OBJECTIVE: To study the effects of oligodeoxynucleotides complementary Stat3 on apoptosis in laryngeal carcinoma Hep-2 cell. METHOD: Oligodeoxynucleotides complementary Stat3 was designed, which was transferred into laryngeal carcinoma Hep-2 cell by lipofection. Expression of Stat3 and p-Stat3 were detected by Western blot and PCR. MTT was used to observe the growth-inhibiting ratio. DNA ladder, AO/EB and FCM were used to observe the apoptosis of laryngeal carcinoma cell Hep-2 in vitro. RESULT: Western blot and PCR results demonstrated that oligodeoxynucleotides complementary Stat3 could significantly inhibit the expression of Stat3 and p-Stat3 in Hep-2 cell. MTT results showed that it could significantly suppress the growth of Hep-2 cell. The DNA ladder, AO/EB and FCM results showed it could inhibit the expression of Stat3 and induce the apoptosis of Hep-2 cell in a concentration-dependent manner. CONCLUSION Oligodeoxynucleotides complementary Stat3 could induce the apoptosis and suppress cell proliferation in laryngeal carcinoma Hep-2 cell.
Apoptosis ; drug effects ; Cell Line, Tumor ; Cell Proliferation ; drug effects ; Humans ; Oligodeoxyribonucleotides ; genetics ; pharmacology ; STAT3 Transcription Factor ; genetics ; Transfection

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

OBJECTIVETo investigate the role of TGF-beta1 and STAT3 signaling in liver fibrosis using a rat model system and to determine the therapeutic mechanism of AG490 in relation to this signaling pathway.

METHODSRats were randomly divided into a control group and DENA-induced liver fibrosis model group, and then subdivided into AG490 treatment groups. During fibrosis development, liver tissue samples were collected at different time points (0, 4 and 8 weeks) and evaluated according to the Scheuer scoring system. Expression of STAT3, TGFbeta1, alpha-SMA, E-cadherin, MMP2 and TIMP1 was measured by PCR (mRNA) and immunohistochemistry and western blotting (protein).

RESULTSIncreasing degrees of inflammation and fibrosis were observed in liver tissues of DENA-treated rats throughout model establishment. The mRNA expression of TGFbeta1 and STAT3 was significantly increased in DENA-induced rats with advanced fibrosis (AF) compared to those with early fibrosis (EF) (P = 0.034 and P = 0.012 respectively). The protein expression of TGF-beta1, phospho-Smad2, alpha-SMA, E-cadherin, STAT3 and phospho-STAT3 was significantly increased in DENA-induced rats with AF compared to the unmodeled control group (P = 0.048, P = 0.003, P = 0.002, P = 0.028, P = 0.009 and P = 0.039). The protein expression of E-cadherin was lower in the DENA-induced rats with AF than in those with EF (P = 0.026). STAT3 and TGF-beta1 co-expression was detected in AF tissues. DENA-induced AG490-treated rats with AF showed substantially lower protein expression of STAT3, TGF-beta1, MMP2 and TIMP1 compared to DENA-induced untreated rats with AF (P = 0.006, P = 0.018, P = 0.010 and P = 0.005); in addition, the degrees of fibrosis and inflammation were also greatly reduced in the DENA-induced AG490-treated rats with AF compared to DENA-induced untreated rats with AF (P = 0.042 and P = 0.021). Conclusions STAT3 signal transduction may regulate the TGF-beta1 pathway and affect liver fibrosis, especially in the advanced phase. AG490 can inhibit TGFbeta1-STAT3 signaling, resulting in reversal of liver fibrosis.

Animals ; Disease Models, Animal ; Liver Cirrhosis ; chemically induced ; metabolism ; Rats ; Rats, Sprague-Dawley ; STAT3 Transcription Factor ; metabolism ; Signal Transduction ; Transforming Growth Factor beta1 ; metabolism ; Tyrphostins ; pharmacology

BACKGROUNDAdvances in the understanding of cardiovascular pathogenesis have highlighted that inflammation plays a central role in atherosclerotic coronary heart disease. Therefore, exploring pharmacologically based anti-inflammatory treatments to be used in cardiovascular therapeutics is worthwhile to promote the discovery of novel ways of treating cardiovascular disorders.

