CNE2 Cells Research Articles

Prodigiosin Inhibits Proliferation, Migration, and Invasion of Nasopharyngeal Cancer Cells

Background/Aims: Nasopharyngeal carcinoma remains a devastating and difficult disease to treat. This study explores the antineoplastic effect of prodigiosin on nasopharyngeal cancer cells. Methods: Human nasopharyngeal carcinoma CNE2 cells and human normal nasopharyngeal epithelial NP69 cells were obtained and treated with prodigiosin or fluorouracil (5-FU). Colony formation assay was performed to screen for the optimal experimental concentrations of prodigiosin and 5-FU, and MTT assay was used to examine cell proliferative ability. Flow cytometry was used to examine cell cycle distribution, the scratch test was employed to examine cell migration, and Transwell migration assay (Boyden chamber) was used to study cell invasion. Results: The optimal concentrations of prodigiosin and 5-FU for treatment were 4 mg/L and 0.35 mg/L, respectively. Both prodigiosin and 5-FU inhibited tumor cell proliferation. The percentage of cells in G0/G1 phase was higher and the percentage of cells in S phase was lower in the prodigiosin and 5-FU groups than in the untreated groups. Both prodigiosin and 5-FU inhibited tumor cell migration and tumor cell invasion. Conclusions: Our results suggest that prodigiosin can inhibit proliferation, migration, and invasion of nasopharyngeal carcinoma cells.

壳聚糖基聚合物碳点荧光材料合成及其自组装载药应用

Fluorescent carbon dots have the advantages of good chemical stability, low toxicity, and surface functionalization, which has caused concern. In recent years, polymer carbon dots synthesize by polymer polysaccharides have become a new research hotspot. In this paper, a chitosan-based fluorescent polymer carbon dot material is synthesized by hydrothermal method and used for drug-loading research. We choose chitosan-graft-polyethylene glycol monomethyl ether and citric acid derivatives as the carbon sources for the carbon dots, because chitosan and polyethylene glycol are both a carbon source for carbon dots and a passivation reagent for carbon dots. Then the quantum yield of the polymeric carbon dots is increased. Polymer carbon dots can also retain the molecular structure of polyethylene glycol and chitosan, providing favorable conditions for its application in drug loading. The structural characterization is performed on P(CS-g-mPEG-CA)CDs by IR, UV, X-ray diffraction, photoelectron spectroscopy, transmission electron microscopy and photoluminescence spectra and pH stability test is carried out. The results show that the synthesized P(CS-g-mPEG-CA)CDs has higher fluorescence quantum yield(66.81%), longer fluorescence lifetime(15.247 ns), and better pH stability. Using Doxorubicin as a model drug, a load study was conducted using this polymer carbon dot. The results show that if the degree of substitution of mPEG is 11.9%, the maximum loading rate of polymer carbon dots is 51.3% and the maximum drug release rate is 28.7%. In addition, we also found that drug loading and release could be controlled by the grafting rate of mPEG. In addition, the cytotoxicity of polymer carbon dots on nasopharyngeal carcinoma cells(CNE-2) is evaluated using an MTT assay. The study shows that there is no obvious cytotoxicity of blank P(CS-g-mPEG-CA)CDs, and that the survival rate of CNE-2 cells decreases with the increase of drug-loaded micelles. The results show that the P(CS-g-mPEG-CA)CDs have a certain application prospect in the aspects of fluorescence labeling, drug delivery, fluorescent tracer system and controlled release.

MicroRNA-19b Promotes Nasopharyngeal Carcinoma More Sensitive to Cisplatin by Suppressing KRAS.

