PUMC-MB1 is a novel group 3 medulloblastoma preclinical model, sensitive to PI3K/mTOR dual inhibitor.

PURPOSE: Medulloblastoma (MB), a common and heterogeneous posterior fossa tumor in pediatric patients, presents diverse prognostic outcomes. To advance our understanding of MB's intricate biology, the development of novel patient tumor-derived culture MB models with necessary data is still an essential requirement. METHODS: We continuously passaged PUMC-MB1 in vitro in order to establish a continuous cell line. We examined the in vitro growth using Cell Counting Kit-8 (CCK-8) and in vivo growth with subcutaneous and intracranial xenograft models. The xenografts were investigated histopathologically with Hematoxylin and Eosin (HE) staining and immunohistochemistry (IHC). Concurrently, we explored its molecular features using Whole Genome Sequencing (WGS), targeted sequencing, and RNA sequecing. Guided by bioinformatics analysis, we validated PUMC-MB1's drug sensitivity in vitro and in vivo. RESULTS: PUMC-MB1, derived from a high-risk MB patient, displayed a population doubling time (PDT) of 48.18 h and achieved 100% tumor growth in SCID mice within 20 days. HE and Immunohistochemical examination of the original tumor and xenografts confirmed the classification of PUMC-MB1 as a classic MB. Genomic analysis via WGS revealed concurrent MYC and OTX2 amplifications. The RNA-seq data classified it within the Group 3 MB subgroup, while according to the WHO classification, it fell under the Non-WNT/Non-SHH MB. Comparative analysis with D283 and D341med identified 4065 differentially expressed genes, with notable enrichment in the PI3K-AKT pathway. Cisplatin, 4-hydroperoxy cyclophosphamide/cyclophosphamide, vincristine, and dactolisib (a selective PI3K/mTOR dual inhibitor) significantly inhibited PUMC-MB1 proliferation in vitro and in vivo. CONCLUSIONS: PUMC-MB1, a novel Group 3 (Non-WNT/Non-SHH) MB cell line, is comprehensively characterized for its growth, pathology, and molecular characteristics. Notably, dactolisib demonstrated potent anti-proliferative effects with minimal toxicity, promising a potential therapeutic avenue. PUMC-MB1 could serve as a valuable tool for unraveling MB mechanisms and innovative treatment strategies.

The association between albumin and C-reactive protein in older adults.

Albumin had been found to be a marker of inflammation. The purpose of our study was to investigate the relationship between albumin and C-reactive protein (CRP) in 3579 participants aged 60 to 80 years from the National Health and Nutrition Examination Survey (NHANES). In order to evaluate the association between albumin and CRP, We downloaded the analyzed data (2015-2018) from the NHANES in the United States, and the age of study population was limited to 60 to 80 years (n = 4051). After exclusion of subjects with missing albumin (n = 456) and CRP (n = 16) data, 3579 subjects aged 60 to 80 years were reserved for a cross-sectional study. All measures were calculated accounting for NHANES sample weights. We used the weighted χ2 test for categorical variables and the weighted linear regression model for continuous variables to calculate the difference among each group. The subgroup analysis was evaluated through stratified multivariable linear regression models. Fitting smooth curves and generalized additive models were also carried out. We found albumin negatively correlated with CRP after adjusting for other confounders in model 3 (ß = -0.37, 95% CI: -0.45, -0.28, P < .0001). After converting albumin from a continuous variable to a categorical variable (quartiles), albumin level was also negatively associated with serum CRP in all groups (P for trend < .001 for each). In the subgroup analysis stratified by gender, race/ethnicity, smoking, high blood pressure, the negative correlation of albumin with CRP was remained. We also found that the level of CRP further decreased in other race (OR: -0.72, 95% CI: -0.96, -0.47 P < .0001) and participants with smoking (OR: -0.61, 95% CI: -0.86, -0.36 P < .0001). Our findings revealed that albumin levels was negatively associated with CRP levels among in USA elderly. Besides, CRP level decreased faster with increasing albumin level in other race and participants with smoking. Considering this association, hypoalbuminemia could provide a potential predictive biomarker for inflammation. Therefore, studying the relationship between albumin and CRP can provide a screening tool for inflammation to guide therapeutic intervention and avoid excessive correction of patients with inflammation.

