Biomimetic Bacterial Capsule for Enhanced Aptamer Display and Cell Recognition.

Great effort has been made to encapsulate or coat living mammalian cells for a variety of applications ranging from diabetes treatment to three-dimensional printing. However, no study has reported the synthesis of a biomimetic bacterial capsule to display high-affinity aptamers on the cell surface for enhanced cell recognition. Therefore, we synthesized an ultrathin alginate-polylysine coating to display aptamers on the surface of living cells with natural killer (NK) cells as a model. The results show that this coating-mediated aptamer display is more stable than direct cholesterol insertion into the lipid bilayer. The half-life of the aptamer on the cell surface can be increased from less than 1.5 to over 20 h. NK cells coated with the biomimetic bacterial capsule exhibit a high efficiency in recognizing and killing target cells. Therefore, this work has demonstrated a promising cell coating method for the display of aptamers for enhanced cell recognition.

Complete genome sequence of a novel alternavirus isolated from the phytopathogenic fungus Colletotrichum fioriniae.

A novel double-strand RNA (dsRNA) mycovirus, named "Colletotrichum fioriniae alternavirus1" (CfAV1), was isolated from the strain CX7 of Colletotrichum fioriniae, the causal agent of walnut anthracnose. The complete genome of CfAV1 is composed of three dsRNA segments: dsRNA1 (3528 bp), dsRNA2 (2485 bp), and dsRNA3 (2481 bp). The RNA-dependent RNA polymerase (RdRp) is encoded by dsRNA1, while both dsRNA2 and dsRNA3 encode hypothetical proteins. Based on multiple sequence alignments and phylogenetic analysis, CfAV1 is identified as a new member of the family Alternaviridae. This is the first report of an alternavirus that infects the phytopathogenic fungus C. fioriniae.

First report of Colletotrichum fioriniae Causing Anthracnose Disease of Rhus chinensis in China.

Rhus chinensis, a tree of major economic importance in China, belongs to the Anacardiaceae. It is the summer host of the aphid Melaphis chinensis which produces a leaf gall utilized for medicinal purposes (Li et al. 2022). In August 2021 and June 2022, dark brown spots were observed on young branches of R. chinensis in Wufeng, Hubei province, China. The plantations of R. chinensis in Wufeng County had different degrees of disease. We focused our survey on three plantations, each with an area of 1.5 hectares and 1600 R. chinensis plants per hectare, and the incidence of the disease was found to be around 70%. Symptoms began as small brown spots that expanded with time and eventually led to large, irregular, dark brown and sunken lesions. Under high temperature and humidity, orange conidiomata appeared on top of the lesions. As the disease progressed, branches rotted, broke, and leaves died and dropped, eventually causing the death of trees. The fungus was isolated from infected branches. Branch pieces were cut and surface disinfested in 75% (v/v) alcohol for 30 sec, then sterilized in 4% sodium hypochlorite for 1 min, and washed three times with sterile distilled water before incubated on potato dextrose agar (PDA) at 25℃.Ten isolates were obtained by a single-spore culturing method, considering HTK-3 isolate showed more pathogenic and grew faster than other isolates, it was selected for further research. After culturing for 7 days on PDA medium, the colony of isolate HTK-3 was cottony with white-to-gray aerial mycelium. The mycelial growth rate was 8.7 mm/day at 25℃. Conidia were single-celled, colorless, smooth-walled, fusiform with acute ends, and measured 7.7 to 14.3 × 3.2 to 5.3µm (mean 11.8 ± 1.3 to 4.2 ± 0.5µm, n = 50). Appressoria were single, medium brown, ovate to ellipsoid, 5.8 to 8.5× 3.7 to 6.1µm (mean 7.2 ± 0.7 × 4.9 ± 0.4 µm, n=50). Microscopic examinations showed conidia of the HTK-3 were hyaline, aseptate, and sub-cylindrical, with obtuse apices and tapering bases. Mycelium of which was hyaline, branched and septate. Based on these morphological features, the fungus was tentatively identified as belonging to Colletotrichum acutatum species complex (Damm et al. 2012). For molecular identification, the ITS region, glyceraldehyde-3-phosphate dehydrogenase (GAPDH), chitin synthase (CHS-1), beta-tubulin 2 (TUB2), and actin (ACT) were amplified and sequenced (Liu et al., 2022). The obtained sequences were deposited into the GenBank [accession numbers: OP630818 (ITS); OP649736 (GAPDH); OP649735 (TUB2); OP649738 (CHS-1); OP649737 (ACT)]. For all of these genes, isolates HTK-3 had a 99-100% similarity to multiple C. fioriniae accessions. A maximum likelihood tree was generated from a multiple sequence alignment of reported isolates (Liu et al. 2022) and HTK-3 was identified as C. fioriniae. To fulfill Koch's postulates, ten healthy branches were inoculated with 5-mm-diameter mycelial plugs of each of ten fungal isolates (Wang et al., 2022). PDAs plug without mycelium was used as control. Six days post-inoculation, all branches developed anthracnose symptoms similar to those observed in the field, while the control remained healthy. The pathogenicity tests were repeated twice with the same results. C. fioriniae was re-isolated from the disease branches and the morphology was consistent with original, fulfilling Koch's postulates. The species of C. fioriniae has been reported to cause severe anthracnose of many species of plants (Eaton et al. 2021). To our knowledge, this is the first report of C. fioriniae as a pathogen of R. chinensis in China. The results will help to target the screening of control agents and provide guidance for disease prevention and control.

