Immunotherapy of tumors with xenogeneic endothelial cells as a vaccine

The breaking of immune tolerance against autologous angiogenic endothelial cells should be a useful approach for cancer therapy. Here we show that immunotherapy of tumors using fixed xenogeneic whole endothelial cells as a vaccine was effective in affording protection from tumor growth, inducing regression of established tumors and prolonging survival of tumor-bearing mice. Furthermore, autoreactive immunity targeting to microvessels in solid tumors was induced and was probably responsible for the anti-tumor activity. These observations may provide a new vaccine strategy for cancer therapy through the induction of an autoimmune response against the tumor endothelium in a cross-reaction.

Immunogene therapy of tumors with vaccine based on Xenopus homologous vascular endothelial growth factor as a model antigen

Overcoming immune tolerance of the growth factors associated with tumor growth should be a useful approach to cancer therapy by active immunity. We used vascular endothelial growth factor (VEGF) as a model antigen to explore the feasibility of the immunogene tumor therapy with a vaccine based on a single xenogeneic homologous gene, targeting the growth factors associated with angiogenesis. To test this concept, we constructed a plasmid DNA encoding Xenopus homologous VEGF (XVEGF-p) and control vectors. We found that immunogene tumor therapy with a vaccine based on XVEGF was effective at both protective and therapeutic antitumor immunity in several tumor models in mice. VEGF-specific autoantibodies in sera of mice immunized with XVEGF-p could be found in Western blotting analysis and ELISA assay. The purified immunoglobulins were effective at the inhibition of VEGF-mediated endothelial cell proliferation in vitro, and at antitumor activity and the inhibition of angiogenesis by adoptive transfer in vivo. The elevation of VEGF in the sera of the tumor-bearing mice could be abrogated with XVEGF-p immunization. The antitumor activity and production of VEGF-specific autoantibodies, significantly elevated IgG1 and IgG2b, could be abrogated by the depletion of CD4(+) T lymphocytes. The observations may provide a vaccine strategy for cancer therapy through the induction of autoimmunity against the growth factors associated with tumor growth in a cross reaction with single xenogeneic homologous gene and may be of importance in the further exploration of the applications of other xenogeneic homologous genes identified in human and other animal genome sequence projects in cancer therapy.

Chloroquine inhibits colon cancer cell growth in vitro and tumor growth in vivo via induction of apoptosis

The present study was to investigate the anticancer effect of chloroquine on proliferation of mouse colon cancer cell line CT26 in vivo and in vitro and the possible mechanism. We found that chloroquine inhibited CT26 proliferation by concentration- and time-dependent manner. This effect was associated with apoptosis induction and decreased level of phosphorylated p42/44 mitogen-activated protein kinase and phosphorylated Akt. The in vivo study showed chloroquine-reduced tumor volume and prolonged survival time in CT26-bearing mice. These observations indicated chloroquine could inhibit CT26 proliferation by inducing apoptosis both in vitro and in vivo, providing its chemotherapeutic potential of human cancers.

Prophylaxis against carcinogenesis in three kinds of unestablished tumor models via IL12-gene-engineered MSCs

Mesenchymal stem cells (MSCs) were adenovirally engineered to secrete interleukin-12 (AdIL-12-MSCs) and evaluated for their anticarcinogenesis efficacy against three kinds of unestablished tumor models including B16 melanoma, LLC Lewis lung cancer and HCC hepatoma. Injection of AdIL-12-MSCs into protected mice before tumor inoculation prevented all of 12 mice in B16 preventive groups, 10 out of 12 in LLC lung cancer model and 11 out of 12 mice in HCC hepatoma model from developing tumors, whereas the control groups pre-receiving PBS were validated for 100% carcinogenesis; the tumor formation rates in free-AdIL-12 and vacant MSC groups were unveiled between approximately 83 and 100% even with plentiful angiogenesis and newborn lymphatic vessels, as well as distant metastases. As a novel approach, AdIL-12-MSC has revealed expected preventive effects on carcinogenesis (P<0.01) with low-toxic, broad-spectrum and long-range superiorities. In conclusion, our data indicate that AdIL-12-MSC possess the potential for tropism to preclinical tumor lesions and deprives surviving or hibernating tumor cells, which have escaped from conventional treatments, of revival and recurrence.

