Morphological characterization of two established cell lines, T24 and MGH-U1, derived from human urinary bladder carcinoma

Differences of the tumour cell glycocalyx affect binding of capsaicin-loaded chitosan nanocapsules

The glycocalyx regulates the interaction of mammalian cells with extracellular molecules, such as cytokines. However, it is unknown to which extend the glycocalyx of distinct cancer cells control the binding and uptake of nanoparticles. In the present study, exome sequencing data of cancer patients and analysis of distinct melanoma and bladder cancer cell lines suggested differences in cancer cell-exposed glycocalyx components such as heparan sulphate. Our data indicate that glycocalyx differences affected the binding of cationic chitosan nanocapsules (Chi-NCs). The pronounced glycocalyx of bladder cancer cells enhanced the internalisation of nanoencapsulated capsaicin. Consequently, capsaicin induced apoptosis in the cancer cells, but not in the less glycosylated benign urothelial cells. Moreover, we measured counterion condensation on highly negatively charged heparan sulphate chains. Counterion condensation triggered a cooperative binding of Chi-NCs, characterised by a weak binding rate at low Chi-NC doses and a strongly increased binding rate at high Chi-NC concentrations. Our results indicate that the glycocalyx of tumour cells controls the binding and biological activity of nanoparticles. This has to be considered for the design of tumour cell directed nanocarriers to improve the delivery of cytotoxic drugs. Differential nanoparticle binding may also be useful to discriminate tumour cells from healthy cells.

TRIM65 supports bladder urothelial carcinoma cell aggressiveness by promoting ANXA2 ubiquitination and degradation

Clinically, most of human urothelial carcinoma of the bladder (UCB)-related deaths result from tumor metastasis, but the underlying molecular mechanisms are largely unknown. Recently, a growing number of tripartite motif (TRIM) family members have been suggested to be important regulators for tumorigenesis. However, the impact of most TRIM members on UCB pathogenesis is unclear. In this study, TRIM65 was first screened as an important oncogenic factor of UCB from the Cancer Genome Atlas (TCGA) database and was validated by a large cohort of clinical UCB tissues. By in vitro and in vivo experiments, we demonstrated that TRIM65 promotes UCB cell invasive and metastatic capacities. Notably, we showed that TRIM65 modulates cytoskeleton rearrangement and induces UCB cells epithelial-mesenchymal transition by the ubiquitination of ANXA2, ultimately leading to an enhanced invasiveness of UCB cells. Importantly, UCBs with high expression of TRIM65 and low expression of ANXA2 showed the poorest outcome. Collectively, our results suggest that the overexpression of TRIM65 has an essential oncogenic role via ubiquitination of ANXA2 in UCB pathogenesis, and that such could be used as a novel prognostic marker and/or therapeutic target for UCB.

Treating urinary tract infections due to MDR E. coli with Isothiocyanates - a phytotherapeutic alternative to antibiotics?

BACKGROUND

Multidrug-resistant (MDR) bacteria are increasingly causing urinary tract infections (UTI), which has been linked to frequent use of antibiotics. Alternative treatment regimens are urgently needed and natural isothiocyanates (ITC) may represent one. ITCs are natural plant products found in nasturtium (Tropaeoli majoris herba) and horseradish (Armoraciae rusticanae radix).

PURPOSE

The objectives were to (1) assess the antimicrobial effects of nature-identical ITCs for UTI treatment caused by uropathogenic E. coli (UPEC), (2) to evaluate a potential influence of antimicrobial resistance on ITC susceptibility, and (3) to test whether ITCs affect UPEC penetration into human uroepithelial cells.

METHODS

We tested 217 clinical UPEC isolates, 54.5% of which were classified as MDR, for susceptibility against ITCs. ITC susceptibility testing was performed by broth dilution using a mixture of three synthetic ITCs. Internalization was tested using human T-24 bladder carcinoma cells in an internalization assay co-incubated with UPEC (n = 5) and ITCs.

