Sulfatides inhibit adhesion, migration, and invasion of murine melanoma B16F10 cell line in vitro.

Endogenous sulfatide, such as 3-sulfated galactosylceramide (3-sulfatide) has been reported to be involved in neuronal development and regulation of tumor cell metastasis. Recently, a new 6-sulfated glucosylceramide (6-sulfatide) has been isolated from the ascidian, Ciona intestinalis. To determine the antitumor function of the new sulfatide, we examined the effects of synthetic 6-sulfatide and 3-sulfatide on the metastatic features of a murine melanoma cell line, B16F10.

Knockdown of proteolipid protein 2 or focal adhesion kinase with an artificial microRNA reduces growth and metastasis of B16BL6 melanoma cells.

Proteolipid protein 2 (PLP2) promotes the metastasis of B16F10 cells in an experimental metastasis model. However, the effect of PLP2 on spontaneous metastasis has yet to be demonstrated, and whether PLP2 may become a new therapeutic target for malignant tumors is as yet unknown. In this study, PLP2 or focal adhesion kinase (FAK) microRNA-based short hairpin RNAs (miRNAs) were used as target molecules to specifically reduce the expression of PLP2 or FAK in B16BL6 cells.

Irradiation effect on osteoclastogenesis stimulated by breast cancer cells.

To examine the effects of carbon ion and gamma ray irradiation on cancer-induced osteoclastogenesis, mouse calvaria MC3T3-E1 cells were cultured with conditioned medium from irradiated and non-irradiated MCF7 human breast cancer cells. The authors examined RANKL and OPG mRNA expression in osteoblastic MC3T3-E1 cells following treatment with conditioned MCF7 medium. Co-cultured MC3T3-E1 and bone marrow cells treated with conditioned medium from irradiated MCF7 cells showed decreased numbers of osteoclasts, assessed using TRAP staining.

Licochalcones suppress degranulation by decreasing the intracellular Ca2+ level and tyrosine phosphorylation of ERK in RBL-2H3 cells.

Mast cells play a key role in allergic inflammation by releasing various mediators, such as histamine, serotonin, leukotrienes and cytokines. A signaling cascade of events activated by stimulation with antigens contributes to the regulation of mast cell degranulation. While various anti-inflammatory and anti-allergic drugs have been developed that inhibit degranulation of mast cells, the inhibitory mechanism has been poorly understood.

The fixed structure of Licochalcone A by alpha, beta-unsaturated ketone is necessary for anti-inflammatory activity through the inhibition of NF-kappaB activation.

Glycyrrhiza inflata has been used as a traditional medicine with anti-inflammatory activity. Previously, we reported that a major component, Licochalcone A, potently inhibited TNFalpha-induced NF-kappaB activation by inhibiting IKKbeta activation. In this study, we investigated whether the fixed structure of Licochalcone A by alpha, beta-unsaturated ketone is required for its inhibitory effect of NF-kappaB activation.

Proteolipid protein 2 is associated with melanoma metastasis.

The metastasis of malignant tumor cells from the primary tumor to distant sites in the body is a complex process. To identify genes that may be essential for metastasis, we established poorly metastatic mouse melanoma cells, namely Y925F-mutated FAK-transfected cells (Y925F cells), from the highly metastatic mouse melanoma cell line B16F10, and performed expression analyses. The expression of phospholipid protein 2 (PLP2) was markedly down-regulated in the Y925F cells.

STAT5 activation is critical for the transformation mediated by myeloproliferative disorder-associated JAK2 V617F mutant.

It has been well established that disruption of JAK2 signaling regulation is involved in various hematopoietic disorders; however, the detailed mechanism by which abnormal activation of JAK2 exhibits transforming activity remains to be elucidated. Here, to clarify the functional role of the erythropoietin receptor (EpoR) and its downstream transcription factor STAT5 in the abnormal activation of JAK2-induced hematopoietic diseases, we generated a stable transfectant of Ba/F3 cells expressing EpoR and analyzed the molecular mechanism of how JAK2 mutation induces cell growth disorder. JAK2 V617F mutant exhibited transforming activity when EpoR was coexpressed.

Licochalcone A potently inhibits tumor necrosis factor alpha-induced nuclear factor-kappaB activation through the direct inhibition of IkappaB kinase complex activation.

Glycyrrhiza inflata has been used as a traditional medicine with anti-inflammatory activity; however, its mechanism has not been fully understood. Licochalcone A is a major and biogenetically characteristic chalcone isolated from G. inflata.

The polycythemia vera-associated Jak2 V617F mutant induces tumorigenesis in nude mice.

The somatic Jak2 mutation (V617F) was identified in most patients with polycythemia vera (PV). Here, we show that the activating Jak2 V617F mutant completely protected Ba/F3 cells from cytokine withdrawal-induced apoptotic cell death. Interestingly, Ba/F3 cells expressing Jak2 V617F mutant induced rapid tumorigenesis in nude mice, leading to rapid death.

