RESUMO
A major challenge in photothermal treatment is generating sufficient heat to eradicate diseased tissue while sparing normal tissue. Au nanomaterials have shown promise as a means to achieve highly localized photothermal treatment. Toward that end, the synthetic peptide anginex was conjugated to Au nanocages. Anginex binds to galectin-1, which is highly expressed in dividing endothelial cells found primarily in the tumor vasculature. The skin surface temperature during a 10 min laser exposure of subcutaneous murine breast tumors did not exceed 43°C and no normal tissue damage was observed, yet a significant anti-tumor effect was observed when laser was applied 24 h post-injection of targeted nanocages. Untargeted particles showed little effect in immunocompetent, tumor-bearing mice under these conditions. Photoacoustic, photothermal, and ICP-MS mapping of harvested tissue showed distribution of particles near the vasculature throughout the tumor. This uptake pattern within the tumor combined with a minimal overall temperature rise were nonetheless sufficient to induce marked photothermal efficacy and evidence of tumor control. Importantly, this evidence suggests that bulk tumor temperature during treatment does not correlate with treatment outcome, which implies that targeted nanomedicine can be highly effective when closely bound/distributed in and around the tumor endothelium and extensive amounts of direct tumor cell binding may not be a prerequisite of effective photothermal approaches.
Assuntos
Sistemas de Liberação de Medicamentos , Ouro , Hipertermia Induzida , Nanopartículas Metálicas , Neoplasias Experimentais , Fototerapia , Animais , Linhagem Celular Tumoral , Feminino , Ouro/química , Ouro/farmacologia , Nanopartículas Metálicas/química , Nanopartículas Metálicas/uso terapêutico , Camundongos , Camundongos Endogâmicos BALB C , Neoplasias Experimentais/irrigação sanguínea , Neoplasias Experimentais/metabolismo , Neoplasias Experimentais/patologia , Neoplasias Experimentais/terapiaRESUMO
Angiogenesis plays a critical role in progression of malignant gliomas. The development of glioma-specific labeling molecules that can aid detection and visualization of angiogenesis can help surgical planning and improve treatment outcome. The aim of this study was to evaluate if two peptides (GX1 and RGD-GX1) linked to angiogenesis can be used as an MR-imaging markers of angiogenesis. MR imaging was performed in U87 glioblastoma-bearing NOD-SCID mice at different time points between 15 and 120 min post-injection to visualize particle distribution. GX1 and RGD-GX1 exhibited the highest accumulation in U87 glioblastoma at 120 min post i.v. administration. GX1-conjugated agents lead to higher decrease in transverse relaxation time (T 2) (i.e., stronger contrast enhancement) than RGD-GX1-conjugated agents in U87 glioblastoma tumor model. In addition, we tested if U87-IDH1R132 mutated cell line had different pattern of GX1 or RGD-GX1 particle accumulation. Responses in U87-IDH1WT followed a similar pattern with GX1 contrast agents; however, lower contrast enhancement was observed with RGD-GX1 agents. The specific binding of these peptides to human glioblastoma xenograft in the brain was confirmed by magnetic resonance imaging. The contrast enhancement following injection of magnetonanoparticles conjugated to GX1 peptide matched well with CD31 staining and iron staining.
Assuntos
Neoplasias Encefálicas , Meios de Contraste , Glioma , Imageamento por Ressonância Magnética , Nanopartículas de Magnetita , Neoplasias Experimentais , Neovascularização Patológica , Oligopeptídeos , Animais , Neoplasias Encefálicas/irrigação sanguínea , Neoplasias Encefálicas/diagnóstico por imagem , Neoplasias Encefálicas/metabolismo , Linhagem Celular Tumoral , Meios de Contraste/química , Meios de Contraste/farmacologia , Glioma/irrigação sanguínea , Glioma/diagnóstico por imagem , Glioma/metabolismo , Humanos , Nanopartículas de Magnetita/química , Nanopartículas de Magnetita/uso terapêutico , Masculino , Camundongos , Camundongos Endogâmicos NOD , Camundongos SCID , Neoplasias Experimentais/irrigação sanguínea , Neoplasias Experimentais/diagnóstico por imagem , Neoplasias Experimentais/metabolismo , Neovascularização Patológica/diagnóstico por imagem , Neovascularização Patológica/metabolismo , Oligopeptídeos/química , Oligopeptídeos/farmacologiaRESUMO
The LX-2 cell line has characteristics of hepatic stellate cells (HSCs), which are considered pericytes of the hepatic microcirculatory system. Recent studies have suggested that HSCs might have mesenchymal origin. We have performed an extensive characterization of the LX-2 cells and have compared their features with those of mesenchymal cells. Our data show that LX-2 cells have a phenotype resembling activated HSCs as well as bone marrow-derived mesenchymal stem cells (BM-MSCs). Our immunophenotypic analysis showed that LX-2 cells are positive for activated HSC markers (αSMA, GFAP, nestin and CD271) and classical mesenchymal makers (CD105, CD44, CD29, CD13, CD90, HLA class-I, CD73, CD49e, CD166 and CD146) but negative for the endothelial marker CD31 and endothelial progenitor cell marker CD133 as well as hematopoietic markers (CD45 and CD34). LX-2 cells also express the same transcripts found in immortalized and primary BM-MSCs (vimentin, annexin 5, collagen 1A, NG2 and CD140b), although at different levels. We show that LX-2 cells are capable to differentiate into multilineage mesenchymal cells in vitro and can stimulate new blood vessel formation in vivo. LX-2 cells appear not to possess tumorigenic potential. Thus, the LX-2 cell line behaves as a multipotent cell line with similarity to BM-MSCs. This line should be useful for further studies to elucidate liver regeneration mechanisms and be the foundation for development of hepatic cell-based therapies.
