Evaluation of Telomerase (hTert), Ki67 and p16ink4a expressions in low and high-grade cervical intraepithelial lesions / Avaliação da expressão de Telomerase (hTert), Ki67 e p16 ink4a em lesões intraepiteliais cervicais de baixo e alto graus

ABSTRACT Objective : to study the association between the histological grading of cervical intraepithelial neoplasia (CIN I, CIN II and CIN III) and the immunohistochemical expression for p16ink4a, hTert and Ki67, as well as to evaluate the relationship of these markers with the risk of recurrence after surgical treatment. Methods : we studied a historical cohort of 94 women with intraepithelial lesions CIN I (low grade), CIN II and CIN III (high grades) submitted to conization or electrosurgical excision of the transformation zone. We evaluated all surgical specimens for immunohistochemical expression of p16ink4a, hTert and Ki67. Results : the mean age was 38.2 years; p16ink4a was absent in most CIN I cases. In patients with CIN II or I/II (association of low and high-grade lesions), we observed p16ink4a ≤10%. In patients with CIN III, we found a higher expression frequency of p16ink4a >50%. In CIN I, the majority had Ki67≤10% and low frequency of Ki67>50%. In the CIN III category, there were fewer patients with Ki67≤10%, and Ki67 was absent in most patients of CIN II and III groups. There was no association between hTert expression and histologic grade. There were no statistically significant differences between the expression of the markers in patients with and without recurrence. Conclusion : there was a statistically significant association of p16ink4a and Ki67 with histological grade. The markers' expression, as for disease recurrence, was not statistically significant in the period evaluated.

RESUMO Objetivo: estudar a associação entre a graduação histológica das neoplasias intraepiteliais cervicais (NIC I, NIC II e NIC III) e a expressão imuno-histoquímica para p16ink4a, hTert e Ki67, assim como, avaliar a relação destes marcadores com o risco de recorrência após tratamento cirúrgico. Métodos: estudo de coorte histórica de 94 mulheres portadoras de lesões intraepiteliais NIC I (baixo grau), NIC II e NIC III (altos graus), submetidas à conização ou à excisão eletrocirúrgica da zona de transformação. Todas as peças cirúrgicas foram avaliadas quanto à expressão imuno-histoquímica para p16ink4a, hTert e Ki67. Resultados: a média de idade das pacientes foi 38,2 anos. Nas pacientes NIC I, a p16ink4a estava ausente na maioria dos casos; nas pacientes NIC II ou I/II (associação de lesões de baixo e alto graus), observou-se frequência de p16ink4a≤10%. Nas pacientes NIC III, observou-se maior frequência de expressão de p16ink4a>50%. Na categoria NIC I, a maioria apresentava Ki67≤10% e baixa frequência de Ki67>50%. Na categoria NIC III houve menor número de pacientes com Ki67≤10%, sendo que a maior parte das pacientes tinha Ki67 ausente nos grupos NIC II e III. Não houve associação entre a expressão do marcador imuno-histoquímico hTert e a graduação histológica. Não houve diferenças estatisticamente significativas entre as expressões dos marcadores em pacientes com e sem recorrência. Conclusão: houve associação estatisticamente significativa apenas de p16ink4a e Ki67 com a graduação histológica. A expressão dos marcadores em relação à recorrência da doença não foi estatisticamente significativa no período avaliado.

Human telomerase reverse transcriptase expression in ovarian tumors.

