Mitsuharu Aga

Warthin's tumor associated with IgG4-related disease

Immunoglobulin G4-related disease (IgG4-RD) is an inflammatory condition associated with elevated serum IgG4 levels and tissue infiltration by IgG4-expressing plasma cells. Several inflammatory conditions associated with IgG4-RD have been reported. Warthins tumor is a benign parotid gland tumor consisting of oncocytic epithelial cells and lymphoid stroma containing lymphoid follicles with reactive germinal centers. This is the first report describing a case of Warthins tumor with possible involvement of IgG4-RD. The patient was a 71-year-old man presenting with swollen right parotid and bilateral submandibular glands. He had a history of a Warthins tumor of the left parotid gland, autoimmune pancreatitis, and an inflammatory abdominal aortic aneurysm. Laboratory tests revealed a high serum IgG4 level. Histological examination of the resected parotid gland showed a Warthins tumor and a nodule showing severe lymphocytic infiltration containing many IgG4-positive plasma cells. This case shows the possible involvement of Warthins tumor with IgG4-RD.

Immunoglobulin class switching to IgG4 in Warthin tumor and analysis of serum IgG4 levels and IgG4-positive plasma cells in the tumor

We previously reported a case of immunoglobulin (Ig)G4-related immune inflammation in Warthin tumor. Increased serum IgG4 levels and tissue infiltration of IgG4-positive plasma cells are characteristics of IgG4-related disease (IgG4-RD), a newly emerging clinicopathological entity. However, the relationship between IgG4-RD and Warthin tumor remains to be elucidated. We aimed to investigate the involvement of systemic and local IgG4 production and class-switch recombination in Warthin tumor. We examined serum IgG4 levels and also analyzed the involvement of IgG4-positive plasma cells in Warthin tumors (18 cases) compared with those of pleomorphic adenomas (19 cases) as controls. Furthermore, in specimens of Warthin tumors (3 cases), pleomorphic adenomas (2 cases), and IgG4-RDs (2 cases), we examined messenger RNA expression of activation-induced cytidine deaminase, IgG4 germline transcripts and productive IgG4 by reverse transcription polymerase chain reaction. Serum IgG4 levels were increased in 5 of 18 Warthin tumors and not in any of the 19 pleomorphic adenomas. Infiltration of IgG4-positive plasma cells was detected in 4 Warthin tumors and none in the pleomorphic adenomas. Moreover, activation-induced cytidine deaminase, IgG4 germline transcripts, and productive IgG4 messenger RNA were found to be expressed in 2 of 3 Warthin tumors as well as IgG4-RDs by reverse transcription polymerase chain reaction, but not in pleomorphic adenomas. In conclusion, immunoglobulin class switching to IgG4 may be involved in the pathogenesis of Warthin tumor, and it is possible that certain inflammatory background with an immune reaction is involved in the pathogenesis of Warthin tumor.

Modulation of the tumor microenvironment by Epstein‐Barr virus latent membrane protein 1 in nasopharyngeal carcinoma

Latent membrane protein 1 (LMP1) is a primary oncogene encoded by the Epstein‐Barr virus, and various portions of LMP1 are detected in nasopharyngeal carcinoma (NPC) tumor cells. LMP1 has been extensively studied since the discovery of its transforming property in 1985. LMP1 promotes cancer cell growth during NPC development and facilitates the interaction of cancer cells with surrounding stromal cells for invasion, angiogenesis, and immune modulation. LMP1 is detected in 100% of pre‐invasive NPC tumors and in approximately 50% of advanced NPC tumors. Moreover, a small population of LMP1‐expressing cells in advanced NPC tumor tissue is proposed to orchestrate NPC tumor tissue maintenance and development through cancer stem cells and progenitor cells. Recent studies suggest that LMP1 activity shifts according to tumor development stage, but it still has a pivotal role during all stages of NPC development.

Potential Interest in Circulating miR-BART17-5p As a Post-Treatment Biomarker for Prediction of Recurrence in Epstein-Barr Virus-Related Nasopharyngeal Carcinoma.

Objectives Epstein-Barr virus (EBV)-related micoRNAs (miRNAs), BamHI-A rightward transcripts (BART)-miRNAs, are released in a stable form from viable cells, which are abundant in patients with EBV-positive nasopharyngeal carcinoma (NPC). We estimated copy numbers of circulating miR-BART2-5p, miR-BART17-5p, and miR-BART18-5p as well as BamHI-W DNA as biomarkers. Materials and Methods Serums from 31 EBV-positive (confirmed by in situ hybridization for EBV-encoded small RNAs) NPC patients and 40 non-NPC controls were analyzed. Among the 31 NPC patients, serums at the initial diagnosis and three months after treatment were obtained from 20 patients, and serums only at three months after treatment were obtained from 11 patients. Results The sensitivity/specificity of circulating BamHI-W DNA, miR-BART2-5p, miR-BART17-5p, and miR-BART18-5p for the diagnosis of NPC before treatment were 100 / 100, 85 / 85, 60 / 95, and 25 / 100%, respectively. For BamHI-W DNA, NPC patients with stage IV disease had significantly higher copy numbers than those with I-III. Copy numbers decreased significantly post-treatment. In contrast, copy numbers of the three BART-miRNAs showed no significant correlation with the clinical stage at diagnosis or any significant post-treatment change. After treatment, BamHI-W DNA and miR-BART17-5p were detected in 5 and 6 cases out of 11 patients with recurrent or residual tumors, respectively. However, BamHI-W DNA and miR-BART17-5p were absent in all 20 patients without relapse or residual tumors. Conclusion The copy number of circulating BamHI-W DNA is a more useful biomarker for the initial diagnosis of NPC than the three BART-miRNAs examined. Post-treatment detection of miR-BART17-5p is a potential biomarker of a poor prognosis.

