While initiation is established as a critical step in tumorigenesis, the identity of the cell of origin for lung adenocarcinoma and the mechanism controlling susceptibility to initiation remain elusive. Here we show that lung tumor suppressor Gprc5aknockout (KO) mice are susceptible to initiation of lung tumorigenesis. Bronchioalveolar stem cells (BASC) and alveolar type 2 (AT2) cells were aberrantly expanded in Gprc5a-KO mouse lungs compared with those in wild-type (WT) mice, suggesting that Gprc5a-KO might confer susceptibility to initiation by increasing the cell of origin in mouse lungs. BASCs from Gprc5a-KO mice (KO-BASC) exhibited significantly increased stemness and self-renewal potential and reduced differentiation capacity compared with BASCs from WT mice (WT-BASC). AT2 cells did not possess self-renewal potential regardless of Gprc5a status. KO-BASCs expressed a stem-like gene profile with upregulated Abcg2, EGFR, and NF-kB signaling compared with WT-BASCs. Blockade of EGFR and NF-kB signaling inhibited both expansion of BASC and AT2 cells and lung tumorigenesis. Abcg2 was expressed in active KO-BASCs as well as in lung tumor cells but not in quiescent WT-BASCs or AT2 cells, supporting that lung adenocarcinoma cells are derived from Abcg2-positive KO-BASCs (active). Taken together, Gprc5a deletion leads to expansion of active BASCs via dysregulated EGFR and NF-kB signaling that confers susceptibility to initiation of lung tumorigenesis, marking Abcg2-positive BASCs as candidate cell of origin for lung adenocarcinoma. Significance: Identification of active bronchioalveolar stem cells as lung adenocarcinoma cells of origin provides insights into mechanisms of lung tumorigenesis and could facilitate development of effective strategies for cancer prevention and therapy.
|Number of pages||13|
|State||Published - Mar 15 2022|
Bibliographical noteFunding Information:
The authors thank Dr. Reuben Lotan for his generosity by providing Gprc5a-KO mice and Dr. C.B. Wilson for his generosity in providing SPC-dnIkBamice. They thank the core facility of Basic Medical Sciences, Shanghai Jiao Tong University School of Medicine. This work was supported by grants from National Nature Science Foundation of China (grant nos. 81620108022, 91129303, 91729302, and 81572759 to J. Deng; grants nos. 81601985 and 82173171 to H. Yin; grant no 82003069 to B. Jing; grant no. 82072570 to F. Yao; and grant no. 82002941 to B. Sun).
This work was supported by grants from National Nature Science Foundation of China (grant nos. 81620108022, 91129303, 91729302, and 81572759 to J. Deng; grants nos. 81601985 and 82173171 to H. Yin; grant no 82003069 to B. Jing; grant no. 82072570 to F. Yao; and grant no. 82002941 to B. Sun).
© 2022 American Association for Cancer Research.
ASJC Scopus subject areas
- Cancer Research