The aim of this study was to investigate the effect of sorafenib combined with daunorubicin on leukemic k562 cell line. The inhibitory effect of sorafenib alone and its combination with daunorubicin on K562 cell proliferation was detected by MTT method; the synergistic effect was measured by CDI (coefficient of drug interaction); the apoptosis of K562 cells was observed by flow cytometry with Hoechst 33258 staining. The results showed that the sorafenib alone or its combination with daunorubicin could significantly inhibit K562 cell proliferation and the combination of both drugs displayed synergistic effect on K562 cells, meanwhile the apoptotic cells increased. It is concluded that the combination of sorafenib and daunorubicin has a obviously synergistic inhibitory effect on leukemic cell line K562.
Apoptosis ; drug effects ; Benzenesulfonates ; pharmacology ; Daunorubicin ; pharmacology ; Drug Synergism ; Humans ; K562 Cells ; Niacinamide ; analogs & derivatives ; Phenylurea Compounds ; Pyridines ; pharmacology

Portal hypertension, as one of the major complications of liver cirrhosis, is a common clinical syndrome characterized by an increased portal pressure and the formation of portal-systemic collaterals. Currently no ideal therapeutic agent has been available for portal hypertension. Sorafenib is an oral tyrosine kinase inhibitor that has been shown to significantly improve blood flow dynamics, inhibit angiogenesis, reduce liver fibrosis and decrease portal pressure in the treatment of portal hypertension. The authors review the progress in the research of sorafenib in the treatment of portal hypertension and the mechanisms of its actions.
Animals ; Humans ; Hypertension, Portal ; drug therapy ; Niacinamide ; analogs & derivatives ; pharmacology ; therapeutic use ; Phenylurea Compounds ; pharmacology ; therapeutic use

OBJECTIVETo investigate the interference effect of nicotinamide on UVA-induced cell proliferation in human skin melanocyte.

METHODSTo apply the optimum UVA dose expected to cause cell proliferation: 0.2 cm2, nicotinamide was added after the 0.2 cm2 UVA exposure immediately or 48 h later, then the rate of cell proliferation, calcium concentration and the activities of Na+-K+, Ca2+-ATP enzymes of melanocytes were measured respectively.

RESULTSAfter treatment with 1.000 mg/ml nicotinamide following UVA exposure, the rate of cell proliferation was decreased significantly 24 hours later. Treatment with 0.125 mg/ml nicotinamide 48 hours after UVA exposure also significantly inhibited the cell proliferation; 1.25 mg/ml nicotinamide increased calcium concentration in cells; 0.250 mg/ml nicotinamide increased the activities of Na+-K+, Ca2+-ATP enzymes in melanocytes (P < 0.05).

CONCLUSIONNicotinamide has more obvious effect on inhibiting melanocyte's proliferation if added immediately following UVA exposure. Our discovery indicated that nicotinamide may affect the melanocyte through modulating the calcium concentration. It is possible to consider nicotinamide as an efficient and safe sun screen to provide a certain level of protection for UVA exposed skin.

Cell Proliferation ; drug effects ; radiation effects ; Cells, Cultured ; Humans ; Melanocytes ; cytology ; Niacinamide ; pharmacology ; Skin ; cytology ; Ultraviolet Rays

OBJECTIVETo investigate the interference effect of nicotinamide on UVA-induced melanin genesis and melanin transport in human skin melanocyte.

METHODSThe optimum UVA dose expected to cause cell proliferation: 0.2 J/cm(2), nicotinamide was added immediately after the 0.2 J/cm(2) UVA exposure and the melanin content, cell cycles, cell apoptosis and mRNA express level were measured respectively.

RESULTSMelanin content in melanocytes was increased significantly after exposed to 0.2 J/cm(2) UVA. Melanin content in melanocytes was decreased after treatment with 10.0 mmol/ml nicotinamide following UVA exposure, but the cell cycles and the cell apoptosis rate were not significantly altered. mRNA express levels of TYR, TRP-1 were modulated by nicotinamide.

CONCLUSIONNicotinamide has more effect on decreasing melanin genesis after UVA exposure, nicotinamide also plays a role in modulating the mRNA express of TYR, TRP-1 gene. It is possible to consider nicotinamide as an efficient and safe sun screen to provide a certain level of protection for UVA exposed skin.

