Expression of Odontogenic Ameloblast-Associated Protein (ODAM) in Dental and Other Epithelial Neoplasms
We previously have communicated our discovery that the amyloid associated with calcifying epithelial odontogenic tumors is composed of N-terminal fragments of the structurally novel odontogenic ameloblast-associated protein designated ODAM. Subsequently, it was shown by other investigators that ODAM is expressed in rodent enamel organ and is likely involved in dental development. We now report that this molecule also is found in certain human tissues, principally the salivary gland and trachea, as evidenced by RNA array analysis and immunohistochemistry-utilizing antibodies prepared against synthetic ODAM-related peptides and recombinant protein. Notably, these reagents immunostained normal and malignant ameloblasts and other types of human neoplastic cells, including those of gastric, lung, and breast origin where the presence in the latter was confirmed by in situ hybridization using gene-specific molecular probes. Moreover, significant titers of anti-ODAM IgG antibodies were detected in the sera of patients with these malignancies. Our studies have provided the first evidence in humans for the cellular expression of ODAM in normal and diseased states. Based on our findings, we posit that ODAM is a developmental antigen that has an essential role in tooth maturation and in the pathogenesis of certain odontogenic and other epithelial neoplasms; further, we suggest that ODAM may serve as a novel prognostic biomarker, as well as a potential diagnostic and therapeutic target for patients with breast and other epithelial forms of cancer.
We thank P Seim for furnishing the CEOT/ameloblastoma specimen, J T Wright for the mouse dental tissue, J Hudson for the supernummary tooth follicle, Elliot K. Swab for technical assistance, and Keira Clark for manuscript preparation. This work was supported, in part, by USPHS Research Grant CA-10056 from the National Cancer Institute and the University of Tennessee Medical Center’s Physician’s Medical and Education Research Foundation.
- 9.Sugano S, et al. 2000. Hypothetical protein FLJ20513 (FLJ20513 mRNA), Accession AK000520, https://doi.org/www.ncbi.nlm.nih.gov/ Updated September 12, 2008.
- 28.Adachi J et al. (2000) Direct submission, Accession AK009298, https://doi.org/www.ncbi.nlm.nih.gov/ Updated February 11, 2008.