OBJECTIVETo investigate the effects of artificial ligand of peroxisome proliferators activated receptors (PPARs), rosiglitazone (RGZ) and all trans-retinoic acid (ATRA) on human myeloma cell line growth in vitro and in vivo.

METHODSU266 and RPMI 8226 cells were treated with different concentration of RGZ in the presence or absence of ATRA and the results were studied by 3H-TdR thymidine incorporation (for cells proliferation), Annexin V-PI staining and caspase-3 activity assay (for cells apoptosis), RT-PCR (for FLIP, XIAP and survivin mRNA expression), and tumor formation test in BALB/c nude mice.

RESULTSExposure to RGZ induced proliferation inhibition in a dose-dependent manner in both U266 (r = 0.991, P < 0.01) and RPMI 8226 cells (r = 0.961, P < 0.01). A combination of RGZ with ATRA could enhance the inhibition effect (P < 0.001 in U266, P < 0.01 in RPMI8226). 10 micromol/L of RGZ induced apoptosis of (9.8 +/- 1.7)% in U266 cells and (10.7 +/- 3.3)% in RPMI8226 cells, in a time and dose dependent manner and combined with ATRA intensified the apoptosis induction effects (P < 0.01 in both cell lines). The FLIP, XIAP and survivin mRNAs were expressed in both cell lines and their levels decreased significantly after cultured with RGZ. The addition of RGZ + ATRA in the culture further decreased the levels. Caspase-3 activity increased substantially with the increase of RGZ concentration and the addition of RGZ + ATRA in the culture medium showed similar synergism effect on caspase-3 activation (P < 0.01). The xenograft of U266 cells in BALB/c nude mice were inhibited by RGZ and so did more by the combination of RGZ and ATRA (P < 0.01).

CONCLUSIONThe down-regulation of FLIP, XIAP and Survivin induced by RGZ can activate caspase-3, whereby induced apoptosis and proliferation inhibition in myeloma cells. ATRA can enhance these effects of RGZ.

Animals ; Antineoplastic Agents ; pharmacology ; Apoptosis ; drug effects ; Caspase 3 ; metabolism ; Cell Line, Tumor ; Cell Proliferation ; drug effects ; Female ; Humans ; Inhibitor of Apoptosis Proteins ; metabolism ; Mice ; Mice, Inbred BALB C ; Mice, Nude ; Multiple Myeloma ; metabolism ; pathology ; Signal Transduction ; drug effects ; Thiazolidinediones ; pharmacology ; Tretinoin ; pharmacology

OBJECTIVETo investigate the effects of PPARgamma ligand (rosiglitazone, RGZ) as well as combined with all trans-retinoic acid (ATRA) on human myeloma cells and try to explore the possible mechanism.

METHODSHuman myeloma cell lines U266 and RPMI-8226 cells were treated with RGZ in the presence or absence of ATRA. Cell proliferation was evaluated by [(3)H] thymidine incorporation, cell cycle distribution and CD49e expression were analyzed by flow cytometry, morphology changes were evaluated by Wright-Giemsa staining, and p27(Kip1) and p21(Waf1) expression was detected by Western blotting.

RESULTSThe exposure to RGZ induced proliferation inhibition in both cell lines in a dose-dependent manner. After cultured with 5 micromol/L RGZ, the proportion of U266 and RPMI-8226 cells in phase G(0)/G(1) was (45.2 +/- 6.7)% and (40.3 +/- 7.3)%, respectively (P < 0.05). The proportion of the cells in phase G(2)/M and S was (52.2 +/- 7.4)% and (57.4 +/- 9.5)%, respectively (P < 0.05). These changes were more evident when the RGZ concentration was increased to 10 micromol/L. A combination of RGZ with ATRA enhanced the growth inhibition and cell cycle arrest effects of RGZ. The RGZ-treated myeloma cells displayed morphological characteristics of cell differentiation, and more evident signs of differentiation were observed when RGZ was combined with ATRA. These changes were confirmed by the detection of CD49e expression. The expression of p27(Kip1) and p21(Waf1) in myeloma cells was up-regulated by RGZ and this change was more apparent when RGZ was used in combination with ATRA.

