38 research outputs found
Upregulation of SMAD4 inhibits thyroid cancer cell growth via MAPK/JNK pathway repression
Purpose: To investigate whether the effect of mothers against decapentaplegic homolog 4 (SMAD4) on thyroid cancer cell survival was via the MAPK/JNK pathway.
Methods: Papillary thyroid cancer (TPC)-1 cells were cultured and transfected with SMAD4 overexpression plasmid or siRNA to achieve SMAD4 overexpression or knockdown, respectively. In TPC-1 cells, the mRNA and protein expression levels of SMAD4, mitogen-activated protein kinase (MAPK), and c-Jun N-terminal kinase (JNK) were quantified using reverse transcription-quantitative polymerase chain reaction and western blotting, respectively. Cell viability and apoptosis were measured using MTT assay and flow cytometry, respectively. MAPK and JNK inhibitors (U0126 and SP600125) were used for rescue experiments. The sensitivity of TPC-1 cells to chemotherapeutic drugs, cisplatin and doxorubicin, was also assessed.
Results: A reduction in viability and an enhancement in apoptosis (p < 0.01) were found when SMAD4 was overexpressed in TPC-1 cells. Knockdown of SMAD4 elicited opposite results (p < 0.01). Overexpression of SMAD4 caused a decrease in the activation of MAPK and JNK, as evidenced by lower levels of phosphorylated MAPK and phosphorylated JNK (p < 0.05). Results from rescue experiments indicate that the increase in cell viability after SMAD4 knockdown was reversed by MAPK/JNK inhibitors (p < 0.05 and p < 0.01). Finally, overexpression of SMAD4 increased cytotoxic susceptibility of thyroid cancer cells to cisplatin/doxorubicin.
Conclusion: These results indicate that SMAD4 inhibits thyroid cancer cell growth via inactivation of MAPK/JNK pathway. Overexpression of SMAD4 also increased thyroid cancer cell sensitivity to cisplatin/doxorubicin
Disruption of Smad7 Promotes ANG II-Mediated Renal Inflammation and Fibrosis via Sp1-TGF-β/Smad3-NF.κB-Dependent Mechanisms in Mice
Smad7 is an inhibitory Smad and plays a protective role in obstructive and diabetic kidney disease. However, the role and mechanisms of Smad7 in hypertensive nephropathy remains unexplored. Thus, the aim of this study was to investigate the role and regulatory mechanisms of Smad7 in ANG II-induced hypertensive nephropathy. Smad7 gene knockout (KO) and wild-type (WT) mice received a subcutaneous infusion of ANG II or control saline for 4 weeks via osmotic mini-pumps. ANG II infusion produced equivalent hypertension in Smad7 KO and WT mice; however, Smad7 KO mice exhibited more severe renal functional injury as shown by increased proteinuria and reduced renal function (both p<0.05) when compared with Smad7 WT mice. Enhanced renal injury in Smad7 KO mice was associated with more progressive renal fibrosis with elevated TGF-β/Smad3 signalling. Smad7 KO mice also showed more profound renal inflammation including increased macrophage infiltration, enhanced IL-1β and TNF-α expression, and a marked activation of NF-κB signaling (all p<0.01). Further studies revealed that enhanced ANG II-mediated renal inflammation and fibrosis in Smad7 KO mice were also associated with up-regulation of Sp1 but downregulation of miR-29b expression. Taken together, the present study revealed that enhanced Sp1-TGF-β1/Smad3-NF-κB signaling and loss of miR-29 may be mechanisms by which deletion of Smad7 promotes ANG II-mediated renal fibrosis and inflammation. Thus, Smad7 may play a protective role in ANG II-induced hypertensive kidney disease. © 2013 Liu et al.published_or_final_versio
Unblinding at disease progression in double-blinded randomized controlled cancer drug clinical trials: A controversy requires more attention
Unblinding at disease progression in double-blinded randomized controlled cancer drug clinical trials is ethical to the patient by ensuring optimal subsequent treatment, but the effect of study treatment on overall survival may be confounded. The views of science and ethics in this issue are controversial and the unblinding procedures should be well-designed. In real world settings, a lack of use of this unblinding process in protocol was observed in the analysis of 134 double-blind randomized controlled anticancer drug clinical trials conducted in China from 2018 to 2021. Unblinding at disease progression was allowed in only 26 (18.2%) trials. Among them, Only 9 (34.6%) trials involved patient-level unblinding. None of the 134 included trials accounted for the risk of blind-maintenance after disease progression. Based on the analysis and case studies, we believe that unblinding at disease progression should be stated in the protocol when the treatment assignment directly affected the choice of subsequent regimen, in which the drug category, control group design, standard of care of further-line therapy and primary endpoint together play a role. When unblinding at disease progression is adopted, the sensitivity analytics are recommended to understand the true effect of study drug on overall survival. The notification of treatment allocation after unblinding and the informed consent also require attention. A decision-making framework is established to help understand this controversy, which should be carefully discussed by the investigator and the sponsor
