Temsirolimus improves cytotoxic efficacy of cisplatin and gemcitabine against urinary bladder cancer cell lines

ObjectivesTo analyze the cytotoxic action of temsirolimus using 3 established human bladder cancer cell lines and to assess whether temsirolimus potentiates the anticancer activity of gemcitabine and cisplatin.MethodsTemsirolimus (500, 1,000, 2,000, and 4,000 nM), in isolation, and combined with gemcitabine (100 nM) and cisplatin (2.5 µg/ml), was given to 5637, T24, and HT1376 bladder cancer cell lines. Cell proliferation, autophagy, early apoptosis, and cell cycle distribution were analyzed after a 72-hour period. The expression of mammalian target of rapamycin baseline, Akt, and their phosphorylated forms, before and after treatment with temsirolimus, was evaluated by immunoblotting.ResultsTemsirolimus slightly decreased the bladder cancer cell proliferation in all 3 cell lines. No significant differences in the expression of mammalian target of rapamycin, Akt, and their phosphorylated forms because of temsirolimus exposure were found in the 3 cell lines. As part of a combined regime along with gemcitabine, and especially with cisplatin, there was a more pronounced antiproliferative effect. This pattern of response was similar to the other parameters analyzed (increased autophagy and apoptosis). Also, in the combined regime, an enhanced cell cycle arrest in the G0/G1 phase was observed. The non–muscle invasive 5637 bladder cancer cell line was most sensitive to both combinations.ConclusionsTemsirolimus makes a moderate contribution in terms of cell proliferation, apoptosis, and autophagy. However, it does potentiate the activity of gemcitabine and particularly cisplatin. Therefore, cisplatin- or gemcitabine-based chemotherapy regimen used in combination with temsirolimus to treat bladder cancer represents a novel and valuable treatment option, which should be tested for future studies in urinary bladder xenograft models.     

The role of cancer stem cells in immunotherapy for bladder cancer: An in vitro study

ObjectiveBladder cancer is characterized by frequent recurrence and progression. CD44+ cancer stem cells (CSCs) might be one of the main reasons for recurrence. Although Bacillus Calmette Guerin (BCG) has become a gold standard immunotherapy, after treatment recurrence frequently occur. Based on this knowledge, the aim of this study was to evaluate the changes in cytokine and chemokine expressions in bladder cancer and CSCs cultures in vitro with BCG only and in combination with IL2 and lymphocyte (MNCs) applications.Material and methodsIn this study, 3 cell lines of human bladder cancer cells with different characteristics (T24, 5637, and JMSU-1) and CD44+ bladder CSCs isolated by magnetic bead isolation (Miltenyl Magtech) were used. Bladder cancer cell lines and bladder CSCs in complete medium were cultured under humidified conditions of 37°C temperature in 5% CO₂. BCG only and its combination with IL2 and MNCs were applied to bladder cancer cell lines and bladder CSCs for 24, 48, and 72 hours. Annexin V-PI was used to detect the percentages of apoptotic and necrotic cells in treatment groups and control groups. After treatments, total RNAs were isolated and converted to cDNA for each group and controls. Quantitative fold changes in terms of gene expression were measured by RT2–PCR array and fold changes for expression levels of genes were compared among groups. Eighty-four genes were analyzed in standard array of chemokines and cytokines (Biorad).ResultsBCG treatment with 7.32 µg/ml dose alone and in combination with IL2 (1000 IU/ml) and MNCs (1000 cells/ml) were found to be most effective on bladder cancer cells. When BCG and its combinations were applied to CSCs of the 3 cell lines, BCG treatment showed cytotoxic effect on CSCs as well as cancer cells. CSCs of 3 cell lines over expressed CXCL5, CCL8, CNTF, and CSF2 compared with cancer cells. Cancer cells over expressed IL6, TNSFF11, FASLG, and CXCL9 compared with CSCs. In all 3 cell lines, BCG application increased expression of CXCL5 and LTB and also decreased CCL20 and IL6. When BCG was combined with IL2 and MNCs, CXCL10, CXCL5, and IFNG were increased and CXCL12, IL6, and TNSF11 were decreased. BCG treatment of CSCs caused increases in ADIPOQ, CXCL10, and XCL1 and a decrease in CCL8. When IL2 and MNCs were combined with BCG, the expression of many cytokines and chemokines decreased.ConclusionBCG treatment changes the expression of many cytokines and chemokines in bladder cancer. The expression differs in 3 different cell lines and their CSCs. Immune modulation of each case differs from each other. The effectivity of BCG-based immunotherapy in bladder cancer on CSCs might decrease in combination with IL2. Our results indicate that recurrence after BCG treatment for bladder cancer may not occur mainly based on the CSCs hypothesis considering bladder cancer occurs at different loci of surface epithelium.     

