Trafficking circuit of CD8+ T cells between the intestine and bone marrow governs antitumour immunity.

Immunotherapy elicits a systemic antitumour immune response in peripheral circulating T cells. However, the T cell trafficking circuit between organs and their contributions to antitumour immunity remain largely unknown. Here we show in multiple mouse leukaemia models that high infiltration of leukaemic cells in bone marrow (BM) stimulates the transition of CD8+CD44+CD62L+ central memory T cells into CD8+CD44-CD62L- T cells, designated as inter-organ migratory T cells (TIM cells). TIM cells move from the BM to the intestine by upregulating integrin ß7 and downregulating C-X-C motif chemokine receptor 3 during leukaemogenesis. Upon immunogenic chemotherapy, these BM-derived TIM cells return from the intestine to the BM through integrin α4-vascular cell adhesion molecule 1 interaction. Blocking C-X-C motif chemokine receptor 3 function boosts the immune response against leukaemia by enhancing T cell trafficking. This phenomenon can also be observed in patients with leukaemia. In summary, we identify an unrecognized intestine-BM trafficking circuit of T cells that contributes to the antitumour effects of immunogenic chemotherapy.

CAR-Aptamers Enable Traceless Enrichment and Monitoring of CAR-Positive Cells and Overcome Tumor Immune Escape.

Chimeric antigen receptor (CAR)-positive cell therapy, specifically with anti-CD19 CAR-T (CAR19-T) cells, achieves a high complete response during tumor treatment for hematological malignancies. Large-scale production and application of CAR-T therapy can be achieved by developing efficient and low-cost enrichment methods for CAR-T cells, expansion monitoring in vivo, and overcoming tumor escape. Here, novel CAR-specific binding aptamers (CAR-ap) to traceless sort CAR-positive cells and obtain a high positive rate of CAR19-T cells is identified. Additionally, CAR-ap-enriched CAR19-T cells exhibit similar antitumor capacity as CAR-ab (anti-CAR antibody)-enriched CAR-T cells. Moreover, CAR-ap accurately monitors the expansion of CAR19-T cells in vivo and predicts the prognosis of CAR-T treatment. Essentially, a novel class of stable CAR-ap-based bispecific circular aptamers (CAR-bc-ap) is constructed by linking CAR-ap with a tumor surface antigen (TSA): protein tyrosine kinase 7 (PTK7) binding aptamer Sgc8. These CAR-bc-aps significantly enhance antitumor cytotoxicity with a loss of target antigens by retargeting CAR-T cells to the tumor in vitro and in vivo. Overall, novel CAR-aptamers are screened for traceless enrichment, monitoring of CAR-positive cells, and overcoming tumor cell immune escape. This provides a low-cost and high-throughput approach for CAR-positive cell-based immunotherapy.

Anti-CD79b/CD3 bispecific antibody combined with CAR19-T cells for B-cell lymphoma treatment.

CD19 CAR-T (chimeric antigen receptor-T) cell immunotherapy achieves a remission rate of approximately 70% in recurrent and refractory lymphoma treatment. However, the loss or reduction of CD19 antigen on the surface of lymphoma cells results in the escape of tumor cells from the immune killing of CD19 CAR-T cells (CAR19-T). Therefore, novel therapeutic strategies are urgently required. In this study, an anti-CD79b/CD3 bispecific antibody (BV28-OKT3) was constructed and combined with CAR19-T cells for B-cell lymphoma treatment. When the CD19 antigen was lost or reduced, BV28-OKT3 redirected CAR19-T cells to CD79b+ CD19- lymphoma cells; therefore, BV28-OKT3 overcomes the escape of CD79b+ CD19- lymphoma cells by the killing action of CAR19-T cells in vitro and in vivo. Furthermore, BV28-OKT3 triggered the antitumor function of CAR- T cells in the infusion product and boosted the antitumor immune response of bystander T cells, markedly improving the cytotoxicity of CAR19-T cells to lymphoma cells in vitro and in vivo. In addition, BV28-OKT3 elicited the cytotoxicity of donor-derived T cells toward lymphoma cells in vitro, which depended on the presence of tumor cells. Therefore, our findings provide a new clinical treatment strategy for recurrent and refractory B-cell lymphoma by combining CD79b/CD3 BsAb with CAR19-T cells.

Strategies to optimize chimeric antigen receptor T-cell therapy in hematologic malignancies: Chinese experience.

