High-order interactions among genetic polymorphisms in nucleotide excision repair pathway genes and smoking in modulating bladder cancer risk.

Polymorphisms in nucleotide excision repair (NER) genes may cause variations in DNA repair capacity and increase susceptibility to bladder cancer through complex gene-gene and gene-smoking interactions. We applied two data mining approaches to explore high-order gene-gene and gene-environment interactions among 13 polymorphisms in nine major NER genes in 696 bladder cancer patients and 629 controls. Individually, only the XPD D312N variant genotypes exhibited a slightly increased risk for bladder cancer. In classification and regression tree analysis, we observed gene-gene interactions among CCNH V270A, ERCC6 M1097V and RAD23B A249V in ever smokers: smokers with the variant alleles at these three loci had an almost 30-fold increased risk of bladder cancer [odds ratio (OR): 29.6, 95% confidence interval (CI): 9.3-93.7]. When evaluating combined effect of above four single nucleotide polymorphisms, we found a significant gene dosage effect for increased bladder cancer risk with increasing numbers of unfavorable genotypes. Compared with individuals with less than 2 unfavorable genotypes, those with 2 unfavorable genotypes and more than 2 unfavorable genotypes exhibited increased bladder cancer risk with ORs of 1.14 (95% CI: 0.87-1.51) and 2.15 (95% CI: 1.56-2.97), respectively (P < 0.001). The risks were more evident in ever smokers with ORs of 1.43 (95% CI: 1.02-2.01) and 3.40 (95% CI: 2.24-5.15), respectively (P < 0.001). In multifactor dimensionality reduction (MDR) analysis, the five-factor model including smoking, CCNH V270A, ERCC6 M1097V, RAD23B A249V and XPD D312N had the best ability to predict bladder cancer risk. The contributions of these polymorphisms may jointly affect bladder cancer risk through gene-gene and gene-smoking interactions.

Depletion of c-myc with specific antisense sequences reverses the transformed phenotype in ras oncogene-transformed NIH 3T3 cells.

ras oncogene-transformed NIH 3T3 cells expressing glucocorticoid-inducible antisense c-myc cDNA transcripts at levels sufficient to deplete c-myc protein lost their transformed morphology and the ability to grow in soft agar; their ability to form tumors in nude mice was also impaired. These changes were dependent on the continuous expression of the antisense sequences. No major effects on plating efficiencies, growth rates in monolayer culture, or immortalization were observed in the revertant cells, indicating that the observed effects were not a toxic consequence of c-myc protein depletion. Transfection with the same vector expressing c-myc in the sense orientation or other control vectors had no effect on transformation. These results suggest that a certain minimum level of expression of c-myc is required for the maintenance of ras transformation in NIH 3T3 cells.

UM-SCP-1, a new human cell line derived from a prostatic squamous cell carcinoma.

A permanent cell line (UM-SCP-1) has been established from a primary squamous cell carcinoma of the prostate. UM-SCP-1 has been passaged 40 times and has been in culture for 22 months. The doubling time of this aneuploid cell line is approximately 36 hr. In nude mice, UM-SCP-1 produces rapidly growing tumors with distinct histological features of squamous cell carcinoma. UM-SCP-1 cells express pemphigus and pemphigoid antigens and bind antibodies to beta 2 microglobulin and HLA-A,B,C common antigen. Cells of this line are unreactive with anti-A and anti-B blood group typing sera, autologous serum, and monoclonal anti-HLA-DR antibodies.

Decreased connexin expression and intercellular communication in human bladder cancer cells.

