BACKGROUND: The Epstein‐Barr virus (EBV)‐encoded EB nuclear antigen 1 (EBNA1) protein is required for maintenance and transmission of the viral episome in EBV‐infected cells. The objective of this study was to investigate the role of EBNA1 protein in nasopharyngeal carcinoma (NPC).METHODS: Tissue samples from 48 patients with NPC and 12 patients with chronic nasopharyngitis were subjected to immunohistochemical analysis of EBNA1 expression. EBNA1 combinational DNA was used to overexpress EBNA1 protein in NPC cell lines to assess tumor cell epithelial‐mesenchymal transition (EMT), colony formation, migration and invasion, and gene expression.RESULTS: EBNA1 protein was highly expressed in NPC tissue specimens, and its expression was associated with NPC lymph node metastasis. EBNA1 expression affected NPC cell morphology and the expression of EMT markers in vitro. Furthermore, overexpression of EBNA1 inhibited the expression of microRNA 200a (miR‐200a) and miR‐200b and, in turn, up‐regulated expression of their target genes, zinc finger E‐box binding homeobox 1 ( ZEB1) and ZEB2, which are well known mediators of EMT. In addition, EBNA1‐regulated miR‐200a and miR‐200b expression was mediated by transforming growth factor‐β1.CONCLUSIONS: The current findings provided novel insight into the vital role of EBNA1 in manipulating a molecular switch of EMT in EBV‐positive NPC cells. Cancer 2014;120:363–372. © 2013 American Cancer Society.

Objective: Intrauterine adhesion (IUA) is one of the major causes of refractory secondary infertility, especially in regions and countries with high abortion rates. In this study, we used the mouse IUA model to evaluate the feasibility of the organoids, a 3D cell structure derived from endometrial tissue, as grafts for the treatment of post-traumatic endometrial regeneration disorders. Methods: The isolated and cultured endometrial organoid was transplanted into the model IUA uterus by the hydrogel scaffold method. Results: The cultured endometrial organoids were transplanted into the basal layer of the damaged endometrium for 28 days. They were completely implanted and grew normally. They not only reconstructed the structural integrity of the endometrial epithelium but also realized the functional repair of the endometrium through differentiation cultures and secretory functions. Conclusion: For severe IUA, this method may be better than stem cell transplantation. These findings provide useful insights into the use of endometrial organoid regeneration in the treatment of injury repair.

Background: Recurrent nasopharyngeal carcinoma (NPC) remains a major challenge for clinicians and scientists. Tumor organoid is a revelational disease model that highly resembled the heterogeneity and histopathological characteristics of original tumors. This study aimed to optimize the modeling process of patient-derived NPC organoids (NPCOs), and establish a living-biobank of NPCs to study the mechanism and explore the more effective treatment of the disease. Methods: Sixty-two fresh NPC tissue samples and 15 normal mucosa samples were collected for 3-dimensional (3D) organoid culture. The organoids were confirmed using hematoxylin and eosin assays. The expression levels of CD133, CD44, BMI-1, and Epstein-Barr virus (EBV)-encoded small RNAs (EBERs) were detected by immunohistochemistry (IHC) and in situ hybridization (ISH). Recurrent NPCOs were frozen in liquid nitrogen for 6 months and then resuscitated and passaged. Results: We identified a novel two-step enzymatic strategy for the treatment of NPC and nasal mucosa specimens and an optimal medium for culturing NPCOs and nasal mucosa organoids (NMOs). Organoid cultures were generated from 34 primary NPC samples, 28 recurrent NPC samples, and 15 normal mucosa samples. The success rates for primary NPCO, recurrent NPCO, and NMO formation were 47.06%, 81.25%, and 86.5%, respectively. All the NPCOs were EBER positive and CK7 negative. Recurrent NPCOs had higher expressions of stem cell markers, including BMI-1, CD44, and CD133. Additionally, recurrent NPCOs could be cultured to passage 4 and frozen and revived repeatedly, while primary NPCOs were challenging to culture. Conclusions: In summary, we successfully established a living biobank using the NPCO model, which has enormous potential in basic and clinical research on NPC.

Nasopharyngeal carcinoma (NPC) causes severe oncogenic lesions in the nasopharynx. CD47, a transmembrane integrin‐associated protein, plays a key role in the ability of tumor cells to escape phagocytosis, working as an immune checkpoint in the immune response. Besides this role, CD47 has been reported to regulate cell proliferation and migration. The present study addresses the relationship between CD47 and microRNA‐200a and examines their regulatory mechanisms in NPC. Bioinformatics analyses and dual‐luciferase reporter assays were used to confirm the putative relationship between miR‐200a and CD47, and their interaction was further detected using western blotting and RT‐PCR. Further, results showed that miR‐200a affect NPC cell proliferation, migration, and invasion by regulating CD47. A cell phagocytosis assay showed that miR‐200a and a CD47 monoclonal antibody increased the sensitivity of NPC cells to macrophage phagocytosis by inhibiting the functions of CD47. Additionally, miR‐200a expression was suppressed and CD47 expression increased in both clinical NPC tissues and cell lines. Taken together, these results show the miR‐200a/CD47 combination as a potential therapeutic for treatment of NPC.