Mouse Ascites Research Articles

Development of Neutralizing Monoclonal Antibodies Against VP4 of Rotavirus CC0812-1

The G10P[15] rotavirus CC0812-1 isolated from a diarrheal woman in Wuhan, China, in 2008 is phylogenetically close to the Lanzhou lamb rotavirus (LLR) of a monovalent human rotavirus vaccine produced by the Lanzhou Institute of Biological Products, China, and rotavirus Lamb-NT. This rotavirus can be used as the backbone of the attenuated rotavirus reassortant as a rotavirus vaccine candidate. In this study, rotavirus CC0812-1 was purified from the culture supernatant of CC0812-1-infected MA104 cells and used as antigen to immunize BALB/c mice. Four hybridoma clones were developed secreting antibodies that reacted with CC0812-1, designated as 1B1, 1B8, 1F11, and 1G10, respectively. Western blot analysis indicated that the four monoclonal antibodies (MAbs) were all specific for VP4 of rotavirus CC0812-1. Isotyping revealed that MAbs 1B1, 1B8, and 1G10 belonged to the IgM class, while MAb 1F11 belonged to the IgG1 subclass. A neutralization test demonstrated that the four MAbs all had the capacity to neutralize rotavirus CC0812-1. The neutralizing titers of the BALB/c mice ascites were 1:2048, 1:1024, 1:512, and 1:512 for MAbs 1B1, 1B8, 1F11, and 1G10, respectively.

Electron microscopic examination of group-specific antigens in Rous sarcoma cells (mouse ascites) and in Rous sarcoma virus.

Electron microscopic examination of group-specific antigens in Rous sarcoma cells (mouse ascites) and in Rous sarcoma virus.

The therapeutic function of the chemokine RANTES on the H22 hepatoma ascites model

This study aimed at analyzing the therapeutic function of the chemokine RANTES on the H22 hepatoma ascites model and preliminarily explore the mechanism of RANTES in malignant ascites to provide an important reference for applying chemokines in anti-tumor therapy. The murine H22 hepatoma ascites model was used. Three treatment groups were analyzed: a RANTES treatment group, an IL-2 control group, and an NS control group. Two regimens of early treatment and late treatment were designed, and the therapeutic effect of RANTES on malignant ascites was studied by measuring changes in mouse body weight and abdominal circumference and observing the survival time. The expression of TNF-α, IFN-γ, TGF-β1, and MCP-1 in mouse ascites was detected by ELISA, and the chemotactic function of RANTES on B lymphocytes and T lymphocytes was analyzed by flow cytometry. In the early and late treatment regimens, RANTES could effectively inhibit the increase in mouse body weight and abdominal circumference in the murine H22 hepatoma ascites model. The secretion of TNF-α and IFN-γ, which had anti-tumor effects, was higher in the RANTES treatment group than in the control groups (P < 0.05), whereas the secretion of TGF-β1 and MCP-1, which promoted tumor growth, invasion, and metastasis, was lower than in the control groups (P < 0.05). RANTES had chemotactic effects on CD4(+) and CD8(+) T lymphocytes; therefore, the percentage of CD3, CD4, and CD8 in the mouse ascites in the RANTES treatment group was significantly higher than in the NS control and IL-2 treatment groups, and the CD4/CD8 ratio was also significantly higher. RANTES can effectively inhibit the increase in body weight and abdominal circumference and significantly extend survival time in mice in the H22 hepatoma ascites model.

