Human Bladder Tumor Cell Lines Research Articles

Abstract LB365: Generation of a novel severely immunodeficient Sprague Dawley rat model for xenograft studies

Abstract The recombinant-activating gene 2 (Rag2) plays a critical role in the recombination of the immunoglobulin and T cell receptor genes during the maturation of T and B cells. Loss of Rag2 protein leads to a lack of functional T and B cells, which eliminates the adaptive immune response. However, Rag2 deficiency alone may not guarantee the success of xenograft implantation, due to NK cells and other innate cells remaining. Il2rg is a key component of several cytokine receptors involved in differentiation and/or function of numerous adaptive and innate immune cells, including NK cells, mast cells, basophils, and dendritic cells. To generate a more severely immunodeficient rat model, both the Rag2 and Il2rg genes were knocked out in Sprague Dawley (SD) rats; this model was termed B-SDG rats. The immune profile and organ weights of thymus and spleen were investigated in B-SDG rats in comparison with Rag2-/- and wild-type SD rats. The spleen weights of both Rag2-/- and B-SDG rats were similar, but significantly reduced compared to wild-type SD rats. Notably, the thymus weights of B-SDG male rats were significantly smaller than those of Rag2-/- males. The immune cell profiles in thymus, spleen and blood were next evaluated by flow cytometry. A complete lack of B and T cells was observed in both Rag2-/- and B-SDG rats. B-SDG rats lacked CD161+ NK cells in the spleen and blood, which were maintained in Rag2-/- rats. Dendritic cells, monocytes, macrophages, and neutrophils were detected in all strains. In vivo xenograft implantation with human lung, bladder, breast, pancreas, acute monocytic and myelomonocytic leukemia tumor cell lines was next evaluated in B-SDG rats, which demonstrated successful engraftment. Furthermore, several efficacy studies were performed in B-SDG rats, including cisplatin chemotherapy on human breast invasive ductal carcinoma cell (HCC1954) and human large cell lung cancer cell (NCI-H460) xenografts, and a HER2-targeting ADC therapy was tested in B-SDG rats harboring human non-small cell lung cancer tumors (NCI-H1975). Taken together, these data confirm that B-SDG rats provide a powerful immunodeficient model for preclinical in vivo evaluation of novel drug candidates. Citation Format: Yanhui Nie, Meiqi Zhang, Wanling Zhong, Jia Feng, Bahetiyaer Huwatibieke, Zhaoxue Yu. Generation of a novel severely immunodeficient Sprague Dawley rat model for xenograft studies [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 2 (Late-Breaking, Clinical Trial, and Invited Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(7_Suppl):Abstract nr LB365.

Targeting urothelial neoplasia using an investigational virus-like drug conjugate.

514 Background: Human papillomavirus virus-like particles (HPV VLP) preferentially target tumor cells via cell surface modified heparan-sulfate proteoglycans (HSPG). The investigational virus-like drug conjugate, belzupacap sarotalocan (AU-011), is currently in phase 2 clinical trials for treatment of primary choroidal melanoma. We previously demonstrated AU-011’s in vivo tumor acute cytotoxicity upon activation with near-infrared light (nIR), resulting in tumor-free survival for at least 100 days and protection from tumor re-challenge in the MB49 murine flank model of bladder cancer. Here we provide additional data supporting further clinical development in urothelial neoplasia as an additional oncology indication. Methods: We examined the cytotoxicity of AU-011 in a panel of six human bladder cancer cell lines in vitro and binding and distribution in human tumor biopsy samples ex vivo. Tumor distribution of AU-011 was also assessed in vivo after intravesical instillation in the orthotopic MB49 murine model. In consideration of the glycocalyx layer often found coating the interior of the bladder wall and the surface of bladder tumors, pre-treatment with hyauronidase was tested both on human biopsy samples and in the murine orthotopic model. Lastly, tumor distribution of AU-011 was evaluated when formulated with the polyamide Syn3. Results: When tested in vitro on a panel of human bladder tumor cell lines representing grades I-IV carcinomas, we found AU-011’s potency to be in the picomolar range (EC50 range 16.6 pM – 62.75 pM). We assessed the VLPs ability to bind ex vivo to a panel of human urothelial tumor biopsies and observed binding in samples representing both invasive T2 and non-invasive Ta papillary tumors. Tumor biopsy samples were pre-treated with hyaluronidase to break down the glycocalyx layer surrounding the tumor, and an increase in signal was observed in the Ta biopsy sample. Similarly, using the orthotopic MB49 murine tumor model with intravesical delivery of AU-011, we observed an enhancement of AU-011 distribution into the tumor when the bladders were pre-treated with hyaluronidase. Additionally, when formulated with Syn3, AU-011 distribution throughout the tumors was augmented without the need for hyaluronidase pre-treatment. Conclusions: We have demonstrated AU-011 targeted cytotoxicity in vitro using a panel of human bladder cancer cell lines indicating that its binding to bladder cancer cells is tumor grade and genetic mutation agnostic. Additionally, tumor binding and distribution was observed ex vivo using human bladder cancer biopsy samples and in vivo in the murine MB49 orthotopic model. Human and murine tumor distribution was improved with a pre-treatment of hyaluronidase or when formulated with Syn3. Collectively, these data support the further investigation of the use of AU-011 for the indication of uroepithelial cancer.