Connexins make up a gene family encoding proteins that form intercellular channels known as gap junctions. Decreases in connexin expression and loss of intercellular communication have been associated with the malignant phenotype in some animal and human cells. The expression of connexin 26 and 43 mRNA was evaluated in cultured normal and malignant human urothelial cells. The normal urothelial cells were shown by Northern analysis to express both connexins. Increased confluence of the cultured normal human urothelial cells was associated with upregulation of connexin 26 mRNA. Connexin 26 mRNA expression was decreased in the bladder cancer cells. Using a human connexin 26 complementary DNA probe, nuclear run-on assays demonstrated that the decreased expression in the cancer cells was due to a failure of transcription. Southern blot analysis did not reveal any alterations in the genomic DNA. Assessment of gap junction function by scrape loading of lucifer yellow demonstrated dye transfer in normal urothelial cells but not in bladder cancer cells. Downregulation of connexin 26 mRNA was associated with functional loss of intercellular communication in the human bladder cancer cells. Connexin 43 expression varied considerably in the bladder cancer cell lines and did not correlate with dye transfer of lucifer yellow. These data suggest that alterations in the regulation of connexin 26 expression are associated with and may contribute to the malignant phenotype in bladder cancer.

Identification by monoclonal antibodies of an antigen shed by human bladder cancer cells.

The reactivities of two anti-bladder cancer monoclonal antibodies, AN43 and BB369, were characterized. AN43 and BB369 reacted with a majority (greater than 50%) of bladder cancer tissue sections tested by immunoperoxidase staining. When tested against a panel of 27 normal human tissues, AN43 and BB369 reacted only with urothelium and stomach. AN43 and BB369 showed identical binding patterns and competed for binding on bladder cancer cells, suggesting that the two antibodies react with identical or spatially close epitopes. Bound BB369 antibody was rapidly shed from the surface of viable UM-UC-9 human bladder cancer cells. The antigen was found in spent tissue culture medium from the UM-UC-9 human bladder cancer cell line. AN43 and BB369 define a shed bladder tumor-associated antigen with limited distribution on normal tissues. The antigen is different from bladder tumor-associated antigens defined by other monoclonal antibodies and may be useful for the diagnosis and follow-up of patients with bladder cancer.

Beta 4 integrin transfection of UM-UC-2 (human bladder carcinoma) cells: stable expression of a spontaneous cytoplasmic truncation mutant with rapid loss of clones expressing intact beta 4.

The alpha 6 beta 4 integrin is a component of the hemidesmosome, the anchoring structure in the basal membrane of epithelial cells. alpha 6 beta 4 expression is frequently altered in neoplastic cells. It is sometimes lost and sometimes overexpressed, which suggests that disruption of normal function is involved in neoplastic transformation. To examine the effect of this integrin on the growth and behavior of malignant cells that have lost beta 4, we transfected a full-length beta 4 cDNA into the UM-UC-2 cell line that expresses alpha 6 but not beta 4. Although large numbers of clones were obtained when a control vector was used in the transfection, only 12 clones could be isolated that expressed beta 4. Of these, only two beta 4-positive clones, clones 8 and 11, persisted long enough for further study. Clone 8 cells initially expressed beta 4, but within 2 weeks, all positive cells were lost from the culture. Clone 11 persisted in culture and retained strong surface expression of alpha 6 beta 4. Biochemical analysis and Western blotting revealed that this clone contained a truncated form of beta 4 that had lost the distal cytoplasmic domain. We conclude that expression of wild-type beta 4 in UM-UC-2 inhibits cell growth, presumably by an integrin-mediated signaling pathway. Clone 11 escaped from normal signaling because the cytoplasmic domain, a region essential for basal polar localization, was lost. The alpha 6 beta 4 integrin appears to have tumor suppressor activity in epithelial tumors.

MMAC1/PTEN inhibits cell growth and induces chemosensitivity to doxorubicin in human bladder cancer cells.

