Effect of AZD1480 in an epidermal growth factor receptor-driven lung cancer model.
OBJECTIVE
STAT3 plays a vital role in inducing and maintaining a pro-carcinogenic inflammatory microenvironment and is reported to be a critical mediator of the oncogenic effects of EGFR mutations. STAT3 activation is mediated through JAK family kinases. We investigated the effect of the JAK1/2 inhibitor AZD1480 on lung tumors induced by an activating EGFR mutation.


MATERIALS AND METHODS
Three EGFR tyrosine kinase inhibitor-resistant cell lines (RPC-9, PC-9/Van-R and PC-9/ER3) established from PC-9 harboring an EGFR exon19 deletion mutation were used. Growth inhibition was measured using an MTT assay. Effects of AZD1480 were also evaluated in the xenograft model and in the EGFR transgenic mice model. Protein expressions were assessed by immunoblotting and immunohistochemistry. Group differences were compared using Student's t-test. To evaluate the efficacy of AZD1480 on survival, AZD1480 or vehicle was administered orally from 7 weeks of age of the transgenic mice. Overall survival curves were calculated using the Kaplan-Meier method.


RESULTS
The sensitivities of resistant and parent cells to AZD1480 were similar in vitro. AZD1480 (30 or 50 mg/kg/day, per os) reduced angiogenesis and revealed significant tumor regression in a mouse xenograft model. Subsequently, the transgenic mice were treated with AZD1480 (30 mg/kg/day) or vehicle alone. The numbers of lung tumors (long axis exceeding 1mm) in the AZD1480-treated group and control group were 0.37±0.18 and 2.25±0.53 (p<0.001), respectively. AZD1480 treatment suppressed pSTAT3, pJAK1, pJAK2 and angiogenesis. The median survival time in the AZD1480-treated group (217 days) was significantly greater than that in the control group (106 days) (log-rank test, p<0.0001).


CONCLUSION
AZD1480 may be effective against lung tumors driven by an activating EGFR mutation.
['Murakami|Toshi|T|', 'Takigawa|Nagio|N|', 'Ninomiya|Takashi|T|', 'Ochi|Nobuaki|N|', 'Yasugi|Masaaki|M|', 'Honda|Yoshihiro|Y|', 'Kubo|Toshio|T|', 'Ichihara|Eiki|E|', 'Hotta|Katsuyuki|K|', 'Tanimoto|Mitsune|M|', 'Kiura|Katsuyuki|K|']
D000818:Animals D048708:Cell Growth Processes D045744:Cell Line, Tumor D066246:ErbB Receptors D005091:Exons D005260:Female D006801:Humans D053614:Janus Kinase 2 D008175:Lung Neoplasms D051379:Mice D008819:Mice, Nude D008822:Mice, Transgenic D009154:Mutation D009368:Neoplasm Transplantation D018919:Neovascularization, Physiologic D011720:Pyrazoles D011743:Pyrimidines D050796:STAT3 Transcription Factor D015533:Transcriptional Activation D047368:Tumor Burden D023041:Xenograft Model Antitumor Assays
Lung cancer STAT3 EGFR Transgenic mice JAK2 Oncogene addiction