HT-29 Human Colon Carcinoma Cells Research Articles

CF3 Derivatives of the Anticancer Ru(III) Complexes KP1019, NKP-1339, and Their Imidazole and Pyridine Analogues Show Enhanced Lipophilicity, Albumin Interactions, and Cytotoxicity

The Ru(III) complexes indazolium [trans-RuCl4(1H-indazole)2] (KP1019) and sodium [trans-RuCl4(1H-indazole)2] (NKP-1339) are leading candidates for the next generation of metal-based chemotherapeutics. Trifluoromethyl derivatives of these compounds and their imidazole and pyridine analogues were synthesized to probe the effect of ligand lipophilicity on the pharmacological properties of these types of complexes. Addition of CF3 groups also provided a spectroscopic handle for (19)F NMR studies of ligand exchange processes and protein interactions. The lipophilicities of the CF3-functionalized compounds and their unsubstituted parent complexes were quantified by the shake-flask method to give the distribution coefficient D at pH 7.4 (log D7.4). The solution behavior of the CF3-functionalized complexes was characterized in phosphate-buffered saline (PBS) using (19)F NMR, electron paramagnetic resonance (EPR), and UV-vis spectroscopies. These techniques, along with fluorescence competition experiments, were also used to characterize interactions with human serum albumin (HSA). From these studies it was determined that increased lipophilicity correlates with reduced solubility in PBS but enhancement of noncoordinate interactions with hydrophobic domains of HSA. These protein interactions improve the solubility of the complexes and inhibit the formation of oligomeric species. EPR measurements also demonstrated the formation of HSA-coordinated species with longer incubation. (19)F NMR spectra show that the trifluoromethyl complexes release axial ligands in PBS and in the presence of HSA. In vitro testing showed that the most lipophilic complexes had the greatest cytotoxic activity. Addition of CF3 groups enhances the activity of the indazole complex against A549 nonsmall cell lung carcinoma cells. Furthermore, in the case of the pyridine complexes, the parent compound was inactive against the HT-29 human colon carcinoma cell line but showed strong cytotoxicity with CF3 functionalization. Overall, these studies demonstrate that lipophilicity may be a determining factor in the anticancer activity and pharmacological behavior of these types of Ru(III) complexes.

Aspirin prevents colorectal cancer metastasis in mice by splitting the crosstalk between platelets and tumor cells.

We investigated whether platelets prime colon cancer cells for metastasis and whether pharmacological inhibition of platelet function may prevent it. Coculturing HT29 human colon carcinoma cells with human platelets led to the induction of mesenchymal-like cancer cells characterized by downregulation of E-cadherin and upregulation of Twist1, enhanced cell mobility and a proaggregatory action on platelets. These changes were prevented by different antiplatelet agents, aspirin[an inhibitor of cyclooxygenase(COX)-1], DG-041[an antagonist of prostaglandin(PG)E2 EP3 receptor] and ticagrelor (a P2Y12 receptor antagonist). The injection of HT29 cells, exposed to platelets in vitro, into the tail vein of humanized immunodeficient mice led to higher incidence of lung metastasis compared to the injection of untreated HT29 cells. This effect was associated with enhanced systemic biosynthesis of thromboxane(TX)A2 and PGE2 in vivo. Platelet COX-1 inhibition by aspirin administration to mice prevented the increased rate of metastasis as well as the enhanced production of TXA2 and PGE2 induced by the in vitro priming of HT29 cells by platelets. In conclusion, targeting platelet COX-1 with low-dose aspirin exerts an antimetastatic action by averting the stem cell mimicry of cancer cells associated with enhanced proaggregatory effects induced by platelet-tumor cell interactions. These effects may be shared by other antiplatelet drugs.

Translocator Protein-Mediated Stabilization of Mitochondrial Architecture during Inflammation Stress in Colonic Cells.

