Lamin B1 (LMNB1) is highly expressed in liver cancer tissues, and its influence and mechanism on the proliferation of hepatocellular carcinoma cells were explored by knocking down the expression of the protein. In liver cancer cells, siRNAs were used to knock down LMNB1. Knockdown effects were detected by Western blotting. Changes in telomerase activity were detected by telomeric repeat amplification protocol assay (TRAP) experiments. Telomere length changes were detected by quantitative real-time polymerase chain reaction (qPCR). CCK8, cloning formation, transwell and wound healing were performed to detect changes in its growth, invasion and migration capabilities. The lentiviral system was used to construct HepG2 cells that steadily knocked down LMNB1. Then the changes of telomere length and telomerase activity were detected, and the cell aging status was detected by SA-β-gal senescence staining. The effects of tumorigenesis were detected by nude mouse subcutaneous tumorigenesis experiments, subsequent histification staining of tumors, SA-β-gal senescence staining, fluorescence in situ hybridization (FISH) for telomere analysis and other experiments. Finally, the method of biogenesis analysis was used to find the expression of LMNB1 in clinical liver cancer tissues, and its relationship with clinical stages and patient survival. Knockdown of LMNB1 in HepG2 and Hep3B cells significantly reduced telomerase activity, cell proliferation, migration and invasion abilities. Experiments in cells and tumor formation in nude mice had demonstrated that stable knockdown of LMNB1 reduced telomerase activity, shortened telomere length, senesced cells, reduced cell tumorigenicity and KI-67 expression. Bioinformatics analysis showed that LMNB1 was highly expressed in liver cancer tissues and correlated with tumor stage and patient survival. In conclusion, LMNB1 is overexpressed in liver cancer cells, and it is expected to become an indicator for evaluating the clinical prognosis of liver cancer patients and a target for precise treatment.
Animals ; Mice ; Telomerase/metabolism* ; Carcinoma, Hepatocellular/genetics* ; Liver Neoplasms/genetics* ; Telomere Shortening ; In Situ Hybridization, Fluorescence ; Mice, Nude ; Telomere/pathology* ; Carcinogenesis

OBJECTIVE: To investigate the cytotoxic effect and its mechanism of the micromolecule compound on the leukemia cells. METHODS: The cytotoxic effects of 28 Nilotinib derivatives on K562, KA, KG, HA and 32D cell lines were detected by MTT assays, and the compound Nilo 22 was screen out. Cell apoptosis and cell cycle on leukemia cells were detected by flow cytometry. The effect of compound screened out on leukemogenesis potential of MLL-AF9 leukemia mice GFP RESULTS: Nilo 22 serves as the most outstanding candidate out of 28 Nilotinib derivatives, which impairs leukemia cell lines, but spares normal hematopoietic cell line. Comparing with Nilotinib, Nilo 22 could induce the apoptosis of GFP CONCLUSION Nilo 22 shows a significant cytotoxic effect on mice and human leukemia cells, especially for drug resistance cells. Nilo 22 is a promising anti-leukemia agent to solve the common clinical problems of drug resistance and relapse of leukemia.
Animals ; Apoptosis/drug effects* ; Cell Cycle/drug effects* ; Cell Line, Tumor ; Humans ; Leukemia ; Mice ; Myeloid-Lymphoid Leukemia Protein/genetics* ; Telomerase/metabolism* ; Telomere/metabolism*

BACKGROUND: Heat shock protein 70 (HSP70) exhibits protective effects against ultraviolet (UV)-induced premature skin aging. A standardized extract of Asparagus officinalis stem (EAS) is produced as a novel and unique functional food that induces HSP70 cellular expression. To elucidate the anti-photoaging potencies of EAS, we examined its effects on HSP70 expression levels in UV-B-irradiated normal human dermal fibroblasts (NHDFs). METHODS: NHDFs were treated with 1 mg/mL of EAS or dextrin (vehicle control) prior to UV-B irradiation (20 mJ/cm). After culturing NHDFs for different time periods, HSP70 mRNA and protein levels were analyzed using real-time polymerase chain reaction and western blotting, respectively. RESULTS: UV-B-irradiated NHDFs showed reduced HSP70 mRNA levels after 1-6 h of culture, which were recovered after 24 h of culture. Treatment with EAS alone for 24 h increased HSP70 mRNA levels in the NHDFs, but the increase was not reflected in its protein levels. On the other hand, pretreatment with EAS abolished the UV-B irradiation-induced reduction in HSP70 expression at both mRNA and protein levels. These results suggest that EAS is capable to preserve HSP70 quantity in UV-B-irradiated NHDFs. CONCLUSIONS EAS exhibits anti-photoaging potencies by preventing the reduction in HSP70 expression in UV-irradiated dermal fibroblasts.
Asparagus Plant ; Cells, Cultured ; Female ; Fibroblasts ; drug effects ; radiation effects ; HSP70 Heat-Shock Proteins ; biosynthesis ; Humans ; Middle Aged ; Plant Extracts ; pharmacology ; Polymerase Chain Reaction ; Skin ; drug effects ; radiation effects ; Skin Aging ; drug effects ; radiation effects ; Telomere ; metabolism ; Ultraviolet Rays ; adverse effects

