RESUMEN
Phellintremulin A (1), a rearranged sesquiterpenoid with an unprecedented bicyclic backbone, and two previously unreported illudane-type sesquiterpenoids, namely phellintremulin B (2) and phellintremulin C (3), together with two known analogues (±)â4 and (±)â5, were isolated from cultures of the medicinal fungus Phellinus tremulae. Their structures and absolute configurations were established by means of spectroscopic data and HRESIMS analyses, as well as ECD and NMR calculations. A plausible biogenesis for 1 was discussed. The electrophysiological experiments showed that phellintremulins (AâC) can inhibit Nav current in DRG neuron cells at 10 µM, with percentage inhibitions of 23.2%, 49.3%, and 31.7%, respectively. The antinociceptive activities of phellintremulins (AâC) were evaluated via the acetic acid-induced writhing test in mice at a dose of 3 mg/kg. They showed significant antinociceptive effects with percentages of inhibition of 43.8%, 54.4%, and 50.6%, respectively, and phellintremulin B and C expressed more potent analgesic effect than lidocaine.
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Analgésicos , Basidiomycota , Sesquiterpenos , Analgésicos/farmacología , Analgésicos/química , Analgésicos/aislamiento & purificación , Animales , Sesquiterpenos/farmacología , Sesquiterpenos/química , Sesquiterpenos/aislamiento & purificación , Ratones , Basidiomycota/química , Estructura Molecular , Masculino , Relación Dosis-Respuesta a Droga , Relación Estructura-ActividadRESUMEN
Eight undescribed phenylpropanoid-dihydrochalcone hybrids, namely (+)- and (-)-malahupin A, (+)- and (-)-malahupin B, (±)-malahupin C, malahupinosides A and B, 7â´-epi-malahupinoside B, together with two known compounds, phloretin and phlorizin, were isolated from the leaves of the folk medicinal plant Malus hupehensis. Their structures were elucidated by extensive NMR and MS spectroscopic methods, chiral-phase analysis, and ECD calculations. Compounds (+)-malahupin B and malahupinoside B showed weak inhibition activities against the nitric oxide production in liposaccharide-induced murine RAW264.7 macrophages with IC50 values of 36.7 and 27.0 µM, respectively. Compounds (+)- and (-)-malahupin A, (+)- and (-)-malahupin B exhibited significant α-glucosidase inhibitory activity, with IC50 values of 22.5, 19.1, 19.2, and 17.4 µM, respectively. The postulated biosynthetic pathways to these hybrid compounds were proposed. This work represents the first report of the natural phenylpropanoid-dihydrochalcone hybrid compound, and lays foundation for the study on the bioactive principles of the ethnic hypoglycemic medicinal plant.
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INTRODUCTION: To report a rare case of male breast micropapillary carcinoma (MBMC) with early metastasis of axillary lymph nodes, the molecular characteristics were further studied in both primary and metastatic foci. In addition, we have reviewed similar published cases in the literature and tried to outline the molecular characteristics of this disease. PRESENTATION OF CASE: A 63-year-old male patient presented with a painless mass on the medial side of left breast and was pathologically diagnosed with MBMC. Postoperative examination revealed 80 % invasive ductal carcinoma (IDC) and 20 % invasive micropapillary carcinoma (IMPC) in the mass, with a histological grade WHO III. There were 25 axillary lymph nodes, 11 of which were metastatic, including 5 macrometastasis and 1 micrometastasis, with a lymph node metastasis rate of 44 % (11/25). Pathological TNM stage: pT2N2M0. Immunohistochemical results in primary foci: AR (90 %, +), HER- 2 (1 +) and ER (90 %, +), PR (60 %, +), E - cadherin (+), EGFR (-), GATA - 3 (90 %, 3 +), Ki - 67 (50 %). Lymph node metastasis: AR (40 %, strong +), HER-2 (2+), ER (90 %, strong +), PR (40 %, strong +), Ki-67 (50 %). AR and Ki-67 were obviously expressed in both primary and metastatic foci. A mixture of IDC and IMPC was found in lymph node metastases, both of which expressed varying degrees of AR and Ki-67. CLINICAL DISCUSSION: MBMC is easy to early metastasized to lymph node. In this case, there was no significant difference between primary and metastatic cancer in molecular results. It is positive for ER and PR, but negative for HER-2 in this patient. There is few data on male HER-2 expression, HER-2 expression is deficient in this case. AR is found to be positive in 50 % of MBMC cases, although their clinical relevance has not been established yet. The significance of EGFR in the prognosis of MBMC remains unclear, however, EGFR positive expression is not found in this patient. CONCLUSIONS: MBMC is a rare disease characterized by early lymph node metastasis, high histological grade, positive ER and PR, and generally negative HER-2. The molecular biological characteristics and prognostic significance of MBMC need to be further studied in order to develop the optimal treatment strategy.