RESULTS

The mean minimal inhibitory concentration (MIC) 90 was 0.17 mg/ml, showing very high susceptibility against ITCs. Interestingly, MDR E. coli were significantly less susceptible than non-MDR strains (p = .01). Internalization of UPEC was decreased by 31.9% in the mean when treated with ITCs. Overall, ITCs exerted a strong antimicrobial activity against clinical UPEC isolates and reduced internalization into uroepithelial cells.

CONCLUSION

ITCs might present a promising treatment alternative for UTIs, expressing both high antimicrobial activity as well as blocking the pathogenic process of human cell penetration by UPEC. Clinical studies, however, are needed to confirm activity of ITCs in UTIs in vivo.

Cross-contamination of a UROtsa stock with T24 cells--molecular comparison of different cell lines and stocks

BACKGROUND

UROtsa is an authentic, immortalized human urothelial cell line that is used to study the effects of metals and other toxic substances, mostly in the context of bladder cancer carcinogenesis. Unusual properties on the molecular level of a provided UROtsa cell line stock prompted us to verify its identity.

METHODS

UROtsa cell line stocks from different sources were tested on several molecular levels and compared with other cell lines. MicroRNA and mRNA expression was determined by Real-Time PCR. Chromosome numbers were checked and PCR of different regions of the large T-antigen was performed. DNA methylation of RARB, PGR, RASSF1, CDH1, FHIT, ESR1, C1QTNF6, PTGS2, SOCS3, MGMT, and LINE1 was analyzed by pyrosequencing and compared with results from the cell lines RT4, T24, HeLa, BEAS-2B, and HepG2. Finally, short tandem repeat (STR) profiling was applied.

RESULTS

All tested UROtsa cell line stocks lacked large T-antigen. STR analysis unequivocally identified our main UROtsa stock as the bladder cancer cell line T24, which was different from two authentic UROtsa stocks that served as controls. Analysis of DNA methylation patterns and RNA expression confirmed their differences. Methylation pattern and mRNA expression of the contaminating T24 cell line showed moderate changes even after long-term culture of up to 56 weeks, whereas miRNAs and chromosome numbers varied markedly.

CONCLUSIONS

It is important to check the identity of cell lines, especially those that are not distributed by major cell banks. However, for some cell lines STR profiles are not available. Therefore, new cell lines should either be submitted to cell banks or at least their STR profile determined and published as part of their initial characterization. Our results should help to improve the identification of UROtsa and other cells on different molecular levels and provide information on the use of urothelial cells for long-term experiments.

Intracellular delivery of full length recombinant human mitochondrial L-Sco2 protein into the mitochondria of permanent cell lines and SCO2 deficient patient's primary cells

Mutations in human SCO2 gene, encoding the mitochondrial inner membrane Sco2 protein, have been found to be responsible for fatal infantile cardioencephalomyopathy and cytochrome c oxidase (COX) deficiency. One potentially fruitful therapeutic approach for this mitochondrial disorder should be considered the production of human recombinant full length L-Sco2 protein and its deliberate transduction into the mitochondria. Recombinant L-Sco2 protein, fused with TAT, a Protein Transduction Domain (PTD), was produced in bacteria and purified from inclusion bodies (IBs). Following solubilisation with l-arginine, this fusion L-Sco2 protein was transduced in cultured mammalian cells of different origin (U-87 MG, T24, K-562, and patient's primary fibroblasts) and assessed for stability, transduction into mitochondria, processing and impact on recovery of COX activity. Our results indicate that: a) l-Arg solution was effective in solubilising recombinant fusion L-Sco2 protein, derived from IBs; b) fusion L-Sco2 protein was delivered successfully via a time- and concentration-dependent process into the mitochondria of human U-87 MG and T24 cells; c) fusion L-Sco2 protein was also transduced in human K-562 cells, transiently depleted of SCO2 transcripts and thus COX deficient; transduction of this fusion protein led to partial recovery of COX activity in such cells; d) [(35)S]Methionine-labelled fusion L-Sco2 protein, produced in a cell free transcription/translation system and incubated with intact isolated mitochondria derived from K-562 cells, was efficiently processed to yield the corresponding mature Sco2 protein, thus justifying the potential of the transduced fusion L-Sco2 protein to successfully activate COX holoenzyme; and finally, e) recombinant fusion L-Sco2 protein was successfully transduced into the mitochondria of primary fibroblasts derived from SCO2/COX deficient patient and facilitated recovery of COX activity. These findings provide the rationale of delivering recombinant proteins via PTD technology as a model for therapeutic approach of mitochondrial disorders.

