WO1997035871A1

WO1997035871A1 - Detecting bladder cancer by telomerase activity

Info

Publication number: WO1997035871A1
Application number: PCT/US1997/004888
Authority: WO
Inventors: Brian Liu; Elizabeth Kaveler
Original assignee: Mount Sinai School Of Medicine Of The City University Of New York
Priority date: 1996-03-27
Filing date: 1997-03-26
Publication date: 1997-10-02
Also published as: JPH09262100A; AU2547697A

Abstract

The present invention relates to a method for detecting bladder cancer cells in a urine sample collected from a subject, comprising measuring telomerase activity, wherein an increase in telomerase activity bears a positive correlation with the presence of bladder cancer cells in the sample.

Description

DETECTING BLADDER CANCER BY TELOMERASE ACTIVITY

1. Introduction

The present invention relates to a method for detecting bladder cancer cells in a cytology sample collected from a subject comprising measuring telomerase activity, wherein an increase in telomerase activity bears a positive correlation with the presence of bladder cancer cells in the sample.

2. Background of the Invention

2.1. Cell Proliferation and Telomerase Activity

In 1973, Olovnikov proposed that cells lose a small amount of DNA at their terminal ends with each replication. The 3' to 5' (leading) strand of the parent DNA is copied in a continuous manner, but the 5' to 3' (lagging) strand of the parent DNA is copied discontinuously as Okazaki fragments. Each fragment is primed with an RNA primer, which is subsequently degraded. The fragments are then ligated by DNA repair enzymes that operate behind the replication fork. The 3' end of the lagging strand is then left incompletely copied and is lost. This piece of nucleotide is called a telo ere (Blackburn, 1991, Trends Biol. Sci. 16 :378) . The cell can only afford to lose a finite number of these telomeres before sequences of the parent DNA are lost, resulting in chromosomal instability and subsequent cell death (Harley, 1991, Mutation Res. 256 :271) . Fifty to two hundred nucleotides are lost with each round of replication (Blackburn, 1991, Nature 3_5_0:569) .

Germ cell telomeres are expressed despite multiple rounds of replication suggesting that they produce an enzyme, telomerase, that maintains their telomere length (Hastie et al . , 1990, Nature 346 :866) . The telomere sequence is synthesized by a ribonucleoprotem called telomerase.

Telomere length and telomerase activity appear to be markers in the replicative history of a cell. Besides germ cells, telomerase is found n immortal human tumor cell lines. It is not found in normal somatic cells . Telomerase activation may play a key role in transforming a mortal somatic cell into an immortal tumor cell (Haber, 1995, N. Engl. J. Med. 33_ :955) .

Kim and coworkers reported a correlation between cancer and the expression of telomerase (Kim et al. , 1994, Science 6_6_:2011-2015) . His group identified telomerase activity in tissue specimens from a wide variety of different cancers and immortal cell lines; malignant tissues expressing telomerase activity included skin, connective tissue, adipose tissue, breast, lung, stomach, pancreas, ovary, cervix, uterus, kidney, bladder, colon, prostate, nervous system tissue, and blood cells.

Bednarek et al . (1995, Cancer Res. 5_5_:4566-4569) reported that in the mouse skin chemical carcmogenesis system, telomerase activity increased in proportion with premalignant tumor progression.

United States Patent No. 5,489,508 by West et al. relates to the therapy and diagnosis of conditions related to telomere length and/or telomerase activity. Although a correlation between malignancy and telomerase activity is described, there is no disclo¬ sure which suggests that a telomerase assay could be used as a sensitive and specific detector of exfoliated bladder cancer cells m a ur e specimen.

2.2. Current Methods for Diagnosing Bladder Cancer Current methods for the diagnosis of bladder cancer are inadequate. Hematuria, the most common presenting symptom in patients with bladder cancer, is a non-specific laboratory finding and may occur in patients with benign disease. The first step in evaluating a patient who presents with hematuria is cytological analysis of a voided urine sample. Cytologic examination has numerous shortcomings, however, the most significant of which are high rates of atypia in patients with benign conditions, and false negative results, particularly in patients with low grade tumors. If voided urine cytology were the only diagnostic test available for low-grade bladder tumors, only 25% of patients would have a correct diagnosis (Gamarra and Zein, 1984, Supplement to Urology 23 (3) :23) . Therefore, preoperative cystoscopy, an invasive procedure, has typically been performed in conjunction with cytologic examination of urine.

