Effect of cadmium on cell cycle progression in chinese hamster ovary cells

2004 ◽  
Vol 149 (2-3) ◽  
pp. 125-136 ◽  
Author(s):  
Pei-Ming Yang ◽  
Shu-Jun Chiu ◽  
Kwei-Ann Lin ◽  
Lih-Yuan Lin
Endocrinology ◽  
2004 ◽  
Vol 145 (12) ◽  
pp. 5862-5874 ◽  
Author(s):  
Yasushi Kaburagi ◽  
Ryo Yamashita ◽  
Yuzuru Ito ◽  
Hitoshi Okochi ◽  
Ritsuko Yamamoto-Honda ◽  
...  

Abstract To analyze the roles of insulin receptor substrate (IRS) proteins in insulin-stimulated cell cycle progression, we examined the functions of rat IRS-1 and IRS-3 in Chinese hamster ovary cells overexpressing the human insulin receptor. In this type of cell overexpressing IRS-1 or IRS-3, we showed that: 1) overexpression of IRS-3, but not IRS-1, suppressed the G1/S transition induced by insulin; 2) IRS-3 was more preferentially localized to the nucleus than IRS-1; 3) phosphorylation of glycogen synthase kinase 3 and MAPK/ERK was unaffected by IRS-3 overexpression, whereas that of protein kinase B was enhanced by either IRS; 4) overexpressed IRS-3 suppressed cyclin D1 expression in response to insulin; 5) among the signaling molecules regulating cyclin D1 expression, activation of the small G protein Ral was unchanged, whereas insulin-induced gene expression of c-myc, a critical component for growth control and cell cycle progression, was suppressed by overexpressed IRS-3; and 6) insulin-induced expression of p21, a cyclin-dependent kinase inhibitor, was decreased by overexpressed IRS-3. These findings imply that: 1) IRS-3 may play a unique role in mitogenesis by inhibiting insulin-stimulated cell cycle progression via a decrease in cyclin D1 and p21 expressions as well as suppression of c-myc mRNA induction in a manner independent of the activation of MAPK, protein kinase B, glycogen synthase kinase 3 and Ral; and 2) the interaction of IRS-3 with nuclear proteins may be involved in this process.


1990 ◽  
Vol 10 (4) ◽  
pp. 1584-1592
Author(s):  
C A Hoy ◽  
E D Lewis ◽  
R T Schimke

The effect of tritiated thymidine incorporation on DNA replication was studied in Chinese hamster ovary cells. Rapidly eluting (small) DNA from cells labeled with 2 microCi of [3H]thymidine per ml (200 microCi/mmol) for 60 min matured to a large nonelutable size within approximately 2 to 4 h, as measured by the alkaline elution technique. However, DNA from cells exposed to 10 microCi of [3H]thymidine per ml (66 microCi/mmol) was more rapidly eluting initially and did not mature to a nonelutable size during subsequent incubation. Semiconservative DNA replication measured by cesium chloride gradient analysis of bromodeoxyuridine-substituted DNA was also found to be affected by the final specific activity of the [3H]thymidine used in the labeling protocol. Dramatic cell cycle perturbations accompanied these effects on DNA replication, suggesting that labeling protocols commonly used to study DNA metabolism produce aberrant DNA replication and subsequent cell cycle perturbations.


1990 ◽  
Vol 10 (4) ◽  
pp. 1584-1592 ◽  
Author(s):  
C A Hoy ◽  
E D Lewis ◽  
R T Schimke

The effect of tritiated thymidine incorporation on DNA replication was studied in Chinese hamster ovary cells. Rapidly eluting (small) DNA from cells labeled with 2 microCi of [3H]thymidine per ml (200 microCi/mmol) for 60 min matured to a large nonelutable size within approximately 2 to 4 h, as measured by the alkaline elution technique. However, DNA from cells exposed to 10 microCi of [3H]thymidine per ml (66 microCi/mmol) was more rapidly eluting initially and did not mature to a nonelutable size during subsequent incubation. Semiconservative DNA replication measured by cesium chloride gradient analysis of bromodeoxyuridine-substituted DNA was also found to be affected by the final specific activity of the [3H]thymidine used in the labeling protocol. Dramatic cell cycle perturbations accompanied these effects on DNA replication, suggesting that labeling protocols commonly used to study DNA metabolism produce aberrant DNA replication and subsequent cell cycle perturbations.


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.


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