Method of isolating circulating tumor cells

Abstract

Provided are methods for detecting or isolating circulating tumor cells (CTCs) in a subject. The methods may include detecting the expression of at least one epithelial mesenchymal transition (EMT) biomarker. Further provided are kits for detecting or isolating CTCs. The kits may include antibodies to at least one EMT biomarker. Further provided are methods of predicting the responsiveness of a subject to a cancer drug, methods of targeting delivery of a cancer drug in a subject, methods of providing a cancer prognosis to a subject, and methods for following the progress of cancer in a subject.

What is claimed is: 
     
         1 . A method of detecting the level of circulating tumor cell in a subject, the method comprising:
 a) obtaining a biological sample from the subject;   b) obtaining at least one capture binding protein, wherein the capture binding protein is linked to a solid phase to form a solid phase-capture binding protein complex;   c) contacting the biological sample with the solid phase-capture binding protein complex for a time sufficient to allow the solid phase-capture binding protein complex to bind at least one epithelial-mesenchymal transition (EMT) biomarker on a circulating tumor cell to form a solid phase-capture binding protein-circulating tumor cell complex;   d) separating the solid phase-capture binding protein-circulating tumor cell complex from the sample and unbound magnetic particle-capture binding protein complexes by application of an external magnetic field on the sample, thereby isolating or capturing the intact cell;   e) determining the level of circulating tumor cell in the solid phase-capture binding protein-circulating tumor cell complex.   
     
     
         2 . The method of  claim 1 , wherein determining the level of circulating tumor cell in the solid phase-capture binding protein-circulating tumor cell complex comprises at least one of DAPI staining, β-catenin detection, CD45 detection, and CD31 detection. 
     
     
         3 . The method of  claim 1 , wherein the EMT biomarker is at least one of OB-cadherin, N-cadherin, vimentin, E-cadherin, FGFR2 splice variant isoforms, or CD133. 
     
     
         4 . The method of  claim 1 , further comprising determining the presence or absence of at least one prostate cancer-specific genomic event. 
     
     
         5 . The method of  claim 4 , wherein the at least one prostate cancer-specific genomic event is selected from the group consisting of androgen receptor amplification, phosphatase and tensin homolog (PTEN) loss, gene fusion of transmembrane protease, serine 2 (TMPRSS2), and ETS related gene (ERG), and a combination thereof. 
     
     
         6 . The method of  claim 1 , wherein the biological sample comprises a tissue sample or a fluid sample from the subject. 
     
     
         7 . A kit for isolating or capturing a circulating tumor cell in a biological sample, the kit comprising:
 (1) a capture agent comprising an antibody specifically binding at least one epithelial-mesenchymal transition (EMT) biomarker; and   (2) a staining reagent for confirming the capture of the circulating tumor cell.   
     
     
         8 . The kit of  claim 7 , wherein the at least one EMT biomarker is at least one of OB-cadherin, N-cadherin, vimentin, E-cadherin, FGFR2 splice variant isoforms, or CD133. 
     
     
         9 . The kit of  claim 7 , wherein the at least one staining reagent comprises DAPI or a detectably labeled antibody selected from a detectably labeled anti-β-catenin antibody, a detectably labeled anti-CD45 antibody, or a detectably labeled anti-CD31 antibody. 
     
     
         10 . The kit of  claim 7 , wherein the antibody specifically binding at least one EMT biomarker is linked to a solid phase or an imaging agent. 
     
     
         11 . The kit of  claim 10 , wherein the solid phase is a microparticle, magnetic particle, or paramagnetic particle. 
     
     
         12 . The method of  claim 1 , wherein the circulating tumor cell is from breast cancer, colon cancer, lung cancer, prostate cancer, testicular cancer, brain cancer, skin cancer, rectal cancer, gastric cancer, esophageal cancer, sarcomas, tracheal cancer, head and neck cancer, pancreatic cancer, liver cancer, ovarian cancer, lymphoid cancer, cervical cancer, vulvar cancer, melanoma, mesothelioma, renal cancer, bladder cancer, thyroid cancer, bone cancer, carcinoma, sarcoma, and/or soft tissue. 
     
     
         13 . A method for detecting or identifying a circulating tumor cell or a level of a circulating tumor cell in a patient, the method comprising:
 (a) obtaining a biological sample from the patient;   (b) obtaining at least one capture binding protein, wherein the capture binding protein is linked to a solid phase to form a solid phase-capture binding protein complex;   (c) contacting the biological sample with the solid phase-capture binding protein complex for a time sufficient to allow the solid phase-capture binding protein complex to bind at least one epithelial-mesenchymal transition (EMT) biomarker on the circulating tumor cell to form a solid phase-capture binding protein-circulating tumor cell complex; and   (d) separating the solid phase-capture binding protein-circulating tumor cell complex from the sample and unbound magnetic particle-capture binding protein complexes by application of an external magnetic field on the sample, thereby detecting or identifying the circulating tumor cell or the level of the circulating tumor cell in the patient.   
     
     
         14 . The method of  claim 13 , further comprising at least one of DAPI staining, β-catenin detection, CD45 detection, and CD31 detection. 
     
     
         15 . The method of  claim 14 , wherein the circulating tumor cell is further detected or identified as a circulating tumor cell if DAPI staining is positive, β-catenin expression is positive, CD45 expression is negative, and CD31 expression is negative.