OBJECTIVE: To identify the role of gene silencing or overexpression of Nemo-like kinase (NLK) during the process of neural differentiation of human mesenchymal stem cells (hBMSCs), and to explore the effect of NLK downregulation by transfection of small interfering RNA (siRNA) on promoting neuralized tissue engineered bone regeneration. METHODS: NLK-knockdown hBMSCs were established by transfection of siRNA (the experimental group was transfected with siRNA silencing the NLK gene, the control group was transfected with control siRNA and labeled as negative control group), and NLK-overexpression hBMSCs were established using lentivirus vector transfection technique (the experimental group was infected with lentivirus overexpressing the NLK gene, the control group was infected with an empty vector lentivirus and labeled as the empty vector group). After neurogenic induction, quantitative real-time polymerase chain reaction (qPCR) was used to detect the expression of neural-related gene, and Western blot as well as immunofluorescence staining about several specific neural markers were used to evaluate the neural differentiation ability of hBMSCs.6-week-old male nude mice were divided into 4 groups: ① β-tricalcium phosphate (β-TCP) group, ② β-TCP+ osteogenic induced hBMSCs group, ③ β-TCP+ siRNA-negative control (siRNA-NC) transfection hBMSCs group, ④ β-TCP+ siRNA-NLK transfection hBMSCs group. Four weeks after the subcutaneous ectopic osteogenesis models were established, the osteogenesis and neurogenesis were detected by hematoxylin-eosin (HE) staining, Masson staining and tissue immunofluorescence assay. Statistical analysis was conducted by independent sample t test. RESULTS: After gene silencing of NLK by siRNA in hBMSCs, neural-related genes, including the class Ⅲ β-tubulin (TUBB3), microtubule association protein-2 (MAP2), soluble protein-100 (S100), nestin (NES), NG2 proteoglycan (NG2) and calcitonin gene-related peptide (CGRP), were increased significantly in NLK-knockdown hBMSCs compared with the negative control group(P < 0.05), and the expression levels of TUBB3 and MAP2 of the NLK silencing group were also increased. Oppositely, after NLK was overexpressed using lentivirus vector transfection technique, TUBB3, MAP2, S100 and NG2 were significantly decreased in NLK-overexpression hBMSCs compared with the empty vector group (P < 0.05), and the expression level of TUBB3 was also decreased. 4 weeks after the subcutaneous ectopic osteogenesis model was established, more mineralized tissues were formed in the β-TCP+ siRNA-NLK transfection hBMSCs group compared with the other three groups, and the expression of BMP2 and S100 was higher in the β-TCP+ siRNA-NLK transfection hBMSCs group than in the other groups. CONCLUSION Gene silencing of NLK by siRNA promoted the ability of neural differentiation of hBMSCs in vitro and promoted neuralized tissue engineered bone formation in subcutaneous ectopic osteogenic models in vivo in nude mice.
Bone Regeneration/genetics* ; Animals ; Mesenchymal Stem Cells/cytology* ; Humans ; RNA, Small Interfering/genetics* ; Tissue Engineering/methods* ; Cell Differentiation ; Mice, Nude ; Gene Silencing ; Mice ; Male ; Protein Serine-Threonine Kinases/genetics* ; Intracellular Signaling Peptides and Proteins/genetics* ; Transfection ; Cells, Cultured ; Lentivirus/genetics*

Metachromatic leukodystrophy (MLD) is an inherited disease caused by a deficiency of the enzyme arylsulfatase A (ARSA). Lentivirus-modified autologous hematopoietic stem cell gene therapy (HSCGT) has recently been approved for clinical use in pre and early symptomatic children with MLD to increase ARSA activity. Unfortunately, this advanced therapy is not available for most patients with MLD who have progressed to more advanced symptomatic stages at diagnosis. Patients with late-onset juvenile MLD typically present with a slower neurological progression of symptoms and represent a significant burden to the economy and healthcare system, whereas those with early onset infantile MLD die within a few years of symptom onset. We conducted a pilot study to determine the safety and benefit of HSCGT in patients with postsymptomatic juvenile MLD and report preliminary results. The safety profile of HSCGT was favorable in this long-term follow-up over 9 years. The most common adverse events (AEs) within 2 months of HSCGT were related to busulfan conditioning, and all AEs resolved. No HSCGT-related AEs and no evidence of distorted hematopoietic differentiation during long-term follow-up for up to 9.6 years. Importantly, to date, patients have maintained remarkably improved ARSA activity with a stable disease state, including increased Functional Independence Measure (FIM) score and decreased magnetic resonance imaging (MRI) lesion score. This long-term follow-up pilot study suggests that HSCGT is safe and provides clinical benefit to patients with postsymptomatic juvenile MLD.
Humans ; Leukodystrophy, Metachromatic/genetics* ; Pilot Projects ; Genetic Therapy/methods* ; Hematopoietic Stem Cell Transplantation ; Male ; Follow-Up Studies ; Female ; Lentivirus/genetics* ; Child ; Child, Preschool ; Hematopoietic Stem Cells/metabolism* ; Cerebroside-Sulfatase/metabolism* ; Adolescent

