Tumor cells obtain and overexpress AT2 cell marker
Ontology highlight
ABSTRACT: Background: The tobacco carcinogen urethane causes lung adenocarcinomas (LUAD) in mice. They show high similarity to human LUAD of smokers, including driver KrasQ61R mutations. However, the time line of KRASQ61R mutation acquisition as well as the affected cell lineages are still obscure. Objectives: With this study we aim to identify which cells of the lung gain KrasQ61R mutations and when they occur in response to urethane treatment. Methods: Airway and alveolar GFP-lineage-marked mice received single urethane hits (1 g/Kg). Lungs were harvested at 0, 1, 2, 4, and 8 weeks and LUAD tumors were collected at 16, 24, and 32 weeks post-urethane. The DNA was subjected to digital droplet PCR interrogating the coexistence of GFP and KrasQ61R in the same DNA copy. RNA of tumors was submitted to sequencing for gene expression analysis. Results: Starting from even 1 week post-urethane, both airway and alveolar lineages suffered KrasQ61R mutations (2.57% of copies examined). In airway-labelled cells KrasQ61R mutations increased by 4.06% and 2.55% at 4 and 32 weeks post-urethane, respectively. In contrast, in alveolar-labelled cells KrasQ61R mutations declined by 5.92% and 6.12%. Strikingly, gene expression analysis on tumors revealed an over expression of alveolar markers whereas expression of airway marker genes decreased. Conclusion: After pulmonary tumor initiation by urethane, airway cells accumulate KrasQ61R mutations over time, whereas alveolar cells tend to lose them. However, tumor cells are over expressing alveolar cell markers and lose airway markers. Altogether, these results indicate that smoking-induced LUAD develops from club cells which acquire alveolar cell characteristics. These data provide further insights into the mechanisms underlying LUAD evolution in patients.
Project description:Lung adenocarcinoma (LUAD), commonly driven by KRAS mutations, is responsible for 7% of all cancer mortality. The first allele-specific KRAS inhibitors were recently approved in LUAD, but clinical benefit is limited by intrinsic and acquired resistance. LUAD predominantly arises from alveolar type 2 (AT2) cells, which function as facultative alveolar stem cells by self-renewing and replacing alveolar type 1 (AT1) cells. Using genetically engineered mouse models, patient-derived xenografts, and patient samples we found inhibition of KRAS promotes transition to a quiescent AT1-like cancer cell state in LUAD tumors. Similarly, suppressing Kras induced AT1 differentiation of wild-type AT2 cells upon lung injury. The AT1-like LUAD cells exhibited high growth and differentiation potential upon treatment cessation, whereas ablation of the AT1-like cells robustly improved treatment response to KRAS inhibitors. Our results uncover an unexpected role for KRAS in promoting intra-tumoral heterogeneity and suggest targeting alveolar differentiation may augment KRAS-targeted therapies in LUAD.
Project description:Lung adenocarcinoma (LUAD), commonly driven by KRAS mutations, is responsible for 7% of all cancer mortality. The first allele-specific KRAS inhibitors were recently approved in LUAD, but clinical benefit is limited by intrinsic and acquired resistance. LUAD predominantly arises from alveolar type 2 (AT2) cells, which function as facultative alveolar stem cells by self-renewing and replacing alveolar type 1 (AT1) cells. Using genetically engineered mouse models, patient-derived xenografts, and patient samples we found inhibition of KRAS promotes transition to a quiescent AT1-like cancer cell state in LUAD tumors. Similarly, suppressing Kras induced AT1 differentiation of wild-type AT2 cells upon lung injury. The AT1-like LUAD cells exhibited high growth and differentiation potential upon treatment cessation, whereas ablation of the AT1-like cells robustly improved treatment response to KRAS inhibitors. Our results uncover an unexpected role for KRAS in promoting intra-tumoral heterogeneity and suggest targeting alveolar differentiation may augment KRAS-targeted therapies in LUAD.
