LncRNA UCA1/miR-124 axis modulates TGFß1-induced epithelial-mesenchymal transition and invasion of tongue cancer cells through JAG1/Notch signaling.

Tongue cancer remains a massive threat to public health due to the high rate of metastasis. Tumor cell epithelial-mesenchymal transition (EMT), which can be induced by transforming growth factor ß1 (TGFß1), has been regarded as a significant contributor to cancer invasion and migration. In our previous study, long noncoding RNA (lncRNA) MALAT1/miR-124/JAG1 axis modulates the growth of tongue cancer. In addition to metastasis-associated lung adenocarcinoma transcript 1 (MALAT1), another lncRNA, urothelial cancer associated 1 (UCA1), can promote EMT and cancer metastasis. In the present study, UCA1 was overexpressed in tongue cancer tissues and cell lines. UCA1 overexpression was correlated to the poorer prognosis of patients with tongue cancer. UCA1 knockdown significantly suppressed TGFß1-induced tongue cancer cell invasion and EMT by decreasing vimentin and increasing E-cadherin. Regarding the molecular mechanism, UCA1 could directly bind to microRNA-124 (miR-124) and negatively regulate each other. UCA1 knockdown ameliorated, whereas miR-124 inhibition exacerbated TGFß1-induced EMT and invasion in tongue cancer cells through miR-124 downstream jagged 1 (JAG1) and Notch signaling. Moreover, miR-124 inhibition partially impaired the effect of UCA1 knockdown. In tongue cancer tissues, miR-124 expression was remarkably decreased, whereas JAG1 mRNA expression was increased. miR-124 was negatively correlated with UCA1 and JAG1. UCA1 and JAG1 were positively correlated. In summary, we provided a novel mechanism by which the EMT process and cancer cell invasion in tongue cancer could be modulated from the perspective of lncRNA-miRNA-mRNA regulation.

Suppression of tongue squamous cell carcinoma growth by inhibition of Jagged1 in vitro and in vivo.

BACKGROUND: The changes in Notch signaling are closely related to the occurrence and development of many cancers. We have investigated Notch signaling receptor and its ligand expressions in TSCC cell lines, tissues and its significance. We clarified Notch signaling pathway in TSCC and its mechanism. We regulated Notch signaling pathway of tumor cells, thereby inhibiting tumor cell proliferation and differentiation. METHODS: We detected Jagged1 protein and mRNA expression levels in specimens (tongue cancer and adjacent tissues) from 74 patients with tongue cancer and in TSCC cell line. The Jagged1-targeted lentiviral vector RNAi system was constructed, and its suppressive effects on the proliferation and invasion of tongue carcinoma cells in in vivo and ex vivo were determined. RESULTS: Jagged1 was expressed in tongue squamous cell cancer tissues and cell line, but there were differences in its expression. Jagged1 was knocked down and the tumor growth was inhibited accompanying cell cycle changes. Animal studies also showed that the tumor growth was inhibited. CONCLUSIONS: Jagged1 may be involved in the differentiation and proliferation of tongue cancer. Targeting Jagged1 RNA interference lentiviral vector can effectively lower Jagged1 mRNA and protein expression levels of Tca8113 cells, thereby preventing the proliferation of TSCC cells. Jagged1 is expected to be a promising new target for curing tongue cancer. In-depth study of the interaction between Jagged1 and other molecules of Notch signaling pathway in the process of carcinogenesis has important theoretical guidance and clinical significance in revealing the mechanism of Jagged1 and its application in the therapy for tongue cancer.

Disruption of mediator complex subunit 19 (Med19) inhibits cell growth and migration in tongue cancer.

