Single-cell proteomic chip for profiling intracellular signaling pathways in single tumor cells.
We describe a microchip designed to quantify the levels of a dozen cytoplasmic and membrane proteins from single cells. We use the platform to assess protein-protein interactions associated with the EGF-receptor-mediated PI3K signaling pathway. Single-cell sensitivity is achieved by isolating a defined number of cells (n = 0-5) in 2 nL volume chambers, each of which is patterned with two copies of a miniature antibody array. The cells are lysed on-chip, and the levels of released proteins are assayed using the antibody arrays. We investigate three isogenic cell lines representing the cancer glioblastoma multiforme, at the basal level, under EGF stimulation, and under erlotinib inhibition plus EGF stimulation. The measured protein abundances are consistent with previous work, and single-cell analysis uniquely reveals single-cell heterogeneity, and different types and strengths of protein-protein interactions. This platform helps provide a comprehensive picture of altered signal transduction networks in tumor cells and provides insight into the effect of targeted therapies on protein signaling networks.
Nanosystems Biology Cancer Center, Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, CA 91125, USA.
Qihui
Q
Shi
Lidong
L
Qin
Wei
W
Wei
Feng
F
Geng
Rong
R
Fan
Young Shik
YS
Shin
Deliang
D
Guo
Leroy
L
Hood
Paul S
PS
Mischel
James R
JR
Heath
D045744:Cell Line, Tumor; D000069347:Erlotinib Hydrochloride; D005453:Fluorescence; D006801:Humans; D047908:Intracellular Signaling Peptides and Proteins / Q000235:genetics* / Q000378:metabolism; D040081:Protein Array Analysis / Q000379:methods*; D040901:Proteomics / Q000379:methods*; D011799:Quinazolines; D015398:Signal Transduction / Q000235:genetics*
D047908:Intracellular Signaling Peptides and Proteins; D011799:Quinazolines; D000069347:Erlotinib Hydrochloride