Project description:The model is based on publication:
Mathematical analysis of gefitinib resistance of lung adenocarcinoma caused by MET amplification
Abstract:
Gefitinib, one of the tyrosine kinase inhibitors of epidermal growth factor receptor (EGFR), is effective for treating lung adenocarcinoma harboring EGFR mutation; but later, most cases acquire a resistance to gefitinib. One of the mechanisms conferring gefitinib resistance to lung adenocarcinoma is the amplification of the MET gene, which is observed in 5–22% of gefitinib-resistant tumors. A previous study suggested that MET amplification could cause gefitinib resistance by driving ErbB3-dependent activation of the PI3K pathway. In this study, we built a mathematical model of gefitinib resistance caused by MET amplification using lung adenocarcinoma HCC827-GR (gefitinib resistant) cells. The molecular reactions involved in gefitinib resistance consisted of dimerization and phosphorylation of three molecules, EGFR, ErbB3, and MET were described by a series of ordinary differential equations. To perform a computer simulation, we quantified each molecule on the cell surface using flow cytometry and estimated unknown parameters by dimensional analysis. Our simulation showed that the number of active ErbB3 molecules is around a hundred-fold smaller than that of active MET molecules. Limited contribution of ErbB3 in gefitinib resistance by MET amplification is also demonstrated using HCC827-GR cells in culture experiments. Our mathematical model provides a quantitative understanding of the molecular reactions underlying drug resistance.
Project description:The NKX2-1 transcription factor, a regulator of normal lung development, is the most significantly amplified gene in human lung adenocarcinoma. To better understand how genomic alterations of NKX2-1 drive tumorigenesis, we generated an expression signature associated with NKX2-1 amplification in human lung adenocarcinoma, and analyzed DNA binding sites of NKX2-1 by genome-wide chromatin immunoprecipitation from NKX2-1-amplified human lung adenocarcinoma cell lines. Combining these expression and cistromic analyses identified LMO3, itself encoding a transcription regulator, as a candidate direct transcriptional target of NKX2-1, in addition to consensus binding motifs including a nuclear hormone receptor signature and a Forkhead box motif in NKX2-1-bound sequences. RNA interference analysis of NKX2-1-amplified cells compared to non-amplified cells demonstrated that LMO3 mediates cell proliferation downstream of NKX2-1; cistromic analysis that NKX2-1 may cooperate with FOXA1. Our findings provide new insight into the transcriptional regulatory network of NKX2-1 and suggest that LMO3 is a transducer of lineage specific cell survival of NKX2-1-amplified lung adenocarcinomas. NKX2-1 ChIP-seq from three lung adenocarcinoma cell lines with amplification of NKX2-1
Project description:Understanding cellular processes underlying early lung adenocarcinoma (LUAD) development is needed to devise intervention strategies. Here, we performed whole exome sequencing (WES) of human treatment-naive lungs comprising various stages in the sequence of pathogenesis of LUAD including normal lung tissues, atypical adenomatous hyperplasia (AAH), adenocarcinoma in situ (AIS), minimally invasive adenocarcinoma (MIA) and LUAD.
Project description:The NKX2-1 transcription factor, a regulator of normal lung development, is the most significantly amplified gene in human lung adenocarcinoma. To better understand how genomic alterations of NKX2-1 drive tumorigenesis, we generated an expression signature associated with NKX2-1 amplification in human lung adenocarcinoma, and analyzed DNA binding sites of NKX2-1 by genome-wide chromatin immunoprecipitation from NKX2-1-amplified human lung adenocarcinoma cell lines. Combining these expression and cistromic analyses identified LMO3, itself encoding a transcription regulator, as a candidate direct transcriptional target of NKX2-1, in addition to consensus binding motifs including a nuclear hormone receptor signature and a Forkhead box motif in NKX2-1-bound sequences. RNA interference analysis of NKX2-1-amplified cells compared to non-amplified cells demonstrated that LMO3 mediates cell proliferation downstream of NKX2-1; cistromic analysis that NKX2-1 may cooperate with FOXA1. Our findings provide new insight into the transcriptional regulatory network of NKX2-1 and suggest that LMO3 is a transducer of lineage specific cell survival of NKX2-1-amplified lung adenocarcinomas.
Project description:Adenylate kinase 2 (AK2) is a wide-spread and highly conserved protein kinase whose main function is to catalyze the exchange of nucleotide phosphate groups. In this study, we showed that AK2 regulated tumor cell metastasis in lung adenocarcinoma. Positive expression of AK2 is related to lung adenocarcinoma progression and poor survival of patients. Knockdown or knockout of AK2 inhibited, while overexpression of AK2 promoted, human lung adenocarcinoma cell migration and invasion ability. Differential proteomics results showed that AK2 might be closely related to epithelial-mesenchymal transition (EMT). Further research indicated that AK2 regulated EMT occurrence through the Smad-dependent classical signaling pathways as measured by western blot and qPCR assays. Additionally, in vivo experiments showed that AK2-knockout in human lung tumor cells reduced their EMT-like features and formed fewer metastatic nodules both in liver and in lung tissues. In conclusion, we uncover a cancer metastasis-promoting role for AK2 and provide a rationale for targeting AK2 as a potential therapeutic approach for lung cancer.