Forerunner genes contiguous to RB1 contribute to the development of in situ neoplasia.

TitleForerunner genes contiguous to RB1 contribute to the development of in situ neoplasia.
Publication TypeJournal Article
Year of Publication2007
AuthorsLee, S, Jeong, J, Majewski, T, Scherer, SE, Kim, M-S, Tuziak, T, Tang, KS, Baggerly, K, Grossman, HBarton, Zhou, J-H, Shen, L, Bondaruk, J, Ahmed, SS, Samanta, S, Spiess, P, Wu, X, Filipek, S, McConkey, D, Bar-Eli, M, Issa, J-P, Benedict, WF, Czerniak, B
JournalProc Natl Acad Sci U S A
Volume104
Issue34
Pagination13732-7
Date Published2007 Aug 21
ISSN0027-8424
KeywordsBase Sequence, Gene Expression Regulation, Neoplastic, Humans, Loss of Heterozygosity, Models, Molecular, Polymorphism, Genetic, Protein Structure, Tertiary, Receptors, Purinergic P2, Retinoblastoma Protein, Urinary Bladder Neoplasms
Abstract

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.

DOI10.1073/pnas.0701771104
Alternate JournalProc. Natl. Acad. Sci. U.S.A.
PubMed ID17702869
PubMed Central IDPMC1949496
Grant ListP50 CA091846 / CA / NCI NIH HHS / United States
U01CA85078 / CA / NCI NIH HHS / United States
R01CA066723 / CA / NCI NIH HHS / United States
P50CA91846 / CA / NCI NIH HHS / United States
U01 CA085078 / CA / NCI NIH HHS / United States
R01 CA066723 / CA / NCI NIH HHS / United States