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1.
Article in English | MEDLINE | ID: mdl-36945759

ABSTRACT

INTRODUCTION: Geminin, a (25 kDa) protein, was originally identified as a key regulator of DNA replication licensing in the cell cycle and of cell fate during embryonic nervous system formation. Although geminin is involved in mechanisms underlying the regulation of transcription and patterning in embryonic development, its expression and possible significance in human epidermal morphogenesis remains unknown. METHODS: Forty-one skin biopsy specimens obtained from human fetuses (10th to 23rd week of estimated gestational age) were processed for immunohistochemistry using a primary rabbit polyclonal antibody against geminin. RESULTS: Distinct and statistically significant qualitative and quantitative alterations in the spatiotemporal expression pattern of geminin were observed in the developing human epidermis. CONCLUSIONS: The highly ordered expression of geminin in different layers of fetal human epidermis reported here for the first time suggests that this protein may play a significant role in epidermal morphogenesis. However, the mechanisms underlying the alterations of the geminin expression pattern during fetal development at the molecular level remain to be elucidated. Further studies are now warranted to address whether the expression pattern of geminin in the developing human epidermis is disturbed in fetuses with genodermatoses and whether these disturbances might be important for prenatal diagnosis of genodermatoses.


Subject(s)
DNA Replication , Epidermis , Animals , Humans , Rabbits , Cell Cycle/physiology , Epidermis/metabolism , Geminin/metabolism , Morphogenesis
2.
Stem Cell Res ; 67: 103031, 2023 03.
Article in English | MEDLINE | ID: mdl-36702081

ABSTRACT

We previously generated a doxycycline-inducible H2B-mTurq2 reporter in hiPSCs to track cells and study cell division and apoptosis. To improve visualization of cycling cells, we introduced a ubiquitously transcribed mScarletI-Geminin (GMMN) (1-110) into the previously untargeted second AAVS1 allele. Fusion to the N-terminal part of GMNN provided tightly controlled mScarletI expression during the cell cycle. mScarletI fluorescence increased gradually from the S-phase through the M-phase of the cell cycle and was lost at the metaphase-anaphase transition. The resulting hiPSC reporter line generated, which we named ProLiving, is a valuable tool to study cell division and cell cycle characteristics in living hiPSC-derived cells.


Subject(s)
Induced Pluripotent Stem Cells , Geminin/genetics , Geminin/metabolism , Induced Pluripotent Stem Cells/metabolism , Cell Cycle , Cell Division , Cell Cycle Proteins/genetics
3.
Cell Rep ; 41(11): 111810, 2022 12 13.
Article in English | MEDLINE | ID: mdl-36516767

ABSTRACT

Multiciliated ependymal cells and adult neural stem cells are components of the adult neurogenic niche, essential for brain homeostasis. These cells share a common glial cell lineage regulated by the Geminin family members Geminin and GemC1/Mcidas. Ependymal precursors require GemC1/Mcidas expression to massively amplify centrioles and become multiciliated cells. Here, we show that GemC1-dependent differentiation is initiated in actively cycling radial glial cells, in which a DNA damage response, including DNA replication-associated damage and dysfunctional telomeres, is induced, without affecting cell survival. Genotoxic stress is not sufficient by itself to induce ependymal cell differentiation, although the absence of p53 or p21 in progenitors hinders differentiation by maintaining cell division. Activation of the p53-p21 pathway downstream of GemC1 leads to cell-cycle slowdown/arrest, which permits timely onset of ependymal cell differentiation in progenitor cells.


Subject(s)
Neural Stem Cells , Tumor Suppressor Protein p53 , Geminin/genetics , Geminin/metabolism , Tumor Suppressor Protein p53/metabolism , Ependyma/metabolism , Ependymoglial Cells/metabolism , Neural Stem Cells/metabolism , Cell Differentiation
4.
J Stomatol Oral Maxillofac Surg ; 123(6): e828-e832, 2022 11.
Article in English | MEDLINE | ID: mdl-35217222

