OBJECTIVETo study the proto-oncogene RON mediated aggression of Raji cells and the inhibitory effects by monoclonal antibody Zt/f2 (2f2).

METHODSThe effects of RON ligand macrophage stimulating protein (MSP) (2.0 nmol/L) and inhibitory Zt/f2 (2F2) (2.0 nmol/L) antibody on proliferation of RON positive Raji cells after treatment for 24 and72 hours were detected by MTT method, colony formation units (CFU) of Raji cells by methylcellulose semi solid culture, Raji cells apoptosis and cell cycle analysis by AnnexinV/PI double staining, expression of RON, apoptosis-related proteins, and cyclins by Western blot.

RESULTS(1)Compared with the cell viability (1.0) and counts of CFU (103.6±7.0) in control group, Raji cells after MSP treatment had better viability (1.35±0.20) and CFU counts (133.7±10.4) (P<0.05), but worse viability (0.68±0.11) and CFU counts (66.3±6.1) after Zt/f2 (2F2) treatment (P<0.05). (2)Percentage of Raji cells apoptosis after Zt/f2 (2F2) antibody treatment (12.16±2.33)% was significantly increased than the control (2.89±1.03)% (P<0.05). The percentage of Raji cells arrested in G0/G1 phase was increased after Zt/f2 (2F2) antibody treatment as compared to the control [ (54.96 ±3.70)% vs (39.10±2.30)%, (P<0.05) ]. (3) High-level of RON phosphorylation and β-catenin expression activated by MSP could be inhibited significantly by Zt/f2 (2F2), which also up-regulated the expression of caspase-3, caspase-8, caspase-9 and PARP and down-regulated anti-apoptotic MCL-1 gene and inhibitor of apoptosis protein XIAP expression, accompanied with G1 phase protein changes accordingly.

CONCLUSIONMSP could aggravate Raji cells proliferation. Inversely, Zt/f2 (2F2) could inhibit proliferation and induce apoptosis by inhibition of RON phosphorylation and up-regulation of apoptosis related proteins.

Apoptosis ; drug effects ; Cell Line, Tumor ; Cell Proliferation ; drug effects ; Humans ; Proto-Oncogenes ; Receptor Protein-Tyrosine Kinases ; metabolism

OBJECTIVEFMS-like tyrosine kinase 3 (FLT3) is a receptor tyrosine kinase that is constitutively activated in (70-90)% pediatric patients with acute myeloid leukemia (AML) and appears to confer an adverse prognosis. Although several FLT3-selective small molecule inhibitors and antibodies were developed with varied degrees of success, to address the specificity and resistance, new approaches for specifically targeted FLT3 are needed and RNA interference is a promising choice. The aim of the present study was to investigate the efficacy of suppression of FLT3 induced by small hairpin interfering RNA (shRNA) on myeloproliferation and apoptosis in an acute monocytic leukemia (AMOL) cell line THP-1.

METHODSFLT3-targeted small hairpin interfering RNA (FLT3-shRNA) was designed and synthesized by transcription system in vitro was transfected into THP-1 cells. Firstly FLT3 mRNA level was detected by semi-quantitative RT-PCR and FLT3 protein level was detected by flow cytometry (FCM) to verify the efficacy on FLT3-shRNA interference at 48 h after transfection. Cell growth viability was measured at 24 h, 48 h and 72 h after treatment with CCK-8. The distribution of cell cycle was assayed by FCM, and apoptosis was analyzed by DNA Ladder and Annexin V-FITC Staining at 48 h.

