Effect of PEDF on the in vivo antitumor activities of low-dose chemotherapy in CRPC.

2013 ◽  
Vol 31 (6_suppl) ◽  
pp. 173-173
Author(s):  
Thomas Nelius ◽  
Everardo Cobos ◽  
Jennifer Hirsch ◽  
Stephanie Filleur
Keyword(s):  
Prostate Cancer ◽  
Low Dose ◽  
Pigment Epithelium ◽  
Growth Curves ◽  
Great Promise ◽  
Tumor Bearing ◽  
Cytotoxicity Effects ◽  
Low Dose Chemotherapy

173 Background: The development of metronomic/low dose administration of conventional chemotherapeutic drugs has shown great promise in the treatment of castration-refractory prostate cancer (CPRC). Pigment Epithelium-Derived Factor (PEDF) is a natural angio-inhibitor which is down-regulated in prostate cancer. We have previously demonstrated that the over-expression of PEDF in human CRPC PC3 cells decreased tumor growth in vivo. In the present study, we further validated PEDF anti-tumor properties in the highly metastatic CRPC LNCaP-derivative CL1 cells. We also hypothesized that PEDF may enhance the cytotoxicity effects of low dose docetaxel (DTX) and cyclophosphamide (CTX) chemotherapies in vivo. Methods: PC3 and CL1 cell lines were genetically modified to stably express the fluorescent DsRed Express protein with PEDF. Resulting cells were characterized in vitro for PEDF expression by western blot and, for proliferation by growth curves and clone formation in matrigel. PEDF anti-tumor effects were assessed on established s.c. xenografts in mice treated with DTX (5mg/kg ip every 4 days, 1mg/kg ip daily for 10 days, 0.5mg/kg every other day), CTX (10-20mg/kg in the drinking water) or placebo. Survival studies were performed by injecting CL1-PEDF or -control cells into the left lobe of the dorsal prostate of anesthetized mice. Results: We showed that PEDF expression inhibits the proliferation and induces the differentiation of CPRC cells in vitro, and decreases by 85% and 70% the development of s.c. PC3 and CL1 tumors, respectively. In the survival study, PEDF expression prolongs significantly (P=0.01; 95% confidence interval) the median survival of CL1 tumor-bearing mice (53±0.001 days versus 57±1). Furthermore, we demonstrated that PEDF enhances the cytotoxicity effects of low dose chemotherapy on established s.c. tumors (best Doc dose: 1mg/kg for PC3 and 5mg/kg for CL1; best CTX dose: 10mg/kg for PC3 and CL1) and prolongs significantly the survival of tumor-bearing mice undergoing low dose chemotherapy. Conclusions: These data reinforce the significance of PEDF as a potent target for the treatment of CRPC. It also emphasizes PEDF as a promising new agent to enhance the anti-tumor efficacy of low dose chemotherapies.

Effect of PEDF on survival and the in vivo antitumor activities of low-dose chemotherapy in castration-refractory prostate cancer.

2012 ◽  
Vol 30 (5_suppl) ◽  
pp. 237-237
Author(s):  
Thomas Nelius ◽  
Natalie Pardue ◽  
Jessica Gillen ◽  
Katherine Rinard ◽  
Jennifer Hirsch ◽  
...  
Keyword(s):  
Prostate Cancer ◽  
Low Dose ◽  
Pigment Epithelium ◽  
Growth Curves ◽  
Left Lobe ◽  
Great Promise ◽  
Cytotoxicity Effects ◽  
Low Dose Chemotherapy

