Combination immunotherapy of glioblastoma with dendritic cell cancer vaccines,anti-PD-1 and poly I:C / 药物分析学报

Glioblastoma(GBM)is a lethal cancer with limited therapeutic options.Dendritic cell(DC)-based cancer vaccines provide a promising approach for GBM treatment.Clinical studies suggest that other immu-notherapeutic agents may be combined with DC vaccines to further enhance antitumor activity.Here,we report a GBM case with combination immunotherapy consisting of DC vaccines,anti-programmed death-1(anti-PD-1)and poly I:C as well as the chemotherapeutic agent cyclophosphamide that was integrated with standard chemoradiation therapy,and the patient remained disease-free for 69 months.The patient received DC vaccines loaded with multiple forms of tumor antigens,including mRNA-tumor associated antigens(TAA),mRNA-neoantigens,and hypochlorous acid(HOCl)-oxidized tumor lysates.Furthermore,mRNA-TAAAs were modified with a novel TriVac technology that fuses TAAs with a destabilization domain and inserts TAAs into full-length lysosomal associated membrane protein-1 to enhance major histo-compatibility complex(MHC)class Ⅰ and Ⅱ antigen presentation.The treatment consisted of 42 DC cancer vaccine infusions,26 anti-PD-1 antibody nivolumab administrations and 126 poly I:C injections for DC infusions.The patient also received 28 doses of cyclophosphamide for depletion of regulatory T cells.No immunotherapy-related adverse events were observed during the treatment.Robust antitumor CD4+and CD8+T-cell responses were detected.The patient remains free of disease progression.This is the first case report on the combination of the above three agents to treat glioblastoma patients.Our results suggest that integrated combination immunotherapy is safe and feasible for long-term treatment in this patient.A large-scale trial to validate these findings is warranted.

Synthesis and Evaluation of a Novel Small-molecule Compound as an Anticancer Inhibitor of CD147 / 生物医学与环境科学（英文）

OBJECTIVE@#Cancer is a serious threat to human health. Despite extensive research on cancer treatment, there is a growing demand for new therapies. CD147 is widely involved in tumor development, but it is unclear whether cancer cell malignancy is affected by CD147 expression level. The first compound (AC-73) targeting CD147 could only act on advanced tumors and inhibit metastasis. Therefore, new compounds with better anticancer activity should be explored.@*METHODS@#Wst-1 assays were used to confirm the effect of novel compounds on proliferation. Apoptosis tests were used to evaluate their proapoptotic capacity. A nude mouse model was used to demonstrate in vivo anticancer activity and safety of the compounds. Western blots were used to suggest a molecule mechanism.@*RESULTS@#There is a positive correlation between CD147 expression and tumor cell proliferation. A new compound, HA-08, was synthesized and proved to be more active than AC-73. HA-08 could inhibit cancer cell viability and promote cancer cell apoptosis both in vitro and in vivo. HA-08 induces cancer apoptosis, mainly by disrupting the CD147-CD44 interaction and then down-regulating the JAK/STAT3/Bcl-2 signaling pathway.@*CONCLUSION@#Our results have clarified the tumor specificity of CD147 and its drug target characteristics. The biological profile of HA-08 suggests that this compound could be developed as a potential anticancer agent.

Benchmark Dose Estimation for Cadmium-Induced Renal Effects Based on a Large Sample Population from Five Chinese Provinces / 生物医学与环境科学（英文）

A survey involving 6103 participants from five Chinese provinces was conducted to evaluate the threshold value of urinary cadmium (UCd) for renal dysfunction as benchmark dose low (BMDL). The urinary N-acetyl-β-D-glucosaminidase (UNAG) was chosen as an effect biomarker. The UCd BMDLs for UNAG ranged from 2.18 μg/g creatinine (cr) to 4.26 μg/g cr in the populations of different provinces. The selection of the sample population and area affect the evaluation of the BMDL. The reference level of UCd for renal effects was further evaluated based on the data of all 6103 subjects. With benchmark responses (BMR) of 10%/5%, the overall UCd BMDLs for males in the total population were 3.73/2.08 μg/g cr. The BMD was slightly lower in females, thereby indicating that females may be relatively more sensitive to Cd exposure than are males.

