Relationship Between O-GlcNAcase Expression and Prognosis of Patients With Osteosarcoma.

Several studies have demonstrated a role of O-GlcNAcylation (O-GlcNAc) in tumorigenesis of various carcinomas by modification of tumor-associated proteins. However, its implication in the pathogenesis of osteosarcoma remains unclear. This study aimed to investigate the levels of O-GlcNAc and the expressions of O-linked N-acetylglucosamine transferase (OGT) and O-GlcNAcase (OGA) in human osteosarcoma tissues, by using immunohistochemistry; and to find correlations between the levels or expressions and several clinicopathologic parameters. There were 109 first diagnosed osteosarcoma patients, including Enneking stage IIB (n=70) and III (n=39). Correlations between the immunoreactive score (IRS) and clinicopathologic parameters, overall survival, and metastasis-free survival were evaluated. A positive correlation was found between the IRS of OGA and the percentage of postchemotherapeutic tumor necrosis (r=0.308; P=0.017). Univariate analysis revealed significantly lower OGA IRS in metastatic patients (P=0.020) and poor chemotherapeutic-responder patients (P=0.001). By multivariate analysis, presence of tumor metastasis (P=0.002) and lower OGA IRS (P=0.004) was significantly associated with shorter overall survival. Subgroup analysis in stage IIB osteosarcoma (n=70) demonstrated that male sex (P=0.019), presence of tumor recurrence (P=0.026), poor chemotherapeutic responder (P=0.022), and lower OGA IRS (P=0.019) were significantly correlated with short metastasis-free survival. But, lower OGA IRS was the only independent predictor for short metastasis-free survival (P=0.006). Our findings suggested that O-GlcNAc pathway, especially OGA, may involve in pathogenesis and aggressiveness of osteosarcoma. Low level of OGA expression may be used as a poor prognostic indicator.

Overexpression of methyltransferase-like 3 and 14 in oral squamous cell carcinoma.

OBJECTIVES: This study aimed to determine expressions of methyltransferase-like 3 (METTL3) and METTL14, two enzymes essential for mRNA methylation at the adenosine (m6 A), in oral squamous cell carcinoma (OSCC) and to investigate in vitro aggressiveness of their aberrant expressions. METHODS: METTL3 and METTL14 expressions in 50 OSCC and 11 normal oral tissues were examined by immunohistochemistry. METTL3 and METTL14 expressions and m6 A amounts were determined in three OSCC cell lines, including HN5, HN6, and HN15. Cell proliferation, migration, and invasion were studied by BrdU, wound healing, and Transwell chamber assays, after silencing of METTL3, METTL14, or both by siRNA transfection. RESULTS: Immunostaining of METTL3 and METTL14 was localized in cancer cell nuclei. The mean percentages of METTL3- and METTL14-positive cells were significantly increased in OSCC tissues (p < 0.001). The percentages of METTL3- and METTL14-positive cells were correlated with the advanced pTNM stages (p < 0.05) and with the degrees of histopathological differentiation in OSCC (r = 0.564 and r = 0.316, respectively; p < 0.001). By the COX multivariate analysis, both overexpressed METTL3 and METTL14 were significantly associated with short overall survival (p < 0.05). Both METTL3 and METTL14 expressions and the m6 A amounts were significantly increased in HN6 (p < 0.05). Silencing of METTL3 and METTL14 in HN6 significantly inhibited cell proliferation (p < 0.01), but it failed to mitigate cell migration or invasion. CONCLUSIONS: METTL3 and METTL14 are overexpressed in OSCC tissues and in the HN6 OSCC cell line that promotes cell proliferation. Overexpressed METTL3 or METTL14 is found to be an independent prognostic factor for short overall survival in patients with OSCC.

Involvement of the A disintegrin and metalloproteinase 9 in oral cancer cell invasion.

The aims of this study were to determine the functional roles of the transmembrane glycoprotein, Disintegrin and metalloproteinase domain-containing protein 9 (ADAM 9), in the phosphorylation of epidermal growth factor receptor (EGFR) and AKT and in the aggressiveness of oral cancer cells. Immunohistochemistry and immunoblotting were conducted to determine expression of ADAM 9 and the levels of EGFR phosphorylated at the tyrosine 1173 residue (p-EGFRtyr1173 ) and AKT phosphorylated at the serine 473 residue (p-AKTser473 ) in oral cancer tissues and in the oral cancer cell lines HN5, HN6, HN15, and HN008. Small interfering RNA (siRNA) was used to inhibit expression of ADAM9 mRNA, and thus production of ADAM9 protein, in oral cancer cells. ADAM9-knockdown cells were examined for p-EGFRtyr1173 and p-AKTser473 levels and used for cell proliferation and invasion assays. A positive correlation among overexpression of ADAM 9, p-EGFRtyr1173 , and p-AKTser473 was found in oral cancer tissues. These biomolecules were also overexpressed in HN6 and HN15 cell lines. Expression of ADAM9 in HN6 and HN15 cells was statistically significantly inhibited by siRNA against ADAM9 mRNA (siADAM9) compared with the negative-control siRNA (scramble). The levels of p-AKTser473 , but not those of p-EGFRtyr1173 , were statistically significantly blocked by siADAM9. Although the proliferation rates of ADAM9 knocked-down HN6 and HN15 cells did not differ from those of cells exposed to scramble, a statistically significant decrease in cell invasion was found in these ADAM9-silenced cells. These results suggest a functional role of the ADAM 9/AKT signaling pathway in oral cancer cell invasion, which may be beneficial as a therapeutic target of oral cancer.