Cell growth inhibition, G2/M cell cycle arrest, and apoptosis induced by chloroquine in human breast cancer cell line Bcap-37

Chloroquine is an antimalarial drug that has been used in the treatment and prophylaxis of malaria since the 1950s. The present study was undertaken to examine the effects of chloroquine on Bcap-37 human breast cancer cells' growth, cell cycle modulation, apoptosis induction, and associated molecular alterations in vitro. The chloroquine treatment decreased the viability of Bcap-37 cells in a concentration- and time-dependent manner, which correlated with G(2)/M phase cell cycle arrest. The chloroquine-mediated cell cycle arrest was associated with a decrease in protein levels/activity of polo-like kinase 1 (Plk1), phosphorylated cell division cycle 25C (Cdc25C), phosphorylated extracellular signal-regulated kinase 1/2 (ERK1/2), phosphorylated Akt. The chloroquine-treated Bcap-37 cells exhibited a marked decrease in the level of mitochondrial transmembrane potential (DeltaPsim), which was accompanied by the activation of caspase-3 and cleaved poly(ADP-ribose) polymerase (PARP). Exposure of Bcap-37 cells to chloroquine also resulted in the induction of spindle abnormalities. In conclusion, the findings in this study suggested that chloroquine might have potential anticancer efficacy, which could be attributed, in part, to its proliferation inhibition and apoptosis induction of cancer cells through modulation of apoptosis and cell cycle-related proteins expressions, down-regulation of mitochondrial transmembrane potential (DeltaPsim), and induction of spindle abnormalities.

Immunogene therapy of tumors with vaccine based on xenogeneic epidermal growth factor receptor

The breaking of immune tolerance against self epidermal growth factor receptor (EGFr) should be a useful approach for the treatment of receptor-positive tumors with active immunization. To test this concept, we constructed a plasmid DNA encoding extracellular domain of xenogeneic (human) EGFr (hEe-p) or corresponding control mouse EGFr (mEe-p) and empty vector (c-p). Mice immunized with hEe-p showed both protective and therapeutic antitumor activity against EGFr-positive tumor. Sera isolated from the hEe-p-immunized mice exhibited positive staining for EGFr-positive tumor cells in flow cytometric analysis and recognized a single 170-kDa band in Western blot analysis. Ig subclasses responded to rEGFr proteins were elevated in IgG1, Ig2a, and Ig2b. There was the deposition of IgG on the tumor cells. Adoptive transfer of the purified Igs showed the antitumor activity. The increased killing activity of CTL against EGFr-positive tumor cells could be blocked by anti-CD8 or anti-MHC class I mAb. In vivo depletion of CD4(+) T lymphocytes could completely abrogate the antitumor activity, whereas the depletion of CD8(+) cells showed partial abrogation. The adoptive transfer of CD4-depleted (CD8(+)) or CD8-depleted (CD4(+)) T lymphocytes isolated from mice immunized with hEe-p vaccine showed the antitumor activity. In addition, the increase in level of both IFN-gamma and IL-4 was found. Taken together, these findings may provide a new vaccine strategy for the treatment of EGFr-positive tumors through the induction of the autoimmune response against EGFr in a cross-reaction between the xenogeneic homologous and self EGFr.

