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Multicellular Spheroids (multicellular + spheroid)
Selected AbstractsA New Method to Prepare Multicellular Spheroids in Cancer Cell Lines Using a Thermo-Reversible Gelation PolymerARTIFICIAL ORGANS, Issue 7 2003Satoshi Tsukikawa Abstract: The purpose of this study is to utilize the thermo-reversible gelation polymer in which the sol-gel transitting phase is reversibly changed by temperature in a three-dimensional culture system. Human cancer cells have been observed to form multicellular spheroids, whereas fibroblasts slowly develop into small spheroids with the culture medium including this polymer. This polymer has some advantages for use as a culture material, as follows: first, cancer cells grow three-dimensionally in the aqueous solution of this polymer; second, it is easy to harvest cells or spheroids in the aqueous solution of this polymer by simply cooling down the temperature; and third, the culture medium including this polymer is so translucent that the cells or spheroids can be observed through a phase-contrast microscope. We thus conclude that this polymer is a very useful material for three-dimensional cultures. [source] Novel MRI and fluorescent probes responsive to the Factor XIII transglutaminase activityCONTRAST MEDIA & MOLECULAR IMAGING, Issue 4 2010Lorenzo Tei Abstract Transglutaminases, including factor XIII and tissue transglutaminase, participate in multiple extracellular processes associated with remodeling of the extracellular matrix during wound repair, blood clotting, tumor progression and fibrosis of ischemic injuries. The aim of this work was to evaluate a novel substrate analog for transglutaminase optimized by molecular modeling calculations (DCCP16), which can serve for molecular imaging of transglutaminase activity by magnetic resonance imaging and by near-infrared imaging. Experimental data showed covalent binding of Gd,DCCP16 and DCCP16-IRIS Blue to human clots, to basement membrane components and to casein in purified systems as well as in three-dimensional multicellular spheroids. In vivo, DCCP16 showed enhancement with a prolonged retention in clots and tumors, demonstrating the ability to detect both factor XIII and tissue transglutaminase mediated covalent binding of the contrast material. Copyright © 2010 John Wiley & Sons, Ltd. [source] Hierarchically Assembled Mesenchymal Stem Cell Spheroids Using Biomimicking Nanofilaments and Microstructured Scaffolds for Vascularized Adipose Tissue EngineeringADVANCED FUNCTIONAL MATERIALS, Issue 14 2010Taek Gyoung Kim Abstract Composite multicellular spheroids composed of mesenchymal stem cells (MSCs) and synthetic biodegradable nanofilaments are fabricated. Extracellular-matrix-mimicking nanofilaments, prepared from transverse fragmentation of semicrystalline poly(L -lactic acid) nanofibers and subsequent surface modification with cell adhesive peptides, are used to form composite multicellular spheroids with MSCs by cellular self-assembly. The size of the composite spheroids could be readily controlled with the integrated amount of the nanofilaments. The composite spheroids show enhanced adipogenic potential compared to homotypic spheroids. The resultant spheroids are used as building blocks for 3D biohybrid construction with the assistance of a microstructured scaffold fabricated by a direct polymer melt deposition process. An angiogenic growth factor, basic fibroblast growth factor, is also locally delivered in a sustained fashion from the heparinized scaffold surface for facile neovascularization of adipogenic tissue. The produced multiscaled and multifunctional hybrid MSC construct enable the successful formation of vascularized adipose tissue in vivo. [source] The effect of focal adhesion kinase gene silencing on 5-fluorouracil chemosensitivity involves an Akt/NF-,B signaling pathway in colorectal carcinomasINTERNATIONAL JOURNAL OF CANCER, Issue 1 2010Yuying Chen Abstract Multicellular resistance (MCR) is produced because multicellular spheroids (MCSs) are formed with a broad cell,cell connection when cultured in three-dimensions, which limits the clinical treatment efficacy in solid tumors. Focal adhesion kinase (FAK) plays an important role in apoptosis, survival and cell adhesion between cells and their extracellular matrix. In this study, we investigated the expressions of FAK, Akt and NF-,B in human colorectal cancer (CRC), and the effects of FAK gene silencing on MCSs formation and 5-fluorouracil (5-FU) chemosensitivity in colon carcinoma MCSs culture cells. In CRC samples, FAK, Akt and NF-,B were overexpressed. The positive expression of FAK correlated notably with lymph node metastasis and cellular differentiation. Positive