Structure of the human inner kinetochore CCAN complex and its significance for human centromere organization.

Centromeres are specialized chromosome loci that seed the kinetochore, a large protein complex that effects chromosome segregation. A 16-subunit complex, the constitutive centromere associated network (CCAN), connects between the specialized centromeric chromatin, marked by the histone H3 variant CENP-A, and the spindle-binding moiety of the kinetochore. Here, we report a cryo-electron microscopy structure of human CCAN. We highlight unique features such as the pseudo GTPase CENP-M and report how a crucial CENP-C motif binds the CENP-LN complex. The CCAN structure has implications for the mechanism of specific recognition of the CENP-A nucleosome. A model consistent with our structure depicts the CENP-C-bound nucleosome as connected to the CCAN through extended, flexible regions of CENP-C. An alternative model identifies both CENP-C and CENP-N as specificity determinants but requires CENP-N to bind CENP-A in a mode distinct from the classical nucleosome octamer.

Overexpression of CENPL mRNA potentially regulated by miR-340-3p predicts the prognosis of pancreatic cancer patients.

BACKGROUND: In our previous study it was found that CENPL was overexpressed in hepatocellular carcinoma and significantly predicted patient's prognosis. However, the expression and prognostic value of CENPL in other gastrointestinal tumors remain unknown. Therefore, we investigated the expression and prognostic value of CENPL in esophageal carcinoma (ESCA), stomach adenocarcinoma (STAD), pancreatic adenocarcinoma (PAAD), colon adenocarcinoma (COAD) and rectum adenocarcinoma (READ). METHODS: In this study, Oncomine, GEPIA, OncoLnc, TIMER, cBioPortal, miRWalk and ENCORI databases were used to analyze the level of CENPL mRNA, prognostic value and potential regulatory mechanism of CENPL mRNA in tumors. The CENPL expression and clinicopathological data regarding PAAD were from the UCSC Xena database and univariate and multivariate Cox regression analyses were performed using R (Version 3.6.3). Immunohistochemical staining was used to verify the expression of CENPL protein in clinical specimens. Cytoscape (Version: 3.7.2) was used to visualize microRNA (miRNA) that potentially regulates CENPL. RESULTS: Gene differential expression analysis showed that CENPL mRNA was significantly overexpressed in ESCA, STAD, PAAD, COAD and READ (p < 0.01). The overexpression of CENPL mRNA was significantly correlated with the poor prognosis of PAAD patients (p < 0.05). However, there was no significant correlation between the level of CENPL mRNA and the prognosis of ESCA, STAD, COAD and READ patients (p > 0.05). Univariate and multivariate Cox regression analyses suggested that CENPL was a prognostic risk factor for PAAD. The mutation rate of CENPL in PAAD was 2.2% (17/850). There was no significant correlation between the CENPL expression and the infiltration levels of immune cells in PAAD (|Cor|< 0.5). Immunohistochemical staining showed that CENPL was overexpressed in 42% (11/26) of PAAD specimens, which was significantly higher compared with that in the normal tissues. The expression of miR-340-3p and miR-484 in PAAD were significantly lower than in the normal tissues (p < 0.05) and PAAD patients with lower expression of miR-340-3p had poorer prognosis (p < 0.05). CONCLUSION: CENPL potentially regulated by miR-340-3p, is overexpressed in PAAD and predicts patient's prognosis, suggestive of a diagnostic and prognostic value in PAAD patients.

Nine year old boy with chromosome 1q23.3-q25.1 deletion.

Interstitial deletions of the long arm of chromosome 1 are rare, and recent reports of individuals with molecularly characterized deletions have resulted in advances in genotype-phenotype correlation. The recognizable phenotype associated with 1q23.3-q25.1 includes pre- and post-natal growth retardation, microcephaly, intellectual disability, delayed language acquisition, small hands and feet with brachydactyly and single palmar crease, and distinctive facial features including short bulbous nose, micrognathia, and ear malformations. We report a patient with an 11.35 Mb deletion from 1q23.3-q25.1 who has these features in addition to a rarely reported complication-profound sensorineural hearing loss. He has both pre- and post-natal growth deficiency and growth hormone deficiency that was diagnosed at age 2 years. However, unlike other individuals with this deletion and growth hormone deficiency, this boy has responded to treatment with human growth hormone. © 2016 Wiley Periodicals, Inc.

