PDGF-AA guides cell crosstalk between human dental pulp stem cells in vitro via the PDGFR-α/PI3K/Akt axis.

AIM: To explore the influence of PDGF-AA on cell communication between human dental pulp stem cells (DPSCs) by characterizing gap junction intercellular communication (GJIC) and its potential biomechanical mechanism. METHODOLOGY: Quantitative real-time PCR was used to measure connexin family member expression in DPSCs. Cell migration and CCK-8 assays were utilized to examine the influence of PDGF-AA on DPSC migration and proliferation. A scrape loading/dye transfer assay was applied to evaluate GJIC triggered by PDGF-AA, a PI3K/Akt signalling pathway blocker (LY294002) and a PDGFR-α blocker (AG1296). Western blotting and immunofluorescence were used to test the expression and distribution of the Cx43 and p-Akt proteins in DPSCs. Scanning electron microscopy (SEM) and immunofluorescence were used to observe the morphology of GJIC in DPSCs. RESULTS: PDGF-AA promoted gap junction formation and intercellular communication between human dental pulp stem cells. PDGF-AA upregulates the expression of Cx43 to enhance gap junction formation and intercellular communication. PDGF-AA binds to PDGFR-α and activates PI3K/Akt signalling to regulate cell communication. CONCLUSIONS: This research demonstrated that PDGF-AA can enhance Cx43-mediated GJIC in DPSCs via the PDGFR-α/PI3K/Akt axis, which provides new cues for dental pulp regeneration from the perspective of intercellular communication.

TGF-ß2 increases cell-cell communication in chondrocytes via p-Smad3 signalling.

Connexin 43 (Cx43)-mediated gap junction intercellular communication (GJIC) plays a crucial role in the pathology and physiology of joint tissues. Transforming growth factor-ß2 (TGF-ß2), one of the potent regulatory factors in chondrocytes, plays a key role in the regulation of cell cycle and development of joint diseases. However, it is still unknown how TGF-ß2 mediates GJIC in chondrocytes. The aim of this study was to explore the potential mechanism by which TGF-ß2 regulates GJIC in chondrocytes. CCK-8 assays and scratch assays were performed to define the role of TGF-ß2 on cell proliferation and migration. The scrape loading/dye transfer assay and scanning electron microscopy (SEM) were used to verify the effect of TGF-ß2 on GJIC between chondrocytes. qPCR was performed to analyse the expression of genes in the gap junction protein family in chondrocytes. The expression of the Cx43 protein and phosphorylated Smad3 (p-Smad3) was evaluated by western blot assay. Immunofluorescence staining was used to explore p-Smad3 signalling pathway activation and Cx43 distribution. From these experiments, we found that the Cx43 protein was the most highly expressed member of the gap junction protein family in chondrocytes. We also found that TGF-ß2 facilitated cell-to-cell communication in chondrocytes by upregulating Cx43 expression in chondrocytes. Finally, we found that TGF-ß2 activated Smad3 signalling and promoted the nuclear aggregation of p-Smad3. Inhibition experiments by SIS3 also confirmed that TGF-ß2-mediated GJIC through p-Smad3 signalling. For the first time, this study confirmed that TGF-ß2 could regulate the formation of Cx43-mediated GJIC in chondrocytes via the canonical p-Smad3 signalling pathway.

Study on clinical and biological characteristics of ameloblastic carcinoma.

BACKGROUND: Ameloblastic carcinoma (AC) is an odontogenic malignant tumor which is closely related to benign ameloblastoma. Because of its rarity, diagnosis and treatment are difficult. In this study, we summarized and analyzed the clinical and biological characteristics of AC. RESULTS: Fifteen patients with AC and a median age of 53 years were identified. Among of them, five patients who were tested carried a BRAF-V600E mutation. Two patients presented with cervical lymph nodes and lung metastases. Primary AC was more invasive, and the bone destruction ability of the primary type was more radical than that of the secondary type. CONCLUSIONS: This study revealed that the BRAF-V600E mutation was related to the aggressive behavior of AC, and early radical resection is crucial. Moreover, targeted therapy may be a new direction in the future.

[Clinical value of oral repair membrane and ß-tricalcium phosphate in the treatment of the postoperative bone defect of jaw cyst].

OBJECTIVE: This study aims to evaluate the clinical effect of oral repair membrane and ß-tricalcium phosphate (ß-TCP) on the treatment of jaw cyst. METHODS: A retrospective analysis was performed on 81 cases of jaw cysts, and clinical data were collected for the comparison of traditional surgical curettage (group A, 27 cases), biofilm covering bone wounds after curettage (group B, 27 cases), and ß-TCP filling combined with biofilm covering. RESULTS: No recurrence occurred in 81 patients, and no significant difference in preoperative CT value among the three groups (P<0.05). Follow-up CT reexamination 3, 6, and 12 months after operation showed significant differences among the three groups of CT values (P<0.05). Group C was better than Group B or Group A (P<0.05). CONCLUSIONS: In traditional jaw cyst curettage, the application of biofilm exhibited good osteogenesis effect, and the combined application of ß-TCP and biofilm exerted a better effect.

