Platelet-derived growth factor-B increases colon cancer cell growth in vivo by a paracrine effect

J Cell Physiol. 1995 Nov;165(2):239-45. doi: 10.1002/jcp.1041650204.

Abstract

PDGF-B released from colon tumor cells regulated tumor growth in athymic mice in a paracrine manner by inducing blood vessel formation. A positive correlation was found between expression of PDGF B-chain in cells grown in vitro and the number of factor VIII-positive blood vessels in tumors induced by three classes of colon carcinoma cell lines. Elevated expression of PDGF-B was also correlated with tumor size. Each cell line had the same mutations in the colon cancer genes APC, DCC, and p53 and had wild type c-K-ras genes (Huang et al. [1994] Oncogene, 9:3701-3706.) eliminating the possibility that any differences in tumor blood vessel formation were due to mutations and/or deletions in these genes. Colon carcinoma cells released biologically active PDGF capable of stimulating the growth of NIH3T3 cells, which was inhibited by neutralizing antisera to PDGF-AB chains. An inverse correlation was found between induction of factor VIII-positive blood vessels and expression of vascular endothelial growth factor (VEGF), while no correlation was seen with expression of either TGF alpha or k-FGF. Basic fibroblast growth factor (FGF) expression was not detected in these tumor cells. TGF beta 1 was capable of inducing PDGF-B expression in the undifferentiated U9 colon carcinoma cell line, but this sensitivity was not seen in differentiated cells. In contrast, TGF beta 1 inhibited VEGF expression in both undifferentiated cells and differentiated colon cancer cells. Thus, TGF beta 1 has two roles in the growth of undifferentiated U9 colon carcinoma cells in vivo: direct stimulation of cell proliferation as we have showed in earlier studies, and an increase in angiogenesis by inducing PDGF-B.

Publication types

  • Comparative Study
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Animals
  • Blood Vessels / pathology
  • Cell Division / drug effects
  • Colonic Neoplasms / blood supply
  • Colonic Neoplasms / metabolism
  • Colonic Neoplasms / pathology*
  • Endothelial Growth Factors / metabolism
  • Growth Substances / metabolism
  • Hormones / physiology
  • Humans
  • Lymphokines / metabolism
  • Male
  • Mice
  • Mice, Inbred BALB C
  • Platelet-Derived Growth Factor / metabolism
  • Platelet-Derived Growth Factor / pharmacology*
  • Proto-Oncogene Proteins / metabolism
  • Proto-Oncogene Proteins / pharmacology*
  • Proto-Oncogene Proteins c-sis
  • Transforming Growth Factor beta / pharmacology
  • Tumor Cells, Cultured
  • Vascular Endothelial Growth Factor A
  • Vascular Endothelial Growth Factors

Substances

  • Endothelial Growth Factors
  • Growth Substances
  • Hormones
  • Lymphokines
  • Platelet-Derived Growth Factor
  • Proto-Oncogene Proteins
  • Proto-Oncogene Proteins c-sis
  • Transforming Growth Factor beta
  • Vascular Endothelial Growth Factor A
  • Vascular Endothelial Growth Factors