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Scientific Reports Dec 2022We previously reported that pentagamavunone-1 (PGV-1) effectively inhibited cell proliferation in many types of human tumors, including pancreatic cancer, by inducing M...
We previously reported that pentagamavunone-1 (PGV-1) effectively inhibited cell proliferation in many types of human tumors, including pancreatic cancer, by inducing M phase (prometaphase) arrest, senescence, and apoptosis with few side effects. However, a detailed evaluation of the effects of PGV-1 on pancreatic cancer cells in an in vivo setting has not yet been conducted. The present study investigated the potential efficacy of PGV-1 as both monotherapy and combination therapy for pancreatic cancer using multiple xenograft mouse assays. A cell-line derived xenograft model (CDX-M) with pancreatic cancer cell line and a patient-derived xenograft mouse model (PDX-M) using resected pancreatic cancer samples without neoadjuvant chemotherapy were established in both heterotopic and orthotopic manners. PGV-1 effectively suppressed tumor formation at the heterotopic and orthotopic sites in CDX-M than in untreated mice. Combination therapy with PGV-1 and gemcitabine more effectively suppressed tumor formation than monotherapy with PGV-1 or gemcitabine when administered after tumor formation. Monotherapy with PGV-1 or gemcitabine less effectively suppressed tumor formation in PDX-M than in CDX-M, whereas combination therapy with PGV-1 and gemcitabine more effectively suppressed tumor formation. PGV-1 as monotherapy and combination therapy with gemcitabine effectively inhibited tumor formation and has potential as an anticancer candidate for pancreatic cancer.
Topics: Humans; Mice; Animals; Deoxycytidine; Heterografts; Antineoplastic Combined Chemotherapy Protocols; Gemcitabine; Cell Proliferation; Apoptosis; Pancreatic Neoplasms; Xenograft Model Antitumor Assays; Cell Line, Tumor
PubMed: 36575213
DOI: 10.1038/s41598-022-26863-y -
Nature Communications Dec 2022Chromosome segregation is initiated by cohesin degradation, which is driven by anaphase-promoting complex/cyclosome (APC/C). Chromosome cohesin is removed by activated...
Chromosome segregation is initiated by cohesin degradation, which is driven by anaphase-promoting complex/cyclosome (APC/C). Chromosome cohesin is removed by activated separase, with the degradation of securin and cyclinB1. Dynamin-related protein 1 (DRP1), a component of the mitochondrial fission machinery, is related to cyclin dynamics in mitosis progression. Here, we show that DRP1 is recruited to the kinetochore by centromeric Centromere protein F (CENP-F) after nuclear envelope breakdown in mouse oocytes. Loss of DRP1 during prometaphase leads to premature cohesin degradation and chromosome segregation. Importantly, acute DRP1 depletion activates separase by initiating cyclinB1 and securin degradation during the metaphase-to-anaphase transition. Finally, we demonstrate that DRP1 is bound to APC2 to restrain the E3 ligase activity of APC/C. In conclusion, DRP1 is a CENP-F-dependent atypical spindle assembly checkpoint (SAC) protein that modulates metaphase-to-anaphase transition by controlling APC/C activity during meiosis I in oocytes.
Topics: Animals; Mice; Anaphase-Promoting Complex-Cyclosome; Cell Cycle Proteins; Chromosome Segregation; Dynamins; Kinetochores; Meiosis; Oocytes; Securin; Separase
PubMed: 36513638
DOI: 10.1038/s41467-022-35461-5 -
Current Oncology (Toronto, Ont.) Nov 2022Kruppel-associated box (KRAB) proteins reportedly play a dual role in neoplastic transformation. At present, little is known about the function of the proteins encoded...
OBJECTIVE
Kruppel-associated box (KRAB) proteins reportedly play a dual role in neoplastic transformation. At present, little is known about the function of the proteins encoded by the human pogo transposable element derived with KRAB domain (POGK) gene. Herein, we evaluated the prognostic significance of POGK expression in patients with hepatocellular carcinoma (HCC).
