EXPERIMENTAL STUDY ON PREGNANCY-TERMINATION EFFECT OF CURCUMA AROMATICA

Curcuma Aromatica in the form of decoc-tion administered intraperitoneally or subcuta-neously at the daily dosage of 5-10 g/kg for 2-3days to rabbits in various stages of gravidity,terminated it.The drug was less effective whenused orally.The LD_(50) of the herb in mice was33.7±3.1g/kg when administered in a single i.p.injection.The estrogenic and antiestrogenic activitiesof the herb were negligible.The significantchange observed was marked suppression of thedeciduoma.The termination of early gestationin mice was prevented by simultaneous injectionof progesterone and the herb,suggesting that thepregnancy-termination action of the herb wasprobably due to its antagonistic effect on endo-genous progesterone and the uterine contractioneffect.     

EVALUATION OF THE ANTITUMOR ACTIVITY OF HUMAN IL-4 BY IN VITRO AND IN V1VO ASSAYS

The characteristics of rhuIL-4 induced cytotoxicity was detected in vitro by using ^51 Cr release assay and the anti-tumor activity of rhuIL-4 induced killer cell was evaluated in vivo by using a human tumor model in nudemice.huIL-4 can induce LAK activity from peripheral blood lymphocytes(PBMC) stimulated with phytohemagglutinin(PHA).Compared with the LAK activity induced by rhuIL-2,the cytotoxicity of the killer cells induced by rhuIL-4 to K562 and Raji cells was lower ,but that to TBL-E,a human lymphoid leukemia cell line established in our laboratory,and PHA-activated blast cells(PHA-blasts) was of similar magnitude.In the cytotoxicity assay using PHA-blasts,the addition of PHA increased the IL-4 induced killer cell cytotoxicity by 131%,but had no effect on IL-2-induced ki8ller cell cytotoxicity.This implies that IL-4 mainly induces CTL-like activity,while IL-2 mainly induces NK-like activity,An experimental human tumor model in nude mice was established by injection of TBL-E human leukemia cells.The anti-tumor activity of rhuIL-4 was evaluated by injection of haman LAK cells induced from PHA-blasts by rhuIL-2 rhuIL-4 and human cytokines into tumor-bearing nude mice.The results showed that human LAK cells effectively inhibit the tumorigenicity of TBL-E cells in nude mice with an inhibition rate of 61%.The antitumor effect of rhuIL-2 was better than that of rIL-4 ,and the antitumor effect of rhuIL-2 rhuIL-4 was similar to that of rhuIL-2 ,though the former delayed the occurence of tumors.Our data imply the potential application of human IL-4 in clinic,and provide an animal model to evaluate the anti-tumor activity of human cytokine(s) with species specificity.     

ANTITUMOR EFFECTS OF MONOCLONAL ANTIBODY FAB’FRAGMENT—CONTAINING IMMUNOCONJUGATES

Objective.Using monoclonal antibody(mAb)Fab‘fragment to develop mAb immunoconjugates for cancer.Methods.Fab‘ fragment of mAb 3A5 was prepared by digestion of the antibody with pepsin and then reduced by dithiothreitol(DTT),while Fab‘ fragment of mAb 3D6 was obtained by digestion of the antibody with ficin and subsequently reduced by β-mercaptoethanol.The conjugation between Fab‘ fragment and pingyangmycin(PYM),an antitumor antibiotic,was mediated by dextran T-40.Immunoreactivity of Fab‘-PYM conjugates with cancer cells was determined by ELISA,and the cytotoxicity of those conjugates to cancer cells was determined by clono-genic assay.Antitumor effects of the Fab‘-PYM conjugates were evaluated by subcutaneously transplanted tumors in mice.Results.The molecular weight of Fab‘ fragment was approximately 53 kD,while the average molecular weight of Fab‘-PYM conjugate was 170kD.The Fab‘-PYM conjugates showed immunoreactivity with anti-gen-relevant cancer cells and selective cytotoxicity against target cells.Administered intravenously,Fab‘-PYM conju-gates were more effective aganist the growth of tumors in mice than free PYM and PYM conjugated with intact mAb.Conclusion.Fab‘-PYM conjugate may be capable of targeting cancer cells and effectively inhibiting tumor growth,suggesting its therapeutic potential in cancer treatment.     