Syndecan-1 as an immunogene in Triple-negative breast cancer: regulation tumor-infiltrating lymphocyte in the tumor microenviroment and EMT by TGFb1/Smad pathway.

BACKGROUND: Immune checkpoint inhibitors are the most studied forms of immunotherapy for triple-negative breast cancer (TNBC). The Cancer Genome Map (TCGA) and METABRIC project provide large-scale cancer samples that can be used for comprehensive and reliable immunity-related gene research. METHODS: We analyzed data from TCGA and METABRIC and established an immunity-related gene prognosis model for breast cancer. The SDC1 expression in tumor and cancer associated fibroblasts (CAFs) was then observed in 282 TNBC patients by immunohistochemistry. The effects of SDC1 on MDA-MB-231 proliferation, migration and invasion were evaluated. Qualitative real-time PCR and western blotting were performed to identify mRNA and protein expression, respectively. RESULTS: SDC1, as a key immunity-related gene, was significantly correlated with survival in the TCGA and METABRIC databases, while SDC1 was found to be highly expressed in TNBC in the METABRIC database. In the TNBC cohort, patients with high SDC1 expression in tumor cells and low expression in CAFs had significantly lower disease-free survival (DFS) and fewer tumor-infiltrating lymphocytes (TILs). The downregulation of SDC1 decreased the proliferation of MDA-MB-231, while promoting the migration of MDA-MB-231 cells by reducing the gene expression of E-cadherin and TGFb1 and activating p-Smad2 and p-Smad3 expression. CONCLUSION: SDC1 is a key immunity-related gene that is highly expressed TNBC patients. Patients with high SDC1 expression in tumors and low expression in CAFs had poor prognoses and low TILs. Our findings also suggest that SDC1 regulates the migration of MDA-MB-231 breast cancer cells through a TGFb1-Smad and E-cadherin-dependent mechanism.

[N2O Emission from the Processes of Wastewater Treatment: Mechanisms and Control Strategies].

As a direct carbon emission source, the amount of nitrous oxide (N2, which is actually caused by AOB denitrification. To control the N2O emission during biological N-removal, complete HND and NO2- accumulation for AOB denitrification should be avoided to a large extent. For this purpose, DO in aerobic tanks should be controlled at a normal level (approximately 2 mg·L-1), and solid retention time (SRT) should be extended, up to 20 d, which would avoid accumulating N2O for AOB denitrification. Additionally, external carbon should be supplemented in time to promote HDN approaching the end, N2. This review summarizes the mechanisms of all the mentioned N2O emission pathways and discusses the control strategies of N2O emission according to the associated mechanisms.

Soft Sensor Modeling Method Based on Improved KH-RBF Neural Network Bacteria Concentration in Marine Alkaline Protease Fermentation Process.

Marine alkaline protease (MAP) fermentation is a complex multivariable, multi-coupled, and nonlinear process. Some unmeasured parameters will affect the quality of protease. Aiming at the problem that some parameters are difficult to be detected online, a soft sensing modeling method based on improved Krill Herd algorithm RBF neural network (LKH-RBFNN) is proposed in this paper. Based on the multi-parameter RBFNN model, the adaptive RBF neural network algorithm and control law are used to approximate the unknown parameters. The adaptive Levy flight strategy is used to improve the traditional Krill Herd algorithm, improve the global search ability of the algorithm, and avoid falling into local optimization. At the same time, the location update formula of Krill Herd algorithm is improved by using the calculation methods of similarity and agglomeration degree, and the parameters of adaptive RBFNN are optimized to improve its over correction and large amount of calculation. Finally, the soft sensing prediction model of bacterial concentration and relative active enzyme in map process based on LKH-RBFNN is established. The root mean square error and maximum absolute error of this model are 0.938 and 0.569, respectively, which are less than KH-RBFNN and PSO-RBFNN prediction models. It proves that the prediction error of LKH-RBFNN model is smaller and can meet the needs of online prediction of key parameters of map fermentation.

Synthesis and characterization of promising insensitive energetic salts based on 3-amino-5-hydrazinopyrazole.

