Sensory Nerves Affect Bone Regeneration in Rabbit Mandibular Distraction Osteogenesis.

Objectives: To investigate the effects of inferior alveolar nerve on new bone formation in rabbit mandibular distraction osteogenesis. Methods: 20 New Zealand White rabbits underwent bilateral distraction osteogenesis with a rate of 1 mm/day. The inferior alveolar nerve of one side was resected under the surgical microscope, with the inferior alveolar vascular intact. The contralateral side received sham operation. The rabbits were sacrificed at consolidation time of 28 days. The regenerate callus underwent radiograph examination, dual-energy X-ray absorptiometry, haematoxylin and eosin staining and histomorphometric analysis. A paired t-test was performed using SPSS 16.0 software package. Results: The BMD of the new bone in the distraction gap on the denervation side of mandibular was significantly lower (P<0.05) than on the control side. The histological investigation showed that the bone trabeculae were dis-arrayed containing dispersed cartilage cells on the denervation side, whereas the bone trabeculae were orderly with rich blood vessels and no cartilage cell on the control side. Both new bone volume and the thickness of new trabeculae were significantly lower on the denervation side than on the control side (P < 0.05). Conclusion: The loss of the sensory nerves could result in a decrease of the new bone quality during the mandibular distraction osteogenesis.

Norepinephrine inhibits mesenchymal stem cell chemotaxis migration by increasing stromal cell-derived factor-1 secretion by vascular endothelial cells via NE/abrd3/JNK pathway.

Mesenchymal stem cells (MSCs), which are physiologically maintained in vascular endothelial cell (VEC)-based niches, play a critical role in tissue regeneration. Our previous studies demonstrated that sympathetic denervation could promote MSC mobilization, thereby enhancing bone formation in distraction osteogenesis (DO), a self-tissue engineering for craniofacial and orthopeadic surgeries. However, the mechanisms on how sympathetic neurotransmitter norepinephrine (NE) regulates MSC migration are not well understood. Here we showed that deprivation of NE by transection of cervical sympathetic trunk (TCST) inhibited stromal cell-derived factor-1 (SDF-1) expression in the perivascular regions in rat mandibular DO. In vitro studies showed that NE treatment markedly upregulated p-JNK and therefore stimulated higher SDF-1 expression in VECs than control groups, and siRNA knockdown of the abrd3 gene abolished the NE-induced p-JNK activation. On the other hand, osteoblasts differentiated from MSCs showed an increase in SDF-1 secretion with lack of NE. Importantly, NE-treated VECs inhibited the MSC chemotaxis migration along the SDF-1 concentration gradient as demonstrated in a novel 3-chamber Transwell assay. Collectively, our study suggested that NE may increase the SDF-1 secretion by VECs via NE/abrd3/JNK pathway, thereby inhibiting the MSC chemotaxis migration from perivascular regions toward bone trabecular frontlines along the SDF-1 concentration gradient in bone regeneration.

Slug silencing inhibited perineural invasion through regulation of EMMPRIN expression in human salivary adenoid cystic carcinoma.

Salivary adenoid cystic carcinoma (SACC) is the most frequent salivary gland malignancy with a unique characteristic that has been named perineural invasion (PNI). EMMPRIN is a transmembrane glycoprotein that has been demonstrated to promote PNI in SACC. Slug, one of the most effective promoters of the epithelial-to-mesenchymal transition (EMT), has been found to be associated with PNI in SACC. The aim of the present study was to investigate the roles and relationships of Slug, EMMPRIN, and E-cadherin in the PNI process of SACC. The expression levels of Slug, EMMPRIN, and E-cadherin in 115 primary SACC cases were statistically analyzed by immunohistochemistry. Simultaneously, the SACC cell line SACC-83 was transfected with recombinant plasmids of silencing Slug (si-Slug) and/or silencing EMMPRIN (si-EMMPRIN). The functions of Slug and EMMPRIN in the EMT and PNI process were assessed by reverse transcription PCR (RT-PCR), western blotting, morphological observation, scratch test, migration assay, and in vitro perineural invasion assay. The immunohistochemical statistics revealed that the high expression of Slug and EMMPRIN and the low expression of E-cadherin were significantly associated with the PNI of SACC (P < 0.05). Slug expression was significantly associated with EMMPRIN expression (P < 0.05), and Slug expression and EMMPRIN expression were both significantly negatively associated with E-cadherin expression (P < 0.05). Slug and EMMPRIN silencing both significantly inhibited EMMPRIN expression but promoted E-cadherin expression in SACC-83 cells (P < 0.01). The series of in vitro assays revealed that silencing of Slug, EMMPRIN, or both induced cell morphology changes and inhibited tumor cell motility and PNI ability in SACC-83 cells (P < 0.01). These results suggested that Slug silencing could inhibit the EMT process by downregulating EMMPRIN and then upregulating E-cadherin in the PNI process of SACC. The present study indicated that Slug and EMMPRIN are potential biomarkers and therapeutic targets for the diagnosis and treatment of PNI in human SACC.