MicroRNAs have been reported to play a vital role in diverse biological processes and tumorigenesis. MicroRNA-19b-5p has been observed to be downregulated in other cancers, but the function of microRNA-19b-5p in human nasopharyngeal carcinoma has not been well investigated. In our study, these results demonstrated that microRNA-19b-5p was significantly downregulated in 37 pairs of nasopharyngeal carcinoma tissues when compared to normal tissues. Enforced expression of microRNA-19b-5p inhibited activity of cell proliferation and cell migration of nasopharyngeal carcinoma cancer cells, CNE1 and HNE1. Furthermore, microRNA-19b-5p targeted KRAS proto-oncogene, GTPase in cancer cells. In human clinical specimens, KRAS was higher expressed in cancer tissues when compared with normal tissues, which was inversely correlated with the expression of microRNA-19b-5p. More interestingly, microRNA-19b-5p sensitizes CNE1 cells to cisplatin by inhibiting its target KRAS. Finally, microRNA-19b-5p inhibits tumorigenesis in vivo. Thus, our results investigated that microRNA-19b-5p functioned as a tumor suppressor and indicated its potential application for the treatment of human nasopharyngeal carcinoma in future.

Reduced QSOX1 enhances radioresistance in nasopharyngeal carcinoma.

Radioresistance is a major cause leads to treatment failure in nasopharyngeal carcinoma (NPC). In our previous study, we identified that QSOX1 is a differentially expressed protein in NPC cell lines with variable radiosensitivities. The present study aimed to investigate the biological behavior of QSOX1 in nasopharyngeal carcinoma (NPC) and its effect on radiosensitivity. The levels of QSOX1 detected by enzyme-linked immunosorbent assay (ELISA) and immunohistochemistry (IHC) in radioresistant NPC patient sera and tissue samples were markedly lower than those in radiosensitive samples. Small hairpin RNAs (shRNAs) were employed to knock down endogenous QSOX1 expression in CNE-2 cells, and then, radiosensitivity, apoptosis, migration and invasion were assessed using colony formation, Cell Counting Kit-8 (CCK-8), flow cytometry, and transwell assays, respectively. Tumor growth and radioresistance were also evaluated using a xenograft model in nude mice. The shRNA-mediated knockdown of QSOX1 significantly increased cell survival under irradiation (IR) and weakened radiosensitivity, which was likely due to a reduction in the cell apoptosis rate after IR. Moreover, QSOX1 silencing led to the suppression of cellular migration and invasion. Similar results were obtained with the xenograft mouse model. Thus, targeting QSOX1 will provide a new avenue for increasing the sensitivity of NPC to radiotherapy.

Role of the Akt/mTOR signaling pathway in human papillomavirus-associated nasal and sinonasal inverted papilloma.

Nasal and sinonasal inverted papilloma (NSIP) is a benign tumor in which surface epithelial cells grow downward into the underlying supportive tissue with varying degrees of metaplasia. Human papillomavirus (HPV) has been proposed as the causal agent in the pathogenesis of this disease. Many studies have shown that HPV can activate the Akt/mechanistic target of rapamycin (mTOR) signaling pathway, but the role of this pathway in HPV-associated NSIP is largely unknown. In this study, we enrolled 40 control tissue samples and 80 NSIP tissue samples. HPV genotyping showed that 47 of the 80 examined cases of NSIP were HPV-positive (58.8%), and the most common subtype was HPV11 (20/53, 37.7%). The immunohistochemistry showed statistically significant differences in phosphorylated Akt and phosphorylated S6 ribosomal protein staining among control samples, HPV-positive NSIP and HPV-negative NSIP. The HPV11 L1-L2 plasmid increased the proliferation of normal human nasopharyngeal epithelial NP69-SV40T cells and human nasopharyngeal cancer CNE1 cells. Meanwhile, rapamycin, an mTOR inhibitor, reversed the increased cell proliferation induced by the HPV11 L1-L2 plasmid. Western blot analysis showed that Akt/mTOR/S6 were overexpressed in NP69-SV40T cells and CNE1 cells infected with the HPV11 L1-L2 plasmid. These data demonstrate that HPV promotes cell proliferation through the Akt/mTOR signaling pathway in NSIP.

