Patent ID: 7348139

Claim:
A method for identifying a neoplastic cell, which exhibits unregulated growth, comprising detecting methylation of a cytosine residue of a CpG dinucleotide in a CpG island of a suppressor of cytokine signaling-1 (SOCS-1) gene in a sample comprising a test cell, or an extract thereof, wherein detecting methylation comprises: contacting a nucleic acid molecule comprising the SOCS-1 of the test cell with bisulfite ions, whereby unmethylated cytosine residues in the SOCS-1 gene sequence are converted to bisulfite modified cytosine residues; exposing the bisulfite ion treated SOCS-1 gene sequence to alkaline conditions, whereby bisulfite modified cytosine residues are converted to uracil residues; contacting the bisulfite ion treated SOCS-1 gene sequence with an amplification primer pair under conditions suitable for amplification, wherein the amplification primer pair comprises SEQ ID NO:6 and SEQ ID NO:7; SEQ ID NO:12 and SEQ ID NO:13; SEQ ID NO:14 and SEQ ID NO:15; or SEQ ID NO:16 and SEQ ID NO:17; and determining the nucleotide sequence of the amplification product, thereby detecting the amount or distribution of uracil residues in the bisulfite ion treated SOCS-1 gene of the test cell, wherein a decrease in the amount or distribution of uracil residues in the SOCS-1 gene from the test cell, as compared to the amount or distribution of uracil residues in a corresponding bisulfite ion treated unmethylated SOCS-1 gene following exposure to alkaline conditions, is indicative of methylation of cytosine residues in CpG dinucleotides in the SOCS-1 gene of the test cell, and wherein said methylation results in a reduced level of transcription of the SOCS-1 gene in the test cell as compared to a corresponding normal cell, thereby identifying the test cell as a neoplastic cell.