Human telomerase reverse transcriptase (hTERT) plays a central role in telomere lengthening for continuous cell proliferation, but it remains unclear how extracellular cues regulate telomerase lengthening of telomeres. Here we report that the cytokine bone morphogenetic protein-7 (BMP7) induces the hTERT gene repression in a BMPRII receptor- and Smad3-dependent manner in human breast cancer cells. Chonic exposure of human breast cancer cells to BMP7 results in short telomeres, cell senescence and apoptosis. Mutation of the BMPRII receptor, but not TGFbRII, ACTRIIA or ACTRIIB receptor, inhibits BMP7-induced repression of the hTERT gene promoter activity, leading to increased telomerase activity, lengthened telomeres and continued cell proliferation. Expression of hTERT prevents BMP7-induced breast cancer cell senescence and apoptosis. Thus, our data suggest that BMP7 induces breast cancer cell aging by a mechanism involving BMPRII receptor- and Smad3-mediated repression of the hTERT gene.
Actin-Related Protein 2 ; genetics ; metabolism ; Activin Receptors, Type II ; genetics ; metabolism ; Bone Morphogenetic Protein 7 ; genetics ; metabolism ; Bone Morphogenetic Protein Receptors, Type II ; genetics ; metabolism ; Breast Neoplasms ; genetics ; metabolism ; Cellular Senescence ; Female ; HeLa Cells ; Humans ; MCF-7 Cells ; Neoplasm Proteins ; genetics ; metabolism ; Protein-Serine-Threonine Kinases ; genetics ; metabolism ; Receptor, Transforming Growth Factor-beta Type II ; Receptors, Transforming Growth Factor beta ; genetics ; metabolism ; Smad3 Protein ; genetics ; metabolism ; Telomerase ; genetics ; metabolism ; Telomere Homeostasis

Folate, vitamin B12, and homocysteine (HCY) are involved in the metabolism of nucleic acid precursors and it has been hypothesized that they also influence telomere length, a biomarker of aging. However, previous studies have reported inconsistent findings, and data for older adults are limited. Our study aimed to evaluate associations between leukocyte telomere length (LTL) and serum folate, vitamin B12, and HCY levels among adults aged 55 years and over. In a cross-sectional study in 798 men and women aged 55-79 years, serum folate, vitamin B12, and HCY levels were measured using chemiluminescent immunometric assays, and relative LTL was assessed using quantitative real-time polymerase chain reaction. To evaluate associations between LTL and serum folate, vitamin B12, and HCY levels, multiple linear regression models were used. In multiple models adjusted for age, sex, serum high sensitive C-reactive protein (hs-CRP) levels, and other potential confounding factors, we found no association between LTL and serum folate, vitamin B12, and HCY levels. However, we did find a significant inverse association between HCY levels and LTL in participants with serum hs-CRP levels of > or = 2 mg/L (p < 0.05). Moreover, there was a trend toward an association between HCY and vitamin B12 levels in these individuals (p = 0.08). In those with serum hs-CRP levels of < 2 mg/L, HCY was inversely associated with vitamin B12 levels (p < 0.001) and had no association with LTL. Our findings suggest that increased serum HCY levels, when combined with the presence of systemic inflammation, may play a role in accelerating biological aging.
Adult* ; Aging ; C-Reactive Protein ; Cross-Sectional Studies ; Female ; Folic Acid ; Homocysteine* ; Humans ; Inflammation* ; Leukocytes* ; Linear Models ; Male ; Metabolism ; Nucleic Acid Precursors ; Real-Time Polymerase Chain Reaction ; Telomere* ; Vitamin B 12* ; Vitamin B Complex ; Vitamins*

Werner syndrome (WS) is a premature aging disorder that mainly affects tissues derived from mesoderm. We have recently developed a novel human WS model using WRN-deficient human mesenchymal stem cells (MSCs). This model recapitulates many phenotypic features of WS. Based on a screen of a number of chemicals, here we found that Vitamin C exerts most efficient rescue for many features in premature aging as shown in WRN-deficient MSCs, including cell growth arrest, increased reactive oxygen species levels, telomere attrition, excessive secretion of inflammatory factors, as well as disorganization of nuclear lamina and heterochromatin. Moreover, Vitamin C restores in vivo viability of MSCs in a mouse model. RNA sequencing analysis indicates that Vitamin C alters the expression of a series of genes involved in chromatin condensation, cell cycle regulation, DNA replication, and DNA damage repair pathways in WRN-deficient MSCs. Our results identify Vitamin C as a rejuvenating factor for WS MSCs, which holds the potential of being applied as a novel type of treatment of WS.
Animals ; Ascorbic Acid ; pharmacology ; Cell Cycle Checkpoints ; drug effects ; Cell Line ; Cellular Senescence ; drug effects ; DNA Damage ; DNA Repair ; drug effects ; DNA Replication ; drug effects ; Disease Models, Animal ; Heterochromatin ; metabolism ; pathology ; Humans ; Mesenchymal Stem Cells ; metabolism ; pathology ; Mice ; Nuclear Lamina ; metabolism ; pathology ; Reactive Oxygen Species ; metabolism ; Telomere Homeostasis ; drug effects ; Werner Syndrome ; drug therapy ; genetics ; metabolism