METHODS
The data of HCC patients was downloaded from The Cancer Genome Atlas (TCGA) database. To determine the relationship between POGK and clinical features, logistic regression was applied. Cox regression and Kaplan-Meier analyses were used to evaluate the correlation between POGK and survival rates. Gene ontology (GO) analysis and Gene set enrichment analysis (GSEA) were conducted to identify the enriched pathways and functions associated with POGK.
RESULTS
A total of 374 HCC patients were identified in TCGA. POGK was significantly upregulated in HCC and correlated with tumor status ( = 0.036), race ( = 0.025), weight ( = 0.002), body mass index ( = 0.033), histologic grade ( < 0.001), and alpha-fetoprotein ( < 0.001). High POGK expression in HCC patients correlated with a poor outcome in terms of overall survival ( = 0.0018), progression-free survival ( = 0.0087), relapse-free survival ( = 0.045), and disease-specific survival ( = 0.014), according to Kaplan-Meier analysis. Receiver operating characteristic curve analysis showed that the area under the curve of POGK expression for HCC diagnosis was 0.891. GSEA showed that high POGK expression might activate mitotic prometaphase, kinesins, homologous DNA pairing and strand exchange, MET activates PTK2 signaling pathway, G1 to S cell cycle control, Aurora B pathway, ncRNAs involved in WNT signaling pathway, hepatitis C, and ncRNAs involved in the STAT3 signaling pathway. POGK expression correlated with the abundance of adaptive and innate immunocytes in HCC.
CONCLUSION
High expression of POGK has high diagnostic and prognostic values in patients with HCC. Moreover, POGK expression is correlated with immune infiltration in HCC.
Topics: Humans; Carcinoma, Hepatocellular; Liver Neoplasms; Gene Expression Regulation, Neoplastic; Biomarkers, Tumor; Neoplasm Recurrence, Local; Prognosis
PubMed: 36421335
DOI: 10.3390/curroncol29110682 -
[Zhonghua Yan Ke Za Zhi] Chinese... Nov 2022A 53-year-old female patient complained of 1 week of bilateral visual blurring. She was previously diagnosed with metastatic melanoma of the inguinal lymph nodes and...
A 53-year-old female patient complained of 1 week of bilateral visual blurring. She was previously diagnosed with metastatic melanoma of the inguinal lymph nodes and treated with the oral targeted drug vemurafenib. She exhibited aqueous flare in the left eye, and her fundus examination revealed optic disc swelling in the left eye and bilateral serious detachment of the retinal neuroepithelial layer. Fluorescein angiography showed multiple pinpoint hyperfluorescence leakage spots in the prometaphase and appeared as multilobular dye pooling in the late phase. We diagnosed her as Vogt-Koyanagi-Harada syndrome and gave glucocorticoid treatment for eyes. Oral vemurafenib was also taken intermittently under the guidance of an oncologist. After treatment, her bilateral vision improved, the anterior segment inflammation disappeared, and the retinal neuroepithelial layer reattached, with presence of the "sunset glow" fundus.
Topics: Humans; Female; Middle Aged; Uveomeningoencephalitic Syndrome; Vemurafenib; Fluorescein Angiography; Melanoma; Fundus Oculi; Vision Disorders
PubMed: 36348532
DOI: 10.3760/cma.j.cn112142-20220215-00055 -
Nature Communications Nov 2022Human beings are made of ~50 trillion cells which arise from serial mitotic divisions of a single cell - the fertilised egg. Remarkably, the early human embryo is often...
Human beings are made of ~50 trillion cells which arise from serial mitotic divisions of a single cell - the fertilised egg. Remarkably, the early human embryo is often chromosomally abnormal, and many are mosaic, with the karyotype differing from one cell to another. Mosaicism presumably arises from chromosome segregation errors during the early mitotic divisions, although these events have never been visualised in living human embryos. Here, we establish live cell imaging of chromosome segregation using normally fertilised embryos from an egg-share-to-research programme, as well as embryos deselected during fertility treatment. We reveal that the first mitotic division has an extended prometaphase/metaphase and exhibits phenotypes that can cause nondisjunction. These included multipolar chromosome segregations and lagging chromosomes that lead to formation of micronuclei. Analysis of nuclear number and size provides evidence of equivalent phenotypes in 2-cell human embryos that gave rise to live births. Together this shows that errors in the first mitotic division can be tolerated in human embryos and uncovers cell biological events that contribute to preimplantation mosaicism.