RESUMEN
During a screening for novel and useful actinobacteria in desert animal, a new actinomycete was isolated and designated strain TRM63209T. The strain was isolated from in vivo of a Blattella germanica in Tarim University in Alar City, Xinjiang, north-west China. The strain was found to exhibit an inhibitory effect on biofilm formation by Candida albicans ATCC 18,804. The strain was observed to form abundant aerial mycelium, occasionally twisted and which differentiated into spiral spore chains. Spores of TRM63209T were observed to be oval-shaped, with a smooth surface. Strain TRM63209T was found to grow optimally at 28 °C, pH 8 and in the presence of 1% (w/v) NaCl. The whole-cell sugars of strain TRM63209T were rhamnose ribose, xylose, mannose, galactose and glucose, and the principal polarlipids were found to be diphosphatidylglycerol, phos-phatidylethanolamine, phosphatidylcholine, phosphatidylinositol mannoside, phosphatidylinositol and an unknown phospholipid(L). The diagnostic cell wall amino acid was identified as LL-diaminopimelic acid. The predominant menaquinone was found to be MK-9(H6) (14.64%), MK-9(H2) (19.65%), MK-9(H8) (22.34%), MK-10(H2) (25.37%). The major cellular fatty acids were identified as iso-C16:0, 16:0, anteiso-C15:0, anteiso-C17:0, iso-C15:0 and Sum in Feature 3. Analysis of the 16S rRNA sequence showed that strain TRM63209T exhibits high sequence similarity to Streptomyces bungoensis strain DSM 41781T 98.20%. A multi-locus sequence analysis of five house-keeping genes (atpD, gyrB, rpoB, recA and trpB) and phylogenomic analysis also illustrated that strain TRM63209T should be assigned to the genus Streptomyces. The DNA G + C content of the strain was determined to be 70.2 mol%. Average nucleotide identity (ANI) between strain TRM63209T and S. bungoensis DSM 41781T, Streptomyces phyllanthi PA1-07T, Streptomyces longwoodensis DSM 41677T and Streptomyces caeruleatus NRRL B-24802T were 82.76%, 82.54%, 82.65%, 84.02%, respectively. Digtal DNA-DNA (dDDH) hybridization were 26.30%, 25.10%, 26.20%, 29.50%, respectively. Therefore, it is concluded that strain TRM63209T represents a novel species of the genus Streptomyces, for which the name Streptomyces blattelae is proposed. The type strain is TRM63209T (CCTCC AA 2018093T = LMG 31,403 = TRM63209T).
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Actinobacteria , Streptomyces , Actinobacteria/genética , ADN Bacteriano/genética , Humanos , ARN Ribosómico 16S/genética , Análisis de Secuencia de ADN , Streptomyces/genéticaRESUMEN
A novel Streptomyces strain, designated TRM43335T, was isolated from the Taklimakan desert in Alar City, Xinjiang, north-west China. The strain was found to exhibit an inhibitory effect on biofilm formation by Candida albicans and Staphylococcus epidermidis. A polyphasic approach was used to determine its taxonomic status. The strain was observed to form abundant aerial mycelium, occasionally twisted and which differentiated into spiral spore chains. Spores of TRM43335T were observed to be oval-shaped, with a smooth surface. Strain TRM43335T was found to grow optimally at 37 °C, pH 8 and in the presence of 1% (w/v) NaCl. The major sugars were identified as ribose, xylose, glucose, mannose and galactose, and the principal phospholipids were found to be diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylglycerol, phosphatidylinositol mannoside and phosphatidylinositol. The diagnostic cell wall amino acid was identified as LL-diaminopimelic acid. The predominant menaquinone was found to be MK-9(H6). The major cellular fatty acids were identified as iso-C16:1 H, anteiso-C15:0, iso-C16:0, anteiso-C17:0, anteiso-C17:1 w9c and iso-C15:0. Analysis of the 16S rRNA sequence showed that strain TRM43335T exhibits high sequence similarity to Streptomyces desertarenae SYSU D8023T 98.69%. A multilocus sequence analysis of five house-keeping genes (atpD, gyrB, rpoB, recA and trpB) also illustrated that strain TRM43335T should be assigned to the genus Streptomyces. The DNA G + C content of the strain was determined to be 72.8 mol%. The average nucleotide identity relatedness between strain TRM43335T and the phylogenetically related strain S. desertarenae SYSU D8023T was found to be 89.23%, and the in silico DNA-DNA hybridization value to be 36.70%. Therefore, it is concluded that strain TRM43335T represents a novel species of the genus Streptomyces, for which the name Streptomyces taklimakanensis sp. nov is proposed. The type strain is TRM43335T (CCTCC AA 2018052 T = KCTC 49254 T).