Co-delivery of doxorubicin and plasmid by a novel FGFR-mediated cationic liposome

In our previous study, we developed a novel cationic liposome, which was modified with truncated human basic fibroblast growth factor (tbFGF) peptide. This tbFGF-mediated cationic liposome could deliver chemotherapeutic agents or gene specifically to FGFRs on tumors and obtained higher transfection efficiency than plain cationic liposomes. In order to investigate whether this novel cationic liposome could achieve a synergistic/combined anti-tumor effect as a co-delivery system, we simultaneously delivered doxorubicin (DOX) and the plasmid encoding the phosphorylation-defective mouse survivin threonine 34-->alanine mutant (Msurvivin T34A plasmid) to the same cells through this cationic liposome. As a result, an enhanced antiproliferative activity in vitro has been achieved by delivering DOX and DNA simultaneously to the Lewis lung carcinoma cells (LLC) using this liposome. The concentration of DOX in the co-delivery system which caused 50% killing was nearly 3-fold lower than that of the free DOX. Furthermore, the co-delivery system suppressed tumor growth more efficiently than either DOX or the Msurvivin T34A plasmid alone in the Lewis lung carcinoma-bearing C57BL/6 mice. After 18 days of treatment with the co-delivery system, the average tumor volume in mice was decreased by 80%, which was higher than liposomal DOX (70%, P<0.05) and Msurvivin T34A plasmid (41%, P<0.01). The co-delivery system also caused 15 days delay of tumor growth, which was longer than the other treatment groups. In conclusion, this novel cationic liposome is an efficient vector to simultaneously deliver drugs and DNA to the same cells in vitro and in vivo.

Hepatitis B virus X protein (HBx) induces G2/M arrest and apoptosis through sustained activation of cyclin B1-CDK1 kinase

Hepatitis B virus X protein (HBx) is a multi-functional regulatory protein that is known to be involved in viral proliferation, transcriptional activation and cell growth control. However, the actual role of HBx in cell growth control remains controversial. In this study, the impact of HBx on cell growth in vitro and in vivo was further investigated. HBx was able to inhibit the growth of hepatocellular carcinoma (HCC) cells and induce G2/M arrest in vitro. Moreover, unlike many other G2/M arrest mechanisms, HBx did not inhibit cyclin B1-CDK1 kinase activity, but it persistently activated the cyclin B1-CDK1 kinase. In vivo, HBx inhibited tumor cell growth and induced apoptosis as well as inhibited the growth of vascular endothelial cells. In conclusion, HBx induced G2/M arrest and apoptosis through sustained activation of cyclin B1-CDK1 kinase, and negatively regulated cell growth in vitro and in vivo.

Systemically administered liposome-encapsulated Ad-PEDF potentiates the anti-cancer effects in mouse lung metastasis melanoma

BACKGROUND

The use of adenoviral vector for gene therapy is still an important strategy for advanced cancers, however, the lack of the requisite coxsackie-adenovirus receptor in cancer cells and host immune response to adenovirus limit the application of adenoviral vector in vivo.

METHOD

We designed the antiangiogenic gene therapy with recombinant PEDF adenovirus (Ad-PEDF) encapsulated in cationic liposome (Ad-PEDF/Liposome), and investigated the anti-tumor efficacy of Ad-PEDF/Liposome complex on inhibition of tumor metastasis.

RESULTS

We found that systemic administration of Ad-PEDF/liposome was well tolerated and resulted in marked suppression of tumor growth, and was more potent than uncoated Ad-PEDF to induce apoptosis in B16-F10 melanoma cells and inhibit murine pulmonary metastases in vivo. After Ad-luciferase was encapsulated with liposome, its distribution decreased in liver and increased in lung. The anti-Ad IgG level of Ad-PEDF/Liposome was significantly lower than Ad-PEDF used alone.

CONCLUSION

The present findings provide evidences of systematic administration of cationic liposome-encapsulated Ad-PEDF in pulmonary metastatic melanoma mice model, and show an encouraging therapeutic effect for further exploration and application of more complexes based on liposome-encapsulated adenovirus for more cancers.

