Luteolin is effective in the non-small cell lung cancer model with L858R/T790M EGF receptor mutation and erlotinib resistance.
OBJECTIVE
Non-small cell lung cancer (NSCLC) is one of the most commonly diagnosed malignancies in the world. Small-molecule inhibitors of the EGF receptor's tyrosine kinase domain (TKIs), including gefitinib and erlotinib, have been widely used for treating NSCLC. Unfortunately, nearly all patients after initially experiencing a marked improvement while on these drugs, eventually progress to acquire resistance to TKIs. Because there is no effective therapeutic strategy to treat TKI-resistant NSCLC, we evaluated the effects of luteolin, a naturally occurring flavanoid, on T790M mutant NSCLC cells.


METHODS
The effect of luteolin on the viability of NSCLC and normal cell lines was investigated using the Cell Counting Kit-8 (CCK-8) assay. Luteolin-induced apoptosis was assessed by bivariate FITC-annexin V/PI assay, and Western blots were used to measured apoptotic proteins. Co-immunoprecipitation was used to determine the effect of luteolin on the interaction between Hsp90 and mutant EGF receptors. The effect of luteolin on the Akt/mTOR pathway was studied using Western blotting analysis. Its anti-tumour efficacy in vivo was examined in a mouse xenograft model.


RESULTS
Luteolin exerted significant anti-tumourigenic effects on the EGF receptor L858R/T790M mutation and erlotinib-resistant NSCLC both at the cellular and animal levels. Mechanistically, luteolin induced degradation of the EGF receptor by inhibiting the association of Hsp90 with the mutant EGF receptor, and, therefore, prevented PI3K/Akt/mTOR signalling, which resulted in NSCLC cell apoptosis.


CONCLUSIONS
Luteolin may be a potential candidate for NSCLC therapy, especially for treatment of patients with acquired erlotinib-resistant NSCLC.
State Key Laboratory of Pharmaceutical Biotechnology, School of Life Sciences, Nanjing University, Nanjing, Jiangsu, China; Jiangsu Cancer Hospital, Nanjing, Jiangsu, China.
Zhuan
Z
Hong
Xiang
X
Cao
Na
N
Li
Yizhou
Y
Zhang
Lei
L
Lan
Yi
Y
Zhou
Xiaolong
X
Pan
Lei
L
Shen
Zhimin
Z
Yin
Lan
L
Luo
D000230:Adenocarcinoma / Q000188:drug therapy* / Q000235:genetics / Q000378:metabolism; D000818:Animals; D000970:Antineoplastic Agents / Q000494:pharmacology / Q000627:therapeutic use*; D017209:Apoptosis / Q000187:drug effects; D002289:Carcinoma, Non-Small-Cell Lung / Q000188:drug therapy* / Q000235:genetics / Q000378:metabolism; D045744:Cell Line, Tumor; D002470:Cell Survival / Q000187:drug effects; D019008:Drug Resistance, Neoplasm; D066246:ErbB Receptors / Q000235:genetics* / Q000378:metabolism; D000069347:Erlotinib Hydrochloride; D018841:HSP90 Heat-Shock Proteins / Q000378:metabolism; D006801:Humans; D008175:Lung Neoplasms / Q000188:drug therapy* / Q000235:genetics / Q000378:metabolism; D047311:Luteolin / Q000494:pharmacology / Q000627:therapeutic use*; D008297:Male; D008819:Mice, Nude; D009154:Mutation; D047428:Protein Kinase Inhibitors; D011799:Quinazolines
D000970:Antineoplastic Agents; D018841:HSP90 Heat-Shock Proteins; D047428:Protein Kinase Inhibitors; D011799:Quinazolines; D000069347:Erlotinib Hydrochloride; D066246:ErbB Receptors; D047311:Luteolin
EGFR; NSCLC; T790M mutation; apoptosis; luteolin