Patent ID: 7368255

Claim:
A method for diagnosing cancers caused by a loss of RUNX3 expression due to the methylation of the nucleotide sequence of SEQ. ID. NO: 3, characterized by detecting the methylation of a nucleotide sequence SEQ. ID. NO: 3, containing CpG islands present near exon 1 of the RUNX3 gene, comprising the steps of: isolating genomic DNA from a tumor tissue of a subject; digesting the genomic DNA with a restriction enzyme sensitive to DNA methylation; separating the genomic DNA digests on an agarose gel by electrophoresis and transferring them onto a membrane; hybridizing the genomic DNA digests with a radiolabeled DNA probe for a RUNX3 gene; and exposing the membrane to a film and detecting the methylation of the nucleotide sequence of SEQ. ID. No: 3, whereby the detection of methylation indicates a cancer caused by a loss of RUNX3 expression.