Predicting the distribution of potentially suitable habitat in China for Cirsium japonicum Fisch. ex DC. under future climate scenarios based on the R-optimized MaxEnt model.

Cirsium japonicum contains a variety of medicinal components with good clinical efficacy. With the rapid changes in global climate, it is increasingly important to study the distribution of species habitats and the factors influencing their adaptability. Utilizing the MaxEnt model, we forecasted the present and future distribution regions of suitable habitats for C. japonicum under various climate scenarios. The outcome showed that under the current climate, the total suitable area of C. japonicum is 2,303,624 km2 and the highly suitable area is 79,117 km2. The distribution of C. japonicum is significantly influenced by key environmental factors such as temperature annual range, precipitation of the driest month, and precipitation of the wettest month. In light of future climate change, the suitable habitat for C. japonicum is anticipated to progressively relocate toward the western and northern regions, leading to an expansion in the total suitable area. These findings offer valuable insights into the conservation, sustainable utilization, and standardized cultivation of wild C. japonicum resources.

The ecological suitability area of Cirsium lineare (Thunb.) Sch.-Bip. under future climate change in China based on MaxEnt modeling.

Many kinds of medicinal ingredients occur in Cirsium lineare that have good clinical efficacy, conferring on this species its high medicinal development value. However, with a rapidly changing global climate, it is increasingly imperative to study the factors affecting the habitat distribution and survival of species. We predicted the current and future distribution areas of suitable habitats for C. lineare, analyzed the importance of environmental variables in influencing habitat shifts, and described the alterations to suitable habitats of C. lineare in different periods (modern, 2050s, and 2070s) and scenarios (RCP2.6, RCP4.5, and RCP8.5). The results show that, under the current climate, the total suitable area of C. lineare is about 2,220,900 km2, of which the highly suitable portion amounts to ca. 292,600 km2. The minimum temperature of the coldest month, annual precipitation, and mean daily temperature range are the chief environmental variables affecting the distribution of habitat for C. lineare. In the same period, with rising greenhouse gas emission concentrations, the total suitable area will increase. In general, under future climate change, the suitable habitat for C. lineare will gradually migrate to the west and north, and its total suitable area will also expand. The results of this experiment can be used for the conservation and management of the wild resources of C. lineare. We can choose suitable growth areas to protect the medicinal resources of C. lineare through in situ conservation and artificial breeding.

circRNA_0006393 promotes osteogenesis in glucocorticoid­induced osteoporosis by sponging miR­145­5p and upregulating FOXO1.

Glucocorticoids are the most common cause of glucocorticoid­induced osteoporosis (GIOP). Moreover, the role of circular RNAs (circRNAs) in the regulation of bone metabolism remains unclear. Therefore, in the present study, it was hypothesized that hsa_circ_0006393 may play an important role in GIOP. To investigate the role of circRNAs in GIOP, treatment with dexamethasone or transfection with a vector overexpressing hsa_circ_0006393 were performed using in vitro cell and in vivo mouse models. Reverse transcription­quantitative PCR, fluorescence in situ hybridization and western blotting were performed to investigate the function of hsa_circ_0006393 in vitro. In addition, the effects of hsa_circ_0006393 on osteogenesis were investigated. Dual­energy X­ray absorptiometry analysis was performed to examine the osteogenic potential of hsa_circ_0006393 in vivo. Moreover, the mechanism underlying hsa_circ_0006393­mediated bone metabolism regulation via the microRNA (miR)­145­5p/forkhead box O1 (FOXO1) pathway was investigated. The present results suggested that the expression level of hsa_circ_0006393 was decreased in patients with GIOP. Furthermore, the overexpression of hsa_circ_0006393 increased the expression level of genes associated with osteogenesis. Moreover, hsa_circ_0006393 was identified to be localized mainly in the cytoplasm and nucleus of bone marrow mesenchymal stem cells. miR­145­5p was found to be directly targeted by hsa_circ_0006393. Collectively, hsa_circ_0006393 increases the expression levels of osteogenic genes during bone remodeling by sponging miR­145­5p and upregulating FOXO1.

[Cloning and characterization of chalcone synthase and chalcone isomerase genes in Arisaema heterophyllum].