237 Background: The development of metronomic/low dose of conventional chemotherapeutic drugs have recently showed great promise in the treatment of castration-refractory prostate cancer (CPRC). Pigment Epithelium-Derived Factor (PEDF) is a natural angio-inhibitor which is down-regulated in prostate cancer. We have previously demonstrated that the over-expression of PEDF in human CRPC PC3 cells decreased tumor growth in vivo. In the present study, we further validated PEDF anti-tumor properties in the highly metastatic CRPC LNCaP-derivative CL1 cells. We also hypothesized that PEDF may enhance the cytotoxicity effects of low dose docetaxel (Doc) and cyclophosphamide (CTX) chemotherapies in vivo. Methods: Human PC3 and CL1 cell lines were genetically modified to stably express the fluorescent DsRed Express protein with PEDF. Resulting cells were characterized in vitro for PEDF expression by western blot and, for proliferation by growth curves and clone formation in matrigel. PEDF anti-tumor effects were assessed on established s.c. xenografts in mice treated with Doc (5mg/kg ip every 4 dy, 1mg/kg ip daily for 10 days, 0.5mg/kg every other day), CTX (10-20mg/kg in the drinking water) or placebo. Survival studies were performed by injecting CL1 cells with 50nM hrPEDF or carrier control into the left lobe of the dorsal prostate of anesthetized mice. Results: We showed that PEDF inhibits the proliferation and induces the differentiation of all CPRC cells tested in vitro. Similarly, PEDF expression decreases by 85% and 70% the development of s.c. PC3 and CL1 tumors, respectively. In the survival study, we found that all control animals die within 61 days after surgery while 50% of PEDF-pretreated animals were still alive. Most importantly, we demonstrated that PEDF enhances the cytotoxicity effects of low dose chemotherapy on established tumors (best Doc dose: 1mg/kg for PC3 and 5mg/kg for CL1; best CTX dose: 10mg/kg for PC3 and CL1). Conclusions: These data reinforce the significance of PEDF as a potential new target for the treatment of advanced prostate cancer. It also emphasizes PEDF as a promising new agent to enhance the anti-tumor efficacy of low dose Doc and CTX chemotherapies.

Effect of PEDF on survival and in vivo antitumor activities of low-dose chemotherapy in castration-refractory prostate cancer.

2012 ◽  
Vol 30 (15_suppl) ◽  
pp. e15103-e15103
Author(s):  
Natalie Gaines ◽  
Thomas Nelius ◽  
Jessica Gillen ◽  
Katherine Rinard ◽  
Jose Lopez ◽  
...  
Keyword(s):  
Prostate Cancer ◽  
Low Dose ◽  
Pigment Epithelium ◽  
Growth Curves ◽  
Left Lobe ◽  
Cytotoxic Effects ◽  
Survival Studies ◽  
Low Dose Chemotherapy

e15103 Background: The development of metronomic/low-dose treatment with conventional chemotherapeutic drugs has recently shown promise in the treatment of castration-refractory prostate cancer (CPRC). Pigment Epithelium-Derived Factor (PEDF) is a natural angio-inhibitor which is downregulated in prostate cancer. Previously we demonstrated that overexpression of PEDF in human CRPC PC3 cells decreased tumor growth in vivo. In the present study, we further validate PEDF anti-tumor properties in highly metastatic CRPC LNCaP-derivative CL1 cells. We also hypothesized that PEDF may enhance the cytotoxic effects of low-dose docetaxel (Doc) and cyclophosphamide (CTX) chemotherapies in vivo. Methods: Human PC3 and CL1 cell lines were genetically modified to stably express fluorescent DsRed Express protein with PEDF. Resulting cells were characterized in vitro for PEDF expression by western blot and for proliferation by growth curves and clone formation in Matrigel. PEDF anti-tumor effects were assessed on established SC xenografts in mice treated with Doc (5mg/kg IP every 4 days, 1mg/kg IP daily for 10 days, 0.5mg/kg IP every other day), CTX (10-20mg/kg in drinking water) or placebo. Survival studies were performed by injecting CL1 cells that express PEDF or control into the left lobe of the dorsal prostate of anesthetized mice. Results: We showed that PEDF inhibits proliferation and induces differentiation of all CPRC cells tested in vitro. Similarly, PEDF expression decreases by 85% and 70% the development of SC PC3 and CL1 tumors, respectively. In the survival study, we found that PEDF expression prolongs significantly (p=0.01; 95% confidence interval) median survival of CL1 tumor-bearing mice (53±0.001 days versus 57±1). Most importantly, we demonstrated that PEDF enhances the cytotoxic effects of low-dose chemotherapy on established tumors (best Doc dose: 1mg/kg for PC3 and 5mg/kg for CL1; best CTX dose: 10mg/kg for PC3 and CL1). Conclusions: This data reinforces the significance of PEDF as a potential new target when treating advanced prostate cancer. It also emphasizes PEDF as a promising new agent to enhance the anti-tumor efficacy of low-dose Doc and CTX chemotherapies.