RESULTSFLT3 targeted shRNAs was synthesized successfully and the concentration of 15 nmol/L for 48 h could obtain desirable downregulation of FLT3 expression, the inhibitory percentages of FLT3 mRNA and protein were (72.95 +/- 2.07)% and (65.39 +/- 5.57)%, respectively. The suppression of FLT3 induced by FLT3-shRNA resulted in marked inhibition of cell growth and the inhibitory percentages were (36.66 +/- 3.67)% at 48 h, (35.56 +/- 0.73)% at 72 h. FLT3-shRNA induced the inhibition of cell cycle from G(0)/G(1) phase to S phase, the percentage of sub-G(0)/G(1) phase (65.71 +/- 4.47)% was higher than those in the PBS-control group (52.23 +/- 2.98)%, NC-shRNA control group (51.81 +/- 1.44)%, P < 0.01; the percentage of S phase (25.11 +/- 2.70)% was lower than those in the PBS-control group (34.41 +/- 4.07)% and NC-shRNA control group (32.50 +/- 1.46)%, P < 0.05. Furthermore treatment with FLT3-shRNA for 48 h resulted in clear apoptosis ladder, the percentage of early apoptosis detected by Annexin V-FITC was (18.59 +/- 2.07)% which was significantly higher than that in the PBS-control group (4.00 +/- 0.50)% and the NC-shRNA control group (6.06 +/- 0.70)%, P < 0.001.

CONCLUSIONThe suppression of FLT3 induced by the shRNA can effectively inhibit cell proliferation, and apoptosis induction on THP-1 cells, which indicates that this approach may bear the therapeutic potential on childhood AMOL.

Apoptosis ; drug effects ; genetics ; Cell Proliferation ; drug effects ; Child ; Humans ; Leukemia, Monocytic, Acute ; enzymology ; pathology ; Protein-Tyrosine Kinases ; metabolism ; RNA Interference ; physiology ; RNA, Small Interfering ; pharmacology ; Receptor Protein-Tyrosine Kinases ; metabolism ; fms-Like Tyrosine Kinase 3 ; metabolism

Intracellular signal transduction plays an important role in the process of cellular metabolism, segmentation, differentiation, biological behaviour and cell death. Overactive signal transduction relates to tumor development and progression. Signaling pathways operated by protein tyrosine kinases (PTKs) will be illuminated here briefly. The Ras/Raf/MAPK and PI-3K/Akt pathways through receptor protein tyrosine kinases (RTKs), the Src, Bcr-Abl and JAK/STAT pathways by non-receptor protein tyrosine kinases (nrPTKs) are shown separately. Antitumor agents targeting the key proteins involved in the above five signalling routes are also summarized in this review.
Animals ; Antineoplastic Agents ; pharmacology ; Humans ; Phosphatidylinositol 3-Kinases ; metabolism ; Protein-Tyrosine Kinases ; metabolism ; Receptor Protein-Tyrosine Kinases ; metabolism ; STAT Transcription Factors ; metabolism ; Signal Transduction ; drug effects ; ras Proteins ; metabolism ; src-Family Kinases ; metabolism

OBJECTIVETo investigate the relationship between mTOR signaling pathway and ALK-positive lymphoid cell lines.

METHODSThe expression of the downstream effector proteins of mTOR were analyzed by Western blot before and after Karpas299, BaF3/NPM-ALK and BaF3 cell lines treated with rapamycin. Effect of rapamycin on cell proliferation was detected by MTT assay. FACS was used to analyze apoptosis and cell cycles.

RESULTSmTOR signaling phosphoproteins, p-p70S6K and p-4E-BP1 were highly expressed in ALK(+) Karpas299, BaF3/NPM-ALK and parental BaF3 cell lines, and they were dephosphorylated after 1 h withdrawal of IL-3 in BaF3 cells. After 48 h exposure to 10 nmol/L rapamycin, p-p70S6K and p-4E-BP1 proteins expression were decreased, and mainly for the former. The relative inhibitory rate to its control cells was 24.4% in Karpas299, 37.8% in BaF3/NPM-ALK and 61.6% in BaF3. The apoptotic ratio was increased from (11.97 +/- 0.11)% to (15.87 +/- 0.62)% in Karpas299 (P < 0.05), from (3.23 +/- 0.11)% to (7.67 +/- 0.49)% in BaF3 (P < 0.05) and from (1.90 +/- 0.47)% to (2.80 +/- 0.27)% in BaF3/NPM-ALK (P > 0.05). The fraction of G(1) phase cells increased from (37.63 +/- 1.91)% to (69.77 +/- 5.44)% in BaF3/NPM-ALK, from (31.13 +/- 2.51)% to (40.70 +/- 1.47)% in Karpas299 and (53.57 +/- 2.22)% to (63.70 +/- 1.20)% in BaF3 (P < 0.05).

