Characterization of HJ-PI01 as a novel Pim-2 inhibitor that induces apoptosis and autophagic cell death in triple-negative human breast cancer

• Published in: Acta pharmacologica Sinica Vol. 37; no. 9; pp. 1237 - 1250
• Main Authors: Zhao, Yu-qian, Yin, Yi-qiong, Liu, Jie, Wang, Gui-hua, Huang, Jian, Zhu, Ling-juan, Wang, Jin-hui
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 01.09.2016; Nature Publishing Group
• Subjects: Animals; Antineoplastic Agents - chemical synthesis; Antineoplastic Agents - chemistry; Antineoplastic Agents - metabolism; Antineoplastic Agents - pharmacology; Apoptosis - drug effects; Autophagy - drug effects; Biomedical and Life Sciences; Biomedicine; Cell Line, Tumor; Drug Design; Female; Humans; Immunology; Internal Medicine; Mammary Neoplasms, Experimental - drug therapy; Mammary Neoplasms, Experimental - metabolism; Mammary Neoplasms, Experimental - pathology; Medical Microbiology; Mice, Inbred BALB C; Mice, Nude; Molecular Docking Simulation; Molecular Dynamics Simulation; Original; original-article; Oxazines - chemical synthesis; Oxazines - chemistry; Oxazines - metabolism; Oxazines - pharmacology; Pharmacology/Toxicology; Protein-Serine-Threonine Kinases - antagonists & inhibitors; Protein-Serine-Threonine Kinases - genetics; Proto-Oncogene Proteins - antagonists & inhibitors; Proto-Oncogene Proteins - genetics; Triple Negative Breast Neoplasms - drug therapy; Triple Negative Breast Neoplasms - metabolism; Triple Negative Breast Neoplasms - pathology; Vaccine; Xenograft Model Antitumor Assays; lienal polypeptide; HJ-PI01; autophagy; PI003; chlorpromazine; Pim-2 inhibitor; breast cancer; apoptosis; MDA-MB-231 cells
• ISSN: 1671-4083; 1745-7254
• DOI: 10.1038/aps.2016.60

Aim： Pim-2 is a short-lived serine/threonine kinase, which plays a key role in metastasis of breast cancer through persistent activation of STAT3. Although the crystal structure of Pim-2 has been reported, but thus far no specific Pim-2-targeted compounds have been reported. In this study, we identified a novel Pim-2 inhibitor, HJ-PIO1, by in silico analysis and experimental validation. Methods： The protein-protein interaction （PPI） network, chemical synthesis, molecular docking, and molecular dynamics （MD） simulations were used to design and discover the new Pim-2 inhibitor HJ-PIO1. The anti-tumor effects of HJ-PI01 were evaluated in human breast MDA-MB-231, MDA-MB-468, MDA-MB-436, MCF-7 cells in vitro and in MDA-MB-231 xenograft mice, which were treated with HJ-PIO1 （40 mg·kg^1·d^-1, ig） with or without lienal polypeptide （50 mg·kg^1·d^-1, ip） for iO d. The apoptosis/autophage-inducing mechanisms of HJ-PIOi were elucidated using Western blots, immunoblots, flow cytometry, transmission electron microscopy and fluorescence microscopy. Results： Based on the PrePPI network, the potential partners interacting with Pim-2 in regulating apoptosis （160 protein pairs） and autophagy （47 protein pairs） were identified. Based on the structural characteristics of Pim-2, a total of 15 compounds （HJ-PIO1 to HJ-PO15） were synthesized, which showed moderate or remarkable anti-proliferative potency in the human breast cancer cell lines tested. The most effective compound HJ-PIO$ exerted a robust inhibition on MDA-MB-231 cells compared with chlorpromazine and the pan-Pim inhibitor PIOO3. Molecular dynamics （MD） simulation revealed that HJ-PI01 had a good binding score with Pim-2. Moreover, HJ-PIO1 （300 nmol/L） induced death receptor-dependent and mitochondrial apoptosis as well as autophagic death in MDA-MB-231 cells. In MDA-MB-231 xenograft mice, administration of HJ-PIO1 remarkably inhibited the tumor growth and induced tumor cell apoptosis in vivo. Co-administration of HJ-PIO1 with lienal polypeptide could improve the anti-tumor activity of HJ-PIO1 and reduce its toxicity. Conclusion： The newly synthesized compound, HJ-PIO1, can induce death receptor/mitochondrial apoptosis and autophagic cell death by targeting Pim-2 in human breast cancer cells in vitro and in vivo.