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1.
Gordon Sato 《Cytotechnology》2008,57(2):111-114
Lack of differentiated functions of the tissue of origin in tissue culture thought to be due to dedifferentiation was shown
to be due to selective overgrowth of fibroblasts. Enrichment culture techniques, (alternate animal and culture passage), designed
to give the functionally differentiated cells selective advantage over the fibroblasts resulted in a large number of functionally
differentiated clonal strains. Thus the dogma of dedifferentiation was destroyed. It is proposed to substitute the dedifferentiation
hypothesis with the hypothesis that cells in culture accurately represent cells in vivo without the complex in vivo environment.
With the development of hormonally defined media, combined with functionally differentiated clonal cell lines, the potential
of tissue culture studies is greatly augmented. Hormonal responses and dependencies can be discovered in culture and the discovery
of dependencies of cancer cells has led to a new rationale for therapy. 相似文献
2.
The demonstration that the “dedifferentiation” of cells commonly observed in the early days of tissue culture was due to selective overgrowth of fibroblasts led to enrichment culture techniques (alternate animal and culture passage) designed to give a selective advantage to functionally differentiated tumor cells. These experiments resulted in the derivation of a large number of functionally differentiated clonal strains of a range of cell types. These results gave rise to the hypothesis that cells in culture accurately represent cells in vivo but without the complex in vivo environment. This concept has been strengthened with the development of hormonally defined culture media in combination with functionally differentiated clonal cell lines, which have augmented the potential of tissue culture studies. The use of hormonally defined media in place of serum-supplemented media demonstrates that hormonal responses and dependencies can be discovered in culture. Discoveries of hormonal dependencies of cancer cells has led to therapies targeting intracellular signaling pathways while discoveries of hormonal responses of pluripotent cells are helping to identify the potential application of stem cells. In these and other ways tissue culture technology will continue to contribute to solving problems of human health. 相似文献
3.
Janusz W. Rak Robert S. Kerbel 《In vitro cellular & developmental biology. Animal》1993,29(9):742-748
Summary In previous experiments it was shown that injection into syngeneic CBA/J mice of cell mixtures containing an excess of non-metastatic
SP1 mouse mammary carcinoma cells with aras transfected metastatic variant of SP1 called C1, always resulted in the eventual dominance of the C1 subpopulation at the
site of inoculation. This occurred despite the growth rates of the two cell populations being identical in vivo when grown
separately. The means by which the C1 subpopulation achieved “clonal dominance” is thought to involve its responsiveness to
stimulatory paracrine growth factors liberated by the non-metastatic SP1 population. The clonal dominance process, however,
could not be recapitulated in conventional monolayer tissue culture conditions in which SP1 and C1 cells were grown together
in high concentrations of serum, i.e. under non-limiting culture conditions. We now show that clonal dominance of C1 cells
can be observed when the cell mixture is maintained in tissue culture for extended periods, or when the cells are grown under
selective, limiting conditions, some of which may mimic growth conditions in vivo more accurately. These conditions were a)
growth in low (limiting) serum concentrations; and b) growth as three-dimensional multicellular aggregates, i.e. as “tumor
spheroids”. Under all of these conditions dominance of the C1 subpopulation always took place, but with an efficiency 6- to
40-fold less than generally observed in vivo. C1 cells were also able to form more stable (compact) spheroids compared to
SP1 cells. Entrapment of the latter in mixed C1/SP1 spheroids increased the recovery of the SP1 cells suggesting some kind
of “rescue” mechanism in which cells are protected from physical forces by three-dimensional structure. The relevance of these
in vitro interactions for clonal dominance in primary tumors and metastasis in vivo are discussed. 相似文献
4.
In the leaves of rice (Oryza sativa), stomatal initials arose from two asymmetric cell divisions and a symmetric division. Guard mother cells (GMCs) and long
cells in stomatal files (LCSs) were formed through the first asymmetric division of the precursor cell of GMCs. Subsidiary
cells (SCs) were produced by the second asymmetric division of subsidiary mother cells or LCSs. Following SC formation, GMCs
divided once symmetrically to generate guard cells and then differentiated terminally to form mature stomata. The developmental
patterns of long cells, prickle hairs and short cells (phellem cells and silica cells) were also examined. Interestingly,
we found that the different developmental stages of stomata and epidermal cells occurred in the similar location of immature
leaves of the same phyllotaxis. In addition, two spacing patterns (“one stoma, one long cell” and “one short cell row”) probably
exist in rice leaves. 相似文献
5.
