[Multidisciplinary team model for patients with oral cancer and systemic diseases: an expert consensus]

Large general hospitals currently play an increasingly important role in the diagnosis and treatment for acute critical patients and difficult diseases because of the development of dual referral system and hierarchical diagnosis, as well as the formation of medical treatment alliance. Patients with oral cancers are often associated with systemic diseases, which increases the complexity of the condition. Thus, meeting the demand through the traditional single medical model is difficult. As such, a multidisciplinary team (MDT) model has been proposed and has achieved a good clinical effect. To standardize the application of this model, we organized an event in which relevant experts discussed and formulated a consensus to provide standardized suggestions on the MDT process and the diagnosis and treatment of common systemic diseases as reference for clinical practice.

[Relationship among areca nut, intracellular reactive oxygen species, and autophagy]

The relationship between areca nut as a primary carcinogen and oral cancer has been widely concerned. Areca can change the levels of reactive oxygen species (ROS) and autophagy in cells, and the levels of ROS and autophagy are closely related to the occurrence and development of tumors. This paper reviewed the relationships among areca nut, intracellular ROS, and autophagy.

Application of Delayed Surgical Managements in Patients with Stensen's Duct Injury

The study aimed to retrospectively evaluate surgical treatment outcomes after delayed parotid gland and duct injuries. Nine patients subjected to parotid gland and duct injuries with 1- to 3-month treatment delay were retrospectively evaluated with special reference of etiology, past medical history, and injury location. Conservative treatment, microsurgical anastomosis, and diversion of salivary flow or ligation were chosen for delayed parotid gland and duct injuries concerning to their site of injury, time of repair and procedures. Assistant treatment as pressure dressing was adopted thereafter. All patients experienced an uneventful recovery at the time of finalizing the study. Two patients received Stensen's duct ligation, 5 received microsurgical anastomosis and 2 accepted salivary flow diversion for 5 patients with sialoceles and 4 patients with fistulas, and no re-occurrence was found. Facial paralysis occurred after surgery in 4 patients, and 3 of them recovered after the nerve nutrition treatment. Our study suggested that appropriate surgical treatment is efficient for the re-establishment of the tissue function and facial aesthetic for delayed injury of the parotid and its duct.

Up-regulation of syncytin-1 contributes to TNF-α-enhanced fusion between OSCC and HUVECs partly via Wnt/β-catenin-dependent pathway

Accumulating evidence implies that cell fusion is one of the driving forces of cancer invasion and metastasis. However, considerably less is still known about the triggering factors and underlying mechanisms associated with cancer-host cell fusion, particularly in inflammatory tumor microenvironment. In this study, we confirmed that inflammatory factor TNF-α could enhance fusion between squamous cell carcinoma cells 9 (SCC-9) and human umbilical vein endothelial cells (HUVEC). Further study revealed that TNF-α could promote up-regulation of syncytin-1 in SCC-9 and its receptor neutral amino acid transporter type 2 (ASCT-2) in HUVEC. Syncytin-1 acted as an important downstream effector in TNF-α-enhanced cancer-endothelial cell fusion. TNF-α treatment also led to the activation of Wnt/β-catenin signal pathway in SCC-9. The activation of Wnt/β-catenin signal pathway was closely associated with the up-regulation of syncytin-1 in SCC-9 and increased fusion between SCC-9 and HUVEC while blocking of Wnt/β-catenin signal pathway resulted in the corresponding down-regulation of syncytin-1 accompanied by sharp decrease of cancer-endothelial cell fusion. Taking together, our results suggest that Wnt/β-catenin signal pathway activation-dependent up-regulation of syncytin-1 contributes to the pro-inflammatory factor TNF-α-enhanced fusion between oral squamous cell carcinoma cells and endothelial cells.