CONCLUSIONRGZ can induce cell cycle arrest and cell differentiation in myeloma cells which maybe caused by up-regulation of p27(Kip1) and p21(Waf1) expression. ATRA can enhance these effects of RGZ on multiple myeloma cells and combined use of these two drugs may show a synergistic effect on myeloma cells.

Cell Cycle ; drug effects ; Cell Line, Tumor ; Cell Proliferation ; drug effects ; Cyclin-Dependent Kinase Inhibitor p21 ; metabolism ; Cyclin-Dependent Kinase Inhibitor p27 ; Dose-Response Relationship, Drug ; Drug Synergism ; Humans ; Integrin alpha5 ; metabolism ; Intracellular Signaling Peptides and Proteins ; metabolism ; Multiple Myeloma ; metabolism ; pathology ; PPAR gamma ; agonists ; Thiazolidinediones ; administration & dosage ; pharmacology ; Tretinoin ; pharmacology ; Up-Regulation

BACKGROUNDRosuvastatin has been claimed to be more potent than other statins in its ability to lower the low-density lipoprotein (LDL) cholesterol levels. This study aimed to investigate the clinical efficacy of rosuvastatin in LDL cholesterol lowering therapy for new or switched hyperlipidaemic Chinese patients.

METHODSThis study was a retrospective one in patients who took rosuvastatin in the outpatient clinics of Prince of Wales Hospital during the period of July 1, 2004 to June 30, 2005. The prescribing pattern, the utilization pattern and the side effect profile were recorded. Attainment of lipid goals for each patient was assessed according to the National Cholesterol Education Program Adult Treatment Panel (NCEP ATP) III guidelines.

RESULTSA total of 261 Chinese patients (mean age (64.8 +/- 12) years; 55.6% male) were recruited into the study. The mean LDL-cholesterol level was (3.50 +/- 1.29) mmol/L prior to Rosuvastatin and (2.30 +/- 1.73) mmol/L after Rosuvastatin treatment (P < 0.0001). Rosuvastatin raised the LDL-cholesterol goal achievement rate from 28.0% to 74.3% in all patients combined (P < 0.0001) and from 11.0% to 79.0% for statin naive patients (P < 0.0001). Approximately 4% of patients developed side effects including myalgia, elevated liver enzymes, and dizziness.

CONCLUSIONRosuvastatin was effective in improving LDL-cholesterol goal attainment and lowering LDL-cholesterol and triglyceride (TG) levels in either newly started or switched patients.

Adult ; Aged ; Cholesterol, LDL ; blood ; Female ; Fluorobenzenes ; adverse effects ; therapeutic use ; Humans ; Hydroxymethylglutaryl-CoA Reductase Inhibitors ; therapeutic use ; Male ; Middle Aged ; Pyrimidines ; adverse effects ; therapeutic use ; Retrospective Studies ; Rosuvastatin Calcium ; Sulfonamides ; adverse effects ; therapeutic use

OBJECTIVETo investigate the relative effects of degree and distribution of body fat with several cardiovascular disease (CVD) risk factors in elderly Chinese subjects.

METHODSOne hundred and thirty-five elderly Chinese individuals (age range, 60-65 y) without any history of significant renal, hepatic or cardiac disease were recruited. Seated blood pressure, anthropometric and fasting plasma biochemical parameters were measured. Student's t-test was used to compare the differences in biochemical and anthropometric markers between cohorts.

RESULTSMales were heavier (64.6 +/- 8.6, 57.2 +/- 8.2kg, P < 0.001), taller (1.65 +/- 0.06, 1.51 +/- 0.05 m, P < 0.001) and their greater body fat was predominantly deposited centrally (Waist-to- hip ratio, 0.91 +/- 0.06, 0.88 +/- 0.07, P < 0.05). Females were more generally obese with increased body mass index (BMI, 23.8 +/- 4.6, 25.0 +/- 3.5 kg/m2, P < 0.05) and percentage body fat [26.3% (24.5%-28.1%) vs 37.2% (36.0%-38.9%), P < 0.001] than the males. However, despite an 11% higher proportion of body fat in females, no significant differences were identified in blood pressure, lipid profile, indices of insulin resistance or albumin-to-creatinine ratios.

