Biomedical subjects

Dao-xin Ma

Publications and source records attributed to Dao-xin Ma.

14 recordsLinked to original sources

PubMed2006

[Experimental study on immunotherapy with dendritic cell in leukemic mice model].

OBJECTIVE: To explore the feasibility and efficiency of immunotherapy with dendritic cell (DC) in leukemic mice model after allogeneic bone marrow transplantation (allo-BMT). METHODS: Mature DC were expanded from mice bone marrow mononuclear cells (MNC) by adding mouse granulocyte-macrophage colony stimulating factor (mGM-CSF) and interleukin-4 (mIL-4). Three days later they were pulsed with frozen thawing L7212 leukemia-related antigen. Mice bearing leukemia received allo-BMT at d 0, and then were divided into control group (A), T cells group (B) and DC + T cells group (C) to receive respective immune therapy at d 14. The survival rate, survival time, occurrence of graft-versus-host disease (GVHD), cytotoxicity of spleen cells and serum cytokine level were observed. The survivors in each group were rechallenged with L7212 cells to observe the immune response to the leukemia. RESULTS: Mature DC were successfully induced from bone marrow MNC. In groups B and C, the relapse rates were 30% and 0%, while the long term survival rates after BMT was 30% and 70% respectively. Both of the differences were statistically significant (P < 0.05). However, the incidence of GVHD in these two groups were similar. The mean survival times were (32.95 +/- 13.29) days and (41.15 +/- 13.88) days, respectively (P < 0.01). MTT assay indicated that spleen cells from group C had specific killing activity to L7212 cells. Enzyme-labeled immunosorbent assay (ELISA) showed that the serum IL-2 level in group C was (419.75 +/- 26.66) pg/ml, being significantly higher than that in the other two groups (P < 0.01). When the survivors were rechallenged with L7212 cells, there was difference between the survival rates of groups C and B (85.7% vs 33.3%, P < 0.05). CONCLUSION: Immunotherapy with leukemia related antigen-pulsed DC in combination with donor lymphocyte infusions is an effective approach to reinforce GVL effect and decrease relapse after allo-BMT.

Animals↗

PubMed2006

[The immunoreactivity of IgG and its fragments from ITP patients and their effects on platelet aggregation function].

OBJECTIVE: To prepare ITP plasma IgG and its F(ab')2 fragments and investigate their immunoreactivity to platelet GPIIb/IIIa and/or GPIb/IX and their effects on platelet aggregation function. METHODS: The ITP patients having inhibitory autoantibody to the platelet aggregation were selected by modified MAIPA and platelet aggregation test with turbidimetry. Plasma IgG and its F(ab')2 fragments were prepared by streptococcal protein A affinity column and pepsin digestion. The immunoreactivity and the effects on platelet aggregation function of the whole antibody and its fragments were detected by modified MAIPA and platelet aggregation test, respectively. RESULTS: (1) Anti-platelet GPIIb/IIIa and/or GPIb/IX autoantibodies were detected in 34 of 68 (53.6%) ITP patients' plasmas and that from 5 patients significantly inhibited the platelet aggregation induced by ADP or ristocetin. (2) By using protein A column combined with protease digestion, pure IgG and its F(ab')2 fragments were successfully obtained. (3) The purified IgG and its F(ab')2 fragments retained the ability to bind to their respective glycoproteins and inhibited the platelet aggregation function, whereas the IgG depleted plasma lost the ability of binding to the platelet GPs. CONCLUSIONS: F(ab')2 fragment of the IgG antibody is a functional fragment, which not only has the binding ability to the platelet GPs but also inhibits the platelet aggregation function in a dose-dependent manner.

Adolescent↗

PubMed2005

[Mechanism of cell-mediated lysis of autologous platelets in chronic idiopathic thrombocytopenic purpura].

