Laryngeal Cancer Cell Line Hep-2 Research Articles

Synthesis of Zinc oxide nanoparticles from Marsdenia tenacissima inhibits the cell proliferation and induces apoptosis in laryngeal cancer cells (Hep-2)

Biosynthesis of Zinc oxide nanoparticles (ZnONPs) from natural plants stands as a promising nanodrug delivery system in cancer therapeutics. Marsdenia tenacissima (M.t), a Chinese medicinal plant has been extensively used as clinical remedy for treating several types of cancer. In this present study, ZnONPs were synthesized from Marsdenia tenacissima and its anti cancer potency was assessed against in vitro laryngeal cancer cell line Hep-2. The biosynthesized Marsdenia tenacissima Zinc Oxide Nanoparticles [M.t-ZnONPs] was characterized using UV–visible Spec, SEM, TEM and EDAX analysis. The cytotoxic and apoptotic inducing potential of M.t-ZnONPs was assessed by MTT assay and staining such as DCFH-DA, AO/EtBr, Rhodamine 123, DAPI and comet assay. The anticancer potential of M.t-ZnONPs was analysed by Real time PCR analysis of proapoptotic, antiapoptotic and caspases proteins. Our present findings showed characteristic and morphological representation of synthesized M.t-ZnONPs by UV–visible Spec, SEM, TEM and EDAX analysis. M.t-ZnONPs exhibits its cytotoxicity by inhibiting the viability of Hep-2 cells and IC50 value was obtained by MTT assay. The results of apoptotic staining techniques in M.t-ZnONPs treated Hep-2 cells confirm with excess ROS generation, disruption of mitochondrial membrane potential and nuclear damage. The apoptotic inducing potential of M.t-ZnONPs was also evidenced by upregulation of proapoptotic proteins Bax, Caspase 3 & 9 and downregultion of antiapoptotic protein Bcl-2 by RT-PCR analysis. Finally, these results suggested that biosynthesized M.t-ZnONPs is an effective anticancer agent which induces apoptosis in Hep-2 laryngeal cell line and thus conclude that M.t-ZnONPs, a valid anticancer strategy in treating various cancer.

Evaluation of anticancer activity of Melaleuka alternifolia (i. e. tea tree oil) on laryngeal cancer cell line (Hep2) - an in-vitro study

Introduction and Aims A naturally available plant extract of Melaleuka alternifolia tea tree oilTTO is used as a very good antibacterial antifungal antiviral antiprotozoal and anti-inflammatory agent. Currently lot of importance is given for its anticancer effect. Our aim was to evaluate anticancer activity of Melaleuka alternifolia against laryngeal cancer cell line Hep2.Methodology Two different cell lines were used to know the cell viability and cell lysis cytotoxicity in laryngeal cancer Hep2 and monkey kidney cell line Vero used as control. Cell culture The cell lines were maintained in 96 wells micro titer plate containing MEM media supplemented with 10 heat inactivated fetal calf serum FCS containing 5 of mixture of Gentamicin 10ug Penicillin 100 Unitsml and Streptomycin 100microgml in presence of 5 CO2 at 37ordmC for 48-72 hours. Cytotoxicity Assay In vitro growth inhibition effect of test compound was assessed by calorimetric or spectrophotometric determination of conversion of MTT intonbsp Formazan blue by living cells.Results The results represent the mean of five readings. The concentration at which the OD of treated cells was reduced by 50 i.e IC50 value is 0.781microgml of TTO with respect to the untreated control. The standard formula was used for the calculation of cell viability and cell lysis. showed Spearmans Correlation Coefficient Correlation with P value lt0.001 indicating significant results when TTO was treated with Hep2 and Vero cell line. Conclusion TTO is having very good anticancer property against laryngeal cancer cell line Hep2. There was no cytotoxicity noted with Monkey Kidney Vero cell line. The current study can be brought to the level of clinical trials which can show TTO with its greater efficacy related to anticancer activity.