Objective To establish a stable strain of H9c2 cardiomyocytes overexpressing Cx40 and preliminarily investigate the effect of lentiviral vector-mediated Cx40 protein overexpression on the proliferation of H9c2 cells and its related mechanisms. Methods The Cx40 gene fragment was cloned from H9c2 cells by PCR and linked with lentivirus vector pLVX-IRES-Puro to obtain the recombinant plasmid pLVX-Flag-Cx40. Recombinant lentiviral particles carrying Flag-Cx40 were obtained by cotransfection with packaging plasmids into HEK293T cells. A stable expression strain (H9c2-Flag-Cx40 cell) was screened from infected H9c2 cells by purinomycin. The expression of Cx40 protein was detected by Western blot analysis, and the effect of Cx40 on H9c2 cells proliferation was determined by CCK-8 assay; cell cycle changes were measured by flow cytometry; the expression of the cell cycle protein cyclin D1 was detected by qRT-PCR and Western blot analysis. Co-immunoprecipitation (Co-IP) immunoprecipitation and Western blot analysis were used to identify the binding of Cx40 and Yes associated protein (YAP) in H9c2 cells; cytoplasmic and cytosolic proteins were isolated to detect the effect of Cx40 on the localization of YAP using Western blot analysis. Results Sequencing results showed that the recombinant pLVX-Flag-Cx40 expression vector was successfully established. A stable transfected cell line containing recombinant Flag-Cx40 lentivirus (H9c2-Flag-Cx40 cell) was successfully constructed from H9c2 cells. Compared with the control group, overexpression of Cx40 significantly reduced the proliferation of H9c2 cells, arrested the cell cycle at G0/G1 and reduced cyclin D1 expression. A significant increase in YAP expression was observed in the cytoplasm of the H9c2-Flag-Cx40 stable cell line, while the expression in the nucleus was significantly reduced. Cx40 bound to YAP in the cytoplasm and prevented it from entering the nucleus to play the role of transcriptional coactivation. Conclusion Overexpression of Cx40 induces cell-cycle arrest at G0/G1 phase and inhibits the proliferation in H9c2 cells.
Rats ; Humans ; Animals ; Cyclin D1/genetics* ; Transfection ; Myocytes, Cardiac ; HEK293 Cells ; Cell Cycle Checkpoints/genetics* ; Cell Proliferation/genetics* ; Lentivirus/genetics* ; Genetic Vectors/genetics* ; Gap Junction alpha-5 Protein

OBJECTIVE: To screen better promoters and provide more powerful tools for basic research and gene therapy of hemophilia. METHODS: Bioinformatics methods were used to analyze the promoters expressing housekeeping genes with high abundance, so as to select potential candidate promoters. The GFP reporter gene vector was constructed, and the packaging efficiency of the novel promoter was investigated with EF1 α promoter as control, and the transcription and activities of the reporter gene were investigated too. The activity of the candidate promoter was investigated by loading F9 gene. RESULTS: The most potential RPS6 promoter was obtained by screening. There was no difference in lentiviral packaging between EF1 α-LV and RPS6-LV, and their virus titer were consistent. In 293T cells, the transduction efficiency and mean fluorescence intensity of RPS6pro-LV and EF1 αpro-LV were proportional to the lentiviral dose. The transfection efficiency of both promoters in different types of cells was in the following order: 293T>HEL>MSC; Compared with EF1 αpro-LV, RPS6pro-LV could obtain a higher fluorescence intensity in MSC cells, and RPS6pro-LV was more stable in long-term cultured HEL cells infected with two lentiviruses respectively. The results of RT-qPCR, Western blot and FIX activity (FIX∶C) detection of K562 cell culture supernatant showed that FIX expression in the EF1 α-F9 and RPS6-F9 groups was higher than that in the unloaded control group, and there was no significant difference in FIX expression between the EF1 α-F9 and RPS6-F9 groups. CONCLUSION After screening and optimization, a promoter was obtained, which can be widely used for exogenous gene expression. The high stability and viability of the promoter were confirmed by long-term culture and active gene expression, which providing a powerful tool for basic research and clinical gene therapy of hemophilia.
Humans ; Transduction, Genetic ; Genetic Vectors ; Hemophilia A/genetics* ; Transfection ; Blood Coagulation Factors/genetics* ; Lentivirus/genetics*

