compounds both accumulated intracellularly and platinated DNA at comparable levels in all cell lines. Cytoflow analysis confirmed that cisplatin and oxaliplatin alter the cell cycle distribution and result in apoptosis; however, at comparably toxic concentrations, the transplatinum compounds did not alter the cell cycle distribution. Analysis of the cytoplasmic fraction treated with acetone showed that cisplatin and oxaliplatin readily bound to macromolecules in the pellet, whereas a larger percentage of the transplatinum compounds remained in the supernatant. We concluded that, distinct from platinum compounds currently in use, transplatinum compounds accumulate intracellularly in resistant cells at levels comparable to those in drug-sensitive cells, do not affect the cell cycle and thus retain cytotoxicity independent of p53 status and likely have cytoplasmic targets that are important in their activity.     

Synthesis and biological evaluation of podophyllotoxin congeners as tubulin polymerization inhibitors

A series of new podophyllotoxin derivatives containing structural modifications at C-7, C-8, and C-9 were synthesized and evaluated for their cytotoxic activity against three human cancer cell lines. All the synthesized compounds showed significant growth inhibition with GI₅₀ values in micromolar levels while some of the compounds were several times more potent against MCF-7 and HeLa cell lines than MIAPACA cell line. Three compounds (12a, 12d and 12e) emerged as potent compounds with broad spectrum of cytotoxic activity against all the tested cell lines with GI₅₀ values in the range of 0.01–2.1 μM. These compounds induce microtubule depolymerization and arrests cells at the G2/M phase of the cell cycle. Moreover, compounds 12d and 12e disrupted microtubule network and accumulated tubulin in the soluble fraction in a similar manner to their parent podophyllotoxin scaffold. In addition, structure activity relationship studies within the series were also discussed. Molecular docking studies of these compounds into the colchicine-binding site of tubulin, revealed possible mode of inhibition by these compounds.     

Selective inhibitors of death in mutant huntingtin cells

Huntington disease (HD) is an inherited neurodegenerative disorder with unclear pathophysiology. We developed a high-throughput assay in a neuronal cell culture model of HD, screened 43,685 compounds and identified 29 novel selective inhibitors of cell death in mutant huntingtin-expressing cells. Four compounds were active in diverse HD models, which suggests a role for cell death in HD; these compounds are mechanistic probes and potential drug leads for HD.     

Site of Action of Certain Antibacterial Heterocyclic Quaternary Ammonium Compounds

The site of action of related mono- and bis-quinaldinium compounds was investigated in Staphylococcus aureus and Bacillus megaterium. The effects of these compounds on cell morphology and on protoplast formation and fragility were studied, and the distribution of C(14)-labeled quinaldinium compound in cell fractions was measured. The latter studies showed that a major part of the quaternary compound penetrates the cell, leaving a very small quantity associated with the cell wall. Similar antibacterial effects were seen with both the mono- and bis-quinaldinium compounds studied, and these effects were comparable with antibacterial properties of known cationic surface-active antibacterial agents.     

5-(2'-oxoheptadecyl)-resorcinol and 5-(2'-oxononadecyl)-resorcinol,cytotoxic metabolites from a wood-inhabiting basidiomycete

5-(2'-oxoheptadecyl)-resorcinol [structure: see text] and 5-(2'-oxononadecyl)-resorcinol [structure: see text] were isolated from fermentations of an imperfect basidiomycete. The structures of the compounds were determined by spectroscopic techniques. Both compounds exhibit cytotoxic effects against the human colon tumor cell lines COLO-320, DLD-1 and HT-29 and the human promyeloid leukemia cell line HL-60, the human leukemia T cell JURKAT, the human hepatocellular carcinoma cell line HEP-G2 as well as the J774 mouse macrophage cell line. The compounds induce morphological and physiological differentiation of HL-60 cells into granulocytes, which subsequently die by apoptosis. Both compounds show no antibacterial and antifungal activity.     

A comprehensive study of Sansalvamide A derivatives: The structure–activity relationships of 78 derivatives in two pancreatic cancer cell lines

We report an extensive structure–activity relationship (SAR) of 78 compounds active against two pancreatic cancer cell lines. Our comprehensive evaluation of these compounds utilizes SAR that allow us to evaluate which features of potent compounds play a key role in their cytotoxicity. This is the first report of 19 new second-generation structures, where these new compounds were designed from the first generation of 59 compounds. These 78 structures were tested for their cytotoxicity and this is the first report of their activity against two pancreatic cancer cell lines. Our results show that out of 78 compounds, three compounds are worth pursuing as leads, as they show potency of ?55% in both cancer cell lines. These three compounds all have a common structural motif, two consecutive d-amino acids and an N-methyl moiety. Further, of these three compounds, two are second-generation structures, indicating that we can incorporate and utilize data from the first generation to design potency into the second generation. Finally, one analog is in the mid nanomolar range, and has the lowest IC₅₀ of any reported San A derivative. These analogs share no structural homology to current pancreatic cancer drugs, and are cytotoxic at levels on par with existing drugs treating other cancers. Thus, we have established Sansalvamide A as an excellent lead for killing multiple pancreatic cancer cell lines.     

