Irradiation of peripheral blood mononuclear cells with 7.5 Gy X-rays prior to donor lymphocyte infusion inhibits proliferation while preserving cytotoxicity, and improves the effectiveness of HSCT in patients with hematological malignancies.

The aim of the present study was to explore the effect of different X-ray doses on the proliferation and cytotoxic activity of peripheral blood mononuclear cells (PBMCs), particularly lymphocytes, in order to assess whether this reduces the incidence of graft vs. host disease (GVHD) while preserving the graft vs. tumor (GVT) effect in patients with hematological malignancies following hematopoietic stem cell transplantation (HSCT). PBMCs from healthy donors were irradiated with X-rays at doses of 0, 2.5, 5, 7.5, 10, 15, 25 or 50 Gy, and their proliferative activity was determined using a WST-8 assay kit. The cytotoxic activity of non-irradiated PBMCs and PBMCs irradiated with 7.5 Gy X-rays was tested in the leukemic cell line K562 and its Adriamycin-resistant strain K562A using a lactate dehydrogenase assay. The clinical data of 7 patients who received 7.5 Gy X-ray-irradiated PBMC infusions following autologous HSCT were analyzed. PBMCs irradiated with ≥7.5 Gy X-rays exhibited a complete inhibition of proliferation. PBMCs irradiated with 7.5 Gy X-rays exhibited significantly increased cytotoxic activity towards K562 cells compared with K562A cells (P<0.05). There was no significant difference in cytotoxicity between irradiated and non-irradiated PBMCs, irrespective of the target cell, K562 or K562A (P>0.05). Based on the in vitro data, clinical data from patients who received 7.5 Gy X-ray-irradiated PBMC infusions following HSCT between January 2005 and January 2013 were assessed retrospectively. A total of 7 patients were included in the current study. The majority achieved various degrees of remission following donor lymphocyte infusion (DLI) and none suffered from GVHD. This indicates that 7.5 Gy-irradiated PMBCs have a potential application in DLI for the treatment of patients following HSCT. However, further studies on larger patient cohorts are required to assess the clinical potential of 7.5 Gy-irradiated PBMCs for preserving the GVT effect while avoiding GVHD following HSCT.

Allogeneic Compact Bone-Derived Mesenchymal Stem Cell Transplantation Attenuates the Severity of Idiopathic Pneumonia Syndrome in a Murine Bone Marrow Transplantation Model.

BACKGROUND/AIMS: Idiopathic pneumonia syndrome (IPS) is a serious and life-threatening lung complication following allogeneic hematopoietic stem cell transplantation (allo-HSCT) and currently no effective therapies exist. This study was designed to determine whether transplantation of allogeneic murine compact bone derived- mesenchymal stem cells (CB-MSCs) could prevent the development of IPS. METHODS: We tested the effects of CB-MSCs transplantation on IPS using an established murine model of C57BL/6 (H-2b)→BALB/c (H-2d). Survival rates, body weight change, clinical GVHD scores, lung histological changes were assessed after IPS induction. Mechanistically, concentrations of cytokines (TNF-α, IFN-γ and IL-4) and chemokines (CCL5, CXCL9 and CXCL10) in bronchoalveolar lavage fluid (BALF) from the recipient mice were measured at different time point post-transplantation. CD4+CD25+Foxp3+ regulatory T cell (Treg) percentage, CCR5, CXCR3 and CCR7 expression on CD3+ T cells, and lung CXCR3, CCR5, CCR7, T-bet and GATA-3 mRNA levels were also evaluated at different time point post-transplantation. RESULTS: Co-transplantation of CB-MSCs significantly attenuated the severity of lung injuries and increased survival rate of mice compared to non-cotransplanted mice. A higher Treg percentage, reduction of TNF-α, IFN-γ, CCL5, CXCL9 and CXCL10 levels, down-regulation of CXCR3 and CCR5, as well as up-regulation of CCR7, were observed in MSCs co-transplantation mice. Also, the prophylactic effect of CB-MSCs was associated with a shift of Th1/Th2 balance toward anti-inflammatory Th2 polarization. CONCLUSIONS: Allogeneic CB-MSCs effectively controlled the occurrence of IPS due to its profound immunomodulatory capacity. This may offer a novel prophylactic approach for IPS after allo-HSCT.