Overexpression of Beclin1 inhibits proliferation and promotes apoptosis of human laryngeal squamous carcinoma cell Hep-2.

ObjectiveBeclin1 was previously found to be downregulated in human laryngeal cancer (LC) tissues, and it results in poor prognosis. This study aimed to further confirm the antitumor effects of Beclin1 in LC cell line Hep-2.Materials and methodsBeclin 1 was overexpressed in Hep-2 cells using liposomal transfection and confirmed using reverse transcription polymerase chain reaction and Western blotting. Then, cell proliferation and apoptosis were determined in control (untransfected), empty vector transfected, and Beclin1 overexpressed groups using MTT and flow cytometry procedure, respectively.ResultsThe expression of the Beclin1 gene in Hep-2 cells was significantly increased after vector transfection compared with control (1.173±0.046 vs 0.453±0.016, P<0.01) and empty vector (1.173±0.046 vs 0.440±0.021, P<0.01). Overexpression of Beclin1 inhibited proliferation at 4 days (0.619±0.051 vs 0.891±0.081 and 0.619±0.051 vs 0.878±0.105, P<0.01), 5 days (0.684±0.078 vs 1.127±0.094 and 0.684±0.078 vs 1.162±0.117, P<0.01), and 6 days (0.725±0.069 vs 1.168±0.103 and 0.725±0.069 vs 1.194±0.097, P<0.01) and promoted apoptosis (14.48%±1.42% vs 4.07%±0.66% and 14.48%±1.42% vs 4.39%±0.80%, P<0.01) in Hep-2 cells in comparison with the control and empty vector groups, respectively.ConclusionBeclin1 may be an underlying target for the treatment of LC. This study has provided some experimental basis for the gene therapy of LC.

Overexpression of miR-26b decreases the cisplatin-resistance in laryngeal cancer by targeting ATF2.

Cisplatin is a common used chemotherapeutic drug for the treatment of laryngeal cancer. However, drug-resistance is a major obstacle in platinum-based chemotherapy for laryngeal cancer. Recent studies have demonstrated that dysregulation of microRNAs (miRNAs) is responsible for chemoresistance in multiple cancers including laryngeal cancer, but the potential mechanisms are required to be explored. In the present study, we constantly exposed the laryngeal cancer cell line Hep-2 with cisplatin to establish a cisplatin-resistant laryngeal cancer cell model (Hep-2/R). We found that Hep-2/R cells exhibited obvious resistance to cisplatin compared to the Hep-2 cells. However, overexpression of miR-26b significantly decreased the half maximal inhibitory concentration (IC50) of cisplatin to Hep-2/R. Mechanically, miR-26b in Hep-2/R decreased the expression of ATF2, and thus inhibiting the phosphorylation of ATF2 and formation of cellular ATF2-c-Jun complex induced by cisplatin. As the results, Hep-2/R cells failed to overexpress the Bcl-xl which is a key anti-apoptotic protein under the cisplatin treatment. Therefore, overexpression of miR-26b was found to be able to promote mitochondrial apoptosis induced by cisplatin.

Tumor necrosis factor α accelerates Hep-2 cells proliferation by suppressing TRPP2 expression.