Chronic inflammation of the gastrointestinal tract increasing the risk of cancer has been described to be linked to the high expression of the mitochondrial translocator protein (18 kDa; TSPO). Accordingly, TSPO drug ligands have been shown to regulate cytokine production and to improve tissue reconstruction. We used HT-29 human colon carcinoma cells to evaluate the role of TSPO and its drug ligands in tumor necrosis factor (TNF)-induced inflammation. TNF-induced interleukin (IL)-8 expression, coupled to reactive oxygen species (ROS) production, was followed by TSPO overexpression. TNF also destabilized mitochondrial ultrastructure, inducing cell death by apoptosis. Treatment with the TSPO drug ligand PK 11195 maintained the mitochondrial ultrastructure, reducing IL-8 and ROS production and cell death. TSPO silencing and overexpression studies demonstrated that the presence of TSPO is essential to control IL-8 and ROS production, so as to maintain mitochondrial ultrastructure and to prevent cell death. Taken together, our data indicate that inflammation results in the disruption of mitochondrial complexes containing TSPO, leading to cell death and epithelia disruption. Significance: This work implicates TSPO in the maintenance of mitochondrial membrane integrity and in the control of mitochondrial ROS production, ultimately favoring tissue regeneration.

Facile preparation of multifunctional superparamagnetic PHBV microspheres containing SPIONs for biomedical applications.

The promising potential of magnetic polymer microspheres in various biomedical applications has been frequently reported. However, the surface hydrophilicity of superparamagnetic iron oxide nanoparticles (SPIONs) usually leads to poor or even failed encapsulation of SPIONs in hydrophobic polymer microspheres using the emulsion method. In this study, the stability of SPIONs in poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) solution was significantly increased after surface modification with lauric acid. As a result, magnetic PHBV microspheres with high encapsulation efficiencies (71.0–87.4%) were prepared using emulsion-solvent extraction/evaporation method. Magnetic resonance imaging (MRI) showed significant contrast for the magnetic PHBV microspheres. The toxicity of these magnetic PHBV microspheres towards human T-lymphoma suspension cells and adherent colon carcinoma HT-29 cells was investigated using flow cytometry, and they were shown to be non-toxic in a broad concentration range. A model drug, tetracycline hydrochloride, was used to demonstrate the drug delivery capability and to investigate the drug release behavior of the magnetic PHBV microspheres. The drug was successfully loaded into the microspheres using lauric acid-coated SPIONs as drug carrier, and was released from the microspheres in a diffusion controlled manner. The developed magnetic PHBV microspheres are promising candidates for biomedical applications such as targeted drug delivery and MRI.

The effects of formulation and serum albumin on the in vitro photodynamic activity of zinc(II) phthalocyanines substituted with sulfonated quinolineoxy groups

Three zinc(II) phthalocyanines substituted with sulfonated quinolineoxy groups, including the mono-α-substituted 1, tetra-α-substituted 3, and tetra-β-substituted 4 were synthesized and characterized. These compounds (in deprotonated form) were water-soluble and could be formulated with Cremophor EL or phosphate buffered saline. When formulated with phosphate buffered saline, the serum albumin exerted an important effect on the aggregation tendency and spectroscopic properties of these compounds in biological media. In the case of phosphate buffered saline formulation, the photocytotoxicity followed the order 3 > 4 >> 1 for both human colon carcinoma HT29 and human hepatocarcinoma HepG2 cell lines as a result of their different aggregation tendency. Interestingly, when formulated with Cremophor EL, 1 showed the highest photocytotoxicity not only due to its highest cellular uptake but also due to the reduced aggregation. In both of these formulated systems, the tetra-α-substituted compound 3 exhibited a higher potency than the tetra-β-substituted analogue 4.

Abstract B018: Developmental and functional characterization of immunoglobulin kappa chain-bridged single chain bi-specific antibody for targeted antitumor therapy