The development and progression of bladder cancer is associated with multiple alterations in the genome, including loss of chromosome 10. Recently, MMAC1/PTEN, a phosphatidylinositol phosphatase, has been mapped to chromosome 10q23. We previously demonstrated that MMAC1/PTEN has tumor suppressive properties in glioblastoma and prostate cancer. To investigate the efficacy of gene therapy with MMAC1/PTEN, we examined whether the exogenous introduction of MMAC1/PTEN via an adenoviral vector (Ad-MMAC) can inhibit tumor growth and reverse drug resistance to doxorubicin in human bladder cancer cells. Human bladder cancer cell lines UM-UC-3 and T24 were infected with Ad-MMAC to induce exogenous expression of MMAC1/PTEN. The cells were then analysed for cell growth and expression of phosphorylated protein kinase B (Akt/PKB) and MMAC1/PTEN. UM-UC-6dox, a doxorubicin resistant subline, was infected with Ad-MMAC to evaluate its role in reversing drug resistance to doxorubicin. We found that MMAC1/PTEN suppressed tumor growth in UM-UC-3 and T24 cells with arrest in the G1 phase of the cell cycle. We also showed that gene therapy with MMAC1/PTEN abrogated phosphorylated Akt/PKB expression in UM-UC-3, T24 and UMUC-6dox cells, and restored doxorubicin sensitivity in UM-UC-6dox. These data demonstrate that MMAC1/PTEN can induce growth suppression and increase sensitivity to doxorubicin in bladder cancer cells and suggest that the MMAC1/PTEN gene and its pathways can be therapeutic targets for bladder cancer.

Genetic mapping and DNA sequence-based analysis of deleted regions on chromosome 16 involved in progression of bladder cancer from occult preneoplastic conditions to invasive disease.

Histologic and genetic mapping with 30 hypervariable markers mapped to chromosome 16 were performed on 234 DNA samples of five cystectomy specimens from patients with invasive bladder cancer. Allelic losses of individual markers were related to microscopically identified precursor conditions in the entire bladder mucosa and invasive cancer. Their significance for the development and progression of neoplasia from in situ preneoplastic conditions to invasive disease was analysed by the nearest neighbor algorithm and binomial maximum likelihood analysis. Using this approach we identified five distinct regions of allelic losses defined by their flanking markers and predicted size as follows. p13.3(D16S418-D16S406, 1.2 cM), p13.1(D16S748-D16S287, 12.9 cM), q12 1(D16S409-D16S514, 24.0 cM), q22.1 (D16S496-D16S515, 5.4 cM), and q24 (D16S507-D16S511, 5.9 cM and D16S402-D16S413, 17.4 cM). The regions mapping to p13.1 and q24 were involved in early intraurothelial phases of bladder neoplasia such as mild to moderate dysplasia. On the other hand the deleted region mapping to p13.3 was involved in progression of severe dysplasia/carcinoma in situ to invasive bladder cancer. Testing of markers that exhibited statistically significant LOH in relation to progression of neoplasia from precursor conditions to invasive cancer on 28 tumors and voided urine samples from 25 patients with bladder cancer revealed that q12.1 showed LOH in 46.4% of tumor and 32.0% of voided urine samples. The LOH of a single marker D16S541 could be detected in approximately 28% of tumors and 20% of voided urine samples of patients with bladder cancer. These data imply that the deleted region centered around marker D16S541 spanning approximately 10 cM and flanked by D16S409 and D16S415 contains a novel putative tumor suppressor gene or genes playing an important role in the development of human bladder cancer. To facilitate more precise positional mapping and identification of pathogenetically relevant genes, we analysed of human genome contig and sequence databases spanning the deleted regions. Multiple known candidate genes and several smaller gene-rich areas mapping to the target regions of chromosome 16 were identified.

Superimposed histologic and genetic mapping of chromosome 9 in progression of human urinary bladder neoplasia: implications for a genetic model of multistep urothelial carcinogenesis and early detection of urinary bladder cancer.

