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Expression of the Bax inhibitor-1 gene in pulmonary adenocarcinoma
Version of Record online: 13 DEC 2005
Copyright © 2005 American Cancer Society
Volume 106, Issue 3, pages 648–653, 1 February 2006
How to Cite
Tanaka, R., Ishiyama, T., Uchihara, T., Inadome, Y., Iijima, T., Morishita, Y., Kano, J., Goya, T. and Noguchi, M. (2006), Expression of the Bax inhibitor-1 gene in pulmonary adenocarcinoma. Cancer, 106: 648–653. doi: 10.1002/cncr.21639
- Issue online: 20 JAN 2006
- Version of Record online: 13 DEC 2005
- Manuscript Accepted: 16 AUG 2005
- Manuscript Revised: 12 AUG 2005
- Manuscript Received: 12 MAY 2005
- Ministry of Health, Labor, and Welfare of Japan. Grant Number: 16-1
- bronchioloalveolar carcinoma;
- Bax inhibitor-1
The regulation of programmed cell death, or apoptosis, is crucial for normal development and for the maintenance of homeostasis. It has been shown that the novel antiapoptotic protein Bax inhibitor-1 (BI-1) represents a new type of regulator of cell death pathways controlled by Bcl-2 and Bax.
Surgically resected lung specimens were obtained from 32 patients with peripheral adenocarcinomas, and BI-1 gene expression was examined and compared with expression of the p53, bcl-2 and Bax genes.
Fourteen of 32 tumors (43.8%) were positive for BI-1 gene expression by in situ hybridization. BI-1 gene expression in tumor specimens was significantly higher in adenocarcinomas with bronchioloalveolar carcinoma (BAC) and in adenocarcinomas of mixed subtypes with bronchioloalveolar spreading (14 of 17 tumors; 82.4%) than in carcinomas without it spreading. Patients who had BI-1-positive adenocarcinoma showed a relatively favorable prognosis compared with patients who had BI-1-negative adenocarcinoma. Eleven of 32 tumors (34.4%) were positive for the p53 protein, only 1 of 32 tumors (3.1%) was positive for the Bcl-2 protein, and 26 of 32 tumors (81.3%) were positive for the Bax protein. Protein expressions of p53, Bcl-2, and Bax, as detected by immunohistochemistry, were not associated with BI-1 gene expression.
BI-1 gene expression was restricted to tumor cells with lepidic growth and was a prognostic factor for peripheral-type adenocarcinoma. It is believed that BI-1 gene expression is conserved evolutionarily and may act as a key regulator of the apoptotic pathway in BAC. Cancer 2006. © 2005 American Cancer Society.