p53蛋白在联苯胺接触人群和膀胱癌患者血清中的表达

目的研究职业性联苯胺接触者和膀胱癌患者突变型p53蛋白的表达。方法用免疫PCR法测定职业性联苯胺接触人群和膀胱癌患者血中突变型p53蛋白,用巴氏分级法对尿脱落细胞进行分级。结果随着联苯胺接触强度指数的增高,人群突变型p53蛋白的阳性率不断增加,膀胱癌患者组突变型p53蛋白的阳性率(83.3%)高于接触强度指数1组(33.3%)。PCR扩增条带经扫描积分后,膀胱癌患者组和接触强度指数2组的平均扫描积分(24016.11±2979.99、12960.79±903.27)高于1组(9231.58±1140.74),差异有统计学意义(P<0.01,P<0.05)。在联苯胺接触人群的各组中以巴氏分级作为组内分层因素,接触强度指数2组中,巴氏2、3级层PCR扩增条带平均扫描积分(12960.79±903.27、13612.78±1697.38)高于1级层(9231.58±1140.74),差异有统计学意义(P<0.05)。接触强度指数3组中,巴氏3级层的突变型p53蛋白的阳性率(46.9%)高于1级层(33.3%),差异有统计学意义(P<0.05)。结论在联苯胺接触强度较低的范围内,随着接触强度的增加,接触工人血清中p53突变蛋白的阳性表达不但更频繁,而且更加强烈;但接触强度超过了这个范围,工人血中p53突变蛋白的阳性率以及表达量将不再随着接触强度的上升而增高,而尿脱落细胞病变程度在联苯胺接触强度较高的情况下与p53基因突变率

Expression of protein p53 in workers occupationally exposed to benzidine and bladder cancer patients

OBJECTIVE: To study expression of mutant p53 protein in workers occupationally exposed to benzidine and bladder cancer patients. METHODS: Mutant p53 protein in serum from the workers occupationally exposed to benzidine and bladder cancer patients were determined with Immuno-PCR, while exfoliated urothelial cells in the urine samples were classified with Papanicolau grading. RESULTS: Positive rate of mutant p53 protein increased with the exposed intensity index in workers occupationally exposed to benzidine. The positive rate of mutant p53 protein in bladder cancer patients (83.3%) was significantly higher than that in the group 1 of exposed intensity index. The average scanning integrals of PCR amplified band in the group of bladder cancer patients and group 2 of exposed intensity index were both higher than that in the group 1 significantly. Workers in the groups of different exposed intensity indices were further stratified according to Papanicolau grades. In the group 2 of exposed intensity index, the average scanning integrals of PCR amplified band in the stratum of Papanicolau grade II and III were significantly higher than that in the strata of Papanicolau grade I. And in the group 3 of exposed intensity index, the positive rate of mutant p53 protein in the strata of Papanicolau grade III was higher than that in the strata of Papanicolau grade I significantly. CONCLUSION: The increase of exposed intensity may not only result in the positive rate of mutant p53 protein, but also the quantity of mutant p53 protein in serum within the low range of benzidine exposure. Once the exposed intensity was beyond that spectrum, the positive rate of mutant p53 protein in serum and the average scanning integrals of PCR amplified band were no longer enhanced with the increase of exposed intensity. There was tight correlation between Papanicolau grade of exfoliated urothelial cells and the positive rate or the quantity of mutant p53 protein for the higher benzidine exposure intensity.