SMAD4 variants and its genotype-phenotype correlations to juvenile polyposis syndrome.

BACKGROUND: Juvenile polyposis syndrome (JPS), a rare autosomal dominant syndrome, affects one per 100 000 births, increasing lifetime cancer risk by 9 - 50%. Around 40-60% of JPS cases are caused by disease-causing variants (DCV) in SMAD4 or BMPR1A genes, of which SMAD4 accounts for 20-30%. OBJECTIVES: To characterise genotype-phenotype correlations between sites and types of variants within SMAD4 to JPS phenotypes, to inform diagnosis, screening, and management of JPS. SEARCH METHODS: Online search databases utilised included Ovid MEDLINE, Embase Classic + Embase and PubMed, using search terms classified by MeSH on Demand. Adjacency operators, word truncation and Boolean operators were employed. 110 articles were included in the review, collating 291 variants from the literature. RESULTS: In SMAD4 + JPS patients, most variants are located around SMAD4's MH2 domain (3' end). Extracolonic involvement, massive gastric polyposis and a more aggressive phenotype have been associated with SMAD4 + JPS, predisposing to gastric cancer. This has contributed to an overall higher incidence of GI cancers compared to other genes causing JPS, with DCVs mostly all within the MH2 domain. Genetically related allelic disorders of SMAD4 also have variants in this region, including hereditary haemorrhagic telangiectasia (HHT) alongside SMAD4 + JPS, and Myhre syndrome, independent of JPS. Similarly, with DCVs in the MH2 domain, Ménétrier's disease, hypertrophic osteoarthropathy and juvenile idiopathic arthritis have been seen in this population, whereas cardiac pathologies have occurred both alongside and independently of SMAD4 + JPS with DCVs in the MH1 domain. CONCLUSION: Truncating and missense variants around the MH2 region of SMAD4 are most prevalent and pathogenic, thus should undergo careful surveillance. Given association with extracolonic polyposis and higher GI cancer risk, endoscopic screening should occur more frequently and at an earlier age in SMAD4 + JPS patients than in patients with other causative genes, with consideration of Ménétrier's disease on upper GI endoscopy. In addition, HHT should be evaluated within 6 months of diagnosis, alongside targeted clinical examination for extraintestinal manifestations associated with SMAD4 + JPS. This review may help modify clinical diagnosis and management of SMAD4 + JPS patients, and aid pathogenicity classification for SMAD4 DCVs through a better understanding of the phenotypes.

Methylation status, mRNA and protein expression of the SMAD4 gene in patients with non-melanocytic skin cancers.

BACKGROUND: SMAD4 is a potent tumor suppressor. SMAD4 loss increases genomic instability and plays a critical role in the DNA damage response that leads to skin cancer development. We aimed to investigate SMAD4 methylation effects on mRNA and protein expression of SMAD4 in cancer and healthy tissues from patients with basal cell carcinoma (BCC), cutaneous squamous cell carcinoma (cSCC), and basosquamous skin cancer (BSC). METHODS AND RESULTS: The study included 17 BCC, 24 cSCC and nine BSC patients. DNA and RNA were isolated from cancerous and healthy tissues following punch biopsy. Methylation-specific polymerase chain reaction (PCR) and real-time quantitative PCR methods were used to examine SMAD4 promoter methylation and SMAD4 mRNA levels, respectively. The percentage and intensity of staining of the SMAD4 protein were determined by immunohistochemistry. The percentage of SMAD4 methylation was increased in the patients with BCC (p = 0.007), cSCC (p = 0.004), and BSC (p = 0.018) compared to the healthy tissue. SMAD4 mRNA expression was decreased in the patients with BCC (p˂0.001), cSCC (p˂0.001), and BSC (p = 0.008). The staining characteristic of SMAD4 protein was negative in the cancer tissues of the patients with cSCC (p = 0.00). Lower SMAD4 mRNA levels were observed in the poorly differentiated cSCC patients (p = 0.001). The staining characteristics of the SMAD4 protein were related to age and chronic sun exposure. CONCLUSIONS: Hypermethylation of SMAD4 and reduced SMAD4 mRNA expression were found to play a role in the pathogenesis of BCC, cSCC, and BSC. A decrease in SMAD4 protein expression level was observed only in cSCC patients. This suggests that epigenetic alterations to the SMAD4 gene are associated with cSCC. TRIAL REGISTRATION: The name of the trial register: SMAD4 Methylation and Expression Levels in Non-melanocytic Skin Cancers; SMAD4 Protein Positivity. The registration number: NCT04759261 ( https://clinicaltrials.gov/ct2/results?term=NCT04759261 ).

