scholarly journals CHANGES IN SURFACE MORPHOLOGY OF CHINESE HAMSTER OVARY CELLS DURING THE CELL CYCLE

1973 ◽  
Vol 57 (3) ◽  
pp. 815-836 ◽  
Author(s):  
Keith Porter ◽  
David Prescott ◽  
Jearl Frye

Synchronized populations of Chinese hamster ovary (CHO) cells in confluent culture have been examined by scanning electron microscopy and their surface changes noted as the cells progress through the cycle. During G1 it is characteristic for cells to show large numbers of microvilli, blebs, and ruffles. Except for the ruffles, these tend to diminish in prominence during S and the cells become relatively smooth as they spread thinly over the substrate. During G2 microvilli increase in number and the cells thicken in anticipation of rounding up for mitosis. It appears that the changes observed here reflect the changing capacity of CHO cells during the cycle to respond to contact with other cells in the population, because, as noted in the succeeding paper (Rubin and Everhart), CHO cells in sparse nonconfluent cultures do not show the same wide range of changes during the cell cycle. Normal, nontransformed cells of equivalent type in confluent culture are essentially devoid of microvilli, blebs, and ruffles. The relation of these surface configurations to the internal structure of the cell is discussed.

1977 ◽  
Vol 73 (1) ◽  
pp. 200-205 ◽  
Author(s):  
A S Weissfeld ◽  
H Rouse

When exponentially growing CHO cells were deprived of arginine (Arg), cell multiplication ceased after 12 h, but initiation of DNA synthesis continued: after 48 h of starvation with continuous [3H]thymidine exposure, 85% of the population had incorporated label, as detected autoradiographically. Consideration of the distribution of exponential cells in the various cell cycle phases leads to a calculation that most cells in G1 at the time that Arg was removed, as well as those in S, engaged in some DNA synthesis during starvation. In contrast, isoleucine (Ile)-starved cells did not initiate DNA synthesis, as has been reported by others. Experiments with cells synchronized by mitotic selection confirmed this difference in Arg- and Ile- deprived behavior, but also showed that cells which underwent the mitosis leads to G1 transition during Arg starvation remained arrested in G1 (G0?). The results suggest that Arg-deprived cells continue to maintain some proliferative function(s) while Ile-deprived cells do not.


1999 ◽  
Vol 22 (3) ◽  
pp. 407-413 ◽  
Author(s):  
Maria Cristina P. Araújo ◽  
Francisca da Luz Dias ◽  
Sergio N. Kronka ◽  
Catarina S. Takahashi

Naturally occurring antioxidants have been extensively studied for their capacity to protect organisms and cells from oxidative damage. Many plant constituents including turmeric and curcumin appear to be potent antimutagens and antioxidants. The effects of turmeric and curcumin on chromosomal aberration frequencies induced by the radiomimetic agent bleomycin (BLM) were investigated in Chinese hamster ovary (CHO) cells. Three concentrations of each drug, turmeric (100, 250 and 500 <FONT FACE="Symbol">m</FONT>g/ml) and curcumin (2.5, 5 and 10 <FONT FACE="Symbol">m</FONT>g/ml), were combined with BLM (10 <FONT FACE="Symbol">m</FONT>g/ml) in CHO cells treated during the G1/S, S or G2/S phases of the cell cycle. Neither turmeric nor curcumin prevented BLM-induced chromosomal damage in any phases of the cell cycle. Conversely, a potentiation of the clastogenicity of BLM by curcumin was clearly observed in cells treated during the S and G2/S phases. Curcumin was also clastogenic by itself at 10 µg/ml in two protocols used. However, the exact mechanism by which curcumin produced clastogenic and potentiating effects remains unknown.


Author(s):  
Shazid Md. Sharker ◽  
Md. Atiqur Rahman

Most of clinical approved protein-based drugs or under in clinical trial have a profound impact in the treatment of critical diseases. The mammalian eukaryotic cells culture approaches, particularly the CHO (Chinese Hamster Ovary) cells are mainly used in the biopharmaceutical industry for the mass-production of therapeutic protein. Recent advances in CHO cell bioprocessing to yield recombinant proteins and monoclonal antibodies have enabled the expression of quality protein. The developments of cell lines are possible to upgrade specific productivity. As a result, it holds an interesting area for academic as well as industrial researchers around the world. This review will concentrate on the recent progress of the mammalian CHO cells culture technology and the future scope of further development for the mass-production of protein therapeutics.


1984 ◽  
Vol 4 (1) ◽  
pp. 173-180 ◽  
Author(s):  
S W Stanfield ◽  
D R Helinski

Small polydisperse circular (spc) DNA was isolated and cloned, using BglII from Chinese hamster ovary (CHO) cells. The properties of 47 clones containing at least 43 different BglII fragments are reported. The majority of the clones probably contain entire sequences from individual spcDNA molecules. Most of the clones were homologous to sequences in CHO cell chromosomal DNA, and many were also homologous to mouse LMTK- cell chromosomal sequences. The majority of homologous CHO cell chromosomal sequences were repetitive, although a few may be single copy. Only a small fraction of cloned spcDNA molecules were present in every cell; most occurred less frequently than once in 15 cells. Localization studies indicated that at least a portion of spcDNA is associated with the nucleus in CHO cells.


2004 ◽  
Vol 149 (2-3) ◽  
pp. 125-136 ◽  
Author(s):  
Pei-Ming Yang ◽  
Shu-Jun Chiu ◽  
Kwei-Ann Lin ◽  
Lih-Yuan Lin

1977 ◽  
Vol 73 (3) ◽  
pp. 601-615 ◽  
Author(s):  
RR Gould ◽  
GG Borisy

The structure and function of the centrosomes from Chinese hamster ovary (CHO) cells were investigated by electron microscopy of negatively stained wholemount preparations of cell lysates. Cells were trypsinized from culture dishes, lysed with Triton X-100, sedimented onto ionized, carbon-coated grids, and negatively stained with phosphotungstate. The centrosomes from both interphase and dividing cells consisted of pairs of centrioles, a fibrous pericentriolar material, and a group of virus-like particles which were characteristic of the CHO cells and which served as markers for the pericentriolar material. Interphase centrosomes anchored up to two dozen microtubules when cells were lysed under conditions which preserved native microtubules. When Colcemid-blocked mitotic cells, initially devoid of microtubules, were allowed to recover for 10 min, microtubules formed at the pericentriolar material, but not at the centrioles. When lysates of Colcemid-blocked cells were incubated in vitro with micotubule protein purified from porcine brain tissue, up to 250 microtubules assembled at the centrosomes, similar to the number of microtubules that would normally form at the centrosome during cell division. A few microtubules could also be assembled in vitro onto the ends of isolated centrioles from which the pericentriolar material had been removed, forming characteristic axoneme- like bundles. In addition, microtubules; were assembled onto fragments of densely staining, fibrous material which was tentatively identified as periocentriolar material by its association of CHO can initiate and anchor microtubules both in vivo and in vitro.


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