Transdifferentiation of lung adenocarcinoma in mice with Lkb1 deficiency to squamous cell carcinoma.
ABSTRACT: Lineage transition in adenocarcinoma (ADC) and squamous cell carcinoma (SCC) of non-small cell lung cancer, as implicated by clinical observation of mixed ADC and SCC pathologies in adenosquamous cell carcinoma, remains a fundamental yet unsolved question. Here we provide in vivo evidence showing the transdifferentiation of lung cancer from ADC to SCC in mice: Lkb1-deficient lung ADC progressively transdifferentiates into SCC, via a pathologically mixed mAd-SCC intermediate. We find that reduction of lysyl oxidase (Lox) in Lkb1-deficient lung ADC decreases collagen disposition and triggers extracellular matrix remodelling and upregulates p63 expression, a SCC lineage survival oncogene. Pharmacological Lox inhibition promotes the transdifferentiation, whereas ectopic Lox expression significantly inhibits this process. Notably, ADC and SCC show differential responses to Lox inhibition. Collectively, our findings demonstrate the de novo transdifferentiation of lung ADC to SCC in mice and provide mechanistic insight that may have important implications for lung cancer treatment.
Project description:LKB1 regulates both cell growth and energy metabolism. It remains unclear how LKB1 inactivation coordinates tumor progression with metabolic adaptation in non-small cell lung cancer (NSCLC). Here in Kras(G12D);Lkb1(lox/lox) (KL) mouse model, we reveal differential reactive oxygen species (ROS) levels in lung adenocarcinoma (ADC) and squamous cell carcinoma (SCC). ROS can modulate ADC-to-SCC transdifferentiation (AST). Further, pentose phosphate pathway deregulation and impaired fatty acid oxidation collectively contribute to the redox imbalance and functionally affect AST. Similar tumor and redox heterogeneity also exist in human NSCLC with LKB1 inactivation. In preclinical trials toward metabolic stress, certain KL ADC can develop drug resistance through squamous transdifferentiation. This study uncovers critical redox control of tumor plasticity that may affect therapeutic response in NSCLC.
Project description:Adenosquamous lung tumours, which are extremely poor prognosis, may result from cellular plasticity. Here, we demonstrate lineage switching of KRAS+ lung adenocarcinomas (ADC) to squamous cell carcinoma (SCC) through deletion of Lkb1 (Stk11) in autochthonous and transplant models. Chromatin analysis reveals loss of H3K27me3 and gain of H3K27ac and H3K4me3 at squamous lineage genes, including Sox2, ?Np63 and Ngfr. SCC lesions have higher levels of the H3K27 methyltransferase EZH2 than the ADC lesions, but there is a clear lack of the essential Polycomb Repressive Complex 2 (PRC2) subunit EED in the SCC lesions. The pattern of high EZH2, but low H3K27me3 mark, is also prevalent in human lung SCC and SCC regions within ADSCC tumours. Using FACS-isolated populations, we demonstrate that bronchioalveolar stem cells and club cells are the likely cells-of-origin for SCC transitioned tumours. These findings shed light on the epigenetics and cellular origins of lineage-specific lung tumours.
Project description:Adenosquamous lung tumors may result from cellular plasticity. We demonstrate lineage switching of KRAS+ lung adenocarcinomas (ADC) to squamous cell carcinoma (SCC) through deletion of Lkb1 (Stk11) in autochthonous and transplant models. Chromatin analysis reveals loss of H3K27me3 and gain of H3K27ac and H3K4me3 at squamous lineage genes, included Sox2, ΔNp63 and Ngfr. SCC lesions have higher levels of the H3K27 methyltransferase EZH2 than the ADC lesions, but there is a clear lack of the essential Polycomb Repressive Complex 2 (PRC2) subunit EED in the SCC lesions. Overall design: We performed chromatin immunoprecipitation (ChIP) on microdissected tumors confirmed to be either ADC or SCC by histology and qPCR. The two activating marks, histone H3 lysine 4 tri-methylation (H3K4me3) and histone H3 lysine 27 acetylation (H3K27ac), and the PRC2 derived silencing mark, histone H3 lysine 27 tri-methylation (H3K27me3) were immunoprecipitated, followed by sequencing the chromatin bound DNA. Examination of 3 different histone modifications in 2 histological subtypes of mouse tumors
Project description:Our previous study revealed that S100A7 was selectively expressed in lung squamous cell carcinoma tissues but not in adenocarcinoma. Thus far, the functions of S100A7 in lung cancer have remained largely unknown. Here, we reveal that S100A7 overexpression facilitates the transdifferentiation from adenocarcinoma (ADC) to squamous carcinoma (SCC) in several lung cancer cells, which is confirmed by an increase in DNp63 expression and a decrease in thyroid transcription factor 1 (TTF1) and aspartic proteinase napsin (napsin A) expression. Further study finds that activation of the Hippo pathway induces S100A7 expression and further confirms that nuclear YAP acts as a repressor of S100A7 in H292 cells. Subsequently, we verify that TEAD1 is required for YAP transcriptional repression of S100A7. More importantly, we determine that S100A7 overexpression partially rescues lung ADC to SCC transdifferentiation inhibited by YAP overexpression in all tested cells, suggesting that S100A7 and YAP have the opposite effects on lung ADC to SCC conversion. Taken together, our study demonstrates for the first time that S100A7 not only functions as a facilitator of adenous-squamous carcinoma phenotypic transition in lung cancer cells but also that its expression is differentially regulated by the Hippo-YAP pathway.
