Expression of IGF-II and IGF-binding proteins by colon cancer cells in relation to growth response to IGFs

Pomila Singh, B. Dai, C. Yallampalli, Z. Xu

Research output: Contribution to journalArticle

Abstract

We previously reported that even though virtually all human colon cancers were positive for IGF-I receptors, only 50% responded to growth effects of insulin-like growth factor (IGF)-I (1-100 nM). The present studies were undertaken to determine whether expression and secretion of IGFs (IGF-I, IGF- II) and IGF-binding proteins (BPs; 1-6) were perhaps different in IGF- responsive (COLO 205, COLO 320, Caco-2) and IGF-nonresponsive (HCT 116, HT- 29, DLD-1) cells. Several bands (2.0-6.0 kb) of IGF-II mRNA transcripts were detected in all the cell lines; none expressed IGF-I. Significant concentrations of IGF-II (0.2-0.9 ng/10b cells) were measured in the conditioned media (CM) of the cells. All cell lines expressed BP2 and/or BP4 mRNA and secreted BP4 (24 kDa) and/or BP2 (32.5 kDa); BP1 was not detected in any cell line. Interestingly, BP3 mRNA was measured only in the responsive cell lines. The relative concentration of total BPs tended to be higher in the CM of nonresponsive cells. Interestingly, a large concentration of 44- to 48-kDa BP (BP3?) was associated with the membranes of only the responsive cell lines. Our present studies thus demonstrate that human colon cancers do not secrete IGF-I and BP1. Of all the IGF-related factors examined, the quantity and the type of BPs expressed by the human colon cancer cell lines (especially BP2, BP4, and BP3) may significantly dictate the growth response of the cells to exogenous IGF-I.

Original languageEnglish (US)
JournalAmerican Journal of Physiology - Gastrointestinal and Liver Physiology
Volume267
Issue number4 30-4
StatePublished - 1994

Fingerprint

Insulin-Like Growth Factor Binding Proteins
Insulin-Like Growth Factor II
Colonic Neoplasms
Insulin-Like Growth Factor I
Cell Line
Somatomedins
Growth
Conditioned Culture Medium
Messenger RNA
Insulin-Like Growth Factor Binding Protein 1
IGF Type 1 Receptor
Membranes

Keywords

  • growth factors
  • insulin-like growth factor II
  • insulin-like growth factor- binding protein 3
  • insulin-like growth factor-binding protein 4

ASJC Scopus subject areas

  • Physiology
  • Gastroenterology

Cite this

@article{7aa38037d33a46a8bd40bee0ada52561,
title = "Expression of IGF-II and IGF-binding proteins by colon cancer cells in relation to growth response to IGFs",
abstract = "We previously reported that even though virtually all human colon cancers were positive for IGF-I receptors, only 50{\%} responded to growth effects of insulin-like growth factor (IGF)-I (1-100 nM). The present studies were undertaken to determine whether expression and secretion of IGFs (IGF-I, IGF- II) and IGF-binding proteins (BPs; 1-6) were perhaps different in IGF- responsive (COLO 205, COLO 320, Caco-2) and IGF-nonresponsive (HCT 116, HT- 29, DLD-1) cells. Several bands (2.0-6.0 kb) of IGF-II mRNA transcripts were detected in all the cell lines; none expressed IGF-I. Significant concentrations of IGF-II (0.2-0.9 ng/10b cells) were measured in the conditioned media (CM) of the cells. All cell lines expressed BP2 and/or BP4 mRNA and secreted BP4 (24 kDa) and/or BP2 (32.5 kDa); BP1 was not detected in any cell line. Interestingly, BP3 mRNA was measured only in the responsive cell lines. The relative concentration of total BPs tended to be higher in the CM of nonresponsive cells. Interestingly, a large concentration of 44- to 48-kDa BP (BP3?) was associated with the membranes of only the responsive cell lines. Our present studies thus demonstrate that human colon cancers do not secrete IGF-I and BP1. Of all the IGF-related factors examined, the quantity and the type of BPs expressed by the human colon cancer cell lines (especially BP2, BP4, and BP3) may significantly dictate the growth response of the cells to exogenous IGF-I.",
keywords = "growth factors, insulin-like growth factor II, insulin-like growth factor- binding protein 3, insulin-like growth factor-binding protein 4",
author = "Pomila Singh and B. Dai and C. Yallampalli and Z. Xu",
year = "1994",
language = "English (US)",
volume = "267",
journal = "American Journal of Physiology - Endocrinology and Metabolism",
issn = "0193-1849",
publisher = "American Physiological Society",
number = "4 30-4",

}

TY - JOUR

T1 - Expression of IGF-II and IGF-binding proteins by colon cancer cells in relation to growth response to IGFs

AU - Singh, Pomila

AU - Dai, B.

