Expression of the Bax inhibitor-1 gene in pulmonary adenocarcinoma.

Abstract

BACKGROUND:

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.

METHODS:

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.

RESULTS:

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.

CONCLUSIONS:

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.

• Authors: Ryota Tanaka, Tadashi Ishiyama, Teruhito Uchihara, Yukinori Inadome, Tatsuo Iijima, Yukio Morishita, Junko Kano, Tomoyuki Goya, Masayuki Noguchi
• Journal: Cancer (Cancer) Vol. 106 Issue 3 Pg. 648-53 (Feb 01 2006) ISSN: 0008-543X [Print] United States
• PMID: 16353209 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)
• Copyright: Copyright (c) 2005 American Cancer Society.

Chemical References

• Apoptosis Regulatory Proteins
• Membrane Proteins
• Proteins
• TMBIM6 protein, human

Topics

• Adenocarcinoma (genetics, pathology)
• Aged
• Apoptosis (genetics)
• Apoptosis Regulatory Proteins
• Female
• Gene Expression Profiling
• Humans
• Lung Neoplasms (genetics, pathology)
• Male
• Membrane Proteins
• Middle Aged
• Prognosis
• Proteins (analysis, genetics)