Background : Ovarian cancer is the 6 th most common cancer among women. In ovarian tumors, the borderline category is not well defined due to the difficulty in assessing stromal invasion. The World Health Organization (WHO) defined it as tumor that lacks obvious invasion of the stroma with mitotic activity and nuclear abnormalities intermediate between clearly benign and unquestionably malignant. Telomerase is expressed in many human cancers and is hence a potential biomarker for cancer. Immunohistochemical study of anti-human telomerase enzyme reverse transcriptase (hTERT) antibody allows direct visualization of its expression. The aim of this study was to determine the expression of hTERT and serum CA-125 level in ovarian epithelial tumors, and their ability to distinguish borderline tumor from malignancy. Materials and Methods : This was a retrospective study on 68 ovarian epithelial tumors, comprising of 41 cystadenocarcinoma, 22 borderline tumor and five cystadenoma. By immunohistochemistry, hTERT expression was graded as negative (0-10%), focal (11-25%), regional (26-75%) and diffuse (>75%) positivity. Results : hTERT protein expression in ovarian cystadenocarcinoma, borderline tumor and cystadenoma were 71.4%, 59.1% and 0%, respectively. hTERT and CA-125 had a linear relationship with tumor grade and stage. hTERT protein is detected as large granules/speckled in the cytoplasm and nuclei of ovarian tumors. Conclusions : hTERT protein was highly expression in ovarian epithelial carcinoma. However, the difference between carcinoma and borderline tumor was not statistically significant (P-value = 0.51). It is not an independent biomarker to differentiate borderline tumor from malignant tumor. We suggest using the combination of hTERT immunohistochemistry and serum CA-125 to evaluate difficult situations where histological evaluation fails to distinguish malignant from borderline ovarian tumor.

Evaluation of telomerase expression in chronic periodontitis.

Background : Human telomerase is a multi subunit ribonucleoprotein enzyme concerned with telomeric lengthening and homeostasis in man. This enzyme has been found to be elevated in inflammatory conditions like rheumatoid arthritis and silica injury lung. Since chronic periodontitis is also an inflammatory condition where immune cells and cytokines mediate tissue destruction, we set out to evaluate telomerase in gingival tissue samples from healthy subjects and chronic periodontitis patients by reverse transcriptase polymerase chain reaction. Materials and Methods : Gingival biopsies were obtained from eight healthy subjects and eight chronic periodontitis patients. Reverse transcriptase polymerase chain reaction (RTPCR) was carried out to evaluate telomerase gene expression in the samples. Results : None of the healthy gingival tissue samples expressed the telomerase gene while all the chronic periodontitis samples expressed it. The severe chronic periodontitis samples expressed the gene more intensely than the moderate chronic periodontitis samples. Conclusion : Various mechanisms have been explained to account for telomerase elevation in chronic periodontitis .This study helps us understand the role of telomerase in the pathogenesis of periodontal disease. It could be concluded that telomerase could be used as a marker to assess the severity of inflammation in chronic periodontitis.

Immunohistochemical expression of h-telomerase reverse transcriptase in canine and feline meningiomas

Telomere length maintenance is regarded as a fundamental step in tumorigenesis, as most human brain tumors, including meningiomas, stabilize the ends of their chromosomes using telomerase. This investigation represents an introduction to telomerase expression in canine and feline meningiomas. Twenty-five archived cases (14 dogs and 11 cats) were immunohistochemically tested for human-telomerase reverse transcriptase (h-TERT), scored, and quantified; furthermore, mitoses were counted on sections stained with a modified toluidine blue. The h-TERT antibody immunolabelled the nucleus and nucleolus of meningeal neoplastic cells, with an intensity ranging from mild to strong and a speckled distribution; a significantly higher expression in cats was noted, while no significant association between h-TERT immunolabelling and sex or histotype was evident in dogs or cats. The telomerase enzyme represents a fundamental parameter of potential malignant transformation, which may occur independently of the signal to proliferate, thereby supplying the cells with unlimited growth capabilities. Telomerase expression could be a prognostic indicator independent of the kinetic parameters, although this should be evaluated using a larger dataset with available clinical information.

Expression of telomerase subunits in gastric cancer / 华中科技大学学报（医学）（英德文版）

To detect the expression of telomerase subunits (human telomerase reverse transcriptase, human telomerase associated protein 1 and human telomerase RNA) in gastric cancer and to examine the role that different telomerase subunits play in the gastric carcinogenesis, reverse transcription-polymerase chain reaction (RT-PCR) was used to detect telomerase subunits messenger RNA in 24 samples of gastric cancer and corresponding non-cancerous tissue. The results showed that the positive rate of hTERT mRNA from gastric cancer and corresponding non-cancerous tissues was 100% and 25%, respectively. The former was significantly higher than the latter (chi2 = 26.4, P 0.05). The positive rates of hTR for gastric cancer and corresponding non-cancerous tissues were both 100% and no significant difference existed between them. It is concluded that in contrast to hTEP1 and hTR, the up-regulation of hTERT mRNA expression may play a more important role in the development of gastric cancer.