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Objective To investigate the effect of recombinant Schistosoma japonicum egg ribonuclease SjCP1412 (rSjCP1412) on proliferation, cell cycle, apoptosis and activation of human hepatic stellate cells LX-2 in vitro, and explore the underlying mechanisms. Methods The rSjCP1412 protein was expressed in Escherichia coli BL21 by prokaryotic expression, and the highly purified soluble rSjCP1412 protein was prepared by Ni NTA affinity chromatography and urea gradient refolding dialysis. Yeast RNA was digested using 12.5, 25.0, 50.0 µg rSjCP1412 proteins at 37 °C for 2, 3, 4 h, and the enzymatic products were electrophoresed on 1.5% agarose gel to observe the RNAase activity of rSjCP1412 protein. The proliferation of LX-2 cells stimulated by different doses of rSjCP1412 protein for 48 hours was measured using CCK-8 assay, and the apoptosis of LX-2 cells stimulated by different doses of rSjCP1412 protein for 48 hours was detected using the Annexin V-FITC/PI double staining, while the percentage of LX-2 cells at G0/G1, S and G2/M phases of cell cycle following stimulation with different doses of rSjCP1412 protein for 48 h was detected by DAPI staining. The type I collagen, type III collagen and α-smooth muscle actin (α-SMA) mRNA expression was quantified using quantitative florescent real-time PCR (qPCR) assay and Western blotting at transcriptional and translational levels in LX-2 cells following stimulation with different doses of rSjCP1412 protein for 48 h, while soluble egg antigen (SEA) served a positive control and PBS without rSjCP1412 protein as a normal control in the above experiments. The expression of collagen I, α-SMA and Smad4 protein was determined using Western blotting in LX-2 cells following stimulation with rSjCP1412 protein, transforming growth factor-β1 (TGF-β1) alone or in combination, to examine the signaling for the effect of rSjCP1412 protein on LX-2 cells. Results The rSjCP1412 protein was successfully expressed and the highly purified soluble rSjCP1412 protein was prepared, which had a RNase activity. Compared with the normal group, the survival rates of LX-2 cells significantly decreased post-treatment with 12.5, 25.0, 50.0 µg/mL rSjCP1412 protein and SEA for 48 h (F = 22.417 and 20.448, both P values < 0.05). The apoptotic rates of LX-2 cells significantly increased post-treatment with 12.5, 25.0, 50.0 µg/mL rSjCP1412 protein for 48 h (F = 11.350, P < 0.05), and treatment with 12.5, 25.0, 50.0 µg/mL rSjCP1412 protein for 48 h resulted in arrest of LX-2 cells in G0/G1 phase (F = 20.710, P < 0.05). Treatment with 12.5, 25.0, 50.0 µg/mL rSjCP1412 protein for 48 h caused a significant reduction in relative expression levels of collagen I (F = 11.340, P < 0.05), collagen III (F = 456.600, P < 0.05) and α-SMA mRNA (F = 23.100, P < 0.05) in LX-2 cells, and both rSjCP1412 protein and SEA treatment caused a significant reduction in collagen I (F = 1 302.000, P < 0.05), α-SMA (F = 49.750, P < 0.05) and Smad4 protein expression (F = 52.420, P < 0.05) in LX-2 cells. In addition, rSjCP1412 protein treatment inhibited collagen I (F = 66.290, P < 0.05), α-SMA (F = 31.300, P < 0.05) and Smad4 protein expression (F = 27.010, P < 0.05) in LX-2 cells activated by TGF-β1. Conclusion rSjCP1412 protein may induce apoptosis of LX-2 cells and inhibit proliferation, cell cycle and activation of LX-2 cells through down-regulating Smad4 signaling molecules.
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Pancreatic ductal adenocarcinoma (PDAC) has poor prognosis due to limited therapeutic options. This study examines the roles of genome-wide association study identified PDAC-associated genes as therapeutic targets. We have identified HNF4G gene whose silencing most effectively repressed PDAC cell invasiveness. HNF4G overexpression is induced by the deficiency of transcriptional factor and tumor suppressor SMAD4. Increased HNF4G are correlated with SMAD4 deficiency in PDAC tumor samples and associated with metastasis and poor survival time in xenograft animal model and in patients with PDAC (log-rank P = 0.036; HR = 1.60, 95% CI = 1.03-2.47). We have found that Metformin suppresses HNF4G activity via AMPK-mediated phosphorylation-coupled ubiquitination degradation and inhibits in vitro invasion and in vivo metastasis of PDAC cells with SMAD4 deficiency. Furthermore, Metformin treatment significantly improve clinical outcomes and survival in patients with SMAD4-deficient PDAC (log-rank P = 0.022; HR = 0.31, 95% CI = 0.14-0.68) but not in patients with SMAD4-normal PDAC. Pathway analysis shows that HNF4G may act in PDAC through the cell-cell junction pathway. These results indicate that SMAD4 deficiency-induced overexpression of HNF4G plays a critical oncogenic role in PDAC progression and metastasis but may form a druggable target for Metformin treatment.