Cells, Cultured ; Humans ; Melanins ; biosynthesis ; Melanocytes ; drug effects ; metabolism ; radiation effects ; Niacinamide ; pharmacology ; Ultraviolet Rays ; adverse effects

OBJECTIVETo seek an appropriate culture condition in which porcine hepatocytes can continuously proliferate and express their normal differentiation phenotypes for a longer period of time.

METHODSDifferent types and dosages of reagents, transferrin, epidermal growth factor and nicotinamide were used to culture porcine hepatocytes in serum-free Dulbecco's modified Eagle's medium (DMEM). And the proliferative effects and functions of the cells were detected at different culture times.

RESULTSTransferrin at 5 ng/ml, nicotinamide at 10 mmol/L and epidermal growth factor at 10 ng/ml had better effects on the viability of hepatocytes than DMEM, DMEM + 10% fetal cattle serum FCS and other dosages of these reagents (P < 0.05). OD values of MTS were still high in culture at day 7 and day 10, while nearly 30% - 35% cells went into the S phase. Good hepatocyte functions were found in these groups, and the secretion of albumin was positively correlated with OD value of MTS. The levels of aspartate transaminase and ammonia in these media were lower than those in DMEM and DMEM + FCS.

CONCLUSIONTransferrin at 5 ng/ml, epidermal growth factor at 10 ng/ml and nicotinamide at 10 mmol/L are beneficial to the viability and proliferation of hepatocytes.

Animals ; Cell Division ; drug effects ; Cell Survival ; drug effects ; Cells, Cultured ; Epidermal Growth Factor ; pharmacology ; Hepatocytes ; cytology ; drug effects ; Niacinamide ; pharmacology ; Swine ; Transferrin ; pharmacology

To investigate the effects of sorafenib and octreotide combination treatment on cellular proliferation and explore the underlying molecular mechanisms by using an in vitro cell culture system with the human hepatoma cell line, HepG2. HepG2 cells were treated with different concentrations of sorafenib and octreotide alone or in combination. Untreated HepG2 cells were used as controls. Treatment-induced cytotoxicity was determined with the cell counting kit-8 by Sigma-Aldrich, and rate of apoptosis was detected by flow cytometry. Fluorescent microscopy was used to observe rates of cell growth under the various treatments. Treatment-induced changes in protein expressions were detected by enzyme-linked immunosorbent assay (for vascular endothelial growth factor (VEGF)) and Western blotting (for the Mcl-1 apoptosis mediator and the ERK1/2 and PERK1/2 kinases). Sorafenib and octreotide, used alone or in combination, inhibited proliferation and induced apoptosis in HepG2 cells. Combination treatment was more effective than either mono-treatment (F = 200.398, P less than 0.05). Fluorescent microscopy showed that combination treatment stimulated phosphatidylserine, the marker of early apoptosis, better than either mono-treatment. VEGF expression in cultures exposed to combination treatment was also significantly lower than in mono-treatment or untreated control cultures (F = 1019.725, P less than 0.05). Western blotting showed that octreotide mono-treatment had no effect on Mcl-1 expression (vs. control group; P more than 0.05) and that combination treatment significantly lowered Mcl-1 expression (vs. mono-treatment and control groups; P less than 0.05). None of the treatments affected ERK1/2 expression (all, P more than 0.05), while all treatments significantly lowered PERK1/2 expression (vs. control group; F = 2.401, P less than 0.05) and the combination treatment lowered PERK1/2 significantly more than either mono-treatment (P less than 0.05). Sorafenib and octreotide can inhibit proliferation and induce apoptosis in the human hepatoma cell line, HepG2. Combination treatment is significantly more efficacious (P less than 0.05) and produced synergistic effects. The mechanism underlying this phenomenon may depend on synergistic inhibition of VEGF, the anti-apoptotic protein Mcl-1, and the proliferation-inducing PERK1/2.
Apoptosis ; drug effects ; Benzenesulfonates ; pharmacology ; Cell Proliferation ; drug effects ; Hep G2 Cells ; drug effects ; Humans ; Niacinamide ; analogs & derivatives ; Octreotide ; pharmacology ; Phenylurea Compounds ; Pyridines ; pharmacology

OBJECTIVETo investigate the anti-cancer efficacy and mechanism of sorafenib and 5-fluorouracil (5-FU) therapy in vitro using the HCC cell line MHCCLM3.

