ERα Inhibitors Targeting DNA Binding Interface
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Solution Overview
Problem
Current approaches to inhibiting estrogen receptor alpha (ERα) action in cancer cells, particularly in tamoxifen-resistant breast cancer, are limited as they primarily target ligand binding, and there is a need for new strategies that can effectively block ERα's interaction with estrogen response elements to inhibit cancer cell growth.
Innovation Solution
Development of small molecule inhibitors, such as theophylline derivatives, that specifically target ERα's interaction with estrogen response elements, altering its conformation or binding properties to inhibit gene expression and cell growth without competing with estrogens for binding, thereby blocking estrogen-dependent cancer cell growth.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If small molecules are used to target ERα interaction with ERE DNA, then new therapeutic strategies can be developed for tamoxifen-resistant cancer, but the large interaction surfaces of protein-DNA complexes make direct binding difficult
Solution Approach 1:
The patent uses an antibody as an intermediary molecule to block the interaction between ERα and ERE DNA. The antibody binds to the ERα protein at or near the DNA-binding interface, preventing direct protein-DNA contact without requiring the small molecule to directly compete with the large DNA interaction surface. This intermediary approach resolves the contradiction by using a differently-sized molecule (antibody) that can access and block the interface.
Solution Approach 2:
The patent changes the molecular class from small molecules to antibodies, fundamentally altering the size and binding characteristics of the inhibitor. This parameter change allows the inhibitor to target the protein-DNA interface effectively, as antibodies have the appropriate size and structural features to access and block large interaction surfaces that are inaccessible to small molecules.
2Reliability
If current approaches target ligand binding in ERα, then ERα activation can be inhibited, but tumors develop resistance to tamoxifen and other SERMs over time
Solution Approach 1:
The patent extracts the inhibition mechanism from the ligand-binding pocket approach and relocates it to the DNA-binding interface. By targeting a different functional site on ERα (the protein-DNA interaction interface rather than the ligand-binding pocket), the therapy achieves reliable ERα inhibition through an alternative mechanism that tumors have not developed resistance to, thereby extending the duration of therapeutic effect.
Solution Approach 2:
Instead of preventing ERα activation by blocking ligand binding (the conventional approach), the patent inverts the strategy by allowing ligand binding to occur but blocking the subsequent DNA-binding function of ERα. This inverted approach targets a downstream step in the activation pathway, achieving inhibition through a different mechanism that avoids resistance development.
3Reliability
If small molecules are designed to bind at the protein-DNA interface, then ERα-mediated gene transcription can be blocked, but the complexity of identifying such molecules increases
Solution Approach 1:
The patent employs an antibody as an intermediary to block the protein-DNA interface, simplifying the identification process. Rather than screening for small molecules that can access and bind to the complex protein-DNA interface (a difficult task), the approach uses antibodies that naturally have the size and structural features to bind such interfaces, thereby reducing the complexity of molecule identification while achieving reliable transcription blocking.
Data Source
AI summary
The disclosure herein relates to nuclear hormone receptors including steroid hormone receptors, for example in connection with estrogen, progesterone, and androgen. Embodiments of compositions and methods are disclosed including such relating to compounds, including substituted theophyllines, capable of functioning as inhibitors of estrogen receptor alpha-mediated gene expression and having the ability to modify cancer cells and treat cancer, including breast cancers and resistant breast cancers, particularly those that are resistant to tamoxifen. In embodiments, methods of inhibiting breast cancer cells and resistant breast cancer cells are provided. In embodiments, a useful inhibitor compound includes TPSF/NSC 97998 and other compounds.