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Phenotypic Modulation (phenotypic + modulation)
Selected AbstractsVascular smooth muscle cell phenotypic modulation in culture is associated with reorganisation of contractile and cytoskeletal proteinsCYTOSKELETON, Issue 3 2001Nathalie F. Worth Abstract Smooth muscle cells (SMC) exhibit a functional plasticity, modulating from the mature phenotype in which the primary function is contraction, to a less differentiated state with increased capacities for motility, protein synthesis, and proliferation. The present study determined, using Western analysis, double-label immunofluorescence and confocal microscopy, whether changes in phenotypic expression of rabbit aortic SMC in culture could be correlated with alterations in expression and distribution of structural proteins. "Contractile" state SMC (days 1 and 3 of primary culture) showed distinct sorting of proteins into subcellular domains, consistent with the theory that the SMC structural machinery is compartmentalised within the cell. Proteins specialised for contraction (,-SM actin, SM-MHC, and calponin) were highly expressed in these cells and concentrated in the upper central region of the cell. Vimentin was confined to the body of the cell, providing support for the contractile apparatus but not co-localising with it. In line with its role in cell attachment and motility, ,-NM actin was localised to the cell periphery and basal cortex. The dense body protein ,-actinin was concentrated at the cell periphery, possibly stabilising both contractile and motile apparatus. Vinculin-containing focal adhesions were well developed, indicating the cells' strong adhesion to substrate. In "synthetic" state SMC (passages 2,3 of culture), there was decreased expression of contractile and adhesion (vinculin) proteins with a concomitant increase in cytoskeletal proteins (,-non-muscle [NM] actin and vimentin). These quantitative changes in structural proteins were associated with dramatic changes in their distribution. The distinct compartmentalisation of structural proteins observed in "contractile" state SMC was no longer obvious, with proteins more evenly distributed throughout the cytoplasm to accommodate altered cell function. Thus, SMC phenotypic modulation involves not only quantitative changes in contractile and cytoskeletal proteins, but also reorganisation of these proteins. Since the cytoskeleton acts as a spatial regulator of intracellular signalling, reorganisation of the cytoskeleton may lead to realignment of signalling molecules, which, in turn, may mediate the changes in function associated with SMC phenotypic modulation. Cell Motil. Cytoskeleton 49:130,145, 2001. © 2001 Wiley-Liss, Inc. [source] Different roles of proteolipids and 70-kDa subunits of V-ATPase in growth and death of cultured human cellsGENES TO CELLS, Issue 6 2003Hong Zhan Background: The vacuolar-type proton-translocating adenosine triphosphatase (V-ATPase) plays important roles in cell growth and tumour progression. V-ATPase is composed of two distinct structures, a hydrophilic catalytic cytosolic sector (V1) and a hydrophobic transmembrane sector (V0). The V1 sector is composed of 5,8 different subunits with the structure A3B3C1D1E1F1G1H1. The V0 sector is composed of 5 different subunits with the structure 1161381191166. The over-expression of 16-kDa proteolipid subunit of V-ATPase in the perinuclear region of the human adventitial fibroblasts promotes phenotypic modulation that contributes to neointimal formation and medial thickening. A relationship between oncogenicity and the expression of the 16-kDa proteolipid has also been suggested in human pancreatic carcinoma tissue. Results: We found that the mRNA levels of the 16-kDa proteolipid but not of the 70-kDa subunit of V-ATPase in human myofibroblasts were more abundant in serum-containing medium (MF(+) cells) than serum-free medium (MF(,) cells). In HeLa cells, the levels of mRNA and protein of the 16-kDa, 21-kDa or 70-kDa were clearly suppressed when the corresponding anti-sense oligonucleotides were administered to the culture medium. The growth rate and viability (mostly due to necrosis) of HeLa cells were reduced markedly by the 16-kDa and 21-kDa anti-sense, but little by the 70-kDa anti-sense, and not at all by any sense oligonucleotides. The localization of 16-kDa/21-kDa proteolipid subunits was different from that of the 70-kDa subunit in HeLa cells. Conclusion: These results suggest that the 16-kDa and 21-kDa proteolipid subunits of the V0 sector play crucial roles in growth and death of cultured human cells. Our results may provide new insights into the mechanism and therapeutic implications for vessel wall hyperplasia and tumorigenesis. [source] Therapeutic strategy using phenotypic modulation of cancer cells by differentiation-inducing agentsCANCER SCIENCE, Issue 11 2007Yoshio Honma A low concentration of differentiation inducers greatly enhances the in vitro and in vivo antiproliferative effects of interferon (IFN), in several human cancer cells. Among the differentiation inducers tested, the sensitivity of cancer cells to IFN, was most strongly affected by cotylenin A. Cotylenin A, which is a novel fusicoccane diterpene glycoside with a complex sugar moiety, affected the differentiation of leukemia cells that were freshly isolated from acute myelogenous leukemia patients in primary culture. Tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) and its receptor DR5 were early genes induced by the combination of cotylenin A and IFN, in carcinoma cells. Neutralizing antibody to TRAIL inhibited apoptosis, suggesting that cotylenin A and IFN, cooperatively induced apoptosis through the TRAIL signaling system. Combined treatment preferentially induced apoptosis in human lung cancer cells while sparing normal lung epithelial cells. In an analysis of various cancer cell lines, ovarian cancer cells were highly sensitive to combined treatment with cotylenin A and IFN, in terms of the inhibition of cell growth. This treatment was also effective toward ovarian cancer cells that were refractory to cisplatin, and significantly inhibited the growth of ovarian cancer cells as xenografts without apparent adverse effects. Ovarian cancer cells from patients were also sensitive to the combined treatment in primary cultures. Combined treatment with cotylenin A and IFN, may have therapeutic value in treating human cancers including ovarian cancer. (Cancer Sci 2007; 98: 1643,1651) [source] | ||||||||||