OBJECTIVE: To investigate the contribution and mechanism of cell-mediated cytotoxity to the pathogenesis of idiopathic thrombocytopenic purpura (ITP). METHODS: (1) Mononuclear cells and platelets were prepared from the peripheral blood of 14 ITP patients and 10 healthy controls. Separately, CD 8(+) T cells and NK cells (CD 3(-)CD 16(+)CD 56(+)) were positively selected with magnetic microbeads. (2) As the target cells, the autologous platelets were cultured with CD 8(+) T cells or NK cells for 4 hours and then stained with annexin V. Ratio of platelets expressing annexin V was determined by flow cytometry. (3) The fraction of CD 8(+) T cells expressing FasL, TNFalpha and TRAIL were determined by flow cytometry. (4) The expression levels of perforin and granzyme B mRNA in CD 8(+) T cells were measured by semiquantitative reverse transcriptase polymerase chain reaction (RT-PCR) procedure. RESULTS: (1) When the platelets were incubated alone the annexin V positive platelet ratio of the ITP patients was 3.1% +/- 0.9%, not significantly different from that of the controls (3.2% +/- 1.1%, P > 0.05); (2) When the platelets were co-incubated with CD 8(+) cells the annexin V positive platelet ratio of the ITP group (7.6% +/- 2.8%), significantly higher than that of the control group (3.6% +/- 0.9%, P < 0.05); (3) When NK cells were used as effector cells, the annexin V positive platelet ratio of the ITP group was 3.5% +/- 1.1%), not significantly different from that of the control group (3.6% +/- 1.0%, P > 0.05); (4) The expression rates of FasL and TNFalpha on CD 8(+) T cells of the ITP group were 17.5% +/- 4.4% and 11.9% +/- 4.9% respectively, both significantly higher than those of the control group (8.9% +/- 1.5% and 6.4% +/- 2.1% respectively, both P < 0.05), while the expression rate of TRAIL of the ITP group was 16.1% +/- 3.8%, not significantly different from that of the control group (14.0% +/- 3.2%, P > 0.05); (5) The mRNA levels of granzyme B and perforin in the CD 8(+) T cells of the ITP group were 2.20% +/- 0.15% and 2.47% +/- 0.39% respectively, both significantly higher than those of the control group (1.63% +/- 0.22% and 1.80% +/- 0.31% respectively, both P < 0.05). CONCLUSION: Cytotoxic T lymphocyte (CTL) are activated in ITP and might be involved in the pathogenesis of ITP, while the NK cells have no direct cytotoxic effect on platelets. Apoptosis and perforin/granzyme-mediated cytotoxicity are two important pathways through which CTL destruct auto-platelets.

Adolescent↗

PubMed2005

[VP22 enhances the immunological activity of human cytomegalovirus pp65 DNA vaccine: experimental study with mice].

OBJECTIVE: To construct the human cytomegalovirus (HCMV) pp65 DNA vaccine vector and VP22 and pp65 coexpressing vector. To evaluate and compare immunological effects in mice. METHODS: Twenty-one BALB/C mice were divided into 3 equal groups: pcDNA3.pp65 group undergoing injection of pcDNA3.pp65 as DNA vaccine, pVP22.pp65 group undergoing injection of pVP22.pp65, and control group undergoing injection of normal saline. HCMV pp65 expression vector pcDNA3.pp65, VP22 and pp65 coexpressing vector pVP22.pp65 were constructed by molecular biology methods. The vectors were immunized into BALB/C mice as DNA vaccines. The T cell proliferation activity and IL-2 biological activity were determined using MTT method. NK activity was detected using LDH release test. The serum IgM and IgG levels of HCMV, the concentrations of IL-2 and IL-4 in serum and supernatant of spleen cells were detected using ELISA method. RESULTS: The HCMV DNA vaccine expression vectors were successfully constructed. Some indexes of the two vaccine groups (pcDNA3.pp65 and pVP22.pp65), that is, T cell proliferation activity (5.11 and 5.55 for SI at 8th week respectively), NK activity (8.74% and 12.08% at 12th week respectively), IgM level (1.20 and 1.58 for A value at 6th week respectively) and IgG level (1.09 and 1.78 for A value at 6th week respectively) were higher than those of negative control, and pVP22.pp65 group was higher than pcDNA3.pp65 group (P < 0.05). The concentrations of IL-2 and IL-4 and the IL-2 biological activity were very low in sera of three groups which showed no significant difference between them (P > 0.05), but higher in the spleen supernatant and the pVP22.pp65 group was highest (411.11 pg/ml, 76.10 pg/ml for the concentrations of IL-2 and IL-4 and 0.22 for IL-2 biological activity). CONCLUSION: The HCMV pp65 could induce certain immunological activity, and VP22 could significantly enhance pp65 in vivo immunological activity.