EphA2 silencing promotes growth, migration, and metastasis in salivary adenoid cystic carcinoma: in vitro and in vivo study

EphA2 is associated with tumor growth and distant metastasis in numerous human tumors. Considering the controversial effects of EphA2 in different tumors and the lack of reports in salivary adenoid cystic carcinoma (SACC), we evaluated the effects of EphA2 inhibition by short hairpin RNA on SACC through in vivo and in vitro researches for the first time. Real-time reverse transcriptase-PCR and western blot analysis were conducted to verify the interference effect on SACC cells. Using Cell Counting Kit-8, wound healing, Transwell and Matrigel adhesion assays, we confirm that inhibition of EphA2 promotes the migration, invasion and adhesion ability of SACC cells. In vivo research, we prove that silencing of EphA2 significantly accelerates tumor growth and lung metastasis ability by establishing xenograft models in mice, including subcutaneous inoculation and tail vein injection. In addition, immunostaining of EphA2, E-cadherin and Slug from 40 specimens and in vitro simulation of perineural invasion (PNI) assay imply that suppression of EphA2 partially contribute to epithelial-mesenchymal transition and enhancement of PNI in SACC. In conclusion, all the data suggest that EphA2 may act as a tumor suppressor in SACC progression.

Oral cancer/endothelial cell fusion experiences nuclear fusion and acquisition of enhanced survival potential

Most previous studies have linked cancer-macrophage fusion with tumor progression and metastasis. However, the characteristics of hybrid cells derived from oral cancer and endothelial cells and their involvement in cancer remained unknown. Double-immunofluorescent staining and fluorescent in situ hybridization (FISH) were performed to confirm spontaneous cell fusion between eGFP-labeled human umbilical vein endothelial cells (HUVECs) and RFP-labeled SCC9, and to detect the expression of vementin and cytokeratin 18 in the hybrids. The property of chemo-resistance of such hybrids was examined by TUNEL assay. The hybrid cells in xenografted tumor were identified by FISH and GFP/RFP dual-immunofluoresence staining. We showed that SCC9 cells spontaneously fused with cocultured endothelial cells, and the resultant hybrid cells maintained the division and proliferation activity after re-plating and thawing. Such hybrids expressed markers of both parental cells and became more resistant to chemotherapeutic drug cisplatin as compared to the parental SCC9 cells. Our in vivo data indicated that the hybrid cells contributed to tumor composition by using of immunostaining and FISH analysis, even though the hybrid cells and SCC9 cells were mixed with 1:10,000, according to the FACS data. Our study suggested that the fusion events between oral cancer and endothelial cells undergo nuclear fusion and acquire a new property of drug resistance and consequently enhanced survival potential. These experimental findings provide further supportive evidence for the theory that cell fusion is involved in cancer progression.

Correlation of deregulated like-acetylglucosaminyl transferase and aberrant α-dystroglycan expression with human tongue cancer metastasis

PURPOSE

The present study examined the correlation of α-dystroglycan (α-DG) expression and like-acetylglucosaminyl transferase (LARGE) with metastasis of human tongue cancer.

MATERIALS AND METHODS

Fifty human tongue cancer tissues and 2 tongue squamous cell carcinoma cell lines (CAL27 and SCC4) were involved. Immunohistochemistry was used to detect the expression of α-DG and LARGE. Methylation-specific polymerase chain reaction was performed to assess the methylation status of the LARGE gene promoter. CAL27 and SCC4 cells were transfected with exogenous LARGE and treated with 5-aza-2'-deoxycytidine (Aza-dC), respectively. Glycol sites of α-DG were detected by western blotting. In addition, the laminin overlay assay, cell adhesion assay, and invasion assay were performed.

RESULTS

Immunohistochemical results showed that decreased expression of VIA4-1 and IIH6 (antibodies that recognize the glycol sites of α-DG) were correlated with the lymph node metastasis of tongue cancer (n = 50; P = .016 and .025, respectively). Decreased LARGE expression and hypermethylation of the LARGE gene promoter were correlated with lymph node metastasis and α-DG glycosylation in human tongue cancer (n = 50; P = .043 and .015 respectively). In addition, LARGE overexpression and Aza-dC treatment actively led to restoration of functional α-DG expression, elevation of laminin binding, and decrease of migratory ability in cancer cells.

CONCLUSION

The results suggested that absent α-DG expression and LARGE deregulation were closely associated with nodal metastasis of tongue cancer. Aberrant α-DG expression and glycosylation were attributed at least in part to the abnormal epigenetic modification of LARGE, especially the hypermethylation of its promoter.

