Analysis of eHsp90 Regulation of Secreted Exosomes from Cancer Cells

Juan Felipe ToscanoMcCready Lab

Department of Natural Science, Assumption College

Samarasinghe, 2013

• Under stress, cancer cells release a high amount of micro-vesicles named exosomes

• Exosomes have a high amount of proteins that could potentially enhance cancer invasiveness and metastasis

• Exosomes could be a way for cells to communicate and exchange genetic information outside the cell

• One of the most abundant proteins identified inside the exosomes was the Heat shock protein 90 (Hsp90)

• Hsp90 is an important intracellular protein that activates many proteins

• eHsp90 is secreted from tumor cells via exosomes

• It activates pro-invasive proteins that contribute to cellular aggressiveness and motility

McCready et al. 2010

Hypothesis

We hypothesize that eHsp90 regulates exosome secretion from cancer cells

MDA-MB-231

Media

Depleted media

Determine protein concentration

Western Blot

6050403020

80110160260

15

Contr

ol 1 H

sp90

Contr

ol 2 H

sp90

Hsp90control Bands

Western blot

ExosomesDepleted

of exosomes

Hsp90

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15000

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25000

Exosome Media

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Hsp90 concentration

MDA-MB-231

100nM STA-12-7191Untreated

DMSO 10nM STA-12-7191

Depleted media

Determine protein concentration

Western Blot

Depleted media

Depleted media

Depleted media

6050403020

80110160260

15

Contr

ol 1 H

sp90

Contr

ol 2 H

sp90

Hsp90control Bands

untreated DMSO10nM STA-12-7191

100nM STA-12-7191

Hsp90

Depleted of exosomes

Western blot from Drug treatment

Hsp90 concentration in media depleted of exosomes

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10

20

30

40

50

Untreated DMSO 10nM STA-7191 100nM STA-7191

Arbi

trar

y un

its

6050403020

80110160260

15

Contr

ol 1 H

sp90

Contr

ol 2 H

sp90

Hsp90control Bands

Untreated DMSO

10nM STA-12-7191

100nM STA-12-7191

Western blot from Drug treatment

Hsp90

Exosomes

Hsp90 concentration in Exosomes isolated

0

10

20

30

40

50

Untreated DMSO 10nM STA-7191 100nM STA-7191

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Inhibiting eHsp90

• eHsp90 levels remain high in exosome fraction

• eHsp90 levels decrease in media depleted of exosomes

Conclusions• Data suggest that eHsp90 may be important

for protein release from exosomes.

Untreated Cells

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Treated cells

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Acknowledgements

• I want to thank Professor Jessica McCready for giving me the opportunity to work in her lab.

• I would also like to thank the Jay Lab members at Tufts University for giving me the opportunity to continue this research that I started with them back in 2014