ABSTRACT

OBJECTIVE: Uncontrolled proliferation and aberrations in cell-cycle progression are fundamental issues in cancer. In this study we aimed to determine and compare deoxyribonucleic acid (DNA) replication licensing factors at the mRNA and protein levels among squamous cell carcinomas (SCCs) of the lip, facial-skin and oral cavity. MATERIALS AND METHODS: A total of 103 lip, oral and face SCCs were immunohistochemically stained with MCM2 (mini-chromosome maintenance 2), geminin, and ki67, and their labeling-indices were calculated. Also, 57 SCCs from the same regions along with their adjacent normal tissues underwent quantitative reverse transcription-polymerase chain reaction analysis. RESULTS: All three proteins were overexpressed in the studied SCCs, but only geminin (P = 0.004) showed significant difference among the three regions, with higher levels in oral SCCs compared to lip (P = 0.005) and skin (P = 0.024) tumors. Geminin expression did not differ between skin- and lip-SCCs (P = 0.822). MCM2/ki67 ratio was higher in oral- compared to skin-neoplasms (P = 0.039), but no difference was found in geminin/ki67 among the SCC-subsites. There were significant differences in MCM2 and geminin mRNA between carcinomatous- and normal-tissues in all tumors, but not among the three locations. CONCLUSION: MCM2 and geminin are involved in the tumorigenesis of lip, face and oral SCC at both mRNA- and protein-levels. Geminin may have a role in the site-specific biologic behavior of SCC. Skin SCCs had the highest proportion of licensed non-proliferating cells, while actively proliferating cells were more prominent in oral tumors. Regarding DNA replication, lip SCCs seem to be closer to skin tumors compared to their oral counterparts.


Subject(s)
Carcinoma, Squamous Cell , Facial Neoplasms , Lip Neoplasms , Mouth Neoplasms , Humans , Carcinoma, Squamous Cell/genetics , Carcinoma, Squamous Cell/pathology , DNA Replication , Geminin/genetics , Geminin/metabolism , Immunohistochemistry , Ki-67 Antigen/genetics , Ki-67 Antigen/metabolism , Minichromosome Maintenance Complex Component 2/genetics , Minichromosome Maintenance Complex Component 2/metabolism , Mouth Neoplasms/genetics , Mouth Neoplasms/pathology , RNA, Messenger/genetics , Facial Neoplasms/genetics , Facial Neoplasms/metabolism , Lip Neoplasms/genetics , Lip Neoplasms/metabolism
5.
Braz J Otorhinolaryngol ; 88(4): 529-532, 2022.
Article in English | MEDLINE | ID: mdl-32972865

ABSTRACT

INTRODUCTION: Proliferation markers play a significant role in the biologic behavior of tumors. Geminin is a known inhibitor of the cell cycle and DNA replication and has not been previously reported in cutaneous basal and squamous cell carcinomas of the head and neck. OBJECTIVES: We aimed to investigate proliferation markers ki67, MCM2, and geminin in head and neck cutaneous basal and squamous cell carcinomas. METHODS: Forty cases of each tumor were immuostained with ki67, MCM2, and geminin followed by assessment of labeling indices (LIs). MCM2/ki67- and geminin/ki67-ratios were also determined; t-test was used for statistical analysis (p<0.05). RESULTS: There was no significant difference in ki67 (p=0.06) and MCM2 (p=0.46) between cutaneous basal and squamous cell carcinomas; however, geminin LI was significantly higher in squamous cell carcinomas compared to cutaneous basal cell carcinomas (p<0.001). Only geminin/ki67 showed a significant difference between the two tumors with the ratio showing significantly higher numbers in squamous cell carcinomas (p=0.015). CONCLUSIONS: Geminin could be regarded as an effective factor in the pathogenesis of head and neck cutaneous cutaneous basal cell carcinomas and squamous cell carcinomas and may be one of the responsible elements in the difference between the biologic behavior of these tumors.


Subject(s)
Carcinoma, Basal Cell , Carcinoma, Squamous Cell , Geminin , Head and Neck Neoplasms , Skin Neoplasms , Biomarkers, Tumor/analysis , Carcinoma, Basal Cell/pathology , Carcinoma, Squamous Cell/pathology , Geminin/metabolism , Head and Neck Neoplasms/pathology , Humans , Immunohistochemistry , Ki-67 Antigen/metabolism , Minichromosome Maintenance Complex Component 2/metabolism , Skin Neoplasms/pathology
6.
Cancer Gene Ther ; 29(3-4): 304-325, 2022 03.
Article in English | MEDLINE | ID: mdl-33723406

ABSTRACT

Triple-negative breast cancer (TNBCs) display lung metastasis tropism. However, the mechanisms underlying this organ-specific pattern remains to be elucidated. We sought to evaluate the utility of blocking extravasation to prevent lung metastasis. To identify potential geminin overexpression-controlled genetic drivers that promote TNBC tumor homing to lungs, we used the differential/suppression subtractive chain (D/SSC) technique. A geminin overexpression-induced lung metastasis gene signature consists of 24 genes was discovered. We validated overexpression of five of these genes (LGR5, HAS2, CDH11, NCAM2, and DSC2) in worsening lung metastasis-free survival in TNBC patients. Our data demonstrate that LGR5-induced ß-catenin signaling and stemness in TNBC cells are geminin-overexpression dependent. They also demonstrate for the first-time expression of RSPO2 in mouse lung tissue only and exacerbation of its secretion in the circulation of mice that develop geminin overexpressing/LGR5+-TNBC lung metastasis. We identified a novel extravasation receptor complex, consists of CDH11, CD44v6, c-Met, and AXL on geminin overexpressing/LGR5+-TNBC lung metastatic precursors, inhibition of any of its receptors prevented geminin overexpressing/LGR5+-TNBC lung metastasis. Overall, we propose that geminin overexpression in normal mammary epithelial (HME) cells promotes the generation of TNBC metastatic precursors that home specifically to lungs by upregulating LGR5 expression and promoting stemness, intravasation, and extravasation in these precursors. Circulating levels of RSPO2 and OPN can be diagnostic biomarkers to improve risk stratification of metastatic TNBC to lungs, as well as identifying patients who may benefit from therapy targeting geminin alone or in combination with any member of the newly discovered extravasation receptor complex to minimize TNBC lung metastasis.


