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Updated: Jun 12, 2026
Preparation of Cell-lines for Conditional Knockdown of Gene Expression and Measurement of the Knockdown Effects on E4orf4-Induced Cell Death
Published on: October 21, 2012
Knockdown of the Dickkopf 3 gene induces apoptosis in a lung adenocarcinoma
Il Lae Jung1, Hyo Jin Kang, Kug Chan Kim
1Department of Radiation Biology, Environmental Radiation Research Group, Korea Atomic Energy Research Institute, Daejeon 305-600, Korea.
Abstract:
The expression of the Wnt-antagonist Dickkopf gene (DKK) is downregulated in several types of tumors as a consequence of epigenetic DNA modification; four DKK members, DKK1, DKK2, DKK3, and DKK4, have been identified. In this study, we investigated another function of DKK3 in non-small cell lung cancer H460 cells, in which DKK3 was hypermethylated (44%) but still expressed, by interfering with DKK3 expression using DKK3-silencing RNA (SiRNA). We found that knockdown of DKK3 expression by DKK3 SiRNA transfection led to the detachment of H460 cells from the bottom of the culture plate and caused apoptosis. The expression of cyclin-dependent kinases D1 and E were increased by DKK3 knockdown, indicating that cells with blocked DKK3 expression entered the apoptotic pathway. We also found that the intracellular level of reactive oxygen species was higher in cells with blocked DKK3 expression than in normal H460 cells, and levels of p53, p21, and Bax were also increased by the gene knockdown. These results indicate that DKK3 acts as an antiapoptotic molecule by decreasing the intracellular level of reactive oxygen species.
Insights
Dickkopf-3 (DKK3) acts as an anti-apoptotic molecule in non-small cell lung cancer. Silencing DKK3 expression in H460 cells promoted apoptosis by increasing reactive oxygen species.
Area of Science:
- Oncology
- Molecular Biology
- Epigenetics
Background:
- Dickkopf (DKK) gene expression is often downregulated in tumors due to epigenetic DNA modification.
- Four DKK members (DKK1-4) have been identified, with DKK3 playing a role in various cellular processes.
- DKK3 is hypermethylated but still expressed in non-small cell lung cancer (NSCLC) H460 cells.
Purpose of the Study:
- To investigate the function of Dickkopf-3 (DKK3) in non-small cell lung cancer (NSCLC) H460 cells.
- To understand the impact of DKK3 gene silencing on NSCLC cell behavior and apoptosis.
- To explore the molecular mechanisms underlying DKK3's role in apoptosis and reactive oxygen species regulation.
Main Methods:
- Utilized DKK3-silencing RNA (siRNA) to interfere with DKK3 expression in H460 cells.
- Observed cell detachment and apoptosis following DKK3 knockdown.
- Quantified intracellular reactive oxygen species (ROS) levels.
- Assessed the expression of apoptosis-related proteins including p53, p21, and Bax, as well as cyclin-dependent kinases D1 and E.
Main Results:
- Knockdown of DKK3 expression led to H460 cell detachment and induced apoptosis.
- DKK3 silencing resulted in increased intracellular reactive oxygen species (ROS) levels.
- Expression of cyclin-dependent kinases D1 and E, p53, p21, and Bax was elevated post-DKK3 knockdown.
- These molecular changes indicate entry into the apoptotic pathway.
Conclusions:
- DKK3 functions as an anti-apoptotic molecule in non-small cell lung cancer.
- DKK3 exerts its anti-apoptotic effect by reducing intracellular reactive oxygen species (ROS).
- Targeting DKK3 may represent a potential therapeutic strategy for NSCLC.