Animals↗

PubMed2005

[Construction and clinical applications of a humanized phage library of platelet GPIIb/IIIa single chain Fv antibody].

OBJECTIVE: To screen out the anti-platelet GPIIb/IIIa autoantibody which can inhibit with aggregation function of platelet and construct a humanized anti-platelet GPIIb/IIIa single chain Fv library by phage surface display technology. METHODS: Idiopathic thrombocytopenic purpura (ITP) patients whose plasma contains anti-platelet GPIIb/IIIa autoantibodies were screened out. The antibodies can inhibit the aggregation function of platelet by using MAIPA assay and platelet aggregation test. The heavy chain and light chain variable region genes of human immunoglobulin were amplified by RT-PCR from peripheral blood lymphocytes mRNA of the patients screened out and randomly combined through a DNA linker encoding the peptide (Gly(4)Ser)(3) to construct single chain Fv gene. ScFv gene was digested with SfiI/NotI restricted digest enzyme to ligate the pHEN2 cloning vector, then were electrically transformed to E.coli TG1. The TG1 containing ScFv-pHEN2 was rescued by helper phage M13K07 to produce ScFv phage antibody. RESULTS: Of 95 chronic ITP patients, 41 (43.2%) were found positive for anti-platelet GPIIb/IIIa autoantibody, 5 (5.3%) were markedly positive. 2 (2.1%) patients plasma significantly inhibited the aggregation function of platelet. The lengths of VH and VL were about 380 to 400 bp. They were successfully linked by DNA linker to form ScFv fragment of about 780 bp. After cloning ScFv to phagemid pHEN2 and transforming ScFv-pHEN2 to TG1, 2.1 x 10(7) clones formed. After M13K07 rescue, 1.62 x 10(10) cfu/ml ScFv phage antibodies were produced. CONCLUSION: Few anti-platelet GPIIb/IIIa antibodies can inhibit the aggregation function of platelet. A phage antibody library has been constructed by phage surface display technology. Humanized anti-platelet GPIIb/IIIa ScFv phage antibody can be screened from this library.

Adolescent↗

PubMed2005

[Procaspase-3 enhances in vitro effect of cytosine deaminase-thymidine kinase fusion disuicide gene therapy system on human ovarian carcinoma].

OBJECTIVE: To investigate whether procaspase-3 could enhance the in vitro effect of cytosine deaminase-thymidine kinase/5-fluorocytosine + ganciclovir (CD-TK/5-FC + GCV) system in human ovarian cancer cells. METHODS: Eukaryotic expression vectors containing procaspase-3 gene (pcDNA3-casp3) and CD-TK fusion disuicide genes regulated by human telomerase reverse transcriptase (hTERT) promoter (pBTdel-279-CD-TK) were constructed. Western blot was used to detect the expression of procaspase-3 protein in 3AO cells with transfection of pcDNA3-casp3 (3AO-pcDNA3-casp3) or pcDNA3 (3AO-pcDNA3). RT-PCR was used to detect the expression of CD and TK genes in 3AO-pcDNA3-casp3 or 3AO-pcDNA3 cells after transfection with pBTdel-279-CD-TK or pBTdel-279. Following the treatment with 5-FC + GCV, the cell survival rate and cell cycle distribution were detected by methyl thiazolyl tetrazolium (MTT) assay and flow cytometry (FCM). Fluorogenic substrate assay and western blot were used to detect caspase-3 activity in these cells. RESULTS: Procaspase-3 protein was expressed in 3AO-pcDNA3-casp3 cells, while not in 3AO-pcDNA3. The expressions of CD and TK genes were observed in both 3AO-pcDNA3-casp3 and 3AO-pcDNA3 after transfection with pBTdel-279-CD-TK. After treatment with 5-FC + GCV, the survival rate of 3AO-pcDNA3-casp3 + pBTdel-279-CD-TK was significantly lower than that of 3AO-pcDNA3 + pBTdel-279-CD-TK cells. After treatment with 5-FC (2 mmol/L) + GCV (10 microg/ml), there was a higher apoptotic ratio (37.98%) and S-phase block (49.67%) in 3AO-pcDNA3-casp3 + pBTdel-279-CD-TK than in 3AO-pcDNA3 + pBTdel-279-CD-TK cells (21.34% and 35.76%, respectively) (P < 0.05). Following the action of 5-FC (1 mmol/L) + GCV (1 microg/ml) for 48 h, the relative activity of caspase-3 in 3AO-pcDNA3-casp3 + pBTdel-279-CD-TK cells was 189.7, significantly higher than 44.9 in 3AO-pcDNA3 + pBTdel-279-CD-TK cells (P < 0.05). CONCLUSION: Co-expression of procaspase-3 may lead to a significant enhancement of the efficacy of CD-TK fusion gene therapy.

