| Budget Amount *help |
¥3,500,000 (Direct Cost: ¥3,500,000)
Fiscal Year 2003: ¥1,300,000 (Direct Cost: ¥1,300,000)
Fiscal Year 2002: ¥2,200,000 (Direct Cost: ¥2,200,000)
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| Research Abstract |
To elucidate the regulatory mechanisms for wound-related geneexpression at the invasive front of lung adenocarcinomas, the following investigations were performed:
(1)The promoter region of laminin-5 gamma2 gene spanning the 1.5kb region upstream of the transcription initiation site was PCR amplified and cloned into pGL3-luc vector. Preliminary experiment confirmed that this region controls the upregulation of laminin-5 gamma2 gene after stimulation with TGF-alpha. The results of this study showed that (a)This promoter activity is induced 20 fold by co-transfection of active MEK expression vector, whereas it is inhibited by pharmacologic MEK inhibitor: (2)The activity of laminin-5 gamma2 promoter is strongly repressed by the wild-type, but not by the mutant type, p53 gene. Subsequent analyses with serial deletion mutant of the laminin-5 promoters revealed that this regulatory mechanism is retained in promoters upstream of 0.5 kb transcription initiation site.
(2)To investigate the activation of wound-related signal transduction pathways in lung adenocarcinoma tissues, immunohistochemical analyses were performed using phospho-specific antibodies. The results showed that c-met is activated in 4/20 cases, erk in 15/20 cases, jnk in 3/20 cases, and p38 in 7/20 cases. As regards NF-kappaB, p65 and p50 subunits were positive in all the 20 cases examined, with certain populations of cancer cells showing nuclear immunoreactivities for these two proteins.
(3)The activation of c-met was further analyses in a total of 78cases of resected lung adenocarcinomas. The activation of the c-met receptor was detected in 14/78 cases (17.9%). Active form of c-met was localized at the surface of cancer cells, especially in adenocarcinomas of well differentiated type. Similar localized was observed in several lung adenocarcinoma cell lines.
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