Cell division marker
This application relates to a newly identified animal cell structure, the midbody scar. This structure is a remnant of the midbody that is retained by one daughter cell following cytokinesis and persists through multiple subsequent cell cycles. The midbody scar can be useful as a marker of dividing cells or of a cell's replicative age.
1. A method of identifying a cancer stem cell in a sample comprising a population of mammalian cells, the method comprising:
providing a sample comprising a population of mammalian cells that is suspected of containing a cancer stem cell;
detecting a cell having two or more midbody scars by a method comprising contacting the sample with an antibody or an antigen-binding portion thereof that binds specifically to a polypeptide component of a midbody scar selected from the group consisting of: mitotic kinesin-like protein 1 (MKLP1), Epsilon tubulin (ε-tubulin), Centrosomal Protein 55KDa (Cep55), and Aurora B kinase;
detecting binding of the antibody or antigen-binding portion thereof to the polypeptide component, wherein a ring structure not at a midbody or centrosome is a midbody scar; and
identifying a cell in the sample having two or more midbody scars as being a cancer stem cell.
2. The method of claim 1 , wherein a cell in the sample having more than four midbody scars is identified as a cancer stem cell.
3. The method of claim 1 , wherein the sample is from a subject suspected of having a cancer.
4. The method of claim 3 , wherein the subject is human.
5. The method of claim 4 , wherein the sample comprises a population of cells from skin, heart, neural tissue, bone marrow, blood, liver, or lung.
6. The method of claim 5 , wherein the sample comprises a population of cells from blood.
7. The method of claim 4 , wherein the sample is a pathology specimen.
8. The method of claim 7 , wherein the pathology specimen is a fixed tissue sample.
9. The method of claim 1 wherein the antibody or antigen-binding portion thereof is conjugated to a detectable label.
10. The method of claim 9 , wherein the detectable label is selected from the group consisting of: a fluorescent moiety, a radioactive isotope, an enzyme, a contrast agent, and a magnetic particle.
11. The method of claim 10 , wherein the detectable label is a fluorescent moiety.
12. The method of claim 11 , wherein the detecting of the binding of the antibody or antigen-binding portion thereof to the polypeptide component is performed by measuring the fluorescence of the cell contacted with the antibody or antigen-binding portion thereof.
13. The method of claim 12 , wherein the detecting is automated.
14. The method of claim 13 , wherein the automated detection is performed using fluorescence-assisted cell sorting.
15. The method of claim 10 , wherein the detectable label is a magnetic particle.
16. The method of claim 15 , wherein the detecting is automated.
17. The method of claim 16 , wherein the automated detection is performed using magnetic-activated cell sorting.
18. The method of claim 1 , further comprising isolating the identified cancer stem cell from the sample.
19. The method of claim 18 , further comprising culturing the isolated cancer stem cell.