Factors Affecting Central Node Metastasis and Metastatic Lymph Node Ratio in Papillary Thyroid Cancer.

OBJECTIVE: Despite the growing evidence that metastatic lymph node ratio (MLNR) is a valuable predictor for the prognosis of papillary thyroid carcinoma, it has not yet been fully determined which factors give the ratio predictive value independent of the number of metastatic lymph nodes (MLNs). STUDY DESIGN: Retrospective cohort study. SETTING: A comprehensive cancer center. METHODS: Recurrence and clinicopathologic factors were analyzed in 2409 patients with papillary thyroid carcinoma who underwent total thyroidectomy and central node dissection. RESULTS: Cutoff values of MLNs ≥2 and MLNR ≥28.2% increased the recurrence risk (hazard ratio [95% CI], 9.97 [4.73-21.0] and 11.4 [5.53-23.3], respectively). Younger age, male sex, multifocality, tumor size, lymphatic and vascular invasion, and gross extrathyroidal extension positively correlated with MLN and MLNR (all P < .05). Meanwhile, lymphocytic thyroiditis negatively correlated with MLNR in female patients (P < .001), by increasing total lymph node yields as compared with papillary thyroid carcinoma without lymphocytic thyroiditis. In multivariate analysis, younger age, tumor size, and lymphatic invasion remained significant in male and female patients for MLN and MLNR; lymphocytic thyroiditis was also significantly correlated with MLNR in female patients. CONCLUSION: Our study demonstrates that MLN and MLNR are independently observed prognostic markers for tumor recurrence. However, lymphocytic thyroiditis in female patients seems to have lower MLNR by increasing total lymph node yields. In light of their association, a different cutoff for MLNR needs to be applied according to the presence or absence of underlying lymphocytic thyroiditis in the use of MLNR for predicting the recurrence. LEVEL OF EVIDENCE: 4.

Activity of LCB01-0371, a Novel Oxazolidinone, against Mycobacterium abscessus.

Mycobacterium abscessus is a highly pathogenic drug-resistant rapidly growing mycobacterium. In this study, we evaluated the in vitro, intracellular, and in vivo activities of LCB01-0371, a novel and safe oxazolidinone derivative, for the treatment of M. abscessus infection and compared its resistance to that of other oxazolidinone drugs. LCB01-0371 was effective against several M. abscessus strains in vitro and in a macrophage model of infection. In the murine model, a similar efficacy to linezolid was achieved, especially in the lungs. We induced laboratory-generated resistance to LCB01-0371; sequencing analysis revealed mutations in rplC of T424C and G419A and a nucleotide insertion at the 503 position. Furthermore, LCB01-0371 inhibited the growth of amikacin-, cefoxitin-, and clarithromycin-resistant strains. Collectively, our data indicate that LCB01-0371 might represent a promising new class of oxazolidinones with improved safety, which may replace linezolid for the treatment of M. abscessus.

5-diphenylacetamido-indirubin-3'-oxime as a novel mitochondria-targeting agent with anti-leukemic activities.

Current treatment for leukemia largely depends on chemotherapy. Despite the progress in treatment efficacy of chemotherapy, a poor outcome consequent upon chemoresistance against conventional anti-cancer drugs still remains to be solved. In this study, we report 5-diphenylacetamido-indirubin-3'-oxime (LDD398) as a novel mitochondria-targeting anti-leukemic agent, which is a derivative of indirubin used in traditional medicine. Treatment with LDD398 resulted in caspase activation, cell death, and growth arrest at G2/M phases in leukemia cells. Interestingly, LDD398 quickly collapsed mitochondrial membrane potential (MMP) within 1 h, accompanied by cytochrome c release into cytosol and severe depletion of cellular ATP. However, the LDD398-induced cellular events was significantly mitigated by blockage of mitochondrial permeability transition pore (MPTP) opening with chemical and genetic modifications, strongly supporting that LDD398 executes its anti-leukemic activity via an inappropriate opening of MPTP and a consequent depletion of ATP. The most meaningful finding was the prominent effectiveness of LDD398 on primary leukemia cells and also on malignant leukemia cells resistant to anticancer drugs. Our results demonstrate that, among a series of indirubin derivatives, LDD398 induces leukemia cell death via a different mode from indirubin or conventional chemotherapeutics, and can be employed as a potent anti-cancer agent in the treatment for newly diagnosed and relapsed leukemia.