Abstract The immune system has routinely been the focus of cancer treatments. One of the strategies that targets the immune system is by use of monoclonal antibodies to specifically target tumor antigens leading to immune activation and tumor destruction. Therefore, many biopharmaceutical companies are interested/invested in antibody development, including the development of next-generation antibodies such as bispecific antibodies. The Development Center for Biotechnology (DCB) in Taiwan has developed a new platform for the generation of immunoglobulin kappa chain-bridged single chain bispecific antibody. Using this platform, DCB constructed a kappa domain-bridged HER2/CD3 bispecific single chain antibody known as the LBscbHER2-CD3. Utilizing a mammalian expression system, the antibody can be easily purified by affinity chromatography via kappa fragment capture. Binding affinity studies have revealed that the purified LBscbHER2-CD3 antibody is able to independently as well as simultaneously bind to HER2+ tumor cells and CD3+ T cells at low nanomolar concentrations. In co-culture experiments, the addition of purified LBscbHER2-CD3 antibody resulted in a significant increase in IL-2 production which is a strong indicator of human T cell activation. In addition, the co-engagement of either IL-2 primed or un-primed human T cells and HER2+ tumor cells by the LBscbHER2-CD3 antibody facilitated the killing of tumor cells from breast, colon and pancreatic cancers. Lastly, when administered in vivo, LBscbHER2-CD3 showed strong tumor growth inhibition in SCID mice xenograft models with implanted HER2+ SW480 cancer cells, HT29 human colon carcinoma cells, and Capan-1 human pancreatic cancer cells. In conclusion, the LBscbHER2-CD3 bispecific antibody has strong affinity for both the cancer cell-expressing receptor and the T cell antigen which leads to cancer cell elimination in vitro and in vivo. These results suggest that LBscbHER2-CD3 may have therapeutic potential for drug development in the treatment of human cancers. Citation Format: Yu Hsun Lo, Jei-Hwa Yu, Yu-Hsen Hsui, Ta-Tung Yuan. Developmental and functional characterization of immunoglobulin kappa chain-bridged single chain bi-specific antibody for targeted antitumor therapy. [abstract]. In: Proceedings of the CRI-CIMT-EATI-AACR Inaugural International Cancer Immunotherapy Conference: Translating Science into Survival; September 16-19, 2015; New York, NY. Philadelphia (PA): AACR; Cancer Immunol Res 2016;4(1 Suppl):Abstract nr B018.

Abstract C113: The monocarboxylate transporter 1 (MCT1) inhibitor AZD3965 triggers MCT4-dependent lactate accumulation and blocks pyruvate-lactate exchange in human cancer cells