Radiation induces<Emphasis Type="Italic"> p53</Emphasis>-dependent cell apoptosis in bladder cancer cells with wild-type-<Emphasis Type="Italic">p53</Emphasis> but not in<Emphasis Type="Italic"> p53</Emphasis>-mutated bladder cancer cells

Purpose. It has been reported in several studies that the absence in cancer cells of the p53 tumor suppressor gene, mutations of which are frequently found in bladder cancer, increases their resistance to ionizing radiation. Other studies, however, suggest that mutations of the p53 gene could increase the radiosensitivity of cancer cells, although the evidence is still inconclusive. In the present study, we investigated the relationship between p53 status and radiation response in five different bladder cancer cell lines. Materials and Methods. Five different human bladder cancer cell lines (KK47: with wt-p53, RT4: with wt-p53, T24: with mutated p53, 5637: with mutated p53, UM-UC-3: with mutated p53) were used in the study. Cells were irradiated with 0, 2, 4, 6 or 8 Gy, then trypsinized and re-plated for clonogenic survival assay, quantitative RT-PCR assay, flow-cytometry analysis and TUNEL assay. Results. The clonogenic assay demonstrated that KK47 and RT4 had significantly higher radiosensitivity than other cell lines. Quantitative RT-PCR analysis showed that radiation induced increased expression of p53, Bax, and p21 mRNA in KK47 and RT4. After irradiation, G1 cell-cycle arrest was observed in KK47 and RT4 under flow cytometry analysis, while T24, 5637, and UM-UC-3 showed an increase in the proportion of G2 cells. Increased cell apoptosis was also observed under TUNEL assay in KK47 and RT4, but not in other cell lines. Conclusions: It was demonstrated that ionizing radiation induces p53-dependent cell apoptosis in bladder cancer cells with wt-p53 but not in those with mutated p53.     

In vivo and in vitro effects of RAD001 on bladder cancer

ObjectiveTo evaluate the influence of Everolimus (RAD001) on chemically induced urothelial lesions in mice and its influence on in vitro human bladder cancer cell lines.MethodsICR male mice were given N-butyl-N-(4-hydroxybutyl) nitrosamine in drinking water for a period of 12 weeks. Subsequently, RAD001 was administered via oral gavage, for 6 weeks. At the end of the experiment, all the animals were sacrificed and tumor development was determined by means of histopathologic evaluation; mammalian target of rapamycin (mTOR) expressivity was evaluated by immunohistochemistry. Three human bladder cancer cell lines (T24, HT1376, and 5637) were treated using a range of RAD001 concentrations. MTT assay, terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL), and flow cytometry were used to assess cell proliferation, apoptosis index, and cell cycle analysis, respectively. Immunoblotting analysis of 3 cell line extracts using mTOR and Akt antibodies was performed in order to study the expression of Akt and mTOR proteins and their phosphorylated forms.ResultsThe incidence of urothelial lesions in animals treated with RAD001 was similar to those animals not treated. RAD001 did not block T24 and HT1376 cell proliferation or induce apoptosis. A reduction in cell proliferation rate and therefore G₀/G₁ phase arrest, as well as a statistically significant induction of apoptosis (P = 0.001), was only observed in the 5637 cell line.ConclusionRAD001 seems not to have a significant effect on chemically induced murine bladder tumors. The effect of RAD001 on tumor proliferation and apoptosis was achieved only in superficial derived bladder cancer cell line, no effect was observed in invasive cell lines.     

