Epidemiology and prognostic factors in malignant melanoma.

The rising rate of MM reflects damage to the skin that has been done in the past. If a difference is to be seen prospectively, we must use protection (sunscreens) and have suspicious areas evaluated early in their course so that MM can be treated when curable. Until further research yields a cure for advanced MM, the above approach remains the first line of defense in the fight against this cancer.     

Telomerase activity in adrenal cortical tumors and pheochromocytomas with reference to clinicopathologic features

Telomeres consist of short repeated sequences that are shortened on continuous cell proliferations and synthesized by telomerase, an RNA-dependent DNA polymerase. Recent molecular studies have reported that telomerase is activated in most human cancers, whereas it is not detected in most somatic cells. These findings indicate that the positive telomerase activity is closely related to the malignant potential of human tumors. In several types of human tumors, including adrenal cortical tumors and pheochromocytomas, it is very difficult to predict the malignant potential using conventional histopathologic examination. To determine whether telomerase activity is useful as a diagnostic marker, we examined telomerase activity in adrenal cortical tumors and pheochromocytomas with special reference to their clinicopathologic features. Using a highly sensitive polymerase chain reaction (PCR)-based detection method, telomerase activity was demonstrated in one of 13 adrenal cortical tumors and two of seven pheochromocytomas, whereas all seven normal portions of adrenal gland failed to showed any telomerase activity. Although none of the tumors examined in this study was associated with metastasis, these three telomerase-positive tumors were accompanied by clinicopathologic features suggesting malignant potential. Telomerase activity might be a potential marker for estimating the biologic characteristics of adrenal cortical tumors and pheochromocytomas. Received: 8 August 1997 / Accepted: 31 July 1997     

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.     

胰腺癌组织中端粒酶活性的表达

目的　探讨端粒酶活性与胰腺癌之间的关系 ,评价其作为胰腺癌诊断新的肿瘤标志物的可能性。方法　采用重复片段扩增SYBRGreen染色法 ,对 42例胰腺癌癌患者癌组织及其癌旁组织的端粒酶活性进行检测。结果　胰腺癌组织中端粒酶阳性率为 80 .9% (3 4/4 2 ) ,而在癌旁组织中仅 7.1% (3 /4 2 )表达端粒酶活性 ,胰腺癌组织端粒酶活性显著高于癌旁组织 (P <0 .0 0 1)。端粒酶活性的表达与胰腺癌组织的肿瘤大小、淋巴结转移、病理学临床分期及分化程度相关。结论端粒酶活性是特异性较强的恶性肿瘤分子标志物 ,其检测有可能成为胰腺癌诊断和预后判断的有效指标     

膀胱癌端粒酶活性的研究

目的 :探讨端粒酶活性和膀胱癌之间的关系。方法 :采用在PCR基础上建立的TRAP ELISA法对30例膀胱癌及 9例切缘组织和 7例正常膀胱组织中端粒酶活性进行半定量的研究。结果 :膀胱癌组总阳性率为83.3% (2 5 / 30 ) ,与切缘组 11.1% (1/ 9)和对照组 0 .0 % (0 / 7)相比差异有极显著性意义 (P <0 .0 1) ;后两者之间差异无显著性意义 (P >0 .0 5 )。端粒酶阳性表达率和表达强度与患者年龄、性别、病变部位、肿瘤大小、手术方式等无显著性相关 (P >0 .0 5 ) ,而端粒酶表达强度与细胞病理分级具有相关性 (P <0 .0 5 )。结论 :膀胱肿瘤的端粒长度和端粒酶活性对于判断疾病的恶性程度、预后、监测微小残瘤病灶和预示早期复发均有积极的意义     

膀胱癌组织端粒酶活性的研究

目的　探讨膀胱癌组织端粒酶活性的临床意义。　方法　应用银染端粒重复序列扩增法检测 42例膀胱癌及其癌旁组织的端粒酶活性。　结果　 3例正常膀胱组织端粒酶表达均阴性 ;42例膀胱癌组织中端粒酶表达阳性 35例 (83 .3 % ) ,癌旁组织端粒酶表达阳性 7例 (16 .7% ) ;浸润癌或有淋巴结或远处转移者端粒酶表达阳性率高于非浸润癌或无转移者 ,但差别无显著性意义 (P >0 .0 5 )。　结论　端粒酶是膀胱癌较理想的肿瘤标记物之一。     