CONCLUSIONNPM-ALK kinase can activate mTOR signaling pathway. Rapamycin can inhibit the proliferation of ALK(+) lymphoid cells by blocking mTOR signaling pathway and inducing cell cycling arrest at G(1) phase.

Animals ; Apoptosis ; drug effects ; Cell Cycle ; drug effects ; Cell Line, Tumor ; Cell Proliferation ; drug effects ; Humans ; Intracellular Signaling Peptides and Proteins ; metabolism ; Lymphoma ; metabolism ; pathology ; Mice ; Protein-Serine-Threonine Kinases ; metabolism ; Protein-Tyrosine Kinases ; metabolism ; Receptor Protein-Tyrosine Kinases ; Ribosomal Protein S6 Kinases, 70-kDa ; metabolism ; Signal Transduction ; drug effects ; Sirolimus ; pharmacology ; TOR Serine-Threonine Kinases

Human neuroblastoma SH-SY5Y cell is a cloned cell line which has many attractive features for the study of neuronal proliferation and neurite outgrowth, because it has receptors for insulin, IGF-I and PDGF. Gangliosides are sialic acid containing glycosphingolipids which form an integral part of the plasma membrane of many mammalian cells. They inhibit cell growth mediated by tyrosine kinase receptors and ligand-stimulated tyrosine kinase activity, and autophosphorylation of EGF(epidermal growth factor) and PDGF receptors. The experiment was designed to study the effects of GM1 ganglioside on growth of human neuroblastoma SH-SY5Y cells stimulated with trophic factor in vitro. The cells were plated in Eagle's minimum essential medium without serum. The number and morphologic change of SH-SY5Y cells were evaluated in the serum free medium added GM1 ganglioside with insulin or PDGF. SH-SY5Y cells were maintained for six days in serum-free medium, and then cultured for over two weeks in serum-free medium containing either insulin or PDGF. The effect of insulin on cell proliferation developed earlier and was more potent than that of PDGF. These proliferative effects were inhibited by GM1 ganglioside, and the cells showed prominent neurites outgrowth. These findings suggest that GM1 ganglioside inhibits the cell proliferation mediated by tyrosine kinase receptors and directly induces neuritogenesis as one of the neurotrophic factors.
Cell Differentiation/drug effects ; Cell Division/drug effects ; G(M1) Ganglioside/*pharmacology ; Humans ; Insulin/pharmacology ; Neuroblastoma ; Neurons/cytology/*drug effects ; Platelet-Derived Growth Factor/pharmacology ; Receptor Protein-Tyrosine Kinases/drug effects ; Tumor Cells, Cultured

Silibinin, from milk thistle (Silybum marianum), is a flavonolignan with anti-oxidative and anti-inflammatory properties. It has been therapeutically used for the treatment of hepatic diseases in China, Germany and Japan. Recently, increasing evidences prove that silibinin is also a potent antitumor agent, and the major anti-tumor mechanism for silibinin is the prominent inhibition of the activities of receptor tyrosine kinases (RTKs) and their downstream signal molecules in a variety of tumor cell lines, such as epidermal growth factor receptor 1 (EGFR) and insulin-like growth factor 1 receptor (IGF-1R) signaling pathways. Meanwhile, the evidences that silibinin selectively scavenges hydroxyl free radical (*OH) and specifically inhibits the action of nuclear factor kappaB (NF-kappaB) provide more complicated explanations for its antioxidant and anti-inflammatory effects. Some new findings such as that silibinin attenuating the cognitive deficits induced by amyloid beta protein (Abeta) peptide through its antioxidative and anti-inflammatory properties is valuable to broad the medical prospect of silibinin. In this review, we discuss the molecular pharmacological mechanisms of silibinin, focusing on its inhibition of tyrosine kinases, actions of antioxidation, free radical scavenging, immunoregulation and anti-inflammation.
Amyloid beta-Peptides ; metabolism ; Animals ; Anti-Inflammatory Agents ; pharmacology ; Antineoplastic Agents, Phytogenic ; pharmacology ; Antioxidants ; pharmacology ; Enzyme Activation ; Free Radical Scavengers ; pharmacology ; Humans ; Milk Thistle ; chemistry ; Molecular Structure ; NF-kappa B ; metabolism ; Protein-Tyrosine Kinases ; metabolism ; Reactive Oxygen Species ; metabolism ; Receptor Protein-Tyrosine Kinases ; metabolism ; Receptor, Epidermal Growth Factor ; metabolism ; Receptor, IGF Type 1 ; metabolism ; Signal Transduction ; drug effects ; Silymarin ; chemistry ; isolation & purification ; pharmacology