BACKGROUND/AIMS: A number of genome-wide and candidate gene association studies have identified polymorphisms associated with telomere length in Caucasian populations. This study was conducted to determine the impacts of 17 polymorphisms identified in Caucasians on telomere length in a Korean population. METHODS: Ninety-four healthy individuals were enrolled in this study. Relative telomere length of chromosomes from peripheral blood samples was measured using quantitative polymerase chain reaction. RESULTS: Two polymorphisms, rs10936599 of MYNN and rs412658 of ZNF676, were found to be associated w ith telomere length (under dominant model, p = 0.04; under recessive model, p = 0.001). Three polymorphisms, rs2853669, rs7705526, and rs2736108, at the TERT locus were also associated with telomere length (under recessive model, p = 0.01, p = 0.02, and p = 0.01, respectively). The genotypes of the five polymorphisms associated with short telomere length were considered bad genotypes; telomere length was significantly decreased with increasing number of bad genotypes (p= 1.7 x 10(-5)). CONCLUSIONS: We have identified polymorphisms associated with telomere length in a Korean population.
Adult ; Aged ; Asian Continental Ancestry Group/*genetics ; Case-Control Studies ; DNA-Binding Proteins/genetics ; Female ; Genome-Wide Association Study ; Genotype ; Humans ; Kruppel-Like Transcription Factors/genetics ; Male ; Middle Aged ; Phenotype ; *Polymorphism, Single Nucleotide ; Republic of Korea ; Telomerase/genetics ; Telomere/*genetics/metabolism ; *Telomere Homeostasis ; Zinc Fingers

Telomere assumes intra-molecular G-quadruplex that is a significant drug target for inhibiting telomerase maintenance of telomeres in cancer. Metal cations have been recognized as playing important roles in stabilizing G-quadruplex, but their binding processes to human telomeric G-quadruplex remain uncharacterized. To investigate the detailed binding procedures, molecular dynamics simulations were conducted on the hybrid [3 + 1] form-one human telomeric intra-molecular G-quadruplex. We show here that the binding of a potassium ion to a G-tetrad core is mediated by two alternative pathways. Principal component analysis illustrated the dominant concerted motions of G-quadruplex occurred at the loop domains. MM-PBSA calculations revealed that binding was energetically favorable and driven by the electrostatic interactions. The lower binding site was found more constructive favorable for binding. Our data provide useful information on a potassium-mediated stable structure of human telomeric intra-molecular G-quadruplex, implicating in ion disorder associated conformational changes and targeted drug design.
Binding Sites ; G-Quadruplexes ; Humans ; Molecular Dynamics Simulation ; Movement ; Potassium ; metabolism ; Principal Component Analysis ; Substrate Specificity ; Telomere ; chemistry ; metabolism ; Thermodynamics

Telomerase reverse transcriptase (TERT) is the protein component of telomerase and combined with an RNA molecule, telomerase RNA component, forms the telomerase enzyme responsible for telomere elongation. Telomerase is essential for maintaining telomere length from replicative attrition and thus contributes to the preservation of genome integrity. Although diverse mouse models have been developed and studied to prove the physiological roles of telomerase as a telomere-elongating enzyme, recent studies have revealed non-canonical TERT activities beyond telomeres. To gain insights into the physiological impact of extra-telomeric roles, this review revisits the strategies and phenotypes of telomerase mouse models in terms of the extra-telomeric functions of telomerase.
Animals ; Mice ; Mice, Knockout ; Telomerase/genetics/*metabolism ; Telomere/metabolism

OBJECTIVETo investigate the change in telomere length and TERC and TERT mutations in peripheral blood leukocytes of children with chronic aplastic anemia (CAA).

METHODSSixty-nine children with CAA were divided into untreated group (n=24) who did not receive immunosuppressive therapy (IST), response group (n=36) who showed response to IST, and non-response group (n=9) who showed no response to IST; another 35 healthy children matched for age and sex were selected as the control group. The telomere-to-single copy gene (T/S) ratio in peripheral blood leukocytes was measured by real-time PCR in all groups. PCR was performed to detect TERC and TERT mutations in all children with CAA.

RESULTSThe untreated and non-response groups had significantly lower T/S ratios than the control and response groups (P<0.01), whereas there was no significant difference in T/S ratio between the response and control groups (P>0.05). TERC and TERT mutations were not found in all children with CAA.

CONCLUSIONSThe change in telomere length in children with CAA may be related to the development and progression of disease. Telomere length measurement may be used as a prognostic indicator in children with CAA.

Adolescent ; Anemia, Aplastic ; drug therapy ; genetics ; Child ; Child, Preschool ; Chronic Disease ; Humans ; Immunosuppressive Agents ; therapeutic use ; Infant ; Leukocytes ; metabolism ; Male ; Mutation ; Telomerase ; genetics ; Telomere