Abstract 2373: The mechanism study of propranolol in suppressing the genesis and development of gastrointestinal cancer through simultaneously activating autologous CD8+T cells and inhibiting tumor AKT/MAPK pathway

Abstract

Abstract Background: Propranolol may exert the anti-tumor effect in cutaneous and acral melanoma by suppressing AKT and MAPK pathways. Reduced tumor growth following propranolol results from enhanced CD8+T-cell-mediated antitumor immune response. Objective: To clarify the efficacy and mechanism of propranolol in suppressing the genesis and development of gastrointestinal cancer through simultaneously activating autologous CD8+T cells and inhibiting tumor AKT/MAPK pathway. Methods: MTS assay was performed to detect gastrointestinal cancer cells viability, TUNEL staining was used to measure apoptosis in cell lines. IHC was used to detect the expressions of Ki67/p-AKT/p-MEK/p-ERK in tumor tissue. Flow cytometry was performed to explore the immune status of the tumor microenvironment. Clinical study has been performed by Case-control design. Subjects who had not been received neoadjuvant were randomly divided into propranolol or placebo group. Then the primary foci of gastrointestinal cancer subjects were removed by D2 gastrectomy. IHC was used to observe the immune status, tumor proliferation in tumor tissue. Results: We found propranolol reduced cell viability in CT26WT and MFC (mice derived melanoma cell line). Furthermore, propranolol could shrink the tumor size in CT26WT and MFC xenografts (P<0.0001). The frequency of CD3+CD8+ T cells in spleen was significantly elevated in propranolol-treated mice compared with controls. The IFNg and T-bet was significantly increased in the CD8+ T-cell population of propranolol treated mice tumor tissue. Propranolol reduced cell viability and induced apoptosis in AGS, HGC, SW480 and HCT116 cell line. But We did not observe differences in NCM460 cell line (human intestinal epithelial cells). Western Blot showed propranolol reduced the expression of p-AKT, p-MEK and p-ERK. In this prospective clinical study, the frequency of CD8+ was significantly elevated in tumor microenvironment. The expression of p-AKT, p-MEK and p-ERK was decreased in propranolol-treated subjects compared with controls. Conclusion: The potential of propranolol to suppress the genesis and development of gastrointestinal cancer through simultaneously activating autologous CD8+T cells and inhibiting tumor AKT/MAPK pathway. Note: This abstract was not presented at the meeting. Citation Format: Ping Liao. The mechanism study of propranolol in suppressing the genesis and development of gastrointestinal cancer through simultaneously activating autologous CD8+T cells and inhibiting tumor AKT/MAPK pathway [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 2373.