Project description:Adenosquamous carcinoma (ASC) of the lung is an unusual histology type in non-small-cell lung cancers. Due to its rarity, the clinicopathological characteristics and survival outcomes of the lung ASC are incompletely understood. We used the Surveillance, Epidemiology, and End Results (SEER) database to enroll 203,208 eligible patients, including 4,245 ASC, 124,253 adenocarcinoma (ADC) and 74,710 squamous cell carcinoma (SCC) patients. To date, this is the largest cohort in a study for ASC of the lung. With regard to age, sex, race, year of diagnosis, tumor size and SEER stage, ASC was intermediate between ADC and SCC. However, compared with ADC and SCC patients, ASC patients presented with a higher tumor grade and lower prevalence of nodal metastasis. More ASC patients underwent surgery and a lower proportion underwent radiation treatment and chemotherapy. Kaplan-Meier analysis showed that ASC patients had a better prognosis than ADC and SCC patients, but stratified analysis showed that the prognosis of ASC patients was worse than that of ADC and SCC patients in surgery and non-surgery subgroup. Multivariate analysis further confirmed that the ASC histology type was a risk factor for poor prognosis with respect to ADC and SCC. Using the propensity score matching to 1:1 match ASC with ADC or SCC, we found that ASC patients had worse survival than ADC and SCC patients. Subgroup analysis further demonstrated that ASC was a more aggressive histology type with a worse prognosis. These results provided a deep understanding of ASC, which contributed to better clinical diagnosis and treatment.
Project description:BACKGROUND:Human papillomavirus (HPV)16 can be separated into genetic sub-lineages (A1-4, B1-4, C1-4, D1-4) which may have differential cervical cancer risk. METHODS:A next-generation sequencing assay was used to whole-genome sequence 7116 HPV16-positive cervical samples from well-characterised international epidemiological studies, including 2076 controls, 1878 squamous cell carcinoma (SCC) and 186 adenocarcinoma/adenosquamous cell carcinoma (ADC), and to assign HPV16 sub-lineage. Logistic regression was used to estimate region-stratified country-adjusted odds ratios (OR) and 95%CI. RESULTS:A1 was the most globally widespread sub-lineage, with others showing stronger regional specificity (A3 and A4 for East Asia, B1-4 and C1-4 for Africa, D2 for the Americas, B4, C4 and D4 for North Africa). Increased cancer risks versus A1 were seen for A3, A4 and D (sub)lineages in regions where they were common: A3 in East Asia (OR=2.2, 95%CI:1.0-4.7); A4 in East Asia (6.6, 3.1-14.1) and North America (3.8, 1.7-8.3); and D in North (6.2, 4.1-9.3) and South/Central America (2.2, 0.8-5.7), where D lineages were also more frequent in ADC than SCC (3.2, 1.5-6.5; 12.1, 5.7-25.6, respectively). CONCLUSIONS:HPV16 genetic variation can strongly influence cervical cancer risk. However, burden of cervical cancer attributable to different sub-lineages worldwide is largely driven by historical HPV16 sub-lineage dispersal.