Targeting P38 Pathway Regulates Bony Formation via MSC Recruitment during Mandibular Distraction Osteogenesis in Rats.

Distraction osteogenesis (DO) is a widely used self-tissue engineering. However, complications and discomfort due to the long treatment period are still the bottleneck of DO. Novel strategies to accelerate bone formation in DO are still needed. P38 is capable of regulating the osteogenic differentiation of both mesenchymal stem cells (MSCs) and osteoblasts, which are crucial to bone regeneration. However, it is not clear whether targeting p38 could regulate bony formation in DO. The purpose of the current work was to investigate the effects of local application of either p38 agonist anisomycin or p38 inhibitor SB203580 in a rat model of DO. 30 adult rats were randomly divided into 3 groups: (A) rats injected with DMSO served as the control group; (B) rats injected with p38 agonist anisomycin; (C) rats injected with p38 inhibitor SB203580. All the rats were subjected to mandibular distraction and the injection was performed daily during this period. The distracted mandibles were harvested on days 15 and 30 after surgery and subjected to the following analysis. Micro-computed tomography and histological evaluation results showed that local application of p38 agonist anisomycin increased new bone formation in DO, whereas p38 inhibitor SB203580 decreased it. Immunohistochemical analysis suggested that anisomycin promoted MSC recruitment in the distraction gap. In conclusion, this study demonstrated that local application of p38 agonist anisomycin can increase new bone formation during DO. This study may lead to a novel cell-based strategy for the improvement of bone regeneration.

Elective neck dissection in patients with head and neck adenoid cystic carcinoma: an international collaborative study.

BACKGROUND: Adenoid cystic carcinoma (ACC) accounts for 3-5 % of all head and neck malignancies. Investigations of outcomes from elective neck dissection (END) for patients with ACC are sparse. This study aimed to assess the impact of END on the survival of patients with ACC. METHODS: This retrospective multicentered study investigated 270 patients who underwent neck dissection. A multivariate analysis assessed associations of clinical and histopathologic characteristics with survival outcomes. RESULTS: The primary tumor sites included the oral cavity in 250 patients (55 %), the major salivary glands in 133 patients (29 %), the sinonasal mucosa in 68 patients (15 %), and the larynx in six patients (1 %). The overall rate of occult nodal metastases among the patients who underwent END was 17 % (38/226). The highest incidence of occult nodal metastases was with the oral cavity (66 %). The 5-year overall survival (72 and 79 % for patients with or without END, respectively) and disease-specific survival (74 and 81 % for patients with or without END, respectively) were similar in the two groups. The subgroup analysis of patients according to the primary site showed no significant impact of END on outcome. In the multivariate analysis, primary site, T classification, and N classification were the only variables associated with outcome. CONCLUSIONS: The incidence of occult neck metastases among patients with ACC is 17 %. The highest incidence of occult metastases is with the oral cavity. Statistical analysis showed no survival advantage for patients who underwent END compared with those who did not.

Age-based treatment of aggressive fibromatosis in the head and neck region.