[Application of a modified paramedian lower lip-submandibular approach in maxillary (subtotal) total resection].

OBJECTIVE: To investigate the clinical efficacy of a modified paramedian lower lip-submandibular approach for maxillary (subtotal) total resection. METHODS: Eleven patients of maxillary tumors underwent maxillary (subtotal) total resection through the modified paramedian lower lip-submandibular approach. Clinical follow-up visits were conducted to evaluate appearance restoration, facial nerve functional status, parotid gland functional status, and orbital region complication. RESULTS: During the follow-up period of 6-36 months, the appearance of all 11 patients recovered well. All cases presented hidden scars. No facial nerve and parotid duct injury, lower eyelid edema, lower eyelid ectropion, or epiphora in all cases was observed. CONCLUSIONS: Applying modified paramedian lower lip-submandibular approach to maxillary (subtotal) total resection effectively reduces incidence of orbital region complications including lower eyelid edema, lower eyelid ectropion, and epiphora, which often occur to traditional approach. The modified approach produces more subtle scars than other methods and should be applied to treatment of maxillary (subtotal) total resection.

[Reconstruction of oral and maxillofacial soft tissue defects with anterolateral thigh (myocutaneous) flap assisted by computed tomography angiography].

Objective: To investigate the efficacy of anterolateral thigh (myocutaneous) flap designed with computed tomography angiography (CTA) to reconstruct oral and maxillofacial soft tissue defects. Methods: Between January 2011 and December 2015, 23 cases of oral and maxillofacial tumors were treated. There were 14 males and 9 females with the age range from 45 to 72 years (mean, 56.8 years). There were 12 cases of tongue carcinoma, 5 cases of buccal mucosa carcinoma, 4 cases of mouth floor carcinoma, and 2 cases of oropharynx carcinoma; all were squamous cell carcinoma. According to standard TNM staging of the Union for International Cancer Control (UICC), 8 cases were rated as T 2N 0M 0, 3 cases as T 2N 1M 0, 1 case as T 2N 2M 0, 4 cases as T 3N 0M 0, 2 cases as T 3N 1M 0, 2 cases as T 3N 2M 0, 2 cases as T 4N 1M 0, and 1 case as T 4N 2M 0. The course of disease was 1-6 months (mean, 2.4 months). CTA was performed before operation to locate the perforator vessel and its surface projection of emerging point and to design anterolateral thigh (myocutaneous) flap by computer. The defects of soft tissue ranged from 6 cm×4 cm to 11 cm×7 cm after resection of tumor. The flap was used to repair defects, including 14 thinned anterolateral thigh flaps, 7 anterolateral thigh myocutaneous flaps, and 2 anterolateral bilobed flaps; and the flap area ranged from 7 cm× 5 cm to 12 cm×8 cm. The donor sites were sutured directly. Results: CTA showed that myocutaneous perforators penetrated at the fascias of the vastus lateralis muscles in 22 cases with a location rate of 95.7% (22/23). Submandibular fistula occurred in 1 case at 5 days after operation and fistula healed after changed dressings. Other wounds at recipient site and donor site healed at primary stage. Anastomose with 2 vein was performed because of poor venous return in 1 case, and the flap survived. The other flaps survived well. All the patients were followed up 6-36 months (mean, 16.4 months). At 3 months after operation, the simplified recovery standard of speech function and swallow function was established according to the University of Washington Quality of Life Scale (UW-QOL). The speech and swallow function recovered satisfactorily in 22 cases, and not very satisfactorily in 1 case of well differentiated squamous cell carcinoma of the right mouth floor (T 4N 1M 0). No obvious tissue atrophy was observed in 23 cases. No dysfunction was found at the donor site. There was no tumor recurrence in 21 patients; 1 patient accepted the second operation due to lymphonodi metastasis of contralateral neck at 6 months after first operation, who died after 23 months; 1 patient died of distant metastasis at 10 months after first operation. Conclusion: The anterolateral thigh (myocutaneous) flap designed with CTA could well recover the morphology and function of the recipient site.