Latency-Associated Transcript-Derived MicroRNAs in Herpes Simplex Virus Type 1 Target SMAD3 and SMAD4 in TGF-ß/Smad Signaling Pathway.

Background: During its latent infection, hepatic stellate cell (HSV-1) produces only a micro RNA (miRNA) precursor called latency-associated transcript (LAT), which encodes six distinct miRNAs. Recent studies have suggested that some of these miRNAs could target cellular mRNAs. One of the key cell signaling pathways that can be affected by HSV-1 is the TGF-ß/Smad pathway. Herein, we investigated the potential role of the LAT as well as three LAT-derived miRNAs in targeting SMAD3 and SMAD4, as two main mediators in TGF-ß/Smad. Methods: The selection of LAT-derived miRNAs was based on the search results obtained from an online miRNA prediction tool. HEK293T cells were transfected with each miRNA-expressing lentivector and with the construct-expressing LAT. To survey the effect of LAT on the expression of pro-fibrotic markers, we transfected LX-2 cells with LAT construct. The impact of viral miRNA overexpression on SMADs and fibrotic markers was measured by quantitative PCR and luciferase assays. Results: Among the LAT-derived miRNAs, miR-H2, miR-H3, and miR-H4 were selected for the study. Our results demonstrated that while miR-H2 binds to both SMAD mRNAs, miR-H3 and miR-H4 inhibit only the expression of the SMAD4 and SMAD3, respectively. Transfection of the LX-2 with LAT also decreased pro-fibrotic genes expression. Conclusion: Our findings display that LAT negatively regulates TGF-ß/Smad through targeting SMAD3 and SMAD4 by its miRNAs. These viral miRNAs can also contribute to the development of therapeutic interventions in diseases for which prevention or treatment can be achieved through targeting TGF-ß pathway.

Poorly differentiated histologic grade correlates with worse survival in SMAD4 negative pancreatic adenocarcinoma patients.

BACKGROUND AND OBJECTIVES: This study investigated the influence of the transcription factor SMAD4 on overall patient survival following surgical resection of pancreatic ductal adenocarcinoma (PDAC). METHODS: The SMAD4 status of 125 surgically resected PDAC specimens at a large academic center from 2014 to 2017 was routinely determined prospectively and correlated with clinicopathologic characteristics and overall survival. RESULTS: SMAD4 loss was identified in 62% of patients and was not associated with overall survival (OS). On multivariate Cox proportional hazards survival analysis, histologic grade was the best predictor of survival in the SMAD4(-) population (adjusted hazard ratio = 4.8, p < .0001). In the SMAD4(+) population, histologic grade was not associated with survival on multivariate analysis. In the SMAD4(-) population, median OS for well/moderately differentiated patients and poorly differentiated patients was 39.6 and 8.6 months, respectively. CONCLUSION: In this large cohort of resected PDAC, routine SMAD4 assessment identified a subpopulation of patients with SMAD4(-) and histologically poorly differentiated tumors that had significantly poor prognosis with median OS of 8.6 months. Characterization of the role of SMAD4 within the context of poorly differentiated tumors may help settle the controversy regarding SMAD4 in PDAC and lead to identification of personalized therapeutic strategies for subgroups of PDAC.

Pokemon Inhibits Transforming Growth Factor ß-Smad4-Related Cell Proliferation Arrest in Breast Cancer through Specificity Protein 1.