In view of the need for a sensitive and specific non-invasive assay for the detection of bladder cancer, we have developed a method in which the level of telomerase activity is measured in exfoliated cells from voided urine of patients with hematuria, whereby an increase in telomerase activity bears a strong correlation to the diagnosis of bladder cancer and is associated with significantly fewer false positive and false negative results relative to conventional cytology.

3. Summary of the Invention

The present invention relates to a diagnostic method whereby a urine sample from a subject being evaluated for the presence of a bladder cancer may be assayed for telomerase activity. It has been discovered that the presence of telomerase activity is a more sensitive and specific indicator of the presence of bladder cancer cells, and particularly low grade bladder cancer cells, compared to conventional cytological analysis. The increased sensitivity and specificity of the telomerase assay results may obviate the performance of unnecessary invasive cystoscopy in patients who exhibit false negative cytology results.

. Description of the Figures FIGURE 1: Sensitivity of assay: Sensitivity of detection involved identification of telomerase activity in cell extracts from invasive (T24) bladder cancer cells. The cell lysates were extracted from a known number of cells and the telomerase repeat amplification protocol (TRAP) assay was performed to amplify the telomeres. With this method, we were able to determine that only 50 invasive tumor cells per sample was needed to identify telomerase activity. FIGURE 2: Sensitivity of assay: Using cell extracts from superficial (RT4) bladder cancer cells, we were able to determine that only 200 superficial tumor cells per sample were needed to identify telomerase activity with the TRAP assay.

FIGURE 3: Exfoliated cells from voided urine specimens were obtained from patients with benign causes of hematuria and from one patient with prostate cancer who presented with hematuria. Lane 1: T24 bladder cancer cells as control. Lane 2 to lane 4 are patients #2 to 4 that have benign cause of hematuria. Lane 5 is the lysis buffer and served as a negative control .

FIGURE 4 : Exfoliated cells from voided urine samples of patients with various grades of bladder cancer were tested for telomerase activity.

5. Detailed Description of the Invention

The present invention relates to a method for detecting bladder cancer cells in a urine sample of a subject in need of such evaluation, wherein an increase in the level of telomerase activity relative to control levels has a positive correlation with the presence of bladder cancer cells.

A "subject in need of such evaluation" includes any sub ect, who may reasonably be tested for the presence of bladder cancer, including, but not limited to, a subject who exhibits hematuria, who suffers from difficulty urinating or from painful, or unduly frequent, urination, or who is at risk for developing bladder cancer. Subjects at risk for developing bladder cancer include those subjects having a history of bladder cancer or toxin exposure, subjects havmg indwelling urinary catheters, smokers, and patients suffering from or having a history of Schistosomiasis infection. Other subjects in need of such evaluation are subjects who have been previously diagnosed and treated for bladder cancer and who need follow-up evaluation for recurrent disease. Alteratively, a "subject in need of such evaluation" may be asymptomatic and may merit evaluation only for routine screening purposes.

A "subject", according to the invention, is preferably a human subject but may also be a non-human mammalian subject.

A urine sample, according to the invention, may be a voided urine sample or may be obtained by catheteri- zation. In preferred, non-limitmg embodiments, the volume of the urine sample is at least 20 ml, and more preferably at least 100 ml. In preferred, nonlimiting embodiments of the invention, the sample size is such that at least 50-400 exfoliated cells, and more preferably at least 200 exfoliated cells, are present in the sample. The term "exfoliated cell" refers to a normal or malignant cell havmg its origin m the mucosa of the bladder. The term "increased telomerase activity" refers to a level of telomerase activity which is increased relative to a negative control, defined herein as the amount of telomerase activity present in a urine sample of essentially the same volume from a subject who does not suffer from any malignant disease. An "increase" preferably refers to a level which is at least 1.5 - times background levels, and more prefer¬ ably at least five-times background levels. Because the level of telomerase activity in such a normal sample is essentially zero, the term "increased telomerase activity," for practical purposes, refers to any telomerase activity above background levels, such that running a control urine sample in parallel with actual test samples is not always necessary.