Project description:Lung cancer is the leading cause of cancer deaths worldwide. TP53 tumor suppressor gene mutations occur in 50% of lung adenocarcinomas (LUADs) and are linked to poor prognosis, but how p53 suppresses LUAD development remains enigmatic. We show here that p53 suppresses LUAD by governing cell state, by promoting alveolar type 1 (AT1) differentiation. Using mice expressing oncogenic Kras and null, wild-type, or hypermorphic p53 alleles in alveolar type 2 (AT2) cells, we observed graded effects of p53 on LUAD initiation and progression. RNA-sequencing and ATAC-sequencing of LUAD cells uncovered a p53-induced AT1 differentiation program during tumor suppression in vivo through direct DNA binding, chromatin remodeling, and AT1 gene induction. Single-cell transcriptomics analyses revealed that during LUAD evolution, p53 promotes AT1 differentiation through action in a transitional cell state analogous to a transient intermediary seen during AT2-to-AT1 differentiation in alveolar injury repair. Notably, p53 inactivation resulted in the inappropriate persistence of these transitional cancer cells accompanied by upregulated growth signaling and divergence from lung lineage identity, characteristics associated with LUAD progression. Analysis of p53wt and p53-null mice showed that p53 also directs alveolar regeneration after injury, by regulating AT2 self-renewal and promoting transitional cell differentiation into AT1 cells. Collectively, these findings illuminate mechanisms of p53-mediated LUAD suppression, in which p53 governs alveolar differentiation, and suggest that tumor suppression reflects a fundamental role of p53 in orchestrating tissue repair after injury.
Project description:Lung cancer is the leading cause of cancer deaths worldwide. TP53 tumor suppressor gene mutations occur in 50% of lung adenocarcinomas (LUADs) and are linked to poor prognosis, but how p53 suppresses LUAD development remains enigmatic. We show here that p53 suppresses LUAD by governing cell state, by promoting alveolar type 1 (AT1) differentiation. Using mice expressing oncogenic Kras and null, wild-type, or hypermorphic p53 alleles in alveolar type 2 (AT2) cells, we observed graded effects of p53 on LUAD initiation and progression. RNA-sequencing and ATAC-sequencing of LUAD cells uncovered a p53-induced AT1 differentiation program during tumor suppression in vivo through direct DNA binding, chromatin remodeling, and AT1 gene induction. Single-cell transcriptomics analyses revealed that during LUAD evolution, p53 promotes AT1 differentiation through action in a transitional cell state analogous to a transient intermediary seen during AT2-to-AT1 differentiation in alveolar injury repair. Notably, p53 inactivation resulted in the inappropriate persistence of these transitional cancer cells accompanied by upregulated growth signaling and divergence from lung lineage identity, characteristics associated with LUAD progression. Analysis of p53wt and p53-null mice showed that p53 also directs alveolar regeneration after injury, by regulating AT2 self-renewal and promoting transitional cell differentiation into AT1 cells. Collectively, these findings illuminate mechanisms of p53-mediated LUAD suppression, in which p53 governs alveolar differentiation, and suggest that tumor suppression reflects a fundamental role of p53 in orchestrating tissue repair after injury.
Project description:Lung cancer is the leading cause of cancer deaths worldwide. TP53 tumor suppressor gene mutations occur in 50% of lung adenocarcinomas (LUADs) and are linked to poor prognosis, but how p53 suppresses LUAD development remains enigmatic. We show here that p53 suppresses LUAD by governing cell state, by promoting alveolar type 1 (AT1) differentiation. Using mice expressing oncogenic Kras and null, wild-type, or hypermorphic p53 alleles in alveolar type 2 (AT2) cells, we observed graded effects of p53 on LUAD initiation and progression. RNA-sequencing and ATAC-sequencing of LUAD cells uncovered a p53-induced AT1 differentiation program during tumor suppression in vivo through direct DNA binding, chromatin remodeling, and AT1 gene induction. Single-cell transcriptomics analyses revealed that during LUAD evolution, p53 promotes AT1 differentiation through action in a transitional cell state analogous to a transient intermediary seen during AT2-to-AT1 differentiation in alveolar injury repair. Notably, p53 inactivation resulted in the inappropriate persistence of these transitional cancer cells accompanied by upregulated growth signaling and divergence from lung lineage identity, characteristics associated with LUAD progression. Analysis of p53wt and p53-null mice showed that p53 also directs alveolar regeneration after injury, by regulating AT2 self-renewal and promoting transitional cell differentiation into AT1 cells. Collectively, these findings illuminate mechanisms of p53-mediated LUAD suppression, in which p53 governs alveolar differentiation, and suggest that tumor suppression reflects a fundamental role of p53 in orchestrating tissue repair after injury.