Quercetin Liposome Sensitizes Colon Carcinoma to Thermotherapy and Thermochemotherapy in Mice Models

Thermotherapy and thermochemotherapy have been used in clinics to treat patients with malignant diseases, including colon cancer, and their efficacy has been well proved. Heat shock proteins (HSPs), especially Hsp70, play important roles in neutralizing their efficacy. It has been reported that quercetin can suppress cancer by inhibiting the intratumoral expression of Hsp70. This study was designed to investigate whether quercetin could enhance sensitivity to thermotherapy and thermochemotherapy. Soluble quercetin liposome was used in this study. The effects of quercetin were investigated in vitro and in mouse colon cancer models of subcutaneous tumor and peritoneal carcinomatosis. The results showed that quercetin liposome inhibited the upregulation of Hsp70 and enhanced apoptosis induced by hyperthermia and thermochemotherapy. Systemic administration of quercetin liposome can sensitize CT26 cells to thermotherapy and chemothermotherapy. This study suggests that quercetin liposome might be potentially applied for clinical cancer therapy.

Improved therapeutic efficacy against murine carcinoma by combining honokiol with gene therapy of PNAS-4, a novel pro-apoptotic gene

PNAS-4, a novel pro-apoptotic gene activated during the early response to DNA damage, can inhibit proliferation via apoptosis when overexpressed in some tumor cells. Recent studies have indicated that honokiol can induce apoptosis, inhibit angiogenesis, and suppress tumor growth. In the present study, we investigated whether mouse PNAS-4 (mPNAS-4) could augment the apoptosis of tumor cells induced by honokiol in vitro, and whether the antiangiogenic activity of honokiol and induction of apoptosis by mPNAS-4 could work cooperatively to improve the antitumor efficacy in vivo. In vitro, mPNAS-4 inhibited proliferation of murine colorectal carcinoma CT26 and Lewis lung carcinoma LL2 cells through induction of apoptosis, and significantly augmented the apoptosis of CT26 and LL2 cells induced by honokiol. Compared with treatment with mPNAS-4 or honokiol alone, in vivo systemic administration of an expression plasmid encoding mPNAS-4 and low-dose honokiol significantly suppressed tumor growth through the enhanced induction of apoptosis and the augmented inhibition of angiogenesis. Our data suggest that the combined treatment with mPNAS-4 plus honokiol augments antitumor effects in vitro and in vivo, and that the improved antitumor activity in vivo may be associated with enhanced induction of apoptosis and augmented inhibition of angiogenesis. The present study may provide a novel and effective method for the treatment of cancer.

PNAS-4, a novel pro-apoptotic gene, can potentiate antineoplastic effects of cisplatin

PURPOSE

PNAS-4, a novel pro-apoptotic gene activated during the early response to DNA damage, can inhibit proliferation via apoptosis when overexpressed in some tumor cells. The objectives of this study were to determine whether PNAS-4 could enhance apoptosis induced by cisplatin besides its induction of apoptosis, and to evaluate the usefulness of combined treatment with mouse PNAS-4 (mPNAS-4) gene therapy and low-dose cisplatin chemotherapy in the inhibition of tumor growth in colon carcinoma (CT26) and Lewis lung carcinoma (LL/2) murine models.

METHODS

In this study, the in vitro growth-inhibitory and pro-apoptotic effects of PNAS-4 and/or cisplatin on CT26, LL/2, and SKOV3 cancer cells were assessed by MTT assay, flow cytometric analysis, DNA fragmentation, and morphological analysis, respectively. The in vivo antitumor activity of combined treatment with mPNAS-4 gene therapy and low-dose cisplatin were evaluated in the inhibition of tumor growth in colon carcinoma (CT26) and Lewis lung carcinoma (LL/2) murine models. Tumor volume and survival time were observed. Induction of apoptosis was also assessed in tumor tissues.

RESULTS

In vitro, PNAS-4 inhibited proliferation of colon carcinoma (CT26), Lewis lung carcinoma (LL/2) and human ovarian cancer (SKOV3) cell lines via apoptosis, and significantly enhanced the apoptosis of CT26, LL/2, and SKOV3 cells induced by cisplatin. In vivo systemic administration of expression plasmid encoding mPNAS-4 (pcDNA3.1-mPS) and cisplatin, significantly decreased tumor growth through increased tumor cell apoptosis compared to treatment with mPNAS-4 or cisplatin alone.

