Detecting Defective APC Protein CTCs via Dual Antibody Signal Ratios
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Solution Overview
Problem
Current methods are inadequate for detecting circulating tumor cells (CTCs) containing defective APC proteins, which are associated with tumor formation, recurrence, and metastasis.
Innovation Solution
A method involving the use of two labeled antibodies, one capable of binding to both wild-type and defective APC proteins, and the other specifically binding to wild-type APC proteins, to differentiate and detect CTCs containing defective APC proteins based on signal ratios.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a single antibody targeting APC protein is used for detection, then the detection method is simple, but it cannot distinguish between wild-type and defective APC proteins
Solution Approach 1:
The detection method is segmented into two distinct antibody targets: one antibody recognizes both wild-type and defective APC proteins (providing a reference signal), while the second antibody specifically recognizes only wild-type APC proteins. By comparing the signals from these two antibodies, the method can differentiate between wild-type and defective APC-containing cells. This segmentation of recognition specificity allows precise differentiation while maintaining relative methodological simplicity.
2Measurement precision
If two labeled antibodies are used to differentiate APC protein types, then detection precision is improved, but the detection method becomes more complex
Solution Approach 1:
The first antibody (capable of binding both wild-type and defective APC) serves as an intermediary reference marker. It provides a baseline signal that indicates the total presence of APC protein variants. The second antibody (specific to wild-type only) then acts as a differential marker. By comparing the intermediate reference signal with the specific wild-type signal, the method achieves precise differentiation while managing complexity through a hierarchical recognition strategy.
3Ease of operation
If immunostaining with antibody against C-terminus of APC is used, then the procedure is straightforward, but defective APC proteins are not detected
Solution Approach 1:
Instead of relying on a single antibody targeting a specific local region (C-terminus) of the APC protein, the invention employs two antibodies with different recognition specificities. The first antibody recognizes epitopes present in both wild-type and defective forms (providing universal detection), while the second antibody targets epitopes specific to wild-type APC. This multi-local recognition approach ensures that defective APC proteins, which may have altered C-termini, are still reliably detected through the first antibody's broader recognition.
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
This method enables the accurate detection of CTCs with defective APC proteins, providing a clinically useful tool for monitoring cancer recurrence and metastasis.
Implementation Method 1
the first labeled antibody comprises an antibody capable of binding to a wild-type APC protein and a defective APC protein
Implementation Method 2
the second labeled antibody comprises an antibody capable of binding to the wild-type APC protein and not to the defective APC protein
Implementation Method 3
the first labeling substance and the second labeling substance are fluorescent substances having fluorescence emission maxima in different wavelength ranges
Data Source
Figure 1A~1C
Figure 2A~2C
Figure 2D~3
AI summary
Disclosed is a method for detecting circulating tumor cells containing defective APC protein, comprising immunostaining circulating tumor cells in the blood using a labeled antibody that binds to both wild-type and defective APC proteins, and a labeled antibody that binds to wild-type but not defective APC proteins, and measuring the signal derived from the label.