【Abstract】Objective To explore the relation between the expression of telomerase and DNA ploidy with biliarypancreatic system cancer, so as to find a better way to diagnose and distinguish jaundice between malignance and benign disease.Methods Endoscopic retrograde cholangiopancreatography (ERCP) were performed before operation in patients with obstructive jaundice. The bile and pancreatice juice were collected before ERCP. Biopsy specimens from part of patients were obtained during ERCP. All cancer specimens were possessed once again during operation and were assessed by the activity of telomerase and DNA ploidy. Results ① Telomerase positive rate 〔87.50%(56/64)〕 of tissue specimens in malignant obstructive jaundice were higher than that in benign obstructive jaundice 〔3.33%(2/60)〕，P=0.000. ② Telomerase positive rate〔71.88%(46/64)〕of Bile and pancreatice juice in malignant obstructive jaundice were higher than that in benign obstructive jaundice 〔3.33%(2/60)〕， P=0.000, tissue specimens obtained by endoscopy with malignant obstructive jaundice had detectable telomerase activity, positive rate was 83.33%（20/24）. ③ The rate of DNA heteroploid with malignant obstructive jaundice was 62.50%（40/64）, that of diploid can be seen in all patients with benign obstructive jaundice, the difference was statistically significant (P=0.000). ④ The rate of telomerase positive and DNA heteroploid in high differentiation tumor were significantly lower than in middlelow differentiation tumor （P=0.028，P=0.001）.Conclusion Applying the duodenoscope we collected the bile and pancreatic fluid before operation and obtain biopsy specimens whose telomerase activity and DNA ploid were detected. This is simple, safe, quick method which can identify the malignant and benign obstructive jaundice.
Objective To investigate the effect of the 8-bromum-cyclic adenosine monophosphate (8-Br-cAMP) on the telomerase activity and changes of cell cycle in retinoblastoma （RB） cells. Methods The cultured RB cells were divided into the experimental group (8-Br-cAMP) and control group. After cultured for 24, 48 and 72 hours in vitro, the telomerase activity of RB cells was detected by polymerase chain reaction enzyme-linked immunosorbent assay (PCR-ELISA) and the changes of cell cycle were detected by flow-cytometry. Results The difference of telomerase activity was significant between the experimental groups and control group (Plt;0.01). There was a negative correlation between the A value of absorbance and the time in the experimental groups (r=-0.778 9, F=33.936, Plt;0.01). The changes of the cell cycle were that the percentages increased in G1 phase and decreased in S phases. Conclusion 8-Br-cAMP may weaken telomerase activity, affect the cell cycle, and inhibit the proliferation of RB cells. (Chin J Ocul Fundus Dis，2004，20：358-360)
OBJECTIVE: To prevent the senescence of ’seed cells’ for tissue engineering, the life span of human fibroblasts is extended by reconstitution of telomerase activity, and the osteogenic potential of these fibroblasts are tested. METHODS: The pGRN145 plasmids encoding human telomerase reverse transcriptase (hTERT) were introduced into the normal human primary fibroblasts by electroporation. Telomerase activity was analyzed by TRAP-PCR assay. The beta-galactosidase stain was used to indicate the signs of cell senescence. The hTERT positive fibroblasts were then induced to form bone nodules. The bone nodules were stained by tetracycline and Alizarin Red S. RESULTS: Stable telomerase activity could be detected in the transfected fibroblasts and no signs of cell senescence were found in the fibroblasts cultured for more than 50 doublings. The hTERT positive fibroblasts could form bone nodules when they were cultured in vitro induced by bone morphogentic protein 2 and tumor necrosis factor-alpha. CONCLUSION: The fibroblasts with reconstituted telomerase activity reserve their osteogenic potential.
OBJECTIVE: To analysis the proliferation properties and telomerase activity of human embryonic tendon cells transformed by ptsA58H plasmid cultured in vitro continuously. METHODS: The 40th, 70th, and 75th passages of transformed human embryonic tendon cells (THETC) were adopted. The collagen secretion of THETC was detected by immunohistochemical methods, the growth curve of different passages of THETC was compared, and chromosome karyotype was analyzed. Total RNA of THETC were extracted to detect human telomerase reverse transcriptase (hTERT) mRNA expression by RT-PCR technique. RESULTS: When THETC were subcultured to 70 passages, the morphological characteristics of cells changed and began replicative senescence. THETC still could secret type I collagen normally. The chromosome of THETC was heteroploid (2n = 94). There were no hTERT mRNA expression. CONCLUSION: SV40 transfection can not make human embryonic tendon cells immortalization, on the other hand, human embryonic tendon cells transformed by ptsA58H plasmid has no tendency of malignant transformation.
ObjectiveTo comprehensively analyze the recent advancements in the field of mesenchymal stem cells (MSCs) aging,and summary its achievements and its difficulty at the present. MethodsThe literature about MSCs aging was reviewed and analyzed. ResultsInducible telomerase reactivation of MSCs is successful to extend the life span of senescent cells,but it also has potential safety hazard.The age range presented in the research of age-related cell senescence is inconsistent,resulting in different outcomes.Many ways to improve cell in vitro culture conditions will help delay aging.Recent research indicates that oxidative stress theory is seemed to not completely explain cell aging. ConclusionFurther research of MSCs aging mechanism will help the tissue engineering transform to clinical application.
