Growth inhibition of high-intensity focused ultrasound on hepatic cancer in vivo

AIM： To investigate the damaging effect of high-intensity focused ultrasound （HIFU） on cancer cells and the inhibitory effect on tumor growth. METHODS： Hurine H22 hepatic cancer cells were treated with HIFU at the same intensity for different lengths of time and at different intensities for the same length oftime in vitro, the dead cancer cells were determined by trypan blue staining. Two groups of cancer cells treated with HIFU at the lowest and highest intensity were inoculated into mice. Tumor masses were removed and weighed after 2 wk, tumor growth in each group was confirmed pathologically.RESULTS： The death rate of cancer cells treated with HIFU at 1 000 W/cm^2 for 0.5, 1, 2, 4, 8, and 12 s was 3.11±1.21%, 13.37±2.56%, 38.84±3.68%, 47.22±5.76%,87.55±7.32%, and 94.33±8.11%, respectively. A positive relationship between the death rates of cancer cells and the length of HIFU treatment time was found （r = 0.96,P〈0.01）. The death rate of cancer cells treated with HIFU at the intensity of 100, 200, 400, 600, 800, and 1 000 W/cm^2 for 8 s was 26.31±3.26%, 31.00±3.87%, 41.97±5.86%,72.23±8.12%, 94.90±8.67%, and 99.30±9.18%, respectively. A positive relationship between the death rates of cancer cells and the intensities of HIFU treatment was confirmed （r= 0.98, P〈0.01）. The cancer cells treated with HIFU at 1 000 W/cm^2 for 8 s were inoculated intomice ed into. The tumor inhibitory rate was 90.35% compared to the control （P〈0.01）. In the experimental group inoculated with the cancer cells treated with HIFU at 1 000 W/cm^2 for 0.5 s, the tumor inhibitory rate was 22.9% （P〈0.01）. By pathological examination, tumor growth was confirmed in 8 out of 14 mice （57.14%, 8/14） inoculated with the cancer cells treated with HIFU at 1 000 W/cm^2 for 8 s, which was significantly lower than that in the control （100%, 15/15, P〈O.05）.CONCLUSION： HIFU is effective on killing or damage of H22 hepatic cancer cells in vitro and on inhibiting tumor growth in mice ex vivo.

The Arabidopsis P450 protein CYP82C2 modulates jasmonateinduced root growth inhibition, defense gene expression and indole glucosinolate biosynthesis

Jasmonic acid （JA） is a fatty acid-derived signaling molecule that regulates a broad range of plant defense responses against herbivores and some microbial pathogens. Molecular genetic studies have established that JA also performs a critical role in several aspects of plant development. Here, we describe the characterization of the Arabidopsis mutantjasmonic acid-hypersensitivel-1 （jah1-1）, which is defective in several aspects of JA responses. Although the mutant exhibits increased sensitivity to JA in root growth inhibition, it shows decreased expression of JA-inducible defense genes and reduced resistance to the necrotrophic fungus Botrytis cinerea. Gene cloning studies indicate that these defects are caused by a mutation in the cytochrome P450 protein CYP82C2. We provide evidence showing that the compromised resistance of thejah1-1 mutant to B. cinerea is accompanied by decreased expression of JA-induced defense genes and reduced accumulation of JA-induced indole glucosinolates （IGs）. Conversely, the enhanced resistance to B. cinerea in CYP82C2-overexpressing plants is accompanied by increased expression of JA-induced defense genes and elevated levels of JA-induced IGs. We demonstrate that CYP82C2 affects JA-induced accumulation of the IG biosynthetic precursor tryptophan （Trp）, but not the JA-induced IAA or pathogen-induced camalexin. Together, our results support a hypothesis that CYP82C2 may act in the metabolism of Trp-derived secondary metabolites under conditions in which JA levels are elevated. Thejah1-1 mutant should thus be important in future studies toward understanding the mechanisms underlying the complexity of JA-mediated differential responses, which are important for plants to adapt their growth to the ever-changing environments.