Subject(s)
Lung Neoplasms , Triple Negative Breast Neoplasms , Animals , Breast/metabolism , Breast/pathology , Cell Line, Tumor , Desmocollins , Geminin/metabolism , Humans , Lung/pathology , Lung Neoplasms/diagnosis , Lung Neoplasms/genetics , Mice , Neural Cell Adhesion Molecules , Triple Negative Breast Neoplasms/metabolism
7.
Bioengineered ; 12(2): 11482-11489, 2021 12.
Article in English | MEDLINE | ID: mdl-34874226

ABSTRACT

Low-grade cervical squamous intraepithelial lesion is a precancerous neoplasia that has appreciable probability to evolve into malignancy. To explore the prognostic value of HPV 16/18 genotyping and geminin mRNA quantification in predicting the progressiveness of LSIL. We recruited 212 participants who were negative for intraepithelial lesion or malignancy (NILM 76), low-grade squamous intraepithelial lesion (LSIL 85), high-grade squamous intraepithelial lesion (HSIL 36) and cervical intraepithelial neoplasia grade cervical cancer grade 3, (CIN3 15) patients. Tissues were obtained during excisional treatment. HPV 16/18 genotyping and geminin mRNA qRT-PCR were performed. HPV 16/18 positivity rate and geminin mRNA level were integrated with the clinical parameters into a multivariate logistic model. Area under curve was yielded based on receiver operation curve derived from this multivariate logistic model. Follow-up visits were performed to LSIL patients with progression. HSIL patients have higher HPV 16/18 positivity rate and geminin mRNA levels than LSIL. Among HSIL, CIN3 have higher HPV 16/18 positivity rate and geminin mRNA levels. Multivariate logistic analysis showed that HPV 16/18 positivity and geminin mRNA expression status are independent factors for differentiating HSIL and LSIL. The baseline HPV 16/18 positivity rate and geminin mRNA levels of 18 LSIL patients who developed HSIL are significantly higher than non-progressive LSIL patients. The values examined at follow-up timepoints were also higher than baseline. These results suggest that geminin is implicated in the progression of LSIL and combining HPV 16/18 genotyping and geminin mRNA qRT-PCR could potentially differentiating the progressive LSIL and improve the efficacy of clinical intervention.


Subject(s)
Geminin/genetics , Human papillomavirus 16/genetics , Human papillomavirus 18/genetics , Squamous Intraepithelial Lesions/genetics , Uterine Cervical Dysplasia/genetics , Uterine Cervical Neoplasms/genetics , Adult , Aged , Cell Line, Tumor , Disease Progression , Female , Follow-Up Studies , Geminin/metabolism , Gene Expression Regulation, Neoplastic , Genotype , Humans , Logistic Models , Middle Aged , Multivariate Analysis , Prognosis , RNA, Messenger/genetics , ROC Curve , Squamous Intraepithelial Lesions/pathology , Uterine Cervical Neoplasms/pathology , Uterine Cervical Dysplasia/pathology
8.
Nat Commun ; 12(1): 5779, 2021 10 01.
Article in English | MEDLINE | ID: mdl-34599168

ABSTRACT

Geminin and its binding partner Cdt1 are essential for the regulation of DNA replication. Here we show that the CULLIN3 E3 ubiquitin ligase adaptor protein SPOP binds Geminin at endogenous level and regulates DNA replication. SPOP promotes K27-linked non-degradative poly-ubiquitination of Geminin at lysine residues 100 and 127. This poly-ubiquitination of Geminin prevents DNA replication over-firing by indirectly blocking the association of Cdt1 with the MCM protein complex, an interaction required for DNA unwinding and replication. SPOP is frequently mutated in certain human cancer types and implicated in tumorigenesis. We show that cancer-associated SPOP mutations impair Geminin K27-linked poly-ubiquitination and induce replication origin over-firing and re-replication. The replication stress caused by SPOP mutations triggers replication catastrophe and cell death upon ATR inhibition. Our results reveal a tumor suppressor role of SPOP in preventing DNA replication over-firing and genome instability and suggest that SPOP-mutated tumors may be susceptible to ATR inhibitor therapy.