BACKGROUND: Mediator complex subunit 19 (Med19) is a critical subunit of the mediator complex that forms a bridge between the transcription factors and RNA polymerase II. Although it has been reported that Med19 plays an important role in stabilizing the whole mediator complex, its biological importance in tongue cancer cell proliferation and migration has not been addressed. METHODS: By using MTT, BrdU incorporation, colony formation, flow cytometric, tumorigenesis and transwell assays, We tested the Med19 role on tongue cancer cell growth and migration. RESULTS: We demonstrated that lentivirus-mediated Med19 knockdown could arrest tongue cancer cells at G1 phase, inhibit tongue cancer cell proliferation and migration in vitro. The tumorigenicity of Med19 short hairpin RNA (shRNA)-expressing lentivirus infected tongue cancer cells were decreased after inoculating into nude mice. CONCLUSIONS: These results indicate that Med19 plays an important role in tongue cancer proliferation and migration, and suggest possible applications for tongue cancer therapy.

High expression of the autophagy gene Beclin-1 is associated with favorable prognosis for salivary gland adenoid cystic carcinoma.

BACKGROUND: Although autophagy is universally involved in tumorigenesis and tumor progression, the roles of autophagy and autophagy-regulating genes in salivary gland adenoid cystic carcinoma (ACC) remain unknown. In this study, we investigated the expression of the autophagy-regulating genes Beclin-1, death-associated protein kinase-1, ultraviolet radiation resistance-associated gene, and phosphatase and tensin homolog in salivary gland ACC samples. METHODS: Immunohistochemistry and real-time polymerase chain reaction were used to analyze the expression of these genes in 89 ACC samples and normal salivary gland tissue samples. The relationship of their expression with clinicopathological features was analyzed. RESULTS: The data showed significantly lower expression of these genes in the tumor samples than in normal salivary gland tissue samples. Furthermore, Beclin-1 expression was significantly correlated with histological pattern of ACC (P<0.05), and high expression of ultraviolet radiation resistance-associated gene was associated with distant metastasis (P<0.05). Most importantly, univariate and multivariate survival analyses suggested that Beclin-1 protein and mRNA expression in cancer cells were independent prognostic indicators for ACC. CONCLUSION: Our results suggest that autophagy-regulating genes may participate in the pathogenesis of salivary gland ACC. Further research will be required to gain a better understanding of autophagy in ACC.

Activation of Notch signaling in human tongue carcinoma.

BACKGROUND: Involvement of Notch signaling in several tumors is well known, but its role in tongue squamous cell carcinoma remains poorly characterized. The purpose of this study was to evaluate the roles of Notch signaling in the oncogenesis of tongue carcinoma. MATERIALS AND METHODS: Tumor specimens and adjacent non-neoplastic tongue tissues from 74 patients with tongue carcinoma and human tongue carcinoma cell line Tca8113 were examined using immunohistochemistry and RT-PCR to determine the expressions of Notch1, Notch3, Jagged1, and Jagged2. RESULTS: The mRNA expressions of Notch1, Notch3, Jagged1, and Jagged2 were detected in Tca8113, tongue carcinoma, and adjacent non-neoplastic tongue tissues. The expression levels of mRNAs in tongue carcinoma were higher than those in adjacent non-neoplastic tongue tissues (P < 0.05). Immunohistochemical examination showed that the Notch signal molecules were expressed in Tca8113, tongue carcinoma, and adjacent non-neoplastic tongue tissues. The expression rates of Notch1 and Notch3 protein in tongue carcinoma were higher than those in adjacent non-neoplastic tongue tissues (χ² = 6.10, P = 0.013; χ² = 3.94, P = 0.047). Notch1 and jagged1 were significantly more highly expressed in lymph node metastasis-positive tongue carcinoma (χ² = 6.108, P = 0.013; χ² = 7.354, P = 0.025). In addition, expressions of Notch3 and Jagged2 were highly correlated in tongue carcinoma tissues (χ² = 42.130, P < 0.001). CONCLUSIONS: Expressions of Notch receptors and ligands in tongue carcinoma and adjacent non-neoplastic tongue tissues suggest that Notch signaling may control cell differentiation and proliferation of carcinoma cells. The disorder of Notch signaling may be a mechanism of the tongue carcinoma development.

Detection of Notch signaling molecules in cemento-ossifying fibroma of the jaws.