Molecular characterization of a novel penoulivirus from the phytopathogenic fungus Colletotrichum camelliae.

Colletotrichum camelliae is a widespread filamentous phytopathogenic fungus. In this study, a novel mycovirus designated as "Colletotrichum camelliae botourmiavirus 1" (CcBV1) was isolated from strain ZJQT11 of C. camelliae, and its complete genome sequence was determined. CcBV1 has a genome of 2,506 nucleotides and contains a large open reading frame (ORF) that encodes an RNA-dependent RNA polymerase (RdRp) with 672 amino acids and a predicted molecular mass of 75.23 kDa. A BLASTp search showed that RdRp encoded by CcBV1 is closely related to that of Pyricularia oryzae ourmia-like virus 1 with 73.22% identity. Phylogenetic analysis indicated that CcBV1 clustered in the penoulivirus clade within the family Botourmiaviridae. To the best of our knowledge, this is the first report of a penoulivirus in C. camelliae.

First Report of Colletotrichum nymphaeae Causing Walnut Anthracnose in China.

Walnut (Juglans regia L.) is a high quality woody nut and edible oil tree with a planting area of about 5,000,000 hectare in China. Walnut anthracnose is a serious disease, infecting approximately 50% of the fruits and causing a great yield losses (Wang et al. 2016). In 2019 to 2020, walnut fruits with anthracnose symptoms were collected from walnut orchards in province of Hubei, Sichuan procinve and Chongqing municipality, China. Symptoms on fruits were circular or subcircular or irregular shaped, with brown to black water soaked and sunken lesions. The black lesions enlarged and amalgamated into large necrotic areas. The older spots in the center became blackish with acervuli causing the complete mummification of the fruit, and orange conidial masses appeared under wet conditions. Necrotic tissues of the fruits were sterilized in 75% ethanol solution for 30 s, then sterilized in 4% sodium hypochlorite for 1min, and washed 3 times with sterile distilled water. The tissues were put on potato dextrose agar (PDA) and incubated at 25℃. Pure cultures were obtained by single-spore culturing method and the isolate HBBK4-4 was deposited into the China's Forestry Culture Collection Center (CFCC 57388). On PDA, the colonies were cottony, white to pale gray with aerial mycelium on the upper side and pink with black spots on the reverse. The mycelial growth rate was 9.6 mm/day at 25°C. Conidia were 1-celled, colorless, smooth-walled, straight, cylindrical to cylindrical-clavate with acute ends, 12.5 to 18.2 × 3.9 to 5.4 µm (mean 15.3 ± 3.7 × 4.9 ± 0.6 µm, n = 40). Most conidia germinated and developed one pleurogenous, 1-celled appressorium. Appressoria were single, medium brown, smooth-walled, ovate to ellipsoid, 5.4 to 7.8 × 5.4 to 7.8 µm (mean 6.7 ± 0.6 × 6.3 ± 0.5 µm, n = 30). These morphological characteristics were in concordance with published descriptions of Collectotrichum acutatum species complex. To further confirm the identity, internal transcribed spacer (ITS), beta-tubulin (TUB2), chitin synthase 1 (CHS-I) and glyceraldehyde-3-phosphate dehydrogenase (GAPDH) genes were amplified and sequenced (Damm et al. 2012). The ITS (OM189549) and TUB2 (OM273642) sequences of isolate HBBK4-4 showed 100% similarity, and GAPDH (OM249791) and CHS-1 (OM273641) sequences showed 98.7% and 99.6% similarity with C. nymphaeae CBS100064 respectively. A maximum likelihood phylogenetic tree was generated based on combining all sequenced loci in MEGA5. 