Radiation-induced HPRT mutations resulting from misrejoined DNA double-strand breaks

DNA double-strand breaks (DSBs) are the most severe lesions induced by ionizing radiation, and unrejoined or misrejoined DSBs can lead to cell lethality, mutations and the initiation of tumorigenesis. We have investigated X-ray- and alpha-particle-induced mutations that inactivate the hypoxanthine guanine phosphoribosyltransferase (HPRT) gene in human bladder carcinoma cells and in hTERT-immortalized human fibroblasts. Fifty to 80% of the mutants analyzed exhibited partial or total deletions of the 9 exons of the HPRT locus. The remaining mutants retained unaltered PCR products of all 9 exons but often displayed a failure to amplify the HPRT cDNA. Hybridization analysis of a 2-Mbp NotI fragment spanning the HPRT gene with a probe 200 kbp distal to the HPRT locus indicated altered fragment sizes in most of the mutants with a wild-type PCR pattern. These mutants likely contain breakpoints for genomic rearrangements in the intronic sequences of the HPRT gene that allow the amplification of the exons but prevent HPRT cDNA amplification. Additionally, mutants exhibiting partial and total deletions of the HPRT exons also frequently displayed altered NotI fragments. Interestingly, all mutations were very rarely associated with interchromosomal exchanges analyzed by FISH. Collectively, our data suggest that intrachromosomal genomic rearrangements on the Mbp scale represent the prevailing type of radiation-induced HPRT mutations.

Searching cell-secreted proteomes for potential urinary bladder tumor markers

To search for biomarkers critical for bladder carcinoma diagnosis and prognosis, secreted proteomes of highly malignant U1 and pre-malignant U4 cell lines were initially analyzed. Proteins in the culture media of the U1 and U4 cell lines were systematically examined by SDS-PAGE combined with MALDI-TOF MS. Among them, expression of pro-u-plasminogen activator (pro-u-PA) was confirmed by Western blot analysis and further evaluated. In analyzing urine samples from bladder cancer patients and normal subjects, we established a statistically significant relationship between the low level and absence of pro-u-PA in urine with high stages and grades of the tumor samples. Constitutive expression of Ras dominant negative protein led to increased expression of pro-u-PA in culture media, indicating that the loss of pro-u-PA is associated with oncogenic transformation. Analysis of cancer-secreted proteomes can be a feasible, non-invasive and efficient strategy for searching potential bladder tumor biomarkers. Our work also has identified the loss of pro-u-PA in urine as potential marker of more advanced bladder carcinoma.

