Lipid rafts/caveolae are membrane platforms for signaling molecules that regulate various cellular functions, including cell survival. To better understand the role of rafts in tumor progression and therapeutics, we investigated the effect of raft disruption on cell viability and compared raft levels in human cancer cell lines versus their normal counterparts. Here, we report that cholesterol depletion using methyl-beta cyclodextrin caused anoikis-like apoptosis, which in A431 cells involved decreased raft levels, Bcl-xL down-regulation, caspase-3 activation, and Akt inactivation regardless of epidermal growth factor receptor activation. Cholesterol repletion replenished rafts on the cell surface and restored Akt activation and cell viability. Moreover, the breast cancer and the prostate cancer cell lines contained more lipid rafts and were more sensitive to cholesterol depletion-induced cell death than their normal counterparts. These results indicate that cancer cells contain increased levels of rafts and suggest a potential use of raft-modulating agents as anti-cancer drugs.

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A new series of stable, unsymmetrical squaraine near-IR sensitizers (JK-216 and JK-217), which are assembled using both thiophenyl pyrrolyl and indolium groups, exhibit a panchromatic light harvesting up to 780 nm. The JK-216 based cell exhibited a record efficiency of 6.29% for near-IR DSSCs. In addition, the JK-217 device showed an excellent stability under a light soaking test at 60 °C for 1000 h.

Ordered multimodal porous carbon (OMPC) was explored as a counter electrode in ruthenium complex dye-sensitized solar cells (DSSCs) and CdSe quantum-dot solar cells (QDSCs). The unique structural characteristics such as large surface area and well-developed three-dimensional (3-D) interconnected ordered macropore framework with open mesopores embedded in the macropore walls make the OMPC electrodes have high catalytic activities and fast mass transfer kinetics toward both triiodide/iodide and polysulfide electrolytes. The efficiency (ca. 8.67%) of the OMPC based DSSC is close to that (ca. 9.34%) of the Pt based one. Most importantly, the QDSC employing OMPC material presents a high efficiency of up to 4.36%, which is significantly higher than those of Pt- and activated carbon based solar cells, ca. 2.29% and 3.30%, respectively.

Exosomes are small membrane vesicles that are released into the extracellular environment during fusion of multivesicular bodies with plasma membrane. Exosomes are secreted by various cell types including hematopoietic cells, normal epithelial cells and even some tumor cells. They are known to carry MHC class I, various costimulatory molecules and some tetraspanins. Recent studies have shown the potential of using native exosomes as immunologic stimulants. Here, we demonstrate a novel means of using exosomes engineered to express a specific tumor antigen to generate an immune response against tumors. We expressed a target tumor antigen, human MUC1 (hMUC1), in 2 MHC typedistinct mouse cell lines, CT26 and TA3HA. Analysis of exosomes purified from these cells revealed that exosomes contained the target MUC1 antigen on their surfaces as well as other welldescribed exosomal proteins, including Hsc70 and MHC class I molecules. In addition, both autologous and allogenic exosomes were able to stimulate the activation of immune cells and suppress hMUC1-expressing tumor growth in a MUC1-specific and doserelated manner. Therefore, these data suggest that exosomes can be engineered from tumor cell lines to deliver a target immunogen capable of inducing an effective immune response and that they may represent a new cell-free tumor vaccine. © 2004 Wiley-Liss, Inc. Key words: exosomes; membrane vesicles; hMUC1; Hsc70; cell-free tumor vaccine Exosomes were initially described as small membrane vesicles (40 -90 nm in diameter), which are released from reticulocytes in order to eliminate unnecessary proteins, such as transferrin receptor (TfR) or acetylcholine esterase, during the process of their final maturation into red blood cells. [1][2][3][4] These extracellular vesicles are also produced by various kinds of hematopoietic cells, including mast cells, platelets, T lymphocytes, B lymphocytes and dendritic cells (DCs), as well as by intestinal epithelial cells. [5][6][7][8][9][10][11][12][13] Exosomes are known to originate from the inward budding of limiting membrane of multivesicular bodies (MVBs), and these internal vesicles of MVBs are released into the extracellular space by fusion of MVBs with the plasma membrane. 14 Proteomic analysis of DC-or B-cell-derived exosomes revealed selective enrichment of a subset of cellular proteins, including antigen-presenting proteins such as MHC class I and II molecules, heat shock proteins (HSPs), targeting-related MFG-E8 and tetraspanins such as CD9, CD63, CD81 and CD82. [15][16][17][18] In addition, a recent study by Hegman et al. has demonstrated that exosomes secreted by human mesothelioma cells contain a discrete set of proteins associated with antigen presentation, signal transduction, migration and adhesion. 19 The function(s) of exosomes are not well defined but have been reflected by their protein composition and cellular origins. 14,20 Although exosomes are known to discard membrane proteins such as transferrin receptors in reticulocytes, several lines of studies have sug...

Background. Although most patients with classical Hodgkin's lymphoma (cHL) have a long survival duration, the current risk stratification is imperfect. A recent study suggested a prognostic role for the peripheral blood absolute lymphocyte count/absolute monocyte count (ALC/AMC) ratio at diagnosis in cHL. It is intriguing to investigate the significance of the ALC/AMC ratio in relation to tumor-associated macrophages (TAMs), yet another prognostic factor for cHL.Methods. We examined the prognostic impact of the ALC, AMC, and ALC/AMC ratio in 312 cHL patients (median age, 37 years) using receiver operating characteristic curve analysis for optimal cutoff values, and compared these with TAM content.Results. The median follow-up was 65 months (range, 0.1-245 months). On univariate analysis, a low ALC/AMC

Discrete spherical polypyrrole (PPy) nanoparticles with a uniform diameter of $85 nm and electrical conductivity of $10 S cm À1 were fabricated by chemical oxidative polymerization within micelles composed of myristyl trimethyl ammonium bromide (MTAB) and decyl alcohol as the nanoreactors. A methanol-based colloidal dispersion containing 5 wt% PPy was dropcast directly onto fluorine-doped tin oxide (FTO) glass to use as counter electrodes (CEs) in dye-sensitized solar cells (DSSCs). The surface resistivity of the PPy layer on the FTO glass decreased from 624 to 387 U sq À1 after post-doping with concentrated HCl vapor for 1 min. The DSSCs made of PPy/FTO and HCl-doped PPy/FTO CEs exhibited power conversion efficiencies of $5.28 and $6.83%, respectively under standard AM 1.5 sunlight illumination. The post-doped and highly oxidized PPy allowed the electrons to move into the PPy layer readily and facilitated the electrocatalytic reaction of the I 3 À /I À redox couple, giving enhanced cell performance. Moreover, the cell efficiency was enhanced to $7.73% with further fine tuning of the electrolyte composition, which is comparable to the value ($8.2%) using conventional Pt CEs.

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