Assuntos
Linhagem Celular , Células Estreladas do Fígado , Células-Tronco Mesenquimais , Animais , Antígenos CD/metabolismo , Células da Medula Óssea/citologia , Diferenciação Celular , Transplante de Células , Células Estreladas do Fígado/citologia , Células Estreladas do Fígado/metabolismo , Humanos , Imunofenotipagem , Células-Tronco Mesenquimais/citologia , Células-Tronco Mesenquimais/metabolismo , Camundongos , Camundongos SCID , Células-Tronco Multipotentes/citologia , Neoplasias Experimentais/irrigação sanguínea , Neoplasias Experimentais/patologia , Neovascularização Patológica , OsteogêneseRESUMO
Neovascularization, an essential step for tumor progression and metastasis development, can be modulated by the presence of macrophages (Mps) in the tumor microenvironment. The ability of Mps to regulate the angiogenicity of the LMM3 tumor cell line was studied. Peritoneal Mps from LMM3 tumor-bearing mice (TMps) potentiate in vivo LMM3 angiogenicity. These results were confirmed by CD31 immunoblotting assays. The activity of TMps depended on nitric oxide synthase (NOS) and arginase (A) activity. By immunoblotting we evidenced that AI and AII isoforms were up-regulated in TMps while the inducible and neuronal NOS isoforms were highly expressed in normal Mps. TMps might positively modulate tumor growth by stimulating angiogenic cascade mainly through polyamine synthesis.
Assuntos
Arginina/metabolismo , Macrófagos Peritoneais/metabolismo , Neoplasias Experimentais/irrigação sanguínea , Neoplasias Experimentais/metabolismo , Neovascularização Patológica , Animais , Arginase/fisiologia , Feminino , Isoenzimas/metabolismo , Macrófagos Peritoneais/enzimologia , Camundongos , Camundongos Endogâmicos BALB C , Neoplasias Experimentais/enzimologia , Óxido Nítrico Sintase/fisiologia , Células Tumorais CultivadasRESUMO
Murine lung metatases growing undisturbed by the primary tumor were significantly inhibited by the concomitant resistance induced by a secondary subcutaneous implant of two unrelated tumors. Such inhibition was T-independent since it was also observed in nude mice; its full expression was dependent on the presence of the secondary tumor implant and it was exerted on both macroscopic and microscopic established metastases and not on the process of tumor cell dissemination from the primary tumor. Direct and indirect mechanisms seemed to be involved, the former affecting the metastatic cells per se by causing a decrease in proliferation and an increase in apoptosis while the latter affected neo-vascularization. These antitumor and antiangiogenic effects could be attributed to a serum factor induced by the unrelated tumors generating concomitant resistance. This factor proved to be heat, acid and alkaline resistant and dialysable; it was recovered in an HPLC column with maximum absorption at 215 and 266 nm; it was anionic at neutral pH, exhibiting free carboxil groups and one or more molecules of tyrosine, with a molecular weight between 870 and 1300 Dalton. Intravenous administration of this factor significantly inhibited lung metastases, decreasing mitosis and increasing apoptosis similar to that observed in the presence of the unrelated tumors.
Assuntos
Apoptose , Proteínas Sanguíneas/metabolismo , Neoplasias Pulmonares/patologia , Neoplasias Experimentais/patologia , Neovascularização Patológica/patologia , Animais , Substâncias de Crescimento/metabolismo , Neoplasias Pulmonares/irrigação sanguínea , Neoplasias Pulmonares/metabolismo , Neoplasias Pulmonares/secundário , Camundongos , Camundongos Endogâmicos BALB C , Invasividade Neoplásica , Neoplasias Experimentais/irrigação sanguínea , Neoplasias Experimentais/metabolismoRESUMO
Matrigel, a reconstituted extract of basement membrane, enhances the growth of different human cancer cell lines when transplanted into nude mice. Here that stimulation was confirmed in the BALB/c murine mammary-tumor cell line M3MC, as well as in human colon (SW948) and mammary (MDA-MB-468) carcinoma cell lines transplanted in nude and SCID mice, respectively. Subcutaneous and intra-mammary fat-pad inoculations of Matrigel alone generated an angiogenic response which was macroscopically evident by day 9. Histological analysis of the local host reaction occurring at the site of injection revealed an early peripheral fibroblast response, followed by mononuclear cell infiltration, solid and hollow fibroblast cords projections from the edge to the center of the Matrigel plug, and finally capillary ingrowths. Conditioned media obtained from the gels generated in vivo, acted as very strong chemoattractants for mouse lung capillary endothelial cells, stimulating their motility between 38 and 82 times with respect to the control. Our results suggest an important role of host cells recruited by Matrigel, which could favor angiogenesis of the area and thus facilitate the growth of tumor cells co-inoculated with the basement membrane extract.