Induction of protective antitumor activity of tumor lysate-pulsed dendritic cells vaccine in RM-1 prostate cancer model

Objective： To investigate the antitumor activity of tumor lysate-pulsed dendritic cells vaccine in RM-1 prostate cancer mice model with the survival time of mice calculated and the tumor size measured in DC vaccine therapy. Methods： C57BL/6 mice were immunized on the dorsal flank by s.c. inoculation of Lysate-DC, ova-DC, and non-DC on day -7. On day 0, 2× 10^6cells of RM-1 tumor cells （H-2b） were injected s.c. in C57BL/6 mice pre-treated by s.c. inoculation of modified DCs, correspondingly. DTH assay was performed with modified DCs. In partial test, for the determination of which immune cells were required for antitumor activity, mice were immunodepleted of CD4, CDS, or natural killer （NK） NK1.1 cells with the corresponding monoclonal antibodies. The survival time of nude mice loaded with tumor cells was calculated and the size of tumor measured. Results： In RM-1 mice prostate cancer model, immunized with lysate-DC, compared with ova-DC and non-DC, the pre-infection vaccine resulted in 100% clearance of primary tumors, whereas on day 0 of injection vaccine cleared 40-60% of primary tumors. On day 0, C57BL/6 mice （H-2b） were immunized with Lysate-DC, compared with ova-DC and non-DC by caudal vein injection, then on day 15, RM-1 cells were inoculated. On day 30, average diameters of tumor in different groups of modified DC were 23.7±5.4 mm, 22.1±4.9 mm, 4.3±2.6 mm, respectively. Lysate-DC, compared with ova-DC and non-DC, can greatly depressed RM-1 tumor cell growth （P〈0.01）. The mean survival time of C57BL/6 mice in Lysate-DC, ova-DC and non-DC groups were 15.8±2.6, 16.6±3.2, 39.0±5.6, respectively, and there was a significant difference in the mean survival time in lysate-DC group between ova-DC and non-DC group （P〈0.01）. DTH test showed that lysate-DC could prime T lymphocyte and elicit tumor antigen specific immune response, and over 80% mice in groups of lysate-DC showed obvious swelling in their foot pad. This response was strengthened with repeating inoculation, whereas DTH response was not seen in control group. In vivo depletion of NK cells resulted in a 40-60% reduction in growth suppression within the primary tumor, and depletion of CD4^＋ cells resulted in a 20% reduction in growth suppression. Conclusion： The minor lysate-pulsed dendritic cells vaccine could elicit antitumor activity in RM-1 loaded C57BL/6 mice, and prolong the duration of RM-1 loaded C57BL/6 mice. So DC-based immunotherapy with hormone-refractory prostate carcinoma yielded protective immunity, generated efficient cellular antitumor responses, thereby providing further preclinical support for feasible immunotherapy approaches for prostate cancer.     