Ras-dependent recruitment of c-Myc for transcriptional activation of nucleophosmin/B23 in highly malignant U1 bladder cancer cells

U1 bladder cancer cells of high malignancy exhibited higher proliferation capacity than U4 premalignant cells. Higher expression of Ras, c-Myc, and nucleophosmin/B23 and greater c-Myc transactivation and nucleophosmin/B23 promoter activities were detected in U1 cells compared with U4 cells. Moreover, c-Myc and nucleophosmin/B23 were increased in U1 but not in U4 cells upon serum stimulation from quiescence. Likewise, only in U1 cells could serum stimulate transcriptional activity of nucleophosmin/B23 promoter and c-Myc response element. The increase of nucleophosmin/B23 promoter activity could be abrogated by mitogen-activated protein kinase/extracellular signal-regulated kinase activating kinase inhibitor and was associated with recruitment of c-Myc to the promoter. U1 cells constitutively expressing dominant-negative Ras reduced the levels of Ras, nucleophosmin/B23, and p-ERK, and consequently abolished the serum-induced up-regulation of nucleophosmin/B23 promoter activity and c-Myc promoter recruitment. Our results indicate that Ras and c-Myc play important roles in the up-regulation of nucleophosmin/B23 during proliferation of cells associated with a high degree of malignancy, thus outlining a signaling cascade involving these factors in the cancer cells.

Nucleophosmin/B23 regulates transcriptional activation of E2F1 via modulating the promoter binding of NF-kappaB, E2F1 and pRB

Expression of nucleophosmin/B23 and E2F1 and E2F1-dependent transcription increased in U1 bladder cancer cells upon serum stimulation from quiescence. Nucleophosmin/B23-siRNA treatment abrogated such increase of E2F1-dependent transcriptional activity. In identifying physiologically important factors that may occupy E2F1 promoter and regulate its activity in vivo, we found that the pattern of NF-kappaB, E2F1 and pRB recruitment to E2F1 promoter changed in a strikingly dynamic fashion as cells progressed from quiescence into serum-stimulated growth. E2F1 promoter activity in quiescent cells was associated with recruitment of NF-kappaB. NF-kappaB was replaced largely by E2F1 in concert with gene activation during the early stage (12 h) of serum stimulation. At late stage (24 h) of serum stimulation, pRB was then recruited to the E2F1-promoter complex to counterbalance its activity. Upon siRNA-mediated reduction of intracellular nucleophosmin/B23, E2F1 and pRB were recruited to the promoter with the dissociation of NF-kappaB concomitant with gene inactivation. Based on immunoprecipitation experiments, nucleophosmin/B23 was found to be associated with NF-kappaB in cells grown in serum-supplemented but not in serum-deprived medium. Furthermore, nucleophosmin/B23 could also be co-immunoprecipitated with ppRB at the early stage (12 h) but not at the late stage (24 h) of serum stimulation. The results demonstrate a novel mechanism for transcriptional regulation of E2F1 and identify the functional role of nucleophosmin/B23 in modulating the binding of NF-kappaB, E2F1 and pRB to activate E2F1 promoter.

Nucleophosmin/B23-binding peptide inhibits tumor growth and up-regulates transcriptional activity of p53

The Rev peptide that binds to nucleophosmin/B23 with the highest affinity exhibited the greatest cytotoxicity on Ras-3T3 cells and inhibited tumor growth most effectively in nude mice. The efficiency of colony formation in soft agar of Ras-3T3 cells was significantly inhibited by treatment with Rev peptide. In addition, Rev peptide could potentiate the doxorubicin-induced decrease of cellular viability in U1 bladder cancer cells and inhibition of tumor growth in nude mice. Treatment of Rev peptide increased protein expression and transcriptional activity of p53 and inhibited the nucleophosmin/B23-mediated PCNA promoter activation. Peptides having high affinity of binding to molecular targets such as nucleophosmin/B23 represent a potentially useful approach to anti-cancer biotherapeutics.