Rinkevich B 《Marine biotechnology (New York, N.Y.)》2011,13(3):345-354
Despite several decades of extensive research efforts, there is yet no single permanent cell line available from marine invertebrates
as these cells stop dividing in vitro within 24–72 h after their isolation, starting cellular quiescence. This ubiquitous
quiescent state should be modified in a way that at least some of the quiescent cells will become pluripotent, so they will
have the ability to divide and become immortal. Following the above need, this essay introduces the rationale that the discipline
of marine invertebrates’ cell culture should gain from applying of two research routes, relevant to mammalian systems but
less explored in the marine arena. The first is the use of adult stem cells (ASC) from marine organisms. Many marine invertebrate
taxa maintain large pools of ASC in adulthood. Ample evidence attests that these cells from sponges, cnidarians, flatworms,
crustaceans, mollusks, echinoderms, and ascidians play important roles in maintenance, regeneration, and asexual cloning,
actively proliferating in vivo, resembling the vertebrates’ cancer stem cells features. The second route is to target resting
somatic cell constituents, manipulating them in the same way as has recently been performed on mammalian induced pluripotent
stem (iPS) cells. While “iPS cells” are the outcome of an experimental manipulation, ASC are natural and rather frequent in
a number of marine invertebrates. Above two cell categories reveal that there are more than a few types of seeds (cells) waiting
to be sowed in the right soil (in vitro environmental conditions) for acquiring stemness and immortality. This rationale carries
the potential to revolutionize the discipline of marine invertebrate cell cultures. When cultured “correctly,” ASC and “iPS
cells” from marine invertebrates may stay in their primitive stage and proliferate without differentiating into cells lineages,
harnessing the stem cell’s inherent abilities of self-replication versus differentiated progenies, toward the development
of immortal cell lines. 相似文献
6.
Walter E. Finkbeiner Lorna T. Zlock Irum Mehdi Jonathan H. Widdicombe 《In vitro cellular & developmental biology. Animal》2010,46(5):450-456
There are two main epithelial cell types in the secretory tubules of mammalian glands: serous and mucous. The former is believed
to secrete predominantly water and antimicrobials, the latter mucins. Primary cultures of human airway gland epithelium have
been available for almost 20 yr, but they are poorly differentiated and lack clear features of either serous or mucous cells.
In this study, by varying growth supports and media, we have produced cultures from human airway glands that in terms of their
ultrastructure and secretory products resemble either mucous or serous cells. Of four types of porous-bottomed insert tested,
polycarbonate filters (Transwells) most strongly promoted the mucous phenotype. Coupled with the addition of epidermal growth
factor (EGF), this growth support produced “mucous” cells that contained the large electron-lucent granules characteristic
of native mucous cells, but lacked the small electron-dense granules characteristic of serous cells. Furthermore, they showed
high levels of mucin secretion and low levels of release of lactoferrin and lysozyme (markers of native serous cells). By
contrast, growth on polyethylene terephthalate filters (Cyclopore) in medium lacking EGF produced “serous” cells in which
small electron-dense granules replaced the electron-lucent ones, and the cells had high levels of lactoferrin and lysozyme
but low levels of mucins. Measurements of transepithelial resistance and short-circuit current showed that both “serous” and
“mucous” cell cultures possessed tight junctions, had become polarized, and were actively secreting Cl. 相似文献
7.