Subject(s)
Geminin/metabolism , Nuclear Proteins/genetics , Repressor Proteins/genetics , Ubiquitin-Protein Ligase Complexes/genetics , Animals , Cell Cycle Proteins/genetics , Cell Cycle Proteins/metabolism , DNA Replication/genetics , DNA Replication/physiology , Geminin/genetics , Humans , Male , Mice , Mice, SCID , Minichromosome Maintenance Proteins/genetics , Minichromosome Maintenance Proteins/metabolism , Mutation/genetics , Ubiquitination/genetics , Ubiquitination/physiology
9.
Methods Mol Biol ; 2329: 291-309, 2021.
Article in English | MEDLINE | ID: mdl-34085231

ABSTRACT

The cell and cilia cycles are inextricably linked through the dual functions of the centrioles at both the basal body of cilia and at mitotic centrosomes. How cilia assembly and disassembly, either through slow resorption or rapid deciliation, are coordinated with cell cycle progression remains unclear in many cell types and developmental paradigms. Moreover, little is known about how additional cilia parameters including changes in ciliary length or frequency of distal tip shedding change with cell cycle stage. In order to explore these questions, we have developed the Arl13bCerulean-Fucci2a tricistronic cilia and cell cycle biosensor (Ford et al., Dev Cell 47:509-523.e7, 2018). This reporter allowed us to document the heterogeneity in ciliary behaviors during the cell cycle at a population level. Without the need for external stimuli, it revealed that in several cell types and in the developing embryo cilia persist beyond the G1/S checkpoint. Here, we describe the generation of stable cell lines expressing Arl13bCerulean-Fucci2a and open-source software to aid morphometric profiling of the primary cilium with cell cycle phases, including changes in cilium length. This resource will allow the investigation of multiple morphometric questions relating to cilia and cell cycle biology.


Subject(s)
Biosensing Techniques/methods , Cilia/metabolism , Recombinant Fusion Proteins/metabolism , 3T3 Cells , Animals , Cell Cycle , Cell Cycle Proteins/chemistry , Cell Cycle Proteins/metabolism , Geminin/chemistry , Geminin/metabolism , Humans , Luminescent Proteins/metabolism , Mice , Microscopy, Confocal , Protein Domains , Recombinant Fusion Proteins/chemistry , Red Fluorescent Protein
10.
Elife ; 102021 05 19.
Article in English | MEDLINE | ID: mdl-34009124

ABSTRACT

To study disease development, an inventory of an organ's cell types and understanding of physiologic function is paramount. Here, we performed single-cell RNA-sequencing to examine heterogeneity of murine pancreatic duct cells, pancreatobiliary cells, and intrapancreatic bile duct cells. We describe an epithelial-mesenchymal transitory axis in our three pancreatic duct subpopulations and identify osteopontin as a regulator of this fate decision as well as human duct cell dedifferentiation. Our results further identify functional heterogeneity within pancreatic duct subpopulations by elucidating a role for geminin in accumulation of DNA damage in the setting of chronic pancreatitis. Our findings implicate diverse functional roles for subpopulations of pancreatic duct cells in maintenance of duct cell identity and disease progression and establish a comprehensive road map of murine pancreatic duct cell, pancreatobiliary cell, and intrapancreatic bile duct cell homeostasis.


Subject(s)
Gene Expression Profiling , Genetic Heterogeneity , Pancreatic Ducts/cytology , Single-Cell Analysis , Transcriptome , Animals , Cell Line , Cell Separation , DNA Damage , Databases, Genetic , Disease Models, Animal , Epithelial-Mesenchymal Transition , Female , Geminin/genetics , Geminin/metabolism , Gene Expression Regulation, Developmental , Humans , Mice, Inbred C57BL , Mice, Transgenic , Morphogenesis , Osteopontin/genetics , Osteopontin/metabolism , Pancreatic Ducts/metabolism , Pancreatitis, Chronic/genetics , Pancreatitis, Chronic/metabolism , Pancreatitis, Chronic/pathology , Phenotype , RNA-Seq
11.
Dev Biol ; 464(1): 11-23, 2020 08 01.
Article in English | MEDLINE | ID: mdl-32450229

