Method and reagent for detecting ovarian clear cell adenocarcinoma
The present invention aims to provide a method for detecting, with high sensitivity and specificity, ovarian clear cell adenocarcinoma, which is highly malignant, among benign and malignant ovarian tumors having various tissue types, and a reagent that can be used for the method. The present invention provides NT-TFPI2, which is a novel processed tissue factor pathway inhibitor 2 polypeptide, as a new detection marker for ovarian clear cell adenocarcinoma. The detection of ovarian clear cell adenocarcinoma is carried out by measuring the amount of NT-TFPI2, or the total amount of NT-TFPI2 and intact TFPI2. The reagent for detecting ovarian clear cell adenocarcinoma contains an antibody that specifically recognizes NT-TFPI2 and intact TFPI2.
1. A method for detecting ovarian clear cell adenocarcinoma, said method comprising measuring the amount of a processed tissue factor pathway inhibitor 2 (TFPI2) polypeptide in a sample,
wherein the processed TFPI2 polypeptide has the following properties (i) to (iii):
(i) a polypeptide having the amino acid sequence from the 23th residue aspartic acid to the 131st residue histidine or to the 130th residue cysteine in the TFPI2 amino acid sequence of SEQ ID NO:1, or a sequence having an identity of not less than 80% to this sequence;
(ii) a polypeptide that is fractionated into a molecular weight of about 16,000 by reducing SDS-PAGE; and
(iii) a polypeptide whose peptide fragment obtained after asparagine-linked sugar chain cleavage treatment is fractionated into a molecular weight of about 12,000 by reducing SDS-PAGE, and
wherein said measurement is performed by antigen-antibody reaction using an antibody that binds to an antigenic determinant in the region from the aspartic acid at position 23 to the histidine at position 131 or to the cysteine at position 130, in the amino acid sequence of SEQ ID NO: 1.
2. The method according to claim 1 , further comprising measuring the amount of intact TFPI2 in said sample.
3. The method according to claim 2 , wherein ovarian clear cell adenocarcinoma is judged to be detected in cases where the total of said amount of the processed TFPI2 polypeptide and said amount of intact TFPI2 exceeds a reference value calculated from a control.
4. The method according to claim 1 , wherein said antibody is an antibody that recognizes Kunitz domain 1 of TFPI2.