Methods for the detection of circulating tumor cells
The present invention provides methods for revealing, detecting, and analyzing circulating tumor cells in the blood of a subject. Revealing detectable circulating tumor cells allows for early stage detection and diagnosis in addition to long term prognosis in subjects with cancer. Additionally, enrichment allows for robust detection and clinically meaningful analysis of low volume samples for use in clinical settings as well as innovative methods for the treatment of cancers.
1. A method for revealing circulating tumor cells in a sample obtained from a subject comprising:
a) obtaining a sample from the subject;
b) removing or degrading a protein, carbohydrate, cell, or a combination thereof, in physical association with the surface of the circulating tumor cells present in the sample, wherein the circulating tumor cells remain intact, thereby unmasking and revealing the circulating tumor cells in the sample; and
c) analyzing one or more circulating tumor cells of (b), the analysis comprising characterizing morphology of the one or more circulating tumor cells via image analysis.
2. The method of claim 1 , wherein revealing the cells comprises removing all or portions of blood plasma proteins, platelets, or a combination thereof.
3. The method of claim 2 , wherein the blood plasma protein is a clotting factor.
4. The method of claim 3 , wherein the clotting factor is fibrin.
5. The method of claim 1 , wherein the cells are treated enzymatically, mechanically, electrically, electromagnetically, chemically, or any combination thereof.
6. The method of claim 5 , wherein the cells are treated enzymatically.
7. The method of claim 6 , wherein the enzymatic treatment is by fibrinolysis.
8. The method of claim 7 , wherein fibrinolysis is with plasmin.
9. The method of claim 7 , wherein enzymatic treatment is by incubation with an animal venom or a toxin.
10. The method of claim 9 , wherein the animal venom or toxin is naturally occurring or synthetically derived from a snake or a bat.
11. The method of claim 5 , wherein enzymatic treatment is by activation of plasminogen.
12. The method of claim 1 , wherein treatment of the cells is performed using an anti-coagulant or a blood thinner.
13. The method of claim 1 , wherein the number of revealed circulating tumor cells is increased by a factor of at least 2, 5, 10, 20, 30, 40, 50, 60, 70, 80, 90, 100, or 200.
14. The method of claim 1 , wherein the sample is about 200 microliters.
15. The method of claim 1 , wherein the revealed cells comprise greater than about 7.5 circulating tumor cells per 100 microliters.
16. The method of claim 1 , further comprising enriching the sample.
17. The method of claim 16 , wherein the sample is enriched immunomagnetically or by filtration.
18. The method of claim 1 , further comprising cell number analysis, polymerase chain reaction (PCR) analysis, sequence analysis, DNA analysis, RNA analysis, gene expression profiling, proteome analysis, metabolome analysis, immuno assays, nuclear exclusion analysis.
19. The method of claim 1 , wherein the image analysis comprises detection of a cell surface marker.
20. The method of claim 19 , wherein the cell surface marker is selected from the group consisting: EGFR, HER2, ERCC1, CXCR4, EpCAM, E-Cadherin, Mucin-1, Cytokeratin, PSA, PSMA, RRM1, Androgen Receptor, Estrogen Receptor, Progesterone Receptor, IGF1, cMET, EML4, or Leukocyte Associated Receptor (LAR).
21. The method of claim 19 , wherein antibodies are used to detect the cell surface markers.
22. The method of claim 21 , wherein the antibodies are fluorescently labeled.
23. The method of claim 22 , wherein the antibodies are directed to EpCAM, Cytokeratin, or a combination thereof.
24. The method of claim 1 , wherein the image analysis is performed by microscopy or flow cytometry.
25. The method of claim 18 , wherein the PCR analysis comprises multiplexing using primers specific for genes selected from the group consisting of EGFR, HER2, ERCC1, CXCR4, EpCAM, E-Cadherin, Mucin-1, Cytokeratin, PSA, PSMA, RRM1, Androgen Receptor, Estrogen Receptor, Progesterone Receptor, IGF1, cMET, EML4, or Leukocyte Associated Receptor (LAR).
26. The method of claim 18 , wherein the nuclear exclusion analysis comprises nuclear exclusion of the Androgen Receptor.
27. The method of claim 1 , further comprising providing a diagnosis and prognosis to a subject from which the sample was taken.
28. The method of claim 1 , wherein the subject is known to have cancer and is undergoing cancer therapy.
29. The method of claim 28 , wherein the therapy is chemotherapy.
30. The method of claim 28 , wherein the subject is being administered a candidate agent.
31. The method of claim 28 , further comprising determining the responsiveness of the subject to the cancer therapy.
32. A method of detecting tumor cell type of a circulating tumor cell in a sample from a subject comprising:
a) removing or degrading a protein, carbohydrate, cell, or a combination thereof, in physical association with the surface of the circulating tumor cell present in the sample, wherein the circulating tumor cell remains intact, thereby unmasking and revealing the circulating tumor cell in the sample; and
b) analyzing the circulating tumor cell of (a) to determine cell type of the circulating tumor cell.
33. The method of claim 32 , wherein analyzing comprises image analysis, cell number analysis, cell morphology analysis, polymerase chain reaction (PCR) analysis, sequence analysis, DNA analysis, RNA analysis, gene expression profiling, proteome analysis, metabolome analysis, immuno assays, nuclear exclusion analysis.