ABSTRACT
As a living cell product, chimeric antigen receptor (CAR)-T cell therapy displays multiple characteristics including the diversity of raw materials, the complexity of manufacturing process and the complementarity of quality control set. Pharmaceutical research and evaluation of CAR-T cell therapy are fundamentally different from small molecule and macromolecular recombinant proteins. Chemistry manufacturing and controls (CMC) review of investigational new drug (IND) submission for CAR-T therapy should especially pay attention to above unique characteristics and focus on potential risks to ensure clinical safety. Based on questions and concerns from recent CMC review practice and workshop on CAR-T cell therapy IND application, the critical points to consider for CMC study is proposed, and questions related to supplementation are also discussed in this review to accelerate the clinic translation of CAR-T therapy.
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The oncogene Bmi-1 is a member of the Polycomb group gene family. Its expression is found to be greatly increased in a number of malignant tumors including breast cancer. This could suggest Bmi-1 as a potent therapeutic target. In this study, RNAi was introduced to down-regulate the expression of Bmi-1 in a highly malignant breast adenocarcinoma cell line, MCF-7. A thorough study of the biological behavior and chemosensitivity changes of the MCF-7 cells was carried out in context to the therapeutic potential of Bmi-1. The results obtained indicated that siRNA targeting of Bmi-1 could lead to an efficient and specific inhibition of endogenous Bmi-1 activity. The mRNA and protein expression of Bmi-1 were determined by RT-PCR and Western blot, respectively. Furthermore, silencing of Bmi-1 resulted in a drastic inhibition of the growth of MCF-7 cells as well as G1/S phase transition. The number of target cells was found to increase in phase G0/G1 and decrease in the S phase, but no increase in the basal level of apoptosis was noticed. On the other hand, a reduction in the expression of cyclin D1 and an increase in the expression of p21 were also noticed. Silencing of Bmi-1 made the MCF-7 cells more sensitive to the chemotherapeutic agent doxorubicin and induced a significantly higher percentage of apoptotic cells. Here, we report on a study regarding the RNAi-mediated silencing of the Bmi-1 gene in breast cancer.
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Objective:To clone the rat cardiac myosin ? heavy chain cDNA fragment encoding aa736 960 and construct its recombinant retrovirus vector Methods:The 681 bp target gene was amplified from heart tissue of young rats with RT PCR Fusion gene of hIL 2/myosin was constructed by splicing with preserved region of hIL 2 cDNA using ligation methods and subsequently the plasmid pLNC hIL 2 myosin was constructed NIH3T3 cells and PA317 cells were transfected with plasmid pLNC hIL 2 myosin using Lipofectamine After screening with medium containing G418, the positive clone was chosen and was detected using RT PCR, immunohistochemistry, immune electron microscope and dot blot Results:The determination of nucleotide sequence showed that the nucleotide and amino acid sequence of the gene cloned was the same as the reported sequence, and its open reading frame was correct RT PCR analysis indicated that mRNA of the fused gene was present in the positive clone Immunohistochemistry, immune electron microscope and dot blot showed that the fused gene IL 2 myosin was successfully expressed Conclusion:The fused gene of rat cardiac ? heavy chain fragment and the preserved region of human IL 2 was constructed and expressed successfully
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Objective In order to study the pathogenesis of human papillomavirus(HPV) and seek for a therapeutic approach of the diseases caused by HPV, the construction of HPV18 E6E7 antisense RNA expressing recombinants was studied. Methods We amplified the HPV18 E6E7 816bp by PCR with HPV18 plasmid DNA as the template. pLNSX retroviruses were used as vectors,the HPV18 E6E7 retrovirus recombinants were constructed. And then the recombinants were cleaved with restriction endonuclease and hybridized with Southern blot for identifying the inserting direction and special check respectively. Results and conclusion The HPV18 E6E7 antisense RNA retrovirus expressing recombinants were screened and obtained,which had laid the foundation of studying the function of E6E7 genes further and explore whether the antisense technique can adjust and control the expression of E6E7 genes.
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In order to study the antitumor effect of human tumor necrosis factor alpha (TNF-?)gene modified fibroblasts, we have transfered TNF-? cDNA to fibroblasts NIH3T3 by a bicistronic retroviral vector pGCEN/TNF-?, which expressed TNF-? from the long terminal repeat and the selectable Neo~R from the encephalomyocarditis virus (EMCV) internal ribo-some entry site(IRES) . The results indicated that TNF-? modified NTH3T3, NIH3T3/TNF-? ,were able to express TNF-? at a high level for a long term culture. Furthermore, these modified fibroblasts could inhibit tumor progression signifi-cantly(P
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In this experiment, we introduced human interleukin-2(lL-2)gene and Neomycin resistance (Neo~R) gene into a human lung adenocarcinoma cell line GLC, using a retroviral vector PLXSN. The positive cells obtained by selecting in G418 were compared with the wild-type cells. We observed their growth characteristics in vitro and the quantity of IL-2 in the culture supernatants. PCR result demonstrated the integration of foreign genes into tumor genome DNA after transfection and permanent existence. Under electron microscope, what can be seen was the surface villi of trans-duced-cells are less and shorter. It deserves further investigation to determine whether the change of cell surface influence metastatic ability of cells.