Jeanette Ridge Jacqueline Muller Philip Noguchi Esther H. Chang 《In vitro cellular & developmental biology. Animal》1991,27(5):417-424
Summary We investigated the long-term effects of continuous gamma interferon (γ-IFN) treatment on A431, a human squamous carcinoma
cell line. Cells were grown in an in vitro culture system, which over time produces cohesive cell masses (“tumoroids”) exhibiting
three-dimensional, histotypically differentiated structures, e.g., keratin “pearls,” intercellular bridges (desmosomes), elongated
flattened cells (squames) and stratification. The effects of γ-IFN on cell growth, morphology and stage of differentiation
were assessed at different treatment times by light and electron microscopy and by immunohistochemical staining using antibodies
to keratins 1 and 14 and to filaggrin, markers of specific stages of keratinocyte differentiation. Our results show that A431
cells have the capacity for spontaneous differentiation, that this capacity is significantly enhanced and accelerated by γ-IFN
treatment leading to terminal differentiation and extensive cell death by 2 wk. Despite continuous exposure to IFN, a small
number of viable, undifferentiated cells remain. Their proliferation, evident by 3 wk, reconstitutes the tumoroid which once
again contains the full range of differentiating cell types. 相似文献
8.
Yokoyama A Muneta T Nimura A Koga H Mochizuki T Hata Y Sekiya I 《Cell and tissue research》2007,329(3):469-478
Elastic cartilage-derived cells cultured two-dimensionally with FGF2 and corticosteroid produce gel-type masses that become
mature cartilage when injected into a subcutaneous pocket. This unique method has previously been clinically applied for treatments
of nasal augmentation. However, the components of the gel-type mass and the mechanism of its synthesis remain unknown. Here,
we have investigated the components of the gel-type mass produced by elastic cartilage-derived cells, and whether this gel-type
mass can be produced by using other cell sources or other media. Human elastic cartilage-derived cells from auricular cartilage,
hyaline cartilage-derived cells from articular cartilage, and mesenchymal stem cells from synovium were cultured in three
media: “redifferentiation medium” containing FGF2 and dexamethasone; “chondrogenic medium” containing bone morphogenetic protein-2,
transforming growth factor-β3, and dexamethasone specific for in vitro chondrogenesis of mesenchymal stem cells; control medium.
The elastic cartilage-derived cells cultured in redifferentiation medium produced a gelatinous matrix positive for Alcian
blue. During culture, the amount of chondroitin 4-sulfate, chondroitin 6-sulfate, and especially hyaluronan increased. However,
the expression of RNAs for most chondrogenic genes did not increase. We also reproduced cartilage tissue formation by the
injection of elastic cartilage-derived cells with the gelatinous mass into the subcutaneous space of the nude mouse. The synthesis
of gelatinous matrix in vitro and the formation of cartilage tissue in vivo could be obtained only for the combination of
elastic cartilage-derived cells with redifferentiation medium.
This study was supported in part by grants from the “Japan Society for the Promotion of Science (19591752)” and “Center of
Excellence Program for Frontier Research on Molecular Destruction and Reconstruction of Tooth and Bone in Tokyo Medical and
Dental University” to Takeshi Muneta, and the “Japan Society for the Promotion of Science (18591657)” to Ichiro Sekiya. 相似文献
9.
Growth and differentiation of human keratinocytes without a feeder layer or conditioned medium 总被引:1,自引:0,他引:1
Summary An improved procedure has been developed for clonal growth of normal human epidermal keratinocytes (HK) without feeder cells
or conditioned medium. The use of medium 199, supplemented with 0.4 μg/ml hydrocortisone (HC) and 20% (v/v) whole fetal bovine
serum (wFBS) and conditioned overnight by 3T3 cells, eliminated the need for a feeder layer of lethally irradiated 3T3 cells
for HK growth. Several other media with equivalent conditioning and supplementation failed to support satisfactory multiplication
of HK, including Dulbecco's modified Eagle's medium, which is normally used for growth of HK with a feeder layer. Increasing
the concentration of HC to 10 μg/ml (2.8×10−5
M) made possible clonal growth of HK without any conditioning of the medium. The addition of 10−5
M putrescine, 10−5
M vitamin B12, or 3.7×10−6
M β-estradiol further enhanced growth in unconditioned medium. Substantially greater improvement was obtained by the addition
of pituitary extract or fractions prepared from pituitary extract. In medium 199 supplemented with 10 μg/ml HC, 20% (v/v)
wFBS, and 0.15 mg/ml each of two pituitary fractions, single HK attach with a colony-forming efficiency equal to that in conditioned
medium and form stratified, keratinized colonies that grow to confluency and can be subcultured. These results make it clear
that HK do not require special “conditioning factors” from fibroblasts for clonal growth and differentiation in culture. Thus,
factors directly involved in growth and the expression of differentiation can be analyzed without the interfering effects
of any other type of cell. Preliminary studies with epidermal growth factor (EGF), which stimulates growth and extends life
span of HK grown in the presence of fibroblasts, have shown that, in the absence of fibroblasts, EGF has no effect either
on clonal growth or on cumulative multiplication potential of HK.
