A novel stem cell associated marker identified by monoclonal antibody HESC5:3 differentiates between neoplastic lesions in follicular thyroid neoplasms

The expression and prognostic value of stem cell markers Bmi-1, HESC5:3, and HES77 in human papillomavirus-positive and -negative oropharyngeal squamous cell carcinoma

Human papillomavirus is detected in over 50% of oropharyngeal squamous cell carcinomas. Human papillomavirus-positive oropharyngeal squamous cell carcinomas differ from human papillomavirus-negative tumors, and both expression patterns are classified as distinct entities. The Bmi-1 oncogene is a well-known member of the mammalian polycomb-group family. HESC5:3 and HES77 are newly developed monoclonal antibodies produced against undifferentiated embryonic stem cells. Our aim was to explore their roles in both human papillomavirus-positive and -negative oropharyngeal squamous cell carcinomas. Our cohort comprised 202 consecutive oropharyngeal squamous cell carcinoma patients diagnosed and treated with curative intent. We used tissue microarray tumor blocks to study the immunohistochemical expression of Bmi-1, HESC5:3, and HES77. We compared the expressions of these stem cell markers with p16 immunoexpression and human papillomavirus status, as well as with other characteristics of the tumor, and with patients' clinical data and follow-up data. Human papillomavirus- and p16-positive tumors expressed less Bmi-1 and more HESC5:3 than the negative tumors. HES77 expression was high in human papillomavirus-positive oropharyngeal squamous cell carcinoma, but it did not correlate with p16 positivity. In our multivariable model, Bmi-1 and HESC5:3 were still associated with human papillomavirus, but the association between human papillomavirus and HES77 remained absent. In conclusion, Bmi-1, HESC5:3, and HES77 may have a different role in human papillomavirus-positive and human papillomavirus-negative tumors. There was no correlation between Bmi-1, HESC5:3, and HES77 expression and survival.

APLP2, RRM2, and PRC1: New Putative Markers for the Differential Diagnosis of Thyroid Follicular Lesions

BACKGROUND

Current methods based on fine-needle aspiration biopsy (FNAB) are not sufficient to distinguish among follicular thyroid lesions, follicular adenoma (FA), follicular thyroid carcinoma (FTC), and the follicular variant of papillary thyroid cancer (FVPTC). Furthermore, none of the immunohistochemical markers currently available are sensitive or specific enough to be used in the clinical setting, necessitating a diagnostic hemithyroidectomy. The aim of this study was to identify proteins of value for differential diagnosis between benign and malignant thyroid follicular lesions.

METHODS

This retrospective analysis is based on an assessment of the immunoexpression of 19 proteins on 81 benign thyroid lesions (FA) and 50 malignant tumors (FTC/FVPTC). The resulting expression profile allowed the design of a scoring system model to improve the differential diagnosis of benign and malignant thyroid lesions. The model was validated using an independent series of 69 FA and 40 FTC and an external series of 40 nodular hyperplasias, and was further tested in a series of 38 FNAB cell blocks.

RESULTS

A model based on the nuclear and cytoplasmic expression of APLP2, RRM2, and PRC1 discriminated between benign and malignant lesions with 100% sensitivity in both main and validation groups, with specificities of 71.3% and 50.7%, respectively. For the nodular hyperplasia series, specificity reached 94.8%. Finally, in FNAB samples, the sensitivity was 100% and the specificity was 45% for discrimination between benign and malignant lesions.

CONCLUSIONS

These findings suggest that the identified APLP2, RRM2, and PRC1 signature could be useful for distinguishing between benign (FA) and malignant (FTC and FVPTC) tumors of the thyroid follicular epithelium.