DETECTION OF EPHA3 AS A MARKER OF THE PRESENCE OF A SOLID TUMOR
The invention provides methods and compositions for detecting non-hematopoietic, non-tumor EphA3-expressing cells in cancer patients and for monitoring the prognosis of patients using EphA3.
1 . A method of identifying a patient that has a solid tumor, the method comprising:
providing a sample comprising peripheral blood mononuclear cells from a patient that may have a solid tumor;
detecting a level of EphA3 + non-hematopoietic, non-tumor cells in the sample above normal, thereby identifying a patient that has a solid tumor.
2 . The method of claim 1 , further comprising determining whether the EphA3 + cells are CD34 − .
3 . The method of claim 1 , further comprising determining whether the EphA3 + cells are CD45 − .
4 . The method of claim 1 , further comprising determining whether the EphA3 + cells express CD44, CD90, and/or KDR.
5 . The method of claim 1 , wherein the step of detecting the level of EphA3+ non-hematopoietic, non-tumor cells comprises detecting EphA3 expression on the surface of the cells.
6 . The method of claim 5 , wherein EphA3 expression on the surface of the cells is detected by flow cytometry.
7 . The method of claim 5 , wherein the step of detecting expression on the surface of the cells comprises contacting the cells with a first antibody that selectively binds to EphA3.
8 . The method of claim 7 , further comprising contacting the cells with a second antibody that selectively binds to EphA3 at an epitope that is different than the epitope to which the first antibody binds.
9 . The method of claim 8 , wherein the second antibody is labeled with the same detectable label as the first antibody.
10 . The method of claim 1 , wherein the patient has a breast carcinoma, a lung adenocarcinoma, a lung squamous cell carcinoma, a colon adenocarcinoma, a renal cell carcinoma, a transitional cell carcinoma, a prostate adenocarcinoma, or a melanoma.
11 . The method of claim 1 , wherein the step of detecting the level of EphA3+ non-hematopoietic, non-tumor cells comprises an RT-PCR reaction.
12 . The method of claim 1 , further comprising administering a cancer therapeutic agent to the patient.
13 . The method of claim 12 , wherein the cancer therapeutic agent is an anti-vascular therapeutic agent
14 . The method of claim 13 , wherein the anti-vascular therapeutic agent is a vascular endothelial growth factor (VEGF) antagonist or an antibody that activates EphA3.
15 . The method of claim 12 , wherein the cancer therapeutic agent in an antibody that selectively binds EphA3.
16 . A method of monitoring efficacy of a cancer therapeutic agent, the method comprising:
determining the level of EphA3+ non-hematopoietic, non-tumor cells in peripheral blood from a patient that has a solid tumor following a treatment with the cancer therapeutic agent;
comparing the level of EphA3+ non-hematopoietic, non-tumor cells in peripheral blood to the level prior to the treatment with the cancer therapeutic agent.
17 . The method of claim 16 , wherein the cancer therapeutic agent is an anti-vascular-therapeutic agent.
18 . The method of claim 17 , wherein the anti-vascular therapeutic agent is a VEGF antagonist or an antibody that activates EphA3.
19 . The method of claim 16 , wherein the cancer therapeutic agent is an antibody that selectively binds EphA3 + .
20 . The method of claim 16 , further comprising determining whether the EphA3 + cells are CD34 − .
21 . The method of claim 16 , further comprising determining whether the EphA3 + cells are CD45 − .
22 . The method of claim 16 , further comprising determining whether the EphA3 + cell express CD44, CD90, and/or KDR.
23 . The method of claim 16 , wherein the step of determining the level of EphA3 + non-hematopoietic, non-tumor cells comprises detecting EphA3 expression on the surface of the cells
24 . The method of claim 23 , wherein EphA3 expression on the surface of the cells is detected by flow cytometry.
25 . The method of claim 23 , wherein the step of detecting expression on the surface of the non-hematopoietic cells comprises contacting the cells with a first antibody that selectively binds to EphA3
26 . The method of claim 25 , further comprising contacting the cells with a second antibody that selectively binds to a different EphA3 epitope.
27 . The method of claim 26 , wherein the first and the second antibody are labeled with the same detectable label.
28 . The method of claim 16 , wherein the cancer therapeutic agent is a therapeutic antibody that selectively binds to EphA3 and the step of determining the level of EphA3+ non-hematopoietic, non-tumor cells comprises contacting the cells with an antibody that binds to an epitope different to the epitope to which the therapeutic antibody binds.
29 . The method of claim 16 , wherein the patient has a breast carcinoma, a lung adenocarcinoma, a lung squamous cell carcinoma, a colon adenocarcinoma, a renal cell carcinoma, a transitional cell carcinoma, a prostate adenocarcinoma, or a melanoma.
30 . The method of claim 16 , wherein the step of detecting expression of EphA3+ comprises an RT-PCR reaction.
31 . A kit for detecting the presence of non-hematopoietic cells in a sample, the kit comprising a first antibody that selectively binds to an EphA3 epitope and a second antibody that selectively binds to a different EphA3 epitope.
32 . The kit of claim 31 , wherein the first and the second antibodies are labeled with the same detectable label.
33 . The kit of claim 31 , further comprising an antibody that binds to a surface marker selected from the group consisting of CD34, CD45, CD90, and KDR.
34 . A method of identifying the presence or absence of a non-hematopoietic, non-tumor population of EphA3 + cells in peripheral blood from a patient, the method comprising:
providing a sample comprising peripheral blood cells from the patient;
detecting the presence or absence of expression of EphA3 + in non-hematopoietic, non-tumor cells in the sample, wherein the presence of EphA3+ expression on non-hematopoietic, non-tumor cells is indicative of the presence of a solid tumor.