[EFFECT OF TRITON X-100 ON LIPOSOME MEDIATED BONE MORPHOGENETIC PROTEIN 2 BY TRANSFECTION OF RAT BONE MARROW MESENCHYMAL STEM CELLS].

OBJECTIVE: To study the effect of Triton X-100 promoting liposome-mediated bone morphogenetic protein 2 (BMP-2) gene transfection of rat bone marrow mesenchymal stem cells (BMSCs). METHODS: BMSCs were separated and cultured from the femur and tibia of healthy Wistar rats (8-week-old, male). The 3rd passage BMSCs identified by detecting the surface antigen were used to transfect. The optimum concentration of Triton X-100 for liposome mediated gene transfection was determined with ELISA meter by the way of MTT. In optimum concentration of Triton X-100, liposome mediated BMP-2 gene was transfected to BMSCs. The experiment was divided into 3 groups according to types of trasfection agents: BMSCs were transfected with Triton X-100+liposome+BMP-2 (experimental group), with liposome+ BMP-2 (conventional transfection group), and untransfected BMSCs served as blank control group. After 48 hours of transfecting, the green fluorescent protein (GFP) in cells was detected through inverted fluorescence microscope. After 72 hours of transfection, real-time fluorescence quantitative PCR was applied to measure the mRNA expression of BMP-2. RESULTS: 0.01% Triton X-100 was determined to be the optimum concentration for not only making the BMSCs maintain vitality, but also achieving a certain effect on BMSCs. After trasfecting for 48 hours, GFP was observed through inverted fluorescence microscope in the experimental group and conventional transfection group, but was not observed in the blank control group. After trasfecting for 72 hours, the relative BMP-2 mRNA expression level was 5.94 ± 0.12 in the experimental group, and was 4.99 ± 0.08 in the conventional transfection group, showing significant difference (t = 360.28, P = 0.02). The transfection efficiency was increased by 19% in the experimental group. CONCLUSION: 0.010% Triton X-100 can promote the liposome mediated BMP-2 gene transfection of rat BMSUs, and can improve the transfection efficiency.

[Vascularized composite flap with iliac crest and internal oblique muscle of abdomen for half mandibular reconstruction].

OBJECTIVE: To investigate the effect of vascularized composite flap with iliac crest and nternal oblique muscle of abdomen for half mandibular reconstruction. METHODS: From July 2009 to Sept. 2013, 14 cases with half mandibular defect after tumor resection were treated with composite flap of iliac crest and internal oblique muscle of abdomen pedicled by deep circumflex iliac vessels. During operation, one group performed tumor resection and got the recipient area vessels ready for anastomosis. The other group performed harvesting of composite flap. Then the flap was trimmed and fixed to construct the defect with vessel anastomosis. RESULTS: All the 14 composite flaps survived with local infection only in 1 case. The size of harvested iliac crest ranged from 6 cm x 3 cm to 9 cm x 3 cm. The size of harvested internal oblique muscle of abdomen ranged from 5 cm x 4 cm to 7 cm x 5 cm. The patients were followed up for 6 months to 26 months (mean, 13 months) with satisfactory results and no complication. Mandibular panoramic radiographs showed new bone formation and good union. CONCLUSIONS: Vascularized composite flap with iliac crest and internal oblique muscle of abdomen has the advantages of abundant bone volume, as well as soft tissue reconstruction in one stage. The reconstructed mandible can attain normal function and appearance.

Positive association between MTHFR C677T polymorphism and oral cancer risk: a meta-analysis.

Methylenetetrahydrofolate reductase (MTHFR) is a central enzyme involved in regulating the metabolic function of folate, which plays a pivotal role in DNA synthesis, repair, and methylation. The role of MTHFR C677T polymorphism in oral cancer risk has been reported with conflicting evidence. We conducted this study to appropriately estimate the effect size. We searched eligible studies in medicine-specific databases (PubMed, EMBASE, and Web of Knowledge) using (polymorphism) OR (polymorphisms) AND (methylenetetrahydrofolate reductase) OR (MTHFR) AND (oral cancer). A total of seven studies were summarized. This meta-analysis of the combined data showed a marginal association of MTHFR C677T polymorphism with oral cancer risk [odds ratio (OR) = 0.86, 95% confidence interval (CI) = 0.73-1.00 for CT vs. CC]. We also found decreased oral cancer risk in Asian population and hospital-based studies. Moreover, heavy drinkers were found to have a significantly higher risk of developing such cancer as compared to the non-heavy drinkers. These results suggest that MTHFR C677T polymorphism may play a role in oral cancer carcinogenesis in Asian population and heavy drinkers.