The methods described herein may be used not only to detect the presence or absence of telomerase or telomerase activity but may also be used to measure the amount of telomerase or telomerase activity. The term "measure" as used herein refers to either quantitative measurement or a less rigorous comparative evaluation, such as, for example, the determination that the amount of telomerase or the level of telomerase activity is some multiple of a background amount or level. As such, autoradiographic analysis of gels or blots may be used to measure the amount of telomerase or telomerase activity according to the invention. The level of telomerase activity may be detected and/or measured by any method known in the art, includ¬ ing, but not limited to, assays which detect and/or measure the activity of telomerase activity on a nucleic acid primer substrate, as well as assays which measure the amount of telomerase protein or the amount of ribonucleic acid which encodes telomerase protein. For example, antibody (polyclonal or monoclonal) may be used to detect and/or quantitate the amount of telomerase enzyme present, for example, using in situ hybridization, enzyme-linked immunoabsorbent assay techniques, or a dip stick method or any alteration of procedure for clinical practical use. Alternatively, the lengths of telomeres may be measured and compared to the lengths of telomeres in cells of the same histologic type contained in a urine sample from a subject matched by age, tumor grade, level of invasion, or any other prognostic indicator.

The level of telomerase enzyme activity may be measured by a variety of techniques, including, but not limited to, the telomeric repeat amplification protocol (hereinafter, "TRAP") disclosed in Kim et al . , 1994, Science 266:2011-2015. Such polymerase chain reaction ("PCR") based techniques offer the advantage of allow¬ ing the detection of extremely low levels of telomerase activity.

In order to minimize background levels that may obscure the measurement of telomerase activity, it is preferable that the amount of red blood cells, white blood cells, necrotic tissues, and/or cellular debris be decreased or eliminated prior to measurement of telomerase activity. These elements may be decreased or eliminated by filtration, centrifugation, precipita¬ tion, chromatography, any combination thereof or any other method known m the art. In preferred embodi¬ ments of the invention, red blood cells, white blood cells, necrotic tissue and cellular debris may be substantially removed, where the term "substantially removed" refers to the removal of at least 50 percent of the total amount of red blood cells, white blood cells, necrotic tissue and cellular debris present in the urine sample. In a specific, non-limiting embodiment of the mvention, a voided urine sample, having a volume of approximately 100 ml, may be evaluated for telomerase activity as follows: The sample, soon after collec¬ tion, may be applied to a .45 micron Millipore filter, such that exfoliated cells containing telomerase activity may be retained by the filter, and other elements, including red blood cell components, may be removed. Cells retained on the filter may then be washed in ice-cold phosphate-buffered saline, pelleted at 10,000g for 30 min. at 4°C, resuspended in ice-cold wash buffer [10 mM HEPES-KOH (pH 7.5) , 1.5 mM MgCl,, 10 mM KCI, ImM dithiothreitol] , pelleted again, and then resuspended at 50 to IO⁴ cells per 5 to 100 microliters of ice-cold lysis buffer [10 mM tris- HC1 (pH 7.5) , 1 mM MgCl₂, ImM EGTA, 0.1 mM phenylmethyl¬ sulfonyl fluoride, 5mM /3-mercaptoethanol, 0.5% CHAPS (Pierce) , 10% glycerol] . The suspension may then be Potter-Elvejhem homogenized and incubated for 30 min. on ice and then may be centrifuged for 10 min. in a microcentrifuge (14,000g, 4°C) . The supernatant may then be recovered for further assay and the pellet discarded. If the supernatant is cloudy, it may further then be microultracentrifuged for 30 min. (100,000g, 4°C) , after which the resulting pellet may be discarded and the supernatant used for telomerase assay. Hereafter, the cellular extract prepared as set forth above, including any supematants collected, i.e. the material to be assayed for telomerase activity, will be referred to as the "sample extract". The sample extract may be quick-frozen on dry-ice, and stored at -70°C until assay. For performance of the telomerase assay, the following oligonucleotides may be used: a first oligonucleotide onto which telomerase may synthesize telomeric repeats (for example, but not limited to, the "TS" oligonucleotide, 5' -AATCCGTCGAGCAGAGTT-3' ; SEQ ID N0:1) ; and a second oligonucleotide which may serve as a primer for amplification of telomerase products (for example, but not limited to, the "CX" oligonucloetide 5' - (CCCTTA)₃CCCTAA-3 ; SEQ ID NO:2) .

Further in this specific, nonlimiting embodiment, the TRAP assay may be performed as follows. Assay tubes may be prepared by lyophilizing 0.1 microgram of CX primer onto the bottom of at least a 0.25 ml Eppendorf assay tube and then sealing the resulting pellet with about 7-10 microliters of molten wax (A pliwax, Perkin-Elmer) heated at 65°C for about 2 min. After the wax has been allowed to solidify at room temperature, the tubes may be stored at 4°C.