CONSTRUCTION OF HU-PBL／SCID CHIMERAS AND DEVELOPMENT OF EBV-RELATED LYMPHOMAS

Objective To construct hu-PBL/SCID chimeras and to investigate the development of lymphoma and oncogenicity of the Epstein-Barr virus (EBV). Methods Human peripheral blood lymphocytes (PBLs) were isolated from healthy adult donors and transplanted intraperitoneally into severe combined immunodeficient (SCID) mice. Mice with hu-PBL engraftment from healthy EBV seronegative donors were injected intraperitoneally with EBV-containing supematant from suspension culture of B95-8 cell line (active infection), whereas mice receiving lymphocytes from healthy EBV seropositive donors were not re-infected with B95-8 derived EBV (latent infection). Pathological examination and molecular analysis were performed on experimental animals and induced neoplasms. Results In the early stage of this experiment, 12 mice died of acute graft-versus-host disease, mortality was 34.3% (12/35 mice) with an average life span of 17.5 days. In 19 survival hu-PBL/SCID chimeric recipients from 12 healthy donors,tumor incidence was 84.2% (16/19 mice). The average survival time of tumor-bearing mice was 65.5 days. EBV-related neoplasms in SCID mice were nodular tumors with aggressive and fatal features. Histological morphology of tumors exhibited diffuse large cell lymphomas. Immunohistochemistry revealed that LCA (CD45) and L26 (CD20) were positive, but both PS1 (CD3) and UCHL-1 (CD45RO) were negative, and EBV products ZEBRA, LMP1, and EBNA2 were expressed in a small number of tumor cells. EB virus particles were seen in the nuclei of some tumor cells by electron microscopy, and EBV DNA could be amplified in the tumor tissues by PCR. In situ hybridization indicated that the nuclei of tumor cells contained human-specific Alu sequence. Conclusions EBV-induced tumors were human B-cell malignant lymphomas. We obtained direct causative evidence dealing with EBV-associated tumor deriving from normal human cells.     

THE EFFECTS OF RETINOIC ACID ON EXPRESSION OF C-MYC, C-FOS IN LEUKEMIC PROMYELOCYTES

The expression of c-myc, c-fos of leukemic promyelocytes (HL-60 and acute promyelocytic leukemia cells) from 18 acute promyelocytic leukemia (APL) patients treated with all-trans retinoic acid (RA) in vitro was studied. There was no expression of c-fos in HL-60 cells and APL cells from 17 patients. But in one case, a slight expression of c-fos in leukemic cells was observed, and the alteration of expression level was found during the treatment of the cells with RA in vitro. The expression of c-myc in HL-60 cells induced by RA was altered, decrease in the early, increase in the middle, and decline in the later stage were found. The c-myc expression in leukemic cells of eighteen APL patients was variable. There was c-myc expression in eleven APL cells, but no expression in the others. The APL cells with c-myc expression were treated with RA in vitro to observe the kinetic changes of c-myc RNA level. The results showed that the expression of c-myc was gradually decreased except in few cases. Using in situ hybridization technique for detecting the alteration of c-myc expression in leukemic cells of two APL patients. the high level of c-myc before RA treatment and low level of c-myc expression after obtaining complete remission induced by RA were found. The possibility of different proto-oncogenes implicated differentiation was discussed.     

Induction of T-cell immunity against leukemia by dendritic cells pulsed with total RNA isolated from leukemia cells

Objectives To assess the feasibility and efficacy of eliciting leukemia-specific T-cell responses in syngeneic mice in vitro and in vivo using dendritic cells (DCs) pulsed with total RNA from leukemia cells.Methods DCs generated from bone marrow culture in vitro in the presence of combined cytokines were pulsed with cellular total RNA isolated from cultured L615 cells by cationic lipid 1,2-dioleoyloxy-3-(trimethylammonium) propane (DOTAP). T-cell responses were evaluated by in vitro proliferation, and cytotoxicity assay. And in vivo immune protection and proghosis of mice with leukemia were studied.Results DCs pulsed with total RNA isolated from cultured L615 cells (DCs/RNA) were remarkably effective in stimulating L615-specific T-cell response in vitro, but did not cross-react with other leukemia cells from syngeneic mice. Vaccination of naive mice with viable DCs/RNA vaccine was able to partly protect from challenge with a lethal dose of live L615 cells, leading to low leukemia incidence and overall survival prolongation. Statistically significant survival was also observed in a low lethal dose of L615-bearing mice that received treatment using viable DCs∕RNA vaccine alone, suggesting that systemic administration of IL-2 could enhance the anti-tumor efficacy of leukemia RNA/DCs vaccine.Conclusions These data support the use of DCs/RNA vaccine as a feasible and effective route to elicit leukemia immunity against unidentified leukemia-associated antigens for treatment of leukemia-bearing animals.     