OBJECTIVE: In order to conduct high-throughput genome-wide translocation sequencing based on CRISPR/Cas9, Nalm6-cas9 monoclonal cell line expressing Cas9 protein was constructed by lentivirus transduction. METHODS: Lentiviral vectors LentiCas9-Blast, pSPAX2, and pMD2.G were used to co-transfect HEK293T cells to obtain recombinant lentivirus. After Nalm6 cells were infected with the recombinant lentivirus, the cells were screened by Blasticidin, and multiple monoclonal cell lines expressing Cas9 protein were obtained by limited dilution. Western blot was used to detect the expression level of Cas9 protein in monoclonal cell lines, and cell count analysis was used to detect the proliferation activity of monoclonal cell lines. LentiCRISPRV2GFP-Δcas9, LentiCRISPRV2GFP-Δcas9-AF4, LentiCRISPRV2GFP-Δ cas9-MLL plasmids were constructed, and transfected with pSPAX2 and pMD2.G, respectively. T vector cloning was used to detect the function of Cas9 protein in Nalm6-Cas9 monoclonal cell line infected with virus. RESULTS: Western blot showed that Nalm6-Cas9_1-6 monoclonal cell line had high expression of Cas9 protein. Cell count analysis showed that high expression of Cas9 protein in Nalm6-Cas9_1-6 monoclonal cell line did not affect cell proliferation activity. The Nalm6-Cas9_1-6 monoclonal cell line had high cleavage activity, and the editing efficiency of AF4 and MLL genes was more than 90% which was determined by T vector cloning. CONCLUSION Nalm6-Cas9_1-6 monoclonal cell line stably expressing highly active Cas9 protein was obtained, which provided a basis for exploring the translocation of MLL in therapy-related leukemias based on CRISPR/Cas9 genome-wide high-throughput genome-wide translocation sequencing.
CRISPR-Associated Protein 9/genetics* ; CRISPR-Cas Systems ; Genetic Vectors ; HEK293 Cells ; Humans ; Lentivirus/genetics* ; Plasmids

Long non-coding RNA (lncRNA) has become an important regulator of many cellular processes, including cell proliferation. Although studies have shown that a variety of lncRNAs play an important role in the occurrence and development of hematopoietic malignancies, a more comprehensive and unbiased method to study the function of lncRNAs in leukemia cell lines is lacking. Here, we used short hairpin RNA (shRNA) library combined with high-throughput sequencing to screen lncRNAs that may affect the proliferation of leukemia cell lines, and identified lncRNA C20orf204-203 among 74 candidate lncRNAs in this study. Further experiments showed that C20orf204-203 was localized in the cytoplasm in both K562 and THP-1 cell lines. C20orf204-203 knockdown decreased the proliferation of K562 and THP-1 cell lines accompanied with the increased proportion of early apoptotic cells. We observed the increased mRNA level of BAD gene while decreased protein level of TP53 and BCL2. The expression of Caspase 3 decreased and Caspase 3-cleaved protein increased in THP-1 cell line. However, their changes were inconsistent in the two cell lines. Our experimental results showed that knockdown of lncRNA C20orf204-203 in leukemia cell lines affected cell proliferation although the mechanism of action in different cell lines may differ. Importantly, our research demonstrated the feasibility of using shRNA library combined with high-throughput sequencing to study the role of lncRNA in leukemia cell lines on a large scale.
Caspase 3 ; Cell Line, Tumor ; Cell Proliferation/genetics* ; Humans ; Lentivirus/genetics* ; Leukemia/genetics* ; Proto-Oncogene Proteins c-bcl-2 ; RNA, Long Noncoding/metabolism* ; RNA, Messenger ; RNA, Small Interfering/genetics*