Synergistic cytotoxicity and apoptosis of JTE-522, a selective cyclooxygenase-2 inhibitor,and 5-fluorouracil against bladder cancer

PURPOSE: Cyclooxygenase-2 (COX-2) is a key inducible enzyme involved in the production of prostaglandins that has been shown to induce apoptosis in various cancer cells. Several anticancer agents also mediate apoptosis and may share the common intracellular pathways leading to apoptosis. Since over expression of COX-2 has been demonstrated in bladder cancer, we reasoned that combination treatment with a COX-2 inhibitor and anticancer agents in bladder cancer cells may result in synergistic apoptosis. We examined whether the selective COX-2 inhibitor JTE-522 induces apoptosis in bladder cancer cells and whether JTE-522 may act synergistically with anticancer agents to achieve cytotoxicity and apoptosis in these cells. MATERIALS AND METHODS: Cytotoxicity was determined by microculture tetrazolium dye assay. Synergy was assessed by isobolographic analysis. RESULTS: COX-2 mRNA expression was observed in the HT1197 bladder cancer cell line. JTE-522 was cytotoxic in HT1197 cells. Treating HT1197 cells with JTE-522 combined with doxorubicin or mitomycin C did not show synergistic cytotoxicity. However, combination treatment of HT1197 cells with JTE-522 and 5-fluorouracil (5-FU) resulted in a synergistic cytotoxic effect. Synergy was also achieved in the T24 bladder cancer line. Synergistic cytotoxicity was noted irrespective of treatment sequence but the highest percent cytotoxicity was obtained when HT1197 cells were treated with JTE-522 and 5-FU simultaneously. The synergy achieved in cytotoxicity with JTE-522 and 5-FU was shown to be due to apoptosis. The mechanisms responsible for synergistic cytotoxicity and apoptosis was examined. Treating HT1197 cells with 5-FU enhanced expression of the pro-apoptotic molecule Bax, while JTE-522 treatment reduced expression of the anti-apoptotic molecule Bcl-XL, resulting in a significantly higher ratio of Bax-to-Bcl-XL. CONCLUSIONS: This study shows that combination treatment of bladder cancer cells with the selective COX-2 inhibitor JTE-522 and 5-FU results in synergistic cytotoxicity and apoptosis due to the enhanced Bax-to-Bcl-XL expression ratio. These findings support the in vivo potential application of a combination of JTE-522 and 5-FU for bladder cancer.     

A comparison of the platinum analogues in bladder cancer cell lines

BACKGROUND: Oxaliplatin is a 3rd generation platinum analogue, which is active in a broad spectrum of tumours. Clinical trials using this drug in bladder cancer are underway, but not yet reported. There are currently no in vitro data regarding oxaliplatin in bladder cancer. Therefore, this study compares the efficacy of oxaliplatin with cisplatin and carboplatin, which are both used widely in this tumour type, in bladder cancer cell lines. METHOD: The efficacy of oxaliplatin, carboplatin and cisplatin were compared in 4 bladder cancer cell lines (5637, J82, HT1197 and 253J). Cell parameters including cell number, viability and apoptosis were assessed after 3 days of drug exposure. The effects of the drugs on the cell cycle were also observed. RESULTS: Overall cisplatin was the most potent at inducing cell death (IC(50) 11.5-70.6 microM). Oxaliplatin was the 2nd most potent drug (IC(50 )15.2-126.3 microM) and carboplatin the least effective (IC(50 )75.4-137.8 microM). Carboplatin was significantly less potent at inducing cell death than the other two drugs in all 4 cell lines. Carboplatin was also inferior at inducing apoptosis in 3 of the 4 cell lines. All three drugs had a similar effect on the cell cycle, causing an initial G2 block. CONCLUSIONS: These data suggest that oxaliplatin is a potent agent in bladder cancer cell lines and is superior to carboplatin in this in vitro setting. It justifies the clinical studies using oxaliplatin that are underway.     

Interferon-α inhibits cyclooxygenase-1 and stimulates cyclooxygenase-2 expression in bladder cancer cells in vitro

The enzymes cyclooxygenase-1 (Cox-1) and cyclooxygenase-2 (Cox-2) catalyze the initial step in the formation of prostaglandins (PGs). PGs are known to be involved in numerous processes, for example inflammation, immune responses, carcinogenesis, and tumor angiogenesis. The formation of PGs is stimulated in various cancers since the expression of Cox-2 is upregulated. Interferon (IFN)-α is used in the treatment of bladder cancer, although not all of the effects of such treatment are thoroughly known. Therefore, we investigated the expression of cyclooxygenases in two bladder cancer cell lines, 5637 and T24, under basal conditions and in the presence of human recombinant IFN-α (100, 1,000, and 10,000 U/ml). The mRNA of Cox-1 and Cox-2 was expressed in both cultured bladder carcinoma cell lines. The level of Cox-1 expression was low in 5637 cells and higher in T24 cells. In contrast, Cox-2 expression was prominent in 5637 cells and low in T24 cancer cells. The highest IFN-α concentration (10,000 U/ml) decreased the expression of Cox-1 to 47 and 28% of the control levels in 5637 and T24 cells, respectively. In contrast, Cox-2 expression increased in both cell lines. In 5,637 cells, Cox-2 expression increased 1.3-fold with 10,000 U/ml of IFN-α. In T24 cells, the maximum effect was achieved by 1,000 U/ml of IFN-α, which increased the expression of Cox-2 up to 2.4-fold. These findings may have relevance in the outcome of patients treated with IFN-α because upregulated Cox-2 expression may suppress the cell-mediated defense system. On the other hand, the inhibition of Cox-1 could be beneficial because Cox-1 is known to stimulate angiogenesis. Received: 5 August 1999 / Accepted: 8 September 2000     

