A Potential Role for Immunotherapy in Thyroid Cancer by Enhancing NY-ESO-1 Cancer Antigen Expression

Abstract

Background: NY-ESO-1 is one of the most immunogenic members of the cancer/testis antigen family and its levels can be increased after exposure to demethylating and deacetylating agents. This cytoplasmic antigen can serve as a potent target for cancer immunotherapy and yet has not been well studied in differentiated thyroid cancer cells. Methods: We studied the baseline expression of NY-ESO-1 messenger RNA and protein before and after exposure to 5-aza-2¢-deoxycytidine (DAC) (72 hours) in a panel of thyroid cancer cell lines using quantitative polymerase chain reaction and Western blot. HLA-A2 +, NY-ESO-1 + thyroid cell lines were then co-cultured with peripheral blood lymphocytes transduced with NY-ESO-1 specific T-cell receptor (TCR) and assayed for interferon-gamma and Granzyme-B release in the medium. SCID mice injected orthotopically with BCPAP cells were treated with DAC to evaluate for NY-ESO-1 gene expression in vivo. Results: None of the thyroid cancer cell lines showed baseline expression of NY-ESO-1. Three cell lines, BCPAP, TPC-1, and 8505c, showed an increase in NY-ESO-1 gene expression with DAC treatment and were found to be HLA-A2 positive. DAC-treated target BCPAP and TPC-1 tumor cells with up-regulated NY-ESO-1 levels were able to mount an appropriate interferon-gamma and Granzyme-B response upon co-culture with the NY-ESO-1-TCR-transduced peripheral blood lymphocytes. In vivo DAC treatment was able to increase NY-ESO-1 expression in an orthotopic mouse model with BCPAP cells. Conclusion: Our data suggest that many differentiated thyroid cancer cells can be pressed to express immune antigens, which can then be utilized in TCR-based immunotherapeutic interventions.

Characterization of Thyroid Cancer Cell Lines in Murine Orthotopic and Intracardiac Metastasis Models

“…In the orthotopic model, studies from our group and others have observed an aggressive thyroid cancer model with lung metastasis in immunocompromised mice with the 8505C cell line [33, 32, 8, 13, 14, 31, 5, 24, 4], and the data presented here are consistent with the findings of these prior studies (Fig. 3).…”

“…This may have been due to masking from a strong signal from the primary thyroid tumor, low sensitivity to detect metastasis in vivo using this modality, or low volume of the lung micrometastases. The excellent take rate of BCPAP cells in the orthotopic model, however, support previously reported studies which detail and exploit its reliable tumor formation rate and large tumor size to study potential thyroid cancer therapies and disease mechanisms [14, 8, 4, 13]. …”

“…Clayman and colleagues also reported that MDA-T41 cells, with or without selection in soft agar, fail to form tumors when orthotopically implanted in nude mice[17]. Similarly, previously published reports by our group and others found that TPC-1 cells failed to form significant tumors in the orthotopic model in immunocompromised mice [14, 4]. Others, however, do report some success with TPC-1 cells in an orthotopic model.…”

“…This frequency of pulmonary metastasis may have been underestimated, however, due to incomplete sectioning of the paraffin-embedded lung tissue. Gunda and colleagues described the orthotopic use of BCPAP cells in SCID mice, which reproducibly produced large tumors by 8 weeks post-injection, but without evidence of metastasis, though the methodology for this determination was not reported [14]. Lung metastases were not typically apparent on weekly IVIS imaging analysis in any of our studies, but rather were apparent on ex vivo imaging analysis or by histologic examination of lung tissues.…”

Noninvasive In Vivo Imaging and Biologic Characterization of Thyroid Tumors by ImmunoPET Targeting of Galectin-3

“…Anaplastic thyroid carcinoma cells FRO82-1 (ATCC), follicular thyroid carcinoma cells WRO82-1 (kindly provided by Dr. Silvia Soddu, National Cancer Institute Regina Elena, Rome, Italy), and papillary thyroid carcinoma cells BCPAP (DSMZ-German Collection of Microorganisms and Cell Cultures), were described previously (26)(27)(28). Cells were cultured in complete RPMI1640 culture medium in standard condition (29) and tested for integrity, Gal-3 expression, and tumorigenicity before each experimental procedure as reported elsewhere.…”