This paper contains material from a thesis submitted to the Graduate School of the University of Colorado, Boulder, by Donna
M. Peehl in partial fulfillment of the requirements for the Ph.D. degree.
This work was supported by Grant CA 15305 from the National Cancer Institute and Grant AG 00310 from the National Institute
on Aging. 相似文献
10.
Katherine H. Chen Mercedes A. Paz Paul M. Gallop 《In vitro cellular & developmental biology. Plant》1977,13(1):49-54
Summary The action of hydralazine on collagen prolyl hydroxylation was studied in a cell culture system using WI-38 fibroblasts. The
prolyl hydroxylation level was determined by a method involving the digestion of collagen by bacterial collagenase and the
examination of specific peptides. The presence of low concentrations of hydralazine (0.2 mM) in both “young” and “old” fibroblast
cultures strongly inhibited collagen prolyl hydroxylation. The degree of inhibition was greater in serum-deficient cultures.
No significant improvement in the degree of hydroxylation was observed by increasing either ascorbate or iron levels in the
hydralazine-containing cultures in which hydroxylation was inhibited. Some of the reported side effects of hydralazine seen
in patients might be related to its inhibitory effects on mixed function oxidative (MFO) hydroxylation systems. While the
ascorbate dependence of the prolyl hydroxylase system of WI-38 decreased with the “age” of the culture, hydralazine inhibition
of hydroxylation was dramatic with cultures of all “ages”.
This work was supported by NIH grants nos. AM15671, AM1675 and HD07376, and fellowship no. HD01998. 相似文献
11.
Development of improved media and culture conditions for clonal growth of normal diploid cells 总被引:1,自引:0,他引:1
Richard G. Ham Wallace L. McKeehan 《In vitro cellular & developmental biology. Plant》1978,14(1):11-22
Summary Multiplication of normal diploid cells in culture is controlled by a complex set of interacting extracellular variables. The
amount of serum protein needed for colony formation by such cells is affected directly by many of the other variables, including
the nature of the culture surface, the type of trypsinization procedure used, and the qualitative and quantitative composition
of the culture medium. By a sequential process of adjusting all of these variables to optimum values for cellular multiplication
with minimal amounts of serum protein, we have been able to obtain clonal growth of normal human and chicken cells with less
than 500 μg per ml dialyzed serum protein. Precise quantitative adjustment of nutrient concentrations is particularly important.
The multiplication-promoting functions of serum can be classified operationally as “replaceable” (those that can be replaced
by modifying the medium or the culture conditions) and “nonreplaceable” (those that we have not yet been able to replace).
Elimination of the requirement for replaceable functions of serum has improved greatly the specificity and sensitivity of
the bioassay for the nonreplaceable functions. The nonreplaceable multiplication-promoting activity from fetal bovine serum
for human diploid fibroblasts has been separated from fetuin and serum albumin and purified approximately 15-fold.
Presented in the Opening Symposium on Nutritional Factors and Differentiation at the 28th Annual Meeting of the Tissue Culture
Association, New Orleans, Louisiana, June 6–9, 1977.
This work was supported by Contract 223-74-1156 from the Bureau of Biologics, U.S. Food and Drug Adminsstration, Grant AG
00310 from the National Institute on Aging, and Grant CA 15305 from the National Cancer Institute. 相似文献
12.