Cytotoxic effect of some natural compounds isolated from Lauraceae plants and synthetic derivatives

Introduction. The antiproliferative effect of eleven neolignans, two lignans and one diterpene isolated from three Lauraceae plants, four benzofurans and two bicyclooctanes synthetic derivatives was evaluated in vitro on a set of five human cancer cells from solid tumors with a high incidence in Colombia. Objective. To evaluate the cytotoxic effect of twenty compounds on the tumor cell lines HeLa, A-549, Hep-2, PC-3, and MCF-7. Materials and methods. Fourteen natural compounds were isolated by chromatographic techniques from three native colombian plants (Pleurothyrium cinereum, Ocotea macrophylla and Nectandra amazonum), whose structures were established by spectroscopic methods; six synthetic derivatives were prepared by oxyarylation and diazomethane methylation. Antiproliferative effect and cell recovery were performed by means of in vitro treatment of tumor cell lines with test compounds, evaluating cell viability by resazurin staining. Results. Among test compounds, only neolignans ocophyllal A, cinerin D, kaurenoic acid, two benzofuran-derivatives, and synthetic (-)-cinerin A were found to have antiproliferative effect at different levels. Bicyclooctanoids as well as kaurenoic acid exhibited activity against all human cancer cells while benzofuranoids showed selective activity against HeLa. Furthermore, compounds (-)-cinerin A and kaurenoic acid exhibited total lethal effect against all-five cell lines and PC-3, Hep-2, and A549 cell lines, respectively. Conclusion. Test compounds exhibiting antiproliferative activity showed interesting results, which would promote their use as lead compounds on further studies for anticancer agents development.     

Synthesis of 6-chloroisoquinoline-5,8-diones and pyrido[3,4-b]phenazine-5,12-diones and evaluation of their cytotoxicity and DNA topoisomerase II inhibitory activity

The substituted chloroisoquinolinediones and pyrido[3,4-b]phenazinediones were synthesized, and the cytotoxic activity and topoisomerase II inhibitory activity of the prepared compounds were evaluated. Chloroisoquinolinediones have been prepared by the reported method employing 6,7-dichloroisoquinoline-5,8-dione. The cyclization to pyrido[3,4-b]phenazinediones was achieved by adding the aqueous sodium azide solution to the dimethylformamide solution of corresponding chloroisoquinoline-5,8-dione. The cytotoxicity of the synthesized compounds was evaluated by a SRB (Sulforhodamine B) assay against various cancer cell lines such as A549 (human lung cancer cell line), SNU-638 (human stomach cancer cell), Col2 (human colon cancer cell line), HT1080 (human fibrosarcoma cell line), and HL-60 (human leukemia cell line). Almost all the synthesized pyrido[3,4-b]phenazinediones showed greater cytotoxic potential than ellipticine (IC(50)=1.82-5.97 microM). In general, the cytotoxicity of the pyrido[3,4-b]phenazinediones was higher than that of the corresponding chloroisoquinolinediones. The caco-2 cell permeability of selected compounds was 0.62 x 10(-6)-35.3 x 10(-6)cm/s. The difference in cytotoxic activity among tested compounds was correlated with the difference in permeability to some degree. To further investigate the cytotoxic mechanism, the topoisomerase II inhibitory activity of the synthesized compounds was estimated by a plasmid cleavage assay. Most of compounds showed the topoisomerase II inhibitory activity (28-100%) at 200 microM. IC(50) values for the most active compound 6a were 0.082 microM. However, the compounds were inactive for DNA relaxation by topoisomerase I at 200 microM.     

Degrasyn-like symmetrical compounds: Possible therapeutic agents for multiple myeloma (MM-I)

A series of degrasyn-like symmetrical compounds have been designed, synthesized, and screened against B cell malignancy (multiple myeloma, mantle cell lymphoma) cell lines. The lead compounds T5165804 and CP2005 showed higher nanomolar potency against these tumor cells in comparison to degrasyn and inhibited Usp9x activity in vitro and in intact cells. These observations suggest that this new class of compounds holds promise as cancer therapeutic agents.     

Oleanolic acid derivatives induce apoptosis in human leukemia K562 cell involved in inhibition of both Akt1 translocation and pAkt1 expression

Oleanolic acid (OA) derivatives exhibit numerous pleiotropic effects in many cancers. The present study aimed to investigate the molecular mechanisms of 5′-amino-oleana-2,12-dieno[3,2-d]pyrimidin-28-oic acid (compound 4) and oleana-2,12-dieno[2,3-d]isoxazol-28-oic acid (compound 5) inducing apoptosis in human leukemia K562 cell. We investigated the effects of the compounds on K562 cell growth, apoptosis and cell cycle. The compounds showed strong inhibitory effects on K562 cell viability in a dose-dependent manner determined by the 3-(4,5-dimethylthiazoyl)-2,5-diphenyltetrazolium bromide assay and significantly increased chromatin condensation and apoptotic bodies in K562 cells. Flow cytometry assay suggested that the compounds induced inhibition of K562 cell proliferation associated with G1 phase arrest. In addition, the compounds inhibited Akt1 recruiting to membrane in CHO cells which express Akt1-EGFP constitutively and down-regulated the expression of pAkt1 in K562 cell. These results suggested that the compounds can efficiently inhibit proliferation and induce apoptosis perhaps involved in inactivation of Akt1. The OA derivatives may be potential chemotherapeutic agents for the treatment of human cancer.     

