P450rai-2 (p450 cytochrome 26b), encoding nucleic acid molecules and methods and uses thereof

Abstract

The present invention provides a novel all-trans-RA inducible all-trans-RA metabolizing cytochrome P450, P450RAI-2, that is predominantly expressed in the brain, cerebellum in particular. It is also expressed in normal and tumour lung tissue and in breast cancer cells and may have a correlation with lung and breast cancer. Human P450RAI-2 show 42% amino acid identity to human P450RAI-1 and when transfected into COS-1 cells causes the rapid conversion of all-trans-RA into more polar metabolites including the inactive products 4-oxo-RA, 4-OH-RA and 18-OH-RA. P450RAI-2, as with P450RAI-1, is also inducible in certain cultured cell lines exposed to all-trans-RA. Methods for and uses of the new polynucleotide, polypeptide, fragments thereof and inhibitors thereof, include the treatment of dermatological disorders, cancer and certain brain disorders.

1 . A method for inhibiting P450RAI-2 induced retinoic acid hydroxylation in an organism or an in vitro system by administering a polyclonal antibody to a cytochrome P450 retinoic acid metabolizing peptide comprising the amino acid sequence of SEQ. ID. No. 5 to the organism or the in vitro system. 
     
     
         2 . The method of  claim 1  wherein the organism is human. 
     
     
         3 . The method of  claim 1  wherein the organism is being treated for a disease selected from the group consisting of cancer, actinic keratosis, oral leukoplakia, a secondary tumor of the head and/or neck, a non-small cell lung carcinoma, a basal cell carcinoma, acute promyelocytic leukemia, skin cancer, and a premalignancy associated actinic keratosis, acne, psoriasis and/or ichthyosis. 
     
     
         4 . The method of  claim 3  wherein the disease is acute promyelocytic leukemia. 
     
     
         5 . The method of  claim 3  wherein the disease is lung cancer. 
     
     
         6 . The method of  claim 5  wherein the lung cancer is non-small cell lung cancer. 
     
     
         7 . A method for the screening of the expression of P450RAI-2 in a sample, comprising exposing the sample to a polyclonal antibody to a cytochrome P450 retinoic acid metabolizing peptide comprising the amino acid sequence of SEQ. ID. NO. 5 and assaying for the presence P450RAI-2 and antibody interaction. 
     
     
         8 . The method of  claim 7  wherein the antibody is a labeled antibody to enable detection of binding and non-binding to a P450RAI-2 substrate. 
     
     
         9 . The method of  claim 7  wherein the assay is an ELISA assay. 
     
     
         10 . The method of  claim 7  for diagnosing non-small lung cell carcinoma in a patient. 
     
     
         11 . The method of  claim 8  for diagnosing non-small lung cell carcinoma in a patient. 
     
     
         12 . The method of  claim 9  for diagnosing non-small lung cell carcinoma in a patient. 
     
     
         13 . A kit for determining the presence of a first nucleic acid molecule of SEQ. ID NO. 4, the kit comprising a second nucleic acid molecule capable of hybridizing with at least a portion of a first nucleic acid molecule under high stringency conditions, in which the second nucleic acid molecule is linked to a reporter system wherein the reporter system produces a detectable response when a predetermined amount of the first and second molecules are hybridized together. 
     
     
         14 . The kit of  claim 13  wherein the second nucleic acid molecule is at least 5 bases in length, or at least about 10 bases in length, or at least about 15 bases in length, or at least about 20 bases in length, or at least about 25 bases in length, or at least about 30 bases in length, or at least about 35 bases in length, or at least about 40 bases in length, or at least about 45 bases in length, or at least about 50 bases in length. 
     
     
         15 . The kit of  claim 13  for the diagnosis of non-small lung cell carcinoma in a patient. 
     
     
         16 . The kit of  claim 14  for the diagnosis of non-small lung cell carcinoma in a patient.