18 isolates including HBBK4-4 fell in the C. nymphaeae clade with 96% bootstrap support. To verify Koch's postulates, six isolates were used for pathogenicity test, and 20 healthy fruits and 15 fully expanded leaves for each isolate were inoculated with 5-mm-diameter mycelial plugs. Controls consisted of detached premature fruits inoculated with a PDA plug without the fungus. Six days after inoculation, all fruits and leaves developed anthracnose symptoms similar to those observed in the field, while the controls remained healthy. The pathogenicity tests were repeated twice with the same results. The morphology of the reisolated fungi was consistent with the inoculated one, fulfilling Koch's postulates. The isolate HBBK4-4 was identified as C. nymphaeae, based on the description by Damm et al. (2012). The species C. nymphaeae has been previously reported to cause severe anthracnose on walnut in France (Da Lio et al., 2018), Brazil (Savian et al., 2019) and Italy (Luongo et al., 2022). To our knowledge, this is the first report of C. nymphaeae as a pathogen of walnut anthracnose in China. The result provided crucial information for epidemiologic studies and management of this disease.

Identification and Characterization of Colletotrichum Species Associated with Anthracnose Disease of Camellia oleifera in China.

Tea-oil tree (Camellia oleifera Abel) is an important edible oil woody plant with a planting area over 3,800,000 hectares in southern China. Anthracnose is a serious disease of tea-oil tree in southern China, causing severe economic losses and posing a huge threat to the Ca. oleifera industry. Based on recent developments in the classification of Colletotrichum species, the objective of this study was to identify Colletotrichum species associated with tea-oil tree and examine their pathogenicity on leaves and fruits of Ca. oleifera. In total, 232 isolates were obtained from Ca. oleifera leaves and fruits with anthracnose symptoms. These isolates were further characterized based on morphology and multilocus phylogenetic analyses using partial DNA sequences at the ribosomal internal transcribed spacer regions and ß-tubulin, actin, calmodulin, glyceraldehyde-3-phosphate dehydrogenase, and chitin synthase-encoding genes. The fungal isolates belong to five species: C. camelliae, C. fructicola, C. siamense, C. aenigma, and C. gloeosporioides. C. camelliae was the most predominant and widely distributed species on fruits of Ca. oleifera (91.4%), followed by C. fructicola (6.3%). However, C. fructicola was common and widely distributed species on leaves (75.9%), followed by C. camelliae (17.2%). There was no evidence of geographical specialization of the different species. Pathogenicity assays showed that all tested isolates, including 20 of C. camelliae, 11 of C. fructicola, four of C. siamense, two of C. aenigma, and one of C. gloeosporioides, were pathogenic to leaves and fruits of Ca. oleifera. Among the five species, C. camelliae species showed strong pathogenicity on both leaves and fruits of Ca. oleifera, and C. fructicola, C. siamense, C. aenigma, and C. gloeosporioides all showed weak pathogenicity on both leaves and fruits. No relationship was found between origin of isolates and their virulence. This is the first description of C. camelliae, C. fructicola, C. siamense, and C. gloeosporioides from the fruits of Ca. oleifera in China.