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Objective:To investigate the effect of pirfenidone (PFD) on the proliferation of human glomerular mesangial cells (HMC) stimulated by serum IgA1 in patients with IgA nephropathy (IgAN) and its possible mechanism.Methods:Serum IgA1 of IgAN patients was purified by Jacalin affinity chromatography combined with Sephacryl S-200 gel filtration, and then heated to aggregated form (aIgA1). CCK8 method was used to confirm the concentration and time of PFD. The cells were divided into blank control group, IgA1 (0.5 mg/ml) group and IgA1 (0.5 mg/ml)+PFD (2 mmol/L) group. The CCK8 method was used to detect proliferation of mesangial cells. The cell cycle was detected by flow cytometry, and the proliferation index of mesangial cells was calculated. The expression levels of transforming growth factor β1 (TGF-β1), Smad4, Smad7, fibronectin (FN) and collagen Ⅳ protein and mRNA were detected through Western blotting and real-time PCR.Results:Compared with blank control group, the proliferation of HMC was promoted significantly by aIgA1 ( P<0.05). After PFD treatment, the proliferation of HMC was significantly inhibited ( P<0.01). Compared with the blank control group, the number of G1 phase cells decreased, the number of S phase cells and cell proliferation index increased in IgA1 group (all P<0.05). Compared with IgA1 group, the number of cells in G1 phase increased significantly, the number of cells in S phase and G2/M phase decreased significantly, and the cell proliferation index decreased in IgA1+PFD group (all P<0.05). Western blotting and real-time PCR results showed that compared with the blank control group, the protein and mRNA expressions of collagen Ⅳ, FN and Smad4 in HMC stimulated by aIgA1 were significantly increased, while TGF-β1 protein expression was increased and Smad7 protein expression was decreased (all P<0.05). After PFD treatment, the protein and mRNA expression of collagen Ⅳ, FN and Smad4 in HMC was significantly decreased, while TGF-β1 protein expression was obviously decreased, and Smad7 protein was up-regulated (all P<0.05). There was no significant difference in the mRNA expression of TGF-β1 and Smad7 in each group before and after PFD treatment (all P>0.05). Conclusions:PFD can increase the arrest of HMC in G1 phase, inhibit the proliferation of HMC induced by aIgA1 of IgAN patients, and reduce the production of extracellular matrix. The mechanism may be related to up-regulation of Smad7 expression and down-regulation of TGF-β1/Smad4 pathway.
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Objective To investigate the mechanism via which artesunate regulates the invasion and metastasis of colon cancer cells and the expression of members of the TGF-β1/Smad4 signaling pathway. Methods The cell counting kit 8 (CCK8), nude mouse xenograft model, Transwell invasion assay, and flow cytometry were used to investigate the effect of artesunate on the invasion and metastasis of colon cancer cells. Western blotting and quantitative reverse transcription-polymerase chain reaction (qRT-PCR) were used to detect the expression of TGF-β1 and Smad4 proteins and mRNA, respectively. Results Artesunate inhibited the growth of transplanted tumor, cell proliferation, and invasion and promoted apoptosis. It inhibited TGF-β1 expression and promoted Smad4 expression. TGF-β1 inhibitors reversed the inhibitory effect of artesunate. Conclusion Artesunate can inhibit the growth of xenograft tumor in nude mice and its mode of action may be related to the TGF-β1/Smad4 signaling pathway.