The evolution of alterations on chromosome 9, including the putative tumor suppressor genes mapped to the 9p21-22 region (the MTS genes), was studied in relation to the progression of human urinary bladder neoplasia by using whole organ superimposed histologic and genetic mapping in cystectomy specimens and was verified in urinary bladder tumors of various pathogenetic subsets with longterm follow-up. The applicability of chromosome 9 allelic losses as non-invasive markers of urothelial neoplasia was tested on voided urine and/or bladder washings of patients with urinary bladder cancer. Although sequential multiple hits in the MTS locus were documented in the development of intraurothelial precursor lesions, the MTS genes do not seem to represent a major target for p21-23 deletions in bladder cancer. Two additional tumor suppressor genes involved in bladder neoplasia located distally and proximally to the MTS locus within p22-23 and p11-13 regions respectively were identified. Several distinct putative tumor suppressor gene loci within the q12-13, q21-22, and q34 regions were identified on the q arm. In particular, the pericentromeric q12-13 area may contain the critical tumor suppressor gene or genes for the development of early urothelial neoplasia. Allelic losses of chromosome 9 were associated with expansion of the abnormal urothelial clone which frequently involved large areas of urinary bladder mucosa. These losses could be found in a high proportion of urothelial tumors and in voided urine or bladder washing samples of nearly all patients with urinary bladder carcinoma.

Biomarker study of primary nonmetastatic versus metastatic invasive bladder cancer. National Cancer Institute Bladder Tumor Marker Network.

A cohort of 109 patients with primary transitional cell carcinomas, stages T2-T3, grade 2 or higher, was identified and further divided into two groups based on lymphatic metastasis at the time of cystectomy (n = 57 cases) or absence of detectable metastatic disease over a minimum of 5 years of follow-up after cystectomy (n = 52). Blocks corresponding to the primary tumor lesions were sectioned and distributed to different laboratories to be analyzed. Immunohistochemistry on deparaffinized tissue sections was conducted for evaluation of p53 nuclear overexpression (monoclonal antibody PAb1801), assessment of proliferative index (Ki-67 antigen-monoclonal antibody MIB1), and microvascular counts (factor VIII-related antigen). DNA content/ploidy studies were performed on material obtained from thick sections. A double-blinded strategy was used for the evaluation of laboratory data versus clinical parameters. The cutoff value for p53 nuclear overexpression was > or =20% of tumor cells displaying nuclear staining. The median values for MIB1 (> or =18% of tumor nuclear cell staining) and microvascular counts (> or =40 microvessels/area screened) were used as cutoff points for these two variables. The assessment of DNA content was conducted by classifying cases as diploid, tetraploid, or aneuploid. Statistical analyses were performed using the Fisher's Exact Test (2-tailed). Results revealed that none of the markers studied had a statistically significant correlation with the end point of the study, i.e., the presence of lymph node metastatic disease, in the cohort of patients studied, although an obvious trend for p53 was noted. It is concluded that alterations of p53, Ki-67 proliferative index, microvascular counts, and ploidy are not strongly associated with lymph node status in patients affected with high-stage, high-grade bladder cancer.

Reproducibility of p53 immunohistochemistry in bladder tumors. National Cancer Institute, Bladder Tumor Marker Network.

The National Cancer Institute Bladder Tumor Marker Network conducted a study to evaluate the reproducibility of immunohistochemistry for measuring p53 expression in bladder tumors. Fifty paraffin blocks (10 from each of the five network institutions) were chosen at random from among high-grade invasive primary bladder tumors. Two sections from each block were sent to each laboratory for staining and scoring, and then all sections were randomly redistributed among the laboratories for a second scoring. Intra- and interlaboratory reproducibility was assessed with regard to both staining and scoring. For overall assessments of p53 positivity, the results demonstrated that intralaboratory reproducibility was quite good. Concordance across the five participating laboratories was high for specimens exhibiting no or minimal nuclear immunostaining of tumor cells or high percentages of tumor cells with nuclear immunoreactivities. However, there was a reduced level of concordance on specimens with percentages of stained tumor cells in an intermediate range. The discordancies were due mainly to staining differences in one of the five laboratories and scoring differences in another laboratory. These results indicate that some caution must be used in comparing results across studies from different groups. Standardization of staining protocols and selection of a uniform threshold for binary interpretation of results may improve assay reproducibility between laboratories.

p53 and RB expression predict progression in T1 bladder cancer.