The development of green energetic materials is based on environmental friendliness, safety and performance improvement. It is of great significance to design and synthesize new nitrogen rich salts for a new generation of green energetic materials. In the present work, a series of 3-amino-5-hydrazinopyrazole energetic salts comprising energetic anions were synthesized and were characterized using elemental analysis, IR spectroscopy and differential scanning calorimetry (DSC). Compounds 1-5 were further confirmed by single crystal X-ray diffraction and the sensitivities were measured by the standard BAM methods. Additionally, the structure-property relationship was elucidated from the experimental results and theoretical calculations. Energetic salts of 2 and 5 exhibited high heat of formation (5, 1160.06 kJ mol-1), high decomposition temperature (2, 172 °C; 5, 186 °C), excellent detonation performance (2, Dv, 9076 m s-1, P 34.1 GPa; 5, Dv, 8974 m s-1, P 31.9 GPa), moderate sensitivity towards outer stimuli and high nitrogen contents (2, 41.03%; 5, 63.84%). This work increases future prospects for the design of insensitive and novel high-energy green energetic material.

Mechanism and kinetics of the atmospheric reaction of 1,3,5-trimethylbenzene bicyclic peroxy radical with OH.

The bicyclic peroxy radical (BPR) is the key intermediate during atmospheric oxidation of aromatics. In this paper, the reaction mechanisms and kinetics of the atmospheric reaction of the 1,3,5-trimethylbenzene (1,3,5-TMB) BPR with the OH radical were studied by density functional theory (DFT) and conventional transition-state theory (CTST) calculations. The product channels of formation of the 1,3,5-TMB trioxide (ROOOH), OH-adducts and Criegee intermediate (CI) have been identified, and the geometries and energies of all the stationary points were calculated at the M08-HX/6-311 + g(2df,2p) level of theory. In addition, the rate constants for the individual reaction pathway at 298 K were calculated. The results showed that OH addition reactions including the formation of ROOOH and OH-adducts are the main pathways, whereas Criegee intermediate formation is of minor importance.

Computational study on the mechanism and kinetics for the reaction between HO2 and n-propyl peroxy radical.

The n-propyl peroxy radical (n-C3H7O2) is the key intermediate during atmospheric oxidation of propane (C3H8) which plays an important role in the carbon and nitrogen cycles in the troposphere. In this paper, a comprehensive theoretical study on the reaction mechanism and kinetics of the reaction between HO2 and n-C3H7O2 was performed at the CCSD(T)/aug-cc-pVDZ//B3LYP/6-311G(d,p) level of theory. Computational results show that the HO2 + n-C3H7O2 reaction proceeds on both singlet and triplet potential energy surfaces (PESs). From an energetic point of view, the formation of C3H7O2H and 3O2 via triplet hydrogen abstraction is the most favorable channel while other product channels are negligible. In addition, the calculated rate constants for the title reaction over the temperature range of 238-398 K were calculated by the multiconformer transition state theory (MC-TST), and the calculated rate constants show a negative temperature dependence. The contributions of the other four reaction channels to the total rate constant are negligible.

A Combination of Species Identification and STR Profiling Identifies Cross-contaminated Cells from 482 Human Tumor Cell Lines.

Human tumor cell lines are extremely important tools for cancer research, but a significant percentage is cross-contaminated with other cells. Short tandem repeat (STR) profiling is the prevailing standard for authenticating cell lines that originate from human tissues. Based on the analysis of 482 different human tumor cell lines used in China by STR, up to 96 cell lines were misidentified. More importantly, the study has found that STR profiling alone is insufficient to exclude inter-species cross-contamination of human cell lines. Among the 386 cell lines which had a correct STR profile, 3 of them were inter-species cross-contaminated. Careful microscopic examination may be helpful in some cases to detect changes in morphology but additional testing is needed. Additionally, species verification by PCR could easily identify the contaminants, even with a low percentage of contaminating cells. Combining STR profiling with species identification by PCR, more than 20.5% (99/482) of tumor cell lines were revealed as having been incorrectly identified, including intra-species (14.5%), inter-species (4.4%) cross-contamination and contaminating cell lines (1.7%). Therefore, quality control of cell lines is a systemic issue. Each cell line should undergo a full QA (Quality Assurance) assessment before it is used for research.