Prophylaxis of acute graft-versus-host disease by CCR5 blockade combined with cyclosporine A in a murine model.

OBJECTIVE: One characteristic feature of graft-versus-host disease (GVHD) is lymphocytes' trafficking and recruitment to target tissues, and CCR5 plays a key role in the process. Thus, blockade of lymphocytes' chemotaxis may attenuate GVHD. METHODS: We tested the effects of CCR5 blockade using an established murine model. The mean survival time, body weight change, and clinical GVHD scores were assessed. Concentrations of cytokines and chemokines, the CCR5, CXCR3, and CCR7 expressions on T lymphocytes, and histological changes of visceral organs were also evaluated. Additionally, we assessed the immunophenotype of infiltration cells in liver and intestine. RESULTS: Mice undergoing total body irradiation and allogenic hematopoietic stem cell transplantation (allo-HSCT) developed typical GVHD. MVC increased CCR5 expression whereas CCR7 and CXCR3 expression were unaffected. MVC also increased plasma levels of the ligands of CCR5. A combination of MVC with CsA significantly alleviated the degree of visceral injuries and prolonged survival time. CONCLUSION: MVC has a synergistic effect with CsA. It can attenuate the severity of GVHD and increase survival rate of mice in our murine model. This may offer a novel therapeutic perspective for clinical GVHD after allo-HSCT.

In vitro immunological effects of blocking CCR5 on T cells.

Blockade of CC chemokine receptor 5 (CCR5) by maraviroc may induce immunological changes independent of its antiviral effects and may have immunoregulation properties. This study was designed to determine the effects of blocking CCR5 on human activated T cells in vitro and investigate the potential immunological mechanisms. Human CD3+ T cells were purified from peripheral blood mononuclear cells and then activated by cytokines. We tested the surface expressions and relative messenger RNA (mRNA) levels of CCR2, CCR5, CCR6, CCR7, and CXCR3, chemotaxis toward their cognate ligands, internalization of chemokine receptors, and production of cytokines. In conclusion, blocking CCR5 by maraviroc not only can block CCR5 and CCR2 internalization processes induced by CCL5 and CCL2, but also inhibit T cell chemotactic activities toward their cognate ligands, respectively. Moreover, blocking CCR5 with maraviroc at high doses tends to decrease the production of TNF-α and IFN-γ. In addition, there might be a form of cross talk between CCR5 and CCR2, and this may offer a novel immunological effect for blockade of CCR5.

Silencing HCCR2 expression inhibits the proliferation of leukemia cells by inducing apoptosis and promoting cell cycle arrest.

The human cervical cancer oncogene (HCCR2) has been found to be overexpressed in a variety of human malignant tumors cells, and its function is related to cell cycle progression and survival. However, the molecular mechanisms of action of HCCR2 in leukemia remain unclear. In this study, we used the RNA interference strategy to investigate the effects of HCCR2 knockdown in the K562 leukemia cell line, and to explore the potential mechanisms involved. Following transfection with small interfering RNA (siRNA) targeting HCCR2 (HCCR2-siRNA), we examined the effects of HCCR2 knockdown on cell morphology, cell proliferation, cell cycle progression and apoptosis in K562 cells. Morphological changes were evaluated by Wright-Giemsa staining. Cell cycle progression and apoptosis were measured by flow cytometry. The expression levels of genes related to the cell cycle and apoptosis were detected by quantitative RT-PCR (qRT-PCR) and western blot analysis. HCCR2 expression at the mRNA and protein level was significantly decreased following transfection with plasmids expressing HCCR2-siRNA. Silencing HCCR2 expression significantly suppressed cell proliferation, induced G1 cell cycle arrest and promoted the apoptosis of K562 cells. Additionally, we found that the expression of Bax, p53 and p21 was significantly increased, while Bcl-2 expression was significantly decreased in the HCCR2-siRNA-transfected cells. However, the expression of p27 was not affected. These results suggest that the HCCR2 gene plays an important role in the tumorigenesis of leukemia, thus making it an attractive therapeutic target for acute leukemia.

