Inorganic polyphosphate [Poly(P)] is especially prevalent in osteoblasts. We tested the hypothesis that Poly(P) stimulates osteoblastic differentiation and polyphosphate metabolism for bone formation. The osteoblast-like cell line, MC 3T3-E1, was cultured with Poly(P), and gene expression was evaluated by real-time reverse-transcription polymerase chain-reaction. Phosphatase activity and extracellular matrix mineralization were also determined. The role of Poly(P) was assessed in a beagle dog alveolar bone regeneration model. Poly(P) increased osteocalcin, osterix, bone sialoprotein, and tissue non-specific alkaline phosphatase gene expression, with a high level of end-polyphosphatase activity, resulting in low-chain-length Poly(P), inorganic pyrophosphate, and inorganic phosphate production. MC3T3-E1 cells differentiated into mature osteoblasts and showed expression of ectonucleotide pyrophosphatase phosphodiesterase 1, while mouse progressive ankylosis gene expression remained unchanged. Promotion of alveolar bone regeneration was observed in Poly(P)-treated beagle dogs. These findings suggest that Poly(P) induces osteoblastic differentiation and bone mineralization, and acts as a resource for mineralization.

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The aim of the present study was to clarify whether ATP binding cassette transporters are refractory factors in head and neck cancer chemotherapy. For in vitro and in vivo chemotherapeutic studies, we employed a human salivary gland adenocarcinoma cell line (HSY) and a human oral squamous cell carcinoma cell line (SCCSK) with vincristine (VCR) at clinically equivalent doses. Western blot analysis, reverse transcription‐ polymerase chain reaction, in vivo evaluation in xenograft models inoculated with cultured carcinoma cell line and drug efflux analysis were performed. VCR‐treated SCCSK and HSY cells, as well as xenografted SCCSK and HSY cells in tumor‐bearing nude mice, were found to express MDR1/ABCB1 and MRP1/ABCC1. In addition to MDR1 and MRP1 mRNA, HSY/VCR and its cloned cells expressed MRP7/ABCC10 mRNA, but SCCSK/VCR did not express MRP7. Furthermore, drug resistance to VCR and docetaxel decreased in HSY/VCR in the presence of a competitive MRP7 inhibitor, 17‐beta‐estradiol‐(17‐beta‐D‐glucuronide). These results indicate that MDR1 and MRP1 expression are refractory factors in head and neck cancer chemotherapy and suggest that induction of MRP7 expression is involved in drug resistance in salivary gland adenocarcinomas.

We report a case of actinomycosis affecting the buccal mucosa in a patient with systemic lupus erythematosus. A 66-year-old woman with systemic lupus erythematosus presented with a swelling of the lower lip and left cheek. We suspected a salivary gland adenocarcinoma on inspection, palpation, and evaluation of the serum CA19-9 level. Enhanced computed tomography showed the location of the tumor. Other imaging techniques, including magnetic resonance imaging and ultrasonic tomography, were employed to support the clinical diagnosis. We performed a biopsy and histopathologically diagnosed the lesion as actinomycosis. The patient underwent abscess incision several times and received intravenous injections of 3g ABPC daily for 7 days, followed by 400 mg of oral ABPC for 4 weeks. There was no sign of recurrence after treatment. Imaging methods were considered useful for the clinical diagnosis of actinomycosis.