The impact of the MYB-NFIB fusion proto-oncogene in vivo.

Recurrent fusion of the v-myb avian myelobastosis viral oncogene homolog (MYB) and nuclear factor I/B (NFIB) generates the MYB-NFIB transcription factor, which has been detected in a high percentage of individuals with adenoid cystic carcinoma (ACC). To understand the functional role of this fusion protein in carcinogenesis, we generated a conditional mutant transgenic mouse that expresses MYB-NFIB along with p53 mutation in tissues that give rise to ACC: mammary tissue, salivary glands, or systemically in the whole body. Expression of the oncogene in mammary tissue resulted in hyperplastic glands that developed into adenocarcinoma in 27.

Kinase domain activation of FGFR2 yields high-grade lung adenocarcinoma sensitive to a Pan-FGFR inhibitor in a mouse model of NSCLC.

Somatic mutations in FGFR2 are present in 4% to 5% of patients diagnosed with non-small cell lung cancer (NSCLC). Amplification and mutations in FGFR genes have been identified in patients with NSCLCs, and clinical trials are testing the efficacy of anti-FGFR therapies. FGFR2 and other FGFR kinase family gene alterations have been found in both lung squamous cell carcinoma and lung adenocarcinoma, although mouse models of FGFR-driven lung cancers have not been reported.

Activation of the PD-1 pathway contributes to immune escape in EGFR-driven lung tumors.

Unlabelled: The success in lung cancer therapy with programmed death (PD)-1 blockade suggests that immune escape mechanisms contribute to lung tumor pathogenesis. We identified a correlation between EGF receptor (EGFR) pathway activation and a signature of immunosuppression manifested by upregulation of PD-1, PD-L1, CTL antigen-4 (CTLA-4), and multiple tumor-promoting inflammatory cytokines. We observed decreased CTLs and increased markers of T-cell exhaustion in mouse models of EGFR-driven lung cancer.

FOXO3 encodes a carcinogen-activated transcription factor frequently deleted in early-stage lung adenocarcinoma.

The FOXO family of transcription factors elicits cell cycle arrest, apoptosis, and resistance to various physiologic and pathologic stresses relevant to sporadic cancer, such as DNA damage and oxidative stress. Although implicated as tumor suppressors, FOXO genetic inactivation has not been observed in human cancer. In an investigation of the two major types of non-small cell lung cancer, here, we identify the FOXO3 gene as a novel target of deletion in human lung adenocarcinoma (LAC).

FoxO3a gene is a target of deletion in mouse lung adenocarcinoma.

Lung adenocarcinomas (LAC) of smokers and never-smokers differ from one another in epidemiology, and clinical and molecular characteristics. The pathogenetic differences between these tumors are potential biomarkers and therapeutic targets. Mouse carcinogenesis models of human LAC are proven tools applicable for the identification of these molecular changes.

FOXO3a elicits a pro-apoptotic transcription program and cellular response to human lung carcinogen nicotine-derived nitrosaminoketone (NNK).

Long-term carcinogen exposure exerts continuous pressure on key mechanisms that repair or eliminate carcinogen-damaged cells giving rise to selective failures that contribute to lung cancer. FOXO3a is a transcription factor that elicits a protective response to diverse cellular stresses. Although implicated as a tumor suppressor, its role in sporadic cancer is uncertain.

Mutant SOD1 in cell types other than motor neurons and oligodendrocytes accelerates onset of disease in ALS mice.

Dominant mutations in ubiquitously expressed superoxide dismutase (SOD1) cause familial ALS by provoking premature death of adult motor neurons. To test whether mutant damage to cell types beyond motor neurons is required for the onset of motor neuron disease, we generated chimeric mice in which all motor neurons and oligodendrocytes expressed mutant SOD1 at a level sufficient to cause fatal, early-onset motor neuron disease when expressed ubiquitously, but did so in a cellular environment containing variable numbers of non-mutant, non-motor neurons. Despite high-level mutant expression within 100% of motor neurons and oligodendrocytes, in most of these chimeras, the presence of WT non-motor neurons substantially delayed onset of motor neuron degeneration, increasing disease-free life by 50%.

Tumor escape in a Wnt1-dependent mouse breast cancer model is enabled by p19Arf/p53 pathway lesions but not p16 Ink4a loss.

Breast cancers frequently progress or relapse during targeted therapy, but the molecular mechanisms that enable escape remain poorly understood. We elucidated genetic determinants underlying tumor escape in a transgenic mouse model of Wnt pathway-driven breast cancer, wherein targeted therapy is simulated by abrogating doxycycline-dependent Wnt1 transgene expression within established tumors. In mice with intact tumor suppressor pathways, tumors typically circumvented doxycycline withdrawal by reactivating Wnt signaling, either via aberrant (doxycycline-independent) Wnt1 transgene expression or via acquired somatic mutations in the gene encoding beta-catenin.