Si Shi

Long non-coding RNA ROR promotes proliferation, migration and chemoresistance of nasopharyngeal carcinoma.

Nasopharyngeal carcinoma (NPC) is one of the most common malignancies of the head and neck. It arises from the nasopharynx epithelium and is associated with high morbidity and mortality. Long non‐coding RNA (lncRNA) have been reported to regulate gene interaction and play critical roles in carcinogenesis and progression. LncRNA‐ROR, a recently identified lncRNA, has been shown to be involved in initiation, progression and metastasis of several tumors, including hepatocellular carcinoma, breast cancer and glioma. However, whether lncRNA‐ROR is associated with the progression of NPC remains unknown. Resistance to radiotherapy and chemotherapy is the primary cause of NPC patients’ death. In this study, we found that lncRNA‐ROR was significantly upregulated in NPC tissues compared with normal tissues. Next, our study proved that lncRNA‐ROR was highly associated with the proliferation, metastasis and apoptosis of NPC. The enrichment of lncRNA‐ROR played a critucal functional role in chemoresistance. The mechanism by which NPC resists chemotherapy might be that lncRNA‐ROR suppress p53 signal pathway. Taken together, these data suggested that lncRNA‐ROR played an important role in the progression of NPC; thereby it might become a therapeutic target and reduce chemoresistance for NPC.

Matrix metalloproteinase 13-containing exosomes promote nasopharyngeal carcinoma metastasis.

Nasopharyngeal cancer (NPC) is an endemic type of head and neck cancer with a high rate of cervical lymph node metastasis. Metastasis is the major cause of death in NPC patients. Increasing evidence indicates that exosomes play a pivotal role in promoting cancer metastasis by enhancing angiogenesis and ECM degradation. Matrix metalloproteinase 13 is an important kind of matrix proteinase that is often overexpressed in various tumors and increases the risk of metastasis. However, little is known about the potential role of MMP13‐containing exosomes in NPC. In this study, we found that MMP13 was overexpressed in NPC cells and exosomes purified from conditioned medium (CM) as well as NPC patients’ plasma. Transwell analysis revealed that MMP13‐containing exosomes facilitated the metastasis of NPC cells. Furthermore, siRNA inhibited the effect of MMP13‐containing exosomes on tumor cells metastasis as well as angiogenesis. The current findings provided novel insight into the vital role of MMP13‐containing exosomes in NPC progression which might offer unique insights for potential therapeutic strategies for NPC progressions.

Effects of ADAM10 upregulation on progression, migration, and prognosis of nasopharyngeal carcinoma

A disintegrin and metalloprotease 10 (ADAM10) is a typical member of the ADAMs family, which has been reported to be upregulated in various types of cancers and contribute to cancer progression and metastasis. However, little is known about the role of ADAM10 in nasopharyngeal carcinoma (NPC). The purpose of this study is to explore ADAM10 expression status and its biological functions in NPC. We first examined the expression of ADAM10 in NPC tissues and cell lines by immunohistochemistry, Western blotting, PCR, and immunofluorescence analysis. We observed that ADAM10 was significantly elevated in NPC and its expression level was correlated with T classification (P = 0.044), distant metastasis (P = 0.016), TNM clinical stage (P = 0.013), and proliferation marker Ki‐67 expression (P = 0.001). Patients with NPC with high expression of ADAM10 had shorter overall survival rates. In addition, knockdown of ADAM10 by RNAi was found to inhibit the CNE‐2 cell proliferation and migration. Our findings hinted that overexpression of ADAM10 promotes the progression and migration of NPC, which makes it a potential therapeutic target for the treatment of tumor metastases in NPC.

Clinical and biological significance of HAX-1 overexpression in nasopharyngeal carcinoma

HS1-associated protein X-1 (HAX-1) is an important marker in many types of cancers and contributes to cancer progression and metastasis. We examined the expression of HAX-1 in nasopharyngeal carcinoma (NPC) and experimentally manipulated its expression. We observed that HAX-1 expression is elevated in NPC and is correlated with lymph node metastasis, M classification, clinical stage, and poor prognosis. In addition, overexpression of HAX-1 promoted NPC proliferation both in vitro and in vivo. Exosomes are potential carriers of pro-tumorigenic factors that participate in oncogenesis. We found that NPC-derived exosomes are enriched in HAX-1 and accelerate NPC tumor growth and angiogenesis in vitro and in vivo. Furthermore, we demonstrated that oncogenic HAX-1 facilitates the growth of NPC when it is transferred via exosomes to recipient human umbilical vein endothelial cells (HUVECs). Oncogenic HAX-1 also increases the proliferation, migration, and angiogenic activity of HUVECs. Our findings provide unique insight into the pathogenesis of NPC and underscore the need to explore novel therapeutic targets such as HAX-1 to improve NPC treatment.