ABSTRACT

Development of the complex structure of the vertebrate limb requires carefully orchestrated interactions between multiple regulatory pathways and proteins. Among these, precise regulation of 5' Hox transcription factor expression is essential for proper limb bud patterning and elaboration of distinct limb skeletal elements. Here, we identified Geminin (Gmnn) as a novel regulator of this process. A conditional model of Gmnn deficiency resulted in loss or severe reduction of forelimb skeletal elements, while both the forelimb autopod and hindlimb were unaffected. 5' Hox gene expression expanded into more proximal and anterior regions of the embryonic forelimb buds in this Gmnn-deficient model. A second conditional model of Gmnn deficiency instead caused a similar but less severe reduction of hindlimb skeletal elements and hindlimb polydactyly, while not affecting the forelimb. An ectopic posterior SHH signaling center was evident in the anterior hindlimb bud of Gmnn-deficient embryos in this model. This center ectopically expressed Hoxd13, the HOXD13 target Shh, and the SHH target Ptch1, while these mutant hindlimb buds also had reduced levels of the cleaved, repressor form of GLI3, a SHH pathway antagonist. Together, this work delineates a new role for Gmnn in modulating Hox expression to pattern the vertebrate limb.


Subject(s)
Embryo, Mammalian/embryology , Geminin/metabolism , Gene Expression Regulation, Developmental , Hindlimb/embryology , Homeodomain Proteins/metabolism , Transcription Factors/metabolism , Animals , Embryo, Mammalian/cytology , Geminin/genetics , Hedgehog Proteins/genetics , Hedgehog Proteins/metabolism , Hindlimb/cytology , Homeodomain Proteins/genetics , Mice , Mice, Transgenic , Patched-1 Receptor/genetics , Patched-1 Receptor/metabolism , Transcription Factors/genetics
12.
Sci Rep ; 9(1): 19150, 2019 12 16.
Article in English | MEDLINE | ID: mdl-31844158

ABSTRACT

Dissemination of metastatic precursors from primaries is the primary reason for patient death. Dissemination encompasses tumor cells invasion of stroma, followed by intravasation through the endothelium barrier into the bloodstream. Here, we describe how geminin-overexpressing tumor cells acquire dissemination ability. Acetylated HMGB1 (Ac-HMGB1) secreted by geminin-overexpressing cells activates RAGE and CXCR4 expression on mesenchymal stem cells (MSCs) located in tumor stroma. Through secreting CXCL12, geminin-overexpressing cells recruit these CXCR4+-MSCs into the tumor. Within the tumor, MSCs differentiate into S100A4-secreting cancer-associated fibroblasts (CAFs). S100A4, in a reciprocal manner, activates geminin-overexpressing cells to secrete CCL2 that recruits M0-macrophages from the stroma into the tumor. Within the tumor, CCL2 polarizes M0-macrophages into Gas6-secreting M2-tumor-associated macrophages (M2-TAMs). In concert, geminin-overexpression, S100A4/RAGE and Gas6/AXL signaling promote the invasive and intravasation abilities in geminin-overexpressing cells through exacerbating their stemness and epithelial-to-mesenchymal phenotypes and enhancing expression and functional interaction of CD151 and α3ß1-integrin in geminin-overexpressing cells. Tumors formed following injection of geminin-overexpressing cells admixed with MSCs/CAFs grew faster, metastasized earlier, especially to lungs, and were extremely sensitive to anti-c-Abl, anti-RAGE, and anti-AXL drugs. These data support an intrinsic ability in geminin-overexpressing tumor cells to promote their metastatic potential through recruitment and bi-directional interactions with MSCs/CAFs and M2-TAMs.


Subject(s)
Geminin/metabolism , Proto-Oncogene Proteins/metabolism , Receptor Protein-Tyrosine Kinases/metabolism , Receptor for Advanced Glycation End Products/metabolism , Triple Negative Breast Neoplasms/metabolism , Triple Negative Breast Neoplasms/pathology , Animals , Cancer-Associated Fibroblasts/metabolism , Cancer-Associated Fibroblasts/pathology , Cell Line, Tumor , Cell Polarity , Female , Humans , Imatinib Mesylate/pharmacology , Macrophage Activation , Macrophages/pathology , Mesenchymal Stem Cells , Mice, SCID , Neoplasm Invasiveness , Neoplasm Metastasis , S100 Calcium-Binding Protein A4/metabolism , Axl Receptor Tyrosine Kinase
13.
Cancer Genomics Proteomics ; 16(6): 593-601, 2019.
Article in English | MEDLINE | ID: mdl-31659113

ABSTRACT

BACKGROUND/AIM: Several links between DNA replication, pluripotency and development have been recently identified. The involvement of miRNA in the regulation of cell cycle events and pluripotency factors has also gained attention. MATERIALS AND METHODS: In the present study, we used the g:Profiler platform to analyze transcription factor binding sites, miRNA networks and protein-protein interactions to identify novel links among the aforementioned processes. RESULTS AND CONCLUSION: A complex circuitry between retinoic acid signaling, SWI/SNF components, pluripotency factors including Oct4, Sox2 and Nanog and cell cycle regulators was identified. It is suggested that the DNA replication inhibitor geminin plays a central role in this circuitry.