TRPP2, a Ca2+-permeable non-selective cation channel, has been shown to negatively regulate cell cycle, but the mechanism underlying this regulation is unknown. Tumor necrosis factor α (TNF-α) is a proinflammatory cytokine extensively involved in immune system regulation, cell proliferation and cell survival. However, the effects and mechanisms for the role of TNF-α in laryngeal cancer remain unclear. Here, we demonstrated using western blot analyses and intracellular Ca2+ concentration measurements that TNF-α treatment suppressed both TRPP2 expression and ATP-induced Ca2+ release in a laryngeal cancer cell line (Hep-2). Knockdown of TRPP2 by a specific siRNA significantly decreased ATP-induced Ca2+ release and abolished the effect of TNF-α on the ATP-induced Ca2+ release. TNF-α treatment also enhanced Hep-2 cell proliferation and growth, as determined using cell counting and flow cytometry cell cycle assays. Moreover, TNF-α treatment down-regulated phosphorylated protein kinase R-like endoplasmic reticulum kinase (p-PERK) and phosphorylated eukaryotic translation initiation factor (p-eIF2α) expression levels, without affecting PERK and eIF2α expression levels in Hep-2 cells. We concluded that suppressing TRPP2 expression and TRPP2-mediated Ca2+ signaling may be one mechanism underlying TNF-α-enhanced Hep-2 cell proliferation. These results offer new insights into the mechanisms of TNF-α-mediated laryngeal cancer cell proliferation, and provide evidences showing a potential role of TNF-α in the development of laryngeal cancer.

Differentially expression p21 and p53 in laryngeal squamous cell carcinoma

AbstractObjective:To investigate the role of the methylation of p21 and p53 gene in laryngeal cancer and laryngeal cancer cell line Hep-2.Method: Methylation of p21 and p53 gene were detected by methylation specific PCR(MSP) in 46 cases with paired cancer tissues and adjacent tissues. Hep-2 cell line was treated with 5-azacytidine at different time points, and Hep-2 cell growth was detected using the MTT assay. Hep-2 cell line was treated with 5-azacytidine at different time points, and then apoptosis was detected by the TUNEL assay. The expression difference of p21 mRNA was detected by RT-PCR method before and after intervention. p21 promoter CpG island methylation status was tested by MSP before and after intervention.Result: The incidence was 45.7% of p21 gene promoter CpG island methylation in 46 cases of laryngeal cancer, while methylation rate in adjacent tissues was 10.9%. There were significant differences between cancer tissues and adjacent tissues(P<0.05).The incidence was 6.5% of p53 gene promoter CpG island methylation in 46 cases of laryngeal cancer, while methylation rate was 4.3% in adjacent tissues,no significant difference of p53 gene methylation was found in laryngeal cancer and counterparts adjacent tissues(P>0.05). The effect of Hep-2 proliferation inhibition interfered by 5-azacytidine was gradually increased over time in a time-dependent manner. Meanwhile, interfered by 5-azacytidine increased the apoptosis in a time-dependent manner. After interference by 5-azacytidine, p21 gene is activated. The expression of p21 mRNA was significantly higher. The p21 gene methylation degree in laryngeal cancer cell line Hep-2 was 43.13%±0.79%. After 5-azacytidine intervention, the degree of methylation was obviously decreased and even showed unmethylation.Conclusion:There was p21 gene promoter CpG island hypermethylation in laryngeal cancer and laryngeal cancer cell line Hep-2, which was a molecular event distinguished laryngeal cancer from normal laryngeal tissue. There was p53 gene promoter CpG island hypomethylation in laryngeal cancer and laryngeal cancer cell line Hep-2.Inactivation of the gene may occur by gene mutation forms and others. Demethylation of drug 5-azacytidine can induce p21 gene promoter CpG island demethylation modification, change the regulation of tumor cell cycle genes in cells and promote tumor cell apoptosis.

Correlation between levels of expression of minichromosome maintenance proteins, Ki-67 proliferation antigen and metallothionein I/II in laryngeal squamous cell cancer.

