Immunohistochemical Study On The Expression Of Ku Porteins In The Bladder Carcinoma

Objective Ku heterodimer, which is composed of Ku70and Ku80subunits. The mainbiological function of Ku proteins is to repair injured DNA by non-homologousend-joining (NHEJ) pathway. Ku proteins are thought to play a crucial role inmaintenance of chromosomal integrity and cell survival. Recent reports suggest thatthere is a relationship between the expression of Ku proteins and the development andprogression of cancer. Bladder transitional cell carcinoma is, a common malignancyworldwide, remaining a significant health problem. Bladder cancer is the fourth mostcommon cancer in men and the ninth most common cancer in women in the UnitedStates, whereas it is the eighth, the twelfth respectively in China. And the incidence ofbladder cancer continues to rise high. Modern medical research has showed that tumoris a gene disease. When cells are attacked, such as smoking, ionizing radiation，radiomimetic agent, DNA double-strand breaks occur. If DNA repair mechanismdysfunctions, the gene expression may be changed, which leads to loss of control overthe cell cloning proliferation, which is an important mechanism of tumorigenesis. Thecrucial role Ku proteins plays in the DNA repair process, decides Ku proteins have theclosely relationship with tumorigenesis. Current studies have showed that the excessiveexpression of Ku proteins plays an important role in this process. This study is to detectand compare the Ku proteins expression ratios in non muscle-invasive bladder cancer,muscle-invasive bladder cancer and tumor-adjacent tissues using immunohistochemicalstaining technology, to confirm the correlation between the expression of Ku proteinsand the invasion of bladder carcinoma. Method Using immunohistochemical staining technology to detect and compare the Kuproteins expression levels of98cases of samples were obtained surgically bytransurethral resection of bladder (TUR-BT) or radical cystectomy in Airforce GeneralHospital of PLA from January2000to December2012. The results were analyzed bymorphometric methodology combined with the clinicopathologic profiles. Summarizethe relevant information and use the SPSS19.0statistical analysis to analyze the Kuproteins expression in non muscle-invasive bladder cancer, muscle-invasive bladdercancer and tumor-adjacent tissues.Results①The total positive expression rate of Ku proteins in all specimens was80.61%(79/98). Ku proteins are expressed both in bladder cancer and tumor-adjacenttissues, mainly distributed in the nucleus.②The positive percentage of Ku proteins ofthe non muscle-invasive bladder cancer group (89.55%,60/67) was significantly higher(P＜0.01) than that of the muscle-invasive bladder cancer group (61.29%,19/31).Morphometry demonstrated that mean optical density levels of Ku proteins of the nonmuscle-invasive bladder cancer group (4349.41±307.20) was significantly higher (P＜0.01) than that of the muscle-invasive bladder cancer group (2453.05±221.24). Therewas obviously significance (P＜0.01) respectively between the carcinoma (3605.67±1024.80) and the bladder tissues adjacent to the carcinoma (396.84±60.24).Conclusion Ku proteins are expressed both in bladder cancer and tumor-adjacenttissues. Ku proteins expressing ratio is significantly increased in bladder tissues than intumor-adjacent tissues. It showed that increasing expression of Ku proteins may be oneimportant mechanism of earlier phases of bladder cancer genesis. The expression ratioof Ku proteins is significantly decreased in muscle-invasive bladder cancer, suggestingthat Ku proteins may play an important role in the progressive processes and contribute to the malignant phenotype and the processes of invasion in human bladder carcinoma.