Administration of Radioactive Iodine Therapy Within 1 Year After Total Thyroidectomy Does Not Affect Vocal Function.

UNLABELLED: The purpose of this study was to evaluate the impact of radioactive iodine therapy (RIT) on vocal function during the early follow-up period after total thyroidectomy (TT) using perceptive and objective measurements, questionnaires regarding subjective symptoms, and data on vocal function in a prospectively enrolled and serially followed thyroid cancer cohort. METHODS: Of 212 patients who underwent TT and were screened between January and December 2010 at our hospital, 160 were included in the final analysis. Patients with the following histories were excluded: lateral neck dissection, organic vocal fold disease, external radiotherapy, and voice evaluation during thyroxine withdrawal. Patients were stratified into 3 groups: TT, TT with low-dose RIT (1.1-2.2 GBq), and TT with high-dose RIT (≥3.7 GBq). Voice evaluations were performed before surgery and at 1, 6, and 12 mo after TT. RESULTS: Vocal characteristics were altered after TT, including changes on the grade, roughness, and strain scale; increased amplitude perturbation; decreased fundamental frequency; narrowed pitch range; and global disturbances in subjective functional parameters on the voice handicap index. However, the degree of vocal changes among the 3 groups did not significantly differ within the 1-y postoperative follow-up period. According to the results of subgroup analyses of patients who demonstrated good voice outcomes after TT, there were no significant functional differences among the 3 groups. CONCLUSION: RIT at any dose does not affect vocal function within 1 y of TT.

Induction of human leukemia cell differentiation via PKC/MAPK pathways by arsantin, a sesquiterpene lactone from Artemisia santolina.

Sesquiterpene lactone compounds have received considerable attention in pharmacological research due to their therapeutic effects including anti-cancer and anti-inflammatory activities. In this report, we investigated the effect of arsantin, a sesquiterpene lactone compound present in Artemisia santolina, on cellular differentiation in the human promyelocytic leukemia HL-60 cell culture system. Arsantin significantly induced HL-60 cell differentiation in a concentration-dependent manner. Cytofluorometric analysis indicated that arsantin induced HL-60 cell differentiation predominantly into granulocytes. Both PKC and MAPK inhibitors suppressed the HL-60 cell differentiation induced by arsantin. Moreover, treatment with arsantin increased protein levels of PKCα and PKCßII isoforms, and also induced increased protein levels and phosphorylation form of MAPKs in HL-60 cells. Importantly, arsantin synergistically enhanced differentiation of HL-60 cells in a dose-dependent manner when combined with either low doses of 1,25-(OH)2D3 or ATRA. The ability to enhance the differentiation potential of 1,25-(OH)2D3 or ATRA by arsantin may improve outcomes in the therapy of acute promyelocytic leukemia.

Analysis of gene profiles involved in the enhancement of all-trans retinoic acid-induced HL-60 cell differentiation by sesquiterpene lactones identifies asparagine synthetase as a novel target for differentiation-inducing therapy.

All-trans retinoic acid (ATRA) is one of the most useful drugs in the treatment for acute promyelocytic leukemia (APL), but its adverse effects, which include drug resistance and hypercalcemia are obstacles to achieving complete remission. Our previous study showed that some sesquiterpene lactones (STLs), i.e., helenalin (HE) and parthenolide (PA) but not sclareolide (SC), enhance ATRA-induced differentiation of HL-60 APL cells with no unexpected effects, but the precise mechanism on underlying this synergism is not yet fully understood. In this study, we investigated the distinctive transcriptional profile of cells treated with effective STL compounds, which were identified by comparing the profile with that of cells treated with SC. Genome-wide approaches using cDNA microarrays showed that co-treatment with the differentiation-enhancing STLs HE and PA maximized the transcriptional variation regulated by the suboptimal concentration of ATRA in HL-60 cells. Of the genes of interest, asparagine synthetase was remarkably downregulated by ATRA co-treated with either HE or PA, but not with SC. In an additional analysis for the role of asparagine synthetase, ATRA-mediated HL-60 cell differentiation was enhanced when asparagine in the culture media was depleted by an addition of L-asparaginase, indicating that downregulation of asparagine synthetase gene expression may be involved in the enhanced cell differentiation by STL compounds. These results provide useful insight into differentiation-inducing therapy in the treatment of leukemia.