PURPOSE: Pokemon, also known as ZBTB7A, belongs to the POZ and Krüppel (POK) family of transcription repressors and is implicated in tumor progression as a key proto-oncogene. This present study aimed at determining the mechanism by which Pokemon inhibits transforming growth factor ß (TGFß)-Smad4 pathway-dependent proliferation arrest of breast cancer cells via specificity protein 1 (SP1). METHODS: Over-expressing plasmid or small interfering RNA (siRNA) transfection was used to regulate Pokemon levels. The EdU incorporation assay, MTS assay, and clone formation were used to identify the inhibitory effect of Pokemon siRNA on cell proliferation. Quantitative real-time polymerase chain reaction assay confirmed that Pokemon deletion inhibited the expression of proliferation-associated genes. The dual-luciferase reporter assay, electrophoretic mobility shift assay, and co-immunoprecipitation assay were used to analyze binding between Pokemon, Smad4, and SP1. RESULTS: Pokemon deletion induced proliferation arrest of breast cancer cells and inhibited the expression of proliferation-associated genes, especially Smad4. Pokemon bound with SP1 to interdict Smad4 promoter activity. Information on clinical samples was obtained from The Cancer Genome Atlas data, in which the Pokemon mRNA levels showed a negative correlation with Smad4 levels in different subtypes of breast cancer in two independent datasets. CONCLUSION: We demonstrated that Pokemon binds to SP1 to down-regulate Smad4 expression, thereby promoting proliferation of breast cancer cells. This suggests that Pokemon is a potential TGFß-signaling participant in breast cancer progression.

Intratumoral Heterogeneity of SMAD4 Immunohistochemical Expression and Its Role in Prediction of Recurrence Pattern in Patients with Resectable Pancreatic Cancer.

BACKGROUND: The aim of our study was to evaluate consistency of SMAD4 expression in different tumor areas and its correlation with recurrence pattern in patients after resection for pancreatic cancer (PC). METHODS: Records of patients who underwent resection for nonmetastatic PC between 2001 and 2015 were analyzed. Formalin-fixed, paraffin-embedded tissue sections from different areas of primary tumor and lymph node metastases were analyzed immunohistochemically (IHC) for SMAD4 expression using TMA technology. RESULTS: SMAD4 expression was assessed in 356 tissue sections obtained from 91 patients. SMAD4 expression was positive in all assessed tumor slides only in 7 of 26 patients (26.9%). There were 54 recurrences (9 locoregional, 41 distant, and 4 both local and distant) with median follow-up of 21.7 months. There was no correlation between SMAD4 expression and locoregional recurrence pattern (p = 0.30). SMAD4 status influenced neither distant recurrence-free survival (p = 0.99) nor overall survival (p = 0.13). CONCLUSIONS: Different areas inside primary tumor and lymph node metastases express SMAD4 heterogeneously. SMAD4 IHC expression is not a biomarker of the recurrence pattern after surgical resection for PC.

Expression of TGF-beta receptor 1 and Smads in the tissues of primary spontaneous pneumothorax.

BACKGROUND: Primary spontaneous pneumothorax (PSP) is a common disease which is often caused by the rupture of bullae in the lungs. The underlying pathogenesis of PSP remains unclear. Some molecules may be involved in the development of PSP potentially. The aim of this study was to investigate the expression of TGF-beta receptor 1 (TßR1), Smad2, Smad3 and Smad4 in the resected bullae of patients with PSP. METHODS: From May 2015 to May 2016, 34 patients with PSP underwent video-assisted thoracoscopic surgery (VATS) bullectomy. Immunohistochemistry was performed to identify the expression of TßR1, Smad2, Smad3 and Smad4 in the resected pulmonary bullae tissues. The levels of these cytokines were calculated by immunoreactivity scoring system (IRS). Ten patients without pneumothorax associated disease were selected as the control group. RESULTS: The analysis showed that the expression levels of TßR1, Smad2 and Smad4 were significantly higher in bullae tissues of patients with PSP than that in normal lung tissues (P=0.012, 0.031, 0.000 respectively). There was no significant difference between the expression level of Smad3 in bullae tissue of PSP patients and that in normal lung tissues of the control group (P=0.140). However, the absolute quantity of Smad3 expression in PSP bullae tissues was (4.2529±1.7193), scored by the IRS, which is higher than that in the control lung tissues (3.2600±2.2132). Also, the expression of TßR1, Smad2, Smad3 and Smad4 were not showed correlation with the clinical characteristics of PSP patients, such as age, sex, body mass index (BMI), recurrence and side of pneumothorax. CONCLUSIONS: TßR1, Smad2 and Smad4 highly expressed in bullae tissues of PSP patients. Our findings suggested that TßR1, Smad2 and Smad4 may be related to the development of PSP bullae.