Abstract Background: Monocarboxylate transporters (MCTs) are key modulators of lactate homeostasis and represent promising metabolic targets for molecular cancer therapeutics. The MCT1 inhibitor AZD3965 is now in clinical trial and understanding the impact of this drug on tumour cell metabolism may enable the discovery of pharmacodynamic (PD) biomarkers of target inhibition that will support the clinical development of such agents. Since MCT1 mediates the bidirectional transport of lactate and other monocarboxylates including pyruvate, here we use NMR spectroscopy to investigate the effect of AZD3965 on a) intracellular lactate levels and b) hyperpolarized 13C-pyruvate-lactate exchange, as biomarkers for MCT1 inhibition in human cancer cells with varying MCT4 expression (predictive of resistance to AZD3965). Materials and Methods: Human Raji (MCT4-) and Hut78 (MCT4 low (+)) lymphoma as well as HT29 (MCT4 high (+++)) colon carcinoma cells were treated with either 5nM or 500nM AZD3965 for 24h and levels of intracellular lactate determined by 1H NMR of cell extracts. Raji cells were also exposed to additional AZD3965 concentrations spanning 1nM-500nM. For 13C-pyruvate-lactate exchange studies, Raji cells were treated with either 5nM or 25nM AZD3965 for 24h. Cells were then incubated at 37°C in FBS-free medium and dynamic 13C NMR spectra acquired for 4 minutes with 2s intervals immediately after the addition of 10mM hyperpolarised [1-13C]pyruvic acid and 10mM unlabelled lactate. The ratio of the area under the curve for the summed lactate and pyruvate signals (LacAUC/PyrAUC) was determined to estimate pyruvate-lactate exchange. Data represent mean±SE. Results: 24h exposure to a low concentration of AZD3965 (5nM) led to increased intracellular lactate in MCT4- Raji and MCT4+ Hut78 human lymphoma cells to 2.65-fold and 10-fold respectively (p = ≤0.02) while the effect in MCT4+++ HT29 human colon carcinoma cells was insignificant (167±31% of controls, p = 0.1). Exposure to a high concentration of AZD3965 (500nM) increased intracellular lactate accumulation in HT29 cells albeit to a lesser degree than in Raji and Hut78 cells (4-fold (0.02) vs. 14 to 15-fold (p≤0.01) in the lymphoma lines). This effect is consistent with the expected blockade of lactate release in cells with low or no MCT4 expression following MCT1 inhibition. Lactate build-up in Raji cells was AZD3965 concentration-dependent being observed with as little as 1nM (up 1.7-fold), reaching a maximum at 25nM (12-fold) and plateauing thereafter. Analysis of the hyperpolarized 13C NMR data showed a significant decrease in LacAUC/PyrAUC to 31±6% in 5nM and 19±2% in 25nM AZD3965-treated Raji cells relative to controls (p<0.001). These results are consistent with MCT1-mediated transport of 13C-pyruvate being a rate limiting step in the 13C NMR-observed pyruvate-lactate exchange. Conclusions: Our data show that AZD3965 triggers intracellular lactate accumulation in a concentration- and MCT4 expression-dependent manner and inhibits 13C-pyruvate-lactate exchange (via blockade of 13C-pyruvate uptake). Intracellular lactate and hyperpolarized 13C-pyruvate-lactate exchange measurements are translatable to in vivo imaging studies and are therefore promising non-invasive metabolic biomarkers for AZD3965 and potentially other MCT1 inhibitors. Citation Format: Mounia Beloueche-Babari, Slawomir Wantuch, Markella Koniordou, Harry G. Parkes, Vaitha Arunan, Thomas R. Eykyn, Paul D. Smith, Martin O. Leach. The monocarboxylate transporter 1 (MCT1) inhibitor AZD3965 triggers MCT4-dependent lactate accumulation and blocks pyruvate-lactate exchange in human cancer cells. [abstract]. In: Proceedings of the AACR-NCI-EORTC International Conference: Molecular Targets and Cancer Therapeutics; 2015 Nov 5-9; Boston, MA. Philadelphia (PA): AACR; Mol Cancer Ther 2015;14(12 Suppl 2):Abstract nr C113.

Cytotoxicity and Structural Analyses of 2,2′‐Bipyridine‐, 4,4′‐Dimethyl‐2,2′‐bipyr­idine‐ and 2‐(2′‐Pyridyl)quinoxalineplatinum(II) Complexes

AbstractInvited for the cover of this issue is the group of Janice Aldrich‐Wright at the University of Western Sydney, Australia. The cover image shows X‐ray crystal structures and CD spectra of platinum(II) complexes of 4,4'‐dimethyl‐2,2'‐bipyridine and 2‐(2'‐pyridyl)quinoxaline against a background of fluorescently stained HT29 human colon carcinoma cells. The Southern Cross refers to the country of origin of this work.

Scutellaria barbata D. Don inhibits growth and induces apoptosis by suppressing IL-6-inducible STAT3 pathway activation in human colorectal cancer cells.

One of the most critical cellular signal transduction pathways known to malfunction in colorectal cancer is the interleukin-6/signal transducer and activator of transcription 3 (IL-6/STAT3) pathway. Scutellaria barbata D. Don (SB) is well-known traditional medicine in China that targets STAT3 signaling, and it has long been used to treat various types of cancer; however, the precise mechanism of its antitumor activity remains largely unclear. In order to further elucidate this underlying mechanism, an ethanol extract of SB (EESB) in cancer treatment. The aim of the present study was to evaluate the effects of EESB on the IL-6-inducible STAT3 pathway. We tested the dose-response association between EESB, IL-6-induced proliferaion and apoptosis using an MTT assay, colony formation and flow cytometry analysis in vitro. In addition, caspase-9 and caspase-3 activation was determined using a colorimetric assay, the activity of IL-6-induced STAT3 pathway was evaluated using western blot analysis, and the expression levels of cyclin D1, cyclin-dependent kinase 4, Bcl2 and Bcl2-associated X were determined using reverse transcription-polymerase chain reaction and western blot analysis. In the present study it was found that EESB could significantly inhibit the IL-6-mediated increase in STAT3 phosphorylation levels and transcriptional activity in HT-29 human colon carcinoma cells, resulting in the suppression of cell proliferation and the induction of apoptosis. In addition, treatment with EESB markedly inhibited the IL-6-induced upregulation of cyclin D1 and B-cell lymphoma-2, two key target genes of the STAT3 pathway. These results suggest that treatment with EESB could effectively inhibit the proliferation and promote the apoptosis of human colon carcinoma cells via modulation of the IL-6/STAT3 signaling pathway and its target genes.

