Genetic Detection Of Bladder Cancer By Microsatellite Analysis Of P16, P53 And VHL Tumor Suppressor Genes

PURPOSE: To a highly sensitive noninvasive befitting Chinese people and early technique for the detection of TCC, We investigated the incidence of loss of heterozygosity (LOH) from patients with TCC by microsatellite analysis of p16, p53 and VHL tumor suppressor genes (TSG). Meanwhile, revealed its relativities with various grade and stage tumor. Also analysed the genetic mechanism of microsatellite DNA (MS) and LOH.Methods: 50 TCC biopsy specimens and corresponding control of normal bladder mucous membrane samples were collected randomly. In 40 cases, relevant cytological urine specimens were also available. 6 microsatellite markers located on p16, p53 and VHL TSG were used to analyze microsatellite alternation. The extraction of DNA was using phenol-choroform-isopentanol method. We performed PCR amplification according to foresaid marker primers and denatured polyacrylamide gel electrophoresis. Silver stained for observing the result. In 40 of 50 patients, the cytologic analysis was also performed, and compared the sensitivity with microsatellite analysis. Allstatistical tests were two-side and double-blind. Chi-square and Fisher exact tests were used to evaluate the samples rates. The statistical standard is P<0.05. RESULTS:1. LOH was detected in 45(90%) of 50 tumor biopsy specimens in at least 1 microsatellite marker; in 35(87.5%) of 40 urine samples. Positive case is 35(62.5%) of 40 patients in corresponding urine pathology tests. Majority is the high stage and grade.2. Of 6 MS marker, the positive rate of LOH from high to low is D9s259 (76.3%) , D9s270 (65.7%), D17s786 (50.0%), D3sl2 84 (41.7%), D3sl038 (41.2) , D17s379 (40.5%). LOH is irrelative with the stage and grade in D9s259 , D9s270 , D3sl038 , D17s786. So they may be used in diagnosis of primary tumors. LOH of D3sl2 84, D17s379 mainly represented in high stage and grade, may become a tool to detect prognosis of advanced TCC. Our result somewhat differs to foreign reports. It demonstrates ethnic differences at genetic level and etiology between Chinese and the western.3.In urine samples, MS analysis is more sensitive than cytological detection, especially to early tumor.CONCLUSION: Our results suggest that MS analysis represents a novel, potentially useful, sensitive, noninvasive clinical tool to TCC.