The optimal clinical management of minimally invasive (stage T1) bladder cancer is controversial. T1 bladder cancers share characteristics of both noninvasive (Ta) papillary cancer and high stage, muscle-invasive bladder cancers. Patients with T1 bladder cancer have a higher risk of cancer progression and death than do patients with Ta bladder cancer. However, this risk is much lower than that of patients with high-stage bladder cancers. Methods of identifying T1 bladder cancer patients at greatest risk for progression may significantly improve clinical management. We retrospectively evaluated two tumor suppressor genes, p53 and RB, as potential prognostic markers for progression in a cohort of 45 patients with pT1 bladder cancer. Median follow-up for these individuals was greater than 3.5 years. Of this group, 58% had altered p53 expression based on positive p53 immunostaining. Three patterns for RB nuclear protein staining were observed: absent, heterogeneous (normal), and strongly homogeneous. Progression-free survival was similar for patients with loss of RB protein expression and those with apparent overexpression of RB protein. Therefore, both staining patterns were considered abnormal. Patients with normal expression of both proteins (i.e., p53 negative and RB heterogeneously positive) had an excellent outcome, with no patient showing disease progression, whereas patients with abnormal expression of either or both proteins had a significant increase in progression (P = 0.04 and P = 0.005, respectively). These data support the stratification of T1 bladder cancer patients based on p53 and RB nuclear protein status and suggest that patients with normal protein expression for both genes can be managed conservatively, whereas patients with alterations in one and particularly both genes require more aggressive treatment.

Connexin 26 gene therapy of human bladder cancer: induction of growth suppression, apoptosis, and synergy with Cisplatin.

The connexin 26 (Cx26) gene encodes a protein involved in gap junctional intercellular communication and is a putative tumor suppressor. We constructed a Cx26 adenovirus vector (Ad-Cx26) and used it to infect human bladder cancer cell lines UM-UC-3, UM-UC-6, UM-UC-14, and T24. Infection with Ad-Cx26 suppressed the growth of these cell lines in vitro and prevented tumor formation in vivo. Cell cycle accumulation or arrest at the G(1) phase was noted in UM-UC-3 cells and at the G(2)/M phase in UM-UC-6, UM-UC-14, and T24 cells. Apoptosis was noted in UM-UC-3, UM-UC-6, and UM-UC-14 cells both in vitro and in vivo. These effects were not seen with control adenovirus (Ad-CTR) or mock infection. Ad-Cx26 did not significantly alter the growth of the immortalized normal human bladder cell line SV-HUC. Direct injection of Ad-Cx26 into established UM-UC-3 and UM-UC-14 tumors in nude mice resulted in Cx26 expression, apoptosis, and significantly decreased growth compared with Ad-CTR treated tumors. Delayed resumption of tumor growth was associated with loss of Cx26 expression. Combination therapy with Ad-Cx26 and cisplatin resulted in decreased growth in vitro compared with either agent alone. We explored combination therapy with Ad-Cx26 and cisplatin to improve the in vivo efficacy of Cx26 gene therapy. In vivo therapy with Ad-Cx26 and cisplatin resulted in long-term suppression of tumor growth. These data demonstrate that combining gene and chemotherapy can result in dramatic synergy in vivo.

Characterization of the DD23 tumor-associated antigen for bladder cancer detection and recurrence monitoring. Marker Network for Bladder Cancer.

Bladder cancer detection, monitoring, and prevention represent major problems that could be addressed with sensitive and specific biomarkers. The antigen recognized by the DD23 antibody, previously developed against a tumor-related antigen, was partially biochemically characterized, and its sensitivity and specificity in cancer detection and recurrence monitoring was evaluated. Quantitative fluorescence image analysis was used to quantify antigen content in exfoliated urothelial cells in a cross-section of patients with bladder cancers of all grades and stages and control populations. The antigen was found in tumor cells as well as normal-appearing urothelial cells, suggesting it represents a marker induced by the altered growth factor environment of a cancer-containing bladder. When used as a quantitative marker, the sensitivity for bladder cancer detection was 85%, and the specificity was 95%. No significant difference was seen between symptomatic and asymptomatic control populations, including patients with previous bladder cancers in the absence of a recurrence. In bladder cancer recurrence monitoring, results were consistently negative until just before detection of a recurrence. The biomarker reflects a "field effect" that occurs very late in tumorigenesis and seems to represent events common to most cancers involving the genitourinary tract. Western blotting showed the antibody recognized a dimeric protein. DD23 quantification in single cells may be particularly useful in targeting cystoscopic intervention for recurrence monitoring and, because of its high specificity, could be a tool for bladder cancer screening in high-risk groups.

