Telomerase activity in skeletal sarcomas

Background: Telomerase is a ribonucleoprotein that adds TTAGGG nucleotide repeats onto the ends of eukaryotic chromosomes to maintain telomere integrity. Somatic cells do not express telomerase and stop dividing when the chromosomal ends are shortened critically after many cell divisions. Immortal cell lines and cancer cells apparently have telomerase activity that contributes to an unlimited number of cell cycles. The purpose of our study is to investigate whether telomerase activity is expressed in primary malignant tumors of the skeletal system when compared to adjacent normal tissue. Methods: Fresh tumor and normal tissue was collected from 14 patients (10 males, 4 females; age range, 8 to 76 years) and protein extraction performed. The tumors included seven osteosarcomas (three examined before and after chemotherapy), two chondrosarcomas, two spindle cell tumors, one hemangiopericytoma, one chordoma, and one adamantinoma. Telomerase activity was analyzed by using a highly sensitive polymerase chain reaction (PCR)-based assay (telomere repeat amplification protocol [TRAP]). Results: Telomerase activity was found in 8 of 14 sarcoma patients (57%) using the TRAP assay. Compared to HeLa cell extract (positive control), telomerase activity in the tumor specimen ranged from 0 (in osteosarcoma) to 11.7% (in hemangiopericytoma). There was variation in the number of telomeric repeats generated by telomerase. At least five telomeric bands (e.g. 50, 56, 62, 68, 74 bp) in a ladder pattern had to be present before telomerase activity was considered positive in our analysis. Conclusions: Telomerase activity may be an oncogenic sustaining event helping to maintain the transformed phenotype seen in malignant tumors of the bone. The degree of telomerase activity varies among skeletal malignancies, but was less than that observed in HeLa cells. The majority of osteosarcomas showed no telomerase activity.     

乳腺癌端粒长度与端粒酶活性变化的相关性研究

目的　检测乳腺癌及其癌旁组织中的端粒 (TLM )长度、端粒酶 (TLMA )活性的表达 ,探讨乳腺癌端粒长度与端粒酶活性的关系。方法　采用端粒酶重复扩增实验 (TRAP) 银染法检测端粒酶活性 ,以地高辛标记的Southern杂交的方法检测端粒长度。结果　端粒酶活性在乳腺癌TNM分期的进展中由Ⅰ期的 5 9.1%增高到Ⅳ期的 92 .9% ,而端粒长度在乳腺癌TNM分期的进展中不断缩短 ,由Ⅰ期的 (7.5 4± 0 .95 )kb缩短到Ⅳ期的 (5 .0 3± 0 .5 3 )kb。恶性乳腺肿瘤癌旁组织中的平均端粒长度皆位于正常水平。乳腺癌中端粒酶阳性表达组的端粒长度为 (4 .45± 1.3 9)kb显著短于端粒酶阴性组的 (5 .70± 1.2 3 )kb。结论　恶性乳腺肿瘤将端粒酶激活并没有绝对延长其染色体末端的端粒长度 ,而且 ,随着肿瘤的发展端粒片段还会缩短 ,并与端粒酶活性似乎存在着反向的关系。     

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目的 探讨乳腺肿块细针穿刺端粒酶活性检测在乳腺癌术前诊断中的临床应用价值。方法 对８５例乳腺肿块病人者细针穿刺,对穿刺细胞分别用端粒重复扩增法（ＴＲＡＰ）进行端粒酶活履检测和光镜细胞检查。以术后石蜡病理切片结果最地两种检测方法在术前诊断乳腺癌方面的灵敏度、特异性和约登指数进行了比较。结果 术前端粒酶活性检测同穿刺细胞学相比,特异性分别为７３．９％和８２．６％（Ｐ〉０．０５）,差异无显著性;灵敏度分     

细针穿刺端粒酶活性检测在乳腺癌术前诊断中的临床应用研究

目的 探讨乳腺肿块细针穿刺端粒酶活性检测在乳癌术前诊断中的临床应用价值,为应用于临床提供科学依据.方法 对85例乳腺肿块病人进行细针穿刺,对穿刺细胞分别用端粒重复扩增法(TRAP)进行端粒酶活性检测和光镜细胞学检查.以术后石蜡病理切片结果为最终标准,分别对两种检测方法在术前诊断乳癌方面的灵敏度、特异性和约登指数进行了比较.结果 术前端粒酶活性检测同穿刺细胞学相比,特异性分别为73.9%和82.6%(P>0.05),灵敏度分别为91.9%和64.5%(P<0.05),约登指数分别为65.8%和47.1%(P<0.05).结论 乳腺肿块穿刺端粒酶活性检测在乳癌术前诊断中具有较大的应用价值.     