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Filogenia , Microbiología del Suelo , Streptomyces/clasificación , Streptomyces/aislamiento & purificación , Actinobacteria/clasificación , Técnicas de Tipificación Bacteriana , Composición de Base , Pared Celular/química , China , ADN Bacteriano/genética , Ácido Diaminopimélico/análisis , Ácidos Grasos/análisis , Tipificación de Secuencias Multilocus , Hibridación de Ácido Nucleico , Fosfolípidos/análisis , ARN Ribosómico 16S/genética , Streptomyces/genética , Streptomyces/fisiología , Vitamina K 2/análisisRESUMEN
AIMS: Pseudoginsenoside-F11 (PF11), an ocotillol-type ginsenoside, has been reported to exert wide-ranging neuroprotective properties. The aim of this study was to investigate the effect and potential mechanisms of PF11 on the autophagic/lysosomal pathway following ischemic stroke. METHODS: Male Sprague-Dawley rats underwent permanent middle cerebral artery occlusion (pMCAO). Cerebral ischemia outcome, TUNEL staining, Fluoro-Jade B staining were carried out 24 hours poststroke. The autophagic/lysosomal-related proteins were measured. RESULTS: A single administration of PF11 significantly decreased the infarct area, reduced the brain water content, and improved neurological functions, even 4 hours after the onset of pMCAO. Meanwhile, PF11 lessened the ischemic insult-mediated loss of neurons and activation of astrocytes and microglia. Furthermore, PF11 attenuated pMCAO-induced accumulations of autophagosomes and apoptosis. We further observed a remarkable effect of PF11 in reversing the ischemic insult-induced accumulation of autophagosomes (LC3-II) and abnormal aggregation of autophagic proteins (SQSTM1 and ubiquitin). Furthermore, PF11 was capable of improving lysosomal function and lysosome/autophagosome fusion following pMCAO, and this change was reversed by the lysosomal inhibitor chloroquine. Also, the improvement of ischemic outcome and the antiapoptotic effect induced by PF11 was reversed by CQ. CONCLUSION: These findings indicate that the autophagic flux is impaired in a rat model of pMCAO, and that PF11 exerts an excellent protective effect against ischemic stroke by alleviating autophagic/lysosomal defects.
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Autofagia/efectos de los fármacos , Isquemia Encefálica/tratamiento farmacológico , Encéfalo/efectos de los fármacos , Ginsenósidos/farmacología , Fármacos Neuroprotectores/farmacología , Accidente Cerebrovascular/tratamiento farmacológico , Animales , Apoptosis/efectos de los fármacos , Apoptosis/fisiología , Autofagia/fisiología , Encéfalo/patología , Encéfalo/fisiopatología , Edema Encefálico/tratamiento farmacológico , Edema Encefálico/patología , Edema Encefálico/fisiopatología , Isquemia Encefálica/patología , Isquemia Encefálica/fisiopatología , Cloroquina/farmacología , Modelos Animales de Enfermedad , Lisosomas/efectos de los fármacos , Lisosomas/patología , Lisosomas/fisiología , Masculino , Neuroglía/efectos de los fármacos , Neuroglía/patología , Neuroglía/fisiología , Neuronas/efectos de los fármacos , Neuronas/patología , Neuronas/fisiología , Ratas Sprague-Dawley , Accidente Cerebrovascular/patología , Accidente Cerebrovascular/fisiopatologíaRESUMEN
Drought stress is a major abiotic stress affecting plant growth and development. In this study, we performed the first dynamic phosphoproteome analysis of Brachypodium distachyon L. seedling leaves under drought stress for different times. A total of 4924 phosphopeptides, contained 6362 phosphosites belonging to 2748 phosphoproteins. Rigorous standards were imposed to screen 484 phosphorylation sites, representing 442 unique phosphoproteins. Comparative analyses revealed significant changes in phosphorylation levels at 0, 6, and 24 h under drought stress. The most phosphorylated proteins and the highest phosphorylation level occurred at 6 h. Venn analysis showed that the up-regulated phosphopeptides at 6 h were almost two-fold those at 24 h. Motif-X analysis identified the six motifs: [sP], [Rxxs], [LxRxxs], [sxD], [sF], and [TP], among which [LxRxxs] was also previously identified in B. distachyon. Results from molecular function and protein-protein interaction analyses suggested that phosphoproteins mainly participate in signal transduction, gene expression, drought response and defense, photosynthesis and energy metabolism, and material transmembrane transport. These phosphoproteins, which showed significant changes in phosphorylation levels, play important roles in signal transduction and material transmembrane transport in response to drought conditions. Our results provide new insights into the molecular mechanism of this plant's abiotic stress response through phosphorylation modification.