Expressions of IL-10 on leukemic cells in acute leukemic patients and its significance

Objective: To explore the expressions of IL-10 on leukemic cells in acute leukemia patients and its significance.Methods :The expressions of IL-10 on leukemic cells in thirty patients was measured by indirect immunofluorescence technique. Results:Observed yellow-green bright fluorescence on leukemic cells membrane, the positive rote of cells was 10-80%, there were 18 patients expressing IL-10 (18/30, 60% ) positively, among them 11 with ANLL (11/19, 58% ) and 7 with ALL (7/11, 64% ) respectively while that of peripheral mononucleate cells in control group was 13%. Compared with that in the control group, there was a significant increase of positive rote in ANLL and ALL but with no significant difference between ANLL and ALL. Conclusion: IL-10 secreted by leukemic cells, contributed to the immunosuppressive state at the tumor site. This is probably one of the important mechanisms of acute leukemic escape.     

Therapeutic antitumor response to cervical cancer in mice immunized with U14 v accines transfected with costimulatory B7 gene

Objective To investigate the effect of U14 vaccine transfected with the B7 gene in inducin g antitumor immune response to murine cervical carcinoma in Chinese 615-strain mice.Methods A recombinant retroviral plasmid vector expressing mouse B7-1 gene (pLNSX-mB7) was transfected into 615-strain mouse cervical carcinoma cell line No. 14 (U1 4) by electroporation to set up a highly-expressed mB7-1 U14 cell clonal strai n (B7(+)U14). In vivo experiments: (1) B7(+)U14 vaccine was primed to protect t he 615-strain mice against U14 re-challenge. (2) B7(+)U14 vaccine was injecte d into tumor-bearing mice with different tumor sizes. Lifetimes and tumor s izes were recorded. In vitro cytotoxicity assay: Mice were immunized with B 7(+)U14 or U14 vaccine and 2 weeks later, spleen cells of those mice were cultur ed for 2 days. The cytotoxicity of these cells against U14 was detected by 5-d iphenyl tetrazolium bromide assay.Results We obtained several B7-1 high expression clonal U14 lines. In vivo experiment, we did not find tumor growing in 3 of the 6 mice primed by B7(+)U14 vaccine during their entire life after re-challenge with U14. The other 3 mice develo ped tumors and their average survival time was longer than that of the control g roup (P<0.01). All 6 mice grew tumors in the control group. When the transplanted tumors became palpable, the mice were randomly divided into 3 group s to be injected with B7(+)U14 vaccine. It was effective for tumor-bearing mic e only when the tumor diameters were <3 mm. When the diameters were ≥3 mm, it was not efficacious to inject B7(+)U14 vaccine (P<0.05). In vitro cytotoxicity assay, cytotoxic T lymphocytes induced by B7(+)U14 vaccine h ad a high er cytotoxicity against U14 than that induced by U14 vaccine (F=310.8, P <0.001).Conclusions Vaccines of cervical cancer cells transfected with the costimulatory molecule B7 gene can induce antitumor immune protection in host mice against U14 re-challe nge. This treatment may cure part of the tumor-bearing mice but be restricted by tumor size. The results suggest that transfecting the B7 gene into cervical cancer as a cell vaccine may be an efficient supplementary method to treat cervi cal cancer after operation.     

