Methods and Compositions for the Diagnosis of Cancer Susceptibilities and Defective DNA Repair Mechanisms and Treatment Thereof

Abstract

Methods and compositions for the diagnosis of cancer susceptibilities, defective DNA repair mechanisms and treatments thereof are provided. Among sequences provided here, the FANCD2 gene has been identified, and probes and primers are provided for screening patients in genetic-based tests and for diagnosing Fanconi Anemia and cancer. The FANCD2 gene can be targeted in vivo for preparing experimental mouse models for use in screening new therapeutic agents for treating conditions involving defective DNA repair. The FANCD2 polypeptide has been sequenced and has been shown to exist in two isoforms identified as FANCD2-S and the monoubiquinated FANCD-L form. Antibodies including polyclonal and monoclonal antibodies have been prepared that distinguish the two isoforms and have been used in diagnostic tests to determine whether a subject has an intact Fanconi Anemia/BRCA pathway.

1 .- 41 . (canceled) 
     
     
         42 . A method of determining the response of a cell from a subject to an agent capable of inducing DNA damage, comprising:
 a) providing a tissue sample from said subject;   b) inducing DNA damage in the cells of said tissue sample; and   c) detecting FANCD2 ubiquitination or FANCD2 foci formation in said cells, wherein a low level of FANCD2 ubiquitination or FANCD2 foci formation detected in c) as compared to the level of FANCD2 ubiquitination or FANCD2 foci formation in a control cell indicates that said cell will respond to said agent.   
     
     
         43 . The method of  claim 42 , wherein said cell is a cancer cell. 
     
     
         44 . The method of  claim 43 , wherein said cancer is breast cancer, ovarian cancer, or prostate cancer. 
     
     
         45 . The method of  claim 42 , wherein DNA damage is induced in said control cell before FANCD2 ubiquitination or FANCD2 foci formation is detected in said control cell. 
     
     
         46 . The method of  claim 42 , wherein said DNA damage in b) is induced by an agent selected from the group consisting of ethidium bromide, acridine orange, free radicals, ionizing radiation, and UV radiation. 
     
     
         47 . The method of  claim 42 , wherein said detection in c) comprises an immunological method. 
     
     
         48 . The method of  claim 47 , wherein said immunological method is immunohistochemistry, immunofluorescence, or immunoblotting. 
     
     
         49 . The method of  claim 42 , wherein said agent is cisplatin. 
     
     
         50 . The method of  claim 43 , wherein said ubiquitination is monoubiquitination. 
     
     
         51 . A method of detecting a ubiquitinated FANCD2, comprising:
 a) providing one or more cells from a subject;   b) inducing DNA damage in said cells; and   c) detecting said ubiquitinated FANCD2 in said cells by an immunological assay.   
     
     
         52 . The method of  claim 51 , wherein said immunological assay is immunohistochemistry, immunofluorescence, or immunoblotting. 
     
     
         53 . The method of  claim 51 , wherein said ubiquitinated FANCD2 is a monoubiquitinated.