Experimental Study Of Aumolertinib Combined With Radiation Therapy In EGFR-mutated NSCLC Brain Metastases Tumor

Aumolertinib is an irreversible third-generation epidermal growth factor receptor tyrosine kinase inhibitor(EGFR-TKI),although it has been administered for the treatment of epidermal growth factor receptor(EGFR)mutant non-small cell lung cancer(NSCLC).However,it is unclear whether the central nervous system is a common metastatic site of EGFR mutation NSCLC,because of the poor prognosis and lack of good treatment strategy,it has become the focus of clinical attention.We want to explore whether aumolertinib combined with radiation therapy(RT)has potential therapeutic effects in treating brain metastases(BM)tumors from NSCLC.Objective:This study explored the anti-tumor effects of aumolertinib combined with RT in epidermal growth factor receptor mutated(EGFRm)NSCLC BM tumors.Methods:First,we established a brain metastases model of NSCLC in BALB/c nude mice and assessed the anti-tumor effects of aumolertinib combined with radiotherapy by observing the size of intracranial tumors,weight change and survival time of mice;Furthermore,we examined the concentrations of aumolertinib in brain tissue and blood using liquid chromatography-mass spectrometry(LC-MS);after that,we used CCK-8,colony formation,flow cytometry assay,and immunofluorescence staining to detect the effects of aumolertinib combined with RT upon PC-9 and NCI-H1975 cells,such as cell proliferation,survival,apoptosis,cycle distribution,the situation of DNA damage,and the expression levels of apoptosis-related Caspase3,Cleaved-caspase3,PARP,Cleaved-PARP,and cycle-related proteins CDK1,p CDK1 which were detected via western blot;finally,we chose a clinical case with which to explore the clinical benefits to the EGFRm NSCLC BM patient after the treatment of the combination of aumolertinib and radiotherapy.Results:1.The combination of aumolertinib and radiotherapy has a good effect in brain metastases tumor miceIn this study,aumolertinib and radiotherapy can inhibit the growth of intracranial tumors in mice,and the anti-tumor effect is better after the combination of them.Also,we tested the behavior of mice by vertical pole and sticky dot test,compared with radiotherapy alone,the neurological function of mice treated with aumolertinib combined with radiotherapy was significantly improved,and the combination of aumolertinib and radiotherapy enhanced the intracranial anti-tumor effect of mice.2.Combination with radiotherapy increases the intracranial accumulation of aumolertinib in brain metastases tumor miceAfter treatments,we detected the drug concentration in the plasma and brain tissue of mice with brain metastasis in the treatment group of aumolertinib alone and aumolertinib combined with radiotherapy respectively.The results showed that the drug concentration in the brain of mice in the combined treatment group was higher than aumolertinib alone.3.Aumolertinib combined with radiotherapy synergistically inhibits cell proliferation and survivalWe tested the effect of aumolertinib combined with radiotherapy on cell proliferation and survival.The results showed that aumolertinib and radiotherapy could inhibit cell proliferation and survival,and the effect of combination treatment was more obvious.By calculating the CI value,it was proved that aumolertinib combined with radiotherapy had a synergistic effect.4.Combination of aumolertinib and radiotherapy increase cell apoptosisThe effect of aumolertinib combined with radiotherapy on apoptosis of PC-9 and H1975 cells was investigated by flow cytometry.The results showed that compared with aumolertinib and radiotherapy alone,the combination increased the proportion of cell apoptosis.5.Combination of aumolertinib and radiotherapy alter the cell cycle distributionThe effect of aumolertinib combined with radiotherapy on cycle distribution of PC-9 and H1975 cells was investigated by flow cytometry.The results showed that compared with the control group,the proportion of G1-phase cells was significantly increased and the proportion of S-phase cells was significantly decreased under the combination of aumolertinib and radiotherapy.6.Aumolertinib combined with radiotherapy shows a good anti-tumor effect in patients with brain metastases from EGFRm NSCLCA patient with brain metastases from EGFRm NSCLC received 51Gy/17 F brain radiotherapy and 110 mg of aumolertinib po qd.After three months of treatment,the patient’s intracranial tumor was partially relieved and there was no obvious adverse reaction.Conclusion:Our study demonstrated that the combination of aumolertinib and radiotherapy has a good anti-tumor effect in EGFRm NSCLC and this combined treatment modality may be a potential therapeutic strategy for EGFR-mutant NSCLC BM patients clinically.