Pei San Yee1,2, Nur Syafinaz Zainal1,2, Chai Phei Gan1, Bernard K B Lee1,2, Kein Seong Mun3, Mannil Thomas Abraham4, Siti Mazlipah Ismail2, Zainal Ariff Abdul Rahman2, Vyomesh Patel1, Sok Ching Cheong5,6. 1. Head and Neck Cancer Research Team, Cancer Research Malaysia, No. 1, Jalan SS12/1A, 47500, Subang Jaya, Selangor, Malaysia. 2. Department of Oral and Maxillofacial Clinical Sciences, Faculty of Dentistry, University of Malaya, Kuala Lumpur, Malaysia. 3. Department of Pathology, Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia. 4. Department of Oral and Maxillofacial Surgery, Tengku Ampuan Rahimah Hospital, Klang, Malaysia. 5. Head and Neck Cancer Research Team, Cancer Research Malaysia, No. 1, Jalan SS12/1A, 47500, Subang Jaya, Selangor, Malaysia. sokching.cheong@cancerresearch.my. 6. Department of Oral and Maxillofacial Clinical Sciences, Faculty of Dentistry, University of Malaya, Kuala Lumpur, Malaysia. sokching.cheong@cancerresearch.my.
Abstract
BACKGROUND: Given that aberrant activation of epidermal growth factor receptor family receptors (ErbB) is a common event in oral squamous cell carcinoma, and that high expression of these receptor proteins is often associated with poor prognosis, this rationalizes the approach of targeting ErbB signaling pathways to improve the survival of patients with oral squamous cell carcinoma. However, monotherapy with the ErbB blocker afatinib has shown limited survival benefits. OBJECTIVES: This study was performed to identify mechanisms of afatinib resistance and to explore potential afatinib-based combination treatments with other targeted inhibitors in oral squamous cell carcinoma. METHODS: We determined the anti-proliferative effects of afatinib on a panel of oral squamous cell carcinoma cell lines using a crystal violet-growth inhibition assay, click-iT 5-ethynyl-2'-deoxyuridine staining, and cell-cycle analysis. Biochemical assays were performed to study the underlying mechanism of drug treatment as a single agent or in combination with the MEK inhibitor trametinib. We further evaluated and compared the anti-tumor effects of single agent and combined treatment by using oral squamous cell carcinoma xenograft models. RESULTS: In this study, we showed that afatinib inhibited oral squamous cell carcinoma cell proliferation via cell-cycle arrest at the G0/G1 phase, and inhibited tumor growth in xenograft mouse models. Interestingly, we demonstrated reactivation of the mitogen-activated protein kinase (ERK1/2) pathway in vitro, which possibly reduced the effects of ErbB inhibition. Concomitant treatment of oral squamous cell carcinoma cells with afatinib and trametinib synergized the anti-tumor effects in oral squamous cell carcinoma-bearing mouse models. CONCLUSIONS: Our findings provide insight into the molecular mechanism of resistance to afatinib and support further clinical evaluation into the combination of afatinib and MEK inhibition in the treatment of oral squamous cell carcinoma.