(-)-Epigallocatechin‑3‑gallate inhibition of Epstein‑Barr virus spontaneous lytic infection involves downregulation of latent membrane protein 1

The Epstein-Barr virus (EBV) lytic cycle contributes to the development of EBV-associated diseases. EBV-encoded latent membrane protein 1 (LMP1) is key to EBV lytic replication, and our previous work indicated that epigallocatechin-3-gallate (EGCG) inhibited constitutive EBV lytic infection through the suppression of LMP1-activated phosphoinositide 3-kinase/Akt and mitogen-activated protein kinase kinase/extracellular signal-related protein kinase 1/2 signaling. The present study demonstrated that LMP1 in CNE-LMP1 constructed cells significantly induced the expression of the EBV lytic proteins BZLF1 (P<0.001) and BMRF1 (P<0.05) compared with CNE1 cells. Following treatment with a specific DNAzyme that targets LMP1, significantly reduced protein expression levels of BZLF1 and BMRF1 in EBV-associated epithelial carcinoma CNE1-LMP1 cells (P<0.001 and P<0.01, respectively) and lymphoma B95.8 cells (both P<0.01) were observed. Furthermore, EGCG significantly inhibited the mRNA and protein expression levels of LMP1 (P<0.05) in an apparent dose-dependent manner in CNE1-LMP1 and B95.8 cells. Thus, the present findings indicated that the molecular mechanism underlying EGCG inhibition of EBV lytic infection involves downregulation of LMP1.

Sers Imaging of Nasopharyngeal Carcinoma Markers Using an Antibody-Conjugated Gold Nanoparticles Probe

Surface-enhanced Raman scattering (SERS) nanotags as an ultrasensitive nanoprobe is becoming popular for the detection of biomarkers. Herein, antibody-conjugated gold nanoparticles (AuNPs) were used to target LMP2A in an LMP2A-infected CNE2 cell line. SERS maps showed that the LMP2A was distributed around the cell, which was consistent with the results of immunofl uorescence staining in the previous report. This location could be due to the specific binding of the bioconjugated nanotags to the receptors on the cell surface. However, the CNE2 cell line without LMP2A-infected showed no detectable signal at 1044 cm–1. The results demonstrated the potential feasibility of AuNPs nanotags as highly sensitive probes conjugated at the subcellular level for detection and localization of cancer markers in nasopharyngeal carcinoma (NPC).

Low concentration of formononetin promotes proliferation of estrogen receptor-positive cells through an ERα-miR-375-PTEN-ERK1/2-bcl-2 pathway.

A low dose of formononetin accelerates the proliferation of nasopharyngeal carcinoma cells in vitro; however, the underlying mechanism remains unknown. Here, we investigated the molecular mechanism of formononetin in CNE2 cell proliferation. CNE2 cells were treated with 0 to 1 μM formononetin. To inhibit mitogen activated protein kinase / extracellular regulate kinase (MAPK/ERK) kinase (MEK) and microRNA (miR)-375, cells were pretreated with either PD98059 or a miR-375 inhibitor, respectively, followed by co-treatment with formononetin (0.3 μM) plus an inhibitor. Female rats were ovariectomized (OVX), and some OVX rats received formononetin or estrogen (E2) injections. Sham operated animals were used as controls. Compared to control, 0.3 μM formononetin accelerated proliferation and decreased late apoptosis of CNE2 cells. However, formononetin-induced pro-growth and anti-apoptosis activity was abolished by PD98059 and the miR-375 inhibitor. In addition, 0.1 and 0.3 μM formononetin significantly increased estrogen receptor-α (ERα) and bcl-2, but decreased protein-phosphatase and tensin homologue (PTEN) protein expression, all of which was reversed by the miR-375 inhibitor. Additionally, formononetin treatment resulted in a transient upregulation of phosphorylated (p)-ERK1/2. In vivo studies indicated that formononetin significantly increased endometrium thickness and down-regulated ERα expression in OVX rats. Taken together, our study demonstrates that a low concentration of formononetin can promote growth of CNE2 cells and uterine tissues, possibly through regulating the ERα-miR-375-PTEN-ERK1/2-bcl-2 signaling pathway.