Suppression of dendritic cells' maturation and functions by daidzein, a phytoestrogen.

Isoflavones are ubiquitous compounds in foods and in the environment in general. Daidzein and genistein, the best known of isoflavones, are structurally similar to 17ß-estradiol and known to exert estrogenic effects. They also evidence a broad variety of biological properties, including antioxidant, anti-carcinogenic, anti-atherogenic and anti-osteoporotic activities. Previously, daidzein was reported to increase the phagocytic activity of peritoneal macrophages and splenocyte proliferation, and to inhibit nitric oxide (NO) production in macrophages. However, its potential impacts on immune response in dendritic cells (DCs), antigen-presenting cells that link innate and adaptive immunity, have yet to be clearly elucidated. In this study, we evaluated the effects of isoflavones on the maturation and activation of DCs. Isoflavones (formononetin, daidzein, equol, biochanin A, genistein) were found to differentially affect the expression of CD86, a costimulatory molecule, on lipopolysaccharide (LPS)-stimulated DCs. In particular, daidzein significantly and dose-dependently inhibited the expression levels of maturation-associated cell surface markers including CD40, costimulatory molecules (CD80, CD86), and major histocompatibility complex class II (I-A(b)) molecule on LPS-stimulated DCs. Daidzein also suppressed pro-inflammatory cytokine production such as IL-12p40, IL-6 and TNF-α, whereas it didn't affect IL-10 and IL-1ß expression. Furthermore, daidzein enhanced endocytosis and inhibited the allo-stimulatory ability of LPS-stimulated DCs on T cells, indicating that daidzein treatment can inhibit the functional maturation of DCs. These results demonstrate that daidzein may exhibit immunosuppressive activity by inhibiting the maturation and activation of DCs.

Differential suppression of heat-killed lactobacilli isolated from kimchi, a Korean traditional food, on airway hyper-responsiveness in mice.

RATIONALE: Probiotics have been shown to be effective in reducing allergic symptoms. However, there are few studies to evaluate the therapeutic effects of lactobacilli on allergen-induced airway inflammation. OBJECTIVE: We investigated whether three heat-killed lactobacilli, Lactobacillus plantarum, Lactobacillus curvatus and Lactobacillus sakei subsp. sakei, isolated from kimchi, exerted inhibitory effects on airway hyper-responsiveness in a murine asthma model. METHODS: Heat-killed lactic acid bacteria were orally administered into BALB/c mice, followed by challenge with aerosolized ovalbumin, after which allergic symptoms were evaluated. RESULTS: Airway inflammation was suppressed in the L. plantarum- and L. curvatus-treated mice. Interleukin (IL)-4 and IL-5 levels were significantly lower in the L. plantarum- and L. curvatus-treated mice than in those treated with L. sakei subsp. sakei. Importantly, heat-killed L. plantarum administration induced Foxp3 expression in intestinal lamina propria cells, and heat-killed L. curvatus induced IL-10 as a way of inducing tolerance. CONCLUSION: Specific strains of lactobacilli isolated from kimchi can effectively suppress airway hyper-responsiveness.

Effects and action mechanism of Diospyros kaki on the differentiation of human leukemia HL-60 cells.

Diospyros kaki Thunb. (Ebenaceae) is widely distributed in North-East Asian countries. Almost all parts of this plant have been traditionally used as medicine. Human promyelocytic leukemia cells differentiate into monocytes or granulocytes when treated with 1,25-dihydroxyvitamin D3 [1,25-(OH)2D3] or all-trans retinoic acid (ATRA). Combination of low doses of ATRA or 1,25-dihydroxyvitamin D3 that do not induce toxicity with another drug is a useful strategy for acute promyelocytic leukemia therapy. Our main aim was to investigate the effect of an acetone extract of D. kaki leaves (KV-1) on HL-60 cell differentiation in combination of ATRA or 1,25-dihydroxyvitamin D3. Treatment of HL-60 cells with zero to 100 microg/ml of KV-1 for 72 h induced a small increase in cell differentiation. Surprisingly, a synergistic induction of differentiation was observed when the HL-60 cells were treated with ATRA or 1,25-(OH)2D3 and the extract. The inhibitors of protein kinase C (PKC) (alpha and betaI) and extracellular signal-regulated kinase (ERK), but not of phosphoinositide 3-kinase (PI3-K) and c-Jun N-terminal kinase (JNK) inhibited the HL-60 differentiation induced by the extract in combination of ATRA or 1,25-(OH)2D3, suggesting that PKC and ERK were involved in the cell differentiation enhancement by the extract. The results indicate that the acetone extract of D. kaki leaves has the ability to enhance HL-60 cell differentiation and suggest that it may be useful in acute promyelocytic leukemia therapy.