Deletion of Smad4 reduces hepatic inflammation and fibrogenesis during nonalcoholic steatohepatitis progression.

OBJECTIVE: To explore the effects of mothers against decapentaplegic homolog family member 4 (Smad4) deletion on inflammation and fibrogenesis in nonalcoholic steatohepatitis (NASH). METHODS: Biopsied liver samples from NASH patients and normal liver tissue samples from patients who had received liver resection for trauma were collected. Smad4Co/Co and wild-type (WT) mice were used to construct the NASH model using a high-fat diet (HFD) or methionine- and choline-deficient diet (MCD). HE staining and TUNEL assay were used to observe the pathological changes and cell apoptosis, respectively. Quantitative real-time polymerase chain reaction was used to detect the expression of inflammatory, fibrogenesis and apoptosis-related genes, and immunohistochemistry to determine the protein expression of SMAD4, MCP-1 and α-SMA. RESULTS: SMAD4 protein expression significantly increased in NASH patients than in the control group. Compared with WT mice, HFD- and MCD-fed Smad4Co/Co mice showed decreased hepatic steatosis, inflammation, liver cell apoptosis and nonalcoholic fatty liver activity score, reduced plasma glucose, triglyceride, free fatty acids, alanine aminotransferase and aspartate aminotransferase levels but increased adiponectin. Moreover, Smad4Co/Co decreased the expression of inflammatory markers (TNF-α, MCP-1, IFN-γ), fibrogenetic markers (COL1A1, α-SMA and TGF-ß1), lipogenic (Srebp1c, Fas and Acc) and proapoptotic genes (Bax and caspase-3), but increased the expression of ß-oxidation (Ppar-α, Cpt1 and Aco) and antiapoptotic genes (Bcl-2). CONCLUSION: Smad4 deletion may inhibit lipogenesis, stimulate ß-oxidation, improve lipid metabolism and liver function, alleviate inflammation and fibrosis, and reduce cell apoptosis in NASH.

Smad4/Fascin index is highly prognostic in patients with diffuse type EBV-associated gastric cancer.

Gastric cancer is a heterogeneous disorder for which predicting clinical outcomes is challenging, although various biomarkers have been suggested. The Smad4 and Fascin proteins are known prognostic indicators of different types of malignancy. Smad4 primarily functions as a key regulator of tumor suppression, whereas Fascin exhibits oncogenic function by enhancing tumor infiltration. A combined marker based on these opposing roles may improve prognostic accuracy in gastric cancer. Smad4 and Fascin expression was assessed in tissue microarrays obtained from 285 primary gastric adenocarcinoma, 201 normal tissue, and 51 metastatic adenocarcinoma samples. A Smad4/Fascin index based on the relative expression of each protein was divided into low- and high-expression groups using receiver operating characteristic curves. We compared normal tissue, primary adenocarcinoma, and metastatic adenocarcinoma in Smad4 and Fascin expression and the differences in clinicopathological findings between low Smad4/Fascin and high Smad4/Fascin expression in gastric adenocarcinoma. High Smad4/Fascin expression was significantly associated with worse outcomes, such as old age, advanced T and N category, large tumor size, high histological grade, lymphatic and vascular invasion, and presence of Epstein-Barr virus (EBV) (all p < 0.05). Univariate and multivariate analyses revealed a significant relationship between disease-free or overall survival and Smad4/Fascin index in diffuse-type or EBV-associated gastric cancer (all p < 0.05). A dual marker system using Smad4 and Fascin may be a reliable indicator for predicting clinical outcomes in patients with diffuse-type or EBV-associated gastric cancer.

Expression Pattern of Smad4/GATA3 as a Predictor of Survival in Invasive Ductal Carcinoma of the Breast.