Biomimetic TiO2-chitosan/sodium alginate blended nanocomposite scaffolds for tissue engineering applications.

The study is aimed to synthesize potent metal oxide based biomimetic nanocomposites to overcome the risk associated with artificial bone tissue engineering. High purity TiO2 nanoparticles are synthesized via hydrothermal route. A biomimetic nanocomposite scaffolds containing chitosan-sodium alginate (4: 4) blended with three different (0.5, 1, and 1.5wt%) concentrations of hydrothermally synthesized TiO2 nanoparticles are obtained by solvent casting technique. The physico-chemical and thermal degradation properties of as-synthesized TiO2 nanoparticles and their nanocomposite scaffolds are analyzed. In-vitro cytotoxicity and biocompatibility of the prepared TiO2 nanoparticles and nanocomposites are tested against human bladder tumor (UC6) and osteosarcoma (MG-63) cell lines. Antibacterial property is tested against Escherichia coli and Staphylococcus aureus. These studies reveal that TiO2 nanoparticles and polymeric nanocomposites contain good physico-chemical and mechanical properties for enhanced in-vitro biocompatibility suitable for biomedical applications. Biomimetically prepared chitosan-sodium alginate scaffold containing TiO2 nanoparticles (1wt%) is found to exhibit superior biocompatibility for bone tissue engineering applications.

Metabolism and growth inhibitory activity of cranberry derived flavonoids in bladder cancer cells.

In the present study, anti-proliferative activities of cranberry derived flavonoids and some of their in vivo metabolites were evaluated using a panel of human bladder tumor cell lines (RT4, SCABER, and SW-780) and non-tumorigenic immortalized human uroepithelial cells (SV-HUC). Among the compounds tested, quercetin 3-O-glucoside, isorhamnetin (3'-O-methylquercetin), myricetin and quercetin showed strong concentration-dependent cell growth inhibitory activities in bladder cancer cells with IC50 values in a range of 8-92 μM. Furthermore, isorhamnetin and myricetin had very low inhibitory activity against SV-HUC even at very high concentrations (>200 μM) compared to bladder cancer cells, indicating that their cytotoxicity is selective for cancer cells. To determine whether the differential cell growth inhibitory effects of isomeric flavonoids quercetin 3-O-glucoside (active) and hyperoside (quercetin 3-O-galactoside) (inactive) are related to their metabolism by the cancer cells, SW-780 cells were incubated with these compounds and their metabolism was examined by LC-MS/MS. Compared to quercetin 3-O-glucoside, hyperoside undergoes relatively less metabolic biotransformation (methylation, glucuronidation and quinone formation). These data suggest that isorhamnetin and quercetin 3-O-glucoside may be the active forms of quercetin in prevention of bladder cancer in vivo and emphasize the importance of metabolism for the prevention of bladder cancer by diets rich in cranberries.

Simultaneous Targeting of Bladder Tumor Growth, Survival, and Epithelial-to-Mesenchymal Transition with a Novel Therapeutic Combination of Acetazolamide (AZ) and Sulforaphane (SFN).

