Spatial biomarker of disease and detection of spatial organization of cellular receptors
A signature of a condition of a live cell is established in an assay that allows distribution of the receptors on the cell surface in response to binding a ligand. The receptors can be optically detected and quantified to provide a value for the condition, Test drugs can be screened for therapeutic potential in the assay: a potentially efficacious drug is identified by an ability to modulate an established signature. The receptor distribution signature can be corroborated with an mRNA expression profile of several genes, indicating, for example, metastasis.
1. An assay comprising the steps of:
(a) providing a live cell derived from a subject suspected of having cancer, wherein the live cell having a plurality of a Eph receptor on the cell surface, said live cell being capable of activating Eph receptor redistribution on the surface of the cell, the Eph receptor capable of binding a ligand, whereupon binding of the ligand by said plurality of a Eph receptor activates receptor redistribution and results in a detectable pattern of the plurality of Eph receptors distributed on the surface of the cell;
(b) providing a physical context wherein the physical context further comprises a supported lipid bilayer having the ligand displayed or attached thereto;
(c) contacting said live cell to the ligand attached to said physical context;
(d) detecting and quantifying the pattern of Eph receptor redistribution and activation of said pattern of Eph receptor distribution on the surface of the cell where said live cell is attached, wherein the quantifying step (d) further comprises determining a normalized radial transport or radial distribution score of the pattern of Eph receptor redistribution;
(e) correlating said detectable pattern of Eph receptor redistribution to a signature for aggressive cancer cells or metastatic cancer cells; and
(f) providing a diagnosis of the subject's condition based on said correlation to the aggressive or metastatic cancer cells and administering a therapeutic appropriate to treat such cancer cells in said subject.
2. The assay of claim 1 , wherein the Eph receptor is labeled with a detectable label and the pattern of labeled Eph receptors distributed on the cell surface is detected by an optical label tracking the labeled Eph receptor, and label intensity quantifies the signature.
3. The assay of claim 1 , wherein the physical context further comprising a grid or diffusion barriers, thereby providing grid areas within the grid or diffusion barriers and the supported lipid bilayer is provided in the grid areas.
4. The assay of claim 1 , wherein the ligand is a cell-surface protein.
5. The assay of claim 1 , further comprising components for detection of mRNA expression of a marker selected from EFNA1, GRB7, ITGB1, ITGB2, CAV2 or LYN after ligand-receptor binding.
6. The assay of claim 5 , comprising components for detection of mRNA for each of EFNA1, GRB7, ITGB1, ITGB2, CAV2 and LYN genes in a profile to determine a likelihood of metastasis.
7. The assay of claim 6 , wherein the gene profile corroborates the Eph receptor distribution signature and both identify a metastatic condition.
8. The assay of claim 1 , further comprising contacting a test drug with the physical context, wherein the physical context is adapted to allow contact of the test drug with the plurality of a Eph receptor on said cell to test for modulation of a signature for aggressive or metastatic cancer cells.
9. The assay of claim 1 , wherein the ligand is a protein, antibody, peptide, nucleic acid, small molecule, drug, or carbohydrate.
10. The assay of claim 2 , wherein the Eph receptor is distributed over an approximate span of the cell surface between about 10 nanometers and about 10 microns.
11. The assay of claim 2 , wherein the detectable label is a fluorescent label.
12. The assay of claim 1 , wherein detecting step (d) comprises observing and measuring the activation of Eph receptor redistribution and wherein the detectable pattern of Eph receptor redistribution comprises clusters of Eph receptors on the surface of the cell.
13. The assay of claim 9 , wherein the ligand is labeled with a detectable label.