Project description:Lung cancer is the leading cause of cancer deaths worldwide. TP53 tumor suppressor gene mutations occur in 50% of lung adenocarcinomas (LUADs) and are linked to poor prognosis, but how p53 suppresses LUAD development remains enigmatic. We show here that p53 suppresses LUAD by governing cell state, by promoting alveolar type 1 (AT1) differentiation. Using mice expressing oncogenic Kras and null, wild-type, or hypermorphic p53 alleles in alveolar type 2 (AT2) cells, we observed graded effects of p53 on LUAD initiation and progression. RNA-sequencing and ATAC-sequencing of LUAD cells uncovered a p53-induced AT1 differentiation program during tumor suppression in vivo through direct DNA binding, chromatin remodeling, and AT1 gene induction. Single-cell transcriptomics analyses revealed that during LUAD evolution, p53 promotes AT1 differentiation through action in a transitional cell state analogous to a transient intermediary seen during AT2-to-AT1 differentiation in alveolar injury repair. Notably, p53 inactivation resulted in the inappropriate persistence of these transitional cancer cells accompanied by upregulated growth signaling and divergence from lung lineage identity, characteristics associated with LUAD progression. Analysis of p53wt and p53-null mice showed that p53 also directs alveolar regeneration after injury, by regulating AT2 self-renewal and promoting transitional cell differentiation into AT1 cells. Collectively, these findings illuminate mechanisms of p53-mediated LUAD suppression, in which p53 governs alveolar differentiation, and suggest that tumor suppression reflects a fundamental role of p53 in orchestrating tissue repair after injury.
Project description:Lung cancer is the leading cause of cancer deaths worldwide. TP53 tumor suppressor gene mutations occur in 50% of lung adenocarcinomas (LUADs) and are linked to poor prognosis, but how p53 suppresses LUAD development remains enigmatic. We show here that p53 suppresses LUAD by governing cell state, by promoting alveolar type 1 (AT1) differentiation. Using mice expressing oncogenic Kras and null, wild-type, or hypermorphic p53 alleles in alveolar type 2 (AT2) cells, we observed graded effects of p53 on LUAD initiation and progression. RNA-sequencing and ATAC-sequencing of LUAD cells uncovered a p53-induced AT1 differentiation program during tumor suppression in vivo through direct DNA binding, chromatin remodeling, and AT1 gene induction. Single-cell transcriptomics analyses revealed that during LUAD evolution, p53 promotes AT1 differentiation through action in a transitional cell state analogous to a transient intermediary seen during AT2-to-AT1 differentiation in alveolar injury repair. Notably, p53 inactivation resulted in the inappropriate persistence of these transitional cancer cells accompanied by upregulated growth signaling and divergence from lung lineage identity, characteristics associated with LUAD progression. Analysis of p53wt and p53-null mice showed that p53 also directs alveolar regeneration after injury, by regulating AT2 self-renewal and promoting transitional cell differentiation into AT1 cells. Collectively, these findings illuminate mechanisms of p53-mediated LUAD suppression, in which p53 governs alveolar differentiation, and suggest that tumor suppression reflects a fundamental role of p53 in orchestrating tissue repair after injury.
