OBJECTIVETo investigate the MEK and ERK expression and their relationship with clinicopathological parameters in human breast carcinoma, and the effect of preoperative chemotherapy on MEK and ERK protein expression.

METHODSSamples were obtained from 56 patients with breast carcinoma and 8 patients with benign tumors. Sixteen of the 56 patients received preoperative chemotherapy. Western blot and immunohistochemistry were used to measure the expression of MEK1, MEK2 and ERK1, ERK2 protein.

RESULTSMEK2 and ERK1, ERK2 protein levels were increased in breast carcinoma tissue compared with those in adjacent normal tissues (t = 7.244, 5.959, 3.735, P < 0.01) and benign tumors (t = 2.206, P < 0.05). The levels of MEK1 were decreased. The expression of MEK2 protein in ER negative patients was higher than that in ER positive ones. MEK2 protein levels were lower in patients who received preoperative chemotherapy than in those who did not.

CONCLUSIONOverexpression of MEK-ERK may play an important role in the development of human breast carcinoma. MEK and ERK protein expressions are inhibited by preoperative chemotherapy.

Adult ; Aged ; Blotting, Western ; Breast Neoplasms ; diagnosis ; enzymology ; metabolism ; Female ; Humans ; Immunohistochemistry ; MAP Kinase Kinase 1 ; MAP Kinase Kinase 2 ; MAP Kinase Signaling System ; physiology ; Middle Aged ; Mitogen-Activated Protein Kinase 1 ; metabolism ; Mitogen-Activated Protein Kinase 3 ; Mitogen-Activated Protein Kinase Kinases ; metabolism ; Mitogen-Activated Protein Kinases ; metabolism ; Prognosis ; Protein Kinases ; metabolism ; Protein-Serine-Threonine Kinases ; metabolism ; Protein-Tyrosine Kinases ; metabolism

WEE1 is an important factor for histone transcription, chromosome condensation and regulation of cell cycle progression. WEE1 kinase can phosphorylate Cdc2 and down-regulate Cdc2 kinase activity. It can regulate G2 to M phase transition and cell mitosis. It plays a key role in chromosome condensation delay and histone synthesis, suggesting the important functions of WEE1 in the occurrence and development in cancer. At present, a multiple WEE1 inhibitors have been discovered. A great progress has been made in combination of WEE1 inhibitors with DNA damage treatment (chemotherapy or radiotherapy), which makes WEE1 an important target in cancer treatment.
CDC2 Protein Kinase ; metabolism ; Cell Cycle ; Cell Cycle Proteins ; metabolism ; DNA Damage ; Histones ; metabolism ; Humans ; Neoplasms ; metabolism ; Nuclear Proteins ; metabolism ; Phosphorylation ; Protein-Tyrosine Kinases ; metabolism

Mer is one member of Axl receptor tyrosine kinase family, and its ligand Gas6 can stimulate activity of Mer receptor tyrosine kinase after binding it, and then activate the downstream signal transduction pathway, Mer participates in cell inflammation, apoptosis, tumorigenesis, thrombosis and hemostasis. Rencet advances of study on Mer function were reviewed, and its potential prospects of antithrombosis and antitumor were discussed in this article.
Animals ; Fibrinolytic Agents ; Humans ; Intercellular Signaling Peptides and Proteins ; metabolism ; Proto-Oncogene Proteins ; genetics ; metabolism ; Receptor Protein-Tyrosine Kinases ; genetics ; metabolism ; Signal Transduction ; c-Mer Tyrosine Kinase

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

Animals ; Colonic Neoplasms ; metabolism ; pathology ; Focal Adhesion Kinase 1 ; Focal Adhesion Protein-Tyrosine Kinases ; Humans ; Integrins ; metabolism ; Neoplasm Invasiveness ; Neoplasm Metastasis ; Protein-Tyrosine Kinases ; metabolism ; Rectal Neoplasms ; metabolism ; pathology ; Signal Transduction