Chalcone synthase( CHS) and chalcone isomerase( CHI) are key enzymes in the biosynthesis pathway of flavonoids. In this study,unigenes for CHS and CHI were screened from the transcriptome database of Arisaema heterophyllum. The open reading frame( ORFs) of chalcone synthase( Ah CHS) and chalcone isomerase( Ah CHI) were cloned from the plant by RT-PCR. The physicochemical properties,expression and structure characteristics of the encoded proteins Ah CHS and Ah CHI were analyzed. The ORFs of Ah CHS and Ah CHI were 1 176,630 bp in length and encoded 392,209 amino acids,respectively. Ah CHS functioned as a symmetric homodimer. The N-terminal helix of one monomer entwined with the corresponding helix of another monomer. Each CHS monomer consisted of two structural domains. In particular,four conserved residues define the active site. The tertiary structure of Ah CHI revealed a novel open-faced ß-sandwich fold. A large ß-sheet( ß4-ß11) and a layer of α-helices( α1-α7) comprised the core structure. The residues spanning ß4,ß5,α4,and α6 in the three-dimensional structure were conserved among CHIs from different species. Notably,these structural elements formed the active site on the protein surface,and the topology of the active-site cleft defined the stereochemistry of the cyclization reaction. The homology comparison showed that Ah CHS had the highest similarity to the CHS of Anthurium andraeanum,while Ah CHI had the highest similarity to the CHI of Paeonia delavayi. This study provided the basis for the functional study of Ah CHS and Ah CHI and the further study on plant flavonoid biosynthesis pathway.

LSPR-based cholesterol biosensor using a tapered optical fiber structure.

Accurate cholesterol level measurement plays an important role in the diagnosis of severe diseases such as cardiovascular diseases, hypertension, anemia, myxedemia, hyperthyroidism, coronary artery illness. Traditionally, electrochemical sensors have been employed to detect the cholesterol level. However, these sensors have limitations in terms of sensitivity and selectivity. In this paper, a localized surface plasmon resonance (LSPR) -based biosensor is demonstrated that accurately detects and measures the concentration of cholesterol. In the present study, a tapered optical fiber-based sensor probe is developed using gold nanoparticles (AuNPs) and cholesterol oxidase (ChOx) to increase the sensitivity and selectivity of the sensor. Synthesized AuNPs were characterized by UV-visible spectrophotometer, transmission electron microscope (TEM), and energy dispersive X-ray spectroscopy (EDS). Further, coating of AuNPs over fiber was confirmed by scanning electron microscope (SEM). The developed sensor demonstrates for a clinically important cholesterol range of 0 to 10 mM, and the limit of detection is found to be 53.1 nM.

An integrated approach for remanufacturing job shop scheduling with routing alternatives.

Remanufacturing is a practice of growing importance due to increasing environmental awareness and regulations. However, the stochastic natures inherent in the remanufacturing processes complicate its scheduling. This paper undertakes the challenge and presents a remanufacturing job shop scheduling approach by integrating alternative routing assignment and machine resource dispatching. A colored timed Petri net is introduced to model the dynamics of remanufacturing process, such as various process routings, uncertain operation times for cores, and machine resource conflicts. With the color attributes in Petri nets, two types of decision points, recovery routing selection and resource dispatching, are introduced and linked with places in CTPN model. With time attributes in Petri nets, the temporal aspect of recovery operations for cores as well as the evolution dynamics in cores' operational stages is mathematically analyzed. A hybrid meta-heuristic algorithm embedded scheduling strategy over CTPN is proposed to search for the optimal recovery routings for worn cores and their recovery operation sequences on workstations, in minimizing the total production cost. The approach is demonstrated through the remanufacturing of used machine tool and its effectiveness is compared against another two cases: baseline case with fixed recovery process routings and case 2 using standard SA/MST.

[Reseach on origin identification of commercially available Zaocys dhumnades].

Through market investigation, the adulteration of Zaocys dhumnades on markets was found out, and samples of authentic and adulterated Z. dhumnades on markets were collected. The origin and properties of the adulterated Z. dhumnades were studied in order to provide reference for the identification of Z. dhumnades. The counterfeit Z. dhumnades sold on markets were as follows: Ptyas korros, P. mucosus, Najanaja atra, Sinonatrix annularis, Dinodon septentrionalis, etc. It is found that there existed a obvious difference between the traits of the Z. dhumnades and counterfeits. Genuine Z. dhumnades with "sword ridge" "iron tail", strongly ribbed scales and other features, is the key point to identify the difference from adulterants.

Long noncoding RNA LINC00483/microRNA-144 regulates radiosensitivity and epithelial-mesenchymal transition in lung adenocarcinoma by interacting with HOXA10.