PURPOSE: To review our experience regarding the difference in management and treatment outcomes of aggressive fibromatosis of the head and neck region in children and adults, emphasizing, in particular, the role of conservative surgery in comprehensive treatment strategies. PATIENTS AND METHODS: A retrospective analysis of patients with aggressive fibromatosis was performed during a 5-year period (2008 to 2012). Nine patients were enrolled in the present study, including 5 children (age, <18 years) and 4 adults (age, >18 years). All patients underwent surgical intervention and were treated by surgical resection with different surgical margins. Adjuvant low-dose chemotherapy and radiotherapy were given to pediatric and adult patients, respectively, with macroscopically or microscopically positive surgical margins. RESULTS: All 5 pediatric patients (3 females and 2 males) received low-dose chemotherapy after conservative surgical resection (in 4 patients, microscopically incomplete resection; and in 1 patient, macroscopic residual tumor). Of the 4 adults (3 females and 1 male), 2 underwent complete surgical resection and 2 underwent surgery and postoperative radiotherapy (1 patient had microscopically suspected residual tumor and 1 had macroscopic residual tumor). The patients were followed up for a period of 7 to 51 months. Two pediatric patients and one adult patient had disease progression after resection and became stable after continued adjuvant therapy. None of the patients had functional or cosmetic defects. All patients had good long-term outcomes, with no disease progression. CONCLUSIONS: For the treatment of aggressive fibromatosis, conservative resection with preservation of form and function should be given greater priority in all age groups. Also, postoperative adjuvant therapy is vital for patients with gross or microscopic residual tumor to obtain progression-free survival.

A comparison of stromal cell-derived factor-1 expression during distraction osteogenesis and bone fracture in the mandible.

Distraction osteogenesis (DO) has been a widely applied technique in orthopedics and craniofacial surgery. However, the exact molecular mechanism by which the mechanical stimulus is translated into biological signals is still poorly understood. In this study, we examined and compared the expression of stromal cell-derived factor-1 (SDF-1) during mandibular distraction osteogenesis and fracture in rats, respectively. Forty-eight male Sprague-Dawley rats were divided into 2 groups and received unilateral distraction osteogenesis and rigid internal fixation, respectively, after the osteotomy on the right mandible. The harvested mandibles were examined radiographically, histologically, and immunohistochemically. We found that the expression of SDF-1 was mainly detected in the osteoblasts and blood vessels, and there were more intensive expression of SDF-1 in DO zones than in bone fracture zones. The quantitative analysis by enzyme-linked immunosorbent assay showed that SDF-1 reached a greater peak and maintained a longer period of up-regulation in DO than in fracture healing (P < 0.05). These results suggest that the distraction procedure markedly promotes the high expression of SDF-1 which facilitates the induction of bone formation during DO.

Treatment of malignant triton tumor in zygomatic region.

Malignant triton tumor (MTT) is extremely rare and supposed to be highly aggressive because of high propensity for local recurrence and metastasis. To date, only about 170 cases were reported in various body locations including trunks, maxillary sinus, neck, extremities, retroperitoneal, and so on. We present a case of MTT in the zygoma with good outcome. A 27-year-old male patient with progressive swelling and pain in the right zygoma was proved to have an MTT by biopsy. Radical resection accompanying postoperative radiotherapy was adopted, and then the soft and hard tissue defects were repaired by prosthesis. The patient recovered well and was satisfied with the facial contour. At 45-month follow-up, there was no recurrence or metastasis that occurred. According to literature review, one third of MTTs appeared in the head and neck regions and seem to have a better prognosis. Radical resection is the most important remedy, and adjuvant radiotherapy could be helpful. With early finding and effective treatments, satisfactory outcome could be achieved.

Effects of sympathetic innervation loss on mandibular distraction osteogenesis.

Sympathetic nerve system has been proved to have important regulative effects to bone mass. However, the role of sympathetic nerve system in distraction osteogenesis (DO) is unclear. Here we show that the sympathetic nerve system plays an important role in mandibular DO. Thirty male Sprague-Dawley rats were divided into 2 groups at random. Right-side mandibular DO was performed on the 15 rats in control group (group A). Bilateral transection of cervical sympathetic trunk and right-side mandibular DO were performed on the 15 rats in the experimental group (group B). After operation, quantitative general observations, micro-computed tomography bone morphology analysis, and hematoxylin-eosin staining osseous tissue on new osteotylus in distraction gap were performed at consolidation time of 1, 14, and 28 days. SPSS 12.0 software package was used for statistical analysis. At 1 and 14 days of consolidation time, there was more continuous bone formation in the experimental group than that of the control group as determined by gross observation. Bone formation parameters including bone mineral density, bone volume-total volume ratio, bone trabeculae number as determined by micro-CT, and histological study of the test group were significantly higher than those of the control group (P < 0.05). No significant difference was noted between the 2 groups on consolidation time of 28 days. Our study suggested that the sympathetic innervation loss could improve mandibular DO and new bone formation, and the sympathetic nerve system might negatively regulate the process of DO.