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BACKGROUND: SMAD family member 4 (SMAD4) has gained attention as a promising prognostic factor of colorectal cancer (CRC) as well as a key molecule to understand the tumorigenesis and progression of CRC. METHODS: We retrospectively analyzed 1,281 CRC cases immunohistochemically for their expression status of SMAD4, and correlated this status with clinicopathologic and molecular features of CRCs. RESULTS: A loss of nuclear SMAD4 was significantly associated with frequent lymphovascular and perineural invasion, tumor budding, fewer tumor-infiltrating lymphocytes, higher pT and pN category, and frequent distant metastasis. In contrast, tumors overexpressing SMAD4 showed a significant association with sporadic microsatellite instability. After adjustment for TNM stage, tumor differentiation, adjuvant chemotherapy, and lymphovascular invasion, the loss of SMAD4 was found to be an independent prognostic factor for worse 5-year progression-free survival (hazard ratio [HR], 1.27; 95% confidence interval [CI], 1.01 to 1.60; p=.042) and 7-year cancer-specific survival (HR, 1.45; 95% CI, 1.06 to 1.99; p=.022). CONCLUSIONS: We confirmed the value of determining the loss of SMAD4 immunohistochemically as an independent prognostic factor for CRC in general. In addition, we identified some histologic and molecular features that might be clues to elucidate the role of SMAD4 in colorectal tumorigenesis and progression.
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Humans , Carcinogenesis , Chemotherapy, Adjuvant , Colorectal Neoplasms , Disease-Free Survival , Lymphocytes, Tumor-Infiltrating , Microsatellite Instability , Neoplasm Metastasis , Prognosis , Retrospective StudiesABSTRACT
BACKGROUND: Smad4 and PTEN are prognostic indicators for various tumor types. Smad4 regulates tumor suppression, whereas PTEN inhibits cell proliferation. We analyzed and compared the performance of Smad4 and PTEN for predicting the prognosis of patients with colorectal adenocarcinoma. METHODS: Combined expression patterns based on Smad4+/– and PTEN+/– status were evaluated by immunostaining using a tissue microarray of colorectal adenocarcinoma. The relationships between the protein expression and clinicopathological variables were analyzed. RESULTS: Smad4–/PTEN– status was most frequently observed in metastatic adenocarcinoma, followed by primary adenocarcinoma and tubular adenoma (p<.001). When Smad4–/PTEN– and Smad4+/PTEN+ groups were compared, Smad4–/PTEN– status was associated with high N stage (p=.018) and defective mismatch repair proteins (p=.006). Significant differences in diseasefree survival and overall survival were observed among the three groups (Smad4+/PTEN+, Smad4–/PTEN+ or Smad4+/PTEN–, and Smad4–/PTEN–) (all p<.05). CONCLUSIONS: Concurrent loss of Smad4 and PTEN may lead to more aggressive disease and poor prognosis in patients with colorectal adenocarcinoma compared to the loss of Smad4 or PTEN alone.
Subject(s)
Humans , Adenocarcinoma , Adenoma , Cell Proliferation , Colonic Neoplasms , DNA Mismatch Repair , PrognosisABSTRACT
Objective To evaluate the effects of capparis spinosa total alkaloid on transforming growth factor-β( TGF-β)/Smad4 signalling pathways in systemic sclerosis (SSc). Methods A total of 90 BALB/c mice were randomly divided into normal control group, model control group, penicillamine ( 125 mg·kg-1) group and Capparis spinosa total alkaloid low (225 mg·kg-1),medium (450 mg·kg-1) and high ( 900 mg·kg-1) dose group. Except for the normal control group,SSc mouse model was established by daily subcutaneous injection of bleomycin in the back of the mice.After the establishment of the model,Capparis spinosa total alkaloid emulsifiable paste was externally applied to Capparis spinosa total alkaloid group,ground substance was externally applied to the mice in normal control group and model control groups, and penicillamine was intragastrically administrated in the penicillamine group for 60 days,once daily.After the treatment,The expression of TGF-β1in skin tissue was detected by Western-blotting and the levels of actin / in receptor-like kinase / Smad4, nuclear factor-κB in skin tissue were measured by ELISA. Results The expression of TGF-β1was significantly decreased after administration of 225,450 and 900 mg·kg-1capparis spinosa total alkaloid, and the levels of ALK1 and Smad4 were significantly decreased after administration of 900 mg·kg-1capparis spinosa total alkaloid as compared with model control group (P<0.05 or P<0.01),but the content of NF-κB was not influenced (P>0.05). Conclusion Capparis spinosa total alkaloid can accommodate abnormal expression of TGF-β1/Smad4 signalling pathways in SSc.