Current chemotherapies for advanced stage metastatic bladder cancer often result in severe side effects, and most patients become drug resistant over time. Thus, there is a need for more effective therapies with minimal side effects. The acid/base balance in tumor cells is essential for tumor cell functioning. We reasoned that simultaneous targeting of pH homeostasis and survival pathways would improve therapeutic efficacy. We evaluated the effectiveness of targeting pH homeostasis with the carbonic anhydrase inhibitor acetazolamide (AZ) in combination with the survival pathway targeting isothiocyanate sulforaphane (SFN) on the HTB-9 and RT112(H) human bladder tumor cell lines. We assessed viability, proliferation, and survival in vitro and effect on xenografts in vivo. Combination AZ + SFN treatment induced dose-dependent suppression of growth, produced a potent anti-proliferative and anti-clonogenic effect, and induced apoptosis through caspase-3 and PARP activation. The anti-proliferative effect was corroborated by significant reductions in Ki-67, pHH3, cyclin D1, and sustained induction of the cell cycle inhibitors, p21 and p27. Both active p-Akt (Ser473) and p-S6 were significantly downregulated in the AZ + SFN combination treated cells with a concomitant inhibition of Akt kinase activity. The inhibitory effects of the AZ + SFN combination treatment showed similar efficacy as the dual PI3K/mTOR pathway inhibitor NVP-BEZ235, albeit at an expected higher dose. In terms of the effect on the metastatic potential of these bladder cancers, we found downregulated expression of carbonic anhydrase 9 (CA9) concomitant with reductions in both E-cadherin, N-cadherin, and vimentin proteins mitigating the epithelial-to-mesenchymal transition (EMT), suggesting negation of this program. We suggest that reductions in these components could be linked with downregulation of the survival mediated Akt pathway and suggested an active role of the Akt pathway in bladder cancer. Altogether, our in vitro and pre-clinical model data support the potential use of an AZ + SFN combination for the treatment of bladder cancer.

Bladder Cancer: The Hormonal Dependence Enigma and a New Hormonal Player.

Dear Editor, Bladder cancer is considered to be a hormonal-independent malignancy. However, an increasing number of studies show that sex hormonesmight have an important role in the etiology or progression of specific urothelial carcinoma subtypes. The most important indication that bladder cancer might be influenced by sex hormone is that the incidence and risk of developing bladder cancer in men is notably greater comparing to women, even when established risk factors such as smoking, occupational exposure, and urinary tract infection are counterbalanced between the sexes. The effect of sex hormones in bladder tissues is documented during pregnancy and menopause where the bladder undergoes dramatic changes in structure, function, histology, and gene expression. Bladder tissues are shown to express androgen, estrogen, and progesterone receptors. Additionally, in animal models, estrogens are shown to inhibit and androgens to promote bladder cancer development even when carcinogenetic substances are used such as N-butyl-N-(4hydroylbutyl)nitrosamine [1]. Another indication of the hormonal contribution in bladder cancer development is the relatively lower risk of parous women to develop this malignancy compared to the nulliparous females. A human bladder tumor cell line, R198, was shown to develop under the effect of androgens while it regressed under the presence of estrogen [2]. Finally, there is also the report of a man who developed endometriosis of urinary bladder, after 5 years treatment with estrogen therapy for prostate cancer [3]. The lesion regressed after estrogen withdrawal, indicating a metaplasia potential of the urothelium under extreme changes of hormonal environment. Under these circumstances, we would like to report our experience of a 65-year-old woman treated for breast cancer who developed urothelial carcinoma at the trigone of the urinary bladder, 1 year after the onset of adjuvant hormonal therapy with third-generation non-steroidal aromatase inhibitor. The patient underwent modified radical mastectomy with ipsilateral axillary lymphadenectomy 4 years ago and subsequently chemotherapy (FEC and docetaxel) and radiotherapy. Three months after the onset of aromatase inhibitor treatment, the patient claimed to have aggravated hirsutism of both arms and no hair growth on the parietal skull following a pattern of androgenetic alopecia. A year since the onset of adjuvant hormonal therapy, a papillary protrusion was detected at the trigone of the urinary bladder. The histological report showed a non-muscle invasive low-grade papillary urothelial carcinoma, grade 1 by WHO-ISUP. One and a half year later, the patient was found to have bladder cancer relapse with the same histological urothelial tumor and the same androgenetic effects of the adjuvant hormonal therapy. The current hypothesis we propose is that the excessive androgen environment produced by the aromatase inhibitor in a postmenopausal woman with lack of the counterbalancing hormones (estrogen and progesterone) could contribute to the development of bladder cancer. There are some hypotheses which try to explain the hormonal dependence of bladder cancer and especially of the trigone of the urinary bladder. The trigone and the prostate have the same embryologic endodermic origin. This hypothesis is supported by the finding that the tumor cells of R198 cell line have some similar characteristics with human prostatic carcinomas [2]. Additionally, one of the ways that K. Ntzeros (*) :G. Louka Department of Urology, Hospital of Korinthos, Korinthos, Greece e-mail: konstantinos.ntzeros@gmail.com

