OBJECTIVETo quantitatively measure plasma level of human telomerase reverse transcriptase (hTERT) mRNA in patients with nasopharyngeal carcinoma (NPC) and explore its implications for NPC diagnosis and treatment.

METHODSWith 24 healthy volunteers serving as controls, the plasma level of hTERT mRNA was detected in 33 NPC patients by real-time PCR before and after treatments with chemotherapy or radiotherapy, and its association with the clinicopathological parameters of the patients were analyzed.

RESULTSThe NPC patients showed a significantly higher mean plasma level of hTERT mRNA than the healthy volunteers (10.75 ± 4.29 vs 0.95 ± 0.37, P<0.05). The plasma hTERT mRNA level in the NPC patients was significantly correlated with clinical staging, tumor size, and degree of nodal metastasis (P<0.05) but with gender or age (P>0.05). In patients with stage I and II NPC, the plasma hTERT mRNA level decreased significantly after radiotherapy (5.60 ± 2.33 vs 3.43 ± 1.42); in patients in advanced stages (III and IV), plasma hTERT mRNA level decreased significantly from 12.68 ± 3.08 to 10.68 ± 2.48 (P<0.05) after chemotherapy and to 3.13 ± 1.69 (P<0.05) after radiotherapy.

CONCLUSIONRadiotherapy and chemotherapy can effectively suppress elevated plasma hTERT mRNA levels in NPC patients. Plasma hTERT mRNA level is closely related to the clinicopathological factors and provides important information for early diagnosis and therapeutic effect evaluation of NPC.

Carcinoma ; Case-Control Studies ; Humans ; Nasopharyngeal Neoplasms ; blood ; RNA, Messenger ; blood ; Telomerase ; blood

STUDY DESIGN: In vitro cell culture. PURPOSE: The purpose of the study was to investigate the effect of high glucose on premature stress-induced senescence of rat notochordal cells. OVERVIEW OF LITERATURE: Glucose-mediated increase of oxidative stress is a major causative factor for the development of diseases associated with diabetes mellitus such as senescence. However, no information is available for the effect of high glucose on premature stress-induced senescence of rat notochordal cells. METHODS: Notochordal cells were isolated from 4-week-old rats, cultured and placed in either 10% fetal bovine serum (FBS, normal control) or 10% FBS plus two high glucose concentrations (0.1 M and 0.2 M, experimental conditions) for 1 and 3 days. We identified and quantified the mitochondrial damage (mitochondrial transmembrane potential), reactive oxygen species (ROS) and antioxidants, such as manganese superoxide dismutase (MnSOD) and catalase, for each condition. We also identified and quantified senescence and telomerase activity. Finally, we determined the expression of proteins related to replicative senescence (p53-p21-pRB) and stress-induced senescence (p16-pRB) pathways. RESULTS: Two high glucose concentrations enhanced the disruption of mitochondrial transmembrane potential and excessive generation of ROS in notochordal cells for 1 and 3 days, respectively. The expressions of MnSOD and catalase were increased in notochordal cells treated with both high glucose concentrations at 1 and 3 days. The telomerase activity declined at 1 and 3 days. Two high glucose concentrations increased the occurrence of stress-induced senescence of notochordal cells by p16-pRB pathways at 1 and 3 days. CONCLUSIONS: Despite compensatory expression of antioxidants, high glucose-induced oxidative stress accelerates stress-induced senescence in rat notochordal cells. This may result in dysfunction of notochordal cells, leading to accelerated premature disc degeneration. The prevention of excessive generation of oxidative stress by strict blood glucose control is important to prevent or to delay premature disc degeneration in young patients with diabetes mellitus.
Aging* ; Animals ; Antioxidants ; Blood Glucose ; Catalase ; Cell Aging ; Cell Culture Techniques ; Diabetes Mellitus ; Glucose* ; Humans ; Intervertebral Disc Degeneration ; Membrane Potentials ; Notochord* ; Oxidative Stress ; Rats* ; Reactive Oxygen Species ; Superoxide Dismutase ; Telomerase

OBJECTIVETo investigate the associations between Epstein-Barr virus (EBV) and human cytomegalovirus (HCMV) infections and the methylation levels of PTEN and hTERT genes and explore their roles in children with acute lymphoblastic leukemia (ALL).