Abstract 4377: Metronomic oral prodrug of gemcitabine (LY2334737) causes antitumor effects with concomitant increase in intratumoral blood flow

Abstract Metronomic chemotherapy is the regular administration of chemotherapy drugs at relatively low minimally toxic doses without prolonged break periods; it is currently undergoing phase III trial evaluation. Metronomic chemotherapy is thought to cause anti-tumor effects primarily by antiangiogenic mechanisms, both locally by targeting endothelial cells of the tumor neovasculature and systemically by effects on bone marrow derived cells, including circulating endothelial progenitor cells (CEPs). Previous studies have shown reduction of CEPs by metronomic administration of a number of different chemotherapeutic drugs, including cyclophosphamide, paclitaxel, topotecan, and tegafur plus uracil. Here we report results evaluating the properties of metronomic administration of an oral prodrug of gemcitabine LY2334737 (LY) in non tumor-bearing mice, and in preclinical models of human ovarian (SKOV3-13) and breast cancer (LM2-4) xenografts. Through daily gavage (at 6mg/kg/day) the schedules tested were devoid of toxicity and caused anti-tumor effects; however, a suppressive effect on CEPs was not detected. Human SKOV3-13 ovarian cancer cells were grown as ascites in SCID mice; LY monotherapy (6mg/kg/day), as well as LY in combination with metronomic cyclophosphamide (CTX, 20mg/kg/day), caused a significant increase in survival (n=5 mice per group, p&amp;lt;0.05) compared to controls. Human LM2-4 breast cancer cells, implanted orthotopically into SCID mice, were growth inhibited by LY monotherapy (at 6mg/kg/day as well as at 8mg/kg/day; n=5 mice per group, p&amp;lt;0.05). LM2-4 tumors were also growth inhibited by the combination of LY (6mg/kg/day) plus a bolus of CTX (100mg/kg, single dose) followed immediately by a maintenance regimen of metronomic CTX (20mg/kg/day); this combination did not produce any overt toxicity. Unexpectedly metronomic LY administration caused increased intratumoral blood flow, as measured by ultrasound after 1 week and after 4 weeks of continuous treatment, in luciferase-tagged LM2-4 tumor xenografts; and the increase in blood flow coincided with a relative increase in tumor bioluminescence. Paraffin embedded LM2-4 tumor sections from the therapy experiments were further analyzed by Angiogenesis and by Tumor Health Panel analyses; LY monotherapy did not caused any significant changes in tumor hypoxia, or in intratumoral vessel density, compared to controls. These results highlight the possibility of significant anti-tumor effects mediated by metronomic administration of some chemotherapy drugs without a concomitant inhibition of systemic angiogenesis. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 4377. doi:1538-7445.AM2012-4377

Abstract 281: Novel nucleic acid constructs and formulations for treatment of bladder cancer and malignant ascites

Abstract Nucleic acid-based therapeutics offer significant promise in treatment of difficult diseases by providing high sequence specificity against target genes including “non-druggable targets”. Different nucleic acid constructs, single-stranded antisense oligonucleotides, microRNA mimetics, miRNA-specific antagomirs (AntimiR), and double-stranded short-interfering RNAs (siRNAs), provide diverse therapeutic platforms to access targets in treatment of cancer and other diseases. Single-stranded oligonucleotides require additional modifications for increased serum stability, nuclease resistance, and to minimize immune response. Conformationally restricted nucleotide (CRN)-substituted AntimiRs targeting miR-21 and miR-122 demonstrated significant improvement in hybridization affinity with a concomitant increase in potency. A CRN-substituted AntimiR targeting microRNA-122 dosed at up to 50 mg/kg/day over three consecutive days led to a dose-dependent effect on de-repression of downstream liver-specific target genes, Aldolase A (AldoA), Glycogen Synthase I (GYS1) and Solute Carrier Family 7 member 1 (SLC7A1). This CRN-modified AntimiR produced up to a 5-fold increase in AldoA mRNA while demonstrating a good tolerability profile with no body weight changes and normal serum chemistry. Development of therapeutic siRNA constructs can be hampered by off-target effects and cytokine induction. Substitution of unlocked nucleobase analogs (UNAs) at specific positions in the passenger and guide strands of siRNA confers high specificity with minimal to no off-target activity. UsiRNAs were successfully delivered to bladder or abdominal tumors when encapsulated in DiLA2- or SMARTICLES®-derived liposomes. DiLA2−encapsulated polo-like kinase 1 (PLK1) UsiRNA demonstrated 95% mRNA reduction and up to 70-fold tumor growth inhibition in a bladder cancer orthotopic mouse model and 40-70% mRNA inhibition and ∼80% reduction in tumor-specific bioluminescence in a malignant ascites mouse model following intravesical or intraperitoneal dosing, respectively. In an orthotopic liver tumor animal model, liposomal encapsulated miRNA mimetics provided ∼80% reduction in tumors compared to buffer control. Combinations of formulations and construct capitalize on the advantages of nucleic acid-based therapeutics for precise targeting and flexible delivery to challenging drug targets in cancer and other indications. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 281. doi:1538-7445.AM2012-281