CXCL5 knockdown expression inhibits human bladder cancer T24 cells proliferation and migration

CXCL5 (epithelial neutrophil activating peptide-78) which acts as a potent chemoattractant and activator of neutrophil function was reported to play a multifaceted role in tumorigenesis. To investigate the role of CXCL5 in bladder cancer progression, we examined the CXCL5 expression in bladder cancer tissues by real-time PCR and Western blot, additionally, we used shRNA-mediated silencing to generate stable CXCL5 silenced bladder cancer T24 cells and defined its biological functions. Our results demonstrated that mRNA and protein of CXCL5 is increased in human bladder tumor tissues and cell lines, down-regulation of CXCL5 in T24 cells resulted in significantly decreased cell proliferation, migration and increased cell apoptosis in vitro through Snail, PI3K-AKT and ERK1/2 signaling pathways. These data suggest that CXCL5 is critical for bladder tumor growth and progression, it may represent a potential application in cancer diagnosis and therapy.

Thiothymidine combined with UVA as a potential novel therapy for bladder cancer

Background:Thiothymidine (S4TdR) can be incorporated into DNA and sensitise cells to DNA damage and cell death following exposure to UVA light. Studies were performed to determine if the combination of S4TdR and UVA could be an effective treatment for bladder cancer.Methods:Uptake and incorporation of S4TdR was determined in rat and human bladder tumour cell lines. Measures of DNA crosslinking and apoptosis were also performed. In vivo activity of the combination of S4TdR and UVA was investigated in an orthotopic model of bladder cancer in rats.Results:Thiothymidine (200 μM) replaced up to 0.63% of thymidine in rat and tumour bladder cancer cells. The combination of S4TdR (10–200 μM) and UVA (1–5 kJ m−2) caused apoptosis and cell death at doses that were not toxic alone. Addition of raltitrexed (Astra Zeneca, Alderley Edge, Cheshire, UK) increased the incorporation of S4TdR into DNA (up to 20-fold at IC5) and further sensitised cells to UVA. Cytotoxic effect was associated with crosslinking of DNA, at least partially to protein. Intravenous administration of S4TdR, in combination with UVA delivered directly to the bladder, resulted in an antitumour effect in three of five animals treated.Conclusion:These data indicate that the combination of S4TdR and UVA has potential as a treatment for bladder cancer, and give some insight into the mechanism of action. Further work is necessary to optimise the delivery of the two components.

Cytotoxic T-lymphocytes response in vitro activated by dendritic cells pulsed with heat shock protein 70 derived from human bladder tumor cell lines of EJ

Objective To investigate whether human dendritic cells (DC) derived from peripheral blood mononuclear cells (PBMC), which were pulsed by heat shock protein 70 (HSP70) isolated from human bladder tumor cell lines of EJ, were able to induce peptide specific cytotoxic T-lymphocytes (CTL) response in vitro and give the experimental foundation for the future clinical trials of immunotherapy in bladder tumor.

Establishment of multidrug resistance cell line of human bladder tumor T24/ADM and the expression analysis of mechanism of multidrug resistance

Objective To establish a multidrug resistance cell line of human bladder tumor and study its characteristics and mechanism of muhidrug resistance. Methods Human bladder tumor cell line T24 was induced to muhidrug resistance cell line T24/ADM by intermittent administration of high dose ADM. The multidrug resistance to multianticancer agents of the ceils was evaluated by MTT assay; the expression of MDR gene was assessed by RT-PCR and P-gp expression was determined by flow cytometry. Results T24/ ADM resisted to many anti-tumor agents, and its IC50 of ADM was 16.3 times higher than that of T24. Significant overexpression of MDR gene and p-gp of the multidrug resistant cells were detected. Conclusion T24/ADM is a human muhidrug-resistant cell line, and it's drug resistance relates to the overexpression of MDR gene and p-gp. Key words: Urinary bladder neoplasms; Cell line, tumor, Muhidrug resistance-associated protein; Genes MDR

MP-600 Establishment and Characterization of a Novel Human bladder tumor cell line : Analysis of CD95 mediated apoptosis and survivin expression