METHODSBlood samples from 100 children with newly diagnosed acute lymphoblastic leukemia were centrifuged for serological detection of EBV and HCMV, and the patients were divided accordingly into EBV-infected group (n=20), HCMV-infected group (n=14), EBV and HCMV co-infected group (n=41), and non-infected group (control group, n=15). DNA was extracted from peripheral blood mononuclear cells (PBMCs) and modified with bisulfite ammonia sodium. The methylation levels of the promoters of PTEN and hTERT genes were detected with methylation-specific polymerase chain reaction (MS-PCR).

RESULTSCompared with those in non-infected group and EBV- or HCMV-infected group, the methylation levels of PTEN gene in the co-infected group were significantly decreased (P<0.05) while the methylation levels of hTERT gene significantly increased (P<0.05).

CONCLUSIONIn children with acute lymphoblastic leukemia, EBV and HCMV co-infection cause changes in the methylation levels of PTEN and hTERT. These results may be associated with epigenetic changes caused by viral infections, and further studies are needed to further verify this hypothesis.

Child ; Coinfection ; Cytomegalovirus ; isolation & purification ; Cytomegalovirus Infections ; DNA Methylation ; Epstein-Barr Virus Infections ; Herpesvirus 4, Human ; isolation & purification ; Humans ; PTEN Phosphohydrolase ; genetics ; metabolism ; Precursor Cell Lymphoblastic Leukemia-Lymphoma ; blood ; genetics ; virology ; Promoter Regions, Genetic ; Telomerase ; genetics ; metabolism

The present study was aimed to investigate the effect of different altitudes on telomere length of rat peripheral blood leukocyte and possible mechanism. Sixty male rats were randomly divided into three groups, lower altitude control group (10 m), moderate altitude group (2 260 m) and very high altitude group (simulated 5 000 m). The moderate altitude group and very high altitude group rats were transported to Xining and hypobaric chamber in Qinghai University, respectively. The peripheral blood specimens were extracted 30 d after the transportation. By means of real-time PCR, automatic blood cell analyzer, ELISA, TBA and WST-1 methods, the telomere lengths of blood leukocyte, the hemoglobin (Hb) contents, the plasma levels of telomerase reverse transcriptase (TERT) and hypoxia-inducible factor 1α (HIF-1α), the plasma content of malondialdehyde (MDA) and superoxide dismutase (SOD) activity were measured, respectively. The results showed that the telomere lengths of peripheral blood leukocyte in moderate altitude group were longer than those in control group and very high altitude group. The changes of TERT were compatible with the telomere length of peripheral blood leukocyte under different altitudes. The levels of HIF-1α in moderate altitude group and very high altitude group were higher than that of control group. The very high altitude group showed decreased SOD activities and increased level of MDA, compared with the other two groups. These results suggest that the telomere lengths of rat peripheral blood leukocyte in moderate altitude are elongated, and that the telomere-elongating effect is lost under very high altitude. The changes of HIF-1α, TERT and oxidative stress damage are the main mechanisms of telomere length changes. Moderate altitude living might be beneficial to increasing the life span in mammals.
Altitude ; Animals ; Hemoglobins ; metabolism ; Hypoxia ; Hypoxia-Inducible Factor 1, alpha Subunit ; blood ; Leukocytes ; physiology ; Male ; Malondialdehyde ; blood ; Oxidative Stress ; Rats ; Superoxide Dismutase ; metabolism ; Telomerase ; blood ; Telomere ; physiology

Telomerase play a key role in the maintenance of telomere length and chromosome integrity. We have evaluated the association between telomerase activity and the risk of lung cancer in peripheral blood. Telomerase activity in peripheral blood mononuclear cells was measured by a PCR-designed telomeric repeat amplification protocol in 63 lung cancer patients and 190 healthy controls that were matched for age, gender, and smoking status. Telomerase activity was significantly lower in the lung cancer patients than in controls (mean +/- standard deviation; 1.32 +/- 1.65 vs 2.60 +/- 3.09, P < 1 x 10(-4)). When telomerase activity was categorized into quartiles based on telomerase activity in the controls, the risk of lung cancer increased as telomerase activity reduced (Ptrend = 1 x 10(-4)). Moreover, when the subjects were categorized based on the median value of telomerase activity, subjects with low telomerase activity were at a significantly increased risk of lung cancer compared to subjects with high telomerase activity (adjusted odds ratio = 3.05, 95% confidence interval = 1.60-5.82, P = 7 x 10-4). These findings suggest that telomerase activity may affect telomere maintenance, thereby contributing to susceptibility to lung cancer.
Age Factors ; Aged ; Case-Control Studies ; Female ; Humans ; Leukocytes, Mononuclear/enzymology/immunology ; Lung Neoplasms/*enzymology/*etiology ; Male ; Middle Aged ; Odds Ratio ; Risk Factors ; Sex Factors ; Smoking ; Telomerase/*blood