Topics: Humans; Embryo, Mammalian; Chromosome Segregation; Mosaicism; Metaphase; Karyotype; Blastocyst; Aneuploidy
PubMed: 36347869
DOI: 10.1038/s41467-022-34294-6 -
The Journal of Pharmacy and Pharmacology Apr 2023Haploid germ cell-specific nuclear protein kinase (Haspin) is a serine/threonine kinase as an atypical kinase, which is structurally distinct from conventional protein... (Review)
Review
OBJECTIVES
Haploid germ cell-specific nuclear protein kinase (Haspin) is a serine/threonine kinase as an atypical kinase, which is structurally distinct from conventional protein kinases.
KEY FINDINGS
Functionally, Haspin is involved in important cell cycle progression, particularly in critical mitosis regulating centromeric sister chromatid cohesion during prophase and prometaphase, and subsequently ensuring proper chromosome alignment during metaphase and the normal chromosome segregation during anaphase. However, increasing evidence has demonstrated that Haspin is significantly upregulated in a variety of cancer cells in addition to normal proliferating somatic cells. Its knockdown or small molecule inhibition could prevent cancer cell growth and induce apoptosis by disrupting the regular mitotic progression. Given the specificity of its expressed tissues or cells and the uniqueness of its current known substrate, Haspin can be a promising target against cancer. Consequently, selective synthetic and natural inhibitors of Haspin have been widely developed to determine their inhibitory power for various cancer cells in vivo and in vitro.
SUMMARY
Here our perspective includes a comprehensive review of the roles and structure of Haspin, its relatively potent and selective inhibitors and Haspin's preliminary studies in a variety of cancers.
Topics: Humans; Antimitotic Agents; Phosphorylation; Intracellular Signaling Peptides and Proteins; Protein Serine-Threonine Kinases; Mitosis; Neoplasms
PubMed: 36334086
DOI: 10.1093/jpp/rgac080 -
Journal of Cell Science Mar 2023Mitotic cell division requires that kinetochores form microtubule attachments that can segregate chromosomes and control mitotic progression via the spindle assembly...
Mitotic cell division requires that kinetochores form microtubule attachments that can segregate chromosomes and control mitotic progression via the spindle assembly checkpoint. During prometaphase, kinetochores shed a domain called the fibrous corona as microtubule attachments form. This shedding is mediated, in part, by the minus-end directed motor dynein, which 'strips' cargoes along K-fibre microtubules. Despite its essentiality, little is known about how dynein stripping is regulated and how it responds to attachment maturation. Lis1 (also known as PAFAH1B1) is a conserved dynein regulator that is mutated in the neurodevelopmental disease lissencephaly. Here, we have combined loss-of-function studies, high-resolution imaging and separation-of-function mutants to define how Lis1 contributes to dynein-mediated corona stripping in HeLa cells. Cells depleted of Lis1 fail to disassemble the corona and show a delay in metaphase as a result of persistent checkpoint activation. Furthermore, we find that although kinetochore-tethered Lis1-dynein is required for error-free microtubule attachment, the contribution of Lis1 to corona disassembly can be mediated by a cytoplasmic pool. These findings support the idea that Lis1 drives dynein function at kinetochores to ensure corona disassembly and prevent chromosome mis-segregation.
Topics: Humans; Dyneins; HeLa Cells; Kinetochores; M Phase Cell Cycle Checkpoints; Microtubule-Associated Proteins; Microtubules; Mitosis; 1-Alkyl-2-acetylglycerophosphocholine Esterase
PubMed: 36274587
DOI: 10.1242/jcs.260226 -
Methods in Molecular Biology (Clifton,... 2022The cell cycle is a series of events leading to cell replication. When plated at low cell densities in serum-containing medium, cultured cells start to proliferate,...
