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*

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

OBJECTIVETo study the effect of telomerase reverse transcriptase (TERT) on cell apoptosis in neonatal rat brains after hypoxic-ischemic brain injury (HIBD).

METHODSA total of 72 neonatal rats were divided into sham, vehicle, HIBD and TERT groups. HIBD was induced by Rice method in the later three groups. The neonatal rats in the vehicle and TERT groups were injected with plasmids containing mock or full length TERT by an intracerebroventricular injection 30 minutes after hypoxic-ischemic (HI) injury. Pathological changes of brain tissue were observed by hematoxylin and eosin (HE) staining. Western blot was used to detect the protein expression of TERT, apoptosis-inducing factor (AIF) and cleaved caspase 3 (CC3). Apoptotic cells were detected by TUNEL staining.

RESULTSWestern blot showed that TERT protein was dramatically increased in the vehicle, HIBD and TERT groups compared with the sham group. Compared with the vehicle and HIBD groups, TERT protein in the TERT group was significantly upregulated. Compared with the sham group, there was a significant increase in apoptotic index and expression of AIF and CC3 proteins in the vehicle and HIBD groups (p<0.01). The TERT group showed decreased expression of AIF and CC3 proteins and apoptotic index compared with the vehicle and HIBD groups (p<0.01).

CONCLUSIONSTERT can inhibit cell apoptosis induced by HI and might have a neuroprotective role in developing brain with HIBD.

Animals ; Animals, Newborn ; Apoptosis ; Caspase 3 ; metabolism ; Hypoxia-Ischemia, Brain ; pathology ; therapy ; Male ; Rats ; Rats, Sprague-Dawley ; Telomerase ; genetics

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

The development of hepatocellular carcinoma (HCC) is a complex process, and HCC arises from the accumulation of multiple genetic alterations leading to changes in the genomic landscape. Current advances in genomic technologies have revolutionized the search for genetic alterations in cancer genomes. Recent studies in which all coding exons in HCC were sequenced have shed new light on the genomic landscape of this malignant disease. Catalogues of these somatic mutations and systematic analysis of catalogued mutations will lead us to uncover candidate HCC driver genes, although further functional validation is needed to determine whether these genes play a causal role in the development of HCC. This review provides an overview of previously known oncogenes and new oncogene candidates in HCC that were uncovered from recent exome or whole-genome sequencing studies. This knowledge provides direction for future personalized treatment approaches for patients with HCC.
Carcinoma, Hepatocellular/*pathology/therapy ; Humans ; Intracellular Signaling Peptides and Proteins/metabolism ; Liver Neoplasms/*pathology/therapy ; Mutation ; Oxidative Stress ; Precision Medicine ; Telomerase/metabolism ; Transcription Factors/genetics/metabolism ; Tumor Suppressor Protein p53/genetics/metabolism

OBJECTIVETo observe targeted expression of recombinant lentivirus-mediated (Lv)-hTERTp-TK and Lv-hTERTp-tumstatin in HepG2 cells, and explore the inhibitory effect of their combination on HepG2 cells both in vitro and in vivo.

METHODSLv-hTERTp-TK and Lv-hTERTptumstatin were used to infect HepG2 and L02 cells at different MOIs. Transfection efficiency was observed by fluorescence microscopy. Expression of TK and tumstatin mRNA was detected by reverse-transcriptase PCR. Proliferation and apoptosis were detected by MTT and flow cytometry, respectively. The HepG2 cells were examined by real time-PCR and western blotting to determine expression level of bcl-2 and VEGF mRNA and protein.A murine hepatocellular carcinoma model was established by injecting 1 * 10(7) HepG2 cells into 30 BALB/c nude mice. The modeled mice were randomly divided into a control group, mock group, Lv-hTERTp-tumstatin group, Lv-hTERTp-TK group, and combination group for four weeks of injections at regular intervals of PBS, Lv-hTERTp-null, Lv-hTERTp-tumstatin, Lv-hTERTp-TK, and Lv-hTERTp-tumstatin plus Lv-hTERTp-TK, respectively.Changes in tumor volume and weight, and cell morphology of tumor and major organs, were assessed by hematoxylin-eosin staining.Microvascular density of tumor tissue and cell apoptosis were assessed by immunohistochemical and TUNEL staining, respectively.