Cancer stem cells have stem cell-like features, such as the ability for self-renewal and differentiation but show unlimited growth because they have the lost normal regulation of cell growth. Cancer stem cells and normal stem cells have similar features. They show high motility, diversity of progeny, robust proliferative potential, association with blood vessels, immature expression profiles, nestin expression, epidermal growth factor (EGF)-receptor expression, phosphatase and tensin homolog (PTEN) expression, hedgehog pathway activity, telomerase activity, and Wnt pathway activity. On the other hand, with cancer cells, some of these signaling pathways are abnormally modified. In 1875, Cohnheim suggested the concept of cancer stem cells. Recently, evidence for the existence of cancer stem cells was identified. In 1994, the cancer stem cells'specific cell surface marker for leukemia was identified. Since then, other specific cell surface markers for cancer stem cells in solid tumors (e.g. breast and colon cancer) have been identified. In oral cancer, studies on cancer stem cells have been performed mainly with squamous cell carcinomas. Oral cancer specific cell surface markers, which are genes strongly expressed in oral cancer and cancer stem cell specific side populations, have been identified. Cancer stem cells are resistant to radiotherapy and chemotherapy. Therefore, to eliminate malignant tumors efficiently and reduce the recurrence rate, therapy targeting cancer stem cells needs to be performed. Currently, studies targeting the cancer stem cells'specific signaling pathways, telomerase and tumor vasculatures are being done.
Antigens, Surface ; Blood Vessels ; Breast ; Carcinoma, Squamous Cell ; Colon ; Epidermal Growth Factor ; Hand ; Hedgehogs ; Intermediate Filament Proteins ; Leukemia ; Microfilament Proteins ; Mouth Neoplasms ; Neoplastic Stem Cells ; Nerve Tissue Proteins ; Recurrence ; Signal Transduction ; Stem Cells ; Telomerase ; Wnt Signaling Pathway

OBJECTIVETo study the effect of C21 steroidal glycoside (CSG) from the root of Cynanchum auriculatum from Jiangsu on D-galactose (D-gal) induced aging model mice.

METHODD-gal aging mouse model was established by cervicodorsal region subcutaneous injection with D-gal once a day for eight successive weeks. The mice in the normal control group (NCG, non-modeled) and the model control group (MCG, modeled but untreated) were treated with 1% CMC-Na. The model mice in the low, middle and high-dose CSG and Vitamin E treated groups were treated with a dose of (10, 20, 40, 100 mg x kg(-1) per day, respectively. The SOD activity, MDA content and telomerase activity in serum, heart, liver and brain tissues of mice were measured.

RESULTCSG could obviously increase the SOD activity and decrease the MDA level in serum, heart, liver and brain tissues in D-gal aging mice (P < 0.01). There was no significant difference between three CSG treated groups and Vitamin E treated groups. In comparison of telomerase activity between MCG and the treated groups, it was shown that there was a significant increase in serum in middle and high dose group, and in heart tissues in CSG and Vit E treated groups, but was not in liver and brain tissue.

CONCLUSIONThis study demonstrates that CSG can antagonize free radical injury, increase the SOD activity and decrease the MDA content of serum, heart, liver and brain in D-gal aging mice, and increase the telomerase activity in serum and heart tissues but not in liver and brain tissue.