Then, TRAP reaction mixtures may be produced above the wax which are 20mM tris-HCl (pH 8.3) , 1.5rruM MgCl,, 63 mM KCI, 0.005% Tween-20, ImM EGTA, 0.1 mg/ml of bovine serum albumin and 50 micromolar deoxynucleoside triphosphates, and which contain 0.1 microgram of TS oligonucleotide, 1 microgram of T4g32 protein (Boehringer Mannheim) , 2 Units of Taq DNA polymerase (Boehringer Mannheim), .15 microliters of [α-³²P] dCTP and 1-15 microliters (preferably 15 microliters) of the sample extract prepared as set forth above; wherein the final reaction volume may be adjusted to 50 microliters with distilled, sterilized autoclaved water. Extension of TS oligonucleotide by any telomerase present may then be allowed to proceed for about 10 minutes at approximately 23°C, and then the assay tube may be transferred to a thermal cycler for about 27 rounds at 94°C for 30 seconds, 50°C for 30 seconds, and 72°C for 1.5 minutes. The CX primer should be liberated by melting of the wax barrier at elevated temperature during the cycling process, permitting amplification to occur. The results of the TRAP reaction may then be analyzed by electrophoresis in 0.5X tris-borate EDTA on 12% polyacrylamide denaturing gels, and then subjected to autoradiography. The skilled artisan may appreciate that the foregoing specific embodiment may be modified in a variety of ways to measure telomerase activity. For example, in the above method, as an alternative to the use of radioactive label, a detectably labeled probe complementary to the TS oligonucleotide may be used to hybridize to a DNA blot of unlabeled reaction products of TRAP in order to detect those products. In other embodiments, the TS oligonucleotide may be modified or replaced with an analogous sequence with a unique portion (that may be hybridized in detection methods) as well as a portion suitable for telomerase extension; telomerase is capable of extending oligonucleotides of nontelomeric sequence (Morin, 1991, Nature 353:454) . Alternatively, the oligonucleotide to be extended may lack such a unique portion, particularly where the product of the extension reaction or an amplification thereof is directly labeled. In still further embodi¬ ments, the CX oligonucleotide may be modified, although at least one iteration of (CCCTTA; SEQ ID NO:3) should be included, as well as a portion that hybridizes to a portion of the oligonucleotide used as a substrate for telomerase extension. Furthermore, any detectable label may be used, including nonradioactive labels which may be detected by enzymatic, chemical, or fluorescence-based methods. In alternative, less preferred embodiments, the assay need not include an amplification step, but rather, the products of telomerase extension may be measured directly.

The term "positive correlation" refers to a substantial probability that where a urine sample is found to contain telomerase activity exceeding back- ground levels, there are likely to be bladder cancer cells present. Based on currently available data, the percentage of true positive results by telomerase assay is greater than about 75 percent and the percentage of false negatives is less than about 25 percent.

6. Example: Detection of Exfoliated Bladder Cancer Cells in Voided Urine Samples by Measuring Telomerase Activity

6.1. Materials and Methods

Cell lines: The human bladder cancer T24 and RT4 cell lines were used. All cultures were maintained in

RPM1-1640 (Whittaker Bio-Products, MD) containing

10% of heat activated fetal calf serum, 2mM glutamine, 1% non-essential amino acids, 100 ug penicillin per ml, and 100 ug streptomycin per ml.

Cell line lysates: Cells were washed once in phosphate-buffered saline, pelleted at 10,000 X g for 10 min. at 4°C, resuspended in ice-cold wash buffer

[10 mM Hepes-KOH (pH 7.5) , 1.5 mM MgCl₂, 10 mM KCI, 1 mM dithiothreitol] , pelleted again, and resuspended at 50 - IO⁴ cells per 5-100 ul of ice-cold lysis buffer [10 mM tris-HCl (pH 7.5) , 1 mM MgCl₂, 1 mM EGTA, 0.1 mM phenylmethylsulfonyl fluoride, 5 mM B-mercaptoethanol , 0.5% CHAPS (Pierce) , 10% glycerol] . The suspension was incubated 30 min on ice and then centrifuged in a microcentrifuge (14,000g for 10 min. at 4°C) . The supernatant (henceforth, "sample extract") was removed, quick-frozen, and stored at -70°C until use.

