DEK as a urine based biomarker for bladder cancer
The present invention is directed to a method of detecting DEK protein in a urine sample. Methods and compositions are provided herein for detecting and diagnosing bladder cancer by chemical-induced precipitation of urine proteins, followed by filtration-induced concentration and Western blot analysis to specifically detect DEK protein. The present method permits specific detection of DEK protein in urine as a biomarker for bladder cancer in humans.
1. A method of detecting bladder cancer in a human, comprising the steps of:
(a) obtaining a urine sample from a human suspected of bladder cancer;
(b) forming a precipitate from said urine sample with a chemical compound selected from the group consisting of acetone, trichloroacetic acid, ethanol, methanol/chloroform, and ammonium sulfate;
(c) re-suspending said precipitate in a polar solvent to form a solution, said solution has a final volume that is 10-50 fold less than that of said urine sample;
(d) concentrating said solution 2-10 fold by filtration; and
(e) detecting DEK-2 protein in said concentrated solution using an anti-DEK antibody in a Western blot assay,
wherein said detected DEK-2 protein consists of SEQ ID NO: 4, and the presence of said detected DEK-2 protein in said urine sample as compared to a urine sample from a healthy individual is indicative of bladder cancer in said human.
2. The method of claim 1 , wherein said chemical compound is acetone.
3. The method of claim 1 , wherein said chemical compound and said urine sample has a volume to volume ratio of 2:1.
4. The method of claim 1 , wherein said polar solvent is tri-ethanol amine.
5. The method of claim 1 , wherein said solution in step (c) has a final volume 20 fold less than that of said urine sample.
6. The method of claim 1 , wherein said concentrated solution in step (d) has a final volume 5 fold less than that of said solution.
7. The method of claim 1 , wherein said filtration is performed using a filter, said filer has a 3 kD cutoff.
8. The method of claim 1 , wherein said anti-DEK antibody is a polyclonal antibody.
9. The method of claim 1 , wherein said anti-DEK antibody is labeled with horse radish peroxidase.
10. The method of claim 1 , wherein said bladder cancer is transitional cell carcinoma.