MCM2, MCM3 and MCM7 are minichromosome maintenance proteins found in dividing cells and they play a role in DNA synthesis. Increased MCM expression level is observed in cells of different cancer types. Additionally, metallothioneins (MT-I/II) are involved in control of cell proliferation and differentiation and changes of their expression are observed in many types of cancer. Ki-67 is known cancer cell proliferation antigen currently used in prognostic evaluation. The study material consisted of 83 laryngeal squamous cell cancer (LSCC) cases and 10 benign hypertrophic lesions of larynx epithelium as a control group. For the present study, laryngeal cancer cell line HEp-2 and human keratinocytes were employed, and to evaluate expression of all the markers, immunohistochemical method (IHC), immunofluorescence (IF) and western blot analysis were used. Statistical analysis showed strong positive correlation between expression of MCM2, MCM3, MCM7 and Ki-67 antigen in LSCC. Additionally, moderate positive correlation was observed between MCM3 and MT-I/II expression. In cancer cells, the level of expression of MCM3, MCM2, MCM7 and Ki-67 markers was increasing with the grade of LSCC malignancy. IF and western blot analysis showed higher MCM2, MCM3, MCM7 expression in HEp-2 cells in comparison to their expression in keratinocytes. MCM proteins might be useful markers of cell proliferation in LSCC.

Overexpression of SOX2 promotes migration, invasion, and epithelial-mesenchymal transition through the Wnt/β-catenin pathway in laryngeal cancer Hep-2 cells.

SOX2 is a high-mobility group box containing transcription factor essential for the maintenance of embryonic stem cells. Recent evidence indicates that SOX2 overexpression correlates with metastasis and poor prognosis in patients with laryngeal squamous cell cancer. To investigate how SOX2 contributes to this aggressive phenotype, we introduced the human SOX2 gene into a low SOX2-expressing human laryngeal cancer cell line Hep-2. Cell migration and invasion were determined by the Transwell assay with or without Matrigel coating. The epithelial-mesenchymal transition (EMT)-related markers were assayed by Western blot analysis or immunofluorescence. Our results showed that exogenous expression of SOX2 in Hep-2 cells substantially promoted their migratory and invasive capabilities in culture. Moreover, Hep-2 cells stably overexpressing SOX2 underwent EMT phenotype, as evidenced by mesenchymal morphology, decreased expression of epithelial marker (E-cadherin), and increased expression of mesenchymal markers (N-cadherin, vimentin, fibronectin, and α-smooth muscle actin). Strikingly, Western blot analysis and immunofluorescence also showed that overexpression of SOX2 resulted in substantial increase and nuclear accumulation of β-catenin in Hep-2 cells. However, small interfering RNA targeting β-catenin significantly attenuated the reduced expression of E-cadherin and increased cell migration and invasion abilities in SOX2-overexpressing cells, suggesting that SOX2-induced EMT process, migration, and invasion are dependent on β-catenin activation. Taken together, our findings underscore a novel role for SOX2 in laryngeal cancer migration and invasion.

Gene expression profile of 5-fluorouracil metabolic enzymes in laryngeal cancer cell line: Predictive parameters for response to 5-fluorouracil-based chemotherapy

Background5-fluorouracil (5-FU) is an antifolate chemotherapeutic that has become established in many therapeutic regimes, but sensitivity variations and development of resistance are common problems that limit the efficiency of the treatments. Inter-individual variations to 5-FU outcome have been attributed to different expression profiles of genes related to folate metabolism. MethodsTo elucidate the mechanisms of variations to 5-FU outcome, the authors investigated MTHFR, DHFR, TYMS and SLC19A1 folate genes expression for 5-FU response in laryngeal cancer cell line (Hep-2). Concentrations of 10, 50, and 100 ng/mL of 5-FU chemotherapeutic were added separately in Hep-2 cell line for 24hours at 37°C. Cell sensibility was evaluated with fluorescein isothiocyanate (FITC) label Bcl-2 by flow cytometry. The real-time quantitative PCR (qPCR) technique was performed for quantification of gene expression using TaqMan® Gene Expression Assay. ANOVA and Bonferroni's post hoc tests were utilized to statistical analysis. ResultsThe numbers of viable Hep-2 cells with 10, 50, and 100 ng/mL concentrations of 5-FU chemotherapy were 15.87, 28.3 and 68.9%, respectively. Statistical analysis showed significant association between control group and increased expression for TYMS gene in cells treated with 100 ng/mL/5-FU chemotherapy (P<0.05). ConclusionsThe authors found association between the highest 5-FU dose chemotherapy and increased expression levels for TYMS folate gene in laryngeal cancer cell line. Although these experiments were performed in vitro, the results suggest that genetic factors are thought to play an important role in drug metabolism and may be useful for predicting treatment outcomes.