Glycyrrhiza inflata-derived chalcones, Licochalcone A, Licochalcone B and Licochalcone D, inhibit phosphorylation of NF-kappaB p65 in LPS signaling pathway.

Licorice root has been used as a traditional medicine for the treatment of gastric ulcer, bronchial asthma and inflammation. Licochalcone A is a major component of Xinjiang licorice, Glycyrrhiza inflata. Previously we showed that Licochalcone A significantly inhibited LPS-induced NF-kappaB transcriptional activation by abrogating the phosphorylation of NF-kappaB p65 at serine 276.

The acute lymphoblastic leukemia-associated JAK2 L611S mutant induces tumorigenesis in nude mice.

JAK2 plays important roles in the regulation of a variety of cellular processes including cell migration, proliferation, and protection from apoptosis. Recently the L611S point mutation in JAK2 has been identified in a child with acute lymphoblastic leukemia. Here we analyzed the mechanism by which JAK2 exhibits its oncogenicity.

Licochalcone A significantly suppresses LPS signaling pathway through the inhibition of NF-kappaB p65 phosphorylation at serine 276.

Licorice root, Glycyrrhiza inflata, has been used as a traditional medicine for the treatment of bronchial asthma and inflammation; however, the mechanism of its anti-inflammatory activity has not been clarified. Here, we investigated the effect of Licochalcone A, a major component of G. inflata, on the LPS signaling pathway.

Dermatophagoides farinae extract induces severe atopic dermatitis in NC/Nga mice, which is effectively suppressed by the administration of tacrolimus ointment.

Atopic dermatitis (AD) is a chronic inflammatory skin disease, which is accompanied by marked increases in the levels of inflammatory cells, including mast cells and eosinophils as well as T cells and macrophages. To investigate the expression pattern of chemokines in AD, a house dust mite, Dermatophagoides farinae extracts (DfE)-induced NC/Nga AD model was developed in mice, and this model was used to determine the expression levels of chemokines in atopic lesions using DNA microarrays and RT-PCR. When NC/Nga mice were repeatedly treated with DfE for 4 to 7 weeks on the back skin, the mRNA expression levels of CCL20/LARC, CCL24/eotaxin-2, CCL17/TARC, and CCL11/eotaxin-1 were markedly induced and lesser of CCL2/MCP-1, within the inflammatory lesion of the back skin.

TRAF6 negatively regulates TNFalpha-induced NF-kappaB activation.

TNF receptor-associated factor 6 (TRAF6) is an essential adaptor protein for the Interleukin-1 (IL-1) signaling pathway; however, its role in the signaling of another proinflammatory cytokine, tumor necrosis factor alpha (TNFalpha, has not been explored. Interestingly, we observed that TNFalpha-induced expression of IL-6, CXCL1 and granulocyte macrophage colony stimulating factor (GM-CSF) were significantly enhanced in TRAF6-deficient MEFs. Compared to those observed in wild-type MEFs, TNFalpha-induced IkappaB kinase (IKK) activation and IkappaBalpha degradation were enhanced in TRAF6-deficient MEFs.

Licochalcone A is a potent inhibitor of TEL-Jak2-mediated transformation through the specific inhibition of Stat3 activation.

Aberrant activation of Jak/Stat signaling causes a number of hematopoietic disorders and oncogenesis, and therefore the effective inhibitors of the Jak/Stat signaling pathway may be therapeutically useful. TEL-Jak2 gene fusion, which has been identified in human leukemia, encodes a chimeric protein endowed with constitutive tyrosine kinase activity. Expression of TEL-Jak2 protects Ba/F3 cells from IL-3 withdrawal-induced apoptotic cell death and leads to IL-3-independent growth.

Celecoxib potently inhibits TNFalpha-induced nuclear translocation and activation of NF-kappaB.

Celecoxib is a specific inhibitor of cyclooxygenase 2 (COX2). While it has been used for the treatment of chronic inflammatory conditions, including rheumatoid arthritis, its detailed anti-inflammatory mechanism has not been clarified. Here, we found that Celecoxib potently inhibited TNFalpha-induced transcriptional activity and DNA binding activity of NF-kappaB; however, Celecoxib had no effect on TNFalpha-induced IKK activation and degradation of IkappaBalpha and IkappaBbeta, suggesting that it inhibited NF-kappaB activation via suppressing downstream of IKK activation and IkappaBs degradation.

Mutation of Y925F in focal adhesion kinase (FAK) suppresses melanoma cell proliferation and metastasis.

This study focused on the role of focal adhesion kinase (FAK), a cytoplasmic tyrosine kinase important for many cellular processes, in the proliferation, adhesion, and invasion of melanoma cells in vitro and in vivo. We found that the Y925F-mutation of FAK in B16F10 melanoma cells suppressed metastasis in an experimental model, which correlated well with decreased extracellular matrix dependent proliferative capability, adhesive, migrational, and invasive capabilities. Transduction of the mutation Y925F resulted in a down-regulation of the phosphorylation of Erk, the expression of VEGF, and the association of FAK with paxillin.