Patient samples: 20 - 100 ml voided urine samples were obtained from patients with hematuria. The samples were freshly filtered on a 0.45 micron filter unit (Nalgene) . Cells retained on the filter were washed in ice-cold phosphate-buffered saline, pelleted at 10,000g for 30 min. at 4°C, resuspended in ice-cold wash buffer [10 mM HEPES-KOH (pH 7.5) , 1.5 mM MgCl,, 10 mM KCI, ImM dithiothreitol] , pelleted again, and then resuspended at 50 to IO⁴ cells per 5 to 100 microliters of ice-cold lysis buffer [10 mM tris-HCl (pH 7.5) , 1 mM MgCl₂, ImM EGTA, 0.1 mM phenylmethyl¬ sulfonyl fluoride, 5mM /3-mercaptoethanol, 0.5% CHAPS (Pierce) , 10% glycerol] . The resulting suspension was then Potter-Elvejhem homogenized and incubated for 30 min. on ice, and then was centrifuged for 10 min. in a microcentrifuge (14,000g, 4°C) , and the supernatant collected. Then, if the supernatant appeared cloudy, it was further microultracentrifuged for 30 min. (100,000g, 4°C) , after which the resulting pellet was discarded and the supernatant used for telomerase assay. The supernatant following microcentrifugation and/or microultracentrifugation, which was then used in TRAP assay, is henceforth referred to as the "sample extract" .

Telomeric repeat amplif cation protocol (TRAP) assay: Assay tubes were prepared by lyophilizing 0.1 ug of CX primer (see below) onto the bottom of the tube and sealing it with Ampliwax (Perk -Elmer) . Fifty microliter TRAP reactions above the wax barrier contained 20 mM tris-HCl (pH 8.3) , 1.5 mM MgCl₂, 63 mM KCI, 0.005% Tween-20 ImM EGTA, 50 uM dNTP, 0.1. ug of TS primer (see below) , 2U AmpliTaq DNA polymerase (Perkin-Elmer) , 1 ug of T4g32protem (Boehringer Mannheim), bovine serum albumin (0.1 mg/ml) , 1 to 15 ul of sample extract, and 0.2 ul of α-32P[dCTP] (Amersham) was added as described by (Kim et al . , 1994, Science 266.:2011) .

After 10 min at 23°C for extension of oligonucleo¬ tide TS by telomerase, tubes were transferred to a thermal cycler for 27 rounds at 94°C for 30 seconds, 50°C for 30 second, and 72°C for 1.5 min as previously described (Kim et al . , 1994, Science 266 :2011) . The reaction was analyzed by electrophoresis in 0.5X tris- borate EDTA on 12% polyacrylamide nondenatuπng gels and autoradiographed as previously described (Ki et al., 1994, Science 266 :2011) . The TS primer is: 5' -AATCCGTCGAGCAGAGTT-3' ; SEQ ID NO: 1

The CX primer is: 5' - (CCCTTA)₃CCCTAA-3' ; SEQ ID NO:2

These primers were previously described (Kim et al. , 1994, Science 266:2011) .

6.2. Results

Sensitivity of assay: Sensitivity of detection involved identification of telomerase activity in cell extracts from known superficial (RT4) and invasive (T24) bladder cancer cell lines. The cell lysates were extracted from a known number of cells and the telo erase repeat amplification protocol (TRAP) assay was performed to amplify the telomeres . With this method, we were able to determine that only 50 invasive and 200 superficial tumor cells per sample were needed to identify telomerase activity (Fig. 1 and Fig. 2) . Furthermore, we found that we can detect one cancer cell per 10,000 normal cells with this PCR based TRAP assay.

Negative telomerase expression in patients without bladder cancer: Exfoliated cells from voided urine specimens were obtained from 13 patients with benign causes of hematuria and from one patient with prostate cancer who presented with hematuria. The patient with prostate cancer had a false positive result on cytologic examination of voided urine, with a cystoscopic exam that was negative for bladder tumor. None of these 14 specimens tested had a positive telomerase activity with our assay (Fig. 3 and Table 1) . In particular, four patients with benign and one with malignant prostate disease, all of whom presented with hematuria, were found to be negative for telomerase activity (Table 1) . Among the other patients without bladder cancer included in our study, one patient presented with hematuria caused by a distal ureteral stone, one patient was being treated with BCG and had a negative cytology, one patient had stricture disease resulting from gonorrhea and one patient had a recent history of bladder tumors (TC49) . It should be noted that in this group of patients, there were no false positive results in patients with infections, stones, or benign prostatic hyperplasia. Table 1: Results of telomerase assay in patients without bladder cancer

