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.

Description

RELATED APPLICATIONS[0001]This application is a continuation of U.S. application Ser. No. 12 / 749,419, filed Mar. 29, 2010, pending, which is a continuation of U.S. application Ser. No. 10 / 165,099, filed Jun. 6, 2002, abandoned, which is a continuation-in-part of U.S. application Ser. No. 09 / 998,027, filed Nov. 2, 2001, abandoned, which in turn claims priority from U.S. Provisional Application No. 60 / 245,756, filed Nov. 3, 2000. The entire contents of each of the above applications are incorporated herein by reference.GOVERNMENT SUPPORT[0002]The work described herein was supported by the National Institute of Health, NIH Grant No. Health grants RO1HL52725-04, RO1DK43889-09, 1PO1HL48546, and PO1HL54785-04. The US Government has certain rights to the claimed invention.INCORPORATION BY REFERENCE[0003]The contents of the text file named “20363—201C01US_ST25.txt”, which was created on Oct. 29, 2002 and is 132 KB in size, are hereby incorporated by reference in their entirety.BACKGROUND[00...

AI Technical Summary

Benefits of technology

[0043]In an embodiment of the invention, a method is provided for determining a therapeutic protocol for a subject having a cancer, that includes (a) determining if a deficiency in FANCD2-L occurs in a cell sample from the subject by measuring FANCD2 isoforms using specific antibodies; (b) if a deficiency is detected in (a), then determining whether the deficiency is a result of genetic defect in non-cancer cells; and (c) if (b) is positive, reducing the use of a therapeutic protocol that causes increased DNA damage so as to protect normal tissue in the subject and if (b) is negative, and the deficiency is contained within a genetic defect in cancer cells only, then increasing the use of a therapeutic protocol that causes increased DNA damage so as to adversely affect the cancer cells.

[0078]As used herein, the term “cancer therapeutic” refers to a compound that prevents the onset or progression of cancer or prevents cancer metastasis or reduces, delays, or eliminates the symptoms of cancer.

[0082]As used herein, “resistance to one or more anti-neoplastic agents” refers the ability of cancer cells to develop resistance to anticancer drugs. Mechanisms of drug resistance include decreased intracellular drug levels caused by an increased drug efflux or decreased inward transport, increased drug inactivation, decreased conversion of drug to an active form, altered amount of target enzyme or receptor (gene amplification), decreased affinity of target enzyme or receptor for drug, enhanced repair of the drug-induced defect, decreased activity of an enzyme required for the killing effect (topoisomerase II). In a preferred embodiment of the invention, drug resistance refers to the enhanced repair of DNA damage induced by one or more anti-neoplastic agents. In another preferred embodiment of the invention, the enhanced repair of DNA damage induced by one or more anti-neoplastic agents is due to a constitutively active Fanconi Anemia / BRCA DNA repair pathway.

Problems solved by technology

Diagnosis of FA is complicated by the wide variability in FA patient phenotype.

Moreover, existing diagnostic tests do not differentiate FA carriers from the general population.

Diagnosing cancer susceptibility is complicated because of the large number of regulatory genes and biochemical pathways that have been implicated in the formation of cancers.

Genetic lesions that are associated with defective repair mechanisms may give rise to defective cell division and apoptosis which in turn may increase a patient's susceptibility to cancer.

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