Investigating the Inhibitory Effect of Silver Nanoparticles on Angiogenesis Gene Expression in the Chick Embryo Chorioallantoic Membrane (CAM) Model: A Potential Tumor Suppressor Approach
Investigating the Inhibitory Effect of Silver Nanoparticles on Angiogenesis Gene Expression in the Chick Embryo Chorioallantoic Membrane (CAM) Model: A Potential Tumor Suppressor Approach
Introduction: Angiogenesis, the process of forming new blood vessels, is a critical driver of tumor growth and metastasis. This process is regulated by factors such as Vascular Endothelial Growth Factor (VEGF) and its receptor KDR (Kinase Insert Domain Receptor). Targeting angiogenesis has become a major focus in cancer therapy, as limiting blood supply to tumors can significantly reduce their growth and spread. Silver nanoparticles (AgNPs), known for their antimicrobial properties, are gaining attention for their potential anticancer effects, particularly in suppressing angiogenesis.
Although AgNPs are widely used in various industries, including agriculture and medicine, there is limited research on their effect on angiogenesis in animal models. This study seeks to fill that gap by investigating the effect of AgNPs on the expression of angiogenesis-related genes in the chick embryo chorioallantoic membrane (CAM), a widely used model for studying blood vessel development. Evaluating the impact of AgNPs on these genes could provide valuable insights into their potential as tumor-suppressing agents.
Hypothesis H0: Silver nanoparticles do not affect the expression of angiogenesis-related genes in the CAM.
Hypothesis H1: Silver nanoparticles affect the expression of angiogenesis-related genes in the CAM.
The objective of this study is to assess the impact of silver nanoparticles on the expression of the VEGF and KDR genes, which are key regulators of angiogenesis, and explore the possibility of AgNPs as an inhibitor of tumor-associated angiogenesis.
Methods: This experimental study was conducted using 14 fertilized chicken eggs obtained from Mahan Hatchery, Kerman, Iran. The eggs were randomly divided into two groups of seven. Group one (treatment group) was injected with 0.2% silver nanoparticles, while group two (control group) received phosphate-buffered saline (PBS). The injections were administered onto the inner shell membrane at 24, 48, and 72-hour intervals. All eggs were incubated vertically in a hatcher (Belderchi Damavand Co. PLC-DQSH) at 37.7°C with 60% relative humidity.
Twenty-four hours after the final injection, the embryos were harvested, and their chorioallantoic membrane (CAM) was collected. RNA was extracted using commercial kits, and cDNA was synthesized. Gene expression of VEGF and KDR was analyzed using Real-Time PCR with specific primers, and GAPDH was used as the reference gene. Statistical analysis was performed using SPSS software, and a T-test was applied to compare gene expression levels between the two groups. A p-value of less than 0.05 was considered statistically significant, confirming the differences in gene expression between the treatment and control groups.
Results: The results revealed a significant decrease in VEGF expression and an increase in KDR expression in the AgNP-treated group compared to the control group. The reduction in VEGF, a primary pro-angiogenic factor, suggests that silver nanoparticles have an inhibitory effect on angiogenesis in the CAM model. The upregulation of KDR may indicate a compensatory response to the decreased VEGF levels, as the receptor attempts to balance the reduction in its ligand. These findings support the hypothesis that AgNPs can modulate the expression of key angiogenesis-related genes, which is essential for limiting tumor-associated vascularization.
Conclusion: This study demonstrates for the first time that silver nanoparticles can significantly influence angiogenesis-related gene expression in the CAM model. The downregulation of VEGF, a key angiogenic factor, suggests that AgNPs may suppress the formation of new blood vessels. Given that angiogenesis is essential for tumor growth, inhibiting this process could be a powerful strategy in cancer therapy. The observed increase in KDR expression may be a compensatory mechanism due to reduced VEGF stimulation, highlighting the complexity of angiogenic regulation in response to nanoparticle exposure.
The potential of AgNPs as an anti-angiogenic agent could contribute to the development of novel cancer therapies aimed at starving tumors of their blood supply. However, further research is needed to elucidate the molecular mechanisms by which AgNPs affect angiogenesis and to confirm these findings in more complex tumor models.
Silver nanoparticles significantly inhibit angiogenesis by downregulating VEGF expression in the CAM model, indicating their potential as an anticancer agent. This study provides important preliminary evidence for the use of AgNPs as a tumor suppressor through angiogenesis inhibition. Future research should focus on validating these results in human tumor models and exploring the broader therapeutic applications of AgNPs in cancer treatment.