betadex and Carcinoma

The co-delivery of a drug and a target gene has become a primary strategy in cancer therapy. Based on our previous study, a synthesized star‑shaped co‑polymer consisting of β‑cyclodextrin (CD) and a poly(L‑lysine) dendron (PLLD) was used to co-deliver docetaxel (DOC) and matrix metalloproteinase 9 (MMP‑9) small interfering RNA, via CD‑PLLD/DOC/MMP‑9 complexes, into mice implanted with HNE‑1 human nasopharyngeal carcinoma (NPC) tumor cells in vivo. Unlike the commonly used amphiphilic co‑polymer micelles, the obtained CD derivative may be used directly for a combined delivery of nucleic acid and hydrophobic DOC without a complicated micellization process. In vivo assays demonstrated that CD‑PLLD/DOC/MMP‑9 inhibited HNE‑1 tumor growth and decreased proliferating cell nuclear antigen expression levels, indicating a potential strategy for NPC therapy. In addition, the distribution of DOC and MMP‑9 was investigated; CD‑PLLD/DOC/MMP‑9 complexes were phagocytized in reticuloendothelial systems, including the liver and spleen, which requires further study. Furthermore, the complexes did not cross the blood‑brain barrier due to their large molecular size, suggesting they may be relatively safe. Additionally, the complexes mediated increased DOC concentrations with prolonged blood circulation and EGFP expression in HNE‑1 tumors. These results suggest the future potential application of CD-PLLD/DOC/MMP-9 for NPC therapy.

Topics: Animals; beta-Cyclodextrins; Carcinoma; Cell Line, Tumor; Docetaxel; Drug Carriers; Humans; Matrix Metalloproteinase 9; Mice; Mice, Inbred BALB C; Mice, Nude; Nasopharyngeal Carcinoma; Nasopharyngeal Neoplasms; Polylysine; Proliferating Cell Nuclear Antigen; RNA, Small Interfering; Taxoids; Transplantation, Heterologous

The co-delivery of drug and gene has become the primary strategy in cancer therapy. Based on our previous work, to co-deliver docetaxel (DOC) and MMP-9 siRNA more efficiently for HNE-1 nasopharyngeal carcinoma therapy, a folate-modified star-shaped copolymer (FA-CD-PLLD) consisting of β-cyclodextrin (CD) and poly(L-lysine) dendron (PLLD) was synthesized, and then used for DOC and MMP-9 co-delivery. Different from commonly used amphiphilic copolymers micelles, the obtained CD derivative could be used directly for the combinatorial delivery of nucleic acid and hydrophobic DOC without a complicated micellization process. In vitro and in vivo assays are carried out to confirm the effectiveness of the target strategy and combined treatment. It was found that the conjugation of CD-PLLD with FA could enhance the DOC/MMP-9 delivery effect obviously, inducing a more significant apoptosis and decreasing invasive capacity of HEN-1 cells. In vivo assays showed that FA-CD-PLLD/DOC/MMP-9 could inhibit HNE-1 tumor growth and decrease PCNA expression effectively, indicating a promising strategy for nasopharyngeal carcinoma therapy. Moreover, the in vivo distribution of DOC and MMP-9, blood compatibility and toxicity are also explored.

Topics: Animals; Apoptosis; beta-Cyclodextrins; Carcinoma; Cell Line, Tumor; Docetaxel; Drug Delivery Systems; Female; Folic Acid; Gene Expression Profiling; Gene Expression Regulation, Neoplastic; Genetic Therapy; Humans; Hydrophobic and Hydrophilic Interactions; Magnetic Resonance Spectroscopy; Matrix Metalloproteinase 9; Mice; Mice, Inbred BALB C; Mice, Nude; Micelles; Nasopharyngeal Carcinoma; Nasopharyngeal Neoplasms; Polylysine; Proliferating Cell Nuclear Antigen; RNA, Small Interfering; Taxoids; Tissue Distribution; Transfection

Oxidative stress has emerged as an important pathogenic factor in the development of breast cancer. Cholesterol-rich membrane rafts or lipid rafts (LRs) are reported to play an important role in oxidative stress-induced signal transduction. NADPH oxidase-dependent reactive oxygen species (ROS) production is implicated in oxidative stress in human mammary epithelial cells. In the present study, we determined the expression and regulation of membrane-bound subunits by LRs in human breast cancer cells. We report that basal levels of gp91phox and p22phox are expressed in breast cancer cells. We demonstrate for the first time that disruption of LRs resulted in the downregulation of NADPH oxidase subunits in breast cancer cells. Cholesterol depletion by 10 mM methyl-β-cyclodextrin (MβCD) translocated both gp91phox and p22phox out of LRs. Moreover, lipid raft disruption decreased NADPH oxidase activity (21.1 ± 0.5% in MCF-7 and 28.9 ± 1.0 in BT-549 cells), which was reversed by cholesterol repletion (95%). Therefore, the results suggest that the integrity of LRs plays an important role in the regulation of NADPH oxidase activity in breast cancer cells.