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Objective This study intended to investigate the expression of TGF-β receptor1 (TβR1),smad2,smad3 and smad4 in bullae of lungs of PSP patients and to examine the role of these cytokines in the pathogenesis of PSP.Methods Bullae of thirty-four PSP patients who received standard video-assisted thoracic surgery were included as study group.Normal lung tissues around the bullae of lung of part of the 34 PSP specimens were used as a self-control.Normal lung tissues from ten patients without pneumothorax associated disease were used as a control.Immunohistochemical (IHC) staining of TβR1,smad2,smad3 and smad4 were performed on the normal lung tissue of control specimens and the bullae of lung of PSP specimens.Immunoreactivity was evaluated based on immunoreactive score(IRS).Statistical analyses were performed using t-test or Fisher exact test.Results (1)Overexpression ofTβR1(P＜0.01),smad2(P=0.023) and smad4(P=0.015) was detected in the bullae of lung of PSP patients compared with normal lung tissue around the bullae of lung.(2) TβR1 (P =0.012),smad2 (P =0.031) and smad4 (P ＜ 0.01) was significantly high-expressed in bullae of lung of PSP patients compared with normal lung tissue of control group.The expression of smad3 in the study group and the control group was not statistically significant(P ＞0.05).However,the absolute value of expression of smad3 in PSP bullae tissue was higher than that in control group(IRS 4.253 ± 1.719 vs.3.260 ± 2.213).Conclusion TβR1,smad2 and smad4 was significantly overexpressed in PSP lesions.These results suggest that an abnormal expression of TβR1,smad2 and smad4 may be involved in the pathogenesis of PSP.
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Objective To investigate the expression of Smad4 in gastric carcinoma and its relationship with clinicopathological characteristics. Methods Immunohistochemistry method was used to detect the expression of Smad4 in 85 gastric carcinoma tissue and 36 normal gastric mucosa from January 2014 to December 2016. Results (1)The positive expression rate of Smad4 in gastric carcinoma tissues was 35. 29% (30/ 85), which was significantly lower than that in normal gastric mucosa (91. 67% (33/ 36)),and the difference was statistically significant (χ2=32. 201,P<0. 001). (2) The expression of Smad4 was correlated with the depth ofinvasion(χ2=13. 626,P<0. 001),lymph nodes metastasis(χ2=7. 267,P=0. 007),TNM staging(χ2=18. 226,P<0. 001) and tumor differentiation level (χ2 = 9. 134, P= 0. 010) . ( 3) Multivariate unconditional logistic regression analysis showed that depth of invasion(OR=7. 892,95CI 1. 649-37. 790,P=0. 010),TNM staging ( OR=15. 042, 95CI 0. 026-0. 977, P=0. 005 ) and tumor differentiation level ( OR=15. 042, 95CI2. 292-98. 751, P = 0. 005 ) may be independent influencing factors for Smad4 expression in gastric carcinoma. Conclusion Smad4 may performed an important role during the progression of gastric carcinoma and may be a new biological marker of gastric carcinoma.
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Objective To explore the expressions of Smad4 and estrogen receptor (ER) and their interrelation,and the relationship with the clinicopathological features of breast cancer.Methods The immunohistochemical SP method was used to detect the expressions of Smad4 and ER in 50 case of invasive cancer,12 cases of carcinoma in situ and 15 cases of normal breast tissues.The differences in different clinical stages,differentiation degrees and nodal metastases were analyzed.The correlation between Smad4 and ER was explored.Results The positive expression rate of Smad4 in invasive cancer was 52.00％,which lower than that in normal breast tissue (93.33％),with a significant difference (x2 =8.329,P =0.004),positive expression rates of ER were 60.00％ and 40.00％ respectively,with no significant difference (x2 =1.868,P =0.172).The positive expression rates of Smad4 in carcinoma in situ and invasive cancer were 75.00％ and 52.00％ respectively,with no significant difference (x2 =2.082,P =0.149).The positive expression rates of ER were 58.33％ and 60.00％ respectively,with no significant difference (x2 =0.011,P =0.916).The positive expression of Smad4 was related to the TNM stage (x2 =6.392,P =0.011) and the lymph node metastasis (x2 =6.738,P =0.009),but it was not associated with the histologic grade (x2 =0.542,P =0.462).The positive expression of ER was related to the lymph node metastasis (x2 =4.133,P =0.042) and histologic grade (x2 =5.357,P =0.021),but it was not associated with the TNM stage (x2 =1.159,P =0.282).There was positive correlation between Smad4 and ER in breast cancer tissue (r =0.263,P =0.032).Conclusion Smad4 is expressed at lower level in breast cancer than in normal breast tissue.The expressions of Smad4 and ER are related to the different clinicopathological features of breast cancer with positive correlation.