AU - Yallampalli, C.

AU - Xu, Z.

PY - 1994

Y1 - 1994

N2 - We previously reported that even though virtually all human colon cancers were positive for IGF-I receptors, only 50% responded to growth effects of insulin-like growth factor (IGF)-I (1-100 nM). The present studies were undertaken to determine whether expression and secretion of IGFs (IGF-I, IGF- II) and IGF-binding proteins (BPs; 1-6) were perhaps different in IGF- responsive (COLO 205, COLO 320, Caco-2) and IGF-nonresponsive (HCT 116, HT- 29, DLD-1) cells. Several bands (2.0-6.0 kb) of IGF-II mRNA transcripts were detected in all the cell lines; none expressed IGF-I. Significant concentrations of IGF-II (0.2-0.9 ng/10b cells) were measured in the conditioned media (CM) of the cells. All cell lines expressed BP2 and/or BP4 mRNA and secreted BP4 (24 kDa) and/or BP2 (32.5 kDa); BP1 was not detected in any cell line. Interestingly, BP3 mRNA was measured only in the responsive cell lines. The relative concentration of total BPs tended to be higher in the CM of nonresponsive cells. Interestingly, a large concentration of 44- to 48-kDa BP (BP3?) was associated with the membranes of only the responsive cell lines. Our present studies thus demonstrate that human colon cancers do not secrete IGF-I and BP1. Of all the IGF-related factors examined, the quantity and the type of BPs expressed by the human colon cancer cell lines (especially BP2, BP4, and BP3) may significantly dictate the growth response of the cells to exogenous IGF-I.

AB - We previously reported that even though virtually all human colon cancers were positive for IGF-I receptors, only 50% responded to growth effects of insulin-like growth factor (IGF)-I (1-100 nM). The present studies were undertaken to determine whether expression and secretion of IGFs (IGF-I, IGF- II) and IGF-binding proteins (BPs; 1-6) were perhaps different in IGF- responsive (COLO 205, COLO 320, Caco-2) and IGF-nonresponsive (HCT 116, HT- 29, DLD-1) cells. Several bands (2.0-6.0 kb) of IGF-II mRNA transcripts were detected in all the cell lines; none expressed IGF-I. Significant concentrations of IGF-II (0.2-0.9 ng/10b cells) were measured in the conditioned media (CM) of the cells. All cell lines expressed BP2 and/or BP4 mRNA and secreted BP4 (24 kDa) and/or BP2 (32.5 kDa); BP1 was not detected in any cell line. Interestingly, BP3 mRNA was measured only in the responsive cell lines. The relative concentration of total BPs tended to be higher in the CM of nonresponsive cells. Interestingly, a large concentration of 44- to 48-kDa BP (BP3?) was associated with the membranes of only the responsive cell lines. Our present studies thus demonstrate that human colon cancers do not secrete IGF-I and BP1. Of all the IGF-related factors examined, the quantity and the type of BPs expressed by the human colon cancer cell lines (especially BP2, BP4, and BP3) may significantly dictate the growth response of the cells to exogenous IGF-I.

KW - growth factors

KW - insulin-like growth factor II

KW - insulin-like growth factor- binding protein 3

KW - insulin-like growth factor-binding protein 4

UR - http://www.scopus.com/inward/record.url?scp=0027999753&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=0027999753&partnerID=8YFLogxK

M3 - Article

C2 - 7524348

VL - 267

JO - American Journal of Physiology - Endocrinology and Metabolism

JF - American Journal of Physiology - Endocrinology and Metabolism

SN - 0193-1849

IS - 4 30-4

ER -