Bortezomib regulates the chemotactic characteristics of T cells through downregulation of CXCR3/CXCL9 expression and induction of apoptosis.

The chemotactic movement of T lymphocytes mediated by chemokines and their receptors plays an important role in the pathogenesis of graft-versus-host disease (GVHD) post-allogeneic hematopoietic stem cell transplantation (allo-HSCT). CCR7 and CXCR3 are two receptors associated with the development of GVHD. Bortezomib, a proteasome inhibitor, was recently found to prevent GVHD in a mouse model and to decrease the production of Th1 cytokines. Here, we report that bortezomib differentially regulates the expression of CXCR3 and CCR7 on T cells; it significantly decreases CXCR3 expression on T cells as well as its CD4(+)/CD8(+) subsets in a dose-dependent manner, while it does not significantly affect CCR7 expression on T cells and subsets. Moreover, the secretion of CXCL9 by activated T cells is also increasingly downregulated with increasing concentrations of bortezomib. Meanwhile, bortezomib inhibits T-cell chemotactic movements toward CXCL9 in a dose-dependent manner, but has no effect on CCL19-induced T-cell chemotaxis. Additionally, it was found that bortezomib treatment also prompts T-lymphocyte apoptosis through activation of caspase-3 and its downstream PARP cleavage in a dose- and time-dependent manner. These results suggest that bortezomib may act as a suppressor of GVHD by downregulating T-cell chemotatic movement toward GVHD target organs, as well as by inducing apoptosis.

[Bone marrow-derived mesenchymal stem cells regulate the proliferation and activity of natural killer cells].

This study was aimed to explore the effect of bone marrow-derived mesenchymal stem cells (MSC) on proliferation and activity of natural killer (NK) and NK-T cells. MSC was co-cultured with peripheral mononuclear cells from healthy donors in presence of IL-2, phytohemagglutinin (PHA) and mouse anti-human CD3 McAb (culture condition known to expand NK cells). The ratio of NK cells and NK-T cells was measured by flow cytometry and the effect of MSC on killing activity of NK cells against K562 cells was detected by MTT method after co-cultured with different densities of MSC. The results showed that MSC inhibited the production of NK cells in a dose-dependent manner generally. At the densities of 0, 1 × 10(5) and 5 × 10(5)/ml, the ratios of NK cells in the co-culture conditions were (16.9 ± 4.6), (14.0 ± 8.6) and (6.4 ± 4.6), respectively (P < 0.05). However, MSC could promote the formation of NK cells at lower MSC density (1 × 10(4)/ml), the ratio of NK cells reached to (20.9 ± 7.1), which was higher than that of culture condition without MSC (P < 0.05). The different densities of MSC in the co-culture conditions had no much influence on the ratio of NK-T cells (P > 0.05). MTT assay showed that the killing activity of suspended cells in co-culture system against K562 cells was parallel with the ratio of NK cells. Different densities of MSC regulated bidirectionally killing activity of NK to K562 cells by regulating bidirectionally ratio of NK cells. It is concluded that the MSC can promote the formation of NK cells and enhance its activity against tumor cells in the lower doses, while suppress the formation of NK cells and attenuate its tumor-killing effect in higher dose condition.

[Effects of quercetin on multidrug resistance and expression of related genes in human erythroleukemic K562/a cells].

