| Background Malignancy imperils human beings seriously. Invasion and metastasis not only owe great degree to the death of patients with malignancy, but also are the typical biological characteristics of malignancy. So invasion and metastasis are always the focus on the study of tumor.Bladder transitional cell carcinoma(BTCC) is the most common malignancy in urology department,with complicated and versatile biological behavior . The complexity and versatility of its biological behavior made the mechanism and prognosis becoming the focus of its study . BTCC was classified into 2 categories by professor Chang Jiwu,that is,two-class system of BTCC. Recently many researchers try to reveal the biological mechanism of BTCC: 1. To find the more reliable biological marker so as to diagnose earlier and judge the prognosis precisely. 2. To explore the metastasis mechanism of BTCC so as to take the personal therapy and increase the distant survival.A new metastasis suppressor genes CD9/MRP-1 has been found recently to be with many tumors.CD9 is one kind of adhesion molecule, expressioned in endepidermis derived cells, and is recently proved to be related to the infiltrating and metastasis of many kinds of tumor cells.Many experiments proved that positive rate of CD9 was significantly low in malignant tumors than in the normal tissues and its expression decreased with the advance of tumor grade and tumor stage.We presume that the decrease of express of CD9 in high malignant BTCC may be accompanied by mutation of CD9 gene.That may be a new advancingmechanism ofBTCC.Objectiverln order to clarify the two categories of BTCC on molecular biological characters,firstly,we study the expression of CD9 and MMP-2 (as control) in bladder transitional cell carcinoma and normal bladder mucosas by means of immunohistochemistry (IHC). Secondly, we study the mutation of CD9 gene in bladder transitional cell carcinoma (Grade III)by the means of RT-PCR and DNA sequencing. Therefore,We can judge the influence of CD9 on biological behavior of BTCC. we performed the experimentation described below.Methods:Expriment IImmunohistochemistry was carried out to detect the expression of MMP-2 and CD9 in 52 cases of bladder transitional cell carcinoma and 10 normal bladder mucosas. The correlations between the expression results and tumor pathological grades,clinical stages were all considerated. Expriment IIFrozen slices were made to judge the expression of CD9 in 15 cases of BTCC (Grade III) . RNA was abstracted from those whose expression of CD9 is weakened or negative ,that is 11 cases,then RT-PCR was performed to get cDNA ,finally DNA sequencing was carried out aiming at the mutation of CD9 gene. Results:Expriment IPositive rate of CD9 was significantly low in BTCC patients(78.1%) thanin the normal mucosas(100%). Furthermore, its expression decreased with the advance of tumor grade and tumor stage.The expression of the MMP-2 in BTCC shows 67.3 % positive and has significance compare with the normal mucous and its expression increased with the advance of tumor grade and tumor stage.The Sperman analysis show the expression of CD9 and MMP-2 has a negtive correlation.Expriment IIImmunohistochemistry of frozen slices also showed that positive rate of CD9 was significantly low in BTCC patients .In one cases of BTCC (Grade III),it exhibited C-to-T and A-to-T transitions at nucleotides 298 and 554 respectively and the latter resulted in changing of the coded amino acid (NO 148 in 228) : tyrosine(Tyr,Y) to phenylalanine(Phe,F), which leaded to changing of the immunogenicity. Conclusion:Positive rate of CD9 was significantly low in BTCC patients than in the normal mucosas and its expression decreased with the advance of tumor grade and tumor stage. In BTCC (Grade III),gene mutation occurred .It provide a new molecular mechanism of initiation and progression of bladder cancer and might be a molecular marker and immuno-therapeutic target for high malignant bladder cancer (class II in the suggested two-class system).
|
PDF Full Text Request