Project description:Lung cancer is the leading cause of cancer deaths worldwide. TP53 tumor suppressor gene mutations occur in 50% of lung adenocarcinomas (LUADs) and are linked to poor prognosis, but how p53 suppresses LUAD development remains enigmatic. We show here that p53 suppresses LUAD by governing cell state, by promoting alveolar type 1 (AT1) differentiation. Using mice expressing oncogenic Kras and null, wild-type, or hypermorphic p53 alleles in alveolar type 2 (AT2) cells, we observed graded effects of p53 on LUAD initiation and progression. RNA-sequencing and ATAC-sequencing of LUAD cells uncovered a p53-induced AT1 differentiation program during tumor suppression in vivo through direct DNA binding, chromatin remodeling, and AT1 gene induction. Single-cell transcriptomics analyses revealed that during LUAD evolution, p53 promotes AT1 differentiation through action in a transitional cell state analogous to a transient intermediary seen during AT2-to-AT1 differentiation in alveolar injury repair. Notably, p53 inactivation resulted in the inappropriate persistence of these transitional cancer cells accompanied by upregulated growth signaling and divergence from lung lineage identity, characteristics associated with LUAD progression. Analysis of p53wt and p53-null mice showed that p53 also directs alveolar regeneration after injury, by regulating AT2 self-renewal and promoting transitional cell differentiation into AT1 cells. Collectively, these findings illuminate mechanisms of p53-mediated LUAD suppression, in which p53 governs alveolar differentiation, and suggest that tumor suppression reflects a fundamental role of p53 in orchestrating tissue repair after injury.
Project description:Lung cancer is the leading cause of cancer deaths worldwide. TP53 tumor suppressor gene mutations occur in 50% of lung adenocarcinomas (LUADs) and are linked to poor prognosis, but how p53 suppresses LUAD development remains enigmatic. We show here that p53 suppresses LUAD by governing cell state, by promoting alveolar type 1 (AT1) differentiation. Using mice expressing oncogenic Kras and null, wild-type, or hypermorphic p53 alleles in alveolar type 2 (AT2) cells, we observed graded effects of p53 on LUAD initiation and progression. RNA-sequencing and ATAC-sequencing of LUAD cells uncovered a p53-induced AT1 differentiation program during tumor suppression in vivo through direct DNA binding, chromatin remodeling, and AT1 gene induction. Single-cell transcriptomics analyses revealed that during LUAD evolution, p53 promotes AT1 differentiation through action in a transitional cell state analogous to a transient intermediary seen during AT2-to-AT1 differentiation in alveolar injury repair. Notably, p53 inactivation resulted in the inappropriate persistence of these transitional cancer cells accompanied by upregulated growth signaling and divergence from lung lineage identity, characteristics associated with LUAD progression. Analysis of p53wt and p53-null mice showed that p53 also directs alveolar regeneration after injury, by regulating AT2 self-renewal and promoting transitional cell differentiation into AT1 cells. Collectively, these findings illuminate mechanisms of p53-mediated LUAD suppression, in which p53 governs alveolar differentiation, and suggest that tumor suppression reflects a fundamental role of p53 in orchestrating tissue repair after injury.
Project description:The limited efficacy of currently approved immunotherapies in EGFR-mutant lung adenocarcinoma (LUAD) underscores the need to better understand alternative mechanisms governing local immunosuppression to fuel novel therapies. Elevated surfactant and GM-CSF secretion from the transformed epithelium induces tumor-associated alveolar macrophages (TA-AM) to proliferate and support tumor growth by rewiring inflammatory functions and lipid metabolism. TA-AM properties are driven by increased GM-CSF—PPARγ signaling and inhibition of airway GM-CSF or PPARγ in TA-AMs suppresses cholesterol efflux to tumor cells, which impairs EGFR phosphorylation and restrains LUAD progression. In the absence of TA-AM metabolic support, LUAD cells compensate by increasing cholesterol synthesis, and blocking PPARγ in TA-AMs simultaneous with statin therapy further suppresses tumor progression and increases T cell effector functions. These results reveal new therapeutic combinations for immunotherapy resistant EGFR-mutant LUADs and demonstrate how such cancer cells can metabolically co-opt TA-AMs through GM-CSF—PPARγ signaling to provide nutrients that promote oncogenic signaling and growth.