Project description:The clinical significance of gene fusions detected by DNA-based next generation sequencing remains unclear as resistance mechanisms to EGFR tyrosine kinase inhibitors (TKIs) in EGFR mutant non-small cell lung cancer (NSCLC). Through comprehensive evaluation of potential drug resistance-imparting fusion oncogenes in EGFR mutant lung cancers, we selected candidate samples to be further validated by confirmatory assay. Here, we performed RNA sequencing as an unbiased genome-wide method to identify novel oncogenic fusions. In 11 samples from 10 patients, 3 different fusion callers consistently detected only the DLG1-BRAF fusion in sample 6. None of other putative fusions detected by DNA-based hybrid capture sequencing were validated.We concluded that only a subset of putative fusion was validated by RNA-seq.
Project description:Lung cancer is the leading cause of cancer related death worldwide, mainly due to the late stage of disease at the time of diagnosis. Non-invasive biomarkers are needed to supplement existing screening methods to enable earlier detection and increased patient survival. This is critical to EGFR-driven lung adenocarcinoma as it commonly occurs in individuals who have never smoked and do not qualify for current screening protocols. Methods: In this study, we performed mass spectrometry analysis of the secretome of cultured lung cells representing different stages of mutant EGFR driven transformation, from normal to fully malignant. Identified secreted proteins specific to the malignant state were validated using orthogonal methods and their clinical activity assessed in lung adenocarcinoma patient cohorts. Results: We quantified 1020 secreted proteins, which were compared for differential expression between stages of transformation. We validated differentially expressed proteins at the transcriptional level in clinical tumor specimens, association with patient survival, and absolute concentration to yield three biomarker candidates: MDK, GDF15, and SPINT2. These candidates were validated using ELISA and increased levels were associated with poor patient survival specifically in EGFR mutant lung adenocarcinoma patients. Conclusions: Our study provides insight into changes in secreted proteins during EGFR driven lung adenocarcinoma transformation that may play a role in the processes that promote tumor progression. The specific candidates identified can harnessed for biomarker use to identify high risk individuals for early detection screening programs and disease management for this molecular subgroup of lung adenocarcinoma patients.
Project description:Oncogene-driven lung cancers such as those with activating mutations in the epidermal growth factor receptor (EGFR) often harbor additional co-occurring genetic alterations. The significance of most alterations co-occurring with mutant EGFR remains unclear. We report the impact of loss of the mRNA splicing factor RBM10 in human EGFR mutant lung cancer. RBM10 loss decreased EGFR inhibitor efficacy in patient-derived EGFR mutant tumor models. RBM10 regulated mRNA splicing of the mitochondrial apoptotic regulator Bcl-x. Genetic inactivation of RBM10 diminished EGFR inhibitor-mediated apoptosis by altering Bcl-x splicing, decreasing Bcl-xS (pro-apoptotic) and increasing Bcl-xL (anti-apoptotic) levels. Co-inhibition of Bcl-xL and mutant EGFR overcomes resistance induced by RBM10 loss. RBM10 loss was a biomarker of poor response to EGFR inhibitor treatment in clinical samples. Inactivation of the splicing factor RBM10 is a key co-occurring genetic alteration in EGFR mutant tumors that limits EGFR inhibitor efficacy and a potential biomarker of Bcl-xL inhibitor response.
Project description:Metastatic relapse from treatment failure has been a formidable challenge to finding a cure for EGFR-mutant lung cancer. Metastasis to the brain is a severe complication for 45% of patients with EGFR-mutant lung cancer that drastically reduces their quality of life and survival. Here, we demonstrate that genetic inhibition of S100A9, ALDH1A1, RAR, or pharmacological inhibition of the RA pathway using pan-RAR inhibitors significantly reduces brain relapse from osimertinib-refractory cancer cells. Our study has therefore revealed a novel S100A9-ALDH1A1-RA signaling axis in the EGFR-mutant lung cancer cells that drives osimertinib-refractory metastatic brain relapse and identified a potential vulnerability in lung cancer cells that can be therapeutically targeted to prolong progression-free survival in EGFR-mutant lung cancer patients.
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:In this study, we established 2 EGFR-mutant SCLC cell lines from lung adenocarcinoma patients after failed EGFR-TKI treatment. These 2 EGFR-mutant SCLC cell lines displayed 2 different phenotypes: suspensive and adherent. We used microarrays to identify the global gene alterations and molecular basis of EGFR-mutant SCLC cell lines.
