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K Mokbel

Publications and source records attributed to K Mokbel.

At least 73 records · Page 4Linked to original sources
PubMed2000

The association between telomerase activity and hormone receptor status and p53 expression in breast cancer.

BACKGROUND: Telomerase is a ribonucleoprotein enzyme that seems to play an important role in cellular immortality and carcinogenesis. p53 mutations account for approximately 50% of human cancers and represent the most frequent genetic lesion in breast cancer. AIMS: This study aims to examine the association between telomerase reactivation and hormonal receptor status and p53 expression in invasive breast cancer. METHODS: Using a polymerase chain reaction-based assay, telomerase activity was determined in 47 invasive breast carcinomas and 21 adjacent non-cancerous breast tissue specimens (stored at -80 degrees C) prospectively collected from 47 women undergoing elective surgical treatment in our centre. The histopathological features of the tumour were determined by experienced breast pathologists using light microscopy and haematoxylin and eosin staining. Oestrogen receptor (ER), progesterone receptor (PR) and p53 expressions were determined using immunohistochemistry techniques. RESULTS: Telomerase activity was detected in 34 (72%) of 47 breast carcinomas and in none of the adjacent non-cancerous breast specimens. There was a significant association between telomerase reactivation, tumour size and nodal status. Telomerase positive tumours were more likely to be poorly differentiated (65% versus 46%), but this association failed to reach statistical significance. There was no significant difference in ER expression (68% versus 85%). PR expression (62% versus 62%) and p53 expression (19% versus 27%) between telomerase positive and telomerase negative cancers. CONCLUSION: Telomerase reactivation is associated with important prognostic factors such as tumour size and nodal status in invasive breast cancer and seems to be independent of hormonal receptor status and p53 expression.

Biopsy, Needle↗
PubMed2000

Telomerase and breast cancer: from diagnosis to therapy.

BACKGROUND: Telomeres are believed to be responsible for chromosomal stability during cellular proliferation. They are created by telomerase, an enzyme present in many human neoplasms. Telomerase is considered to be important in breast cancer since reactivation of the enzyme ensures cell stability allowing malignant cells to divide indefinitely. AIMS: This article aims to discuss the role of telomerase in breast cancer and explore the future of telomerase research. METHOD: We have reported on the literature to date in order to present this current review. RESULTS: Telomerase is found in significant levels in breast neoplasms and is reliably detected in fine needle aspirations aiding the diagnosis of breast cancer. There is also a correlation between telomerase and disease prognosis, and there is current work assessing if telomerase can be of benefit in monitoring the efficacy of systemic treatment. CONCLUSION: The role of telomerase in breast cancer is still being investigated however by understanding the action it has on chromosomal stability, and its detection in tumour cells, there are possibilities to enhance the methods employed to detect and treat breast cancer.

Biomarkers, Tumor↗
PubMed1999

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.

Adult↗
PubMed1999

Telomerase activity and prognosis in breast cancer.

AIMS: Telomerase is a ribonucleoprotein enzyme which appears to play an important role in carcinogenesis. Its reactivation is associated with the acquisition of immortalization and malignancy. The present study aims to examine the association between telomerase activity and prognosis in breast cancer. METHODS: Using a PCR-based assay, we retrospectively examined telomerase activity in 45 frozen human breast cancer specimens. Telomerase activity was compared with histopathological and clinical data. RESULTS: Telomerase activity was detected in 20 (44%) of 45 cases and was associated with advanced histopathological grade and tumour type (ductal vs. lobular). The association with these histological parameters was statistically significant (chi-squared test P<0.05). There was no significant difference in the overall survival rate (78 vs. 77%) or disease-free survival (73 vs. 69%) at 5 years (Kaplan-Meier method, log-rank test P>0.05). CONCLUSIONS: The present results indicate that telomerase activity in human breast cancer is not associated with nodal status or disease outcome.

Adult↗
PubMed1999

Telomerase activity in phyllodes tumours.

AIMS: To investigate telomerase, a ribonucleoprotein that synthesizes telomeres. Recent evidence suggests that telomerase reactivation is associated with the acquisition of immortalization and malignancy. METHODS: Using a sensitive PCR-based assay (the TRAP assay), we examined telomerase activity in two recurrent phyllodes tumours in two patients. RESULTS: Both tumours expressed telomerase activity. Histological examination of the lesions, according to the criteria proposed by Azzopardi and Salvadori, revealed a malignant phyllodes tumour in one patient and a benign phyllodes tumour in the other patient. CONCLUSIONS: Our findings suggest that telomerase activity may have a potential role as a prognostic marker in predicting the clinical behaviour of these rare tumours.

Aged↗