Interobserver reproducibility of histopathologic prognostic variables in primary cutaneous melanomas

BACKGROUND: The prognosis for patients with localized primary cutaneous melanoma is known to depend principally on tumor thickness, and to a lesser extent on ulcerative state and Clark level. We have recently found in an analysis of 3661 patients that tumor mitotic rate (TMR) is also an important prognostic parameter, ranking second only to tumor thickness. However, few studies have assessed the accuracy and reproducibility with which these features of a melanoma are recorded by histopathologists. AIM: To assess interobserver reproducibility of major pathologic prognostic parameters in cutaneous melanoma. METHODS: Single hematoxylin and eosin-stained slides of 69 dermally invasive primary cutaneous melanomas were circulated among six pathologists with differing experience in the assessment of melanocytic tumors. The observers independently determined the tumor thickness, Clark level of invasion, ulcerative state, and TMR for each lesion. Intraclass correlation coefficients and kappa scores for multiple ratings per subject were calculated. RESULTS: The intraclass correlation coefficients were 0.96 for tumor thickness and 0.76 for TMR. The kappa scores were 0.83 for ulcerative state and 0.60 for Clark level. These results indicated excellent agreement among the pathologists for measurements of tumor thickness, ulcerative state, and TMR and fair to good agreement for Clark level. CONCLUSIONS: Appropriately trained and experienced histopathologists can assess prognostically important features of melanomas accurately and reproducibly. Given our recent finding of the significance of TMR in determining prognosis, it is important that this feature be assessed by a standardized method and documented for all primary cutaneous melanomas.     

Assessment of biopsy techniques and histopathologic interpretations of primary cutaneous malignant melanoma.

The biopsy techniques utilized for diagnosis in 1,161 patients with primary cutaneous malignant melanoma treated at the New York University Medical Center were reviewed. Eight hundred sixty-four (74%) biopsies were of the excisional type and 269 (23%) were incisional. Twenty-eight biopsies (3%) could not be assessed. Two hundred fifty-two consecutive patients referred for treatment of malignant melanoma to the authors for the last three years were studied to determine whether standard techniques of biopsy and uniform criteria for histopathologic diagnosis and staging were being utilized. One hundred forty-nine of these patients (59%) had total excisional biopsies of their lesions and 103 (41%) had incisional biopsies. Of the latter group, 66 (64%) were for lesions less than 2 cm in diameter and were situated in areas other than the face. The biopsy specimens obtained from 123 patients were reviewed by at least one other pathologist as well as our own (A.B.A.). For these 123 patients a difference of histologic diagnosis between pathologists occurred in 11 (9%). In 58 (47%) there was a discrepancy in assignment of Clark levels or a failure to assess Clark levels. Tumor thicknesses as measured by Breslow were read in only 22 (18%) of these 123 patients. The inadequacies of many of the biopsy specimens and discrepancies in histopathologic interpretation indicate that acceptable biopsy techniques and reproducible diagnostic criteria have not yet been generally adapted for primary cutaneous malignant melanomas.     

肾癌组织的端粒酶活性

目的探讨端粒酶活性与肾细胞癌之间的关系。方法采用改良ＴＲＡＰ法对３２例肾细胞癌组织及正常肾组织和可疑癌旁组织中端粒酶活性进行检测,同时了解其与临床生物学特征的关系。结果３２例肾细胞癌组织中端粒酶强阳性１７例,阳性１２例,阴性３例,阳性率９１％;３２例正常肾组织中端粒酶弱阳性者仅２例,阳性率６％;可疑癌旁组织阳性者６例,阳性率１９％。三组端粒酶活性比较,阳性率差异有显著性（Ｐ＜０．０１）。结论肾细胞癌组织中端粒酶活性检出率高,特异性强,无假阳性和假阴性。提示端粒酶活性检测可作为判断肾肿瘤恶性程度的标记物,并可能成为判断肾肿瘤预后的一项指标。     