Intrinsic gene changes determine the successful establishment of stable renal cancer cell lines from tumor tissue.

Human tumor cell lines, especially those with complete data and follow-up, are important tools in tumor biological studies. Clear cell renal cell cancer (ccRCC) is not sensitive to radiotherapy or chemotherapy, and treatment of patients with distant metastasis relies on targeted therapy. Here, we report the establishment of seven new ccRCC stable cell lines that were continuously cultured for more than 20 generations among 81 cases of renal cell cancer. Moreover, gene expression and methylation in the established cell lines, in those that had a finite in vitro life span of less than 10 generations, and in cells that originated from the same culture at different generations were profiled using microarrays. Genes including SLC34A2, SEPP1, SULT1C4 and others were differentially expressed in established cell lines and finite cell lines, and changes in their expression might be caused by methylation or demethylation. The expression level of SLC34A2 was related not only to the life span in vitro culture but also to tumor size. Additionally, six of the seven new ccRCC cell lines had VHL deletions or termination mutations. So in addition to the establishment of seven new ccRCC cell lines with complete clinical data, we conclude that genes such as SLC34A2 and VHL play key roles in the continuous in vitro growth and development of ccRCC.

Cloning and expression of a novel target fusion protein and its application in anti-tumor therapy.

BACKGROUNDS: Epidermal growth factor (EGF) is a 53 amino acid polypeptide and its receptor EGFR is an established therapeutic target for anti-tumor therapy. Two major categories of EGFR-targeted drugs include monoclonal antibodies (mAbs) and small molecular tyrosine kinase inhibitors (TKIs). However, drug resistance occurs in a significant proportion of patients due to EGFR mutations. Since EGFR can maintain activation while abrogating the activity of mAbs or TKIs, or bypass signaling functions while successfully circumventing the EGF-EGFR switch, developing new mechanism-based inhibitors is necessary. METHODS: In this study, based on the principle of tumor immunotherapy, a recombinant protein pLLO-hEGF was constructed. The N-terminal portion contains three immunodominant epitopes from listeriolysin O (LLO) and the C-terminal includes EGF. To use EGF as a target vector to recognize EGFR-expressing cancer cells, immunodominant epitopes could enhance immunogenicity of tumor cells for immune cell activation and attack. RESULTS: Recombinant protein pLLO-hEGF was successfully expressed and showed strong affinity to cancer cells. Also, pLLO-hEGF could significantly stimulate human lymphocyte proliferation and the lymphocytes demonstrated enhanced killing potency in EGFR-expressing cancer cells in vitro and in vivo. CONCLUSION: This study can provide novel strategies and directions in tumor biotherapy.

[Enhanced growth inhibition by combined two pathway inhibitors on K-ras mutated non-small cell lung cancer cells].

OBJECTIVE: To evaluate the effect of combined targeting of MEK and PI3K signaling pathways on K-ras mutated non-small cell lung cancer cell line A549 cells and the relevant mechanisms. METHODS: A549 cells were treated with different concentrations of two inhibitors. Growth inhibition was determined by MTT assay. According to the results of MTT test, the cells were divided into four groups: the control group, PI3K inhibitor group (GDC-0941,0.5 and 5.0 µmol/L), combination group I (0.5 µmol/L AZD6244+0.5 µmol/L GDC-0941) and combination group II (5.0 µmol/L AZD6244+5.0 µmol/L GDC-0941). The cell cycle and apoptosis were analyzed by flow cytometry. The expression of proteins related to apoptosis was tested with Western blot. RESULTS: Both GDC-0941 and AZD6244 inhibited the cell proliferation. The combination group II led to a stronger growth inhibition. The combination group I showed an antagonistic effect and combination group II showed an additive or synergistic effect. Compared with the control group, the combination group I led to reduced apoptotic rate [(20.70 ± 0.99)% vs. (18.65 ± 0.92 )%, P > 0.05]; Combination group II exhibited enhanced apoptotic rate [(37.85 ± 3.18)% vs. (52.27 ± 4.36)%, P < 0.01]. In addition, in the combination group II, more A549 cells were arrested in G0/G1 phase and decreased S phase (P < 0.01), due to the reduced expressions of CyclinD1 and Cyclin B1, the increased cleaved PARP and the diminished ratio of Bcl-2/Bax. CONCLUSIONS: For single K-ras mutated NSCLC cell line A549 cells, combination of RAS/MEK/ERK and PI3K/AKT/mTOR inhibition showed synergistic effects depending on the drug doses. Double pathways targeted therapy may be beneficial for these patients.