Deficiency of Smad7 Enhances Cardiac Remodeling Induced by Angiotensin II Infusion in a Mouse Model of Hypertension
Smad7 has been shown to negatively regulate fibrosis and inflammation, but its role in angiotensin II (Ang II)-induced hypertensive cardiac remodeling remains unknown. Therefore, the present study investigated the role of Smad7 in hypertensive cardiopathy induced by angiotensin II infusion. Hypertensive cardiac disease was induced in Smad7 gene knockout (KO) and wild-type (WT) mice by subcutaneous infusion of Ang II (1.46 mg/kg/day) for 28 days. Although equal levels of high blood pressure were developed in both Smad7 KO and WT mice, Smad7 KO mice developed more severe cardiac injury as demonstrated by impairing cardiac function including a significant increase in left ventricular (LV) mass (P<0.01),reduction of LV ejection fraction(P<0.001) and fractional shortening(P<0.001). Real-time PCR, Western blot and immunohistochemistry detected that deletion of Smad7 significantly enhanced Ang II-induced cardiac fibrosis and inflammation, including upregulation of collagen I, α-SMA, interleukin-1β, TNF-α, and infiltration of CD3+ T cells and F4/80+ macrophages. Further studies revealed that enhanced activation of the Sp1-TGFβ/Smad3-NF-κB pathways and downregulation of miR-29 were mechanisms though which deletion of Smad7 promoted Ang II-mediated cardiac remodeling. In conclusions, Smad7 plays a protective role in AngII-mediated cardiac remodeling via mechanisms involving the Sp1-TGF-β/Smad3-NF.κB-miR-29 regulatory network. © 2013 Wei et al.published_or_final_versio
Bone Marrow-derived Macrophage-Myofibroblast Transition: A Novel Pathway in Peritoneal Fibrosis
Loss of angiotensin-converting enzyme 2 enhances TGF-Î’/Smad-mediated renal fibrosis and NF-ÎşB-driven renal inflammation in a mouse model of obstructive nephropathy
It is known that angiotensin (Ang)-converting enzyme (ACE) 2 catalyzes Ang II to Ang 1-7 to prevent the detrimental effect of Ang II on blood pressure, renal fibrosis, and inflammation. However, mechanisms of renoprotective role of Ace2 remain largely unclear. The present study tested the hypothesis that deficiency of Ace2 may accelerate intrarenal Ang II-mediated fibrosis and inflammation independent of blood pressure in a model of unilateral ureteral obstructive (UUO) nephropathy induced in Ace2 +y and Ace2 -/y mice. Results showed that both Ace2 +y and Ace2 -/y mice had normal levels of blood pressure and plasma Ang II/Ang 1-7. In contrast, deletion of ACE2 resulted in a fourfold increase in the ratio of intrarenal Ang II/Ang 1-7 in the UUO nephropathy. These changes were associated with the development of more intensive tubulointerstitial fibrosis (α-SMA, collagen I) and inflammation (TNF-α, IL-1β, MCP-1, F4/80 + cells, and CD3 +T cells) in Ace2 -/y mice at day 3 (all P≤0.05) after UUO, becoming more profound at day 7 (all P≤0.01). Enhanced renal fibrosis and inflammation in the UUO kidney of Ace2 -/y mice were largely attributed to a marked increase in the intrarenal Ang II signaling (AT1-ERK1/2 mitogen-activated protein kinase), TGF-β/Smad2/3, and NF-κB signaling pathways. Further studies revealed that enhanced TGF-β/Smad and NF-κB signaling in the UUO kidney of Ace2 -/y mice was associated with upregulation of an E3 ligase Smurf2 and a loss of renal Smad7. In conclusion, enhanced Ang II-mediated TGF-β/Smad and NF-B signaling may be the mechanisms by which loss of Ace2 enhances renal fibrosis and inflammation. Smad7 ubiquitin degradation mediated by Smurf2 may be a central mechanism by which Ace2 -/y mice promote TGF-Β/Smad2/3-mediated renal fibrosis and NF-κB-driven renal inflammation in a mouse model of UUO nephropathy. © 2012 USCAP, Inc All rights reserved.link_to_OA_fulltex
Upregulation of TSHR, TTF-1, and PAX8 in Nodular Goiter Is Associated with Iodine Deficiency in the Follicular Lumen