Positive telomerase expression in patients with bladder cancer: Exfoliated cells from voided urine samples of twenty three patients with various grades of bladder cancer were tested for telomerase activity (see Table 2 and Figure 4) . In particular, in samples

15, 23, 26, 33, 41 and 43, the patient exhibited a negative cytology but tested positive in the assay for telomerase activity. Patient #23, for example, subse¬ quently had a positive preoperative cystoscopy which demonstrated two small papillary lesions. Pathology results showed that these lesions were of grade 1 bladder cancer (Table 2) . In four patients (numbers

16, 17, 19 and 22) , testing for telomerase activity would have avoided an unnecessary preoperative cystoscopy. All (4/4) grade I tumors and 87.5% (7/8) of grade II tumors were diagnosed by the telomerase assay.

In the 23 patients with bladder cancer studied, only three (3/23) false negative results were observed, compared with six out of thirteen (6/13) false nega¬ tives found by cytological examination alone. Since each false negative result is followed up by pre¬ operative cystoscopy (which is not performed when a positive result is obtained) , the low rate of false positives associated with the telomerase assay avoids a substantial number of unnecessary cystoscopies, invasive procedures with a low but nonetheless significant morbidity.

Table 2 : Results of telomerase assay in patients with bladder cancer

sample # cytology findings telomerase results pathology

15 neg pos Grade II

16 pos Grade I

17 pos Grade I

18 pos pos Grade III

19 pos Grade III

21 pos pos Grade III inv.

22 pos Grade III

23 neg pos Grade I

26 neg pos Grade II

27 pos pos Grade II

28 pos pos Grade III inv.

29 neg Grade III

33 neg pos Grade I

34 pos os Grade II

35 pos Grade II

37 neg Grade II

39 pos no specimen

41 neg pos Grade III

42 neg Grade III

43 neg pos Grade II

44 pos pos Grade III inv.

50 pos Low grade

51 pos pos CIS

6.3. Discussion

The use of exfoliated cells from voided urine as a screening process for bladder cancer was first suggested by Oppenheimer in Germany (Gamarra and Zein, 1984, Supplement to Urology 23(3) :23) . Papanicolaou and Marshall introduced urine cytology as a screening test for bladder cancer in 1945 (Papanicolaou and Marshall, 1945, Science 101 :519) . The criteria upon which the diagnosis of bladder cancer is made include but are not limited to the presence of an abnormal nucleus, changes in the cytoplasm, and alteration in cell size and form. They claimed that neoplasms of the bladder desquamate to such a proportion that diagnosis of tumor presence can be made based on sediment smears. Cytology could lend itself to being an excellent test for screening because it is simple, non-invasive, and inexpensive.

However, experience has borne out the limitations of urinary cytology, especially in low grade tumors where the sensitivity varies from 0 to 73% (Rabb et al., 1994, Cancer 74_.:1621) . Raab et al performed stepwise logistical regression analysis on various cytologic variables to try to identify key criteria for diagnosing low grade transitional cell carcinomas via cytology alone. They identified 3 features: increased nuclear/cytoplasm ratio, irregular nuclear borders, and cytoplasmic homogenicity. If all these features are present, they claim that cytology could yield a sensi¬ tivity of 45% and a specificity of 98% (Rabb et al . , 1994, Cancer 74:1621) . However, if only 2 of these features are used, the sensitivity increased to 85%, but the specificity declines (Rabb et al . , 1994, Cancer 24:1621) .

Several studies confirmed the low sensitivity of exfoliated cytology alone. U iker et al . screened 3,609 patients, 83 had positive cytologies, of whom only 22 actually had bladder tumors (Umiker, 1964, Sy p Diagn Accur Cytolog Techniq 8.: 166) . Rife screened 3500 patients, of which 106 were found to have positive cytologies, and only 69 had bladder tumors (Rife et al., 1979, Symp Advan Lab Intraoper Diagn Techniq 6_:599) .