BACKGROUND: Smad4 and GATA3 proteins are known prognostic markers in various cancers. Smad4 is a mediator linked to both tumour suppression and progression. GATA3 is a regulator of development and morphogenesis of the mammary gland. We assessed and compared the predictive performance of Smad4 and GATA3 for clinical outcomes in patients with breast cancer. METHODS: The combined expression pattern based on Smad4+/- and GATA3+/- was evaluated by immunostaining using breast cancer tissue microarray, and the relationships between protein expression and clinicopathological variables were analysed. RESULTS: Smad4 expression was only associated with an ill-defined tumour border, whereas GATA3 was associated with several good prognostic factors. On analysis of combined markers, there was a significant difference in the expression of fascin (an important factor for cancer invasiveness) between the Smad4+/GATA3- and Smad4-/GATA3+ groups. Smad4+/GATA3- was correlated with worse clinicopathological parameters, relapse-free survival (RFS), and overall survival (OS), compared to Smad4-/GATA3+. CONCLUSION: Combined markers of Smad4/GATA3 showed a superior performance compared to single markers for predicting RFS and OS in patients with breast cancer.

Correlations between the expressions of Smad4, estrogen receptor and the clinicopathological features of breast cancer / 国际肿瘤学杂志

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.

TGF-beta alterations in oral squamous cell carcinoma: narrative review / Alteraciones de TGF-beta en el carcinoma oral de células escamosas: revisión narrativa

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.

JP-HHT phenotype in Danish patients with SMAD4 mutations.

Patients with germline mutations in SMAD4 can present symptoms of both juvenile polyposis syndrome (JPS) and hereditary hemorrhagic telangiectasia (HHT): the JP-HHT syndrome. The complete phenotypic picture of this syndrome is only just emerging. We describe the clinical characteristics of 14 patients with SMAD4-mutations. The study was a retrospective, register-based study. SMAD4 mutations carriers were identified through the Danish HHT-registry, the genetic laboratories - and the genetic departments in Denmark. The medical files from relevant departments were reviewed and symptoms of HHT, JPS, aortopathy and family history were noted. We detected 14 patients with SMAD4 mutations. All patients had polyps removed and 11 of 14 fulfilled the diagnostic criteria for JPS. Eight patients were screened for HHT-symptoms and seven of these fulfilled the Curaçao criteria. One patient had aortic root dilation. Our findings support that SMAD4 mutations carriers have symptoms of both HHT and JPS and that the frequency of PAVM and gastric involvement with polyps is higher than in patients with HHT or JPS not caused by a SMAD4 mutation. Out of eight patients screened for aortopathy, one had aortic root dilatation, highlighting the need for additional screening for aortopathy.

Smad4 Deficiency in Smooth Muscle Cells Initiates the Formation of Aortic Aneurysm.

RATIONALE: Aortic aneurysm is a life-threatening cardiovascular disorder caused by the predisposition for dissection and rupture. Genetic studies have proved the involvement of the transforming growth factor-ß (TGF-ß) pathway in aortic aneurysm. Smad4 is the central mediator of the canonical TGF-ß signaling pathway. However, the exact role of Smad4 in smooth muscle cells (SMCs) leading to the pathogenesis of aortic aneurysms is largely unknown. OBJECTIVE: To determine the role of smooth muscle Smad4 in the pathogenesis of aortic aneurysms. METHODS AND RESULTS: Conditional gene knockout strategy combined with histology and expression analysis showed that Smad4 or TGF-ß receptor type II deficiency in SMCs led to the occurrence of aortic aneurysms along with an upregulation of cathepsin S and matrix metallopeptidase-12, which are proteases essential for elastin degradation. We further demonstrated a previously unknown downregulation of matrix metallopeptidase-12 by TGF-ß in the aortic SMCs, which is largely abrogated in the absence of Smad4. Chemotactic assay and pharmacologic treatment demonstrated that Smad4-deficient SMCs directly triggered aortic wall inflammation via the excessive production of chemokines to recruit macrophages. Monocyte/macrophage depletion or blocking selective chemokine axis largely abrogated the progression of aortic aneurysm caused by Smad4 deficiency in SMCs. CONCLUSIONS: The findings reveal that Smad4-dependent TGF-ß signaling in SMCs protects against aortic aneurysm formation and dissection. The data also suggest important implications for novel therapeutic strategies to limit the progression of the aneurysm resulting from TGF-ß signaling loss-of-function mutations.

Role of miR-146a in ultraviolet A-induced photoaging of human skin fibroblasts and its mechanism / 中华皮肤科杂志

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.