The study was aimed to investigate the effect of quercetin, flavonoid molecules on reversing leukemia multidrug resistance and its mechanism. K562/A cells were cultured in vitro with different concentrations of quercetin. Cell growth inhibition and adriamycin (ADR) sensitivity were detected by MTT method. Intracellular ADR concentration was determined by flow cytometry. Cell apoptosis was assayed by Annexin V/PI staining method. The expressions of drug transporter and apoptosis related genes were measured by real-time PCR array. The results indicated that quercetin inhibited the proliferation of K562 and K562/A in 5-160 µmol/L and with dose-dependent manner. Quercetin increased the sensitivity of K562/A cells to ADR in a low toxicity concentration. Flow cytometry showed that the quercetin increased the accumulation of ADR in K562/A cells when cells were co-cultured with 5 µmol/L ADR for 2 hours. Quercetin could induce the apoptosis of K562 and K562/A cells with dose dependent manner. Furthermore, some drug transport related genes such as ATP-binding cassette (ABC) and solute carrier (SLC) and some apoptosis-related genes such as BCL-2, tumor necrosis factor (TNF), tumor necrosis factor receptor (TNFR) families were down-regulated by quercetin. It is concluded that quercetin reverses MDR of leukemic cells by multiple mechanisms and the reversing effect is positively related to drug concentration.

[Apoptosis-inducing effect of quercetin and kaempferol on human HL-60 cells and its mechanism].

The purpose of this study was to explore the anti-leukemia effect of quercetin and kaempferol and its mechanism. The HL-60 cells were used as the leukemia models. The inhibitory effects of quercetin and kaempferol on growth of HL-60 cells was assessed by MTT assay. The effect of quercetin and kaempferol on cell cycle in HL-60 cells was detected by flow cytometry. The cytotoxic effect of these 2 drugs was analysed by single cell electrophoresis assay. Western blot analysis was used to study the apoptotic mechanism of HL-60 cells. The results showed that the quercetin and kaempferol had a significant anti-leukemia effect in vitro. The proliferation of HL-60 cells was significantly inhibited in dose-and time-dependent manners after treating with quercetin (r = 0.77) and kaempferol (r = 0.76) respectively, and the cytotoxicity of quercetin was superior to that of kaempferol. The quercetin and kaempferol induced G(2)/M arrest and apoptosis of HL-60 cells. The quercetin and kaempferol could down-regulate the survivin expression. It is concluded that the quercetin and kaempferol have significant anti-leukemia effect in vitro. Furthermore the apoptosis-inducing effect of quercetin is stronger than that of kaempferol, both of which induce apoptosis of HL-60 cells through depressing cell growth, arresting cell cycle and inhibiting expression of survivin.

Recombinant human granulocyte colony-stimulating factor significantly decreases the expression of CXCR3 and CCR6 on T cells and preferentially induces T helper cells to a T helper 17 phenotype in peripheral blood harvests.

The aim of this study was to investigate the expression of chemokine receptors on T cells and functional changes of T helper (Th) cells in peripheral blood stem cell (PBSC) harvests after treating healthy donors with recombinant human granulocyte colony-stimulating factor (rhG-CSF). Using multiparameter flow cytometry, we analyzed the expression of CXCR3 and CCR6 on T cells and the production of interferon-gamma (IFN-gamma), interleukin-4 (IL-4), and IL-17 by CD4(+) Th cells in PBSC grafts of healthy donors after in vivo rhG-CSF application. Alterations in the relative expression levels of T cell receptor beta variable (TCRBV) family members were determined using real-time polymerase chain reaction (PCR). rhG-CSF mobilization significantly decreased the expression of CXCR3 and CCR6 on T cells. Treating donors with rhG-CSF resulted in decreased IFN-gamma production and dramatically increased IL-4 and IL-17 secretion by CD4(+) Th cells, leading to T cell polarization from the Th1 to the Th2 phenotype and a preferential increase in IL-17-producing CD4(+) Th cells. We did not observe any differences in the relative expression levels of TCRBV family members before and after in vivo rhG-CSF application. Our results suggest that the expression of CXCR3 and CCR6 on donor T cells was dramatically downregulated and an IL-17 phenotype of CD4(+) Th cells was preferentially induced in PBSC grafts after treating healthy donors with rhG-CSF. The observed effects of rhG-CSF on T cells may be independent of the relative expression levels of TCRBV family members.

[Correlation of chemokine CCL-2/MCP-1 level in the plasma with aGVHD and idiophathic pneumonia syndrome after allogeneic hematopoietic stem cell transplantation].