Transactivation of the TIEG1 confers growth inhibition of transforming growth factor-β-susceptible hepatocellular carcinoma cells

AIM:To investigate the role of transforming growth factor(TGF)-β-inducible early gene 1(TIEG1) in TGF-β-induced growth inhibition in hepatocellular carcinoma(HCC) cells.METHODS:Human hepatocyte and HCC cell lines with varied susceptibilities to TGF-β1 were tested by methylthiazoletetrazolium(MTT) assay.The expression changes of Smad2,Smad3,Smad4,Smad7,TIEG1 and TIEG2 gene following treatment with TGF-β1 in a TGF-β-sensitive hepatocyte cell line(MIHA),a TGF-β-sensitive hepatoma cell line(Hep3B) and two TGF-β-insensitive hepatoma cell lines(HepG2 and Bel7404) were examined.SiRNA targeting TIEG1 was transfected into Hep3B cells and the sensitivity of cells to TGF-β1 was examined.Overexpression of TIEG1 was induced by lentiviral-mediated transduction in TGF-β1-resistant hepatoma cell lines(Bel7404 and HepG2).MTT assay and 4',6-Diamidino-2-phenylindole staining were used to identify cell viability and apoptosis,respectively.The expression level of stathmin was measured by reverse transcriptase polymerase chain reaction and Western-blotting analysis,and stathmin promoter activity by TIEG1 was monitored by a luciferase reporter gene system.RESULTS:TIEG1 was significantly upregulated by TGF-β1 in the TGF-β1-sensitive HCC cell line,Hep3B,but not in the resistant cell lines.The suppression of TIEG1 by siRNAs decreased the sensitivity of Hep3B cells to TGF-β1,whereas the overexpression of TIEG1 mediated growth inhibition and apoptosis in TGF-β1-resistant HCC cell lines,which resembled those of TGF-β1-sensitive HCC cells treated with TGF-β1.Our data further suggested that stathmin was a direct target of TIEG1,as stathmin was signif icantly downregulated by TIEG1 overexpression,and stathmin promoter activity was inhibited by TIEG1 in a dose-dependent manner.CONCLUSION:Our data suggest that transactivation of TIEG1 conferred growth inhibition of TGF-β-susceptible human HCC cells.

Growth Inhibition of Breast Cancer in Rat by AAV Mediated Angiostatin Gene

Objective： To observe growth inhibition effect of adeno-associated viral vectors （AAV） mediated angiostatin （ANG） gene on implanted breast cancer in rat and its mechanism. Methods： Gene transfer technique was used to transfer AAV-ANG to the tumor. Growth curves were drawn to observe the growth of breast cancer implanted in rat, and immunohistochemical method was used to detect the effects of angiostatin on microvesel density （MVD） of breast cancer implanted in rat. Results： Angiostatin inhibited the growth of breast cancer implanted in rat and decreased the microvessel density of tumor. Conclusion： Expression of an angiostatin transgene can suppress the growth of breast cancer implanted in rat through the inhibition of the growth of microvessels, surggesting that angiostatin gene transfer technique may be effective against breast cancer.

Growth Inhibition and Apoptosis Induced by Retinoic Acid Combined with Interferon Alpha-2a on Transitional Cell Carcinoma of Bladder

Objective:To identify new favorable agents and develop novel approaches for the chemoprevention and treatment of superficial bladder cancer and investigate the effects of combination of retinoids and interferon α-2a on growth inhibition and apoptosis induction in bladder cancer cell lines. Methods:Four bladder cancer cell lines,grade 1 to 3,and two retinoids,all-trans-retinoic acid(ATRA),9-cis retinoic acid(9cRA),combined with interferon α-2a(INF),were used in the study.We compared the competence of these agents to inhibit growth,induce apoptosis,affect the expression of nuclear retinoid receptors,and modulate STAT1 protein. Results: Most of the bladder cancer cell lines were resistant to the effect of ATRA and 9cRA on growth inhibition and apoptosis induction,even at higher concentration(10 -5M).The effects of ATRA and 9c RA on cell growth and apoptosis were enhanced by INF α- 2a. Combination of ATRA and IFNα-2a induced RARβ and Stat 1 expression in three bladder cancer cell lines. Conclusion:The results demonstrated that INFα-2a synergize with the inhibitory effect of ATRA and 9c RA on the growth inhibition and apoptosis of bladder cancer cells in vitro,which suggested that it has a potential interest for the treatment of transitional cell carcinoma of bladder.