CONCLUSIONS

Our data suggests that the combined treatment with mPNAS-4 plus cisplatin may augment the induction of apoptosis in tumor cells in vitro and in vivo, and that the augmented antitumor activity in vivo may result from the increased induction of apoptosis. The present study may provide a novel way to augment the antitumor efficacy of cytotoxic chemotherapy.

Immunohistochemical study of the relationship between extracellular matrix and root bifurcation in the mouse molar

In order to investigate epithelial-mesenchymal interaction during root bifurcation, the distribution of type III and I collagen, fibronectin and laminin in the epithelial-mesenchymal junction between the dental epithelia (epithelial diaphragm and interradicular process) and the cells of the dental papilla (or pre-odontoblasts) was examined, using maxillary first molar tooth germs of CF1 mice from day 1-16 after birth. Three-dimensional reconstructions of the immunofluorescent patterns were made from serial sections of tooth germs from day 3-9, stained with the antibodies against the collagens. The findings were as follows. (1) Type III collagen was first seen in the epithelial-mesenchymal junction at the tip of the interradicular process, where it sprouted from the epithelial diaphragm, and spread along the interradicular process toward its base, accompanied its extension, and then disappeared on completion of root bifurcation. No staining was seen in the epithelial-mesenchymal junction at the epithelial diaphragm during and after root bifurcation. (2) Type I collagen appeared in the epithelial-mesenchymal junction at the base of the interradicular process, where it sprouted from the epithelial diaphragm and spread toward the tip of the interradicular process, following its extension, and increased on completion of the root bifurcation. No staining was seen in the epithelial-mesenchymal junction at the epithelial diaphragm during or after root bifurcation. (3) Fibronectin and laminin remained constant in the epithelial-mesenchymal junction, both at the interradicular process and the epithelial diaphragm, during and after root bifurcation. These findings suggest that type III collagen may play a significant role in the early stage of root bifurcation in the molar.

Antitumour activity of cationic-liposome-conjugated adenovirus containing the CCL19 [chemokine (C-C motif) ligand 19] gene

CCL19 [chemokine (C-C motif) ligand 19; also known as MIP-3beta (macrophage inflammatory protein-3beta) or ELC (Epstein-Barr-virus-induced molecule 1 ligand chemokine)], one of the immunostimulatory cytokines, chemoattracts both DCs (dendritic cells) and T-lymphocytes. Adenoviral vector is one of the most used gene delivery vectors for cancer therapy because of its high gene-transfection efficiency. However, its wider application is limited, owing to immune responses that reduce transgene expression and decrease the efficacy of repeated administration. We constructed the recombinant replication deficient adenoviral vectors containing the CCL19 gene (Ad-CCL19) and combined them with PEG-PE [poly(ethylene glycol)-phosphatidylethanolamine]-modified cationic liposomes (Ad-CCL19/PEG-PE) for immunotherapy against murine fibrosarcoma. Although there were hardly any therapeutic differences between Ad-CCL19- and Ad-CCL19/PEG-PE-treated mice that were observed at the second administration, the final results demonstrated that Ad-CCL19/PEG-PE-treated mice survived much longer. The antitumour efficacy may be related to the high level of CCL19 after the final administration and lasting expression of IFN-gamma (interferon-gamma) and IL-12 (interleukin-12) in the Ad-CCL19/PEG-PE-treated group, which were measured by reverse-transcription PCR and ELISA. The results demonstrated that PEG-PE-cationic-liposome-conjugated adenovirus could prolong the expression of the therapeutic gene in vivo and may enhance the antitumour efficacy.

