Exosomal Heat Shock Proteins as New Players in Tumour Cell-to-Cell Communication

Abstract

Exosomes have recently been proposed as novel elements in the study of intercellular communication in normal and pathological conditions. The biomolecular composition of exosomes reflects the specialized functions of the original cells. Heat shock proteins (Hsps) are a group of chaperone proteins with diverse biological roles. In recent years, many studies have focused on the extracellular roles played by Hsps that appear to be involved in cancer development and immune system stimulation. Hsps localized on the surface of exosomes, secreted by normal and tumour cells, could be key players in intercellular cross-talk, particularly during the course of different diseases, such as cancer. Exosomal Hsps offer significant opportunities for clinical applications, including their use as potential novel biomarkers for the diagnoses or prognoses of different diseases, or for therapeutic applications and drug delivery.

Revelation of mRNAs and proteins in porcine milk exosomes by transcriptomic and proteomic analysis

“…Proteins in exosome were dependented on the specific cell-type [ 26 ], the dendritic cell-derived exosomes contain several cytosolic proteins [ 8 ]. Body fluid derived exosomes CD24, CD9, Annexin-1 and Hsp70 were as positive marker proteins [ 27 ].…”

The involvement of small heat shock protein in chemoresistance in ovarian cancer - in vitro study

“…Based on the molecular size of HSPs, the two main groups of HSPs could be distinguished as a large - HSP110, HSP90, HSP70, HSP60, HSP40 - and the small one HSPB1/HSP27, HSP5/alpha-B Crystallin, HSPB6/HSP20, and HSPB8/HSP22, which are mostly ubiquitously expressed while HSPB2 and HSPB7 are essentially restricted to heart and muscles, HSPB4/alpha-A Crystallin is lens-specific and HSPB9 and HSPB10 are both testis-specific (Rappa et al, 2012[ 47 ]; Treweek et al, 2015[ 59 ]; Kampinga et al, 2009[ 24 ]). Recent studies regarding large HSPs, such as HSP70, HSP90, and HSP60 demonstrated that those proteins localized on the surface of exosomes, secreted by normal and tumor cells, could be key players in intercellular cross-talk (Campanella et al, 2014[ 7 ]; Lancaster and Febbraio, 2005[ 30 ]). Moreover, they interact with survivin, a member of the inhibitor of apoptosis (IAP) protein family, which in consequence increase the survival of cancer cells to applied therapy (Khan et al, 2011[ 25 ]; Gonda et al, 2018[ 19 ]).…”

Serum heat shock protein 90 as a future predictive biomarker in childhood acute lymphoblastic leukemia

“…Several mechanisms have been proposed [ 10 ]. The prevailing view is that cytosolic HSPs are released via Golgi transport vesicles or via exosomes [ 11 ]. Serum HSP90, like other HSPs, was proposed to transmit signals to the immune system by interacting with T lymphocytes and stimulating natural killer (NK) cells.…”