Carcinoma↗

PubMed2005

[Inhibition of multidrug resistance related P-gp expression in human neuroblastoma by antisense peptide nucleic acid].

OBJECTIVE: To investigate the efficiency of a peptide nucleic acid (PNA) delivery system by using liposome via PNA-DNA hybrids and to test the inhibitive action of antisense PNA on expression of multidrug resistance (MDR) related P-glycoprotein (P-gp) in human neuroblastoma cell line SK-N-SH. METHODS: Two antisense PNAs were designed targeting at MDR-1 mRNA and then combined with partially complement DNAs respectively. The hybrids were delivered into cells using cationic liposome. The transfection efficiency, expression of P-gp and MDR-1 mRNA, intracellular adarimycin (ADM) were measured by flow cytometry, reverse transcription-polymerase chain reaction (RT-PCR), and high performance liquid chromatography (HPLC). RESULTS: Transfection of PNA increased the cell average fluorescence intensity significantly and the extent of increase was dependent on the concentration of PNA. After being transfected by both PNAs, P-gp expression of SK-N-SH cells decreased significantly and the intracellular ADM level was increased by about 3 times. The level of MDR-1 mRNA expression slightly decreased after transfection, but no statistical significance was observed. CONCLUSIONS: PNA can be delivered into tumor cells in form of PNA-DNA hybrids by cationic liposome. Properly designed antisense PNA can inhibit MDR related P-gp expression of SK-N-SH cells efficiently and specifically.

ATP Binding Cassette Transporter, Subfamily B, Mem↗

PubMed2004

[Application of pseudotyped lentivirus-mediated double suicide genes to allogeneic bone marrow transplantation in mice].

OBJECTIVE: To explore the feasibility and efficiency of cytosine deaminase (CD)/thymidine kinase (TK) gene-modified donor T cells used in allogeneic bone marrow transplantation (allo-BMT) as an approach to mitigate GVHD without compromising engraftment. METHODS: The pseudotyped lentivirus vectors containing CD and TK double suicide genes were transfected with lipofectine to donor T cells. Lethally irradiated 615 leukemia mice were transplanted with BALB/c bone marrow plus CD(+)TK(+)T cells. GVHD prophylaxis was by administration of ganciclovir (GCV) and 5-Fluoride cytosine (5-FC). RESULTS: The pseudotyped lentivirus-mediated gene transfer system could efficiently transfer CD and TK double suicide genes into donor T cells. Administration of GCV and 5-FC to the mice could markedly potentiate the CFU-S and CFU-GM yields and raise the number of peripheral white blood cells. 1 x 10(7) CD(+)TK(+) allogeneic T cells caused GVHD of a similar magnitude and time course to that of fresh, naive T cells after allo-BMT. Administration of GCV and 5-FC in mice received CD(+)TK(+)T cells reduced the severity of GVHD and resulted in significantly longer survival as compared with non-administration mice, and the effect was stronger than that of administration of GCV or 5-FC alone. CONCLUSION: Administration of CD + TK gene-modified donor T cells to recipient in allo-BMT might be an approach to mitigate GVHD without compromising alloengraftment.

