OSI-027 Alleviates Oxaliplatin Chemoresistance in Gastric Cancer Cells by Suppressing P-gp Induction

Title:OSI-027 Alleviates Oxaliplatin Chemoresistance in Gastric Cancer Cells by Suppressing P-gp Induction

Volume: 21 Issue: 10

Author(s): En Xu, Hao Zhu, Feng Wang, Ji Miao, Shangce Du, Chang Zheng, Xingzhou Wang, Zijian Li, Feng Xu*, Xuefeng Xia*Wenxian Guan*

Affiliation:

• Department of General Surgery, First People's Hospital of Changshu City, Changshu Hospital Affiliated to Soochow University, Changshu,China

• Department of General Surgery, Nanjing Drum Tower Hospital, The Affiliated Hospital of Nanjing University Medical School, No. 321 Zhongshan Road, Nanjing, 210008,China

• Department of General Surgery, Nanjing Drum Tower Hospital, The Affiliated Hospital of Nanjing University Medical School, No. 321 Zhongshan Road, Nanjing, 210008,China

Keywords: Gastric cancer, OSI-027, oxaliplatin, mTOR, P-gp, multidrug resistance.

Abstract: Gastric cancer is one of the most common malignancies worldwide and the third leading cause of cancer-related death. In the present study, we investigated the potential activity of OSI-027, a potent and selective mammalian target of rapamycin complex 1/2 (mTOR1/2) dual inhibitor, alone or in combination with oxaliplatin against gastric cancer cells in vitro. Cell counting kit-8 assays and EdU staining were performed to examine the proliferation of cancer cells. Cell cycle and apoptosis were detected by flow cytometry. Western blot was used to detect the elements of the mTOR pathway and P-gp in gastric cancer cell lines. OSI-027 inhibited the proliferation of MKN-45 and AGS cells by arresting the cell cycle in the G0/G1 phase. At the molecular level, OSI-027 simultaneously blocked mTORC1 and mTORC2 activation, and resulted in the downregulation of phosphor-Akt, phpspho-p70S6k, phosphor-4EBP1, cyclin D1, and cyclin-dependent kinase4 (CDK4). Additionally, OSI-027 also downregulated P-gp, which enhanced oxaliplatin-induced apoptosis and suppressed multidrug resistance. Moreover, OSI-027 exhibited synergistic cytotoxic effects with oxaliplatin in vitro, while a P-gp siRNA knockdown significantly inhibited the synergistic effect. In summary, our results suggest that dual mTORC1/mTORC2 inhibitors (e.g., OSI-027) should be further investigated as a potentially valuable treatment for gastric cancer.

Cite this article as:

Xu En , Zhu Hao, Wang Feng , Miao Ji , Du Shangce , Zheng Chang , Wang Xingzhou , Li Zijian, Xu Feng *, Xia Xuefeng*, Guan Wenxian*, OSI-027 Alleviates Oxaliplatin Chemoresistance in Gastric Cancer Cells by Suppressing P-gp Induction, Current Molecular Medicine 2021; 21 (10) . https://dx.doi.org/10.2174/1566524020666201120113538