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Objective To find out whether NOTCH receptors can serve as direct downstream targets of transforming growth factor β(TGF-β)/Smad4 signaling in endothelial cells.Methods Real-time PCR and Western blotting were performed to verify whether the expression of notch1 and notch4 was regulated by TGF-β pathway.Luciferase reporter assay was employed to investigate how the promoter of notch1 and notch4 was regulated by TGF-β.Then, ChIP assay was used confirm whether the promoter of notch1 and notch4 physically interacted with SMAD protein.Results TGF-β1 and bone morphogenetic protein 4 (BMP4) treatment increased the expression of both notch1 and notch4 at the transcriptional level.In addition, SMAD4 was physically associated with the SMAD binding sites on the notch4 promoter, which was largely enhanced under the treatment of TGF-β1 and BMP4.Importantly, TGF-β1 and BMP4 failed to transactivate notch4 in the absence of endogenous SMAD4 or the SMAD binding regions on the notch4 promoter.Conclusion The expression of NOTCH receptor can be directly up-regulated by SMAD4-mediated TGF-β/BMP signaling in cerebrovascular endothelial cells.
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AIM: To investigate the effects of microRNA (miRNA)-483-3p on the growth and migration of human glioma cell line A172 and its potential mechanisms.METHODS: The abundance of miRNA-483-3p in human embryonic kidney 293 cells and different human glioma cell lines (A172, U251 and SHG44) was measured by RT-qPCR.After down-regulation of miRNA-483-3p by transfection of inhibitor in the A172 cells, the cell viability, cell cycle distribution and cell migration were detected by CCK-8 assay, flow cytometry and Transwell assay, respectively.Furthermore, the protein levels of cell cycle-related molecules and epithelial-mesenchymal transition markers were measured by Western blot.Luciferase reporter assay was used to predict and verify the target gene of miRNA-483-3p.RESULTS: miRNA-483-3p was highly expressed in human glioma cells.Knockdown of miRNA-483-3p inhibited A172 cell viability, arrested cell cycle and decreased cell migration rate.Furthermore, the protein levels of cyclin D1, cyclin-dependent kinase 4, phoshorylated retinoblastoma protein, N-cadherin and vimentin were significantly decreased after knockdown of miRNA-483-3p, accompanied with the up-regulation of E-cadherin and β-catenin protein expression.Luciferase reporter assay demonstrated that Smad4 was a potential target gene of miRNA-483-3p.Down-regulation of Smad4 in the A172 cells transfected with miRNA-483-3p inhibitor partially reversed the effect of miRNA-483-3p on cell viability and migration.CONCLUSION: Knockdown of miRNA-483-3p restrains the growth and migration of A172 cells by targeting Smad4.
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Objective To discuss the expressions of VEGF ,EGFR and Smad4 in breast cancer tissue and their relationship with lymphatic metastasis .Methods 84 patients with breast cancer from June 2014 to June 2016 in our hospital were selected ,immuno-histochemical method was used to detect the expressions of VEGF ,EGFR and Smad4 ,and their relationship with lymphatic metas-tasis was analyzed .Results The positive expression rates of VEGF and EGFR were 22 .62% and 26 .19% respectively in breast cancer tissue ,which were notably higher than those in para-carcinoma tissue(22 .62% and 26 .19% respectively) ,and differences were statistically significant (P<0 .05) .Positive expression rate of Smad4 was 35 .71% in breast cancer tissue ,which was higher than that in para-carcinoma tissue(77 .38% ) ,and the difference was statistically significant (P< 0 .05) .The positive expression rates of EGFR and VEGF were 72 .92% and 70 .83% in Ⅲ + Ⅳ phase ,which were higher than those in Ⅰ + Ⅱ phase(50 .00% and 44 .44% ,respectively) ,differences were statistically significant(P<0 .05) .The positive expression of Smad2 was 25 .00% in Ⅲ +Ⅳphase ,which was lower than that in control group (50 .00% ) ,and the difference was statistically significant (P<0 .05) .The pos-itive expression rates of EGFR and VEGF were 77 .27% and 75 .00% in patients with lymphatic metastasis ,which were higher than those in patients without lymphatic metastasis (47 .50% and 42 .50% ) ,and differences were statistically significant (P< 0 .05) . The positive expression of Smad4 was 22 .73% in patients with lymphatic metastasis ,which was lower than that in patients without lymphatic metastasis (50 .00% ) ,and the difference was statistically significant (P<0 .05) .Pearson analysis showed that the posi-tive expression rates of EGFR and VEGF were positively associated with lymphatic metastasis (r1 =0 .382 ,r2 =0 .425 ,P<0 .05) , and the positive expression rate of Smad2 was negatively associated with lymphatic metastasis (r3 = -0 .468 ,P<0 .05) .Conclusion VEGF ,EGFR and Smad4 play an important role in the occurrence and development of breast cancer .The positive expression rates of EGFR and VEGF were positively associated with lymphatic metastasis ,and the positive expression rate of Smad2 was negatively associated with lymphatic metastasis ,which could have a guiding significance for prognosis of breast cancer .