Animals↗

PubMed2004

[Study of the clonal characteristics of autoantibodies in chronic idiopathic thrombocytopenic purpura].

OBJECTIVE: To define the clonality characteristics of autoantibodies in chronic idiopathic thrombocytopenic purpura (ITP). METHODS: The heavy-chain and light-chain phenotype composition of the glycoprotein (GP)-specific IgG antibodies were analysed with a modified monoclonal antibody specific immobilization of platelet antigens (MAIPA) technique. The immunoglobulin heavy-chain gene rearrangement was analysed by PCR amplification. RESULTS: 16 out of the 43 patient sera reacted with least one of the following five GPs, namely GPIIb/IIIa, GPIb, GPIa, GPIV and GPV. Eight of 11 (73%) GP-specific antibodies displayed a restricted heavy-chain phenotypes. 80% (16/20) of the GP-specific antibodies showed a restricted kappa or lambda light-chain phenotype. Moreover, in 6 patients the GP-specific antibodies were found to be both light-chain and heavy-chain restricte. Using PCR amplification of immunoglobulin heavy-chain genes, 3 patients displayed heavy-chain genes rearrangement. CONCLUSION: The GP-specific autoantibodies are derived from a restricted number of B-cell clones in proportion of ITP patients.

Adolescent↗

PubMed2004

[Hepatocellular carcinoma associated antigen HCA520, a novel Ca2+-binding protein].

AIM: To analyze the binding activity of the hepatocellular carcinoma associated antigen HCA520 to Ca2+. METHODS: The HCA520 gene was gained by PCR. Then, it was cloned into the prokaryotic expression vector pGEX-4T-3. The GST-HCA520 fusion gene was induced to express in E. coli and the expressed product was purified via GST-agarose affinity resin. The fusion protein was confirmed by Western blot analysis. The Ca2+ binding capability of the fusion protein was analyzed by dot blot. RESULTS: The GST-HCA520 fusion gene was constructed and the protein was successfully expressed and purified, which was identified by DNA sequencing and Western blot respectively. The fusion protein could bind to Ca2+ depend on dosages. CONCLUSION: HCA520, a novel hepatocellular carcinoma associated antigen, is a novel Ca2+ binding protein.

Calcium↗

PubMed2004

[In vitro treatment of ovarian cancer cells with cytosine deaminase-thymidine kinase fusion disuicide gene therapy system under the control of human telomerase reverse transcriptase gene promoter].

OBJECTIVE: To investigate the in vitro effects of cytosine deaminase-thymidine kinase/5-fluorocytosine + ganciclovir (CD-TK/5-FC + GCV) on ovarian cancer cells and normal cells using a human telomerase reverse transcriptase (hTERT) promoter-driven vector system. METHODS: hTERT promoter activity was determined by luciferase assay after the plasmids of pBTdel-279 containing hTERT core promoter were transfected into ovarian carcinoma-derived cell line 3AO, human normal ovarian epithelial cell (NOEC) and human embryonic lung fibroblast (HELF). hTERT mRNA expression levels of these cells were determined by reverse transcription polymerase chain reaction (RT-PCR). Eukaryotic expression vectors containing CD-TK fusion disuicide genes under the control of hTERT promoter (pBTdel-279-CD-TK) and cytomegalovirus (CMV) promoter (pcDNA3-CD-TK), as well as vectors containing TK gene under hTERT promoter control (pBTdel-279-TK), were constructed and transfected into 3AO, NOEC and HELF cells by cationic liposome. Following the transfection with CD and TK, 5-FC and GCV of different doses were added and methyl thiazolyl tetrazolium (MTT) and flow cytometry methods were applied to investigate the antitumor effects of pBTdel-279-CD-TK/5-FC + GCV and pcDNA3-CD-TK/5-FC + GCV systems. pBTdel-279-TK/GCV was considered as a control. RT-PCR was used to detect CD and TK genes in ovarian cancer cells and normal cells before and after the transfection of pBTdel-279-CD-TK or pcDNA3-CD-TK. Scanning electron microscopy (SEM) was used to examine the morphology of 3AO after the action of pBTdel-279-CD-TK/5-FC + GCV. RESULTS: hTERT promoter activity was 24.1% and hTERT mRNA expression was positive in ovarian cancer cell 3AO, whereas in NOEC or HELF the activity was 0.3% or 0.7% and hTERT mRNA expression was negative. Expression vectors of pBTdel-279-CD-TK, pcDNA3-CD-TK and pBTdel-279-TK were successfully constructed. Compared with the effects of pBTdel-279-TK/GCV, the pBTdel-279-CD-TK/5-FC + GCV system was more efficient on hTERT positive ovarian cancer cells, but had no effects on hTERT-negative NOEC and HELF cells. The killing rate was 74.5% when 5-FC was at 2 mmol/L and GCV at 10 mg/L. The hTERT promoter system was nearly as efficient as the CMV promoter system in inducing cancer cell death (P > 0.05). CD and TK genes were expressed in all the three kinds of cells after pcDNA3-CD-TK transfection, while positive only in ovarian cancer cells after pBTdel-279-CD-TK transfection. Apoptosis was the major death form of 3AO following the effects of pBTdel-279-CD-TK/5-FC + GCV. CONCLUSION: The telomerase-specific expression of CD and TK genes under the hTERT promoter control is a novel targeting approach for gene therapy of ovarian cancer.

