Selective Loss of RB in Resistant EGFR Mutant Lung Adenocarcinomas that Transform to SCLC [CGH]
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ABSTRACT: The study was designed to identify the molecular changes that occur in EGFR mutant NSCLCs that become resistant to TKI by transforming to SCLC. Tyrosine kinase inhibitors (TKIs) are effective treatments for non-small cell lung cancers (NSCLCs) with epidermal growth factor receptor (EGFR) mutations. However, they do not lead to cures, and, on average, relapse occurs after one year of continuous treatment. In a subset of patients, a fundamental histological transformation from NSCLC to small cell lung cancer (SCLC) is observed in the resistant cancers, but the molecular changes associated with this transformation remain unknown. Analysis of a cohort of tumor samples and cell lines derived from resistant EGFR mutant patients with SCLC transformation revealed that RB is lost in 100% of these cases, but rarely in those that remain NSCLC. Global changes in gene expression, including increased neuroendocrine marker expression and absence of EGFR expression, are observed in cancers that transformed to SCLC. Consistent with their genetic and epigenetic similarities to classical SCLC, cell lines derived from resistant EGFR mutant SCLC biopsies are substantially more sensitive to ABT-263 treatment compared to those derived from resistant EGFR mutant NSCLCs. Together, these findings suggest that despite developing initially as EGFR mutant adenocarcinomas, this subset of resistant cancers ultimately take on many of the molecular and phenotypic characteristics of classical SCLC. Overall, we completed array CGH analysis on 4 tumor specimens from EGFR mutant, TKI-resistant patients. Three of these samples had transformed to SCLC and one remained NSCLC.
Project description:The study was designed to identify the molecular changes that occur in EGFR mutant NSCLCs that become resistant to TKI by transforming to SCLC. Tyrosine kinase inhibitors (TKIs) are effective treatments for non-small cell lung cancers (NSCLCs) with epidermal growth factor receptor (EGFR) mutations. However, they do not lead to cures, and, on average, relapse occurs after one year of continuous treatment. In a subset of patients, a fundamental histological transformation from NSCLC to small cell lung cancer (SCLC) is observed in the resistant cancers, but the molecular changes associated with this transformation remain unknown. Analysis of a cohort of tumor samples and cell lines derived from resistant EGFR mutant patients with SCLC transformation revealed that RB is lost in 100% of these cases, but rarely in those that remain NSCLC. Global changes in gene expression, including increased neuroendocrine marker expression and absence of EGFR expression, are observed in cancers that transformed to SCLC. Consistent with their genetic and epigenetic similarities to classical SCLC, cell lines derived from resistant EGFR mutant SCLC biopsies are substantially more sensitive to ABT-263 treatment compared to those derived from resistant EGFR mutant NSCLCs. Together, these findings suggest that despite developing initially as EGFR mutant adenocarcinomas, this subset of resistant cancers ultimately take on many of the molecular and phenotypic characteristics of classical SCLC.
Project description:The study was designed to identify the molecular changes that occur in EGFR mutant NSCLCs that become resistant to TKI by transforming to SCLC. Tyrosine kinase inhibitors (TKIs) are effective treatments for non-small cell lung cancers (NSCLCs) with epidermal growth factor receptor (EGFR) mutations. However, they do not lead to cures, and, on average, relapse occurs after one year of continuous treatment. In a subset of patients, a fundamental histological transformation from NSCLC to small cell lung cancer (SCLC) is observed in the resistant cancers, but the molecular changes associated with this transformation remain unknown. Analysis of a cohort of tumor samples and cell lines derived from resistant EGFR mutant patients with SCLC transformation revealed that RB is lost in 100% of these cases, but rarely in those that remain NSCLC. Global changes in gene expression, including increased neuroendocrine marker expression and absence of EGFR expression, are observed in cancers that transformed to SCLC. Consistent with their genetic and epigenetic similarities to classical SCLC, cell lines derived from resistant EGFR mutant SCLC biopsies are substantially more sensitive to ABT-263 treatment compared to those derived from resistant EGFR mutant NSCLCs. Together, these findings suggest that despite developing initially as EGFR mutant adenocarcinomas, this subset of resistant cancers ultimately take on many of the molecular and phenotypic characteristics of classical SCLC.