D. Gaillard R. Négrel G. Serrero-Davé C. Cermolacce G. Ailhaud 《In vitro cellular & developmental biology. Plant》1984,20(2):79-88
Summary Ob17 is a clonal cell line isolated from the epididymal fat pad of C57 BL/6J ob/ob mouse that differentiates into adiposelike
cells in serum-supplemented medium. In serum-free medium, this cell line shows increased growth under the addition of insulin,
transferrin, fibroblast growth factor (FGF), and a factor present in extract of rat submaxillary gland (SMGE). This medium
is referred to as 4F. Epidermal growth factor or nerve growth factor cannot replace SMGE, whereas partially purified platelet
extract can substitute for FGF but only partially for SMGE. 4F Medium is able to support the proliferation of cells from other
established preadipocyte clonal lines, HGFu and 3T3-F442A, and also of preadipocyte cells isolated from the stromal-vascular
fraction of rat and mouse adipose tissues. In each case 4F medium is insufficient to support the differentiation of these
cells into adipocytes. Ob17 cells grown and maintained in serum-free hormone-supplemented medium retain the ability to convert
to adiposelike cells after serum addition. This serum requirement for differentiation cannot be substituted by the addition
of growth hormone or of other putative adipogenic factors, or both. The results are discussed with respect to the requirements
for growth and differentiation of the 3T3-L1 and 1246 preadipocyte cell lines previously described.
This work was supported by the “Centre National de la Recherche Scientifique” (Grant 1208-Biochimie du Développement and Grant
4162-Endocrinologie), by the “Ministère de la Recherce et de la Technologie” (Grant 81-L-1322), by the “Fondation pour la
Recherche Médicale,” by NATO (Grant 1704), and by the “Institut National de la Santé et de la Recherche Médicale” (Grant 827006). 相似文献
13.
The process of cellular transformation has been amply studied in vitro using immortalized cell lines. Immortalized cells never
have the normal diploid karyotype, nevertheless, they cannot grow over one another in cell culture (contact inhibition), do
not form colonies in soft agar (anchorage-dependent growth) and do not form tumors when injected into immunodeficient rodents.
All these characteristics can be obtained with additional chromosome changes. Multiple genetic rearrangements, including whole
chromosome and gene copy number gains and losses, chromosome translocations, gene mutations are necessary for establishing
the malignant cell phenotype. Most of the experiments detecting transforming ability of genes overexpressed and/or mutated
in tumors (oncogenes) were performed using mouse embryonic fibroblasts (MEFs), NIH3T3 mouse fibroblast cell line, human embryonic
kidney 293 cell line (HEK293), and human mammary epithelial cell lines (mainly HMECs and MCF10A). These cell lines have abnormal
karyotypes and are prone to progress to malignantly transformed cells. This review is aimed at understanding the mechanisms
of cell immortalization by different “immortalizing agents”, oncogene-induced cell transformation of immortalized cells and
moderate response of the advanced tumors to anticancer therapy in the light of tumor “oncogene and chromosome addiction”,
intra-/intertumor heterogeneity, and chromosome instability. 相似文献
14.
Yan Xu Haihui Ye Jun Ma Huiyang Huang Guizhong Wang 《In vitro cellular & developmental biology. Animal》2010,46(8):708-717
Crustacean neurons, obtained from the cerebral ganglion of the mud crab Scylla paramamosain, were successfully cultured in vitro. They maintained typical morphological characteristics and showed better outgrowth in
modified Medium 199 (M199) medium than that in Liebowitz’s L-15 medium. Fetal bovine serum (FBS), muscle extracts, and hemolymph
of the mud crab S. paramamosain were added as supplements. Only 20% FBS could promote neuron outgrowth, while muscle extracts and hemolymph of S. paramamosain did not improve neuron outgrowth. For cell dissociation, both collagenase type I and trypsin worked well as determined by
initial cell viability and following cell outgrowth potential. More than six kinds of cells with different morphological characteristics
were identified in the neuron outgrowth. They were “small cells”, “veilers”, “branchers”, “multipolar cells”, “super-large
cell”, and “bipolar cells”. Among all of the cells, bipolar cells were identified for the first time in crustacean neurons
culture and they could live longer than other cells. The neurons could grow for more than a week before retraction and eventual
degradation. 相似文献
15.
16.