expressions of Akt and NF-,B were significantly related to cellular differentiation and lymph node metastasis, respectively. Furthermore, positive expression of FAK correlated with that of Akt and NF-,B. The expression of FAK was inhibited significantly by a small hairpin RNA targeting FAK. Knockdown of FAK reversed the formation and aggregation of MCSs, significantly decreased the 50% inhibitory concentration of 5-FU, and markedly increased MCS culture cells apoptosis. These effects were associated with reduced levels of Akt and NF-,B. These results indicate that suppressing FAK expression potentiated 5-FU-induced cytotoxicity and contributed to its chemosensitizing effect by suppressing Akt/NF-,B signaling in colon carcinoma MCS culture cells. These data also imply that FAK mediates MCR of CRC through the survival signaling pathway FAK/Akt/NF-,B. [source] Signalling responses linked to betulinic acid-induced apoptosis are antagonized by MEK inhibitor U0126 in adherent or 3D spheroid melanoma irrespective of p53 statusINTERNATIONAL JOURNAL OF CANCER, Issue 5 2006Manuel Rieber Abstract MEK1/2 inhibitors like U0126 can potentiate or antagonize the antitumor activity of cytotoxic agents such as cisplatin, paclitaxel or vinblastine, depending on the drug or the target cells. We now investigated whether U0126, differentially regulates melanoma signaling in response to UV radiation or betulinic acid, a drug lethal against melanoma. This report shows that U0126 inhibits early response (ERK) kinase activation and cyclin A expression in wt p53 C8161 melanoma exposed to either UV radiation or betulinic acid. However, U0126 does not protect from UV damage, but counteracts betulinic acid-mediated apoptosis in the same cells. Protection from the latter drug by joint treatment with U0126 was also evident in wt p53 MelJuso melanoma and mutant p53 WM164 melanoma. The latter cells were the most responsive to betulinic acid, showing a selective decline in the cdk4 protein, without a comparable change in other key cell cycle proteins like cdc2, cdk2, cdk7 or cyclin A, prior to apoptosis-associated PARP fragmentation. Laser scanning cytometry also showed that betulinic acid induced a significant increase in chromatin condensation in WM164 melanoma irrespective of whether they were in adherent form or as multicellular spheroids. All these betulinic acid-induced changes were counteracted by U0126. Our data show for the first time that (a) cdk4 protein is an early target of betulinic acid-induced apoptosis and (b) unrestricted ERK signaling favours betulinic acid-induced apoptosis, but this is counteracted by U0126, partly through counteracting chromatin condensation and restoring Akt activation decreased by betulinic acid treatment. © 2005 Wiley-Liss, Inc. [source] The role of angiogenesis, vascular maturation, regression and stroma infiltration in dormancy and growth of implanted MLS ovarian carcinoma spheroidsINTERNATIONAL JOURNAL OF CANCER, Issue 4 2004Assaf Gilead Abstract MLS ovarian epithelial carcinoma multicellular spheroids xenografted subcutaneously in CD-1 nude mice displayed growth delay, or dormancy, of up to 52 days. In the study reported here, implanted MLS spheroids were used for testing the role of angiogenesis and vascular maturation in triggering the initiation of tumor progression. The kinetics and impact of neovascular maturation and functionality, in dormancy, and growth of MLS spheroid xenografts were studied noninvasively by BOLD contrast MRI. MR data were supported by histologic staining for biotinylated albumin as a blood pool marker and alpha-smooth muscle actin (alpha-SMA) as marker for perivascular mural cells. Although the tumor periphery showed higher levels of total and mature vasculature than normal skin, the fraction of mature out of the total vessels as detected by MRI vascular maturation index (VMIMRI) was significantly lower in the tumor both before and after tumor exit from dormancy. The neovasculature induced by the implanted spheroid was unstable and showed cycles of vessel growth and regression. Surprisingly, this instability was not restricted to the immature vessels, but rather included also regression of mature vessels. During dormancy, neovasculature was predominantly peripheral with no infiltration into the implanted spheroid. Infiltration of alpha-SMA positive stroma cells into the spheroid was associated with functional vascularization and tumor growth. Thus, stroma infiltration and vascular maturation are an important checkpoint linking the angiogenic switch with initiation of tumor progression. © 2003 Wiley-Liss, Inc. [source] Curcumin-induced apoptosis in ovarian carcinoma cells is p53-independent and involves p38 mitogen-activated protein kinase