Project description:Lung cancer is the leading cause of cancer mortality and is classified by the World Health Organization into two broad histological subtypes. Non–small cell lung cancer (NSCLC), including adenocarcinoma, squamous cell carcinoma, and large cell carcinoma, accounts for ~85% of all lung cancer cases, with the remaining 15% of cases being due to small cell lung cancer (SCLC), which arises from neuroendocrine cells in the lung. Although most SCLC tumors are initially responsive to chemotherapy and radiation, patients often experience relapse, with the tumor acquiring an aggressiveness and therapeutic resistance that lead to a poor clinical outcome. Improvement of overall survival in individuals with SCLC will require the identification of novel therapeutic targets based on a better understanding of the changes in intracellular signaling of aggressive SCLC cells. The malignant progression of SCLC often occurs concomitantly with the acquisition of chemoresistance, suggesting that phenotypic malignant change is related to adaptation to the stresses induced by chemotherapy. In order to analyze gene expression changes associated with malignant transformation in SCLC, we established a cisplatin-resistant SCLC cell line and performed RNA sequencing.
Project description:Malignant transformation of SCLC often occurs simultaneously with the acquisition of chemotherapy resistance, suggesting that phenotypic malignant transformation is associated with adaptation to chemotherapy-induced stress. Recently, it has been reported that autophagy deficiency is involved in chemotherapy resistance in SCLC. To analyze gene expression changes associated with SCLC malignant transformation, we established ATG7 knockout and ATG7/SQSTM1 double knockout SCLC cell lines and performed RNA sequencing.
Project description:Activating mutations of EGFR have been characterized as important mechanisms for carcinogenesis in a subset of EGFR-dependent non-small cell lung cancers (NSCLC). EGFR tyrosine kinase inhibitors (TKI), such as erlotinib and gefitinib, have dramatic clinical effects on EGFR-addicted lung cancers and are used as first-line therapy for EGFR-mutant tumors. However, eventually all tumors acquire secondary resistance to the drugs and progress. We established a model to better understand mechanisms of acquired resistance. NCI- HCC827 cells are EGFR-mutant and highly erlotinib-sensitive. In this study we exposed HCC827 cells to increasing concentrations of erlotinib and two highly erlotinib-resistant subclones were developed (ER3 and T15-2). In these subclones no acquired alterations of EGFR or MET were found. We hereby performed a gene expression microarray studies to understand changes that might explain mechanisms of resistance. Through these studies we demonstrated in one resistant clone (ER3) overexpression of AXL, a tyrosine kinase implicated in imatinib and lapatinib resistance. Gene expression profilings were measured in NSCLC cell line HCC827 and two erlotinib-resistant HCC827-originated sublines ER3 and T15-2.
Project description:Activating mutations of EGFR have been characterized as important mechanisms for carcinogenesis in a subset of EGFR-dependent non-small cell lung cancers (NSCLC). EGFR tyrosine kinase inhibitors (TKI), such as erlotinib and gefitinib, have dramatic clinical effects on EGFR-addicted lung cancers and are used as first-line therapy for EGFR-mutant tumors. However, eventually all tumors acquire secondary resistance to the drugs and progress. We established a model to better understand mechanisms of acquired resistance. NCI- HCC827 cells are EGFR-mutant and highly erlotinib-sensitive. In this study we exposed HCC827 cells to increasing concentrations of erlotinib and two highly erlotinib-resistant subclones were developed (ER3 and T15-2). In these subclones no acquired alterations of EGFR or MET were found. We hereby performed a gene expression microarray studies to understand changes that might explain mechanisms of resistance. Through these studies we demonstrated in one resistant clone (ER3) overexpression of AXL, a tyrosine kinase implicated in imatinib and lapatinib resistance.
Project description:Non Small Cell Lung Cancer (NSCLC) causes the premature death of over 1 million people worldwide each year, but remains inadequately understood at the molecular level. To provide new insights for NSCLC treatment we performed a molecular characterisation of wild type and platinum drugs resistance in A549 cells. Transcriptome profiling revealed contrasting patterns of gene expression in sensitive and resistant cells and identified genes whose expression was highly correlated with the platinum drugs. Our results revealed a gene set of 15 transcripts whose expression was highly correlated with platinum-resistance in NSCLC A549 cell lines.
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.