MicroRNA-338 inhibits migration and proliferation by targeting hypoxia-induced factor 1α in nasopharyngeal carcinoma

Nasopharyngeal cancer (NPC) is an endemic type of head and neck cancer with a high rate of cervical lymph node metastasis. An increasing number of studies have shown that microRNAs (miRNAs) play a key role in the development and progression of NPC. miR-338-3p has been demonstrated as an anti-oncogene in different solid tumors. The aim of the present study was to investigate the potential role of miR‑338-3p in the development and progression of NPC. Compared with normal samples, our data showed that miR-338-3p were downregulated in NPC tissues and cells. The luciferase assay demonstrated that HIF-1α was a direct target of miR-338-3p. We also found that miR-338-3p regulated the expression levels of HIF-1α, respectively. Overexpression of miR-338-3p in NPC cells significantly inhibited cell proliferation, and migration. Conversely, miR-338-3p knockdown in cells with lower endogenous expression levels significantly reduced antitumor behavior. Furthermore, enforced expression of miR-338-3p led to a decline in ERK phosphorylation as well as inhibited the hypoxia induced epithelial to mesenchymal transition. Cells pre-transfected with miR-338-3p can overcome hypoxia-mediated cisplatin resistance. Taken together, we found that miR-338-3p directly targeted HIF-1α, and we provide insight into NPC initiation and progression, possibly representing a novel therapeutic target.

Clinical significance of HAX-1 expression in laryngeal carcinoma.

OBJECTIVE HS1-associated protein X-1 (HAX-1) is a multifunctional protein that has been highlighted as an important marker in many types of cancers. However, little is known about the role of HAX-1 in laryngeal carcinoma. The purpose of the present study is to explore HAX-1 expression status and its associations with clinicopathologic features and survival in a well-defined cohort of laryngeal carcinoma. METHODS We examined the expression of HAX-1 at protein and mRNA levels in laryngeal carcinoma tissues and adjacent non-tumor tissues by immunohistochemistry, Western blotting and two-step quantitative real-time PCR analysis, respectively. RESULTS We observed that HAX-1 was significantly elevated in laryngeal carcinoma. The relationship between the levels of HAX-1 expression and clinicopathologic characteristics was then analyzed. Overexpression of HAX-1 was significantly correlated with T classification, lymph node metastasis, clinical stage, and pathology. Survival curves were plotted using the Kaplan-Meier method and compared using the log-rank test. We find that patients with overexpression of HAX-1 had shorter overall survival rates. Finally, the significance of various survival variables was analyzed using multivariate Cox proportional hazards model. We found that overexpression of HAX-1 was an independent prognostic factor for patients with laryngeal carcinoma. CONCLUSION Our findings hinted that overexpression of HAX-1 was a potentially unfavorable factor in the progression and prognosis of laryngeal carcinoma.

High Expression of FGFR4 Enhances Tumor Growth and Metastasis in Nasopharyngeal Carcinoma

Background: FGF receptor (FGFR) family can be activated by FGFs and play important roles in regulating cell growth, differentiation, migration and angiogenesis. Recent studies suggested that FGFR4 could regulate several processes including tumor progression. Nasopharyngeal carcinoma (NPC) is a malignancy with a high occurrence in Southeast Asia and Southern China. However, the molecule mechanism and the potential roles of FGFR4 in NPC remain unknown Methods: Immunohistochemistry and western blot were used to investigate the expression of FGFR4 in NPC samples. Then we used statistical analysis to evaluate the diagnostic value and the associations of FGFR4 expression with clinical parameters. In vitro studies, the effects of FGFR4 on proliferation and migration of NPC cell line CNE2 were measured by the starvation-refeeding experiment, CCK8 assay, wounding healing assay and transwell migration assay. The changes of the epithelial-mesenchymal transition (EMT) markers in CNE2 cells after knocking down the expression of FGFR4 were measured by Western blot and immunofluorescence analysis. Results: FGFR4 was overexpressed in NPC as compared with the inflammatory tissues. High expression of FGFR4 was correlated with Ki67 expression, clinical stages and prognosis in NPC patients (P<0.05).While in vitro, the upregulation of FGFR4 was accompanied with CNE2 cells released from serum starvation. Moreover, it could increase cell proliferation and migration by regulating EMT markers in CNE2 cells. Conclusion: Our data suggested that FGFR4 might induce NPC progression and act as a potential therapeutic target in NPC.

