Open AccessPRDM14 directly interacts with heat shock proteins HSP90α and glucose‐regulated protein 78
Author(s) -
Moriya Chiharu,
Taniguchi Hiroaki,
Nagatoishi Satoru,
Igarashi Hisayoshi,
Tsumoto Kouhei,
Imai Kohzoh
Publication year - 2018
Publication title -
cancer science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.035
H-Index - 141
eISSN - 1349-7006
pISSN - 1347-9032
DOI - 10.1111/cas.13458
Subject(s) - heat shock protein , cancer research , luciferase , carcinogenesis , cold shock domain , gene knockdown , breast cancer , cancer , estrogen receptor , population , chemistry , biology , cell culture , medicine , transfection , gene , biochemistry , rna , genetics , environmental health
PRDM 14 is overexpressed in various cancers and can regulate cancer phenotype under certain conditions. Inhibiting PRDM 14 expression in breast and pancreatic cancers has been reported to reduce cancer stem‐like phenotypes, which are associated with aggressive tumor properties. Therefore, PRDM 14 is considered a promising target for cancer therapy. To develop a pharmaceutical treatment, the mechanism and interacting partners of PRDM 14 need to be clarified. Here, we identified the proteins interacting with PRDM 14 in triple‐negative breast cancer ( TNBC ) cells, which do not express the three most common types of receptor (estrogen receptors, progesterone receptors, and HER 2). We obtained 13 candidates that were pulled down with PRDM 14 in TNBC HCC 1937 cells and identified them by mass spectrometry. Two candidates—glucose‐regulated protein 78 ( GRP 78) and heat shock protein 90‐α ( HSP 90α)—were confirmed in immunoprecipitation assay in two TNBC cell lines ( HCC 1937 and MDA ‐ MB 231). Surface plasmon resonance analysis using GST ‐ PRDM 14 showed that these two proteins directly interacted with PRDM 14 and that the interactions required the C‐terminal region of PRDM 14, which includes zinc finger motifs. We also confirmed the interactions in living cells by NanoLuc luciferase‐based bioluminescence resonance energy transfer (Nano BRET ) assay. Moreover, HSP 90 inhibitors (17 DMAG and HSP 990) significantly decreased breast cancer stem‐like CD 24 − CD 44 + and side population ( SP ) cells in HCC 1937 cells, but not in PRDM 14 knockdown HCC 1937 cells. The combination of the GRP 78 inhibitor HA 15 and PRDM 14 knockdown significantly decreased cell proliferation and SP cell number in HCC 1937 cells. These results suggest that HSP 90α and GRP 78 interact with PRDM 14 and participate in cancer regulation.