MP92-17 NELFINAVIR INDUCES ENDOPLASMIC RETICULUM STRESS AND SENSITIZES RENAL CANCER CELLS TO TUMOR NECROSIS FACTOR-RELATED APOPTOSIS-INDUCING LIGAND

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You have accessJournal of UrologyKidney Cancer: Basic Research & Pathophysiology III1 Apr 2016MP92-17 NELFINAVIR INDUCES ENDOPLASMIC RETICULUM STRESS AND SENSITIZES RENAL CANCER CELLS TO TUMOR NECROSIS FACTOR-RELATED APOPTOSIS-INDUCING LIGAND Kazuki Okubo, Akinori Sato, Takako Asano, Makoto Isono, Keiichi Ito, and Tomohiko Asano Kazuki OkuboKazuki Okubo More articles by this author , Akinori SatoAkinori Sato More articles by this author , Takako AsanoTakako Asano More articles by this author , Makoto IsonoMakoto Isono More articles by this author , Keiichi ItoKeiichi Ito More articles by this author , and Tomohiko AsanoTomohiko Asano More articles by this author View All Author Informationhttps://doi.org/10.1016/j.juro.2016.02.2650AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookTwitterLinked InEmail INTRODUCTION AND OBJECTIVES Drug repositioning is a powerful strategy for finding new anticancer drugs. The human immunodeficiency virus protease inhibitor nelfinavir acts against cancer by suppressing molecular chaperones, leading to the accumulation of unfolded proteins and thereby causing endoplasmic reticulum (ER) stress. In the present study we investigated nelfinavir's antineoplastic activity against renal cancer cells and its ability to sensitize them to tumor necrosis factor-related apoptosis-inducing ligand (TRAIL). METHODS After renal cancer cells (Caki-2, 769-P, 786-O) and renal proximal tubule epithelial cells (RPTECs) were treated with clinically feasible concentrations of nelfinavir (5-20 µM), their viability and clonogenicity were assessed by MTS assay and colony formation assay. Apoptosis was evaluated by annexin-V assay. Cell cycle analysis was done using flow cytometry. ER stress and autophagy were evaluated by western blotting, as was the expression of cyclin D1 and TRAIL death receptor (DR) 5. Aggresome formation was evaluated using fluorescence microscopy. RESULTS Nelfinavir induced apoptosis and inhibited renal cancer growth in a dose-dependent fashion. It also suppressed colony formation significantly (P = 0.001), but it inhibited the growth of RPTECs slightly. Nelfinavir decreased the expression of cyclin D1 and decreased the cells in the S phase, increasing the sub-G1 fraction. As expected, nelfinavir induced ER stress evidenced by increased expression of glucose-regulated protein 78 and endoplasmic reticulum resident protein 44. The nelfinavir-treated cancer cells displayed massive cytoplasmic vacuolization, confirming that nelfinavir induced ER stress. It also induced autophagy evidenced by the increased expression of the autophagy marker light chain 3-II, and this autophagy followed the accumulation and aggregation of unfolded proteins (aggresome formation). Furthermore, the nelfinavir-induced ER stress increased the expression of DR5 and thereby sensitized the cancer cells to TRAIL. This TRAIL-induced apoptosis was blocked by human recombinant DR5/Fc chimeric protein, confirming that it was mediated by DR5. CONCLUSIONS Nelfinavir inhibits renal cancer growth effectively by inducing ER stress. Increased DR5 expression is also an important mechanism of action. © 2016FiguresReferencesRelatedDetails Volume 195Issue 4SApril 2016Page: e1168 Advertisement Copyright & Permissions© 2016MetricsAuthor Information Kazuki Okubo More articles by this author Akinori Sato More articles by this author Takako Asano More articles by this author Makoto Isono More articles by this author Keiichi Ito More articles by this author Tomohiko Asano More articles by this author Expand All Advertisement Advertisement PDF downloadLoading ...