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Colorectal cancer (CRC) is a prevalent malignancy with a high mortality rate, primarily due to liver metastasis. This study explores the role of centromere protein N (CENP-N) in mediating the methylation of septin 9 (SEPT9) and its subsequent effects on aerobic glycolysis and liver metastasis in CRC. We employed in vitro and in vivo experiments, including single-cell RNA sequencing, methylation-specific PCR (MSP), ChIP assays, and various functional assays to assess the impact of CENP-N and SEPT9 on CRC cell proliferation, migration, invasion, and metabolic reprogramming. Our data reveal that CENP-N directly interacts with SEPT9, enhancing its methylation at specific lysine residues. This modification significantly upregulates key glycolytic enzymes, thereby promoting aerobic glycolysis, CRC cell proliferation, and migration. In vivo studies further demonstrate that the CENP-N/SEPT9 axis facilitates liver metastasis of CRC, as confirmed by fluorescence imaging and histological analysis. This study identifies a novel pathway where CENP-N-mediated methylation of SEPT9 drives metabolic reprogramming and metastasis in CRC. These findings suggest potential therapeutic targets for inhibiting CRC progression and liver metastasis, offering new insights into CRC pathogenesis. [ABSTRACT FROM AUTHOR]

In mitosis, accurate chromosome segregation depends on the kinetochore, a supermolecular machinery that couples dynamic spindle microtubules to centromeric chromatin. However, the structure–activity relationship of the constitutive centromere-associated network (CCAN) during mitosis remains uncharacterized. Building on our recent cryo-electron microscopic analyses of human CCAN structure, we investigated how dynamic phosphorylation of human CENP-N regulates accurate chromosome segregation. Our mass spectrometric analyses revealed mitotic phosphorylation of CENP-N by CDK1, which modulates the CENP-L–CENP-N interaction for accurate chromosome segregation and CCAN organization. Perturbation of CENP-N phosphorylation is shown to prevent proper chromosome alignment and activate the spindle assembly checkpoint. These analyses provide mechanistic insight into a previously undefined link between the centromere–kinetochore network and accurate chromosome segregation. [ABSTRACT FROM AUTHOR]

Background: Centromere protein N (CENP-N) has been reported to be highly expressed in malignancies, but its role and mechanism in nasopharyngeal carcinoma (NPC) are unknown. Methods: Abnormal CENP-N expression from NPC microarrays of GEO database was analyzed. CENP-N expression level was confirmed in NPC tissues and cell lines. Stable CENP-N knockdown and overexpression NPC cell lines were established, and transcriptome sequencing after CENP-N knockdown was performed. In vitro and in vivo experiments were performed to test the impact of CENP-N knockdown in NPC cells. ChIP and dual luciferase reporter assays were used to verify the combination of IRF2 and CENP-N. Western blot analysis, cellular immunofluorescence, immunoprecipitation and GST pulldown assays were used to verify the combination of CENP-N and AKT. Results: CENP-N was confirmed to be aberrantly highly expressed in NPC tissues and cell lines and to be associated with high 18F-FDG uptake in cancer nests and poor patient prognosis. Transcriptome sequencing after CENP-N knockdown revealed that genes with altered expression were enriched in pathways related to glucose metabolism, cell cycle regulation. CENP-N knockdown inhibited glucose metabolism, cell proliferation, cell cycling and promoted apoptosis. IRF2 is a transcription factor for CENP-N and directly promotes CENP-N expression in NPC cells. CENP-N affects the glucose metabolism, proliferation, cell cycling and apoptosis of NPC cells in vitro and in vivo through the AKT pathway. CENP-N formed a complex with AKT in NPC cells. Both an AKT inhibitor (MK-2206) and a LDHA inhibitor (GSK2837808A) blocked the effect of CENP-N overexpression on NPC cells by promoting aerobic glycolysis, proliferation, cell cycling and apoptosis resistance. Conclusions: The IRF2/CENP-N/AKT axis promotes malignant biological behaviors in NPC cells by increasing aerobic glycolysis, and the IRF2/CENP-N/AKT signaling axis is expected to be a new target for NPC therapy. [ABSTRACT FROM AUTHOR]

The centromere, in which kinetochore proteins are assembled, plays an important role in the accurate congression and segregation of chromosomes during cell mitosis. Although the function of the centromere and kinetochore is conserved from monocentric to holocentric, the DNA sequences of the centromere and components of the kinetochore are varied among different species. Given the lack of core centromere protein A (CENP-A) and CENP-C in the lepidopteran silkworm Bombyx mori, which possesses holocentric chromosomes, here we investigated the role of CENP-N, another important member of the centromere protein family essential for kinetochore assembly. For the first time, cellular localization and RNA interference against CENP-N have confirmed its kinetochore function in silkworms. To gain further insights into the regulation of CENP-N in the centromere, we analyzed the affinity-purified complex of CENP-N by mass spectrometry and identified 142 interacting proteins. Among these factors, we found that the chaperone protein heat shock cognate 70 (HSC70) is able to regulate the stability of CENP-N by prohibiting ubiquitin–proteasome pathway, indicating that HSC70 could control cell cycle-regulated degradation of CENP-N at centromeres. Altogether, the present work will provide a novel clue to understand the regulatory mechanism for the kinetochore activity of CENP-N during the cell cycle. [ABSTRACT FROM AUTHOR]

An abstract of the article "Dynamics of CENP-N kinetochore binding during the cell cycle," by Daniela Hellwig and colleagues is presented.