EGFR-targeted poly(ethylene glycol)-distearoylphosphatidylethanolamine micelle loaded with paclitaxel for laryngeal cancer: preparation, characterization and in vitro evaluation

The objective of this study was to evaluate the potential of using polymeric micelles modified with a peptide (termed GE11) ligand of epidermal growth factor receptor as the targeted carriers to achieve increased accumulation in laryngeal cancer and enhanced intracellular delivery for the encapsulated anticancer drugs. Poly (ethylene glycol)-distearoylphosphatidylethanolamine (PEG-DSPE) micelles containing paclitaxel were prepared via film-hydration method followed by investigation of in vitro release of paclitaxel in phosphate-buffered saline. The average size of GE11-PEG-DSPE/paclitaxel micelle and mPEG-DSPE/paclitaxel were 35 ± 2.8 nm [the polydispersity index (PDI) = 0.207] and 28 ± 2.1 nm (PDI = 0.154), respectively. Micelles with or without GE11-modified had similar physicochemical properties. Transmission electron microscopy showed that the micelles were homogeneous and spherical in shape. Encapsulation efficiency and drug loading of the micelle were 74.11 ± 3.89% and 3.58 ± 2.82%, respectively. The in vitro targeting characteristic of GE11-modified micelles was investigated by observing the level of cellular uptake of fluorescent coumarin-6-loaded micelles on EGFR over-expressed human laryngeal cancer cell line Hep-2 and EGFR low-expressed human leukemic cell line U-937. Hep-2 cell proliferation was significantly inhibited by GE11-PEG-DSPE/paclitaxel micelle compared to mPEG-DSPE/paclitaxel micelle and Taxol in vitro. Our results suggested that GE11-PEG-DSPE micelle could be a promising strategy for enhancing paclitaxel’s chemotherapeutic effects on EGFR over-expressed cancer cells.

Identification of thePAG1Gene as a Novel Target of Inherent Radioresistance in Human Laryngeal Carcinoma Cells

Laryngeal carcinoma, as a malignant tumor that occurs in the head and neck region, is widely treated by radiation, but in some cases, the cancer is radioresistant to the radiotherapy. The reason for the radioresistant response needs to be clinically understood. We designed our present study to identify the molecules that may be involved in this radioresistant response. In this study, we initially established the inherent radioresistant (Hep-2max) and radiosensitive (Hep-2min) cell lines from the parental laryngeal cancer cell line Hep-2. Furthermore, using microarray analysis, we identified a novel inherent radioresistance-related gene, phosphoprotein associated with glycosphingolipid-enriched microdomains1 (PAG1). We showed that siRNA directed against PAG1 in a radioresistant (Hep-2max) cell line dramatically enhanced the radiosensitivity and IR-induced cell death. On the contrary, ectopic expression of PAG1 in radiosensitive (Hep-2min) cell lines led to radioresistance and suppressed the IR-induced cell death. Taken together, our results indicate that the PAG1 gene may be a novel, promising radiosensitization target for laryngeal carcinoma.

Knockdown of ZNF403 inhibits cell proliferation and induces G2/M arrest by modulating cell-cycle mediators