Primary First Bite Syndrome of the Parotid Gland: Case Report and Literature Review.

OBJECTIVE: A case of primary first bite syndrome (FBS), diagnosed in a patient with nonspecific adenocarcinoma of the deep lobe of the parotid gland. DATA SOURCES: A Medline literature search was conducted on PubMed, using the keywords "first bite syndrome." REVIEW METHODS: Using primary FBS and existence of a definite etiology as inclusion criteria. RESULTS: We report on an unusual case of primary FBS, which had no surgical history. After multiple examinations, the pain was localized to a mass in the deep lobe of the parotid gland. After tumorectomy, the FBS pain was significantly relieved. The postoperative pathological examination determined that the excised mass was a nonspecific adenocarcinoma. Reviewing the literature, we found that primary FBS was mostly caused by malignant tumors in the inferior temporal fossa, the deep lobe of the parotid gland, and (or) the parapharyngeal space. Surgery was reported to be an effective treatment. CONCLUSION: The case highlights the critical importance of identifying the etiology of primary FBS. When manifested with a primary FBS, malignant tumors must be high on the differential diagnosis list, especially those in the region of the inferior temporal fossa, the deep lobe of the parotid gland, and the parapharyngeal space.

An animal experiment study on the application of indocyanine green angiography in the harvest of multi-angiosome perforator flap.

Background: This study sought to explore the application value of indocyanine green angiography (ICGA) in the harvest of multi-angiosome perforator flap and the effect of low molecular weight heparin (LMWH) on the survival of postoperative flap. Methods: Twenty-four SD male rats were selected to construct a three-angiosome perforator flap model with the unilateral iliolumbar artery perforator. They were randomly divided into two groups: the control group was injected with indocyanine green (ICG) into the femoral vein during the operation, and the fluorescence signal was collected and quantitatively analyzed using Real-Time Image Guided System to determine the intraoperative fluorescence imaging length. The experimental group was injected subcutaneously with LMWH (400 U/kg) after 0.5 h postoperatively, and the control group was injected with the same amount of normal saline. The injection was repeated at the same time each day from 0 to 7 days postoperatively. After the flap was sutured in situ, ICGA was performed at 0, 1, 3, 5, and 7 days postoperatively to observe the vascular structure of the two groups of flaps. The flap survival length of the control group was counted at 7 days postoperatively, and the correlation between the intraoperative fluorescence imaging length and the survival length at 7 days postoperatively was calculated. The proportion of distal necrosis of the flaps between the two groups was compared at 7 days postoperatively. Results: The average length of intraoperative fluorescence imaging in the control group was 6.29±0.50 cm, and the survival length of the flap at 7 days postoperatively was 8.24±0.52 cm. The actual survival length was higher than the intraoperative fluorescence imaging length, with a ratio of 1.31±0.08. The difference was statistically significant (P<0.05). At 7 days postoperatively, the flap necrosis ratio of experimental group and control group were 10.92%±1.30% and 19.11%±1.19%, and the flap necrosis ratio of experimental group was lower than that of control group (P<0.001). Conclusions: ICGA can locate the position of perforator, and can be used to predict and observe the length of distal survival of multi-angiosome perforator flap postoperatively. LMWH can promote the distal survival of flap and reduce flap necrosis.

Bleomycin A5 sclerotherapy for cervicofacial lymphatic malformations.

