Upregulated Neuro-oncological Ventral Antigen 1 (NOVA1) Expression Is Specific to Mature and Immature T- and NK-Cell Lymphomas

• Published in: Journal of pathology and translational medicine Vol. 50; no. 2; pp. 104 - 112
• Main Authors: Kim, Eun Kyung, Yoon, Sun Och, Kim, Soo Hee, Yang, Woo Ick, Cho, Yoon Ah, Kim, Soo Jeong
• Format: Journal Article
• Language: English
• Published: Korea (South) Korean Society of Pathologists, Korean Society for Cytopathology 01-03-2016; The Korean Society of Pathologists and the Korean Society for Cytopathology; Korean Society of Pathologists & the Korean Society for Cytopathology; 대한병리학회
• Subjects: Antigens; Cancer; Fibroblasts; Growth factors; Leukemia; Lymphocytes; Lymphoma; Lymphoma, T-cell; NK cell lymphoma; NOVA1; Original; Pathogenesis; Proteins; Splicing factor; Studies; 병리학; NK cell lymphoma; NOVA1; Lymphoma, T-cell; Splicing factor
• ISSN: 2383-7837; 2383-7845
• DOI: 10.4132/jptm.2016.02.08

Recent studies have revealed that the splicing factor neuro-oncological ventral antigen 1 (NOVA1) is enriched in fibroblasts and accumulated T cells of tertiary lymphoid structures. In the present study, we investigated NOVA1 expression in various subtypes of mature and immature T- and natural killer (NK)-cell lymphomas as well as in various B-cell lymphoma subtypes.
NOVA1 immunoexpression was evaluated in hyperplastic palatine tonsils (n = 20), T- and NK-cell lymphomas (n = 177), diffuse large B-cell lymphomas (n = 151), and other types of B cell lymphomas (n = 31). Nuclear staining intensity and percentage of positive tumor cells were graded. NOVA1 mRNA expression was analyzed in various lymphoma cell lines.
Tumor cells of T- and NK-cell lymphomas showed higher expression levels of NOVA1 than did normal paracortical T cells, and 56.5% of T- and NK-cell lymphoma cases showed diffuse and strong expression. The NOVA1 expression level varied according to the subtype; it was higher in angioimmunoblastic T-cell lymphoma, anaplastic lymphoma kinase (ALK)-negative anaplastic large cell lymphoma (ALCL), and T lymphoblastic leukemia/lymphoma (T-LBL), but it was lower in ALK-positive ALCL. In almost all B-cell lymphomas, NOVA1 expression was very low or negative. NOVA1 mRNA was also expressed in Jurkat, a T-LBL cell line.
The present findings suggest that NOVA1 upregulation may be involved in certain subtypes of T- and NK-cell lymphomas, but not in B-cell lymphomas. Upregulated NOVA1 expression seems to be a specific biological feature of activated T cells such as T- and NK-cell lymphomas.