[Effects of miR-31-5p on HIF-1α/BNIP3 signaling pathway and the expression of osteoblast-related factors of dental pulp stem cells].

PURPOSE: To investigate the effects of microRNA-31-5p (miR-31-5p) on the signal pathway of hypoxia inducible factor-1α (HIF-1α)/Bcl-2/adenovirus E1B 19-kDa-interacting protein 3(BNIP3) and the expression of osteoblast-related factors of dental pulp stem cells(DPSCs). METHODS: Human dental pulp stem cells (DPSCs) were cultured in vitro and divided into the control group (no transfection), mimic NC group (transfected with negative control-miR-31-5p), miR-31-5p mimic group (transfected with hsa-miR-31-5p mimic), siRNA NC group (transfected with nonsense siRNA) and miR-31-5p siRNA group (transfected with miR-31-5p siRNA).The expressions of miR-31-5p, HIF-1α, BNIP3, alkaline phosphatase(ALP) and Runt-related transcription factor-2(Runx2) mRNA in DPSCs were detected by real-time fluorescence quantitative PCR; the proliferation of DPSCs was detected by MTT; ALP activity of DPSCs was detected by ALP activity test kit; and the protein expressions of HIF-1α, BNIP3 and Runx2 in DPSCs were detected by Western blot. Statistical analysis was carried out with SPSS 24.0 software package. RESULTS: Compared with the control group and mimic NC group, the A value, ALP mRNA expression level and activity, Runx2 mRNA and protein expression levels of DPSCs in miR-31-5p mimic group were significantly lower (P＜0.05), ALP staining decreased significantly, and the expression levels of miR-31-5p mRNA, HIF-1α, BNIP3 mRNA and HIF-1α, BNIP3, Beclin1 protein were significantly higher (P＜0.05). Compared with the control group and siRNA NC group, the A value, ALP mRNA expression level and activity, Runx2 mRNA and protein expression levels of DPSCs in miR-31-5p siRNA group were significantly higher (P＜0.05), ALP staining enhanced significantly, and the expression levels of miR-31-5p mRNA, HIF-1α, BNIP3 mRNA and HIF-1α, BNIP3, Beclin1 protein were significantly lower(P＜0.05). CONCLUSIONS: MiR-31-5p may inhibit the expression of osteoblast-related factors of DPSCs, and activating HIF-1α/BNIP3 signaling pathway.

[Dental pulp stem cells modified by HIF-1α can differentiate into blood vessels].

PURPOSE: To investigate the method of differentiating dental pulp stem cells (DPSCs) modified by HIF-1α into blood vessels. METHODS: DPSCs were extracted from teeth samples from 20 patients and were identified by Strol-1 and CD146. DPSCs were divided into experimental group and control group according to DPSCs were modified by HIF-1α not or. HIF-1α-mRNA expression was detected by RT-PCR. HIF-1α, VEGF, SDF-1, Ang-2 and PDGF expression were detected using Western blot in different time after culture for 1 d, 4 d, 7 d and 14 d. Statistical analysis was carried out with SPSS 16.0 software package. RESULTS: Most DPSCs appeared round, oval under phase-contrast microscopy. CD146 and Strol-1 showed green fluorescence. HIF-1α and HIF-1α-mRNA expression became higher with time passing and the difference was statistically significant (P<0.05). Compared with the control group, HIF-1α protein and mRNA increased obviously in the experimental group 1d, 4d, 7d and 14d after transfection, and the difference was statistically significant (P<0.05). The level of VEGF, SDF-1, Ang-2 and PDGF in the control group was changed unconspicuously, and the expression was not different at different times (P>0.05). The level of VEGF, SDF-1, Ang-2 and PDGF in the exprimental group increased, and the difference was statistically significant between different time points(P<0.05). Compared with the control group, the level of VEGF, SDF-1, Ang-2 and PDGF in the experimental group was higher 1 d, 4 d, 7 d and 14 d after transfection, respectively, and the difference was statistically significant(P<0.05). CONCLUSIONS: DPSCs modified by HIF-1α gene can successfully induce vascular differentiation in vitro, which provides foundation for further angioplasty.

Intraosseous mucoepidermoid carcinoma of jaws: report of 24 cases.

