| Co-Investigator(Kenkyū-buntansha) |
NODA Ichiro Fukui Medical University Medical department Assistant, 医学部, 助手 (60283181)
FUJIEDA Shigeharu Fukui Medical University University Hospital Assistant Professor, 医学部・付属病院, 講師 (30238539)
OHTSUBO Toshio Fukui Medical University University Hospital Assistant Professor, 医学部・付属病院, 講師 (10223877)
SUGIMOTO Chizuru Fukui Medical University University Hospital Assistant, 医学部・付属病院, 助手 (80283183)
YAMADA Takechiyo Fukui Medical University Medical department Assistant, 医学部, 助手 (70283182)
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| Research Abstract |
The chemosensitive rate of 139 cases of head and neck cancer evaluated by ATP method was in the order of 5-FU (27%) >CDDP=CBDCA>MTX>PEP (23%). Therefore, the purpose of this study is to conquer the chemoresistance in combination with gene transfection relating to apoptosis.
1998 : Among the above 5 sensitive drugs, CDDP was employed for the further study, because CDDP is one of the apoptosis-promoting anticancer drugs. Apoptosis by CDDP is regulated with glutathione and with tunicamycin, an inhibitor of glycosylation. A correlation between Bax expression and 5-year survival rate in 57 cases of oropharyngeal squamous cell carcinomas was investigated by immunohistochemical analysis. The cases expressed high apoptosis-promoting gene bax showed significantly better 5-year survival rate.
1999 : Overexpression of p53 showed significantly poor prognosis, while that of Bcl-2 did not show any correlation to it. Correlation between the expressions of p53, Bax, Bcl-2 and apoptotic ratio evaluated b
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y TUNEL staining did not show significant relation, but Bax-positive group showed higher tendency to apoptosis. Since clinical cases highly expressed gene bax showed better prognosis, it was investigated whether the head and neck cancer cell line and CDDP-resistant cell line transfected gene bax by electroporation become more sensitive to CDDP in vitro. The cell lines transfected bax showed significantly higher sensitivity to CDDP.A cancer cell line expressing bcl-2 showed significantly increased CDDP sensitivity by its antisense.
2000 : In vivo study on chemotherapy with some genes promoting apoptosis was carried out.
(1) Anticancer effect of apoptosis-promoting bax gene and its combined effect with CDDP were investigated. Percutaneous transfer of bax gene by particle-mediated delivery (gene gun system) inhibited the growth of mouse CDDP-resistant SCC.Furthermore, a combination with bax gene and CDDP at 3-day intervals markedly inhibited the growth of mouse SCC (p<0.0001).
(2) Anticancer effect of CAD (caspase-activated DNase) and its combined effect with CDDP were investigated. The final DNA fragmentation during apoptosis is controlled by CAD.Although percutaneous transfer of CAD gene alone delivered by the gene gun did not show clear inhibition, a combination with CAD and CDDP significantly inhibited the growth of SCC (p<0.05).
(3) Anticanacer effect of Fas-Fas ligand system was investigated. Since the C3H mouse SCC did not express Fas ligand, this ligand was delivered into the SCC by the same gene gun, and examined the anticancer effect. The growth of SCC transfected Fas ligand was significantly inhibited (p<0.0003), and also significant elongation of the survival time was observed.
Among the above 3 apoptosis-promoting gene transfections, the anticancer effect of bax gene +CDDP seemed to be most effective. Less
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