The mitotic checkpoint is the major cell cycle checkpoint acting during mitosis to prevent aneuploidy and chromosomal instability, which are hallmarks of tumor cells. Reduced expression of the mitotic checkpoint component Mad1 causes aneuploidy and promotes tumors in mice [Iwanaga Y, et al. (2007) Cancer Res 67:160-166]. However, the prevalence and consequences of Mad1 overexpression are currently unclear. Here we show that Mad1 is frequently overexpressed in human cancers and that Mad1 up-regulation is a marker of poor prognosis. Overexpression of Mad1 causes aneuploidy and chromosomal instability through weakening mitotic checkpoint signaling caused by mislocalization of the Mad1 binding partner Mad2. Cells overexpressing Mad1 are resistant to microtubule poisons, including currently used chemotherapeutic agents. These results suggest that levels of Mad1 must be tightly regulated to prevent aneuploidy and transformation and that Mad1 up-regulation may promote tumors and cause resistance to current therapies.
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http://dx.doi.org/10.1073/pnas.1201911109 | DOI Listing |
EMBO Rep
January 2025
Department of Human Molecular Genetics and Biochemistry, Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel.
Spindle assembly checkpoint (SAC) inhibitors are a recently developed class of drugs, which perturb chromosome segregation during cell division, induce chromosomal instability (CIN), and eventually lead to cell death. The molecular features that determine cellular sensitivity to these drugs are not fully understood. We recently reported that aneuploid cancer cells are preferentially sensitive to SAC inhibition.
View Article and Find Full Text PDFSci Rep
January 2025
Biobank, Linyi People's Hospital, Linyi, 276003, China.
Low-grade glioma (LGG) is a primary, slow-growing brain tumor; however, its treatment and prognosis remain challenging. In this study, we analyzed cancer data from the TCGA database, focusing particularly on the expression of the CDKN3 gene in LGG. The results showed that high CDKN3 expression in LGG patients was significantly associated with poor survival outcomes.
View Article and Find Full Text PDFEur J Med Chem
January 2025
Department of Respiratory and Critical Care Medicine, Targeted Tracer Research and Development Laboratory, Institute of Respiratory Healthand, Department of Frontiers Science Center for Disease-related Molecular Network, Core Facilities, West China Hospital, Sichuan University, Chengdu, 610041, Sichuan, China. Electronic address:
NEK2, a serine/threonine protein kinase, is integral to mitotic events such as centrosome duplication and separation, microtubule stabilization, spindle assembly checkpoint, and kinetochore attachment. However, NEK2 overexpression leads to centrosome amplification and chromosomal instability, which are significantly associated with various malignancies, including liver, breast, and non-small cell lung cancer. This overexpression could facilitate tumor development and confer resistance to therapy by promoting aberrant cell division and centrosome amplification.
View Article and Find Full Text PDFImmun Inflamm Dis
January 2025
Second Department of Oncology, Guangdong Second Provincial General Hospital, Guangzhou, China.
Background: SET domain-containing protein 4 (SETD4) is a histone methyltransferase that has been shown to modulate cell proliferation, differentiation, and inflammatory responses by regulating histone H4 trimethylation (H4K20me3). Previous reports have demonstrated its function in the quiescence of cancer stem cells as well as drug resistance in several cancers. A limited number of systematic studies have examined SETD4's role in the tumor microenvironment, pathogenesis, prognosis, and therapeutic response.
View Article and Find Full Text PDFPLoS Genet
January 2025
Molecular Mycology Laboratory, Molecular Biology and Genetics Unit, Jawaharlal Nehru Centre for Advanced Scientific Research, Bengaluru, India.
During chromosome segregation, the spindle assembly checkpoint (SAC) detects errors in kinetochore-microtubule attachments. Timely activation and maintenance of the SAC until defects are corrected is essential for genome stability. Here, we show that shugoshin (Sgo1), a conserved tension-sensing protein, ensures the maintenance of SAC signals in response to unattached kinetochores during mitosis in a basidiomycete budding yeast Cryptococcus neoformans.
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