Display of Polyvalent Hybrid Antibodies on the Cell Surface for Enhanced Cell Recognition.

Cell surface engineering with exogeneous receptors holds great promise for various applications. However, current biological methods face problems with safety, antigen escape, and receptor stoichiometry. The purpose of this study is to develop a biochemical method for displaying polyvalent antibodies (PAbs) on the cell surface. The PAbs are synthesized through the self-assembly of DNA-Ab conjugates under physiological conditions without the involvement of any factors harsh to cells. The data show that PAb-functionalized cells can recognize target cells much more effectively than monovalent controls. Moreover, dual Ab incorporation into the same PAb with a defined stoichiometric ratio leads to the formation of a polyvalent hybrid Ab (DPAb). DPAb-functionalized cells can effectively recognize target cell models with antigen escape, which cannot be achieved by PAbs with one type of Ab. Therefore, this work presents a novel biochemical method for Ab display on the cell surface for enhanced cell recognition.

High-affinity one-step aptamer selection using a non-fouling porous hydrogel.

Aptamers, commonly referred to as chemical antibodies, are used in a wide range of applications including drug delivery and biosensing. However, the process of aptamer selection poses a substantial challenge, as it requires numerous cycles of enrichment and involves issues with nonspecific binding. We present a simple, fast instrument-free method for aptamer enrichment and selection based on a diffusion-binding process in a three-dimensional non-fouling porous hydrogel with immobilized target proteins. Low-affinity aptamer candidates can be rapidly released from the hydrogel, whereas high-affinity candidates are restricted due to their strong binding to the immobilized protein targets. Consequently, a one-step enriched aptamer pool can strongly bind the protein targets. This enrichment is consistent across five proteins with isoelectric points in varying ranges. With thrombin as a representative model, the anti-thrombin aptamer identified from an enriched aptamer pool has been found to have a binding affinity that is comparable to those identified over ten cycles of selection using traditional methods.

A core-shelled Sb@C nanorod cathode with a graphene aerogel interlayer for high-capacity aluminum ion batteries.

Rechargeable aluminum-ion batteries, RAIBs, as a prime candidate for next-generation batteries, have attracted much attention due to their extremely high anode capacity and good safety. However, the lack of matching high-capacity cathode materials and reasonable design limit their practical development. Herein, core-shelled Sb@C nanorods are prepared by polymer coating and thermal reduction as a metal-based cathode for RAIBs. The carbon shell and graphene aerogel interlayer effectively block the diffusion and shuttling of charging products, thus exhibiting excellent electrochemical performance. This Al-Sb battery delivers an initial discharge capacity of 656 mA h g-1 at 100 mA g-1, a stable discharge voltage of 0.9 V, and excellent cycling stability maintained at 306 mA h g-1 after 500 cycles at 1 A g-1. Serial characterizations are used to monitor the structural changes of Sb in reversible reactions and to determine the configuration of the charged products, showing that the product exists in the form of [SbCl4]+ cations, that is, a five-electron transfer reaction occurs with a very high theoretical capacity (1100 mA h g-1). This study sheds light on the energy storage mechanism of a metallic Sb cathode in RAIBs, and provides new insights into the study of high-capacity cathodes and the rational design of battery structures.

