Osteopontin but not osteonectin messenger RNA expression is a prognostic marker in curatively resected non-small cell lung cancer.
OBJECTIVE
The purpose of this study was to better define the role of osteopontin (OPN) and osteonectin [also known as secreted protein acidic and rich in cysteine (SPARC)] in lung tumorigenesis by comparing the expressions of these genes in lung tumor tissue and matched normal tissue and by determining the prognostic significance of the gene expressions.


METHODS
Quantitative real-time reverse transcription-PCR was used to analyze OPN and SPARC mRNA expression in normal lung tissue and matching tumor samples from 82 patients with non-small cell lung cancer. Gene expression data for each patient were matched to survival data.


RESULTS
The overall median mRNA expression level of OPN was about 20-fold higher in tumor tissues than in matching normal lung tissues (P < 0.001), whereas SPARC gene expression was not significantly different in both tissue types. Forty of 82 patients had high (>or=4.1) intratumoral OPN expression, and 15 of 82 patients had high (>or15.5) SPARC expression. High OPN expression in the tumor tissue was associated with inferior survival (P = 0.014), whereas high SPARC expression showed a trend toward longer survival (P = 0.095). The impact of high OPN and low SPARC expression on patient survival was additive (P = 0.001).


CONCLUSIONS
The large increase in OPN expression in tumors compared with normal tissue and its association with survival suggest a role for OPN in lung tumorigenesis.
Schneider
Sylke
S
Department of Molecular Biology, University of Southern California Keck School of Medicine, Los Angeles, California 90033, USA.
Yochim
JiMin
J
Brabender
Jan
J
Uchida
Kazumi
K
Danenberg
Kathleen D
KD
Metzger
Ralf
R
Schneider
Paul M
PM
Salonga
Dennis
D
Hölscher
Arnulf H
AH
Danenberg
Peter V
PV
D000368:Aged; D001483:Base Sequence; D002289:Carcinoma, Non-Small-Cell Lung / Q000235:genetics / Q000401:mortality / Q000601:surgery*; D017931:DNA Primers; D005260:Female; D015972:Gene Expression Regulation, Neoplastic / Q000235:genetics; D006801:Humans; D008168:Lung / Q000473:pathology; D008175:Lung Neoplasms / Q000235:genetics / Q000401:mortality / Q000601:surgery*; D008297:Male; D008875:Middle Aged; D009362:Neoplasm Metastasis / Q000235:genetics; D009367:Neoplasm Staging; D015676:Osteonectin / Q000235:genetics*; D053495:Osteopontin; D011379:Prognosis; D012333:RNA, Messenger / Q000032:analysis / Q000235:genetics*; D020133:Reverse Transcriptase Polymerase Chain Reaction / Q000379:methods; D012795:Sialoglycoproteins / Q000235:genetics*; D016019:Survival Analysis
D017931:DNA Primers; D015676:Osteonectin; D012333:RNA, Messenger; C506895:SPP1 protein, human; D012795:Sialoglycoproteins; D053495:Osteopontin