Lung adenocarcinoma (LAD) is the leading cause of cancer death worldwide. Long noncoding RNAs (lncRNAs) have been shown to play an important regulatory role in cancer biology, including that of LAD. The aim of this experiment was to explore the interaction of LINC00483, microRNA-144 (miR-144), and homeobox A10 (HOXA10), and their effects on radio sensitivity and epithelial-mesenchymal transition (EMT) of LAD. Initially, microarray analysis was used to screen out miRNAs and lncRNAs, as well as the differentially expressed genes related to LAD. Following the screening process, the targeting relationship of LINC00483, miR-144, and that of miR-144 and HOXA10 was determined. Following that, the expression of LINC00483, miR-144, messenger RNA (mRNA), as well as protein expression of HOXA10, MMP-2, MMP-9, E-cadherin, vimentin, and N-cadherin that followed in cells was determined. Also, the effect of LINC00483 on cell migration and invasion ability, and cell tumorigenic ability was detected. LINC00483 and HOXA10 were found to be upregulated whereas miR-144 was downregulated in LAD. Silencing of LINC00483 could competitively bind to miR-144, thereby upregulating HOXA10. LINC00483 or HOXA10 silencing led to decreased HOXA10, MMP-2, MMP-9, vimentin, and N-cadherin but elevated miR-144 and E-cadherin. Moreover, after being transfected with silenced LINC00483, the cell proliferation, migration, and invasion were inhibited with enhanced radiosensitivity. Consequently, the data of the study indicates that interference of LINC00483 weakens its competitive binding ability to miR-144, thus reducing HOXA10 expression, and enhancing radiosensitivity in LAD.

Downregulated expression of microRNA-329 inhibits apoptosis of nigral dopaminergic neurons by regulating CDKN2D expression via the FoxO3a signaling pathway in rats with Parkinson's disease.

Parkinson's disease (PD) is a common neurodegenerative disorder due to the loss of dopaminergic neurons in the substantia nigra. This study focuses on the effect of microRNA-329 (miR-329) on nigral dopaminergic neurons in a rat model of PD via the FoxO3a signaling pathway by binding to CDKN2D. Brain tissues from the substantia nigra were taken from the rats in two groups. TUNEL staining was used to observe tyrosine hydroxylase (TH)-positive neurons. Nigral dopaminergic neurons were randomized into the normal, blank, negative control (NC), miR-329 mimics, miR-329 inhibitors, small interfering (siRNA)-CDKN2D, and miR-329 inhibitors + siRNA-CDKN2D groups. Expressions of miR-329, CDKN2D, FoxO3a, AKT, caspase-3 and Bcl-2 were determined using RT-qPCR and western blotting. Apoptosis rate of nigral dopaminergic neurons in 7 groups was determined by flow cytometry. Compared with the blank and NC groups, the miR-329 mimics group showed increased miR-329 and caspase-3 expressions as well as decreased expressions of CDKN2D, FoxO3a, AKT, and Bcl-2, the siRNA-CDKN2D group indicated enhanced expressions of caspase-3 and declined expressions of CDKN2D, FoxO3a, AKT, and Bcl-2, and the miR-329 inhibitors group revealed decreased miR-329 and caspase-3 expressions and increased expressions of CDKN2D, FoxO3a, AKT, and Bcl-2. The apoptosis rate of nigral dopaminergic neurons was significantly increased in the miR-329 mimics and siRNA-CDKN2D groups, but was decreased in the miR-329 inhibitors group. Our data suggested that downregulated miR-329 could inhibit apoptosis of nigral dopaminergic neurons in a rat model of PD by upregulating the expression of CDKN2D via the activation of the FoxO3a signaling pathway.

[Chemical constituents from fresh tubers of Dioscorea bulbifera].