MP-600 Establishment and Characterization of a Novel Human bladder tumor cell line : Analysis of CD95 mediated apoptosis and survivin expression

Crystal structures and cytotoxicity of isopropylamine Pt(II) complexes: A trinuclear squarato-bridged [Pt3(μ2-C4O4)3(H2NPri)6] · 3H2O and a mononuclear cis-[Pt(NO3)2(H2NPri)2

Crystals of a novel platinum(II) complex with squarato ligand, [Pt3(μ2-C4O4)3(H2NPri)6]·3H2O (1) (H2NPri=ipa), have been isolated from the aqueous solution of cis-[Pt(H2O)2(H2NPri)2]SO4 and barium squarate. Slow evaporation of methanol solution of cis-[Pt(NO3)2(H2NPri)2] (2) resulted in crystallization of nitrato complex.The single crystal X-ray diffraction method was used to determine structures of 1 and 2. Complex 1 crystallizes in a triclinic space group P1¯ with a=11.17380(10)Å, b=14.4535(2)Å, c=14.8010(2)Å, α=86.0901(10)°, β=78.4343(11)°, γ=69.1915(5)°, and complex 2 in a monoclinic space group P21/n, with a=10.1161(2)Å, b=9.9188(2)Å, c=13.3766(2)Å, β=102.7360(7)°. The X-ray structure analysis revealed that three platinum atoms in 1 are connected with three squarates which adopt bis(unidentate) binding modes. The squarato ligands span relatively long intramolecular Pt⋯Pt distances (4.8842(3)–5.2699(3)Å). A pair of cis positioned isopropylamine ligands completes a square planar coordination sphere of each Pt(II) ion. The square–planar coordination of complex 2 consists of two cis positioned isopropylamine ligands and two nitrato ligands.The results of cytotoxicity assay of trimer 1, monomer 2 and cis-diamminedichloroplatinum(II) (cisplatin) performed on human bladder tumor cell line T24 provide evidence that complex 2 is less cytotoxic compared to cisplatin and that the survival of tumor cells after exposure to 1 was minimally reduced.

Gefitinib ('Iressa', ZD1839) inhibits the growth response of bladder tumour cell lines to epidermal growth factor and induces TIMP2.

The effect of EGF stimulation and its inhibition with gefitinib (‘Iressa’, ZD1839), an epidermal growth factor receptor (EGFR) tyrosine kinase inhibitor, has been investigated in two EGFR-positive human bladder tumour cell lines, RT112 and RT4. The growth of RT112 cells in a medium containing 10% foetal bovine serum was inhibited by 50% with 10 μM gefitinib, whereas this dose completely inhibited RT4 cell growth. Cells were more sensitive to growth inhibition in the serum-free medium. Increased growth of cells in the serum-free medium was observed with 10 or 50 ng ml−1 EGF and the proliferative effect of EGF stimulation in both cell lines was inhibited in the presence of 1 μM, but not 0.1 μM gefitinib. Zymography of the conditioned medium from RT112 cells treated with EGF and gefitinib showed a decrease in matrix metalloproteinase 2 (MMP2) concentrations. Western blot analysis showed that tissue inhibitor of metalloproteinase 1(TIMP1) increased in the conditioned medium from RT112 cells treated with EGF, and this was partially inhibited with both 1 and 5 μM gefitinib. Conversely, TIMP2 decreased with EGF stimulation and this was reversed with gefitinib. Tissue inhibitor of metalloproteinase 1 had no effect on the growth of either cell line. These studies show alterations in the balance of MMPs and their inhibitors in EGF-stimulated bladder tumour cells, which are reversed by gefitinib, suggesting gefitinib should be investigated for its effect on human bladder tumours.

Inhibition of orthotopic human bladder tumor growth by lentiviral gene transfer of endostatin.