THE INFLUENCE OF HUMAN SINGLE CHAIN INTELEUKIN-12 GENE TRANSDUCTION ON THE BIOLOGICAL BEHAVIOR OF HEPATOMA 7721 CELLS

Objective. To investigate the anti-tumor effects of human single chain interleukin-12 (hscIL-12). Method. pcDNA/hscIL-12 recombinant was transfected into human hepatic carcinoma cells (7721 cells) by lipofectin method. The 7721/hscIL-12 cells which secrete hscIL-12 stably, were obtained via G418 selection, and in vitro the influence of hscIL-12 gene transduction on the growth of tumor cells was evaluated by cellcycle analysis. In vivo, genetically engineered 7721 cells (7721/hscIL-12, 7721/pcDNA) and parental cells were implanted into BALB/c nude mice, respectively. 7721/pcDNA and 7721/hscIL-12 groups were divided into two sub-groups on day 8: one was administered with hPBL twice, 6 days at interval; the other was given equalvolume of PBS. Mice were sacrificed on day 26, and spleens and tumors were taken out for histologic assay. Results. hscIL-12 produced stably by 7721/hscIL-12 cells had bioactivity, and it was proved by Western blot, immunocytochemistry, and in situ hybridization. In vitro, compared with 7721 and 7721/pcDNA, the7721/hscIL-12 grew much more slowly. FACS assay showed apparent G1 arrest of 7721/hscIL-12 cells. In ani-mal experiment, on day 8 after inoculation, the tumors of 7721 and 7721/pcDNA group were up to 5 -7mm,while those of 7721/hscIL-12 group were 2 -4mm. When treated with hPBL, the tumor of 7721/hscIL-12 groupdisappeared completely. Histologically, the tumors from 7721/hscIL-12 without hPBL treatment had numerouslymphocyte infiltration, the tumor cells displayed depression looking, atrophy, focal necrosis and apoptosis, whereas the tumors of 7721 and 772l/pcDNA groups grew thrivingly.Conclusion. hsclL-12 transduced 7721 cells could induced significant antitumor immune response which resulted in tumor regression totally when the hPBL was inoculated, and also hscIL-12 has certain effects on mice immune system. These findings suggest that hscIL-12 and hscIL-12 gene therapy might have promising prospects in clinical application.     

Experimental Study on the Antitumor Effect of Chicken Anemia Virus vp3 Gene against Liver Carcinoma In Vivo

In order to testify the antitumor effect, especially its effect against liver carcinoma in vivo,of VP3 protein, one kind of protein coded by chicken anemia virus, recombinants pcDNA-vp3 con-taining chicken anemia virus vp3 gene, and control vector pcDNA3 were mixed with murine liver car-cinoma cell lines H22 respectively. The mixture was injected subcutaneously into Balb/C mice. Somedays later, the mice were killed and the solid tumor weighed. The antitumor efficiency was evaluat-ed. The manners of VP3 protein in vivo inducing tumor cell death were identified by using TUNELassay. All the results suggested that the injection of pcDNA-vp3 and H22 mixture resulted in a sig-nificant reduction of tumor growth in mice when compared with the results of control groups.TUNEL assay revealed that VP3 induced apoptosis in vivo. All these indicated that CAV vp3 mightbe a potential new gene in reducing the growth rate of tumor cells in liver carcinoma or in other kindof solid tumors in vivo.     

Antihepatocarcinoma Effect of Solanine and Its Mechanisms

Objective To explore the antitumor effect of solanine and its mechanisms. Methods The in vivo antitumor effect of solanine was observed using models developed through in vivo transplantation of tumor cells; In vitro lines of sensitive antitumor cells were selected from the digestive system using MTT assay; The effect of solanine on cell morphology was observed using transmission electronic microscopy; The morphology of apoptotic cells was observed using Annexin V/PI double staining and laser confocal scanning microscopy (LCSM); The rate of cell apoptosis was measured using Annexin V/PI double staining and flow cytometry; The concentration of intracellular Ca2+ ([Ca2+]i) was determined using Fluo-3/AM staining and LCSM; The membrane potential of cellular mitochondria was determined using TMRE staining and LCSM; The protein expression of Bcl-2 and Bax was measured using immunological marking and LCSM; And the activity of caspase-3 was measured using the colorimetric method. Results Solanine could inhibit the growth of tumor weight in S180 tumor-bearing mice and prolong the survival time of H22 tumor-bearing mice. MTT assay revealed that HepG2 cells were quite sensitive to solanine because solanine could induce morphological changes in HepG2 cells, with the rate of early apoptosis being 4%, 8.5%, and 20.1%, for HepG2 cells treated for 24 h with solanine at concentration of 0.4, 2, and 10 μg/mL, respectively. Solanine could raise the [Ca2+]i and lower the membrane potential. It could reduce the protein expression of Bcl-2 while increase that of Bax, thus increasing the activity of caspase-3. Conclusion The obvious antitumor activity of solanine in human hepatocarcinoma is demonstrated. This inhibitory effect is achieved through solanine decreasing the Bcl-2/Bax ratio, thus increasing [Ca2+]i, which could enhance the enzymatic activity of the caspase family, thus inducing the apoptosis of HepG2 cells.     