Chimeric antigen receptor (CAR) T-cell therapy has emerged as a promising form of adoptive T-cell immunotherapy for selected hematologic malignancies including leukemia, lymphoma and multiple myeloma. China has become the country with the largest number of registered CAR T-cell trials. Despite the remarkable clinical outcomes achieved with CAR Tcell therapy, challenges such as disease relapse, the process of manufacturing the CAR T cells and safety have limited the therapeutic efficacy of CAR T cells in hematologic malignancies. In this period of innovation, several clinical trials have reported the design of CAR directed at new targets in hematologic malignancies. In this review, we comprehensively summarize the contemporary landscape and clinical development of CAR T-cell therapy in China. In addition, we present strategies for further improving the clinical utility of CAR T-cell therapy, such as increasing the efficacy and response duration, in hematologic malignancies.

Dnmt3a is downregulated by Stat5a and mediates G0/G1 arrest by suppressing the miR-17-5p/Cdkn1a axis in Jak2V617F cells.

BACKGROUND: Despite of the frequently reported Dnmt3a abormality in classical myeloproliferative neoplasms (cMPNs) patients, few research explores how the Dnmt3a is regulated by Jak2V617F mutation. In this study, we have investigated how the Dnmt3a is regulated by Jak2V617F mutation and its effects on downstream signaling pathways in cMPNs. METHODS: Specimens of Jak2V617F positive cMPN patients and normal controls were collected. Murine BaF3 cell line was used to construct cell models. Dual-Glo luciferase assays and chromatin immunoprecipitation (ChIP)-qPCR were performed to detect the impact of Stat5a on transcription activity of Dnmt3a. Soft agar colony formation assay and cell counting assay were performed to detect cell proliferation. BrdU staining and flow cytometry were used to investigate cell cycle distribution. Western blotting and quantitative reverse-transcription PCR (qPCR) were performed to detect the expression levels of genes. RESULTS: Firstly, the results of western blotting and qPCR revealed that compared with the control samples, Dnmt3a is downregulated in Jak2V617F positive samples. Then we explored the mechanism behind it and found that Dnmt3a is a downstream target of Stat5a, the transcription and translation of Dnmt3a is suppressed by the binding of aberrantly activated Stat5a with Dnmt3a promoter in Jak2V617F positive samples. We further revealed the region approximately 800 bp upstream of the first exon of the Dnmt3a promoter, which includes a gamma-activated sequence (GAS) motif of Stat5a, is the specific site that Stat5a binds to. Soft agar colony formation assay, cell counting assay, and BrdU staining and flow cytometry assay found that Dnmt3a in Jak2V617F-BaF3 cells significantly affected the cell proliferation capacity and cell cycle distribution by suppressing Cdkn1a via miR-17-5p/Cdkn1a axis and mediated G0/G1 arrest. CONCLUSIONS: Transcription and translation of Dnmt3a is downregulated by the binding of Stat5a with Dnmt3a promoter in Jak2V617F cells. The GAS motif at promoter of Dnmt3a is the exact site where the Stat5a binds to. Dnmt3a conducted G0/G1 arrest through regulating miR-17-5p/Cdkn1a axis. The axis of Stat5a/Dnmt3a/miR-17-5p/Cdkn1a potentially provides a treatment target for cMPNs.

A comprehensive genome-wide analysis of long non-coding RNA and mRNA expression profiles of JAK2V617F-positive classical myeloproliferative neoplasms.

Aberrant expression of long non-coding RNAs (lncRNAs) is involved in the progression of myeloid neoplasms, but the role of lncRNAs in the JAK2V617F-positive subtype of classical myeloproliferative neoplasms (cMPNs) remains unclear. This study was conducted to clarify the expression and regulation patterns of lncRNAs in JAK2V617F-positive cMPNs, and to explore new potential carcinogenic factors of cMPNs. Bioinformatics analysis of microarray detection and wet testing verification were performed to study the expression and regulation signature of differentially expressed lncRNAs (DELs) and related genes (DEGs) in cMPNs. The expression of lncRNAs and mRNAs were observed to significantly dysregulated in JAK2V617F-positive cMPN patients compared with the normal controls. Co-expression analysis indicated that there were significant differences of the co-expression pattern of lncRNAs and mRNAs in JAK2V617F-positive cMPN patients compared to normal controls. GO and KEGG pathway analysis of DEGs and DELs showed the involvement of several pathways previously reported to regulate the pathogenesis of leukemia and cMPNs. Cis- and trans-regulation analysis of lncRNAs showed that ZNF141, DHX29, NOC2L, MAS1L, AFAP1L1, and CPN2 were significantly cis-regulated by lncRNA ENST00000356347, ENST00000456816, hsa-mir-449c, NR_026874, TCONS_00012136, uc003lqp.2, and ENST00000456816, respectively, and DELs were mostly correlated with transcription factors including CTBP2, SUZ12, REST, STAT2, and GATA4 to jointly regulate multiple target genes. In summary, expression profiles of lncRNAs and mRNAs were significantly altered in JAK2V617F-positive cMPNs, the relative signaling pathway, co-expression, cis- and trans-regulation were regulated by dysregulation of lncRNAs and several important genes, such as ITGB3, which may act as a promising carcinogenic factor, warrant further investigation.