ZNF403, also known as GGNBP2 (gametogenetin binding protein 2), is a highly conserved gene implicated in spermatogenesis. However, the exact biological function of ZNF403 is not clear. In this study, we identified the role of ZNF403 in cell proliferation and cell-cycle regulation by utilizing short hairpin RNA (shRNA)-mediated knockdown. ZNF403-specific shRNA expressing helper-dependent adenoviral vector (HD-Ad-ZNF403-shRNA) was constructed and transduced human cell lines. ZNF403 mRNA and protein expression levels were inhibited as evidenced by real-time PCR and western blot analyses. Noticeably, we found that knockdown of ZNF403 expression suppressed cell proliferation compared to the non-target shRNA and vector controls. Furthermore, cell-cycle analysis demonstrated that downregulation of ZNF403 promoted G2/M cell-cycle arrest in a dose-dependent manner. Moreover, human cell-cycle real-time PCR array revealed that ZNF403 knockdown influenced the expression profile of genes in cell-cycle regulation. Among these genes, western blot analysis confirmed the protein up-regulation of p21 and down-regulation of MCM2 in response to the ZNF403 knockdown. Additionally, knockdown of ZNF403 also showed an anti-carcinogenetic effect on anchorage-independent growth by colony formation assay and tumor cell migration by wound-healing assay with human laryngeal cancer cell line Hep-2 cells. Altogether, our findings suggest an essential role of ZNF403 in cell proliferation and provide a new insight into the function of ZNF403 in regulating the G2/M cell-cycle transition.

Suppression of Aurora-A by RNA interference inhibits laryngeal cancer Hep-2 cell growth

To investigate the effects of knockdown of Aurora-A by RNA interference on laryngeal cancer Hep-2 cell growth in vitro and in vivo. A plasmid containing siRNA against Aurora-A was constructed and transfected into human laryngeal cancer cell line Hep-2. Measurements included the CCK-8 assay for viability and proliferation, Transwell assay for invasion, colony formation assay for cell anchorage-independent growth. Western blot and immunohistochemistry assay for protein expression. Tumorigenicity was observed in vivo. In Hep-2 cells transfected by Aurora-A siRNA (designated as siRNA-3), protein expression of Aurora-A was suppressed by 52%. In CCK-8 assay, absorbance value of siRNA-3 cells (3.268 ± 0.106, (x(-) ± s)) was lower than that of Hep-2 cells (3.722 ± 0.152, F = 17.634, P < 0.001). In Transwell assay, the average invasive cells per field in siRNA-3 cells (110.0 ± 18.0) was less than that in Hep-2 cells (236.0 ± 26.0, F = 26.462, P < 0.01). In colony formation assay, the average colony number of siRNA-3 cells (31.0 ± 6.6) was lower than that of Hep-2 cells (104.0 ± 14.0). The average tumor size in siRNA-3 group was (127.77 ± 174.83) mm(3), which was less than Hep-2 cell group (837.26 ± 101.80) mm(3), (F = 28.187, P < 0.001). Silencing of Aurora-A decreased the expression of focal adhesion kinase (FAK) and matrix metalloproteinase-2 (MMP-2), key regulators in cell adhesion and invasion. The knockdown of Aurora-A inhibits the growth and invasiveness of Hep-2 cells in vitro and in vivo, which may be a promising therapeutic strategy for LSCC.

Inhibition of cell proliferation and arrest of cell cycle progression by blocking chloride channels in human laryngeal cancer cell line Hep-2

Chloride channel (ClC) is involved in normal physiological processes and pathology of various diseases. Although it is recognized that blockade of ClC inhibits the cell proliferation, it is not well understood the potential function of ClC in laryngeal cancer. In this study, we investigated the effect of the ClC inhibitor on cell proliferation, cell cycle progression in human laryngeal cancer cell line Hep-2, as well as the effect on the phosphorylation levels of ERK1/2 and AKT1. In this study crystal violet method was used to study the effect of the ClC inhibitor, 5-nitro-2-(3-phenylpropylamino) benzoic acid, NPPB, on Hep-2 cell proliferation. The impaction of the inhibitor on the cell cycle distribution was investigated by the flow cytometry (FCM). Western blot was performed to measure the phosphorylation levels of ERK1/2 and AKT1. Our data indicated ClC played an important role in Hep-2 cell proliferation and cell cycle. NPPB inhibited Hep-2 cell proliferation when compared with the controls. Blockade of ClC arrested cell cycle progression and suppressed the phosphorylation of ERK1/2 and AKT1 in Hep-2 cells by inhibition of cell proliferation by CIC inhibitor (NPPB) could be through arresting cell cycle progression, which is probably by suppressing phosphorylation of ERK1/2 and AKT1.