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Objective:To study the effects of down-regulated Smad4 expression on the proliferation and apoptosis of breast carcinoma MCF-7 cells,and to explore their mechanisms.Methods:The human breast carcinoma MCF-7 cells and MDA-MB-231 cells were cultured in vitro.RT-PCR method was used to detect the expression levels of Smad4 mRNA in MCF-7 cells and MDA-MB-231 cells.The Smad4-shRNA plasmid and Scramble-shRNA plasmid were respectively stably transfected into the MCF-7 cells with high expression of Smad4.The experiment was divided into non-transfected MCF-7 cells (normal control) group,Smad4 gene silencing group,Scramble(negative control) group.The proliferation abilities of the cells in various groups were detected by CCK-8 method.The apoptotic rates of the cells in various groups were detected by flow cytometry.Real-time PCR method wasused to detect the mRNA expression levels of the proliferation-related genes CDKN1A,CDK1 and CDK2 and the apoptosisrelated genes Suvivin,bcl-2,caspase 3 and caspase 9.Results:The proliferation abilities of cells had no statistical significance between various groups (P＞0.05).The mRNA expression levels of CDKN1A,CDK1 and CDK2 in the cells had no statistical significance between various groups (P＞0.05).Compared with normal control group and negative control group,the apoptotic rate of the cells in Smad4 gene silencing group was significantly decreased (P＜0.01),the expression levels of Suvivin and bcl-2 mRNA in Smad4 gene silencing group were significantly increased (P＜0.01),and the mRNA expression levels of caspase 3 and caspase 9 in Smad4 gene silencing group were significantly decreased (P＜0.05).Conclusion:Smad4 could induce the apoptosis of MCF-7 cells by downregulating the expressions of Suvivin and bcl-2 and up-regulating the expressions of caspase 3 and caspase 9.
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Objective:To study the effects of down-regulated Smad4 expression on the proliferation and apoptosis of breast carcinoma MCF-7 cells,and to explore their mechanisms.Methods:The human breast carcinoma MCF-7 cells and MDA-MB-231 cells were cultured in vitro.RT-PCR method was used to detect the expression levels of Smad4 mRNA in MCF-7 cells and MDA-MB-231 cells.The Smad4-shRNA plasmid and Scramble-shRNA plasmid were respectively stably transfected into the MCF-7 cells with high expression of Smad4.The experiment was divided into non-transfected MCF-7 cells (normal control) group,Smad4 gene silencing group,Scramble(negative control) group.The proliferation abilities of the cells in various groups were detected by CCK-8 method.The apoptotic rates of the cells in various groups were detected by flow cytometry.Real-time PCR method wasused to detect the mRNA expression levels of the proliferation-related genes CDKN1A,CDK1 and CDK2 and the apoptosisrelated genes Suvivin,bcl-2,caspase 3 and caspase 9.Results:The proliferation abilities of cells had no statistical significance between various groups (P＞0.05).The mRNA expression levels of CDKN1A,CDK1 and CDK2 in the cells had no statistical significance between various groups (P＞0.05).Compared with normal control group and negative control group,the apoptotic rate of the cells in Smad4 gene silencing group was significantly decreased (P＜0.01),the expression levels of Suvivin and bcl-2 mRNA in Smad4 gene silencing group were significantly increased (P＜0.01),and the mRNA expression levels of caspase 3 and caspase 9 in Smad4 gene silencing group were significantly decreased (P＜0.05).Conclusion:Smad4 could induce the apoptosis of MCF-7 cells by downregulating the expressions of Suvivin and bcl-2 and up-regulating the expressions of caspase 3 and caspase 9.