METHODSThe myocardial cell line H9c2(2-1) was exposed to lipopolysaccharide (LPS) in culture and resulted in a cellular pro-inflammation status. miR-21 microRNA levels were detected using quantitative real-time polymerase chain reaction (Q-RT-PCR). The influence of lovastatin on miR-21 under normal and pro-inflammatory conditions was tested after being added to the cell culture mixture for 24 hours. Conditional gene function of two predicted cardiovascular system relevant downstream targets of miR-21, protein phosphatase 1 regulatory subunit 3A (PPP1R3A) and signal transducer and activator of transcription 3 (STAT3), were analyzed with immunoblotting.

RESULTSForty-eight hours of LPS treatment significantly increased the miR-21 to 170.71%± 34.32% of control levels (P = 0.002). Co-treatment with lovastatin for 24 hours before harvesting attenuated the up-regulation of miR-21 (P = 0.013). Twenty-four hours of lovastatin exposure up-regulated PPP1R3A to 143.85%± 21.89% of control levels in cardiomyocytes (P = 0.023). Lovastatin up-regulated the phosphorylation level of STAT3 compared to the background LPS pretreatment (P = 0.0077), this effect was significantly (P = 0.018) blunted when miR-21 was functionally inhibited.

CONCLUSIONSmiR-21 plays a major role in the regulation of the cellular anti-inflammation effects of lovastatin.

Blotting, Western ; Cell Line ; Humans ; Lipopolysaccharides ; pharmacology ; Lovastatin ; pharmacology ; MicroRNAs ; genetics ; Myocardium ; metabolism ; Myocytes, Cardiac ; drug effects ; metabolism ; Phosphoprotein Phosphatases ; metabolism ; Phosphorylation ; STAT3 Transcription Factor ; metabolism

OBJECTIVETo investigate the effects of cycle-dependent kinase (CDK) inhibitor SNS-032 on apoptosis in human acute myeloid leukemia (AML) HL-60 cells and its molecular mechanisms.

METHODSCultured AML HL-60 cells were treated with various concentrations of SNS-032. Cell apoptosis was determined with flow cytometry;cell viability was measured by MTT assay; the profiles of microRNA expression of HL-60 cells were analyzed by microRNA microarray;the protein expressions of JAK2/STAT3 pathway were detected by Western blotting.

RESULTSApoptosis of AML HL-60 cells was induced by SNS-032; the rate of apoptosis was (5.9±1.7)%, (12.1±3.1)% and (59.4±3.6)% when HL-60 cells were treated with 0,100 and 200 nmol/L SNS-032. MicroRNA microarray analysis revealed that the levels of miR-30a, miR-183, miR-20b, miR-26b, miR-20a, miR-589, miR-107, miR-181a, miR-106a, miR-17 and miR-378c were down-regulated by SNS-032,whereas the levels of miR-320a and miR-H7* were up-regulated. Western blotting showed that SNS-032 strongly inhibited phosphorylation of STAT3 and protein expression of JAK2,C-MYC and MCL-1.

CONCLUSIONCDK inhibitor SNS-032 can induce apoptosis of AML HL-60 cells, which is associated with the inhibition of MCL-1,C-MYC and JAK2/STAT3, and down-regulation of miR-17-92 family.

Apoptosis ; Cell Survival ; Down-Regulation ; Flow Cytometry ; HL-60 Cells ; Humans ; Janus Kinase 2 ; metabolism ; MicroRNAs ; metabolism ; Oxazoles ; pharmacology ; Phosphorylation ; STAT3 Transcription Factor ; metabolism ; Signal Transduction ; Thiazoles ; pharmacology

OBJECTIVETo study the effect of matrine and oxymatrine on proliferation and the expression of Stat3, Stat5 mRNA in SMMC-7721 cell line.

METHODTreated with matrine and oxymatrine, the inhibitory effect on SMMC-7721 cell proliferation was detected by MTT, double fluorescence labeling was applied to measure the apotosis ratios of SMMC-7721cells, the expression of Stat3 and Stat5 mRNA in SMMC-7721 cell line were assessed with RT-PCR.