Subject(s)
Databases, Genetic , Geminin/metabolism , Pluripotent Stem Cells/metabolism , Signal Transduction/drug effects , Tretinoin/pharmacology , Cell Cycle Proteins/metabolism , Humans , MicroRNAs/metabolism
14.
Cancer Res ; 79(19): 4896-4910, 2019 10 01.
Article in English | MEDLINE | ID: mdl-31431461

ABSTRACT

DNA rereplication leads to genomic instability and has been implicated in the pathology of a variety of human cancers. Eukaryotic DNA replication is tightly controlled to ensure it occurs only once during each cell cycle. Geminin is a critical component of this control, it prevents DNA rereplication from occurring during S, G2, and early M phases by preventing MCM helicases from forming prereplication complexes. Geminin is targeted for degradation by the anaphase-promoting complex (APC/C) from anaphase through G1-phase, however, accumulating evidence indicates that Geminin is downregulated in late S-phase due to an unknown mechanism. Here, we used a high-throughput screen to identify miRNAs that can induce excess DNA replication and found that miR-571 could reduce the protein level of Geminin in late S-phase independent of the APC/C. Furthermore, miR-571 regulated efficient DNA replication and S-phase cell-cycle progression. Strikingly, c-Myc suppressed miR-571 expression by binding directly to the miR-571 promoter. At the beginning of S-phase, Cdk2 phosphorylated c-Myc at Serine 62, promoting its association with the miR-571 promoter region. Collectively, we identify miR-571 as the first miRNA that prevents aberrant DNA replication and the Cdk2-c-Myc-miR-571 axis as a new pathway for regulating DNA replication, cell cycle, and genomic stability in cancer cells. SIGNIFICANCE: These findings identify a novel regulatory mechanism that is critical for maintaining genome integrity by regulating DNA replication and cell-cycle progression.


Subject(s)
Cyclin-Dependent Kinase 2/metabolism , DNA Replication/physiology , Geminin/metabolism , Genomic Instability/physiology , MicroRNAs/metabolism , Proto-Oncogene Proteins c-myc/metabolism , Cell Cycle/physiology , Cell Line, Tumor , Gene Expression Regulation/physiology , Humans , MicroRNAs/genetics , Signal Transduction/physiology
15.
J Oral Pathol Med ; 48(10): 888-896, 2019 Nov.
Article in English | MEDLINE | ID: mdl-31318980

ABSTRACT

BACKGROUND: Carcinogenesis occurs when the cell cycle is compromised. Chromatin licensing and DNA replication factor 1, geminin, and γ-H2A histone family member X are expressed in cells in G1 phase, S/G2 /M phases, and apoptosis, respectively, and these three markers may be useful for histological evaluation of malignant lesions. Here, we aimed to identify cell cycle phases and apoptosis using immunohistochemistry in oral epithelial precursor lesions and oral squamous cell carcinoma. METHODS: Chromatin licensing and DNA replication factor 1, geminin, and γ-H2A histone family member X expression levels were immunohistochemically examined in tissue specimens from 55 patients with oral epithelial precursor lesions and 50 patients with oral squamous cell carcinoma. Associations of clinicopathological variables with marker expression were assessed. RESULTS: Chromatin licensing and DNA replication factor 1 was expressed in the prickle cell layer of oral epithelial precursor lesions and many carcinoma cells of oral squamous cell carcinoma. Geminin reactivity was widely distributed in high-grade dysplasia and oral squamous cell carcinoma rather than low-grade or no dysplastic cases. γ-H2A histone family member X was expressed in the superficial layer of oral epithelial precursor lesions and scattered carcinoma cells of oral squamous cell carcinoma. In oral squamous cell carcinoma, lower geminin expression was observed in recurrent cases. Geminin and γ-H2A histone family member X were associated with the degree of differentiation and mode of invasion. CONCLUSION: Chromatin licensing and DNA replication factor 1, geminin, and γ-H2A histone family member X expression levels were correlated with oral carcinogenesis; these markers were associated with clinicopathological behaviors in oral squamous cell carcinoma.