Study of miR-10b regulatory mechanism for epithelial-mesenchymal transition, invasion and migration in nasopharyngeal carcinoma cells.

The aim of the study was to investigate the miR-10b regulatory mechanism for epithelial-mesenchymal transition (EMT) and its effect on the proliferation and migration of nasopharyngeal carcinoma cells. RT-qPCR was used to detect the expression of miR-10b in CNE1 nasopharyngeal carcinoma cell line. The NP69 nasopharyngeal mucosal cell line was used to determine the expression of miR-10b after infection with lentivirus. The effect of miR-10b on the proliferation of NP69 was examined using cell counting kit-8. The effect of miR-10b on NP69 migration was examined using scratch assay. Western blot analysis was used to detect the effects of miR-10b on the expression of epithelial cell markers E-cadherin and β-catenin and mesenchymal cell markers fibronectin, N-cadherin, vimentin and matrix metalloproteinase-9 (MMP-9). The present study showed that miR-10b was highly expressed in CNE1 cells. The stable expression of miR-10b promoted the proliferation and migration of NP69 cells, downregulated the expression of epithelial cell markers E-cadherin and β-catenin, and upregulated the expression of mesenchymal cell markers fibronectin, N-cadherin, vimentin and MMP-9 resulting in cell EMT. In conclusion, miR-10b promotes the proliferation and migration of nasopharyngeal carcinoma cells, and induces EMT in nasopharyngeal carcinoma cells, thereby having the potential to become a new target for the treatment of nasopharyngeal carcinoma.

High YBX1 expression indicates poor prognosis and promotes cell migration and invasion in nasopharyngeal carcinoma

Y-box binding protein-1 (YBX1) is a multifunctional protein and often acts as an indicator of poor prognosis in cancers. Increasing evidence has shown that the levels of YBX1 protein were closely associated with multidrug resistance, relapse, metastasis and poor prognosis in cancers. However, its role in nasopharyngeal carcinoma (NPC) metastasis remains unknown. In our study, we discovered that the expression of YBX1 was increased in nasopharyngeal carcinoma tissues. YBX1 protein levels positively correlated with T stage and metastasis of NPC patients. Moreover, expression of YBX1 was negatively correlated with membrane E-cadherin levels and positively correlated with Vimentin expression. In vitro, the expression of YBX1 was closely related to the invasive and migratory ability of nasopharyngeal carcinoma cells. Knockdown of YBX1 inhibited migration and invasion in 5–8F cells, and over-expression of YBX1 promoted CNE1 cells migration and invasion. Transforming growth factor-β1 (TGF-β1) treatment led to epithelial-to-mesenchymal transition (EMT) in CNE1 cells accompanied by elevated YBX1 expression. On the contrary, knockdown of YBX1 partially inhibited the TGF-β1-induced CNE1 cell migration, together with changes of EMT-associated markers. Our study revealed that TGF-β1/YBX1 signaling might be one of novel mechanisms mediating EMT in NPC, providing a new target for the treatment of nasopharyngeal carcinoma.

Downregulation of lncRNA X Inactive Specific Transcript (XIST) Suppresses Cell Proliferation and Enhances Radiosensitivity by Upregulating mir-29c in Nasopharyngeal Carcinoma Cells.