Comparison of docetaxel and cabazitaxel efficacy on prostate cancer cells both in vitro and in vivo.

2016 ◽  
Vol 34 (2_suppl) ◽  
pp. 351-351 ◽  
Author(s):  
Thomas Nelius ◽  
Courtney Jarvis ◽  
Dalia Martinez-Marin ◽  
Stephanie Filleur
Keyword(s):  
Prostate Cancer ◽  
Therapeutic Strategy ◽  
Low Dose ◽  
Pigment Epithelium ◽  
Annexin V ◽  
Cell Cycle Distribution ◽  
Standard Regimen ◽  
Du145 Cells

351 Background: Despite recently approved novel agents, taxane-based chemotherapy remains the major therapeutic strategy for metastatic castration-refractory prostate cancer/mCRPC. Still mCRPC continues to be incurable. Besides, patients often experience severe side effects, prompting a re-evaluation of standard regimen. Past studies have demonstrated promise for Low-Dose Metronomic/LDM chemotherapy, defined as the frequent administration of low doses of chemotherapeutic drugs with no prolonged drug-free breaks. Yet relative activities of LDM taxanes and combinations with known anti-neoplasic agents have to be investigated. Methods: PC3, Du145 and LNCaP-derivative CL1cell lines were used to compare the effect of increasing doses of taxanes on cell proliferation, cell cycle distribution and apoptosis by crystal violet, propidium iodide and AnnexinV stainings, respectively. Autophagy was assessed by western blotting against Beclin1. In vivotumor growth was measured using CL1 control and CL1-PEDF xenografts. Phagocytosis was determined by cytotoxicity assay in CL1-macrophages co-cultures. Results: Our data showed that cabazitaxel/cbz-treated cells had a significantly lower EC50 compared to docetaxel/doc, with Du145 cells presenting the greatest differences. Both low-dose taxanes increased the sub-G0 cells population. However, the sub-G0 increase was significantly greater in cbz- than doc-treated Du145 cells, but not in PC3 and CL1. Accordingly, plasma membrane Annexin V elevation occurred in Du145 cells at lower doses of cbz than doc validating a higher efficacy due to increased apoptosis. Although Beclin1 levels remain unchanged in PC3 and CL1 cells, it was found up-regulated for all doses of cbz in Du145. In vivo, LDM cbz was significantly more efficient in curbing tumor growth than doc. This effect was markedly increased when cbz was combined with the angio-inhibitor and anti-tumor Pigment Epithelium-Derived Factor (PEDF); an effect that could be explained by increased phagocytosis. Conclusions: Our data demonstrate a higher efficacy of cbz on CRPC both in vitro and in vivo, and suggest that LDM taxane chemotherapy/PEDF combination could be used as a novel therapeutic strategy for CRPC.

scholarly journals Targeting human leukocyte antigen G with chimeric antigen receptors of natural killer cells convert immunosuppression to ablate solid tumors

2021 ◽  
Vol 9 (10) ◽  
pp. e003050
Author(s):  
Chia-Ing Jan ◽  
Shi-Wei Huang ◽  
Peter Canoll ◽  
Jeffrey N Bruce ◽  
Yu-Chuan Lin ◽  
...  
Keyword(s):  
Human Leukocyte Antigen ◽  
Natural Killer ◽  
Solid Tumors ◽  
Low Dose ◽  
Human Leukocyte ◽  
Leukocyte Antigen ◽  
Low Dose Chemotherapy ◽  
Human Leukocyte Antigen G