Upregulated Expression of SOX4 Is Associated with Tumor Growth and Metastasis in Nasopharyngeal Carcinoma

SOX4, which belongs to the sex-determining region Y-related high-mobility group (SRY) box family, plays a critical role in embryonic development, cell fate decision, differentiation, and tumor development. Nasopharyngeal carcinoma (NPC) is one of the most common cancers in China and Southeast Asia. However, the molecular mechanisms of this disease remain unknown. In the present study, we used immunohistochemistry to investigate the correlation between the expression of SOX4 with clinicopathologic variables as well as patients prognosis of NPC. We found overexpression of SOX4 was correlated with clinical stages, lymph node metastasis, and Ki-67 expression in NPC (P < 0.05). Besides, patients who expressed higher levels of SOX4 had poorer survival rate (P < 0.05). Then, in vitro studies, we took serum starvation-refeeding experiment and knocked down the expression of SOX4 with siRNA to demonstrate that SOX4 could promote proliferation of NPC nonkeratinizing cell line CNE2. The regulation of SOX4 on cell migration was determined by the transwell migration assay and wounding healing assay. Besides, we also found SOX4 could promote epithelial-mesenchymal transition (EMT) of CNE2 cells and decrease their cisplatin sensitivity. Our data suggested that SOX4 might play an important role in regulating NPC progression and would provide a potential therapeutic strategy for NPC.

Metastasis-associated miR-23a from nasopharyngeal carcinoma-derived exosomes mediates angiogenesis by repressing a novel target gene TSGA10

Benefiting from more precise imaging and radiotherapy, patients with locoregionally nasopharyngeal carcinoma (NPC) have a significantly higher survival rate. Nonetheless, distant metastasis is still the predominant mode of failure. Advances in cancer research have highlighted that pathological angiogenesis is necessary for tumor metastasis by offering oxygen, nutrients, or cell metastatic conduits. MicroRNAs (miRNAs), a class of small noncoding RNAs, are increasingly implicated in modulation of angiogenesis in physiological and pathological conditions. Currently, we detected that miR-23a was highly enriched in NPC tissues at the metastatic or premetastatic stage, and its levels in NPC were associated with microvessel density. Subsequently, we proved that alteration of miR-23a expression modulated the growth, migration, and tube formation of HUVECs in vitro and affected the blood vessel outgrowth in the zebrafish model. Considering the possibility that extracellular miR-23a was horizontally transferred from CNE2 cells to HUVECs, we analyzed miR-23a encapsulated in exosomes, showing that overexpression of exosomal miR-23a in NPC promoted angiogenesis both in vitro and in vivo. Moreover, we provided evidences that miR-23a regulated angiogenesis by directly targeting testis-specific gene antigen (TSGA10). Taken together, our findings revealed that metastasis-associated miR-23a from NPC-derived exosomes plays an important role in mediating angiogenesis by targeting TSGA10.

Hypoxia-Induced Matrix Metalloproteinase-13 Expression in Exosomes from Nasopharyngeal Carcinoma Enhances Metastases

Exosomes are nano-vesicles secreted by tumor cells. Exosomes can transfer complex biological information and induce a diverse signaling response in a wide array of pathological conditions, such as hypoxia. Hypoxia is associated with aggressive phenotypes and poor outcomes in nasopharyngeal carcinoma (NPC) patients. Here, we analyzed the role of exosomes from hypoxic NPC cells in enhancing the metastases of normoxic cells in a hypoxia-induced factor-1α (HIF-1α)-dependent manner. HIF-1α rapidly accumulates and trans-activates hundreds of genes, such as matrix metalloproteinases (MMPs). We found that MMP-13 was over-expressed in exosomes and cells under hypoxic conditions. HIF-1α depletion in hypoxic CNE2 cells led to decreased MMP-13 levels in exosomes and significantly reduced cell migration and invasion. Moreover, exosomal MMP-13 significantly up-regulated Vimentin expression while decreasing E-cadherin levels in CNE2 cells in vitro and in vivo. Furthermore, MMP-13 levels were closely associated with HIF-1α expression (r = 0.679, P < 0.001), lymph node metastasis, clinical stage (all P < 0.05) and poor prognosis in NPC patients (P < 0.01). In conclusion, our findings suggest that the hypoxic exosomes were loaded with MMP-13, which could enhance migration and invasiveness and induce microenvironment changes to promote NPC aggressiveness.