The aim of this study was to investigate the relationship between the plasma levels of chemokine CCL-2/MCP-1 and acute graft-versus-host disease (aGVHD) and/or idiopathic pneumonia syndrome (IPS) after allogeneic hematopoietic stem cell transplantation (allo-HSCT). ELISA assays were used to detect the plasma level of CCL-2/MCP-1 of 22 patients who received allo-HSCT, including 14 patients without or with grade I, 8 patients with grade II - IV aGVHD, respectively. 8 out of 22 patients were also diagnosed with IPS clinically. The dynamic changes of the plasma levels of CCL-2/MCP-1 chemokine and its correlation with aGVHD and/or IPS were analysized retrospectively. The results showed that the plasma levels of CCL-2/MCP-1 in the patients with moderate and serious aGVHD (grade II - IV) significantly increased, as compared with that prior to allo-HSCT (p < 0.05). The plasma levels of CCL-2/MCP-1 in the patients with aGVHD and/or IPS were higher significantly than those without any of these complications (p = 0.001). The retrospective analysis indicated that the plasma levels of CCL-2/MCP-1 in the patients with IPS significantly increased (p = 0.006). It is concluded that plasma level of CCL-2/MCP-1 correlates with aGVHD and/or IPS, and plays a role in the pathogenesis of these complications.

[Dendritic cells elicit cellular immune response by targeting to capture breast cancer cells].

OBJECTIVE: To investigate the specific anti-breast cancer immune response induced by dendritic cells (DC) loaded with trastuzumab and apoptotic Her-2+ breast cancer cells. METHODS: DCs were generated from healthy peripheral blood mononuclear cells (PBMCs) in the presence of recombinant cytokines GM-CSF, IL-4 and TNF-alpha. Mature DCs were harvested after 7 days' co-culture of PBMCs and trastuzumab-treated apoptotic SKBr3 cells. The morphologic characteristics and ultrastructure of the DC were observed under the inverted phase-contrast microscope and transmission electron microscope (TEM), respectively. Flow cytometry (FCM) was used to check the expression of several DC specific markers: CD14, CD1a, CD64, CD80, CD83, CD86, HLA-ABC and HLA-DR. DC-cytokine induced killer (DC-CIK) cells were prepared by co-culture of DCs and peripheral blood lymphocytes in the presence of anti-CD3 antibodies and human IL-2 at an appropriate concentration. The number of antigen-specific T cells was analyzed by human interferon gamma enzyme linked immunospot (ELISPOT) assay. MTT assay was employed to assess the lysis of breast cancer cell line induced by DC-CIK cells. RESULTS: 5 minutes after the adding of DCs to SKBr3 cells pretreated with trastuzumab, the apoptotic SKBr3 cells were found to be circled by DCs. 48 hours later, many membrane-wrapped organelles of the apoptotic target cells in the cytoplasm of DCs were found by TEM. The majority of the organelles were degraded. Fewer organelles from the apoptotic cells were found in DCs without Herceptin. More than 60% in every group of DCs expressed a high-affinity receptor for IgG (FcgammaRI or CD64). CD14 expression on the mature DCs were comparatively lower, and HLA-DR and HLA-ABC expressions were higher in the trastuzumab group. The expression of CD1a, CD80, CD83 and CD86 in trastuzumab group were higher than those in immature DCs group (P < 0.05). ELISPOT assay suggests that the spot number of antigen-specific T cells were higher in trastuzumab group than that in the antigen unloaded DCs group (P < 0.05). The lysis of SKBr3 cells induced by the SKBr3 antigen loaded DC-CIK cells were 1.7 times higher than that of CIK. CONCLUSION: The lysis of SKBr3 cells induced by DC-CIK was increased after that DCs were combined with trastuzumab to capture antigen from SKBr3 cells. These findings support further investigation into the use of combination immunotherapy of the humanized monoclonal antibody, DC vaccines and immunological effector cells.

[rhIL-11 accelerates the engraftment of platelets after unrelated cord blood transplantation].

