Adenovirus-mediated inhibitor kappaB gene transfer improves the chemosensitivity to anticancer drugs in human lung cancer in vitro and in vivo.
BACKGROUND
Nuclear factor kappaB (NFkappaB) is a transcription factor which is importantly implicated in cancer cell growth. In a previous report, we confirmed that lung cancer cell growth was suppressed significantly by the blockade of NFkappaB function. In this study the combination effect of chemotherapy and inhibition of NFkappaB on the human lung cancer cell line, NCI-H460, in vitro and in vivo was investigated.


METHODS
In the in vitro experiment, 50% of cell growth inhibitory concentrations (IC50) of chemotherapy agents were determined alone or when combined with adenovirus mediated IkappaBalpha gene transfer. Annexin-V/PI stain and caspase 3 activity measurement were used to detect the apoptosis caused by treatment. In the in vivo experiment, the tumor growth suppressive effect of combination treatment was evaluated for tumor-bearing mice. NFkappaB, p53 and VEGF expression in the tumors were also analyzed immunohistologically.


RESULTS
Several chemotherapy agents, including paclitaxel, showed lower IC50s when combined with AdIkappaBalpha infection in vitro. Apoptosis through activation of the caspase 3 pathway was enhanced by the combination treatment. For established NCI-H460 tumors, combined treatment significantly inhibited tumor growth. Immunohistochemical staining showed increased expression of p65 after paclitaxel treatment, while paclitaxel in combination with AdIkappaBalpha intratumoral injection eliminated this expression accompanied by the slightly reduced expression of VEGF, with stable p53 status.


CONCLUSIONS
A combination of chemotherapy and IkappaBalpha could inhibit tumor growth effectively by blocking the expression of NFkappaB and inducing apoptosis. Moreover, it might allow reduction of the dose of chemotherapy agents and provide benefit for clinical application.
Research Institute for Diseases of the Chest, Faculty of Medicine, Kyushu University, 3-1-1 Maidashi Higashi-ku, Fukuoka 812-8582, Japan.
Jian
J
Ni
Koichi
K
Takayama
Rie
R
Ushijima
Naoko
N
Inoshima
Junji
J
Uchino
Taishi
T
Harada
Takahiro
T
Minami
Masafumi
M
Takeshita
Caicun
C
Zhou
Yoichi
Y
Nakanishi
D000256:Adenoviridae / Q000235:genetics; D000818:Animals; D017209:Apoptosis; D053148:Caspase 3 / Q000378:metabolism; D045744:Cell Line, Tumor; D003131:Combined Modality Therapy; D019008:Drug Resistance, Neoplasm; D018014:Gene Transfer Techniques; D016158:Genes, p53; D006801:Humans; D020672:I-kappa B Proteins / Q000235:genetics*; D008175:Lung Neoplasms / Q000628:therapy*; D051379:Mice; D000072000:NF-KappaB Inhibitor alpha; D016328:NF-kappa B / Q000235:genetics* / Q000378:metabolism; D017239:Paclitaxel / Q000494:pharmacology; D014162:Transfection; D042461:Vascular Endothelial Growth Factor A / Q000378:metabolism; D023041:Xenograft Model Antitumor Assays
D020672:I-kappa B Proteins; D016328:NF-kappa B; C000606204:NFKBIA protein, human; C000606205:Nfkbia protein, mouse; C467484:VEGFA protein, human; D042461:Vascular Endothelial Growth Factor A; D000072000:NF-KappaB Inhibitor alpha; D053148:Caspase 3; D017239:Paclitaxel