The potato developer (D) locus encodes an R2R3 MYB transcription factor that regulates expression of multiple anthocyanin structural genes in tuber skin.

A dominant allele at the D locus (also known as I in diploid potato) is required for the synthesis of red and purple anthocyanin pigments in tuber skin. It has previously been reported that D maps to a region of chromosome 10 that harbors one or more homologs of Petunia an2, an R2R3 MYB transcription factor that coordinately regulates the expression of multiple anthocyanin biosynthetic genes in the floral limb. To test whether D acts similarly in tuber skin, RT-PCR was used to evaluate the expression of flavanone 3-hydroxylase (f3h), dihydroflavonol 4-reductase (dfr) and flavonoid 3',5'-hydroxylase (f3'5'h). All three genes were expressed in the periderm of red- and purple-skinned clones, while dfr and f3'5'h were not expressed, and f3h was only weakly expressed, in white-skinned clones. A potato cDNA clone with similarity to an2 was isolated from an expression library prepared from red tuber skin, and an assay developed to distinguish the two alleles of this gene in a diploid potato clone known to be heterozygous Dd. One allele was observed to cosegregate with pigmented skin in an F(1) population of 136 individuals. This allele was expressed in tuber skin of red- and purple-colored progeny, but not in white tubers, while other parental alleles were not expressed in white or colored tubers. The allele was placed under the control of a doubled 35S promoter and transformed into the light red-colored cultivar Désirée, the white-skinned cultivar Bintje, and two white diploid clones known to lack the functional allele of D. Transformants accumulated pigment in tuber skin, as well as in other tissues, including young foliage, flower petals, and tuber flesh.

Enhancement of 1,25-dihydroxyvitamin D3- and all-trans retinoic acid-induced HL-60 leukemia cell differentiation by Panax ginseng.

Ginseng (Panax ginseng C.A. Meyer) has a wide range of therapeutic uses including cancer treatment. Human promyelocytic leukemia cells differentiate into monocytes or granulocytes when treated with 1,25-dihydroxyvitamin D(3) [1,25-(OH)(2)D(3)] or all-trans retinoic acid (ATRA). Treatment of HL-60 cells with zero to 100 microg/ml of a methanol extract of ginseng for 72 h induced a small increase in cell differentiation. Surprisingly, a synergistic induction of differentiation was observed when HL-60 cells were treated with ATRA or 1,25-(OH)(2)D(3) and the extract. The inhibitors of protein kinase C (PKC) and extracellular signal-regulated kinase (ERK), but not of phosphoinositide 3-kinase (PI3-K), inhibited the HL-60 differentiation induced by the extract in combination with ATRA or 1,25-(OH)(2)D(3), signifying that PKC and ERK were involved in the cell differentiation enhancement by the extract. These results suggest that the ability of a methanol extract of ginseng to enhance the differentiation potential of ATRA or 1,25-(OH)(2)D(3) may improve the ultimate outcome of acute promyelocytic leukemia therapy.

Interferon-alpha enhances artemisinin-induced differentiation of HL-60 leukemia cells via a PKC alpha/ERK pathway.