Identification of antigenic epitopes of the SapA protein of Campylobacter fetus using a phage display peptide library

In this study, we immunized mice with prokaryotically expressed recombinant surface layer protein, SapA, of Campylobacter fetus, generated hybridomas secreting mouse monoclonal antibodies (mAb) targeting SapA, and purified the mAb A2D5 from mouse ascites using saturated ammonium sulfate solution. The mAb A2D5, coated onto ELISA plates, was used to screen the phage random 12-peptide library through three rounds of panning. Following panning, 15 phage clones were randomly chosen and tested for reactivity with mAb A2D5 by indirect ELISA. Single-stranded DNA from positive clones was sequenced and compared with the sequence of SapA to predict the key epitope. ELISA and/or Western blot analyses further validated that synthetic peptides and recombinant peptide mimotopes all interact with mAb A2D5. Nine of ten positive phage clones identified by screening were sequenced successfully. Seven clones shared the same sequence HYDRHNYHWWHT; one had the sequence LSKNLPLTALGN; and the final one had the sequence SGMKEPELRSYS. These three sequences shared high homology with SapA J05577 in the region GNEKDFVTKIYSIALGNTSDVDGINYW, in which the underlined amino acids may serve as key residues in the epitope. ELISA and/or Western blot analyses showed that mAb A2D5 not only interacted with the four synthetic peptide mimotopes, but also with 14 prokaryotically expressed recombinant peptide mimotopes. The mimotopes identified in this study will aid future studies into the pathological processes and immune mechanisms of the SapA protein of C. fetus.

Chitinase 3-like 2 Protein Monoclonal Antibodies

Chitinase 3-like 2 (CHI3L2) is one of the most overexpressed genes in glioblastoma. Despite this, both the CHI3L2 gene and its protein product CHI3L2 are poorly characterized. Here we report the generation and characterization of monoclonal antibodies to CHI3L2 protein (CHI3L2 MAbs). Bacterially expressed 6 His-tagged full-length CHI3L2 was used as antigen. Spleen cells from immunized mice were collected and fused with SP2/0 myeloma cells. Hybridoma clones 2D3 and 4D2 producing high titer CHI3L2 MAbs were identified by enzyme-linked immunosorbent assay (ELISA) and further examined for their activity with the CHI3L2 protein by Western blot analysis and immunoprecipitation. The 2D3 clone was chosen for mouse inoculation and ascites formation. Antibodies derived from the ascitic fluid specifically recognized the recombinant CHI3L2 protein and strongly interacted with CHI3L2 in glioblastoma tissue lysate, as determined by Western blot analysis. The antibodies generated may be useful as a tool in various aspects of CHI3L2 investigation.

Preventive effect of ethanol extract of Alpinia calcarata Rosc on Ehrlich's ascitic carcinoma cell induced malignant ascites in mice

Objective To explore cytotoxic activity of ethanol extract of Alpinia calcarata Rosc (EEAC) rhizome against Ehrlich ascites carcinoma (EAC) tumor bearing Swiss Albino mice. Methods In the present study, its anti-neoplastic activity has been studied by monitoring parameters like tumor weight measurement, survival time, tumor cell growth inhibition, haematological characteristics etc. Results It was found that EEAC at dose 8 mg/kg/day ( i.p.) significantly decreased tumor weight (62.0%; P <0.01), increased life span (70.25%; P <0.01) and reduced tumor cell growth rate (85.7%; P <0.01) in comparison to those of EAC bearing mice. The plant extract also improved the depleted haematological parameters like RBC, WBC, Hb%, differential counts ( e.g. lymphocytes, neutrophils, monocytes etc) of EAC bearing mice towards normal. The host toxic effects were not very high and recovered gradually towards normal within a few days after treatment. Conclusions EEAC exhibits potent in vivo cytotoxic activity against EAC tumor bearing Swiss Albino mice. So, the plant can be considered as a probable new source of antitumor agents.

