Human Oral Epidermoid Carcinoma Cells Research Articles

Design, synthesis and anticancer activity studies of 3-(coumarin-3-yl)-acrolein derivatives: Evidenced by integrating network pharmacology and vitro assay.

Coumarin derivatives have diverse structures and show various significant biological activities. Aiming to develop more potent coumarin derivatives for cancer treatment, a series of coumarin acrolein hybrids were designed and synthesized by using molecular hybridization approach, and investigated for their antiproliferative activity against A549, KB, Hela and MCF-7 cancer cells as well as HUVEC and LO2 human normal cells. The results indicated that most of the synthesized compounds displayed remarkable inhibitory activity towards cancer cells but low cytotoxicity on normal cells. Among all the compounds, 5d and 6e were the most promising compounds against different cancer cell lines, especially for A549 and KB cells. The preliminary action mechanism studies suggested that compound 6e, the representative compound, was capable of dose-dependently suppressing migration, invasion and inducing significant apoptosis. Furthermore, the combined results of network pharmacology and validation experiments revealed that compound 6e induced mitochondria dependent apoptosis via the PI3K/AKT-mediated Bcl-2 signaling pathway. In summary, our study indicated compound 6e could inhibit cell proliferation, migration, invasion and promote cell apoptosis through inhibition of PI3K/AKT signaling pathway in human oral epidermoid carcinoma cells. These findings demonstrated the potential of 3-(coumarin-3-yl)-acrolein derivatives as novel anticancer chemotherapeutic candidates, providing ideas for further development of drugs for clinical use.

BMP4 Regulates EMT to be Involved in non-Syndromic Cleft lip With or Without Palate.

In the previous study, we identified bone morphogenetic protein 4 (BMP4) responsible for non-syndromic cleft lip with or without cleft palate (NSCL/P). We aimed to elucidate the effects and mechanisms of BMP4 on epithelial-mesenchymal transition (EMT) through Smad1 signaling pathway to be involved in NSCL/P. The human oral epidermoid carcinoma cells (KBs) were transfected with plasmids or small interfering RNA (siRNA) to build the models. The migration of the cells was evaluated by transwell assay. Western blotting and quantitative real-time reverse transcription-polymerase chain reaction (qRT-PCR) were used to detect the expressions of BMP4, E-cadherin, N-cadherin, EMT-related transcription factors snal1 and snal2, matrix metalloproteinase 2 (MMP2), MMP9, Smad1, and phosphorylated Smad1. In the overexpression group, the migration number of cells was increased significantly. The protein expression of E-cadherin was decreased significantly, while the protein expression level of the N-cadherin was increased significantly. The protein and mRNA expressions of MMP2, MMP9, snal1, and snal2 were significantly higher. The expression level of Smad1 was not significantly changed, while the phosphorylation of Smad1 was significantly increased. In the BMP4-siRNA group, the migrating number cells was significantly decreased. The protein expression of E-cadherin was increased significantly, while the expression of N-cadherin was significantly decreased. The protein and mRNA expressions of MMP2, MMP9, snal1, and snal2 were significantly lower than that of the control group. The expressions of Smad1 and phosphorylation of Smad1 were not significantly changed. BMP4 enhances cell migration and promotes cell EMT through Smad1 signaling pathway. Abnormal BMP4 mediates migration and EMT through other relevant signaling pathways resulting in NSCL/P. The study provides new insight into the mechanisms of NSCL/P associated with BMP4.n.

Real-Time Monitoring the Cytotoxic Effect of Andrographolide on Human Oral Epidermoid Carcinoma Cells.