Long noncoding RNA BS-DRL1 modulates the DNA damage response and genome stability by interacting with HMGB1 in neurons.

Long noncoding RNAs (lncRNAs) are known to regulate DNA damage response (DDR) and genome stability in proliferative cells. However, it remains unknown whether lncRNAs are involved in these vital biological processes in post-mitotic neurons. Here, we report and characterize a lncRNA, termed Brain Specific DNA-damage Related lncRNA1 (BS-DRL1), in the central nervous system. BS-DRL1 is a brain-specific lncRNA and depletion of BS-DRL1 in neurons leads to impaired DDR upon etoposide treatment in vitro. Mechanistically, BS-DRL1 interacts with HMGB1, a chromatin protein that is important for genome stability, and is essential for the assembly of HMGB1 on chromatin. BS-DRL1 mediated DDR exhibits cell-type specificity in the cortex and cerebellum in gamma-irradiated mice and BS-DRL1 knockout mice show impaired motor function and concomitant purkinje cell degeneration. Our study extends the understanding of lncRNAs in DDR and genome stability and implies a protective role of lncRNA against neurodegeneration.

Donor-derived CD19 CAR-T cell therapy of relapse of CD19-positive B-ALL post allotransplant.

Safety and efficacy of allogeneic anti-CD19 chimeric antigen receptor T cells (CAR-T cells) in persons with CD19-positive B-cell acute lymphoblastic leukemia (B-ALL) relapsing after an allotransplant remain unclear. Forty-three subjects with B-ALL relapsing post allotransplant received CAR-T cells were analyzed. 34 (79%; 95% confidence interval [CI]: 66, 92%) achieved complete histological remission (CR). Cytokine release syndrome (CRS) occurred in 38 (88%; 78, 98%) and was ≥grade-3 in 7. Two subjects died from multiorgan failure and CRS. Nine subjects (21%; 8, 34%) developed ≤grade-2 immune effector cell-associated neurotoxicity syndrome (ICANS). Two subjects developed ≤grade-2 acute graft-versus-host disease (GvHD). 1-year event-free survival (EFS) and survival was 43% (25, 62%). In 32 subjects with a complete histological remission without a second transplant, 1-year cumulative incidence of relapse was 41% (25, 62%) and 1-year EFS and survival, 59% (37, 81%). Therapy of B-ALL subjects relapsing post transplant with donor-derived CAR-T cells is safe and effective but associated with a high rate of CRS. Outcomes seem comparable to those achieved with alternative therapies but data from a randomized trial are lacking.

FLT3 inhibition upregulates HDAC8 via FOXO to inactivate p53 and promote maintenance of FLT3-ITD+ acute myeloid leukemia.