Correction: Wang et al. Parametric Formula for Stress Concentration Factor of Fillet Weld Joints with Spline Bead Profile. Materials 2020, 13, 4639.

The authors wish to revise the following from pages 16-18 in the text of Appendix B [...].

Correction: Wang et al. Generalized SCF Formula of Out-Of-Plane Gusset Welded Joints and Assessment of Fatigue Life Extension by Additional Weld. Materials 2021, 14, 1249.

The authors wish to revise in the text of Appendix A, pages 19-21 [...].

Fatigue Life Assessment of Welded Joints by Combined Measurements Using DIC and XRD.

The existing methods of assessing the fatigue life of welded joints fail to consider local strain ranges and mean stress at the weld toe. The present work proposes a novel approach to assessing the fatigue life of welded joints by conducting measurements with digital image correlation (DIC) and X-ray diffraction (XRD) in combination. Local strain ranges at the weld toe of gusset welded joints were measured by DIC. Hammer peening was conducted on the welded joints to introduce different initial stresses. The influence of mean stress was investigated by considering initial residual stress measured by XRD and a perfect plastic material model. The fatigue experiment was carried out on specimens with and without hammer peening. The results showed that hammer peening could offset adverse welding deformation effectively, and introduce significant residual compressive stress. The fatigue failure life increased by more than 15 times due to hammer peening. The fatigue initiation life assessed by the proposed method was close to that based on nominal stress, indicating that the proposed method is reliable for predicting the fatigue initiation life of welded joints.

Generalized SCF Formula of Out-Of-Plane Gusset Welded Joints and Assessment of Fatigue Life Extension by Additional Weld.

The existing S-N curves by effective notch stress to assess the fatigue life of gusset welded joints can result in reduced accuracy due to the oversimplification of bead geometries. The present work proposes the parametric formulae of stress concentration factor (SCF) for as-welded gusset joints based on the spline model, by which the effective notch stress can be accurately calculated for fatigue resistance assessment. The spline model is also modified to make it applicable to the additional weld. The fatigue resistance of as-welded and additional-welded specimens is assessed considering the geometric effects and weld profiles. The results show that the error of SCFs by the proposed formulae is proven to be smaller than 5%. The additional weld can increase the fatigue life by as great as 9.4 times, mainly because the increasing weld toe radius and weld leg length lead to the smaller SCF. The proposed series of S-N curves, considering different SCFs, can be used to assess the welded joints with various geometric parameters and weld profiles.

Parametric Formula for Stress Concentration Factor of Fillet Weld Joints with Spline Bead Profile.

The existing parametric formulae to calculate the notch stress concentration factor of fillet welds often result in reduced accuracy due to an oversimplification of the real weld geometry. The present work proposes a parametric formula for the evaluation of the notch SCF based on the spline weld model that offers a better approximation of the real shape of the fillet weld. The spline model was adopted in FE analyses on T-shape joints and cruciform joints models, under different loading conditions, to propose a parametric formula for the calculation of the SCF by regression analysis. In addition, the precision of parametric formulae based on the line model was examined. The magnitude of the stress concentration was also analyzed by means of its probability distribution. The results show that the line model is not accurate enough to calculate the SCF of fillet weld if the weld profile is considered. The error of the SCF by the proposed parametric formulae is proven to be smaller than 5% according to the testing data system. The stress concentration of cruciform joints under tensile stress represents the worst case scenario if assessed by the confidence interval of 95% survival probability.

[Assessment of staging and prognostic scoring system for malignant trophoblastic neoplasia].