Subject(s)
Carcinoma, Squamous Cell/metabolism , Cell Cycle Proteins/metabolism , Geminin/metabolism , Histones/metabolism , Mouth Neoplasms/metabolism , Adult , Aged , Aged, 80 and over , Biomarkers, Tumor/metabolism , Carcinoma, Squamous Cell/pathology , Female , Humans , Immunohistochemistry , Male , Middle Aged , Mouth Neoplasms/pathology
16.
Neuron ; 102(1): 159-172.e7, 2019 04 03.
Article in English | MEDLINE | ID: mdl-30824354

ABSTRACT

Adult neural stem cells and multiciliated ependymal cells are glial cells essential for neurological functions. Together, they make up the adult neurogenic niche. Using both high-throughput clonal analysis and single-cell resolution of progenitor division patterns and fate, we show that these two components of the neurogenic niche are lineally related: adult neural stem cells are sister cells to ependymal cells, whereas most ependymal cells arise from the terminal symmetric divisions of the lineage. Unexpectedly, we found that the antagonist regulators of DNA replication, GemC1 and Geminin, can tune the proportion of neural stem cells and ependymal cells. Our findings reveal the controlled dynamic of the neurogenic niche ontogeny and identify the Geminin family members as key regulators of the initial pool of adult neural stem cells.


Subject(s)
Astrocytes/cytology , Ependyma/cytology , Ependymoglial Cells/cytology , Neural Stem Cells/cytology , Adult Stem Cells/cytology , Adult Stem Cells/metabolism , Animals , Astrocytes/metabolism , Carrier Proteins/metabolism , Cell Cycle Proteins , Cell Lineage , DNA Replication , Electroporation , Embryo, Mammalian , Ependymoglial Cells/metabolism , Geminin/metabolism , Mice , Neural Stem Cells/metabolism
17.
Sci Rep ; 9(1): 956, 2019 01 30.
Article in English | MEDLINE | ID: mdl-30700744

ABSTRACT

Epigenetic information (epigenome) on chromatin is crucial for the determination of cellular identity and for the expression of cell type-specific biological functions. The cell type-specific epigenome is maintained beyond replication and cell division. Nucleosomes of chromatin just after DNA replication are a mixture of old histones with the parental epigenome and newly synthesized histones without such information. The diluted epigenome is mostly restored within one cell cycle using the epigenome on the parental DNA and nucleosomes as replication templates. However, many important questions about the epigenome replication process remain to be clarified. In this study, we investigated the model system comprising of dimethylated histone H3 lysine 9 (H3K9me2) and its regulation by the lysine methyltransferase G9a. Using this epigenome model system, we addressed whether H3K9me2 can be induced in specific cell cycle stages, especially G1. Using cell cycle-specific degrons, we achieved G1 or late G1-to M phases specific accumulation of exogenous G9a in G9a deficient cells. Importantly, global levels of H3K9me2 were significantly recovered by both cell types. These data indicate that H3K9me2 may be plastic and inducible, even in the long-living, terminally-differentiated, post-mitotic, G0-G1 cell population in vivo. This knowledge is valuable in designing epigenome-manipulation-based treatments for diseases.


Subject(s)
G1 Phase , Histone-Lysine N-Methyltransferase/metabolism , Histones/metabolism , Animals , Cell Line , Female , Geminin/metabolism , Humans , Lysine/metabolism , Methylation , Mice, Knockout , Mitosis
18.
Herz ; 44(8): 712-716, 2019 Dec.
Article in English | MEDLINE | ID: mdl-30151710

ABSTRACT

Geminin, a key regulator of DNA replication licensing in the cell cycle, plays an essential role in determining the fate of cells via suppression of cell proliferation and cellular differentiation. Neuropeptide Y (NPY) intensifies the proliferation of vascular smooth muscle cells (VSMCs) directly by binding with Y1 receptors. In vitro experiments have shown that stimulation of NPY on VSMCs via regulation of geminin is a double-edged sword. Given that the proliferation and the phenotypic transformation of VSMCs increase the risk for progression of atherosclerosis, we focus on the role of geminin interference in determining the fate of VSMCs. Furthermore, we discuss the therapeutic potential of peripheral neurotransmitter interference, thus pointing toward future research directions in the treatment of atherosclerosis.


Subject(s)
Geminin , Muscle, Smooth, Vascular , Neuropeptide Y , Cell Proliferation , Geminin/metabolism , Muscle, Smooth, Vascular/metabolism , Myocytes, Smooth Muscle , Neuropeptide Y/physiology
19.
J Virol ; 93(5)2019 03 01.
Article in English | MEDLINE | ID: mdl-30541837