Internal tandem duplication (ITD) mutations within the FMS-like receptor tyrosine kinase-3 (FLT3) can be found in up to 25% to 30% of acute myeloid leukemia (AML) patients and confer a poor prognosis. Although FLT3 tyrosine kinase inhibitors (TKIs) have shown clinical responses, they cannot eliminate primitive FLT3-ITD+ AML cells, which are potential sources of relapse. Therefore, elucidating the mechanisms underlying FLT3-ITD+ AML maintenance and drug resistance is essential to develop novel effective treatment strategies. Here, we demonstrate that FLT3 inhibition induces histone deacetylase 8 (HDAC8) upregulation through FOXO1- and FOXO3-mediated transactivation in FLT3-ITD+ AML cells. Upregulated HDAC8 deacetylates and inactivates p53, leading to leukemia maintenance and drug resistance upon TKI treatment. Genetic or pharmacological inhibition of HDAC8 reactivates p53, abrogates leukemia maintenance, and significantly enhances TKI-mediated elimination of FLT3-ITD+ AML cells. Importantly, in FLT3-ITD+ AML patient-derived xenograft models, the combination of FLT3 TKI (AC220) and an HDAC8 inhibitor (22d) significantly inhibits leukemia progression and effectively reduces primitive FLT3-ITD+ AML cells. Moreover, we extend these findings to an AML subtype harboring another tyrosine kinase-activating mutation. In conclusion, our study demonstrates that HDAC8 upregulation is an important mechanism to resist TKIs and promote leukemia maintenance and suggests that combining HDAC8 inhibition with TKI treatment could be a promising strategy to treat FLT3-ITD+ AML and other tyrosine kinase mutation-harboring leukemias.

[Detection of Genetic Mutations in Primary Hypereosinophilia Patients].

OBJECTIVE: To explore the potential pathogenetic mutations of primary hypereosinophilia（HEN）by sequencing FGFR1 FLT3, MPL and JAK2 genes, and to clarify their effect on clinical manifestation and prognosis of HEN patients. METHODS: The direct DNA sequencing was employed to detect the gene mutations of FGFR1, FLT3, MPL and JAK2 in HEN patients. RESULTS: One deletion mutation (2654_2753del) within tyrosine kinase domain of FLT3 gene was found in a patient suffered from severe symptoms and ended with dismal outcome, which induced a premature stop codon (G885fsX888). For FGFR1, a new variation described as 1014_1019del AACAGT for nucleotide change was found in 19 cases, resulting in T339_V340del at the protein level. CONCLUSION: The deletion of 6 bases in the FGFR1 gene (1014_1019del AACAGT) is first reported as non-synonymous SNP (nsSNP) site in the patients with primary hypereosinophilia. Deletion mutations in the FLT3 gene may be related with malignant clinical features and poor prognosis.

Chemotherapy-induced niche perturbs hematopoietic reconstitution in B-cell acute lymphoblastic leukemia.

BACKGROUND: Considerable efforts have been devoted toward the uncovering of the molecular mechanisms underlying the maintenance of hematopoietic stem cells (HSCs) by the normal bone marrow (BM) niche. Previously, we demonstrated that a chemotherapy-induced niche, which is mainly composed of mesenchymal stem cells (MSCs), protects the residual B-cell acute lymphoblastic leukemia (B-ALL) cells from the insult of chemotherapeutic drugs. However, the roles of chemotherapy-induced niche on HSCs functions in B-ALL remain unclear. METHODS: We established an oncogenic N-MYC-driven B-ALL mouse model, which were subsequently treated with common chemotherapy drug cytarabine (Ara-C) and daunorubicin (DNR). After treatment, the structures of the BM niche were imaged by immunofluorescence staining. Then, the self-renewal and differentiation capability of the MSCs in the BM after Ara-C and DNR treatment were studied by ex vivo culture and gene expression analysis with RNA-seq and qRT-PCR. The effects of chemotherapy-induced niche on the hematopoietic reconstitution of HSCs were determined with series transplantation assay. Furthermore, the cell cycle, ROS level, mitochondrial membrane potential and cell apoptosis of HSCs were detected by flow cytometry. RESULTS: The MSCs, which is the main component of chemotherapy-induced BM niche, have decreased self-renewal capability and are prone to differentiate into adipocytes and chondrocytes. The results of gene expression analysis with RNA-seq showed that the MSCs have reduced levels of cytokines, including SCF, CXCL12, ANGPT1, VCAM1, and IL7. Furthermore, the chemotherapy-induced niche perturbed the hematopoietic reconstitution of HSCs in our N-MYC-driven B-ALL mouse model by promoting HSCs to enter cell cycle and increasing intracellular ROS levels and mitochondrial membrane potential of HSCs, which lead to the cell apoptosis of HSCs. CONCLUSIONS: Chemotherapy-induced BM niche perturbs the hematopoietic reconstitution of HSCs by increasing intracellular ROS level and inducing cell apoptosis.

[Clinical Efficacy Comparison of Ultralow Dose of Decitabine and Cyclosporine on Low-risk and Intermediate-risk Type 1 of Myelodysplastic Syndrome].