Project description:Introduction: Overcoming of acquired resistance to EGFR-tyrosine kinase inhibitors (EGFR-TKIs) is an intractable obstacle for many clinical oncologists. The mechanisms of resistance to EGFR-TKIs are very complex. Long non-coding RNAs (lncRNAs) may play an important role in cancer development and metastasis. However, the biological process between lncRNAs and drug resistance to EGFR mutated lung cancer largely unknown. Methods: Osimertinib and afatinib-resistant EGFR-mutated lung cancer cells were established using by a stepwise method. Microarray analysis of non-coding and coding RNAs was performed using parental and resistant EGFR-mutant NSCLC cells. Results: Microarray analysis was evaluated by bioinformatics analysis through medical-industrial collaboration. CRNDE and DGCR5 lncRNAs were highly expressed in EGFR-TKIs-resistant cells. CRNDE binds to eIF4A3 protein, down-regulates eIF4A3 and MUC1 expression, and down-regulates p-EGFR expression. CRNDE inhibition activated the eIF4A3/MUC1/EGFR signaling pathway and apoptotic activity and restored sensitivity to EGFR-TKIs. Conclusions: We identified lncRNA CRNDE associated with resistance to EGFR-TKIs in EGFR-mutant NSCLC cells. CRNDE may be a novel therapeutic target for EGFR mutant NSCLC patients.
Project description:Histologic transformation to small cell lung cancer (SCLC) is an increasingly common resistance mechanism to EGFR tyrosine kinase inhibitors in EGFR mutant lung adenocarcinoma (LUAD) that is underdiagnosed in clinical practice due to the requirement for tissue biopsy. Early and accurate detection of transformed (t)SCLC has important prognostic and therapeutic implications. To address this unmet need, we first comprehensively profiled the epigenomes of metastatic lung tumors finding widespread epigenomic reprogramming during histologic transformation from LUAD to SCLC. We then utilized a novel approach for epigenomic profiling of cell-free DNA, which discriminated patients with EGFR mutant tSCLC from patients with EGFR mutant LUAD with greater than 90% accuracy. This first demonstration of the ability to accurately, and non-invasively, detect small cell transformation in patients with EGFR mutant LUAD through epigenomic cfDNA profiling is a critical step towards a new paradigm of diagnostic and therapeutic precision for patients with advanced lung cancer.
Project description:Lung cancers bearing oncogenically-mutated EGFR represent a significant fraction of lung adenocarcinomas (LUADs) for which EGFR-targeting tyrosine kinase inhibitors (TKIs) provide a highly effective therapeutic approach. However, these lung cancers eventually acquire resistance and undergo progression within a characteristically broad treatment duration range. Our previous study of EGFR mutant lung cancer biopsies highlighted the positive association of a TKI-induced interferon g transcriptional response with increased time to treatment progression. Herein, we demonstrate that two additional gene expression signatures predictive of immunotherapy response also associate with longer duration of TKI treatment response, despite lack of efficacy of immunotherapy in EGFR mutant lung cancers. To test the hypothesis that host immunity contributes to the TKI response, we developed novel genetically-engineered mouse models of EGFR mutant lung cancer bearing exon 19 deletions (del19) or the L860R missense mutation. Both oncogenic EGFR mouse models developed multifocal LUADs from which transplantable cancer cell lines sensitive to the EGFR-specific TKIs, gefitinib and osimertinib, were derived. When propagated orthotopically in the left lungs of syngeneic C57BL/6 mice, deep and durable shrinkage of the cell line-derived tumors was observed in response to daily treatment with osimertinib. By contrast, orthotopic tumors propagated in immune deficient nu/nu mice exhibited modest tumor shrinkage followed by rapid progression on continuous osimertinib treatment. Osimertinib treatment significantly increased intratumoral CD3+ T cell content relative to diluent treatment. The findings provide strong evidence supporting the requirement for adaptive immunity in the durable therapeutic control of EGFR mutant lung cancer.
Project description:Human EGFR-mutant lung cancer cells lines were investigated for their dynamic transcriptional response upon treatment with EGFR-inhibitor osimertinib in a time-series experiment