Growth inhibition to three red tide microalgae by extracts of Ulva pertusa

Growth inhibition effect of different concentration of distilled water extract and four polar organic solvent (methanol, acetone, ether and chloroform) extracts of Ulva pertusa on three typical red tide microalgae (Heterosigma akashiwo, Alexandrium tamarense and Prorocentrum micans) were inves- tigated. Liquid-liquid fractionation and HPLC analysis for methanol extract of U. pertusa were carried out. Growth of the three microalgae was significantly inhibited by the distilled water extract of U. pertusa at relatively higher concentration. However, the cells of the three microalgae did not die completely even at high concentration. Methanol extract of U. pertusa showed the highest growth inhibition on the three mi- croalgae, and all the cells of the three microalgae were killed at relatively high concentration. The other three organic solvent extracts of U. pertusa had no apparent effect on the three microalgae. The results of bioassays and HPLC analysis suggested that the inhibitory substances in U. pertusa to the microalgal growth had relatively high polarities. H. akashiwo was the most sensitive one while A. tamarense was the most tolerant one to the growth inhibitory substances.

Growth Inhibition, Induction of Apoptosis by Green Tea Constituent (-)-Epigallocatechin-3-gallate in Cultured Rabbit Lens Epithelial Cells

Purpose: To evaluate effect of green tea extract (-)-Epigallocatechin-3-gallate (EGCG) in cultured rabbit lens epithelial cells in order to pave a new way to postcapsular opacity (PCO) prevention.Methods: Cell survival rate was measured by 3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyl tetrazolium bromide (MTT) coloimetric assay. Cell apoptosis was detected by electron microscopy, Hochest 33258 stain and flow cytometer. DNA fragment was detected using agarose gel electrophoresis.Result: Proliferation of the cultured rabbit lens epithelia cells was inhibited by EGCG in a dose and time dependent manner. Morphologic study showed that the cells became shrunk, round shaped with their nuclei condensed and broken. Apoptotic bodies were also seen under electron microscope and in Hochest 33258 stain assay 24 hours after EGCG was added to the medium. DNA ladders were shown in agarose gel eletrophoresis. In flow cytometry assay, apoptosis peak was also evident.Conclusion: Green Tea Constituent(-)

Identifying Combinatorial Growth Inhibitory Effects of Various Plant Extracts on Leukemia Cells through Systematic Experimental Design

Plant extracts are widely studied for their anti-cancer and cancer preventive effects. In this study, we compared the leukemia growth inhibition effects of seven different plant extracts, theaflavin, epigallocatechin gallate (EGCG), epicathechin (EC), apigenin, quercetin, chrysin and tannic acid, in vitro using the K562 erythroleukemia cell line and application of the design of experiments (DoE) methodology. Our systematic approach enabled us to isolate the main factor contribution, two-factor interactions and produced interaction relationships and/or models to describe growth inhibitory effects of different plant extracts when they are used in combination. The results identified tannic acid as the most significant inhibitor in this group and had synergistic effects with EGCG at specific concentrations. The fitted model of their combined effects showed that the most potent combination is at low concentrations of tannic acid (10 - 20 μM) and high concentrations of EGCG (80 - 100 μM). We further showed that tannic acid induced both growth inhibition and apoptosis in K562 cells in ranges between 10 - 100 μM. The polyphenol caused cell cycle arrest at G2- phase under the higher concentrations. In summary, use of DoE techniques effectively identified the most prominent inducer in this group of plant bioactive compounds and produced combinatorial bioactivity of various polyphenols and flavonoids over the entire range of concentrations under study. This study exemplifies the usefulness of DoE and serves as a guide in its utility for in vitro assessment of bioactivity in plant constituents.

