ISSN:
1573-0778
Keywords:
anticancer prostaglandin
;
cell cycle arrest
;
GS-Xpump
;
multidrug resistance-associated protein (MRP1)
;
p21
Source:
Springer Online Journal Archives 1860-2000
Topics:
Biology
,
Medicine
,
Process Engineering, Biotechnology, Nutrition Technology
Notes:
Abstract The biological function as well as gene expression of the MRP/GS-X pump is closely linked with cellular GSH metabolism. This article describes two important aspects, i.e., 1) a role of the MRP/GS-X pump in the modulation of cell cycle arrest induced by anticancer prostaglandins; 2) coordinated up-regulation of γ-glutamylcysteine synthetase γ-GCS) and MRP1 genes. The A and J series of prostaglandins (PGs) accumulate in the nuclei to suppress the proliferation of cancer cells. Δ7-Prostaglandin A1 (Δ7-PGA1) methyl ester, a synthetic anticancer PG, increased the mRNA level of the cyclin-dependent kinase inhibitor p21Sdi1/CIP1/WAF1 in human leukemia HL-60 cells. The induction of p21Sdi1/CIP1/WAF1 was associated with the accumulation of hypophosphorylated retinoblastoma protein (pRB) and the suppression of c-myc gene expression. Unlike HL-60 cells, cisplatin-resistant HL-60/R-CP cells were insensitive to Δ7-PGA1 methyl ester. While c-myc expression was transiently suppressed, neither G1 arrest nor hypophosphorylation of pRB was observed with the anticancer PG. Plasma membrane vesicles from HL-60/R-CP cells showed an enhanced level of GS-X pump activity toward the glutathione S-conjugate of Δ7-PGA1 methyl ester. GIF-0019, a potent inhibitor of the GS-X pump, dose-dependently enhanced the cellular sensitivity of HL-60/R-CP cells to Δ7-PGA1 methyl ester, resulting in G1 arrest. The GS-X pump is suggested to play a pivotal role in modulating the biological action of the anticancer PG. The expression of MRP1 and γ-GCS genes can be coordinately up-regulated by cisplatin, 1-[5-(4-amino-2-methyl)pyrimidyl]methyl-3-(2-chloroethyl)-3-nitrosourea (ACNU), and heavy metals in human cancer cells. For the up-regulation of these genes, both transcriptional and posttranscriptional regulations are considered to be involved.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1023/A:1008036015156
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