RESULTMatrine and oxymatrine could inhibit the proliferation and induce the apoptosis of SMMC-7721 cells and it was time and dose dependent, the expression of Stat3 and Stat5 mRNA in SMMC-7721 cell with matrine and oxymatrine were significantly lower than those in control group (P<0.05 or P<0.01). Compared with the same dose of matrine and oxymatrine, matrine showed stronger effect on cell proliferation, apoptosis, and Stat3 and Stat5 mRNA (P<0.05 or P<0.01).

CONCLUSIONMatrine and oxymatrine inhibited the proliferation and induced the of SMMC-7721 cells significantly, the mechanism of which might be related to the down-regulation of stat3 and stat5 mRNA and inhibition of the signaling transduction pathway.

Alkaloids ; pharmacology ; Apoptosis ; drug effects ; Cell Line, Tumor ; Cell Proliferation ; drug effects ; Drugs, Chinese Herbal ; pharmacology ; Gene Expression Regulation ; drug effects ; Humans ; Quinolizines ; pharmacology ; Reverse Transcriptase Polymerase Chain Reaction ; STAT3 Transcription Factor ; genetics ; STAT5 Transcription Factor ; genetics

OBJECTIVETo investigate the effect of cardiotrophin-1 (CT-1) on the GATA4 expression and related signaling pathways (JAK-STAT3, ERK1/2 and PI3-K) in rat cardiomyocytes.

METHODSUsing semi-quantitative RT-PCR and EMSA, we measured the dose and time dependent effects of CT-1 on GATA4 mRNA and binding activity in cultured rat cardiomyocytes. Parthenolide (a STAT inhibitor), U-0126 (an ERK inhibitor) and LY-294002 (a PI3-K inhibitor) alone or in combination were added to the culture medium to assess the role of above signaling pathways in CT-1 mediated effects.

RESULTSGATA4 mRNA expression significantly increased at 3 h post 0.1 nmol/L CT-1 exposure, peaked at 6 h and remained high till 24 h post exposure. The GATA4 binding activity began to increase at 10 min and peaked at 60 min and returned to baseline level 180 min. Six hours post CT-1 (0.01 nmol/L, 0.1 nmol/L, 1 nmol/L) exposure, the GATA4 mRNA expression increased in a dose-dependent manner. The GATA4 binding activity peaked with 0.1 nmol/L CT-1 and higher dose did not further increase the binding activity. U-0126 increased the GATA4 mRNA expression and enhanced the GATA4 binding activity and these effects could be partially attenuated with addition of Parthenolide. Parthenolide also prevented the increase of GATA4 mRNA and binding activity induced by CT-1. LY-294002 had no effects GATA4 mRNA and binding activity.

CONCLUSIONCT-1 increases the GATA4 mRNA expression and binding activity in rat cardiomyocytes via STAT3/ERK1/2 pathways and these effects are independent of PI3-K pathway.

Animals ; Cell Line ; Cytokines ; pharmacology ; GATA4 Transcription Factor ; biosynthesis ; genetics ; Myocytes, Cardiac ; metabolism ; RNA, Messenger ; biosynthesis ; Rats ; Rats, Sprague-Dawley ; Reverse Transcriptase Polymerase Chain Reaction ; STAT3 Transcription Factor ; pharmacology ; Signal Transduction

We investigated the effect of phenylephrine (PE)- and isoproterenol (ISO)-induced cardiac hypertrophy on subcellular localization and expression of caveolin-3 and STAT3 in H9c2 cardiomyoblast cells. Caveolin-3 localization to plasma membrane was attenuated and localization of caveolin-3 to caveolae in the plasma membrane was 24.3% reduced by the catecholamine-induced hypertrophy. STAT3 and phospho-STAT3 were up-regulated but verapamil and cyclosporin A synergistically decreased the STAT3 and phospho-STAT3 levels in PE- and ISO-induced hypertrophic cells. Both expression and activation of STAT3 were increased in the nucleus by the hypertrophy. Immunofluorescence analysis revealed that the catecholamine-induced hypertrophy promoted nuclear localization of pY705-STAT3. Of interest, phosphorylation of pS727-STAT3 in mitochondria was significantly reduced by catecholamine-induced hypertrophy. In addition, mitochondrial complexes II and III were greatly down-regulated in the hypertrophic cells. Our data suggest that the alterations in nuclear and mitochondrial activation of STAT3 and caveolae localization of caveolin-3 are related to the development of the catecholamine-induced cardiac hypertrophy.
Animals ; Catecholamines/*pharmacology ; Caveolae/*metabolism ; Caveolin 3/*metabolism ; Cell Line ; Hypertrophy/metabolism ; Mitochondria/*metabolism ; Myocardium/cytology/*pathology ; Myocytes, Cardiac/cytology/*drug effects/metabolism ; Rats ; STAT3 Transcription Factor/*metabolism

