Cytological study on aptamer selection for bladder cancer through CELL-SELEX / 医学研究生学报

ObjectiveThe methods based on bladder cancer markers which could be applied to early diagnosis and postoperative recurrence monitoring of bladder cancer were current research hotspots. This study aims to screen aptamers that specifically recognize human bladder cancer cell lines (EJ, T24, BIU87) through cell-based systematic evolution of ligand by exponential enrichment (CELL-SELEX).MethodsFor CELL-SELEX screening, bladder cancer cell lines EJ, T24, and BIU87 were used as positive control cells. HCV 29 (human normal urothelial cell line), 293T (human embryonic kidney cell line), huh7 (human hepatocellular carcinoma cell line) were used as negative control cells. PCR upstream primers were labeled with FITC, downstream primer was labeled with Biotin. ssDNA fragments collected from each round were amplified by PCR, and the amplified product was then purified using a DNA purification Kit. The biotin-streptavidin magnetic separation methods were used to isolate the PCR product to obtain secondary FITC-ssDNA for the next CELL-SELEX round. The screening process was monitored by flow cytometry. ssDNA pool with the highest binding rates to bladder cancer cell lines(EJ, T24, and BIU87) was selected to PCR amplification, product purification, molecular cloning, and sequencing. According to the sequencing results, the secondary structure of the aptamer was pre-simulated by Dnaman software. Aptamer labeled with FITC was synthesized in vitro, flow cytometry was used to detect the binding rate of the aptamer to bladder cancer cell lins (EJ, T24 and BIU87).ResultsWith the advance of the CELL-SELEX process, the binding rate of FITC-ssDNA to bladder cancer cell lins (EJ, T24, and BIU87) increased gradually. By the 15th round, the binding rate of FITC-ssDNA to EJ cells reached the highest level. The apt1 had the highest enrichment among the 15th round ssDNA pool. By the 18th round, the binding rate of FITC-ssDNA to T24 or BIU87 cells reached the highest level. The apt2 and apt3 had the highest enrichment among the 18th round ssDNA pool. DNA structure prediction showed that the secondary structure of apt1, apt2, and apt3 was mainly stem-loop structure. Flow cytometry showed that the highest binding rate was FITC-apt1 to EJ cells, FITC-apt2 to T24 cells, and FITC-apt3 to BIU87 cells, respectively. There is no significant combination between these aptamers with the negative cells.ConclusionIn this study, three kinds of aptamers with high specificity for bladder cancer cell lines were successfully screened by CELL-SELEX. The apt1 can specifically recognize EJ cells, apt2 can specifically recognize T24 cells and apt3 can specifically recognize BIU87 cells, all of which provide experimental evidence for early diagnosis and targeted therapy technology research of bladder cancer.

Characterization of a novel transplantable orthotopic nude mouse model with xenografted human bladder transitional cell tumor (BIU-87) / 中华肿瘤杂志

<p><b>OBJECTIVE</b>A mouse model of orthotopic bladder cancer simulating its human counterpart is of great importance in preclinical evaluation of new treatment modalities such as immunotxin therapy. The aim of the present study is to establish a novel nude mouse model with xenografted human bladder cancer.</p><p><b>METHODS</b>Single cell suspension of an established human bladder transitional cell carcinoma (TCC) cell line BIU-87 was instilled into nude mouse bladders which were pretreated with mild acid washing. The tumor growth in mouse bladder was assessed weekly by magnetic resonance imaging (MRI). At intervals following implantation and MRI tumor detection, the animals were sacrificed for necropsy, histological examination and immunocytochemical studies.</p><p><b>RESULTS</b>The overall tumor establishment was 92.9% (52/56 mice) at 7 - 36 days, while in the subgroup of animals sacrificed at 12 - 13 days, 40 out of 42 animals (95.2%) developed TCC, the majority of which was superficial. The tumor stages were assessed by gross and histopathology. Histological examination confirmed the presence of grade II - III TCC. Immunocytochemistry confirmed that the tumor model maintained the biological and immunological features of BIU-87 cells. The changes seen on MRI images well correlated with the extent of tumor invasion identified by histology. Carcinoma in situ could be detected histologically at 7 - 9 days post-inoculation and progressed into papillary or invasive tumors thereafter.</p><p><b>CONCLUSION</b>The orthotopic BIU-87 TCC model in nude mice is highly reproducible and is ideal for preclinical studies on experimental intravesical therapies.</p>

Comparison of clinical efficacy of orthotopic ileal neobladder versus orthotopic sigmoid neobladder / 中华泌尿外科杂志

Objective To compare the clinical efficacy of orthotopic ileal neobladder versus ortho- topic sigmoid neobladder.Methods The data of 96 patients who had undergone orthotopic ileal neoblad- der and 68 patients who had undergone orthotopic sigmoid neobladder were retrospectively analyzed.The perioperative condition,urinary continence,urodynamics,and pouch-related complications were compared between the 2 groups.Results Of all the 164 patients,12(7.3%)were lost to follow-up.The mean fol- low-up was 46(2-86)months in orthotopic ileal neobladder group,and 42(4-78)months in orthotopic sigmoid neobladder group.There was no significant difference in intraoperative blood loss and postoperative urinary continence between the 2 approaches(P＞0.05).However,compared with sigmoid neobladder group,ileal neobladder group had longer operative time and postoperative recovery time,and got a bigger pouch(P＜0.05).The early and late pouch-related complication rates of ileal neohladder group were 16. 7% and 29.2%,which were higher than those of sigmoid neobladder group.During the follow-up,tumor recurred in 3 cases of ileal neobladder group,but none in sigmoid neobladder group.Conclusions Ortho- topic ileal neobladder and sigmoid neobladder are similar in operative difficulties,and both can achieve satis- factory clinical results.Compared with ileal neobladder,sigmoid neobladder has shorter operative time, quicker recovery and lower rate of pouch-related complications,thus is a preferred procedure.