膀胱癌癌旁组织端粒酶活性检测的临床意义

目的　探讨膀胱癌癌旁组织端粒酶活性检测的临床意义。　方法　采用端粒重复序列扩增 (TRAP)法 ,检测 2 4例膀胱癌组织及癌旁组织中端粒酶活性表达。　结果　 2 4例癌旁组织中端粒酶活性表达阳性 10例 (42 % ) ,癌旁组织端粒酶活性表达与原发灶癌病理分级分期相关 ,并与癌复发相关。　结论　膀胱癌癌旁组织端粒酶活性检测可作为判断膀胱癌预后的指标之一     

膀胱癌尿脱落细胞端粒酶活性检测及其临床意义

目的检测尿脱落细胞端粒酶活性并探讨其临床意义。方法应用改良的端粒重复序列扩增（ＴＲＡＰ）银染方法,分别对膀胱癌组织、正常膀胱组织,以及膀胱癌患者和非尿路上皮肿瘤患者的尿脱落细胞、膀胱冲洗液进行端粒酶活性检测。结果１２例正常膀胱组织均无端粒酶活性,４８例膀胱癌组织中４４例（９１．７％）端粒酶阳性。膀胱癌患者尿液及膀胱冲洗液中脱落细胞端粒酶阳性率分别为８３．３％（４０／４８）和８７．５％（４２／４８）。１２例分化良好（Ｇ１级）膀胱癌患者中,尿液和膀胱冲洗液中脱落细胞端粒酶阳性率分别为７５．０％（９／１２）和８３．３％（１０／１２）。结论尿脱落细胞端粒酶活性检测敏感性高,可用于膀胱癌的早期诊断和术后随访。     

FOCAL INTRATUMORAL HETEROGENEITY FOR TELOMERASE ACTIVITY IN HUMAN PROSTATE CANCER

PURPOSE: The value of telomerase activity as a marker in clinical decision-making is closely related to how representative the analysis of a small tumor sample is for the whole tumor. We therefore evaluated the intratumoral distribution pattern of telomerase activity in prostatic carcinomas. MATERIALS AND METHODS: From 50 prostate cancer patients treated with radical prostatectomy, telomerase activity was determined using the telomeric repeat amplification protocol (TRAP assay). Comparative analysis of at least two separate cancer areas from a single tumor was performed in 42 cases. RESULTS: Telomerase activation has been demonstrated in 90% of the prostatic carcinomas. Focal intratumoral heterogeneity was found in 38.1% of the tumors with at least two different areas examined. Telomerase positivity of all samples from one given tumor was detected in 50%, telomerase negativity of all samples in 11.9%. A heterogeneous telomerase activity pattern was more frequently detected in tumors with a Gleason score < or = 7 than in those with a Gleason score > 7. Furthermore, there was an increase in the proportion of homogeneously telomerase-positive tumors with increase in severity of the Gleason score. The differences reached statistical significance. Telomerase activity was also detected in non-cancerous prostatic tissue samples. CONCLUSIONS: Telomerase activation is nearly ubiquitous in prostatic carcinomas, although a heterogeneous telomerase activity pattern within tumors might produce a false-negative result in the telomerase activity assay. This limits the value of telomerase activity assays for diagnostic means. There is evidence for a shift from telomerase-negative prostate cancer tissue toward telomerase positivity during the progression process of prostate cancer. The relatively high proportion of telomerase-positive nonmalignant prostatic tissue samples argues against cancer-specificity of telomerase activation.     

