KrasG12D and Nkx2-1 haploinsufficiency induce mucinous adenocarcinoma of the lung
Yutaka Maeda, … , Takeshi Nagayasu, Jeffrey A. Whitsett
Yutaka Maeda, … , Takeshi Nagayasu, Jeffrey A. Whitsett
Published November 12, 2012
Citation Information: J Clin Invest. 2012;122(12):4388-4400. https://doi.org/10.1172/JCI64048.
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Research Article Oncology

KrasG12D and Nkx2-1 haploinsufficiency induce mucinous adenocarcinoma of the lung

Abstract

Mucinous adenocarcinoma of the lung is a subtype of highly invasive pulmonary tumors and is associated with decreased or absent expression of the transcription factor NK2 homeobox 1 (NKX2-1; also known as TTF-1). Here, we show that haploinsufficiency of Nkx2-1 in combination with oncogenic KrasG12D, but not with oncogenic EGFRL858R, caused pulmonary tumors in transgenic mice that were phenotypically similar to human mucinous adenocarcinomas. Gene expression patterns distinguished tumor goblet (mucous) cells from nontumorigenic airway and intestinal goblet cells. Expression of NKX2-1 inhibited urethane and oncogenic KrasG12D-induced tumorigenesis in vivo. Haploinsufficiency of Nkx2-1 enhanced KrasG12D-mediated tumor progression, but reduced EGFRL858R-mediated progression. Genome-wide analysis of gene expression demonstrated that a set of genes induced in mucinous tumors was shared with genes induced in a nontumorigenic chronic lung disease, while a distinct subset of genes was specific to mucinous tumors. ChIP with massively parallel DNA sequencing identified a direct association of NKX2-1 with the genes induced in mucinous tumors. NKX2-1 associated with the AP-1 binding element as well as the canonical NKX2-1 binding element. NKX2-1 inhibited both AP-1 activity and tumor colony formation in vitro. These data demonstrate that NKX2-1 functions in a context-dependent manner in lung tumorigenesis and inhibits KrasG12D-driven mucinous pulmonary adenocarcinoma.

Authors

Yutaka Maeda, Tomoshi Tsuchiya, Haiping Hao, David H. Tompkins, Yan Xu, Michael L. Mucenski, Lingling Du, Angela R. Keiser, Takuya Fukazawa, Yoshio Naomoto, Takeshi Nagayasu, Jeffrey A. Whitsett

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Figure 6

A subset of genes induced in the mucinous tumor model and the asthma model was suppressed by NKX2-1.

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A subset of genes induced in the mucinous tumor model and the asthma mod...
Shown are results from 3 sets of mRNA microarray analysis (for simplicity, symbols for the human genes only are shown). For analysis of genes induced in mucinous tumors, mRNAs were isolated from lungs of control and KrasG12D;Nkx2-1+/– mice and subjected to mRNA microarray analysis (n = 3 per group). For analysis of genes regulated by NKX2-1 in A549 human lung carcinoma cells, mRNAs were isolated from lentiviral Nkx2-1–expressing and control A549 cells and subjected to mRNA microarray analysis (n = 3 per group). For analysis of genes induced in asthma, mRNAs were isolated from lungs of control and HDM-challenged mice and subjected to mRNA microarray analysis (n = 3 per group) (23). Several mRNAs associated with mucous genes — AGR2, MUC5AC, and MUC5B — were induced in both the mucinous tumor and the asthma mouse models and suppressed by NKX2-1 in A549 human lung carcinoma cells. HNF4A, a non–lung lineage transcription factor, was suppressed by NKX2-1, a lung lineage transcription factor. SOX2, expressed in conducting airways but not in alveolar regions, was also suppressed by NKX2-1, and expressed in both conducting airways and alveoli.