High Expression of LINC01420 indicates an unfavorable prognosis and modulates cell migration and invasion in nasopharyngeal carcinoma.
ABSTRACT: Recent studies demonstrated that long non-coding RNAs (lncRNAs) deregulated in many cancer tissues including nasopharyngeal carcinoma (NPC) and had critical roles in cancer progression and metastasis. In this study, we aimed to assess a lncRNA LINC01420 expression in NPC and explore its role in NPC pathogenesis. Our research revealed that the expression level of LINC01420 in NPC tissues were higher than nasopharyngeal epithelial (NPE) tissues. Moreover, NPC patients with high LINC01420 expression level showed poor overall survival. Knockdown LINC01420 inhibited NPC cell migration and invasion in vitro. In summary, LINC01420 may play a critical role in NPC progression and may serve as a potential prognostic biomarker in NPC patients.
Project description:Chemotherapy is a crucial adjuvant therapy of advanced nasopharyngeal carcinoma (NPC). However, enhancing sensitivity and tolerance of chemotherapeutics in NPC treatment have been challenging. Both Bcl-2 and Mcl-1, 2 pro-survival proteins of Bcl-2 family, play essential roles on the chemotherapy tolerance of numerous cancers. In the present study, we explored the influences of TW-37, a small molecule inhibitor of Bcl-2 and Mcl-1, on the efficiency of chemotherapy for NPC. Oncomine cancer database shows that NPC tissues have higher expression of Bcl-2 and Mcl-1 than those of normal nasopharyngeal epithelial (NPE) tissues. And our results reveal that chemotherapeutics, Cisplatin (CDDP) and 5-Fluoracil (5-FU), result in the greater decrease of protein level of Bcl-2 and Mcl-1 in NPC cells than those in NPE cells. TW-37 does not have significant impact on the chemotherapeutics-treated NPE cell viability at a dosage that efficiently reduces chemotherapeutics-treated NPC cell viability. Moreover, impacts of TW-37 on the cell viability of chemotherapeutics-treated NPC cells are dependent on the expression of Bcl-2 and Mcl-1 in NPC cells. Further explorations suggest that TW-37 prominently promotes apoptosis in NPC cells under chemotherapeutics treatments but not in NPE cells. Meanwhile, TW-37 also remarkably reduces colony formation ability of chemotherapeutics-treated NPC cells. Importantly, in vivo models, TW-37 observably increases chemosensitivity of NPC tumors but has not markedly influence on the normal tissues in mice. In conclusion, our results point to TW-37 as a promising ancillary drug for the chemotherapy of NPC.
Project description:BACKGROUND:Recently we identified nasopharyngeal epithelium specific protein 1 (NESG1) as a potential tumor suppressor in nasopharyngeal carcinoma (NPC). The purpose of this study is to investigate the involvement of NESG1 in tumor progression and prognosis of human NPC. METHODOLOGY/PRINCIPAL FINDINGS:NESG1 protein expression in NPC was examined. Survival analysis was performed using Kaplan-Meier method. The effect of NESG1 on cell proliferation, migration, and invasion were also investigated. RESULTS:NESG1 expression was downregulated in atypical hyperplasia and NPC samples compared to normal and squamous nasopharynx tissues. Reduced protein expression was negatively associated with the status of NPC progression. Patients with lower NESG1 expression had a shorter overall survival and disease-free time than did patients with higher NESG1 expression. Multivariate analysis suggested NESG1 expression as an independent prognostic indicator for NPC patient survival. Proliferation, migration, and invasion ability were significantly increased in cell lines following lentiviral-mediated shRNA suppression of NESG1 expression. Microarray analysis indicated that NESG1 participated in multiple pathways, including MAPK signaling and cell cycle regulation. Finally, DNA methylation microarray examination revealed a lack of hypermethylation at the NESG1 promoter, suggesting other mechanisms are involved in suppressing NESG1 expression in NPC. CONCLUSION:Our studies are the first to demonstrate that decreased NESG1 expression is an unfavorable prognostic factor for NPC.
Project description:Nasopharyngeal carcinoma (NPC) is a highly metastatic cancer that is consistently associated with Epstein-Barr virus (EBV) infection. In this study, we identify for the first time a role for monoamine oxidase A (MAOA) in NPC. MAOA is a mitochondrial enzyme that catalyzes oxidative deamination of neurotransmitters and dietary amines. Depending on the cancer type, MAOA can either have a tumour-promoting or tumour-suppressive role. We show that MAOA is down-regulated in primary NPC tissues and its down-regulation enhances the migration of NPC cells. In addition, we found that EBV infection can down-regulate MAOA expression in both pre-malignant and malignant nasopharyngeal epithelial (NPE) cells. We further demonstrate that MAOA is down-regulated as a result of IL-6/IL-6R/STAT3 signalling and epigenetic mechanisms, effects that might be attributed to EBV infection in NPE cells. Taken together, our data point to a central role for EBV in mediating the tumour suppressive effects of MAOA and that loss of MAOA could be an important step in the pathogenesis of NPC.