Cystadenocarcinoma, Serous↗

PubMed2003

[Tegument viral protein 22 enhanced cell-killing effect of the herpes simplex virus thymidine kinase/ganciclovir system on ovarian cancer in vivo].

OBJECTIVE: To explore the enhanced cell-killing effect in vivo of herpes simplex virus thymidine kinase/ganciclovir (HSV-TK/GCV) gene therapeutic system using tegument viral protein (VP22) intercellular trafficking. METHODS: Human ovarian epithelial cancer cell line 3AO was infected by lentivirus containing HSV-TK and HSV-VP22-TK respectively. Tumors were induced in nude mice by subcutaneous injection of the mixture of 90% 3AO cells and 10% 3AO cells carried with HSV-TK (3AO/TK) or HSV-VP22-TK (3AO/VP22-TK). Nude mice injected with 3AO cells were used as blank control. When the volume of tumor was 150 mm(3), GCV was administered at 10 mg/kg or 50 mg/kg intraperitoneally. RESULTS: There were significant differences, in the tumor volume and weight between 3AO/TK group and 3AO/VP22-TK group after administration of 10 mg/kg GCV (P < 0.01), and the later was more efficient than the former. But there was no significant difference after administration of 50 mg/kg GCV (P > 0.05). The tumor inhibition rates in 3AO/VP22 group and 3AO/VP22-TK group were 37.7% and 91.5% respectively after administration of 10 mg/kg GCV (P < 0.01), and were 81.8% and 96.7% respectively after administration of 50 mg/kg GCV (P > 0.05). CONCLUSION: These results clearly indicate that VP22 enhances the efficiency of the suicide gene transfer, thereby increases the cell-killing effect on tumor in vivo.

Animals↗

PubMed2003

[Study of the therapeutic effects of costimulatory molecules B7-1 and interleukin 12 modified tumor cells vaccines on ovarian epithelial carcinoma through induction of anti-cancer immunity of the body].