A membrane glycoprotein CD4 functions as a co-receptor of a T lymphocyte. The co-receptor function has been attributed to a protein tyrosine kinase, p56lck, which is activated upon CD4 binding to MHC molecule. In this study, we present evidences that one of the pathways through which CD4 transmits its signal is cytoskeleton association of p56lck tyrosine kinase as well as CD4 itself. Cytoskeletal association of both proteins is inhibited by a tyrosine kinase inhibitor, genistein, indicating that tyrosine protein kinase activation is important for cytoskeletal association of CD4 and p56lck. Cytoskeletal association of these proteins by CD4 cross-linking is not affected by inhibitors of protein kinase C nor PI3-kinase. Taken together, these results suggest that CD4 cross-linking activates a tyrosine kinase which then induces the simultaneous association of CD4 and p56lck with cytoskeleton.
Antigens, CD4/metabolism* ; Antigens, CD4/drug effects ; Cross-Linking Reagents ; Cytoskeleton/metabolism* ; Down-Regulation (Physiology) ; Enzyme Inhibitors/pharmacology ; Flow Cytometry ; Genistein/pharmacology ; Human ; Lymphocyte Specific Protein Tyrosine Kinase p56(lck)/metabolism* ; Lymphocyte Specific Protein Tyrosine Kinase p56(lck)/antagonists & inhibitors ; Phosphorylation/drug effects ; Protein Binding ; Tetradecanoylphorbol Acetate/pharmacology ; Tumor Cells, Cultured ; Tyrosine/metabolism

BACKGROUNDMüller cells in the mammalian retina normally express low levels of glial fibrillary acidic protein (GFAP); however, its expression is upregulated in response to the loss of retinal neurons. The change in expression of GFAP is one of the earliest indicators of retinal damage and is correlated with the time course of disease. The aim of this study was to investigate the time course of degeneration and the expression of GFAP in the retina of mer knockout mice.

METHODSA total of 30 mer knockout mice, aged from 15 - 20 days to 1 year and 32 age-matched wild type mice as controls were tested. Immunohistochemistry was used to show the expression of GFAP in the central and peripheral retina of mer knockout and control mice at postnatal age of 15 days (P15d), 20 days (P20d), 4 weeks (P4w), 6 weeks (P6w), 8 weeks (P8w), 3 months (P3m), 6 months (P6m) and 1 years (P1y).

RESULTSThe expression of GFAP in the central and peripheral retina of wild type mice was limited to the retinal ganglion cell and nerve fiber layers. In the central retina of mer knockout mice, GFAP expression was upregulated at P4w and GFAP immunolabelling penetrates across the entire thickness of the retina at P8w; whereas in the peripheral retina, the GFAP expression was upregulated at P20d and GFAP immunolabelling penetrates the entire retina after P4w.

CONCLUSIONSIncreased expression of GFAP in Müller cells of mer knockout mice occur at P20d in the peripheral retina and P4w in the central retina. GFAP expression in Müller cells appears to be a secondary response to the loss of retinal neurons. Increased expression of GFAP may occur prior to any detectable morphological changes in the retina. This study suggests that the loss of retinal neurons may begin in the early stages of retinitis pigmentosa, prior to the discovery of any morphological changes in the retina.

Animals ; Glial Fibrillary Acidic Protein ; metabolism ; Immunohistochemistry ; Mice ; Mice, Knockout ; Proto-Oncogene Proteins ; genetics ; Receptor Protein-Tyrosine Kinases ; genetics ; Retina ; metabolism ; pathology ; Retinitis Pigmentosa ; genetics ; metabolism ; c-Mer Tyrosine Kinase