CENPL accelerates cell proliferation, cell cycle, apoptosis, and glycolysis via the MEK1/2-ERK1/2 pathway in hepatocellular carcinoma.

Centromere protein L (CENPL) is involved in the mitotic process of eukaryotic cells and the development of various types of cancer. However, its role in hepatocellular carcinoma (HCC) remains unclear. This study aimed to investigate the expression and clinical significance of CENPL in HCC, and explore its involvement in regulating HCC cell proliferation, apoptosis, cell cycle, and glycolysis both in vivo and in vitro. CENPL expression was analyzed in HCC and normal liver tissues using The Cancer Genome Atlas, Gene Expression Omnibus mining, real-time quantitative polymerase chain reaction, and immunohistochemistry. Functional assays were used to assess the role of CENPL in HCC cell proliferation, apoptosis, cell cycle, and glycolysis. The potential pathways underlying the regulatory effects of CENPL, as well as the expression of mitogen-activated protein kinase (MAPK) signaling pathway-related molecules and markers of proliferation and glycolysis were investigated. CENPL was significantly upregulated in HCC tissue and associated with multiple clinicopathological features and poor patient prognosis. Univariate and multivariate analyses demonstrated that CENPL may serve as an independent prognostic factor for HCC. Upregulation of CENPL in HCC regulated tumor proliferation and glycolytic processes. Mechanistic studies revealed that differentially expressed genes between the CENPL-overexpressing and control groups were mainly concentrated in the MAPK signaling pathway. Pathway inhibition analysis indicated that CENPL activated the MEK1/2-ERK1/2 signaling pathway to promote proliferation and glycolysis in HCC cells. This study elucidated the role of CENPL in regulating cell proliferation, apoptosis, cell cycle, and glycolysis in HCC. CENPL may represent a therapeutic target and prognostic biomarker for HCC.

E2F8-CENPL pathway contributes to homologous recombination repair and chemoresistance in breast cancer.

Chemoresistance poses a significant obstacle to the treatment of breast cancer patients. The increased capacity of DNA damage repair is one of the mechanisms underlying chemoresistance. Bioinformatic analyses showed that E2F8 was associated with cell cycle progression and homologous recombination (HR) repair of DNA double-strand breaks (DSBs) in breast cancer. E2F8 knockdown suppressed cell growth and attenuated HR repair. Accordingly, E2F8 knockdown sensitized cancer cells to Adriamycin and Cisplatin. Centromere protein L (CENPL) is a transcriptional target by E2F8. CENPL overexpression in E2F8-knockdowned cells recovered at least in part the effect of E2F8 on DNA damage repair and chemotherapy sensitivity. Consistently, CENPL knockdown impaired DNA damage repair and sensitized cancer cells to DNA-damaging drugs. These findings demonstrate that targeting E2F8-CENPL pathway is a potential approach to overcoming chemoresistance.

Delineation of the CENP-LN sub-complex dissociation mechanism upon multisite phosphorylation during mitosis.

Phosphorylation is the most prevalent form of regulation in cells, organizing virtually all cellular functions, including survival, motility, differentiation, proliferation, and metabolism. This regulatory function has been largely conserved from the primitive single-cell to the more complex multicellular organisms. More than a third of proteins in eukaryotes are phosphorylated, and essentially every class of protein undergoes regulation by phosphorylation. A decline in the cellular level of CENP-L and CENP-N (components of the constitutive centromere associated network) has earlier been reported and linked to cyclin-dependent kinase (CDK) phosphorylation upon transition into mitosis. Given the importance of posttranslational modifications in cell cycle regulation, mechanistic comprehension of the impact of phosphorylation on both proteins (CENP-L and CENP-N) is of high significance. Through the application of diverse computational analytical techniques, including atomistic molecular dynamics simulations, the mechanism of kinetochore mis-localization and dissociation of the CENP-LN sub-complex in mitosis was delineated. We showed that the phosphorylation of both components of the sub-complex induces global conformational destabilizing effects on the proteins, combined with changes in the electrostatic potential and increase in steric clashes around the protein-protein interaction interface. This, consistent with earlier experimental reports, suggest that the multisite phosphorylation of the CENP-LN sub-complex plays a crucial role in the regulation of cell division.Communicated by Ramaswamy H. Sarma.

