Lizhong Liang

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.

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).

Mandible Reconstruction Assisted by Preoperative Simulation and Transferring Templates: Cadaveric Study of Accuracy

PURPOSE In this study we tried to define tumor resection, fibula cutting, and positioning by surgical templates to perform the mandible reconstruction surgery according to the preoperative simulation. The accuracy was evaluated through cadaveric surgery. MATERIALS AND METHODS Five cadaveric mandibles and fibulas were obtained. Preoperative surgical simulation was performed. Surgical templates that defined tumor resection, fibula cutting, and positioning were designed and fabricated. Translation, angular deviation, and rotation of bone grafts, as well as translation of condyles, were measured. RESULTS The reconstructed mandibles showed high similarity to the surgical planning. The mean translation, angular deviation, and rotation of fibula segments of the reconstructed mandibles were 1.35 ± 0.86 mm, 3.36° ± 1.86°, and 8.13° ± 5.35°, respectively. In the mandible remnants, the translation of condyles was measured, with a mean of 1.39 ± 0.66 mm. CONCLUSIONS Our method of defining the tumor resection, fibula cutting, and positioning by surgical templates was accurate enough for mandible reconstruction surgery.

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.

MALAT1 induces tongue cancer cells' EMT and inhibits apoptosis through Wnt/β-catenin signaling pathway.

BACKGROUND MALAT1 is recognized as an oncogenic lncRNA in various malignancies. However, its expression and function in oral tongue squamous cell carcinoma are still unknown. This study aims to investigate the expression and function of MALAT1 in TSCC tissues and cells. MATERIALS AND METHODS qPCR was performed to detect the expression of MALAT1. MALAT1 was suppressed and upregulated by plasmid transfection in TSCC cells, and then cell migration, invasion, EMT, and apoptosis were analyzed. RESULTS LncRNA MALAT1 was upregulated in TSCC tissues and correlated with cervical lymph node metastasis in TSCC patients. Moreover, MALAT1 induced cell migration, invasion, EMT, and inhibited apoptosis by modulating Wnt/β-catenin signaling pathway. Finally, inhibiting Wnt/β-catenin signaling pathway attenuated the effect of exogenous MALAT1. CONCLUSION In summary, upregulated MALAT1 in TSCC promoted EMT and inhibited cell apoptosis by modulating Wnt/β-catenin signaling pathway.

Myeloid-derived suppressor cells contribute to oral cancer progression in 4NQO-treated mice.

OBJECTIVE Abnormal myelopoiesis especially the expansion of myeloid-derived suppressor cells (MDSCs) is increasingly recognized as an important reason for the escape of tumor from immune surveillance. This study aims to investigate the role of this specific population of cells in oral cancer progression. MATERIALS AND METHODS 4-Nitroquinoline 1-oxide (4NQO) was used to induce oral cancer in C57BL/6 mice. The tongue mucosa was examined by hematoxylin and eosin staining. The distribution of MDSCs in the spleen and peripheral blood and T cell subsets in the spleen was analyzed by flow cytometry. The expression of MDSCs in the tongue tissues was investigated by immunohistochemical staining, and the expression of arginase-1 (ARG-1) and NOS-2 in the tongue tissues was detected by real-time PCR. RESULTS   We found that during tumor progression, significantly increased frequency of MDSCs was observed in the spleens and peripheral blood of 4NQO-treated mice, and the frequency of MDSCs in the spleens was positively correlated with systemic CD3(+) CD8(+) T cells. Moreover, 4NQO-treated mice showed significantly higher MDSCs infiltration and ARG-1 mRNA level in the tumor site. CONCLUSIONS Myeloid-derived suppressor cells contribute to oral tumor progression and represent a potential target for immunotherapy of oral cancer.

Mandibular Reconstruction Assisted by Preoperative Simulation and Accurate Transferring Templates: Preliminary Report of Clinical Application

PURPOSE This study investigated the application of a computer-aided design and manufacturing technique of defining tumor resection, fibula cutting, and positioning by surgical templates in mandibular reconstructive surgery. MATERIALS AND METHODS Four patients who required mandibulectomy and simultaneous reconstruction were enrolled in this study. Preoperative surgical simulation was performed. The surgical templates that defined tumor resection, fibula cutting, and positioning were designed and fabricated. RESULTS The surgeries were performed to the preoperative plan. All flaps survived. Superimposition of the postoperative image and the preoperative plan showed a satisfactory surgical accuracy. CONCLUSIONS This method of defining tumor resection, fibula cutting, and positioning by surgical templates was accurate enough for mandibular reconstructive surgery.

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.

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.

A meta-analysis on selective versus comprehensive neck dissection in oral squamous cell carcinoma patients with clinically node-positive neck

OBJECTIVE Properly management of cervical lymph node metastases is a critical treatment for patients with oral squamous cell carcinoma (OSCC). However there is no consensus on the optimal treatment for oral cancer patients with clinically node-positive (cN+) neck. This study aims to access the feasibility of selective neck dissection in oral cancer patients with cN+neck. METHOD We searched PubMed and EMBASE up to April 2015 to identify the studies which compared selective neck dissection (SND) with comprehensive neck dissection (CND) in OSCC patients with cN+neck. Data were extracted by two authors. The meta-analysis was conducted with regional recurrence and disease specific death as primary endpoints. RESULT Five studies with a total of 443 patients met our inclusion criteria. No significant difference was found regarding regional recurrence, disease specific death or overall death between the SND and CND group. CONCLUSION These findings suggest that cN+OSCC patients treated with SND in conjunction with adjuvant therapy got comparable clinical outcome to CND.