Project description:LKB1 loss-of-function mutations, observed in ?30% of human lung adenocarcinomas, contribute significantly to lung cancer malignancy progression. We show that lysyl oxidase (LOX), negatively regulated by LKB1 through mTOR-HIF-1? signaling axis, mediates lung cancer progression. Inhibition of LOX activity dramatically alleviates lung cancer malignancy progression. Up-regulated LOX expression triggers excess collagen deposition in Lkb1-deficient lung tumors, and thereafter results in enhanced cancer cell proliferation and invasiveness through activation of ?1 integrin signaling. High LOX level and activity correlate with poor prognosis and metastasis. Our findings provide evidence of how LKB1 loss of function promotes lung cancer malignancy through remodeling of extracellular matrix microenvironment, and identify LOX as a potential target for disease treatment in lung cancer patients.
Project description:More than one-third of lung cancer worldwide occurring in China. However, the clinical profiles of lung cancer patients in the mainland of China are rarely reported and largely unknown. The objective of this study is to analyze the characteristics and time trends of newly diagnosed lung cancer cases during the past 5 years in East China.The data came from an academic tertiary care hospital of East China. Patients who were newly diagnosed as lung cancer from 2011 to 2015 were enrolled. All new cases got pathological supports by lung biopsy or surgery. Tumor staging was performed according to the seventh edition of the tumor node metastasis (TNM) classification of malignant tumors. The patients' disease information was collected from the database of the hospital information system (HIS).From 2011 to 2015, aggregately 5,779 patients, including 3,719 males and 2,060 females, were diagnosed as lung cancer. The major histologic subtypes of lung cancer were adenocarcinoma (ADC, 60.0%), squamous cell carcinoma (SCC, 25.6%), small cell lung cancer (SCLC, 8.5%), large cell carcinoma (0.6%), adenosquamous carcinoma (1%), other non-small cell carcinoma (1.6%) and unclassified or rare carcinoma (2.8%). ADC proportion of female was much higher than that of male. A higher proportion of advanced stage (stage IIIB, IV) of lung cancer existed in patients who were admitted to hospital due to respiratory or cancer related symptoms (RCRS) than those without RCRS. Smoking rate in male patients reached 80.2%, while it was only 2.7% in females. EGFR mutation existed in 66% of female and 37% of male patients with ADC.This study demonstrates the clinicopathologic characteristics of lung cancer patients from East China, including histologic composition, staging proportion, smoking prevalence and gene mutation status. During the past 5 years, the proportion of ADC has increased gradually whereas SCC decreased.
Project description:Lung squamous cell carcinoma (SCC) is a deadly disease for which current treatments are inadequate. We demonstrate that bi-allelic inactivation of Lkb1 and Pten in the mouse lung led to SCC that recapitulated the histology, gene expression and microenvironment found in human disease. Lkb1/Pten-null (LP) tumors expressed the squamous markers Krt5, p63 and Sox2, and transcriptionally resembled the basal subtype of human SCC. In contrast to mouse adenocarcinomas, the LP tumors contained immune populations enriched for tumor-associated neutrophils. Sca1+/Ngfr+ fractions were enriched for tumor propagating cells (TPCs) that could serially transplant the disease in orthotopic assays. TPCs in the LP model and Ngfr+ cells in human SCCs highly expressed Pdl1, suggesting a novel mechanism of immune escape for TPCs. We used microarrays to detail the gene expression profles among lung SCC tumor epitheial cell, lung ADC tumor epithelia cell and normal epithelial cells. Kras tumor stroma cells and LP tumor stroma cells were sorted by FACS, the cells were gated as EpCAM-/CD45+/CD31+
Project description:Lung squamous cell carcinoma (SCC) is a deadly disease for which current treatments are inadequate. We demonstrate that bi-allelic inactivation of Lkb1 and Pten in the mouse lung led to SCC that recapitulated the histology, gene expression and microenvironment found in human disease. Lkb1/Pten-null (LP) tumors expressed the squamous markers Krt5, p63 and Sox2, and transcriptionally resembled the basal subtype of human SCC. In contrast to mouse adenocarcinomas, the LP tumors contained immune populations enriched for tumor-associated neutrophils. Sca1+/Ngfr+ fractions were enriched for tumor propagating cells (TPCs) that could serially transplant the disease in orthotopic assays. TPCs in the LP model and Ngfr+ cells in human SCCs highly expressed Pdl1, suggesting a novel mechanism of immune escape for TPCs. We used microarrays to detail the gene expression profles among lung SCC tumor epitheial cell, lung ADC tumor epithelia cell and normal epithelial cells. Normal EpCAM+, Kras tumor EpCAM+ and LP tumor EpCAM+ were sorted by FACS, the cells were gating as EpCAM+/CD45-/CD31-