Efficacy of intraperitoneal versus intravenous pemetrexed administration in management of malignant ascites in mice bearing ascitic hepatoma-22

Efficacy of intraperitoneal versus intravenous pemetrexed administration in management of malignant ascites in mice bearing ascitic hepatoma-22

Effect of Lawsonia inermis on tumor expression induced by Dalton’s lymphoma ascites in Swiss albino mice

The purpose of this study was investigating experimentally the possible antitumor effect of ethanol extract of root of Lawsonia inermis against Dalton’s lymphoma ascites (DLA) bearing mice. Mice were administered with L. inermis at a dosage of 180 mg/kg of body weight for 15 days after 24 h of DLA inoculation. The ethanolic root extract of L. inermis reverted the increased number of the WBC count, platelets and lymphocytes and decreased the number of the RBC count, hemoglobin content and monocytes. The effect of root extract of L. inermis also increased the pathophysiological marker enzyme, lipid profile and decreased the enzymic and non enzymic antioxidants. A histopathological result shows the loss of liver hepatocytes and kidney architecture in DLA bearing mice. However, mice treatment with L. inermis extract improves the liver and kidney function and rearranges more or less normal architecture. The present work indicates that the ethanol extract of L. inermis exhibited significant antitumor activity.

Use of Curcumin to Decrease Nitric Oxide Production During the Induction of Antitumor Responses by IL-2

Nitric oxide (NO) synthesis is strongly induced during interleukin (IL)-2 treatment of mice and humans. Although this free radical can act as a cytotoxic effector molecule against cancer cells, immunosuppressive effects have also been suggested. We evaluated the effects of curcumin on IL-2-induced NO synthesis and IL-2-induced antitumor responses in a mouse ascites tumor model. Curcumin inhibited inducible nitric oxide synthase (iNOS) expression and NO production, and thereby enhanced the proliferation and cytotoxic activity of cocultured lymphocytes and macrophages during IL-2 stimulation which we earlier established as an in vitro model of IL-2-induced NO synthesis. Curcumin also decreased apoptosis of cocultured lymphocytes and macrophages during IL-2 stimulation. In contrast, the curcumin-induced changes in proliferation and apoptosis were not observed in cultures of lymphocytes alone, macrophages alone, and cocultured lymphocytes/iNOS-knock out macrophages, all of which produced little nitrite during IL-2 stimulation. In conjunction with IL-2 treatment, oral curcumin administration significantly inhibited IL-2 therapy-induced urinary nitrite/nitrate excretion and iNOS expression of tumor tissues, and further increased the IL-2 therapy-induced prolongation of survival in a murine Meth-A ascites tumor model. Curcumin may be useful as an adjunct to increase the antitumor activity of IL-2 therapy.

Hollow spheroids in ascites of ovarian clear cell carcinoma: how are they formed and how do they behave?