Project description:The study was designed to identify the molecular changes that occur in EGFR mutant NSCLCs that become resistant to TKI by transforming to SCLC. Tyrosine kinase inhibitors (TKIs) are effective treatments for non-small cell lung cancers (NSCLCs) with epidermal growth factor receptor (EGFR) mutations. However, they do not lead to cures, and, on average, relapse occurs after one year of continuous treatment. In a subset of patients, a fundamental histological transformation from NSCLC to small cell lung cancer (SCLC) is observed in the resistant cancers, but the molecular changes associated with this transformation remain unknown. Analysis of a cohort of tumor samples and cell lines derived from resistant EGFR mutant patients with SCLC transformation revealed that RB is lost in 100% of these cases, but rarely in those that remain NSCLC. Global changes in gene expression, including increased neuroendocrine marker expression and absence of EGFR expression, are observed in cancers that transformed to SCLC. Consistent with their genetic and epigenetic similarities to classical SCLC, cell lines derived from resistant EGFR mutant SCLC biopsies are substantially more sensitive to ABT-263 treatment compared to those derived from resistant EGFR mutant NSCLCs. Together, these findings suggest that despite developing initially as EGFR mutant adenocarcinomas, this subset of resistant cancers ultimately take on many of the molecular and phenotypic characteristics of classical SCLC. The patient-derived cell line models MGH119, MGH121, MGH125, MGH126, MGH131-1, MGH131-2, MGH134 and MGH156 were developed on collagen coated plates in ACL4 medium and transferred to RPMI. MGH157 was developed initially in RPMI. The cell line MGH141 was derived using the feeder system with irradiated fibroblasts (5000 rad) from normal patient tissue. When a tumor cell majority was observed it was passaged off of the feeder layer and later transferred to RPMI medium for experiments. The development of a model was considered complete when it was independent of the feeder system, free of stromal cells, and determined to maintain known patient tumor mutations. MGH119-R was derived in vitro from the treatment naive model, MGH119, through in vitro exposure to gefitinib, escalating from 10nM to a final concentration of 1μM.
Project description:Tyrosine kinase inhibitors (TKIs) are effective treatments for non-small cell lung cancers (NSCLCs) with epidermal growth factor receptor (EGFR) mutations. However, they do not lead to cures, and, on average, relapse occurs typically occurs afterafter an average of one year of continuous treatment. In a subset of patients, aA fundamental histological transformation from NSCLC to small cell lung cancer (SCLC) is observed in a subset of the resistant cancers, but the molecular changes associated with this transformation remain unknown. Analysis of a cohort of tumor samples and cell lines derived from resistant EGFR mutant patients with SCLC transformation revealed that RB is lost in 100% of these SCLC transformed cases, but rarely in those that remain NSCLC. Global changes in gene expression, including increased neuroendocrine marker expression and absence of EGFR expression, are observed in resistant EGFR mutant cancers that transformed to SCLC. Consistent Further, with their similarities to classical SCLC at the genetic and gene expression levelincreased neuroendocrine marker and decreased EGFR expression as well as greater sensitivity to BCL2 family inhibition are observed in resistant SCLC transformed cancers compared to resistant NSCLCs. , cell lines derived from resistant EGFR mutant SCLC biopsies are substantially more sensitive to Bcl-2 family inhibition with ABT-263 compared to those derived from resistant EGFR mutant NSCLCs. Together, these findings suggest that despite developing initially as EGFR mutant adenocarcinomas, this subset of resistant cancers ultimately adopt many of the molecular and phenotypic characteristics of classical SCLC.