Alterations of high endothelial venules in primary and metastatic tumors are correlated with lymph node metastasis of oral and pharyngeal carcinoma

High endothelial venules (HEVs) are special blood vessels in the paracortical region of lymph nodes (LNs) and govern lymphocyte recruitment. LN metastasis has similarity to circulating lymphocytes homing to LNs, but the role of HEVs in the progression of oral and pharyngeal squamous cell carcinoma (OPSCC) is unclear. In this study, we found that HEVs experienced a series of morphological and functional changes during OPSCC progression and were correlated with LN metastasis. In 9 cases of 73 metastatic LNs, tumor emboli were located adjacent to HEVs or just out of the vessels but not lymphatic channels. Gap junctions of tumor cells close to HEVs decreased or disappeared, and gaps were left at contact points where tumor cells attached to the HEVs. Moreover, the proliferation rate of endothelial cells of HEVs was the highest in metastatic LNs. Finally, L-selectin was detected in both primary and metastatic tumors, and it facilitated tumor cells adhering to LNs. In conclusion, our findings suggest that remodeled HEVs are correlated with LN metastasis of OPSCC and play important role in this process by preparing premetastatic soil for cancer cell metastasis.

Ephrin-A1 is up-regulated by hypoxia in cancer cells and promotes angiogenesis of HUVECs through a coordinated cross-talk with eNOS

Hypoxia, ephrin-A1 and endothelial nitric oxide synthase (eNOS) have been proved to play critical roles in tumor angiogenesis. However, how ephrin-A1 is regulated by hypoxia and whether ephrin-A1 cooperates with eNOS in modulation of angiogenesis remain to be addressed in details. Here we demonstrated that both ephrin-A1 in squamous cell carcinoma cells (SCC-9) and especially soluble ephrin-A1 in the supernatants were up-regulated under hypoxic condition. An increased nitric oxide (NO) production in human umbilical vein endothelial cells (HUVECs) was observed in ephrin-A1-induced angiogenesis which was reversed after co-culture with eNOS specific inhibitor, N-nitro-L-arginine methyl ester hydrochloride (L-NAME). Western blot analysis confirmed that both phosphorylation of Akt_Ser473 and eNOS_Ser1177 were up-regulated in ephrin-A1-stimulated HUVECs, with the total eNOS expression unchanged. The specific inhibitor of phosphatidylinositol 3-kinase (PI3K), LY294002, significantly down-regulated ephrin-A1-induced expression of phosphorylated Akt_Ser473 as well as phosphorylation of eNOS_Ser1177. These results revealed a possible novel mechanism whereby ephrin-A1 is regulated in tumor microenvironment and promotes angiogenesis through a coordinated cross-talk with PI3K/Akt-dependent eNOS activation which may relate to normal vascular development and tumor neovascularization.

Upregulation of Serum and Tissue Vascular Endothelial Growth Factor Correlates With Angiogenesis and Prognosis of Oral Squamous Cell Carcinoma

PURPOSE

To investigate both serum vascular endothelial growth factor (VEGF) concentrations and VEGF expression in patients with oral squamous cell carcinoma (OSCC), and to clarify whether upregulation of VEGF in OSCC patients is associated with increased microvessel density and various clinicopathologic features of patients with OSCC.

PATIENTS AND METHODS

The study population included 31 patients with OSCC and 10 normal individuals. Concentration of serum VEGF was determined by using an ELISA kit. Immunohistochemistry was used to evaluate VEGF expression and microvessel density in OSCC.

RESULTS

Our results showed that both serum VEGF levels and VEGF positivity were closely associated with both regional lymph node status and clinical stage of patients with OSCC. Increased microvessel density in oral cancer tissues was significantly higher in VEGF-positive tumors than VEGF-negative tumors.

CONCLUSION

Our present study indicated that upregulation of VEGF in oral cancer was correlated with both tumor angiogenesis and disease severity.

[Function of disk reposition in the treatment of traumatogenic temporomandibular joint ankylosis]

OBJECTIVE

To investigate the method and results of disk reposition in the treatment of traumatogenic TMJ ankylosis.

