Human colon adenocarcinoma LS180 parental cell line and selected variants, characterized by different metastatic capacity were used to examine, whether a correlation exists between β-actin expression, its subcellular distribution and metastatic potential of these cells. Cytosolic fraction (supernatant 105000 × g), isolated from the tumor cells was used as a source for actin quantification. The higher level of β-actin was observed in the cytosol of three selected sublines to compare with LS180 parental line. Statistically significant increase of β-actin level in highly motile EB3 cells variant should be underlined to compare with the other sublines. Distinct differences in the phenotype of adenocarcinoma cell variants were found, such as the changes in cells shape, cells spreading and ability to attach to the surface of culture dish. Actin cytoskeleton was visualized with fluorescence microscopy application and microfilaments rhodamine-conjugated phalloidin staining. β-actin subcellular localization was done by immunofluorescence staining with monoclonal anti-β actin antibodies. In the elongated cells (LS180, 3LNLN), this isoactin is dispersed in the whole cell body and concentrates in pseudopods and at the leading edges, when in the rounded variant (EB3) β-actin dominates mainly in cortical ring under cellular membrane and it is also seen in the subtle protrusions. Summary of our former (Nowak et al., 2002, Acta Biochim. Polon., 49: 823) and current data lead to the conclusion that there is a distinct correlation between metastatic capacity of examined human colon adenocarcinoma cells, the state of actin polymerization, actin cytoskeleton organization and β-actin expression.
Immunomodulatory features, unlimited possibilities of self-renewal, multidirectional diff erentiation, the ability to selectively migrate to the injury site – these are the features of stem cells which allow them to be seen as a promising therapeutic tool. The study shows the division of stem cells on the basis of their ability to diff erentiate and origin, the source of their acquisition and the possible therapeutic eff ect on diabetes and its organ complications. The safety aspects as well as the limitations of the analysed methods are discussed.
PL
Właściwości immunomodulacyjne, nieograniczone możliwości samoodnawiania, wielokierunkowe różnicowanie oraz zdolność selektywnej migracji do miejsca uszkodzeń – to cechy komórek macierzystych, pozwalające postrzegać je jako obiecujące narzędzie terapeutyczne. W pracy omówiono podział komórek macierzystych ze względu na zdolność różnicowania i pochodzenie, źródła ich pozyskiwania oraz możliwy efekt terapeutyczny w cukrzycy i jej powikłaniach narządowych. Analizowano również aspekty bezpieczeństwa oraz ograniczenia omawianej metody.
The hepatoma Morris 5123 tumor growth is accompanied by changes in actin content and polymerization (Malicka-Błaszkiewicz et al. (1995) Mat. Med. Pol., 27, 115-118; Nowak et al. (1995) J. Exp. Cancer Res. 14, 37-40). Presently actin isoforms from cytosol and cytoskeleton fractions were separated by SDS/PAGE and identified with antibodies directed against different actin isoforms. Actin isolated from the cytosol by affinity chromatography on DNase I bound to agarose shows the presence of only one protein spot on 2D gel electrophoresis corresponding to the mobility of the rabbit α skeletal muscle actin (M^r 43000) and isoelectric point equal to 5.3. It interacts only with monoclonal anti β actin isoform antibodies, posing the question of differential affinity of actin isoforms to DNase I.
Four human colon adenocarcinoma cell line variants with different metastatic potential were used to examine whether a correlation exists between actin level, state of actin polymerization and invasiveness of tumour cells. Monomeric (G), total (T) and filamentous (F) actin were determined in the cytosolic fraction of these cells. A statistically significant decrease in G actin level and increase in the state of actin polymerization (measured by F:G actin ratio) were found in the cytosol of three cell variants with higher metastatic potential and invasiveness (EB3, 3LNLN, 5W) compared with the parental cell line (LS180). Our experimental data lead to the conclusion that there is a correlation between the metastatic capacity of human colon adenocarcinoma cells and the state of actin polymerization.
Gelsolin, one of a major actin-binding proteins, is involved in the regulation of actin cytoskeleton organization by its severing and capping activity towards actin filaments. Human colon adenocarcinoma cell line LS180 and its selected variants of different metastatic potential were used to check for a correlation between gelsolin level, its subcellular localization and the invasive capacity of cells. Based on immunoblotting experiments, a decreased level of gelsolin was detected in the most invasive 5W subline when compared to the parental cell line LS180. The intracellular distribution of actin filaments and gelsolin in colon adenocarcinoma cells was examined by confocal microscopy. In the 5W subline, unlike in the other examined cells, gelsolin was colocalized with filamentous actin at the cell periphery. In summary, in human colon adenocarcinoma cells, gelsolin level and its subcellular distribution seem to correlate with their metastatic potential.
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