Andrographolide is an active diterpenoid compound extracted from Andrographis paniculata. It exhibits antiinflammatory and anticancer effects. Previous studies show that it is non-toxic to experimental animals. The leading causes of cancer are chronic inflammation and high blood glucose. This study determines the cytotoxic effect of andrographolide on cellular morphology, viability, and migration for human oral epidermoid carcinoma cell Meng-1 (OEC-M1). We use electric cell-substrate impedance sensing (ECIS) to measure the subsequent overall impedance changes of the cell monolayer in response to different concentrations of andrographolide for 24 h (10–100 µM). The results for exposure of OEC-M1 cells to andrographolide (10–100 µM) for 24 h show a concentration-dependent decrease in the overall measured resistance at 4 kHz. AlamarBlue cell viability assay and annexin V also show the apoptotic effect of andrographolide on OEC-M1 cells. A reduction in wound-healing recovery rate is observed for cells treated with 30 μM andrographolide. This study demonstrates that ECIS can be used for the in vitro screening of anticancer drugs. ECIS detects the cytotoxic effect of drugs earlier than traditional biochemical assays, and it is more sensitive and shows more detail.

Cytotoxic and antibacterial depsidones from the endophytic fungus Chaetomium brasiliense isolated from Thai rice

Four new depsidones, mollicellins V-Y (1-4), together with eight known depsidones (5-12) were isolated from the endophytic fungus, Chaetomium brasiliense, detached from stems of Thai rice. Their structures were determined by extensive spectroscopic methods. Mollicellins X, H, and F (3, 8 and 10) showed potent cytotoxicity against the human oral epidermoid carcinoma (KB) cell line, and mollicellin F (10) also showed a potent cytotoxicity against the human hepatocellular carcinoma (HepG2) cell line. Besides, mollicellin B (11) exhibited cytotoxicity against the colorectal adenocarcinoma (HT-29) cell line. Moreover, most of the isolated depsidones displayed potent antibacterial activity against Gram-positive bacteria, Bacillus cereus and Bacillus subtilis, and several of them showed moderate activity against Methicillin-resistant Staphylococcus aureus (MRSA) and clinical isolates of S. aureus. In addition, a few of them also showed moderate activity against a Gram-negative bacteria Pseudomonas aeruginosa.

Synthesis, biological evaluation, and correlation of cytotoxicity versus redox potential of 1,4-naphthoquinone derivatives

A series of 1,4-naphthoquinone derivatives of lawsone (1), 6-hydroxy-1,4-naphthoquinone (2), and juglone (3) were synthesized by alkylation, acylation, and sulfonylation reactions. The yields of lawsone derivatives 1a-1k (type A), 6-hydroxy-1,4-naphthoquinone derivatives 2a-2j (type B), and juglone derivatives 3a-3h (type C) were 52–99%, 53–96%, and 28–95%, respectively. All compounds were tested in vitro for the cytotoxicity against human oral epidermoid carcinoma (KB) and cervix epithelioid carcinoma (HeLa) cells and their structure–activity relationship was studied. Compound 3c was found to be most potent in KB cell line (IC50 = 1.39 µM). Some compounds were evaluated for DNA topoisomerase I inhibition. Compounds 2c, 3, 3a, and 3d showed topoisomerase inhibition activity with IC50 values of 8.3–91 µM. Standard redox potentials (E°) of all naphthoquinones in phosphate buffer at pH 7.2 were examined by means of cyclic voltammetry. A definite correlation has been found between the redox potentials and inhibitory effects of type A compounds.

The Role of miR-143, miR-145, and miR-590 in Expression Levels of CD44 and Vascular Endothelial Cadherin in Oral Squamous Cell Carcinoma

