Although altered expression of each of the four cell cycle regulators is associated with bladder cancer outcome in patients undergoing radical cystectomy, p53 is the strongest predictor, followed by p21, suggesting a more pivotal role of the p53/p21 pathway in bladder cancer progression.

He et al. show that T reg deficiency markedly induces autoimmunity and shifts gut microbiota. Remodeling microbiota by Lactobacillus reuteri was found to inhibit autoimmunity via the metabolite inosine, which interacts with the adenosine A2A receptor. This finding establishes a link between the gut microbiota, A2A receptors, and autoimmunity induced by T reg cell deficiency.

We have produced prolonged, high local concentrations of interferon in vivo by intravesical instillation of adenoviruses encoding interferon-alpha (Ad-IFNalpha) together with the gene transfer-enhancing agent Syn3. We found sustained interferon protein levels for days, both in normal mouse urothelium and in human bladder cancer cells growing as superficial bladder tumors in nude mice using an orthotopic bladder model developed by us. Tumor burden in the bladder was determined utilizing cancer cells containing the green fluorescent protein. Marked tumor regression was observed following two 1-h exposures of Ad-IFNalpha/Syn3 and little or no cytotoxicity was detected in normal cells. Similar intravesical instillation of clinically relevant concentrations of IFN protein alone or Ad-IFNalpha without Syn3 was ineffective. Surprisingly, in vitro, Ad-IFNalpha also caused caspase-dependent death of bladder cancer cell lines that were resistant to high concentrations of IFN-alpha protein, including the cell line used in vivo. These findings demonstrate that Ad-IFNalpha can overcome resistance to IFN-alpha protein both in vitro and in vivo and support evaluation of intravesical Ad-IFNalpha/Syn3 for the treatment of superficial bladder cancer.

The methylation patterns that we observed suggest that exonic CpG islands are more susceptible to de novo methylation than promoter islands and that methylation may be seeded in exonic regions, from which it can spread to other islands, including promoter regions. Subsequent selection of cells with a growth advantage conferred by spread of methylation into and inactivation of a particular promoter might then contribute to the genesis of a specific type of cancer.

Recent studies have shown that patients whose bladder cancer exhibit overexpression of RB protein as measured by immunohistochemical analysis do equally poorly as those with loss of RB function. We hypothesized that loss of p16 protein function could be related to RB overexpression, since p16 can induce transcriptional downregulation of RB and its loss may lead to aberrant RB regulation. Conversely, loss of RB function has been associated with high p16 protein expression in several other tumor types. In the present study RB negative bladder tumors also exhibited strong nuclear p16 staining while each tumor with strong, homogeneous RB nuclear staining were p16 negative, supporting our hypothesis. To expand on these immunohistochemical studies additional cases were selected in which the status of the p16 encoding gene had been determined at the molecular level. Absent p16 and high RB protein expression was found in the tumors having loss of heterozygosity within 9p21 and a structural change (mutation or deletion) of the remaining p16 encoding gene allele, con®rming the staining results. These results strongly support the hypothesis that the RB nuclear overexpression recently associated with poor prognosis in bladder cancer is also associated with loss of p16 function and implies that loss of p16 function could be equally deleterious as RB loss in bladder and likely other cancers.

The search for the genomic sequences involved in human cancers can be greatly facilitated by maps of genomic imbalances identifying the involved chromosomal regions, particularly those that participate in the development of occult preneoplastic conditions that progress to clinically aggressive invasive cancer. The integration of such regions with human genome sequence variation may provide valuable clues about their overall structure and gene content. By extension, such knowledge may help us understand the underlying genetic components involved in the initiation and progression of these cancers. We describe the development of a genome-wide map of human bladder cancer that tracks its progression from in situ precursor conditions to invasive disease. Testing for allelic losses using a genome-wide panel of 787 microsatellite markers was performed on multiple DNA samples, extracted from the entire mucosal surface of the bladder and corresponding to normal urothelium, in situ preneoplastic lesions, and invasive carcinoma. Using this approach, we matched the clonal allelic losses in distinct chromosomal regions to specific NIH-PA Author ManuscriptNIH-PA Author Manuscript NIH-PA Author Manuscript phases of bladder neoplasia and produced a detailed genetic map of bladder cancer development. These analyses revealed three major waves of genetic changes associated with growth advantages of successive clones and reflecting a stepwise conversion of normal urothelial cells into cancer cells. The genetic changes map to six regions at 3q22-q24, 5q22-q31, 9q21-q22, 10q26, 13q14, and 17p13, which may represent critical hits driving the development of bladder cancer. Finally, we performed high-resolution mapping using single nucleotide polymorphism markers within one region on chromosome 13q14, containing the model tumor suppressor gene RB1, and defined a minimal deleted region associated with clonal expansion of in situ neoplasia. These analyses provided new insights on the involvement of several non-coding sequences mapping to the region and identified novel target genes, termed forerunner (FR) genes, involved in early phases of cancer development. Keywordsforerunner genes; whole-organ histologic and genetic mapping; high-resolution mapping with SNPs; dual-track pathway of bladder cancer development; apoptosisWe have developed a strategy to identify genetic hits across the entire mucosa of an affected organ relative to cancer progression, from in situ precursor conditions to invasive disease, on a total genomic scale. We used the approach, which we refer to as whole-organ histologic and genetic mapping (WOHGM), to identify clonal hits associated with growth advantage, thus tracking the development of human bladder cancer from occult in situ lesions. Human bladder carcinoma was used as a model of a common epithelial malignancy that develops by progression of microscopically recognizable intraurothelial preneoplastic conditions known as dysplasia and carcinoma in situ. 1 Carcinoma of the bladder is the fifth most frequent...