activation and downregulation of Bcl-2 and survivin expression and Akt signaling,MOLECULAR CARCINOGENESIS, Issue 1 2010Jane L. Watson Abstract New cytotoxic agents are urgently needed for the treatment of advanced ovarian cancer because of the poor long-term response of this disease to conventional chemotherapy. Curcumin, obtained from the rhizome of Curcuma longa, has potent anticancer activity; however, the mechanism of curcumin-induced cytotoxicity in ovarian cancer cells remains a mystery. In this study we show that curcumin exhibited time- and dose-dependent cytotoxicity against monolayer cultures of ovarian carcinoma cell lines with differing p53 status (wild-type p53: HEY, OVCA429; mutant p53: OCC1; null p53: SKOV3). In addition, p53 knockdown or p53 inhibition did not diminish curcumin killing of HEY cells, confirming p53-independent cytotoxicity. Curcumin also killed OVCA429, and SKOV3 cells grown as multicellular spheroids. Nuclear condensation and fragmentation, as well as DNA fragmentation and poly (ADP-ribose) polymerase-1 cleavage in curcumin-treated HEY cells, indicated cell death by apoptosis. Procaspase-3, procaspase-8, and procaspase-9 cleavage, in addition to cytochrome c release and Bid cleavage into truncated Bid, revealed that curcumin activated both the extrinsic and intrinsic pathways of apoptosis. Bax expression was unchanged but Bcl-2, survivin, phosphorylated Akt (on serine 473), and total Akt were downregulated in curcumin-treated HEY cells. Curcumin also activated p38 mitogen-activated protein kinase (MAPK) without altering extracellular signal-regulated kinase 1/2 activity. We conclude that p53-independent curcumin-induced apoptosis in ovarian carcinoma cells involves p38 MAPK activation, ablation of prosurvival Akt signaling, and reduced expression of the antiapoptotic proteins Bcl-2 and survivin. These data provide a mechanistic rationale for the potential use of curcumin in the treatment of ovarian cancer. © 2009 Wiley-Liss, Inc. [source] A New Method to Prepare Multicellular Spheroids in Cancer Cell Lines Using a Thermo-Reversible Gelation PolymerARTIFICIAL ORGANS, Issue 7 2003Satoshi Tsukikawa Abstract: The purpose of this study is to utilize the thermo-reversible gelation polymer in which the sol-gel transitting phase is reversibly changed by temperature in a three-dimensional culture system. Human cancer cells have been observed to form multicellular spheroids, whereas fibroblasts slowly develop into small spheroids with the culture medium including this polymer. This polymer has some advantages for use as a culture material, as follows: first, cancer cells grow three-dimensionally in the aqueous solution of this polymer; second, it is easy to harvest cells or spheroids in the aqueous solution of this polymer by simply cooling down the temperature; and third, the culture medium including this polymer is so translucent that the cells or spheroids can be observed through a phase-contrast microscope. We thus conclude that this polymer is a very useful material for three-dimensional cultures. [source] In vitro three-dimensional modelling of human ovarian surface epithelial cellsCELL PROLIFERATION, Issue 3 2009K. Lawrenson Objectives:, Ninety percent of malignant ovarian cancers are epithelial and thought to arise from the ovarian surface epithelium (OSE). We hypothesized that biological characteristics of primary OSE cells would more closely resemble OSE in vivo if established as three-dimensional (3D) cultures. Materials and methods:, OSE cells were cultured as multicellular spheroids (MCS) (i) in a rotary cell culture system (RCCS) and (ii) on polyHEMA-coated plastics. The MCSs were examined by electron microscopy and compared to OSE from primary tissues and cells grown in 2D. Annexin V FACS analysis was used to evaluate apoptosis and expression of extracellular matrix (ECM) proteins was analysed by immunohistochemical staining. Results:, On polyHEMA-coated plates, OSE spheroids had defined internal architecture. RCCS MCSs had disorganized structure and higher proportion of apoptotic cells than polyHEMA MCSs and the same cells grown in 2D culture. In 2D, widespread expression of AE1/AE3, laminin and vimentin were undetectable by immunohistochemistry, whereas strong expression of these proteins was observed in the same cells grown in 3D culture and in OSE on primary tissues. Conclusions:, Physiological and biological features of OSE cells grown in 3D culture more closely resemble characteristics of OSE cells in vivo than when grown by classical 2D approaches. It is likely that establishing in vitro 3D OSE models will lead to greater understanding of the mechanisms of neoplastic transformation in epithelial ovarian cancers. [source] | ||||||||||