[Growth inhibition of combined pathway inhibitors on KRAS mutated non-small cell lung cancer cell line].

OBJECTIVE: To investigate the effect of the selective PI3K inhibitor and MEK inhibitor on KRAS and PTEN co-mutated non-small cell lung cancer cell line NCI-H157 and the relevant mechanisms. METHODS: NCI-H157 was cultured routinely and treated with different concentrations of the two inhibitors. Cell proliferation was detected by MTT cell cycle assay. Based on the MTT results the cells were divided into four groups: the control group, PI3K inhibitor group (GDC-0941, 0.5 and 5.0 µmol/L), combination group I (0.5 µmol/L AZD6244 + 0.5 µmol/L GDC-0941) and combination group II (5.0 µmol/L AZD6244 + 5.0 µmol/L GDC-0941). Colony formation assay was performed to detect colony formation efficiency. The cell cycle and apoptosis were analyzed by flow cytometry. The expression of protein related to apoptosis was tested with Western blot. RESULTS: Cell growth was inhibited by the two inhibitors. Combination groups led to stronger cell proliferation inhibition: combination group Ishowed synergistic effect of their actions and combination group II showed an additive effect; in both groups, there were decreased colony number [(77.2 ± 1.54)/well vs (61.50 ± 2.12)/well, P < 0.01] and [(51.00 ± 4.00)/ well vs (22.50 ± 3.53)/well, P < 0.01]; and enhanced apoptotic ratios [(18.30 ± 0.82)% vs (21.32 ± 0.56)%, P < 0.01] and [(27.14 ± 1.58)% vs (42.45 ± 4.42)%, P < 0.01]. In addition, compared to the PI3K inhibitor alone group, the NCI-H157 cells in the combination groups showed increased G0/G1 phase and decreased S phase (P < 0.01). Western blotting showed that the combination groups demonstrated significantly decreased expression of cyclin D1 and cyclin B1, increased p21 and cleaved PARP and decreased bcl-2/bax ratio, compared to the PI3K inhibitor only group. CONCLUSION: The combined inhibition of PI3K (AZD6244) and MEK (GDC-0941) has synergistic effects on the proliferation of NCI-H157 cells, but such effects appear to be in a dose-dependent manner.

CD133 affects the invasive ability of HCT116 cells by regulating TIMP-2.

CD133 is widely expressed in colorectal cancer (CRC) tissues and cell lines. This protein has been used as a marker of CRC cancer stem cells, although the function and mechanism of CD133 in CRC invasion and metastasis remain unclear. In our study, we examined the role of CD133 in CRC invasion in vitro and investigated the mechanism involved in CD133-related invasion. CD133(high) and CD133(low) HCT116 cells were isolated, and the proliferation and invasive ability of these two subpopulations were tested. CD133(high) HCT116 cells exhibited greater proliferation and invasion compared with CD133(low) HCT116 cells. CD133 knockdown (using CD133 small-interfering [si]RNA) inhibited the invasive activity of CD133si-HCT116 cells. For the first time, we found that the expression of tissue inhibitor of matrix metalloproteinases-2 (TIMP-2) was down-regulated in CD133si-HCT116 cells. In addition, for the TIMP-2si-HCT116 cells (transfected with TIMP-2 siRNA), in vitro invasion was significantly decreased, whereas the expression of CD133 remained unchanged. Finally, the metalloproteinase 2 and MEK/ERK signaling pathways were examined, and no significant change was observed after the knockdown of CD133 or TIMP-2 in HCT116 cells. In conclusion, we demonstrated that CD133 plays an important role in HCT116 cell invasion, and for the first time, we found that CD133 knockdown significantly down-regulated TIMP-2 expression, which suggests that CD133 affects the invasive ability of HCT116 cells by regulating TIMP-2.