METHODSThe effects of sorafenib and 5-FU, alone or in combination, on the proliferation of MHCCLM3 cells were evaluated by cell viability assays. Combined-effects analyses were conducted according to the median-effect principle established by Chou and Talalay. Effects on cell cycle distributions were tested by flow cytometry and expression of proteins related to the RAF/MEK/ERK and STAT3 signaling pathways and cyclinD1 were tested by western blotting.

RESULTSSorafenib and 5-FU alone or in combination displayed significant efficacy in inhibiting proliferation of the MHCCLM3 cells, with the following inhibition rates: sorafenib: 46.16% +/- 2.52%, 5-FU: 28.67% +/- 6.16%, and sorafenib + 5-FU: 22.59% +/- 6.89%. The sorafenib + 5-FU combination did not provide better results than treatment with either drug alone. The combination index values of the sorafenib and 5-FU treatments were mainly greater than 1, indicating that the two agents induced antagonistic, instead of synergistic, effects on the MHCCLM3 cells. In addition, the MHCCLM3 cells were less sensitive to 5-FU when administrated in combination with sorafenib, as evidenced by the half inhibitory concentration (IC50) significantly increasing from (102.86 +/- 27.84) mg/L to (178.61 +/- 20.73) mg/L (P = 0.003). Sorafenib alone induced G1 phase arrest (increasing from 44.73% +/- 1.63% to 65.80% +/- 0.56%; P less than 0.001) and significantly decreased the proportion of cells in S phase (decreasing from 46.63% +/- 0.65% to 22.83% +/- 1.75%; P less than 0.01), as well as down-regulated cyclinD1 expression (0.57 +/- 0.03-fold change vs. untreated control group; P less than 0.01). 5-FU alone up-regulated cyclinD1 expression (1.45 +/- 0.12-fold change vs. untreated control group; P less than 0.01). Moreover, sorafenib alone significantly inhibited the RAF/MEK/ERK and STAT3 pathways, with the fold-changes of p-C-RAF, p-ERK1/2 and p-STAT3 being 0.56 +/- 0.05, 0.54 +/- 0.02 and 0.36 +/- 0.02, respectively (all P less than 0.01); 5-FU alone produced no significant effects on these pathways.

CONCLUSIONAdministered alone, both sorafenib and 5-FU exert anti-tumoral activity on in vitro cultured HCC cells. The sorafenib + 5-FU combination treatment produces antagonistic, rather than synergistic, effects. Sorafenib-inhibited RAF/MEK/ERK and STAT3 signaling and cyclinD1 expression may have induced the observed G1phase arrest and S phase reduction, thereby reducing the cells' sensitivity to 5-FU.

Cell Line, Tumor ; Cell Proliferation ; drug effects ; Cyclin D1 ; metabolism ; Drug Antagonism ; Fluorouracil ; pharmacology ; Humans ; Niacinamide ; analogs & derivatives ; pharmacology ; Phenylurea Compounds ; pharmacology ; STAT3 Transcription Factor ; metabolism ; Signal Transduction

The present study was aimed to investigate the effect of pretreatment with Danshensu (DSS) on rat aortic endothelial cells (RAECs) senescence and the underlying mechanisms. Cultured RAECs at fourth and twelfth passages were taken as young and old groups, respectively. DSS and DSS+nicotinamide (DSS+N) groups were incubated with DSS and DSS in combination with nicotinamide, an inhibitor of silent information regulator 1 (SIRT1), from the fourth to twelfth passage, respectively. The cell status of senescence was determined by the senescence-associated β-galactosidase (SA β-gal) staining, and 4,6-diamino-2-phenyl indole (DAPI) fluorescent dye was used to detect senescence associated heterochromatin foci (SAHF) formation; Thiobarbituric acid (TBA) and colorimetric methods were used to evaluate malondialdehyde (MDA) and H₂O₂contents; Western blot was employed to analysis the expressions of xanthine oxidase (XOD), SIRT1 and superoxide dismutase 2 (SOD₂) in the RAECs. The results showed that, in comparison with young group, the old group exhibited higher SA β-gal positive and SAHF formation rates, as well as higher MDA and H₂O₂levels (P < 0.05 or P < 0.01), whereas DSS pretreatment reduced SA β-gal positive and SAHF formation rates, decreased MDA and H2O2 contents (P < 0.05 or P < 0.01). The protection of DSS was reversed by nicotinamide. Compared with the young group, the old group showed higher expression levels of XOD, but lower SIRT1 and SOD₂expression levels (P < 0.05 or P < 0.01). With the pretreatment of DSS, the expression of XOD was declined, and the expression levels of SIRT1 and SOD₂were elevated, while nicotinamide reversed the effects of DSS. These results suggest that DSS delays senescence of RAECs via up-regulation of SIRT1.
Animals ; Aorta ; cytology ; Cells, Cultured ; Cellular Senescence ; drug effects ; Endothelial Cells ; cytology ; Hydrogen Peroxide ; metabolism ; Lactates ; pharmacology ; Niacinamide ; pharmacology ; Rats ; Sirtuin 1 ; metabolism ; Superoxide Dismutase ; metabolism ; Up-Regulation

