High Expression of Human Telomerase Reverse Transcriptase in High-Grade Intraepithelial Neoplasia and Carcinoma of Uterine Cervix and Its Correlation With Human Papillomavirus Infection

Evaluation of Telomerase (hTert), Ki67 and p16ink4a expressions in low and high-grade cervical intraepithelial lesions

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.

Prevalence of telomerase activity in human cancer

Telomerase activity has been measured in a wide variety of cancerous and non-cancerous tissue types, and the vast majority of clinical studies have shown a direct correlation between it and the presence of cancerous cells. Telomerase plays a key role in cellular immortality and tumorigenesis. Telomerase is activated in 80-90% of human carcinomas, but not in normal somatic cells, therefore, its detection holds promise as a diagnostic marker for cancer. Measurable levels of telomerase have been detected in malignant cells from various samples: tissue from gestational trophoblastic neoplasms; squamous carcinoma cells from oral rinses; lung carcinoma cells from bronchial washings; colorectal carcinoma cells from colonic luminal washings; bladder carcinoma cells from urine or bladder washings; and breast carcinoma or thyroid cancer cells from fine needle aspirations. Such clinical tests for telomerase can be useful as non-invasive and cost-effective methods for early detection and monitoring of cancer. In addition, telomerase activity has been shown to correlate with poor clinical outcome in late-stage diseases such as non-small cell lung cancer, colorectal cancer, and soft tissue sarcomas. In such cases, testing for telomerase activity can be used to identify patients with a poor prognosis and to select those who might benefit from adjuvant treatment. Our review of the latest medical advances in this field reveals that telomerase holds great promise as a biomarker for early cancer detection and monitoring, and has considerable potential as the basis for developing new anticancer therapies.

Survivin and telomerase expression in the uterine cervix of women with human papillomavirus-induced lesions

INTRODUCTION

Infection by human papillomavirus is the most important risk factor in the pathogenesis of uterine cervical cancer. The aims of this study were to evaluate the expression of survivin protein and telomerase enzyme in samples of uterine cervix from women with human papillomavirus-induced lesions and to determine the relationship between survivin and telomerase expression and the different grades of cervical squamous intraepithelial neoplasia and invasive cervical carcinoma.

METHODS

Biopsy samples from the uterine cervix of 105 women aged 18 to 80 years were analyzed. The patients were divided into 5 groups: WN group, 20 patients without neoplasia; CIN-1 group, 24 patients with grade 1 cervical intraepithelial neoplasia (CIN), grade 1; CIN-2 group, 20 patients with CIN grade 2; CIN-3 group, 24 patients with CIN, grade 3; and ICC group, 17 patients with invasive cervical carcinoma. Human papillomavirus detection, telomerase activity, and survivin expression were assessed using polymerase chain reaction (PCR), real-time PCR (RT-PCR), and immunochemistry, respectively.

RESULTS

There was a significant increase in the expression of telomerase and survivin associated with the severity of the lesion.

CONCLUSIONS

The results suggest that mechanisms that promote both cell proliferation (telomerase activity) and cell survival (survivin expression) are active in cervical cancer and its precursor lesions. There was a negative correlation between survivin expression and the number of PCR cycles necessary to detect telomerase activity in the total sample, achieving statistical significance in patients in the CIN-3 group.

Genomic amplification of the human telomerase RNA gene for differential diagnosis of cervical disorders

To evaluate genomic amplification of the human telomerase RNA gene (TERC) as a supportive approach to cytopathology or histopathology in diagnosis of low-grade and high-grade uterine cervical lesions, 1,033 Chinese women at three medical centers had liquid-based thin-layer cytopathologic examination and TERC detection by fluorescence in situ hybridization (FISH). Human papillomavirus DNA testing, colposcopy with or without biopsy, and histopathologic examination were conducted as needed. In cytopathologic examination, genomic amplification of TERC was found in 30 of 659 (4.6%) normal or benign cellular changes; in 23 of 170 (13.5%) atypical squamous cells of undetermined significance (ASCUS); in 8 of 28 (28.6%) atypical squamous cells with high-grade squamous intraepithelial lesion possible (ASC-H); and in 26 of 103 (25.2%) low-grade (LSIL) and 64 of 73 (87.7%) high-grade (HSIL) squamous intraepithelial lesions; with pairwise significant difference (P< 0.05) in each, except ASC-H and LSIL (chi(2) = 0.127, P = 0.72). In histopathologic examination, TERC was amplified in 28 of 671 (4.2%) normal, inflammatory, or wart cases; in 17 of 233 (7.3%) cervical intraepithelial neoplasia grade 1 cases (CIN 1); in 27 of 39 (69.2%) CIN 2 cases; in 57 of 67 (85.1%) CIN 3 cases; and in 22 of 23 (95.7%) cervical cancer cases; with pairwise significant difference in each (P < 0.05). The number of cells with abnormal signals increased and the abnormal signal patterns were diversified with increasing severity of cervical dysplasia. FISH detection of TERC amplification may provide an effective, noninvasive approach in conjunction with cytopathologic or histopathologic evaluation for differential diagnosis of low- and high-grade cervical disorders.

Genomic copy number alterations as predictive markers of systemic recurrence in breast cancer

We tried to establish models that predict systemic recurrence in breast cancer by selecting marker clones with DNA copy number alterations (CNAs) using an array comparative genomic hybridization (CGH). Array CGH containing 4,044 human bacterial artificial chromosome clones was used to assess CNAs in 62 primary breast cancer tissues from 31 patients with systemic recurrence within 5 years after surgery and clinicopathologically well matched 31 patients who had no evidence of disease for at least 5years. Fourteen significant clones (11 clones showing gain and 3 showing loss) were identified by systemic recurrence-free survival (SRFS) analysis and 23 significant clones (17 clones showing gain and 6 showing loss) identified by chi(2) test and FDR test were selected as predictive markers of systemic breast cancer recurrence. The significant CNAs were found in the chromosomal regions of 5p15.33, 11q13.3, 15q26.3, 17q25.3, 18q23 and 21q22.3 with gain and 9p12, 11q24.1 and 14q32.33 with loss. We devised 2 prediction models for the systemic recurrence of breast cancer based on the 14 clones and the 23 clones, respectively. The survivals of the patients were significantly separated according to the scores from each model at the optimal cut off values in SRFS and overall survival analysis. We found candidate clones and genes of which CNAs were significantly associated with systemic recurrence of breast cancer. The devised prediction models with these clones were effective at differentiating the recurrence and nonrecurrence.