Chun-Shu Lin1, Oluwaseun Adebayo Bamodu2, Kuang-Tai Kuo3, Chih-Ming Huang4, Shao-Cheng Liu5, Chun-Hua Wang6, Yew-Min Tzeng7, Tsu-Yi Chao8, Chi-Tai Yeh9. 1. Department of Radiation Oncology, Tri-Service General Hospital, National Defense Medical Center, Taipei, Taiwan; Graduate Institute of Clinical Medicine, College of Medicine, Taipei Medical University, Taipei, Taiwan. 2. Department of Hematology and Oncology, Cancer Center, Taipei Medical University - Shuang Ho Hospital, New Taipei City 23561, Taiwan; Department of Medical Research and Education, Taipei Medical University - Shuang Ho Hospital, New Taipei City 23561, Taiwan. 3. Division of Thoracic Surgery, Department of Surgery, Shuang Ho Hospital, Taipei Medical University, New Taipei City, Taiwan; Division of Thoracic Surgery, Department of Surgery, School of Medicine, College of Medicine, Taipei Medical University, Taipei, Taiwan. 4. Department of Otolaryngology, Taitung Mackay Memorial Hospital, Taiwan. 5. Department of Otolaryngology - Head and Neck Surgery, Tri-Service General Hospital, National Defense Medical Center, Taipei, Taiwan. 6. Department of Dermatology, Taipei Tzu Chi Hospital, Buddhist Tzu Chi Medical Foundation, New Taipei City, Taiwan; School of Medicine, Buddhist Tzu Chi University, Hualien, Taiwan. 7. Center for General Education, National Taitung University, Taitung, Taiwan; Department of Applied Chemistry, Chaoyang University of Technology, Taichung, Taiwan. 8. Graduate Institute of Clinical Medicine, College of Medicine, Taipei Medical University, Taipei, Taiwan; Department of Hematology and Oncology, Cancer Center, Taipei Medical University - Shuang Ho Hospital, New Taipei City 23561, Taiwan. Electronic address: 10575@s.tmu.edu.tw. 9. Graduate Institute of Clinical Medicine, College of Medicine, Taipei Medical University, Taipei, Taiwan; Department of Hematology and Oncology, Cancer Center, Taipei Medical University - Shuang Ho Hospital, New Taipei City 23561, Taiwan; Department of Medical Research and Education, Taipei Medical University - Shuang Ho Hospital, New Taipei City 23561, Taiwan. Electronic address: ctyeh@s.tmu.edu.tw.
Abstract
BACKGROUND: The cancer stem cells (CSCs) have been shown to play key roles in the oral cancer initiation, distant metastasis, the development of chemoresistance and recurrence after treatment. Therefore, the inhibition of oral CSCs has been the target for therapeutic development. PURPOSE: In this study, we investigated the anti-CSCs potential of Ovatodiolide (Ova), a diterpenoid isolate of Anisomeles indica, in vitro and in vivo. METHODS: Oral CSCs were treated with Ova, and the expression of pluripotency factors Oct4, Sox-2, and Nanog were evaluated by western blot. Effect of Ova on self-renewal capacity and clonogenicity were assessed with the sphere formation and clonogenic assay in CSCs model derived from oral cancer cell. The effect of Ova was also investigated in a mouse xenograft model obtained by injecting nude mice with oral CSCs cells. RESULTS: We demonstrated that Ova significantly and dose-dependently suppressed oral cancer cell viability and colony formation; Ova markedly inhibited the ALDH1 activities and reduced the CD44high/ALDHrich cell sub-population. Additionally, Ova suppressed orosphere formation by down-regulating CD133, Klf4, Oct4A, Nanog and JARID1B expression. Furthermore, Ova-mediated anti-cancer effects were associated with the dose-dependent reduction in the expression levels of STAT3, p-STAT3, pJAK2, pAKT and pERK1/2 protein. Moreover, Ova synergistically enhanced the anticancer effect of cisplatin against the SAS, FaDu, HSC-3 and TW2.6 orospheres. Ova significantly attenuated the tumor-initiating potential of orosphere in mouse xegnograft model. CONCLUSION: These results demonstrate that Ova effectively suppressed oral tumorigenesis and stemness properties via JAK2/STAT3 signaling. Ova may be considered for future clinical usage.
BACKGROUND: The cancer stem cells (CSCs) have been shown to play key roles in the oral cancer initiation, distant metastasis, the development of chemoresistance and recurrence after treatment. Therefore, the inhibition of oral CSCs has been the target for therapeutic development. PURPOSE: In this study, we investigated the anti-CSCs potential of Ovatodiolide (Ova), a diterpenoid isolate of Anisomeles indica, in vitro and in vivo. METHODS: Oral CSCs were treated with Ova, and the expression of pluripotency factors Oct4, Sox-2, and Nanog were evaluated by western blot. Effect of Ova on self-renewal capacity and clonogenicity were assessed with the sphere formation and clonogenic assay in CSCs model derived from oral cancer cell. The effect of Ova was also investigated in a mouse xenograft model obtained by injecting nude mice with oral CSCs cells. RESULTS: We demonstrated that Ova significantly and dose-dependently suppressed oral cancer cell viability and colony formation; Ova markedly inhibited the ALDH1 activities and reduced the CD44high/ALDHrich cell sub-population. Additionally, Ova suppressed orosphere formation by down-regulating CD133, Klf4, Oct4A, Nanog and JARID1B expression. Furthermore, Ova-mediated anti-cancer effects were associated with the dose-dependent reduction in the expression levels of STAT3, p-STAT3, pJAK2, pAKT and pERK1/2 protein. Moreover, Ova synergistically enhanced the anticancer effect of cisplatin against the SAS, FaDu, HSC-3 and TW2.6 orospheres. Ova significantly attenuated the tumor-initiating potential of orosphere in mouse xegnograft model. CONCLUSION: These results demonstrate that Ova effectively suppressed oral tumorigenesis and stemness properties via JAK2/STAT3 signaling. Ova may be considered for future clinical usage.