OBJECTIVE: To explore the mechanisms underlying the proliferative inhibition of Chinese herbal medicine Kang-Ai injection (KAI) in gastric cancer cells. METHODS: Gastric cancer cell lines MGC803 and BGC823 were treated by 0, 0.3%, 1%, 3% and 10% KAI for 24, 48 and 72 h, respectively. The cell proliferation was evaluated by 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2-H-tetrazolium bromide (MTT) assay. The apoptosis and cell cycle were evaluated by flow cytometry. Interleukin (IL)-6 mRNA and protein expression levels were detected by quantitative real-time polymerase chain reaction (qRT-PCR) and enzyme-linked immune sorbent assay (ELISA), respectively. The protein expression levels of cyclin A, cyclin E, cyclin B1, cyclin D1, p21, retinoblastoma (RB), protein kinase B (AKT), extracellular regulated protein kinases (ERK), signal transducer and activator of transcription (STAT) 1 and STAT3 were detected by Western blot. RESULTS: KAI inhibited the proliferation of MGC803 and BGC823 gastric cancer cells in dose- and time-dependent manner. After treated with KAI for 48 h, the proportion of G1 phase was increased, expression level of cyclin D1 and phosphorylation-RB were down-regulated, whereas the expression of p21 was up-regulated (all P<0.01). Furthermore, 48-h treatment with KAI decreased the phosphorylation level of STAT3, inhibited the mRNA and protein expressions of IL-6 (all P<0.01). IL-6 at dose of 10 ng/mL significantly attenuated the proliferative effect of both 3% and 10% KAI, and recovered KAI-inhibited STAT3 phosphorylation and cyclin D1 expression level (all P<0.01). CONCLUSION KAI exerted an anti-proliferative function by inhibiting IL-6/STAT3 signaling pathway followed by the induction of G₁ phase arrest in gastric cancer cells.
Apoptosis ; Cell Line, Tumor ; Cell Proliferation ; Cyclin D1/pharmacology* ; Humans ; Interleukin-6/metabolism* ; RNA, Messenger/metabolism* ; STAT3 Transcription Factor/metabolism* ; Stomach Neoplasms/genetics*