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Brachypodium/fisiología , Regulación de la Expresión Génica de las Plantas , Hojas de la Planta/fisiología , Proteínas de Plantas/metabolismo , Plantones/fisiología , Estrés Fisiológico/genética , Brachypodium/genética , Sequías , Perfilación de la Expresión Génica , Estrés Oxidativo , Fenotipo , Fosfoproteínas/metabolismo , Fosforilación , Fotosíntesis , Proteoma/metabolismo , Transducción de SeñalRESUMEN
OBJECTIVE: To detect the expression of histone deacetylase 6 (HDAC6) in laryngeal squamous cell carcinoma, and to analyze the effects of downregulation of HDAC6 expression on cell cycle, proliferation and migration of laryngeal squamous cell carcinoma cell line Hep-2 cells, and to explore their possible molecular mechanisms. METHODS: Immunohistochemistry was used to detect the expression of HDAC6 protein in 55 cases of laryngeal squamous cell carcinoma and 20 cases of normal laryngeal mucosa. HDAC6 siRNA and control siRNA were transfected into Hep-2 cells via lipofectamine 2000, and the interfering effect was analyzed using Western blotting. The effects of downregulation of HDAC6 expression on cell cycle, proliferation and migration were determined by cell counting kit-8 (CCK-8), flow cytometry and Boyden chamber, respectively. Finally, Western blotting was used to detect the expressions of cell cycle, proliferation and migration related proteins. RESULTS: There was a high level expression of HDAC6 protein in laryngeal squamous cell carcinoma, and its expression was not related to age and sex of the patients (P > 0.05), but closely associated with the degree of histological differentiation, TNM staging and lymph node metastasis (P < 0.05). HDAC6 siRNA effectively down-regulated the expression of HDAC6 protein in laryngeal squamous cell carcinoma cell line Hep-2 cells, and downregulation of its expression obviously inhibited cell proliferation, arrested cell cycle at G(0)/G(1) phase and decreased cell migration ability in Hep-2 cells. Additionally, the downregulation of HDAC6 protein expression markedly decreased the expressions of cyclin D1, cyclin E, cdk2 and MMP-9 proteins, but increased the expressions of p21 and E-cadherin proteins. CONCLUSIONS: HDAC6 may play a pivotal role in the carcinogenesis and development of laryngeal squamous cell carcinoma. The downregulation of HDAC6 expression-mediated cell proliferation inhibition, cell cycle arrest and decreased cell migration ability may be closely associated with the decrease of cyclin D1, cyclin E, cdk2 and MMP-9 proteins and increase of p21 and E-cadherin proteins.