Allelopathic Effects of Adonis vernalis L.: Root Growth Inhibition and Cytogenetic Alterations

A possible alternative to synthetic agricultural chemicals is through the use of allelopathy. Adonis species are rich sources of secondary metabolites. Such allelochemicals offer potential for the development of future pesticides. Allelochemicals influence plant growth and cause morphological alterations. This visible effect could be due to primary effects at cellular or molecular level. Changes in the mitotic activity and disturbances in different phases of mitotic division are accepted as indicators of cytotoxic influence. Mitotic abnormalities and induction of micronuclei in interphase cells are parameters used to determine genotoxicity. The purpose of the current study was to establish the possible allelopathic effect of Adonis vernalis L. water extracts through evaluation of root growth inhibition effect and cytogenetic alterations. Adonis vernalis L. growing wild in Bulgaria was used in the present study. Two types of water extracts were prepared: Hot and Cold Water Extract of A. vernalis (HWЕА and СWЕА). A 72-h root growth inhibition test was provided in order to determine the toxicity level of extracts. EC50 values were determined. For toxicity test, seeds of Triticum aestivum L. cv. GTW were used. Cytotoxic and genotoxic potential of water extracts (EC50) were evaluated using Allium cepa L.-test. The EC50 for HWEA and CWEA was determined 1.83 g/l and 0.78 g/l respectively. Significant influence on mitotic activity values and a marked decrease in percentage of telophase cells were observed after treatment with both extracts. Adonis extracts also induced different mitotic abnormalities in root-tip cells of Allium cepa L. The percent of interphase cells with micronuclei increased significantly only after treatment with HWEA. The results indicated growth inhibitory, cytotoxic and genotoxic effects of crude water extracts of A. vernalis L. These effects demonstrated the presence of water soluble allelochemicals in Adonis aerial parts.

Growth inhibition and oxidative stress in two species of marine diatoms exposed to 1-phenylethanol

1-phenylethanol (1-PEA) is a flavor extensively used in the production of cosmetics, beverages, and food. The release of 1-PEA into coastal environments has aroused great concern. However, its potential effects on marine organisms are still unknown. In order to provide a better understanding of the ecological risks of 1-PEA in marine environments, this study determined the toxic effects of 1-PEA on two marine diatoms (Phaeodactylum tricornutum and Skeletonema costatum). The diatoms were grown in culture medium containing different concentrations of 1-PEA for 96 h. The contents of chlorophyll a, chlorophyll c, glutathione (GSH), malondialdehyde (MDA), and the activities of superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GPx), were measured at the end of the exposure period. 1-PEA was shown to significantly inhibit the growth of diatoms, with 96-h EC50 values of 257.14 mg/Land 126.46 mg/L in P. tricornutum and S. costatum, respectively. In P. tricornutum, the levels of SOD, CAT, GPx, GSH, and MDA were stimulated only when 1-PEA concentrations were close to or greater than the 96-h EC50 value. However, in S. costatum, the activities of SOD and CAT, and the syntheses of two chlorophylls were inhibited even at an exposure concentration below the 96-h EC50 value. Taken together, these findings indicate a potential ecological risk by discharging 1-PEA into coastal areas and its species-specific toxic effects on marine organisms.

Effectiveness of Ringworm Cassia and Turmeric Plant Extracts on Growth Inhibition against Some Important Plant Pathogenic Fungi

Crude plant extracts of ringworm cassia, Cassia alata L. and turmeric, Curcuma longa L. were prepared by either hot water or organic solvents such as ethanol and ether. Various concentrations of the crude extract were then subjected to an in vitro test for their effectiveness on mycelia growth inhibition against some important plant pathogenic fungi such as Alternaria alternata, Colletotrichum gloeosporioides, Fusarium oxysporum fsp. lycopersici, Sclerotium rolfsii, Phytophthora infestans and Pythium sp. in comparison to commercial fungicides such as copper oxychloride and mancozeb. Reduction of the fungal growth was significantly obtained with C. longa extracts and the best median effective inhibitory concentration (IC50) value of 6.07, 6.50 and 7.13 mg/ml was from the ethanol extract for S. rolfsii, C. gloeosporioides and F. oxysporum fsp. lycopersici respectively. While all extracts from C. alata were almost the least effective against these fungi. The efficacy of C. longa extracts therefore, provided an alternative regime for the control of the fungal diseases and a promising appreciable choice for a replacement of chemical fungicides.