BACKGROUND: The aim of this study was to evaluate the roles of Notch signaling in the oncogenesis and cytodifferentiation of cemento-ossifying fibroma, the expressions of Notch receptors and ligands were detected in COF and normal jaw bones. MATERIALS AND METHODS: The expressions of Notch1, Notch3, Jagged1, and Jagged2 were detected by reverse transcriptase polymerase chain reaction and immunohistochemistry respectively in 16 cases of normal bone tissues and 12 cases of COF of the jaws. RESULTS: The mRNAs expressions of Notch1, Notch3, Jagged1, and Jagged2 were detected in all specimens. The expression levels of mRNAs in COF were higher than those in normal bones. In COF, Notch proteins staining were showed extensively distribution in fibroblasts and osteoblasts. In normal bone tissue, Notch proteins were expressed in osteoblasts, whereas proteins staining were weaker than those in COF, but no detection in fibroblast-like bone marrow stroma cells. The expressions of Notch receptors and ligands were not detected in cementum-like products or bone matrices. CONCLUSION: Our data suggest that Notch signaling may participate in controlling cell differentiation and proliferation in normal bone and COF of the jaws. Notch signaling disorder may be a molecular incident in COF occurrence and development.

[Retracted] Long non­coding RNA MALAT1 interacts with miR­124 and modulates tongue cancer growth by targeting JAG1.

We wish to retract our research article entitled "Long non­coding RNA MALAT1 interacts with miR­124 and modulates tongue cancer growth by targeting JAG1" published in Oncology Reports 37 2087­2094, 2017. Following the publication of this article, it was drawn to our attention that this paper bore numerous similarites with an article published previously in the journal OncoTargets and Therapy. Although all the data reported in our study were original, we recognize that it was not appropriate that we should have modelled our paper on previously published articles as a template on which to base the writing of our paper. Therefore, we have agreed to follow the Editor's recommendation that this paper be retracted from the publication. All the named authors agree to this retraction. We sincerely apologize to the Editor and the readership of the Journal for our action, and regret any inconvenience this has caused. [the original article was published in the Oncology Reports 37: 2087­2094, 2017; DOI: 10.3892/or.2017.5445].

Long non-coding RNA MALAT1 interacts with miR-124 and modulates tongue cancer growth by targeting JAG1.

Metastasis-associated lung adenocarcinoma transcript 1 (MALAT1), a long non-coding RNA (lncRNA), was the earliest discovered to be correlated with cancer and contributes to the initiation and development of several types of tumors. Dysregulation of MALAT1 expression is frequently observed in many types of cancer such as gastric cancer, esophageal squamous cell carcinoma and glioma. To date, the role of MALAT1 and the underlying mechanisms in tongue cancer development remain unclear. In the present study, we studied the influence of MALAT1 on tongue cancer cell lines and clinical tongue cancer samples so as to detect its function and the underlying mechanism. In the present study, lncRNA-MALAT1 was specifically upregulated in tongue cancer cell lines and overexpression promoted tongue cancer cell growth by targeting miR-124. Knockdown of MALAT1 suppressed the growth and invasion of human tongue cancer cells and inhibited metastasis in vitro and in vivo. In addition, miR-124-dependent jagged1 (JAG1) regulation was required for MALAT1-induced tongue cancer cell growth. Our data revealed that MALAT1 inhibited tongue cancer cell growth and metastasis through miR-124-dependent JAG1 regulation. In conclusion, we revealed that MALAT1 may play an oncogenic role by increasing proliferation and metastasis of tongue cancer and is a potential therapeutic target in human tongue cancer.

Improvement in the delivery system of bone morphogenetic protein-2: a new approach to promote bone formation.