BackgroundLncRNA X inactive specific transcript (XIST) was reported to function as an oncogene in nasopharyngeal carcinoma cells (NPC) by sponging miR-34a-5p. However, the role of XIST in modulating the radiosensitivity of NPC cells and its mechanism still remain undefined.Material/MethodsThe expressions of XIST and miR-29c in NPC cells were evaluated by qRT-PCR. CNE1 and CNE2 cells were transfected with si-XIST, pcDNA-XIST, miR-29c mimics, anti-miR-29c, or respective controls by Lipofectamine 2000. The effects of XIST knockdown and miR-29c overexpression on cell proliferation, survival fraction, and γ-H2AX expression were investigated by CCK-8 assay, colony formation assay, immunofluorescence, and Western blot, respectively. Luciferase reporter assay and qRT-PCR analysis were performed to confirm whether XIST interacts with miR-29c and regulates its expression.ResultsXIST was upregulated and miR-29c was downregulated in NPC cells. The expressions of XIST and miR-29c changed reversely in response to irradiation. Knockdown of XIST and miR-29c overexpression both resulted in a dramatic suppression of cell proliferation, a marked enhancement of radiosensitivity, and an obvious increase of γ-H2AX foci formation in NPC cells. Luciferase reporter assay and qRT-PCR analysis demonstrated that XIST interacts with miR-29c and negatively regulates its expression. Moreover, miR-29c inhibition abrogated XIST knockdown-induced cell proliferation inhibition and radiosensitivity increase in NPC cells.ConclusionsXIST knockdown suppressed cell proliferation and enhanced radiosensitivity of NPC cells by upregulating miR-29c, providing a novel therapeutic target to improve radiotherapy efficiency for patients with NPC.

Radio-sensitizing effect of ethyl caffeate on nasopharyngeal carcinoma CNE-2 cell line

Purpose: To investigate the radio-sensitizing effect of ethyl caffeate (ETF) on naso-pharyngeal carcinoma. Methods: MTT (3-(4, 5-dimethylthiazolyl-2)-2, 5-diphenyltetrazolium bromide) assay was used to evaluate the cell viability of CNE-2 cells, while their levels of caspase-3 and caspase-9 were determined by enzyme-linked immunosorbent assay (ELISA). In addition, a xenograft model was established in nude mice. The model was treated with ETF (40 mg/kg) and subjected to β-irradiation (10 Gy) for 28 days, during which tumor volume was determined at 4-day intervals. Expressions of caspase-3, caspase-9 and Bcl-2 were determined by western blotting assay. Results: β-irradiation (10 Gy) did not produce any obvious inhibitory effect on the proliferation of CNE-2 cells. However, ETF (10, 20 and 40 μg/mL) significantly enhanced the radiosensitivity of the cells to β- irradiation ( p < 0.01) and significantly increased their levels of caspase-3 and caspase-9 ( p < 0.01). The combination of ETF (40 mg/kg) with β-irradiation resulted in significant inhibition of tumor growth in mice xenograft model ( p < 0.01). The combined treatment also resulted in significant up-regulation of expressions of caspase-3 and casepase-9 and significant down-regulation of Bcl-2 in the tumor tissues when compared with corresponding tissues from the control mice ( p < 0.01). Conclusion: ETF significantly enhances the sensitivity of naso-pharyngeal carcinoma CNE-2 cells to β- irradiation, probably through induction of mitochondria-mediated apoptosis. ETF may be useful for treating naso-pharyngeal carcinoma in combination with radiation therapy. Keywords: Ethyl caffeate, Radio-sensitizing effects, Caspase, Nasopharyngeal carcinoma, CNE-2 cell line, β-irradiation

RNAi-mediated knockdown of CAIX enhances the radiosensitivity of nasopharyngeal carcinoma cell line, CNE-2.