Effect of Vitamin K1 on Cell Growth Inhibition and Apoptosis on the U937 Cell Line

This experiment was conducted in order to verify the role of Vitamin K1 as a cell growth inhibitor on the U937 cell line. This experiment was performed in two parts—one with a lesser concentration of Vitamin K1, and the other with a range of concentrations from low-to-high. Through the remaining number of U937 cells, as well as cell areas, it was concluded that the presence of Vitamin K1 reduces the number of cancer cells. It was also concluded that as Vitamin K1 concentration increases, so does the frequency and effects of apoptosis.

Trojan horses in tumor:engineered pyroelectric and photodynamic nanocomposites for NIR-induced cell apoptosis and tumor growth inhibition

It is desirable but always challenging to develop a cutting-edge tumor treatment strategy with high therapeutic efficacy,lesiontargeted precision and mild accessibility.Compared to traditional treatment modalities,photodynamic therapy has been widely studied since the generation of reactive oxygen species(ROS)at cancerous lesions unprecedentedly offers a convenient approach for localized tumor eliminations.Nevertheless,the consumption of oxygen for ROS production in a hypoxic tumor microenvironment has dramatically limited its feasibility and efficacy.Herein,the engineered nanocomposites of BTO@PDA-ICGHA with photodynamic and pyroelectric performances have been fabricated and applied to the photodynamic-pyroelectric dynamic treatments.The continuing ROS production derived from intracellular oxygen(O_(2))and water(H_(2)O)by laser irradiation contributed to the superb tumor cell apoptosis and significant tumor growth inhibition.Thus,this study has validated a new concept by depositing the engineered nanocomposites at the tumor just like Trojan horses,facilitating ROS release as killers and exerting the NIR-induced cell apoptosis and tumor growth inhibition with high therapeutic efficiency and expectable translational perspectives.

Growth and inhibition of zinc anode dendrites in Zn-air batteries:Model and experiment

Zinc(Zn)-air batteries are widely used in secondary battery research owing to their high theoretical energy density,good electrochemical reversibility,stable discharge performance,and low cost of the anode active material Zn.However,the Zn anode also leads to many challenges,including dendrite growth,deformation,and hydrogen precipitation self-corrosion.In this context,Zn dendrite growth has a greater impact on the cycle lives.In this dissertation,a dendrite growth model for a Zn-air battery was established based on electrochemical phase field theory,and the effects of the charging time,anisotropy strength,and electrolyte temperature on the morphology and growth height of Zn dendrites were studied.A series of experiments was designed with different gradient influencing factors in subsequent experiments to verify the theoretical simulations,including elevated electrolyte temperatures,flowing electrolytes,and pulsed charging.The simulation results show that the growth of Zn dendrites is controlled mainly by diffusion and mass transfer processes,whereas the electrolyte temperature,flow rate,and interfacial energy anisotropy intensity are the main factors.The experimental results show that an optimal electrolyte temperature of 343.15 K,an optimal electrolyte flow rate of 40 ml·min^(-1),and an effective pulse charging mode.

Inhibitory effect of arsenic trioxide on angiogenesis and expression of vascular endothelial growth factor in gastric cancer

AIM: To investigate the inhibitory effect of As2O3 on angiogenesis of tumor and expression of vascular endothelial growth factor (VEGF) in tumor cells in vivo and in vitro. METHODS: The solid tumor model was formed in nude mice with the gastric cancer cell line SGC-7901. The animals were randomly divided into three groups. As2O3 was injected into the arsenic-treated groups (2.5 mg/kg and 5 mg/kg) and the same volume of saline solution was injected into the control group. Microvessel density (MVD) and expression of VEGF were detected with immunofluorescence laser confocal technology. Further expression of VEGF protein and VEGF mRNA was measured with Western bloting and fluorescence quantitative RT- PCR in SGC-7901 cells treated with As2O3. RESULTS: In nude mice, after treatment with 5 mg/kg and 2.5 mg/kg As2O3 respectively, about 50% and 30% tumor growth inhibition were observed correspondingly (P < 0.05, P < 0.05). Decrease in MVD appeared in As2O3-treated tumors compared with control group (P < 0.001, P < 0.001). MVD in tumors was significantly lower in 5 mg/kg group than in 2.5 mg/kg group (P < 0.01). The fluorescence intensity levels of VEGF in tumor cells were significantly lowered in the arsenic-treated groups (P < 0.01, P < 0.01). The fluorescence intensity level of VEGF in 5 mg/kg group was lower than that in 2.5 mg/ kg group (P < 0.01). In vitro, the expression of VEGF protein decreased in dose- and time-dependent manner after the treatment with As2O3, but in VEGF mRNA no significant difference was found between the control group and the treated groups. CONCLUSION: As2O3 can inhibit solid tumor growth by inhibiting the formation of new blood vessels. One of the mechanisms is that As2O3 can inhibit VEGF protein expression.