Palmer CP Mycielska ME Burcu H Osman K Collins T Beckerman R Perrett R Johnson H Aydar E Djamgoz MB 《European biophysics journal : EBJ》2008,37(4):359-368
We have developed a simple yet effective apparatus, based upon negative pressure directed to the tip of a micro-pipette, to
measure the adhesiveness of single cells. The “single cell adhesion measuring apparatus” (SCAMA) could differentiate between
the adhesion of strongly versus weakly metastatic cancer cells as well as normal cells. Adhesion was quantified as “detachment
negative pressure” (DNP) or “DNP relative to cell size” (DNPR) where a noticeable difference in cell size was apparent. Thus,
for rat and human prostate and human breast cancer cell lines, adhesiveness (DNPR values) decreased in line with increased
metastatic potential. Using the SCAMA, we investigated the effect of tetrodotoxin (TTX), a specific blocker of voltage-gated
Na+ channels (VGSCs), on the adhesion of rat and human prostate cancer cell lines of markedly different metastatic potential.
Following pretreatment with TTX (48 h with 1 μM), the adhesion values for the Mat-LyLu cells increased significantly 4.3-fold;
there was no effect on the AT-2 cells. For the strongly metastatic PC-3M cells, TTX treatment caused a significant (∼30%)
increase in adhesion. The adhesion of PNT2-C2 (“normal”) cells was not affected by the TTX pretreatment. The TTX-induced increase
in the adhesiveness of the strongly metastatic cells was consistent with the functional VGSC expression in these cells and
the proposed role of VGSC activity in metastatic cell behaviour. In conclusion, the SCAMA, which can be constructed easily
and cheaply, offers a simple and effective method to characterise single-cell adhesion and its modulation. 相似文献
17.
Richard I. Schwarz Deborah A. Farson Mina J. Bissell 《In vitro cellular & developmental biology. Plant》1979,15(12):941-948
Summary Primary avian tendon cells (PAT) maintain their embryonic state when cultured in medium F-12 with very low serum (0.2%) and
ascorbate (50 μg per ml); that is, they retain the potential for devoting 20–30% of their total protein synthesis to collagen.
However, if the cells are left at a confluent cell density or are derived from confluent cultures, this potential is irreversibly
decreased. This effect, along with poor medium formulations, probably accounts for the “dedifferentiation” process that occurs
when fibroblasts are cultured. In contrast, PAT cells kept at subconfluent cell densities retain the ability to synthesize
high levels of collagen. The one limitation in obtaining long-term cultures of high collagen-producing tendon cells in the
inability of serum at low concentrations to remain a potent mitogen after a few subcultures.
The quantitative loss of function has long been considered to be a cell culture artifact; however, we propose that this drop
in collagen synthesis is a reflection of the developmental programing of these cells. In separate series of experiments using
organ cultures, we show that tendon tissue from the embryo makes over 30% collagen, whereas, “young” tendons make 18% and
“older” tendons from the adult make less than 1%. Therefore, a quantitative drop in collagen synthesis would be expected if
normal development were to occur in culture. Our data are consistent with the idea that cultures of embryonic tendon cells
are triggered to mature by a mechanism that correlates with high cell density.
This investigation was supported in part by National Science Foundation Grant PCM 77-14982; in part by the Division of Biomedical
and Environmental Research of the Department of Energy under contract W-7405-ENG-48; and by a National Institutes of Health
Fellowship IF32 CA 05807-01, from the National Cancer Institute to R. I. S. 相似文献
18.
Judith Arnon Asher Ornoy Gideon Bach 《In vitro cellular & developmental biology. Plant》1988,24(12):1159-1164
Summary The effect of culture conditions on the ultrastructure and enzyme activities of cultured skin fibroblast cells relevant to
the diagnosis of lysosomal storage disorders are reported. The parameters examined were: pH of the culture media, type of
media, increasing cell passage, and day of harvest. Ultrastructural changes were defined in terms of the number of lysosome-like
inclusion bodies per cell according to a method devised in our laboratory and proven reliable in the detection of affected
individuals. Our biochemical results included determination of enzyme activities of β-hexosaminidase, α-mannosidase, β-glucuronidase-lysosmal
enzymes, arylsulfatase C, a microsomal marker, and 5' nucleotidase, a plasma membrane marker. Our results indicate that the
cellular ultrastructure is more sensitive than enzyme activity to changes in culture conditions. The resulting ultrastructural
“artifacts” observed under certain conditions were severe enough to result in a mistaken diagnosis. Due to certain difficulties
we had previously encountered in heterozygote cultures (for lysosmal storage disorders) of amniotic cells, we decided to examine
heterozygote cultures of skin fibroblasts. From these (preliminary) studies it seems that an evaluation in the pH over the
pysiologic levels in the culture media may help to define between normal individuals and affected heterozygotes. On the basis
of our results, we recommend that to minimize false positive ultrastructural results for the diagnosis of lysosomal storage
disorders, cultures be grown in minimal essential medium, the pH of the medium carefully monitored to remain below 7.4, examining
the cultures not later than cell Passage 8 and no later than Day 10 after subculture.