Because of the problem with sensitivity and specificity, Murphy et al . published a report describ¬ ing the appropriate criteria for the determination of bladder cancer (Murphy et al. , 1984, Cancer 53 :1555) . In this report, the authors were able to diagnose 76% of grade 1 and 100% of grade II and grade III bladder cancer lesions. Furthermore, they were able to diagnose 100% of carcinoma-in-situ (Murphy et al., 1984, Cancer 5J3:1555) . Their false positive rate was 10 to 14% for all tumors combined (Murphy et al . , 1984, Cancer 5J.:1555) .

Despite these improvements, the majority of investigators agree that urinary cytology is limited in its usefulness in detecting low grade bladder tumors. Furthermore, conditions that could contribute to false positive results (atypia) are hyperplastic lesions, radiation effects, infections, and urinary stones.

Trott and Edwards compared bladder washing specimens with voided urine cytology (Trott and Edwards, 1973, J. Urol. 110:664) . The theory behind the study was that low grade lesions slough off very few cells into the urine. Fresh bladder washing may increase the number of cells per volume and may make the diagnosis more accurate. Out of 160 patients that were tested, 22 had positive cytologies in the bladder washing specimens, and another 6 had "suspicion of bladder cancer" . On cystoscopy, only 9 patients had true lesions. The other 19 patients had either chronic cystitis, changes due to radiation, or healthy tissue (Trott and Edwards, 1973, J. Urol. 110:664) .

Flow cytometry is an alternative to urine cytology. It measures DNA content m an objective and quantitative manner. Neoplastic cells display nuclear enlargement and hyperchromatism, reflecting an increased DNA conten . Samples are compared to normal control cells and the amount of DNA is displayed as a histogram as diploid, tetraploid, or aneuploid (Badalament et al . , 1987, Cancer £0:1423) .

Flow cytometry can be performed using voided urine samples. Reports have shown that flow cytometry will detect approximately 80% of all bladder cancers. For example, Badalament et al . (1987, Cancer £0:1423) showed that when bladder washings, from 70 patients with bladder cancer confirmed via cystoscopy, were analyzed by flow cytometry, 83% of the bladder cancers were detected. As with cytology, the detection rates are better for lesions of higher grade and stage: grade 1 papillomas will be detected in only 50% of patients; Ta, Tis, and invasive lesions in approxi¬ mately 82%, 89% and 90% of patients (Badalament et al. , 1988, Sem Urol £:22) . Newer techniques to identify tumor cells in exfoliated cells include the use of monoclonal antibodies (Long, 1995, Infect Urol 8.:103) . The use of a new monoclonal antibody, 486P3-12 was associated with a sensitivity at least twice that of conventional cytology (90% versus 43%) (Huland et al . , 1987, J Urol 137:654; Walker et al. , 1989, J Urol 14_2:1578) . As with cytology, studies have shown good results for high grade lesions, but the diagnosis of low grade lesions continues to be a problem. The above results, which use telomerase activity as a marker for the presence of tumor cells, show higher sensitivity and specificity than any of the other current assays. Regardless of the conditions that may result in hematuria, the telomerase activity (using the TRAP assay) bears a strong positive correla¬ tion with the presence of tumor cells. The number of cells and the method of obtaining the specimen used in our assays were similar to those employed in voided urine cytology studies. In particular, the diagnostic yield of the telomerase assay for early grade tumors far exceeds any known non-invasive methods of tumor detection.

With as few as 200 tumor cells present in any volume of urine, we were able to detect the presence of telomerase activity (Fig. 1 and Fig. 2) . All tumor grades were found to express telomerase activity (Table 2 and Fig. 4) . All four patients with grade 1 disease had a positive telomerase activity in their exfoliated cells (Table 2 and Fig. 4) . Furthermore, in several samples, we were able to detect the presence of telomerase activity despite a negative urinary cytology result (Table 2 and Fig. 4; 50% for cytology versus 100% for telomerase) .

The specificity of the telomerase activity by the TRAP assay is illustrated in patients with non-cancer causing hematuria. Patients with stone disease, benign stricture disease, benign prostatic hyperplasia, and inflammation all demonstrated negative telomerase activity in their exfoliated cells (Table 1 and Fig. 3) .

