This study was aimed to investigate the expression of beta-catenin in leukemic cell lines and its relationship with pathogenesis of leukemia, semi-quantitative RT-PCR and Western blot were performed to detect the expression of beta-catenin in a panel of 15 human hematopoietic cell lines (U937, KG1a, Jurkat, K562, Namalwa, HEL, HUT78, Raji, Daudi, CEM, LCL-H, HL-60, NB4, J6-1, Ramos). Immunocytochemistry was performed in some of these cell lines to detect the location of beta-catenin. The results showed that the beta-catenin gene was widely expressed in most leukemic cell lines in various degree, the high expression of beta-catenin was found is U937, KG1a, Jurkat, K562 and Namalwa cells, middle expression of beta-catenin was observed in HEL, HUT78, Raji, Daudi and CEM cells, lower expression of beta-catenin was observed in LCL-H, HL-60, NB4, J6-1 and Ramos cells. The expression level of beta-catenin protein was identical to the expression level of beta-catenin mRNA. The expression of beta-catenin could be found in nuclei of all cells mentioned above, but their levels were different between them. Abundant beta-catenin also could be observed in nuclei of some leukemic cells by immunocytochemistry. It is concluded that overexpression of beta-catenin in leukemia cells, as a key mediator of Wnt signaling transduction pathway, indicates that the Wnt signaling transduction pathway may be aberrantly activated in leukemia.
Humans ; Leukemia ; metabolism ; pathology ; RNA, Messenger ; metabolism ; Signal Transduction ; Tumor Cells, Cultured ; beta Catenin ; metabolism

BACKGROUNDProstate stromal cells are known to regulate epithelial growth as well as support and maintain epithelial function. However, how stromal cells regulate epithelial cells and what differences among various histological/pathological prostate stromal cells in prostate cancer progression still remain unclear. This study aimed to investigate the different phenotypes of human various histological/pathological prostate stromal cells, and their role in tumor promotion.

METHODSThe different phenotypes of the human normal prostatic peripheral zonal primary stromal cells (NPPF), transitional zonal primary stromal cells (NPTF), and prostate cancer associated primary stromal cells (CAF) were examined with growth curves and Annexin V-fluorescein isothiocyanate (FITC) assay. The different effects on prostate cancer cell line C4-2B by NPPF, NPTF, and CAF were examined with MTT assay and Annexin V-FITC assay. The gene expression of different histological/pathological prostate stromal cells was profiled by microarray and hierarchical cluster analysis.

RESULTSThe growth rate of NPPF, NPTF and CAF gradually increased, followed by decreasing apoptosis. In vitro stromal-C4-2B cell line co-culture models, the proliferation and apoptosis of C4-2B cell line were differently affected by human various histological/pathological prostate stromal cells. CAF showed the most powerful effect to C4-2B cell line, as opposed to a weakest effect of NPTF. Microarray and hierarchical cluster analysis showed that the differentially expressed genes of CAF and NPPF were less than NPPF and NPTF, or CAF and NPTF. This was consistent with clinical observations that prostate cancer mostly derived from the peripheral zone and does not usually occur in the transitional zone.

CONCLUSIONNPPF, NPTF and CAF possess extremely different biological characteristics and gene expression, which may play an important role in genesis and development of prostate cancer.

Adult ; Apoptosis ; Cell Line, Tumor ; Cell Proliferation ; Cells, Cultured ; Cluster Analysis ; Flow Cytometry ; Humans ; Immunohistochemistry ; Male ; Prostate ; cytology ; Prostatic Neoplasms ; pathology ; Stromal Cells ; cytology ; metabolism ; Tumor Cells, Cultured

As CD40 transduces activation signals involved in inflammatory and immune disorders, we explored the expression and response to CD40 engagement in human glioma cell lines in this study. The CD40 expression in BT-325 and U251 cells was flow cytometrically detected. The cells were incubated with srhCD40L for 72 h to assess its effects on cell growth in vitro. TNF-α expression was quantified by real-time PCR, and protein expression was analyzed by ELISA. The I-κb mRNA was detected by RT-PCR. I-κB expression decreased after stimulation with 1 μg/mL srhCD40L, but it was upregulated after the cells were pretreated with CD40 antibody. srhCD40L significantly inhibited the proliferation of the CD40+ human glioma cells. The stimulation of CD40+ glioma cells with soluble CD40L (CD154) up-regulated the expression of TNF-α at both mRNA and protein levels. We are led to conclude that CD40L/CD40 could inhibit human glioma cells through I-κb signaling pathway. Interferon-γ can augment CD40 expression and the inhibitory effect of CD40 ligand on cell growth in vitro. These results suggest that srhCD40L may benefit the therapy strategy of glioma.
CD40 Antigens ; metabolism ; CD40 Ligand ; metabolism ; Cell Proliferation ; Cells, Cultured ; Glioma ; genetics ; metabolism ; pathology ; Humans ; NF-kappa B ; metabolism ; Signal Transduction ; physiology ; Tumor Cells, Cultured