A novel strategy for tumour therapy combining cell apoptosis and active immunity induced by caspy2, a zebrafish caspase

Caspy2, a zebrafish protease, is an active caspase for inducing apoptosis in mammalian cells. To investigate whether caspy2-mediated apoptosis could be used in cancer therapy, its cDNA was amplified and cloned into eukaryotic expression vector pcDNA3.1(+). The recombinant plasmid was mixed with cationic liposome and introduced into various tumour cell lines in vitro. Our data showed that caspy2 induced remarkable apoptosis of cancer cells in vitro. Treatment of mice-bearing CT26 colon carcinoma or MethA fibrosarcoma with intratumoral injection of liposome-caspy2 plasmid complex resulted in substantial killing of neoplastic cells and long-term survivors. Apoptotic cells were widely distributed in caspy2-treated tumour tissue. Infiltration of CD8(+) T lymphocyte was also observed apparently in the tumour tissue after the treatment with caspy2. Tumour-specific major histocompatibility complex (MHC) class I-dependent CD8(+) cytotoxic T lymphocyte activity was found by means of (51)Cr release assay. In MethA model, the mice acquired a long-time protective immunity against the parental tumour cell re-challenge. These results indicated that caspy2 can act as both apoptosis inducer and immune response initiator, which may account for its extraordinary antitumour effect. Furthermore, in vivo depletion of CD8(+) T lymphocytes could completely abrogate the antitumour immune activity, whereas the depletion of CD4(+) cells showed partial abrogation. In this study, we developed a novel anticancer strategy that combines both induction of apoptosis and immune response in mice-bearing tumours with a single caspy2 gene. This approach may provide an important way for treatment of cancer.

Association between TNF-α rs1799724 and rs1800629 polymorphisms and the risk of Crohn's disease

We investigated the associations between 2 major tumor necrosis factor-α (TNF-α) polymorphisms, rs1799724 C>T and rs1800629 G>A, and the susceptibility to Crohn's disease (CD) using a meta-analysis framework. The PubMed, EBSCO, Ovid, Wiley, Web of Science, WANFANG, and VIP databases (last updated search in October 2014) were comprehensively searched for relevant published studies. The studies retrieved from database searches were filtered based on inclusion and exclusion criteria, and the resultant data extracted from the selected studies were analyzed using the Comprehensive Meta-analysis 2.0 software. Eleven case-control studies, containing 2000 CD patients and 3499 healthy controls, were identified as relevant to this meta-analysis. Data extracted from these 11 studies were analyzed to understand the role of the 2 TNF-α polymorphisms in CD. We found that the TNF-α rs1799724 C>T polymorphism increased the susceptibility to CD (allele model: OR = 1.293, 95%CI = 1.090-1.534, P = 0.003; dominant model: OR = 1.258, 95%CI = 1.031-1.534, P = 0.024). In contrast, we found no significant association between the TNF-α rs1800629 G>A polymorphism and CD susceptibility (allele model: OR = 1.005, 95%CI = 0.864-1.170, P = 0.945; dominant model: OR = 0.962, 95%CI = 0.809-1.145, P = 0.667). This meta-analysis showed that the TNF-α rs1799724 C>T polymorphism is associated with CD susceptibility, while the TNF-α rs1800629 G>A polymorphism appeared to have no correlation with the susceptibility to CD.

Treatment of skin injury due to vinorelbine extravasation using bFGF and rhGM-CSF: an experimental study in a murine model

BACKGROUND AND OBJECTIVE

A murine model of skin injury from vinorelbine extravasation was established to evaluate the treatment efficacy of basic fibroblast growth factor (bFGF) and recombinant human granulocyte-macrophage colony-stimulating factor (rhGM-CSF).

MATERIALS AND METHOD

Experimental models were divided into bFGF, rhGM-CSF, and control (saline) groups, with 40 mice in each group. Edema and ulceration were measured on Days 1, 3, 5, 7, 10, 14, and 18 after the onset of extravasation; injuries were examined pathomorphologically in three mice/group/time point.