Eukaryotic Expression of ?ig-h_3 Gene and Its Effects on Secretion of MMPs in the Human Hepatoma 7721 Cells / 中国生物工程杂志

?ig-h_3 was first identified as a transforming growth factor-beta1-inducible gene in human lung adenocarcinoma cell line. It encodes for a secreted extracellular matrix (ECM) protein, which is thought to act on cell attachment and ECM composition. Previous study showed that ?ig-h_3 were highly expressed in human hepatoma cell lines and lowly expressed in human normal hepatic cells. The present study aimed to transfect ?ig-h_3 into 7721 cells to investigate its effect on secretion of MMPs in the transfected human hepatoma cells. Full-length ?ig-h_3 gene,cloned by reverse transcription polymerase chain reaction (RT-PCR) was inserted into the eukaryotic expression vector pEGFP-C_2. The recombinant plasmid was transfected into 7721 cells with Lipofectamine2000 and Gelatin-Zymography were adopted to detect the production of MMPs in the transfected cells. Results showed that ?ig-h_3/pEGFP-C_2 recombinant expression plasmid was successfully constructed and achieved high transfection efficiency. MMPs expression of the transfected cells was promoted significantly. These results suggest that overexpression of ?ig-h_3 promoted the production of MMPs, indicating that ?ig-h_3 may play roles in the invasive and metastatic processes of hepatoma.

DMSO arrested hybridoma cells for enhanced antibody production / 生物工程学报

Dimethyl sulfoxide (DMSO), a well-known differentiation inducer in several myeloid cells, induces G1 phase arrest in many cell lines. In this study, we investigated the possibility of using DMSO to arrest H18 hybridoma cells to the G1 phase and monitor whether the arrest improves antibody production. We showed that DMSO in concentration ranging between 0.3% and 0.6% efficiently arrested H18 hybridoma cells in G1 phase. In our experiment, > 80% of cells grown for 36h in presence of the 0.6% DMSO were arrested in G1. Furthermore, expression levels of P27 were up-regulated tow fold during the G1 phase. Higher concentration of DMSO at 0.9% leads to cytotoxicity. Herein we show a simple way, a two-stage process for antibody production, which consists of a proliferation phase leading to the desired cell density, followed by an extended production phase during which the cells remain at G1 phase. Our observation that the addition of DMSO results in increase antibody production is of significance in further use of hybridoma cells in high density large scale cell culture.

Effect of Ca2+ mobilization on release and activation of matrix metalloproteinases in hepatocellular carcinoma cells / 中华肿瘤杂志

<p><b>OBJECTIVE</b>To investigate the effect of Ca(2+) mobilization on release and activation of matrix metalloproteinases (MMPs) in human hepatocellular carcinoma cells.</p><p><b>METHODS</b>Ca(2+) and chemicals which can induce or inhibit Ca(2+) mobilization were added into human SMMC-7721 hepatoma cells in vitro. SDS-PAGE protein electrophoresis and gelatin zymography analysis were carried out to detect the changes of release and activation of MMPs in the cell culture supernatant.</p><p><b>RESULTS</b>Addition of CaCl(2) into culture system resulted in an enhanced secretion and activation of MMP-2 and MMP-9 in a dose-dependent manner. At a dose of 0.8 mmol/L CaCl(2), it maintained a stable high level of MMPs, especially of MMP-2 with (109.71 +/- 27.93)% elevation as compared to the cells without CaCl(2) addition (P < 0.001). SDS-PAGE analysis showed that most secreted proteins were MMPs (MMP-2 and MMP-9) when the cells cultured in media without serum. Thapsigargin (Tg, 4 micromol/L), an inducer of intracellular Ca(2+) stores depletion, significantly enhanced the release and activation of MMP-2 and MMP-9, compared to the control with (58.63 +/- 31.04)% elevation (P < 0.05), while the inducing effect of Tg on MMPs release and activation was significantly inhibited by S-nitro-N-acetylpenicillamine (SNAP, 200 micromol/L), an NO donor.</p><p><b>CONCLUSION</b>Intracellular Ca(2+) regulation pathways may play an important role in the process of release and activation of MMPs.</p>

Non-fused expression of HAb18GEF by reducing stability of translational initiation region in mRNA / 生物工程学报