OBJECTIVE: To study the biological characters of tumor cell vaccines modified by interleukin 12 (IL-12) and co-stimulatory molecule B(7 - 1) and their combination therapeutic effect on rat ovarian cancer animal model. METHODS: Retroviral vector pLmB(7 - 1)SN, which expressed murine B(7 - 1) was constructed. An epithelial ovarian cancer cell line NuTu-19 was infected with pLmIL-12SN and/or pLmB(7 - 1)SN by lipofectin-mediated gene transfer system. Cell lines that could highly express either or both of these cytokines were named NuTu-19/IL-12, NuTu-19/B(7 - 1) or NuTu-19/IL-12-B(7 - 1), according to the results of enzyme-linked immunosorbent assay (ELISA) and flow cytometry (FCM). NuTu-19/Neo, the cell line that was transfected by vector pLXSN was used as a control. Various types of cytokine-modified tumor cells were injected subcutaneously into syngeneic rats Fischer 344 and their tumorigenecities were recorded. After being immunized twice by various types of mitomycin C treated gene modified tumor cells, the survival time of the intraperitoneal disseminating ovarian cancer animal model was observed, and the anti-tumor mechanisms of different gene modified tumor cell lines were discussed. RESULTS: The reconstruction of pLmB(7 - 1)SN was successful. Stable IL-12 and B(7 - 1) expression in cell lines NuTu-19/B(7 - 1), NuTu-19/IL-12 and NuTu-19/IL-12-B(7 - 1) were confirmed by ELISA and FCM. Tumorigenecities of various gene modified tumor cells decreased in syngeneic rats. The splenic lymphocytes proliferation indices (PI) in B(7 - 1) group (NuTu-19/B(7 - 1) immunized group) and IL-12 group (NuTu-19/IL-12 immunized group) were 2.4 and 4.6 (the letter P < 0.05 compared with that in control group), while PI in B(7 - 1) and IL-12 combination group (NuTu-19/IL-12-B(7 - 1) immunized group) increase to 10.2, being of significantly difference compared with those in control or B(7 - 1) or IL - 12 group (P < 0.01). More significant cytotoxic effects of cytotoxic lymphocytes (CTLs) on syngeneic tumor cells could be observed in B(7 - 1) group (15.0%) or IL-12 group (31.5%) (P < 0.05 or P < 0.01, compared with 2.6% in control group), while coexpression of IL-12 and B(7 - 1) was of great importance in enhancing CTL activity (52.4%), compared with that in control or B(7 - 1) or IL-12 group (P < 0.05, respectively). The life spans of ovarian cancer-bearing rats immunized by IL-12 (59.8 d) or B(7 - 1) (56.2 d) tumor cell vaccines were a little longer than that in control group (53.4 d), but no significant differences existed (P > 0.05), whereas in the animal models who had received IL-12 and B(7 - 1) co-immunization, prolonged survival time was showed which had statistical significance compared with that in control group (66.0 d, P < 0.05). CONCLUSION: B(7 - 1) and IL-12 modified tumor cell vaccines can induce anti-tumor immunity through stimulating lymphocytes proliferation and inducing recognition and cytotoxic effects of CTLs on tumor cells. An obvious synergistic effect exists when the two cytokines are combined. Combined immunogenic therapy with IL-12 and B(7 - 1) should prove to be a promising therapeutic strategy in ovarian cancer.

Abdominal Neoplasms↗

PubMed2003

[Treatment of ovarian cancer cell line Skov3 with HSV-tk/GCV under the control of human telomerase reverse transcriptase gene promoter].

OBJECTIVE: To investigate the in vitro effect of HSV-tk/GCV using a hTERT promoter-driven vector system on Skov3 ovarian cancer cells. METHODS: An expression vector (pBTdel-279-tk) containing tk gene under the hTERT promoter was constructed by molecular biological methods, and then was transfected into Skov3 ovarian cancer cells, normal ovarian epithelial cells (NOEC) and human embryonic lung fibroblast by cationic liposome. Following the transfection with tk, GCV was added, and MTT and flow cytometry methods were applied to investigate its antitumor effect. RT-PCR was used to detect the tk gene in ovarian cancer cells and normal cells after the transfection of pcDNA3-tk or pBTdel-279-tk. RESULTS: pBTdel-279-tk/GCV system induced apoptosis in hTERT-positive ovarian cancer cells, but not in hTERT-negative normal ovarian epithelial cells and fibroblasts. The hTERT promoter system was almost as efficient in inducing cancer cell death as the CMV promoter. tk gene was expressed in Skov3 cells and NOEC after pcDNA3-tk transfection, while positive was only in ovarian cancer cells after pBTdel-279-tk transfection. CONCLUSION: The telomerasespecific transfer of the tk gene under the hTERT promoter is a novel targeting approach for the treatment of ovarian cancer and may lead to an effective and specific gene therapy.

Apoptosis↗