OBJECTIVES: The purpose of this study was to document the results of bleomycin A5 sclerotherapy for cervicofacial lymphatic malformations (LMs), and the clinical data of 65 patients between October 2004 and October 2007 were reviewed. METHODS: Of the 65 patients in the study, 60 patients were given intralesional injection of bleomycin A5. Five patients underwent partial resection, and then an injection of bleomycin A5 for the remaining lesion. The outcomes were assessed by physical examination and Doppler ultrasonography scan. The follow-up time was from 6 months to 3 years after the last injection (mean, 16 months). RESULTS: Among the 65 patients, 41 were men and 24 were women (1.7:1 male:female ratio), the age range was 3 months to 45 years (mean, 12 years). Thirty-two lesions (49%) were macrocystic, 30 (46%) were microcystic, and 3 (5%) were combined. Each patient received 1 to 10 injections (mean, 3.0 injections) for the whole course of treatment, and the total dose of bleomycin A5 was from 8 to 80 milligrams (mean, 24.0 mg). Twenty-six of 32 macrocystic lesions (81%) showed greater than 90% reduction, whereas another 6 (19%) exhibited 50% to 90% reduction. Nineteen of 30 microcystic lesions (63%) showed greater than 90% reduction; 10 (33%) had 50% to 90% reduction; and 1 (4%) had less than 50% size reduction. Of the 3 combined lesions, 2 (67%) had greater than 90% shrinkage, and 1 (3%) had less than 50% reduction. The complications included ulceration of oral mucosa, minor soft tissue atrophy, mild fever, and hematoma. There was no recurrence throughout the follow-up period. CONCLUSION: These data suggest bleomycin A5 is a safe and effective intralesional agent for the treatment of macrocystic LMs, superficial oral mucosa LM, and localized deep microcystic lesions. For extensive macrocystic LMs involving contiguous anatomic areas and diffuse microcystic lesions involving deep tissues, bleomycin A5 injection combined with resection is necessary.

Surgical resection of a huge cemento-ossifying fibroma in skull base by intraoral approach.

Cemento-ossifying fibroma, also known as ossifying fibroma, usually occurs in the mandible and less commonly in the maxilla. The huge example in the skull base is even rare. We present a case of a huge cemento-ossifying fibroma arising below the skull base of a 30-year-old woman patient. Radiologic investigations showed a giant, lobulated, heterogeneous calcified hard tissue mass, which is well circumscribed and is a mixture of radiolucent and radiopaque, situated at the rear of the right maxilla to the middle skull base. The tumor expands into the right maxillary sinus and the orbital cavity, fusing with the right maxilla at the maxillary tuberosity and blocking the bilateral choanas, which caused marked proptosis and blurred vision. The tumor was resected successfully by intraoral approach, and pathologic examination confirmed the lesion to be a cemento-ossifying fibroma. This case demonstrates that cemento-ossifying fibroma in the maxilla, not like in the mandible, may appear more aggressive because the extensive growth is unimpeded by anatomic obstacles and that the intraoral approach can be used to excise the tumor in the skull base.

Surgical treatment of a giant neurofibroma.

Neurofibromatosis type 1, an autosomal dominant inherited disease, presents pathologic symptoms of multiple systems, including neurofibromatosis, skeletal dysplasia, café-au-lait spots in skins, and so on. A 45-year-old man with neurofibromatosis type 1 was reported in this article. The patient presented a giant neurofibroma in his head and neck, dysplasia of skull, facial bones and spinal columns, and multiple café-au-lait spots in systematic skins. Satisfactory curative effects were obtained in this case after tumor resection and prosthesis implantation.

A clinical study of ultrasound-guided intralesional injection of bleomycin A5 on venous malformation in cervical-facial region in China.

OBJECTIVES: To evaluate the therapeutic outcome of ultrasound-guided intralesional injection of bleomycin A5 on treatment of venous malformation (VM) in cervical-facial region. METHODS: Seventy-five patients (32 male, 43 female), ranging in age from 13 to 60 years old, suffering from VM in cervical-facial region were admitted to and treated at our hospital between June 2006 and February 2007. Of all the patients, 54 malformations were located in the facial region, eight in the submental region, 10 in the submandible region, and three in the cervical region; all were treated by ultrasound-guided intralesional injections of bleomycin A5. The size of the lesions ranged from 6 x 9 mm to 32 x 39 mm. Injection of bleomycin A5 on venous malformation was then carried out through the inspection of ultrasonography. Repeated course of bleomycin A5 injection was administrated for larger malformations. The amount was 8 mg each time. The therapeutic interval was two to four weeks. The therapeutic outcome on venous malformation was evaluated by physical examination and ultrasonography with Doppler according to the Shou standards, including four grades; cured, basically cured, improved, and invalid. The complications were also observed during and after injection. RESULTS: The duration of follow-up ranged from 6 to 24 months. The average times of treatment were 1.64 times. Among them, 42 patients (56%) received only one time of treatment, 21 (28%) patients received two times, nine (12%) patients received three times, and three (4%) patients received four times. According to criteria of therapeutic outcome, the results showed cured in 63 patients (84%), basically cured in 10 patients (13.33%), improved in two patients (2.67%), and none ineffective. Seventy-one patients (94.67%) had local swelling in injection region for several days and two patients (2.67%) developed temporary dizziness after treatment. There were no other complications recorded. CONCLUSIONS: Intralesional injection of bleomycin A5 establishes a promisingly effect way for patients suffering from VM in the cervical-facial region under ultrasound guidance.