Compatibility of Chinese nourishing kidney herbs influences osteoblast activity and Smad4 mRNA expression / 中国组织工程研究

BACKGROUND:Chinese nourishing kidney herbs can prevent osteoporosis and improve bone metabolism, which has been proved in animal and cel experiments. But there are few reports on the compatibility of Chinese nourishing kidney herbs, and it is difficult to screen the optimal compatibility, as the interaction of active ingredients and drug substance basis are uncertain. OBJECTIVE: To determine the proliferation, differentiation and Smad4 mRNA expression of neonatal Sprague-Dawley rat osteoblasts cultured by Chinese nourishing kidney herbs with different compatibility so as to find out the optimal compatibility of Chinese nourishing kidney herbs. METHODS: Passage 5 osteoblasts were divided into five groups: group A, 1×10-5mol/L icarin; group B, 1×10-5mol/L icarin+1×10-5 mol/L naringin; group C, 1×10-5mol/L icarin+1×10-5 mol/L diosgenin; group D, 1×10-5mol/L icarin+ 1×10-5mol/L catalpol; group E, 10 μL normal saline (control group). There were six wels in each group. RESULTS AND CONCLUSION: Compared with the group E, the proliferative ability of osteoblasts and expression of Smad4 mRNA were increased in the groups B and C; until the 72nd hour, the proliferative ability of osteoblasts in the group B reached the peak. At 48 hours of culture, the activity of alkaline phosphatase in groups B and C was higher than that in group E; at 72 hours of culture, the activity of alkaline phosphatase in groups B and D was higher than that in group E. These findings indicate that the compatibility of Chinese nourishing kidney herbs can influence the activity of osteoblasts, and icarin+naringin has the strongest effect.

The Anti-Tumor Effect and Mechanism of Curcumin in Pancreatic Cancer / 天津医药

Objective To investigate the anti-tumor effect and mechanism of curcumin in pancreatic cancer (PC). Methods Smad4 and Jab1 expressions were detected by immunohistochemistry in tumor tissues and pericarcinomatous tis?sue from 35 PC cases, and the correlation of Smad4 and Jab1 were analyzed based on the percentage of positive staining in?tissues from 21 random selected PC cases. The effect of curcumin on expressions of tumor suppressors p53, Smad4 and cell cycle inhibitor p27 were examined by Western Blotting after human pancreatic cancer cell line PANC-1 were divided into PANC-1 control group (no treatments were given) and PANC-1 curcumin group (treated with cell culture medium containing 10μmol/L curcumin). The effect of curcumin on expressions of combination of β-TrCP1 and Smad4 was examined by Co-Immunoprecipitation after human embryonic kidney cell line 293T were divided into 293T control group (no treatments were given), 293T curcumin group (treated with cell culture medium containing 10μmol/L curcumin) and 293T Jab1 group (trans?fected by HA-Jab1 plasmid). Results Compared with expressions in pericarcinomatous tissues, Smad4 was down regulated while the expression of Jab1 was upregulated in PC tissues (P<0.01), and the expression of Smad4 was negatively correlated with the expression of Jab1 (n=21, r=-0.71, P=0.007). After treated with curcumin, the protein expression of p53, Smad4 and p27 was increased in PANC1 cell, and the protein expression of the combination ofβ-TrCP1 and Smad4 was decreased in 293T cell (P<0.05). After transfected by HA-Jab1 plasmid, the protein expression of the combination ofβ-TrCP1 and Smad4 was increased in 293T cell (P<0.05). Conclusion Curcumin may have suppression effect of PC through increasing the protein expression of p53, Smad4 and p27, and the mechanism of Smad4 upregulation may be related with the inhibition of Smad4 ubiquitination process, while Jab1 may be also involved in Smad4 degradation through ubiquitination.

NLK negatively regulate TGFβsignaling pathway via Smad4 / 重庆医学

Objective To study the effect of NLK on TGFβsignaling pathway and explore the molecular mechanism .Methods Protein stability assay was used to determine the influence of NLK on the degradation of Smad 4 .In vivo ubiquitination assay was applied to detect the effect of NLK on the ubiquitination of Smad4 .Luciferase reporter gene assay was used to detect the effect of NLK on CAGA‐luc and 3TP‐luc ,the responsive reporter of TGFβ signaling pathway .Real time PCR was applied to examine the effect of NLK on the expression of p21 and PAI‐1 ,the target genes of TGFβsignaling pathway .Results In HEK293T cell ,over ex‐pression of NLK promotes the degradation and ubiquitination of Smad4 .In HEK293T cells ,Ectopic expression of NLK inhibits the activity of CAGA luc and 3TP luc stimulated by TGFβ.In HepG2 cells ,over expression of NLK inhibits the expression of p21 and PAI 1 ,the target genes of TGFβsignaling pathway .Conclusion NLK promotes the ubiquitination and degradation of Smad4 ,conse‐quently inhibits TGFβsignaling pathway .

