Aspirin exerts high anti-cancer activity in PIK3CA -mutant colon cancer cells

// Mancang Gu 1, 2 , Reiko Nishihara 1, 3, 4, 5, 6 , Yang Chen 1, 7 , Wanwan Li 1 , Yan Shi 1, 7 , Yohei Masugi 1 , Tsuyoshi Hamada 1 , Keisuke Kosumi 1 , Li Liu 1, 3 , Annacarolina da Silva 1 , Jonathan A. Nowak 6 , Tyler Twombly 1 , Chunxia Du 1 , Hideo Koh 1 , Wenbin Li 1 , Jeffrey A. Meyerhardt 8 , Brian M. Wolpin 8 , Marios Giannakis 8 , Andrew J. Aguirre 8 , Adam J. Bass 8, 9, 10 , David A. Drew 11, 12 , Andrew T. Chan 11, 12 , Charles S. Fuchs 13, 14, 15, * , Zhi Rong Qian 1, 6, * and Shuji Ogino 1, 4, 6, * 1 Department of Oncologic Pathology, Dana-Farber Cancer Institute and Harvard Medical School, Boston, MA, USA 2 College of Pharmacy, Zhejiang Chinese Medical University, Hangzhou, P.R. China 3 Department of Nutrition, Harvard T.H. Chan School of Public Health, Boston, MA, USA 4 Department of Epidemiology, Harvard T.H. Chan School of Public Health, Boston, MA, USA 5 Department of Biostatistics, Harvard T.H. Chan School of Public Health, Boston, MA, USA 6 Program in MPE Molecular Pathological Epidemiology, Department of Pathology, Brigham and Women’s Hospital and Harvard Medical School, Boston, MA, USA 7 Medical Oncology Department 2, Chinese People’s Liberation Army General Hospital, Beijing, P.R. China 8 Department of Medical Oncology, Dana-Farber Cancer Institute and Harvard Medical School, Boston, MA, USA 9 Broad Institute of MIT and Harvard, Cambridge, MA, USA 10 Department of Medicine, Brigham and Women's Hospital and Harvard Medical School, Boston, MA, USA 11 Clinical and Translational Epidemiology Unit, Massachusetts General Hospital and Harvard Medical School, Boston, MA, USA 12 Division of Gastroenterology, Massachusetts General Hospital, Boston, MA, USA 13 Yale Cancer Center, New Haven, CT, USA 14 Department of Medicine, Yale School of Medicine, New Haven, CT, USA 15 Smilow Cancer Hospital, New Haven, CT, USA * These authors contributed equally to this work Correspondence to: Zhi Rong Qian, email: zhirong_qian@dfci.harvard.edu Shuji Ogino, email: shuji_ogino@dfci.harvard.edu Keywords: anti-tumor effect, colorectal cancer, isogenic cell model, NSAID, PI3K Received: May 31, 2017      Accepted: August 31, 2017      Published: September 18, 2017 ABSTRACT Evidence suggests that nonsteroidal anti-inflammatory drug aspirin (acetylsalicylic acid) may improve patient survival in PIK3CA -mutant colorectal carcinoma, but not in PIK3CA -wild-type carcinoma. However, whether aspirin directly influences the viability of PIK3CA -mutant colon cancer cells is poorly understood. We conducted in vitro experiments to test our hypothesis that the anti-proliferative activity of aspirin might be stronger for PIK3CA -mutant colon cancer cells than for PIK3CA -wild-type colon cancer cells. We measured the anti-proliferative effect of aspirin at physiologic concentrations in seven PIK3CA -mutant and six PIK3CA -wild-type human colon cancer cell lines. After exposure to aspirin, the apoptotic index and cell cycle phase of colon cancer cells were assessed. In addition, the effect of aspirin was examined in parental SW48 cells and SW48 cell clones with individual knock-in PIK3CA mutations of either c.3140A>G (p.H1047R) or c.1633G>A (p.E545K). Aspirin induced greater dose-dependent loss of cell viability in PIK3CA -mutant cells than in PIK3CA -wild-type cells after treatment for 48 and 72 hours. Aspirin treatment also led to higher proportions of apoptotic cells and G0/G1 phase arrest in PIK3CA -mutant cells than in PIK3CA -wild-type cells. Aspirin treatment of isogenic SW48 cells carrying a PIK3CA mutation, either c.3140A>G (p.H1047R) or c.1633G>A (p. E545K), resulted in a more significant loss of cell viability compared to wild-type controls. Our findings indicate that aspirin causes cell cycle arrest, induces apoptosis, and leads to loss of cell viability more profoundly in PIK3CA -mutated colon cancer cells than in PIK3CA -wild-type colon cancer cells. These findings support the use of aspirin to treat patients with PIK3CA -mutant colon cancer.