Cytotoxicity and Structural Analyses of 2,2′‐Bipyridine‐, 4,4′‐Dimethyl‐2,2′‐bipyr­idine‐ and 2‐(2′‐Pyridyl)quinoxalineplatinum(II) Complexes

AbstractPlatinum anticancer complexes incorporating 2,2′‐bipyridine (bpy), 4,4′‐dimethyl‐2,2′‐bipyridine (44Me2bpy) or 2‐(2′‐pyridyl)quinoxaline (2pq) as polyaromatic ligands and the S,S or R,R isomer of 1,2‐diaminocyclohexane as ancillary ligands in the form [Pt(PL)(AL)]2+ have been synthesised and characterised. X‐ray diffraction was used to elucidate the structure and stacking behaviour of the complexes, revealing interesting properties that may impact their biological activity. Pulsed gradient spin‐echo NMR experiments elucidated the aggregation behaviour of these complexes in solution. The cytotoxicity of each complex was assessed against the L1210 murine leukaemia, HT29 human colon carcinoma and U87 human glioblastoma cell lines and compared to other complexes within this class. The complexes incorporating 44Me2bpy were found to be the most potent at inhibiting cell growth with IC50 values for the S,S isomer (0.13–0.5 μM) less than that for cisplatin (0.36–11 μM), oxaliplatin (0.9–1.8 μM) or carboplatin (>50 μM). Most complexes were found to be very effective against HT29 colon carcinoma cells.

Polyphenolic Metabolites from Iris pseudacorus Roots

Five known isoflavonoids (6–8, 11, 16), one flavonoid (14), four hydroxybenzoic acids (1–4), and a new 7-O-β-D-glucopyranoside of 5,7-dihydroxy-2′,6-dimethoxyisoflavone (5) were isolated from Iris pseudacorus roots and identified. The polyphenol contents in stems and roots of this plant were determined. The effect of 6, 8, 9, 11, 15, and 16 on the growth of colonies of HT-29 human colon carcinoma cells was studied. It was shown that trans-3-hydroxy-5,7-dimethoxyflavanone (9) exhibited pronounced inhibition of tumor-cell colony formation at a dose of 25 μM.

Restoration of the anti-proliferative and anti-migratory effects of 1,25-dihydroxyvitamin D by silibinin in vitamin D-resistant colon cancer cells

Colorectal carcinoma (CRC) is the third most common cancer in developed countries. A large fraction of cases are linked to chronic intestinal inflammation, with concomitant increased TNF-α release and elevated Snail1/Snail2 levels. These transcription factors in turn suppress vitamin D receptor (VDR) expression, resulting in loss of responsiveness to the protective anti-proliferative and anti-migratory effects of 1,25-dihydroxyvitamin D (1,25D). Experimental and epidemiologic evidence support the use of natural products to target CRC. Here we show that the flavonolignan silibinin reverses the TNF-α-induced upregulation of Snail1 and Snail2 in the 1,25D-resistant human colon carcinoma cells HT-29. These silibinin effects are accompanied by an increase in VDR levels; Snail1 overexpression reverses these silibinin effects. Silibinin also restores promoter activity from a vitamin D-response element (VDRE) reporter construct. While 1,25D had no significant effect on HT-29 and SW480-R cell proliferation and migration, co-treatment with silibinin restored 1,25D responsiveness. In addition, co-treatment with silibinin plus 1,25D decreased proliferation and migration at doses where silibinin alone had no effect. These findings demonstrate that this combination may present a novel approach to target CRC in conditions of chronic colonic inflammation.

