Lysosomal sequestration of polyamine analogues in Chinese hamster ovary cells resistant to the S-adenosylmethionine decarboxylase inhibitor, CGP- 48664

Debora L. Kramer, Jennifer D. Black, Helmut Mett, Raymond J. Bergeron, Carl W. Porter

Research output: Contribution to journalArticle

10 Citations (Scopus)

Abstract

CGP-48664, an inhibitor of the polyamine biosynthetic enzyme S- adenosylmethionine decarboxylase (AdoMetDC), is presently undergoing Phase 1 clinical trials as an experimental anticancer agent. We have shown previously (D. L. Kramer et al., J. Biol. Chem., 270: 2124-2132, 1995) that Chinese hamster ovary (CHO) cells that are made resistant to the growth inhibitory effects of the drug overexpress AdoMetDC because of a stable gene amplification. Unexpectedly, these same cells (CHO/644) were found to be insensitive to the growth inhibitory effects of N1,N11-diethylnorspermine (DENSPM) - a polyamine analogue also undergoing Phase 1 clinical trials - despite accumulating ~5 times more analogue than parental cells. We now report that treatment of CHO/664 cells with DENSPM results in the formation of numerous large cytoplasmic vacuoles, which on the basis of electron microscopy and cytochemical staining seem to be lysosomal in origin. A series of newly established CHO cell lines made differentially resistant to 1, 3, 10, 30, and 100 μM CGP-48664 by chronic exposure were used to demonstrate that vacuole formation correlated with the accumulation of extremely high levels of DENSPM without increasing growth inhibition. These same cells were used to show that AdoMetDC gene overexpression as indicated by mRNA levels was unrelated to vacuole formation; cells resistant to 100 μM CGP-48664 displayed a 170-fold increase in AdoMetDC mRNA levels and formed vacuoles in response to DENSPM, whereas those resistant to 10 μM CGP-48664 displayed a 120-fold increase in AdoMetDC mRNA levels and failed to form vacuoles. Despite accumulating to high intracellular levels, DENSPM was much less effective than spermine at down-regulating ornithine decarboxylase and polyamine transport activities in highly resistant cells. Similarly, DENSPM was less able to induce spermidine/spermine N1-acetyltransferase activity in cells that formed vacuoles than in those that did not. Overall, natural polyamines failed to induce vacuoles and various anaIogues of DENSPM were used to probe the structural specificity of the effect. The data are consistent with the probability that DENSPM is sequestered to high concentrations in lysosomal vacuoles of CGP-48664-resistant cells and is, therefore, not available to interact with polyamine regulatory sites or to cytotoxically affect cell growth. In addition to implicating the lysosome as a potential new site of CGP-48664 drug action that could be involved in antitumor activity and/or host toxicities, the findings also suggest a potential mechanism of cell resistance to analogues such as DENSPM.

Original languageEnglish (US)
Pages (from-to)3883-3890
Number of pages8
JournalCancer Research
Volume58
Issue number17
StatePublished - Sep 1 1998

Fingerprint

4-amidinoindan-1-one 2'-amidinohydrazone
Adenosylmethionine Decarboxylase
Polyamines
Cricetulus
Ovary
Vacuoles
Clinical Trials, Phase I
Spermine
Growth
Messenger RNA

ASJC Scopus subject areas

  • Oncology
  • Cancer Research

Cite this

Lysosomal sequestration of polyamine analogues in Chinese hamster ovary cells resistant to the S-adenosylmethionine decarboxylase inhibitor, CGP- 48664. / Kramer, Debora L.; Black, Jennifer D.; Mett, Helmut; Bergeron, Raymond J.; Porter, Carl W.

In: Cancer Research, Vol. 58, No. 17, 01.09.1998, p. 3883-3890.

