Project description:Epidermal growth factor receptor (EGFR) mutations occur in about 50% of lung adenocarcinomas in Asia and about 15% in the US. EGFR mutation-specific inhibitors have been developed and made significant contributions to controlling EGFR mutated non-small cell lung cancer. However, resistance frequently develops within 1 to 2 years due to acquired mutations. No effective approaches that target mutant EGFR have been developed to treat relapse following tyrosine kinase inhibitor (TKI) treatment. Vaccination against mutant EGFR is one area of active exploration. In this study, we identified immunogenic epitopes for the common EGFR mutations in humans and formulated a multi-peptide vaccine (Emut Vax) targeting the EGFR L858R, T790M, and Del19 mutations. The efficacy of the Emut Vax was evaluated in both syngeneic and genetic engineered EGFR mutation-driven murine lung tumor models with prophylactic settings, where the vaccinations were given before the onset of the tumor induction. The multi-peptide Emut Vax effectively prevented the onset of EGFR mutation-driven lung tumorigenesis in both syngeneic and genetically engineered mouse models (GEMMs). Flow cytometry and single-cell RNA sequencing were conducted to investigate the impact of Emut Vax on immune modulation. Emut Vax significantly enhanced Th1 responses in the tumor microenvironment and decreased suppressive Tregs to enhance anti-tumor efficacy. Our results show that multi-peptide Emut Vax is effective in preventing common EGFR mutation-driven lung tumorigenesis, and the vaccine elicits broad immune responses that are not limited to anti-tumor Th1 response.
Project description:The purpose of this research is to study the cellular origins of EGFR-mutant lung cancers and their responses to therapies. We discovered that activation of EGFR T790M/L858R mutation in lung epithelial cells can drive lung cancers with alveolar or bronchiolar features, which can be originated from alveolar type 2 (AT2) cells or bronchioalveolar stem cells (BASCs), but not basal cells or club cells of the trachea. Crucially, the tumoroids with different cell-of-origins or epigenetic states had distinct drug vulnerabilities.
Project description:Cancer genome sequencing has uncovered substantial complexity in the mutational landscape of tumors. Given this complexity, experimental approaches are necessary to establish the impact of combinations of genetic alterations on tumor biology and to uncover genotype-dependent effects on drug sensitivity. In lung adenocarcinoma, EGFR mutations co-occur with many putative tumor suppressor gene alterations, however the extent to which these alterations contribute to tumor growth and their response to therapy in vivo has not been explored experimentally. By integrating a novel mouse model of oncogenic EGFR-driven Trp53-deficient lung adenocarcinoma with multiplexed CRISPR–Cas9-mediated genome editing and tumor barcode sequencing, we quantified the effects of inactivation of ten putative tumor suppressor genes. Inactivation of Apc, Rb1, or Rbm10 most strongly promoted tumor growth. Unexpectedly, inactivation of Lkb1 or Setd2 – which were the strongest drivers of tumor growth in an oncogenic Kras-driven model – reduced EGFR-driven tumors growth. These results were consistent with the relative frequency of these tumor suppressor gene alterations in human EGFR and KRAS-driven lung adenocarcinomas. Furthermore, Keap1 inactivation reduced the sensitivity of tumors to osimertinib in the EGFRL858R;p53flox/flox model. Importantly, in human EGFR/TP53 mutant lung adenocarcinomas, mutations in the KEAP1 pathway correlated with decreased time on tyrosine kinase inhibitor treatment. Our study highlights how genetic alterations can have dramatically different biological consequences depending on the oncogenic context and that the fitness landscape can shift upon drug treatment.
Project description:Approximately 15% of lung cancer cases are not associated with smoking and show molecular and clinical characteristics distinct from those in smokers. Epidermal growth factor receptor (EGFR) gene mutations, which are correlated with sensitivity to EGFR-tyrosine kinase inhibitors (EGFR-TKIs), are more frequent in never-smoker lung cancers. In this study, microRNA (miRNA) expression profiling of 28 never-smoker lung cancer cases identified aberrantly expressed miRNAs, which were much fewer than in lung cancers of smokers and included miRNAs previously identified (e.g., upregulated miR-21) and unidentified (e.g., downregulated miR-138) in those smoker cases. The changes in expression of some of these miRNAs were more remarkable in cases with EGFR mutations than in those without: the most upregulated miRNA, miR-21, was more abundant in cancers with EGFR mutation. A significant correlation between phosphorylated-EGFR (p-EGFR) and miR-21 levels in lung carcinoma cell lines and the suppression of miR-21 by an EGFR-TKI, AG1478, suggested that the EGFR signaling pathway positively regulated miR-21 expression. In a never-smoker-derived lung adenocarcinoma cell line H3255 with mutant EGFR and high levels of p-EGFR and miR-21, antisense inhibition of miR-21 enhanced AG1478-induced apoptosis. In a never-smoker-derived adenocarcinoma cell line H441 with wild-type EGFR, the antisense miR-21 not only showed the additive effect with AG1478 but also induced apoptosis by itself. These results suggest that aberrantly increased expression of miR-21, which is further enhanced by the activated EGFR signaling pathway, plays a critical role in lung carcinogenesis in never-smokers and is a potential therapeutic target in both EGFR mutant and wild-type cases. Twenty-eight pairs of lung cancer tissues and corresponding noncancerous lung tissues were obtained from never-smokers who had undergone surgical resection from 2000 to 2004 at the University of Maryland Medical Center (n=15), Mayo Clinic (n=7) in United States and Hamamatsu University School of Medicine (n=6) in Japan.
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:Acquired resistance represents a bottleneck for effective molecular targeted therapy in lung cancer. Metabolic adaptation is a distinct hallmark of human lung cancer that might contribute to acquired resistance. In this study, we discovered a novel mechanism of acquired resistance to EGFR tyrosine kinase inhibitors (TKI) mediated by IGF2BP3-dependent cross-talk between epigenetic modifications and metabolic reprogramming through the IGF2BP3–COX6B2 axis. IGF2BP3 was upregulated in patients with TKI-resistant non–small cell lung cancer, and high IGF2BP3 expression correlated with reduced overall survival. Upregulated expression of the RNA binding protein IGF2BP3 in lung cancer cells reduced sensitivity to TKI treatment and exacerbated the development of drug resistance via promoting oxidative phosphorylation (OXPHOS). COX6B2 mRNA bound IGF2BP3, and COX6B2 was required for increased OXPHOS and acquired EGFR-TKI resistance mediated by IGF2BP3. Mechanistically, IGF2BP3 bound to the untranslated region of COX6B2 in an m6A-dependent manner to increase COX6B2 mRNA stability. Moreover, the IGF2BP3–COX6B2 axis regulated nicotinamide metabolism, which can alter OXPHOS and promote EGFR-TKI acquired resistance. Inhibition of OXPHOS with IACS-010759, a small-molecule inhibitor, resulted in strong growth suppression in vitro and in vivo in a gefitinib-resistant patient-derived xenograft model. Collectively, these findings suggest that metabolic reprogramming by the IGF2BP3–COX6B2 axis plays a critical role in TKI resistance and confers a targetable metabolic vulnerability to overcome acquired resistance to EGFR-TKIs in lung cancer.
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: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:Our study identified for PHF12 an oncogenic role in lung cancer proliferation for the first time. PHF12 transcriptionally regulate HDAC1 and activate EGFR/AKT signaling pathway in NSCLC progression. PHF12 may serve as an important target in lung cancer therapy.