OBJECTIVE: To observe whether rhIL-11 could accelerate the engraftment of platelets after unrelated cord blood transplantation (CBT). METHODS: Nine patients (3 children and 6 adults) were enrolled in this study. The degree of HLA disparity was 0-2 loci. Cord blood was given two units for adults and one unit for children. Conditioning regimens were CY/TBI in 1 and BU/CY in 8 cases, both with antithymocyte globulin. Graft-versus-host disease (GVHD) prophylaxis consisted of cyclosporine and short-term methotrexate. On day +1, rhIL-11 was used at 50 microg x kg(-1) x d(-1) and G-CSF at 5 microg x kg(-1) x d(-1) to accelerate hematopoiesis recovery. RESULTS: The median age of the patients was 22.3 years and the median weight 52.3 kg. Among the 9 patients, 8 (88.9%) experienced engraftment. The median time to neutrophil > 0.5 x 10(9)/L was 21.3 (14-37) days and to platelet > 20 x 10(9)/L was 25 (18-36) days. 42.9% of the patients developed grade I aGVHD and 33.3% developed localized chronic GVHD. Six patients were alive and disease-free at a median follow-up of 7 months. Infection was the primary cause of death. The expected 1-year survival was 77.8%, 2-year survival was 52.2%. Five of 8 patients (62.5%) who received IL-11 presented leakage syndrome. On prophylaxis with drugs containing Arnebia root extract, all patients could tolerate the treatment. CONCLUSION: rhIL-11 maybe helpful for accelerating the platelet recovery and reducing aGVHD severity in unrelated CBT. The major side effect is leakage syndrome. It is well tolerated on prophylaxis with drugs containing Arnebia root.

[Human/mouse chimeric anti-CD20 monoclonal antibody enhances antigen presentation in dendritic cells and induces anti-lymphoma CTL effects].

In order to investigate the cellular immunoresponses mediated by chimeric anti-CD20 monoclonal antibody (anti-CD20 McAb) through dendritic cells (DCs), mononuclear cells were isolated from human peripheral blood (PBMNC) and DCs from PBMNCs in vitro were generated with normal methods. Human CD20 positive lymphoma cell line-Raji cells were treated with different methods including treatment with anti-CD20 McAb (group R), treatment with heat-induced apoptosis (group A) and treatment with anti-CD20 McAb+heat-induced apoptosis (group R+A), then Raji cells treated with above-mentioned methods as tumor antigen were loaded on DCs. The phagocytosis of DCs to tumor antigen was observed by transmission electron microscope (TEM), the auto-mixed lymphocyte reaction was performed with antigen-primed DCs, the release of INF-gammafrom effector cells was detected by ELISPOT, the killing of effector cells on Raji cells was assayed by MTT. The results showed that under TEM, no pronounced phagocytosis of DCs was seen in group R, while the phagocytosis of apoptotic bodies could be easily seen in group A and the more cell fraqments were observed in group R+A. The FCM indicated that the expressions of CD80, CD86 and HLA-DR on DCs in 3 experimental groups were higher than those in group control (p<0.05), while expression positive rate in group R+A was higher than those in group R and A (p<0.05). The detection of lymphocyte surface antigen revealed that proportions of CD8+ cells in all experimental groups were higher than those in group control (p<0.05), count of CD56+ cells in group R and R+A increased, as compared with group A and control, difference was significant (p<0.05). ELISPOT assay indicated that amount of cells releasing IFN-gamma in all experimental groups was higher than that in group control, and also number of spots in group R+A significantly higher than that in other groups at effector-targetor ratio=1:10 (p<0.05). The results of killing assay demonstrated that killing rate on Raji cells in all experimental groups increased as compared with group control (p<0.05), while killing rate in group R+A was higher than that in group R and A. It is concluded that anti-CD20 McAb can mediate DC to induce cellular immunoresponse against lymphoma, that is, to stimulate and amplify specific CTLs and NK cells. Anti-CD20 McAb combined with DCs primed by heat-stressed tumor cells as antigen can further enhance cellular immunoresponse against lymphoma.

[In vitro study about the inhibitory effect of CDAII in combination with sodium butyrate on breast cancer cells].