Although radiotherapy remains the most powerful as well as the primary treatment modality for nasopharyngeal carcinoma (NPC), approximately 20% of NPC patients still have local recurrence. Carbonic anhydrase IX (CAIX)-related signaling pathways that mediate radioresistance have been found in various kinds of cancer. However, the role of CAIX in NPC radioresistance is still unknown. In this study, we investigated the effect of CAIX silencing on sensitization to ionizing radiation in NPC by using Lipofectamine 2000, which delivers small interfering ribonucleic acid (siRNA) that targets CAIX. Results showed that Lipofectamine 2000 effectively delivered siRNA into the CNE-2 cells, which resulted in the decrease of CAIX expression and cell viability, decrease in cell proliferation and colony formation, and increase in the number of CNE-2 cells stuck in the G2/M phase of the cell cycle upon induction of ionizing radiation. Increased sensitivity of radiotherapy in CNE-2 cells under hypoxic conditions was correlated with the suppression of CAIX. Cells treated with irradiation in addition to CAIX-siRNA1 demonstrated reduced radiobiological parameters (survival fraction at 2 Gy [SF2]) compared with those treated with irradiation only, with a sensitization-enhancing ratio of 1.47. These findings suggest that CAIX can be a promising therapeutic target for the treatment of radioresistant human NPC.

Design and synthesis of 2-phenylpyrimidine coumarin derivatives as anticancer agents

A series of 2-phenylpyrimidine coumarin derivatives with potential telomerase-inhibiting activity was designed and synthesized. All of the compounds were screened for antiproliferative activity against CNE2, KB, and Cal27 cell lines in vitro. The results showed that most of the derivatives had a favorable effect on resisting tumor cell proliferation; compound 13, 3-(4-amino-5-oxo-5H-chromeno[4,3-d]pyrimidin-2-yl)phenyl 4-(dimethylamino)benzenesulfonate, exhibited the best activity. Flow cytometry revealed that compound 13 can inhibit CNE2 proliferation. Telomerase inhibition and in vitro antitumor activity were consistent among the compounds, but compound 13 showed the best telomerase-inhibiting activity and could inhibit telomere extension. Molecular docking results indicated that compound 13 bonded with telomerase reverse transcriptase (TERT) through multiple interactions, including hydrogen bonding and hydrophobic interactions. The results of the study provide further information on 2-phenylpyrimidine coumarins, expanding the types of telomerase inhibitors as the parent structures.

Investigation of the effects induced by 1 400 W on nasopharyngeal carcinoma cell and the mechanism

Objective To investigate the effect induced by specific inducible nitric oxide synthase (iNOS) inhibitor 1 400 W on nasopharyngeal carcinoma CNE-2 cells lines and its mechanism. Methods CNE-2 cells were treated by different concentrations of 1 400 W, diamminedichloroplatinum (DDP), and both chemicals. Cell counting kit-8 (CCK-8) was used to examine the viability of cells. Quantitative real-time polymerase chain reaction (qRT-PCR) was applied to detect the iNOS mRNA expression. Results The expression of iNOS mRNA was down-regulated by 1400W and was positively correlated with inhibition rate of cell proliferation. 1 400 W inhibits proliferation of CNE-2 cell in a concentration-dependent manner. The proliferation inhibition rate of CNE-2 cells treated by 1 400 W combined with DDP was not enhanced. Conclusions Specific inducible nitric oxide synthase inhibitor 1 400 W can exerts anti-tumor effect though inhibiting the expression of iNOS mRNA; The mechanism of chemosensitization induced by iNOS inhibitor on CNE-2 cells may be closely related level of down-regulation of iNOS expression. Key words: Nitric oxide synthase/AI/ME; Nasopharyngeal neoplasms/DT/ME

Radiotherapy induces cell cycle arrest and cell apoptosis in nasopharyngeal carcinoma via the ATM and Smad pathways

ABSTRACTNasopharyngeal carcinoma (NPC) is a common malignant neoplasm of the head and neck which is harmful to human's health. Radiotherapy is commonly used in the treatment of NPC and it induces immediate cell cycle arrest and cell apoptosis. However, the mechanism remains unknown. Evidences suggested the activation of Ataxia telangiectasia mutated (ATM) pathway and Smad pathway are 2 of the important crucial mediators in the function of radiotherapy. In this study, we performed in vitro assays with human nasopharyngeal carcinoma CNE-2 cells and in vivo assays with nude mice to investigate the role of the ATM and Smad pathways in the treatment of nasopharyngeal carcinoma with radiotherapy. The results suggested that radiation induced activation of ATM pathway by inducing expression of p-ATM, p-CHK1, p-CHK2, p15 and inhibiting expression of p-Smad3. In addition, Caspase3 expression was increased while CDC25A was decreased, leading to cell cycle arrest and cell apoptosis. On the other hand, activation of Smad3 can inhibited the ATM pathway and attenuated the efficacy of radiation. In summary, we suggest that both ATM and Smad pathways contribute to the cell cycle arrest and cell apoptosis during nasopharyngeal carcinoma cells treated with radiation.

