Primary tumor xenografts of human lung adeno and squamous cell carcinoma express distinct proteomic signatures.
Nonsmall cell lung carcinoma (NSCLC) accounts for 80% of lung cancers. The most prevalent subtypes of NSCLC are adenocarcinoma (ADC) and squamous cell carcinoma (SCC), which combined account for approximately 90%. Ten resected NSCLC patient tumors (5 ADC and 5 SCC) were directly introduced into severely immune deficient (NOD-SCID) mice, and the resulting xenograft tumors were analyzed by standard histology and immunohistochemistry (IHC) and by proteomics profiling. Mass spectrometry (MS) methods involving 1- and 2-dimensional LC-MS/MS, and multiplexed selective reaction monitoring (SRM, or MRM), were applied to identify and quantify the xenograft proteomes. Hierarchical clustering of protein profiles distinguished between the ADC and SCC subtypes. The differential expression of 178 proteins, including a comprehensive panel of intermediate filament keratin proteins, was found to constitute a distinctive proteomic signature associated with the NSCLC subtypes. Epidermal growth factor receptor (EGFR) was expressed in ADC and SCC xenografts, and EGFR network activation was assessed by phosphotyrosine profiling by Western blot analysis and SRM measurement of EGFR levels, and mutation analysis. A multiplexed SRM/MRM method provided relative quantification of several keratin proteins, EGFR and plakophilin-1 in single LC-MS/MS runs. The protein quantifications by SRM and MS/MS spectral counting were associated with superior dynamic range and reproducibility but were otherwise consistent with orthogonal methods including IHC and Western immuno blotting. These findings illustrate the potential to develop a comprehensive MS-based platform in oncologic pathology for better classification and potentially treatment of NSCLC patients.
Wei
Yuhong
Y
Program in Molecular Structure and Function, Hospital For Sick Children, University Health Network, Ontario Cancer Institute/Princess Margaret Hospital, Toronto, Canada.
Tong
Jiefei
J
Taylor
Paul
P
Strumpf
Dan
D
Ignatchenko
Vladimir
V
Pham
Nhu-An
NA
Yanagawa
Naoki
N
Liu
Geoffrey
G
Jurisica
Igor
I
Shepherd
Frances A
FA
Tsao
Ming-Sound
MS
Kislinger
Thomas
T
Moran
Michael F
MF
D000230:Adenocarcinoma / Q000378:metabolism*; D000818:Animals; D015153:Blotting, Western; D002289:Carcinoma, Non-Small-Cell Lung / Q000378:metabolism*; D002294:Carcinoma, Squamous Cell / Q000378:metabolism*; D002853:Chromatography, Liquid; D016000:Cluster Analysis; D066246:ErbB Receptors / Q000378:metabolism; D006801:Humans; D007150:Immunohistochemistry; D053552:Keratin-7 / Q000378:metabolism; D007633:Keratins / Q000378:metabolism; D051379:Mice; D016688:Mice, Inbred NOD; D009368:Neoplasm Transplantation; D020543:Proteome / Q000032:analysis / Q000378:metabolism*; D015203:Reproducibility of Results; D018709:Statistics, Nonparametric; D053719:Tandem Mass Spectrometry; D014183:Transplantation, Heterologous
C507497:KRT7 protein, human; D053552:Keratin-7; D020543:Proteome; D007633:Keratins; D066246:ErbB Receptors