Eighteen compounds were isolated from the 95% ethanol extract of fresh tubers of Dioscorea bulbifera by column chromatography over silica gel,Sephadex LH-20, and ODS. Their structures were elucidated by spectroscopic data analysis as 6-hydroxy-2,10,10-trimethoxy-anthracen-9-one(1), diosgenin (2), stigmasterol(3), 3, 7-dimethoxy-5, 3', 4'-trihydroxyflavone(4), 2, 7-dihydroxy-3, 4-dimethoxyphenanthrene(5), 3, 7-dihydroxy-2, 4-dimethoxy phenanthrene(6), 2, 7-dihydroxy-4-methoxyphenanthrene (7), 2, 7-dihydroxy-3, 4-dimethoxy-9, 10-dihydroxy phenanthrene(8), azelaic acid (9), 8-epidiosbulbin E acetate (10), 1, 7-bis-(4-hydroxyphenyl)-4E, 6E-heptadien-3-one(11), diosbulbin B(12), pentacosanoic acid 2', 3'-dihydroxypropyl ester(13), 2, 7-dihydroxy-4-methoxy-9, 10-dihydroxy-phenanthrene (14), 1, 7-bis-(4-hydroxyphenyl)-1E, 4E, 6E-heptatrien-3-one (15), 6-ethoxy-1H-pyrimidine-2, 4-dione (16), 3, 5, 4'-trihydroxy-bibenzyl (17), and diosbulbin F (18). Compound 1 is a new compound, and compounds 7, 9, 13, and 16 were isolated from this plant for the first time.

[Evolution and transition of source of Patrinia Herba and Patrinia Radix].

Both Patrinia Herba and Patrinia Radix are traditional Chinese herbal medicines. The herbal source and medicinal part of them are confusing in the herbal medicine market of China. To explore the evolution and transition of the herbal source and medicinal part of Patrinia Herba and Patrinia Radix, this paper systematically summarizes the record of the herbal source and medicinal part of them in ancient classics of herbal medicine in China. According to the findings, before Ming Dynasty, Patrinia Herba originated from the radix of the plants with yellow flowers of Patrinia. In Ming and Qing Dynasty, Patrinia Herba originates from the whole plant (including the radix)of the plant with white flowers of Patrinia. In Ming Dynasty, Patrinia Radix, stemming from the radix of the plants with yellow flowers of Patrinia, started to be used as a traditional Chinese herbal medicine, which had the same herbal source with that of Patrinia Herba before Ming Dynasty. Therefore, Patrinia Herba and Patrinia Radix can be seen as the same traditional Chinese herbal medicine, and the genuine of Patrinia Herba should be the radix and the whole herba of P. scabiosaefolia and P. heterophylla.

Nepetaefolins A-J, Cytotoxic Chinane and Abietane Diterpenoids from Caryopteris nepetaefolia.

Nepetaefolins A-J (1-10) and seven known compounds were isolated from the whole plant of Caryopteris nepetaefolia. The absolute configurations of 1-3 were determined from single-crystal X-ray diffraction and spectroscopic data. Compounds 6 and 7, with IC50 values of 6.3-9.0 µM, showed higher cytotoxicity than paclitaxel in one non-small-cell lung cancer, patient-derived xenograft (PDX) model when tested using PDX models and the adenosine triphosphate-tumor chemosensitivity assay (ATP-TCA).

Up-Regulation of MicroRNA-133a Inhibits the MEK/ERK Signaling Pathway to Promote Cell Apoptosis and Enhance Radio-Sensitivity by Targeting EGFR in Esophageal Cancer In Vivo and In Vitro.

This study aims to explore how microRNA-133a (miR-133a) affects cell apoptosis and radio-sensitivity by targeting EGFR via regulating MEK/ERK pathway in esophageal cancer (EC). A total of 358 EC patients were selected and assigned into the resistant and sensitive groups. Human EC KYSE 150 cell line was assigned into the blank, negative control (NC), miR-133a mimic, miR-133a inhibitors, si-EGFR, miR-133a inhibitors + si-EGFR groups after transfection. MiR-133a and EGFR mRNA expressions were detected by qRT-PCR and EGFR, MEK/ERK pathway-related protein expressions were detected by Western blotting. The radio-sensitivity and cell apoptosis were testified by clone formation and flow cytometry. MiR-133a was up-regulated but EGFR was down-regulated in the sensitive group than in the resistant group. Compared with the blank and NC groups, the miR-133a mimic and si-EGFR groups exhibited increased cell apoptosis rate but decreased EGFR, p-MEK1/2, and p-ERK1/2 protein expressions; while opposite trend was observed in the miR-133a inhibitors group. Compared with the miR-133a inhibitors group, the miR-133a inhibitors + si-EGFR group presented reduced cell survival rate, EGFR, p-MEK1/2, and p-ERK1/2 protein expressions but increased cell apoptosis rate. These results indicated that miR-133a could inhibit the MEK/ERK pathway to promote cell apoptosis and enhance radio-sensitivity by targeting EGFR in EC. J. Cell. Biochem. 118: 2625-2634, 2017. © 2017 Wiley Periodicals, Inc.

Abietane diterpenoids from Caryopteris incana (Thunb.) Miq.