RESULTS

Edema reached maximum size on Day 3 in the bFGF and rhGM-CSF groups and Day 5 in the control group. The difference between the two experimental groups was not significant; differences between the control group and the experimental groups were statistically significant at all time points. Edema and ulceration began to improve on Day 10 in the bFGF and rhGM-CSF groups and Day 18 in the control group. Healing duration was 14-18 days in the experimental groups, with a (not significantly) shorter duration in the bFGF group. Healing was completed by Day 27.5 in the control group. Pathomorphological evaluation showed regular re-epithelization and newly formed granulation tissue in the bFGF and rhGM-CSF groups on Day 13. In the control group, wounds were partially healed, edema and shallow ulcers existed, and epithelization was fragile and disorganized on Day 18.

CONCLUSIONS

bFGF and rhGM-CSF are useful for the treatment of skin injury due to vinorelbine extravasation, but bFGF may be slightly more effective in decreasing time and improving quality of healing.

SKLB70326, a novel small-molecule inhibitor of cell-cycle progression, induces G₀/G₁ phase arrest and apoptosis in human hepatic carcinoma cells

We previously reported the potential of a novel small molecule 3-amino-6-(3-methoxyphenyl)thieno[2.3-b]pyridine-2-carboxamide (SKLB70326) as an anticancer agent. In the present study, we investigated the anticancer effects and possible mechanisms of SKLB70326 in vitro. We found that SKLB70326 treatment significantly inhibited human hepatic carcinoma cell proliferation in vitro, and the HepG2 cell line was the most sensitive to its treatment. The inhibition of cell proliferation correlated with G(0)/G(1) phase arrest, which was followed by apoptotic cell death. The SKLB70326-mediated cell-cycle arrest was associated with the downregulation of cyclin-dependent kinase (CDK) 2, CDK4 and CDK6 but not cyclin D1 or cyclin E. The phosphorylation of the retinoblastoma protein (Rb) was also observed. SKLB70326 treatment induced apoptotic cell death via the activation of PARP, caspase-3, caspase-9 and Bax as well as the downregulation of Bcl-2. The expression levels of p53 and p21 were also induced by SKLB70326 treatment. Moreover, SKLB70326 treatment was well tolerated. In conclusion, SKLB70326, a novel cell-cycle inhibitor, notably inhibits HepG2 cell proliferation through the induction of G(0)/G(1) phase arrest and subsequent apoptosis. Its potential as a candidate anticancer agent warrants further investigation.

[Effect of quercetin on the signal pathway of TGFbeta1 in activated hepatic stellate cells]

OBJECTIVE

To investigate the effect of quercetin on the expression of connective tissue growth factor (CTGF) and fibronectin (FN) in hepatic stellate cells (HSCs) stimulated with transforming growth factor (TGF)beta1.

METHODS

HSCs of rat were isolated by in situ perfusion and gradients centrifugation; the activated HSCs were incubated with quercetin (10(-9)-10(-5) mol/L) for 24, 48 and 72 h. TGFbeta1 was detected by flow cytometry. The expression of CTGF was detected by reverse transcription-polymerase chain reaction (RT-PCR), and then FN was detected by immunohistochemistry.

RESULTS

Quercetin (10(-8) to 10(-5) mol/L) inhibited the expression of TGFbeta1 in HSCs. TGFbeta1 expression decreased after the HSCs being incubated with quercetin (10(-7) mol/L) for 48 h (mean fluorescence: 13.33+/-2.44 and 18.08+/-2.54, t=16.52, P<0.01). TGFbeta1 increased the expression of CTGF mRNA in HSCs, but this effect was abrogated by quercetin (10(-7) mol/L) within 72 h. Quercetin (10(-7) mol/L) significantly inhibited the expression of FN in HSCs.

CONCLUSION

Quercetin may have an inhibitory effect on the signal pathways of TGFbeta1, including the expression of TGFbeta1, FN and CTGF.

[Preparation and transfection of GFP plasmid DNA/cationic liposome complex]

OBJECTIVE

This work was directed at obtaining a better gene carrier to improve the effects of gene delivery.