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Carcinoma de Células Escamosas/patología , Ciclo Celular , Movimiento Celular , Proliferación Celular , Histona Desacetilasas/metabolismo , Neoplasias Laríngeas/patología , Adulto , Anciano , Antígenos CD , Cadherinas/metabolismo , Carcinoma de Células Escamosas/genética , Carcinoma de Células Escamosas/metabolismo , Línea Celular Tumoral , Ciclina D1/metabolismo , Ciclina E/metabolismo , Quinasa 2 Dependiente de la Ciclina/metabolismo , Regulación hacia Abajo , Femenino , Histona Desacetilasa 6 , Histona Desacetilasas/genética , Humanos , Neoplasias Laríngeas/genética , Neoplasias Laríngeas/metabolismo , Metástasis Linfática , Masculino , Metaloproteinasa 9 de la Matriz/metabolismo , Persona de Mediana Edad , Estadificación de Neoplasias , Proteínas Oncogénicas/metabolismo , Proteínas Proto-Oncogénicas p21(ras)/metabolismo , ARN Interferente Pequeño/genética , TransfecciónRESUMEN
OBJECTIVE: To study the effect of histone deacetylation 6 (HDAC6) siRNA on the growth of xenografted human laryngeal squamous cell carcinoma cell line Hep-2 in nude mice and underlying mechanism. METHODS: Laryngeal squamous cell carcinoma cell line Hep-2 cells were subcutaneously injected to the back of nude mice and transplanted tumor model was established after one week. Nude mice was divided into three groups including blank control group, empty vector group and HDAC6 siRNA group, and the tumor growth was observed. Ki-67 proliferation index was detected by immunohistochemistry. Western blot, in situ hybridization and immunohistochemistry were used to detect the mRNA and protein expressions of HDAC6 in xenograft. The expressions of Bcl-2 and Bax proteins were examined by Western blotting. Cell apoptosis was detected by TUNEL. RESULTS: The mean volume of xenograft transfected with HDAC6 siRNA was less than that of xenograft transfected with empty vector or that of xenograft with blank control treatment (P < 0.05). HDAC6 siRNA effectively down-regulated the expressions of HDAC6 mRNA and the expressions of HDAC6 and Bcl-2 proteins, but up-regulated the expression of Bcl-2 protein in xenografts, with significant differences (all P < 0.05). The proliferation index of Ki-67 in HDAC6 siRNA transfection group was significantly lower than that in blank control group or empty vector group (P < 0.05). TUNEL assay demonstrated that HDAC6 evidently evoked cell apoptosis (P < 0.05). CONCLUSION: HDAC6 siRNA could effectively inhibited the growth of xenografted human laryngeal carcinoma cell line Hep-2 in nude mice, down-regulate the expressions of HDAC6 and bcl-2, and up-regulate the expression of bax.
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Histona Desacetilasas/metabolismo , Neoplasias Laríngeas/metabolismo , Animales , Línea Celular Tumoral , Regulación hacia Abajo , Femenino , Histona Desacetilasa 6 , Histona Desacetilasas/genética , Humanos , Neoplasias Laríngeas/patología , Ratones , Ratones Endogámicos BALB C , Ratones Desnudos , Proteínas Proto-Oncogénicas/metabolismo , Proteínas Proto-Oncogénicas c-bcl-2 , ARN Mensajero/genética , ARN Interferente Pequeño/genética , Transfección , Ensayos Antitumor por Modelo de Xenoinjerto , Proteína X Asociada a bcl-2/metabolismoRESUMEN
OBJECTIVE: To investigate the effects of histone deacetylase 2 (HDAC2) expression on cell proliferation, apoptosis and migration of laryngeal squamous cell carcinoma (LSCC) Hep-2 cells. METHODS: HDAC2 siRNA and control siRNA were transfected into LSCC Hep-2 cells by lipofectamine 2000, and cells were divided into three experimental groups: untreated group, control siRNA group and HDAC2 siRNA transfection group. Western blotting was utilized to detect the expression of HDAC2 protein in Hep-2 cells. Cell proliferation and apoptosis were investigated by CCK-8 kit and flow cytometry, respectively. Boyden chamber was used to study cell migration. Expressions of cell apoptosis and cell migration related proteins were detected by Western blotting. RESULTS: HDAC2 siRNA significantly down-regulated the expression of HDAC2 protein in LSCC Hep-2 cells. Down-regulation of HDAC2 expression coincided with an inhibition of cell proliferation and migration along with an induced cell apoptosis of Hep-2 cells. Moreover, down-regulation of HDAC2 expression significantly increased the expressions of caspase-3 and caspase-9 proteins but decreased the expressions of matrix metalloproteinases (MMP)-2 and MMP-9 proteins. CONCLUSIONS: HDAC2 may play a pivotal role in the initiation and development of LSCC. Down-regulation of HDAC2 expression mediates cell apoptosis. Cell migration inhibition may be tightly associated with overexpression of caspase-3 and caspase-9 along with down-regulation of MMP-2 and MMP-9 expressions.