In Vivo and In Vitro Effects of ATM/ATR Signaling Pathway on Proliferation, Apoptosis, and Radiosensitivity of Nasopharyngeal Carcinoma Cells.

The study investigated the ability of ataxia-telangiectasia mutated (ATM)/Rad3-related (ATR) signaling pathway to influence the proliferation, apoptosis, and radiosensitivity of nasopharyngeal carcinoma (NPC) cells. NPC tissues and corresponding adjacent normal tissues were collected from 143 NPC patients. The NPC CNE2 cells were assigned into a control group, X-ray group, CGK-733 group, and X-ray+CGK-733 group. The mRNA levels of ATM and ATR were evaluated using quantitative real-time polymerase chain reaction (qRT-PCR) and the protein levels of ATM and ATR using western blotting. The positive expression of ATM and ATR in tissues and nude mouse tumor tissues was determined by immunohistochemistry. Cell proliferation, migration, invasion, and apoptosis rates were analyzed by the 3-(4,5)-dimethylthiahiazo (-z-y1)-3,5-di- phenytetrazoliumromide (MTT) assay, scratch test, transwell assay, and flow cytometry, respectively. A nude mouse model of NPC was established to observe tumor volume and growth. The mRNA levels of ATR and ATM and the expression of ATR and ATM protein in NPC tissues were significantly higher than those in adjacent normal tissues. The colony formation assay showed that the colony-forming rate decreased, showing radiation dose-dependent and CGK-733 concentration-dependent manners. Expression of ATM, ATR, Chk1, and Chk2 was evidently increased in the X-ray, CGK-733, and X-ray+CGK-733groups compared with the control group, and the aforementioned expression was highest in the X-ray+CGK-733 group among the four groups. The cell proliferation, invasion, and migration were decreased, tumor volume decreased and cell apoptosis increased in the X-ray, CGK-733, and X-ray+CGK-733 groups compared with the control group; the X-ray+CGK-733 group exhibited lowest cell proliferation, invasion and migration, smallest tumor volume, and highest cell apoptosis among the four groups. Inhibition of ATM/ATR signaling pathway reduces proliferation and enhances apoptosis and radiosensitivity of NPC cells.

Vimentin is a crucial target for anti-metastasis therapy of nasopharyngeal carcinoma.

Nasopharyngeal carcinoma (NPC) is a unique subtype of head and neck cancer, with tendency to spread to regional lymph nodes and distant organs at early stage. Vimentin, a major cytoskeletal protein constituent of the intermediate filament, plays a critical role in the epithelial-mesenchymal transition. Overexpression of vimentin is considered to be a critical prerequisite for metastasis in numerous human cancers. Therefore, targeting vimentin for cancer therapy has gained a lot of interest. In the present study, we detected vimentin expression in NPC tissues and found that overexpression of vimentin is associated with poor prognosis of NPC patients. Silencing of vimentin in NPC CNE2 cells by RNAi suppresses cells migration and invasion in vitro. However, blocking vimentin did not affect cell proliferation of CNE2 cells. In addition, the in vivo metastatic potential of CNE2 cells transfected with Vimentin shRNA was suppressed in a nude mouse model of pulmonary metastasis. Silencing of Vimentin in CNE2 cells leads to a decrease of microvessel density and VEGF, CD31, MMP2, and MMP9 expressions in pulmonary metastatic tumors. Importantly, we found that it is easier for the tumor cells from the high vimentin-expressing pulmonary metastatic tumors to reinvade the microvessel and to form stable tumor plaques attached to the endothelial cells, which resemble the resource of circulating tumor cells and are very hard to eliminate. However, depletion of vimentin inhibits the formation of vascular tumor plaques. Our findings suggest that RNAi-based vimentin silencing may be a potential and promising anti-metastatic therapeutic strategy for NPC.