Although the multicellular aggregates (spheroids) in malignant ascites are usually solid throughout, they sometimes have acellular hollow spaces, especially in ascites of ovarian clear cell carcinoma. The purpose of this study is to analyse the origin and behaviour of hollow spheroids. Archival cytological and histological specimens of 32 ovarian carcinomas, including 12 clear cell carcinomas, were reviewed. HAC-2, a clear cell carcinoma cell line, was injected into the abdominal cavity of nude mice for direct comparison of ascitic cytology and tumour histology. Spheroids that were collected from nude mice ascites were cultured in vitro to observe their behaviour. Five of six clear cell carcinomas with hollow spheroids showed spherule-like hyaluronan-rich stroma in their tumour tissue, whereas those without hollow spheroids did not. After heterotransplantation, both ascites and tumour imprints showed small or large hollow spheroids. Hyaluronan was detected in the former but not in the latter. The abdominal tumours showed compact spherule-like hyaluronan-rich stroma, enlarged oedematous stroma or intermediate stroma. In both size and hyaluronan status, small and large hollow spheroids were approximately comparable to spherule-like hyaluronan-rich stroma and oedematous stroma, respectively. During culture in vitro, hollow spheroids were maintained as hollow spheroids in suspension, and produced daughter hollow spheroids. The hollow space in the spheroids originates from spherule-like hyaluronan-rich stroma, where water trapping by hyaluronan causes enlargement of the space. The matrix within the hollow space serves as a scaffold that regulates cell polarity and matrix production.

Chemotherapy with hybrid liposomes for acute lymphatic leukemia leading to apoptosis in vivo

Hybrid liposomes (HL) composed of 95 mol% l-α-dimyristoylphosphatidylcholine (DMPC) and 5 mol% polyoxyethylene (25) dodecyl ether (C 12(EO) 25) were prepared by sonication. A clear solutions of HL-25 having hydrodynamic diameter of about 50 nm could be maintained over 3 weeks. Remarkable reduction of tumor volume in model mice of acute lymphatic leukemia (ALL) intravenously treated with HL-25 without drugs after the subcutaneously inoculation of human ALL (MOLT-4) cells was verified in vivo. Induction of apoptosis in tumor of model mice of ALL treated with HL-25 was observed in micrographs on the basis of TUNEL method. Remarkable decrease of the ascites in ALL model mice treated with HL-25 was observed. It is noteworthy that prolonged survival (>400%) was obtained in model mice of ALL after the treatment with HL-25 without drugs.

Resurrection of a clinical antibody: Template proteogenomic de novo proteomic sequencing and reverse engineering of an anti‐lymphotoxin‐α antibody

A mouse hybridoma antibody directed against a member of the tumour necrosis factor (TNF)-superfamily, lymphotoxin-alpha (LT-α), was isolated from stored mouse ascites and purified to homogeneity. After more than a decade of storage the genetic material was not available for cloning; however, biochemical assays with the ascites showed this antibody against LT-α (LT-3F12) to be a preclinical candidate for the treatment of several inflammatory pathologies. We have successfully rescued the LT-3F12 antibody by performing MS analysis, primary amino acid sequence determination by template proteogenomics, and synthesis of the corresponding recombinant DNA by reverse engineering. The resurrected antibody was expressed, purified and shown to demonstrate the desired specificity and binding properties in a panel of immuno-biochemical tests. The work described herein demonstrates the powerful combination of high-throughput informatic proteomic de novo sequencing with reverse engineering to reestablish monoclonal antibody-expressing cells from archived protein sample, exemplifying the development of novel therapeutics from cryptic protein sources.

Topotecan as a molecular targeting agent which blocks the Akt and VEGF cascade in platinum-resistant ovarian cancers

(Objective) Topotecan, a novel topoisomerase-1 inhibitor, is a drug that appears to be effective against platinum-resistant ovarian cancers. However, the molecular mechanisms by which Topotecan treatment inhibits cancer cell proliferation are unclear. We investigated whether Topotecan increases the efficacy of Cisplatin in platinum-resistant ovarian cancer models in vitro and in vivo. (Methods) We used Cisplatin-resistant Caov-3 cells and Cisplatin-sensitive A2780 cells. We examined the effect of Cisplatin and Topotecan on the cell viability of Caov-3 and A2780 cells by MTS assay. We examined the Akt kinase activity, VEGF and HIF-1α expression after Cisplatin and Topotecan by a Western blot analysis. Moreover, we also evaluated the effects of Cisplatin and Topotecan on the intraabdominal dissemination of ovarian cancer in vivo. (Results) Topotecan significantly inhibited Cisplatin-induced Akt activation in Caov-3 cells, but not in A2780 cells. In the presence of Topotecan, Cisplatin-induced growth inhibition and apoptosis were significantly enhanced in Caov-3 cells. Topotecan inhibited not only Cisplatin-induced Akt activation but also VEGF and HIF-1α expression. Moreover, treatment with Topotecan increased the efficacy of Cisplatin-induced growth inhibition in the intraabdominal dissemination and production of ascites in athymic nude mice inoculated with Caov-3 cells. (Conclusion) We herein demonstrated that Topotecan inhibits Akt kinase activity and VEGF transcriptional activation after Cisplatin treatment in platinum-resistant ovarian cancers. We clarified how Topotecan enhanced the clinical activity in the platinum-resistant ovarian cancer. These results provide a rationale for using Topotecan in clinical regimens aimed at molecular targeting agents in platinum-resistant ovarian cancers.

