CIRCULATING TUMOR CELL DIAGNOSTICS FOR BIOMARKERS PREDICTIVE OF RESISTANCE TO ANDROGEN RECEPTOR (AR) TARGETED THERAPIES
The disclosure provides a method of predicting resistance to androgen receptor (AR) targeted therapy in a prostate cancer patient comprising (a) performing a direct analysis comprising immunofluorescent staining and morphological characterization of nucleated cells in a blood sample obtained from the patient to identify circulating tumor cells (CTCs), and (b) based on said direct analysis further determining the presence of a biomarker signature that is predictive of resistance to AR targeted therapy in the prostate cancer patient, wherein the biomarker signature comprises CK+, AR+, nucleoli+ CTCs in a subpopulation of said CTCs. The present disclosure also provides a method of predicting resistance to taxane-based chemotherapy in a prostate cancer patient comprising (a) performing a direct analysis comprising immunofluorescent staining and morphological characterization of nucleated cells in a blood sample obtained from the patient to identify circulating tumor cells (CTCs), and (b) based on said direct analysis further determining the presence of a biomarker signature that is predictive of resistance to taxane-based chemotherapy in the prostate cancer patient, wherein the biomarker signature comprises CK+, AR−, nucleoli+, small size in a subpopulation of said CTCs.
1 . A method of predicting resistance to androgen receptor (AR) targeted therapy in a prostate cancer patient comprising
(a) performing a direct analysis comprising immunofluorescent staining and morphological characterization of nucleated cells in a blood sample obtained from the patient to identify circulating tumor cells (CTCs), and
(b) based on said direct analysis further determining the presence of a biomarker signature that is predictive of resistance to AR targeted therapy in the prostate cancer patient.
2 . The method of claim 1 , wherein the immunofluorescent staining of nucleated cells comprises pan cytokeratin (CK), cluster of differentiation (CD) 45, diamidino-2-phenylindole (DAPI) and AR.
3 . The method of claim 1 , wherein the biomarker signature comprises CK+, AR+, nucleoli+ CTCs in a subpopulation of said CTCs.
4 . The method of claim 1 , wherein the biomarker signature further comprises presence of AR N-terminal positive CTCs.
5 . The method of claim 4 , wherein the biomarker signature further comprises presence of AR C-terminal loss.
6 . The method of claim 1 , wherein the biomarker signature comprises increased heterogeneity of said CTCs compared to a reference population.
7 . A method of predicting resistance to chemotherapy in a prostate cancer patient comprising
(a) performing a direct analysis comprising immunofluorescent staining and morphological characterization of nucleated cells in a blood sample obtained from the patient to identify circulating tumor cells (CTCs), and
(b) based on said direct analysis further determining the presence of a biomarker signature that is predictive of resistance to chemotherapy in the prostate cancer patient.
8 . The method of claim 7 , wherein the biomarker signature comprises CK+, AR−, nucleoli+, small size in a subpopulation of said CTCs.
9 . The method of claim 7 , wherein presence of said biomarker signature further indicates resistance to taxane-based chemotherapy.
10 . The method of claim 1 , wherein the immunofluorescent staining of nucleated cells comprises pan cytokeratin (CK), cluster of differentiation (CD) 45, diamidino-2-phenylindole (DAPI) and AR.
11 . The method of claim 10 , wherein the AR immunofluorescent staining comprises N-terminal or C-terminal AR nuclear staining.
12 . The method of claim 1 , wherein said prediction informs a subsequent treatment decision.
13 . The method of claim 1 , wherein said CTCs comprise traditional CTCs, CTC clusters, CK− CTCs, and small CTCs.
14 . The method of claim 1 comprising an initial step of depositing the nucleated cells as a monolayer onto a slide.
15 . The method of claim 1 , wherein the prostate cancer is metastatic castration resistant prostate cancer (mCRPC).
16 . The method of claim 1 , wherein the identification of CTCs comprises fluorescent scanning microscopy.
17 . The method of claim 16 , wherein the microscopy provides a field of view comprising both CTCs and at least 200 surrounding white blood cells (WBCs).
18 . The method of claim 1 , wherein the direct analysis comprises assessing at least 4 million of the nucleated cells.
19 . The method of claim 1 , wherein the CTCs comprise distinct immunofluorescent staining from surrounding nucleated cells.
20 . The method of claim 1 , wherein the CTCs comprise distinct morphological characteristics compared to surrounding nucleated cells.
21 - 30 . (canceled)