To express the extracellular fragement of hepatoma associated antigen HAbl8G(HAb18GEF) in E. coli efficiently in a non-fusing way, the cDNA of HAb18GEF gene was inserted into prokaryotic expression vector pET21a + . The secondary structure and codon adaptation of translational initiation region (TIR, from-30 to + 39) in mRNA of recombinant vector HAb18GEF/ pET21a + was predicted simultaneously by computer-aided design. Stable Stem-Loop structures and many low-usage codons were detected in mRNA-TIR of non-optimized recombinant HAb18GEF/pET21a + vector. The stability of mRNA-TIR in recombinant HAb18GEF/pET21a + vector was reduced with following methods: (1) optimization of secondary structure (2) optimization of codon adaptation. These optimization were realized by non-continual site-directed mutagenesis without changing any amino acid sequence in TIR. After being checked through restriction endonuclease digestion and confirmed through nucleotide sequencing, the pre-optimized and post-optimized recombinant vectors were transformed into competent E. coli JM109-DE3. The resulted recombinant clones were selected randomly and induced by IPTG at 37 degrees C. The induced production of these recombinants was analyzed by SDS-PAGE, indirect ELISA, Western blot, and cell fractionation assay. The amount of HAb18GEF mRNA was also detected by RNA dot blot between pre-optimized recombinant and post-optimized recombinant. The results revealed that recombinant non-fused vectors HAb18GEF/pET21a + were successfully constructed and optimized in the secondary structure and codon adaptation of TIR respectively. The HAb18GEF was expressed efficiently in a non-fusing way in recombinant E. coli by secondary structure optimization or codon adaptation optimization. Whereas, no expression of HAb18GEF was detected in pre-optimized recombinants. The non-fused expression products-HAb18GEF, mainly as inclusion body in E. coli, yielded highly above 29.3%. A trait of expression HAb18GEF was also detected both in intermembrane space and in culture medium due to over-expression and cell leakage. Difference in non-fused expression level of HAb18GEF between secondary structure optimization and codon adaptation optimization was negligible. No difference in amount of transcribed mRNA of HAb18GEF between the pre-optimized and the post-optimized recombinants was detected. To sum up, it's feasible to express hepatoma associated antigen HAb18GEF in a non-fusing way by reducing the stability of TIR in mRNA.

Recovery and purification of monoclonal antibody producted by continuous perfusion culture using expended bed adsorption / 生物工程学报

Monoclonal antibody producted by continuous perfusion culture was recovered and purified by expended bed adsorption chromatography. A packed bed column XK16/20 was used for method scouting with Streamline SP adsorbent. Two expended bed columns Streamline-25 and -50 were used for method optimization and pilot scale experiment, respectively. The recovery yield of monoclonal antibody was above 90% in a 5 - 7 fold enhanced purity and 10 fold increased concentration. According to the different concentration of monoclonal antibody in cell culture broth, about 18 - 50L fluid can be treated in a single cycle. MAb purification from lab scale (400mg per cycle) to a small pilot scale (2g per cycle) has been achieved. Compared with packed bed adsorption, the preparation cycle was half shortened, and the cost of production and the complexity of process were decreased markedly. It has been proven that a purification process based on expended bed adsorption technique is simple, efficient and economical.

Bio-panning of antagonistic peptides against HAb18G/CD147 and their function of anti-hepatoma invasion / 中华肿瘤杂志

<p><b>OBJECTIVE</b>To screen out the HAb18G/CD147 binding peptides and find out an antagonist against hepatoma invasion.</p><p><b>METHODS</b>HAb18G/CD147 was purified by affinity chromatographic method and the antigen binding peptides acquired by bio-panning a phage-displayed 12-peptide library. After obtaining the sequence of the selected phage-displayed peptides, all the 9 peptides were synthesized by solid-phase method and identified by mass spectrograph. The peptides' anti-metastatic function was tested by Boyden Chamber assay.</p><p><b>RESULTS</b>The purified HAb18G/CD147, identified by Western blot (molecular weight about 65 kd) could be used to bio-pan the phage-displayed peptide library. After 3 rounds of bio-panning, 9 positive phage clones were selected and sequenced. The synthesized peptides had uneven inhibitory activities and three of them were able to markedly inhibit the hepatoma cell invasion (P < 0.01). The most effective peptide decreased by 90.1% of hepatoma cells migrating through the Boyden Chamber membrane as compared with the control.</p><p><b>CONCLUSION</b>Bio-panning the phage-displayed peptide library can be used successfully to screen out the antigen binding peptides. Hepatoma metastatic potential can be inhibited by peptide antagonist which could be a good foundation of developing peptide therapeutic agent against hepatoma metastasis.</p>