Inhibitors of endothelial cell proliferation, such as endostatin, result in suppression of tumor-associated angiogenesis and can achieve growth-inhibitory effects depending on the type of tumor treated. The purpose of this study was to investigate whether local overexpression of endostatin could serve to diminish tumor growth of bladder cancer in vivo. We examined the capability of lentiviral-mediated gene transfer in vitro and therapeutic effects of lentivirus-based vectors expressing endostatin on tumor growth using an orthotopic human bladder tumor model. We found that self-inactivating lentivirus vectors containing green fluorescent protein, alone or in combination with endostatin, were capable of efficient and stable gene transfer to a variety of human bladder tumor cell lines. The production and secretion of endostatin from lentivirus-transduced KU-7 human bladder cancer cells was confirmed by Western blot and competitive enzyme immunoassay. Intravesical instillation of untransduced, green fluorescent protein control lentivirus-transduced, and endostatin-transduced KU-7 cells was performed in murine models to establish orthotopic tumors. Sustained long-term expression of endostatin was achieved in lentivirus-transduced orthotopic bladder tumors, and it was associated with decreased vascularization and inhibition of tumor growth. Lentivirus vector-mediated overexpression of endostatin did not affect the intrinsic production of basic fibroblast growth factor and vascular endothelial growth factor. These findings suggest that lentivirus-mediated gene transfer might represent an effective strategy for expression of angioinhibitory peptides to achieve inhibition of human bladder cancer proliferation and tumor progression.

Androgen Dependent Regulation of bacillus Calmette-Guerin Induced Interleukin-6 Expression in Human Transitional Carcinoma Cell Lines

Autocrine expression of interleukin (IL)-6 by transitional cell carcinoma (TCC) in response to bacillus Calmette-Guerin (BCG) may have an important role in promoting BCG adherence to TCC and consequently in BCG treatment efficacy. IL-6 expression in response to BCG requires nuclear factor (NF)-kappaB mediated signal transduction. We evaluated the influence of androgens on BCG induced, NF-kappaB mediated IL-6 expression. Reverse transcriptase-polymerase chain reaction was used to confirm androgen receptor expression in the human TCC lines 253J and T24. A reporter construct containing an androgen response element was used to establish the integrity of androgen mediated signal transduction. Subsequently the dose dependent effect of dihydrotestosterone (DHT) on BCG induced IL-6 expression and NF-kappaB signaling was evaluated. Two pharmacological androgen receptor blockers were used to determine if receptor blockade inhibited the effect of DHT on activation of the androgen response element, NF-kappaB signaling and BCG induced IL-6 expression. The 2 human TCC lines expressed androgen receptor and demonstrated intact androgen stimulated signaling pathways. DHT suppressed BCG induced, NF-kappaB mediated signaling and IL-6 expression in a dose dependent manner. DHT decreased mRNA levels of IL-6, expression of the full-length IL-6 promoter construct and expression of an NF-kappaB specific reporter construct in response to BCG relative to controls. Competitive pharmacological blockade of androgen receptor inhibited the effect of DHT on BCG induced signaling in dose dependent fashion. DHT down-regulates NF-kappaB mediated IL-6 expression by human TCC lines in response to BCG. This effect depends on a functional androgen receptor signaling pathway and it can be blocked by the inhibition of androgen/androgen receptor binding.

Interleukin-6 Production by Human Bladder Tumor Cell Lines is Up-Regulated by Bacillus Calmette-Guerin Through Nuclear Factor-κB and Ap-1 Via an Immediate Early Pathway

The expression of interleukin-6 (IL-6) by normal and malignant urothelium in response to bacillus Calmette-Guerin (BCG) may have direct and indirect effects on the antitumor activity of BCG. We evaluated the molecular signaling pathway through which BCG induces IL-6 expression in human transitional cell carcinoma lines. We evaluated IL-6 messenger RNA and protein expression by human transitional carcinoma cell lines in response to BCG. Pharmacological inhibition of protein synthesis was used to determine if BCG mediated IL-6 induction occurred via an immediate-early or delayed pathway. We used 5' deletion analysis and site directed mutagenesis to identify BCG responsive regions in the human IL-6 promoter. Electrophoretic mobility shift assays were done to assess nuclear translocation of the putative signaling proteins AP-1 and nuclear factor-kappaB (NF-kappaB) in response to BCG. BCG increased IL-6 messenger RNA and protein in a time and dose dependent manner. IL-6 induction by BCG occurred via an immediate-early response. Promoter analysis identified 2 areas in the -1,200 to 14, 5' region of the IL-6 gene, which when deleted were associated with significant losses of absolute or BCG responsive activity. Site specific mutation of putative AP-1 or NF-kappaB elements associated with each region demonstrated that these elements were necessary but not sufficient for BCG induced IL-6 transcription. Gel mobility shift assays showed that AP-1 and NF-kappaB were induced in response to BCG exposure. Our results show that BCG induced IL-6 expression by human transitional cell neoplasms occurs as an immediate-early gene pathway that requires NF-kappaB and AP-1.