This study was purposed to investigate the connexin 43 (Cx43) expression level in acute leukemia bone marrow stromal cells (ABMSCs) and normal bone marrow stromal cells (NBMSCs), and to explore the difference in communicating functions between these cells. The Cx43 expression levels of ABMSCs and NBMSCs were detected by using immunohistochemistry and computer gray scale assay, and the difference of gap junction intercellular communication (GJIC) was examined through dry transfer technique. The results showed that expression level of Cx43 in ABMSCs was lower than that in NBMSCs and its function of GJIC in ABMSCs was also weaker than that in NBMSCs. It is concluded that cell-cell communication function is lowered in ABMSCs.
Acute Disease ; Bone Marrow Cells ; cytology ; metabolism ; pathology ; Cell Communication ; physiology ; Connexin 43 ; metabolism ; Gap Junctions ; metabolism ; Humans ; Leukemia ; metabolism ; Stromal Cells ; cytology ; metabolism ; Tumor Cells, Cultured

We found previously that ACh can significantly inhibit the proliferation of cultured human pituitary adenoma cells. In order to make a further investigation of the mechanism of the inhibitory effect of ACh on the proliferation of pituitary adenoma cells, we observed the levels of protein kinase C (PKC), [Ca(2+)](i) and cAMP/cGMP in cultured pituitary adenoma cells after treatment with ACh. The results demonstrate that (1) compared with control, PMA, a PKC activator, increased the activity of cytoplasm, membrane and total PKC in human pituitary adenoma cells. However, after a 15-min treatment with ACh (10 micromol/L), a significant reduction of the activity of cytoplasm, membrane and total PKC in human pituitary adenoma cells was observed, and the reduction effect could be blocked by atropine. (2) The level of [Ca(2+)](i) of single adenoma cells was found to decrease immediately on the addition of ACh (10 micromol/L), which could also be blocked by atropine. (3) ACh increased the amount of cAMP in the cytoplasm of human pituitary adenoma cells, but had no effect on that of cGMP. These data provide an important clue to explore the molecular mechanisms of the inhibitory effect of ACh on the proliferation of pituitary adenoma cells, and suggest that the modulating effect of ACh on the proliferation of pituitary adenoma cells results from the interactions of several cellular signaling pathways.
Acetylcholine ; physiology ; Adenoma ; metabolism ; pathology ; Calcium ; metabolism ; Cyclic AMP ; metabolism ; Cyclic GMP ; metabolism ; Humans ; Pituitary Neoplasms ; metabolism ; pathology ; Protein Kinase C ; metabolism ; Signal Transduction ; physiology ; Tumor Cells, Cultured

OBJECTIVETo test the telomerase SiRNA on telomerase mRNA and on KB cell growth of oral squamous cell carcinoma.

METHODSWe synthesized 21-nucleotide SiRNA duplexes with symmetric 2-nucleotide 3' overhangs corresponding to the target sequence (2 657 approximately 2 675 nucleotide downstream of the start codon) of telomerase mRNA. Telomerase activity, cell proliferation, cell cycle and apoptosis were measured after transfection.

RESULTSTwenty one-nucleotide small interfering RNA (SiRNA) duplexes specifically suppressed expression of endogenous telomerase mRNA in human oral squamous carcinoma KB cells. This inhibitory effect lasted only for about 48 h after transfection. Telomerase activity reduction corresponded to the mRNA suppression. Cell proliferation decreased by 30% at 48 h after transfection and lasted for 120 h after treatment. This inhibitory effect resulted from the block of G(1) to S transition. Apoptosis was not involved in this process.

CONCLUSIONSSiRNA is a powerful tool for studying gene function and can be used as gene-specific therapeutics.