Research output: Contribution to journalArticle

@article{e2b75089e12849929e71c6b524e37eef,
title = "Lysosomal sequestration of polyamine analogues in Chinese hamster ovary cells resistant to the S-adenosylmethionine decarboxylase inhibitor, CGP- 48664",
abstract = "CGP-48664, an inhibitor of the polyamine biosynthetic enzyme S- adenosylmethionine decarboxylase (AdoMetDC), is presently undergoing Phase 1 clinical trials as an experimental anticancer agent. We have shown previously (D. L. Kramer et al., J. Biol. Chem., 270: 2124-2132, 1995) that Chinese hamster ovary (CHO) cells that are made resistant to the growth inhibitory effects of the drug overexpress AdoMetDC because of a stable gene amplification. Unexpectedly, these same cells (CHO/644) were found to be insensitive to the growth inhibitory effects of N1,N11-diethylnorspermine (DENSPM) - a polyamine analogue also undergoing Phase 1 clinical trials - despite accumulating ~5 times more analogue than parental cells. We now report that treatment of CHO/664 cells with DENSPM results in the formation of numerous large cytoplasmic vacuoles, which on the basis of electron microscopy and cytochemical staining seem to be lysosomal in origin. A series of newly established CHO cell lines made differentially resistant to 1, 3, 10, 30, and 100 μM CGP-48664 by chronic exposure were used to demonstrate that vacuole formation correlated with the accumulation of extremely high levels of DENSPM without increasing growth inhibition. These same cells were used to show that AdoMetDC gene overexpression as indicated by mRNA levels was unrelated to vacuole formation; cells resistant to 100 μM CGP-48664 displayed a 170-fold increase in AdoMetDC mRNA levels and formed vacuoles in response to DENSPM, whereas those resistant to 10 μM CGP-48664 displayed a 120-fold increase in AdoMetDC mRNA levels and failed to form vacuoles. Despite accumulating to high intracellular levels, DENSPM was much less effective than spermine at down-regulating ornithine decarboxylase and polyamine transport activities in highly resistant cells. Similarly, DENSPM was less able to induce spermidine/spermine N1-acetyltransferase activity in cells that formed vacuoles than in those that did not. Overall, natural polyamines failed to induce vacuoles and various anaIogues of DENSPM were used to probe the structural specificity of the effect. The data are consistent with the probability that DENSPM is sequestered to high concentrations in lysosomal vacuoles of CGP-48664-resistant cells and is, therefore, not available to interact with polyamine regulatory sites or to cytotoxically affect cell growth. In addition to implicating the lysosome as a potential new site of CGP-48664 drug action that could be involved in antitumor activity and/or host toxicities, the findings also suggest a potential mechanism of cell resistance to analogues such as DENSPM.",
author = "Kramer, {Debora L.} and Black, {Jennifer D.} and Helmut Mett and Bergeron, {Raymond J.} and Porter, {Carl W.}",
year = "1998",
month = "9",
day = "1",
language = "English (US)",
volume = "58",
pages = "3883--3890",
journal = "Cancer Research",
issn = "0008-5472",
publisher = "American Association for Cancer Research Inc.",
number = "17",

}

TY - JOUR

T1 - Lysosomal sequestration of polyamine analogues in Chinese hamster ovary cells resistant to the S-adenosylmethionine decarboxylase inhibitor, CGP- 48664

AU - Kramer, Debora L.

AU - Black, Jennifer D.

AU - Mett, Helmut

AU - Bergeron, Raymond J.

AU - Porter, Carl W.