Interferon-alpha (IFN-alpha) has been used in the treatment of several cancers, including chronic myeloid leukemia. Artemisinin, a sesquiterpene lactone endoperoxide that exists in several medicinal plants, is a well known anti-malarial agent. We previously reported that artemisinin by itself caused a relatively low level of HL-60 cell differentiation. In this study, we investigated the effects of IFN-alpha in combination with artemisinin on cell growth and differentiation in HL-60 leukemia cells. Combination of IFN-alpha and artemisinin synergistically induced the levels of leukemia cell differentiation, although IFN-alpha by itself did not affect cell proliferation and differentiation. The increased cell differentiation by IFN-alpha and artemisinin was significantly suppressed by the inhibitors for protein kinase C (PKC), extracellular signal-regulated kinase (ERK) and jun N-terminal kinase (JNK), but not by the inhibitors for phosphatidylinositol 3-kinase (PI3-K) and p38 mitogen-activated protein kinase (MAPK). Furthermore, co-treatment with IFN-alpha increased levels of PKC alpha and phosphorylated ERK. Taken together, these results indicate the enhancement of artemisinin-induced HL-60 cell differentiation by IFN-alpha through the activation of a PKC alpha/ERK signaling pathway, and suggest a possible use of IFN-alpha and artemisinin in the treatment of leukemic diseases.

Enhancement of 1,25-dihydroxyvitamin D3- and all-trans retinoic acid-induced differentiation of human leukemia HL-60 cells by Phyllostachys nigra var. henonis.

Human myeloid leukemia HL-60 cells are differentiated into monocytic or granulocytic lineage when treated with 1,25-dihydroxyvitamin D(3) [1,25-(OH)(2)D(3)] or all-trans retinoic acid (RA), respectively. In this study, the effect of acetone fraction prepared from bamboo leaf on cell differentiation was investigated in a HL-60 cell culture system. Treatment of HL-60 cells with 50-400 microg/ml acetone fraction of bamboo leaf for 72 hr inhibited cell proliferation and induced a little increase in cell differentiation, as demonstrated by the MTT and nitroblue tetrazolium reduction assay. Interestingly, synergistic induction of HL-60 cell differentiation was observed when the acetone fraction of bamboo leaf was combined with either 5 nM 1,25-(OH)(2)D(3) or 50 nM all-trans RA. Flow cytometric analysis indicated that combinations of 1,25-(OH)(2)D(3) and the acetone fraction of bamboo leaf stimulated differentiation predominantly to monocytes, whereas combinations of all-trans RA and the acetone fraction of bamboo leaf stimulated differentiation predominantly to granulocytes. These results suggest that the acetone fraction of bamboo leaf enhanced leukemia cell differentiation and suggest a possibility of bamboo in the treatment of leukemia.

Inhibition of interleukin-12 production in mouse macrophages via suppression of nuclear factor-kappaB binding activity by Phyllostachys nigra var. henonis.

Pharmacological inhibition of interleukin-12 (IL-12) production may be a therapeutic strategy for preventing development and progression of disease in experimental models of autoimmunity. The acetone fraction prepared from bamboo, Phyllostachys nigra var. henonis, potently inhibited the Lipo polysaccharide (LPS)-induced IL-12 production from RAW264.7 monocytic cell-line in a dose-dependent manner. The repressive effect mapped to a region in the IL-12 gene promoter containing a binding site for NF-kappaB. Furthermore, activation of macrophages by LPS resulted in markedly enhanced binding activity to the NF-kappaB site, which significantly decreased upon addition of the acetone fraction of Phyllostachys nigra var. henonis. This indicated that the acetone fraction inhibited IL-12 production in LPS-activated macrophages via inhibition of NF-kappaB binding activity.

Up-regulation of interleukin-4 production via NF-AT/AP-1 activation in T cells by biochanin A, a phytoestrogen and its metabolites.

