Detection of human telomerase reverse transcriptase messenger RNA in urine of high risk patients as a non invasive molecular diagnostic tool for urinary bladder cancer in Egyptians

Bladder cancer is an important national health problem as it is the leading cancer in men in Egypt. Cystoscopy and biopsy, currently remains the gold standard procedure for diagnosis, yet, it is invasive and costly. Urinary cytopathology remains to be the only non-invasive alternative method for diagnosis. Although it is tumour specific, yet it has a poor sensitivity, especially for low grade tumours. Detection of Telomerase enzyme in exfoliated urinary cells is a potentially good molecular diagnostic marker in bladder cancer, since the catalytic subunit of this enzyme [hTERT] proved to be essential for cellular immortality and oncogenesis. The study comprised 39 patients [36 with urothelial carcinomas and 3 cases were squamous cell carcinoma] with bladder cancer and 22 non cancer control [including 14 patients with benign urological disorders and 8 healthy volunteers]. The urine sample was split into two aliquots one was used to undertake RNA extraction and hTERT/GAPDH RT-PCR semi-quantitative assay and the second for cytological examination. Cystoscopy was considered the reference standard for the identification of bladder cancer. The hTERT/GAPDH RT-PCR test showed significantly higher diagnostic sensitivity than cytology [84% Vs. 75% p<0.008] for confirmed UCC, particularly for low grade non-muscle invasive UCC [82% Vs. 64% p<0.005]. On combining the two tests a sensitivity of 95% was obtained. A positive hTERT expression was detected 4-5 months earlier than cystoscopic evidence of recurrence in 2 patients during their follow up. In this pilot study, detection of hTERT expression in urine has shown to be a more sensitive marker for diagnosis of bladder cancer than cytology. The combination of urinary hTERT mRNA with cytological testing augments the sensitivity for the non-invasive early diagnosis of bladder cancer. This finding warrants further extended study to validate the potential role of hTERT expression as a diagnostic non invasive tool for high risk patients and detection of recurrence in bladder cancer in Egypt

Comparative study of immunohistochemical analysis in tissues and molecular detection in exfoliated tumour cells in urine of human telomerase reverse transcriptase [hTERT] in urinary bladder cancer in Egyptians

Bladder cancer ranks the third most common malignancy in Egypt following to breast cancer and leukemia. Telomerase plays important roles in cancer development and promotion. Its activity is present in most human malignant tumor cells. Its activity was also detected in voided urine and in bladder washes of patients with bladder cancer, making it a potential marker for non invasive detection of bladder cancer in urine. The present study aims to correlate the expression of the hTERTmRNA in exfoliated tumour cells in urine to the in situ expression of hTERT protein in the corresponding tumour specimens and to evaluate the relationship to hTERT expression and the clinicopathologic tumour characteristics. The study comprised twenty three bladder cancer cases [22 urothelial and one squamous cell carcinomas]. Semiquantitative immunohistochemical detection of hTERT expression was evaluated using combined score evaluated by two examiners which included scoring of intensity and percentage of positivity Semiquantitative expression of hTERTmRNA relative to housekeeping gene GAPDH mRNA was evaluated from RNA extracted from exfoliated cells in urine. Expression of hTERT by immunohistochemistry [IHC] and RT-PCR was detected in 100% of the bladder cancer series. Both methods were significantly correlated [p=0.004]. There was no correlation detected between hTERT expression by both methods and clinicopathologic characteristics of the tumours represented by stage and grade. The high concordance between the semiquantitative expression of hTERT protein by IHC in tumour sections and hTERTmRNA in exfoliated tumour cells validate the potential use of hTERT as a diagnostic non invasive marker for diagnosis of bladder cancer in high risk Egyptian patients and in the follow up following cystoscopic resection of superficial tumours. To the best of our knowledge this is the first study which compares hTERT in situ expression in bladder tumours and hTERT mRNA in exfoliated tumour cells in urine