Tzong-Shyuan Tai1, Pai-Mei Lin2, Ching-Fang Wu2,3, Shih-Kai Hung4, Chung-I Huang5, Chih-Chun Wang6, Yu-Chieh Su7,8. 1. Department of Medical Research, E-Da Hospital, Kaohsiung, Taiwan, R.O.C. 2. School of Medicine, I-Shou University, Kaohsiung, Taiwan, R.O.C. 3. Division of Nephrology, E-Da Hospital, Kaohsiung, Taiwan, R.O.C. 4. Department of Radiation Oncology, Dalin Tzu Chi Hospital, Buddhist Tzu Chi Medical Foundation, ChiaYi, Taiwan, R.O.C. 5. Department of Radiation Oncology, E-Da Cancer Hospital, Kaohsiung, Taiwan, R.O.C. 6. Department of Otolaryngology, E-Da Hospital, Kaohsiung, Taiwan, R.O.C. 7. Division of Hematology-Oncology, Department of Internal Medicine, Kaohsiung Medical University Hospital, Kaohsiung, Taiwan, R.O.C. hepatoma@gmail.com. 8. Faculty of Medicine, Kaohsiung Medical University, Kaohsiung, Taiwan, R.O.C.
Abstract
BACKGROUND: Radiotherapy (RT) combined with a radiosensitizer represents an important treatment for head and neck squamous cell carcinoma (HNSCC). Only few chemotherapy agents are currently approved as radiosensitizers for targeted therapy. In this study, the potent cyclin-dependent kinase 4/6 (CDK4/6) inhibitor LEE011 was tested for potential to act as a radiosensitizer during RT. MATERIALS AND METHODS: RT enhancement by LEE011 was assessed by in vitro clonogenic assay, flow cytometry, and western blot in a variety of HNSCC cell lines. The HNSCC cell line OML1 and its radiation-resistant clone OML1-R were used. RESULTS: LEE011 induced cell-cycle arrest in SCC4/SCC25 cells during the G1/M phase through inhibition of retinoblastoma protein phosphorylation. LEE011 enhanced the effects of radiation in OML1 cells and overcame radiation resistance in OML1-R cells. CONCLUSION: LEE011 is a potential radiosensitizer that can enhance the cytotoxic effects of RT. Clinical trials including LEE011 during RT for HNSCC should be considered. Copyright
BACKGROUND: Radiotherapy (RT) combined with a radiosensitizer represents an important treatment for head and neck squamous cell carcinoma (HNSCC). Only few chemotherapy agents are currently approved as radiosensitizers for targeted therapy. In this study, the potent cyclin-dependent kinase 4/6 (CDK4/6) inhibitor LEE011 was tested for potential to act as a radiosensitizer during RT. MATERIALS AND METHODS: RT enhancement by LEE011 was assessed by in vitro clonogenic assay, flow cytometry, and western blot in a variety of HNSCC cell lines. The HNSCC cell line OML1 and its radiation-resistant clone OML1-R were used. RESULTS:LEE011 induced cell-cycle arrest in SCC4/SCC25 cells during the G1/M phase through inhibition of retinoblastoma protein phosphorylation. LEE011 enhanced the effects of radiation in OML1 cells and overcame radiation resistance in OML1-R cells. CONCLUSION:LEE011 is a potential radiosensitizer that can enhance the cytotoxic effects of RT. Clinical trials including LEE011 during RT for HNSCC should be considered. Copyright
Authors: Andrea M Pesch; Nicole H Hirsh; Benjamin C Chandler; Anna R Michmerhuizen; Cassandra L Ritter; Marlie P Androsiglio; Kari Wilder-Romans; Meilan Liu; Christina L Gersch; José M Larios; Lori J Pierce; James M Rae; Corey W Speers Journal: Clin Cancer Res Date: 2020-09-23 Impact factor: 12.531