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Apoptosis , Carcinoma de Células Escamosas/patología , Movimiento Celular , Proliferación Celular , Histona Desacetilasa 2/metabolismo , Neoplasias Laríngeas/patología , Carcinoma de Células Escamosas/metabolismo , Caspasa 3/metabolismo , Caspasa 9/metabolismo , Línea Celular Tumoral , Regulación hacia Abajo , Histona Desacetilasa 2/genética , Humanos , Neoplasias Laríngeas/metabolismo , Metaloproteinasa 2 de la Matriz/metabolismo , Metaloproteinasa 9 de la Matriz/metabolismo , Interferencia de ARN , ARN Interferente Pequeño/genética , TransfecciónRESUMEN
CONCLUSION: A recurrent neck abscess or acute suppurative thyroiditis should arouse suspicion of fourth branchial pouch sinus. Complete surgical excision is usually curative. The classification of sinus tract according to the area where it is emerging from the larynx may be helpful in identifying the tract during surgery. OBJECTIVE: To describe our experience of the diagnosis and management of fourth branchial pouch sinus and elucidate three different emerging pathways of the sinus tract during surgery. METHODS: Retrospective case series with eight patients who were diagnosed with fourth branchial pouch sinus between January 2007 and July 2011 at the First Affiliated Hospital of Zhengzhou University. RESULTS: Six patients presented with recurrent neck abscess, two presented with acute suppurative thyroiditis. All patients had barium swallow and sinus tract was delineated in six cases. All eight patients underwent surgical excision of the sinus tract. Three different emerging pathways of the sinus tract were identified during surgery. The tract could penetrate the thyroid cartilage near the inferior horn, the inferior pharyngeal constrictor muscle or the cricothyroid membrane when it emerged from the larynx. The recurrent laryngeal nerve was commonly dissected to avoid inadvertent damage. Hemithyroidectomy was performed in six patients. All eight are currently asymptomatic.
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Absceso/etiología , Región Branquial/anomalías , Branquioma/cirugía , Neoplasias de Cabeza y Cuello/cirugía , Procedimientos Quirúrgicos Otorrinolaringológicos/métodos , Tiroiditis/cirugía , Absceso/cirugía , Adolescente , Adulto , Región Branquial/diagnóstico por imagen , Región Branquial/cirugía , Branquioma/complicaciones , Branquioma/diagnóstico , Niño , Femenino , Estudios de Seguimiento , Neoplasias de Cabeza y Cuello/complicaciones , Neoplasias de Cabeza y Cuello/diagnóstico , Humanos , Imagen por Resonancia Magnética , Masculino , Estudios Retrospectivos , Tiroiditis/etiología , Tomografía Computarizada por Rayos X , Resultado del Tratamiento , Adulto JovenRESUMEN
OBJECTIVE: To observe the effects of small interfere RNA (siRNA) targeting the c-myc in combination with 5-fluorouracil (5-Fu) on the growth of Hep-2 cells in vitro and in vivo. METHODS: Hep-2 cells transfected with or without c-myc siRNA were treated with 5-Fu for 48 h. C-myc protein levels in Hep-2 cells were detected using the Western blot. The cell cycle was analyzed by flow cytometry. Hep-2 cells were subcutaneously inoculated into the back of BALB/c nude mice to establish the implanted laryngeal squamous carcinoma model. PBS, c-myc siRNA, and 5-Fu, alone or in combinations were administered i.p. The mice were sacrificed after the treatments and the tumor masses were removed to determine the tumor volume and weight. The inhibitory rate was calculated. Expression of c-myc in tumor tissue was detected by immunocytochemistry and cell apoptosis was analyzed by terminal transferase dUTP nick end labeling (TUNEL). RESULTS: The protein levels of c-myc decreased after transfected with c-myc siRNA. C-myc siRNA-transfected cells showed an increase in the percentage of cells in the GO-G1 phase and a decrease in the percentage of cells in the S phase. When combined with 5-Fu, the results were improved. The tumor growth was faster in the control group and was significantly slower in the c-myc siRNA plus 5-Fu group than that in the c-myc siRNA group or 5-Fu group (P < 0.05). The tumor weight in the c-myc siRNA plus 5-Fu group was significantly smaller than that in the c-myc siRNA or 5-Fu group (P < 0.05). Immunohistochemistry showed that c-myc siRNA inhibited the expression of c-myc in tumor tissues in the c-myc siRNA group and c-myc siRNA plus 5-Fu group (P < 0.05). The number of apoptotic cells in the c-myc siRNA plus 5-Fu group was higher than those in the c-myc siRNA groups (P < 0.05). CONCLUSIONS: C-myc siRNA inhibits the expression of c-myc in Hep-2 cells and in the tumor tissues of nude mice. C-myc siRNA combined with 5-Fu inhibits the growth of implanted laryngeal squamous carcinoma and promotes cell apoptosis. C-myc could become a novel target for the treatment of laryngeal squamous carcinoma.