No abstract

Objectives We had previously found that reduced folate carrier (RFC; SLC19A1) is mainly involved in an influx of transport of methotrexate (MTX), a folate analogue, using alveolar epithelial A549 cells. Therefore, we examined MTX uptake in NCl‐H441 (H441) cells, another in vitro alveolar epithelial model, focusing on the localization of RFC in the present study. Methods Transport function of RFC in H441 cells was studied using [3H]MTX. Key findings The uptake of MTX was increased remarkably after pretreatment of the cell monolayer with ethylenediaminetetraacetic acid (EDTA) in H441 cells but not in A549 cells, indicating the contribution of the basolaterally located transporter. In addition, folic acid and thiamine monophosphate, RFC inhibitors, inhibited the uptake of MTX from the basolateral side of the H441 cells. In order to compare the function of RFC on the apical and basolateral sides of the cells, the uptake of MTX from each side was examined using a Transwell chamber. Intracellular MTX amounts from the basolateral side were found to be significantly higher than those from the apical side. Conclusions These findings suggest that the distribution of MTX in the lung alveolar epithelial cells may be mediated by basolaterally located RFC in alveolar epithelial cells.

We encountered a case of sclerosing odontogenic carcinoma that was difficult to diagnose. The patient was a 57-year-old man who presented with paralysis of the mental region. At his first visit, he was found to have a swelling in the right alveolar part of the mandible, oppressive pain, and dysesthesia of the mental region and tongue. Panoramic radiography revealed a diffuse and poorly marginated radiolucency extending from the right lower canine to the right mandibular ramus. After preoperative chemotherapy, we performed right hemimandibulectomy, selective neck dissection with removal of level Ⅰ lymph nodes, and reconstruction with a fibular osteoseptocutaneous flap with the patient under general anesthesia. Histopathologic examination of the resected specimens led to the diagnosis of sclerosing odontogenic carcinoma. The patient had an uneventful course without any evidence of recurrence 38 months after surgery. : sclerosing odontogenic carcinoma (硬化性歯原性癌) ，WHO classification (WHO 分類) ， immunohistochemical staining (免疫組織化学染色) 1) 東京医科歯科大学大学院医歯学総合研究科顔面頸部機能 再建学講座顎顔面外科学分野 (主任：依田哲也教授) 2) 東京医科歯科大学大学院医歯学総合研究科口腔機能再構 築学講座口腔病理学分野 (主任：池田 通教授) 1)