Urothelial Cancer Screening Differentially Expressed Proteins In Urine

Background:Bladder cancer (BC) is the most common urinary tumor which has a gradually increased incidence year by year. What’s more, it is not infrequent to see some young people suffering from the disease. The causes which lead to bladder cancer are complex. There are some of them have been recognized and studied:long-term exposure to aromatic amines chemicals, local stimulation of bladder, the abuse of certain drugs, pelvic radiotherapy, smoking and so on. At the same time, some oncogene like ras, HER-2/neu, c-myc and some suppressor gene like p53, RBI have been discovered in the research of gene-level. All of them could be the probable causes of bladder cancer. The most common initial symptom of bladder cancer is usually asymptomatic gross hematuria which could become from intermittent to continuity because of the increase and infiltration of tumor. At present, a wide range of diagnose ways of bladder cancer are used, but none of them is perfect. Urine cytology test couldn’t find out low-level tumor and its result is usually highly dependent on the technical level of the examiner. Cystoscope could not only observe the shape and size of tumor directly, but also be an easy way to take biopsy. But it couldn’t be done without complete equipment. Meanwhile the cystoscope brings too much pain to the patients. Several common imaging methods share the same advantage which is non-invasive, but none of them could find small or flat tumor easily. In the search of tumor markers, NMP22, SurVivin, UBC, telomerase, p27, VEGF and several others were found to be useful in the diagnose of bladder cancer. But there is still no public accepted standard.With the development and maturity of proteomics technology and its unique advantages in the study of tumor, some researchers have already found their new ways to pick out the tumor markers of bladder cancer. CRT, UBC1-5, keratin, MRP8, MRP14and some other markers which have relationship with bladder cancer have already been found. It is said that there would surely be a bright future in the search of BC tumor markers with the help of proteomics technology. In this study, SELDI technology was used to find some markers which could be useful in the early stage diagnose of bladder cancer. And the new way was supposed to be non-invasive.Objective:1. To find out the special protein peaks in the urine of bladder cancer patients or control group members. 2. To build a diagnosis screening model of bladder cancer with the differences between the protein peaks of bladder cancer patients and control group members.Methods:1. Second morning urine samples of the patients with bladder cancer, other non-tumor diseases of urinary system and healthy people were collected.2. H4hydrophobic chips and SELDI machine which were produced by BIORAD company of America were used to determinate the protein molecular peaks of all urine samples. Ciphergen Protein Software3.2.1was used to display all of the captured protein peaks.3. Laboratory data was analyzed by SPSS16.0software, and P<0.05was considered to indicate statistical significance.4. BPS was used to do cluster analysis work and build the diagnosis screening model of bladder cancer.Results:1. Clinical features of bladder cancer patients:38bladder cancer patients were recruited. The range of age was from35to88. The median age of patients was68.5years, with73.7%patients were older than60years. The number of males was27, with the females’11. The high-level tumor group included17patients, while low-level group included19ones. There were2patients’ pathological levels were uncertain.2. The result provided by SELDI machine:set the minimum protein molecular weight which could be displayed to1000, the maximal to50000, S/N≥5, the min peak rate to5%. There were214peaks could be found.3. The result analyzed by SPSS16.0software:after the test of normality,90peaks were classified as normal distribution group, while124other peaks as non-normal distribution. T-test picked out6protein peaks from the normal distribution group, which molecular weight were1712.263,1896.238,2228.543,2464.589,2977.719and4792.879. Mann-Whitney U analysis picked out12protein peaks from the non-normal distribution group, which molecular weight were1877.678,2212.175,2578.946,2847.638,3249.263,3385.764,4129.112,13304.09,15108.4,16652.69,22197.04and33354.89. All of the18protein peaks were considered to indicate statistical significance with P<0.05.4. The result of diagnosis screening model provided by BPS:when2464.589,1896.238,1877.678,2977.719and2847.638were used as select nodes to build the diagnosis screening model, the cancer group and control group could be distinguished best.5. The result of figure analysis:the protein M=2464.589was used as an example. Both the linear and gel figures could show visible differences between cancer and control groups.Conclusions:1. H4hydrophobic chip is quite useful to capture the protein molecule in the urine samples, especially the ones with low molecular weight.2. The differences of protein peaks between cancer and control groups are considered to indicate statistical significance and could be used to build a diagnosis screening model of bladder cancer.