Effect of CD40 blockade on acute renal graft rejection in rats / 南方医科大学学报

<p><b>OBJECTIVE</b>To explore the effect of CD40 blockade in suppressing acute rejection of renal graft in rats.</p><p><b>METHODS</b>With Wistar rats as the donor and male SD rats as the recipients, rat models of acute renal graft rejection was established. The rat models were divided into therapy group and control group, and in the former group, CD40 ligand (CD40L) monoclonal antibody was injected daily for 4 consecutive days starting on the next day following kidney transplantation. On day 5 after the transplantation, the renal graft was harvested for histological examination, and graft rejection was evaluated semiquantitatively.</p><p><b>RESULTS</b>The mean semiquantitative score of the renal graft was 0.63∓0.52 in the therapy group, significantly lower than that of the control group (3.72∓1.48, P<0.05).</p><p><b>CONCLUSION</b>CD40L monoclonal antibody can inhibit acute renal graft in rats.</p>

A simple and efficient method for establishing a mouse model of orthotopic MB49 bladder cancer / 南方医科大学学报

<p><b>OBJECTIVE</b>To establish a simple and efficient method for establishing a mouse model of orthotopic superficial bladder cancer.</p><p><b>METHODS</b>C57BL/6 mice were anesthetized with sodium pentobarbital and catheterized with modified IV catheter (24 G). The mice were intravesically pretreated with HCl and then with NaOH, and after washing the bladders with phosphate-buffered saline (PBS), 100 microl (1 x 10(7)) MB49 cells were infused and allowed to incubate in the bladder for 2 h followed intravesical mitomycin C (MMC) administration. The tumor formation rate, survival, gross hematuria, and bladder weight were determined as the outcome variables, and the pathology of the bladders was observed.</p><p><b>RESULTS</b>Instillation of MB49 tumor cells resulted in a tumor formation rates of 100% in all the pretreated groups while 0% in the control group without pretreatment. MMC significantly reduced the bladder weight as compared to PBS.</p><p><b>CONCLUSION</b>We have successfully established a stable, reproducible, and reliable orthotopic bladder cancer model in mice.</p>

Effect of adenovirus-mediated TK/GCV gene therapy in combination with TNF-alpha against murine bladder cancer cells in vitro / 南方医科大学学报

<p><b>OBJECTIVE</b>To investigate the cell-killing effect of adenovirus-mediated TK-ganciclovir (GCV) gene therapy in combination with tumor necrosis factor-alpha (TNF-alpha) against murine bladder carcinoma cells in vitro.</p><p><b>METHODS</b>Murine bladder carcinoma MB49 cells were transfected with the adenoviral vector containing TK gene and green fluorescent protein (GFP) gene. The transfection efficiency was observed and the TK gene expression in the transfected cells was detected by RT-PCR. The survival rate of MB49 cells in response to TNF-alpha treatment and that of the TK gene-transfected cells after treatment with GCV and GCV+TNF-alpha were determined by MTT assay. The apoptosis of the cells after the treatments was analyzed by flow cytometry.</p><p><b>RESULTS</b>In cells transfected with TK gene, the cell inhibition rate increased gradually with the increment of GCV and TNF-alpha concentration. GCV in combination with TNF-alpha resulted in significantly increased killing efficiency of the cells as compared with GCV or TNF-alpha treatment alone, and the effect of the combined treatment was enhanced as the TNF-alpha concentration increased. GCV treatment (50 microg/ml) alone produced a cell killing rate of (24.39-/+1.10)%, and when combined with 5 microg/ml TNF-alpha, the rate was increased to (40.05-/+0.97) %, and further to (65.47-/+0.67) % when TNF-alpha concentration increased to 20 microg/ml. Flow cytometry revealed obvious apoptosis of the cells 8 h after treatments with TK/GCV, TNF-alpha, or TK/GCV+TNF-alpha, and the combined treatment resulted in the highest cell apoptotic rate.</p><p><b>CONCLUSION</b>TK/GCV in combination with TNF-alpha can enhance the effect of suicide gene therapy against murine bladder carcinoma cells and effectively induce apoptosis of the cells.</p>

Toxic effects of CD-TK double suicidal gene system against prostate carcinoma cells / 南方医科大学学报

<p><b>OBJECTIVE</b>To evaluate the toxic effects of the CD-TK fusion gene systems against prostate carcinoma cell line RM-1 for assessing the value of suicidal gene therapy for prostate carcinoma.</p><p><b>METHODS</b>CD-TK fusion gene and green fluorescent protein (GFP) gene were transfected into RM-1 cells through adenovirus vectors. RT-PCR was used to demonstrate successful transfection and transcription of the suicidal genes. The toxic effects of 5-FC and GCV used alone or in combination on the transfected cells were observed by MTT assay, with the non-transfected RM-1 cells serving as control.</p><p><b>RESULTS</b>Cytotoxic activity of CD/5-FC and TK/GCV systems against RM-1 cells was observed, and combined treatment with the two drugs resulted in significantly lowered survival of CD-TK-expressing cells (P<0.05). After exposure to 5-FC and GCV for 72 h, the survival rate of the transfected cells decreased to 71.56% and 47.27%, respectively, and their combined use resulted in a survival rate as low as 18.46%.</p><p><b>CONCLUSION</b>CD-TK fusion double suicidal gene system can produce significantly stronger toxic effect against RM-1 cells in vitro than either of suicidal genes.</p>