Background: Oral squamous cell carcinoma (OSCC) is the most common head and neck cancer with a continuing rise of incidence in developing countries. Despite the improvement in the clinical outcome of OSCC, the overall 5-year survival rate of patients is still disappointing. MicroRNAs (miRNAs) regulate gene expression in the post-transcriptional stage by targeting mRNAs. Advances in knowledge of the pathogenesis and molecular events lead to the improvement of OSCC treatments. Materials and Methods: Human oral epidermoid carcinoma cells (KB), HGF1, and HEK 293T cell line were cultured. Lentiviral vectors were constructed and Western Blot analysis was performed. Then, immunocytochemistry staining was performed by using CD44 and vascular endothelial cadherin (VE-Cadherin) antibodies. All data were analyzed using the REST 2009 software. P values of ≤0.05 were considered statistically significant. Results: MiR-143, miR-145, and miR 590 were down-regulated in the oral cancer cell line. Following transfection of Lv miR 143, Lv-miR-145, and Lv-miR-590, the expression of CD44 was markedly decreased in KB cells. In addition, transfection of miR-143 and miR- 590 mimics into the oral cancer cell line significantly decreased the expresion level of VE-Cadherin; however, transfection of miR-145 mimic had no significant effect on the expression of VE-Cadherin. Western blot analysis and immunocytochemistry staining confirmed the results. Conclusion: This study revealed that miR-143, miR-145, and miR-590 negatively regulate CD44 and VE-Cadherin (except miR-145) expression, which might play a crucial role in the induction of cancer stem cells proliferation and angiogenesis in OSCC cells. The knowledge about the involved factors may provide new insights for the clinical use of miR- 143, mR-145, and miR-590 in the treatment of patients with OSCC.

Tumor-targeted biodegradable multifunctional nanoparticles for cancer theranostics

Mesoporous silica nanoparticles (MSN) attract extensive attention in area of cancer diagnosis and therapy because of their controllable nanostructures, easy surface modification and stable synthesis methods. However, their biodegradability was still controversial. This work explored the degradation effect of a type of biodegradable MSN (bMSN) in different environments and simultaneously endowed it with imaging functions and high-efficiency targeting effect on cancer cell, thus forming a multifunctional biodegradable drug carrier (bMSN-ss-GABA) for cancer theranostics. The bovine serum albumin-based Gd/Au complex (BSA-Gd/Au) was wrapped on the surface of bMSN through disulfide linkage, acting as contrast agent for magnetic resonance (MR) and fluorescence imaging, and then folate (FA), whose receptor (FR) is overexpressed in KB human oral epidermoid carcinoma cells, was modified on the nanocarriers as a targeting ligand. TEM revealed the degradation process of bMSN and a series of characterization methods verified the successful construction of bMSN-ss-GABA. Doxorubicin hydrochloride (DOX) loaded bMSN-ss-GABA (DOX@bMSN-ss-GABA) was proved with redox-responsiveness, thereby triggering rapid drug release under specific tumor microenvironment of high glutathione concentration. Further, the excellent imaging capability was also fully inspected. What’s more, the results of endocytosis and tumor growth inhibition of DOX@bMSN-ss-GABA demonstrated the highly effective targeting effect of hybird nanocarriers. Therefore, the prepared DOX@bMSN-ss-GABA might be used as a promising nanotheranostic agent for KB human oral epidermoid carcinoma.

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Expressional and Functional Characterization of Intracellular pH Regulators and Effects of Ethanol in Human Oral Epidermoid Carcinoma Cells

Background/Aims: To functionally characterize intracellular pH (pH_i) regulating mechanisms, such as Na⁺-H⁺ exchanger (NHE) and Na⁺-HCO₃^- co-transporter (NBC), and further examine effects of ethanol on the pH_i regulating mechanism in human oral epidermoid carcinoma (OEC-M1) cells. Methods: OEC-M1 cells were a gift from Tri-Service General Hospital. Changes of pH_i were detected by microspectrofluroimetry with a pH-sensitive fluorescent dye, BCECF. Isoforms of transporters were examined by Western blot technique. Results: i) the steady-state pH_i value shifted from alkaline (7.35∼7.49) to acidic (7.0∼7.03) following acid/base impacts; ii) in HEPES-buffer system, pH_i recovery following induced-acidification was totally blocked by either removing [Na]_o⁺ or adding HOE 694 (a NHE1 specific inhibitor), which demonstrates existence of NHE1; iii) in HCO₃^-/CO₂-buffer system, the pH_i recovery following induced-acidification was entirely blocked by either removing [Na]_o⁺ or adding HOE 694 plus DIDS (a NBC specific inhibitor), which suggests existence of Na⁺- and HCO₃^–dependent acid-extruder, i.e. NBC; iv) the isoforms of the two acid extruders were NHE1, NBCn1, NBCe1 and NDCBE; v) ethanol (10-1000 mM) showed a biphasic and concentration-dependent effect on resting pH_i (i.e. increase then decrease) by changing the activity of NHE1 and NBC accordingly; vi) treatment with ethanol for 24 hr (<unterline>></unterline> 300 mM) significantly inhibited the expression of NHE1, NBCn1 and NDCBE, while up-regulated NBCe1. Conclusions: Ethanol affects pH_i in a concentration-dependent manner by changing function and expression of NHE1 and NBC isoforms in OEC-M1 cells.

