Carcinoembryonic antigen isotypes in tissue sections and loose cyst fluid cells of ovarian neoplasms

Relation between Ovarian Carcinoma-Associated Antigens in Tumor Tissue and Detached Cyst Fluid Cells of Patients with Ovarian Neoplasms

Aims

The expression and potential diagnostic value of ovarian carcinoma-associated antigens were estimated in different types of epithelial ovarian neoplasms. The comparison of antigenic expression was performed on solid tumor tissues and loose cyst fluid cells in individual cases of malignant and benign ovarian neoplasms.

Methods

All studies were performed using monoclonal antibodies (mAbs) against ovarian carcinoma-associated antigens (OC125, OV-TL3, OV632, 10B, 8C) by 3-step peroxidase-antiperoxidase test.

Results

All ovarian carcinoma-associated antigens were detected in most serous and endometrioid carcinomas. In mucinous carcinomas as well as in benign ovarian neoplasms these antigens were present only in some cases. Significant inter- and intratumoral immunological heterogeneity was evident; however, the antigens detectable in tissue sections were also found in detached cyst fluid cells.

Conclusions

Our results show that mAb show OV-TL3 is the best marker for endometrioid carcinomas and confirmed that mAbs OV632, OC125 and OV-TL3 could be good complementary markers for differentiating malignant and benign lesions in the ovary. The percentage content of all ovarian carcinoma-associated antigens in solid tumors and respective cyst fluid cells was comparable.

N-acetyl resonances in in vivo and in vitro NMR spectroscopy of cystic ovarian tumors

An unassigned and prominent resonance in the region from delta 2.0-2.1 ppm has frequently been found in the in vivo MR spectra of cancer patients. We demonstrated the presence of this resonance with in vivo MRS in the cyst fluid of a patient with an ovarian tumor. (1)H-NMRS on the aspirated cyst fluid of this patient confirmed the observation. A complex of resonances was observed between 2.0 and 2.1 ppm. It was also present in 11 additional ovarian cyst fluid samples randomly chosen from our biobank. The resonance complex was significantly more prominent in samples from mucinous tumors than in samples from other histological subtypes. A macromolecule (>10 kDa) was found responsible for this complex of resonances. A correlation spectroscopy (COSY) experiment revealed cross peaks of two different types of bound sialic acid suggesting that N-glycans from glycoproteins and/or glycolipids cause this resonance complex. In the literature, plasma alpha-1 acid glycoprotein (AGP), known for its high content of N-linked glycans, has been suggested to contribute to the delta 2.0-2.1 spectral region. The AGP cyst fluid concentration did not correlate significantly with the peak height of the delta 2.0-2.1 resonance complex in our study. AGP may be partly responsible for the resonance complex but other N-acetylated glycoproteins and/or glycolipids also contribute. After deproteinization of the cyst fluid, N-acetyl-L-aspartic acid (NAA) was found to contribute significantly to the signal in this spectral region in three of the 12 samples. GC-MS independently confirmed the presence of NAA in high concentration in the three samples, which all derived from benign serous tumors. We conclude that both NAA and N-acetyl groups from glycoproteins and/or glycolipids may contribute to the delta 2.0-2.1 ppm resonance complex in ovarian cyst fluid. This spectral region seems to contain resonances from biomarkers that provide relevant clinical information on the type of ovarian tumor.