Effect of gibberellic acid on epicotyl growth and carbohydrate distribution in derooted Pisum sativum cuttings with or without cotyledons

The effect of gibberellic acid (GA) on subhook growth in derooted cuttings of pea ( Pisum sativum L. cv. Alaska) grown in the dark was studied in relation to the distribution of sugar-related compounds in the epicotyl and cotyledons. GA stimulated subhook growth of cuttings with or without cotyledons. In cuttings with cotyledons, the net inflow of sugar-related compounds (soluble sugars, starch, cell wall polysaccharides and sugars consumed by respiration) to the epicoiyl balanced with the net outflow from the cotyledons. GA stimulated the net inflow of sugar-related compounds to the epicotyl and the net outflow from cotyledons. Among these compounds, GA substantially increased the amount of soluble sugars, starch and cell wall polysaccharides in the subhook. In cuttings without cotyledons, on the other hand, the net inflow of sugar-related compounds to the subhook almost balanced with the net outflow from the epicotyl below the subhook. GA stimulated the net inflow of sugar-related compounds to the subhook and the net outflow from the epicotyl below the subhook. Among these compounds, GA substantially increased the amount of soluble sugars and cell wall polysaccharides in the subhook. These results suggest that GA stimulates an increase in the net inflow of sugar-related compounds to the subhook, thereby preventing an increase in osmotic potential and stimulating cell wall polysaccharide synthesis, when pea subhook growth is stimulated.     

Synthesis of chalcone-amidobenzothiazole conjugates as antimitotic and apoptotic inducing agents

A series of chalcone-amidobenzothiazole conjugates (9a-k and 10a,b) have been synthesized and evaluated for their anticancer activity. All these compounds exhibited potent activity and the IC(50) of two potential compounds (9a and 9f) against different cancer cell lines are in the range of 0.85-3.3 μM. Flow cytometric analysis revealed that these compounds induced cell cycle arrest at G2/M phase in A549 cell line leading to caspase-3 dependent apoptotic cell death. The tubulin polymerization assay (IC(50) of 9a is 3.5 μM and 9f is 5.2 μM) and immuofluorescence analysis showed that these compounds effectively inhibit microtubule assembly at both molecular and cellular levels in A549 cells. Further, Annexin staining also suggested that these compounds induced cell death by apoptosis. Moreover, docking experiments have shown that they interact and bind efficiently with tubulin protein. Overall, the current study demonstrates that the synthesis of chalcone-amidobenzothiazole conjugates as promising anticancer agents with potent G2/M arrest and apoptotic-inducing activities via targeting tubulin.     

稀土及其配合物在生物医药上的研究进展

稀土属于化学周期表中镧系元素,具有独特生物活性,能与具有特定生理活性的配体形成稀土配合物。简要归纳了稀土配合物的种类及特点,并阐述了稀土及其配合物在细菌,真菌,癌细胞,正常细胞和病毒方面的生物效应,指出稀土及其配合物在生物医药领域方面有很大的应用前景。     

Intra-cellular storage, transport and exocytosis of halogenated compounds in marine red alga Laurencia obtusa

The production of secondary metabolites in seaweed have been related to a capability to partition compounds into cellular specialized storage structures, like gland cells and the corps en cerise (CC) or cherry bodies. The possible mechanisms that bring these compounds to the thallus surface remain poorly understood. Therefore, the aim of this work is perform a characterization of the CC and determine the intra-cellular dynamics of halogenated compounds in Laurencia obtusa. The dynamics of CC and the mechanisms related to the intra-cellular transport of halogenated compounds were evaluated by using optical tweezers and time-lapse video microscopy. The CC were isolated and its elemental composition was characterized using X-ray microanalysis. The cellular distribution of halogenated compounds was also demonstrated by fluorescence microscopy. Three-dimensional reconstruction technique was used to provide a visualization of the structures that connect CC to cell periphery. As main findings, we confirmed that the halogenated compounds are mainly found in CC and also in vesicles distributed along the cytoplasm and within the chloroplasts. We demonstrated that CC is mechanically fixed to cell periphery by a stalk-like connection. A vesicle transport though membranous tubular connections was seen occurring from CC to cell wall region. We also demonstrated a process of cortical cell death event, resulting in degradation of CC. We suggested that the vesicle transportation along membranous tubular connections and cell death events are related to the mechanisms of halogenated compounds exudation to the thallus surface and consequently with defensive role against herbivores and fouling.