Project description:Undifferentiated nasopharyngeal carcinomas (NPCs) are commonly present with latent EBV infection. However, events regulating EBV infection at early stages of the disease and the role of EBV in disease pathogenesis are largely undefined. Genetic alterations leading to activation of cyclin D1 signaling in premalignant nasopharyngeal epithelial (NPE) cells have been postulated to predispose cells to EBV infection. We previously reported that loss of p16, a negative regulator of cyclin D1 signaling, is a frequent feature of NPC tumors. Here, we report that early premalignant lesions of nasopharyngeal epithelium overexpress cyclin D1. Furthermore, overexpression of cyclin D1 is closely associated with EBV infection. Therefore we investigated the potential role of cyclin D1 overexpression in dysplastic NPE cells in vitro. In human telomerase reverse transcriptase-immortalized NPE cells, overexpression of cyclin D1 or a p16-resistant form of CDK4 (CDK4(R24C)) suppressed differentiation. This suppression may have implications for the close association of EBV infection with undifferentiated NPC. In these in vitro models, we found that cellular growth arrest and senescence occurred in EBV-infected cell populations immediately after infection. Nevertheless, overexpression of cyclin D1 or a p16-resistant form of CDK4 or knockdown of p16 in the human telomerase reverse transcriptase-immortalized NPE cell lines could counteract the EBV-induced growth arrest and senescence. We conclude that dysregulated expression of cyclin D1 in NPE cells may contribute to NPC pathogenesis by enabling persistent infection of EBV.
Project description:Nasopharyngeal carcinoma (NPC) is a highly invasive and metastasis-prone epithelial cancer. The paucity of effective treatment strategies for recurrent and metastatic NPC is the major cause for stagnating survival rate of NPC. Therefore, it's urgent to understand the molecular mechanisms underlying NPC progression and identify novel avenues for targeted therapy. It has emerged recently that microRNAs are potential pro-tumorigenic or tumor-suppressive factors that participate in oncogenesis. In this study, we found that miR-744 expression was upregulated in NPC specimens compared to nasopharyngeal epithelium (NPE) tissue, and miR- 744 upregulation was significantly associated with TNM stage, tumorigenesis and metastasis. Functional studies revealed that miR-744 acts as a novel tumor promotor in NPC. Moreover, we determined that miR-744 targets ARHGAP5 (Rho GTPase activating protein 5), a protumorigenic gene, by directly interacting with its promoter and thereby regulating its expression at transcriptional level. Reintroduction of ARHGAP5 resembled the effects of miR-744 and silencing of ARHGAP5 clearly abrogated miR-744-induced enhancement of cell migration and invasion. High level of ARHGAP5 was positively correlated with that of miR-744 and with advanced stages of NPC, as well as with lymph node metastasis. Taken together, these data reveal for the first time that miR-744 exerts its proto-oncogenic function by directly targeting ARHGAP5 promoter. This newly identified miR-744/ARHGAP5 pathway provides further insight into the progression and metastasis of NPC and indicates potential novel therapeutic targets for NPC.
Project description:Nasopharyngeal carcinoma (NPC) progression is regulated by genetic, epigenetic, and epitranscript modulation. As one of the epitranscript modifications, the role of N6-Methyladenosine (m6A) has not been elucidated in NPC. In the present study, we found that the poorly methylated gene ZNF750 (encoding zinc finger protein 750) was downregulated in NPC tumor tissues and cell lines. Ectopic expression of ZNF750 blocked NPC growth in vitro and in vivo. Further studies revealed that m6A modifications maintained the low expression level of ZNF750 in NPC. Chromatin immunoprecipitation sequencing identified that ZNF750 directly regulated FGF14 (encoding fibroblast growth factor 14), ablation of which reversed ZNF750's tumor repressor effect. Moreover, the ZNF750-FGF14 signaling axis inhibited NPC growth by promoting cell apoptosis. These findings uncovered the critical role of m6A in NPC, and stressed the regulatory function of the ZNF750-FGF14 signaling axis in modulating NPC progression, which provides theoretical guidance for the clinical treatment of NPC.