This work was part of the requirement for the fulfillment of a Ph.D. thesis (J. A.) submitted to the Hebrew University. This
work was supported in part by the Richard Meyer Fund for teratological research. 相似文献
19.
Anna Perzelova Ivana Macikova Marcienne Tardy Peter Mraz Ivan Bizik Juraj Steno 《Biologia》2007,62(5):633-640
Glial fibrillary acidic protein (GFAP) is an intermediate filament protein considered to be the best astroglial marker. However,
the predominant cell population in adult human brain tissue cultures does not express GFAP; these cells have been termed “glia-like”
cells. The basic question about histological origin of adult human brain cultures remains unanswered. Some authors showed
that “glia-like” cells in adult human brain cultures might be of non-glial origin. We examined primary explant tissue cultures
derived from 70 adult human brain biopsies. Within first 5–10 days approximately 5–10% of the small explants became attached.
Outgrowing cells were mostly flat cells. These cells formed confluent layer over 3–6 weeks in culture. At confluence the cultures
contained 2–5% of microglial cells, 0.1% GFAP-positive astrocytes, less than 0.01% oligodendrocytes and 95–98% GFAP-negative
“glia-like” cells. This population of flat “glia-like” cells was positively stained for vimentin, fibronectin, and 20–30%
of these cells stained for nestin. Our findings revealed that 1 mM dibutyryl-cAMP addition, in serum free conditions, induced
a reversible stellation in 5-10% of the flat “glia-like” cells but did not induce the expression of GFAP or nestin in morphologically
changed stellate cells. These results demonstrate that “glia-like” cells in primary adult human brain cultures constitute
heterogeneous cell populations albeit with similar morphological features. Two distinct subpopulations have been shown: (i)
the one immunostained for nestin; and (ii) the other reactive for dibutyryl-cAMP treatment. 相似文献
20.
Pedersen PL 《Journal of bioenergetics and biomembranes》2007,39(1):1-12
This introductory article to the review series entitled “The Cancer Cell’s Power Plants as Promising Therapeutic Targets”
is written while more than 20 million people suffer from cancer. It summarizes strategies to destroy or prevent cancers by
targeting their energy production factories, i.e., “power plants.” All nucleated animal/human cells have two types of power
plants, i.e., systems that make the “high energy” compound ATP from ADP and P
i
. One type is “glycolysis,” the other the “mitochondria.” In contrast to most normal cells where the mitochondria are the
major ATP producers (>90%) in fueling growth, human cancers detected via Positron Emission Tomography (PET) rely on both types
of power plants. In such cancers, glycolysis may contribute nearly half the ATP even in the presence of oxygen (“Warburg effect”).
Based solely on cell energetics, this presents a challenge to identify curative agents that destroy only cancer cells as they
must destroy both of their power plants causing “necrotic cell death” and leave normal cells alone. One such agent, 3-bromopyruvate
(3-BrPA), a lactic acid analog, has been shown to inhibit both glycolytic and mitochondrial ATP production in rapidly growing
cancers (Ko et al., Cancer Letts., 173, 83–91, 2001), leave normal cells alone, and eradicate advanced cancers (19 of 19)
in a rodent model (Ko et al., Biochem. Biophys. Res. Commun., 324, 269–275, 2004). A second approach is to induce only cancer
cells to undergo “apoptotic cell death.” Here, mitochondria release cell death inducing factors (e.g., cytochrome c). In a
third approach, cancer cells are induced to die by both apoptotic and necrotic events. In summary, much effort is being focused
on identifying agents that induce “necrotic,” “apoptotic” or apoptotic plus necrotic cell death only in cancer cells. Regardless
how death is inflicted, every cancer cell must die, be it fast or slow. 相似文献