Luteolin overcomes acquired resistance to osimertinib in non-small cell lung cancer cells by targeting the HGF-MET-Akt pathway.

Osimertinib, a third-generation epidermal growth factor receptor tyrosine kinase inhibitor (EGFR-TKI), has overcome the acquired resistance of first- and second-generation EGFR-TKIs due to the EGFR T790M mutation in non-small cell lung cancer (NSCLC). However, acquired resistance to osimertinib remains a significant clinical challenge. Luteolin, a natural flavonoid from traditional Chinese medicine, has exerted antitumor effects in various tumors. In this study, we investigated whether the natural flavonoid luteolin can enhance the antitumor effects of osimertinib in NSCLC cells. We established an acquired osimertinib-resistant cell line, H1975/OR, and evaluated the effects of luteolin and osimertinib alone and in combination on proliferation, migration, invasion, and apoptosis of H1975/OR cells. The potential mechanisms by which the combination of luteolin and osimertinib exert their effects were investigated by PCR, western blot, gene silencing, molecular docking, SPR and kinase activity analysis. The combination of luteolin and osimertinib inhibited the proliferation, migration, and invasion of H1975/OR cells and promoted apoptosis. We identified mesenchymal-epithelial transition factor (MET) amplification and overactivation as important resistance mechanisms of H1975/OR cells. The combination downregulated the gene and protein expression of MET and inhibited its protein phosphorylation, thereby blocking the activation of the downstream Akt pathway. Additionally, the mediated effects of MET on the synergistic effect of luteolin and osimertinib were confirmed by silencing of MET. Luteolin strongly bound with nonphosphorylated MET by occupying the active pocket of MET and inhibiting its activation. Notably, the combination also downregulated the expression of autocrine hepatocyte growth factor (HGF), the sole ligand of MET. In conclusion, luteolin can synergize with osimertinib to overcome MET amplification and overactivation-induced acquired resistance to osimertinib by suppressing the HGF-MET-Akt pathway, suggesting the clinical potential of combining luteolin with osimertinib in NSCLC patients with acquired resistance.

Feiyiliu Mixture sensitizes EGFRDel19/T790M/C797S mutant non-small cell lung cancer to osimertinib by attenuating the PRC1/Wnt/EGFR pathway.

Introduction: Osimertinib is a potent epidermal growth factor receptor tyrosine kinase inhibitor (EGFR-TKI) for the treatment of patients with EGFR-mutant non-small cell lung cancer (NSCLC). However, the emergence of acquired resistance due to the EGFR-Del19/T790M/C797S mutation limits the clinical application of osimertinib. Feiyiliu Mixture (FYLM), a clinical experience formula of Chinese medicine, was used to treat lung cancer with good clinical efficacy. In this study, we aimed to investigate the mechanism by which Feiyiliu Mixture delays osimertinib resistance in EGFR-mutant cell lines and EGFR-mutant cell tumor-bearing mice. Methods: The osimertinib-resistant cell models were established in mouse Lewis lung carcinoma (LLC) cells transfected with EGFR-Del19/T790M/C797S mutant lentivirus. In cell experiments, after 48 h of treatment with Feiyiliu Mixture-containing serum, MTT assay was used to detect the relative cell viability, and western blotting was used to detect EGFR protein phosphorylation expression. In animal experiments, C57BL/6J mice were subcutaneously injected with Lewis lung carcinoma cells stably expressing EGFR-Del19/T790M/C797S mutations to construct a xenograft model. After 2 weeks of Feiyiliu Mixture and/or osimertinib treatment, the expression of proliferation-related, apoptosis-related and PRC1/Wnt/EGFR pathway markers was detected by real-time qPCR, western blotting and immunohistochemistry. Results: The results showed that when combined with osimertinib, Feiyiliu Mixture synergistically reduces proliferation and increases apoptosis to improve drug resistance. In vitro, Feiyiliu Mixture-containing serum reduced the EGFR phosphorylation. In vivo, Feiyiliu Mixture downregulated the expression of cyclin B1 and Bcl-2 while upregulating the level of cleaved Caspase-3 protein, indicating that Feiyiliu Mixture promotes apoptosis. Furthermore, Feiyiliu Mixture reduced the expression of p-EGFR, p-Akt, PRC1 and Wnt pathway-related proteins such as ß-catenin, c-Myc and c-Jun. Conclusion: The present study identified that Feiyiliu Mixture inhibited PRC1/Wnt/EGFR pathway activation, reduced proliferation, and promoted apoptosis, thereby increasing the sensitivity of EGFR-mutant non-small cell lung cancer to osimertinib. Our study provided a new idea for Chinese medicine to play a role in enhancing efficacy and reducing toxicity in the treatment of non-small cell lung cancer.