Suppression of Survivin Expression by Short Hairpin RNA Induces Apoptosis in Human Laryngeal Carcinoma Cells

Purpose: The aim of this study was to evaluate the suppression effect of survivin shRNA on the expression of the survivin gene in the human laryngeal cancer cell line Hep-2. Procedures: 60 cases of laryngeal squamous-cell carcinoma (LSCC) and 10 cases of normal laryngeal mucosa were examined using immunohistochemistry to determine whether the expression of survivin correlated with tumorigenesis. Three plasmid vectors of short hairpin RNA (shRNA) specific for survivin were designed and generated. Western blot and real-time PCR analysis of survivin expression in Hep-2 cells was performed 48 h after transfection. The growth curve was used to determine the cell proliferation. Propidium iodide (PI) single staining was applied to detect the cell cycle. The apoptosis of the cells was analyzed by flow cytometry with the FITC-annexin-V/PI double staining and PI single staining. Results: 68.33% (41 out of 60) of tumors were positive for survivin expression and significantly associated with lymph node metastasis and advanced stage. In contrast, no expression of survivin in normal mucosa was detected. Transfection of Hep-2 cells with survivin shRNA significantly inhibited survivin expression at both the mRNA and the protein level in Hep-2 cells. Downregulation of survivin resulted in increasing the apoptosis index, but the results showed no obvious influence on cell cycle. Conclusions: This study demonstrates that survivin shRNA effectively inhibits survivin gene expression in Hep-2 cells leading to growth suppression and apoptotic induction in Hep-2 cells.

NK-1 receptor antagonists induce apoptosis and counteract substance P-related mitogenesis in human laryngeal cancer cell line HEp-2

It has been demonstrated that substance P (SP) induces cell proliferation and neurokinin-1 (NK-1) receptor antagonists inhibit growth in several human cancer cell lines, but it is currently unknown whether such actions are exerted on human laryngeal carcinoma cell line HEp-2. In addition, the presence of NK-1 receptor has not been demonstrated in this cell line. We carried out an in vitro study of the growth inhibitory capacity of the NK-1 receptor antagonists L-733,060 and L-732,138 against human laryngeal carcinoma cell line HEp-2. Coulter counter was used to determine viable cell numbers followed by application of the tetrazolium compound MTS. Furthermore, an immunoblot analysis was used to determine the NK-1 receptor, and the 4',6-diamidino-2-phenylindole (DAPI) method was applied to demonstrate apoptosis of the laryngeal carcinoma cells. We observed the presence of several NK-1 receptors isoforms (34, 46, 58 and 75 kDa). Nanomolar concentrations of SP increased the growth rate of the cell line and micromolar concentrations of L-733,060 and L-732,138 inhibited the growth of the HEp-2 cells in a dose-dependent manner, with and without previous administration of SP. The 50% inhibition concentration values were 21.34 microM and 37.97 (48 h) respectively for HEp-2. NK-1 receptor presence on HEp-2 cells was confirmed by western blotting. DAPI staining revealed the presence of apoptosis following NK-1 receptor antagonists treatment. We demonstrated that NK-1 receptors were present in this laryngeal cancer cell line; these findings demonstrate that SP acts as a mitogen on the human laryngeal carcinoma cell line HEp-2 through the NK-1 receptor, and also indicate that both NK-1 receptors antagonists induced apoptosis of the tumour cells. This new action, reported here for the first time, suggests that the NK-1 receptor is a new and promising target in the treatment of human laryngeal carcinoma.

