A Second Look or, Not to Mention the Occasional Capsizing of a Windsurfer

Of all of the epithelial ovarian cancers (EOC), clear cell adenocarcinoma (CCA) has the worst clinical prognosis. Furthermore, the conventional EOC biomarker CA125 is more often negative in CCA than in other subtypes of EOC. This study sought to discover a new diagnostic biomarker that would allow more reliable detection of CCA. Using mass spectrometry, we compared proteins in conditioned media from cell lines derived from CCA and other types of EOC. We identified 30 extracellular or released proteins specifically present in CCA-derived cell lines. Bioinformatics analyses identified a serine protease inhibitor, tissue factor pathway inhibitor 2 (TFPI2), as a potential biomarker for CCA. Real time RT-PCR and Western blot analyses revealed that TFPI2 was exclusively expressed in CCA-derived cell lines and tissues. For clinical validation, we measured levels of TFPI2 and CA125 in a set of sera from 30 healthy women, 30 patients with endometriosis, and 50 patients with CCA, using an automated enzyme-linked immunosorbent assay systems. Serum levels of TFPI2 were significantly elevated in CCA patients, even those with normal CA125 levels. In terms of area under the receiver operating characteristic curve (AUC), TFPI2 was superior to CA125 in discriminating CCA patients from healthy women (AUC 0.97 for TFPI2 versus AUC 0.80 for CA125), or from patients with endometriosis (AUC 0.93 for TFPI2 versus 0.80 for CA125). This is the first evidence for TFPI2 as a serum biomarker of CCA. We propose that this biomarker may be useful for detection of CCA and for monitoring the transformation from endometriosis into CCA

Secretome-Based Identification of TFPI2, A Novel Serum Biomarker for Detection of Ovarian Clear Cell Adenocarcinoma

Of all of the epithelial ovarian cancers (EOC), clear cell adenocarcinoma (CCA) has the worst clinical prognosis. Furthermore, the conventional EOC biomarker CA125 is more often negative in CCA than in other subtypes of EOC. This study sought to discover a new diagnostic biomarker that would allow more reliable detection of CCA. Using mass spectrometry, we compared proteins in conditioned media from cell lines derived from CCA and other types of EOC. We identified 30 extracellular or released proteins specifically present in CCA-derived cell lines. Bioinformatics analyses identified a serine protease inhibitor, tissue factor pathway inhibitor 2 (TFPI2), as a potential biomarker for CCA. Real time RT-PCR and Western blot analyses revealed that TFPI2 was exclusively expressed in CCA-derived cell lines and tissues. For clinical validation, we measured levels of TFPI2 and CA125 in a set of sera from 30 healthy women, 30 patients with endometriosis, and 50 patients with CCA, using an automated enzyme-linked immunosorbent assay systems. Serum levels of TFPI2 were significantly elevated in CCA patients, even those with normal CA125 levels. In terms of area under the receiver operating characteristic curve (AUC), TFPI2 was superior to CA125 in discriminating CCA patients from healthy women (AUC 0.97 for TFPI2 versus AUC 0.80 for CA125), or from patients with endometriosis (AUC 0.93 for TFPI2 versus 0.80 for CA125). This is the first evidence for TFPI2 as a serum biomarker of CCA. We propose that this biomarker may be useful for detection of CCA and for monitoring the transformation from endometriosis into CCA

Clinical Significance of Tissue Factor Pathway Inhibitor 2, a Serum Biomarker Candidate for Ovarian Clear Cell Carcinoma - Fig 2

<p><b>ROC and AUC values for serum CA125 and TFPI2 levels in discrimination of CCC from other ovarian diseases (benign diseases, borderline, and non-CCC EOCs) (A), CCC versus borderline ovarian tumors (BD) and non-CCC EOCs (B), and CCC versus EMS (C).</b> Red line, TFPI2; black dotted line, CA125. Numbers indicate the calculated AUC values for TFPI2 and CA125.</p

Distribution of CA125 and TFPI2 in serum samples from patients with CCC and other gynecological diseases (retrospective training set, n = 268), along with TFPI2 mRNA levels in their tissue samples.

<p>Serum CA125 levels in patients with CCC, other ovarian diseases, and uterine (Ut) diseases (<b>A</b>). Distribution of CA125 levels at the time of sample collection. Serum TFPI2 levels in patients with CCC, other ovarian diseases, or Ut diseases in the training set (<b>B</b>). Serum TFPI2 levels in samples of the training set were measured by the Pre-Diluted Assay as described in Materials and Methods. Comparison of CA125 (<b>C</b>) and TFPI2 (<b>D</b>) levels in patients with EMS, non-EMS, each EOC subtypes, and various Ut tumors (UF: uterine fibroids, cervical cancer, endometrial cancer). Box plots display 5^th, 25^th, 50^th (median, middle horizontal line), 75^th, and 95^th, percentiles. Statistical analysis was performed by nonparametric Mann-Whitney <i>U</i> test.</p

Clinicopathologic characteristics of the patients.

<p>Clinicopathologic characteristics of the patients.</p

Sources of samples.

<p>Sources of samples.</p