前列腺穿刺活检组织端粒酶活性检测及其临床意义

通过检测国人前列腺穿刺活检组织端粒酶活性,探讨其在前列腺癌诊断和预后的临床意义。20例前列腺癌标本和16例癌旁组织均来自前列腺穿刺活检,14例良性前列腺增生(BPH)标本取自前列腺摘除手术,均经病理证实。采用改良的TRAP-银染方法检测端粒酶活性,并进行半定量分析。结果20份前列腺癌标本中18份测得端粒酶活性(90％)。在16例癌旁前列腺组织中,64％(7/11)的前列腺上皮肉瘤(PIN)及40％(2/5)的癌旁BPH组织有端粒酶活性表达。14例BPH标本端粒酶活性均为阴性。18例前列腺癌阳性标本的端粒酶活性强度与肿瘤分级分期及PSA水平呈正相关。前列腺穿刺活检组织端粒酶活性检测可作为前列腺癌诊断的一项敏感性指标,其在前列腺癌预后中的价值有待于进一步的研究。     

Telomerase activity in touch-imprint cell preparations from fresh prostate needle biopsy specimens.

OBJECTIVE: To evaluate whether it is possible to detect telomerase activity in cells exfoliated from prostate biopsies immediately before fixation. METHODS: A total of 115 transrectal biopsies of prostate tissue from 49 patients were touch-imprinted on an RNase-free microscope slide and then fixed. Touch imprints were immediately frozen and used to extract telomerase. Telomerase activity was determined by a telomeric repeat amplification protocol (TRAP) using a PCR-ELISA method. Inflammation and epithelial cells in each biopsy were quantitated by image cytometry. RESULTS: A total of 90/115 extracts had a proteic content suitable for analysis. Telomerase activity was detected in 18/26 (70%) carcinomas, 2/9 (22%) low-grade prostatic intraepithelial neoplasia (PIN) lesions, and 1/3 (33%) high-grade PIN lesions. In 4 of 7 patients with telomerase-positive tumors, telomerase activity was also found in a distant site devoid of morphologically detectable cancer cells. Telomerase activity was detected in touch imprints from fragments with less than 1 mm(2) of epithelial tissue, and was not associated with the extent of inflammation. CONCLUSIONS: From the technical stand point, the touch-imprint method may provide a useful adjunct for telomerase detection in prostate biopsies. With this procedure the bioptic fragment is left intact for histological examination. Diagnostically, the presence of telomerase activity in sites distant from the original tumor might suggest the presence of tumor cells that are morphologically undetectable.     

Telomerase Activity in Giant Cell Tumors of Bone

Background A giant cell tumor of bone (GCT) is a histologically benign neoplasma that has an unpredictable pattern of biological aggressiveness. In the present study, we investigated whether there was a correlation between telomere length or the levels of telomerase activity and other clinical features of GCTs, for the possible use of these factors as parameters of aggressiveness or prognosis. Methods In 16 surgically resected GCTs specimens, telomere length was assessed by terminal restriction fragments by Southern blot analysis. Telomerase activity was measured by a semiquantitative polymerase chain reaction–based telomeric repeat amplification protocol assay. Results Telomere length reduction was observed in 69% of the GCT samples. The telomere lengths of tumors were significantly shorter than those of normal tissue (P = .008). The mean telomere length of grade 3 tumors was significantly shorter than those of grade 1 and 2 tumors (P = .038). Telomerase activity was detected in 81% of tumor samples. The level of telomerase activity in tumors with local recurrence was significantly higher than in tumors without local recurrence (P = .011). Conclusions These results suggest that telomere length correlates with roentgenographic grade as a result of the frequency of cell division, and high telomerase activity indicates the aggressiveness of GCTs.     

Telomerase activity in malignant and benign renal tumors

OBJECTIVES: An important characteristic of malignant cells is their unlimited replicative potential, their immortality. In conferring this immortality, the enzyme telomerase is believed to play a crucial role. The detection of telomerase activity provides new knowledge regarding the biologic growth behavior of tumors and offers new diagnostic and therapeutic tools. METHODS: In the present study the sensitive TRAP assay (telomeric repeat amplification protocol) was used to examine 44 malignant renal tumors and 8 benign tumors of the kidney and 52 specimens of normal renal tissue for telomerase activity. RESULTS: Telomerase activity was detected in 63% of tissue samples obtained from histologically confirmed renal cell carcinomas. In cases of renal cell carcinoma restricted to the kidney, telomerase activity was detected in 58%. In cases in which tumor growth has progressed beyond the limits of the organ, telomerase activity was found in 69%. This stage dependence, however, did not reach statistical significance. No correlation to tumor grading was observed. Telomerase activity was found less frequent in chromophobe renal cell carcinomas. Neither the 8 benign renal tumors (4 oncocytomas and 4 angiomyolipomas) nor the specimens of normal kidney showed any evidence of telomerase activity. CONCLUSIONS: The proportion of remarkable slow-growing renal cell carcinomas showing telomerase activity is less than in other malignancies and may correlate with biologic growth behavior. Possible explanations include the presence of an alternative pathway, called ALT (alternative lengthening of telomeres) and an association with the loss or presence of the telomerase suppressor on the short arm of chromosome 3. Prolonged follow-up will be of special interest to determine whether lack of telomerase activity predicts favorable outcome.     