METHODS

Cationic liposomes made from cholesterol, lecithin and Eighteenth Amic by reverse evaporation technique were used for encapsulating plasmid DNA containing gfp gene. The DNA/liposome complexes differed in quantity of plasmid DNA. The sizes of complexes and the efficiency of encapsulation were detected. MTT assay was used to measure the cytotoxicities of complexes. The efficiency of transfection into COS1 cells was shown by observation of green fluorescent and measurement of fluorescent intensity.

RESULTS

The average size of complexes was 562 nm, the encapsulating efficiency of DNA in microspheres reached 55%-65%. These DNA/Cationic liposome complexes could be transfected into mammalian cells, but they were different from each other in efficiency of transfection. The cytotoxicities of these complexes varied with the concentration of DNA in complexes, the quantities of complexes and the time of treatment by complexes.

CONCLUSION

DNA/Cationic liposome complexes prepared by reverse evaporation technique could be applied in DNA delivery system.

[Antitumoral efficacy by systemic delivery of cationic liposome-plasmid interleukin-15 complexes in murine models of lung metastasis]

AIM

To investigate the therapeutic effect of the plasmid pcDNA3.1-IL15 complexed with cationic liposome (CL-IL15) in the B16-F10 melanoma lung metastasis model.

METHODS

A plasmid with high secretive efficiency of IL-15 was constructed and the optimum mix ratio was determined to formulate cationic liposome-plasmid complex with the optimal encapsulation. The CHO-K1 cell line was transfected by CL-IL15. The secretion of transfected IL-15 gene was detected by Western blot and its biological function was measured through the proliferation response of CTLL-2 cytotoxic T cell line of murine by MTT assay. The C57BL/6 mice were inoculated intravenously (i.v.) with B16-F10 melanoma lung metastasis cells then treated (i.v.) by CL-IL15 in a therapeutic setting to determine the tumorigenesis and research the corresponding mechanisms.

RESULTS

The pcDNA3.1-IL15 plasmid was successfully constructed and the mass-ratio of optimal condition of cationic liposome-plasmid with perfect entrapment was 1:5 (plasmid: cationic liposome). Western blot analysis displayed the detection of IL-15 both in the medium and the pcDNA3.1-IL15 transfected cells. MTT assay showed that CTLL-2 cells could proliferate with the medium obtained from CHO-K1 cells transfected by CL-IL15. And the administration of CL-IL15 complexes led to the significant inhibition lung metastasis of malignant melanoma (P<0.05).

CONCLUSION

CL-IL15 could inhibit the metastasis of malignant melanoma and the cationic liposome delivered plasmid pcDNA3.1-IL-15 complexes may be an efficient therapeutic strategy for the treating of lung metastasis. And the effective splenic cell-mediated cytotoxicity and the obvious NK cells recruitment may be involved.

[Effects of isoprenaline on apoptosis related gene expression in rat myocardium cells]

AIM

To study the relationship between acute myocardial ischemia rat induced by isoprenaline (Iso) and expression of some apoptosis related genes in myocardium.

METHODS

Acute myocardial ischemic rat model was induced by subcutaneous injection of large doses of Iso. The myocardial expression of apoptosis related genes, Fas, CPP32, Bcl-2 and Bax, were detected with RT-PCR method. The influences of aloperine (Alo, 20 mg.kg-1) and propranolol (Prop, 2 mg.kg-1) on apoptosis related genes were also investigated by the same method.

RESULTS

Myocardial expression of Fas, CPP32 and Bcl-2 were increased in acute myocardial ischemic rats, but no significance was detected in Bax expression. Both Alo and Prop were shown to decrease the expression of Fas and CPP32, and increase expression of Bcl-2. Prop also showed down regulated effect on expression of Bax.

CONCLUSION

Subcutaneous injection of large doses of Iso was shown to induce expressions of apoptosis related genes in rat myocardium, which were also influences by Alo and Prop.