OBJECTIVE: To evaluate the clinical efficacy and safety of decitabine and cyclosporine for treatment of low-risk and intermediate-risk-1 myelodysplastic syndrome (MDS) patients. METHODS: The clinical data of 27 cases of low risk and intermediate-risk-1 MDS during the past 3 years in Tongji hospital were analyzed retrospectively. These MDS patients were divided into 2 groups: decitabine group (11 cases) and cyclosporine group (16 cases). The MDS patients in the 2 groups were treated with ultra low dose of decitabine and cyclosporine A; the curetive efficacy and adverse reactions were evaluated. RESULTS: In the 11 patients with low-risk and intermediate-risk-1 MDS treated with 2 courses of ultra-low-dose decitabine, 4 cases (36.4%) achieved a hematological improvement, 7 cases (63.6%) showed ineffective, including non-remission in 6 cases (54.5 %) and death in 1 patient (9.1%), total effective rate were 36.4%; 3 cases died within the first year and the overall survival (OS) rate was 72.7%. The causes of death mainly were severe myelosuppression and the associated infection and bleeding. In the 16 patients with low-risk and intermediate-risk-1 MDS treated with cyclosporine (CsA), 10 cases (62.5%) achieved a hematological improvement, 6 cases (37.5%) showed ineffective, the total efficiency of 62.5%; no patients died within 1 year, the 1-year OS was 100%. Changes in neutrophils, hemoglobin and platelet were not significantly different between the two group. CONCLUSION: The clinical efficacy of decitabine on low-risk and intermediate-risk-1 MDS has not confirmed to be superior to cyclosporine (P = 0.252). However, the side effects of serious infection and myelosuppression were more severe in decitabine group than that in the cyclosporine group. Moreover, the 1-year overall survival rate in decitabine group is much lower than that in the cyclosporine group (P = 0.027). In regard to the small number of cases and short follow-up time in our this study, the more patients and longer follow-up time are needed to study.

Colony-stimulating factors for chemotherapy-related febrile neutropenia are associated with improved prognosis in adult acute lymphoblastic leukemia.

Colony-stimulating factors (CSF) have been widely used to prevent febrile neutropenia associated with chemotherapy. Due to the high intensity of chemotherapy in acute lymphoblastic leukemia (ALL), CSF as a crucial component of supportive care has played a significant role in the therapy. However, the effectiveness of CSF in treatment has not been identified by large clinical trials until now. The aim of the present study was to evaluate the effect of CSF on the long-term outcome of adult ALL patients. A comprehensive search strategy has been conducted, which covered the Cochrane Central Register of Controlled Trials, PubMed and Web of Science. The result includes seven randomized controlled trials containing a total of 753 patients. The administration of CSF significantly reduced the mortality at the end of the follow-up (RR, 0.85; 95% CI, 0.75-0.95), the mortality at day 30 (RR, 0.41; 95% CI, 0.23-0.74) and the number of patients with infection or severe infections (RR, 0.8; 95% CI, 0.7-0.9 and RR, 0.48; 95% CI, 0.3-0.75). The addition of CSF also marginally increased the number of patients achieving CR (RR, 1.14; 95% CI, 1.05-1.23). The use of CSF also shortened the duration of neutropenia (median days, 8-17 to 12.5-24). In conclusion, CSFs can be administered to ALL patients during myelosuppressive chemotherapy, particularly in the induction phase.

T-cell-mediated antitumor immunity in B-cell non-Hodgkin lymphoma: activation, suppression and exhaustion.

The tumor microenvironment in B-cell non-Hodgkin lymphoma (NHL) comprises not only malignant cells but also significant numbers of normal immune cells. The intratumoral immune infiltrate includes T-lymphocytes that appear to target the malignant clone. Despite immunologically recognizing the lymphoma cells, the intratumoral T-cells are unable to eradicate the malignant cells and the lymphoma commonly progresses. Recent data has identified mechanisms whereby activated intratumoral T-cells are suppressed or become exhausted due to chronic antigen stimulation. A clearer understanding of these mechanisms will allow for strategies to overcome them and improve the outcome of patients with lymphoma.

Nanocomposite-siRNA approach for down-regulation of VEGF and its receptor in myeloid leukemia cells.