Phytoestrogens are naturally occurring compounds derived from plants. Although phytoestrogens exhibit many biological functions including estrogen agonist/antagonist properties, the effect on allergic responses remains unclear. In this study, we investigated whether biochanin A, a phytoestrogen and its metabolites, genistein, p-ethylphenol and phenolic acid, affect production of IL-4, a pro-inflammatory cytokine closely associated with allergic immune responses, in primary CD4(+) T cells and EL4 T lymphoma cells. Biochanin A, genistein and p-ethylphenol significantly enhanced IL-4 production from both CD4(+) T cells and EL4 cells in a dose-dependent manner, while phenolic acid did not. Biochanin A, genistein and p-ethylphenol also enhanced IL-4 gene promoter activity in EL4 cells transiently transfected with IL-4 promoter constructs, but this effect was impaired in EL4 cells transfected with an IL-4 promoter construct deleted of a P4 site carrying NF-AT and AP-1 binding sites. In addition, biochanin A, genistein and p-ethylphenol increased both NF-AT and AP-1 DNA binding activities, indicating that they might enhance IL-4 production via NF-AT/AP-1 activation. Furthermore, biochanin A, genistein and p-ethylphenol increased p38 MAPK phosphorylation and PKC activity, while they did not affect ERK phosphorylation. The enhanced NF-AT DNA binding activities were suppressed by inhibitors for PI3-K and PKC, but not by p38 MAPK inhibitors. In contrast, the enhanced AP-1 DNA binding activities and p38 MAPK phosphorylation were significantly suppressed by specific inhibitors for PKC and p38 MAPK, but not by PI3-K inhibitors. These results demonstrate, for the first time, that biochanin A, genistein and p-ethylphenol enhance IL-4 production in activated T cells by two independent pathways, PI3-K/PKC/NF-AT and PKC/p38 MAPK/AP-1.

Inhibition of interleukin-12 production in mouse macrophages via decreased nuclear factor-kappaB DNA binding activity by myricetin, a naturally occurring flavonoid.

Pharmacological inhibition of interleukin-12 (IL-12) production may be a therapeutic strategy for preventing the development and progression of disease in experimental models of autoimmunity. In this study, the effects of myricetin, a naturally occurring flavonoid present in fruits, vegetables and medicinal herbs, on the production of IL-12 were investigated in mouse macrophages stimulated with lipopolysaccharide (LPS). Myricetin significantly inhibited the LPS-induced IL-12 production from both primary macrophages and the RAW264.7 monocytic cell-line in a dose-dependent manner. The effect of myricetin on IL-12 gene promoter activation was analyzed by transfecting RAW264.7 cells with IL-12 gene promoter/luciferase constructs. The repressive effect was mapped to a region in the IL-12 gene promoter containing a binding site for NF-kappaB. Furthermore, activation of macrophages by LPS resulted in markedly enhanced binding activity to the NF-kappaB site, which significantly decreased upon addition of myricetin, indicating that myricetin inhibited IL-12 production in LPS-activated macrophages via the down-regulation of NF-kappaB binding activity.

Differential involvement of protein kinase C in human promyelocytic leukemia cell differentiation enhanced by artemisinin.

Artemisinin, a sesquiterpene lactone endoperoxide that exists in several medicinal plants, is a well-known anti-malarial agent. In this report, we investigated the effect of artemisinin on cellular differentiation in the human promyelocytic leukemia HL-60 cell culture system. Artemisinin markedly increased the degree of HL-60 leukemia cell differentiation when simultaneously combined with low doses of 1 alpha,25-dihydoxyvitamin D(3) [1,25-(OH)(2)D(3)] or all-trans retinoic acid (all-trans RA). Artemisinin by itself had very weak effects on the differentiation of HL-60 cells. Cytofluorometric analysis and cell morphologic studies indicated that artemisinin potentiated 1,25-(OH)(2)D(3)-induced cell differentiation predominantly into monocytes and all-trans RA-induced cell differentiation into granulocytes, respectively. Extracellular-regulated kinase (ERK) inhibitors markedly inhibited HL-60 cell differentiation induced by artemisinin in combination with 1,25-(OH)(2)D(3) or all-trans RA, whereas phosphatidylinositol 3-kinase (PI3-K) inhibitors did not. Particularly, protein kinase C (PKC) inhibitors inhibited HL-60 cell differentiation induced by artemisinin in combination with 1,25-(OH)(2)D(3) but not with all-trans RA. Artemisinin enhanced PKC activity and protein level of PKC beta I isoform in only 1,25-(OH)(2)D(3)-treated HL-60 cells. Taken together, these results indicate that artemisinin strongly enhanced 1,25-(OH)(2)D(3)- and all-trans RA-induced cell differentiation in which PKC is differentially involved in arteminisin-mediated enhancement of leukemia cell differentiation.

Involvement of nuclear factor-kappaB in the inhibition of interleukin-12 production from mouse macrophages by baicalein, a flavonoid in Scutellaria baicalensis.