Downregulation of MicroRNA-551b Correlates With Dissemination of Human Oral Squamous Cell Carcinoma.

PURPOSE: Altered expression of microRNAs contributes to invasion and metastasis of many human cancers; however, the importance of microRNAs in head and neck cancers remains to be elucidated. In this study, we examined whether altered microRNA (miR)-551b expression correlated with invasive phenotypes of human oral squamous cell carcinoma (OSCC) in vivo and in vitro. MATERIALS AND METHODS: Real-time polymerase chain reaction was used to detect the expression level of miR-551b in 71 OSCC tissues with lymph node metastasis and 50 nonmetastatic OSCC tissues. We also constructed miR-551b mimic-transfected cell lines HN4 and HN12. The effects of overexpressing miR-551b on the proliferation, migration, and invasion of OSCC cells were examined using Cell Counting Kit 8 (Dojindo, Kumamoto, Japan), plate clone formation, wound healing, and Transwell invasion experiments (Corning, Corning, NY). The association between clinical pathologic parameters and the expression level of miR-551b was analyzed using Kaplan-Meier survival analysis. RESULTS: The expression of miR-551b measured 0.33 ± 0.11 in the 71 OSCC tissues with lymph node metastasis versus 0.54 ± 0.06 in the 50 tissues with non-lymph node metastasis (P = .021). Regarding OSCC patients, the expression of miR-551b negatively correlated with patients' overall survival (P = .035). The ectopic expression of miR-551b inhibited the invasion and migration of OSCC cells. CONCLUSIONS: This is the first report showing that reduced miR-551b expression may be an event leading to OSCC invasion and metastasis.

Piwi-Interacting RNA1037 Enhances Chemoresistance and Motility in Human Oral Squamous Cell Carcinoma Cells.

BACKGROUND: Piwi-interacting RNAs (piRNAs) are thought to silence transposable genetic elements. However, the functional roles of piRNAs in oral squamous cell carcinoma (OSCC) remain unelucidated. In the present study, we aimed to investigate the role of Piwi-interacting RNA 1037 (piR-1037) in chemoresistance to cisplatin (CDDP)-based chemotherapy and the oncogenic role of piR-1037 in OSCC cells. METHODS: RT-PCR was used to evaluate the levels of piR-1037 and X-linked Inhibitor of apoptosis protein (XIAP) mRNA in OSCC cell lines or tumor xenografts. Transfection of piR-1037 DNA antisense and piR-1037 RNA oligonucleotides was performed to suppress and overexpress piR-1037 in OSCC cells, respectively. A CCK8 assay was used to measure the viability or proliferation of OSCC cells. Apoptosis in OSCC cells and xenografts was determined using a TUNEL assay kit. The activity of caspase-3, caspase-8 and caspase-1 in OSCC cells was measured with colorimetric caspase assay kits. Western blot analysis was conducted to analyze XIAP expression in OSCC cells and xenograft samples. Immunoprecipitation (IP) and RNA pull-down assays were utilized to analyze the piR-1037 - XIAP interaction. Transwell assays were performed to evaluate migration and invasion of OSCC cells. RESULTS: CDDP treatment upregulated piR-1037 expression in OSCC cells and OSCC xenografts. Suppression of the CDDP-induced upregulation of piR-1037 expression enhanced the sensitivity of OSCC cells to CDDP. piR-1037 promoted protein expression and directly bound XIAP, a key apoptotic inhibitor that is implicated in chemoresistance. The relationship between piR-1037 and XIAP suggested that piR-1037 enhanced OSCC cell chemoresistance to CDDP at least partially through XIAP. Moreover, targeting the basal expression of piR-1037 inhibited cell motility by affecting epithelial-mesenchymal transition (EMT). CONCLUSION: piR-1037 enhances the chemoresistance and motility of OSCC cells. piR-1037 promotes chemoresistance by interacting with XIAP and regulates the motility of OSCC cells by driving EMT.

Diagnosis and treatment of a carotid body tumor: A case report of a rare bilateral tumor.

In the present case report, a rare bilateral carotid body tumor (CBT) and the imaging and pathological features of a CBT are described. In the present report, a rare case of bilateral carotid body tumor, which developed in the bifurcation of the common carotid artery, and the clinical manifestations, imaging and pathological features of this CBT are summarized. The imaging cannot validate the diagnosis; however, imaging identified that the tumor exhibited an intact envelope. Immunohistochemical staining revealed that the tumor cells were strongly positive for cluster of differentiation 56, Syn and protein S-100, moderately positive for transcription factor E3, negative for cytokeratin and epithelial membrane antigen, and partial cells were weakly positive for Desmir (<5%). In view of the clinical and pathological features of the carotid body tumor, surgery is hypothesized to be the optimal treatment and may enable the tumor to be resected completely. Refined surgical techniques provide the security of safe resection and decrease the risk of complications occurring.