Rational design of multi-stimuli-responsive gold nanorod-curcumin conjugates for chemo-photothermal synergistic cancer therapy.

In recent decades, the development of novel photorelated nanomedicines as precise cancer nanotheranostics has received extensive attention. However, strategies aimed at integrating various stimuli-responsive multimodal therapies are needed. Herein, we developed a novel system for combined plasmonic photothermal therapy (PPTT) and chemotherapy using the tumor microenvironment and near-infrared (NIR)-responsive gold nanorod-drug conjugates (Au NR@Curcumin). To synthesize this conjugate, the alkanethiol aliphatic acid (11-mercaptoundecanoic acid, MUA) group was covalently linked to curcumin via an ester bond. MUA-curcumin conjugates and thiol-end-functionalized PEG were used to replace cetyltrimethylammonium bromide (CTAB) while modifying the surface of the Au NRs. The size, zeta potential and shape were measured to characterize Au NR@Curcumin. The release of curcumin from Au NR@Curcumin was achieved by the cleavage of the esterase-labile ester bond in the tumor microenvironment which was enriched in esterase. Under NIR irradiation, the release of curcumin from Au NR@Curcumin was accelerated, caused by the excellent photothermal effect of the Au NRs. The antitumor effects of Au NR@Curcumin were tested on A549 human lung cancer cells, KB human oral epidermoid carcinoma cells and HepG2 human liver carcinoma cells. The ability of the nanosystem to efficiently control the drug release responding to NIR laser irradiation and act as an outstanding hyperthermia agent was demonstrated. The systematic mechanistic elucidation of the tumor cell killing effect is achieved by inducing apoptosis and the arrest of the cell cycle in the treated cells. The combination of photothermal therapy and chemotherapy using the compact Au NR@Curcumin system showed a strong in vivo anticancer effect superior to that of either of the two treatments alone due to a synergistic effect. These results suggest that Au NR@Curcumin is a novel and promising photoablation agent that may be used for cancer nanotheranostics.

Synthesis and cytotoxicity against KB and NCI-H187 cell lines of sporogen AO-1 analogues

20 Analogues of sporogen AO-1 were synthesized by chemical modification at α,β-unsaturated carbonyl, 3-hydroxyl and vinylic methyl groups of sporogen AO-1 precursor, and were evaluated for their cytotoxic activities against human oral epidermoid carcinoma (KB) and human small cell lung (NCI-H187) cancer cell lines. Structure-activity relationship study indicated the importance of α,β-unsaturated carbonyl moiety for both cancer cell lines. Vinylic methyl and R-configuration of 3-hydroxyl group were crucial for cytotoxicity toward KB cells. In contrast, conversion of vinylic methyl and 3-hydroxyl groups to ketone moieties afforded triketone 19 which displayed comparable cytotoxicity against NCI-H187 cells lines to sporogen AO-1, and was more potent than ellipticine, a standard drug. Interestingly, compound 19 was weakly cytotoxic toward Vero cells, whereas sporogen AO-1 showed strong cytotoxicity.