Pharmacological inhibition of interleukin-12 (IL-12) production may be a therapeutic strategy for preventing development and progression of disease in experimental models of autoimmunity. In this study we investigated the effects of baicalein, a flavonoid present in the root of Scutellaria baicalensis, on the production of IL-12 from mouse macrophages stimulated with lipopolysaccharide (LPS). Baicalein potently inhibited the LPS-induced IL-12 production from both primary macrophages and RAW264.7 monocytic cell-line in a dose-dependent manner (the IC50 values were 43.7 and 17.4 microM, respectively). The effect of baicalein on IL-12 gene promoter activation was analyzed by transfecting RAW264.7 cells with IL-12 gene promoter/luciferase constructs. The repressive effect mapped to a region in the IL-12 gene promoter containing a binding site for NF-kappaB. Furthermore, activation of macrophages by LPS resulted in markedly enhanced binding activity to the NF-kappaB site, which significantly decreased upon addition of baicalein, indicating that baicalein inhibited IL-12 production in LPS-activated macrophages via inhibition of NF-kappaB binding activity.

Synergistic induction of 1,25-dihydroxyvitamin D(3)- and all-trans-retinoic acid-induced differentiation of HL-60 leukemia cells by yomogin, a sesquiterpene lactone from Artemisia princeps.

Many anti-inflammatory agents are known to significantly enhance the terminal differentiation of some cancer cells such as leukemia cells. In this study, the effect of yomogin, a eudesmane sesquiterpene lactone isolated from Artemisia princeps with anti-inflammatory activity, was investigated in human promyelocytic leukemia HL-60 cells. Yomogin by itself induced small increases in cell differentiation, with less than 19 % of the cells attaining a differentiated phenotype. Importantly, yomogin synergistically enhanced differentiation of HL-60 cells in a dose-dependent manner when combined with either 5 nM 1,25-dihydroxyvitamin D(3) [1,25-(OH)(2) D(3)] or 50 nM all- trans retinoic acid (all- trans RA). Cytofluorometric analysis and morphologic studies indicated that the combinations of yomogin and 1,25-(OH)(2) D(3) stimulated differentiation to monocytes whereas the combinations of yomogin and all- trans RA stimulated differentiation to granulocytes. These results suggest that yomogin may be useful in combination with 1,25-(OH)(2) D(3) or all- trans-RA in the differentiation therapy for myeloid leukemias. Abbreviations. 1,25-(OH)(2) D(3) :1,25-dihydroxyvitamin D(3) FITC:fluorescein isothiocyanate NBT:nitroblue tetrazolium RA:retinoic acid PE:phytoerythrin

Effects of resveratrol-related hydroxystilbenes on the nitric oxide production in macrophage cells: structural requirements and mechanism of action.

NF-kappaB that plays an important role in iNOS expression is one of the targets of various potential anti-inflammatory agents including resveratrol. Resveratrol contains a structural similarity with estrogen, and there has been speculation about resveratrol as estrogen agonist. In this study, the mechanism and structural requirements of resveratrol and related hydroxystilbenes for the inhibition of LPS-induced nitric oxide production were studied in macrophage cells (RAW 264.7 and J774) by comparing its effect on LPS-induced NF-kappaB translocation and nitric oxide production, and by considering the possibility of involvement of an estrogen receptor. LPS-induced nitric oxide production was inhibited only when cells were treated with resveratrol prior to stimulation with LPS, suggesting that resveratrol does not affect the enzyme itself. A higher concentration of resveratrol than needed for the inhibition of nitric oxide production was required for the inhibition of NF-kappaB mobilization or iNOS expression. Estrogen and diethylstilbesterol, an estrogen agonist, caused only weak inhibition of nitric oxide production, and the effects of resveratrol were not noticeably blocked by ICI-182780, an estrogen antagonist. Structure-activity analysis of resveratrol and nine hydroxystilbenes suggests that the structural balance between oxygen functional groups on the benzene rings is important for their activity. Our results suggest that resveratrol might act on other cellular targets as well as NF-kappaB at the initial stage of gene expression. Unique structural features of hydroxystilbenes are needed for suppression of nitric oxide production and it is unlikely that estrogen receptor is involved in it.