The association between roofing material and head injuries during the 2008 Wenchuan earthquake in China.

STUDY OBJECTIVE: We analyze the spectrum of earthquake-related head injuries resulting in hospitalization and arising from the 2008 Wenchuan Earthquake in China. An additional objective is to assess injury patterns associated with 2 types of roofing structures found in this region of China. METHODS: This descriptive study included data on trauma patients at 8 hospitals in Jiangyou for the 14 days immediately after the earthquake. The patients were either from Jiangyou County, which experienced a modified Mercalli intensity level of VIII, or from Beichuan County (Mercalli intensity level of X). Of the 5,775 earthquake-related injuries, 1,484 (25.7%) involved the head and were classified into 4 categories. Seven injury mechanisms were also analyzed to determine the association with the 4 types of head injuries. RESULTS: Scalp injuries (43%) were the most common type of head injuries, followed by facial injuries, 482 (32%), intracranial injuries, 218 (15%), and skull fractures, 117 (8%). Differences in injury type and cause were apparent, with scalp injuries being more common (49%) in Jiangyou than in Beichuan (30%) and falling clay tiles contributing more (40%) to this injury in the former city than the latter (6%). In contrast, precast concrete plank roofing caused 20% of scalp injuries in Beichuan compared with 3% in Jiangyou. CONCLUSION: Scalp injuries were the most common head injury type. Falling clay roofing tiles and precast concrete plank roofs are important injury mechanisms, and their contribution may reflect differences in building construction.

Effects of nerve growth factor delivery via a gel to inferior alveolar nerve in mandibular distraction osteogenesis.

Inferior alveolar nerve (IAN) injury is a concern in mandible distraction osteogenesis (DO). We have previously demonstrated that repeated local injections of human nerve growth factor beta (NGF-beta) have significantly enhanced the histologic recovery of the IAN in a rabbit model of DO. This study was to further test the effect of a single injection of human NGF-beta delivered via a collagen/nanohydroxyapatite/kappa-carrageenan gel to the recovery of the IAN in DO. Rabbits underwent mandibular DO at a rate of 0.75 mm/12 h for 6 days. At the end of the distraction period, injections were performed near the IAN percutaneously as follows: group 1, human NGF-beta in the gel; group 2, human NGF-beta in saline; group 3, the gel alone; and group 4, saline alone. At 14 days after the end of distraction, IAN histologic findings and histomorphometric parameters were evaluated. Histologically, there were less myelin debris and more abundant regenerating nerve fibers in group 1 than the other groups. Both the myelinated fiber density and the myelinated axon area in group 1 were significantly higher than groups 3 and 4 (P < 0.01); the myelinated axon area in the group 1 was significantly higher than group 2 (P < 0.01). In conclusion, the delivery of human NGF-beta in the gel leads to a better acceleration of the IAN injury recovery over the saline delivery. It provides a possible way to enhance the recovery of nerve injuries in craniofacial DO clinically.

Tisssue responses in corticotomy- and osteotomy-assisted tooth movements in rats: histology and immunostaining.

INTRODUCTION: The purpose of this histologic study was to examine underlying cellular responses to corticotomy- and osteotomy-assisted tooth movements. METHODS: Thirty-six rats were divided into 5 groups: corticotomy-assisted tooth movement (CO + TM), sham corticotomy without tooth movement (CO alone), osteotomy-assisted tooth movement (OS + TM), sham osteotomy without tooth movement (OS alone), and unassisted tooth movement (TM alone). Standard orthodontic springs were activated to produce mesial tooth movement. The rats were killed at 3, 21, and 60 days after activation for osteoclast and blood vessel counts, and immunostaining with proliferating cell nuclear antigen (PCNA), transforming growth factor beta 1 (TGF beta 1), vascular endothelial growth factor (VEGF), and osteocalcin were performed. RESULTS: The CO + TM group had significantly more osteoclasts at 3 days (P <0.005) compared with the OS + TM group. The alveolar bone surrounding the dental roots was replaced with multicellular tissue at 21 days in the CO + TM group but was intact in the OS + TM group with the exception of a distal distraction site. At day 21, immunostaining with PCNA, TGF beta 1, VEGF, and osteocalcin occurred at the mesial border of bone in the CO + TM group, whereas a diffuse pattern was observed in the distal distraction sites at 21 and 60 days in the OS + TM group. CONCLUSIONS: Corticotomy-assisted tooth movement produced transient bone resorption around the dental roots under tension; this was replaced by fibrous tissue after 21 days and by bone after 60 days. Osteotomy-assisted tooth movement resembled distraction osteogenesis and did not pass through a stage of regional bone resorption.