Project description:Background:Epstein-Barr virus-encoded LMP1 plays a critical role in the carcinogenesis of nasopharyngeal carcinoma (NPC), but the mechanism remains elusive. We aimed to analyze the expression and clinical pathological significance of provirus integration site for Moloney murine leukemia virus 1 (Pim1) in clinical NPC, and to elucidate the effect of LMP1 on Pim1 expression and its mechanism. Methods:Immunohistochemical staining was used to detect the expression of Pim1 in clinical NPC tissues and control nasopharyngeal chronic inflammation (NPI) tissues, and the correlation between Pim1 and clinical parameters of NPC patients was analyzed. The LMP1 stable expression cell line CNE1-LMP1-OV was constructed through infecting the well-differentiated nasopharyngeal carcinoma cells CNE1 with LMP1 overexpressing lentivirus. Then the in vivo experiments were conducted. Results:Among 89 NPC patients, 48 cases (53.93%) were positive for Pim1, while only one case was Pim1 positive in 15 NPI controls (6.67%). Pim1 expression was not correlated with gender, age, smoking status and clinical classification of NPC patients, but positively correlated with T, N and M classification. CNE1-LMP1-OV cell line was successfully established, which displayed a higher cell proliferation ability and Pim1 expression. NF-?B inhibitor PDTC, PKC inhibitor GF109203X and STAT3 inhibitor Stattic significantly attenuated LMP1-induced Pim1 expression, and while AP-1 inhibitor SR11302 showed no inhibitory effect. Interestingly, Pim1 inhibitor quercetagetin significantly inhibited the proliferation of CNE1-LMP1-OV cells. Conclusion:LMP1 mediates Pim1 expression through NF-?B, PKC and STAT3 signaling, which promotes the proliferation of NPC cells and participate in the clinical progression of NPC.
Project description:BACKGROUND:The role of CTGF varies in different types of cancer. The purpose of this study is to investigate the involvement of CTGF in tumor progression and prognosis of human nasopharyngeal carcinoma (NPC). EXPERIMENTAL DESIGN:CTGF expression levels were examined in NPC tissues and cells, nasopharynx (NP) tissues, and NP69 cells. The effects and molecular mechanisms of CTGF expression on cell proliferation, migration, invasion, and cell cycle were also explored. RESULTS:NPC cells exhibited decreased mRNA expression of CTGF compared to immortalized human nasopharyngeal epithelial cell line NP69. Similarly, CTGF was observed to be downregulated in NPC compared to normal tissues at mRNA and protein levels. Furthermore, reduced CTGF was negatively associated with the progression of NPC. Knocking down CTGF expression enhanced the colony formation, cell migration, invasion, and G1/S cell cycle transition. Mechanistic analysis revealed that CTGF suppression activated FAK/PI3K/AKT and its downstream signals regulating the cell cycle, epithelial-mesenchymal transition (EMT) and MMPs. Finally, DNA methylation microarray revealed a lack of hypermethylation at the CTGF promoter, suggesting other mechanisms are associated with suppression of CTGF in NPC. CONCLUSION:Our study demonstrates that reduced expression of CTGF promoted cell proliferation, migration, invasion and cell cycle progression through FAK/PI3K/AKT, EMT and MMP pathways in NPC.
Project description:URG4, a novel oncogene, is involved in the development and progression of various tumors. This study investigated the clinicopathological significance of URG4 in nasopharyngeal carcinoma (NPC). We used five NPC tissues and adjacent normal nasopharyngeal tissues to determine URG4 expression and found that URG4 was upregulated in NPC tissues. Immunohistochemistry analysis found URG4 was expressed positively in 97.1% (99/102) of NPC samples and highly expressed in 41.2% (42/102) of NPC samples. Its level was positively correlated with advancing clinical stage. Kaplan-Meier analysis with the log-rank test found that patients with high URG4 expression had poor outcome and patients with low URG4 expression had better survival. Statistical analysis showed that there was a significant correlation between URG4 expression and clinical stage, larger tumor size, and lymph node involvement. Cox-regression analysis showed that URG4 expression could serve as a prognostic factor for NPC patients. In summary, this study showed that URG4 was upregulated in NPC tissues, patients with high URG4 expression had poor outcome, and URG4 was found to be a valuable biomarker for NPC progression.
Project description:The role of long non-coding RNA (lncRNA) in the progression of Nasopharyngeal carcinoma (NPC) has not been fully elucidated. The study was designed to explore the functional role of NKILA, a newly identified lncRNA, in the progression of NPC. We performed a lncRNA expression profile microarray using four NPC and paired para-cancerous tissues. NKILA was identified as a potential functional lncRNA by this lncRNA expression profile. We used 107 paraffin-embedded NPC tissues with different TNM stages to detect the expression of NKILA and analyzed the survival data by Log-rank test and Cox regression. The role of NKILA and its underlying mechanisms in the progression of NPC were evaluated by a series of experiments in vitro and vivo by silencing or expressing NKILA. Compared with control tissues, NKILA expression was identified to be decreased in NPC tissues. Low NKILA expression was correlated with unfavorable clinicopathological features and predicted poor survival outcome in NPC patients. After adjusting for potential confounders, low expression of NKILA was confirmed to be an independent prognostic factor correlated with poor survival outcomes. Furthermore, we found that NKILA overexpression in high-metastatic-potential NPC cells repressed motile behavior and impaired the metastatic capacity in vitro and in vivo. In contrast, RNAi-mediated NKILA depletion increased the invasive motility of cells with lower metastatic potential. Further experiments demonstrated that NKILA regulated the metastasis of NPC through the NF-?B pathway. Taken together, NKILA plays vital roles in the pathogenesis of NPC. The unique histological characteristics of NPC indicate that local inflammation plays a vital role in carcinogenesis of nasopharyngeal carcinoma.