Si J, Ma Y, Bi JW, Xiong Y, Lv C, Li S, Wu N, Yang Y.
Shisa3 brakes resistance to EGFR-TKIs in lung adenocarcinoma by suppressing cancer stem cell properties.
JOURNAL OF EXPERIMENTAL & CLINICAL CANCER RESEARCH : CR 2019;
38:481. [PMID:
31801598 PMCID:
PMC6894286 DOI:
10.1186/s13046-019-1486-3]
[Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/30/2019] [Accepted: 11/22/2019] [Indexed: 12/31/2022]
Abstract
Background
Although EGFR tyrosine kinase inhibitors (EGFR-TKIs) are beneficial to lung adenocarcinoma patients with sensitive EGFR mutations, resistance to these inhibitors induces a cancer stem cell (CSC) phenotype. Here, we clarify the function and molecular mechanism of shisa3 as a suppressor that can reverse EGFR-TKI resistance and inhibit CSC properties.
Methods
The suppresser genes involved in EGFR-TKI resistance were identified and validated by transcriptome sequencing, quantitative real-time PCR (qRT-PCR) and immunohistochemistry. Biological function analyses, cell half maximal inhibitory concentration (IC50), self-renewal, and migration and invasion capacities, were detected by CCK8, sphere formation and Transwell assays. Tumorigenesis and therapeutic effects were investigated in nonobese diabetic/severe combined immunodeficiency (nod-scid) mice. The underlying mechanisms were explored by Western blot and immunoprecipitation analyses.
Results
We found that low expression of shisa3 was related to EGFR-TKI resistance in lung adenocarcinoma patients. Ectopic overexpression of shisa3 inhibited CSC properties and the cell cycle in the lung adenocarcinoma cells resistant to gefitinib/osimertinib. In contrast, suppression of shisa3 promoted CSC phenotypes and the cell cycle in the cells sensitive to EGFR-TKIs. For TKI-resistant PC9/ER tumors in nod-scid mice, overexpressed shisa3 had a significant inhibitory effect. In addition, we verified that shisa3 inhibited EGFR-TKI resistance by interacting with FGFR1/3 to regulate AKT/mTOR signaling. Furthermore, combinational administration of inhibitors of FGFR/AKT/mTOR and cell cycle signaling could overcome EGFR-TKI resistance associated with shisa3-mediated CSC capacities in vivo.
Conclusion
Taken together, shisa3 was identified as a brake to EGFR-TKI resistance and CSC characteristics, probably through the FGFR/AKT/mTOR and cell cycle pathways, indicating that shisa3 and concomitant inhibition of its regulated signaling may be a promising therapeutic strategy for reversing EGFR-TKI resistance.
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