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Objective To determine the effect of ostecytic TGF-β/Smad4 signaling on osteoblastic and osteoclastic differentiation in bone marrow stromal cells (BMSCs).Methods Mice with osteocytic TGF-β/Smad4 conditional knock down (Smad4ot CKD) were generated as previously by crossing DMP1-8kb-Cre mice with Smad4lox(ex8)/lox(ex8) mice.The osteocytes were isolated from tibial and femoral diaphysis and co-cultured with wild-type BMSCs.ALP staining, Alizarin red staining and TRAP staining were performed to show osteoblastic and osteoclastic differentiation.Then, their marker genes were detected by qPCR and proteins measured by Western blot.ResultsThe expression of Runx2 and Osterix were reduced in smad4 CKDot co-cultured with BMSCs compared with controls(P<0.01).Similarly, the specific markers of osteoblastic differentiation were decreased (P<0.01).Additionally, the expression of RANKL was not significantly changed in with BMSCs.However, OPG was highly expressed incontrol group compared with smad4 CKD in co-cultured group (P<0.05).Thus, the radio of RANKL/OPG was significantly reduced (P<0.05).Furthermore, the expression of RANK was inhibited.Conclusions The terminally-differentiated osteocytes are the cells regulating bone metabolism, while down-regulation of osteocytic-TGF-β/Smad4 inhibits BMSC osteoblastic and osteoclastic differentiation.
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The transforming growth factor beta (TGF-beta) is a cytokine that plays crucial roles in the regulation of angiogenesis, immune response, proliferation, migration and apoptosis of cells. In addition, it can inhibit cell progression and stimulate apoptosis in early stages of cancer. TGF-beta is a multifunctional homodimeric protein secreted by various cell lines, which have three different isoforms: TGF-beta1, TGF-beta2 and TGF-beta3. In normal conditions, TGF-beta1 activates some tumor suppressor cell signaling pathways that inhibit proliferation and are involved in cell migration, differentiation and apoptosis. However, in more advanced stages of cancer, when TGF-beta1 is altered, it acts as a promoter of tumorigenesis and may cause: 1) increased TGF-beta1, 2) overexpression of TGF-beta1 receptors (TbetaR), 3) TbetaR mutations, and 4) downregulation of TGF-beta receptor. In oral squamous cell carcinoma, the path is altered especially at the level of transmembrane receptors, with the TbetaR-II and TbetaR-III subtypes being the most affected. However, there is little information on the prognostic role it plays in the various types of cancers. It is important to study the signaling pathways of TGF-beta in order to develop techniques that may help detect their alterations and restore their normal operation. The objective of this review is to describe the alterations of TGF-beta in oral squamous cell carcinoma.
El factor de crecimiento transformante beta (TGF-beta) es una citocina que cumple funciones fundamentales en la regulación de la angiogénesis, respuesta inmune, proliferación, migración y apoptosis celular. Además, puede inhibir la progresión celular y estimular la apoptosis en etapas tempranas del cáncer. El TGF-beta es una proteína homodimérica multifuncional secretada por diversas líneas celulares, que presentan 3 isoformas: TGF-beta1, TGF-beta2 y TGF-beta3. En condiciones normales TGF-beta1 activa a algunas vías de señalización celular supresoras de tumores que inhiben la proliferación, y participan en la migración, diferenciación y apoptosis. Sin embargo, cuando esta se ve alterada, en etapas más avanzadas del cáncer actúa como promotor de la tumorogénesis, pudiendo producir: 1) aumento del TGF-beta1, 2) sobre expresión de los receptores del TGF-beta1 (TbetaR), 3) mutaciones de TbetaR, y 4) falla en la regulación negativa de TbetaR. En el carcinoma oral de células escamosas, la vía se ve alterada especialmente a nivel de sus receptores transmembranales, siendo los subtipos TbetaR-II y TbetaR-III los más afectados. Sin embargo, es escasa la información sobre el rol pronóstico que juega en los diversos tipos de cánceres. Es importante estudiar las vías de señalización de TGF-beta para desarrollar técnicas que detecten sus alteraciones y restauren el funcionamiento del sistema. El objetivo de esta revisión es describir las alteraciones de TGF-beta en carcinoma oral de células escamosas.