Contamination with recombinant IFN accounts for the unexpected stimulatory properties of commonly used IFN‐blocking antibodies

Contamination with recombinant IFN accounts for the unexpected stimulatory properties of commonly used IFN‐blocking antibodies

왕겨에 의한 신령버섯균사체 액체배양액의 생쥐 항복수암성 증가

The effects of rice hull (RH) powder on the anticarcinogenic activity of submerged-liquid cultures of Agaricus blazei Murill (AB) were assessed for mouse ascites cancers induced by mouse Sarcoma S-180 (S-180) cancer cells. Optimal growth of AB mycelia in the basal liquid culture medium, containing soybean meal, was achieved by culturing at for 5 days, when evaluated by -glucan content, Brix, and mycelial weight, relative to other culture conditions. Hot-water extract (HWE) of the submergedliquid culture of AB mycelia grown at for 5 days exhibited a stronger anticarcinogenic activity, relative to HWE from other culture conditions. No such effects were obtained from AB mycelial cultures by alternative temperature-controlling cultures. Both cytotoxicity for S-180 cells and anticarcinogenic potentials for mouse ascites cancer of the HWE from AB mycelia grown in the basal medium containing 1% RH powder for 5 days at were significantly (p for 5 days, enhanced anticarcinogenic activity against S-180 cell-induced mouse ascites cancer, and suggest that RH powder is an excellent ingredient for the improvement of the anticarcinogenic potentials of the submerged-liquid culture of mushroom mycelia.

Antigen-Specific Immunity and Cross-Priming by Epithelial Ovarian Carcinoma-Induced CD11b+Gr-1+ Cells

Both innate and adaptive immune systems are considered important for cancer prevention, immunosurveillance, and control of cancer progression. It is known that, although both systems initially eliminate emerging tumor cells efficiently, tumors eventually escape immune attack by a variety of mechanisms, including differentiation and recruitment of immunosuppressive CD11b(+)Gr-1(+) myeloid suppressor cells into the tumor microenvironment. However, we show that CD11b(+)Gr-1(+) cells found in ascites of epithelial ovarian cancer-bearing mice at advanced stages of disease are immunostimulatory rather than being immunosuppressive. These cells consist of a homogenous population of cells that morphologically resemble neutrophils. Moreover, like dendritic cells, immunostimulatory CD11b(+)Gr-1(+) cells can strongly cross-prime, augmenting the proliferation of functional CTLs via signaling through the expression of costimulatory molecule CD80. Adoptive transfer of these immunostimulatory CD11b(+)Gr-1(+) cells from ascites of ovarian cancer-bearing mice results in the significant regression of s.c. tumors even without being pulsed with exogenous tumor Ag prior to adoptive transfer. We now show for the first time that adaptive immune responses against cancer can be augmented by these cancer-induced granulocyte-like immunostimulatory myeloid (CD11b(+)Gr-1(+)) cells, thereby mediating highly effective antitumor immunity in an adoptive transfer model of immunity.