Preparation and biological evaluation of radiolabeled folate receptor-positive tumor agent 99Tcm-(HYNIC-NHHN-FA) (EDDA)

Objective To prepare a novel radiolabeled FR-positive tumor targeting agent 99Tcm-(HYNIC-NHHN-FA) (EDDA) and evaluate its biological properties. Methods FA derivative FA-NHHN-HYNIC was synthesized and radiolabeled with 99Tcm using EDDA as a coligand. The radiochemical purity, octanal/water partition coefficient and in vitro stabilities of the complex were studied after purified by HPLC. In vitro cellular uptakes were performed on FR-positive KB cells (human oral epidermoid carcinoma cells). Biodistribution and microSPECT/CT imaging were investigated on normal Kunming mice and nude mice bearing KB tumors, respectively. Results The radiochemical purity of the complex was over 95% after purified by HPLC. It displayed high stability both in saline and in serum. It also exhibited high specific FR binding in FR-positive KB cells in vitro. The binding ratio was (6.76±0.60)% 1 h after incubation, and decreased to (0.24±0.02)% after adding excessive FA. The results of biodistribution showed high kidney uptake in normal mice, and the uptake reached (21.79±9.79) %ID/g 0.5 h after injection. Flank KB tumors were clearly visualized with 99Tcm-(HYNIC-NHHN-FA)(EDDA) by microSPECT/CT imaging at 2 h postinjection, and the uptake could be inhibited by excessive FA. Conclusions 99Tcm-(HYNIC-NHHN-FA)(EDDA) exhibits good pharmacokinetic properties, suggesting its potential as a promising FA targeting agent for tumor imaging. Key words: Folic acid; Isotope labeling; Technetium; Carcinoma; Tomography, emission-computed, single-photon; Tomography, X-ray computed; Mice

Synthesis biological screening and molecular docking studies of some tin (IV) Schiff base adducts

The search for an alternative to platinum anticancer agents is a major motivation for continuing investigations concerning the antitumor properties of other transition metal-based compounds. Keeping this in view, synthesis, antitumor and antimicrobial activity of diorganotin (IV) complexes was studied. A novel series of diorganotin (IV) complexes of the Schiff base ligand derived from 7-methoxy-2-hydroxy-1-naphthaldehyde, 1,2-phenylenediamine, Salicylaldehyde were synthesized. Physical and spectral examination was done through various techniques using elemental analyses, IR, 1H, 13C, 119Sn NMR, and 119mSn Mössbauer techniques respectively. The results obtained are in good agreement with 1:1:1 stoichiometry of Schiff base and 2:1 stoichiometry of the complexes. Octahedral geometry was assigned to all the synthesized complexes within six (6) coordination number around the tin. Antitumor activity was screened against human oral epidermoid carcinoma (KB) cell line. The diethyltin (IV) complex 2 showed the most promising cytotoxic results (IC50=0.35μM) against the cell line which is comparable with cisplatin (IC50=0.37μM). Docking studies revealed that these complexes can bind favorably within cisplatin binding site and the binding energy of complex 2 is more than that of cisplatin. Furthermore, binding of these complexes on human topoisomerase IIα enzyme and revealed that these complexes intercalating within the inter-strand of DNA showing interactions with DNA as well as protein that may results in DNA damage and cell death.

Synthesis and cytotoxic activities of semisynthetic zearalenone analogues

Zearalenone is a β-resorcylic acid macrolide with various biological activities. Herein we report the synthesis and cytotoxic activities of 34 zearalenone analogues against human oral epidermoid carcinoma (KB) and human breast adenocarcinoma (MCF-7) cells as well as noncancerous Vero cells. Some zearalenone analogues showed moderately enhanced cytotoxic activities against the two cancer cell lines. We have discovered the potential lead compounds with diminished or no cytotoxicity to Vero cells. Preliminary structure–activity relationship studies revealed that the double bond at the 1′ and 2′ positions of zearalenone core was crucial for cytotoxic activities on both cell lines. In addition, for zearalenol analogues, the unprotected hydroxyl group at C-2 and an alkoxy substituent at C-4 played key roles on cytotoxic effects of both cell lines.

