PROTAC Estrogen Receptor Degrader
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current antiestrogens, such as tamoxifen, exhibit partial agonism, leading to incomplete blockade of estrogen-mediated activity in treating estrogen-dependent diseases like breast cancer, necessitating the development of selective estrogen receptor downregulators or degraders that can effectively reduce estrogen receptor expression.
Innovation Solution
Compounds that simultaneously bind to the estrogen receptor and the von Hippel-Lindau tumor suppressor E3 ubiquitin ligase, promoting ubiquitination and degradation of the estrogen receptor, are developed to inhibit estrogen receptor function.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional nonsteroidal antiestrogens like tamoxifen are used to compete for estrogen receptor binding, then estrogen-mediated activity is blocked, but partial agonism occurs resulting in incomplete blockade of estrogen-mediated activity
Solution Approach 1:
The invention extracts and eliminates the harmful partial agonist effect from the antiestrogen mechanism by transitioning from competitive binding (tamoxifen) to targeted protein degradation (PROTAC). The PROTAC molecule removes the estrogen receptor entirely from the system through ubiquitination and proteasomal degradation, rather than merely blocking its activity, thereby completely eliminating agonist effects while maintaining antagonist benefits.
Solution Approach 2:
The invention introduces an intermediary mechanism (E3 ubiquitin ligase) that mediates the degradation of the estrogen receptor. The PROTAC molecule acts as a bridge, simultaneously binding to the estrogen receptor and the E3 ubiquitin ligase, facilitating the transfer of the receptor to the degradation pathway. This intermediary approach enables complete receptor elimination without the partial agonism inherent in direct competitive antagonists.
2Reliability
If selective estrogen receptor downregulators or degraders are developed to reduce estrogen receptor expression, then complete blockade of estrogen-mediated activity is achieved, but device complexity increases
Solution Approach 1:
The invention merges two distinct functional elements into a single PROTAC molecule: an estrogen receptor-binding moiety and an E3 ubiquitin ligase-binding moiety connected by a linker. This combined structure enables the molecule to simultaneously recognize and bind both the target protein (estrogen receptor) and the degradation machinery (E3 ligase), achieving complete receptor degradation through a single integrated agent rather than multiple separate components.
Solution Approach 2:
The PROTAC molecule represents a composite molecular structure combining different functional domains: the estrogen receptor ligand portion, the linker region, and the E3 ligase binder portion. This composite architecture integrates multiple functions (target recognition, bridge formation, degradation signaling) into one molecule, enabling complete estrogen receptor blockade while managing structural complexity through functional modularity.
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
These compounds effectively degrade the estrogen receptor, providing a potent and selective mechanism to treat estrogen-dependent diseases with minimal agonist activity, potentially offering improved therapeutic outcomes over conventional antiestrogens.
Implementation Method 1
One suitable E3 ubiquitin ligase is the von Hippel-Lindau tumour suppressor (VHL). One approach would be to develop selective ER down regulators or degraders resulting in the reduction of ER expression at either the transcript or protein level.
Implementation Method 2
Several methods are available for the manipulation of protein levels, including proteolysis targeting chimeric molecules (PROTACs) which contain a ligand that recognizes the target protein linked to a ligand that binds to a specific E3 ubiquitin ligase.
Data Source
AI summary
A compound of formula (I) or a pharmaceutically acceptable salt thereof, compositions, combinations and medicaments containing said compounds and processes for their preparation. The invention also relates to the use of said compounds, combinations, compositions and medicaments, for example as inhibitors of the activity of the estrogen receptor, including degrading the estrogen receptor, the treatment of diseases and conditions mediated by the estrogen receptor.