Abstract
An orthotopic human lung cancer model in nu/nu mice was used to study the effect of an antisense K-ras (AS-K-ras) retroviral construct on tumor growth in vivo. A 2-kilobase genomic AS-K-ras DNA fragment linked to a β-actin promoter was cloned into the LNSX retroviral vector. The recombinant construct was packaged into GP+envAm12 cells and titers greater than 106 colony-forming units/ml were obtained. Irradiated (350 cGy) nu/nu mice were first inoculated intratracheally with 105 H460a human large cell lung carcinoma cells which have a codon 61 mutation of the K-ras oncogene. Three days later they received intratracheal instillation of viral supernatant (5 × 106 colony-forming units/ml) from either LNSX, LNSX-AS-K-ras, LNSX-sense-K-ras producer cells, or medium daily for 3 days. At autopsy, 30 days after tumor cell inoculation, 90% of the control mice had tumors whereas 87% of mice treated with the LNSX-AS-K-ras viral supernatant were free of tumors. The efficacy of the viral supernatant was dose dependent. Intratracheal administration of retroviral LNSX-AS-K-ras supernatant prevents the growth of human lung cancer cells implanted orthotopically in nu/nu mice.
Footnotes
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↵1 This study was partially supported by grants from the National Cancer Institute and NIH (ROI-CA45187) (J. A. R.), National Cancer Institute Training Grant CA-09611 (J. A. R.), gifts to the Division of Surgery from Tenneco and Exxon for the Core Laboratory Facility, the M. D. Anderson Cancer Center Support Grant CA16672, and a grant from the Mathers Foundation.
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↵2 To whom requests for reprints should be addressed, at The University of Texas M. D. Anderson Cancer Center, Department of Thoracic Surgery, Box 109, 1515 Holcombe Blvd., Houston, TX 77030.
- Received February 1, 1993.
- Accepted March 5, 1993.
- ©1993 American Association for Cancer Research.