OBJECTIVE: To construct a HEK293 cell line stably overexpressing TrxR1 as a cell model for functional study of TrxR1 and screening of TrxR1-targeting drugs. METHODS: TrxR1 gene was amplified by PCR and ligated with the lentivirus expression vector pLVX-Puro, which was transformed into Escherichia coli and identified by Sanger dideoxy sequencing. HEK293 cells were infected with the recombinant lentivirus vector (pLVX-Puro-TXNRD1) and screened with Puromycin for cell clones with stable TrxR1 overexpression (HEK293-TrxR1-OE cells). HEK293-TrxR1-OE cells, along with HEK293 cells infected with pLVX-Puro vector (HEK293-NC) and normal HEK293 cells, were tested for mRNA and protein expression levels of TrxR1 using RT-qPCR and Western blotting. TrxR1 enzyme activity in the cells was evaluated with insulin endpoint assay and TRFS-green probe imaging. The sensitivity of the cells to auranofin, a specific TrxR1 inhibitor, was determined with CCK8 assay. RESULTS: TrxR1 gene was successfully inserted into the lentiviral vector pLVX-Puro as confirmed by DNA sequencing. The enzyme activity and mRNA and protein expression levels of TrxR1 were significantly higher in HEK293-TrxR1-OE cells than in HEK293 and HEK293-NC cells (P < 0.005). The inhibitory effects of auranofin on proliferation and cellular TrxR1 enzyme activity were significantly attenuated in HEK293-TrxR1-OE cells as compared with HEK293 and HEK293-NC cells (P < 0.005). CONCLUSION We successfully obtained a HEK293 cell line with stable TrxR1 overexpression, which shows resistance to auranofin and can be used for screening TrxR1 targeting drugs.
Auranofin ; Cell Line, Tumor ; Genetic Vectors ; HEK293 Cells ; Humans ; Lentivirus/genetics* ; RNA, Messenger ; Transfection

OBJECTIVE: To provide a research basis for a safe and effective cell therapy for β-thalassemia through optimization of HS4 region of the third generation lentiviral vector for stable expression of β-globin. METHODS: The human β-globin HS4 region in the third generation lentiviral expression vector was optimized to construct the lenti-HBB, and the transcription and translation of β-globin gene were analyzed by RT-PCR and Western blot after the transduction of lenti-HBB in MEL cell line. Furthermore, the erythroid differentiation of CD34⁺ cells which were transduced lentiviral virus carrying human β-globin from normal human umbilical cord blood cells and peripheral blood cells of patients with β-thalassemia major were confirmed by colony formation assay, cell smear assay and flow cytometry. The safety and effectiveness of the optimized lenti-HBB were verified by NSG mouse in vivo test. RESULTS: The human β-globin was expressed stably in the MEL cells, and CD34⁺ cells from health umbilical cord blood as well as PBMC from patient with β-thalassemia major transduced with lenti-HBB could be differentiated to mature red blood cells. The β-globin expression and differentiation in CD34⁺ cells were demonstrated successfully in the NSG mouse for about 35 months after post-transplant. CONCLUSION Stable β-globin expression through the optimization of HS4 from CD34⁺ in the third generation lentiviral vector is safe and effective for patients with severe β-thalassemia and other β-globin abnormal diseases.
Animals ; Genetic Therapy ; Genetic Vectors ; Humans ; Lentivirus/genetics* ; Leukocytes, Mononuclear ; Mice ; beta-Globins/genetics* ; beta-Thalassemia/therapy*