CONCLUSIONIt is likely that central adiposity contributes disproportionately to these metabolic disorders in males even though they are much leaner than elderly Chinese females.

Adult ; Aged ; Body Mass Index ; Cardiovascular Diseases ; etiology ; Female ; Humans ; Male ; Middle Aged ; Obesity ; complications ; Risk Factors

OBJECTIVETo observe the effect of rosiglitazone (RGZ) and all-trans-retinoic acid (ATRA) on the growth of myeloma xenograft in nude mice and to explore the influence of RGZ and ATRA on VEGF expression and angiogenesis in the tumor.

METHODSVEGF gene expression in myeloma cell line U266 cells was analyzed by semi-quantitative RT-PCR after incubation with RGZ, ATRA, or RGZ + ATRA for 24 h. Myeloma xenograft was established by subcutaneous injection of 10(7) U266 cells in the scapula area of 4-week old nude mice. 7 days later, the nude mice were administered with RGZ, ATRA or RGZ + ATRA, respectively, by intraperitoneal injection once every day for 21 days. The control mice were given equal volume of normal saline instead of the drug. On the 21(st) day of treatment, the mice were sacrificed and the tumors were taken off, and the tumor volume and weight were measured. The tumors were examined by histopathology with HE staining, and microvessel density (MVD), CD34 and VEGF expression in the tumors were analyzed by immunohistochemical staining.

RESULTSVEGF mRNA was highly expressed in U266 cells and was decreased in a dose-dependent manner after incubation with RGZ. The VEGF mRNA level was further more decreased after RGZ + ATRA treatment. Xenografts of U266 cells were developed in all nude mice. The volume and weight of xenografts in the RGZ group were (785 ± 262) mm(3) and (1748 ± 365) mg, respectively, significantly lower than those of the control group (both P < 0.01). More significant inhibition was in the RGZ + ATRA group, (154 ± 89) mm(3) and (626 ± 102) mg, respectively, both were P < 0.05 vs. the RGZ group. RGZ inhibited the angiogenesis in U266 xenografts and immunohistochemical staining showed that the tumor MVD and VEGF expression were significantly decreased by RGZ treatment, and further more inhibited in the RGZ + ATRA group. VEGF protein was expressed in all xenografts in the nude mice. Its immunohistochemical staining intensity was 2.20 ± 0.40 in the control group, significantly higher than that of 1.48 ± 0.37 in the RGZ group (P < 0.01), and that of RGZ + ATRA group was 0.58 ± 0.26, further significantly lower than that of the RGZ group (P < 0.01). CD34 was expressed in all xenografts, most highly in the control group and lowest in the RGZ + ATRA group. The microvessel density (MVD) was highest in the control group (56.4 ± 15.2), significantly lower in the RGZ group (44.6 ± 11.2) (P < 0.05), and lowest in the RGZ + ATRA group (21.5 ± 8.6, P < 0.01).

CONCLUSIONSThe growth of myeloma cells can also be inhibited by RGZ and ATRA in nude mice in vivo. In addition to differentiation and apoptosis induction, RGZ can inhibit the formation of myeloma xenograft probably also through the downregulation of VEGF expression and subsequent angiogenesis.

Animals ; Antigens, CD34 ; metabolism ; Antineoplastic Agents ; pharmacology ; Apoptosis ; drug effects ; Cell Line, Tumor ; Cell Proliferation ; drug effects ; Dose-Response Relationship, Drug ; Drug Synergism ; Female ; Humans ; Mice ; Mice, Inbred BALB C ; Mice, Nude ; Microvessels ; pathology ; Multiple Myeloma ; metabolism ; pathology ; Neoplasm Transplantation ; Neovascularization, Pathologic ; RNA, Messenger ; metabolism ; Thiazolidinediones ; administration & dosage ; pharmacology ; Tretinoin ; pharmacology ; Tumor Burden ; drug effects ; Vascular Endothelial Growth Factor A ; genetics ; metabolism ; Xenograft Model Antitumor Assays