Transposon Mutagenesis Screen Identifies Potential Lung Cancer Drivers and CUL3 as a Tumor Suppressor

Abstract

Non-small cell lung cancers (NSCLCs) harbor thousands of passenger events that hide genetic drivers. Even highly recurrent events in NSCLC, such as mutations in PTEN, EGFR, KRAS, and ALK, are only detected in, at most, 30% of patients. Thus, many unidentified low-penetrant events are causing a significant portion of lung cancers. To detect low-penetrance drivers of NSCLC a forward genetic screen was performed in mice using the Sleeping Beauty (SB) DNA transposon as a random mutagen to generate lung tumors in a Pten deficient background. SB mutations coupled with Pten deficiency were sufficient to produce lung tumors in 29% of mice. Pten deficiency alone, without SB mutations, resulted in lung tumors in 11% of mice, while the rate in control mice was ~3%. In addition, thyroid cancer and other carcinomas as well as the presence of bronchiolar and alveolar epithelialization in mice deficient for Pten were also identified. Analysis of common transposon insertion sites identified 76 candidate cancer driver genes. These genes are frequently dysregulated in human lung cancers and implicate several signaling pathways. Cullin3 (Cul3), a member of an ubiquitin ligase complex that plays a role in the oxidative stress response pathway, was identified in the screen and evidence demonstrates that Cul3 functions as a tumor suppressor.

Transposon mutagenesis identifies genes that cooperate with mutant Pten in breast cancer progression

“…In addition, in many cases, only a single transposon insertion was present at a CCG in tumor cells, suggesting that many CCGs are functioning as haploinsufficient TSGs. This is similar to what has been observed in other SB mutagenesis screens performed in solid tumors (18)(19)(20)(21)(22)(23)(24)(25)(26).…”

“…Identification of Trunk Driver Genes. Most CCGs identified by SB mutagenesis are thought to function during late stages of tumor progression (18)(19)(20)(21)(22)(23)(24)(25)(26). To identify the CCGs that function early in mammary tumor development, we selected transposon insertion sites represented by the highest number of sequencing reads (SB insertions in the CCG in ≥3 tumors with ≥9 reads per tumor), arguing that these insertions would be present in the largest number of tumor cells.…”

“…New technologies that would provide a more complete understanding of the genetics of TNBC are still needed to deconvolute the complexity of this deadly cancer. Our laboratory and others have pioneered the use of transposon mutagenesis in mice as a tool for cancer gene discovery (18)(19)(20)(21)(22)(23)(24)(25)(26). Transposons induce cancer by randomly inserting into the mouse genome, mutating, and disrupting potential cancer genes.…”

Molecular Evolution Patterns in Metastatic Lymph Nodes Reflect the Differential Treatment Response of Advanced Primary Lung Cancer

“…S3A and S3B). The p.L127V mutation in CUL3 known as a tumor suppressor in lung cancer (24) was detected in additional subclone of TH3 4R. Meanwhile TH4 and TH6 had additional subclones in specific metastatic tumors ( Supplementary Fig.…”

Identification of New Tumor Suppressor Genes in Triple-Negative Breast Cancer

“…The sleeping beauty (SB) transposon system has expanded the use of insertional mutagenesis for the study of many types of cancers (11)(12)(13)(14)(15)(16)(17)(18)(19)(20); and discovered candidate cancer genes (CCG) involved in the EMT and CSC pathways (21)(22)(23). To better understand the genes and pathways involved in the pathogenesis of TNBC, we performed an siRNA validation study of 40 SB-identified breast cancer TS genes identified in an SB mutagenesis screen performed in Pten mutant mice (24).…”