51. Oct4 plays a crucial role in the maintenance of gefitinib-resistant lung cancer stem cells
- Author
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Muneaki Hashimoto, Takeshi Nara, Mariko Moriyama, Hiroyuki Moriyama, Naoko Shimada, Akiko Murakami, Shigehiro Yagishita, Kazuhisa Takahashi, Shinichi Sasaki, Moulid Hidayat, Fumiyuki Takahashi, Fariz Nurwidya, Kentaro Suina, Isao Kobayashi, Ken Tajima, and Yasuko Yoshioka
- Subjects
0301 basic medicine ,Lung Neoplasms ,Biochemistry ,Mice ,0302 clinical medicine ,Mice, Inbred NOD ,Carcinoma, Non-Small-Cell Lung ,Epidermal growth factor receptor ,AC133 Antigen ,Hypoxia ,Gefitinib ,Transfection ,Exons ,Immunohistochemistry ,EGFR Exon 19 Deletion Mutation ,ErbB Receptors ,Phenotype ,030220 oncology & carcinogenesis ,embryonic structures ,Neoplastic Stem Cells ,Female ,biological phenomena, cell phenomena, and immunity ,Stem cell ,medicine.drug ,Biophysics ,Antineoplastic Agents ,Biology ,Real-Time Polymerase Chain Reaction ,03 medical and health sciences ,Cancer stem cell ,Antigens, CD ,Cell Line, Tumor ,medicine ,Animals ,Humans ,Lung cancer ,neoplasms ,Molecular Biology ,Cell Proliferation ,Glycoproteins ,fungi ,Cell Biology ,medicine.disease ,respiratory tract diseases ,030104 developmental biology ,Microscopy, Fluorescence ,Drug Resistance, Neoplasm ,Immunology ,Mutation ,Cancer research ,biology.protein ,Quinazolines ,Peptides ,Octamer Transcription Factor-3 ,Gene Deletion ,Neoplasm Transplantation - Abstract
Several recent studies have suggested that cancer stem cells (CSCs) are involved in resistance to gefitinib in non-small cell lung cancer (NSCLC). Oct4, a member of the POU-domain transcription factor family, has been shown to be involved in CSC properties of various cancers. We previously reported that Oct4 and the putative lung CSC marker CD133 were highly expressed in gefitinib-resistant persisters (GRPs) in NSCLC cells, and GRPs exhibited characteristic features of the CSCs phenotype. The aim of this study was to elucidate the role of Oct4 in the resistance to gefitinib in NSCLC cells with an activating epidermal growth factor receptor (EGFR) mutation. NSCLC cell lines, PC9, which express the EGFR exon 19 deletion mutation, were transplanted into NOG mice, and were treated with gefitinib in vivo. After 14-17 days of gefitinib treatment, the tumors still remained; these tumors were referred to as gefitinib-resistant tumors (GRTs). PC9-GRTs showed higher expression of Oct4 and CD133. To investigate the role of Oct4 in the maintenance of gefitinib-resistant lung CSCs, we introduced the Oct4 gene into PC9 and HCC827 cells carrying an activating EGFR mutation by lentiviral infection. Transfection of Oct4 significantly increased CD133-positive GRPs and the number of sphere formation, reflecting the self-renewal activity, of PC9 and HCC827 cells under the high concentration of gefitinib in vitro. Furthermore, Oct4-overexpressing PC9 cells (PC9-Oct4) significantly formed tumors at 1 × 10 cells/injection in NOG mice as compared to control cells. In addition, PC9-Oct4 tumors were more resistant to gefitinib treatment as compared to control cells in vivo. Finally, immunohistochemical analysis revealed that Oct4 was highly expressed in tumor specimens of EGFR-mutant NSCLC patients with acquired resistance to gefitinib. Collectively, these findings suggest that Oct4 plays a pivotal role in the maintenance of lung CSCs resistant to gefitinib in EGFR mutation-positive NSCLC.
- Published
- 2016