Effects of laryngeal cancer cell line Hep-2 to paclitaxel sensitivity induced by RNAi survivin gene

目的 探讨运用RNA干扰技术阻断喉癌细胞系Hep-2中survivin基因的表达,并研究survivin基因沉默后Hep-2对紫杉醇敏感性的影响.方法 化学合成21bp目的基因siRNA片段,并将不同浓度的siRNA用脂质体法转染喉癌细胞系Hep-2.用空脂质体和GFP-siRNA作平行对照.通过蛋白印迹法检测survivin表达量的变化,MTT法检测转染后Hep-2细胞对紫杉醇敏感性的变化.结果 2 5nM和5 0nM的siRNA可以有效地阻断了Hep-2细胞survivin蛋白的表达;转染后Hep-2细胞在体外对紫杉醇的敏感性增加.结论 初步阐明survivin在喉癌细胞对紫杉醇敏感性中的作用,为进一步探讨survivin基因与喉癌的关系以及联合治疗研究奠定了基础。

Targeted therapy of human laryngeal squamous cell carcinoma in vitro by antisense oligonucleotides directed against telomerase reverse transcriptase mRNA

A number of different approaches have been developed to inhibit telomerase activity in human cancer cells. In this study, the effect of antisense oligonucleotides (ODNs) by targeting human telomerase reverse transcriptase (hTERT) mRNA in a laryngeal cancer cell line (Hep-2) was investigated. A 20mer antisense oligodeoxynucleotide targeting the most open part of hTERT mRNA (anti-hTERT) and a mismatched control sequence were synthesized. Cells were treated daily with oligonucleotides for up to 72 hours. hTERT mRNA expression was measured by the reverse transcription polymerase chain reaction (RT-PCR) assay; telomerase activity by the telomerase PCR ELISA assay kit (TRAP; Boehringer Mannheim, GmbH, Mannheim, Germany). Cell viability after administration of ODNs was determined using the MTT assay. Morphological changes were examined by haematoxylin and eosin staining. The cell cycle was analyzed using flow cytometry. It was found that antisense treatment induced a decrease in hTERT mRNA expression, telomerase activity, cell growth rate, cell viability, and an increase in apoptosis. The results suggest that inhibition of telomerase activity in Hep-2 cells by short-term antisense treatment against the mRNA of hTERT results in apoptotic cell death. The treatment with anti-hTERT may be useful as a treatment modality for laryngeal squamous carcinoma.

Growth inhibition of human laryngeal cancer cell with the adenovirus-mediated p53 gene

Objective: In most laryngeal cancers, the function of p53 gene is down regulated. To explore the potential use of p53 in gene therapy of laryngeal cancer, by introducing wild-type p53 into laryngeal cancer cell line via a recombinant adenoviral vector, Ad5CMV-p53 and analyzing its effects on cell and tumor growth. Methods: A human laryngeal cancer cell line Hep-2 was used. Recombinant cytomegaiovirus-promoted adenoviruses containing human wild-type p53 cDNA was transiently introduced into Hep-2 line. The growth suppression of the Hep-2 cells and established s.c. squamous carcinoma model was examined. The p53 protein expression was detected using immunohistochemical analysis. Results: The transduction efficiencies of Hep-2 cell line were 100% at a multiplicity of 100 or greater. The p53 protein expression peaked on day 2 after infection and lasted far 5 days. In vitro growth assays revealed cell death following Ad5CMVp53 infected. In vivo studies, Ad5CMV-p53 inhibited the tumorigenicity of Hep-2 cell, and in nude mice with established s.c. squamous carcinoma nodules showed that tumor volumes were significantly reduced in mice that received peritumoral infiltration of Ad5CMV-p53. Conclusion: Adenovirus-mediated antitumor therapy carrying the p53 gene is an efficient method to inhibit laryngeal cancer growth. Transfection of laryngeal cancer cells with the wild-type p53 gene via Ad5CMV-p53 is a potential novel approach to the therapy of laryngeal cancer.