RESULTSThe Lv-infected HepG2 cells, and not the Lv-infected L02 cells, expressed TK and tumstatin. Lv-hTERTp-TK and Lv-hTERTp-tumstatin, alone or in combination, inhibited proliferation and increased apoptosis of the HepG2 cells, but the combination was more effective than either alone (P less than 0.05). None of the treatments affected proliferation or apoptosis of the L02 cells (P more than 0.05). The combination also led to a greater reduction of bcl-2 and VEGF than either alone (all, P less than 0.05). Tumor growth was significantly inhibited by the combination (P less than 0.05). In vivo, the combination treatment induced the greatest amount of apoptosis of the HepG2 cells. Cell morphology of major organs such as liver, spleen and kidney were similar to the control group. The combination also produced the most significant effect on tumor microvascular density (P less than 0.05) and the highest apoptosis index (P less than 0.05).

CONCLUSIONThe HTERT promoter can induce targeted expression of TK and tumstatin in HepG2 cells. Lv-hTERTp-TK combined with Lv-hTERTp-tumstatin can significantly inhibit proliferation and induce apoptosis of human HepG2 cells in vitro and in vivo, which may be related to down-regulation ofbcl-2 and VEGF.

Animals ; Apoptosis ; Autoantigens ; genetics ; Carcinoma, Hepatocellular ; therapy ; Cell Line, Tumor ; Collagen Type IV ; genetics ; Down-Regulation ; Flow Cytometry ; Gene Transfer Techniques ; Genetic Therapy ; Genetic Vectors ; Hep G2 Cells ; Humans ; Lentivirus ; Liver Neoplasms ; therapy ; Mice ; Mice, Inbred BALB C ; Mice, Nude ; Neoplasm Transplantation ; Proto-Oncogene Proteins c-bcl-2 ; metabolism ; Telomerase ; genetics ; Transfection ; Vascular Endothelial Growth Factor A ; 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

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 study the in-vitro inducing apoptosis mechanism of human hepatoma SMMC-7721 cells by 2',4'-di- hydroxy-6'-methoxy-3',5'-dimethylchalcone (DMC), a chalcone compound from Cleistocalyx operculatus.

METHODQuantitative DNA fragmentation assay was carried out to detect the effect of DMC of different concentrations on SMMC-7721 cells, according to the method of Sellins and Cohen with some modifications. Telomerase activities of the cells were determined by PCR-ELISA methods. The expression quantity of c-myc and hTERT mRNA were determined by semi-quantitative RT-PCR The effect of DMC on expression levels of cmyc and hTERT protein were measured by western blot.

RESULTThe percentage of DNA fragmentation increased with notable concen- tration dependence, after treatment with DMC for 48 h. Compared with that of control group, the telomerase activity of the cells de- creased by (66.2 ± 2.1)% after 48 h treatment with 20 μmol x L(-1) DMC, the mRNA expression of c-myc and hTERT decreased by (67.3 ± 2.1)% and (64.4 ± 2.3)%, respectively, and the protein expression of c-myc and hTERT decreased by (69.6 ± 1.9)% and (71.3 ± 2.4)%, respectively.

CONCLUSIONDMC can induce SMMC-7721 cell apoptosis and the apoptosis mechanism may be related to the decreased mRNA and protein expression of c-myc and hTERT.

Antineoplastic Agents ; pharmacology ; Apoptosis ; drug effects ; Carcinoma, Hepatocellular ; pathology ; Cell Line, Tumor ; Chalcones ; pharmacology ; DNA Fragmentation ; drug effects ; Dose-Response Relationship, Drug ; Humans ; Liver Neoplasms ; pathology ; Proto-Oncogene Proteins c-myc ; genetics ; metabolism ; RNA, Messenger ; genetics ; metabolism ; Syzygium ; chemistry ; Telomerase ; genetics ; metabolism