BackgroundImmunotherapy against solid tumors has long been hampered by the development of immunosuppressive tumor microenvironment, and the lack of a specific tumor-associated antigen that could be targeted in different kinds of solid tumors. Human leukocyte antigen G (HLA-G) is an immune checkpoint protein (ICP) that is neoexpressed in most tumor cells as a way to evade immune attack and has been recently demonstrated as a useful target for chimeric antigen receptor (CAR)-T therapy of leukemia by in vitro studies. Here, we design and test for targeting HLA-G in solid tumors using a CAR strategy.MethodsWe developed a novel CAR strategy using natural killer (NK) cell as effector cells, featuring enhanced cytolytic effect via DAP12-based intracellular signal amplification. A single-chain variable fragment (scFv) against HLA-G is designed as the targeting moiety, and the construct is tested both in vitro and in vivo on four different solid tumor models. We also evaluated the synergy of this anti-HLA-G CAR-NK strategy with low-dose chemotherapy as combination therapy.ResultsHLA-G CAR-transduced NK cells present effective cytolysis of breast, brain, pancreatic, and ovarian cancer cells in vitro, as well as reduced xenograft tumor growth with extended median survival in orthotopic mouse models. In tumor coculture assays, the anti-HLA-G scFv moiety promotes Syk/Zap70 activation of NK cells, suggesting reversal of the HLA-G-mediated immunosuppression and hence restoration of native NK cytolytic functions. Tumor expression of HLA-G can be further induced using low-dose chemotherapy, which when combined with anti-HLA-G CAR-NK results in extensive tumor ablation both in vitro and in vivo. This upregulation of tumor HLA-G involves inhibition of DNMT1 and demethylation of transporter associated with antigen processing 1 promoter.ConclusionsOur novel CAR-NK strategy exploits the dual nature of HLA-G as both a tumor-associated neoantigen and an ICP to counteract tumor spread. Further ablation of tumors can be boosted when combined with administration of chemotherapeutic agents in clinical use. The readiness of this novel strategy envisions a wide applicability in treating solid tumors.

scholarly journals Long Non-Coding RNA MEG3 Inhibits Cell Proliferation and Induces Apoptosis in Prostate Cancer

2015 ◽  
Vol 37 (6) ◽  
pp. 2209-2220 ◽  
Author(s):  
Gang Luo ◽  
Miao Wang ◽  
Xinchao Wu ◽  
Dan Tao ◽  
Xinyuan Xiao ◽  
...  
Keyword(s):  
Prostate Cancer ◽  
Cell Cycle ◽  
Cancer Progression ◽  
Regulatory Protein ◽  
Growth Curves ◽  
Underlying Mechanism ◽  
Tumor Tissues ◽  
Cancer Tissues

Background/Aims: Long non-coding RNAs (lncRNAs) play important roles in diverse biological processes, such as cell growth, apoptosis and migration. Although downregulation of lncRNA maternally expressed gene 3 (MEG3) has been identified in several cancers, little is known about its role in prostate cancer progression. The aim of this study was to detect MEG3 expression in clinical prostate cancer tissues, investigate its biological functions in the development of prostate cancer and the underlying mechanism. Methods: MEG3 expression levels were detected by qRT-PCR in both tumor tissues and adjacent non-tumor tissues from 21 prostate cancer patients. The effects of MEG3 on PC3 and DU145 cells were assessed by MTT assay, colony formation assay, western blot and flow cytometry. Transfected PC3 cells were transplanted into nude mice, and the tumor growth curves were determined. Results: MEG3 decreased significantly in prostate cancer tissues relative to adjacent normal tissues. MEG3 inhibited intrinsic cell survival pathway in vitro and in vivo by reducing the protein expression of Bcl-2, enhancing Bax and activating caspase 3. We further demonstrated that MEG3 inhibited the expression of cell cycle regulatory protein Cyclin D1 and induced cell cycle arrest in G0/G1 phase. Conclusions: Our study presents an important role of MEG3 in the molecular etiology of prostate cancer and implicates the potential application of MEG3 in prostate cancer therapy.

scholarly journals Promotion of tumor progression induced by continuous low-dose administration of antineoplastic agent gemcitabine or gemcitabine combined with cisplatin

2021 ◽  
Author(s):  
Yanshen CHEN ◽  
Hua LIU ◽  
Qiaowei ZHENG ◽  
Houli LI ◽  
Huining YOU ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Tumor Cells ◽  
Antineoplastic Agents ◽  
Low Dose ◽  
Tumor Formation ◽  
Dose Administration ◽  
Tumor Tissues ◽  
Low Dose Chemotherapy

