BRCA-siRNA Fusion Complex for CD47-Targeted PARP Sensitization
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing PARP inhibitors show lower therapeutic efficacy in cancers with wild-type BRCA genes, necessitating a more effective delivery system for BRCA-specific siRNA to enhance cancer cell sensitivity and treatment outcomes.
Innovation Solution
A fusion protein-siRNA complex is developed, where SIRPα protein and a linker peptide are covalently linked to BRCA-specific siRNA, enabling targeted delivery to cancer cells overexpressing CD47, thereby enhancing the sensitivity of cancer cells to PARP inhibitors.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If PARP inhibitors are used to treat cancers with wild-type BRCA genes, then the treatment can be administered, but the anticancer efficacy is low
Solution Approach 1:
The patent applies preliminary action by using siRNA to knock down BRCA gene expression before administering PARP inhibitors. This pre-treatment creates BRCA-deficient cancer cells that are highly sensitive to PARP inhibition, thereby enhancing the efficacy of subsequent PARP inhibitor treatment in wild-type BRCA cancers
Solution Approach 2:
The patent changes the parameter of BRCA gene expression level by introducing siRNA that specifically targets and reduces BRCA mRNA translation. This parameter change transforms wild-type BRCA cancer cells into BRCA-deficient cells, making them responsive to PARP inhibitors
2Reliability
If siRNA is used to knock down BRCA gene expression, then sensitivity to PARP inhibitors is improved, but delivery into target cells is inefficient
Solution Approach 1:
The patent uses a cell-penetrating peptide (CPP) as an intermediary carrier to facilitate the delivery of siRNA into cancer cells. The CPP acts as a mediator that transports the negatively charged siRNA across the cell membrane barrier, enabling efficient intracellular delivery without requiring complex delivery systems
Solution Approach 2:
The patent creates a composite structure by conjugating siRNA with cell-penetrating peptide. This composite material combines the gene-silencing function of siRNA with the cell-penetration capability of CPP, achieving both efficient delivery and effective gene knockdown
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The fusion protein-siRNA complex effectively delivers BRCA-specific siRNA to cancer cells, increasing the sensitivity of cancer cells to PARP inhibitors, particularly in cancers with wild-type BRCA genes, and enhances the anticancer effect of PARP inhibitors.
Implementation Method 1
small interfering RNA (siRNA) is a small RNA fragment of 18 to 27 nt in size produced by cleavage of double-stranded RNA by a Dicer, and may be used by binding specifically to mRNA having a complementary sequence to inhibit the expression of the mRNA
Implementation Method 2
CD47 is a cell membrane protein that interacts with SIRPα to protect cells from macrophages. The cancer cells overexpress CD47 to evade the innate immune system
Implementation Method 3
Cancer cells with BRCA1/2 mutation are known to repair DNA by a base excision repair (BER) mechanism, and a PARP protein is essentially required for activation of a BER pathway
Implementation Method 4
Olaparib, Veliparib, Niraparib, and Rucaparib have been approved as PARP inhibitors for the treatment of breast and ovarian cancers with BRCA mutations
Data Source
Figure 1
Figure 2A~2B
Figure 3A~3C
AI summary
Provided is BRCA-specific siRNA for enhancing the sensitivity of cancer cells to PARP inhibitors. According to the present disclosure, the siRNA can induce cancer cell death together with the PARP inhibitors in patients with wild-type BRCA genes with a low therapeutic effect of the PARP inhibitors, and the fusion protein-siRNA complex for siRNA delivery is up-taken into cells via CD47, and thus more specifically delivered to cancer cells while up-taken with high efficiency, thereby maximizing a desired cell death effect.