ABSTRACT

Kaposi's sarcoma-associated herpesvirus (KSHV) is a human oncogenic virus, which maintains the persistent infection of the host by intermittently reactivating from latently infected cells to produce viral progenies. While it is established that the replication and transcription activator (RTA) viral transcription factor is required for the induction of lytic viral genes for KSHV lytic reactivation, it is still unknown to what extent RTA alters the host transcriptome to promote KSHV lytic cycle and viral pathogenesis. To address this question, we performed a comprehensive time course transcriptome analysis during KSHV reactivation in B-cell lymphoma cells and determined RTA-binding sites on both the viral and host genomes, which resulted in the identification of the core RTA-induced host genes (core RIGs). We found that the majority of RTA-binding sites at core RIGs contained the canonical RBP-Jκ-binding DNA motif. Subsequently, we demonstrated the vital role of the Notch signaling transcription factor RBP-Jκ for RTA-driven rapid host gene induction, which is consistent with RBP-Jκ being essential for KSHV lytic reactivation. Importantly, many of the core RIGs encode plasma membrane proteins and key regulators of signaling pathways and cell death; however, their contribution to the lytic cycle is largely unknown. We show that the cell cycle and chromatin regulator geminin and the plasma membrane protein gamma-glutamyltransferase 6, two of the core RIGs, are required for efficient KSHV reactivation and virus production. Our results indicate that host genes that RTA rapidly and directly induces can be pivotal for driving the KSHV lytic cycle.IMPORTANCE The lytic cycle of KSHV is involved not only in the dissemination of the virus but also viral oncogenesis, in which the effect of RTA on the host transcriptome is still unclear. Using genomics approaches, we identified a core set of host genes which are rapidly and directly induced by RTA in the early phase of KSHV lytic reactivation. We found that RTA does not need viral cofactors but requires its host cofactor RBP-Jκ for inducing many of its core RIGs. Importantly, we show a critical role for two of the core RIGs in efficient lytic reactivation and replication, highlighting their significance in the KSHV lytic cycle. We propose that the unbiased identification of RTA-induced host genes can uncover potential therapeutic targets for inhibiting KSHV replication and viral pathogenesis.


Subject(s)
Herpesvirus 8, Human/genetics , Immediate-Early Proteins/genetics , Immunoglobulin J Recombination Signal Sequence-Binding Protein/metabolism , Trans-Activators/genetics , Virus Activation/genetics , Cell Line, Tumor , Geminin/genetics , Geminin/metabolism , Gene Expression Profiling , Gene Expression Regulation, Viral/genetics , HEK293 Cells , Herpesvirus 8, Human/metabolism , Herpesvirus 8, Human/pathogenicity , Humans , RNA Interference , RNA, Small Interfering/genetics , Virus Latency/genetics , gamma-Glutamyltransferase/genetics , gamma-Glutamyltransferase/metabolism
20.
Stem Cells Transl Med ; 7(11): 792-805, 2018 11.
Article in English | MEDLINE | ID: mdl-30272835

ABSTRACT

Cell transplantation holds considerable promise for end-stage liver diseases but identifying a suitable, transplantable cell type has been problematic. Here, we describe a novel type of mesenchymal stem cells (MSCs) from human adipose tissue. These cells are different from previously reported MSCs, they are in the euchromatin state with epigenetic multipotency, and express pluripotent markers MYC, KLF4, and GMNN. Most of the genes associated with germ layer specification are modified by H3K4me3 or co-modified by H3K4me3 and H3K27me3. We named this new type of MSCs as adult multipotent adipose-derived stem cells (M-ADSCs). Using a four-step nonviral system, M-ADSCs can be efficiently Induced into hepatocyte like cells with expression of hepatocyte markers, drug metabolizing enzymes and transporters, and the other basic functional properties including albumin (ALB) secretion, glycogen storage, detoxification, low-density lipoprotein intake, and lipids accumulation. In vivo both M-ADSCs-derived hepatoblasts and hepatocytes could form vascularized liver-like tissue, secrete ALB and express metabolic enzymes. Single-cell RNA-seq was used to investigate the important stages in this conversion. M-ADSCs could be converted to a functionally multipotent state during the preinduction stage without undergoing reprogramming process. Our findings provide important insights into mechanisms underlying cell development and conversion. Stem Cells Translational Medicine 2018;7:792-805.


Subject(s)
Geminin/metabolism , Hepatocytes/metabolism , Kruppel-Like Transcription Factors/metabolism , Mesenchymal Stem Cells/metabolism , Proto-Oncogene Proteins c-myc/metabolism , Adipose Tissue/cytology , Animals , Biomarkers/metabolism , Cell Differentiation , Geminin/genetics , Hepatocyte Nuclear Factor 4/genetics , Hepatocyte Nuclear Factor 4/metabolism , Hepatocytes/cytology , Humans , Kruppel-Like Factor 4 , Kruppel-Like Transcription Factors/genetics , Liver/metabolism , Mesenchymal Stem Cells/cytology , Mice , Mice, Nude , Proto-Oncogene Proteins c-myc/genetics , RNA/chemistry , RNA/isolation & purification , RNA/metabolism , Sequence Analysis, RNA , Single-Cell Analysis , Transcriptome , alpha-Fetoproteins/genetics , alpha-Fetoproteins/metabolism
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