Abstract Background: There are indications that certain antineoplastic agents at low dosages may exhibit abnormal pharmacological actions, such as promoting tumor growth. However, the phenomenon still needs to be further confirmed, and its underlying mechanisms have not yet been fully elucidated.Methods: Gemcitabine (GEM) and cisplatin (CDDP) were employed as representative antineoplastic agents to observe effects of continuous low-dose chemotherapy with GEM or GEM combined with CDDP (GEM+CDDP) on tumor formation and growthin xenograft tumor models in vivo. Tumor and endothelial cell functions, apoptosis, cell cycle analysis, as well as bone marrow derived cells (BMDCs) mobilization, were evaluated with transwell, MTT or flow cytometry analysis in vitro, respectively. Histological methods were employed to assess angiogenesis in tumor tissues.Results: The results showed that tumor formation and growth were both significantly promoted by GEM or GEM+CDDP at as low as half of the metronomic dosages, which were accompanied by enhancements of angiogenesis in tumor tissues and the release of proangiogenic BMDCs in the circulating blood. Additionally, GEM or GEM+CDDP at low concentrations dramatically facilitated the proliferation, migration, and invasion of tumor cells in vitro. Cell-cycle arrest, activation of associated apoptotic proteins, and inhibition of apoptosis were also observed in tumor cells. Conclusions: These findings indicate that, the continuous low-dose administration of GEM and GEM+CDDP can promote tumorigenesis and tumor progression in vivo by inhibiting apoptosis, mobilizing BMDCs, and promoting angiogenesis in certain dose ranges. These findings urge further investigations to avoid the potential risks in current empiric continuous low-dose chemotherapy regimens with antineoplastic agents.

scholarly journals Development of EphA2 siRNA-loaded lipid nanoparticles and combination with a small-molecule histone demethylase inhibitor in prostate cancer cells and tumor spheroids

2020 ◽  
Author(s):  
Ezgi Oner ◽  
Mustafa Kotmakci ◽  
Anne-Marie Baird ◽  
Steven G. Gray ◽  
Bilge Debelec Butuner ◽  
...  
Keyword(s):  
Prostate Cancer ◽  
Cellular Uptake ◽  
Transfection Efficiency ◽  
Cationic Lipid ◽  
Lipid Nanoparticles ◽  
In Vivo Studies ◽  
Great Promise ◽  
Tumor Spheroids

Abstract Background: siRNAs hold a great potential for cancer therapy, however, poor stability in body fluids and low cellular uptake limit their use in the clinic. To enhance the bioavailability of siRNAs in tumors, novel, safe, and effective carriers are needed. Results: Here, we developed cationic solid lipid nanoparticles (cSLNs) to carry siRNAs targeting EphA2 receptor tyrosine kinase (siEphA2), which is overexpressed in many solid tumors including prostate cancer (PCa). Using DDAB cationic lipid instead of DOTMA reduced nanoparticle size and enhanced both cellular uptake and gene silencing in PCa cells. DDAB-cSLN showed better cellular uptake efficiency with similar silencing compared to commercial transfection reagent Dharmafect-2. After verifying the efficacy of siEphA2-loaded nanoparticles, we further evaluated a potential combination with a histone lysine demethylase inhibitor, JIB-04. Silencing EphA2 by siEphA2-loaded DDAB-cSLN did not affect the viability (2D and 3D), migration, and clonogenicity of PC-3 cells alone. However, upon co-administration, there was a decrease in the aforementioned cellular responses due to JIB-04. Furthermore, JIB-04 decreased EphA2 expression, and thus, silencing efficiency of siEphA2-loaded nanoparticles was further increased with co-treatment. Conclusions: We have successfully developed a novel siRNA-loaded lipid nanoparticle for targeting EphA2. Moreover, detailed preliminary results of the effects of JIB-04, alone and in combination with siEphA2, on PCa cells and tumor spheroids were presented for the first time. Our delivery system provides high transfection efficiency and shows a great promise for targeting other genes and cancer types in further in vitro and in vivo studies.

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