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Updated: May 1, 2026
DNA Vector-based RNA Interference to Study Gene Function in Cancer
Published on: June 4, 2012
[Construction and expression of nm23-H1 gene with different enzyme activities and resistant specific shRNA in
Zhansheng Lu1, Lili Guo1, Lin Li1
1Tianjin Key Laboratory of Lung Cancer Metastasis and Tumor Microenvironment, Tianjin Lung Cancer Institute, Tianjin Medical University General Hospital, Tianjin 300052, China.
Background And Objective:
It has been proven that nm23-H1 gene was a tumor metastatic suppressor gene. However, it’s molecular mechanism of suppressing metastasis remains unexplored. There is a closely relationship between the abnormality of stucturs and functions of nm23-H1 gene, and cancer invasion and metastasis. We have constructed the vector with nm23-H1-shRNA and the vector with nm23-H1cDNA resistant to the specific shRNA. So, we plan to construct shRNA-resistant eukaryotic expression vector of nm23-H1 gene by site-directed mutagenesis, rescue experiment was performed to verify the nm23-H1 gene expression, and to provide basement for studying the biochemical mechanisms of nm23-H1 gene.
Methods:
Site-directed mutagenesis of nm23-H1 gene was performed by overlap extension PCR method. Pure plasmid containing gene of nm23-H1 (shRNA-resistant) was prepared. The desired five mutations were constructed and cloned into the eukaryotic vector pcDNA3.1Hygro(+). The human lung adenocarcinoma cell A549/nm23-H1-shRNA (stable nm23-H1 gene silencing) was transfected with the five mutants, and the expression of the mutant proteins was determined by Western blot.
Results:
Five eukaryotic expression vectors (shRNA-resistant) of nm23-H1, nm23-H1S44A, nm23-H1(P96S), nm23-H1(H118F), nm23-H1(S120G), nm23-H1(P96S-S120G), were successfully constructed. The results of DNA sequencing confirmed that the base sequences of the genes were completely concordant with experiment design. The expression of nm23-H1 mutant proteins was verified by Western blot.
Conclusion:
Five eukaryotic expression vectors (shRNA-resistant) of nm23-H1 gene were successfully constructed, and the mutant proteins were verified. The site-directed mutagenesis technical of overlap extension PCR is a efficient, simple and economical method.
Insights
Researchers successfully created shRNA-resistant nm23-H1 gene vectors to study its role in suppressing tumor metastasis. This advancement provides a foundation for understanding the nm23-H1 gene
Area of Science:
- Molecular Biology
- Cancer Research
- Genetics
Context:
- The nm23-H1 gene is recognized as a tumor metastasis suppressor.
- The precise molecular mechanisms by which nm23-H1 suppresses metastasis are not fully understood.
- Abnormalities in nm23-H1 structure and function are linked to cancer invasion and metastasis.
Purpose:
- To construct shRNA-resistant eukaryotic expression vectors for the nm23-H1 gene using site-directed mutagenesis.
- To perform rescue experiments to verify nm23-H1 gene expression.
- To establish a basis for studying the biochemical mechanisms of nm23-H1 gene function in metastasis suppression.
Summary:
- Site-directed mutagenesis via overlap extension PCR was employed to create five distinct shRNA-resistant nm23-H1 gene mutants.
- These mutants were cloned into the pcDNA3.1Hygro(+) vector and transfected into A549/nm23-H1-shRNA lung adenocarcinoma cells.
- Western blot analysis confirmed the successful expression of the nm23-H1 mutant proteins.
Impact:
- Successfully generated and verified shRNA-resistant nm23-H1 eukaryotic expression vectors and their mutant proteins.
- Demonstrated the efficiency, simplicity, and cost-effectiveness of the overlap extension PCR method for site-directed mutagenesis.
- Provides essential tools for future research into the biochemical pathways underlying nm23-H1's metastasis-suppressive functions.