Abstract LB-098: Antitumor studies: Design, synthesis, antitumor activity and molecular docking study of novel 2-deoxo-2-substituted-5-deazaalloxazines

Abstract Cancer is the major threat to the public health worldwide, thereby we have a considerable interest to get potential antitumor agents via computational design, synthesis, functional elucidation, and biological evaluation of different deazaalloxazine analogs. Many of these compounds revealed higher selectivities against different tumor cell lines. In the study the structure activity relationships (SAR) of the proposed derivatives was investigated, by applying structure based drug design (SBDD) using most advanced molecular modeling tool programs, namely: AutoDock 4.2 and Accelrys Discovery studio 2.0. These computational approaches aim to increase the speed and efficiency in the drug discovery process. The reasonable drug candidates were subjected to the chemical synthesis and biological in vitro test against different tumor cell lines. The docking study of the synthesized and the rationally designed derivatives was carried out using PTKs as target enzymes which was early reported as a proposed pathway for inhibition of cancer. The main outcome of this study is the synthesis of novel 2-methylthio, 2-(substituted alkyl amino), 2-(heterocyclic substituted), 2-amino, 2,4-dioxo and 2-deoxo-5-deazaalloxazine derivatives. Their antitumor activities against human T-cell acute lymphoblastoid leukemia cell line (CCRF-HSB-2), human oral epidermoid carcinoma cell line (KB), human breast cancer cell line (MCF-7) and human cervical cancer cell line (Hela) have been investigated in vitro. Many compounds showed promising antitumor activities. Furthermore, AutoDock study has been done by binding of the 5-deazaalloxazine analogs into c-kit PTK (PDB code: 1t46), where a good correlation between their IC50 and AutoDock binding free energy was exhibited. Citation Format: Sawsan A. Mahmoud, Mosaad S. Mohamed, Nageh A. Abou Taleb, Tomohisa Nagamatsu, Hamed I. Ali. Antitumor studies: Design, synthesis, antitumor activity and molecular docking study of novel 2-deoxo-2-substituted-5-deazaalloxazines. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr LB-098. doi:10.1158/1538-7445.AM2015-LB-098

Synthesis of 6-Azapurines by Transformation of Toxoflavins and Reumycins (7-Azapteridines) and their Cytotoxicities

This paper describes a reliable and facile synthesis of 6-azapurines, 1,5-dimethyl-1H-imidazo[4,5-e][1,2,4]triazin-6(5H)-ones and 5-methyl-5H-imidazo[4,5-e][1,2,4]triazin-6(7H)-ones, by treatment of toxoflavins and reumycins with 10 % aqueous or ethanolic sodium hydroxide at 5–70°C or reflux, followed by decarboxylation and oxidation by air along with a benzilic acid type rearrangement. Furthermore, heating the produced 6-azapurines in 10 % ethanolic sodium hydroxide afforded the corresponding 1-methyl-5,6-dioxo-1,4,5,6-tetrahydro-1,2,4-triazines with 1-methylurea. The antitumour activities of the 6-azapurines against CCRF-HSB-2 (human T-cell acute lymphoblastoid leukemia) and KB (human oral epidermoid carcinoma) cell lines were also investigated in vitro and some of the compounds showed prospective antitumour activities.

Identification of Cytotoxicity Intermediate Products and Degradation Pathways for Microcystins Using Low-Frequency Ultrasonic Irradiation

In this study, two microcystins (MCs) were examined. MC-LR and MC-RR were degraded with low frequencies (20, 40, 60, 100, and 200 kHz) of ultrasonic waves. The optimal ultrasonic frequency for treating MCs was 200 kHz. Kinetic reaction results indicated that the degradation reactions of MC-LR and MC-RR from low-frequency ultrasound obeyed the pseudo-first-order kinetic model. The structural characterizations of the intermediate products were identified via liquid chromatography-mass spectrometry, which elucidated the mechanism of the degradation pathways. The main degradation pathways in the LC-MS analysis were Adda and Mdha. The cytotoxic effects on human oral epidermoid carcinoma (KB) cells were evaluated through cell viability assay using 3-(4, 5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide. The inhibitory effect of ≥5 μg/mL MC-LR on KB cells was significantly enhanced in a dose-dependent manner. Compared with the control, the viability of the KB cells cultured with 15 and 5 μg/mL MC-LR was increased by 23 % and 29 %, respectively, after the application of MC-LR and the optimization of the frequencies' ultrasonic irradiated treatment for 48 h. A similar trend was observed in the degradation of ultrasonic irradiated MC-RR. Compared with the control, the viability of the KB cells cultured with 15 and 5 μg/mL MC-RR increased by 12 % and 22 %, respectively (P < 0.05). Results showed that low-frequency ultrasonic irradiation effectively reduced the cytotoxicity of the intermediate products of MCs. Therefore, low-frequency ultrasound is a feasible method for the detoxification of drinking water.