Sirolimus inhibits growth of human hepatoma cells alone or combined with tacrolimus, while tacrolimus promotes cell growth

AIM: Standard immunosuppression after organ transplantation stimulates tumor growth. Sirolimus has a strong antiproliferative and a tumor inhibiting effect. The purpose is to assess the effect on tumor growth of the immunosuppressive compounds sirolimus and tacrolimus alone and in combination on cells of human hepatocellular carcinoma.METHODS: We used the human cell lines SK-Hep 1 and Hep 3B derived from hepatocellular carcinoma. Proliferation analyses after treatment with sirolimus, tacrolimus, or the combination of both were performed. FACS analyses were done to reveal cell cycle changes and apoptotic cell death. The expression of apoptosis-related proteins was estimated by Western blots.RESULTS: Sirolimus alone or combined with tacrolimus inhibited the growth of both cell lines after 5 d by up to 35% in SK-Hep 1 cells, and by up to 68% in Hep 3B cells at 25 ng/mL. Tacrolimus alone stimulated the growth by 12% after 5 ng/mL and by 25% after 25 ng/mL in Hep 3B cells. We found an increase of apoptotic Hep 3B cells from 6 to 16%, and a G1-arrest in SK-Hep 1 cells with an increase of cells from 61 to 82%, when sirolimus and tacrolimus were combined. Bcl-2 was down-regulated in Hep 3B, but not in SK-Hep 1 cells after combined treatment.CONCLUSION: Sirolimus appears to inhibit the growth of hepatocellular carcinoma cells alone and in combination with tacrolimus. Sirolimus seems to inhibit the growth stimulation of tacrolimus.

Potassium channel AKT1 is involved in the auxin-mediated root growth inhibition in Arabidopsis response to low K^+stress

The changes in external K^＋ concentration affect plant root growth. However, the molecular mechanism for perceiving a K^＋ signal to modulate root growth remains unknown. It is hypothesized that the K^＋ channel AKTI is involved in low K^＋ sensing in the Arabidopsis root and subsequent regulation of root growth. Along with the decline of external K^＋ concentration, the primary root growth of wild-type plants was gradually inhibited. However, the primary root of the akt1 mutant could still grow under low K^＋（LK） conditions. Application of NAA inhibited akt1 root growth, but promoted wild-type root growth under LK conditions. By using the ProDR5：GFP and ProPIN1：PIN1-GFP lines, we found that LK treatment reduced auxin accumulation in wild-type root tips by degrading PIN1 proteins, which did not occur in the akt1 mutant. The LK-induced PIN1 degradation may be due to the inhibition of vesicle trafficking of PIN1 proteins. In conclusion, our findings indicate that AKT1 is required for an Arabidopsis response to changes in external K^＋, and subsequent regulation of K^＋-dependent root growth by modulating PINt degradation and auxin redistribution in the root.

Inhibition of human gastric carcinoma cell growth by atofluding derivative N_3-o-toluyl-fluorouracil