CCL2/CCR2 Axis Promotes the Progression of Salivary Adenoid Cystic Carcinoma via Recruiting and Reprogramming the Tumor-Associated Macrophages.

Objective: The present study investigated the roles and underlying mechanism of CCL2/CCR2 axis in the interactions between tumor cells and tumor-associated macrophages (TAMs) during the progression of salivary adenoid cystic carcinoma (SACC). Methods: Immunohistochemical staining and survival analysis were performed to study the correlation and clinical value of CD68, CD163, CCL2, and CCR2 expression in SACC cases. CCL2 silencing by RNA interference and CCR2 blocking by CCR2 specific antagonist (RS504393) were performed. ELISA, qRT-PCR, western blot, immunofluorescence, flow cytometry, CCK8, scratch wound healing, and transwell assays were used to explore the functional roles and possible mechanism of CCL2/CCR2 axis in the interactions between SACC cells and TAMs. The effects of targeting TAMs by blocking the CCL2/CCR2 axis were investigated in a xenograft mice model with SACC cells. Results: The high infiltration of TAMs marked by CD68 and high infiltration of M2 TAMs marked by CD163 were significantly correlated with the expression of CCL2 and CCR2 in SACC tissues. Notably, the high infiltration of TAMs and the overexpression of CCL2 were obviously associated with the clinical progression and poor prognosis of SACC. SACC cells derived CCL2 could activate its receptor CCR2 expression in TAMs in vitro. The in vitro results further indicated that the SACC cells derived CCL2 was involved in the recruitment, M2 polarization, and GDNF expression of TAMs through the CCL2/CCR2 axis. Meanwhile, TAMs derived GDNF promoted the proliferation, migration, and invasion of SACC cells through the GDNF/p-RET pathway. Treating immunodeficient mice with the CCR2 antagonist (RS504393) greatly inhibited the infiltration of TAMs and the tumorigenicity of SACC cells. Conclusion: These new findings indicated that the CCL2/CCR2 axis promoted the progression of SACC cells via recruiting and reprogramming TAMs. Targeting TAMs by blocking the CCL2/CCR2 axis might be a prospective strategy for SACC therapy.

NT-3/TrkC Axis Contributes to the Perineural Invasion and the Poor Prognosis in Human Salivary Adenoid Cystic Carcinoma.

The present study was aimed to investigate the role and mechanism of neurotrophin-3 (NT-3) and its specific receptor tropomyosin receptor kinase C (TrkC) in the perineural invasion (PNI) process of the salivary adenoid cystic carcinoma (SACC). The co-cultured system between SACC cells and Schwann cells (SCs) was employed to detect the expression of NT-3 and TrkC. The results of ELISA, qRT-PCR and western blot showed that NT-3 was noticeably elevated in the co-cultured SACC-83 cells, while TrkC was increased in the co-cultured SCs. The results of scratch wound healing, migration, and 3D co-culture assays showed that the directional migration abilities of the co-cultured SACC-83 cells and SCs were significantly increased. Under the stimulation of NT-3, the directional motor ability of SACC-83 cells and SCs was significantly improved, and the apoptosis of SACC-83 cells and SCs were obviously inhibited. In addition, blocking TrkC by its specific inhibitor AZD7451 could significantly inhibit these effects. Immunohistochemistry staining showed that the positive expression of NT-3 (88.5%) and TrkC (92.3%) was significantly correlated with the PNI in SACC specimens (P < 0.05). Additionally, the high expression of NT-3 was significantly associated with the poor prognosis of SACC patients (P < 0.05). The present study indicated that NT-3/TrkC axis contributed to the PNI progression and the poor prognosis of SACC via regulating the interaction between SACC cells and SCs. Interruption of the interaction between SACC cells and SCs by blocking the NT-3/TrkC axis might be an effective strategy for anti-PNI therapy in SACC.