Cell migration plays an important role in repair of injury, angiogenesis, cancer metastasis and so on. In this paper the effects of basic fibroblast growth factor (bFGF) of different concentrations on ECV-304 cell migration, and the dynamic changes in focal adhesion kinase (FAK) were observed. The relationship between FAK and cell migration induced by bFGF was studied. A ECV-304 cell scratch wound model was established and the images of cell migration were quantitatively measured using a computer-assisted videomicroscopic system. The dynamic changes in FAK content (Western blot), FAK activity (immunoprecipitation plus Western blot) and FAK mRNA (RT-PCR) were measured in vitro. The expression of integrin alpha3 was investigated using immunocytochemical staining (ABC method). The results showed that bFGF produced a dual-phase regulatory effect on ECV-304 migration when the cell confluent areas reached 90%-95% in culture. It was found that compared with the control group (0 ng/ml bFGF), the cell migration was stimulated (P<0.05), inhibited (P<0.05) and unchanged when the cultured cells were treated with bFGF at the concentrations of 5, 10 and 15 ng/ml, respectively. The content and activity of FAK protein were markedly up-regulated in 5 ng/ml bFGF group and down-regulated in 15 ng/ml bFGF group, respectively. FAK mRNA expression came to the peak in 5 ng/ml bFGF group after 6 h culture and there was a significant difference compared with the control group. In various experimental groups there were no significant differences in the expression of integrin alpha3 compared with the control group according to the immunocytochemical staining. The results mentioned above suggest that different concentrations of bFGF have a dual-phase effect on the migration of cultured ECV-304 cells, which correlates positively with FAK content, activity and mRNA in cultured ECV-304 cell scratch wound model. The FAK plays an important role in the signal transduction pathway of cell migration induced by bFGF, while bFGF can regulate the content of FAK in ECV-304 cells at gene transcription level.
Cell Movement ; physiology ; Cells, Cultured ; Endothelium, Vascular ; cytology ; Fibroblast Growth Factor 2 ; physiology ; Focal Adhesion Kinase 1 ; Focal Adhesion Protein-Tyrosine Kinases ; Humans ; Integrin alpha3 ; metabolism ; Protein-Tyrosine Kinases ; metabolism ; RNA, Messenger ; metabolism ; Umbilical Veins ; cytology

Receptor- and nonreceptor-mediated stimuli produce increases in both PKCdelta tyrosine phosphorylation and activity in rat parotid acinar cells and other cells. In vivo and in vitro increases and decreases in tyrosine phosphorylation resulted in increases and decreases, respectively, of PKCdelta activity. These studies demonstrated that increases in PKCdelta activity by G protein-coupled receptors and other stimuli were controlled by alterations in tyrosine phosphorylation.
Animal ; Enzyme Activation/physiology ; Isoenzymes/metabolism* ; Male ; Parotid Gland/enzymology* ; Phosphorylation ; Protein Kinase C/metabolism* ; Rats ; Rats, Sprague-Dawley ; Tyrosine/metabolism*

To verify the spectrum of CD99-expressing lymphoid malignancy, an immunohistochemical study for CD99 was carried out in 182 cases of non-Hodgkin's lymphoma, including 21 lymphoblastic lymphomas, 11 small lymphocytic lymphomas, 9 mantle cell lymphomas, 12 follicular lymphomas, 37 diffuse large B cell lymphomas, 18 Burkitt's lymphomas, 28 NK/T-cell lymphomas, 8 angioimmunoblastic T-cell lymphomas, 23 peripheral T-cell lymphomas, unspecified, and 15 systemic anaplastic large cell lymphomas. CD99 was positive in all T-lymphoblastic lymphomas and in 60% of B-lymphoblastic lymphomas. Majority of T and NK cell lymphomas were negative for CD99, except anaplastic large cell lymphomas (ALCLs). Eight of 15 cases (54%) of ALCLs reacted with anti CD99 antibody. Seven of 10 (70%) ALK positive ALCLs expressed CD99, whereas only 1 of 5 (20%) ALK negative ALCLs were positive. Of the mature B-cell lymphomas, 5.4% (2/37) of diffuse large B cell lymphomas and 11.1% (2/18) of Burkitt's lymphomas expressed CD99. In conclusion, CD99 is infrequently expressed in mature B and T cell lymphomas, except ALK-positive ALCL. High expression of CD99 in ALK-positive ALCL is unexpected finding and its biologic and clinical significances have yet to be clarified.
Antigens, CD/*metabolism ; Blotting, Western ; Cell Adhesion Molecules/*metabolism ; Humans ; Immunohistochemistry ; Lymphoma, Large-Cell/enzymology/*immunology/pathology ; Lymphoma, Non-Hodgkin/enzymology/*immunology/pathology ; Protein-Tyrosine Kinase/immunology/*metabolism