AIM： To evaluate the growth inhibition efficacy of atofluding derivative N3-o-toluyl-fluorouracil （TFU） on human gastric carcinoma cell lines SGC-7901 and MKN-45. METHODS： Cell growth inhibition by TFU was measured by MTT and clonogenic assays without or with liver microsomal enzymes. Xenografts of cancer cells in nude mice were employed to study the anti-proliferative effects of TFU in vivo. RESULTS： TFU inhibited the growth of SGC-7901 and MKN-45 cells. However, the inhibitory effects of TFU on cell growth were not significant. The inhibition rates were enhanced in the presence of liver microsomal enzymes, ranging 4.73%-48.57% in SGC-7901 cells and 9.0%-62.02% in MKN-45 cells. In v/vo, TFU delayed the growth of SGC-7901 and MKN-45 cells in nude mice. The inhibition rates were 40.49%, 63.24%, and 75.98% in SGC-7901 cells and 40.76%, 61.41%, and 82.07% in MKN-45 cells when the oral doses were 25, 50, and 100 mg/kg, respectively. TFU treatment was generally well tolerated by mice with less than 20% reduction in body weight. CONCLUSION： TFU inhibits the growth of human gastric carcinoma cells. The inhibition rates are increased in the presence of liver microsomal enzymes. The efficacy of TFU may be associated with the sustaining release of 5-fluorouracil （5-FU） mediated by the enzymes.

PIF3 Is Involved in the Primary Root Growth Inhibition of Arabidopsis Induced by Nitric Oxide in the Light

PHYTOCHROME INTERACTING FACTOR3 （PIF3） is an important component in the phytochrome signaling pathway and mediates plant responses to various environmental conditions. We found that PIF3 is involved in the inhibition of root growth of Arabidopsis thaliana seedlings induced by nitric oxide （NO） in light. Overexpression of PIF3 partially alleviated the inhibitory effect of NO on root growth, whereas the pif3-1 mutant displayed enhanced sensitivity to NO in terms of root growth. During phytochrome signaling, the photoreceptor PHYB mediates the degradation of PIF3. We found that the phyB-9 mutant had a similar phenotype to that of PIF3ox in terms of responsiveness to NO. Furthermore, NO treatment promoted the accumulation of PHYB, and thus reduced PIF3 content. Our results further show that the activity of PIF3 is regulated by the DELLA protein RGL3[RGA （repressor of gal-3） LIKE 3]. Therefore, we speculate that PIF3 lies downstream of PHYB and RGL3, and plays an important role in the inhibitory effect of NO on root growth of Arabidopsis seedlings in light.

Experimental Study on Inhibitory Effects of Diallyl Sulfide on Growth and Invasion of Human Osteosarcoma MG-63 Cells

The inhibitory effects of diallyl sulfide(DAS) derived from allicin on in vitro and in vivo proliferation of human osteosarcoma MG-63 cells and the action mechanism,and the influence of DAS on invasive capability of MG-63 cells were investigated in order to search for the novel medicines for osteosarcoma.In the in vitro experiment,MG-63 cells were treated with different concentrations of DSA,and the morphological changes of MG-63 cells were observed under an inverted phase microscope.MTT method was used to assay the proliferation of MG-63 cells.Semi-quantitative reverse transcription polymerase chain reaction(RT-PCR) was used to detect the VEGF mRNA expression level in MG-63 cells.By using Transwell invasion assay,the influence of DAS on invasive ability of MG-63 cells was tested.In the in vivo experiment,the nude mice MG-63 cells tumor-bearing model was established,and different concentrations of DAS were injected beside the tumor.Twenty-one days after treatment,the mice were killed,the tumor size and tumor inhibition rate were calculated.The microvessel density(MVD) was determined by using immunohistochemistry.In the in vitro experiment,different concentrations of DAS could obviously inhibit proliferation of MG-63 cells in a time-and concentration-dependent manner.RT-PCR revealed that the expression levels of VEGF mRNA in DSA groups(different concentrations) were significant reduced as compared with those in control group(all P<0.05).Transwell invasion assay indicated that in 20 and 40 μg/mL DAS groups,the number of migratory cells was 91.4±8.3 and 81.8±7.4 respectively,which was significantly declined as compared with that in control group(150.4±14.7,both P<0.05).In the in vivo experiment,DAS could significantly suppress the growth of MG-63 tumor-bearing tissue.Immunohistochemistry demonstrated that different concentrations(20 and 40 μg/mL) of DAS could significantly decrease MVD of MG-63 tumor-bearing tissue(all P<0.05).It was suggested that DAS could inhibit the growth of MG-63 cells probably by suppressing the expression of VEGF mRNA.