Anti-Helicobacter pylori, Anti-apoptotic, and Cytoprotective Effects of Threonine Synthesized from Corynebacterium glutamicum in Gastric Epithelial Cells

BACKGROUND/AIMS: Among irritants causing gastric ulcer, Helicobacter pylori (H. pylori) might be pivotal, after which eradication became essential way in either inhibiting ulcerogenesis or preventing ulcer recurrence. Since threonine is essential in either mucus synthesis or cytoprotection, we hypothesized that the dietary threonine from Corynebacterium glutamicum (C. glutamicum) can mitigate the cytotoxicity of H. pylori infection.MATERIALS AND METHODS: RGM-1 cells were challenged with 100 multiplicity of infection H. pylori for 6 hours, during which threonine alone or combination with Corynebacterium sp. was administered and compared for anti-Helicobacter, anti-inflammation, anti-oxidative, and cytoprotective actions.RESULTS: Threonine alone or combination of threonine and C. glutamicum yielded significant bacteriostatic outcomes. The increased expressions of interleukin (IL)-1β, IL-8, Cox-2, and iNOS mRNA after H. pylori infection were significantly decreased with either threonine alone or the combination of threonine and C. glutamicum. The elevated expressions of NF-kB, HIF-1a, and c-jun after H. pylori infection were all significantly decreased with the combination of threonine and broth from C. glutamicum (P < 0.05), leading to significant decreases in 2′,7′-dichlorofluorescein-diacetate (P < 0.01). Tracing further host antioxidative response, the attenuated expression of heme oxygenase-1, Nrf2, and dehydrogenase quinone-1 after H. pylori infection was significantly preserved with combination of threonine and C. glutamicum. H. pylori infection led to significant increases in apoptosis accompanied with Bcl-2 decreases and Bax increases, while the combination of threonine and C. glutamicum significantly attenuated apoptosis, in which attenuated EGF, TGF-β, and VEGF were significantly regulated, while β-catenin did not change.CONCLUSIONS: Threonine synthesized from C. glutamicum significantly alleviated the cytotoxicity of H. pylori in gastric epithelial cells.

Mediastinal Single Nodal Relapse of a Nasal Nk/T cell Lymphoma

A nasal NK/T cell lymphoma is a very aggressive form of lymphoma. Patterns of relapse after treatment have not been systematically evaluated, and mediastinal nodal relapse at a primary site has never been documented. We describe here a 40-year old man who presented with a nasal obstruction caused by a protruding mass that was identified as a nasal NK/T cell lymphoma. The initial work-up, including chest and abdominopelvic computed tomography (CT) and positron emission tomography (PET), showed no regional or distant metastasis. A CT scan performed following three cycles of chemotherapy with cyclophosphamide, doxorubicin, vincristine, and prednisolone (CHOP) showed that the mass had nearly disappeared. Radiation therapy undertaken following chemotherapy was given to the primary site. However, PET performed following radiotherapy revealed a single mediastinal lymphadenopathy, with no evidence of residual tumor in the nasal cavity. A biopsy using video-assisted thoracoscopy (VATS) showed the presence of a recurrent NK/T cell lymphoma with an immunophenotype identical to that of the primary nasal lymphoma. An additional three cycles of CHOP chemotherapy were administered, and the patient remains alive, with no evidence of disease 30 months after the initial relapse. These findings indicate that early detection with PET and prompt surgical excision with the use of VATS can lead to successful treatment of a relapsed nasal NK/T cell lymphoma.