Risk factors of medication-related osteonecrosis of the jaw: A clinical investigation.

Medication-related osteonecrosis of the jaw (MRONJ) is an intractable condition caused by drugs such as bisphosphonates and denosumab. This study investigated the changes in the incidence of MRONJ in the previous 10 years and examined the poor prognostic factors during surgery in at-risk patients. We compared 57 and 64 patients diagnosed with MRONJ at our hospital between January 2012 and December 2016 and January 2017 and December 2021, respectively. The disease stage and triggers at the time of initial diagnosis in eligible patients were investigated. Additionally, the adverse prognostic factors were examined in 166 patients at risk of MRONJ who underwent tooth extraction at our department during these 10 years. The results indicated that there was no change in the proportion of patients with osteoporosis and malignancy among those with MRONJ. The number of cases after tooth extraction decreased, and those after dental infections increased on comparing the recent 5 years and the preceding 5 years. The number of MRONJ patients receiving denosumab also increased. Denosumab was a significant post-extraction prognostic factor for delayed healing in the 166 patients at risk of MRONJ. The findings suggest that patients receiving denosumab should be closely monitored when undergoing surgery to prevent MRONJ.

TGF-ß1 induces N-cadherin expression by upregulating Sox9 expression and promoting its nuclear translocation in human oral squamous cell carcinoma cells.

Squamous cell carcinoma (SCC) is the most frequent cancer that develops in the oral cavity. Epithelial-mesenchymal transition (EMT) is known to play an important role in the process of metastasis of SCC cells. In our previous study, we demonstrated that TGF-ß1 induced EMT in the human oral SCC (hOSCC) cell line HSC-4. We also found that Slug plays an important role in suppressing E-cadherin expression and promotion of the migratory activity of HSC-4 cells. However, we also demonstrated that Slug does not participate in upregulation of N-cadherin expression, suggesting that EMT-related transcription factors other than Slug also play an important role in the process. In the present study, we aimed to elucidate how the transcription factor Sox9 affects the TGF-ß1-induced upregulation of N-cadherin expression in HSC-4 cells. We found that TGF-ß1 upregulated Sox9 expression in HSC-4 cells. In addition, Sox9 siRNA significantly abrogated the TGF-ß1-induced upregulation of N-cadherin expression and inhibited the TGF-ß1-promoted migratory activity in HSC-4 cells. We also demonstrated that TGF-ß1 upregulated the phosphorylation status of Sox9 and then promoted nuclear translocation of Sox9 from the cytoplasm, possibly resulting in an increase in N-cadherin expression. The cyclic AMP-dependent protein kinase A inhibitor H-89, which is known to suppress phosphorylation of Sox9, significantly abrogated the TGF-ß1-induced upregulation of N-cadherin expression. These results suggested that TGF-ß1 induced N-cadherin expression by upregulating Sox9 expression and promoting its nuclear translocation, which results in EMT progression in hOSCC cells.

A pilot study of the clinical evidence for the methodology for prevention of oral mucositis during cancer chemotherapy by measuring salivary excretion of 5-fluorouracil.

Objective to re-examine measures to prevent oral mucositis caused by drugs in head and neck cancer patients during cancer treatment by measuring salivary excretion of 5-fluorouracil. Saliva, blood, and urine were simultaneously collected from oral cancer patients and breast cancer patient at the point in time of before, during, and after the administration of 5-FU, then the 5-FU levels of the samples were quantitatively analysed using LC-MS/MS. In all patients, the 5-FU levels in saliva and serum peaked at 30 min to 3 h after the start of 5-FU treatment, and high levels were maintained throughout the administration of the drug. With regard to urinary 5-FU levels, they remained high from 3 to 120 h after the start of 5-FU treatment. After the completion of 5-FU treatment, even though it not appeared in the patients' serum and urine promptly, 5-FU was detected in saliva at 12 h after the completion of 5-FU treatment in one oral cancer patient and at 48 h after the completion of 5-FU treatment in the breast cancer patient. It was suggested that the level of hydration after the completion of chemotherapy may be involved in the differences in 5-FU excretion.