Effects Of AZD9291 Monotherapy Or Combined With Radiation On Human Bronchial Epithelial Cells Lung Tissue In Mice

Back ground:Lung cancer is one of the most common malignant tumors in the world.It can be divided into two categories according the difference of biological behavior,small cell lung cancer(SCLC)and non small cell lung cancer(NSCLC).NSCLC accounts for about 85% of all lung cancers,and epidermal growth factor receptor(EGFR)mutations account for approximately 10-15% and 40% of NSCLC in Western and Asian populations.For this population,epidermal growth factor receptor tyrosine kinase inhibitor(EGFR-TKIs)is one of the important treatment.So far,EGFR-TKIs has been developed to the third generation.The first-generation drug gefitinib and erlotinib were reversible inhibitors for deletions in exon 19(EGFR del19)and exon 21 L858 R mutation(EGFR L858R).The second-generation EGFR-TKIs,afatinib and dacomitinib,are irreversible EGFR-TKIs,which aim to have more potent EGFR tyrosine kinase inhibition and to target other Erb B-family members,including HER2.The third generation drugs AZD9291,CO-1686,HM61713,were highly selective and irreversible inhibitors to inhibit EGFR T790 M while sparing wild-type EGFR.EGFR-TKIs monotherapy are first-line treatment of NSCLC harboring activating EGFR mutations.Fundamental research demonstrated that EGFR-TKIs has fuction of radiosensitivity,clinical research shows that targeted therapy in combination with radiotherapy can improve the survival and may also as an alternative therapy when patients cannot tolerate the chemotherapy.Howere,EGFR-TKI monotherapy may lead Low morbidity and high mortality interstitial pneumonia,and the probability of pulmonary toxicity for TKIs combined with radiotherapy is different.AZD9291 is the third generation new drugs that are highly selective for T790 M mutation,and its toxicity has been a concern for cliniciansthis.In this study,we will detect the influence AZD9291 monotherapy or combined with radiotherapy on human lung / bronchial epithelial cells(BEAS-2B)fuction in vitro and the injury degree in mice in vivo,providing the reference for the lung safety of AZD9291 monotherapy or combined with radiation.Merhod:Selecting human lung / bronchus epithelioid cell line BEAS-2B for in vitro experiment,and C57BL/6 mice for in vivo experiment.Divided into control group,the single drug group(AZD9291),radiotherapy group and radiotherapy combined with AZD9291 group,MTS/Acumen technology to detecte cell viability,Flow cytometry to detect cell cycle,immunohistochemistry to detect the expression of ?-H2 AX in mice lung tissue,H&E to detect the pulmonory inflamation.Result:1.Cell viability assay(1)AZD9291 alone group with concentration of 20 nm,250nm,700nm(Clinical medication 80mg/kg/d in patients the highest effective blood drug concentration was 635nM)cell viability have no significant difference than the control group((P>0.674);(2)radiotherapy group significantly inhibit BEAS-2B cell viability(2Gy?4Gy?8Gy group compared to the control group the P value are 0.066,0.001,<0.001);AZD9291 combined with radiotherapy group did not further inhibit cell viability compared with radiotherapy alone group(P =0.967).2.Cell cycle experiment(1)AZD9291 alone group with concentration of 20 nm,250nm,700 nm cell cycle have no significant difference than the control group(P > 0.05)(2)radiotherapy induced BEAS-2B G2/M arrest(P =0.011),AZD9291 combined with radiotherapy group did not further increase cell cycle arrest compared with radiotherapy alone group.3 Immunohistochemical detect the ?-H2 AX expression level in the C57BL/6 mice lung tissue(1)The?-H2 AX expression level in AZD9291 group has no significant difference Compared with the control group(P =0.9);(2)2Gy × 5F radiation group significantly increase the level of gamma-H2 AX in mice lung tissue(P =0.011);15Gy single dose irradiation group significantly increased the level of gamma-H2 AX in lung tissue(P =0.001);there have no difference between combined group and radiation group(P =0.308).4.H&E staining results(1)one mice had mild pneumonia in AZD9291 single drug group in third week,thepneumonia probability was20%(1/5);(2)one mice had mild pulmonary fibrosis in AZD9291 combined 15Gy×1f radiation group in 3 month,the fibrosis probability was 20%(1/5)Conclusion:The in vitro and in vivo experiment indicate that in the range of clinical medicine dose,AZD9291 alone has no damage effect on BEAS-2B cell.but the animal experiment cannot exclude the interstitial pneumonia possibility;AZD9291 combined with radiotherapy cannot increase the radiation induced injury to BEAS-2B cells or increase the radiation induced DNA damage,the combined therapy cannot exclude the pulmonary toxicity possibility...