Journal Article

Cell Stress Induced Stressome Release Including Damaged Membrane Vesicles and Extracellular HSP90 by Prostate Cancer Cells

Tran, Manh Tien, Eguchi, Takanori, Okusha, Yuka, Lang, Benjamin J., Matsumoto, Masaki, Okamoto, Kuniaki, Ono, Kisho, Sogawa, Chiharu, Calderwood, Stuart K.

2020

Overview

Tumor cells exhibit therapeutic stress resistance-associated secretory phenotype involving extracellular vesicles (EVs) such as oncosomes and heat shock proteins (HSPs). Such a secretory phenotype occurs in response to cell stress and cancer therapeutics. HSPs are stress-responsive molecular chaperones promoting proper protein folding, while also being released from cells with EVs as well as a soluble form known as alarmins. We have here investigated the secretory phenotype of castration-resistant prostate cancer (CRPC) cells using proteome analysis. We have also examined the roles of the key co-chaperone CDC37 in the release of EV proteins including CD9 and epithelial-to-mesenchymal transition (EMT), a key event in tumor progression. EVs derived from CRPC cells promoted EMT in normal prostate epithelial cells. Some HSP family members and their potential receptor CD91/LRP1 were enriched at high levels in CRPC cell-derived EVs among over 700 other protein types found by mass spectrometry. The small EVs (30–200 nm in size) were released even in a non-heated condition from the prostate cancer cells, whereas the EMT-coupled release of EVs (200–500 nm) and damaged membrane vesicles with associated HSP90α was increased after heat shock stress (HSS). GAPDH and lactate dehydrogenase, a marker of membrane leakage/damage, were also found in conditioned media upon HSS. During this stress response, the intracellular chaperone CDC37 was transcriptionally induced by heat shock factor 1 (HSF1), which activated the CDC37 core promoter, containing an interspecies conserved heat shock element. In contrast, knockdown of CDC37 decreased EMT-coupled release of CD9-containing vesicles. Triple siRNA targeting CDC37, HSP90α, and HSP90β was required for efficient reduction of this chaperone trio and to reduce tumorigenicity of the CRPC cells in vivo. Taken together, we define “stressome” as cellular stress-induced all secretion products, including EVs (200–500 nm), membrane-damaged vesicles and remnants, and extracellular HSP90 and GAPDH. Our data also indicated that CDC37 is crucial for the release of vesicular proteins and tumor progression in prostate cancer.

• Publisher: MDPI AG,MDPI
• Subject: Androgens / Animals / Base Sequence / Cancer therapies / Carcinogenesis - metabolism / Carcinogenesis - pathology / Castration / CD9 antigen / Cell Cycle Proteins - genetics / Cell Cycle Proteins - metabolism / Cell division / cell division control 37 (cdc37) / Cell Line, Tumor / Cell Shape / cell stress response / Chaperones / Chaperonins - genetics / Chaperonins - metabolism / Cyclin-dependent kinases / Deoxyribonucleic acid / DNA / DNA damage / ectosome / Epithelial cells / Epithelial Cells - metabolism / Epithelial Cells - pathology / Epithelial-Mesenchymal Transition / exosome / extracellular vesicle / Extracellular vesicles / Extracellular Vesicles - metabolism / Extracellular Vesicles - ultrastructure / Gene Expression Regulation, Neoplastic / Glyceraldehyde-3-phosphate dehydrogenase / Heat shock factors / heat shock protein 90 (hsp90) / Heat shock proteins / Heat Shock Transcription Factors - metabolism / Heat-Shock Response / HSF1 protein / HSP90 Heat-Shock Proteins - metabolism / Hsp90 protein / Humans / Hypoxia / Kinases / L-Lactate dehydrogenase / L-Lactate Dehydrogenase - metabolism / Lactic acid / Lipids / Male / Mass spectroscopy / Membrane vesicles / Mesenchyme / Metastasis / Mice, SCID / Phenotypes / Promoter Regions, Genetic - genetics / Prostate cancer / Prostatic Neoplasms - genetics / Prostatic Neoplasms - metabolism / Prostatic Neoplasms - pathology / Prostatic Neoplasms, Castration-Resistant - metabolism / Prostatic Neoplasms, Castration-Resistant - pathology / Protein folding / Proteins / Proteome - metabolism / Proteomes / Secretory vesicles / siRNA / Stress, Physiological / stressome / Transcription / Tumor cells / Tumorigenicity