Protein tyrosine phosphatase 1B (PTP1B) is a negative regulator of the insulin receptor signal transduction pathway. We investigated the effects of glucose on PTP1B transcription in the human hepatocyte cell line Huh7. Using a reporter gene assay, we found that D-glucose dose-dependently enhanced the PTP1B promoter activity. Real-time PCR demonstrated that D-glucose also increased PTP1B mRNA expression. Protein kinase C (PKC) inhibitors partially but significantly inhibited the transactivation by D-glucose. Mithramycin, a Sp1 inhibitor, completely abrogated this transactivation. The deletion of three possible Sp1 sites in the promoter region of PTP1B significantly reduced the basal promoter activity and transactivation by D-glucose. Sp1 activation by PKC is one of the key mechanisms in the regulation of several gene expressions. Our data suggested that glucose enhanced PTP1B transcription through Sp1 activation by PKC. Increased hepatic PTP1B expression may partly explain glucose toxicity in diabetes.
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http://dx.doi.org/10.1016/j.mce.2007.04.005 | DOI Listing |
Medicine (Baltimore)
January 2025
Department of Respiratory and Critical Care Medicine, Zhongshan City People's Hospital, Zhongshan, Guangdong Province, China.
Rationale: ROS proto-oncogene 1 (ROS1) fusion is a rare but important driver mutation in non-small cell lung cancer, which usually shows significant sensitivity to small molecule tyrosine kinase inhibitors. With the widespread application of next-generation sequencing (NGS), more fusions and co-mutations of ROS1 have been discovered. Non-muscle myosin heavy chain 9 (MYH9) is a rare fusion partner of ROS1 gene as reported.
View Article and Find Full Text PDFCell Rep
January 2025
MOE Key Laboratory of Biosystems Homeostasis & Protection, and Zhejiang Provincial Key Laboratory of Cancer Molecular Cell Biology, Life Sciences Institute, Zhejiang University, Hangzhou, Zhejiang 310058, China; Center for Life Sciences, Shaoxing Institute, Zhejiang University, Shaoxing, Zhejiang 321000, China; Cancer Center, Zhejiang University, Hangzhou, Zhejiang 310058, China; The Second Affiliated Hospital, Zhejiang University, Hangzhou, Zhejiang 310009, China. Electronic address:
Transforming growth factor β (TGF-β) is well known to play paradoxical roles in tumorigenesis as it has both growth-inhibitory and pro-metastatic effects. However, the underlying mechanisms of how TGF-β drives the opposing responses remain largely unknown. Here, we report that ERBB4, a member of the ERBB receptor tyrosine kinase family, specifically promotes TGF-β's metastatic response but not its anti-growth response.
View Article and Find Full Text PDFJAMA Netw Open
January 2025
Department of Medical and Surgical Sciences, University of Bologna, Bologna, Italy.
Importance: The D842V platelet-derived growth factor receptor α (PDGFRA) mutation identifies a molecular subgroup of gastrointestinal stromal tumors (GISTs), primarily resistant to standard tyrosine kinase inhibitors and with an overall more indolent behavior. Although functional imaging with 18F-fluorodeoxyglucose-labeled positron emission tomography ([18F]FDG-PET) plays a proven role in GISTs, especially in early assessment of tumor response, less is known about [18F]FDG uptake according to the GIST molecular subtypes.
Objective: To evaluate the degree of [18F]FDG uptake in PDGFRA-mutant GISTs and better define the role of functional imaging in this rare and peculiar subset of GISTs.
Vet Comp Oncol
January 2025
Laboratory of Comparative and Translational Oncology, Department of Veterinary Medicine, Faculty of Animal Science and Food Engineering, University of São Paulo, Pirassununga, São Paulo, Brazil.
Inflammatory mammary carcinoma (IMC) is the most aggressive variant of invasive mammary tumours in dogs and in women. Decorin is an extracellular matrix molecule whose expression can be reduced or absent in various human cancers, which is associated with a poor prognosis. E-cadherin is a cell adhesion protein whose expression is reduced in several neoplasms.
View Article and Find Full Text PDFMetabolites
January 2025
Institute of Translational Biomedicine, Saint Petersburg State University, 199034 Saint Petersburg, Russia.
Background/objectives: The neurometabolic function is controlled by a complex multi-level physiological system that includes neurochemical, hormonal, immunological, sensory, and metabolic components. Functional disorders of monoamine systems are often detected in clinical practice together with metabolic dysfunctions. An important part of the mentioned pathological conditions are associated with disturbances in protein metabolism, some of the most important biomarkers which are aminotransferases and transcription factors that regulate and direct the most important metabolic reactions.
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