Different responses to EGF in two human carcinoma cell lines, A431 and UCVA-1, possessing high numbers of EGF receptors

Mol Cell Endocrinol. 1984 Sep;37(2):205-13. doi: 10.1016/0303-7207(84)90053-4.

Abstract

EGF binding capacity was examined in 9 different human cell lines which were derived from colon, rectum and pancreas tumors. Among these cell lines, a pancreatic carcinoma cell line, UCVA-1, was found to possess a high number (0.9 X 10(6)/cell) of EGF receptors. This number is comparable to that of EGF receptors in human vulva epidermoid carcinoma A431 cells (2 X 10(6)/cell). However, it was found that, unlike A431 cells, the growth of UCVA-1 cells, in serum-containing and serum-free conditions, was not inhibited by EGF. The UCVA-1 cells have EGF receptor of Mr = 170 K and of two affinity types: Kd1 = 72 X 10(-9) M and Kd2 = 2 X 10(-8) M. The EGF receptors in UCVA-1 cells are less susceptible to proteolytic cleavage than those in A431 cells. In UCVA-1 cells, EGF is apparently processed via a receptor-mediated endocytosis. The UCVA-1 cell membrane contained EGF-stimulated protein kinase as was found in A431 cells. The stimulation of phosphorylation by EGF was only approximately 20% in UCVA-1 while it was over 100% in A431. When angiotensin II was used as a substrate, the relative activity of EGF-dependent tyrosine-specific protein phosphorylation was approximately 8 times less in UCVA-1 cell membrane. The EGF-stimulated phosphorylation was mostly on EGF receptors for both cell lines. However, several other components (Mr = 100 K, 80 K, 72 K and 65 K) were readily detected in A431 cells. These observations indicate that the EGF receptor/protein kinase relation differs in these two cell lines and suggests that it may be related to the growth-inhibitory effect of EGF seen in A431.

Publication types

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

MeSH terms

  • Carcinoma, Squamous Cell / analysis*
  • Carcinoma, Squamous Cell / pathology
  • Cell Line
  • Epidermal Growth Factor / metabolism
  • Epidermal Growth Factor / pharmacology*
  • ErbB Receptors
  • Female
  • Humans
  • Kinetics
  • Pancreatic Neoplasms / analysis*
  • Pancreatic Neoplasms / pathology
  • Phosphoproteins / analysis
  • Phosphorylation
  • Protein Kinases / analysis
  • Receptors, Cell Surface / analysis*
  • Vulvar Neoplasms / analysis*
  • Vulvar Neoplasms / pathology

Substances

  • Phosphoproteins
  • Receptors, Cell Surface
  • Epidermal Growth Factor
  • Protein Kinases
  • ErbB Receptors