Modification of the antiapoptotic ability of H18 hybridoma cells / 生物工程学报

To construct eukaryotic expression vector containing murine bcl-XL and stably express it in H18 hybridoma cells in order to enhance hybridoma cells antiapoptotic ability. PCR was used to obtain 710bp murine bcl-XL cDNA from pGEM-T-bcl-XL. Then the recombinant expression vector pEF-bcl-XL was constructed by cloning bcl-XL cDNA into eukaryotic expression vector pEF by Pst I and Xho I double digestion. After transfection into H18 hybridoma cells through lipofectamine 2000, the stable expression cell line was screened by 800mg/L G418. The expression of bcl-XL gene was detected by Western blotting. Flow cytometer was used to test the modified hybridoma cells ability to resist apoptosis induced by 0.4mmol/L Sodium Butyrate. The eukaryotic expression vector pEF-bcl-XL was successfully constructed and stably expressed in H18 hybridoma cells. Our data showed that stably transfected H18 cells expressed high levels of Bcl-XL. Under the condition of 0.4mmol/L NaBu, the production of antibody was to be significantly increased by more than 3-fold in stably transfected H18, which resulted from suppressing the NaBu-induced apoptosis and allowing stably transfected H18 cells to grow at higher viability and extend culture longevity by > 3 days. The increased culture longevity by inhibition of NaBu-induced apoptosis by inducible expression of Bcl-XL combined with the enhanced secretion of antibody by NaBu contributed to the enhancement of final antibody concentration in the stably transfected H18 cells culture. The final antibody concentration of stably transfected H18 cells in the presence of NaBu was three-fold higher than that of H18 cells culture in the absence of NaBu. Together, our results showed that butyrate is of practical interest for production of antibody. NaBu-induced apoptosis of hybridoma cells could be inhibited by inducible expression of Bcl-XL. The expression of murine bcl-XL gene in hyridoma cells and the increasing antiapoptosis ability of hybridoma cells are of significance in further use of hybridoma cells in high density large scale cell culture.

On-line monitoring of oxygen uptake rate and its application in hybridoma culture / 生物工程学报

On-line analysis and control are critical for the optimization of product yields in animal cell culture. The close monitor of viable cell number helps to gain a better insight into the metabolism and to refine culture strategy. In this study, we use the oxygen uptake rate (OUR) to estimate the number of viable cell and the OUR-based feed-back control strategy for nutrients feeding to improve the efficiency of cell culture. A hybridoma cell line (HAb18) was cultured in fed-batch and perfusion model using serum free medium in 5L CelliGen Plus bioreactor (NBS Co., American) and 5L Biostat B bioreactor (Braun Co., Germany). The system and the method for online monitoring OUR in bioreactors, based on the dynamic measurement of dissolved oxygen (DO), were developed. The method of on-line cell concentration estimation was established based on the relationship between the growth of the hybridoma and the uptake rate of oxygen. This method was then used to determine OUR and the concentrations of cell, antibody, glucose, lactate, glutamine and ammonia in the bioreactors at given times. The relationship between OUR and nutrients metabolism was studied and OUR-based feed-back control strategy, which used the state deltaOUR = 0 as the regulation point, was established and used to control the rates of nutrients or medium feeding rate in the perfusion culture. The results showed that there was close relationship between OUR, concentration of live cells, productivity of antibody and consumption of glutamine. The sudden decrease in OUR may be caused by glutamine depletion, and with different delay times, the viable cell concentration and antibody productivity also decreased. The further analysis revealed the linear relationship between OUR and the density of live cells in the exponential growth phase as qOUR = (0.103 +/- 0.028) x 10(-12) mol/cell/h. These findings can be applied to the on-line detection of live cell density. Our study also indicated that by adjusting the perfusion rate with OUR-based feed-back control strategy, it is feasible to continuously increase in viable cell density and antibody concentration in the perfusion culture.

Continuous perfusion culture hybridoma cells for production of monoclonal antibody / 生物工程学报

Hybridoma cells were cultured by continuous perfusion in Fibra-Cel of 5L packed-bed bioreactor for 22 days in low serum or serum-free media. The corresponded amino acids were fed and serum concentration was decreased by analyzing glucose concentration, oxygen uptake rate, secretary antibody amount and amino acids concentration in culture supernatant. Comparing with continuous perfusion culture that amino acids were not fed, antibody amount of production was increased about 2-3 times. The inoculated cell density was 2.5 x 10(5) cells/mL, while the final cell density was 8.79 x 10(8) cells/mL. Antibody production was reached 295 mg/L/d at average level, and the highest level was reached 532 mg/L/d. These results provided a primary mode of enlarge culture for monoclonal antibody industralization.