Aging ; drug effects ; metabolism ; Animals ; Brain ; drug effects ; metabolism ; Cynanchum ; chemistry ; Drugs, Chinese Herbal ; isolation & purification ; pharmacology ; Female ; Galactose ; toxicity ; Glycosides ; isolation & purification ; pharmacology ; Liver ; drug effects ; metabolism ; Male ; Malondialdehyde ; blood ; metabolism ; Mice ; Mice, Inbred ICR ; Myocardium ; metabolism ; Plant Roots ; chemistry ; Plants, Medicinal ; chemistry ; Random Allocation ; Steroids ; isolation & purification ; pharmacology ; Superoxide Dismutase ; blood ; metabolism ; Telomerase ; metabolism

Adolescent ; Adult ; Aged ; Antigens, CD ; biosynthesis ; Brain Neoplasms ; blood supply ; metabolism ; pathology ; Child ; Endoglin ; Female ; Glioma ; blood supply ; metabolism ; pathology ; Humans ; Hypoxia-Inducible Factor 1, alpha Subunit ; biosynthesis ; Immunohistochemistry ; Male ; Middle Aged ; Neovascularization, Pathologic ; metabolism ; pathology ; Receptors, Cell Surface ; biosynthesis ; Telomerase ; biosynthesis ; Young Adult

BACKGROUND: Background Telomerase activation and human telomerase RNA (hTR) expression are known to be related to the preservation of the "stemness" of stem cells. In this study, we have inhibited the expression of hTR to find the relationship between the telomerase activity and differentiation of normal hematopoietic stem cells. METHODS: We used cord blood collected from 10 full term pregnant women. We classified the CD34+ hematopoietic stem cells from the same donor into three groups: the Ad-OA group was treated with the recombinant adenoviral (Ad) vector Ad-OA using telomerase antisense, the Ad-M6 group was treated with a mutant version of the Ad-OA without telomerase antisense, and a control group without any treatment. RESULTS: The mean number of colony-forming cells (CFCs) were 110+/-38 for the Ad-OA groups, 540+/-56 for the Ad-M6 groups, and 650+/-72 for the control groups. Thus, CFCs in the Ad-OA group were lower than in the Ad-M6 group (P<0.01). The myeloid portion of the CFCs in the Ad-OA group was higher than the Ad-M6 and control groups (P<0.01). The Ad-OA group showed a higher percentage of granulocytes suggesting more of a tendency for myeloid differentiation than the Ad-M6 and control groups (P<0.01). We found that the suppression of telomerase activity by the antisense telomerase adenovirus induced the differentiation of hematopoietic stem cells confirmed by differential cell count and cytochemical staining. CONCLUSION: These findings suggest that the activity of the telomerase may play a role in the differentiation of normal CD34+ hematopoietic stem cells into mature cells.
Adenoviridae ; Cell Count ; Female ; Fetal Blood ; Granulocytes ; Hematopoietic Stem Cells ; Humans* ; Pregnant Women ; RNA* ; Stem Cells ; Telomerase* ; Tissue Donors

To investigate the expression of hTERT mRNA in bone marrow mononuclear cells (MNCs) from acute leukemia patients, the method of semi-quntitative RT-PCR was used to examine the expression of hTERT mRNA in marrow MNCs, and the telomerase activity of marrow MNCs was determined with the method of TRAP-PCR-ELISA by using a commercial kit. The results indicated that the expression of hTERT mRNA of marrow MNCs in 30 untreated AL patients was markedly higher than that in 12 CR cases (0.71 +/- 0.34 vs 0.43 +/- 0.25, P < 0.05) and 6 normal volunteers (0.71 +/- 0.34 vs 0.22 +/- 0.21, P < 0.01), respectively. Telomerase activity of marrow MNCs in 30 untreated AL patients was significantly higher than that in 12 CR cases (0.235 +/- 0.395 vs 0.012 +/- 0.015, P = 0.007). Moreover, there was a positive correlation between the hTERT mRNA synthesis and telomerase activity in AL cells (r = 0.421, P < 0.01). The pencentage of blast cells in marrow smear of the untreated AL patients was positively correlated with both the expression of hTERT mRNA and the telomerase activity of bone marrow MNCs (r = 0.457, P < 0.05 and r = 0.411, P < 0.05), respectively. It is concluded that the expression of hTERT mRNA in bone marrow MNCs from untreated AL patients was correlated with their telomerase activity. It is suggested that the expression of hTERT mRNA leukemic cells indicates their higher proliferation ability.
Acute Disease ; Bone Marrow Cells ; enzymology ; DNA-Binding Proteins ; Enzyme-Linked Immunosorbent Assay ; Gene Expression Regulation, Enzymologic ; Gene Expression Regulation, Neoplastic ; Humans ; Leukemia ; enzymology ; genetics ; pathology ; Leukocytes, Mononuclear ; enzymology ; RNA, Messenger ; genetics ; metabolism ; Reverse Transcriptase Polymerase Chain Reaction ; Telomerase ; blood ; genetics