Detection of SRS19-6MuLV in mouse dendritic cell sarcoma and its tumorigenesis.

SRS19-6MuLV is a member of the MuLV family originally isolated from the Tianjin-Shanghai-Zunyi complex of murine leukemia. A notable characteristic of this virus is that it induces tumors of multiple hematopoietic lineages, including myeloid, erythroid, T-lymphoid and B-lymphoid. In a previous study, a sequence with high homology to SRS19-6MuLV in a murine dendritic cell sarcoma (DCS) was identified through cDNA expression screening with mAb 983D4. To investigate the relationship between SRS19-6MuLV and DCS, the existence of a specific SRS19-6MuLV DNA fragment in DCS cells, 15 murine tumor cells, 2 murine tumor tissues, 12 normal murine cells/tissues, 11 human tumor cell lines and SRSV/3T3 (NIH/3T3 cells infected with SRS cell supernatant) was detected by PCR. The specific fragment of SRS19-6MuLV was detected in DCS, mouse fore-gastric cancer cells, LⅡ tumor tissue from which DCS is derived and SRSV/3T3. In addition, the integration sites of SRS19-6MuLV in the positive cells were examined by inverse PCR. Thus, 7 integration sites for SRS19-6MuLV were detected in DCS and 3 in SRSV/3T3. Analysis of sequences by BLAST revealed that some of the integration sites were associated with common fragile sites and some Ras-regulating miRNAs. Our results indicate that SRS19-6MuLV not only induced four types of leukemia, but also induced DCS. This virus does not infect human cells. Multiple integration of SRS19-6MuLV into chromosomes around fragile sites accounts for its carcinogenic effects.

[Effect of forced E-cadherin expression on adhesion and proliferation of human breast carcinoma cells].

OBJECTIVE: To investigate the role that E-cadherin (E-cad) plays on cell adhesion and proliferation of human breast carcinoma. METHODS: E-cad expression vector was transfected into an E-cad-negative human breast carcinoma MDA-MB-231 cells. G418 was used to screen positive clones. E-cad, ß-catenin (ß-cat) and cyclin D1 expressions of these clones were confirmed by Western blot. Their cell-cell and cell-matrix adhesion abilities were detected. E-cad/ß-catenin interaction was confirmed by immunoprecipitation. Cell proliferation was evaluated by MTT. Cell apoptosis was analyzed by flow cytometry. Direct two-step immunocytochemistry was used to detect the localization of ß-cat. RESULT: E-cad(+) cell strains Ecad-231-7 and Ecad-231-9 were established. When cultured in ultra-low-binding dishes Ecad-231 cells grow in suspension while Ecad-231-7 and Ecad-231-9 cells grow in large clamps. When co-cultured with HCT116 cells, the average adhesion rates at 30 min are 39.0%, 60.0% and 59.5% for MDA-MB-231, Ecad-231-7 and Ecad-231-9 respectively. The average detachment rates by EDTA for 5 min are 37.4%, 4.2% and 7.4% respectively. So E-cad expression enhanced hemotypic and heterotypic cell-cell adhesion and cell-matrix adhesion. Forced exogenously expressed E-cad could combine with endogenous ß-cat, whereas down stream cyclin D1 expression was significantly decreased, as evidenced by Western blot. The rates of cell apoptosis of MDA-MB-231, Ecad-231-7 and Ecad-231-9 were 1.8%, 2.0% and 2.1%. Expression of E-cad had no obvious effect on the apoptosis of tumor cells with regular culture. ß-cat increased in the cytoplasma. CONCLUSIONS: Two monoclonal tumor cell strains (Ecad-231-7 and Ecad-231-9) stably expressing E-cad were successfully established. E-cad could enhance adhesion and inhibit proliferation of human breast carcinoma cells through a pathway involving ß-cat and cyclin D1.

Expression of CD133 correlates with differentiation of human colon cancer cells.