Interleukin-6 Production by Human Bladder Tumor Cell Lines is Up-Regulated by Bacillus Calmette-Guerin Through Nuclear Factor-??B and Ap-1 Via an Immediate Early Pathway

Interleukin-6 Production by Human Bladder Tumor Cell Lines is Up-Regulated by Bacillus Calmette-Guerin Through Nuclear Factor-??B and Ap-1 Via an Immediate Early Pathway

Cell Adhesion Proteins As Tumor Suppressors

We summarize recent progress on the role of cell adhesion molecules in biology and discuss the potential application of cell adhesion molecules for managing urological cancer. We comprehensively reviewed the literature from 1982 to 2001, including peer reviewed publications and recent abstracts from national meetings, relevant to cell adhesion molecules in urological cancer. A growing body of evidence suggests that alterations in the adhesion properties of neoplastic cells have a pivotal role in the development and progression of cancer. Loss of intercellular adhesion and desquamation of cells from the underlying lamina propria allows malignant cells to escape from their site of origin, degrade the extracellular matrix, acquire a more motile and invasion phenotype, and invade and metastasize. In addition to participating in tumor invasiveness and metastasis, adhesion molecules regulate or significantly contribute to various functions, including signal transduction, cell growth, differentiation, site specific gene expression, morphogenesis, immunological function, cell motility, wound healing and inflammation. To date a diverse system of transmembrane glycoproteins has been identified that mediates cell-cell and cell-extracellular matrix adhesion. The main families of adhesion molecules include members of the Ig superfamily, cadherins, integrins and selectins. Multiple and diverse cell adhesion molecules participate in intercellular and cell-extracellular matrix interactions of cancer. Cancer progression is a multistep process, in which some adhesion molecules have a pivotal role in the development of recurrent, invasive and distant metastasis. Recent data implicate some of these molecules in cell signaling and tumor suppression, which has important consequences for tumor growth.

Ellagica acid inhibits arylamine N-acetyltransferase activity and DNA adduct formation in human bladder tumor cell lines (T24 and TSGH 8301)

The fact that vitamin C (ascorbic acid) exhibits a protective effect in certain types of cancer is well documented. Our previous studies demonstrated that human bladder tumor cell line (T24) has N-acetyltransferase (NAT) activity in cytosols and intact cells. The present studies examined the inhibition of arylamine NAT activity and carcinogen (2-aminofluorene)-DNA adduct formation by ellagic acid (EA) in human bladder tumor cell lines (T24 and TSGH 8301). Two assay systems were performed, one with cellular cytosols (9,000g supernatant), the other with intact bladder tumor cell suspensions. NAT activity and 2-aminofluorene-DNA adduct formation in T24 and TSGH 8301 cells was inhibited by EA in a dose-dependent manner in both systems, i.e., the greater the concentration of EA in the reaction the greater the inhibition of NAT activity (dose-and time-course dependent effects). The data also indicated that EA decreased the apparent Km and Vmax of NAT enzymes from T24 and TSGH 8301 cells in cytosols. NAT activity and 2-aminofluorene-DNA adducts in T24 is higher than in TSGH 8301. This report is the first to demonstrate that EA affects human bladder tumor cell NAT activity.

Sulindac inhibited gene expression and activity of arylamine N-acetyltransferase and DNA-2-aminofluorene adduct formation in T24 human bladder tumor cells.

We demonstrated in vivo that non-steroidal anti-inflammatory drugs including sulindac can act as inhibitors of urinary bladder carcinogenesis in rats. The aim of the present study was to determine whether sulindac affects arylamine N-acetyltransferase (NAT) activity and gene expression and DNA-2-aminofluorene adduct formation in the T24 human bladder tumor cell line. The NAT activity (N-acetylation of 2-aminofluorene) was measured by high performance liquid chromatography assaying for the amount of acetylated 2-aminofluorene and the remaining 2-aminofluorene (AF). The results demonstrated that NAT activity in T24 cells were inhibited by the sulindac in a dose-dependent manner. The apparent values of Km and Vmax of NAT from T24 cells were also decreased by sulindac. This inhibition was not competitive. The amount of DNA-AF adduct formation in T24 cells was also inhibited by sulindac. The data also demonstrated that sulindac inhibited the NAT mRNA level in T24 cells.