Telomerase activity in the human breast

Telomerase is a ribonucleoprotein enzyme which appears to play an important role in carcinogenesis. Telomerase reactivation seems to be associated with immortalization and malignancy. Using a PCR-based assay, we examined telomerase activity in 50 breast tissue specimens, prospectively obtained from 37 women undergoing elective breast surgery. The specimens examined included normal breast (n=13), benign breast lesions (n=5), ductal carcinoma in situ (n=8) and infiltrating ductal carcinoma (n=24). All normal breast, benign breast and DCIS specimens lacked telomerase activity. Sixteen (67%) of 24 infiltrating carcinomas. In infiltrating ductal cancer, there was a statistically significant association between telomerase activity and nodal metastasis. The present results indicate that telomerase activity is associated with acquisition of invasive malignancy in the human breast and may have a role in complementing cytopathological diagnosis. Telomerase activity as a prognostic marker should be included in future validation studies. In DCIS, telomerase activity may be a late event associated with invasion of the basement membrane.     

Telomerase activity in rat liver allografts

BACKGROUND: Telomerase activity in grafts may be involved in the alteration of cellular senescence after transplantation or its relevant immunological events. METHODS: At the age of 20 weeks, donor livers harvested from DA (RT1a) were orthotopically transplanted into PVG (RT1c) or LEW (RT1(1)) rats. Rats having undergone orthotopic liver transplantation (OLT; DA-PVG) naturally overcome rejection, whereas all OLT (DA-LEW) rats die from acute rejection within 14 days. Telomerase activity in liver allografts was measured at various intervals post OLT. RESULTS: At day 7 when the most severe rejection episode was observed in OLT (DA-LEW) and OLT (DA-PVG), the telomerase activity was significantly higher than in syngeneic OLT (DA-DA) rats, in which no rejection occurred. Telomerase activity in tolerogenic OLT (DA-PVG) livers remained elevated for at least 2 months. CONCLUSION: These results suggest that telomerase activity in allogeneic OLT livers may reflect regenerating hepatocytes or activation of lymphocytes and/or hematopoietic stem cells associated with rejection or tolerance.     

Telomerase activity in human pleural mesothelioma

BACKGROUND: Gradual telomere erosion eventually limits the replicative life span of somatic cells and is regarded as an ultimate tumour suppressor mechanism, eliminating cells that have accumulated genetic alterations. Telomerase, which has been found in over 85% of human cancers, elongates telomeres and may be required for tumorigenesis by the process of immortalisation. Malignant mesothelioma is an incurable malignancy with a poor prognosis. The disease becomes symptomatic decades after exposure to carcinogenic asbestos fibres, suggesting the long term survival of pre-malignant cell clones. This study investigated the presence of telomerase in pleural malignant mesothelioma, which may be the target for future anti-telomerase drugs. METHODS: Telomerase activity was semiquantitatively measured in extracts from 22 primary pleural mesotheliomas, two benign solitary fibrous tumours of the pleura, four mesothelioma cell lines, and six short term mesothelial cell cultures from normal pleura using a non-isotopic dilution assay of the telomeric repeat amplification protocol. RESULTS: Twenty of the 22 primary mesotheliomas (91%) and all tumour derived mesothelioma cell lines were telomerase positive. Different levels of enzyme activity were observed in the tumours of different histological subtypes. Telomerase activity could not be detected in the six normal mesothelial cell cultures or in the two mesotheliomas. Both benign solitary fibrous tumours showed strong telomerase activity. CONCLUSIONS: Telomerase activity is found in a high proportion of mesotheliomas and anti-telomerase drugs might therefore be useful clinically. The results are consistent with the hypothesis that telomerase activity may be a feature of carcinogenesis in mesotheliomas and possibly in many other cancers.     