CD133 has been identified as a cancer stem cell marker in colon and several other cancers, but its function is still unknown. We examined the CD133 expression in 44 human cancer cell lines, and found five of the 8 positive lines were from colon cancer. The CD133 positive subpopulation of colon cancer cells showed more vigorous growth and lower differentiation. Induction of differentiation reduced the CD133-positive population. Knockdown of CD133 expression in colon cancer cells could not induce cellular differentiation. Care must be taken if CD133 is used as the only marker of cancer stem cells in colon cancer, especially in established cell lines. CD133 negatively correlates with cell differentiation, but it is not a regulator of differentiation.

[Expression and function of VAP-33 in murine dendritic cell sarcoma].

OBJECTIVE: To elucidate the expression and function of VAP-33 gene in dendritic cell sarcoma (DCS) cell line. METHODS: The expression of VAP-33 in DCS cells was investigated by mass spectrum with immunoprecipitation membrane protein. DCS cells were treated with antigens in different dosages (150, 850, and 1500 microl) for 24, 48 and 72 h respectively. Cell morphology and phagocytosis activity of DCS cells were measured. Indirect immunofluorescence, confocal microscopy and Western blotting were used to study the distribution and expression changes of VAP-33. Moreover, DCS cells were treated with 0.5 mol/L insulin for 20 min first and followed by Western blotting to detect changes of VAP-33 and glucose transfer protein 4 (GLUT-4) in the total cellular protein, cytoplasmic protein and membrane protein. Confocal microscopy was used to document the expression and distribution changes of VAP-33 and GLUT-4 in DCS cells. RESULTS: VAP-33 expression was obtained at the cell membrane and in the cytoplasm of DCS cells. Upon antigen stimulation, DCS cells showed more active phagocytosis and morphologically became more elongated with branched protrusions. The expression of VAP-33 was decreased by the antigen stimulation. Upon the insulin stimulation, the expression of VAP-33 and GLUT-4 were increased and co-localized. CONCLUSIONS: VAP-33 expression in DCS originated from the dendritic cells (DC) seemed relating to the vesicle transportation during antigen processing in DC. Additionally, VAP-33 and GLUT-4 also take part in the glucose transportation in the cells.

[Establishment of green-fluorescent protein expressing tumor metastasis models].

OBJECTIVE: To establish a green-fluorescent protein (GFP) labeled tumor metastasis model and to evaluate its biological characteristics. METHODS: Human gastric carcinoma cell MGC-803 and murine cervical carcinoma cell U14 were transfected with the plasmid pEGFP-N1 and the efficiency of transfection was assessed 24 h later. Limited dilution was employed to screen and establish monoclonal cell strains, MGC-803-GFP and U14-GFP. The two fluorescent tumor cell stains were transplanted into BALB/c-nu mice and C57BL/6J mice respectively. The latency period of tumor mass appearance and the growth curve in vivo were documented. The tumor growth and metastasis were evaluated in vivo by the Viviperception Fluorescence Imagining System (VFIS). Expressions of CD44 and E-cadherin in tumor tissue were monitored by immunohistochemistry. RESULTS: The efficiency of pEGFP-N1 transfection of MGC-803 cells and U14 cells were 30% and 60%, respectively. Monoclonal GFP(+) cell strains-MGC-803-GFP and U14-GFP were established. The latency periods of tumor formation of MGC-803-GFP and U14-GFP were 3-5 days and 2-4 days, respectively. Their tumorigenicity rates were 100% in both. The tumor growth of MGC-803-GFP was well defined by the VFIS. Only one mouse was shown to harbor lymphatic metastasis by VFIS, 60 days after transplantation. The metastasis process of U14-GFP was depicted through VFIS on 27, 37 and 52 days post-transplantation. The incidence of pulmonary metastasis and lymphatic metastasis of U14-GFP was 67% and 100% respectively when the tumor volume was >or=5 cm3. CD44 was positive and E-cadherin was negative in both tumors by immunohistochemistry. CONCLUSIONS: Successfully established two monoclonal tumor cell strains stably expressing GFP: MGC-803-GFP and U14-GFP. Transplantation of these cells into mice can establish tumor metastasis models which could be used for future visualized tumor research in vivo.