OBJECTIVE: Intraosseous mucoepidermoid carcinoma of jaws is rare, and management of the disease remains poorly understood. The aim of this study was to assist the diagnosis and treatment of the tumor. STUDY DESIGN: The records of clinical data and follow-up information were collected from 1996 to 2010 and retrospectively analyzed for clinical features, surgical intervention, and prognosis. RESULTS: Of 24 cases, 15 were male, and the average age was 47.33 years. The clinical presentation of this tumor varied. For primary lesions and neck nodes, radical surgery was performed; radiotherapy or chemotherapy was administered after operation. The survival rate of all patients was 66.7%. The average survival period was 53.3 months after surgery. CONCLUSIONS: Diagnosis should be based on clinical and pathologic manifestations, surgery is the first choice for patient treatment, and radiotherapy may improve prognosis and therefore should be recommended in postoperative period.

Clinical management of peripheral ameloblastoma.

Peripheral ameloblastoma is a rare epithelial odontogenic tumor, limited to the soft tissues of the gingiva or oral mucosa. Peripheral ameloblastoma represents approximately 2% to 10% of all ameloblastomas. It is always considered to be benign, but occasionally it may be locally aggressive or with malignant potential. In this article, we report 3 new cases of benign peripheral ameloblastoma and further discuss the clinical management of this disease.

Double-barrel fibula vascularized free flap with dental rehabilitation for mandibular reconstruction.

PURPOSE: The vascularized free fibula flap has become the most popular reconstruction method after mandibular resection because of adequate bone graft length and acceptance of dental implants. However, using 1 fibula bone may produce a height discrepancy between the native mandible and the grafted fibula that results in subsequent difficulty in wearing conventional dentures or osteointegrated implants. Several options can be used to resolve this problem such as delayed onlay bone graft, iliac bone reconstruction, fibula distraction, and double-barrel fibula flap graft. This article describes the reconstruction of segmental mandible defects with the double-barrel fibula flap and denture rehabilitation. MATERIALS AND METHODS: This procedure was used in 7 patients. A donor site fibula corresponding to at least twice the length of the mandibular defect was harvested. Double-barrel free fibula grafting was performed in 6 patients for primary reconstruction and 1 patient for secondary reconstruction, including 3 cases of osteocutaneous flap with skin islands in the reconstruction of a composite defect from a malignant tumor. Prosthodontic treatment was completed in all 7 patients. Four patients received secondary implant-supported dental reconstruction, and 3 patients who received radiation (6,000 cGy) after graft surgery had conventional removable partial dentures. RESULTS: Microvascular fibula transfers were completely successful, and all skin paddles survived without necrosis. The original mandibular contour was maintained by a reconstruction plate; the reconstruction mandibular length was 6.5 to 10 cm, the reconstruction height of the double-barrel fibula was 3.0 to 3.8 cm, and all patients were satisfied with the postoperative facial esthetics and chewing function from the implant-supported denture and removable partial prostheses. CONCLUSIONS: Mandibular segmental defects can be esthetically and functionally reconstructed by a double-barrel vascularized fibula flap that not only matches the height of the native mandible but also allows osteointegrated dental implantation for dental rehabilitation.

Giant cell-rich osteosarcoma or giant cell reparative granuloma of the mandible?

Giant cell-rich osteosarcoma (GCRO) is a rare subtype of osteosarcoma, and no literature has reported occurrence in the mandible region up to now. In this article, we report a case of GCRO originating from the mandible in a 67-year-old woman who presented a history of painless mass located in the left side of the mandible after teeth extraction. The curettage biopsy histologic diagnosis is giant cell reparative granuloma before mandibulectomy surgery, but panoramic radiograph revealed an osteolytic lesion. The tumor was completely resected with segmental mandibulectomy and soft tissue with postoperative histologic diagnosis of GCRO. The free fibula osteomyocutaneous flap was performed to reconstruct the defect of the mandible and gingival mucosa. The patient received postoperative radiotherapy and chemotherapy. The 1-year follow-up situation is fine.

Schwannoma arising from intramasseteric region.

Schwannoma in the head and neck is usually arising in the parapharyngeal space, but intramasseteric schwannoma is very rare. We report a schwannoma arising from masseter muscle in a middle-aged woman, who presented with a history of a painless right cheek mass for 3 years. Computed tomography scan suggested that the mass was located within the masseter muscle. Fine-needle aspiration was performed and showed spindle neoplastic cells, which were suspected to be of mesenchymal tissue origin. The mass was completely resected under general anesthesia. It was a well-circumscribed and lobulated mass, 4 × 3 × 2 cm in size. Histological examination gave the diagnosis of schwannoma, which was also confirmed by immunohistochemical stainings for S-100 and vimentin. Neurologic sequelae and recurrence were not found at 2 years after surgery.