Thyroid peroxidase (TPO) expressed in thyroid and breast tissues shows similar antigenic properties

• Published in: PloS one Vol. 12; no. 6; p. e0179066
• Main Authors: Godlewska, Marlena, Arczewska, Katarzyna D, Rudzińska, Magdalena, Łyczkowska, Anna, Krasuska, Wanda, Hanusek, Karolina, Ruf, Jean, Kiedrowski, Mirosław, Czarnocka, Barbara
• Format: Journal Article
• Language: English
• Published: United States Public Library of Science 02-06-2017; Public Library of Science (PLoS)
• Subjects: Antibodies; Antigenicity; Antigens; Autoantigens - analysis; Autoantigens - genetics; Autoimmunity; Binding sites; Biochemistry; Biology and Life Sciences; Biomarkers; Blotting, Western; Breast - pathology; Breast cancer; Breast Neoplasms - genetics; Breast Neoplasms - pathology; Cancer; Female; Gene Expression Regulation, Neoplastic; Health education; Health risk assessment; Hormones; Humans; Hypothyroidism; Immunoglobulins; Immunohistochemistry; Iodide peroxidase; Iodide Peroxidase - analysis; Iodide Peroxidase - genetics; Iron-Binding Proteins - analysis; Iron-Binding Proteins - genetics; Medicine and Health Sciences; Middle Aged; Molecular biology; Monoclonal antibodies; Oncology; Patients; Peroxidase; Physiology; Proteins; Research and Analysis Methods; Thyroid; Thyroid cancer; Thyroid diseases; Thyroid gland; Thyroid Gland - pathology; Tissues; Womens health
• ISSN: 1932-6203; 1932-6203
• DOI: 10.1371/journal.pone.0179066

Thyroid peroxidase (TPO) is essential for physiological function of the thyroid gland. The high prevalence of thyroid peroxidase antibodies (TPOAbs) in patients with breast cancer and their protective role had previously been demonstrated, indicating a link between breast cancer and thyroid autoimmunity. Recently, TPO was shown to be present in breast cancer tissue samples but its antigenicity has not been analyzed.
In this study, we investigated TPO expression levels in a series of fifty-six breast cancer samples paired with normal (peri-tumoral) tissue and its antigenic activity using a panel of well-characterized murine anti-human TPOAbs.
We have shown that TPO transcripts were present in both normal and cancer tissue samples, although the amounts in the latter were reduced. Additionally, we observed that TPO levels are lower in more advanced cancers. TPO protein expression was confirmed in all tissue samples, both normal and cancerous. We also found that the antigenicity of the immunodominant regions (IDRs) in breast TPO resembles that of thyroid TPO, which is crucial for effective interactions with human TPOAbs.
Expression of TPO in breast cancer together with its antigenic activity may have beneficial effects in TPOAb-positive breast cancer patients. However, further studies are needed to confirm the beneficial role of TPOAbs and to better understand the underlying mechanism.