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Shen Z.,Guangdong Medical College | Jiang X.,Guangdong Medical College | Zeng C.,Guangdong Medical College | Zheng S.,Hainan Medical College | And 7 more authors.
BMC Cancer

Background: Overexpression of ubiquitin-conjugating enzyme 2C (UBE2C) has been detected in many types of human cancers, and is correlated with tumor malignancy. However, the role of UBE2C in human nasopharyngeal carcinoma (NPC) is unclear. In this study, we investigated the role of aberrant UBE2C expression in the progression of human NPC.Methods: Immunohistochemical analysis was performed to detect UBE2C protein in clinical samples of NPC and benign nasopharyngeal tissues, and the association of UBE2C expression with patient clinicopathological characteristics was analyzed. UBEC2 expression profiles were evaluated in cell lines representing varying differentiated stages of NPC and immortalized nasopharyngeal epithelia NP-69 cells using quantitative RT-PCR, western blotting and fluorescent staining. Furthermore, UBE2C was knocked down using RNA interference in these cell lines and proliferation and cell cycle distribution was investigated.Results: Immunohistochemical analysis revealed that UBE2C protein expression levels were higher in NPC tissues than in benign nasopharyngeal tissues (P<0.001). Moreover, high UBE2C protein expression was positively correlated with tumor size (P=0.017), lymph node metastasis (P=0.016) and distant metastasis (P=0.015) in NPC patients. In vitro experiments demonstrated that UBE2C expression levels were inversely correlated with the degree of differentiation of NPC cell lines, whereas UBE2C displayed low level of expression in NP-69 cells. Knockdown of UBE2C led to significant arrest at the S and G2/M phases of the cell cycle, and decreased cell proliferation was observed in poorly-differentiated CNE2Z NPC cells and undifferentiated C666-1 cells, but not in well-differentiated CNE1 and immortalized NP-69 cells.Conclusions: Our findings suggest that high expression of UBE2C in human NPC is closely related to tumor malignancy, and may be a potential marker for NPC progression. © 2013 Shen et al.; licensee BioMed Central Ltd. Source

Peng P.,Sun Yat Sen University | Ou X.,Sun Yat Sen University | Liao H.,Sun Yat Sen University | Liu Y.,Peoples Hospital of Zhongshan City | And 3 more authors.
Therapeutic Advances in Medical Oncology

Purpose: No standard salvage regimen has been established for patients with recurrent and metastatic nasopharyngeal carcinoma (NPC) and disease progression after prior platinum-based chemotherapy. This phase II study was designed to evaluate the efficacy and safety of gemcitabine plus S-1 (GS) chemotherapy as a remedial regimen in this setting. Methods: In this multicenter phase II study, 49 patients with recurrent and metastatic NPC who failed previous platinum-based chemotherapy received gemcitabine (1.0 g/m2 on days 1 and 8) plus oral S-1 chemotherapy (twice daily from day 1 to 14). Each cycle was repeated every 3 weeks for two cycles at least. The dose of S-1 was determined according to the body surface area (BSA): 40 mg twice a day for BSA <1.25 m2; 50 mg twice a day for 1.25 m2 ≤ BSA <1.5 m2; and 60 mg twice a day for BSA ≥1.5 m2. Results: Treatment was generally well-tolerated. A total of seven patients (14.3%) had grade 3 toxicities and the main toxicity was myelosuppression, whereas the nonhematology adverse events were minimal. There were 3 complete responses (6.4%), 17 partial responses (36.2%), and the overall response rate was 42.6% (95% confidence interval: 27.3-61.2). Median time to progression was 5.8 months and median survival was 14.8 months. The 1- and 2-year survival rates were 64% and 30%, respectively. Conclusions: Gemcitabine plus S-1 offers a satisfactory clinical activity and an acceptable safety profile for recurrent and metastatic NPC patients after failure of platinum-based chemotherapy. © The Author(s), 2016. Source

Liu Z.,Southern Medical University | Li X.,Southern Medical University | He X.,Peoples Hospital of Zhongshan City | Jiang Q.,Southern Medical University | And 6 more authors.
International Journal of Cancer