Role of lung and gut microbiota on lung cancer pathogenesis.

BACKGROUND: Lung cancer is the leading cause of cancer-related deaths worldwide (Ferlay et al., Int J Cancer 136:E359-386, 2015). In addition, lung cancer is associated with the highest mortality among all cancer types (Wu et al., Exp Ther Med 16:3004-3010, 2018). Previous studies report that microbiota play an important role in lung cancer. Notably, changes in lung and gut microbiota, are associated with progression of lung cancer. Several studies report that lung and gut microbiome promote lung cancer initiation and development by modulating metabolic pathways, inhibiting the function of immune cells, and producing pro-inflammatory factors. In addition, some factors such as microbiota dysbiosis, affect production of bacteriotoxins, genotoxicity and virulence effect, therefore, they play a key role in cancer progression. These findings imply that lung and gut microbiome are potential markers and targets for lung cancer. However, the role of microbiota in development and progression of lung cancer has not been fully explored. PURPOSE: The aim of this study was to systemically review recent research findings on relationship of lung and gut microbiota with lung cancer. In addition, we explored gut-lung axis and potential mechanisms of lung and gut microbiota in modulating lung cancer progression. CONCLUSION: Pulmonary and intestinal flora influence the occurrence, development, treatment and prognosis of lung cancer, and will provide novel strategies for prevention, diagnosis, and treatment of lung cancer.

Therapeutic strategies for acute intermittent porphyria.

Acute intermittent porphyria (AIP) is an autosomal dominant disease caused by mutations in porphobilinogen deaminase (PBGD), the third enzyme of the heme synthesis pathway. Symptoms of AIP usually manifest as intermittent acute attacks with occasional neuropsychiatric crises. The management of AIP includes treatment of acute attacks, prevention of attacks, long-term monitoring and treatment of chronic complications. Intravenous injection of heme is the most effective method of treating acute attacks. Carbohydrate loading is used when heme is unavailable or in the event of mild attacks. Symptomatic treatment is also needed during attacks. Prevention of attacks includes eliminating precipitating factors, heme prophylaxis and liver transplantation. New treatment options include givosiran (siRNA) to down-regulate ALA synthase-1 (ALAS1) and the messenger RNA of PBGD (PBGD mRNA) delivered to the liver cells of patients with AIP. Long-term monitoring of chronic complications includes regular liver-kidney function and hepatocellular carcinoma (HCC) screening.

Identification and analysis of differential miRNAs in PK-15 cells after foot-and-mouth disease virus infection.

The alterations of MicroRNAs(miRNAs) in host cell after foot-and-mouth disease virus (FMDV) infection is still obscure. To increase our understanding of the pathogenesis of FMDV at the post-transcriptional regulation level, Solexa high-throu MicroRNAs (miRNAs) play an important role both in the post-transcriptional regulation of gene expression and host-virus interactions. Despite investigations of miRNA expression ghput sequencing and bioinformatic tools were used to identify differentially expressed miRNAs and analyze their functions during FMDV infection of PK-15 cells. Results indicated that 9,165,674 and 9,230,378 clean reads were obtained, with 172 known and 72 novel miRNAs differently expressed in infected and uninfected groups respectively. Some of differently expressed miRNAs were validated using stem-loop real-time quantitative RT-PCR. The GO annotation and KEGG pathway analysis for target genes revealed that differently expressed miRNAs were involved in immune response and cell death pathways.