Malignant rhabdoid tumors (MRT) are extremely aggressive pediatric tumors caused by the inactivation of the hSNF5/INI1 tumor suppressor gene, which encodes a core member of the SWI/SNF chromatin remodeling complex. Roles for hSNF5/INI1 in cell cycle and differentiation have been documented. Based on the observation that MRTs are highly invasive, we investigated a role for hSNF5/INI1 in cell migration. MRT cell lines exhibit high migration properties that are dramatically reduced upon hSNF5/INI1 expression. This effect is associated with the disorganization of the actin stress fiber network and is mediated by the inhibition of the activity of the small GTPase RhoA, through a nuclear, SWI/SNF-dependent transcriptional mechanism. We further show that the knockdown of hSNF5/INI1 in epithelial 293T or MCF7 cells results in increased cell size, loss of cell-cell adhesions, and enhanced migration, associated with an increased RhoA activity. Finally, we show that the SNF5 homology domain is required for hSNF5/INI1-mediated inhibition of migration, and that a missense mutation (S284L) associated with cancer is sufficient to impair hSNF5/INI1 function in migration. We conclude that the inhibition of migration is another crucial tumor suppressor function of hSNF5/INI1, in addition to its previously described functions in proliferation and differentiation, and that its loss-of-function in MRTs may account for the high invasiveness and metastatic potential of these tumors.
Download full-text PDF |
Source |
---|---|
http://dx.doi.org/10.1158/0008-5472.CAN-08-0115 | DOI Listing |
Mol Cancer
January 2025
Department of Radiation Oncology, Peking University Third Hospital, Beijing, 100191, China.
Background: Sorafenib, an FDA-approved drug for advanced hepatocellular carcinoma (HCC), faces resistance issues, partly due to myeloid-derived suppressor cells (MDSCs) that enhance immunosuppression in the tumor microenvironment (TME).
Methods: Various murine HCC cell lines and MDSCs were used in a series of in vitro and in vivo experiments. These included subcutaneous tumor models, cell viability assays, flow cytometry, immunohistochemistry, and RNA sequencing.
Chirurgie (Heidelb)
January 2025
Universitätsklinik für Plastische, Rekonstruktive und Ästhetische Chirurgie, Medizinische Universität Wien, Wien, Österreich.
Neurofibromatosis type 1 (NF1, formerly Recklinghausen's disease) is a genetic tumor predisposition syndrome in which the mutation of a tumor suppressor gene (neurofibromin) leads to the development of mostly benign neurofibromas of the skin and the central and peripheral nervous systems and malformations or tumors of other organ systems. Patients with NF1 should receive lifelong interdisciplinary care in specialized centers and important treatment decisions should be made by a regularly meeting interdisciplinary panel of experts. Plastic surgery plays an important role in the multidisciplinary management of all clinical forms of NF1-associated peripheral nerve sheath tumors, from cutaneous and subcutaneous to deep nodular and diffuse plexiform neurofibromas.
View Article and Find Full Text PDFEMBO J
January 2025
Department of Geriatrics, Gerontology Institute of Anhui Province, Centre for Leading Medicine and Advanced Technologies of IHM, The First Affiliated Hospital of USTC, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei, Anhui, China.
mTOR plays a pivotal role in cancer growth control upon amino acid response. Recently, CDK inhibitor P27KIP1 has been reported as a noncanonical inhibitor of mTOR signaling in MEFs, via unclear mechanisms. Here, we find that P27KIP1 degradation via E3 ligase TRIM21 is inhibited by human micropeptide hSPAR through its C-terminus (hSPAR-C), causing P27KIP1's cytoplasmic accumulation in breast cancer cells.
View Article and Find Full Text PDFCell Death Differ
January 2025
Department of Colorectal and Anal Surgery, Xinhua Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, 200092, China.
Hyperactivation of the YAP/TEAD transcriptional complex in cancers facilitates the development of an immunosuppressive tumor microenvironment. Herein, we observed that the transcription factor SP1 physically interacts with and stabilizes the YAP/TEAD complex at regulatory genomic loci in colorectal cancer (CRC). In response to serum stimulation, PKCζ (protein kinase C ζ) was found to phosphorylate SP1 and enhance its interaction with TEAD4.
View Article and Find Full Text PDFCurr Opin Pharmacol
January 2025
Functional Genomics and Metabolism Research Unit, Department of Biochemistry and Molecular Biology, University of Southern Denmark, Campusvej 55, DK-5230, Odense, Denmark. Electronic address:
Chromatin dynamics, involving reversible changes in chromatin structure, shape key cellular processes and genomic integrity during development and proliferation, with disruptions leading to cancer. Histones, core components of chromatin and substrates for chromatin-modifying enzymes, play crucial roles in oncogenesis when misregulated or mutated. This is particularly pronounced in pediatric hind brain cancers, some of which are driven primarily by the oncohistone H3K27M and the recently identified oncohistone-mimic protein CXorf67/EZHIP.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!