胃癌端粒酶活性检测的临床意义

目的　探讨端粒酶在胃癌组织中的活性及其临床意义。方法　应用银染 Ｔ Ｒ Ａ Ｐ 方法检测９４ 例胃癌组织、１２ 例胃腺瘤、９ 例胃溃疡和５８ 例癌旁正常胃粘膜中端粒酶活性。结果　９４ 例原发胃癌组织中检出端粒酶阳性８１ 例,阳性率为８６ ．２ ％ 。正常粘膜无１ 例检测到端粒酶表达,１２ 例胃腺瘤有１例表达端粒酶阳性,在９ 例胃溃疡组织中有１ 例检测到端粒酶表达,１２ 例胃腺瘤有１ 例表达端粒酶阳性,在９ 例胃溃疡组织中有１ 例检测到阳性端粒酶表达。胃癌与正常粘膜组端粒酶表达率差异有显著性（ Ｐ＜ ０ ．００１） 。端粒酶活性与肿瘤大小、分化程度、浸润深度、淋巴结转移和 Ｔ Ｎ Ｍ 分期无明显相关（ Ｐ＞ ０ ．０５） 。结论　测定胃癌端粒酶活性对胃癌的诊断有一定意义。     

尿脱落细胞端粒酶活性表达对尿路上皮癌的诊断价值

目的：探讨尿脱落细胞端粒酶活性表达对尿路上皮癌的诊断价值。方法：采用ＰＣＲ－ＣＬＩＳＡ法检测尿液中脱落的肿瘤细胞端粒酶活性,并以肾癌及非肿瘤患者的尿标本对照。结果：５９例尿路上皮癌患者尿脱落细胞端粒酶活性表达率为８８．１％,而肾癌患者为１０．０％,非肿瘤患者为２０．０％,前者与后两者比较,有极显著性差异（Ｐ〈０．０１）;不同分化程度及不同临床分期膀胱癌患者尿脱落细胞端粒酶活性表达率无显著性差异（Ｐ     

Telomerase activity in giant condyloma acuminatum

A 46-year-old male came to our hospital 1 month after noticing a 2-cm penile tumor. Since malignant findings such as atypical cells and mitosis were not observed in the frozen sections obtained at operation, the pathological diagnosis of this tumor was giant condyloma acuminatum. This tumor was analyzed by a telomeric repeat amplification protocol method, and telomerase activity was revealed. For comparison, a case of squamous cell carcinoma and a case of condyloma acuminatum were examined. Telomerase activity was observed in our case and in the case of squamous cell carcinoma. To our knowledge, this is the first case of telomerase activity in giant condyloma acuminatum ever reported. In addition to the histological examination, measurement of telomerase activity may provide valuable objective diagnostic information on evaluating the degree of malignancy of giant condyloma acuminatum and in obtaining a differential diagnosis between the benign and malignant.     

Telomerase activity in diagnosis of bladder cancer

OBJECTIVE: Telomerase is an enzyme that can reconstitute the ends of chromosomes after cell division and thus circumvent the damage that occurs in normal adult somatic cells during successive mitotic cycles. Immortal cells have short but stable chromosomes and increased telomerase activity. Transitional cell carcinoma (TCC) has only a few useful markers of diagnostic or prognostic importance. The objectives of this study were to determine whether there was a correlation between telomerase activities and the grade or stage of TCC and whether the activity of the enzyme could serve as a biochemical marker of this tumor. MATERIAL AND METHODS: Telomerase activity was determined by examining, using a polymerase chain reaction-based assay designed using the telomeric repeat amplification protocol (TRAP), urine cell pellets obtained from 42 bladder cancer patients, 18 patients with primary hematuria, 19 patients with benign urologic disease, 14 patients with urologic malignancies other than TCC and 20 healthy volunteers. RESULTS: Telomerase activity was found in 24/31 patients with bladder tumors (77.4% sensitivity) and in 5/77 patients without tumors (93.5% specificity). No correlation was found between telomerase activity and the grade or stage of the tumor. Although none of the urine cell pellets obtained from the 20 healthy volunteers demonstrated telomerase activity, positive telomerase activity was found in two subjects in the benign urologic disease group and in three subjects in the other urologic malignancy group. It was demonstrated that gross hematuria was the cause of false-negative results in six of the nine patients (66.7%). but washing the pellets four times and diluting them before the TRAP assay solved this problem. CONCLUSION: These results indicate that telomerase activity may be a promising marker for TCC but the technical aspects of the technique must be improved before it is used in routine clinical practice as a standard method. False-negative results obtained using gross hematuric urine should be carefully reevaluated and cell pellets should be washed again and diluted before analysis.