Effect and Mechanism of Superantigen Staphylococcal Enterotoxin Therapy for Mouse Gastric Tumor

Summary:The anti-tumor effect and mechanism of the staphylococcal enterotoxin A(SEA)werestudied.The mouse gastric tumor model was produced by subcutaneously inoculating gastric tumorcells(MGC80-3).The experimental group was treated with SEA,and the control group was treatedwith normal saline.The percentage of tumor generation and tumor mass was measured.The resultsshowed that the percentage of the tumor tumor generation in the SEA-treated mice was lower than in thecontrol group,but there was no significant difference(P>0.05).However,the tumor mass in theexperimental group was significantly lighter than in the control group,with the difference bing verysignificant(P<0.001).There were more CD_4~+ T cells and CD_8~+ T cells in the tumor of the micetreated with SEA than those of the control group.SEA has an obvious anti-tumor effect on mice gas-tric tumor.The mechanism might be that SEA induces the effect of superantigen-dependent cell me-diated cytotoxicity to the tumor cells.     

Antitumor effects of interleukin-18 gene-modified hepatocyte cell line on implanted liver carcinoma

Objective To investigate the antitumor effects of intrasplenically transplanted interleukin-18 (IL-18) gene-modified hepatocytes on murine implanted liver carcinoma. Methods Embryonic murine hepatocyte cell line (BNL-CL2) was transfected with a recombinant adenovirus encoding IL-18 and used as delivery cells for IL-18 gene transfer. Two cell lines, BNL-LacZ and BNL-CL2, were used as controls. One week after intrasplenic injection of C26 cells (colon carcinoma line), tumor-bearing syngeneic mice underwent the intrasplenic transplantation of IL-18 gene-modified hepatocyte cell line and were divided into treatment group (BNL IL-18) and control groups (BNL-LacZ and BNL-CL2 ). Two weeks later, the serum levels of IL-18, interferon-γ (IFN-γ), tumor necrosis factor-α (TNF-α) and nitric oxide (NO) in the implanted liver carcinoma-bearing mice were assayed, the cytotoxicity of murine splenic cytotoxic T-lymphocytes (CTLs) was measured, and the morphology of the hepatic tumors was studied to evaluate the antitumor effects of the approach. Results In the treatment group, the serum levels of IL-18, IFN-γ, TNF-α and NO increased significantly. The splenic CTL activity increased markedly (P&lt;0.01) , accompanied by a substantial decrease in tumor volume and the percentage of tumor area and prolonged survival of liver carcinomo-being mice. Conclusions In vivo IL-18 expression by ex vivo manipulated cells with IL-18 recombinant adenovirus is able to exert potent antitumor effects by inducing a predominantly T-cell-helper type 1 (Th1) immune response. Intrasplenic transplantation of adenovirus-mediated IL-18 gene-modified hepatocytes could be used as a targeting treatment for implanted liver carcinoma.     

The Expression and Activity of MMPs Are Increased in Residual Tumor Tissues after the Termination of Immunotherapy

