Basic Research
Copyright ©The Author(s) 2004. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Gastroenterol. Oct 15, 2004; 10(20): 3011-3015
Published online Oct 15, 2004. doi: 10.3748/wjg.v10.i20.3011
Anti-tumor effect of pEgr-IFNγ gene-radiotherapy in B16 melanoma-bearing mice
Cong-Mei Wu, Xiu-Yi Li, Tian-Hua Huang
Cong-Mei Wu, Tian-Hua Huang, Research Center of Reproductive Medicine, Shantou University Medical College (SUMC), Shantou 515041, Guangdong Province, China
Xiu-Yi Li, The Ministry of Public Health Radiobiology Research Unit of Jilin University, Changchun 130021, Jilin Province, China
Author contributions: All authors contributed equally to the work.
Supported by the National Natural Science Fundation of China, No. 39970229
Correspondence to: Dr. Cong-Mei Wu, Research Center of Reproductive Medicine, Shantou University Medical College, Shantou 515041, Guangdong Province, China.
Telephone: +86-754-8900442 Fax: +86-754-8557562
Received: December 10, 2003
Revised: January 26, 2004
Accepted: March 2, 2004
Published online: October 15, 2004

AIM: To construct a pEgr-IFNγ plasmid and to investigate its expression properties of interferon-γ (INF-γ ) induced by irradiation and the effect of gene-radiotherapy on the growth of melanoma.

METHODS: A recombined plasmid, pEgr-IFNγ , was constructed and transfected into B16 cell line with lipofectamine. The expression properties of pEgr-IFNγ were investigated by ELISA. Then, a B16 melanoma-bearing model was established in mice, and the plasmid was injected into the tumor tissue. The tumor received 20 Gy X-ray irradiation 36 h after injection, and IFN-γ expression was detected from the tumor tissue. A tumor growth curve at different time points was determined.

RESULTS: The eukaryotic expression vector, pEgr-IFNγ , was successfully constructed and transfected into B16 cells. IFN-γ expression was significantly increased in transfected cells after X-ray irradiation in comparison with 0 Gy group (77.73-94.60 pg/mL, P < 0.05-0.001), and was significantly higher at 4 h and 6 h than that of control group after 2 Gy X-ray irradiation (78.90-90.00 pg/mL, P < 0.01-0.001). When the transfected cells were given 2 Gy irradiation 5 times at an interval of 24 h, IFN-γ expression decreased in a time-dependent manner. From d 3 to d 15 after IFNγ gene-radiotherapy, the tumor growth was significantly slower than that after irradiation or gene therapy alone.

CONCLUSION: The anti-tumor effect of pEgr-IFNγ gene-radiotherapy is better than that of genetherapy or radiotherapy alone for melanoma. These results may establish an important experimental basis for gene-radiotherapy of cancer.

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