Expression of Med19 in bladder cancer tissues and its role on bladder cancer cell growth

ObjectivesThe human Med19 gene encodes a critical subunit that stabilizes the whole mediator complex. To understand the role of Med19 in bladder cancer, we studied the effects of lentivirus-mediated suppression of Med19 expression on bladder cancer cells in vitro and in vivo.Methods and materialsIn this study, immunohistochemical analysis was used to demonstrate the expression of Med19 in human bladder cancer. The lentivirus vectors containing a small hairpin RNA (shRNA) to target Med19 were constructed. After bladder cancer cells (5637 and T24) were infected, RT-PCR and Western blotting were used to measure Med19 expression. The influence of Med19 on the proliferation of bladder cancer cells were assessed using MTT, BrdU, colony formation and tumorigenicity experiments. Cell cycle was analyzed with flow cytometric assay.ResultsMed19 was up-regulated in human bladder cancers compared with adjacent benign tissues by immunohistochemical analysis, but was strongly inhibited in 5637 and T24 bladder cancer cells infected with lentiviruses delivering shRNA against Med19. The down-regulation of Med19 increased the proportion of cells in G0/G1 phases and attenuated the growth of 5637 and T24 cells in vitro. The tumorigenicity of Med19-suppressed T24 cells was decreased after inoculation into nude mice.ConclusionsOur results suggested that lentiviruses delivering shRNA against Med19 may be a promising tool for bladder cancer therapy.     

E-cadherin和CAR在人膀胱癌细胞中的表达及其意义

目的检测上皮型钙黏素（E—cadherin）和柯萨奇-腺病毒受体（coxsackie and adenovirus receptor，CAR）在多种人膀胱癌细胞中的表达情况，初步讨论E-cadherin与CAR在人膀胱癌细胞中表达的意义及两者间的关联。方法用Western印迹法测定人膀胱癌细胞中E—cadherin和CAR的表达情况。结果E—cadherin，CAR在RT4、5637细胞中表达较高，在253J细胞中表达较低；E—cadherin在J82、T24细胞中不表达，CAR在J82细胞中微弱表达，在T24中不表达。结论E-cadherin和CAR在人膀胱癌细胞中的表达趋势一致，两者可能相互协作，共同参与膀胱癌的侵袭转移过程。     

LncRNA DANCR regulates lymphatic metastasis of bladder cancer via the miR-335/VEGF-C axis

BackgroundSubstantial evidence indicate that long non-coding RNA (lncRNA) and microRNA (miRNA) act as key role in bladder cancer. Differentiation antagonistic ncRNA (DANCR) could be used as a biomarker in the occurrence and development of cancer. This study aims to explore the mechanism of DANCR/miR-335/VEGF-C axis affecting lymphatic metastasis of bladder cancer.MethodsqRT-PCR detects the expression of DANCR in bladder cancer cell lines (SW780, 5637, T24, UM-UC-3) and normal bladder cell lines (SV-HUC-1), and selects T24 cell lines for subsequent experiments. The expression levels of DANCR, miR-335 and VEGF were measured by qRT-PCR, and the dual luciferase reporter gene verified the targeted regulation of DANCR on miR-335 and miR-335 on VEGF. CCK-8, Transwell and Wound healing assay detect the proliferation, invasion and migration ability of bladder cancer cells, Endothelial cell adhesion assay and Western blot further prove the lymphatic metastasis of bladder cancer.ResultsIn this study, DANCR was highly expressed in bladder cancer cell lines. Transfection of si-DANCR significantly inhibits the proliferation, migration, invasion and lymphatic metastasis of bladder cancer cells. Dual luciferase assay confirmed that DANCR targets miR-335/VEGF-C. Transfection of miR-335 mimic promotes the proliferation, migration, invasion and lymphatic metastasis of bladder cancer cells, overexpression of DANCR eliminates the promotion of miR-335 mimic on bladder cancer cells. Further experiments proved that inhibition of miR-335 and overexpression of VEGF-C can reverse the inhibitory effect of silencing DANCR on bladder cancer cells.ConclusionsIn bladder cancer, DARCR plays an important role, which regulates the proliferation, migration, invasion and lymphatic metastasis of bladder cancer cells through the miR-335/VEGF-C molecular axis.     