Objective To investigate the variety of telomerase activity in the course of liver cancer development, and the possibility of using telomerase as a marker of HCC. Methods Human liver specimens, comprising 22 HCC and adjacent peritumoral tissues, 12 liver cirrhosistissues, 6 nodulat regenerative hyperplasia (NRH) tissues and 10 normal liver tissues, were examined for telomerase activity by TRAP assay based on PCR. Results Twenty of 22 HCC and 14 of 22 adjacent tissue specimens were positive for telomerase activity with a positive rate of 90.9% and 63.6% respectively. Ten of 12 liver cirrhosis tissues were positive with a positive rate of 83.3%. 5 of 6 NRH were positive with a positive rate of 83.3%. Telomerase activity was negative in 10 normal liver tissues. Conclusion Telomerase may occur in the progress of hepatocarcinogenesis. Telomerase can be used as a tumor marker of HCC.
ObjectiveTo investigate the expressions and clinical significance of human telomerase reverse transcriptase (hTERT) mRNA and γglutamyl transpeptidase mRNA-H (GGT mRNA-H) in the peripheral blood of small hepatocellular carcinoma (HCC) patients. MethodsThe expressions of hTERT mRNA and GGT mRNA-H were detected in the peripheral blood of thirty patients with small HCC by RT-PCR, eighteen patients with benign liver diseases, and twelve normal volunteers. ResultsThe positive rate of hTERT mRNA and GGT mRNA-H expression in patients with small HCC were 80.0% (24/30) and 46.7%(14/30), respectively. In patients with hepatitic cirrhosis the positive rate of hTERT mRNA expression was 33.3% (6/18), while the expression of GGT mRNA was not detected. Both the expressions of hTERT mRNA and GGT mRNA-H were negative in all normal volunteers. The combination analysis of hTERT mRNA and GGT mRNA-H expression achieved positive rate of 86.7% in the diagnosis of small HCC, which was significantly higher than the positive rate of AFP (26.7%)， Plt;0.05. ConclusionThe hTERT mRNA and GGT mRNA-H are significantly expressed in small HCC patients, the combination analysis of hTERT mRNA and GGT mRNA-H seems to be useful in the early diagnosis of small HCC.
OBJECTIVE: To construct a plasmid which has a reporter gene for exploring the role of human telomerase reverse transcriptase(hTRT) in in-vitro cell cultivation. METHODS: hTRT was cut by restricted enzyme from plasmid pGRN145 and inserted to plasmid pEGFP-C1 (enhanced green fluorescent protein). RESULTS: Restricted enzyme analysis and DNA sequencing showed that the sequence of the pEGFP -hTRT transgenic plasmid was correct. CONCLUSION: The recombinant vector pEGFP-hTRT has been successfully constructed, and it can be used as a transgenic plasmid in generating immortalized cell lines.
【摘要】 目的 探讨宫颈上皮内瘤变（CIN）和宫颈鳞癌（SCC）组织中人类染色体端粒酶基因（hTERC）的表达和临床意义。 方法 收集2007年10月-2009年6月经病理学证实的116例宫颈脱落细胞标本，其中LSIL（CINⅠ）30例、HSIL（CINⅡ/Ⅲ）37例、SCC 16例、宫颈炎33例，用荧光原位杂交（FISH）方法检测脱落细胞hTERC基因。 结果 在宫颈炎、LSIL、HSIL和SCC组中hTERC基因的表达率分别是6.1%、16.7%、51.4%和93.8%，其中，HSIL、SCC组与宫颈炎组比较，hTERC基因阳性率差异有统计学意义（Plt;0.05），LSIL组与HSIL组比较、LSIL组与SCC组比较、HSIL组与SCC组比较，差异有统计学意义（Plt;0.05），且随着病变程度增加，hTERC基因表达率增加。 结论 hTERC基因在细胞学LSIL、HSIL和SCC中表达异常，且随病变程度增加阳性表达率也增加，可作为宫颈癌癌前病变进展的生物遗传学监测指标，并有望成为宫颈癌早期筛查方法之一。【Abstract】 Objective To explore the clinical significance and expression of the human telomerase gene (hTERC) in the cervical intraepithelial neoplasia (CIN) and squamous carcinoma of the cervix (SCC). Methods According to histological biopsy from October 2007 to June 2009, 116 pap smears were divided into LSIL (n=30), HSIL (n=37), SCC (n=16), and cervicitis (n=33) groups. Fluorescence in situ hybridization (FISH) was used to detect the expression of hTERC. Results Positive expression rate of hTERC was 6.1% in cervicitis group, 16.7% in LSIL group, 51.4% in HSIL group, and 93.8% in SCC group, respectively. Compared to cervicitis group, the expression of hTERC in HSIL and SCC groups was significantly higher (Plt;0.05). Among LSIL, HSIL, and SCC groups, there were significant differencec in hTERC expression between every two groups (Plt;0.05). From LSIL to SCC, the expression of hTERC increased obviously. Conclusion Abnormal expression of hTERC exists in LSIL, HSIL, and SCC patients, which significantly increases during malignant development. It may be a biogenetics monitor index of cervical precancerosis and will be a screening marker for cervical cancer.
【Abstract】Objective To study the difference of telomerase activity in the common thyroid lesions . Methods The telomerase activity was detected in 19 patients with thyroid carcinomas, 15 samples adjacent to thyroid carcinomas，21 specimens of thyromas, 17 cases of nodular goiters and 13 pieces of normal thyroid tissues by telomeric repeat amplification protocol（TRAP). Results Eighteen of 19 samples of thyroid carcinoma, 1 of 15 samples adjacent to the cancer and 1 of 21 adenoma of the thyroid specimens showed positive telomerase activity, all 17 cases of nodular goiters and 18 samples of normal thyroid tissues exhibited negative telomerase activity, and the rate of positive telomerase activity of thyroid carcinomas was significantly higher than that of the other tissues (P＜0.0001). Conclusion The telomerase is an important qualitative marker of thyroid carcinoma and a useful index in differential diagnosis of thyroid lesions.