[Metaphase chromosomes of human multiple myeloma cells of line U-266: karyotype and morpho-functional characteristics of nucleolar organizer regions]. / Metafaznye khromosomy kletok linii mnozhestvennoi mielomy cheloveka U-266: kariotip i morfofunktsional'naia kharakteristika iadryshkoobrazuiushchikh raionov.

Human multiple myeloma (MM) cell lines are widely used to investigate chromosome rearrangements typical for this disease. However, during cell cultivation both numeral and structural chromosome rearrangements usually take place in addition to changes of structural and functional status of particular chromosome regions. We investigated karyotype and morpho-functional status of nucleolar organizer regions (NORs) in human cell line MM U-266. Cytogenetic analysis (G-banding) showed karyotypic stability and balanced chromosome set in hypodiploid (n = 44) U-266 cells. We found the presence of rearranged chromosomes, typical for U-266, which retained throughout many year cell cultivation. At the same time, further chromosome rearrangements were shown, along with a tendency of cells to polyploidization. Using FISH (rDNA-probe) and AgNOR-staining techniques, we found that only 4 of 8 NORS were Ag positive (AgNOR), whose dimensions varied from 1 to 3 units of arbitrary scale (u.a.s.). The average summarized AgNOR size was 7.19 +/- 0.03 u.a.s. Peculiarities of the NOR morpho-functional status in U-266 cells are discussed.

[Functional morphology of nucleolus organizer regions of chromosomes and nucleoli in human multiple myeloma cell lines. I. Variation of the morphology and silver staining of nucleolus organizer regions of chromosomes in RMPI 8226 and U 266 cell lines with different level of differentiation of during 7 days after cell passage]. / Funktsional'naia morfologiia iadryshkoobrazyiushchikh raionov khromosom i iadryshek v kletkakh linii mnozhestvennoi mielomy cheloveka.I.Izmenenie morfologii i kharactera serebreniia iadryshkoobr azuiushchikh raionov khromosom kletochnykh linii RPMI 8226 i U 266, razlichaiushchikhsia po stepeni differentsirovki, na protiazhenii 7 sut posle pereseva kletok.

The morphology and Ag-staining of nucleoli in human multiple myeloma cell lines RPMI 8226 and U 266, distinguished from each other in the differentiation degree, were quantitatively studied, and the production of immunoglobulins or their fragments by the line cells was evaluated throughout 7 days after cell seeding. The less differentiated cell line RPMI 8226 and the high differentiated cell line U 266 were revealed to differ in both the initial level of immunoglobulin production and dynamics of immunoglobulin accumulation in culture medium. The total number of Ag-stained nucleolar-organizer regions (AgNORs) per nucleus in cells RPMI 8226 was significantly higher than in cells U 266 in all times after seeding of the cells. In both cell lines changes in the quantity and shape of nucleoli and also in the total number of AgNORs per nucleus and pattern of AgNORs distribution within nucleoli correlated with the cell cycle phase. Relationships between morphofunctional changes in nucleoli and the differentiation degree and proliferative activity of the cells, and also between the number of Ag-positive nucleolar-organizing metaphase chromosomes and the functional activity of interphase AgNORs are discussed.

[Functional morphology of nuclear organizer regions of chromosomes and of nucleoli in cells of human multiple myeloma cell lines. II.Relationship between immunoglobulin E production and argentophilia of nuclear organizer regions of chromosomes in U 266 cell line]. / Funktsional'naia morfologiia iadryshkoobrazuiushchikh raionov khromosom i iadryshek v kletkakh linii mnozhestvennoi mielomy cheloveka.II. Vzaimootnoshenie produktsii immunoglobulina E i argentof il'nosti iadryshkoobrazuiushchikh raionov khromosom v kletkakh linii U 266.

The IgE content in both cytoplasm and culture medium of U 266 myeloma cells, was studied by the enzyme-linked immunoassay in correlation with Ag-staining of NORs of chromosomes in their nuclei throughout 9 days after cell seeding. Proliferative activity of the cells was evaluated with 3H-thymidine labeling. The average values of both the cytoplasmic IgE content and its secretion level in U 266 cell population, being in logarithmic growth phase, were higher in S-phase cells as compared with G1-cells. On comparison of results of the present and previous (Turilova et al., 1998) studies it was revealed that U 266 myeloma cell line had a high stability of cell proliferation kinetics and IgE secretion and the dynamics of Ag-NORs-staining, while the number of argentophilic grains in the cell nuclei in the present experiment was higher to correlate with an enhanced IgE production. It is suggested that Ag-NORs-staining reflects the level of specific functional activity of cells in the U 266 line.

[The autocrine regulation of proliferation in cell cultures. I. A study of the heparin-binding factors with growth-stimulating activity contained in media conditioned with transformed rat fibroblasts]. / Autokrinnaia reguliatsiia proliferatsii v kul'turakh kletok. I. Issledovanie geparinsviazyvaiushchikh faktorov s rostostimuliruiushchei aktivnost'iu, soderzhashchikhsia v sredakh, konditsionirovannykh transformirovannymi fibroblastami krysy.

A study was made of the medium conditioned by spontaneously transformed rat embryo fibroblasts of line Rec1-sf, which are capable of unlimited reproduction in medium free of serum and of other endogenous growth factors (c-medium). Addition of c-medium to stationary cultures of nontransformed rat embryo fibroblasts (REF), spontaneously transformed REF (line Rec1), and cells of Rec1-sf stimulated the incorporation of 3H-thymidine by 1.5-6 times. SDS-polyacrilamide-gel electrophoresis of proteins, marked by 35S-metionine of c-medium of the cell line Rec 1-sf, demonstrated that this medium had proteins with molecular mass from 10 to 110 kDa. The fractionating divisible by 100 ultra-concentrates of c-medium with utilization of heparin-sepharose allowed to isolate two types of heparin-binding proteins. The proteins of the first type took about 5% of all the proteins of c-medium; they were eluted with 1.1 M NaCl and stimulated the incorporation of 3H-thymidine in REF, Rec1 and Rec1-sf cultures by 1.3-1.9 times. The second type proteins took about 1% of all the proteins of c-medium and were eluted with 2M NaCl, and, like the main endogenic basic growth factor of fibroblasts, stimulated the incorporation of 3H-thymidine into REF and Rec1-sf, but not into the culture of Rec1 line cells. The results obtained are discussed in terms of a hypothesis of autocrine regulation of cell proliferation.