OBJECTIVE: To assess malignant trophoblastic neoplasia with the standards of the clinical stage and prognostic factor scoring system. METHODS: Through assessing the high-risk factors except clinical stages for 223 patients before treatment according to International Federation of Gynecology and Obstetrics (FIGO) scoring system published in 2000, appropriate treatments were selected for the different patients. RESULTS: Forty-three of 78 cases of choriocarcinomas were with high-risk factors, the other 35 cases were with low-risk factors; 7 of 145 cases of invasive moles were with high-risk factors and the others were with low-risk factors. The primary chemotherapy principle was that one agent was used for those patients with low-risk factors and two or multiple-agents were used for those patients with high-risk factors. Among all patients, the one-year, three-year and five-year survival rates were 98.6%, 98.1% and 97.1% respectively. No patient died of drug toxicity or complication. CONCLUSION: Selection of treatment approaches according to the prognostic assessment of malignant trophoblastic neoplasia could lead to promising survival rate with no uncurable complication and toxic effects.

Clinicopathological significance of ALDH1A1 in lung, colorectal, and breast cancers: a meta-analysis.

AIM: Aldehyde dehydrogenase 1 family member A1 (ALDH1A1) is a putative cancer stem cell marker. This meta-analysis evaluated ALDH1A1 expression's clinicopathological associations with lung cancer (LC), colorectal cancer (CRC) and breast cancer (BC). MATERIALS & METHODS: Publications were retrieved from various databases and assessed for relevance and quality. Relationships between ALDH1A1 expression and clinicopathological characteristics were evaluated using Review Manager 5.2 software. RESULTS: Thirty-eight studies were included (6057 patients). ALDH1A1 expression was significantly associated with the presence of LC; lymph node metastasis, clinical stage and differentiation in LC and BC; and molecular subtype in BC (p < 0.05). There were no significant association with BC tumor size and CRC. CONCLUSION: ALDH1A1 may be a stem cell marker in LC and BC.

Meta-analysis of the effect of mesenchymal stem cell transplantation on vascular remodeling after carotid balloon injury in animal models.

AIM: A meta-analysis was conducted to assess the efficacy of mesenchymal stem cell (MSC) transplantation in small animal coronary vessels after balloon injury, to provide data for the design of future pre-clinical experiments and human clinical trials. METHODS: The search strategy included the PubMed, EMBASE, Chinese Biomedical Literature (CBM), and China National Knowledge Infrastructure (CKNI) databases. The endpoint was the ratio of vascular neointima/media (I/M). Moreover, neointimal area, re-endothelialization, and proliferating cell nuclear antigen (PCNA) expression were analyzed. Pooled analyses were conducted using random effects models. Heterogeneity and publication bias were also explored. All data were analyzed using RevMan 5.2 and Stata 12.0. RESULTS: Fifteen studies were reviewed from 238 retrieved animal studies. Compared with controls, MSC transplantation resulted in greater I/M reduction (pooled difference, 0.39; 95% CI, 0.57-0.21; P < 0.0001), greater neointimal area reduction (pooled difference, 0.16; 95% CI, 0.22-0.10; P < 0.0001), decreased PCNA expression (pooled difference, 17.69; 95% CI, 28.94-6.44; P = 0.002), and enhanced re-endothelialization (pooled difference, 3.37; 95% CI, 1.78-4.95; P < 0.0001). The multivariable meta-regression analysis showed that a higher number of transplanted cells (>106; P = 0.017) and later time point of I/M measurement (P = 0.022) were significantly associated with I/M reduction. Subgroup analysis demonstrated a trend for a greater reduction in the ratio of I/M with late MSC transplantation (>1 day), MSCs transplanted through intravenous injection, and atherosclerotic vessels. CONCLUSION: The meta-analysis results demonstrate that MSC transplantation might improve injured vascular remodeling. In addition to greater efficacy with a greater number of transplanted MSCs (>106), the long-term effect of MSC transplantation appears to be more significant. The findings of this meta-analysis may help to design future, effective MSC trials.

[Low-dose rate intracavitary afterloading radiotherapy for cancer of uterine cervix].

