BACKGROUND The invertebrate and vertebrate Smad proteins have recently been identified as important mediators of the responses to transforming growth factor beta (TGF-beta) and related factors. We have previously shown that Smad3 and Smad4 (the product of the tumor suppressor gene DPC 4) strongly synergize as mediators of TGF-beta signaling, and that inactive carboxy-terminally truncated mutant...

Smad4 plays a key role in TGF-beta (transforming growth factor beta)/Smad-mediated transcriptional responses. We show that Smad4 is sumoylated both in vivo and in vitro. Recent studies showed that sumoylation of Smad4 regulated its stability, but the effect of sumoylation on the intrinsic transcriptional activity of Smad4 was not defined. We show that overexpression of SUMO (small ubiquitin-rel...

Vascular endothelial growth factor (VEGF) plays an important role in many disease states, including ischemia, chronic and acute inflammation, and pathologies associated with angiogenesis such as tumors and wounds. A number of factors regulate VEGF promoter activity and VEGF expression such as four and a half LIM domains 1 (FHL1) and Smad4. FHL1 belongs to a family of LIM-only proteins that regu...

Oral leukoplakia (OL) is a common, potentially malignant disorder of the oral cavity. SMAD4 was initially identified as a tumor suppressor and central mediator of transforming growth factor (TGF)-β signaling. In this study, we aimed to determine the expression patterns of SMAD4 in OL, its relationship with the degree of inflammation, and its clinical implications as a biomarker for OL malignant...

The role of Smad4 in transforming growth factor B (TGFB)– mediated epithelial-mesenchymal transition (EMT), invasion, and metastasis was investigated using isogenically matched pancreatic cancer cell lines that differed only in expression of Smad4. Cells expressing Smad4 showed an enhanced TGFBmediated EMT as determined by increased expression of vimentin and decreased expression of B-catenin a...

Oral leukoplakia (OL) is the most common premalignancy in the oral cavity and can progress to oral squamous cell carcinoma (OSCC). SMAD4 is a tumor suppressor implicated in multiple cancer types including OSCC. To assess the role of SMAD4 in oral leukoplakia malignant transformation, the authors investigated SMAD4 expression patterns in OL and OSCC using a highly specific antibody and correlate...

PURPOSE The members of the Smad family play key rolesin regulating gene expression in the transforming growth factor (TGF)-beta1 signaling pathways. Activation of Smads causes their translocation from the cytoplasm to the nucleus, where they function as transcription factors. The present study analyzed the expression and clinicopathological significance of Smad4 and TGF-beta1 in squamous cell c...

UNLABELLED Loss of E-cadherin (CDH1), Smad4, and p53 has been shown to play an integral role in gastric, intestinal, and breast cancer formation. Compound conditional knockout mice for Smad4, p53, and E-cadherin were generated to define and compare the roles of these genes in gastric, intestinal, and breast cancer development by crossing with Pdx-1-Cre, Villin-Cre, and MMTV-Cre transgenic mice....

The tongue is a muscular organ and plays a crucial role in speech, deglutition and taste. Despite the important physiological functions of the tongue, little is known about the regulatory mechanisms of tongue muscle development. TGFβ family members play important roles in regulating myogenesis, but the functional significance of Smad-dependent TGFβ signaling in regulating tongue skeletal muscle...

BACKGROUND To examine the expression of SMAD4 at gene and protein levels in glioma samples with different WHO grades and its association with survival. METHODS Two hundreds fifty-two glioma specimens and 42 normal control tissues were collected. Immunochemistry assay, quantitative real-time PCR and Western blot analysis were carried out to investigate the expression of SMAD4. Kaplan-Meier met...