BACKGROUND: Efficient modulation of aberrant vascular endothelial growth factor (VEGF) and its receptor-1 (Flt-1) expressions have become a potential therapeutic strategy for hematologic malignancies including myeloid leukemia. In this study, we explored the safety and efficacy of chitosan nanoparticle siRNA-VEGF and Flt-1 in leukemic U973 cells. METHODS: Cell transfection efficiencies were analyzed by fluorescence microscope, quantitative Real Time PCR; cell growth inhibitory rates were analyzed by CCK-8 assays and flow cytometry. RESULTS: siRNA-coated chitosan nanosphere transfection led to 65%, Lipofectamine 2000 to 50% and adenovirus to 90% transfection efficiencies. Three days after transfection of U973 cells, the siRNA induced gene silencing rates of VEGF and Flt-1 were 68% and 65% in the adenovirus, 45% and 43% in the chitosan nanoparticle group. The cell growth inhibitory rates were 34.73% for VEGF and 27.61% for Flt-1 silencing in the adenovirus and 27.04% for VEGF and 21.49% for Flt-1 silencing in the chitosan nanoparticle group. CONCLUSION: Chitosan nanoparticle siRNA technology can effectively inhibit the expression of VEGF and its receptor in leukemic cells, which led to suppression of their proliferation. Though less efficient than adenoviruses, their non-viral properties suggest that chitosan nanoparticle siRNA complex gene silencing is suitable for further trials.

N-Propionyl polysialic acid precursor enhances the susceptibility of multiple myeloma to antitumor effect of anti-NprPSA monoclonal antibody.

AIM: To study the antitumor effect of anti-NprPSA monoclonal antibody (mAb) in combination with ManNPr, a precursor of N-propionyl PSA, in multiple myeloma (MM), and to explore the mechanisms of the action. METHODS: Human multiple myeloma cell line RPMI-8226 was tested. The cells were pre-treated with ManNPr (1, 2, and 4 mg/mL), and then incubated with anti-NprPSA mAb (1 mg/mL). Cell apoptosis in vitro was detected using MTT assay and flow cytometry. BALB/c nude mice were inoculated sc with RPC5.4 cells. On 5 d after the injection, the mice were administered sc with anti-NprPSA mAb (200 µg/d) and ManNPr (5 mg/d) for 8 d. The tumor size and body weight were monitored twice per week. TUNEL assay was used for detecting apoptosis in vivo. The apoptotic pathway involved was examined using Western blot analysis and caspase inhibitor. RESULTS: Treatment of RPMI-8226 cells with anti-NprPSA mAb alone failed to inhibit cell growth in vitro. In RPMI-8226 cells pretreated with ManNPr, however, the mAb significantly inhibited the cell proliferation, decreased the viability, and induced apoptosis, which was associated with cleavage of caspase-3, caspase-8, caspase-9, and poly(ADP-ribose) polymerase. In the mouse xenograft model, treatment with the mAb in combination with ManNPr significantly inhibited the tumor growth, and induced significant apoptosis as compared to treatment with the mAb alone. Moreover, apoptosis induced by the mAb in vivo resulted from the activation of the caspases and poly(ADP-ribose) polymerase. CONCLUSION: The anti-NprPSA mAb in combination with ManNPr is an effective treatment for in vitro and in vivo induction of apoptosis in multiple myeloma.

Down-regulation of SENP1 expression increases apoptosis of Burkitt lymphoma cells.

OBJECTIVE: To investigate the effect of down-regulation of Sentrin/SUMO-specific protease 1 (SENP1) expression on the apoptosis of human Burkitt lymphoma cells (Daudi cells) and potential mechanisms. METHODS: Short hairpin RNA (shRNA) targeting SENP1 was designed and synthesized and then cloned into a lentiviral vector. A lentiviral packaging plasmid was used to transfect Daudi cells (sh-SENP1-Daudi group). Daudi cells without transfection (Daudi group) and Daudi cells transfected with blank plasmid (sh-NC-Daudi group) served as control groups. Flow cytometry was performed to screen GFP positive cells and semiquantitative PCR and Western blot assays were employed to detect the inference efficiency. The morphology of cells was observed under a microscope before and after transfection. Fluorescence quantitative PCR and Western blot assays were conducted to measure the mRNA and protein expression of apoptosis related molecules (caspase-3, 8 and 9). After treatment with COCl2 for 24 h, the mRNA and protein expression of hypoxia inducible factor -1α (HIF-1α) was determined. RESULTS: Sequencing showed the expression vectors of shRNA targeting SENP1 to be successfully constructed. Following screening of GFP positive cells by FCM, semiqualitative PCR showed the interference efficiency was 79.2±0.026%. At 48 h after transfection, the Daudi cells became shrunken, had irregular edges and presented apoptotic bodies. Western blot assay revealed increase in expression of caspase-3, 8 and 9 with prolongation of transfection (P<0.05). Following hypoxia treatment, mRNA expression of HIF-1α remained unchanged in three groups (P>0.05) but the protein expression of HIF-1α markedly increased (P<0.05). However, in the sh-SENP1-Daudi group, the protein expression of HIF-1α remained unchanged. CONCLUSION: SENP1-shRNA can efficiently inhibit SENP1 expression in Daudi cells. SENP1 inhibition may promote cell apoptosis. These findings suggest that SENP1 may serve as an important target in the gene therapy of Burkitts lymphoma.