Project description:Human non-small-cell lung cancers (NSCLCs) harboring activating mutations in epidermal growth factor receptor (EGFR) frequently respond to EGFR tyrosine kinase inhibitors (TKIs), such as erlotinib and gefitinib. However, the responses are not durable, and the magnitude of tumor regression is variable, suggesting the existence of genetic modifiers of EGFR dependency in EGFR-mutant NSCLCs. Here, we applied a genome-wide CRISPR-Cas9 screening to identify genetic determinants of EGFR TKI sensitivity and uncovered both known and putative candidates. Specifically, we show that knockout of RIC8A, a guanine nucleotide exchange factor (GEF) essential for G-alpha protein activation, enhanced EGFR TKI-induced cell death and prevented acquired resistance. Mechanistically, we demonstrate that RIC8A is a potent positive regulator of the pro-survival YAP signaling pathway, activation of which rescued the EGFR TKI sensitizing phenotype resulting from RIC8A knockout. We also show that knockout of ARIH2, or other components in the Cullin-5 E3 ubiquitin ligase complex, conferred resistance to EGFR inhibition, in part by promoting nascent protein synthesis through METAP2. Together, these data uncover a spectrum of previously unidentified regulators of EGFR TKI sensitivity in EGFR-mutant NSCLC cells, providing insights into the heterogeneity of EGFR TKI treatment responses in EGFR-mutant NSCLCs.
Project description:Histological transformation from epidermal growth factor receptor (EGFR)-mutant non-small cell lung cancer (NSCLC) to small cell lung cancer (SCLC) is the major resistance mechanism of EGFR tyrosine kinase inhibitors (TKIs). In our analysis of 59 regions of interest from EGFR-mutant NSCLC or combined SCLC/NSCLC tumors, we compared the transcriptomic profiles before and after transformation.
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:Epidermal growth factor receptor (EGFR) harboring active mutations, Del19 and L858R, are most common oncogenic mutations in in non-small cell lung cancer (NSCLC) patients. The preferred treatment at first line is tyrosine kinase inhibitor (TKI) administration while the TKI-resistance usually develops because of acquiring the secondary EGFR T790M mutant. Protein-protein interactions (PPIs) constitute the signaling scaffold and thus aberrant PPIs ascribed to mutations often results in dysregulations of downstream signaling cascades. Affinity purification coupled mass spectrometry (AP-MS) was utilized to characterize the EGFR PPIs in four NSCLC cells which carry different EGFR subtypes representing as TKI-sensitive and -resistant models in this study. The EGFR interactomes of TKI-resistant NSCLC cells presented higher diversity of subcellular distribution as well as the hyperactive EGFR trafficking. Furthermore, gefitinib perturbation activated autophagy-mediated EGFR degradation in TKI-resistant NSCLC models and inhibiting autophagy process indeed reduced the TKI-resistance against gefitinib as cytotoxicity was significantly improved. Alternatively, gefitinib induced EGFR translocation toward cell periphery through Rab7 ubiquitination in TKI-sensitive models which may confer TKIs more chance to suppress EGFR activity. In brief, acquired T790M EGFR mutation rewired the EGFR inherent interactomes and thus guided EGFR moving toward distinct trafficking routes, EGFR recycling or autophagy-mediated degradation, in response to TKI insult in TKI-sensitive and -resistant NSCLC cells. These finding suggest that manipulation or combined autophagy inhibition may provide us a novel therapeutic strategy to manage TKI-resistance and tumor relapse in NSCLC.
Project description:This study identifies the oncogenic protein MUC1-C as a key driver of resistance to the EGFR tyrosine kinase inhibitor osimertinib in non-small cell lung cancers (NSCLCs).MUC1-C promotes resistance by activating STAT1 and type I/II interferon pathways, creating an inflammatory memory of the resistant phenotype. This memory is maintained via MUC1-C/STAT1 interaction at one enhancer region (pELS-1) and MUC1-C/JUN/PBAF at another (pELS-2) in the MUC1 gene. MUC1-C also mediates resistance to combination EGFR/MET inhibitors and a fourth-generation EGFR TKI (TQB3804). Importantly, targeting MUC1-C with an antibody-drug conjugate (M1C ADC) is effective both in vitro and in a patient-derived xenograft model, making MUC1-C a promising therapeutic target for TKI-refractory NSCLC.
Project description:Non-small cell lung cancers (NSCLCs) harboring activating EGFR mutants show dramatic responses to EGFR TKIs, such as erlotinib and geffitinib. However, nearly all patients show relapse within 1 year after initial treatment. We used microarrays to detail global gene expression changes in EGFR mutant cells vs. WT cells responding to erlotinib. 4 EGFR mutant and 4 WT NSCLC cells were treated with or without erlotinib for 24 hr, followed by RNA extraction and hybridization on Affymetrix microarrays.