An improved intravesical model using human bladder cancer cell lines to optimize gene and other therapies.

Orthotopic implantation of human bladder cancer cells into immunodeficient mice is an important tool for studying the biology and effects of therapy. Nevertheless, the incidence of tumor implantation and growth by transurethral instillation of the human bladder cancer cells into murine bladders has been low or not reproducible. However, using a modified intravesical technique and the human bladder cancer cell lines, KU-7 and UM-UC-2, we have been able to obtain a high and reproducible incidence of superficial bladder tumors. Furthermore, intravesical administration of the LacZ adenovirus vector resulted in significant beta-galactosidase expression in these bladder tumors as well as the normal urothelium, which was associated with the removal of the glycosoaminoglycan layer. Because this modified technique produces a high incidence of superficial human tumor growth and allows the efficacy of gene transfer to be evaluated, it should be a useful model for the study of intravesical gene therapy for human bladder cancer.

Localization of the prostatic apex for radiation therapy using implanted markers.

PURPOSE: This report concentrates on the localization of the prostatic apex using implantable markers, and a comparison to localization defined by computed tomography (CT) and retrograde urethrography. METHODS AND MATERIALS: Fifteen patients were entered into a prospective trial and scheduled to undergo (a) pelvic CT, (b) retrograde urethrogram, and (c) transrectal ultrasound with placement of radiodense markers. Three markers were implanted: one was placed at the trapezoid area (prostatic apex), and the others placed lateral to the base of each seminal vesicle. The retrograde urethrogram was performed using standard technique. The superior-inferior distance between the apex identified by the marker placed at the prostatic apex and the other studies was measured. RESULTS: CT and urethrogram overestimated the inferior extent of the prostatic apex when compared to the location as defined by the implanted marker. With CT, the average distance from the marker to the CT-defined apex was 0.6 cm (95% C.I.--0.4-0.8 cm). With urethrogram, the average distance from the marker to the urethrogram-defined apex was 1.3 cm (95% C.I.--0.7-1.9 cm). When CT and urethrogram were compared, CT was more accurate in identifying the prostatic apex. CONCLUSION: Under ultrasound guidance, radiodense markers have been implanted into the prostate. This has revealed that the apex is localized superior to the apical margin as defined by retrograde urethrogram and CT, and that CT may be more accurate than retrograde urethrogram. In addition, the placement of multiple markers yields spatial information on prostatic position that can be extracted from megavoltage portal images.

Significance of downstaging in muscle-invasive bladder cancer treated with preoperative radiotherapy.

PURPOSE: The relationship between clinical-to-pathologic downstaging and patient outcome following preoperative radiotherapy was examined, focusing on the mechanism (selection vs. treatment effect) responsible for the benefit seen from such downstaging. METHODS AND MATERIALS: Three hundred and one patients were treated with preoperative radiotherapy plus cystectomy (PREOP) to a median dose of 50 Gy in 25 fractions between 1960-1983. These patients were compared to 225 patients treated with radical cystectomy, with or without chemotherapy (CYST), between 1984-1990. Multiagent chemotherapy was given to 68% of those in the CYST group and was not given to any in the PREOP group. Lymph node involvement was not formally evaluated in the PREOP group, while 20% had pathologic involvement in the CYST group. RESULTS: Clinical-to-pathologic downstaging (P < T stage) was found in 73% treated with PREOP and 29% treated with CYST (p < 0.0001, chi-square). The only factors that correlated with P < T staging for the PREOP and CYST groups when each was considered separately were clinical stage, blood urea nitrogen level, and creatinine level (p < 0.05, chi-square). Multivariate logistic regression revealed that treatment (PREOP vs. CYST) correlated independently with P < T staging (p < 0.0001). The relationship of actuarial local control to distant metastasis at 5 years in patients that were downstaged, as stratified by clinical stage and treatment, was then examined. Local control rates for P < T staged T2/T3a patients were independent of treatment (PREOP vs. CYST), while distant metastasis rates were significantly greater for those in the PREOP group. In contrast, P < T staged T3b patients in the PREOP group had significantly better local control and distant metastasis rates. CONCLUSIONS: Significantly higher P < T staging rates were observed with PREOP as compared to CYST, and this was a consequence of the radiotherapy given. The relationship of downstaging from radiotherapy to local control and distant metastasis was contingent on clinical stage. The results of Stage T2/T3a and T3b patients were divergent and supported treatment effect, rather than selection, as the mechanism consistent with the patient outcomes observed.