Nicotinamide at millimolar concentrations affects cell survival in various conditions, and is being utilized therapeutically in many human diseases. However, the effect of an acute treatment of nicotinamide at such high dose on gene expression and cellular metabolism has rarely been determined previously. In this study, we found that levels of O-N-acetylglucosamin(O- GlcNAc)ylated proteins including Sp1 acutely decreased upon treatment of 10 mM nicotinamide. Concomitantly, Sp1 protein level decreased rapidly through accelerated proteasome-mediated proteolysis. Cotreatment of glucosamine or 2-deoxyglucose, which inhibits protein deGlcNAcylation, effectively blocked the decrease induced by nicotinamide. Interestingly, the decline in the levels of Sp1 and protein O- GlcNAcylation was only transient lasting for two days post treatment, and this pattern matched closely the rapid fluctuation of the cellular [NAD(+)]. Our results suggest a possible link between cellular nicotinamide metabolism and protein O-GlcNAcylation, and an existence of cellular [NAD(+)] homeostasis.
Acetylglucosamine/*metabolism ; Blotting, Western ; Dose-Response Relationship, Drug ; Down-Regulation/*drug effects ; Humans ; Hydrolysis ; Niacinamide/*pharmacology ; Reverse Transcriptase Polymerase Chain Reaction ; Sp1 Transcription Factor/metabolism

OBJECTIVETo investigate the effect and mechanism of high dose Vitamin B3 on granulopoiesis in normal rat.

METHODSTwenty one healthy SD rats were randomly divided into three groups: the Vitamin B3 group (Vit B3 500 mg·kg⁻¹·d⁻¹, × 7 d), the rhG-CSF group (rhG-CSF 25 μg·kg⁻¹·d⁻¹, × 7 d) and the normal saline group (2 ml/d, × 7 d). The peripheral blood cell counts were analyzed by automatic blood cell counter before (day 0) treatment, the third day (day 3) and the seventh day (day 7) after administration of drugs, respectively. The concentration of serum nicotinamide adenine dinucleotide (NAD⁺) level was measured by enzymatic cycling assay before and after drugs treatment. The expressions of G-CSF, G-CSFR, SIRT1, C/EBPα, C/EBPβ, C/EBPε and NAMPT mRNA were detected by reverse transcription real-time fluorescent quantitative PCR.

RESULTSThe neutrophil counts increased significantly after 7 days of Vitamin B3 and rhG-CSF treatment compared with that of control group [(1.64 ± 0.19) × 10⁹/L, (1.88 ± 0.37)× 10⁹/L vs (0.86 ± 0.18) × 10⁹/L, P<0.01]; the level of serum NAD⁺ increased significantly [(0.96 ± 0.08) nmol/L, (0.65 ± 0.12) nmol/L vs (0.36 ± 0.15) nmol/L, P<0.01]; the expression of G-CSF, G-CSFR, SIRT1, C/EBPα, C/EBPε and NAMPT mRNA in bone marrow mononuclear cells were increased significantly compared with that of control group (P<0.01).

CONCLUSIONHigh dose of Vitamin B3 may play an important role in increasing absolute neutrophil count in healthy rat under steady state, and the mechanism may be dependent on NAMPT-NAD⁺-SIRT1 signaling pathways.

Animals ; Bone Marrow Cells ; Granulocyte Colony-Stimulating Factor ; Leukocyte Count ; Neutrophils ; drug effects ; Niacinamide ; pharmacology ; Rats ; Rats, Sprague-Dawley ; Recombinant Proteins