Hcc1143

MDA-MB-231, HCC1143, and HCC1937 breast cancer cells were purchased from the Korean Cell Line Bank (Seoul, Korea). Hep3B, Huh7, LCSC, HepG2, and PLC/PRF/5 hepatic cancer cells were a kind gift of Dr. Roberto Gedaly (College of Medicine, University of Kentucky). All other established cell lines were obtained from the American Type Culture Collection (ATCC, Rockville, MD). All cells were cultured according to the manufacturer’s protocol in 5% CO₂ in medium. Cultured cell lines were tested for Mycoplasma contamination routinely every 6 months. Specifically, H23 and H727 cells were tested twice in the course of performing the experiments described within this publication (Supplementary Fig. S4). Inhibitors of UPS pathways used in this study were purchased from commercial vendors: carfilzomib (LC Laboratories, Woburn, MA), bortezomib (ChemieTek, Indianapolis, IN), MG-132 (EMD Millipore, San Diego, CA), PYR-41 (ApexBio, Houston, TX), and P5091 (ApexBio, Houston, TX). The following proteasome fluorogenic substrates were used: Suc-LLVY-AMC (Bachem, Torrance, CA; I-1395), Ac-WLA-AMC (Boston Biochem, Cambridge, MA; S-330), Ac-nLPnLD-AMC (Bachem; I-1850), Ac-RLR-AMC (Boston Biochem; S-290), Ac-ANW-AMC (Boston Biochem; S-320), and Ac-PAL-AMC (Boston Biochem; S-310). Human recombinant Interferon-γ was purchased from eBioscience (San Diego, CA).

The human MCF-7, MDA-MB-231, HCC-1143, HCC-1187, BT20, BT-474, and T47D breast cancer cell lines were purchased from the Korean Cell Line Bank (Seoul, Korea). Cells were cultured in RPMI 1640 media supplemented with 10% heat-inactivated fetal bovine serum (FBS) (Welgene, Korea) and were maintained at 37 °C in a humidified 5% CO₂ atmosphere. Dexamethasone (DXM), Dexamethasone 21-phosphate (DXM-21-P), betamethasone 21-phosphate (BTM-21-P), mifepristone (Sigma Aldrich, St. Louis, MO, USA), Wortmannin, QNZ, MK2206, idasanutlin, AS1842856, XMU-MP-1 and p38 MAPK inhibitor (Selleckchem, Houston, TX, USA) were used in this study.

HCC1143, MDA-MB231, and MDA-MB468 cells were purchased from the Korean Cell Line Bank (Seoul, Republic of Korea). Cells were cultured in the Roswell Park Memorial Institute-1640 medium (Hyclone, Logan, UT, USA), containing 10% heat-inactivated fetal bovine serum (Biowest, Nuaille, France) and 1% penicillin/streptomycin mixture (Gibco), under a humidified atmosphere of 5% CO₂ at 37 °C. Trypsin-EDTA and penicillin/streptomycin were purchased from Gibco BRL (Carlsbad, CA, USA).