Objective. It has been testified that iodine regulates thyroid function by controlling thyroid-restricted genes expression and is closely related to diffuse goiter and thyroid dysfunction. However, the effects of follicular lumen iodine, the main form of iodine reserve in the body, on thyroid-restricted genes in nodular goiter are poorly understood. In this study, correlations between follicular lumen iodine and the expressions of thyroid stimulating hormone receptor (TSHR), its transcription factors TTF-1, and PAX8 in nodular goiter were investigated. Patients. In this study, 30 resection specimens clinically histopathologically confirmed to have nodular goiter and 30 normal thyroid specimens from adjacent tissues of nodular goiter are used. Measurement. Western blot immunohistochemistry was performed to assay TSHR, TTF-1, and PAX8 in thyrocytes of nodular goiter as well as in extranodular normal thyroid tissues. Meanwhile, follicular lumen iodine of both nodular goiter and extranodular normal thyroid tissues was detected as well. Results. The TSHR, TTF-1, and PAX8 in nodular goiter were significantly higher than those in the controls. The iodine content in nodular goiter was significantly lower than those in control tissues. Conclusion. Upregulation of TSHR, TTF-1, and PAX8 is associated with low follicular lumen iodine content in nodular goiter
Experimental study of controlling tip clearance flow in a pump-jet propulsor
ObjectiveThis paper aims to suppress the adverse effects of tip clearance flow on the hydrodynamic performance and unsteady excitation force of a pump-jet propulsor. MethodAs for the pre-swirl stator pump-jet propulsor, an annular flexible seal structure closely matched with a rotor tip ring is used to study the validity of suppressing the clearance flow on the rotor tip. The rotor thrust and torque of the propulsor are measured by keeping the shroud approximately rigidly fixed, enabling the rotor open water efficiency to be obtained. In addition, the point of cavitation inception at each design condition is observed and recorded carefully with the help of a high-power stroboscope, and the cavitation inception curves of the propulsor with/without tip clearance are obtained through calculation. Finally, tests of shaft vibration acceleration on the pump-jet propulsor with/without tip clearance are conducted under conditions of cavitation and non-cavitation in order to evaluate the effects of diminishing tip clearance. ResultsThe results show that the thrust and torque of the rotor of the pump-jet propulsor with a flexible seal structure are significantly increased, which in turn renders open water efficiency significantly increased at low and medium advance coefficients, unchanged near the design point and slightly decreased at the high advance coefficient. Moreover, the cavitation performance of the pump-jet propulsor without clearance is better at a wide range of advance coefficient, 0.85 <J< 1.40, near the design point. In addition, compared with a pump-jet propulsor with clearance, the amplitude of axial vibration acceleration of the shaft equipped with a pump-jet propulsor without tip clearance is significantly reduced at most characteristic frequencies.ConclusionThe results of this study demonstrate that using a flexible seal structure to suppress tip clearance flow has a positive effect on improving open water efficiency at low and medium advance coefficients, optimizing cavitation performance at the design point and suppressing the shafting vibration of the propulsor
Systematic Review of the Methodology Quality in Lung Cancer Screening Guidelines
Background and objective Lung cancer is the most common malignancy and screening can decrease the mortality. High quality screening guideline is necessary and important for effective work. Our study is to review and evaluate the basic characteristics and methodology quality of the current global lung cancer screening guidelines so as to provide useful information for domestic study in the future. Methods Electronic searches were done in English and Chinese databases including PubMed, the Cochrane Library, Web of Science, Embase, CNKI, CBM, Wanfang, and some cancer official websites. Articles were screened according to the predefined inclusion and exclusion criteria by two researchers. The quality of guidelines was assessed by AGREE II. Results At last, a total of 11 guidelines with methodology were included. The guidelines were issued mainly by USA (81%). Canada and China developed one, respectively. As for quality, the average score in the “Scale and objective” of all guidelines was 80, the average score in the “Participants” was 52, the average score in the “rigorism” was 50, the average score in the “clarity” was 76, the average score in the “application” was 43 and the average score in the “independence” was 59. The highest average score was found in 2013 and 2015. Canada guideline had higher quality in six domains. 7 guidelines were evaluated as A level. Conclusion The number of clinical guidelines showed an increasing trend. Most guidelines were issued by developed countries with heavy burden. Multi-country contribution to one guideline was another trend. Evidence-based methodology was accepted globally in the guideline development