Morphology and DNA degeneration during autoschizic cell death in bladder carcinoma T24 cells induced by ascorbate and menadione treatment

Feulgen and actin-phalloidin staining as well as gel electrophoresis have been employed in conjunction with cell ultrastructure to describe the effects of 1-, 2-, and 4-hr ascorbate (VC), menadione (VK(3)), and ascorbate:menadione (VC:VK(3)) treatments on the T24 human bladder carcinoma cell line. T24 cells exposed to VC alone display blebs and other superficial membrane defects related to membrane alterations and to superficial cytoskeleton changes. VK(3) treatment damages the cell nucleus and organelles, leads to the redistribution of the organelles in the perikaryon as a consequence of cytoskeletal damage, and results in cytoplasmic self-excisions. After VC:VK(3) treatment, the cells show exaggerated alterations characteristic of each vitamin treatment alone, including damaged mitochondria, self-excision of organelle-free pieces of cytoplasm, and extrusion of the perikaryon containing a nucleus surrounded by the damaged organelles. The nuclear envelope appears intact and contains chromatin that decondenses and dissipates. During the cellular demise that concludes with apparent karyolysis, the cells significantly decrease their size and alter their shape. However, the cisterns of rough endoplasmic reticulum are undamaged, but may become dilated. Since the cellular phenomena leading to cell death differ morphologically from apoptosis and necrosis, but entail self-cutting without nuclear bodies, this new form of cell death was called autoschizis. In addition, gel electrophoresis and Feulgen staining demonstrate that autoschizis is accompanied by random DNA degeneration.

Upregulation of retinoic acid-inducible gene-I in T24 urinary bladder carcinoma cells stimulated with interferon-gamma

Urinary bladder epithelial cells play an important role in the host defense against urinary tract infections. Interferon-gamma (IFN-gamma) is a potent cytokine that regulates immune responses by inducing multiple genes in many types of cells including urinary bladder epithelial cells. Retinoic acid-inducible gene-I (RIG-I) is a member of the DExH-box family, which is involved in various reactions related to RNA metabolism, and is induced in leukemic cells by retinoic acid or in endothelial cells by lipopolysaccharide. We have studied the expression of RIG-I in T24 cells, a cell line derived from human urinary bladder epithelial carcinoma cells. IFN-gamma stimulated T24 cells to express RIG-I mRNA and protein in concentration- and time-dependent manners. Immunohistochemical analysis revealed the expression of RIG-I in the urinary bladder epithelium from a patient with chronic urinary tract infection and in a bladder epithelial carcinoma. We conclude that RIG-I may play some role in inflammatory reactions in the urinary tract epithelium.

Primary uroepithelial cultures. A model system to analyze umbrella cell barrier function

Despite almost 25 years of effort, the development of a highly differentiated and functionally equivalent cell culture model of uroepithelial cells has eluded investigators. We have developed a primary cell culture model of rabbit uroepithelium that consists of an underlying cell layer that interacts with a collagen substratum, an intermediate cell layer, and an upper cell layer of large (25-100 micrometer) superficial cells. When examined at the ultrastructural level, the superficial cells formed junctional complexes and had an asymmetric unit membrane, a hallmark of terminal differentiation in bladder umbrella cells. These cultured "umbrella" cells expressed uroplakins and a 27-kDa uroepithelial specific antigen that assembled into detergent-resistant asymmetric unit membrane particles. The cultures had low diffusive permeabilities for water (2.8 x 10(-4) cm/s) and urea (3.0 x 10(-7) cm/s) and high transepithelial resistance (>8000 Omega cm2) was achieved when 1 mM CaCl2 was included in the culture medium. The cell cultures expressed an amiloride-sensitive sodium transport pathway and increases in apical membrane capacitance were observed when the cultures were osmotically stretched. The described primary rabbit cell culture model mimics many of the characteristics of uroepithelium found in vivo and should serve as a useful tool to explore normal uroepithelial function as well as dysfunction as a result of disease.

