Reduced integrin alpha3 expression as a factor of poor prognosis of patients with adenocarcinoma of the lung.
OBJECTIVE
We investigated the possible association between integrin alpha3 and motility-related protein (MRP-1), cluster of differentiation antigen 9 (CD9) gene expression in non-small-cell lung cancer (NSCLC) and evaluated the prognostic significance of integrin alpha3 expression.


METHODS
We performed a retrospective study of integrin alpha3 and MRP-1/CD9 expression in resected tumor tissues from 151 NSCLC patients using quantitative reverse-transcriptase polymerase chain reaction (RT-PCR) and immunohistochemistry.


RESULTS
The ratio of integrin alpha3/beta-actin expression ranged from 0 to 5.87 (mean was 0.80; median, 0.70). Using the cutoff value of 0.7, there were 78 (52%) integrin alpha3-positive tumors and 73 (48%) tumors with reduced integrin alpha3 expression. The immunohistochemical results agreed well with those of the RT-PCR assays, and 88% had no discrepancy. In case of discrepancy, the results of RT-PCR were used in specimen classification. Integrin alpha3 gene expression was independent from MRP-1/CD9 gene expression. No significant association was found between integrin alpha3 expression and the patients' clinical characteristics. The overall survival rate of patients with integrin alpha3-positive NSCLCs was only slightly better than that of individuals whose tumors had reduced integrin alpha3 expression (55.9% v 47.1%; P = .085). By comparison, the overall survival rate of patients with integrin alpha3-positive adenocarcinomas was strikingly greater than in those whose tumors had reduced gene expression (54.4% v 35.2%; P = .004). Multivariate analysis with the Cox regression model of NSCLC and adenocarcinoma indicated that integrin alpha3 expression correlated better (P = .0188 and P = .0008, respectively) with the overall survival rate than other variables, except lymph node status.


CONCLUSIONS
No significant association was found between integrin alpha3 and MRP-1/CD9 gene expression in lung cancer. However, reduced integrin alpha3 expression is a poor prognosis factor in patients with adenocarcinomas.
Adachi
M
M
Department of Thoracic Surgery, Kitano Hospital, Tazuke Kofukai Medical Research Institute, Osaka, Japan.
Taki
T
T
Huang
C
C
Higashiyama
M
M
Doi
O
O
Tsuji
T
T
Miyake
M
M
D000230:Adenocarcinoma / Q000378:metabolism* / Q000401:mortality / Q000473:pathology; D000328:Adult; D000368:Aged; D015703:Antigens, CD / Q000235:genetics / Q000378:metabolism*; D002289:Carcinoma, Non-Small-Cell Lung / Q000378:metabolism* / Q000401:mortality / Q000473:pathology; D005260:Female; D015870:Gene Expression; D006801:Humans; D007150:Immunohistochemistry; D039422:Integrin alpha3; D016023:Integrins / Q000235:genetics / Q000378:metabolism*; D008175:Lung Neoplasms / Q000378:metabolism* / Q000401:mortality / Q000473:pathology; D008297:Male; D008562:Membrane Glycoproteins; D008875:Middle Aged; D015999:Multivariate Analysis; D016133:Polymerase Chain Reaction; D011379:Prognosis; D016016:Proportional Hazards Models; D012189:Retrospective Studies; D016019:Survival Analysis; D060245:Tetraspanin 29
D015703:Antigens, CD; C554869:CD9 protein, human; D039422:Integrin alpha3; D016023:Integrins; D008562:Membrane Glycoproteins; D060245:Tetraspanin 29