The expression and significance of Smad4 and Smad7 in newborn rats with hyperoxia-induced chronic lung diseases / 中国小儿急救医学

Objective To investigate the expression and significance of Smad4 and Smad7 in newborn rats with hyperoxia-induced chronic lung disease(CLD).Methods Sixty-four newborn Wistar rats 12 h after birth were divided into high-oxygen group (n =32) and air group (n =32,control group) by random number table method.The high-oxygen group was placed in the oxygen glass tank with continuous infusion of oxygen.And 1,3,7,14 d after experiment,tracheal separated,the chest opened to expose heart and lung,slices were Masson staining,undergo dynamic observation of the pulmonary pathological changes under light microscope.Lung fibrosis score was carried out to determine the degree of pulmonary fibrosis,and immunohistochemical technique was used to detect Smad4 and Smad7 protein expression in lung tissue.The expression levels of Smad4 and Smad7 protein in lung tissue were detected with Western blot.Results Compared with the air group,there was statistically significant difference in pulmonary fibrosis score on day 7 (2.67 ± 0.21 vs 0.58 ± 0.17) and day 14 (4.48 ± 0.24 vs 0.63 ± 0.13) in high-oxygen group (P ＜ 0.05) ; Smad4 and Smad7 was main in visible lung epithelial cells and interstitial fibroblasts.Smad4 expression in the high-oxygen group gradually enhanced,compared with the air group (P ＜ 0.05) on day 7 (122.35 ± 10.3 vs 140.08 ±7.77) and day 14(129.7 ± 7.33 vs 144.99 ± 6.49).Smad7 expression in the high-oxygen group first increased and then decreased,expression in the high-oxygen group increased on day 7 (122.35 ± 10.29 vs 130.56 ±9.8),and compared decreased with the air group(P ＜0.05) on day 14(132.16 ±4.38 vs 126.22 ±6.49).Conclusion The newborn rat exposed hyperoxia,the up-regulation of Smad4 protein expression and the down-regulation of Smad7 protein expression are imposible closely related to the happen and development of CLD pulmonary fibrosis.

Mesenchymal Smad4 mediated signaling is essential for palate development

INTRODUCTION: A cleft palate is a common birth defect in humans with an incidence of 1/500 to 1/1,000 births. It appears to be caused by multiple genetic and environmental factors during palatogenesis. Many molecules are involved in palate formation but the biological mechanisms underlying the normal palate formation and cleft palate are unclear. Accumulating evidence suggests that transforming growth factor beta/bone morphogenetic proteins (TGF-beta/BMP) family members mediate the epithelial-mesenchymal interactions during palate formation. However, their roles in palatal morphogenesis are not completely understood. MATERIALS AND METHODS: To understand the roles of TGF-beta/BMP signaling in vivo during palatogenesis, mice with a palatal mesenchyme-specific deletion of Smad4, a key intracellular mediator of TGF-beta/BMP signaling, were generated and analyzed using the Osr2Ires-Cre mice. RESULTS: The mutant mice were alive at the time of birth with open eyelids and complete cleft palate but died within 24 hours after birth. In skeletal preparation, the horizontal processes of the palatine bones in mutants were not formed and resulted in a complete cleft palate. At E13.5, the palatal shelves of the mutants were growing as normally as those of theirwild type littermates. However, the palatal shelves of the mutants were not elevated at E14.5 in contrast to the elevated palatal shelves of the wild type mice. At E15.5, the palatal shelves of the mutants were elevated over the tongue but did not come in contact with each other, resulting in a cleft palate. CONCLUSION: These results suggest that mesenchymal Smad4 mediated signaling is essential for the growth of palatal processes and suggests that TGF-beta/BMP family members are essential regulators during palate development.