Expression of interferon regulatory factor 7 correlates with the expression of Epstein–Barr Virus latent membrane protein 1 and cervical lymph node metastasis in nasopharyngeal cancer

Interferon regulatory factor 7 (IRF7) has oncogenic properties in several malignancies such as Epstein–Barr virus (EBV)‐associated lymphoma. However, there is no evidence whether IRF7 is associated with the oncogenesis of nasopharyngeal cancer (NPC), the pathogenesis of which is closely associated with EBV. Herein, we report that expression of IRF7 was increased in normal nasopharyngeal cells that expressed the EBV principal oncoprotein, latent membrane protein 1 (LMP1). In addition, IRF7 was mainly expressed in the nucleus in both normal nasopharyngeal cells and nasopharyngeal cancer cells that expresses LMP1. On immunohistochemical analysis, IRF7 was predominantly localized in the nucleus in biopsy samples of NPC tissues. In total, IRF7 expression was detected with 36 of 49 specimens of these tissues. Furthermore, the expression score of IRF7 correlated with the expression score of LMP1. Moreover, the expression score of IRF7 is associated with cervical lymph‐node metastasis, which reflects the highly metastatic nature of this cancer. Taken together, our results suggest that expression of IRF7 is one of the metastatic effectors of LMP1 signalling in EBV‐associated NPC.

Siah-1 is associated with expression of hypoxia-inducible factor-1α in oral squamous cell carcinoma

OBJECTIVE Hypoxia-inducible factor-1 (HIF-1) is a heterodimeric basic helix-loop-helix transcription factor composed of the HIF-1α and HIF-1β subunits. HIF-1 is a central regulator of responses to hypoxia; it enhances metastasis-related factors such as matrix metalloproteinases and vascular endothelial growth factor (VEGF). We have reported critical roles for HIF-1α in tumor microenvironments, and oncogenic properties of HIF-1α have been suggested in malignancies. Seven in absentia homologue (Siah) appeared to upregulate HIF-1 production, which prompted us to investigate the Siah association with HIF-1α expression in oral squamous cell carcinoma (OSCC). METHODS Samples from fifty-five patients with OSCC were evaluated by immunohistochemistry for the protein expressions of Siah-1 and -2, HIF-1α, and VEGF. The expression levels of each protein and clinicopathological data were statistically analyzed. RESULTS Siah-1 and, Siah-2, HIF-1α, and VEGF were immunolocalized on the cell membranes and cytoplasm of the tumor cells. The expression of Siah-1 showed a linear dependence on the expression of HIF-1α (r=0.627, p<0.001). In 17 cases of the large tumor size category (T3 and 4), the mean Siah-1 expression score was significantly higher than in 41 cases of the small tumor size category (T1 and 2; p=0.001). In addition, in 16 cases of the lymph node metastasis-positive category (N1-3), the mean Siah-1 expression score was significantly higher than that in 42 cases of the lymph node metastasis-negative category (N0, p=0.001). CONCLUSION These results suggested that the expressions of Siah-1 and HIF-1α were clearly correlated in OSCC. Moreover, Siah-1 appears to be correlated with clinicopathological data, particularly tumor size.

T-status and an oral fluoropyrimidine, S-1, adjuvant chemotherapy are prognostic factors in reduced-RADPLAT for resectable hypopharyngeal cancer

Abstract Conclusion: Reduced-RADPLAT for HPC achieved comparative survival and locoregional control rates with lower toxicities compared with concurrent chemoradiotherapies including original RADPLAT. S-1 adjuvant chemotherapy showed a survival benefit. Objectives: To evaluate the efficacy and toxicities of targeted intra-arterial (IA) infusion of cisplatin with concurrent radiotherapy with a reduced dose (reduced-RADPLAT) for resectable hypopharyngeal cancer (HPC). Methods: Between 1999–2012, 50 patients with stage II–IVA HPC primarily treated by reduced-RADPLAT were analyzed. They were treated by 2–5 courses of IA cisplatin infusion (100 mg per body) with simultaneous systemic infusion of sodium thiosulfate concurrent with conventional radiotherapy (66–70 Gy). After 2003, S-1, an oral fluoropyrimidine, adjuvant chemotherapy was administered to all eligible patients. Results: During a median follow-up of 48.6 months, the estimated 3- and 5-year overall survival (OS), progression-free survival (PFS), locoregional control, and laryngoesophageal dysfunction-free survival (LEDFS) rates were 76.0% and 62.0%, 58.0% and 50.0%, 66.0% and 62.0%, and 56.0% and 54.0%, respectively. Grade 3 toxicities were observed in 30.0%. No patient had grade 4 or higher toxicities. No patient required tube feeding or tracheotomy at 3 months after treatment. T4-lesions and S-1 administration were significant factors predicting poor and good OS, PFS, and LEDFS, respectively.