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@MASTERSTHESIS{DaSilvaAzevedo:177453,
author = {J. Da Silva Azevedo$^*$},
title = {{I}nterconnection between cancer derived small
extracellular vesicles and lipid droplets},
school = {University of Applied Sciences Mannheim},
type = {Bachelorarbeit},
reportid = {DKFZ-2021-02545},
year = {2021},
note = {Corresponding author J. Seco; Bachelorarbeit, University of
Applied Sciences Mannheim, 2021},
abstract = {Small extracellular vesicles (sEVs) are nanovesicles
enclosed by a phospholipid bilayer membrane and are produced
by both healthy and malignant cells. sEVs are responsible
for cell-to-cell communication and have been described as
performing a variety of functions that alter the
physiological or pathological state of the recipient cells.
They can enhance tumor development and progression by
promoting metastasis and angiogenesis via regulation of the
tumoral microenvironment [1]. All these factors have led to
the growing interest in discovering potential future
therapeutic sEV-based approaches, such as drug delivery
vehicles. Increasing evidence indicates that lipid
metabolism influences sEV biological activities such as
biosyn-thesis and interactions with recipient cells. This is
likely related to the fact that lipids that are stored and
released from lipid droplets (LDs) are key components of the
plasma membrane, which can reprogram their fluidity
contributing to an optimal environment for the exchange of
genetic material between cells. The aim of this project was
to investigate the correlation be-tween the release of
tumor-derived sEVs and the biogenesis of lipid droplets. In
order to study this connection, several types of experiments
were used in this bachelor thesis. Previous studies have
shown evidence that tumor acidity and sEV biogenesis
represent common can-cer features [2] along with the
confirmation that X-ray activates sEV biogenesis and
secretion [3]. Therefore, this project was focused to
investigate how the stimulation by these conditions affected
the biogenesis of sEVs and lipid droplets in cancer cell
lines isolated from the breast (MCF7) and lung (H460)
tumors. To this purpose, the two cell lines were cultured in
either a neutral pH (7.4) or an acidic pH (6.5) typical of
tumor environment [4]. Additionally, cell lines were
irradiated with 6 Gy for the radiation experiment. The
number of released sEVs was measured by fluorometric protein
quantification and nanoparticle tracking analysis (NTA). The
expression of sEV protein markers was examined by Western
blotting. Moreover, sEVs were characterized by electron
microscopy. The produced LD number per cell was obtained
through fluorescent confocal microscopy. Furthermore, two
tumor-derived colon cell lines, HT29 and LoVo, were directly
compared for the biogenesis of sEVs and lipid droplets.
Previ-ous studies showed that LoVo has small amounts of LDs
within cells in comparison to HT29 [5]. For this study, Lovo
was perceived as the control and compared to HT29 which has
a natural higher LD accumulation. The experimental setup was
essentially the same with the exception that cells were not
exposed to treatment. The results showed that pH 6.5 and 6
Gy induced a remarkable increase in sEVs and LD production,
and the control groups had the opposite outcome for all
cancer cell lines. The cell lines LoVo and HT29, which were
not in-duced by artificial conditioning, showed an
experimental model which reflects natural settings. The
outcome confirmed the hypothesis that there is an
interconnection in the biogenesis pathway between the two
cell organelles, but further in-depth research is needed to
uncover the mechanistic processes underlying this potential
connection.},
cin = {E041},
cid = {I:(DE-He78)E041-20160331},
pnm = {315 - Bildgebung und Radioonkologie (POF4-315)},
pid = {G:(DE-HGF)POF4-315},
typ = {PUB:(DE-HGF)2},
url = {https://inrepo02.dkfz.de/record/177453},
}