MiR-486-5p enhances cisplatin sensitivity of human muscle-invasive bladder cancer cells by induction of apoptosis and down-regulation of metastatic genes

ObjectivesCisplatin is one of the common chemotherapy drugs for bladder cancer, and resistance to this drug is one of the major obstacles to effective chemotherapy. MicroRNAs (miRNAs) are a category of small noncoding RNAs that can regulate the expression of numerous genes. Recent studies showed that miRNAs can act as a powerful regulator of chemo-sensitivity in cancer cells. Hence, this study aimed to investigate the effects of miRNA-486-5p on cisplatin-sensitivity of different bladder cancer cells.Material and MethodsThe 5637 and EJ138 cancer cells were treated with miRNA-486-5p and cisplatin, individually or in combination.ResultsAfterward, the cytotoxicity effects of these treatments were determined by MTT assay and the increased cisplatin-sensitivity observed in both cell lines, especially, 5637 cells. Moreover, subG1 phase cell cycle arrest, changes in the expression of caspase-9, caspase-3, P53, SIRT1, OLFM4, SMAD2, and Bcl-2 genes and nuclear fragmentation also revealed the induction of apoptosis in all treatments, which increased in combination groups. Also, the combination of miRNA-486-5p with cisplatin significantly down-regulated the expression of migration associated genes including ROCK, CD44, and MMP-9 as compared with cisplatin alone.ConclusionAltogether, these results indicated that the miRNA-486-5p could induce apoptosis and inhibit cell migration ability of the cells. It seems that pre-electroporation of cells with miRNA-486-5p has useful results in the enhancement of cisplatin sensitivity of 5637 and EJ138 cancer cells and this combination may be a promising treatment strategy for bladder cancer therapy.     

Multifactorial Involvement of Multidrug Resistance Protein, DNA Topoisomerase II and Glutathione/Glutathione-S-Transferase in NonP- Glycoprotein-Mediated Multidrug Resistance in Human Bladder Cancer Cells

Background :
Multiple mechanisms are important in multidrug resistance in urothelial cancers. We investigated the acquisition of a multidrug resistance phenotype in human bladder cancer cells exposed to doxorubicin.
Methods :
Human bladder cancer cell line 5637 and 2 doxorubicin drug-resistant sublines (5637/DR5.5 and 5637/DR50) were used. Measurements were made of the steady state mRNA levels of the multidrug resistance gene ( mdr 1), multidrug resistance-associated protein (MRP), glutathione-S-transferase-π and DNA topoisomerase II (topo II) genes, P-glycoprotein (PgP) and MRP expression, glutathione (CSH) and GSH enzyme activity, and topo II catalytic activity. The pharmacokinetics were compared between the parent and the drug-resistant sublines.
Results :
5637/DR5.5 and 5637/DR50 cells were 7.6- and 1 6.2-fold more resistant to doxorubicin and 16.7-and 48.3-fold more resistant to etoposide, respectively, compared with 5637 cells. A dose escalation of doxorubicin increased the MRP expression, CSH levels and glutathione-S-transferase (GST) activity, although no PgP expression was observed in any cell line. Resistance was brought about by decreased drug accumulation through drug efflux, although intracellular daunorubicin concentrations were similar between DR5.5 and DR50 cells. Topo II catalytic activity was undetectable in DR50 cells, but maintained in both the parent and DR5.5 cells.
Conclusion :
Reduced drug accumulation in doxorubicin-resistant cells was mediated by MRP instead of PgP indicating that MRP-mediated drug efflux functions in a limited manner for drug resistance. An increase in drug efflux via MRP, reduced topo II activity, and increased GSH levels/GSH-related enzyme activities may play major roles in nonPgP-mediated multidrug resistance in urothelial cancers treated with anthracyclines.     