From a user perspective, the TRAP assay for telomerase activity is completely objective. The results are shown on polyacrylamide gels with no subjective interpretations (see Figs. 1, 2, 3 and 4) . Various publications are cited herein, which are hereby incorporated by reference in their entireties. SEQUENCE LISTING

(1) GENERAL INFORMATION:

(i) APPLICANTS: MOUNT SINAI SCHOOL OF MEDICINE OF

THE CITY UNIVERSITY OF NEW YORK (ii) TITLE OF INVENTION: DETECTION OF HUMAN BLADDER CANCER CELLS IN URINE SAMPLES BY ASSAYING FOR THE PRESENCE OF TELOMERASE ACTIVITY (iii) NUMBER OF SEQUENCES: 3 (iv) CORRESPONDENCE ADDRESS: (A) ADDRESSEE: Lisa B. Kole

Brumbaugh, Graves, Donohue & Raymond

(B) STREET: 30 Rockefeller Plaza

(C) CITY: New York (D) STATE: New York

(E) COUNTRY: USA

(F) ZIP: 10112

(v) COMPUTER READABLE FORM:

(A) MEDIUM TYPE: Diskette - 5.25 inch, 360 Kb (B) COMPUTER: IBM XT Compatible

(C) OPERATING SYSTEM: MS DOS

(D) SOFTWARE: WORD PERFECT 5.1 (vi) CURRENT APPLICATION DATA:

(A) APPLICATION NUMBER: 08/622,743 (B) FILING DATE: March 27, 1996

(C) CLASSIFICATION:

(vii) PRIOR APPLICATION DATA:

(A) APPLICATION NUMBER:

(B) FILING DATE: (A) APPLICATION NUMBER:

(B) FILING DATE:

(2) INFORMATION FOR SEQUENCE ID NO:l: (i) SEQUENCE CHARACTERISTICS:

(A) LENGTH: 18 Nucleotides (B) TYPE: Nucleic Acid

(C) STRANDEDNESS: Single

(D) TOPOLOGY: Linear (ii) MOLECULE TYPE: DNA (iii) HYPOTHETICAL: (iv) ANTI-SENSE: No (vii) IMMEDIATE SOURCE:

(A) (xi) SEQUENCE DESCRIPTION: SEQ ID NO: 1 AATCCGTCGA GCAGAGTT (2) INFORMATION FOR SEQUENCE ID NO: 2

(i) SEQUENCE CHARACTERISTIC:

(A) LENGTH: 24 Nucleotides

(B) TYPE: Nucleic Acid

(C) STRANDEDNESS: Single (D) TOPOLOGY: Linear

(ii) MOLECULE TYPE DNA (iii) HYPOTHETICAL: (iv) ANTI-SENSE: No (vi) IMMEDIATE SOURCE: (A)

(xi) SEQUENCE DESCRIPTION: SEQ ID NO: 2 CCCTTACCCT TACCCTTACC CTAA

(2) INFORMATION FOR SEQUENCE ID NO:3 (i) SEQUENCE CHARACTERISTIC: (A) LENGTH: 6 Nucleotides

(B) TYPE: Nucleic Acid

(C) STRANDEDNESS: Single

(D) TOPOLOGY: Linear (ii) MOLECULE TYPE DNA (iii) HYPOTHETICAL:

(iv) ANTI-SENSE: No (vi) IMMEDIATE SOURCE:

(A) (xi) SEQUENCE DESCRIPTION: SEQ ID NO:3 CCCTTA

Claims

1. A method for detecting bladder cancer cells in a urine sample of a subject in need of such evaluation, wherein an increase in the level of telomerase activity relative to control levels has a positive correlation with the presence of bladder cancer cells.

2. A method for detecting bladder cancer cells in a urine sample of a subject in need of such evaluation, comprising the following steps: (i) collecting exfoliated cells from the urine sample; (ii) substantially removing red blood cells, white blood cells, necrotic tissue and cellular debris from the sample; and (iii) measuring the amount of telomerase activity in the sample; wherein an increase in the level of telomerase activity relative to control levels has a positive correlation with the presence of bladder cancer cells.

3. A method for detecting bladder cancer cells in a urine sample of a subject in need of such evaluation, comprising the following steps: (i) collecting exfoliated cells from the urine sample; (ii) substantially removing red blood cells, white blood cells, necrotic tissue and cellular debris from the sample; and (iii) measuring the amount of telomerase activity in the sample by a primer extension protocol comprising combining a portion of the sample with an oligonucleotide substrate under reaction conditions which result in telomeric extension of the oligonucleotide substrate if telomerase enzyme is present, and then detecting and measuring the level of any extended oligonucleotides produced; wherein an increase in the level of telomerase activity relative to control levels has a positive correlation with the presence of bladder cancer cells.

The method of claim 3 , wherein the number of extended oligonucleotides is amplified by a polymerase chain reaction.