To investigate the invasive ability of the residual tumor cells after immunotherapy and explore the feasible approach suppressing the invasion, mice were inoculated with B16 cells, and then treated by gene therapy with p4-1BBL/psPD-1 or IFN-γ. The production and activities of MMP-9 and MMP-2 in residual tumor tissues were analyzed with gelatin zymography 1 day and 7 days after the termination of the immunotherapy. The production of MMP-9 and MMP-2 by B16 cells treated with IFN-γ was also analyzed. IFN-γ-treated B16 cells were inoculated to mice via subcutaneous injection. The invasion of tumor to muscular tissue was analyzed. Gene therapy with CH50 was used to suppress the invasive growth of tumor. The results showed that the expression and the activities of MMP-9 and MMP-2 were significantly increased 7 days after the end of immunotherapy. The re- sponse of tumor cells to ECM molecules was intensified after the removal of IFN-γ, resulting in significant increase of both the production and activities of MMP-9 and MMP-2, and the increased invasion of tumor. Gene therapy with CH50 effectively suppressed the invasive growth of tumor. It is concluded that the termination of immunotherapy may result in a higher metastatic potential of residual tumor cells. Suppressing tumor invasion by suitable treatment will improve the efficacy of immunotherapy..     

Investigation on the Effects of Soluble Programmed Death-1 （sPD-1）Enhancing Anti-tumor Immune Response

Summary: By using semi-quantitative RT-PCR method, it was found that PD-L1 mRNA but not PD-L2 mRNA was expressed in H22 hepatoma cells and both PD-L1 and PD-L2 mRNAs were expressed in tumor tissues of tumor bearing mice and upregulated as compared with muscle tissues in normal mice and H22 hcpatoma cells. PD-L1 and PD-L2 were also expressed on the surface of the activated T cells. The soluble recombinant sPD-1 expressed from the constructed eukaryotic expression vector could enhance the lysis of tumor cells by lymphocytes stimulated specifically with antigen. The expresssion of sPD-1 by local gcne therapy on the inoculation site of H22 hepatoma cells could inhibit the growth of tumor. The results of this study indicate tbat expression of soluble receptor of negative costimulatory molecules could reduce the inhibitory effect on T cells in tumor microenvironment and enhance the eytotoxicity of T cells on tumor cells. This possibly provides a new method of improving efficacy of tumor gene therapy.     

Effector cells derived from naive T cells used in tumor immunotherapy of mice bearing B16 melanoma

Background Adoptive cell transfer （ACT） immunotherapy has been used clinically for years to treat malignancies.Improving the killing efficiency of effector cells,such as tumor-specific cytotoxic T lymphocytes （CTLs）,is an important component for enhancing the clinical response of cancer immunotherapy.Hence,we explored a novel method for preparing cancer-specific CTLs using naive T lymphocytes.Methods C57BL/6 mice bearing B16 melanoma tumors were pretreated with cyclophosphamide （CTX） by peritoneal injection.The immunosuppressive influence of CTX on tumor regression and the tumor microenvironment was assessed.Naive T cells and T cell pools were isolated via negative selection using immunomagnetic beads.The proliferative potential and cytokine production of different T cell subpopulations were evaluated in vitro.Tumor-specific CTLs derived from naive T cells （naive CD4＋ T cells：naive CD8＋ T cells=2：1） and pooled T cells were generated in vitro,respectively.B16 melanoma-bearing C57BL/6 mice were pretreated with CTX,followed by ACT immunotherapy using dendritic cell-induced CTLs.The homing abilities of the effector cells and interleukin-2 （IL-2）,interferon-y,granzyme B,and perforin mRNA levels in tumor tissues were evaluated,and the change in tumor volume was measured.Results Mice receiving CTX peritoneal pretreatment injections did not display tumor regression compared with control mice.However,a significant downregulation of splenic Tregs and tumor growth factor-β1 （TGF-β1） and interleukin-10 （IL-10） serum levels was observed （P ＜0.05）.Naive T cells showed a stronger proliferative capacity and elevated cytokine production than did pooled T cells （P ＜0.05）.In addition,effector cells generated from naive T cells displayed more potent antitumor activity in vivo than those derived from pooled T cells （P ＜0.05）.Conclusion Effector cells derived from the naive T cells possess a stronger proliferative potential,homing capacity,and enhanced cytokine production,which leads to a superior antitumor response.     