We used human bladder cancer as a model system and the whole-organ histologic and genetic mapping strategy to identify clonal genetic hits associated with growth advantage, tracking the evolution of bladder cancer from intraurothelial precursor lesions. Six putative chromosomal regions critical for clonal expansion of intraurothelial neoplasia and development of bladder cancer were identified by using this approach. Focusing on one of the regions, which includes the model tumor suppressor RB1, we performed allelotyping of single-nucleotide polymorphic sites and identified a 1.34-Mb segment around RB1 characterized by a loss of polymorphism associated with the initial expansion of in situ neoplasia. This segment contains several positional candidate genes referred to by us as forerunner genes that may contribute to such expansion. We subsequently concentrated our efforts on the two neighbor genes flanking RB1, namely ITM2B and CHC1L, as well as P2RY5, which is located inside RB1. Here, we report that ITM2B and P2RY5 modulated cell survival and were silenced by methylation or point mutations, respectively, and thus by functional loss may contribute to the growth advantage of neoplasia. We also show that homozygous inactivation of P2RY5 was antecedent to the loss of RB1 during tumor development, and that nucleotide substitutions in P2RY5 represent a cancer predisposing factor.bladder cancer ͉ single-nucleotide polymorphic sites ͉ whole-organ histologic and genetic mapping M any common epithelial cancers, including those arising in the bladder, begin as clonal in situ expansion of neoplastic cells, which show no or minimal deviation from the normal phenotype (1-4). Such lesions often form plaques involving large areas of the affected mucosa, and their expansion precedes the development of microscopically recognizable dysplasia or carcinoma in situ (4, 5). Identification of chromosomal regions associated with the initial expansion of neoplasia is a requisite for more specific studies of their positional candidate genes that may drive the initial clonal expansion of neoplasia.We have used an approach referred to as whole-organ histologic and genetic mapping (WOHGM) to identify clonal hits associated with growth advantage, tracking the evolution of human bladder cancer from occult in situ lesions to invasive disease on a total genomic scale (6-8). Human bladder carcinoma was used as a model of common epithelial malignancy that develops by progression of microscopically recognizable intraurothelial preneoplastic lesions ranging from mild dysplasia to carcinoma in situ (5). Bladder cancer was also selected because it is close to an ideal model human tumor to study the early events of carcinogenesis due to simple anatomy of the organ and the ease in mapping preneoplastic conditions geographically across the entire mucosa of cystectomy specimens (9-11).In this paper, we begin by presenting the identification of the six critical chromosomal regions that may contain genes driving the development of bladder cancer. Then, we f...

Purpose: RB94, a truncated form of RB110, has enhanced tumor suppressor potency and activity against all tumor types tested to date including bladder carcinoma. However, efficient, systemic delivery of the gene encoding RB94 specifically to tumors, is an obstacle to clinical application as an anticancer therapeutic. We have developed a systemically given, nanosized liposome DNA delivery system that specifically targets primary and metastatic disease.The ability of RB94, delivered via this nanocomplex, to sensitize bladder carcinoma to chemotherapy in vitro and in vivo was assessed. Experimental Design: The nanocomplex is an RB94 plasmid encapsulated by a cationic liposome, the surface of which is decorated with a tumor-targeting moiety, either transferrin (Tf/Lip/RB94) or an antitransferrin receptor single-chain antibody fragment (TfRScFv/Lip/ RB94). The ability of the complex to sensitize human bladder carcinoma HTB-9 cells to chemotherapeutics was assessed in vitro by XTTassay. In vivo tumor specificity and efficacy were tested in mice carrying HTB-9 tumors by PCR and tumor growth inhibition, respectively. Results: Transfection withTf/Lip/RB94 significantly sensitized HTB-9 cells to chemotherapeutic agents in vitro.Tumor specificity of the complex was shown in an orthotopic bladder tumor model by immunohistochemistry and PCR. Moreover, in mice bearing subcutaneous HTB-9 tumors, the combination of systemically givenTf/Lip/RB94 or TfRScFv/Lip/RB94 plus gemcitabine resulted in significant (P < 0.0005) tumor growth inhibition/regression and induction of apoptosis.Conclusions: Use of our tumor-targeting nanocomplex to specifically deliver the potent tumor suppressor RB94 efficiently to tumors has potential as a more effective treatment modality for genitourinary and other cancers.