Abstract 1101: Intercellular transfer of exosomal wild type EGFR triggers osimertinib resistance in non-small cell lung cancer

Author(s):  
Shaocong Wu ◽  
Min Luo ◽  
Kenneth K. To ◽  
Jianye Zhang ◽  
Chaoyue Su ◽  
...  
2021 ◽  
Vol 20 (1) ◽  
Author(s):  
Shaocong Wu ◽  
Min Luo ◽  
Kenneth K. W. To ◽  
Jianye Zhang ◽  
Chaoyue Su ◽  
...  

Abstract Background Epidermal growth factor receptor (EGFR)-mutated lung cancer constitutes a major subgroup of non-small cell lung cancer (NSCLC) and osimertinib is administrated as first-line treatment. However, most patients with osimertinib treatment eventually relapse within one year. The underlying mechanisms of osimertinib resistance remain largely unexplored. Methods Exosomes isolation was performed by differential centrifugation. Co-culture assays were conducted to explore the alteration of drug sensitivity by cell viability and apoptosis assays. Immunofluorescence and flow cytometry were performed to visualize the formation or absorption of exosomes. Exosomes secretion was measured by Nanoparticle Tracking Analysis or ELISA. The xenograft tumor model in mice was established to evaluate the effect of exosomes on osimertinib sensitivity in vivo. Results Intercellular transfer of exosomal wild type EGFR protein confers osimertinib resistance to EGFR-mutated sensitive cancer cells in vitro and in vivo. Co-culture of EGFR-mutated sensitive cells and EGFR-nonmutated resistant cells promoted osimertinib resistance phenotype in EGFR-mutated cancer cells, while depletion of exosomes from conditioned medium or blockade of exosomal EGFR by neutralizing antibody alleviated this phenotype. Mechanistically, osimertinib promoted the release of exosomes by upregulated a Rab GTPase (RAB17). Knockdown of RAB17 resulted in the decrease of exosomes secretion. Moreover, exosomes could be internalized by EGFR-mutated cancer cells via Clathrin-dependent endocytosis and then the encapsulated exosomal wild type EGFR protein activated downstream PI3K/AKT and MAPK signaling pathways and triggered osimertinib resistance. Conclusions Intercellular transfer of exosomal wild type EGFR promotes osimertinib resistance in NSCLC, which may represent a novel resistant mechanism of osimertinib and provide a proof of concept for targeting exosomes to prevent and reverse the osimertinib resistance.


Haigan ◽  
2012 ◽  
Vol 52 (3) ◽  
pp. 315-319
Author(s):  
Masami Morimoto ◽  
Naoki Hino ◽  
Hisashi Matsuoka ◽  
Takanori Miyoshi ◽  
Masaru Tsuyuguchi

2021 ◽  
Vol 39 (15_suppl) ◽  
pp. e21064-e21064
Author(s):  
Shencun Fang ◽  
Wanwan Cheng ◽  
Yingming Zhang ◽  
Haitao Zhang ◽  
Si Li ◽  
...  

e21064 Background: Pulmonary lymphangitic carcinomatosis (PLC) occurs in 6%-8% of intrathoracic metastases among malignant tumor. The median survival was only 2.0 months from time of pulmonary symptoms to death in cases during 2000-2018, which is a poor prognosis. Effective interventions were needed besides standard chemotherapy and symptomatic support. Anlotinib showed a critical effect on lymphangiogenesis, and lymphatic metastasis in mouse models of lung adenocarcinoma, it might be a therapeutic option for tumor lymphatic metastasis. In this study, we retrospectively analyzed the efficacy and safety of anlotinib for PLC in patients with Non-small Cell Lung Cancer (NSCLC). Methods: We retrospectively investigated NSCLC patients with PLC at our hospital between May 2018 and November 2020, who received anlotinib monotherapy or combined therapy for PLC. Data were analyzed for progression-free survival (PFS), overall survival (OS), objective response rate(ORR), disease control rate(DCR) and adverse events (AE). The impact of clinical and genomic factors on PFS and OS were also assessed. Results: A total of 14 patients were enrolled with a median age of 64 years. 10(71.4%) were male, 4(28.6%) has smoking history, 10(71.4%) of patients had a performance status of 2-3. 9, 3, 2 patients had TP53 mutation, EGFR mutation, ALK fusion respectively. 9(64.3%) patients received anlotinib monotherapy. Of 14 patients, 8 achieved partial response (PR), 5 presented stable disease (SD), 1 had progressed disease. The ORR and DCR were 57.1% and 92.9% respectively. The median PFS was 3.1 months (95% CI: 2.0-4.2), the median OS for 1, 2, ≥3 line were 13 months, 7.2 months, 5.2 months, respectively. Median PFS and OS (≥3 line) were significantly longer for patients with TP53-mutant tumors compared with those with TP53–wild-type tumors (median PFS: 7 vs. 1.1 months, median OS (≥3 line): 6.8 vs. 1.9 months). No difference of PFS and OS (≥3 line) was found between EGFR or ALK alteration and the corresponding wild type patients. The most frequently reported AEs were high blood pressure (11, 78.6%), hand foot syndrome (6, 42.9%), diarrhea (5, 35.7%), fatigue (4, 28.6%), hoarseness (3, 21.4%), proteinuria (2, 14.3%) and stomatitis (2, 14.3%). Conclusions: Anlotinib presented favorable efficacy in patients with pulmonary lymphangitic carcinomatosis and conferred considerable survival benefit compared with previous studies, especially in patients harboring TP53 mutations. The AEs were manageable. These indicated that anlotinib can be a promising therapeutic treatment of PLC. More clinical data is needed to validate this finding.


2020 ◽  
Vol 21 (9) ◽  
pp. 3392
Author(s):  
Peizhong Kong ◽  
K.N. Yu ◽  
Miaomiao Yang ◽  
Waleed Abdelbagi Almahi ◽  
Lili Nie ◽  
...  

Micheliolide (MCL) has shown promising anti-inflammatory and anti-tumor efficacy. However, whether and how MCL enhances the sensitivity of non-small-cell lung cancer (NSCLC) to radiotherapy are still unknown. In the present paper, we found that MCL exerted a tumor cell killing effect on NSCLC cells in a dose-dependent manner, and MCL strongly sensitized p53-deficient NSCLC cells, but not the cells with wild-type p53 to irradiation (IR). Meanwhile, MCL markedly inhibited the expression of hypoxia-inducible factor-1α (HIF-1α) after IR and hypoxic exposure in H1299 and Calu-1 cells rather than in H460 cells. Consistently, radiation- or hypoxia-induced expression of vascular endothelial growth factor (VEGF) was also significantly inhibited by MCL in H1299 and Calu-1 cells, but not in H460 cells. Therefore, inhibition of the HIF-1α pathway might, at least in part, contribute to the radiosensitizing effect of MCL. Further study showed that MCL could accelerate the degradation of HIF-1α through the ubiquitin-proteosome system. In addition, the transfection of wild-type p53 into p53-null cells (H1299) attenuated the effect of MCL on inhibiting HIF-1α expression. These results suggest MCL effectively sensitizes p53-deficient NSCLC cells to IR in a manner of inhibiting the HIF-1α pathway via promoting HIF-1α degradation, and p53 played a negative role in MCL-induced HIF-1α degradation.


2020 ◽  
Vol 146 (7) ◽  
pp. 1737-1749
Author(s):  
Amin Li ◽  
Weiya Cao ◽  
Xueke Liu ◽  
Yinci Zhang ◽  
Yongfang Ma ◽  
...  

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