Orthotopic model of lung cancer: isolation of bone micro-metastases after tumor escape from Osimertinib treatment.

BACKGROUND: Osimertinib is a third generation tyrosine kinase inhibitor (TKI) that targets the epidermal growth factor receptor (EGFR) in lung cancer. However, although this molecule is not subject to some of the resistance mechanisms observed in response to first generation TKIs, ultimately, patients relapse because of unknown resistance mechanisms. New relevant non-small cell lung cancer (NSCLC) mice models are therefore required to allow the analysis of these resistance mechanisms and to evaluate the efficacy of new therapeutic strategies. METHODS: Briefly, PC-9 cells, previously modified for luciferase expression, were injected into the tail vein of mice. Tumor implantation and longitudinal growth, almost exclusively localized in the lung, were evaluated by bioluminescence. Once established, the tumor was treated with osimertinib until tumor escape and development of bone metastases. RESULTS: Micro-metastases were detected by bioluminescence and collected for further analysis. CONCLUSION: We describe an orthotopic model of NSCLC protocol that led to lung primary tumor nesting and, after osimertinib treatment, by metastases dissemination, and that allow the isolation of these small osimertinib-resistant micro-metastases. This model provides new biological tools to study tumor progression from the establishment of a lung tumor to the generation of drug-resistant micro-metastases, mimicking the natural course of the disease in human NSCLC patients.

Design, synthesis and biological evaluation of novel heptamethine cyanine dye-erlotinib conjugates as antitumor agents.

Epidermal growth factor receptor tyrosine kinase (EGFR-TK) has been proved as a target for the treatment of non-small cell lung cancer (NSCLC) with specific gene mutations. However, EGFR-TK inhibitors (EGFR-TKIs) need to enter cancer cells and then competitively interact with the active site of tyrosine kinase receptors to suppress the downstream signaling pathway to inhibit tumor proliferation. In this study, in order to improve the tumor cell targeting ability of EGFR-TKI, EGFR-TKI erlotinib was conjugated with the cancer cell-targeting heptamethine cyanine dyes to form seventeen novel erlotinib-dye conjugates. The efficiency of tumor targeting properties of conjugates against cancer cell growth and EGFR-TK inhibition was evaluated in vitro. The result revealed that most erlotinib-dye conjugates exhibited stronger inhibitory effect on A549, H460, H1299 and MDA-MB-231 cell lines than the parent drug erlotinib. Meanwhile, representative compounds exhibited weak cytotoxicity on human normal mammary epithelial MCF-10A cells. Moreover, the conjugate CE17 also showed ~14-fold higher EGFR-TK inhibition activity (IC50 = 0.124 µM) than erlotinib (IC50 = 5.182 µM) in A549 cell line. Finally, molecular docking analysis verified that the erlotinib moiety of compound CE17 could form hydrogen bond with Met-769 and occupy active cavity of EGFR-TK. Therefore, we believed the integration strategy between heptamethine cyanine dyes and EGFR-TKI will contribute to enhancing the therapeutic effect of EGFR-TKI for NSCLC treatment.

Synthesis and evaluation of 2,9-disubstituted 8-phenylthio/phenylsulfinyl-9H-purine as new EGFR inhibitors.

In present study, we described the synthesis and biological evaluation of a new class of EGFR inhibitors containing 2,9-disubstituted 8-phenylthio/phenylsulfinyl-9H-purine scaffold. Thirty-one compounds were synthesized. Among them, compound C9 displayed the IC50 of 29.4 nM against HCC827 cell line and 1.9 nM against EGFRL858R. Compound C12 showed moderate inhibitory activity against EGFRL858R/T790M/C797S (IC50 = 114 nM). Western bolt assay suggested that compound C9 significantly inhibited EGFR phosphorylation. In vivo test, compound C9 remarkably exhibited inhibitory effect on tumor growth at 5.0 mg/kg by oral administration in established nude mouse HCC827 xenograft model. These results indicate that the 2,9-disubstituted 8-phenylsulfinyl/phenylsulfinyl-9H-purine derivatives can act as potent EGFR(L858R) inhibitors and effective anticancer agents. Additionally, optimization of compound C12 may result in discovering the fourth-generation EGFR-TKIs.

Combination of 4-anilinoquinazoline, arylurea and tertiary amine moiety to discover novel anticancer agents.

In present study, 4-anilinoquinazolines scaffold, arylurea and tertiary amine moiety were combined to design, synthesize gefitinib analogs and discover novel anticancer agents. A series of 4-anilinoquinazoline derivatives (1, 2, 3 and 4) bearing arylurea and tertiary amine moiety at its 6-position were synthesized. Their antiproliferative activities in vitro were evaluated via MTT assay against A431 cell and A549 cell. The SAR of the title compounds was discussed. The compounds 2d, 2i and 2j with potent antiproliferative activities were evaluated their inhibitory activity against EGFR-TK. Compound 2j displayed potent inhibitory activity against EGFR-TK. In addition, compound 2j, at 50 mg/kg, can completely inhibit cancer growth in established nude mouse A549 xenograft model in vivo. These results suggest that the 4-anilinoquinazoline derivatives bearing diarylurea and tertiary amino moiety at its 6-position can serve as anticancer agents and EGFR inhibitors.

Modification of osimertinib to discover new potent EGFRC797S-TK inhibitors.

The EGFRC797S mutation is a dominant mechanism of acquired resistance after the treatment of non-small cell lung cancer (NSCLC) with osimertinib in clinic. To date, there is no inhibitor approved to overcome the resistance caused by osimertinib. In this study, a series of compounds with phenylamino-pyrimidine scaffold deriving from osimertinib were designed, synthesized and evaluated as fourth-generation EGFRC797S-TK inhibitors. Consequently, compound Os30 exhibited potent inhibitory activities against both EGFRDel19/T790M/C797S TK and EGFRL858R/T790M/C797S TK with IC50 values of 18 nM and 113 nM, respectively. Moreover, Os30 can powerfully inhibit the proliferation of KC-0116 (BaF3-EGFRDel19/T790M/C797S) and KC-0122 (BaF3-EGFRL858R/T790M/C797S) cells. In addition, Os30 can suppress EGFR phosphorylation in a concentration-dependent manner in KC-0116 cells, arrest KC-0116 cells at G1 phase and induce the apoptosis of KC-0116 cells. More importantly, Os30 showed potent antitumor efficacy in the KC-0116 cells xenograft nude mice tumor model with the tumor growth inhibitory rate of 77.6% at a dosage of 40 mg/kg. These findings demonstrate that modification of osimertinib can discover new potent EGFRC797S-TK inhibitors, and compound Os30 is a potent fourth-generation EGFR inhibitor to treat NSCLC with EGFmRC797S mutation.

Role of gefitinib in the targeted treatment of non-small-cell lung cancer in Chinese patients.

Non-small-cell lung cancer (NSCLC) is the most common type of lung cancer. Conventional treatment options have limited efficacy because most cases are in the advanced stage at the time of diagnosis. In recent years, gefitinib, an epidermal growth factor receptor tyrosine kinase inhibitor, has shown its good antitumor activities in treating NSCLC in a number of studies. This paper reviews its role in the targeted treatment of NSCLC in Chinese patients.