Establishment and characterization of a new cell line from human bladder cancer (JMSU1)

A new human bladder cancer cell line designated JMSU1 has been established from malignant ascitic fluid of a 75-year-old Japanese man with bladder cancer, and maintained in culture for more than 7 years and over 240 passages. Inverted phase-contrast microscopy revealed that JMSU1 was composed of morphologically distinct cells (polygonal to spindle-shaped cells), showing morphological heterogeneity in vitro. Histological examination of xenografts showed poorly differentiated transitional cell carcinoma, resembling the original tumor. Immunohistochemical staining for cytokeratin and electron microscopic examination suggested that JMSU1 was of epithelial origin. Chromosome analysis gave a modal number of 69 with no Y chromosome. Isozyme analysis (LDH, G6PD, and NP) showed the mobility pattern of human type B. DNA fingerprint analysis demonstrated that there was no cross-culture contamination of JMSU1 during the passages. In conclusion, a newly established and well-characterized cell line, JMSU1, offers promising material for the investigation of the biological properties of bladder cancer.

In vitro study of the effect of hyperthermia on normal bladder cell line and on five different transitional cell carcinoma cell lines

Intraluminal hyperthermia is potentially useful in the management of superficial bladder cancer. The potential inhibitory effect of hyperthermia on various human bladder cancer cell lines, normal human bladder cells and the murine MBT-2 bladder cancer cell line has been studied in vitro. These cell lines were exposed for one hour to 43 +/- 0.5C and compared to controls. Cell survival was assessed comparing the cell growth curve and colony formation. The human transitional cell carcinoma (TCC) cell lines vary in their sensitivity to heat. MGH-U1 was the most heat sensitive cell line. The human A-1698, CUB-2, UM-UC-3 and the murine MBT-2 lines were heat insensitive. We conclude that the cytocidal effect of hyperthermia in bladder transitional cell carcinoma is variable. Further experiments using the combination of hyperthermia and intravesical anticancer agents are in progress.

Isolation of clones from T24 cells and test of their sensitivity to adriamycin

Two single cell clones, CL3 and CL7, were developed from T24 cells. CL3 had abundant cytoplasmic granules, while CL7 did not have as much. CL3 and CL7 exhibited a modal number of chromosomes at 69 and 74, respectively. CL7 had a higher growth rate than CL3, as indicated by in vitro cell growth, plating efficiency, and growth of the tumors produced in nude mice. CL3 was slightly susceptible to adriamycin toxicity as compared to CL7.

Growth and characterization of multicellular tumor spheroids of human bladder carcinoma origin

We have examined the MGH-U1 human bladder carcinoma cell line and 12 primary bladder carcinoma biopsies for their ability to form spheroids in suspension culture and in multiwell dishes. MGH-U1 cells formed tightly packed spheroids with a necrotic center and viable rim whereas three sublines formed loose aggregates only. Spheroids formed from as few as 100 MGH-U1 cells placed into multiwells. MGH-U1 cells derived from spheroids formed new spheroids more rapidly and and consistently than cells derived from monolayer culture. Spheroid diameter increased at a rapid rate of approximately 100 microns/d in multiwell dishes, and necrosis occurred only in spheroids of diameter greater than 1 mm. Spheroids placed in spinner culture at a higher concentration (approximately 1.5 spheroids/ml) grew more slowly and developed necrosis at smaller diameters. The width of the viable rim of spheroids grown in spinner culture was maintained at approximately 190 microns over a wide range of spheroid diameters (400 to 1000 microns). Sequential trypsinization of spheroids, which stripped layers of cells from the spheroids, demonstrated no difference in the plating efficiency of cells derived from varying depths into the spheroid. Only one of the 12 primary bladder biopsy specimens demonstrated an ability to form spheroids. This biopsy, designated HB-10, formed spheroids that grew linearly over 40 d, formed colonies in methylcellulose culture and grew as xenografts in immune-deprived mice. These studies characterize the MGH-U1 spheroids that are useful in vitro models to study the effects of various treatments for solid tumors and demonstrate the limited capacity of cells from primary human bladder biopsies to form spheroids.