TRAP银染法检测端粒酶在胃癌组织中的表达

目的了解胃癌组织中端粒酶表达的状况及其临床意义,研究非放性 TRAP 检测端粒酶的可行性。方法用 TRAP 银染法检测58例胃癌及相应患者的正常胃粘膜,12例胃腺瘤和9例胃溃疡组织的端粒酶表达情况。结果 58例胃癌组织中49(84.5％)例端粒酶表达阳性,正常粘膜无一例检测到端粒酶活性(P<0.001),12例胃腺瘤,9例胃溃疡组织中各有1例检测到端粒酶活性。胃癌组织端粒酶的表达与年龄、肿瘤大小、分化程度、浸润深度、淋巴结转移及 TNM 分期等临床病理参数无明显相关(P<0.05)。结论端粒酶是一种较理想的胃癌肿瘤标记物,TRAP 银染法是一种值得推广的检测端粒酶活性的方法。     

胃癌与端粒酶活性表达及DNA倍体关系的研究

目的　揭示胃癌与端粒酶活性及DNA倍体的关系。方法　检测 30例胃癌标本 ,同时取无瘤残端作为对照。端粒酶检测采用端粒重复扩增 酶联免疫吸附法 (TRAP ELISA法 )。DNA倍体的测定采用流式细胞术 ,一步法检测DNA含量。结果　肿瘤瘤体端粒酶阳性率 83 3% (2 5 / 30 ) ,无瘤残端端粒酶阳性率 3 3%(1/ 30 ) (P <0 .0 5 ) ;端粒酶阳性瘤体平均直径 6 5cm ,阴性瘤体平均直径 3 6cm(P <0 .0 5 ) ;端粒酶阳性肿瘤淋巴转移率 5 3 3% (16 / 30 ) ,阴性者无淋巴转移 (0 / 5 ) (P <0 .0 5 ) ;端粒酶阳性肿瘤中异倍体肿瘤占 5 6 0 % (14/2 5 ) ,而端粒酶阴性者无异倍体出现 (P <0 .0 5 )。结论　胃癌端粒酶活性升高 ,端粒酶阳性肿瘤瘤体大 ,淋巴转移率高 ,且异倍体发生率高 ,预后差。提示端粒酶的激活与胃癌的发生发展有密切关系。     

Consistent decrease in telomere length in parathyroid tumors but alteration in telomerase activity limited to malignancies: preliminary report

Telomerase is known to be activated and telomere length altered in various types of malignant and benign tumors, but whether this is also the case for parathyroid lesions has hitherto been unclear. We therefore investigated telomerase activity and telomere length in 3 parathyroid metastatic cancers, 6 adenomas, 2 cases of parathyroid hyperplasia, and 16 samples of normal parathyroid tissue. Telomerase activity, assayed by the telomeric repeat amplification protocol, was detected in all of the parathyroid cancers (100%), in none of the 8 parathyroid benign lesions, and in only 1 of the 16 normal parathyroid samples (8.3%). Telomere length, determined by the terminal restriction fragment assay, was reduced in the tumor tissues with a mean telomere length of 8.23 +/- 0.86 kbp compared with the 12.61 +/- 0.81 kbp for the 16 age-matched subjects (p = 0.002). The results indicate that telomerase activity and telomere length may reflect the biologic behavior of individual parathyroid lesions.     