BACKGROUND: Given that aberrant activation of epidermal growth factor receptor family receptors (ErbB) is a common event in oral squamous cell carcinoma, and that high expression of these receptor proteins is often associated with poor prognosis, this rationalizes the approach of targeting ErbB signaling pathways to improve the survival of patients with oral squamous cell carcinoma. However, monotherapy with the ErbB blocker afatinib has shown limited survival benefits. OBJECTIVES: This study was performed to identify mechanisms of afatinib resistance and to explore potential afatinib-based combination treatments with other targeted inhibitors in oral squamous cell carcinoma. METHODS: We determined the anti-proliferative effects of afatinib on a panel of oral squamous cell carcinoma cell lines using a crystal violet-growth inhibition assay, click-iT 5-ethynyl-2'-deoxyuridine staining, and cell-cycle analysis. Biochemical assays were performed to study the underlying mechanism of drug treatment as a single agent or in combination with the MEK inhibitor trametinib. We further evaluated and compared the anti-tumor effects of single agent and combined treatment by using oral squamous cell carcinoma xenograft models. RESULTS: In this study, we showed that afatinib inhibited oral squamous cell carcinoma cell proliferation via cell-cycle arrest at the G0/G1 phase, and inhibited tumor growth in xenograft mouse models. Interestingly, we demonstrated reactivation of the mitogen-activated protein kinase (ERK1/2) pathway in vitro, which possibly reduced the effects of ErbB inhibition. Concomitant treatment of oral squamous cell carcinoma cells with afatinib and trametinib synergized the anti-tumor effects in oral squamous cell carcinoma-bearing mouse models. CONCLUSIONS: Our findings provide insight into the molecular mechanism of resistance to afatinib and support further clinical evaluation into the combination of afatinib and MEK inhibition in the treatment of oral squamous cell carcinoma.
Authors: Caroline Robert; Boguslawa Karaszewska; Jacob Schachter; Piotr Rutkowski; Andrzej Mackiewicz; Daniil Stroiakovski; Michael Lichinitser; Reinhard Dummer; Florent Grange; Laurent Mortier; Vanna Chiarion-Sileni; Kamil Drucis; Ivana Krajsova; Axel Hauschild; Paul Lorigan; Pascal Wolter; Georgina V Long; Keith Flaherty; Paul Nathan; Antoni Ribas; Anne-Marie Martin; Peng Sun; Wendy Crist; Jeff Legos; Stephen D Rubin; Shonda M Little; Dirk Schadendorf Journal: N Engl J Med Date: 2014-11-16 Impact factor: 91.245
Authors: J Rubin Grandis; M F Melhem; W E Gooding; R Day; V A Holst; M M Wagener; S D Drenning; D J Tweardy Journal: J Natl Cancer Inst Date: 1998-06-03 Impact factor: 13.506
Authors: Flavio Solca; Goeran Dahl; Andreas Zoephel; Gerd Bader; Michael Sanderson; Christian Klein; Oliver Kraemer; Frank Himmelsbach; Eric Haaksma; Guenther R Adolf Journal: J Pharmacol Exp Ther Date: 2012-08-10 Impact factor: 4.030
Authors: Lucia Regales; Yixuan Gong; Ronglai Shen; Elisa de Stanchina; Igor Vivanco; Aviva Goel; Jason A Koutcher; Maria Spassova; Ouathek Ouerfelli; Ingo K Mellinghoff; Maureen F Zakowski; Katerina A Politi; William Pao Journal: J Clin Invest Date: 2009-09-14 Impact factor: 14.808
Authors: D Li; L Ambrogio; T Shimamura; S Kubo; M Takahashi; L R Chirieac; R F Padera; G I Shapiro; A Baum; F Himmelsbach; W J Rettig; M Meyerson; F Solca; H Greulich; K-K Wong Journal: Oncogene Date: 2008-04-14 Impact factor: 9.867
Authors: James A Bonner; Paul M Harari; Jordi Giralt; Roger B Cohen; Christopher U Jones; Ranjan K Sur; David Raben; Jose Baselga; Sharon A Spencer; Junming Zhu; Hagop Youssoufian; Eric K Rowinsky; K Kian Ang Journal: Lancet Oncol Date: 2009-11-10 Impact factor: 41.316
Authors: Lynn M Knowles; Laura P Stabile; Ann Marie Egloff; Mary E Rothstein; Sufi M Thomas; Christopher T Gubish; Edwina C Lerner; Raja R Seethala; Shinsuke Suzuki; Kelly M Quesnelle; Sarah Morgan; Robert L Ferris; Jennifer R Grandis; Jill M Siegfried Journal: Clin Cancer Res Date: 2009-05-26 Impact factor: 12.531