MiR-206 enhances nasopharyngeal carcinoma radiosensitivity by targeting IGF1

Radioresistance remains a major problem in nasopharyngeal carcinoma (NPC) treatment. However, the underlying molecular mechanisms of NPC radioresistance remain poorly understood. The present study aimed to investigate the potential role and mechanism of miR-206 in NPC radioresistance. We observed that miR-206 was down-regulated in radioresistant NPC cells. Furthermore, restoration of miR-206 in CNE2-IR cells suppressed enhanced radiosensitivity of NPC cells. In contrast, inhibition of miR-206 in CNE2 cells reduced the radiosensitivity. We also found that miR-206 directly targeted IGF1 and inhibited the PI3K/AKT pathway. Our data demonstrate that miR-206 sensitizes NPC cell to irradiation by targeting IGF1, highlighting the therapeutic potential of miR-206 in NPC radiosensitization.

Abstract 14: Anticancer activities of terpenoid compounds isolated from the plant centipeda minma against nasopharyngeal carcinoma cells

Abstract Nasopharyngeal carcinoma (NPC) is one of common cancers throughout south-east Asia, southern China and other regions. Radiotherapy and chemotherapy are the standard treatments for NPC with severe adverse effects, multi-drug resistance, and insensitivity to advanced NPC. Complementary and novel treatments for NPC gain considerable interest around the world. The medicinal plant Centipeda minma is traditionally used in China for the treatment of various nasal diseases such as allergy, rhinitis, sinusitis and nasopharyngeal carcinoma. In the current study, we studied the anticancer potential of an ethanol extract (CME) and 3 pure sesquiterpenoids (A1, A2, A3) extracts from Centipeda minma against NPC cells in vitro and some underlying mechanisms of actions. The NPC cell lines CNE-1 and CNE-2 cells were treated with either CME or 3 pure compounds (A1, A2, A3). Proliferation of NPC cells was inhibited in a concentration- and time-dependent manner. For 48 h treatment, the IC50 values were 41.57 to 24.98 μg/mL for CME, and 2.3 to 7.5 μM for A1 to A3. While these extracts showed no appreciable effect on normal human LO2 hepatocytes, significant numbers of NPC cells underwent apoptotic morphological changes following treatments. Cytometric analysis demonstrated that treatments with CME and compounds results in NPC cell cycle arrest at the G2/M phase and eventually apoptosis in a concentration and time-dependent manner. Western blot analysis showed that these extracts could down-regulate Bcl-2 expression, up-regulate Bax expression and caspase-8, 9, 3 activities. In addition, the potential anti-NPC actions might be also associated with the marked inhibition of multiple signal transduction pathways including EGFR, VEGFR, HER2, FGFR, IGF-1R, PI3K/AKT/mTOR, MAP/ERK and Jan/Stat3 pathways. In summary, the Centipeda minma extract and terpenoids are potential apoptosis inducing agents to kill NPC cells and may be promising anti-cancer drug leads against nasopharyngeal carcinoma. The exact mechanism of actions remains further study. Note: This abstract was not presented at the meeting. Citation Format: Bei-bei Liu, Kui-yuan Zhu, Chi-on Chan, Ling-Hua Zhang, Daniel Kam-Wah Mok, Si-bao Chen. Anticancer activities of terpenoid compounds isolated from the plant centipeda minma against nasopharyngeal carcinoma cells [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 14. doi:10.1158/1538-7445.AM2017-14