Identification of candidate biomarkers for early detection of human lung squamous cell cancer by quantitative proteomics.
To discover novel biomarkers for early detection of human lung squamous cell cancer (LSCC) and explore possible mechanisms of LSCC carcinogenesis, iTRAQ-tagging combined with two dimensional liquid chromatography tandem MS analysis was used to identify differentially expressed proteins in human bronchial epithelial carcinogenic process using laser capture microdissection-purified normal bronchial epithelium (NBE), squamous metaplasia (SM), atypical hyperplasia (AH), carcinoma in situ (CIS) and invasive LSCC. As a result, 102 differentially expressed proteins were identified, and three differential proteins (GSTP1, HSPB1 and CKB) showing progressively expressional changes in the carcinogenic process were selectively validated by Western blotting. Immunohistochemistry was performed to detect the expression of the three proteins in an independent set of paraffin-embedded archival specimens including various stage tissues of bronchial epithelial carcinogenesis, and their ability for early detection of LSCC was evaluated by receiver operating characteristic analysis. The results showed that the combination of the three proteins could perfectly discriminate NBE from preneoplastic lesions (SM, AH and CIS) from invasive LSCC, achieving a sensitivity of 96% and a specificity of 92% in discriminating NBE from preneoplatic lesions, a sensitivity of 100% and a specificity of 98% in discriminating NBE from invasive LSCC, and a sensitivity of 92% and a specificity of 91% in discriminating preneoplastic lesions from invasive LSCC, respectively. Furthermore, we knocked down GSTP1 in immortalized human bronchial epithelial cell line 16HBE cells, and then measured their susceptibility to carcinogen benzo(a)pyrene-induced cell transformation. The results showed that GSTP1 knockdown significantly increased the efficiency of benzo(a)pyrene-induced 16HBE cell transformation. The present data first time show that GSTP1, HSPB1 and CKB are novel potential biomarkers for early detection of LSCC, and GSTP1 down-regulation is involved in human bronchial epithelial carcinogenesis.
Key Laboratory of Cancer Proteomics of Chinese Ministry of Health, Xiangya Hospital, Central South University, Changsha 410008, China.
Gu-Qing
GQ
Zeng
Pang-Fei
PF
Zhang
Xingming
X
Deng
Feng-Lei
FL
Yu
Cui
C
Li
Yan
Y
Xu
Hong
H
Yi
Mao-Yu
MY
Li
Rong
R
Hu
Jian-Hong
JH
Zuo
Xin-Hui
XH
Li
Xun-Xun
XX
Wan
Jia-Quan
JQ
Qu
Qiu-Yan
QY
He
Jian-Huang
JH
Li
Xu
X
Ye
Yu
Y
Chen
Jiao-Yang
JY
Li
Zhi-Qiang
ZQ
Xiao
D000595:Amino Acid Sequence; D014408:Biomarkers, Tumor / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D001980:Bronchi / Q000473:pathology; D002460:Cell Line; D002471:Cell Transformation, Neoplastic / Q000139:chemically induced / Q000378:metabolism; D016000:Cluster Analysis; D052276:Creatine Kinase, BB Form / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D055088:Early Detection of Cancer; D004847:Epithelial Cells / Q000378:metabolism / Q000473:pathology; D015870:Gene Expression; D051549:Glutathione S-Transferase pi / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D055551:HSP27 Heat-Shock Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D006360:Heat-Shock Proteins; D006801:Humans; D061346:Laser Capture Microdissection; D008175:Lung Neoplasms / Q000175:diagnosis / Q000378:metabolism*; D018832:Molecular Chaperones; D008969:Molecular Sequence Data; D018307:Neoplasms, Squamous Cell / Q000175:diagnosis / Q000378:metabolism*; D040901:Proteomics; D012372:ROC Curve; D018709:Statistics, Nonparametric; D053719:Tandem Mass Spectrometry
D014408:Biomarkers, Tumor; D055551:HSP27 Heat-Shock Proteins; C057725:HSPB1 protein, human; D006360:Heat-Shock Proteins; D018832:Molecular Chaperones; C496556:GSTP1 protein, human; D051549:Glutathione S-Transferase pi; D052276:Creatine Kinase, BB Form