Sleeping Beauty transposon-mediated screen identifies murine susceptibility genes for adenomatous polyposis coli (Apc)-dependent intestinal tumorigenesis

• Published in: Proceedings of the National Academy of Sciences - PNAS Vol. 108; no. 14; pp. 5765 - 5770
• Main Authors: Starr, Timothy K, Scott, Patricia M, Marsh, Benjamin M, Zhao, Lei, Than, Bich L.N, O'Sullivan, M. Gerard, Sarver, Aaron L, Dupuy, Adam J, Largaespada, David A, Cormier, Robert T
• Format: Journal Article
• Language: English
• Published: United States National Academy of Sciences 05-04-2011; National Acad Sciences
• Subjects: adenomatous polyposis coli; adenomatous polyposis coli protein; Alleles; Animals; Biological Sciences; Cancer; carcinogenesis; Cell Line, Tumor; Cell proliferation; cell viability; Cells; Colorectal cancer; colorectal neoplasms; Colorectal Neoplasms - genetics; Colorectal Neoplasms - pathology; Data processing; development aid; DNA Transposable Elements - genetics; epigenetics; Gene Silencing; Genes; Genetic loci; Genetic mutation; Genetic Predisposition to Disease - genetics; Genetic screening; Genetic Testing - methods; Genetic transposition; Genotype & phenotype; Humans; Insertion; Intestine; loci; Metastases; metastasis; Mice; Mice, Transgenic; Mutagenesis; Mutagenesis, Insertional - methods; mutants; Mutation; phenotype; Polyps; RNA Interference; RNA, Small Interfering - genetics; Rodents; transposon mutagenesis; Transposons; Tumorigenesis; Tumors
• ISSN: 0027-8424; 1091-6490
• DOI: 10.1073/pnas.1018012108

It is proposed that a progressive series of mutations and epigenetic events leads to human colorectal cancer (CRC) and metastasis. Furthermore, data from resequencing of the coding regions of human CRC suggests that a relatively large number of mutations occur in individual human CRC, most at low frequency. The functional role of these low-frequency mutations in CRC, and specifically how they may cooperate with high-frequency mutations, is not well understood. One of the most common rate-limiting mutations in human CRC occurs in the adenomatous polyposis coli (APC) gene. To identify mutations that cooperate with mutant APC, we performed a forward genetic screen in mice carrying a mutant allele of Apc (ApcMin) using Sleeping Beauty (SB) transposon-mediated mutagenesis. ApcMin SB-mutagenized mice developed three times as many polyps as mice with the ApcMin allele alone. Analysis of transposon common insertion sites (CIS) identified the Apc locus as a major target of SB-induced mutagenesis, suggesting that SB insertions provide an efficient route to biallelic Apc inactivation. We also identified an additional 32 CIS genes/loci that may represent modifiers of the ApcMin phenotype. Five CIS genes tested for their role in proliferation caused a significant change in cell viability when message levels were reduced in human CRC cells. These findings demonstrate the utility of using transposon mutagenesis to identify low-frequency and cooperating cancer genes; this approach will aid in the development of combinatorial therapies targeting this deadly disease.