OBJECTIVE: To evaluate the results of Gynatron low dose rate (LDR) brachytherapy for cancer of uterine cervix. METHODS: From April 1980 to June 1986, 136 patients with uterine cervical carcinoma were given radical radiotherapy through LDR afterloading irradiation and (60)Co external irradiation, compared with those through radium and high dose rate (HDR) intracavitary therapy. RESULTS: All patients except 5 were followed up for 15 years with a follow-up rate of 96.3% (131/136). The overall 10-year survival rate was 63.5%. The 10-year survival rates of stage II and III patients were 83.9% and 43.2%. The frequency of proctitis and cystitis were 12.5% (17/136) and 9.6% (13/136). CONCLUSION: Gynatron LDR system has achieved good results with tolerable complications including proctitis and cystitis which are more often than those of radium and less so than those of HDR.

[Combined treatment for locally advanced carcinoma of uterine cervix].

OBJECTIVE: To evaluate the feasibility of surgical management for patients with locally advanced carcinomas of uterine cervix after radical radiation therapy who were prone to develop central recurrence. METHODS: These 40 patients were treated by combined pre-operative radiotherapy with dose at point A of > 70 Gy in 30 patients, 60 approximately 70 Gy in 7, 50 approximately 59 Gy in 2 and 44 Gy in 1. The interval between radiation and surgery was 1 - 6 weeks. Extrafascial hysterectomy was performed in 15 patients, subradical hysterectomy in 23 and radical hysterectomy with pelvic lymphadenectomy in 2 cases. RESULTS: These patients have been followed up for 1 - 8 years with 2 died of other diseases and 12 died of cancer. Eighteen of the 26 survivors have been followed up for more than 5 years. The 3- and 5-year survival rates were 74.9% and 66.8%. Half of the death occurred within the first year after treatment. The 2-year death rate was 9/12 (75.0%). Three patients suffered from long term complications after the treatment, but all were cured by conservative management. CONCLUSION: The combination of hysterectomy performed shortly after radical radiotherapy, ie, for patients with locally poor prognostic cervical carcinoma is reasonable and feasible.

[Inhibitory effect of NS398 on the proliferation of human ovarian cancer cell lines CAOV3 and OVCAR3 in vitro].

OBJECTIVE: To observe the inhibitive effect of cyclooxygenase-2 (COX-2) selective inhibitor, [N-[2-(cyclohexyloxy)-4-nitrophenyl]-methane sulfonamide] (NS398, one of nonsteroidal anti-inflammatory drugs), on human ovarian cancer cell lines CAOV3 and OVCAR3 during the proliferative process in vitro. METHODS: Streptovidin peroxidase conjugated (SP) immunohistochemical assay was performed to examine the expression of COX-2 protein in human ovarian epithelial serous cancer cell lines CAOV3 and OVCAR3 respectively. The proliferative inhibition process of the two cell lines by NS398 was observed with methyl thiazolyl tetrazolium (MTT) rapid photocolorimetric assay. Cell morphologic changes were observed under the inverted phase contrast microscope and electron microscope. DNA ladder assay and terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling (TUNEL) assay were employed for the cell apoptosis. RESULTS: COX-2 protein was expressed in both of the cell lines. The inhibitory rate of proliferation exerted by NS398 increased with the density and the time of NS398 respectively. In contrast to the control, the absorbance of the experiment (NS398 200 micro mol/L for 72 h) decreased obviously (P < 0.05). With regard to the cell morphology, the "vacuole" presented in the cytoplasm and apoptosis body was able to be observed, and the microvilli on the surface of the cell disappeared. There were characteristic ladder bands after CAOV3 and OVCAR3 were treated by NS398 (100 micro mol/L) for 72 h. The brown-yellow granules located in the nucleus of most CAOV3 cells, which indicated apoptosis. CONCLUSIONS: Above findings suggest that COX-2 may provide an effective chemotherapeutic target for ovarian cancer, and selective COX-2 inhibitors can be used as chemotherapeutic agents for ovarian cancer.