Cytotoxicity of cisplatin in bladder cancer is significantly enhanced by application of bcl-2 antisense oligonucleotides

BACKGROUND: The aim of our study was to examine the effects of the combined application of cisplatin and bcl-2 antisense oligonucleotide on human bladder cancer cell lines to determine the possible synergistic effects in cytotoxicity and to estimate its potential value for subsequent in vivo trials. MATERIALS AND METHODS: Human bladder cancer cell lines (UM-UC 3, RT 112, T24/83 and HT 1197) were treated with bcl-2 antisense oligonucleotide, cisplatin, or a combination of both and incubated for 48 h under standard conditions. Cell survival was determined using a Neubauer haemocytometer or standard MTT assay. BCL-2 expression was verified using western blotting. RESULTS: The combined treatment resulted in significant lower cell survival rates compared to individual treatment. Additionally, there was a decrease in cell survival rate with an increase in cisplatin concentration in combined treatment that was not observed in cisplatin mono treatment. CONCLUSIONS: For the combined treatment with oligonucleotides and cisplatin a synergistic effect can be strongly suggested. Therefore, further investigations and in vivo trials have to be done to determine the possible benefits for clinical applications.     

Soluble Fas and Fas-ligand in bladder cancer in vitro and in vivo

Circulating soluble Fas (sFas) and expression of Fas-ligand on cancer cells are mechanisms of immune escape. The aim of the present study was to investigate expression and production of Fas and Fas-ligand on bladder cancer cell lines of different grade as a basic mechanism of their secretion in vivo. sFas and sFas-ligand serum levels of patients with different stage of bladder cancer were examined to determine the possible clinical use of these molecules as tumor markers. Bladder cancer cell lines RT4 (G1), RT112 (G1), T24 (G3) and SUP (G4) were analyzed by flowcytometry for Fas and Fas-ligand expression. To determine if the Fas-ligand gene is transcribed in these bladder cancer cell lines, RT-PCR was performed on mRNA extracted from these cell lines. Production of sFas and sFas-ligand was examined in cell culture supernatants of the cancer cells as well as in the serum of 62 patients with bladder cancer by a specific ELISA test. We demonstrate that Fas is expressed in similar levels on all human bladder carcinoma cell lines. In T24 (G3) and SUP (G4) cell lines we were able to detect the Fas-ligand protein, whereas no Fas-ligand protein could be found in RT4 and RT112 (G1) cells. Fas-ligand mRNA was expressed in all bladder cancer cell lines. Furthermore, all bladder cancer cell lines produce sFas but no sFas-ligand in spite of mRNA expression. The range of sFas levels in the serum of all patients with bladder cancer was large and did not show a correlation to the histopathological stage of bladder cancer. Although there is in vitro evidence that sFas and Fas-ligand play a role in bladder cancer, no correlation between the sFas and s Fas-ligand serum levels and the histopathological stage of bladder cancer could be found. Therefore, serum sFas and sFas-ligand have to date limited clinical relevance.     

LIN28在膀胱癌和膀胱癌细胞系中的表达及意义

目的：探讨LIN28在膀胱癌组织和细胞系中表达情况,以及与mieroRNA初级Let-7g（pri—Lev7g）之间关系,推测其可能临床意义及对肿瘤进展的影响。方法：采用常规RT-PCR、miRNA转录、免疫荧光和免疫组化方法,检测LIN28mRNA和pri-Let-7g表达,以及LIN28蛋白表达定位。结果：2例膀胱癌细胞系均表达LIN28mRNA,T24表达较强,免疫荧光显示这两个细胞系均表达LIN28蛋白,阳性部位位于细胞胞质,T24荧光强度强于5637。所选10例膀胱癌和相应癌旁组织均表达LIN28mRNA,二者并无明显不同,与临床分级也无明确关系。免疫组化显示癌组织LIN28表达阳性并定位于胞质,而癌旁正常组织LIN28表达为阴性。此外,两个细胞系pri—Let-7g表达较强,而癌和癌旁组织的pri—Let-7g表达强度无明显差异,需进一步检测其成熟Let-7g在这些组织中是否存在不同,以明确这些miRNA是否发生生物合成的转录后阻断。结论：明确T24和5637两个膀胱癌细胞系均可作为研究LIN28、Let-7与其相应靶基因关系的体外实验模型。尽管并不确定膀胱癌和癌旁组织LIN28、Let-7g表达强度与临床分级是否相关,但至少明确LIN28／LIN28在膀胱癌中表达,为探讨LIN28和Let-7在泌尿系统来源的其他恶性肿瘤中的作用提供借鉴和实验依据。