Much research has been focused on developing bone morphogenetic protein-2(BMP-2) delivery systems to enhance bone formation in bone defect repair and bone tissue engineering. However, many of these current systems have several drawbacks associated with low loading efficiencies and reduced biological activities after release. Collagen scaffolds can be used as in delivery systems because of their biocompatibility. However, growth factors have naturally low affinity to collagen, which is disadvantageous for maintaining a sufficient growth factor concentration at the delivery sites. To enhance BMP-2 binding to collagen scaffolds, we chose a porous collagen scaffold that was chemically modified using Traut's reagent. The modified collagen scaffold allows cross-linking of the collagen fibers and is able to immobilize more BMP-2 after treatment with Sulfo-SMCC. We demonstrated that cross-linking led to a slower release rate of BMP-2, but did not reduce its biological activity. Moreover, more ectopic bone formation was induced by subcutaneous implants of cross-linked collagen treated with BMP-2. We concluded that collagen scaffolds chemically conjugated with BMP-2 using Traut's reagent and Sulfo-SMCC was an effective delivery system for use in bone defect repair and in bone tissue engineering.

Mandible reconstruction assisted by preoperative virtual surgical simulation.

OBJECTIVE: In this study, we evaluated the clinical efficacy of mandible reconstruction with preoperative virtual planning, which focused on esthetics and occlusion. STUDY DESIGN: A series of 9 patients were enrolled prospectively to undergo mandibulectomy and simultaneous reconstruction. Preoperative spiral CT scans of the maxillofacial region and the fibula region were performed. Virtual surgery of tumor resection and fibula reconstruction was performed in the Mimics platform. The reconstructed mandible models were fabricated with CAD/CAM technique. The reconstruction plate and the positioning template were accommodated to the stereolithographic model as the surgical template. RESULTS: Surgery was performed accurately according to the templates. All the fibula flaps survived. The appearance and occlusion of the patients were satisfactory. CONCLUSIONS: With preoperative virtual planning, the spatial relationship of the mandible and the fibula graft can be planned individually, which helps achieve optimum appearance and occlusion relationship.

Foxp3 expressed by tongue squamous cell carcinoma cells correlates with clinicopathologic features and overall survival in tongue squamous cell carcinoma patients.

The forkhead transcription factor, Foxp3, has been identified as a key player in CD4(+)CD25(+)Foxp3(+) regulatory T cells (Tregs) function and a definitive marker of Tregs. Recently, it was reported that Foxp3 could be expressed by tumor cells themselves. The present study was to investigate the expression of Foxp3 in tongue squamous cells carcinoma (TSCC) cells and its clinical significance. In this study, the expression of Foxp3 by TSCC cells was demonstrated in TSCC tissue samples and three TSCC cell lines using immunohistochemical staining, realtime-PCR and Western blotting, and its clinical significance were statistically analyzed. The immunohistochemical assay in TSCC paraffin-embedded samples showed positive staining in 48 of 81 (59.3%) cases. The expression was significantly associated with pathologic differentiation (P=0.040) and T stage (P=0.000), and furthermore, inversely associate with patient survival (P=0.021). Multivariate analysis (Cox regression) suggested that Foxp3 expression in TSCC cells was an independent prognostic indicator for TSCC (P=0.032).

[A comparison of three methods in establishing transplanted model of VX2 tongue carcinoma in rabbits].

OBJECTIVE: To establish transplanted models of VX2 tongue carcinoma in rabbits by three methods and compare these models. METHODS: After establishment of VX2 tumor-bearing rabbits, 72 New-Zealand white rabbits were randomly divided into 3 groups. Intact tumour tissue, modified tumour cell suspension, tumour cell suspension were respectively injected into the middle-third lateral border of the tongues of rabbits in 3 groups to induce transplanted VX2 tongue carcinoma. The histological features, the tumour-take rates and the metastasis rates of the 3 models were observed. RESULTS: The tumour-take rate of 3 models were 83.3%, 91.7% and 33.3% respectively; the lymph node metastasis rates were 71.4%, 100.0% and 37.5% respectively; the lung metastasis rates were 35.7%, 81.3% and 0 respectively. The histological features of the transplanted VX2 tongue carcinoma of 3 models were all consistent with those of moderately differentiated carcinoma. CONCLUSION: The biological properties of the transplanted VX2 tongue carcinoma of 3 models is much alike to tongue carcinoma in humans. The model established with modified tumor cell suspension is considered to be more suitable for tongue cancer study.