WDR7 up-regulation upon knocking down of neighboring non-coding RNA using siRNAs encapsulated in polyamidoamine dendrimers

Area of Science:

• Molecular biology
• Nanotechnology
• Cancer research

Background:

• Breast cancer remains a leading cause of mortality in females, necessitating novel therapeutic strategies.
• Long intergenic non-protein coding RNA, a regulator of reprogramming (lincRNA-RoR), is implicated in cancer development and is highly expressed in breast cancer.
• Efficient siRNA delivery systems are critical for successful gene silencing in therapeutic applications.

Purpose of the Study:

• To investigate the potential of fifth-generation PAMAM dendrimer as a nanocarrier for siRNA delivery.
• To achieve gene silencing of lincRNA-RoR in breast cancer cells (MDA-MB 231).
• To evaluate the effect of lincRNA-RoR silencing on the expression of the WDR7 gene, which is involved in apoptosis and cell cycle regulation.

Main Methods:

• PAMAM dendrimer (G5) was complexed with siRNA targeting lincRNA-RoR.
• Gel retardation assay determined the optimal Negative/Positive (N/P) molar charge ratio for siRNA-PAMAM complex formation.
• MTT assay assessed cell viability and determined the IC50 of lincRNA-ROR siRNA (approximately 100 nM).
• Real-time PCR quantified gene expression changes of lincRNA-RoR and WDR7 post-transfection.

Main Results:

• The PAMAM dendrimer effectively complexed with siRNA, forming a suitable nanocarrier.
• Transfection of MDA-MB 231 cells with siRNA targeting lincRNA-RoR led to increased WDR7 gene expression.
• The study identified an IC50 of approximately 100 nM for lincRNA-ROR siRNA.

Conclusions:

• PAMAM dendrimer G5 serves as an effective siRNA delivery system for targeting lincRNA-RoR in breast cancer cells.
• This nanocarrier-siRNA system holds potential for future gene therapy applications in breast cancer treatment.
• The observed increase in WDR7 expression suggests a regulatory relationship influenced by lincRNA-RoR silencing.