Effect of a topoisomerase-1 inhibitor (topotecan) on the efficacy of cisplatin in in vitro and in vivo platinum-resistant ovarian cancer models.

e13160 Background: Topotecan, a novel topoisomerase-1 inhibitor, is one of the drugs that might be effective against platinum-resistant epithelial ovarian cancer. However, the molecular mechanisms by which topotecan treatment inhibits cancer cell proliferation are unclear. The PI3K/Akt cascade is known to be an important survival factor in the signal transduction cascades involved in the cell growth. We investigated whether topotecan increases the efficacy of cisplatin in in vitro and in vivo ovarian cancer models. Methods: Mice: BALB/c Slc-nu/nu. Caov-3 cells: The cells are cisplatin-resistant human-derived ovarian cancer cell (mucinous adenocarcinoma). 5×106 Caov-3 cells were injected i.p. into 6-week-old female athymic nude mice (n=20). Athymic nude mice were injected i.p.with Caov-3 cells. Two weeks after inoculation, athymic nude mice inoculated i.p. with Caov-3 cells were randomized into four groups treated with the following for 6 weeks: (a) vehicle (PBS) alone; (b) CDDP (cisplatin 5 mg/kg) once a week; (c) TPT (topotecan 12.5 mg/kg) once a week; (d) CDDP + TPT (cisplatin 5mg/kg + topotecan 12.5 mg/kg) once a week. Results: Topotecan significantly inhibited the cisplatin-induced Akt activation in Caov-3 cells, but not in A2780 cells. In the presence of topotecan, cisplatin-induced inhibition and apoptosis was significantly enhanced in Caov-3 cells. Moreover, treatment with topotecan increased the efficacy of the cisplatin-induced inhibition in the intraabdominal dissemination and production of ascites in athymic nude mice inoculated i.p. with Caov-3 cells. Topotecan inhibited not only the cisplatin-induced Akt activity but also VEGF transcriptional activation and HIF-1a expression which was induced by cisplatin. Conclusions: These results suggest that combination therapy by cisplatin and topotecan would increase the therapeutic efficacy of the platinum-resistant epithelial ovarian cancer. No significant financial relationships to disclose.

Peroxisome Proliferator-Activated Receptor (PPAR)γ Can Inhibit Chronic Renal Allograft Damage

Chronic inflammation and fibrosis are the leading causes of chronic allograft failure. The nuclear receptor peroxisome proliferator-activated receptor (PPAR)gamma is a transcription factor known to have antidiabetogenic and immune effects, and PPARgamma forms obligate heterodimers with the retinoid X receptor (RXR). We have reported that a retinoic acid (RAR)/RXR-agonist can potently influence the course of renal chronic allograft dysfunction. In this study, in a Fischer to Lewis rat renal transplantation model, administration of the PPARgamma-agonist, rosiglitazone, independent of dose (3 or 30 mg/kgBW/day), lowered serum creatinine, albuminuria, and chronic allograft damage with a chronic vascular damage score as follows: 35.0 +/- 5.8 (controls) vs. 8.1 +/- 2.4 (low dose-Rosi; P < 0.05); chronic tubulointerstitial damage score: 13.6 +/- 1.8 (controls) vs. 2.6 +/- 0.4 (low dose-Rosi; P < 0.01). The deposition of extracellular matrix proteins (collagen, fibronectin, decorin) was strikingly lower. The expression of transforming growth factor-beta1 was inhibited, whereas that of bone morphogenic protein-7 (BMP-7) was increased. Intragraft mononuclear cells and activated fibroblast numbers were reduced by 50%. In addition, the migratory and proliferative activity of these cells was significantly inhibited in vitro. PPARgamma activation diminished the number of cells expressing the proinflammatory and fibrogenic proteoglycan biglycan. In macrophages its secretion was blocked by rosiglitazone in a predominantly PPARgamma-dependent manner. The combination of PPARgamma- and RAR/RXR-agonists resulted in additive effects in the inhibition of fibrosis. In summary, PPARgamma activation was potently immunosuppressive and antifibrotic in kidney allografts, and these effects were enhanced by a RAR/RXR-agonist.