Transcript Circulating exosomal RNA signatures reflect changes in the

Circulating exosomal RNA as a biomarker in melanoma.
Association of Women Surgeons
October 15th, 2016
Genevieve M. Boland, MD, PhD
Assistant Professor, Harvard Medical School
Assistant in Surgery, Massachusetts General Hospital
A lot has changed in a very short period of time.
Molecularly-targeted therapy
Immunotherapy
Circulating Biomarkers in Cancer
CTCs
ctDNA
Exosomes
Proteins
Westphal et al. 2015
Exosomes: Defined By Size
AETHLON MEDICAL INC
Bence Gyorgy et al. Cell. Mol. Life Sci. 2011
Exosomes in Cancer
Bobrie et al, 2011
RNA is Concordant: Cells vs Exosomes
RPMI 7951 Cells
RPMI 7951 Exo
100
90
A375 Cells
A375 Exo
Allele Fraction (%)
80
Sk mel 2 Cells
Sk mel 2 Exo
70
Sk mel 30 Cells
Sk mel 30 Exo
60
MeWo Cells
MeWo Exo
50
40
30
20
10
0
BRAF
V600E
BRAF
V600E
NRAS Q61R
NRAS Q61R
NRAS Q61K
NRAS Q61K
400
p<0.0001
pg BRAF V600E/ng RNA
250
*
300
200
100
0
Normal
200
Pt Number
150
36
280
100
370
50
Melanoma
0
PRE-RESECTION
16000
Electron Microscopy
pg BRAF V600E/ng RNA
Exosome Concentration x107
Patient-Derived Exosome Characterization
POST-RESECTION
Palliative Rsxn
Definitive Rsxn
14000
Pre-resection
Post-resection
12000
10000
Patient Number
8000
6000
4000
2000
0
410
214
356
383
166
Pt Number
RNA is Concordant: Tumor vs Exosomes
Immune/Hematologic
Metabolic
Exosome Profile Reflects Response to aPD1
• Pre- and On-treatment exosomes (n=20) of responders and non-responders
to aPD1
• Statistically significant differences (p<0.05) in pre- to on- change between
responders and non-responders
• 111 genes, including 8 miRNA and markers of immune activation
(e.g. IFN-gamma)
• Expansion cohort and validation ongoing
Exosome RNA Correlates with Tumor Mutations
BRAF
Exosomal RNA
NRAS
Triple WT
NF1
CKIT
Immunotherapy: predictive signature of response
to aPD1
Immunotherapy responsive
Exosomal RNA
Immunotherapy non-responsive
Future Directions
• Examine the use of tumor mutations to assess minimal residual disease and
identify a high-risk subset of surgical patients
• Expand the cohort of immunotherapy patients to validate our immunotherapy
response signature
• Clinical trial of the use of exosomes as a marker of high-risk or residual disease is
surgically resected melanomas
• Clinical trial of exosomal profiling to predict/correlate with response to
immunotherapy
Acknowledgements
• Boland Lab, MGH
–
–
–
–
–
–
Bill Michaud, PhD
Sonia Cohen, MD, PhD
Jessica Cintolo-Gonzalez, MD
Ali Rabi, MD, PhD
Roman Alpatov, PhD
Tabea Moll, MS
• Flaherty Lab, MGH
–
–
–
–
Marc Hammond
Hans Vitzhum
Deborah Plana
Benchun Miao, PhD
• Collaborators:
•
•
•
•
•
•
•
Fisher Lab, CBRC, MGH
David Panka, PhD, BIDMC
Soldano Ferrone, MD, PhD, MGH
Darrell Borger, PhD, MGH
Ryan Corcoran, MD, PhD, MGH
Nir Hacohen, PhD, MGH/Broad Institute
Manolis Kellis, PhD, MIT/Broad Institute
• Larry Zhang
• Alvin Shi, PhD