Anticancer effects of kimchi fermented for different times and with added ingredients in human HT-29 colon cancer cells

Anticancer effects of kimchi fermented for different times and containing added ingredients in HT-29 human colon carcinoma cells were studied. Optimally ripened kimchi showed higher anti-proliferation activities than fresh and over-ripened kimchi. Anticancer-ingredients-added kimchi exhibited higher activities than standardized-recipe kimchi in HT-29 cells. Optimally-ripened anticancer kimchi suppressed expression of Bcl-2 and promoted expression of Bax, caspase-9, and caspase-3 to promote apoptosis, and reduced mRNA expressions of proinflammatory factors, exhibiting the strongest anticancer effect. Fermentation and ingredients are important factors to increase in vitro anticancer functionalities.

Inhibitory effects of proton beam irradiation on integrin expression and signaling pathway in human colon carcinoma HT29 cells.

Proton radiotherapy has been established as a highly effective modality used in the local control of tumor growth. Although proton radiotherapy is used worldwide to treat several types of cancer clinically with great success due to superior targeting and energy deposition, the detailed regulatory mechanisms underlying the functions of proton radiation are not yet well understood. Accordingly, in the present study, to assess the effects of proton beam on integrin-mediated signaling pathways, we investigated the expression of integrins related to tumor progression and integrin trafficking, and key molecules related to cell adhesion, as well as examining phosphorylation of signaling molecules involved in integrin-mediated signaling pathways. Proton beam irradiation inhibited the increase in 12-O-tetradecanoylphorbol-13-acetate (TPA)-induced integrin β1 protein expression and the gene expression of members of the integrin family, such as α5β1, α6β4, αvβ3, and αvβ6 in human colorectal adenocarcinoma HT-29 cells. Simultaneously, the gene expression of cell adhesion molecules, such as FAK and CDH1, and integrin trafficking regulators, such as RAB4, RAB11, and HAX1, was decreased by proton beam irradiation. Moreover, proton beam irradiation decreased the phosphorylation of key molecules involved in integrin signaling, such as FAK, Src, and p130Cas, as well as PKC and MAPK, which are known as promoters of cell migration, while increased the phosphorylation of AMPK and the gene expression of Rab IP4 involved in the inhibition of cell adhesion and cell spreading. Taken together, our findings suggest that proton beam irradiation can inhibit metastatic potential, including cell adhesion and migration, by modulating the gene expression of molecules involved in integrin trafficking and integrin-mediated signaling, which are necessary for tumor progression.

Synthesis, characterization and biological studies of diorganotin(IV) complexes with tris[(hydroxymethyl)aminomethane] Schiff bases

Several Schiff base ligands derived from tris(hydroxymethyl)aminomethane were synthesized and a series of diorganotin(IV) complexes were obtained from the reaction of diorganotin dichlorides or oxides with Schiff base ligands. The ligands and complexes have been characterized by elemental analysis, IR, 1H, 13C and 119Sn NMR spectroscopies. Single-crystal X-ray diffraction analysis reveals that bis[(2-{[1,1-bis(hydroxymethyl)-2-oxidoethyl]iminomethyl}phenolato)]dimethyltin(IV), 1 and bis[(2-{[1,1-bis(hydroxymethyl)-2-oxidoethyl]iminomethyl}-4-bromophenolato)]dimethyltin(IV), 7 are dimeric structures, in which the central tin atom is rendered six-coordinate while (2-{[1,1-bis(hydroxymethyl)-2-oxidoethyl]iminomethyl}-4-bromophenolato)diphenyltin(IV), 9, (2-{[1,1-bis(hydroxymethyl)-2-oxidoethyl]iminomethyl}-4-chlorophenolato)dimethyltin(IV), 13, (2-{[1,1-bis(hydroxymethyl)-2-oxidoethyl]iminomethyl}-4-chlorophenolato)diphenyltin(IV), 15 and (2-{[1,1-bis(hydroxymethyl)-2-oxidoethyl]iminomethyl}-4-chlorophenolato)dicyclohexyltin(IV), 16 are monomeric structures, whereby the tin atom is in a distorted trigonal–bipyramidal configuration. The Schiff bases and their corresponding diorganotin(IV) complexes have been evaluated against three human carcinoma cell lines, namely HT29 (human colon carcinoma cell line), SKOV-3 (human ovarian cancer cell line) and MCF-7 (hormone-dependent breast carcinoma cell line), for its in vitro cytotoxic activities. The dibutyltin and dicyclohexyltin derivatives of the Schiff base ligands display good cytotoxic activities against the tested cell lines.