Twelve new diterpenes, caryopincaolide A-L (1-4, 11-12, 16-19, 27-28), together with twenty-eight known diterpenes, have been isolated from the whole plant of Caryopteris incana (Thunb.) Miq. Their structures were elucidated on the basis of 1D and 2D NMR, IR, X-ray crystal diffraction and mass spectroscopic data, as well as ECD calculations. All compounds were tested for in vitro dipeptidyl peptidase IV (DPP-IV) inhibitory activity, with compounds 3, 4, 28, 29, and 40 exhibiting DPP-IV inhibitory effects with IC50 values ranging from 54.2 to 228.9 µM. Compounds 1, 3 and 4 also showed potent activity toward the inhibition of the growth of human cancer cells and 1 can induce apoptosis in Hey and A-549 cells.

[Cloning and expression analysis of 1-deoxy-D-xylulose-5-phosphate reductoisomerase gene (CcDXR1) in Cinnamomum camphora L.) Presl].

1-Deoxy-D-xylulose-5-phosphate reductoisomerase (DXR) is the second rate-limiting enzyme of terpenoid biosynthesis in the methylerythritol-4-phosphate pathway. According to the transcriptome database of Cinnamomum camphora, the DXR cDNA was cloned by rapid amplification of cDNA ends (RACE) from C. camphora, and was named CcDXR1(GenBank number: KU886266). The ORF of CcDXR1 is composed of 1 413 bp, and it encodes 470 amino acids. The bioinformatics analysis suggests that the molecular weight of the encoded protein is 51.1 kD and the theoretically isoelectric point is 6.62, and there is no signal peptide and transmembrane structure in putative protein. The analysis of sequence alignment and phylogenetic tree showed that the CcDXR1 belonged to the DXR family. The results of the realtime PCR indicated that expression level of CcDXR1 in mature leaves was higher than tender leaves, which in roots was similar to leaves and the lowest in branches. The camphor is divided into five chemotypes, according to the main chemical compounds in C. camphora. It also showed that the expression level of CcDXR1 in borneol C. camphora was highest than that in cineol, iso-nerolidol, camphor and linalool. Our results revealed that the expression level of CcDXR1 exhibits diversity among plant tissues, growth periods and five chemical types, and the research provides foundation for further study of the terpenoids biosynthetic pathway in C. camphora.

[Development of rapid setting-drying device for herbarium specimens and its application in survey of Chinese materia medica resources in Anhui].

Herbarium specimens are the basis for the plant classification and indispensable media in teaching, scientific research and resources investigation. They have also played an important role in identifying and producing traditional Chinese medicine. High-quality herbarium specimens shall meet high requirements for integrity, smoothness, color and fabricating efficiency. Therefore, we designed a rapid setting and drying device for herbarium specimens, which could make the herbarium specimens smooth, colorful and not easy to mildew. In this paper, we pointed out the deficiency of traditional methods in making herbarium specimens, and introduced the structure and working principle of the device. Besides, we also discussed the effect of the device in setting and drying herbarium specimens and its application in the fourth national survey of the Chinese material medica resources (CMMR) in Anhui province. As a result, the device provides new ideas for producing herbarium specimens, with a reasonable design, good uniformity, high efficiency, safety and portability, and so is worthy of promotion and application in the national survey of CMMR.

Fluid-structure interaction analysis of pulsatile flow within a layered and stenotic aorta.

In this paper, the hemodynamic characteristics of blood flow and stress distribution in a layered and stenotic aorta are investigated. By introducing symmetrical and unsymmetrical stenosis, the influence of stenosis morphology and stenotic ratio on the coupled dynamic responses of aorta is clarified. In the analysis, the in-vivo pulsatile waveforms and fully fluid-structure interaction (FSI) between the layered elastic aorta and the blood are considered. The results show that the fluid domain is abnormal in the stenotic aorta, and the whirlpool forms at the obstructed and downstream unobstructed regions. The maximum wall shear stresses appear at the throat of the stenosis. Downstream region appears low and oscillated shear stresses. In addition, along with the increase of the stenotic ratio, the amplitude of the maximum shear stress will be intensively increased and localized, and the sensitivity is also increased. In the aorta with unsymmetrical stenosis, the Von Mises stresses reach the peak value at the side with the surface protuberance, but they are reduced at the side with no protuberance. The sign variation of the layer interface shear stresses near the throat indicates the variation of the shear direction which increases the opportunity of shear damage at the transition plane. Moreover, the shear stress levels at the fluid-solid and intima-media interfaces are higher than that at the media-adventitia interface. The unsymmetrical stenosis causes higher stresses at the side with the surface protuberance than symmetrical one, but lower at the side with no protuberance. These results provide an insight in the influence of the stenosis, as well as its morphology, on the pathogenesis and pathological evolution of some diseases, such as arteriosclerosis and aortic dissection.