OBJECTIVE: To investigate if the combined use of CDAII and sodium butyrate can induce demethylation and re-expression of retinoic acid receptor beta2 (RARbeta2) gene in cultured human breast cancer cells MCF7. To explore if the two drugs can inhibit cell growth and induce cell apoptosis synergetically. METHODS: MCF7 cell line was treated with CDAII, sodium butyrate, combination of the two drugs respectively. Methylation was assessed by methylation-specific polymerase chain reaction (MSP) for RARbeta2 gene. Gene expression was evaluated by reverse transcription polymerase chain reaction (RT-PCR). Apoptosis was detected by terminal deoxynucleotidyl transferase mediated dUTP-biotin nick end labeling(TUNEL) and Hoechst33342/propidiumiodide (PI) staining. Cell growth inhibition was measured by MTT assay. RESULTS: Neither CDAII nor sodium butyrate induced demethylation and re-expression of RARbeta2 gene, Combination of the two drugs partially demethylated gene promoter accompanied by re-expression of RARbeta2. The apoptotic cells in the double-drug group were obvious following Hoechst33342/PI staining. The percentage of apoptotic cells in the double-drug group was significantly higher than that of the two single-drug group (39.5% vs 5.2%, 8.1%) (P<0.05). MTT assay showed that compared with single drug,combination of the two drugs inhibited cell growth more significantly, and the two drugs showed interaction (F=15, P<0.05). CONCLUSION: We showed that CDAII, in combination with histone deacetylase inhibitor sodium butyrate synergetically inhibited the proliferation of MCF7 breast cancer cell line and induced apoptosis, in which demethylation and re-expression of RARbeta2 gene induced by combination of the two drugs may be involved.

[Immunological effector cells enhance apoptosis induced by adriamycin in a multi-drug resistant human breast cancer cell line].

OBJECTIVE: To investigate the effects of immunologic effector cells to enhance apoptosis induced by adriamycin (ADR) in multi-drug resistant human breast cancer cell line MCF7/ADR. METHODS: The immunologic effector cells were induced and expanded by IFN-gamma, McAb CD3, IL-1 and IL-2. The expression of P-glycoprotein (P-gp) and its relation to apoptosis in target cells were detected by TUNEL technique and immunohistochemical staining. Flow cytometry (FCM) was carried out to determine the expression level of human breast cancer related P185 antigen and the positive rate of Annexin V-FITC/PI expression. The subcellular distribution of ADR and Annexin V expression in the target cells were detected by fluorescence microscopy. RESULTS: The immunologic effector cells down-regulated the expression of P185 and P-gp in MCF7/ADR cells. The accumulation and subcellular distribution of ADR in MCF7/ADR cells were increased after co-culture with the immunologic effector cells. After treatment with the immunologic effector cells in combination with ADR, apoptosis rate of the target cells was 10 times higher than that induced by ADR alone, and 13 times higher than that induced by the immunologic effector cells alone. CONCLUSION: Immunologic effector cells can simultaneously down-regulate the expression of P185 and P-gp in MCF7/ADR cell line, and increase the apoptosis rate of MCF7/ADR cells in combination with ADR.

[Effect of the new human transcription factor hBKLF on the proliferation, differentiation of K562 cell line and hemoglobin synthesis].

The human basic Krüppel-like factor (hBKLF) is a newly cloned human transcription factor from the cDNA library of fetal liver. It belongs to the Krüppel-like transcription factor family. Previous expression study showed that it is a hematopoietic related factor. This study was aimed to investigate the effect of hBKLF on cell proliferation, differentiation and hemoglobin synthesis by using K562 cell line as model. The sense and antisense expression plasmids of hBKLF were constructed, and transfected into K562 cells by lipofectamine. After G418 selection for 4 weeks, the cell line with stable expression of the gene was obtained. Then the hBKLF expression level, proliferation ability, colony formation and hemoglobin production were detected by RT-PCR and Western blot, MTT method, methyl cellulose semisolid culture method and benzidine test respectively. The morphologic change of cell was observed with inverted microscope. The results showed that the sense plasmid could increase hBKLF level and antisense plasmid could decrease hBKLF expression. When hBKLF level was down-regulated, K562 cells could proliferate more quickly and synthesize more hemoglobin. But there were no differences in colony formation ability and no apparent morphologic change. It is concluded that hBKLF can inhibit hematopoietic cell proliferation and hemoglobin synthesis. It is suggested that hBKLF plays an important role in the proliferation and differentiation of hematopoietic cells.

