Evaluation of NR4A3 immunohistochemistry (IHC) and fluorescence in situ hybridization and comparison with DOG1 IHC for FNA diagnosis of acinic cell carcinoma.

BACKGROUND: Acinic cell carcinoma (AcCC) is diagnostically challenging on fine-needle aspiration because it can mimic several other neoplasms or even normal acinar tissue. Immunopositivity for DOG1, especially circumferential membranous staining, can support the diagnosis of AcCC but is not entirely specific, and it is prone to technical and interpretive challenges on small specimens. NR4A3 (nuclear receptor subfamily 4 group A member 3) translocation and nuclear NR4A3 overexpression were recently described in the majority of AcCCs. Here, the authors evaluate the performance of NR4A3 immunohistochemistry (IHC) and NR4A3 break-apart fluorescence in situ hybridization (FISH) on cell block preparations and compare them with DOG1 IHC in distinguishing AcCC from other entities in the differential diagnosis. METHODS: The authors identified 34 cytology cell blocks with lesional cells, including 11 specimens of AcCC (2 of which derived from 1 patient and showed high-grade transformation) as well as 2 secretory carcinomas, 7 salivary duct carcinomas, 4 mucoepidermoid carcinomas, 3 oncocytomas, 3 renal cell carcinomas, and 6 specimens containing nonneoplastic salivary gland tissue. NR4A3 IHC, DOG1 IHC, and NR4A3 FISH were attempted for all cases. RESULTS: NR4A3 IHC had 81.8% sensitivity and 100% specificity for AcCC, whereas NR4A3 FISH had 36.4% sensitivity and 100% specificity, although 4 cases (3 mucoepidermoid carcinomas and 1 salivary gland tissue sample) could not be analyzed because of low cellularity. Notably, no normal acinar tissue specimens showed NR4A3 positivity by IHC or FISH. In addition, DOG1 IHC had 72.7% sensitivity and 92% specificity. CONCLUSIONS: NR4A3 IHC is highly specific for the diagnosis of AcCC and is more sensitive than DOG1 IHC and NR4A3 FISH. In addition, NR4A3 IHC performance is not improved by the inclusion of DOG1 IHC. Finally, NR4A3 positivity resolves the perennial problem of distinguishing AcCC from normal acinar tissue.

MiR-20a Promotes Prostate Cancer Cell Proliferation By Targeting NR4A3 / 中国生物化学与分子生物学报

Prostate cancer is a common malignant tumor in male patients. It is of great clinical significance to explore the pathogenesis of prostate cancer and find suitable therapeutic targets. NR4A3 is derived from the nuclear hormone receptor superfamily of steroids, and NR4A3 plays an important role in the malignant progression of a variety of tumors. However, its role in prostate cancer has not yet been elucidated. Therefore, this project intends to investigate the role of NR4A3 in prostate cancer and screen for miRNAs that target NR4A3, which may help find potential target for the diagnosis and treatment of prostate cancer. The GEPIA website predicts that NR4A3 is under-expressed in prostate cancer tissues, and qRT-PCR data confirmed downregulation of NR4A3 in prostate cancer cells (P<0. 01). CCK8 and clone formation experiments show that overexpression of NR4A3 can significantly inhibit the viability, the number and size of colonies of prostate cancer cells (P < 0. 01). The bioinformatics website predicts that NR4A3 may be the target gene of miR-20a, and qRT-PCR showed that miR-20a expression was elevated in prostate cancer cells (P<0. 01). Furthermore, dual luciferase reporter gene experiment confirmed that miR-20a can target two sites of 3′-UTR of NR4A3 (P<0. 05, P<0. 001). Western blot results showed that miR-20a can inhibit the expression of NR4A3. CCK8 experiments further found that miR-20a inhibitor can significantly reduce the viability of prostate cancer cells(P<0. 05), while miR-20a mimic has the opposite effect (P<0. 05, P<0. 01). CCK8 and clone formation experiments showed that when co-transfected with miR-20a mimic and pcDNA3. 1-NR4A3 recombinant plasmids, up-regulation of NR4A3 could partially offset the viability, the number and size of colonies of PC3 cells promoted by miR-20a mimic (P <0. 05). In summary, miR-20a promotes the proliferation of prostate cancer cells by targeting NR4A3.