HISTOMORPHOMETRICAL STUDY OF MULTINUCLEATED GIANT CELLS OF GIANT CELL TUMOR OF BON BY AUTOMATIC IMAGE ANALYSIS SYSTEM

The histomorphometry of ten cases of giant cell tumor of bone was studied using an automatic image analysis system and eight criteria of measurements were analysed. The study showed that this system provided a new technique in medical research and that similar multinucleated giant cells in various lesions of bone may be distinguished with bone histomorphometry. This method will form the basis for the reconstruction of three demensional structure of cells.     

STUDY ON ENHANCEMENT OF TUMOR-KILLING EFFECT AND FORMATION OF NEW FLUOROPHORE IN TUMOR CELLS

Hyperthermia (42-44℃) and photosensitizing therapy can destroy S180 tumor cells,reducemalignant ascites and prolong the survival times of mice with carcinomas.The highestcurative effect was observed when using a combination of the two treatments.Heating to44℃ has a greater destructive effect on tumor cells than has heating to 42℃.The resultsshow that this is due to a synergistic interaction between these two treatments.The fluores-cence spectrum of S180 cells was determined before and alter treatment,and the indicationwas that the synergistic effect is probably related to a new fluorescence product;the greaterthe intensity of the new fluorescence、the more marked the synergy of hyperthermia andphotosensitizing therapy.The maximum emission wavelength was 460nm (excitation wave-length 370nm).     

Growth suppression of human lung cancer cells and implanted tumors by adenovirus-mediated transfer of the PTEN gene

This study examined the effects of a recombinant adenovirus AdTEN-EGFP on the proliferation of A549 cells, a human lung carcinoma cell line, in vitro and on the growth of the implanted tumors in the nude mice in vivo, explored the underlying mechanisms and evaluated the in vitro transfection efficiency of Ad-PTEN-EGFP into A549 cells. The expression of Ad-PTEN-EGFP in the A549 cells was determined. The proliferation and the apoptosis rates of the A549 cells with Ad-PTEN-EGFP transfection or not was detected by MTT and flow cytometry. Ad-PTEN-EGFP at different doses was injected intratumorally to the tumor-bearing mice induced by the A549 cells. Tumor sizes were measured on an alternate day. After all the mice were sacrificed, the implanted tumors were removed for routine histological examination, weight test, HE staining and immunohistochemical staining. The expressions of Bax, P16 and P53 in the tumor tissues and those of caspase-3, CD34 and VEGF in the mouse sera were detected. Tumor cell apoptosis was measured by TUNEL method. The results showed that the vitality of the A549 cells after transfection with Ad-PTEN-EGFP declined. The expression of green fluorescent protein was observed under fluorescent microscope. The transfection rate was in excess of 50%. The mRNA and protein expression of PTEN in the transfected cells was confirmed. The proliferation rate of the transfected cells was significantly decreased when compared with that of the non-transfected cells （P〈0.05）. The number of the apoptosi＇s cells was increased in the transfected cells （P〈0.05）. The models of implanted tumors were successfully estab- lished by injection of the A549 cells in the flank of Balb/c nude mice. Administration of Ad-PTEN-EGFP to the tumor-bearing nude mice resulted in a suppression of tumor growth. There were statistically significant differences in the tumor weight and tumor volume between the Ad-PTEN-EGFP-treated group and the control groups （P〈0.05）. In contrast to those in the control groups, tumor tissues in the Ad-PTEN-EGFP-treated group were shown to have typical extensive vacuolar degeneration and massive hemorrhagic necrosis. Apoptotic bodies were also observed in the tumor cells. The expressions of Bax, caspase-3 and P16 were increased （P〈0.05） while those of CD34, VEGF and P53 decreased （P〈0.05） in the Ad-PTEN-EGFP-treated group. It is concluded that Ad-PTEN-EGFP could induce the apoptosis of the A549 cells and inhibit their proliferation. And it could also substantially suppress the tumor growth in the tumor-bearing nude mice and induce apoptosis of the tumor cells as well. These findings carry significant implications for adenovirus vector-based PTEN gene therapies for lung cancers.