OBJECTIVETo establish an in vitro homogeneous time-resolved fluorescence immunoassay method for high throughput screening of protein tyrosine kinase (PTK) inhibitors.

METHODSSpecific fluorescence signals at 670 and 612 nm were measured by multifunctional microplate reader when the fluorescence was emitted through a resonance energy transfer between fluorescent materials (EuK and XL-665). The inhibitory activity of Sunitinib, a standard PTK inhibitor, on vascular endothelia growth factor receptor 2 (VEGFR-2) kinase activity was investigated.

RESULTSA homogeneous time-resolved fluorescence immunoassay was established for high throughput screening of PTK inhibitor. In this system, the concentrations of VEGFR-2, adenosine triphosphate (ATP) and poly-peptide substrate were 5 ng/microl, 100 micromol/L and 1 micromol/L, respectively. Sunitinib inhibited VEGFR-2 kinase activity with an IC50 value of 86.7 nmol/L, which was close to the values tested using other methods.

CONCLUSIONThe homogeneous time-resolved fluorescence immunoassay we established can be easily used for high throughput screening of PTK inhibitors.

Fluoroimmunoassay ; methods ; High-Throughput Screening Assays ; methods ; Indoles ; pharmacology ; Peptides ; metabolism ; Phosphorylation ; drug effects ; Protein Kinase Inhibitors ; pharmacology ; Protein-Tyrosine Kinases ; antagonists & inhibitors ; metabolism ; Pyrroles ; pharmacology ; Time Factors ; Vascular Endothelial Growth Factor Receptor-2 ; antagonists & inhibitors ; metabolism

5-Aryl-4-cyano-1H-1, 2, 3-triazoles bearing a variety of substituting groups on 5-phenyl were synthesized. Their structures were established by MS, IR and 1H NMR spectra. The crystal structures of compounds 3f and 3m were determined by X-ray diffraction analysis. The active H of the triazole was on 1-N from the crystal structures. The compounds, designed as HER2 tyrosine kinase inhibitors, were screened for bioactivity of growth-inhibition of breast cancer MDA-MB-453 cells. The lowest IC50 value of inhibiting HER2 tyrosine kinase phosphorylation in breast cancer cells is 6.6 micromol x L(-1). The inhibiting-growth of breast cancer cells was enhanced from electron-drawing groups joining 5-phenyl on the triazole.
Breast Neoplasms ; metabolism ; pathology ; Cell Line, Tumor ; Cell Proliferation ; drug effects ; Crystallization ; Crystallography, X-Ray ; Female ; Humans ; Phosphorylation ; Protein-Tyrosine Kinases ; antagonists & inhibitors ; metabolism ; Receptor, ErbB-2 ; antagonists & inhibitors ; metabolism ; Triazoles ; chemical synthesis ; chemistry ; pharmacology