Short Double-Stranded RNA with Immunostimulatory Activity: Sequence Dependence

Small interfering RNAs (siRNA) are able to activate the mammalian innate immune system depending on their structure, sequence, and method of delivery. The immunostimulatory activity of double-stranded RNA can be applied to antiviral and antitumor therapy. Here we identified a set of 19-bp RNA duplexes with 3-nucleotid overhangs in the 3' ends that display immunostimulating activity (here and after immunostimulating RNA, or isRNA) and studied their sequence/activity relationships. It was found that the introduction of substitutions in the middle part of the isRNA sequence (10-16 positions counting from the 5' end of strand 1) does not alter the antiproliferative activity, while substitutions in the 3' end region of isRNA substantially reduce it. isRNAs efficiently inhibit the proliferation of human oral epidermoid carcinoma cells [half-maximal inhibitory concentration (IC(50)) values varied from 10 to 100 nM]. Our research demonstrated that antiproliferative effects of isRNAs are related to cell growth arrest, rather than the induction of apoptosis. These isRNAs strongly stimulate the synthesis of interferon-α (IFN-α), and to a lesser extent the synthesis of tumor necrosis factor (TNF-α) and interleukin-6 (IL-6), in adherent peripheral blood mononuclear cells. An intravenous injection of isRNA/Lipofectamine complexes into C57BL mice increases IFN-α and IL-6 levels in the blood serum up to 15-fold and 3-fold, respectively, compared to the control mice. The results obtained clearly demonstrate the pronounced immunostimulatory and antiproliferative properties of the isRNAs under study. Hence, these short double-stranded RNAs can be considered as potential agents for the therapy of oncological and viral diseases.

Essential Oil from Cryptomeria japonica Induces Apoptosis in Human Oral Epidermoid Carcinoma Cells via Mitochondrial Stress and Activation of Caspases

Cryptomeria japonica D. Don (C. japonica) has been used in traditional medicines from Asia for a variety of indications, including liver ailments, and an antitussive, and for its antiulcer activities. We examined the cell viability and apoptosis of KB cells treated with C. japonica essential oil at several concentrations for 12 h by MTT assay, Hoechst-33258 dye staining, DNA fragmentation, flow cytometry (cell cycle), and Western blotting for mitochondria stress, activation of caspases, and poly (ADP-ribose) polymerase. The essential oil induced the apoptosis of KB cells in a dose-dependent manner, which was verified by DNA fragmentation, appearance of apoptotic bodies, and the sub-G1 ratio. The essential oil also induced rapid and transient caspase-3 activity and cleavage of PARP of the KB cells. Treating the cells with the oil also caused changes in the mitochondrial level of the Bcl-2 family proteins such as Bcl-2 and Bax, thereby inducing the release of cytochrome c into the cytosol. The essential oil of C. japonica may have potential as a cancer chemopreventive and therapeutic agent.

Fischerisin A and B, Cytotoxic Sesquiterpenoid-Geranylhydroquinones from Ligularia fischeri

During the course of screening natural sesquiterpenoids for new antitumor agents, two novel compounds, fischerisin A (1) and fischerisin B (2), were isolated from the roots of Ligularia fischeri. Their structures were elucidated by interpretation of their IR, high resolution-mass spectrometry (HR-MS), 1D- and 2D-NMR data. Fischerisin A and B are the first representatives of a novel sesquiterpenoid-geranylhydroquinone hybrid, and both compounds exhibited in vitro cytotoxicity against cultured human oral epidermoid carcinoma (KB) and human breast cancer (MCF-7) cell lines with IC(50) values of 9.7 and 10.2 µM, and 9.8 and 17.8 µM, respectively.