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AIM:To explore the inhibitory effects of tumor associated mitochondrial protein 12 (TAMP12) on tumor cell apoptosis. METHODS: (1) A retrovirus expression vector was recombinated and transfected into the packaging cell line PA317. The virus particles were obtained to infect the target cell line HepG2 low expressing of TAMP12. The expression of TAMP12 mRNA was detected by RT-PCR. The subcellular localization and quantification of TAMP12 protein labeled with double fluorescein were observed under confocal laser scanning microscope (CLSM). (2) Hoechst33258 staining and flow cytometry (FACS) were used to analysis the apoptosis of HepG2 cells treated with 5-fluorouracil (5-FU). RESULTS: (1) The CLSM observation showed that TAMP12 protein was mainly expressed in mitochondria of HepG2 cells. The expressions of TAMP12 gene and protein were stable and high in transfected HepG2 cells. (2) Upon treatment with 5-FU, the transfected HepG2 cells showed a fairly integrated nucelus while the control HepG2 cells exhibited chromatin condensation, marginalization and karyorhexix. Moreover, the apoptosis rate of transfeced HepG2 cells was significantly lower than that in control HepG2 cells (P
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AIM: To construct a recombinant retrovirus vector carrying hTERT for establishing UCBMSCs with hTERT(hTERT-MSCs) to overcome their limited life span and detecting whether telomerized UCBMSCs line maintained long-term self-renewal and differentiation capacity.METHODS: The whole cDNA was generated by PCR amplifications from the plasmid pEGFP-hTERT-C1.The hTERT segments were subcloned into pLNCX2.The target cells were infected with these retroviral particles.The stably transfected cells were selected by neomycin and expanded life span which were designated hTERT-MSCs was observed.The expression of hTERT in mRNA level was detected by RT-PCR and the telomerase activity was measured by TRAP(PCR)-ELISA assay.The hTERT-MSCs were induced with 5-azacytidine to cardiac muscle cells and the specific marker of myocardiocyte was detected.RESULTS: The constructed plasmids were digested with restriction endonucleases(BglⅡand NotⅠ).Two characteristic segments including 6.1 kb and 3.6 kb were obtained.The hTERT-MSCs expressed hTERT in mRNA level.The telomerase activity of hTERT-MSCs was positive.The growth kinetics of hTERT-MSCs was higher than those in UCBMSCs.The hTERT-MSCs were induced to myocardiocyte.CONCLUSION: The hTERT recombinant retrovirus vector has been successfully constructed.The hTERT gene activates the telomerase and prolongs the life-span of cells.No effect of hTERT gene on some type of differentiation potential of MSCs is present.
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Objective To explore the effects of expressing human ciliary neurotrophic factor (hCNTF) mediated by retroviral vector in olfactory ensheathing cells(OECs) on the survival and neurite outgrowth of cultured neurons. Methods S\|hCNTF fragment was digested with endonucleases(Kpn I and Xba I) from pcDNA\-3\|S\|hCNTF plasmid and cloned into pRev\|TRE vector.The harvested pRev\|TRE\|hCNTF was identified and transfected with pRev\|Tet\|On into ecotropic Ecopack\|293 cells,resulting in 2 retroviral supernatants(pRev\|TRE\|hCNTF and pRev\|Tet\|On).Primarily cultured rat olfactory ensheathing cells(OECs) were co\|infected with the 2 retroviruses,and induced to secrete hCNTF with different concentrations of doxycline.The secreted hCNTF in OEC culture supernatant was detected with Western\|blot.Dorsal root ganglion (DRG) from a postnatal rat of 2 days was co\|cultured with CNTF\|modified OECs,and the supernatant was used to culture retinal ganglion cells(RGCs).Following ?\|tubulin immunocytochemical staining,the length of DRG neurites were measured,while the numbers of surviving RGCs were counted. Results 1.Individual 630bp and 400bp fragments were digested from pRev\|TRE\|S\|hCNTF expression vector with endonucleases(Hind Ⅲ and BamH Ⅰ),and respected direction and integration of hCNTF cDNA which inserted pRev\|TRE vector were identified; 2.The expression of 24kD CNTF proteins in CNTF\|modified OEC culture supernatant was positively\|correlated with the concentration of doxycline,while no such protein expression was detected in the control groups; 3.The number of surviving RGCs in CNTF\|modified OECs group(41^34?5^4) was significantly higher than those in unmodified OEC(23^15?4^7),OECs(24^55?5^8) and blank(16^8?6^5) groups;and 4^The neurites of DRG were longer (660?67?m) and denser in CNTF\|modified OECs group,as compared with unmodified OECs(418?45?m),Mock+OECs(400?65?m) and blank (0?m) control groups.No process migrated and grew from the tissue mass in blank group.Conclusion\ hCNTF can be expressed in OECs with a doxycline concentration\|dependent manner after transfected via pRev\|TRE\|S\|hCNTF vector,and possesses a marked enhancing effect on the survival and neurite outgrowth of cultured neurons.[