Kyoung Ho Pyo1, Sun Min Lim2, Hye Ryun Kim3, Young Hoon Sung4, Mi Ran Yun1, Sung-Moo Kim1, Hwan Kim1, Han Na Kang1, Ji Min Lee1, Sang Gyun Kim1, Chae Won Park1, Hyun Chang5, Hyo Sup Shim6, Han-Woong Lee7, Byoung Chul Cho8. 1. Yonsei Cancer Research Institute, JE-UK Laboratory of Molecular Cancer Therapeutics, Seoul, Republic of Korea. 2. Division of Medical Oncology, Department of Internal Medicine, CHA Bundang Medical Center, Seongnam, Kyeonggi-do, Republic of Korea; Division of Medical Oncology, Department of Internal Medicine, Yonsei University College of Medicine, Seoul, Republic of Korea. 3. Division of Medical Oncology, Department of Internal Medicine, Yonsei University College of Medicine, Seoul, Republic of Korea. 4. Department of Convergence Medicine, University of Ulsan College of Medicine and Asan Institute for Life Sciences, Asan Medical Center, Seoul, Republic of Korea. 5. Hematology and Medical Oncology, International St. Mary's Hospital, Catholic Kwandong University, College of Medicine, Incheon, Republic of Korea. 6. Department of Pathology, Yonsei University College of Medicine, Seoul, Republic of Korea. 7. Department of Biochemistry, College of Life Science and Biotechnology and Yonsei Laboratory Animal Research Center, Yonsei University, Seoul, Republic of Korea. 8. Division of Medical Oncology, Department of Internal Medicine, Yonsei University College of Medicine, Seoul, Republic of Korea. Electronic address: cbc1971@yuhs.ac.
Abstract
BACKGROUND: Anaplastic lymphoma receptor tyrosine kinase gene (ALK) fusion is a distinct molecular subclassification of NSCLC that is targeted by anaplastic lymphoma kinase (ALK) inhibitors. We established a transgenic mouse model that expresses tumors highly resembling human NSCLC harboring echinoderm microtubule associated protein like 4 gene (EML)-ALK fusion. We aimed to test an EML4-ALK transgenic mouse model as a platform for assessing the efficacy of ALK inhibitors and examining mechanisms of acquired resistance to ALK inhibitors. METHODS: Transgenic mouse lines harboring LoxP-STOP-LoxP-FLAGS-tagged human EML4-ALK (variant 1) transgene was established by using C57BL/6N mice. The transgenic mouse model with highly lung-specific, inducible expression of echinoderm microtubule associated protein like 4-ALK fusion protein was established by crossing the EML4-ALK transgenic mice with mice expressing Cre-estrogen receptor fusion protein under the control of surfactant protein C gene (SPC). Expression of EML4-ALK transgene was induced by intraperitoneally injecting mice with tamoxifen. When the lung tumor of the mice treated with the ALK inhibitor crizotinib for 2 weeks was measured, tumor shrinkage was observed. RESULTS: EML4-ALK tumor developed after 1 week of tamoxifen treatment. Echinoderm microtubule associated protein like 4-ALK was strongly expressed in the lung but not in other organs. ALK and FLAGS expressions were observed by immunohistochemistry. Treatment of EML4-ALK tumor-bearing mice with crizotinib for 2 weeks induced dramatic shrinkage of tumors with no signs of toxicity. Furthermore, prolonged treatment with crizotinib led to acquired resistance in tumors, resulting in regrowth and disease progression. The resistant tumor nodules revealed acquired ALK G1202R mutations. CONCLUSIONS: An EML4-ALK transgenic mouse model for study of drug resistance was successfully established with short duration of tumorigenesis. This model should be a strong preclinical model for testing efficacy of ALK TKIs, providing a useful tool for investigating the mechanisms of acquired resistance and pursuing novel treatment strategies in ALK-positive lung cancer.
BACKGROUND:Anaplastic lymphoma receptor tyrosine kinase gene (ALK) fusion is a distinct molecular subclassification of NSCLC that is targeted by anaplastic lymphoma kinase (ALK) inhibitors. We established a transgenic mouse model that expresses tumors highly resembling humanNSCLC harboring echinoderm microtubule associated protein like 4 gene (EML)-ALK fusion. We aimed to test an EML4-ALK transgenic mouse model as a platform for assessing the efficacy of ALK inhibitors and examining mechanisms of acquired resistance to ALK inhibitors. METHODS: Transgenic mouse lines harboring LoxP-STOP-LoxP-FLAGS-tagged humanEML4-ALK (variant 1) transgene was established by using C57BL/6N mice. The transgenic mouse model with highly lung-specific, inducible expression of echinoderm microtubule associated protein like 4-ALK fusion protein was established by crossing the EML4-ALKtransgenic mice with mice expressing Cre-estrogen receptor fusion protein under the control of surfactant protein C gene (SPC). Expression of EML4-ALK transgene was induced by intraperitoneally injecting mice with tamoxifen. When the lung tumor of the mice treated with the ALK inhibitor crizotinib for 2 weeks was measured, tumor shrinkage was observed. RESULTS:EML4-ALK tumor developed after 1 week of tamoxifen treatment. Echinoderm microtubule associated protein like 4-ALK was strongly expressed in the lung but not in other organs. ALK and FLAGS expressions were observed by immunohistochemistry. Treatment of EML4-ALK tumor-bearing mice with crizotinib for 2 weeks induced dramatic shrinkage of tumors with no signs of toxicity. Furthermore, prolonged treatment with crizotinib led to acquired resistance in tumors, resulting in regrowth and disease progression. The resistant tumor nodules revealed acquired ALKG1202R mutations. CONCLUSIONS: An EML4-ALK transgenic mouse model for study of drug resistance was successfully established with short duration of tumorigenesis. This model should be a strong preclinical model for testing efficacy of ALK TKIs, providing a useful tool for investigating the mechanisms of acquired resistance and pursuing novel treatment strategies in ALK-positive lung cancer.
Authors: Mi Ran Yun; Hun Mi Choi; You Won Lee; Hyeong Seok Joo; Chae Won Park; Jae Woo Choi; Dong Hwi Kim; Han Na Kang; Kyoung-Ho Pyo; Eun Joo Shin; Hyo Sup Shim; Ross A Soo; James Chih-Hsin Yang; Sung Sook Lee; Hyun Chang; Min Hwan Kim; Min Hee Hong; Hye Ryun Kim; Byoung Chul Cho Journal: EMBO Mol Med Date: 2019-10-21 Impact factor: 12.137