Combined effect of chemopreventive agent N-(4-hydroxyphenyl) retinamide (4-HPR) and gamma-radiation on bladder cancer cell lines.

The incidence of bladder cancer has increased in the United States during the past 50 years, consistent with increased exposure to bladder carcinogens in the environment and tobacco use. Although N-(4-hydroxyphenyl) retinamide (4-HPR), a retinoid derivative, has been used as a chemopreventive agent of bladder cancer in clinical trials, little is known about its mechanisms of action against bladder cancer cells. Previous studies suggest this chemopreventive agent may inhibit tumor growth by inducing apoptosis. To further investigate this putative effect, we examined the effect of 4-HPR and gamma-radiation and their combined effects in three selected bladder cancer cell lines. Indeed, 4-HPR induced apoptosis in these cell lines in a dose-dependent manner. A 2.5 microM dose of 4-HPR and 50 rad of gamma-irradiation induced about 10% increase in apoptotic cells, respectively. However, this low dose 4-HPR combined with low dose gamma-irradiation had a synergistic effect on apoptosis, in which apoptotic cells increased by more than 30%. The findings have potential clinical implications and warrant further investigations both in vitro and in vivo in bladder cancer.

Radioimmunodetection of a transplantable human bladder carcinoma in a nude mouse.

The results of an in vitro mixed hemadsorption (MHA) assay predicted the success of in vivo tumor localization using a radioiodinated, monoclonal, IgG1 antibody (A2) with reactivity to the human bladder carcinoma cell line RT4. In vitro, murine monoclonal antibodies A2 and G6, demonstrated reactivity to RT4 with titers of 1/1024 and 1/4 by MHA assay, respectively. In vivo results obtained with RT4 xenografts in athymic nude, Balb/c, mice indicated tumor uptakes of 1.10% dose/gram with A2 and 0.29% dose/gram with G6 at seven days after radiotracer injection. Successful scintigraphic imaging of tumor xenografts was achieved with A2 but not with G6 or radioiodinated mouse serum albumin.

DNA and PCNA content of renal cell carcinoma and prognosis.

Robson stage I or II renal carcinomas have a heterogenous clinical outcome. A variety of morphologic features and other parameters have been proposed as prognostically useful. The authors measured the DNA content and PCNA expression of 47 stage I or II renal carcinomas, and assessed the association of these measures with pathologic stage, nuclear grade, and clinical course. Approximately 56% of stage I neoplasms and 40% of stage II neoplasms were diploid. Five of 9 neoplasms in which multiple samples were analyzed manifested both aneuploid and diploid regions. PCNA expression was noted in 20 of 32 stage I neoplasms and 9 of 15 stage II neoplasms, and varied greatly among the neoplasms. Neither ploidy nor PCNA expression is associated with clinical behavior in these data. These results are different from some of those previously reported by others. These discrepancies are likely to be due to differences in methodology and the fact that there were only eight cases of metastatic disease. No single parameter will serve as a completely accurate prognostic indicator. Most individuals with these neoplasms will do well because all of the tumor has been excised.