大肠癌肝转移肿瘤中端粒酶活性和p16基因纯合缺失

目的 研究人大肠癌肝转移肿瘤中端粒酶活性和p16基因纯合缺失及其临床意义。方法 采用TRAP银染方法和半定量多重PCR检测24例大肠癌转移肿瘤组织中端粒酶活性及p16基因的纯合缺失情况,并结合临床病理参数,进行统计学分析。结果 本组24例大肠癌肝转移肿瘤组织中检测到19例端粒酶阳性,阳性率为79．2％。端粒酶活性与转移瘤大小、肝内转移灶数目、分化程度、HBsAg以及是否伴有纤维化无关。在24例转移瘤组织中有9例标本中检测到p16基因的缺失,阳性率为37．5％,p16基因的失与端粒酶活性相关。结论 大肠癌肝转移肿瘤中端粒酶活性和p16基因异常对阐明大肠癌转移的生物学行为有重要的意义。     

The association between telomerase, histopathological parameters, and KI-67 expression in breast cancer.

BACKGROUND: Telomerase is a ribonucleoprotein enzyme that appears to play an important role in carcinogenesis. Telomerase reactivation seems to be associated with immortalization and malignancy. METHODS: Using a polymerase chain reaction (PCR)-based assay known as the TRAP (telomeric repeat and amplification protocol) assay, we examined telomerase activity in 60 breast specimens prospectively collected from 39 patients undergoing elective breast surgery in our center. The specimens included adjacent noncancerous breast (n = 21), benign breast disease (n = 5), and infiltrating carcinoma (n = 34). Ki-67 expression was determined in 32 invasive breast cancer specimens using immunohistochemistry techniques. The histopathological features were determined by light microscopy by an experienced breast pathologist. RESULTS: Telomerase activity was detected in 24 (71%) of 34 infiltrating carcinomas. None of the adjacent noncancerous specimens nor the benign breast lesions expressed telomerase activity. Telomerase reactivation was significantly associated with nodal metastasis and Ki-67 expression. There was no significant association between telomerase activity and menopausal status, tumor grade, or tumor size. CONCLUSIONS: Telomerase reactivation is associated with the acquisition of malignancy in the human breast. Telomerase activity is significantly associated with nodal metastasis and cellular proliferation as measured by Ki-67 expression in human breast cancer.     

端粒酶活性及其结构基因在人脑胶质瘤中的表达

目的 研究分析端粒酶活性及相关结构基因在不同级别脑胶质瘤中的表达,探讨端粒酶与脑胶质瘤的相关性及其临床意义。方法 采集40例脑胶质瘤手术切除标本、4例正常脑组织,通过半定量端粒重复序列扩增（TRAP）－银染方法检测端粒酶活性水平;通过半定量逆转录－聚合酶链反应（RT－PCR）检测端粒酶相关结构基因hTR、TP1、hTRT的 mRNA表达水平,结果 在40例胶质瘤标本的33例（82.5%)中检测出端粒酶活性,而在正常脑组织中无端粒酶活性的表达,不同级别脑胶质瘤之间端粒酶活性水平差异有显著性,脑胶质瘤粒酶活性水平与hTRT基因的表达呈显著正相关,而与TP1、hTR 的表达无显著相关。结论 端粒酶活性可以作为脑胶质瘤的恶性标记之一,hTRT基因是一个端粒酶的正调控结构基因,hTRT的表达与细胞永生化和恶性肿瘤形成过程中的端粒酶的激活机制有关,hTR基因是端粒酶活性必须的组分,但不影响端粒酶活性的高低。     

Detection of telomerase activity in prostatic fluid specimens

We report here the extended use of the telomeric repeat amplification protocol (TRAP) assay for the detection of telomerase activity in fresh prostatic fluid obtained from anesthetized patients. Telomerase activity was detected in pellet extract and/or supernatant fluid of specimens obtained from 25 of 30 prostate cancer (PCa) patients (83%), whereas no activity was similarly detectable in specimens taken from 8 of 9 patients (89%) without clinical evidence of PCa. The positive predictive value (PPV) of the TRAP assay for PCa in this pilot study was 96%. We found a strong correlation between telomerase activity in prostatic fluid specimens and serum prostate specific antigen (PSA) values. Telomerase activity was found in 84% of specimens from patients with PSA values >4 ng/ml, whereas in specimens from patients with PSA values 4. In prostatic fluid from PCa patients with Gleason scores of 相似文献