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Humans , Carcinoma, Squamous Cell/metabolism , Mouth Neoplasms/metabolism , Transforming Growth Factor beta1/metabolism , /metabolismABSTRACT
Objective To investigate miR-146a-Smad4 expression during ultraviolet A(UVA)-induced photoaging of human skin fibroblasts (HSFs), and to evaluate effects of up-regulation of miR-146a expression on its target gene Smad4 and cell photoaging. Methods HSFs were isolated from the prepuce, and subjected to primary culture and maintained up to 10th passage. Then, the HSFs were classified into 4 groups: blank control group receiving no treatment, UVA group irradiated with 10 J/cm2 UVA, miR-146a group transfected with a lentiviral vector expressing miR-146a, UVA+ miR-146a group transfected with the lentiviral vector expressing miR-146a followed by UVA radiation. Real time PCR was performed to measure miR-146a expression in HSFs in the UVA group on day 0, 3, 7 and 14 after UVA radiation.Fluorescence microscopy was carried out to estimate transfection efficiency on day 7 and 14 in the miR-146a group after transfection, and real time PCR was performed to quantify miR-146a expression in these cells. Methyl thiazolyl tetrazolium (MTT)assay was conducted to evaluate proliferative activity of HSFs, real time PCR to quantify mRNA expressions of photoaging-related genes p53, p21 and p16, and Western blot analysis to measure Smad4 protein expression in these cells. Statistical analysis was carried out by using repeated-measures analysis of variance and factorial design analysis of variance. Results Repeated-measures analysis of variance showed that the expression of miR-146a decreased over time in both the UVA group and blank control group(F = 213.840, P 0.05). Factorial design analysis of variance showed that UVA radiation had an inhibitory effect on the proliferative activity of HSFs (P 0.05). Real time PCR and Western blot analysis both revealed that UVA radiation could increase the expressions of p53, p21 and p16 mRNAs as well as Smad4 protein(all P 0.05). Conclusion The expression of miR-146a is inhibited in UVA-induced photoaged HSFs, and its up-regulation may counteract cell photoaging by suppressing Smad4 expression in, and promoting proliferation of, photoaged HSFs.
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Objective:To investigate the expressions of Smad2 and Smad4 in breast carcinoma tissue,and to analyze their relationships with oncogenesis and development of breast carcinoma and significances.Methods:Fifty-three samples of breast ductal carcinoma tissue and 50 samples of surrounding normal tissue were selected.The expression levels of Smad2 and Smad4 in cancer tissue and surrounding normal tissue were detected with immunohistochemical S-P method,and the relationships between the expression levels of Smad2 and Smad4 and the clinicopathologic parameters of breast carcinoma were evaluated.Results:The expression level of Smad2 protein in the breast carcinoma tissue was significantly higher than that in the surrounding normal tissue (z = - 2.08,P 0.05;r=-0.077,P >0.05),tumor size (r= 0.128,P >0.05;r=0.133,P >0.05),lymph node invasion (r =0.163,P >0.05;r =0.006 P >0.05),distant metastasis (r =0.113,P >0.05;r = 0.126,P > 0.05),ER expression (r = 0.056,P > 0.05;r = 0.047,P > 0.05) and PR expression (r=0.129,P >0.05;r=0.107,P >0.05).However,the expression levels of Smad2 and Smad4 were negatively correlated with the expression of HER2 (r = - 0.388,P < 0.01;r = - 0.360,P < 0.01 ) and pathological grade (r = - 0.331,P < 0.05;r = - 0.388,P < 0.01 ).The expression of Smad2 was positively correlated to the expression of Smad4 in breast carcinoma (r=-0.83,P <0.01).Conclusion:The expressions of Smad2 and Smad4 may play an important role in the development of breast carcinoma,and they may be used as the potential biological markers for evaluating the degree of malignancy and prognosis of breast carcinoma.
ABSTRACT
OBJECTIVE: To investigate the effect of Smad4 on the fibrosis of tendon derived fibroblasts (TDFs) induced by transforming growth factor β1(TGF-β1) by targeted regulation of miRNA219-5P (miR219-5P). METHODS: The tendons donated by the volunteers were harvested to isolate and culture TDFs. The 3rd generation cells were used for experiment. Chemically synthesized miR219-5P mimics, miR219-5P inhibitor, and negative control sequences were transfected into TDFs. The gene expression of miR219-5P in TDFs was detected by real-time PCR, and the protein expression of Smad4 in TDFs was detected by Western blot at 48 hours after transfection. The combining sites of miR219-5P and Smad4 in 3'UTR district were predicted by informatics software. Wild type and mutant type reporter gene expression vectors were constructed and then targeted verification was carried out by the luciferase reporter gene test. Transfected TDFs were then induced by TGF-β1. The proliferation activity of the cells were measured by the cell counting kit 8 after culturing for 24, 48, and 72 hours. The expressions of fibrosis related proteins in TDFs were detected by Western blot at 72 hours. RESULTS: After TDFs were transfected by miR219-5P mimics, miR219-5P expression was significantly up-regulated, but the expressions of Smad4 was decreased subsequently (P0.05). Cell proliferation and the fibrosis related proteins were increased in TGF-β1 induced TDFs, however, decreased in TGF-β1 induced TDFs after transfected by miR219-5P inhibitor (P<0.01). CONCLUSIONS: miR219-5P can significantly inhibit fibrosis of TDFs induced by TGF-β1 by down-regulating Smad4 expression.