Profiling protein expression in circulating tumour cells using microfluidic western blotting.
Circulating tumour cells (CTCs) are rare tumour cells found in the circulatory system of certain cancer patients. The clinical and functional significance of CTCs is still under investigation. Protein profiling of CTCs would complement the recent advances in enumeration, transcriptomic and genomic characterization of these rare cells and help define their characteristics. Here we describe a microfluidic western blot for an eight-plex protein panel for individual CTCs derived from estrogen receptor-positive (ER+) breast cancer patients. The precision handling and analysis reveals a capacity to assay sparingly available patient-derived CTCs, a biophysical CTC phenotype more lysis-resistant than breast cancer cell lines, a capacity to report protein expression on a per CTC basis and two statistically distinct GAPDH subpopulations within the patient-derived CTCs. Targeted single-CTC proteomics with the capacity for archivable, multiplexed protein analysis offers a unique, complementary taxonomy for understanding CTC biology and ascertaining clinical impact.
Department of Bioengineering, University of California, Berkeley, 308B Stanley Hall, MC 1762, Berkeley, California 94720, USA.
Elly
E
Sinkala
Vortex Biosciences, Inc., Menlo Park, California 94025, USA.|Department of Surgery, Stanford University School of Medicine, Stanford, California 94305, USA.
Elodie
E
Sollier-Christen
Vortex Biosciences, Inc., Menlo Park, California 94025, USA.|Department of Surgery, Stanford University School of Medicine, Stanford, California 94305, USA.
Corinne
C
Renier
Department of Bioengineering, University of California, Berkeley, 308B Stanley Hall, MC 1762, Berkeley, California 94720, USA.|The UC Berkeley-UCSF Graduate Program in Bioengineering, University of California, Berkeley, California 94720, USA.
Elisabet
E
Rosàs-Canyelles
Vortex Biosciences, Inc., Menlo Park, California 94025, USA.|Department of Bioengineering, University of California, Los Angeles, Los Angeles, California 90095, USA.
James
J
Che
Department of Surgery, Stanford University School of Medicine, Stanford, California 94305, USA.
Kyra
K
Heirich
Department of Bioengineering, University of California, Berkeley, 308B Stanley Hall, MC 1762, Berkeley, California 94720, USA.|The UC Berkeley-UCSF Graduate Program in Bioengineering, University of California, Berkeley, California 94720, USA.
Todd A
TA
Duncombe
Department of Bioengineering, University of California, Berkeley, 308B Stanley Hall, MC 1762, Berkeley, California 94720, USA.|The UC Berkeley-UCSF Graduate Program in Bioengineering, University of California, Berkeley, California 94720, USA.
Julea
J
Vlassakis
Department of Bioengineering, University of California, Berkeley, 308B Stanley Hall, MC 1762, Berkeley, California 94720, USA.|The UC Berkeley-UCSF Graduate Program in Bioengineering, University of California, Berkeley, California 94720, USA.
Kevin A
KA
Yamauchi
Department of Statistics, University of California, Berkeley, California 94720, USA.
Haiyan
H
Huang
Department of Surgery, Stanford University School of Medicine, Stanford, California 94305, USA.
Stefanie S
SS
Jeffrey
Department of Bioengineering, University of California, Berkeley, 308B Stanley Hall, MC 1762, Berkeley, California 94720, USA.|The UC Berkeley-UCSF Graduate Program in Bioengineering, University of California, Berkeley, California 94720, USA.
Amy E
0000-0002-6906-2985
AE
Herr
D000328:Adult; D000368:Aged; D015153:Blotting, Western / Q000295:instrumentation / Q000379:methods*; D001943:Breast Neoplasms / Q000175:diagnosis / Q000473:pathology*; D045744:Cell Line, Tumor; D005260:Female; D020869:Gene Expression Profiling / Q000379:methods*; D005987:Glyceraldehyde-3-Phosphate Dehydrogenases / Q000032:analysis; D006801:Humans; D044085:Microfluidics / Q000295:instrumentation / Q000379:methods*; D008875:Middle Aged; D009360:Neoplastic Cells, Circulating / Q000378:metabolism*; D010865:Pilot Projects; D040901:Proteomics / Q000379:methods; D011960:Receptors, Estrogen / Q000378:metabolism; D015203:Reproducibility of Results; D059010:Single-Cell Analysis / Q000295:instrumentation / Q000379:methods
D011960:Receptors, Estrogen; D005987:Glyceraldehyde-3-Phosphate Dehydrogenases