[Resources investigation of medicinal plants of Huangfu mountain in city of Chuzhou based on grid sampling method].

OBJECTIVE: To conduct preliminary investigation to the species and reserves of medicinal plants in Huangfu Mountain, and to provide references to the general survey of those plants for medicine. METHOD: Combined with global positioning system (GPS), the program of investigation with grid sampling was used in this resource survey of medicinal plants. RESULT: After the preliminary investigation of the plants for medical use of Huangfu Mountain, it is found that there are 103 families with 313 kinds of plants. There are many medicinal plants and large distribution, such as Pseudostellaria heterophylla, Semiaguilegia adoxoides and Pinellia ternate. CONCLUSION: Huangfu Mount, with so many different kinds of medicinal plants and comfortable environment for part of the medicinal plants to grow, could be developed as a base for planting Chinese herbal medicines.

Methotrexate-mediated inhibition of RAD51 expression and homologous recombination in cancer cells.

BACKGROUND: Methotrexate is an inhibitor of folic acid metabolism. Homologous recombination is one of the most important ways to repair double-stranded breaks in DNA and influence the radio- and chemosensitivity of tumor cells. But the relationship between methotrexate and homologous recombination repair has not been elucidated. METHODS: Induction of double-strand breaks by methotrexate in HOS cells is assessed by the neutral comet assay. Inhibition of subnuclear repair foci by methotrexate is measured by immunofluorescence. Western blot and quantitative real-time PCR are conducted to detect whether methotrexate affects the expression level of genes involved in homologous recombination. In addition, we used a pCMV3xnls-I-SceI construct to determine whether methotrexate directly inhibits the process of homologous recombinational repair in cells, and the sensitivity to methotrexate in the Ku80-deficient cells is detected using clonogenic survival assays. RESULTS: The result showed that methotrexate can regulate the repair of DNA double-strand breaks after radiation exposure, and methotrexate inhibition caused the complete inhibition of subnuclear repair foci in response to ionizing radiation. Mechanistic investigation revealed that methotrexate led to a significant reduction in the transcription of RAD51 genes. Treatment with methotrexate resulted in a decreased ability to perform homology-directed repair of I-SceI-induced chromosome breaks. In addition, enhancement of cell death was observed in Ku mutant cells compared to wild-type cells. CONCLUSIONS: These results demonstrate that methotrexate can affect homologous recombination repair of DNA double-strand breaks by controlling the expression of homologous recombination-related genes and suppressing the proper assembly of homologous recombination-directed subnuclear foci.

ShRNA-mediated Ku80 gene silencing inhibits cell proliferation and sensitizes to gamma-radiation and mitomycin C-induced apoptosis in esophageal squamous cell carcinoma lines.

To investigate the effects of Ku80 depletion on cell growth and sensitization to gamma-radiation and MMC-induced apoptosis in esophageal squamous cell carcinoma lines. Six human carcinoma cell lines (LNcaP, K562, MDA-MB-231, MCF-7, EC9706, and K150) and normal HEK293 cell line were examined for basal levels of Ku80 protein by western blotting analysis. The suppression of Ku80 expression was performed using vector-based shRNA in EC9706 cells. Cell proliferation was determined with MTT assay and colony formation assay and tumorigenicity in a xenograft model in vitro and in vivo. Sensitivity of EC9706 cells treated with shRNA vector to gamma-radiation and MMC was determined with colony formation assay and MTT assay. The cell cycle distribution was determined by Flow cytometry. Apoptosis induced by gamma-radiation and MMC was analyzed using GENMED-TUNEL FACS kit. Ku80 showed higher basal levels in six carcinoma cell lines than in HEK293. The suppression of Ku80 expression decreased cellular proliferation, colony formation and inhibited tumorigenicity in a xenograft model. Furthermore, it sensitized apoptosis of the cancer cells induced by gamma-radiation and MMC. Ku80 plays an important role not only in tumorigenesis but also in radiation resistance and chemotherapy resistance in esophageal cancer cells. Hence Ku80 may serve as a promising therapeutic target, particularly for recurrent esophageal tumors.