CD146 expression correlates with epithelial-mesenchymal transition markers and a poor prognosis in gastric cancer.

CD146 has been regarded as a novel potential therapeutic target for multiple cancers. The aim of the study was to investigate the expression of CD146 in gastric cancer and evaluate its clinical-pathological and prognostic significance. The expression of CD146 and three epithelial-mesenchymal transition (EMT)-related proteins (E-cadherin, ß-catenin and vimentin) was examined in 144 gastric cancers by immunohistochemistry. Fifty-nine cases (41.0%) were defined as positive for CD146 expression. We found that CD146 expression correlated positively with lymph node involvement and a poor prognosis, and retained an independent prognostic factor for gastric cancer patients. Furthermore, positive expression of CD146 was strongly associated with loss of the epithelial marker E-cadherin and acquisition of the expression of the mesenchymal markers nuclear ß-catenin and vimentin. These findings suggest that CD146 might promote EMT and progression in gastric cancer, and thus may be a potential therapeutic target for patients with gastric cancers.

[Preliminary study of biological mechanism and apoptotic effect induced by YM155 in SUDHL-4 cell line].

OBJECTIVE: To explore the apoptotic effect of follicular lymphoma and related mechanism induced by YM155 in vitro and provide laboratory rationales for the clinical treatment of follicular of lymphoma with YM155 in the future. METHODS: SUDHL-4 cells were cultured to logarithmic phase and transferred to 96-well plates. There were a series of YM155 concentration gradients: 100, 10, 1, 0.1 and 0 ng/ml and cultured for 24, 48 and 72 h. After the addition of CCK-8 reagent for 2 h at each time point, optical density values were obtained from the cell growth inhibition curves depending on time and drug concentration and the half growth inhibition concentration (IC(50)) values calculated. SUDHL-4 cells were co-cultured with YM155 (1 ng/ml) for 0, 24, 48 and 72 h respectively. Then flow cytometry (FCM) was used to detect apoptosis. SUDHL-4 cell line was treated with YM155 for 24 and 48 h to extract the total RNA. The mRNA expressions of bcl-2, bcl-xl, bid, bax and survivin gene at the time point of 48 h and the survivin mRNA expression at 24 h were detected by reverse transcription-PCR (RT-PCR). The protein expressions of survivin, caspase-9, cleaved caspase-9, caspase-3 and cleaved caspase-3 were detected at each time point with Western blot respectively. RESULTS: SUDHL-4 cell line showed significant growth inhibition effect depending on time and dose. And the 24, 48, 72 h IC(50) was 6.1, 2.7 and 1.2 ng/ml respectively. SUDHL-4 cells stained AnnexinV-FITC and PI examined by FCM demonstrated that the proportion of AnnexinV-FITC positive cells gradually increased with time (17.3% ± 2.1%, 35.7% ± 3.3%, 54.6% ± 4.3% vs 2.1% ± 0.3%, all P < 0.05). And the results of real-time fluorescent PCR proved that YM155 decreased the expression of survivin gene obviously (24 h: 0.72 ± 0.02, 48 h: 0.56 ± 0.01 vs 1.00, both P < 0.05) but had little effects on the gene expressions of bax, bid, bcl-2 and bcl-xl. The Western blot results further confirmed that the protein expressions of survivin and caspase-3 decreased with time while caspase-9 and cleaved caspase-9 showed no obvious changes. But cleaved caspase-3 increased significantly. CONCLUSIONS: YM155 displays significant apoptotic effects in SUDHL-4 cell lines. The mechanism may be the direct activation of caspase-3 through the down-regulation of survivin. And the apoptotic pathway is probably not regulated by bcl-2 family.