TRAF6 is a critical signal transducer in IL-33 signaling pathway.

IL-33 has been shown to induce Th2 responses by signaling through the IL-1 receptor-related protein, ST2L. However, the signal transduction pathways activated by the ST2L have not been characterized. Here, we found that IL-33-induced monocyte chemoattractant protein (MCP)-1, MCP-3 and IL-6 expression was significantly inhibited in TNF receptor-associated Factor 6 (TRAF6)-deficient MEFs.

A synthetic glycosphingolipid-induced antiproliferative effect in melanoma cells is associated with suppression of FAK, Akt, and Erk activation.

Numerous studies have demonstrated the participation of glicolipids in signal transduction and the regulation of melanoma cell growth and apoptosis. Hoping to discover new anticancer drugs, we have synthesized ten glycolipids found in various invertebrates that do not have sialic acids. These compounds were tested for antiproliferative effects on a melanoma cell line, B16F10.

Synthetic studies on glycosphingolipids from Protostomia phyla: syntheses and biological activities of amphoteric glycolipids containing a phosphocholine residue from the earthworm Pheretima hilgendorfi.

Two types of amphoteric glycosphingolipid found in the earthworm Pheretima hilgendorfi, PC(-->6)-beta-d-Galp-(1-->6)-beta-d-Galp-(1-->1)Cer (1) and PC(-->6)-beta-d-Galp-(1-->6)-beta-d-Galp-(1-->6)-beta-d-Galp-(1-->1)Cer (2), and their derivatives (4, 5) were synthesized. These were examined for their ability to enhance production of interleukin-8 (IL-8), a potent inflammatory cytokine involved in neutrophil chemotaxis, in a TNFalpha-stimulated granulocytic HL-60 cells. Compounds 1 and 2 were found to be potent enhancers of IL-8 production.

Production and regulation of eotaxin-2/CCL24 in a differentiated human leukemic cell line, HT93.

When a human leukemic cell line, HT93 was incubated with all-trans retinoic acid (ATRA), IL-5, or both, this cell line was differentiated into eosinophic lineage, in that an eosinophilic specific granule proteins, major basic protein (MBP) and eosinophil peroxidase (EPO) appeared. Both CD11b and CC chemokine receptor, CCR3 expression were upregulated, while CD71 expression was downregulated by ATRA or ATRA+IL-5. Concomitantly, marked production of eotaxin-2/CCL24 was observed, but no production of eotaxin-1/CCL11 and eotaxin-3/CCL26 was detected.

Suppression of endoplasmic reticulum stress-induced caspase activation and cell death by the overexpression of Bcl-xL or Bcl-2.

Continuous endoplasmic reticulum (ER) stress, such as the accumulation of unfolded proteins, results in cell death and relates to the pathogenesis of some neurodegenerative diseases. Treatment of brefeldin A, an inhibitor of transport between the ER and Golgi complex, induced cell death during 24 h, which accompanied activation of caspase-2, caspase-3 and caspase-9, starting at 12 h and increasing time-dependently up to 28 h. Caspase-2 was expressed and activated in not only mitochondria and cytosol, but also in the microsomal fraction containing ER and Golgi.

MEK-ERK is involved in SUMO-1 foci formation on apoptosis.

Small ubiquitin-related modifier (SUMO) modification appears to regulate the activity, intracellular localization, and stability of the targeted proteins. To explore the relationship among sumoylation, antitumor reagent, and apoptosis, we treated green fluorescence protein (GFP)-SUMO-1-overexpressed K562 cells (K562/GFP-SUMO-1) with mitoxantrone (MIT) as an antitumor reagent. By the treatment with MIT, GFP-SUMO-1 formed foci in nuclei.

Focal adhesion kinase determines the fate of death or survival of cells in response to TNFalpha in the presence of actinomycin D.

We speculated that focal adhesion kinase (FAK) might play a critical role in the TNFalpha-induced cell death. In this study, we found that FAK-/- cells are more sensitive to TNFalpha-induced apoptosis in the presence of actinomycin D (Act D) compared to FAK+/- cells. Prosurvival pathways are activated by the rapid recruitment of complex I, comprising TNFR1, TRADD, RIP and TRAF2, which leads to the activation of the NF-kappaB pathway.

TNF-receptor associated factor 6-deficient fibroblast is sensitive to the TNF-alpha-induced cell death: involvement of reactive oxygen species.

Tumor necrosis factor receptor (TNFR)-associated factor 6 (TRAF6) has mainly been involved in signaling from CD40 and IL-1 receptor family. While TNF-alpha exerts various biological effects including cell death, the role of TRAF6 in the TNF-alpha signaling remains to be unclear. Here, we demonstrated that murine embryonic fibroblasts (MEFs) derived from TRAF6 knockout (TRAF6KO) mice have increased sensitivity to actinomycin D plus TNF-alpha-induced cell death compared with wild-type MEF.