Topics: beta-Cyclodextrins; Breast Neoplasms; Carcinoma; Cell Line, Tumor; Dose-Response Relationship, Drug; Down-Regulation; Female; Gene Expression Regulation, Enzymologic; Gene Expression Regulation, Neoplastic; Humans; Membrane Glycoproteins; Membrane Microdomains; NADPH Oxidase 2; NADPH Oxidases

In the following experiments, we sought to understand the triggering mechanism which propels galectin-3 to be secreted into the extracellular compartment from its intracellular stores in breast carcinoma cells. We also wanted to analyze in greater details the role of galectin-3 in cellular adhesion and spreading. To do this, we made use of two pairs of breast carcinoma cell lines where one of the pair has high expression of galectin-3 and the other low expression of the lectin. We determined that galectin-3 secreted into the conditioned medium of sub-confluent and spread cells in culture was quite low, almost negligible. However, once the cells were detached and rounded up, a mechano-sensing mechanism triggered the rapid secretion of galectin-3 into the conditioned medium. The secretion was constitutive as long as the cells remained detached. Galectin-3 was shown to be actively taken up from the conditioned medium by spreading cells. The cells which express and secrete high levels of galectin-3 adhered and spread much faster on plastic than those with reduced expression. The uptake of galectin-3 according to our data was important in cell spreading because if this process was compromised significantly, cells failed to spread. The data suggested that galectin-3 uptake modulates the adhesion plaques in that cells which express high levels of galectin-3 have thin-dot like plaques that may be suited for rapid adhesion and spreading while cells in which galectin-3 expression is reduced or knocked-down, have thick and elongated plaques which may be suited for a firmer adhesion to the substratum. Recombinant galectin-3 added exogenously reduced the thickness of the adhesion plaques of tumor cells with reduced galectin-3 expression. Taken together, the present data suggest that galectin-3 once externalized, is a powerful modulator of cellular adhesion and spreading in breast carcinoma cells.

Topics: 2-Hydroxypropyl-beta-cyclodextrin; beta-Cyclodextrins; Breast Neoplasms; Carcinoma; Cell Adhesion; Cell Line, Tumor; Cell Proliferation; Cells, Cultured; Extracellular Space; Focal Adhesions; Galectin 3; Humans; Mechanotransduction, Cellular; Protein Transport

There is considerable controversy at present concerning the mechanisms responsible for the cellular uptake of anandamide. One particular issue concerns whether fatty acid-free bovine serum albumin should be used in the assays, it having been argued that such a presence effectively prevents the specific uptake of anandamide. In the present study, it has been demonstrated that in the presence of a low (0.1%, w/v) concentration of fatty acid-free bovine serum albumin, a temperature-dependent and saturable (K(m) approximately 1 microM) uptake of anandamide into P19 embryonic carcinoma cells can be demonstrated using an incubation time of 4 min. Under these conditions, the uptake of anandamide at 4 degrees C is low at a substrate concentration of 100 nM. The uptake at 37 degrees C was not significantly reduced following treatment of the cells with either methyl-beta-cyclodextrin (50 microM) or mevinolin (1 microM), but was reduced by the FAAH inhibitor URB597 (1 microM) and inhibited by the transport inhibitor cum FAAH substrate AM404 with an IC(50) value of 12 microM. When a 45 s incubation time was used, the uptake of anandamide was not saturable at 37 degrees C over the concentration range tested (0.1-1 microM). Analysis of the data at 37 degrees C obtained with 45 s, 4 min and 15 min incubation times revealed a very rapid (i.e. complete by 45 s) non-saturable component followed by a slower saturable (K(m) approximately 1 microM) component of the uptake. It is concluded that the presence of a low concentration of fatty acid-free bovine serum albumin at a suitable concentration reduces non-specific binding (and release) of anandamide to cell culture wells, greatly reduces the cellular accumulation seen at 4 degrees C, and allows the visualisation of both non-saturable and saturable components of the uptake to be seen at 37 degrees C.

Topics: Amidohydrolases; Animals; Anticholesteremic Agents; Arachidonic Acids; beta-Cyclodextrins; Carcinoma; Cell Line, Tumor; Cholesterol; Embryo, Mammalian; Endocannabinoids; Hydroxymethylglutaryl-CoA Reductase Inhibitors; Lovastatin; Mice; Polyunsaturated Alkamides; Serum Albumin, Bovine