In vitro antiproliferative/cytotoxic activity of 2,3ʹ-biindole againstvarious cancer cell lines

2,3'-Biindole (2) was synthesized via bromination of indole (1) with molecular bromine and underwent simultaneous dimerization. Antiproliferative and cytotoxic activity of 2 was investigated in vitro on C6 (rat brain tumor), HeLa (human cervix carcinoma), and HT29 (human colon carcinoma) cells lines by using BrdU cell proliferation ELISA and lactate dehydrogenase (LDH) assays. In contrast to 5-fluorouracil (5-FU), 2,3'-biindole (2) significantly inhibited proliferation of HeLa and HT29 cell lines. According to LDH assay, the cytotoxicity of compound 2 was low on HT29 cell lines and high on HeLa and C6 cell lines. Moreover, 2 did not cause any DNA laddering on the DNA of tested cells; therefore, it is suggested that the mechanism of action of this compound may not involve apoptosis. In addition, 2 inhibited relaxation of supercoiled plasmid DNA by topoisomerase activity. Results of the present study indicates that biindole (2) may have promising anticancer and antitopoisomerase potential with an unknown mechanism of action.

Melissa officinalis extract induces apoptosis and inhibits proliferation in colon cancer cells through formation of reactive oxygen species

PurposeEfficient strategies for the prevention of colon cancer are extensively being explored, including dietary intervention and the development of novel phytopharmaceuticals. Safe extracts of edible plants contain structurally diverse molecules that can effectively interfere with multi-factorial diseases such as colon cancer. In this study, we describe the antiproliferative and proapoptotic effects of ethanolic lemon balm (Melissa officinalis) leaves extract in human colon carcinoma cells. We further investigated the role of extra- and intracellular reactive oxygen species (ROS). MethodsAntitumor effects of lemon balm extract (LBE) were investigated in HT-29 and T84 human colon carcinoma cells. Inhibition of proliferation was analyzed by DNA quantification. The causal cell cycle arrest was determined by flow cytometry of propidium iodide-stained cells and by immunoblotting of cell cycle regulator proteins. To investigate apoptosis, cleavage of caspases 3 and 7 was detected by immunoblotting and fluorescence microscopy. Phosphatidylserine externalization was measured by Annexin V assays. Mechanistic insights were gained by measurement of ROS using the indicator dyes CM-H2DCFDA and Cell ROX Green. ResultsAfter 3 and 4 days of treatment, LBE inhibited the proliferation of HT-29 and T84 colon carcinoma cells with an inhibitory concentration (IC50) of 346 and 120 µg/ml, respectively. Antiproliferative effects were associated with a G2/M cell cycle arrest and reduced protein expression of cyclin dependent kinases (CDK) 2, 4, 6, cyclin D3, and induced expression of cyclin-dependent kinase inhibitor 2C (p18) and 1A (p21). LBE (600 µg/ml) induced cleavage of caspases 3 and 7 and phosphatidylserine externalization. LBE-induced apoptosis was further associated with formation of ROS, whereas quenching of ROS by antioxidants completely rescued the colon carcinoma cells from LBE-induced apoptosis. ConclusionsLemon balm (Melissa officinalis) extract inhibits the proliferation of colon carcinoma cells and induces apoptosis through formation of ROS. Taken together, LBE or subfractions thereof could be used for the prevention of colon cancer.