Establishment of cell strains from human urothelial carcinoma and their morphological characterization

We have examined the conditions for cultivation of enzymatically dispersed cells from 34 human urothelial transitional cell carcinomas (TCC) of various types. By employing two culture methods, stationary and tapping suspension, and by using the synthetic medium DM 160 supplement with human umbilical cord serum and fetal bovine serum, six cell strains were established. In two strains the tapping suspension culture method was suitable for growth of highly malignant cancer cells that detach easily from the glass surface in stationary cultures. Each of the six cell strains has been maintained in culture for over 30 months with repeated subcultures of 32 to 128 times. The histopathological features of the original TCC were three differentiated papillary types and three anaplastic nonpapillary types. In two cell strains from TCC with low malignancy, however, the cancer masses that formed in nude mice differed from the original TCC in which they became more malignant, and one cell strain resembled the original TCC closely. In three stationary culture cell strains the epithelial nature was demonstrated by the presence of desmosomes and tonofilaments. In one cell strain only tonofilaments were present. In two tapping suspension culture cell strains the presence of desmosomes was not shown clearly, but fine tonofilaments were observed in one cell strain.

Cellular heterogeneity in a tissue culture cell line derived from a human bladder carcinoma

To study heterogeneity in a cell line derived from a human bladder carcinoma (EJ), 7 clones were isolated at low passage and examined for differences in culture behaviour, ability to grow in agar and tumorigenicity in nude mice. The parent EJ line had several distinct chromosome populations (both diploid and tetraploid), grew in agar and produced tumours in nude mice. Three of the clones had pseudodiploid modes and 4 had either hypo- or hypertetraploid modes. The 7 clones had 5 marker chromosomes in common but the combination of other marker chromosomes made each clone unique. No significant difference was found between the clones in the in vitro growth rate although analysis of in vitro culture behaviour showed heterogeneity in the pattern of cell movement on plastic substratum. Three clones were composed of static cells, one clone had very mobile cells; the other clones had rates of movement intermediate between the two. Differences were also found in the packing density of the cloned cells and in the cell size. All 7 clones grew in agar but heterogeneity was seen between the clones as shown by widely varying colony-forming efficiencies (0.5-13%). One clone had a high colony-forming ability in agar but failed to produce tumours in nude mice. The other clones were tumorigenic regardless of colony-forming efficiency in agar. Specific chromosome abnormalities were found to be associated with growth in agar and tumorigenicity but not with the growth pattern or the rate of movement of the cloned cells in culture.

Chromosome pattern, growth in agar and tumorigenicity in nude mice of four human bladder carcinoma cell lines

Four human bladder carcinoma cell lines have been characterized by G-banding, and the chromosomal patterns correlated to growth in agar and tumorigenicity in nude mice. Each cell line was shown to be chromosomally unique and although numerical and structural anomalies were present, none were common to all four cell lines. However, one or more copies of a structurally altered chromosome 8 were present in all four cell lines and may be associated with tumorigenicity in nude mice. A combination of three marker chromosomes was found in the more anaplastic cell lines, but not in the two well-differentiated tumour cell lines. Growth in agar may be associated with the presence of the three marker chromosomes but was not correlated with tumorigenicity in nude mice.

Chemosensitivity of human bladder cancer cells in long-term culture and clinical responses to the selected anticancer drug

In vitro sensitivity of an established cell line from human urinary bladder cancer to various chemotherapeutic agents was determined by 14C-leucine incorporation into the target cells. Of 12 drugs tested, Carboquone, Neocarzinostatin, Actinomycin D, Adriamycin, Mitomycin C and Chromomycin A3 produced intensive cytotoxic effects, while Thio-Tepa, Bleomycin, 5-Fluorouracil and Vincirstine were less cytotoxic, Intravesical instillation of Carboquone, one of the most toxic agents in vitro, resulted in complete or partial tumor remission in 6 of 9 patients with bladder cancer. Prophylactic effects of periodic intravesical Carboquone were also indicated in 7 of 8 patients who had experienced recurring superficial bladder tumors.