METHODS

In 19 cases of traumatogenic ankylosis of TMJ, the dislocated disks were repositioned during anthroplasty. In the operation, the dissection of dislocated disk was performed carefully around the TMJ. The disk was repositioned to its anatomic location over the top of condylar stump, then the lateral aspect of the disk was sutured to the soft tissue of zygomatic root.

RESULTS

At the last follow-up examination, interincisal opening distance ranged from 24 to 43 mm in all cases (mean 32.63 mm), which approached or reached the normal level. No recurrence and TMJ symptom were found during the period of follow-up.

CONCLUSIONS

The disk repositioning in treatment of traumatogenic TMJ ankylosis is a feasible and effective approach to reconstruct the structure and function and prevent recurrence.

Circulating levels of vascular endothelial growth factor in patients with oral squamous cell carcinoma

Angiogenesis is a crucial step in tumour growth, progression, and metastasis. Recently, many angiogenic factors have been identified. Vascular endothelial growth factor (VEGF) is thought to be one such angiogenic factor and is also thought to be a selective mitogen for vascular endothelial cells. The present study was designed to determine the circulating levels of VEGF in human oral squamous cell carcinoma (OSCC) and to investigate its correlation with the clinicopathologic features and prognosis. The study consisted of 10 healthy volunteers and 31 patients with OSCC. A quantitative sandwich enzyme immunoassay technique was used to measure the concentrations of VEGF in the sera. The data obtained from the experiment were analysed with independent-samples t-test. The mean concentrations of serum VEGF were 148.80 +/- 64.17 pg x ml(-1) (range, 59-231 pg x ml(-1)) in normal controls and 567.97 +/- 338.17 pg x ml(-1) (range, 136-1,892 pg x ml(-1)) in OSCC group. Statistical analysis showed that the mean VEGF level in sera of OSCC patients was significantly higher than that in healthy controls (P<0.001). The serum VEGF levels of OSCC patients correlated with condition of nodal metastasis (P<0.05) and clinical stage (P<0.05) but not with sex (P>0.05) and degree of differentiation (P>0.05). Our study showed that OSCC was associated with significantly elevated serum VEGF concentration. Higher level of serum VEGF also correlated with lymph node metastasis and clinical stage of OSCC. Determination of serum VEGF concentration may be helpful to distinguish OSCC patients from the normal individuals.

Effects of exogenous nitric oxide on oral squamous cell carcinoma: an in vitro study

PURPOSE

Nitric oxide (NO) is a newly found unstable free radical gas, serving as an important mediator, messenger, and signal transduction molecule and involved in a variety of pathophysiologic processes. Recently, NO has been reported to have cytotoxic effects on several tumor cells as an effector molecule of activated macrophage. The objective of this study was to investigate the effects of exogenous NO on oral squamous cell carcinoma cell line and to try to clarify the possible mechanisms by which it kills tumor cells.

METHODS

TSCCa cell line, established from a patient with oral squamous cell carcinoma of the tongue, was exposed to various concentrations of exogenous NO that were released from an NO donor, sodium nitroprusside (SNP), for 48 hours. Nitrite/nitrate levels in the culture supernatant were determined with a commercial available NO kit. Both morphologic and ultrastructural changes were evaluated by reverse phase contrast microscopy or transmission electron microscopy. The DNA was harvested from SNP-treated or untreated TSCCa cells and assessed by agarose gel electrophoresis.

RESULTS

SNP released NO into medium in a dose-dependent manner. NO had a concentration-dependent cytotoxicity against TSCCa cells. NO induced tumor cell death through apoptosis, which was characterized by incompleteness of nuclear membrane, disappearance of nucleole and nuclear condensation, chromatin margination, or chromatin homogenization. Agarose gel electrophoresis showed a typical internucleosomal DNA cleavage pattern (DNA ladder), a reliable indicator of apoptosis.

CONCLUSIONS

Our results suggested that NO had a tumoricidal potential against oral cancer cells. NO might exert its cytotoxicity as an effector molecule of activated microphage through at least apoptosis.