Human NESG1 (CCDC19) gene was originally isolated in our laboratory from human nasopharynx tissue. However, the biological and clinical significances of this gene remain largely unknown. In this report, two errors in the originally submitted sequence of human NESG1 gene were found, and the open reading frame sequence of NESG1 (Accession number: NM-012337.1) was revised and updated in the NCBI database (Accession number: NM-012337.2). The antibody raised against the revised sequence of NESG1 detected a single band of 66 kD in human nasopharynx tissues. NESG1 transcripts were specifically expressed in the nasopharynx epithelium. Expression of NESG1 transcripts and protein was downregulated or absent in nasopharyngeal carcinoma (NPC) tissues and cell lines in comparison to that in the normal nasopharynx tissues. The levels of NESG1 protein were significantly greater in the low-grade NPC tissues than that in the high-grade NPC tissues. Induced expression of NESG1 in otherwise NESG1-negative 5-8F cells not only significantly decreased cell proliferation, G1-S phase transition, but also markedly inhibited the ability of cell migration and invasion as well as in vivo tumorigenesis. Furthermore, NESG1 also significantly regulated the expression of cell cycle regulator CCNA1 and p21. Our findings first provided evidence that NESG1 may act as a tumor suppressor by inhibiting cell proliferation, invasion and migration of NPC cells. © 2010 UICC. Source

Tu L.,Southern Medical University | Liu Z.,Southern Medical University | He X.,Peoples Hospital of Zhongshan City | He Y.,Nanchang University | And 7 more authors.
Molecular Cancer

Background: The aim of the present study was to analyze the expression of eukaryotic translation initiation factor 4 gamma 1 (EIF4G1) in nasopharyngeal carcinoma (NPC) and its correlation with clinicopathologic features, including patients' survival time.Methods: Using real-time PCR, we detected the expression of EIF4G1 in normal nasopharyngeal tissues, immortalized nasopharyngeal epithelial cell lines NP69, NPC tissues and cell lines. EIF4G1 protein expression in NPC tissues was examined using immunohistochemistry. Survival analysis was performed using Kaplan-Meier method. The effect of EIF4G1 on cell invasion and tumorigenesis were investigated.Results: The expression levels of EIF4G1 mRNA were significantly greater in NPC tissues and cell lines than those in the normal nasopharyngeal tissues and NP69 cells (P < 0.001). Immunohistochemical analysis revealed that the expression of EIF4G1 protein was higher in NPC tissues than that in the nasopharyngeal tissues (P < 0.001). In addition, the levels of EIF4G1 protein in tumors were positively correlated with tumor T classification (P = 0.039), lymph node involvement (N classification, P = 0.008), and the clinical stages (P = 0.003) of NPC patients. Patients with higher EIF4G1 expression had shorter overall survival time (P = 0.019). Multivariate analysis showed that EIF4G1 expression was an independent prognostic indicator for the overall survival of NPC patients. Using shRNA to knock down the expression of EIF4G1 not only markedly inhibited cell cycle progression, proliferation, migration, invasion, and colony formation, but also dramatically suppressed in vivo xenograft tumor growth.Conclusion: Our data suggest that EIF4G1 can serve as a biomarker for the prognosis of NPC patients. © 2010 Tu et al; licensee BioMed Central Ltd. Source

Shan P.-F.,Zhejiang University | Shan P.-F.,Central South University | Lu Y.,Peoples Hospital of Zhongshan City | Lu Y.,Central South University | And 4 more authors.

Vascular calcification, which results from a process osteoblastic differentiation of vascular smooth muscle cells (VSMCs), is a major risk factor for cardiovascular morbidity and mortality. Apelin is a recently discovered peptide that is the endogenous ligand for the orphan G-protein-coupled receptor, APJ. Several studies have identified the protective effects of apelin on the cardiovascular system. However, the effects and mechanisms of apelin on the osteoblastic differentiation of VSMCs have not been elucidated. Using a culture of calcifying vascular smooth muscle cells (CVMSCs) as a model for the study of vascular calcification, the relationship between apelin and the osteoblastic differentiation of VSMCs and the signal pathway involved were investigated. Alkaline phosphatase (ALP) activity and osteocalcin secretion were examined in CVSMCs. The involved signal pathway was studied using the extracellular signal-regulated kinase (ERK) inhibitor, PD98059, the phosphatidylinositol 3-kinase (PI3-K) inhibitor, LY294002, and APJ siRNA. The results showed that apelin inhibited ALP activity, osteocalcin secretion, and the formation of mineralized nodules. APJ protein was detected in CVSMCs, and apelin activated ERK and AKT (a downstream effector of PI3-K). Suppression of APJ with siRNA abolished the apelin-induced activation of ERK and Akt. Furthermore, inhibition of APJ expression, and the activation of ERK or PI3-K, reversed the effects of apelin on ALP activity. These results showed that apelin inhibited the osteoblastic differentiation of CVSMCs through the APJ/ERK and APJ/PI3-K/AKT signaling pathway. Apelin appears to play a protective role against arterial calcification. © 2011 Shan et al. Source

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