Apoptosis ; Carcinoma, Squamous Cell ; metabolism ; pathology ; Cell Proliferation ; Humans ; KB Cells ; Mouth Neoplasms ; metabolism ; pathology ; RNA, Messenger ; biosynthesis ; RNA, Small Interfering ; genetics ; Telomerase ; genetics ; metabolism ; Tumor Cells, Cultured

The mechanical properties of tumor cells adhering to extracellular matrix (ECM) are closely related with their invasion and metastesis. In this study we investigated the adhesive mechanical properties between hepatocellular carcinoma cells(HCC) and the collagen I coated surfaces from the viewpoint of cell cycle by coupling cellular biology and cellular mechanics, using micropipette aspiration and cell synchronization technique. The results showed that the synchronous G1 and S phase HCC cells were achieved by use of thymine-2-desoryriboside, colchicines sequential blockage method and double thymine-2-desoryriboside blockage method, and that the synchronous rates of G1 and S phase HCC amounted to 74.09% and 90.39% respectively. Within the ranges of dosing and timing in this study, the adhesion of HCC cells to collagen I displayed dose dependent and time dependent patterns. S phase cells had small force of adhesion to collagen I as compared with G1 phase and controlled cells(P<0.001), which suggested that G1 phase HCC may play an important role in the step of invading interstitial connective tissue in the metastasis pathway of HCC through blood circulation. These are of significance to unveiling the mechanism of HCC metastasis.
Animals ; Cell Adhesion ; Cell Cycle ; Collagen Type I ; metabolism ; Liver Neoplasms, Experimental ; metabolism ; pathology ; Neoplasm Metastasis ; Rats ; Tumor Cells, Cultured

Cell Adhesion Molecules ; metabolism ; Cells, Cultured ; Endothelial Cells ; cytology ; metabolism ; physiology ; Humans ; Integrins ; metabolism ; Membrane Proteins ; metabolism ; Neoplasms ; metabolism ; pathology ; Organ Specificity ; Platelet Endothelial Cell Adhesion Molecule-1 ; metabolism ; Saphenous Vein ; cytology ; Tumor Cells, Cultured ; Umbilical Veins ; cytology

OBJECTIVETo study lysosomes involvement in the degradation of ricin A chain.

METHODSA lysosome-targeted singal KFERQ was added to the C terminus of rRTA by DNA recombinant technology. A pKK223.3 expression system in E. coli was used to produce recombinant ricine A chain (rRTA) and rRTA-KFERQ. Recombinant proteins were purified by affinity chromatography using Blue-Sepharose 6B. The cytotoxicity of recombinant proteins was measured by the MTT method.

RESULTSRecombinant RTA-KFERQ was 49.87%, 54.18% and 88.68% less cytotoxic than RTA itself on the three cell lines HEPG2, Hela and A549, respectively.

CONCLUSIONLysosomes can degrade, but not completely inactivate RTA in different cells, suggesting cells may have other degradation pathways for RTA.

Chromatography, Affinity ; Escherichia coli ; genetics ; metabolism ; HeLa Cells ; Humans ; Lung Neoplasms ; pathology ; Lysosomes ; metabolism ; Recombinant Proteins ; genetics ; isolation & purification ; metabolism ; Ricin ; genetics ; metabolism ; Tumor Cells, Cultured

The purpose of this study was to investigate the growth characteristics and the expression level of integrin mRNA of the cultured bone marrow mesenchymal stem cells (BMMSCs) from patients with chronic myeloid leukemia (CML) in myeloid crisis (MC), and explore the role of BMMSCs in pathogenesis of CML. Five CML patients were enrolled in experimental group, five healthy persons were used as control. BMMSCs were cultured in vitro. The morphology of BMMSCs was observed every day and the growth curve were portrayed, and the ability of cell proliferation were detected according to the daily results of cell counting. Total RNA was extracted from third and fourth passages of BMMSCs, The expression of integrins mRNA of BMMSCs were measured by real-time PCR. The results showed that the BMMSCs of experimental and control groups had no difference in growth characterisctics, but the expression of integrins mRNA of the BMMSCs was higher in CML patients than in normal control group (p < 0.05). It is concluded that the abnormally high expression of integrins of BMMSC from the CML patients take part in pathogenesis of CML.
Adult ; Blast Crisis ; metabolism ; Bone Marrow Cells ; metabolism ; pathology ; Cell Proliferation ; Female ; Humans ; Integrins ; genetics ; metabolism ; Leukemia, Myelogenous, Chronic, BCR-ABL Positive ; metabolism ; pathology ; Male ; Mesenchymal Stromal Cells ; metabolism ; pathology ; Middle Aged ; RNA, Messenger ; genetics ; metabolism ; Tumor Cells, Cultured