[Influence of HSP70 on combined method of hyperthermia and immunologic effector cells to treat cancer].

OBJECTIVE: To investigate hyperthermia enhanced expression of heat shock protein70 (HSP70) in breast cancer drug sensitive cell line MCF7 and multi-drug resistant (MDR) cell line MCF7/ADR, so as to increase cytotoxic activity of immunologic effector cells against the target cells, and to provide an experimental basis for cell immunotherapy based on hyperthermia. METHODS: The immunological effector cells were induced and expanded by cytokines. Breast cancer cell lines MCF7 and MCF7/ADR were treated at 42 degrees C for an hour. Then after being incubated for additional 4 hours, 24 hours and 48 hours, the cells were digested. Flow cytometry (FCM) was used to detect the expression of HSP70 on the target cells. MTT assay was employed to evaluate cell proliferation and the cytotoxic activity of immunologic effector cells against target cells. RESULTS: The expressions of HSP70 in both the target cells had significant difference. The expression of HSP70 in MCF7/ADR cells was higher than in MCF7 cells before hyperthermia. After hyperthermia the expression of HSP70 increased by 6 folds in MCF7/ADR cells, and 22 folds in MCF7 cells and was higher than in MCF7/ADR cells at hour 4. The proliferation inhibition fraction of hyperthermia against MCF7 was significantly lower than that of MCF7/ADR. The cytotoxic activity of immunologic effector cells against MCF7 cells was lower than against MCF7/ADR cells before hyperthermia. After hyperthermia the cytotoxic activity of immunologic effector cells against MCF7 cells rose by 86.23%, and was higher than against MCF7/ADR cells (rose by 30.32%). CONCLUSION: The expression of HSP70 in breast cancer drug sensitive cell line MCF7 and MDR cell line MCF7/ADR were enhanced significantly by hyperthermia. Cytotoxic activity of immunologic effector cells against both the target cells were increased by hyperthermia. The differential expressions of HSP70 in breast cancer drug sensitive cell line MCF7 and MDR cell line MCF7/ADR affect the cytotoxic activity of immunologic effector cells.

[Construction of recombinant vector expressing ALAS2 gene in X-linked sideroblastic anemia].

X-linked sideroblastic anemia (XLSA) is caused by mutations of erythroid-specific 5-aminolevulinate synthetase (ALAS2) gene. In this study a eukaryotic expression vector of ALAS2 was constructed and transfected into eukaryotic cells to observe the expression of ALAS2 gene. The full length cDNA of ALAS2 gene was inserted into plasmid pDs-red2-N1, named pDs-red2-N1/ALAS2. Then, the vector was transfected into K562 cells via electroporation. At 48 hours after transfection, total RNA from K562 cells was extracted, expressions of ALAS2 gene and protein with red fluorescence in the K562 cells were detected by RT-PCR and flow cytometry, respectively. The vector was also transfected into COS 7 cells via liposome. Both mRNA and protein expression in COS7 cells were detected by RT-PCR and fluorescence microscopy. The result showed that after the pDs-red2-N1/ALAS2 eukaryotic expression vector was digested by KpnI and BamHI, two fragments of 4 700 bp and 1 764 bp were displayed by electrophoresis on agarose gel. Sequence method confirmed that the sequence was correct. RT-PCR amplified the total RNA extracted from the transfected K562 and COS7 cells, and could find mRNA of ALAS2 gene that can't be found in K562 and COS7 cells usually. The expressions of both fluorescein and ALAS2 were significantly increased. The percentage of positive cells reached about 19.2% and 10.7%, respectively. ALAS2 expression lasted for 10 days in COS7 cells and the peak was at the third day. It is concluded that the eukaryotic expression vector of ALAS2 gene is successfully constructed; K562 and COS7 cells transfected with the vector via electroporation and liposome can express ALAS2 protein. So, the vector has the potential in gene replacement and can be used for patients with XLSA in future.