Objective: To investigate the role and mechanism of tumor-derived mesenchymal stem cells in regulating the M2 polarization of macrophages within gastric cancer microenvironment. Methods: Gastric cancer tissues and the adjacent non-cancerous tissues were collected from patients underwent gastric cancer resection in the First People's Hospital of Lianyungang during 2018. In our study, THP-1-differentiated macrophages were co-cultured with gastric cancer-derived mesenchymal stem cells (GC-MSCs). Then, the M2 subtype-related gene, the markers expressed on cell surface and the cytokine profile were analyzed by real-time quantitative reverse transcription polymerase chain reaction (qRT-PCR), flow cytometry and Luminex liquid chip, respectively. The key cytokines mediating the inducing effect of GC-MSCs on macrophage polarization into the M2 subtype were detected and screened by Luminex liquid chip, which were further confirmed by the neutralizing antibody test. The expressions of macrophage proteins involved in M2 polarization-related signaling pathways under the different co-culture conditions of GC-MSCs were detected by western blot. Results: In Mac+ GC-MSC-culture medium (CM) group, the expression levels of Ym-1 and Fizz-1 (1.53±0.32 and 13.22±1.05, respectively), which are markers for M2 subtype, were both significantly higher than those of Mac group (1.00±0.05 and 1.21±0.38, respectively, P<0.05). The level of iNOS in Mac+ GC-MSC-CM group (0.60±0.41) was significantly lower than that of Mac group (1.06±0.38, P=0.023). In Mac+ GC-MSC-Transwell (TW) group, the expression levels of Ym-1 and Fizz-1 (1.47±0.09 and 13.16±2.77, respectively) were both significantly higher than those of Mac group (1.00±0.05 and 1.21±0.38, respectively, P<0.05). The level of iNOS in Mac+ GC-MSC-CM group (0.56±0.03) was significantly lower than that of Mac group (1.06±0.38, P=0.026). The ratios of CD163(+) /CD204(+) cells in Mac+ GC-MSC-CM and Mac+ GC-MSC-TW groups (3.80% and 4.40%, respectively) were both remarkably higher than that of Mac group (0.60%, P<0.05). The expression levels of IL-10, IL-6, MCP-1 and VEGF in Mac+ GC-MSC-CM group were (592.60±87.52), (1 346.80±64.70), (11 256.00±29.03) and (1 463.90±66.67) pg/ml, respectively, which were significantly higher than those of Mac group [(41.03±2.59), (17.35±1.79), (5 213.30±523.71) and (267.12±12.06) pg/ml, respectively, P<0.05]. The levels of TNF-α, IP-10, RANTES and MIP-1α were (95.57±9.34), (410.48±40.68), (6 967.30±1.29) and (1 538.70±283.04) pg/ml, which were significantly lower than those of Mac group [(138.01±24.31, (1 298.60±310.50), (14 631.00±4.21) and (6 633.20±1.47) pg/ml, respectively, P<0.05]. The levels of IL-6 and IL-8 in GC-MSCs [(11 185.02±2.82) and (12 718.03±370.17) pg/ml, respectively] were both strikingly higher than those of MSCs from adjacent non-cancerous gastric cancer tissues [(270.71±59.38) and (106.04±32.84) pg/ml, repectively, P<0.05]. The ratios of CD86(+) cells in Mac+ IL-6-blocked-GC-MSC-CM and Mac+ IL-8-blocked-GC-MSC-CM groups (28.80% and 31.40%, respectively) were both higher than that of Mac+ GC-MSC-CM group (24.70%). Compared to Mac+ GC-MSC-CM group (13.70%), the ratios of CD204(+) cells in Mac+ IL-6-blocked-GC-MSC-CM and Mac+ IL-8-blocked-GC-MSC-CM groups (9.90% and 8.70%, separately) were reduced. The expression levels of p-JAK2 and p-STAT3, which are proteins of macrophage M2 polarization-related signaling pathway, in Mac+ GC-MSC-CM group (0.86±0.01 and 1.08±0.01, respectively) were significantly higher than those of Mac group (0.50±0.01 and 0.82±0.01, respectively, P<0.05). The expression levels of p-JAK2 in Mac+ IL-6-blocked-GC-MSC-CM group (0.47±0.02) were significantly lower those that of Mac+ GC-MSC-CM group (0.86±0.01, P<0.05). The expression levels of p-JAK2 and p-STAT3 in Mac+ IL-8-blocked-GC-MSC-CM group (0.50±0.01 and 0.85±0.01, respectively) were both significantly lower than those of Mac+ GC-MSC-CM group (0.86±0.01 and 1.08±0.01, P<0.05). The expression levels of p-JAK2 and p-STAT3 in Mac+ IL-6/IL-8-blocked-GC-MSC-CM group (0.37±0.01 and 0.65±0.01, respectively) were both significantly lower than those of Mac+ GC-MSC-CM group (0.86±0.01 and 1.08±0.01, P<0.05). Conclusion: GC-MSCs promote the activation of JAK2/STAT3 signaling pathway in macrophages via high secretions of IL-6 and IL-8, which subsequently induce the macrophage polarization into a pro-tumor M2 subtype within gastric cancer microenvironment.
Humans ; Interleukin-6/genetics* ; Interleukin-8/pharmacology* ; Janus Kinase 2/metabolism* ; Macrophages/metabolism* ; Mesenchymal Stem Cells ; STAT3 Transcription Factor/metabolism* ; Signal Transduction ; Stomach Neoplasms/pathology* ; Tumor Microenvironment