The cell cycle is a series of events leading to cell replication. When plated at low cell densities in serum-containing medium, cultured cells start to proliferate, moving through the four phases of the cell cycle: G1, S, G2, and M. Mitosis is the most dynamic period of the cell cycle, involving a major reorganization of virtually all cell components. Mitosis is further divided into prophase, prometaphase, metaphase, anaphase, and telophase, which can be easily distinguished from one another by protein markers and/or comparing their chromosome morphology under fluorescence microscope. The progression of the cell cycle through these mitotic subphases is tightly regulated by complicated molecular mechanisms. Synchronization of cells to the mitotic subphases is important for understanding these molecular mechanisms. Here, we describe a protocol to synchronize Hela cells to prometaphase, metaphase, and anaphase/telophase. In this protocol, Hela cells are first synchronized to the early S phase by a double thymidine block. Following the release of the block, the cells are treated with nocodazole, MG132, and blebbistatin to arrest them at prometaphase, metaphase, and anaphase/telophase, respectively. Successful synchronization is assessed using Western blot and fluorescence microscopy.
Topics: Anaphase; HeLa Cells; Humans; Metaphase; Mitosis; Telophase
PubMed: 36045201
DOI: 10.1007/978-1-0716-2736-5_8 -
Methods in Molecular Biology (Clifton,... 2022The cell cycle is the series of events that take place in a cell that drives it to divide and produce two new daughter cells. Through more than 100 years of efforts by... (Review)
Review
The cell cycle is the series of events that take place in a cell that drives it to divide and produce two new daughter cells. Through more than 100 years of efforts by scientists, we now have a much clearer picture of cell cycle progression and its regulation. The typical cell cycle in eukaryotes is composed of the G1, S, G2, and M phases. The M phase is further divided into prophase, prometaphase, metaphase, anaphase, telophase, and cytokinesis. Cell cycle progression is mediated by cyclin-dependent kinases (Cdks) and their regulatory cyclin subunits. However, the driving force of cell cycle progression is growth factor-initiated signaling pathways that controls the activity of various Cdk-cyclin complexes. Most cellular events, including DNA duplication, gene transcription, protein translation, and post-translational modification of proteins, occur in a cell-cycle-dependent manner. To understand these cellular events and their underlying molecular mechanisms, it is desirable to have a population of cells that are traversing the cell cycle synchronously. This can be achieved through a process called cell synchronization. Many methods have been developed to synchronize cells to the various phases of the cell cycle. These methods could be classified into two groups: synchronization methods using chemical inhibitors and synchronization methods without using chemical inhibitors. All these methods have their own merits and shortcomings.
Topics: Anaphase; Cell Cycle; Cell Cycle Proteins; Cyclin-Dependent Kinases; Cyclins; Mitosis
PubMed: 36045194
DOI: 10.1007/978-1-0716-2736-5_1 -
ELife Aug 2022Btg3-associated nuclear protein (Banp) was originally identified as a nuclear matrix-associated region (MAR)-binding protein and it functions as a tumor suppressor. At...
Btg3-associated nuclear protein (Banp) was originally identified as a nuclear matrix-associated region (MAR)-binding protein and it functions as a tumor suppressor. At the molecular level, Banp regulates transcription of metabolic genes via a CGCG-containing motif called the Banp motif. However, its physiological roles in embryonic development are unknown. Here, we report that Banp is indispensable for the DNA damage response and chromosome segregation during mitosis. Zebrafish mutants show mitotic cell accumulation and apoptosis in developing retina. We found that DNA replication stress and tp53-dependent DNA damage responses were activated to induce apoptosis in mutants, suggesting that Banp is required for regulation of DNA replication and DNA damage repair. Furthermore, consistent with mitotic cell accumulation, chromosome segregation was not smoothly processed from prometaphase to anaphase in morphants, leading to a prolonged M-phase. Our RNA- and ATAC-sequencing identified 31 candidates for direct Banp target genes that carry the Banp motif. Interestingly, a DNA replication fork regulator, and two chromosome segregation regulators, and , are included in this list. Thus, Banp directly regulates transcription of for recovery from DNA replication stress, and and for chromosome segregation during mitosis. Our findings provide the first in vivo evidence that Banp is required for cell-cycle progression and cell survival by regulating DNA damage responses and chromosome segregation during mitosis.
Topics: Animals; Cell Cycle; Chromosome Segregation; Chromosomes; DNA Damage; Mitosis; Nuclear Proteins; Retina; Zebrafish
PubMed: 35942692
DOI: 10.7554/eLife.74611