고추장 제조시 발효가 항돌연변이 및 in vitro 항암효과에 미치는 영향

Increased antimutagenic and in vitro anticancer effects were observed by the fermentation process during Kochujang manufacturing. In order to confirm the increased functionality, wheat grain, first fermented wheat grains (FFWG), second fermented wheat grains (SFWG), final fermented wheat grains (FiFWG), red pepper powder (RPP), and commercial Kochujang (CK) were prepared. Kochujang manufactured with final fermented wheat grains and red pepper powder were further fermented for 15 days and 30 days. The antimutagenic effects were determined by counting the number of revertants in Salmonella Typhimurium TA100 against N-methyl-N'-nitro-nitrosoguanidine (MNNG, 1.0mg/mL). The final fermented wheat grains (52% inhibition) showed higher antimutagenic effects than the wheat grain (34%), and the commercial Kochujang showed the highest antimutagenic effects (55%). We tested the inhibitory effect on the growth of HT-29 human colon carcinoma cells and AGS human gastric adenocarcinoma cells by using MTT (3-(4,5-dimethyl-thiazol)-2,5-diphenyltetrazolium bromide) assay. The results showed that increased fermentation process continually increased the growth inhibitory effect on both cancer cells. The further fermentation for 15 days of the Kochujang product also increased inhibitory growth of the AGS cancer cells. In conclusion, the methanol extract from fermented wheat grains and commercial Kochujang showed sequentially increased antimutagenic and in vitro anticancer activity, and thus the final commercial Kochujang revealed the highest effect.

Metallocene-uracil conjugates: Synthesis and biological evaluation of novel mono-, di- and tri-nuclear systems

The chemistry and biology of metallocene-nucleobase conjugates has been recognized as an increasingly important area of bioorganometallic chemistry. In this study, we have developed a two-step synthetic route to prepare mono-, di-, and tri-nuclear metallocene-uracil derivatives. Our synthetic procedure uses the Sonogashira cross-coupling and the PEMB-mediated reduction reactions as key steps. Successful application of PEMB as a mild and selective reducing agent allowed us to obtain with high yields a series of metallocenethymines bearing saturated linker groups. The compounds have been characterized by spectroscopic methods and the molecular structures of [3-(N1-(5iodouracilyl)propionyl]ferrocene (18) and [3-(N1-(5-iodouracilyl)propionyl]ruthenocene (19) were determined by X-ray diffraction. The anticancer activity of the metallocene-nucleobase products has been tested against estrogen receptor negative MDA-MB-231 mammary carcinoma, human HT-29 colon carcinoma and non-tumor mouse L929 fibroblast cells. This study has emphasized the cytotoxic activity of [3-(N1-(5-ferrocenylethynyl)propionyl]ferrocene (7) and [3-(N1-(5-methyluracilyl)propyl]-1′-diferocenylmethane (12). Notably, compound 12 was more cytotoxic against HT-29 cells than cisplatin. Moreover the undesired cytotoxicity of 12 against healthy L929 fibroblast cells was at the same level as cisplatin. Our results confirm the importance of dinuclear organometallic systems as anticancer agents.

Transition metal complexes of α-aminophosphonates Part I: synthesis, spectroscopic characterization, and in vitro anticancer activity of copper(II) complexes of α-aminophosphonates

New generation of copper(II) complexes with α-aminophosphonate as tridentate ligands has been synthesized. It is characterized by elemental analyses, spectral (IR, UV–Vis, MS, EPR, and 1H NMR) studies, thermal analysis as well as magnetic and molar conductance measurements. On the basis of spectral studies, a distorted square planar geometry has been assigned for all the complexes. Specific rotation measurements for both ligands and copper(II) complexes showed that they are enantiomerically enriched. The metal-free ligands and their Cu(II) complexes were tested for their in vitro anticancer activity against human colon carcinoma HT-29 cell lines. The results showed that the synthesized copper(II) complexes exhibited significantly higher anticancer activity than their free ligands. Among all the tested compounds in the series, the complex 5g demonstrated the highest anticancer activity at low micromolar inhibitory concentrations (IC50 = 14.2 µM) which is about a half of the reference drug activity, cisplatin (IC50 = 7.0 µM) in the same assay.