Objective: This study aimed to create a type of CAR-T cells that targets LMP1 antigen and study its immunotherapeutic effect on LMP1-positive hematological malignancies. Methods: To generate LMP1 CAR-T cells, a plasmid expressing LMP1 CAR was created using molecular cloning technology, and T cells were infected with LMP1 CAR lentivirus. The effects of LMP1 CAR-T cells on specific cytotoxicity against LMP1-positive tumor cell lines infected with the EB virus had been confirmed. Results: ① LMP1 protein expressing on EB virus-positive lymphoma cells surface was verified. ② The LMP1 CAR-expressing plasmid was created, and LMP1 CAR-T cells were obtained by infecting T cells with a lentivirus packaging system, with an infection efficiency of more than 80% . ③LMP1 CAR-T cells have a 4∶1 effect-to-target ratio in killing LMP1-positive lymphoma cells. The killing effect of LMP1 CAR-T cells on Raji cells was enhanced after 48 h of coculture, but there was no significant killing effect on Ramos, which are LMP1-negative lymphoma cells. ④After coculture with LMP1-positive lymphoma cells at a ratio of 1∶1 for 5 h, the degranulation effect was enhanced. The proportion of CD107a(+) T cells in the LMP1 CAR-T cell treatment group was significantly higher than that in the vector-T cell group [ (13.25±2.94) % vs (1.55±0.05) % , t=3.972, P=0.017]. ⑤After coculture with LMP1-positive lymphoma cells, the proportion of CD69(+) and CD25(+) T cells in the LMP1 CAR-T cell group was significantly higher than that in vector-T cell group [ (7.40±0.41) % vs (3.48±0.47) % , t=6.268, P=0.003; (73.00±4.73) % vs (57.67±2.60) % , t=2.842, P=0.047]. ⑥After coculture with LMP1-positive lymphoma cells, cytokine secretion in the LMP1 CAR-T cell group was higher than that in the vector-T cell group [interferon-gamma: (703±73) ng/L vs (422±87) ng/L, t=2.478, P=0.068; tumor necrosis factor-alpha: (215±35) ng/L vs (125±2) ng/L, t=2.536, P=0.064]. Conclusion: In this study, we found that the LMP1 protein is only found on the surface of the EBV-positive tumor cell. Simultaneously, we created an LMP1 CAR-expressing plasmid and obtained LMP1 CAR-T cells by infecting T cells with a lentivirus packaging system. Furthermore, we demonstrated that LMP1 CAR-T cells could specifically kill LMP1-positive tumor cells in vitro. The degranulation and activation effects of LMP1 CAR-T cells were enhanced after coculture with LMP1-positive tumor cells, indicating a potential clinical application.
Cell Line, Tumor ; Herpesvirus 4, Human ; Humans ; Lentivirus ; Lymphoma/therapy* ; Receptors, Chimeric Antigen/genetics* ; T-Lymphocytes ; Viral Matrix Proteins

Objective: To construct chimeric antigen receptor (CAR) T cells targeting CD52 (CD52 CAR-T) and validate the effect of CD52 CAR-T cells on CD52-positive leukemia. Methods: A second-generation CD52-targeting CAR bearing 4-1BB costimulatory domain was ligated into a lentiviral vector through molecular cloning. Lentivirus was prepared and packaged by 293 T cells with a four-plasmid system. Fluorescein was used to label cell surface antigens to evaluate the phenotype of CD52 CAR-T cells after infection. Flow cytometry and ELISA were used to evaluate the specific cytotoxicity of CD52 CAR-T cells to CD52-positive cell lines in vitro. Results: ①A pCDH-CD52scFv-CD8α-4-1BB-CD3ζ-GFP expressing plasmid was successfully constructed and used to transduce T cells expressing a novel CD52-targeting CAR. ②On day 6, CD52-positive T cells were almost killed by CD52-targeted CAR-T post lentivirus transduction [CD52 CAR-T (4.48 ± 4.99) %, vs Vector-T (56.58±19.8) %, P=0.011]. ③T cells transduced with the CAR targeting CD52 showed low levels of apoptosis and could be expanded long-term ex vivo. ④The CD52 CAR could promote T cell differentiation into central and effector memory T cells, whereas the proportion of T cells with a CD45RA(+) effector memory phenotype were reduced. ⑤CD52 CAR-T cells could specifically kill CD52-positive HuT78-19t cells but had no killing effect on CD52-negative MOLT4-19t cells. For CD52 CAR-T cells, the percentage of residual of HuT78-19t cells was (2.66±1.60) % at an the E:T ratio of 1∶1 for 24 h, while (56.66±5.74) % of MOLT4-19t cells survived (P<0.001) . ⑥The results of a degranulation experiment confirmed that HuT78-19t cells significantly activated CD52 CAR-T cells but not MOLT4-19t cells[ (57.34±11.25) % vs (13.06± 4.23) %, P<0.001]. ⑦CD52 CAR-T cells released more cytokines when co-cultured with HuT78-19t cells than that of vector-T cells [IFN-γ: (3706±226) pg/ml, P<0.001; TNF-α: (1732±560) pg/ml, P<0.01]. Conclusions: We successfully prepared CD52 CAR-T cells with anti-leukemia effects, which might provide the foundation for further immunotherapy.
CD52 Antigen ; Cell Line, Tumor ; Humans ; Immunotherapy, Adoptive/methods* ; Lentivirus/genetics* ; Leukemia ; Receptors, Antigen, T-Cell ; Receptors, Chimeric Antigen/genetics*