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[Transfer of active oncogenes and promoters into the mouse cell genome]
Abstract:
Different cell DNA's (normal NIH 3T3 DNA; human osteosarcoma cell DNA; human malignant glioma cell DNA with amplified c-Ha-ras) were cotransfected onto NIH 3T3 cells with cloned long terminal repeat (LTR) sequences of Rous sarcoma virus. LTR RSV and normal NIH 3T3 DNA c-fos oncogen expression was detected in tumors induced in nude mice. In the same system human tumour cell DNA with amplified c-Ha-ras gene was used, that to the integration and amplification of LTP sequences with simultaneous maintenance of c-Ha-ras amplification. Nude mouse tumour DNA with integrated LTR sequences was active in successive rounds of transfection.
Insights
Transfection of Rous sarcoma virus long terminal repeat (LTR) sequences into NIH 3T3 cells activated oncogene expression. Integrated LTR sequences in nude mouse tumors remained active in subsequent transfections.
Area of Science:
- Molecular Biology
- Oncogenesis
- Virology
Context:
- Investigating the role of viral long terminal repeats (LTRs) in gene expression and oncogenesis.
- Utilizing NIH 3T3 cells as a model system for transfection studies.
- Examining the behavior of oncogenes in induced tumors.
Purpose:
- To determine if Rous sarcoma virus LTRs can activate oncogene expression (c-fos) in NIH 3T3 cells.
- To assess the integration and amplification of LTR sequences in human tumor DNA within a nude mouse model.
- To evaluate the transfectability of DNA from tumors containing integrated LTR sequences.
Summary:
- Different cell DNAs, including those with amplified c-Ha-ras, were cotransfected with Rous sarcoma virus LTRs into NIH 3T3 cells.
- Tumors induced in nude mice showed expression of LTR RSV and NIH 3T3 DNA c-fos oncogene.
- Human tumor DNA with amplified c-Ha-ras, upon integration and amplification of LTR sequences, maintained c-Ha-ras amplification, and nude mouse tumor DNA with integrated LTRs was active in successive transfections.
Impact:
- Demonstrates the potential of viral LTRs to drive oncogene expression and contribute to tumor formation.
- Highlights the stability and activity of integrated viral sequences in vivo.
- Provides insights into the mechanisms of gene amplification and oncogene activation in cancer research.