Highly expressed CENPL is correlated with breast cancer cell proliferation and immune infiltration.

Background: Centromere protein L (CENPL) is associated with a variety of human diseases. However, its function in breast cancer remains uncertain. Methods: The Cancer Genome Atlas (TCGA) and genotype-tissue expression across cancer data were used to investigate CENPL expression. Using TCGA clinical survival data, the relationship between CENPL expression and patient prognosis was assessed. Using the cluster profiler R software tool, enrichment analysis of CENPL was carried out. Additionally, by studying the TCGA database, the relationship between CENPL expression and immune cell infiltration was assessed. To evaluate CENPL's impact on breast cancer cell proliferation, the CCK8 test and colony-formation assay were carried out. Scratch testing and the transwell assay were used to evaluate the effects of CENPL on breast cancer cell migration. Results: Breast cancer was one of numerous tumor forms with high CENPL expression. Significant relationships between high CENPL expression and the cell cycle, nuclear division, organelle fission, and chromosome segregation were found. Further investigation revealed that minimal infiltration of CD8-positive T cells and natural killer (NK) cells and high levels of Tregs and macrophages were correlated with high levels of CENPL expression. CENPL expression was linked to more than half of the ICP genes. Breast cancer cells' ability to proliferate and migrate was decreased by CENPL knockdown. Conclusions: Our findings suggest that CENPL may be an oncogene in breast cancer and a predictor of efficacy of immunotherapy for breast cancer.

Pan-Cancer and Single-Cell Analysis Reveals CENPL as a Cancer Prognosis and Immune Infiltration-Related Biomarker.

Background: Centromere protein L (CENPL) is an important member of the centromere protein (CENP) family. However, the correlation between CENPL expression and cancer development and immune infiltration has rarely been studied. Here, we studied the role of CENPL in pan-cancer and further verified the results in lung adenocarcinoma (LUAD) through in vitro experiments. Methods: The CENPL expression level was studied with TIMER 2.0 and Oncomine databases. The potential value of CENPL as a diagnostic and prognostic biomarker in pan-cancer was evaluated with the TCGA database and GEPIA. The CENPL mutation character was analyzed using the cBioPortal database. The LinkedOmics and CancerSEA databases were used to carry out the function analysis of CENPL. The role of CENPL in immune infiltration was studied using the TIMER and TISIDB websites. Moreover, the expression of CENPL was detected through RT-qPCR and Western blotting. Immunohistochemistry was used to evaluate the infiltration level of CD8+ T cells. Cell proliferation was detected by EdU and CCK8. A flow cytometer was used to analyze the influence of CENPL in cell cycle and apoptosis. Results: CENPL was increased in most of the cancers. The upregulation and mutation of CENPL were associated with a poorer prognosis in many cancers. The results showed a significant positive correlation between CENPL and myeloid-derived suppressor cell (MDSC) infiltration and a negative correlation between CENPL and T-cell NK infiltration in most of the cancers. CENPL regulated cell proliferation and cell cycle, and was negatively correlated with the inflammation level of LUAD. The in vitro experiments suggested that CENPL was increased in LUAD tissue and cell lines. There was a negative correlation between CENPL expression and CD8+ T-cell infiltration. The knockdown of CENPL significantly suppressed the expression of CDK2 and CCNE2, and induced G0/G1 arrest and apoptosis of LUAD. Conclusions: CENPL may function as a potential biomarker and oncogene in pan-cancer, especially LUAD. Furthermore, CENPL was associated with immune cell infiltration in pan-cancer, providing a potential immune therapy target for tumor treatment.