PY - 1998/9/1

Y1 - 1998/9/1

N2 - CGP-48664, an inhibitor of the polyamine biosynthetic enzyme S- adenosylmethionine decarboxylase (AdoMetDC), is presently undergoing Phase 1 clinical trials as an experimental anticancer agent. We have shown previously (D. L. Kramer et al., J. Biol. Chem., 270: 2124-2132, 1995) that Chinese hamster ovary (CHO) cells that are made resistant to the growth inhibitory effects of the drug overexpress AdoMetDC because of a stable gene amplification. Unexpectedly, these same cells (CHO/644) were found to be insensitive to the growth inhibitory effects of N1,N11-diethylnorspermine (DENSPM) - a polyamine analogue also undergoing Phase 1 clinical trials - despite accumulating ~5 times more analogue than parental cells. We now report that treatment of CHO/664 cells with DENSPM results in the formation of numerous large cytoplasmic vacuoles, which on the basis of electron microscopy and cytochemical staining seem to be lysosomal in origin. A series of newly established CHO cell lines made differentially resistant to 1, 3, 10, 30, and 100 μM CGP-48664 by chronic exposure were used to demonstrate that vacuole formation correlated with the accumulation of extremely high levels of DENSPM without increasing growth inhibition. These same cells were used to show that AdoMetDC gene overexpression as indicated by mRNA levels was unrelated to vacuole formation; cells resistant to 100 μM CGP-48664 displayed a 170-fold increase in AdoMetDC mRNA levels and formed vacuoles in response to DENSPM, whereas those resistant to 10 μM CGP-48664 displayed a 120-fold increase in AdoMetDC mRNA levels and failed to form vacuoles. Despite accumulating to high intracellular levels, DENSPM was much less effective than spermine at down-regulating ornithine decarboxylase and polyamine transport activities in highly resistant cells. Similarly, DENSPM was less able to induce spermidine/spermine N1-acetyltransferase activity in cells that formed vacuoles than in those that did not. Overall, natural polyamines failed to induce vacuoles and various anaIogues of DENSPM were used to probe the structural specificity of the effect. The data are consistent with the probability that DENSPM is sequestered to high concentrations in lysosomal vacuoles of CGP-48664-resistant cells and is, therefore, not available to interact with polyamine regulatory sites or to cytotoxically affect cell growth. In addition to implicating the lysosome as a potential new site of CGP-48664 drug action that could be involved in antitumor activity and/or host toxicities, the findings also suggest a potential mechanism of cell resistance to analogues such as DENSPM.

AB - CGP-48664, an inhibitor of the polyamine biosynthetic enzyme S- adenosylmethionine decarboxylase (AdoMetDC), is presently undergoing Phase 1 clinical trials as an experimental anticancer agent. We have shown previously (D. L. Kramer et al., J. Biol. Chem., 270: 2124-2132, 1995) that Chinese hamster ovary (CHO) cells that are made resistant to the growth inhibitory effects of the drug overexpress AdoMetDC because of a stable gene amplification. Unexpectedly, these same cells (CHO/644) were found to be insensitive to the growth inhibitory effects of N1,N11-diethylnorspermine (DENSPM) - a polyamine analogue also undergoing Phase 1 clinical trials - despite accumulating ~5 times more analogue than parental cells. We now report that treatment of CHO/664 cells with DENSPM results in the formation of numerous large cytoplasmic vacuoles, which on the basis of electron microscopy and cytochemical staining seem to be lysosomal in origin. A series of newly established CHO cell lines made differentially resistant to 1, 3, 10, 30, and 100 μM CGP-48664 by chronic exposure were used to demonstrate that vacuole formation correlated with the accumulation of extremely high levels of DENSPM without increasing growth inhibition. These same cells were used to show that AdoMetDC gene overexpression as indicated by mRNA levels was unrelated to vacuole formation; cells resistant to 100 μM CGP-48664 displayed a 170-fold increase in AdoMetDC mRNA levels and formed vacuoles in response to DENSPM, whereas those resistant to 10 μM CGP-48664 displayed a 120-fold increase in AdoMetDC mRNA levels and failed to form vacuoles. Despite accumulating to high intracellular levels, DENSPM was much less effective than spermine at down-regulating ornithine decarboxylase and polyamine transport activities in highly resistant cells. Similarly, DENSPM was less able to induce spermidine/spermine N1-acetyltransferase activity in cells that formed vacuoles than in those that did not. Overall, natural polyamines failed to induce vacuoles and various anaIogues of DENSPM were used to probe the structural specificity of the effect. The data are consistent with the probability that DENSPM is sequestered to high concentrations in lysosomal vacuoles of CGP-48664-resistant cells and is, therefore, not available to interact with polyamine regulatory sites or to cytotoxically affect cell growth. In addition to implicating the lysosome as a potential new site of CGP-48664 drug action that could be involved in antitumor activity and/or host toxicities, the findings also suggest a potential mechanism of cell resistance to analogues such as DENSPM.

UR - http://www.scopus.com/inward/record.url?scp=0032170524&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=0032170524&partnerID=8YFLogxK

M3 - Article

C2 - 9731498

AN - SCOPUS:0032170524

VL - 58

SP - 3883

EP - 3890

JO - Cancer Research

JF - Cancer Research

SN - 0008-5472

IS - 17

ER -