Objective: To study the effects of muskolibanum combination on the proliferation and differentiation of prostate stem cells. METHODS: We cultured prostate epithelial cells and urogenital sinus mesenchymal (UGSM) cells from 7－10 d old C57BL/6 mice and 16－18 d old pregnant C57BL/6 mice, transplanted the mixed suspension of the two types of cells under the kidney envelope of SCIDCB.17 male mice, and harvested the transplants 30 days later. We randomly divided the SCIDCB.17 mice into four groups to be treated intragastrically with musk (n = 8), olibanum (n = 8), musk+olibanum (n = 7), and normal saline (blank control, n = 8)) respectively, all for 14 days. Then we collected the kidney tissue for observation of the morphology of the glandular tubes and differentiation of different subsets of stem cells by HE staining and determination of the expressions and distribution of P63, CD133, CD117 and Sca1 by immunohistochemistry and Western blot. RESULTS: A system was successfully established for the isolation and mixed culture of Sca1 Lin+ CD49f+ (LSC) cells of prostate stem cells and UGSM cells of the mouse embryonic prostate. Immunohistochemistry showed positive expressions of P63, CD133, Sca1, and CD117 in the prostatic acinar epithelia and proved the presence of prostatic acinar epithelial structure in the transplants. Compared with the blank control group, the expressions of CD133, Sca1 and CD117 were significantly increased in the musk, olibanum, and musk+olibanum groups (P< 0.05), higher in the musk+olibanum than in the musk or olibanum group (P< 0.05), and their protein expressions were even more elevated in the musk+olibanum group (P< 0.01), with statistically significant difference from the olibanum group (P< 0.05). CONCLUSIONS The combination of musk and olibanum can improve the proliferation and differentiation of prostate stem cells.
Animals ; Cell Differentiation ; drug effects ; Cell Proliferation ; drug effects ; Drug Therapy, Combination ; Epithelial Cells ; cytology ; drug effects ; Fatty Acids, Monounsaturated ; pharmacology ; Female ; Frankincense ; pharmacology ; Male ; Mesenchymal Stem Cells ; cytology ; drug effects ; Mice ; Mice, Inbred C57BL ; Mice, SCID ; Pregnancy ; Prostate ; cytology ; Random Allocation ; Receptor Protein-Tyrosine Kinases ; Receptors, Cholinergic ; Stem Cells ; cytology ; drug effects

OBJECTIVETo investigate the influence of Qingkailing (QKL) on learning and memory abilities, global neurotransmitter and phosphatidylinositol 3-kinase/protein kinase B (PI3K/AKT) signaling pathway of senescence accelerated mouse-prone/8 (SAMP8) mice with Alzheimer's dementia (AD).

METHODSSAMP mice were modeled and divided into the model group, the QKL group and the doneppezil hydrochloride group, all treated for 90 days. And a control group was set up with senescence accelerated mouse-resistance/1 (SAMR1) mice. Morris water maze was used to test the learning and memory abilities of mice; contents of acetylcholine (Ach) and monoamine neurotransmitters in brain were measured by HPLC; levels of Grb2-associated binder-1 (Gab1), AKT and phospho-serine/threonine protein kinase B (PAKT473) were evaluated by Western-blot.

RESULTSCompared with the control group, in the model group, the average escape latency detected by hidden platform trial and reverse trial on the 3rd day was higher (P < 0.01); levels of Ach, 5-hydroxytryptamine (5-HT) and Gab1 were lower (P < 0.01, P < 0.05 and P < 0.01), respectively. As compared with the model group, the escape latency (within the 2nd to 5th day) decreased (P < 0.01), levels of Ach and 5-HT increased (P < 0.05), and Gab1 protein expression increased (P < 0.01) in the QKL treated group after treatment, in addition, the level of phosphorylated AKT protein significantly increased (P < 0.05).

CONCLUSIONQKL could improve the learning and memory ability of AD model mice, which is probably related to its function in increasing cerebral Ach, 5-HT and activating PI3K/AKT pathway.

Alzheimer Disease ; drug therapy ; physiopathology ; Animals ; Disease Models, Animal ; Drugs, Chinese Herbal ; pharmacology ; therapeutic use ; Female ; Learning ; drug effects ; Male ; Memory ; drug effects ; Mice ; Mice, Mutant Strains ; Phosphatidylinositol 3-Kinases ; metabolism ; Phytotherapy ; Proto-Oncogene Proteins ; metabolism ; Receptor Protein-Tyrosine Kinases ; metabolism ; Signal Transduction ; drug effects