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INTRODUCTION: EGFR-mutated NSCLC is characterized by an immunosuppressive microenvironment that confers limited clinical effectiveness to anti-PD-1 or PD-L1 antibodies. Despite the discouraging outcomes of immunotherapy, novel immune checkpoints are constantly emerging, among which the specific vulnerability for therapeutic intervention in the context of EGFR-mutated NSCLC remains unresolved. METHODS: Data sets of patient- and cell line-levels were used for screening and mutual validation of association between EGFR mutation and a panel of immune checkpoint-related genes. Regulatory mechanism was elucidated through in vitro manipulation of EGFR signaling pathway and evaluated by immunoblot analysis, quantitative polymerase chain reaction, flow cytometry, immunofluorescence staining, and chromatin immunoprecipitation. In vivo investigation of different therapeutic strategies were conducted using both immunocompetent and immunodeficient mouse models. RESULTS: Among all screened immune checkpoints, CD47 emerged as the candidate most relevant to EGFR activation. Mechanistically, EGFR mutation constitutively activated downstream ERK and AKT pathways to respectively up-regulate the transcriptional factors c-Myc and NF-κB, both of which structurally bound to the promotor region of CD47 and actively transcribed this "don't eat me" signal. Impaired macrophage phagocytosis was observed on introduction of EGFR-sensitizing mutations in NSCLC cell line models, whereas CD47 blockade restored the phagocytic capacity and augmented tumor cell killing in both in vitro and in vivo models. Remarkably, the combination of anti-CD47 antibody with EGFR tyrosine kinase inhibitor revealed an additive antitumor activity compared with monotherapy of either antitumor agent in both immunocompetent and adaptive immunity-deficient mouse models. CONCLUSIONS: EGFR-sensitizing mutation facilitates NSCLC's escape from innate immune attack through up-regulating CD47. Combination therapy incorporating CD47 blockade holds substantial promise for clinical translation in developing more effective therapeutic approaches against EGFR-mutant NSCLC.
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Chiral organic-inorganic perovskites (COIPs) have recently attracted increasing interest due to their unique inherent chirality and potential applications in next-generation optoelectronic and spintronic devices. However, COIP ferroelectrics are very sparse. In this work, for the first time, we present the nickel-nitrite ABX3 COIP ferroelectrics, [(R and S)-N-fluoromethyl-3-quinuclidinol]Ni(NO2)3 ([(R and S)-FMQ]Ni(NO2)3), where the X-site is the rarely seen NO2- bridging ligand. [(R and S)-FMQ]Ni(NO2)3 display mirror-relationship in the crystal structure and vibrational circular dichroism signal. It is emphasized that [(R and S)-FMQ]Ni(NO2)3 show splendid ferroelectricity with both an extremely high phase-transition point of 405 K and a spontaneous polarization of 12 µC/cm2. To our knowledge, [(R and S)-FMQ]Ni(NO2)3 are the first examples of nickel-nitrite based COIP ferroelectrics. This finding expands the COIP family and throws light on exploration of high-performance COIP ferroelectrics.